JPH0467003B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic valve gap correction device for a valve operating system for an internal combustion engine, which has a hydraulic lash adjuster that automatically corrects the valve gap using hydraulic pressure and elastic force of an elastic member.

It is extremely important to reduce the weight of a hydraulic latch adjuster in order to maintain good dynamic characteristics of the valve mechanism, especially when it is incorporated into an overhead cam type internal combustion engine. At the same time, efforts were made to minimize the volumes of the high-pressure chamber and oil reservoir chamber that house oil.

By the way, when the engine is stopped, oil leaks from the lash adjuster, so when the engine is restarted, there is not enough oil and a large amount of air is sucked in, making it impossible for the lash adjuster to function properly. There's a problem.

In order to solve this problem, the present invention aims to provide a new valve gap automatic correction device that can recover oil leaked during stoppage into an oil reservoir chamber and prevent a situation where the oil amount is insufficient. An automatic valve gap correction device using a hydraulic lash adjuster with a separate oil sump chamber will be described below with reference to the drawings.

In FIG. 1, the body 11 of the hydraulic lash adjuster 1 is a bottomed hollow cylinder having a closed end 11a at the top and an open end 11b at the bottom. It has a portion 12a extending to. The high pressure chamber 13 is formed between the closed end 11a of the body 11 and the plunger 12, and the elastic body 14 is located within the high pressure chamber 13 so as to bias the plunger 12 outward from the body 11. . An oil hole 15 for introducing oil from the outside is provided in the body closed end 11a. A check valve 16 and a check valve cage 17 for controlling the opening and closing of the oil hole 15 are provided within the high pressure chamber. As shown in FIG. 2, this hydraulic lash adjuster 1 is arranged so as to fit into a lash adjuster support hole 21 provided in a rocker arm 2, and an oil reservoir is located adjacent to the lash adjuster support hole 21 in the upper part of the support hole 21. 3 is provided. The closed end 11a of the body 11 of the latch adjuster 1 is connected to the oil reservoir chamber 3.
It is placed facing to the side. In this configuration, when the engine is stopped, the oil in the oil reservoir chamber 3 is drained into the gap 21a between the body 11 and the support hole 21, as shown in FIG.
leaks from. When the valve is open or stopped, the force of a valve spring (not shown) acts on the plunger 12, so the plunger 12 moves from its stop position and contracts into the body 11. Therefore, the volume inside the high pressure chamber 13 is reduced, so that the oil in the chamber is distributed between the inner periphery of the body 11 and the plunger 12.
It leaks from the gap 11c with the outer periphery. When the engine is restarted from this state, the plunger 12 will eventually return to the position at which it stopped, but at this time, oil will leak, so if the amount of oil in the oil sump chamber 3 is insufficient, the oil mixed with air will be transferred to the oil sump chamber 3. This leads to suction into the high pressure chamber 13. As a result, the high pressure chamber 1 containing a large amount of air bubbles
The oil in the valve 3 causes an extreme decrease in rigidity, and there is a risk that the valve will not be able to function properly.

The present invention is aimed at avoiding the occurrence of such problems, and in order to prevent the amount of oil from decreasing in the oil reservoir chamber 3, the oil leaking from the oil reservoir chamber 3 and the high pressure chamber 13 is reliably drained into the oil reservoir chamber 3. The present invention aims to provide an automatic valve gap correction device having a novel structure and having an oil return path that can always supply an appropriate amount of oil to the high pressure chamber 13 by returning the required amount of oil to the high pressure chamber 13. Figure 4 ~ 1st
FIG. 1 shows an embodiment of the present invention. Figure 4A,
B and C are for example O on the inner and outer peripheries of the body 11.
- Providing sealing materials such as rings 18a and 18b to prevent oil loss, and providing circumferential grooves 21a and 21b at positions directly above them, respectively, and communicating these circumferential grooves on the inner and outer circumferences through oil holes, and ,
A spiral groove 11c starting from a circumferential groove on the outer periphery and a groove 11d on the top surface of the body are provided. 5A and 5B show a case where the outer periphery of the body is formed into a vertical groove 11e in the configuration shown in FIG. 4. 6A and 6B, for example, a rubber boot 4 is provided between the lower end 21b of the rocker arm support hole 21 and the open end 12a of the plunger 12, and the leaked oil is collected there. one or more spiral grooves 11c
It is now being collected by A case where this groove is made into a vertical groove 11e is shown in FIGS. 7A and 7B. In addition, in FIGS. 8A and 8B, similar to the configuration shown in FIGS. 6 and 7, a boot 4 for catching oil leakage is provided, and the recovery of the leaked oil accumulated here into the oil sump chamber 3 is supported. This is an example in which a vertical groove 5a is provided in a sleeve 5 that is fitted into an inner periphery 21a of a hole 21. 9A and 9B are examples in which the groove shape is a spiral groove 5b in the configuration of FIG. 8. In the above example, the boot 4 used can be easily attached to the support hole 21 and the plunger 12 by baking or other means.

The detailed explanation so far has been about a configuration in which the hydraulic latch adjuster is arranged adjacent to the oil sump chamber provided in the rocker arm, but depending on how it is used, the oil sump chamber may be provided separately. , or may be constructed integrally with the hydraulic lash adjuster. 10A and 10B show an example of a combined body in which an oil reservoir chamber member 3' provided separately is combined with a hydraulic lash adjuster 1, and in this configuration, the fourth
The embodiments shown in FIGS. 9 to 9 can be applied as they are. Note that this figure is an example corresponding to FIG. 7. 11A and 11B show a structure in which the oil reservoir chamber member 3' shown in FIG. 10 is integrated with the hydraulic lash adjuster 1 and the body 11, and in this structure, the oil reservoir chamber member 3' shown in FIG. The embodiment shown in FIG. 9 can be applied as is. Note that this figure is an example corresponding to FIG. 6.

In this way, the present invention provides a means for preventing oil leakage and a means for recovering leaked oil between the body and the plunger, thereby making it possible to secure the required amount of oil. This solves the problem of malfunction during restart after restarting, and at the same time allows the oil sump chamber to be formed to the minimum required size.
Together with the rocker arm and the hydraulic lash adjuster, it can have a great effect in contributing to reducing the weight of the valve train. Incidentally, the volume of the oil reservoir chamber of the latch adjuster of the present invention is 1/2 to 2/3 of the volume of the oil reservoir chamber of the conventional latch adjuster with oil leakage.
It is known that it can be made smaller to a certain degree. The above-mentioned feature of the device configuration is that it is versatile enough to be widely used in lash adjuster configurations other than the examples described herein, and its industrial effects are extremely large.

[Brief explanation of the drawing]

Figures 1 to 3 are sectional views for explaining the conventional example;
Figures 1 to 11 are cross-sectional views, side views, etc. showing embodiments of the present invention. The symbols in the drawings indicate the following members, respectively. 1...
Hydraulic latch adjuster, 2... Locker arm, 3... Oil sump chamber, 4... Boot, 5... Sleeve, 11... Body, 12... Plunger, 13
... High pressure chamber, 14 ... Elastic body, 15 ... Oil hole, 1
6...Check valve, 17...Check valve cage, 18...O-ring, 21...Support hole.

Claims (1)

[Scope of Claims] 1. A bottomed hollow cylindrical body having an oil hole at the bottom; a plunger slidably fitted into the body to form a high pressure chamber between the inner surface of the bottom;
an elastic body provided in the high pressure chamber and urging the plunger to move away from the body toward the open end;
A hydraulic latch adjuster is also provided in the high pressure chamber and includes a check valve for controlling opening and closing of the oil hole, and a check valve cage for holding the check valve, and the body is connected to the support hole of the rocker arm through the oil reservoir chamber. The outer end of the plunger is supported by a valve head and the outer end of the plunger is brought into contact with the valve head. An automatic valve gap correction device characterized in that an oil return passage communicating with the oil reservoir chamber is provided in a gap between the support hole and the outer peripheral surface of the body. 2 Circumferential grooves provided on the inner and outer peripheries of the body, one or more spiral grooves starting from the circumferential grooves on the outer periphery, as oil circulation passages communicating with the sealing member and the oil reservoir chamber; An oil hole is provided that communicates the circumferential grooves on the inner and outer peripheries, and a groove is provided at the top of the body that communicates the spiral groove with the oil reservoir chamber. The automatic valve gap correction device according to claim 1, characterized in that O-rings are provided on the periphery and the outer periphery. 3 Circumferential grooves provided on the inner and outer peripheries of the body, one or more vertical grooves starting from the circumferential grooves on the outer periphery, as oil circulation passages communicating with the sealing member and the oil reservoir chamber; Oil holes that connect the circumferential grooves on the inner and outer peripheries,
and a groove at the top of the body that communicates the longitudinal groove with the oil reservoir chamber, and O-rings are provided on the inner and outer circumferences of the body at positions closer to the opening end than the circumferential grooves on the inner and outer circumferences. An automatic valve gap correction device according to claim 1. 4. One or more spiral grooves provided on the outer periphery of the body from the open end to the closed end as an oil circulation path communicating with the seal member and the oil reservoir chamber, and a body that communicates the spiral groove with the oil reservoir chamber. The valve gap automatic according to claim 1, further comprising a groove at the top and a boot-shaped sealing member connecting the entire circumference of the opening end of the plunger and the entire circumference of the opening end of the support hole. correction device. 5. One or more vertical grooves provided on the outer peripheral surface of the body from the open end to the closed end as an oil circulation path communicating with the sealing member and the oil reservoir chamber, and communicating the vertical groove with the oil reservoir chamber. A groove is provided at the top of the body,
2. The automatic valve gap correction device according to claim 1, further comprising a boot-shaped sealing member connecting the entire circumference of the opening end of the plunger and the entire circumference of the opening end of the support hole. 6. The body has no grooves on the outer periphery, and a sleeve having one or more vertical grooves along the entire length on the inner periphery is fitted between the body and the support hole. An automatic valve gap correction device according to claim 1. 7. A patent characterized in that the body has no grooves on its outer periphery, and a sleeve having one or more spiral grooves on its inner periphery over its entire length is fitted between the body and the support hole. An automatic valve gap correction device according to claim 1. 8. The valve gap automatic correction according to claim 1, characterized in that a combined body is formed by combining the body and an oil reservoir provided separately, and the combined body is fitted into the support hole. Device. 9. The automatic valve gap correction device according to claim 1, wherein an oil reservoir is formed integrally with the body, and the integrated body and oil reservoir are fitted into the support hole.