CN106801637B - motorcycle cassette muffler - Google Patents

Abstract

The invention discloses a box-type muffler for motorcycles. Three partitions are arranged in the box-type shell to divide the inner cavity of the shell into four independent chambers, and the outlet end of the exhaust pipe communicates with the first chamber; There is a first throttling tube in the second chamber, and the first throttling tube communicates the first chamber and the third chamber; a throttling hole is arranged on the second partition to connect the second chamber and the third chamber Communication; a second throttling tube is provided in the third chamber, and the second throttling tube communicates the second chamber and the fourth chamber. A second box-type housing is provided on the side wall of the box-type housing, and the second box-type housing divides the inner cavity into a fifth chamber and a sixth chamber through a fourth partition; a throttle is provided on the fourth partition A hole is used to connect the fifth chamber with the sixth chamber; an exhaust port is provided on the shell wall of the sixth chamber; the fourth chamber communicates with the fifth chamber through the third throttling tube. The muffler can greatly reduce exhaust noise.

Description

motorcycle cassette muffler

technical field

The invention relates to the improvement of the structure of a motorcycle muffler, in particular to a box-type muffler for a motorcycle. The muffler can greatly reduce exhaust noise and belongs to the technical field of mufflers.

Background technique

Motorcycle muffler is a device that allows airflow to pass through to attenuate noise. The high-temperature exhaust gas emitted by motorcycle engine is directly discharged into the atmosphere after noise reduction and cooling through the muffler. It is one of the important parts on motorcycles. The performance of the muffler not only affects the noise of the motorcycle, but also has a great influence on the performance of the engine, such as power, fuel consumption, and torque.

According to different noise reduction principles, motorcycle mufflers can be divided into the following three types:

1. Resistive muffler: This kind of muffler uses the sound absorption effect of sound-absorbing materials or sound-absorbing structures to attenuate the noise propagating along the pipeline with distance, so as to achieve the purpose of noise reduction. Commonly used sound-absorbing materials include glass fiber wire, low-carbon steel wire mesh, felt, etc. This type of muffler has a good noise reduction effect on high-frequency noise, but poor noise reduction performance at low frequencies. In addition, because the sound-absorbing material is easily melted by the high-temperature exhaust gas discharged from the engine, the service life is short, and it is easy to be blocked by carbon deposits and sludge to reduce or lose the noise reduction effect, so a single resistive muffler is rarely used on motorcycles.

2. Resistant muffler: This kind of muffler relies on the sudden expansion (or contraction) of the pipe section or the side-connected resonant cavity, so that the sound waves of certain frequencies propagating along the pipe are reflected back to the direction of the sound source at the sudden change, so as to achieve the purpose of noise reduction . It is more suitable for eliminating low and intermediate frequency noise, but has a poor effect on high frequency noise.

3. Impedance composite muffler: This muffler is a combination of the muffler principle of resistive muffler and resistive muffler through proper structure, and has the muffler characteristics of both. Due to the wide frequency band of the noise generated by the noise source of the motorcycle engine, in order to obtain a better noise reduction effect in the wide frequency range of low, medium and high, most motorcycles use this impedance composite muffler, such as Nanya NY125, Honda CBX250, etc. all use this impedance composite muffler.

Motorcycle mufflers can be divided into two types: barrel muffler and box muffler according to the shape and structure.

1. Barrel muffler: Barrel mufflers are generally resistance or impedance composite mufflers, mostly used on medium and large displacement motorcycles. The barrel muffler is generally composed of several parts such as an exhaust pipe, a connecting screw sleeve, a muffler barrel and a barrel core. An oil-impregnated asbestos sealing ring is installed in the connecting screw sleeve to prevent air leakage at the interface between the exhaust pipe and the muffler. There are many partitions welded inside the muffler, which divide the muffler into multiple mufflers, and there are inverted triangular diversion grooves and many small holes on the core. When the high-temperature exhaust gas of the engine enters the muffler through the exhaust pipe at high speed, the cross-sectional area of the muffler gradually increases, the airflow expands, the flow velocity decreases, and the powerful pulsating noise is attenuated. When the air flow continues to flow through the expansion chambers, due to the obstruction of the partition, the air flow can only pass through the orifice on the partition and the barrel core, so the air flow is suddenly compressed, divided into many small streams, and then suddenly expanded, so With multiple mutations, the sound energy is greatly attenuated, thereby reducing exhaust noise.

2. Box-type muffler: Generally, mopeds, especially seat vehicles, use box-type mufflers because the installation space is relatively small. The box muffler is mainly composed of shell, sound-absorbing packing, muffler pipe and so on.

With the country's increasing requirements for environmental protection and energy saving, the demand for noise reduction of mufflers is more prominent. Although the sound reduction principles of the muffler are very mature at present, how to flexibly use these principles and how to improve the structure of the muffler to achieve better noise reduction and noise reduction effects has been the research direction of those skilled in the art.

Contents of the invention

Aiming at the above-mentioned deficiencies in the prior art, the object of the present invention is to provide a box-type muffler for motorcycles, which can greatly reduce exhaust noise.

In order to achieve the above object, the technical scheme adopted in the present invention is as follows:

A box-type muffler for motorcycles, including a box-type shell, in which three partitions parallel to each other are arranged along the length direction to divide the inner cavity of the shell into four independent chambers, which are the first chamber, The second chamber, the third chamber and the fourth chamber; the partition between the first chamber and the second chamber is the first partition; the partition between the second chamber and the third chamber is The second partition, the partition between the third chamber and the fourth chamber is the third partition; the outlet end of the exhaust pipe communicates with the first chamber; it is characterized in that: the second chamber is provided with a first A throttling tube, the two ends of the first throttling tube respectively pass through the first partition and the second partition to connect the first chamber and the third chamber; a throttling hole is arranged on the second partition to connect the second The chamber communicates with the third chamber; a second throttling tube is arranged in the third chamber, and the two ends of the second throttling tube respectively pass through the second partition and the third partition to connect the second chamber and the fourth chamber. The chamber is communicated; the second box-type casing is provided on the side wall of the box-type casing, and a fourth partition is arranged in the second box-type casing, and the fourth partition divides the inner cavity of the second box-type casing into a fifth chamber and a fifth chamber. The sixth chamber; an orifice is provided on the fourth partition to communicate the fifth chamber and the sixth chamber; an exhaust port is provided on the shell wall of the sixth chamber; the fourth chamber passes through the third The throttle tube communicates with the fifth chamber.

The first throttling tube and the third throttling tube are one, the second throttling tube is two different sizes, and the sum of the cross-sectional areas of the two second throttling tubes is equal to the cross-sectional area of the first throttling tube .

Further, the throttle holes on the second partition are two different in size, the two throttle holes on the second partition are located on the same side of the first throttle tube and arranged up and down, the two throttle holes on the second partition The sum of the hole areas is equal to the cross-sectional area of the first throttle tube.

Simultaneously, the throttling hole on the fourth partition is also two of different sizes and arranged up and down, and the exhaust port on the shell wall of the sixth chamber is equal in size and arranged up and down; the area of the two throttling holes on the fourth partition is The sum is equal to the cross-sectional area of the first throttle tube.

Preferably, the piercing positions of the two second throttle tubes on the second partition are located on the left and right sides of the piercing position of the first throttle tube, and the two throttle holes on the second partition are located between the first throttle tube and the first throttle tube. between one of the second throttle tubes.

The two throttle holes on the fourth separator are correspondingly equal to the two throttle holes on the second separator; the area of the large throttle hole is 2-3 times that of the small throttle hole.

Among the two second throttling tubes, the cross-sectional area of the large tube is 2-3 times that of the small tube, and is respectively equal to the size of the two throttle holes on the second separator.

The air flow direction of the muffler of the present invention: the exhaust gas from the exhaust pipe first enters the first chamber, and then enters the third chamber through the first throttle pipe; the air flow in the third chamber enters through the two throttle holes on the second partition plate The second chamber enters the fourth chamber through two second throttle tubes, then enters the fifth chamber through the third throttle tube, and then enters the sixth chamber through the throttle hole on the fourth partition, Finally, it is discharged from the exhaust port. In the circulation process of each chamber, throttling tubes, throttling holes, or sudden changes in the dimension of the chamber are used, resulting in contraction and expansion effects.

In the process of entering the second chamber from the third chamber, the sound wave propagating along the pipeline is deliberately designed to reflect back to the direction of the sound source, and the size of the third chamber and the passage of the first throttle tube into the third chamber are pre-designed. Length, so that the sound wave propagating from the first chamber into the third chamber through the first throttle tube and the sound wave reflected from the third chamber into the second chamber have a phase difference of 180 degrees, so that the amplitude of the two is equal and the phase is opposite , interfere with each other and cancel each other to achieve the ideal noise reduction effect. Finally, the resonance cavity (fifth chamber) is bypassed. When the airflow passes through the tube hole and enters the resonance cavity, the cross-sectional area suddenly increases, the airflow expands, the flow velocity decreases, and the powerful pulsation noise is attenuated. When the airflow continues to flow through the expansion chamber (the sixth chamber), due to the obstruction of the fourth partition, the airflow can only pass through the orifice on the partition, so the airflow is suddenly compressed and divided into many small streams, and then suddenly It can be expanded, and the sound energy is greatly attenuated, thereby reducing the exhaust noise. Therefore, through the above design, the noise from the muffler is greatly reduced, thereby achieving a rational noise reduction effect.

Description of drawings

Figure 1 - a schematic diagram of the internal structure of the present invention.

Fig. 2 - the external three-dimensional structure diagram of the present invention.

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings.

Referring to Fig. 1 and Fig. 2, as can be seen from the figure, the box-type muffler for motorcycle of the present invention comprises a box-type casing 1, and in the box-type casing 1, three partitions parallel to each other are provided along the length direction so that the casing inner cavity Divided into four independent chambers, followed by the first chamber 2, the second chamber 3, the third chamber 4 and the fourth chamber 5; the partition between the first chamber 2 and the second chamber 3 The plate is the first partition 6; the partition between the second chamber 3 and the third chamber 4 is the second partition 7, and the partition between the third chamber 4 and the fourth chamber 5 is the third The partition 8; the outlet end of the exhaust pipe 9 communicates with the first chamber 2; the second chamber 3 is provided with a first throttle tube 10, and the two ends of the first throttle tube 10 respectively pass through the first partition 6 The first chamber 2 and the third chamber 4 are communicated with the second partition 7; the second partition 7 is provided with an orifice 11 to communicate the second chamber 3 with the third chamber 4; The third chamber 4 is provided with a second throttling tube 12 , and the two ends of the second throttling tube 12 respectively pass through the second partition 7 and the third partition 8 to connect the second chamber 3 and the fourth chamber 5 . A second box-type housing 13 is provided on the side wall of the box-type housing 1, and a fourth partition 14 is arranged inside the second box-type housing 13, and the fourth partition 14 divides the inner cavity of the second box-type housing into a fifth cavity Chamber 15 and the sixth chamber 16; a throttle hole 11 is provided on the fourth partition 14 to communicate the fifth chamber 15 and the sixth chamber 16; an exhaust gas is provided on the shell wall of the sixth chamber 16 Port 17; the fourth chamber 5 communicates with the fifth chamber 15 through the third throttling tube 18.

In the structural design of the muffler of the present invention, it breaks through the inherent design of the traditional muffler that the air flow has been transmitted forward, that is, a foldback structure is designed, that is, the air flow from the third chamber does not enter the fourth chamber forward, but reflects into the second chamber. The cavity is deliberately designed to reflect the sound wave propagating along the pipeline back to the direction of the sound source. At the same time, the size of the third cavity and the length of the first throttle tube entering the third cavity are pre-designed so that the first cavity passes through the first cavity. The sound wave transmitted by the throttling tube into the third chamber and the sound wave reflected by the third chamber into the second chamber have a phase difference of 180 degrees, so that the amplitude of the two is equal, the phase is opposite, and they interfere with each other and cancel each other to achieve ideal noise reduction. Effect.

At the same time, the second box-type casing is bent and arranged on the side wall of the box-type casing, which is equivalent to turning the airflow flowing forward by 90° to enter the third throttle tube, and this structure can also strengthen the attenuation of the airflow.

Wherein the first throttling tube 10 and the third throttling tube 18 are one, the second throttling tube 12 is two different in size, and the sum of the cross-sectional areas of the two second throttling tubes 12 is the same as that of the first throttling tube. The cross-sectional areas of the tubes 10 are equal. There are two second throttling tubes of the present invention with different sizes, the purpose is to make the air flow interfere with each other, and achieve a better attenuation effect when the air flow passes than when the throttling tubes are the same.

Further, the throttle holes 11 on the second partition are two different in size, and the two throttle holes 11 on the second partition are located on the same side of the first throttle tube 10 and are arranged up and down. The sum of the areas of the two throttle holes 11 is equal to the cross-sectional area of the first throttle tube 10 . The size of the two orifices on the separator of the present invention is different, the purpose is to make the air flow interfere with each other, and at the same time, because the sound wave lines have different wavelengths, the sound of different frequencies can be eliminated by one large and one small, and when the air flow passes through, it can reach the same frequency as the orifice. At the same time better attenuation effect. Simultaneously, the throttling holes 11 on the fourth dividing plate are also two of different sizes and arranged up and down, and the exhaust ports 17 on the shell wall of the sixth chamber are equal in size and arranged up and down; the two throttling holes on the fourth dividing plate The sum of the areas of the holes 11 is equal to the cross-sectional area of the first throttle tube 10 .

Preferably, the penetration positions of the two second throttle tubes 12 on the second partition plate 7 are located on the left and right sides of the penetration position of the first throttle tube 10, and the two throttle holes 11 on the second partition plate are located on the first between the throttle tube 10 and one of the second throttle tubes 12 .

The two throttle holes on the fourth separator are correspondingly equal to the two throttle holes on the second separator; the area of the large throttle hole is 2-3 times that of the small throttle hole.

Among the two second throttling tubes, the cross-sectional area of the large tube is 2-3 times that of the small tube, and is respectively equal to the size of the two throttle holes on the second separator. When the size difference between the two throttling tubes and the two throttling holes is too large, the required interference effect cannot be achieved. The certification shows that when the cross-sectional area of the large pipe (hole) is 2-3 times that of the small pipe (hole), Interference attenuation works best.

The air flow direction of the muffler of the present invention: the exhaust gas from the exhaust pipe 9 first enters the first chamber 2, and then enters the third chamber 4 through the first throttle pipe 10; the air flow of the third chamber 4 passes through the second partition plate 7 The two throttle holes 11 enter the second chamber 3, then enter the fourth chamber 5 through two second throttle tubes 12, then enter the fifth chamber 15 through the third throttle tube 18, and then pass through the fourth compartment The orifice 11 on the plate 14 enters the sixth chamber 16 and is finally discharged by the exhaust port 17 . In the process of circulation in each chamber, throttle tubes, throttle holes, or sudden changes in the cavity are used, and there are contraction shunt and expansion attenuation effects.

Specifically, when the airflow enters the first chamber through the exhaust pipe, the cross-sectional area increases, and the airflow expands and attenuates; when the airflow enters the first throttling tube, it is compressed and divided into many small streams; it enters the third chamber through the first throttling tube When entering the chamber, the airflow expands again and is reflected back to the second chamber through the orifice on the second partition; when entering the orifice, the airflow is divided into many small streams; it enters through the orifice on the second partition In the second chamber, the cross-sectional area increases, and the airflow expands and attenuates; when the airflow in the second chamber enters the fourth chamber through the second throttle tube, the airflow is compressed and divided into many small streams because of the second throttle tube. At the moment of entering the fourth chamber, the cross-sectional area increases, and the airflow expands and attenuates again; then enters the fifth chamber through the third throttling tube, and repeats the process of compression split and expansion attenuation; the airflow enters the sixth chamber through the fifth chamber, Under the action of the diaphragm orifice, the process of compression, diversion and expansion and attenuation is carried out. In this way, after multiple compression and diversion and expansion and attenuation, the sound wave energy is greatly attenuated, and finally the ideal purpose of noise reduction and noise reduction is achieved.

The above-mentioned embodiments of the present invention are only examples for illustrating the present invention, rather than limiting the implementation of the present invention. For those of ordinary skill in the art, other variations and modifications in various forms can be made on the basis of the above description. All the implementation manners cannot be exhaustively listed here. All obvious changes or changes derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims (6)

1. Motorcycle box-type muffler, including a box-type shell, inside the box-type shell, there are three partitions parallel to each other along the length direction to divide the inner cavity of the shell into four independent chambers, which are the first chamber, The second chamber, the third chamber and the fourth chamber; the partition between the first chamber and the second chamber is the first partition; the partition between the second chamber and the third chamber is The second partition, the partition between the third chamber and the fourth chamber is the third partition; the outlet end of the exhaust pipe communicates with the first chamber; it is characterized in that: the second chamber is provided with a first A throttling tube, the two ends of the first throttling tube respectively pass through the first partition and the second partition to connect the first chamber and the third chamber; a throttling hole is arranged on the second partition to connect the second The chamber communicates with the third chamber; a second throttling tube is arranged in the third chamber, and the two ends of the second throttling tube respectively pass through the second partition and the third partition to connect the second chamber and the fourth chamber. The chamber is communicated; the second box-type casing is provided on the side wall of the box-type casing, and a fourth partition is arranged in the second box-type casing, and the fourth partition divides the inner cavity of the second box-type casing into a fifth chamber and a fifth chamber. The sixth chamber; an orifice is provided on the fourth partition to communicate the fifth chamber and the sixth chamber; an exhaust port is provided on the shell wall of the sixth chamber; the fourth chamber passes through the third The throttle tube communicates with the fifth chamber; Both the first throttling tube and the third throttling tube are one, the second throttling tubes are two of different sizes, and the sum of the cross-sectional areas of the two second throttling tubes is equal to the cross-sectional area of the first throttling tube; The size of the third chamber and the length of the first throttling tube entering the third chamber meet the following requirements: the sound wave that the first chamber enters the third chamber through the first throttling tube is reflected by the third chamber and enters the third chamber The sound waves of the two chambers are 180° out of phase, so that the two chambers have equal amplitudes and opposite phases. 2. The box-type muffler for motorcycle according to claim 1, characterized in that: the throttle holes on the second partition are two different in size, and the two throttle holes on the second partition are located at the first throttling hole. The tubes are arranged on the same side and up and down, and the sum of the areas of the two throttle holes on the second partition is equal to the cross-sectional area of the first throttle tube. 3. The box-type muffler for motorcycles according to claim 2, characterized in that: the orifice on the fourth partition is two different in size and arranged up and down, and the size of the exhaust port on the shell wall of the sixth chamber is equal and set up and down; the sum of the areas of the two throttle holes on the fourth separator is equal to the cross-sectional area of the first throttle tube. 4. The box-type muffler for motorcycles according to claim 2, characterized in that: the piercing positions of the two second throttle pipes on the second partition are located on the left and right sides of the piercing position of the first throttle pipe, and the piercing positions of the second throttle pipe The two throttle holes on the second partition are located between the first throttle tube and one of the second throttle tubes. 5. The motorcycle cassette muffler according to claim 3, characterized in that: the two throttle holes on the fourth partition are correspondingly equal to the two throttle holes on the second partition; wherein the area of the large throttle hole is 2-3 times the area of the small orifice. 6. The cassette muffler for motorcycle according to claim 2, characterized in that: in the two second throttle pipes, the cross-sectional area of the large pipe is 2-3 times the cross-sectional area of the small pipe, and is connected with the second partition respectively The size of the two orifices on the corresponding is equal.

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