JPS6125986Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention provides a pneumatic impact tool or the like whose driving source is compressed air supplied from a compressor into the impact tool body via a connector such as an air hose. During the time, the compressed air is interposed in the middle of the air hose or between the air hose and the air supply hole of the impact tool main body, and is supplied from the compressor so that the air pressure of the compressed air supplied into the impact tool main body is always at a predetermined pressure. This relates to a pressure regulator that adjusts the air pressure of compressed air that is sent in.

As is generally known, a pneumatic nailer, which is an example of a pneumatic impact tool, uses compressed air supplied into the main body through a handle protruding from the side of the main body to drive a striking piston. This is a tool for driving a nail into a material to be driven by a rod-shaped driver integrally connected to the piston.

In conventional pneumatic nailers, the compressed air supplied to the main body is supplied directly from the compressor through an air hose, so that the compressed air is always stored in the main body at a constant pressure. If the air pressure of the compressed air that serves as the driving source is constant, when nails of different lengths are driven into the same nailer, the nail may be driven too far, causing damage to the surface of the material being driven into, or the nail may not be driven into the material completely.

In response to this, various pressure adjustment devices have been proposed that can adjust the air pressure of compressed air supplied into the nail gun main body to a predetermined pressure for each nail length.

One example is the above-mentioned nail gun in which a pressure regulating device is built into the handle in association with the air supply hole. However, this type requires modification of the handle of the nailing machine, which has the drawback of increasing costs.

Further, as another example, there is one in which a pressure regulating device is disposed between an air connection passage between an air supply hole provided in the main body of the nailing machine and a compressor. However, the conventional valve device of this type uses a diaphragm, which not only complicates the structure but also increases the overall size of the device.It is an accessory for pneumatic nailers that is desired to be lightweight. It is inappropriate as such.

Furthermore, in these conventional devices, the pressure is adjusted when the air pressure of the compressed air stored in the nailer body becomes lower than a predetermined pressure, and the pressure adjustment device and the compressor are connected. It is a one-way valve type in which the compressed air stored in the nail gun body remains when the air connection between the two is cut off. In this way, if the operator mistakenly turns on the operating switch of the nailer because compressed air has accumulated inside the nailer when the nailer is not in use, This is also undesirable from the point of view of the management of the nail gun, since the remaining nails may be ejected.

Therefore, the present invention has been proposed in order to eliminate the various drawbacks of the conventional regulators, and aims to simplify the structure of the regulator and reduce its size.

Another object of the present invention is to enable easy pressure adjustment.

Furthermore, the present invention makes it possible to release the compressed air remaining in the nailer body when the air connection between the nailer body and the compressor is cut off, and also reduces the exhaust noise at the time of discharge. The purpose is to achieve the following.

Hereinafter, one embodiment of the present invention will be described in detail based on the drawings.

FIG. 1 is an external side view of a pneumatic nailing machine equipped with the pressure regulator of the present invention.

As shown in FIG. 1, a handle 3 for holding the main body 2 is protruded from the side of the nail gun main body 2 of the pneumatic nail gun 1. As shown in FIG. An air supply hole 4 is formed at the rear end of the handle 3, and a main air chamber (not shown) formed in the air supply hole 4 and the nailer main body 2 is formed in the handle 3. An air passage (not shown) communicating with the inside is formed. Then, due to the air pressure of the compressed air supplied and stored in the main air chamber, the impact piston built in the nailer main body 2 moves forward within the impact cylinder, and is integrated with the piston. The connected rod-shaped driver moves forward within a nose 5 protruding from the lower end of the main body 2, and picks up the nails that have been previously fed into the nose 5 from within the magazine 6 via the nail feeding device 7. Enter. The opening/closing operation of the compressed air in the main air chamber with respect to the striking piston is performed by a trigger valve device 8 disposed at the base end portion of the handle portion 3.

In the nailing machine 1 having the above configuration, the handle portion 3
A predetermined air pressure of compressed air supplied into the main air chamber is provided between the air supply hole 4 provided in the main air chamber and an air plug 9 attached to the tip of an air hose extending from a compressor (not shown). A pressure regulator 10 is interposed to adjust the pressure.

As shown in FIGS. 2 to 5, in this pressure regulator 10, the air plug 9 is attached to one side of the main body 11, which is integrally formed by die casting, for example.
An air inlet hole 12 is bored therein, and the air inlet hole 12 is threadedly connected to the air inflow hole 12 . Further, on the other side of the main body 11, an air outlet hole 13, which is threadedly connected to the air supply hole 4, is bored coaxially with the air inlet hole 12. A piston portion 20 having an annular groove 21 on its outer periphery is disposed inside the main body 11, and a cylinder portion 30 is formed in the piston portion 20, and the cylinder portion 30 is slidably fitted tightly into the upper end outer periphery 20a of the annular groove 21. There is. A disk-shaped stopper member 14 having a diameter larger than the diameter of the piston portion 20 is disposed at a lower portion within the main body 11 . This stopper member 14 serves to catch a lower end surface 20b of the piston portion 20 when the piston portion 20 is lowered by the elastic force of a compression coil spring 50, which will be described later. The stopper member 14 is connected to a lower end opening 11 provided at the lower end of the main body 11.
It is positioned within the main body 11 by a C-hole retaining ring 15 inserted from a. Further, the piston portion 20 is provided at the center portion of the stopper member 14.
A tapered cylindrical body 16 is implanted so as to fit into an annular recess 22 formed in the center portion of the lower surface of the piston portion 20 when the piston portion 20 receives the piston portion 20 . That is, the piston portion 20 when the stopper member 14 receives the lower end surface 20b of the piston portion 20
Movement in the radial direction is prevented by the fitting between the annular recess 22 and the cylindrical body 16.

In this way, by inserting the stopper member 14 into the opening 11a, an air chamber 40 that is continuous with the inside of the cylinder portion 30 is formed in the lower portion of the main body 11.

On the other hand, an air communication hole 17 is formed on the air inflow hole 12 side of the cylinder portion 30, and the air inflow hole 12 and the inside of the annular groove 21 of the piston portion 20 are always in communication. Further, in the main body 11, the air outlet hole 13 of the cylinder portion 30 is
An air communication chamber 18 communicating with the air chamber 40 is formed between the side outer periphery and the air outlet hole 13, and the air outlet hole 13 and the air chamber 40 are always in communication.

On the other hand, an annular seal member 19 having an outer diameter larger than the diameter of the piston portion 20 is fitted into the lower end portion of the annular groove 21 of the piston portion 20 . An annular inclined surface 19 is provided at the upper end of the outer periphery of this seal member 19.
a, and the annular inclined surface 19a is raised by the air pressure of the compressed air acting on the annular groove 21 of the piston portion 20, and the upper end surface 20c of the piston portion 20 is raised. When it comes into contact with the annular step 30a formed at the upper end of the cylinder part 30, it comes into contact with the annular slope 30b formed at the lower end edge of the cylinder part 30, and the inside of the annular groove 21 and the air chamber 40 are brought into contact with each other. close the gap between

On the other hand, in the piston portion 20, a small hole 23 is formed to penetrate between the annular groove 21 and the annular recess 22 that communicates with the air chamber 40. The annular groove 21 has the small hole 2.
An O-ring 24 is fitted to close the outlet of 3.
This O-ring 24 expands in diameter when the air pressure in the air chamber 40 becomes higher than the air pressure in the annular groove 21, and the high-pressure compressed air in the air chamber 40 is passed through the small hole 23 and released little by little. It is discharged into the annular groove 21. That is, the small hole 23 and the O-ring 24 constitute a one-way valve 25.

On the other hand, a cylindrical pressure regulator 26 is screwed into the upper part of the main body 11. A compression coil spring 50 is disposed between this pressure adjustment portion 26 and an annular recess 20d formed on the upper surface of the piston portion 20, and constantly biases the piston portion 20 downward. ing. Further, an annular knob portion 27 for rotating the pressure adjustment portion 26 is fitted onto the outer periphery of the upper end side of the main body 11 via an O-ring 28.
A large number of protruding pieces 29, 29, . Note that the pressure adjusting section 26 of the main body 11 and the piston section 20 are located at the center of the upper surface of the pressure adjusting section 26 when the pressure adjusting section 26 is operated.
An air vent hole 27A is bored to prevent compression between the two.

The elastic force of the compression coil spring 50 can be variably adjusted by rotating the knob 27 to screw the pressure adjustment section 26 forward or backward. That is, the pressing force against the piston portion 20 can be adjusted.

Next, the operating state of the pressure regulator 10 having the above structure will be explained with reference to FIGS. 5 and 6.

First, the knob 27 is rotated so that the elastic force of the compression coil spring 50 pressing the piston 20 becomes equal to the air pressure of compressed air suitable for driving a predetermined nail. Then, air is passed from a compressor (not shown) through an air hose and an air plug 9, as well as an air inlet hole 12 and an air communication hole 17.
When compressed air is supplied into the annular groove 21 of the piston part 20 of the pressure regulator 10, the compressed air flows along the inner wall of the cylinder part 30 from the lower edge of the cylinder part 30 to the air chamber 40 and the air communication chamber 18. The air is then guided to the air outlet hole 13. That is, since the compressed air can always flow in a straight line, changes in the air pressure in the air outlet hole 13 due to fluctuations in the air pressure on the air inlet hole 12 side can be suppressed. This compressed air is then supplied to the main air chamber of the nailer main body 2 through the air supply hole 4 of the handle portion 3 of the nailer main body 2.

When the air pressure of the compressed air exceeds a predetermined pressure, the piston portion 20 rises as shown in FIG. 6 against the elastic force of the compression coil spring 50, and the annular groove 21 and the air chamber 40 The gap is closed by an annular seal member 19 to block the flow of compressed air toward the air outlet hole 13 side. When the air pressure in the main air chamber becomes lower than a predetermined pressure by repeatedly performing the nail driving operation of the nail gun 1, the piston section 20 is lowered by the elastic force of the compression coil puller 50, and the cylinder section 30
The contact state between the annular inclined surface 30b and the annular inclined surface 19a of the annular seal member 19 is released. Then, the compressed air stored in the annular groove 21 is again supplied into the main air chamber via the air chamber 40 and the air outlet hole 13. Note that, since the effective diameter of the annular seal member 19 that closes off the space between the annular groove 21 and the air chamber 40 is large, even if the piston portion 20 moves (descends) slightly,
The opening area between the annular groove 21 and the air chamber 40 is increased, and a large amount of compressed air can instantly flow toward the air outlet hole 13 side. Therefore, even if the air pressure of the compressed air in the main air chamber of the nailer main body 2 falls below the predetermined pressure, it can be instantly set to the predetermined pressure.

In this way, once the elastic force of the compression coil spring 50 is set to a predetermined value by rotating the knob 27, compressed air at a predetermined pressure is always supplied into the main air chamber. When driving nails of different lengths, compressed air at an air pressure suitable for driving the nail can be supplied into the main air chamber by simply rotating the knob 27.

On the other hand, when the air plug 9 is removed from the air inflow hole 12 after the nailing work is completed, the compressed air stored in the main air chamber is transferred to the inner circumferential wall of the annular recess 22 on the lower end side of the piston portion 20. It flows into the annular recess 22 through an annular gap 60 formed between the stopper member 14 and the outer peripheral wall of the cylindrical body 16 . Then, the one-way valve 25
The diameter of the O-ring 24 constituting the annular recess 22 expands due to the air pressure of the compressed air flowing into the annular recess 22, and the inside of the recess 22 communicates with the inside of the annular groove 21, that is, the atmosphere, through the small hole 23. . Then, the compressed air in the recess 22 passes through the small holes 23 and is released into the atmosphere little by little. Then, when the air pressure in the main air chamber becomes a predetermined pressure, that is, lower than the elastic force of the compression coil spring 50, the piston portion 20 is lowered by the spring force, and the annular groove 21 in the air chamber 40 is lowered. It communicates with the atmosphere through the inside. That is, the compressed air in the main air chamber of the nailer main body 2 is gradually released into the atmosphere via the pressure regulator 10. In this way, when the air plug 9 is removed from the air inflow hole 12, the compressed air stored in the main air chamber is first extracted little by little via the one-way valve 25, and then gradually extracted. Therefore, it is possible to reduce exhaust noise when compressed air is released.

As described above, according to the present invention, by rotating the pressure adjustment part and adjusting the elastic force of the spring member, the air pressure of the compressed air on the air outlet side can be adjusted to be suitable for driving a specified nail. Can be set to air pressure.
Therefore, the same nailing machine can drive several types of nails with different lengths.

In addition, once the elastic force of the spring member is adjusted, the piston part that reciprocates in a direction perpendicular to the axial direction of the air inflow hole and the air outflow hole that are coaxially formed in the pressure regulator body. The opening/closing operation is performed so that the air pressure of the compressed air flowing toward the air outlet hole becomes a predetermined pressure. Therefore, not only is the structure simpler than a valve device using a diaphragm, but the entire regulator can be made smaller. In addition, since the adjuster body can be integrally molded from a lightweight material such as aluminum alloy, it is effective as an accessory for tools that are desired to be lightweight, such as pneumatic nailers. Also,
The pressure of the pressure regulator is adjusted by rotating a pressure regulating section coaxially with the piston section in the axial direction. Therefore, since the operator can always make adjustments from above the regulator body, the adjustment operation is easy.

In addition, according to the present invention, when the supply of compressed air from the air inflow hole is cut off, the compressed air that has already been supplied to the air outflow hole is released into the atmosphere while its flow rate is reduced, which makes the exhaust noise. is attenuated.

[Brief explanation of the drawing]

Figures 1 to 6 are views showing an embodiment of the present invention, in which Figure 1 is an external side view of a pneumatic nailing machine equipped with the pressure regulator of the present invention, and Figure 2 is a pressure regulator. An enlarged front view of the regulator, Fig. 3 is an enlarged right side view thereof, Fig. 4 is an enlarged plan view thereof, Fig. 5 is an enlarged longitudinal sectional view thereof, and Fig. 6 is an enlarged longitudinal sectional view with the piston portion raised. It is a diagram. 1...Pneumatic nailer, 10...Pressure regulator,
DESCRIPTION OF SYMBOLS 11... Main body, 12... Air inflow hole, 13... Air outflow hole, 19... Annular seal member, 20... Piston part, 20a... Upper end side outer periphery of the piston part,
21... Annular groove, 25... One-way valve, 26...
...Pressure adjustment part, 30...Cylinder part, 30b...
Annular inclined surface, 40...air chamber, 50...compression coil spring.

Claims (1)

[Scope of utility model registration request] A piston part having an annular groove on its outer periphery, a cylinder part which is slidably and tightly fitted to the upper end outer periphery of the annular groove in this piston part, and a hole is bored in the outer radial direction of this cylinder part and is always in communication with the groove. an air inflow hole that is in the same position, an air outflow hole that is coaxially bored with the air inflow hole with the cylinder section in between; An air chamber that is always in communication with the air outlet hole, and an air chamber that is fitted into the lower end portion of the groove and that is connected to the air chamber when the piston portion reaches the upper end portion of the cylinder portion due to air pressure acting within the groove. an annular seal member that abuts an annular inclined surface formed on the lower end edge of the cylinder portion and closes between the air chamber and the groove; and an annular seal member formed in the annular groove of the piston portion that communicates air with the air inflow hole side. a small hole that communicates between the hole sides; a one-way valve that is interposed in the small hole and allows only air flow from the air outlet hole side to the air inlet hole side; 1. A pressure regulator for a pneumatic impact tool, etc., comprising a pressure regulator for adjusting the pressing force of a spring member that always elastically urges a piston part downward.