Resonance state time division multiplexing sound absorber with wireless remote control and variable noise reduction frequency spectrum

Abstract

The invention belongs to the technical field of sound absorbers, and particularly relates to a wireless remote control and variable noise reduction frequency spectrum resonance state time division multiplexing sound absorber which comprises an electromechanical coupling device and a voltage generator. The tail end of the electric control switch is respectively connected with each input end of the parallel multi-branch series circuit, and the tail end of the parallel multi-branch series circuit is grounded; the head end combination position of the electric control switch is connected with the electromechanical coupling device through an electric wire, the input end of the voltage generator is further connected with the wireless communication module, and the tail end of the wireless communication module is grounded. And the circuit switch is connected with different shunt circuits, so that the sound absorber is in different resonance states and obtains corresponding local noise reduction frequency spectrums. The switch array is controlled through the wireless receiving module, so that noise reduction frequency spectrums take effect in sequence, and the broadband sound absorption effect can be achieved. The duty ratio of the local noise reduction frequency spectrum is adjusted through the wireless module, so that frequency spectrum matching of frequency spectrum variable noise can be realized, and optimal noise reduction is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of sound absorbers, and in particular relates to a resonance state time-division multiplexing sound absorber capable of wireless remote control and variable noise reduction spectrum. Background Art

[0002] A low-noise environment will be an indispensable condition to meet people's growing demand for a beautiful ecological environment. On the other hand, soft qualities such as sound quality are becoming increasingly important for products to gain market competitive advantages. Sound absorption theory and technology are the foundation of noise control. In the field of noise control, low-frequency and broadband sound absorption of finite volume absorbers is one of the most important issues.

[0003] Traditional sound absorbing materials are mainly divided into two categories: porous sound absorbing materials and resonant sound absorbing structures. Resonant sound absorbing structures are mainly divided into thin film resonant structures, thin plate resonant structures and ordinary perforated plate resonant structures. Due to size limitations, common porous sound absorbing materials are generally only effective in medium and high frequencies. In order to solve the problem of broadband noise reduction at low frequencies, a relatively broadband composite sound absorber, such as a Helmholtz resonator array, is usually obtained by spatially parallel or series resonant structures. Due to the overly complex structure of the composite sound absorber, its sound absorption spectrum is very sensitive to mechanical and spatial parameters, making it impossible to apply it on a large scale. Whether it is traditional sound absorbing materials and structures or cutting-edge metamaterials and superstructures, their sound absorption spectrum mainly depends on the static parameter design in mechanical and spatial dimensions, and their noise reduction spectrum is generally fixed. However, the bandwidth and energy distribution of the sound power spectrum of fans and motors generally depend on their speed, and their noise spectrum changes with the working conditions. After the static sound absorber design is completed, its sound absorption spectrum curve is difficult to adjust, and it is not competent for variable noise absorption. Changes in the working conditions of the sound source may even make it fail. These factors make it impossible for current static sound absorbers to match the spectrum of variable noise sources well, and therefore cannot achieve the optimal noise reduction effect. Summary of the invention

[0004] In order to solve the above technical problems, the present invention proposes a resonant state time-sharing multiplexing sound absorber with wireless remote control and variable noise reduction spectrum. The switching circuit is used to achieve variable noise spectrum matching, and time-sharing multiplexing sound absorption is achieved by changing the circuit parameters. By switching the shunt circuit branches on and off at a certain time sequence, different acoustic impedances at different times can be obtained, thereby achieving a broadband sound absorption effect, that is, without being affected by various sound source conditions, the sound absorption spectrum can still be changed by adjusting the circuit parameters.

[0005] The resonant state time-division multiplexing sound absorber capable of wireless remote control and variable noise reduction spectrum of the present invention comprises an electromechanical coupling device and a voltage generator, wherein the voltage generator is respectively connected to the head ends of each electric control switch through wires, the end of the electric control switch is respectively connected to the input ends of the parallel multi-branch circuit, and the end of the parallel multi-branch circuit is grounded; the merging point of the head ends of the electric control switches is connected to the electromechanical coupling device through wires, the input end of the voltage generator is also connected to the wireless communication module, and the end of the wireless communication module is grounded.

[0006] Each branch of the parallel multi-branch circuit is formed by connecting a resistor, an inductor and a capacitor in series in sequence.

[0007] The combined output end of the parallel multi-branch circuit is connected to the input end of the negative impedance circuit, and the end of the negative impedance circuit is grounded.

[0008] The negative impedance circuit is composed of an operational amplifier and a peripheral circuit.

[0009] The electromechanical coupling device includes a shell with an open end face, and the open end face of the shell is provided with two symmetrical folded rings connected to a diaphragm covering the end face. The diaphragm is provided with a conductive coil symmetrically attached to the diaphragm, a permanent magnet providing a DC magnetic field, and a magnetic core in sequence.

[0010] The electronically controlled switch is a Hall switch.

[0011] The beneficial effects of the present invention are:

[0012] Compared with the prior art, the present invention controls the acoustic impedance of the sound absorber through a switch circuit, thereby optimizing the absorption of noise with a variable spectrum. The circuit parameters can be selected through a wireless communication module to change its sound absorption spectrum, and the shunt circuit branches can be turned on and off at a certain time sequence to obtain different acoustic impedances at different times, thereby achieving a broadband sound absorption effect. It can also be considered that under different working conditions, the sound absorption spectrum will not be affected by it, and the use of the present invention can achieve variable noise source spectrum matching. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0014] Figure 1 Schematic diagram of the whole sound absorber in the embodiment.

[0015] Figure 2 Graph showing the sound absorption spectrum of the sound absorber in the embodiment.

[0016] 1-folding ring, 2-diaphragm, 3-conductive coil, 4-permanent magnet, 5-magnetic core, 6-electromechanical coupling device, 7-wireless communication module, 8-voltage generator, 9-electrically controlled switch, 10-parallel multi-branch circuit, 11-negative impedance circuit. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0018] Example 1

[0019] See also Figure 1 As shown, a resonant state time-sharing multiplexing sound absorber with wireless remote control and variable noise reduction spectrum includes an electromechanical coupling device 6 and a voltage generator 8. The electromechanical coupling device 6 includes a shell with an end face open, and the end face of the shell opening is provided with two symmetrical folded rings 1 connected to a diaphragm 2 covering the end face. The diaphragm 2 is provided with a conductive coil 3 symmetrically attached to the diaphragm 2, a permanent magnet 4 providing a DC magnetic field, and a magnetic core 5 in sequence.

[0020] The voltage generator 8 is connected to the head end of each electric control switch 9 through wires. The electric control switch 9 is a Hall switch. The electric control switch 9 is implemented by field effect (S1-Sn). The end of the electric control switch 9 is connected to the input ends of the parallel multi-branch circuit 10 respectively. Each branch of the parallel multi-branch circuit 10 is composed of a resistor, an inductor, and a capacitor connected in series in sequence. The combined output end of the parallel multi-branch circuit 10 is connected to the input end of the negative impedance circuit 11. The negative impedance circuit 11 is composed of an operational amplifier and a peripheral circuit, and the end of the negative impedance circuit 11 is grounded; the head end of the electric control switch 9 is connected to one of the guide coils through a wire, and the other conductive coil 3 is grounded. The input end of the voltage generator 8 is also connected to the wireless communication module 7, and the end of the wireless communication module 7 is grounded.

[0021] The resonance state of the sound absorber is determined by the circuit and the mechanical parameters of the diaphragm 2. By selecting different branches to be connected through the electric control switch 9, the diaphragm 2 can be placed at different resonance frequencies, and the diaphragm 2 can effectively absorb noise near the resonance frequency.

[0022] The voltage generator 8 can generate multi-channel low-voltage (2V to 30V) direct current for controlling the on and off of the electronically controlled switch 9 and selecting a circuit branch to be turned on. The turning on of different circuit branches corresponds to effective sound absorption of different frequency bands.

[0023] The voltage generator 8 can generate a multi-channel square wave, the low voltage of the square wave is less than 1.5 volts, and the high voltage is in the range of 2 volts to 30 volts. Each channel is connected to an electric control switch 9, which is turned on at high voltage and turned off at low voltage, or vice versa. Thus, the circuit branch connected to the electric control switch 9 and the coil are closed or disconnected as the square wave changes.

[0024] The wireless communication module 7 is used to receive the control signal and control one or more channels of the voltage generator 8 to generate the required voltage, so as to control the on and off of the electric control switch 9.

[0025] Using the no circuit state (state 1) and the single branch circuit state (state 2), setting the circuit on-off cycle to 250Hz, calculate the sound absorption coefficient within 1s. Figure 2 As shown in the figure, the experimental data show that the sound absorption spectrum of the sound absorber can be obviously changed by changing the duty cycle of the circuit, that is, the state of the diaphragm 2. That is, when different incident sound waves push the diaphragm 2, different sound absorption spectra will be generated. It can also be considered that under different sound source conditions, the noise source spectrum matching can continue to be achieved.

[0026] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all details in detail, nor do they limit the invention to only the specific embodiments described. Obviously, many modifications and changes can be made according to the content of this specification.

Claims

1. A resonant state time-division multiplexing sound absorber capable of wireless remote control and variable noise reduction spectrum, comprising an electromechanical coupling device (6) and a voltage generator (8), characterized in that: The voltage generator (8) is connected to the head end of each electric control switch (9) through electric wires, and the end of the electric control switch (9) is connected to the input end of the parallel multi-branch circuit (10) respectively, and the end of the parallel multi-branch circuit (10) is grounded; the head end of the electric control switch (9) is connected to the electromechanical coupling device (6) through electric wires, and the input end of the voltage generator (8) is also connected to the wireless communication module (7), and the end of the wireless communication module (7) is grounded.

2. The resonance state time-division multiplexing sound absorber capable of wireless remote control and variable noise reduction spectrum according to claim 1 is characterized in that: Each branch of the parallel multi-branch circuit (10) is formed by sequentially connecting a resistor, an inductor and a capacitor in series.

3. The resonance state time-division multiplexing sound absorber capable of wireless remote control and variable noise reduction spectrum according to claim 2 is characterized in that: The combined output end of the parallel multi-branch circuit (10) is connected to the input end of the negative impedance circuit (11), and the end of the negative impedance circuit (11) is grounded.

4. The resonance state time-division multiplexing sound absorber capable of wireless remote control and variable noise reduction spectrum according to claim 3 is characterized in that: The negative impedance circuit (11) is composed of an operational amplifier and peripheral circuits.

5. The resonance state time-division multiplexing sound absorber capable of wireless remote control and variable noise reduction spectrum according to claim 1 is characterized in that: The electromechanical coupling device (6) comprises a housing with an open end face, wherein the open end face of the housing is provided with two symmetrical folded rings (1) connected to a diaphragm (2) covering the end face, and the diaphragm (2) is provided with a conductive coil (3) symmetrically attached to the diaphragm (2), a permanent magnet (4) providing a DC magnetic field, and a magnetic core (5) in sequence.

6. The resonance state time-division multiplexing sound absorber capable of wireless remote control and variable noise reduction spectrum according to claim 1 is characterized in that: The electronically controlled switch (9) is a field effect transistor switch.

7. The resonance state time-division multiplexing sound absorber capable of wireless remote control and variable noise reduction spectrum according to claim 6 is characterized in that: The electric control switch (9) is a clarinet switch.

8. The resonance state time-division multiplexing sound absorber capable of wireless remote control and variable noise reduction spectrum according to claim 6 is characterized in that: The electric control switch (9) is a Hall switch.

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