A muffler that reduces both flow resistance and noise

Abstract

The present invention discloses a muffler that takes into account both reducing flow resistance and noise, comprising: a muffler shell, an air intake pipe provided on one side of the muffler shell, the air intake pipe being used to connect to the exhaust pipe of the engine; an exhaust structure provided on a side of the muffler shell cavity away from the air intake pipe; when the air flow velocity in the muffler is less than a preset flow velocity value, a resonance cavity is formed on the exhaust structure, and the resonance cavity reduces exhaust noise through resonance; when the air flow velocity in the muffler is greater than the preset flow velocity value, the air flow opens a valve structure under the guidance of the fully perforated pipe section of the resonance pipe, thereby preventing the air flow from dispersing in the resonance cavity. The present invention provides a muffler that takes into account both reducing flow resistance and noise, has a compact structure, occupies a small space, is low in cost, has a simple manufacturing process, and is suitable for mass production requirements.

Description

Technical Field

[0001] The present invention relates to the technical field of commercial vehicle exhaust, and in particular to a muffler capable of reducing both flow resistance and noise. Background Art

[0002] With the increasing production and sales of automobiles, exhaust emissions and noise pollution have become an environmental challenge that plagues the healthy development of cities. Currently, diesel engine exhaust systems are moving toward integrated designs, integrating the exhaust gas purification system with the exhaust muffler structure to meet lightweight and space-saving requirements. Due to this integrated design, existing mufflers that balance flow resistance and noise reduction are limited in size and space, making it difficult to achieve both low- and mid-frequency noise reduction and flow resistance reduction. This results in poor muffler performance at low and mid-frequency frequencies, particularly insufficient reduction of engine-order noise, which seriously impacts the overall vehicle exhaust sound quality. Summary of the Invention

[0003] The present invention aims to provide a muffler that simultaneously reduces flow resistance and noise, resolving the problem that existing mufflers that simultaneously reduce flow resistance and noise struggle to simultaneously reduce mid- and low-frequency noise and flow resistance. This muffler features a rational structural design and simple manufacturing process, effectively reducing exhaust flow resistance, promoting mixing of urea and airflow, and controlling low-frequency order noise in the exhaust.

[0004] The technical solution adopted by the present invention to solve the technical problem is to provide a muffler that can reduce both flow resistance and noise, including:

[0005] A muffler housing, wherein an air intake pipe is provided on one side of the muffler housing, and the air intake pipe is used to connect to the exhaust pipe of the engine;

[0006] An exhaust structure, the exhaust structure being arranged on a side of the muffler housing cavity away from the air intake pipe;

[0007] When the air flow velocity in the muffler is less than the preset flow velocity value, a resonance cavity is formed on the exhaust structure, and the resonance cavity reduces the exhaust noise through resonance; when the air flow velocity in the muffler is greater than the preset flow velocity value, the resonance cavity on the exhaust structure becomes an expansion cavity, and the expansion cavity is used to reduce the flow resistance of the air flow.

[0008] A further solution is that the exhaust structure includes a first baffle, a second baffle, a resonance pipe, an exhaust pipe, and a rear end cover provided at the end of the muffler shell;

[0009] The first partition plate, the second partition plate and the muffler shell form a fourth expansion chamber, and the second partition plate, the rear end cover and the muffler shell form a resonance chamber;

[0010] The resonance tube includes a resonance tube perforated section and a resonance tube resonant section. The resonance tube perforated section is mounted on the first and second baffles. One end of the resonance tube perforated section extends to the outside of the fourth expansion chamber after passing through the first baffle. A plurality of first tube holes are spaced apart on a side wall of the resonance tube perforated section located in the fourth expansion chamber. The resonance tube resonant section is disposed in the resonance chamber, and an air outlet of the resonance tube resonant section is directly opposite to the valve structure on the second baffle.

[0011] When the air flow velocity in the resonance pipe section of the resonance tube is greater than the preset flow velocity value, the valve structure automatically opens; when the air flow velocity in the resonance pipe section of the resonance tube is less than the preset flow velocity value, the valve structure automatically closes;

[0012] The exhaust pipe includes a perforated section and a curved section. The air inlet end of the perforated section of the exhaust pipe passes through the second partition and extends into the fourth expansion cavity; the air outlet end of the perforated section of the exhaust pipe passes through the rear end cover and extends to the outside of the muffler shell, and is connected to the curved section.

[0013] It can be seen from the above technical solution that when the air flow rate is relatively low, the valve structure automatically closes. At this time, the air flow flows into the fourth expansion chamber through the first tube hole on the perforated section of the resonance tube, and then is discharged into the atmosphere through the outlet pipe. Since the valve structure on the second baffle is closed, the cavity between the second baffle and the rear end cover does not pass air flow, and the second baffle and the rear end cover form a resonance chamber, which plays a resonance role and can effectively control low-frequency noise; when the air flow rate is relatively high, corresponding to the high engine speed, the low-frequency order sound will move to the medium and high frequencies, and the valve structure automatically opens, turning the resonance chamber into an expansion chamber. Since the first tube hole on the perforated section of the resonance tube is small, the resistance to the passage of large air flow is relatively large. At this time, the large air flow enters the fourth expansion chamber through the resonance chamber and the valve structure, rather than entering the fourth expansion chamber through the first tube hole, which facilitates the rapid passage of air flow and reduces exhaust pressure loss, so that the exhaust structure plays a role in reducing medium and low frequency noise when the air flow is small, and plays a role in reducing flow resistance when the air flow is large, thereby taking into account both the reduction of medium and low frequency noise and the reduction of flow resistance.

[0014] A further solution is that the valve structure includes a circular cover and a torsion spring, the circular cover is rotatably connected to a surface of the second partition away from the rear end cover, and the torsion spring is sleeved on the rotating shaft of the circular cover.

[0015] It can be seen from the above technical solution that when the air flow rate is small, the air flow is not enough to overcome the torsion of the torsion spring, and thus the valve structure cannot be opened. When the air flow rate is large, the air flow can overcome the torsion of the torsion spring, thereby automatically opening the valve structure, thereby automatically realizing the opening and closing of the valve structure. Compared with detecting the air flow rate through a sensor and then controlling the opening and closing of the valve structure according to the detected flow rate value, the structure of this application is simple and easy to operate.

[0016] A further solution is that the side wall of the perforated section of the air outlet pipe is wrapped with a resistive bag, a sound absorbing material is arranged in the resistive bag, and a plurality of second tube holes are spaced apart on the side wall of the perforated section of the air outlet pipe in contact with the resistive bag.

[0017] A further solution is that one end of the resonance tube bend section away from the resonance tube perforated section is against the valve structure, and a resonance tube fully perforated section is provided at the end of the resonance tube bend section, and a plurality of circles of third tube holes are opened on the resonance tube fully perforated section, and a cascade micro-perforated resonance cavity is provided on the outside of the resonance tube perforated section, and a third partition is provided in the cascade micro-perforated resonance cavity, and the cascade micro-perforated resonance cavity is divided into a plurality of chambers of different sizes by the third partition, and a plurality of circles of micro-perforations are opened on the side wall of the resonance tube perforated section, and the size of the micro-perforations corresponds to the size of the chamber.

[0018] As can be seen from the above technical solution, a fully perforated section of the resonance tube is added to the end of the resonance tube, and the end of the fully perforated section of the resonance tube abuts the valve structure; when the airflow velocity is low, the airflow velocity is not enough to open the valve structure. At this time, the third tube hole on the fully perforated section of the resonance tube is used for sound transmission, so that the resonance tube plays the role of resonance silencer; when the airflow velocity is high, the fully perforated section of the resonance tube can guide the airflow to impact the valve structure. Since the end of the fully perforated section of the resonance tube abuts the valve structure, the airflow can be prevented from being dispersed, achieving the purpose of reducing airflow resistance, thereby further reducing the exhaust back pressure of the muffler. In addition, a cascaded micro-perforated resonance cavity is added to the perforated section of the resonance tube. The cascaded micro-perforated resonance cavity is divided into several chambers of different sizes by the third partition. A circle of micro-perforations is opened on the wall of the resonance tube corresponding to each chamber; by adjusting the chamber size, the aperture and number of micro-perforations, the resonance silencer frequency band and bandwidth of the cascaded micro-perforated resonance cavity can be adjusted. When the air flow velocity is low, the cascaded micro-perforated resonance cavity and the resonance tube are coupled with each other, which enhances the low-frequency noise reduction capability of the entire muffler and can more effectively adjust the low-frequency noise reduction frequency band and bandwidth.

[0019] A further solution is that a rubber pad is provided on the side of the circular cover that contacts the second partition plate. It is understandable that by providing the rubber pad, the sealing between the circular cover and the second partition plate can be improved, thereby improving the sealing of the valve structure.

[0020] A further solution is that a front end cover is installed at one end of the muffler housing away from the exhaust structure, the intake pipe is installed on the front end cover, and a urea nozzle is also installed on the front end cover, and the urea nozzle is used to spray urea spray into the inner cavity of the muffler housing.

[0021] A further solution is that the angle between the air intake pipe and the air outlet direction of the urea nozzle is 15°.

[0022] A further solution is that a catalytic converter is also provided in the middle of the inner cavity of the muffler shell, and the catalytic converter includes a first-stage catalytic converter and a second-stage catalytic converter arranged at intervals, and the first-stage catalytic converter and the second-stage catalytic converter are provided with a porous ceramic carrier and coated with a precious metal catalyst. The first-stage catalytic converter and the second-stage catalytic converter are spaced a distance from each other and form a second expansion cavity with the muffler shell.

[0023] A further solution is that an eccentric cone structure is installed on the side of the inner cavity of the muffler shell close to the front end cover, and the eccentric cone structure includes an eccentric cone, and the eccentric cone is installed in the first ring through a first cross structure. The first ring is fixed on the inner wall of the muffler shell, and the tip of the eccentric cone is facing the outlet of the intake pipe.

[0024] It can be seen from the above technical solution that the eccentric cone can disturb the airflow sprayed into the muffler shell cavity, change the direction of the airflow, and facilitate more mixing of the airflow and the reducing agent spray. In addition, the urea spray sprayed from the urea nozzle is at a certain angle to the outlet direction of the intake pipe, which is conducive to more mixing of the airflow and the urea spray, facilitates the rapid mixing of the mixture, and improves the mixing efficiency and mixing effect.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) when the air flow velocity is relatively low, the valve structure automatically closes, and at this time the air flow flows into the fourth expansion chamber through the first tube hole on the perforated section of the resonance tube, and then is discharged into the atmosphere through the exhaust pipe. Since the valve structure on the second baffle is closed, the cavity between the second baffle and the rear end cover does not pass air flow, and the second baffle and the rear end cover form a resonance chamber, which plays a role of resonance and can effectively control low-frequency noise; when the air flow velocity is relatively high, corresponding to the high engine speed, the low-frequency order sound will move to the medium and high frequency, and the valve structure automatically opens, turning the resonance chamber into an expansion chamber. Since the first tube hole on the perforated section of the resonance tube is small, the resistance to the passage of large air flow is relatively large. At this time, the large air flow enters the fourth expansion chamber through the resonance chamber and the valve structure, rather than entering the fourth expansion chamber through the first tube hole, which facilitates the rapid passage of air flow and reduces the exhaust pressure loss, so that the exhaust structure plays a role in reducing medium and low frequency noise when the air flow is small, and plays a role in reducing flow resistance when the air flow is large, thereby taking into account both the role of reducing medium and low frequency noise and reducing flow resistance;

[0026] (2) The end of the fully perforated section of the resonance tube of the present invention abuts against the valve structure. When the airflow velocity is high, the airflow opens the valve structure under the guidance of the fully perforated section of the resonance tube, which can prevent the airflow from dispersing in the resonance cavity, thereby achieving the purpose of reducing the airflow resistance, thereby further reducing the exhaust back pressure of the muffler; when the airflow velocity is low, the engine speed is low, and the low-frequency order sound frequency is also low at this time, and the low-frequency muffler capability is required to be high. By coupling the cascaded micro-perforated resonance cavity and the resonance tube, the low-frequency muffler capability of the entire muffler is further enhanced, and the low-frequency muffler frequency band and bandwidth can be more effectively adjusted;

[0027] (3) The present invention provides a muffler that takes into account both flow resistance reduction and noise reduction, has a compact structure, occupies a small space, has low cost, and has a simple manufacturing process, and is suitable for mass production requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0029] Figure 1 This is a schematic diagram of the internal structure of a muffler that takes both flow resistance reduction and noise reduction into account according to an embodiment of the present invention;

[0030] Figure 2 This is a schematic structural diagram of a multi-annular spanwise corrugated rod structure of a muffler that takes into account both flow resistance reduction and noise reduction according to an embodiment of the present invention;

[0031] Figure 3 This is a schematic structural diagram of a resonance tube of a muffler that takes both flow resistance reduction and noise reduction into account according to an embodiment of the present invention;

[0032] Figure 4 This is a schematic structural diagram of an eccentric cone structure of a muffler that takes both flow resistance reduction and noise reduction into account according to an embodiment of the present invention;

[0033] Figure 5 This is a schematic structural diagram of an outlet pipe of a muffler that takes both flow resistance reduction and noise reduction into account according to an embodiment of the present invention;

[0034] Figure 6 This is a structural schematic diagram of a valve structure on the second partition of a muffler that takes both flow resistance reduction and noise reduction into account in an embodiment of the present invention.

[0035] Reference numerals: 1 flange; 2 intake pipe; 3 urea nozzle; 4 front end cover; 5 first expansion chamber; 6 eccentric cone structure; 7 multi-annular spanwise corrugated rod structure; 8 sensor mounting seat; 9 primary catalytic converter; 10 second expansion chamber; 11 secondary catalytic converter; 12 third expansion chamber; 13 first partition plate; 14 fourth expansion chamber; 15 second partition plate; 16 resonance chamber; 17 rear end cover; 18 outlet pipe; 19 resonance pipe; 20 valve structure; 601 eccentric cone; 602 first cross structure; 603 First circular ring; 701 annular spanning corrugated rod; 702 second cross structure; 703 second circular ring; 1801 perforated section of the air outlet pipe; 1802 resistive package; 1803 bent pipe section; 1804 second tube hole; 1901 perforated section of the resonance tube; 1902 bent pipe section of the resonance tube; 1903 first tube hole; 1904 fully perforated tube section of the resonance tube; 1905 cascaded micro-perforated resonance cavity; 1906 third partition; 1907 micro-perforation; 1908 third tube hole; 2001 circular cover; 2002 torsion spring. DETAILED DESCRIPTION

[0036] In order to make the objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0037] It should be noted that when an element is referred to as being “fixed to” another element, it may be directly on the other element or there may be an intermediate element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or there may be an intermediate element.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used in this specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0039] As attached Figure 1Figure 2 shows the internal structure of a muffler designed to minimize flow resistance and reduce noise. The muffler comprises a flange 1, a muffler housing, a front cover 4, a rear cover 17, an air inlet pipe 2, an air outlet pipe 18, a urea nozzle 3, a sensor mounting base 8, a multi-annular spanwise corrugated rod structure 7, an eccentric conical structure 6, a first baffle 13, a second baffle 15, a primary catalytic converter 9, a secondary catalytic converter 11, a resonance tube 19, and a valve structure 20. The flange 1 is welded to the front end of the intake pipe 2 to connect the muffler to the exhaust pipe flange of the engine; the muffler shell, the front cover 4 and the rear cover 17 constitute the outer boundary of the muffler, which determines the size space of the total container of the muffler; the intake pipe 2 and the urea nozzle 3 are welded to the front cover; the sensor mounting seat 8 is welded to the appropriate position on the muffler shell, and the sensor mounting seat 8 is equipped with a detection sensor, which includes an oxygen content and a nitrogen oxide content detection sensor. The detection sensor senses the change of the content of specific components in the exhaust gas and feeds back relevant signals for adjusting the injection amount of urea; the first-stage catalytic converter 9, the front cover 4 and the muffler shell constitute the first expansion chamber 5; the eccentric cone structure 6 is located between the front cover 4 and the multi-annular spanning corrugated rod structure 7 , causing disturbance to the airflow sprayed into the cavity from the intake pipe 2, changing the direction of the airflow so that the airflow is more mixed with the urea spray; the multi-annular span-wise corrugated rod structure 7 is located in the first expansion cavity 5, which has a good modulation effect on the urea and airflow mixture, thereby improving the exhaust gas conversion rate, and making the urea and airflow mixture enter the first-stage catalytic converter 9 evenly, thereby improving the catalytic efficiency, making the mixture passing therethrough smoother, reducing the resistance of the airflow, and reducing the exhaust back pressure; the catalytic converter includes a first-stage catalytic converter 9 and a second-stage catalytic converter 11. The first-stage catalytic converter 9 and the second-stage catalytic converter 11 are provided with a porous ceramic carrier and coated with a precious metal catalyst, which cooperates with the urea spray to reduce and catalyze the pollutants in the airflow and decompose the carbon monoxide and nitrogen oxides in the exhaust.

[0040] There is a distance between the first-stage catalytic converter 9 and the second-stage catalytic converter 11, forming a second expansion chamber 10; the second-stage catalytic converter 11, the first partition plate 13 and the muffler shell 20 form a third expansion chamber 12; the first partition plate 13, the second partition plate 15 and the muffler shell 20 form a fourth expansion chamber 14, and the resonance tube 19 is welded and fixed on the first partition plate 13 and the second partition plate 15, for connecting the third expansion chamber 12 and the resonance chamber 16; the second partition plate 15 and the rear end cover 17 and the muffler shell form the resonance chamber 16; the exhaust pipe 18 is welded and fixed on the second partition plate 15 and the rear end cover 17, connecting the fourth expansion chamber 14 and the external atmospheric environment.

[0041] As attached Figure 2As shown, a multi-annular span-wise corrugated rod structure 7 of a muffler of the present invention that takes into account both flow resistance and noise reduction is provided. The multi-annular span-wise corrugated rod structure 7 is composed of annular span-wise corrugated rods 701 of different radii fixed to a second circular ring 703 via a second cross structure 702. The outer end of the second circular ring 703 is welded and fixed to the outer shell of the muffler. The multi-annular span-wise corrugated rod structure 7 divides the large-space turbulence caused by the eccentric cone structure 6 into concentric ring layers to make it uniform. When the airflow passes around the annular span-wise corrugated rods 701, it generates tiny longitudinal and transverse turbulence, which allows the urea spray and airflow to mix better at the microscopic level, so that the urea and airflow mixture enters the catalytic converter evenly, thereby improving the catalytic efficiency. In addition, the multi-annular span-wise corrugated rod structure 7 itself has low flow resistance, which makes the mixture passing through it smoother, reduces the resistance to the airflow, and reduces the exhaust back pressure.

[0042] Optionally, there are two multi-annular span-wise corrugated rod structures 7, which are spaced apart in the muffler housing inner cavity along the airflow direction, and the projections of the annular span-wise corrugated rods 701 on the two multi-annular span-wise corrugated rod structures 7 are staggered, that is, the projection of the annular span-wise corrugated rods 701 on one multi-annular span-wise corrugated rod structure 7 on the other multi-annular span-wise corrugated rod structure 7 coincides with the gap between the annular span-wise corrugated rods 701 on the other multi-annular span-wise corrugated rod structure 7. After passing through the two-stage multi-annular span-wise corrugated rod structure 7, the exhaust gas flow is fully mixed with the urea spray, thereby improving the conversion efficiency of pollutants in the exhaust gas, allowing the urea and airflow mixture to evenly enter the first-stage catalytic converter 9, thereby improving the catalytic efficiency, making the urea mixture passing therethrough smoother, reducing the resistance to the airflow, and reducing the exhaust back pressure.

[0043] As attached Figure 3 As shown, a resonance pipe 19 of a muffler of the present invention is provided for reducing flow resistance and noise. The resonance tube 19 is composed of a resonance tube perforated section 1901 and a resonance tube bent section 1902. A plurality of first tube holes 1903 are spaced apart on the side wall of the resonance tube perforated section 1901 located in the fourth expansion chamber 14. When the airflow passing through the third expansion chamber 12 is a small airflow, the airflow enters the fourth expansion chamber 14 through the resonance tube perforated section 1901 and is discharged to the atmosphere through the outlet pipe 18. At this time, the valve structure 20 on the second baffle 15 is closed, and the second baffle 15 and the rear end cover 17 form a resonance chamber 16. The resonance chamber 16 does not pass airflow, which can effectively control low-frequency order noise. When the airflow passing through the third expansion chamber 12 is a large airflow, the resistance of the large airflow through the first tube holes 1903 is relatively large. Under the action of the large airflow, the valve structure 20 fixed to the second baffle 15 opens, and the airflow passes through the resonance tube 19 and then enters the fourth expansion chamber 14 and is discharged to the atmosphere through the outlet pipe 18, thereby facilitating the rapid passage of airflow, reducing flow resistance, and reducing exhaust pressure loss.

[0044] Optionally, see Figure 3 The end of the resonance tube bend section 1902 away from the resonance tube perforated section 1901 abuts against the valve structure 20. A resonance tube fully perforated section 1904 is provided at the end of the resonance tube bend section 1902. The resonance tube fully perforated section 1904 is provided with a plurality of circles of third tube holes 1908. A cascaded micro-perforated resonance cavity 1905 is provided on the outer side of the resonance tube perforated section 1901. Two third partitions 1906 are provided in the cascaded micro-perforated resonance cavity 1905. The cascaded micro-perforated resonance cavity 1905 is divided into a plurality of chambers of different sizes by the third partitions 1906. A plurality of circles of micro-perforations 1907 are provided on the side wall of the resonance tube perforated section 1901. The size of the micro-perforations 1907 corresponds to the size of the chamber. It can be understood that a fully perforated section 1904 of the resonance tube is added to the end of the resonance tube 19, and the end of the fully perforated section 1904 of the resonance tube is against the valve structure 20; when the air flow rate is relatively low, as mentioned above, the air flow rate is not enough to open the valve structure 20. At this time, the third tube hole 1908 on the fully perforated section 1904 of the resonance tube is used for sound transmission, so that the resonance tube 19 plays a role of resonance silencer; when the air flow rate is relatively high, the fully perforated section 1904 of the resonance tube can guide the air flow to impact the valve structure 20, and since the end of the fully perforated section of the resonance tube is against the valve structure, the air flow can be prevented from being dispersed, thereby achieving the purpose of reducing the air flow resistance, thereby further reducing the exhaust back pressure of the muffler. Furthermore, a cascaded micro-perforated resonance cavity 1905 is added to the outside of the perforated section 1901 of the resonance tube. This cascaded micro-perforated resonance cavity 1905 is divided into several chambers of varying sizes by a third partition 1906. Each chamber corresponds to a circle of micro-perforations 1907 on the wall of the resonance tube 19. By adjusting the chamber size, the aperture diameter, and the number of micro-perforations 1907, the resonance muffler frequency band and bandwidth of the cascaded micro-perforated resonance cavity 1905 can be adjusted. When the airflow velocity is low and the engine speed is low, the low-frequency infrasound frequencies are also low, requiring a high level of low-frequency muffler capability. Therefore, the coupling between the cascaded micro-perforated resonance cavity 1905 and the resonance tube 19 further enhances the low-frequency muffler capability of the entire muffler and allows for more effective adjustment of the low-frequency muffler frequency band and bandwidth.

[0045] As attached Figure 4The figure shows an eccentric cone structure 6 of a muffler according to the present invention, which balances flow resistance and noise reduction. The eccentric cone structure 6 includes an eccentric cone 601 secured to a first ring 603 via a first cross structure 602. The first ring 603 is welded to the muffler housing, with the tip of the eccentric cone 601 facing the outlet of the intake pipe 2. The eccentric cone 601 disturbs the airflow entering the cavity through the intake pipe 2, redirecting it and allowing it to mix more with the urea spray sprayed from the urea nozzle 3. This mixture then evenly enters the multi-annular, spanning corrugated rod structure 7.

[0046] As attached Figure 5 As shown, the outlet pipe 18 of the muffler of the present invention is composed of an outlet pipe perforated section 1801, an outer wrapped resistive bag 1802 and a bent pipe section 1803. Sound-absorbing material is arranged in the resistive bag 1802, and a plurality of second pipe holes 1804 are spaced apart on the side wall of the outlet pipe perforated section 1801 in contact with the resistive bag 1802. It can be understood that the outer wrapped resistive bag 1802 can absorb the noise in the outlet pipe perforated section 1801, and the air flow is discharged into the atmospheric environment through the bent pipe section 1803.

[0047] As attached Figure 6 As shown, the valve structure 20 mounted on the second baffle 15 of the muffler of the present invention comprises a circular cover 2001 and a torsion spring 2002. The circular cover 2001 is pivotally connected to the side of the second baffle 15 away from the rear end cover 17, while the torsion spring 2002 is sleeved around the rotating axis of the circular cover 2001. When a large airflow passes through the resonance tube 19, the valve structure 20 is blown open by the airflow. When a small airflow passes through the resonance tube 19, the valve structure 20 automatically closes under the action of the torsion spring 2002. At this point, the second baffle 15 and the rear end cover 17 form a resonance chamber 16, effectively controlling low-frequency noise.

[0048] The following is combined with Figure 1-6 The working principle of the integrated exhaust purification muffler of the present invention is described in detail with specific implementation:

[0049] The integrated exhaust purification muffler is connected to the exhaust pipe of the engine through a flange 1, and the exhaust gas of the diesel engine flows into the first expansion chamber 5 through the intake pipe 2; the urea nozzle 3 is welded to the front end cover 4, and forms a certain angle with the intake pipe 2; the airflow ejected from the intake pipe 2 will first pass through the eccentric cone structure 6, and the eccentric cone 601 will disturb the airflow ejected from the intake pipe 2 into the cavity, change the direction of the airflow, and make the airflow more mixed with the urea spray, so that the mixture evenly enters the multi-annular span-wise corrugated rod structure 7; then the urea spray and airflow mixture passes through the multi-annular span-wise corrugated structure 7, and the multi-annular span-wise corrugated rod structure 7 is used to inject the urea into the cavity. The corrugated structure 7 effectively modulates the airflow and urea spray mixture, improving exhaust gas conversion efficiency and ensuring uniform distribution of the urea and airflow mixture into the primary catalytic converter 9, thereby enhancing catalytic efficiency. The multi-annular span-wise corrugated structure 7 smooths the passage of the mixture, reducing airflow resistance and lowering exhaust backpressure. The mixed exhaust gas then flows into the primary catalytic converter 9, where it undergoes catalytic decomposition of exhaust pollutants while also attenuating some mid- and high-frequency noise. A second expansion chamber 10 is formed between the primary catalytic converter 9 and the secondary catalytic converter 11, providing a certain degree of noise reduction as the airflow passes through this chamber. After the mixed gas flows into the secondary catalytic converter 11, exhaust pollutants continue to be decomposed. After two stages of catalytic conversion, the exhaust gas meets national exhaust emission standards. Detection sensors, mounted on sensor mounting brackets 8 on both sides of the catalytic converter, sense changes in the content of specific exhaust components and provide feedback signals for front-end urea injection control, ensuring optimal emissions control under all operating conditions. The purified airflow flows into the third expansion chamber 12. When the airflow velocity is low, it flows through the first tube hole 1903 on the resonance tube 19 into the fourth expansion chamber 14, and then is discharged into the atmosphere through the outlet pipe 18. At this time, the valve structure 20 located on the second partition 15 is closed, and the resonance chamber 16 formed by the second partition 15 and the rear end cover 17 of the muffler can effectively control low-frequency noise. When the airflow velocity is high, the airflow opens the valve structure 20 under the guidance of the fully perforated section 1904 of the resonance tube, and the airflow enters the fourth expansion chamber 14, and then is discharged into the atmosphere through the outlet pipe 18. Because the airflow does not diverge within the resonance chamber 16, the exhaust back pressure of the muffler can be reduced. The exhaust airflow enters the outlet pipe 18 from the fourth expansion chamber 14. The outlet pipe perforated section 1801 and the resistive bag 1802 wrapped on the outside of the outlet pipe 18 cooperate to form a resistive muffler structure, which can effectively eliminate the mid- and high-frequency noise in the exhaust noise. Finally, the exhaust airflow is discharged into the atmosphere through the curved pipe section 1803.

[0050] After the exhaust airflow passes through the above structure, the discharged pollutants are catalytically converted and finally meet the national emission standards. The exhaust noise is controlled through resonance and resistance, thereby improving the sound quality of the exhaust noise.

[0051] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as a limitation to the invention.

[0052] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "example," "specific example," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0053] Obviously, the described embodiments are only some of the embodiments of the present application, rather than all of the embodiments. Mentioning "embodiment" in this article means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present embodiment application. The appearance of this phrase in various positions in the specification does not necessarily mean that they are all the same embodiments, nor are they independent or alternative embodiments that are mutually exclusive with other embodiments. It can be understood explicitly and implicitly by those skilled in the art that the embodiments described herein can be combined with other embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of this application.

[0054] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. A muffler that takes into account both reducing flow resistance and noise, characterized in that: include: A muffler housing, wherein an air intake pipe is provided on one side of the muffler housing, and the air intake pipe is used to connect to the exhaust pipe of the engine; An exhaust structure, the exhaust structure being arranged on a side of the muffler housing cavity away from the air intake pipe; When the air flow velocity in the muffler is less than a preset flow velocity value, a resonance cavity is formed on the exhaust structure, and the resonance cavity reduces the exhaust noise through resonance; when the air flow velocity in the muffler is greater than the preset flow velocity value, the resonance cavity on the exhaust structure becomes an expansion cavity, and the expansion cavity is used to reduce the flow resistance of the air flow; The exhaust structure includes a first baffle, a second baffle, a resonance pipe, an exhaust pipe, and a rear end cover arranged at the end of the muffler shell. The first partition plate, the second partition plate and the muffler shell form a fourth expansion chamber, and the second partition plate, the rear end cover and the muffler shell form a resonance chamber; The resonance tube includes a resonance tube perforated section and a resonance tube resonant section. The resonance tube perforated section is mounted on the first and second baffles. One end of the resonance tube perforated section extends to the outside of the fourth expansion chamber after passing through the first baffle. A plurality of first tube holes are spaced apart on a side wall of the resonance tube perforated section located in the fourth expansion chamber. The resonance tube resonant section is disposed in the resonance chamber, and an air outlet of the resonance tube resonant section is directly opposite to the valve structure on the second baffle. When the air flow velocity in the resonance pipe section of the resonance tube is greater than the preset flow velocity value, the valve structure automatically opens; when the air flow velocity in the resonance pipe section of the resonance tube is less than the preset flow velocity value, the valve structure automatically closes; The outlet pipe includes a perforated section and a curved section, wherein the air inlet end of the perforated section passes through the second partition plate and extends into the fourth expansion cavity; the air outlet end of the perforated section passes through the rear end cover and extends to the outside of the muffler housing and is connected to the curved section; A front end cover is mounted on one end of the muffler housing away from the exhaust structure, the air intake pipe is mounted on the front end cover, and a urea nozzle is also mounted on the front end cover, the urea nozzle is used to spray urea spray into the inner cavity of the muffler housing; The included angle between the air intake pipe and the air outlet direction of the urea nozzle is 15°.

2. A muffler that reduces both flow resistance and noise according to claim 1, characterized in that: The valve structure includes a circular cover and a torsion spring. The circular cover is rotatably connected to a surface of the second partition away from the rear end cover, and the torsion spring is sleeved on the rotating shaft of the circular cover.

3. The muffler according to claim 1, which is characterized by: The side wall of the perforated section of the air outlet pipe is wrapped with a resistive bag, in which a sound absorbing material is arranged. A plurality of second pipe holes are spaced apart on the side wall of the perforated section of the air outlet pipe in contact with the resistive bag.

4. The muffler according to claim 1, which is characterized by: One end of the resonance tube bend section away from the resonance tube perforated section abuts against the valve structure, a resonance tube fully perforated section is provided at the end of the resonance tube bend section, a plurality of circles of third tube holes are provided on the resonance tube fully perforated section, a cascade micro-perforated resonance cavity is provided on the outside of the resonance tube perforated section, a third partition is provided in the cascade micro-perforated resonance cavity, the cascade micro-perforated resonance cavity is divided into a plurality of chambers of different sizes by the third partition, a plurality of circles of micro-perforations are provided on the side wall of the resonance tube perforated section, and the size of the micro-perforations corresponds to the size of the chamber.

5. The muffler according to claim 2, which is characterized by: A rubber pad is provided on the side of the circular cover that contacts the second partition plate.

6. The muffler according to claim 1, which is characterized by: A catalytic converter is also provided in the middle of the inner cavity of the muffler shell, and the catalytic converter includes a first-stage catalytic converter and a second-stage catalytic converter arranged at intervals. The first-stage catalytic converter and the second-stage catalytic converter are provided with a porous ceramic carrier and coated with a precious metal catalyst. The first-stage catalytic converter and the second-stage catalytic converter are spaced a distance from each other and form a second expansion cavity with the muffler shell.

7. The muffler according to claim 1, which is characterized by: An eccentric cone structure is installed on one side of the inner cavity of the muffler shell close to the front end cover. The eccentric cone structure includes an eccentric cone. The eccentric cone is installed in the first ring through a first cross structure. The first ring is fixed on the inner wall of the muffler shell, and the tip of the eccentric cone is facing the outlet of the intake pipe.

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