JPH0727363Y2 - Adjuster screw adjusting device for rocker arm - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an adjusting screw adjusting device for a rocker arm in a valve train of an internal combustion engine.

[Conventional technology]

Generally, valve clearance adjustment in a valve train of an internal combustion engine is performed by inserting a thickness gauge between the top end of the valve stem and the tip of the rocker arm in the closed state, and adjusting the screw clearance at the rear end of the rocker arm. The screw is tightened by using a tightening tool such as a screwdriver with the lock nut loosened, and the tappet at the lower end of the push lock is brought into close contact with the cam surface on the cam shaft.

[Problems to be solved by the device]

However, in a valve clearance adjusting device using such a thickness gauge, one operator inserts the thickness gauge into the tip side of the rocker arm with one hand while tightening the adjusting screw with the tightening tool with the other hand. However, there is a problem that workability is poor and work efficiency is reduced. Therefore, in order to eliminate the above-mentioned problems, only the rocker arm or both the rocker arm and the adjust screw, a rocker arm adjust screw adjusting device provided with a valve clearance adjusting scale is proposed in Japanese Utility Model Publication No. 55-36931. However, with this proposal, since the adjustment work must be performed while constantly observing the adjustment scale, there is a risk that the adjustment scale may not be accurately confirmed due to variations in the worker's posture, eye position, etc. There is a problem that the adjustment work becomes unsuitable when the lighting of the above is not sufficient or the operator's eyesight is weak.

The present invention was devised in order to solve the problems of the above-mentioned conventional device, and facilitates the adjustment work by eliminating the work of inserting the thickness gauge, and the adjustment work due to variations in the posture, eye position, etc. of the operator. An object of the present invention is to provide an adjusting screw adjusting device for a rocker arm which eliminates inaccuracy and can perform valve clearance adjusting work regardless of the lighting in the workplace and the visual acuity of a worker.

[Means for Solving the Problems]

In order to achieve the above object, the adjusting screw adjusting device for a rocker arm of the present invention has a plurality of clearance adjusting notches formed at equal intervals on an outer peripheral portion of a screw portion of an adjusting screw screwed to a rocker arm and elastically attached to the adjusting screw adjusting device. A locking pin that is biased to engage with the notch is embedded in the rocker arm.

[Action]

The operation of the rocker arm adjusting screw adjusting device of the present invention having the above construction is as follows.

That is, when adjusting the valve clearance, first loosen the lock nut 8 and then the adjusting screw 4
Tighten. By this operation, the adjusting screw 4 is brought into close contact with the upper end of the bush lock 5 while the tip 1a of the rocker arm 1 is in contact with the top of the valve stem 3, and a tabet (not shown) is brought into close contact with the cam. In this state, the valve clearance is zero. The adjusting screw 4 is returned and rotated in the loosening direction by the valve clearance determined here. This return rotation grips the engagement sound and the tightening tool with respect to the number of engagements of the tip 61 of the locking pin 6 and the notch 42 so as to secure a desired valve clearance from the state where the valve clearance is zero. This is performed while confirming the feel of the hand (moderation), and after the predetermined number of engagements has been reached, that is, after confirming that the predetermined valve clearance has been secured, the lock nut 8 is tightened to complete the valve clearance adjustment.

As described above, according to the adjuster screw adjusting device of the rocker arm of the present invention, it is possible to facilitate the adjusting work by eliminating the work of inserting the thickness gauge, and to make the adjusting work inaccurate due to variations in the posture of the worker, the position of the eyes, etc. And the valve clearance adjustment work can be performed regardless of the lighting of the workplace and the visual acuity of the worker.

〔Example〕

An embodiment of the rocker arm adjusting screw adjusting device of the present invention will be described below with reference to the drawings. Reference numeral 1 denotes a rocker arm in a valve mechanism of an internal combustion engine, which is rotatably fitted to a rocker shaft 2 and has a tip 1a adapted to press a valve stem 3 of an intake valve and an exhaust valve. Further, a valve clearance adjusting screw 4 is screwed into a screw hole 1c formed at the rear end 1b of the rocker arm 1, and the adjusting screw 4 is actuated by a cam on a cam shaft driven by a crank shaft (not shown). It is in contact with the upper end of the push rod 5 (partially omitted) that moves up and down.

A plurality of clearance adjusting notches 42 are formed on the outer circumference of the screw portion 41 of the adjusting screw 4 at equal intervals on the circumference thereof. That is, when the adjusting screw 4 is rotated from one notch 42 to the next notch 42, the adjusting screw 4 is displaced in the axial direction by a preset distance.

Further, a lateral hole 1d is formed horizontally in the rear end 1b of the rocker arm 1 so as to communicate from its outer end to the intermediate portion of the screw hole 1c, and a locking pin 6 is slidably incorporated therein.

The locking pin 6 has a tip 61 formed on the front end side thereof, and a flange 62 provided in the middle thereof.
The tip 61 is notched in the screw portion 41 of the adjusting screw 4 by being urged by the coil spring 7 interposed between the back surface of the 62 and the caulking portion 1e formed at the outer end portion of the lateral hole 1d. It is adapted to engage with 42. In addition,
The caulking portion 1e is formed by caulking after inserting the locking pin 6 and the coil spring 7 into the lateral hole 1d.

Further, 8 is a lock nut for fixing the adjusting screw 4 to the rocker arm after adjusting the valve clearance.

The operation of the adjusting screw adjusting device for the rocker arm of the present invention constructed as described above is as follows.

That is, when adjusting the valve clearance, first loosen the lock nut 8 and then the adjusting screw 4
Tighten. By this operation, the adjusting screw 4 is brought into close contact with the upper end of the push rod 5 while the tip 1a of the rocker arm 1 is in contact with the top of the valve stem 3, and the tappet (not shown) is brought into close contact with the cam. In this state, the valve clearance is zero. The adjusting screw 4 is returned and rotated in the loosening direction by the valve clearance determined here. This return rotation grasps the number of times of engagement between the tip 61 of the engaging pin 6 and the notch 42 and the engagement sound and the tightening tool so as to secure a desired valve clearance from the state where the valve clearance is zero. This is performed while confirming by the feel of the hand (moderation), and after the predetermined number of engagements has been reached, that is, after confirming that the predetermined valve clearance has been secured, the lock nut 8 is tightened to complete the valve clearance adjustment.

As described above, according to the adjuster screw adjusting device of the rocker arm of the present invention, it is possible to facilitate the adjusting work by eliminating the work of inserting the thickness gauge, and to make the adjusting work inaccurate due to variations in the posture of the worker, the position of the eyes, etc. And the valve clearance adjustment work can be performed regardless of the lighting of the workplace and the visual acuity of the worker.

[Effect of device]

As described above, the adjusting screw adjusting device for the rocker arm of the present invention has a plurality of clearance adjusting notches formed at equal intervals on the outer peripheral portion of the screw of the adjusting screw screwed to the rocker arm, and is elastically biased. Since the locking pin that engages with the notch is embedded in the rocker arm, the work of inserting the thickness gauge is not required, and the adjustment work is facilitated.
There is an effect that the inaccuracy of the adjustment work due to the variation in the position of the eyes and the like can be eliminated, and the valve clearance adjustment work can be performed regardless of the lighting in the work place and the visual acuity of the worker.

[Brief description of drawings]

FIG. 1 is a side view showing a rocker arm and its related parts according to an embodiment of the present invention, FIG. 2 is an enlarged side view of an essential part shown by partially breaking the rocker arm, and FIG. 3 is embedded in the rocker arm. 4 is a perspective view showing a locking pin, FIG.
The figure is an enlarged cross-sectional view of the main part of the rocker arm. 1 ... Rocker arm, 2 ... Rocker shaft 3 ... Valve stem 4 ... Adjusting screw 5 ... Push rod, 6 ... Locking pin 7 ... Coil spring, 8 ... Lock nut 41 ... Thread part, 42 ...... Notch

Claims (1)

[Scope of utility model registration request] 1. A plurality of clearance adjusting notches are formed at equal intervals on an outer peripheral portion of a screw portion of an adjusting screw screwed to a rocker arm, and locking pins which are elastically biased to engage with the notches are provided. An adjusting screw adjusting device for a rocker arm, which is embedded in the rocker arm.