A piezoelectric vibration energy harvesting device of a z-beam structure

Abstract

The application provides a piezoelectric vibration energy collection device with a Z-shaped beam structure, which comprises a piezoelectric energy collection circuit composed of multiple straight beams and piezoelectric layers, and the multiple straight beams in the piezoelectric energy collection circuit are connected in a head-to-tail mode through a wheel disc corner structure, wherein one end of the first straight beam is a fixed end, and the tail end of the last straight beam is a free end. The technical problem of single energy collection frequency band and direction in the prior art is solved. When one end of the Z-shaped beam structure is excited by a vibration source, the straight beams are bent and deformed, the piezoelectric layers are bent and deformed, and thus vibration energy is converted into electric energy. The structure of the application is composed of multiple beams and multiple piezoelectric layers, so that the modal frequency of resonance is concentrated, energy collection under multiple resonance frequencies is realized, and the energy collection efficiency is effectively improved.

Description

Technical Field

[0001] This invention relates to the field of energy technology, and in particular to a piezoelectric vibration energy harvesting device with a Z-shaped beam structure. Background Technology

[0002] In recent years, with the dwindling resources of oil and coal, human demand for energy has been increasing, making energy a critical issue that urgently needs to be addressed. Harvesting energy from environmental vibrations is currently a hot research topic both domestically and internationally. Vibration-based energy harvesters convert the mechanical energy prevalent in the environment into electrical energy, enabling self-powered sensing, control, and actuation. They offer advantages such as flexibility, energy saving, environmental friendliness, and sustainability, and have broad application prospects in aerospace, biomedicine, industrial production, traffic management, environmental monitoring, and military reconnaissance. Piezoelectric energy harvesters, due to their high power density and flexible design, have become one of the important methods for harvesting vibration energy.

[0003] Existing piezoelectric vibration energy harvesters generally only achieve high energy harvesting efficiency near the structural resonant frequency and operate at a single frequency. Therefore, they cannot be applied to energy harvesting in complex engineering environments. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a piezoelectric vibration energy harvesting device with a Z-shaped beam structure to achieve low-bandwidth energy harvesting at multiple resonant frequencies and improve the efficiency of energy harvesting.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows:

[0006] A piezoelectric vibration energy harvesting device with a Z-shaped beam structure includes a piezoelectric energy harvesting circuit composed of multiple straight beams and piezoelectric layers. The multiple straight beams in the piezoelectric energy harvesting circuit are connected end to end by a wheel rotation structure. One end of the first straight beam is a fixed end, and the tail end of the last straight beam is a free end. When the fixed end of the first straight beam is subjected to external excitation vibration, the vibration is transmitted to the other multiple straight beams. The piezoelectric layer crystals fixed on the straight beams will deform, thereby generating electrical energy.

[0007] The multi-segment straight beam includes a first straight beam, a second straight beam, and a third straight beam. The starting end of the first straight beam is fixed and constrained, and the end of the first straight beam has two cylindrical through-hole rings with the same diameter as the pins. The middle of the starting end of the second straight beam has a cylindrical through-hole ring, which is connected to the two cylindrical through-hole rings at the end of the first straight beam and fixed with a pin. The end of the second straight beam has two cylindrical through-hole rings identical to those at the end of the first straight beam. The middle of the starting end of the third straight beam has a cylindrical through-hole ring, which is connected to the two cylindrical through-hole rings at the end of the second straight beam and fixed with a pin. The end of the third straight beam is a free end.

[0008] The piezoelectric layer includes a first piezoelectric layer, a second piezoelectric layer, and a third piezoelectric layer; the first piezoelectric layer is laid flat on the upper and lower surfaces of the first straight beam, the second piezoelectric layer is laid flat on the upper and lower surfaces of the second straight beam, and the third piezoelectric layer is laid flat on the upper and lower surfaces of the third straight beam.

[0009] The aforementioned wheel-shaped corner structure includes pins, nuts, and a disc. The disc is fixed to the outside of two cylindrical through holes at the ends of the straight beam. Through holes are evenly distributed around the disc. Nuts are fixed to the discs at both ends through these through holes. The cylindrical through-hole rings at the beginning and end of the two straight beams are joined together and secured with pins. The spacing of the through holes around the disc is adjusted according to actual conditions to achieve angle adjustment between the straight beams.

[0010] The multi-segment straight beam is made of aluminum alloy, the piezoelectric layer is made of PZT series piezoelectric ceramic, and the pins and nuts are made of carbon steel series.

[0011] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0012] This invention proposes a piezoelectric vibration energy harvesting device with a Z-shaped beam structure, which has the characteristic of energy harvesting at multiple resonant mode frequencies, thereby improving the bandwidth of energy harvesting.

[0013] The structure proposed in this invention is a cantilever piezoelectric energy harvester, which has the characteristics of high energy harvesting efficiency and simplicity.

[0014] The structure proposed in this invention can be adjusted by a wheel to change the resonant frequency of the structure itself, thus adapting to the energy harvesting characteristics under different working conditions.

[0015] The structure proposed in this invention is a Z-shaped beam structure, which has good energy harvesting performance for transverse vibration excitation, longitudinal vibration excitation, and in-plane excitation at different angles, and is suitable for vibration energy harvesting in complex engineering environments. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of a specific embodiment of the present invention.

[0017] Figure 2 This is a schematic diagram of the first, second, and third straight beam structures of the present invention.

[0018] Figure 3 This is a schematic diagram of the disc pin structure of the present invention.

[0019] Figure 4 This is a schematic diagram of the energy harvesting circuit of the present invention.

[0020] Figure 5 This is a simulation diagram of the energy harvesting voltage results of the present invention. Detailed Implementation

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings required in the embodiments will be briefly described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0022] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] See Figure 1 A piezoelectric vibration energy harvesting device with a Z-shaped beam structure includes a piezoelectric energy harvesting circuit consisting of three straight beams and a piezoelectric layer. The three straight beams in the piezoelectric energy harvesting circuit are connected end to end by a wheel rotation structure. One end of the first straight beam is a fixed end, and the tail end of the third straight beam is a free end. When the fixed end of the first straight beam is subjected to external excitation vibration, the vibration is transmitted to the other straight beams. The piezoelectric layer crystals fixed on the straight beams will deform, thereby generating electrical energy.

[0024] like Figure 2 As shown, the multi-segment straight beam includes a first straight beam 1, a second straight beam 2, and a third straight beam 3. The starting end 13 of the first straight beam 1 is fixed and constrained. The end of the first straight beam 1 has two cylindrical through-hole rings with the same diameter as the pin 4. The middle of the starting end of the second straight beam 2 has a cylindrical through-hole ring, which is connected to the two cylindrical through-hole rings at the end of the first straight beam 1 and fixed with the pin 4. The end of the second straight beam 2 has two cylindrical through-hole rings identical to those at the end of the first straight beam 1. The middle of the starting end of the third straight beam 3 has a cylindrical through-hole ring, which is connected to the two cylindrical through-hole rings at the end of the second straight beam 2 and fixed with the pin 4. The end of the third straight beam 3 is a free end.

[0025] The piezoelectric layer includes a first piezoelectric layer 10, a second piezoelectric layer 11, and a third piezoelectric layer 12; the first piezoelectric layer 10 is laid flat on the upper and lower surfaces of the first straight beam 1, the second piezoelectric layer 11 is laid flat on the upper and lower surfaces of the second straight beam 2, and the third piezoelectric layer 12 is laid flat on the upper and lower surfaces of the third straight beam 3.

[0026] like Figure 3 As shown, the wheel rotation structure includes pins 4, nuts 5, and discs 6. The discs 6 are fixed to the outside of two cylindrical through holes at the ends of the straight beams. Through holes 7 are evenly distributed around the discs 6. Nuts 5 are fixed to the discs 6 at both ends through the through holes 7. The cylindrical through holes at the beginning and end of the two straight beams are joined together and fixed with pins 4. The spacing of the through holes 7 around the wheel 6 is adjusted according to actual conditions to achieve angle adjustment between the straight beams. The multi-segment straight beams are made of aluminum alloy, the piezoelectric layer is PZT series piezoelectric ceramic, and the pins and nuts are made of carbon steel.

[0027] Alternatively, the circuit of the three piezoelectric beams in this embodiment can be referenced. Figure 4 The piezoelectric layers of the first, second, and third straight beams are led out with wires and connected in parallel to the load. The Z-beam is led out with a wire, grounded, and connected to the load. This achieves the parallel output of piezoelectric energy from the three beams. Different circuits can be connected depending on other situations; this embodiment only provides one feasible and effective circuit.

[0028] In this implementation, each piezoelectric layer is connected to the surface of the corresponding straight beam structure, but not to any other parts of the structure.

[0029] The Z-shaped piezoelectric vibration energy harvesting device in this embodiment is an integrated system combining three beams. Through the connection of the three beams and the variable structure of the wheel and pin, efficient vibration energy harvesting is achieved. When the excitation frequency of the external environment changes, the position of the wheel and nut is adjusted to change the structure's inherent frequency, adapting to the external excitation and thus achieving energy harvesting from low to high frequencies. As the angle changes, the vibration frequency of the energy harvesting will shift; certain parameters are taken, and the results are referenced... Figure 5 This enables energy harvesting at multiple resonant frequencies.

[0030] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A piezoelectric vibration energy harvesting device with a Z-shaped beam structure, characterized in that, include: A piezoelectric energy harvesting circuit consisting of multiple straight beams and piezoelectric layers, and a variable wheel rotation structure. The multiple straight beams in the piezoelectric energy harvesting circuit are connected end to end by the wheel rotation structure. One end of the first straight beam is a fixed end, and the tail end of the last straight beam is a free end. When the fixed end of the first straight beam is subjected to external excitation vibration, the vibration is transmitted to the other multiple straight beams. The piezoelectric layer crystals fixed on the straight beams will deform, thereby generating electrical energy.

2. The piezoelectric vibration energy harvesting device for the Z-shaped beam structure according to claim 1, characterized in that, The multi-segment straight beam includes a first straight beam (1), a second straight beam (2), and a third straight beam (3), with the starting end (13) of the first straight beam (1) being a fixed constraint; The piezoelectric energy harvesting circuit includes a first straight beam structure with through holes at the end and a second straight beam structure at the beginning, which are connected by pins, and the connection structure is a wheel rotation structure; the second straight beam structure with through holes at the end and a third straight beam structure at the beginning, which are connected by pins, and the connection structure is a wheel rotation structure.

3. The piezoelectric vibration energy harvesting device for the Z-shaped beam structure according to claim 1, characterized in that, The aforementioned wheel rotation structure includes a pin (4), a nut (5), and a disc (6); when the excitation frequency of the external environment changes, the structure's inherent frequency is changed by adjusting the position of the disc and the nut to adapt to the external environment excitation, thereby realizing energy harvesting from low frequency to high frequency.

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