JPH08336776A - Cushioning mechanism in pneumatic nailing machine - Google Patents

Abstract

PURPOSE: To effectively absorb the impact of an impact piston driven by high pressure air, without making a bumper large. CONSTITUTION: Compressed air is supplied and exhausted from the upper end of an impact cylinder 3 disposed inside a body so as to drive an impact piston 7 in the impact cylinder 3 for nail driving, and a driver 8 integrally connected to the impact piston 7 is passed through a driver guide hole 21, formed at the lower part of the impact cylinder 3, so as to drive out to a shot port. In a pneumatic nailing machine of such constitution, a bumper 20 for receiving the lower face of the impact piston 7 is disposed below the impact cylinder 3. A flexure margin is formed inside the bumper 20, and a clearance between the driver 8 and the driver guide hole 21 is formed small.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pneumatic nailing machine in which compressed air is supplied to and discharged from a striking cylinder to drive a striking piston together with a driver to stop the driven striking piston at bottom dead center. The present invention relates to a shock absorbing mechanism that absorbs a shock of a striking piston by forming a bumper for causing the shock absorber to have a special structure.

[0002]

2. Description of the Related Art Generally, this type of pneumatic nailing machine uses compressed air to drive a striking piston to drive out a nail, but recently high-pressure compressed air has become available. Therefore, it is possible to realize a nailing machine with a high output despite its small size and good operability.

By the way, when the striking piston is driven by high-pressure air, the impact force also increases, so that the buffer bumper for absorbing the impact of the striking piston must be enlarged. However, if the bumper becomes large, it becomes difficult to realize miniaturization.

However, since the bumper of the conventional nail driving machine has a bending margin formed outside, the bumper is bent and deformed outside when the impact piston receives a shock. Therefore, in order to buffer a larger impact force, it is necessary to form a large bending allowance in consideration of the bending amount of the bumper to increase the bending amount of the bumper. There is a problem that the durability of the bumper is reduced due to the large bending of the bumper.

[0005]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned drawbacks and provides a cushioning mechanism in a pneumatic nailing machine which can efficiently absorb the impact of a striking piston driven by high pressure air without increasing the size of a bumper. The purpose is to do.

[0006]

In order to achieve the above object, the cushioning mechanism in the pneumatic nailing machine according to the present invention comprises:
By supplying and exhausting compressed air from the upper end of the striking cylinder arranged inside the body, the striking piston in the striking cylinder is driven by nail driving, and the driver guide integrally formed with the striking piston is formed in the lower part of the striking cylinder. In a pneumatic nailing machine that penetrates through a hole and strikes at an injection port, a bumper that receives the lower surface of a striking piston is arranged below the striking cylinder, and the upper portion of this bumper is formed so as to bend inward, and the driver and driver It is characterized in that the clearance between the guide hole and the guide hole is small.

[0007]

According to the present invention, after the striking piston is driven by driving the nail, the lower surface of the striking piston impacts the bumper, so that the upper portion of the bumper is bent and deformed inward. At this time, the inner space of the bumper is compressed and contracted, and the opening at the upper end is pressed against the lower surface of the striking piston to be closed. Further, the clearance between the driver and the driver guide hole is formed small, and the air in the inner space cannot instantaneously escape to the outside from the clearance, so the air trapped inside is compressed inside the bumper. To be done. The compressed air is discharged from the clearance immediately after the striking piston stops.

As described above, the impact of the striking piston is efficiently absorbed by the synergistic effect of the elasticity of the bumper and the air cushion generated inside thereof. Therefore, the impact of the striking piston can be sufficiently absorbed without increasing the size of the bumper itself.

Further, since the air in the inner space cannot escape to the outside at a very short moment until the striking piston hits the bumper and stops, the bending deformation of the bumper is alleviated by the air sealed in the inner space. Since excessive deformation is prevented, the durability of the bumper is also improved.

[0010]

1 and 2 show a nailing machine according to the present invention. This nailing machine, like a normal pneumatic nailing machine, has a compressed air supply source ( An air chamber 2 for storing compressed air taken in from (not shown) and a striking cylinder 3 are provided, and compressed air is supplied to and discharged from the striking cylinder 3 by actuation of a start valve 5 and a head valve 6 which are interlocked by operating a trigger lever 4. Then, the striking piston 7 in the striking cylinder 3 is reciprocated, the driver 8 integrally coupled to the striking piston 7 is driven into the nose portion 9 at the tip of the body 1, and the nail 10 supplied into the injection port of the nose portion 9 is removed. It is driven by being driven by being hit.

That is, as shown in FIG. 3, the valve stem 11 of the starting valve 5 is pushed by the trigger lever 4 and the pilot valve 12 is moved downward so that the air passage 13 is opened to the exhaust port 14 to open the upper chamber of the head valve 6. The compressed air of 15 is discharged from the exhaust port 14 to open and operate the head valve 6, and the compressed air of the air chamber 2 is rapidly supplied into the striking cylinder 3 to drive the striking piston 7.

By returning the trigger lever 4 after the nail is driven, the valve stem 11 of the starting valve 5 is moved downward by the spring, and the pilot valve 12 is moved upward simultaneously, as shown in FIG. 13 to upper chamber 15
Compressed air is supplied to the head valve 6 to close it, and the exhaust hole 16 is opened to supply compressed air into the striking cylinder 3 through the exhaust chamber 17 formed along the side surface of the body 1. Exhausted to the outside. At the same time, the impact piston 7 is moved upward by the compressed air stored in the blowback chamber 18 around the impact cylinder 3 compressed at the time of impact, returning to the initial top dead center position, and the next nail driving is prepared. Of.

A bumper 20 for receiving the lower surface of the driven striking piston 7 is arranged below the striking cylinder 3. The bumper 20 is formed of an elastic material such as rubber into a cylindrical shape, and the diameter of the lower portion is made larger than that of the upper portion so that the bumper 20 bends inward when an impact is applied from above.

The driver 8 is fitted in a driver guide hole 21 provided below the bumper 20 and slidably accommodated in the injection port of the nose portion 9. The clearance between the driver 8 and the driver guide hole 21 is formed small so that the air in the inner space S of the bumper 20 does not easily escape from the clearance.

In the shock absorbing mechanism of the striking piston 7,
After the striking piston 7 is driven by driving the nails, the lower surface of the striking piston impacts the bumper 20, and the upper portion of the bumper 20 is bent and deformed inward as shown in FIG. At this time, bumper 2
The inner space S of 0 is compressed and reduced, and the opening at the upper end is pressed against the lower surface of the striking piston 7 to be closed. Further, the clearance between the driver 8 and the driver guide hole 21 is formed to be small, and the air in the inner space S cannot instantaneously escape to the outside from the clearance. Therefore, the air trapped inside is bumper 20. Is compressed inside. The compressed air is discharged from the clearance immediately after the striking piston 7 stops.

As described above, the impact of the striking piston 7 is efficiently absorbed by the synergistic effect of the elasticity of the bumper 20 and the air cushion generated inside thereof. Therefore, the impact of the impact piston 7 can be sufficiently absorbed without increasing the size of the bumper 20 itself.

Further, since the air in the inner space S cannot escape to the outside at a very short moment until the striking piston 7 hits the bumper 20 and stops, the bending deformation of the bumper 20 is also sealed in the inner space S. Since the air is relieved and excessive deformation is prevented, the durability of the bumper 20 is also improved.

[Brief description of drawings]

FIG. 1 is a side view of a nailing machine according to the present invention.

FIG. 2 is a vertical sectional view of the above-mentioned nail driver.

FIG. 3 is a cross-sectional view of the above-described nail driving machine when the nail driving operation is performed.

[Explanation of symbols]

 1 Body 3 Impact Cylinder 7 Impact Piston 8 Driver 20 Bumper 21 Driver Guide Hole

Claims (1)

[Claims] 1. A striking piston inside the striking cylinder is driven by a nail by driving and discharging compressed air from the upper end of the striking cylinder arranged inside the body, and a driver integrally connected to the striking piston is attached to the lower part of the striking cylinder. In the pneumatic nailing machine that penetrates through the driver guide hole formed in the above and hammers into the injection port, a bumper that receives the lower surface of the striking piston is arranged below the striking cylinder, and the upper portion of this bumper is formed to bend inward. At the same time, the clearance between the driver and the driver guide hole is formed to be small, and a buffer mechanism in a pneumatic nailer.