KR19980016481A - Direct acting hydraulic valve lifter - Google Patents

Abstract

The present invention relates to a directional plunger and a lifter body directly operated by a cam to adjust the valve clearance and open and close the valve, thereby reducing the volume and reducing the noise. A plunger that is in contact with the cam and moves up and down by rotation of the cam, a lifter body into which the plunger is inserted to move the valve up and down, a return spring positioned below the plunger and pushing the lifter body downward, and a lower side of the plunger A check ball for opening and closing the oil hole of the, and the retainer is provided on the lower side of the plunger to prevent the departure of the check ball.

The direct-acting hydraulic valve lifter of the present invention has a simple structure and easy installation and a reduction in installation cost because the cam acts directly on the plunger to open and close the valve through the body and at the same time the valve clearance is always maintained at zero. In addition, since the separation air and the air outlet are formed in the plunger to discharge the inflow air, noise is reduced and the operation of the cam is accurately transmitted to the valve.

Description

Direct acting hydraulic valve lifter

1 is a cross-sectional view showing the installation state of a conventional direct-acting hydraulic valve lifter.

2 is a cross-sectional view showing an installation state of the linear hydraulic valve lifter according to the present invention.

* Description of the symbols for the main parts of the drawings *

11: cam 13: valve 14: cylinder head

22: plunger 23: oil hole 24: air outlet

26: separator 31: lifter body 33: oil supply port

34: liter spring 36: check ball 38: retainer

H: High pressure chamber L: Low pressure chamber

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic valve lifter that controls the valve clearance of the intake and exhaust valves to always be zero. Particularly, the plunger and the lifter body operated by the direct cam are configured to adjust the valve clearance and open and close the volume. The reduction is of course related to actuated hydraulic valve lifters which have reduced noise.

In general, since each component of the valve mechanism expands as the temperature of the engine rises, the valve also expands so that the valve face and the valve seat do not come into close contact with each other, causing gas leakage. To prevent this, a valve clearance is provided to maintain a certain gap when the engine reaches operating temperature.

The change in the valve clearance has a great effect when opening and closing the valve, the gap is too large, the noise is generated and gives a shocking force to each part of the valve mechanism, to maintain the performance of the engine, to prevent abnormal wear or noise, Always adjust to the appropriate value. By the way, since the valve clearance causes noise and handling to become complicated, the valve lifter was invented to eliminate these.

As such, the valve lifter is divided into a mechanical valve lifter and a hydraulic valve lifter. Among them, the hydraulic valve lifter uses the incompressibility of oil to maintain the valve clearance at zero at all times regardless of cold or warm, so that the noise generated in the valve gap is eliminated and the size of the valve clearance need not be controlled. It has the advantage of less wear because it does not impact the instrument.

Conventional actuated hydraulic valve lifters have a body 2 that moves up and down by the action of the cam 1 as shown in FIG. 1, and a plunger positioned within the body 2 to move the valve 3 up and down. It consists of (4).

The plunger 4 is located between the plunger head 5 receiving the action force of the body 2 and the plunger seat 6 positioned below the plunger head 5. The low pressure chamber (L) is located inside the plunger seat (6), the high pressure chamber (H) is located below the plunger seat (5), and the low pressure type (L) and the high pressure chamber (H). Supply hole 6a is opened and closed by check ball 7. In addition, a return spring 8 is installed in the lower side of the plunger seat 6 and the bottom of the plunger 4, that is, in the high pressure chamber H.

Here, oil is introduced between the plunger 4 and the plunger head 5 through the oil supply port 2a on the side of the body 2.

The conventional direct acting hydraulic valve lifter configured as described above receives the action force by the rotation of the cam 1 to directly open and close the valve 3 by linearly moving the valve 3, and also keeps the valve clearance at zero at all times. .

When the cam 1 does not act on the body 2, that is, when the valve 3 is closed, the oil supplied through the oil supply port 2a on the side of the body 2 is discharged from the high pressure chamber L. Oil is filled up to the chamber (H). At this time, the return spring 8 installed in the high pressure chamber H pushes the plunger seat 6, the body 2 is in contact with the cam 1 by the plunger seat 6, and the plunger 4 is In contact with the valve stem 3, the valve clearance becomes zero.

Pressing the body 2 downward while the cam 1 rotates moves the plunger head 5 and the plunger seat 6 downward. At this time, the oil in the high pressure chamber (H) is pressurized and the check ball (7) blocks the supply hole (6a) of the plunger seat and the oil filled in the high pressure chamber (H) does not come out and pushes the plunger (4) downward. . Thus, the action force of the cam 1 transmitted from the body 2 is transmitted to the valve stem 3 while moving the plunger 4 downward to open the valve.

However, in the conventional direct acting hydraulic valve lifter configured as described above, air is mixed in the supplied oil when it is operated for a long time, and the air in the oil is separated from the high pressure chamber (H). When pressurized in such a state, air is compressible compared to oil, and thus a sponge phenomenon occurs in which the valve driving force of the cam 1 is not accurately transmitted to the valve 3. When the sponge phenomenon occurs, the vibration occurs in the valve mechanism has a problem that the noise is severe.

In addition, the prior art also has a problem that each component constituting the plunger is complicated and bulky and the cost increases.

Therefore, the present invention has been made to solve the above-mentioned problems, when the cam operates the plunger, the body directly opens and closes the valve by the hydraulic pressure and the clearance to zero, thereby reducing the volume and noise reduced direct acting hydraulic valve The purpose is to provide a lifter.

The direct acting hydraulic valve lifter of the present invention for achieving the above object has a plunger in which an oil hole is formed at a lower side thereof, the upper surface of which is in contact with the cam, and moves up and down by rotation of the cam, and the plunger is inserted to move the valve up and down. A lifter body, a return spring positioned below the plunger to push the lifter body downward, a check ball for opening and closing the oil hole in the lower part of the plunger, and a retainer installed under the plunger to prevent the check ball from being detached. Characterized in that configured.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

In the linear hydraulic valve lifter according to the present invention, as shown in FIG. 2, the oil hole 23 is formed on the lower side, and the plunger 22 moves up and down by the rotation of the cam 11 in contact with the cam 11 on the upper surface thereof. And a lifter body 32 into which the plunger 22 is inserted to move the valve 13 up and down, and a return spring 34 positioned below the plunger 22 to push the lifter body 32 downward. ), A check ball 36 for opening and closing the oil hole 23 below the plunger 22, and a retainer 38 disposed below the plunger 22 to prevent the check ball 36 from being separated. do.

A low pressure chamber L is formed inside the plunger 22, and a high pressure chamber H is formed between the lower side of the plunger 22 and the lifter body 32, and the low pressure chamber L and the high pressure chamber ( H) is connected through the oil hole 23 and opened and closed by the check ball 36.

An oil supply port 33 communicating with the oil supply passage 14a of the cylinder head 14 is formed at one side of the plunger 22 and the lifter body 32 to supply oil into the plunger 22.

In addition, an air discharge port 24 is formed on the upper surface of the plunger 22 so that the air inside due to oil inflow is discharged to the outside, and a separation membrane having a hole in the center to separate oil and air inside the plunger 22 ( 26) is installed.

Referring to the operation and effects of the present invention configured as described above are as follows.

When an acting force due to rotation of the cam 11 is applied to the plunger 22, the plunger 22 moves up and down linearly according to the contact with the cam 11. When the cam 11 is rotated and the plunger 22 is pressed, the plunger 22 moves downward. At this time, the oil in the high pressure chamber H is pressurized so that the check ball 36 blocks the oil hole 23. Therefore, the oil in the high pressure chamber H is not pressurized and is pressurized so that the lifter body 32 moves downward along with the plunger 22 to move the valve 13 to open the combustion chamber.

When the cam 11 continues to rotate to weaken the action force, the plunger 22 rises and the lifter body 32 also rises to close the valve 13. At this time, the oil hole 23 of the high pressure chamber H is opened by the rise of the plunger 22 and the oil of the low pressure chamber L flows into the high pressure chamber H in a predetermined amount.

Here, the return spring 34 pushes the lifter body 32 in the opposite direction to the plunger 22 to keep the clearance between the valve 13 and the lifter body 32 at zero.

On the other hand, when oil is supplied through the oil supply port 33 of the linear hydraulic valve lifter, air is separated upward by the separator 26 and is discharged to the outside through the air outlet 24.

The linear hydraulic valve lifter of the present invention constructed and operated as described above is easy to manufacture and easy to install because the cam is directly worn on the plunger to open and close the valve through the body, and at the same time, the valve clearance is always maintained at zero. Has the advantage of saving money.

In addition, the present invention has the advantage that the noise is reduced and the operation of the cam is correctly transmitted to the valve because the separation air and the air outlet to form a separator in the plunger to discharge the incoming air.

Claims (4)

A plunger having an oil hole formed in the lower side thereof and moving up and down by the rotation of the cam in contact with the cam on the upper surface, a lifter body into which the plunger is inserted to move the valve up and down, and a lower portion of the plunger positioned to push the lifter body downward. And a return spring, a check ball for opening and closing the oil hole in the lower part of the plunger, and a retainer provided in the lower part of the plunger to prevent the check ball from detaching. The method of claim 1, And an oil supply port communicating with the oil supply flow path of the cylinder head on one side of the plunger and the body. The method of claim 1, An air discharge port is formed on the upper surface of the plunger so that the air is discharged to the outside. The method of claim 1, Direct hydraulic valve lifter, characterized in that the separation membrane is provided with a hole in the center so that the air escapes inside the plunger.