JPH0720331Y2 - Silencer - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a silencer for an automobile.

[Prior Art] As a silencer for an automobile, for example, one disclosed in Japanese Utility Model Laid-Open No. 62-90916 is known.

FIG. 7 shows the silencer disclosed in this publication.
In the figure, reference numeral 1 is a cylindrical shell, the front and rear ends of which are closed by end plates 2 and 3. The inlet pipe 4 is attached to the upstream end plate 2. The inlet pipe 4 is open at its open end into the first expansion chamber 7 via two baffle plates 5 and 6. A pass tube 8 having small holes is attached to the two baffle plates 5 and 6. With this pass tube 8, the first expansion chamber 7 and the third expansion chamber 9
And are in communication. Also, two baffle plates 5,
A second expansion chamber 10 is formed between 6 and communicates with a small hole provided in the pass tube 8. The opening end of the outlet pipe 11 is open in the third expansion chamber. The outlet pipe 11 communicates with the atmosphere side via the three baffle plates 5, 6, 12 and the downstream end plate 3. A resonator pipe 14 is attached to the baffle plate 12, and a resonance chamber is provided between the baffle plate 12 and the end plate 3 on the downstream side.
Forming fifteen.

According to the muffler configured as described above, when exhaust gas flows in from the inlet pipe 4, the first expansion chamber 7, the second expansion chamber 10, and the third expansion chamber 9 mute by the expansion action, and then the outlet pipe. The sound wave having a predetermined low frequency can be resonantly attenuated in the resonance chamber 15 while being emitted to the atmosphere via 11.

However, this type of silencer diverts the exhaust gas in addition to the two end plates 2 and 3 for closing both ends of the shell 1 and the inlet pipe 4 and the outlet pipe 11 for introducing and discharging the exhaust gas. And a plurality of baffle plates 5, 6 and 12 for supporting the inlet pipe 4, the outlet pipe 11, the pass tube 8 and the resonator pipe 12, respectively. Moreover, each baffle plate 5,
The positions of the burring holes formed in 6 and 12 are different depending on the arrangement, and the same one is often unusable, which causes a problem that the number of constituent parts increases.

In addition, the expansion chambers 7,10,9 are arranged in the shell 1 so that the end plate 5,
Because it is formed by partitioning by 6,12,
Exhaust gas is silenced by a simple expansion action, and there has been a problem that it is difficult to meet the recent demand for actively silencing mid-high frequency components and taking sound quality countermeasures.

The present applicant has previously developed a silencer capable of solving such a conventional problem, and applied for this as Japanese Utility Model Application No. 63-103504.

8 and 9 show this muffler, in which reference numeral 20 indicates a shell.

The shell 20 has a tubular shape similar to the shell of a conventional silencer, and end plates 21 and 22 are attached to both ends thereof.

Inside this shell 20, there are two cylinders with a smaller diameter than the shell 20.
23, 24 are provided. The ends of the cylindrical bodies 23, 24 are in contact with the end plates 21, 22 and are closed.

The inlet pipe 25 is inserted into the one cylinder 23, the outlet pipe 26 is inserted into the other cylinder 24, and the inlet pipe 25 and the outlet pipe are inserted.
The end portion of 26 is the same as the cylindrical bodies 23 and 24, and the end plates 21 and 22
Is abutted against and blocked.

Further, a small hole 231 is bored on the upstream side of the peripheral surface of one cylinder body 23, and a small hole 241 is bored on the downstream side of the peripheral surface of the other cylinder body 24.

Further, on the peripheral surface of the inlet pipe 25, a small hole 251 is formed on the downstream side so as not to face the small hole 231 provided in the cylindrical body 23. Further, on the peripheral surface of the outlet pipe 26, a small hole 2 is provided on the upstream side so as not to face the small hole 241 provided in the cylindrical body 24.
61 is drilled.

Furthermore, since the shell 20 and the two cylindrical bodies 23 and 24 are coaxially arranged in contact with each other, they are
Two independent spaces 31 and 32 are formed.

With the muffler configured in this way, the engine starts,
When the exhaust gas flows in through the inlet pipe 25, the exhaust gas will pass through the small holes formed on the downstream side of the inlet pipe 25.
It is discharged into the space 30 formed between 251 and the cylindrical body 23. Then, the exhaust gas passes through this space 30 through the small holes 23 of the cylinder 23.
It is discharged from 1 into the spaces 31, 32 formed by the shell 20, the cylindrical body 23, and the cylindrical body 24. Further, the exhaust gas in the spaces 31, 32 moves to the portion of the cylindrical body 24 where the small hole 241 is formed, and flows into the cylindrical body 24 through the small hole 241. Furthermore, the exhaust gas moves through the space 32 formed between the tubular body 24 and the outlet pipe 26 to the portion of the outlet pipe 26 where the small hole 261 is formed, and the exhaust gas is discharged from the small hole 261 to the inside of the outlet pipe 26. And is discharged to the atmosphere through the outlet pipe 26.

In the silencer configured as described above, the two cylindrical bodies 23, 24
By partitioning the inside of the shell 20 by the, spaces 30, 31, 32 and 33 corresponding to four expansion chambers can be formed. That is, the baffle plate and the pass tube in the conventional silencer are unnecessary, and two cylindrical bodies having the same shape
23, 24, the inlet pipe 25, and the outlet pipe 26 can fulfill these roles. Therefore, the number of components is small and the assembly is easy.

In addition, a small hole 23 formed in the cylindrical body 23 and the inlet pipe 25.
Since 1 and 251, small holes 241 and 261 formed in the tubular body 24 and the outlet pipe 26 are arranged at different positions, the traveling distance of the exhaust gas becomes longer than that of the conventional silencer. Further, also in the spaces 31 and 32, since the small hole 241 of the cylindrical body 24 is formed in the direction opposite to the small hole 231 of the cylindrical body 23,
The exhaust gas again travels in the spaces 31 and 32, and further, the cylinder 2
When flowing in from the four small holes 241, they interfere with each other, and in particular, it is possible to reduce the sound pressure in the middle and high frequencies.

Further, the tubular body 23, the inlet pipe 25, the tubular body 24, and the outlet pipe 26 are all small holes 231, 25 formed in the peripheral surface.
Since the exhaust gas is expanded or contracted through 1,241,261, the rectifying action by the small holes is surely achieved, and there are advantages that secondary noise such as jet noise and air flow noise is less likely to occur, and pressure loss is less likely to occur.

Furthermore, since the acoustic circuit length from the inlet pipe 25 to the outlet pipe 26 is changed, it is possible to change the correspondence of the low frequency resonance system.

[Problems to be solved by the device]

However, in this silencer, the exhaust gas is expanded or contracted only by the small holes 231, 251, 241, 261 formed in the tubular body 23, the inlet pipe 25, the tubular body 24, and the outlet pipe 26, so that a sufficient silencing effect is not always required. However, there is a problem in that it is difficult to change the muffling characteristics depending on the type of engine.

The present invention has been made in order to solve such a conventional problem, and it is an object of the present invention to provide a silencer which can obtain a very high silencing effect and whose silencing characteristics can be relatively easily changed. Is.

[Means for Solving the Problems]

A muffler according to the present invention is a muffler in which an inlet pipe and an outlet pipe are inserted into a shell whose both ends are closed by end plates, wherein an inlet pipe or a small hole is formed in the shell. The two tubular bodies into which the outlet pipes are inserted are housed, the end portions of these tubular bodies are closed, and the outer peripheral surfaces of these tubular bodies are arranged on both opposite sides thereof at a predetermined distance from each other. A communicating portion is formed between the two, and further, small holes are bored in the outer peripheral surfaces of the cylindrical bodies opposite to each other with the communicating portion as a boundary.

[Action]

In the muffler of the present invention, when the engine is started and exhaust gas flows in through the inlet pipe, the exhaust gas forms a space between the small hole formed in the inlet pipe and the cylindrical body covering the inlet pipe. Is discharged inside. Then, the exhaust gas passes through this space and is discharged from a small hole of the cylindrical body covering the inlet pipe into one space formed by the shell and the two cylindrical bodies. Further, the exhaust gas in this one space passes through the communication part formed between the two cylinders and is discharged into the other space formed by the shell and the two cylinders, and the exhaust gas is discharged through the outlet pipe. It moves to the part where the small hole of the covering cylinder is bored, and flows into the cylinder covering the outlet pipe from this small hole. further,
Further, the exhaust gas moves in a space formed between the cylindrical body covering the outlet pipe and the outlet pipe to a portion where the small hole of the outlet pipe is formed, and flows into the outlet pipe from the small hole, It is released to the atmosphere through the outlet pipe.

〔Example〕

Hereinafter, the details of the present invention will be described with reference to the embodiments shown in the drawings.

1 to 5 show one embodiment of the silencer of the present invention, in which reference numeral 20 denotes a shell.

The shell 20 has a tubular shape similar to the shell of a conventional silencer, and end plates 21 and 22 are attached to both sides thereof.

Inside this shell 20, there are two cylinders with a smaller diameter than the shell 20.
23, 24 are provided. The ends of the cylindrical bodies 23, 24 are in contact with the end plates 21, 22 and are closed.

The inlet pipe 25 is inserted into the one cylinder 23, the outlet pipe 26 is inserted into the other cylinder 24, and the inlet pipe 25 and the outlet pipe are inserted.
The end portion of 26 is the same as the cylindrical bodies 23 and 24, and the end plates 21 and 22
Is abutted against and blocked.

Thus, in this embodiment, the outer peripheral surfaces of the shells 20, 24 are located on the inner peripheral surface of the shell 20, and the outer peripheral surfaces of these cylindrical bodies 23, 24 are On the opposite surface side thereof, a communication portion 29 is formed between the cylindrical bodies 23, 24 with a predetermined distance L therebetween.

In addition, a small hole 231 opening to the side of the one space 31 is bored on the upstream side on the peripheral surface of the one cylinder 23, and an opening to the other space 32 is formed on the peripheral surface of the other cylinder 24. A small hole 241 is formed on the downstream side.

Further, on the peripheral surface of the inlet pipe 25, a small hole 251 is formed on the downstream side so as not to face the small hole 231 provided in the cylindrical body 23. Further, on the peripheral surface of the outlet pipe 26, a small hole 2 is provided on the upstream side so as not to face the small hole 241 provided in the cylindrical body 24.
61 is drilled.

With the muffler configured in this way, the engine starts,
When the exhaust gas flows in through the inlet pipe 25, the exhaust gas will pass through the small holes formed on the downstream side of the inlet pipe 25.
It is discharged into the space 30 formed between 251 and the cylindrical body 23.

Then, the exhaust gas passes through the space 30 through the small holes 231 of the cylindrical body 23.
Is discharged into one space 31 formed by the shell 20, the cylindrical body 23, and the cylindrical body 24.

Further, the exhaust gas in the space 31 passes through the communication portion 29 formed between the cylindrical body 23 and the cylindrical body 24, flows into the other space 32, and the small hole 241 of the cylindrical body 24 is formed. It moves to the open part and flows into the cylindrical body 24 from the small hole 241.

Then, the exhaust gas passes through the space 32 formed between the tubular body 24 and the outlet pipe 26 through a small hole in the outlet pipe 26.
It moves to the site where 261 is drilled, flows into the outlet pipe 26 from the small hole 261 and is discharged to the atmosphere via the outlet pipe 26.

Then, in the silencer configured as above, the shell
The two tubular bodies 23, 24 into which the inlet pipe 25 or the outlet pipe 26 having the small hole 251 or 261 bored are inserted are housed in the housing 20, and the ends of the tubular bodies 23, 24 are closed. At the same time, the outer peripheral surfaces of these cylindrical bodies 23, 24 are arranged at a predetermined distance L on the opposing surface side, a communication portion 29 is formed between the cylindrical bodies 23, 24, and these cylindrical bodies are further formed. Small holes 231, 24 are formed on the outer peripheral surface on the opposite sides of the communication part 29 of 23, 24.
Since 1 is provided, a very high silencing effect can be obtained, and the silencing characteristics can be changed relatively easily.

That is, in the silencer configured as above, the cylindrical body 2
Since the communication part 29 is formed between the three and 24, it is possible to give a sufficient expansion contraction effect to the exhaust gas in this communication part 29, and it is possible to obtain a very high silencing effect.

In addition, in the muffler configured as described above,
Since the communication portion 29 is formed between the two, the expansion / contraction effect can be easily changed by changing the distance L between the cylindrical body 23 and the cylindrical body 24. It is possible to easily change the muffling characteristics.

Further, in the muffler configured as described above, the spaces 30, 31, 32 and 33 corresponding to the four expansion chambers can be formed by partitioning the inside of the shell 20 with the two cylindrical bodies 23 and 24. That is, the baffle plate and the pass tube in the conventional silencer are not required, and the same shape 2
These two cylinders 23, 24 and the inlet pipe 25, the outlet pipe 26 can eliminate these roles. Therefore, the number of components is small and the assembly is easy.

In addition, a small hole 23 formed in the cylindrical body 23 and the inlet pipe 25.
Since 1 and 251, small holes 241 and 261 formed in the tubular body 24 and the outlet pipe 26 are arranged at different positions, the traveling distance of the exhaust gas becomes longer than that of the conventional silencer. Further, also in the spaces 31 and 32, since the small hole 241 of the cylindrical body 24 is formed in the direction opposite to the small hole 231 of the cylindrical body 23,
The exhaust gas again travels in the spaces 31 and 32, and further, the cylinder 2
When flowing in from the four small holes 241, they interfere with each other, and in particular, it is possible to reduce the sound pressure in the middle and high frequencies.

Further, the tubular body 23, the inlet pipe 25, the tubular body 24, and the outlet pipe 26 are all small holes 231, 25 formed in the peripheral surface.
Since the exhaust gas is expanded or contracted through 1,241,261, it has the advantage that the rectifying action by the small holes is ensured, secondary noise such as jet noise and air flow noise is less likely to occur, and pressure loss is less likely to occur. .

FIG. 6 shows another embodiment of the silencer of the present invention.
In this example, the inlet pipe in the shell 20
The length of 25 and the outlet pipe 26 is shorter than that of the cylindrical bodies 23, 24, and the closing bodies 252, 262 are arranged at the ends. The inlet pipe 25 and the outlet pipe 26 are
It is supported by stays 253 and 263.

Even in the silencer configured as described above, it is possible to obtain substantially the same effect as that of the embodiment shown in FIG.

In the embodiment described above, the cylindrical body is provided on the inner peripheral surface of the shell 20.
Although the example in which the outer peripheral surfaces of 23 and 24 are brought into contact with each other has been described, the present invention is not limited to such an embodiment, and the shell 20
Needless to say, a gap may be formed between the cylindrical body 23 and the cylindrical body 24.

[Effect of device]

As described above, in the muffler of the present invention, two shells into which an inlet pipe or an outlet pipe having a small hole is inserted are housed in the shell, and the ends of these shells are closed. At the same time, the outer peripheral surfaces of these cylinders are arranged at a predetermined distance on the opposite surface side to form communication portions between the cylinders, and further, with the communication portions of these cylinders as boundaries. Since a small hole was drilled on the outer peripheral surface on the opposite side,
There is an advantage that a very high silencing effect can be obtained and the silencing characteristics can be changed relatively easily.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a silencer according to the present invention. FIG. 2 is a cross-sectional view of the central portion of FIG. FIG. 3 is a vertical cross-sectional view across the two cylinders of FIG. FIG. 4 is an explanatory view of the silencer of FIG. 1 viewed from above. FIG. 5 is an explanatory view of the silencer of FIG. 1 viewed from below. FIG. 6 is a perspective view showing another embodiment of the silencer according to the present invention. FIG. 7 is a vertical sectional view showing a conventional silencer. FIG. 8 is a perspective view showing a silencer previously filed by the applicant. FIG. 9 is a cross-sectional view of the central portion of FIG. [Explanation of symbols of main parts] 21,22 …… End plate 23,24 …… Cylinder 25 …… Inlet pipe 26 …… Outlet pipe 29 …… Communication part 31,32 …… Space 231,241,251,261 …… Small hole.

Claims (1)

[Scope of utility model registration request] 1. A muffler in which an inlet pipe and an outlet pipe are inserted into a shell whose both end openings are closed by end plates.
It accommodates two cylinders into which an inlet pipe or an outlet pipe having a small hole is inserted, closes the ends of these cylinders, and makes the outer peripheral surfaces of these cylinders the opposite surface side. In order to form a communicating portion between the cylinders, a small hole is formed in the outer peripheral surface on the opposite side with respect to the communicating portion of the cylinders. Silencer characterized by.