JP3915962B2 - Driving machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a driving machine for driving a stopper such as a nail using compressed air as a power source.
[0002]
[Prior art]
An example of a conventional driving machine will be described with reference to FIGS. Compressed air from a compressor (not shown) is accumulated in a pressure accumulating chamber 2 in the driving machine body 1 via an air hose (not shown). A cylindrical cylinder 3 is provided in the driving machine main body 1, and a piston 4 is supported in the cylinder 3 so as to be reciprocally movable.
[0003]
A cylindrical sleeve valve 7 is supported on the upper outer periphery of the cylinder 3 so as to be able to reciprocate. A sleeve valve chamber 10 communicating with an air passage 9 from a trigger portion (not shown) is formed below the sleeve valve 7, and the compressed air in the pressure accumulating chamber 2 is accumulated in the sleeve valve chamber 10 through the trigger portion and the air passage 9. ing. A spring 11 is provided in the sleeve valve chamber 10 to constantly urge the sleeve valve 7 upward.
[0004]
A seal member 12 is mounted on the upper portion of the sleeve valve 7, seals the upper surface portion 14 in the housing 13 at the top dead center position of the sleeve valve 7, and allows compressed air in the pressure accumulating chamber 2 to flow into the piston upper chamber 15. It is preventing.
[0005]
On the other hand, a small-diameter seal member fitting portion (hereinafter simply referred to as a fitting portion) 16 is formed on the upper portion of the cylinder 3, and the fitting portion 16 is made of an annular rubber and partially protrudes outwardly to form a seal portion 19. The sealing member 18 which comprises is fitted. The upper inner wall 22 of the sleeve valve 7 is smaller than the outer diameter of the seal portion 19, and the central inner wall 23 is set to be larger than the outer diameter of the seal portion 19. A plurality of exhaust holes 24 are provided in the central inner wall 23, and the piston upper chamber 15 communicates with the atmosphere through the passage 26 and the exhaust holes 24.
[0006]
When the trigger portion is operated, the compressed air in the sleeve valve chamber 10 is released to the atmosphere through the air passage 9 and the trigger portion, and the pressure received on the upper portion of the sleeve valve 7 by the compressed air in the pressure accumulating chamber 2 becomes the force of the spring 11. It overcomes and lowers the sleeve valve 7.
[0007]
As shown in FIG. 5, when the seal between the upper portion of the sleeve valve 7 and the upper surface portion 14 in the housing 13 is opened and the compressed air in the pressure accumulating chamber 2 flows into the piston upper chamber 15, the piston 4 descends abruptly and injection (not shown) A nail in the mouth is driven out. At the same time, the upper inner wall 22 of the sleeve valve 7 and the seal portion 19 of the seal member 18 are contact-sealed, and the space between the piston upper chamber 15, the passage 26 and the exhaust hole 24 is closed, and the compressed air in the piston upper chamber 15 flows out to the atmosphere. To prevent.
[0008]
[Problems to be solved by the invention]
When the sleeve valve 7 is lowered and the upper inner wall 22 of the sleeve valve 7 and the seal member 18 come into contact with each other in the driving machine having the above-described conventional configuration, the seal member 18 serves as the compressed air pressure of the piston upper chamber 15 and the sleeve valve. 7 receives a strong load downward due to the frictional force with the upper inner wall 22. For this reason, the leg portion of the seal member 18 may fall off from the lower end surface of the fitting portion 16, or the seal portion 19 may be turned outward to bite between the upper inner wall 22 of the sleeve valve 7. . Furthermore, the seal 19 is worn and the sealing performance with the upper inner wall 22 of the sleeve valve 7 is impaired, causing air leakage, and there is a problem in terms of durability.
[0009]
In particular, in the high-pressure specifications (operating pressure of 20 to 30 atmospheres), which has been attracting attention recently for the purpose of reducing the size and weight of the main body of the driving machine, the above-mentioned problem becomes more noticeable, so this configuration is adopted. It was difficult.
[0010]
The object of the present invention is that there is no problem such as dropping of the sealing member from the cylinder, biting between the upper inner walls of the sleeve valve, and deterioration of sealing performance due to wear of the sealing portion even in a high-pressure type driving machine. Is to provide a driving machine.
[0011]
[Means for Solving the Problems]
The above-mentioned purpose is to provide a sealing member made of a flexible material such as rubber that is provided above the cylinder and interrupts communication between the cylinder and the atmosphere by contact with and separating from the inner wall of the sleeve valve. A circular seal part is formed at the top, and an annular shape is provided with a leg part below the seal part. The leg part of the seal member is inserted into a groove provided above the cylinder, and the seal member is fitted above the cylinder. Is achieved.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described below with reference to FIGS. 1 to 3 showing an embodiment.
[0013]
Compressed air from a compressor (not shown) is accumulated in the pressure accumulating chamber 2 in the driving machine body 1 via an air hose (not shown). A cylindrical cylinder 3 is provided in the driving machine main body 1, and a piston 4 is supported in the cylinder 3 so as to be reciprocally movable. The piston 4 has a piston portion 4a and a driver blade portion 4b integrated with each other, and drives a nail 6 fed into the injection port 5 by a feeding means (not shown).
[0014]
A cylindrical sleeve valve 7 is supported on the outer periphery of the cylinder 3 so as to be able to reciprocate up and down. A sleeve valve chamber 10 communicating with the air passage 9 from the trigger portion 8 is formed below the sleeve valve 7, and compressed air in the pressure accumulating chamber 2 passes through the trigger portion 8 and the air passage 9 into the sleeve valve chamber 10. Accumulated. A spring 11 is provided in the sleeve valve chamber 10 to constantly urge the sleeve valve 7 upward.
[0015]
A seal member 12 made of an annular rubber is mounted on the upper part of the sleeve valve 7, seals the inner upper surface part 14 of the housing 13 at the top dead center position of the sleeve valve 7, and is formed on the outer periphery of the upper part of the housing 13 and the sleeve valve 7. The compressed air in the pressure accumulating chamber 2 is prevented from flowing into the piston upper chamber 15.
[0016]
As shown in FIG. 2, a small-diameter fitting portion 16 is formed in the upper portion of the cylinder 3, and a groove 17 is formed in the downward direction below the fitting portion 16. On the other hand, the seal member 18 of the present invention attached to this portion is an annular rubber having an inner diameter substantially equal to the outer diameter of the fitting portion 16, and the upper portion protrudes outwardly and has a semicircular cross-section. And the lower leg 20, and the leg 20 is inserted into the groove 17 and attached. The upper inner wall of the seal member 18 is provided with a chamfered portion 21 whose upper side is widened outwardly, and the range is formed from the apex position (seal point) of the semicircular cross-sectional seal portion 19 projecting outward to the lower side. ing. As a result, the pressure acting on the inner surface, that is, the chamfered portion 21 is increased in the pressure of the compressed air acting on the inner and outer surfaces of the seal member 18, and the seal member 18 is pushed outward.
[0017]
The upper inner wall 22 of the sleeve valve 7 is smaller than the outer diameter of the seal portion 19, and the central inner wall 23 is set to be larger than the outer diameter of the seal portion 19. A plurality of exhaust holes 24 are provided in the central inner wall 23, and the piston upper chamber 15 communicates with the atmosphere through the passage 26 and the exhaust holes 24.
[0018]
When the trigger unit 8 is operated (the operator pulls the trigger 27), the compressed air in the sleeve valve chamber 10 is released to the atmosphere through the air passage 9 and the trigger unit 8. At this time, the pressure applied to the upper portion of the sleeve valve 7 by the compressed air in the pressure accumulating chamber 2 overcomes the force of the spring 11 and lowers the sleeve valve 7. In this way, as shown in FIG. 3, the seal between the upper portion of the sleeve valve 7 and the upper surface portion 14 in the housing 13 is opened, the compressed air in the pressure accumulating chamber 2 flows into the piston upper chamber 15, the piston 4 is rapidly lowered, and is integrally connected. The nail in the injection port 5 is driven out by the driver blade portion 4b. At the same time, the upper inner wall 22 of the sleeve valve 7 and the seal portion 19 of the seal member 18 are contact-sealed, and the space between the piston upper chamber 15, the passage 26 and the exhaust hole 24 is closed, and the compressed air in the piston upper chamber 15 is released to the atmosphere. Prevent spillage. In this state, the compressed air above the seal member 18 is applied to the chamfered portion 21 formed on the inner wall of the seal member 18 and presses the seal portion 19 toward the upper inner wall 22 side of the sleeve valve 7.
[0019]
【The invention's effect】
As described above, according to the present invention, since the leg portion of the seal member is inserted into the groove provided above the cylinder and the seal member is fitted to the cylinder, the sleeve valve is lowered. There are no problems such as dropping or biting of the seal member at the time, and it can be sufficiently applied to a high-pressure specification driving machine.
[0020]
In addition, since the chamfered portion that extends to the portion located below the top of the seal portion is provided on the upper inner wall of the seal member, the seal portion is always pressed against the sleeve valve inner wall by the compressed air during sealing. Even if worn slightly, high sealing performance is maintained.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional side view showing an embodiment of a driving machine according to the present invention.
FIG. 2 is a sectional view showing a seal member and a cylinder constituting the driving machine of the present invention.
3 is a cross-sectional view illustrating a state in which a trigger portion is operated in FIG. 2 to move a sleeve valve to a bottom dead center.
FIG. 4 is a partial cross-sectional side view showing an example of a conventional driving machine.
FIG. 5 is a cross-sectional view showing a state where the trigger portion is operated in FIG. 4 and the sleeve valve is moved to the bottom dead center.
[Explanation of symbols]
2 is a pressure accumulating chamber, 3 is a cylinder, 4 is a piston, 7 is a sleeve valve, 15 is a piston upper chamber, 16 is a sealing member fitting portion, 17 is a groove, 18 is a sealing member, 19 is a sealing portion, and 20 is a leg portion. , 21 is a chamfered portion.

Claims (1)

A piston that is driven by compressed air and strikes a stopper such as a nail, a cylinder that supports the piston so that it can reciprocate, a pressure accumulation chamber that accumulates compressed air, and a cylinder that supports reciprocation on the upper outer periphery of the cylinder. A sleeve valve that interrupts communication between the chamber and the cylinder, and a sealing member that is provided above the cylinder and that is made of a flexible material such as rubber that interrupts communication between the cylinder and the atmosphere by contact with and separating from the inner wall of the sleeve valve. A driving machine provided,
The seal member is formed in a ring shape in which a semicircular cross-sectional seal portion projecting radially outward is formed upward, and a leg portion is provided below the seal portion, and the upper portion extends outward on the upper inner wall of the seal member. Form a chamfer, place the lower end of the chamfer at a level lower than the apex of the semicircular cross section of the seal, and insert the leg of the seal member into the groove provided in the reciprocating direction of the piston above the cylinder. A driving machine characterized by

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