JP3301514B2 - Valve train - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve gear for driving a valve for intake and exhaust of an engine.

[0002]

2. Description of the Related Art Conventionally, a four-valve overhead cam (OH)
In the diesel engine of the type C), as a valve operating device for driving intake and exhaust valves, for example, a Japanese Utility Model Laid-Open No. 2-50
No. 003 is known. FIG.
FIG. 1 shows a valve train of this type developed earlier by the present applicant. In this valve train, the rocker arm 15 fixed to the arm shaft 13 is swung by the rotation of the camshaft 11, and the rocker The adjustment screw 17 fixed to the arm 15 is moved up and down.

The bridge 21 is moved up and down via the cap 19 by the up and down movement of the adjusting screw 17, and a pair of intake valves (or exhaust valves) 23a and 23b fixed to both sides of the bridge 21 are moved up and down at the same time. You. A return spring 27 through which the upper portions of the valves 23a and 23b are inserted is disposed between both sides of the bridge 21 and the cylinder 25, and a pressing member 29 is disposed at an upper end of the return spring 27.

In the center of the bridge 21, a hole 21a is provided.
A guide pin 31 fixed to the cylinder 25 is inserted into the hole 21a. FIG. 4 shows an adjusting screw 1 fixed to one end of the rocker arm 15.
7 shows the details of the cap 7 and the cap 19. An adjusting screw 17 is screwed into a screw hole 15 a formed in the rocker arm 15 and fixed by a nut 33.

The tip of the adjusting screw 17 is formed in a spherical shape, and the spherical portion 17 a is fitted in a concave portion 19 a formed in the cap 19. In the concave portion 19a,
An annular groove 19b is formed, and the concave portion 1 is formed in the annular groove 19b.
A metal retaining ring 35 for preventing the spherical portion 17a from coming off from the 9a is fitted.

The rocker arm 15 has an oil passage 15b for guiding engine oil supplied from the lubricating oil pump via the arm shaft 13 to the screw hole 15a. Then, the engine oil guided to the screw hole 15a is transmitted through the adjusting screw 17, flows into the recess 19a through the opening of the retaining ring 35, and
The lubrication in a is performed.

[0007]

However, in such a valve train, a minute gap is formed between the concave portion 19a of the cap 19 and the spherical portion 17a of the adjusting screw 17, so that during operation, , Cap 1
There is a problem that a minute gap is formed between the bridge 9 and the bridge 21 and a tapping sound is generated.

The present invention has been made in order to solve such a conventional problem, and an object of the present invention is to provide a valve train capable of greatly reducing the occurrence of a tapping sound due to a collision between a cap and a bridge. Aim.

[0009]

According to the valve gear of the present invention, the tip of an adjusting screw fixed to the rocker arm is formed in a spherical shape, and the spherical portion is formed on a cap which is in contact with the upper surface of the bridge. In the valve gear, the annular groove is formed in the concave portion so as to be fitted with a seal ring for preventing the spherical portion from coming off from the concave portion, and the adjustment ring is formed by the seal ring.
Between the spherical portion of the screw and the recess of the cap
The enclosed space is formed in, on the adjusting screw, communicates with the first oil passage is formed at one end thereof to the rocker arm, a second oil communicating at the other end to the annular groove than the inner recess of the recess A passage is formed.

[0010]

In the valve gear of the present invention, the seal ring
A sealed space is formed between the spherical portion of the adjusting screw and the recess of the cap, and the sealed space is filled with engine oil that has passed through the first oil passage and the second oil passage. The cap is constantly pressed against the bridge.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows details of a main part of FIG.
FIG. 2 shows an embodiment in which the valve train of the present invention is applied to a 4-valve overhead cam type diesel engine.
In FIG. 2, reference numeral 41 indicates a rocker arm, and the rocker arm 41 is swingably supported by an arm shaft 43.

One side of the rocker arm 41 is provided with a roller 4
5 is rotatably supported, and a camshaft 47 is in contact with the roller 45. An adjust screw 49 is fixed to the other side of the rocker arm 41.
A cap 51 is fixed to a lower portion of the adjusting screw 49, and a lower end of the cap 51 is in contact with an upper surface of the bridge 53.

A hole 53a is formed in the center of the bridge 53, and a guide pin 57 fixed to the cylinder 55 is inserted into the hole 53a. On both sides of the bridge 53, a pair of intake valves (or exhaust valves) 59a, 59
The upper end of 9b is fixed. With both sides of the bridge 53,
A return spring 61 through which the upper parts of the valves 59a and 59b are inserted is disposed between the cylinder 55 and the cylinder 55, and a pressing member 63 is disposed at an upper end of the return spring 61.

FIG. 1 shows details of an adjustment screw 49 and a cap 51 fixed to one end of the rocker arm 41. The adjustment screw 49 is screwed into a screw hole 41a formed in the rocker arm 41.
It is fixed by a nut 65. The tip of the adjusting screw 49 is formed in a spherical shape.
Is fitted in a concave portion 51 a formed in the cap 51.

An annular groove 51b is formed in the concave portion 51a at a position corresponding to the neck of the spherical portion 49a. A seal ring 67 made of, for example, rubber, resin, or the like is fitted in the annular groove 51b. This seal ring 67
Functions to prevent the spherical portion 49a from coming out of the concave portion 51a and to form a closed space S between the spherical portion 49a and the concave portion 51a of the cap 51.

The rocker arm 41 has a first oil passage 41b for guiding engine oil from a lubricating oil pump supplied through an arm shaft 43 to a screw hole 41a. One end of the adjusting screw 49 communicates with the first oil passage 41b formed in the rocker arm 41, and the other end of the adjusting screw 49 has the annular groove 5 of the concave portion 51a.
A second oil passage 49b communicating with the concave portion 51a inside 1b is formed.

In the valve gear described above, the camshaft 47
The rocker arm 41 fixed to the arm shaft 43 is swung by the rotation of, and the adjustment screw 49 fixed to the rocker arm 41 is moved up and down. The bridge 53 is moved up and down via the cap 51 by the up and down movement of the adjusting screw 49, and a pair of intake valves (or exhaust valves) 5 fixed to both sides of the bridge 53.
9a and 59b are simultaneously moved up and down.

The engine oil supplied from the lubricating oil pump through the arm shaft 43 passes through the first oil passage 41b and the second oil passage 49b, and the spherical portion 49a of the adjusting screw 49 and the cap 51 are formed.
Is always supplied to the closed space S formed between the recess 51a. In the valve operating device configured as described above, the sealed space S is formed between the spherical portion 49 a of the adjusting screw 49 and the concave portion 51 a of the cap 51 by the seal ring 67.
Is formed.

The sealed space S is filled with the engine oil that has passed through the first oil passage 41b and the second oil passage 49b, and the oil pressure of the engine oil
The cap 51 is constantly pressed against the bridge 53. Therefore, the cap 51 and the bridge 5
The gap between the cap 51 and the bridge 53 does not occur, and the hitting sound due to the collision between the cap 51 and the bridge 53 can be significantly reduced.

In the above-described valve train, the cap 51 is supported by the seal ring 67.
It is possible to reliably prevent the cap 51 from falling off from the spherical portion 49a of the adjusting screw 49.

[0021]

As described above, in the valve gear of the present invention, a sealed space is formed between the spherical portion of the adjusting screw and the concave portion of the cap by the seal ring. The engine oil that has been filled through the oil passage and the second oil passage is filled, and the cap is constantly pressed against the bridge by the oil pressure of the engine oil. There is an advantage that it can be significantly reduced.

[Brief description of the drawings]

FIG. 1 is a side view showing details of an adjustment screw and a cap of FIG. 2;

FIG. 2 is a sectional view showing an embodiment of the valve train of the present invention.

FIG. 3 is a sectional view showing a conventional valve train.

FIG. 4 is a side view showing details of an adjusting screw and a cap of FIG. 3;

[Explanation of symbols]

 41 Rocker arm 41b First oil passage 49 Adjust screw 49a Spherical portion 49b Second oil passage 51 Cap 51a Recess 51b Annular groove 53 Bridge 67 Seal ring

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Claims (1)

(57) [Claims] 1. A valve actuating device in which a tip of an adjusting screw fixed to a rocker arm is formed in a spherical shape, and the spherical portion is fitted into a concave portion formed in a cap abutting on an upper surface of a bridge. in, in the recess, thereby forming an annular groove in which the seal ring is fitted for preventing escape of the spherical portion of the recess, before
The adjustment screw is provided by the seal ring.
Form a closed space between the spherical part and the concave part of the cap.
A second end of the adjusting screw communicating with a first oil passage formed in the rocker arm, and a second end communicating with a recess inside the annular groove of the recess.
A valve train characterized by forming an oil passage.