阅读说明：本技术 凸轮从动件装置 (Cam follower device ) 是由 山口晋弘 外山正基 于 2018-07-10 设计创作，主要内容包括：这种凸轮从动件装置包括：具有一对对置侧壁的轴承保持构件,侧壁之间设有空间,且相对于设置在凸轮轴上的凸轮布置轴承保持构件；支撑轴,插入到同轴地设置在这对对置侧壁中的每一个侧壁中的插入孔中；外环,插有该支撑轴,被设置在这对对置侧壁之间,且面对凸轮；内环,由支撑轴的外周表面形成；和多个滚子,设置在外环与内环之间的环形间隙中。(Such a cam follower arrangement comprises: a bearing holding member having a pair of opposed side walls with a space provided therebetween, the bearing holding member being arranged with respect to a cam provided on a camshaft; a support shaft inserted into an insertion hole coaxially provided in each of the pair of opposing side walls; an outer ring, interposed with the support shaft, disposed between the pair of opposing side walls and facing the cam; an inner ring formed by an outer circumferential surface of the support shaft; and a plurality of rollers disposed in an annular gap between the outer ring and the inner ring.)

1. A cam follower arrangement, comprising:

a bearing holding member including a pair of opposing side walls that are provided in a state of being spaced apart from each other and that are provided with respect to a cam provided on a camshaft;

a support shaft inserted into each insertion hole coaxially provided in the pair of opposing side walls;

an outer ring that is disposed between the pair of opposing side walls in a state where the support shaft is inserted, and that faces the cam;

an inner ring formed on an outer circumferential surface of the support shaft; and

a plurality of rollers disposed in an annular gap between the outer ring and the inner ring,

wherein the cam follower means is configured to oscillate in correspondence with the movement of the cam,

wherein drop-off preventing structures that prevent the support shaft from dropping off from the bearing holding member are provided at one end side and the other end side of the support shaft, and

wherein the support shaft is rotatable about an axis of the support shaft relative to the bearing retaining member.

2. The cam follower device of claim 1,

wherein the drop-off preventing structure at the one end side of the support shaft includes a collar portion having an outer diameter larger than a diameter of the insertion hole and sandwiching one of the pair of opposing side walls, the collar portion being provided on a side opposite to the outer ring.

3. The cam follower device of claim 1,

wherein the drop-off prevention structure at the one end side of the support shaft includes:

a groove portion provided on an outer peripheral surface of the one end side of the support shaft so as to be continuous in a circumferential direction; and

the insertion hole is set to have a diameter larger than an outer diameter of the groove portion and smaller than an outer diameter of the support shaft, and corresponds to the groove portion.

4. The cam follower device of claim 1,

wherein the drop-off prevention structure at the one end side and the other end side of the support shaft includes:

an open portion that is open in a portion of each of the insertion holes in the pair of opposing side walls on the cam side, and that has a width smaller than a diameter of the insertion hole; and

a groove portion provided on each of the outer peripheral surfaces of the one end side and the other end side of the support shaft so as to be continuous in a circumferential direction and have an outer diameter larger than a width of the open portion and smaller than a diameter of the insertion hole.

5. The cam follower means of claim 2 or 3,

wherein the drop-off preventing structure on the other end side of the support shaft is a structure including a caulking portion having an outer diameter larger than a diameter of the insertion hole through which the support shaft is inserted; is a structure in which a fixing groove portion is provided on an outer peripheral surface of the other end side of the support shaft so as to be continuous in the circumferential direction and a C-ring or an O-ring is fitted into the fixing groove portion; or a structure in which a male screw portion is provided on the other end of the support shaft and a fastening member including a female screw portion corresponding to the male screw portion is screwed together.

Technical Field

One aspect of the present invention relates to a cam follower arrangement.

Background

For example, patent document 1 describes a cam follower device 150 of the related art shown in fig. 11 to 13. As shown in fig. 11, a cam follower device 150 of the related art disclosed in patent document 1 includes a rocker arm 130, an outer ring 120, a support shaft 122, and a plurality of rollers 124. As shown in fig. 12 (fig. 12 is a sectional view taken along line XII-XII in fig. 11), the rocker arm 130 includes a pair of opposed side walls 138, and an insertion hole 132 into which the support shaft 122 is inserted is coaxially provided in each of the opposed side walls 138. The outer ring 120 is disposed between the pair of opposing side walls 138, and the support shaft 122 is inserted into the insertion hole 132 of each of the pair of opposing side walls 138 and the outer ring 120. In a space between the outer peripheral surface 121 of the support shaft 122 and the inner peripheral surface of the outer ring 120, a plurality of rollers 124 are rotatably provided around the entire periphery, and the outer ring 120 is rotatable relative to the support shaft 122. Both end portions of the support shaft 122 are fixed to the opposite side walls 138 by caulking portions K in the insertion holes 132 of the opposite side walls 138, so that the support shaft 122 does not fall off the rocker arms 130, and the support shaft 122 cannot rotate about the axis relative to the opposite side walls 138.

Patent document 2 describes a cam follower device in which an inner ring is provided between a support shaft and a roller, as compared with the cam follower device described in patent document 1. The inner ring is fixed to the support shaft to be integral with the support shaft, and the support shaft is attached to the rocker arm to be rotatable relative to the rocker arm (opposite side wall).

CITATION LIST

Patent document

Patent document 1: JP-A-2014-169627

Patent document 2: JP-A-2013-167236

Disclosure of Invention

Technical problem

As shown in fig. 11, in the cam follower device 150 described in patent document 1, the cam 110 rotates while being in contact with the outer ring 120. Accordingly, the outer ring 120 rotates with the rotation of the cam 110 in contact therewith. When the eccentric portion 110C of the cam 110 contacts the outer ring 120, the cam 110 depresses the cam follower arrangement 150 without rotating the outer ring 120. This state is shown in the enlarged view of fig. 13. At this time, as shown in fig. 13, the depressing force F is transmitted from the cam 110 to the support shaft 122 via the outer ring 120 and the rollers 124. At this time, since the outer ring 120 rotates with the rotation of the cam 110, the region of the outer ring 120 that receives the depression force F is at various positions in the circumferential direction, and is not concentrated at one position. Since the plurality of rollers 124 rotate about the support shaft 122 while rotating with the rotation of the outer ring 120, the pressing force F is not concentrated on one specific roller 124. However, since the support shaft 122 is fixed in the insertion hole 132 of the rocker arm 130 and does not rotate, the downward pressure F concentrates in the region Z (load circle) shown in fig. 13. That is, in the circumferential direction of the support shaft 122, only the region Z located at a specific position receives the depression force F (repeated load) at a time. For this reason, fatigue peeling may occur in the region Z of the support shaft 122, and the service life of the cam follower device may be shortened.

In patent document 2, since the support shaft integrated with the inner ring is rotatable with respect to the rocker arm, the inner ring and the support shaft also rotate in accordance with the rotation of the outer ring or the roller. Therefore, the depression force from the cam is not concentrated at one portion of the support shaft in the circumferential direction. Therefore, it is considered that the service life thereof can be longer than that of the cam follower device described in cited document 1. However, the number of parts is increased (an inner ring is added) as compared with patent document 1, and this is not preferable because the structure thereof becomes complicated.

Aspects of the present invention have been made in view of the above circumstances, and an object of the present invention is to provide a cam follower device which has a simple structure and is capable of preventing rolling fatigue peeling from occurring on a support shaft, thereby improving the service life thereof.

Solution to the problem

In order to solve the above problem, in a first aspect, a cam follower device includes: a bearing holding member including a pair of opposing side walls that are provided in a state of being spaced apart from each other and that are provided with respect to a cam provided on a camshaft; a support shaft inserted into each insertion hole coaxially provided in the pair of opposing side walls; an outer ring that is disposed between the pair of opposing side walls in a state where the support shaft is inserted, and that faces the cam; an inner ring formed on an outer circumferential surface of the support shaft; and a plurality of rollers disposed in an annular gap between the outer ring and the inner ring. The cam follower means is configured to oscillate in correspondence with the movement of the cam. Drop-off prevention structures that prevent the support shaft from dropping off from the bearing holding member are provided at one end side and the other end side of the support shaft. The support shaft is rotatable about an axis of the support shaft relative to the bearing retaining member.

In a second aspect, the drop-preventing structure at the one end side of the support shaft includes a collar portion having an outer diameter larger than a diameter of the insertion hole and sandwiching one of the pair of opposing side walls, the collar portion being provided on a side opposite to the outer ring.

In a third aspect, the drop-preventing structure at the one end side of the support shaft includes: a groove portion provided on an outer peripheral surface of the one end side of the support shaft so as to be continuous in a circumferential direction; and the insertion hole, the insertion hole is set to have a diameter larger than the outer diameter of the groove portion and smaller than the outer diameter of the support shaft, and the insertion hole corresponds to the groove portion.

In a fourth aspect, the drop preventing structure at the one end side and the other end side of the support shaft includes: an open portion that is open in a portion of each of the insertion holes in the pair of opposing side walls on the cam side, and that has a width smaller than a diameter of the insertion hole; and a groove portion provided on each of the outer peripheral surfaces of the one end side and the other end side of the support shaft so as to be continuous in a circumferential direction and having an outer diameter larger than a width of the open portion and smaller than a diameter of the insertion hole.

In a fifth aspect, the drop-preventing structure on the other end side of the support shaft is a structure including a caulking portion having an outer diameter larger than a diameter of the insertion hole through which the support shaft is inserted; is a structure in which a fixing groove portion is provided on an outer peripheral surface of the other end side of the support shaft so as to be continuous in the circumferential direction and a C-ring or an O-ring is fitted into the fixing groove portion; or a structure in which a male screw portion is provided on the other end of the support shaft and a fastening member including a female screw portion corresponding to the male screw portion is screwed together.

Advantageous effects of the invention

According to the first to fourth aspects, the support shaft is rotatable about the axis of the support shaft with respect to the bearing holding member. Therefore, the load circle on the outer circumferential surface of the support shaft is not limited to a specific range (same region) with respect to the rotation of the cam, and is not limited to one position. Therefore, rolling fatigue peeling due to repeated roller loads can be prevented from occurring at one position (load circle) of the support shaft, and the service life of the cam follower device can be improved. Since the support shaft is used as the inner ring, the structure thereof can be simple.

According to a fifth aspect, in the cam follower device according to the second or third aspect, the drop-off prevention structure at the other end side of the support shaft can be relatively easily realized with a relatively simple structure.

Drawings

Fig. 1 is a perspective view showing the overall configuration of a cam follower device.

Fig. 2 illustrates the operation of the cam follower means.

Fig. 3 is a sectional view taken along line III-III of fig. 2, and shows the structure of the cam follower device according to the first embodiment.

Fig. 4 shows the rotation of the cam and the rotation of the support shaft in the cam follower device according to the present application.

Fig. 5 is a sectional view showing the structure of a cam follower device according to a second embodiment, and corresponds to fig. 3.

Fig. 6 is a sectional view showing the structure of a cam follower device according to a third embodiment, and corresponds to fig. 3.

Fig. 7 is a sectional view showing the structure of a cam follower device according to a fourth embodiment, and corresponds to fig. 3.

Fig. 8 is a sectional view showing the structure of a cam follower device according to a fifth embodiment, and corresponds to fig. 3.

Fig. 9 is an exploded perspective view showing the overall configuration of a cam follower device according to a sixth embodiment.

Fig. 10 is a sectional view showing the structure of a cam follower device according to a sixth embodiment, and corresponds to fig. 3.

Fig. 11 shows an example of a cam follower device in the related art.

Fig. 12 is a sectional view taken along line XII-XII of fig. 11, and shows the structure of a cam follower device of the related art.

Fig. 13 shows that the pressing force from the cam is concentrated at one position of the supporting shaft in the cam follower device of the related art.

Detailed Description

Embodiments (first to sixth embodiments) of the present invention will be described below with reference to the drawings. Each of the cam follower devices shown in the first to sixth embodiments includes a drop-off prevention structure at one end side and the other end side of the support shaft, which prevents the support shaft from dropping off from the rocker arm (corresponding to the bearing holding member). The support shaft is rotatable about an axis of the support shaft with respect to the rocker arm (corresponding to the bearing holding member).

Integral construction of cam follower device 50 (fig. 1 and 2)

First, an overview of the configuration and operation of the cam follower device will be described with reference to fig. 1 and 2. As shown in fig. 1, the cam follower means 50 includes the rocker arm 30, the outer ring 20, and the support shaft 22. As shown in fig. 2, the valve mechanism (the valve stem end 17, the spring 14, and the valve 18) and the lash adjuster 11 are provided on both longitudinal direction ends of the rocker arm 30 to support the ends. The valve 18 is provided in the cylinder head 90 in an openable and closable manner, and the lash adjuster 11 is fixed to the cylinder head 90. In the drawings showing the X, Y and Z axes, the X, Y and Z axes are orthogonal to each other. The Y-axis direction refers to the longitudinal direction of the swing arm 30. In fig. 2, the direction from the valve rod end 17 toward the lash adjuster 11 is the Y direction, and the X-axis direction refers to a direction parallel to the center axis of the cam 10.

As shown in fig. 2, the rocker arms 30 are provided on both longitudinal direction ends of the rocker arms 30, respectively: a recessed lash adjuster receiver 34, the lash adjuster receiver 34 being configured to receive the tip of the lash adjuster 11; and a stem end receiver 36, the stem end receiver 36 receiving the stem end 17.

In fig. 2, the lash adjuster 11 abuts against the lash adjuster receiver 34, and the valve stem end 17 abuts against the valve stem end receiver 36. The outer circumferential surface of the cam 10 abuts against the outer circumferential surface of the outer ring 20. Thus, the cam follower arrangement 50 is supported at the three positions described above with respect to the cylinder head 90. In the cam follower device 50, the outer peripheral surface 21 of the outer ring 20 and the outer peripheral surface 10A of the cam 10 face each other.

As shown in fig. 2, when the eccentric portion 10C abuts against the outer ring 20 due to the rotation of the camshaft 12, the cam 10 presses the abutted outer ring 20 down toward a certain side of the cylinder head 90. Therefore, the cam follower device 50 rotates (swings) about the lash adjuster receiver 34 serving as a center (fulcrum), and presses down the valve stem end 17 toward the cylinder head 90 to open the valve 18. When the camshaft 12 rotates, the base circumferential portion 10B of the cam 10 abuts against the outer ring 20, the stem end 17 swings due to the urging force of the spring 14, so as to be pressed back to the original position (the position where the valve 18 is closed), and the valve 18 is closed.

Structure and effect of cam follower device 50A according to first embodiment (fig. 3 and 4)

Next, a cam follower device 50A according to a first embodiment will be described with reference to fig. 3 and 4. Fig. 3 shows a cross section of a cam follower arrangement 50A according to a first embodiment. Cam follower arrangement 50A includes rocker arm 30, support shaft 22A, outer ring 20, and roller 24. Fig. 4 is an enlarged view showing a state (solid line) before the cam 10 presses down the outer ring 20 and a pressed state (two-dot chain line). In the first embodiment, the drop-off prevention structure at the one end side of the support shaft 22A includes the collar portion 26. The anti-drop structure on the other end side of the support shaft 22A includes a caulking portion Ka.

As shown in fig. 3, the rocker arm 30 includes a pair of opposing side walls 38, the pair of opposing side walls 38 being disposed in a spaced-apart state from each other, and the rocker arm 30 is disposed with respect to the cam 10 (see fig. 2) provided on the camshaft 12. The insertion hole 32 is provided coaxially with each of the pair of opposed side walls 38. The support shaft 22A is inserted into each of the insertion holes 32 of the pair of opposed side walls 38. The outer ring 20 is disposed between a pair of opposite side walls 38 into which the support shaft 22A is inserted, and faces the cam 10. A plurality of rollers 24 are provided in an annular gap between the inner ring formed by the outer peripheral surface 21 of the support shaft 22A and the outer ring 20.

The diameter Da3 of the collar portion 26 is larger than the diameter Da2 of the insertion hole 32, and the collar portion 26 is disposed on one end side of the support shaft 22A (the collar portion 26 sandwiches the opposite side wall 38 and is disposed on the opposite side from the outer ring 20). The support shaft 22A is formed to have a caulking portion Ka at the other end side of the support shaft 22A to prevent the support shaft 22A from falling off the rocker arm 30. A gap La1 is provided between a wall surface of the opposite side wall 38 on a side not facing the outer ring 20 and a surface of the outer edge portion of the collar portion 26 facing the wall surface. The gap La2 is provided between the wall surface of the opposite side wall 38 on the side where the outer ring 20 is not provided and the surface of the outer edge portion of the caulking portion Ka facing the wall surface. The diameter Da2 of the insertion hole 32 is larger than the diameter Da1 of the support shaft 22A. Therefore, the support shaft 22A is rotatable about the axis of the support shaft 22A relative to the rocker arm 30.

As shown in fig. 4, for example, when the camshaft 12 rotates and the cam 10 rotates from the position indicated by the solid line to the position indicated by the two-dot chain line, the outer ring 20 is rotated by the cam 10 and the outer ring 20 is pressed down toward the cylinder head 90. Therefore, as shown in fig. 2, the rocker arm 30 rotates (swings) about the lash adjuster receiver 34 toward the cylinder head 90 to open the valve 18. The rollers 24 rotate as the outer ring 20 rotates. As described above, the support shaft 22A is rotatable with respect to the rocker arm 30.

As shown in fig. 4, since the support shaft 22A rotates relative to the rocker arm 30 (see fig. 2), the area a (load circle) of the support shaft 22A that receives the force pressing down the outer ring 20 from the cam 10 rotates about the axis of the support shaft 22A and moves (area a'). Therefore, the load circle on the outer circumferential surface 21 of the support shaft 22A is not limited to a specific range with respect to the rotation of the cam 10, and is not one position. Therefore, the same area on the outer peripheral surface 21 of the support shaft 22A does not always receive the load from the cam 10. That is, various regions in the circumferential direction of the support shaft 22A receive loads. Therefore, since the problem of fatigue peeling caused by repeated load reception of a specific portion (the same portion) of the support shaft 22A can be prevented, the service life of the cam follower device can be further improved.

Structure and effect of cam follower device 50B according to second embodiment (fig. 5)

Next, a cam follower device 50B according to a second embodiment will be described with reference to fig. 5. In the cam follower device 50B, the drop-off prevention structure on the other side of the support shaft 22B to prevent the support shaft 22B from dropping off by fitting a C-ring or an O-ring into a groove provided in the support shaft 22B, unlike the cam follower device 50A according to the first embodiment. Hereinafter, such differences will be mainly described.

In the cam follower device 50B according to the second embodiment, as shown in the sectional view of fig. 5, the drop-preventing structure provided at the one end side of the support shaft 22B is the collar portion 26 identical to that of the first embodiment, and therefore, the description of the collar portion 26 will be omitted. The drop-off preventing structure at the other end side of the support shaft 22B has a structure in which a fixing groove portion TB is provided on the outer peripheral surface of the support shaft 22B at the other end side so as to be continuous in the circumferential direction while a ring R (C-ring or O-ring) is fitted into the fixing groove portion TB.

The diameter Db4 of the fixing groove portion TB of the support shaft 22B is smaller than the hole diameter Db5 of the ring R. The diameter Db1 of the support shaft 22B is larger than the diameter Db5 and smaller than the diameter Db2 of the insertion hole 32. The diameter Db32 of the other end of the support shaft 22B is smaller than the inner diameter of the insertion hole 32 of the opposite side wall 38. The outer diameter of the ring R is larger than the diameter Db2 of the insertion hole 32.

The gap Lb1 is provided between a wall surface of the opposite side wall 38 on a side not facing the outer ring 20 and a surface of the outer edge portion of the collar portion 26 facing the wall surface. The gap Lb2 is provided between a wall surface of the opposite side wall 38 on a side not facing the outer ring 20 and a surface of the outer edge portion of the ring R facing the wall surface. Therefore, the support shaft 22B is rotatable about the axis of the support shaft 22B relative to the rocker arm 30. Therefore, similarly to the first embodiment, since the problem of fatigue peeling caused by repeated load reception of a specific portion (the same portion) of the support shaft 22B can be prevented, the service life of the cam follower device can be further improved.

Structure and effect of cam follower device 50C according to third embodiment (fig. 6)

Next, a cam follower device 50C according to a third embodiment will be described with reference to fig. 6. In the cam follower device 50C, the anti-drop structure on the other side of the support shaft 22C, which prevents the drop from the rocker arm 30, prevents the support shaft 22C from dropping by fastening a fastening member (e.g., a nut) to the support shaft 22C, unlike the cam follower device 50A according to the first embodiment. Hereinafter, such differences will be mainly described.

In the cam follower device 50C according to the third embodiment, as shown in the sectional view of fig. 6, the drop-preventing structure provided at the one end side of the support shaft 22C is the collar portion 26 identical to that of the first embodiment, and therefore, the description of the collar portion 26 will be omitted. The anti-drop structure at the other end side of the support shaft 22C has a structure in which a male screw portion 39 is provided on the other end of the support shaft 22C while a fastening member N (e.g., a nut) including a female screw portion corresponding to the male screw portion 39 is screwed together.

The dimension Dc3 of the outer shape of the fastening member N is larger than the diameter Dc2 of the insertion hole 32 by such an extent that the support shaft 22C does not slip out of the insertion hole 32. The diameter Dc1 of the support shaft 22C is smaller than the diameter Dc2 of the insertion hole 32.

The gap Lc1 is provided between a wall surface of the opposite side wall 38 on a side not facing the outer ring 20 and a surface of the outer edge portion of the collar portion 26 facing the wall surface. The gap Lc2 is provided between a wall surface of the opposite side wall 38 on a side not facing the outer ring 20 and a surface of the outer edge portion of the fastening member N facing the wall surface. Therefore, the support shaft 22C is rotatable about the axis of the support shaft 22C relative to the rocker arm 30. For screwing the fastening member N to the male screw portion 39, two fastening members N (double nuts) may be used. Therefore, the fastening member N can be prevented from coming off the male screw portion 39 while maintaining the gap Lc1 and the gap Lc 2. Therefore, similarly to the first embodiment, since the problem of fatigue peeling caused by repeated load reception of a specific portion (the same portion) of the support shaft 22C can be prevented, the service life of the cam follower device can be further improved.

Structure and effect of cam follower device 50F according to fourth embodiment (fig. 7)

Next, a cam follower device 50F according to a fourth embodiment will be described with reference to fig. 7. In the cam follower device 50F, the drop-off prevention structure on the other side of the support shaft 22F to prevent drop-off from the rocker arm 30F includes a groove portion TF provided on the entire periphery of the support shaft 22F and an insertion hole 32F2 corresponding to the groove portion TF, unlike the cam follower device 50A according to the first embodiment. Hereinafter, such differences will be mainly described.

In the cam follower device 50F according to the fourth embodiment, as shown in the sectional view of fig. 7, the drop-preventing structure provided at the one end side of the support shaft 22F is the collar portion 26 identical to that of the first embodiment, and therefore, the description of the collar portion 26 will be omitted. The drop-off preventing structure at the other end side of the support shaft 22F is a structure in which the collar portion 26F provided on the support shaft 22F is caught into the insertion hole 32F2 provided in the opposite side wall 38F2 to fit the groove portion TE into the insertion hole 32F 2.

As shown in fig. 7, the groove portion TF is provided on the outer peripheral surface 21F on the other end of the support shaft 22F so as to be continuous in the circumferential direction. The diameter Df4 of the groove TF is smaller than the diameter Df2 of the insertion hole 32F 2. The insertion hole 32F1 in the opposite side wall 38F1 has a diameter larger than the outer diameter Df3 of the collar portion 26F and larger than the outer diameter Df1 of the support shaft 22F. The diameter Df3 of the outer shape of the collar portion 26F is larger than the diameter Df2 of the insertion hole 32F2 to such an extent that the support shaft 22F does not slip out of the insertion hole 32F 2.

As shown in fig. 7, in order to correspond to the groove portion TF, the side surface of the collar portion 26F may be formed as a curved surface protruding in the radial direction over the entire circumference. The inner side wall of the rocker arm 30F provided with the insertion hole 32F2 may also be formed as a curved surface that protrudes in the radial direction over the entire circumference. The rocker arm 30F is made of a metal softer than the support shaft 22F. Therefore, the collar portion 26F is easily inserted into the insertion hole 32F2 of the opposite side wall 38F2 and is caught therein.

A gap Lf1 is provided between a wall surface of the opposite side wall 38F1 on a side not facing the outer ring 20 and a surface of the outer edge portion of the collar portion 26 facing the wall surface. A gap Lf2 is provided between a wall surface of the opposite side wall 38F2 on the side not facing the outer ring 20 and a surface of the outer edge portion of the collar portion 26F facing the wall surface. Therefore, the support shaft 22F is rotatable about the axis of the support shaft 22F with respect to the rocker arm 30F. Therefore, similarly to the first embodiment, since the problem of fatigue peeling caused by repeated load reception of a specific portion (the same portion) of the support shaft 22F can be prevented, the service life of the cam follower device can be further improved.

Structure and effect of cam follower device 50D according to fifth embodiment (fig. 8)

Next, a cam follower device 50D according to a fifth embodiment will be described with reference to fig. 8. In the cam follower device 50D, the drop-off preventing structure on the side of the support shaft 22D is not the collar portion 26, and includes the groove portion TD1 provided on the entire periphery of the support shaft 22D and the insertion hole 32D1 corresponding to the groove portion TD1, unlike the cam follower device 50B according to the second embodiment. Hereinafter, such differences will be mainly described. The anti-drop structure on the other end side of the support shaft 22D is the same as that of the second embodiment, and a description thereof will be omitted. One end side of the support shaft 22D has a structure in which a collar portion 26D1 provided on the support shaft 22D is caught into an insertion hole 32D1 provided in the opposite side wall 38D1 to fit the groove portion TD1 into the insertion hole 32D 1.

In the cam follower device 50D according to the fifth embodiment, as shown in the sectional view of fig. 8, a groove portion TD1 is provided on the outer peripheral surface 21D of the support shaft 22D on one end so as to be continuous in the circumferential direction. The diameter Dd41 of the groove portion TD1 is smaller than the diameter Dd21 of the insertion hole 32D 1.

The diameter Db22 of the insertion hole 32D2 in the opposing side wall 38D2 is larger than the outer diameter Dd31 of the collar portion 26D 1. The diameter Dd31 of the outer shape of the collar portion 26D1 is larger than the diameter Dd21 of the insertion hole 32D1 to such an extent that the support shaft 22D does not slip out of the insertion hole 32D 1.

As shown in fig. 8, in order to correspond to the groove portion TD1, the side surface of the collar portion 26D1 may be formed as a curved surface that protrudes in the radial direction over the entire circumference. The inner side wall of the rocker arm 30D provided with the insertion hole 32D1 may also be formed as a curved surface that protrudes in the radial direction over the entire circumference. The rocker arm 30D is made of a metal softer than the support shaft 22D. Therefore, the collar portion 26D1 is easily inserted into the insertion hole 32D1 of the opposite side wall 38D1 and is caught therein. Further, the support shaft 22D may have a shape symmetrical in the axial direction. That is, collar portion 26D1 and collar portion 26D2 may be identical, and groove portion TD1 and securing groove portion TD2 may be identical.

The gap Ld1 is provided between a wall surface of the opposite side wall 38D1 on the side not facing the outer ring 20 and a surface of the outer edge portion of the collar portion 26D1 facing the wall surface. The gap Ld2 is provided between a wall surface of the opposite side wall 38D2 on the side not facing the outer ring 20 and a surface of the outer edge portion of the ring R facing the wall surface. Therefore, the support shaft 22D is rotatable about the axis of the support shaft 22D with respect to the rocker arm 30D. Therefore, similarly to the second embodiment, since the problem of fatigue peeling caused by repeated load reception of a specific portion (the same portion) of the support shaft 22D can be prevented, the service life of the cam follower device can be further improved.

Structure and effect of cam follower device 50E according to sixth embodiment (fig. 9 and 10)

Next, a cam follower device 50E according to a sixth embodiment will be described with reference to fig. 9 and 10. In the cam follower device according to the sixth embodiment, the anti-drop structure on the one end side and the other end side of the support shaft 22E is the structure shown in fig. 9 and 10, which is different from the first to fifth embodiments. Fig. 9 is an exploded perspective view showing the overall configuration of a cam follower device 50E according to a sixth embodiment. Fig. 10 is a sectional view showing the structure of a cam follower device 50E according to a sixth embodiment. The cam follower device 50E includes: an insertion hole 32E, the insertion hole 32E being in the swing arm 30E; and a groove portion TE provided on each of the outer peripheral surfaces of the support shaft 22E on both end sides so as to be continuous in the circumferential direction, unlike the cam follower device 50A. Hereinafter, such differences will be mainly described.

As shown in the sectional view of fig. 10, the cam follower device 50E according to the sixth embodiment includes groove portions TE formed on the outer peripheries on both ends of the support shaft 22E so as to be continuous in the circumferential direction. The insertion hole 32E in each of the pair of opposed side walls 38E includes an open portion 33 (see fig. 9) that is open at a portion on the cam 10 side. The outer diameter De4 of the groove portion TE is larger than the width W of the open portion 33 (see fig. 9) to such an extent that the support shaft 22E does not slip out of the insertion hole 32E, and the outer diameter De4 of the groove portion TE is smaller than the diameter De2 of the insertion hole 32E. The rocker arm 30E is made of a metal softer than the support shaft 22E. Therefore, the collar portion 26E1 and the collar portion 26E2 are easily inserted into the insertion hole 32E of each of the pair of opposed side walls 38E and are caught therein.

A gap Le1 is provided between a wall surface of one opposed side wall 38E of the pair of opposed side walls 38E that face each other, which wall surface does not face one side of the outer ring 20, and a surface of an outer edge portion of the collar portion 26E1 that faces the wall surface. A gap Le2 is provided between a wall surface of the other opposing side wall 38E on the side not facing the outer ring 20 and a surface of the outer edge portion of the collar portion 26E2 facing the wall surface. Therefore, the support shaft 22E is rotatable about the axis of the support shaft 22E relative to the rocker arm 30E. Therefore, similarly to the first embodiment, since the problem of fatigue peeling caused by repeated load reception of a specific portion (the same portion) of the support shaft 22E can be prevented, the service life of the cam follower device can be further improved.

[ Effect of the present application ]

As described above, since the support shaft rotates relative to the rocker arm (bearing holding member) in the region (load circle) of the support shaft that receives the force from the cam that presses the outer ring down, the load circle is not limited to a specific range of rotation relative to the cam and is not one position. Therefore, not the same area serves as a load circle on the outer circumferential surface of the support shaft and receives a load from the cam, thus improving the service life of the support shaft in a manner of resisting rolling fatigue. In the case of a structure using a ring or a fastening member on one side, it is not necessary to rivet both end portions of the support shaft, and therefore normal quenching is sufficient for the outer peripheral surface of the support shaft (instead of high-frequency quenching), and thus there are advantages in production management and cost. Improving the service life in a manner resistant to rolling fatigue enables the width (whose hardness is to be regulated) on the outer peripheral surface of the support shaft (which is the rolling surface of the roller) to be reduced.

The cam follower device according to the present invention is not limited to the configuration and structure described in the present embodiment, and various modifications, additions, and deletions may be made without departing from the scope of the invention. In particular, the shape of the rocker arm (bearing holding member) constituting the cam follower means is not limited to the shape shown in the present embodiment, and may be any shape as long as the valve is appropriately opened and closed.

The present application is based on japanese patent application special application 2017-134561, filed on 7/10/2017, the contents of which are incorporated herein by reference.

List of reference numerals

10 cam

10A outer peripheral surface

10B radical circumferential part

10C eccentric part

11 lash adjuster

12 camshaft

14 spring

17 valve stem end

18 valve

20 outer ring

21. 21D, 21F outer peripheral surface

22. 22A, 22B support shaft

22C, 22D, 22E support shaft

22F supporting shaft

24 roller

26. 26D1, 26D2 lantern ring portion

26E1, 26E2, 26F collar portion

30. 30D, 30E, 30F rocker arm (bearing holding member)

32. 32D1 and 32D2 inserted into the hole

32E, 32F1 and 32F2 are inserted into the holes

33 open part

34 lash adjuster receiver

36 valve stem end receiver

38 opposite side walls

38D1, 38D2, 38E opposing sidewalls

38F1, 38F2 opposite side walls

39 male screw portion

50. 50A, 50B cam follower device

50C, 50D, 50E cam follower device

50F cam follower device

90 cylinder head

110 cam

110C eccentric part

120 outer ring

121 outer peripheral surface

122 support the shaft

130 rocking arm (bearing holding component)

132 insert into the hole

132 insert into the hole

138 opposite side walls

150 cam follower device

A. A', Z zone (load circle)

Da1, Da2, Da3 diameter

Db1, Db2, Db32, Db4, Db5 diameters

Dc1, Dc2 diameter

Dd1, Dd21, Dd31, Dd41 diameter

Df1, Df2, Df3, Df4 diameter

De2, De3, De4 diameters

Dc3 size

K. Ka riveting part

La1, La2 gap

Lb1, Lb2 gap

Lc1 and Lc2 gap

Ld1 and Ld2 gap

Le1, Le2 gap

Lf1 and Lf2 gap

N-fastening member

R ring

TD1, TE, TF groove part

TB, TD2 fixed groove part

Width W

F down force