A frequency-upgrading vibration energy harvester

Abstract

This invention discloses a frequency-upgrading vibration energy harvester, belonging to the field of energy harvesting. It includes a first bending spring, a connector, a coil frame, a support rod, a coil, and a magnet. The first bending spring designed in this invention has non-linearity, which can broaden the energy harvesting frequency band and increase the output power. Furthermore, when the first bending spring drives the magnet to vibrate at low frequencies, the tab on the connector collides with the slot in the coil frame. After the collision, the second bending spring drives the coil to vibrate at high frequencies, achieving a frequency upgrading effect. This results in a high-frequency relative displacement between the coil and the magnet, inducing a high-frequency electromotive force, ultimately further broadening the energy harvesting frequency band.

Description

Technical Field

[0001] This invention belongs to the field of energy harvesting, and more specifically, relates to an up-frequency vibration energy harvester. Background Technology

[0002] In the context of the Internet of Things, wireless sensors have been widely used due to their advantages of long transmission distance and low power consumption. However, the traditional battery-powered approach for wireless sensors suffers from limited lifespan and difficulty in replacement. The environment contains various forms of energy, such as thermal, solar, wind, and vibration energy. Harvesting environmental energy to power wireless sensors offers a new solution to these problems. While solar, wind, and thermal energy are easily affected by weather changes and geographical limitations, vibration energy is extremely widespread, present in industrial equipment, construction, transportation, and human movement. Harvesting vibration energy to power wireless sensors not only supports their widespread deployment but also has strong engineering applicability.

[0003] Currently, the most common vibration energy harvesting methods proposed by researchers both domestically and internationally are electromagnetic and piezoelectric, based on the principles of electromagnetic induction and the piezoelectric effect, respectively. Electromagnetic vibration energy harvesters are characterized by high output power. However, most common electromagnetic vibration energy harvesting devices are resonant energy harvesting devices, which use resonance to cause a large displacement in the vibration-collecting structure, thereby outputting high power. The disadvantage of this type of device is its single operating frequency, limiting its ability to harvest energy only at specific frequencies in the environment, thus severely restricting its application scenarios. Since vibration energy in the environment is random and time-varying, to better harvest vibration energy, vibration energy harvesting devices need to be able to collect vibration energy across a wide frequency range. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide an up-frequency vibration energy harvester, which aims to solve the problem of the single operating frequency of existing electromagnetic vibration energy harvesting devices.

[0005] To achieve the above objectives, the present invention provides a frequency-upgrading vibration energy harvester, comprising two first bending springs, two connectors, and a magnet. The two connectors are respectively disposed at both ends of the magnet, and the two first bending springs are connected to the upper and lower ends of the magnet via the two connectors. An overall frame is placed inside a coil frame, and a coil groove is provided on the side of the coil frame facing away from the overall frame, with the coil wound within the coil groove. A slot is provided on the side of the coil frame near the overall frame, and a lever is provided on the outer periphery of the connector. The lever is inserted into the slot, and the first bending springs drive the lever to collide with the inner wall of the slot to achieve frequency upgrading.

[0006] Furthermore, the frequency-increasing vibration energy harvester also includes two upper disks. The two ends of one of the two first bending springs are respectively connected to a connector and an upper disk. The two ends of the other first bending spring are respectively connected to another connector and another upper disk. The two upper disks are respectively disposed at the two ends of the magnet, and the upper disks and the connectors are spaced apart from each other.

[0007] Furthermore, the first bending spring is a serpentine bending beam spring, which is connected to the plane of the upper disc and the plane of the connecting piece at a certain angle.

[0008] Furthermore, the frequency-increasing vibration energy harvester also includes two lower disks, which are respectively disposed at both ends of the magnet. One lower disk is disposed on a connector on the side away from the magnet, and the other lower disk is disposed on another connector on the side away from the magnet. A first bending spring is disposed between the lower disk and the upper disk.

[0009] Furthermore, the upper disk, the lower disk, and the connector are all provided with threaded holes at their centers, and the diameter of each threaded hole is the same. One end of the first bending spring is fixedly connected to the threaded hole of the upper disk by a screw, and the other end of the first bending spring passes through the threaded hole of the lower disk and is fixedly connected to the threaded hole of the connector by a screw.

[0010] Furthermore, the connector is attached to the magnet with glue, and the cross-sectional diameter of the connector is the same as that of the magnet.

[0011] Furthermore, the first bending spring is a serpentine bending beam spring, which is connected to the planes of the upper and lower discs at a certain angle. The serpentine bending beam springs are three-dimensional, and there are two or more of them, preferably three.

[0012] Furthermore, the coil frame includes a coil support member and two upper support planes, the two upper support planes are spaced apart from each other, the coil support member is disposed between the two upper support planes, the coil support member and the two upper support planes are provided with a first through hole, the overall frame is installed in the first through hole, and a second bending spring is provided between the coil support member and either upper support plane;

[0013] The coil support has a coil groove on the side facing away from the overall frame, and a slot on the side of the coil support closer to the overall frame.

[0014] Furthermore, the connector is cylindrical, with four paddles for collision around its center. Four paddles are arranged in a circumferential array around the connector. On the coil frame, near the overall frame, there are four slots corresponding to the four paddles, with the openings of the slots facing away from the openings of the coil grooves.

[0015] Furthermore, the coil frame also includes a central support plane, and there are two coil supports. The central support plane is disposed between the two coil supports, and a second bending spring is provided between each coil support and the central support plane. The two coil supports and the central support plane are disposed between two upper support planes. This design results in two coil grooves in the coil frame, and each coil groove is connected to the central support plane and the upper support planes of the coil frame by multiple second bending springs. The number of second bending springs is an even number of six or more, preferably eight. The two coil grooves are symmetrically distributed vertically; therefore, the preferred number of second bending springs in this invention is 16.

[0016] Furthermore, four levers are provided on the connector, arranged in a circumferential array along the connector. Four slots, corresponding one-to-one with the four levers, are provided on the side of the coil frame near the overall frame, with the openings of the slots facing away from the openings of the coil recesses. Each coil recess in the coil frame has four slots on its back side, with the center plane of each slot being the same as the center plane of the corresponding connector, and the width of the slot slightly wider than the width of the connector's levers. In this case, the connector's levers can fit perfectly into the slots. When external excitation vibration causes the first bending spring to drive the magnet and connector to vibrate at a low frequency, the connector's levers will collide with the upper and lower surfaces of the slots during vibration. After the collision, since the slots, coil recesses, and coils are integrated, and the characteristic frequency of the second bending spring connected to them is high, the second bending spring will cause the coil to vibrate at a high frequency with gradually decreasing amplitude at its characteristic frequency.

[0017] Furthermore, the frequency-upgrading vibration energy harvester also includes multiple support rods, with each support rod having its two ends connected to two upper support planes. The length of the support rod is the height of the coil support plus the natural length of the two second bending springs between the coil support and the two upper support planes.

[0018] Furthermore, the second bending spring is a straight bending beam spring.

[0019] Compared with the prior art, the above-described technical solutions conceived in this invention can achieve the following results.

[0020] Beneficial effects:

[0021] 1. In this invention, the first bending spring is designed to be nonlinear. Under the same vibration acceleration, this characteristic can have a larger vibration displacement at the non-resonant frequency compared to the traditional linear helical spring. Therefore, it can achieve the beneficial effects of broadening the energy harvesting frequency band and increasing the output power.

[0022] 2. When the first bending spring drives the magnet to vibrate at low frequency, it causes the lever on the connector to collide with the slot in the coil frame. After the collision, the second bending spring drives the coil to vibrate at high frequency, achieving a frequency upscaling effect. Since the lever and slot are in direct contact under normal conditions, even a small vibration displacement of the first bending spring will cause the lever to collide with the slot, thus completing the frequency upscaling process. After frequency upscaling, a high-frequency relative displacement is generated between the coil and the magnet, inducing a high-frequency electromotive force. Therefore, when the external excitation vibration frequency is far from the resonant frequency of the energy harvester, even a small vibration displacement of the first bending spring can still excite high-frequency vibration in the coil, thus further achieving the beneficial effect of broadening the energy harvesting frequency band. Attached Figure Description

[0023] Figure 1 This is a structural diagram of the first bending spring.

[0024] Figure 2 This is a structural diagram of the connector.

[0025] Figure 3 This is an overall frame diagram of the first bending spring, connector, and magnet.

[0026] Figure 4 This is a structural diagram of the coil frame.

[0027] Figure 5 This is a sectional view of the overall device.

[0028] Figure 6 This is an integrated diagram of the entire device.

[0029] Figure 7 This is the output voltage waveform. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0031] The frequency-upgrading vibration energy harvester includes two first bending springs 1, two connectors 2, and a magnet 3. The two connectors 2 are located at the upper and lower ends of the magnet 3, and the two first bending springs 1 are connected to the upper and lower ends of the magnet 3 through the two connectors 2. The overall frame is placed inside a coil frame 4. The coil frame 4 has a coil groove 7 on the side opposite to the overall frame, and a coil 6 is wound in the coil groove 7. The coil frame 4 has a slot 8 on the side near the overall frame, and a lever is provided on the outer periphery of the connector 2. The lever is inserted into the slot 8, and the first bending springs 1 drive the lever to collide with the inner wall of the slot 8 to achieve frequency upgrading. It also includes an upper disk 12 and a lower disk 13. The two ends of one of the two first bending springs 1 are respectively connected to one end of the magnet 3 and the upper disk 12, and the two ends of the other first bending spring 1 are respectively connected to the other end of the magnet 3 and the lower disk 13.

[0032] The coil frame 4 includes a coil support and two upper support planes 11. The two upper support planes 11 are spaced apart from each other. The coil support is disposed between the two upper support planes 11. The coil support and the two upper support planes 11 are each provided with a first through hole. The overall frame is installed in the first through hole. A second bending spring 9 is provided between the coil support and any of the upper support planes 11.

[0033] The coil support has a coil groove 7 on the side away from the overall frame, and a slot 8 on the side of the coil support close to the overall frame.

[0034] Specifically, the frequency-upgrading vibration energy harvester also includes multiple support rods 5, with each support rod 5 having its two ends connected to two upper support planes 11 respectively. The length of the support rod 5 is the height of the coil support plus the natural length of the two second bending springs 9 between the coil support and the two upper support planes 11.

[0035] Specifically, the frequency-upgrading vibration energy harvester also includes two upper discs 12. The two ends of one of the two first bending springs 1 are respectively connected to a connector 2 and an upper disc 12. The two ends of the other first bending spring 1 are respectively connected to another connector 2 and another upper disc 12. The two upper discs 12 are respectively disposed at the two ends of the magnet 3, and the upper discs 12 and the connector 2 are spaced apart from each other.

[0036] Specifically, the first bending spring 1 is a serpentine bending beam spring, which is connected to the plane of the upper disc 12 and the plane of the connecting piece 2 at a certain angle.

[0037] Specifically, the frequency-increasing vibration energy harvester also includes two lower disks 13, which are respectively disposed at both ends of the magnet 3. One lower disk is disposed on a connector on the side away from the magnet, and the other lower disk is disposed on another connector on the side away from the magnet. A first bending spring is disposed between the lower disk and the upper disk.

[0038] Specifically, the upper disk, the lower disk, and the connector are all provided with threaded holes at their centers, and the diameter of each threaded hole is the same. One end of the first bending spring is fixedly connected to the threaded hole of the upper disk by a screw, and the other end of the first bending spring passes through the threaded hole of the lower disk and is fixedly connected to the threaded hole of the connector by a screw.

[0039] Two upper support planes 11 are disposed between two upper discs 12. One upper disc 12 is connected to one of the two upper support planes 11 by a snap fastener, and the other upper disc 12 is connected to the other upper support plane 11 by a snap fastener.

[0040] Specifically, the coil frame 4 also includes a central support plane 10, and there are two coil supports. The central support plane 10 is disposed between the two coil supports. A second bending spring 9 is provided between each coil support and the central support plane 10. The two coil supports and the central support plane are disposed between two upper support planes.

[0041] Figure 1 The first bending spring 1 of this invention is a serpentine bending beam spring, which connects two upper and lower circular planes at a certain angle to the plane. This design retains the advantage of the wide frequency range of the first bending spring, while also increasing the spring's vibration displacement, which facilitates the collision of the lever with the slot 8 in the coil frame 4, thereby bringing about a frequency upscaling effect. This first bending spring can be manufactured using nylon material through 3D printing, and the frequency band of vibration energy harvesting can be adjusted by changing the beam length, beam width, and number of beams in the first bending spring 1.

[0042] Figure 2 The connector 2 is made of copper and has four evenly distributed tabs around its perimeter. These tabs collide with the slots 8 inside the coil frame 4 to achieve frequency upscaling. The connector 2 has a threaded hole at its center, which is connected to the lower disc of the first bending spring 1 by a screw.

[0043] Figure 3 This is an overall frame diagram of the first bending spring 1, the connector 2, and the magnet 3. The first bending spring 1 is connected to the connector 2 by screws, and the connector 2 is connected to the magnet 3 by glue. The overall frame consists of two first bending springs 1, two connectors 2, and one magnet. The first bending springs 1 and the connectors 2 are symmetrically distributed at the upper and lower ends of the magnet 3.

[0044] Figure 4 The coil frame 4 has each coil groove 7 connected to the upper and lower support planes by eight second bending springs 9. The coil frame 4 has a total of 2 coil grooves and 16 second bending springs. The coil frame can be made of nylon material by 3D printing. The vibration frequency of the coil 6 after frequency boosting can be adjusted by adjusting the number of second bending springs, the spring length, and the spring width.

[0045] Figure 5 The cross-sectional view of the overall device shows four slots 8 inside the coil frame 4 corresponding to the positions of the connector 2. These slots 8 can hold the four levers of the connector 2, and the width of the slots is slightly wider than the width of the levers. The back of the slots 8 corresponds to the coil grooves 7. This design allows the low-frequency vibration of the magnet to drive the coil to vibrate at a high frequency, achieving a frequency upscaling effect. The output characteristics of the energy harvester can also be adjusted by changing the width of the slots 8.

[0046] Figure 6 The overall diagram of the device shows that the first bending spring 1, the connector 2 and the magnet 3 are located inside the coil frame 4; the support rod 5 is used to support the coil frame, and its length is the coil groove 7 plus the natural length of the upper and lower springs; the coil 6 is wound in the coil groove 7 of the coil frame 4.

[0047] Figure 7 The diagram shows the output voltage waveform under sinusoidal vibration excitation in an example of this invention. Low-frequency excitation vibration can generate a high-frequency output voltage. In stage t1 of the diagram, the lever in this invention has not yet collided with the slot, and the output voltage is determined by the vibration of the magnet. In stage t2 of the diagram, after the lever collides with the slot, the coil is excited to generate high-frequency vibration, thereby producing a high-frequency output voltage. Near the characteristic frequency of the first bending spring, even a small vibration excitation can produce sufficient vibration displacement to make the lever collide with the slot. If it deviates from the characteristic frequency of the first bending spring, the width of the slot can be reduced to allow the lever to collide with the slot, achieving a high-frequency voltage output. Therefore, this invention can amplify the low-frequency vibration of a magnet over a wide range into the high-frequency vibration of the coil, and the frequency of the high-frequency vibration is determined by the characteristic frequency of the second bending spring to which the coil is connected. Compared to a single-resonant-point vibration energy harvester, this invention can collect vibration energy over a wider frequency range.

[0048] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A frequency-upgrading vibration energy harvester, characterized in that, The system includes an overall frame, which includes two first bending springs (1), two connectors (2), and a magnet (3). The two connectors (2) are respectively located at both ends of the magnet (3). The two first bending springs (1) are connected to the upper and lower ends of the magnet (3) through the two connectors (2). The overall frame is placed inside a coil frame (4). A coil groove (7) is provided on the side of the coil frame (4) away from the overall frame. A coil (6) is wound in the coil groove (7). A slot (8) is provided on the side of the coil frame (4) near the overall frame. A paddle is provided on the outer periphery of the connector (2). The paddle is inserted into the slot (8). The first bending springs (1) drive the paddle to collide with the inner wall of the slot (8) to achieve frequency boosting. It also includes two upper discs (12), one of the two first bending springs (1) is connected at both ends to a connector (2) and an upper disc (12) respectively, and the other of the two first bending springs (1) is connected at both ends to another connector (2) and another upper disc (12) respectively, and the two upper discs (12) are respectively set at both ends of the magnet (3), and the upper discs (12) and the connector (2) are spaced apart from each other; The coil frame (4) includes a coil support and two upper support planes (11). The two upper support planes (11) are spaced apart from each other. The coil support is located between the two upper support planes (11). The coil support and the two upper support planes (11) are provided with a first through hole. The overall frame is installed in the first through hole. A second bending spring (9) is provided between the coil support and any upper support plane (11). The coil support has a coil groove (7) on the side away from the overall frame and a slot (8) on the side close to the overall frame.

2. The frequency-upgrading vibration energy harvester according to claim 1, characterized in that... The first bending spring (1) is a serpentine bending beam spring, which is connected to the plane of the upper disc (12) and the plane of the connecting piece (2) at a certain angle.

3. The frequency-upgrading vibration energy harvester according to claim 1, characterized in that, Four paddles are provided on the connector (2), and the four paddles are arranged in a circumferential array along the connector (2). The coil frame (4) has four slots (8) on one side near the overall frame that correspond to the four paddles, and the openings of the slots (8) are set opposite to the openings of the coil grooves (7).

4. The frequency-upgrading vibration energy harvester according to claim 1, characterized in that, It also includes multiple support rods (5), with each support rod (5) having its two ends connected to two upper support planes (11). The length of the support rod (5) is the height of the coil support plus the natural length of the two second bending springs (9) between the coil support and the two upper support planes (11).

5. The frequency-upgrading vibration energy harvester according to claim 1, characterized in that, Two upper support planes (11) are set between two upper discs (12). One upper disc (12) is connected to one of the two upper support planes (11) by a snap fastener, and the other upper disc (12) is connected to the other upper support plane (11) by a snap fastener.

6. The frequency-upgrading vibration energy harvester according to claim 1, characterized in that, The first bending spring (1) is a serpentine bending beam spring, and each connecting piece (2) connects three serpentine bending beam springs.

7. The frequency-upgrading vibration energy harvester according to claim 1, characterized in that, The second bending spring (9) is a straight bending beam spring.

8. The frequency-upgrading vibration energy harvester according to claim 1, characterized in that, The coil frame (4) also includes a central support plane (10). There are two coil supports. The central support plane (10) is located between the two coil supports. A second bending spring (9) is provided between any coil support and the central support plane (10). The two coil supports and the central support plane are located between the two upper support planes.

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