JP2004074299A - Silencer for pneumatic type fastening tool driver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a silencer for a fastening tool driver neither enlarging the fastening tool driver nor depending on the sound absorbing action of a silencing member alone. <P>SOLUTION: This silencer 27 for the fastening tool driver 1 is provided in an outlet of an exhaust passage 26, having a pipe 34 dividing the exhaust passage into an inside exhaust passage 31 and an outside exhaust passage 33, and an exhaust housing (a handle housing end part 9) forming an exhaust chamber 39 for receiving the exhaust and surrounding an exhaust hole part 35 of a pipe 34. The exhaust chamber 39 is provided with a first silencing member 41 for guiding the exhaust from the outside exhaust passage 33 to the outer circumferential surface of the exhaust hole part 35, the first silencing member 41 is disposed in such a position as to allow the outside exhaust passage exhaust fed from the outside exhaust passage 33 to interfere with the exhaust hole part exhaust exhausted from the exhaust hole part 35 and delay the speed of the exhaust hole part exhaust. This constitution thus delays the speed of the exhaust hole part exhaust, and also delays the speed of the outside exhaust passage exhaust. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
[Industrial applications]
The present invention provides a method for returning the piston and the driver after driving the driver connected to the piston by driving the driver by driving the driver connected to the piston by driving the pressurized air to the cylinder to drive the fastener such as a nail or a screw from the nose into the object to be driven. The present invention relates to a pneumatic fastener driving machine for discharging pressurized air in a cylinder to the outside, and more particularly to a noise reduction device provided at an outlet of an exhaust passage of a pneumatic fastener driving machine for reducing exhaust noise.
[0002]
[Prior art]
After sending pressurized air to the cylinder and driving the driver connected to the piston to drive the fasteners such as nails and screws from the nose into the object to be driven, the cylinder and cylinder are returned to return the piston and driver. A pneumatic fastener driving device for discharging compressed air to the outside is well known and is frequently used in construction sites and the like. In this fastener driving machine, when the piston returns from the striking position (bottom dead center position), the pressurized air in the cylinder is rapidly discharged, and the discharged pressurized air is discharged from the exhaust passage to the atmosphere. It becomes noise, and the exhaust noise is quite loud and harsh.
[0003]
[Problems to be solved by the invention]
Various ideas have been devised to mute the exhaust noise. For example, Japanese Patent Application Laid-Open No. 8-71953 (Japanese Patent No. 2778480) discloses a pneumatic nailing machine for driving a U-shaped staple coupling body, in which an exhaust passage is guided to a staple magazine and an inner space of the staple magazine is formed. A device is disclosed that reduces exhaust noise by reducing the pressure of discharged pressurized air using the size and then discharging the depressurized air to the atmosphere. One of the causes of sound generation is direct pressure change, for example, due to turbulence in the flow caused by jetting fluid (air) at high speed ("Noise Reduction Technology" by Yutomo Nakano, Technical Shoin Co., Ltd.) Issue). The noise reduction device also utilizes a staple magazine having a certain internal space to expand and reduce the pressure of the discharged pressurized air, thereby reducing the speed of the discharged pressurized air ejected at a high speed to reduce the turbulence of the air flow. It is considered that exhaust noise is thereby reduced. This device uses a large space in the staple magazine that accommodates the U-shaped staple link to reduce noise, but it can be used to drive other fasteners such as nailers and screw drivers. The same technology cannot be applied to all machines. In addition, it is not desirable to add a special silencing space because the size of the fastener driving machine is increased and the burden on the operator is increased.
[0004]
Another well-known sound reduction mechanism is to provide a sound-absorbing member made of a sound-absorbing material at the outlet of an exhaust passage, which is adopted in many fastener driving machines. However, if the noise reduction effect is small, and if the noise reduction effect is to be increased, the resistance to discharge the pressurized air increases, which hinders the exhaust, and may hinder the return operation of the piston and the driver.
[0005]
Accordingly, it is an object of the present invention to provide a method for reducing the noise of discharged pressurized air without increasing the size of the fastener driving machine and without relying solely on the sound absorbing action of the sound deadening member, even without a noise reducing spacer. It is an object of the present invention to provide a sound reducer for a fastener driving machine that reduces noise.
[0006]
[Means for Solving the Problems]
In order to achieve such an object, the present invention provides a method for driving a driver connected to a piston by sending pressurized air to a cylinder to drive a fastener such as a nail or a screw from a nose into a target to be driven. And a noise reduction device for reducing exhaust noise provided at an outlet of an exhaust passage of a pneumatic fastener driving machine that discharges pressurized air in a cylinder to the outside for returning a driver. A pipe extending in the longitudinal direction of the exhaust passage, which is formed at a cross section smaller than the cross section of the exhaust passage and divides the exhaust passage into an inner exhaust passage and an outer outer exhaust passage, is disposed at an outlet portion of the exhaust passage. A large number of exhaust holes for discharging pressurized air from the inner exhaust passage have exhaust holes formed in the pipe wall, and exhaust air from the inner exhaust passage through the exhaust hole and air from the outer exhaust passage. Forming exhaust chamber to receive exhaust An exhaust housing surrounds an outlet portion of the exhaust passage, and a first silencing member is provided in the exhaust chamber so as to guide exhaust from the outer exhaust passage to the outer peripheral surface of the exhaust hole of the pipe. The first muffling member is provided outside at intervals, and causes the outer exhaust passage exhaust sent from the outer exhaust passage to interfere with the exhaust hole exhaust coming out of the exhaust hole to reduce the speed of the exhaust hole exhaust. The exhaust hole portion exhaust and the outer exhaust passage exhaust are formed of a sound absorbing material that can pass outside the first noise reduction member.
[0007]
According to the present invention, the outlet portion of the exhaust passage is divided into an inner exhaust passage and an outer outer exhaust passage by a pipe, and the inner exhaust passage exhaust is discharged to the exhaust chamber through the exhaust hole of the pipe, and the outer exhaust passage is formed. Exhaust from the exhaust hole of the pipe is guided to the outer peripheral surface of the exhaust hole of the pipe and interferes with the exhaust hole exhaust coming out of the exhaust hole, so that the speed of the exhaust hole exhaust becomes slow and the speed of the outer exhaust passage exhaust also becomes slow. Accordingly, the flow of the pressurized exhaust air discharged from the exhaust passage flowing at a high speed is reduced to a low speed in the space between the exhaust hole of the pipe and the first noise reduction member, and the turbulence of the air flow is greatly reduced, so that sound is reduced. The exhaust hole exhaust and the outer exhaust passage exhaust slow down the exhaust flow in the space between the exhaust hole of the pipe and the first noise reduction member and the space outside the first noise reduction member, that is, the exhaust chamber. To do It is possible to expand, even more, the exhaust noise is greatly reduced. As described above, in the space between the exhaust hole of the pipe and the first silencing member, the exhaust from the inner exhaust passage and the exhaust from the outer exhaust passage that have passed through the exhaust hole collide with each other, and the exhaust that flows at a high speed. Since the flow of pressurized air is slowed, discharge is possible without requiring a large space such as a magazine, without increasing the size of the fastener driving machine, and without relying solely on the sound absorbing action of the silencing member. Noise of pressurized air is greatly reduced.
[0008]
In the above sound reduction apparatus, the fastener driving machine includes a tool housing including a piston, a driver, and a cylinder; and a handle housing integrally connected to the tool housing to form a grip to be gripped by an operator. Inside, an exhaust passage is formed to extend from the grip to an end of the handle housing, and a pipe is attached to the exhaust passage near an end of the handle housing, with the handle housing portion at the end forming an exhaust housing. Is preferred. Thus, the sound reduction device centered on the exhaust chamber is provided at the end of the handle of the fastener driving machine, and a high sound reduction effect can be obtained without increasing the size of the fastener driving machine. In that case, the exhaust passage inside the handle housing is formed as a cylindrical cavity, and a rib extending in the longitudinal direction is formed on the outer surface of the pipe so that the end side opposite to the exhaust hole is tapered. It is preferable that the pipe is fitted and fixedly arranged in the exhaust passage only by pushing the pipe into the exhaust passage of the cylindrical cavity with a certain pipe portion at the head.
[0009]
The first muffling member has a length between the first muffling member and the evacuation hole of the pipe, which is a length that forms a space in which pressurized air rapidly discharged from the evacuation hole can expand and decelerate. Preferably, they are separated. Further, the exhaust housing is provided with a space further outside the first muffling member and spaced apart from the first muffling member to provide a space for further decelerating the exhaust gas passing through the first muffling member, thereby reducing and reducing the sound. It is preferable that a second silencing member made of a sound absorbing material is disposed so as to discharge the exhaust gas to the atmosphere. Further, a space is provided between the first silencing member and the exhaust housing, and a part of the exhaust from the outer exhaust passage is directly discharged into the exhaust chamber outside the first silencing member without passing through the first silencing member. It is preferable that the cooling caused by the expansion of the exhaust gas passing through the first silencing member in the exhaust chamber is reduced. This prevents freezing in a cold season such as winter, avoids clogging of the exhaust even if the first silencing member freezes, and reduces the burden on the operator due to cooling.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In FIG. 1, a fastener driving machine 1 according to an embodiment of the present invention forms a tool housing 5 for accommodating a piston 2 and a cylinder 3 and a grip 6 integrally connected to the tool housing 5 to be gripped by an operator. The handle housing 7 is provided. A pressurized air supply port 10 is provided at an end portion 9 of the handle housing 7, and pressurized air compressed by a compressor or the like is supplied. A reservoir 11 for storing pressurized air is formed inside the handle housing 7 so that the outside of the cylinder 3 of the tool housing 5 is filled with pressurized air. When the main valve 13 movably arranged on the outer side of the cylinder 3 moves in the direction of the arrow 14, pressurized air is sent into the cylinder 3 from the upper surface (back side) of the piston 2. Accordingly, the piston 2 is rapidly moved downward inside the cylinder 3 together with the connected driver 15. The trigger valve 17 provided on the handle housing 7 moves the main valve 13. When the trigger valve 17 is supplied with pressurized air from the reservoir 11 and does not operate the trigger lever 18, the trigger valve 17 sends pressurized air to a main valve chamber 19 formed at the lower end of the main valve 13 to supply main air. The valve 13 is kept in the upper rest position. Therefore, pressurized air from the reservoir 11 is not supplied to the cylinder 3 and the piston 2 is not driven.
[0011]
The driving operation of the fastener driving machine 1 will be briefly described with reference to FIGS. 2A and 2B in addition to FIG. When the trigger lever 18 is pulled, the pressurized air in the main valve chamber 19 is discharged into the exhaust passage 26 provided in the valve housing 7 through the inside of the trigger valve 17, and a force for pushing the main valve 13 upward is generated. Disappears. On the other hand, since pressurized air is always supplied to the reservoir 11 and a downward force is constantly applied to the main valve 13, the main valve 13 is moved as indicated by an arrow 14 in FIGS. 1 and 2A. Then, move down. As a result, pressurized air is sent from the reservoir 11 to the cylinder 3 from the top (rear) side of the piston 2, and the piston 2 is rapidly moved downward inside the cylinder 3 by the pressurized air, and is connected to the piston 2. The driver 15 drives a fixing tool (not shown) such as a nail in the nose 21 into a driving target such as wood. In the position of FIG. 2A, the piston 2 and the driver 15 are at the bottom dead center. A return air chamber 22 is formed on the outer periphery of the cylinder 3 adjacent to the piston 2 at the bottom dead center, and pressurized air when the piston 2 descends is stored therein.
[0012]
When the operator releases the trigger lever 18 after the fastener is driven into the object to be driven, pressurized air is supplied from the reservoir 11 to the main valve chamber 19 through the trigger valve 17 as shown in FIG. 2B. Then, the main valve 13 is moved upward as indicated by an arrow 23. Thereby, the supply of the pressurized air from the reservoir 11 to the cylinder 3 is stopped. Also, when the main valve 13 moves near the upper stationary position (the position in FIG. 2B), the seal by the O-ring 24 is released, and the upper surface (the back surface) of the piston 2 is placed between the outside of the cylinder 3 and the inside of the main valve 13. A passage 25 for discharging the pressurized air supplied to the side ()) is formed. This passage 25 communicates with the return air chamber 22 and the sound reduction device 27 according to the present invention provided in the end portion 9 of the handle housing 7 through an exhaust passage 26 provided in the handle housing 7. At this time, since the main valve 13 has not completely returned to the upper stationary position, the communication with the exhaust passage 26 is blocked by the O-ring 28, and the pressurized air on the upper surface side of the piston 2 is returned to the return air chamber. Flows only to 22. When the main valve 13 further rises and the seal by the O-ring 28 is released and the pressurized air on the upper surface side of the piston 2 flows to the exhaust passage 26, the pressure on the upper surface side of the piston 2 decreases, so that the return air chamber 22 The pressurized air acts on the lower surface side of the piston 2 to rapidly return the piston 2 and the driver 15 to the rest position (that is, the top dead center). Due to this return, the pressurized air is rapidly discharged from the cylinder 3, and the discharged pressurized air passes through the passage 25 and the exhaust passage 26, and is further discharged to the atmosphere through the sound reduction device 27 according to the present invention, and is driven. To end.
[0013]
As shown in FIG. 1, after the driving is completed, the pressurized air discharged from the cylinder 3 passes through the passage 25 and the exhaust passage 26, and is installed at the outlet of the exhaust passage 26. It is discharged through 27. As shown in FIG. 1, the exhaust passage 26 is formed inside the handle housing 7 and separated from the reservoir 11 by a wall 29 and in parallel with the reservoir 11. The wall 29 is formed so that the pressurized air in the reservoir 11 does not leak into the exhaust passage 26, and keeps the reservoir 11 airtight. The exhaust passage 26 is connected to a pressurized air discharge passage 25 between the main valve 13 and the cylinder 3 in the tool housing 5 near the trigger valve 17, and the exhaust passage 26 is connected to the grip 6 of the handle housing 7. And towards the end portion 9 of the handle housing 7. A sound reduction device 27 is provided at an outlet 30 of the exhaust passage 26. The noise reduction device 27 reduces the exhaust noise when the pressurized air in the cylinder 3 is discharged to the atmosphere after the driving of the fastener driving machine 1 is completed.
[0014]
The sound reduction device 27 according to the present invention will be described in detail with reference to FIGS. 1 and 3 to 6. 3 is a sectional view of the handle housing 7 of FIG. 1 taken along the line III-III, and FIG. 4 is a sectional view of the handle housing 7 of FIG. 1 taken along the line IV-IV. FIG. 5 is an explanatory diagram schematically illustrating the exhaust flow of the sound reduction device 27, and FIG. 6 is an explanatory diagram of the exhaust flow. The sound reduction device 27 includes a pipe 34 arranged at the outlet 30 of the exhaust passage 26 so as to extend in the longitudinal direction of the exhaust passage 26. The pipe 34 has a cross section smaller than the cross section of the exhaust passage 26 and divides the exhaust passage 26 into an inner exhaust passage 31 and an outer exhaust passage 33 outside the inner exhaust passage 31. The pipe 34 has an exhaust hole 35. The exhaust hole 35 has a large number of exhaust holes 37 formed in the tube wall for discharging pressurized air from the inner exhaust passage 31 to the outside. The number and interval of the exhaust holes 37 of the exhaust hole 35 can be arbitrarily determined. The part of the exhaust passage 26 inside the handle housing 7 where the pipe 34 is provided is preferably formed as a cylindrical cavity. In this case, it is preferable to form a tapered tapered longitudinally extending rib 36 on the outer surface of the pipe 34 at the end side opposite to the exhaust hole 35. The pipe 34 having the tapered ribs 36 can be fitted and fixedly disposed in the exhaust passage of the pipe 34 simply by pushing the pipe 34 into the exhaust passage 26 of the cylindrical cavity. The number of the tapered ribs 36 may be one when used together with the non-tapered ribs. Otherwise, a plurality of tapered ribs 36 may be provided.
[0015]
The end portion 9 of the handle housing 7 largely surrounds the outer peripheral side of the exhaust hole 35 of the pipe 34 to form an exhaust chamber 39 around the exhaust hole 35, and the handle housing end portion 9 is The exhaust housing of the sound reduction device 27 is provided. The handle housing end portion 9 serving as an exhaust housing of the noise reduction device 27 is configured to receive exhaust hole exhaust discharged from the inner exhaust passage 31 through the exhaust hole 35 and exhaust that receives the outer exhaust passage exhaust from the outer exhaust passage 33. A chamber 39 is formed. Further, in the exhaust chamber 39, the first silencing member 41 is provided outside the exhaust hole 35 so that exhaust from the outer exhaust passage 33 (external exhaust passage exhaust) is guided to the outer peripheral surface of the exhaust hole 35 of the pipe 34. It is provided at intervals. The first silencing member 41 is disposed at a position where the outer exhaust passage exhaust gas sent from the outer exhaust passage 33 interferes with the exhaust hole exhaust gas exiting from the exhaust hole portion 35 to guide the exhaust hole exhaust gas at a reduced speed. You. More specifically, as shown in FIG. 5, the first noise reduction member 41 converts the outer exhaust passage exhaust 42 sent from the outer exhaust passage 33 into the exhaust hole exhaust 43 (the same as the inner exhaust passage exhaust) that exits from the exhaust hole 35. ) Is arranged at a position where it is guided so as to cause interference (collision in the orthogonal direction). Due to this interference, the speed of the exhaust hole portion exhaust 43 is reduced, and the speed of the outer exhaust passage exhaust 42 itself is also reduced. Accordingly, the flow of the pressurized exhaust air discharged from the exhaust passage 26 at a high speed is reduced to a low speed in the space between the exhaust hole 35 of the pipe 34 and the first noise reduction member 41, and the turbulence of the air flow is greatly reduced. It greatly contributes to sound. The first silencing member 41 is formed of a sound absorbing material that allows the exhaust hole portion exhaust 37 and the outer exhaust passage exhaust 42 to pass outside the first silencing member 41. For example, the first sound deadening member 41 can be made of a sound absorbing material made of an open-cell porous synthetic resin material.
[0016]
The space in the exhaust chamber 39, that is, the space between the exhaust hole 35 of the pipe 34 and the first silencing member 41, and the space outside the first silencing member 41, It becomes space to do. The discharged compressed air expands in the exhaust chamber 39, thereby slowing the exhaust flow. Thereby, the turbulence of the air flow can be further reduced, and the effect of reducing the exhaust noise is further enhanced. Therefore, it is preferable that the space between the exhaust hole 35 and the first noise reduction member 41 and the space outside the first noise reduction member 41 be large as long as the end portion of the handle housing 7 is not excessively large. For example, the first muffling member 41 has a length between the first muffling member 41 and the exhaust hole 35, which is a length that forms a space in which pressurized air rapidly discharged from the exhaust hole 35 can expand and decelerate. It is preferable to be away from the exhaust hole 35.
[0017]
In addition, the end portion 9 of the handle housing 7 that forms the exhaust housing is spaced apart from the first silencing member 41 by an interval that forms a space in which pressurized air can expand from the first silencing member 41. It is preferable that a second silencing member 45 made of the same sound absorbing material as the silencing member 41 is arranged. By providing the second silencing member 45, it is possible to reduce the noise by providing a space for further reducing the exhaust passing through the first silencing member 41, and to further reduce the reduced exhaust to the atmosphere. Further, as shown in FIG. 5, a part of the exhaust from the outer exhaust passage 33 (the outer exhaust passage exhaust 42) is provided between the first silencing member 41 and the end portion 9 of the handle housing 7 serving as the exhaust housing. It is preferable to provide a space 47 for directly discharging 46 into the exhaust chamber 39 outside the first silencing member 41 without passing through the first silencing member 41. It is well known that when the compressed air expands in a wide space, it takes heat, and when the exhaust gas that has passed through the first silencing member 41 expands in the exhaust chamber 39, it also takes heat and cools the surrounding area. I do. When working in the winter season, there is a risk of freezing due to cooling. Therefore, by directly discharging a part 46 of the exhaust gas from the outer exhaust passage 33 into the exhaust chamber 39 without passing through the first noise reduction member 41, cooling can be eased, and the first noise reduction member 41 is Freezing will not clog the exhaust. Further, the second noise reduction member 45 may form a part of the end portion 9 of the handle housing 7 as shown in FIG. 4 if it has sufficient rigidity. As shown in FIG. 5, a metal handle housing end portion 9 may be provided inside the handle housing end portion 9, and an exhaust hole may be provided in the handle housing portion outside the handle housing end portion 9.
[0018]
With reference to FIG. 6, the flow of exhaust air in the sound reduction device 27 of the fastener driving machine 1 will be described. The exhaust gas discharged from the cylinder 3 reaches the pipe 34 through the exhaust passage 26 at the grip 6 of the handle housing 7. The exhaust is divided into an inner exhaust passage 31 and an outer exhaust passage 33 by a pipe 34. The exhaust portion of the inner exhaust passage 31 is exhausted toward the first silencing member 41 through the exhaust hole 35. Since the exhaust gas from the outer exhaust passage 33 is sent so as to interfere therewith, the speed of the exhaust hole exhaust 43 is reduced, and the speed of the outer exhaust passage exhaust 42 itself is also reduced. In the space with the muffling member 41, the speed is reduced to greatly reduce the turbulence of the air flow, and greatly contribute to sound reduction. The exhaust gas expands through the first silencing member 41 to further reduce sound, and passes through the second silencing member 45 to be further reduced in sound and is exhausted to the atmosphere. The exhaust portion 46 passing through the space 47 reduces the cooling of the compressed air during expansion. Furthermore, even if the first silencing member 41 freezes, clogging of exhaust gas can be avoided. In the space between the exhaust hole and the first muffling member, the flow of the exhaust pressurized air flowing at a high speed due to the collision between the exhaust from the inner exhaust passage and the exhaust from the outer exhaust passage passing through the exhaust hole. Because the speed is reduced, the compressed air is discharged without requiring a large space for the expansion of the compressed air, without increasing the size of the fastener driving machine, and without relying solely on the sound absorbing action of the silencing member. Noise can be greatly reduced.
[0019]
The noise reduction device 27 is mounted near the end of the handle housing at the outlet of the exhaust passage extending from the grip to the end portion of the handle housing, and the handle housing portion at the end forms the exhaust housing. A high noise reduction effect can be obtained without increasing the size of the embedded device. The noise reduction device can be provided at another position. For example, the cap housing 49 above the cylinder 3 in FIG. 1 can be modified and provided at that portion.
[0020]
【The invention's effect】
According to the noise reduction device of the present invention, the outlet portion of the exhaust passage is divided into the inner exhaust passage and the outer outer exhaust passage by the pipe, and the inner exhaust passage exhaust is discharged to the exhaust chamber through the exhaust hole of the pipe. Since the exhaust from the outer exhaust passage is guided to the outer peripheral surface of the exhaust hole of the pipe and interferes with the exhaust from the exhaust hole, the speed of the exhaust from the exhaust hole is reduced, and The speed also decreases, and the flow of the exhaust pressurized air flowing through the exhaust passage at a high speed is reduced to a low speed in the space between the exhaust hole of the pipe and the first noise reduction member, so that the turbulence of the air flow is greatly reduced. The exhaust hole exhaust and the outer exhaust passage exhaust greatly contribute to sound reduction, and the exhaust flow in the space between the exhaust hole of the pipe and the first silencing member and the space outside the first silencing member, that is, the exhaust chamber. Inflated to slow down Rukoto can, further, exhaust noise is greatly reduced. Therefore, in the space between the exhaust hole of the pipe and the first muffling member, the exhaust from the inner exhaust passage and the exhaust from the outer exhaust passage that have passed through the exhaust hole collide with each other and the exhaust pressurization flowing at high speed. Since the air flow is slowed down, it does not require a large space such as a magazine, does not increase the size of the fastener driving machine, and does not rely only on the sound absorbing effect of the sound deadening member. Air noise can be greatly reduced.
[Brief description of the drawings]
FIG. 1 is a front sectional view of an embodiment of a fastener driving machine provided with a sound reduction device according to the present invention.
2A is a partial cross-sectional view of the fastener driving machine of FIG. 1 during a driving operation in which a piston is at a bottom dead center.
2B is a partial cross-sectional view of the fastener driving machine of FIG. 1 showing a driving end position where a piston has returned to a rest position.
FIG. 3 is a sectional view taken along line III-III of the handle housing 7 of FIG.
FIG. 4 is a cross-sectional view of the handle housing 7 of FIG. 1 taken along line IV-IV.
FIG. 5 is an explanatory diagram schematically illustrating an exhaust flow of the sound reduction device according to the present invention.
FIG. 6 is an explanatory diagram of a flow of exhaust gas.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Fixing tool driving machine 2 Piston 3 Cylinder 5 Tool housing 6 Grip 7 Handle housing 9 End part of handle housing (exhaust housing)
Reference Signs List 10 Pressurized air supply port 11 Reservoir 13 Main valve 15 Driver 17 Trigger valve 18 Trigger lever 19 Main valve chamber 21 Nose 22 Return air chamber 25 Pressurized air discharge passage 26 between cylinder and main valve Exhaust passage 27 Sound reduction device 29 Wall 30 Exhaust passage outlet 31 Inner exhaust passage 33 Outer exhaust passage 34 Pipe 35 Pipe exhaust hole 36 Rib 37 Exhaust hole 39 Exhaust chamber 41 First silencing member 42 Outer exhaust passage exhaust 43 Exhaust hole exhaust 45 Second silence Member 46 Exhaust portion 47 not passing through first silence member 47 Space through which exhaust portion does not pass through first silence member 49 Cap housing

Claims (6)

After sending pressurized air to the cylinder and driving a driver connected to the piston to drive a fastener such as a nail or a screw from the nose into the object to be driven, the piston and the driver are returned into the cylinder for return. A noise reduction device for reducing exhaust noise provided at an outlet of an exhaust passage of a pneumatic fastener driving machine that discharges pressurized air outside.
A longitudinal direction of the exhaust passage formed at an outlet portion of the exhaust passage and having a cross section smaller than a cross section of the exhaust passage and dividing the exhaust passage into an inner exhaust passage and an outer exhaust passage outside the inner exhaust passage. A pipe that extends to
The pipe has an exhaust hole portion in which a number of exhaust holes for discharging pressurized air from the inner exhaust passage are formed in a pipe wall,
An exhaust housing forming an exhaust chamber that receives exhaust from the inner exhaust passage through the exhaust hole and exhaust from the outer exhaust passage, surrounding an outlet portion of the exhaust passage;
The exhaust chamber is provided with a first silencing member at an interval outside the exhaust hole so as to guide exhaust gas from the outer exhaust passage to an outer peripheral surface of the exhaust hole of the pipe. The muffling member is arranged at a position for guiding the outer exhaust passage exhaust gas sent from the outer exhaust passage to interfere with the exhaust hole exhaust gas exiting from the exhaust hole portion to reduce the speed of the exhaust hole exhaust gas. A noise reduction device for driving a pneumatic fastener, wherein the exhaust hole portion exhaust and the outer exhaust passage exhaust are formed of a sound absorbing material that can pass outside the first silencing member. The apparatus of claim 1, wherein the fastener driving machine includes a tool housing including the piston, driver, and cylinder, and a handle housing integrally connected to the tool housing to form a grip for an operator. Wherein the exhaust passage is formed inside the handle housing so as to extend from the grip to an end of the handle housing, and the pipe is attached to the exhaust passage near the end of the handle housing, Apparatus, wherein an end portion of a handle housing forms the exhaust housing. 3. The device according to claim 1, wherein the first muffling member expands pressurized air rapidly discharged from the exhaust hole between the first muffling member and the exhaust hole of the pipe. 4. And a device that is separated from the exhaust hole by a length that forms a space that can be decelerated. The device according to any one of claims 1 to 3, wherein the exhaust housing passes through the first silencing member at a distance from the first silencing member further outside the first silencing member. Apparatus, characterized in that a second silencing member made of a sound absorbing material is arranged so as to provide a space for further deceleration of the exhaust gas to reduce the noise and discharge the reduced exhaust gas to the atmosphere. The device according to any one of claims 1 to 4, wherein a portion of the exhaust gas from the outer exhaust passage is not passed between the first silencing member and the exhaust housing. Is provided with a space for directly discharging the gas into the exhaust chamber outside the first silencing member, whereby the cooling caused by the expansion of the exhaust gas passing through the first silencing member in the exhaust chamber is reduced. And equipment. 3. The apparatus according to claim 2, wherein the exhaust passage inside the handle housing is formed as a cylindrical cavity, and an outer surface of the pipe is tapered so that an end side opposite to the exhaust hole portion tapers. A rib extending in the longitudinal direction is formed, and the pipe is fitted and fixedly arranged in the exhaust passage simply by pushing the pipe portion having the rib into the exhaust passage of the cylindrical cavity. And equipment.

Images