JP7103107B2 - Pneumatic tools - Google Patents

Description

The present invention relates to an air tool having an operating portion operated by compressed air, a housing supporting the operating portion, and an exhaust passage for discharging compressed air to the outside of the housing after the compressed air operates the operating portion. ..

Patent Document 1 describes an example of an air tool having an operating portion operated by compressed air, a housing supporting the operating portion, and an exhaust passage for discharging compressed air in the housing to the outside of the housing. The pneumatic tool described in Patent Document 1 has a housing having a handle, an operating portion, a pressure accumulator chamber provided in the handle, a trigger, a push lever, a trigger valve, and a first ventilation path provided in the handle. A second vent and an oil chamber are provided on the handle. The first vent is connected to the second vent and the drain exhaust hole. The second ventilation path and the drain exhaust hole are arranged in parallel. A muffler is provided in the second air passage, and a drain bolt seals the oil chamber.

In the hitting work machine described in Patent Document 1, when an operating force is applied to the trigger and the push lever is pressed against the mating material, compressed air in the accumulator chamber is supplied to the operating portion to operate the operating portion. The compressed air that has actuated the operating portion is distributed to the second vent and the drain exhaust hole through the first vent. When the compressed air passing through the second ventilation path is discharged to the outside of the hugging, the muffler reduces the exhaust noise.

Oil is supplied to the accumulator chamber to lubricate the inside of the housing. The oil reaches the first vent through the actuating part. The oil that has reached the first ventilation passage enters the oil chamber together with the compressed air flowing through the first ventilation passage, and the oil collects in the oil chamber. The operator removes the drain bolt and drains the oil from the oil chamber.

JP 2015-164756

The inventor of the present application has recognized the problem that the flow resistance of compressed air in the first air passage increases in an air tool that stores oil that lubricates a working portion in an oil chamber.

An object of the present invention is to provide an air tool capable of suppressing an increase in the flow resistance of compressed air in the first air passage.

The air tool of one embodiment includes an actuating portion operated by compressed air, a housing supporting the actuating portion, a first vent passage through which the compressed air operates after operating the actuating portion, and the first vent passage. An exhaust passage that discharges the compressed air flowing through the housing to the outside of the housing, an oil chamber that holds the oil discharged from the first ventilation passage, and a second ventilation that connects the first ventilation passage and the exhaust passage. It has a passage, a passage that connects the oil chamber and the exhaust passage without passing through the second ventilation passage, and discharges the compressed air that has flowed into the oil chamber to the outside of the housing.

The air tool of one embodiment can suppress the flow resistance of compressed air in the first air passage.

It is a side sectional view which shows the whole structure of the screw driving machine which is one Embodiment of the pneumatic tool of this invention. It is a side sectional view which shows the operating part provided in the screw driving machine. It is a side sectional view which shows the actuating part, a trigger valve and a trigger provided in a screw driving machine. It is sectional drawing which shows the internal structure of the handle provided in the screw driving machine. It is sectional drawing which shows the fixed structure of the oil cover and the exhaust cover attached to the handle. FIG. 5 is a cross-sectional view taken along the line VI-VI of FIG. It is a perspective view of the state which disassembled the handle, the oil cover and the exhaust cover.

A screw driving machine according to an embodiment of the pneumatic tool of the present invention will be described with reference to the drawings.

The screw driving machine 10 shown in FIG. 1 includes a housing 11, an injection unit 12, an air motor 13, a driver 14, and a magazine 15. The housing 11 is made of metal or non-ferrous metal, and the housing 11 has a main body 16, a handle 17, and a head cover 18. The main body 16 has a tubular shape, and the handle 17 is connected to the main body 16. The head cover 18 closes the opening of the main body 16, and the head cover 18 is fixed to the main body 16. The air motor 13 is provided in the head cover 18.

The handle 17 has a tubular shape, and the accumulator chamber 19 is formed in the main body 16 and the handle 17. Compressed air is supplied from the air hose to the accumulator chamber 19. The exhaust pipe 20 is provided in the handle 17, and the first exhaust passage 21 is formed in the exhaust pipe 20. The exhaust pipe 20 airtightly separates the accumulator chamber 19 and the first exhaust passage 21. The first exhaust passage 21 is indirectly connected to the outer B1 of the housing 11.

As shown in FIG. 2, the cylinder 22 is fixedly provided in the main body 16. The main body 16 has a passage 23, and the passage 23 is always connected to the accumulator chamber 19. An air chamber 24 and a return air chamber 25 are formed between the cylinder 22 and the main body 16. A passage 26 penetrating the cylinder 22 in the radial direction is provided, and the passage 26 is connected to the air chamber 24.

The spindle 27 is provided in the main body 16 and in the cylinder 22. The spindle 27 has a cylindrical shape and can rotate about the axis A1. The spindle 27 does not operate in the axis A1 direction. Supply / exhaust ports 28 and 29 that penetrate the spindle 27 in the radial direction are provided. The inside 30 of the spindle 27 is connected to the air supply / exhaust ports 28 and 29.

A slider 31 is provided inside 30 of the spindle 27. The slider 31 can be operated in the axis A1 direction with respect to the spindle 27, and the slider 31 and the spindle 27 are connected so as to rotate integrally.

An air chamber 32 is formed in the head cover 18, and the air chamber 32 is connected to the air chamber 24 via a passage 33. The passage 33 is provided over the main body 16 and the head cover 18. The air motor 13 has a rotating shaft 34 and a vane 35. A support wall 36 and a partition wall 37 are provided in the head cover 18, and a storage chamber 38 is formed between the support wall 36 and the partition wall 37. A plurality of vanes 35 are provided on the outer peripheral surface of the rotating shaft 34. The air chamber 32 and the accommodation chamber 38 are connected to each other. A passage 39 is provided over the head cover 18 and the main body 16. The passage 39 is connected to the accommodation chamber 38 and the first exhaust passage 21.

The speed reducer 40 is provided in the main body 16. The speed reducer 40 connects the rotating shaft 34 and the spindle 27.

The first piston 41 is arranged in the spindle 27 and in the cylinder 22. The first piston 41 can operate in the axis A1 direction with respect to the spindle 27 and the cylinder 22. A passage 42 that penetrates the first piston 41 in the radial direction is formed.

The second piston 43 is fixed to the slider 31. The second piston 43 can be operated in the axis A1 direction together with the slider 31, and can rotate integrally with the slider 31. The second piston 43 is arranged from the inside to the outside of the first piston 41. The second piston 43 is fixed to the driver 14. As shown in FIG. 3, a bumper 44 is provided in the main body 16. The bumper 44 is annular, and the driver 14 can operate in the bumper 44 in the axis A1 direction. An air chamber 47 is provided between the bumper 44 and the first piston 41 in the cylinder 22.

Passages 45 and 46 that penetrate the cylinder 22 in the radial direction are provided. The passage 46 always connects the air chamber 47 and the return air chamber 25. Compressed air is filled in the return air chamber 25 and the air chamber 47.

As shown in FIG. 2, a sleeve valve 48 is provided in the main body 16. The sleeve valve 48 can be operated in the axis A1 direction. The sleeve valve 48 has a passage 49. The passage 49 is always connected to the first exhaust passage 21. An air chamber 50 is provided inside the housing 11 on the outer side in the radial direction of the cylinder 22. A passage 51 is connected to the air chamber 50. A spring 52 is provided in the air chamber 50.

A trigger valve 53 is provided in the housing 11. The trigger valve 53 has a body 54, a valve body 55, a plunger 56, and a spring 57. A passage 58 is provided in the body 54, and the passage 58 is connected to the air chamber 50 via the passage 51.

A trigger 59 is attached to the housing 11 via a support shaft 60. The trigger 59 can be operated within a range of a predetermined angle about the support shaft 60. The trigger arm 61 is attached to the trigger 59.

The injection portion 12 is fixed to the main body portion 16, and the injection portion 12 has an injection path. The push lever 62 is operably provided with respect to the injection portion 12. An arm 64 is provided on the injection portion 12, and the arm 64 is connected to a push lever 62. The arm 64 can be operated in the axis A1 direction together with the push lever 62. The magazine 15 houses the screws 63, and the screws 63 are connected to each other by a connecting element, for example, a plastic sheet. A feeder is provided in the injection section 12, and the feeder sends the screw 63 to the injection path. The driver 14 comes into contact with the screw 63 sent to the injection path.

Next, a usage example of the screw driving machine 10 will be described. Compressed air is supplied from the air hose to the accumulator chamber 19. When the push lever 62 is separated from the mating material W1 or the operating force on the trigger 59 is released, the trigger valve 53 is in the initial state. When the trigger valve 53 is in the initial state, the trigger valve 53 connects the accumulator chamber 19 and the passage 58.

The sleeve valve 48 connects the passage 49 and the air supply / exhaust port 29, and shuts off the passage 23 and the air supply / exhaust port 28. Therefore, the air inside the spindle 27 passes through the air supply / exhaust port 28, the passage 49, and the first exhaust passage 21, and is discharged to the outside B1 of the housing 11.

The slider 31 comes into contact with the speed reducer 40 and stops. The first piston 41 is pressed against the slider 31 and is stopped. In this way, the slider 31, the first piston 41, the second piston 43, and the driver 14 are stopped at top dead center. Further, the inside 30 and the air chamber 24 are cut off, compressed air is not supplied from the air chamber 24 to the air chamber 32, and the rotating shaft 34 of the air motor 13 is stopped.

Next, when the operator presses the push lever 62 against the mating material W1 and applies an operating force to the trigger 59, the operating force of the push lever 62 is transmitted to the plunger 56 via the trigger arm 61, and the trigger valve 53 Is in operation. When the trigger valve 53 is in the operating state, the trigger valve 53 shuts off the accumulator chamber 19 and the passage 58.

Then, the sleeve valve 48 is operated by the compressed air supplied to the air chamber 50 and the force of the spring 52. The sleeve valve 48 connects the passage 23 and the air supply / exhaust port 28, and shuts off the air supply / exhaust port 28 and the air supply / exhaust port 29. Therefore, the compressed air in the accumulator chamber 19 is supplied from the passage 23 to the inside 30. Then, the first piston 41 operates in a direction away from the speed reducer 40 by the air pressure inside 30. In this way, the first piston 41 is separated from the slider 31.

After that, when the compressed air inside 30 is supplied to the accommodating chamber 38 via the passage 33 and the air chamber 32, the rotating shaft 34 of the air motor 13 rotates. The rotational force of the rotating shaft 34 is transmitted to the spindle 27 via the speed reducer 40. Therefore, the second piston 43 and the driver 14 rotate. The compressed air supplied into the accommodation chamber 38 flows to the first exhaust passage 21 through the passage 39.

Then, the second piston 43 and the slider 31 operate in the axis A1 direction together with the first piston 41. In this way, the driver 14 rotates and operates in the direction of the axis A1, so that the screw 63 is pressed against the mating material W1 and the screw 63 is tightened. While the first piston 41 is operating so as to be separated from the speed reducer 40, the air in the air chamber 47 flows into the return air chamber 25 via the passage 45.

After the driver 14 completes tightening the screw 63, the slider 31 stops, and the inside 30 and the air chamber 24 are shut off. Therefore, the compressed air is not supplied to the air chamber 32, and the air motor 13 stops. Further, after the tightening of the screw 63 is completed, the second piston 43 collides with the bumper 44.

When the operator releases the operating force on the trigger 59 after the tightening of the screw 63 is completed, the trigger valve 53 returns to the initial state, connects the passage 58 and the accumulator chamber 19, and is outside the passage 58 and the housing 11. It shuts off from B1. Then, the sleeve valve 48 shuts off the passage 23 and the air supply / exhaust port 28, and connects the air supply / exhaust port 29 and the passage 49. Therefore, the air inside the interior 30 flows into the first exhaust passage 21 via the air supply / exhaust port 29 and the passage 49, and the air pressure inside the interior 30 drops.

When the air pressure inside the inner 30 drops, the second piston 43 and the slider 31 operate as they approach the speed reducer 40 under the pressure of the air chamber 47. Further, the compressed air in the return air chamber 25 is supplied to the air chamber 47 via the passage 46. Then, the first piston 41 rises together with the second piston 43 so as to approach the air motor 13. Then, when the slider 31 comes into contact with the speed reducer 40, the slider 31 and the second piston 43 stop at the top dead center. Further, the first piston 41 operates by the air pressure of the air chamber 47 even after the second piston 43 is stopped, and when the first piston 41 comes into contact with the slider 31, the first piston 41 stops at the top dead center.

Next, the structure of the path for supplying compressed air to the accumulator chamber 19 via the air hose will be described with reference to FIGS. 4, 5, 6 and 7. The handle 17 is provided so as to project in a predetermined direction with respect to the main body portion 16. The handle 17 has a large diameter portion 65 at an end opposite to the main body portion 16. The outer diameter of the large diameter portion 65 is larger than the outer diameter of the portion of the handle 17 that the operator holds by hand.

The holder 66 is fixed to the large diameter portion 65 by a screw member 67. The holder 66 has a female screw hole 93. The exhaust cover 68 and the oil cover 69 are fixed to the holder 66 by the screw member 70. The screw member 70 has a shaft portion 94 shown in FIG. 7, and a male screw portion 95 shown in FIG. 5 is formed on the outer peripheral surface of the shaft portion 94. The male screw portion 95 is arranged in the female screw hole 93.

A pressure adjusting valve 71 is provided on the holder 66 and the large diameter portion 65. The pressure adjusting valve 71 has a casing 72, an operating member 73, a valve seat 74, an end cover 75, and a valve body 76. The casing 72 is connected to the holder 66. The casing 72 has a storage chamber 77. The valve seat 74 is arranged between the operating member 73 and the end cover 75 in the direction of the center line A2 of the accommodation chamber 77. The center line A2 intersects the axis line A1. An air chamber 78 is formed between the end cover 75 and the valve seat 74. The plug 79 is attached to the end cover 75. The plug 79 has a passage 80, which is connected to the air chamber 78.

The valve seat 74 has a passage 81, which is connected to the air chamber 78 and the accumulator chamber 19. The actuating member 73 can be actuated in the center line A2 direction with respect to the casing 72. An urging member 82 is provided in the accommodation chamber 77. The urging member 82 urges the operating member 73 so as to approach the valve seat 74 in the center line A2 direction. The urging member 82 is, for example, a metal compression spring.

A shaft 83 is provided on the operating member 73, and the shaft 83 is arranged over the passage 81 and the air chamber 78. A valve body 76 is attached to a portion of the shaft 83 located in the air chamber 78. The valve body 76 is made of synthetic rubber as an example. An urging member 84 is provided in the air chamber 78. The urging member 84 urges the valve body 76 in a direction that brings the valve body 76 closer to the valve seat 74. The urging member 84 is, for example, a metal compression spring.

The compressed air sent from the air hose to the passage 80 of the plug 79 flows into the accumulator chamber 19 via the air chamber 78 and the passage 81. The operating member 73 receives urging forces F1 and F2 opposite to each other in the center line A2 direction. The urging force F1 is the urging force of the urging member 82, and the urging force F2 corresponds to the air pressure in the accumulator chamber 19.

When the urging force F2 is larger than the urging force F1, the operating member 73 relaxes from the valve seat 74 and stops, and the valve body 76 shuts off the air chamber 78 and the passage 81. When the urging force F2 is smaller than the urging force F1, the operating member 73 comes into contact with the valve seat 74 and stops, and the valve body 76 connects the air chamber 78 and the passage 81. When the urging force F1 and the urging force F2 are the same, the operating member 73 does not operate.

When the pressure in the accumulator chamber 19 exceeds a predetermined pressure, the urging force F2 received by the operating member 73 is larger than the urging force F1. When the pressure in the accumulator chamber 19 becomes equal to or lower than the predetermined pressure due to the use of the screw driving machine 10 and the urging force F2 received by the operating member 73 becomes smaller than the urging force F1, the operating member 73 operates in a direction approaching the valve seat 74. In this way, the pressure adjusting valve 71 operates the operating member 73 in response to the pressure in the accumulator chamber 19 to adjust the actual pressure in the accumulator chamber 19 so as to be maintained within a predetermined pressure range.

An operator can supply oil into the housing 11 to lubricate a portion provided in the housing 11. For example, in order to lubricate the sliding portion of the air motor 13, the cylinder 22 and the first piston 41 with oil, the air motor 13 is supplied to the accumulator chamber 19 via the passage 80. The oil flows in the housing 11 and the head cover 18 together with the compressed air supplied to the accumulator chamber 19. Specifically, the compressed air and oil pass through the inside 30, the passage 33, the accommodating chamber 38 and the passage 39, and the compressed air and oil are discharged to the first exhaust passage 21.

The structure for discharging the compressed air discharged to the first exhaust passage 21 to the outside B1 and the structure for capturing the oil discharged to the first exhaust passage 21 are as follows. The holder 66 has a tubular portion 85. The end portion of the exhaust pipe 20 is arranged in the tubular portion 85.
The oil cover 69 is arranged between the holder 66 and the exhaust cover 68 in the A3 direction of the center line of the tubular portion 85. The center line A3 is parallel to the center line A2. The oil cover 69 has an insertion tube 86. The insertion pipe 86 is arranged in the tubular portion 85 and over the first exhaust passage 21. 4 and 5 are examples in which the center line A3 of the insertion tube 86 and the tubular portion 85 is common.

A second exhaust passage 87 is provided in the insertion pipe 86, and the second exhaust passage 87 is connected to the first exhaust passage 21. The oil cover 69 has a wall portion 88 in a direction intersecting the center line A3. The exhaust cover 68 has a wall portion 89 in a direction intersecting the center line A3. An exhaust chamber 90 is formed between the wall portion 88 and the wall portion 89. The exhaust chamber 90 is arranged along a direction intersecting the center line A3, and the exhaust chamber 90 is connected to the second exhaust passage 87. An exhaust port 91 that penetrates the wall portion 89 in the center line A3 direction is provided. The exhaust port 91 connects the exhaust chamber 90 and the external B1.

The exhaust cover 68 has a cylindrical boss portion 102, and the screw member 70 fixes the exhaust cover 68 to the holder 66 in a state where a part of the screw member 70 is arranged in the boss portion 102.

An exhaust filter 92 is provided in the exhaust chamber 90. The exhaust filter 92 has a plate shape. The exhaust filter 92 allows air to pass through, but has a function of capturing dust and the like. Specific examples of the material of the exhaust filter 92 include nylon fiber, sponge, felt, cotton, and a polymer absorber. The exhaust filter 92 has a notch 104, and the boss 102 is located in the notch 104.

The oil cover 69 is made of a separate member from the exhaust cover 68. The material of the exhaust cover 68 and the oil cover 69 is made of synthetic resin or metal. The material of the exhaust cover 68 and the material of the oil cover 69 may be the same or different.

The exhaust cover 68 may be molded of either an opaque synthetic resin or a transparent synthetic resin. The opaque synthetic resin is colored. The transparent synthetic resin is, for example, acrylic or polycarbonate. When the exhaust cover 68 is made of a transparent synthetic resin, the operator can check the adhered state of oil or foreign matter on the exhaust filter 92. Therefore, the operator can easily determine the timing of replacement of the exhaust filter 92.

The third exhaust passage 96 is formed on the outside of the insertion pipe 86. The third exhaust passage 96 is formed between the insertion pipe 86 and the exhaust pipe 20, and between the insertion pipe 86 and the holder 66. The third exhaust passage 96 is formed in an annular shape with the center line A3 as the center. The exhaust pipe 20 and the holder 66 airtightly separate the third exhaust passage 96 from the accumulator chamber 19.

The oil chamber 97 is formed on the outside of the insertion tube 86. The third exhaust passage 96 and the oil chamber 97 are arranged at different positions in the center line A3 direction, specifically, in different ranges. The oil chamber 97 is formed between the holder 66 and the wall portion 88 in the center line A3 direction. The oil chamber 97 is connected to the third exhaust passage 96.

Further, a protrusion 86A is provided on the outer peripheral surface of the insertion tube 86. The protrusion 86A projects from the outer peripheral surface of the insertion pipe 86 toward the exhaust pipe 20 in the radial direction of the insertion pipe 86. The protrusion 86A may be provided over the entire circumference of the insertion tube 86, or may be provided at a part of the entire circumference of the insertion tube 86.

A narrowed portion 108 is formed between the protrusion 86A and the inner peripheral surface of the exhaust pipe 20. The narrowed portion 108 is a part of the third exhaust passage 96. The width of the narrowed portion 108 in the direction intersecting the flow direction of the compressed air is narrower than the width of other portions in the third exhaust passage 96. The narrowed portion 108 allows air containing oil to flow from the first exhaust passage 21 to the oil chamber 97. Further, the narrowed portion 108 prevents the oil accumulated in the oil chamber 97 from flowing back to the first exhaust passage 21.

An oil filter 98 is provided in the oil chamber 97. The oil filter 98 has a plate shape. The oil filter 98 allows air to pass through, but has a function of capturing, for example, absorbing oil. Specific examples of the material of the oil filter 98 include nylon fiber, sponge, felt, cotton, and a polymer absorber.

The oil cover 69 includes an intermediate passage 99 shown in FIG. The intermediate passage 99 connects the oil chamber 97 and the exhaust chamber 90. A partition wall 100 projecting from the wall portion 88 toward the holder 66 in the center line A3 direction is provided. A throttle portion 101 is formed between the partition wall 100 and the holder 66. The throttle portion 101 is a passage connecting the oil chamber 97 and the intermediate passage 99. The arrangement range of the throttle portion 101 in the center line A3 direction is narrower than the arrangement range of the oil chamber 97 in the center line A3 direction and the arrangement range of the intermediate passage 99 in the center line A3 direction.

That is, the flow area of the compressed air in the throttle portion 101 is the flow direction of the compressed air from the oil chamber 97 to the intermediate passage 99, the flow area of the oil chamber 97 upstream of the throttle portion 101, and the middle in the downstream of the throttle portion 101. It is smaller than the distribution area of passage 99.

The oil cover 69 has a cylindrical boss portion 103, and the screw member 70 fixes the oil cover 69 to the holder 66 in a state where a part of the screw member 70 is arranged in the boss portion 103. The oil filter 98 has notches 105 and 106. The boss portion 103 is located in the notch portion 105. The insertion tube 86 is located within the notch 106.

The action of the compressed air being discharged from the first exhaust passage 21 to the outside B1 will be described. A part of the air flowing through the first exhaust passage 21 flows into the second exhaust passage 87. The compressed air flows in the second exhaust passage 87 in the direction of the center line A3. When the compressed air flowing in the second exhaust passage 87 enters the exhaust chamber 90, the wall portion 89 makes the flow direction of the compressed air in the exhaust chamber 90 intersect with the center line A3. The exhaust filter 92 is pressed against the wall portion 89 by the pressure of compressed air. The wall portion 89 supports the exhaust filter 92 so as not to move in the center line A3 direction.

The compressed air flowing in the exhaust chamber 90 passes through the exhaust filter 92 and is discharged from the exhaust port 91 to the outside B1. The exhaust filter 92 captures dust and the like contained in the permeated compressed air. After the compressed air flowing into the exhaust chamber 90 is discharged to the outside B1, the pressure inside the exhaust chamber 90 is maintained at the same atmospheric pressure as the outside B1.

The principle of capturing the oil discharged to the first exhaust passage 21 will be described. The oil discharged to the first exhaust passage 21 adheres to the inner surface of the exhaust pipe 20. The oil adhering to the inner surface of the exhaust pipe 20 moves by the kinetic energy of the compressed air flowing through the first exhaust passage 21, and both the oil and the compressed air flow into the oil chamber 97 via the third exhaust passage 96. do. The oil filter 98 captures the oil that has entered the oil chamber 97.

The compressed air that has entered the oil chamber 97 is regulated by the partition wall 100 as shown by the broken line arrow D1 in FIG. 7, and flows into the exhaust chamber 90 through the throttle portion 101 and the intermediate passage 99. The intermediate passage 99 guides the compressed air to the exhaust chamber 90. In this way, the compressed air flowing through the second exhaust passage 87 and the compressed air flowing through the third exhaust passage 96 and the oil chamber 97 merge in the exhaust chamber 90. The combined compressed air passes through the exhaust filter 92 and is discharged from the exhaust port 91 to the outside B1.

In this way, the oil discharged to the first exhaust passage 21 can be captured by the oil chamber 97. Therefore, it is possible to prevent the oil from being discharged from the exhaust port 91 due to the pressure of the compressed air. In particular, since the oil filter 98 captures the oil in the oil chamber 97, the function of the oil chamber 97 to capture the oil increases.

Further, the compressed air that has flowed from the first exhaust passage 21 into the second exhaust passage 87 is discharged to the outside B1 via the exhaust chamber 90 and the exhaust port 91. Further, the compressed air that has flowed into the oil chamber 97 is discharged to the outside B1 via the throttle portion 101, the intermediate passage 99, and the exhaust chamber 90. In other words, after the compressed air flowing into the oil chamber 97 is discharged to the outside B1, the pressure in the oil chamber 97 is maintained at atmospheric pressure similar to the pressure in the outside B1.

In this way, the compressed air that the air motor 13 rotates and is discharged from the accommodating chamber 38 to the first exhaust passage 21 via the passage 39 is all discharged to the outside B1 via the exhaust chamber 90. Therefore, it is possible to suppress an increase in the flow resistance of the compressed air in the first exhaust passage 21. Therefore, it is possible to prevent the rotation speed of the rotation shaft 34 of the air motor 13 from decreasing, that is, the rotation speed of the driver 14 from decreasing.

Further, when the compressed air inside the spindle 27 is discharged to the first exhaust passage 21 via the air supply / exhaust port 29 and the passage 49 after the driver 14 tightens the screw 63, the flow resistance of the compressed air. Decreases. Therefore, the responsiveness of the first piston 41, the second piston 43, and the driver 14 to return to the top dead center is improved.

Further, the pressure of the first exhaust passage 21 can be defined as the back pressure, and it is possible to suppress the increase of the back pressure of the first exhaust passage 21.

When the operator loosens the screw member 70 and removes the screw member 70 from the holder 66 as shown in FIG. 7, the exhaust cover 68, the exhaust filter 92, the oil cover 69, and the oil filter 98 can be removed from the holder 66. It is possible. The operator can maintain or replace the exhaust filter 92. The operator can maintain or replace the oil filter 98.

By tightening the screw member 70, the exhaust cover 68, the exhaust filter 92, the oil cover 69, and the oil filter 98 can be attached to the holder 66.

Further, the exhaust cover 68 can be provided with the guide portion 107 shown in FIG. The guide portion 107 is located between the second exhaust passage 87 and the exhaust chamber 90 in the flow direction of the compressed air. The guide portion 107 is a protrusion or a blade provided on the inner surface of the exhaust chamber 90. The guide portion 107 changes the flow direction of the compressed air flowing through the second exhaust passage 87, that is, the flow direction in the center line A3 direction, to a direction intersecting the center line A3. Therefore, when the compressed air flows from the second exhaust passage 87 into the exhaust chamber 90, the compressed air diffuses throughout the exhaust port 91, so that the flow resistance of the compressed air can be reduced.

An example of the technical meaning of the matters described in the embodiments is as follows. The screw driving machine 10 is an example of a pneumatic tool. The air motor 13, the spindle 27, the slider 31, the first piston 41, the second piston 43, and the driver 14 are examples of the operating unit. The housing 11 is an example of a housing. The main body 16 is an example of the main body, and the handle 17 is an example of the handle.

The first exhaust passage 21 is an example of the first ventilation passage. The second exhaust passage 87 is an example of the second ventilation passage. The third exhaust passage 96 is an example of the third ventilation passage. The exhaust chamber 90 is an example of an exhaust passage. The oil chamber 97 is an example of an oil chamber. The intermediate passage 99 is an example of a passage and an intermediate passage.

The exhaust pipe 20 is an example of the first ventilation pipe. The insertion pipe 86 is an example of a second ventilation pipe. The oil filter 98 is an example of a catcher. The diaphragm portion 101 is an example of the diaphragm portion. The exhaust filter 92 is an example of a filter that captures foreign matter. The wall portion 89 is an example of the wall portion. The oil cover 69 is an example of the first cover. The exhaust cover 68 is an example of the second cover. The guide unit 107 is an example of the guide unit. The narrowed portion 108 is an example of the narrowed portion.

The pneumatic tool is not limited to the screw driving machine disclosed with reference to the drawings, and can be variously changed without departing from the gist thereof. For example, the pneumatic tool may have any of a first structure, a second structure, and a third structure. In the pneumatic tool of the first structure, the operating portion rotates and the operating portion reciprocates. An example of a pneumatic tool having the first structure is a screwdriver, a hammer drill, and a hammer driver. In the air tool of the second structure, the operating portion rotates and the operating portion does not reciprocate. An example of a pneumatic tool having a second structure is a drill and a screwdriver. In the air tool of the third structure, the operating portion reciprocates and the operating portion does not rotate. An example of the third tool is a hammer and a nail gun. Further, the operating portion operates at least one of the pressure or kinetic energy of the compressed air.

At least one of a first vent, a second vent, a third vent, an exhaust passage, an intermediate passage, and an oil chamber includes at least one of a space, a gap, and a pipeline. The guide section may not be provided.

When a narrowed portion is formed in the third ventilation passage, a protrusion is provided on at least one of the inner surface of the first ventilation pipe and the outer surface of the second ventilation pipe.

In this embodiment, the oil filter 98 may not be provided. In this case, the partition wall 100 holds the oil in the oil chamber 97. That is, the partition wall 100 suppresses the movement of oil by the kinetic energy of compressed air. In the present embodiment, the fact that the oil chamber holds the oil includes the meaning of capturing the oil, storing the oil, storing the oil, suppressing the movement of the oil, and damming the oil.

10 ... Screw driving machine, 11 ... Housing, 13 ... Air motor, 14 ... Driver, 16 ... Main body, 17 ... Handle, 20 ... Exhaust pipe, 21 ... First exhaust passage, 27 ... Spindle, 31 ... Slider, 41 ... No. 1 piston, 43 ... 2nd piston, 68 ... exhaust cover, 69 ... oil cover, 86 ... insertion pipe, 87 ... second exhaust passage, 89 ... wall, 90 ... exhaust chamber, 92 ... exhaust filter, 96 ... third Exhaust passage, 97 ... Oil chamber, 98 ... Oil filter, 99 ... Intermediate passage, 101 ... Squeezing part, 107 ... Guide part, 108 ... Constricted part

Claims (12)

Acting parts operated by compressed air and
A housing that supports the operating part and
A first air passage through which the compressed air passes after operating the operating portion, and
An exhaust passage that discharges the compressed air flowing through the first air passage to the outside of the housing, and
An oil chamber for holding the oil discharged from the first air passage and
A second vent that connects the first vent and the exhaust passage,
An air tool having a passage that connects the oil chamber and the exhaust passage without passing through the second ventilation passage, and discharges the compressed air that has flowed into the oil chamber to the outside of the housing. The air tool according to claim 1, wherein the passage is an intermediate passage that connects the oil chamber and the exhaust passage and guides the compressed air that has flowed into the oil chamber to the exhaust passage. The first ventilation pipe forming the first ventilation passage and
A second ventilation pipe arranged inside the first ventilation pipe and forming the second ventilation passage ,
A third ventilation path formed between the first ventilation pipe and the second ventilation pipe,
Is further provided,
The air tool according to claim 1 or 2, wherein the third ventilation path is connected to the oil chamber. The air tool according to claim 3, wherein the trapping tool for catching the oil is provided in the oil chamber. A throttle portion is provided between the oil chamber and the passage.
The flow area of the compressed air in the throttle portion is based on the flow area upstream of the throttle portion and the flow area downstream of the throttle portion in the flow direction of the compressed air from the oil chamber to the passage. The pneumatic tool according to any one of claims 1 to 4, which is also narrow. The air tool according to claim 4, wherein a filter for capturing foreign matter contained in the compressed air discharged to the outside of the housing through the second ventilation passage and the passage is provided in the exhaust passage. A wall portion forming the exhaust passage is provided, and the wall portion is provided.
The air tool according to claim 6, wherein the wall portion supports the filter urged by the compressed air flowing from the second ventilation passage to the exhaust passage. The air tool according to any one of claims 4, 6 and 7, provided with a guide portion for changing the direction of the compressed air flowing from the second ventilation passage to the exhaust passage. Acting parts operated by compressed air and
A housing that supports the operating part and
A first air passage through which the compressed air passes after operating the operating portion, and
An exhaust passage that discharges the compressed air flowing through the first air passage to the outside of the housing, and
An oil chamber for holding the oil discharged from the first air passage and
Is an air tool with
A passage is provided to discharge the compressed air flowing into the oil chamber to the outside of the housing.
An air tool in which a first cover forming the oil chamber and a second cover forming the exhaust passage are provided as separate members that can be attached to and detached from the housing , respectively. The housing is
Cylindrical body and
A handle that is connected to the main body and that the operator holds by hand,
Have,
The air tool according to claim 9 , wherein the first cover and the second cover can be attached to and detached from the handle, respectively. The air tool according to claim 9 , wherein the second cover is made of a transparent resin. The third vent has a constriction and has a constriction.
The air tool according to claim 3, wherein the narrowed portion has a width in a direction intersecting with the flow direction of the compressed air narrower than the width of another portion in the third air passage.

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