JPS6240768Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in the structure of a pneumatic tool that can be quickly stopped in an operating state.

Conventionally, the pneumatic tool 1 has been equipped with an air supply stop device 2 on an air hose 3 for supplying air to the pneumatic tool 1, as shown in FIG. 1 can be stopped and moved on to the next task, making it possible to work at considerably high speeds.

However, with the structure described above, even if the air supply is stopped by the stop device 2, the air motor section operates only for a short time due to the air remaining between the stop device 2 and the air motor section of the pneumatic tool 1. Due to continuous operation, there was a problem that the response of stopping was poor and there was a limit to high-speed work.

The present invention has been developed in view of the above problem, and includes providing a shutter valve valve body in a pneumatic tool near the air motor section, and supplying air to the air motor section by operating the shutter valve valve body by operating an electromagnetic solenoid. This pneumatic tool quickly stops the drive of the air motor section by stopping the air motor section and leaving almost no air between the air motor section and the above-mentioned shutter valve valve body, and has good stopping response and enables smooth high-speed work. is intended to provide.

In order to achieve the above object, the present invention is constructed as follows. In other words, inside the valve chamber that forms part of the air passage connecting the operating valve and the air motor section,
It consists of a piston part that slidably fits on the circumferential surface of the valve chamber and divides the valve chamber into a front chamber and a rear chamber, and a poppet part that opens and closes by coming into contact with and separating from a valve seat provided at the front end of the valve chamber. The piston portion is constantly pressed by the urging force of the first spring means compressed in the rear chamber, and the poppet portion is moved in the axial direction together with the piston portion, thereby separating the poppet portion from the valve seat. A shutter valve valve body is provided, a vent passage is provided in the piston portion to communicate the front and rear chambers of the valve chamber, and the valve is formed on an end face of the rear chamber by the biasing force of a second spring means compressed in the rear chamber. A ball valve body pressed against a seat is provided, and an electromagnetic solenoid is provided to separate the ball valve body from the valve seat on the end face of the rear chamber in the axial direction of the valve chamber and communicate the rear chamber with the relief hole,
When the amount of strain in the strain gauge reaches a predetermined amount, the electromagnetic solenoid is activated to release the air in the rear chamber to the relief hole and move the shutter valve valve body in the axial direction. The poppet portion is configured to contact the valve seat at the front end of the valve chamber to close the air passage. In the above configuration, the first spring means that presses the piston portion and the second spring means that presses the ball valve body have their respective functions, that is, press the piston portion and move the shutter valve valve body in the axial direction. It may be configured with two springs depending on the function of moving the poppet part away from the valve seat and the function of pressing the ball valve body against the valve seat, and the urging force of the spring means may be used. Consists of 1 spring,
One end of the spring may be brought into pressure contact with the piston portion of the shutter valve valve body, while the other end may be brought into pressure contact with the ball valve body.

According to the above configuration, when the strain amount of the strain gauge reaches a predetermined amount, the electromagnetic solenoid is operated to separate the ball valve body from the valve seat, and the air in the rear chamber is released to the relief hole. At the same time, the shutter valve valve body is moved in the axial direction to bring the poppet into contact with the valve seat at the front end of the valve chamber, thereby closing the air passage.

The present invention will be specifically explained below based on the embodiment shown in FIG.

In Fig. 2, 6 is a handle, 7 is a casing 8
The air motor section is arranged in the center of the interior, 9 is the striking section arranged at the front part of the casing 8, 10 is the drive shaft, 1
Reference numeral 1 denotes an air supply stop valve having a shutter valve valve body 12 and a ball valve body 13, which is disposed below the air motor section 7 in the casing with its axis directed in the front-rear direction. Air is supplied to the air supply stop valve 11 by operating the trigger 31.
The air is supplied into the motor section 7 via the air motor section 7, and is supplied to the drive shaft 1 through the striking section 9 by the drive of the air motor section 7.
0 is rotated shockingly.

The air motor section 7 includes a rotor 33 and vanes 3.
4, the air is passed through the operation valve 32, the first intake passage 36, and the air supply stop valve 11 from the air supply port 35, and then the air is passed through the second intake passage 1.
4 and into the rotor 3.
3 is rotated, the air is exhausted from an exhaust port 16 via an exhaust passage 15.

The striking portion 9 has a well-known structure consisting of a hammer cam 17, a hammer case 18, a hammer 19 and a hammer pin 20, and is adapted to impact-rotate the drive shaft 10, the rear end of which is inserted into the striking portion 9, and a fastening holder (not shown) such as a bolt is connected to the protruding front end of the drive shaft 10.

Furthermore, the air supply stop valve 11 has a cylindrical valve chamber 21 that forms a part of an air passage connecting the operating valve 32 and the air motor section 7, and also has a front end of the cylindrical valve chamber 21 as an air reservoir. On the other hand, an electromagnetic solenoid 23 is disposed coaxially at the rear end of the valve chamber 21. The air supply stop valve 11 has a piston portion 2 that is slidably fitted into the inner peripheral surface of the valve chamber 21 and partitions the valve chamber 21 into a front chamber 21a and a rear chamber 21b.
4 and a poppet portion 27 that is supported via a rod 25 at the front of the piston portion 24 and opens and closes by approaching and separating from a valve seat 26 provided at the front end of the valve chamber 21. At the same time, the piston portion 24 is provided with the front and rear chambers 21 of the valve chamber 21.
A and 21b are provided with a vent passage 24a that communicates with each other, and a steel ball 30 is pressed against a valve seat 29 on the end face of the rear chamber 21b by a spring 28 as a second spring means compressed in the rear chamber 21b. A ball valve body 13 is provided.

In the shutter valve body 12, the piston portion 24 is constantly pressed forward by the urging force of the spring 28, which also serves as the first spring means, so the poppet portion 27 is separated from the valve seat 26 and The chamber 21a and the air reservoir 22 are communicated with each other, so that air flows from the air reservoir 22 to the opening 14 of the second intake passage 14 provided in the front chamber 21a and the valve chamber wall.
The air is supplied into the second intake passage 14 through the passage a. As described above, when air is supplied into the front chamber 21a, air is also supplied into the rear chamber 21b through the vent passage 24a of the piston portion 24. However, when the electromagnetic solenoid 23 is actuated at a predetermined time, the electromagnetic solenoid The actuating rod 23a of the valve chamber 23 moves forward to separate the steel ball 30 from the valve seat 29, and releases the air in the rear chamber 21b to the outside from the escape hole 37 formed at the rear end of the valve chamber.
Air in the vent passage 24a of the piston part 24
It is supplied into the rear chamber 21b through. For this reason,
The pressure in the rear chamber 21b is lower than that in the front chamber 21a, and the air presses the front surface of the piston portion 24, causing the piston portion 24 to retreat inside the valve chamber 21 against the biasing force of the spring 28, and the poppet portion 27 is valve seat 2
6 to shut off the front chamber 21a and the air reservoir 22, thereby preventing air from being supplied to the air motor section 7.

Note that the spring 28 may be composed not only of one member but also of two members.

On the other hand, a one-way clutch 39 is fitted to the rear end of the rotor 33 of the air motor section 7 via a sleeve 38, and the front end is fitted onto the outer peripheral surface of the one-way clutch 39, and the rear end is connected to the casing 8.
A flexible cylindrical body 40 fixed to is provided, and a strain gauge 41 is provided on the outer surface of the cylindrical body 40. The one-way clutch 39 is rotatable in the rotational direction of the rotor 33, but not rotatable in the counter-rotation direction of the rotor 33, and connects the drive shaft 1.
When the rotor 33 is rotated in the counter-rotation direction due to a reaction force generated by the tightening resistance of bolts, etc. rotated by The clutch 39 is twisted and deflected in the counter-rotational direction, and this deflection is detected by the strain gauge 41 and the electromagnetic solenoid 2
I am trying to activate 3.

Now, the pneumatic tool having the above configuration operates as follows.

By operating the operation valve 32 via the trigger 31, air is supplied to the first intake passage 36 and the air reservoir 22.
The air is supplied into the motor section 7 from the second intake passage 14 through the front chamber 21a of the valve chamber 21 to drive the air motor section 7, and through the striking section 9 to the drive shaft 1.
0 is rotated with an impact to start tightening work of bolts, etc.

During the bolt tightening operation, if the bolt is not tightened properly in the bolt tightening hole, or when the bolt tightening operation approaches the end, a large reaction force is applied to the drive shaft 10. When a reaction force is applied to the rotor 33 through the drive shaft 10 in this way, the cylinder 40 is twisted in the counter-rotation direction, causing a deflection of the cylinder 40, and the deflection of the cylinder 40 is detected by the strain gauge 41. do. When the amount of strain in the strain gauge 41 reaches a predetermined amount, the electromagnetic solenoid 23 is actuated to move the actuating rod 23 forward to separate the steel ball 30 from the valve seat 29, causing the valve chamber 21 to open in the rear chamber 21b. The air is released from the escape hole 37 to the rear chamber 2.
The pressure inside 1b is reduced, and the front chamber 21a and the rear chamber 21
The piston part 24 in the valve chamber 21 is moved back by utilizing the pressure difference between the poppet part 27 and the valve seat 26, thereby blocking the air reservoir 22 and the front chamber 21a. Therefore, air is no longer supplied into the air motor section 7, and moreover, air is not supplied to the front chamber 21a and the second chamber.
Since it remains only in the intake passage 14, the drive of the air motor section 7 is immediately stopped with good response.

After the motor stops, release the trigger 31 and open the poppet part 2.
When the pressure acting on the front end surface of the shutter valve body 12 decreases, the biasing force of the spring 28 causes the shutter valve body 12 to
The entire valve moves in the axial direction, and the poppet portion 27 separates from the valve seat 26, preparing for the next operation.

As detailed in the above embodiment, the present invention provides a shutter valve valve body near the air motor section in a pneumatic tool, and operates the shutter valve valve body by operating an electromagnetic solenoid to supply air to the air motor section. At the same time, almost no air is left between the air motor section and the shutter valve body, which improves the responsiveness of the stop and enables smooth high-speed work, improving work efficiency and simplifying the structure. And it can be made compact.

[Brief explanation of the drawing]

FIG. 1 is an explanatory view showing a conventional pneumatic tool, and FIG. 2 is a longitudinal sectional view showing a pneumatic tool according to an embodiment of the present invention. 7...Air motor section, 10...Drive shaft, 11...Air supply stop valve, 12...Shutter valve valve body, 13...
Ball valve body, 21... Valve chamber, 23... Electromagnetic solenoid, 24... Piston portion, 24a... Vent passage, 2
6...Valve seat, 27...Poppet part, 28...Spring, 29...Valve seat, 30...Steel ball, 32...
Operation valve.

Claims (1)

[Claims for Utility Model Registration] (1) Strain gauge 4 that detects the reaction force from the drive shaft 10
1, the pneumatic tool rotates the drive shaft 10 by driving the air motor section 7 by operating the operation valve 32, the valve chamber forming a part of the air passage connecting the operation valve 32 and the air motor section 7; 21, a piston portion 2 is slidably fitted onto the circumferential surface of the valve chamber to partition the valve chamber 21 into a front chamber 21a and a rear chamber 21b.
4 and a valve seat 26 provided at the front end of the valve chamber 21.
The piston part 24 is constantly pressed by the urging force of the first spring means 28, which is comprised of a poppet part 27 that opens and closes when approaching and separating, and is compressed in the rear chamber 21b. A shutter valve body 12 is provided which is moved in the axial direction to separate the poppet portion 24 from the valve seat 26, and the piston portion 2
4 is provided with a vent passage 24a that communicates the front and rear chambers 21a and 21b of the valve chamber 21, and the rear chamber 2
A ball valve body 13 is provided which is pressed against a valve seat 29 formed on the end face of the rear chamber 21b by the biasing force of the second spring means 28 compressed in the rear chamber 21b. From the seat 29 to the valve chamber 21
The rear chamber 21b and the relief hole 3 are spaced apart in the axial direction.
7 is provided, and when the strain amount of the strain gauge reaches a predetermined amount, the electromagnetic solenoid 23 is actuated to release the air in the rear chamber 21b to the relief hole 37. A pneumatic tool characterized in that the shutter valve valve body 12 is moved in the axial direction, the poppet portion 27 of the shutter valve valve body 12 is brought into contact with the valve seat 26 at the front end of the valve chamber, and the air passage is closed. . (2) The pneumatic tool according to claim 1, wherein the first spring means and the second spring means are constituted by one spring.