Exhaust noise elimination system for vehicle and vehicle
By integrating the gas purification chamber into the silencing chamber, an integrated exhaust silencing system is formed, which solves the problem of the exhaust system occupying a large chassis space, achieves higher space utilization and lower back pressure, improves engine performance and reduces fuel consumption.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-22
- Publication Date
- 2026-03-27
AI Technical Summary
In the existing technology, the exhaust system of gasoline engine hybrid or range-extended vehicles occupies a large amount of chassis space, resulting in low chassis space utilization, increased fluid resistance, increased back pressure, and affecting engine power and fuel consumption.
By integrating the gas purification chamber into the anechoic chamber, a highly integrated exhaust silencing system is formed. The exhaust gas directly enters the gas purification chamber for purification, and the cleaned gas enters the anechoic chamber for noise reduction before finally being discharged from the second exhaust pipe. This reduces the layout of exhaust pipes and improves space utilization.
The reduced exhaust flow path decreased the impact of heat on chassis components, lowered back pressure, increased engine power, and reduced fuel consumption.
Smart Images
Figure CN224049288U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the exhaust technology field of internal combustion engine, and particularly relates to an exhaust silencing system for a vehicle and the vehicle. BACKGROUND
[0002] The exhaust silencing system of the automobile is mainly used for reducing the exhaust noise of the automobile engine and safely discharging the high-temperature exhaust gas, so as to meet the noise regulation requirements of the vehicle.
[0003] In the prior art, for a gasoline engine hybrid vehicle or a range extending vehicle, the silencer and the exhaust pipe are usually arranged between the battery pack and the vehicle body threshold beam. Meanwhile, the exhaust system is arranged from the engine compartment to the tail of the vehicle, the exhaust pipe extends longitudinally, and occupies a large amount of space of the chassis, which leads to low utilization of the space of the chassis. In addition, since the battery pack, the fuel tank, the wire harness, the water pipe and other parts are arranged on the vehicle body chassis, the arrangement of the exhaust pipe is affected by the arrangement space limitation of the battery pack, the fuel tank, the wire harness, the water pipe and other parts, which makes the arrangement complex, significantly increases the fluid resistance, increases the exhaust back pressure, and affects the power and the torque of the engine, and affects the fuel consumption of the engine. CONTENT OF THE UTILITY MODEL
[0004] The present application provides an exhaust silencing system for a vehicle and the vehicle, which reduces the arrangement of the exhaust pipe, improves the utilization of the space of the chassis, reduces the back pressure, improves the power of the engine, and reduces the fuel consumption.
[0005] In order to achieve the above-mentioned purpose, the main technical scheme adopted by the present application includes:
[0006] In a first aspect, the exhaust silencing system includes a silencing chamber, a gas purification chamber, a gas purification device and a second exhaust pipe. The silencing chamber is internally provided with at least one silencing cavity for noise reduction. The gas purification chamber is built-in in the silencing chamber, the gas purification chamber is provided with an inlet pipe and a first exhaust pipe, the inlet pipe is used for receiving the exhaust gas generated by the engine, the first exhaust pipe is built-in in the silencing cavity and is in communication with the silencing cavity, so as to discharge the exhaust gas of the gas purification chamber to the silencing cavity. The gas purification device is built-in in the gas purification chamber. The second exhaust pipe is connected to the silencing cavity, and the second exhaust pipe is used for discharging the exhaust gas from the silencing cavity.
[0007] The exhaust silencing system for a vehicle provided by the embodiment of the present application directly introduces the exhaust gas from the engine into the gas purification chamber, and uses the gas purification device to clean the exhaust gas. The cleaned gas directly enters the silencing chamber through the first exhaust pipe for noise reduction, and is finally discharged from the second exhaust pipe.
[0008] It can be understood that the gas purification chamber is integrated in the muffling chamber, so that the exhaust silencing system is highly integrated, the layout of the exhaust pipeline is reduced, and the space utilization is improved; at the same time, because the tail gas directly discharged from the engine enters the gas purification chamber, the heat from the tail gas will not pass through the battery pack and other parts of the chassis, and the battery, fuel tank, wire harness, water pipe and other chassis parts have no heat damage problem, and no additional heat insulation measures are required; in addition, the path of the tail gas flow is greatly reduced, which can reduce the back pressure, improve the engine power, and reduce the fuel consumption.
[0009] Optionally, the gas purification device comprises a three-way catalyst and a particulate trap, the three-way catalyst is used to treat gaseous pollutants in the exhaust gas, and the particulate trap is used to treat solid particulate matters in the exhaust gas.
[0010] Optionally, along the path of the gas flow, the gas purification chamber is sequentially provided with a first chamber and a second chamber which are in communication with each other, the first chamber is in communication with the inlet pipe, the three-way catalyst is arranged in the first chamber, the second chamber is in communication with the first exhaust pipe, and the particulate trap is arranged in the second chamber.
[0011] Optionally, along the path of the gas flow, the inner diameter of the connecting section between the inlet pipe and the first chamber gradually increases; and the inner diameter of the connecting section between the first exhaust pipe and the second chamber gradually decreases.
[0012] Optionally, along the path of the gas flow, a third chamber is further arranged between the first chamber and the second chamber, the third chamber is in communication with the first chamber and the second chamber, a front pressure difference sensor and an exhaust temperature sensor are sequentially arranged in the third chamber, and a rear pressure difference sensor is arranged at the gas outlet end of the second chamber.
[0013] Optionally, a first oxygen sensor is arranged at the gas inlet end of the first chamber, and a second oxygen sensor is arranged in the third chamber.
[0014] Optionally, along the path of the gas flow, the muffling cavity comprises a first muffling cavity, a second muffling cavity and a third muffling cavity which are sequentially in communication; the end of the first exhaust pipe is built in the first muffling cavity and is in communication with the first muffling cavity; and the end of the second exhaust pipe is built in the third muffling cavity and is in communication with the third muffling cavity.
[0015] Optionally, the inner wall of the second muffling cavity is covered with glass fiber muffling cotton, the second muffling cavity is in communication with the first muffling cavity through a muffling pipe, a partition plate is arranged between the second muffling cavity and the third muffling cavity, and a plurality of muffling holes are arranged through the partition plate.
[0016] Optionally, the interior of the muffling cavity has a variable-diameter structure, and along the flow path of the gas flow in the variable-diameter structure, the cross-sectional area of the variable-diameter structure gradually expands or shrinks.
[0017] In a second aspect, the embodiments of the present application provide a vehicle, comprising a chassis, an engine and the exhaust muffling system of the first aspect, the engine and the exhaust muffling system are arranged on the chassis, and the exhaust end of the engine is connected with the inlet pipe.
[0018] The vehicle provided by the embodiments of the present application at least reduces the arrangement of the exhaust pipe, improves the space utilization of the chassis, reduces the back pressure, improves the engine power and reduces the fuel consumption. BRIEF DESCRIPTION OF DRAWINGS
[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the specific embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.
[0020] Figure 1 It is a schematic diagram of the overall structure of the exhaust muffling system in some embodiments of the present application;
[0021] Figure 2 It is a perspective sectional view of the exhaust muffling system (overall sectional view) in some embodiments of the present application;
[0022] Figure 3 It is a perspective sectional view of the exhaust muffling system (the gas purification chamber is not sectioned) in some embodiments of the present application;
[0023] Figure 4 It is Figure 3 It is an enlarged view of part A of FIG. 8.
[0024]
Explanation of reference signs
[0025] 100, muffling chamber; 110, muffling cavity; 111, first muffling cavity; 112, second muffling cavity; 113, third muffling cavity; 114, muffling pipe; 115, partition; 1151, muffling hole; 116, variable-diameter structure;
[0026] 200, gas purification chamber; 210, inlet pipe; 220, first exhaust pipe; 230, first cavity; 231, first oxygen sensor; 240, second cavity; 241, rear differential pressure sensor; 250, third cavity; 251, front differential pressure sensor; 252, exhaust temperature sensor; 253, second oxygen sensor;
[0027] 300, gas purification device; 301, three-way catalyst; 302, particulate trap;
[0028] 400, second exhaust pipe; DETAILED DESCRIPTION
[0029] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.
[0030] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as those commonly understood by one of ordinary skill in the art to which this application belongs; the terms used in the specification of the present application are only for the purpose of describing the specific embodiments and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover the non-exclusive inclusion. The terms "first", "second" and the like in the specification and claims of the present application and the above description of drawings are used to distinguish different objects, and are not intended to describe a particular order or primary and secondary relationship.
[0031] In the present application, the phrase "embodiment" means that the specific features, structures or characteristics described in connection with the embodiment can be included in at least one embodiment of the present application. The phrase appears in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in the present application can be combined with other embodiments.
[0032] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "attachment" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.
[0033] The term "and / or" in the present application is only used to describe the association relationship of the associated objects, which means that there can be three relationships, for example, the exhaust silencing system and / or the vehicle can mean that there are three cases of only the exhaust silencing system, the exhaust silencing system and the vehicle, and only the vehicle. In addition, the character " / " in the present application generally represents that the front and rear associated objects are in an "or" relationship.
[0034] The "multiple" appearing in the present application refers to two or more (including two), and similarly, "multiple groups" refers to two or more groups (including two groups), and "multiple pieces" refers to two or more pieces (including two pieces).
[0035] The vehicle of the embodiment of the present application, with reference to Figure 1 , comprises a chassis, an engine and an exhaust silencing system, the engine and the exhaust silencing system are arranged on the chassis, and the exhaust end of the engine is connected with the air inlet pipe 210, wherein, with reference to Figure 1 、 Figure 2 and Figure 4 , the exhaust silencing system comprises a silencing chamber 100, a gas purification chamber 200, a gas purification device 300 and a second exhaust pipe 400; the silencing chamber 100 is internally provided with at least one silencing cavity 110 for noise reduction; the gas purification chamber 200 is built-in in the silencing chamber 100, the gas purification chamber 200 is provided with an air inlet pipe 210 and a first exhaust pipe 220, the air inlet pipe 210 is used for receiving the exhaust gas generated by the engine, the first exhaust pipe 220 is built-in in the silencing cavity 110 and communicates with the silencing cavity 110, so as to discharge the exhaust gas of the gas purification chamber 200 to the silencing cavity 110; the gas purification device 300 is built-in in the gas purification chamber 200; the second exhaust pipe 400 is connected to the silencing cavity 110, and the second exhaust pipe 400 is used for discharging the exhaust gas from the silencing cavity 110.
[0036] In actual operation of the vehicle, the exhaust gas generated by the operation of the engine directly enters the gas purification chamber 200 connected with the air inlet pipe 210, the exhaust gas flows through the built-in gas purification device 300 in the gas purification chamber 200 to complete the pollutant treatment, and then is introduced into the silencing cavity 110 inside the silencing chamber 100 through the first exhaust pipe 220. The sound waves are reflected, interfered and attenuated under the action of the structure of the silencing cavity 110, and the finally treated exhaust gas is discharged from the system through the second exhaust pipe 400.
[0037] In summary, the exhaust gas directly enters the gas purification chamber 200 from the engine, and the gas purification device 300 is used to clean the exhaust gas, and the cleaned gas directly enters the silencing chamber 100 through the first exhaust pipe 220 for noise reduction, and finally is discharged from the second exhaust pipe 400.
[0038] It can be understood that integrating the gas purification chamber 200 in the muffling chamber 100 makes the exhaust muffling system highly integrated, integrates the purification and noise reduction functions, reduces the layout of the exhaust pipeline, and improves the space utilization. At the same time, because the exhaust gas directly enters the gas purification chamber 200 from the engine, the heat from the exhaust gas does not pass through the battery pack and other parts of the chassis, and the battery, fuel tank, wire harness, water pipe and other chassis parts have no heat damage problem, and no additional heat insulation measures are needed. In addition, the path of the exhaust gas flow is greatly reduced, which can reduce the back pressure, improve the engine power, and reduce fuel consumption.
[0039] In some embodiments, referring to Figure 2 , the gas purification device 300 includes a three-way catalyst 301 for treating gaseous pollutants in the exhaust gas and a particulate trap 302 for treating solid particulate matter in the exhaust gas. As a further optimization of the above-mentioned embodiments, along the path of the gas flow, the gas purification chamber 200 is provided with a first chamber 230 and a second chamber 240 in sequence, which are in communication with each other. The first chamber 230 is in communication with the inlet pipe 210, the three-way catalyst 301 is arranged in the first chamber 230, the second chamber 240 is in communication with the first exhaust pipe 220, and the particulate trap 302 is arranged in the second chamber 240.
[0040] Along the path of the gas flow, the exhaust gas first enters the first chamber 230 and flows through the three-way catalyst 301. The noble metal catalyst on the surface of the carrier of the three-way catalyst 301 promotes the oxidation-reduction reaction of nitrogen oxides, carbon monoxide and hydrocarbons, and converts them into harmless gases. Then the gas flow enters the second chamber 240 and flows through the particulate trap 302. The particulate trap 302 has a porous wall flow structure, which intercepts and burns soot particles, and finally realizes the staged treatment of gaseous and solid pollutants. It should be noted that the separation design of the first chamber 230 and the second chamber 240 enables the two different gas purification devices 300 to independently complete the purification, thereby improving the purification efficiency.
[0041] In some embodiments, along the path of the gas flow, referring to the arrow direction in Figure 2 , the inner diameter of the connecting section between the inlet pipe 210 and the first chamber 230 gradually increases; the inner diameter of the connecting section between the first exhaust pipe 220 and the second chamber 240 gradually decreases. Along the path of the gas flow, when the exhaust gas enters the first chamber 230 from the inlet pipe 210, the flow cross section gradually expands, the flow rate decreases, and the residence time of the gas in the three-way catalyst 301 increases; when the purified gas flow enters the first exhaust pipe 220 from the second chamber 240, the cross section contracts, the flow rate increases, and the vortex dead zone is prevented from forming in the outlet area, which promotes the purified gas flow to be discharged into the muffling chamber 110.
[0042] Further, along the path of the gas flow, referring to Figure 2, a third chamber 250 is further arranged between the first chamber 230 and the second chamber 240, the third chamber 250 is in communication with the first chamber 230 and the second chamber 240, a front pressure difference sensor 251 and an exhaust temperature sensor 252 are sequentially arranged in the third chamber 250, and the gas outlet end of the second chamber 240 is provided with a rear pressure difference sensor 241.
[0043] In actual use, along the path of the gas flow, the exhaust gas purified by the three-way catalyst 301 enters the third chamber 250 and passes through the front pressure difference sensor 251 and the exhaust temperature sensor 252, and after the exhaust gas is purified by the particulate filter 302, the purified gas passes through the rear pressure difference sensor 241. In the above process, the front pressure difference sensor 251 is used to measure the exhaust gas pressure at the inlet end of the particulate filter 302, and the rear pressure difference sensor 241 is used to measure the exhaust gas pressure at the outlet end of the particulate filter 302, and the pressure drop (ΔP) is calculated by combining the data of the front pressure difference sensor, and the accumulation amount (load degree) of particulate matter is judged by the pressure drop (ΔP), and the regeneration opportunity (active or passive regeneration) is triggered, wherein the increase of the pressure drop (ΔP) indicates the increase of the soot accumulation.
[0044] In addition, the rear pressure difference sensor 241 can detect whether the particulate filter 302 is blocked or damaged by measuring the pressure of the purified gas flow, and when the pressure difference is abnormally high, it means that the particulate filter 302 is blocked or the soot is excessive; when the pressure difference is abnormal, it means that the particulate filter 302 is damaged or the sensor is faulty.
[0045] Further, the exhaust temperature sensor 252 monitors the temperature of the purified gas from the three-way catalyst 301, and ensures that the temperature is within the range required for the regeneration of the particulate filter 302 through the control unit, and accurately controls the temperature required for the regeneration process of the particulate filter 302.
[0046] It should be noted that the above-mentioned calculation of the change of the permeability of the filter by comparing the front and rear pressure differences is a conventional detection technology in the art, which will not be described further herein.
[0047] Further, with reference to Figure 2 , the gas inlet end of the first chamber 230 is provided with a first oxygen sensor 231, and the third chamber 250 is provided with a second oxygen sensor 253.
[0048] Specifically, the first oxygen sensor 231 is installed in the exhaust manifold, the first oxygen sensor 231 monitors the oxygen content in the original exhaust gas of the engine, calculates the air-fuel ratio deviation, and feeds back a signal to the ECU, and the ECU can dynamically adjust the fuel injection amount according to the front oxygen signal to ensure the combustion efficiency;
[0049] The second oxygen sensor 253 is located downstream of the three-way catalyst 301 and detects the oxygen concentration of the exhaust gas after purification by the three-way catalyst 301. By comparing the signals of the two oxygen sensors, the efficiency of the three-way catalyst 301 can be determined.
[0050] It should be noted that the above-mentioned dual oxygen sensor forms a closed-loop feedback control, which is a conventional detection technology in the field and will not be described further herein.
[0051] In some embodiments, with reference to Figure 3 , the inside of the muffling cavity 110 has a multi-section variable-diameter structure 116. Along the flow path of the gas flow, the cross-sectional area of the variable-diameter structure 116 gradually expands or shrinks. When the purified gas flow flows in the muffling cavity 110, the variable-diameter structure 116 can change the flow rate and pressure of the gas flow. The expanded cross-section reduces the gas flow rate and pressure loss, while the reduced cross-section increases the gas flow rate and pressure. This changing flow state helps to diffuse and absorb sound waves, improving the muffling effect. Specifically, the variable-diameter structure 116 of the muffling cavity 110 can effectively eliminate medium and low frequency noise.
[0052] Specifically, along the flow path of the gas flow, with reference to Figure 2 and Figure 3 , the muffling cavity 110 includes a first muffling cavity 111, a second muffling cavity 112, and a third muffling cavity 113 connected in sequence; the end of the first exhaust pipe 220 is built-in the first muffling cavity 111 and communicates with the first muffling cavity 111; the end of the second exhaust pipe 400 is built-in the third muffling cavity 113 and communicates with the third muffling cavity 113. The first muffling cavity 111, the second muffling cavity 112, and the third muffling cavity 113 form a three-stage muffling structure, which can effectively broaden the frequency range of muffling and improve the noise reduction effect. Preferably, in some embodiments, with reference to Figure 4 , the inner wall of the second muffling cavity 112 is covered with glass fiber muffling cotton, the second muffling cavity 112 communicates with the first muffling cavity 111 through a muffling pipe 114, and a partition plate 115 is provided between the second muffling cavity 112 and the third muffling cavity 113, and a plurality of muffling holes 1151 are provided through the partition plate 115. The purified exhaust gas is injected into the first muffling cavity 111 along the flow path of the gas flow through the first exhaust pipe 220. The sound wave is first expanded and reflected in the cavity, then enters the second muffling cavity 112 along the flow path of the gas flow through the muffling pipe 114, the medium and high frequency sound energy excites the glass fiber muffling cotton to vibrate and convert into heat energy, and the medium and high frequency sound is eliminated, finally, the low frequency sound wave is eliminated by passing through the muffling holes 1151 on the partition plate 115 along the flow path of the gas flow.
[0053] It should also be noted that the terms "comprising", "comprises" or other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus.
[0054] Various embodiments in the present specification are described in progressive manner, and the same or similar parts between embodiments can be mutually referred to. Each embodiment focuses on the difference from other embodiments. In particular, for system embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the part of the method embodiments.
[0055] The above only describes the embodiments of the present application and is not intended to limit the present application. The present application can have various modifications and changes for those skilled in the art. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the scope of claims of the present application.
[0056] Although the embodiments of the present application are described in conjunction with the drawings, various modifications and changes can be made by those skilled in the art without departing from the spirit and scope of the present application, and such modifications and changes fall within the scope defined by the appended claims.
Claims
1. An exhaust silencing system for a vehicle, characterized by, The application relates to a silencer chamber (100) internally provided with at least one silencer cavity (110) for noise reduction; a gas purification chamber (200) internally arranged in the silencer chamber (100), the gas purification chamber (200) being provided with an air inlet pipe (210) for receiving engine generated exhaust gas and a first exhaust pipe (220) internally arranged in the silencer cavity (110) and in communication with the silencer cavity (110) to discharge the exhaust gas of the gas purification chamber (200) to the silencer cavity (110); a gas purification device (300) internally arranged in the gas purification chamber (200); a second exhaust pipe (400) connected to the silencer cavity (110) for discharging exhaust gas from the silencer cavity (110); wherein, along the path of gas flow, the silencer cavity (110) comprises a first silencer cavity (111), a second silencer cavity (112) and a third silencer cavity (113) in sequence; the end of the first exhaust pipe (220) is internally arranged in the first silencer cavity (111) and in communication with the first silencer cavity (111); the end of the second exhaust pipe (400) is internally arranged in the third silencer cavity (113) and in communication with the third silencer cavity (113); the inner wall of the second silencer cavity (112) is covered with glass fiber silencer cotton; the second silencer cavity (112) is in communication with the first silencer cavity (111) through a silencer pipe (114); a partition plate (115) is arranged between the second silencer cavity (112) and the third silencer cavity (113), and a plurality of silencer holes (1151) are arranged through the partition plate (115); the inside of the silencer cavity (110) has a plurality of variable diameter structures (116), and along the flow path of the gas flow in the variable diameter structures (116), the cross-sectional area of the variable diameter structures (116) gradually expands or shrinks. The gas purification device (300) comprises a three-way catalyst (301) for treating gaseous pollutants in exhaust gas and a particulate trap (302) for treating solid particulate matters in exhaust gas. Along the path of gas flow, the gas purification chamber (200) is sequentially provided with a first chamber (230) and a second chamber (240) in communication with each other, the first chamber (230) is in communication with the air inlet pipe (210), the three-way catalyst (301) is arranged in the first chamber (230), the second chamber (240) is in communication with the first exhaust pipe (220), and the particulate trap (302) is arranged in the second chamber (240). Along the path of gas flow, the inner diameter of the connecting section between the air inlet pipe (210) and the first chamber (230) gradually increases; and the inner diameter of the connecting section between the first exhaust pipe (220) and the second chamber (240) gradually decreases. 2. The exhaust silencing system of claim 1, wherein 3. The exhaust silencing system of claim 2, wherein, 4. The exhaust silencing system of claim 3, wherein 5. The exhaust silencing system of claim 3, wherein Along the path of gas flow, a third chamber (250) is further arranged between the first chamber (230) and the second chamber (240), the third chamber (250) is in communication with the first chamber (230) and the second chamber (240), a front pressure difference sensor (251) and a exhaust temperature sensor (252) are sequentially arranged in the third chamber (250), and a rear pressure difference sensor (241) is arranged at the gas outlet end of the second chamber (240).
6. The exhaust silencing system of claim 5, wherein, A first oxygen sensor (231) is arranged at the gas inlet end of the first chamber (230), and a second oxygen sensor (253) is arranged in the third chamber (250).
7. A vehicle characterized by comprising: The exhaust silencing system comprises a chassis, an engine and the exhaust silencing system according to any one of claims 1-6, the engine and the exhaust silencing system are arranged on the chassis, and the exhaust end of the engine is connected with the inlet pipe (210).