JP4333476B2 - Connecting structure of connecting rod and piston of engine - Google Patents

Description

The present invention, connection structure for connecting the connecting rod and the piston in the engine, particularly to a connection structure for the purpose of reducing the weight of the piston mass.

Conventionally, an engine mounted on a vehicle or the like, particularly a four-cylinder engine, is generally provided with a balance shaft in order to eliminate vibration and noise caused by a secondary inertia force. However, in recent years, there is an increasing demand for reducing the balance shaft in order to reduce the weight and cost of the engine.

By reducing the secondary inertia force, it is possible to reduce the balance shaft, but the piston mass contributing to this secondary inertia force has a small number of cylinders such as four cylinders and a large displacement (for example, In an engine with a displacement of 2200cc or more), it must be heavy, and in a normal engine, the piston pin is located above the piston ring (on the piston crown side) because the piston pin is inserted from the side of the piston. can not be set to, may not be able to reduce the dimension between the piston crown and the piston pin, the remains of the current structures, the use of light metal such as aluminum, could not be effectively lighter It was.

Therefore, in order to reduce the weight of the piston, it is conceivable to eliminate the piston pin that connects the piston and the connecting rod, and further to shorten the total length of the piston by setting the connecting position as high as possible.

As a structure that eliminates the piston pin, a spherical convex portion is formed on the lower surface of the crown portion of the piston, a spherical concave portion is formed at the upper end of the connecting rod so as to correspond to the spherical convex portion, and the spherical convex portion and the spherical concave portion are slid. be to moving contact, the structure for coupling the piston and the connecting rod can be considered.

There exists following patent document 1 as what employ | adopted such a connection structure.
Patent Document 1, in a large diesel engine compression ratio and the combustion pressure, to lower the surface pressure of the sliding surface between the piston and the connecting rod is intended to improve the durability, directly, as in this case weight Although not intended to make it easier, a spherical convex portion is formed on the lower surface of the crown portion, and a bowl-shaped saucer having a spherical concave portion that slides on the spherical convex portion is provided on the connecting rod, and the saucer is screwed onto the skirt portion. by maintaining the sliding position in a total fixed holding cylinder or the like, and connects the piston and the connecting rod.

Thus, by connecting the piston and the connecting rod by sliding abutment of the spherical convex portion and the spherical concave portion, the piston pin will not be required, it is also possible that the connecting position is set to the upper side.

Japanese Patent No. 2581326

However, given the weight of the piston mass, it can not be in the structure of Patent Document 1 described above achieve charge amount of weight. This is because a holding cylinder or the like that is screwed and fixed to the skirt portion must be provided separately, and the wall thickness must be increased in order to ensure the rigidity of the skirt portion.

  That is, when a holding cylinder or the like that is screwed and fixed to the skirt portion as in Patent Document 1, it is necessary to separately provide a member that is heavier than the piston pin and approximately the same diameter as the piston. As a result, the piston pin The merit of trying to reduce the weight without using is lost.

  Therefore, in order to reduce the weight, a support member for the tray that is as compact as possible is required instead of the holding cylinder or the like.

However, and support members of the pan is because it is a member repeatedly subjected to combustion pressure in the cylinder da, also necessary to consider not to damage.

Accordingly, the present invention is a connecting structure for connecting the connecting rod and the piston in the engine, in order to pistons lightweight, connecting the connecting rod and the piston in sliding abutment of the spherical convex portion and the spherical concave portion, the sliding The support member that supports the saucer used for dynamic contact can be made compact and light in weight while not easily damaged , and a connecting rod is inserted into the saucer support member. By forming a rotation restricting means for restricting the movement of the piston in the rotation direction, the elongated hole-shaped insertion hole is formed, and the plane portion formed on the side surface of the insertion hole and the connecting rod side is used to The rotation restricting means for restricting the movement is composed of the side surface of the insertion hole of the tray support member and the flat portion formed on the connecting rod side. For this reason, no separate member is required for restricting the rotation of the piston, and this rotation restricting position can also be performed at a position close to the rotation center of the piston. An object of the present invention is to provide an engine connecting rod and piston coupling structure capable of regulating the rotation of the piston .

The connecting rod and piston connecting structure of the engine of the present invention is a connecting structure of the connecting rod and piston of the engine that connects the connecting rod and the piston, and is formed on the lower surface of the crown portion of the piston and protrudes downward from the spherical surface. And a bowl-shaped saucer portion provided at the upper end of the connecting rod and having a spherical recess that is in sliding contact with the spherical projection, and the rod-shaped saucer portion is slidably supported from below, and the thrust direction of the piston and has a fastening section which extends only in the minor thrust direction, and a pan supporting member to be fastened to the crown lower surface in the fastening portion, said pan supporting member, a long hole shape for inserting the connecting rod Rotation that regulates the movement of the piston in the rotational direction by forming a through hole and a flat part formed on the side of the through hole and the connecting rod side. It is obtained by configuring the control means.

According to the above configuration, the piston and the connecting rod are slidably brought into contact with each other by the spherical convex portion formed on the lower surface of the crown portion of the piston and the bowl-shaped saucer portion having the spherical concave portion at the upper end of the connecting rod , thereby supporting the tray. by fastening fixing the bowl-shaped pan portion to the piston by a member, coupling the piston and the connecting rod. Then, it performed by fastening portion for extending the engagement of pan support member, only in the thrust direction and the minor thrust direction of the piston.

For this reason, since the tray support member does not require a size that extends in the radial direction to the skirt portion, the tray support member can be configured compactly. Moreover, since the fastening only rocking direction of the piston of the thrust direction and the minor thrust direction of the piston is made, effectively fastening is performed in a direction that acts large combustion pressure, is possible to lower the risk of damage it can.

In addition, an elongated hole-shaped insertion hole through which the connecting rod is inserted is formed in the tray support member, and a rotation restriction that restricts the movement of the piston in the rotation direction at the side surface of the insertion hole and the flat portion formed on the connecting rod side. Therefore, the rotation restricting means for restricting the movement of the piston in the rotation direction is constituted by a plane portion formed on the side surface of the insertion hole of the tray support member and the connecting rod side. A separate member is not required for restricting the rotation of the piston, and this rotation restricting position can be performed at a position close to the rotation center of the piston, so that a compact configuration can be achieved. Therefore, it is possible to regulate the rotation of the piston while reducing the weight.

In one embodiment of the present invention, the bowl-shaped saucer portion is formed of a member separate from the connecting rod, the planar portion of the rotation restricting means is formed on the bowl-shaped saucer portion, and the bowl-shaped saucer portion is connected to the connecting rod. It is fastened and fixed to the rod with a fastening member.

According to the above configuration, the bowl-shaped saucer portion is configured by a member separate from the connecting rod, and the planar portion of the rotation restricting means is formed in the bowl-shaped saucer portion, and is fastened and fixed to the connecting rod by the fastening member. Will be.

For this reason, since a bowl-shaped saucer part can be shape | molded as another member, it can raise a shaping | molding precision. Further, by forming the flat portion of the rotation restricting means, it is possible to provide a rotation restricting function. Further, since the fastening operation is performed with the fastening member fixed and the position in the rotational direction of the bowl-shaped saucer portion temporarily fixed, the positioning of the bowl-shaped saucer portion can be easily performed.

In one embodiment of the invention, the thrust position and anti-thrust position of the piston, the skirt portion is provided, the fastening position of the upper and the pan supporting member of the skirt, depending from the piston crown, a thrust it is obtained by connected by a connecting rib extending in the direction and counter-thrust direction.

According to the above configuration, the at connecting ribs extending in the thrust direction and the anti-thrust direction, coupling the fastening position of the skirt portion and pan support member provided in the thrust position and anti-thrust position of the piston .

For this reason, since the rigidity of the fastening position of a saucer support member increases and movement, such as an excessive twist with respect to a saucer support member, does not arise, the possibility of damage to a saucer support member can be made lower. Further, when the ribs to the bottom of the skirt, but worsening of the lubrication excessively high rigidity of the skirt subordinate part by oil film. However, in the above arrangement, a rigid piston ring portion required of the skirt upper only it has provided a connecting rib portions, while maintaining lubricity, Ru can be ensured the rigidity required.

In one embodiment of the present invention, the bottom surface of the bowl-shaped saucer portion is substantially spherical, and the support surface that slidably supports the bowl-shaped saucer portion of the saucer support member is provided on the bottom surface of the bowl-shaped saucer portion. in larger radius than the spherical convex portion and a substantially conical curved surface that spherical centers are offset to a position further than the protrusion axis, and, Oyo contact portion is thrust direction between the bowl-shaped pan portion back surface beauty anti The composite curved surface is a parallel line extending in the thrust direction.

According to the above arrangement, since the support surface of the bowl-shaped pan portion of the pan support member, the contact portion between the bowl-shaped pan portion is a composite curved surface which becomes parallel lines extending in the thrust direction and the anti-thrust direction, also the support surface as provided so as to extend in the thrust direction and the anti-thrust direction, it is possible to secure the abutment of the bowl-shaped pan portion longer, to act locally surface pressure on the support surface In addition, it is possible to prevent damage such as cracks in the tray support member.

In one embodiment of the present invention, the spherical concave portion of the bowl-shaped saucer portion has a radius larger than the radius of the spherical convex portion of the piston, and the center of the spherical surface is farther than the spherical convex portion axis of the piston. It is made into the substantially cone-shaped curved surface shape offset by.

  Normally, when the slidable contact surface is formed by the spherical convex portion and the spherical concave portion, the spherical concave portion side is a curved surface having a large radius, but in that case, the contact portion becomes one point and the surface pressure becomes high. According to the above configuration, since the spherical concave portion of the bowl-shaped saucer portion and the spherical convex portion of the piston are always in sliding contact with the annular contact surface, the surface pressure generated between the two is reduced by dispersing it. Can do. Also, the processing of the spherical concave portion can be easily performed because it is not necessary to consider the coincidence of the curved surface with the spherical convex portion.

  In one embodiment of the present invention, a hollow hollow portion is formed in the center of the spherical convex portion of the piston.

  According to the above configuration, the lightening portion is formed at the center of the spherical convex portion of the piston, so that the weight of the piston can be further reduced.

  In one embodiment of the present invention, a groove is formed on the outer peripheral surface of the bowl-shaped saucer.

  According to the said structure, since the groove part was formed in the outer peripheral surface of a bowl-shaped saucer part, weight reduction of a piston can be achieved further.

  In one embodiment of the present invention, the piston spherical convex portion is set such that the upper portion of the virtual spherical body including the sliding spherical surface of the spherical convex portion of the piston protrudes upward from the upper surface of the crown portion. .

According to the above configuration, while securing the sliding contact surface to the charge amount, since the connecting position between the piston and the connecting rod can be set on the upper side, it is possible to shorten the piston full length, weight reduction of more pistons Can be achieved.

According to this invention, since the tray support member does not require a size that extends in the radial direction to the skirt portion, it can be configured compactly. Moreover, since the fastening only rocking direction of the piston of the thrust direction and the minor thrust direction of the piston is made, effectively fastening is performed in a direction that acts large combustion pressure, that you damage it even lower it can.

  Therefore, in a connection structure for connecting a connecting rod and a piston in an engine, in order to reduce the weight of the piston, the connecting rod and the piston are connected by a sliding contact between a spherical convex portion and a spherical concave portion. The support member for supporting the tray used in the above can be made compact and lightweight while preventing the support member from being easily damaged.

In addition, an elongated hole-shaped insertion hole through which the connecting rod is inserted is formed in the tray support member, and a rotation restriction that restricts the movement of the piston in the rotation direction at the side surface of the insertion hole and the flat portion formed on the connecting rod side. Therefore, the rotation restricting means for restricting the movement of the piston in the rotation direction is constituted by a plane portion formed on the side surface of the insertion hole of the tray support member and the connecting rod side. A separate member is not required for restricting the rotation of the piston, and this rotation restricting position can be performed at a position close to the rotation center of the piston, so that a compact configuration can be achieved. Therefore, there is an effect that it is possible to regulate the rotation of the piston while reducing the weight.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a front view of a piston assembly 1 adopting the connecting rod-piston connection structure of the present embodiment as viewed from the crankshaft direction, FIG. 2 is a side view of the piston assembly 1, and FIG. 4 is a cross-sectional view taken along line A-B in FIG. 2, FIG. 5 is a bottom view of the piston assembly 1, and FIG. 6 is a perspective view from below of the piston assembly.

Piston assembly 1 of the present embodiment, in Cylinders series four-cylinder engine, with a reciprocating motion in the vertical direction, and a crank shaft (not shown) to rotate through the connecting rod 2.

The piston assembly 1 is in sliding contact with a cylindrical cup-shaped piston body 3 having a crown portion 31 on the upper portion and a spherical convex portion 34 projecting from the crown portion 31 below the crown portion 31 of the piston body 3. a bowl-like receptacle member 4, the pan supporting member 5 which supports slidably the bowl-like receptacle member 4 from below, the upper end bowl-like receptacle member 4 is fixed to the connecting rod crankshaft is fitted to the lower end It consists of two.

The aforementioned piston body 3 is made of an aluminum alloy for weight reduction, and a crown part 31 provided on the upper part of the piston body 3 and skirt parts 32 and 33 provided on the thrust position and the anti-thrust position on the outer periphery of the piston body 3 respectively. A spherical convex portion 34 projecting from the center of the lower portion of the crown portion 31; fastening boss portions 35, 35 projecting from the lower portion of the crown portion 31 on the thrust side and the anti-thrust side so as to sandwich the spherical convex portion 34; The connecting rib portions 36, 36 for connecting the portions 32, 33 and the fastening boss portions 35, 35 extending in the thrust direction and the anti-thrust direction and the skirt portions 32, 33 extending in the thrust direction and the anti-thrust direction are extended to the skirt portion. And thrust direction ribs 37 and 37 for connecting the members 32 and 33 .

  As shown in FIG. 3, the crown portion 31 has a flat upper surface concave portion 31a constituting a combustion chamber formed on the upper surface thereof, and a ring groove 31c for mounting a piston ring on the outer peripheral portion 31b. Further, a lower surface recess 31d set thinner than the outer peripheral portion 31b is formed on the lower surface.

Skirt 32, 33, thrust position a swinging direction of the piston body 3, respectively, provided on the anti-thrust position, so that the piston body 3 is properly moved up and down within Cylinders, the outer peripheral portion 31b of the crown portion 31 It is comprised by the circular arc shape extended from the bottom as it is.

Spherical convex portion 34 is projected from the center of the crown portion 31 lower, it is constituted by the thrust direction, off the sides perpendicular to the anti-thrust direction-away partially spherical body. By using a partial spherical body in this way, a portion that is not directly related to swinging can be deleted from the piston main body 3, so that the weight can be reduced.

  A cylindrical hollow portion 34 a is formed at the center of the spherical convex portion 34. By providing the thinned portion 34a in this way, the meat at this portion can be deleted, so that further weight reduction can be achieved.

Further, the sliding spherical surface 34b of the spherical convex portion 34 is set so that the virtual spherical body Q including the sliding spherical surface 34b protrudes upward from the upper surface of the crown portion 31 as shown in FIG. ing. Thus, by setting such virtual spherical body Q protrudes above the crown portion 31 upper surface, even while maintaining a sliding contact portion to the charge amount, the connection between the piston body 3 and the connecting rod 2 Since the position can be set on the upper side, the total length of the piston body 3 can be shortened, and the weight of the piston assembly 1 can be further reduced.

  The fastening boss portions 35, 35 are provided in a cylindrical shape at two locations on the thrust side and the anti-thrust side below the crown portion 31, and are provided for fastening and fixing the tray support member 5 to the lower portion of the crown portion 31. .

  The amount of protrusion of the fastening boss portions 35, 35 is also set slightly smaller than the above-described spherical convex portion 34, and the amount of protrusion is reduced as much as possible to reduce the weight.

The connecting rib portions 36, 36 connect the upper portions of the skirt portions 32, 33 and the fastening boss portions 35, 35 in the thrust direction and the anti-thrust direction. By providing the connecting rib portions 36 and 36 as described above, the rigidity from the upper portions of the fastening boss portions 35 and 35 and the skirt portions 32 and 33 to the ring groove 31c portion can be increased. In particular, by increasing the rigidity of the fastening boss portions 35, 35, the fastening portion of the saucer support member 5 is firmly fixed, so that the saucer support member 5 is not twisted. Therefore, since an extra burden is not imposed on the tray support member 5, the risk of breakage can be reduced.

The thrust direction rib portions 37 and 37 extend and connect the end portions of the skirt portions 32 and 33 in the thrust direction and the anti-thrust direction, thereby increasing the rigidity of the skirt portions 32 and 33.
The above-mentioned bowl-shaped saucer member 4 is composed of a cup-shaped member fastened and fixed to the upper end of the connecting rod 2, and is in sliding contact with the above-mentioned spherical convex portion 34 at the upper spherical concave portion 41.

  As shown in FIG. 3, the sliding spherical surface 41a of the spherical concave portion 41 has a conical compound curved surface shape in which curved surfaces having a radius R larger than the radius of the sliding spherical surface 34b of the spherical convex portion 34 are combined. By adopting such a conical compound curved surface shape, the spherical concave portion 41 always abuts against the sliding spherical surface 34b of the spherical convex portion 34 at the annular abutting portion. The surface pressure between the parts 34 can be dispersed and lowered. Also, the processing of the spherical concave portion 41 can be easily performed because it is not necessary to consider the exact coincidence of the curved surface with the spherical convex portion 34.

The cylindrical portion 42 at the lower end of the bowl-shaped saucer member 4 is formed with a flat portion 42 a that restricts the movement of the piston body 3 in the rotational direction. The flat surface portion 42a is configured to regulate the rotation of the piston body 3 by bringing a side surface of an insertion hole 51 of the tray support member 5 described later into contact therewith.

  In addition, a groove 43 is formed on the outer peripheral surface of the bowl-shaped tray member 4. Since the mass of the bowl-shaped saucer member 4 can be reduced by forming such a groove part 43, weight reduction can be achieved.

  Further, a spherical convex portion 44 that abuts the tray support member 5 is formed on the lower surface of the bowl-shaped tray member 4.

The tray support member 5 described above is formed of a substantially rectangular cube extending in the thrust direction and the anti-thrust direction in which a long hole-shaped insertion hole 51 is formed at the center, and bolt holes 52 through which fastening bolts 6 and 6 are inserted. , 52 are formed. Further, a curved support surface 54 that slidably supports the bowl-shaped saucer member 4 is provided on the upper part of the saucer support member 5, and a thrust direction and an anti-thrust direction with a predetermined thickness are provided on the lower part to increase the support rigidity. The beam part 55 extended in this is provided.

As will be described later, the support surface 54 is composed of a complex curved surface in which a contact portion with the bowl-shaped saucer member 4 has a parallel line shape extending in the thrust direction and the anti-thrust direction, and is a local surface on the support surface 54. The pressure is prevented from acting.

Further, the fastening portions 53 and 53 extend in the thrust direction and the anti-thrust direction, and the tray support member 5 is fastened and fixed to the fastening boss portions 35 and 35 on the lower surface of the crown portion 31 via the fastening bolts 6 and 6.

Thus, the receiving tray support member 5 is sized to extend in the radial direction to the skirt portions 32 and 33 by being fastened to the lower surface of the crown portion 31 by the fastening portions 53 and 53 extending in the thrust direction and the anti-thrust direction. Since it is not necessary, it can be made compact. Further, since the fastening is effectively performed in the direction in which the combustion pressure acts greatly, the risk of breakage can be reduced.

  Therefore, it is possible to reduce the weight by configuring the tray support member 5 to be compact while preventing damage to the tray support member 5.

  The fastening bolts 6 and 6 that fasten the tray support member 5 are two hexagon socket bolts. By fastening and fixing with such a hole bolt, the bolt head can be made smaller, and thus the weight of the piston assembly 1 can be further reduced.

Further, the insertion hole 51 is formed in a rectangular shape extending in the thrust direction and the anti-thrust direction so as not to interfere with the swinging connecting rod 2, and the inner side surface 51 a is formed on the flat portion 42 a formed in the bowl-shaped saucer member 4. It is comprised so that rotation control of the piston main body 3 may be performed by making it contact.

  In this way, by restricting the rotation by the saucer support member 5 and the bowl-like saucer member 4, no additional member is required for restricting the rotation of the piston body 3, and this rotation restriction position is also set at the piston body 3. Since it can be performed at a position close to the center of rotation, it can be made compact.

The beam portion 55 is configured to have a predetermined thickness in the vertical direction in order to securely hold the support surface 54 that receives the combustion pressure, and in order to ensure uniform rigidity, in the thrust direction in the side view, anti-thrust It has a fan shape extending in the direction.

  The aforementioned connecting rod 2 fastens the rod-shaped saucer member 4 to the rod-shaped saucer member 4 having an H-shaped cross section composed of flat plate portions 21 and 21 provided on both sides of the swinging direction and a connecting portion 22 for connecting the flat plate portions. And a fastening seat 24 at the upper end. The connecting rod 2 is formed of a forged product and reliably transmits a load from the large piston body 3 to the crankshaft.

  The connecting rod 2 and the bowl-shaped saucer member 4 may be integrally molded. However, when the molding accuracy of the bowl-shaped saucer member 4 is increased or the material is changed, as in the present embodiment. It is desirable to mold it separately.

  Further, the connecting rod 2 and the bowl-shaped saucer member 4 are fastened by a single saucer fastening bolt 7. Thus, by fastening with another saucer fastening bolt 7, it is possible to perform fastening and fixing after prescribing (temporarily fixing) the position in the rotational direction of the bowl-shaped saucer member 4 when fastening and fixing. Become. Thereby, since the position of the rotation direction of the bowl-shaped saucer member 4 which has the function of restricting the rotation of the piston body 3 can be easily defined, the positioning of the bowl-shaped saucer member 4 can be easily performed.

7 to 9 are single product diagrams of the respective parts. Figure 7 is a sectional perspective view of the piston body 3, Fig. 8 is a connecting rod 2 upper, and a perspective view of a bowl-like receptacle member 4 which is fastened at its upper end, Figure 9 is a pan supporting member 5 (a) plane It is a figure, (b) Front view, (c) Side view, (d) CC sectional view taken on the line.

First, the piston body 3 shown in FIG. 7 is formed into a cylindrical cup shape as described above, and a spherical convex portion 34, a fastening boss portion 35, and a lower portion of the crown portion 31 are projected from the lower surface concave portion 31d. connecting rib portion 36, and is provided with a thrust rib sections 37.

The connecting rib portion 36 is set so that its length in the vertical direction gradually increases as it goes in the thrust direction and the anti-thrust direction. By setting the length of the connecting rib portion 36 so as to gradually change in this way, since no sudden rigidity change occurs in the connecting rib portion 36, stress concentration is less likely to occur and the risk of breakage is reduced. Can do.

  Further, the connecting rod 2 shown in FIG. 8 includes the rod portion 23 having the H-shaped cross section and the fastening seat portion 24 as described above, and the hook-shaped saucer member 4 is fastened and fixed by the fastening seat portion 24 in the vertical direction. Yes. The hook-shaped saucer member 4 is fastened and fixed to the connecting rod 2 after the position in the rotational direction is defined by the saucer fastening bolt 7 as described above.

  The tray support member 5 shown in FIG. 9 is provided with the insertion hole 51 at the center, the fastening portions 53 and 53 at the end in the thrust direction and the anti-thrust direction, the support surface 54 at the upper portion, and the beam portion 55 at the lower portion as described above. .

Among these, as shown in FIG. 9 (a), the support surface 54 is composed of a complex curved surface in which the contact portion T with the bowl-shaped tray member 4 is a parallel line extending in the thrust direction and the anti-thrust direction. In addition, local surface pressure is prevented from acting on the support surface 54.

Specifically, as shown in FIG. 9 (d), the radius U is larger than the virtual spherical body 4Q including the spherical convex portion 44 on the lower surface of the bowl-shaped saucer portion 4, and the spherical center P is the spherical convex portion 34. Based on a substantially conical curved surface offset to a position farther from the axis of the base, the contact portion with the bowl-shaped saucer member 4 becomes an annular contact portion as it is, and due to the presence of the insertion hole 51, the annular contact portion Since the thrust direction and the anti-thrust direction are interrupted, the contact portion T with the bowl-shaped saucer member 4 is formed by configuring the substantially conical curved surface as a composite curved surface slightly extended in the thrust direction and the anti-thrust direction. They can be parallel lines.

The support surface 54, by the such compound curves, it is possible even if made compact the pan supporting member 5 in a rectangular shape, to ensure a contact area to the charge amount, local surface to the support surface 54 The pressure can be prevented from acting, and the risk of breakage can be reduced.

Next, it will be described in detail acts and effects of this embodiment constructed as described above.
The connecting structure of the connecting rod 2 and the piston body 3 of the engine according to this embodiment is a connecting structure of the connecting rod 2 and the piston body 3 of the engine that connects the connecting rod 2 and the piston body 3, and is a crown of the piston body 3. A spherical convex portion 34 formed on the lower surface of the portion 31 and projecting downward; and a bowl-shaped saucer member 4 provided on the upper end of the connecting rod 2 and having a spherical concave portion 41 that is in sliding contact with the spherical convex portion 34; concluded bowl-like receptacle member 4 slidably supported from below, has a fastening portion 53, 53 which extend only in the thrust direction and the anti-thrust direction, the crown portion 31 the lower surface in the fastening portion 53, 53 The tray support member 5 is provided.

According to the above configuration, the piston body 3 and the connecting rod 2 are slid by the spherical convex portion 34 formed on the lower surface of the crown portion 31 and the bowl-shaped saucer member 4 having the spherical concave portion 41 at the upper end of the connecting rod 2. The piston body 3 and the connecting rod 2 are connected by contacting and fixing the bowl-shaped tray member 4 to the piston body 3 with the tray support member 5. Then, the engagement of pan support member 5, the fastening section 53 and 53 which extend only in the thrust direction and the minor thrust direction.

For this reason, since the tray support member 5 does not need to be large enough to extend in the radial direction to the skirt portions 32 and 33, the tray support member 5 can be configured compactly. Moreover, since the fastening only rocking direction of the piston of the thrust direction and the minor thrust direction of the piston is made, effectively fastening is performed in a direction that acts large combustion pressure, is possible to lower the risk of damage it can.

  Therefore, in the connecting structure for connecting the connecting rod 2 and the piston main body 3 in the engine, in order to reduce the weight of the piston assembly 1, the connecting rod 2 and the piston main body 3 are brought into sliding contact with the spherical convex portion 34 and the spherical concave portion 41. The tray support member 5 that supports the bowl-shaped tray member 4 used at the time of the sliding contact is not easily damaged, but can be made compact to reduce the weight.

Further, in this embodiment, the thrust position and anti-thrust position of the piston body 1, the skirt portion 32 is provided, the fastening boss said with the skirt portion 32, 33 upper receiving tray support member 5 is fastened 35, depending from the crown portion 31, is the concatenation in connection rib portions 36 and 36 extending in the thrust and counter-thrust direction.

According to the above configuration, fastened with connecting ribs 36 and 36 extending in the thrust direction and the anti-thrust direction, in which the skirt portion 32, 33 and the tray supporting member 5 which is provided in the thrust position and anti-thrust position is fastened The boss part 35 is connected.

  For this reason, since the rigidity of the fastening position of the saucer support member 5 is increased and no movement such as an excessive twist with respect to the saucer support member 5 occurs, the possibility of damage to the saucer support member 5 can be further reduced. Further, if ribs are provided to the lower part of the skirt parts 32 and 33, the rigidity of the lower part of the skirt parts 32 and 33 becomes too high, and it is conceivable that the lubricity deteriorates due to oil film breakage. The connecting rib portions 36, 36 are provided only from the portion to the upper portions of the skirt portions 32, 33, so that necessary rigidity can be ensured while ensuring lubricity.

  Further, in this embodiment, an elongated hole-shaped insertion hole 51 through which the connecting rod 2 is inserted is formed in the tray support member 5, and a flat portion 42 a formed in the side surface 51 a of the insertion hole 51 and the bowl-shaped tray member 4. Thus, a rotation restricting means for restricting the movement of the piston body 3 in the rotation direction is configured.

  According to the above configuration, the rotation restricting means for restricting the movement of the piston body 3 in the rotation direction is configured by the side surface of the insertion hole 51 of the tray support member 5 and the flat portion 42 a formed in the bowl-shaped tray member 4. .

  For this reason, a separate member is not required for restricting the rotation of the piston main body 3, and the rotation restricting position can also be performed at a position close to the rotation center of the piston main body 3. Therefore, a compact configuration can be achieved. Therefore, it is possible to restrict the rotation of the piston body 3 while reducing the weight.

  Moreover, in this embodiment, the said bowl-shaped saucer member 4 is comprised by a member different from the connecting rod 2, the said flat part 42a is formed in this bowl-shaped saucer member 4, and this bowl-shaped saucer member 4 is connected to a connecting rod. 2 is fastened and fixed with a saucer fastening bolt 7.

  According to the above configuration, the bowl-shaped saucer member 4 is constituted by a member separate from the connecting rod 2, and the planar part 42 a is formed on the bowl-like saucer member 4, and the saucer fastening bolt 7 is formed with respect to the connecting rod 2. It will be fastened and fixed.

  For this reason, since the bowl-shaped saucer member 4 can be shape | molded as another member, it can raise a shaping | molding precision and can also have a function of rotation control by forming the plane part 42a. Furthermore, since the fastening operation can be performed with the position in the rotational direction of the bowl-shaped saucer member 4 temporarily fixed since the bowl-shaped saucer member 7 is fastened and fixed, the positioning of the bowl-shaped saucer member 4 can be easily performed.

Further, in this embodiment, the bottom surface of the bowl-shaped saucer member 4 has a substantially spherical surface, and the support surface 54 slidably supports the bowl-shaped saucer portion (see the bowl-shaped saucer member 4) of the tray support member 5. Is a substantially cone-shaped curved surface having a larger radius than the spherical convex portion 44 on the lower surface of the bowl-shaped saucer portion (see the bowl-shaped saucer member 4) and a center of the spherical surface offset to a position farther than the convex axis. Jo saucer section in which the contact portion T of the (bowl-shaped receptacle member 4 reference) back surface has a composite curved surface becomes parallel lines extending in the thrust direction and the minor thrust direction.

According to the above arrangement, the support surface 54 of the bowl-like receptacle member 4 of the pan supporting member 5, the parallel lines of contact portion T of the bowl-like receptacle member 4 extends in a thrust direction and the anti-thrust direction complex Since it is a curved surface, the contact portion T of the bowl-shaped saucer member 4 can be secured long, so that local surface pressure does not act on the support surface 54, and the saucer support member 5 is damaged such as cracks. Can be prevented.

  Further, in this embodiment, the spherical concave portion 41 of the bowl-shaped saucer member 4 has a conical compound curved surface shape in which curved surfaces having a radius R larger than the radius of the spherical convex portion 34 of the piston body 3 are combined. .

According to the above configuration, the spherical concave portion 41 of the bowl-shaped saucer member 4 and the spherical convex portion 34 of the piston body 3 are always in sliding contact with each other at the annular contact portion, so that the surface pressure generated therebetween is dispersed. Can be lowered. Further, the processing of the spherical concave portion 41 can be easily performed because it is not necessary to consider the coincidence of the curved surface with the spherical convex portion 34.
In this embodiment, a hollow hollow portion 34 a is formed in the center of the spherical convex portion 34 of the piston body 3.

  According to the said structure, since the thinning part 34a was formed in the center of the spherical convex part 34 of the piston main body 3, the weight reduction of the piston main body 3 can be achieved further.

  Moreover, in this embodiment, the groove part 43 is formed in the outer peripheral surface of the said bowl-shaped saucer member 4. As shown in FIG.

  According to the said structure, since the groove part 43 was formed in the outer peripheral surface of the bowl-shaped saucer member 4, the weight reduction of the piston assembly 1 can be achieved further.

Further, in this embodiment, the spherical convex of the piston body 3 is such that the upper part of the virtual spherical body Q including the sliding spherical surface 34b of the spherical convex part 34 of the piston body 3 protrudes upward from the upper surface of the crown part 31. The unit 34 is set.

According to the above configuration, while securing the sliding contact surface to the charge amount, since the connecting position of the piston body 3 and the connecting rod 2 can be set on the upper side, it is possible to shorten the overall length of the piston body 3, The weight of the piston body 3 can be further reduced.

As described above, in the correspondence between the configuration of the present invention and the above-described embodiment,
The piston of the present invention corresponds to the piston body 3 of the embodiment,
The bowl-shaped saucer portion of the invention corresponds to the bowl-shaped saucer member 4 of the embodiment,
The present invention is not limited to the configuration of the above-described embodiment, but includes embodiments applied to various engine pistons.

The front view of the piston assembly which employ | adopted this invention. The side view of a piston assembly. FIG. 2 is a cross-sectional view taken along line AA in FIG. 1. FIG. 3 is a sectional view taken along line B-B in FIG. 2. The bottom view of a piston assembly. The lower perspective view of a piston assembly. The cross-sectional perspective view of a piston main body. The perspective view of a connecting rod and a bowl-shaped saucer member. (A) Top view of a saucer support member, (b) Front view, (c) Side view, (d) CC sectional view taken on the line.

DESCRIPTION OF SYMBOLS 1 ... Piston assembly 2 ... Connecting rod 3 ... Piston main body (piston)
4 ... A bowl-shaped saucer member (a bowl-shaped saucer part)
5 ... Tray support member 6 ... Fastening bolt
7 ... Dish fastening bolt
31 ... Crown
32, 33 ... Skirt
34 ... Spherical convex part
34a ... Meat extraction part
34b ... Sliding spherical surface
35 ... Fastening boss
36 ... Connecting rib part
41 ... spherical recess
42a ... plane part
43 ... Groove
44 ... Spherical convex part
51 ... insertion hole
51a ... Side surface 53 ... Fastening part
54 ... Support surface
Q ... Virtual spherical body
T ... Contact part

Claims (8)

A connection structure of the connecting rod and the piston of the engine for coupling the connecting rod and the piston,
A spherical convex portion formed on the lower surface of the crown portion of the piston and projecting downward;
A bowl-shaped saucer portion provided at an upper end of the connecting rod and having a spherical concave portion that is in sliding contact with the spherical convex portion;
Slidably supporting the該椀shaped pan portion from below, only has a fastening portion for extending thrust direction and the minor thrust direction of the piston, pan support member is fastened to the crown lower surface in the fastening portion It equipped with a door,
In the saucer support member, an elongated hole-shaped insertion hole for inserting a connecting rod is formed,
A structure for connecting the connecting rod and the piston of the engine, wherein the side surface of the insertion hole and the flat portion formed on the connecting rod side constitute a rotation restricting means for restricting the movement of the piston in the rotational direction . The bowl-shaped saucer portion is configured by a separate member from the connecting rod,
Forming a flat portion of the rotation restricting means in the bowl-shaped saucer portion;
The connecting structure of the connecting rod and piston of the engine according to claim 1 , wherein the bowl-shaped saucer portion is fastened and fixed to the connecting rod by a fastening member . A skirt portion is provided at the thrust position and the anti-thrust position of the piston,
The fastening position of the upper and the pan supporting member of the skirt portion, the piston depending from the crown portion, the thrust direction and the connecting rod anti-thrust direction extending connecting ribs were <br/> claim 1 Symbol placement linked portion engine And piston connection structure. The bottom surface of the bowl-shaped saucer portion is substantially spherical, and the support surface that slidably supports the bowl-shaped saucer portion of the saucer support member has a larger radius than the spherical convex portion of the bottom surface of the bowl-shaped saucer portion, and The center of the spherical surface is a substantially conical curved surface offset to a position far from the center of the convex portion, and the curved surface is a composite curved surface in which the contact portion with the rear surface of the bowl-shaped saucer is a parallel line extending in the thrust direction and the anti-thrust direction. The connecting structure of the connecting rod and piston of the engine according to any one of claims 1 to 3. The spherical concave portion of the bowl-shaped saucer portion has a substantially conical curved surface shape having a radius larger than the radius of the spherical convex portion of the piston and a center of the spherical surface offset to a position farther from the spherical convex portion axis of the piston. the <br/> connection structure of the connecting rod and the piston of the engine according to any one of claims 1 to 4. The connecting structure of an engine connecting rod and a piston according to any one of claims 1 to 5 , wherein a hollow hollow portion is formed in the center of the spherical convex portion of the piston. The connecting structure for connecting an engine connecting rod and a piston according to any one of claims 1 to 6 , wherein a groove is formed on an outer peripheral surface of the bowl-shaped saucer . The top of the virtual sphere containing the sliding spherical surface of the spherical convex portion of the piston, so as to protrude above the crown top surface, any <br/> claims 1 to 7, setting the spherical convex portion of the piston whether the engine connecting rod and the piston of the communicating fine granulation of the described 1.

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