A bistable vibration energy harvesting device incorporating an inertial mass converter structure

Abstract

The present invention discloses a bistable vibration energy harvesting device including an inertial capacitance structure. The present invention includes an elastic element, a coil permanent magnet structure and a triple-body structure arranged axially symmetrically, wherein the symmetrically arranged coil permanent magnet structures are connected by a connecting rod structure, and the coil permanent magnet structure is also connected to the inner wall of the device body through the elastic element and the triple-body structure; the triple-body structure includes a second bracket, one end of which is connected to the inner wall of the device body, and the other end is hinged to a long rod with a mass block at one end, and the other end of the long rod is movably connected to a groove-shaped bracket on the outer side of the permanent magnet in the coil permanent magnet structure. The mass block and the long rod form an inertial capacitance structure for reducing the energy barrier of the device. Since the present invention has the bistable double-well restoring force potential energy characteristic, it has a smaller starting excitation, enabling a larger movement amplitude of the permanent magnet and more energy harvesting.

Description

Technical Field

[0001] The present invention relates to an energy harvesting device, specifically a bistable vibration energy harvesting device incorporating an inertial mass damper structure. Background Art

[0002] Due to the potential application prospect of vibration energy harvesters in replacing traditional batteries, it has always been a hot research field. There are many vibrations in the low-frequency domain in daily life. For example, the vibration frequency of a human body when walking is about 1 Hz, and the relative movement between a permanent magnet and a coil can generate up to 28 mW of electric energy. Due to the high magnetic flux change rate, the relative movement between the coil and the magnet has a good ability to convert vibration energy into electric energy. People need to create a new type of energy harvesting device that is environmentally friendly and can generate electricity sustainably. The bistable vibration energy harvesting technology incorporating an inertial mass damper structure has thus attracted people's attention. Summary of the Invention

[0003] In order to overcome the problem of low energy harvesting efficiency of existing devices, the present invention proposes a bistable vibration energy harvesting device incorporating an inertial mass damper structure, which has a peak energy with a wider frequency band and can overcome the energy barrier to obtain a larger vibration amplitude, thereby converting vibration into more electric energy.

[0004] The present invention includes an elastic element, a coil permanent magnet structure, and a triple-body structure arranged axially symmetrically. Among them, the symmetrically arranged coil permanent magnet structures are connected by a connecting rod structure, and the coil permanent magnet structure is also connected to the inner wall of the device body through the elastic element and the triple-body structure;

[0005] The triple-body structure includes a second bracket, one end of which is connected to the inner wall of the device body, and the other end is hinged to a long rod with a mass block at one end. The other end of the long rod is movably connected to a groove-shaped bracket fixed on the outside of the permanent magnet in the coil permanent magnet structure. The mass block and the long rod form an inertial mass damper structure for reducing the energy barrier of the device;

[0006] The coil permanent magnet structure includes a coil and a permanent magnet. The permanent magnet is placed on a smooth plane, and the coil is sleeved outside the permanent magnet. The permanent magnet is grooved on both sides and nested with the long rod connected to the inner wall of the device body to ensure that the permanent magnet always moves in a horizontal straight line when the device is forced to vibrate.

[0007] The beneficial effects of the present invention are as follows: From the perspective of energy harvesting efficiency, when the device is excited in the vertical direction, due to the bistable double-well restoring force potential energy characteristic of the present invention, it has a smaller starting excitation than general devices, making the movement amplitude of the permanent magnet larger and harvesting more energy; and the inertial mass damper structure in the device can reduce the energy barrier of the bistable structure, thus greatly improving the energy harvesting efficiency; and when there is a horizontal excitation, the device can also achieve energy collection. Brief Description of the Drawings

[0008] Figure 1 This is the front view of the present invention.

[0009] Figure 2 This is the three - dimensional side view of the present invention.

[0010] Figure 3 This is the three - dimensional view of the triple - body structure of the present invention.

[0011] In the figure: 1. Device body, 2. Coil permanent - magnet structure, 3. Triple - body structure, 4. Spring, 5. Linkage structure, 6. Coil, 7. Permanent magnet, 8. Mass block, 9. Long rod, 10. Smooth plane, 11. Inner wall of the device body, 12. First bracket, 13. I - shaped rigid rod, 14. Grooved bracket, 15. Slotted long rod, 16. Second bracket. Detailed Description of the Preferred Embodiments

[0012] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0013] As Figure 1 shown, the device in this embodiment includes a device body 1, a coil - magnet structure 2, a triple - body structure 3, a spring 4, and a linkage structure 5. The coil - magnet structure 2, the triple - body structure 3, the spring 4, and the linkage structure 5 are located inside the device body.

[0014] As Figure 2 shown, the interior of the device is an axisymmetric structure. On both the left and right sides, there are respectively a triple - body structure 3, a spring 4, a coil 6, and a permanent magnet 7. The permanent magnet 7 is placed on a smooth plane 10 and is connected to the inner wall 11 of the device body through the spring 4 and the triple - body structure 3. The two sides of the permanent magnet 7 are grooved and nested with the long rod 9 connected to the inner wall 11 of the device body to ensure that the permanent magnet 7 always moves in a horizontal straight line when the device vibrates. The two coils 6 are respectively sleeved outside the two permanent magnets 7, and the inner sides of the permanent magnets 7 are connected through the linkage structure 5.

[0015] The device body 1 is manufactured by 3D printing technology, and the long rod 9 and the smooth plane 10 are made of hard alloy after grinding.

[0016] As Figure 3 shown, the triple - body structure 3 includes a second bracket 16 connected to the inner wall 11 of the device body. The other end of the second bracket 16 is hinged to a slotted long rod 15 with a mass block 8 at one end. The lower side of the slotted long rod 15 is connected to the grooved bracket 14 fixed on the permanent magnet 7.

[0017] The mass block 8 in the triple structure 3 is made of high-speed steel and weighs 1 kg. The slotted long rod 15, the bracket 12, and the grooved bracket 14 are all manufactured by 3D printing technology, and stainless steel rods are used as hinges to connect the components.

[0018] The spring 4 in the device is manufactured by MYSUMI-VONA, and the model is WFSP9-1.2-30.

[0019] The coil 6 in the coil permanent magnet structure 2 of the device is made of copper wire with a radius of 1.5 mm; the permanent magnet 7 is a ground rare earth permanent magnet with NdFe35 as its material, with a length of 7 cm, a width of 5 cm, and a height of 5 cm.

[0020] The connecting rod structure 5 in the device connects two permanent magnets 7 on the smooth plane 10 inside the device. The connecting rod structure 5 is composed of two I-shaped rigid rods 13 connected by hinges and is respectively fixed on the first bracket 12 on one side of the permanent magnet 7 by means of hinge connection.

[0021] The I-shaped rigid rod 13 in the connecting rod structure 5 is made of 45# steel and has a certain mass to achieve a bistable effect when the device is forced to vibrate.

[0022] The device has the characteristics of bistable double-well restoring force potential energy, requiring a smaller starting excitation, having a larger movement amplitude of the permanent magnet, and collecting more energy; and the inertia capacitance structure in the device can reduce the energy barrier of the bistable structure, thus greatly improving the energy collection efficiency.

[0023] The working principle of the device in this embodiment: When the device is subjected to a continuous vertical excitation, the connecting rod structure 5 will be forced to swing up and down, thereby driving the permanent magnet to move back and forth in the horizontal direction. According to Faraday's law of electromagnetic induction, the permanent magnet 7 moves to cut the magnetic induction line to generate an induced current and an induced electromotive force. And the device has a bistable structure, with a smaller starting excitation than ordinary devices, making the movement amplitude of the permanent magnet larger and collecting more energy. Moreover, the mass block and the long rod in the three-link structure are equivalent to an inertia capacitance. Inertia capacitance is an inertial amplification element at both ends. When the device moves, it can reduce the energy barrier of the bistable structure, and the system is easier to cross the barrier and perform large-amplitude periodic motion between the two potential wells. The inertia capacitance structure can make the connecting rod swing more easily from one stable state to another stable state, making the movement amplitude of the permanent magnet larger, so as to obtain more electric energy. When there is a horizontal excitation acting on the device, at this moment, the permanent magnet moves horizontally by itself to cut the magnetic induction line, generating a certain induced electromotive force and also being able to achieve energy collection. Therefore, the device has the advantages of bidirectional energy collection and higher electric energy conversion rate.

Claims

1. A bistable vibration energy harvesting device comprising an inertial capacitance structure, characterized in that: it includes an elastic element, a coil permanent magnet structure and a triple-body structure arranged axially symmetrically, wherein the symmetrically arranged coil permanent magnet structures are connected by a connecting rod structure, and the coil permanent magnet structure is also connected to the inner wall of the device body through the elastic element and the triple-body structure; the triple-body structure includes a second bracket, one end of which is connected to the inner wall of the device body, and the other end is hinged to a slotted long rod with a mass block at one end, and the other end of the slotted long rod is movably connected to a slotted bracket on the outside of the permanent magnet in the coil permanent magnet structure, and the mass block and the slotted long rod form an inertial capacitance structure for reducing the energy barrier of the device; the coil permanent magnet structure includes a coil and a permanent magnet, the permanent magnet is placed on a smooth plane, the coil is sleeved outside the permanent magnet, and the permanent magnet is grooved on both sides and nested with a long rod connected to the inner wall of the device body to ensure that the permanent magnet always moves in a horizontal straight line when the device is forced to vibrate; the connecting rod structure connects two permanent magnets on the smooth plane inside the device, and the connecting rod is composed of two I-shaped rods connected by a hinge and is respectively fixed on the first bracket on the inner side of the permanent magnet by a hinged manner. The I-shaped rod has a certain mass to achieve a bistable effect when the device is forced to vibrate; the elastic element is a spring, the spring is located below the triple-body structure, one end of the spring is connected to the permanent magnet, and the other end is connected to the inner wall of the device body.

2. The bistable vibration energy harvesting device comprising an inertial capacitance structure according to claim 1, characterized in that: the device body is made by 3D printing, the long rod and the smooth plane are horizontally installed in the device body, and the materials of the long rod and the smooth plane are cemented carbide.

3. The bistable vibration energy harvesting device comprising an inertial capacitance structure according to claim 1, characterized in that: the material of the mass block is high-speed steel, the material of the coil is copper, and the permanent magnet is a ground rare earth permanent magnet with NdFe35 as its material.

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