JP2007032337A - Muffler - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To muffle an initial action diffusion part by immediately absorbing initial diffusing exhaust gas in a small diameter pipe 3 on a center line c at an inside of a muffler 2 provided in an exhaust pipe 1 for an internal combustion engine. <P>SOLUTION: In this muffler, diameter of the muffler 2 connected to the exhaust pipe 1 for the internal combustion engine on the common center line c is larger than that of the exhaust pipe 1, a small diameter pipe 3 of which both ends are blocked is arranged on the common center line c in the muffler 2, a space between the outer circumference of the small diameter pipe 3 and the inner circumference of the muffler 2 is blocked by a center partition plate 4, a plurality of suction permeation holes 5, 5' are bored on a side surface of the small diameter pipe 3 on an inlet 2' side of the partition plate 4, a plurality of discharge permeation holes 6, 6' are bored on an outlet 2" side of the partition plate 4, sound absorbing material 7 is put on an inner circumference surface of the muffler 2 between the partition plate 4 and the outlet 2" of the muffler 2. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a silencer in an exhaust pipe of an internal combustion engine.

  Conventionally, environmental impacts caused by noise while working on ships, around harbors, and when anchored, because the main sound source has become higher exhaust gas due to the smaller and higher output of the internal combustion engine, so a small and highly sound-absorbing silencer Has been demanded.

  In the conventional passive silencer, the diffusion type that considers the pressure loss due to passage resistance has a low noise reduction effect for the center sound, and it is necessary to change the fluid direction of the exhaust gas many times in order to mute the center sound. The total passage distance caused a pressure loss (for example, Patent Documents 1, 2, 3, and 4).

JP 7-42530 A JP-A-9-88548 JP 2003-328723 A JP 2004-156555 A

  It is an object of the present invention to mute the initial diffusion portion by immediately absorbing the initial diffusion exhaust in the small diameter pipe on the center line inside the muffler muffler provided in the exhaust pipe of the internal combustion engine.

In order to achieve the above object, the present invention firstly has a diameter of a muffler muffler connected to an exhaust pipe of an internal combustion engine on a common center line larger than that of the exhaust pipe. Are arranged on a common center line, the space between the outer periphery of the small-diameter tube and the inner periphery of the muffler is closed with a central partition plate, and a plurality of suction through holes are formed in the side surface of the small-diameter tube on the inlet side of the partition plate. A plurality of discharge through holes are formed on the outlet side of the partition plate, and a sound absorbing material is stretched on the inner peripheral surface of the silencer muffler between the partition plate and the outlet of the silencer muffler. Silencer,
Secondly, the outer periphery of the inlet-side closing plate of the both-end closed small-diameter pipe is fixed to the inner peripheral surface of the muffler, and a plurality of through holes are opened at symmetrical positions on the outer periphery of the closing plate. Silencer,
Thirdly, the silencer according to the first or second invention, wherein the plurality of suction through holes and the plurality of discharge through holes are arranged in an orderly manner,
Fourthly, the suction through hole is formed between the inlet side closing plate and the partition plate at a position perpendicular to the common center line and perpendicular to each other with an interval in the common center line direction. The silencer according to any one of the first to third inventions,
Fifthly, the discharge through hole is formed between the outlet side closing plate and the partition plate at a position perpendicular to the common center line and perpendicular to each other with an interval in the common center line direction. The silencer according to any one of the first to third inventions,
Consists of.

Therefore, the gas exhausted from the exhaust pipe enters the muffler muffler along the common center line, hits the inlet side closing plate, changes direction and hits the inner peripheral surface of the muffler,
It press-fits into the space between the small diameter tube and the muffler through a plurality of through holes, and the muffler emits a slight vibration sound.

Pressurized air in the space is orderly pressed into the short pipe through a plurality of suction through holes of the small-diameter short pipe, but does not vibrate the pipe wall of the small-diameter short pipe and abuts on the outlet side closing plate of the small-diameter pipe. Increase the entry pressure in the small diameter pipe,
The entering gas enters the outlet side space of the closing plate in the middle through the plurality of discharge through holes, the vibration of the exhaust gas is absorbed by the sound absorbing material, and the gas is silently discharged from the outlet to the outside of the muffler.

  Since the present invention is configured as described above, most of the vibration energy is generated by the small inner pipe of the muffler muffler without causing the exhaust pressure to vibrate the outer cylinder of the muffler muffler in the muffler muffler connected to the exhaust pipe of the internal combustion engine. So that a quiet muffler muffler can be obtained.

  A silencer muffler 2 having a diameter larger than the diameter of the exhaust pipe 1 is arranged on the common center line c in the exhaust pipe 1 of the internal combustion engine, and the outlet flange 1 'of the exhaust pipe 1 and the flange 2a of the inlet 2' of the muffler 2 are opposed to each other. And tighten them with bolts.

  The muffler muffler 2 has a cylindrical shape, and is provided with an outlet 2 ″, and a closed small-diameter pipe 3 sharing a center line c is disposed between the inlet 2 ′ and the outlet 2 ″. The inner periphery of the muffler 2 is connected and fixed with an annular central partition plate 4 to close the inlet side and outlet side spaces s and s.

The small-diameter pipe 3 is a quadrangular tube, and the outer periphery of the inlet-side closing plate 8 is fixed to the inner peripheral surface of the muffler 2, and a plurality of (four in FIG. 2) are symmetrically positioned on the outer periphery of the closing plate 8. Open semicircular arc-shaped holes 9, 9, 9, 9,
A diffusion chamber 10 is formed in the muffler 2 between the closing plate 8 and the inlet 2 '.

  A plurality of suction through holes 5, 5, 5 ′, 5 ′ are regularly formed in the small-diameter tube 3 (quadrangular tube) between the inlet-side closing plate 8 and the central partition plate 4, and the outlet-side closing plate 8 is formed. A plurality of discharge through holes 6, 6, 6 'and 6' are formed in an orderly manner in a small-diameter tube 3 (quadrangular tube) between 'and the central partition plate 4.

  A collecting chamber 11 leading to the outlet 2 ″ is interposed between the outlet side closing plate 8 ′ and the outlet 2 ″.

  A sound absorbing material 7 is stretched on the inner peripheral surface between the central partition plate 4 of the muffler muffler 2 and the outlet side end plate 2 b of the muffler 2.

  The suction through holes 5, 5 on the inlet 2 'side and the exhaust through holes 6, 6 on the partition plate 4 side are provided at the top and bottom shown in FIG. 1, and the suction through holes 5', 5 'on the partition plate 4 side and the outlet are provided. The discharge holes 6 'and 6' on the 2 "side are provided sideways as shown in Figs.

  That is, the exhaust gas that has entered from the exhaust pipe 1 through the inlet 2 ′ of the muffler muffler 2 diffuses in the diffusion chamber 10, and is separated and diffused evenly by the through holes 9, 9, 9, 9 at the outer periphery symmetrical position of the inlet side closing plate 8. Thus, the primary sound absorption is performed.

  Next, in the space s (collecting chamber) between the inlet side closing plate 8 and the partition plate 4, the suction is made into the small-diameter pipe 3 from the plurality (four) of suction through holes 5, 5, 5 ′, 5 ′. In this case, the first-sound-exhausted exhaust gas resonates and enters the small-diameter pipe 3 and is secondarily absorbed.

  The exhaust gas that has been secondarily absorbed is blocked by the outlet closing plate 8 ′ of the small-diameter pipe 3 and discharged from the plurality of (four) discharge through holes 6, 6, 6 ′, 6 ′. 7 is thirdarily absorbed (third-order sound absorption).

  The exhaust gas that is thirdarily absorbed is collectively decompressed in the collecting chamber 11 between the outlet side closing plate 8 ′ and the outlet 2 ″ of the small-diameter pipe 3 to reduce the sound pressure.

  As described above, the exhaust sound of the internal combustion engine diffuses in the diffusion chamber 10, is separated by the outer peripheral through hole of the inlet side closing plate 8, further resonates from the space s into the small diameter pipe 3, is absorbed by the sound absorbing material 7, and further gathers. In the state where the sound pressure is reduced in the chamber 11, it is discharged to the atmosphere from the outlet 2 ".

  The present invention repeats the exhaust sound emitted with the exhaust gas as described above by repeating the diffusion, separation, assembly, interference, and sound absorption at a short distance, and by making the exhaust flow close to a unidirectional flow with less backflow direction, Since the noise reduction effect is enhanced and the pressure loss due to passage resistance is minimized, the structure can be used not only for ships but also for exhaust pipes of large or small internal combustion engines in land transportation vehicles such as trucks and buses.

It is a longitudinal cross-sectional view which shows the silencer of this invention. (B) The figure is a longitudinal end view taken along the line BB, (b) The figure is taken along the line BB, (c) The figure is taken along the line CC, (d) The figure is D- (E) The figure is a longitudinal end view by the EE line, (f) The figure is the longitudinal end view by the FF line, (g) The figure is the longitudinal end view by the GG line, H) The figure is a longitudinal end view along the line H-H.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Exhaust pipe c Common center line 2 Silencer muffler 2 'Inlet 2 "Outlet 3 Both ends closed small diameter pipe 4 Central partition plate 5, 5' Suction through-hole 6, 6 'Discharge through-hole 7 Sound absorbing material 8 Inlet side closing plate 9 Through-hole

Claims (5)

The diameter of the muffler muffler connected to the exhaust pipe of the internal combustion engine on the common center line is larger than the exhaust pipe,
Both ends closed small-diameter pipes are arranged on a common center line inside the muffler muffler, and the space between the outer circumference of the small-diameter pipe and the inner circumference of the muffler is closed with a central partition plate,
A plurality of suction through holes are formed on the side surface of the small-diameter pipe on the inlet side of the partition plate, and a plurality of discharge through holes are formed on the outlet side of the partition plate,
A silencer in which a sound absorbing material is stretched on the inner peripheral surface of the muffler muffler between the partition plate and the muffler muffler outlet.   The silencer according to claim 1, wherein the outer periphery of the inlet-side closing plate of the both-end closed small-diameter pipe is fixed to the inner peripheral surface of the muffler, and a plurality of through holes are opened at symmetrical positions on the outer periphery of the closing plate.   The silencer according to claim 1 or 2, wherein the plurality of suction through holes and the plurality of discharge through holes are arranged in an orderly manner.   The suction through hole is formed between the inlet side closing plate and the partition plate at a position perpendicular to the common center line and perpendicular to each other with an interval in the common center line direction. A silencer as described in any of the above.   The discharge through hole is formed between the outlet side closing plate and the partition plate at a position orthogonal to the common center line and at a right angle to each other with an interval in the common center line direction. A silencer as described in any of the above.

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