JPS6125987Y2 - - Google Patents

Description

[Detailed description of the invention] This invention uses compressed air as a driving source to move a striking piston that is slidably and tightly fitted into a striking cylinder, and is driven by a striking driver that is integrally connected to this striking piston. Regarding a pneumatic impact tool for driving a member to be hit into an object, particularly between the upper chamber of the piston of the impact cylinder and the main air chamber that stores compressed air for forward movement of the impact piston, or above the piston. This invention relates to an improvement in a head valve that switches between a chamber and an exhaust passage.

Conventionally, as an example of a pneumatic impact tool, there has been an impact piston integrally connected with a nail driving driver,
A striking cylinder into which the striking piston is slidably and tightly fitted; a main air chamber formed around one end of the striking cylinder to store compressed air for forward movement of the striking piston; and a chamber above the piston of the striking cylinder. A pneumatic nailing machine is known which is equipped with a head valve that opens and closes between the main air chamber and the piston upper chamber and the exhaust passage.

The head valve of the above-mentioned conventional nailing machine is an annular valve cylinder formed in a cylinder cap that closes a loading port for components such as a striking cylinder, which is opened at one end (head side) of the tool body. ,
It is comprised of an annular valve piston whose inner and outer circumferential parts are fitted in the cylinder so that they can freely reciprocate. Since both the valve cylinder and the valve piston are made of metal, an O-ring serving as a piston ring is fitted to the inner and outer peripheries of the valve piston. Further, by reciprocating the valve piston within the valve cylinder, opening and closing operations are performed between the piston upper chamber and the main air chamber, or between the piston upper chamber and the exhaust passage. edge,
A sealing member such as an O-ring is also disposed at that portion so that the closed state (sealed state) on the side to be closed is completed.

Further, a bumper member is attached to the center portion of the lower end of the cylinder cap to receive the striking piston at the end of its backward movement so that the piston does not hit the valve piston when it moves backward.

As described above, in the head valve of the conventional nailing machine described above, it is necessary to assemble the O-ring and the seal member in the place where assembly accuracy is required, and furthermore, the assembling work of the O-ring and the seal member is difficult. In addition, it is necessary to assemble the bumper member to the central portion of the lower end of the cylinder cap, which makes the assembling work complicated and requires a great deal of time.

Furthermore, the reality is that the large number of parts to be assembled increases costs.

Therefore, the present invention was proposed in order to eliminate the above-mentioned conventional drawbacks, and it is possible to provide a sealing function to the valve piston itself constituting the head valve, and a bumper function to catch the striking piston at the end of the reciprocating motion. The purpose is to reduce the number of parts to be assembled, shorten assembly work time, and reduce costs.

Hereinafter, one embodiment of the present invention will be described in detail based on the drawings. Note that this embodiment is applied to a pneumatic nailing machine.

As shown in FIG. 1, a percussion cylinder 3 is disposed inside the nailer main body 2 of this pneumatic nailer 1, and a percussion piston 4 is tightly fitted into the percussion cylinder 3 so as to be able to freely reciprocate. ing. A nail driving driver 5 is integrally connected to the striking piston 4 via a parallel pin 6.

The driver 5 is operated to reciprocate within a nail driving nose 7 which is protruded from the lower end of the nail gun main body 2 in the figure by the reciprocating movement of the impact piston 4. Note that this nose 7 also serves as a guide hole for the driver 5.

Compressed air for moving the striking piston 4 forward (downward in the figure) is supplied to a hollow grip portion 8 protruding from one side (right side in the figure) of the nailer main body 2.
The air is stored in a main air chamber 9 formed inside and around one end side (upper end side in the figure) of the impact cylinder 3.

Compressed air is supplied to the main air chamber 9 by connecting an air hose extending from an air compressor (not shown) to an air plug block 10a provided in a grip cap 10 that covers the rear end 8a of the grip portion 8. It is constantly supplied and stored through the grip section 8. The grip portion 8 is located below the rear end 8a of the grip portion 8.
A relief valve 11 is provided to keep the air pressure inside constant.

This relief valve 11 has a valve cylinder 12
and a valve piston 13 that is reciprocatably housed within the cylinder 12.
is always pressed upward by the compression coil spring 14, that is, in the direction of the opening 15 communicating with the inside of the grip 8, and when the air pressure in the grip 8 reaches a predetermined pressure, the opening 15 is closed. are doing. Then, when the air pressure inside the grip section 8 exceeds a predetermined pressure, the piston 13 is pushed down by the air pressure at this time against the elastic force of the spring 14, causing the compression inside the grip section 8. Air is discharged from the opening 15 through the cylinder 12 and into the atmosphere from the lower end opening 16.

On the other hand, a trigger valve 17 is installed on the front end 8b side of the grip portion 8 and serves as a switch mechanism for reciprocating the striking piston 4.

This trigger valve 17 is composed of a trigger valve cylinder 18 made of a rubber material disposed on the upper end 8c side of the grip portion 8, and a trigger valve stem 19 slidably housed inside the trigger valve cylinder 18. has been done. The trigger valve cylinder 18 is connected to a cylinder cap 3 which will be described later.
The upper chamber 21 of the trigger valve is always in communication with the communication hole 20 to the atmosphere opened in 1, and the upper chamber 36A of the head valve piston described later and the air passage 22.
The lower chamber 23 of the trigger valve communicates with the lower chamber 23 through the lower chamber 23 of the trigger valve. The trigger valve stem 19 has, from the upper end side in the figure, a first piston part 19a that opens and closes between the valve upper chamber 21 and the valve lower chamber 23, a small diameter joint stem part 19b, and a flange part 24. The second piston 19c and the operating stem portion 19d are formed in this order, and between the lower end of the valve cylinder 18 and the flange portion 24 is a compression coil that constantly urges the entire trigger valve stem 19 downward in the figure. spring 25
is mediated. Then, the operation stem section 1
9d protrudes outward from the lower end 8d of the grip portion 8 so as to face a trigger lever 27 rotatably supported on one side of the nailer main body 2 with a support shaft 26 as a fulcrum.

That is, by rotating (pulling up) the trigger lever 27 counterclockwise in the figure with the support shaft 26 as a fulcrum, the trigger valve stem 19 is moved against the elastic force of the coil spring 25. When pushed up, the first piston portion 19a plunges into the trigger valve upper chamber 21, thereby establishing communication between the valve upper chamber 21 and the trigger valve lower chamber 23. Then, the compressed air that had been supplied into the head valve piston upper chamber 36A is released into the atmosphere through the air passage 22, the trigger valve lower chamber 23, the trigger valve upper chamber 21, and the communication hole 20, and the head valve piston The upper piston chamber 36A is at atmospheric pressure. Then, when the pulling operation of the trigger lever 27 is released, the entire trigger valve stem 19 returns to its original position by the elastic force of the coil spring 25, and the first piston portion 19a moves above the trigger valve. The space between the chamber 21 and the trigger valve lower chamber 23 is closed. Then, the compressed air in the grip section 8 enters the head valve piston upper chamber 36A through the notch recess 28 formed in the second piston section 19c, as well as through the trigger valve lower chamber 23 and the air passage 22. supply again. A finger hook 29, which also serves as a stopper for the trigger lever 27, is formed in the lower end 8d of the grip 8.

On the other hand, the head of the nailer main body 2 (upper end in the figure)
includes a component loading port 30 for assembling and loading the striking cylinder 3 and striking piston 4 into the main body 2;
The loading port 30 is closed by a cylinder cap 31 which also serves to position and fix the impact cylinder 3 within the main body 2.

An ON/OFF signal is received from the trigger valve 17 between the lower end side of the cylinder cap 31 and one end side of the impact cylinder 3, and the piston upper chamber 4A of the impact cylinder 3 and the main air chamber are connected to each other. 9 or between the piston upper chamber 4A and the exhaust passage 32 provided at the upper end of the cylinder cap 31. The exhaust passage 32 is formed between the cylinder cap 31 and a plate-shaped exhaust cover 34 disposed above the cylinder cap 31.

As shown in FIG. 2, this head valve 33 consists of a head valve cylinder 35 formed within the cylinder cap 31 and an annular head valve piston 36 tightly fitted into the head valve cylinder 35 so as to be able to reciprocate. . This head valve piston 36 is integrally molded from a rubber material, and has a sealing function itself. Note that the head valve piston according to the present invention may have a reinforcing aggregate installed therein, and at least the surface portion thereof may be formed of a rubber material.

The head valve piston 36 is a small diameter piston portion 36 that is tightly fitted into an inner cylinder portion 35a provided in the center of the cylinder cap 31.
a, and a large-diameter piston part 36b that is tightly fitted into an outer cylinder part 35c that is connected to the inner cylinder part 35a with an annular step part 35b as a boundary, and the exhaust passage 32 is connected to the central part in the axial direction. An exhaust gas conduit 37 is provided which communicates with the. Note that, when the striking piston 4 reaches the end of the backward movement, a protrusion 38 protruding from the center portion of the upper end surface 4a of the striking piston 4 enters into this exhaust guide path 37.

In the state before operation, the head valve piston 36 is pushed downward in the figure by the pressure of compressed air in the grip section 8, which is supplied to the head valve piston upper chamber 36A via the trigger valve 17. The large diameter piston portion 36
The lower end surface 39 of b is one end edge 3 of the striking cylinder 3.
a to close (seal) the space between the piston upper chamber 4A and the main air chamber 9. On the other hand, when the trigger lever 27 is pulled up, the head valve piston upper chamber 36A becomes atmospheric pressure via the trigger valve 17, and the head valve piston 36 acts on the lower end surface 39 of the large diameter piston portion 36b. The upper end surface 40 of the small-diameter piston portion 36a comes into contact with the lower end surface 41 of the exhaust cover 34, causing the piston upper chamber to 4A and the exhaust passage 32 is closed (sealed). At this time, the compressed air in the main air chamber 9 suddenly flows into the piston upper chamber 4A from between the pushed-up head valve piston 36 and one end edge 3a of the striking cylinder 3, and Operate forward. Then, the driver 5 moves the nail 1 previously supplied into the nose 7.
00 is driven out from the tip 7a of the nose 7 and driven into a material to be driven (not shown). In addition, the above-mentioned striking piston 4
The lower end surface 4b of the impact cylinder 3 is received at the forward end by an annular bumper member 42 made of a rubber material and arranged on the other end side of the impact cylinder 3. When the striking piston 4 reaches the end of its forward movement, the compressed air in the main air chamber 9 supplied into the piston upper chamber 4A passes through the small hole 43 formed in the striking cylinder 3 and enters the striking cylinder. A return air chamber 4 formed around the other end side of 3
It is supplied and stored within 4. Note that the space between the return air chamber 44 and the main air chamber 9 is sealed by a seal unit 48 formed by sandwiching an annular seal member 45 between a pair of annular support plates 46 and 47. ing. The seal unit 48 has one support plate 46 side received by an annular step 50 protruding from the outer periphery of the impact cylinder 3, and the other support plate 47 side having a cylindrical shape protruding from the lower end of the cylinder cap 31. It is pressed downward in the figure by a stopper member 51 and is positioned and fixed. Further, the striking cylinder 3 is positioned and fixed within the nail gun main body 2 by the engagement relationship between the seal unit 48 and the stopper member 51. The stopper member 51 is provided with a plurality of air passage holes 52, 52 distributed in the circumferential direction through which the compressed air in the grip portion 8 always flows into the main air chamber 9.

When the trigger lever 27 is released from the raised state, the head valve piston upper chamber 36A
The compressed air in the grip portion 8 is again supplied into the grip portion 8 through the trigger valve 17 to push the head valve piston 36 downward in the figure. At this time, a compression coil spring 53 is disposed within the head valve piston upper chamber 36A so that the head valve piston 36 can easily return. Then, the lower end surface 3 of the large diameter piston 36b
9 is in contact with one end edge 3a of the striking cylinder 3;
The space between the piston upper chamber 4A and the main air chamber 9 is closed (sealed), and the contact between the upper end surface 40 of the small diameter piston portion 36a and the lower end surface 41 of the exhaust cover 31 is released. Then,
The compressed air in the piston upper chamber 4A is discharged into the atmosphere through the exhaust passage 37 and the exhaust passage 32 provided in the head valve piston 36. Then, the impact piston 4 is transferred to the lower end surface 4b of the piston 4 via the return air passage 54 provided at the other end of the impact cylinder 3.
The reciprocating operation is performed by the air pressure of the compressed air in the return air chamber 44 acting on the return air chamber 44. and,
The striking piston 4 is received at the end of its backward movement by the head valve piston 36, which also serves as a bumper. In addition, the head valve piston 3
Since the piston 6 is made of a rubber material, the impact force when the striking piston 4 hits the piston 36 is absorbed.

On the other hand, on the back side of the lower end of the nailer main body 2, there are nails 100 driven out by the forward movement of the driver 5,
A long magazine 60 into which 100 . . . are loaded is disposed. In addition, each of the above nails 100, 100...
Adjacent portions of... are connected with adhesive or the like to form a long connecting nail 101.

This magazine 60 includes a long magazine body 61 that is integral with the nose 7 and extends to the rear end 8a side of the grip portion 8, and a magazine that is slidable along the lower edge 61A of the magazine body 61. The base 62 and the magazine main body 61
The nails 100, 100 loaded therein are pushed into the nose 7 by the elastic force of the compression coil spring 63.
It is composed of a pusher 64 that presses in the direction.

The magazine base 62 is the magazine body 6
Nail loading port 6 opened over the entire length of the lower end of 1
It serves as a lid for opening and closing 1B. That is, the nail 10 is attached to the magazine body 61.
0,100..., slide the magazine base 62 toward the rear end of the magazine body 61, turn the entire nailer 1 upside down so that the nail loading port 61B faces upward, and load the nail 10.
Since the nails 100 can be loaded from above, loading the nails 100 into the magazine body 61 is easy.

Further, on the rear end 61a side of the magazine main body 61, a nail 10 loaded in the magazine main body 61 is provided.
A lock that engages with a pin 65 provided at the rear end 62a of the magazine base 62 to prevent the magazine base 62 from jumping out rearward due to the repulsive force of the pusher 64 that presses 0,100... A lever 66 is provided. When loading the nails 100, 100, .

Further, the lower end surface 62A of the magazine base 62
a leg portion 67 for adjusting the driving depth of the nail 100;
67 are arranged at predetermined intervals in the longitudinal direction of the base 62. These leg parts 67, 67 are molded from a rubber material, and the above-mentioned magazine base 62
It is screwed into threaded portions 68, 68 protruding from the lower end surface 62A of. That is, each of the leg portions 67,
67 independently of each other, the distance between the tip 7a of the nose 7 and the surface of the material to be driven can be variably adjusted, and the nail 1 to be driven into the material to be driven can be variably adjusted.
This is to variably adjust the implantation depth of 00.

As described above, as is clear from the description of the above embodiments, the present invention is applicable to a head valve that opens and closes between the piston upper chamber of a striking cylinder and the main air chamber or between the piston upper chamber and the exhaust passage. Since the head valve piston itself has both a sealing function and a bumper function, the number of parts is fewer than before, and the work of assembling the head valve piston into the tool body is easier, reducing the assembly time. Can be done.
Furthermore, the number of parts is reduced, leading to lower costs.

[Brief explanation of the drawing]

FIG. 1 is a schematic side sectional view of a pneumatic nailing machine showing an embodiment of the present invention, and FIG. 2 is an enlarged sectional view of the vicinity of the head valve. 1...Pneumatic nailer, 2...Nailer body, 3
...Blow cylinder, 4...Blow piston, 4A...
... Piston upper chamber, 5... Impact driver, 9...
Main air chamber, 33...Head valve, 3
5...Head valve cylinder, 36...Head valve piston.

Claims (1)

[Scope of utility model registration request] A striking piston to which a striking driver is integrally connected, a striking cylinder in which the piston is tightly fitted so as to be able to reciprocate, and a main air chamber formed around one end of the cylinder and storing compressed air for forward movement of the striking piston. and a head valve, which is composed of a valve piston and a valve cylinder, and opens and closes between the piston upper chamber of the striking cylinder and the main air chamber or between the piston upper chamber and the exhaust passage. In the type impact tool, at least the surface portion of the valve piston of the head valve is integrally molded with a rubber material so that the valve piston itself can have a sealing function, and a bumper function for receiving the impact piston at the end of forward movement. A head valve for a pneumatic impact tool, characterized in that it can have a