JP4428218B2 - Dust-proof filter device for compressed air tools - Google Patents

Description

  The present invention relates to a compressed air tool in which an air motor is rotationally driven by compressed air to perform screw tightening, bolt tightening, or drilling, and in particular, compression that prevents dust or the like from entering a valve or an air motor of the compressed air tool. The present invention relates to a dustproof filter device for a pneumatic tool.

  Impact of rotating the air motor with compressed air supplied from the air compressor and rotating the driver bit, socket or drill bit with the rotational force of the air motor to perform tightening or drilling of screws or bolts In a tool such as a driver, compressed air supplied into the tool via an air plug attached to the rear end of a grip portion for gripping the tool is supplied to an air motor via a throttle valve that is operated by operating a throttle lever. And the air motor is driven to rotate. In such a tool such as a screwdriver, a wrench or a drill, compressed air supplied to the tool through the air plug attached to the rear end of the grip portion is passed through an air passage formed inside the grip portion. It supplies to the throttle valve via.

In an air-driven nailing machine that uses compressed air as a power source to impact the nail impactfully, an air plug attached to the rear end of the grip portion of the nailing machine, an air plug attached to one end of the air hose, Garbage such as sand and dust adhering to the socket and the like enters the nailing machine when the nailing machine is connected to the compressed air supply source via the air hose. In order to prevent malfunctions and malfunctions of cylinders, etc., a plate-shaped dust filter is installed in the grip part where the air plug is attached, and dust such as sand and dust that has entered the grip part from the air plug side is removed. A filter that is captured by this filter and prevents entry into a valve or a striking cylinder is known.
JP 2003-89076 A

  In a nailing machine in which compressed air is supplied into a striking cylinder and a piston accommodated in the striking cylinder is instantaneously driven to drive a nail, a large capacity air chamber is formed in the grip portion. The piston is instantaneously driven by the compressed air supplied into the air chamber to drive the nail. Therefore, an increase in the flow resistance of the compressed air by the dustproof filter mounted in the grip portion is not a significant problem. However, in a compressed air tool such as an impact driver in which an air motor is driven to rotate by compressed air to drive a driver or a drill, the tool is driven for a relatively long time, and during this time, a large amount of air is continuously applied to the air motor. Since the compressed air supplied to the air tool through the air hose is supplied to the air motor, the flow resistance in the air flow path is increased. It becomes a big problem because it becomes impossible to supply the compressed air.

  A compressed air tool such as an impact driver is formed to be relatively small compared to the nailing machine described above, and the diameter of the flow path formed in the grip portion is also thin. Therefore, if a dustproof filter with a fine mesh is installed to prevent the passage of fine dust in this flow path, the dustproof filter increases the flow resistance of the compressed air and restricts the supply of compressed air to the air motor. May reduce the performance. It is possible to increase the flow rate by increasing the outer shape of the dustproof filter to increase the effective area, but it is also necessary to increase the outer shape of the grip part, which makes it difficult to grip the tool and impairs workability. There is a problem of end.

  The present invention solves the above-described problems in the prior art, and does not require an increase in the flow diameter of the compressed air formed inside the grip portion, and can provide sufficient compressed air to the air motor. An object of the present invention is to provide a dustproof filter device.

  To achieve the above object, a dust filter apparatus for a compressed air tool according to the present invention includes an air motor that is rotationally driven by compressed air and supplies compressed air supplied from a compressed air supply source to the air motor via a throttle valve. In the compressed air tool configured to rotationally drive the air motor, an opening for communicating the inside and outside of the valve housing is formed in the outer peripheral wall of the hollow valve housing forming the throttle valve, and the valve A cylindrical dust-proof filter is attached to the outer peripheral surface or inner peripheral surface of the housing where the opening is formed, and compressed air from a compressed air supply source is supplied to the part of the valve housing where the dust-proof filter is mounted. The compressed air supplied into the supply passage is arranged to face the supply passage. Through the filter and the opening, characterized in that so as to supply to the air motor is introduced inside the valve housing.

  In the dust filter device for a compressed air tool of the present invention, an opening for communicating the inside and the outside of the valve housing is formed on the outer peripheral wall of the hollow valve housing forming the throttle valve, and the opening of the valve housing is formed. A dust-proof filter formed in a cylindrical shape is attached to the outer peripheral surface or the inner peripheral surface, and a portion of the valve housing where the dust-proof filter is attached is placed in a supply passage to which compressed air from a compressed air supply source is supplied. Since the compressed air supplied in the supply passage is introduced into the inside of the valve housing through the dustproof filter and the opening and supplied to the air motor, the grip portion is formed. Even if the diameter of the supply passage is small, the dust resistance filter does not increase the flow resistance, and sufficient compressed air is supplied to the air motor. Never continuously thus degrade the performance of the tool can be supplied. In addition, since it is not necessary to increase the diameter of the pipe line formed in the grip portion, it is not necessary to increase the outer shape of the grip portion, and it is possible to form a grip shape that is easy to grip according to the shape of the tool. It becomes possible and does not impair workability.

  In addition, since the dust-proof filter formed in a cylindrical shape is mounted on the outer peripheral surface of the valve housing, the dust-proof filter is bent by the pressure of compressed air and detached from the mounting portion like a conventional plate-shaped dust-proof filter. Therefore, the dustproof filter formed in a cylindrical shape can be attached simply by fitting it to the outer periphery of the cylindrical valve housing, and the number of processing steps and assembly steps of parts for fixing the dustproof filter can be reduced.

  The object of the present invention is to provide a dustproof filter device capable of supplying sufficient compressed air to an air motor without increasing the diameter of the compressed air supply passage formed in the grip portion. An opening for communicating the inside and outside of the valve housing is formed on the outer peripheral wall of the valve housing, and a dust-proof filter formed in a cylindrical shape is attached to the outer peripheral surface or the inner peripheral surface of the valve housing. The part of the valve housing to which the dustproof filter is mounted is disposed so as to face the supply passage to which the compressed air from the compressed air supply source is supplied, and the compressed air supplied into the supply passage is disposed in the dustproof filter. And is introduced into the inside of the valve housing through the opening and supplied to the air motor. Describing Do the following examples.

  FIG. 1 is a sectional side view showing an impact driver as an example of a compressed air tool in which a dustproof filter device of the present invention is implemented. The impact driver 1 has a grip portion 3 for gripping and operating the impact driver 1. An integrally formed housing 2 is provided, and an air motor 4 that is rotationally driven by compressed air supplied into the impact driver 1 and an impact mechanism 6 that is driven by the air motor 4 are accommodated in the housing 2. Has been. The output shaft 5 of the air motor 4 is connected to the impact mechanism 6 so as to rotate the impact hammer 7 of the impact mechanism 6, and the impact hammer 7 is driven to rotate via the air motor 4 to hit the anvil 8. A shocking rotational force is transmitted to the anvil 8. The front end portion of the anvil 8 is disposed so as to protrude from the end portion on the other end side of the housing 2 to the outside of the housing 2, and a chuck portion for detachably attaching a driver bit to the front end portion of the anvil 8. 9 is formed.

  At the rear end of the grip portion 3, an air plug 10 for connecting an air hose connected to a compressed air supply source to the impact driver 1 and an exhaust port 11 for discharging exhaust air exhausted from the air motor 4 to the atmosphere. The compressed air for driving the air motor 4 is supplied into the impact driver 1 through the air plug 10. The grip portion 3 is formed in a hollow shape, and in the hollow portion of the grip portion 3, a supply passage 12 for supplying compressed air supplied through the plug 10 to the air motor 4, and the air motor 4. An exhaust passage 13 is formed in parallel to guide exhaust air exhausted from the air motor 4 to the exhaust port 11 after driving.

  A throttle valve 15 for supplying the compressed air supplied in the supply passage 12 to the air motor 4 is formed at the base of the grip 3, and is close to the base of the grip 3 of the housing 2. By operating the throttle lever 16 that is rotatably supported by the portion with a hand holding the grip portion 3, the throttle valve 15 is operated so that the compressed air in the supply passage 12 passes through the communication passage 14. The air motor 4 is rotated and supplied to the air motor 4 to rotate.

  As shown in FIGS. 2, 3, and 4, the grip portion 3 is formed with a recess extending from the lower side of the grip portion 3 to the upper side of the grip portion 3 through the exhaust passage 13 and the supply passage 12. The throttle valve 15 includes a hollow valve housing 17 accommodated in the recess. An opening 18 is formed on the outer peripheral wall of the upper portion of the valve housing 17 so that the hollow space of the valve housing 17 communicates with the supply passage 12. The upper end of the valve housing 17 faces the supply passage 12. The compressed air in the supply passage 12 is introduced into the hollow of the valve housing 17 through the opening 18.

  In the hollow of the valve housing 17, compressed air that has entered the valve housing 17 from the opening 18 formed in the upper portion of the valve housing 17 is passed through an opening 19 formed in the peripheral wall of the central portion of the valve housing 17. A hollow sleeve valve 20 that opens and closes to supply or shut off the supply to the communication passage 14 is disposed. Between the opening 18 formed at the upper end of the valve housing 17 and the opening 19 communicating with the communication passage 14, an annular flange 21 bulging in the inner diameter direction is formed. By fitting the O-ring 22 attached to the sleeve valve 20 to the annular flange 21, the compressed air supplied from the opening 18 into the valve housing 17 is blocked from being supplied to the air motor. Further, when the sleeve valve 20 is operated upward so that the O-ring 22 is detached from the annular flange 21, the compressed air supplied into the valve housing 17 from the opening 18 is opened to the opening 19 and the communication passage 14. The air motor 4 is supplied via The sleeve valve 20 is urged by a spring 23 in a direction in which the O-ring 22 is fitted into the annular flange 21.

  The sleeve valve 20 is formed in a hollow shape, and an opening 24 is formed in the peripheral wall of the upper end portion of the sleeve valve 20 so as to communicate between the hollow of the sleeve valve 20 and the supply passage 12. The compressed air in the supply passage 12 is always supplied into the sleeve valve 20 through the. Further, an air flow path 25 is formed in the hollow of the sleeve valve 20 so that the inner diameter increases in a tapered shape upward, and a spring 26 is provided in the tapered air flow path 25. A ball valve 27 urged toward the direction with a smaller inner diameter is disposed. The ball valve 27 is disposed so as to be in close contact with the inner peripheral wall of the inner part of the air passage 25 where the inner diameter of the air passage 25 is small by the spring 26 at the normal time, and the air passage 25 is blocked. By operating upward along the tapered air passage 25 against the urging force, the communication air is supplied to the compressed air supplied into the sleeve valve 20 through an opening 20 a formed in the peripheral wall of the sleeve valve 20. 14 is supplied to the air motor 4.

  The clearance between the ball valve 27 and the inner peripheral surface of the air passage 25 becomes larger as the ball valve 27 moves upward in the drawing from the inner part of the air passage 25 formed in a tapered shape. The flow rate of the supplied compressed air is made variable so that the rotational speed of the air motor can be arbitrarily controlled.

  An operating stem 28 for operating the ball valve 27 and the sleeve valve 20 is slidably disposed in the hollow of the sleeve valve 20. A lower end portion of the operation stem 28 protrudes from an end portion of the valve housing 17 and is disposed so as to face the throttle lever 16, and the operation stem 28 can be slid by rotating the throttle lever 16. I am doing so. The upper end of the operation stem 28 is arranged to face the ball valve 27, and when the operation lever 28 is slid by rotating the throttle lever 16, the ball valve 27 is moved by the tip of the operation stem 28. It operates so that it may move away from the inner part of the air passage 25. Further, the operating stem 28 is formed with a flange portion 29 that can be engaged with the end face of the sleeve valve 20. When the operating stem 28 is further slid by rotating the throttle lever 16, The flange portion 29 engages with the lower end portion 20b of the sleeve valve 20 to cause the sleeve valve 20 to slide upward, thereby causing the O-ring 22 to deviate from the annular flange portion 21 and the opening 18 of the valve housing 17. The openings 19 are communicated with each other.

  Sand or dust that enters the valve housing 17 from the supply passage 12 through the opening 18 is formed at the upper end of the valve housing 17 that is disposed in the supply passage 12. A dust-proof filter 30 is attached to catch dust such as. The dust filter 30 is formed by forming a cylindrical filter material obtained by molding a fine metal wire into a wire mesh. The dust filter 30 is formed in a portion of the valve housing 17 where the opening 18 is formed. The valve housing 17 is attached to the impact driver 1 so as to be mounted on the outer periphery and so that the dustproof filter 30 faces the supply passage 12. A recess 12 a is formed in the supply passage 12 so that a space is formed around the dust filter 30. The compressed air in the supply passage 12 is transmitted from the entire periphery of the dust filter 30 to the opening 18 side. I can do it.

  Hereinafter, the operating state of the throttle valve 15 according to the embodiment will be described. When the throttle lever 16 is not operated to rotate, as shown in FIG. 2, the compressed air that has passed through the dust filter 30 and entered the valve housing 17 through the opening 18 is attached to the sleeve valve 20. The O-ring 22 is fitted in an annular flange 21 formed in the valve housing 17 so that the supply to the air motor 4 is interrupted. Further, the compressed air that has entered the sleeve valve 20 through the opening 24 is also fitted in the inner part of the air passage 25 in which the ball valve 27 is formed in a tapered shape, and the air passage 25 is closed. Supply to the air motor 4 side is shut off.

  When the throttle lever 16 is rotated by the hand holding the grip portion 3 to slide the operation stem 28, the operation stem 28 is slid upward as shown in FIG. The ball valve 27 is moved away from the inner part of the tapered air passage 25 against the urging force of the spring 26 by the tip of the tip, thereby opening the air passage 25. As a result, the compressed air in the supply passage 12 that has flowed into the hollow of the sleeve valve 20 through the opening 24 passes through the air passage 25, and the opening 20 a formed in the peripheral wall of the sleeve valve 20 and the valve housing 17. The air motor 4 is rotationally driven by being supplied to the air motor 4 through the opening 19 and the communication path 14 formed in the above.

  At this time, the moving position of the ball valve 27 with respect to the tapered air passage 25 via the operation stem 28 can be arbitrarily adjusted by adjusting the amount of rotation operation of the throttle lever 16. The air flow area formed between the inner peripheral surface of the air passage 25 formed in a taper shape and the outer peripheral surface of the ball valve 27 is variably adjusted by adjusting the amount of air supplied to the air motor 4 to rotate the air motor 4. The number can be appropriately adjusted according to the amount of rotation of the throttle lever 16.

  When the throttle lever 16 is further rotated, as shown in FIG. 6, the operating stem 28 is further slid upward to form a flange portion 29 formed on the outer periphery of the operating stem 28. The sleeve valve 20 is moved upward by engaging with 20b. By sliding the sleeve valve 20 in this way, the O-ring 22 deviates from the annular flange 21 formed in the valve housing 17 so that the opening 18 side and the opening 19 side of the valve housing 17 communicate with each other. Then, the compressed air supplied through the dust filter 30 and supplied into the valve housing 17 through the opening 18 is caused to flow along the outer peripheral surface of the sleeve valve 20, and this compressed air is passed through the opening 19. Thus, the air motor 4 is rotated and driven. As described above, since the O-ring 27 attached to the sleeve valve 20 deviates from the annular annular flange 21 formed in the valve housing 17, a large flow path cross section is formed. The air motor 4 can be driven at a high output.

  As described above, according to the impact driver 1 of the present embodiment, an opening is formed in the peripheral wall of the hollow valve housing 17, and a dustproof filter 30 formed in a cylindrical shape is attached to the outer periphery of the valve housing 17. Since the compressed air passes through the cylindrical dustproof filter 30 and is introduced into the hollow of the valve housing 17, the dustproof filter 30 allows the supply passage 12 formed in the grip portion 3 to have a small diameter. The flow resistance is not increased, and sufficient compressed air can be continuously supplied to the air motor 4 so that the performance of the tool is not deteriorated. Further, since it is not necessary to increase the diameter of the supply passage 12 formed in the grip portion 3, it is not necessary to increase the outer shape of the grip portion 3, and it is formed in a grip shape that is easy to grip according to the shape of the tool. This makes it possible to work without impairing workability.

  In addition, in the conventional plate-shaped dustproof filter, it was necessary to fix and attach the outer peripheral edge of the dustproof filter so that the filter material would not bend and come off due to the pressure of compressed air. By using the formed dustproof filter 30, the dustproof filter 30 can be mounted simply by fitting it into the outer circumference or inner circumference of the cylindrical valve housing 17. The number of steps for assembling the dustproof filter 30 and parts for fixing the dustproof filter It is possible to reduce the number of processing steps.

  Furthermore, when a larger compressed air circulation area than the above embodiment is required, the cylindrical portion of the valve housing 17 of the throttle valve 15 is formed longer in the axial direction to increase the number of openings 18, Alternatively, the entire opening area of the opening 18 can be made large by making the shape of the opening 18 a long hole formed long in the axial direction of the valve housing 17. By forming a large effective area in this way, it is possible to prevent the performance of compressed air tools that require a larger flow rate from being deteriorated, and even if the dustproof filter mesh is further refined to improve the dustproof performance, compression is possible. The performance of the pneumatic tool is not deteriorated.

1 is a longitudinal side view of an impact driver according to an embodiment of the present invention. Detailed sectional view of the throttle valve in the impact driver of FIG. Sectional view on the AA line in FIG. The perspective view which shows the valve housing and dustproof filter of the same throttle valve as FIG. Sectional view similar to FIG. 3 of the throttle valve showing the operating state with the ball valve opened Sectional view similar to FIG. 3 of the throttle valve showing the operating state in which the sleeve valve is operated

Explanation of symbols

1 Impact driver (compressed air tool)
2 Housing 3 Grip part 12 Supply passage 15 Throttle valve 16 Throttle lever 17 Valve housing 18 Opening 19 Opening 30 Dustproof filter

Claims (1)

In a compressed air tool comprising an air motor that is rotationally driven by compressed air, and supplying the compressed air supplied from a compressed air supply source to the air motor via a throttle valve so that the air motor is rotationally driven. An opening for communicating the inside and outside of the valve housing is formed in the outer peripheral wall of the hollow valve housing forming the throttle valve, and the outer peripheral surface or the inner peripheral surface of the valve housing in which the opening is formed is cylindrical. A dustproof filter formed on the valve housing is mounted, and the portion of the valve housing where the dustproof filter is mounted faces the supply passage to which compressed air is supplied from the compressed air supply source, and is supplied into the supply passage. Compressed air is introduced into the inside of the valve housing through the dust filter and the opening. Dust filter device for compressed air tools, characterized in that it has to supply to the over data.

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