A heel power generation device and a design method thereof for powering a wearable device

Abstract

This invention discloses a shoe heel power generation device that can power wearable devices. It includes a base plate in contact with the ground and an upper plate adhered to the upper surface of the base plate and to the sole of the shoe. The upper plate has a mounting groove and a square deformation groove. A cuboid support block is provided on the bottom surface of the square deformation groove. The mounting groove is adhered to the root of a piezoelectric cantilever beam. The deformable end of the piezoelectric cantilever beam is located below the square deformation groove. A limit block is provided on the deformable end of the piezoelectric cantilever beam, penetrating and slidably disposed within a sliding through hole. Pressing the limit block causes the piezoelectric cantilever beam to deform. A circuit board placement groove is provided on the surface of the base plate in contact with the upper plate, and an energy storage circuit board connected to the piezoelectric cantilever beam is disposed within the circuit board placement groove. A cuboid support block is placed at a designated position below the piezoelectric cantilever beam, thereby ensuring that the piezoelectric beam generates the same stress along its entire length from root to top as at the root during deformation, thus increasing the output voltage of the piezoelectric cantilever beam.

Description

Technical Field

[0001] This invention relates to the field of heel power generation technology, and in particular to a heel power generation device that can power wearable devices and its design method. Background Technology

[0002] With the continuous advancement of technology, wearable devices are increasingly being widely used, ranging from smartwatches, smart bracelets, and smart glasses to wearable health monitoring devices such as heart rate sensors, blood pressure sensors, and blood glucose sensors. In the future, with further technological development, wearable electronic products and health monitoring devices will become an indispensable part of daily life. A key challenge is how to power these smart wearable devices and keep them running for extended periods. Besides repeatedly charging or replacing batteries, technologies that utilize human kinetic energy to generate electricity and power wearable devices are receiving increasing attention. Specific methods include harvesting kinetic energy from wrist movements, knee flexion, and walking.

[0003] Currently, there are many power generation devices installed on shoe soles, which can be mainly categorized into those based on electromagnetic induction and those based on piezoelectricity. Power generation devices based on electromagnetic induction suffer from drawbacks such as complex structural design, large size, and heavy weight. Among piezoelectric methods, the most typical utilizes the piezoelectric effect of a cantilever piezoelectric beam to generate electricity. Although its structural design is simple and lightweight, it suffers from low power generation efficiency.

[0004] As is well known, the power generation efficiency of piezoelectric materials is directly proportional to the stress distribution of the material. Therefore, within the strength limit of the piezoelectric material, maximizing the stress distribution can improve its power generation efficiency. Among many power generation devices based on piezoelectric materials, piezoelectric cantilever beams are widely used due to their simple structure. However, during deformation, the stress at the root of the piezoelectric cantilever beam is the highest, decreasing linearly along the beam's length until the stress at the top is zero. Consequently, the stress is very low over a large area near the top of the piezoelectric cantilever beam, resulting in very weak electrical energy generated near the top. This means the entire length of the piezoelectric beam is not fully utilized, leading to a decrease in the cantilever beam's power generation efficiency and a low output voltage. Summary of the Invention

[0005] To address the problem that existing shoe sole power generation technologies use piezoelectric cantilever beams, where stress is very low over a large area near the top of the piezoelectric cantilever beam, resulting in very weak electrical energy generated near the top of the beam and underutilization of its entire length, leading to reduced power generation efficiency and low output voltage, this invention provides a shoe heel power generation device and its design method that can improve the power generation efficiency of piezoelectric beams, thereby providing power for wearable devices.

[0006] The technical solution of this invention is as follows: a shoe heel power generation device that can power wearable devices, comprising a base plate in contact with the ground, and an upper plate adhered to the upper surface of the base plate and to the sole of the shoe. The upper plate has an installation groove and a square deformation groove. A cuboid support block is provided on the bottom surface of the square deformation groove. The length of the cuboid support block is equal to the width of the square deformation groove. The width of the cuboid support block is 2mm to 8mm. The height of the cuboid support block is determined by a support block height design method. The cuboid support block ensures the piezoelectric cantilever beam deforms... The piezoelectric beam generates uniform stress along its entire length, thereby increasing its output voltage. The mounting groove is bonded to the root of the piezoelectric cantilever beam. The deformable end of the piezoelectric cantilever beam is located below the square deformation groove. A limiting block is provided at the top of the deformable end of the piezoelectric cantilever beam. A sliding through hole is provided on the base plate. The limiting block passes through and slides within the sliding through hole. The limiting block deforms the piezoelectric cantilever beam by being pressed. A circuit board placement groove is provided on the surface of the base plate that contacts the upper plate. An energy storage circuit board connected to the piezoelectric cantilever beam is placed in the circuit board placement groove.

[0007] As a further improvement to the above technical solution:

[0008] Preferably, the mounting groove and the square deformation groove are stepped, and the depth of the mounting groove is equal to the height of the piezoelectric cantilever beam.

[0009] Preferably, the limiting block is made of soft rubber.

[0010] Preferably, a leather isolation layer is provided at the bottom of the base plate, and the leather isolation layer is wrapped around the outside of the limiting block.

[0011] Preferably, the piezoelectric cantilever beam consists of a base layer and piezoelectric layers disposed on the upper and lower end faces of the base layer, the limiting block is disposed on the upper end of one of the piezoelectric layers, and the two piezoelectric layers are connected in parallel.

[0012] Preferably, the piezoelectric cantilever beam and the surface of the energy storage circuit board are coated with waterproof adhesive.

[0013] Preferably, the height design method for the cuboid support block is as follows:

[0014] Step 1: Determine the distance L from the cuboid support block to the root of the piezoelectric cantilever beam. a ;

[0015] Step 1, according to L a And by formula Obtain the distance u between the lower end face of the piezoelectric cantilever beam and the upper end face of the support block. a ;

[0016] Step 3, according to u aCalculate the height h of the cuboid support block. a h a =hu a ;

[0017] In the above formula, L a L is the distance from the end face of the cuboid support block to the root of the piezoelectric cantilever beam. p Let u be the length of the piezoelectric cantilever beam. e u represents the deformation displacement at the end of the piezoelectric cantilever beam. a h is the height of the upper surface of the cuboid support block from directly below the piezoelectric cantilever beam. a denoted as the height of the cuboid support block, and h as the distance from the bottom surface of the piezoelectric cantilever beam to the bottom surface of the square deformation groove.

[0018] Preferably, the height of the cuboid support block is obtained using the aforementioned cuboid support block height design method, then the stress of the piezoelectric cantilever beam is:

[0019]

[0020] in Y P h is the elastic modulus of the piezoelectric layer. s h is the thickness of the base layer. p The thickness is the piezoelectric layer thickness.

[0021] A design method for a shoe heel power generation device capable of powering wearable devices includes the following steps:

[0022] Step 1: Determine the outline dimensions of the upper plate and the sole plate according to the heel size; the thickness is determined based on the material.

[0023] Step 2: Determine the dimensions of the piezoelectric cantilever beam. The dimensions of the piezoelectric cantilever beam can be used to determine the dimensions of the mounting groove on the upper plate and the dimensions of the slot and the rectangular groove on the bottom plate.

[0024] Step 3: Select the piezoelectric material for the piezoelectric cantilever beam, determine its design stress based on the yield strength of the piezoelectric material, and then determine Lp, La, and u. e parameter;

[0025] Step 4: Set a cuboid support block on the bottom surface of the square deformation groove of the upper plate. The length La of the cuboid support block is less than the length Lp of the cantilever beam. The length of the cuboid support block is determined by the width of the square deformation groove of the upper plate and is equal to the width of the square deformation groove. The width of the cuboid support block is selected from 2mm to 8mm depending on the material. The height of the cuboid support block is obtained through the cuboid support block height design method.

[0026] Step 5: Assembly. Attach the energy storage circuit board to the circuit board placement groove on the base plate, attach the root of the piezoelectric cantilever beam to the mounting groove, connect the piezoelectric cantilever beam to the energy storage circuit board, then use strong waterproof adhesive to attach the base plate to the top plate, and finally attach the top plate to the heel to complete the assembly.

[0027] As a further improvement to the above technical solution:

[0028] Preferably, in Step 2, the length of the piezoelectric cantilever beam is 0.7 to 0.9 times the maximum length of the upper plate, and the width of the piezoelectric cantilever beam is 0.7 to 0.9 times the maximum width of the upper plate.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. The piezoelectric cantilever beam heel power generation device provided by the present invention can be used to generate electricity, converting the kinetic energy of human walking into electrical energy to power wearable devices such as smart bracelets and health monitoring sensors; it can also be used as a shoe heel without adding extra size to the shoe; secondly, a cuboid support block is set at a designated position below the piezoelectric cantilever beam, the height of which is determined by the height design method of the cuboid support block, so that when the piezoelectric cantilever beam deforms, the piezoelectric beam generates the same stress as at the root along its entire length from the root to the top, making full use of the entire cantilever beam to generate electricity, and ultimately improving the output voltage of the piezoelectric beam and its power generation efficiency.

[0031] 2. The present invention applies a layer of waterproof adhesive to the surface of the energy storage circuit and the piezoelectric beam to prevent water from entering the interior and causing a short circuit. At the same time, a leather isolation layer covering the limiting block is provided on the base plate to prevent dust or fine sand from entering the interior through the gap between the limiting block and the sliding through hole of the base plate and causing damage to the piezoelectric cantilever beam and the energy storage circuit board. It also increases the design sense of the base plate and enhances its aesthetics.

[0032] 3. The shoe heel power generation device provided by the present invention has a simple structure, is small in size and light in weight, does not affect the original wearing feel of the shoe, and has a high output voltage. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the overall three-dimensional exploded structure of the present invention;

[0034] Figure 2 This is a schematic diagram of the overall three-dimensional structure of the present invention;

[0035] Figure 3 This is a three-dimensional structural diagram of the upper plate of the present invention;

[0036] Figure 4 This is a three-dimensional cross-sectional view of the base plate of the present invention;

[0037] Figure 5 This is a schematic diagram of the three-dimensional structure of the piezoelectric cantilever beam of the present invention;

[0038] Figure 6 This is a schematic diagram of the three-dimensional structure of the limiting block of the present invention;

[0039] Figure 7 This is a schematic diagram of the bonding structure between the limiting block and the piezoelectric cantilever beam of the present invention.

[0040] Figure 8 This is a schematic diagram of the bonding structure between the piezoelectric cantilever beam and the base plate of the present invention.

[0041] Figure 9 This is a side view structural schematic diagram of the present invention;

[0042] Figure 10 This is a schematic diagram of the deformation of the piezoelectric cantilever beam of the present invention;

[0043] Figure 11 This is a schematic diagram of the stress curve of the piezoelectric cantilever beam of the present invention;

[0044] Figure 12 This is a schematic diagram showing the arrangement of the pressure support blocks according to the present invention;

[0045] Figure 13 This is a schematic diagram comparing the stress curve of the piezoelectric cantilever beam of the present invention with the stress curve of the design;

[0046] Figure 14 This is a schematic diagram of the prototype of the shoe heel power generation device of the present invention;

[0047] Figure 15 This is a schematic diagram comparing the charging efficiency of the conventional piezoelectric cantilever beam of the present invention with that of the present solution.

[0048] Reference numerals: 1. Base plate; 2. Top plate; 3. Mounting groove; 4. Square deformation groove; 5. Rectangular support block; 6. Piezoelectric cantilever beam; 61. Base layer; 62. Piezoelectric layer; 7. Limiting block; 8. Sliding through hole; 9. Circuit board placement groove; 10. Energy storage circuit board; 11. Cortical isolation layer. Detailed Implementation

[0049] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0050] In the description of this invention, it should be understood that the terms "front," "rear," "left," "right," "up," and "down," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. The technical solutions of the various embodiments in this invention can be combined, and the technical features in the embodiments can also be combined to form new technical solutions.

[0051] This invention provides the following technical solution:

[0052] Example 1

[0053] The main structural features of this technical solution are described in the appendix. Figure 1 With appendix Figure 2 As shown, the technical solution of the present invention mainly includes six parts: 1. a base plate 1, which is in contact with the ground; 2. a limiting block 7; 3. a piezoelectric cantilever beam 6; 4. an upper plate 2, which is connected to the sole of the shoe; 5. a cuboid support block 5; and 6. an energy storage circuit board 10.

[0054] As attached Figure 3 The diagram shown is a schematic of the upper plate 2 structure. Its outline shape is designed according to the heel size (maximum width denoted as b). t The maximum length is denoted as L. t The material can be plastic or metal, etc., with a thickness of h. t The recommended range is between 8mm and 20mm, depending on the hardness of the material.

[0055] A rectangular groove is cut inside the upper plate 2. There are no specific requirements for its dimensions; they can be flexibly set according to the dimensions of the upper plate 2. It is recommended that the width of the rectangular groove be b. c Take (0.7~0.9)b t Length (L) h +L c The value is taken as (0.8~0.9)L. t Depth u e The design method is determined by the maximum stress of the piezoelectric beam and will be given later. The energy storage circuit board 10 is placed in a rectangular slot.

[0056] A cuboid support block 5, shaped like a rectangular prism, is installed inside the rectangular groove. The length of the cuboid support block 5 is l. a Same width as the rectangular slot, width b a The recommended thickness is 2mm to 8mm, depending on the material's hardness and height h. a The height of the support block is obtained through a design method, which will be explained in detail later. The position L of the support block is also discussed. aThe design stress of the piezoelectric beam can be determined. The addition of a cuboid support block 5 ensures that the cantilever beam generates the same stress along its entire length during deformation, thereby increasing the output voltage of the piezoelectric beam.

[0057] A step is provided inside the rectangular groove, dividing it into a mounting groove 3 and a square deformation groove 4. The mounting groove 3 is located above the step and is used to fix the root of the piezoelectric cantilever beam 6. The step width L h Take (0.1~0.2)L t Depth and height h of the piezoelectric cantilever beam at root 6 b The same arrangement ensures that the plane of the piezoelectric cantilever beam 6 is flush with the plane of the upper plate 2. One side of the upper plate 2 is bonded to the bottom plate 1 with strong waterproof adhesive, and the other side is bonded to the sole with strong waterproof adhesive.

[0058] Figure 4 This is a schematic diagram of the base plate 1. Its outline and size are exactly the same as the upper plate 2. The material can be plastic or metal, etc., and the thickness is h. d The recommended thickness is between 1mm and 8mm, depending on the material hardness. One side of the base plate 1 contacts the ground, and the other side is bonded to the upper plate 2 with strong adhesive. Anti-slip textures can be added to the surface in contact with the ground. A rectangular sliding through-hole 8 is cut into the base plate 1, located at the end of the piezoelectric cantilever beam 6. The length L of the sliding through-hole 8 is... r It is recommended to use (0.95~1.0)b. c Width b r A width of 10mm to 20mm is recommended. A circuit board placement slot 9 needs to be cut into the side that is bonded to the upper plate 2 to store the energy storage circuit board 10. The recommended width of the circuit board placement slot 9 is b. d Let b c Length L d Take (L) h +L c The depth is determined by the purchased energy storage circuit board 10, and it is recommended to be between 3mm and 5mm. For the energy storage circuit board 10, you can purchase a relatively mature product on the market. Two small holes with a diameter of less than 1mm can be made at the bonding surface between the upper plate 2 and the bottom plate 1 to transmit the stored electrical energy through wires. However, the holes need to be waterproof, otherwise rainwater may easily flow back in and cause a short circuit.

[0059] Figure 5 This is a schematic diagram of the piezoelectric cantilever beam 6, which consists of a base layer 61 and two piezoelectric layers 62. The base layer 61 can be made of metal or other non-metallic materials; it is recommended to use spring steel with good elasticity, with a thickness between 0.1mm and 2mm, and a length L. p Compared to L c Less than 0.5mm to 1mm, width b p Compared to b cThe thickness should be 1mm to 2mm less. The piezoelectric layer 62 should be made of a material capable of producing a piezoelectric effect, such as piezoelectric ceramics or PVDF films. The recommended thickness for piezoelectric layer 62 is 0.2mm to 1mm. The two piezoelectric layers, the base layer 61 and the piezoelectric layer 62, are connected in parallel. The root length L of the piezoelectric beam... b With L h Same, h b A thickness of 1mm to 3mm is recommended. The root of the piezoelectric cantilever beam 6 is bonded to the stepped surface of the base plate 1, i.e., within the mounting groove 3, using strong adhesive. The root length L of the piezoelectric beam is... b With L h Same. h b A thickness of 1mm to 3mm is recommended.

[0060] Figure 6 The diagram shows the structure of the limiting block 7, which is a cuboid. It is recommended to make it from slightly soft, elastic rubber. The limiting block 7 is slightly smaller than the sliding through hole 8 on the base plate 1 to ensure that the limiting block 7 can slide freely within the hole. Therefore, it is recommended that its length L be... l Compared to L r Smaller than 0.5mm to 1mm, b l Compared to b r Smaller than 0.5mm to 1mm, h l It needs to be slightly larger than the sum of the thicknesses of the upper plate 2 and the bottom plate 1.

[0061] Figure 7 This is a schematic diagram of the bonding between the limiting block 7 and the piezoelectric cantilever beam 6. The limiting block 7 is placed on the top of the piezoelectric cantilever beam 6, and deformation displacement can be applied to the cantilever beam through the limiting block 7.

[0062] Figure 8 This is a schematic diagram of the bonding between the piezoelectric cantilever beam 6 and the base plate 1. The root of the piezoelectric cantilever beam 6 is bonded to the mounting groove 3 of the base plate 1.

[0063] Figure 9 For the overall side view, a leather insulating layer 11 made of leather material is sewn or pasted onto the area near the limiting block 7 to wrap around the limiting block 7, thereby preventing dust or fine sand from entering through the gap between the limiting block 7 and the sliding through hole 8 between the limiting block 7 and the base plate 1. In addition, a layer of waterproof adhesive needs to be applied to the surface of the energy storage circuit board 10 and the piezoelectric cantilever beam 6.

[0064] Working principle of the invention:

[0065] When the heel touches the ground, the cantilever piezoelectric beam will deform under the pressure of the limit block 7. When the deformation exceeds the height of the support block, it will generate an additional support force on the cantilever beam, thereby changing the stress distribution of the cantilever beam and causing the piezoelectric cantilever beam 6 to generate uniform stress along the entire length, thereby increasing the output voltage of the piezoelectric beam.

[0066] When the heel leaves the ground, the limit block 7 pops out under the elastic restoring force of the piezoelectric cantilever beam 6, and the piezoelectric cantilever beam 6 returns to its original shape; the electrical energy generated during the deformation and recovery process of the piezoelectric cantilever beam 6 is stored by the energy storage circuit.

[0067] Example 2

[0068] The method for designing the height of the cuboid support block 5 of the upper plate 2 in Example 1, for the piezoelectric cantilever beam 6, is as follows: Figure 10 With appendix Figure 5 As shown, it comprises two piezoelectric layers 62 and a base layer 61, when a displacement u is applied to its apex... e At that time, according to the theory of mechanics of materials, the stress of the piezoelectric cantilever beam 6 can be expressed as:

[0069]

[0070] In the formula, σ(x) represents the stress distribution of the piezoelectric cantilever beam 6; Y P The elastic modulus of the piezoelectric layer 62; h s The thickness of the base layer is 61; h p The piezoelectric layer is 62mm thick; u e L represents the deformation displacement at the end of the piezoelectric cantilever beam 6. p The length of the piezoelectric cantilever beam is 6.

[0071] From the appendix Figure 11 It can be seen that the stress along the entire length of the piezoelectric cantilever beam 6 varies linearly, with the maximum stress at the root and decreasing linearly to zero at the top. Since the power generation efficiency of the piezoelectric cantilever beam 6 is proportional to its stress distribution, a large area at the top of the piezoelectric cantilever beam 6 does not participate in power generation.

[0072] To improve power generation efficiency, the present invention sets a new support point below the piezoelectric cantilever beam 6, thereby changing the stress distribution of the cantilever beam and increasing the output voltage of the piezoelectric beam.

[0073] like Figure 12 As shown, in L a A support block is applied at point U, and the top displacement of the beam is u. e The support block is at a height of u directly below the beam. a .

[0074] according to Figure 13 Based on the design stress curve and the theory of mechanics of materials, the deformation curve of the piezoelectric cantilever beam 6 can be obtained as follows:

[0075]

[0076] In the formula, u1 and u2 must satisfy the following equation:

[0077]

[0078] Therefore, the stress of piezoelectric cantilever beam 6 is:

[0079]

[0080] Therefore, if the following formula holds:

[0081]

[0082] The stress in a cantilever beam can then be expressed as:

[0083]

[0084] At this point, the stress curve of the cantilever beam with support blocks is as follows: Figure 13 As shown in the figure, from the root of the cantilever beam to L a The stress at L is constant and the same as the stress at the root. a To L p The stress at that point decreases linearly to zero. In practical design, L a It only needs to be slightly smaller than L p Therefore, it can be approximated that the stress in the cantilever beam is the same along its entire length as the stress at the root. Consequently, the stress distribution in a cantilever beam with support blocks is more uniform, and its output voltage is also higher.

[0085] From the above formula, we can see that:

[0086]

[0087] Once you obtain u a The height h of the support block can then be obtained. a

[0088] h a =hu a ;

[0089] The final stress expression for piezoelectric cantilever beam 6 is as follows:

[0090]

[0091] In practical design, it is recommended to extend the cantilever beam root to L a The stress value at the point is designed to be 0.8 to 0.9 times the yield strength of the piezoelectric material, so that the piezoelectric material can maximize the power generation of the device while meeting the fatigue strength requirements.

[0092] Example 3

[0093] Combining Embodiments 1 and 2, this is the overall design method for this technical solution, and the specific process is as follows:

[0094] 1. Determine the outline dimensions of the upper plate 2 and the bottom plate 1 based on the heel size; the thickness is determined according to the material.

[0095] 2. Determine the dimensions of the piezoelectric cantilever beam 6. The dimensions of the piezoelectric cantilever beam 6 can be used to determine the dimensions of the mounting groove 3 on the upper plate 2 and the dimensions of the slot and the rectangular groove on the bottom plate 1.

[0096] 3. Select piezoelectric material for piezoelectric cantilever beam 6, and determine its design stress based on the yield strength of the piezoelectric material for piezoelectric cantilever beam 6, thereby determining Lp, La, and u. e parameter;

[0097] 4. A cuboid support block 5 is set on the bottom surface of the square deformation groove 4 of the upper plate 2, wherein the La of the cuboid support block 5 is less than the length Lp of the cantilever beam, the length of the cuboid support block 5 is determined by the width of the square deformation groove 4 of the upper plate 2 and is equal to the width of the square deformation groove 4, the width of the cuboid support block 5 is selected from 2mm to 8mm depending on the material, and the height of the cuboid support block 5 is obtained through the cuboid support block 5 height design method.

[0098] 5. Assembly: Attach the energy storage circuit board 10 to the circuit board placement groove 9 of the base plate 1, attach the root of the piezoelectric cantilever beam 6 to the mounting groove 3, and connect the piezoelectric cantilever beam 6 to the energy storage circuit board 10. Then, use strong waterproof glue to attach the base plate 1 to the upper plate 2. Finally, attach the upper plate 2 to the heel to complete the assembly.

[0099] A prototype of a shoe heel power generation device was designed according to the method in Example 3. The dimensions were designed based on a size 42 shoe heel. The main dimensional parameters are shown in Table 1. The material used is nylon, and the prototype is as follows. Figure 14 As shown, its mass is 93g, therefore it has little impact on the weight of the shoe. The cantilever piezoelectric beam is designed with a stress of 40MPa.

[0100] Table 1 Main Dimensional Parameters of the Heel Piezoelectric Device

[0101]

[0102]

[0103] Assuming a walking stride frequency of approximately 1Hz, the output voltage of the heel-based power generation device was tested and compared with that of a traditional cantilever beam (without a support block at a preset height underneath). The comparison results are as follows. Figure 15 As shown, the design method proposed in this patent can increase the output voltage of the piezoelectric cantilever beam 6 by up to 90%.

[0104] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A shoe heel power generation device capable of powering wearable devices, characterized in that, The system includes a base plate (1) in contact with the ground and an upper plate (2) adhered to the upper surface of the base plate (1) and attached to the sole of the shoe. The upper plate (2) has an installation groove (3) and a square deformation groove (4). A cuboid support block (5) is provided on the bottom surface of the square deformation groove (4). The length of the cuboid support block (5) is equal to the width of the square deformation groove (4). The width of the cuboid support block (5) is 2mm to 8mm. The height of the cuboid support block (5) is determined by a support block height design method. The cuboid support block (5) ensures that the piezoelectric cantilever beam (6) generates the same stress along the entire length of the beam during deformation, thereby improving the performance of the piezoelectric beam. Output voltage, the mounting groove (3) is bonded to the root of the piezoelectric cantilever beam (6), the deformed end of the piezoelectric cantilever beam (6) is located below the square deformation groove (4), a limit block (7) is provided at the top of the deformed end of the piezoelectric cantilever beam (6), a sliding through hole (8) is provided on the bottom plate (1), the limit block (7) passes through and slides in the sliding through hole (8), the limit block (7) is pressed to deform the end of the piezoelectric cantilever beam (6), the surface of the bottom plate (1) that contacts the upper plate (2) is provided with a circuit board placement groove (9), and an energy storage circuit board (10) connected to the piezoelectric cantilever beam (6) is provided in the circuit board placement groove (9); The height design method for the cuboid support block (5) is as follows: Step 1: Determine the distance L from the cuboid support block (5) to the root of the piezoelectric cantilever beam (6). a ; Step 2, according to L a And by formula The distance u between the lower end face of the piezoelectric cantilever beam (6) and the upper end face of the support block is obtained. a ; Step 3, according to u a Calculate the height h of the cuboid support block (5) a h a =hu a ; In the above formula, L a L is the distance from the end face of the cuboid support block (5) to the root of the piezoelectric cantilever beam (6). p The length of the piezoelectric cantilever beam (6) is given. u is the deformation displacement at the end of the piezoelectric cantilever beam (6). a h is the height h of the upper surface of the cuboid support block (5) from directly below the piezoelectric cantilever beam (6). a h is the height of the cuboid support block (5), and h is the distance from the bottom surface of the piezoelectric cantilever beam (6) to the bottom surface of the square deformation groove (4).

2. The shoe heel power generation device for powering wearable devices according to claim 1, characterized in that, The mounting groove (3) and the square deformation groove (4) are stepped, and the depth of the mounting groove (3) is equal to the height of the piezoelectric cantilever beam (6).

3. The shoe heel power generation device for powering wearable devices according to claim 1, characterized in that, The limiting block (7) is made of soft rubber.

4. The shoe heel power generation device for powering wearable devices according to claim 1, characterized in that, The bottom of the base plate (1) is provided with a leather isolation layer (11), which is wrapped around the outside of the limiting block (7).

5. The shoe heel power generation device for powering wearable devices according to claim 1, characterized in that, The piezoelectric cantilever beam (6) is composed of a base layer (61) and piezoelectric layers (62) disposed on the upper and lower ends of the base layer (61). The limiting block (7) is disposed on the upper end of one of the piezoelectric layers (62), and the two piezoelectric layers (62) and the base layer (61) are connected in parallel.

6. The shoe heel power generation device for powering wearable devices according to claim 1, characterized in that, The piezoelectric cantilever beam (6) and the energy storage circuit board (10) are coated with waterproof adhesive.

7. The shoe heel power generation device for powering wearable devices according to claim 1, characterized in that, The height of the cuboid support block (5) is obtained using the height design method described above. Then the stress of the piezoelectric cantilever beam (6) is: when ; but ; in ; ; The elastic modulus of the piezoelectric layer (62); The thickness of the base layer (61); The thickness of the piezoelectric layer (62) is given.

8. The design method of the shoe heel power generation device for powering wearable devices according to claim 7, characterized in that, Includes the following steps: Step 1: Determine the outline dimensions of the upper plate (2) and the bottom plate (1) according to the heel size. The thickness is determined according to the material. Step 2: Determine the dimensions of the piezoelectric cantilever beam (6). The dimensions of the piezoelectric cantilever beam (6) can be used to determine the dimensions of the mounting groove (3) of the upper plate (2) and the dimensions of the groove and the rectangular groove on the bottom plate (1). Step 3: Select the piezoelectric material for the piezoelectric cantilever beam (6), determine its design stress based on the yield strength of the piezoelectric material for the piezoelectric cantilever beam (6), and then determine L. p L a , parameter; Step 4: Set a cuboid support block (5) on the bottom surface of the square deformation groove (4) of the upper plate (2), wherein the L of the cuboid support block (5) is... a Less than the length L of the cantilever beam p The length of the cuboid support block (5) is determined by the width of the square deformation groove (4) of the upper plate (2), and is equal to the width of the square deformation groove (4). The width of the cuboid support block (5) is selected from 2mm to 8mm depending on the material. The height of the cuboid support block (5) is obtained by the cuboid support block (5) height design method. Step 5: Assembly. Attach the energy storage circuit board (10) to the circuit board placement groove (9) of the base plate (1), attach the root of the piezoelectric cantilever beam (6) to the mounting groove (3), connect the piezoelectric cantilever beam (6) to the energy storage circuit board (10), and then use strong waterproof glue to attach the base plate (1) to the upper plate (2). Finally, attach the upper plate (2) to the heel to complete the assembly.

9. The design method of the shoe heel power generation device for powering wearable devices according to claim 8, characterized in that: In Step 2, the length of the piezoelectric cantilever beam (6) is 0.7 to 0.9 times the maximum length of the upper plate (2), and the width of the piezoelectric cantilever beam (6) is 0.7 to 0.9 times the maximum width of the upper plate (2).

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