JPH0238003Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a hydraulic valve gap adjustment device used in an internal combustion engine.

This type of valve gap adjustment device has a plunger that is slidably fitted into a cylinder body, a high pressure chamber is formed between the lower end of the plunger and the bottom wall of the cylinder body, and a reservoir chamber and a high pressure chamber of the plunger are formed. A check ball valve cooperating with an orifice communicating with the plunger is provided in the high pressure chamber at the lower end of the plunger,
A coil return spring set to an appropriate load is provided between the lower end of the plunger and the bottom wall of the cylinder.

However, such conventional devices have the disadvantage that the check valve consists of a check ball, a coil spring, and a retainer, so there are many parts, it takes a lot of time to assemble, and it is difficult to manage parts. .

The present invention was developed by focusing on these conventional problems.The retainer and check ball coil spring that constitute the conventional check valve are omitted, and the check valve is constructed only with a return spring and a check ball. . According to the invention, this is achieved by integrally forming a retainer part for the check ball on the return spring.

Hereinafter, the present invention will be explained based on the drawings.

To explain one embodiment of the present invention shown in FIG. 1, the engine cylinder head has a cylinder body 5.
is attached, and a plunger 4 is slidably fitted into the cylinder body 5. A rocker arm 2 is slidably linked to the upper end of the plunger 4, and the valve 1 is moved in accordance with the movement of the cam 3. A reservoir chamber 11 is formed within the plunger and communicates with a cylinder head hydraulic circuit 13 through oil supply ports 14 and 15 provided in the cylinder body 5 and plunger 4, respectively.

A high pressure chamber 12 is formed between the lower end of the plunger 4 and the bottom wall of the cylinder 5, and a return spring 10 with an appropriate set load is placed. A recess 4' is formed at the lower end of the plunger 4,
A check ball 9 is placed here which cooperates with an orifice communicating the reservoir chamber 11 and the high pressure chamber 12.

The upper end of the return spring 10 is bent inward to form a retainer portion 10' that holds the check ball 9 to prevent it from falling.
Thus, the check valve consisting of a check ball prevents oil from flowing back from the high pressure chamber 12 to the reservoir chamber 11.

A stopper 6 is attached to the upper end of the cylinder to prevent the plunger from coming off, and the cylinder is also provided with a stop end 16 for the plunger.

Figures 2a, b and c are plan views showing various examples of return springs, and it will be appreciated that the inwardly bent retainer portion at the upper end of the spring may take any desired form.

Assuming that the reservoir chamber 11 and the high pressure chamber 12 are filled with oil, when the engine valve 1 opens according to the movement of the cam 3, a load is applied to the plunger 4, and the check valve 9 closes, generating high pressure in the high pressure chamber 12. do. Oil in the high pressure chamber 12 leaks slightly through a small gap between the cylinder 5 and the plunger 4.
The plunger is displaced accordingly. When the engine valve closes, the plunger 4 is pushed back by the return spring 10, the check valve 9 is opened, and oil is supplied from the reservoir chamber 11 through the orifice to the high pressure chamber 12.
Oil is supplied from a cylinder head oil circuit 13 through the cylinder head oil circuit 13.

When the engine is stopped while the engine valve remains open, the plunger moves until it contacts the plunger stop 16. In this state, when the engine is started, the check valve can open and the plunger returns to its original position. In this way, the gap in the valve train is always adjusted to zero.

According to the present invention, since the upper end portion of the return spring 10 is bent inward to form the retainer portion 10', it is possible to prevent the check valve consisting of the check ball 9 from falling.
The valve function of the check valve can be ensured at all times without requiring a conventional retainer.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a hydraulic valve gap adjusting device according to the present invention, and FIGS. 2a, 2b, and 2c are plan views of a return spring used in the device of the present invention. 4...Plunger, 5...Cylinder body, 1
0...Return spring, 11...Reservoir chamber, 12...High pressure chamber, 9...Check valve, 10'
...Retainer part.

Claims (1)

[Scope of utility model registration request] A plunger is slidably fitted into a cylinder body with one end closed, a high pressure chamber is formed between the lower end of the plunger and the bottom wall of the cylinder body, and an orifice is provided that communicates the reservoir chamber of the plunger with the high pressure chamber. A hydraulic valve gap adjusting device comprising a cooperating check ball valve at the lower end of the plunger, and a coil return spring set with an appropriate load between the bottom end of the cylinder body and the lower end of the plunger, A hydraulic valve gap adjustment device characterized in that the upper end of a coil return spring is bent inward to serve as a check ball retainer.