A mechanical wave based magnetic field generator

Abstract

The utility model discloses a kind of magnetic field generator based on mechanical wave, it is related to electromagnetic induction technical field, the utility model is by being arranged between ultrasonic wave transmitting unit and magnet cantilever beam of strip structure, when ultrasonic wave transmitting unit sends ultrasonic wave, when the frequency of ultrasonic wave and the natural frequency of cantilever beam match consistent, cantilever beam will appear resonance phenomenon with ultrasonic wave, it can be based on the resonance enhancement characteristics of cantilever beam, in the divergent space surrounded by cantilever beam, the amplitude of ultrasonic wave is caused to increase, to drive magnet substantially moves, produce the alternating magnetic field of higher magnetic field intensity, it can be widely applied in ultrasonic wave transducer and many other fields.

Description

Technical Field

[0001] This utility model relates to the field of electromagnetic induction technology, and in particular to a magnetic field generator based on mechanical waves. Background Technology

[0002] Mechanical waves are mechanical vibrations that propagate in a medium, such as ultrasound and sound waves. They are essentially a form of energy propagation that can carry energy and interact with matter. When mechanical waves (such as ultrasound) propagate in a magnetostrictive material, they generate periodic mechanical vibrations, which cause alternating mechanical stresses to be generated inside the material. Through the magnetostrictive effect, these alternating stresses are converted into alternating magnetic fields.

[0003] At present, traditional mechanical-magnetic transducers, such as magnetic field generators combined with motors, work on the principle that the rotation of the motor causes the magnet to move rapidly, thereby generating a magnetic field. This method of generating a magnetic field requires the motor to reach a high speed within a certain period of time so that the magnet can quickly cut the magnetic field lines. However, since the motor speed itself has an upper limit, such as a 2-pole motor with a rated speed of 120,000 rpm and an operating frequency of 2000 Hz, the magnetic field strength generated is limited.

[0004] Therefore, current mechanical wave-based magnetic field generators, due to the limitations of the devices themselves, produce relatively low magnetic field strengths, making it difficult to meet the current requirements for high magnetic field applications. Utility Model Content

[0005] This utility model provides a mechanical wave-based magnetic field generator, which can solve the problem that existing mechanical wave-based magnetic field generators have limitations that result in low magnetic field strength, making it difficult to meet the current requirements for high magnetic field applications.

[0006] This utility model embodiment provides a magnetic field generator based on mechanical waves, including an ultrasonic transmitting unit, a cantilever beam disposed on one side of the ultrasonic transmitting unit, and a magnet disposed on the other side of the cantilever beam; The ultrasonic transmitting unit emits ultrasonic waves toward the cantilever beam, which amplifies the amplitude of the ultrasonic waves. The magnet moves under the action of the amplified ultrasonic waves to generate an alternating magnetic field and emits a magnetic field signal outward.

[0007] Preferably, it also includes a single-axis magnetometer and a power supply; The uniaxial magnetometer is used to measure the magnetic field strength of the alternating magnetic field generated by the magnet; The power supply is used to power the ultrasonic transmitting unit and the single-axis magnetometer.

[0008] Preferably, the ultrasonic transmitting unit includes a signal generator, a power amplifier, and a piezoelectric transducer; The signal generator is used to generate high-frequency electrical signals; The power amplifier is used to amplify the electrical signal to drive power; The piezoelectric transducer is used to convert the electrical energy of an electrical signal into mechanical vibration, thereby generating ultrasonic waves.

[0009] Preferably, the cantilever beam is made of alloy structural steel 30CrMnSi or spring steel 65Mn.

[0010] Preferably, the magnet is an N52 neodymium iron boron magnet, which generates an alternating magnetic field through magnetostriction or magnetoelastic coupling under the action of ultrasound.

[0011] This utility model embodiment provides a magnetic field generator based on mechanical waves, which has the following advantages compared with the prior art: This invention features a long cantilever beam between an ultrasonic transmitting unit and a magnet. When the ultrasonic transmitting unit emits ultrasonic waves, and the frequency of the ultrasonic waves matches the natural frequency of the cantilever beam, the cantilever beam resonates with the ultrasonic waves. Based on the resonance enhancement characteristics of the cantilever beam, the amplitude of the ultrasonic waves is increased in the divergent space enclosed by the cantilever beam, thereby driving the magnet to move significantly and generating an alternating magnetic field with higher magnetic field strength. This invention can be widely used in many fields such as ultrasonic transducers. Attached Figure Description

[0012] Figure 1 A schematic diagram of the principle of a magnetic field generator based on mechanical waves provided for an embodiment of this utility model; Figure 2 A schematic diagram of a cantilever beam simulation model of a magnetic field generator based on mechanical waves, provided for an embodiment of this utility model. Detailed Implementation

[0013] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0014] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0015] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0016] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0017] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0018] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0019] See Figure 1 This utility model embodiment provides a magnetic field generator based on mechanical waves. It utilizes the mechanical energy of ultrasound to drive a magnet to generate displacement, emitting an alternating magnetic field to complete the conversion of mechanical energy into magnetic field. Furthermore, it uses aerogel to enhance the amplitude of the ultrasound waves, further strengthening the generated magnetic field and thus improving the conversion efficiency from mechanical energy to magnetic energy. Specifically, it consists of the following modules: 1. Ultrasonic transmitting unit: Signal generator: generates high-frequency electrical signals (0.1-20MHz) and sets the ultrasonic frequency and amplitude.

[0020] Power amplifier: Amplifies the electrical signal to the driving power (10-200W) to ensure that the transducer outputs sufficient mechanical energy.

[0021] Piezoelectric transducers: Based on the inverse piezoelectric effect, they convert electrical energy into mechanical vibrations to generate ultrasonic waves.

[0022] 2. Cantilever beam: Mechanical structures increase the amplitude of ultrasonic waves, thereby increasing the magnetic field strength.

[0023] 3. Magnetic Energy Conversion Module: Permanent magnet (N52 neodymium iron boron): Receives ultrasonic mechanical vibrations and converts them into alternating magnetic field fluctuations through magnetostrictive effect or magnetoelastic coupling.

[0024] 4. Magnetic field detection unit: Single-axis magnetometer: Based on the Hall effect or magnetoresistive effect, it measures the magnetic field strength at a distance (0.5m) (resolution 0.1μT) and quantifies the energy conversion efficiency.

[0025] The specific work process is as follows: First, an arbitrary waveform generator produces a signal of a certain frequency. This signal is then amplified by a power amplifier to generate ultrasonic waves of the same frequency. Ultrasonic waves are mechanical waves and require a medium to propagate. Due to the uncertainty of the medium, ultrasonic waves experience varying degrees of attenuation during transmission. The attenuation of ultrasonic waves in air is primarily caused by the continuous friction, collision, and heat exchange between vibrating particles, leading to the loss of acoustic energy.

[0026] The attenuation coefficient of ultrasound in air can be expressed by the ultrasound attenuation equation: .

[0027] Where: β represents the attenuation coefficient of ultrasound in air; V represents the speed of ultrasound; ρ represents the density of the propagation medium; f represents the frequency of ultrasound; and η represents the dynamic viscosity of air.

[0028] As can be seen from the above formula, when ultrasound propagates in the air, the air density is constant, and the wave speed of ultrasound is also constant. When the ambient temperature is constant, the attenuation coefficient of ultrasound in the air is proportional to the frequency of ultrasound. That is, the higher the frequency emitted by the ultrasound generator, the greater the attenuation coefficient of ultrasound. In order to ensure the amplitude of ultrasound and reduce the attenuation of ultrasound, the magnet needs to be as close as possible to the ultrasound generator.

[0029] Secondly, according to the principle of electromagnetic induction, when a conductor in a magnetic field (here, a magnet can be regarded as a special "conductor" with a certain magnetic permeability) moves, it will cause the magnetic field around it to change. The magnetic energy conversion module receives ultrasonic mechanical vibration through a permanent magnet (N52 neodymium iron boron), and generates an alternating magnetic field source through magnetostrictive effect or magnetoelastic coupling. It emits an alternating magnetic field outward, converting mechanical vibration into alternating magnetic field fluctuations, thus completing the conversion of mechanical energy into magnetic energy.

[0030] The vibration of the magnet creates a periodic displacement. (A is amplitude, f is frequency), causing rapid changes in the spatial magnetic field. According to Faraday's law, a changing magnetic field can induce eddy currents or excite electromagnetic effects; the magnetic field strength B is related to the magnet's velocity. Related: ( (where B is the magnetic moment of the magnet), indicating that high frequency and large amplitude can increase B.

[0031] To further enhance the amplitude of the ultrasonic waves and improve the effect of magnetic field changes, a cantilever beam structure is used as the intermediate medium between the ultrasonic generator and the magnet, such as... Figure 2 As shown, by utilizing its resonance enhancement characteristics, the amplitude of the ultrasonic wave is increased, the magnetic field strength is further enhanced, and the energy transfer efficiency is improved; finally, the magnetic field strength is measured using a magnetometer.

[0032] This invention utilizes a cantilever beam mechanical structure to enhance ultrasonic amplitude, thereby increasing magnetic field strength. The cantilever beam is designed to reach a resonant state at the driving frequency (the natural frequency matches the ultrasonic frequency), at which point the amplitude is maximized. The vibration amplitude at the free end of the cantilever beam is much greater than that at the fixed end, approximated by the formula: A_free_end ≈ Q · A_fixed_end, where Q is the quality factor, which is related to material damping.

[0033] This invention underwent specific experiments, as shown in Table 1 (comparison of simulated amplitudes of cantilever beams of different sizes), Table 2 (comparison of simulated amplitudes of cantilever beams of different materials), and Table 3 (comparison of magnetic field strengths). The known parameters are as follows: Magnetic moment m = 3.25 A·m 2 ;amplitude um; observation distance r=10cm; substitute the known parameters into the dynamic magnetic field amplitude formula: ,have to =21.45 uT. The results show that the magnetic field strength is significantly enhanced after adding the cantilever beam structure.

[0034] Table 1 Comparison of simulated amplitudes of cantilever beams of different sizes Table 2 Comparison of simulated amplitudes of cantilever beams made of different materials Table 3 Comparison of magnetic field strength This invention enhances the ultrasonic amplitude by adding a cantilever beam. During the process of converting mechanical energy into magnetic energy, the entire device has a high frequency, a strong magnetic field, and is small in size and low in cost, making it widely applicable.

[0035] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A magnetic field generator based on mechanical waves, characterized in that, include: An ultrasonic transmitting unit, wherein a cantilever beam is provided on one side of the ultrasonic transmitting unit and a magnet is provided on the other side of the cantilever beam; The ultrasonic transmitting unit emits ultrasonic waves toward the cantilever beam, which amplifies the amplitude of the ultrasonic waves. The magnet moves under the action of the amplified ultrasonic waves to generate an alternating magnetic field and emits a magnetic field signal outward.

2. A magnetic field generator based on mechanical waves according to claim 1, characterized in that, It also includes a single-axis magnetometer and a power supply; The uniaxial magnetometer is used to measure the magnetic field strength of the alternating magnetic field generated by the magnet; The power supply is used to power the ultrasonic transmitting unit and the single-axis magnetometer.

3. A magnetic field generator based on mechanical waves according to claim 1, characterized in that, The ultrasonic transmitting unit includes a signal generator, a power amplifier, and a piezoelectric transducer; The signal generator is used to generate high-frequency electrical signals; The power amplifier is used to amplify the electrical signal to drive power; The piezoelectric transducer is used to convert the electrical energy of an electrical signal into mechanical vibration, thereby generating ultrasonic waves.

4. A magnetic field generator based on mechanical waves according to claim 1, characterized in that, The cantilever beam is made of alloy structural steel 30CrMnSi or spring steel 65Mn.

5. A magnetic field generator based on mechanical waves according to claim 1, characterized in that, The magnet is an N52 neodymium iron boron magnet, which generates an alternating magnetic field through magnetostriction or magnetoelastic coupling under the action of ultrasound.

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