JPS6240775Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is an air consumption saving device for a pneumatic nailer.
More specifically, the present invention relates to an air consumption saving device that controls the supply and stop of air from an air supply source in conjunction with the movement of a head valve that operates a nail driving piston of a pneumatic nail gun.

Generally, pneumatic nailers are accompanied by an air supply source such as an air compressor, but recently they have become easier to handle.
Portable air supply sources with good workability have come to be preferred, and as a result, air supply sources are also becoming more compact by reducing tank capacity. However, since the air supply source supplies driving air to the nailer, it is not possible to reduce the tank capacity alone regardless of the air consumption of the nailer. Air tank miniaturization is difficult to accomplish without efficiently consuming and achieving savings in nail gun air.

On the other hand, a pneumatic nailer is continuously supplied with air from an air supply source, and the introduced high-pressure air is temporarily stored within the machine. Conventionally, this accumulated air was consumed as shown in FIG. First, high-pressure air introduced from an air supply source is stored in the main chamber 2, and when the nail tip is brought into contact with the material to be driven during operation, and when the trigger is pulled, the head valve 4 moves upward to open the main chamber 2. An air supply port 10 opens between the chamber 2 and the driving piston cylinder 3, and a large amount of driving air instantly flows into the cylinder 3 from the main chamber 2, causing the driving piston 11 to descend. At this time, air (atmospheric pressure) below the piston 11 is compressed and flows into the return air chamber 17 through the large hole 18 at the bottom of the cylinder 3. Further, after the driving piston 11 passes through the small hole 19 of the cylinder 3, a part of the high-pressure driving air is supplied from the small hole 19 into the return air chamber 17 as supplementary air for returning the piston.

Next, when the contact is released or the trigger is released, the head valve 4 moves downward to open the air supply port 1.
Block 0. At this time, the exhaust port 22 opens, all the air in the cylinder 3 is released from the exhaust port 22 to the atmosphere, and the pressure in the cylinder 3 is reduced. Along with this, the air in the return air chamber 17 is transferred to the cylinder 3.
It flows into the interior, expands in volume, and pushes the driving piston back up.

When driving air flows into the cylinder 3 from the main chamber 2, the driving piston 11 reaches the bottom dead center within the first few milliseconds. During the subsequent 10 milliseconds, part of the drive air in the main chamber 2 is supplied to the return air chamber 17 as supplementary air. Normally, the air required to drive the driving piston 11 as described above can be sufficiently supplied by the accumulated air stored in the main chamber 2 in advance. However, the main chamber 2 is always supplied with air from an air supply source such as an air compressor, and when air flows into the cylinder 3 of the driving piston 11 at the start of the driving stroke and the main chamber 2 is depressurized, A pressure difference is generated between the internal pressure of the main chamber 2 and the supply pressure of the air supply source 1, so that high-pressure air is continuously introduced into the main chamber 2 from the air supply source 1 and is further replenished into the cylinder 3. However, since the driving piston 11 reaches the bottom dead center in a few milliseconds, the air that is subsequently replenished into the cylinder 3 is not directly related to the driving of the piston 11. In addition, part of the replenished air flows into the return air chamber 17 and is used for returning the piston, but the remaining air in the cylinder 3 is moved downward by the head valve 4 to the driving piston 11. When the gas returns, all of it is released into the atmosphere.

This idea was developed in view of the above circumstances.
The purpose of the present invention is to propose an air consumption saving device for a pneumatic nailing machine that can suppress wasteful consumption of air by controlling the supply of air from an air supply source in particular in conjunction with a head valve. .

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 2, reference numeral A indicates a pneumatic nailer. This nailing machine uses air supplied from an air supply source 1 such as an air compressor to a main chamber 2.
A supply port for supplying this air to the nail driving piston cylinder 3 is opened and closed by a head valve 4, and between the air supply source 1 and the main chamber 2, there is a connection between the air supply source 1 and the main chamber. Air supply control valve 5 that controls air inflow to 2
The air supply control valve 5 and the head valve 4 are connected to the trigger valve 15 through the air flow paths 26 and 23, respectively, and the head valve 4 is opened by operating the trigger valve 12. When the head valve 4 is closed, the air supply control valve 5 shuts off the air supply source 1 and the main chamber 2, and when the head valve 4 is closed, the air supply control valve 5 shuts off the air supply source 1 and the main chamber 2. It is meant to communicate.

Next, the pneumatic nailing machine A will be explained in more detail. As the air supply source 1, an air compressor is usually used. The air sent from this air supply source 1 is sent to the main chamber 2 in the main body of the nailer A.
It is introduced into the cylinder 3, where the pressure is accumulated, and supplied into the driving piston cylinder 3 as required. main chiyamba 2
An air supply port 10 is provided between the cylinder 3 and the cylinder 3, and the supply port 10 is opened and closed by a head valve 4. A nail driving piston 11 is fitted within the cylinder 3. The piston 11 is equipped with a driver 12, and the tip of the driver 12 faces the nail injection port 13. A nail magazine 14 is installed in the nail injection port 13.
The nails 16 inserted therein are sequentially loaded by spring pressure. Further, an annular return air chamber 17 is formed around the nail tip side of the cylinder 3, and the air chamber 17 and the cylinder 3 communicate with each other via a lower large hole 18 and an upper small hole 19 formed in the partition wall. are doing.

To operate the pneumatic nailer A, pull the trigger 20, bring the tip of the nail 16 into contact with the material to be driven (not shown), and move the contact arm 21 backward; the trigger valve 15 is activated. Then, the head valve 4 becomes open, and the air supply port 10 opens. A large amount of the accumulated air in the main chamber 2 flows into the cylinder 3, so that the driving piston 11
When the driving piston 11 descends, a part of the air (atmospheric pressure) under the piston 11 is compressed. When the driving piston 11 passes through the upper small hole 19 and reaches the bottom dead center, part of the air that has flowed into the cylinder 3 from the main chamber 2 flows into the return air chamber 17 from the lower large hole 18. The air flows into the return air chamber 17 through the small hole 19.

Next, release the contact with the nail tip or trigger 20
When released, the trigger valve 15 is activated and the head valve 4 is closed, while the air outlet 22 is opened and the driving air in the cylinder 3 is released to the atmosphere, and the air in the return air chamber 17 is released. As a result, the driving piston 11 returns to its original position.

As mentioned above, the operation of the driving piston 11 is directly controlled by opening and closing the head valve 4, and when the head valve 4 is open, the driving stroke is performed, and the pressure accumulated in the main chamber 2 is reduced. Since air is supplied into the cylinder 3, the internal pressure of the main chamber 2 is reduced by that amount, and therefore a pressure difference is created between it and the supply pressure of the air supply source 1. Moreover, when the driving piston 11 descends rapidly, the air inflow capacity inside the cylinder 3 becomes relatively large.
The air pressure acting on the piston 11 when it reaches the bottom dead center is lower than the acting pressure when the air supply port 10 is open. Therefore, a pressure difference also occurs between the main chamber 2 and the cylinder 3, and the introduction of air from the air supply source 1 is encouraged. However, an air supply control valve 5 is provided in the air introduction section between the air supply source 1 and the main chamber 2, and is operated in conjunction with the opening/closing operation of the head valve 4 by operating the trigger valve 15. The valve 5 becomes closed when the head valve 4 is opened and the driving piston 11 is driven, and prevents air from being introduced from the air supply source 1 into the main chamber 2. Further, the air supply control valve 5 becomes open when the head valve 4 is closed and the driving piston 11 returns, and the air supply control valve 5 resumes introducing air from the air supply source 1 to the main chamber 2.

Next, the configuration and operation of the air supply control valve 5 will be explained.

First, a valve chamber 6 is provided at the air introduction part from the supply source 1 to the main chamber 2.
An air supply control valve 5 is fitted therein so as to be able to freely reciprocate. The valve chamber 6 is constructed by connecting a first valve chamber 6a that communicates with the air supply source 1 and the main chamber 2, and a second valve chamber 6b that communicates with the trigger valve 15 via an air flow path 23. ,
Correspondingly, the air supply control valve 5 is also configured to have a head portion 5a disposed within the first valve chamber 6a and a body portion 5b disposed within the second valve chamber 6b. The head portion 5a opens and closes the air introduction port 31 between the air supply source 1 and the main chamber 2, and a sealing material 24 made of synthetic rubber, synthetic resin, etc. is attached to the inside thereof. On the other hand, the body part 5b operates by keeping the second valve chamber 6b and the first valve chamber 6a in a sealed state, and is linked to the opening/closing operation of the head valve 4, and reduces the spring pressure of the compression spring 25. is recieving. Furthermore, since the upper surface of the head section 5a is exposed to the first valve chamber 6a communicating with the air supply source 1, a downward biasing force is generated on the head section 5a by the air pressure from the air supply source 1. There is. On the other hand, the lower surface of the body portion 5b has a second valve chamber 6 communicating with the trigger valve 15.
Since the body portion 5b is exposed to the side 5b, not only the above-mentioned spring pressure but also air pressure from the main chamber 2 acts on the body portion 5b via the trigger valve 15, and an upward biasing force is generated. The above-mentioned mutually opposite biasing forces are configured to be able to be reversed. Normally, the upward biasing force acting on the body portion 5b is large and the air supply control valve 5 is stationary upward, but when the air supply control valve 5 is reversed, it is directed downward. The biasing force prevails and the valve 5 moves downward. The above-mentioned reversal of the biasing force is effected by a change in the air pressure applied to the body portion 5b that occurs in conjunction with the opening and closing of the head valve 4.

That is, the head valve 4 is connected to the air flow path 2.
Similarly, the air supply control valve 5 also communicates with the trigger valve 15 via an air flow path 23 . Therefore,
The head valve 4 and the air supply control valve 5 communicate with each other via the trigger valve 15, and the air supply control valve 5 is connected to the head valve 4 by the air control operation of the trigger valve 15.
and the air supply control valve 5 are interlocked.

First, under normal conditions, exhaust air from the valve housing 27 of the trigger valve 15 to the outside is blocked, and the air flow path 26 from the main chamber 2 to the upper chamber 30 of the head valve 4 and the second valve chamber of the air supply control valve 5 are closed. Air flow path 2 leading to 6b
3 is open. For this reason, main chamber 2
The high pressure air inside is supplied to the head valve upper chamber 30 and the second valve chamber 6b. The air in the head valve upper chamber 30 acts on the upper surface of the head valve 4 together with the spring pressure of the compression spring 32. The lower surface of the valve 4 is exposed within the main chamber 2 and receives the working pressure of air in the opposite direction to the upper surface, but before the start of operation, it remains stationary downward due to the downward biasing force against the upper surface, and the head valve 4 is in a closed state, blocking the air supply port 10. on the other hand,
At this time, the air supplied to the second valve chamber 6b also acts on the lower surface of the body portion 5b of the air supply control valve 5 together with the spring pressure of the compression spring 25, and the biasing force causes the valve 5 to stand still as described above. The air inlet 31 is opened, and the air inlet 31 is opened.
Air is introduced into the main chamber 2 from the air supply source 1 through the main chamber 2, and the pressure is accumulated.

Next, when the contact arm 21 is brought into contact with the driving material and the trigger 20 is pulled during operation, the trigger stem 28 of the trigger valve 15 is activated.
is pushed into the housing 27 and the housing 27
The exhaust passage is opened, and the head valve upper chamber 30 and the second valve chamber 6b are exposed to the atmosphere, and at the same time, the supply of air from the main chamber 2 to the valve housing 27 is cut off. Therefore, the pressure in the head valve upper chamber 30 is reduced, and the head valve 4 moves upward to the open state because the upward biasing force becomes larger, opening the air supply port 10 and driving the driving piston 11. be done. On the other hand, since the second valve chamber 6b is also depressurized at the same time, the biasing force on the air supply control valve 5 is reversed, and the downward biasing force on the head portion 5a becomes larger, causing it to move downward and become closed. The air inlet 31 is closed. This prevents air from being introduced from the air supply source 1 into the chamber 2.

Thereafter, when the contact arm 21 is released or the trigger 20 is released, the trigger valve stem 28 of the trigger valve 15 moves downward again, blocking the exhaust passage in the valve housing 27 as described above. At the same time, the air flow paths 26 and 23 from the main chamber 2 to the head valve upper chamber 30 and the air supply control valve chamber 6b are opened. Therefore, the head valve 4 is closed and the air supply port 10 is closed. On the other hand, since air pressure is applied to the lower surface of the body portion 5b of the air supply control valve 5, the biasing force against the valve 5 is reversed again, the valve 5 moves upward and becomes open, and the air inlet 3
1 opens, the introduction of air from the air supply source 1 resumes, and air necessary for the next nail driving is accumulated in the main chamber 2. Repeat the same action thereafter.

As mentioned above, the head valve 4 and the air supply control valve 5 are interlocked through the operation of the trigger valve 15, so that when the head valve 4 is in the open state, the air supply control valve 5 is in the closed state, and the head valve 4 is in the open state. - When the valve 4 is in the closed state, the air supply control valve 5 is in the open state. Therefore, when the head valve 4 is opened and the driving piston 11 is driven, the air supply control valve 5 is closed and the introduction of air from the air supply source 1 is inhibited. The air introduction continues until the head valve 4 is closed, the driving piston 11 is returned to its original position, and the air supply control valve 5 is opened. Therefore, one cycle of the driving piston 11 is performed only by the accumulated air in the main chamber 2.

Note that stopping the introduction of air from air supply source 1 is as follows:
Preferably, this is carried out when the driving piston 11 reaches the bottom dead center, that is, several milliseconds after the start of driving. The slow speed at which the air supply control valve 5 starts operating is related to the difference in biasing force that acts in the opposite direction on the control valve 5 due to a change in air pressure against the body portion 5b. If this difference is large, the reaction when the biasing force is reversed will be slow, and the valve will start operating sooner. Therefore, the timing at which the air supply control valve 5 starts operating is determined by adjusting the difference in the effective pressure-receiving area between the head 5a and the body portion 5b, the spring pressure of the compression spring 25, etc., and adjusting the difference in biasing force. be able to.

As explained in detail above, the present invention links the air supply control valve that controls the introduction of air from the air supply source into the main chamber of the pneumatic nailing machine with the head valve that controls the driving of the driving piston. , the air supply source and the main chamber are shut off when the head valve is open, and the air supply source and the main chamber are communicated when the head valve is closed, so the drive piston is driven by the main chamber. Even if the air pressure of the accumulated air decreases as the piston is driven, the introduction of air from the air supply source is stopped. Therefore, wasteful consumption of air is suppressed, and it is possible to achieve a reduction in air consumption of about 10 to 20% compared to the conventional method, which is very useful in practice.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view showing the operating state of a conventional pneumatic nailing machine, and FIG. 2 is a longitudinal sectional view of the pneumatic nailing machine showing an air consumption saving device according to the present invention. Symbol A: pneumatic nailer, 1: air supply source, 2: main chamber, 4: head valve, 5: air supply control valve, 5a: head section, 5b: body section, 6 ...Valve chamber, 10...
...Air supply port.

Claims (1)

[Scope of utility model registration request] A pneumatic nailing machine that stores air supplied from an air supply source such as an air compressor in a main chamber, and uses a head valve to open and close the supply port that supplies this air to the nailing piston cylinder. An air supply control valve for controlling air inflow from the air supply source to the main chamber is provided between the air supply source and the main chamber, and an air supply control valve is provided between the air supply control valve and the head.
The valves each communicate with a trigger valve through an air flow path, and when the head valve is in an open state by operating the trigger valve, the air supply control valve shuts off the air supply source and the main chamber. . An air consumption saving device for a pneumatic nailing machine, wherein the air supply control valve allows communication between an air supply source and a main chamber when the head valve is in a closed state.