JP4120358B2 - Shaft body for cam follower - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cam follower shaft used for a cam follower such as a rocker arm provided in a valve mechanism of an automobile, for example.
[0002]
[Prior art]
Generally, a cam follower such as a rocker arm is provided in a valve mechanism of an automobile. For example, the rocker arm has opposing walls in a body made of sheet metal press, and between these opposing walls, a roller is provided with needle rollers arranged in the circumferential direction on the inner peripheral surface, and the cam is in rolling contact with the outer peripheral surface. In this state, a shaft body (rocker shaft) is inserted through a support hole formed in each opposing wall.
[0003]
After passing to the support holes formed in each opposing wall as this shaft body, both end portions are crimped so that the outer peripheral surfaces of both end portions of the shaft body are crimped to the peripheral surface of the support hole, and non-rotating to the opposing wall (See, for example, Patent Document 1).
[0004]
FIG. 10 shows the cam follower 37 in a state in which both end portions of the shaft body 35 are caulked so as to expand in the radial direction and are supported by the opposing walls 36 and 36 in a non-rotating manner. In this cam follower 37, the outer peripheral surface center side portion which is the rolling surface of the needle roller 36 in the shaft body 35 is hardened to a predetermined hardness.
[0005]
By the way, the center side portion of the outer peripheral surface of the shaft body 35 is a rolling surface of the needle roller 36, and thus requires a predetermined hardness. However, as described above, the both ends of the shaft body 35 are caulked. The both ends of the shaft body 35 need to be kept in the hardness of the raw material. In order to make the outer peripheral surface center side part of the shaft body 35 have a predetermined hardness, a heat treatment step is performed. This heat treatment step is performed as follows.
[0006]
That is, as shown in FIG. 11, a shaft body 35 obtained by first cutting a wire into a predetermined length and cold forging (also referred to as a header) is sandwiched from both sides by a holding jig 30. Such a holding jig 30 has a bottom portion 32 that abuts on the end surface of the shaft body 35 and a cylindrical portion 33 that rises from the bottom portion 32 and covers the end portion of the outer peripheral surface of the shaft body 35. ing.
[0007]
An outer peripheral surface (not shown) of the shaft body 35 using a high-frequency generating coil (not shown) arranged so as to face the axial center of the shaft body 35 with the shaft body 35 held by such a holding jig 30. The outer peripheral surface central part) is heated to a predetermined temperature. Subsequently, the cooling solution 31 is applied (sprayed) to the shaft body 35, and the shaft body 35 is cooled to finish the induction hardening.
[0008]
By the way, at the time of induction hardening, the center portion of the shaft body 35 is heated by the high frequency coil, and then a predetermined surface hardness is obtained by applying the cooling solution 31, but the shaft body 35 is not disposed so as to face the high frequency coil. Quenching (or hardening treatment) is not performed on the end portion or the end surface of the outer peripheral surface.
[0009]
For this reason, the end of the outer peripheral surface of the shaft body 35 is maintained with the hardness of the raw material, and is crimped to the peripheral surface of the support hole of the support wall 36 by caulking both ends of the shaft body 35 when manufacturing the rocker arm. The shaft body 35 can be supported on the support wall 36 in a non-rotating manner.
[0010]
In the manufacturing process of the shaft body 35, when the induction hardening process as described above is completed, the holding jig 30 is moved from the shaft body 35 in the axial direction as shown in FIG. Supply to the place (stock).
[0011]
[Patent Document 1]
Japanese Utility Model Publication No. 6-25503 (see page 3, Fig. 4)
[0012]
[Problems to be solved by the invention]
As described above, the conventional shaft body 35 is subjected to induction hardening while being clamped by the holding jig 30 after being cold forged by cutting the wire into a predetermined length. By the way, when the cooling solution 31 is applied to the shaft body 35 after the shaft body 35 is overheated, a part of the cooling solution 31 is removed from the gap between the end of the shaft body 35 and the holding jig 30. 32 and the end face of the shaft body 35 may enter.
[0013]
As described above, when a part of the cooling solution 31 enters between the bottom 32 of the holding jig 30 and the end surface of the shaft body 35, the presence of the cooling solution 31 depends on the surface roughness of the end surface of the shaft body 35. Therefore, even if the holding jig 30 is moved from the shaft body 35 in the axial direction after induction hardening, the shaft body 35 is held. It is difficult to detach from the jig 30.
[0014]
Then, this invention aims at provision of the shaft body for cam followers which can solve the said subject.
[0015]
[Means for Solving the Problems]
The cam follower shaft body according to the present invention is quenched so that the outer peripheral surface of the central portion serving as the raceway surface of the roller has a predetermined hardness, and the circular insertion holes formed in each of the pair of opposing walls constituting the cam follower. together are inserted to pass, the end on the outer periphery of the circular through hole is caulked to press, to the each end face, a convex having an axial height in excess of amount of unevenness constituting the surface roughness The projections are formed in a virtual circle having a diameter that does not exceed 80% of the diameter of the end face with respect to the total area of the end face before caulking .
[0016]
According to this configuration, for example, the outer peripheral surface of both ends of the shaft body and the both end surfaces are covered and held by the holding jig, and the quenching process is performed so that the outer peripheral surface of the central portion that becomes the raceway surface of the roller has a predetermined hardness. When the holding jig is detached after the operation, the cam follower shaft can be easily removed from the holding jig by its own weight, for example, because an air layer exists between the holding jig and the shaft body end surface due to the presence of the convex portion. break away.
[0018]
As described above, since the convex part is formed in a virtual circle having a diameter not exceeding 80% of the diameter of the end face, when caulking each end part to press contact with the peripheral surface of each circular insertion hole, Space required for caulking work can be secured.
[0019]
Furthermore, the cam follower shaft body according to the present invention is obtained by cutting a steel wire with a predetermined axial length, cold forging, and covering and holding the outer peripheral surface and both end surfaces of both ends with a holding jig. In this state, both ends are inserted into circular insertion holes formed in a pair of opposed walls constituting the cam follower after the quenching is performed so that the outer peripheral surface of the central portion that becomes the raceway surface of the roller has a predetermined hardness. The outer peripheral surface of each end is pressed against the peripheral surface of the insertion hole by being caulked, and a convex portion having an axial height exceeding the amount of unevenness constituting the surface roughness is formed on each end surface, These convex portions are formed in a virtual circle having a diameter that does not exceed 80% of the diameter of the end face with respect to the entire area of the end face before caulking .
[0020]
According to the above configuration, when the holding jig is removed in the axial direction after quenching, an air layer exists between the holding jig and the end face of the shaft body due to the presence of the convex portion. For example, it is easily detached from the holding jig by its own weight and falls. For this reason, the situation of the line stop in the manufacturing process of the cam follower shaft is avoided, and the productivity is improved.
[0021]
In view of the withdrawal of the holding jig in the shaft manufacturing process, the diameter of the front Kitotsu portion is desirably set to a value not less than 50% of the diameter of the area equivalent for each end face total area .
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an example in which a cam follower shaft body (hereinafter simply referred to as a “shaft body”) according to an embodiment of the present invention is applied to a rocker arm will be described with reference to the drawings.
[0023]
1 is an exploded perspective view showing the entire rocker arm, FIG. 2 is a side view showing the usage state of the rocker arm, FIG. 3 is a cross-sectional view showing a caulking state of the shaft body, and FIGS. It is the single-piece | unit front view and single-piece | unit sectional drawing which show a shape.
[0024]
First, the overall structure of the illustrated rocker arm will be described. The rocker arm 1 is an end pivot type and is disposed at a predetermined location of an OHC valve mechanism in an engine as shown in FIGS. Reference numeral 2 denotes a cam disposed at a predetermined position of the engine valve mechanism, and the rocker arm 1 includes a roller 3 that a cam 2 contacts and rolls, and a pair of opposing walls 4 that face each other via the roller 3. , 5.
[0025]
A body 22 is formed by the opposing walls 4 and 5 and connecting walls 20 and 21 connecting the opposing walls 4 and 5 on both sides in the longitudinal direction. One connecting wall 20 is used as a pivot receiving portion with which the upper end portion of the lash adjuster 23 abuts, and the other connecting wall 21 is used as a valve stem fitting portion into which the upper end portion of the valve stem 24 is fitted.
[0026]
Support holes 6 and 7 are formed concentrically on the opposing walls 4 and 5 at longitudinal intermediate portions, respectively. The roller 3 is disposed between the opposing walls 4 and 5, and the roller 3 is formed with a shaft insertion hole 10 having a circular shape in a side view penetrating in the axial direction at a central portion in the radial direction.
[0027]
A shaft body (also referred to as a “rocker shaft”) 8 is passed through the support holes 6 and 7 so that the end portions 8a and 8b are supported in a non-rotating manner. The shaft body 8 is formed in a solid cross section.
[0028]
As shown in FIG. 3, the shaft body 8 is caulked so that the end portions 8 a and 8 b expand in the radial direction in a state where the shaft body 8 is inserted and passed through the support holes 6 and 7. 7 is pressed against the peripheral wall 7 and supported by the opposing walls 4 and 5 in a non-rotating manner. In FIG. 1, a caulking portion 8 c is shown on the end surface of the shaft body 8 with a virtual line.
[0029]
As shown in FIG. 4, recesses 14 a and 14 b are formed on both end faces 8 d and 8 e of the shaft body 8. These concave portions 14a and 14b have an axial depth h1 that exceeds the surface roughness of each end face 8d and 8e, for example, center line average roughness: Ra = 3.2 μm, and can be easily confirmed with the naked eye. Is possible. In the case of this embodiment, the axial depth h1 is formed to a value of 0.5 mm from a reference surface (for example, a virtual surface serving as a reference for the center line average roughness).
[0030]
The value of the axial depth h1 of the recesses 14a and 14b is a value that does not affect the caulking when the vicinity of the outer peripheral portion of the end surface of the shaft body 8 is caulked. That is, if the recesses 14a and 14b have the value of the axial depth h1, stable machining can be performed without causing a variation in caulking force.
[0031]
In particular, when the shaft body 8 is formed in a hollow cross section instead of forming the recesses 14a and 14b on both end faces 8d and 8e of the shaft body 8, the vicinity of the outer peripheral portion of the shaft body 8 is caulked. However, since the shaft body 8 is easily deformed to the inner diameter side, it is difficult to perform stable caulking. However, in this embodiment, the recesses 14a and 14b having a predetermined axial depth h1 are only formed on both end faces 8d and 8e of the shaft body 8, so that the above-described deformation does not occur and the Can be processed.
[0032]
Furthermore, each said recessed part 14a, 14b is formed so that a predetermined area may be occupied with the area projected to the axial direction with respect to the total area of each end surface 8d, 8e. That is, each of the recesses 14a and 14b is concentric with each of the end surfaces 8d and 8e, and the diameter D1 is 80% of the diameter D2 of the end surfaces 8d and 8e. Of course, this size is an area having a value exceeding 50% with respect to the total area of the respective end faces 8d and 8e.
[0033]
The reason why the diameter D1 of each recess 14a, 14b is set to 80% of the diameter D2 of each end face 8d, 8e is to prevent inconvenience in caulking during the production of the rocker arm 1. It is. That is, this size is sufficient to secure a sufficient space when caulking the vicinity of the outer peripheral portion of the shaft body 8.
[0034]
The roller 3 is externally mounted in the middle of the shaft 8 in the axial direction via a plurality of needle rollers 9 so as to be rotatable about the axis. These needle rollers 9 are arranged side by side in the circumferential direction of the peripheral surface along the peripheral surface portions of the support holes 6 and 7. Each needle roller 9 rolls around the shaft body 8 with the outer peripheral surface of the shaft body 8 and the peripheral surface of the shaft insertion hole 10 in the roller 3 as rolling surfaces.
[0035]
Reference numeral 13 in FIG. 1 indicates a roller holder. The roller holder 13 has a plurality of needle rollers 9 arranged side by side in the circumferential direction on the peripheral surface of the shaft insertion hole 10 in the roller 3. It is mounted in a cylindrical space 11 in a shaft insertion hole 10 formed by rollers 9.
[0036]
Next, a method for manufacturing the rocker arm 1 having the above configuration will be described. First, a single metal plate is punched into a predetermined shape, and then both support holes 6 and 7 are formed in a portion corresponding to the opposing walls 4 and 5 by punching using a processing tool (punch). Thereafter, the opposing walls 4 and 5 and the connecting walls 20 and 21 are formed by bending portions corresponding to the opposing walls 4 and 5. In the figure, the connecting wall 21 is fixed between the opposing walls 4 and 5, for example, by welding.
[0037]
Apart from the above, the shaft body 8 is manufactured in advance. Here, a manufacturing method of the shaft body 8 will be described. That is, a wire rod (not shown) is cut into a predetermined length to obtain a shaft body 8 (a shaft body planned member that becomes the shaft body 8 by performing a later process), and then each end face 8d on both sides of the shaft body 8 by cold forging. , 8e. At this time, for example, a roughness of 3.2 μm or less is generated as the center line average roughness (Ra) by cold forging.
[0038]
Further, at the time of this cold forging, at the same time, the recesses 14a and 14b are formed at the central portions of the end faces 8d and 8e of the shaft body 8 at a value deeper than the center line average roughness, for example, an axial depth h1 of 0.5 mm. Form.
[0039]
Subsequently, as shown in FIG. 5, the outer peripheral surface ends 8 a and 8 b of the shaft body 8 are clamped by the holding jig 30. At this time, the bottom portion 32 of the holding jig 30 abuts on the end surfaces 8 d and 8 e of the shaft body 8, and the cylindrical portion 33 of the holding jig 30 covers the outer peripheral surface end portions 8 a and 8 b of the shaft body 8.
[0040]
In this way, with the shaft body 8 held by the holding jig 30, the outer peripheral portion of the shaft body 8 on the center side of the outer peripheral surface is heated to a predetermined temperature using a high-frequency generating coil (not shown). Then, induction hardening is complete | finished by spraying the cooling solution 31 on the shaft body 8, and cooling. After induction hardening is completed, the holding jig 30 is detached from the shaft body 8 in the axial direction.
[0041]
Here, when the cooling solution 31 is applied to the shaft body 8, it is considered that the cooling solution 31 enters from the gap between the end portion of the shaft body 8 and the holding jig 30. In this case, depending on the surface roughness of the end face of the shaft body 8 when the wire rod is cut and cold forged, the presence of the cooling solution 31 that has entered between the bottom 32 of the holding jig 30 and the end face of the shaft body 8 exists. As a result, the end surface of the shaft body 8 is easily brought into close contact with the bottom 32 of the holding jig 30.
[0042]
Incidentally, as described above, the end faces 8d and 8e of the shaft body 8 have a center line average roughness (Ra) of 3.2 μm or less, and this surface roughness is determined by the holding jig 30. The degree of adhesion with the bottom portion 32 (bottom surface) is a high value.
[0043]
However, the end faces 8d and 8e of the shaft body 8 have a predetermined axial depth h1 exceeding the surface unevenness amount (average unevenness depth) forming the surface roughness of the end faces 8d and 8e as described above. The recesses 14a and 14b having an area exceeding 50% with respect to the total area of the end faces 8d and 8e are formed by cold forging.
[0044]
Therefore, an air layer is formed between the end faces 8d and 8e and the bottom 32 of the holding jig 30 due to the presence of the recesses 14a and 14b. Therefore, even if the cooling solution 31 has entered between the bottom 32 of the holding jig 30 and the end face of the shaft body 8, if the holding jig 30 is moved in the axial direction from the shaft body 8, the presence of the air layer is present. Thus, the shaft body 8 is easily detached from the holding jig 30 by its own weight. The manufacturing process of the shaft body 8 is thus completed.
[0045]
By the way, at the time of induction hardening as described above, since a high frequency coil is disposed opposite to the central portion of the shaft body 8, a predetermined surface hardness as a rolling surface of the needle roller 9 can be obtained by hardening. On the other hand, the outer peripheral surface end portions 8a and 8b and the end surfaces 8d and 8e of the shaft body 35 on which the high-frequency coil is not disposed facing each other are not quenched (or hardened). For this reason, this part is maintaining the hardness of raw material. In addition, the shaft body 8 which has finished the quenching process and is detached from the holding jig 30 is supplied to a predetermined place and stocked.
[0046]
On the other hand, as shown in FIG. 1, a plurality of needle rollers 9 are arranged in the circumferential direction on the circumferential surface of the shaft insertion hole 10 of the roller 3, and the shaft formed by the needle rollers 9. A roller holder 13 is attached to the cylindrical space 11 in the insertion hole 10 from one side in the axial direction, and each needle roller 9 is pressed against the peripheral surface of the shaft insertion hole 10 to hold the roller 3, the needle A set 14 of the roller 9 and the roller holder 13 is provided.
[0047]
Then, the assembly 14 is arranged at the longitudinal center position between the opposing walls 4 and 5, and the shaft body 8 is changed from the supporting hole 6 formed in the one opposing wall 4 to the supporting hole 7 formed in the other opposing wall 5. The roller holder 13 is pushed out, and the inner diameter side of the roller 3 is inserted so that the end 8b of the shaft body 8 is fitted into the support hole 7. Then, instead of the roller holder 13, the outer peripheral surface of the shaft body 8 comes into contact with the needle rollers 9.
[0048]
Thereafter, as shown in FIG. 3, the both ends 8a and 8b of the shaft body 8 having the raw material hardness are caulked so as to expand the diameter, and the outer peripheral surfaces of the both ends 8a and 8b are set to the support holes 6 respectively. , 7 and the shaft body 8 is assembled non-rotatingly.
[0049]
Each of the recesses 14a and 14b is concentric with the end surfaces 8d and 8e, and its diameter D1 is 80% of the diameter D2 of the end surfaces 8d and 8e. Even when caulking to expand the diameter of 8b, a sufficient space for the work can be secured. The rocker arm 1 is manufactured through the above steps.
[0050]
Thus, according to the embodiment of the present invention, when the holding jig 30 is separated from the shaft body 8 in the axial direction, the shaft body 8 can be easily removed from the holding jig 30 by its own weight due to the presence of the air layer as described above. Therefore, it is possible to avoid a state in which the shaft body 8 is not detached from the holding jig 30 as in the prior art. Therefore, it is possible to avoid a situation such as a line stop during the manufacturing process due to the shaft body 8 not being detached from the holding jig 30, and the productivity can be improved.
[0051]
The shape of the shaft body 8 of the present invention is not limited to the above embodiment. 6 to 8 show another embodiment of the shaft body 8. In the shaft body 8 shown in FIGS. 6A and 6B, the recesses 14a and 14b are formed in a truncated cone shape. In the shaft body 8 shown in FIGS. 7A and 7B, the recesses 14a and 14b are formed in an annular shape. In the shaft body 8 shown in FIGS. 8A and 8B, the concave portions 14a and 14b are formed in a partial spherical shape. Since the configuration of portions other than the shapes of the recesses 14a and 14b is the same as that of the above embodiment, the same reference numerals are given and the description thereof is omitted.
[0052]
In any of the embodiments shown in FIGS. 6 to 8, the recesses 14a and 14b are formed at the time of cold forging after cutting the wire during the manufacturing process of the shaft body 8, and have a center line average. In any of the embodiments shown in FIGS. 6 to 8, the recesses 14a and 14b have an axial depth h1 (for example, 5 mm) that exceeds the amount of unevenness that forms the surface roughness of the end faces 8d and 8e. . The recesses 14a and 14b are formed so as to occupy a predetermined ratio (for example, 50% or more) in the area projected in the axial direction with respect to the total area of the respective end surfaces 8d and 8e, and the recesses 14a and 14b The diameter D1 is formed so as to correspond to 80% of the diameter D2 of each end face 8d, 8e. In any of these embodiments, the same operational effects as those of the above embodiment can be obtained.
[0053]
The shaft body 8 shown in FIGS. 9A, 9B, 9C, and 9D is an example in which convex portions 40a and 40b are formed on the end faces 8d and 8e of the shaft body 8, respectively. Note that the convex portions 40a and 40b shown in FIG. 9 are exaggerated, and the height h2 is specifically 0.5 mm from the reference plane.
[0054]
In the shaft body 8 shown in FIG. 9A, the convex portions 40a and 40b are formed in a cylindrical shape. In the shaft body 8 shown in FIG. 9B, the convex portions 40a and 40b are formed in a truncated cone shape. In the shaft body 8 shown in FIG. 9C, the convex portions 40a and 40b are formed in a partial spherical shape. In the shaft body 8 shown in FIG. 9D, the convex portions 40a and 40b are formed in a triangular pyramid shape.
[0055]
In any of the embodiments shown in FIGS. 9A, 9B, 9C, and 9D, the protrusions 40a and 40b are formed at the time of cold forging after cutting the wire during the manufacturing process of the shaft body 8. Is. The protrusions 40a and 40b have an axial height that exceeds the amount of unevenness that forms the surface roughness of the end faces 8d and 8e, and are projected in the axial direction with respect to the entire area of the end faces 8d and 8e. It is formed so as to occupy a predetermined ratio (for example, 50% or more) by area, and the diameter D1 of each convex portion 40a, 40b is formed to correspond to 80% of the diameter D2 of each end face 8d, 8e. Since shapes other than the convex portions 40a and 40b are the same as those in the above-described embodiment, the same reference numerals are given and description thereof is omitted.
[0056]
In any of these embodiments, as in the case where the recesses 14 a and 14 b are formed, an air layer exists between the end faces 8 d and 8 e and the bottom 32 of the holding jig 30. Is separated from the shaft body 8 in the axial direction, even if the cooling solution 31 penetrates between the bottom 32 of the holding jig 30 and the end surfaces 8d and 8e of the shaft body 8 due to the presence of the air layer, the shaft The body 8 is easily detached from the holding jig 30 by its own weight. Thereby, the situation of the line stop in a manufacturing process can be avoided, and productivity can be made favorable.
[0057]
In each said embodiment, although one recessed part 14a, 14b or convex part 40a, 40b was formed in each end surface 8d, 8e of the shaft body 8, it is not limited to this. That is, if the area projected in the axial direction occupies a predetermined ratio, that is, 50% or more, and the diameter D1 is a concave or convex part that is within 80% of the diameter D2 of the end faces 8d and 8e, each end face 8d, A plurality may be formed on 8e.
[0058]
In each of the above embodiments, the concave portions 14a and 14b or the convex portions 40a and 40b are formed on both end surfaces 8d and 8e. However, the concave surface 14a (14b) is formed on one of the end surfaces 8d and 8e, and the end surfaces 8d and 8e are formed. Of these, the convex portion 40a (40b) may be formed on the other. Even in this case, an air layer exists between the end surfaces 8 d and 8 e and the bottom portion 32 of the holding jig 30, and the cooling solution 31 flows between the bottom portion 32 of the holding jig 30 and the end surface of the shaft body 8. Even when the holding jig 30 has moved in between, if the holding jig 30 is moved in the axial direction from the shaft body 8, the shaft body 8 is easily detached from the holding jig 30 by its own weight due to the presence of the air layer. Therefore, a situation such as a line stop during the manufacturing process can be avoided, and the productivity can be improved.
[0059]
In addition, although the shaft body 8 of each said embodiment is cold forged so that the roughness below 3.2 micrometers may be produced as centerline average roughness (Ra) of each end surface 8d, 8e, centerline average roughness However, since this adhesion usually increases when the thickness is 6.3 μm or less, the present invention is particularly effective in the shaft body 8 having the center line average roughness of this value.
[0060]
【The invention's effect】
As described above, since the cam follower shaft body of the present invention has convex portions at both end portions thereof, when the holding jig is separated from the shaft body in the axial direction, the cam follower shaft body is caused by the presence of an air layer. Can be easily separated from the holding jig by its own weight, and therefore, a situation such as a line stop during the manufacturing process can be avoided, and the productivity can be improved.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing an entire rocker arm according to an embodiment of the present invention.
FIG. 2 is a side view showing the usage state of the rocker arm.
FIG. 3 is a cross-sectional view showing a state where the shaft body is also caulked to the peripheral surface of the support hole.
FIG. 4 is a schematic diagram of a single shaft body. FIG. 5 is an explanatory view showing a manufacturing process of the shaft body.
FIG. 6 is a configuration diagram of a shaft body showing another embodiment.
FIG. 7 is a configuration diagram of a shaft body showing another embodiment.
FIG. 8 is a configuration diagram of a shaft body showing another embodiment.
FIG. 9 is a configuration diagram of a shaft body showing another embodiment.
FIG. 10 is a cross-sectional view of a conventional rocker arm.
FIG. 11 is an explanatory view showing a manufacturing process of a conventional shaft body.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Rocker arm 3 Roller 4, 5 Opposite wall 6, 7 Support hole 8a, 8b End of shaft 8 Shaft 8c Caulking 14a, 14b Recess 8d, 8e End of shaft 9 Needle roller

Claims (2)

The center outer peripheral surface, which is the raceway surface of the roller, is quenched so as to have a predetermined hardness, and is inserted so as to pass between the circular insertion holes formed in each of the pair of opposing walls constituting the cam follower, and A cam follower shaft body that is caulked so that an end thereof is in pressure contact with a circumferential surface of each circular insertion hole,
On each of the end surfaces, convex portions having an axial height exceeding the amount of unevenness constituting the surface roughness are formed, and these convex portions have the end surfaces with respect to the total area of the end surfaces before the respective caulking. A cam follower shaft body formed in a virtual circle having a diameter not exceeding 80% of the diameter of the cam follower. The center which becomes the raceway surface of the roller in a state where the steel wire is cut at a predetermined axial length, cold forged, and the outer peripheral surface and both end surfaces of both ends are covered and held by a holding jig. The outer peripheral surfaces of the respective end portions are caulked after being quenched so that the outer peripheral surfaces of the respective portions have a predetermined hardness and then inserted into circular insertion holes formed in a pair of opposing walls constituting the cam follower. Is a cam follower shaft that is pressed against the circumferential surface of the insertion hole,
On each of the end surfaces, convex portions having an axial height exceeding the amount of unevenness constituting the surface roughness are formed, and these convex portions have the end surfaces with respect to the total area of the end surfaces before the respective caulking. A cam follower shaft body formed in a virtual circle having a diameter not exceeding 80% of the diameter of the cam follower.

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