JP2527811Y2 - Tappet - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tappet used for a direct-acting type valve train, and more particularly to a tappet which facilitates replacement of a shim for adjusting valve clearance.

[0002]

2. Description of the Related Art FIG. 3 schematically shows a direct-acting type valve operating mechanism frequently used in a DOHC type engine. An engine valve (01) includes a pair of cotters (02) and (02) and a spring. Cylinder head by retainer (03), valve spring (04), etc.
(05).

[0003] At the upper end of the engine valve (01), a cylindrical iron tappet (06) whose upper surface is closed is attached to the inner bottom surface of the circular upper wall (07) by the stem of the engine valve (01). so as to abut the end, it is fitted from above.

An annular side wall (0) connected to the upper part of the upper wall (07)
8), a dish-shaped recess (09) is formed inside the recess.
(09) is fitted with a shim (010) for adjusting the valve clearance.

The engine valve (01) has a cylinder head (0)
The tappet (06) guided by 5) is opened and closed by being pushed by the rotating cam (011) brought into contact with the upper surface of the shim (010).

In such a direct acting type valve operating mechanism ,
Adjustment of the valve clearance is performed by replacing the shim (010) with one having a different thickness while the tappet (06) is pressed down against the valve spring (04 ) with an appropriate jig. the shim (010) through the lubricating oil,
Since it is in close contact with the upper surface of the upper wall (07), its removal is very troublesome.

Therefore, as shown in FIG. 4 , the conventional tappet (06) has an annular side wall (0) connected to the upper portion of the upper wall (07).
8), a pair of slit-like notches (012) are formed from above from each other at 180 ° apart in the circumferential direction, and the notches (012) are formed.
A shim (010) is pulled out by inserting a driver or the like into the device.

[0008]

[Problems to be Solved by the Invention] In recent years, the demand for higher speed and higher output of the engine has required a further reduction in the weight of the valve operating system. There is a tendency to move to.

Aluminum alloy tappets are inferior in strength and rigidity to iron tappets.
When the notch groove (012) is formed in the annular side wall (08), particularly when the engine is rotating at high speed, an irregular motion occurs in the valve train, and when a strong outward load is applied to the side wall (08), etc. The stress may concentrate on the notched groove (012), and the side wall (08) may be damaged.

[0010] The present invention has been made to solve the above problem, without decreasing the strength and rigidity of the shim fitting portion, so as to replace the shim can easily perform, deer
Another object of the present invention is to provide a tappet having improved holding properties of lubricating oil for shims .

[0011]

To achieve the above object, according to an aspect of the present invention has an upper surface is provided continuously with the side wall of the annular came upward on the upper end of the body having a cylindrical shape which is closed, surrounded by the side wall into the recess, the tappet comprising fitted detachably shim for adjusting valve clearance, said side walls also
From either the side wall or the top of the shim on either side of the shim.
Compressed air introduction and oil reservoir connected to the bottom of the system and the top of the body
It is characterized in that a round groove is formed .

[0012]

The compressed air is introduced from the side wall or the upper end of the shim connected to the upper end of the body to the lower surface of the shim by the compressed air introduction / oil sump groove, whereby the shim can be easily removed. . Because the side walls are continuous, even if the body is made of aluminum alloy etc., the strength of the shim fitting part,
The stiffness does not decrease.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment of the present invention, in which a tappet has a cylindrical body (2) formed of a light alloy such as an aluminum alloy and a wear-resistant metal material such as chromium or chromium molybdenum steel. Disk-shaped shim
(Not shown) , and the shim is the same as the conventional example described above.
To, in the body recess surrounded by the upper wall (2a) side wall of the continuously provided by the annular came upward from the periphery of the (2) (2b) (4 ), it is fitted as detachable.

[0014] The exchange corner of the upper wall (2a) and side wall (2b), the upper wall
An annular relief groove (5) for polishing the upper surface of (2a) is formed.

On the inner peripheral surface of the side wall (2b), a pair of longitudinal grooves which are recessed outward in an arc shape to almost half of the wall thickness.
(6) The (6) is provided at a circumferential distance of 180 ° from each other .
Is, the lower end of the vertical grooves (6) is not communicated with the clearance groove (5)
You.

[0016] upper surface of the upper wall (2a) is not vertical grooves (6) and spiral compressed air introduction and oil sump groove communicating (9) is formed
You.

FIG . 2 shows a second embodiment of the present invention.
The air introduction and oil sump groove (11) is a radial groove communicating with the circular recess (10) provided in the center of the upper wall (2a) and the vertical groove (6).
There is as.

According to each of the above embodiments , the compressed air blown from above the vertical groove (6) is compressed air introduction and oil sump groove (9).
Or via (11), enters the interface between the shim and the upper wall (2a), the shim (3) so that the float easily.

The compressed air introduction and oil sump groove (9) or (1)
By 1), since the holdings of the lubricating oil is increased, the rotating cam
Shim rotational force upon contact with the (not shown) is adapted to be applied is as shown smooth rotation, moreover, the upper wall
Wear of the contact surface between the (2a) and the shim is suppressed .

[0020]

[Effects of the Invention] (a) Compressed air is introduced into the lower surface of the shim.
Because, shims can be easily sampling Rukoto the.

(B) Unlike the conventional case, it is not necessary to cut out the side wall. Therefore, even if the body is formed of an aluminum alloy or the like, there is no possibility that the strength or rigidity of the shim fitting portion is reduced.

(C) The lubrication of the shim is improved and its rotation
Is also performed smoothly.

[Brief description of the drawings]

FIG. 1 is a central longitudinal sectional front view showing a first embodiment of the present invention.

FIG. 2 is a central longitudinal sectional front view showing a second embodiment of the present invention.
You.

FIG. 3 schematically shows a conventional tappet and a direct-acting type valve operating mechanism.
It is a center vertical section front view.

FIG. 4 is a perspective view of a conventional tappet.

[Explanation of symbols]

(2) Body (2a) Upper wall (2b) Side wall (4) Recess (5) Escape groove (6) Vertical groove (9) (11) Compressed air introduction and oil sump groove (10) Recess

Claims (1)

(57) [Scope of request for utility model registration] 1. A top is provided continuously to come to annular side wall of the upper portion of the body having a cylindrical shape which is closed upward, surrounded by the recess by the side walls, removable shim for adjusting valve clearance in tappet fitted comprising a, on one of the side wall or shim, from the upper end of the side wall or shim, compressed air leading to the upper end surface of the lower surface and the body of the shim
Tappet with an introduction and oil reservoir groove .