JPH0617613A - Locker arm mounting structure - Google Patents

Abstract

PURPOSE:To facilitate mouning of a locker arm having a hydraulic lash adjuster (hereinafter referred to as HLA) on a cylinder head in a valve system of an engine. CONSTITUTION:A guide part 19 is formed on a boss part 18 of a locker arm 12. A locker shaft 6 is inserted into the boss part 18, and a spring 8 is coiled around the locker shaft 6. The spring is compressed and the tip of the gide part 19 is brought into contact with the end surface of a bearing part 2 of a cam shaft 3 provided in the center part of the cylinder head 1, and the tip of a bolt 7 is screwed into the bearing part 2. When the bolt 7 is tightened, the guide part 19 is guided along the end surface of the bearing part 2, and the locker arm 12 is moved. The HLA mounted on the valve side of the locker arm 12 lifts the valve, and the locker arm 12 is mounted on the specified position. Since the locker arm 12 is guided to the end surface of the bearing part 2 by the guide part 19, it is unnecessary to compress the spring when the bolt is tightened, and mounting of the locker arm 12 on the cylinder head 1 is facilitated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rocker arm mounting structure for an automobile engine or the like.

[0002]

2. Description of the Related Art In a valve operating system for an engine, one end of a rocker arm rotatably supported by a rocker shaft inserted through an intermediate portion is brought into contact with a cam and the other end is brought into contact with a valve. However, there is one in which the rocker arm is rotated by the rotation of the cam to open and close the valve.

A conventional rocker arm mounting structure in this type of valve operating device will be described with reference to FIG. It should be noted that FIG. 9 shows a state before the rocker arm is attached to the cylinder. As shown in FIG. 9, a camshaft 3 is rotatably supported by the bearing portion 2 of the cylinder head 1. The rocker arm 5 that contacts the cam 4 of the camshaft 3
A rocker shaft 6 that rotatably supports the rocker shaft 6 is inserted in the middle part of the rocker shaft 6. A bolt 7 is pierced through the rocker shaft 6 in the radial direction thereof, and the bolt 7 serves as the bearing portion 2.
The rocker shaft 6 is fixed to the cylinder head 1 by being screwed onto the cylinder head 1.

A spring 8 for urging the rocker arm 5 in the axial direction is wound around the rocker shaft 6, and the rocker arm 5 is brought into contact with the bearing portion 2 by the elastic force of the spring 8 to be positioned. It has become. In the figure, 9 is a washer.

The rocker arm 5 is attached to the cylinder head 1 in the following manner. As shown in FIG. 9, first, the rocker arm 5, the bolt 7, the spring 8 and the washer 9 are assembled to the rocker shaft 6, and the tip of the bolt 7 is screwed into the bearing 2. Next, the spring 7 is compressed and the bolt 7 is tightened so that the rocker arm 5 does not interfere with the bearing portion 2.
Fixed to.

[0006]

By the way, in the above valve operating system, the adjusting screw is provided at the contact portion of the rocker arm with the valve so as to adjust the valve clearance. In addition, the hydraulic lash adjuster (hereinafter,
HLA) is provided to automatically maintain the valve clearance at zero by hydraulic pressure, thereby eliminating the need to adjust the valve clearance.

In the rocker arm provided with the adjusting screw, the rocker arm can be mounted on the cylinder head without lifting the valve by loosening the adjusting screw so as to maximize the valve clearance.

However, if the rocker arm is provided with the HLA, the valve clearance cannot be increased due to the structure of the HLA. Therefore, when the rocker arm is mounted on the cylinder head, the rocker arm is pressed against the elastic force of the valve spring. Need to lift the valve. Therefore, in the rocker arm mounting structure as shown in FIG. 9, when the rocker arm 5 is mounted on the cylinder head 1, the rocker arm 5 is pressed against the valve (not shown).
Needs to be lifted against the elastic force of the valve spring (not shown), and the spring 8 must be compressed so that the rocker arm 5 and the bearing portion 2 do not interfere with each other. is there.

The present invention has been made in view of the above points, and an object thereof is to facilitate attachment of a rocker arm having an HLA to a cylinder head.

[0010]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides an intermediate portion of a rocker arm, one end of which abuts on a cam and the other end of which abuts on a valve via a hydraulic lash adjuster. A rocker shaft around which a spring is wound is inserted, and the rocker shaft is attached to the bearing portion of the cylinder head by a bolt that penetrates the rocker shaft in the radial direction.
In a rocker arm mounting structure of an engine in which the rocker arm is brought into contact with the bearing portion by the elastic force of the spring to perform axial positioning of the rocker arm, an end surface of the rocker arm that comes into contact with the bearing portion is provided with an end surface of the bolt. It is characterized in that a guide portion is formed by extending to the tip side of the bolt along the axial direction.

[0011]

With this structure, the tip of the guide portion of the rocker arm is brought into contact with the end surface of the bearing portion,
When the tip portion of the bolt is screwed into the bearing portion and the bolt is further tightened, the guide portion is guided along the end surface of the bearing portion and the rocker arm is positioned at a predetermined position.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. The present embodiment is different from the conventional example shown in FIG. 9 only in the rocker arm, and therefore the same members as those in FIG. 9 are designated by the same reference numerals.

As shown in FIGS. 1 to 4, the camshaft 3 is attached to the bearing portion 2 provided at the center of the cylinder head 1.
Is rotatably supported, and intake / exhaust valves 10 and 11 are provided on both sides of the camshaft 3. In this embodiment, the supply / exhaust valves 10 and 11 are configured in the same manner, so the valve 10 side will be described below.

A pair of rocker shafts 6 extending in parallel along the axial direction of the camshaft 3 are provided above the camshaft 3. The rocker shaft 6 is inserted through an intermediate portion of the rocker arm 12 and rotatably supports the rocker arm 12. The rocker shaft 6 is fixed to the cylinder head 1 by screwing a bolt 7 that penetrates the rocker shaft 6 to the bearing portion 2. A roller is attached to one end of the rocker arm 12.
13 is mounted, the roller 13 is in contact with the cam 4 of the cam shaft 3, and the HLA 14 is mounted on the other end of the HLA 14.
14 is in contact with valve 10. A spring 8 for axially urging the rocker arm 12 is wound around the rocker shaft 6, and the rocker arm 5 is positioned in contact with the bearing portion 2 by the elastic force of the spring 8. In the figure,
Reference numerals 15 and 16 are valve springs for urging the valves 10 and 11 in the closing direction, and 17 is a cylinder head cover.

As shown in FIGS. 5 to 8, the boss portion 18 of the rocker arm 12 into which the rocker shaft 6 is inserted has an end portion that abuts the bearing portion 2 of the boss portion 18 penetrated through the rocker shaft 6 in the axial direction. A guide portion 19 is formed so as to extend to the tip side along the. As shown in FIG. 2, the guide portion 19 extends to the vicinity of the tip of the bolt 7 inserted into the rocker shaft 6.

The operation of the present embodiment configured as described above will be described below.

The rocker arm 12 is attached to the cylinder head 1 as follows. First, as shown in FIG.
The rocker arm 12, the bolt 7, the spring 8, and the washer 9 are assembled to the rocker shaft 6. Then, as shown in FIG. 1, the roller 13 of the rocker arm 12 is opposed to the cam 3, the HLA 14 is opposed to the valve 10, and the spring 8 is compressed so that the tip of the guide portion 19 is brought to the axial end surface of the bearing portion 2. The tip portion of the bolt 7 is screwed onto the bearing portion 2 in the state of abutting.
Next, when the bolt 7 is tightened, the guide portion 19 is guided along the end surface of the bearing portion 2 and the rocker arm 12 moves toward the valve 10 and the cam 4 side. Then, the roller 13 of the rocker arm 12 contacts the cam 4, and the HLA 14 lifts the valve 10 against the elastic force of the valve spring 15. In this way, the rocker shaft 6 is attached to the bearing portion 2, and the rocker arm 12 is mounted at a predetermined position.

As described above, the rocker arm 12 has the guide portion.
Since it is guided to the end face of the bearing portion 2 by 19, the bolt 7
When tightening, the spring 8 does not need to be compressed and the rocker arm 12 can be easily attached to the cylinder head 1.

Since the guide portion 19 is formed integrally with the boss portion 18 of the rocker arm 12, the number of parts does not increase and the structure is simple as compared with the conventional one.
The reliability of the valve train does not deteriorate, and the manufacturing cost does not increase. Further, in the present invention, since no jig is required, it is not necessary to prepare the jig when overhauling the valve operating device in the market. Further, since the guide portion 19 is provided on the boss portion 18 near the center of rotation of the rocker arm 12, the increase in the moment of inertia of the rocker arm 12 is small and the influence on the operation of the valve gear is small.

[0020]

As described in detail above, according to the present invention, by forming the guide portion on the rocker arm, the tip of the guide portion of the rocker arm is brought into contact with the end surface of the bearing portion,
When the tip portion of the bolt is screwed into the bearing portion and the bolt is further tightened, the guide portion is guided along the end surface of the bearing portion and the rocker arm is positioned at a predetermined position. As a result, it is possible to easily attach the rocker arm to the cylinder head without pressing the spring when the bolt is tightened.

[Brief description of drawings]

FIG. 1 is a front vertical sectional view showing a state before mounting a rocker arm according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of the apparatus shown in FIG.

3 is a front vertical sectional view showing a state after mounting the rocker arm in the apparatus of FIG. 1. FIG.

FIG. 4 is a vertical cross-sectional view of the side surface of FIG.

5 is a front view of a rocker arm of the device of FIG.

6 is a vertical cross-sectional view taken along the line AA of FIG.

FIG. 7 is a plan view of the rocker arm shown in FIG.

FIG. 8 is a rear view of the rocker arm shown in FIG.

FIG. 9 is a front longitudinal sectional view showing a state before mounting the rocker arm in the conventional rocker arm mounting structure of the engine.

[Explanation of symbols]

 2 Bearing part 4 Cam 6 Rocker shaft 7 Bolt 8 Spring 10 Valve 11 Valve 12 Rocker arm 14 HLA 19 Guide part

Claims (1)

[Claims] 1. A rocker shaft wound with a spring is inserted into an intermediate portion of a rocker arm, one end of which is in contact with a cam and the other end of which is in contact with a valve via a hydraulic lash adjuster. In a rocker arm mounting structure for an engine, the rocker arm is mounted on a bearing portion of a cylinder head with a bolt penetrating in a direction, and the rocker arm is brought into contact with the bearing portion by elastic force of the spring to axially position the rocker arm. ,
A rocker arm mounting structure characterized in that a guide portion is formed by extending an end surface of the rocker arm that abuts on the bearing portion along the axial direction of the bolt to the tip side of the bolt.