JPH0649844Y2 - Exhaust silencer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an improvement of an exhaust silencer for an internal combustion engine.

(Prior Art) As shown in FIG. 2, a conventional exhaust silencer is provided with an expansion chamber 12 in an exhaust passage 11 through which exhaust gas flows, and directs the exhaust gas in the exhaust passage 11 toward the expansion chamber 12. A swirl motion generator 13 that causes a swirl motion in the exhaust gas is provided so as to flow away in the downstream direction of the exhaust passage 11, while a large number of through holes 14 are formed in the exhaust passage 11 and a sound absorbing material 15 is formed. And a holding material 16 is provided around (for example, Japanese Utility Model Laid-Open No. 63-140111).

(Problems to be solved by the invention) In the conventional exhaust silencer, when the exhaust gas flows through the exhaust passage 11, the exhaust gas is diffused by the whirlpool motion generating body 13, and the through hole 14, the sound absorbing material 15 and the holding It flows into the expansion chamber 12 through the material 16. However, when the exhaust gas pressure in the expansion chamber 12 becomes high, there is a problem that the noise reduction effect decreases because the gas flow flowing into the expansion chamber 12 through the through hole 14, the sound absorbing material 15, and the holding material 16 decreases. .

Therefore, the present invention has been made to solve the above problems, and provides an exhaust silencer that allows exhaust gas to flow through the expansion chamber.

(Means for Solving the Problems) In the present invention, an exhaust passage through which exhaust gas flows is provided with a cylindrical first expansion chamber and a frustoconical second expansion chamber which are filled with a large number of sound absorbing material spherical bodies. The first expansion chamber communicates with the exhaust passage and the second expansion chamber via the first and second small holes, and the outflow side opening of the exhaust passage is smaller than the inflow side opening.

(Operation) Most of the exhaust gas that has flowed into the exhaust passage goes straight through the exhaust passage, flows out to the second expansion chamber through the outlet side opening of the exhaust passage, and part of the exhaust gas passes through the first small hole. It flows into the first expansion chamber, comes into contact with the sound absorbing material spherical body, repeatedly flows between the spherical bodies while being dispersed, and the exhaust energy is absorbed,
Then, it flows into the second expansion chamber through the second small hole, merges with most of the exhaust gas, and then flows out.

(Embodiment) FIG. 1 is an embodiment of an exhaust silencer according to the present invention, in which an exhaust passage 1 is formed of a long tubular body having a large number of first small holes 2, and the outside of the exhaust passage 1 is formed. A first expansion chamber 3 having a cylindrical shape is provided, and a second expansion chamber 4 having a truncated cone shape is provided on the outflow side. A large number of second small holes 6 are formed in the partition wall 5, and the exhaust passage 1 and the first expansion chamber 3 are inserted through the first small holes 2.
And the first expansion chamber 3 and the second expansion chamber 4 communicate with each other through the second small hole 6, and a communication pipe 7 is interposed between the exhaust passage 1 and the second expansion chamber 4, The outlet side opening of the exhaust passage 1 is formed smaller than the inlet side opening. The exhaust passage 1 wall surface and the partition wall 5 surface on the side of the first expansion chamber 3 are covered with a mesh body 8 of stainless steel fiber, and the first expansion chamber 3 is filled with small ceramic balls 9.

Most of the exhaust gas flowing into the exhaust passage 1 is
While going straight inside, it flows out to the second expansion chamber 4 through the communication pipe 7, and at the same time, a part of the exhaust gas is discharged to the first small holes 2 and the mesh body 8.
And flows into the first expansion chamber 3. The exhaust gas flowing into the first expansion chamber 3 flows through the small holes 9 while repeating contact with the ceramic small balls 9 and repeating the dispersion, the exhaust energy is absorbed, and then from the second small hole 6 to the second expansion chamber 3. 4 and merges with most of the exhaust gas, and then flows out of the second expansion chamber 4.

(Effect of the Invention) According to the present invention, the exhaust energy can be efficiently absorbed by circulating the exhaust gas in the first expansion chamber filled with the sound absorbing spherical body, and at the same time, from the outer cylinder of the exhaust silencer. Since the radiated sound of is reduced, the silencing effect is significantly improved.

1 ... Exhaust passage, 2 ... First small hole, 3 ... First expansion chamber,
4 ... 2nd expansion chamber, 6 ... 2nd small hole, 9 ... Ceramic small ball.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG. 2 is a sectional view showing a conventional exhaust silencer.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor, Toyozo Kumagai, No. 1 Tenno, Takaoka-shinmachi, Toyota-shi, Aichi Pref. )

Claims (1)

[Scope of utility model registration request] 1. A first expansion chamber having a cylindrical shape and a second expansion chamber having a truncated cone shape, which are filled with a large number of spherical bodies made of a sound absorbing material, are provided side by side in an exhaust passage through which exhaust gas flows, and the first expansion chamber is exhausted. An exhaust silencer, characterized in that the exhaust passage is formed so as to communicate with the passage and the second expansion chamber via the first and second small holes, and the outlet side opening of the exhaust passage is formed smaller than the inlet side opening.