US20090000863A1

US20090000863A1 - Exhaust pipe

Info

Publication number: US20090000863A1
Application number: US12/215,337
Authority: US
Inventors: Li-Mei Kuo
Original assignee: Share Win Ind Co Ltd
Current assignee: Share Win Ind Co Ltd
Priority date: 2007-06-28
Filing date: 2008-06-26
Publication date: 2009-01-01

Abstract

An exhaust pipe comprises a pipe body formed therein with a silence chamber and an expansion chamber. A U-shaped gas inlet tube and a discharge tube are settled in the pipe body. The exhaust pipe facilitates smoothening waste gas discharge, generating appropriate exhaust back pressure and decreasing exhaust noise.

Description

BACKGROUND OF THE INVENTION

1. Technical Field
The present invention relates to an exhaust pipe through which a waste gas from a vehicle engine in operation is discharged.
2. Description of Related Art
A conventional exhaust pipe, as sown in FIG. 1, is a pipe body 10 inside divided into a first expansion chamber 13, a second expansion chamber 14, and a third expansion chamber 15 with two partitions 11. The second expansion chamber 14 is stuffed with a sound absorbing material 16. A gas inlet tube 17 passing through the first and second expansion chambers 13, 14 has a gas inlet 171 formed in a pipe wall of a first end of the pipe body 10 and a gas outlet 172 opened to the third expansion chamber 15. A gas outlet tube 18 passing through the second and third expansion chambers 14, 15 has a gas inlet 182 opened to the first expansion chamber 13 and a gas outlet 183 jutting out the pipe body 10 through the third expansion chamber 15. Besides, a connection tube 19 settled in the second expansion chamber 14 connects the first expansion chamber 13 and the third expansion chamber 15.
The gas inlet 171 of the gas inlet tube 17 is connected to a main discharge pipe of an engine, so that a waste gas of the engine enters the pipe body 10 of the exhaust pipe through the gas inlet 171 and goes into the third expansion chamber 15 by way of the gas outlet 172. Then the waste gas in the third expansion chamber 15 proceeds to the first expansion chamber 13 through the connection tube 19. Afterward, the waste gas in the first expansion chamber 13 is discharged outward the pipe body 10 through the gas outlet tube 18.
When gushed to the third expansion chamber 15 though the gas outlet 172 of the gas inlet tube 17 and when gushed to the first expansion chamber 13 from the third expansion chamber 15 through the connection tube 19, the waste gas directly impacts inner walls 105, 106 and causes high impact noises. Such gaseous impact also causes turbulent airflows in the first expansion chamber 13 and the third expansion chamber 15 and leads to hindered exhaust and instable back pressure, resulting in depressed torque output of the engine operating at low speed.

SUMMARY OF THE INVENTION

One primary objective of the present invention is to provide an exhaust pipe facilitating smooth waste gas discharge, appropriate exhaust back pressure for enhancing torque output of a vehicle engine operating at low speed and decrease of exhaust noise.
To achieve these effects, the disclosed exhaust pipe comprises:
a closed pipe body, in which a partition defines at least one expansion chamber and at least one silence chamber that is filled with a sound absorbing material, wherein the silence chamber has a capacity greater than a capacity of the expansion chamber and the partition is formed with a plurality of vents for gaseous convection;
a U-shaped gas inlet tube, having a U-shaped body with a gas inlet and a gas outlet at two ends thereof, wherein the U-shaped body is fixed in and axially parallel to the closed pipe body, a greater part of the U-shaped body being located in the silence chamber and wrapped by the sound absorbing material, the gas inlet being opened to a pipe wall of the closed pipe body while the gas outlet is located in the expansion chamber, and the part of the U-shaped body inside the silence chamber being formed with a plurality of noise elimination holes;
at least one discharge tube, having a tube body with a gas inlet and a gas outlet at two ends thereof, wherein the tube body is fixed in and axially parallel to the closed pipe body, a greater part of the tube body being located in the silence chamber and wrapped by the sound absorbing material, the gas inlet being located in the expansion chamber while the gas outlet is opened to the pipe wall of the closed pipe body, and the part of the tube body inside the silence chamber being formed with a plurality of noise elimination holes.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:

FIG. 1 is a cross-sectional view of a conventional exhaust pipe;

FIG. 2 is a cross-sectional view of a first embodiment of the present invention;

FIG. 3 is another cross-sectional view of the first embodiment taken along Line 3-3 of FIG. 2;

FIG. 4 is another cross-sectional view of the first embodiment taken along Line 4-4 of FIG. 2;

FIG. 5 is a cross-sectional view of a second embodiment of the present invention; and

FIG. 6 is a cross-sectional view of a third embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

While some preferred embodiments are provided hereinafter for illustrating the concept of the present invention as described above, it is to be understood that the components in these drawings are made for better explanation and need not to be made in scale. Besides, in the following description and the drawings, resemblances are indicated by the same numerals.
Please refer to FIGS. 2, 3 and 4 for the cross-sectional views of a first embodiment of the present invention. According to the present embodiment, the exhaust pipe of the present invention has a closed pipe body 20, a U-shaped gas inlet tube 25 and a discharge tube 27.
The closed pipe body 20 has a partition 21 therein defining an expansion chamber 22 and a silence chamber 23. The silence chamber 23 has a capacity greater than that of the expansion chamber 22. The partition 21 is formed with a plurality of vents 211 for gaseous convection. Furthermore, the silence chamber 23 is filled with a sound absorbing material 24.
The U-shaped gas inlet tube 25 has a U-shaped body 251 with a gas inlet 252 and a gas outlet 253 at two ends thereof. The U-shaped body 251 is fixed in the pipe body 20 and axially parallel to the pipe body 20. A greater part of the U-shaped body 251 is located in the silence chamber 23 and wrapped by the sound absorbing material 24. The gas inlet 252 is opened to a pipe wall of a first end 201 of the pipe body 20 while the gas outlet 253 is located in the expansion chamber 22. The part of the U-shaped body 251 inside the silence chamber 23 is formed with a plurality of noise elimination holes 26.
The discharge tube 27 has a tube body 271 with a gas inlet 272 and a gas outlet 273 at two ends thereof. The tube body 271 is fixed in the pipe body 20 and axially parallel to the pipe body 20. A greater part of the tube body 271 is located in the silence chamber 23 and wrapped by the sound absorbing material 24. The gas inlet 273 is located in the expansion chamber 22 while the gas outlet 273 is opened to the pipe wall of the first end 201 of the pipe body 20. The part of the tube body 271 inside the silence chamber 23 is formed with a plurality of noise elimination holes 28.
Please refer to FIG. 5 for the cross-sectional view of a second embodiment of the present invention. According to the present embodiment, the exhaust pipe of the present invention has a closed pipe body 20, a U-shaped gas inlet tube 25 and a discharge tube 30.
The closed pipe body 20 has a partition 21 therein defining an expansion chamber 22 and a silence chamber 23. The silence chamber 23 has a capacity greater than that of the expansion chamber 22. The partition 21 is formed with a plurality of vents 211 for gaseous convection. Furthermore, the silence chamber 23 is filled with a sound absorbing material 24.
The U-shaped gas inlet tube 25 has a U-shaped body 251 with a gas inlet 252 and a gas outlet 253 at two ends thereof. The U-shaped body 251 is fixed in the pipe body 20 and axially parallel to the pipe body 20. A greater part of the U-shaped body 251 is located in the silence chamber 23 and wrapped by the sound absorbing material 24. The gas inlet 252 is opened to a pipe wall of a first end 201 of the pipe body 20 while the gas outlet 253 is located in the expansion chamber 22. The part of the U-shaped body 251 inside the silence chamber 23 is formed with a plurality of noise elimination holes 26.
The discharge tube 30 has a straight body 301 with a gas inlet 302 formed on the straight body 301 and gas outlets 303 located at two ends of the straight body 301. The straight body 301 is fixed in the pipe body 20 and axially parallel to the pipe body 20. A greater part of the straight body 301 is located in the silence chamber 23 and wrapped by the sound absorbing material 24. The gas inlet 302 is located in the expansion chamber 22 while the gas outlets 303 are opened to pipe walls of the first end 201 and a second end 202 of the pipe body 20, respectively. The part of the straight body 301 inside the silence chamber 23 is formed with a plurality of noise elimination holes 28.
Please refer to FIG. 6 for the cross-sectional view of a third embodiment of the present invention. According to the present embodiment, the exhaust pipe of the present invention has a closed pipe body 20, a U-shaped gas inlet tube 25 and a discharge tube 30.
The closed pipe body 20 has two partitions 21 therein defining an expansion chamber 22 and two silence chambers 23. The expansion chamber 22 is sandwiched between the two silence chambers 23. Each of the silence chambers 23 has a capacity greater than that of the expansion chamber 22. The partition 21 is formed with a plurality of vents 211 for gaseous convection. Furthermore, the silence chambers 23 are each filled with a sound absorbing material 24.
The U-shaped gas inlet tube 25 has a U-shaped body 251 with a gas inlet 252 and a gas outlet 253 at two ends thereof. The U-shaped body 251 is fixed in the pipe body 20 and axially parallel to the pipe body 20. A greater part of the U-shaped body 251 is located in the silence chamber 23 and wrapped by the sound absorbing material 24. The gas inlet 252 is opened to a lateral wall 203 of the pipe body 20. The gas outlet 253 is located in the expansion chamber 22. The part of the U-shaped body 251 inside the silence chamber 23 is formed with a plurality of noise elimination holes 26.
The discharge tube 30 has a straight body 301, a gas inlet 302 formed on the straight body 301 and gas outlets 303 at two ends of the straight body 301. The straight body 301 is fixed in the pipe body 20 and axially parallel to the pipe body 20. A greater part of the straight body 301 is located in the silence chambers 23 and wrapped by the sound absorbing materials 24. The gas inlet 302 is located in the expansion chamber 22 while the gas outlets 303 are opened to pipe walls of a first end 201 and a second end 202 of the pipe body 20, respectively. The part of the straight body 301 inside the silence chamber 23 is formed with a plurality of noise elimination holes 28.
According to the foregoing embodiments, a waste gas of an engine enters the U-shaped body 251 through the gas inlet 252 of the U-shaped gas inlet tube 25 and is released to the expansion chamber 22 by way of the gas outlet 253 for decompression. Then the waste gas in the expansion chamber 22 enters the tube body 271 or 301 through the gas inlet 272 or 302 of the discharge tube 27 or 30. At last, the waste gas is discharged outward the pipe body 20 through the gas outlet(s) 273 or 303.
The U-shaped gas inlet tube 25 leads the waste gas to flow smoothly in the pipe body 20.
The U-shaped gas inlet tube 25 provides an extended path for the waste gas to flow in the pipe body 20 so that the noise elimination holes 26 or 28 and the sound absorbing material 24 serve to significantly reduce exhaust noise of the exhaust pipe. In addition, the discharge tube 27 or 30 also presents reduced exhaust noise in virtue of the noise elimination holes 28 or 31 and the sound absorbing material(s) 24.
The U-shaped gas inlet tube 25 defines a U-shaped flow path so that the flowing waste gas generates a back pressure that facilitates enhancing torque output of an engine operating at low speed. In cooperation with the U-shaped discharge tube 27, the back pressure can be further increased.
The vents 211 on the partition(s) 21 provide passageways communicating the waste gas in the silence chamber 23, 231, 232 and the expansion chamber 22 so as to prevent the silence chamber 23, 231, 232 or the expansion chamber 22 from getting overpressed.
Since the waste gas receives process of expansion, decompression and noise elimination in the expansion chamber 22 before entering the discharge tube 27 or 30 through the U-shaped gas inlet tube 25, the discharge tube 27 or 30 receives a reduced exhaust pressure, thereby allowing smoother and quieter exhaust. The expansion chamber 22 also provides an appropriate pressure to the U-shaped gas inlet tube 25 to modulate gaseous beck pressure in the U-shaped gas inlet tube 25.
The noise elimination holes 26 or 28 of the U-shaped gas inlet tube 25 and the noise elimination holes 28 or 31 of the discharge tube 27, 30 may be altered in amount, position, configuration, concentration, diameter and so on at manufacture so as to present different exhaust magnitudes and even different acoustic frequencies of exhaust.
Although the particular embodiments of the invention have been described in detail for purposes of illustration, it will be understood by one of ordinary skill in the art that numerous variations will be possible to the disclosed embodiments without going outside the scope of the invention as disclosed in the claims.

Claims

1. An exhaust pipe, comprising:

a closed pipe body, in which a partition defines at least one expansion chamber and at least one silence chamber that is filled with a sound absorbing material;

a U-shaped gas inlet tube, having a U-shaped body with a gas inlet and a gas outlet at two ends thereof, wherein the U-shaped body is fixed in and axially parallel to the closed tube, the gas inlet being opened to a pipe wall of the pipe body while the gas outlet is located in the expansion chamber, and the U-shaped body inside the silence chamber being wrapped by the sound absorbing material and formed with a plurality of noise elimination holes;

at least one discharge tube, having a tube body with a gas inlet and a gas outlet at two ends thereof, wherein the tube body is fixed in and axially parallel to the closed tube, a greater part of the tube body being located in the silence chamber and wrapped by the sound absorbing material, the gas inlet being located in the expansion chamber while the gas outlet is opened to the pipe wall of the pipe body, and the part of the tube body inside the silence chamber being formed with a plurality of noise elimination holes.

2. The exhaust pipe of claim 1, wherein, the silence chamber has a capacity greater than a capacity of the expansion chamber.

3. The exhaust pipe of claim 1, wherein, the partition is formed with a plurality of vents for gaseous convection.

4. The exhaust pipe of claim 1, wherein, the gas inlet of the U-shaped gas inlet tube is opened to the pipe wall of a first end of the pipe body.

5. The exhaust pipe of claim 4, wherein, the tube body of the discharge tube is in a U shape.

6. The exhaust pipe of claim 5, wherein, the gas outlet of the discharge tube is opened to the pipe wall of the first end of the pipe body.

7. The exhaust pipe of claim 4, wherein, the tube body of the discharge tube is in a straight shape.

8. The exhaust pipe of claim 7, wherein, the gas inlet of the discharge tube is located in the expansion chamber and two ends of the tube body is formed with a respective gas outlet in which the gas outlets are opened to the pipe wall of the first end and a pipe wall of a second end of the pipe body, respectively.

9. The exhaust pipe of claim 7, wherein, another partition in the pipe body defines another silence chamber that is also filled with a sound absorbing material, in which the expansion chamber is sandwiched between the two silence chambers.

10. The exhaust pipe of claim 9, wherein, the partition is formed with a plurality of vents for gaseous convection.

11. The exhaust pipe of claim 10, wherein, the gas inlet of the U-shaped air inlet tube is opened to a lateral wall of the pipe body.