JPH09256822A - Valve spring structure for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deterioration in fuel consumption and generation of noise and the like by putting in/out oil below a spring receiver supporting one end of a spring, which applies a load required for a valve opening/closing mechanism, and varying the load of the spring in compliance with an engine rotational speed. SOLUTION: In value guide 2 in which a valve 1 is arranged in the center, a ring type support member 3 is arranged in the lower outer circumference, and on the inside face of the support member 3, a spring lower receiving member 4 is arranged. A coil spring 7 with a large diameter is elastically arranged between the lower receiving member 4 and a spring upper receiving member 5 matched with the lower receiving member 4, while a coil spring 8 with a small diameter is elastically arranged between a stepped part 6 in the upper receiving member 5 and the lower receiving member so as to surround the valve 1. A clearance between the support member 3 and the lower receiving member 4 is used as an oil chamber, and oil is inputted/outputted to/from the oil chamber via an inlet 9 in compliance with the engine rotational speed, so that optimum load values can be added for the coil springs 7, 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve spring structure of an internal combustion engine, and more particularly to an improvement of a valve spring structure for applying a load to a valve for intake, exhaust, etc. for executing an auto cycle.

[0002]

2. Description of the Related Art Generally, the above-mentioned valve spring has a set length, that is, a load value, which predicts the maximum engine speed and is set in accordance with this.

[0003]

However, according to this conventional valve spring structure, the spring load is in an excessive state with respect to the engine speed during normal running, idling, etc. The minute is regarded as a mechanical loss of the engine itself, that is, it has been a cause of power loss, burden on the valve train, deterioration of fuel consumption and noise generation.

[0004]

SUMMARY OF THE INVENTION The present invention has been made by paying attention to the actual situation and problems of the above-mentioned conventional techniques. By solving these problems, loss is eliminated and a suitable load suitable for the operating condition of the engine is provided. An object of the present invention is to provide a valve spring structure for an internal combustion engine which can be obtained by changing the set length of the valve spring each time.

[0005]

In order to achieve this object, a valve spring structure for an internal combustion engine according to the present invention comprises:
In the valve spring structure of the internal combustion engine, which is provided with a spring receiver around the valve guide in which the valve is arranged at the center, and the spring which elastically applies a load required for the valve opening / closing mechanism to the spring receiver is described above. It is characterized in that oil and the like can be put in and out below the spring receiver to change the load of the spring in accordance with the engine speed.

[0006]

With the above structure, the spring receiver is hydraulically moved up and down according to the engine speed, and the spring set length, that is, the spring load, suitable for the engine speed can be obtained each time. As a result, power loss, burden on the valve train, deterioration of fuel consumption, noise generation, etc. can be eliminated.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a vertical cross-sectional view of a main part showing a valve spring structure of an internal combustion engine embodying the present invention.

In FIG. 1, reference numeral 1 denotes a valve, and reference numeral 2 denotes a valve guide having a substantially cylindrical shape with the valve 1 arranged at the center. Further, an annular support member 3 having an upwardly U-shaped cross section is provided on the outer periphery of the lower end of the valve guide 2.

A lower receiving member 4 of a coil spring, which will be described later, having an outer peripheral surface in sliding contact with the inner peripheral surface of the supporting member 3 is provided on the inner surface of the supporting member 3 with a clearance from the inner surface bottom portion of the supporting member 3. ing. The lower receiving member 4 is also U-shaped in an upward cross-section, and is formed in an annular shape so as to follow the supporting member 3. The stopper 3a provided on the inner surface of the supporting member 3 prevents the lower receiving member 4 from coming out upward. ..

On the other hand, reference numeral 5 in the drawing denotes an upper receiving member of a coil spring which is provided around the valve 1 and corresponds to the lower receiving member 4. The upper receiving member 5 has a flange shape, and a step portion 6 is provided at a corner portion. It has a ring shape.

A first coil spring 7 made of a thick material and having a large diameter is elastically provided between the upper receiving member 5 and the lower receiving member 4, and a thin material is provided between the step portion 6 and the lower receiving member 4. A second coil spring 8 having a small diameter is provided so as to surround the valve 1.

Further, an oil inlet / outlet 9 connected to the hydraulic system is formed in the lower end side surface of the support member 3 and the oil injected from the inlet / outlet 9 is received by the lower receiving member 4.
The bottom surface of the above is pressed to resist the urging force of the coil springs 7 and 8, and the lower receiving member 4 is pushed upward.

The valve spring structure of the internal combustion engine according to the present embodiment is constructed as described above. Therefore, on the lower surface of the lower receiving member 4 of the coil springs 7 and 8,
Oil flows in and out according to the engine speed, and the distance S between the inner bottom surface of the support member 3 and the lower surface of the lower support member 4 is changed according to the engine speed, and the change causes the coil spring, particularly the set length of 7 to be set. Y changes, and the most suitable load values of the coil springs 7 and 8 are added.

That is, the value of S is minimum, the value of Y is maximum and the load from the coil springs 7 and 8 is minimum during idling or in a low rotation range. On the contrary, in the high rotation range, the value of S is maximum, Y is minimum, and the load is maximum.

[0015]

The valve spring structure for an internal combustion engine according to the present invention is constructed and operates as described above. That is, S
Since the value of will be variable, a load value suitable for the engine speed will be set each time,
It is possible to avoid power loss, valve system load, fuel consumption deterioration, noise generation, and the like.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a valve spring structure of an internal combustion engine embodying the present invention.

[Explanation of symbols]

 1 valve 2 valve guide 3 support member 3a stopper 4 lower receiving member 5 upper receiving member 6 stepped portion 7 first coil spring 8 second coil spring 9 inlet / outlet

Claims (1)

[Claims] 1. A valve spring for an internal combustion engine, comprising a spring guide around a valve guide having a valve arranged in the center, and a spring for elastically applying a load required for the valve opening / closing mechanism to the spring receiver. In the structure, a valve spring structure for an internal combustion engine is characterized in that oil or the like can be put in and out below the spring receiver, and a load of the spring is changed according to an engine speed.