TWM448064U - Composite piezoelectric system - Google Patents

Description

Composite piezoelectric system

This work is about a composite piezoelectric system, especially a piezoelectric system that uses both piezoelectric elements to generate vibration and power simultaneously.

Piezoelectric effect refers to a conversion of electrical energy and mechanical energy. This phenomenon was discovered by the Curie brothers in 1880. It was discovered by S. Roberts scholars in 1947 that the residual electric polarization of barium titanate (BaTiO3) ceramics was obtained by S. Roberts scholars. The influence of this has opened up the application and discussion of piezoelectric materials in piezoelectric properties.

The positive piezoelectric effect is essentially a process in which mechanical energy is converted into electrical energy. When the piezoelectric material is subjected to physical pressure, the electric dipole moment in the material body is shortened by compression. At this time, the piezoelectric material resists this change and generates an equal amount of positive and negative charges on the opposite surface of the material to maintain the original state. . This phenomenon of polarization due to deformation is called "positive piezoelectric effect".

The inverse piezoelectric effect is essentially a process in which electrical energy is converted into mechanical energy. When an electric field (voltage) is applied to the surface of the piezoelectric material, the electric dipole moment is elongated by the action of the electric field, and the piezoelectric material resists the change and elongates in the direction of the electric field. This process of mechanical deformation by the action of an electric field is called an "inverse piezoelectric effect."

Generally, the application of a piezoelectric element is generally simply converting mechanical energy into electrical energy or converting electrical energy into mechanical energy; however, since the piezoelectric element can generate vibration by using a voltage, it can also generate electricity by using vibration (causing deformation). In this way, two piezoelectric elements are designed in one system, one as a vibration source and the other as a power source, which utilizes the characteristics of vibration to generate electricity when there are different application variations.

The main purpose of this creation is to provide a composite piezoelectric system that achieves different functions for two piezoelectric elements.

To achieve the above objects, the present invention provides a composite piezoelectric system including a first piezoelectric element, a mass, a second piezoelectric element, and a microstructure output.

The first piezoelectric element is oscillated by a power supply. A proof mass is located between the first piezoelectric element and the second piezoelectric element. The mass conducts oscillation of the first piezoelectric element to the second piezoelectric element to cause the second piezoelectric element to generate electricity. A microstructure output is located on the other side of the second piezoelectric element relative to the mass to conduct electrical power generated by the second piezoelectric element.

In the first embodiment, the microstructure output is suitable for micro-discharge machining to output an output power of 1 to 8 watts (W), the current peak value is 14 to 130 milliamperes (mA), and the frequency of the oscillation is 1K. ~500KHz.

In the second embodiment, the microstructure output is adapted to electrically stimulate the ultrasonic wave to output an output power of 3 to 4 watts (W), and the current peak value is 30 to 100 milliamperes (mA), and the frequency of the oscillation It is 10~150KHz.

In a second embodiment, the composite piezoelectric system preferably includes a drive controller electrically coupled to the first piezoelectric element to cause the first piezoelectric element to generate a plurality of resonant frequencies. The resonant frequencies include 1 MHz, 1.26 MHz, and 1.5 MHz.

Referring first to FIG. 1, the composite piezoelectric system 1 of the present invention includes a first piezoelectric element 11, a mass 13, a second piezoelectric element 12, and a microstructure output end 17. The first piezoelectric element 11 is oscillated by being powered by a power source 100. That is, an electric field (voltage) is applied to the first piezoelectric element 11 by the inverse piezoelectric effect, and the electric dipole moment is elongated by the electric field, so that the first piezoelectric element 11 resists change and elongates along the electric field direction. Mechanical deformation to produce oscillations. Since the principle of oscillation of the piezoelectric element is known to those skilled in the art, it will not be repeated here.

A proof mass 13 is located between the first piezoelectric element 11 and the second piezoelectric element 12. The mass 13 conducts the oscillation of the first piezoelectric element 11 to the second piezoelectric element 12 to cause the second piezoelectric element 12 to generate electric power. That is, with the positive piezoelectric effect, when the physical pressure (displacement) generated by the oscillation is applied to the second piezoelectric element 12, the electric dipole moment of the second piezoelectric element 12 is shortened by compression, generated on the surface, etc. Positive and negative charges are used to maintain the original state and generate electricity.

The first piezoelectric element 11 generates a vibration X = A sin ωt , and the second piezoelectric element 12 generates a vibration X '= A 'sin( ω _n t - ), the relative displacement of the two D = A '- A . Its formula is:

Where K _S is a spring coefficient; C is a damping coefficient; m ₂ is the mass of the second piezoelectric element 12; It is the resonance frequency of the second piezoelectric element 12.

The second piezoelectric element 12 generates a positive piezoelectric effect due to relative displacement vibration, and the generated current and power are calculated as:

Where K _me is the mechanical coupling coefficient; V _bmf is the back electromotive force ( ); R _load load resistance; R _int is the impedance of the material.

The microstructure output end 17 is located on the other side of the second piezoelectric element 12 with respect to the mass 13 to conduct the power generated by the second piezoelectric element 12. The following is further described in two embodiments.

Referring to FIG. 2, in the first embodiment, the microstructure output terminal 17 is suitable for micro-discharge machining to output an output power of 1 to 8 watts (W), and the current peak value is 14 to 130 milliamperes (mA), and The oscillation frequency of the first piezoelectric element 11 is about 1 MHz.

The principle of micro-discharge machining is to use the metal conductor to conduct electricity. One pole is connected to the electrode tool (in this case, the microstructure output end 17), and the other pole is connected to the workpiece 90 to be processed. The working voltage is applied to the working fluid or the dielectric fluid 91 to produce a certain insulating effect. When the two electrodes are close to a small pitch (about 40 to 50 μm), the interelectrode is Due to the action of the electric field, the insulation of the dielectric liquid 91 is destroyed. Because the electrodes at both ends exceed the withstand voltage between the electrode and the workpiece, ionization can occur at both ends, and a discharge column is generated to generate a discharge. Behavior, and then by the thermal action (ionization, melting, evaporation) and mechanical effects (discharge, explosive force) caused by discharge, the metal is removed to achieve processing (for example The purpose of cutting).

Since the micro-discharge machining forms a discharge mark on the surface of the workpiece 90 during the discharge machining, the corroded workpiece 90 is cooled to a melt when it encounters the machining liquid 91, and is cooled by the machining liquid 91 to form a recast layer. In order to avoid this, the oscillation provided by the first piezoelectric element 11 generates numerous fine vacuum bubbles, which generate a strong impact force due to the acceleration when the pressure is broken during the oscillation (the partial pressure may even reach several thousand atmospheres). ), that is, a cavitation phenomenon is generated, whereby the adhesion of the surface of the workpiece 90 to the dead space of the slit can be eliminated. This vibration wave not only accelerates the speed of the chips, but also prevents the debris from adhering to the tool electrode, causing the secondary discharge to be abnormal or the abnormal wear of the tool. In addition, it is also possible to reduce the amount of the melt attached to the surface of the workpiece 90 to form a recast layer. With this processing method, the dimensional accuracy, shape accuracy and surface roughness of the hole are obviously superior, and the machineable hole diameter can reach φ10μm, depth 0.5~10mm, dimensional accuracy is ±0.005~±0.01mm, surface roughness (Ra) It is a micropore of 3.2 to 0.10 μm.

In the second embodiment, the microstructure output is adapted to electrically stimulate the ultrasonic wave to output an output power of 3 to 4 watts (W), and the current peak value is 30 to 100 milliamperes (mA), and the frequency of the oscillation It is 10~150KHz.

Referring to FIG. 3, the difference from FIG. 1 is that the composite piezoelectric system 1 of the second embodiment further includes a drive controller 26. The drive controller 26 is electrically coupled to the first piezoelectric element 21 to cause the first piezoelectric element 21 to generate a plurality of resonant frequencies. The resonant frequencies include 1 MHz, 1.26 MHz, and 1.5 MHz. Since a plurality of resonant frequencies generated by a drive controller (for example, a waveform generator and a regulator and an amplifier) are known, they are not described here.

Referring to FIG. 4, similarly to the first embodiment, the first piezoelectric element 21 of the second embodiment is oscillated by power supply 100 and generates a plurality of resonant frequencies by the drive controller 26. The ANSYS analysis can obtain three sets of resonance frequency points of 1MHz, 1.26MHz and 1.5MHz, and combine them with the technique of Frequency-Hopping Spread Spectrum (FHSS) to achieve the effect as shown in Fig. 5. Therefore, the sinusoidal waves of the three frequencies of 1MHz, 1.26MHz, and 1.5MHz are periodically frequency hopped by the microprocessor to control the frequency of the sine wave output to achieve the FM (Frequency Modulation) effect.

The second piezoelectric element 22 of the second embodiment is similar to the first embodiment and is used for discharging. As such, the second embodiment of the present invention may be an electrical stimulation ultrasound used for electrotherapy, not only by the first piezoelectric element 21, but also by the second piezoelectric element 22 to provide the electrical power required for the electrotherapy. Power is output through the microstructure output terminal 27.

Although the present invention has been clearly described by way of examples and description of the preferred embodiments, it should be understood that the present invention is not limited to the description. On the contrary, the present invention is intended to cover various modifications and similar arrangements and processes, and the scope of the appended claims should be interpreted in the broadest manner to cover all such modifications and similar arrangements and processes.

1, 2‧‧‧Composite piezoelectric system

11, 21‧‧‧ first piezoelectric element

13, 23‧‧ ‧ quality

12, 22‧‧‧second piezoelectric element

17, 27‧‧‧Microstructure output

100‧‧‧Power supply

90‧‧‧Workpieces

91‧‧‧Dielectric fluid

Figure 1 shows a block diagram of a composite piezoelectric system.

2 is a schematic view of a first embodiment of a composite piezoelectric system.

Figure 3 shows a block diagram of a preferred embodiment of a composite piezoelectric system.

4 is a schematic view of a second embodiment of a composite piezoelectric system.

Fig. 5 is a view showing the effect of combining the three sets of resonance frequency points using the technique of Frequency-Hopping Spread Spectrum (FHSS) in the second embodiment.

1‧‧‧Composite Piezoelectric System

11‧‧‧First Piezoelectric Element

13‧‧‧Quality

12‧‧‧second piezoelectric element

17‧‧‧Microstructure output

100‧‧‧Power supply

Claims (5)

A composite piezoelectric system comprising: a first piezoelectric element that is oscillated by a power supply; a proof mass located on one side of the first piezoelectric element; a second pressure An electrical component, the mass is located between the first piezoelectric component and the second piezoelectric component, and the oscillation of the first piezoelectric component is conducted to the second piezoelectric component by the mass to enable the first The two piezoelectric elements generate electrical power; and a microstructured output end located on the other side of the second piezoelectric element to conduct electrical power generated by the second piezoelectric element. The composite piezoelectric system according to claim 1, wherein the microstructure output end is suitable for micro-discharge machining to output an output power of 1 to 8 watts (W), and the current peak value is 14 to 130 milliamperes. (mA), and the frequency of the oscillation is 1 to 500 KHz. The composite piezoelectric system according to claim 1, wherein the microstructure output end is suitable for electrical stimulation of ultrasonic waves to output an output power of 3 to 4 watts (W), and the current peak value is 30 to 100 millimeters. Ampere (mA), and the frequency of this oscillation is 10~150KHz. The composite piezoelectric system of claim 3, further comprising a drive controller electrically coupled to the first piezoelectric element to cause the first piezoelectric element to generate a plurality of resonant frequencies. The composite piezoelectric system of claim 4, wherein the resonant frequencies comprise 1 MHz, 1.26 MHz, and 1.5 MHz.