WO2016158891A1

WO2016158891A1 - Pneumatic tool provided with helmholtz silencing device

Info

Publication number: WO2016158891A1
Application number: PCT/JP2016/060001
Authority: WO
Inventors: 保全鈴木
Original assignee: 日東工器株式会社
Priority date: 2015-03-31
Filing date: 2016-03-29
Publication date: 2016-10-06
Also published as: CN107405766A; TWI601608B; TW201703944A; KR101959160B1; JP6382143B2; EP3278934B1; KR20170128466A; EP3278934A1; JP2016190288A; EP3278934A4; CN107405766B

Abstract

[Problem] To reduce noise from an exhaust path of a pneumatic tool. [Solution] In an exhaust path (30) in a housing (16) of a pneumatic tool (10), a silencing member (40) is provided along the longitudinal direction of the exhaust path such that the inside of the exhaust path is divided into: resonance chambers (46, 48) extending in the longitudinal direction of the exhaust path; and an exhaust passage (50) that extends in the longitudinal direction so as to be adjacent to the resonance chambers and separated from the resonance chambers, and receives exhaust from a motor chamber (20) and passes the exhaust to a downstream side outlet (30a). The silencing member (40) is provided with a hole (54) that connects the exhaust passage (50) and the resonance chambers (46, 48) to each other. The hole (54) and the resonance chambers (46, 48) form a silencing chamber using Helmholtz resonance.

Description

Pneumatic tool with Helmholtz silencer

The present invention relates to an air tool with a Helmholtz type silencer.

Air tools such as pneumatic belt type polishers and torque wrenches that operate using compressed air as a drive source connect an external air compressor to the air supply path of the tool housing and supply compressed air to the air motor. Exhaust gas is discharged to the outside through the exhaust passage of the housing.

Such air tools are required to reduce the noise accompanying the exhaust from the air motor, and various devices have been made. For example, in the air tool disclosed in Patent Document 1, a cylindrical member (silencer) extending along the exhaust passage is provided in the exhaust passage, and the exhaust passage is partitioned into a coaxial inner passage and an outer passage, A plurality of holes spaced in the circumferential direction are provided on the upstream side and the downstream side of the member, respectively, and a part of the exhaust gas flowing from the upstream side to the downstream side of the exhaust passage is divided (distributed) from the upstream hole to the outer passage. Then, the exhaust gas flowing through the inner passage from the downstream hole is merged, and a noise reduction effect is achieved by the frictional action between such a divided flow (dispersion) of the exhaust gas and the hole and the passage wall. In the air tool disclosed in Patent Document 2, glass wool (silencer) is filled in the exhaust passage to achieve a silencing effect.

In addition, as a technique for reducing noise generated by gas flowing through a flow path, Patent Document 3 discloses a resonance box that is communicated with the intake path from a side surface of the intake path through a small-diameter passage in order to reduce engine intake noise. A Helmholtz-type silencer formed by providing a (resonator) is disclosed.

Patent No. 3029092 Japanese Patent Laid-Open No. 5-138551 Japanese Patent Publication No. 3-4743

An object of the present invention is to provide an air tool equipped with a Helmholtz-type silencer having a simple structure that has not been conventionally available.

That is, the present invention
A housing including a motor chamber that houses an air motor, an air supply path that supplies compressed air to the motor chamber, and an exhaust path that allows exhaust from the motor chamber to be discharged from a downstream outlet to the outside;
A resonance chamber provided in the exhaust passage along the longitudinal direction of the exhaust passage and extending in the exhaust passage along the longitudinal direction of the exhaust passage, and the resonance chamber extending in the longitudinal direction adjacent to the resonance chamber. A silencing member that is partitioned from a chamber and receives an exhaust from the motor chamber and partitions the exhaust passage through the exhaust to the downstream outlet;
Provided is an air tool with a Helmholtz type silencer in which a hole for communicating the exhaust passage and the resonance chamber is provided in the silencer member, and the hole and the resonance chamber constitute a silencer chamber using Helmholtz resonance To do.

Since the air tool according to the present invention includes the Helmholtz-type silencer as described above, it is possible to suppress noise emitted to the outside through the exhaust passage.

In particular,
The exhaust passage extends linearly from the downstream outlet toward the motor chamber to the upstream side;
The muffling member can be inserted into the exhaust passage from the downstream outlet toward the upstream side where the motor chamber is located so that the exhaust passage is divided into the resonance chamber and the exhaust passage.

In one embodiment, the muffler member includes a plate-like partition wall that linearly extends from the downstream outlet toward the upstream side of the motor chamber in a state of being inserted into the exhaust passage. By engaging the periphery of the partition wall with the exhaust path wall surface defining the exhaust path, the inside of the exhaust path can be partitioned into the resonance chamber and the exhaust path. In this case, the hole is provided in the plate-like partition wall.

This makes it possible to equip the Helmholtz silencer with a simple structure.

More specifically, the silencer member has a plate-like second partition wall that is parallel to the plate-like partition wall with a space therebetween, and the silencer member is inserted into the exhaust passage. Thus, the peripheral edge of the second partition wall is engaged with the exhaust path wall surface defining the exhaust path, and the two partition walls are respectively between the exhaust path wall surface and the first partition wall. And the second resonance chamber, the exhaust passage is defined between the two partition walls, and the second resonance chamber and the exhaust passage communicate with each other through a hole formed in the second partition wall. Can be done.

More specifically, the first and second resonance chambers can be communicated with each other through a communication passage that crosses the exhaust passage.

Further, the sound deadening member may have a connecting wall that connects the downstream end portions of the two partition walls.

In this case, it is possible to provide a silencing material that passes the exhaust flowing from the upstream to the downstream and silences the space defined by the connecting wall and the two partition walls of the exhaust passage.

The housing may include an exhaust path pipe, and the exhaust path pipe may define the exhaust path.

The exhaust pipe can be removable from the housing.

Hereinafter, embodiments of an air tool according to the present invention will be described with reference to the accompanying drawings.

It is a side view of the belt type grinding tool as one embodiment of the air tool of the present invention. It is a top view of the belt type grinding tool of FIG. It is the III-III sectional view taken on the line of FIG. It is the IV-IV sectional view taken on the line of FIG. FIG. 2 is a perspective view of a muffling member that is inserted and set in the exhaust passage of the belt-type grinding tool of FIG.

A belt-type grinding tool 10 as an embodiment of the illustrated pneumatic tool according to the present invention includes an endless grinding belt 14 stretched around a pulley 12 set at a front end (left end in the drawing), and the endless grinding. The belt 14 is driven by an air motor 18 in the housing 16. The structural and functional relationship between the endless grinding belt 14 and the air motor 18 in the belt-type grinding tool is disclosed in, for example, Japanese Patent Application Laid-Open No. 2008-194769 and is well known to those skilled in the art. Detailed description is omitted.

The housing 16 has a cylindrical motor housing portion 22 having a motor chamber 20 that houses an air motor (vane motor) 18, and an air supply port 24 that communicates with the motor chamber 20 in the peripheral wall portion of the motor housing portion 22. And an exhaust port 26 is provided. The housing 16 further accommodates an air supply / exhaust pipe 32 provided with an air supply path 28 and an exhaust path 30 so that the air supply path 28 and the exhaust path 30 communicate with the air supply port 24 and the exhaust port 26, respectively. It has a handle portion 34 adapted to be set.

When grinding with the belt-type grinding tool (air tool) 10, the air supply path 28 is connected to an external air compressor, and the operation button 35 attached to the lower surface of the housing 16 is pushed to enter the air supply path 28. The provided on-off valve 38 is opened, and compressed air is supplied to the motor chamber 20 through the air supply path 28 and the air supply port 24 to drive the air motor 18. The exhaust from the motor chamber 20 is discharged to the outside through the exhaust port 26 and the exhaust path 30. At the right end of the exhaust passage 30 in the figure, an exhaust direction changing pipe member 36 is attached that can turn the exhaust gas in a desired direction by rotating about the longitudinal axis of the exhaust passage 30.

In the present invention, a Helmholtz type silencer (resonator) as described below is provided in the exhaust passage 30 of such a belt type grinding tool 10. The exhaust passage 30 extends substantially linearly from the outlet 30a at the right end toward the exhaust outlet 26, and a silencing member 40 as shown in FIG. 5 is inserted and fixed from the outlet 30a toward the exhaust outlet 26. The muffler member 40 extends in the longitudinal direction of the exhaust passage 30 and has a plate-like first partition wall 42 and second partition wall 44 that are spaced apart from each other in the transverse direction of the exhaust passage 30, and the first The upper connection wall 45a and the lower connection wall 45b connecting the partition wall 42 and the second partition wall 44 in the vicinity of the outlet 30a. The lower connection wall 45b is formed on the bottom surface 30c of the exhaust passage 30. It is supposed to touch. The first partition wall 42 and the second partition wall 44 define the exhaust passage 30 at the upper edge 42a, the lower edge 42b, the front edge 42c, and the upper edge 44a, the lower edge 44b, and the front edge 44c, respectively. The exhaust passage wall surface 30b is engaged in a substantially sealed state. By the first partition wall 42 and the second partition wall 44, the inside of the exhaust passage 30 is located between the left and right first resonance chambers 46 and second resonance chambers 48, and the resonance chambers, and the longitudinal direction of the exhaust passage 30. It extends in the direction and receives the exhaust from the motor chamber 20 and is partitioned into an exhaust passage 50 through which the exhaust passes to the outlet 30a of the exhaust passage 30. In the illustrated example, the muffling member 40 is provided with an inclined plate 52 that connects the lower part of the first partition wall 42 and the second partition wall 44 to the left end portion of the muffling member 40 in the drawing. A communication path 53 that connects the first resonance chamber 46 and the second resonance chamber 48 is formed between the lower surface 52a of the inclined plate 52 and the exhaust path wall surface 30b. Two resonance chambers 48 form a single resonance chamber. A single minute hole 54 is formed in each of the first partition wall 42 and the second partition wall 44, and the hole 54 and the resonance chamber form a Holz Helm type silencer using Helmholtz resonance. Yes.

The silencing member 40 can be taken in and out through the outlet 30a of the exhaust passage 30, and the first partition wall 42 and the second partition wall are provided at the lower connecting wall 45b at the right end of the silencing member 40. The sound deadening material 56 such as glass wool can be set so as to be sandwiched between 44. In the illustrated example, a claw 60 biased outward is provided at the right end portion of the first partition wall 42 and the second partition wall 44 so that the claw 60 penetrates the exhaust passage wall surface 30b. The sound deadening member 40 is fixed by being engaged with a hole (not shown) provided in. The silencing member 40 can be taken out from the exhaust passage 30 by pushing the claw 60 inward and removing it from the hole. Therefore, replacement of the sound deadening material 56 can be easily performed by extracting the sound deadening member 40 from the exhaust passage 30. In the illustrated example, ribs 58 are provided on the outer surfaces of the first partition wall 42 and the second partition wall 44, and these partition walls are supported so as to engage with the exhaust passage wall surface 30b.

Since the air tool 10 according to the present invention is provided with the Helmholtz silencer formed as described above, it is possible to attenuate noise transmitted to the outside from the exhaust passage. In principle, Helmholtz resonance is provided with one hole for one resonance chamber, but it has been confirmed that a silencing effect can be obtained even when a plurality of holes are provided.

As mentioned above, although embodiment which applied this invention to the belt type grinding tool was described, this invention is not limited to this, It applies widely to the air tool which exhausts from an air motor and is provided with the exhaust path. Can do.

Belt grinding tool 10
Endless grinding belt 14
Housing 16
Air motor 18
Motor room 20
Motor housing 22
Air supply port 24
Exhaust port 26
Air supply path 28
Exhaust passage 30
Exit 30a
Exhaust channel wall 30b
Air supply / exhaust pipe 32
Handle part 34
Operation button 35
Exhaust direction changing pipe member 36
On-off valve 38
Silencer 40
First partition wall 42
Upper edge 42a
Lower edge 42b
Front edge 42c
Second partition wall 44
Upper edge 44a
Lower edge 44b
Front edge 44c
Upper connecting wall 45a
Lower connecting wall 45b
First resonance chamber 46
Second resonance chamber 48
Exhaust passage 50
Inclined plate 52
Lower surface 52a
Communication passage 53
Hole 54
Sound deadening material 56
Rib 58
Nail 60

Claims

A housing including a motor chamber that houses an air motor, an air supply path that supplies compressed air to the motor chamber, and an exhaust path that allows exhaust from the motor chamber to be discharged from a downstream outlet to the outside;
A resonance chamber provided in the exhaust passage along the longitudinal direction of the exhaust passage and extending in the exhaust passage along the longitudinal direction of the exhaust passage, and the resonance chamber extending in the longitudinal direction adjacent to the resonance chamber. A silencing member that is partitioned from a chamber and receives an exhaust from the motor chamber and partitions the exhaust passage through the exhaust to the downstream outlet;
An air tool with a Helmholtz-type silencer, wherein the silencing member is provided with a hole communicating the exhaust passage and the resonance chamber, and the hole and the resonance chamber constitute a silencing chamber using Helmholtz resonance.
The exhaust passage extends linearly upstream from the downstream outlet toward the motor chamber;
The silencer is inserted into the exhaust passage from the downstream outlet toward the upstream side where the motor chamber is located, and the exhaust passage is divided into the resonance chamber and the exhaust passage. The air tool with the Helmholtz type silencer as described.
The sound deadening member is provided with a plate-like partition wall extending linearly from the downstream outlet toward the upstream side of the motor chamber in a state of being inserted into the exhaust passage, and the peripheral edge of the partition wall is 3. The exhaust passage is partitioned into the resonance chamber and the exhaust passage by engaging with an exhaust passage wall surface defining the exhaust passage, and the hole is provided in the partition wall. An air tool with a Helmholtz-type silencer as described in 1.
The silencer member has a plate-like second partition wall that is parallel to the plate-like partition wall, and the second silencer member is inserted into the exhaust passage. The periphery of the partition wall is engaged with the exhaust path wall surface defining the exhaust path, and the first and second resonance chambers are provided between the two partition walls and the exhaust path wall surface, respectively. And the exhaust passage is defined between the two partition walls, and the second resonance chamber and the exhaust passage are communicated with each other by a hole formed in the second partition wall. Item 4. A pneumatic tool with a Helmholtz-type silencer according to Item 3.
The air tool with a Helmholtz type silencer according to claim 4, wherein the first and second resonance chambers are communicated with each other by a communication passage that crosses the exhaust passage.
The air tool with a Helmholtz-type silencer according to claim 4 or 5, wherein the silencer member has a connecting wall that connects downstream ends of the two partition walls.
The Helmholtz-type sound deadening according to claim 6, wherein a sound deadening material is provided in the space defined by the connecting wall and the two partition walls of the exhaust passage to pass the exhaust flowing from upstream to downstream and to silence. Air tool with device.
The air tool with a Helmholtz type silencer according to any one of claims 1 to 7, wherein the housing includes an exhaust path pipe, and the exhaust path pipe defines the exhaust path.
The air tool with a Helmholtz-type silencer according to claim 8, wherein the exhaust pipe is removable from the housing.