Piezoelectric energy producing floor

Abstract

The present invention relates to a piezoelectric energy producing floor comprising a floor tile (1) with a top plate (2), one or more arrays comprising sandwiches (3) each made up of a piezoelectric element (4) that is in electric connection with two copper plates (5, 6), a base unit (14), and with a bottom cover or base plate 7.

Description

[0001] PIEZOELECTRIC ENERGY PRODUCING FLOOR

[0002] The present invention relates to a piezoelectric energy producing floor comprising a floor tile with a top plate, one or more arrays comprising sandwiches of piezoelectric elements each in electric connection with two copper plates, a base unit, and a bottom cover or base plate.

[0003] Background of the invention

[0004] The concept of electricity-producing floors and walkways is often referred to as energy-harvesting flooring. It is a technology that captures kinetic energy from footsteps and other movements and converts it into electrical energy. Different type of energyharvesting technologies can be used, for instance piezoelectric materials and electromagnetic induction or a combination of the two types of energy production.

[0005] Piezoelectric materials generate an electric charge in response to mechanical stress, such as pressure from footsteps. These materials can be embedded in flooring tiles or mats, and it is one of the most common methods used in energy-harvesting floors that capture energy from foot traffic in public spaces like airports, shopping malls, and stadiums. Generally, the efficiency of energy conversion has been relatively low, meaning that the amount of energy produced per step is small, so it typically requires high foot traffic to generate meaningful power.

[0006] Electromagnetic induction uses coils and magnets to generate electricity. When pressure is applied (such as from a footstep), the motion of a magnet relative to a coil induces an electric current. However, energy conversion efficiency is low, and durability is a problem, as it takes a very robust system to handle the continuous mechanical stresses. Generally, a piezoelectric floor is preferred, and an example of such a floor is described in WO2018065854A1 . This floor will, however, tend to produce a limited amount of power due to insufficient control and coordination of the power produced in each piezoelectric element.

[0007] It is the object of the present invention to devise an improved piezoelectric floor with an enhanced energy production capacity.

[0008] According to the invention said piezoelectric energy producing floor that comprises a floor tile with a top plate, one or more arrays comprising sandwiches of piezoelectric elements, each in electric connection with two copper plates, a base unit and a bottom cover or base plate, is characterized in that each sandwich of piezoelectric element and cupper plates are provided with two wires for instance by fusing, and each set of wires from each piezoelectric sandwich is connected to a rectifier and voltage regulator circuit comprising, for each individual piezoelectric sandwich, a dedicated rectifier, a dedicated capacitor for temporary storage of the energy that is produced, and a dedicated diode.

[0009] In the preferred embodiment of the invention the capacitors are all via the diodes connected to a buck-converter (DC voltage regulator) that controls the voltage from each energy producing floor tile, that will optimize the energy production from each floor tile.

[0010] These means will ensure that as much as possible of the energy that is produced by each step on the floor will be turned into usable power. According to an embodiment of the invention the floor tiles are each provided with one or more fingers or male connectors on two sides, and one or more indentations or female connectors on two opposite sides, wherein each set of connectors comprises a positive and a negative pole, and all the positive and all of the negative connectors are mutually connected without need for wiring between the tiles.

[0011] In the presently preferred embodiment, there are four male and four female connectors on each tile.

[0012] Preferably, the base plate and the top plate are each provided with a bevelled edge adapted to receive a caulking compound.

[0013] This will ensure a good bond between top and bottom and will also provide a connection that is able to withstand dust, dirt, water, etc. from entering any part of the floor tile.

[0014] According to an embodiment of the present invention there is a distance between the top plate and the base plate, when the caulking compound is added, so that the top plate and the base plate are not in mutual contact, but there is a vertical guiding system embedded in the design of the top and bottom plate.

[0015] This allows the top and the bottom part of the tile to move in relation to each other. In combination with vertical guiding systems embedded in the design of the top and bottom plate, the possible travel of the upper plate in relation to the bottom part of the tile can be controlled to be purely vertical.

[0016] According to yet another embodiment of the invention the tile can be provided with both male and female mutually mating connectors on all sides, which will enable the tiles to be assembled regardless of which sides are facing one another. According to an embodiment the floor tiles can be turned upside down and still produce electricity. This is a feature that can be advantageous in some cases.

[0017] According to a preferred embodiment the piezoelectric energy producing floor comprises one or more piezoelectric energy producing floor tiles according to the invention comprises an edge band with a bus bar for receiving the produced electricity, said edge band being provided with means for keeping the floor tiles close together.

[0018] This feature might not be necessary in all cases, as the tiles are preferably clicked together in such a way that they will stay close together, but in some cases with much traffic it might be necessary to ensure that the tiles are kept tight together.

[0019] Furthermore, a bus bar can also be included in each of or some of the tiles.

[0020] According to the preferred embodiment of the invention a LoRa unit is provided in each floor-tile for wireless communication. In this way it is possible - without the use of wiring - to obtain relevant information such as, but not limited to, the frequency of traffic across a specific floor tile, as well as the state of health and localizing in scope of maintenance of each individual tile.

[0021] Detailed description of the invention

[0022] In the following the invention will be described in further detail referring to the drawing, in which

[0023] Fig. 1 shows an exploded perspective view of a floor tile according to the invention, seen from above,

[0024] Fig. 2 shows an exploded perspective view of a floor tile of Fig.

[0025] 1 , seen from below Fig. 3 shows a diagram of the rectifying and voltage regulation means for each tile, and

[0026] Fig. 4 shows an assembled floor in perspective view.

[0027] Figs. 1 and 2 show an example of an embodiment of a floor tile 1 according to the invention. It comprises a top plate 2 that functions as a pressure distributing plate, for instance made of a plastic material, a triple array comprising sandwiches 3 each made up of a piezoelectric element 4 that is in electric connection with two copper plates 5, 6. The sandwiches 3 are placed in one layer, but they could be stacked in order to enhance the number of piezoelectric plates and, hence, the total performance of each floor tile 1 , but the number of stacks can not be too high, so as to avoid an excessive floor tile thickness. The floor tile further comprises a base unit 14 with a bottom cover or base plate 7. As can be seen from Fig. 3, each sandwich 3 of a piezoelectric element 4 and two cupper plates 5, 6 is provided with two wires 8, 9, and each set of wires 8, 9 from each piezoelectric sandwich 3 is connected to a rectifier and voltage regulator circuit 15 located in the base unit 14 comprising a dedicated rectifier 10, a dedicated capacitor 11 for temporary storage of the energy that is produced, and a dedicated diode 12. The capacitors 11 are all via the diodes connected to a Buck converter 13 (DC voltage regulator) that regulates the voltage output from each energy producing floor tile. Energy is stored temporarily in the capacitors, as differences in performance of each sandwich, differences in resistance and uneven pressure from the top plate will entail that the piezoelectric sandwiches will supply different voltages to the voltage regulator, which, if not handled properly will result in the sandwich elements counteracting each other which will lead to inefficiency regarding energy harvesting. The capacitors ensure that the optimum production of power is achieved.

[0028] The base plate 14 and the pressure distributing plate 2 may be provided with a beveled edge, and they will not be in mutual contact. In this way a rubber caulking can be applied so as to glue the upper and lower parts of the tile together and keep the inside of the tile free of dust, grime, and moisture. Rubber caulking has a spring effect that can be utilized for enabling a movement between the upper and lower part of the tile. A sealing ring can also be used for mounting between the base plate 14 and the pressure distributing plate 2.

[0029] As it is seen most clearly in Fig. 4, there are nine floor tiles that are each provided with two fingers or male connectors 17 on two sides, and two indentations or female connectors 18 on two opposite sides. Each connector comprises a positive and a negative pole 16, and all of the positive and all of the negative poles 16 are mutually connected.

[0030] It is contemplated that a so called LoRa chip is used in each floor tile for gathering of data about the energy production of each tile, the state of each tile, and for analyzing of the traffic flow on the tile, etc.

[0031] As the floor tiles have low height, they can often be placed directly on top of existing floors, or the floor according to the invention can be lowered so as to achieve a level surface.

[0032] After assembling of the floor, a bus bar that is located inside an edge band that is provided with connectors that fit the connectors of the floor, is mounted on the system. The bus bar receives energy from all of the tiles, and it can be connected to for instance a battery unit, a DC-AC converter, etc. This invention has been described in connection with a floor for pedestrians. It should, however, be understood that the principles of the invention could also be used for other kinds of traffic, and could be used in roads, bike lanes, etc.

Claims

Claims1 . Piezoelectric energy producing floor comprising a floor tile (1 ) with a top plate (2), one or more arrays comprising sandwiches (3) each made up of a piezoelectric element (4) that is in electric connection with two copper plates (5), (6), a base unit (14) with a bottom cover or base plate (7), characterized in that each sandwich (3) of a piezoelectric element (4) and two cupper plates (5, 6) is provided with two wires (8, 9) for instance by fusing, and each set of wires (8, 9) from each piezoelectric sandwich (3) is connected to a rectifier and voltage regulator circuit (15) comprising , for each individual piezoelectric sandwich, a dedicated rectifier 10, a dedicated capacitor 11 for temporary storage of the energy that is produced, and a dedicated diode 12.

2. Piezoelectric energy producing floor according to claim 1 , wherein the capacitors are all via the diodes connected to a buck-converter (13) (DC voltage regulator) that regulates the voltage from each energy producing floor tile (1).

3. Piezoelectric energy producing floor according to claim 1 or 2, wherein the floor tiles (1 ) are each provided with one or more fingers or male connectors (17) on two sides, and one or more indentations or female connectors (18) on two opposite sides, wherein each set of connectors comprises a positive and a negative pole (16), and all of the positive and all of the negative connectors are mutually connected without need for wiring between the tiles.

4. Piezoelectric energy producing floor according to any of the previous claims, wherein there are four male (17) and four female (18) connectors on each tile (1 ).

5. Piezoelectric energy producing floor according to any of the previous claims, wherein the bottom plate (14) and the top plate (2) are each provided with a beveled edge adapted to receive a caulking compound, or a sealing ring.

6. Piezoelectric energy producing floor according to any of the previous claims, wherein there is a distance between the top plate (2) and the bottom plate (14), when the caulking compound is added, so that the top plate (2) and the bottom plate (14) are not in mutual contact, but there is a vertical guiding system embedded in the design of the top and bottom plate.

7. Piezoelectric energy producing floor according to any of the previous claims, wherein the tile (1 ) is provided with both male and female mutually mating connectors (17, 18) on all sides.

8. Piezoelectric energy producing floor according to any of the previous claims, wherein the floor tiles (1 ) can be turned upside down and still produce electricity.

9. Piezoelectric energy producing floor according to any of the previous claims, wherein the floor comprises an edge band with a bus bar for receiving the produced electricity, said edge band being provided with means for keeping the floor tiles close together.

10. Piezoelectric energy producing floor according to any of the previous claims, wherein a LoRa unit is provided in each floor tile for wireless communication.

Images