1. A composite exhaust muffler for a motor vehicle is characterized by three sections of cylindrical pipe bodies which can be separately processed; the front cylindrical pipe body (1) is used for generating power and cooling tail gas; a spiral channel is processed on the outer surface of the middle cylindrical pipe body (8) to realize the function of resonance noise reduction; the rear cylindrical tube body (12) is provided with an infrasound source generator, so that interference noise elimination can be realized by utilizing the electric energy generated by the front cylindrical tube body, and self-powered active noise elimination can be realized.

2. The composite exhaust muffler for motor vehicles according to claim 1, wherein the central cylindrical pipe body (8) is formed with a through hole, and the outer circumferential wall thereof is formed with a spiral passage (10), the through hole being connected to the spiral passage (10); the outer side of the middle cylindrical pipe body (8) is provided with a middle cylindrical pipe shell (9); thus, the spiral passage (10) between the middle cylindrical tube body (8) and the middle cylindrical tube housing (9) is a closed gas passage.

3. The composite exhaust muffler for motor vehicles according to claim 1, wherein the rear tubular body (12) has an opening on one side of its wall surface, the opening being connected to a closed tubular body (13), the central axis of the closed tubular body (13) forming an obtuse angle with the direction of the exhaust flow; an infrasound source generator (14) is arranged in the closed tubular body (13), and the infrasound source generator (14) is connected with a signal control board (15) outside the closed tubular body (13); the signal control board (15) is fixed on the vehicle chassis and is supplied with electric energy by the thermoelectric conversion module (2).

Background

The silencer is an important link for controlling the noise of the vehicle, influences the dynamic property of the whole vehicle and influences the riding comfort of the vehicle.

The existing vehicle silencer is difficult to simultaneously consider the vehicle dynamic property and the riding comfort. Existing vehicle mufflers are largely classified into resistive mufflers and reactive mufflers. Resistive mufflers are muffled with sound absorbing materials. The reactive muffler is further divided into an expansion chamber type muffler, a resonance type muffler and an interference type muffler, wherein the interference type muffler achieves the muffling by means of the principle that sound wave interference is mutually counteracted. The interferometric muffler may be further classified into a passive muffler, a semi-active muffler and an active muffler. The tail gas of the engine has the characteristics of high temperature and wide exhaust noise bandwidth, in order to achieve the purpose of broadband noise elimination, most of the existing silencers are composite silencers, cover the working principles of expanding chamber type silencing, passive interference silencing and impedance silencing, generally adopt resistive materials to eliminate medium-high frequency noise, adopt an expanding cavity and a Helmholtz resonant cavity to eliminate medium-low frequency noise, and adopt interference silencing to eliminate noise with specific frequency. Even so, the existing muffler still has the problem of complicated structural design, and it often greatly increases the airflow resistance of the exhaust passage while eliminating noise, thereby reducing the output power of the engine and affecting the vehicle dynamic property.

In order to eliminate low-frequency noise, a large silencing structure is often added in the passive silencing technology, and a large space is occupied in practical application. Active muffler technology can selectively filter out noise of specific frequencies, but due to the high temperature characteristics of the exhaust gas, the life of the active muffler device is greatly affected.

In summary, the invention provides a muffler with simple structure, wide frequency, noise reduction and long service life, which is a problem to be solved urgently by those skilled in the art.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide the silencer which is simple in structure, wide in frequency, capable of reducing noise and long in service life.

In order to achieve the above object, the present composite exhaust muffler comprises: the device comprises a front cylindrical tube body (1), a thermoelectric conversion module (2), a cooling water device (3), an air inlet pipe (4), a first air pipe (5), a particle catcher (6), a second air pipe (7), a middle cylindrical tube body (8), a middle cylindrical tube shell (9), a spiral channel (10), a third air pipe (11), a rear cylindrical tube body (12), a closed tubular body (13), an infrasound source generator (14), a signal control panel (15) and an exhaust pipe (16).

The outer circumferential surface of the front cylindrical pipe body (1) covers the thermoelectric conversion module (2), the upper surface of the thermoelectric conversion module (2) is provided with a cooling water device (3), one side of the front cylindrical pipe body (1) is connected with an air inlet pipe (4), and the other side of the front cylindrical pipe body is connected with a first air pipe (5); the particle catcher (6) is arranged between the first vent pipe (5) and the second vent pipe (7); the second vent pipe (7) is inserted at one side of the middle cylindrical pipe body (8); a through hole is processed on the middle cylindrical pipe body (8), a spiral channel (10) is processed on the peripheral wall surface of the middle cylindrical pipe body, and the through hole is connected with the spiral channel (10); the outer side of the middle cylindrical pipe body (8) is provided with a middle cylindrical pipe shell (9); thus, the spiral channel (10) between the middle cylindrical tube body (8) and the middle cylindrical tube shell (9) is a closed gas channel; the other side of the middle cylindrical pipe body (8) is connected with a third vent pipe (11); the other side of the third air through pipe (11) is connected with the rear cylindrical pipe body (12); an opening is formed in one side of the wall surface of the rear cylindrical pipe body (12), the opening is connected with a closed tubular body (13), and the central axis of the closed tubular body (13) forms an obtuse angle with the air flow discharge direction; an infrasound source generator (14) is arranged in the closed tubular body (13), and the infrasound source generator (14) is connected with a signal control board (15) outside the closed tubular body (13); the signal control board (15) is fixed on the chassis of the vehicle and is provided with electric energy by the thermoelectric conversion module (2); the outside of the rear cylindrical pipe body (12) is connected to an exhaust pipe (16).

Automobile exhaust firstly enters the front cylindrical pipe body (1) from the air inlet pipe, and the temperature of the exhaust is very high at the moment, so that the temperature of the outer wall of the front cylindrical pipe body (1) is increased to form a hot end; the hot end is combined with the thermoelectric conversion module (2) and the cooling water device (3) to supply power for the signal control panel (14); the temperature of the air flow is reduced after the air flow passes through the front cylindrical pipe body (1) and the first vent pipe (5). After the gas flow passes through the particle catcher (6), the content of the particles in the tail gas is greatly reduced. When the air flow passes through the middle cylindrical tube body (8), the through holes and the spiral channels (10) on the middle cylindrical tube body (8) can generate Helmholtz resonance. By properly designing the number and length of the spiral channels (10), the helmholtz resonance will attenuate the medium and high frequency noise in the exhaust. When the air flow reaches the rear cylindrical pipe body (12) through the third vent pipe (11), the temperature of the air flow is greatly reduced. The infrasound source generator (14) located in the closed tubular body (13) emits sound with specific frequency under the control of the signal control panel (15) and the interference of the infrasound source generator and the low-frequency noise in the airflow is cancelled.

The invention is characterized in that three sections of cylindrical pipe bodies which can be separately processed are designed. The front cylindrical pipe body is used for generating power and cooling tail gas; a spiral channel is processed on the outer surface of the middle cylindrical pipe body, so that the function of resonance noise reduction is realized; the secondary sound source generator is arranged on the rear cylindrical pipe body, so that interference noise elimination can be realized by utilizing electric energy generated by the front cylindrical pipe body, and self-powered active noise elimination can be realized. The structure is simple to process, integrates active noise reduction, passive noise reduction and self-powered technology, can inhibit high-frequency noise, and can effectively reduce medium and low frequency noise.

The invention is further illustrated with reference to the following figures and examples.

Fig. 1 is a schematic longitudinal cross-section of the present invention.

In the figure, 1, a front cylindrical tube body, 2, a thermoelectric conversion module, 3, a cooling water device, 4, an air inlet pipe, 5, a first vent pipe, 6, a particle catcher, 7, a second vent pipe, 8, a middle cylindrical tube body, 9, a middle cylindrical tube shell, 10, a spiral channel, 11, a third vent pipe, 12, a rear cylindrical tube body, 13, a closed tubular body, 14, an infrasound source generator, 15, a signal control panel and 16, an exhaust pipe are arranged.

Specific example 1:

tail gas enters the front cylindrical pipe body (1) through the gas inlet pipe (4), and the front cylindrical pipe body (1) can be made of aluminum alloy materials with good heat conduction performance; the outer peripheral surface of the front cylindrical tube body (1) covers the thermoelectric conversion module (2), wherein the thermoelectric conversion module (2) can be made of lead telluride materials; the upper surface of the thermoelectric conversion module (2) is provided with a cooling water device (3), the cooling water device (3) is a copper thin water pipe, and the cooling water device is transversely and repeatedly arranged on the surface of the thermoelectric conversion module (2) in a U shape so as to increase the contact area between the cooling water device and the thermoelectric conversion module; the electric energy generated by the thermoelectric conversion module (2) is connected with the power end of the signal control panel (14) through a lead.

The exhaust gas enters the first vent pipe connection (5) through the other side of the front cylindrical pipe body (1) and then enters the particle trap (6), which will greatly reduce the particulate matter content in the exhaust gas and reduce the temperature of the exhaust gas.

The tail gas reaches the middle cylindrical pipe body (8) through the second vent pipe (7); the thickness of the inner wall of the middle cylindrical pipe body (8) is 1 mm-2 mm, 10-20 through holes are machined in the inner wall, and the diameter of each through hole is 3 mm-8 mm; 2-5 spiral channels (10) with different lengths are processed on the peripheral wall surface of the middle cylindrical pipe body (8), and the through holes are connected with the spiral channels (10); the width of the spiral channel (10) is 10 mm-15 mm, the depth is 3 mm-5 mm, and the length is 200 mm-400 mm; the outer side of the middle cylindrical pipe body (8) is provided with a middle cylindrical pipe shell (9) which is connected through a rivet; the other side of the middle cylindrical pipe body (8) is connected with a third vent pipe (11);

the other side of the third air through pipe (11) is connected with the rear cylindrical pipe body (12); an opening is formed in one side of the wall surface of the rear cylindrical pipe body (12), and the diameter of the opening is 60 mm; the opening is connected with a closed tubular body (13), and the central axis of the closed tubular body (13) forms an obtuse angle with the air flow discharge direction; an infrasound source generator (14) is arranged in the closed tubular body (13), and the infrasound source generator (14) is a piezoelectric loudspeaker; the infrasound source generator (14) is connected with a signal control panel (15) outside the closed tubular body (13) through a lead; the signal control board (15) is fixed on the chassis of the vehicle and is provided with electric energy by the thermoelectric conversion module (2); finally, the exhaust gas is discharged from the exhaust pipe (16).