Piezoelectric energy harvesting device based on road tile transducer

Abstract

The application discloses a piezoelectric energy collection device based on a road tile transducer, which comprises a box and a power generation structure arranged in the box. The box comprises a box body and an upper cover. A plurality of transverse protrusions are arranged on the two side walls of the box body in the height direction. A middle rack is fixed in the middle of the two side walls, and a placing groove is formed between the middle rack and the side walls. A plurality of transverse protrusions are arranged on the two sides of the middle rack corresponding to the two side walls. A plurality of tile piezoelectric transducers are arranged on the transverse protrusions of the side walls of the box body and the transverse protrusions of the middle rack. A force transmission rod rack is arranged in the placing groove. The force transmission rod rack presses the tile piezoelectric transducer in the same placing groove. An elastic mechanism is arranged between the upper cover and the box body. A vibration space is left between the upper cover and the box body. The lower side of the upper cover is connected with the force transmission rod rack and transmits pressure to the force transmission rod rack. The tile piezoelectric transducer is connected with an energy storage unit. The piezoelectric energy collection device has high bearing capacity, the power collection devices are more densely distributed, and the power collection efficiency is higher.

Description

Technical Field

[0001] The present invention relates to a piezoelectric energy harvesting device, in particular to a piezoelectric energy harvesting device based on a road tile transducer. Background Art

[0002] Due to the depletion of traditional fossil fuel resources and increasingly serious ecological and environmental problems, the world is striving to transition to clean, green, and renewable energy. Road energy harvesting systems primarily include geothermal energy conversion, solar energy conversion, and piezoelectric energy conversion. For geothermal energy conversion, the temperature gradient of asphalt pavement is insufficient for large-scale power generation. For solar energy conversion, photovoltaic panels lack sufficient rigidity to couple with the pavement material, are prone to breakage, warping, and failure under the impact of vehicle loads, and are severely restricted by weather and geographical conditions. Therefore, utilizing the mechanical energy generated by vehicle vibration for piezoelectric energy conversion is currently the most promising clean energy acquisition method in road energy harvesting systems.

[0003] Pavement piezoelectricity is a potential clean energy source. When traffic loads work on the road surface, mechanical energy is generated. However, this energy is dissipated into the environment as heat. Harvesting piezoelectric energy through pavement piezoelectricity harvesting technology and converting it into electricity could not only mitigate damage to the road surface caused by traffic loads, but also address power supply difficulties in remote areas, reduce road construction costs, and provide a new and applicable method for monitoring the health of civilian infrastructure.

[0004] Transducer structure is a key factor influencing the efficiency of piezoelectric energy harvesting. Previous studies have shown that cantilever beam structures offer high energy output, but their resonant frequency struggles to match road vibration frequencies, and they occupy a large space, making them unsuitable for embedding within pavement structures requiring high stiffness and density. Stacked structures are compact, easy to fabricate, and offer high load-bearing capacity, but they also suffer from high stiffness and low energy output. Cymbal and bridge structures, while offering high energy output, are difficult to fabricate and have moderate load-bearing capacity. Under fatigue cyclic loading, stress concentration on the inner edge of the end cap can easily lead to brittle fracture of the piezoelectric ceramic. The THUNDER and RAINBOW transducers developed by NASA's Langley Research Center rank first in vibration absorption and energy harvesting efficiency under low-frequency vibration. However, the TUHNDER transducer has a low load-bearing capacity and unpredictable curvature after cooling from high temperatures, making it unsuitable for road power generation systems. Therefore, developing a road-use piezoelectric transducer structure with significant energy output, high load-bearing capacity, fatigue resistance, and ease of fabrication, and integrating it with a piezoelectric energy harvester for practical application, is of vital importance. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a piezoelectric energy harvesting device based on a road tile transducer, which has a higher bearing capacity, a denser distribution of energy collection devices, and a higher energy collection efficiency.

[0006] To this end, the present invention provides a piezoelectric energy harvesting device based on a road tile transducer, which is characterized in that it includes a box and a power generation structure arranged inside the box, the box including a box body and an upper cover, and the two side walls of the box body are parallelly distributed with multiple transverse ridges in the height direction, and a middle platform is fixed in the middle of the two side walls, and a placement groove is formed between the middle platform and the side walls, and multiple transverse ridges are arranged on both sides of the middle platform corresponding to the two side walls, and multiple tile-type piezoelectric transducers are mounted on the transverse ridges on the side walls of the box body and the transverse ridges on the middle platform, and a force transmission rod platform is arranged in the placement groove, and the force transmission rod platform compresses the tile-type piezoelectric transducers in the same placement groove, an elastic mechanism is provided between the upper cover and the box body, and an upper and lower vibration space is left between the upper cover and the box body, the lower side of the upper cover is connected to the force transmission rod platform and transmits pressure to it, and the tile-type piezoelectric transducer is connected to the energy storage unit.

[0007] Furthermore, the transverse ridges on the side walls of the box body and the sides of the middle frame are provided with slots, and the insert plates are inserted into the slots of the transverse ridges on each layer from top to bottom, and each interlayer separated by the insert plates is provided with a tile-type piezoelectric transducer.

[0008] Furthermore, the tile-type piezoelectric transducer includes an arched spring steel base, an arched piezoelectric ceramic, and an upper arched aluminum cover plate, which are sequentially bonded together by epoxy resin glue.

[0009] Furthermore, both side ends of the spring steel sheet base have curled edges that are rolled up.

[0010] Furthermore, the upper cover has a lower edge, which surrounds the outside of the box body. Spring holes are opened at the four corners of the box body. The upper cover has a convex column aligned with the spring hole, and a spring is provided between the convex column and the bottom of the spring hole.

[0011] Furthermore, a silicone rubber strip is provided on the inner side of the lower edge.

[0012] Furthermore, the force transmission rod stand includes two end frames, a force transmission rod is fixed between the two end frames corresponding to the tile-type piezoelectric transducer, a sleeve ring is fixed on the aluminum cover plate of the tile-type piezoelectric transducer, and the force transmission rod of the interlayer passes through the sleeve ring of the tile-type piezoelectric transducer of the corresponding layer.

[0013] Furthermore, the piezoelectric energy harvesting device is divided into four layers, with 10 tile-type piezoelectric transducers in each layer, for a total of 40 tile-type piezoelectric transducers, all of which are connected in parallel.

[0014] Furthermore, the force transmission rod is connected to the upper cover by bolts, and the positive and negative wires of the piezoelectric energy harvesting device are led out of the box body through the wire holes.

[0015] Technical effects of the present invention:

[0016] (1) THUNDER and RAINBOW rank first in vibration absorption and energy collection efficiency under low-frequency vibration. However, their bearing capacity is insufficient, and the curvature formed after high-temperature cooling is difficult to predict. Therefore, a tile-type piezoelectric transducer made using ceramic grinding and polishing technology has significant energy output, high bearing capacity, fatigue resistance, and is easy to manufacture.

[0017] (2) The piezoelectric energy harvesting device is divided into four layers by the setting of the force transmission rod stand and the force transmission rod. Each layer has 10 tile-type piezoelectric transducers, and there are a total of 40 tile-type piezoelectric transducers, which improves the energy density of the piezoelectric energy harvesting device.

[0018] (3) As a non-destructive road and bridge monitoring method, wireless road and bridge health monitoring sensors can be buried around the piezoelectric energy harvesting device, reducing wiring, having sufficient energy sources, and no need for manual battery charging or replacement, with low maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the split structure of the piezoelectric energy harvesting device based on the road tile transducer provided in Example 1 of the present invention.

[0020] Figure 2 for Figure 1 Schematic diagram of the split structure of the tile-type transducer.

[0021] Figure 3 This is a schematic structural cross-sectional view of the length direction of the box body of the piezoelectric energy harvesting device based on the road tile transducer provided in Example 2 of the present invention.

[0022] Figure 4 for Figure 3 Schematic diagram of the structure after the card slot of the box body is inserted into the plug-in board.

[0023] Figure 5 A schematic structural cross-sectional view of the box body width direction of a piezoelectric energy harvesting device based on a road tile transducer provided in Example 2 of the present invention. DETAILED DESCRIPTION

[0024] The application will be described in further detail below with reference to the drawings and embodiments. Identical parts are denoted by identical reference numerals in the description. It should be noted that the words "front", "back", "left", "right", "upper" and "lower" used in the following description refer to the directions in the drawings, and the words "bottom" and "top", "inner" and "outer" refer to the directions towards or away from the geometric center of a particular part.

[0025] Referring to Figure 1-2 As shown in the drawings, the piezoelectric energy harvesting device based on tile-shaped transducer provided by the embodiment 1 of the application comprises a box and a power generation structure arranged inside the box. The box comprises a box body and an upper cover 1. The box body comprises side walls 2 and a bottom plate 3. The side walls 2 and end head plates are fixedly connected by tenon 4 and mortise 5 insertion. The upper end of the side wall 2 has an end face 7. A plurality of transverse protrusions 8 are arranged on the side walls 2 along the height direction. A middle rack 9 is fixedly arranged between the side walls 2. The middle rack 9 and the side walls 2 form a placing groove. A plurality of transverse protrusions 8 are arranged on the middle rack 9 corresponding to the side walls 2. A plurality of tile-shaped piezoelectric transducers 12 are arranged on the transverse protrusions 8 of the side walls 2 and the middle rack 9. A force transmission rod rack 10 is arranged in the placing groove. The force transmission rod rack 10 presses the tile-shaped piezoelectric transducer 12 in the same placing groove. An elastic mechanism is arranged between the upper cover 1 and the box body. An up-down vibration space is left between the upper cover 1 and the box body. The lower side of the upper cover 1 is connected with the force transmission rod rack 10 and transmits pressure to it. The force transmission rod 11 can be rectangular. The force transmission rod 11 is connected with the upper cover 1 by bolts. The positive and negative electrode leads of the piezoelectric energy harvesting device are led out of the box body through the lead hole 6. The tile-shaped piezoelectric transducer 12 is connected with the energy storage unit 13. The energy storage unit 13 is composed of a super capacitor and an energy collection circuit. The above piezoelectric energy harvesting device is divided into four layers. There are 10 tile-shaped piezoelectric transducers 12 in each layer. There are 40 tile-shaped piezoelectric transducers 12 in total. They are connected in parallel. According to different vehicle speeds and weights, the voltage can reach dozens of volts and the current can reach tens of milliamperes. The 40 tile-shaped piezoelectric transducers 12 are connected in parallel after rectification. The super capacitor is charged through the energy collection circuit. The energy management unit 13 can supply power to the road bridge auxiliary facilities.

[0026] Referring to Figure 2As shown, the tile-type piezoelectric transducer 12 comprises an arched spring steel base 14, an arched piezoelectric ceramic 15, and an upper arched aluminum cover plate 16, which are bonded in sequence with epoxy resin glue. The curvature of the tile-type transducer 12 is 1 / 200.5. The raw materials are mixed and ground according to the formula calculation, pre-sintered, and then granulated with polyvinyl alcohol adhesive after secondary grinding. The materials are then dry-pressed and formed using a cold isostatic press (forming pressure is 16 MPa), and sintered into blocks after debinding. The key to making the tile-type transducer 12 is to use a grinder and customized grinding tools to grind ceramics with precise curvature, and then polish the surface. Silver electrodes are applied to the upper and lower surfaces and polarized. Considering that the upper and lower surfaces of the piezoelectric ceramic need to be bonded to the aluminum sheet and the spring steel sheet respectively, side electrodes 17 are designed. The silver electrodes on the upper and lower surfaces of the piezoelectric ceramic are extended to the side using a silver coating method for welding the positive and negative electrode wires.

[0027] The piezoelectric energy harvester is buried as follows: Use a pavement cutter to cut a rectangular trench 10 cm deep, with the length and width equal to the size of the piezoelectric energy harvester plus 1 cm. After the trench is cut, remove any debris and accumulated water from the trench and blow dry it with a street hair dryer until no visible water remains. Apply a 3mm layer of polyurethane as a tack coat to the bottom of the trench, followed by a 1.7cm layer of asphalt mortar, compacted and leveled. Apply a 2mm layer of polyurethane around the edges, insert an engineering plastic fixed housing, place the piezoelectric energy harvester inside the housing, and apply a 2mm layer of polyurethane to the surface for wear protection. Finally, caulk the seams with SBS-modified asphalt.

[0028] Reference Figure 3-5 As shown, Example 2 of the present invention is basically the same as Example 1, and the only difference is that the following structure is added: the transverse ridges 8 distributed on both sides of the box side walls 2 and the middle stand 9 in Example 2 are provided with card grooves 18, and the insert plates 19 are inserted from top to bottom into the card grooves 18 of the transverse ridges 8 of each layer on both sides. Each partition formed by the insert plates 19 is provided with one of the tile-type piezoelectric transducers 12. The insert plates 19 separate the tile-type piezoelectric transducers 12 so that adjacent tile-type piezoelectric transducers 12 do not interfere with each other.

[0029] Reference Figure 5 As shown, the spring steel sheet base 14 has upwardly curled edges 20 on both sides. The spring steel sheet is manufactured using a hot coiling method, where a hot, flat spring steel sheet is placed into a mold precisely manufactured to a curved surface, and then rolled into a curved surface. The curved spring steel sheet is then subjected to a high-temperature quenching treatment at 810°C, oil cooling, and then a medium-temperature tempering treatment at 350°C.

[0030] Reference Figure 3-5As shown, the upper cover 1 of this embodiment 2 has a lower edge 1a, which surrounds the outer side of the box body. A silicone rubber strip 21 is provided on the inner side of the lower edge 1a. Spring holes 22 are provided at the four corners of the box body. The upper cover 1 is aligned with the spring holes 22 and has a protrusion 23. A spring 24 is provided between the protrusion 23 and the bottom of the spring hole 22.

[0031] Reference Figure 5 As shown, the dowel rod stand 10 includes two end frames 10a, with a dowel rod 11 fixed between the end frames 10a, corresponding to the tile-type piezoelectric transducer. The dowel rod 11 of Example 2 has a circular cross-section. A sleeve ring 16a is fixed to the aluminum cover plate 16 of the tile-type piezoelectric transducer 12. The dowel rod 11 of the interlayer passes through the sleeve ring 16a of the tile-type piezoelectric transducer 12 of the corresponding layer. This dowel rod 11 can more stably transmit pressure to the tile-type transducer 12 and can more stably synchronize with the tile-type transducer 12.

[0032] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiment. All technical solutions based on the concept of the present invention are within the scope of protection of the present invention. It should be noted that for those skilled in the art, various improvements and modifications that do not depart from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A piezoelectric energy harvesting device based on a road tile transducer, characterized by: The box comprises a box body and an upper cover, and the two side walls of the box body are parallelly distributed with a plurality of transverse ridges along the height direction, a middle stand is fixed in the middle of the two side walls, and a placement groove is formed between the middle stand and the side walls, and a plurality of transverse ridges are provided on both sides of the middle stand corresponding to the two side walls, and a plurality of tile-type piezoelectric transducers are mounted on the transverse ridges of the side walls of the box body and the transverse ridges on the middle stand, and a force transmission rod stand is provided in the placement groove, and the force transmission rod stand compresses the tile-type piezoelectric transducers in the same placement groove, an elastic mechanism is provided between the upper cover and the box body, and an upper and lower vibration space is left between the upper cover and the box body, the lower side of the upper cover is connected to the force transmission rod stand and transmits pressure to it, and the tile-type piezoelectric transducer is connected to the energy storage unit; The transverse ridges on the side walls of the box body and on both sides of the middle frame are provided with slots, and the inserting plates are inserted into the slots of the transverse ridges on each layer from top to bottom. Each interlayer formed by the inserting plates is provided with one of the tile-type piezoelectric transducers; The tile-type piezoelectric transducer comprises an arched spring steel base, an arched piezoelectric ceramic and an upper arched aluminum cover plate which are bonded in sequence by epoxy resin glue; Both sides of the spring steel sheet base have upwardly curled edges; The upper cover has a lower edge, which surrounds the outer side of the box body. The box body has spring holes at four corners. The upper cover is aligned with the spring holes and has a convex column. A spring is provided between the convex column and the bottom of the spring hole. A silicone rubber strip is provided on the inner side of the lower edge; The force transmission rod stand includes two end frames, a force transmission rod is fixed between the two end frames corresponding to the tile-type piezoelectric transducer, a sleeve ring is fixed on the aluminum cover plate of the tile-type piezoelectric transducer, and the force transmission rod of the interlayer passes through the sleeve ring of the tile-type piezoelectric transducer of the corresponding layer; The piezoelectric energy harvesting device is divided into four layers, with 10 tile-type piezoelectric transducers on each layer, for a total of 40 tile-type piezoelectric transducers, all of which are connected in parallel.

2. The piezoelectric energy harvesting device based on a road tile transducer according to claim 1, characterized in that: The force transmission rod is connected to the upper cover through bolts, and the positive and negative wires of the piezoelectric energy harvesting device are led out of the box body through the wire holes.

3. The piezoelectric energy harvesting device based on a road tile transducer according to claim 1 is characterized by: The force transmission rod is connected to the upper cover through bolts, and the positive and negative wires of the piezoelectric energy harvesting device are led out of the box body through the wire holes.

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