Low-frequency vibration-damping band-gap-adjustable acoustic superstructure

Abstract

The invention relates to a low-frequency vibration-damping band-gap-adjustable acoustic superstructure which is divided into an upper layer and a lower layer. The lower layer is a band gap control part, the upper layer is an acoustic superstructure part, and the upper layer and the lower layer are connected by a cantilever beam through a hinge to realize a rotation function. The superstructure can form an acoustic forbidden band in a relatively low frequency to isolate low-frequency vibration and noise; the acoustic forbidden band position of the acoustic superstructure can be adjusted according to engineering requirements, the band gap position of the superstructure can be changed through movement of the sliding block along with frequency change of vibration noise, and the vibration and noise reduction function is achieved in a target frequency band. The low-frequency damping band gap adjustable acoustic superstructure is simple in design, and the used materials are common materials and are easy to process and produce; the effective acting length of the cantilever beam of the superstructure is changed by moving the sliding block, so that the band gap of the superstructure is changed, adjustable control over the band gap of the acoustic superstructure is achieved, the adjustable function of the band gap of the acoustic superstructure is achieved, the acting band gap of the acoustic superstructure is widened, and compared with a traditional acoustic superstructure, the acoustic superstructure is greatly improved.

Description

Technical Field

[0001] The invention belongs to the technical field of passenger vehicles, and in particular relates to an acoustic superstructure with an adjustable low-frequency vibration-damping band gap. Background Art

[0002] my country's passenger car market is undergoing significant changes, and the development of the automobile industry has entered a green, coordinated and connotative development stage. This has put forward increasingly stringent requirements for automobile noise, vibration and harshness (Noise, Vibration & Harshness), making the NVH performance of automobiles increasingly important and becoming one of the important indicators for measuring automobile quality. Although the automobile industry has made significant progress in improving overall NVH performance, it has not yet achieved satisfactory results in controlling low-frequency noise in the car.

[0003] At present, the means of suppressing noise inside the car mainly include the use of sound-absorbing and insulating materials such as rubber, foam and other elastically deformable materials. However, these materials have relatively weak isolation capabilities for low-frequency vibrations and are easily affected by aging, resulting in a decrease in effectiveness after long-term use. Another common vibration suppression method is to use dynamic vibration absorbers, which can effectively reduce vibrations. However, dynamic vibration absorbers can only work in a very narrow frequency band near the natural frequency, and the accuracy requirements are very high. In addition, when using dynamic vibration absorbers, superimposed use will increase the difficulty of layout. Therefore, there are certain limitations in actual engineering applications. Traditional materials and vibration suppression methods have limitations in solving the problem of low-frequency noise inside the car. Therefore, more innovative and effective technical means are needed to meet this challenge.

[0004] An acoustic superstructure is a composite structure or composite material with extraordinary physical properties. Through special design or arrangement of the structure, it can obtain unusual acoustic properties that are not found in nature, such as reducing vibration noise, sound focusing, sound reflection, etc. A limitation of traditional acoustic superstructures is that once the structural design is completed, the position and width of its band gap are determined, and the band gap width is generally narrow, which cannot effectively reduce vibration and noise in a wide frequency band. Based on this, it is urgent to develop an acoustic superstructure with adjustable band gap to effectively solve the above problems. Summary of the invention

[0005] The purpose of the present invention is to provide a low-frequency vibration-damping band gap adjustable acoustic superstructure, which realizes the adjustability of the band gap position, so that it can effectively reduce vibration and noise in a wider frequency band to solve the problem of low-frequency vibration noise in the car.

[0006] The objective of the present invention is achieved through the following technical solutions:

[0007] A low-frequency vibration-damping bandgap adjustable acoustic superstructure, which is divided into an upper layer and a lower layer; the lower layer is a bandgap control part, the upper layer is an acoustic superstructure part, and the upper and lower layers are connected by a cantilever beam through a hinge;

[0008] The lower layer is the base plate control part, which is composed of a stepper motor 1, a base plate 2, a screw rod 3 and a slider 4. The slider 4 is connected to the base plate 2 through the screw rod 3. The stepper motor 1 drives the screw rod 3 to rotate, and the screw rod 3 drives the slider 4 to move left and right and move in the groove of the base plate 2;

[0009] The upper layer is an acoustic superstructure, which is composed of a cantilever beam 5, a hinge 6 and a mass vibrator 7. The two ends of the cantilever beam 5 are respectively connected to the mass vibrator 7 and the base plate 2 or the slider 4. The movement of the slider 4 drives the cantilever beam 5 to move. The acoustic superstructure is symmetrical in the upper and lower parts. The superstructure is connected to the mass vibrator 7 through the hinge 6 through the protruding parts of the two cantilever beams 5, and the other end is connected to the base plate 2 or the slider 4.

[0010] The effective length of the cantilever beam of the superstructure is changed by moving the slider, thereby changing the band gap of the superstructure, thereby achieving adjustable control of the band gap of the acoustic superstructure.

[0011] Furthermore, the base plate 2 is provided with scales to indicate the band gap position.

[0012] Furthermore, the base plate 2, the slider 4, the cantilever beam 5, and the mass vibrator 7 are all made of metal materials such as steel or aluminum.

[0013] Furthermore, the slider 4 and the mass vibrator 7 are square.

[0014] Furthermore, the base plate 2 has a thickness of 5 mm, a length of 200 mm, and a width of 40 mm.

[0015] Furthermore, the cantilever beam 5 has a thickness of 0.5-1.5 mm.

[0016] Furthermore, the movement mode of the slider 4 is driven by the screw rod 3, and the screw rod 3 has a nominal diameter of 2 mm and a length of 160 mm.

[0017] Furthermore, the size of the slider 4 is 35*28 mm and the thickness is 3 mm.

[0018] Furthermore, the size of the mass vibrator 7 is 50*50 mm and the thickness is 1 mm.

[0019] Furthermore, both ends of the cantilever beam 5 are connected by hinges, wherein one end of the cantilever beam 5 is directly connected to the base plate 2 , and the other end is connected to the slider 4 .

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The low-frequency vibration-damping bandgap adjustable acoustic superstructure of the present invention can form an acoustic bandgap at a relatively low frequency to isolate low-frequency vibration and noise;

[0022] 2. The present invention can adjust the acoustic bandgap position of the acoustic superstructure according to engineering needs. As the frequency of the vibration noise changes, the superstructure bandgap position can be changed by moving the slider to achieve vibration reduction and noise reduction functions within the target frequency band;

[0023] 3. The low-frequency vibration reduction band gap adjustable acoustic superstructure has a simple design, and the materials used are all common materials, which are easy to process and produce;

[0024] 4. By moving the slider to change the effective length of the superstructure cantilever beam, the band gap of the superstructure is changed, and the adjustable control of the acoustic superstructure band gap is achieved. The adjustable band gap of the acoustic superstructure is realized, and the effective band gap of the acoustic superstructure is widened, which is a significant improvement compared to traditional acoustic superstructures. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 The overall schematic diagram of the low-frequency vibration-damping bandgap adjustable acoustic superstructure of the present invention;

[0027] Figure 2 It is a front view of the low-frequency vibration-damping bandgap adjustable acoustic superstructure of the present invention;

[0028] Figure 3 It is a schematic diagram of the acoustic superstructure substrate plate with adjustable low-frequency vibration reduction band gap according to the present invention;

[0029] Figure 4 It is a schematic diagram of the acoustic superstructure screw with adjustable low-frequency vibration reduction band gap of the present invention;

[0030] Figure 5 It is a schematic diagram of the acoustic superstructure slider with adjustable low-frequency vibration reduction band gap of the present invention;

[0031] Figure 6 It is a schematic diagram of the low-frequency vibration-damping bandgap adjustable acoustic superstructure cantilever beam of the present invention;

[0032] Figure 7 It is a schematic diagram of the low-frequency vibration-damping bandgap-adjustable acoustic superstructure oscillator of the present invention.

[0033] In the figure, 1. stepper motor 2. base plate 3. screw rod 4. slider 5. cantilever beam 6. hinge 7. mass block oscillator. DETAILED DESCRIPTION

[0034] The present invention will be further described below in conjunction with embodiments:

[0035] like Figure 1 , Figure 3-Figure 7 As shown, the low-frequency vibration reduction bandgap adjustable acoustic superstructure of the present invention is divided into an upper layer and a lower layer. The lower layer is a bandgap control part, and the upper layer is an acoustic superstructure part. The upper and lower layers are connected by a cantilever beam through a hinge to realize the function of rotation.

[0036] The lower layer is the base plate control part, which is composed of a stepper motor 1, a base plate 2, a screw 3 and a slider 4. The slider 4 is connected to the base plate 2 through the screw 3, and the stepper motor 1 drives the screw 3 to rotate, and the screw 3 drives the slider 4 to move left and right, and move in the groove of the base plate 2, thereby changing the equivalent length of the superstructure cantilever beam to change the band gap and realize the precise positioning control of the slider 4. The base plate 2 is provided with a scale to indicate the position of the band gap.

[0037] The upper layer is an acoustic superstructure, which is composed of a cantilever beam 5, a hinge 6 and a mass vibrator 7. The cantilever beam 5 is shaped as follows: Figure 6 As shown, the two ends are respectively connected to the mass block vibrator 7 and the base plate 2 or the slider 4, and the movement of the slider 4 drives the cantilever beam 5 to move.

[0038] In the present invention, the acoustic superstructure is symmetrical in the upper and lower parts, and the superstructure is connected to the mass block vibrator 7 through hinges 6 through the protruding parts of two cantilever beams 5, and the other ends are connected to the base plate 2 or the slider 4 to ensure the vertical state when in the left extreme position. The connection mode of both ends of the cantilever beam 5 is hinge connection. Among them, the end of one cantilever beam 5 is directly connected to the base plate 2, and the other end is connected to the slider 4.

[0039] The effective length of the cantilever beam of the superstructure is changed by moving the slider, thereby changing the band gap of the superstructure, thereby achieving adjustable control of the band gap of the acoustic superstructure.

[0040] The base plate 2, slider 4, cantilever beam 5, and mass vibrator 7 are all made of metal materials such as steel or aluminum. To reduce weight, the base plate 2 and slider 4 can also be made of composite materials or other lightweight materials. The slider 4 and mass vibrator 7 are square. As required, they can also be made into a circle or other shapes, and the specific shape can be set according to requirements.

[0041] The base plate 2 has a thickness of 5 mm, a length of 200 mm, and a width of 40 mm.

[0042] The thickness of the cantilever beam 5 is 0.5-1.5 mm. The thickness or length can be changed as needed to solve the vibration noise problem at different frequencies. The specific thickness and length can be set according to needs.

[0043] The movement mode of the slider 4 is driven by the screw rod 3, and the screw rod 3 has a nominal diameter of 2 mm and a length of 160 mm.

[0044] The size of the slider 4 is 35*28 mm and the thickness is 3 mm.

[0045] The mass vibrator 7 has a size of 50*50 mm and a thickness of 1 mm.

[0046] The present invention realizes the function of adjustable band gap of acoustic superstructure and broadens the effective band gap of acoustic superstructure, which is greatly improved compared with traditional acoustic superstructure.

[0047] Example 1

[0048] like Figure 1 As shown, a low-frequency vibration-damping bandgap adjustable acoustic superstructure is composed of an upper and a lower layer. The lower layer is composed of a stepper motor 1, a base plate 2, a screw 3 and a slider 4. There are scale marks on the base plate 2. The upper layer is an acoustic superstructure. The superstructure is connected to a mass block vibrator 7 by two cantilever beams 5. The other end of one cantilever beam 5 is connected to the base plate 2, and the other cantilever beam 5 is connected to the slider 4.

[0049] The upper and lower layers, the lower layer is the control part, and the upper layer is the acoustic superstructure part. The lower slider controls the superstructure to achieve adjustable band gap.

[0050] The lower layer is the control part, the stepper motor 1 controls the lead screw 3, the lead screw 3 drives the slider 4 to move, and the slider 4 drives the cantilever beam 5 to move, thereby changing the superstructure band gap.

[0051] The upper layer is the superstructure part, which is composed of two cantilever beams 5 and a mass block vibrator 7. The protruding part of the cantilever beam 5 is connected to the mass block vibrator 7. The other end of one cantilever beam 5 is connected to the base plate 2, and the other is connected to the slider 4. The equivalent length of the superstructure cantilever beam 5 is changed by moving the slider 4, thereby changing the band gap.

[0052] The slider 4 controls two cantilever beams 5, and the cantilever beams 5 are connected to the slider 4 and the base plate 2 via a hinge 6. The base plate 2 is marked with scales to indicate the position of the band gap.

[0053] The cantilever beam 5 has a shape of , and the cantilever beams 5 are connected by hinges 6 , and the cantilever beam 5 and the mass block vibrator 7 are connected by hinges 6 .

[0054] The size of the base plate 2 is 200*40mm, the thickness is 5mm, and the internal groove is 4mm deep; the diameter of the screw rod 3 is 2mm and the length is 160mm; the size of the slider 4 is 35*25mm and the thickness is 3mm; the size of the cantilever beam 5 is 100*10mm, the thickness is 1mm, and the protruding part size is 20*10mm; the size of the mass block vibrator 7 is 50*50mm, the thickness is 1mm, and the hinge diameter is 5mm.

[0055] The slider 4 moves through the screw rod 3 and drives the cantilever beam 5 to rotate through the hinge, thereby changing the equivalent length of the superstructure cantilever beam and moving the superstructure action band gap, forming an acoustic bandgap effect in a wider frequency band.

[0056] In practical applications, the structural size, shape, bandgap frequency, etc. of the present invention can be designed according to engineering requirements to achieve the purpose of production.

[0057] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A low-frequency vibration-damping bandgap adjustable acoustic superstructure, characterized in that: It is divided into two layers, an upper layer and a lower layer; the lower layer is a band gap control part, the upper layer is an acoustic superstructure part, and the upper and lower layers are connected by a cantilever beam through a hinge; The lower layer is a base plate control part, which is composed of a stepping motor (1), a base plate (2), a screw rod (3) and a slider (4); the slider (4) is connected to the base plate (2) through the screw rod (3), the stepping motor (1) drives the screw rod (3) to rotate, and the screw rod (3) drives the slider 4 to move left and right, and moves in the groove of the base plate (2); The upper layer is an acoustic superstructure part, which is composed of a cantilever beam (5), a hinge (6) and a mass vibrator (7). The two ends of the cantilever beam (5) are respectively connected to the mass vibrator (7) and the base plate (2) or the slider (4). The movement of the slider (4) drives the cantilever beam 5 to move. The acoustic superstructure part is symmetrical in the upper and lower parts. The superstructure is connected to the mass vibrator (7) through the hinge (6) through the protruding parts of the two cantilever beams (5), and the other end is connected to the base plate (5) or the slider (4). The effective length of the cantilever beam of the superstructure is changed by moving the slider, thereby changing the band gap of the superstructure, thereby achieving adjustable control of the band gap of the acoustic superstructure.

2. The low-frequency vibration-damping bandgap adjustable acoustic superstructure according to claim 1, characterized in that: The base plate (2) is provided with scales to indicate the band gap position.

3. The low-frequency vibration-damping bandgap adjustable acoustic superstructure according to claim 1, characterized in that: The base plate (2), the slider (4), the cantilever beam (5) and the mass block vibrator (7) are all made of metal materials such as steel or aluminum.

4. The low-frequency vibration-damping bandgap adjustable acoustic superstructure according to claim 1, characterized in that: The sliding block (4) and the mass block vibrator (7) are square.

5. The low-frequency vibration-damping bandgap adjustable acoustic superstructure according to claim 1, characterized in that: The base plate (2) has a thickness of 5 mm, a length of 200 mm and a width of 40 mm.

6. The low-frequency vibration-damping bandgap adjustable acoustic superstructure according to claim 1, characterized in that: The thickness of the cantilever beam (5) is 0.5-1.5 mm.

7. The low-frequency vibration-damping bandgap adjustable acoustic superstructure according to claim 1, characterized in that: The movement mode of the slider (4) is driven by a screw rod (3), the screw rod (3) has a nominal diameter of 2 mm and a length of 160 mm.

8. The low-frequency vibration-damping bandgap adjustable acoustic superstructure according to claim 1, characterized in that: The size of the slider (4) is 35*28 mm and the thickness is 3 mm.

9. The low-frequency vibration-damping bandgap adjustable acoustic superstructure according to claim 1, characterized in that: The mass block vibrator (7) has a size of 50*50 mm and a thickness of 1 mm.

10. The low-frequency vibration-damping bandgap adjustable acoustic superstructure according to claim 1, characterized in that: The two ends of the cantilever beam (5) are connected by hinges, wherein one end of the cantilever beam (5) is directly connected to the base plate (2), and the other end is connected to the slider (4).

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