JPH0322495Y2 - - Google Patents

Description

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

Conventionally, in this type of device, if the oil in the oil introduction chamber empties before the engine starts, even if hydraulic pressure is supplied at startup, the upper part of the oil introduction chamber becomes an air pocket and oil is not supplied to the reservoir chamber. When the high-pressure chamber consumed all of the oil in the reservoir, there was a problem that air would eventually enter the high-pressure chamber. As a countermeasure to this problem, it is possible to provide a small air outlet above the reservoir chamber. However, this time, when oil containing many air bubbles is supplied to this device while the engine is running, the air bubbles pass through the oil introduction chamber without being separated and reach the reservoir chamber, where they swirl around and exit the outlet. As the oil flows out to the outside, when the high pressure chamber is about to consume the oil in the reservoir chamber, air bubbles also enter the high pressure chamber and the elasticity of the high pressure chamber decreases, which appears as lash in the valve train, causing the valve system to become abnormal. I had a problem with making sounds.

The present invention was developed in view of these problems, and includes a partition wall at the top of the inner plunger to form an oil discharge passage that is separated from the reservoir chamber, and the air in the oil introduction chamber is guided to the oil discharge passage. In addition, the air in the reservoir chamber is guided to the oil discharge passage through the hole provided in the partition wall, and is caused to flow out from the discharge hole, and the flow rate of oil flowing out from the reservoir chamber through the hole in the partition wall is restricted. generation of vortices,
This prevents agitation of air bubbles and allows oil with few air bubbles to be supplied to the high pressure chamber.

Embodiments of the device of the present invention will now be described with reference to the accompanying drawings.

A cylinder body 5 fitted into the cylinder head 1 is in contact with the cam 2 and is provided with an inner lid 6 integral with the cylinder body and an inner cylinder cylinder 7 integral with the inner lid. An outer plunger 9 is slidably fitted into the cylinder inner cylinder 7, and an inner plunger 10 is fitted into the outer plunger. The oil introduction chamber 17 in the cylinder body 5 is
Oil supply recess 15 and oil supply hole 1 formed in
6, it communicates with the oil circuit 4 of the cylinder head.

A reservoir chamber 18 formed inside the inner plunger 10 has an oil supply port 1 of the inner plunger 10.
It communicates with an oil introduction chamber 17 via a check valve 9, and communicates with a high pressure chamber 25 formed between an outer plunger and an inner plunger via a check valve 14. A return spring 13 is provided between the outer plunger and the inner plunger 10 in the high pressure chamber 25 .

A step part is provided above the inner plunger 10, and a partition wall 11 is placed here to form an oil discharge passage 22 separated from the reservoir chamber 18. A passage 20 is provided on the inner surface of the top wall of the cylinder body, and communicates the oil discharge passage 22 with the oil introduction chamber 17. The partition wall 11 has a spherical surface 11' with a radius R,
A hole 23 is provided at the top thereof to communicate the reservoir chamber 18 and the oil discharge passage 22, and a discharge hole 24 is provided in the top wall of the cylinder body 5 to communicate the oil discharge passage 22 with the outside. To limit the flow from holes 23 and 24, an arcuate tongue 1 of radius R is provided.
Metering plate 12 with 2' arranged in the gap between both holes
are arranged on the peripheral edge of the partition wall 11. code 8
is a stopper for preventing the outer plunger from slipping out from the cylinder inner tube 7, and is fitted into the outer circumferential groove of the outer plunger.

During operation, when the valve 3 is opened according to the movement of the cam 2, the load of the valve spring is transmitted to the outer plunger 9, and high pressure is generated in the high pressure chamber 25. At this time, a part of the oil in the high pressure chamber leaks out from the gap between the inner plunger 10 and the outer plunger 9, and the outer plunger 9 is slightly displaced with respect to the inner plunger 10 by that amount.

Next, when the valve closes, the return spring 13
When a restoring force is applied to the outer plunger 9 and it is displaced, and the pressure in the high pressure chamber 25 becomes lower than that in the reservoir chamber 18, the check valve 14 opens and oil flows from the reservoir chamber 18 into the high pressure chamber 25 and into the reservoir chamber 18. through the oil supply port 19 to the oil introduction chamber 17
From there, oil is supplied from the cylinder head oil circuit 4 to the oil introduction chamber 17 through the oil supply hole 16.

When the engine is stopped, all of the oil in the oil introduction chamber 17 flows out, and in some cases, some of the oil in the reservoir chamber 18 also flows out. When the engine starts, oil is supplied from the engine oil circuit 4, but at this time,
Air in the oil introduction chamber 17 flows into the oil discharge passage 22 through the passage 20, while air in the reservoir chamber 18 flows into the oil discharge passage 22 through the hole 23.
It is discharged to the outside through the discharge hole 24.

The same applies to the movement of air bubbles contained in the feed oil during engine operation. At this time, the bubble concentration of the oil flowing into the oil supply port 19 is lower than the bubble concentration of the oil passing through the passage 20, and the bubble concentration of the oil passing through the check valve 14 in the reservoir chamber 18 is lower than that in the hole 23. Oil with extremely low bubble concentration can be supplied to the high pressure chamber. Since the flow rate of oil discharged from the hole 23 is restricted by the metering plate 12, the inside of the reservoir is not stirred to a large extent.

As described above, according to the present invention, the oil discharge passage separated from the reservoir chamber by the partition wall is formed in the upper part of the inner plunger, and the air in the oil introduction chamber is guided to this oil discharge passage, and the air in the reservoir chamber is Since the oil is guided to the oil discharge passage through the hole provided in the partition wall and discharged to the outside from the discharge hole, the bubbles can be removed reliably and easily. In addition, since the flow rate of oil flowing out from the reservoir chamber through the hole in the partition wall is considerably restricted, it is possible to effectively prevent the generation of vortices and agitation of air bubbles in the reservoir chamber, and therefore oil with few air bubbles can be prevented. can be supplied to the hyperbaric chamber.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a hydraulic valve gap adjustment device according to the present invention, FIG. 2 is a perspective view of a partition wall attached to the device, and FIG. 3 is a perspective view of a metering plate. 1...Cylinder head, 5...Cylinder body, 6
... Inner lid, 7... Cylinder inner tube, 12... Metering plate, 11... Partition wall, 9... Outer plunger, 10
...Inner plunger, 13...Return spring, 14...Check valve, 17...Oil introduction chamber, 18...
Reservoir chamber, 19... Oil supply port, 20... Passage, 22
...Oil drain passage, 23...hole, 24...oil drain hole.

Claims (1)

[Scope of utility model registration request] A cylinder body is slidably fitted into the engine cylinder head, an outer plunger is slidably fitted into the cylinder inner cylinder extending upward from the inner lid of the cylinder body, and a reservoir is fitted into the outer plunger. an inner plunger forming a chamber; a high pressure chamber formed between the outer plunger and the inner plunger and communicating with the reservoir chamber via a check valve; In a hydraulic valve gap adjustment device, the inner plunger is provided with an oil supply port that communicates the oil introduction chamber and the reservoir chamber in the cylinder body, and , an oil discharge passage separated from the reservoir chamber by a partition wall is formed, a passage for communicating the oil introduction chamber and the oil discharge passage is formed on the inner surface of the top wall of the cylinder body, and the reservoir chamber and the oil discharge passage are connected to each other. , a communicating hole is provided in the partition wall, and an oil drain hole is provided in the top wall of the cylinder body opposite to the hole,
A hydraulic valve gap adjustment device for an internal combustion engine, characterized in that a metering plate is arranged between the hole in the partition wall and the oil discharge hole.