JP5636748B2 - Sliding member, apparatus provided with sliding member, and surface treatment method of sliding member - Google Patents

Description

  The present invention relates to a sliding member and a surface treatment method thereof, and more particularly to a member suitable for a sliding surface of a sliding member mainly made of a metal material for an apparatus in a compressor for a refrigeration cycle or the like.

  Reducing the friction loss of the sliding member is necessary for improving the efficiency and reliability of the apparatus. For example, in the case of a reciprocating compressor used in a refrigerator or the like, the thickness of the oil film existing between the sliding members is set to about 1 to 2 μm or less at a generally used rotational speed of 1500 rpm to 3000 rpm. Yes.

  Conventionally, in order to reduce friction loss, efforts have been made to smooth as much as possible to remove fine irregularities on the sliding surface that comes into contact, but in order to reduce friction loss, smoothed sliding has been made. There is a technique for performing a process for forming a recess in a sliding surface of a member.

  Specifically, as shown in FIG. 32, a technique for forming innumerable concave portions 36 having a substantially arc-shaped cross section on a sliding surface 37 of a sliding member 32 is disclosed (for example, see Patent Document 1).

  31 and 32 show a state in which the sliding members 30 and 32 that slide with each other face each other.

  These sliding members 30 and 32 are opposed to each other through an oil film of lubricating oil (not shown), and FIG. 31 shows both the sliding member 32 and each sliding surface 34 of the sliding member 30 facing this. It shows a smoothed appearance. FIG. 32 shows a state in which the sliding surface of one of the opposing sliding members 30 is smoothed and an infinite number of recesses 36 are provided on the sliding surface 37 of the other sliding member 32.

  According to Patent Document 1, when lubricating oil is supplied to the sliding surface 37, the lubricating oil becomes oil balls in the indented recesses 36 formed by surface tension, and when a load is applied, the oil adjacent to each indenting 36. The balls are connected to each other, and an oil film is formed over the entire sliding surface.

Japanese Unexamined Patent Publication No. 07-188738

  However, in the conventional compressor for refrigeration cycle, etc., in order to further increase the output, reduce the rotation for preventing noise and vibration, or improve the efficiency, the viscosity of the lubricating oil or the sliding portion is reduced. As the efficiency is improved by the reduction, it is assumed that the sliding state of the sliding member will become more severe in the future.

  That is, when the sliding surfaces between the sliding members 30 and 32 shown in FIG. 31 are smooth with each other, the contact sliding surface 34 cannot sufficiently hold the lubricating oil, and the oil film is broken and the sliding member is broken. 30 and 32 may contact each other. If such a sliding state in the boundary lubrication region continues between the sliding members 30 and 32 for a long time, adhesion and abrasive wear may progress, eventually resulting in seizure lock and abnormal wear. .

Further, as in Patent Document 1 shown in FIG. 32, when innumerable recesses 36 are provided on the sliding surface 37,
After a while from the start of sliding, the friction coefficient may suddenly increase, or the friction coefficient may change to a high value with a large fluctuation immediately after the start of sliding. There may be severe wear on the sliding surface.

  Under such circumstances, the present invention was made in order to solve the above-described conventional problems. Instead of simply providing innumerable recesses on the surface of the sliding member, according to sliding (operating) conditions, By appropriately setting the ratio of the opening of the recess formed in the entire sliding surface or in a certain region (hereinafter referred to as the opening area ratio), the portion where the recess does not exist on the sliding surface (hereinafter referred to as flat) When the load is applied, the load is received by the flat part on the sliding surface and the lubricating oil held in the concave part is applied to the flat part. An object of the present invention is to provide a highly reliable sliding member and a surface treatment method thereof that can reduce friction loss and wear even under severer sliding conditions due to oozing.

  The sliding member of the present invention does not simply provide innumerable recesses on the sliding surface of the sliding member, but by appropriately setting the opening area ratio of the recesses in the entire sliding surface or in a certain region. By mixing the concave portion and the flat portion at a predetermined ratio on the surface, it is possible to effectively exude the lubricating oil from the surface pressure relaxation at the time of contact and the oil reservoir, and to reduce friction loss and wear.

  Further, in the surface treatment method for a sliding member of the present invention, in order to provide a concave portion on the sliding surface of the sliding member, by projecting projection particles having a substantially spherical shape and an average particle size of 3 to 200 μm, By a simple method, a concave portion having an opening having a substantially circular shape and a sectional shape having a substantially arc shape can be provided on the sliding surface of the sliding member in a substantially uniform manner.

According to the sliding member of the present invention, at least one of the two sliding members arranged so that one slides with respect to the other, the entire sliding surface of the sliding member, or the constant sliding surface. A ratio of the total area of the opening portion of the concave portion occupying the entire area of the sliding surface or a certain region in which the dimple-shaped concave portion and the flat portion provided between the concave portions are mixedly provided in the region. The sliding surface pressure is distributed by receiving a load at the flat part by interposing a lubricant or lubricating oil between the two sliding members and making the opening area ratio in the range of 5 to 20 %. In addition, the lubricant or the lubricating oil held in the concave portion oozes out into the flat portion, thereby reducing adhesion wear, so that when a load is applied, At the flat part, the load is received by the surface and in the concave part. Since the retained lubricating oil oozes out to the flat portion, the effect of reducing friction loss and wear and providing a highly reliable sliding member even under more severe sliding conditions can be obtained.

  Moreover, the apparatus provided with the sliding member of this invention can suppress the loss accompanying sliding, and can achieve the lifetime of a sliding part.

  Furthermore, according to the surface treatment method for a sliding member of the present invention, a substantially circular recess can be provided efficiently and uniformly on the sliding surface of the sliding member. By providing the surface without overlapping the concave portion, it is possible to provide a surface treatment method capable of reducing friction loss and wear and obtaining high reliability.

The perspective schematic diagram of the sliding surface of the sliding member in Embodiment 1 of this invention Sectional schematic diagram of the sliding surface of the sliding member in the first embodiment Schematic diagram of the manufacturing method of the sliding member in the first embodiment The perspective view of the friction experiment apparatus for evaluating the friction characteristic of the sliding member in Embodiment 1 The characteristic view which shows the relationship between the coefficient of friction and the friction distance which made the parameter the form of the sliding surface of the sliding member in Embodiment 1 The characteristic view which shows the relationship between the coefficient of friction and the friction distance which made the form of the sliding surface the parameter at the time of changing the conditions of the sliding member in Embodiment 1 as a parameter The figure which shows the microscope picture of the sliding face which is an example of the sliding member in the same Embodiment 1. Condition range diagram of opening area ratio and surface roughness in which improvement of friction and wear characteristics of sliding member in Embodiment 1 is confirmed Schematic diagram for explaining the comparison between the sliding state of the first embodiment and the conventional configuration in the present invention Schematic of the ridge formed on the sliding member obtained by the manufacturing method in the first embodiment The longitudinal cross-sectional view of the reciprocating type compressor which can use the sliding member of Embodiment 1 Vertical sectional view of a rotary type compressor capable of using the sliding member of the first embodiment Vertical sectional view of a scroll type compressor that can use the sliding member of the first embodiment Top view schematic diagram of sliding surface of sliding member in Embodiment 2 of the present invention Sectional schematic diagram of the sliding surface of the sliding member in Embodiment 2 The schematic diagram of the equipment used for the manufacturing method of the sliding member in Embodiment 2 Sectional drawing of the metal mold | die used for manufacture of the sliding member in Embodiment 2 The perspective view of the friction experiment apparatus for evaluating the friction characteristic of the sliding member in Embodiment 2 The characteristic view which shows the relationship between the friction coefficient and the sliding distance which made the parameter the form of the sliding surface of the sliding member in Embodiment 2 Characteristic correlation diagram of the number of bearing characteristics and the coefficient of friction with different forms of sliding surfaces of the sliding member in the second embodiment as parameters Characteristic correlation diagram between the number of bearing characteristics and the friction coefficient in consideration of the opening area ratio of the sliding member in the second embodiment The characteristic view which shows the relationship between the coefficient of friction and the sliding distance which used the form of the sliding surface as a parameter when the conditions of the sliding member in Embodiment 2 were changed The characteristic correlation diagram of the number of bearing characteristics and the coefficient of friction with the different form of the sliding surface of the sliding member in the second embodiment as a parameter Characteristic correlation diagram of the number of bearing characteristics and the friction coefficient in consideration of the opening area ratio of the sliding member having different sliding surfaces in the second embodiment Top view schematic diagram of sliding surface of sliding member in Embodiment 3 of the present invention Cross-sectional schematic diagram of the sliding surface of the sliding member in the third embodiment The schematic diagram of the equipment used for the manufacturing method in the sliding member of Embodiment 3 Sectional drawing of the metal mold | die used for manufacture of the sliding member in the same Embodiment 3 The characteristic figure which shows the relationship between the friction coefficient which made the parameter the form of the sliding surface of the sliding member in Embodiment 3, and the sliding distance Characteristic correlation diagram of the number of bearing characteristics and the coefficient of friction with the form of the sliding surface of the sliding member in the third embodiment as a parameter Cross-sectional schematic diagram of sliding surface of sliding member in conventional form Cross-sectional schematic diagram of different sliding surfaces of the sliding member in the conventional form

According to the first aspect of the present invention, the entire sliding surface of at least one of the two sliding members arranged so that one slides with respect to the other, or a certain region of the sliding surface. In addition, a dimple-shaped recess and a flat portion provided between the recesses are provided in a mixed manner, and the entire area of the sliding surface or a ratio of the total area of the opening of the recess in a certain region A certain opening area ratio is set in a range of 5 to 20 %, and a lubricant or lubricating oil is interposed between the two sliding members, and a load is applied to the flat portion to disperse the sliding surface pressure. At the same time, the adhesive or wear is alleviated by the lubricant or the lubricating oil held in the recess oozing out into the flat portion .

  By adopting such a configuration, when a load is applied to the sliding surface, the load is received by the flat portion on the sliding surface, and the lubricating oil is held in the recess by receiving the surface pressure. As a result of oozing out into the flat portion, generation of an oil film on the sliding surface is promoted. As a result, even under more severe sliding conditions, it is possible to reduce friction loss and wear and provide a highly reliable sliding member.

  According to a second aspect of the present invention, in the first aspect of the present invention, the opening of the recess has a substantially circular shape when viewed from the front and has a substantially arcuate cross section.

  By adopting such a configuration, even if the oil retaining action in the concave portion is good and the supply of the lubricating oil from the outside is delayed, the lubricating oil held in the concave portion is flattened to receive a load. Can exude effectively. As a result, it is possible to provide a highly reliable sliding member with a stable effect of reducing friction loss and wear on the sliding surface.

The invention according to claim 3 is the invention according to claim 1 or 2, wherein the surface roughness Ra of the sliding surface of the sliding member is 0.3 or less.

  As a result, adhesion due to the surface tension of the lubricating oil is ensured, and the oil film is sheared by the rough surface, and the lubricating oil held in the recess through the rough surface is prevented from flowing out of the sliding surface. can do. As a result, the effect of reducing friction loss and wear on the sliding surface can be further stabilized and reliability can be ensured.

  The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the depth of the recess is in the range of 0.5 to 3.0 μm.

  As a result, it is possible to favorably maintain the degree of oozing of the lubricating oil to the sliding surface due to the depth of the recess, and promote the formation of an oil film. That is, when the depth of the concave portion exceeds 3.0 μm, it is difficult for the concave portion to exude to the flat portion that receives the load of the lubricating oil held in the concave portion, and the depth of the concave portion is 0.5 μm or less. In this case, as the retention of the lubricating oil decreases, the substantial difference from the oil retaining action on a smooth surface becomes smaller. Therefore, a stable lubricating action can be obtained by setting the depth of the recess to an appropriate range.

  According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, the two sliding members are made of materials having different hardnesses and are formed of a material having low hardness. The concave portion is provided on the surface of the member.

  As a result, even if a submicron-order bulge is generated around the concave part in the course of the concave part forming process, the bulge is worn away and removed immediately after the start of sliding because the material is low in hardness. can do. As a result, damage to the sliding surface can be avoided and the reliability of the sliding member can be improved.

  A sixth aspect of the present invention is the slide according to any one of the first to fourth aspects, wherein the two sliding members are made of materials having different hardnesses and are made of the high hardness material. The concave portion is provided on the surface of the member.

  As a result, the progress of wear is remarkably suppressed as compared with the case where the concave portion is provided in the sliding member having low hardness, and the effect of the concave portion as an oil reservoir can be maintained for a long time. As a result, reliability can be maintained.

The invention according to claim 7 is the invention according to any one of claims 1 to 6, wherein an area smaller than the recess is provided between the recesses formed on the sliding surface of the sliding member. A minute recess is provided.

  With such a configuration, the sliding area on the sliding surface can be further reduced, and the concave and minute concave portions are used as a lubricant or a holding portion for lubricating oil so that a sliding sound accompanying the sliding can be generated. It can suppress and can further improve wear resistance.

  The invention according to claim 8 is the invention according to claim 7, wherein the depth of the minute recess is formed shallower than the depth of the recess.

  By adopting such a configuration, it is possible to suppress a decrease in the surface strength of the sliding member, and the lubrication retained in the minute recesses and the recesses even under a condition where the supply of lubricating oil from the outside is small. Oil can be effectively oozed out to the flat portion of the sliding surface that receives the load, and the reliability for reducing friction loss and wear can be improved by ensuring the formation of the oil film.

  The invention according to claim 9 is the invention according to claim 7, wherein the depth of the minute recess is formed deeper than the depth of the recess.

  By adopting such a configuration, under conditions where an appropriate amount of lubricant or lubricating oil is appropriately supplied, the holding amount of the lubricant or lubricating oil is increased, a sliding structure with a high load, or a sliding with a high friction speed. Friction loss can be effectively reduced in response to severe friction conditions such as dynamic structures.

  A tenth aspect of the present invention is the invention according to any one of the seventh to tenth aspects, wherein the minute recess is a minute groove.

  As a result, the lubricant or lubricating oil supplied between the sliding members can function as a supply oil path to the flat portion of the sliding surface of the sliding member and the concave portion. Even in the case of sliding conditions, a lubricant or lubricating oil can be held between the sliding members, and sliding loss and wear can be reduced.

  The invention according to claim 11 is the invention according to claim 10, wherein the extending direction of at least some of the fine grooves in the fine grooves is parallel to the sliding direction of the sliding member.

  As a result, a contact area with the lubricant or the lubricating oil can be secured in the sliding direction of the sliding member, and particularly in the case of a sliding configuration with a long sliding distance, the sliding of the sliding member. The fine groove can efficiently function as a lubricant and lubricating oil supply to the flat portion and the concave portion of the surface. As a result, even in the case of more severe sliding conditions, the lubricity between the sliding members can be maintained, friction loss and wear can be reduced, and a highly reliable sliding member can be provided.

  According to a twelfth aspect of the present invention, in the invention according to the tenth or eleventh aspect, the extending direction of at least a part of the fine grooves in the fine grooves is a predetermined angle with respect to the sliding direction of the sliding member. It is intended to intersect.

  As a result, a contact area with the lubricant or lubricating oil can be ensured in the lateral direction with respect to the sliding direction of the sliding member, and particularly in the case of a sliding configuration with a short sliding distance, the sliding member The fine groove can be efficiently functioned as a lubricant and lubricating oil supply to the flat portion and concave portion of the sliding surface. As a result, even in the case of more severe sliding conditions, the lubricity between the sliding members can be maintained, friction loss and wear can be reduced, and a highly reliable sliding member can be provided.

  According to a thirteenth aspect of the present invention, in a device having a configuration in which a plurality of parts are in a sliding relationship, the components that form the sliding relationship are defined in any one of the first to twelfth aspects. The device is a sliding member.

  As a result, friction loss and wear can be reduced, and a device having a highly reliable sliding component over a long period of time can be provided.

  In the invention described in claim 14, the device is a compressor.

  Accordingly, it is possible to provide a compressor having a sliding component with high reliability over a long period of time.

  The invention according to a fifteenth aspect is according to any one of the first to ninth aspects, wherein projecting particles having a substantially spherical shape and an average radius of 3 to 200 μm are projected onto the surface of the sliding member. The surface treatment method of the sliding member for forming the dimple-like concave portion is provided.

  As a result, a substantially circular concave portion can be provided efficiently and uniformly on the sliding surface of the sliding member, and the sliding amount can be controlled by controlling the amount of projection particles and the projection conditions. The concave portion can be provided without overlapping the sliding surface of the member.

  The invention according to claim 16 is characterized in that a die having a substantially arc-shaped convex portion provided on one surface so as to be regularly or irregularly arranged, the entire sliding surface of the sliding member, or It is set as the surface treatment method of the sliding member which forms the dimple-shaped recessed part as described in any one of Claim 1 to 12 by pressing on arbitrary area | regions.

  Thus, a substantially circular concave portion can be efficiently provided on the sliding surface of the sliding member, and the arrangement of the convex portion, the pressing load of the mold, the mold or the sliding member By controlling the feed rate, etc., the concave portion can be provided on the sliding surface of the sliding member.

  The invention described in claim 17 is the slide according to the invention described in claim 16, wherein the ridges on the peripheral surface of the recesses are formed as sliding surfaces along with the formation of the recesses, and the ridges are formed as fine grooves. This is a surface treatment method for a member.

  Accordingly, the fine groove can be formed in one step by pressing the concave portion and the fine concave portion, and a rational and mass-productive surface treatment method can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a schematic perspective view of a sliding surface of a sliding member according to Embodiment 1 of the present invention. FIG. 2 is a schematic cross-sectional view of the sliding surface of the sliding member in the first embodiment. FIG. 3 shows a schematic diagram of the manufacturing method of the sliding member in the first embodiment.

1 and 2, the sliding member 132 relates to at least one sliding member 132 of the two sliding members 130 and 132 arranged so that one slides with respect to the other. A large number of dimple-shaped recesses 136 are formed on the sliding surface 138 of the member 132. Therefore, a flat portion 137 is formed between each dimple-shaped recess 136. The recess 136 is formed by projecting substantially spherical projection particles 124 onto the sliding surface 138 of the sliding member 132 by a shot peening apparatus 121 as shown in FIG.

  In the shot peening apparatus 121, as shown in FIG. 3, a projected particle feed pipe 122 for transferring the projected particles 124 stored in a storage tank (not shown) is joined to a gas pipe 111 through which a carrier gas 123 flows. The nozzle 125 is installed at the tip of the gas pipe 111. A mesh-like wire mesh 127 is disposed between the nozzle 125 and the sliding surface 138.

  As the projecting particles 124, glass beads, iron powder, ceramic spheres, or the like are known. In the first embodiment, substantially spherical glass beads having an average particle diameter of about 50 μm are used. The projecting particles 124 stored in the storage tank are transferred to a joint portion with the gas pipe 111 through the projecting particle feed pipe 122 by an electric gear pump (not shown).

  The carrier gas 123 in the gas pipe 111 is dry air using an air pump (not shown). The projecting particles 124 continuously transferred to the joint portion between the gas pipe 111 and the projecting particle feed pipe 122 are projected substantially perpendicularly to the sliding surface of the sliding member 132 from the tip end of the nozzle 125 by the carrier gas 123. Is done.

  Here, the pressure at the time of projection is selected to be constant within a range of 0.5 MPa or less. Furthermore, by installing a mesh-shaped wire net 127 between the nozzle 125 and the sliding surface 138 of the sliding member 132 to block a certain amount of the projected particles 124 projected from the nozzle 125, the sliding surface 138 The amount and size of the projecting particles 124 that collide are suppressed.

  By changing the installation location of the wire mesh 127 and the mesh size of the wire mesh 127, the projection amount of the projection particles 124 is controlled, and the shape factor (depth, opening diameter, etc.) of the recess 136 formed on the sliding surface 138, the opening area ratio, The surface roughness of the sliding surface 138 is adjusted.

  Here, the opening area ratio means the ratio of the total area of the opening portion (non-contact portion) of the recess 136 to the area of the sliding surface 138. Therefore, in the following description, the sliding surface 138 will be described not as a surface of only the portion that contacts the sliding member 130 but as a region that includes the recess 136 and is in contact with the sliding member 130.

  Further, by using the substantially spherical projection particles 124, the surface shape of the recess 136 becomes spherical, and the opening of the recess 136 becomes substantially circular when the sliding surface 138 is viewed from above, and is perpendicular to the sliding surface 138. The cross-sectional shape cut by the surface is substantially arcuate.

  The friction characteristics of the sliding member 132 having the recess 136 formed by the manufacturing process as described above were evaluated by a ring-on-disk type experimental apparatus. FIG. 4 is a perspective view of the friction test apparatus.

  In this friction test apparatus, a ring-shaped sliding member 12 and a disk-shaped sliding member 10 are mounted as two sliding members, and the ring-shaped sliding member 12 is transmitted via a drive member 14 and a pin 16. While rotating in a predetermined direction by a rotational force, it is configured to receive a load load from above via a stationary shaft 18.

Therefore, the ring-shaped sliding member 12 rotates on the sliding surface 138 of the disk-shaped sliding member 10 while contacting the disk-shaped sliding member 10 with a predetermined pressure. Friction occurs between the moving members 10. Note that lubricating oil (oil film) (not shown) exists between the two sliding members 10 and 12. Further, the guide portion 20 serves as a stationary shaft bearing, and the ball bearing 22 includes a ring-shaped sliding member 12 and a disk-shaped sliding member 10.
The centering mechanism is responsible for the contact with the surface without contact.

  In addition, the experimental conditions by the said friction experiment apparatus are as (Table 1).

  The ring-shaped sliding member 12 (corresponding to the sliding member 130) has an outer diameter of 40 mm, an inner diameter of 30 mm, a material made of high chromium steel (SCM415, hardness HV240 or so) and a surface roughness of Ra 0.1 or less. As one disk-like sliding member 10 (corresponding to the sliding member 132), the outer diameter is 56 mm, the material is an aluminum alloy (A6063, hardness is about HV60), and the surface roughness is about Ra0.1. The one that has been lapped is used.

Assuming a sliding state in which an oil film is hardly formed and metal contact occurs, the operating conditions are a vertical load of 45 N, a sliding speed of 0.1 m / s, and a viscosity of about 30 mm ² / s at 20 ° C. Only 20 μL of oil is dropped on the contact sliding part before the experiment, and no oil is supplied during the experiment, and the lubricating oil is consumed as the friction time (slip distance) increases.

  First, a test piece in which the sliding surface 138 of the disk-shaped sliding member 10 formed of a relatively low hardness material (aluminum alloy) is lapped and then subjected to the projection treatment of the projecting particles 124 on the sliding surface 138. Friction experiments were conducted using

  Next, the result of the friction experiment will be described with reference to FIG.

  In order to evaluate the friction and wear characteristics of the first embodiment, various parameters using the opening area ratio and surface roughness of the recess 136 of the sliding surface 138 of the disk-shaped sliding member 10 and the depth of the recess 136 as parameters. The specifications of the conditions are shown in (Table 2). The other ring-shaped sliding member 12 is a smooth surface of Ra0.1 only by lapping.

  Here, the opening area ratio means the ratio of the total area of the opening portions of the recesses 136 to the area of the sliding surface 138 where the ring-shaped sliding member 12 and the disk-shaped sliding member 10 come into contact.

That is, after taking a part of the sliding surface 138 of the sliding member with a laser microscope and performing computer image processing, and separating the opening of the recess 138 and the flat portion 137 where the projected particles do not collide, By dividing the sum of the opening areas of the openings of the individual recesses 138 by the total area of the sliding surface 138 used for image processing, the opening area ratio is obtained. In addition, the average value of the opening area ratio obtained by changing the measurement location several times was used as the representative value under the conditions.

  Further, the surface roughness indicates an average value obtained by measuring several times with a stylus type shape measuring machine, and the depth of the concave portion 138 indicates an average value obtained by measuring several times with a laser microscope.

  FIGS. 5A and 5B are characteristic diagrams showing the relationship between the friction coefficient and the friction distance with the form of the sliding surface 138 in the first embodiment as parameters. In both cases, the friction distance is shown on the x-axis and the friction coefficient is shown on the y-axis.

  FIG. 5A shows the results of Example 1, Condition 1, Example 1, Condition 2, and conventional Comparative Example 1, Condition 3, which are the first embodiment. In the condition 1 of Example 1, the opening area ratio of the recess 136 is 30%, the surface roughness of the sliding surface 138 is Ra 0.35, and the depth of the recess 136 is 1.9 μm.

  In Example 1 Condition 1, the opening area ratio of the recess 136 is 50%, the surface roughness of the sliding surface 138 is Ra 0.35, and the depth of the recess 136 is 2.1 μm. Comparative Example 1 Condition 3 does not perform projection processing and is a conventional smooth surface 138, and the surface roughness of the sliding surface 138 is Ra 0.1.

  From FIG. 5 (a), in the case of Comparative Example 1 Condition 3 in which both the conventional ring-shaped sliding member and the disk-shaped sliding member are smooth surfaces, the friction coefficient is 0.1 or more and is accompanied by large fluctuations. It can be seen that the sliding state is such that it is not strange when seizure occurs. When the sliding surface 138 after the completion of the experiment was confirmed, scratches and severe wear due to sliding occurred.

  On the other hand, in the case of Example 1 Condition 1 in which the opening area ratio of the first embodiment is 50%, the friction coefficient has a portion that shows a value of about 0.1 when the sliding distance is less than 200 m. Is 200 m or more, the friction coefficient is smaller than 0.1, and the fluctuation range is significantly smaller than the condition 3 in the conventional comparative example 1 over the entire sliding distance.

  Further, in the case of Example 1 Condition 2 where the area ratio is 30%, the friction coefficient changes from decreasing to increasing slightly in the vicinity of the sliding distance of 400 m. It can be seen that it is small over the sliding distance. As a result of confirming the sliding surface 138 after the end of the experiment, the scratches and wear due to sliding were minor compared to the conventional Comparative Example 1 Condition 3, and the Condition 1 of Example 1 was better.

  Therefore, when the concave portion 136 is provided on the material side having a relatively low hardness from this figure, the friction coefficient is reduced and the fluctuation range is reduced as compared with the case where the concave portion 136 is not provided on the sliding surface 138.

  On the other hand, in FIG. 5B, an infinite number of projecting particles 124 are projected as in the prior art, the opening area ratio of the recess 136 of the sliding surface 138 is 70%, and the surface roughness of the sliding surface 138 is Ra0. 51, comparative example 1 condition 2 finished in a so-called satin finish with the depth of the recess 136 being 3.6 μm, the opening area ratio is 55%, the surface roughness of the sliding surface 138 is Ra 0.43, and the recess 136 The result of Comparative Example 1 Condition 3 with a depth of 3.0 μm is shown.

  In the case of the comparative example 1 condition 2, the friction coefficient is maintained at 0.1 or more and the fluctuation range is large, and there is no significant difference from the smoothing surface comparative example 1 condition 1 shown in FIG. When the sliding surface 138 after the experiment was confirmed, almost all of the recess 136 disappeared or was filled with wear powder, and scratches and wear due to sliding occurred.

  Moreover, in the case of the comparative example 1 condition 3, the friction coefficient changes 0.1 or more and its behavior is unstable. Similarly, when the sliding surface 138 after the experiment was confirmed, scratches and wear due to sliding occurred.

  From the above experimental results, by setting the opening area ratio to 50% or less, both of them have a low friction coefficient and their fluctuations compared to the case where both of them are finished smoothly as in the conventional case and the infinite number of concave portions 136 are arranged. It can be seen that the unstable behavior can be suppressed and the wear state of the sliding surface 138 can be reduced.

  Next, a friction test was performed using a test piece that was subjected to a projection process after lapping the sliding surface of the ring-shaped sliding member 12 formed of a material having relatively high hardness (high chromium steel).

  Next, the results of the friction experiment will be described with reference to FIG.

  In order to evaluate the friction and wear characteristics of the first embodiment, various parameters using the opening area ratio and surface roughness of the recess 136 of the sliding surface 138 of the ring-shaped sliding member 12 and the depth of the recess 136 as parameters. The specifications of the conditions are shown in (Table 3). The mating disk-shaped sliding member 10 has a smooth surface of Ra0.1 only after lapping.

  6 (a) and 6 (b) are characteristic diagrams showing the relationship between the friction coefficient and the friction distance with the form of the sliding surface 138 in the first embodiment of the present invention as a parameter. In both cases, the friction distance is shown on the x-axis and the friction coefficient is shown on the y-axis.

  FIG. 6A shows the results of Comparative Example 1 Condition 1 and Comparative Example 1 Condition 4. Comparative Example 1 Condition 1 does not perform the projection process, both the ring-shaped sliding member 12 and the disk-shaped sliding member 10 are smooth surfaces, and the surface roughness of both sliding surfaces 138 is Ra 0.1 or less. Comparative Example 1 Condition 4 is formed by colliding a myriad of conventional projection particles 124 with the sliding surface. The opening area ratio of the recess 136 of the sliding surface 138 is 60%, and the surface roughness of the sliding surface 138 is. Ra 0.52 and the depth of the recess 136 is 3.2 μm. It is a so-called satin finish.

  The friction coefficient of Comparative Example 1 Condition 4 changed between 0.10 and 0.15, and showed large fluctuations and unstable behavior. As a result of confirming the state of the sliding surface 138 after the experiment was completed, It was confirmed that several sliding scratches that may be caused by abrasive wear were generated.

On the other hand, in Comparative Example 1 Condition 1, the friction coefficient changed between 0.10 and 0.15 and showed a large fluctuation, and the friction coefficient increased rapidly to about 0.3 when the friction distance was around 1100 m. The experiment was stopped because it was judged that burn-in had occurred. As a result of confirming the state of the sliding surface 138 after the experiment was completed, it was confirmed that the sliding surface 138 of the disc-shaped sliding member 10 was particularly severely damaged by the progress of adhesive wear.

  On the other hand, FIG. 6B shows the results of Example 1, Condition 3, Example 1, Condition 4, Example 1, Condition 5, Example 1, Condition 6, and Example 1, Condition 7, which are the first embodiment. ing. In the condition 3 of Example 1, the opening area ratio of the recess 136 is 35%, the surface roughness of the sliding surface 138 is Ra 0.38, and the depth of the recess 136 is 2.4 μm. In the condition 1 of Example 1, the opening area ratio of the recess 136 is 34%, the surface roughness of the sliding surface 138 is Ra 0.37, and the depth of the recess 136 is 2.6 μm.

  In Example 1, Condition 5 is that the opening area ratio of the recess 136 is 26%, the surface roughness of the sliding surface 138 is Ra 0.28, and the depth of the recess 136 is 1.8 μm. In Example 1, condition 6 is that the opening area ratio of the recess 136 is 10%, the surface roughness of the sliding surface 138 is Ra 0.15, and the depth of the recess 136 is 1.6 μm. In Example 1, Condition 7 is that the opening area ratio of the recess 136 is 5%, the surface roughness of the sliding surface 138 is Ra 0.09, and the depth of the recess 136 is 1.6 μm.

  In FIG. 7, the microscope picture of the sliding surface 138 of Example 1 conditions 6 which are this Embodiment is shown. It can be seen from FIG. 7 that the concave portion 136 and the flat portion 137 are clearly separated on the sliding surface 138.

  Furthermore, from FIG. 6B, in Example 2, Condition 4, Condition 4, and Condition 5 in which the opening area ratio is 26 to 35%, although the behavior is unstable, the friction coefficient is not accompanied by a large fluctuation range. It turns out that it has changed between 0.1-0.15. Compared with Comparative Example 1 Condition 4 and Comparative Example 1 Condition 5, even when the friction distance reaches 1750 m, the coefficient of friction changes between 0.1 and 0.15, but the fluctuation range is small and seizure does not occur. .

  In addition, as a result of confirming the state of the sliding surface 138 after the experiment, although the sliding scratches and wear have occurred, the damage state is remarkably relieved as compared with the condition 1 of the comparative example 1 and the condition 1 of the comparative example 1. It was confirmed that

  Furthermore, in the case of Example 1 Condition 6 in which the area ratio is 10% and Example 1 Condition 7 in which the area ratio is 7%, the friction coefficient changes around 0.05, and its fluctuation and behavior are extremely small. I understand. In addition, as a result of observing the state of the sliding surface 138 after completion of the experiment, the damaged state was extremely slight.

  Here, the experimental results shown in FIGS. 5A and 5B and FIGS. 6A and 6B are considered as follows.

  FIG. 8 is a condition range diagram of the opening area ratio and the surface roughness with respect to the friction coefficient characteristics and the superiority or inferiority of the wear state.

  8 is based on the experimental results of FIGS. 5 and 6, the x-axis is the opening area ratio of the recess 136 of the sliding surface 138, and the y-axis is the surface roughness of the sliding surface 138. The friction coefficient characteristics and the superiority or inferiority of the wear state are schematically shown for the combination of surface roughness.

  In FIG. 8, the case where the recess 136 is provided in the sliding member having the lower hardness among the opposing sliding members (result of FIG. 5) is indicated by a circle (◯), and the relative sliding member Of these, the case where the concave portion 136 is provided in the sliding member with higher hardness (result of FIG. 6) is indicated by a triangle mark (Δ).

Also, for these circle marks and triangle marks, those judged to be inferior in friction coefficient characteristics and wear state are black (filled), and are judged to be superior in friction coefficient characteristics and wear state at least as compared with the comparative example. The right half is black, and the one that is judged to be significantly superior is white (not painted).

  The case where the smooth surfaces are not provided with the recess 136 is indicated by a square mark (■) painted black. The opening area ratio when the innumerable recesses 136 are provided as in the conventional case is 60% or more.

  From FIG. 8, it can be determined that the friction coefficient characteristics and the wear state are good when the opening area ratio of the recess 136 is in the range of 5 to 50% as shown in the region A surrounded by the broken line.

  It can also be seen that the opening area ratio of the recess 136 and the surface roughness Ra of the sliding surface 138 are in a linear function relationship with a substantially positive slope. As shown in the region B surrounded by the broken line and the alternate long and short dash line in FIG. 8, the opening area ratio of the recess 136 is 5 to 50% and the surface roughness Ra of the sliding surface 138 is 0.4 or less. For example, the friction coefficient characteristics and the wear state are good, and as shown in the region C surrounded by the broken line and the dotted line, the opening area ratio of the recess 136 is 5 to 20% and the surface roughness Ra is 0.3 or less. Thus, it can be seen that the friction coefficient characteristics and the wear state are remarkably good.

  In addition, the depth of each recessed part 136 is described in the vicinity of each plot in the figure. It can be seen that the depth of the recess 136 of the sliding surface 138, which is considered to have good friction coefficient characteristics and wear, is 1.0 to 3.0 μm.

  FIGS. 9A and 9B are schematic diagrams for explaining the comparison between the sliding state of the first embodiment and the conventional configuration.

  Here, FIG. 9A shows the lubrication state in the first embodiment, and FIG. 9B shows the lubrication state in the conventional form (Comparative Example 1). 9 (a) and 9 (b), the sliding member 130 and the mating sliding member 132 (in the conventional case, the sliding member 32 and the mating sliding member 30) are opposed to each other. The figure shows the state before sliding, and the figure below the arrow shows the lubrication state during sliding.

  As shown in FIG. 9A, when the recess 136 is formed on the sliding surface 138, an oil ball 139 is formed in each recess 136, and when the sliding is started, the oil ball 139 of each recess 136 is started. Are connected to each other, and an oil film 140 is formed over the entire sliding surface.

  In the first embodiment, the lubricant is provided on the sliding surface 138 of the sliding member 132 even under the condition that the lubricating oil is consumed as the sliding time elapses and the supply of the lubricating oil from the outside is delayed. When the load is received by the flat portion 137, the sliding surface pressure is effectively dispersed, and the lubricant accumulated in the recess 136 oozes out to the flat portion 137 of the sliding surface 138, thereby reducing adhesion wear. I think it is possible.

  Further, even if wear occurs in the flat portion 137, it is considered that the abrasive wear can be reduced by collecting the generated wear powder in the recess 136.

  On the other hand, as shown in FIG. 9 (b), in the conventional case in which the innumerable recesses 36 are formed on the sliding surface 38, when the oil balls 139 are formed in the respective recesses 36 and sliding is started, The oil balls 139 in the recess 36 are connected to each other, and an oil film 140 is formed over the entire sliding surface.

  However, in the case where an infinite number of recesses 36 are provided on the sliding surface 38 of the conventional sliding member 32 so as to have a matte shape, the number of flat portions 137 as shown in FIG. 9A is very small. When the lubricating oil is consumed as the sliding time elapses and the supply of lubricating oil from the outside is delayed, the fine seam 141 between the concave portions 36 is used instead of the flat portion 137 described above. It is considered to receive a load.

  Since the pressure receiving area is very small and the surface pressure is locally increased, wear starting from the seam 141 is generated, and the recess 136 seems to disappear relatively early.

  Therefore, it is important to set an appropriate opening area ratio of the concave portion 136 on the sliding surface 138 and to mix the concave portion 136 and the flat portion 137 at an appropriate ratio.

  The above consideration is as shown in the results of Example 1 Condition 4 and Example 1 Condition 5 in which the recess 136 is provided in the sliding surface 138 of the sliding member having higher hardness among the opposing sliding members. In the case where the concave portion 136 is provided on the sliding surface of the sliding member having the higher hardness among the opposing sliding members, even when the friction distance reaches 1750 m, the friction coefficient changes significantly low, This is considered to be supported from the fact that the life of the moving member can be extended.

  That is, when the concave portion 136 is provided on the sliding surface of the sliding member having the higher hardness among the sliding members facing each other, the concave portion 136 is provided on the sliding surface of the sliding member having the lower hardness. Since the progress of wear is small in comparison, it is considered that the effect as an oil sump by the recess 136 lasted for a long time.

  Furthermore, in the conventional case, since the innumerable concave portions 36 are formed by projecting a large amount of projection particles onto the sliding surface, the sliding outermost surface of the sliding member may be weakened. When the projecting particles repeatedly collide with or in the vicinity of the recess 36 once formed on the sliding surface, the sliding outermost surface of the sliding member becomes brittle due to the repeatedly applied collision energy, or It is considered that a crack or a crack is formed around the depression.

  Such brittleness and generation of cracks on the outermost surface cannot withstand long-term friction, peel off in the middle, and bite between sliding members, scratching the sliding surface, increasing friction loss and It may be difficult to ensure reliability.

  From the above results, according to the first embodiment, the entire sliding surface 138 of at least one sliding member 132 of the two sliding members 130 and 132 arranged so that one slides with respect to the other. Alternatively, a dimple-like recess 136 is provided in a certain region of the sliding surface 138, and the opening area ratio is set to 50% or less, so that when a load is applied, a flat portion on the sliding surface 138 is formed. The load is received by the surface, and the lubricating oil held in the recess 136 oozes out to the flat portion, so that friction loss and wear are reduced even under more severe sliding conditions, and highly reliable sliding is achieved. A moving member can be provided.

  That is, instead of simply providing an infinite number of recesses 136 on the sliding surface 138 of the sliding member 132, the oil reservoir effect by the recesses 136 is maximized by appropriately setting the opening area ratio of the recesses 136 on the sliding surface. It can be demonstrated. Here, it is considered that when the opening area ratio is less than 5%, the shape of the lubricating oil is substantially the same as the conventional smooth surface shape. Therefore, it is considered that it is preferable to make the opening area ratio in the range of 5% to 50%, more desirably in the range of 5% to 20%, in order to further reduce the friction loss.

  In the case where the dimple-shaped recess 136 is provided only in a certain region of the sliding surface, the boundary between the region where the recess 136 is not provided and the certain region where the recess 136 is provided is the maximum of the provided dimple-like recess 136. By considering the outer end portion, it is easy to calculate the opening area ratio of the present application.

In addition, it is possible to realize low friction loss by setting the surface roughness Ra of the sliding surface 138 in which the concave portion 136 is formed to 0.4 or less, and preferably Ra 0.3 or less. That is, even under conditions where the supply of lubricating oil from the outside is stagnant, the oil film of the contact sliding portion due to the rough surface of the sliding surface 138 and the lubrication in which the concave portion 136 is held through the surface roughness. It is possible to reduce the friction loss of the sliding member 132 by preventing the oil from flowing out.

  Further, by setting the depth of the recess 136 to 3.0 μm or less, and more desirably 2.0 μm or less, it is possible to realize a low friction loss. Even under conditions where supply of lubricant from the outside is stagnant, by setting the appropriate depth of the recess 136 so that the lubricant retained in the recess 136 effectively oozes out into the contact sliding portion, The friction loss of the sliding member can be reduced.

  Furthermore, wear of the recess 136 on the sliding surface of the sliding member with higher hardness is more advanced than the case of providing the recess 136 on the sliding surface of the sliding member with lower hardness. Since it is small, the effect of the oil reservoir by the recess 136 can be maintained for a long time.

  In addition, when the concave portion 136 is formed by the shot peening apparatus 121, a bulge 142 may be generated around the concave portion 136 depending on conditions for projection.

  FIG. 10 shows a schematic view of the ridge 142. Up to now, there has been a ridge 142 having an acute angle shape as shown in FIG. 10A and a ridge 142 having a gentle undulation as shown in FIG. 10B.

  However, when the concave portion 136 is provided in the sliding member having a lower hardness, the ridge 142 is instantaneously lost by abrasion, so that damage and wear of the sliding surface 138 starting from the ridge 142 can be suppressed.

  However, it is more desirable to adjust the conditions for projecting projected particles with the shot peening apparatus 121 so that the ridge 142 does not occur or even if it occurs, the height h of the ridge 142 is suppressed to the submicron order. In addition, it is desirable to remove the ridges 142 in advance by buffing or the like after the projection process in the shot peening apparatus 121.

  The present invention can be applied to various sliding members of various devices. The material and surface properties (initial surface roughness) of the sliding members, the operating conditions, the supply state of the lubricating oil, and the oil properties (viscosity) The proper specifications of the recess 136 may be determined according to the oil type and the like.

  As a specific example, there is a sliding member of a reciprocating compressor which is one of the compressors for the refrigeration cycle. FIG. 11 shows a longitudinal sectional view of a reciprocating compressor.

The following are common sliding members of the current reciprocating compressor 150.
(1) Since the shaft main shaft 151 and the main bearing 152 have a cantilever bearing structure, the upper and lower ends of the main bearing 152 may cause one-side contact. Both materials are made of cast iron. The main shaft 151 is subjected to a manganese phosphate coating treatment on the surface, and the main shaft 151 has a slightly lower hardness than the main bearing 152. Both sliding surfaces are finished to Ra 0.5 or less.
(2) With respect to the thrust bearing portion 153, the crankshaft 163 is inclined in the main bearing 152 in the refrigerant suction compression stroke, so that the thrust sliding surface 154 on the main shaft side and the thrust sliding surface 155 on the main bearing side are on the outer peripheral side. There is a possibility that one-sided contact may occur, and the oil film pressure is unlikely to be generated due to planar contact. The main shaft side thrust sliding surface 154 and the main bearing side thrust sliding surface 155 are both made of cast iron, and the main shaft side thrust sliding surface 154 is generally treated with a manganese phosphate coating. The thrust sliding surface 154 has a slightly lower hardness. Both sliding surfaces are finished to a surface roughness Ra of 0.5 or less.
(3) With respect to the shaft eccentric shaft 156 and the connecting rod large end hole 157, there is a possibility that one-side contact may occur at the upper and lower ends of the connecting rod large end hole 157 in the refrigerant suction compression stroke. The shaft eccentric shaft 156 is made of cast iron, the connecting rod 158 is made of an aluminum alloy, and both surfaces are Ra.
Finished to 0.5 or less.
(4) With respect to the piston pin 159 and the connecting rod small end hole 160, since the piston pin 159 swings in the connecting rod small end hole 160, the oil film is less likely to be formed compared to the rotational movement in a certain direction, and the sliding area is other. Compared with the sliding portion, the surface pressure is small and the surface pressure is high. The piston pin 159 is made of chrome steel, the connecting rod 158 is made of an aluminum alloy, and both sliding surfaces are finished to Ra 0.5 or less. The piston pin 159 is generally surface hardened or hardened by nitriding.
(5) With respect to the piston 161 and the cylinder bore 162, the crankshaft 163 is tilted in the main bearing 152 in the refrigerant suction compression stroke, and the piston is tilted in the vertical direction when the reciprocating compressor 150 is viewed from the side. This is a configuration in which one-side contact may occur at the end. The piston 161 is made of sintered, and the surface is treated with manganese phosphate. One cylinder bore 162 is made of cast iron and has a slightly lower hardness than the piston 161. Both sliding surfaces are finished to Ra 0.5 or less.

  In the above-described combination of sliding members, the present invention is considered to be extremely effective particularly for the boundary and the region where the sliding is assumed in the mixed lubrication region (the region where the sliding members are in contact with each other). . In other words, for parts that are easily hit by one part or parts that have a relatively high surface pressure, the rotational speed, surface pressure, and actual use of the sliding member facing each other is low or high, or on both sides. By providing a concave portion 136 having an appropriate opening area ratio corresponding to viscosity and the like, surface roughness, and depth, it is possible to improve the lubrication state and realize high efficiency and high reliability of the reciprocating compressor 150. it can.

  As another specific example, there is a sliding member of a rotary type compressor which is one of the compressors for the refrigeration cycle. FIG. 12 shows a longitudinal sectional view of the rotary compressor.

The following are common sliding members of the current rotary compressor 170.
(1) With respect to the shaft main shaft 171 and the main bearing 172, and the shaft sub shaft 173 and the sub bearing 174, the end portions of the main bearing 172 and the sub bearing 174 are likely to hit each other. The crank main shaft 171 and the crank sub-shaft 173 are integrally molded and made of cast iron, and the sliding surface is treated with a manganese phosphate coating. One of the main bearings 172 and the auxiliary bearings 174 is made of sintered material, and has a lower hardness than the main shaft 171 and the auxiliary shaft 173. Both sliding surfaces are finished to Ra 0.5 or less.
(2) Since the vane side surface 175 and the cylinder vane groove 176 are reciprocating, the oil film pressure is hardly generated. The vane side surface 175 is made of steel, and the cylinder vane groove 176 is made of cast iron. Both sliding surfaces are finished to Ra 0.5 or less.
(3) The vane tip 177 and the roller 178 have a configuration in which the surface pressure becomes extremely high due to linear contact sliding. The vane tip 177 is made of steel, and its sliding surface (tip) is hardened with a ceramic film formed by PVD or CVD. One roller 178 is made of cast iron. Both sliding surfaces are finished to Ra 0.5 or less.

  In the above-described combination of sliding members, the present invention is considered to be extremely effective particularly for the boundary and the region where the sliding is assumed in the mixed lubrication region (the region where the sliding members are in contact with each other). .

  That is, for parts that are easily hit by one part or parts that have a relatively high surface pressure, the rotational speed, the surface pressure, and the actual service viscosity are low on the sliding member facing each other, on the one with low hardness, or on the other with high hardness. By providing the concave portion 136 having an appropriate opening area ratio, surface roughness, and depth corresponding to the above, it is possible to improve the lubrication state and realize high efficiency and high reliability of the rotary compressor 170. .

Furthermore, as another specific example, there is a sliding member of a scroll compressor which is one of the compressors for the refrigeration cycle. FIG. 13 is a longitudinal sectional view of the scroll compressor.

The following are common sliding members of the current scroll compressor 180.
(1) The shaft main shaft 181 and the main bearing 182, the shaft eccentric shaft 183 and the eccentric bearing 184, and the shaft sub shaft 185 and the sub bearing 186 are structurally separated at the upper and lower ends of the main bearing 182, the eccentric bearing 184 and the sub bearing 186. This is a configuration that is likely to hit. The shaft main shaft 181, the shaft eccentric shaft 183, and the shaft counter shaft 185 are all made of steel and hardened on the surface by nitriding treatment.

One of the main bearing 182, the eccentric bearing 184, and the auxiliary bearing 186 are all molded from a composite material of resin and carbon whose back metal is a metal, and has higher hardness than the shaft 187. The sliding surfaces of the shaft main shaft 181, the shaft eccentric shaft 183, and the shaft counter shaft 186 are all finished to Ra 0.5 or less.
(2) The thrust bearing portion 190 formed by the fixed scroll 188 and the orbiting scroll 189 has a configuration in which oil film pressure is relatively difficult to generate due to planar contact. The fixed scroll 188 is made of cast iron, the orbiting scroll 189 is made of an aluminum alloy, and the surface is hardened by anodizing. Both sliding surfaces are finished to Ra 0.5 or less.

  In the above-described combination of sliding members, the present invention is considered to be extremely effective particularly for the boundary and the region where the sliding is assumed in the mixed lubrication region (the region where the sliding members are in contact with each other). .

  That is, for parts that are easily hit by one part or parts that have a relatively high surface pressure, the rotational speed, the surface pressure, and the actual service viscosity are low on the sliding member facing each other, on the one with low hardness, or on the other with high hardness. By providing a recess having an appropriate opening area ratio, surface roughness, and depth corresponding to the above, it is possible to improve the lubrication state and realize high efficiency and high reliability of the scroll compressor.

(Embodiment 2)
14 is a schematic top view of the sliding surface of the sliding member according to Embodiment 2 of the present invention, FIG. 15 is a schematic sectional view of the sliding surface of the sliding member according to Embodiment 2, and FIG. The schematic diagram of the equipment used for the manufacturing method of the sliding member in Embodiment 2, FIG. 17 shows sectional drawing of the metal mold | die used for manufacture of the sliding member in Embodiment 2. FIG. FIG. 18 is a perspective view of a friction experiment device for evaluating the friction characteristics of the sliding member in the second embodiment, and FIG. 19 is a parameter of the form of the sliding surface of the sliding member in the second embodiment. 20 is a characteristic diagram showing the relationship between the friction coefficient and the sliding distance, and FIG. 20 is a characteristic correlation diagram between the number of bearing characteristics and the friction coefficient with different forms of the sliding surface of the sliding member in the second embodiment as parameters. 21 is a characteristic correlation diagram of the number of bearing characteristics and the friction coefficient in consideration of the opening area ratio of the sliding member in the second embodiment. FIG. 22 is a characteristic diagram showing the relationship between the friction coefficient and the sliding distance using the sliding surface configuration as a parameter when the sliding member conditions in the second embodiment are changed, and FIG. FIG. 24 is a characteristic correlation diagram of the number of bearing characteristics and the coefficient of friction with the different form of the sliding surface of the sliding member in FIG. 2 as parameters, and FIG. 24 considers the opening area ratio of the concave portion 233 of the sliding surface in the second embodiment. FIG. 5 is a characteristic correlation diagram between the number of bearing characteristics and the friction coefficient.

  14 and 15, the sliding members 231 and 231a are made of a metal material, and at least one of two sliding members 231 and 231a arranged so that one slides with respect to the other. About. The sliding surface 232 of one sliding member 231 is formed with a number of dimple-like recesses 233 and a minute groove 235 formed by a continuation of a number of minute recesses 236. Here, the area of one minute recess 236 is set smaller than the area of the recess 233.

The fine groove 235 is formed by using the above-described machining center (not shown) for forming the fine concave portion 236 on the surface of the sliding member 231, and the distance L between the centers of the adjacent fine grooves 235 and the crossing angle α are arbitrary ( In the second embodiment, the machining streak is set to 90 °.

  Note that an arrow X in FIG. 14 indicates the sliding direction of the sliding member 231.

  The concave portion 233 is formed by pressing the mold 241 provided with the convex portion 242 shown in FIG. 17 against the surface of the sliding member 231 by the press facility 240 shown in FIG.

  The mold 241 is produced by photo-etching the surface of a steel plate that is harder than the material of the sliding member 231, and the convex portions 242 of any shape (diameter, height, etc.) are uniformly distributed at predetermined locations. doing.

  Then, according to the material properties (material type, hardness, enclosing void, density, etc.) of the sliding member 231, the load and speed conditions of the press facility 240 when the convex portion 242 is pushed into the surface of the sliding member 231. By adjusting, the opening diameter and depth of the recess 233 formed in the sliding member 231 can be controlled.

  In addition, the convex portion 242 formed on the die 241 is formed by appropriately placing the die 241 in the entire sliding surface 232 of the sliding member 231 or in a certain region of the sliding surface 232 and performing press working. As described above, the recess 233 can be formed on the surface of the sliding member 231. Therefore, the opening area ratio of the sliding surface 232 can be adjusted by adjusting and setting the size (projection size, diameter, etc.) of the convex portion 242 provided in the mold 241 and the width size of the fine groove 235. it can.

  And after forming the fine groove 235 and the recessed part 233, the surface of the sliding member 231 is grind-finished and the flat part 234 is formed.

  Here, the opening area ratio is the total area of the opening portion (non-contact portion) area of the recess 233 and the opening portion (non-contact portion) area of the fine groove 235 with respect to the area of the sliding surface 232 in the sliding member 231. Means the percentage of Therefore, in the following description, the sliding surface 232 will be described not as a surface of only the portion that contacts the sliding member 231a but as a region that includes the concave portion 233 and the flat portion 234 and is in contact with the sliding member 231a. .

  In other words, in the second embodiment, first, the extending directions of the adjacent fine grooves 235 are set to be orthogonal to each other, and in this state, the extending direction of at least a part of the fine grooves 235 in the fine grooves 235 is set. The sliding member 231 is set to be parallel to the sliding direction. Then, the machining center or the sliding member 231 is moved in the extending direction of the fine groove 235 by the machining center, and the fine groove 235 is formed.

  At this time, the cross-sectional shape orthogonal to the extending direction in the fine groove 235 is formed in a substantially triangular shape because of the processing jig.

  Thereafter, the dimple-shaped recess 233 is formed in the rectangular frame 237 (flat portion 234) surrounded by the minute grooves 235 using the mold 241 as described above.

  Moreover, in this Embodiment 2, the surface shape of the recessed part 242 is made into a substantially spherical surface by using the metal mold | die 241 which has the substantially circular arc-shaped convex part 242. FIG. Therefore, the opening of the concave portion 242 is substantially circular when the sliding surface 232 is viewed from above, and the cross-sectional shape when the sliding surface 232 is cut along a vertical surface is substantially circular.

  The friction characteristics of the sliding member 231 in which the concave portion 233 and the fine groove 235 are formed by the manufacturing process as described above were evaluated by a ring-on-disk experimental apparatus.

  FIG. 18 is a perspective view of a friction test apparatus for evaluating the friction characteristics of the sliding member according to the second embodiment. Since the basic configuration of this friction test apparatus is the same as that shown in FIG. 4, the same constituent elements as those shown in FIG.

  In the friction test apparatus shown in FIG. 18, a ring-shaped sliding member 12 and a disk-shaped sliding member 10 are mounted as two sliding members, and the ring-shaped sliding member 12 is connected via a drive member 14 and a pin 16. It is configured to rotate in a predetermined direction by the transmitted rotational force and to receive a load load from above via the stationary shaft 18.

  Further, in comparison with FIG. 4, a through hole 23 is provided on the side surface of the ring-shaped sliding member 12, and lubricating oil is supplied from the microsyringe 24 inserted into the through-hole 23 to the inner peripheral surface of the ring-shaped sliding member 10. The difference is that a configuration in which the flow is appropriately supplied to flow into the contact sliding portions of the two sliding members by the centrifugal force accompanying the rotation of the disk-shaped sliding member 10 is different.

  Accordingly, the disk-shaped sliding member 10 rotates while the ring-shaped sliding member 12 contacts the disk-shaped sliding member 10 with a predetermined pressure. Friction occurs. Note that a lubricating oil (oil film) (not shown) is formed between the two sliding members 10 and 12. Further, the guide portion 20 serves as a stationary shaft bearing, and the ball bearing 22 is aligned so that the ring-shaped sliding member 12 and the disk-shaped sliding member 10 are in contact with each other without contacting each other. It is responsible for the mechanism.

  In addition, the experimental conditions by the said friction experiment apparatus are as (Table 4).

  That is, the ring-shaped sliding member 12 was lapped with an outer diameter of 25.5 mm, an inner diameter of 20 mm, a material made of cast iron (FC250, hardness HV200 or so), and a surface roughness of Ra 0.1 to 0.2. One disk-shaped sliding member 10 is used, and the outer diameter is 27 mm, the material is cast iron (FC250, hardness HV200 or so), and the surface roughness is Ra 0.1 to 0.2. Is used. And the above-mentioned recessed part 233 and the fine groove 235 are formed in the sliding face 232 of the disk-shaped sliding member 10.

As operating conditions, the vertical load is 2 patterns of 6N and 22N, the sliding speed is 4 patterns of 0.06 m / s, 0.12 m / s, 0.23 m / s, and 0.6 m / s, and 40 Two kinds of lubricating oils having a viscosity of 68 mm ² / s and 3 mm ² / s at 0 ° C. were supplied to the contact sliding part at a rate of 0.023 mL per time, 4 times per minute, every 15 seconds during the test. Therefore, although it is a trace amount, lubricating oil flows into the contact sliding portion intermittently. The experiment was conducted in the atmosphere at room temperature.

Next, the results of the friction experiment will be described with reference to FIGS. 19 and 20. Also,
Table 5 shows the specifications used for evaluating the friction and wear characteristics of the second embodiment.

  The disk-shaped sliding member 10 (corresponding to the sliding member 231) in which the fine groove 235 and the concave portion 233 are processed on the sliding surface 232 is lapped as a final finish. Further, as a comparative example of the second embodiment, a disk-shaped sliding member 10 that is lapped and finished to have a smooth surface of Ra 0.1 and does not have the above-described concave portion 233 and fine groove 235 is used.

  In addition, the ring-shaped sliding member 12 (corresponding to the sliding member 231a) on the other side performs only lapping in each case, and has a smooth surface of Ra0.1.

  Here, the opening area ratio shown in (Table 5) indicates the ratio of the total area of the opening portion of the recess 233 to the area of the sliding surface 232 where the ring-shaped sliding member 12 and the disk-shaped sliding member 10 are in contact. The area of the opening of the fine groove 235 is not included. Therefore, the substantial opening area (non-contact area) rate described in each example is a numerical value obtained by adding the opening portion area of the fine groove 235 to the numerical value described in (Table 5), and increases by several percent.

  Specifically, as in the first embodiment, a part of the sliding surface 232 of the sliding member 10 is captured by a laser microscope to perform computer image processing, and the opening area of the opening of each recess 232 Is divided by the total area of the sliding surface 232 used for image processing to obtain the aperture area ratio. In addition, the average value of the opening area ratio obtained by changing the measurement location several times was used as the representative value under the conditions.

  As for the surface roughness of the flat portion 234 of the sliding surface 232, as in the first embodiment, the average value obtained by measuring several times with a stylus type shape measuring machine and the depth of the concave portion 233 are determined by laser. The average value of the result measured several times with a microscope is shown.

FIG. 19 shows the parameters of the sliding surface 232 in the second embodiment of the present invention using a lubricating oil having a viscosity of 68 mm ² / s (40 ° C.), a vertical load of 6 N, and a sliding speed of 0.6 m / s. FIG.

Further, FIG. 20 uses a lubricating oil having a viscosity of 68 mm ² / s at 40 ° C., a vertical load of 6 N, sliding speeds of 0.06 m / s, 0.12 m / s, 0.23 m / s, 0 FIG. 6 is a characteristic correlation diagram between the number of bearing characteristics and the coefficient of friction with the sliding surface 232 according to the second embodiment of the present invention as a parameter in the case of .6 m / s. Here, the x-axis bearing characteristic number is an index of the severity of lubrication, and is a dimensionless number calculated by integrating the viscosity and the sliding speed and dividing the result by the surface pressure. Therefore, the smaller the number of bearing characteristics, the more severe the lubrication state. One y-axis friction coefficient is an average value of individual friction coefficients obtained during a movement distance of 180 m to 360 m (end of experiment).

As shown in FIG. 20, as the number of bearing characteristics decreases, the friction coefficient tends to decrease in any of the evaluation specifications.

  That is, in this experimental condition, the lubrication state is such that the influence of the friction coefficient caused by the viscosity of the lubricating oil is larger than the friction coefficient caused by the solid (metal) contact between the sliding members during sliding. This is because, as a result of confirming the sliding surfaces of the ring-shaped sliding member 12 and the disk-shaped sliding member 10 after the experiment, scratches and wear due to sliding are hardly detected in each case, or are very slight. It is supported by what was.

  In such a lubrication state, also from FIG. 19, Example 2 in which a recess 233 having a depth of 2.5 μm and an opening area ratio of 15% was formed on the sliding surface 232, condition 2 was 9 μm and the opening area ratio was 9 μm. In Example 2 Condition 1 in which the concave portion 233 of 30% is formed, the friction coefficient is smaller than that in Comparative Example 2 Condition 1 in which both the conventional ring-shaped sliding member and the disk-shaped sliding member are smooth surfaces. I can be.

  Further, in the case of the recess 233 having a depth of 2.5 μm and an opening area ratio of 15%, the reduction width of about 10%, whereas in the case of the recess 233 having a depth of 9 μm and an opening area ratio of about 30%, The reduction is 50%. Furthermore, it can be seen that the friction coefficient tends to decrease when used in combination with the fine groove 235.

  From these results, in the lubricating region where the influence of the viscosity of the lubricating oil is relatively large, the viscosity of the lubricating oil is reduced by reducing the sliding area by the concave portion 233 and the fine groove 235 (the fine concave portion 236) provided on the sliding surface. It is thought that the resistance was reduced and the friction loss was reduced.

  FIG. 21 is a characteristic correlation diagram of the number of bearing characteristics and the friction coefficient in consideration of the opening area ratio of the concave portion 233 of the sliding surface with respect to FIG. That is, the increase in the surface pressure due to the reduction of the sliding area corresponding to the opening area ratio is taken into account, and the friction coefficient data slides substantially in parallel with the smaller number of bearing characteristics.

  From this result, the friction coefficient of Condition 2 in Example 2 in which the concave portion 233 having a depth of 2.5 μm and an opening area ratio of 15% was formed on the sliding surface 232 is the same as that of the conventional ring-shaped sliding member and the disk-shaped sliding member. Both of the moving members are substantially collinear with Comparative Example 2 Condition 1 in which both are smooth surfaces. Further, the friction coefficient in Example 2 Condition 4 in which the fine groove 235 having a depth of 2.5 μm is provided is slightly smaller than that in Comparative Example 2 Condition 1.

  On the other hand, the friction coefficient of Condition 1 of Example 2 in which the recess 233 having a depth of 9 μm and an opening area ratio of 30% was formed, compared with the conventional Comparative Example 2 Condition 1 even when the opening area ratio of the recess 233 was taken into consideration. Remarkably small. Further, in Example 2 Condition 3 in which the fine groove 235 having a depth of 2.5 μm is provided, the friction coefficient is further smaller than that in Comparative Example 2 Condition 1.

  From these facts, in the lubrication state where the influence of the friction coefficient caused by the viscosity of the lubricating oil is large, when the concave portion 233 and the fine groove 235 (the fine concave portion 236) are shallow, the sliding area is reduced by the concave portion 233 and the fine groove 235. It seems to be the main factor of the decrease in frictional resistance. On the other hand, when the concave portion 233 and the fine groove 235 are deep, in addition to the reduction of the sliding area by the concave portion 233 and the fine groove 235, for example, the labyrinth effect acts to increase the clearance between the contact sliding portions. Sex is suggested.

However, considering the general Stribeck characteristics, if the sliding area by the concave portion 233 or the fine groove 235 is further reduced, the metal contact mainly becomes a lubrication state and the friction coefficient starts to increase. Depending on sliding conditions such as speed, viscosity of lubricant (lubricating oil), oil properties of lubricant (lubricating oil), supply conditions, etc., recess 233 and micro groove 235 (micro recess 2
It is desirable to find out the appropriate maximum specifications (depth, opening area ratio, etc.) of the shape of 36).

Next, FIG. 22 shows a sliding surface according to the second embodiment of the present invention, using a lubricating oil having a viscosity of 68 mm ² / s (40 ° C.), a vertical load of 22 N, and a sliding speed of 0.23 m / s. It is a characteristic view which shows the relationship between the friction coefficient which used 232 as a parameter, and a sliding distance.

Further, FIG. 23 uses a lubricating oil having a viscosity of 3 mm ² / s (40 ° C.) different from the case of FIG. 20, a vertical load of 22 N, sliding speeds of 0.06 m / s, 0.12 m / s, FIG. 10 is a characteristic correlation diagram between the number of bearing characteristics and the coefficient of friction using the sliding surface 232 in the second embodiment of the present invention as a parameter when 0.23 m / s and 0.6 m / s are set. Here, the x-axis bearing characteristic number is an index of the severity of lubrication, and is a dimensionless number calculated by dividing the result of integrating the viscosity and the sliding speed by the surface pressure. Therefore, the smaller the number of bearing characteristics, the more severe the lubrication state. One y-axis friction coefficient is an average value of individual friction coefficients obtained between a moving distance of 70 m and 140 m (end of experiment).

  From FIG. 23, it can be seen that as the number of bearing characteristics decreases, the friction coefficient tends to increase in any of the evaluation specifications.

  That is, under the present experimental conditions, the lubrication state is such that the influence of the friction coefficient generated by the solid (metal) contact between the sliding members during sliding is larger than the friction coefficient generated by the viscosity of the lubricating oil. This is because, as a result of confirming the sliding surfaces of the ring-shaped sliding member 12 and the disk-shaped sliding member 10 after the experiment, scratches and wear are caused by metal contact during sliding. It is supported. Further, the scratches and wear of the sliding surface in Comparative Example 2 Condition 1 in which both the conventional ring-shaped sliding member and the disk-shaped sliding member are smooth surfaces are the most scratched and worn. The sliding surface under the condition 2 of Example 2 where the depth was shallow was the slightest.

  In such a lubrication state, also from FIG. 23, Example 2 in which a recess 233 having a depth of 2.5 μm and an opening area ratio of 15% was formed on the sliding surface 232, condition 2 was obtained, the depth was 9 μm, and the opening area ratio. In Example 2 Condition 1 in which the concave portion 233 of 30% is formed, the friction coefficient is smaller than that in Comparative Example 2 Condition 1 in which both the conventional ring-shaped sliding member and the disk-shaped sliding member are smooth surfaces. I can be.

  In addition, in the case of the recess 233 having a depth of 9 μm and an opening area ratio of 30%, the reduction width of about 10%, whereas in the case of the recess 233 having a depth of 2.5 μm and an opening area ratio of about 15%, The reduction is 50%.

  These results show a tendency opposite to the result of FIG. 20 described above, which suggests that the smaller the depth of the recess 232 and the smaller the opening area ratio, the greater the reduction in the friction coefficient. . Further, it can be seen that the friction coefficient tends to be further reduced when used in combination with the fine groove 235.

  In FIG. 23, from Example 1 Condition 1 in which the recess 233 having a depth of 9 μm and an opening area ratio of 30% was formed, the sliding speed was 0.6 m / s and 0.23 m / s (the number of bearing characteristics). Is 2.0E-07, 9.0E-08), the friction coefficient is reduced, and further, when used in combination with the fine groove 235, the friction coefficient is further reduced as shown in Condition 3 of Example 2. I can see the trend.

  On the other hand, in Example 2 Condition 2 in which the concave portion 233 having a depth of 2.5 μm and an opening area ratio of 15% was formed, the friction coefficient was small under any condition, and the example was obtained by using together with the fine groove 235. 2 As shown in Condition 4, it can be seen that the friction coefficient tends to be further reduced.

  FIG. 24 is a characteristic correlation diagram of the number of bearing characteristics and the friction coefficient in consideration of the opening area ratio of the concave portion 233 on the sliding surface with respect to FIG. That is, the increase in the surface pressure due to the reduction of the sliding area corresponding to the opening area ratio is taken into account, and the friction coefficient data slides in parallel with the bearing characteristic number becoming smaller.

  From this result, the condition 1 in Example 2 in which the concave portion 233 having a depth of 9 μm and an opening area ratio of 30% was formed on the sliding surface 232 was as the number of bearing characteristics decreased, that is, the lubrication state became severe. Both the conventional ring-shaped sliding member and the disk-shaped sliding member tend to approach the condition 1 of Comparative Example 2 in which the friction coefficient is a smooth surface. In addition, the friction coefficient of Example 2 Condition 3 in which the fine groove 235 having a depth of 2.5 μm is provided is slightly smaller than that of Example 2 Condition 1 and Comparative Example 2 Condition 1.

  On the other hand, the friction coefficient of Example 2 Condition 2 in which the recess 233 having a depth of 2.5 μm and an opening area ratio of 15% was formed. Is significantly smaller than In addition, the coefficient of friction in Example 2 Condition 3 in which the fine groove 235 having a depth of 2.5 μm is provided is smaller than that in Comparative Example 2 Condition 1.

  From these results, in the lubrication region where the influence of the contact between the ring-shaped sliding member 12 and the disk-shaped sliding member 10 (metals) during sliding is relatively large, the recess 233 provided on the sliding surface. The minute recess 236 (fine groove 235) functions as a lubricant or lubricating oil holding portion, and is held in the minute recess 236 (fine groove 235) and the recess (233) even under severe sliding conditions. It is thought that the friction loss was reduced by effectively exuding the lubricant or lubricant to the flat part that receives the load.

  However, the appropriate minimum value of the shape of the concave portion 233 and the minute concave portion 236 (fine groove 235) depends on sliding conditions such as load, speed, viscosity of the lubricant (oil), oiliness of the lubricant (oil), supply conditions, and the like. It is advisable to check the situation.

  As shown in the first embodiment, a low friction loss can be realized by setting the depths of the recess 233 and the fine groove 235 to 3.0 μm or less from this result. In particular, even under conditions where supply of lubricant from the outside is stagnant, the lubricant retained in the recess 233 and the minute recess 236 (fine groove 235) effectively oozes out to the contact sliding portion. Thus, by appropriately setting the depth of the recess 233 and the minute recess 236 (fine groove 235), the friction loss of the metal sliding member (ring-shaped sliding member 12, disk-shaped sliding member 10) can be reduced. I think it can be reduced.

  From the above results, according to the second embodiment, the entire sliding surface 232 of at least one sliding member 231 of the two sliding members 231 and 231a arranged so that one slides with respect to the other. Alternatively, by providing the dimple-like recess 233 and the fine groove 235 in a certain region of the sliding surface 232, the sliding surface 232 is provided in a lubricating region where the influence of the viscosity of the lubricating oil is relatively large. By reducing the substantial sliding area due to the concave portion 233 and the fine groove 235 (small concave portion 236), the labyrinth effect, etc., the viscous resistance of the lubricating oil can be reduced and the friction loss can be reduced.

Further, in the lubrication region where the influence of the solid (metal) contact between the sliding members 231 and 231a during sliding is relatively large, the concave portion 233 provided on the sliding surface 232 and the fine groove 235 (small concave portion 236). ) Functions as a lubricant or lubricant holding part. As a result, even under severe sliding conditions such as conditions where the supply of lubricating oil from the outside is low, the lubricating oil held in the fine grooves 235 (small concave portions 236) and the concave portions 233 receives a load. By effectively exuding the flat portion 234 and suppressing the mutual contact between the sliding members 231 and 231a during sliding, friction loss and wear can be reduced, and a highly reliable sliding structure can be provided. it can.

  In the second embodiment, the depth of the fine grooves 235 formed by the large number of minute recesses 236 is set to be shallower than the depth of the recesses 233, thereby suppressing the surface strength of the sliding member 231 from decreasing. Can do.

  On the other hand, by setting the depth of the minute recess 236 (the minute groove 235) deeper than the depth of the recess 233, the condition that the lubricant or lubricating oil is appropriately supplied in an appropriate amount is used. This makes it possible to increase the amount of lubricant or lubricating oil retained. As a result, a sliding structure suitable for severe friction conditions such as a sliding structure with a high load or a sliding structure with a high friction speed can be obtained.

  In this way, by setting the shape, size, and the like of the recess 233 and the minute groove 235 (minute recess 236), sliding conditions such as load, speed, viscosity of the lubricant (oil), and lubricant (oil) A lubrication structure suitable for a sliding structure with different oiliness and supply conditions can be obtained, and a highly reliable sliding structure can be obtained. In particular, since the shape of the concave portion 233 depends on the shape of the convex portion 242 provided on the mold 241, the shape of the concave portion 233 may be an oval shape, an elliptical shape, a rounded square shape, or the like depending on the setting of the shape of the convex portion 242. it can.

  In the second embodiment, the fine groove 235, which is a lubricating oil supply oil passage, is formed by continuing the fine concave portion 236. However, the fine groove 235 can be formed as an intermittent groove with an appropriate length. In addition, it is possible to have a configuration in which micro grooves 235 having different lengths are combined. With these configurations, the lubricant on the surface of the sliding member 231 or the oil retaining property of the lubricating oil can be improved.

  In the second embodiment, the extending directions of adjacent fine grooves 235 are orthogonal to each other so that at least a part of the extending direction of the fine grooves 235 is parallel to the sliding direction of the sliding member. However, the extending direction of the fine groove 235 can be set to an appropriate angle with respect to the sliding direction in accordance with the sliding form of the sliding structure and various conditions.

  Further, in the second embodiment, as in the first embodiment, it can be applied to various sliding members of various devices, and the material and surface properties of the sliding member (initial surface roughness). Depending on the operating conditions, the supply state of the lubricating oil, and the oil properties (viscosity, oil type, etc.), the specifications of the appropriate recess 136 and minute recess 236 (fine groove 235) may be determined.

  Therefore, this Embodiment 2 is the case of the reciprocating compressor 150 shown in FIG. 11 described in the previous Embodiment 1, in addition to the effects described in the previous Embodiment 1, Effective action for any sliding structure in the mixed lubrication region (the region where sliding members come into contact with each other) or the fluid lubrication region (the region where the viscosity of the lubricant and lubricating oil is dominant) The effect can be expected.

  That is, a sliding surface is provided by providing a concave portion 233 or a minute concave portion 236 (fine groove 235) having an appropriate opening area ratio corresponding to the operating rotational speed, surface pressure, actual use viscosity and the like, and surface roughness and depth. It can be expected that the lubrication state of the reciprocating compressor 150 will be improved and the high efficiency and high reliability of the reciprocating compressor 150 will be realized.

Further, in the case of the rotary compressor shown in FIG. 12 described in the first embodiment, in addition to the effects described in the first embodiment, the boundary, mixed lubrication region (sliding member mutual An effective action and effect can be expected for any sliding structure in the region in which the fluid contacts and slides) or in the fluid lubrication region (region in which the viscosity of the lubricant is dominant).

  That is, a sliding surface is provided by providing a concave portion 233 or a minute concave portion 236 (fine groove 235) having an appropriate opening area ratio corresponding to the operating rotational speed, surface pressure, actual use viscosity and the like, and surface roughness and depth. It can be expected that the lubrication state of the rotary compressor 170 will be improved, and the efficiency and reliability of the rotary compressor 170 will be improved.

  Further, in the case of the scroll compressor shown in FIG. 13 described in the first embodiment, in addition to the operation and effect described in the first embodiment, the boundary, the mixed lubrication region (the sliding member mutual) An effective action and effect can be expected for any sliding structure in the region in which the fluid contacts and slides) or in the fluid lubrication region (region in which the viscosity of the lubricant is dominant).

  That is, a sliding surface is provided by providing a concave portion 233 or a minute concave portion 236 (fine groove 235) having an appropriate opening area ratio corresponding to the operating rotational speed, surface pressure, actual use viscosity and the like, and surface roughness and depth. It is expected that the lubrication state of the scroll compressor 180 will be improved and the high efficiency and high reliability of the scroll compressor 180 can be realized.

(Embodiment 3)
25 is a schematic top view of the sliding surface of the sliding member according to the third embodiment of the present invention, FIG. 26 is a schematic sectional view of the sliding surface of the sliding member according to the third embodiment, and FIG. The schematic diagram of the equipment used for the manufacturing method of the sliding member in the same Embodiment 3, FIG. 28 is sectional drawing of the metal mold | die used for manufacture of the sliding member in the same Embodiment 3. FIG. FIG. 29 is a characteristic diagram showing the relationship between the friction coefficient and the sliding distance, with the form of the sliding surface of the sliding member in the third embodiment as a parameter, and FIG. 30 is the characteristic of the sliding member in the third embodiment. FIG. 5 is a characteristic correlation diagram of the number of bearing characteristics and a friction coefficient with the form of the sliding surface as a parameter.

  25 and FIG. 26, the sliding members 331 and 331a are made of a metal material, and are related to at least one of the two sliding members 331 and 331a arranged so that one slides with respect to the other. . A large number of dimple-shaped recesses 333 and fine grooves 335 positioned between the recesses 333 are formed on the sliding surface 332 of one sliding member 331. Note that the arrow X indicates the sliding direction of the sliding member 331.

  The concave portion 333 and the fine groove 335 are pressed against the surface of the sliding member 331 by the press facility 340 shown in FIG. 27 with the die 341 provided with the substantially arc-shaped convex portion 342 shown in FIG. Formed by.

  That is, the mold 341 is made by photo-etching the surface of a steel plate that is harder than the material of the sliding member 331, and a convex portion 342 having an arbitrary shape with an appropriately set diameter, height, etc. is provided at a predetermined place. Almost evenly distributed.

  Therefore, the load and speed conditions of the press equipment 340 when the convex portion 342 is pushed into the surface of the sliding member 331 according to the material characteristics such as the material type, hardness, enclosing void, density, etc. of the sliding member 331 are determined. By adjusting, the opening diameter and depth of the recess 333 formed in the sliding member 331 can be controlled. In addition, by appropriately placing the mold 341 in the entire sliding surface 332 of the sliding member 331 or in a certain region of the sliding surface 332 and performing a pressing process, the convex portion 332 formed on the mold 341 is formed. As arranged, the recess 333 can be formed on the surface of the sliding member 231.

That is, in the process in which the convex portion 342 of the mold 341 is pushed into the surface of the sliding member 331, the periphery of the concave portion 333 formed on the surface of the sliding member 331 plastically flows, and the protrusion 337 is formed around the concave portion 333. Arise. In the third embodiment, the surface of the bump 337 is utilized as it is as the flat portion 334 that comes into contact with the mating sliding member.

  Further, the distance between the centers of the adjacent recesses 333 (hereinafter referred to as the pitch length) P is set to be longer than the sum W of the radius r of the adjacent recesses 342 and the width w of the ridges 337, so that the mutual recesses A flat portion 334 and a fine groove 335 are formed between 333. Here, the height of the flat portion 334 (bump 337) corresponds to the depth of the fine groove 335.

  In addition, the width w and flatness of the flat portion 334 and the depth of the fine groove 335 are determined by the press equipment 340 in accordance with the material properties such as the hardness of the sliding member 331, the voids included, and the density. It can be set and adjusted by adjusting the speed, and the opening area of the sliding surface 332 can also be adjusted.

  Here, the opening area ratio is the total area of the opening portion (non-contact portion) area of the recess 333 and the opening portion (non-contact portion) area of the fine groove 335 with respect to the area of the sliding surface 332 in the sliding member 331. Means the percentage of Therefore, in the following description, the sliding surface 332 is described not as a surface of only the portion that contacts the sliding member 331a but as a region that includes the concave portion 333 and the flat portion 334 and is in contact with the sliding member 331a. .

  In this manner, the concave portion 333, the flat portion 334 around the concave portion 333, and the fine groove 335 can be simultaneously formed by pressing the mold 341 having the convex portion 342 against the surface of the sliding member 331 under appropriate pressing conditions. Thus, it is possible to obtain the sliding member 331 that is rational and excellent in productivity.

  In addition, the concave portion 333 of the third embodiment uses a mold 341 having a substantially hemispherical convex portion 342, so that the surface shape of the concave portion 342 becomes spherical as in the second embodiment. The opening is substantially circular when the sliding surface 332 is viewed from above, and the cross-sectional shape when the sliding surface 332 is cut along a vertical surface is substantially arcuate.

  The friction characteristics of the sliding member 331 in which the concave portion 333 and the fine groove 335 are formed by the manufacturing process as described above were evaluated with the same contents using the ring-on-disk experimental apparatus described in the second embodiment. Therefore, the contents of Embodiment 2 and FIG. 18 are used here as an explanation of the experimental apparatus, and detailed explanations are omitted.

  In addition, the experimental conditions by the said friction experiment apparatus are as (Table 6).

  Here, the conditions of the ring-shaped sliding member 12 and the disk-shaped sliding member 10 are set to the same conditions as in the second embodiment.

The operating conditions were a vertical load of 6 N, sliding speeds of 0.06 m / s, 0.12 m / s, 0.23 m / s, and 0.6 m / s, and a lubrication with a viscosity of 68 mm ² / s at 40 ° C. Oil was supplied to the contact sliding part at a rate of 0.023 mL per minute, 4 times per minute, every 15 seconds during the test. Therefore, although it is a trace amount, lubricating oil flows into the contact sliding portion intermittently. The experiment was conducted in the atmosphere at room temperature.

  Next, the results of the friction experiment will be described with reference to FIGS. 29 and 30. FIG. Specifications using the friction and wear characteristics of Embodiment 3 for evaluation are shown in Table 7.

  Example 3 Condition 1 is that a flat portion 334 is formed by performing lapping after providing a recess 333 on the surface of the disk-like sliding member 10 (corresponding to the sliding member 331) by a press facility. In Example 3 Condition 2, the concave portion 333, the fine groove 335, and the flat portion 334 are formed on the surface of the sliding member 331 by a press facility. Further, as a comparative example of the third embodiment, a smooth surface of Ra0.1 in which neither the recess 233 nor the fine groove 235 is processed and only lapping is used is used for evaluation. On the other hand, the ring-shaped sliding member 12 (corresponding to the sliding member 331a) on the other side performs only lapping in any case and has a smooth surface of Ra0.1.

  Here, the opening area ratio shown in (Table 7) indicates the ratio of the total area of the opening portion of the recess 333 to the area of the sliding surface 332 where the ring-shaped sliding member 12 and the disk-shaped sliding member 10 contact. The area of the opening of the fine groove 335 is not included. Therefore, the substantial opening area (non-contact area) rate described in each example is a numerical value obtained by adding the opening portion area of the fine groove 335 to the numerical value described in (Table 7), and is an increasing numerical value of several percent. .

  Specifically, as in the first and second embodiments, a part of the sliding surface 332 of the sliding member 10 is captured by a laser microscope to perform computer image processing, and the openings of the individual recesses 332 are formed. The opening area ratio is obtained by dividing the sum of the opening areas by the total area of the sliding surface 332 used for image processing. In addition, the average value of the opening area ratio obtained by changing the measurement location several times was used as the representative value under the conditions.

  As for the surface roughness of the flat portion 334 of the sliding surface 332, as in the first and second embodiments, the average value obtained by measuring several times with a stylus type shape measuring machine, The depth of the groove 335 indicates an average value obtained by measuring several times with a laser microscope.

FIG. 29 shows a sliding surface 332 according to Embodiment 3 of the present invention, using a lubricating oil having a viscosity of 68 mm ² / s at 40 ° C., a vertical load of 6 N, and a sliding speed of 0.6 m / s. FIG.

In addition, FIG. 30 uses a lubricating oil having a viscosity at 40 ° C. of 68 mm ² / s, a vertical load of 6 N, sliding speeds of 0.06 m / s, 0.12 m / s, 0.23 m / s, 0 FIG. 6 is a characteristic correlation diagram between the number of bearing characteristics and the coefficient of friction using the sliding surface 332 in Embodiment 3 of the present invention as a parameter when the speed is set to 0.6 m / s. Here, the x-axis bearing characteristic number is an index of the severity of lubrication, and is a dimensionless number calculated by integrating the viscosity and the sliding speed and dividing the result by the surface pressure. Therefore, the smaller the number of bearing characteristics, the more severe the lubrication state. One y-axis friction coefficient is an average value of individual friction coefficients obtained during a movement distance of 180 m to 360 m (end of experiment).

  From FIG. 30, as the number of bearing characteristics decreases, the friction coefficient tends to decrease in any of the evaluation specifications.

  That is, in this experimental condition, the lubrication state is such that the influence of the friction coefficient caused by the viscosity of the lubricating oil is larger than the friction coefficient caused by the solid (metal) contact between the sliding members during sliding. As a result of checking the sliding surfaces of the ring-shaped sliding member 12 and the disk-shaped sliding member 10 after the experiment, almost no scratches or wear due to sliding are detected or very slight. It is supported by what happened.

  In such a lubrication state, Example 3 Condition 1 in which the concave portion 333 having a depth of 9 μm and an opening area ratio of 30% is formed from FIG. 29 is the conventional ring-shaped sliding member and disk-shaped sliding member. As compared with Condition 1 of Comparative Example 3 in which both are smooth surfaces, the friction coefficient is small, which is a reduction of about 40%. Furthermore, it can be seen that the friction coefficient tends to decrease when used in combination with the fine groove 235.

  From these results, in the lubricating region where the influence of the viscosity of the lubricating oil is relatively large, due to the reduction of the substantial sliding area and the labyrinth effect caused by the formation of the concave portion 333 and the fine groove 335 provided on the sliding surface, etc. It is considered that the viscous resistance of the lubricating oil was reduced and the friction loss was reduced.

  However, if the substantial sliding area is further reduced by further formation of the concave portion 333 and the fine groove 335, a lubrication state in which the metal contact is the main component will eventually occur, and the friction coefficient will start to increase.

  Therefore, depending on sliding conditions such as load, speed, viscosity of the lubricant (lubricating oil), and the oil properties and supply conditions of the lubricant and lubricating oil, the appropriate maximum shape and size of the recess 333 and the fine groove 335 are appropriate. It is desirable to determine the value.

  Further, in the third embodiment, as in the first and second embodiments, the present invention can be applied to various sliding members of various devices. Degree), operating conditions, supply state of the lubricating oil, and oil properties (viscosity, oil type, etc.), etc., and appropriate specifications of the concave portion 136 and the fine groove 335 may be determined.

  Therefore, in the third embodiment, in the case of the reciprocating compressor 150 shown in FIG. 11 described in the first and second embodiments, the boundary and the mixed lubrication region are the same as in the second embodiment. An effective effect can be expected for any sliding in the region where the sliding members are in contact with each other and the fluid lubrication region (the region where the viscosity of the lubricant and lubricating oil is dominant). .

  That is, the lubrication state of the sliding surface is improved by providing a concave portion 333 or a fine groove 335 having an appropriate opening area ratio corresponding to the operating rotational speed, surface pressure, actual use viscosity, and the like, and surface roughness and depth. In addition, it can be expected that the high efficiency and high reliability of the reciprocating compressor 150 will be realized.

  Also, in the case of the rotary compressor shown in FIG. 12 described in the first and second embodiments, as in the second embodiment, the boundary, the mixed lubrication region (the sliding members are in contact with each other). Effective effects can be expected for any sliding structure in the sliding region) or fluid lubrication region (region where the viscosity of the lubricant is dominant).

  That is, the lubrication state of the sliding surface is improved by providing a concave portion 333 or a fine groove 335 having an appropriate opening area ratio corresponding to the operating rotational speed, surface pressure, actual use viscosity, and the like, and surface roughness and depth. In addition, it can be expected that the rotary compressor 170 is highly efficient and reliable.

  Further, in the case of the scroll type compressor shown in FIG. 13 described in the first and second embodiments, the boundary and the mixed lubrication region (sliding members are in contact with each other) as in the second embodiment. Effective effects can be expected for any sliding structure in the sliding region) or fluid lubrication region (region where the viscosity of the lubricant is dominant).

  That is, the lubrication state of the sliding surface is improved by providing a concave portion 333 or a fine groove 335 having an appropriate opening area ratio corresponding to the operating rotational speed, surface pressure, actual use viscosity, and the like, and surface roughness and depth. In addition, high efficiency and high reliability of the scroll compressor 180 can be expected to be realized.

  According to the present invention, a dimple-like shape is formed in the entire sliding surface of at least one sliding member of the two sliding members arranged so that one slides with respect to the other, or in a certain region of the sliding surface. By providing the recess, the oil sump function can be maintained and friction loss can be reduced, and it can be applied to sliding structures of various devices in various technical fields such as bearing devices and compressors having a sliding structure. Can do.

124 Projection particle 132 Sliding member 136 Recessed portion 138 Sliding surface 150 Reciprocating compressor 170 Rotary type compressor 180 Scroll type compressor 231 Sliding member 232 Sliding surface 233 Recessed portion 235 Fine groove 236 Small recessed portion 241 Mold 242 Convex portion 331 Sliding member 332 Sliding surface 333 Concavity 335 Fine groove 341 Mold 342 Convex

Claims (17)

At least one of the two sliding members arranged so that one slides relative to the other, the entire sliding surface of the sliding member, or a certain region of the sliding surface, the dimple-shaped concave portion and the concave portion The flat portion provided between the two is provided in a mixed manner ,
The opening area ratio, which is the ratio of the total area of the opening of the concave portion occupying the entire sliding surface or a certain area, is in the range of 5 to 20 %,
Furthermore, a lubricant or lubricating oil is interposed between the two sliding members ,
While receiving the load at the flat portion, the sliding surface pressure is dispersed, and the lubricant or the lubricating oil held in the concave portion oozes out to the flat portion, thereby reducing adhesion wear. Sliding member. The sliding member according to claim 1, wherein the opening of the concave portion has a substantially circular shape when viewed from the front and has a substantially arc-shaped cross section. The sliding member according to claim 1 or 2, wherein a surface roughness Ra of the sliding surface of the sliding member is 0.3 or less. The sliding member according to any one of claims 1 to 3, wherein a depth of the concave portion is in a range of 0.5 to 3.0 µm. The sliding according to any one of claims 1 to 4, wherein the two sliding members are made of materials having different hardnesses, and the concave portion is provided on a surface of the sliding member made of the material having low hardness. Element. The sliding according to any one of claims 1 to 4, wherein the two sliding members are made of materials having different hardnesses, and the concave portion is provided on a surface of the sliding member formed of the material having high hardness. Element. The sliding member as described in any one of Claim 1 to 6 which provided the micro recessed part of an area smaller than the said recessed part between the said recessed parts formed in the sliding surface of the said sliding member. The sliding member according to claim 7, wherein a depth of the minute recess is formed shallower than a depth of the recess. The sliding member according to claim 7, wherein a depth of the minute recess is formed deeper than a depth of the recess. The sliding member according to any one of claims 7 to 10, wherein the minute recess is a minute groove. The sliding member according to claim 10, wherein an extending direction of at least a part of the fine grooves in the fine grooves is parallel to a sliding direction of the sliding member. The sliding member according to claim 10 or 11, wherein an extending direction of at least a part of the fine grooves in the fine groove intersects with a sliding direction of the sliding member at a predetermined angle. The apparatus which comprised the structure which has a structure which has a sliding relationship in the apparatus which comprised the structure in which several components are in a sliding relationship, The apparatus made into the sliding member as described in any one of Claim 1 to 12. The device according to claim 13, wherein the device is a compressor. 10. A slide that forms a dimple-like recess according to claim 1 by projecting projection particles having a substantially spherical shape and an average radius of 3 to 200 μm onto the surface of the sliding member. A surface treatment method for a moving member. By pressing a mold having a substantially arc-shaped convex portion on one surface so as to be regularly or irregularly arranged, on the entire sliding surface of the sliding member or an arbitrary region, Item 13. A surface treatment method for a sliding member that forms the dimple-like recess according to any one of Items 1 to 12. The surface treatment method for a sliding member according to claim 16, wherein a raised portion on the peripheral surface of the recessed portion due to the formation of the recessed portion is a sliding surface, and a space between the raised portions is a fine groove.