JPS5841108Y2 - Pneumatic driven nailer trigger device - Google Patents

Description

[Detailed description of the invention] This invention uses pressurized air as a power source to drive a striking piston/cylinder mechanism, and is loaded into a magazine by a rond-shaped driver integrally connected to this striking piston.
The present invention relates to a pneumatically driven nailer that drives out nails of various shapes one by one fed into a nose, and particularly to a trigger device for fully operating a trigger valve built into the nailer.

In general, pneumatically driven nailers operate a trigger valve using a contact lever operated by a trigger lever and a contact arm, and open a gap between the striking cylinder and a main air chamber that constantly stores pressurized air using a head valve. The hammer piston is momentarily moved to the bottom dead center and the nail is driven into the material by the driver.

However, if either the trigger lever or the contact arm is incompletely operated without reaching top dead center, the contact lever will remain in a state of incomplete operation, and the trigger valve will not be completely switched. Therefore, the pressurized air in the head valve is not completely released into the atmosphere via the trigger valve, and the opening time of the head valve becomes shorter than normal.

As a result, the driving force of the striking piston is reduced, and even when the striking piston reaches the bottom dead center, sufficient pressurized air is not stored in the blowback air chamber, preventing the striking piston from returning to the top dead center. There was a drawback that it was not completed completely.

The present invention eliminates the drawbacks of the prior art, and allows the trigger valve to remain completely closed for a certain period of time even if either the contact arm or the trigger lever is not completely moved to the top dead center or both are half-operated. An object of the present invention is to provide a trigger device for a pneumatically driven nail gun that is operable.

In order to achieve this purpose, the present invention consists of a striking cylinder disposed inside the nailer body, and a rod-shaped driver that is slidably and tightly fitted into this cylinder and drives out nails. a striking piston; a main air chamber formed on the outer periphery of the cylinder; a head valve that opens and closes between the main air chamber and the upper chamber of the striking piston of the cylinder; A pneumatically driven nailing machine comprising a trigger valve that selectively communicates between an air chamber or between the upper chamber of the valve piston and the atmosphere via a controlled air passage, the trigger valve of the trigger valve; a trigger lever, one end of which is pivotally supported on the nailer body facing the stem, and a trigger lever disposed between the trigger lever and the trigger valve stem, and one end of which is connected to the other end of the trigger lever. a contact lever that is pivotably supported; a contact arm that is reciprocably disposed along a nose that projects from the nailer body and whose tip protrudes resiliently from the tip of the nose; The contact arm has a rod portion disposed between the base end of the contact arm and the other end of the contact lever, and a compression spring provided between the rod portion and the base end of the contact arm. The spring force of the spring is smaller than the total pressure applied to the trigger valve stem when the air pressure in the control air passage is the same as the air pressure in the main air chamber, and the air pressure in the control air passage is smaller than the total pressure applied to the trigger valve stem. is set to be larger than the total pressure applied to the trigger valve stem when the pressure is lower than the air pressure in the main air chamber.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to FIGS. 1 to 3.

FIG. 1 shows a longitudinal section of a pneumatically driven nailer 2 incorporating a trigger device 1 of the present invention.

The members constituting the trigger device include a contact arm 8;
A trigger lever 9 and a contact lever 23 are counted.

The nailing machine 2 has a striking cylinder 4 and a striking piston 5 inside a housing 3.

The striking piston 5 is slidably and tightly fitted into the striking cylinder 4, and is integrally connected to a rod-shaped driver 6 for driving out nails.

In FIG. 1, a blowback air chamber 37 is formed around the left side of the striking cylinder 4, and a nose I is disposed coaxially with the striking cylinder 4 at the left end portion of the striking cylinder 4. The driver 6 reciprocates inside.

A contact arm 8 is disposed along the longitudinal direction of the nose 7 on the outer periphery of the nose 7, and a tip 8a of the contact arm 8 projects further to the left than the tip 7a of the nose 7.

The proximal end side of the contact arm 8 extends toward the trigger lever 9.

A cylinder cap 10 is installed on the right side of the striking cylinder 4.
is arranged, and this cylinder cap 10 is attached to the housing 3
The right end part is closed.

A main air chamber 11 that surrounds the percussion cylinder 4 and stores pressurized air in the housing 3 is formed, and the main air chamber 11 and the percussion piston formed on the right side of the percussion piston 5 in the percussion cylinder 4 are connected to each other. A head valve 12 configured between the cylinder cap 10 and the right end portion 4a of the striking cylinder 4 closes or opens the space between the right chamber 5a and the right chamber 5a.

The head valve 12 includes a substantially annular head valve cylinder 13 composed of a right end portion 4a of the striking cylinder 4, a housing 3, and a cylinder cap 10, and an annular head valve cylinder 13 that is slidably moved left and right within the head valve cylinder 13. It consists of a head valve piston 14.

Head valve piston 1 in head valve cylinder 13
Head valve piston right chamber 14a formed on the right side of 4
A control air passage 15 and a trigger valve 16 for controlling the air pressure in the right chamber 14a of the head valve piston from ON to OFF are provided between the main air chamber 11 and the control air passage 15.

The trigger valve 16 is slidably and tightly fitted into a trigger valve cylinder 19 having a communication hole 17 communicating with the main air chamber 11 and a communication hole 18 communicating with the control air passage 15. and a trigger valve stem 20.

The trigger valve stem 20 includes a first seal part 21 that opens and closes between the communication holes 17 and 18, and a second seal part 22 that opens and closes between the communication hole 18 and the atmosphere.

The operating portion 20a of the trigger valve stem 20 protrudes further leftward from the left end surface 19a of the trigger valve cylinder 19, and attaches one end 23a to the side plate 25 of the trigger lever 9 at a dynamic fulcrum No. 40 (
Therefore, it faces the pivotally supported contact lever 23.

There is a gap 2 between the operating portion 20a and the left end surface 19a of the trigger valve cylinder 19 for releasing air into the atmosphere.
6 is formed.

The other end 23b of the contact lever 23 and the base end side of the contact arm 8 face each other.

One end 9a of the trigger lever 9 is rotatably supported by the housing 3.

The trigger lever 9 includes the curved finger rest 24 and two side plates 25 erected on both sides of the finger rest 24.

This side plate 25 also functions as a stopper for regulating the top dead center of the trigger lever 9.

As shown in FIG. 1, the base end side of the contact arm 8 is
This corresponds to the right end portion of the rod portion 27.

This rod portion 27 is fitted into a contact arm guide 28 fitted into the housing 3 so as to be slidable in the left-right direction.

A flange 3.0 is provided at the left end portion of the rod portion 27.

A flange 31 is provided on the right side of the flange 30 at a certain distance.

A spacer portion 3 is provided between these flanges 30 and 31.
2 and a fitting part 33 are formed.

The diameter of this fitting portion 33 is smaller than the diameter of the spacer portion 32.

On the other hand, the tip portion 8a of the contact arm 8 is integrally connected to a connecting portion 8c formed in a diagonal shape.
A rod portion receiver 34 is formed at the right end of c.

The rod portion receiver 34 is provided with a fitting hole 35a through which the fitting portion 33 of the rod portion 27 can reciprocate in the left-right direction.

The rod part 27 and the rod part receiver 34 are compressed by a compression spring 35.
are connected via.

In this case, the insertion part 33 is fitted into the insertion hole 35a, and the spacer part 32 is larger than the diameter of the insertion hole 35a and is always located to the right of the rod part receiver 34.

On the other hand, a compression spring 36 is arranged between the housing 3 and the rod portion receiver 34 in parallel with the compression spring 35 .

This compression spring 36 urges the contact arm 8 toward the bottom dead center.

The spring force of the compression spring 35 is smaller than the total pressure applied to the trigger valve stem 20 when the communication hole 18 is connected to the atmosphere, and the communication hole 18 is connected to the atmosphere in the gap 26.
is greater than the total pressure applied to the trigger valve stem 20 when in communication through the trigger valve stem 20.

Furthermore, the spring force of this compression spring 35 is sufficiently smaller than the spring force of the compression spring 36.

Hereinafter, the operation mode of the trigger device 1 of the present invention will be explained.

First, as shown in FIG. 1, when the tip end 8a of the contact arm 8 is not pressed against the workpiece (not shown) and the trigger lever 9 is not pulled, the rod part 27 of the contact arm 8 and A compression spring 35 acts between the rod portion 27 and the rod portion receiver 34, so that the rod portion 27 moves to the right as much as possible with respect to the rod portion receiver 34, and the flange 30 is in contact with the left side of the rod portion receiver 34.

At this time, the trigger valve stem 20 also stands still at the bottom dead center, and the communication hole 18 and the atmosphere are blocked by the second seal portion 22.

From the state shown in Fig. 1, as shown in Fig. 2, the trigger lever 9 is pulled until it completely reaches the top dead center, and the contact arm 8 is incompletely operated without reaching the top dead center. Then, the contact lever 23 moves to the pivot point 4.
0 to the right and the other end 23b moves slightly to the right, the operating portion 20a of the trigger valve stem 20 moves slightly to the right, and the pressurized air in the control air passage 15 is released through the communication hole 18. begins to leak into the atmosphere.

Therefore, the total pressure applied to the trigger valve stem 20 decreases, and the spring force of the compression spring 35 becomes relatively large, as shown in FIG.
0 further to the right to completely communicate between the communication hole 18 and the atmosphere through the gap 26.

This state is maintained until the trigger lever 9 is released since the spring force of the compression spring 35 is greater than the force that moves the trigger valve stem 20 to the left.

As a result, the pressurized air in the head valve piston right chamber 14a, which is completely connected to the control air passage 15, is released, the main air chamber 11 and the striking piston right chamber 5a are communicated, and the striking piston 5 is at the bottom dead center. , and the striking piston 5 is guaranteed to remain stationary at the bottom dead center for a certain period of time.

As a result, pressurized air is stored in the blowback air chamber 37, and the striking piston 5 is smoothly returned to the top dead center.

In the above embodiment, the trigger lever 9 was pulled completely to the top dead center, and the contact arm 8 did not reach the top dead center. It was pulled to the dead center, and on the other hand,
Even when the trigger lever 9 is not pulled to the top dead center, if the trigger valve stem 20 moves slightly toward the bottom and air leaks in the control air passage 15, the compression spring 35 operates and the valve is completely closed. Trigger valve stem 2
0 to the right, this trigger valve stem 20 will be fully operational.

As described above, according to the present invention, even if either the trigger lever, the contact arm, or both are operated half-heartedly, the trigger valve stem moves completely to the top dead center and completely connects the head valve. The ON signal can be sent, thereby producing the effect that the driving stroke and return stroke of the striking piston are completed.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a pneumatically driven nailer incorporating the trigger device of the present invention, and FIGS. 2 and 3 are partially omitted longitudinal sectional views illustrating the operation of the trigger device. . 1...Trigger device, 2...Pneumatically driven nailer, 4...Blow cylinder, 5...
Impact piston, 6...driver, 7---
-Nose, 8...Contact arm, 8a...
...Tip of contact arm, 8c...
Connection part of contact arm, 9...Trigger lever-11...Main air chamber, 12...
...Head valve, 15...Control air passage, 1
6...Trigger valve, 23...Contact lever 23a...One end of contact lever, 23b...Other end of contact lever, 27
...Rod part, 35...Compression spring.

Claims (1)

[Scope of utility model registration request] A striking cylinder disposed within the nailing machine body, a striking piston integrally coupled with a rond-shaped driver that is slidably and tightly fitted into the cylinder and drives out nails, and formed on the outer periphery of the cylinder. a head valve that opens and closes between the main air chamber and the upper chamber of the striking piston of the cylinder; and a head valve that opens and closes between the main air chamber and the upper chamber of the striking piston of the cylinder; In a pneumatically driven nailer comprising a trigger valve that selectively communicates between a chamber and the atmosphere via a controlled air passage, the nailer body is positioned opposite to the trigger valve stem of the trigger valve. a trigger lever having one end pivotably supported on the trigger lever; and a contact lever disposed between the trigger lever and the trigger valve stem and having one end pivotably supported on the other end of the trigger lever. a contact arm that is reciprocally movable along a nose protruding from the nailer body and whose tip protrudes elastically from the tip of the nose; a base end of the contact arm and the contact lever; a rod portion disposed between the contact arm and the other end; and a compression spring provided between the rond portion and the base end of the contact arm;
The spring force of the compression spring is smaller than the total pressure applied to the trigger valve stem when the air pressure in the control air passage is the same as the air pressure in the main air chamber, and A trigger device for a pneumatic nailer, wherein the trigger device is set to be greater than the total pressure applied to the trigger valve stem when air pressure is lower than the air pressure in the main air chamber.