JP2002115512A - Valve clearance setting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a valve clearance setting device capable of accurately setting valve clearance by controlling fastening torque by a very small value. SOLUTION: A cylindrical first driving shaft 2 is ratatably arranged in a body 1, and an outside socket 15 is installed on the tip 2a so as to be capable of freely advancing and retreating. A second driving shaft 11 is arranged inside the first driving shaft 2, and an inside socket 18 is installed on the tip 11a so as to be capable of freely advancing and retreating. Rotational output of a first air motor 5 is transmitted to the first driving shaft 2 via a planetary gear mechanism 6 and a gear train 13. Reaction when the planetary gear mechanism 6 makes output is received by a plate-like member 8 via a transmission member 7 extending to the radial directional outside. The plate-like member 8 is fixed to the body 1, and is attached with a strain gauge 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve clearance setting device used for setting a valve clearance.

[0002]

2. Description of the Related Art As shown in FIG. 3, a valve train of an engine is provided with a push rod 31 and a rocker arm 33 driven by the push rod 31 to drive a valve 32 of an intake and exhaust system. I have. This rocker arm 33
A small gap, that is, a valve clearance C, is provided between the valve 32 and the valve 32. This valve clearance C is provided by a bobbin 35 screwed to the stud bolt 34.
It is adjusted by tightening and loosening. The pivot 35 is fixed by tightening a lock nut 36.

Conventionally, setting the valve clearance C 1
As one of the methods, there is a method in which an operator inserts a clearance gauge between the rocker arm 33 and the valve 32, and sequentially tightens the pivot 35 and the lock nut 36.

[0004]

Since the valve clearance C is 70 μm to 130 μm, it is necessary to control the tightening torque of the pivot 35 with a very small value. However, in the above method, the operator is
Since the tightening torque of No. 5 is adjusted while estimating it with the sense of a hand, it is difficult to manage the tightening torque of the pivot 35 with a small value, and there is a problem that an error is likely to occur in the valve clearance C.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a valve clearance setting device capable of accurately setting a valve clearance by controlling a tightening torque with a small value.

[0006]

According to the valve clearance setting device of the first aspect of the present invention, when the first motor is started, the rotational force generated by the first motor is increased by the booster. Is transmitted to the first drive shaft via a gear train. Accordingly, the first drive shaft and the outer socket rotate, and, for example, a bibot fitted to the outer socket is tightened. At this time, the plate-shaped member receives the reaction force generated by the power-increasing portion via the transmission member extending radially outward, and the plate-shaped member undergoes large bending deformation. Then, the magnitude of the reaction force is detected based on the change in the resistance value of the strain gauge attached to the plate-like member, and a rotation torque proportional to the reaction force is detected.

As described above, since the plate-shaped member receives the reaction force generated by the above-described booster through the transmission member, a large bending deformation occurs in the plate-shaped member, and even a minute reaction force is detected. Even a small rotation torque of 10 kgf · cm or less can be accurately detected. That is, it is possible to detect a small tightening torque of the above-mentioned pivot. Therefore, it is possible to accurately set the valve clearance by managing the tightening torque with a small value.

Further, since the inner socket has the second drive shaft attached to the tip so as to be able to move forward and backward, by fitting a lock nut into the inner socket, for example,
After the tightening of the bibot is completed, the locknut can be tightened to fix the bibot.

Further, since the strain gauge can be attached to a plate-like member, the strain gauge can be easily attached.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a valve clearance setting device according to the present invention will be described in detail with reference to the illustrated embodiments.

FIG. 1 is a sectional view of a valve clearance setting device according to an embodiment of the present invention. This valve clearance device is used, for example, for tightening the pivot 35 and the lock nut 36 shown in FIG.

As shown in FIG. 1, a cylindrical first drive shaft 2 is rotatably fitted to a main body 1 of the valve clearance setting device, and an outer socket is fitted to a distal end 2a of the first drive shaft 2. 15 are fitted to be able to move forward and backward. More specifically,
A spline groove 14 is formed at the end 2 a of the first drive shaft 2, and the outer socket 1 is inserted into the spline groove 14.
5 are fitted to be able to move forward and backward. This outer socket 1
5 is a fitting part 15a for the bibot to be fitted to the bibot 35.
At the tip. A coil spring 16 is provided between the outer socket 15 and the main body 1 so as to surround the distal end 2 a of the first drive shaft 2. A second drive shaft 11 is disposed inside the first drive shaft 2, and an inner socket 18 is fitted to a front end 11 a of the second drive shaft 11 so as to be able to advance and retreat. This inner socket 18 is used for the second drive shaft 1.
1 and has a lock nut fitting portion 18a at the distal end which rotates together with the lock nut 36 and fits into the lock nut 36. Further, between the inner socket 18 and the second drive shaft 11, a coil spring 17 is provided so as to surround the tip 11 a of the second drive shaft 11.
Is provided. Although not shown, the main body 1 includes:
A torque sensor for detecting the rotational force of the second drive shaft 11 is provided.

The first drive shaft 2 includes a rotary output shaft 3
Is received via the gear train 13. The gear train 13 is provided with a gear 19 fitted to the tip of the rotary output shaft 3, a transmission gear 20 disposed between the gear 19 and the first drive shaft 2 and meshing with the gear 19, and a first drive Axis 2
And an outer peripheral gear 21 meshed with the transmission gear 19.

The rotation output shaft 3 is connected to the first drive shaft 2.
Are accommodated in an accommodating case 4 fixed to the main body 1. A first air motor 5 as a first motor is attached to the storage case 4.
The rotation force generated by the first air motor 5 is increased by a planetary gear mechanism 6 as a booster mounted on the housing case 4. Further, the first air motor 5 has an output shaft 22 arranged in parallel with the first drive shaft 2. The output shaft 22 is fitted on the transmission shaft 23, and the transmission shaft 23
Is the sun gear 122 of the planetary gear mechanism 6 (shown in FIG. 2).
Connected to Further, a plate-shaped member 8 to which a strain gauge 9 is attached is fixed in the housing case 4.

FIG. 2 is a schematic sectional view of the casing of the planetary gear mechanism 6. As shown in FIG. 2, the planetary gear mechanism 6 is fitted on a transmission shaft 23 (shown in FIG. 1) and rotates with the transmission shaft 23. The sun gear 122 meshes with the sun gear 122 and Planetary gears 123 and 124 that revolve while rotating around the planetary gears, and the planetary gears 123 and 124
The internal gear 125 meshes with the internal gear 124.
This internal gear 125 is fixed to the inner peripheral surface of the casing 121 of the planetary gear mechanism 6. The transmission member 7 extending outward in the radial direction is fixed to the outer peripheral surface of the casing 121. The transmission member 7 includes a base 127 protruding in the radial direction, a rod 128 fixed to the base 127, and a ball 129 attached to the tip of the rod 128. This rod portion 128 extends in a direction perpendicular to the direction in which the base 127 protrudes,
The ball portion 129 at the tip of the rod portion 128 faces the smooth surface of the plate member 8.

The above-configured valve clearance setting device operates as follows when tightening the pivot 35 and the lock nut 36 shown in FIG.

First, the first air motor 5 and the second air motor 12 are both stopped. In that state,
The pivot 35 is fitted to the fitting portion 15a of the outer socket 15, and the lock nut 36 is fitted to the fitting portion 18a of the inner socket 18.

Next, when the first air motor 5 is started, the rotation output of the first air motor 5 is output from the output shaft 2.
2, transmitted to the planetary gear mechanism 6 via the transmission shaft 23.
Further, the output increased by the planetary gear mechanism 6 is sequentially transmitted to the rotation output shaft 3, the gear 19, the transmission gear 20, the outer peripheral gear 21, and the first drive shaft 2. Then, the first drive shaft 2 and the outer socket 15 rotate integrally, and the bibot 3 fitted into the fitting portion 15a of the outer socket 15
5 is tightened.

At this time, when the planetary gear mechanism 6 outputs, that is, the reaction force when the planetary gear mechanism 6 rotates the rotary output shaft 3, the internal gear 125 moves in the direction of arrow R as shown in FIG. The ball portion 129 of the transmission member 7 moves to the position indicated by the two-dot chain line and presses the plate-shaped member 8. As a result, large bending deformation occurs in the plate member 5, and the magnitude of the reaction force is detected based on a change in the resistance value of the strain gauge 6 attached to the plate member 5. Since the proportional rotation torque is detected, the tightening torque of the pivot 35 can be detected.

When the bibot 35 is seated, the first air motor 5 is rotated in the reverse direction to return the bibot 35 to a predetermined angle, and then the first air motor 5 is stopped. Thus, a target valve clearance C is set between the rocker arm 33 and the valve 32.

Next, the outer socket 15 is sandwiched by an air cylinder (not shown), and the second air motor 12 is started. Then, the second air motor 12 drives the second drive shaft 11, and the second drive shaft 11 and the inner socket 18 rotate integrally, and the lock nut 36 fitted to the fitting portion 18 a of the inner socket 18 is moved. Be tightened.
At this time, since the outer socket 15 is sandwiched between the air cylinders, the return of the outer socket 15 is prevented. That is, the return of the pivot 35 is prevented.

When the tightening torque of the lock nut 36 reaches a specified value, the second air motor 12 stops.

Finally, the inner socket 18 and the outer socket 15 are connected to a pivot 35 and a lock nut 36.
Remove from

As described above, since the plate member 8 receives the reaction force when the planetary gear mechanism 6 drives the rotary output shaft 3 via the transmission member 7, a large bending deformation occurs in the plate member 8. Thus, even a small reaction force is detected. Therefore, 1
Even a small rotation torque of 0 kgf · cm or less can be accurately detected. That is, it is possible to detect a small tightening torque of the above-mentioned pivot 35. As a result, the above-mentioned tightening torque can be managed with a very small value, and the valve clearance C can be set accurately.

The inner socket 18 has a tip 11a.
Since the second drive shaft 11 is provided so as to be able to advance and retreat, the lock nut 35 fitted to the inner socket 18 can be tightened to fix the bibot 35 after the tightening of the pivot 35 is completed.

The strain gauge 9 is provided on the plate-like member 8.
The strain gauge 9 can be easily attached.

In the above embodiment, the first air motor 5,
Although the second air motor 12 is used, for example, an AC (alternating current) motor, a servo motor, or the like may be used.

[0028]

As is clear from the above, the valve clearance setting device according to the first aspect of the present invention receives the reaction force when the booster outputs, by the plate-like member via the transmission member, so that the minute reaction force can be obtained. It can also be detected by force, for example, a small tightening torque of the bibot can be detected. Therefore, it is possible to accurately set the valve clearance by managing the tightening torque with a small value.

Further, since the inner socket has the second drive shaft attached to the tip so as to be able to move forward and backward, the lock nut is tightened after the tightening of the bibot is completed by fitting a lock nut into the inner socket, for example. To fix the bibot.

Since the strain gauge can be attached to the plate-like member, the strain gauge can be easily attached.

[Brief description of the drawings]

FIG. 1 is a sectional view of a valve clearance setting device according to an embodiment of the present invention.

FIG. 2 is a schematic sectional view of a planetary gear mechanism of the valve clearance setting device.

FIG. 3 is a sectional view of a main part of an engine in which the valve clearance setting device is used.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body 2 1st drive shaft 2a Tip of 1st drive shaft 5 1st air motor 6 Planetary gear mechanism 7 Transmission member 8 Plate member 9 Strain gauge 11 2nd drive shaft 11a Tip of 2nd drive shaft 12 2nd air motor 13 Gear Train 15 outer socket 18 inner socket 22 output shaft 121 planetary gear mechanism casing

Claims (1)

[Claims] A main body, a cylindrical first drive shaft rotatably provided on the main body, and an outer socket attached to a distal end so as to be able to advance and retreat, and disposed inside the first drive shaft; A first drive shaft having an inner socket movably attached to a distal end thereof, and a first drive shaft having an output shaft arranged in parallel with the first drive shaft;
A motor; a second motor driving the second drive shaft; a booster connected to an output shaft of the first motor; a gear train connecting the booster and the first drive shaft; A transmitting member fixed to the casing of the portion and extending radially outward; a plate-shaped member fixed to the main body while receiving a reaction force when the intensifying portion outputs through the transmitting member; A valve clearance setting device, comprising: a strain gauge attached to a member.