JP4019916B2 - Roller follower - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a roller follower.
[0002]
[Prior art]
The roller follower is used in, for example, an engine valve mechanism such as an automobile and other various cam mechanisms.
[0003]
As a structure of the roller follower, a support shaft is bridged between a pair of side walls provided in the body, and a roller is rotatably supported on the outer periphery of the support shaft via a plurality of needle rollers.
[0004]
Each of the pair of side walls is provided with a through hole of the same diameter coaxially, and with respect to each of the through holes of the pair of side walls, both ends of a support shaft having an equal outer diameter over the entire length are fitted and fitted. The gap between the through hole and both ends of the support shaft is filled by brazing (see Patent Document 1).
[0005]
In addition, the support shaft has a stepped shape with only one end side having a large diameter, and a large diameter hole is provided on one side wall, and a small diameter hole is provided on the other side wall. And mounting of the step-shaped support shaft, the small diameter portion of the support shaft is inserted from the large diameter hole of one side wall, the small diameter portion of the support shaft to the small diameter hole of the other side wall, The large-diameter portion of the support shaft is press-fitted into the large-diameter hole of the other side wall (see Patent Document 2).
[0006]
[Patent Document 1]
Japanese Utility Model Publication No. 7-8507 [Patent Document 2]
Utility Model Registration No. 2584333 [0007]
[Problems to be solved by the invention]
In the prior art shown in the above-mentioned patent document 1, the both ends of the support shaft are fitted to each through hole of the pair of side walls and brazed in a state where each through hole and the support shaft are aligned. Therefore, it is pointed out that this centering work is difficult and not only the work efficiency is bad, but also that the mounting reference position of the support shaft to the pair of side walls is difficult to set with high accuracy, so that the product shape accuracy is likely to be lowered. The
[0008]
Although the prior art shown in Patent Document 2 can solve the problems related to the prior art shown in Patent Document 1, a spindle having a stepped shape is manufactured, or holes having different diameters are provided on a pair of side walls. It is pointed out that the mounting direction of the support shaft is limited during assembly.
[0009]
[Means for Solving the Problems]
The roller follower of the present invention includes a pair of side walls opposed in parallel, a support shaft laid between the pair of side walls, and a rolling bearing mounted on the region of the support shaft in a region between the pair of side walls. The rolling bearing includes an inner ring that is press-fitted into the outer peripheral surface of the support shaft, an outer ring that is concentrically mounted on the inner ring via a predetermined facing space, and the outer ring and the inner ring. A plurality of rolling elements interposed therebetween, and the pair of side walls and the inner ring are made of a heat-cured steel material, and through holes having the same diameter are provided coaxially in the pair of side walls, respectively. is and, the support shaft, as well consist of raw steel not thermally cured, which is a uniform outer diameter over the entire length in the pre-mounted state, the support shaft is through the one side wall toward the hole to the through hole of the other side wall By being engaged Nyuhama, the press-fitting direction front side of the support shaft is fixed in the axial and circumferential directions become tight fit against the through hole of the one side wall, embossing caulking both end faces of the support shaft By being applied only to the end face on the tip side in the press-fitting direction, the tip side of the support shaft is fixed in the axial direction and the circumferential direction with respect to the through hole of the other side wall.
[0010]
In this case, use a rolling bearing with an inner ring for the roller follower so that the outer peripheral surface of the support shaft does not become the raceway surface of the rolling element of the rolling bearing, and then press-fit one end of the support shaft into the through hole on one side wall. The following effects are obtained by the synergistic effect of adopting a structure in which the other end of the support shaft is fixed to the through hole in the other side wall by stamping.
[0011]
First, the support shaft can be a raw steel material that is not heat-cured, and can have a simple outer shape that does not have a stepped shape as in the conventional example. Thereby, a spindle can be manufactured cheaply. Further, compared to the prior art disclosed in Patent Document 1 and the case where both ends of the support shaft are stamped, it is easy to set the support reference position of the support shaft with respect to the pair of side walls with high accuracy, and the support with respect to the pair of side walls. The mounting strength of the shaft can be made sufficient.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
1 to 5 show an embodiment of the present invention. The illustrated roller follower 1 includes a body 2, a support shaft 3, and a deep groove type ball bearing 4 as a rolling bearing.
[0013]
The body 2 has a pair of side walls 21 and 22 that face each other in parallel, and through holes 23 and 24 having the same diameter are provided coaxially in the middle in the longitudinal direction of the side walls 21 and 22. Tapered chamfers 23 a and 24 a are provided in the outer openings of the through holes 23 and 24.
[0014]
The support shaft 3 is installed between the pair of side walls 21 and 22.
[0015]
The deep groove type ball bearing 4 is externally mounted in a region between the pair of side walls 21 and 22 on the support shaft 3, and includes an inner ring 41, an outer ring 42, balls 43 as a plurality of rolling elements, and a corrugated cage 44. And have. The inner ring 41 is externally fitted to the support shaft 3 by press fitting, and the outer ring 42 is rotatable. That is, the outer ring 42 is used as a roller of the roller follower 1.
[0016]
The body 2, the inner ring 41, the outer ring 42, and the balls 43 are made of a steel material that has been heat-cured, and the support shaft 3 is made of a raw steel material that has not been heat-cured. Specifically, the body 2 is, for example, JIS standard SCM415 or JIS standard SPC. The inner / outer rings 41 and 42 and the ball 43 are, for example, JIS standard SUJ2. Further, the support shaft 3 is, for example, JIS standards S45C, S55C, JIS standards SUJ2, and the like. Moreover, the carburizing process is mentioned as the thermosetting process with respect to the trunk | drum 2, the inner ring | wheel 41, the outer ring | wheel 42, and the ball 43. FIG.
[0017]
Here, the assembly procedure of the roller follower 1 will be described.
[0018]
First, as shown in FIG. 3, the support shaft 3 made of a raw steel material that has not been heat-cured and having a uniform outer diameter over the entire length is connected to the second through the inner ring 41 from the through hole 23 of the first side wall 21. Press-fitting into the through hole 24 of the side wall 22 is performed.
[0019]
In the final stage of the press-fitting process, as shown in FIG. 4, the inner ring 41 is moved into the second side wall 22 by causing the tip end side of the support shaft 3 to protrude from the outer opening of the through hole 24 of the second side wall 22. By pressing against the side surface, the gap h <b> 1 is provided only between the inner ring 41 and the inner side surface of the first side wall 21.
[0020]
Subsequently, as shown in FIG. 5, the support shaft 3 is pushed back by a predetermined amount in the direction opposite to the press-fitting direction, and between the inner ring 41 and the inner side surface of the first side wall 21 and between the inner ring 41 and the inner side surface of the second side wall 22. Are provided with gaps h2 and h3. The gaps h2 and h3 are respectively set to ½ of the gap h1. The distance between the pair of side walls 21 and 22 and the axial dimensions of the inner and outer rings 41 and 42 are defined so that the gaps h2 and h3 are set to predetermined reference values.
[0021]
By the way, in the above press-fitting process, the support shaft 3 is made softer than the pair of side walls 21, 22 and the inner ring 41, so that the front end side of the support shaft 3 in the press-fitting direction passes through the through hole 23 of the first side wall 21. In the process, plastic deformation is performed so that the outer diameter is reduced by a predetermined amount, and then, plastic deformation is performed so that the outer diameter is further reduced by a predetermined amount in the process of passing through the inner circumference of the inner ring 41.
[0022]
For this reason, the outer diameter dimension of the support shaft 3 after installation is three steps, although it is slight. That is, in the support shaft 3, the outer diameter r1 of the region (corresponding to the front side in the press-fitting direction) fitted to the through hole 23 of the first side wall 21, the outer diameter r2 of the region fitted to the inner ring 41, The relationship between the outer diameter r3 of the region (the tip side in the press-fitting direction) fitted in the through hole 24 of the two side walls 22 is r1>r2> r3. In consideration of the fact that the difference in outer diameter between the three regions in the support shaft 3 is as small as μm, FIG. 1 does not show the outer diameter of the support shaft 3 in three stages.
[0023]
For this reason, the front side of the support shaft 3 in the press-fitting direction is “fitting fit” with respect to the through hole 23 of the first side wall 21 and is fixed in the axial direction and the circumferential direction. Since the tip end in the direction is a “clearance fit” with respect to the through hole 24 of the second side wall 22, the tip end side in the press-fitting direction of the support shaft 3 is not fixed in the axial direction and the circumferential direction. become.
[0024]
Therefore, after the support shaft 3 is attached as described above, the end surface of the support shaft 3 on the tip side in the press-fitting direction is stamped. As shown in FIG. 5, this stamping is performed by driving a blade of a processing tool 6 such as a punch into the end face of the support shaft 3 on the front end side in the press-fitting direction to thereby end the end face of the support shaft 3 on the front end side in the press-fitting direction. At the same time, a substantially O-shaped groove 31 is engraved in a plan view, and at the same time, the outer periphery of the support shaft 3 on the front end side in the press-fitting direction is plastically deformed so as to rise radially outward. The raised portion 32 is pressed against a tapered chamfer 24 a provided in the outer opening of the through hole 24 of the second side wall 22, and the base of the raised portion 32 is the through hole 24 of the second side wall 22. Is pressed against the outer opening side of the inner peripheral surface of the shaft, the support shaft 3 is also fixed to the through hole 24 of the second side wall 22 in the axial direction and the circumferential direction.
[0025]
In the above assembling process, the deep groove type ball bearing 4 is provided with the inner ring 41, so that the rollers which are essential in the conventional example in which a plurality of rollers are directly arranged on the outer peripheral surface of the support shaft 3 and the rollers are externally fitted. No drop-off prevention tool is required. In addition, if the deep groove type ball bearing 4 with the inner ring 41 is used, a slight inclination of the outer ring 42 can be allowed by the radial gap provided inside the deep groove type ball bearing 4. Misalignment with the abutted member can be absorbed.
[0026]
As described above, the deep groove type ball bearing 4 with the inner ring 41 is used for the roller follower 1 and one end of the support shaft 3 is fixed to the through hole 23 of the first side wall 21 by press fitting. With the synergistic effect of adopting a structure in which the other end of 3 is fixed to the through hole 24 of the second side wall 22 by stamping, the following effects can be obtained.
[0027]
First, since the outer peripheral surface of the roller support shaft 3 is not used as the raceway surface of the ball 43 of the deep groove type ball bearing 4, the support shaft 3 is simply fixed to the inner ring 41 by press fitting. As a result, the support shaft 3 can be made of a raw steel material that is not heat-cured, and the support shaft 3 can have a simple outer shape that does not have a stepped shape as in the conventional example. It can be manufactured at low cost and can contribute to the cost reduction of the roller follower 1. In addition, compared to the prior art shown in Patent Document 1 and the case where both ends of the support shaft 3 are stamped, it is easy to set the attachment reference position of the support shaft 3 with respect to the pair of side walls 21 and 22 with high accuracy, Since the attachment strength of the support shaft 3 with respect to the pair of side walls 21 and 22 can be made sufficient, the shape accuracy of the product can be increased, which contributes to the improvement of quality and reliability.
[0028]
Next, FIG. 6 shows a roller follower according to another embodiment of the present invention. The roller follower 1 here is different from the embodiment shown in FIG. 1 in that two deep groove ball bearings 4A and 4B are used. In the roller follower 1 shown in the above embodiment, the deep groove ball bearings 4, 4A, 4B can be replaced with other types of rolling bearings such as cylindrical roller bearings, needle roller bearings, and the like.
[0029]
Incidentally, the roller follower 1 described above can be used for rocker arms 10 and 20 of an engine valve mechanism such as an automobile, for example, as shown in FIGS. Of course, the roller follower 1 can be used for a rocker arm other than these rocker arms 10 and 20 and various other mechanisms.
[0030]
The rocker arm 10 shown in FIG. 7 is called a center pivot type. The roller follower 1 is provided at one end in the longitudinal direction of the body 2, the rocker shaft 71 is penetrated in the middle in the longitudinal direction, and the other end in the longitudinal direction is further provided. An adjusting screw 11 is screwed on. A stem end of a valve 72 of a valve operating mechanism installed in the cylinder head is brought into contact with the adjustment screw 11. As the cam 73 rotates, the body 2 is tilted with the rocker shaft 71 as a fulcrum, and the adjusting screw 11 is repeatedly displaced in the vertical direction to open and close the valve 72.
[0031]
The rocker arm 20 shown in FIG. 8 is called an end pivot type. The roller follower 1 is provided in the middle of the body 2 in the longitudinal direction, the valve insertion portion 21 is provided at one end in the longitudinal direction, and the other end in the longitudinal direction is provided. An upward hemispherical pivot portion 22 is provided. The pivot portion 22 is engaged with an upper end of a lash adjuster 74 installed on a cylinder head (not shown). As the cam 73 rotates, the body 2 is tilted with the pivot portion 22 as a fulcrum, and the valve insertion portion 21 is repeatedly displaced in the vertical direction, thereby opening and closing the valve 72.
[0032]
In the automobile engine in which these rocker arms 10 and 20 are installed, there is a tendency to use low-viscosity type engine oil in which specific additives are reduced from the viewpoint of environmental protection, and the engine oil around the rocker arms 10 and 20 is used. Although the lubrication conditions of the roller follower 1 have become severe, such as being less, as the operation of the roller follower 1 becomes smooth as described above, the life of the rocker arms 10 and 20 can be improved.
[0033]
【The invention's effect】
In the present invention, the following effects can be obtained. First, since the support shaft is made of a raw steel material that is not heat-cured and has a simple outer shape with a uniform outer diameter over the entire length, the support shaft can be manufactured at a low cost and can contribute to the cost reduction of the roller follower. Further, compared to the prior art disclosed in Patent Document 1 and the case where both ends of the support shaft are stamped, it is easy to set the support reference position of the support shaft with respect to the pair of side walls with high accuracy, and the support with respect to the pair of side walls. Since the shaft mounting strength can be made sufficient, the shape accuracy of the product can be increased, which contributes to the improvement of quality and reliability. Therefore, the present invention can provide an inexpensive and highly reliable roller follower.
[Brief description of the drawings]
1 is a cross-sectional view showing a roller follower according to an embodiment of the present invention. FIG. 2 is a side view of the roller follower shown in FIG. 1. FIG. 3 is a view showing an initial stage in the process of incorporating the roller follower shown in FIG. 4 is a diagram showing a state in which the support shaft is pushed to a predetermined position from the state of FIG. 3. FIG. 5 is a diagram showing a state in which the clearance is adjusted by pushing back the support shaft in the direction opposite to the press-fitting direction from the state of FIG. FIG. 7 is a cross-sectional view showing a roller follower according to another embodiment of the present invention. FIG. 7 is a side view showing an example of usage of the roller follower according to the present invention. Side view showing [signs]
DESCRIPTION OF SYMBOLS 1 Roller follower 2 Body 21 The 1st side wall 22 of a body The 2nd side wall 23 of a body The through-hole 24 of the 1st side wall The through-hole 3 of the 2nd side wall 4 Support shaft 4 Deep groove type ball bearing 41 Inner ring 42 of a deep groove type ball bearing Deep groove type ball Bearing outer ring 43 Ball of deep groove type ball bearing

Claims (1)

A pair of side walls facing in parallel, a support shaft constructed between the pair of side walls, and a rolling bearing externally mounted in a region between the pair of side walls on the support shaft;
The rolling bearing includes an inner ring that is press-fitted into the outer peripheral surface of the support shaft, an outer ring that is concentrically mounted on the inner ring via a predetermined facing space, and the outer ring and the inner ring. A plurality of rolling elements interposed therebetween,
The pair of side walls and the inner ring are made of a heat-cured steel material, and through holes having the same diameter are provided coaxially in the pair of side walls,
The support shaft, as well as consists of raw steel not thermally cured, which is a uniform outer diameter over the entire length in the pre-mounted state, the support shaft is from said through hole of one of the side walls other By press-fitting into the through hole in the side wall, the front side of the support shaft in the press-fitting direction becomes an interference fit with the through hole in the one side wall, and is fixed in the axial direction and the circumferential direction. Is applied only to the end face on the front end side in the press-fitting direction among both end faces of the support shaft, so that the front end side of the support shaft is fixed in the axial direction and the circumferential direction with respect to the through hole of the other side wall . Roller follower.

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