Silencer and motorcycle

Abstract

An inner cylinder body and an outer cylinder body are at least partially installed in an interference fit mode, and the inner cylinder body and the outer cylinder body are designed in a sectional mode, so that compared with a conventional integral inner cylinder body structure, the overall length of the inner cylinder body is shortened, the expansion and contraction amount of the inner cylinder body due to thermal expansion and cold contraction is reduced, and the service life of the inner cylinder body is prolonged. The problem that the inner cylinder body is broken due to thermal expansion and cold contraction is solved, the risk of tension fracture at the connecting position of the inner cylinder body and the rear oxygen sensor is reduced, and the stability of the silencer is improved; the catalytic converter is arranged at the front position of the front section of the inner barrel and fixed through welding, so that the supporting strength of the catalytic converter is improved, the conversion efficiency of the catalytic converter is improved, the use cost is reduced, and the goal of green emission is achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to motorcycle engine technical field especially relates to a muffler and motorcycle. BACKGROUND

[0002] The muffler is an important component of the engine, which is used to reduce the noise generated by the engine, convert harmful components in the exhaust gas emitted by the engine into carbon dioxide and nitrogen, and thus improve the comfort of equipment use and reduce environmental pollution. Consumers' quality requirements for the muffler and emission requirements for the engine are continuously improving, thus promoting the development of muffler structure technology.

[0003] Compared with the traditional muffler, the existing muffler usually adopts impedance composite muffling principle, which combines the characteristics of resistive muffler and resistive muffler, has wider frequency noise reduction capability and better environmental protection adaptability, can realize efficient noise reduction in a wider frequency range, and create a quieter driving environment, but also has many deficiencies, such as the inner cylinder body is fixed by welding at both ends, which causes the inner cylinder body to change in length repeatedly for a long time due to thermal expansion and cold contraction, and the change frequency is relatively large, and the inner cylinder body is broken. Due to the different degrees of thermal expansion and cold contraction of the inner cylinder body, the outer cylinder body and the conduit of the catalytic converter, there is a risk of cracking at the welding position of the muffler inner cylinder body and the rear oxygen sensor. The catalytic converter is fixedly installed in the inner cylinder body by the partition plate, which cannot provide sufficient support strength, and the catalytic converter is far away from the engine exhaust port, the light-off temperature is not enough, which leads to low conversion efficiency of the catalytic converter and affects the emission.

[0004] Therefore, it is necessary to improve the structure of the existing muffler, which can not only avoid the cracking problem of the inner cylinder body of the muffler caused by thermal expansion and cold contraction, solve the cracking risk at the connection position of the muffler inner cylinder body and the rear oxygen sensor, but also optimize the installation position of the catalytic converter, which can not only increase the support strength of the catalytic converter and improve the stability of the device, but also improve the conversion efficiency of the catalytic converter, reduce the use cost, and realize the goal of green emission. SUMMARY

[0005] Therefore, the utility model aims at providing a muffler and motorcycle, which can not only avoid the cracking problem of the inner cylinder body of the muffler caused by thermal expansion and cold contraction, solve the cracking risk at the connection position of the muffler inner cylinder body and the rear oxygen sensor, but also optimize the installation position of the catalytic converter, which can not only increase the support strength of the catalytic converter and improve the stability of the device, but also improve the conversion efficiency of the catalytic converter, reduce the use cost, and realize the goal of green emission.

[0006] In order to achieve the purpose of the utility model, the utility model provides a muffler, which comprises an outer cylinder body and an inner cylinder body, and the inner cylinder body is installed at least partially through interference fit between the inner cylinder body and the outer cylinder body.

[0007] Further, the interference fit and fixed connection between the inner cylinder and the outer cylinder are achieved by a smooth curve transition section, which is a smooth curve transition intermediate piece or / and formed by deformation of the inner cylinder itself.

[0008] Further, the inner cylinder includes an inner cylinder front section and an inner cylinder rear section, and the inner cylinder rear section is interference fitted at least at one end with the outer cylinder.

[0009] Further, the rear end of the inner cylinder rear section is interference fitted with the outer cylinder by a smooth curve transition intermediate piece I, and the front end is welded and fixed with the outer cylinder by a smooth curve transition intermediate piece II.

[0010] Further, the rear end of the inner cylinder front section is welded to the outer cylinder by a smooth curve transition section of itself, and the front end is gradually necked and welded to the outer cylinder.

[0011] Further, the outer cylinder includes an outer cylinder front section and an outer cylinder rear section, and the front end of the outer cylinder rear section is butted and welded with the rear end of the inner cylinder front section.

[0012] The smooth curve transition intermediate piece II is a size head cylinder structure II, the large head section of which covers the butting position of the front end of the outer cylinder rear section and the rear end of the inner cylinder front section and is welded and fixed, and the small head section extends rearward to the front end inner circle of the inner cylinder rear section and is welded and fixed.

[0013] The smooth curve transition intermediate piece I is a size head cylinder structure I, the small head section of which is rearward and sleeved on the inner cylinder rear section and is welded and fixed, and the large head section is interference fitted with the outer cylinder rear section; or the small head section of the size head cylinder structure I is rearward and sleeved on the inner cylinder rear section and is interference fitted, and the large head section is welded and fixed with the outer cylinder rear section.

[0014] Further, the rear end of the outer cylinder front section is sleeved on the rear end of the inner cylinder front section and is welded and fixed, and the outer cylinder front section and the outer cylinder rear section are transitioned by an expansion joint and are welded and fixed.

[0015] Further, a catalytic converter is further included, which is located at a front position of the inner cylinder front section.

[0016] The inner cylinder front section and the outer cylinder front section are arranged in close contact with the catalytic converter, and corresponding sides form corresponding resonance cavities.

[0017] Further, the inner cylinder is divided into several resonance cavities by several partitions, and exhaust pipes, intake pipes and resonance pipes are arranged on corresponding supports of the several partitions, and the exhaust pipes, the intake pipes and the resonance pipes are supported on the corresponding partitions by interference fit.

[0018] The utility model discloses a motorcycle, including the muffler of the utility model discloses a motorcycle.

[0019] The utility model discloses a beneficial effect: a kind of muffler and motorcycle of the utility model, at least partial interference fit installation mode is used between inner cylinder and outer cylinder, and sectional design is carried out to inner cylinder and outer cylinder, compared with the overall inner cylinder structure of conventional, shorten the overall length of inner cylinder, reduce the telescopic amount of inner cylinder thermal expansion and contraction, solve the rupture problem caused by thermal expansion and contraction of inner cylinder, also reduce the risk of pulling crack existing in the connection position of inner cylinder and rear oxygen sensor, improve the stability of muffler;Catalytic converter is arranged at inner cylinder front section front position and is fixed by welding, increase the support strength of catalytic converter, improve the conversion efficiency of catalytic converter, reduce use cost, realize the goal of green emission. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is longitudinal section view of the muffler of the utility model along length direction;

[0021] Figure 2 It is Figure 1 Enlarged view of A in middle;

[0022] Figure 3 It is Figure 1 Enlarged view of B in middle;

[0023] Figure 4 It is Figure 1 Enlarged view of C in middle;

[0024] Figure 5 It is Figure 1 Longitudinal section view of D in middle;

[0025] Figure 6 It is structure schematic drawing of muffler.

[0026] Mark explanation: 1, outer cylinder;101, outer cylinder front section;1011, expansion joint on outer cylinder front section;102, outer cylinder rear section;2, inner cylinder;201, inner cylinder front section;2011, smooth curve transition section of inner cylinder front section itself;2012, expansion joint on inner cylinder front section;202, inner cylinder rear section;3, smooth curve transition intermediate piece;301, smooth curve transition intermediate piece I;302, smooth curve transition intermediate piece II;4, expansion joint;5, catalytic converter;6, baffle;7, exhaust pipe;8, rear oxygen sensor;9, intake pipe;10, resonance pipe. DETAILED DESCRIPTION

[0027] The following combines with attached Figures 1-6 Make further detailed description to the utility model.

[0028] The utility model discloses an embodiment of a kind of mufflers, including outer cylinder 1 and inner cylinder 2, the inner cylinder 2 and outer cylinder 1 between at least partial through interference fit to realize installation, the outer cylinder 1 has the effect of protection and sealing, prevent engine exhaust leakage, and provide support and fixed for inner cylinder 2, the material of outer cylinder 1 generally has better strength and corrosion resistance, to withstand the pressure inside muffler and external environment's erosion;The inner cylinder 2 is the core noise reduction component of muffler, usually adopt the design of perforation, so that exhaust gas can evenly enter each chamber inside inner cylinder 2, and simultaneously the outer cylinder 1 and inner cylinder 2 between can also fill sound-absorbing material, such as glass fiber or ceramic fiber etc., by the absorption effect of sound-absorbing material to sound wave, further reduce noise;Interference fit refers to the containment member, such as shaft etc., is loaded into the cooperation of containment member, such as hole etc., the actual interference of two after assembly is in the range of stipulation, make two parts tightly connected together, rely on the friction between cooperation surface to transmit torque or / and axial force a kind of assembly mode;The design of interference fit makes the inner cylinder 2 and outer cylinder 1 tightly connected, realize good sealing effect, avoid exhaust leakage inside muffler, simultaneously can effectively resist the impact force caused by vibration and noise generated when engine works, also can make the inner cylinder 2 due to thermal expansion and contraction in interference fit installation end realizes free expansion, avoid the rupture problem of inner cylinder 2 due to thermal expansion and contraction, prolong the service life of muffler, here no longer tediously.

[0029] In the embodiment, the interference fit and fixed connection between the inner cylinder 2 and the outer cylinder 1 are realized by the smooth curve transition section, the smooth curve transition section is a smooth curve transition intermediate piece 3 or / and is formed by deformation of the inner cylinder 2 itself, the fixed connection between the inner cylinder 2 and the outer cylinder 1 can adopt welding connection or bolt connection and the like in the prior art, and details are not repeated here; The smooth curve transition section can avoid sharp corners or abrupt changes at the welding position, so that the stress flow can flow more smoothly through the connection area, thereby further reducing the degree of stress concentration and avoiding the problems of crack propagation and structural damage caused by stress concentration; When the exhaust gas flows in the inner cylinder 2, the smooth curve transition section can make the exhaust gas flow more smoothly through the welding position, reduce the vortex and turbulence of the exhaust gas, not only reduce the flow resistance of the exhaust gas and improve the exhaust gas conveying efficiency, but also reduce the vibration and noise caused by the impact of the exhaust gas, which is conducive to the stable operation of the muffler; At the same time, compared with the traditional vertical cylinder wall, the smooth curve transition section can delay the thermal expansion and contraction of the inner cylinder 2, and avoid the rupture problem of the inner cylinder 2 caused by thermal expansion and contraction; The smooth curve transition intermediate piece 3 is usually a metal piece with a size head cylinder structure, which has the characteristics of connecting cylinder bodies with different diameters, adjusting the flow rate and pressure of the exhaust gas, adapting to the layout change of the cylinder body, and improving the stability of the connection structure, and details are not repeated here.

[0030] In the embodiment, the inner cylinder 2 comprises an inner cylinder front section 201 and an inner cylinder rear section 202, and the inner cylinder rear section 202 is in interference fit with at least one end of the outer cylinder 1, so as to divide the inner cylinder 2 into the inner cylinder front section 201 and the inner cylinder rear section 202. According to actual working conditions and performance requirements, different materials or different structural designs are adopted, for example, the inner cylinder front section 201 is closer to the air inlet and needs to bear higher pressure and flow rate, so a material with higher strength and better wear resistance is selected, while the inner cylinder rear section 202 pays more attention to cooperation with the outer cylinder 1 and reflection and absorption of sound waves, so a material with good acoustic performance or a special structure is designed to enhance the sound absorption effect. Separate processing can optimize the respective characteristics, improve the processing precision and production efficiency, and reduce the processing difficulty and cost. Meanwhile, the inner cylinder front section 201 and the inner cylinder rear section 202 are installed separately, which is more convenient than installing the whole inner cylinder 2, and improves the assembly accuracy and efficiency, which will not be described here. The interference fit makes the connection between the outer cylinder 1 and the inner cylinder 2 more compact, effectively inhibits the relative vibration and collision between the outer cylinder 1 and the inner cylinder 2, and reduces the noise and wear caused by vibration. If the inner cylinder 2 or the outer cylinder 1 is damaged, the interference fit connection method is relatively simple, and it is easier to operate when disassembling and replacing parts compared with some complex connection methods. Under the working condition of the engine, the inner cylinder 2 will expand due to temperature changes, and the interference fit can compensate for this thermal expansion difference to a certain extent. Through reasonable design of the interference amount, the outer cylinder 1 and the inner cylinder 2 can still maintain good connection performance and sealing performance under different temperature conditions.

[0031] In this embodiment, the rear end of the inner cylinder rear section 202 and the outer cylinder 1 are connected by the smooth curve transition intermediate piece I 301 to realize interference fit, and the front end is welded and fixed with the outer cylinder 1 by the smooth curve transition intermediate piece II 302. As shown in the figure, the rear end of the inner cylinder rear section 202 is provided with a smooth curve transition intermediate piece I 301, which is usually a metal piece with a size head cylinder structure. The large head section of the smooth curve transition intermediate piece I 301 is interference fit with the outer cylinder 1, and the small head section is outwardly sleeved on the inner cylinder rear section 202 and welded and fixed. This connection mode can effectively resist the vibration, impact and other external forces that occur during the operation of the muffler, prevent the loosening of the connection part, ensure the stability of the whole structure, and uniformly transfer the stress to the inner cylinder 2 and the outer cylinder 1, avoid stress concentration, help to prolong the service life of the muffler, and improve the reliability of the whole structure. In actual production, there will be certain size error between the outer cylinder 1 and the inner cylinder rear section 202, and the smooth curve transition intermediate piece I 301 can compensate for the size error by its own elastic deformation, so that the outer cylinder 1 and the inner cylinder rear section 202 can realize good fit, improve the processing technology of the parts and the success rate of assembly to a certain extent, and reduce the production cost. During installation, heating or cooling method can be used to make the smooth curve transition intermediate piece I 301 easier to install, which will not be described here. The front end of the inner cylinder rear section 202 is welded and fixed with the outer cylinder 1 by the smooth curve transition intermediate piece II 302, which further connects the inner cylinder 2 and the outer cylinder 1 into a whole, so that the whole structure can work cooperatively when bearing external force, and has better resistance to deformation and damage. Interference fit can reduce the relative movement between the inner cylinder 2 and the outer cylinder 1, inhibit the generation of vibration, and welding provides rigid connection, which can effectively transfer the vibration and impact load to the whole structure, avoid local stress concentration, and improve the stability and reliability of the structure under dynamic load. Interference fit forms a good sealing effect at the rear end of the inner cylinder rear section 202, which can prevent the internal medium from leaking from the rear end of the inner cylinder rear section 202. The welding of the front end of the inner cylinder rear section 202 can also ensure the sealing of the connection part, and the smooth curve transition intermediate piece I 301 and the smooth curve transition intermediate piece II 302 can reduce the flow resistance of the exhaust gas at the connection, reduce the erosion and corrosion of the connection part by the exhaust gas, and further improve the sealing performance.

[0032] In the embodiment, the rear end of the inner cylinder front section 201 is welded to the outer cylinder 1 through the smooth curve transition section 2011 of the inner cylinder front section 201 itself, and the front end is gradually necked and welded to the outer cylinder 1. The smooth curve transition section 2011 of the inner cylinder front section 201 itself can make the stress transmission between the inner cylinder front section 201 and the outer cylinder 1 more uniform, avoid stress concentration phenomenon, and improve the fatigue resistance and stability of the overall connection structure. The gradually necked design of the front end of the inner cylinder front section 201 makes the stress of the front end of the inner cylinder front section 201 gradually change. When external force is borne, the stress can be gradually transmitted and dispersed along the necked part, reducing the risk of excessive local stress, enhancing the connection strength, improving the structural rigidity, making the deformation of the whole structure smaller when stressed, and the like, which will not be described here.

[0033] In the embodiment, the outer cylinder 1 includes an outer cylinder front section 101 and an outer cylinder rear section 102. The front end of the outer cylinder rear section 102 is butted and welded with the rear end of the inner cylinder front section 201. The front end of the outer cylinder rear section 102 is butted and welded with the rear end of the inner cylinder front section 201, forming an integral whole. When external force is borne, the load can be borne together, avoiding local stress concentration caused by insecure connection, improving the strength and stability of the overall connection structure, preventing the leakage of exhaust gas in the muffler, and ensuring the normal operation of the muffler. Butting and welding make the stress transmission between the outer cylinder 1 and the inner cylinder 2 more uniform. When external load is received, the stress can be smoothly transmitted from the outer cylinder 1 to the inner cylinder 2 through the welded part, avoiding stress mutation, reducing the possibility of damage caused by stress concentration, and prolonging the service life of the muffler.

[0034] The smooth curve transition intermediate piece Ⅱ 302 is a size head cylindrical structure Ⅱ, the large head section of the size head cylindrical structure Ⅱ covers the front end of the rear section of the outer cylinder body 102 and the rear end of the front section of the inner cylinder body 201, and is welded and fixed, and the small head section extends to the front end inner circle of the rear section of the inner cylinder body 202 and is welded and fixed. This connection mode forms a firm overall connection between the outer cylinder body, the inner cylinder body and the intermediate piece, so that each part can work cooperatively, effectively avoids structural failure caused by local loosening, and improves the reliability and stability of the overall connection structure. The welding mode can provide high connection strength between parts, and when bearing tension, pressure and shear force, the welded part can reliably transfer load, ensuring the safe operation of the structure under complex working conditions. The smooth curve transition intermediate piece Ⅱ 302 has good elastic deformation capacity. When stress is generated in the muffler due to temperature change, pressure fluctuation and other factors during operation, the size head cylindrical structure Ⅱ of the smooth curve transition intermediate piece Ⅱ 302 can deform itself to absorb and disperse stress, disperse the concentrated stress along the smooth curve to a larger area, avoid stress concentration at the connection position, thereby reducing the risk of cracking at the position where the front end of the rear section of the outer cylinder body 102 and the rear end of the front section of the inner cylinder body 201 are connected and welded, and damage to the inner cylinder body 2 and the outer cylinder body 1. At the same time, the small head section of the size head cylindrical structure Ⅱ extends to the front end inner circle of the rear section of the inner cylinder body 202, so that the smooth curve transition intermediate piece Ⅱ 302 and the rear section of the inner cylinder body 202 form fixed connection, and the stability of the connection is enhanced. Hereinafter, the description is omitted.

[0035] The smooth curve transition intermediate piece 1301 is a size head cylindrical structure 101, the small head section of the size head cylindrical structure 101 is sleeved on the rear section of the inner cylinder body 202 and is welded and fixed, and the large head section is interference fit with the rear section of the outer cylinder body 102; or the small head section of the size head cylindrical structure 101 is sleeved on the rear section of the inner cylinder body 202 and is interference fit, and the large head section and the rear section of the outer cylinder body 102 are fixed by welding. In this embodiment, the small head section of the size head cylindrical structure 101 is sleeved on the rear section of the inner cylinder body 202 and is welded and fixed, which can provide reliable connection strength, ensure that the smooth curve transition intermediate piece 1301 and the rear section of the inner cylinder body 202 do not relatively displace during the operation of the muffler, the large head section of the size head cylindrical structure 101 is interference fit with the rear section of the outer cylinder body 102, so that the smooth curve transition intermediate piece 1301 and the rear section of the outer cylinder body 102 are closely combined, the friction force and the extrusion force generated by the interference amount are used to enhance the stability of the connection, which can effectively bear various forces generated during the operation of the equipment, such as pressure or vibration, and reduce the possibility of failure caused by loose connection; the smooth curve transition intermediate piece 1301 is helpful to reduce the stress concentration phenomenon, when the exhaust gas flows in the inner cylinder body 2 or the outer cylinder body 1 is subjected to external load during the operation of the muffler, the smooth curve can make the stress more evenly distributed on the overall structure, reduce the risk of local stress being too high, improve the reliability and safety of the overall structure, and prolong the service life of the muffler; of course, the small head section of the size head cylindrical structure 101 can be sleeved on the rear section of the inner cylinder body 202 and be interference fit, and the large head section and the rear section of the outer cylinder body 102 are fixed by welding, which has the same connection effect and will not be described here.

[0036] The rear end of the outer cylinder front section 101 is sleeved on the rear end of the inner cylinder front section 201 and is welded and fixed, the outer cylinder front section 101 and the outer cylinder rear section 102 are transitioned and welded and fixed through an expansion joint 4, the rear end of the outer cylinder front section 101 is sleeved on the rear end of the inner cylinder front section 201 and is welded and fixed, a larger welding contact area is formed, not only the connection strength between the outer cylinder 1 and the inner cylinder 2 is enhanced, a greater external force and internal pressure can be resisted, but also the sealing property of the structure is improved, the leakage of tail gas is effectively prevented; the sleeving and welding mode of the rear end of the outer cylinder front section 101 makes the stress transmission more uniform, the stress concentration phenomenon is avoided, when an external force acts, the stress can be more gently dispersed to the whole cylinder through the welding position, the risk of structure damage caused by excessive local stress is reduced, the service life of the muffler is prolonged, and details are not repeated here; usually the welding connection position is a weak area in the connection structure, stress concentration phenomenon is prone to occur when stressed, the expansion joint 4 can disperse the stress of the welding connection position to a larger area, avoid excessive stress concentration on the welding connection position, thereby reducing the risk of cracking of the welding connection position, increasing the rigidity of the connection, making the connection between the expansion joint 4 and the outer cylinder front section 101, the outer cylinder rear section 102 and the inner cylinder front section 201 more firm, better resisting external force, ensuring stability under complex working conditions, also enhancing the sealing property of the welding connection position, filling the tiny gap existing in the welding connection position, preventing tail gas from leaking to the external environment, ensuring normal operation of the muffler, the expansion joint 4 also has a protection effect, preventing liquid, gas and other corrosive media outside the muffler from entering the inside of the welding connection position, thereby slowing down the corrosion speed of the welding connection position, prolonging the service life of the muffler, and details are not repeated here.

[0037] In this embodiment, a catalytic converter 5 is also included, which is located at the front of the inner cylinder front section 201 and is used to convert harmful substances in the engine exhaust. The catalytic converter 5 usually contains noble metal catalysts such as platinum, palladium, or rhodium, which promote chemical reactions of carbon monoxide, hydrocarbons, and nitrogen oxides in the engine exhaust to convert them into harmless substances such as carbon dioxide, water, and nitrogen, thereby reducing environmental pollution. Since the temperature of the engine exhaust entering the muffler is relatively high, the inner cylinder front section 201 can maintain a high temperature, and the catalytic converter 5 can achieve the best catalytic effect within a certain temperature range. By placing the catalytic converter 5 at the front of the inner cylinder front section 201, the heat in the exhaust can be fully utilized, allowing the catalytic converter 5 to reach the working temperature more quickly and improving the conversion efficiency. The front end of the catalytic converter 5 is welded and fixed to the inner cylinder front section 201, and the rear end is connected to the connecting pipe inside the inner cylinder 1. The catalytic converter 5 covers the connection position of the connecting pipe and the inner cylinder front section 201 and is welded and fixed, forming an integral whole with the catalytic converter 5, the connecting pipe, and the inner cylinder front section 201, ensuring that there is no relative displacement or loosening between the components and increasing the connection strength. The connecting pipe and the inner cylinder front section 201 are connected through an expansion joint 2012, which is a smooth transition protrusion at the front of the inner cylinder front section 201. It has a protective effect, preventing liquid, gas, and other corrosive media outside the muffler from entering the welded connection position, thereby slowing down the corrosion rate of the welded connection position and prolonging the service life of the muffler. In this case, further description is omitted. The expansion joint 1011 is also provided on the outer cylinder front section 101, which can reduce the turbulence and vortex generated near the welded connection position, reducing the additional pressure impact on the welded connection position. At the same time, under the working conditions of the muffler, due to the influence of internal pressure, temperature changes, and external environment, various stresses are generated. The expansion joint 2012 and the expansion joint 1011 can change the stress distribution around the welded connection position, disperse the stress to a larger area, avoid stress concentration at the welded connection position, improve the strength and stability of the entire structure, and prevent cracking of the welded connection position or deformation of the inner cylinder 2 due to stress concentration;

[0038] The inner cylinder front section 201 and the outer cylinder front section 101 are arranged in close contact with the catalytic converter 5, and the corresponding side forms a corresponding resonance cavity. This design makes the integration of the overall structure higher, the connection between the components more compact and stable, helps to reduce the vibration and noise of the overall structure during operation, improves the stability and reliability of the overall structure, effectively utilizes the space, makes the muffler more compact, combines the catalytic converter 5 with the resonance cavity, reduces the overall size and floor area of the muffler, is convenient for installation and arrangement in limited space, also simplifies the installation and maintenance process, and reduces the maintenance cost; the resonance cavity can inhibit the influence of external interference on the catalytic conversion process to a certain extent. The resonance cavity serves as an acoustic or mechanical buffer zone, reduces the interference of external vibration, noise or other fluctuation factors on the internal reaction of the catalytic converter 5, makes the catalytic conversion process more stable and reliable, prolongs the service life of the catalytic converter 5, and details are not repeated here.

[0039] In the embodiment, the inner cylinder 2 is divided into several resonance cavities by the several partitions 6. The exhaust pipe 7, the intake pipe 9 and the resonance pipe 10 are arranged on the corresponding support of the several partitions 6. The exhaust pipe 7, the intake pipe 9 and the resonance pipe 10 are supported on the corresponding partition 6 by interference fit. The inner cylinder 2 is divided into several resonance cavities by the several partitions 6, which makes the structure of the inner cylinder 2 more stable and can withstand certain pressure and external force without being easily deformed. At the same time, the partitions 6 support the exhaust pipe 7, the intake pipe 9 and the resonance pipe 10, and the interference fit further enhances the stability of the connection, ensuring that the exhaust pipe 7, the intake pipe 9 and the resonance pipe 10 will not easily shake or fall off during the operation of the muffler, ensuring the stability and reliability of the overall structure, and also helping to improve the sealing between the exhaust pipe 7, the intake pipe 9 and the resonance pipe 10 and the corresponding partition 6, reducing the possibility of gas leakage. Dividing the inner cylinder 2 into multiple resonance cavities can guide the exhaust gas to flow along a specific path, making the flow of exhaust gas more stable, reducing the pressure fluctuation and turbulence of the airflow, reducing additional noise caused by unstable airflow, also helping to reduce the impact on the structure of the muffler, improving the reliability of the muffler and prolonging its service life. At the same time, according to different working requirements and frequency requirements, each resonance cavity is designed and optimized independently to achieve specific resonance functions and improve the performance of the muffler. In the prior art, the exhaust pipe 7 is arranged on the partition 6 away from the inner cylinder front section, and the intake pipe 9 and the resonance pipe 10 are arranged between the two adjacent partitions 6 in the inner cylinder rear section 202. Details are not repeated here. The intake pipe 9 refers to the exhaust pipe connected to the catalytic converter 5, and details are not repeated here. The resonance pipe 10 is connected between adjacent resonance cavities. When the exhaust gas flows between the resonance cavities, the resonance pipe 10 can cause vibration and disturbance of the exhaust gas, increase the contact area and contact time of the exhaust gas with the inner surface of the inner cylinder 2, and improve the sound attenuation effect.

[0040] In the embodiment, the inner cylinder body front section 201 is further provided with a rear oxygen sensor 8, which is mainly used for detecting the oxygen concentration in the exhaust gas treated by the catalytic converter 5, and will not be described here again; due to the segmented design of the outer cylinder body 1 and the inner cylinder body 2, compared with the traditional integral outer cylinder body 1 and inner cylinder body 2, the overall length of the outer cylinder body 1 and the inner cylinder body 2 is shortened by half, under the same working environment, according to the telescopic amount calculation formula, the telescopic rate of the inner cylinder body 2 is reduced by 50%, the telescopic amount of the inner cylinder body 2 due to thermal expansion and cold contraction is reduced, and therefore the risk of cracking of the rear oxygen sensor 8 and the inner cylinder body front section 201 is reduced, which will not be described here again.

[0041] The motorcycle of the embodiment includes the muffler, the inner cylinder body 2 and the outer cylinder body 1 are at least partially installed in an interference fit manner, and the inner cylinder body 2 and the outer cylinder body 1 are designed in a segmented manner, compared with the conventional integral inner cylinder body 2 structure, the overall length of the inner cylinder body 2 is shortened, the telescopic amount of the inner cylinder body 2 due to thermal expansion and cold contraction is reduced, the cracking problem of the inner cylinder body 2 caused by thermal expansion and cold contraction is solved, the cracking risk at the connection position of the inner cylinder body 2 and the rear oxygen sensor 8 is reduced, and the stability of the muffler is improved; the catalytic converter 5 is arranged at the front position of the inner cylinder body front section 201 and fixed by welding, the support strength of the catalytic converter 5 is increased, the conversion efficiency of the catalytic converter 5 is improved, the use cost is reduced, and the green emission goal is achieved.

[0042] Finally, it should be pointed out that the above embodiments are only used to illustrate the technical solutions of the present application and are not limiting, although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced equivalently without departing from the purpose and scope of the present application, and all should be covered in the scope of the claims of the present application.

Claims

1. A muffler characterized by: The muffler comprises an outer cylinder and an inner cylinder, and the inner cylinder is mounted with the outer cylinder by interference fit.

2. The muffler of claim 1, wherein: The interference fit and fixed connection between the inner cylinder and the outer cylinder are realized by a smooth curve transition section, which is a smooth curve transition intermediate piece or / and is formed by deformation of the inner cylinder itself.

3. The muffler of claim 1, wherein: The inner cylinder comprises an inner cylinder front section and an inner cylinder rear section, and the inner cylinder rear section is interference fitted with the outer cylinder at least at one end.

4. The muffler of claim 3, wherein: The rear end of the inner cylinder rear section is interference fitted with the outer cylinder by a smooth curve transition intermediate piece I, and the front end is welded and fixed with the outer cylinder by a smooth curve transition intermediate piece II.

5. The muffler of claim 3, wherein: The rear end of the inner cylinder front section is welded with the outer cylinder by a smooth curve transition section of itself, and the front end is gradually necked and welded with the outer cylinder.

6. The muffler of claim 4 or 5, characterized in that: The outer cylinder comprises an outer cylinder front section and an outer cylinder rear section, and the front end of the outer cylinder rear section is butted and welded with the rear end of the inner cylinder front section. The smooth curve transition intermediate piece II is a size head cylinder structure II, the large head section of which covers the butting position of the front end of the outer cylinder rear section and the rear end of the inner cylinder front section and is welded and fixed, and the small head section extends to the front end of the inner cylinder rear section and is welded and fixed. The smooth curve transition intermediate piece I is a size head cylinder structure I, the small head section of which is outwardly sleeved on the inner cylinder rear section and is welded and fixed, and the large head section is interference fitted with the outer cylinder rear section; or the small head section of the size head cylinder structure I is outwardly sleeved on the inner cylinder rear section and is interference fitted, and the large head section is welded and fixed with the outer cylinder rear section.

7. The muffler of claim 6, wherein: The rear end of the outer cylinder front section is outwardly sleeved on the rear end of the inner cylinder front section and is welded and fixed, and the outer cylinder front section and the outer cylinder rear section are transitioned by an expansion joint and are welded and fixed.

8. The muffler of claim 3, wherein: The muffler further comprises a catalytic converter, which is located at a front position of the inner cylinder front section. The inner cylinder front section and the outer cylinder front section are arranged in close contact with the catalytic converter, and corresponding sides form corresponding resonance cavities.

9. The muffler of claim 3, wherein: The inner cylinder is divided into several resonance cavities by several partitions, and exhaust pipes, intake pipes and resonance pipes are arranged on corresponding supports of the several partitions, and the exhaust pipes, the intake pipes and the resonance pipes are supported on the corresponding partitions by interference fit.

10. A motorcycle characterized by the fact that: The muffler comprises the muffler according to any one of claims 1-9.

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