Toggle type up-conversion arm swing piezoelectric energy collection device

Abstract

The invention discloses a toggle type up-conversion arm swing piezoelectric energy collection device, and belongs to the field of human body motion energy collection. The invention aims to solve the problem that the low human body motion frequency is not matched with the frequency that a piezoelectric cantilever beam can only obtain ideal output in a high-frequency range. One end of the piezoelectric cantilever beam is fixed to the arm base through a clamping plate, a bolt and a nut, the plectrum can rotate around a bearing on the arm base through shaft key fit, and a balancing weight on the plectrum and an elastic rope connected with the balancing weight can adjust the initial displacement of the tail end of the piezoelectric cantilever beam after the tail end of the piezoelectric cantilever beam is plectured. When the arm swings, the plectrum swings along with the arm and pokes the tail end of the piezoelectric cantilever beam to enable the piezoelectric cantilever beam to deform, and the piezoelectric patch pasted on the beam converts mechanical energy into electric energy under the action of stress and transmits the electric energy to electricity storage equipment through the wire. The piezoelectric cantilever beam is shifted to vibrate near the inherent frequency, so that high output is obtained, and the energy collector has the advantages of being novel in structure, flexible in design, simple in excitation mode and the like, and can be widely applied to energy collection in the fields of human motion such as running and walking race.

Description

Technical field

[0001] The present invention relates to a piezoelectric energy collection device, in particular to a toggle-type up-conversion arm swing piezoelectric energy collection device, belonging to the technical field of human motion energy collection. Background Art

[0002] With the rapid development of low-power electronic technologies such as the Internet of Things, wireless sensor networks, and smart wearable devices, the demand for stable and reliable energy supply is increasing. However, traditional chemical batteries suffer from limited lifespans, environmental pollution, and inconvenient replacement and maintenance, making them unable to meet the long-term, miniaturized, and environmentally friendly power supply requirements of these devices. Therefore, the search for new and sustainable energy supply methods has become a critical issue that needs to be addressed. Against this backdrop, piezoelectric energy harvesting has emerged as an emerging green energy solution. This technology utilizes the voltage signal generated by piezoelectric materials in response to external vibration or pressure to convert mechanical energy into electrical energy. With significant advantages such as simple structure, high energy density, ease of miniaturization, and no environmental pollution, it has become a research hotspot in the field of vibration energy harvesting. Notably, the vibration energy generated during human movement is renewable. Using piezoelectric energy harvesting technology to capture and convert human vibration energy to provide continuous power for wearable devices overcomes the limitations of traditional batteries while aligning with the trends of miniaturization and green development of electronic devices, making it a highly promising energy solution.

[0003] However, most current piezoelectric energy harvesting devices operate at a high frequency. Due to the limitations of the size of the piezoelectric vibrator structure, they can usually only effectively harvest energy near its resonant frequency. For example, in studies such as "Qi X, Ma C, Wang D. High-Performance Spiral Piezoelectric Energy Harvester With Wraparound Proof Mass [J]. IEEE Sensors Journal, 2023, 23(20): 24346-54." and "Ma C, Yang X, Wang DA Novel Semiircular Annular Piezoelectric Energy Harvester [J]. IEEE Sensors Journal, 2024, 24(8): 12122-30.", the operating frequency of the energy harvesting device is above 50 Hz, which is much higher than the frequency of human motion. This limits its application in the field of human motion.

[0004] Secondly, in order to make up for the disadvantage of the high operating frequency of piezoelectric energy harvesting devices, current research mostly uses frequency reduction technology. However, existing frequency reduction methods are difficult to reduce the operating frequency of the device to the human body movement frequency range (for example, the swing frequency is about 1-3Hz), and the output power of these frequency reduction schemes is generally low, generally maintained at the μW level. For example, the literature "He L, Kurita H, Narita F. Multimode auxetic piezoelectric energy harvester for low-frequency vibration[J]. Smart Materials and Structures, 2024, 33(3)." and "Lin S, Zhang Z, Zhai S, et al. Construction and Performance Evaluation of a Pendulum-Like Low-Frequency Smoothly Plucked Piezoelectric Vibration Energy Harvester[J]. IEEE / ASME Transactions on Mechatronics, 2025: 1-11.", etc., which makes it difficult for existing frequency reduction technology to meet the power requirements of low-power sensors and other devices.

[0005] Currently, most piezoelectric energy harvesting devices are not optimized for specific application scenarios and have only been improved in various functional indicators. For example, the piezoelectric energy harvesting device designed in the literature "JIANG W, WANG L, ZHAO L, et al. Modeling and design of V-shaped piezoelectric vibration energy harvester with stopper for low-frequency broadband and shock excitation [J]. Sensors and Actuators A: Physical, 2021, 317" cannot be directly applied to human motion and does not take into account the issue of human compatibility, which greatly limits the device's application prospects in actual human motion energy harvesting. Summary of the Invention

[0006] The purpose of the present invention is to provide a toggle-type up-conversion arm swing piezoelectric energy harvesting device to solve the problem that the traditional piezoelectric energy harvesting device has a high resonant frequency, does not match the human body movement frequency, and cannot be directly applied to human body movement.

[0007] A toggle-type up-conversion arm pendulum piezoelectric energy harvesting device comprises an arm seat, an arm pendulum, a counterweight, an elastic rope, a clamping plate (L-shaped clamping plate and rectangular clamping plate), a piezoelectric cantilever beam, and a shaft assembly;

[0008] The arm pendulum is installed on the arm base through shaft system components such as C-shaped flat keys and stepped shafts, and the counterweight is placed in the counterweight mounting slot on the arm pendulum; one end of the elastic rope is connected to the elastic rope connecting bolt on the arm base, and the other end passes through the arm pendulum limit hole; the piezoelectric cantilever beam is installed on the arm base through screws, nuts and splints.

[0009] Preferably: one side of the arm seat has an arc-shaped groove adapted to the shape of the human forearm to enhance its adaptability to the human body; the upper part of the other side is provided with a bearing hole slightly larger than the outer diameter of the bearing, and four blind holes of the same size are provided around the bearing hole. The bearing is installed in the bearing hole of the arm seat, and the bolt is fixed to the arm seat through the through hole of the bearing cover and the blind hole to prevent axial movement of the bearing.

[0010] Preferably: the shaft is designed as a stepped shaft with thinner sides and thicker middle. The lower end of the shaft is connected to the bearing through an interference fit, and a keyway is provided at the upper end, which is connected to the arm pendulum through a C-shaped flat key to realize the swing of the arm pendulum around the shaft; at the same time, a threaded hole is provided at the upper end of the shaft, and a locking screw cooperates with the threaded hole to prevent the flat key from moving in the axial direction.

[0011] Preferably: the piezoelectric cantilever beam includes a piezoelectric sheet and a metal elastic matrix, wherein the width of the piezoelectric sheet is slightly smaller than the width of the elastic matrix, and the piezoelectric sheet is adhered to the part of the elastic matrix close to the fixed end by epoxy resin conductive glue; the fixed end of the piezoelectric beam is provided with four through holes that match the splint, which are connected to the L-shaped splint and the rectangular splint by bolts and nuts, and then screws are passed through the through holes of the L-shaped splint to match the splint mounting blind holes on the arm seat to achieve the fixation of the piezoelectric cantilever beam.

[0012] Preferably, the end of the arm swing is designed with a plectrum for making the piezoelectric cantilever beam vibrate. When the arm swings, the front end of the plectrum contacts the end of the piezoelectric cantilever beam, thereby making the piezoelectric beam vibrate. The piezoelectric piece is subjected to stress changes and converts mechanical energy into electrical energy which is output through the wire.

[0013] Preferably: a counterweight mounting slot is provided on the arm pendulum, and the mass of the arm pendulum is adjusted by adjusting the counterweight, thereby adjusting the deformation amplitude of the piezoelectric cantilever beam after being toggled; one end of the elastic rope is fixed to the connecting bolt at the end of the arm seat, and the other end passes through the limiting hole on the arm pendulum to limit the movement of the arm pendulum, which can prevent it from continuously rotating due to inertia and getting out of control, thereby ensuring that the arm pendulum swings left and right only within the set range, and at the same time avoiding excessive deformation of the piezoelectric beam after being toggled, which in turn causes the piezoelectric sheet to break.

[0014] Compared with existing products, the present invention has the following effects:

[0015] 1. A toggle-type up-conversion arm-swing piezoelectric energy harvester converts the kinetic energy of a person's arm swing into electrical energy by toggling a piezoelectric cantilever beam. The piezoelectric beam vibrates at its natural frequency when toggled, achieving efficient energy harvesting. This energy harvester utilizes up-conversion technology, breaking through the limitations of human motion frequency. It boasts a novel structure and high adaptability to human motion.

[0016] 2. The arm of the present invention is provided with a groove for installing a counterweight. By adjusting the mass of the counterweight, the inertia of the arm during swinging can be effectively changed, thereby adjusting the degree of deformation of the piezoelectric cantilever beam after being toggled. The piezoelectric energy harvesting device has the advantages of flexible design and high adjustability.

[0017] 3. The present invention is designed with a safety protection device. The elastic rope between the arm swing and the arm seat can effectively limit the continuous rotation and loss of control of the arm swing due to excessive inertia, and at the same time prevent the plectrum on the arm swing from colliding violently with the piezoelectric beam due to inertia, which may cause excessive deformation of the piezoelectric beam and breakage of the piezoelectric sheet. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural diagram of a toggle-type up-conversion arm swing piezoelectric energy harvesting device;

[0019] Figure 2 This is an exploded diagram of the arm base connection part;

[0020] Figure 3 This is an exploded diagram of the piezoelectric beam connection part;

[0021] Figure 4 It is a schematic diagram of the working principle of a toggle-type up-conversion arm swing piezoelectric energy harvesting device;

[0022] In the figure: 1-arm seat, 2-bearing cover, 3-locking screw, 4-arm swing, 5-piezoelectric piece, 6-piezoelectric cantilever beam, 7-counterweight, 8-elastic rope, 9-cover mounting blind hole, 10-bearing hole, 11-bearing, 12-C-type flat key, 13-stepped shaft, 14-keyway hole, 15-arm swing limit hole, 16-counterweight mounting slot, 17-plectrum, 18-elastic rope connecting bolt, 19-L-shaped splint, 20-splint mounting blind hole, 21-rectangular splint. DETAILED DESCRIPTION

[0023] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0024] like Figures 1 to 3 As shown, the toggle-type up-conversion arm pendulum piezoelectric energy harvesting device of the present invention includes an arm base 1, an arm pendulum 4, a counterweight 7, an elastic rope 8, a clamping plate (L-shaped clamping plate 19 and a rectangular clamping plate 21), a piezoelectric cantilever beam 6, and a shaft assembly;

[0025] The specific shaft system components include: a bearing cover 2, a locking screw 3, a bearing 10, a C-type flat key 12 and a stepped shaft 13; its connection structure is as follows: the arm pendulum 4 is installed on the arm seat 1 through the C-type flat key 12, the stepped shaft 13 and other shaft system components, the counterweight 7 is placed in the counterweight mounting groove 16 on the arm pendulum 4, one end of the elastic rope 8 is connected to the elastic rope connecting bolt 18 on the arm seat 1, and the other end passes through the arm pendulum limit hole 15, and the piezoelectric cantilever beam 6 is installed on the arm seat 1 through screws, nuts and splints.

[0026] Further: one side of the arm seat 1 has an arc-shaped groove adapted to the shape of the human forearm to enhance its adaptability to the human body; the upper part of the other side is provided with a bearing hole 10 slightly larger than the outer diameter of the bearing, and four identical-sized pressure cover mounting blind holes 9 are provided around the bearing hole 10. The bearing 11 is installed in the bearing hole 10 of the arm seat 1, and the bolts pass through the through holes of the bearing pressure cover 2 and the pressure cover mounting blind holes 9 to fix it on the arm seat 1, thereby preventing axial movement of the bearing 11.

[0027] Further: the shaft is designed as a stepped shaft 13 that is thinner on both sides and thicker in the middle. The lower end of the stepped shaft 13 is connected to the bearing 11 through an interference fit, and a keyway is provided at the upper end, which is connected to the arm pendulum 4 through a C-shaped flat key 12 to realize the swing of the arm pendulum 4 around the stepped shaft 13; at the same time, a threaded hole is provided at the upper end of the stepped shaft 13, and the locking screw 3 cooperates with the threaded hole to prevent the C-shaped flat key 12 from moving in the axial direction.

[0028] Further: the piezoelectric cantilever beam 6 includes a piezoelectric sheet 5 and a metal elastic matrix, wherein the width of the piezoelectric sheet 5 is slightly smaller than the width of the elastic matrix, and the piezoelectric sheet 5 is adhered to the part of the elastic matrix near the fixed end by epoxy resin conductive glue; the fixed end of the piezoelectric cantilever beam 6 is provided with four through holes that cooperate with the splint, which are connected to the L-shaped splint 19 and the rectangular splint 21 by bolts and nuts, and then screws are passed through the through holes of the L-shaped splint 21 to cooperate with the splint mounting blind hole 20 on the arm seat to realize the fixation of the piezoelectric cantilever beam 6.

[0029] Further: the end of the arm pendulum 4 is designed with a plectrum 17 for making the piezoelectric cantilever beam 6 vibrate. When the arm pendulum 4 swings, the front end of the plectrum 17 contacts the end of the piezoelectric cantilever beam 6, thereby making the piezoelectric cantilever beam 6 vibrate. The piezoelectric sheet 5 is subjected to stress changes and converts mechanical energy into electrical energy and outputs it through the wire.

[0030] Furthermore: a counterweight mounting slot 16 is provided on the arm pendulum 4, and the mass of the arm pendulum 4 is adjusted by adjusting the counterweight 7, thereby adjusting the deformation amplitude of the piezoelectric cantilever beam 6 after being shifted; one end of the elastic rope 8 is fixed to the connecting bolt 18 at the end of the arm seat 1, and the other end passes through the limiting hole 15 on the arm pendulum to limit the movement of the arm pendulum 4, which can prevent it from continuously rotating due to inertia and getting out of control, thereby ensuring that the arm pendulum 4 only swings left and right within the set range, and at the same time avoiding excessive deformation of the piezoelectric cantilever beam 6 after being shifted, thereby causing the piezoelectric sheet 5 to break.

[0031] further: Figure 4 The diagram below is a schematic diagram of the working principle of the present invention. When the device is stationary, the arm pendulum 4 and the piezoelectric cantilever beam 6 are not in contact with each other, and the piezoelectric cantilever beam 6 does not deform. When movement occurs, the arm pendulum 4 begins to swing, and the device enters the toggle state. The piezoelectric cantilever beam 6 continues to deform toward one side under the continuous contact of the toggle 17, and the piezoelectric plate 5 begins to generate electricity under the action of stress. The arm pendulum 4 continues to swing toward one side, and the toggle 17 contacts the edge of the end of the piezoelectric cantilever beam 6. At this time, the device is in a critical state, and the deformation of the piezoelectric cantilever beam 6 reaches its maximum. The toggle 17 then separates from the piezoelectric cantilever beam 6, and the device enters a vibrating state. At this time, the arm pendulum 4 begins to swing back under the action of the elastic rope 8, and the piezoelectric cantilever beam 6 vibrates at its natural frequency to generate electricity.

[0032] This embodiment is only an illustrative description of this patent and does not limit its scope of protection. Those skilled in the art may also make partial changes to it, but they do not exceed the spirit of this patent and are all within the scope of protection of this patent.

Claims

1. A toggle-type up-conversion arm swing piezoelectric energy harvesting device, characterized by: An arm base (1), an arm swing (4), a counterweight (7), an elastic rope (8), a splint (L-shaped splint 19 and a rectangular splint 21), a piezoelectric cantilever beam (6), and an axis system component: a bearing cover (2), a locking screw (3), a bearing (10), a C-shaped flat key (12), and a stepped shaft (13); the arm swing (4) is mounted on the arm base (1) through the C-shaped flat key (12), the stepped shaft (13), and other axis system components; the counterweight (7) is placed in the counterweight mounting groove (16) on the arm swing (4); one end of the elastic rope (8) is connected to the elastic rope connecting bolt (18) on the arm base (1), and the other end passes through the arm swing limiting hole (15); and the piezoelectric cantilever beam (6) is mounted on the arm base (1) through screws and nuts and the splint.

2. The toggle-type up-conversion arm swing piezoelectric energy collection device according to claim 1, characterized in that: One side of the arm seat (1) is provided with an arc-shaped groove adapted to the shape of a human forearm to enhance its adaptability to the human body; the upper portion of the other side is provided with a bearing hole (10) slightly larger than the outer diameter of the bearing, and four pressure cover mounting blind holes (9) of the same size are provided around the bearing hole (10). The bearing (11) is mounted in the bearing hole (10) of the arm seat (1), and bolts are fixed to the arm seat (1) by passing through the through hole of the bearing pressure cover (2) and the pressure cover mounting blind holes (9), thereby preventing the bearing (11) from axial movement.

3. The toggle-type up-conversion arm swing piezoelectric energy harvesting device according to claim 1, characterized in that: The shaft is designed as a stepped shaft (13) with thinner sides and thicker middle. The lower end of the stepped shaft (13) is connected to the bearing (11) through interference fit, and the upper end is provided with a keyway, which is connected to the arm swing (4) through a C-shaped flat key (12) to achieve the swing of the arm swing (4) around the stepped shaft (13); at the same time, the upper end of the stepped shaft (13) is provided with a threaded hole, and the locking screw (3) cooperates with the threaded hole to prevent the C-shaped flat key (12) from moving in the axial direction.

4. The toggle-type up-conversion arm swing piezoelectric energy harvesting device according to claim 1, characterized in that: The piezoelectric cantilever beam (6) comprises a piezoelectric sheet (5) and a metal elastic matrix, wherein the width of the piezoelectric sheet (5) is slightly smaller than the width of the elastic matrix, and the piezoelectric sheet (5) is adhered to the portion of the elastic matrix near the fixed end by epoxy resin conductive adhesive; the fixed end of the piezoelectric cantilever beam (6) is provided with four through holes matched with the clamping plate, and is connected to the L-shaped clamping plate (19) and the rectangular clamping plate (21) by bolts and nuts, and then screws are passed through the through holes of the L-shaped clamping plate (21) and matched with the clamping plate mounting blind hole (20) on the arm seat to achieve the fixation of the piezoelectric cantilever beam (6); the end of the arm swing (4) is designed with a plectrum (17) for stirring the piezoelectric cantilever beam (6) to vibrate, and when the arm swing (4) swings, the front end of the plectrum (17) contacts the end of the piezoelectric cantilever beam (6), thereby stirring the piezoelectric cantilever beam (6) to vibrate, and the piezoelectric sheet (5) is subjected to stress changes to convert mechanical energy into electrical energy and output it through the wire.

5. The toggle-type up-conversion arm swing piezoelectric energy harvesting device according to claim 1, characterized in that: The arm pendulum (4) is provided with a counterweight installation slot (16), and the mass of the arm pendulum (4) is adjusted by adjusting the counterweight (7), thereby adjusting the deformation amplitude of the piezoelectric cantilever beam (6) after being toggled; one end of the elastic rope (8) is fixed to the connecting bolt (18) at the end of the arm seat (1), and the other end passes through the limiting hole (15) on the arm pendulum to limit the movement of the arm pendulum (4), thereby preventing it from continuously rotating due to inertia and getting out of control, thereby ensuring that the arm pendulum (4) only swings left and right within a set range, and at the same time preventing the piezoelectric cantilever beam (6) from being deformed too much after being toggled, thereby causing the piezoelectric sheet (5) to break.

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