Piezoelectric-electromagnetic coupling vibration energy collection device with continuously adjustable resonant frequency

Abstract

The invention relates to a piezoelectric-electromagnetic coupling vibration energy collecting device with continuously adjustable resonant frequency. The piezoelectric-electromagnetic coupling vibration energy collecting device comprises an energy collecting support, a piezoelectric cantilever beam, an electromagnetic coil and a bending piezoelectric transducer. The magnetic distance is changed by adjusting the nuts of the upper and lower supports, the nonlinear magnetic force is changed, the resonant frequency of the vibration energy collecting device can be continuously adjusted, and the vibration energy of the piezoelectric cantilever beam, the electromagnetic coil and the bending piezoelectric transducer can be synchronously collected. The device receives external excitation, vibration is transmitted to a piezoelectric cantilever beam clamped by a clamping piece through a bolt, and piezoelectric ceramic vibration energy at the root of the cantilever beam is collected; magnets at the tail ends of the piezoelectric cantilever beams move up and down to change the magnetic flux in the coils and generate induction current, so that partial vibration energy collection of the electromagnetic coils is realized; the magnetic repulsive force between the magnet and the magnet on the top of the bending transducer presses piezoelectric ceramics in the bending transducer, and partial vibration energy collection of the bending piezoelectric transducer is completed.

Description

Technical Field

[0001] The invention belongs to the field of vibration energy collection, and relates to a piezoelectric-electromagnetic coupling vibration energy collection device with continuously adjustable resonant frequency. Background Art

[0002] Currently, there are three main methods of vibration energy recovery: electrostatic, electromagnetic, and piezoelectric.

[0003] At present, most designs of vibration energy harvesting devices at home and abroad collect vibration energy at a single frequency, ignoring the complex frequency components in the actual working environment, resulting in low vibration energy collection efficiency and low energy utilization.

[0004] Piezoelectric-electromagnetic coupling vibration energy harvesting devices can improve the collection efficiency of vibration energy and improve energy utilization. However, the structure of most piezoelectric-electromagnetic coupling vibration energy harvesting devices cannot be changed at any time, and the resonant frequency cannot be adjusted, which is not suitable for complex and changeable working conditions. Summary of the invention

[0005] The present invention aims at the main existing problems of vibration energy collection devices: (1) mainly collecting vibration energy at a single frequency; (2) the resonant frequency cannot be adjusted; (3) the piezoelectric-electromagnetic coupling vibration energy collection device does not fully utilize the repulsive force between magnets, introduces nonlinear magnetic force, broadens the frequency band range of vibration energy collection, and realizes wide-band energy collection; the adjusting nut changes the position of the upper and lower brackets, changes the position of the magnet on the top of the curved piezoelectric transducer, changes the magnetic force between the magnets, and adjusts the resonant frequency of the vibration of the entire device. The present invention sets up a curved piezoelectric transducer, combines electromagnetic and piezoelectric power generation methods, and develops a piezoelectric-electromagnetic coupling vibration energy collection device with continuously adjustable resonant frequency, realizes the synchronous collection of vibration energy of the three parts of the piezoelectric cantilever beam, electromagnetic coil, and curved piezoelectric transducer, improves the magnetic force utilization rate of the current piezoelectric-electromagnetic coupling energy collection device, and adapts to complex and changeable actual working conditions.

[0006] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0007] A piezoelectric-electromagnetic coupling vibration energy collection device with continuously adjustable resonant frequency, characterized by comprising: an energy collection bracket (1), a piezoelectric cantilever beam (2), an electromagnetic coil (3), and a bending piezoelectric transducer (4).

[0008] The energy collection bracket (1) comprises an upper bracket (11), bolts (12), nuts (13), and a lower bracket (14); a circular through hole with a diameter of 5 to 10 mm is opened at the center of the lower bracket (14); the energy collection bracket (1) is fixed to the external excitation device via the bolts (12); and the upper bracket (11) and the lower bracket (14) are connected and fixed via the bolts (12) and nuts (13).

[0009] The piezoelectric cantilever beam (2) comprises an aluminum substrate (15) and a piezoelectric ceramic (16). The piezoelectric cantilever beam (2) is clamped and fixed by an aluminum clamp (17). The length of the aluminum clamping platform (17) clamping the aluminum substrate (15) is 20 to 30 mm.

[0010] The electromagnetic coil (3) comprises a coil frame (19), a coil (20), and a coil placement platform (21); the coil placement platform (21) is adhered to the inner surfaces of the upper bracket (11) and the lower bracket (14) by epoxy resin glue; the coil (20) is wound on the coil frame (19), and the coil frame (19) is adhered to the surface of the coil placement platform (21) by epoxy resin glue.

[0011] The bending piezoelectric transducer (4) comprises a bending clip (24), a bending piezoelectric transducer magnet (22), and a piezoelectric ceramic (23). The piezoelectric ceramic (23) is clamped in the middle of the bending clip (24). The bottom of the bending clip (24) made of 65Mn is adhered to the surface of the upper bracket (11) and the lower bracket (14) by epoxy resin glue. The upper and lower parts of the bending piezoelectric transducer (4) are symmetrical.

[0012] Preferably, the bolts (12) pass through round through holes with a diameter of 5 to 10 mm on both sides of the aluminum clamping platform (17), and the piezoelectric cantilever beam (2) is clamped and fixed by nuts (13).

[0013] Preferably, the piezoelectric ceramic (16) is glued to the root of the aluminum substrate (15) with epoxy resin glue, and the piezoelectric cantilever beam magnet (18) is glued to the end of the piezoelectric cantilever beam (2) with epoxy resin glue, and the end piezoelectric cantilever beam magnet (18) is symmetrical up and down.

[0014] Preferably, a circular hole is provided at the center of the coil placement platform (21), the curved piezoelectric transducer magnet (22) passes through the circular hole of the coil placement platform (21), the curved piezoelectric transducer magnet (22) is placed inside the coil frame (19), the coil frame (19) and the curved piezoelectric transducer magnet (22) are coaxial, and the electromagnetic coil (3) is symmetrical up and down.

[0015] Preferably, the angle between the bent clip (24) and the piezoelectric ceramic (23) ranges from 15 to 25 degrees.

[0016] Preferably, the diameter of the curved piezoelectric transducer magnet (22) is equal to the width of the piezoelectric ceramic (23) and the curved clip (24), and the curved piezoelectric transducer magnet (22) is coaxial with the piezoelectric cantilever beam magnet (18).

[0017] The piezoelectric-electromagnetic coupling vibration energy collection device with continuously adjustable resonant frequency can synchronously collect vibration energy from three parts: a piezoelectric cantilever beam (2), an electromagnetic coil (3), and a bending piezoelectric transducer (4).

[0018] Preferably, the magnetic moment between the piezoelectric cantilever beam magnet (18) and the bending piezoelectric transducer magnet (22) is continuously adjusted by the upper bracket (11), the lower bracket (14) and the nut (12).

[0019] Preferably, the piezoelectric cantilever beam (2) receives vibration via an aluminum clamping platform (17), and the magnet (18) at the end of the piezoelectric cantilever beam synchronously drives the electromagnetic coil (3) and the bending piezoelectric transducer (4) to collect vibration energy.

[0020] Preferably, the magnet (18) at the end of the piezoelectric cantilever beam, the electromagnetic coil (3), and the bending piezoelectric transducer (4) are at the same vertical position.

[0021] The working principle of the present invention is as follows: the position of the bracket is changed by adjusting the nut 13, thereby changing the magnetic moment, and realizing the continuous adjustment of the resonant frequency of the vibration energy collection device. The lower bracket 14 receives external excitation, and the vibration is transmitted to the aluminum clamping platform 17 through the bolt 12. The vibration on the aluminum clamping platform 17 is transmitted to the piezoelectric cantilever beam 2, so that the piezoelectric cantilever beam 2 oscillates up and down, and the piezoelectric ceramic 16 at the root of the cantilever beam is subjected to extrusion force and shear force. Due to the positive piezoelectric effect, the internal charge of the piezoelectric ceramic sheet 16 moves, so that a voltage is generated at both ends of the external load of the piezoelectric ceramic 16. While the piezoelectric cantilever beam 2 oscillates up and down, the end piezoelectric cantilever beam magnet 18 moves up and down, causing the internal magnetic flux of the upper and lower coils 20 to change, and an induced current is generated in the coil 20; the bent piezoelectric transducer magnet 22 at the top of the bent piezoelectric transducer 4 is subjected to the magnetic force of the piezoelectric cantilever beam magnet 18, which compresses the piezoelectric ceramic 23 in the bent piezoelectric transducer 4 to generate charge movement, so that a voltage is generated at both ends of the external load of the piezoelectric ceramic 23.

[0022] The beneficial effects of the present invention are concentrated in the following aspects:

[0023] 1. The present invention changes the magnetic moment between the piezoelectric cantilever beam magnet and the bending piezoelectric transducer magnet by adjusting the nuts of the upper and lower brackets, thereby changing the nonlinear magnetic force, and can realize continuous adjustment of the resonant frequency of the piezoelectric-electromagnetic coupling vibration energy collection device, thereby achieving efficient energy collection under complex operating conditions.

[0024] 2. The present invention sets a curved piezoelectric transducer in the magnetic part, which improves the utilization rate of the magnetic force in the electromagnetic part of the piezoelectric-electromagnetic coupling vibration energy collection device, and simultaneously realizes the collection of vibration energy of three parts: the piezoelectric cantilever beam, the electromagnetic coil, and the curved piezoelectric transducer, thereby improving the vibration energy collection effect of the device and collecting vibration energy to the greatest extent.

[0025] 3. The piezoelectric cantilever beam, electromagnetic coil and bending piezoelectric transducer in the present invention have a stable structure, are easy to assemble and manufacture, and are suitable for working under low-frequency and large-amplitude vibration conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of the overall structure of a piezoelectric-electromagnetic hybrid vibration energy harvesting device with continuously adjustable resonant frequency.

[0027] Figure 2 Schematic diagram of the energy collection bracket of the piezoelectric-electromagnetic hybrid vibration energy collection device with continuously adjustable resonant frequency.

[0028] Figure 3 A 45-degree side view of the overall structure of a piezoelectric-electromagnetic hybrid vibration energy harvesting device with continuously adjustable resonant frequency.

[0029] Figure 4 Schematic diagram of the piezoelectric cantilever beam structure and the aluminum clamping platform.

[0030] Figure 5 Schematic diagram of the position relationship between the piezoelectric cantilever beam and the electromagnetic coil.

[0031] Figure 6 Schematic diagram of the position relationship between the piezoelectric cantilever beam and the bending piezoelectric transducer.

[0032] Figure 7 It is a top view of the electromagnetic coil structure.

[0033] Figure 8 Schematic diagram of the position relationship between the coil frame and the bending piezoelectric transducer.

[0034] Fig. 9 Schematic diagram of the bending piezoelectric transducer structure.

[0035] In the figure, 1. energy collection bracket; 2. piezoelectric cantilever beam; 3. electromagnetic coil; 4. bending piezoelectric transducer; 11. upper bracket; 12. bolt; 13. nut; 14. lower bracket; 15. aluminum substrate; 16. piezoelectric ceramics; 17. aluminum clamping platform; 18. piezoelectric cantilever beam magnet; 19. coil frame; 20. coil; 21. coil placement platform; 22. bending piezoelectric transducer magnet; 23. piezoelectric ceramics; 24. bending clip. DETAILED DESCRIPTION

[0037] The specific embodiments of the present invention will be described in detail below. In order to avoid too much unnecessary details, the well-known structures or functions will not be described in detail in the following examples. The approximate language used in the following examples can be used for quantitative expression, indicating that the quantity can be allowed to have a certain change without changing the basic function. Unless otherwise defined, the technical and scientific terms used in the following examples have the same meanings as those generally understood by those skilled in the art to which the present invention belongs.

[0038] The present invention is further described in detail below in conjunction with the embodiments and drawings. Figure 1 The figure shows the overall structure schematic diagram of a piezoelectric-electromagnetic coupling vibration energy harvesting device with continuously adjustable resonant frequency, including an energy harvesting bracket 1, a piezoelectric cantilever beam 2, an electromagnetic coil 3, and a bending piezoelectric transducer 4.

[0039] Figure 2 The energy collection bracket of the piezoelectric-electromagnetic hybrid vibration energy collection device with continuously adjustable resonant frequency shown in the figure, the energy collection bracket 1 comprises an upper bracket 11, a bolt 12, a nut 13, and a lower bracket 14. The upper bracket 11 and the lower bracket 14 are passed through by the bolt 12, and the vertical position is fixed by the nut 13. The lower bracket 14 can be fixed at a position where the working part excites intense vibration by the bolt 12 and the nut 13.

[0040] Figure 4 The piezoelectric cantilever beam structure shown in the figure is matched with the aluminum clamping platform. The piezoelectric cantilever beam 2 includes a piezoelectric ceramic 16, an aluminum substrate 15, and a piezoelectric cantilever beam magnet 18. The aluminum substrate 15 is clamped and fixed in the middle position by the aluminum clamping platform 17. The piezoelectric ceramic 16 is glued to the root of the piezoelectric cantilever beam 2 and is close to the aluminum clamping platform 17 by epoxy resin glue. The piezoelectric cantilever beam magnet 18 is glued to the end of the piezoelectric cantilever beam 2.

[0041] Figure 5 The figure shows the position relationship between the piezoelectric cantilever beam and the electromagnetic coil, including the coil frame 19, the coil 20, and the coil placement table 21. The coil 20 is evenly wound on the coil frame 19, and the coil frame 19 is placed on the coil placement table 21 to ensure that the coil frame 19 and the piezoelectric cantilever beam magnet 18 are coaxial.

[0042] Figure 8 The figure shows the positional relationship between the coil frame and the bending piezoelectric transducer. The bending piezoelectric transducer 4 includes a bending piezoelectric transducer magnet 22, a piezoelectric ceramic 23, and a bending clip 24. The diameter of the bending piezoelectric transducer magnet 22, the width of the piezoelectric ceramic 23, and the width of the bending clip 24 are equal.

[0043] The curved piezoelectric transducer magnet 22 is glued to the top of the curved clip 24 by epoxy resin glue, and the piezoelectric ceramic 23 is glued between the two curved clips 24 by epoxy resin glue, ensuring that the center of the curved piezoelectric transducer magnet 22 coincides with the middle position of the top of the curved clip 24, and the curved clip 24 is glued to the surface of the upper bracket 11 and the lower bracket 14.

[0044] Working process of the piezoelectric-electromagnetic coupling vibration energy harvesting device with continuously adjustable resonant frequency:

[0045] When the machine is operating under variable working conditions, the vibration characteristics are analyzed to obtain the frequency domain data of the vibration. According to the obtained frequency domain data, the nut 13 is turned to adjust the position of the upper bracket 11 and the lower bracket 14, the magnetic moment is changed, and energy collection begins; the lower bracket 14 is fixed to the surface of the position where the working part of the machine vibrates violently by the bolt 12 and the nut 13, receives the vertical vibration transmitted by the working part, and transmits it to the bolt 12, and the aluminum clamp 17 is nested on the bolt 12. The vibration is transmitted to the piezoelectric cantilever beam 2 by the aluminum clamp 17, and the aluminum substrate 15 vibrates, and the end moves up and down. The piezoelectric ceramic at the root of the piezoelectric cantilever beam 2 16 is subjected to squeezing force and shearing force, and due to the positive piezoelectric effect, the internal charge moves to generate voltage; when the end of the aluminum substrate 15 moves up and down, the piezoelectric cantilever beam magnet 18 attached to the end moves up and down, causing the magnetic flux inside the coil 20 to change, and current is generated inside the coil to generate electrical energy; at the same time, the piezoelectric cantilever beam magnet 18 moves up and down, and the bending piezoelectric transducer magnet 22 in the bending piezoelectric transducer 4 is subjected to the magnetic force from the piezoelectric cantilever beam magnet 18, and an squeezing force is applied to the bending clip 24, and the bending clip 24 acts evenly on the piezoelectric ceramic 23, and the piezoelectric ceramic 23 generates voltage in the same principle as before.

[0046] The embodiments described are only preferred implementations of the present invention, but the present invention is not limited to the above implementations. Any obvious improvements, substitutions or modifications that can be made by any technician familiar with the technical field belong to the protection scope of the present invention.

Claims

1. A piezoelectric-electromagnetic coupling vibration energy harvesting device with continuously adjustable resonant frequency, characterized in that: include: An energy collection bracket (1), a piezoelectric cantilever beam (2), an electromagnetic coil (3), and a bending piezoelectric transducer (4); the energy collection bracket (1) comprises an upper bracket (11), a bolt (12), a nut (13), and a lower bracket (14); a circular through hole with a diameter of 5 to 10 mm is opened at the center of the lower bracket (14); the energy collection bracket (1) is fixed to an external excitation device via a bolt (12); the upper bracket (11) and the lower bracket (14) are connected and fixed via a bolt (12) and a nut (13); the piezoelectric cantilever beam (2) comprises an aluminum substrate (15) and a piezoelectric ceramic (16); the piezoelectric cantilever beam (2) is clamped and fixed by an aluminum clamp (17); the length of the aluminum clamp (17) clamping the aluminum substrate (15) is 20 to 30 mm; the electromagnetic coil (3) comprises a coil frame (19), a coil (20), and a coil placement platform (21), wherein the coil placement platform (21) is adhered to the inner surfaces of the upper bracket (11) and the lower bracket (14) by epoxy resin glue, the coil (20) is wound on the coil frame (19), and the coil frame (19) is adhered to the surface of the coil placement platform (21) by epoxy resin glue; the bending piezoelectric transducer (4) comprises a bending clip (24), a bending piezoelectric transducer magnet (22), and a piezoelectric ceramic (23), the bending clip (24) clamps the piezoelectric ceramic (23) in the middle, the bottom of the bending clip (24) made of 65Mn is adhered to the surface of the upper bracket (11) and the lower bracket (14) by epoxy resin glue, and the upper and lower parts of the bending piezoelectric transducer (4) are symmetrical.

2. A piezoelectric-electromagnetic coupling vibration energy harvesting device with continuously adjustable resonant frequency according to claim 1, characterized in that: The bolts (12) pass through round through holes with a diameter of 5 to 10 mm on both sides of the aluminum clamping platform (17), and are fixedly clamped by nuts (13) to clamp the piezoelectric cantilever beam (2).

3. The piezoelectric-electromagnetic coupling vibration energy harvesting device with continuously adjustable resonant frequency according to claim 1, characterized in that: The piezoelectric ceramic (16) is glued to the root of the aluminum substrate (15) with epoxy resin glue, and the piezoelectric cantilever beam magnet (18) is glued to the end of the piezoelectric cantilever beam (2) with epoxy resin glue, and the end piezoelectric cantilever beam magnet (18) is symmetrical up and down.

4. The piezoelectric-electromagnetic coupling vibration energy harvesting device with continuously adjustable resonant frequency according to claim 1, characterized in that: A circular hole is provided at the center of the coil placement platform (21), the curved piezoelectric transducer magnet (22) passes through the circular hole of the coil placement platform (21), the curved piezoelectric transducer magnet (22) is placed inside the coil frame (19), the coil frame (19) and the curved piezoelectric transducer magnet (22) are coaxial, and the electromagnetic coil (3) is symmetrical up and down.

5. The piezoelectric-electromagnetic coupling vibration energy harvesting device with continuously adjustable resonant frequency according to claim 1, characterized in that: The angle between the bent clip (24) and the piezoelectric ceramic (23) is in the range of 15-25°, the diameter of the bent piezoelectric transducer magnet (22) is equal to the width of the piezoelectric ceramic (23) and the bent clip (24), and the bent piezoelectric transducer magnet (22) is coaxial with the piezoelectric cantilever beam magnet (18).

6. According to claim 1, a piezoelectric-electromagnetic coupling vibration energy collection device with continuously adjustable resonant frequency, which simultaneously collects vibration energy of three parts: a piezoelectric cantilever beam (2), an electromagnetic coil (3), and a bending piezoelectric transducer (4), characterized in that: The magnetic distance between the piezoelectric cantilever beam magnet (18) and the bending piezoelectric transducer magnet (22) is continuously adjusted by the upper bracket (11), the lower bracket (14) and the nut (12); the piezoelectric cantilever beam (2) receives vibration through the aluminum clamping platform (17); the piezoelectric cantilever beam end magnet (18) synchronously drives the electromagnetic coil (3) and the bending piezoelectric transducer (4) to collect vibration energy; the piezoelectric cantilever beam end magnet (18) and the electromagnetic coil (3) and the bending piezoelectric transducer (4) are at the same vertical position.

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