JP6897741B2 - Pneumatic tool - Google Patents

Description

The present invention relates to a pneumatic tool that strikes or rotates a stopper using compressed air as a power source.

Pneumatic tools or gas-type tools that use compressed air or combustion gas as a power source to strike a stopper are known. In such a pneumatic tool, it is common to lubricate the inside of the tool in order to maintain good lubrication inside the tool. The lubricated lubricating oil goes around the inside of the tool together with the compressed air, and then mixes with dirt and moisture adhering inside the tool to form a drain (for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2009-160665

However, the pneumatic tool described in Patent Document 1 has a problem that the drain is discharged to the outside of the tool from the exhaust port together with the compressed air, and the discharged drain scatters and pollutes the surroundings. Then, the discharged drain may be applied to the worker or adhere to the surrounding work members. Therefore, an object of the present invention is to provide a pneumatic tool capable of realizing high efficiency, high workability and environmental friendliness.

A brief description of typical inventions disclosed in the present application is as follows.

In one embodiment of the present invention, a housing having a compressed air intake port, a compressed air exhaust port, and a grip portion, and a stopper that is supported by the housing and is operated by compressed air flowing in from the compressed air intake port. Provided between the actuating portion and the actuating portion for rotating the stopper, a control unit for controlling the inflow of compressed air from the compressed air intake port to the actuating portion, and the actuating portion and the compressed air exhaust port. An exhaust passage through which the compressed air discharged from the operating portion passes, and a tubular partition wall having one end arranged in the exhaust passage and forming an air passage inside which communicates with the compressed air exhaust port. The outer wall of the tubular partition wall is separated from the inner wall of the exhaust passage, and a space is formed between the outer wall of the tubular partition wall and the inner wall of the exhaust passage . through the inner and the compressed air outlet of the cylindrical partition wall is capable discharged outside of the housing, and, drainable der Ru pneumatic tool to the outside of the housing through the space.

According to the pneumatic tool of the present invention, high efficiency, high workability and environmental friendliness can be realized. Further, the drain can be separated without interfering with the exhaust of the compressed air and without reducing the efficiency.

Sectional drawing of the pneumatic tool which concerns on 1st Embodiment of this invention. The enlarged view of the main part which shows the periphery of the handle of the pneumatic tool which concerns on 1st Embodiment of this invention. The enlarged view which shows the periphery of the operating part of the pneumatic tool which concerns on 1st Embodiment of this invention. It is operation explanatory drawing of the pneumatic tool which concerns on 1st Embodiment of this invention, and is the figure which shows the initial state. It is operation explanatory drawing of the pneumatic tool which concerns on 1st Embodiment of this invention, and is the figure which shows the state which operated the push lever and the trigger. It is operation explanatory drawing of the pneumatic tool which concerns on 1st Embodiment of this invention, and is the figure which shows the state which the movement of the main piston has started. It is operation explanatory drawing of the pneumatic tool which concerns on 1st Embodiment of this invention, and is the figure which shows the state which the rotation of an air motor has started. It is operation explanatory drawing of the pneumatic tool which concerns on 1st Embodiment of this invention, and is the figure which shows the state which the sub-piston descends while rotating. It is operation explanatory drawing of the pneumatic tool which concerns on 1st Embodiment of this invention, and is the figure which shows the state which the screw tightening operation is completed. It is an operation explanatory view of the pneumatic tool which concerns on 1st Embodiment of this invention, and is the figure which shows the state which turned off the trigger in the state which the piston is located at the bottom dead center. It is operation explanatory drawing of the pneumatic tool which concerns on 1st Embodiment of this invention, and is the figure which shows the state which the main piston and the sub-piston are pulled up. An enlarged view of a main part showing a periphery of a handle of a pneumatic tool according to a second embodiment of the present invention. An enlarged view of a main part showing a periphery of a handle of a pneumatic tool according to a third embodiment of the present invention. The enlarged view of the main part which shows the periphery of the handle of the modification of the pneumatic tool which concerns on 1st Embodiment of this invention. The enlarged view of the main part which shows the periphery of the handle of another modification of the pneumatic tool which concerns on 1st Embodiment of this invention. FIG. 3 is a cross-sectional view of a pneumatic tool according to a fourth embodiment of the present invention. A side view of the filter mechanism used in the pneumatic tool according to the fourth embodiment of the present invention, a cross-sectional view of (b) and (a) along the line bb, and (c) the inside of the exhaust pipe. A cross-sectional view showing the flow of compressed air when placed in. The side view of the support member used for the pneumatic tool which concerns on 4th Embodiment of this invention. The perspective view which shows the rear end part of the pneumatic tool which concerns on 4th Embodiment of this invention. FIG. 3 is a perspective view of a filter mechanism of a first modification of the pneumatic tool according to the fourth embodiment of the present invention. FIG. 3 is a cross-sectional view of the rear end of a second modification of the pneumatic tool according to the fourth embodiment of the present invention. FIG. 5 is a cross-sectional view of a pneumatic tool according to a modification common to the first and fourth embodiments of the present invention.

<First Embodiment>
Hereinafter, the pneumatic tool according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 11. The pneumatic tool 1 shown in FIG. 1 is a tool having a housing 2 as an outer shell and operated by compressed air to fasten a screw 1B (FIG. 3) which is a stopper at a bit portion 1A. The pneumatic tool 1 has a housing 2, an operating portion 3, a nose portion 9, and a magazine 10. The bit portion 1A is formed in a long columnar shape having a bit screwed with the screw 1B at the tip.

The housing 2 has an actuating portion housing 21 and a handle 22 for accommodating the actuating portion 3. The nose portion 9 described above is attached to one end side of the operating portion housing 21. The vertical direction is defined with the direction from the operating portion housing 21 toward the nose portion 9 as the downward direction.

The handle 22 extends in a direction intersecting the vertical direction from a substantially intermediate position in the vertical direction of the operating portion housing 21. The handle 22 has a grip portion 22A gripped by an operator and a rear end portion 22B located at an end on the reaction-actuating portion housing 21 side. The front-rear direction is defined with the operating portion housing 21 side as the front side and the rear end portion 22B side as the rear side. The rear end portion 22B is provided with a connecting portion 22C having a compressed air intake port 22a. A pressure reducing valve 23 is provided in the connecting portion 22C, and a compressed air exhaust port 22b is formed above the pressure reducing valve 23 in the rear end portion 22B. The compressed air intake port 22a is also used as a lubricating oil supply port (not shown).

Further, in the handle 22, an exhaust pipe 24 extending from the grip portion 22A toward the rear end portion 22B and communicating the exhaust chamber 21e and the compressed air exhaust port 22b, which will be described later, is provided. That is, the exhaust pipe 24 is provided between the operating portion 3 and the compressed air exhaust port 22b. The exhaust pipe 24 has a pressure accumulator chamber 22c on the outside and an exhaust passage 22d on the inside to partition the space inside the handle 22 (grip portion 22A). That is, at least a part of the accumulator chamber 22c and the exhaust pipe 24 is provided in the grip portion 22A, and the exhaust passage 22d is defined adjacent to the accumulator chamber 22c. That is, the accumulator chamber 22c is located between the compressed air suction port 22a and the operating portion 3, and is defined so as to be adjacent to the exhaust pipe 24. The pressure accumulator chamber 22c is connected to the compressed air intake port 22a via the pressure reducing valve 23, and the air flowing in from the compressed air intake port 22a can be stored inside. Specifically, when the connecting portion 22C is connected to a compressed air supply source (not shown) such as a compressor, the compressed air flowing in from the compressed air intake port 22a is decompressed by the pressure reducing valve 23 and then taken into the accumulator chamber 22c. And stored.

The exhaust pipe 24 corresponds to a tubular casing, and has an inflow portion 24A into which compressed air flows, a throttle portion 24B that communicates with the inflow portion 24A and has an inner shape smaller than the inner diameter of the inflow portion 24A, and a throttle portion 24B. It has a large diameter portion 24C having an inner diameter larger than the inner diameter of the throttle portion 24B, and a circulation path 24D that communicates the space inside the throttle portion 24B with the drain chamber 22e described later. The inflow portion 24A communicates with the exhaust chamber 21e described later. The compressed air that has passed through the operating portion 3 expands when passing through the large diameter portion 24C, and the flow velocity decreases. The large diameter portion 24C corresponds to an expansion chamber. In the circulation path 24D, the drain chamber 22e and the throttle portion 24B are connected by a communication hole 24I, so that the air pressure in the drain chamber 22e is changed in the large diameter portion 24C by the negative pressure of the compressed air passing through the throttle portion 24B at high speed. Make it lower than the atmospheric pressure and circulate it.

As shown in FIG. 2A, a drain separator 24E that separates the drain from the compressed air that has passed through the operating portion 3 is provided in the large diameter portion 24C. Specifically, the large diameter portion 24C has a stepped portion 24F, and the drain separator 24E is fitted and fixed to the stepped portion 24F. The exhaust pipe 24 and the drain separator 24E correspond to the separation means.

The drain separator 24E includes a disk-shaped base portion 24G having a plurality of through holes (not shown), and a plurality of blade portions (fin structures) 24H protruding diagonally rearward from the base portion 24G toward the radial outer side of the exhaust pipe 24. Has. The drain separator 24E is obtained by bending a single metal disk, and a plurality of through holes (not shown) are formed radially at intervals of 60 °. Specifically, as shown in FIG. 2B, the disk material is not cut at the portion indicated by the broken line, but only the portion indicated by the solid line is cut and bent at the portion indicated by the broken line. A base portion 24G, a through hole (not shown), and a substantially fan-shaped plate-shaped blade portion 24H are formed. The blade portion 24H guides the compressed air that has passed through the through hole (not shown) in the circumferential direction and the radial direction outside, that is, in the centrifugal direction. When the compressed air passes, it collides with the blade portion 24H, so that the compressed air and the drain are separated by the passing resistance and the centrifugal force. The blade portion 24H can be rephrased as a baffle plate. Further, in the blade portion 24H, the compressed air after the drain separation flows in the circumferential direction along the blade portion 24H, and the separated drain flows along the blade portion 24H to the side wall of the large diameter portion 24C and adheres to the blade portion 24H. It is configured.

Further, the rear end portion 22B of the handle 22 has a tubular partition wall 22D protruding from the compressed air exhaust port 22b toward the drain separator 24E. The partition wall 22D is provided so as to project so that the front end portion is located in the large diameter portion 24C. With such an arrangement, the rear end portion 22B and the exhaust pipe 24 define the drain chamber 22e, the flow path 22f, and the air passage 22g. The drain chamber 22e corresponds to a storage portion and is a space for storing the drain separated by the drain separator 24E. The drain chamber 22e is provided in the handle 22 and is located closer to the compressed air exhaust port 22b than the operating portion 3. Specifically, it is a portion outside the partition wall 22D and not facing the exhaust pipe 24, and is defined between the grip portion 22A and the compressed air exhaust port 22b. The flow path 22f is defined between the rear end portion of the exhaust pipe 24 and the front end portion of the partition wall 22D facing the rear end portion of the exhaust pipe 24. The air passage 22g is a space inside the partition wall 22D and communicates between the exhaust pipe 24 and the compressed air exhaust port 22b. The air passage 22g is a part of the exhaust passage 22d. As described above, the partition wall 22D partitions the air passage 22g and the drain chamber 22e.

Further, an expansion space 22h is defined between the compressed air exhaust port 22b and the air passage 22g. That is, the expansion space 22h is defined between the compressed air exhaust port 22b and the exhaust pipe 24. The expansion space 22h has a cross-sectional area larger than the cross-sectional area of the air passage 22g, and is an expansion chamber that expands the air flowing in from the air passage 22g. A sound absorbing material is inserted into the expansion space 22h to form a muffler 22E that reduces exhaust noise.

With the above configuration, the compressed air that has passed through the drain separator 24E flows in the air passage 22g, passes through the muffler 22E, and is then exhausted into the atmosphere from the compressed air exhaust port 22b. On the other hand, the drain separated by the drain separator 24E adheres to the side wall of the large diameter portion 24C from the blade portion 24H, passes through the side wall of the large diameter portion 24C, passes through the flow path 22f, and is stored in the drain chamber 22e. Since the drain chamber 22e is connected to the throttle portion 24B via the circulation path 24D and the communication hole 24I, the air pressure in the drain chamber 22e is set to be lower than the air pressure in the large diameter portion 24C. .. As a result, the drain separated from the compressed air by the drain separator 24E can be drawn into the drain chamber 22e and stored.

Further, a drain discharge hole 22j that communicates the outside of the housing 2 with the drain chamber 22e is formed in the upper portion of the handle 22 that serves as the side wall of the drain chamber 22e. The drain discharge hole 22j is sealed with a transparent drain bolt 24J. Since the drain bolt 24J is transparent, the storage state of the drain can be easily confirmed from the outside, and the drain bolt 24J can be arbitrarily removed to drain the drain. The drain bolt 24J may be a toolless (hand-cranked) bolt that can be removed. Further, as another embodiment, when the drain leakage is practically sufficiently small, the drain can be discharged to the outside in a state where the pneumatic tool 1 is not driven and the pneumatic tool 1 is turned upside down. When driving the pneumatic tool 1, only holes formed with a small diameter so that drain does not leak due to surface tension may be configured.

As shown in FIG. 3, an operation valve 25 and a trigger 26 are provided at a position around the base of the handle 22 in the operating portion housing 21, and a first air passage 21b communicating with and connected to the operation valve 25. A groove 21a is formed in which the sleeve valve 43 described later is incorporated so as to be movable up and down. The operation valve 25 controls the communication between the first air passage 21b and the outside air, and in a state where the operation valve 25 is not operating, the first air passage 21b and the outside air are shut off, and the first air passage 25 is used. 21b and the accumulator chamber 22c communicate with each other. With the operation valve 25 in operation, the first air passage 21b and the outside air are communicated with each other, and the first passage 21b and the accumulator chamber 22c are shut off. The trigger 26 is configured to be able to operate the operation valve 25 in cooperation with the push lever 91 (FIG. 1) described later, and is an example of a control unit.

The groove 21a is formed around the spindle 41, which will be described later, at a substantially intermediate position in the vertical direction of the spindle 41, communicates with the first air passage 21b on the lower side of the groove 21a, and shuts off on the upper side.

Further, in the operating portion housing 21, a second air passage 21c communicating with the upper portion of the groove 21a and the accumulator chamber 22c, and a third air passage 21d communicating with the inside of the cylinder 51 described later and the air motor 31 described later (FIG. 4), an exhaust chamber 21e communicating with the air motor 31 and the exhaust passage 22d, and a fourth air passage 21f located near the first air passage 21b and communicating with the groove 21a and the exhaust passage 22d are defined.

The actuating portion 3 is supported in the actuating portion housing 21. The operating unit 3 is a mechanism that operates by the compressed air flowing in from the compressed air intake port 22a to hit the screw 1B or rotate the screw 1B, and is a mechanism that includes an air motor 31, a planetary gear mechanism 32, and a rotating body 4. And a cylinder portion 5. The air motor 31 is a known device that is rotatably supported at the uppermost position in the operating portion housing 21 with the vertical direction as the output shaft direction and is rotated by compressed air. The air motor 31 communicates with the cylinder chamber 5a described later via the third air passage 21d (FIG. 4) and also communicates with the exhaust passage 22d via the exhaust chamber 21e.

The planetary gear mechanism 32 has a configuration in which a spindle 41 described later is used as a planetary carrier, and includes a sun gear 32A that rotates coaxially with the output shaft of the air motor 31, a plurality of revolution gears 32B that mesh with the sun gear 32A, and an operating unit. It has a ring gear 32C that is fixed to the housing 21 and meshes with the revolution gear 32B. The revolution gear 32B is rotatably mounted on the upper part of the spindle 41 described later.

The rotating body 4 and the cylinder portion 5 will be described. The rotating body 4 includes a spindle 41, a slider 42, a sub-piston portion 6, and a main piston portion 7. The spindle 41 is a cylinder whose upper end is closed and whose lower end is open, and is rotatably held by the operating portion housing 21, and a plurality of revolving gears 32B are rotatably held above the spindle 41. With such a configuration, the spindle 41 acts as a planetary carrier of the planetary gear mechanism 32, and the rotation of the air motor 31 is decelerated and transmitted to the spindle 41.

A cylinder intake hole 41a and a cylinder exhaust hole 41b are formed on the side wall of the spindle 41, and the cylinder intake hole 41a and the cylinder exhaust hole 41b are formed at positions that allow communication with the groove 21a. A cylindrical sleeve valve 43 that can move up and down is urged upward by a spring 44 in the groove 21a of the operating portion housing 21. The sleeve valve 43 has a main valve vent hole 43a, and the upper end and lower end side surfaces are sealed. When the sleeve valve 43 is located on the upper end side of the groove 21a, the sleeve valve 43 closes the cylinder intake hole 41a and the spindle so that compressed air does not flow into the spindle 41 from the gap between the sleeve valve 43 and the operating portion housing 21. The inside of 41 and the exhaust passage 22d communicate with each other. On the other hand, when the sleeve valve 43 is located on the lower end side of the groove 21a (FIG. 5), the cylinder intake hole 41a and the accumulator chamber 22c communicate with each other via the second air passage 21c, and the inside of the spindle 41 and the exhaust gas. The passage 22d is blocked.

When the push lever 91 and the trigger 26 are not operated, the upper part of the groove 21a communicates with the accumulator chamber 22c via the second air passage 21c, and the lower part of the groove 21a passes through the first air passage 21b and the operation valve 25. It communicates with the accumulator chamber 22c. Therefore, the first air passage 21b and the second air passage 21c are filled with compressed air. Therefore, the sleeve valve 43 is urged upward by the compressed air from the spring 44 and the accumulator chamber 22c, and is pushed up by the compressed air in the first air passage 21b to the upper end side in the groove 21a. It is located and blocks the communication between the cylinder intake hole 41a and the accumulator chamber 22c.

Further, a pair of recesses 41C extending in the vertical direction are formed on the inner surface of the spindle 41.

The slider 42 is arranged in the spindle 41, has a convex portion 42A that engages with the concave portion 41C, and is configured to be non-rotatable and vertically movable with respect to the spindle 41. Further, at the lower end position of the convex portion 42A in the slider 42, an air blocking surface 42B that comes into surface contact with the plate portion 52 described later and blocks the vertical space of the slider 42 is defined.

The cylinder portion 5 has a cylinder chamber 5a defined inside, and is mainly composed of a cylinder 51, a plate portion 52, and a piston bumper 53. The cylinder 51 has a tubular shape, is arranged below the spindle 41 in the operating portion housing 21, and is fixed to the operating portion housing 21. A return air chamber 5b is defined outside the cylinder 51 and between the operating portion housing 21. A check valve 54 is provided at a lower position of the cylinder 51 to allow the outflow of compressed air from the cylinder 51 to the return air chamber 5b and to block the outflow of compressed air from the return air chamber 5b to the cylinder space 5a. The compressed air outflow hole 51a is formed. In the cylinder 51, below the compressed air outflow hole 51a, a compressed air inflow hole 51b that allows the inflow of compressed air from the return air chamber 5b into the cylinder 51 is formed.

The plate portion 52 is located between the cylinder 51 and the spindle 41, and cooperates with the cylinder 51 to define a cylinder chamber 5a in which the main piston portion 7 is housed. The plate portion 52 is formed with a ventilation hole 52a that communicates with the cylinder chamber 5a and the third air passage 21d (FIG. 4). Therefore, the compressed air that has flowed into the cylinder chamber 5a is supplied from the ventilation hole 52a to the air motor 31 via the third air passage 21d. Further, the upper surface of the plate portion 52 is configured to be flat so as to be in surface contact with the air blocking surface 42B. Therefore, when the slider 42 moves to the bottom dead center side and the air blocking surface 42B is in contact with the plate portion 52, the slider 42 and the plate portion 52 are in close contact with each other, and the slider 42 and the plate portion 52 are brought into close contact with each other. The inflow of compressed air into the cylinder chamber 5a is suppressed from between.

The piston bumper 53 is an elastic body such as rubber, and is arranged at the lower end position of the cylinder 51 in the cylinder chamber 5a. The piston bumper 53 is formed with a through hole 53a having a through direction in the vertical direction, and an O-ring 53A is arranged in the through hole 53a. When an impact is applied to the piston bumper 53 from above, the impact can be buffered by the elasticity of the piston bumper 53.

As shown in FIG. 3, the sub-piston portion 6 is configured by integrally molding the shaft 61, the driver bit mounting portion 62, the sub-piston 63, and the collar portion 64.

The shaft 61 is located at the upper end of the sub-piston portion 6, is formed in a long cylindrical shape extending in the vertical direction, and is mounted on the slider 42. On the upper end side of the shaft 61, an air supply hole 61a that opens in the spindle 41 at the upper part of the slider 42 is formed, and on the lower side, an air supply hole 61a that opens in the upper hollow space 71a described later and communicates with the air supply hole 61a. The air discharge hole 61b is formed.

The driver bit mounting portion 62 is located at the lower end of the sub-piston portion 6, so that the bit portion 1A can be mounted and the outer diameter orthogonal to the vertical direction is such that the diameter can be fitted to the O-ring 53A. It is configured.

The sub-piston 63 is located below the shaft 61 and is integrally formed with the shaft 61 so that the outer diameter is larger than that of the shaft 61. An O-ring 63A is mounted on the outer circumference of the sub-piston 63.

The flange portion 64 is located between the sub-piston 63 and the driver bit mounting portion 62, and is configured to have a diameter smaller than the outer diameter of the sub-piston 63 and a diameter larger than the outer diameter of the driver bit mounting portion 62. Has been done. The flange portion 64 is configured to come into contact with the upper surface of the piston bumper 53 when the driver bit mounting portion 62 is inserted into the through hole 53a of the piston bumper 53.

The main piston portion 7 is mainly composed of the main piston 71. The main piston 71 has a cylindrical shape whose outer diameter is smaller than the inner diameter of the cylinder chamber 5a, and is arranged in the cylinder chamber 5a with the sub-piston portion 6 incorporated therein. Inside the main piston 71, which has a tubular shape, an upper hollow space 71a and a lower hollow space 71b are formed so as to communicate with each other vertically. The upper hollow space 71a is formed so that the inner diameter thereof is slightly larger than the outer diameter of the shaft 61 and smaller than the outer diameter of the sub-piston 63, and the O-ring 72 fills the gap between the upper hollow space 71a and the shaft 61. It is installed. The lower hollow space 71b is configured such that the inner diameter thereof is slightly larger than the outer diameter of the sub-piston 63, and the O-ring 63A is configured to be slidable in contact with the wall surface in the lower hollow space 71b. ing. Since the inner diameter of the lower hollow space 71b is larger than the inner diameter of the upper hollow space 71a as described above, the upper hollow space 71a and the lower hollow space 71b are located at the boundary position between the upper hollow space 71a and the lower hollow space 71b. Step 71A is defined.

The main piston 71 is formed with a communication hole 71c that opens in the lower hollow space 71b and opens on the outer periphery of the main piston 71 at a position near the step 71A. Further, O-rings 73 and 74 are mounted on the outer peripheral surface of the main piston 71, respectively. As shown in FIG. 9, the O-ring 73 is between the compressed air outflow hole 51a and the compressed air inflow hole 51b in a state where the main piston 71 has moved to the bottom dead center position, that is, in a state where it is in contact with the piston bumper 53. It is arranged so that it is located in. The O-ring 74 is formed above the communication hole 71c.

As shown in FIG. 1, the nose portion 9 is located below the operating portion housing 21, and the injection passage 9a through which the bit portion 1A passes and the screw 1B (FIG. 4) is supplied from the magazine 10 and the nose portion. An injection hole 9b located at the lower end of the 9 and into which a screw is punched out is formed. Further, the nose portion 9 is provided with a push lever 91 and a screw feed portion 92. The push lever 91 is provided so as to be vertically movable in the vicinity of the injection hole 91b, and is interlocked with the operation valve 25. The screw feed unit 92 supplies a screw (not shown) supplied from the magazine 10 to the injection passage 9a.

The magazine 10 is attached to the nose portion 9, and is built in a state in which a plurality of screws 1B (FIG. 4) are connected by a connecting band (not shown).

The operation of the pneumatic tool 1 configured as described above will be described with reference to FIGS. 4 to 11. In FIGS. 4 to 11, the flow of compressed air is indicated by arrows. Further, in order to properly explain the operation, a part of the reference numerals given in FIGS. 1 to 3 is omitted, and the third air passage 21d is conceptually shown by a chain double-dashed line.

First, when the connecting portion 22C is connected to a compressor (not shown), the compressed air flows into the accumulator chamber 22c and the operating valve 25 via the compressed air intake port 22a and the pressure reducing valve 23. Further, the compressed air also flows into the second air passage 21c communicating with the accumulator chamber 22c and the first air passage 21b communicating with the operation valve 25. As a result, the sleeve valve 43 is pressed from the upper side by the compressed air in the second air passage 21c, and is also pressed from the lower side by the compressed air in the first air passage 21b and the urging force of the spring 44. As shown, it is held at a position on the upper end side in the groove 21a. At this time, the sleeve valve 43 is located on the upper end side of the groove 21a and shuts off the cylinder intake hole 41a and the second air passage 21c.

When the push lever 91 is pressed against the surface 1C of the material to be fastened to operate the trigger 26 from the initial state shown in FIG. 4, the operation valve 25 is activated and the pneumatic tool 1 is started to be driven. When the push lever 91 is pressed against the surface 1C of the material to be fastened while pulling the trigger 26, the operation valve 25 operates in the same manner, and the driving of the pneumatic tool 1 is started. When the operation valve 25 is operated, the first air passage 21b communicates with the outside air via the operation valve 25, and the pressure on the lower end side of the sleeve valve 43 becomes lower than the pressure on the upper end side of the sleeve valve 43. Due to this pressure difference, the sleeve valve 43 moves to the lower end side of the groove 21a against the urging force of the spring 44. As the sleeve valve 43 moves to the lower end side of the groove 21a, as shown in FIG. 5, the cylinder intake hole 41a communicates with the accumulator chamber 22c via the second air passage 21c, and the accumulator chamber 22c is contained in the spindle 41. The compressed air inside flows in.

When the compressed air flows into the spindle 41, as shown in FIG. 6, air pressure is applied to the upper surface of the main piston 71, and the main piston portion 7 is pushed down to start descending. After that, the air pressure of the compressed air that has passed through the air supply hole 61a and the air discharge hole 61b and the compressed air that has passed through the communication hole 71c is applied to the upper surface of the sub-piston 63, and the sub-piston portion 6 is also pushed downward.

As shown in FIG. 7, when the main piston portion 7 descends by a predetermined distance and the O-ring 74 passes through the ventilation hole 52a, the inside of the spindle 41 and the cylinder chamber 5a and the ventilation hole 52a communicate with each other and flow in from the inside of the spindle 41. A part of the compressed air is supplied to the air motor 31 through the third air passage 21d. Since the air motor 31 is also communicated with the exhaust passage 22d, the air motor 31 can be rotationally driven by the compressed air by discharging the compressed air into the atmosphere through the exhaust passage 22d. Then, the compressed air that has passed through the air motor 31 flows through the exhaust chamber 21e and the exhaust passage 22d, and is separated into drain and compressed air through the drain separator 24E of the exhaust pipe 24. The compressed air after drain separation flows in the air passage 22g, passes through the muffler 22E, and is exhausted to the atmosphere from the compressed air exhaust port 22b. On the other hand, the separated drain passes through the side wall of the large diameter portion 24C, passes through the flow path 22f, and is stored in the drain chamber 22e. Since the drain chamber 22e is connected to the throttle portion 24B via the circulation path 24D and the communication hole 24I, the air pressure in the drain chamber 22e is lower than the air pressure in the large diameter portion 24C. As a result, the drain separated by the drain separator 24E can be drawn into the drain chamber 22e.

The rotation of the air motor 31 is transmitted to the spindle 41 via the planetary gear mechanism 32. As the spindle 41 rotates, the slider 42 rotates together with the spindle 41 via the convex portion 42A fitted in the concave portion 41C. Further, the shaft 61 and the bit portion 1A also rotate integrally with the spindle 41. As a result, the sub-piston portion 6 and the bit portion 1A descend while rotating integrally to tighten the screw 1B to the fastening member.

As the sub-piston portion 6 rotates and further descends, and as shown in FIG. 8, when the O-ring 73 passes through the compressed air outflow hole 51a just before the main piston 71 reaches the bottom dead point, the air supply hole 61a A part of the compressed air in the cylinder chamber 5a is supplied to the return air chamber 5b from the compressed air outflow hole 51a via the air discharge hole 61b and the communication hole 71c.

When the main piston 71 reaches the bottom dead center and stops, as shown in FIG. 9, the sub-piston portion 6 descends while sliding in the main piston 71. Therefore, the bit portion 1A is lowered by the thrust force of only the sub-piston portion 6, and the screw 1B is tightened to the material to be fastened. At this time, the return air chamber 5b and the inside of the lower hollow space 71b located in the lower part of the sub-piston 63 are blocked by the contact between the bottom surface of the main piston 71 and the piston bumper 53 and the check valve 54. Therefore, the compressed air in the return air chamber 5b does not flow into the lower part of the sub-piston 63.

After that, when the screw 1B is tightened to a predetermined depth, the air blocking surface 42B of the slider 42 abuts against the plate portion 52 and comes into close contact with the plate portion 52, thereby stopping the lowering of the slider 42 and communicating the inside of the spindle 41 with the cylinder chamber 5a. The compressed air supply to the ventilation hole 52a is stopped, and at about the same time, the flange portion 64 comes into contact with the piston bumper 53, the rotation of the air motor 31 is stopped, and the screw tightening is completed.

After the screw tightening is completed, when the push lever 91 is separated from the surface 1C of the member to be fastened or the trigger 26 is turned off, the operation valve 25 returns to the initial position. That is, when at least one of the push lever 91 and the trigger 26 is returned to the initial state, the operation valve 25 returns to the initial position. Therefore, after the screw tightening is completed, the push lever 91 may be separated after the trigger 26 is turned off, or the push lever 91 may be separated after the trigger 26 is turned off.

As shown in FIG. 10, when the operation valve 25 returns to the initial position, compressed air flows into the first air passage 21b, and the sleeve valve 43 is pushed up toward the upper end side of the groove 21a. When the sleeve valve 43 is pushed up to the upper end side, the main valve ventilation hole 43a of the sleeve valve 43 and the cylinder exhaust hole 41b communicate with each other, and the space inside the spindle 41 passes through the fourth air passage 21f and the exhaust chamber 21e. Communicate with 22d. As a result, the compressed air in the spindle 41 and in the cylinder chamber 5a is discharged to the exhaust passage 22d. Specifically, the compressed air discharged from the inside of the spindle 41 flows through the exhaust chamber 21e and the exhaust passage 22d in the same manner as the compressed air discharged from the air motor 31, and drains and the compressed air by the drain separator 24E of the exhaust pipe 24. Is separated into. The compressed air after drain separation flows in the air passage 22g, passes through the muffler 22E, and is exhausted to the atmosphere from the compressed air exhaust port 22b. On the other hand, the separated drain passes through the side wall of the large diameter portion 24C, passes through the flow path 22f, and is stored in the drain chamber 22e.

When the compressed air is exhausted from the inside of the spindle 41 and the cylinder chamber 5a and the internal pressure drops, the main piston portion 7 is pulled up and the compressed air in the return air chamber 5b is discharged into the compressed air inflow hole as shown in FIG. It flows into the lower part of the main piston 71 through 51b. The compressed air flowing in from the return air chamber 5b further pushes up the main piston 71 and returns it to the initial position. At the same time, as the main piston 71 moves, the air is not shut off by the main piston 71 and the piston bumper 53, and the compressed air in the return air chamber 5b also flows into the lower part of the sub-piston 63. The main piston portion 7 and the bit portion 1A are pushed up to return to the initial position (FIG. 4). Further, of the compressed air stored in the return air chamber 5b, the excess air after the main piston portion 7 and the sub-piston portion 6 are pushed up is exhausted to the outside through the through hole 53a of the piston bumper 53. At the same time, the screw feed unit 92 sends the next screw (not shown) to the injection passage 9a to return to the initial state.

According to the above pneumatic tool 1, the drain generated by mixing the lubricating oil with dirt and moisture can be separated from the compressed air and stored in the drain 22e. That is, it is possible to prevent the drain from being discharged to the outside from the compressed air exhaust port 22b together with the exhaust of the compressed air and scattered to the surroundings. Therefore, it is possible to prevent the operator from being drained, and to simplify the protection of the member at the work site where a member made of a material that dislikes dirt such as gypsum board is used. Therefore, it is possible to provide a pneumatic tool with high efficiency, high workability and high environmental friendliness.

Further, since the exhaust pipe 24 has a large diameter portion 24C for expanding the compressed air that has passed through the operating portion 3, the flow velocity of the compressed air can be reduced by the expansion. Therefore, the compressed air and the drain can be efficiently separated.

Further, since the drain chamber 22e is located closer to the compressed air exhaust port 22b than the operating portion 3, it is possible to reliably prevent the separated drain from entering the operating portion 3 again.

Further, the housing 2 is defined between the compressed air intake port 22a and the operating portion 3 so as to be adjacent to the exhaust pipe 24, and has a pressure accumulator chamber 22c for storing the compressed air flowing in from the compressed air intake port 22a. Therefore, compressed air can be stably supplied from the accumulator chamber 22c to the operating unit 3.

Further, since the housing 2 has the grip portion 22A and at least a part of the accumulator chamber 22c and the exhaust pipe 24 is provided in the grip portion 22A, the space in the grip portion 22A can be effectively utilized and the air pressure can be effectively utilized. It is possible to reduce the size of the tool.

Further, since the drain chamber 22e is provided between the grip portion 22A and the compressed air exhaust port 22b, the grip portion 22A, the drain chamber 22e, and the compressed air exhaust port 22b are arranged in this order from the upstream side of the compressed air flow. The drain is separated from the compressed air by the exhaust pipe 24 and the drain separator 24E arranged in the grip portion 22A, the separated drain is stored in the drain chamber 22e, and the compressed air excluding the drain is exhausted from the compressed air exhaust port 22b. You can do things efficiently.

Further, since the housing 2 has an expansion space 22h defined between the exhaust pipe 24 and the compressed air exhaust port 22b to expand the compressed air, the air after the drain is separated by the exhaust pipe 24 and the drain separator 24E. The air flow rate can be reduced to allow gentle exhaust. Therefore, it is possible to reduce the exhaust noise and the exhaust pressure when using the pneumatic tool.

Further, according to the exhaust pipe 24, the compressed air flowing into the inflow portion 24A is once throttled by the throttle portion 24B to increase the flow velocity, and is expanded again by the large diameter portion 24C to decrease the flow velocity. The compressed air and the drain can be efficiently separated by the dew condensation caused by the adiabatic expansion of the drain separator 24E provided on the large diameter portion 24C.

Further, by providing the circulation path 24D having the communication hole 24I, the air pressure in the drain chamber 22e can be made lower than the air pressure in the large diameter portion 24C by utilizing the flow velocity of the compressed air in the throttle portion 24B. As a result, the drain separated by the drain separator 24E can be drawn into the drain chamber 22e. Therefore, it is not necessary to connect an exhaust device such as a vacuum pump to the drain chamber 22e, and the drain can be drawn into the drain chamber 22e with a simple configuration.

Further, by using the drain separator 24E, the drain can be separated from the compressed air by a simple structure.

<Second embodiment>
Next, the pneumatic tool 101 according to the second embodiment will be described with reference to FIG. Pneumatic tool 101 has the exhaust pipe 124 instead of the exhaust pipe 24, the filter 124E instead of the drain separator 24E, and the muffler 122E instead of the muffler 22E. It has the same configuration as the pneumatic tool 1 according to the form. The same components are designated by the same reference numerals, and the description thereof will be omitted.

The exhaust pipe 124 includes an inflow portion 124A, a throttle portion 124B having an inner diameter smaller than the inner diameter of the inflow portion 124A, a large diameter portion 124C having an inner diameter larger than the inner diameter of the throttle portion 124B, and a space inside the throttle portion 124B. It has a circulation path 124D that communicates with the drain chamber 22e. The inflow portion 124A communicates with the exhaust chamber 21e (FIG. 1). The circulation path 124D is a space in which the throttle portion 124B and the drain chamber 22e communicate with each other like the circulation path 24D, but the circulation path 24D communicates only with the lower side of the drain chamber 22e. The circulation path 124D differs in that it is formed in an annular shape so as to surround the radial outer side of the partition wall 22D. Further, the communication hole 124I is formed so as to extend in the radial direction of the partition wall 22D. By connecting the drain chamber 22e to the throttle portion 124B by the circulation path 124D and the communication hole 124I, the air pressure in the drain chamber 22e can be made lower than the air pressure in the large diameter portion 124C. The circulation path 124D and the communication hole 124I are examples of negative pressure means.

The large diameter portion 124C has a stepped portion 24F like the large diameter portion 24C, and a filter 124E for separating drain from compressed air and a muffler 122E for removing dust and the like from air are provided in the large diameter portion 124C. There is. Specifically, the filter 124E is fitted and fixed to the step portion 24F. The filter 124E is an oil separation filter, and can separate compressed air containing drain into compressed air and drain. The filter 124E has a cylindrical shape having an outer diameter substantially the same as the inner diameter of the large diameter portion 124C, and has a wedge-shaped recess 124a formed therein. The deepest portion of the recess 124a is arranged on the axis of the large diameter portion 124C. The muffler 122E is a filter having a finer mesh than the filter 124E, and is configured so that only air can pass through without draining. The muffler 122E has a shape that fits into the recess 124a of the filter 124E, and its rear end is fixed by the partition wall 22D.

According to such a configuration, the compressed air passes through the filter 124E and the muffler 122E, and the drain contained in the compressed air is separated and recovered by the filter 124E. The separated drain is guided along the surface of the muffler 122E and stored in the drain chamber 22e.

From the above, according to the pneumatic tool 101 according to the second embodiment, the drain can be separated and stored from the compressed air by the air resistance of the filter 124E having a simple structure using the filter 124E.

<Third embodiment>
The pneumatic tool 201 according to the third embodiment will be described with reference to FIG. The pneumatic tool 201 has the same configuration as the pneumatic tool 1 except that it has an exhaust pipe 224 instead of the exhaust pipe 24 and does not include a drain separator 24E. The same components are designated by the same reference numerals, and the description thereof will be omitted.

Like the exhaust pipe 24, the exhaust pipe 224 has an inflow portion 24A, a throttle portion 24B, a circulation path 24D, and a large diameter portion 224C having a diameter larger than the inner diameter of the throttle portion 24B. A plurality of baffle plates 225 are provided on the inner peripheral surface of the large diameter portion 224C. More specifically, the upper baffle plate 225A shown in FIG. 13 (c) and the lower baffle plate 225B shown in FIG. 13 (b) are alternately arranged so as to partially overlap when viewed from the front-rear direction. There is. The upper baffle plate 225A is inclined from the vicinity of the center in the front-rear direction of the large-diameter portion 224C toward the rear diagonally upper side, and closes the upper portion of the space in the large-diameter portion 224C. The lower baffle plate 225B is inclined from the vicinity of the center in the vertical direction of the large diameter portion 224C toward the rear diagonally downward side, and closes the lower portion of the space in the large diameter portion 224C. The upper baffle plate 225A and the lower baffle plate 225B are arranged so as to partially overlap each other in the vicinity of the center of the large diameter portion 224C in the vertical direction when viewed from the front-rear direction.

According to such a configuration, the compressed air flowing from the throttle portion 24B into the large diameter portion 224C flows backward while colliding with the plurality of upper baffle plates 225A and the plurality of lower baffle plates 225B. The reduced speed of the compressed air collides with the baffle plate 225, so that the drain is separated from the compressed air. The separated drain flows on the baffle plate 225, travels along the side wall of the large diameter portion 224C and the flow path 22f, and is stored in the drain chamber 22e.

From the above, according to the pneumatic tool 201 according to the third embodiment, the drain is separated from the compressed air and stored by the resistance and centrifugal force of the baffle plate 225 having a simple structure in which a plurality of baffle plates 225 are provided. be able to.

The power tool according to the present invention is not limited to the above-described embodiment, and various modifications and improvements can be made within the scope of claims.

<Modification example>
For example, in the first to third embodiments, the rear end portion 22B of the housing 2 has a partition wall 22D, but instead of the partition wall 22D, compressed air exhaust is performed as shown in FIG. A partition wall having a cylindrical wall portion 222A protruding from the mouth 22b toward the exhaust pipe 24 and an end portion 222B protruding outward in the circumferential direction from the front end portion (exhaust pipe 24 side end portion) of the wall portion 222A. 222 may be provided. According to such a configuration, when the amount of drain stored in the drain chamber 22e increases due to the provision of the end portion 222B on the partition wall 222, or when the operator changes the posture of the pneumatic tool. Even so, it is possible to prevent the drain from entering the air passage 22g beyond the partition wall 222.

Further, as another modification, in the pneumatic tool according to the first to third embodiments, as shown in FIG. 15, a cock type capable of discharging the drain in the drain chamber 22e to the outside through the drain discharge hole 22j. The discharge valve 22G may be provided. According to the modification shown in FIG. 15, by providing the drain bolt 24J or the discharge valve 22G in the drain discharge hole 22j, it is possible to more reliably suppress the drain from leaking from the drain discharge hole 22j. Further, since the drain can be discharged from the drain chamber 22e to the outside by the operator removing the drain bolt 24J or operating the discharge valve 22G, the drain that cannot be stored beyond the capacity of the drain chamber 22e is exhausted together with the compressed air. It is possible to suppress the exhaust from the compressed air exhaust port 22b.

Further, as a detection unit for detecting the amount of drain stored in the drain chamber 22e, a detection window may be provided so that the state inside the drain chamber 22e can be visually confirmed from the outside. Further, the detection window may be provided with a scale indicating the amount of drainage. According to such a configuration, the amount of drain stored in the drain chamber 22e can be confirmed, the drain can be discharged and recovered at an appropriate timing, and the state inside the pneumatic tool can be grasped from the state of the drain. be able to.

Further, in the first to third embodiments, as the separation means for separating the drain from the compressed air, an exhaust pipe 24 having a drain separator 24E, an exhaust pipe 124 having a filter 124E and a muffler 122E, and a plurality of baffle plates. An exhaust pipe 224 having 225 was used, but the separation means is not limited to this. For example, in the exhaust pipe 24, instead of the drain separator 24E, a centrifugal fin that separates the drain from the compressed air that has passed through the operating portion 3 by centrifugal force when passing through the fin may be provided. According to such a configuration, the drain can be separated from the compressed air by the centrifugal force of the centrifugal fin having a simple configuration.

<Fourth Embodiment>
The pneumatic tool 301 according to the fourth embodiment will be described with reference to FIGS. 16 to 22. The pneumatic tool 301 has an exhaust pipe 324 instead of the exhaust pipe 24 of the pneumatic tool 1, and newly includes an exhaust port cover 329. Further, the pneumatic tool 301 does not have a structure in the pipe such as the partition wall 22D and the drain separator 24E that the pneumatic tool 1 has. The same configuration as that of the pneumatic tool 1 will be designated by the same reference numerals and the description thereof will be omitted.

As shown in FIG. 16, the pneumatic tool 301 has a filter mechanism 327 inserted inside the exhaust pipe 324. The filter mechanism 327 is arranged between the operating portion 3 and the compressed air exhaust port 22b side along the extending direction of the exhaust pipe 324.

As shown in FIG. 17, the filter mechanism 327 includes a filter 327A (corresponding to the oil separation filter of the present invention) and a support member 327B. As shown in FIG. 18, the support member 327B is a plate-shaped rectangular member extending in the front-rear direction, and forms a plurality of holes 327c arranged at equal intervals in the front-rear direction. The support member 327B has substantially the same width as the inner diameter of the exhaust pipe 324 and substantially the same length as the exhaust pipe 324. The filter 327A is a flexible string-like member, and is used as a pair of filters 327A by folding back at the end as shown in FIG. It should be noted that a plurality of filters 327A may be used instead of folding back. Each of the pair of filters 327A is woven into every other hole 327c and held so as to appear alternately on the left and right surfaces of the support member 327B. Further, each of the pair of filters 327A is fixed so as not to pass through the same hole among the plurality of holes 327c but to pass through the plurality of holes 327c alternately (FIGS. 17A and 17B). As shown in FIG. 17B, each of the filters 327A forms a continuous wave shape in a cross-sectional view, and is arranged so as to be offset by half a wavelength from each other. That is, the filter 327A is configured so as to be undulating on the left and right surfaces of the support member 327B, and the crescent-shaped filters 327A are arranged in a row on the left and right surfaces in a cross-sectional view.

The filter 327A allows air to pass through, but has a function of collecting oil, moisture, dust, etc., that is, drain. Specific examples of the material of the filter 327A include nylon fiber, sponge, felt, cotton, polymer absorber, etc., and are made of a flexible material.

The support member 327B does not necessarily have to have a plate shape, and it is sufficient that the filter 327A can be held in the above shape. Further, the filter 327A does not have to be composed of a pair, and may be composed of only one filter. Further, the direction in which the filter 327A protrudes does not have to be the left-right direction, and a corrugated shape may be formed vertically.

As shown in FIG. 19, the exhaust port cover 329 is provided at the rear end of the exhaust pipe 324 and at the rear end 22B of the handle 22. The exhaust port cover 329 is configured to cover the upper part of the rear surface of the rear end portion 22B. The exhaust port cover 329 enables exhaust from the exhaust pipe 324 by forming a plurality of compressed air exhaust ports 22b. The total area of the plurality of compressed air exhaust ports 22b is larger than the hollow partial cross-sectional area of the exhaust pipe 324. The exhaust port cover 329 is fixed to the rear end portion 22B by two screws 329A, so that the exhaust port cover 329 is prevented from falling off during work. In FIG. 19, Phillips screws are shown as screws 329A, but these may be fasteners such as screws that can be attached and detached by hand, or a fitting type made of a plastic material.

During the operation of the pneumatic tool 301, the compressed air passes through the exhaust pipe 324 and is exhausted through the compressed air exhaust port 22b. In this process, the filter mechanism 327 uses the filter 327A to separate the drain from the compressed air passing through the exhaust pipe 324. In detail, as shown in FIG. 17 (c), since the filter 327A forms a wavy shape in which the filter 327A undulates to the left and right with respect to the traveling direction of the compressed air, the compressed air has the filter 327A and the hollow portion. It travels backward in the exhaust pipe 324 while passing alternately. When passing through the filter 327A, the drain in the compressed air is collected by being adsorbed by the filter 327A or the like.

In the above embodiment, since the compressed air from which the drain has been removed is exhausted from the compressed air exhaust port 22b, there is no risk that the drain will scatter and pollute the surroundings, and high workability and environmental friendliness can be realized. Have. Further, since the filter 327A meanders in the traveling direction of the compressed air (or the extending direction of the support member 327B) and has a wavy undulating shape, it hinders the passage of the compressed air in the drain separation process. Therefore, the drain can be separated efficiently without generating a strong resistance. That is, the drain can be separated and removed more easily.

Further, since the exhaust port cover 329 can be attached to and detached from the rear end portion 22B, the filter mechanism 327 can be replaced. The operator removes the exhaust port cover 329 when the drain separation function of the filter mechanism 327 deteriorates, such as when the filter mechanism 327 cannot store the drain, and replaces it with a new filter mechanism 327 via the rear end portion 22B. Therefore, the drain separation function of the pneumatic tool 301 can be restored. Alternatively, the operator can easily restore the drain separation function of the filter mechanism 327 by taking out the filter mechanism 327, cleaning it, and returning it to the inside of the exhaust pipe 324.

In the above embodiment, the filter 327A has a meandering and wavy shape, but the present invention is not limited to this shape. The same effect as described above can be obtained even when the shape of the filter is configured to form a spiral shape with respect to the traveling direction of the compressed air or the extending direction of the support member 327B.

<First modification according to the fourth embodiment>
The configuration of the filter mechanism 327 is not limited to the above configuration. FIG. 20 shows a cylinder type filter 328 which is a first modification of the fourth embodiment. The filter 328 is formed of a flexible cylindrical member. The outer diameter of the filter 328 is substantially equal to the inner diameter of the exhaust pipe 324. The filter 328 has a function of allowing air to pass through but collecting drainage. Specific examples of the specific material of the filter 328 include nylon fibers, sponges, felts, cottons, polymer absorbers, and the like. The filter 328 corresponds to the filter mechanism and the oil separation filter of the present invention.

Even when the filter 328 is arranged inside the exhaust pipe 324 instead of the filter mechanism 327 for work, the drain can be separated in the same manner as the filter mechanism 327. When the compressed air passes through the exhaust pipe 324, the drain is separated from the compressed air that has passed through the filter 328, so that the compressed air from which the drain has been removed is exhausted from the compressed air exhaust port 22b. Therefore, there is no possibility that the drain will scatter and stain the periphery of the pneumatic tool 301, and high workability and environmental friendliness will be realized. Further, by replacing or cleaning the filter 328, the drain separation function of the pneumatic tool 301 can be easily restored.

The shape of the filter mechanism is not limited to the above configuration, and may be configured to cover the compressed air exhaust port 22b. As a specific example, FIG. 21 shows a second modification of the fourth embodiment.

<Second modification according to the fourth embodiment>
In the second modification, as shown in FIG. 21, the filter chamber 324a is defined behind the exhaust pipe 324 and in front of the exhaust port cover 329. The outer circumference of the filter chamber 324a has substantially the same shape as the outer circumference of the exhaust port cover 329 in the front-rear direction, and the front-rear direction viewing area of the filter chamber 324a is larger than the cross section of the hollow portion of the exhaust pipe 324. A filter 330 is arranged inside the filter chamber 324a. The filter 330 is configured to cover the entire compressed air exhaust port 22b when viewed forward. Further, the thickness of the filter 330 in the front-rear direction is shorter than the inner dimension of the filter chamber 324a in the front-rear direction by the gap d. The filter 330 corresponds to the filter mechanism and the oil separation filter in the present invention.

When the compressed air passes through the exhaust pipe 324 and reaches the filter chamber 324a during the work, the filter 330 moves rearward due to the pressure of the compressed air and comes into contact with the exhaust port cover 329. When the filter 330 comes into contact with the exhaust hole cover 329, a gap d is generated inside the filter chamber 324a and in front of the filter 330. The compressed air passes through this gap d and moves backward. Since the cross section of the filter chamber 324a is larger than the cross section of the hollow portion of the exhaust pipe 324, the compressed air entering the filter chamber 324a expands, and the flow velocity and pressure thereof are reduced. Compressed air with reduced pressure causes dew condensation by adiabatic depressurization (adiabatic expansion). Since the filter 330 in contact with the exhaust port cover 329 covers the entire compressed air exhaust port 22b, the compressed air always passes through the filter 330 before being exhausted through the compressed air exhaust port 22b. When the compressed air passes through the filter 330, the drain contained in the compressed air or the dew-condensed drain is separated and removed from the compressed air by the filter 330.

In the configuration of the second modification, the same effect as that of the fourth embodiment can be obtained. In addition to these effects, in the second modification, since the flow velocity and pressure of the compressed air decrease inside the filter chamber 324a, there is an effect that the exhaust noise and the exhaust pressure of the compressed air are reduced. Further, the drain is condensed due to the adiabatic depressurization generated inside the filter chamber 324a, so that the drain can be separated more easily by the filter 330. In other words, the filter chamber 324a also functions as an expansion chamber. Further, since the filter 330 having a cross section larger than that of the exhaust pipe 324 is used, the drain can be separated efficiently. Further, since the filter 330 is arranged in the vicinity of the exhaust port cover 329, the operator can more easily replace or clean the filter 330.

The fourth embodiment and the filter mechanism and the usage mode of the filter used in each modification are not limited to the above-described embodiment. It can also be used in combination with the first to third embodiments or modifications.

<Modification example common to the first and fourth embodiments>
As an example, FIG. 22 shows a fourth embodiment and a pneumatic tool 401 which is a further modification of the first embodiment. The pneumatic tool 401 is obtained by arranging the filter mechanism 327 used in the fourth embodiment inside the pneumatic tool 1 according to the first embodiment. Specifically, the filter 327 is arranged inside the exhaust pipe 24. Other configurations are the same as those of the first embodiment.

In the above configuration, the filter mechanism 327 and the exhaust pipe 24, which are separation means, can separate the drain and can store the drain in the drain chamber 22e. Therefore, not only the effect of the invention according to the first embodiment but also the effect of the invention according to the fourth embodiment can be obtained, and the drain in the compressed air can be efficiently separated and stored. It is also possible to arrange the filter mechanism 327 in a storage portion such as an air passage 22 g or in the vicinity of the exhaust port cover 329.

Further, the pneumatic tools 1, 101, 201, 301, and 401 according to the above embodiment are screw driving machines having an operating portion 3 that is operated by compressed air and has an operating portion 3 that strikes, rotates, and tightens a screw 1B which is a stopper. However, the present invention is not limited to this. For example, the pneumatic tool of the present invention may be a nail driving machine that drives a nail that is a stopper with compressed air, or a screw tightening machine that only rotates a screw without hitting with compressed air. May be good.

1, 101, 201, 301, 401 Pneumatic tool 1A Bit part 2 Housing 3 Acting part 4 Rotating body 5 Cylinder part 5a Cylinder chamber 5b Return air chamber 6 Sub-piston part 7 Main piston part 9 Nose part 9a Injection passage 9b Injection hole 10 Magazine 21 Acting part Housing 21a Groove 21b First air passage 21c Second air passage 21d Third air passage 21e Exhaust chamber 21f Fourth air passage 22 Handle 22A Grip 22B Rear end 22C Connection 22D, 222 Partition walls 22E, 122E Muffler 22G Discharge valve 22a Compressed air intake port 22b Compressed air exhaust port 22c Accumulation chamber 22d Exhaust passage 22e Drain chamber (storage unit)
22f Flow path 22g Air passage 22h Expansion space (expansion part)
22j Drain discharge hole 23 Pressure reducing valve 24, 124, 224, 324 Exhaust pipe (separation means)
24A, 124A Inflow part 24B, 124B Squeezing part 24C, 124C, 224C Large diameter part (expansion chamber)
24D, 124D Circulation route 24E Drain separator (separation means)
24F Step part 24G Base part 24H Blade part (Interfering plate: Fin)
24I, 124I Communication hole 24J Drain bolt 25 Operation valve 26 Trigger 31 Air motor 32 Planetary gear mechanism 32A Sun gear 32B Revolution gear 32C Ring gear 41 Spindle 41a Cylinder intake hole 41b Cylinder exhaust hole 41C Recess 42 Slider 42A Convex 42B Air blocking surface 43 Sleeve valve 43a Main valve Vent hole 44 Spring 51 Cylinder 51a Compressed air outflow hole 51b Compressed air inflow hole 52 Plate part 52a Ventilation hole 53 Piston bumper 53A O-ring 53a Through hole 54 Check valve 61 Shaft 61a Air supply hole 61b Air discharge hole 62 Driver bit mounting part 63 Sub-piston 63A O-ring 64 Collar part 71 Main piston 71A Step 71a Upper hollow space 71b Lower hollow space 71c Communication holes 72, 73, 74 O-ring 91 Push lever 91b Injection hole 92 Screw feed part 124E Filter ( Oil separation filter)
124a Recess 222A Wall 222B End 225 Baffle plate 225A Upper baffle plate 225B Lower baffle plate 327, 328 Filter mechanism 329 Exhaust port cover 330 Filter

Claims (9)

A housing having a compressed air intake port, a compressed air exhaust port, and a grip portion,
An actuating portion supported by the housing and actuated by the compressed air flowing in from the compressed air intake port to hit the stopper or rotate the stopper.
A control unit that controls the inflow of compressed air from the compressed air intake port to the operating unit,
An exhaust passage provided between the operating portion and the compressed air exhaust port through which the compressed air discharged from the operating portion passes,
One end is arranged in the exhaust passage, and the inside has a tubular partition wall forming an air passage communicating with the compressed air exhaust port.
The outer wall of the tubular partition wall is separated from the inner wall of the exhaust passage, and a space is formed between the outer wall of the tubular partition wall and the inner wall of the exhaust passage .
The compressed air can be discharged to the inside of the tubular partition wall and the outside of the housing through the compressed air exhaust port without passing through the space, and is via the inside of the tubular partition wall. drainable der Ru pneumatic tool to the outside of the housing through the space without. The pneumatic tool according to claim 1, wherein the exhaust passage is provided in the grip portion, and a rear end portion having the compressed air exhaust port is provided at the end portion of the grip portion. The pneumatic tool according to claim 2, wherein the rear end portion is configured so that drain accumulated in the space can be discharged. Pneumatic tool according to claim 2 or 3, characterized in that an exhaust outlet cover independently of the compressed air inlet is provided detachably on the rear end. A filter that adsorbs drain contained in compressed air passing through the air passage is held between the rear end portion and the exhaust port cover, and the filter can be attached and detached by removing the exhaust port cover. The pneumatic tool according to claim 4. To the exhaust passage, as claimed in any one of claims 1 to 5 towards the upstream side of the downstream side in the exhaust direction of the compressed air, characterized in that the stepped portion passage width is narrowed is provided Pneumatic tool. The space is communicated with the outside through the compressed air outlet, any one of claims 1 to 6, wherein the communicating with the outside through a drain outlet away from the compressed air outlet The pneumatic tool described in item 1. The exhaust passage has an exhaust pipe whose inside communicates with the operating portion, one end of the partition wall is located inside the exhaust pipe, and the inside wall of the exhaust pipe is located between the outer wall of the partition wall. The pneumatic tool according to any one of claims 1 to 7, wherein a space is formed. The pneumatic tool according to any one of claims 1 to 8, wherein a drain collecting filter for adsorbing drain accumulated in the space is provided.

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