CN112737411A - Piezoelectric power generation device - Google Patents

Abstract

The invention discloses a piezoelectric generating device, comprising an outer ring, an inner ring and a piezoelectric generating group. At least two groups of magnets are uniformly arranged on the inner surface of the side wall of the outer ring along the circumferential direction, and at least two groups of magnets are uniformly arranged on the surface of the inner column along the circumferential direction; A transparent rocker movable groove; the inner ring is provided with a rocker, and the rocker extends from the inner ring through the rocker movable groove to extend out of the outer ring; the inner ring is provided with at least two A piezoelectric generating group, the piezoelectric generating group includes a piezoelectric component, the piezoelectric component is fixedly connected to the inner ring, one end of the piezoelectric component faces the inner surface of the side wall of the outer ring, and the other end faces the inner surface of the side wall of the outer ring. towards the inner column. The external environment transmits the low-frequency vibration to the piezoelectric generator through the rocker. The piezoelectric generator uses the cooperation of multiple groups of piezoelectric components on the inner ring and multiple groups of magnets on the outer ring to realize high-frequency vibration power generation of the piezoelectric components to generate electricity. Improve power generation efficiency.

Description

A piezoelectric generator

technical field

The invention belongs to the field of power generation devices, and in particular relates to a piezoelectric power generation device.

Background technique

In order to realize the self-power supply of wireless sensors used for marine environmental monitoring, many scholars at home and abroad have proposed methods to convert wave energy into electrical energy by using the law of electromagnetic induction, piezoelectric effect and triboelectric effect, so as to supply power to wireless sensors, and have designed many methods. A variety of small power generation devices. Most of these devices use resonant mechanical structures. Taking electromagnetic power generation devices as an example, the magnets vibrate back and forth under the drive of waves, cutting the magnetic field lines to generate induced electromotive force in the coil. This kind of resonant power generation device reaches the maximum output power when the external excitation frequency is equal to its own natural frequency.

Although the existing resonant power generating device can generate larger output power when the external excitation frequency is equal to its own natural frequency, that is, when the resonance state is reached. However, its working frequency range is very narrow, and only within a narrow frequency range near the natural frequency, this resonant power generation device can work normally. For most power generation devices based on environmental vibration, their natural frequency is far greater than the frequency of environmental vibration. According to the theoretical formula, the output power of the generator is proportional to the cube of its operating frequency. This means that when the excitation frequency of the external environment decreases, the output power of the generator will drop sharply. In order to make the output power as large as possible, the natural frequency of the power generator must be close to the ambient vibration frequency. Environmental vibration is low-frequency vibration, the frequency range is generally 1-20Hz, and the frequency of waves is less than 5Hz. If the natural frequency of the power generation device is to be near it, the overall size of the power generation device must be increased, because generally speaking, the power generation device The natural frequency of is inversely proportional to its overall size. However, the increase in the volume of the power generation device will greatly reduce its output power density (ratio of output power to its working volume), and will also bring about a series of problems such as increased manufacturing cost and increased installation difficulty.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a piezoelectric power generation device. The external environment (such as waves) transmits low-frequency vibration to the piezoelectric power generation device through a rocker, and the piezoelectric power generation device uses multiple sets of piezoelectric components on the inner ring and The cooperation of multiple sets of magnets on the outer ring realizes high-frequency vibration power generation of piezoelectric components to improve power generation efficiency.

In order to solve the above-mentioned technical problems, the present invention adopts the following technical scheme:

A piezoelectric generating device, comprising an outer ring, an inner ring and a piezoelectric generating group; wherein,

The outer ring is a cylindrical structure with one end open, and the bottom inner wall of the outer ring is provided with a rotating groove and an inner column arranged at the center of the bottom inner wall; the inner surface of the side wall of the outer ring is along the circumferential direction. At least two sets of magnets are evenly arranged, and at least two sets of magnets are evenly arranged on the surface of the inner column along the circumferential direction; the side wall of the outer ring is arranged with a transparent rocker movable groove along the circumferential direction;

The inner ring is provided with a rocker, and the rocker extends from the inner ring to the outer ring through the rocker movable groove; the edge of the inner ring is provided with a rectangular convex edge, and the rectangular convex edge Matching with the rotation groove of the outer ring to enable the outer ring and the inner ring to rotate relative to each other;

The inner ring is provided with at least two groups of piezoelectric generating groups along the circumferential direction, the piezoelectric generating groups include piezoelectric components, the piezoelectric components are fixedly connected to the inner ring, and one end of the piezoelectric components faces the outer The inner surface of the outer wall of the ring, and the other end faces the inner column.

In a specific embodiment, the piezoelectric component includes a cantilever beam, a piezoelectric sheet, and two magnets, the piezoelectric sheet is attached to the cantilever beam, and the two magnets are respectively fixed at two ends of the cantilever beam.

In a specific embodiment, the inner ring is provided with a rectangular groove, and the middle position of the cantilever beam of the piezoelectric component is fixedly connected to the rectangular groove of the inner ring.

In a specific embodiment, the number of piezoelectric sheets of the piezoelectric component is four, and the four piezoelectric sheets are symmetrically attached to the upper and lower surfaces of the cantilever beam along the middle position of the cantilever beam.

In a specific embodiment, the opposite ends of the magnets of the piezoelectric component and the magnets of the outer ring have the same polarity.

In a specific embodiment, each group of the piezoelectric generating groups includes three piezoelectric components, and the three piezoelectric components are arranged along the radial direction of the inner ring.

In a specific embodiment, each group of magnets on the outer ring located at the movable slot of the rocker includes two magnets, and each other group of magnets includes three magnets.

In a specific embodiment, the circumferential angle of the rocker movable groove is 90 degrees.

In a specific embodiment, there are three sets of magnets on the inner surface of the side wall of the outer ring, and three sets of magnets on the surface of the inner column.

Adopting the present invention has the following beneficial effects:

1. Use the float and the rocker to convert the up and down motion of the wave into the rotational motion of the inner ring (rotor).

2. Cantilever beams and piezoelectric sheets are arranged on the inner and outer sides of the inner ring (rotor) to improve the output power density.

3. The cooperation of the multiple groups of piezoelectric components on the inner ring and the multiple groups of magnets on the outer ring constitutes an up-frequency mechanism, which uses the interaction force between the magnets to drive the cantilever beam to oscillate freely, and then uses the higher frequency vibration of the cantilever beam to conduct vibration. generate electricity.

4. Piezoelectric sheets are arranged on the upper and lower surfaces of the cantilever beam, and the deformation of the cantilever beam is fully utilized to generate electricity according to the piezoelectric effect.

Description of drawings

Figure 1 is a schematic diagram of a piezoelectric power generation system;

Figure 2 is a schematic diagram of a piezoelectric generator;

Figure 3 is an exploded view of the piezoelectric generator;

Figure 4 is a structural diagram and an exploded diagram of a piezoelectric assembly;

Fig. 5 is the working principle diagram of the piezoelectric generator;

FIG. 6 is a working principle diagram of the piezoelectric assembly.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

1 to 6 , the present invention discloses a piezoelectric power generation device, which can be used for a power generation system (ie, a piezoelectric power generation system) that captures wave energy, and the power generation system includes a float 1, a piezoelectric power generation system The device 30 , the column and the base 4 , the float 1 is connected to the piezoelectric generating device 30 through the rocker 2 , and the piezoelectric generating device 30 is fixed to the base 4 through the column.

The piezoelectric generating device 30 includes an outer ring 3, an inner ring 4 and a piezoelectric generating group 6. The outer ring 3 is provided with a rectangular rocker movable slot 31 with a central angle of 90 degrees along the circumferential direction. The rocker 2 can move along the rocker. The movable groove 31 swings up and down, and the rocker 2 extends through the outer ring 3 to the inner ring 4 and is fixedly connected therewith. When the rocker 2 swings up and down, the inner ring 4 and the outer ring 3 will rotate relative to each other.

The inner wall of the bottom of the outer ring 3 is provided with a rotating groove 32, and the rotating groove 32 cooperates with several saw-shaped convex edges 41 arranged on the edge of the inner ring 4 to form a rotating pair, so that the outer ring 3 and the inner ring 4 can be rotated. relative rotation. An inner column 5 is arranged in the center of the inner wall of the bottom of the outer ring 3 , and the inner column 5 is fixedly connected with the inner wall of the bottom of the outer ring 3 .

The outer ring 3 is cylindrical, and magnet groups are embedded on the inner surface of the side wall of the outer ring 3 and the surface of the inner column 5 . In a specific embodiment, the inner surface of the side wall of the outer ring 3 is evenly distributed with 12 sets of magnet groups along the circumferential direction at a central angle of 30 degrees. Each of the other sets of magnets is provided with three magnets. On the surface of the inner column 5, 6 groups of magnet groups are evenly distributed along the circumferential direction with a central angle of 60 degrees, and each group of magnet groups has 3 magnets.

The inner ring 4 has a thin-walled cylindrical shape, and 6 groups of rectangular grooves 7 are opened evenly along the circumferential direction of the inner ring 4 (at an interval of 60 degrees from the central angle), and each group has 3 rectangular grooves 7 arranged along the radial direction of the inner ring 4. Correspondingly, , three piezoelectric components 8 arranged radially constitute a piezoelectric generator group 6 . A piezoelectric component 8 forms a fixed fit with the inner ring 4 through the rectangular groove 7 , that is, the middle part of the power generating component 8 forms an interference fit with the rectangular groove 7 . The piezoelectric components 8 are in one-to-one correspondence with the rectangular grooves 7 , and there are 6 groups of 18 piezoelectric components 8 installed on the inner ring 4 .

The piezoelectric assembly 8 includes a cantilever beam 81 (a brass sheet can be used), four piezoelectric sheets 82 and two magnets 83 . The cantilever beam 81 is a brass sheet with a thickness of 0.4 mm. The middle of the cantilever beam 81 is fixedly connected to the rectangular groove 7 of the inner ring 4. A magnet 83 is installed on the two free ends of the cantilever beam 81. Four piezoelectric sheets 82 are symmetrically pasted on the upper and lower surfaces along the middle position.

The operation principle of the piezoelectric power generation system according to the present invention is as follows. When the float 1 vibrates up and down with the waves, it will swing up and down with the rocker 2, thereby causing the inner ring 4 and the outer ring 3 to rotate relative to each other. There is a small gap between the piezoelectric generating group 6 installed on the inner ring 4 and the inner surface of the side wall of the outer ring 3 and the piezoelectric generating group 6 and the surface of the inner column 5 . When the inner ring 4 and the outer ring 3 rotate relative to each other, the magnets 83 at both ends of the cantilever beam 81 interact with the magnets on the inner surface of the side wall of the outer ring 3 and the magnets on the inner column 5 respectively. Under the action of the magnetic force, the cantilever beam 81 is deformed, so that the piezoelectric sheet 82 attached to the surface of the cantilever beam 81 is also deformed. According to the positive piezoelectric effect, the compressed (or pulled) piezoelectric sheet will output electrical energy.

The specific vibration power generation process of the piezoelectric component 8 is as follows. When the inner ring 4 and the outer ring 3 rotate relative to each other, the magnet 33 on the outer ring 3 vibrates up and down relative to the magnet 83 of the piezoelectric component 8 . When the magnet 33 on the outer ring 3 is close to the magnet 83 on the cantilever beam 81 , an interaction force is generated between the magnets, and this force drives the cantilever beam 81 to bend. When the magnet 83 continues the relative movement and gradually moves away from the cantilever beam, the acting force is weakened, and the cantilever beam 81 is released. After being released, the cantilever beam 81 is free to vibrate at its natural frequency. The swing frequency of the rocker 2 is equal to the frequency of the wave motion, which is usually very low (<5Hz), but during the swing of the rocker 2, after the cantilever beam 81 is toggled by the magnet 33 on the outer ring 3 each time, They will vibrate freely at their natural frequency, which is much higher than the frequency of waves and can reach hundreds of hertz. This achieves an increase in frequency, and ultimately an increase in the output power and energy conversion efficiency of the piezoelectric generator.

The piezoelectric power generation system of the present invention can efficiently realize the conversion of wave energy to electric energy, can replace the battery of the wireless sensor used for marine environment monitoring, avoid the trouble of battery replacement and recharging, and is conducive to the establishment of the marine Internet of Things. Great help.

The piezoelectric power generation system for capturing wave energy according to the present invention can be understood as two vibration systems connected in series, one is a low frequency vibration system (float end), the other is a high frequency vibration system (piezoelectric generator end) . The low-frequency vibration system can transmit the low-frequency environmental (wave) vibration to the high-frequency vibration system, and the high-frequency vibration system uses the electromechanical conversion mechanism to convert the vibration energy into electrical energy. The introduction of this up-frequency structure brings two basic advantages: one is that the vibration frequency used for power generation has been greatly increased, which directly leads to an increase in the output power density; the other is that the overall size of the power generation device is not increased. It can also make its natural frequency close to the ambient vibration frequency.

In addition, the electromechanical conversion mechanism used in the present invention is the piezoelectric effect (when the piezoelectric sheet is deformed, a polarization phenomenon will occur inside, thereby generating an electromotive force). Compared with the traditional electromagnetic power generation device, this piezoelectric power generation device can Make full use of the characteristics of low frequency and large amplitude of wave energy and complete the conversion of electric energy more efficiently. Because according to Faraday's law of electromagnetic induction, the output power of the electromagnetic generator is proportional to the rate of change of the magnetic field lines inside the coil, that is, proportional to the moving speed of the magnet, so the frequency of the wave has a great influence on it, while the amplitude of the wave has little influence on it. , which cannot take advantage of the large amplitude of the wave. The present invention is a piezoelectric generator, and the large amplitude of the waves will directly lead to an increase in the number of vibrations of the piezoelectric sheet, so the frequency and amplitude of the waves both affect the power output of the generator.

Aiming at the problem of difficulty in generating low-frequency and large-amplitude wave energy, the invention combines the frequency-up mechanism with the electromechanical conversion mechanism based on piezoelectric effect, thereby improving the conversion efficiency of electric energy and the output power density. The invention has great application potential in realizing self-power supply for marine electronic devices such as wireless sensors used for marine environment monitoring.

It should be understood that the exemplary embodiments described herein are illustrative and not restrictive. Although one or more embodiments of the invention have been described in conjunction with the accompanying drawings, those of ordinary skill in the art will appreciate that various changes can be made without departing from the spirit and scope of the invention as defined by the appended claims. Changes in form and detail.

Claims (9)

1. A piezoelectric generating device, characterized in that, the piezoelectric generating device comprises an outer ring, an inner ring and a piezoelectric generating group; wherein, The outer ring is a cylindrical structure with one end open, and the bottom inner wall of the outer ring is provided with a rotating groove and an inner column arranged at the center of the bottom inner wall; the inner surface of the side wall of the outer ring is along the circumferential direction. At least two sets of magnets are evenly arranged, and at least two sets of magnets are evenly arranged on the surface of the inner column along the circumferential direction; the side wall of the outer ring is arranged with a transparent rocker movable groove along the circumferential direction; The inner ring is provided with a rocker, and the rocker extends from the inner ring to the outer ring through the rocker movable groove; the edge of the inner ring is provided with a rectangular convex edge, and the rectangular convex edge Matching with the rotation groove of the outer ring to enable the outer ring and the inner ring to rotate relative to each other; The inner ring is provided with at least two groups of piezoelectric generating groups along the circumferential direction, the piezoelectric generating groups include piezoelectric components, the piezoelectric components are fixedly connected to the inner ring, and one end of the piezoelectric components faces the outer The inner surface of the outer wall of the ring, and the other end faces the inner column. 2. The piezoelectric power generation device according to claim 1, wherein the piezoelectric component comprises a cantilever beam, a piezoelectric sheet and two magnets, the piezoelectric sheet is attached to the cantilever beam, and the two Magnets are respectively fixed on both ends of the cantilever beam. 3 . The piezoelectric generator according to claim 2 , wherein a rectangular groove is provided on the inner ring, and the middle position of the cantilever beam of the piezoelectric component is fixedly connected to the rectangular groove of the inner ring. 4 . 4 . The piezoelectric generator according to claim 3 , wherein the number of piezoelectric sheets of the piezoelectric component is four, and the four piezoelectric sheets are symmetrically attached along the middle position of the cantilever beam. 5 . Attached to the upper and lower surfaces of the cantilever beam. 5 . The piezoelectric generator according to claim 4 , wherein the magnets of the piezoelectric element and the end faces of the magnets of the outer ring facing each other have the same polarity. 6 . 6 . The piezoelectric generating device according to claim 1 , wherein each group of the piezoelectric generating groups comprises three piezoelectric components, and the three piezoelectric components are along the radial direction of the inner ring. 7 . set up. 7 . The piezoelectric generating device according to claim 6 , wherein each group of magnets on the outer ring located at the movable groove of the rocker comprises two magnets, and each other group of magnets comprises three magnets. 8 . 8 . The piezoelectric generator according to claim 1 , wherein the circumferential angle of the rocker movable groove is 90 degrees. 9 . 9 . The piezoelectric generating device according to claim 1 , wherein there are three groups of magnets on the inner surface of the side wall of the outer ring, and three groups of magnets on the surface of the inner column. 10 .

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