JPH09119586A - Noise reduction member of silencer for pneumatic pressure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a noise reduction member of a silencer for pneumatic pressure into a small one by increasing a noise reduction efficiency while decreasing a resistance. SOLUTION: A noise reduction member 3 used for a silencer for pneumatic pressure is a cylindrical member which is made of a porous plastic with permeability and provided with an exhaust channel 8 in the axial direction. Also the noise reduction member 3 has small holes of 10 to 150μm in averaged diameter, and many grooves 9 on its outer surfaces 3a so that the area of the outer surfaces 3a is 1.05 to 40 times the area of the inner surfaces 3b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a muffling member of an air pressure silencer for attenuating exhaust noise of a pneumatic circuit.

[0002]

2. Description of the Related Art Pneumatic silencers, which are attached to an exhaust port such as a directional control valve used in an air pressure circuit and attenuate the exhaust noise, have various types such as resistance type, expansion type and resonance type. Although the type is known, the resistance type is common among them.

The resistance type silencer is generally made of various materials such as metal, paper, resin, etc., and the magnitude of the resistance thereof and the silencing efficiency are substantially proportional to each other. That is, the larger the resistance, the higher the muffling efficiency.

However, if a silencer having a large resistance is used, the resistance of the pneumatic circuit is increased, and the performance of the pneumatic circuit is often impaired. It is an object of the present invention to provide a muffling member for a pneumatic silencer, which can reduce the resistance while increasing the muffling efficiency and can be further downsized.

[0005]

The silencer member for a pneumatic silencer according to the present invention is used for a pneumatic silencer used for attenuating exhaust noise of a pneumatic circuit. This sound deadening member is provided with a tubular member made of porous plastic having air permeability and having an air passage in the axial direction. The cylindrical member has an average pore diameter of 10 to 1
The outer peripheral surface is uneven so that the area of the outer peripheral surface is 1.05 to 4.0 times the area of the inner peripheral surface in the range of 50 μm.

In such a sound deadening member, the exhaust gas from the pneumatic circuit flows into the air passage of the tubular member. The exhaust gas that has flowed into the ventilation passage is silenced by the resistance of the tubular member made of porous plastic. The cylindrical member that constitutes such a sound deadening member has the average pore diameter and the area relationship between the outer peripheral surface and the inner peripheral surface set as described above, and thus may be made of a porous plastic having a small resistance. The sound deadening efficiency is high.

In such a sound deadening member, the cylindrical member has, for example, an average pore diameter of 10 to 2 in a portion having a thickness of at least 50 μm from each of the outer peripheral surface and the inner peripheral surface.
00 μm and at least 1,00 near the center
It has a portion having an average pore diameter of 20 to 400 μm in a thickness range of 0 μm. For example, the average fine pore diameter of the central portion is at least 50 μm from each of the outer peripheral surface and the inner peripheral surface. It is 1.2 to 2.5 times the pore size.

Another muffling member according to the present invention is, like the above-mentioned muffling member, used in a silencer for air pressure used for attenuating exhaust noise of a pneumatic circuit. This sound deadening member is provided with a tubular member made of porous plastic having air permeability and having an air passage in the axial direction. The cylindrical member has an average pore diameter of 10 to 2 in a portion having a thickness of at least 50 μm from each of the outer peripheral surface and the inner peripheral surface.
00 μm and at least 1,00 near the center
It has a portion having an average pore diameter of 20 to 400 μm in a thickness range of 0 μm.

In such a sound deadening member, the exhaust gas from the pneumatic circuit flows into the ventilation passage of the tubular member. The exhaust gas that has flowed into the ventilation passage is silenced by the resistance of the tubular member made of porous plastic. The cylindrical member constituting such a sound deadening member has the average pore diameters in the vicinity of the outer peripheral surface, the inner peripheral surface, and the central portion set as described above, and therefore, it may be made of a porous plastic having a small resistance. The sound deadening efficiency is high.

[0010]

Embodiment 1 FIG. 1 is a partial sectional view of a pneumatic silencer to which an embodiment of the present invention is applied. In the figure, the silencer 1 for air pressure
Mainly includes a casing member 2 and a muffling member 3 housed in the casing member 2.

The casing member 2 is made of resin such as polyacetal resin or metal, and has a casing body 4 and a connecting member 5. The casing body 4 is a substantially tubular member, and has a left end surface 4a in the drawing closed and an opening 4b in the right end surface in the drawing. Further, on the outer circumference of the casing body 4, a large number of exhaust grooves 4c formed in the circumferential direction and communicating with the inside and the outside are formed in parallel.

The connecting member 5 is detachably attached to the right end surface of the casing body 4 in the drawing and has an opening 4b inside.
The flow path 6 corresponding to is formed in the axial direction. Also,
A threaded portion 7 for connection is formed on the outer peripheral surface of the tip portion of the connection member 5.

The sound deadening member 3 is a cylindrical porous body having air permeability made of a plastic material such as acrylic resin, polypropylene resin, polyethylene resin or polyacetal resin, and as shown in FIG. 2, exhaust gas extending in the axial direction. A channel 8 is formed in the center. Also, the sound deadening member 3
A large number of grooves 9 extending in the axial direction are formed on the outer peripheral surface 3a. With such a large number of grooves 9, the sound deadening member 3
Irregularities are formed on the outer peripheral surface 3a. The thickness of the sound deadening member 3 is usually 1.5 to 6 mm. If the thickness is less than 1.5 mm, the resistance of the sound deadening member 3 becomes small, and it is difficult to obtain a sufficient sound deadening effect. On the other hand, if it exceeds 6 mm, the resistance of the muffling member 3 becomes too large, which may impair the characteristics of the pneumatic circuit described later.

In the sound deadening member 3 as described above, the porous body forming the sound deadening member 3 has an average pore diameter of 10 to 150 μm.
Is set in the range. If the average pore diameter is less than 10 μm, the air permeability of the muffling member 3 is reduced, so that when the pneumatic silencer 1 is used in a pneumatic circuit, the resistance of the circuit is increased, so that the performance of the circuit is improved. It may damage. On the contrary, when the average pore diameter exceeds 150 μm,
Since the ventilation resistance of the muffling member 3 is reduced, the muffling efficiency of the pneumatic silencer 1 is reduced.

In the groove 9 formed on the outer peripheral surface 3a of the sound deadening member 3, the area of the outer peripheral surface 3a is 1.
It is provided so as to be 05 to 4.0 times. If this value is less than 1.05, the breathability of the muffling member 3 is reduced, and the same inconvenience as described above may occur. vice versa,
If it exceeds 4.0 times, the ventilation resistance of the muffling member 3 becomes small, so that there is the same problem as described above.

The above-described pneumatic silencer 1 is attached to, for example, an exhaust port such as a directional control valve used in a pneumatic circuit. Here, the pneumatic silencer 1 is fixed to the exhaust port by the screw portion 7 of the connection member 5.

Exhaust gas discharged from the exhaust port into the silencer 1 for air pressure accompanied by exhaust noise flows into the exhaust passage 8 of the silencer member 3 through the flow path 6 of the connecting member 5 and the opening 4b. The exhaust gas that has flowed into the exhaust passage 8 passes through the sound deadening member 3 made of a porous body, and is discharged to the outside from the groove 4c of the casing body 4. At this time, the exhaust noise is attenuated by the resistance of the muffling member 3.

In such a silencer for air pressure 1, since the average pore diameter of the muffling member 3 and the area relationship between the outer peripheral surface 3a and the inner peripheral surface 3b are set as described above, the resistance of the muffling member 3 is reduced. Although it is relatively small, the muffling efficiency is high. Therefore, the pneumatic silencer 1 does not impair the performance of the pneumatic circuit and can efficiently attenuate the exhaust noise. Further, since the muffling member 3 has high muffling efficiency,
Even if it is made compact, the effect of damping exhaust noise is good. Therefore, the pneumatic silencer 1 including such a silencing member 3 can be made smaller than the conventional one while maintaining the silencing characteristics.

Embodiment 2 In Embodiment 1, the unevenness is formed by providing a large number of grooves 9 extending in the axial direction on the outer peripheral surface 3a of the sound deadening member 3, but the present invention is not limited to this. That is, the unevenness of the outer peripheral surface 3a of the sound deadening member 3 may be formed by forming a large number of grooves extending in the circumferential direction of the outer peripheral surface 3a, or by forming a large number of dimples on the outer peripheral surface 3a. Good.

Embodiment 3 The muffling member 3 of Embodiment 1 may be constructed as follows while satisfying the above conditions. The muffling member 3 according to this embodiment is shown in FIG. Note that FIG. 3 corresponds to FIG.
FIG. 3 is a partial sectional view taken along line III-III of FIG. In the figure, the sound deadening member 3 has an average pore diameter of 10 to 200 μm in a thickness portion (portion indicated by m in the figure) of at least 50 μm from the outer peripheral surface 3a and the inner peripheral surface 3b, and the central portion, That is, in the portion other than the above-mentioned thickness portion (portion indicated by n in the figure), there is a portion having an average pore diameter of 20 to 400 μm in a thickness range of at least 1,000 μm. Further, compared with the average pore diameter of the thickness portion (portion indicated by m in the figure) of at least 100 μm from each of the outer peripheral surface 3a and the inner peripheral surface 3b, the central portion, that is, the portion other than the above-mentioned thickness portion (n in the figure, (Portion indicated by) is 1.2 to 2.
It is set to 5 times.

By constructing the muffling member 3 in this way, exhaust resistance can be further reduced and the exhaust noise can be more effectively silenced as compared with the case of the first embodiment.

Embodiment 4 A muffling member 30 according to this embodiment is shown in FIG. In the figure, the sound deadening member 30 is a cylindrical porous body having air permeability made of a plastic material such as an acrylic resin, a polypropylene resin, a polyethylene resin or a polyacetal resin, and an exhaust passage 80 extending in the axial direction is formed in the central portion. Has been done. It should be noted that the outer peripheral surface 30a of the sound deadening member 30 is not formed with irregularities as in the case of the first embodiment.
The thickness of the sound deadening member 30 is normally 1.5 to 6 mm, as in the case of the first embodiment.

In such a sound deadening member 30, as shown in FIG. 5, the average pore diameter is 10 to 200 μm from the outer peripheral surface 30a and the inner peripheral surface 30b at a thickness of at least 50 μm (portion indicated by o in the figure). And has a portion having an average pore diameter of 20 to 400 μm in a thickness range of at least 1,000 μm in a central portion, that is, a portion (a portion indicated by p in the figure) other than the above-mentioned thickness portion. ing.

According to the sound deadening member 30 of the present embodiment, the same effect as in the case of the first embodiment is obtained even though the outer peripheral surface is not provided with the unevenness as in the case of the first embodiment. can get.

[0025]

EFFECT OF THE INVENTION Since the silencer member of the pneumatic silencer according to the present invention has the average pore diameter of the tubular member and the area relationship between the outer peripheral surface and the inner peripheral surface set as described above, the tubular member is Even though it is made of porous plastic with low resistance, it has high sound deadening efficiency. Therefore, the sound deadening member can be made smaller while maintaining the same sound deadening efficiency as the conventional one.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of a pneumatic silencer to which an embodiment of the present invention is applied.

FIG. 2 is a perspective view of a sound deadening member according to the embodiment.

FIG. 3 is a partial sectional view taken along the line III-III in FIG. 2 in the case of the third embodiment.

FIG. 4 is a perspective view of a sound deadening member according to a fourth embodiment.

FIG. 5 is a partial sectional view taken along line VV of FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pneumatic silencer 2 Casing members 3 and 30 Silencers 3a and 30a Outer peripheral surfaces 3b and 30b Inner peripheral surface 6 Flow paths 8 and 80 Exhaust paths 9 Grooves

Claims (3)

[Claims] 1. A tubular member made of porous plastic having air permeability and having an air passage in the axial direction, wherein the tubular member has an average pore diameter in the range of 10 to 150 μm, The area is 1.05 of the inner peripheral surface area.
A silencer member for a pneumatic silencer, in which irregularities are provided on the outer peripheral surface so as to be 4.0 times. 2. The cylindrical member has an average pore diameter of 10 to 200 μm in a portion having a thickness of at least 50 μm from each of the outer peripheral surface and the inner peripheral surface, and at least 1,000 μm near the central portion. The average pore diameter in the thickness range has a portion of 20 to 400 μm, and the average pore diameter of the central portion is at least 50 μm from each of the outer peripheral surface and the inner peripheral surface. 1.
The sound deadening member for a pneumatic silencer according to claim 1, which has a power of 2 to 2.5 times. 3. A cylindrical member made of porous plastic having air permeability and having a ventilation path in the axial direction, wherein the cylindrical member has a thickness of at least 50 μm from each of the outer peripheral surface and the inner peripheral surface. Has an average pore size of 10 to 2
00 μm and at least 1,00 near the center
A silencer member for a pneumatic silencer, which has a portion having an average pore diameter of 20 to 400 μm in a thickness range of 0 μm.