JPH0744460Y2 - Pneumatic driving machine trigger valve - Google Patents

Description

[Detailed Description of the Invention] [Field of Use of the Invention] The present invention relates to a trigger valve of a pneumatic driving machine that uses a pneumatic power source to drive a fastener such as a nail into a material to be driven.

[Background of the invention]

A conventional driving machine will be described with reference to FIGS. 4 and 5. A cylinder valve 5 for opening and closing the upper surface of the cylinder 2 is provided above the cylinder 2 in which the piston 3 integrated with the driving rod 7 slides in a sealed manner, and pressurized air is instantaneously introduced into the cylinder 2 to lower the piston 3. . Normally, pressurized air via the trigger valve 12 is applied to the upper part of the cylinder valve chamber 8, and the cylinder valve 5 closes the upper surface of the cylinder 2. When the trigger plunger 11 is pushed, the pressurizing chamber passage 10 above the trigger plunger 11 is first closed. Push further to trigger plunger
The pressurized air trapped in the cylinder valve chamber 8 is discharged from the fitting gap between the valve bush bottom surface 30 and the valve bush 11. If the exhaust area at this time is not sufficient, the piston 3 will move down before the cylinder valve 5 is fully opened instantaneously, so that a high effective pressure does not occur on the upper surface of the piston 3. On the contrary, if the exhaust diameter of the trigger plunger 11 is increased and the exhaust area is increased, the pressing force applied to the trigger plunger 11 by the pressurized air when pushing up the trigger plunger 11 becomes too large, making it difficult to push with the force of a finger. Become. Further, when the pressurized air in the cylinder valve chamber 8 is exhausted, the pressurized air in the main pressure chamber 6 also leaks.

[Purpose of device]

SUMMARY OF THE INVENTION The present invention provides a trigger valve for eliminating the above-mentioned drawbacks of the prior art and improving the opening / closing speed of the cylinder valve.

[Outline of device]

The present invention focuses on the fact that the pressurizing air is communicated not only to the upper surface of the trigger plunger but also to the rear surface thereof, so that the pressure applied by the pressurized air is the difference between the upper surface and the lower surface. Even if the diameter of is increased and the exhaust area is increased to several times the normal size, the pressure applied to the trigger plunger is devised so that it remains unchanged.

[Example of device]

An embodiment of the present invention will be specifically described below with reference to the drawings.

FIG. 5 shows a pneumatic driving machine to which the present invention is applied. A cylinder 3 housed in a main body 1 internally has a piston 3 slidably fitted therein, and a striking rod 7 is integrally connected to the piston 3. A cylinder valve 5 that opens and closes the main pressurizing chamber 6 and the inside of the cylinder 2 by operating a trigger 13 is provided above the cylinder 2. A cylinder valve chamber 8 is hermetically formed above the cylinder valve 5.
When the trigger 13 is pushed up, the trigger plunger 11 sliding on the inner wall of the trigger valve 12 is pushed, and the pressure chamber passage 10 leading to the main pressure chamber 6 is closed. The cylinder valve chamber 8 communicates with a trigger valve 12 via a valve passage 9. Normally, the cylinder valve 5 closes the upper surface of the cylinder 2 by the pressurized air in the cylinder valve chamber 8.

1 to 3 are detailed views of the trigger valve 12 of the present invention. FIG. 1 shows a normal state in which the trigger plunger 11 is located at the bottom dead center, and the main pressurizing chamber passage 10 and the valve passage 9
Communicate with each other via the upper part 27 of the trigger valve chamber to form the air passage 26 as shown in FIG. 1, and the cylinder valve 5 is closed in this state.

Fig. 2 shows the state where the trigger plunger 11 is pushed to the middle,
The pressurizing chamber passage 10 is sealed by the O-ring 14 for the air intake valve inserted in the small diameter upper portion 25 of the plunger, and is shut off from the main pressurizing chamber 6. In this state, the upper part 27 of the trigger valve chamber has an O-ring 20 on the outer diameter part of the valve bush 29 and a large diameter part 22 of the plunger.
It is sealed with the upper O-ring 15 of. The lower part 28 of the trigger valve chamber is sealed by an O-ring 21 inside the valve bush 29 and an O-ring 16 for the exhaust valve of the large diameter portion 22 of the plunger. The upper part 27 of the trigger valve chamber and the lower part 28 of the trigger valve chamber communicate with each other through a through hole 17. At the position of the trigger plunger 11 described above, there are times when the pressurized air in the cylinder valve chamber 8 remains trapped and times when it is exhausted.

Figure 3 shows the trigger plunger 11 pushed to the end.
O-ring 16 for exhaust valve with pressure chamber passage 10 kept closed
Is open, the pressurized air in the cylinder valve chamber 8 is exhausted through the valve exhaust hole 18 via the lower part 28 of the trigger valve chamber 28 and the air passage 26 in FIG. Opened instantly with pressurized air in chamber 6.

With the above configuration, the diameter of the exhaust valve portion is increased, so that it is possible to generally secure an exhaust area which is several times as large as that when exhausted from the plunger small diameter lower portion 23. Also the trigger plunger
The pushing-up force of 11 is the pressing force applied to the plunger small diameter lower portion 23 in FIG. 1, and the pressing force applied to the plunger small diameter upper portion 25 in FIGS. 2 and 3, both being the pressing force of only the small diameter portion. Further, since the exhaust valve O-ring 16 is opened after the intake valve O-ring 14 is closed, the pressurized air in the main pressurizing chamber 6 is prevented from leaking.

[Effect of device]

According to the present invention, the exhaust area of the exhaust valve can be increased without changing the operating force of the trigger by canceling the pressure applied between the upper chamber and the lower chamber of the trigger plunger, so that the cylinder valve can be opened. The speed is increased and the effective pressure on the piston can be increased. Further, since the intake valve of the main pressurizing chamber is closed and the exhaust valve of the cylinder valve chamber is opened, the pressurized air in the main pressurizing chamber does not leak.

[Brief description of drawings]

FIG. 5 is a sectional view showing an embodiment of the trigger valve of the pneumatic driver of the present invention, FIGS. 1 to 3 are detailed sectional views of the trigger valve portion of FIG. 5, and FIG. 4 is a conventional trigger. It is a detailed sectional view showing an example of a valve. In the figure, 1 is a main body, 2 is a cylinder, 3 is a piston,
4 is a piston upper chamber, 5 is a cylinder valve, 6 is a main pressurizing chamber, 7 is a striking rod, 8 is a cylinder valve chamber, 9 is a valve passage, 10 is a pressurizing chamber passage, 11 is a trigger plunger, 12 is a trigger valve. , 13 is a trigger, 14 is an O-ring for the intake valve, 15
Is O-ring for plunger, 16 is O-ring for exhaust valve,
Reference numeral 17 is a through hole, 18 is a valve exhaust hole, 19 is a valve spring, 20 and 21 are bush O-rings, 22 is a plunger large diameter portion, 23 is a plunger small diameter lower portion, 24 is a bush inner wall, 25 is a plunger small diameter upper portion, 26 Is an air passage, 27 is an upper part of the trigger valve chamber, 28 is a lower part of the trigger valve chamber, 29 is a valve bush, and 30 is a bottom face of the valve bush.

Claims (1)

[Scope of utility model registration request] 1. A cylinder valve that opens and closes by operating a trigger valve is provided on an upper portion of a cylinder on which a piston integrally connected with a striking rod slides, and when a trigger plunger of the trigger valve is pushed up, a cylinder valve is provided in an upper chamber of the cylinder valve. Pressurized air in a certain cylinder valve chamber is exhausted, and the cylinder valve is opened by the pressurized air in the main pressurizing chamber in the space of the main body, and the pressurized air flows into the cylinder to give a striking force to the piston. In the insert machine, the trigger plunger has a plunger small diameter upper part that fits into a pressure chamber passage leading to the main pressure chamber, a plunger large diameter part that fits into an inner wall of a valve bush that slides and guides the trigger plunger, and the valve. The lower part of the plunger that fits into the bottom hole of the bush is integrally formed with the inside of the trigger valve. It is divided into a trigger valve chamber upper part and a trigger valve chamber lower part by the diameter part,
The upper part of the trigger valve chamber and the lower part of the trigger valve chamber are communicated with each other through a hole penetrating the large diameter part of the plunger, and when the trigger plunger is further pushed up, the small diameter upper part of the plunger is sealed and then the pressurized air is supplied from the lower part of the trigger valve chamber. A trigger valve for a pneumatic driving machine, characterized in that the air is exhausted.