Urban road traffic noise reduction device and method

Abstract

The urban road traffic noise reduction device comprises a stand column arranged on the side of a road or a central isolation strip of the road, the lower end of the stand column is connected with the ground, a mounting shell is arranged on the side, facing the road, of the upper end of the stand column, and a porous acoustic board is arranged in the mounting shell in a sliding fit mode; the porous acoustic panel can slide in the mounting shell in the direction close to or away from a road; the driving assembly is connected with the porous acoustic board and is used for driving the porous acoustic board to slide in the mounting shell. The porous sound-absorbing plate is arranged in the mounting shell as a movable element and can be driven by the driving assembly to slide back and forth in the mounting shell, so that the position state of the sound-absorbing material is dynamically adjusted, periodic disturbance of the surface of the sound-absorbing material and periodic change of the volume of an inner cavity of the mounting shell are achieved, and the sound-absorbing effect on noise of a specific frequency band is enhanced.

Description

Technical Field

[0001] This invention relates to the field of road noise reduction technology, specifically to urban road traffic noise reduction devices and methods. Background Technology

[0002] With the acceleration of urbanization, road traffic noise pollution is becoming increasingly serious. To address this, sound barriers are often used for noise reduction. However, traditional sound barriers have obvious limitations due to their fixed structure. Single noise reduction frequency band: The sound absorption coefficient of porous sound-absorbing materials (such as glass wool) is strongly correlated with density, and the fixed structure cannot dynamically optimize the acoustic impedance matching; the resonant frequency of the Helmholtz resonator is fixed by the cavity volume, making it difficult to adapt to the main frequency of traffic noise (such as the 80~2000Hz frequency shift caused by vehicle acceleration / deceleration). Energy waste: The airflow generated by vehicle movement is not effectively utilized, and active noise reduction devices require external power, increasing operation and maintenance costs.

[0003] Therefore, there is an urgent need to develop a self-powered, adaptive road noise reduction device that uses a mechanical structure to convert wind energy into dynamic adjustment of sound-absorbing components, thereby achieving real-time tracking and efficient absorption of noise frequency bands. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a noise reduction device and method for urban road traffic, so as to solve the problems that existing sound barriers are not convenient to adapt to the dominant noise frequency due to their fixed structure, and that the airflow of vehicles is not utilized to cooperate with the sound barrier for noise reduction.

[0005] This invention is achieved through the following technical solution: A noise reduction device for urban road traffic includes a column installed on the side of the road or in the central median strip. The lower end of the column is connected to the ground, and the upper end facing the road has a mounting shell. A porous sound-absorbing plate is slidably fitted inside the mounting shell. The porous sound-absorbing plate can slide in the mounting shell in a direction close to or away from the road. It also includes a drive assembly connected to the porous sound-absorbing panel, the drive assembly being used to drive the porous sound-absorbing panel to slide within the mounting housing.

[0006] Further defined, the drive assembly includes a first rotating shaft, a cam, a roller, an elastic support member, and a drive member. The first rotating shaft is coaxially arranged with the column and rotatably connected to the column. The first rotating shaft is connected to the drive member. The cam is connected to the first rotating shaft. The roller is rotatably connected to the side of the porous sound-absorbing panel away from the road. The roller is located on the rotation trajectory of the cam protrusion. The two ends of the elastic support are respectively connected to the side of the porous sound-absorbing panel away from the road and the inner wall of the mounting shell.

[0007] Further defining the drive assembly, the drive assembly includes a second rotating shaft, a crank, a connecting rod, and a drive member. The second rotating shaft is coaxially arranged with the column and rotatably connected to the column. One end of the second rotating shaft is connected to the drive member, and the other end is connected to one end of the crank. The end of the crank away from the second rotating shaft is hinged to the connecting rod, and the end of the connecting rod away from the crank is hinged to the side of the porous sound-absorbing panel away from the road.

[0008] Further specifying, the driving component is a blade, and the blade is rotatably connected to the top surface of the column.

[0009] Further, the mounting housing has limit grooves on both opposite sides, and limit blocks are slidably connected in the limit grooves. The two limit blocks are respectively connected to the two ends of the porous sound-absorbing plate.

[0010] Further defining, the porous sound-absorbing panel comprises, from the outside to the inside, a perforated aluminum plate, a glass wool layer, and a Helmholtz resonant cavity array, with the neck opening of the Helmholtz resonant cavity array facing the road.

[0011] A method for reducing noise from urban road traffic includes an urban road traffic noise reduction device and further includes the following steps: Step 1: Divide a section of the road into noise reduction sections, and install multiple urban road traffic noise reduction devices on the side or central median of the road in the noise reduction sections. The multiple urban road traffic noise reduction devices are distributed along the extension direction of the road. Step 2: The drive assembly converts the airflow energy generated by the vehicle's movement into mechanical kinetic energy, and drives the porous sound-absorbing panel to slide within the mounting housing; Step 3: The sliding of the porous sound-absorbing panel forces the glass wool layer to periodically compress and expand, increasing the frictional energy consumption between the sound waves and the fibers; the change in the volume of the Helmholtz resonant cavity tunes its resonant frequency, tracking the dominant frequency of traffic noise.

[0012] Further specifying, the urban road traffic noise reduction device is distributed on curved road sections, and the blades adopt an asymmetric airfoil with a pressure surface curvature greater than the suction surface curvature.

[0013] The beneficial effects of this invention are as follows: The porous sound-absorbing panel is a movable element located inside the mounting housing. It can be driven by a drive component to slide back and forth within the mounting housing, thereby dynamically adjusting the position and state of the sound-absorbing material. This achieves periodic disturbance of the surface of the sound-absorbing material and periodic change of the volume of the cavity inside the mounting housing, enhancing the sound absorption effect on noise in a specific frequency band.

[0014] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0015] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a schematic diagram of the internal structure of the mounting shell according to Embodiment 1 of the present invention; Figure 3 This is a partial structural diagram of the driving component according to Embodiment 1 of the present invention; Figure 4 This is a schematic diagram of the internal structure of the mounting shell according to Embodiment 2 of the present invention.

[0016] In the picture: 1. Column; 2. Mounting shell; 3. Perforated sound-absorbing panel; 4. First rotating shaft; 401. Cam; 402. Roller; 403. Elastic support; 5. Second rotating shaft; 501. Crank; 502. Connecting rod; 6. Blade; 7. Limiting groove; 8. Limiting block. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0018] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0019] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0020] In the above description of the present invention, it should be noted that the terms "one side," "the other side," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is conventionally placed during use. These terms are used only for the convenience of describing the present invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0021] Furthermore, terms such as "identical" do not imply that components must be absolutely identical; minor differences are permissible. The term "perpendicular" simply means that the positional relationship between components is more perpendicular than "parallel," not that the structure must be perfectly perpendicular; a slight tilt is acceptable.

[0022] Please see Figure 1-3 The present invention provides a technical solution: Example 1: Urban road traffic noise reduction device, including a column 1 set on the side of the road or in the central median strip of the road. The lower end of the column 1 is connected to the ground, and the upper end is provided with a mounting shell 2 facing the road. A porous sound-absorbing plate 3 is slidably fitted inside the mounting shell 2. The porous sound-absorbing plate 3 can slide in the mounting shell 2 in a direction close to or away from the road. It also includes a drive assembly connected to the porous sound-absorbing panel 3, the drive assembly being used to drive the porous sound-absorbing panel 3 to slide within the mounting housing 2.

[0023] In this solution, the porous sound-absorbing plate 3 is installed inside the mounting shell 2 as a movable element. It can be driven by the drive component to slide back and forth inside the mounting shell 2, thereby dynamically adjusting the position and state of the sound-absorbing material, realizing periodic disturbance of the surface of the sound-absorbing material and periodic change of the volume of the cavity inside the mounting shell 2, and enhancing the sound absorption effect on noise in a specific frequency band.

[0024] In this embodiment, the driving assembly includes a first rotating shaft 4, a cam 401, a roller 402, an elastic support 403, and a driving component. The first rotating shaft 4 is coaxially arranged with the column 1 and rotatably connected to the column 1. The first rotating shaft 4 is connected to the driving component. The cam 401 is connected to the first rotating shaft 4. The roller 402 is rotatably connected to the side of the porous sound-absorbing plate 3 away from the road. The roller 402 is located on the rotation trajectory of the protrusion of the cam 401. The driving component is a blade 6, which is rotatably connected to the top surface of the column 1.

[0025] The two ends of the elastic support 403 are respectively connected to the side of the porous sound-absorbing plate 3 away from the road and the inner wall of the mounting shell 2.

[0026] Among them, the roller 402 is connected to the porous sound-absorbing plate 3. The roller 402 and the porous sound-absorbing plate 3 move synchronously. When the elastic support 403 extends naturally, it pushes the porous sound-absorbing plate 3 away from the road. In this state, the roller 402 is located on the rotation trajectory of the protrusion of the cam 401. The profile of the cam 401 is a closed curve. In this scheme, the driving component serves as the power source, and the first rotating shaft 4 serves as the transmission component connected to the driving component. The driving component drives the first rotating shaft 4 to rotate, which in turn drives the cam 401 connected to the first rotating shaft 4 to rotate synchronously, and causes the protruding part of the cam 401 to rotate around the axis of the first rotating shaft 4.

[0027] During rotation, since the roller 402 is located on the rotation trajectory of the protrusion of the cam 401, when the protrusion of the cam 401 rotates to a specific position (e.g., an angle of 30-40°), the protrusion of the cam 401 contacts the roller 402 and exerts pressure on the roller 402, causing the roller 402 and the porous sound-absorbing plate 3 to overcome the elastic force of the elastic support member 403 and be pushed by the protrusion of the cam 401 in a direction closer to the road. At the same time, the elastic support member 403 stores elastic energy. As the protrusion of the cam 401 continues to rotate (after rotating to 41°), the protrusion of the cam 401 rotates to deviate from the roller 402, and the roller 402 no longer contacts the protrusion of the cam 401, and is no longer subjected to the pressure of the protrusion. Under the elastic force of the elastic support member 403, the roller 402 and the porous sound-absorbing plate 3 are pulled back to their original positions, thereby realizing the reciprocating sliding of the porous sound-absorbing plate 3.

[0028] The driving component uses a blade 6, which is installed on the side of the road to capture turbulence generated by vehicles. The turbulence generated by the vehicle generates wind energy to drive the blade 6 to rotate, and the blade 6 drives the first rotating shaft 4 to rotate synchronously. In this way, no additional energy consumption is required. The vehicle speed is proportional to the noise intensity, and the vehicle speed is also proportional to the rotation speed of the blade 6. Therefore, the faster the vehicle travels, the greater the wind energy generated, and the faster the blade 6 rotates. The frequency of the reciprocating sliding of the porous sound-absorbing panel 3 is also higher. The periodic disturbance of the surface of the sound-absorbing material and the periodic adaptive change of the internal volume of the mounting shell 2 increase the friction with the sound waves, which can better convert them into heat energy for consumption, thereby achieving the noise reduction effect.

[0029] When the speed of blade 6 is ≥50rpm, the sliding frequency of the sound-absorbing plate is tuned to the main noise frequency above 500Hz.

[0030] The blade 6 and the first shaft 4 can be stabilized by installing components such as damping rings.

[0031] In this embodiment, limiting grooves 7 are provided on both opposite sides of the mounting shell 2, and limiting blocks 8 are slidably connected in the limiting grooves 7. The two limiting blocks 8 are respectively connected to the two ends of the porous sound-absorbing plate 3.

[0032] In this solution, the movement trajectory of the porous sound-absorbing plate 3 is constrained by the sliding cooperation of the limiting groove 7 and the limiting block 8. By limiting the linear movement of the porous sound-absorbing plate 3, the wear caused by the offset during the sliding of the porous sound-absorbing plate 3 is reduced.

[0033] In this embodiment, the porous sound-absorbing plate 3 includes, from the outside to the inside, a perforated aluminum plate, a glass wool layer, and a Helmholtz resonant cavity array, with the neck opening of the Helmholtz resonant cavity array facing the road.

[0034] In this scheme, the glass wool layer is periodically compressed / expanded to form changes in fiber density, thereby optimizing the frictional dissipation of mid-to-high frequency sound energy. Specifically, when the porous sound-absorbing panel 3 slides towards the road, the glass wool layer is compressed, the fiber gaps decrease, the density increases, the tortuosity of the sound wave propagation path in the dense fiber network increases, and the frictional heat loss increases.

[0035] The cavity sidewall of the Helmholtz resonant cavity array is made of a flexible diaphragm. The change in the cavity volume of the mounting shell 2 compresses the diaphragm to deform, thereby realizing continuous adjustment of the cavity volume and thus achieving tuning of the resonant frequency, dynamically tracking the noise master frequency of 80~2000Hz.

[0036] A method for reducing noise from urban road traffic includes an urban road traffic noise reduction device and further includes the following steps: Step 1: Divide a section of the road into noise reduction sections, and install multiple urban road traffic noise reduction devices on the side or central median of the road in the noise reduction sections. The multiple urban road traffic noise reduction devices are distributed along the extension direction of the road. Step 2: The drive assembly converts the airflow energy generated by the vehicle's movement into mechanical kinetic energy, and drives the porous sound-absorbing panel 3 to slide within the mounting housing 2; Step 3: The sliding of the porous sound-absorbing panel 3 forces the glass wool layer to periodically compress and expand, increasing the frictional energy consumption between the sound waves and the fibers; the change in the volume of the Helmholtz resonant cavity tunes its resonant frequency, tracking the main frequency of traffic noise.

[0037] In this embodiment, the urban road traffic noise reduction device is distributed on curved road sections. The blades of the 6 blades adopt an asymmetric airfoil with a greater curvature of the pressure surface than that of the suction surface, thereby enhancing the starting torque under crosswind conditions.

[0038] In this design, the large curvature of the pressure surface enables the blade 6 to generate high torque when facing crosswinds, reducing the difficulty of starting due to the changing wind direction when located on road curves, thus ensuring continuous operation under low wind speed / changing wind direction conditions and expanding the applicable area.

[0039] Please see Figure 4 Example 2: The difference from Example 1 is that the drive assembly includes a second rotating shaft 5, a crank 501, a connecting rod 502, and a drive component. The second rotating shaft 5 is coaxially arranged with the column 1 and is rotatably connected to the column 1. One end of the second rotating shaft 5 is connected to the drive component, and the other end is connected to one end of the crank 501. The end of the crank 501 away from the second rotating shaft 5 is hinged to the connecting rod 502. The end of the connecting rod 502 away from the crank 501 is hinged to the side of the porous sound-absorbing plate 3 away from the road.

[0040] In this scheme, wind energy drives the blade 6 to rotate, and the blade 6 drives the second shaft 5 and crank 501 to rotate. Finally, through the cooperation of crank 501 and connecting rod 502, the porous sound-absorbing panel 3 is pushed and pulled, causing the porous sound-absorbing panel 3 to slide back and forth in a straight line in the direction away from or towards the road.

[0041] When the hinge of crank 501 and connecting rod 502 rotates to the side closer to the porous sound-absorbing plate 3, it generates a thrust on the porous sound-absorbing plate 3; conversely, when the hinge of crank 501 and connecting rod 502 rotates to the side farther away from the porous sound-absorbing plate 3, it generates a pull on the porous sound-absorbing plate 3.

[0042] Compared to Embodiment 1, Embodiment 2 uses a crank-connecting rod mechanism, which can provide greater output force at low speeds of blade 6, making it more suitable for dealing with low-frequency noise main frequencies.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A noise reduction device for urban road traffic, characterized in that: It includes a column (1) set on the side of the road or in the median strip of the road. The lower end of the column (1) is connected to the ground, and the upper end is provided with a mounting shell (2) facing the road. A perforated sound-absorbing plate (3) is slidably fitted inside the mounting shell (2). The perforated sound-absorbing plate (3) can slide in the mounting shell (2) in a direction close to or away from the road. It also includes a drive assembly connected to the porous sound-absorbing panel (3), the drive assembly being used to drive the porous sound-absorbing panel (3) to slide within the mounting housing (2).

2. The urban road traffic noise reduction device according to claim 1, characterized in that: The drive assembly includes a first rotating shaft (4), a cam (401), a roller (402), an elastic support (403), and a drive component. The first rotating shaft (4) is coaxially arranged with the column (1) and rotatably connected to the column (1). The first rotating shaft (4) is connected to the drive component. The cam (401) is connected to the first rotating shaft (4). The roller (402) is rotatably connected to the side of the porous sound-absorbing plate (3) away from the road. The roller (402) is located on the rotation trajectory of the protrusion of the cam (401). The two ends of the elastic support (403) are respectively connected to the side of the porous sound-absorbing plate (3) away from the road and the inner wall of the mounting shell (2).

3. The urban road traffic noise reduction device according to claim 1, characterized in that: The drive assembly includes a second rotating shaft (5), a crank (501), a connecting rod (502), and a drive component. The second rotating shaft (5) is coaxially arranged with the column (1) and is rotatably connected to the column (1). One end of the second rotating shaft (5) is connected to the drive component, and the other end is connected to one end of the crank (501). The end of the crank (501) away from the second rotating shaft (5) is hinged to the connecting rod (502), and the end of the connecting rod (502) away from the crank (501) is hinged to the side of the porous sound-absorbing plate (3) away from the road.

4. The urban road traffic noise reduction device according to claim 2 or 3, characterized in that: The driving component is a blade (6), which is rotatably connected to the top surface of the column (1).

5. The urban road traffic noise reduction device according to claim 1, characterized in that: The mounting shell (2) has limiting grooves (7) on both opposite sides. Limiting blocks (8) are slidably connected in the limiting grooves (7). The two limiting blocks (8) are respectively connected to the two ends of the porous sound-absorbing plate (3).

6. The urban road traffic noise reduction device according to claim 1, characterized in that: The porous sound-absorbing panel (3) comprises, from the outside to the inside, a perforated aluminum plate, a glass wool layer, and a Helmholtz resonant cavity array, with the neck opening of the Helmholtz resonant cavity array facing the road.

7. A method for reducing noise in urban road traffic, comprising the urban road traffic noise reduction device as described in any one of claims 1-6, characterized in that: It also includes the following steps: Step 1: Divide a section of the road into noise reduction sections, and install multiple urban road traffic noise reduction devices on the side or central median of the road in the noise reduction sections. The multiple urban road traffic noise reduction devices are distributed along the extension direction of the road. Step 2: The airflow generated by the vehicle's movement is converted into mechanical kinetic energy using the drive assembly, and the porous sound-absorbing panel (3) is driven to slide within the mounting housing (2); Step 3: The sliding of the porous sound-absorbing plate (3) forces the glass wool layer to compress and expand periodically, increasing the frictional energy consumption between the sound wave and the fiber; the volume change of the Helmholtz resonant cavity tunes its resonant frequency, tracking the main frequency of traffic noise.

8. The urban road traffic noise reduction method according to claim 7, characterized in that: In step one, when the urban road traffic noise reduction device is distributed on a curved road section, the blade (6) adopts an asymmetric airfoil, and the curvature of the pressure surface is greater than that of the suction surface.

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