Power transmission device, manufacturing method, and contactless power supply system

Abstract

A power transmission device (10) contactlessly supplies power to a mobile body (VE) which has a power reception coil (Lr). The power transmission device (10) comprises: a housing (30) disposed on a travel road surface (RS); and at least one power transmission coil (Ls) accommodated in the housing. The housing has a housing upper surface (32) that supports the mobile body, and an internal space (33) formed below the housing upper surface. The at least one power transmission coil (Ls) is disposed in the internal space, and the entire region of the housing upper surface is larger than the size of said at least one power transmission coil in a top view.

Description

Power transmission device, manufacturing method, and contactless power supply system CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Japanese Application No. 2024-503, filed on January 5, 2024, the contents of which are incorporated herein by reference.

[0002] The present disclosure relates to a power transmission device, a manufacturing method, and a contactless power supply system.

[0003] Conventionally, there is a system for contactlessly supplying power to an automated guided vehicle (for example, see Patent Document 1). In this system, a power transmitting coil is placed on the floor of the travel path. Power is supplied to a power receiving device at a position where the power receiving coil faces the power transmitting coil.

[0004] JP 2014-33524 A

[0005] The position of the power receiving coil in an automated guided vehicle varies depending on the specifications. Meanwhile, the width of the passageway in a facility where the automated guided vehicle travels may be limited to the width the automated guided vehicle can travel through. Therefore, when installing a power transmitting device in a facility, there is a demand for a power transmitting device whose power transmitting coil can be freely positioned to match the position of the power receiving coil.

[0006] The present disclosure can be realized in the following forms.

[0007] In one embodiment of the present disclosure, there is provided a power transmission device for contactlessly supplying power to a moving object having a power receiving coil, the power transmission device including: a housing arranged on a road surface; and at least one power transmission coil housed in the housing, the housing having a housing top surface supporting the moving object and an internal space formed below the housing top surface, the at least one power transmission coil disposed in the internal space, and the entire area of ​​the housing top surface being larger than the size of the at least one power transmission coil when viewed from above.

[0008] According to this embodiment, the power transmitting device can be easily installed by placing the housing on the road surface. Furthermore, since the entire area of ​​the top surface of the housing is larger than the size of at least one power transmitting coil in a top view, the position of the power transmitting coil relative to the housing can be adjusted. Therefore, the position of the power transmitting coil can be freely arranged to match the position of the power receiving coil.

[0009] In a second aspect of the present disclosure, there is provided a method for manufacturing a power transmission device that wirelessly supplies power to a moving object having a power receiving coil, the method comprising: a first step of preparing an unadjusted housing including: (a) a housing having a lower surface, an upper surface disposed above the lower surface, and an internal space defined by the lower surface and the upper surface; and (b) a plurality of support members disposed between the lower surface and the upper surface of the housing for supporting the upper surface of the housing, the plurality of support members filling the internal space; a second step of marking, on the unadjusted housing, a position on the lower surface of the housing that faces the power receiving coil when the moving object travels along a predetermined movement path; and a third step of removing, from the internal space, some of the support members that are disposed at the facing positions.

[0010] According to this embodiment, the power transmitting coil can be positioned to match various positions of the power receiving coil relative to the movement path, so that a power transmitting device can be provided that suppresses positional deviation of the power transmitting coil relative to the power receiving coil.

[0011] In a third aspect of the present disclosure, there is provided a contactless power transfer system for contactlessly transferring power to a moving body having a power receiving coil, the contactless power transfer system including a first power transmission device and a second power transmission device different from the first power transmission device, wherein each of the first power transmission device and the second power transmission device includes a housing arranged on a road surface on which the moving body is traveling and at least one power transmission coil housed in the housing, the housing having a lower surface arranged along the road surface and an upper surface arranged above the lower surface and supporting the moving body, and an internal space defined by the lower surface and the upper surface, the at least one power transmission coil being disposed in the internal space, the size of the housing of the first power transmission device being the same as the size of the housing of the second power transmission device, and a position of the at least one power transmission coil of the first power transmission device on the lower surface of the housing different from a position of the at least one power transmission coil of the second power transmission device on the lower surface of the housing.

[0012] According to this embodiment, the position of the power transmission coil of the first power transmission device on the underside of the housing is different from the position of the power transmission coil of the second power transmission device on the underside of the housing, and thus it is possible to provide a power transmission device that uses a common housing and is compatible with two types of power receiving devices, each having a power receiving coil at a different position relative to the movement path.

[0013] The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. The drawings are as follows: Figure 1 is a diagram explaining a contactless power supply system; Figure 2 is a plan view showing the layout of a warehouse; Figure 3 is a bottom view showing the bottom of an automatic guided vehicle; Figure 4 is a circuit diagram of a contactless power supply system; Figure 5 is an oblique view showing the structure of a power transmission device; Figure 6 is a side view showing the power transmission device excluding the side; Figure 7 is a plan view showing the power transmission device excluding the top surface of the housing; Figure 8 is a flowchart of a manufacturing process for a power transmission device; Figure 9 is a diagram explaining a manufacturing method for a power transmission device; Figure 10 is a circuit diagram of a power transmission device of a second embodiment; Figure 11 is a plan view showing the power transmission device of the second embodiment excluding the top surface of the housing; Figure 12 is a flowchart of a manufacturing process for a power transmission device of the second embodiment; Figure 13 is a plan view showing the layout of a warehouse of a third embodiment; Figure 14 is a plan view showing the first power transmission device and the second power transmission device excluding the top surfaces of the housing; and Figure 15 is a circuit diagram of another embodiment of a power transmission resonant circuit.

[0014] A. First Embodiment: A1. Overview of Contactless Power Transfer System: As shown in FIG. 1 , the contactless power transfer system 1 includes a management device 3, a power transmission device 10, and a power receiving device 80. The power transmission device 10 wirelessly supplies power to the power receiving device 80. In this embodiment, the contactless power transfer system 1 is placed in a warehouse. The power transmission device 10 is placed on a floor surface RS that serves as a travel surface of the warehouse. The power receiving device 80 is mounted on an automatic guided vehicle VE that serves as a mobile body that travels on the floor surface RS. The automatic guided vehicle VE is an automatic guided vehicle (AGV) that transports a load LO. The automatic guided vehicle VE travels according to instructions from the management device 3.

[0015] As shown in Figure 2, the warehouse is provided with a load placement area AE1 and a work area AE2. The load placement area AE1 is an area where loads LO are arranged. The work area AE2 is an area where an automated guided vehicle VE carrying a load LO stops so that a worker OP can work there. The automated guided vehicle VE travels along a predetermined travel route RO.

[0016] As shown in FIG. 1 , the load LO has a shelf and cargo stored on the shelf. The automated guided vehicle VE transports the target load LO and stops at the working area AE2. The operator OP removes the target cargo from the load LO stopped in the working area AE2. Alternatively, the operator OP places the target cargo into the load LO stopped in the working area AE2. The automated guided vehicle VE then moves to the load placement area AE1.

[0017] The power transmitting coil Ls is arranged along the movement route RO. In this embodiment, the power transmitting coil Ls is arranged in the working area AE2. Therefore, it is possible to wirelessly supply power from the power transmitting device 10 to the power receiving device 80 by utilizing the period when the worker OP is working to take out or put away luggage.

[0018] The automated guided vehicle VE travels along a plurality of position markers MK arranged on the floor surface RS. In this embodiment, the position markers MK are visible marks. For example, a two-dimensional code can be used as the position markers MK. The position markers MK include coordinate information.

[0019] As shown in FIG. 3 , the automated guided vehicle VE includes multiple wheels 90, an opening 94, and a marker sensor 95. The directions shown in FIG. 3 are based on the automated guided vehicle VE. The multiple wheels 90 include a pair of drive wheels 92 and a pair of steering wheels 93. The pair of drive wheels 92 are located at the center of the automated guided vehicle VE in the longitudinal direction and at each of the left and right ends. The pair of drive wheels 92 rotate by driving force transmitted from a motor generator (not shown). This causes the automated guided vehicle VE to move forward or backward. The pair of drive wheels 92 and the pair of steering wheels 93 are driven in accordance with commands from a control circuit 86 (described later). The pair of steering wheels 93 are located at each of the longitudinal ends of the automated guided vehicle VE. The pair of steering wheels 93 are also located point-symmetrically with respect to the center of the automated guided vehicle VE. When the automated guided vehicle VE turns, a difference in rotation speed is generated between the pair of drive wheels 92. Furthermore, when the automatic guided vehicle VE turns, the two drive wheels 92 of the pair of drive wheels 92 rotate in different directions.

[0020] The opening 94 is disposed at the center of the bottom surface of the automatic guided vehicle VE. The marker sensor 95 is disposed at the center of the opening 94. The marker sensor 95 includes a camera. The marker sensor 95 captures an image of the position marker MK and acquires information contained in the position marker MK.

[0021] A2. Electrical Configuration of the Contactless Power Transfer System: As shown in Fig. 4, the power transmission device 10 has, in addition to the power transmission coil Ls, a power supply circuit 11 as an electric circuit and a power transmission circuit 12 as an electric circuit. The power supply circuit 11 and the power transmission circuit 12 are circuits for supplying power to the power transmission coil Ls.

[0022] The power supply circuit 11 includes an AC / DC converter 14 and an inverter 15. The AC / DC converter 14 converts commercial power supplied from the power supply system GP into a DC voltage of a desired voltage. The inverter 15 converts the DC voltage supplied from the AC / DC converter 14 into an AC voltage of an operating frequency. The power supply circuit 11 is controlled by a control circuit 16, which will be described later.

[0023] The power transmitting circuit 12 includes a power transmitting resonant capacitor Cs as a resonant capacitor, a first switch SW1, a control circuit 16, and a communication unit 17. The power transmitting resonant capacitor Cs is electrically connected to the power transmitting coil Ls. The power transmitting resonant capacitor Cs includes a first power transmitting capacitor Cs1 and a second power transmitting capacitor Cs2. The power transmitting resonant capacitor Cs has a capacitance value that is changeable between a first capacitance value and a second capacitance value that is larger than the first capacitance value. The capacitance value of the first power transmitting capacitor Cs1 is larger than the capacitance value of the second power transmitting capacitor Cs2. The first switch SW1, the first power transmitting capacitor Cs1, and the power transmitting coil Ls are connected in series in this order. The second power transmitting capacitor Cs2 is connected in parallel to the connection between the first switch SW1 and the first power transmitting capacitor Cs1.

[0024] The first switch SW1 is a bidirectional switch in which the source electrodes of two transistors are connected. A switching signal Sig1 is input to the first switch SW1 from the control circuit 16. When a high-level switching signal Sig1 is input to the first switch SW1, the first switch SW1 is turned on, causing a current to flow through the first power transmitting capacitor Cs1. The combined capacitance of the first power transmitting capacitor Cs1 and the second power transmitting capacitor Cs2 and the inductance of the power transmitting coil Ls are set to values ​​that create a resonance state at the operating frequency. When the first switch SW1 is turned on, the first power transmitting capacitor Cs1, the second power transmitting capacitor Cs2, and the power transmitting coil Ls form a power transmitting resonant circuit 13, which is a series resonant circuit. When a low-level switching signal Sig1 is input to the first switch SW1, the first switch SW1 is turned off, causing the first power transmitting capacitor Cs1 to become non-conductive. The resonant frequency of the resonant circuit formed by the second power transmitting capacitor Cs2 and the power transmitting coil Ls in the conductive state deviates from the operating frequency. Furthermore, because the capacitance value of the second power transmitting capacitor Cs2 is smaller than the capacitance value of the first power transmitting capacitor Cs1, when the first switch SW1 is in the non-conductive state, the impedance of the power transmitting circuit 12 with respect to the input AC power increases, and the current flowing through the power transmitting resonant circuit 13 is suppressed. The above-mentioned first capacitance value is the capacitance value of the power transmitting resonant capacitor Cs when the first switch SW1 is in the non-conductive state. The above-mentioned second capacitance value is the capacitance value of the power transmitting resonant capacitor Cs when the first switch SW1 is in the conductive state.

[0025] The communication unit 17 is communicably connected to the control circuit 16. The communication unit 17 has a wireless communication antenna (not shown) and performs wireless communication with a communication unit 87 (described later) of the power receiving device 80.

[0026] The power receiving device 80 includes a power receiving circuit 82 in addition to the power receiving coil Lr and marker sensor 95. The power receiving circuit 82 includes a power receiving capacitor Cr, a rectifier circuit 84, a battery 85, a control circuit 86, and a communication unit 87. The power receiving capacitor Cr is connected in series with the power receiving coil Lr. The power receiving coil Lr and the power receiving capacitor Cr form a power receiving resonant circuit 83, which is a series resonant circuit. The rectifier circuit 84 rectifies the AC power received by the power receiving resonant circuit 83 and supplies the rectified DC power to a battery 85. The battery 85 stores the supplied power. Power is supplied from the battery 85 to the motor generator.

[0027] The communication unit 87 and the marker sensor 95 are each connected to the control circuit 86 so as to be able to communicate with each other. The communication unit 87 has an antenna for wireless communication (not shown), and performs wireless communication with the communication unit 17 of the power transmission device 10 and the management device 3.

[0028] When AC power is supplied to the power transmitting coil Ls, magnetic field resonance between the power transmitting coil Ls and the power receiving coil Lr causes power to be contactlessly supplied to the power receiving device 80. As described above, the AC power output from the power receiving resonance circuit 83 is rectified by the rectifier circuit 84 and supplied to the battery 85.

[0029] The control circuit 16 sets the power transmitting coil Ls to either a standby state or a power supply state. Specifically, the standby state is a state in which the first switch SW1 is set to a non-conductive state, thereby setting the power transmitting resonant circuit 13 to a non-resonant state. In contrast, the power supply state is a state in which the first switch SW1 is set to a conductive state, thereby setting the power transmitting resonant circuit 13 to a resonant state, and a power supply current flows to the power transmitting coil Ls. In the power supply state, the current flowing through the power transmitting coil Ls is larger than the current flowing through the power transmitting coil Ls in the standby state.

[0030] In this embodiment, when the automatic guided vehicle VE is located in the working area AE2, the power transmission device 10 sets the power transmission coil Ls to a power supply state. This allows the power transmission device 10 to save power.

[0031] The management device 3 commands the target automated guided vehicle VE to move to the working area AE2. When commanded by the management device 3, the automated guided vehicle VE detects the position marker MK with the marker sensor 95 and moves to the working area AE2 along the movement route RO specified by the management device 3. When the automated guided vehicle VE enters the working area AE2, the power receiving device 80 transmits a signal to the power transmitting device 10 instructing it to start power transmission. When the power transmitting device 10 receives the signal instructing it to start power transmission, it switches the power transmitting resonant circuit 13 from a standby state to a power feeding state. As a result, power is wirelessly fed to the power receiving device 80.

[0032] When the worker OP finishes the work, the management device 3 commands the power receiving device 80 to move to the load placement area AE1. When commanded by the management device 3, the power receiving device 80 transmits a signal to the power transmitting device 10 instructing it to end power transmission. When the power transmitting device 10 receives the signal instructing it to end power transmission, it switches the power transmitting resonant circuit 13 from a power supply state to a standby state. The automated guided vehicle VE moves to the load placement area AE1 along the movement route RO specified by the management device 3 by detecting the position marker MK with the marker sensor 95.

[0033] The conditions for the power transmitter resonant circuit 13 to switch between the standby state and the power supply state are not limited to those described above. In another embodiment, the power transmitter resonant circuit 13 may switch from the standby state to the power supply state without communicating with the management device 3, provided that the power transmitter 10 detects that the power receiving device 80 is located within a range where wireless power supply is possible. Specifically, when the power receiving coil Lr, which generates magnetic flux, approaches the power transmitting coil Ls and enters the range where wireless power supply is possible, the magnetic flux interlinked with the power transmitting coil Ls increases. Therefore, the power transmitter resonant circuit 13 may switch from the standby state to the power supply state by detecting a change in the magnitude of the magnetic flux interlinked with the power transmitting coil Ls. The power transmitter 10 may also include a separate magnetic flux detection coil instead of the power transmitting coil Ls to detect the change in magnetic flux magnitude. The change in magnetic flux magnitude can be detected as a change in voltage or current.

[0034] A3. Structure of the Power Transmission Device: As shown in FIG. 5 , the power transmission device 10 includes a housing 30 and a plurality of support members 38 in addition to the above configuration. The housing 30 houses the power transmission coil Ls. The housing 30 has a housing bottom surface 31, a housing top surface 32, and an internal space 33. As shown in FIG. 6 , the housing top surface 32 is disposed vertically above the housing bottom surface 31. The internal space 33 is formed below the housing top surface 32. The internal space 33 is a space defined by the housing bottom surface 31 and the housing top surface 32. The power transmission coil Ls, the power supply circuit 11, the power transmission circuit 12, and a plurality of support members 38 are disposed within the internal space 33. In the following description, the power transmission coil Ls, the power supply circuit 11, and the power transmission circuit 12 may be collectively referred to as "mounted components."

[0035] 7, the components are arranged so as not to overlap each other in the vertical direction, which allows the thickness of the power transmission device 10 in the vertical direction to be reduced.

[0036] As shown in FIG. 6 , the housing upper surface 32 includes an upper surface main body portion 32a and two upper surface inclined portions 32b. The two upper surface inclined portions 32b are arranged opposite each other with the upper surface main body portion 32a in between. The upper surface main body portion 32a is arranged substantially parallel to the housing lower surface 31. In contrast, the two upper surface inclined portions 32b are arranged at an angle relative to the housing lower surface 31. The housing lower surface 31 is arranged on and along the floor surface RS. This allows for easy installation of the power transmission device 10. The housing upper surface 32 supports the automated guided vehicle VE. Specifically, the automated guided vehicle VE travels on the housing upper surface 32. The upper surface main body portion 32a is located vertically above the floor surface RS. The two upper surface inclined portions 32b function as slopes for the automatic guided vehicle VE to ascend to the upper surface main body portion 32a, or as slopes for the automatic guided vehicle VE to descend from the upper surface main body portion 32a.

[0037] 7 , the total area of ​​the housing bottom surface 31 and the housing top surface 32 is larger than the size of the power transmitting coil Ls when viewed from above. Furthermore, in this embodiment, the total area of ​​the housing top surface 32 is larger than the size of the power transmitting coil Ls when viewed from above, plus the size of the power supply circuit 11 and the size of the power transmitting circuit 12 when viewed from above. This improves the degree of freedom in arranging the power transmitting coil Ls, the power supply circuit 11, and the power transmitting circuit 12 in the housing 30. Note that the "size when viewed from above" refers to the size of the components when viewed from above the housing top surface 32 down along the normal direction of the housing bottom surface 31.

[0038] The system power supply GP and the power supply circuit 11 are electrically connected by a cable 25 serving as wiring. The power supply circuit 11 and the power transmission circuit 12 are electrically connected by the cable 25. The power transmission circuit 12 and the power transmission coil Ls are electrically connected by the cable 25.

[0039] The plurality of support members 38 are disposed below the housing top surface 32, specifically between the housing bottom surface 31 and the housing top surface 32, to support the housing top surface 32. In this embodiment, the support members 38 are cylindrical. In this embodiment, the support members 38 are made of an elastomer. This reduces vibrations that occur when the automated guided vehicle VE travels over the power transmission device 10. The shape and material of the support members 38 are not limited to this. The plurality of support members 38 are disposed in an area of ​​the entire housing top surface 32, excluding an area on the housing top surface 32 occupied by the power transmission coil Ls and an area on the housing top surface 32 occupied by the electrical circuit. This improves the strength of the housing top surface 32 against loads. The "occupied area" refers to the area of ​​the shadow of the placement member when the placement member is projected onto the housing top surface 32 along the normal direction of the housing bottom surface 31.

[0040] The size of the power transmitting coil Ls in a top view is set to correspond to a unit area LR, which is obtained by dividing the entire area of ​​the lower surface 31 of the housing into a plurality of units. In this embodiment, the unit area LR is a square. Specifically, the length of the long side of the power transmitting coil Ls is an integer multiple of the length of one side of the unit area LR, and the length of the short side of the power transmitting coil Ls is an integer multiple of the length of one side of the unit area LR. The power transmitting coil Ls is formed by winding a coil wire. The size of the power transmitting coil Ls refers to the size of a rectangle that encloses and contacts the power transmitting coil Ls. The power transmitting coil Ls is not limited to being formed by winding a coil wire, and may be formed by printed wiring on a printed circuit board. In this case, the size of the power transmitting coil Ls refers to the size of the printed circuit board on which the power transmitting coil Ls is formed.

[0041] The size of the power supply circuit 11 in a top view is set to be an area with the unit region LR as a unit. Specifically, the length of the long side of the power supply circuit 11 is an integer multiple of the length of one side of the unit region LR, and the length of the short side of the power supply circuit 11 is an integer multiple of the length of one side of the unit region LR. In this embodiment, the size of the power supply circuit 11 refers to the size of a rectangle that includes and contacts a substrate on which the electrical components that make up the power supply circuit 11 are mounted.

[0042] The size of the power transmitting circuit 12 in a top view is set to be an area with the unit area LR as a unit. Specifically, the length of each side of the power transmitting circuit 12 is an integer multiple of the length of one side of the unit area LR. In this embodiment, the size is a rectangle that encompasses and contacts a substrate on which electrical components that make up the power transmitting circuit 12 are mounted. By setting the size of the power transmitting coil Ls, the power supply circuit 11, and the power transmitting circuit 12 to be units of the unit area LR, it becomes easier to adjust the positions of the components relative to the bottom surface 31 of the housing.

[0043] Furthermore, each support member 38 is arranged in a unit region LR. This allows the support members 38 to be arranged in the entire area of ​​the housing bottom surface 31, excluding the area where the components are arranged. Therefore, when a load is applied to the housing top surface 32, the housing top surface 32 can be supported by the multiple support members 38, thereby improving the strength of the power transmission device 10.

[0044] As shown in FIG. 2 , in this embodiment, the automated guided vehicle VE travels straight over the power transmission device 10. Therefore, as shown in FIG. 7 , when the automated guided vehicle VE travels along the travel path RO, the path LT drawn by the wheels 90 is a straight line. The support member 38 is disposed in a position overlapping the path LT in a top view. The power transmission coil Ls and the electrical circuit are disposed in a position excluding the path LT in a top view. Therefore, when the automated guided vehicle VE travels over the housing top surface 32, the load on the mounted components can be reduced, and the strength of the housing top surface 32 of the power transmission device 10 can be improved when a load is applied thereto.

[0045] A4. Manufacturing method of power transmission device: In a warehouse, the width of the passageway that serves as the travel route RO along which the automated guided vehicle VE travels is limited to the width at which the automated guided vehicle VE can travel. Furthermore, the position of the power receiving coil Lr on the automated guided vehicle VE varies depending on the specifications. Therefore, it is necessary to position the power transmission coil Ls in accordance with the position of the power receiving coil Lr. In the manufacturing process for realizing the manufacturing method of the power transmission device 10, which will be described next, a device is implemented to position the power transmission coil Ls in accordance with the position of the power receiving coil Lr.

[0046] In a first step S1 of Fig. 8, a pre-adjusted housing 130 is prepared. As shown in Fig. 9, the pre-adjusted housing 130 has a housing 30 and a plurality of support members 38. The main difference between the power transmission device 10 and the pre-adjusted housing 130 is that the power transmission device 10 has components arranged therein, whereas the pre-adjusted housing 130 does not have components arranged therein. The internal space 33 of the pre-adjusted housing 130 is filled with support members 38. The support members 38 are arranged in the unit regions LR.

[0047] In a second step S2 of FIG. 8 , a facing position 131, which is a position on the bottom surface 31 of the housing that faces the power receiving coil Lr of the power transmission device 10 to be the power transmission target, and a position on the bottom surface 31 of the housing that faces the track LT, are marked on the pre-adjustment housing 130. As shown in FIG. 9 , in this embodiment, the pre-adjustment housing 130 is actually placed on the movement route RO of the warehouse, and an automatic guided vehicle VE is placed above the pre-adjustment housing 130, so that the facing position 131 and the position of the track LT are marked on the pre-adjustment housing 130. In FIG. 9 , the position of the track LT is not illustrated. Note that the method of actually placing the pre-adjustment housing 130 is not limited thereto; for example, the facing position 131 and the position of the track LT may be marked on the pre-adjustment housing 130 by comparing a drawing of the warehouse with a drawing of the automatic guided vehicle VE.

[0048] 8 , among the plurality of support members 38 packed in the pre-adjustment housing 130, some of the support members 38 arranged at the opposing positions 131 are removed from the internal space 33, and the power transmitting coil Ls is arranged at the opposing positions 131. In step S4, the positions of the power supply circuit 11 and the power transmitting circuit 12 are determined in any region of the housing bottom surface 31 excluding the position facing the track LT.

[0049] In step S5, the support member 38 arranged in the determined arrangement position is removed from the internal space 33, and then the power supply circuit 11 and the power transmission circuit 12 are arranged on the housing bottom surface 31. Thereafter, the power transmission coil Ls, the power transmission circuit 12, and the power supply circuit 11 are electrically connected to one another by the cable 25, the housing top surface 32 is fixed, and the power transmission device 10 is completed.

[0050] According to the first embodiment described above, the power transmission device 10 includes a housing 30 and a power transmission coil Ls. The housing 30 has a housing top surface 32 and an internal space 33. The power transmission coil Ls is disposed within the internal space 33. The entire area of ​​the housing top surface 32 is larger than the size of the power transmission coil Ls when viewed from above. Therefore, the power transmission device 10 can be easily installed by placing the housing 30 on a floor surface RS. Furthermore, because the entire area of ​​the housing top surface 32 is larger than the size of the power transmission coil Ls when viewed from above, the position of the power transmission coil Ls with respect to the housing 30 can be adjusted. Therefore, the position of the power transmission coil Ls can be freely arranged to match the position of the power receiving coil Lr.

[0051] The power transmission device 10 also includes a power supply circuit 11 and a power transmission circuit 12, which are arranged in the internal space 33, and a plurality of support members 38. The power supply circuit 11 and the power transmission circuit 12 are circuits for supplying power to the power transmission coil Ls. The plurality of support members 38 are arranged in an area of ​​the entire area of ​​the housing top surface 32, excluding an area on the housing top surface 32 occupied by the power transmission coil Ls and an area on the housing top surface 32 occupied by the power supply circuit 11 and the power transmission circuit 12. Because the plurality of support members 38 are arranged in an area excluding the power transmission coil Ls, the power supply circuit 11, and the power transmission circuit 12, the strength of the power transmission device 10 can be improved when a load is applied to the housing top surface 32.

[0052] Furthermore, since the power supply circuit 11 is disposed in the internal space 33, the power transmission device 10 can be disposed more easily than when the power supply circuit 11 is disposed outside the housing 30. Furthermore, since the power transmission circuit 12 including the power transmission resonant capacitor Cs is disposed in the internal space 33, the power transmission device 10 can be disposed more easily than when the power transmission circuit 12 is disposed outside the housing 30.

[0053] The power transmitting resonant capacitor Cs includes a first power transmitting capacitor Cs1 and a second power transmitting capacitor Cs2. The control circuit 16 switches the capacitance of the power transmitting resonant capacitor Cs between a first capacitance and a second capacitance, thereby switching the state of the power transmitting coil Ls between a power feeding state and a standby state. This allows the state of the power transmitting coil Ls to be switched by changing the capacitance of the power transmitting resonant capacitor Cs.

[0054] Furthermore, the size of the power transmission coil Ls in a top view is set to be a size in units of unit regions LR. Each of the multiple support members 38 is arranged in a unit region LR. This allows the multiple support members 38 to be arranged in an area of ​​the housing bottom surface 31 excluding the power transmission coil Ls. Therefore, when a load is applied to the housing top surface 32, the multiple support members 38 can support the housing top surface 32, thereby improving the strength of the power transmission device 10. Furthermore, the arrangement position of the power transmission coil Ls on the housing bottom surface 31 can be determined to suit the unit region LR, thereby improving the manufacturing efficiency of the power transmission device 10.

[0055] Furthermore, the size of the power supply circuit 11 is set so that the size of the power supply circuit 11 in a top view corresponds to an area defined by the unit area LR. This allows a plurality of support members 38 to be arranged in the area of ​​the housing bottom surface 31 excluding the power supply circuit 11. Therefore, when a load is applied to the housing top surface 32, the housing top surface 32 can be supported by the plurality of support members 38, thereby improving the strength of the power transmission device 10.

[0056] The power transmitting coil Ls is arranged along the travel route RO of the automatic guided vehicle VE. This allows contactless power transfer with the power transmitting coil Ls and the power receiving coil Lr overlapping each other, improving power transfer efficiency.

[0057] Furthermore, the support member 38 is disposed at a position overlapping the track LT in a top view when the automated guided vehicle VE travels along the travel path RO. The power transmission coil Ls, the power supply circuit 11, and the power transmission circuit 12 are disposed at positions excluding the track LT in a top view. This reduces the load on the power transmission coil Ls, the power supply circuit 11, and the power transmission circuit 12, and improves the strength of the housing top surface 32 of the power transmission device 10 when a load is applied thereto.

[0058] The manufacturing method for the power transmitting device 10 also includes a first step S1, a second step S2, and a third step S3. In the first step S1, a pre-adjusted housing 130 is prepared. In the second step S2, a facing position 131 on the housing bottom surface 31 facing the power receiving coil Lr is marked on the pre-adjusted housing 130. In the third step S3, some of the support members 38 packed in the pre-adjusted housing 130 and positioned at the facing position 131 are removed from the internal space 33, and the power transmitting coil Ls is positioned at the facing position 131. Therefore, when the housing 30 is positioned on the movement path RO, the power transmitting coil Ls can be positioned in accordance with the position of the power receiving coil Lr, thereby providing a power transmitting device 10 in which positional deviation of the power transmitting coil Ls with respect to the power receiving coil Lr is suppressed.

[0059] B. Second Embodiment: The main difference between a power transmitting device 210 of this embodiment and the power transmitting device 10 of the first embodiment is that the power transmitting device 210 includes two power transmitting resonance circuits 13. The same configurations and processing steps as those of the above embodiment are denoted by the same reference numerals, and detailed descriptions thereof will be omitted as appropriate.

[0060] As shown in Fig. 10 , the power transmitting device 210 includes two power transmitting resonant circuits 13. To distinguish between the two power transmitting resonant circuits 13, one is referred to as a first power transmitting resonant circuit 13A and the other is referred to as a second power transmitting resonant circuit 13B. The first power transmitting resonant circuit 13A includes two first power transmitting capacitors Cs1. The two first power transmitting capacitors Cs1 are connected in series. The second power transmitting resonant circuit 13B is the same as the power transmitting resonant circuit 13 of the first embodiment, and therefore a description thereof will be omitted.

[0061] The first power transmitter resonant circuit 13A and the second power transmitter resonant circuit 13B are connected in parallel to the power supply circuit 11. In this embodiment, the first power transmitter resonant circuit 13A and the second power transmitter resonant circuit 13B are set to a power supply state at the same time, thereby enabling power to be supplied to two automatic guided vehicles VE at the same time.

[0062] In the first embodiment, the positions of the electrical components that make up the power transmission circuit 12 are fixed relative to one another, and the power transmission circuit 12 is housed as a whole in the housing 30. Specifically, the power transmission circuit 12 is formed on a board, and this board is housed in the housing 30. In contrast, in the present embodiment, the multiple electrical components that make up the power transmission circuit 12 are arranged individually. For convenience, the cables 25 that electrically connect the electrical components are not shown in Figure 11.

[0063] 11 , the size of the first switch SW1 in a top view is set to be an area with the unit area LR as a unit. The sizes of the other electrical components constituting the power transmitting resonant circuit 13, that is, the first power transmitting capacitor Cs1, the second power transmitting capacitor Cs2, the control circuit 16, and the communication unit 17, in a top view are set similarly.

[0064] The power transmitting coil Ls of the first power transmitting resonant circuit 13A and the power transmitting coil Ls of the second power transmitting resonant circuit 13B are arranged side by side along the travel route RO, thereby enabling contactless power supply to two automatic guided vehicles VE at the same time.

[0065] As shown in FIG. 11 , the distance from the power supply circuit 11 to the power transmission coil Ls of the first power transmission resonant circuit 13A is shorter than the distance from the power supply circuit 11 to the power transmission coil Ls of the second power transmission resonant circuit 13B. Therefore, the parasitic impedance of the cable 25 from the power supply circuit 11 to the power transmission coil Ls of the first power transmission resonant circuit 13A is smaller than the parasitic impedance of the cable 25 from the power supply circuit 11 to the power transmission coil Ls of the second power transmission resonant circuit 13B. Therefore, the first power transmission resonant circuit 13A is provided with two first power transmission capacitors Cs1 to compensate for the impedance and adjust the first power transmission resonant circuit 13A to resonate at the operating frequency. In other words, one of the two first power transmission capacitors Cs1 is a compensation capacitor. Here, the two first power transmission capacitors Cs1 have the same capacitance value. In this way, by using first power transmission capacitors Cs1 of the same capacitance and adjusting the number of capacitors Cs1 to be arranged, the work efficiency of manufacturing the power transmission device 10 can be improved.

[0066] As shown in FIG. 12, similarly to the first embodiment, after the steps up to the third step S3 are performed, the position of the power supply circuit 11 on the housing bottom surface 31 is determined in the fourth step S14.

[0067] In a fifth step S15, it is determined whether the length of the cable 25, which serves as the wiring from the power supply circuit 11 to the power transmitting coil Ls, is shorter than a predetermined reference wiring length. If it is determined that the length of the cable 25 is shorter than the predetermined reference wiring length, it is determined in a sixth step S16 that a plurality of first power transmitting capacitors Cs1, each serving as a reference capacitor with a predetermined reference capacitance, be disposed as the power transmitting resonant capacitor Cs. The reference wiring length is a length that allows the power transmitting resonant circuit 13 to be set in a resonant state when one first power transmitting capacitor Cs1 is disposed, and is determined in advance by experiment. If it is determined that the length of the cable 25 is not shorter than the predetermined reference wiring length, the process proceeds to a seventh step S17.

[0068] In a seventh step S17, the support members 38 in the planned areas where the power supply circuit 11 and the power transmitting resonant circuit 13 are to be placed are removed from the internal space 33, and the power supply circuit 11 and the power transmitting resonant circuit 13 are placed in the planned areas.

[0069] In the case of the power transmitting device 210 shown in Fig. 11 , for the second power transmitting resonant circuit 13B, the length of the cable 25 is not shorter than the reference wiring length. For the first power transmitting resonant circuit 13A, the length of the cable 25 is shorter than a predetermined reference wiring length. In this embodiment, the reference capacitor arranged for compensation is the first power transmitting capacitor Cs1. In another embodiment, the reference capacitor arranged for compensation may be the second power transmitting capacitor Cs2.

[0070] The second embodiment described above provides the same effects as the first embodiment. Furthermore, the size of the first power transmitting capacitor Cs1 in a top view is set to correspond to an area defined by the unit area LR. The size of the second power transmitting capacitor Cs2 in a top view is set to correspond to an area defined by the unit area LR. This allows the multiple support members 38 to be arranged in an area of ​​the housing bottom surface 31 excluding the power transmitting resonant capacitor Cs. Therefore, when a load is applied to the housing top surface 32, the multiple support members 38 can support the housing top surface 32, thereby improving the strength of the power transmitting device 10.

[0071] The power transmitting device 210 also includes a plurality of power transmitting coils Ls, which are arranged along the travel route RO, allowing for contactless power supply to a plurality of automatic guided vehicles VE at the same time.

[0072] The manufacturing process of the power transmitting device 210 also includes a fourth step S14, a fifth step S15, a sixth step S16, and a seventh step S17. In the fifth step S15, it is determined whether the length of the cable 25 from the power supply circuit 11 to the power transmitting coil Ls is shorter than a predetermined reference wiring length. If it is determined that the length is shorter than the reference wiring length, it is determined in the sixth step S16 that multiple first power transmitting capacitors Cs1 are to be disposed. By adding the first power transmitting capacitors Cs1, the insufficient impedance of the power transmitting resonant circuit 13 can be compensated for, and the power transmitting resonant circuit 13 can be set to a resonant state at the operating frequency. By adjusting the number of first power transmitting capacitors Cs1 and adjusting the circuit constant of the power transmitting resonant circuit 13, the manufacturing efficiency of the power transmitting device 210 can be improved.

[0073] C. Third Embodiment: As shown in FIG. 13 , a contactless power transfer system 301 of this embodiment differs from the first embodiment in that it includes two types of power receiving devices 80. The same components as those in the above embodiments are denoted by the same reference numerals, and detailed descriptions thereof will be omitted as appropriate. The two types of power receiving devices 80 differ from each other in the position of the power receiving coil Lr relative to the travel route RO. To distinguish between the two types of power receiving devices 80, one power receiving device 80 will be referred to as a first power receiving device 80A, and the other power receiving device 80 will be referred to as a second power receiving device 80B.

[0074] The contactless power supply system 301 is provided with two types of power transmission devices 310 corresponding to the two types of power reception devices 80. To distinguish between the two types of power transmission devices 310, one power transmission device 310 is referred to as a first power transmission device 310A, and the other power transmission device 310 is referred to as a second power transmission device 310B. The first power transmission device 310A and the second power transmission device 310B have different positions of the power transmission coil Ls relative to the movement route RO.

[0075] The first power transmission device 310A and the second power transmission device 310B share a common housing 30. However, the position of the power transmission coil Ls of the first power transmission device 310A on the bottom surface 31 of the housing is different from the position of the power transmission coil Ls of the second power transmission device 310B on the bottom surface 31 of the housing. This makes it possible to provide power transmission devices 10 compatible with two types of power receiving devices 80. The power transmission device 310 can be manufactured using the manufacturing method of the first embodiment described above. According to this manufacturing method, two types of power transmission devices 310 having different positions of the power transmission coil Ls relative to the movement path RO can be efficiently manufactured using a common housing 30.

[0076] The third embodiment described above provides the same effects as the previous embodiments. Furthermore, the position of the power transmission coil Ls of the first power transmission device 310A on the housing bottom surface 31 is different from the position of the power transmission coil Ls of the second power transmission device 310B on the housing bottom surface 31. Therefore, it is possible to provide a power transmission device 10 compatible with two types of power receiving devices 80 while using a common housing 30.

[0077] D. Other Embodiments of the Power Transmitter Resonant Circuit: (D1) In the first embodiment, the power transmitter resonant capacitor Cs includes a first power transmitter capacitor Cs1 and a second power transmitter capacitor Cs2. The capacitance value of the power transmitter resonant capacitor Cs is changed by switching the state of the first switch SW1 between a conductive state and a non-conductive state. The manner in which the capacitance value of the power transmitter resonant capacitor Cs is changed is not limited to the first embodiment. As shown by "D1" in FIG. 15 , the power transmitter resonant capacitor Cs40 of the power transmitter resonant circuit 413 in this embodiment is a variable capacitance capacitor. The capacitance value of the power transmitter resonant capacitor Cs40 is switched between a first capacitance value and a second capacitance value by a switching signal Sig2 input from the control circuit 16. In this embodiment, too, the capacitance value of the power transmitter resonant capacitor Cs40 is changed, thereby switching the state of the power transmitter resonant circuit 413 between a resonant state and a non-resonant state.

[0078] (D2) In the power transmitter resonant circuit 13 of the first embodiment, a series resonant circuit is formed by the power transmitter resonant capacitor Cs and the power transmitter coil Ls. As shown by "D2" in FIG. 15 , the power transmitter resonant circuit 513 may be a parallel resonant circuit including the power transmitter coil Ls and the power transmitter resonant capacitor Cs50 connected in parallel to the power transmitter coil Ls. The power transmitter resonant capacitor Cs50 includes a first power transmitter capacitor Cs51 and a second power transmitter capacitor Cs52. A third switch SW3 is connected in series to the second power transmitter capacitor Cs52. When the third switch SW3 is set to a conductive state, the power transmitter resonant circuit 513 is set to a resonant state. When the third switch SW3 is set to a non-conductive state, the power transmitter resonant circuit 513 is set to a non-resonant state. In this embodiment as well, the capacitance value of the power transmitter resonant capacitor Cs50 is changed, thereby switching the power transmitter resonant circuit 513 between a resonant state and a non-resonant state.

[0079] (D3) In the second embodiment, the power transmitting device 210 includes two power transmitting resonant circuits 13: a first power transmitting resonant circuit 13A and a second power transmitting resonant circuit 13B. The first power transmitting resonant circuit 13A and the second power transmitting resonant circuit 13B are set to a power supplying state simultaneously. In another embodiment, the first power transmitting resonant circuit 13A and the second power transmitting resonant circuit 13B may be sequentially switched from a standby state to a power supplying state. Specifically, the power transmitting device 210 is disposed on a movement route RO other than the working area AE2 shown in FIG. 2. The first power transmitting resonant circuit 13A and the second power transmitting resonant circuit 13B are sequentially switched from a standby state to a power supplying state in accordance with the passage of the target automated guided vehicle VE. This allows the automated guided vehicle VE to be contactlessly supplied with power while it is traveling, rather than while it is stopped. The power transmitting device 210 may include three or more power transmitting coils Ls. 13 , the power transmission device 10 may be placed at a corner 320 or an intersection 321 on the travel route RO where the automated guided vehicle VE changes its traveling direction. At the corner, by utilizing the period when the automated guided vehicle VE changes its traveling direction, it is possible to supply power wirelessly for a longer period of time than when the automated guided vehicle VE travels straight.

[0080] E. Other Embodiments: (E1) In the first embodiment, no component is disposed below the inclined upper surface portion 32b. In another embodiment, a component may be disposed below the inclined upper surface portion 32b. Furthermore, although the housing 30 in the first embodiment has the inclined upper surface portion 32b, it may not have the inclined upper surface portion 32b. In this case, it is preferable to provide a slope adjacent to the housing 30. Furthermore, although the housing 30 in the first embodiment has the lower housing surface 31, it may not have the upper housing surface 32. Furthermore, although the unit region LR is square in the first embodiment, the shape of the unit region LR may be rectangular or another polygonal shape.

[0081] (E2) In the first embodiment, the power transmission device 10 includes the power supply circuit 11 and the power transmission circuit 12 arranged in the internal space 33 of the housing 30. In another embodiment, the power supply circuit 11 may be arranged outside the housing 30, or both the power supply circuit 11 and the power transmission circuit 12 may be arranged outside the housing 30. In the first embodiment, the power transmission circuit 12 includes the power transmission resonant capacitor Cs, the first switch SW1, the control circuit 16, and the communication unit 17. In another embodiment, the power transmission circuit 12 may include other circuits. Specifically, the power transmission circuit 12 may include a filter or a protection circuit. The protection circuit is, for example, a circuit for blocking current to the power receiving coil Lr when an overcurrent flows through the power receiving coil Lr. Furthermore, the power transmission circuit 12 sets the power transmission resonant circuit 13 to a non-resonant state using the first switch SW1, thereby setting the power transmission coil Ls to a standby state. In another embodiment, the inverter 15 of the power supply circuit 11 may be controlled to limit the current to the power transmitting resonant circuit 13 and set the power transmitting coil Ls to a standby state.

[0082] (E3) In the first embodiment, the mobile body on which the power receiving device 80 is mounted is an automated guided vehicle VE. The mobile body on which the power receiving device 80 is mounted is not limited to an automated guided vehicle VE, and may be a traveling robot or the like. Furthermore, in the first embodiment, the power transmitting device 10 is disposed on a floor RS inside a warehouse. In another embodiment, the power transmitting device 10 may be disposed outdoors on a road surface on which the automated guided vehicle VE travels. Specifically, the power transmitting device 10 may be disposed on a paved road. Regardless of whether the power transmitting device 10 is disposed indoors or outdoors, according to the present disclosure, the position of the power transmitting coil Ls can be freely aligned with the position of the power receiving coil Lr.

[0083] (E4) In the first embodiment, the automated guided vehicle VE travels by detecting a visible position marker MK with the marker sensor 95. As another mode in which the automated guided vehicle VE travels along the travel route RO, the automated guided vehicle VE may travel by detecting a magnetically or optically detectable tape, such as a magnetic tape, arranged on the travel route RO with the marker sensor 95. Alternatively, the automated guided vehicle VE may travel by detecting an RFID (radio frequency identification) arranged on the travel route RO with the marker sensor 95. Alternatively, the automated guided vehicle VE may travel without arranging a position marker MK on the travel route RO, by detecting the distance to surrounding objects using a ranging device or image recognition such as LiDAR (Light Detection and Ranging) mounted on the automated guided vehicle VE, and estimating the current position.

[0084] (E5) In the first embodiment, the power transmitter resonant circuit 13 has a so-called S-S circuit configuration in which a power transmitter resonant capacitor Cs is connected in series to the power transmitter coil Ls, and the power receiver resonant circuit has a so-called S-S circuit configuration in which a power receiver capacitor Cr is connected in series to the power receiver coil Lr. The circuit configurations of the power transmitter resonant circuit 13 and the power receiver resonant circuit 83 are not limited to the S-S circuit configuration. (a) For example, the power transmitter resonant circuit 13 may have a so-called P-S circuit configuration in which a power transmitter resonant capacitor Cs is connected in parallel to the power transmitter coil Ls, and the power receiver resonant circuit 83 may have a so-called P-S circuit configuration in which a power receiver capacitor Cr is connected in series to the power receiver coil Lr. (b) Furthermore, the power receiver resonant circuit 83 may have a so-called P-SS circuit configuration in which, in addition to the power transmitter resonant capacitor Cs connected in series to the power transmitter coil Ls, a capacitor is connected in parallel to the power transmitter coil Ls, and two power receiver capacitors are connected in series to each of the terminals of the power receiver coil Lr. (c) The power transmitter resonant circuit 13 may also include a closed circuit in which a coil and a capacitor are connected in series. The coil of this closed circuit is arranged in a position where it can be magnetically coupled to the power receiving coil Lr when the power transmitter coil Ls is magnetically coupled to the power receiving coil Lr. (d) The capacitor of the closed circuit may also be connected in parallel to the coil rather than in series. (e) The power transmitter resonant circuit 13 may also include a coil connected in series to the power transmitter coil Ls and a capacitor connected in parallel to the coil. This coil is arranged in a position where it can be magnetically coupled to the power receiving coil Lr when the power transmitter coil and the power receiving coil are magnetically coupled.

[0085] The present disclosure is not limited to the above-described embodiments and modifications, and can be realized in various configurations without departing from the spirit thereof. For example, the technical features in the embodiments and modifications corresponding to the technical features in each aspect described in the Summary of the Invention section can be appropriately replaced or combined to solve some or all of the above-described problems or achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be appropriately deleted.

[0086] F. Other Aspects: Features of the present disclosure are as follows: (Aspect 1) A power transmitting device (10, 210, 310) that wirelessly supplies power to a moving object (VE) having a power receiving coil (Lr), the power transmitting device comprising: a housing (30) placed on a floor surface (RS); and at least one power transmitting coil (Ls) housed in the housing, the housing having: a housing top surface (32) that supports the moving object; and an internal space (33) formed below the housing top surface, the at least one power transmitting coil (Ls) being disposed within the internal space, and the entire area of ​​the housing top surface being larger than the size of the at least one power transmitting coil when viewed from above. (Mode 2) The power transmitting device according to Mode 1, further comprising: an electric circuit (11, 12) for supplying power to the at least one power transmitting coil; and a plurality of support members (38) arranged below the upper surface of the housing for supporting the upper surface of the housing, the plurality of support members being arranged in an area of ​​the entire area of ​​the upper surface of the housing excluding an area on the upper surface of the housing occupied by the at least one power transmitting coil and an area on the upper surface of the housing occupied by the electric circuit. (Mode 3) The power transmitting device according to Mode 1 or 2, wherein the electric circuit includes a power supply circuit (11) for supplying AC power at an operating frequency to the at least one power transmitting coil. (Mode 4) The power transmitting device according to Mode 2 or 3, wherein the electric circuit includes a resonant capacitor (Cs) electrically connected to the at least one power transmitting coil. (Form 5) The power transmission device according to Form 4, wherein the resonant capacitor has a capacitance value that is changeable between a first capacitance value and a second capacitance value that is larger than the first capacitance value, and the electric circuit further includes a control circuit (16) for switching the capacitance value between the first capacitance value and the second capacitance value to switch the state of the power transmission coil between a power supply state in which power is supplied to the power receiving coil in a contactless manner and a standby state in which power supply to the power receiving coil in a contactless manner is stopped.(Mode 6) The power transmitting device according to any one of Modes 2 to 5, wherein the housing further has a housing bottom surface (31) arranged along the floor surface, the size of the at least one power transmitting coil in a top view is set to be a size in units of unit areas (LR) obtained by dividing the entire area of ​​the housing bottom surface into a plurality of parts, and each support member of the plurality of support members is arranged in the unit area. (Mode 7) The power transmitting device according to Mode 6, wherein the electric circuit includes a power supply circuit (11) that supplies AC power at an operating frequency to the at least one power transmitting coil, and the size of the power supply circuit in a top view is set to be a size in units of the unit area. (Mode 8) The power transmitting device according to Mode 6 or 7, wherein the electric circuit includes a resonant capacitor (Cs) electrically connected to the at least one power transmitting coil, and the size of the resonant capacitor in a top view is set to be a size in units of the unit area. (Mode 9) The power transmitting device according to any one of Modes 1 to 8, wherein the at least one power transmitting coil is arranged along a predetermined movement path (RO) of the moving body. (Mode 10) The power transmitting device according to any one of Modes 1 to 9, wherein the at least one power transmitting coil includes a plurality of power transmitting coils, and the plurality of power transmitting coils are arranged along the movement path. (Mode 11) The power transmitting device according to Mode 9 or 10, further comprising: an electric circuit (11, 12) for supplying power to the at least one power transmitting coil; and a plurality of support members (38) arranged below the upper surface of the housing for supporting the upper surface of the housing, wherein the moving body has a plurality of wheels (90), and the plurality of support members are arranged at positions overlapping, in the top view, with a track (LT) along which the plurality of wheels travel when the moving body travels along the movement path, and the at least one power transmitting coil and the electric circuit are arranged at positions excluding the track in the top view.(Mode 12) A manufacturing method of a power transmitting device (10, 210) that wirelessly supplies power to a moving body (VE) having a power receiving coil (Lr), comprising: (a) a housing (30) having a housing bottom surface (31), a housing top surface (32) disposed above the housing bottom surface, and an internal space (33) defined by the housing bottom surface and the housing top surface; and (b) a plurality of support members (38) disposed between the housing bottom surface and the housing top surface for supporting the housing top surface, the plurality of support members filling the internal space; and a second step (S2) of marking, on the housing before adjustment, a facing position (131) on the housing bottom surface that faces the power receiving coil when the moving body travels along a predetermined travel path (RO). and a third step (S3) of removing from the internal space some of the plurality of support members that are arranged at the opposing positions, and arranging a power transmission coil (Ls) below the opposing positions. (Mode 13) A manufacturing method according to Mode 12, wherein the power transmitting device further comprises an electric circuit (11, 12, 25) having a resonant capacitor (Cs) electrically connected to the power transmitting coil, a power supply circuit (11) that supplies AC power at an operating frequency to the power transmitting coil, and wiring (25) for supplying power from the power supply circuit to the power transmitting coil, and the manufacturing method includes, after the third step, a fourth step (S14) of determining a placement position of the power supply circuit on the underside of the housing, a fifth step (S15) of determining whether or not the length of the wiring from the power supply circuit to the power transmitting coil is shorter than a predetermined reference wiring length, and a sixth step (S16) of determining to place a plurality of reference capacitors (Cs1) having a predetermined reference capacitance as the resonant capacitor when it is determined in the fifth step that the length is shorter than the reference wiring length. The manufacturing method further comprises a seventh step (S17) of removing from the internal space some of the plurality of support members, which are some of the support members in a planned area where the electrical circuit is to be placed, and placing the electrical circuit in the planned area.(Mode 14) A contactless power feeding system (301) for contactlessly feeding power to a moving body (VE) having a power receiving coil (Lr), comprising: a first power transmission device (310A) and a second power transmission device (310B) different from the first power transmission device, wherein each of the first power transmission device and the second power transmission device comprises: a housing (30) arranged on a floor surface (RS); and at least one power transmission coil (Ls) housed in the housing, wherein the housing has: a housing bottom surface (31) arranged along the floor surface; and a housing top surface (32) arranged above the housing bottom surface, the housing top surface supporting the moving body; and an internal space (33) defined by the housing bottom surface and the housing top surface, wherein the at least one power transmission coil is arranged in the internal space, and the size of the housing of the first power transmission device is the same as the size of the housing of the second power transmission device, a contactless power supply system in which the position of the at least one power transmission coil of the first power transmission device on the underside of the housing is different from the position of the at least one power transmission coil of the second power transmission device on the underside of the housing.

Claims

1. A power transmission device (10, 210, 310) for non-contact power supply to a moving body (VE) having a power receiving coil (Lr), comprising: a housing (30) disposed on a traveling road surface (RS); and at least one power transmission coil (Ls) housed in the housing, wherein the housing has a housing upper surface (32) for supporting the moving body and an internal space (33) formed below the housing upper surface, the at least one power transmission coil (Ls) is disposed in the internal space, and the entire area of the housing upper surface is larger than the size of the at least one power transmission coil as viewed from above. A power transmission device.

2. The power transmission device according to claim 1, further comprising: an electric circuit (11, 12) for supplying power to the at least one power transmission coil; and a plurality of support members (38) disposed below the housing upper surface for supporting the housing upper surface, wherein the plurality of support members are disposed in an area excluding the occupied area of the at least one power transmission coil on the housing upper surface and the occupied area of the electric circuit on the housing upper surface in the entire area of the housing upper surface. A power transmission device.

3. The power transmission device according to claim 2, wherein the electric circuit includes a power supply circuit (11) for supplying AC power of an operating frequency to the at least one power transmission coil. A power transmission device.

4. The power transmission device according to claim 2, wherein the electric circuit includes a resonance capacitor (Cs) electrically connected to the at least one power transmission coil. A power transmission device.

5. The power transmission device according to claim 4, wherein the resonance capacitor is capable of changing between a first capacitance value and a second capacitance value larger than the first capacitance value, and the electric circuit further includes a control circuit (16) for switching the capacitance value between the first capacitance value and the second capacitance value to switch the state of the power transmission coil between a power supply state for non-contact power supply to the power receiving coil and a standby state for stopping non-contact power supply to the power receiving coil. A power transmission device.

6. The power transmission device according to claim 2, wherein the housing further has a housing bottom surface (31) arranged along the traveling road surface, the size of the at least one power transmission coil in top view is set to be a size in units of unit areas (LR) obtained by dividing the entire area of the housing bottom surface into a plurality of parts, and each of the plurality of support members is arranged in the unit area. Power transmission device.

7. The power transmission device according to claim 6, wherein the electric circuit includes a power supply circuit (11) that supplies AC power with an operating frequency to the at least one power transmission coil, and the size of the power supply circuit in top view is set to be a size in units of the unit area. Power transmission device.

8. The power transmission device according to claim 6, wherein the electric circuit includes a resonance capacitor (Cs) electrically connected to the at least one power transmission coil, and the size of the resonance capacitor in top view is set to be a size in units of the unit area. Power transmission device.

9. The power transmission device according to claim 1, wherein the at least one power transmission coil is arranged along a predetermined movement path (RO) of the moving body. Power transmission device.

10. The power transmission device according to claim 9, wherein the at least one power transmission coil includes a plurality of power transmission coils. Power transmission device.

11. The power transmission device according to claim 9, further comprising an electric circuit (11, 12) for supplying power to the at least one power transmission coil, and a plurality of support members (38) arranged under the housing upper surface for supporting the housing upper surface, the moving body includes a plurality of wheels (90), the plurality of support members are arranged at positions overlapping with a track (LT) through which the plurality of wheels pass in top view when the moving body travels along the movement path, and the at least one power transmission coil and the electric circuit are arranged at positions excluding the track in top view. Power transmission device.

12. A method for manufacturing a power transmission device (10, 210) that non - contact power - feeds a moving body (VE) having a power receiving coil (Lr), comprising: (a) a housing (30) having a housing bottom surface (31), a housing top surface (32) disposed above the housing bottom surface, and an internal space (33) defined by the housing bottom surface and the housing top surface; (b) a first step (S1) of preparing a pre - adjustment housing (130) including a plurality of support members (38) disposed between the housing bottom surface and the housing top surface for supporting the housing top surface, the plurality of support members being filled in the internal space; a second step (S2) of marking an opposing position (131) on the housing bottom surface facing the power receiving coil when the moving body travels along a predetermined travel route (RO) on the pre - adjustment housing; and a third step (S3) of removing a part of the support members disposed at the opposing position from the internal space and disposing a power transmission coil (Ls) below the opposing position.

13. The manufacturing method according to claim 12, wherein the power transmission device further includes an electric circuit (11, 12, 25) having a resonance capacitor (Cs) electrically connected to the power transmission coil, a power supply circuit (11) for supplying AC power of an operating frequency to the power transmission coil, and a wiring (25) for supplying power from the power supply circuit to the power transmission coil. The manufacturing method further includes: a fourth step (S14) of determining an arrangement position of the power supply circuit on the housing bottom surface after the third step; a fifth step (S15) of determining whether the length of the wiring from the power supply circuit to the power transmission coil is shorter than a predetermined reference wiring length; a sixth step (S16) of determining, in the fifth step, when it is determined that the length is shorter than the reference wiring length, to arrange a plurality of reference capacitors (Cs1) having a predetermined reference capacitance as the resonance capacitor; and a seventh step (S17) of removing a part of the support members among the plurality of support members, which is a part of the support members in a planned area where the electric circuit is to be arranged, from the internal space and arranging the electric circuit in the planned area.

14. A non-contact power supply system (301) for non-contact power supply to a moving body (VE) having a power receiving coil (Lr), comprising a first power transmission device (310A) and a second power transmission device (310B) different from the first power transmission device, wherein each of the first power transmission device and the second power transmission device includes a housing (30) disposed on a traveling road surface (RS) and at least one power transmission coil (Ls) housed in the housing. The housing has a housing bottom surface (31) disposed along the traveling road surface, a housing top surface (32) disposed above the housing bottom surface and supporting the moving body, and an internal space (33) defined by the housing bottom surface, the housing top surface, and the at least one power transmission coil is disposed in the internal space. The size of the housing of the first power transmission device is the same as the size of the housing of the second power transmission device, and the position of the at least one power transmission coil of the first power transmission device on the housing bottom surface is different from the position of the at least one power transmission coil of the second power transmission device on the housing bottom surface.

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