Bent piezoelectric energy collector and displacement amplification method thereof
By designing a bending piezoelectric energy harvester, the lever structure and U-shaped parts are used to achieve displacement amplification under the same pressure, solving the problem of low efficiency of traditional collectors, and improving the output power and durability of the piezoelectric sheet.
Patent Information
- Application Number
- CN202410717769.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-04
- Publication Date
- 2024-12-20
AI Technical Summary
Traditional cymbal, bridge and stacked piezoelectric energy harvesters are not output efficient under the same pressure, making it difficult to generate greater displacement to increase output power.
A bending piezoelectric energy harvester is designed, using a substrate with a piezoelectric sheet and a lever assembly. Through a combined structure of the first and second semi-cylindrical arc surfaces and the U-shaped piece, the substrate is centered by the lever principle. Bending, indirectly acting on the piezoelectric sheet to achieve displacement amplification.
When a vehicle passes by, a single tire can make the collector work twice, which improves the output power, ensures the safety and durability of the piezoelectric sheet, uniformly distributes the stress, and significantly increases the curvature and output power of the piezoelectric sheet.
Smart Images
Figure CN119171773A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a collector, in particular to a bending piezoelectric energy collector and a method for amplifying displacement thereof, which is suitable for embankment slopes of various soil types and belongs to the field of road engineering. Background Art
[0002] With the continuous expansion of infrastructure such as highway network construction in my country, the energy generated by vehicles on the road is increasing, and piezoelectric harvesters have emerged. Traditional transducers have cymbal, bridge, and stacked structures, and the output efficiency of these structures is not high. Summary of the invention
[0003] The technical problem to be solved by the present invention is to provide a bending piezoelectric energy harvester and a method for amplifying displacement thereof, which can produce a larger displacement under the same pressure and improve the output power.
[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: A bending piezoelectric energy harvester comprises a substrate with a piezoelectric sheet, wherein the middle of the lower end of the substrate contacts with a first semi-cylindrical arc surface, and both ends of the substrate extend into a groove of a lower cover plate and are limited by the upper end surface of the groove; the first semi-cylinder is installed on a lever assembly, the left and right upper ends of the lever assembly contact with the upper cover plate, and the lower end of the lever assembly contacts with a second semi-cylindrical arc surface at the bottom end of the lower cover plate; the left and right upper ends of the lower cover plate are connected to the upper cover plate through springs; when the left or right end of the upper cover plate is squeezed, the lever assembly correspondingly drives the left or right end of the substrate to bend in the middle of the span with the first semi-cylinder as support.
[0005] The lever assembly includes a pad, a first U-shaped member is rotatably mounted on the left end of the pad, and a second U-shaped member is rotatably mounted on the right end of the pad. The first U-shaped member and the second U-shaped member have the same structure and are both U-shaped.
[0006] The lower end surfaces of the horizontal parts of the first U-shaped member and the second U-shaped member contact the upper end surface of the substrate, and the relatively inner side surfaces of the vertical parts of the first U-shaped member and the second U-shaped member contact the front and rear side surfaces of the substrate.
[0007] The distance between the base plate and the lower end surface of the groove is not greater than the distance between the upper cover plate and the upper end surface of the lower cover plate.
[0008] The first semi-cylinder is located at the middle position of the upper end of the pad, and the second semi-cylinder is located at the lower end of the pad, deviating from the middle position.
[0009] The substrate is made of stainless steel, and the piezoelectric piece is made of PZT-PZNM ceramic material.
[0010] The upper cover plate, the lower cover plate, the first semi-cylinder, the second semi-cylinder, the pad, the first U-shaped piece and the second U-shaped piece are all made of nylon material.
[0011] The lower cover plate is fixed with side cover plates at the front and rear.
[0012] A method for amplifying displacement of a bending piezoelectric energy harvester comprises the following steps: Step 1), first, the piezoelectric sheet is attached to the substrate through a process; Step 2), then, the first U-shaped member, the second U-shaped member and the backing plate are installed as a whole, and the first U-shaped member and the second U-shaped member can rotate relative to the backing plate; Step 3), the substrate passes through the first U-shaped member and the second U-shaped member, and the middle of the lower end surface of the substrate contacts the first semi-cylinder; at the same time, the upper end surface of the substrate is in close contact with the lower end surfaces of the horizontal parts of the first U-shaped member and the second U-shaped member; the inner side surfaces of the vertical parts of the first U-shaped member and the second U-shaped member are in close contact with the front and rear side surfaces of the substrate; Step 4), assemble and fix the two vertical side plates of the lower cover plate and the horizontal plate at the bottom, so that the two ends of the base plate are inserted into the groove, the base plate contacts the upper end surface of the groove and maintains a certain distance from the lower end surface of the groove; the pad contacts the second semi-cylinder on the lower cover plate; the two vertical side plates of the lower cover plate and the upper cover plate at the upper end form a whole through the spring; Step 5), the lower cover plate is fixed front and back by the side cover plate, and the upper cover plate can rise and fall and be guided by the front and back limit of the side cover plate; Step 6), install the device in the road surface groove and lay asphalt for compaction; Step 7), when the vehicle travels from left to right, the left end of the device is subjected to force, and the left end of the upper cover plate moves downward, thereby driving the first U-shaped member to move downward, and the downward movement of the first U-shaped member drives the left end of the pad to move downward; when the left end of the pad moves downward, the right end of the pad moves upward at the same time, and the second U-shaped member also has a slight upward displacement due to the action of the spring; Step 8), since both ends of the substrate are inserted into the groove, when no force is applied, the upper end surface of the substrate contacts the upper end surface of the groove, and the front and rear side surfaces of the substrate contact the front and rear side surfaces of the groove. Therefore, when step 7) occurs, the right end of the substrate is fixed and the left end moves downward; the first semi-cylinder as a support has a slight upward displacement, which causes the substrate to drive the middle part of the piezoelectric sheet to bend; Step 9), after passing the first stage and entering the second stage, the tire presses over the right end of the upper cover plate, and the right end of the upper cover plate moves downward, thereby driving the second U-shaped member to move downward, and the second U-shaped member drives the right end of the pad to move downward; the left end of the pad moves upward at the same time, and the first U-shaped member also moves slightly upward due to the action of the spring; Step 10), when step 9) occurs, the right end of the substrate moves downward, and the left end of the substrate is limited by the upper end surface of the groove and remains stationary. The substrate has a slight downward displacement in the span, which can be ignored. The right end of the substrate moves downward due to the tire pressure, so the substrate also bends in the mid-span at this time, thereby driving the piezoelectric ceramics on the substrate to bend in the mid-span, and this cycle continues.
[0013] The present invention provides a bending piezoelectric energy harvester and a method for amplifying displacement thereof, which has the following technical effects: 1) When a vehicle passes by, a single tire can work twice, which greatly improves the output power compared to working once before optimization.
[0014] 2) With the improved structure, when a vehicle passes by, the pressure does not act directly on the piezoelectric sheet, but indirectly acts on the piezoelectric sheet through the first U-shaped piece and the second U-shaped piece using the lever principle. This greatly ensures the safety of the piezoelectric sheet and improves the durability of the piezoelectric sheet.
[0015] 3) The existing collector is fixed at one end and displaced by force at the other end. Through ABAQUS finite element analysis, the cantilever structure with one end fixed has stress mostly concentrated on the free end and fixed end of the cantilever structure (piezoelectric sheet attached to the stainless steel substrate), while the free end and fixed end of the cantilever structure do not have fixed piezoelectric sheet (limited by existing installation technology), which may cause stress concentration not on the piezoelectric sheet; in addition, although both the stainless steel substrate and the piezoelectric sheet will be displaced, the stiffness of the stainless steel substrate in the above cantilever structure will also weaken the displacement of the piezoelectric sheet. When the vehicle passes by, the piezoelectric sheet in the improved structure of this application is displaced in the mid-span, causing stress concentration in the mid-span, thereby driving stress concentration in the piezoelectric sheet. For the same force applied to these two structures, the improved amplified structure is fixed at one end, and the other end is displaced in the opposite direction to the mid-span. The stress is evenly distributed at both ends and the mid-span, so the curvature of the piezoelectric sheet at this time is much larger than that of the cantilever structure, so the output power is higher.
[0016] 4) The distance between the upper ends of the two side plates of the upper cover and the lower cover is 3mm. At the same time, a spring with a free state of 4mm and a working state of 3mm is selected to connect the upper cover and the lower cover. During the driving process of the vehicle, the displacement of the stainless steel substrate can be controlled to not exceed 3mm, which plays a role in controlling the displacement and avoiding the piezoelectric sheet from being broken due to excessive displacement.
[0017] 5) The semi-cylinder is selected as the support point because its smooth round surface is conducive to the work of the entire structure, and can reduce the damage of the stainless steel substrate and the semi-cylinder, and improve the durability of the internal components of the structure.
[0018] 6) By setting the second semi-cylinder at a position deviating from the middle, it can be avoided to be in the same vertical position as the first semi-cylinder, so that the effect of amplifying the displacement of this device can be maximized. The second semi-cylinder offsets the midpoint position of the pad to exert the "double lever" effect of this device. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The present invention will be further described below in conjunction with the accompanying drawings and embodiments: Figure 1 It is the front view of the present invention.
[0020] Figure 2 It is a top view of the present invention.
[0021] Figure 3 It is a schematic diagram of the partial structure of the present invention (removing the side cover plate at the front end).
[0022] Figure 4 It is the front view of the present invention.
[0023] Figure 5 It is a schematic diagram of the partial structure of the present invention (removing the side covers and upper cover plates at the front and rear ends).
[0024] In the figure: spring 1, first U-shaped part 2, groove 3, second U-shaped part 4, substrate 5, first semi-cylinder 6, pad 7, second semi-cylinder 8, upper cover plate 9, lower cover plate 10, piezoelectric sheet 11, side cover plate 12. DETAILED DESCRIPTION
[0025] like Figure 1-2 As shown, a bending piezoelectric energy harvester includes a piezoelectric sheet 11. The piezoelectric sheet 11 is made of PZT-PZNM ceramics, the piezoelectric strain constant is d31, and the size is 38mm×38mm×0.2mm. Due to the particularity of the material, this material is different from traditional piezoelectric materials in that it generates electricity by bending deformation, which creates the particularity of its structure. This type of element is highly sensitive to displacement. Under a concentrated load of 100N, the mid-span displacement of a single piezoelectric ceramic reaches 10mm, so a suitable substrate must be selected to control its deformation; at the same time, for the sake of safety, its mid-span displacement must also be controlled from the source, so this structure is introduced.
[0026] The piezoelectric sheet 11 is attached to the substrate 5 through a process. The substrate 5 is made of stainless steel and has a size of 65 mm×40 mm×1 mm.
[0027] The middle lower end of the base plate 5 contacts the upper edge of the first semi-cylinder 6, which is fixed on the pad 7. The lower end of the pad 7 deviates from the middle position and contacts the upper edge of the second semi-cylinder 8, which is fixed on the lower cover 10.
[0028] The first semi-cylinder 6 and the second semi-cylinder 8 have the same structure and are both semi-cylinders with the same size. The cross-sections have a radius of 5 mm and a length of 40 mm.
[0029] The lower cover plate 10 is assembled and fixed into a U shape by means of left and right vertical side plates and a horizontal plate at the lower end, and the left and right vertical side plates are 60 mm long, 20 mm wide, and 6 mm thick, and a groove 3 is opened transversely 3 mm from the top, and the groove 3 is 41 mm long, 4.4 mm wide, and 4 mm deep. The groove 3 can facilitate the insertion of the substrate 5.
[0030] The two ends of the substrate 5 are inserted into the grooves 3 on the left and right sides of the lower cover plate 10. The substrate 5 is inserted into the groove 3 to a depth of 3 mm, and 3 mm is reserved below.
[0031] The upper ends of the vertical side plates on the left and right sides of the lower cover plate 10 are connected to the upper cover plate 9 through springs 1, and the number of springs 1 is at least two. The natural length of the spring 1 is 4mm, and the working length is 3mm due to the self-weight of the upper cover plate 9. The upper cover plate 9 is a flat plate with a size of 75mm×60mm×5mm.
[0032] The first U-shaped member 2 and the second U-shaped member 4 are hinged at the left and right ends of the pad 7, respectively. The first U-shaped member 2 and the second U-shaped member 4 have the same structure, both of which are U-shaped. The two flanges (vertical parts) of the first U-shaped member 2 and the second U-shaped member 4 are rotatably connected to the side wall of the pad 7, and the upper end surfaces of the webs (horizontal parts) of the first U-shaped member 2 and the second U-shaped member 4 are in contact with the lower end of the upper cover plate 9. The lower end surfaces of the webs of the first U-shaped member 2 and the second U-shaped member 4 are in contact with the base plate 5.
[0033] In addition, side cover plates 12 are fixed at the front and rear of the lower cover plate 10 , and the side cover plates 12 limit and guide the front and rear ends of the upper cover plate 9 to prevent the upper cover plate 9 from deviating forward and backward.
[0034] Except for the substrate 5 and the piezoelectric sheet 11, all the plates in the above-mentioned device are made of nylon material. Nylon material has high mechanical strength, good toughness, high tensile and compressive strength, especially good fatigue resistance, durability and corrosion resistance. It also has excellent electrical properties and good electrical insulation, so it is suitable for this device.
[0035] Installation process: 1) First, the piezoelectric sheet 11 is attached to the substrate 5 through a process.
[0036] 2) Next, the first U-shaped member 2 , the second U-shaped member 4 and the backing plate 7 are installed as a whole, and the first U-shaped member 2 and the second U-shaped member 4 can rotate relative to the backing plate 7 .
[0037] 3) The substrate 5 passes through the first U-shaped member 2 and the second U-shaped member 4, and the middle of the lower end surface of the substrate 5 contacts the first semi-cylinder 6; at the same time, the upper end surface of the substrate 5 is in close contact with the lower end surfaces of the horizontal parts of the first U-shaped member 2 and the second U-shaped member 4. The inner side surfaces of the vertical parts of the first U-shaped member 2 and the second U-shaped member 4 are in close contact with the front and rear side surfaces of the substrate 5.
[0038] 4) Assemble and fix the two vertical side plates of the lower cover plate 10 with the horizontal plate at the bottom, insert the two ends of the base plate 5 into the groove 3, and the pad 7 contacts the second semi-cylinder 8 on the lower cover plate 10. The two vertical side plates of the lower cover plate 10 are connected to the upper cover plate 9 at the upper end through the spring 1.
[0039] 5) The lower cover plate 10 is fixed front and back by the side cover plate 12, and the upper cover plate 9 can rise and fall and be guided by the side cover plate 12 to limit the front and back.
[0040] Working principle: 1) If Figure 2 , 4 As shown, when the vehicle travels from left to right, the left end of the device is subjected to force, and the left end of the upper cover plate 9 is displaced downward (the maximum displacement does not exceed 3 mm), thereby driving the first U-shaped member 2 to move downward, and the downward movement of the first U-shaped member 2 drives the left end of the pad 7 to move downward; when the left end of the pad 7 moves downward, the right end of the pad 7 moves upward at the same time, and the second U-shaped member 4 is also slightly displaced upward by the action of the spring.
[0041] 2) Since both ends of the substrate 5 are inserted into the groove 3, when not under force, the upper end surface of the substrate 5 contacts the upper end surface of the groove 3, and the front and rear sides of the substrate 5 contact the front and rear sides of the groove 3. Therefore, when the above process 1) occurs, the right end of the substrate 5 is fixed and the left end moves downward. The first semi-cylinder 6 has a slight upward displacement as a support, which causes the substrate 5 to drive the middle part of the piezoelectric sheet 11 to bend.
[0042] 3) After the first stage, when entering the second stage, the tire presses over the right end of the upper cover plate 9, and the right end of the upper cover plate 9 moves downward, thereby driving the second U-shaped member 4 to move downward, and the second U-shaped member 4 drives the right end of the pad 7 to move downward; the left end of the pad 7 moves upward at the same time, and the first U-shaped member 2 also has a slight upward displacement due to the action of the spring.
[0043] 4) When the process 3) above occurs, the right end of the substrate 5 moves downward, and the left end of the substrate 5 is limited by the upper end surface of the groove 3 and remains stationary. The substrate 5 has a slight downward displacement in the span, which can be ignored. The right end of the substrate 5 moves downward due to the tire pressure, so the substrate 5 also bends in the mid-span at this time, thereby driving the piezoelectric ceramics on the substrate 5 to bend in the mid-span, and this cycle continues.
[0044] The process of burying the piezoelectric collector: first select a piece of vacant land, mark a 75×62×63mm³ space, use a road cutting machine to cut along the mark, dig out the asphalt and gravel, clean them with clean water, keep the bottom of the excavated groove flat, and then air dry it. Fill 10mm fine sand in the road groove and compact it for leveling. Put the piezoelectric collector on the fine sand, then spread 10mm asphalt to cover the piezoelectric collector, then pour asphalt oil, and finally spread 10mm asphalt and compact it with a road compactor.
Claims
1. A bending piezoelectric energy harvester, characterized in that: The invention comprises a substrate (5) with a piezoelectric sheet (11), wherein the middle of the lower end of the substrate (5) contacts the arcuate surface of a first semi-cylinder (6), and the two ends of the substrate (5) extend into a groove (3) of a lower cover plate (10) and are limited by the upper end surface of the groove (3); the first semi-cylinder (6) is mounted on a lever assembly, the upper left and right ends of the lever assembly contact the upper cover plate (9), and the lower end of the lever assembly contacts the arcuate surface of a second semi-cylinder (8) at the bottom end of the lower cover plate (10); the upper left and right ends of the lower cover plate (10) are connected to the upper cover plate (9) via springs (1); when the left end or the right end of the upper cover plate (9) is squeezed, the lever assembly correspondingly drives the left end or the right end of the substrate (5) to perform mid-span bending with the first semi-cylinder (6) as support.
2. The bending piezoelectric energy harvester according to claim 1, characterized in that: The lever assembly comprises a backing plate (7), a first U-shaped member (2) being rotatably mounted on the left end of the backing plate (7), and a second U-shaped member (4) being rotatably mounted on the right end, the first U-shaped member (2) and the second U-shaped member (4) having the same structure and both being U-shaped.
3. The curved piezoelectric energy harvester according to claim 2, characterized in that: The lower end surfaces of the horizontal parts of the first U-shaped part (2) and the second U-shaped part (4) are in contact with the upper end surface of the base plate (5), and the relatively inner side surfaces of the vertical parts of the first U-shaped part (2) and the second U-shaped part (4) are in contact with the front and rear side surfaces of the base plate (5).
4. The bending piezoelectric energy harvester according to claim 1, characterized in that: The distance between the base plate (5) and the lower end surface of the groove (3) is no greater than the distance between the upper cover plate (9) and the upper end surface of the lower cover plate (10).
5. The bending piezoelectric energy harvester according to claim 1, characterized in that: The first semi-cylinder (6) is located at a middle position of the upper end of the pad (7), and the second semi-cylinder (8) is located at a position deviated from the middle position of the lower end of the pad (7).
6. The bending piezoelectric energy harvester according to claim 1, characterized in that: The substrate (5) is made of stainless steel, and the piezoelectric sheet (11) is made of PZT-PZNM ceramic material.
7. The bending piezoelectric energy harvester according to claim 1, characterized in that: The upper cover plate (9), the lower cover plate (10), the first semi-cylinder (6), the second semi-cylinder (8), the pad (7), the first U-shaped member (2) and the second U-shaped member (4) are all made of nylon material.
8. The bending piezoelectric energy harvester according to claim 1, characterized in that: Side cover plates (12) are fixed to the front and rear of the lower cover plate (10).
9. A method for displacement amplification of a bending piezoelectric energy harvester according to any one of claims 1 to 8, comprising the following steps: Step 1), first, the piezoelectric sheet (11) is attached to the substrate (5) through a process; Step 2), then, the first U-shaped member (2), the second U-shaped member (4) and the backing plate (7) are installed as a whole, and the first U-shaped member (2) and the second U-shaped member (4) can rotate relative to the backing plate (7); Step 3), the substrate (5) passes through the first U-shaped member (2) and the second U-shaped member (4), and the middle of the lower end surface of the substrate (5) contacts the first semi-cylinder (6); at the same time, the upper end surface of the substrate (5) is in close contact with the lower end surfaces of the horizontal parts of the first U-shaped member (2) and the second U-shaped member (4); the inner side surfaces of the vertical parts of the first U-shaped member (2) and the second U-shaped member (4) are in close contact with the front and rear side surfaces of the substrate (5); Step 4), assemble and fix the two vertical side plates of the lower cover plate (10) and the horizontal plate at the bottom, so that the two ends of the base plate (5) are inserted into the groove (3), the base plate (5) contacts the upper end surface of the groove (3) and maintains a certain distance from the lower end surface of the groove (3); the pad (7) contacts the second semi-cylinder (8) on the lower cover plate (10); the two vertical side plates of the lower cover plate (10) and the upper cover plate (9) at the upper end form a whole through the spring (1); Step 5), the lower cover plate (10) is fixed front and rear by the side cover plates (12), and the upper cover plate (9) can rise and fall and be guided front and rear by the side cover plates (12); Step 6), install the device in the road surface groove and lay asphalt for compaction; Step 7), when the vehicle travels from left to right, the left end of the device is subjected to force, and the left end of the upper cover plate (9) moves downward, thereby driving the first U-shaped member (2) to move downward, and the downward movement of the first U-shaped member (2) drives the left end of the pad (7) to move downward; when the left end of the pad (7) moves downward, the right end of the pad (7) moves upward at the same time, and the second U-shaped member (4) also moves slightly upward under the action of the spring; Step 8), since both ends of the substrate (5) are inserted into the groove (3), in the unstressed state, the upper end surface of the substrate (5) contacts the upper end surface of the groove (3), and the front and rear side surfaces of the substrate (5) contact the front and rear side surfaces of the groove (3), so when step 7) occurs, the right end of the substrate (5) is fixed and the left end moves downward; the first semi-cylinder (6) as a support has a slight upward displacement, which causes the substrate (5) to drive the middle part of the piezoelectric sheet (11) to bend; Step 9), after the first stage is passed and the second stage is entered, the tire presses over the right end of the upper cover plate (9), and the right end of the upper cover plate (9) moves downward, thereby driving the second U-shaped member (4) to move downward, and the second U-shaped member (4) drives the right end of the pad (7) to move downward; the left end of the pad (7) moves upward at the same time, and the first U-shaped member (2) also moves slightly upward under the action of the spring; Step 10), when step 9) occurs, the right end of the substrate (5) moves downward, and the left end of the substrate (5) is limited by the upper end surface of the groove (3) and remains stationary. The substrate (5) has a slight downward displacement in the middle of the span, which can be ignored. The right end of the substrate (5) moves downward due to the tire pressure, so the substrate (5) also bends in the middle of the span, thereby driving the piezoelectric ceramic on the substrate (5) to bend in the middle of the span, and the cycle continues.