Wireless power supply system and mobile body

Abstract

To improve power transmission efficiency.SOLUTION: A wireless power supply system includes: a power transmission unit that is provided in a standing part standing from a floor surface and has a power transmission electrode to wirelessly transmit power; a power reception unit that is provided in a mobile body capable of moving and receives power from the power transmission electrode when positioned facing the power transmission electrode; and a displacement absorption unit that adsorbs displacement of the power transmission unit or the power reception unit in accordance with movement of the mobile body.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a wireless power supply system and a mobile object. [Background technology]

[0002] In recent years, wireless power supply systems that wirelessly supply power to mobile objects that use electrical energy as their power source, such as electric vehicles, electric carts, and AGVs (Automated Guided Vehicles), have been attracting attention. In wireless power supply systems, for example, a power transmitting electrode is buried under the road surface on which the mobile object stops, and power is supplied wirelessly and contactlessly to a power receiving electrode provided on the mobile object, thereby charging a battery mounted on the mobile object. Furthermore, by burying power transmitting electrodes continuously under the road surface on which the mobile object moves, the mobile object can also move using power transmitted from the road surface.

[0003] When installing a power transmitting electrode under the road surface, lossy materials such as concrete and dielectrics containing moisture are stacked above and below the power transmitting electrode, which can affect the efficiency of power transmission between the power transmitting electrode and the power receiving electrode. In addition, installing a power transmitting electrode under the road surface requires digging up the road surface and burying the electrode and other components, which is time-consuming.

[0004] Therefore, it has been considered to provide a wall along the direction of movement of the moving body and to install a power transmission electrode on the wall. For example, by providing the power transmission electrode on a side wall that rises on the side of the moving body, it is possible to prevent foreign objects from being placed on the power transmission electrode and reduce the effort required for installing the power transmission electrode.

[0005] However, when installing a power transmitting electrode on a wall, the spatial impedance changes due to variations in the distance between the power transmitting and receiving electrodes, which changes the optimal matching condition, resulting in a decrease in power transmission efficiency. Specifically, when a mobile object moves autonomously along a side wall, the positioning accuracy is, for example, about 100 mm, and the mobile object may meander within this range. Therefore, as the mobile object moves, the distance between the power transmitting electrode installed on the side wall and the power receiving electrode on the mobile object changes, causing the impedance to fluctuate. This makes it difficult to always maintain the optimal matching condition using a matching circuit, resulting in a decrease in the average power transmission efficiency.

[0006] Furthermore, for example, when a mobile object is parked at a predetermined parking position and is charged by supplying power from the power transmitting electrode of the wall, if the position at which the mobile object is parked deviates from the parking position, the power transmission efficiency decreases, and the charging efficiency also decreases. Furthermore, when the mobile object is parked at the parking position, the misalignment of the mobile object may cause the power receiving electrode and the power transmitting electrode to collide, which may result in damage to the mobile object or the wall. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 2018-68077 Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present invention is to provide a wireless power supply system and a mobile object that can improve the efficiency of power transmission. [Means for solving the problem]

[0009] According to one aspect of the present invention, a wireless power supply system includes a power transmission unit provided on an upright portion that stands upright relative to a floor surface and having a power transmission electrode that transmits power wirelessly, a power receiving unit provided on a movable vehicle and having a power receiving electrode that receives power from the power transmission electrode when the power receiving unit is positioned opposite the power transmission electrode, and a displacement absorption unit that absorbs displacement of the power transmission unit or the power receiving unit due to movement of the vehicle.

[0010] With this configuration, even if the mobile object moves or shifts in position, the displacement of the power transmitting unit or the power receiving unit is absorbed, and the positional relationship between the power transmitting electrode and the power receiving electrode is maintained. As a result, the distance between the power transmitting electrode of the wireless power feeding wall and the power receiving electrode of the mobile object can be kept constant, thereby improving power transmission efficiency.

[0011] According to another aspect of the present invention, in the above configuration, the displacement absorbing unit has an expandable member having a fixed portion fixed to the moving body and an expandable portion supported by the fixed portion via an elastic body and expandable relative to the fixed portion, and the power receiving unit is attached to the tip of the expandable portion.

[0012] According to this configuration, the displacement of the power receiving unit is absorbed by the expansion and contraction of the expandable member fixed to the movable body, so that the position of the power receiving unit can be maintained even if the movable body moves or becomes displaced.

[0013] According to another aspect of the present invention, in the above configuration, the displacement absorbing section further includes a link having a first rod-shaped member fixed to the movable body, a second rod-shaped member that fixes the fixed portion of the expandable member, and a connecting member that connects the first rod-shaped member and the second rod-shaped member in an openable and closable manner.

[0014] With this configuration, the telescopic member is fixed to the openable link, so the angle of the telescopic member can be changed by opening and closing the link, which makes it possible to absorb large displacements of the power receiving unit that cannot be absorbed by the telescopic member alone.In addition, it is possible to absorb angular deviations between the power transmitting unit and the power receiving unit relative to each other that occur due to positional deviations of the moving object.

[0015] According to another aspect of the present invention, in the above configuration, the power receiving unit has a plate-shaped first panel attached to the tip of the extension / contraction unit, and a plate-shaped second panel that sandwiches the power receiving electrode between the first panel and the second panel.

[0016] According to this configuration, the power receiving electrode is sandwiched between the two panels, so that the surface of the power receiving electrode can be protected.

[0017] According to another aspect of the present invention, in the above configuration, the power receiving unit further has a roller member whose surface protrudes outward from the surface of the second panel and which rotates in a direction corresponding to the direction of movement of the movable body.

[0018] With this configuration, a rotatable roller member protrudes from the surface of the power receiving unit, so that when a moving object moves while the power receiving unit is in contact with the wireless power supply wall, wear due to friction between the surface of the wireless power supply wall and the surface of the power receiving unit can be prevented.

[0019] According to another aspect of the present invention, in the above configuration, the displacement absorption section has an expandable member having a fixed section fixed to the standing section and an expandable section supported by the fixed section via an elastic body and expandable relative to the fixed section, and the power transmission section is attached to the tip of the expandable section.

[0020] With this configuration, the displacement of the power transmission unit is absorbed by the expansion and contraction of the expandable member fixed to the erected portion, so that even if the mobile body moves or becomes misaligned, the position of the power transmission unit relative to the mobile body's power receiving unit can be maintained.

[0021] According to another aspect of the present invention, the mobile body includes a main body that moves using power transmitted wirelessly from a power transmitting electrode, a fixed portion that is fixed to the main body, an expandable member that has an expandable portion that is supported on the fixed portion via an elastic body and expands and contracts relative to the fixed portion, and a power receiving portion that is attached to the tip of the expandable portion and has a power receiving electrode that receives power from the power transmitting electrode when in a position facing the power transmitting electrode.

[0022] According to this configuration, the displacement of the power receiving unit is absorbed by the expansion and contraction of the expandable member fixed to the main body of the mobile object, so that even if the mobile object moves or becomes misaligned, the displacement of the power receiving unit is absorbed and the positional relationship between the power transmitting electrode and the power receiving electrode is maintained. As a result, the distance between the power transmitting electrode of the wireless power feeding wall and the power receiving electrode of the mobile object can be kept constant, thereby improving power transmission efficiency. [Effects of the Invention]

[0023] According to the present invention, it is possible to improve the power transmission efficiency. [Brief explanation of the drawings]

[0024] [Figure 1] FIG. 1 is a diagram showing a specific example of the configuration of a wireless power supply system according to an embodiment. [Figure 2] FIG. 2 is a block diagram showing the functions of a wireless power supply wall according to an embodiment. [Figure 3] FIG. 3 is a three-view diagram showing the configuration of a wireless power supply wall according to one embodiment. [Figure 4] FIG. 4 is a block diagram showing the functions of a moving object according to an embodiment. [Figure 5] FIG. 5 is a two-sided view showing the configuration of a moving body according to one embodiment. [Figure 6] FIG. 6 is a diagram illustrating an example of the positional relationship between the wireless power supply wall and the moving object. [Figure 7] FIG. 7 is a diagram illustrating another example of the positional relationship between the wireless power supply wall and the moving object. [Figure 8] FIG. 8 is a diagram showing yet another example of the positional relationship between the wireless power supply wall and the moving object. [Figure 9] FIG. 9 is a diagram showing a modified example of the wireless power feeding system. [Figure 10] FIG. 10 is a diagram showing another modified example of the wireless power feeding system. [Figure 11] FIG. 11 is a diagram showing yet another modified example of the wireless power feeding system. DETAILED DESCRIPTION OF THE INVENTION

[0025] An embodiment of the present invention will be described below with reference to the accompanying drawings. The embodiment described below is an example and should not be construed as being limited by this description.

[0026] Fig. 1 is a diagram showing a specific example of the configuration of a wireless power supply system according to an embodiment. The wireless power supply system shown in Fig. 1 includes a wireless power supply wall 100 erected on a road surface 300, and a moving object 200 moving on the road surface 300 along the wireless power supply wall 100.

[0027] The wireless power supply wall 100 is a wall erected from a road surface 300 along a movement path of a moving object 200. The wireless power supply wall 100 includes two parallel power supply electrodes 110 extending in the movement direction of the moving object 200, and supplies power wirelessly from the power supply electrodes 110 to the moving object 200.

[0028] The moving body 200 is, for example, a robot, an electric vehicle, an electric cart, or an AGV equipped with a moving means such as wheels 201, and moves on a road surface 300 using power supplied from the wireless power supply wall 100. That is, the moving body 200 moves along the wireless power supply wall 100, for example, in the direction of the arrow in the figure, using power supplied from the wireless power supply wall 100. As will be described later, the moving body 200 is provided with a power receiving electrode facing the power transmitting electrode 110, and moves using power received by the power receiving electrode. When moving, the moving body 200 meanders within the error range of its positional accuracy, but in this embodiment, a structure is provided that absorbs fluctuations in the distance between the electrodes, so that the distance between the power transmitting electrode 110 and the power receiving electrode is kept constant.

[0029] 2 is a block diagram showing the functions of the wireless power supply wall 100 according to one embodiment. The wireless power supply wall 100 shown in FIG.

[0030] The power transmitting electrode 110 is made of a conductive metal, and transmits power to the opposing power receiving electrode by, for example, an electric field coupling method in which a high-frequency alternating current is passed through to generate an electric field.

[0031] The commercial power supply 120 is a power supply that supplies electric power provided by a power supplier such as a power company. High frequency power supply 130 is a power supply that converts commercial frequency power supplied from commercial power supply 120 into high frequency power. The matching circuit 140 matches the impedance of the transmission line through which high-frequency power is transmitted, and causes a high-frequency alternating current to flow through the power transmitting electrode 110 .

[0032] Fig. 3 is a three-view diagram showing the configuration of a wireless power supply wall 100 according to one embodiment. Fig. 3 shows a front view, a side view, and a top view of the wireless power supply wall 100. As shown in Fig. 3, the wireless power supply wall 100 has a body 101, a power transmission electrode 110, and a protection panel 111.

[0033] The frame 101 is the main body of the wireless power supply wall 100 as a wall, and is an upright portion that stands upright on a floor surface such as a road surface 300. The frame 101 is formed using an insulating material such as concrete, and has a predetermined strength. Although not shown in FIG. 3 , the frame 101 may have a commercial power supply 120, a high-frequency power supply 130, a matching circuit 140, and the like installed or buried therein.

[0034] The power transmitting electrodes 110 are two parallel strip-shaped electrodes arranged one above the other and fitted into grooves formed in the body 101. The power transmitting electrodes 110 are made of a conductive metal such as SUS (Stainless Used Steel), aluminum, or copper, and pass a high-frequency alternating current through them to transmit power to the opposing power receiving electrode.

[0035] The protective panel 111 is a resin panel that protects the surface of the power transmitting electrode 110, and is fitted into a groove formed in the body 101 so as to cover the power transmitting electrode 110. The protective panel 111 is formed using an insulating resin such as acrylic, polycarbonate, or polyvinyl chloride, and the surface of the body 101 and the surface of the protective panel 111 are substantially flush with each other. The resin that forms the protective panel 111 may be transparent or translucent, for example. In this case, the power transmitting electrode 110 can be seen from the outside through the protective panel 111.

[0036] The wireless power supply wall 100 does not necessarily have to be configured as described above, and can also have a structure in which a power supply electrode made of thin copper foil is sandwiched between the main body and the protective panel, for example.

[0037] 4 is a block diagram showing the functions of a moving object 200 according to one embodiment. The moving object 200 shown in FIG. 4 includes a power receiving electrode 210, a matching circuit 220, a rectifier circuit 230, a DC / DC converter 240, a storage battery 250, and a control unit 260.

[0038] The power receiving electrode 210 is formed using a conductive metal, and receives power from the opposing power transmitting electrode by, for example, an electric field coupling method that generates a high frequency alternating current in response to an electric field.

[0039] The matching circuit 220 matches the impedance of the transmission path through which high-frequency power is transmitted, and causes a high-frequency current to flow through the power-receiving electrode 210 . The rectifier circuit 230 converts the high-frequency current flowing in the power receiving electrode 210 into a direct current. The DC / DC converter 240 converts the voltage of the direct current in accordance with the specifications of the storage battery 250. That is, the DC / DC converter 240 obtains a voltage suitable for charging the storage battery 250 from the direct current obtained by the rectifier circuit 230.

[0040] The storage battery 250 is charged using the voltage obtained by the DC / DC converter 240. That is, the storage battery 250 stores the power supplied from the wirelessly powered wall 100. The control unit 260 controls the operation of the moving body 200 using the power stored in the storage battery 250. Specifically, the control unit 260 drives the wheels 201 using the power, for example, to move the moving body 200.

[0041] FIG. 5 is a two-sided view showing the configuration of moving body 200 according to one embodiment. FIG. 5 shows a side view and a top view of moving body 200. However, the housing is not shown in the top view shown in FIG. 5. As shown in FIG. 5, moving body 200 is composed of main body 200B having wheels 201, expandable members 270, and links 280, and power receiving unit 200R having power receiving electrode 210. Power receiving unit 200R protrudes laterally from main body 200B. Hereinafter, the direction that passes through the side surface of moving body 200 perpendicular to the direction of movement of moving body 200 is referred to as the "vehicle width direction."

[0042] Two telescopic members 270, each capable of expanding and contracting in the vehicle width direction, are installed on the front and rear of the frame constituting main body 200B of moving body 200. Telescopic members 270 have a fixed part that is fixed to the frame of moving body 200 and a telescopic part that expands and contracts relative to the fixed part, and the telescopic part expands and contracts in the vehicle width direction to absorb displacement of power receiving unit 200R.

[0043] Specifically, the telescopic portion of telescopic member 270 is supported by the fixed portion via an elastic body such as a spring, and when no force is applied to the telescopic portion, it is extended to its maximum length due to the elastic force of the elastic body. When a force is applied from the tip of the telescopic portion toward the fixed portion, the telescopic portion is stored inside the fixed portion and shortened. Note that telescopic member 270 does not necessarily have to have this structure, and may be, for example, an oil damper in which the telescopic portion is supported by the fixed portion via a liquid such as oil, as long as it can absorb the displacement of power receiving unit 200R. One telescopic member 270 is installed on link 280, which has a structure in which two rod-shaped members connected by a hinge can open and close. In other words, the fixed portion of one telescopic member 270 is fixed to one of the rod-shaped members of link 280.

[0044] A power receiving unit 200R having a power receiving electrode 210 is attached to the tip of the extension / contraction portion of each extension / contraction member 270. Specifically, the tip of the extension / contraction portion of the extension / contraction member 270 protrudes laterally from the main body 200B, and is attached with the power receiving unit 200R formed by sandwiching the power receiving electrode 210 between the first panel 211 and the second panel 212. Therefore, when the moving object 200 moves while receiving power from the wireless power feeding wall 100, displacement in the vehicle width direction of the power receiving unit 200R that abuts against the wireless power feeding wall 100 can be absorbed. In other words, the distance between the power transmitting electrode 110 of the wireless power feeding wall 100 and the power receiving electrode 210 of the moving object 200 can be kept constant.

[0045] Link 280 has two rod-shaped members to which a fixed portion of expandable member 270 is attached, and this one rod-shaped member is openable and closable relative to the other rod-shaped member. Specifically, one end of one rod-shaped member on the power receiving unit 200R side serves as a fulcrum, and the other end opens and closes to adjust the angle of expandable member 270. That is, if the displacement of power receiving unit 200R cannot be fully absorbed even when the expandable portion of expandable member 270 is shortened to its shortest length, link 280 opens, changing the angle of expandable member 270, thereby further absorbing the displacement of power receiving unit 200R. Furthermore, it is possible to absorb the angular deviation of power receiving unit 200R with respect to wireless power supply wall 100 that occurs due to a positional deviation of moving object 200.

[0046] The power receiving unit 200R is formed by sandwiching the power receiving electrode 210 between a first panel 211 and a second panel 212. The first panel 211 and the second panel 212 are plate-like members formed using an insulating resin such as acrylic, polycarbonate, or polyvinyl chloride, and the first panel 211 is attached to the tip of an elastic portion of an elastic member 270. The power receiving electrode 210 is sandwiched between the first panel 211 and the second panel 212. The resin forming the first panel 211 and the second panel 212 may be transparent or translucent, for example. In this case, the power receiving electrode 210 can be seen from the outside through the first panel 211 or the second panel 212.

[0047] The power receiving electrodes 210 are two parallel strip-shaped electrodes arranged one above the other, and are made of a conductive metal such as SUS, aluminum, or copper. The power receiving electrodes 210 are provided in a position facing the power transmitting electrode 110 of the wireless power feeding wall 100 when the moving object 200 is adjacent to the wireless power feeding wall 100.

[0048] The power transmitting electrode 110 and the power receiving electrode 210 are both strip-shaped electrodes, but have different widths. That is, for example, the width of the power receiving electrode 210 is smaller than the width of the power transmitting electrode 110. Since the widths of the power transmitting electrode 110 and the power receiving electrode 210 are different in this way, even when the moving object 200 oscillates up and down while moving, the opposing area of ​​the power transmitting electrode 110 and the power receiving electrode 210 remains constant, thereby enabling stable wireless power feeding.

[0049] Rollers 213 are rotatably provided on the second panel 212 at positions that do not overlap with the power receiving electrode 210. That is, in Fig. 5, rollers 213 are provided at the four corners of the second panel 212. The rollers 213 have a cylindrical or spherical shape, and a portion of their surface protrudes outward from the surface of the second panel 212. The rollers 213 are provided rotatably around a rotation axis that extends at least in the vertical direction of the moving body 200. Note that if the rollers 213 have a spherical shape, the rollers 213 may be provided rotatably around the center of the sphere.

[0050] When the moving object 200 moves along the wireless power feeding wall 100, the rollers 213 rotate while contacting the wireless power feeding wall 100. Therefore, when the moving object 200 moves, the distance between the power transmitting electrode 110 and the power receiving electrode 210 can be kept constant, and wear due to friction on the surface of the wireless power feeding wall 100 and the surface of the second panel 212 can be prevented.

[0051] A guide 214 protrudes from the front of the power receiving unit 200R. The guide 214 continues from the surface of the second panel 212 and has a guide surface that curves toward the main body 200B. When the moving object 200 approaches the wireless power feeding wall 100, the guide 214 smoothly guides the power receiving unit 200R until the entire power receiving unit 200R abuts against the wireless power feeding wall 100, thereby preventing the power receiving unit 200R from colliding with the wireless power feeding wall 100. The guide 214 may be a single curved member formed integrally with the first panel 211 and the second panel 212, or may be divided into multiple curved members as shown in FIG. 5.

[0052] Next, wireless power feeding in the wireless power feeding system configured as above will be described with reference to FIGS.

[0053] 6 is a diagram seen from above showing the positional relationship between the wireless power supply wall 100 and the moving object 200 when the moving object 200 is moving. In FIG. 6, the moving object 200 is moving in the direction of the arrow in the drawing.

[0054] 6 , when the moving object 200 moves, the power receiving unit 200R comes into contact with the wireless power feeding wall 100. That is, the rollers 213 of the power receiving unit 200R come into contact with the surface that is flush with the protective panel 111 and the body 101 of the wireless power feeding wall 100. This defines the distance between the power transmitting electrode 110 and the power receiving electrode 210, and power is fed wirelessly from the power transmitting electrode 110 to the power receiving electrode 210.

[0055] At this time, the moving object 200 is set so as to move along the wireless power feeding wall 100 at a position where the power receiving unit 200R abuts against the wireless power feeding wall 100, not in a state where the extension portion of the extension member 270 is fully extended or fully retracted, but in a state where it can be extended or retracted. Therefore, because the power receiving unit 200R is attached to the tip of the extension portion of the extension member 270, even if the position of the main body 200B is shifted within the error range, the positional shift is absorbed by the extension and contraction of the extension member 270, and the power receiving unit 200R abuts against the wireless power feeding wall 100, and the distance between the power transmitting electrode 110 and the power receiving electrode 210 is kept constant. As a result, the efficiency of power transmission from the power transmitting electrode 110 to the power receiving electrode 210 is not reduced.

[0056] 7 is a diagram seen from above showing another positional relationship between the wireless power supply wall 100 and the moving object 200 when the moving object 200 is moving. In FIG. 7, the moving object 200 is moving in the direction of the arrow in the drawing.

[0057] As shown in FIG. 7 , when the moving object 200 moves, for example, the moving object 200 may meander within the error range of the positional accuracy, causing the moving object 200 to shift in position relative to the wireless power feeding wall 100. In the example shown in FIG. 7 , the front of the main body 200B is closer to the wireless power feeding wall 100 than the rear, and the wireless power feeding wall 100 and the main body 200B are no longer parallel. Even in this case, the expansion and contraction member 270 absorbs the displacement of the power receiving unit 200R caused by the positional deviation of the main body 200B, and the positional relationship between the power transmitting electrode 110 and the power receiving electrode 210 does not change. In other words, the expansion and contraction portion of the front expansion and contraction member 270 that approaches the wireless power feeding wall 100 is shortened, so that the power receiving unit 200R is not affected by the positional deviation of the main body 200B. Therefore, the distance between the power transmitting electrode 110 and the power receiving electrode 210 is kept constant, thereby improving power transmission efficiency.

[0058] Fig. 8 is a diagram seen from above showing yet another positional relationship between the wireless power supply wall 100 and the moving object 200 when the moving object 200 is moving. In Fig. 8, the moving object 200 is moving in the direction of the arrow in the figure.

[0059] As shown in Fig. 8, when the moving object 200 moves, for example, due to meandering of the moving object 200 within the error range of the positional accuracy, the positional deviation of the main body 200B relative to the wireless power feeding wall 100 may become larger than in the case shown in Fig. 7. In the example shown in Fig. 8, the rear of the main body 200B moves away from the wireless power feeding wall 100, and the front approaches the wireless power feeding wall 100. In this case, even if the front extensible member 270 is shortened to its shortest length, it may not be able to fully absorb the displacement of the power receiving unit 200R caused by the positional deviation of the main body 200B.

[0060] In such a case, the force applied from the power receiving unit 200R to the front expandable member 270 causes the link 280 to open, adjusting the angle of the expandable member 270 and further absorbing the displacement of the power receiving unit 200R. That is, one end of the link 280 close to the power receiving unit 200R serves as a fulcrum, and the other end opens, changing the angle of the rod-shaped member to which the front expandable member 270 is attached. This changes the angle of the front expandable member 270, absorbing the displacement of the power receiving unit 200R that cannot be absorbed by the expandable member 270 alone. This keeps the distance between the power transmitting electrode 110 and the power receiving electrode 210 constant, improving power transmission efficiency.

[0061] As described above, according to the present embodiment, the power receiving unit of a mobile object that moves along the wireless power feeding wall while receiving power from the wireless power feeding wall is attached to the tip of an extendable member that can extend and contract in the vehicle width direction of the mobile object. Therefore, when the mobile object moves with the power receiving unit in contact with the wireless power feeding wall, displacement of the power receiving unit in the vehicle width direction due to positional deviation of the mobile object can be absorbed. In other words, the distance between the power transmitting electrode of the wireless power feeding wall and the power receiving electrode of the mobile object can be kept constant, thereby improving power transmission efficiency.

[0062] (Variation) In the above embodiment, the power receiving unit 200R of the moving body 200 is described as protruding to the side of the main body 200B, but for example, when charging the storage battery 250 of the moving body 200 that is stopped by wireless power supply, the power receiving unit 200R may be made to protrude forward or backward from the main body 200B.

[0063] Fig. 9 is a diagram showing the positional relationship between the wireless power supply wall 100 and the stopped moving body 200 as viewed from above. In Fig. 9, the moving body 200 is charging the storage battery 250 by receiving wireless power supply from the wireless power supply wall 100. After the storage battery 250 is charged, the moving body 200 can move in the direction of the arrow in the figure.

[0064] As shown in Fig. 9, moving body 200 is composed of main body 200B' and power receiving unit 200R', with power receiving unit 200R' protruding rearward from main body 200B'. Extendable members 270 that are extendable in a direction parallel to the direction of movement are installed on the left and right sides of a frame that constitutes main body 200B' of moving body 200. These extendable portions of extendable members 270 have a fixed portion and an extendable portion that extends and contracts relative to the fixed portion, and the fixed portion is fixed to the frame of moving body 200, and the extendable portion extends and contracts in a direction parallel to the direction of movement.

[0065] A power receiving unit 200R' having a power receiving electrode 210 is attached to the tip of the extension / contraction portion of each extension / contraction member 270. Specifically, the tip of the extension / contraction portion of the extension / contraction member 270 protrudes rearward from the main body 200B', and is attached to the power receiving unit 200R' formed by sandwiching the power receiving electrode 210 between the first panel 211 and the second panel 212. Therefore, when the moving object 200 stops at a predetermined charging position near the wireless power feeding wall 100, even if the moving object 200 stops with a positional deviation within the error range of the positional accuracy, it is possible to absorb the displacement of the power receiving unit 200R' in the front-to-rear direction. In other words, it is possible to maintain a constant distance between the power transmitting electrode 110 of the wireless power feeding wall 100 and the power receiving electrode 210 of the moving object 200, thereby improving the power transmission efficiency.

[0066] In the above embodiment, the extendable member 270 is installed at two locations, one at the front and one at the rear of the main body 200B of the moving object 200. However, the installation locations of the extendable member 270 are not limited to this. That is, for example, as shown in FIG. 10 , the extendable member 270 can also be installed at one location, at the center of the main body 200B. Even in this case, the power receiving unit 200R can be attached to the tip of the extendable member 270, and displacement of the power receiving unit 200R in the vehicle width direction when in contact with the wireless power feeding wall 100 can be absorbed. In other words, the distance between the power transmitting electrode 110 of the wireless power feeding wall 100 and the power receiving electrode 210 of the moving object 200 can be kept constant, thereby improving power transmission efficiency.

[0067] In addition, in the above embodiment, the expandable member 270 is installed on the moving body 200 having the power receiving electrode 210, but it is also possible to install an expandable member on the wireless power feeding wall 100 having the power transmitting electrode 110.

[0068] Fig. 11 is a diagram showing the positional relationship between the wireless power feeding wall 100 and the moving body 200 when wireless power is being fed, as viewed from above. However, the housing is not shown in the top view shown in Fig. 11. As shown in Fig. 11, the moving body 200 is made up of a main body 200B having wheels 201 and support members 290, and a power receiving unit 200R having a power receiving electrode 210.

[0069] Support members 290 are installed on the front and rear of a frame that constitutes main body 200B of moving body 200. Unlike extensible member 270, support member 290 fixedly supports power receiving unit 200R attached to the tip.

[0070] The wireless power feeding wall 100 has a structure in which the body 101, the power transmitting electrode 110, and the protective panel 111 are separated from each other, and the power transmitting electrode 110 and the protective panel 111 are attached to the tip of an expandable member 150 fixed to the body 101. In the configuration shown in Fig. 11 , the power transmitting electrode 110 is two strip-shaped electrodes similar to Fig. 3 , and the protective panel 111 is a plate-shaped member that sandwiches the power transmitting electrode 110. The expandable member 150 has a fixed part that is fixed to the body 101 of the wireless power feeding wall 100 and an expandable part that expands and contracts relative to the fixed part, and the expandable part expands and contracts in the vehicle width direction to absorb displacement of the power transmitting electrode 110 and the protective panel 111.

[0071] Specifically, the telescopic portion of the telescopic member 150 is supported by the fixed portion via an elastic body such as a spring, and when a force is applied from the tip of the telescopic portion toward the fixed portion, the telescopic portion is retracted into the fixed portion and shortened. Note that the telescopic member 150 does not necessarily have to have this structure, and may be, for example, an oil damper in which the telescopic portion is supported by the fixed portion via a liquid such as oil, as long as it can absorb the displacement of the power transmitting electrode 110 and the protective panel 111. Also, although not shown in FIG. 11 , the telescopic member 150 may be installed on the main body 101 via a link having a structure similar to that of the link 280. That is, for example, the fixed portion of the telescopic member 150 may be attached to one rod-shaped member of the link, and the other rod-shaped member of the link may be fixed to the main body 101.

[0072] When the moving object 200 moves, the power receiving unit 200R comes into contact with the wireless power feeding wall 100. That is, the rollers 213 of the power receiving unit 200R come into contact with the surface of the protective panel 111 of the wireless power feeding wall 100. This defines the distance between the power transmitting electrode 110 and the power receiving electrode 210, and power is wirelessly fed from the power transmitting electrode 110 to the power receiving electrode 210. Because the power transmitting electrode 110 and the protective panel 111 are attached to the tip of the extension / contraction portion of the extension / contraction member 150, even if the position of the power receiving unit 200R of the moving object 200 is shifted within an error range, the positional shift is absorbed by the extension / contraction of the extension / contraction member 150, and the power receiving unit 200R comes into contact with the protective panel 111, thereby maintaining a constant distance between the power transmitting electrode 110 and the power receiving electrode 210. As a result, the efficiency of power transmission from the power transmitting electrode 110 to the power receiving electrode 210 is not reduced.

[0073] In this way, even when the power transmitting unit of the wireless power supply wall 100 is attached to the tip of the expandable member 150, the distance between the power transmitting electrode 110 and the power receiving electrode 210 is kept constant, thereby improving the power transmission efficiency. [Explanation of symbols]

[0074] 100 Wireless Power Wall 101 Body 110 Power transmission electrode 111 Protective Panel 150, 270 Elastic member 200 Mobile 200B, 200B' body 200R, 200R' power receiving unit 201 Wheels 210 Receiving electrode 211 Panel 1 212 Panel 2 213 Laura 214 Guide 280 Links 290 Support member

Claims

1. a power transmission unit provided on an upright portion that stands upright relative to a floor surface and having a power transmission electrode that wirelessly transmits power; a power receiving unit provided on a movable body and having a power receiving electrode that receives power from the power transmitting electrode when the power receiving unit is positioned opposite the power transmitting electrode; a displacement absorbing unit that absorbs displacement of the power transmitting unit or the power receiving unit that accompanies movement of the moving body; A wireless power supply system having the above configuration.

2. The displacement absorbing portion is an elastic member having a fixed portion fixed to the moving body and an elastic portion supported by the fixed portion via an elastic body and elastically expandable relative to the fixed portion; The power receiving unit is Attached to the tip of the expansion part The wireless power supply system according to claim 1 .

3. The displacement absorbing portion is The link further includes a first rod-shaped member fixed to the moving body, a second rod-shaped member that fixes the fixed portion of the expandable member, and a connecting member that connects the first rod-shaped member and the second rod-shaped member in an openable and closable manner. The wireless power supply system according to claim 2 .

4. The power receiving unit is A plate-shaped first panel attached to the tip of the stretchable portion; a plate-shaped second panel that sandwiches the power receiving electrode between itself and the first panel; and The wireless power supply system according to claim 2 ,

5. The power receiving unit is a roller member whose surface partly protrudes outward from the surface of the second panel and which rotates in a direction corresponding to the direction of movement of the moving body; The wireless power supply system according to claim 4 , further comprising:

6. The displacement absorbing portion is an elastic member having a fixed portion fixed to the erected portion and an elastic portion supported by the fixed portion via an elastic body and elastically stretchable relative to the fixed portion; The power transmission unit is Attached to the tip of the expansion part The wireless power supply system according to claim 1 .

7. a main body that moves using power wirelessly transmitted from the power transmitting electrode; an elastic member having a fixed portion fixed to the main body portion and an elastic portion supported by the fixed portion via an elastic body and elastically expandable relative to the fixed portion; a power receiving section having a power receiving electrode attached to a tip of the extension section and configured to receive power from the power transmitting electrode when the power receiving section is positioned opposite the power transmitting electrode; A mobile object having the above configuration.

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