JPH08276374A - Nailing machine equipped with single/continuous drive switch-over mechanism - Google Patents

Abstract

PURPOSE: To enhance operability and operating performance by letting a nailing machine be switched over between single drive and continuous drive depending on a working condition in the nailing machine driving scattered nails mainly used by construction works by a succession of impacts. CONSTITUTION: A nailing machine main body 1 driving a nail 34 by a succession of impacts is equipped with a piston 3 capable of being slid up and down within a cylinder 2, a head valve opening/closing the cylinder 2 and a pressure accumulating chamber 7, a trigger valve 11 pumping the compressed air of the head valve 5 through an air passages 10 and 12, and with a repeating valve 27 which senses change in pressure at the lower side of the piston 3 by way of air passages 13 and 16 from a return air chamber 14, and thereby opens/closes the air passages 10 and 12. The nailing machine main body is also equipped with a single/continuous drive switch-over valve 15 opening/closing the air passages 13 and 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention operates a switching valve to reciprocally move a piston and a driver blade each time a trigger such as a nail or the like is operated to make a single impact and to make a large number of triggers. It is possible to switch between single-shot multiple hits by multiple hits by operation and automatic repeat multiple hits in which the piston and driver blade are automatically reciprocated while the trigger is being operated to hit the stopper with multiple hits. The present invention relates to a driving machine having a single-shot continuous hit switching mechanism.

[0002]

2. Description of the Related Art As a conventional example of a single shot multiple hitting type driving machine, Japanese Patent Application Laid-Open No. 5-16077 previously filed by the present applicant will be cited and described with reference to FIG. When the nail 34 is inserted into the nail guide 23 and the tip 34a of the nail is pressed against a driven material (not shown), the nail head 34b pushes the push lever 25 upward to unlock the trigger 24. When the trigger 24 is pulled in this state, the trigger valve 11 operates,
The compressed air in the head valve upper chamber 8 is released to the atmosphere via the air passage 32. Therefore, the head valve 5 rapidly rises, compressed air flows in above the piston 3, the piston 3 and the driver blade 21 rapidly descend, and the nail 34 in the nail guide 23 is driven into the material to be driven. When the trigger 24 is released while the nails 34 remaining after being driven remain in the nail guide 23, the head valve 5 is lowered, and the piston 3 and the driver blade 21 return to the top dead center in the figure. By repeating this operation several times, the nail 34 in the nail guide 23 can be driven flush with the material to be driven.

Next, as a conventional example of an automatic repeat multi-hit type driving machine, Japanese Patent Laid-Open No. 172683/1990 will be cited and described with reference to FIG. When the tip end of the push lever 25 is pressed against a driven material (not shown), the push lever 25 moves up to unlock the trigger 24. When the trigger 24 is operated, the trigger valve 11 is opened, and the compressed air in the head valve upper chamber 8 is released to the atmosphere via the air passages 10 and 12. Therefore, the head valve 5 rises sharply and opens,
Compressed air in the pressure accumulating chamber 7 flows into the cylinder 2, the piston 3 and the driver blade 21 rapidly descend, and the nail 34 inserted in the tail cover 33 is driven into the material to be driven. The air below the piston 3 of the cylinder 2 flows into the return air chamber 14 through the communication hole 19. When the piston 3 passes through the communication hole 20 provided with the check valve 26, the compressed air above the piston 3 of the cylinder 2 flows into the return air chamber 14 from the communication hole 20. A part of the compressed air that has flowed into the return air chamber 14 passes through the air passage 13 and the repetitive valve upper chamber 1
When 7 is reached, the repetitive valve 27 descends and the air passage 1
0 is cut off from the air passage 12.

Since the head valve upper chamber 8 and the pressure accumulating chamber 7 are communicated with each other through the air passage 16 provided in the head valve 5, the compressed air in the pressure accumulating chamber 7 flows into the head valve upper chamber 8 and the air. The pressure in the passage 10 increases. Repeat valve 2
7 does not rise because the lower pressure receiving area S1 is smaller than the upper pressure receiving area S2.
The state that the gap is cut off is maintained. On the other hand, the head valve 5 is lowered by the pressing force of the head valve spring 28 as the pressure of the head valve upper chamber 8 rises, shuts off the cylinder 2 and the pressure accumulating chamber 7, and removes the air above the piston 3 in the cylinder 2 from the exhaust valve 6 to the atmosphere. To release. Therefore, the return air chamber 1
The compressed air of 4 returns the piston 3 to the initial top dead center. Due to the expansion of the air, the pressure of the return air chamber 14 becomes low, and the pressure of the communicating repetitive valve upper chamber 17 also becomes low, and the pressure of the repetitive valve lower chamber 9 raises the repetitive valve 27, and the head valve upper chamber 8 and The compressed air in the air passage 10 is released to the atmosphere via the trigger valve 11. The passage areas of the air passages 16 are equal to those of the air passages 10 and 12
Since it is set to be sufficiently smaller than the passage area of No. 2, the amount of air discharged from the trigger valve 11 is larger than the amount of air filled from the air passage 16, and the pressure in the head valve upper chamber 8 drops rapidly. When the pressure in the head valve upper chamber 8 drops, a series of operations such as raising and driving of the head valve 5 are performed again as described above. Then, while the trigger 24 is being operated, the nail 34 is hammered into the material to be hammered by repeatedly striking the nail 24 many times.

[0005]

In the above-described single-shot multi-hit type driving machine, especially when the nail 34 is thick and long or the material to be driven is hard, the number of times of hitting increases and the trigger 2
There was a problem that I had to operate 4 for the number of times of driving, and I got tired. Further, in the automatic repeat multiple impact type driving machine, since the hammer is automatically impacted many times while operating the trigger 24, the nail 34 is driven when the nail 34 is driven into an unstable and easily driven driven material. When you work while checking whether the nail material is misaligned or whether the nail 34 is driven straight and surely,
There is a problem that the nail 34 is driven into the end while being bent. The object of the present invention is to solve the above problems,
This is to improve the operability and workability of this type of driving machine.

[0006]

The above object can be achieved by providing an automatic repetitive multiple impact driving machine with a stop mechanism by external operation of a head valve or a repetitive valve.
The stop mechanism includes an externally operable single-shot continuous switching valve that opens and closes an air passage between the return air chamber and the repetitive valve. Alternatively, the repetitive valve is provided with a single-shot continuous switching operator that can be externally operated at a reciprocable position or a fixed position.

[0007]

With the above-described driving machine, it is possible to arbitrarily switch to single-shot or continuous operation by an external operation according to the work situation. Therefore, it is possible to reduce fatigue caused by operating the trigger for only a single shot many times, and it is possible to reduce the displacement of the material to be driven and the bending and driving of the nail, which is caused only by continuous hammering.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention is shown in FIGS. Compressed air from a compressor (not shown) is stored in the pressure accumulating chamber 7 of the driving tool body 1. The driving machine body 1 is provided with a cylindrical cylinder 2,
A piston 3 is provided in the cylinder 2 so as to be vertically slidable. A piston ring 4 is provided on the outer circumference of the piston 3 to seal between the cylinder 2 and the piston 3. A head valve 5 is provided on the upper end of the cylinder 2, and when the head valve 5 rises, the upper end of the cylinder 2 opens and the exhaust valve 6 closes, the pressure accumulating chamber 7 communicates with the upper side of the piston 3 of the cylinder 2, and the head valve 5 descends. The upper end of the cylinder 2 is closed and the exhaust valve 6 is opened, so that the upper side of the piston 3 of the cylinder 2 communicates with the atmosphere. The head valve upper chamber 8 communicates with the repetitive valve upper chamber 9 via the air passage 10, and the repetitive valve upper chamber 9 and the trigger valve 11 communicate with the air passage 1
It communicates via 2. The return air chamber 14 and the single-shot continuous switching valve 15 of the present invention (hereinafter simply referred to as switching valve) communicate with each other through the air passage 13, and the switching valve 15 and the repetitive valve lower chamber 17 communicate with each other through the air passage 16. ing.

When the switching valve 15 is in the one-shot position shown in FIG. 2, the air passage 13 and the air passage 16 are shut off, the air passage 16 communicates with the atmosphere, and the switching valve 15 is in the continuous position shown in FIG. At times, the air passage 13 and the air passage 16 are in communication with each other. Head valve upper chamber 8 and accumulator chamber 7
Communicate with each other through the air passage 18, and the passage area of the air passage 18 is sufficiently smaller than the passage areas of the air passages 10 and 12.

On the other hand, the cylinder 2 is provided with a communication hole 20 provided with a communication hole 19 and a check valve 26 in the same manner as in the conventional case so as to communicate with the return air chamber 14.

A piston 3 is provided at the nail ejection portion of the driving machine body 1.
Blade guide 22 that guides the driver blade 21 integrally connected with the blade guide 22 that guides the nail 34.
Insert the nail guide 23 that slides up and down along the nail and the nail 34 into the nail guide 23 and press it against the driven material (not shown) to move upward while being guided by the blade guide 22 to unlock the trigger 24. A push lever 25 is provided.

Next, the driving operation by the driving machine having the above construction will be described with reference to FIGS. Nail 34 to nail guide 2
When the nail tip 34a is inserted into the workpiece 3 and pressed against the material to be driven, the nail head 34b pushes up the push lever 25, and the upper end of the push lever 25 unlocks the trigger 24. When the trigger 24 is pulled in this state, the compressed air in the head valve upper chamber 8 is released from the trigger valve 11 via the air passages 10 and 12, the head valve 5 rises, and the compressed air rapidly rises in the piston of the cylinder 2. 3 and the driver blade 21 integrated with the piston 3 suddenly descends. The driver blade 21 drives the nail 34 in the nail guide 23 while descending to the piston bottom dead center. The air below the piston 3 of the cylinder 2 flows into the return air chamber 14 through the communication hole 19. Moreover, the piston 3 has a communication hole 20.
After passing through, the compressed air above the piston 3 of the cylinder 2 flows into the return air chamber 14 from the communication hole 20. With the above flow, one driving stroke is completed.

First, the operation when the switching valve 15 is in the single-shot position after the driving stroke is completed will be described. Since the air passage 13 and the air passage 16 are shut off from each other, the repetitive valve 27 does not operate and the piston 3 is maintained in the bottom dead center position. Contrary to the previous operation, when you release the trigger 24,
The trigger valve 11 returns to the state of FIG.
And the exhaust valve 6 is opened to discharge the compressed air above the piston 3 of the cylinder 2, the piston 3 and the driver blade 21 return to the top dead center by the compressed air accumulated in the return air chamber 14. The push lever 25 and the nail guide 23 descend as shown in FIG. 1 to lock the trigger 24. With the above operation, the nail driving operation for one cycle is completed, but when the energy required for nail driving is larger than the output energy of the driving machine body 1, the nail 34 remains without being completely driven into the material to be driven. The following actions are required. That is, nail 3
Insert the nail guide 23 into 4 and push lever 25
Push up to unlock the trigger 24 and
pull. The above operation is repeated until the nail 34 is flush with the material to be driven.

Next, the operation when the switching valve 15 is in the continuous position after the driving stroke is completed will be described. Since the air passage 13 and the air passage 16 are in communication with each other, when the compressed air flowing into the return air chamber 14 flows into the repetitive valve lower chamber 17, the repetitive valve upper chamber 9 is at atmospheric pressure, so that the repetitive valve 27 rises. The air passage 10 and the air passage 12 are shut off from each other. Further, since the head valve upper chamber 8 and the pressure accumulating chamber 7 communicate with each other via the air passage 18, the compressed air in the pressure accumulating chamber 7 flows in and the pressures in the head valve upper chamber 8 and the air passage 10 rise. . Since the upper pressure receiving area S1 is smaller than the lower pressure receiving area S2, the repetitive valve 27 keeps the air passage 10 and the air passage 12 blocked. On the other hand, the head valve 5 is lowered by the pressing force of the head valve spring 28 as the pressure of the head valve upper chamber 8 rises, shuts off the cylinder 2 and the pressure accumulating chamber 7, and the air above the piston 3 of the cylinder 2 is discharged from the exhaust valve 6 to the atmosphere. discharge.

Therefore, the compressed air in the return air chamber 14 returns the piston 3 to the initial top dead center. Due to the expansion of air, the pressure in the return air chamber 14 becomes low, and the pressure in the repetitive valve lower chamber 17 in communication also becomes low. The pressure in the repetitive valve upper chamber 9 causes the repetitive valve 27 to descend, and the compressed air in the head valve upper chamber 8 and the air passage 10 is released to the atmosphere via the trigger valve 11. Since the passage area of the air passage 18 is set to be sufficiently smaller than the passage areas of the air passages 10 and 12, the trigger valve 11 discharges more than the air filling of the air passage 18, and the head valve upper chamber 8 of The pressure drops rapidly. When the pressure in the head valve upper chamber 8 drops, a series of operations such as raising and driving of the head valve 5 are performed again as described above. Then, the nail 34 is driven into the material to be driven by repeatedly striking it many times.

FIG. 4 shows another embodiment of the present invention in which the switching lever 29 is in the single-shot position. In the case of a single shot, the repetitive valve 27 is mechanically fixed to the lower position by the tip of the switching lever 29. Therefore, the repeater valve lower chamber 1
Even if the compressed air from the air chamber 14 flows back to 7, the repetitive valve 27 does not rise. Switching lever 2 for continuous hammering
The tip end of 9 is operated so as to be positioned above, and the repetitive valve 27 is automatically reciprocated as in the above embodiment.

FIG. 5 shows another embodiment of the present invention in which the switching valve 15 is in the single-shot position. The air passage 13 and the air passage 16 are always in communication, the bypass valve 27 is bypassed in parallel with the air passage 10 and the air passage 12, and the head valve 5
An air passage 30 and an air passage 31 are provided so that the trigger valve 11 communicates with each other, and a switching valve 15 is provided between the air passage 30 and the air passage 31. Switching valve 15
Is in the single-shot position, the air passage 30 and the air passage 31 communicate with each other, and the compressed air from the return air chamber 14 pushes the repetitive valve 27 to the upper position to shut off the air passage 10 and the air passage 12. Since the compressed air flowing in from the air passage 18 is discharged from the trigger valve 11 via the air passage 30 and the air passage 31, the repetitive valve 27 does not automatically reciprocate. Therefore, the head valve 5 maintains the raised state. When the switching valve 15 is in the continuous position, the air passage 30 and the air passage 31 are shut off, and the repetitive valve 27 automatically reciprocates to perform continuous impact as in the above embodiment.

[0018]

According to the present invention, since the single-shot continuous-shot switching mechanism is added to the automatic repeat multiple impact driving machine, it is possible to arbitrarily switch to single-shot or continuous operation according to the working situation. Therefore, it is possible to reduce fatigue caused by pulling the trigger many times for only single shots, and to reduce misalignment of the material to be driven and bending of nails due to only continuous shots.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a driving tool of the present invention.

FIG. 2 is a sectional view for explaining the driving tool of the present invention, showing a state in which the switching valve is in a single-shot position.

FIG. 3 is a sectional view for explaining the driving tool according to the present invention, showing a state in which the switching valve is in the continuous position.

FIG. 4 is a sectional view showing another embodiment of the driving tool of the present invention.

FIG. 5 is a sectional view showing another embodiment of the driving tool of the present invention.

FIG. 6 is a cross-sectional view showing an example of a conventional single-shot multiple impact driving machine.

FIG. 7 is a cross-sectional view showing an example of a conventional automatic repeat multiple impact driving machine.

[Explanation of symbols]

1 is a driver main body, 2 is a cylinder, 3 is a piston, 5 is a head valve, 6 is an exhaust valve, 7 is a pressure accumulating chamber, 8 is a head valve upper chamber, 9 is a repetitive valve upper chamber, 10, 12, 13,
Reference numerals 16 and 18 are air passages, 11 is a trigger valve, 14 is a return air chamber, 15 is a single-shot continuous switching valve, 17 is a repetitive valve lower chamber, 27 is a repetitive valve, and 29 is a switching lever.

Claims (3)

[Claims] 1. A pressure accumulating chamber for accumulating compressed air, a piston reciprocally provided in a cylindrical cylinder, and compressed air in the pressure accumulating chamber is introduced into the atmosphere above the piston in the cylinder. A head valve that alternately operates, a repetitive valve that repeatedly controls the head valve in conjunction with the operation of the head valve or the reciprocating motion of the piston, and a trigger valve that controls the head valve or the repetitive valve are provided. In the driving machine, in which the head valve automatically repeats itself by the operation of the head valve and the repetitive valve linked to the operation of the piston, and the piston automatically reciprocates to drive the stopper into the material to be driven, wherein the head valve or the repetitive valve is operated. A driving machine having a single-shot continuous hammering switching mechanism, characterized in that the automatic reciprocating of the can be stopped by an external operation. 2. An air passage for transmitting a pressure change under the piston to the repetitive valve is provided with an externally operable single-shot continuous switching valve for opening and closing the air passage. A driving machine with a single-shot continuous-shot switching mechanism. 3. The driving machine having a single-shot continuous shot switching mechanism according to claim 1, further comprising an externally operable single-shot continuous shot switching operator for preventing the repetitive valve from closing.