JP4620754B2 - Silencer - Google Patents

Description

  The present invention relates to a silencer that reduces sound by dispersing the sound emitted from the exhaust pipe in order to disperse the exhaust pipe.

A conventional silencer generates a very loud explosive sound when high temperature and high pressure exhaust gas is released as it is. The silencer is used there, but if you try to reduce the sound with this silencer, it will have a complicated structure, and if it is a complicated structure, resistance will be generated and the output will decrease. Therefore, various attempts have been made to reduce the sound while reducing the resistance.
JP-A-2005-240621 Japanese Patent Laid-Open No. 11-257047

  In the silencer of Patent Document 1, the exhaust pipe of the silencer body is composed of a small-diameter exhaust pipe and a large-diameter exhaust pipe, and the small-diameter exhaust pipe is accommodated in the large-diameter exhaust pipe. There has been one that can effectively absorb high-frequency airflow noise generated when jetting into a large-diameter exhaust pipe from the downstream end.

  The resonance-type silencer disclosed in Patent Document 2 has a resonance-type silencer that has a simple structure and improved noise reduction performance, increases the degree of freedom of frequency adjustment, and can easily set the frequency in a wide range.

  The conventional silencer has a complicated structure, and unless glass fiber is used inside the silencer body, the vibration of the exhaust is transmitted to the iron plate of the silencer body and becomes noise and leaks. And the sound enters the iron plate of the silencer body due to the vibration of the sound, and in order to eliminate the defect, the silencer body must be made of a thick object, and the glass fiber of the silencer absorbs the sound after all. It was an important material to do.

  Therefore, in the silencer of the present invention, the small-diameter pipe (2) is attached to the exhaust pipe (1), and the small-diameter pipe (2) bends the inside of the silencer body (4) in various ways to shift the exhaust time. That is, it is stronger in terms of strength if the exhaust gas is dispersed in the narrow exhaust pipe (1) rather than flowing high-temperature and high-pressure exhaust gas through the wide body (4). Therefore, the silencer which does not require glass fiber for a silencer main body (4) is provided.

In order to achieve the above object, the silencer of the present invention has a large number of small-diameter pipes (2) attached via a cap (3) to attach the small-diameter pipe (2) to the exhaust pipe (1).
The cap (3) has holes through which many small-diameter pipes (2) pass, and has a slanted surface in the engine direction to form a salami fir (11), which is attached through many small-diameter pipes (2) from the engine direction. The end of the small-diameter pipe (2) may be flared to form a flare portion (12) that fits into the salamomi portion (11) of the cap (3), and the portion may be welded to be reinforced.

The small-diameter pipe (2) bends in the silencer body (4) in various ways and has various lengths to shift the exhaust time, and also shift the location and direction of exhaust.
For this reason, the exhaust gas is dispersed and the iron plate of the main body (4) is not destroyed by the vibration of the exhaust gas, and no glass fiber is required inside the main body (4).
Further, the tail pipe (5) may be anywhere on the main body (4), and the outer pipe (6) of the tail pipe (5) is attached through the main body (4) so that exhaust gas passes through the small hole (7). Is moderately attached.
The inner pipe (8) is installed in the tail pipe (5), expanded to the diameter of the outer pipe (6), and attached by welding or the like inside the main body (4). Achieved.

By using the silencer of the present invention, the following effects are obtained.
(A) In the present invention, since the small-diameter pipe disperses the exhaust gas, no glass fiber is required as in the prior art.
(B) In the present invention, since the small-diameter pipe disperses the exhaust gas, the exhaust gas does not hit the iron plate of the main body, so that the iron plate can be made thin.
(C) Since the present invention uses a double pipe for the tail pipe, the exhaust gas does not flow backward at a low speed.
(D) The present invention is approximately half as heavy as a conventional silencer.

The silencer of the present invention is attached via a cap (3) to attach the small diameter pipe (2) to the exhaust pipe (1).
Since this cap (3) came up with the cap (3) at an important point of the present invention, I was convinced that it could be mass-produced.
A prototype of this silencer was made 30 years ago, but the cap (3) was not conceived, and the small diameter pipes (2) were welded together and welded to the exhaust pipe (1).
However, welding thin small-diameter pipes (2) causes a problem in strength because the welded part becomes thin, and the small-diameter pipe (2) is broken by the force of exhaust gas. High-temperature and high-pressure exhaust gas directly hit the main unit (4), and soot entered the rear iron plate of the silencer main unit (4).
As a result, the development of the silencer was abandoned, but there was a prospect for strength and mass production by interposing the cap (3).

  However, since the exhaust pipe (1) becomes narrow when the cap (3) is attached, the cap (3) is attached after the exhaust pipe (1) is enlarged through the reducer (9). The small-diameter pipe (2) is inserted therein, and the end of the small-diameter pipe (2) is expanded with a flare to form a flare portion (12), and is accommodated in the salamomi portion (11) of the cap (3), Stop by caulking or welding.

The small-diameter pipe (2) bends in the silencer body (4) in various ways and has various lengths to shift the exhaust time and change the location and direction of the exhaust gas.
First, the small-diameter pipe (2a) is attached to the center and makes the first exhaust gas explosion sound.
Next, the small-diameter pipe (2b) is a little longer, so that the exhaust gas emits an explosion toward the side surface of the main body (4) with a slight delay. The small diameter pipe (2d) is slightly longer than the small diameter pipe (2a) and is bent, and there is resistance, so about four are preferable.

  Next, the small-diameter pipe (2c) explodes further later, and the small-diameter pipe (2d) explodes further later on the tail pipe (5) side of the main body (4). It's okay. The small-diameter pipe (2e) makes a large detour from the opposite side of the cap (3), and the last explosion occurs far away from the front tail pipe (5), but the resistance is the highest, and the bend is also bent 180 degrees. Therefore, eight or more small-diameter pipes (2e) are necessary.

  Then, it is ideal that the small-diameter pipe (2a) explodes for a second time a little later, but when calculated, it requires 20 times the capacity of a commercially available silencer, which is not possible in practice. The tail pipe (5) may be freely attached since it is not related to the present invention. However, the tail pipe (5) is a double pipe and the outer pipe (6) is a small hole in the silencer body (4). (7) is opened moderately, and the inner pipe (8) is widened and welded to the outer pipe (6) in the main body (4), so that when the engine is running at a low speed, the exhaust gas flows into the tail pipe (5 ), The sound is quiet.

Embodiments of the present invention will be described below with reference to the drawings.
The schematic diagram of FIG. 1 is a cross section cut across the present invention. The arrows indicate the strength of exhaust gas and the place where it exits regardless of time, and the silencer was designed for a 1200 cc engine. The exhaust pipe (1) has a diameter of 34 mm, and the small-diameter pipe (2) is attached with a cap (3) in order to attach a large number of copper pipes with a diameter of 8 mm.
However, since the exhaust pipe (1) becomes narrow when the cap (3) is attached, the capacity of the exhaust pipe (1) is about 900 square millimeters, and is increased to 60 mm in diameter through the reducer (9) and then the cap ( 3) is attached, and the cap (3) is formed by cutting a 5 mm steel plate into a diameter of 58 mm and then making a hole as shown in FIG. The hole is 8 mm, 28 holes are drilled, the inner capacity of the copper tube is 6 mm in diameter, the capacity is 28 square millimeters and the 200 square millimeter capacity is small, so 25 small holes (10) with a diameter of 3 mm, 25 I drilled holes everywhere and put the jars together.

The cap (3) has holes for inserting a number of small-diameter pipes (2). The engine side of the cap (3) is 10mm and the salamomi part (11) is salamomied. FIG. 3 is a cross-sectional view of FIG. 3, and FIG. 4 is an enlarged view of the cross-sectional view of FIG. 3. The small-diameter pipe (2) bends in the silencer body (4) in various ways and has various lengths to shift the exhaust time, and also shifts the location and direction of exhaust.
The schematic diagram in FIG. 5 shows a white arrow where the exhaust gas first reaches the rear part of the exhaust pipe (1). Leaks and this is the standard. In FIG. 6, the small-diameter pipe (2a) is attached in the center, and the first exhaust gas explosion sound is 0.00016 seconds later. The arrow represents the exhaust gas, and the other exhaust gas is in the small diameter pipe (2) when it exits from the small diameter pipe (2a).

Next, after 0.00027 seconds after the small-diameter pipe (2b) of FIG. 7 is slightly delayed by a little longer, an explosion of exhaust gas is made toward the side surface of the main body (4). It is the small-diameter pipe (2b) that is where the arrows come out from the small-diameter pipe (2), and there are two in this figure.
Next, an arrow indicates where the exhaust gas is emitted from the small-diameter pipe (2c) in FIG. 8 and makes an explosion sound. After a delay of 0.0005 seconds, the small-diameter pipe (2d) in FIG. It showed an explosion after a delay of 0.0008 seconds on the tail pipe (5) side of the main body (4).
An arrow indicates that the small-diameter pipe (2e) in FIG. 10 makes a large detour from the opposite side of the cap (3) and is far from the front tail pipe (5), and finally explodes after 0.0012 seconds. It was.

  Then, it is ideal that a small explosion (10) will explode a second time after 0.0015 seconds, but it is an engine that rotates 40000 in 4 cycles per minute with 4 cylinders, but there is no engine with such a high speed However, since the rotation speed changes, the performance of the silencer also changes. Therefore, in order to mute the sound of the silencer, it is easy to have a capacity of 20 times.

  The tail pipe (5) may be anywhere on the main body (4), and the outer pipe (6) of the tail pipe (5) is installed through the main body (4), and exhaust gas passes through so that the small hole (7) is moderate. It is attached to. If the tail pipe (5) is not a double pipe, exhaust gas will be exhausted by idling, and then the vacuum will be applied and the air will flow backwards. Thus, resistance to prevent backflow was given.

  In the silencer of the present invention, the exhaust sound of the rock drill machine is a thing that is intermittently exhausted using compressed air, so if the intermittent exhaust is silenced according to the present invention, glass fiber is not used in the silencer body. A light silencer can be provided.

The figure is a schematic diagram of a silencer. The figure is a rear view as seen from the back of the cap. The figure is a cross-sectional view showing attachment of a small-diameter pipe. FIG. 4 is an enlarged view of FIG. 3. The figure is a schematic diagram of the silencer, where the exhaust gas has entered the exhaust pipe. The figure is a schematic view of the silencer, where exhaust gas is discharged from the small diameter pipe (2a). The figure is a schematic diagram of the silencer, where the exhaust gas exits from the small diameter pipe (2b). The figure is a schematic diagram of the silencer, where the exhaust gas exits from the small diameter pipe (2c). The figure is a schematic diagram of the silencer, where the exhaust gas comes out from the small diameter pipe (2d). The figure is a schematic diagram of the silencer, where the exhaust gas exits from the small diameter pipe (2e).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Exhaust pipe 2 Small diameter pipe 2a Small diameter pipe 2b Small diameter pipe 2c Small diameter pipe 2d Small diameter pipe 2e Small diameter pipe 3 Cap 4 Body 5 Tail pipe 6 Outer pipe 7 Small hole 8 Inner pipe 9 Reducer 10 Small hole

Claims (1)

A large number of small diameter pipes (2) are attached to the exhaust pipe (1) through caps (3),
The small-diameter pipe (2) can be muffled by bending the silencer body (4) in various ways, varying the length of the exhaust gas from the exhaust gas emission time, and shifting the direction and direction of the exhaust gas emission. Engine silencer characterized by

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