JPH0512606U - Tapestry mechanism - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent uneven wear on the bottom surface of the tappet body that is biased by the rotating cam. [Structure] An outer race 21 of a thrust bearing 20 is fixed to a bottom surface 17 of a tappet body 11, and a lower surface 24 of an inner race 23 thereof is brought into contact with an outer peripheral surface 30 of the rotating cam 14 which is inclined in the axial direction.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a tappet mechanism in an internal combustion engine or the like.

[0002]

[Prior Art]

 In the conventional tappet mechanism for an internal combustion engine or a reciprocating pump, as shown in FIG. 2, a cylindrical tappet body 1 receives the lower end of a push rod 3 at the center of its bottom 2 and a rotating cam from below. The push rod 3 is pushed up and down along the tappet guide 5 and pushed up the push rod 3 at an appropriate timing for an appropriate time, but the outer peripheral surface of the cam 4 is slightly inclined in the rotation axis direction. By contacting the bottom surface of the tappet body 1 at a point slightly deviated from the center of the tappet body 1, when the cam 4 biases the tappet body 1, the tappet body 1 is given a rotational force about its axis, and the cam 4 is changed to prevent the bottom surface of the tappet body 1 from being unevenly worn by changing the position of the bottom surface of the tappet body 1 in contact with the tappet body 1. It led from the hole 6 to the contact portion between the outer peripheral surface of the tappet body 1 bottom and the cam 4, lubricates the parts. However, if the tappet body 1 does not rotate uniformly about its axis, the oil film at the contact portion may not be formed well, and the original uneven wear prevention may not always be complete.

[0003]

[Problems to be solved by the device]

 An object of the present invention is to make it possible to uniformly rotate a tappet body urged by a cam around its axis, thereby completely preventing uneven wear of the bottom surface of the tappet body.

[0004]

[Means for Solving the Problems]

 In order to achieve this object, the tappet mechanism according to the present invention has one side of a thrust bearing attached to the bottom surface of the tappet body, and the other side of the thrust bearing abuts the outer peripheral surface of the rotating cam, and The outer peripheral surface is inclined in the direction of the rotation axis.

[0005]

[Action]

 Therefore, when the tappet body is axially urged by the outer peripheral surface of the rotating cam, the thrust bearing receives the rotational force generated by the inclination of the outer peripheral surface of the rotating cam, and the thrust bearing contacts the outer peripheral surface of the rotating cam. Since the other side of the bearing can easily rotate around its axis, the other side surface of the thrust bearing can evenly contact the outer peripheral surface of the rotating cam without bending.

[0006]

【Example】

 Hereinafter, the embodiment of the present invention shown in FIG. 1 will be described in detail. The cylindrical tappet body 11 of the internal combustion engine receives the lower end of the push rod 13 at the center of its bottom portion 12, while the bottom surface 17 of the tappet body 11 is formed with a central projection 18 which is a thrust bearing. The outer race 21 of 20 is press-fitted, screwed, or fitted into the central hole 22 of the outer race 21 and fixed by adhesion or the like, and the tappet body bottom surface 17 is in contact with the upper surface of the outer race 21. The inner race 23 of the thrust bearing 20 is made of a wear-resistant material such as a sintered alloy, and its lower surface 24 is in contact with the outer peripheral surface 30 of the rotating cam 14, so that the cam 14 rotates in accordance with the rotation of the cam 14. The outer peripheral surface 30 pushes up the tappet body 11 via the thrust bearing 20, and the tappet body 11 is guided by the tappet guide 15 to move up and down, pushing up the push rod 13.

On the other hand, in FIG. 1, the vertical cross-sectional shape of the rotating cam 14 in the direction perpendicular to the paper surface is shown by the one-dot chain line, and as is apparent from this, the cam outer peripheral surface 30 is inclined in the rotational axis direction. , The inner race 23 comes into contact with the inner race lower surface 24 at a point deviated from the center of the inner race 23. Therefore, when the inner race 23 of the thrust bearing 20 is pushed up while the cam 14 rotates, the inner race 23 receives a rotational force about its axis. Be done. Further, an oil hole 16 is formed in the bottom 12 of the tappet body, and the lubricating oil that has dripped into the tappet body 11 from above flows out from this oil hole 16, and the thrust bearing 20, the inner race lower surface 24, and the cam outer circumference. It is guided to the contact portion of the surface 30 and lubricates those portions.

For this reason, the inner race 23 easily rotates around its axis, for example, about 0.5 to 0.7 rotation per one rotation of the cam 14, and a uniform oil film is formed on the lower surface 24 thereof. Since the position of the inner race lower surface 24 that comes into contact with the cam outer peripheral surface 30 always moves smoothly, uneven wear does not occur on the inner race lower surface 24, and therefore abnormal wear does not occur in the entire device at all. Therefore, stable operation of the internal combustion engine for a long time becomes possible.

In the above embodiment, the entire inner race 23 of the thrust bearing 20 is made of a wear-resistant material such as a sintered alloy. However, the side of the inner race 23 that contacts the rolling ball 25 is It is made of an alloy material that has high strength and is easy to perform precision molding, and a sintered alloy with high wear resistance is fixed on the opposite side by adhesion or welding to contact the outer peripheral surface 30 of the cam. You can also do so.

[0010]

[Effect of the device]

 In the tappet mechanism according to the present invention, the thrust bearing is interposed between the tappet body and the rotating cam, so that the side of the thrust bearing that contacts the outer peripheral surface of the rotating cam can easily rotate around its axis. Therefore, the rotating cam side of the thrust bearing uniformly contacts the outer peripheral surface of the rotating cam, and it is possible to easily prevent uneven wear.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an embodiment of the present invention.

FIG. 2 is a vertical sectional view of a conventional device.

[Explanation of symbols]

 11 Tappet Main Body 13 Push Rod 14 Rotating Cam 20 Thrust Bearing 21 Outer Race 23 Inner Race 25 Rolling Ball 30 Cam Outer Surface

Claims (1)

[Scope of utility model registration request] 1. A structure in which one side of a thrust bearing is attached to a bottom surface of a tappet body, the other side of the thrust bearing is in contact with an outer peripheral surface of a rotating cam, and the outer peripheral surface of the rotating cam is inclined in a rotation axis direction thereof. Tappet mechanism that has.