阅读说明：本技术 车辆排气降噪方法、装置、后消声装置及消声器 (Vehicle exhaust noise reduction method and device, rear noise elimination device and silencer ) 是由 翟旭茂 侯绍行 李玉娟 陈志响 王子敬 于 2020-12-01 设计创作，主要内容包括：本发明实施例提供一种车辆排气降噪方法、装置、后消声装置及消声器,该装置包括：蝶阀和控制器；所述蝶阀包括蝶板和动力单元；所述动力单元与所述控制器通信连接；所述蝶板设于后消声装置的排气尾管中,所述蝶板对应的水平面与所述排气尾管的尾气流向垂直；所述控制器用于确定工况排气信息并根据所述工况排气信息生成对应的控制指令,将所述控制指令发送至所述动力单元；所述动力单元用于根据所述控制指令驱动所述蝶板在所述排气尾管中进行对应角度的旋转。本发明实施例的装置可以根据车辆工况改变排气尾管中尾气的流速,进而实现在不同工况下的车辆排气降噪。(The embodiment of the invention provides a vehicle exhaust noise reduction method, a vehicle exhaust noise reduction device, a rear noise elimination device and a muffler, wherein the device comprises: a butterfly valve and a controller; the butterfly valve comprises a butterfly plate and a power unit; the power unit is in communication connection with the controller; the butterfly plate is arranged in a tail pipe of the rear silencer, and the horizontal plane corresponding to the butterfly plate is vertical to the tail gas flow direction of the tail pipe; the controller is used for determining working condition exhaust information, generating a corresponding control instruction according to the working condition exhaust information, and sending the control instruction to the power unit; and the power unit is used for driving the butterfly plate to rotate in the tail pipe by a corresponding angle according to the control command. The device provided by the embodiment of the invention can change the flow velocity of tail gas in the tail pipe according to the working conditions of the vehicle, thereby realizing the noise reduction of the vehicle exhaust under different working conditions.)

1. A vehicle exhaust noise reduction device, comprising: a butterfly valve and a controller;

the butterfly valve comprises a butterfly plate and a power unit; the power unit is in communication connection with the controller; the butterfly plate is arranged in a tail pipe of the rear silencer, and the horizontal plane corresponding to the butterfly plate is vertical to the tail gas flow direction of the tail pipe;

the controller is used for determining working condition exhaust information, generating a corresponding control instruction according to the working condition exhaust information, and sending the control instruction to the power unit;

and the power unit is used for driving the butterfly plate to rotate in the tail pipe by a corresponding angle according to the control command.

2. The apparatus of claim 1, wherein the controller, when determining operating condition exhaust information, is specifically configured to:

the method comprises the steps of obtaining engine operation parameter data of a target vehicle, and determining working condition exhaust information according to the engine operation parameter data.

3. The apparatus of claim 1 or 2, wherein the control command is an increase flow rate control command or a decrease flow rate control command; the working condition exhaust information is any one of medium-speed working condition information, high-speed working condition information, rapid acceleration working condition information, idling working condition information or low-speed working condition information;

when the controller generates a control instruction according to the working condition exhaust information, the controller is specifically configured to:

if the working condition exhaust information is intermediate-speed working condition information, high-speed working condition information or rapid acceleration working condition information, generating a flow speed reduction control instruction according to the working condition exhaust information;

and if the working condition exhaust information is idle working condition information or low-speed working condition information, generating a flow rate increasing control instruction according to the working condition exhaust information.

4. The device of claim 1, wherein the butterfly valve further comprises: a fixed ring and a butterfly rod; the power unit is positioned at the upper part of the fixed ring;

the tail pipe penetrates through the fixing ring, and the butterfly rod penetrates through the tail pipe and extends to the butterfly plate;

the power unit is specifically used for driving the butterfly rod to rotate in the tail pipe by a corresponding angle according to the control command, so that the butterfly plate rotates by the corresponding angle.

5. A method of reducing noise in a vehicle exhaust, the method comprising:

the controller determines working condition exhaust information, generates a control instruction according to the working condition exhaust information, and sends the control instruction to the power unit;

and the power unit drives the butterfly plate to rotate in the tail pipe by a corresponding angle according to the control command.

6. A rear muffler device, characterized by comprising the vehicle exhaust noise reduction device according to any one of claims 1 to 4 and a tail pipe;

the vehicle exhaust noise reduction device is fixedly connected with the tail pipe.

7. The rear muffler assembly of claim 6, further comprising: a perforated pipe;

the air outlet end of the perforated pipe is connected with the air inlet end of the tail pipe;

the perforated pipe surface is covered with a plurality of perforations, and no perforations are present on the surface of the area of the preset length close to the tail pipe.

8. The rear muffler assembly of claim 7, further comprising: the device comprises a shell, a partition plate, a tail plate and an air inlet pipe;

the front end of the shell is provided with the partition plate, the rear end of the shell is provided with the tail plate, and the air inlet pipe penetrates through the partition plate and extends into the shell;

the perforated pipe is arranged between the clapboard and the tail plate; the tail pipe is arranged outside the shell; the air outlet end of the perforated pipe penetrates through the tail plate and is connected with the air inlet end of the tail pipe.

9. The rear muffler assembly of claim 8, wherein the tail plate is a perforated plate;

the apparatus further comprises a sound absorbing material; the sound absorption material is filled between the tail plate and the shell.

10. An integrated catalytic conversion muffler, comprising a pre-muffler treatment device, an intermediate carrier portion and a post-muffler device as claimed in any one of claims 6 to 9;

the pre-silencing treatment device is connected with the rear silencing device through the middle carrier part.

Technical Field

The embodiment of the invention relates to the technical field of vehicle noise reduction, in particular to a vehicle exhaust noise reduction method and device, a rear muffler device and a muffler.

Background

With the continuous development of vehicles, how to reduce the noise of automobiles is the focus of vehicle research nowadays. During the daily running of the vehicle, exhaust noise is an important noise source influencing the passing noise of the whole vehicle, and the proportion of the exhaust noise in the passing noise is about 30-40%.

In order to solve the problem of exhaust noise of vehicles, noise reduction treatment is mainly performed through an integrated catalytic conversion muffler at present. The integrated catalytic conversion muffler is an integrated body of a catalytic converter and an engine exhaust muffler and comprises a noise elimination pre-treatment device, an intermediate carrier part and a rear noise elimination device, wherein the noise elimination post-treatment device has poor exhaust noise reduction effect and cannot give consideration to the exhaust noise problems under different working conditions.

Therefore, the existing rear silencer has poor noise reduction effect.

Disclosure of Invention

The invention provides a vehicle exhaust noise reduction method and device, a rear muffler device and a muffler, which are used for solving the problem of poor noise reduction effect of the conventional rear muffler device.

A first aspect of an embodiment of the present invention provides a vehicle exhaust noise reduction device, including: a butterfly valve and a controller;

the butterfly valve comprises a butterfly plate and a power unit; the power unit is in communication connection with the controller; the butterfly plate is arranged in a tail pipe of the rear silencer, and the horizontal plane corresponding to the butterfly plate is vertical to the tail gas flow direction of the tail pipe;

the controller is used for determining working condition exhaust information, generating a corresponding control instruction according to the working condition exhaust information, and sending the control instruction to the power unit;

and the power unit is used for driving the butterfly plate to rotate in the tail pipe by a corresponding angle according to the control command.

Further, in the apparatus described above, the controller, when determining the operating condition exhaust information, is specifically configured to:

the method comprises the steps of obtaining engine operation parameter data of a target vehicle, and determining working condition exhaust information according to the engine operation parameter data.

Further, the device as described above, the control command is an increase flow rate control command or a decrease flow rate control command; the working condition exhaust information is any one of medium-speed working condition information, high-speed working condition information, rapid acceleration working condition information, idling working condition information or low-speed working condition information;

when the controller generates a control instruction according to the working condition exhaust information, the controller is specifically configured to:

if the working condition exhaust information is intermediate-speed working condition information, high-speed working condition information or rapid acceleration working condition information, generating a flow speed reduction control instruction according to the working condition exhaust information;

and if the working condition exhaust information is idle working condition information or low-speed working condition information, generating a flow rate increasing control instruction according to the working condition exhaust information.

Further, according to the above device, the butterfly valve further comprises: a fixed ring and a butterfly rod; the power unit is positioned at the upper part of the fixed ring;

the tail pipe penetrates through the fixing ring, and the butterfly rod penetrates through the tail pipe and extends to the butterfly plate;

the power unit is specifically used for driving the butterfly rod to rotate in the tail pipe by a corresponding angle according to the control command, so that the butterfly plate rotates by the corresponding angle.

A second aspect of an embodiment of the present invention provides a vehicle exhaust noise reduction method, including:

the controller determines working condition exhaust information, generates a control instruction according to the working condition exhaust information, and sends the control instruction to the power unit;

and the power unit drives the butterfly plate to rotate in the tail pipe by a corresponding angle according to the control command.

A third aspect of an embodiment of the present invention provides a rear muffler device, including the vehicle exhaust noise reduction device according to any one of the first aspect and a tail pipe;

the vehicle exhaust noise reduction device is fixedly connected with the tail pipe.

Further, the apparatus as described above, further comprising: a perforated pipe;

the air outlet end of the perforated pipe is connected with the air inlet end of the tail pipe;

the perforated pipe surface is covered with a plurality of perforations, and no perforations are present on the surface of the area of the preset length close to the tail pipe.

Further, the apparatus as described above, further comprising: the device comprises a shell, a partition plate, a tail plate and an air inlet pipe;

the front end of the shell is provided with the partition plate, the rear end of the shell is provided with the tail plate, and the air inlet pipe penetrates through the partition plate and extends into the shell;

the perforated pipe is arranged between the clapboard and the tail plate; the tail pipe is arranged outside the shell; the air outlet end of the perforated pipe penetrates through the tail plate and is connected with the air inlet end of the tail pipe.

Further, in the above-described apparatus, the end plate is a perforated plate;

the apparatus further comprises a sound absorbing material; the sound absorption material is filled between the tail plate and the shell.

The fourth aspect of the embodiment of the invention provides an integrated catalytic conversion muffler, which comprises a pre-muffling treatment device, an intermediate carrier part and the rear muffling device of any one of the third aspect;

the pre-silencing treatment device is connected with the rear silencing device through the middle carrier part.

The embodiment of the invention provides a vehicle exhaust noise reduction method, a vehicle exhaust noise reduction device, a rear noise elimination device and a muffler, wherein the device comprises: a butterfly valve and a controller; the butterfly valve comprises a butterfly plate and a power unit; the power unit is in communication connection with the controller; the butterfly plate is arranged in a tail pipe of the rear silencer, and the horizontal plane corresponding to the butterfly plate is vertical to the tail gas flow direction of the tail pipe; the controller is used for determining working condition exhaust information, generating a corresponding control instruction according to the working condition exhaust information, and sending the control instruction to the power unit; and the power unit is used for driving the butterfly plate to rotate in the tail pipe by a corresponding angle according to the control command. The device of the embodiment of the invention determines the working condition exhaust information through the controller, and then generates the corresponding control instruction according to the working condition exhaust information, and the generated corresponding control instruction can correspondingly change because the working condition exhaust information changes along with the change of the working condition of the vehicle. A power unit in the device can drive the butterfly plate to rotate in the tail pipe by a corresponding angle according to a control instruction, so that the flow speed of tail gas in the tail pipe can be changed according to the working condition of the vehicle, and the noise reduction of the vehicle exhaust under different working conditions is realized.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention.

FIG. 1 is a schematic structural diagram of a vehicle exhaust noise reduction device according to a first embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a butterfly valve in a vehicle exhaust noise reduction device according to a second embodiment of the present invention;

FIG. 3 is a schematic flow chart illustrating a method for reducing noise in exhaust of a vehicle according to a third embodiment of the present invention;

fig. 4 is a schematic structural view of a rear muffler device according to a fourth embodiment of the present invention;

fig. 5 is a schematic structural view of a rear muffler device according to a fifth embodiment of the present invention;

fig. 6 is a schematic view of an optimized structure of a perforated pipe of a rear muffler device according to a fifth embodiment of the present invention;

fig. 7 is a schematic structural diagram of an integrated catalytic conversion muffler according to a sixth embodiment of the present invention.

Description of the symbols:

10-a controller; 20-a butterfly valve; 21-a power unit; 22-a butterfly plate; 23-a butterfly rod; 24-a retaining ring; 210-vehicle exhaust noise reduction device; 220-tail pipe; 230-a housing; 240-partition plate; 250-a tail plate; 260-perforated tubes; 270-an air inlet pipe; 280-sound absorbing material; 310-a silencing pretreatment device; 320-an intermediate carrier moiety; 330-rear muffler device.

With the above figures, certain embodiments of the invention have been illustrated and described in more detail below. The drawings and the description are not intended to limit the scope of the inventive concept in any way, but rather to illustrate it by those skilled in the art with reference to specific embodiments.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the invention, as detailed in the appended claims.

The technical solution of the present invention will be described in detail below with specific examples. The following several specific embodiments may be combined with each other, and details of the same or similar concepts or processes may not be repeated in some embodiments. Embodiments of the present invention will be described below with reference to the accompanying drawings.

To facilitate understanding of the technical solutions of the present application, the following related technical terms are first introduced:

transmission loss: the attenuation of sound energy, i.e., the difference between the incident sound power level and the transmitted sound power level, after sound passes through the attenuating element.

Expansion ratio: the diameter of the muffler expansion chamber is greater than the diameter of the pipe.

Sweeping flow: the flow of fluid through the perforated pipe muffler sweeps primarily over one side of the perforations.

Passing through a flow: the flow of a cross-flow perforated pipe muffler is a through-flow, with the fluid being perforated from the inlet pipe diameter upstream into the muffler cavity and then through the downstream perforations to the outlet pipe.

Meanwhile, in order to more clearly understand the technical solution of the present application, the following detailed description is made on the prior art solution. With the continuous development of vehicles, how to reduce the noise of automobiles is the focus of vehicle research nowadays. Whether it is a fuel vehicle, a new energy vehicle or a hybrid vehicle, during the daily running of the vehicle, exhaust noise is an important noise source affecting the passing noise of the whole vehicle, especially a vehicle using a natural gas engine, and the proportion of the exhaust noise in the passing noise is larger.

In order to solve the problem of exhaust noise of vehicles, noise reduction treatment is mainly performed through an integrated catalytic conversion muffler at present. The integrated catalytic conversion silencer is an integrated body of a catalytic converter and an engine exhaust silencer, and comprises a silencing pre-treatment device, an intermediate carrier part and a post-silencing device, wherein the silencing post-treatment device is used for performing exhaust and noise reduction in the same mode under various vehicle working conditions, such as idling working condition information, low-speed working condition information, medium-speed working condition, high-speed working condition or rapid acceleration working condition, and the ratio of the diameter of an expansion cavity of the silencer to the diameter of a pipeline of an exhaust tail pipe is fixed. Therefore, the noise reduction effect is poor under various working conditions.

Therefore, aiming at the technical problem that the noise reduction effect of the rear silencer in the prior art is poor under various working conditions, the inventor finds that the tail pipe noise is composed of two parts: air noise and air flow friction noise. The steady air flow gives off air noise at the tailpipe, while the unsteady air flow produces frictional noise. When the flow rate in the tail pipe is small and the speed is low, air noise is the main component, and when the flow rate is large and the flow speed is high, friction noise is the main component.

The flow Q in the pipeline depends on the sectional area A and the flow speed u of the pipeline, and the expression is as follows:

Q＝uA

for a round pipe, the fluid velocities are:

u＝4Q/πd²

wherein d is the diameter of the round tube. From the calculation formula, the fluid velocity is proportional to the flow rate and inversely proportional to the square of the pipe diameter. Under idle and low speed operating conditions, friction noise has little effect on tailpipe noise, which is determined entirely by air noise, the magnitude of which is directly related to the expansion ratio. The larger the expansion ratio, the larger the acoustic transmission loss, and the smaller the tailpipe noise, i.e., the smaller the tailpipe diameter, the larger the flow velocity, and the lower the tailpipe noise. Under the working conditions of medium and high speed and the working condition of rapid acceleration through noise test, the flow in the pipeline is rapidly increased, the flow velocity is also rapidly increased, and at the moment, the friction noise plays a leading role. The larger the pipe diameter, the lower the flow velocity and, thus, the smaller the frictional noise.

Therefore, the inventor thinks that the ratio of the diameter of the expansion cavity of the silencer to the approximate pipe diameter of the tail pipe can be changed by changing the flow speed of the tail pipe in the running process of the vehicle and blocking the tail gas with different degrees by rotating the butterfly valve, namely the expansion ratio is changed according to the working conditions of the vehicle, so that the corresponding exhaust noise reduction of the vehicle under different working conditions is realized. Specifically, a butterfly valve is arranged on the tail pipe, then the controller is used for determining working condition exhaust information, generating a corresponding control instruction according to the working condition exhaust information, and sending the control instruction to a power unit of the butterfly valve. The butterfly plate is driven by the power unit to rotate in the tail pipe by a corresponding angle according to the control instruction, so that the tail gas flow speed of the tail pipe can be changed, the expansion ratio can be changed according to the working condition of the vehicle, the corresponding exhaust noise reduction of the vehicle under different working conditions can be realized, and the noise reduction effect is good.

The inventor proposes a technical scheme of the application based on the creative discovery.

The embodiments of the present invention will be described with reference to the accompanying drawings.

Fig. 1 is a schematic structural diagram of a vehicle exhaust noise reduction device according to a first embodiment of the present invention, and as shown in fig. 1, the vehicle exhaust noise reduction device according to the present embodiment includes: a butterfly valve 20 and a controller 10.

The butterfly valve 20 includes a butterfly plate 22 and a power unit 21. The power unit 21 is communicatively coupled to the controller 10. The butterfly plate 22 is arranged in a tail pipe of the rear silencer, and the horizontal plane corresponding to the butterfly plate 22 is vertical to the tail gas flow direction of the tail pipe.

Meanwhile, the controller 10 is configured to determine the condition exhaust information and generate a corresponding control command according to the condition exhaust information, and send the control command to the power unit 21. The power unit 21 is used for driving the butterfly plate 22 to rotate in the tail pipe by a corresponding angle according to a control command.

In this embodiment, the controller 10 may be an electronic device such as a microprocessor, a vehicle-mounted control system, a single chip, and the like, and the shape of the butterfly plate 22 may be a circle, a square, or another shape, which is not limited in this embodiment.

In the present embodiment, the butterfly valve 20 is a normally open valve, and the rotation angle may be 0 to 90 degrees, or may be set according to actual requirements, which is not limited in the present embodiment. The horizontal plane corresponding to the butterfly plate 22 is perpendicular to the tail gas flow direction of the tail pipe, so that the butterfly plate 22 can better change the tail gas flow speed of the tail pipe when rotating at an angle.

In this embodiment, the operating condition exhaust information may be one of idle operating condition information, low speed operating condition information, medium speed operating condition information, high speed operating condition information, and rapid acceleration operating condition information, and may also set more operating condition information according to an actual operating condition of the vehicle.

In this embodiment, when the butterfly plate 22 corresponds the angle in the rotation, the change that corresponds can take place for the tail gas area that the butterfly plate 22 blockked, and when the tail gas area that the butterfly plate 22 blockked diminishes, the velocity of flow can diminish, and the expansion ratio diminishes, and on the same hand, when the tail gas area that the butterfly plate 22 blockked grow, the velocity of flow can grow, and the expansion ratio grow. So that the butterfly plate 22 can be controlled to rotate by corresponding angles according to different working conditions of the vehicle.

The embodiment of the invention provides a vehicle exhaust noise reduction device, which comprises: a butterfly valve 20 and a controller 10. The butterfly valve 20 includes a butterfly plate 22 and a power unit 21. The power unit 21 is communicatively coupled to the controller 10. The butterfly plate 22 is arranged in a tail pipe of the rear silencer, and the horizontal plane corresponding to the butterfly plate 22 is vertical to the tail gas flow direction of the tail pipe. The controller 10 is configured to determine the operating condition exhaust information, generate a corresponding control command according to the operating condition exhaust information, and send the control command to the power unit 21. The power unit 21 is used for driving the butterfly plate 22 to rotate in the tail pipe by a corresponding angle according to a control command. The device of the embodiment of the invention determines the working condition exhaust information through the controller 10, and then generates the corresponding control instruction according to the working condition exhaust information, and the generated corresponding control instruction also changes correspondingly because the working condition exhaust information changes along with the change of the working condition of the vehicle. The power unit 21 in the device can drive the butterfly plate 22 to rotate in the tail pipe by a corresponding angle according to a control instruction, so that the flow speed of tail gas in the tail pipe can be changed according to the working condition of the vehicle, and the noise reduction of the vehicle exhaust under different working conditions is realized.

Fig. 2 is a schematic structural diagram of a butterfly valve 20 in a vehicle exhaust noise reduction device according to a second embodiment of the present invention, and as shown in fig. 2, the structure of the butterfly valve 20 and the function of the controller 10 are further detailed on the basis of the vehicle exhaust noise reduction device according to the previous embodiment, so that the vehicle exhaust noise reduction device according to the present embodiment further includes the following technical solutions.

Optionally, in this embodiment, the controller 10 is specifically configured to:

and acquiring engine operation parameter data of the target vehicle, and determining working condition exhaust information according to the engine operation parameter data.

In this embodiment, the engine operating parameter data may include parameter data such as engine speed, intake air flow rate, internal torque, and the like, which is not limited in this embodiment. The working condition exhaust information can be determined according to the engine operation parameter data, for example, when the engine speed is in the threshold range of the low-speed working condition, the vehicle can be judged to operate in the corresponding low-speed working condition, and the working condition exhaust information is the low-speed working condition information. Similarly, the exhaust information of other working conditions can be determined in the same way, and the description is not repeated.

In this embodiment, the engine operating parameter data of the target vehicle may be obtained by inputting the engine operating parameter data of the target vehicle by a user, or the engine operating parameter data of the target vehicle may be obtained in a vehicle management system.

Optionally, in this embodiment, the control command is an increase flow rate control command or a decrease flow rate control command. The working condition exhaust information is any one of medium-speed working condition information, high-speed working condition information, rapid acceleration working condition information, idling working condition information or low-speed working condition information.

When the controller 10 generates the control command according to the operating condition exhaust information, it is specifically configured to:

and if the working condition exhaust information is intermediate-speed working condition information, high-speed working condition information or rapid acceleration working condition information, generating a flow speed reduction control instruction according to the working condition exhaust information.

And if the working condition exhaust information is idle working condition information or low-speed working condition information, generating a flow rate increasing control instruction according to the working condition exhaust information.

In this embodiment, if the engine operates under the idle speed or low speed condition, that is, the exhaust information of the operating condition is the idle speed or low speed condition information, at this time, the displacement of the engine is small, and the air noise in the exhaust noise is the main component, an increase flow rate control command is generated according to the exhaust information of the operating condition, so as to change the rotation angle of the butterfly plate 22 through the butterfly valve 20, increase the flow rate of the tail pipe, and simultaneously, the area of the tail gas blocked by the butterfly plate 22 is increased, and the expansion ratio is also increased, thereby reducing the exhaust noise.

In this embodiment, if the engine operates in the medium-speed, high-speed, and rapid acceleration conditions, that is, the exhaust information of the operating condition is the medium-speed operating condition information, the high-speed operating condition information, or the rapid acceleration operating condition information, at this time, the exhaust flow of the engine is large, and the friction noise plays a dominant role, a flow rate reduction control command is generated according to the exhaust information of the operating condition, so as to change the rotation angle of the butterfly plate 22 through the butterfly valve 20, reduce the flow rate of the exhaust tail pipe, and simultaneously reduce the area of the tail gas blocked by the butterfly plate 22, thereby reducing the expansion ratio, and reducing the friction.

In the embodiment, under the condition of rapid acceleration, the influence result of the tail gas flow velocity change in the tail pipe on the passing noise is compared, after the flow velocity is reduced, the low-frequency broadband noise is obviously reduced in 350 Hz-2000 Hz, and finally the passing noise is reduced by 3.6 dBA.

Optionally, in this embodiment, the butterfly valve 20 further includes: a retaining ring 24 and a butterfly rod 23. The power unit 21 is located above the fixing ring 24.

The tail pipe passes through the retainer ring 24 and the butterfly rod 23 passes through the tail pipe and extends to the butterfly plate 22.

The power unit 21 is specifically configured to drive the butterfly rod 23 to rotate in the tail pipe by a corresponding angle according to a control command, so that the butterfly plate 22 rotates by a corresponding angle.

In this embodiment, the tail pipe passes through the fixing ring 24, and the power unit 21 is located above the fixing ring 24, so that the power unit 21 can be fixed on the tail pipe by the fixing ring 24, or can be located in other areas, which is not limited in this embodiment.

In this embodiment, the butterfly rod 23 includes a hatched area in fig. 2, which shows that the butterfly rod 23 passes through the retainer ring 24 and the tail pipe, and is connected to the butterfly plate 22. Thereby, the butterfly plate 22 can be controlled to rotate correspondingly according to the rotation angle of the butterfly rod 23.

In this embodiment, the power unit 21 can control the rotation of the butterfly plate 22 by the corresponding angle more simply and stably through the butterfly rod 23.

The vehicle exhaust noise reduction device of the embodiment determines the working condition exhaust information through the controller 10, and generates a corresponding control command according to the working condition exhaust information. The working condition exhaust information is any one of medium-speed working condition information, high-speed working condition information, rapid acceleration working condition information, idling working condition information or low-speed working condition information, and the control instruction is a flow rate increasing control instruction or a flow rate reducing control instruction. Because the working condition exhaust information changes along with the change of the working condition of the vehicle, the generated corresponding control command also changes correspondingly. If the engine operates under the idle speed or low speed working condition, namely the working condition exhaust information is the idle speed working condition information or the low speed working condition information, at the moment, the exhaust volume of the engine is small, and the air noise in the exhaust noise is the main component, a flow rate increasing control instruction is generated according to the working condition exhaust information, so that the rotation angle of the butterfly plate 22 is changed through the butterfly valve 20, the flow rate of the exhaust tail pipe is increased, meanwhile, the expansion ratio is increased, and the exhaust noise is reduced. If the engine operates in the medium-speed, high-speed and rapid-acceleration working conditions, that is, the working condition exhaust information is the medium-speed working condition information, the high-speed working condition information or the rapid-acceleration working condition information, at this time, the exhaust flow of the engine is large, and the friction noise plays a leading role, a flow-rate reduction control instruction is generated according to the working condition exhaust information, so that the rotation angle of the butterfly plate 22 is changed through the butterfly valve 20, the flow rate of the exhaust tail pipe is reduced, the expansion ratio is also reduced, the friction noise can be reduced, and the exhaust noise. Therefore, the vehicle exhaust noise reduction device of the embodiment can change the flow velocity of tail gas in the tail pipe according to the working condition of the vehicle, and further realize the noise reduction of the vehicle exhaust under different working conditions.

Referring to fig. 3, fig. 3 is a schematic flow chart of a vehicle exhaust noise reduction method according to a third embodiment of the present invention. The vehicle exhaust noise reduction method of the embodiment includes:

and S101, determining working condition exhaust information by the controller, generating a control command according to the working condition exhaust information, and sending the control command to the power unit.

And step S102, the power unit drives the butterfly plate to rotate in the tail pipe by a corresponding angle according to the control command.

In the method for reducing noise in vehicle exhaust provided in this embodiment, based on the structure and function of the device for reducing noise in vehicle exhaust, the structure and function of the device for reducing noise in vehicle exhaust are similar to those of the device for reducing noise in vehicle exhaust provided in the first embodiment of the present invention, and are not described again.

The embodiment of the invention provides a vehicle exhaust noise reduction method, which comprises the following steps: the controller determines working condition exhaust information, generates a control command according to the working condition exhaust information, and sends the control command to the power unit. And the power unit drives the butterfly plate to rotate in the tail pipe by a corresponding angle according to the control instruction. The method of the embodiment of the invention determines the working condition exhaust information through the controller, and then generates the corresponding control instruction according to the working condition exhaust information, and the generated corresponding control instruction can correspondingly change because the working condition exhaust information changes along with the change of the working condition of the vehicle. The power unit can drive the butterfly plate to rotate in the tail pipe by corresponding angles according to the control instruction, so that the flow velocity of tail gas in the tail pipe can be changed according to the working conditions of the vehicle, and the noise reduction of the vehicle exhaust under different working conditions is realized.

The present embodiment further provides a vehicle exhaust noise reduction method, on the basis of the vehicle exhaust noise reduction method provided in the previous embodiment, step 101 is further detailed, and then the vehicle exhaust noise reduction method of the present embodiment further includes the following steps:

optionally, in this embodiment, step S101 includes:

in step S1011, the controller obtains engine operating parameter data of the target vehicle, and determines the operating condition exhaust information according to the engine operating parameter data.

In this embodiment, the control command is an increase flow rate control command or a decrease flow rate control command. The working condition exhaust information is any one of medium-speed working condition information, high-speed working condition information, rapid acceleration working condition information, idling working condition information or low-speed working condition information.

Step S1012, if the operating condition exhaust information is medium-speed operating condition information, high-speed operating condition information, or rapid acceleration operating condition information, the controller generates a flow rate reduction control command according to the operating condition exhaust information.

And if the working condition exhaust information is idle working condition information or low-speed working condition information, the controller generates a flow rate increasing control instruction according to the working condition exhaust information.

In the method for reducing noise in exhaust gas of a vehicle according to this embodiment, based on the structure and function of the device for reducing noise in exhaust gas of a vehicle, the structure and function of the device for reducing noise in exhaust gas of a vehicle are similar to those of the device for reducing noise in exhaust gas of a vehicle according to the first embodiment or the second embodiment of the present invention, and are not described herein again.

Fig. 4 is a schematic structural diagram of a rear muffler device according to a fourth embodiment of the present invention, and as shown in fig. 4, the present embodiment further provides a rear muffler device, and the rear muffler device of the present embodiment includes:

the vehicle exhaust noise reduction device 210 of the first embodiment or the second embodiment, and the tail pipe 220.

The vehicle exhaust noise reduction device 210 is fixedly connected to a tail pipe 220.

In the rear muffler device provided in this embodiment, the structure and function of the vehicle exhaust noise reduction device are similar to those of the vehicle exhaust noise reduction devices provided in the first and second embodiments of the present invention, and are not described again.

Fig. 5 is a schematic structural view of a rear muffler device according to a fifth embodiment of the present invention. As shown in fig. 5, the rear muffler device provided in this embodiment is further refined on the basis of the rear muffler device provided in the previous embodiment, and the rear muffler device provided in this embodiment further includes the following technical solutions.

Wherein the butterfly valve 20 is disposed above the tail pipe 220.

Optionally, in this embodiment, the method further includes: perforated tube 260.

The outlet end of perforated pipe 260 is connected to the inlet end of tail pipe 220.

Wherein the perforated pipe 260 is covered with a plurality of perforations on the surface thereof, and no perforations are present on the surface thereof near a predetermined length area of the tail pipe 220.

In this embodiment, the perforated pipe 260 mainly plays a role of throttling and silencing, when the airflow flows in the hole, part of sound energy is consumed and converted into heat energy due to damping and friction on the wall of the hole, and the middle-low frequency noise is mainly reduced.

In this embodiment, the preset length region may be a length region of approximately four rows of perforations, and when there is no perforation at the rear four rows of perforations, the preset length region does not sweep-blow out the mixed flow, and does not form a sound source. Meanwhile, after the rear perforation is removed in the preset length area, the passing flow speed of other perforation positions of the outlet is increased, the jet flow strength is increased, the glancing flow is damaged, namely the influence of the glancing-passing mixed flow at other perforation positions is weakened, the formation of a sound source is further weakened, the broadband flow noise is reduced, and therefore the exhaust noise is reduced.

Optionally, in this embodiment, the method further includes: a housing 230, a baffle 240, a tail plate 250, and an inlet pipe 270.

The front end of the housing 230 is provided with a partition 240, and the rear end is provided with a tail plate 250, and the intake pipe 270 passes through the partition 240 and extends into the housing 230.

Wherein a perforated tube 260 is provided between the separator 240 and the tailgate 250. The tail pipe 220 is provided outside the housing 230. The outlet end of perforated pipe 260 extends through tail plate 250 and connects to the inlet end of tail pipe 220.

In this embodiment, the air inlet pipe 270 is mainly used to discharge the tail gas output from the intermediate carrier portion into the expansion cavity formed by the casing 230, the partition 240 and the tail plate 250, and the tail gas is discharged to the outside after entering the expansion cavity and being denoised by the perforated pipe 260 and the tail pipe 220.

Optionally, in this embodiment, the tail plate 250 is a perforated plate.

Meanwhile, the rear muffler device further includes a sound absorbing material 280. The sound absorbing material 280 is filled between the tailgate and the case.

In this embodiment, since the tail plate 250 is a perforated plate, the tail gas can enter the sound absorbing material 280 through the tail plate 250 after entering the expansion cavity, and the sound energy is absorbed by the sound absorbing material and converted into heat energy, so that further noise reduction can be performed through the sound absorbing material 280.

In order to further facilitate understanding of the improvement of the perforated pipe in the technical solution of the present embodiment, a corresponding description will be made below with reference to fig. 6. Fig. 6 is a schematic diagram of an optimized structure of a perforated pipe of a rear muffler device according to a fifth embodiment of the present invention.

The conventional perforated pipe is as shown in fig. 6 on the left, and the entire perforated pipe is covered with perforations. It has been found that the main sound source of the rapid acceleration process of the vehicle is present at the four rows of perforations behind the perforated pipe, because the flow at the four rows of perforations behind the perforated pipe is a mixed sweep-blow flow (flowing from the back cavity into the duct), which is the most noise-prone flow form, and the broadband noise is formed by the resonant coupling with the back cavity. This embodiment, by eliminating four rows of perforations, as shown in fig. 6 on the right, can have the following effects: first, the mixed flow of sweeping and blowing is not generated at the positions of the rear four rows of perforations, and a sound source is not formed. And secondly, after the four rows of rear perforations are removed, the passing flow speed of other perforations at the outlet is increased, the jet flow strength is increased, the glancing flow is damaged, namely the influence of the glancing-passing mixed flow at other perforations is weakened, the formation of a sound source is further weakened, the broadband flow noise is reduced, and therefore the exhaust noise is reduced.

Fig. 7 is a schematic structural diagram of an integrated catalytic conversion muffler according to a sixth embodiment of the present invention. As shown in fig. 7, an embodiment of the present invention further provides an integrated catalytic conversion muffler, and then an integrated catalytic conversion muffler of the embodiment includes:

a pre-muffler treatment device 310, an intermediate carrier part 320, and a post-muffler device 330 according to the fourth or fifth embodiment.

The pre-muffler treatment device 310 is connected to the post-muffler device 330 via the intermediate carrier portion 320.

In the integrated catalytic conversion muffler provided by this embodiment, the structure and function of the rear muffler device are similar to those of the rear muffler devices provided by the fourth and fifth embodiments of the present invention, and are not described again.

Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the embodiments of the invention following, in general, the principles of the embodiments of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the embodiments of the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of embodiments of the invention being indicated by the following claims.

It is to be understood that the embodiments of the present invention are not limited to the precise arrangements described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of embodiments of the invention is limited only by the appended claims.