vehicle

Abstract

To obtain a vehicle capable of preventing intrusion of flux leakage into a vehicle cabin without a movable mechanism when power is received from external power transmission part in a non-contact manner.SOLUTION: A vehicle 10 includes an underbody 14 constituting a bottom part of a vehicle body 12 and formed by resin member, a power reception part 22 arranged at the lower part of the underbody 14 and receiving power from a power transmission part 56 provided outside in a non-contact manner, and a shield member 40 arranged on the underbody 14 at the upper part of the power reception part 22. Therefore, when receiving power from the power transmission part 56 in a non-contact manner, the power reception part 22 can block intrusion of flux leakage into a vehicle cabin by the shield member 40 arranged on the underbody 14. Thus, even if no movable mechanism is provided, the intrusion of the flux leakage into the vehicle cabin can be prevented.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vehicle equipped with a power receiving unit that receives electric power in a contactless manner. [Background technology]

[0002] Patent Document 1 discloses a vehicle equipped with a power receiving coil that receives power in a non-contact manner from a power transmitting unit provided outside the vehicle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-80594 Summary of the Invention [Problem to be solved by the invention]

[0004] In a vehicle that receives power contactlessly as described above, it is assumed that the power receiving unit will be installed under the vehicle. Therefore, high-frequency power at a level of approximately 100 kHz is received on the underside of the power receiving unit, which may result in leakage magnetic flux generated by the power reception entering the vehicle interior. In the vehicle described in Patent Document 1, a cover member with a magnetic shielding function is provided that can be moved between a closed state and an open state, thereby blocking leakage magnetic flux from the power transmitting unit. However, the vehicle described in Patent Document 1 is provided with a movable mechanism using an actuator for opening and closing the cover. While a vehicle that can receive power contactlessly has the advantage of not requiring a movable mechanism, there is room for improvement in measures against leakage magnetic flux.

[0005] In consideration of the above, the present invention aims to provide a vehicle that can prevent leakage magnetic flux from entering the vehicle cabin when receiving power contactlessly from an external power transmission unit without providing a movable mechanism. [Means for solving the problem]

[0006] The vehicle according to the present invention as set forth in claim 1 comprises an underbody that constitutes the bottom of the vehicle body and is made of a resin member, a power receiving unit that is disposed under the underbody and that receives power contactlessly from an external power transmitting unit, and a power receiving unit that is disposed on the underbody above the power receiving unit. , made of non-magnetic metal and a shield member. A vehicle according to the present invention as described in claim 2 is a vehicle having the configuration as described in claim 1, in which the shielding member is arranged over the entire surface of the underbody, and a power cable connected to the storage device is arranged under the underbody with the shielding member located on top.

[0007] The vehicle according to the present invention described in claim 1 includes an underbody that constitutes the bottom of the vehicle body and is made of a resin member, a power receiving unit that is disposed under the underbody and that receives power contactlessly from an externally provided power transmitting unit, and a shielding member that is disposed on the underbody above the power receiving unit. Therefore, when the power receiving unit receives power contactlessly from the power transmitting unit, the shielding member that is disposed on the underbody that is made of a resin member and is disposed above the power receiving unit can block leakage magnetic flux from entering the vehicle cabin. This makes it possible to prevent leakage magnetic flux from entering the vehicle cabin without providing a moving mechanism. [Effects of the Invention]

[0008] As described above, the vehicle according to the present invention has the excellent effect of being able to prevent leakage magnetic flux from entering the vehicle interior when receiving power contactlessly from an external power transmission unit without the need for a movable mechanism. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is an explanatory diagram illustrating a schematic configuration of a vehicle according to an embodiment of the present invention; [Figure 2] 5 is an explanatory diagram for explaining a method for determining the thickness of a shield member in a vehicle according to an embodiment of the present invention. FIG. [Figure 3] FIG. 2 is an explanatory diagram for explaining a magnetic field. DETAILED DESCRIPTION OF THE INVENTION

[0010] A vehicle 10 according to one embodiment of the present invention will be described with reference to the drawings. Note that the arrow UP in Fig. 1 indicates the upper side in the vehicle vertical direction, and the arrow FR indicates the front side in the vehicle longitudinal direction. In the following description, the vertical direction and the longitudinal direction refer to the up and down in the vehicle vertical direction and the front and rear in the vehicle longitudinal direction, respectively.

[0011] The vehicle 10 according to this embodiment is, for example, an electric vehicle such as a fuel cell electric vehicle (FCEV) or a battery electric vehicle (BEV). The vehicle 10 according to this embodiment does not have any parts made of magnetic metal such as steel disposed below the vehicle 10, such as an exhaust pipe.

[0012] 1, a vehicle 10 includes a vehicle body 12, a power receiving device 20, a drive control unit 30, and a shield member 40. In this embodiment, the power receiving device 20 and the drive control unit 30 are shown schematically for the purpose of explanation, and are different from the actual arrangement in the passenger compartment of the vehicle 10.

[0013] The vehicle body 12 includes an underbody 14 that forms the bottom of the vehicle body 12, i.e., the underside of the vehicle body 12. In this embodiment, the underbody 14 is formed of a resin, which is a non-conductive material, for the purpose of reducing the weight of the vehicle 10, and is formed of fiber reinforced plastics (FRP) as an example.

[0014] The power receiving device 20 includes a power receiving section 22, a power cable 24, a rectifier 26, and a power storage device 28, and receives power contactlessly from the power transmitting device 50. The power transmitting device 50 will now be described.

[0015] The power transmission device 50 is installed in an external power supply facility, and is installed near the ground G if the power supply facility is outdoors, or near the floor F if the facility is indoors. The power transmission device 50 includes an AC power source 52, a driver circuit unit 54, and a power transmission unit 56. The AC power source 52 is, for example, a power source supplied from a power distribution network owned by an electric power company, and has a frequency of 50 Hz or 60 Hz.

[0016] The driver circuit section 54 is electrically connected to the AC power supply 52 , converts the power received from the AC power supply 52 into high-frequency power of about 100 kHz, and transmits the power to the power transmitting section 56 .

[0017] Power transmitting unit 56 is provided near ground G or floor surface F, and receives high-frequency power converted in driver circuit unit 54. Power transmitting unit 56 is configured to be able to transmit power to power receiving unit 22 in a non-contact manner by resonating with power receiving unit 22 via an electromagnetic field. Power transmitting unit 56 is configured by a self-resonant coil (LC resonant coil) configured to resonate with power receiving unit 22 via an electromagnetic field at a high frequency of approximately 100 kHz.

[0018] Next, the power receiving device 20 will be described. The power receiving unit 22 is fixedly installed below the underbody 14, i.e., outside the vehicle cabin. The power receiving unit 22 is configured to be able to receive power from the power transmitting unit 56 of the power transmitting device 50 in a non-contact manner by resonating with the power transmitting unit 56 via an electromagnetic field. As an example, the power receiving unit 22 is configured by a self-resonant coil (LC resonant coil) configured to resonate with the power transmitting unit 56 via an electromagnetic field at a high frequency of approximately 100 kHz, similar to the power transmitting unit 56. The power receiving unit 22 and the LC resonant coil of the power transmitting unit 56 are aligned so as to generate magnetic flux linkage.

[0019] The power cable 24 transmits the power received by the power receiving unit 22 to the power storage device 28 via the rectifier 26 .

[0020] Rectifier 26 is connected to power receiving unit 22, and converts AC current received from power transmitting unit 56 into DC current and transmits the DC current to power storage device 28. Although not shown, a converter that adjusts the voltage of the DC current is provided between rectifier 26 and power storage device 28. If a converter is not provided, a matching device for matching impedance may be provided in power transmitting device 50.

[0021] The power storage device 28 is a rechargeable DC power source and is configured, for example, by a secondary battery such as a lithium-ion or nickel-metal hydride battery, or a large-capacity capacitor. The power storage device 28 is disposed, for example, inside a vehicle interior such as a luggage compartment, i.e., above the underbody 14. The power cable 24, the power storage device 28, and the rectifier 26 are electrically connected directly or indirectly to the power receiving unit 22, and are therefore covered with a member (not shown) capable of shielding against electromagnetic waves. For example, a non-magnetic metal such as aluminum that has an electromagnetic wave shielding effect, or a cloth material, etc., can be used as this member.

[0022] The drive control unit 30 includes a power control unit 32 and a motor drive unit 34. The power control unit 32 includes a converter connected to the power storage device 28 and an inverter connected to the converter. The converter boosts the DC current transmitted from the power storage device 28 and transmits the boosted current to the inverter. The inverter converts the DC current transmitted from the converter into AC current and transmits the AC current to the motor drive unit 34.

[0023] The motor drive unit 34 is configured with a three-phase AC motor or the like, and is connected to the inverter of the power control unit 32 and is driven by AC current transmitted from the inverter. The motor drive unit 34 functions as both an electric motor and a generator.

[0024] 1, vehicle 10 of this embodiment is provided with a shielding member 40 on underbody 14 above power receiving unit 22. Shielding member 40 is formed into a rectangular plate shape with one side measuring approximately 800 mm and made of a material capable of shielding electromagnetic waves, and is made of a non-magnetic metal such as aluminum, for example.

[0025] Fig. 2 is an explanatory diagram for explaining a method for determining the thickness t of the shielding member 40. As shown in Fig. 2, the thickness t of the shielding member 40 is determined by the shielding effect determined by the skin depth d and the threshold magnetic field strength inside the vehicle cabin. Here, the skin depth d is the distance at which the electromagnetic field incident on a certain material is attenuated by 1 / e, or approximately 0.37 times, and is expressed by the following formula (1):

[0026]

number

[0027] In the above formula (1), d is the skin depth, ρ is the resistivity, f is the frequency, μ r indicates the relative permeability, respectively.

[0028] According to the above formula (1), the shielding effect in a high-frequency magnetic field is determined by the skin depth d. If the thickness t of the shielding member 40 is equal to or greater than the skin depth d, the shielding effect against electromagnetic waves can be obtained. That is, as shown in FIG. 2, when a magnetic field H is incident on a shielding member 40 formed with a thickness t equal to or greater than the skin depth d, the magnetic field H is attenuated after passing through the shielding member 40. Even if a steel material S is provided near the shielding member 40, the shielding member 40 can shield the magnetic field H from entering the steel material S. Since the shielding member 40 of this embodiment is made of aluminum, a nonmagnetic metal, the resistivity ρ is 2.65×10-8 (Ω·m) and the relative permeability is approximately 1, providing a shielding effect. However, resin, a nonconductive material, does not provide a shielding effect because its resistivity ρ is higher than that of nonmagnetic metals.

[0029] (Action and effect) Next, the effects of this embodiment will be described.

[0030] As described above, in order for power receiving unit 22 to receive power from power transmitting unit 56 in a non-contact manner, a high frequency magnetic field of about 100 kHz is required.

[0031] Fig. 2 is an explanatory diagram for explaining a magnetic field. For example, consider the case where a magnetic field H passes through a cylindrical member W formed with a radius R, as shown in Fig. 2, and an eddy current i flows. The loss due to the magnetic flux linkage of this member W is expressed by the following formula (2).

[0032]

number

[0033] In the above formula (2), P is the loss per unit volume, B is the magnetic flux density, H is the magnetic field, f is the frequency, R is the radius of the member W, ρ is the resistivity, μ r indicates the relative permeability, respectively.

[0034] As shown in equation (2), the loss per unit volume P is calculated by multiplying the relative permeability μ r and is proportional to the square of the frequency f. Therefore, when using a high-frequency magnetic field H of about 100 kHz, in order to suppress the loss P as much as possible, the relative permeability μ r It is desirable not to use magnetic conductive materials such as steel, which have a relatively large value of . If a magnetic conductive material is present near the power receiving unit 22, magnetic flux will concentrate on the magnetic conductive material, reducing charging efficiency.

[0035] In this embodiment, since the underbody 14 is formed of fiber reinforced plastic (FRP), even if a high frequency magnetic field of about 100 kHz is generated so that the power receiving unit 22 receives power contactlessly from the power transmitting unit 56, magnetic flux does not concentrate on the underbody 14, thereby preventing a decrease in charging efficiency.

[0036] However, if the underbody 14 is made of fiber reinforced plastic (FRP), fiber reinforced plastic does not have a shielding effect against the magnetic field H, and therefore leakage magnetic flux will enter the vehicle interior when the power receiving unit 22 receives power from the power transmitting unit 56. If the underbody is made of a magnetic conductive material, the underbody will attenuate the magnetic field H, and the leakage magnetic flux will not enter the vehicle interior, but as described above, this will result in a decrease in charging efficiency.

[0037] In the present embodiment, a shield member 40 made of a non-magnetic metal such as aluminum is provided on the underbody 14 above the power receiving unit 22. Therefore, when the power receiving unit 22 receives power contactlessly from the power transmitting unit 56, the shield member 40 disposed on the underbody 14 above the power receiving unit 22 can block leakage magnetic flux from entering the vehicle compartment. This makes it possible to prevent leakage magnetic flux from entering the vehicle compartment without providing a moving mechanism.

[0038] Furthermore, in this embodiment, the shield member 40 is provided on the underbody 14, so there is no need to provide a shield member outside the vehicle cabin, which is subject to harsh environmental conditions such as flying stones, rust, and contact with the road surface, and therefore the cost required to replace the shield member can be reduced.

[0039] (Supplementary explanation of the embodiment) In the above embodiment, the power receiving unit 22 and the power transmitting unit 56 are configured by self-resonant coils (LC resonant coils), but the present invention is not limited to this. For example, they may be configured by high-dielectric disks made of high-dielectric-constant materials such as titanium oxide (TiO), barium titanium oxide (BaTiO), and lithium tantalate (LiTaO).

[0040] Furthermore, in the above embodiment, the vehicle 10 is an electric vehicle such as a fuel cell electric vehicle (FCEV) or a battery electric vehicle (BEV), but the present invention is not limited to this. The vehicle 10 may also be a vehicle equipped with an internal combustion engine, such as a hybrid electric vehicle (HEV) or a plug-in hybrid electric vehicle (PHEV). In this case, when installing components made of magnetic conductive material such as steel, such as an exhaust pipe, under the vehicle 10, the effects of the present invention can be achieved by providing a sufficient distance between the power receiving unit 22 and the components. Specifically, it is preferable to provide a distance of 200 mm or more between the power receiving unit 22 and the components made of magnetic metal.

[0041] Furthermore, in the above embodiment, the shield member 40 is disposed on a portion of the underbody 14, including the upper portion of the power receiving unit 22, but the present invention is not limited to this. The shield member 40 may be disposed on the entire underbody 14, including the upper portion of the power receiving unit 22. In this case, leakage magnetic flux can be more effectively prevented from entering the vehicle interior when power is received contactlessly from an external power transmitting unit.

[0042] In this case, it is preferable that power storage device 28 is disposed on shield member 40, and power cable 24, which is connected from power receiving unit 22 to power storage device 28 via rectifier 26, is disposed below underbody 14, above which shield member 40 is located. By disposing power cable 24 below underbody 14, above which shield member 40 is located, in this manner, leakage magnetic flux from power cable 24 can be prevented from entering the vehicle interior.

[0043] The above describes one embodiment of the present invention, but the present invention is not limited to the above, and it goes without saying that it can be implemented in various other modified forms within the scope of the gist of the present invention. [Explanation of symbols]

[0044] 10 vehicles 12 Body 14 Underbody 22 Power receiving unit 56 Power Transmission Unit 40 Shielding material

Claims

1. an underbody that constitutes the bottom of the vehicle body and is formed of a resin member; a power receiving unit disposed under the underbody and configured to receive power in a wireless manner from an external power transmitting unit; a shield member disposed on the underbody above the power receiving unit and made of a non-magnetic metal; Vehicles including.

2. The shield member is disposed over the entire surface of the underbody, The vehicle according to claim 1 , wherein a power cable connected to the power storage device is arranged under the underbody, above which the shield member is located.

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