JP2007085493A - Shell type roller bearing for laminated connecting rod and connecting rod assembly - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shell type roller bearing for a laminated connecting rod and a connecting rod assembly, restraining skew of a roller to prevent the occurrence of lateral running. <P>SOLUTION: A cage 13 is formed to have a sectional form such that the middle part in the width direction is recessed toward the inside diameter more than both end parts by press molding, and a pocket 14 is provided in a plurality of parts in the circumferential direction to take a part between the adjacent pockets 14, 14 as a column part 13b. A shear plane 14a part is shaped to be locally projected partially in the longitudinal direction of the pocket not to have a buildup part. In this flat shape, the cage 13 is press-molded in the state of a band steel to have a sectional shape such that the middle part in the width direction is recessed, and then the pocket is punched. A shell-type outer ring is such that on the basis of the inside diameter surface of a reference ring in which this shell type outer ring is pressed, the generating line shape of a range where the roller rolls in the width direction in the rolling surface is set to a straightness of 0.008 or less, and a parallelism of 0.015 or less. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a shell-type roller bearing and a connecting rod assembly for a laminated connecting rod used in an engine.

  A connecting rod used for an engine is manufactured by forging, sintering, or constraining pressure forming from a steel bar or plate material. In addition, it may be formed by stamping by pressing a steel plate. When the connecting rod is manufactured by such forging or sintering, it is difficult to reduce the cost because of the large number of steps. In addition, when machining a hole or the like in the connecting rod, grinding or the like is performed, which further increases the number of steps.

  Therefore, a connecting rod assembly that can be manufactured easily and inexpensively, avoids inclination of bearings and the like attached to the large end portion and the small end portion, and can improve bending strength and buckling strength, respectively, as a large end portion, a small end portion, In addition, a plate-shaped divided connecting rod part having a rod portion is laminated, and a coupling protrusion pressed on the rod portion and a recess formed on the back surface of the protrusion are engaged with each other, or a through formed separately from the protrusion There has been proposed one in which a laminated body in which the divided connecting rod parts are laminated is fixed integrally so that adjacent divided rod parts are coupled to each other by meshing with the holes (for example, Patent Document 1).

  According to this configuration, since each divided connecting rod component is laminated, the inner diameter surfaces of the large end portion and the small end portion of the laminated body are inclined even if the inner diameter surfaces of the large end portion and the small end portion of each divided connecting rod component are inclined. Can be eliminated. For example, when each divided connecting rod part is a normal stamped product, the inner divided surface of the large end portion and the small end portion is inclined due to the fracture surface in each divided connecting rod component. Since the plate thickness is reduced, the level difference between the shear plane and the fracture surface is reduced, and the fracture surfaces are dispersed and arranged by lamination. For this reason, the inclination of the internal-diameter surface of the large end part as a whole of a laminated body and a small end part can be avoided. Therefore, even if a shell type bearing is press-fitted into the large end portion and the small end portion, no inclination occurs in the press-fitted shell type bearing. For this reason, a press-punched product can be adopted for each divided connecting rod part, and post-processing such as grinding and polishing of the large end portion and the small end portion becomes unnecessary. Therefore, the connecting rod assembly can be manufactured easily and inexpensively.

  In addition, the laminated divided connecting rod parts are joined to each other by meshing with a coupling projection pressed on the rod portion and a recess formed on the back surface of the projection, or with a through hole formed separately from the projection. Because they are joined, they can be joined firmly. Since the laminated divided connecting rod parts are joined by the protrusions and the recesses, the bending strength and buckling strength of the rod portion are improved. Since the protrusions and the recesses on the back surface are formed by press working, they can be easily formed.

  The connecting rod assembly includes, as a bearing, a shell-type outer ring formed by press working including a drawing process, a plurality of needle rollers arranged along the inner diameter surface of the outer ring, and a cage that holds the needle rollers. The shell type roller bearing can be used. FIG. 13 shows a partial cross-sectional view of this shell type roller bearing. In the cage 33 of the shell type roller bearing 24, the band steel is pocketed by press working and formed into a V-shaped foam (a cross-sectional shape in which the intermediate portion in the cage width direction is recessed from both end portions), and then in a band shape. What was manufactured by the process of shape | molding in cylindrical shape after cut | disconnecting and joining the circumferential direction both end surfaces of the cylinder by welding is used.

The cage 33 is formed into a V-shaped foam in order to increase the apparent sectional height in the radial direction while reducing the thickness by reducing the plate thickness. Increasing the apparent cross-sectional height in the radial direction is for the purposes listed below.
In the manufacturing process, the inner diameter of the cage 33 is made small in a state of being formed into a cylindrical shape, and the needle rollers 32 are prevented from coming out from the inner diameter side of the cage 33.
In the state where the shaft 30 is inserted into the shell-type roller bearing 24 as shown in FIG. The roller 32 is brought into contact with the column portion 33 b of the cage 33.
-By adjusting the apparent cross-sectional height, the cage 33 can be guided on any part of the shaft 30, the shell-type outer ring 31, and the rolling element.

The cage 33 manufactured in this manner can prevent the needle rollers 32 from falling off while stabilizing the behavior of the needle rollers 32. Further, since the manufacturing cost is low and the economic advantage is high, many other It is also used for applications.
JP 2004-324760 A

  When the shell type roller bearing 24 having the above-described configuration is used for the connecting rod assembly described above for a two-cycle engine, the lateral surface of the shell type outer ring 31 contacts the engine counterpart surface due to the lateral running of the bearing in the thrust direction. , Heat generation and seizure may occur. The reasons are summarized as follows.

  Due to the characteristics of the pocket punching press processing of the cage 33, a shearing surface is generated on the punch insertion side on the inner peripheral surface of the pocket, and a fracture surface is generated on the anti-punch insertion side. As shown in a cross-sectional view when the cage 33 is cut in the circumferential direction in FIG. 14, the punch 33 is inserted from the outer diameter side in a state of being formed into a cylindrical shape. A shear surface 34a is generated on the outer diameter side of the inner surface, and a fracture surface 34b is generated on the inner diameter side. The shear surface 34a has a flat shape, whereas the fracture surface 34b has a shape that is stripped. Therefore, the pocket size on the inner surface of the pocket that becomes the fracture surface 34b is larger than the pocket size on the inner surface of the pocket that becomes the shear surface 34a, and the radial position of the shear surface 34a and the fracture surface 34b in the vicinity of the same PCD. In this case, the needle roller 32 is restrained by the shear surface 34a.

  FIG. 15 is a cross-sectional view of the pocket 34 portion of the retainer 33 in which the column portion 33b is formed into a V-shaped foam, cut in the longitudinal direction (retainer width direction). On the inner surface of the pocket in the figure, the white portion is the generation position of the shear surface 34a, and the hatched portion is the generation position of the fracture surface 34b. Further, in the figure, the position corresponding to the PCD of the needle roller 32 when the shaft 30 (FIG. 13) is inserted is indicated by a line segment 35, and the position overlapping the cage shear surface 34a on the line segment 35, that is, the needle A portion where the roller 32 contacts the shearing surface 34 a is indicated by a line segment 36. As can be seen from FIG. 15, the center portion of the needle roller 32 is in contact with the shear surface 34 a near the center portion of the retainer column portion 33 b.

However, in actuality, the local contact is as follows. That is, FIG. 16 shows the surface shape measurement result of the pocket inner surface at the position of the PCD equivalent line segment 35 of the needle roller 32 in FIG. As shown in the figure, a raised portion 38 is generated on both sides of the central bent portion of the retainer column portion 33b, and the raised portion 38 is not in contact with the entire shear surface of the central portion of the retainer column portion 33b. It contacts with the needle roller 32 at two points.
In the case of the conventional cage 33, this is generated in the V-shaped foam after the pocket is removed, and therefore, the surplus on the outer diameter side of the bent portion of the column portion 33b is shifted to the pocket surface side. In addition, it is difficult to adjust the amount of swell of the swelled portion 38 in manufacturing, and the swell amount becomes unstable.
Therefore, the needle roller 32 and the cage 33 are in contact at two points where the rising amount is unstable, so that the needle roller 32 is inclined, skew is likely to occur, and the bearing runs sideways in the thrust direction and seizes. Had occurred.

  In addition, in the shape of the generatrix on the rolling surface of the shell-type outer ring, even when the straightness and parallelism of the rolling range of the roller are poor, the contact between the outer ring 31 and the needle roller 32 is not stable, and the skew described above. It was found that this could cause lateral running of the bearings.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a shell-type roller bearing and a connecting rod assembly for a laminated connecting rod that can prevent the occurrence of lateral running by suppressing roller skew while using a press cage having a simple configuration.

A shell type roller bearing for a laminated connecting rod according to the present invention includes a plate-like divided connecting rod component having a large end portion, a small end portion, and a rod portion, respectively, and a connecting projection formed by pressing the rod portion, Laminated connecting rods that connect adjacent divided connecting rod parts to each other by meshing with a recess formed on the back surface of the projection or with a through hole formed separately from the projection, an outer ring, a plurality of rollers, and a plurality of these A shell-type roller bearing in a connecting rod assembly comprising a cage-type roller bearing having a retainer for holding the roller and the outer ring being press-fitted into a large or small bearing fitting hole in the laminated connecting rod,
The retainer is press-molded in a cross-sectional shape in which the intermediate portion in the width direction is recessed toward the inner diameter side than both end portions, pockets are provided at a plurality of locations in the circumferential direction, and a portion between adjacent pockets becomes a column portion The portion of the shear surface on the inner surface along the longitudinal direction of the pocket is a flat shape without a raised portion that locally projects in a part of the pocket longitudinal direction,
The shell-type outer ring has a generatrix shape in a width direction range in which the roller on the rolling surface rolls with respect to the inner diameter surface of the reference ring into which the shell-type outer ring is press-fitted. And parallelism: 0.015 or less.
The flat shape without the raised portion on the inner surface of the pocket of the cage is formed by pressing the cage into a cross-sectional shape in which the intermediate portion in the width direction is recessed from both end portions in the state of band steel, and then pocketing is performed. This can be achieved.

According to this configuration, the press cage of the shell type roller bearing has a flat shape in which the portion of the shear surface on the inner surface along the longitudinal direction of the pocket does not have a raised portion that locally projects in a part of the pocket longitudinal direction. . Therefore, the roller comes into contact with the flat shear surface on the inner surface of the pocket of the cage. Therefore, when this shell type roller bearing is operated by being incorporated in a connecting rod assembly of a two-cycle engine, for example, the roller and the cage come into stable contact.
In addition, the shell-type outer ring has a generatrix in the width direction range in which the roller on the rolling surface rolls with respect to the inner diameter surface of the reference ring into which the shell-type outer ring is press-fitted. Straightness: 0.008 or less In addition, since it has a flat rolling surface shape with a parallelism of 0.015 or less, this also stabilizes the contact with the outer ring.
For these reasons, roller skew is suppressed, and lateral running of the bearing in the thrust direction is eliminated. As a result, the contact between the width surface of the shell-type outer ring and the engine counterpart component can be suppressed, and the occurrence of seizure of the bearing can be prevented.
In addition, when the straightness exceeds 0.008 or the parallelism exceeds 0.015, the contact with the outer ring portion is less stable.

  The reason for defining the bus bar shape using the reference ring is as follows. The shell-type outer ring is thin and inevitably deformed by heat treatment etc. during the manufacturing process, but the deformation is corrected by press-fitting into a housing with the correct dimensional accuracy so that it has the accuracy to demonstrate its original function. Designed to. Therefore, when measuring the accuracy of the shell type roller bearing, it is possible to measure the correct accuracy at the time of using the shell type outer ring by pressing it in the reference ring.

As a width direction range in which the rollers roll on the rolling surface of the shell type outer ring, a width direction range L2 that defines straightness and parallelism of the bus bar shape is L2 ≧ 0.8 with respect to the roller length L. × L
And
Further, the distance L1 from one flange surface of the outer ring to the width direction range L2 is:
0.8 ≦ L1 ≦ 2 (unit: mm).

  In this invention, the length of the portion that is the shear surface near the central portion in the longitudinal direction of the column portion may be 60% or more of the length of the needle roller. If the length of the shear surface near the longitudinal center of the cage column is short and the contact length between the needle roller and the cage shear surface is short, the behavior of the needle roller cannot be suppressed. As described above, when the length in the longitudinal direction of the shear surface in the vicinity of the central portion in the longitudinal direction of the cage column is 60% or more of the length of the needle roller, the needle roller and the flat surface are flat. The contact portion of the shear surface becomes longer, and the behavior of the needle roller can be stabilized accordingly.

The connecting rod assembly according to the present invention is formed on a connecting projection formed by laminating plate-shaped divided connecting rod parts each having a large end portion, a small end portion, and a rod portion, and press-worked on the rod portion, and on the back surface of the projection. A laminated connecting rod in which adjacent divided connecting rod parts are coupled to each other, an outer ring, a plurality of rollers, and the plurality of rollers are held by meshing with the recessed portion or meshing with a through hole formed separately from the protrusion. A connecting rod assembly comprising a cage type roller bearing having a cage and the outer ring being press-fitted into a large or small end bearing fitting hole in the laminated connecting rod,
The retainer of the shell-type roller bearing is press-molded in a cross-sectional shape in which an intermediate portion in the width direction is recessed toward the inner diameter side than both end portions, and pockets are provided at a plurality of locations in the circumferential direction, and portions between adjacent pockets The portion of the shear surface on the inner surface along the longitudinal direction of the pocket is a flat shape without a raised portion that locally protrudes in a part of the pocket longitudinal direction,
In the shell type outer ring, the bus bar shape of the rolling surface is straightness: 0.008 or less and parallelism: 0.015 or less with reference to the inner diameter surface of the reference ring into which the shell type outer ring is press-fitted. It is characterized by that.

According to this configuration, in addition to the above-described effects obtained by the shell type roller bearing, the following effects can be obtained. In other words, even if the inner diameter surface of the large and small ends of each of the divided connecting rod components constituting the laminated connecting rod is inclined by pressing, the inclination of the inner diameter surface of the large and small ends of the laminated connecting rod can be eliminated. it can. Therefore, even if the outer ring of the shell-type roller bearing is press-fitted into the large end and the small end, the press-fitted outer ring is not inclined. For this reason, a press-punched product can be adopted for each divided connecting rod part, and post-processing such as grinding and polishing of the large end portion and the small end portion becomes unnecessary. Further, the laminated divided connecting rod parts are joined to each other by meshing with a coupling projection pressed on the rod portion and a recess formed on the back surface of the projection, or with a through-hole formed separately from the projection. Because they are joined, they can be joined firmly. Since the laminated divided connecting rod parts are joined at the rod portion by the protrusions and the recesses, the bending strength and buckling strength of the rod portion are improved. Since the protrusions and the recesses on the back surface are formed by press working, they can be easily formed.
In this way, a connecting rod with a laminated structure of inexpensive press-punched products, a connecting rod that can press-fit a shell-type outer ring without tilting while using a shell-type bearing with an inexpensive press cage, and lateral running with reduced roller skew In combination with a bearing capable of preventing the occurrence of the above, a connecting rod assembly which is totally inexpensive and excellent in various performances can be obtained.

  A shell type roller bearing for a laminated connecting rod according to the present invention includes a plate-like divided connecting rod component having a large end portion, a small end portion, and a rod portion, respectively, and a connecting projection formed by pressing the rod portion, Laminated connecting rods that connect adjacent divided connecting rod parts to each other by meshing with a recess formed on the back surface of the projection or with a through hole formed separately from the projection, an outer ring, a plurality of rollers, and a plurality of these A shell-type roller bearing in a connecting rod assembly comprising a cage-type roller bearing having a retainer for holding the roller and the outer ring being press-fitted into a large or small bearing fitting hole in the laminated connecting rod, The cage is press-molded into a cross-sectional shape in which an intermediate portion in the width direction is recessed toward the inner diameter side than both end portions, and is provided at a plurality of locations in the circumferential direction. A portion between adjacent pockets provided with a ket is a pillar portion, and a portion of the shear surface on the inner surface along the longitudinal direction of the pocket is a raised portion that locally protrudes in a part of the pocket longitudinal direction. The shell-type outer ring has a generatrix shape in the width direction range in which the rollers roll on the rolling surface with reference to the inner diameter surface of the reference ring into which the shell-type outer ring is press-fitted. Since straightness: 0.008 or less and parallelism: 0.015 or less, the roller skew is suppressed while adopting a simple press cage that is used for laminated connecting rods and can be manufactured at low cost. The occurrence of lateral running of the bearing can be prevented.

  The connecting rod assembly according to the present invention is formed on a connecting projection formed by laminating plate-shaped divided connecting rod parts each having a large end portion, a small end portion, and a rod portion, and press-worked on the rod portion, and on the back surface of the projection. A laminated connecting rod in which adjacent divided connecting rod parts are coupled to each other, an outer ring, a plurality of rollers, and the plurality of rollers are held by meshing with the recessed portion or meshing with a through hole formed separately from the protrusion. A connecting rod assembly comprising a shell type roller bearing having a cage and the outer ring being press-fitted into a large or small end bearing fitting hole in the laminated connecting rod, wherein the cage of the shell type roller bearing comprises: The intermediate part in the width direction is press-molded into a cross-sectional shape that is recessed toward the inner diameter side from both end parts, and pockets are provided at multiple locations in the circumferential direction. The portion between the adjacent pockets becomes a pillar portion, and the portion of the shear surface on the inner surface along the longitudinal direction of the pocket has a flat shape without a raised portion that locally protrudes in a part of the pocket longitudinal direction. And the shell-type outer ring has a generatrix in the width direction range where the roller rolls on the rolling surface with reference to the inner diameter surface of the reference ring into which the shell-type outer ring is press-fitted, and the straightness: Since it is 0.008 or less and the parallelism is 0.015 or less, in addition to the effects of the above-described shell-type roller bearing, a connecting rod assembly can be easily and inexpensively manufactured, and the bearing mounted on the large end or the small end can be manufactured. The effect that inclination can be avoided is acquired. In addition, the divided connecting rod parts can be firmly connected to each other, and there is no fear of scattering, and the bending strength and the buckling strength can be improved. Therefore, both the connecting rod and the bearing are a connecting rod assembly which is comprehensively inexpensive and excellent in various performances.

  An embodiment of the present invention will be described with reference to FIGS. 1A and 1B show a cross-sectional view and a front view of a connecting rod assembly provided with a shell roller bearing for laminated connecting rods of this embodiment. This connecting rod assembly is used in, for example, a two-cycle engine, particularly a small engine, and includes a laminated connecting rod 1 and a shell-type roller bearing 4 fitted to the large end 2 and the small end 3 of the laminated connecting rod 1. Become. The laminated connecting rod 1 is obtained by laminating and integrating a plurality of (here, four) divided connecting rod parts 1A to 1D each having a large end portion 1a, a small end portion 1b, and a rod portion 1c.

  The divided connecting rod parts 1A to 1D are configured such that the projection 5 and the recess 5a formed by pressing provided at the same plane position are engaged with each other, or the projection 5 and the through hole 6 are engaged with each other, and the engagement is brought into a press-fit state. Are connected. That is, the divided connecting rod parts 1 </ b> A to 1 </ b> D are coupled to each other by clamping with the protrusion 5 and the recess 5 a or the through hole 6. The protrusion 5 has a back surface serving as the recess 5a, and the intermediate split connecting rod parts 1B and 1C are stacked in the recess 5a on the back surface of the protrusion 5 and the protrusion 5 of the split connecting rod parts 1A and 1B on the back surface side. Mesh. The split connecting rod 1D on the outermost layer on the protruding side of the protrusion 5 has the through hole 6 formed therein. These protrusions 5 or through holes 6 may be provided at one or more places in the rod portion 1c, but in this embodiment, they are provided at three places separated from each other in the longitudinal direction of the rod.

  Each of the divided connecting rod parts 1A to 1D is a flat plate-like part having the same outer peripheral shape, and bearing fitting holes 7 and 8 are formed in the large end portion 1a and the small end portion 1b thereof. The shell-type roller bearings 4 are fitted in the respective bearing fitting holes 7 and 8 in a press-fitted state. The shell type roller bearings 4 fitted to the large end 2 and the small end 3 of the laminated connecting rod 1 have the same configuration except for different dimensions.

  As shown in an enlarged cross-sectional view in FIG. 2, the shell type roller bearing 4 includes a plurality of press-processed cylindrical shell-type outer rings 11 having both ends and an inner surface 11 c of the shell-type outer ring 11. Needle rollers 12 and a retainer 13 that rotatably holds these needle rollers 12. Both end portions of the shell type outer ring 11 are flange portions 11a and 11b directed to the inner diameter side.

  The shell type outer ring 11 is manufactured as shown in FIG. That is, a blank punching process in which a circular blank is punched from a steel strip as a material, a deep drawing process in which the blank is deep-drawn into a cylindrical shape with a bottom, and the bottom of the cylindrical material serves as a flange 11a at one end. It is manufactured through a bottom punching process for punching leaving a part, a heat treatment process (not shown), and an edge bending process for bending the flange 11b on the opening end side after inserting the rollers 12 held in the cage.

  In FIG. 2, the cage 13 is formed in a cylindrical shape, and pockets 14 for holding the needle rollers 12 are provided at a plurality of locations in the circumferential direction. The cage 13 is composed of ring-shaped portions 13a at both ends and column portions 13b formed between the pockets 14 adjacent in the circumferential direction and connected to the ring-shaped portions 13a on both sides. The ring-shaped portions 13a on both sides of the cage 13 are arranged to face the inner diameter side portions of the flange portions 11a and 11b of the shell type outer ring 11. The cage 13 is made of a steel plate and is manufactured by pressing.

  The cage 13 is manufactured as follows by the process schematically shown in the flowchart in FIG. First, the steel strip 20 is press-molded into a cross-sectional shape in which the intermediate portion in the width direction is recessed from both end portions. Press-molded into a so-called V-form. A punch (not shown) is inserted into the pressed steel strip 20 from the concave surface side, and the pocket 14 is pulled out. That is, the punch is inserted by inserting a punch from the side that becomes the outer diameter side after being formed into a cylindrical shape. The semi-finished product thus formed is cut into a band having a predetermined length in the next cutting step. In the next bending step, the cut band-shaped semi-finished product is bent into a cylindrical shape. In the next welding step, both end portions in the circumferential direction of the bent semi-finished product are joined by welding to form a ring shape. Finally, soft nitriding or carburizing and quenching is performed on the ring-shaped cage 13 by a heat treatment process.

As described above, since the cage 13 is formed in a cylindrical shape to insert a punch from the outer diameter side to perform pocket removal, as described in the description of the conventional example, Has a shear surface on the punch insertion side and a fracture surface on the opposite side of the punch insertion side. Therefore, in the state of being bent as described above, a shear surface 14a is generated on the outer peripheral side of the inner surface of the pocket 14 and a fracture surface 14b is generated on the inner peripheral side as shown in FIG.
In this case, since the conventional product was press-molded into a V-form after punching out the pocket in the state of a strip steel, a raised portion was generated on the inner surface of the flat pocket when the pocket was removed. First, the V-form is molded and then pocketed. Therefore, as shown in FIG. 8 later, the inner surface of the pocket 14 is completed with a flat surface along the shape of the punch.

FIG. 6 shows a sectional view of the shell type roller bearing 4 with the shaft 10 inserted therein, and FIG. 7 shows an enlarged half sectional view of the pocket 13 in the cage 13 in the cage width direction. In FIG. 7, the needle roller 12 is indicated by a two-dot chain line. A portion located on the PCD (FIG. 6) in the arrangement of the needle rollers 12 on the inner surface along the longitudinal direction of the pocket 14 is indicated by a line segment 15 in FIG. 7. As described above, on the inner surface along the longitudinal direction of the pocket 14 in FIG. 7, the outer peripheral portion indicated by the white portion is the shear surface 14 a, and the inner peripheral portion indicated by the broken hatch portion is the fracture surface 14 b. is there. That is, the portion (line segment 15) located on the PCD of the arrangement of the needle rollers 12 on the inner surface along the longitudinal direction of the pocket 14 becomes the shear surface 14a in the vicinity of the central portion in the longitudinal direction of the column portion 13b, At both ends in the longitudinal direction, the fracture surface 14b is formed.
In this embodiment, the length in the longitudinal direction of the shearing surface 14a in the vicinity of the central portion in the longitudinal direction of the column portion 13b, that is, the recessed shape portion 13ba is set to 60% or more of the length of the needle roller 12. Further, the V form is adjusted so that the axial length W from the end face in the pocket to the intersection of the shear surface 14a and the PCD upper line segment 15 is 20% or less of the roller length.

  FIG. 8 shows a measurement result on the line 15 of FIG. 7 of the cage 13 in the embodiment manufactured with the configuration of FIG. As can be seen from the figure, the length in the longitudinal direction of the shear surface 14a in the vicinity of the central portion in the longitudinal direction of the retainer column portion 13b, that is, in the recessed portion 13ba, is 60% or more of the length of the needle roller 12. The fracture surface 14b is provided near the root portion. The portion of the shear surface 14a has a flat shape without a raised portion that protrudes locally in a part of the pocket longitudinal direction. Further, the axial length W (FIG. 7) from the end face in the pocket to the intersection of the shear surface 14a and the PCD upper line segment 15 is 20% or less of the roller length.

As shown in FIG. 9, the shell-shaped outer ring 11 has the needle rollers 12 on the rolling surface 11c of the outer ring 11 rolling on the basis of the inner diameter surface A of the reference ring 40 (that is, the surface into which the outer ring 11 is press-fitted). The bus shape of the moving width direction range L2 is straightness: 0.008 or less and parallelism: 0.015 or less. Both straightness and roundness are measured at four equally spaced positions on the circumference as shown in FIG.
In this case, as the width direction range L2 in which the needle rollers roll on the rolling surface 11a of the shell type outer ring 11, the width direction range L2 that defines the straightness and parallelism of the bus bar shape is set to the roller length L. For L2 ≧ 0.8 × L
And
Further, the distance L1 from one flange surface of the shell-type outer ring 11, that is, the inner surface of the flange 11a formed by bottoming, to the width direction range L2 is:
0.8 ≦ L1 ≦ 2 (unit: mm).

According to the shell type roller bearing 4 having this configuration, as described above, the cage 13 has a raised portion in which the portion of the shear surface 14a on the inner surface along the longitudinal direction of the pocket 14 locally projects in a part of the pocket longitudinal direction. It has a flat shape with no part. Therefore, the needle roller 12 comes into contact with the shearing surface 14 a on the flat inner surface of the pocket of the cage 13. Therefore, for example, when this shell type roller bearing is operated by being incorporated in the connecting rod assembly of FIG. 1 of a two-cycle engine, the needle roller 12 and the cage 13 come into stable contact.
The shell-type outer ring 11 has a generatrix shape in the width direction range L2 in which the rollers roll on the rolling surface 11c with reference to the inner diameter surface of the reference ring 40 into which the outer ring 11 is press-fitted, and the straightness: 0.008. In the following, since the flat rolling surface has a parallelism of 0.015 or less, the contact between the outer ring 11 and the needle roller 12 is also stabilized.
For these reasons, the skew of the needle rollers 12 is suppressed, and the lateral running of the bearing in the thrust direction is eliminated. Thereby, the contact of the width surface of the shell type outer ring 11 and the engine counterpart component is suppressed, and seizure of the shell type roller bearing 4 can be prevented.

  The reason for defining the bus bar shape using the reference ring 40 is as follows. The shell-type outer ring 11 is thin and inevitably deformed by heat treatment or the like during the manufacturing process. However, the deformation is corrected by press-fitting into a housing having the correct dimensional accuracy, and the original function can be exerted. Designed as such. Therefore, when the accuracy of the shell type roller bearing 4 is measured, it is possible to measure the correct accuracy when the shell type outer ring 11 is used by being pressed into the reference ring 40. The inner diameter dimension of the reference ring 40 is set for each bearing.

  Also in the cage 13 configured as described above, the length of the shear surface 14a in the vicinity of the central portion in the longitudinal direction of the cage column portion 13b is short, and the contact portion length between the needle roller 12 and the shear surface 13b of the cage 13 is short. Then, the behavior of the needle roller 12 cannot be sufficiently suppressed. However, in this embodiment, the length in the longitudinal direction of the shear surface 14a in the vicinity of the central portion in the longitudinal direction of the retainer column portion 13b, that is, the recessed portion 13ba, is set to 60% or more of the length of the needle roller 12. In addition, the axial length W from the end face in the pocket to the intersection of the shear surface 14a and the PCD upper line segment 15 is 20% or less of the roller length. Therefore, the contact part of the needle roller 12 and the shearing surface 14a becomes long, and the behavior of the needle roller 12 can be stabilized accordingly.

The following Table 1 shows the connecting rod of a two-cycle engine, the shell type roller bearing 4 of the above embodiment, the conventional shell type roller bearing 34 shown in FIGS. 13 to 16, and the shell type roller bearing of the above embodiment. 4, a sample shell type roller bearing in which the length in the longitudinal direction of the shearing surface 14a in the vicinity of the central portion in the longitudinal direction of the cage pillar 13b is shortened (50% of the length of the needle roller 12) is incorporated and seized. The result of having performed the confirmation test (1st image sticking confirmation test) is shown. In Table 1, a sample shell type roller bearing is shown as Sample A.
For the example product and the sample A, the rollers 12 and 32 on the rolling surfaces 11a and 31a of the shell type outer rings 11 and 31 with respect to the inner diameter surface of the reference ring 40 into which the shell type outer rings 11 and 31 are press-fitted. The shape of the generatrix in the width direction range L2 in which the roller rolls is a flat rolling surface shape with straightness: 0.008 or less and parallelism: 0.015 or less.
The width direction range L2 is L2 ≧ 0.8 × L with respect to the roller length L.
And
Further, the distance L1 from one flange surface of the outer rings 11 and 31 to the width direction range L2 is:
0.8 ≦ L1 ≦ 2 (unit: mm).

The test conditions for the first seizure confirmation test are as follows.
Mixing ratio: Gasoline 50: Lubricating oil 1
Operation pattern: Full throttle Operation time: 2 hours or until seizure

  From the test results of Table 1, seizure due to side running occurred in 7 out of 10 bearings in the conventional product and 5 out of 10 bearings in the sample A, whereas the shell type of the above embodiment It was found that all ten roller bearings 4 were not seized.

The measuring method of the bus bar shape of the shell type outer rings 11 and 31 may be either the conventional measuring method or the new measuring method described below, but the new measuring method is preferable, and the new measuring method is adopted in the above test examples. .
[Conventional measurement method]
Conventionally, the bus bar shape is measured as shown in FIG. That is, before measuring the bus bar shape, the reference ring 40 is leveled and the bus bar shape is measured by the stylus 41.
In the case of this measuring method, the inclination of the measured range with respect to the reference ring 40 can be determined, but the position where the needle roller 12 rolls cannot be clearly determined, and the bus bar shape of the range in which the roller rolls is measured. Can not.

[New measurement method]
In the case of the measurement range and measurement value regulation as shown in FIG. 9, as shown in FIG. 11 (A), the bus of the reference ring 40 is measured as the reference line, and as it is as shown in FIG. 11 (B). The bus bar of the collar part 11a and the rolling surface 11c is measured continuously. The reference ring 40 shown in FIG. 11 has a concentricity between the inner diameter surface and the outer diameter surface, and the inner diameter surface may be used as a reference as long as measurement is possible on the inner diameter surface of the reference ring 40.
A schematic diagram example of the measurement results is shown in FIG.
For the measurement, a contour shape measuring machine (for example, Mitutoyo Corporation CV3000) is used.

Table 2 shows the results of the seizure test according to the shape of the rolling surface. The test conditions are the same as those in the first seizure confirmation test. The measurement position and length of the bus bar shape were measured at the same part in all the bearings.
As for the cage 13, the example product is manufactured as described with reference to FIG. 3B in the above embodiment, so that the portion of the shear surface 14 a on the inner surface along the longitudinal direction of the pocket 14 is in the pocket longitudinal direction. It is a flat shape that does not have a raised part that locally protrudes in part. As described in the section of [Problems to be Solved by the Invention], the conventional cage is formed into a V-form after pocket removal, and is partly in the pocket longitudinal direction as shown in FIG. A raised part that protrudes locally occurs. The raised amount is about 30 μm.

  According to the results of Table 2, there is no seizure when the parallelism and straightness are within the standards as in the examples. Further, in the conventional product 1, the parallelism was out of specification and seizure occurred. In the conventional product 2, the straightness was out of specification and seizure occurred. In the conventional product 3 that is out of specification for both parallelism and straightness, seizure occurs at 7/10, which is inappropriate as a countermeasure against seizure.

  Moreover, in the said embodiment, the shell type roller bearing 4 of the said structure is inserted in the bearing fitting holes 7 and 8 of the big end 2 or the small end 3 (In the embodiment, both the big end 2 and the small end 3) in the laminated connecting rod 1. Since the connecting rod assembly is press-fitted, the following effects can be obtained in addition to the above-described effects by the shell type roller bearing 4.

That is, even if the inner end surfaces of the large end portion 1a and the small end portion 1b of each of the divided connecting rod components 1A to 1D constituting the laminated connecting rod 1 are inclined by pressing, the large end 2 and the small end 3 of the laminated connecting rod 1 are provided. It is possible to eliminate the inclination of the inner diameter surface. For example, when each of the divided connecting rod parts 1A to 1D is an ordinary press punched product, the inner end surface of the large end portion 1a or the small end portion 1b is inclined due to the fracture surface, Therefore, the level difference between the shear plane and the fractured surface is reduced, and the fractured surfaces are dispersed and arranged by lamination. For this reason, the inclination of the internal diameter surface of the large end 2 and the small end 3 can also be avoided as a whole of the laminated connecting rod 1. Therefore, even if the outer ring 11 of the shell-type roller bearing 4 is press-fitted into the large end 2 and the small end 3, the press-fitted outer ring 11 is not inclined. For this reason, a press punched product can be adopted for each of the divided connecting rod parts 1A to 1D, and post-processing such as grinding and polishing of the large end portion 1a and the small end portion 1b becomes unnecessary.
In addition, the laminated divided connecting rod parts 1A to 1D are formed separately from the engagement between the coupling protrusion 5 pressed on the rod portion 1c and the recess 5a formed on the back surface of the protrusion 5 or the protrusion 5 described above. Since they are coupled to each other by meshing with the through-holes 6, they can be firmly joined. Since the laminated divided connecting rod parts 1A to 1D are joined at the rod portion 1c by the protrusion 5 and the concave portion 5a, the bending strength and the buckling strength of the rod portion 1c are improved. Since the protrusion 5 and the concave portion 5a on the back surface thereof are formed by pressing, they can be easily formed.

  Thus, the connecting rod 1 that can press-fit the shell-type outer ring 11 without tilting while using the connecting rod 1 having a laminated structure of an inexpensive press-punched product and the shell-type bearing 4 using the inexpensive press retainer 13, and the needle roller 12 is combined with the bearing 4 that can prevent the occurrence of side running by suppressing the skew of 12, so that a connecting rod assembly that is inexpensive and excellent in various performances can be obtained.

(A) and (B) are a sectional view and a front view of a connecting rod assembly including a shell roller bearing for laminated connecting rods according to an embodiment of the present invention. It is an expanded sectional view of the shell type roller bearing in the same connecting rod assembly. (A), (B) is a flowchart of the manufacturing process of the shell type outer ring | wheel of the same bearing, and a holder | retainer, respectively. It is explanatory drawing of the bending process in the manufacturing process. It is explanatory drawing which shows the punch insertion side of a holder | retainer. It is sectional drawing which cut the shell type roller bearing in the width direction. It is the half part expanded sectional view which carried out the cross section of the retainer in the width direction. It is a figure which shows the surface shape measurement result of the part located on the needle roller pitch circle diameter of the pocket internal peripheral surface in the holder. (A), (B) is the longitudinal cross-sectional view and cross-sectional view which show the relationship between a reference | standard ring and a shell type outer ring | wheel, (C) is the elements on larger scale of the same figure (A). It is explanatory drawing of the conventional measuring method. It is explanatory drawing of the measurement method of a novel proposal. It is explanatory drawing of a measurement result example. It is sectional drawing which cut the conventional shell type roller bearing in the width direction. It is explanatory drawing which shows the punch insertion side of the holder | retainer in the same shell type roller bearing. It is the half part expanded sectional view which carried out the cross section of the same holder in the width direction. It is a figure which shows the surface shape measurement result of the part located on the needle roller pitch circle diameter of the pocket internal peripheral surface in the holder.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Laminated connecting rod 1a ... Large end part 1b ... Small end part 1c ... Rod part 1A-1D ... Divided connecting rod component 2 ... Large end 3 ... Small end 4 ... Shell type roller bearing 5 ... Protrusion 5a ... Recess 6 ... Through-hole 7 , 8 ... Bearing fitting hole 11 ... Shell type outer ring 11c ... Rolling surface 12 ... Needle roller 13 ... Cage 13b ... Column part 13ba ... Recessed shape part 14 ... Pocket 14a ... Shear surface 14b ... Fracture surface 40 ... Reference ring

Claims (4)

The plate-shaped divided connecting rod parts each having a large end portion, a small end portion, and a rod portion are laminated, and the coupling protrusion pressed on the rod portion and the recess formed on the rear surface of the protrusion are engaged, or A laminated connecting rod in which adjacent divided connecting rod parts are connected to each other by meshing with a through-hole formed separately from the projection, a shell-type outer ring, a plurality of rollers, and a cage for holding the plurality of rollers are provided. The outer ring is a shell type roller bearing in a connecting rod assembly comprising a shell type roller bearing press-fitted into a large or small bearing fitting hole in the laminated connecting rod,
The retainer is press-molded in a cross-sectional shape in which the intermediate portion in the width direction is recessed toward the inner diameter side than both end portions, pockets are provided at a plurality of locations in the circumferential direction, and a portion between adjacent pockets becomes a column portion The portion of the shear surface on the inner surface along the longitudinal direction of the pocket is a flat shape without a raised portion that locally projects in a part of the pocket longitudinal direction,
The shell-type outer ring has a generatrix shape in a width direction range where the roller rolls on the rolling surface with reference to the inner diameter surface of the reference ring into which the shell-type outer ring is press-fitted, and the straightness: 0.008 or less And a parallelism: 0.015 or less, a shell-type roller bearing for laminated connecting rods.   2. The shell-type roller bearing for a laminated connecting rod according to claim 1, wherein a length of a portion of the column portion which is a shear surface near a central portion in the longitudinal direction is 60% or more of the length of the roller. In Claim 1 or Claim 2, as the width direction range in which the roller rolls on the rolling surface of the shell type outer ring, the width direction range L2 that defines straightness and parallelism of the bus bar shape is a roller length. For L L2 ≧ 0.8 × L
Shell roller bearings for laminated connecting rods. The plate-shaped divided connecting rod parts each having a large end portion, a small end portion, and a rod portion are laminated, and the coupling protrusion pressed on the rod portion and the recess formed on the rear surface of the protrusion are engaged, or A laminated connecting rod in which adjacent divided connecting rod parts are connected to each other by meshing with a through-hole formed separately from the projection, a shell-type outer ring, a plurality of rollers, and a cage for holding the plurality of rollers are provided. The outer ring is a connecting rod assembly comprising a shell-type roller bearing press-fitted into a large or small bearing fitting hole in the laminated connecting rod,
The retainer of the shell-type roller bearing is press-molded in a cross-sectional shape in which an intermediate portion in the width direction is recessed toward the inner diameter side than both end portions, and pockets are provided at a plurality of locations in the circumferential direction, and portions between adjacent pockets The part of the shear surface on the inner surface along the longitudinal direction of the pocket is a flat shape without a raised portion that locally projects in a part of the pocket longitudinal direction,
In the shell type outer ring, the bus bar shape of the rolling surface is straightness: 0.008 or less and parallelism: 0.015 or less with reference to the inner diameter surface of the reference ring into which the shell type outer ring is press-fitted. A connecting rod assembly characterized by that.

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