JPH0350246Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field The present invention is a hydraulic lash adjuster that automatically corrects the valve gap in a valve train of an internal combustion engine using hydraulic pressure and the elastic force of an elastic member. This invention relates to an improvement in a hydraulic latch adjuster used in a pressurized direct-acting valve mechanism.

Conventional Technology In general, as part of efforts to make internal combustion engines smaller and lighter, hydraulic lash adjusters need to be housed in limited installation locations without taking up a lot of space. Efforts are being made to make the thickness close to the limit necessary to maintain this.

FIG. 6 shows a conventional example of a hydraulic lash adjuster in a direct-acting valve mechanism. The lash adjuster 3 inserted between the cam 1 and the valve 2 is
The upper end of the built-in plunger 3a is positioned by being slidably fitted into the center hole 5a of the bucket 5 which is slidably fitted into the support hole 4a of the cylinder head 4. comes into contact with
The lower end surface of the body 3b is configured to abut against the shaft end surface of the valve 2. The hydraulic oil guided to the oil supply groove 4b provided on the inner circumferential surface of the cylinder head 4 passes through a circumferential groove 5c provided on the outer circumferential surface of the bucket 5, an oil hole 5d, and then passes through the inner surface of the bucket 5, the body 3b, and the plunger 3a. The oil is fed to the oil reservoir chamber 7 where the oil is stored. 8 is a valve spring, and 9 is a valve seat.

Problems to be solved by the invention In the conventional example, since it is formed as an integral bucket structure, each part is divided into two parts, the cylindrical part and the top plate part, and then the two parts are welded and joined together. It is molded. Since the cylindrical part is a multifaceted structure consisting of an outer cylinder part, an inner cylinder part, and a part connecting the two parts, many steps are required to form the cylinder part. This invention first focuses on the above-mentioned problems and attempts to provide a hydraulic latch adjuster using a bucket belt that is inexpensive and lightweight by reducing the number of manufacturing steps. The second objective is to provide a stable structure that does not suffer from wear by eliminating sliding parts. That is, in the conventional structure, the space between the center hole 5a of the bucket 5 and the body 3b is a sliding surface, but this fitting structure is eliminated and a structure without a sliding part is provided. be.

Means for Solving the Problems In order to achieve the above object, the present invention simplifies the shape of the bucket to include only the top plate and the outer cylinder, and connects the inner peripheral surface of the bucket to the body of the latch adjuster. A flexible diaphragm is stretched between the two. That is, as shown in FIG. 1, the bucket bag 5 is composed of only a top plate and an outer cylinder, and a flexible diaphragm 6 is stretched between the inner peripheral surface of the bag bag 5 and the body 3b. The centering and fixing means for the lash adjuster 3 in this case is shown in FIGS. 2 and subsequent figures.

Function The relative movement between the movement of the bucket in conjunction with the action of the cam and the movement of the body in conjunction with the action of the valve takes place only inside the adjuster, and the diaphragm only expands and contracts depending on the positional relationship between the body and the bucket. Therefore, there are no sliding parts, and therefore there are no sliding problems such as galling or causes of wear.
Furthermore, the problem of oil leakage through sliding parts is also eliminated. Furthermore, the simplified structure simplifies the manufacturing process, and since the inner circumferential surface of the bucket cylinder part and the outer circumferential surface of the body do not require high machining accuracy, it can greatly contribute to reducing the number of manufacturing steps.

Embodiment Figure 1 shows an example of the implementation of the present invention, in which 1 is a cam, 2 is a valve, 3 is a latch adjuster, 4 is a cylinder head, 5 is a bucket, 6 is a diaphragm, and 7 is an oil sump chamber. , 8 is a valve spring, and 9 is a valve seat.
The latch adjuster 3 consists of a plunger 3a and a body 3b that are slidably fitted together, a retainer 3c inside the body 3b, and a check valve 3d supported by a spring, and a high pressure chamber 3e formed inside the body 3b.
Lush adjustment is performed by hydraulic pressure.

FIG. 2 explains the details of the centering and fixing means in the embodiment shown in FIG. The one for centering and positioning, also shown in FIG. 3, is a holder 10 that fits both the lower end of the body 3b and the valve shaft 2a.
Positioning is performed using

FIG. 4 shows another embodiment, in which the body 3b
The lower end of the valve spring 8 is made into a cylindrical shape, and the holder 10 of FIG. 3 is omitted by fitting the valve shaft 2a, and FIG.
The holder 6 is omitted by providing a guide portion 11a on the upper surface of the body 3b and fitting it with the body 3b.
2 is Kotsuta.

Effects of the invention The bucket is not provided with a sliding part that fits with the latch adjuster, and a flexible connection structure is used with a diaphragm interposed between the latch adjuster body and the bucket, so that the support member of the adjuster and the adjuster body The sliding wear part between the parts is eliminated, resulting in stable quality and a longer lifespan.The simplified structure also reduces manufacturing man-hours, reducing costs and improving the production process for this type of product. The economic effects are extremely large.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing one example of implementing the present invention;
5 to 5 are enlarged sectional views of essential parts, and FIG. 6 is a sectional view of a conventional example. The symbols in the drawings indicate the following members, respectively. 1...
Cam, 2... Valve, 3... Latch adjuster, 3
a...Plunger, 3b...Body, 4...Cylinder head, 5...Bucket, 6...Diaphragm, 7...Oil reservoir chamber, 8...Valve spring, 9...Valve seat,
10...Holder, 11...Retainer, 12...Kotta.

Claims (1)

[Claims for Utility Model Registration] 1. In a bucket consisting of an outer cylindrical part that slidably fits into the support hole of the cylinder head and a top plate part that contacts the cam, between the top plate part and the valve. A latching adjuster is provided between the latching adjuster and the latching adjuster, a flexible diaphragm is provided between the inner circumferential surface of the outer cylindrical portion and the body of the latching adjuster, and the sliding portion of the latching adjuster is A structure of a direct-acting hydraulic lash adjuster characterized by using a centering fixing means that does not contain any centering. 2. As the means for fixing the centering of the lash adjuster, a protrusion or a hole for fixing the centering that fits with the plunger of the lash adjuster is provided on the lower surface of the top plate of the bucket. A structure of a direct-acting hydraulic lash adjuster according to claim 1 of the utility model registration claim. 3. The utility model registration claim No. 3 is characterized in that the centering fixing means for the lash adjuster is provided with a centering holder that fits into the lower end of the body of the lash adjuster and the upper end of the valve shaft. 1
The structure of the direct-acting hydraulic lash adjuster described in . 4. Claims for registration of a utility model characterized in that, as the centering and fixing means for the lash adjuster, the end of the body of the lash adjuster is formed into a cylindrical shape that engages and aligns the end of the shaft of the valve shaft. 1st
The structure of the direct-acting hydraulic lash adjuster described in . 5. A request for registration of a utility model characterized in that, as a means for centering and fixing the lash adjuster, a guide portion is formed on the upper part of the valve spring retainer and engages with the lower end of the body of the lash adjuster for centering. The structure of the direct-acting hydraulic lash adjuster according to item 1.