JP2007170562A - 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 capable of preventing occurrence of lateral running by suppressing skewing of a roller and to provide a connecting rod assembly. <P>SOLUTION: This roller bearing 4 constitutes the connecting rod assembly by press-fitting into bearing fitting holes 7, 8 at a large end 2 or a small end 3 in the laminated connecting rod 1. A cage 13 of the shell type roller bearing 4 is constituted in such a way that its cross section is molded into such a shape that an intermediate part in the direction of width is recessed on an inside diameter side more than both end parts by press working, a part between pockets 14 and 14 being adjacent to a plurality of sections in the circumferential direction is a column part 13b, and a part positioned on diameter PCD of a pitch circle of needle-like roller arrangement on an inner face along the longitudinal direction of the pocket 14 becomes a shear plane 14a in the vicinity of a central part in the longitudinal direction of the column part 13b and becomes a fractured face 14b in a root part. A shell type outer ring 11 has a shape of generating line in the direction of width in which a roller 12 on a rolling face rolls having straightness of 0.008 or less and parallelism of 0.015 or less by using an inside diameter face of a reference ring in which the outer ring 11 is press-fitted as reference. <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, A plate-shaped split connecting rod part having a rod part is laminated, and a coupling protrusion pressed on the rod part and a recess formed on the back surface of the protrusion engage 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 rod parts are stacked together is fixed so that adjacent divided rod parts are coupled to each other by meshing with a hole (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, if each divided connecting rod part is a normal press-punched product, the inner divided surface of the large end part and the small end part is inclined due to the fracture surface in each divided connecting rod part. Therefore, 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. 14 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 ends 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. 14, the needle is positioned at the radial position near the PCD (pitch circle diameter of the needle roller arrangement) where the behavior of the needle roller 32 is most stable. 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 in the above-described connecting rod assembly for a two-cycle engine, contact between the width surface of the shell-type outer ring 31 and the engine counterpart surface occurs due to the lateral running of the bearing in the thrust direction. However, heat generation and image sticking 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. 15, the punch 33 is inserted from the inner diameter side in a state of being formed into a cylindrical shape. A shear surface 34a is generated on the inner diameter side and a fracture surface 34b is generated on the outer 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. 16 shows 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. 14) is inserted is indicated by a line segment 35, and the position where the line segment 35 corresponding to the PCD position overlaps the shearing surface 34a, that is, A portion where the needle roller 32 contacts the shearing surface 34a is indicated by a line segment 36. As can be seen from FIG. 16, the needle rollers 32 come into contact with the both ends of the pocket of the cage 33 and the shearing surfaces 34a in the vicinity of both ends of the column 33b, so that the skew of the needle rollers 32 in an ideal form during operation. Should be able to suppress.

However, according to FIG. 17 which 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. 16, the shear surface 34a (line in FIG. 16) at both longitudinal ends of the pocket inner surface. The portion 36) is not flat. In FIG. 17, a cross section of the needle roller 32 is also shown overlapping the surface shape of the pocket inner surface. From this measurement result, it can be seen that the chamfered portions of the end portions of the needle rollers 32 are in contact with the non-flat shear surface 34a at both longitudinal ends of the pocket inner surface.
That is, both ends in the longitudinal direction on the inner surface of the pocket correspond to the corners of the pocket 34, but it is difficult to pull out the pocket corners at a right angle by press working, and the shape must be rounded. As a result, the shear surface 34a at both ends in the longitudinal direction on the pocket inner surface is inclined so as to approach the needle roller 32 toward the end side. As a result, the chamfered portion of the needle roller 32 comes into contact with the shearing surface 34a having an unstable inclination on the inner surface of the pocket, so that the needle roller 32 is likely to be skewed, and the bearing is provided in the thrust direction. Run sideways and burn-in occurs.

  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, A laminated connecting rod in which adjacent divided connecting rod parts are connected 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 needle rollers, and The shell-type roller bearing in a connecting rod assembly having a retainer for holding the plurality of rollers and a shell-type roller bearing in which the outer ring is press-fitted into a large or small bearing fitting hole in the laminated connecting rod. The retainer is press-molded into a cross-sectional shape in which an intermediate portion in the width direction is recessed toward the inner diameter side with respect to both end portions, and a plurality of portions in the circumferential direction are formed. A portion between adjacent pockets is a column portion, and a portion located on the pitch circle diameter of the needle roller arrangement on the inner surface along the longitudinal direction of the pocket is a portion of the column portion. The shear surface is near the center in the longitudinal direction, and the fracture surface is at the root.The outer ring of the shell type rolls the roller on the rolling surface on the basis of the inner diameter surface of the reference ring into which the outer ring of the shell type is press-fitted. It is characterized in that the generatrix shape of the moving range in the width direction is straightness: 0.008 or less and parallelism: 0.015 or less.

According to this configuration, the portion of the press retainer of the shell type roller bearing located on the pitch circle diameter of the needle roller arrangement on the inner surface along the longitudinal direction of the pocket is not near the central portion in the longitudinal direction of the column portion. It becomes a cross section, and it is made to become a torn surface in a root part. For this reason, for example, when operated by being incorporated in a connecting rod assembly of a two-cycle engine, the needle roller and the cage come into stable contact with a shear surface that is a flat surface near the center in the longitudinal direction of the cage column. Will do.
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 stability of contact with the outer ring portion decreases.

  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.

  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.

Further, in this invention, 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 relative to the roller length L. L2 ≧ 0.8 × L
Is preferable.

  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 by meshing with a recessed portion or meshing with a through hole formed separately from the projection, an outer ring, a plurality of needle rollers, and the plurality of rollers. A connecting rod assembly comprising a shell-type roller bearing having a holding holder and the outer ring being press-fitted into a large or small bearing fitting hole in the laminated connecting rod, wherein the cage of the shell-type roller bearing However, 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 column portion, and the portion located on the pitch circle diameter of the needle roller arrangement on the inner surface along the longitudinal direction of the pocket is the central portion in the longitudinal direction of the column portion. The shell-shaped outer ring has a shear surface in the vicinity and a fractured surface at the root, and the width direction in which the roller rolls on the rolling surface is based on the inner diameter surface of the reference ring into which the shell-type outer ring is press-fitted. The generatrix shape of the range is characterized by straightness: 0.008 or less and parallelism: 0.015 or less.

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, A laminated connecting rod in which adjacent divided connecting rod parts are connected 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 needle rollers, and The shell-type roller bearing in a connecting rod assembly having a retainer for holding the plurality of rollers and a shell-type roller bearing in which the outer ring is press-fitted into a large or small bearing fitting hole in the laminated connecting rod. The retainer is press-molded into a cross-sectional shape in which an intermediate portion in the width direction is recessed toward the inner diameter side with respect to both end portions, and a plurality of portions in the circumferential direction are formed. A portion between adjacent pockets is a column portion, and a portion located on the pitch circle diameter of the needle roller arrangement on the inner surface along the longitudinal direction of the pocket is a portion of the column portion. The shear surface is near the center in the longitudinal direction, and the fracture surface is at the root.The outer ring of the shell type rolls the roller on the rolling surface on the basis of the inner diameter surface of the reference ring into which the outer ring of the shell type is press-fitted. Because the bus shape of the moving width direction range is straightness: 0.008 or less and parallelism: 0.015 or less, a simple press holder that is used for laminated connecting rods and can be manufactured at low cost is adopted. However, it is possible to prevent the occurrence of lateral running of the bearing by suppressing roller skew.

  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 by meshing with a recessed portion or meshing with a through hole formed separately from the projection, an outer ring, a plurality of needle rollers, and the plurality of rollers. A connecting rod assembly comprising a shell-type roller bearing having a holding holder and the outer ring being press-fitted into a large or small bearing fitting hole in the laminated connecting rod, wherein the cage of the shell-type roller bearing However, 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 column portion, and the portion located on the pitch circle diameter of the needle roller arrangement on the inner surface along the longitudinal direction of the pocket is the central portion in the longitudinal direction of the column portion. The shell-shaped outer ring has a shear surface in the vicinity and a fractured surface in the root portion. .008 or less and parallelism: 0.015 or less, in addition to the effects of the shell type roller bearing described above, the connecting rod assembly can be manufactured easily and inexpensively, and the inclination of the bearing attached to the large end or the small end Can be obtained. 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.

  A first 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 sectional view in FIG. 2, the shell type roller bearing 4 includes a cylindrical shell type outer ring 11 with a press-processed both side including a drawing step, and a roller formed of an inner diameter surface of the shell type outer ring 11. It consists of a plurality of needle rollers 12 arranged along the running surface 11c, and a cage 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 pocket 14 is punched into the steel strip 20 by a pocket punching process using a punch. In the next molding step, the column portion 13b (FIG. 2) sandwiched between the adjacent pockets 14 is press-molded into a cross-sectional shape in which an intermediate portion in the longitudinal direction (intermediate portion in the width direction of the cage 13) is recessed from both end portions. In this case, in the pocket punching process, the side where the punch is inserted is press-molded. 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 as shown in FIG.

  In this case, it is bent and formed into a cylindrical shape so that the concave shape portion 13ba of the intermediate portion in the longitudinal direction of the column portion 13b is recessed toward the inner diameter side, that is, as shown in FIG. To do. As described in the description of the conventional example, on the inner surface of the pocket 14, a shear surface is generated on the punch insertion side, and a fracture surface is generated 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 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.

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 radial length of the shear surface 14a is set so that the axial length W from the end surface in the pocket 14 to the intersection of the shear surface 14a and the PCD upper line segment 15 is 20% or less of the roller length. Adjust.

As shown in FIG. 10, the shell-type 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, a distance L1 from one flange surface of the shell type outer ring 11, that is, the inner surface of the flange portion 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, the portion (line segment 15) of the retainer 13 located on the PCD of the arrangement of the needle rollers 12 on the inner surface along the longitudinal direction of the pocket 14 as described above. In the vicinity of the central portion in the longitudinal direction of the column portion 13b, the shear surface 14a is formed, and at the root portion, that is, both longitudinal ends, the fracture surface 14b is formed. Therefore, the needle roller 12 and the cage 13 are in contact with each other at the shear surface 14a near the longitudinal center of the cage column 13b during operation, and the cage column having an inclination generated in the pocket removal process. The needle roller 12 does not contact the fracture surface 14b at the root of the portion 13b. Therefore, the needle roller 12 can stably contact the cage 13, the skew of the needle roller 12 is suppressed, and the lateral running of the bearing in the thrust direction is eliminated.
Further, the shell-type outer ring 11 has a generatrix shape in the width direction range L2 in which the roller 12 rolls 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. Since the flat rolling surface shape is 008 or less and the parallelism is 0.015 or less, the contact between the outer ring 11 and the needle rollers 12 is also stabilized by this.
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, even if this shell type roller bearing 4 is used in a connecting rod assembly for a two-cycle engine as shown in FIG. 1, the contact between the width surface of the shell type outer ring 11 and the engine counterpart component is suppressed, and the shell type roller bearing 4. The occurrence of seizure 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. Therefore, the contact portion between 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. 14 to 17, 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 the 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 11c and 31c of the shell type outer rings 11 and 31 are based on the inner diameter surface of the reference ring 40 into which the shell type outer rings 11 and 31 are press-fitted. The generatrix of the width direction range L2 to roll was made into the flat rolling surface shape which becomes 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 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.

  8 shows the results of measuring the surface shape of the inner surface of the pocket at the position corresponding to the PCD equivalent line segment 15 of the arrangement of the needle rollers 12 in the shell type roller bearing 4 of the embodiment, and FIG. The surface shape measurement result of the pocket inner surface in the position corresponding to PCD of the needle roller arrangement in the bearing is shown. 8 and 9 also show a cross section of the needle roller 12 so as to overlap the surface shape of the pocket inner surface. According to FIG. 8, in the shell-type roller bearing 4 of the embodiment, a flat shear surface having a length of 60% or more of the length of the needle roller 12 is secured at the longitudinal center portion of the cage column portion 13b, and the root It can be seen that the vicinity has a fracture surface. On the other hand, in FIG. 9 which shows the measurement result of the shell-type roller bearing of sample A, the flat shearing surface secured at the center in the longitudinal direction of the cage column 13b is 50 times the length of the needle roller 12. It turns out that it is about%.

  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.

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. 10, as shown in FIG. 12 (A), the bus of the reference ring 40 is measured as the reference line, and as it is as shown in FIG. 12 (B). The bus bar of the collar part 11a and the rolling surface 11c is measured continuously. The reference ring 40 shown in FIG. 12 is one in which the coaxiality between the inner diameter surface and the outer diameter surface is ensured, 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, both the example products and the conventional products 1 to 3 are manufactured as described in FIG. 3B in the above embodiment, so that the needle roller array on the inner surface along the longitudinal direction of the pocket 14 is provided. The portion located on the pitch circle diameter PCD is a sheared surface near the center in the longitudinal direction of the column portion 13b and a fracture surface at the root portion.

  According to the results of Table 2, there is no seizure when the parallelism and straightness are within the standards as in the examples. Moreover, 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 a rate of 7/10, which is inappropriate as a countermeasure against seizure.

  From the results of Tables 1 and 2, the portion of the retainer 13 on the pitch circle diameter PCD of the roller arrangement on the inner surface along the longitudinal direction of the pocket 14 which is a constituent element of the present invention is the longitudinal length of the column portion 13b. The width direction in which the roller 12 rolls on the rolling surface 11c, which satisfies the configuration that the shear surface is near the center in the direction and the fracture surface is at the root, and the shell-type outer ring 11 is also a constituent of the present invention. In the case where the generatrix shape of the range satisfies the requirements of straightness: 0.008 or less and parallelism: 0.015 or less, none of the seizures are generated and excellent as a countermeasure against seizure. It can be seen that any of the outer ring 11 and the outer ring 11 does not satisfy the above requirement, and seizure occurs, which is inappropriate as a seizure countermeasure.

  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 into the circumferential 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. 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 | retainer of a sample. (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 to the circumferential 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 coupled to each other by meshing with a through hole formed separately from the protrusion, an outer ring, a plurality of needle rollers, and a cage for holding the plurality of rollers. The shell-type roller bearing in a connecting rod assembly comprising a shell-type roller bearing in which the outer ring is 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 located on the pitch circle diameter of the needle roller array on the inner surface along the longitudinal direction of the pocket is a shear surface near the longitudinal center of the column portion, and a fracture surface at the root portion, 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 a parallelism: 0.015 or less, a shell type roller bearing for laminated connecting rods.   The shell-type roller bearing for a laminated connecting rod according to claim 1, wherein a length of a portion of the pillar portion which is a shear surface near a longitudinal center portion is 60% or more of a length of the needle 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 coupled to each other by meshing with a through hole formed separately from the protrusion, an outer ring, a plurality of needle rollers, and a cage for holding the plurality of rollers. A connecting rod assembly comprising a shell-type roller bearing in which the outer ring is 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 Is a portion that is located on the pitch circle diameter of the needle roller arrangement on the inner surface along the longitudinal direction of the pocket, the shear surface in the vicinity of the central portion in the longitudinal direction of the column portion, and at the root portion The shell-type outer ring has a fracture surface, and the bus bar shape of the rolling surface is straightness: 0.008 or less and parallelism 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 being 0.015 or less.

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