JPH068719U - Exhaust silencer - Google Patents

Abstract

(57) [Summary] [Purpose] The handling of compressed air supply pipes and the operability of air tools are good, and their muffling performance is high. Moreover, overall pressure loss is low and high output air tools are provided. Provide an exhaust silencer that can be used with high efficiency. [Arrangement] A bellows-shaped exhaust pipe is coaxially arranged outside the compressed air supply pipe. The porous member is arranged so as to face the inner surface of the exhaust pipe. Exhaust gas freely passes through the space between the inner surface of the exhaust pipe and the porous member, but the noise component contained in the exhaust gas is efficiently attenuated by the combination of the inner surface of the exhaust pipe undulating in a bellows and the porous member.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an exhaust silencer such as an air drill, an air hammer, and an air driver, which is connected to a supply pipe for compressed air for operation and reduces exhaust noise of an air tool that exhausts used air into the atmosphere.

[0002]

[Prior art]

 A device for reducing the exhaust noise of an air tool, such as an air drill, an air hammer, and an air driver, which is connected to a supply line for compressed air for operation and discharges used air into the atmosphere, has been devised. No. 6918. Here, the exhaust pipe has a double structure with the supply pipe and extends close to the root of the supply pipe, and the exhaust port, which is essentially the largest noise source, is kept away from the worker. Further, a muffler filter made of a porous material is arranged at the connecting portion between the exhaust pipe and the air tool, and the muffler filter has a partition wall shape for separating the air tool side and the exhaust pipe side.

[0003]

[Problems to be solved by the device]

 In the above-mentioned exhaust silencer, the exhaust pipe itself does not have a silencing function, and the exhaust pipe connected to the air tool becomes long and heavy. On the other hand, if it is attempted to shorten the exhaust pipe to improve the handling of the supply pipe and the operability of the air tool, the exhaust port, which is essentially the largest noise source, approaches the worker and the noise experienced by the worker increases. There is a problem. Further, since the pressure loss due to the long exhaust pipe lowers the substantial supply pressure to the air tool, the output and efficiency of the air tool are lowered.

Further, since the sound deadening filter has a partition wall shape that separates the air tool side and the exhaust pipe side, if a material having a high sound deadening performance is used or the thickness is increased to improve the sound deadening performance. However, there is a problem in that the pressure loss due to the sound deadening filter is increased, while the sound deadening performance of the sound deadening filter is impaired if the pressure loss is reduced by reducing the thickness.

According to the present invention, the handling of the supply pipe and the operability of the air tool are good, the sound deadening performance is high, and the pressure loss is low, so that the air tool can be used with high output and high efficiency. The purpose is to provide an exhaust silencer.

[0006]

[Means for Solving the Problems]

 The exhaust silencer according to claim 1 is an exhaust silencer that reduces exhaust noise of an air tool that is connected to a supply pipe of compressed air for operation and discharges used air into the atmosphere. -An exhaust pipe having a corrugated inner surface and connected to an exhaust port of the air tool surrounding a side portion of the air tool; and a porous member attached to the supply pipe so as to face the inner surface of the exhaust pipe. , With.

An exhaust silencer according to a second aspect of the present invention is the exhaust silencer according to the first aspect, wherein the supply pipe is made of flexible pipe material, and the exhaust pipe is corrugated in a bellows shape and is comparable to the supply pipe. It is made of a pipe material having bending flexibility.

An exhaust silencer according to a third aspect is the exhaust silencer according to any one of the first and second aspects, wherein the porous member has a large number of small spaces divided by imperfect thin partition walls communicating with each other. It is made of a soft resin honeycomb material.

[0009]

[Action]

 In the exhaust silencer of claim 1, the compressed air for operation is supplied to the air tool through the supply pipe, and the compressed air is discharged to the atmosphere through the exhaust pipe while working in the air tool to reduce the pressure. The exhausted and used air (exhaust of the air tool) contains a high noise component at the stage of exiting the air tool exhaust port, and the noise component is, for example, of a high frequency accompanying the rotation of the air motor. It is a continuous roar. The exhaust pipe that surrounds the supply pipe communicates with the exhaust port of the air tool as it is, and the partition-shaped silencer filter that separates the air tool side and the exhaust pipe side is installed in the air tool. It does not need to be placed at the exhaust port.

The noise component contained in the exhaust of the air tool is effectively caused by the interaction between the corrugated inner surface of the exhaust pipe and the porous member attached to the supply pipe so as to face the inner surface. Attenuated. The facing interval between the corrugated inner surface and the porous member allows the relatively low speed exhaust of the air tool to pass through, but the pressure wave that is contained in the exhaust of the air tool and propagates and diffuses at high speed, that is, the noise component. It is not possible to pass the same facing distance by itself, such as explosions and shocks. The corrugated inner surface repeatedly reflects the pressure wave to repeatedly enter the porous member. On the other hand, a large number of internal spaces and throttle structures included in the porous member disperse, branch, interfere with each other, attenuate the noise components, and convert it into frictional heat of internal tissues for absorption.

In the exhaust silencer of the second aspect, since the supply pipe is a flexible pipe material, a flexible pipe material is also used for the exhaust pipe. The wall portion of the exhaust pipe is formed by corrugating in a bellows shape, has high rigidity in the diametrical direction, and flexibly deforms according to the bending condition of the supply pipe. Specific wave shapes of the bellows-like corrugation are sinusoidal, triangular, wavy with an appearance of stacked donuts, saw blades with steep slopes arranged on the side of the air, Etc. are available.

In the exhaust silencer of the third aspect, since the porous member is formed of the honeycomb material made of the soft resin, it can be deformed according to the pressing force and restores its original shape when the pressing force is removed. Compared to other types of porous members such as felt, cotton-like tissue, woven fabric, breathable sponge, millet-like tissue, artificial grass, etc., honeycomb material made of soft resin has a high porosity and is a partition wall. Since the structure is clear, it excels in the ability to disperse noise components and interfere with each other, so the same silencing performance can be achieved with a thinner thickness.

[0013]

【Example】

 An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic view of an air tool system incorporating the exhaust silencer of the embodiment, and FIG. 2 is a partial sectional view of the exhaust silencer of FIG. Here, an exhaust silencer that attenuates the noise contained in the exhaust of the air motor is shown, a bellows-shaped exhaust pipe that can be bent following a flexible supply pipe is used, and a soft material is used for the porous member. A resin honeycomb material is used.

In FIG. 1, an air tool 10 for rotating a rotary tool 7 communicates the compressed air supplied from the high-pressure portion 6a to the built-in air motor 6, while the used air is supplied to the low-pressure portion 6b. It is made to flow out and a rotational force is generated. The used air, that is, the exhaust air of the air motor 6 contains a continuous high-frequency explosion noise accompanying the rotation of the air motor. The low pressure portion 6b surrounding the high pressure portion 6a is provided with a ring-shaped built-in muffler-1 made of a felt material, but only the built-in muffler-1 is used because a low pressure loss one is used. Then, in particular, a sufficient silencing effect cannot be obtained in the middle to high frequencies.

The air tool 10 is connected to a valve 5 having a compressed air flow rate control function, an ON-OFF function, and the like, and an air supply portion 5a of the valve 5 has an air supply pipe (= about 1500 mm) (= The air hose 4) is connected, and the connector 8 is connected to the other end of the air hose 4. An exhaust hose 3 is connected to the exhaust part 5b of the valve 5 so as to surround the air hose 4. The exhaust hose 3 is a ready-made resin bellows hose having acid resistance and oil resistance. It has a length of 300 mm and is processed with the necessary ends on both ends. It has high rigidity in the diameter direction and can be bent freely in the axial direction.

The honeycomb resin molding cylinder 2 arranged between the air hose 4 and the exhaust hose 3 is attached to the air hose 4 such that one end thereof is sandwiched between the hose clip 2 a and the air hose 4. , Faces the bellows-shaped inner surface of the exhaust hose 3. The honeycomb resin molding cylinder 2 is molded from a material with acid resistance and oil resistance, which has a proven record in air cleaning equipment used in the manufacture of electronic parts, and is compression punched into a cylindrical shape from a block material with a thickness of 300 mm. is there. The honeycomb resin molding tube 2 has a structure in which a large number of small spaces divided by imperfect thin partition walls communicate with each other, and is deformable according to the pressing force, and when the pressing force is removed, the original shape is obtained. It has mechanical properties to restore to. Then, the inner surface of the exhaust hose 3 which undulates in a bellows shape facing the outer surface of the honeycomb resin molding cylinder 2 and the outer surface of the air hose 4 forms a multistage throttle structure connected in series, and during exhausting. It has the effect of repeatedly expanding and contracting the contained pressure wave component to attenuate it. The diameter of the inner side of the honeycomb resin molding cylinder 2 is set to be larger than the outer diameter of the air hose 4, and the air hose 4 is held loosely to improve its mountability and bendability.

In FIG. 2, the air supply portion 5a of the valve 5 is formed into a bamboo-like connection port into which the end portion 4a of the air hose 4 is forcibly inserted, and the end portion 4a of the air hose 4 is formed. Is tightened in such a manner that the honeycomb resin molding cylinder 2 is crushed by using a hose clip 2a having a screw formed inside thereof. On the other hand, the exhaust hose 3 surrounds the exhaust portion 5b of the valve 5 and is fitted and fixed to the corrugated side surface of the valve 5.

In the exhaust muffler of the air tool system configured as described above, an efficient silencing effect is achieved by the interaction between the bellows-shaped inner surface of the exhaust hose 3 and the honeycomb resin molding cylinder 2 facing the inner surface. Is obtained. According to the experiment, the noise level 83db of the A-band background noise 1m away from the conventional air tool system is improved by about 10% to 75db, and the conventional air tool system of the noise level 83db is improved. While having a pressure drop of 15%, the pressure drop in the air tool system of the example improved to a noise level of 75db was kept at 4% at the same supply pressure. Also, by selecting the material of the honeycomb resin molded tube 2, it has no clogging due to use, has oil resistance, acid resistance, and water resistance, and holds the diameter of the exhaust hose 3 below the diameter of the air tool. A compact and easy-to-handle air tool system in which the length of the exhaust hose 3 was shortened and the weight was significantly reduced was obtained.

[0020]

[Effect of device]

 According to the exhaust silencer of claim 1, since the space between the exhaust pipe and the porous member is open to the atmosphere, the pressure loss is small, and the silencer filter or the like provided in series in the exhaust passage is simple. Good. Also, the combination of the exhaust pipe and the porous member provides an effective noise reduction effect, so the required exhaust pipe length can be shortened, and the exhaust pipe length can be shortened so that the pressure loss is further reduced and the actual maximum Even if the exhaust port, which is a noise source, is set near the air tool, the working environment of the worker is not damaged.

According to the exhaust silencer of the second aspect, since the exhaust pipe freely bends following the supply pipe, the handleability of the air tool system is good. Further, since the inner surface of the exhaust pipe, which undulates in a bellows shape facing the porous member, forms a large number of throttling structures, the pressure wave component contained in the exhaust gas is repeatedly expanded and contracted to efficiently attenuate it. The sound deadening effect is further enhanced.

According to the exhaust silencer of the third aspect, since the honeycomb material made of the soft resin is selected, the exhaust silencer having the same silencing effect can be assembled into a compact one having a small diameter.

[Brief description of drawings]

FIG. 1 is a schematic view of an air tool system incorporating an exhaust silencer of an embodiment.

FIG. 2 is a partial cross-sectional view of the exhaust silencer of FIG.

[Explanation of symbols]

 1 Muffler 2 Honeycomb resin molding cylinder 3 Exhaust hose 4 Air hose 5 Valve 6 Air motor 7 Rotating tool 8 Connector

Claims (3)

[Scope of utility model registration request] 1. An exhaust silencer for reducing exhaust noise of an air tool which is connected to a supply pipe for operating compressed air and discharges used air into the atmosphere, wherein an air tool side portion of the supply pipe is provided. An exhaust pipe that is connected to the exhaust port of the air tool and that has an inner surface formed into a wavy shape, and a porous member that is attached to the supply pipe so as to face the inner surface of the exhaust pipe. A characteristic exhaust silencer. 2. The exhaust silencer according to claim 1, wherein the supply pipe is made of a flexible pipe material, and the exhaust pipe is
An exhaust silencer, which is made of a pipe material which is corrugated in a bellows shape and has bending flexibility comparable to that of the supply pipe. 3. The exhaust silencer according to claim 1, wherein the porous member is made of a soft resin honeycomb material in which a large number of small spaces divided by imperfect thin partition walls communicate with each other. Exhaust silencer characterized by consisting of.