JP6534066B2 - piston ring - Google Patents

Description

  The present invention relates to the improvement of piston rings used to maintain the tightness of piston sliding parts such as reciprocating oil free compressors.

FIGS. 14A and 14B are side views of conventional general piston rings 200a and 200b. The piston rings 200a and 200b have a flat ring shape, and have a joint 201 perpendicular to the plane or a joint 202 at an oblique angle to the plane for mounting on the piston. However, as the wear of these piston rings 200a and 200b progresses, the outer edges of the piston rings are scraped and the outer diameters of the piston rings 200a and 200b decrease, so the circumferential distance between the joint 201 and 202 increases. As a result, the piston ring opens, the gap in the joint increases, and the air tightness decreases. For this reason, as shown in FIGS. 14-17, various piston rings devised so that airtightness may not fall even if wear progresses are proposed, and one part is put to practical use.

  The conventional piston ring 100a shown in FIG. 15A has a simple step-like abutment 111 opposed in the thickness direction, and the piston ring 100b shown in FIG. 15B is locked in the thickness direction. It has a step-like abutment 112. In these piston rings 100a and 100b, the area of the contact surface of the overlapping portion in the circumferential direction of the joint is increased by steps to reduce the leakage due to wear, but the outer diameter is reduced due to the wear of the piston rings 100a and 100b. When the ring is expanded and the gap in the joint is further expanded, there is a disadvantage that the gas can not be prevented from leaking. The piston ring 100a having the step-like abutment shown in FIG. 15A is described, for example, in FIG. 7 of Patent Document 1.

The conventional piston ring 100 c shown in FIG.
The ring segments 100c1 and 100c2 are in the form of multiple layers of c1 and 100c2, and right angle entrances 113A and 113B are formed at different positions in the circumferential direction. One ring piece 100c2 is provided with a recess 113AR on the outer periphery of a portion having a right angled joint 113B, and the other ring piece 100C1 is provided with a protrusion 100BP fitted to the recess 113AR of the ring piece 100C2.

  The conventional piston ring 100d shown in FIG. 17A is not a multilayer type but an integral type, but has stepped abutments 114 opposed in the thickness direction and the radial direction. In the joint 114, the upper half 114RA and the lower half 114RB in the thickness direction extend in the circumferential direction, and overlap each other in the thickness direction. However, as shown in FIG. 16B, the lower half portion 114RB is formed only on the outer peripheral side portion of the ring.

  The piston rings 100c and 100d described in FIGS. 16 and 17 both have less leakage at the time of wear of the piston ring as compared with the piston ring having the step-like joint described in FIG. In FIG. 16 and FIG. 17, (B) shows the state before abrasion, and (C) shows the state after abrasion. When the outer periphery of the ring is worn down due to the wear of the piston ring 100c, a leak occurs when the protrusion 100BP of the ring piece 100B reaches the gap between the piston P and the cylinder C in the piston ring 100c shown in FIG. Further, the lower half 114RB of the piston ring 100d in FIG. 17 is abraded to reduce the outer diameter, and the portion between the outer diameter and the inner diameter is thinned so that the outer peripheral surface of the piston P and the inner peripheral surface of the cylinder C are reduced. The thin lower half 114RB bites into the gap between the two and loses air tightness and leads to the burnout of the machine.

  The piston ring 200c shown in FIG. 18 has an abutment 216 with the one end 216T at the upper half and the other end 216D at the lower half so as to overlap with each other. A half portion of the ring portion is formed radially adjacent to a circumferential half portion of the end portion 216D. A piston ring 200c of this form is described in FIG. 3 of Patent Document 2. This piston ring has a drawback that the air tightness at the time of wear is largely deteriorated compared to the piston rings of FIGS. 16 to 17, and the performance can not be prevented from being deteriorated.

  When any of the piston rings 100c and 100d in FIG. 16 and FIG. 17 is worn away, it is no longer resistant to use and has a short life.

  FIG. 19A shows a piston ring 200d described in Patent Document 3. As shown in FIG. In this piston ring 200d, a groove 201 is provided at a radially inner portion of the lower side surface, and as shown in FIG. 19 (B), when the ring is worn, the piston P and the piston P are inserted via the groove 201. The upper portion and the lower portion of the piston ring 200d in the gap with the cylinder C are in communication with each other. As a result, the compressed gas leaks due to the communication between the upper part and the lower part due to wear. Then, it is found that the wear has reached a certain amount by leaking the gas and reducing the performance. This prevents the piston ring 200d from biting into the gap between the piston and the cylinder, thereby preventing an accident due to wear. However, although this prior art can prevent wear accident, it does not achieve prolongation of the life of the piston ring.

JP 2008-88842 A JP, 2013-44272, A Japanese Patent Application Laid-Open No. 9-32922

  The object of the present invention is to provide a long-lasting, self-lubricating piston ring which can maintain the airtightness for a long time while ensuring the airtightness to be used, and can prevent the wear accident. It is in.

The first self-lubricating piston ring according to the present invention is
It is disposed in a groove provided on the outer peripheral surface of the piston so as to be interposed between the cylinder and a piston reciprocating in the cylinder, and there is a gap between the bottom and the side surface of the groove of the piston The self-lubricating piston ring airtightly divides two spaces in the cylinder by applying a stress toward the inner surface of the cylinder by a pressure medium acting on the gap.
It has a ring plate shape, and has a first joint which is formed so as to be mutually airtight and airtight in a radial direction in a part of the circumferential direction, and in this first joint, the opposing part is in the circumferential direction A first ring member that can move relative to the first ring member and the circumferentially expanding distance is limited to a predetermined value or less;
It has a ring plate shape, and has a second joint that is formed so as to be mutually airtight and airtight in the radial direction in a part of the circumferential direction, and in this second joint, the opposing part is in the circumferential direction A second ring member movable relative to the
Have
The first joint and the second joint may be overlapped so as to be at different positions in the ring circumferential direction.

In this self-lubricating piston ring, for example,
Furthermore, it has a third ring member which has a ring plate shape and is divided in a part in the circumferential direction and in which a third joint having surfaces facing in the circumferential direction is formed,
The third ring member may be superimposed on the second ring member such that the third joint is at a position different from the second joint in the circumferential direction of the ring.

Furthermore, in this self-lubricating piston ring, for example
It has one of the first ring members and two of the second ring members, a first joint of the first ring members, and two second of the two ring members. The first and second ring members are overlapped such that the joint between the two is at different positions in the ring circumferential direction.

The second self-lubricating piston ring according to the present invention is
It is disposed in a groove provided on the outer peripheral surface of the piston so as to be interposed between the cylinder and a piston reciprocating in the cylinder, and there is a gap between the bottom and the side surface of the groove of the piston The self-lubricating piston ring airtightly divides two spaces in the cylinder by applying a stress toward the inner surface of the cylinder by a pressure medium acting on the gap.
It has a ring plate shape, and has a first joint which is formed so as to be mutually airtight and airtight in a radial direction in a part of the circumferential direction, and in this first joint, the opposing part is in the circumferential direction , And has three first ring members whose distance extending in the circumferential direction is limited to a predetermined value or less,
Three first ring members are overlapped so that the three first abutments are at different positions in the ring circumferential direction.

The third self-lubricating piston ring according to the present invention is
It is disposed in a groove provided on the outer peripheral surface of the piston so as to be interposed between the cylinder and a piston reciprocating in the cylinder, and there is a gap between the bottom and the side surface of the groove of the piston The self-lubricating piston ring airtightly divides two spaces in the cylinder by applying a stress toward the inner surface of the cylinder by a pressure medium acting on the gap.
It has a ring plate shape, and has a second joint that is formed so as to be mutually airtight and airtight in the radial direction in a part of the circumferential direction, and in this second joint, the opposing part is in the circumferential direction A second ring member movable relative to the
A third ring member which has a ring plate shape and is divided in a part in the circumferential direction and in which a third joint having surfaces facing in the circumferential direction is formed;
Have
The second joint and the third joint may be overlapped so as to be at different positions in the ring circumferential direction.

The fourth self-lubricating piston ring according to the present invention is
It is disposed in a groove provided on the outer peripheral surface of the piston so as to be interposed between the cylinder and a piston reciprocating in the cylinder, and there is a gap between the bottom and the side surface of the groove of the piston The self-lubricating piston ring airtightly divides two spaces in the cylinder by applying a stress toward the inner surface of the cylinder by a pressure medium acting on the gap.
A fourth ring member continuous in the circumferential direction, having a ring plate shape and having no abutment;
It has a ring plate shape, and has a second joint that is formed so as to be mutually airtight and airtight in the radial direction in a part of the circumferential direction, and in this second joint, the opposing part is in the circumferential direction A second ring member movable relative to the
It is characterized by having.

In this self-lubricating piston ring, for example,
Furthermore, it has a third ring member which has a ring plate shape and is divided in a part in the circumferential direction and in which a third joint having surfaces facing in the circumferential direction is formed,
The second joint and the third joint may be overlapped so as to be at different positions in the ring circumferential direction.

The fifth self-lubricating piston ring according to the present invention is
It is disposed in a groove provided on the outer peripheral surface of the piston so as to be interposed between the cylinder and a piston reciprocating in the cylinder, and there is a gap between the bottom and the side surface of the groove of the piston The self-lubricating piston ring airtightly divides two spaces in the cylinder by applying a stress toward the inner surface of the cylinder by a pressure medium acting on the gap.
It has a ring plate shape, and has a first joint which is formed so as to be mutually airtight and airtight in a radial direction in a part of the circumferential direction, and in this first joint, the opposing part is in the circumferential direction And four or more first ring members whose distance in the circumferential direction is limited to a predetermined value or less.
It is characterized in that four or more first ring members are stacked so that four or more of the first abutments are at different positions in the ring circumferential direction.

  According to the first invention of the present application (claim 1), when the circumferential surface of the first ring member wears away due to sliding with respect to the cylinder, the portions facing each other at the first joint are circumferentially relative to each other. As a result, the first ring member opens in the circumferential direction, and the circumferential surface always tries to slide on the inner surface of the cylinder. Thereby, the space in the cylinder is airtightly partitioned into two spaces by the first ring member even if the circumferential surface of the first ring member is worn out. The same is true for the second ring member. On the other hand, in the first ring member, since the degree of opening of the ring at the first joint is limited to a predetermined value or less, the peripheral surface becomes a cylinder after the peripheral surface becomes a predetermined diameter after being worn to a certain extent. It will not slide out and wear will stop. However, in the second ring member, the degree of opening of the ring in the circumferential direction is not limited, so when wear on the circumferential surface progresses, the opposing portion moves in the circumferential direction at the second joint and the ring Continues to expand. As a result, the circumferential surface of the second ring member always slides on the inner surface of the cylinder, and wear of the circumferential surface does not stop, and the radial length of the second ring member continues to decrease. However, since the second ring member is superimposed on the first ring member, and as described above, the first ring member is not worn any more when it is worn to a certain extent, so the second ring member is Even if it becomes smaller due to wear, it is not blocked by the first ring member and does not enter the gap between the piston and the cylinder. On the other hand, since the first ring member does not slide on the inner surface of the cylinder when the wear progresses to a certain extent, the air tightness between the two is reduced, but the second ring member maintains the air tightness with the cylinder inner surface. Therefore, as a self-lubricating piston ring, the air tightness is maintained. Therefore, according to the present invention, it is possible to achieve air tightness by the self-lubricating piston ring and prolongation of its life.

  According to the second invention of the present application (claim 4), since the three first ring members are used, the sealing performance is reduced when the stopper function works, but the ring is not worn more than a certain degree, so the ring is over It has a long life. When the function works, the applied stress disappears and the sealing performance is reduced, but it works as a labyrinth seal that seals with an extremely small gap, and the sealing performance is not lost. Labyrinth seals that seal with gaps are already known.

Further, according to the third invention of the present application (claim 5), by using the second ring member and the third ring member to increase the wear margin of the second ring member (see FIG. 16) The ring life can be significantly extended.

Furthermore, according to the fourth invention of the present application (claim 6), since the fourth ring member and the second ring member are used, the ring plate-like fourth ring member having no joint is, in principle, It does not wear unless it moves in the radial direction. Similar to the first ring member after wear, the second ring member is inserted between the inner surface of the cylinder and the outer surface of the piston even if the second ring member wears and becomes smaller because the wear does not progress. Can be blocked by the fourth ring member. Also, the sealability can be maintained by the second ring member.

FIG. 1 shows a vertical cross-sectional view of a reciprocating oilless air compressor. It is a vertical sectional view showing a piston ring concerning a 1st embodiment of the present invention, and the figure (A) shows a state immediately after piston installation, and the figure (B) shows a state where a piston ring was worn, respectively. Similarly, three different types of ring members used in the piston ring of the first embodiment are respectively shown in plan views in FIGS. (A) to (C), and the laminated state of these ring members is shown in side view in FIG. FIG. It is a vertical sectional view of a piston and a cylinder equipped with a piston ring of a preferred embodiment (1) having a joint of the first embodiment in the same manner. (A) shows the state immediately after the piston is installed, and (B) shows the piston The respective rings are shown as worn. FIG. 6A is a view showing the main part of the joint portion of the piston ring of the first embodiment, and FIG. 6A shows a state immediately after mounting corresponding to FIG. 2A, and FIG. Indicates the status. The figure (C) is the figure which expanded the principal part. It is a figure which shows the state of the gap and clearance gap by progress of wear of a 1st ring member. It is a vertical sectional view showing a piston ring concerning a 2nd embodiment of the present invention, and the figure (A) shows a state immediately after piston installation, and the figure (B) shows a state where a piston ring was worn, respectively. Similarly, three different types of ring members used in the piston ring of the second embodiment are respectively shown in plan views in FIGS. (A) to (C), and the layered state of these ring members is shown in side view in FIG. FIG. Similarly, it is a vertical sectional view of a piston and a cylinder on which the piston ring of the second embodiment is mounted, wherein (A) shows a state immediately after the piston is mounted, and (B) shows a worn state of the piston ring. It is a perspective view which shows the state which laminated | stacked the ring member of 1st Embodiment of this invention. It is a perspective view which shows the state which laminated | stacked the ring member of the piston ring of 2nd Embodiment of this invention. It is a perspective view which shows the state which laminated | stacked the piston ring of 3rd Embodiment. It is a perspective view which shows the state which laminated | stacked the piston ring of 4th Embodiment. FIG. 1 is a side view of the simplest prior art piston ring with right or beveled abutments. The figure shows two different piston rings according to the prior art having opposite joints in the thickness direction, the figures (A) and (B) respectively show a plan view thereof, and the figures (A ') and (B') respectively show A) It is a side view of the piston ring of (B). The piston ring by the prior art which has the abutment opposite to the thickness direction and radial direction is shown, The figure (A) is the perspective view, the figure (B) (C) is the wear before and after wear of this piston ring. It is sectional drawing of a state. The piston ring by the prior art which has the abutment opposite to the thickness direction and radial direction is shown, The figure (A) is the perspective view, the figure (B) (C) is the wear before and after wear of this piston ring. It is sectional drawing of a state. FIG. 7 is a perspective view of another different prior art piston ring with abutments facing in thickness and radial directions; It is sectional drawing of the state before wear of the piston ring of patent document 3, and after wear.

  Hereinafter, embodiments of the present invention will be described. FIG. 1 is a longitudinal sectional view of a reciprocating oilless air compressor using a self-lubricating piston ring of the present embodiment, and FIGS. 2 to 5 are self-lubricating properties of a first embodiment of the present invention. FIG. 2 is a view showing a piston ring, and FIG. 2 is a longitudinal sectional view showing a piston and a cylinder to which the self-lubricating piston ring is attached. In the compressor shown in FIG. 1, the cylinder (C) is disposed above the crank chamber (CC), and the cylinder of the bottom of the crank chamber (CC) and the valve plate (VP) of the valve cover (VC) (C) and the crank chamber (CC) etc. are sealed. In the crank chamber (CC), a crank is disposed rotatably around a crankshaft (CS), and in a cylinder (C), a piston (P) is disposed to be able to move up and down. The connecting rod (CR) has its connecting rod large end (CRL) rotatably connected to the periphery of the crankshaft (CS), and its connecting rod small end (CRS) connects to the piston (P) with the piston shaft (PS) It is connected rotatably via). Thus, when the crankshaft (CS) rotates, the driving force of the rotation is transmitted to the piston (P) via the connecting rod (CR), and the piston (P) is moved up and down. Also, when the piston (P) descends, the volume of the compression chamber (PC) expands and gas is drawn into the compression chamber (PC) through the suction valve (IL). At the bottom dead center of the piston (P), the volume of the compression chamber (PC) is maximum. When the piston (P) rises, the volume of the compression chamber (PC) decreases, and when the pressure in the compression chamber (PC) reaches the discharge pressure, the compressed gas is discharged through the discharge valve (DV), The compressed gas is discharged until (P) reaches the top dead center. The self-lubricating piston ring (PR) of the present embodiment is disposed on the outer peripheral surface near the upper end portion of the piston (P), and the cylindrical rider ring (RR) is disposed on the lower piston outer peripheral surface. It is arranged. These self-lubricating piston rings (PR) ensure airtightness between the outer peripheral surface of the piston (P) and the inner peripheral surface of the cylinder (C).

  In the first embodiment, as shown in FIG. 2, the self-lubricating piston ring (PR) is a piston ring 10 including a first ring member 20, a second ring member 30, and a fourth ring member 40. To be realized. FIGS. 3A to 3C are front views showing three-layer ring members 20, 30, 40 of the piston ring 10 of the first embodiment, respectively. Each ring member 20, 30, 40 has a different shape of joint 22, 32, 42. The ring members 20, 30, 40 are mutually stacked in this order as shown in FIG. 3D, but at that time, the positions of the abutments 22, 32, 42 of the ring members 20, 30, 40 are As shown in FIGS. 3A to 3C, the abutment 22 and the abutment 32 are located on the opposite side in the circumferential direction, and the abutment 22 and the abutment 42 are located at the same position in the circumferential direction. As a result, the gap in the joint 22 of the first ring member 20 is blocked in the piston movement direction in the portion where the joint 32 of the second ring member 30 does not exist, and the gap in the joint 32 of the second ring member 30 is The piston ring 10 is structured such that there is no gap in the piston movement direction, because the piston ring 10 is blocked in the piston movement direction at the portion where the joint 42 of the three ring member 40 does not exist, inside the compression chamber (PC) in the cylinder (C). The pressure is effectively sealed.

  The joint 22 of the first ring member 20 of the first embodiment has peripheral pieces 22A and 22B engaged with each other in the radial direction of the first ring member 20, and these opposed peripheral pieces 22A and 22B On the opposing surface of the second embodiment, concavo-convex (substantially trapezoidal) tooth portions 24A and 24B are formed to engage with each other. Side pieces 25A and 25B on the base end side of the peripheral piece 22A and the peripheral piece 22B in the tooth shape portion 24A and the tooth shape portion 24B are formed to be inclined, and the side pieces 24AS and 24BS on the distal end side (FIG. 5C) Reference) is formed vertically. The distance between the side pieces 24AS and 24BS is a distance at which the first ring member 20 can open in the circumferential direction by the gap 24g (see FIG. 5A). In this case, the circumferential length of the first ring member 20 is shortest when the side pieces 25A and 25B are in contact with each other. At this time, the distance between the vertical side pieces 24AS and 24BS is the largest gap 24g. This is the maximum distance in which the one ring member 20 can expand in the circumferential direction, that is, the maximum distance in which the circumferential pieces 22A and 22B can be relatively moved in the circumferential direction. Therefore, the vertical side pieces 24AS, 24BS function as the stopper means 26 which makes the spread of the first ring member 20 equal to or less than the maximum distance. When the peripheral pieces 22A and 22B move relatively in the ring expanding direction by the maximum gap 24g from the state in which the side pieces 25A and 25B are in contact, the vertical side pieces 24AS and 24BS abut each other (FIG. 5) (See B)), no more ring members open.

The vertical side pieces 24AS, 24BS are formed on circumferentially opposed walls of these adjacent teeth 24A, 24B so as to have a radially extending surface via a gap 24g. Accordingly, when wear due to sliding with the cylinder C occurs, the first ring member 20 radially expands until the tooth shoulders 24AS and 24BS butt each other so that the gap 24g disappears. Since there is no radial expansion, there is no further wear. The progress of wear will be described based on FIG. When mounting the ring, the ring dimensions are determined so that the gap is maximum and the gap is minimum (FIG. 6 (A)). Next, when the operation is performed and the ring outer periphery wears, the ring member 20 is pushed outward by the pressure in the compression chamber (PC) according to the amount of wear. Then, the gap 24g becomes smaller and the gap 24h increases according to the pushed-out amount. (FIG. 6 (A)). As further wear progresses, the gap 24g finally becomes 0, and when the vertical side pieces 24AS and 24BS abut, the gap 24h becomes maximum. The ring member 20 does not wear any more.

  The second ring member 30 is, as shown in FIG. 3B, a position where the joint 32 is different from the joint 22 of the first ring member 20 in the circumferential direction, preferably the joint 22 of the first ring member 20. Are stacked with respect to the first ring member 20 so as to be shifted by 180 °. When the fourth ring member 70 (see FIG. 8) having no joint is used instead of the first ring member 20, the circumferential position of the fourth ring member 70 and the second ring member 30 does not cause a problem. .

  As shown in FIGS. 2 (B) and 3 (B), the joint 32 of the second ring member 30 is composed of diametrically opposed toothless circumferential pieces 32A, 32B. Therefore, in the second ring member 30, a portion not having the joint 32 is to be laminated on the joint 22 of the first ring member 20, and the leak from the joint 22 of the first ring member 20 is complementarily It has a function to prevent. Further, since the joint 32 of the second ring member 30 is stacked in a portion where the joint 22 of the first ring member 20 does not exist, the second ring member 30 may be worn out and radially expanded. Even if there is a gap between the cylinder C and the piston P at a portion of the first ring member 20 where there is no joint, the thin portion of the second ring member 30 does not bite into the gap G.

  As shown in FIG. 3C, the third ring member 40 is stacked on the second ring member 30 so that the joint 42 is at a position corresponding to the joint 32 of the second ring member 30. The abutment 42 is composed of circumferentially opposed circumferential pieces via a gap.

  Although the first ring member 20, the second ring member 30, and the third ring member 40 are stacked in this order as shown in FIG. 3D, at this time, the joint 22 and the joint 32 are identical. The positions in the circumferential direction of the respective members are determined so that the joint 32 and the joint 42 are not at the same position. Thus, by overlapping the first ring member 20, the second ring member 30, and the third ring member 40, the gas passes through the piston ring via the joint ports 22, 32, 42, and the piston ring Airtightness is prevented from being broken.

Next, the operation of the first embodiment of the present invention will be described. The piston ring 10 of the embodiment of FIGS. 2 and 3 is a second and third ring on the first ring member 20 in the groove PE of the piston P, as shown in FIGS. 2 and 3D. The members 30, 40 are sequentially stacked and mounted. When the piston ring 10 mounted in the piston P in this stacked state performs a piston movement in the cylinder, each ring member 20, 30, 40 of the piston ring 10 has a pressure as shown in FIG. It slides on the inner circumferential surface of the cylinder C while being received. The outer diameter of each ring member 20, 30, 40 slides with the inner periphery of the cylinder by this sliding, and the outer periphery of the ring wears and becomes thinner as shown in FIG. 4 (B). As can be seen by comparison of FIG. 4 (B) and FIG. 5 (A) with FIG. 5 (B), the first ring member 20 is used until the gap (wear allowance) 24g of the stopper means 26 of the joint 22 disappears. It radially expands, but when gap 24g disappears and tooth shoulders 24AS and 24BS contact, there is no further expansion. Therefore, as shown in FIG. 4 (B) and FIG. 5 (B), the first ring member 20 is not worn away after the radial expansion is stopped.

  In the case of the first ring member 20 having a joint, in the illustrated embodiment, the first ring member 20, the second ring member 30, and the third ring member 40 of FIGS. 3A to 3C are stacked. The piston ring 10 of the present invention is formed of a laminate of two or more ring members, at least one of which is the first ring member 20 and at least one other ring member. One ring member can be any ring member having an abutment at a position different from the abutment 22 of the first ring member 20 in the circumferential direction. In this way, the first ring member 20 can be prevented from further wear by leaving the gap enough to withstand use by the stopper means 26 of the joint 22 of the first ring member 20, and the other The portion of the at least one ring member not having the joint can effectively prevent airtight leakage due to the remaining gap of the joint 22 of the first ring member 20.

  Next, a second embodiment of the present invention will be described with reference to FIGS. 7 to 9. This embodiment corresponds to claim 7. The piston ring 60 of the second embodiment is disposed in the upper end recess PE of the piston P, as shown in FIGS. 7 and 8D, and the second ring is placed on the fourth ring member 70. The member and the third ring member 40 are sequentially stacked and mounted. Since the fourth ring member 70 has no joint, the piston P needs to be divided in order to mount the fourth ring member 70. When the piston ring 60 mounted in the piston P in this stacked state performs a piston movement in the cylinder, each ring member 70, 30, 40 of the piston ring 60 has a pressure as shown in FIG. It slides on the inner circumferential surface of the cylinder C while being received. However, the ring member 70 having no joint does not expand even if it receives pressure from the inside of the ring because there is no joint, and does not slide on the inner peripheral surface of the cylinder C. Alternatively, it is possible to select a dimension that does not contact the cylinder inner circumference in anticipation of expansion even if it is expanded by pressure. Therefore, even if the second ring member 30 and the third ring member 40 may be worn away and may be radially expanded, the second ring member 30 has a thin portion due to the first ring member without an abutment. There is no bite into the gap G.

  On the other hand, in the case of using the first ring member 20 having a joint instead of the fourth ring member 70, even if a gap is generated in the joint 22 of the first ring member 20, the second ring member 30 It has a function of closing the gap to prevent airtight leakage from the joint of the first ring member 20. Similarly, the third ring member 40 exerts the same effect on the second ring member 30 as well.

  In the case of the fourth ring member 70 having no joint, the gap in the joint of the second ring member 30 is closed by laminating the third ring member 40, and the fourth ring member 70 has no joint, so the fourth Airtight leakage does not occur from the inside of the ring member 70 of FIG.

  In the case of the first ring member 20 having a joint, the joint of the first ring 20 is closed by the jointless portion of the second ring member 30, and the joint of the second ring member 30 is the third ring While it functions to prevent leakage in the thickness direction by being blocked by the part without joint of the member 40, leakage in the radial direction is sealed by closing by the first ring member 20 and the second ring member 30 itself. It prevents leakage.

  In the case of the fourth ring member 70 without a gap, the second ring member 30 and the third ring member 40 interact to prevent leakage in the radial and thickness directions, and the fourth ring The member 70 prevents airtight leakage from the inside of the ring.

  In the case of the first ring member 20 having a gap, the second ring member 30 and the third ring member 40 are worn away due to wear as shown in FIG. The first ring member 20 prevents biting into the gap G between the cylinder C and the piston P, and biting of a thin portion does not inhibit the slidability of the piston P.

  Also in the case of the fourth ring member 70 without a gap, the second ring member 30 and the third ring member 40 are worn away due to wear as shown in FIG. The fourth ring member 70 prevents biting into the gap G between the cylinder C and the piston P, and biting of a thin portion does not inhibit the slidability of the piston P.

  In the case of the fourth ring member 70 without a gap, in the illustrated embodiment, the fourth ring member 70, the second ring member 30, and the third ring member 40 of FIGS. 8A to 8C are stacked. Piston ring 60, but the piston ring 60 of the present invention is composed of a laminate of two or more ring members, at least one of which is the fourth ring member 70 and at least one other ring member. The one ring member may have any position in the circumferential direction of the joint.

  Next, a third embodiment of the present invention will be described with reference to FIG. In the third embodiment, the first ring member 20, the second ring member 30, and the fourth ring member 40 are stacked.

  The embodiment shown in FIG. 11 shows a fourth embodiment of the present invention. In the fourth embodiment, the second ring member 30, the third ring member 40, and the fourth ring member 70 are stacked.

  The fifth embodiment shown in FIG. 12 corresponds to the fourth aspect, and uses three first ring members 20. Since wear does not progress more than a certain amount, each ring member can be made to have an extremely long service life although the sealability may be slightly reduced. Therefore, it should be used for applications requiring an extremely long life even if the sealability is slightly reduced. Can.

  The sixth embodiment shown in FIG. 13 corresponds to claim 5, and uses a second ring member 30 and a third ring member 40. Even if the wear of the second ring member 30 progresses, the sealability is slightly reduced. Therefore, the life can be greatly extended by increasing the wear allowance. However, since there is no first ring member 20, an ultra-long life can not be achieved.

According to the invention, in the case of the first ring having an abutment, any additional ring having an abutment at a circumferential position different from the abutment of this first ring member on the first ring member having the abutment including the stopper means In both of the first ring members in which the ring members are laminated and do not have a joint, the life can be extended, and troubles can be avoided when the ring members are worn, and by the additional ring members Since the airtightness can be improved, industrial applicability is improved.

If the operation time until the gap 24g becomes 0 is provided, for example, 8000 hours by providing the stopper means 26, the life equal to or longer than that of the conventional product can be maintained, and the super long term is maintained while the performance is slightly reduced. Industrial use is improved because it is possible to

B bolt C cylinder CC crankcase CR connecting rod CRL connecting rod large end CRS connecting rod small end CS crankshaft DV discharge port IL inlet P piston PC compression chamber PE piston ring groove PP piston plate PR self lubricating piston ring RR self lubricating Rider ring SB slide bearing
VC Valve cover VP Valve plate G Gap between piston P and cylinder C
10 Cylinder inner wall 20, 30, 40, 70 Ring member 22, 32, 42 Joint 22A, 22B Peripheral piece 24A, 24B of joint 22 substantially trapezoidal teeth 24AS, 24BS Tooth shoulder 24g Gap 24h Clearance 25A, 25B Recess 32A, 32B Gaps 42A and 42B in the gap 32g 30 of the gap 32 of the gap 32 the gap of the gap 42

Claims (3)

In a compressor including a cylinder and a piston reciprocating in the cylinder, an arrangement structure of a piston ring for sealing an outer periphery of the piston,
The piston rings are stacked in at least three stages in grooves provided on the outer peripheral surface of the piston, and among the three stages of piston rings, one of the three stages has no joint.
A ring member having a ring plate shape at a position farthest from the tip end position of the piston and having no joint, and a circumferentially continuous ring member without joint;
It is one surface of the ring member without the abutment , and is disposed closer to the tip of the piston than the ring member without the abutment , and faces each other with airtightness in a radial direction in a part of the circumferential direction a ring member having a second abutment formed in this second abutment, and a second ring member opposite portions can move relative to the circumferential direction,
A surface of the second ring member, which is disposed closer to the tip of the piston than the second ring member, is divided at a part in the circumferential direction, and has a circumferentially opposite surface. Having a third ring member in which three abutments are formed;
An arrangement structure of a piston ring , wherein the second joint and the third joint are overlapped so as to be at different positions in the ring circumferential direction . The gap between the outer periphery of the non-joined ring member and the inner periphery of the cylinder is larger than the gap between the outer periphery of the second and third ring members with the abutment and the inner periphery of the cylinder The piston ring arrangement structure according to claim 1, characterized in that The ring member having the second joint has a joint portion along the circumferential direction of the ring member, and a joint portion orthogonal to the joint, and the ring member having the third joint has the direct joint The piston ring arrangement structure according to claim 1, comprising only an abutment portion .

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