JP3344425B2 - Pneumatic fixture driving machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pneumatic fixture driving machine such as a nailing machine.

[0002]

2. Description of the Related Art A pneumatic type in which a striking member such as a blade is driven by a piston / cylinder device using pressurized air, and a nail or other fixing tool is struck by a striking member into an object to be struck such as wood. Fixture driving machines are very well known. A typical configuration of this pneumatic fixture driving machine includes a housing for storing pressurized air, a main cylinder in the housing, and a fixed cylinder disposed in a reciprocating manner in the main cylinder and provided at a lower nose. A main piston to which a driving member for hitting the tool is connected, a stationary position for preventing supply of pressurized air to the main cylinder, and a firing position for supplying pressurized air from the upper portion of the main cylinder to the upper surface of the main piston. A main valve; and a trigger valve for controlling pressurized air to the main valve such that the main valve is positioned at the rest position when released and the main valve is positioned at the firing position when activated.

In the fastener driving machine having the above structure, the main valve, which was in the stationary position, is moved to the firing position by operating the trigger valve of the trigger device, and the main piston is rapidly moved to the lower nose side. Then, the main valve, which was in the firing position by releasing the trigger valve, is moved to the rest position to stop the supply of pressurized air to the upper surface of the main piston and to return pressurized air between the main cylinder and the housing. The pressurized air is supplied from the chamber to the lower surface of the main piston to return the main piston, and at the time of this return, the air in the main cylinder on the upper surface of the main piston is operated to be exhausted to the outside of the housing. At the time of sending the next fixture to the nose. Since such a fastener driving machine is simple and convenient, it is frequently used in construction sites.

In such a fastener driving machine, a return pressurized air chamber for storing pressurized air for return is provided outside the main cylinder in order to return the main piston. The lower hole of the cylinder communicates with the main cylinder, and pressurized air on the lower surface of the piston when the main piston is lowered is stored in the pressurized air chamber from the lower hole. At the middle height position of the main cylinder, the upper part of the pressurized air chamber communicates with the main cylinder through an O-ring serving as a check valve. When the descending main piston passes through this position, the upper part of the main piston is pressurized. Air is further supplied to the pressurized air chamber.
Therefore, air of a predetermined pressure is stored in the pressurized air chamber,
When the supply of pressurized air to the upper surface of the main piston stops,
Pressurized air in the return pressurized air chamber is supplied to the lower surface of the main piston from the lower hole of the main cylinder, and the main piston returns to the upper stationary position.

[0005]

By the way, when the main piston returns, the exhaust gas from the cylinder chamber on the upper surface side of the main piston is unnecessarily discharged outside the housing. Therefore, the conventional pneumatic fixture driving machine has a problem that the air consumption is large.

Accordingly, it is an object of the present invention to provide a pneumatic fixture driving machine that consumes less air.

[0007]

According to the present invention, there is provided, in accordance with the present invention, a driving tool which is arranged to reciprocate within a main cylinder, and which strikes a fixture at a lower nose. A main piston to which members are connected, a housing provided to cover the main cylinder from the outside and having a chamber for storing pressurized air therein, and a stationary position for preventing supply of pressurized air to the main cylinder And a main valve that moves between a firing position that supplies pressurized air from the upper part of the main cylinder to the upper surface of the main piston, and a main valve that positions the main valve at the rest position when released and the main valve at the firing position when activated. And a trigger valve for controlling the pressurized air to the main valve. To the firing position to rapidly move the main piston to the lower nose side, and then release the trigger valve to move the main valve, which was in the firing position to the rest position, to release pressurized air to the upper surface of the main piston. A pneumatic fixture driving machine for stopping supply and supplying pressurized air to the lower surface of the main piston from a hole in a lower portion of the main cylinder to return the main piston,
Exhaust from the main cylinder on the upper surface side of the piston at the time of return of the main piston passes through the main valve, and then extends from the upper part of the housing to the lower part, and the lower end side thereof passes through a return passage communicating with a lower hole of the main cylinder. And a pneumatic fixture driving machine, which is supplied to a lower surface of a main piston.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, a nail driving machine 1 as a pneumatic fixture driving machine has a housing 2 for storing pressurized air. The housing 2 is formed so as to cover the piston cylinder device from the outside, and a handle 3 for holding the nailing machine 1 is formed on the right side of the figure, and the handle 3 is provided with a trigger device 4. . A nose 7 for punching a nail as a fixture is integrally provided at a lower portion of the housing 2. The nose 7 is provided with a nail feeding section 8 on the right side of the figure, and nails are fed to the nose 7 one by one from a magazine (not shown) that houses a series of nails wound in a coil shape. It has become so.

The housing 2 includes a main cylinder 10
And a blade 1 as a driving member that is disposed so as to reciprocate in the main cylinder and hits a nail at the nose 7.
1 is connected to the main piston 12. A return pressurized air chamber 13 for storing pressurized return air is formed between the lower outer periphery of the main cylinder 10 and the inner wall of the housing 2.
Through the main cylinder. A main valve 15 is provided above the main cylinder 10 to control the supply of pressurized air to the main cylinder 10 and its stop. For this control, the main valve 15
1 is a stationary position where the supply of pressurized air to the main cylinder 10 is stopped (the position in FIG. 1), and a firing position where the pressurized air is supplied from the upper part of the main cylinder 10 to the upper surface of the main piston 12 (the position in FIG. 2). ) And move. The main valve 15 is controlled by a trigger valve 16 of the trigger device 4.

The trigger valve 16 includes a valve cylinder 17
And a valve piston 18.
Has a lower end movable between a stationary position (position in FIG. 1) and a lower firing position (position in FIG. 2). Normally, that is, at the time of release, the valve piston 18 is in a stationary position in which it is lowered downward, and pressurized air supplied to the housing 2 flows from the upper end side of the valve cylinder 17 through the gap between the valve piston 18 and the valve cylinder 17 through the passage 21. Is supplied with pressurized air.
When the valve piston 18 is pushed up to the firing position, that is, the operating position (see FIG. 2), the supply of the pressurized air to the passage 21 is stopped, and the air in the passage 21
7 is vented to the atmosphere through the lower hole.

The main valve 15 is controlled by the operation of the trigger valve 16. That is, when the trigger valve 16 is in the stationary state (stationary position state) in FIG. 1, the pressurized air from the passage 21 is supplied to the chamber 22 to push down the main valve 15 to the stationary position. next,
As shown in FIG. 2, when the pressurized air in the chamber 22 is exhausted from the passage 21 to the atmosphere by operating the trigger valve 16, the main valve 15 at the stationary position is moved to the upper firing position, and the main cylinder 15 is moved to the upper firing position. The seal with the housing 10 is released, and the pressurized air of the housing 2 is supplied to the main cylinder 10 from above. As a result, the main piston 12 is pushed down, and the main piston 12
Is rapidly moved to the lower nose side to drive the nail at the nose 7 into the object to be driven.

Then, as shown in FIG. 3, when the trigger valve 16 is released, pressurized air is again supplied to the chamber 22 through the passage 21 to push down the main valve 15 and seal the space between the main cylinder 10 and the main cylinder 10. I do. Thereby, the supply of the pressurized air from the housing 2 to the main cylinder 10 is stopped, and the pressurized air from the pressurized air chamber 13 for return is supplied from the lower hole 14 to the main cylinder 10. The pressurized air acts on the lower surface of the main piston 12 to push up the main piston 12 to return to the rest position of FIG. At this time, the air on the upper side of the main piston 12 is exhausted from the main cylinder 10 through a gap created by the main valve 15, and the exhaust is used for a mechanism according to the present invention described later. In this embodiment, a sealing cylindrical member 23 is provided on the outer periphery of the upper portion of the main cylinder,
Although the sealing function with the main valve 15 has been improved,
Since the member 23 is not essential for the present invention, a detailed description is omitted.

When the main piston 12 returns, the air in the main cylinder 10 on the upper surface side of the piston is conventionally exhausted to the outside of the housing 2 through the gap 25 of the main valve 15. In the present invention, free exhaust to the atmosphere is prevented so that the air passing through the gap 25 does not go out of the housing 2 as it is. For this reason, the air that has passed through the gap 25 is collected in one passage 32 toward the inner side surface of the housing 2. A return passage 33 is formed between the inner wall 29 and the outer wall 30 of the housing 2 and extends from the upper portion to the lower portion of the housing. The inlet of the return passage 33 communicates with the passage 32.

The inlet of the return passage 33 communicates with the passage 32, and an upper portion of the return passage 33 is provided with an opening 34 communicating with the atmosphere outside the housing 2. A throttle valve is provided in the opening 34 to adjust the air pressure supplied to the return passage 33. An outlet 35 at the lower part of the return passage 33 communicates with a return pressurized air chamber 13 provided outside the main cylinder.
Is supplied to the lower surface side of the main piston 12 through the lower hole 14 of the main cylinder 10. In the middle of the return passage 33, there is provided a check valve 36 for allowing the exhausted air to pass only from the upper portion to the lower portion. That is, the check valve 36
Prevents the pressurized air entering the pressurized air chamber 13 through the lower hole 14 of the main cylinder when the main piston 12 descends from flowing out to the upper inlet side through the return passage 33. Main valve 15 when main piston goes up
The exhaust gas that exits is supplied directly to the outlet 35 through the passage 32 and the return passage 33.

The check valve 36 comprises a valve body 37 provided on the upper side of the return passage 33. Valve body 3
7, a cylindrical body 39 and a return passage 33, as shown in FIG.
The blade piece 40 is formed so as to be able to move up and down smoothly in the inside and to receive the flow of exhaust gas to the outlet 35 side.
And an O-ring 41 provided on the upper side. The check valve 36 moves due to the difference between the pressure P applied to the upper surface of the cylindrical body 39 and the pressure P ′ applied to the lower surface of the cylindrical body 39 to perform a predetermined function.

That is, as shown in FIG. 2, when the main piston 12 is pushed down, the air pressure in the pressurized air chamber 13, the outlet 35, and the return passage 33 increases, as shown in FIG.
When the pressure P ′ applied to the lower surface of the cylindrical body 39 is larger than the pressure P applied to the upper surface of the cylindrical body 39, the pressure P ′ is pushed up to the position shown in FIG. Thus, pressurized air entering the pressurized air chamber 13 through the main cylinder lower hole 14 is prevented from escaping to the inlet side of the return passage 33. Conversely, for the return, the main piston 12 is pushed up, the exhaust from the main cylinder 10 is supplied from the passage 32 to the return passage 33, and the pressure P applied to the upper surface of the cylindrical body 39 is applied to the lower surface of the cylindrical body 39. When the pressure becomes higher than P ', the valve body 37 is pushed down as shown in FIGS.
The exhaust gas exiting is supplied to the outlet 35 through the return passage 33, replenishes the pressurized air to the pressurized air chamber, and further supplies the pressurized air to the lower surface of the main piston through the lower hole 14 so that the main piston 12 is securely moved. Raise to top dead center.

The check valve 36 is provided with a coil spring 42 below the valve body 37. The coil spring 42 presses the valve body 37 to one side so that the valve body 37 does not rattle when air pressure is not applied to the upper and lower surfaces of the valve body 37. May be.

[0018]

According to the present invention, the exhaust from the main cylinder on the upper surface side of the piston at the time of return of the main piston does not needlessly be exhausted to the outside as in the prior art, and after passing through the main valve, the upper part of the housing is removed. From the lower part of the main piston through the return passage leading to the lower hole of the main cylinder, and used to return the main piston to the rest position. Air consumption can be reduced. Further, since the exhaust gas is used, the energy efficiency is increased, and the generation of noise accompanying the exhaust gas is reduced. Further, the return passage portion can be used as a conventional pressurized air chamber for return, and in this case, the conventional pressurized air chamber becomes unnecessary. When the present invention is applied to a conventional fastener driving machine, the O-ring for a check valve can be operated without any trouble, and no modification such as removal is required.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a stationary state of a nailing machine as a pneumatic fastener driving machine according to the present invention, with a part thereof omitted.

FIG. 2 is a view similar to FIG. 1, showing a firing state of the nailing machine of FIG. 1;

FIG. 3 is a view similar to FIG. 1, showing a return state of the nailing machine of FIG. 1;

FIG. 4 is a perspective view of a check valve body.

5 is a sectional view showing a return passage and a check valve when the nailing machine of FIG. 1 returns.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 nail driving machine (pneumatic fixing tool driving machine) 2 housing 4 trigger device 7 nose 10 main cylinder 11 blade 12 main piston 13 return pressurized air chamber 14 lower hole 15 main valve 16 trigger valve 21 passage 22 chamber 25 main Valve gap 29 Inner wall of housing 30 Outer wall of housing 32 Passage 33 Return passage 34 Opening 35 Exit 36 Check valve 37 Valve body 39 Cylindrical body 41 O-ring 42 Coil spring

Claims (2)

(57) [Claims] 1. A main cylinder, a main piston connected to a driving member arranged to reciprocate in the main cylinder and hitting a fixing tool located at a lower nose, and a main cylinder covered from outside. A housing provided with a chamber for storing pressurized air therein, a stationary position for preventing supply of pressurized air to the main cylinder, and a firing position for supplying pressurized air from the upper portion of the main cylinder to the upper surface of the main piston. And a trigger valve for controlling the pressurized air to the main valve so that the main valve is located at the rest position when released and the main valve is located at the firing position when activated. By actuating, the main valve that was in the rest position is moved to the firing position, and the main piston is suddenly moved to the lower nose side Then, the main valve at the firing position is moved to the rest position by releasing the trigger valve to stop the supply of pressurized air to the upper surface of the main piston, and the main piston is moved from the hole at the bottom of the main cylinder. In a pneumatic fixture driving machine for supplying pressurized air to the lower surface and returning the main piston, the exhaust from the main cylinder on the piston upper surface side at the time of the return of the main piston passes through the main valve. A pneumatic fixture driving machine, characterized in that the lower end of the pneumatic fixture is extended from the upper part of the housing to the lower part, and is supplied to the lower surface of the main piston through a return passage communicating with a lower hole of the main cylinder. 2. In the middle of the return passage, the movement of pressurized air supplied to the lower hole of the main cylinder to the upper end side of the return passage when the main piston descends is prevented. The pneumatic fixture driving machine according to claim 1, further comprising a check valve that allows exhaust gas passing through the main valve to be supplied to the lower end of the return passage.