JP4223776B2 - Air driver device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an air driver device, and in particular, by forming a detection-side flow path and a motor-side flow path communicating with a pressure detection means and adopting a mechanism that closes the motor-side flow path just before shut-off, The present invention relates to an air driver device that can apply air pressure to a pressure detecting means when it is off and count the number of tightening of a bolt or the like.
[0002]
[Prior art]
The air driver device is used for a screw tightening air tool such as a nut runner. For example, as shown in Japanese Patent Publication No. 58-34265, the torque of the main shaft is adjusted to an adjustable torque. When it reaches, it has a structure that shuts off the supply of air from the compressor and stops the motor.
This air driver device includes a push rod that rotates a motor by opening a valve disposed in an air supply path by pushing a main shaft, and when a predetermined torque is exceeded between a cam rotated by the motor and the main shaft. It is connected by a torque control mechanism that is relatively rotationally differential, and has a configuration in which the push rod is retracted by the rotational differential of the torque control mechanism to close the valve and stop the motor.
[0003]
[Problems to be solved by the invention]
By the way, in the conventional air driver device, when the rotation of the main shaft exceeds a predetermined torque, the push rod is retracted by the rotational differential of the torque control mechanism to directly close the valve. There has been a problem that it is not possible to employ a mechanism that accurately counts such quantities.
[0004]
In view of the problems of the conventional air driver device, the present invention has a mechanism for forming a detection-side flow path and a motor-side flow path communicating with the pressure detection means and closing the motor-side flow path just before shut-off. By adopting it, an object of the present invention is to provide an air driver device that allows high-pressure air to act on the pressure detection means and accurately count the number of tightening of bolts and the like.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the air driver device of the present invention includes a push rod that rotates a motor by opening a valve disposed in an air supply path by pushing the main shaft, and includes a cam and a main shaft that are rotated by the motor. In the air driver device that is connected by a torque control mechanism that relatively differentially rotates when a predetermined torque is exceeded, the push rod is retracted by the rotational differential of the torque control mechanism, and the motor is stopped. On the downstream side of the valve disposed in the air supply path, a motor-side flow path communicating with the motor and a detection-side flow path communicating with the pressure detection means are formed, and a push rod by a rotational differential of the torque control mechanism A plug that closes only the motor-side flow path when retracting is disposed on the tip of the push rod, and the push rod is slidable on the push rod. Fitted around the Yupaipu, characterized in that in order to maintain the open state of the valve upon depression of the main shaft via the push pipe.
[0006]
This air driver device forms a motor side flow path communicating with the motor and a detection side flow path communicating with the pressure detection means on the downstream side of the valve disposed in the air supply path, and rotates the torque control mechanism. A plug that closes only the motor-side flow path when the push rod is retracted by differential is arranged on the distal end side of the push rod, and a push pipe is slidably fitted to the push rod, through the push pipe Since the valve is kept open when the main shaft is pushed in, high-pressure air is applied to the detection-side flow path when the push rod is retracted by the rotational differential of the torque control mechanism to stop the motor. Thus, it is possible to recognize the shut-off and accurately count the number of tightening of the bolt or the like.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of an air driver device of the present invention will be described below with reference to the drawings.
[0008]
1 to 5 show an embodiment of an air driver device of the present invention.
The air driver device includes a push rod 4 that rotates the motor 3 by opening the valve 2 disposed in the air supply path 8 by pushing the main shaft 1, and the cam 5 and the main shaft 1 that are rotated by the motor 3. It is connected by a torque control mechanism 6 that makes a relative rotational differential when a predetermined torque is exceeded, and the push rod 4 is moved backward by the rotational differential of the torque control mechanism 6 to close the valve 2.
In the air driver device, a motor side channel 9 a communicating with the motor 3 and a detection side channel 9 b communicating with the pressure detecting means 7 are formed on the downstream side of the valve 2 disposed in the air supply path 8. In addition, a plug body 10 that closes only the motor-side flow path 9a when the push rod 4 is retracted by the rotational differential of the torque control mechanism 6 is disposed on the distal end side of the push rod 4, and can slide on the push rod 4. A push pipe 11 is externally fitted to the valve 2 so that the valve 2 is kept open when the main shaft 1 is pushed through the push pipe 11.
[0009]
Specifically, as shown in FIGS. 2 to 4, the push rod 4 is slidably inserted into the shaft hole 13 of the slide bar 12 that slidably penetrates the plug body 10.
A push piece 14 that presses the plug 10 from the inside is fitted on the slide bar 12, and the push piece 14 fits a pin 16 into a long groove 15 formed on the side of the shaft hole 13. Thus, it can move within the range of the long groove 15.
The pin 16 is disposed between the push rod 4 and the bottom of the shaft hole 13, whereby the push rod 4 is configured to open the plug body 10 via the push piece 14.
On the other hand, the push pipe 11 is disposed so as to be in contact with the opening edge of the shaft hole 13 of the slide bar 12, and the valve 2 is opened by moving the slide bar 12 by pressing the opening edge. Has been.
At this time, since the push piece 14 is retracted in the range of the long groove 15, the push pipe 11 can open the valve 2 with the plug body 10 closed without causing the push piece 14 to act on the plug body 10. Has been.
[0010]
By the way, as shown in FIG. 1, the speed reduction part 17 is arrange | positioned at the front end side of the motor 3, and the drive shaft 18 of the speed reduction part 17 is rotatably supported with respect to the main body via the bearing. . A square tubular fitting hole 36 is formed at the tip of the drive shaft 18.
[0011]
A cylindrical case 19 is screwed to the tip of the main body, and the case 19 includes the main shaft 1, the cam 5, the pilot pin 22, the cam ring 23, the spring 24, the adjusting screw 25, the ball 26, and the like. A torque control mechanism 6 is attached.
The main shaft 1 is provided with an engagement hole 27 for attaching various attachments at the tip, and is supported in a state of being inserted into the case 19. An inner recess 28 into which the pilot pin 22 and the cam 5 are inserted is drilled in the base end portion of the main shaft 1, and a screw 29 is engraved on the outer periphery of the central portion of the main shaft 1.
[0012]
A pilot pin 22 is inserted into the inner recess 28 of the main shaft 1 via a spring 30 for pressing the pilot pin. As shown in FIG. 5, the pilot pin 22 has a chamfered step portion 31 formed on the outer peripheral surface of the tip, and a locking pin 32 is fixed through the center portion thereof.
Further, a spring 30 is in contact with the front end side of the pilot pin 22, and the other end side is inserted into a pilot pin fitting hole 33 formed inside the front end of the cam 5.
[0013]
As shown in FIG. 2, the pilot pin 22 before driving of the air driver device is a lock pin 40 that is slidable on the spindle 1 and urged by a ring spring 34 with respect to the chamfered step portion 31. Is locked.
In this case, the locking pin 32 protruding from the pilot pin 22 is inserted into a groove 35 in the longitudinal direction of the axial center of the cam 5 provided at the tip of the cam 5.
[0014]
The cam 5 is fitted into the fitting hole 36 of the drive shaft 18 so that the base portion can slide in the axial direction and is fixed in the rotational direction. A push rod 4 is fitted into the base portion of the cam 5, the tip end portion of the push rod 4 abuts on the rear end surface of the pilot pin 22, and the base end portion faces or abuts the valve 2.
Further, as shown in FIGS. 5C to 5E, a ball support surface 20 is formed on the outer peripheral surface of the cam 5 by chamfering a square cross section. Are fitted and supported by balls 26 made of steel balls.
As shown in FIG. 5 (c), the ball 26 fitted and supported in the ball fitting hole 21 drilled in the main shaft 1 is brought into contact with each ball support surface 20 of the cam 5. It is.
[0015]
On the other hand, as shown in FIGS. 1 to 4, a cam ring 23 having a taper surface on the outer surface of the ball fitting support portion of the main shaft 1 is slidably fitted in the axial direction. Yes.
In addition, the adjusting screw 25 is screwed into a screw engraved on the outer periphery of the main shaft 1 at a position facing the cam ring 23 in the axial direction, and teeth 38 are formed in a gear shape on the side surface of the adjusting screw 25 facing the detent 37. Engrave.
As a result, when the tip of a Phillips screwdriver is fitted in the recess 39 of the detent 37 fitted on the outer periphery of the main shaft 1 so as to come into contact with the adjusting screw 25 and the screwdriver is turned to tighten the screw, the screwdriver The cross section and the teeth 38 of the adjusting screw mesh with each other like a gear so that the adjusting screw 25 rotates forward and backward, and the detent 37 can be brought into contact with and separated from the opposing cam ring 23.
Thus, by bringing the detent 37 into and out of contact with the cam ring 23, the compression strength of the torque adjusting spring 24 interposed between the cam ring 23 and the detent 37 is adjusted.
[0016]
Due to the elastic force of the spring 24, the tapered surface of the cam ring 23 is pressed by the ball 26, and the pressed ball 26 is held by the ball fitting support portion of the main shaft 1. Thereby, the main shaft 1 can receive the rotational force from the cam 5 driven by the motor 3 via the ball and can rotate.
When the rotational force of the motor 3 reaches a preset torque value or more, the ball 26 is pushed out from the ball support surface 20 of the cam 5 in the outer circumferential direction, and torque transmission between the cam 5 and the main shaft 1 is stopped. .
[0017]
Next, a method of using the air driver device of this embodiment will be described.
First, when bolts, nuts or screws are tightened, when an attachment is attached to the tip of the main shaft 1 and the main shaft 1 is pressed in the axial direction from the state of FIG. 2A, as shown in FIG. The valve 2 is operated to open via the pilot pin 22 and the push rod 4, and high-pressure air from the compressor is supplied to the air motor 3 in the main body. As a result, the motor 3 rotates in a predetermined direction, and the drive shaft 18 rotates through the speed reduction unit 17.
[0018]
Since the cam 5 is fitted to the drive shaft 18 in a polygonal shape or a spline structure, the cam 5 also rotates together with the drive shaft 18.
The ball 26 fitted and supported on the main shaft 1 by the pressing force of the spring 24 is pressed against the ball support surface of the cam 5, whereby the rotational force of the motor 3 is transmitted from the cam 5 via the ball 26 to the main shaft 1. Is transmitted to.
Then, the main shaft 1 is retracted by a pressing force during the tightening, and desired tightening is performed.
[0019]
At this time, the lock pin 40 supported by the main shaft 1 is in contact with the chamfered step portion 31 of the pilot pin 22 because the pilot pin 22 is pressed toward the cam 5 by the action of the spring 30.
Note that the locking pin 32 of the pilot pin 22 is slidably fitted in the groove 35 of the cam 5, whereby the pilot pin 22 rotates integrally with the cam 5.
[0020]
On the other hand, when tightening is performed and the tightening torque reaches a value determined in advance by adjusting the elasticity of the spring 24, when the cam 5 rotates, the rotational torque of the cam 5 causes the cam ring 23 to move. Therefore, it becomes larger than the spring suppression pressure pressed against the ball support surface 20 of the cam 5.
When the rotational torque of the cam 5 becomes larger than the pressing force of the spring 30, the ball 26 pressed against the ball support surface 20 by the rotational force of the cam 5 is pushed up.
That is, the ball floats (moves toward the outer periphery of the main shaft 1) along the tapered surface of the cam ring 23 and compresses the spring 24.
[0021]
As described above, when the ball 26 is pushed up from the ball support surface of the cam 5 in the outer circumferential direction (see FIG. 5D), a differential in the rotational direction is generated between the cam 5 and the main shaft 1, and the two rotate. There is a difference.
As a result, the pilot pin 22 provided so as to rotate integrally with the cam 5 rotates relative to the main shaft 1, and the lock pin is located on the protruding side of the chamfered step portion 31. 40 is pushed up (see FIG. 5B).
[0022]
As a result, the locking of the pilot pin 22 with the chamfered step 31 by the lock pin 40 is released, and the pilot pin 22 can move to the tip side as shown in FIG. It becomes like this.
As a result, a part of the high-pressure air pressure supplied to the main body and the suppression of the valve 2 receiving the action of the spring 41 press the pilot pin 22 against the spring 30 via the push rod 4, and the pilot pin 22 is moved to the tip side.
[0023]
In this case, when the push rod 4 is retracted to close the plug body 10 and stop the motor 3, the air driver device of this embodiment continues to push the main shaft 1 as shown in FIG. As a result, the push pipe 11 holds the valve 2 in an open state via the slide rod 12, so that high-pressure air is supplied to the detection-side flow path 9 b immediately before the valve 2 is closed, and the pressure detection means 7 is supplied. Thus, it is possible to recognize the shut-off and to count the number of tightening of the bolt or the like.
[0024]
After the completion of tightening, as shown in FIG. 3B, by stopping the pushing, the main shaft 1, the push pipe 11 and the slide bar 12 are retracted (returned to the tip side), and the valve 2 is closed. The pilot pin 22 is pushed back by the action of the spring 30 to return to its original state, and the lock pin 40 is locked to the chamfered step portion 31 of the pilot pin 22 so that the next tightening can be performed.
[0025]
As mentioned above, although the Example of this invention was described, the structure of the air driver apparatus of this invention is not limited to description of this Example, It can change suitably in the range which does not deviate from the meaning. is there.
[0026]
【The invention's effect】
According to the air driver device of the present invention, the motor side flow path communicating with the motor and the detection side flow path communicating with the pressure detection means are formed on the downstream side of the valve disposed in the air supply path, and the torque A plug that closes only the motor-side flow path when the push rod is retracted by the rotational differential of the control mechanism is disposed on the distal end side of the push rod, and a push pipe is slidably fitted to the push rod, Since the valve is kept open when the main shaft is pushed through the pipe, when the push rod is retracted by the rotational differential of the torque control mechanism and the motor is stopped, high-pressure air is applied to the detection-side flow path. This makes it possible to recognize the shutoff and accurately count the number of tightening of bolts, etc., and manage the tightening work of bolts etc. It can be carried out in.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of an air driver device of the present invention.
FIGS. 2A and 2B show an air driver device according to the embodiment, in which FIG. 2A is a cross-sectional view before start, and FIG. 2B is a cross-sectional view at start;
FIGS. 3A and 3B show the air driver device of the embodiment, in which FIG. 3A is a cross-sectional view at the time of shut-off, and FIG. 3B is a cross-sectional view after the shut-off.
4A and 4B show a stopper and a slide bar, where FIG. 4A is a sectional front view, FIG. 4B is an exploded view thereof, FIG. 4C is a sectional plan view, and FIG.
5A and 5B show the main shaft 1, in which FIG. 5A is a cross-sectional view showing an engaged state of a pilot pin and a lock pin, FIG. 5B is a cross-sectional view showing a disengaged state, and FIG. Sectional drawing which shows an engagement state, (d) is sectional drawing which shows the state by which engagement was cancelled | released, (e) is a disassembled perspective view of a cam and a pilot pin.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Main shaft 2 Valve 3 Motor 4 Push rod 5 Cam 6 Torque control mechanism 7 Pressure detection means 8 Air supply path 9a Motor side flow path 9b Detection side flow path 10 Plug body 11 Push pipe 12 Slide rod 13 Shaft hole 14 Push piece 15 Long groove 16 Pin 17 Deceleration part 18 Drive shaft 19 Case 20 Ball support surface 21 Ball fitting hole 22 Pilot pin 23 Cam ring 24 Spring 25 Adjustment screw 26 Ball 27 Engagement hole 28 Inner recess 29 Screw 30 Spring 31 Chamfering step 32 Locking Pin 33 Pilot pin fitting hole 34 Ring spring 35 Groove 36 Fitting hole 37 Detent 38 Teeth 39 Recess 40 Lock pin 41 Spring

Claims (1)

A push rod that opens the valve in the air supply path by pushing the main shaft and rotates the motor is provided, and the cam that rotates by the motor and the main shaft are rotated relative to each other when a predetermined torque is exceeded. In the air driver device, which is connected by a torque control mechanism to be operated and the push rod is retracted by the rotational differential of the torque control mechanism to stop the motor, the motor is disposed downstream of the valve disposed in the air supply path. A plug for closing only the motor-side flow path when the push rod is retracted by the rotational differential of the torque control mechanism is formed, and a motor-side flow path communicating with the pressure detection means is formed. The push pipe is slidably fitted on the push rod and is arranged on the tip end side of the rod, and the spindle is pushed through the push pipe. Air driver device being characterized in that in order to maintain the open state of the valve during write.

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