Contactless power receiving device

Abstract

To provide a contactless power receiver that suppresses thermal stress acting on a power receiving unit through a shield.SOLUTION: A contactless power receiver 10 includes a power receiving unit 20 including a power receiving coil disposed on the bottom 14 of a vehicle and facing a power transmitting coil of a power transmitting device so as to receive power in a non-contact manner, a lower case 30 that is attached to the bottom of the vehicle, accommodates and supports the vehicle lower side of the power receiving unit, and has a portion that supports at least a power receiving coil portion in which the power receiving coil is arranged in the power receiving unit is formed of resin, and a shield 60 supported by the lower case and arranged to surround the lower case when viewed from the bottom, and made of non-magnetic metal.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a contactless power receiving device. [Background technology]

[0002] In recent years, the development of contactless power supply devices that charge vehicles without contact has progressed. By positioning a power receiving device installed on a vehicle body above a power transmitting device installed on the road surface, power is transmitted from the power transmitting device to the power receiving device without contact, and power is supplied to the vehicle.

[0003] In this case, the coils of the power transmitting device and the power receiving device are heated by the power supply from the power transmitting device to the power receiving device. As a countermeasure against this heating, a configuration has been proposed in which a radiator fan or the like provided in the vehicle is driven to cool the power transmitting device and the power receiving device when power is supplied (see Patent Document 1).

[0004] On the other hand, the power receiving device is provided with a power receiving unit in which a power receiving coil, etc. is arranged, and a shield made of a non-magnetic metal is arranged around the power receiving unit when viewed from the bottom of the vehicle, in order to prevent or suppress a decrease in power supply efficiency caused by the high-frequency magnetic field from the power transmitting device acting on the steel material that constitutes the vehicle body near the power receiving unit, and heat generation of the steel material that constitutes the vehicle body, etc. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2016-152709 A Summary of the Invention [Problem to be solved by the invention]

[0006] The shield is made of aluminum alloy, which is a non-magnetic metal material, because of its workability and cost. On the other hand, an exhaust pipe is installed on the bottom of the vehicle, and due to space restrictions, the exhaust pipe is sometimes installed near the shield.

[0007] The exhaust pipe becomes very hot while driving or immediately after stopping, and can sometimes exceed 500°C. Therefore, if the exhaust pipe is routed near the shield, heat is transferred to the power receiving unit through the shield, which is made of aluminum alloy, which has a relatively high thermal conductivity compared to resin, etc., and the thermal stress of the power receiving unit increases.

[0008] There is room for improvement in this regard with contactless power receiving devices.

[0009] The present disclosure has been made in consideration of the above-mentioned circumstances, and has an object to provide a non-contact power receiving device that suppresses thermal stress acting on a power receiving unit via a shield. [Means for solving the problem]

[0010] The non-contact type power receiving device of the first aspect comprises a power receiving unit that is arranged at the bottom of the vehicle and includes a power receiving coil that is arranged opposite a power transmitting coil of a power transmitting device to enable power receiving without contact; a lower case that is attached to the bottom of the vehicle, houses and supports the lower side of the power receiving unit, and the portion that supports at least the power receiving coil portion in which the power receiving coil is arranged in the power receiving unit is formed from resin; and a shield that is supported by the lower case, is arranged to surround the lower case in a bottom view, and is formed from a non-magnetic metal.

[0011] In the first mode, a vehicle is parked in a parking lot or the like, and a power receiving device provided at the bottom of the vehicle is placed on a power transmitting device installed in the parking lot. By passing a high-frequency current through a power transmitting coil of the power transmitting device, a high-frequency magnetic field is applied to a power receiving coil of the power receiving device (power receiving unit), and power can be supplied from the power transmitting device to the power receiving device in a contactless manner.

[0012] In addition, since the lower case that houses the vehicle lower side of the power receiving unit is made of resin, it does not impede the high frequency magnetic field from acting on the power receiving coil.

[0013] In addition, a shield made of a non-magnetic metal is provided to surround the lower case in which the power receiving unit is housed when viewed from the bottom, thereby preventing or suppressing the high-frequency magnetic field generated from the power transmission coil of the power transmission device from acting on the vehicle body located on the shield and heating the vehicle body.

[0014] Furthermore, an exhaust pipe extending from the front side to the rear side of the vehicle on the underside of the vehicle is routed near the shield, and there is a risk that heat from the exhaust pipe will be conducted to the power receiving unit via the shield. In particular, when the shield is made of an aluminum alloy, which is a non-magnetic metal, from the viewpoint of workability, etc., there is a risk that the thermal stress of the power receiving unit will increase due to heat conduction from the shield, which has a relatively high thermal conductivity compared to resin.

[0015] However, in this aspect, the portion of the lower case that houses the vehicle lower side of the power receiving unit and that supports the power receiving coil of the power receiving unit is made of resin, and therefore the thermal conductivity of that portion of the lower case is relatively low compared to non-magnetic metals such as aluminum alloys, etc. Therefore, heat conduction from the shield through the lower case to the power receiving unit is suppressed, and an increase in thermal stress on the power receiving unit can be suppressed.

[0016] A non-contact type power receiving device according to a second aspect is the non-contact type power receiving device according to the first aspect, in which the resin is non-conductive.

[0017] According to the second aspect, in the lower case, at least the portion of the power receiving unit that supports the power receiving coil portion is made of a non-conductive resin.

[0018] Therefore, when the vehicle is stopped and the power receiving device provided at the bottom of the vehicle is positioned on the power transmitting device, a high-frequency current is passed through the power transmitting coil of the power transmitting device, causing current to flow through the power receiving coil of the power receiving device (power receiving unit), and power can be supplied from the power transmitting device to the power receiving device non-contact.

[0019] At this time, the high frequency magnetic field acts on the portion of the lower case that supports the power receiving coil. However, since the portion that supports the power receiving coil is made of non-conductive resin, no current flows, and high power supply efficiency can be maintained.

[0020] A non-contact power receiving device according to a third aspect is a non-contact power receiving device according to the first or second aspect, wherein the lower case has a portion supporting parts of the power receiving unit other than the power receiving coil portion, the portion being formed from a non-magnetic metal.

[0021] According to the third aspect, a portion of the lower case that houses the lower half of the power receiving unit and that supports the portion of the power receiving unit other than the power receiving coil is made of a non-magnetic metal, which prevents or suppresses the high-frequency magnetic field from the power transmitting coil from acting on the portion of the power receiving unit other than the power receiving coil, such as a rectifier, generating noise.

[0022] A non-contact power receiving device according to a fourth aspect is the non-contact power receiving device according to the first or second aspect, in which the power receiving unit consists only of the power receiving coil section, and the lower case is entirely made of resin.

[0023] According to the fourth aspect, the power receiving unit is composed only of a power receiving coil section in which a power receiving coil is disposed, and the entire lower case supporting the power receiving coil section is made of resin. Therefore, since the entire lower case housing the vehicle lower side of the power receiving unit is made of resin, the high frequency magnetic field is not impeded from acting on the power receiving coil (non-contact power supply).

[0024] The non-contact power receiving device of the fifth aspect is a non-contact power receiving device of any one of the first to fourth aspects, further comprising an upper case which is attached to the bottom of the vehicle, accommodates the upper side of the power receiving unit, and is integrated with the lower case to store the power receiving unit, and is made of a non-magnetic metal.

[0025] According to the fifth aspect, the upper unit houses the upper side of the power receiving unit, and the upper unit and the lower unit are integrated to store the power receiving unit inside the case. Here, a high-frequency magnetic field acts on the power receiving device when power is supplied, and there is a risk that a part of the magnetic field acts on the steel material of the vehicle body located above the power receiving unit, causing the steel material of the vehicle body to heat up. However, according to this aspect, the upper unit that houses the upper side of the power receiving unit is made of a non-magnetic metal, so that the high-frequency magnetic field is prevented or suppressed from acting on the steel material of the vehicle body above the power receiving unit, and heating of the steel material of the vehicle body is prevented or suppressed.

[0026] A non-contact type power receiving device according to a sixth aspect is the non-contact type power receiving device according to any one of the first to fifth aspects, wherein the shield is supported only by the lower case attached to the bottom of a vehicle body.

[0027] According to the sixth aspect, since the shield is supported only by the lower case attached to the bottom of the vehicle body, heat from the exhaust pipe is conducted from the shield to the power receiving unit only through the lower case. Therefore, even if the shield is made of an aluminum alloy or the like having a relatively high thermal conductivity compared to resin, the lower case is made of a resin having a relatively low thermal conductivity compared to metal, so that the thermal conduction from the lower case to the power receiving unit is suppressed. In other words, an increase in thermal stress of the power receiving unit is suppressed.

[0028] In addition, the lower case "attached to the bottom of the vehicle" includes a lower case attached to the bottom of the vehicle via other members excluding the shield.

[0029] A non-contact power receiving device according to a seventh aspect is the non-contact power receiving device according to any one of the first to sixth aspects, wherein the non-magnetic metal is an aluminum alloy.

[0030] According to the seventh aspect, since the non-magnetic metal is an aluminum alloy, it has excellent workability, and therefore by forming the shield and the upper case from an aluminum alloy, they can be easily processed.

[0031] A non-contact type power receiving device according to an eighth aspect is the non-contact type power receiving device according to any one of the first to seventh aspects, wherein the resin is glass fiber reinforced plastic.

[0032] According to the eighth aspect, the resin used for the lower case is glass fiber reinforced plastic, and therefore has strength, thereby preventing or suppressing damage to the power receiving device arranged on the bottom of the vehicle caused by pebbles or the like hitting the power receiving device from the road surface while the vehicle is traveling. Effect of the Invention

[0033] The present disclosure can suppress thermal stress acting on the power receiving unit through the shield. [Brief description of the drawings]

[0034] [Figure 1] 1 is a side view of a vehicle in which a non-contact power receiving device according to an embodiment is provided. [Diagram 2] 1 is a schematic bottom view of a vehicle in which a non-contact power receiving device according to an embodiment is provided; [Diagram 3] 3 is a cross-sectional view taken along line 3-3 in FIG. 2. [Figure 4] 2 is an exploded perspective view showing the power receiving unit, the lower case, and the upper case. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] Hereinafter, a non-contact type power receiving device mounted on a vehicle according to an embodiment will be described with reference to Figures 1 to 4. In each figure, the arrow FR indicates the front of the vehicle, the arrow UP indicates the upper side of the vehicle, and the arrow LH indicates the left side of the vehicle.

[0036] 1 and 2, a non-contact type power receiving device 10 (hereinafter referred to as "power receiving device 10") according to this embodiment is disposed on a bottom 14 of a vehicle 12. Therefore, the vehicle 12 can be parked in a parking lot or the like, and the power receiving device 10 can be placed above a power transmitting device 16 disposed on the road side of the parking lot. In this state, a high-frequency current is passed through a power transmitting coil of the power transmitting device 16, and a high-frequency magnetic field is generated, causing a current to flow through the power receiving coil of the power receiving device 10, so that power can be supplied from the power transmitting device 16 to the power receiving device 10 in a non-contact manner.

[0037] As shown in FIG. 3, the power receiving device 10 includes a power receiving unit 20, a lower case 30, an upper case 40, and a shield 60.

[0038] As shown in FIG. 4, the power receiving unit 20 is formed in a substantially rectangular shape and is divided into a power receiving coil section 22 in which a plurality of power receiving coils are arranged, and a rectification section 24 in which a plurality of rectifiers are arranged.

[0039] As shown in FIGS. 3 and 4, the power receiving unit 20 is configured to be housed in a lower case 30 and an upper case 40. As shown in FIG.

[0040] As shown in FIG. 4, the lower case 30 has a recess 32 in which the lower half of the power receiving unit 20 is accommodated, and a flange portion 34 that extends outward from the upper end of the recess 32 and is formed around the recess 32.

[0041] A plurality of fastening portions 36 protruding upward are provided on the inside of the upper end of the vertical wall portion of the recess 32. The fastening portions 36 are each formed with a screw hole 36A for fastening to the upper case 40.

[0042] Furthermore, the flange portion 34 is formed with a plurality of screw holes 34A for fastening to the shield 60.

[0043] In addition, the portion of the lower case 30 that supports the power receiving coil portion 22 of the power receiving unit 20 (the recess 32 and the flange portion 34) is referred to as the first portion 30A, and the portion that supports the rectification portion 24 (the recess 32 and the flange portion 34) is referred to as the second portion 30B.

[0044] The first part 30A is made of a non-conductive resin material, for example, GFRP (Glass Fiber Reinforced Plastics), so that a high-frequency magnetic field from the power transmitting device 16 acts on the power receiving coil part 22 of the power receiving unit 20. Note that a screw hole 34A is formed only in the flange part 34 of the first part 30A.

[0045] On the other hand, since the second part 30B is formed from a non-magnetic metal material that blocks magnetic fields, such as an aluminum alloy (JIS A5052 is one example), since the application of a high-frequency magnetic field from the power transmission device 16 may cause noise in the rectifier.

[0046] As shown in Fig. 3, the upper case 40 houses the upper half of the power receiving unit 20 and has a recess 42 that is open downward. A plurality of screw holes 42A (only two are shown in Fig. 4) are formed in a vertical wall of the recess 42. The fastening portion 36 of the lower case 30 is inserted into the recess 42 of the upper case 40, and a bolt (not shown) is screwed into the screw hole 36A of the fastening portion 36 and the screw hole 42A of the recess 42, and the lower case 30 and the upper case 40 are fastened together with a nut, thereby forming an integrated structure.

[0047] The entire upper case 40 is made of the same material, for example, an aluminum alloy (for example, JIS A5052).

[0048] Therefore, the lower half of the power receiving unit 20 is accommodated in the recess 32 of the lower case 30, and the upper half is accommodated in the recess 42 of the upper case 40, and the lower case 30 and the upper case 40 are fastened together via the fastening portion 36, so that the power receiving unit 20 is stored and fixed inside the case.

[0049] 3, the upper case 40 has a plurality of mounting portions 46 (not shown in FIG. 4) formed to extend outward from the upper end of the recess 42. The mounting portions 46 are fastened to brackets 52 provided on the bottom 14 of the vehicle 12, whereby the power receiving unit 20 is attached to the bottom 14 of the vehicle 12.

[0050] Hereinafter, the power receiving unit 20 housed in this case (the lower case 30 and the upper case 40) will be referred to as a housed power receiving unit 50.

[0051] As shown in Fig. 2, a flat shield 60 is disposed on the outside of the stored power receiving unit 50. As shown in Fig. 3, the shield 60 has a hole 62 formed in the center for storing the stored power receiving unit 50 (the recess 32 of the lower case 30).

[0052] 3, the flange portion 34 of the lower case 30 and the shield 60 are overlapped by inserting the recessed portion 32 of the lower case 30 into the hole portion 62 of the shield 60. The shield 60 is attached to the storage and power receiving unit 50 (lower case 30) by screwing a bolt 64 into a screw hole 34A of the flange portion 34 and a screw hole of the shield 60 (not shown) and fastening with a nut 66. In other words, the shield 60 is attached to the bottom 14 of the vehicle 12 via the storage and power receiving unit 50. The fastening portion of the lower case 30 and the shield 60 with the bolt 64 and the nut 66 is referred to as a fastening portion 68.

[0053] The shield 60 is made of a non-magnetic metal, for example, an aluminum alloy (JIS A5052 as one example) from the standpoint of workability and cost.

[0054] As a result, as shown in FIG. 2, the shield 60 is disposed so as to surround the storage and power receiving unit 50.

[0055] As shown in FIG. 2, an exhaust pipe 70 is arranged on the bottom 14 of the vehicle 12 from the front side of the vehicle toward the rear end of the vehicle, but is arranged in a manner that wraps around to the right side of the vehicle so as to avoid the stored power receiving unit 50.

[0056] At this time, as shown in FIGS. 2 and 3, a portion of the exhaust pipe 70 is disposed between the shield 60 and the bottom portion 14 of the vehicle 12.

[0057] (action)

[0058] The vehicle 12 equipped with the power receiving device 10 configured in this manner is stopped in a parking lot or the like, and the power receiving device 10 (power receiving unit 20) is positioned above the power transmitting device 16 provided on the road surface or the like of the parking lot.

[0059] In this state, when a high-frequency current is applied to the power transmitting coil of the power transmitting device 16, a current flows in the power receiving coil of the power receiving unit 20 due to the action of the high-frequency magnetic field.

[0060] At this time, since the first part 30A of the lower case 30 disposed below the power receiving unit 20 (on the power transmitting device 16 side) is made of a non-conductive resin, for example, GFRP, the action of the high-frequency magnetic field from the power transmitting device 16 (power transmitting coil) on the power receiving coil part 22 of the power receiving unit 20 is not impeded. In other words, there is no impediment to the power supply from the power transmitting device 16 to the power receiving device 10 (power receiving unit 20).

[0061] Furthermore, since the second part 30B of the lower case 30 is formed from a non-magnetic metal, such as an aluminum alloy, the magnetic field acting from the power transmission device 16 side is prevented or suppressed from acting on the rectifier section 24 of the power receiving unit 20, thereby preventing or suppressing malfunctions such as noise generation in the rectifier.

[0062] On the other hand, as shown in Figures 2 and 3, the shield 60 arranged around the storage power receiving unit 50 is formed from a non-magnetic metal, such as an aluminum alloy, so that the high-frequency magnetic field generated by the power transmission device 16 can be prevented or suppressed from acting on the steel of the body of the vehicle 12 located above the shield 60 and heating the steel of the body.

[0063] 2 and 3, the exhaust pipe 70 is disposed adjacent to the shield 60 at the bottom 14 of the vehicle 12 due to space limitations. In particular, a portion of the exhaust pipe 70 is disposed so as to overlap (vertically overlap) with the shield 60 in a bottom view.

[0064] Therefore, when the exhaust pipe 70 is at a high temperature while the vehicle 12 is running or stopped, heat is conducted from the exhaust pipe 70 to the lower case 30 via the shield 60 made of an aluminum alloy having a relatively high thermal conductivity compared to resin. Here, the first part 30A of the lower case 30 is made of GFRP having a relatively low thermal conductivity compared to metal, so that thermal stress acting on the power receiving unit 20 housed in the case is reduced. In other words, heat is conducted from the exhaust pipe 70 to the power receiving unit 20 via the lower case 30 made of GFRP having a thermal conductivity of about 1 / 100 compared to the shield 60 made of an aluminum alloy, so that thermal stress on the power receiving unit 20 is suppressed.

[0065] In particular, the lower case 30 is fastened to the shield 60 at the flange portion 34, separate from the fastening portion (fastening portion 36) with the upper case 40. In other words, the shield 60 is supported (fastened) only to the lower case 30. Therefore, the only heat conduction path from the shield 60 to the power receiving unit 20 is the path via the lower case 30 made of resin to the power receiving unit 20, suppressing heat conduction and further suppressing thermal stress on the power receiving unit 20.

[0066] In addition, the portion of the lower case 30 corresponding to the receiving coil section 22 of the power receiving unit 20 (first part 30A) is made of non-conductive resin. Therefore, when a high-frequency current is passed through the transmitting coil of the power transmitting device 16 to pass a current through the receiving coil of the power receiving unit 20, a current flowing through the first part 30A of the lower case 30 and a reduction in the power supply efficiency to the power receiving unit 20 is prevented or suppressed.

[0067] In particular, since the lower case 30 and the shield 60 are fastened via the fastening portion 68 provided only in the first part 30A of the lower case 30, heat is conducted from the shield 60 via the fastening portion 68 only to the first part 30A of the lower case 30 where the non-conductive resin (GFRP) is formed. Therefore, heat conduction from the lower case 30 to the power receiving unit 20 is suppressed, and an increase in thermal stress of the power receiving unit 20 is suppressed.

[0068] Furthermore, by forming the portion of the lower case 30 that supports the power receiving coil section 22 of the power receiving unit 20 (first portion 30A) from a non-conductive resin, such as GFRP, the lower case 30 can have sufficient strength, and deformation and damage can be prevented or suppressed even if a stone or the like hits it from the road surface.

[0069] On the other hand, in the lower case 30, the part supporting the rectifier section 24 of the power receiving unit 20 (second part 30B) is formed from a non-magnetic metal, such as an aluminum alloy, so that the high-frequency magnetic field from the power transmitting device 16 is shielded, and malfunctions in the rectifier, for example, the generation of noise, are prevented.

[0070] Furthermore, by forming the upper case 40 from a non-magnetic metal, such as an aluminum alloy, it is possible to prevent or suppress heating of the vehicle body (steel material) located above the upper case 40 due to the action of a high-frequency magnetic field when power is supplied.

[0071] (Supplementary explanation of the embodiment)

[0072] In this embodiment, the power receiving unit 20 has been described as having the power receiving coil section 22 and the rectifier section 24, but it may also be provided with only the power receiving coil section 22 (power receiving coil). In this case, the rectifier is provided in a location separate from the power receiving unit 20 (for example, in the battery pack or in the vehicle interior). In this way, when only the power receiving coil is provided in the power receiving unit 20, the entire lower case 30 is formed of a non-conductive resin.

[0073] In the present embodiment, GFRP has been described as an example of the material for the first portion 30A of the lower case 30, but the material is not limited to this. Furthermore, although a non-conductive resin is preferable, other resins may also be used.

[0074] In this embodiment, the second portion 30B of the lower case 30 is preferably made of a non-magnetic metal, but is not limited to this.

[0075] Furthermore, in the present embodiment, the second portion 30B of the lower case 30, the shield 60, and the upper case 40 are described as being made of an aluminum alloy, but there is no particular limitation as long as they are non-magnetic metals. Also, the second portion 30B of the lower case 30, the shield 60, and the upper case 40 may each be made of a different metal.

[0076] In addition, in this embodiment, an example has been shown in which the lower case 30 and the upper case 40 are integrated via the fastening portion 36, but this is not particularly limited as long as the lower case 30 can be integrated with the upper case 40 separately from the shield 60.

[0077] Furthermore, in the present embodiment, the upper case 40 is formed from a non-magnetic metal, but this is not essential. For example, the upper case 40 may be formed from a resin. As described above, when only the power receiving coil is disposed in the power receiving unit 20 and the entire lower case 30 is formed from a non-conductive resin, it is also possible to form the lower case 30 from a non-conductive resin.

[0078] In addition, the present invention can be implemented in various modifications without departing from the spirit and scope of the present invention. Furthermore, the scope of the present invention is not limited to the above-described embodiment. [Explanation of symbols]

[0079] 10. Non-contact power receiving device 12 Vehicles 14 Bottom 20 Power receiving unit 22 Receiving coil section 30 Lower Case 30A Part 1 (part supporting the receiving coil) 30B Part 2 (part supporting parts other than the receiving coil part) 40 Upper Case 60 Shield

Claims

1. a power receiving unit that is disposed at the bottom of the vehicle and includes a power receiving coil that is disposed opposite a power transmitting coil of the power transmitting device to be able to receive power in a non-contact manner; a lower case that is attached to a bottom of the vehicle, that houses and supports a vehicle lower side of the power receiving unit, and that supports at least a power receiving coil portion in the power receiving unit, the power receiving coil portion being made of resin; a shield supported by the lower case and arranged to surround the lower case in a bottom view, the shield being made of a non-magnetic metal; A non-contact power receiving device comprising:

2. The non-contact type power receiving device according to claim 1 , wherein the resin is non-conductive.

3. 3. The non-contact type power receiving device according to claim 1, wherein a portion of the lower case that supports a portion of the power receiving unit other than the power receiving coil portion is made of a non-magnetic metal.

4. 3. The non-contact type power receiving device according to claim 1, wherein the power receiving unit is composed only of the power receiving coil, and the lower case is entirely made of resin.

5. The non-contact type power receiving device according to any one of claims 1 to 4, further comprising an upper case that is attached to a bottom of the vehicle, houses the vehicle upper side of the power receiving unit, is integrated with the lower case to store the power receiving unit, and is made of a non-magnetic metal.

6. 6. The non-contact type power receiving device according to claim 1, wherein the shield is supported only by the lower case attached to the bottom of the vehicle.

7. 7. The non-contact type power receiving device according to claim 1, wherein the non-magnetic metal is an aluminum alloy.

8. 8. The non-contact type power receiving device according to claim 1, wherein the resin is a glass fiber reinforced plastic.

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