Helmholtz resonance type sound absorption wall with adjustable aperture size

Abstract

The utility model discloses a Helmholtz resonance type sound absorption wall with adjustable aperture size, which comprises frequency-adjustable Helmholtz resonators and a power transmission mechanism, and the frequency-adjustable Helmholtz resonators are linearly arranged horizontally and vertically and are fixedly connected to form the sound absorption wall; the frequency-adjustable Helmholtz resonator is composed of a base plate, a sliding block, a top cover and a Helmholtz resonant cavity, the sliding block is driven by rotating the top cover through a straight notch in the back face of the top cover to do linear motion in a regular hexagon groove in the base plate so as to change the size of the aperture, and therefore the sound absorption frequency of the structure is changed. The power transmission mechanism can synchronously control a plurality of Helmholtz resonators which are horizontally and vertically connected in parallel, the horizontal row is subjected to frequency modulation through belt transmission, and the vertical row is subjected to gear transmission to realize synchronous rotation; the sound absorption wall is based on the Helmholtz resonance sound absorption principle, can absorb most of daily indoor low and medium frequency noise, is compact in structure, facilitates frequency modulation, is convenient to process and manufacture, can resist deformation, and has a wide application prospect in the field of architectural acoustics.

Description

Technical Field

[0001] The utility model relates to the field of architectural acoustics and noise control, in particular to the common medium and low frequency noises in life. The utility model can adjust its own structure to achieve absorption of corresponding noise frequencies. Specifically, it is a Helmholtz resonance sound-absorbing wall with adjustable aperture size. Background Art

[0002] Noise pollution, like air pollution and water pollution, has become a major environmental issue in human life. Noise not only harms human health but also affects the efficiency of factory operations.

[0003] The best way to reduce noise is to reduce it within the transmission path and control its propagation, such as through sound absorption and sound insulation. Porous and resonant sound-absorbing materials are commonly used for sound absorption. Porous sound-absorbing materials effectively suppress mid- and high-frequency noise, but are less effective at absorbing penetrating low-frequency noise. Resonant sound-absorbing materials, such as Helmholtz resonators and FP resonant tubes, are commonly used to suppress low-frequency noise. A Helmholtz resonator unit consists of a neck tube and an enclosed cavity. Its sound absorption frequency depends on the volume of the enclosed cavity, the length of the neck tube, and the cross-sectional area of ​​the neck tube. To achieve low-frequency sound absorption, measures such as increasing the volume of the enclosed cavity, lengthening the neck tube, and reducing the cross-sectional area of ​​the neck tube can be taken. Generally speaking, due to space constraints, it is difficult to freely change the volume of the resonant cavity in practical applications. However, changing the neck characteristics of the resonator is more practical and can simultaneously change the resonant frequency and the resonant sound absorption coefficient. In practical applications, once the sound-absorbing material or structural design is installed, its noise reduction frequency range is fixed. To change the sound absorption frequency, the structural design and assembly must be redesigned and reassembled. However, environmental noise is complex and variable, and this fixed structure is clearly unable to adapt. Its noise reduction effect on noise outside the designed frequency range is very weak. Therefore, designing a low-frequency, space-saving, frequency-adjustable sound-absorbing structure that is easy to install is an urgent problem to be solved in the field of noise reduction. Summary of the Invention

[0004] In view of the shortcomings of the above-mentioned existing technologies, the technical problem to be solved by the present invention is to provide a Helmholtz resonance sound-absorbing wall with adjustable aperture size. The sound-absorbing wall can adjust the aperture size of the Helmholtz resonator according to the frequency of the ambient noise to change the sound absorption frequency, thereby realizing the automatic frequency modulation sound absorption function of the structure.

[0005] In order to achieve the above technical objectives, the technical solution adopted by the utility model is:

[0006] A Helmholtz resonance sound-absorbing wall with adjustable aperture size, comprising: a frequency-adjustable Helmholtz resonator and a power transmission mechanism;

[0007] The frequency-adjustable Helmholtz resonator comprises: a chassis, a slider, a top cover and a Helmholtz resonance cavity; the chassis is a cylinder with a circular through hole at the center, a regular hexagonal groove outside the circular through hole, and the geometric centers of the two are at the same position; the slider is a pentagonal thin plate, the upper half of which is an isosceles triangle and the lower half is a rectangle, wherein a cylindrical protrusion is provided at the lower rectangular position of the front end surface of the slider, and a rectangular protrusion is provided at the lower rectangular position of the rear end surface, and the rectangular protrusion is located at the bottom corner; a circular hole is provided at the center position of the top cover, and six protrusions are provided at the rear end. The front end of the top cover is a hollow pulley, and the rear end is a cylindrical thin wall. The Helmholtz resonance cavity is a hollow rectangular parallelepiped with a circular aperture at the front end. The outer circumference of the chassis is fixedly connected to the circumference of the circular aperture, and the rear end of the chassis coincides with the inner wall of the Helmholtz resonance cavity. The rectangular parallelepiped protrusion is placed in the regular hexagonal groove, and the outer surface and the inner wall of the regular hexagonal groove fit together seamlessly. The cylindrical protrusion is placed inside the straight slot. The top cover is inserted into the circular aperture, with the circular hole facing the circular through hole, and the hollow pulley is exposed outside the circular aperture.

[0008] The power transmission mechanism includes: a driving pulley, a transmission belt, a large gear, a small gear, a small gear limiter, a rotating shaft, a motor, and a motor table; the driving pulley is a cylinder with a pulley shaft hole in the center; the transmission belt is tightly sleeved on the hollow pulley and the driving pulley; a gear shaft hole is provided at the center of the large gear; a limit hole is provided at the center of the small gear; the large gear and the small gear are meshed with each other, and the small gear is arranged directly above the large gear; the small gear limiter is "U"-shaped, with both ends fixedly connected to the wall surface of the Helmholtz resonance cavity, and the middle part passes through the limit hole; one end of the rotating shaft is fixedly inserted in the pulley shaft hole, and the other end is fixedly inserted in the gear shaft hole; the motor is fixedly connected to the surface of the motor table, and the motor output shaft is fixedly welded to the rotating shaft;

[0009] The motor controls the forward and reverse rotation of the motor output shaft and the rotating shaft, thereby driving the front driving pulley and the large gear at the back to rotate simultaneously; the horizontal transmission belt drives the entire row of hollow pulleys to rotate together, and the top cover rotates accordingly. The straight slot at its rear end drives the sliders to make linear motion within the regular hexagonal grooves on the chassis, thereby changing the size of the area enclosed by the six sliders; the vertical large and small gears engage with each other, and the large gear drives the rotating shaft, which in turn drives the front driving pulley to rotate. The integrated control of the entire wall of Helmholtz resonators is completed by a single motor.

[0010] Helmholtz resonators of the same size are glued horizontally to form a row, and several rows of Helmholtz resonators are glued vertically to form a complete Helmholtz resonance sound-absorbing wall with adjustable aperture size.

[0011] As a further improved technical solution of the present invention, the pitch circle diameters of the driving pulley, hollow pulley and large gear are equal, and the tooth surface widths are equal; the large gear and the small gear are both spur gears with external meshing; the diameters of the pulley shaft hole, the gear shaft hole and the rotating shaft are equal; the height of the cylindrical protrusion is equal to the depth of the straight slot, and the two are the same width; the areas of the circular through hole and the circular hole are the same.

[0012] As a further improved technical solution of the present invention, the frequency-adjustable Helmholtz resonator is made of rigid materials, including concrete, steel and aluminum alloy.

[0013] The beneficial effects of the utility model are:

[0014] The utility model proposes a Helmholtz resonance sound-absorbing wall with adjustable aperture size, which is composed of a frequency-adjustable Helmholtz resonator and a power transmission mechanism. The single frequency-adjustable Helmholtz resonator is linearly arranged in the horizontal and vertical directions and fixedly connected to form a complete sound-absorbing wall. The purpose of linearly arranging several Helmholtz resonators is to increase the sound absorption area. The horizontal belt transmission mechanism ensures that power is evenly transmitted to each hollow pulley. The rotation of the hollow pulley is the rotation of the top cover, which pushes the slider to perform linear motion in the regular hexagonal groove on the chassis through the straight slot at the back thereof, thereby changing the size of the area enclosed by the six sliders, that is, changing the cross-sectional area of ​​the Helmholtz resonator neck tube. From the vertical perspective, gear transmission is used to achieve multi-stage transmission, which has the advantage of high transmission accuracy. When the shaft rotates, it drives the active pulley and the large gear to rotate at the same time, so that power can be transmitted upward along the longitudinal direction through the large gear, and the Helmholtz resonators in other rows can also be synchronously controlled; the frequency modulation structure of the frequency-adjustable Helmholtz resonator is located at the sound wave incident aperture, which is different from the frequency modulation position of most Helmholtz resonators. The frequency modulation at this position does not take up too much volume and has a compact structure. The integrated control of the entire wall can be completed by only one motor; at the same time, it is made of rigid materials and has high structural strength, and has great application potential in performance halls and architectural acoustics. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a front view of a Helmholtz resonance sound-absorbing wall with adjustable aperture size according to the present invention;

[0016] Figure 2 This is a side view of a Helmholtz resonance sound-absorbing wall with adjustable aperture size according to the present invention;

[0017] Figure 3 This is a rear view of a Helmholtz resonance sound-absorbing wall with adjustable aperture size according to the present invention;

[0018] Figure 4This is a schematic diagram of a chassis in a Helmholtz resonance type sound-absorbing wall with adjustable aperture size according to the present invention;

[0019] Figure 5 This is a schematic diagram of a slider in a Helmholtz resonance type sound-absorbing wall with adjustable aperture size according to the present invention;

[0020] Figure 6 This is a schematic diagram of a top cover in a Helmholtz resonance type sound-absorbing wall with adjustable aperture size according to the present invention;

[0021] Figure 7 This is a schematic diagram of a Helmholtz resonance cavity in a Helmholtz resonance sound-absorbing wall with adjustable aperture size according to the present invention;

[0022] Figure 8 This is a schematic diagram of a slider in a Helmholtz resonance-type sound-absorbing wall with adjustable aperture size assembled on a chassis of the utility model;

[0023] Figure 9 This is a schematic diagram of the assembly of a chassis, a slider, and a top cover in a Helmholtz resonance-type sound-absorbing wall with adjustable aperture size according to the present invention;

[0024] Figure 10 This is a schematic diagram of a frequency-adjustable Helmholtz resonator unit in which a chassis, a slider, and a top cover are assembled from the inside out at the circular aperture of a Helmholtz resonant cavity in a Helmholtz resonant sound-absorbing wall with adjustable aperture size.

[0025] Figure 11 This is a schematic diagram of a chassis and a slider in a Helmholtz resonance-type sound-absorbing wall with adjustable aperture size in the utility model during the frequency modulation process;

[0026] Figure 12 This is a cross-sectional view of the chassis, slider, and top cover of a Helmholtz resonance-type sound-absorbing wall with adjustable aperture size during the frequency modulation process of the utility model;

[0027] Reference numerals:

[0028] 1-frequency-adjustable Helmholtz resonator; 11-chassis; 111-circular through-hole; 112-regular hexagonal groove; 12-slider; 121-cylindrical protrusion; 122-cuboid protrusion; 13-top cover; 131-circular hole; 132-straight notch; 133-hollow pulley; 134-cylindrical thin-walled; 14-Helmholtz resonator; 141-circular aperture; 2-power transmission mechanism; 21-driving pulley; 211-pulley shaft hole; 22-transmission belt; 23-large gear; 231-gear shaft hole; 24-pinion; 241-limiting hole; 25-pinion limiter; 26-rotating shaft; 27-motor; 28-motor stand; DETAILED DESCRIPTION

[0029] To make the purpose, technical solutions, and advantages of the present invention more clear, the following will be combined with the accompanying drawings to clearly and completely describe the technical solutions of the present invention. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0030] Example 1: Figure 1-3 The front, side, and back views shown, as a specific embodiment of the present invention, disclose a Helmholtz resonance-type sound-absorbing wall with adjustable aperture size. This wall can be modified to absorb everyday mid- and low-frequency noise, and is suitable for use in architectural acoustics. The Helmholtz resonance-type sound-absorbing wall with adjustable aperture size comprises a frequency-adjustable Helmholtz resonator 1 and a power transmission mechanism 2.

[0031] like Figure 4-7 1 is a schematic diagram of the various parts that make up the frequency-adjustable Helmholtz resonator 1; the frequency-adjustable Helmholtz resonator 1 includes: a chassis 11, a slider 12, a top cover 13 and a Helmholtz resonance cavity 14; the chassis 11 is a cylinder, and a circular through hole 111 is provided at the center of the circle, and a regular hexagonal groove 112 is provided outside the circular through hole 111, and the geometric centers of the two are at the same position; the slider 12 is a pentagonal thin plate, the upper half of which is an isosceles triangle and the lower half is a rectangle, wherein a cylindrical protrusion 121 is provided at the lower rectangular position of the front end face of the slider 12, and a rectangular protrusion 122 is provided at the lower rectangular position of the rear end face, and the rectangular protrusion 122 is located at the bottom corner; a circular hole 131 is provided at the center of the top cover 13, and the rear end is opened. There are six straight slots 132, the front end of the top cover 13 is a hollow pulley 133, and the rear end is a cylindrical thin wall 134; the Helmholtz resonance cavity 14 is a hollow rectangular parallelepiped, and a circular aperture 141 is opened at the front end; wherein, the outer circumferential surface of the chassis 11 is fixedly connected to the circumferential surface of the circular aperture 141, and the rear end surface of the chassis 11 coincides with the inner wall surface of the Helmholtz resonance cavity 14; the rectangular parallelepiped protrusion 122 is placed in the regular hexagonal groove 112, and the outer surface and the inner wall surface of the regular hexagonal groove 112 fit together seamlessly, and the cylindrical protrusion 121 is placed inside the straight slot 132; the top cover 13 is inserted into the circular aperture 141, the circular hole 131 is opposite the circular through hole 111, and the hollow pulley 133 is exposed outside the circular aperture 141.

[0032] like Figure 8-10This is a schematic diagram of the assembly process of a frequency-adjustable Helmholtz resonator 1 unit. First, the rectangular protrusion 122 of the slider 12 is placed within the regular hexagonal groove 112 of the chassis 11, with the four sides fitting snugly around the regular hexagonal groove 112 without any gaps, allowing the slider 12 to slide relative to the chassis 11. Next, the top cover 13 is placed over the combination of the slider 12 and chassis 11, with the cylindrical thin wall 134 precisely enveloping the slider 12 and chassis 11. At this point, the six straight slots 132 at the rear end of the top cover 13 fit over the cylindrical protrusion 121 of the slider 12, and the straight slots 132 and the cylindrical protrusion 121 are of equal width and height, leaving the hollow pulley 133 exposed outside the circular aperture 141. Finally, the outer circumferential surface of the chassis 11 is fixedly bonded to the circumferential surface of the circular aperture 141 of the Helmholtz resonance cavity 14, and the rear end surface of the chassis 11 coincides with the inner wall surface of the Helmholtz resonance cavity 14. At this point, the frequency-adjustable Helmholtz resonator 1 unit is assembled, which is easy to process and simple to match.

[0033] The power transmission mechanism 2 includes: a driving pulley 21, a transmission belt 22, a large gear 23, a small gear 24, a small gear limiter 25, a rotating shaft 26, a motor 27, and a motor stand 28; the driving pulley 21 is a cylinder with a pulley shaft hole 211 in the center; the transmission belt 22 is tightly sleeved on the hollow pulley 133 and the driving pulley 21; the large gear 23 has a gear shaft hole 231 in the center; the small gear 24 has a limit hole 241 in the center; the large gear 23 The pinion 24 is meshed with each other, and the pinion 24 is arranged directly above the large gear 23; the pinion limiter 25 is "U"-shaped, with both ends fixedly connected to the wall of the Helmholtz resonance cavity 14, and the middle part passes through the limit hole 241; one end of the rotating shaft 26 is fixedly inserted in the pulley shaft hole 211, and the other end is fixedly inserted in the gear shaft hole 231; the motor 27 is fixedly connected to the surface of the motor table 28, and the motor output shaft is fixedly welded to the rotating shaft 26.

[0034] The motor 27 controls the forward and reverse rotation of the motor output shaft and the rotating shaft 26, thereby driving the front driving pulley 21 and the large gear 23 at the rear to rotate simultaneously; the horizontal transmission belt 22 drives the entire row of hollow pulleys 133 to rotate together, and the top cover 13 rotates accordingly, and drives the slider 12 to perform linear motion in the regular hexagonal groove 112 on the chassis 11 through the straight slot 132 at its rear end, thereby changing the size of the area enclosed by the six sliders 12; the vertical large gear 23 and the small gear 24 are engaged with each other, and then the large gear 23 drives the rotating shaft 26, thereby driving the front driving pulley 21 to rotate, and the integrated control of the entire wall Helmholtz resonator 1 is completed by a motor 27.

[0035] Several Helmholtz resonators 1 are arrayed horizontally and bonded into a row, and several rows of Helmholtz resonators 1 are arrayed vertically and bonded into a complete Helmholtz resonance sound-absorbing wall with adjustable aperture size.

[0036] The driving pulley 21, the hollow pulley 133, and the large gear 23 have equal pitch circle diameters and equal tooth surface widths; the large gear 23 and the small gear 24 are both spur gears with external meshing; the pulley shaft hole 211, the gear shaft hole 231, and the rotating shaft 26 have equal diameters; the height of the cylindrical protrusion 121 is equal to the depth of the straight slot 132, and the two have the same width; the circular through hole 111 and the circular hole 131 have the same area.

[0037] Figure 11 This is a schematic diagram of chassis 11 and sliders 12 during frequency modulation; from left to right, the acoustic wave incident aperture gradually increases. Sliders 12, limited only by the linear motion of the straight slots 132 at the rear end of top cover 13, can change the size of the area enclosed by the six sliders 12, thereby varying the size of the acoustic wave incident aperture of frequency-modulated Helmholtz resonator 1. This provides the advantages of simple, convenient, and efficient frequency modulation.

[0038] like Figure 12 The above is a schematic diagram of the chassis 11, slider 12, and top cover 13 during the frequency modulation process from the perspective of a cross-sectional view; the motor output shaft rotates forward and reverse, driving the rotating shaft 26, and the driving pulley 21 and large gear 23 located on the rotating shaft 26 rotate accordingly. The driving pulley 21 rotates to provide power to the belt transmission mechanism. Under the action of the belt transmission, the hollow pulley 133 is rotated, thereby changing the position of the cylindrical protrusion 121 in the straight slot 132, and ultimately changing the position of the slider 12 in the regular hexagonal groove 112. As shown in the cross-sectional view, the cylindrical protrusion 121 continuously slides in the straight slot 132, and the slider 12 also continuously moves in the regular hexagonal groove 112. The entire frequency modulation operation can be fully controlled by only one motor 27, with a compact structure and intelligent frequency modulation.

[0039] The driving pulley 21 and the large gear 23 are axially positioned with the rotating shaft 26 using keyways to prevent axial displacement on the rotating shaft 26. The pinion stopper 25 is fixedly connected to the wall of the Helmholtz resonance cavity 14 at both ends, and the middle portion passes through the stopper hole 241, which can enhance the stability of the entire structure and the accuracy of the power transmission mechanism 2.

[0040] A Helmholtz resonance sound-absorbing wall with adjustable aperture size needs to have certain strength and rigidity and avoid acoustic-solid coupling. Its constituent materials should be rigid materials, including concrete, steel, and aluminum alloy.

[0041] Finally, it should be noted that the above content is only used to illustrate the technical solution of the utility model, rather than to limit the scope of protection of the utility model. Simple modifications or equivalent replacements of the technical solution of the utility model by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the utility model.

Claims

1. A Helmholtz resonance sound-absorbing wall with adjustable aperture, characterized in that: include: A frequency-adjustable Helmholtz resonator (1) and a power transmission mechanism (2); The frequency-adjustable Helmholtz resonator (1) comprises: a chassis (11), a slider (12), a top cover (13) and a Helmholtz resonance cavity (14); the chassis (11) is a circular plate, a circular through hole (111) is provided at the center of the circle, a regular hexagonal groove (112) is provided outside the circular through hole (111), and the geometric centers of the two are at the same position; the slider (12) is a pentagonal thin plate, the upper half of which is an isosceles triangle and the lower half is a rectangle, wherein a cylindrical protrusion (121) is provided at a rectangular position below the front end surface of the slider (12), and a rectangular protrusion (122) is provided at a rectangular position below the rear end surface, and the rectangular protrusion (122) is located at the bottom corner; a circular hole (131) is provided at the center of the circle of the top cover (13), and six straight notches (132) are provided at the rear end, and the top cover (13 ) has a front end portion that is a hollow pulley (133) and a rear end portion that is a cylindrical thin wall (134); the Helmholtz resonance cavity (14) is a hollow rectangular parallelepiped, and a circular aperture (141) is provided at the front end; wherein the outer circumferential surface of the chassis (11) is fixedly connected to the circumferential surface of the circular aperture (141), and the rear end surface of the chassis (11) coincides with the inner wall surface of the Helmholtz resonance cavity (14); the rectangular parallelepiped convex The protrusion (122) is placed in the regular hexagonal groove (112), and the outer surface and the inner wall of the regular hexagonal groove (112) are fitted together without a gap, and the cylindrical protrusion (121) is placed inside the straight notch (132); the top cover (13) is inserted into the circular aperture (141), the circular hole (131) is opposite to the circular through hole (111), and the hollow pulley (133) is exposed outside the circular aperture (141); The power transmission mechanism (2) comprises: a driving pulley (21), a transmission belt (22), a large gear (23), a small gear (24), a small gear stopper (25), a rotating shaft (26), a motor (27), and a motor stand (28); the driving pulley (21) is a cylinder with a pulley shaft hole (211) at the center; the transmission belt (22) is tightly sleeved on the hollow pulley (133) and the driving pulley (21); the large gear (23) has a gear shaft hole (231) at the center; the small gear (24) has a limit hole (241) at the center. ); the large gear (23) and the small gear (24) are meshed with each other, and the small gear (24) is arranged directly above the large gear (23); the small gear limiter (25) is "U"-shaped, with both ends fixedly connected to the wall surface of the Helmholtz resonance cavity (14), and the middle part passes through the limit hole (241); one end of the rotating shaft (26) is fixedly inserted in the pulley shaft hole (211), and the other end is fixedly inserted in the gear shaft hole (231); the motor (27) is fixedly connected to the table surface of the motor table (28), and the motor output shaft and the rotating shaft (26) are fixedly welded together; The motor (27) controls the motor output shaft and the rotating shaft (26) to rotate forward and reverse, thereby driving the front driving pulley (21) and the rear large gear (23) to rotate simultaneously; the horizontal transmission belt (22) drives the entire row of hollow pulleys (133) to rotate together, and the top cover (13) rotates accordingly, and drives the slider (12) to perform linear motion in the regular hexagonal groove (112) on the chassis (11) through the straight notch (132) at its rear end, thereby changing the size of the area surrounded by the six sliders (12); the vertical large gear (23) and the small gear (24) are meshed with each other, and then the large gear (23) drives the rotating shaft (26), thereby driving the front driving pulley (21) to rotate, and all the Helmholtz resonators (1) of the sound absorption wall are uniformly controlled by one motor (27); Helmholtz resonators (1) of the same size are bonded horizontally to form a row, and several rows of Helmholtz resonators (1) are bonded vertically to form a complete Helmholtz resonance sound-absorbing wall with adjustable aperture size.

2. The Helmholtz resonance sound-absorbing wall with adjustable aperture according to claim 1, characterized in that: The driving pulley (21), the hollow pulley (133), and the large gear (23) have equal pitch circle diameters and equal tooth surface widths; the large gear (23) and the small gear (24) are both spur gears with external meshing; the pulley shaft hole (211), the gear shaft hole (231), and the rotating shaft (26) have equal diameters; the height of the cylindrical protrusion (121) is equal to the depth of the straight notch (132), and the two have the same width; the circular through hole (111) and the circular hole (131) have the same area.

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