JP2014107915A - Non-contact power supply system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress an influence by disturbance light such as solar light and illumination in a non-contact power supply system, and to detect a foreign substance existent on an upper face of a cabinet accommodating a coil with high accuracy.SOLUTION: In a cabinet 120 (coil case 121) installed on a parking space with an accommodated power transmission coil 12, a foreign substance sensor is disposed to detect a foreign substance existent on the upper face of the coil case 121. The foreign substance sensor includes a light emitting unit 161 and a light receiving unit 162, and is disposed in such a manner that detection light traveling from the light emitting unit 161 to the light receiving unit 162 bridges across the upper face of the coil case 121. In this case, the foreign substance sensor outputs detection light from the light emitting unit 161 obliquely to an upward direction, and the light receiving unit 162 is configured in such a manner that an incidence plane to which the detection light from the light emitting unit 161 is incident faces downward.

Description

  The present invention relates to a non-contact power feeding system.

  2. Description of the Related Art Conventionally, a non-contact power supply system that supplies power in a non-contact manner by magnetic coupling of a pair of coils is known (for example, see Patent Document 1). This non-contact power supply system is being applied to an electric vehicle such as an electric vehicle, for example. One coil connected to an AC power source is installed in a parking space such as a power supply stand, and the electric vehicle is connected to a battery. The other coil is installed. Then, by using the coil on the parking space side as the primary coil and the coil on the electric vehicle side as the secondary coil, the electric power is supplied from the parking space side AC power source to the vehicle side battery by the magnetic coupling of the pair of coils. Can be supplied.

  By the way, when used in such a non-contact power feeding system, the coil is placed in a target location in a state of being housed in the housing, but since it is used outdoors, unintentionally, Foreign matter such as iron may be present on the surface. If power is supplied in such a state, the foreign matter may be heated by the magnetic flux generated in the coil, and the foreign matter may be in a high temperature state.

  According to the system disclosed in Patent Document 1, the profile information indicating the content of the influence of the entry of a foreign object into the space that affects wireless power transmission on a predetermined parameter related to wireless power transmission is held in advance. Then, the acquired predetermined parameter or the content of the change of the predetermined parameter over time is compared with the profile information, and it is determined that the intrusion of foreign matter has occurred according to the comparison result.

  Patent Document 2 discloses a method (light curtain) in which detection light (light rays) from a light emitter to a light receiver are arranged in parallel and a target is detected based on whether or not any of the detection light is blocked. ) Is disclosed.

JP 2010-252498 A JP 2010-133503 A

  However, according to the technique for optically detecting a foreign object, ambient light such as sunlight or illumination may reach the light receiver, which may cause a decrease in foreign object detection accuracy.

  The present invention has been made in view of such circumstances, and an object of the present invention is to suppress the influence of ambient light such as sunlight and illumination in a non-contact power supply system, and to accurately remove foreign matter existing in a casing that houses a coil. Is to detect.

In order to solve such a problem, the present invention provides a non-contact power feeding system in which a foreign matter sensor for detecting foreign matter existing on the upper surface of the casing is arranged in a casing that houses a first coil. The foreign matter sensor is arranged so that the detection light from the light emitting unit to the light receiving unit straddles the upper surface of the housing. Here, the foreign matter sensor constitutes the light receiving unit so that the detection light from the light emitting unit is inclined and output in the upward direction, and the incident surface on which the detection light from the light emitting unit is incident faces downward.

  According to the present invention, since the incident surface of the detection light in the light receiving unit faces downward, disturbance light does not easily enter the incident surface. Thereby, since the influence by disturbances, such as sunlight and illumination, can be suppressed, the foreign material which exists in the housing | casing which accommodates a 1st coil can be detected accurately.

Block diagram schematically showing the configuration of the non-contact power supply system Schematic diagram showing the state of the power transmission coil and housing installed in the parking space The schematic diagram which shows the structure of the housing | casing and foreign material sensor which concern on 1st Embodiment. Schematic diagram showing the configuration of the housing and foreign matter sensor The schematic diagram which shows the structure of the housing | casing and foreign material sensor which concern on 2nd Embodiment. The schematic diagram which shows the structure of the housing | casing and foreign material sensor which concern on 2nd Embodiment.

(First embodiment)
FIG. 1 is a block diagram schematically showing the configuration of the non-contact power feeding system according to this embodiment. The non-contact power supply system includes a power supply device 100 that is a ground-side unit and a vehicle 200 that includes a vehicle-side unit, and supplies power from the power supply device 100 in a non-contact manner and charges a battery 28 provided in the vehicle 200. It is.

  The power supply apparatus 100 is installed in a charging stand or the like provided with a parking space for the vehicle 200 and supplies power to the vehicle 200. The power supply apparatus 100 is mainly configured by a power control unit 11, a power transmission coil 12, a wireless communication unit 14, and a control unit 15.

The power control unit 11 is a circuit for converting AC power transmitted from the AC power source 300 into high-frequency AC power and transmitting the power to the power transmission coil 12. The power control unit 11 includes a rectification unit 111, a PFC (Power Factor Correction) circuit 112, an inverter 113, and a sensor 114.

  The rectifying unit 111 is electrically connected to the AC power source 300 and rectifies the output AC current from the AC power source. The PFC circuit 112 is a circuit for improving the power factor by shaping the output waveform from the rectifying unit 111, and is connected between the rectifying unit 111 and the inverter 113. The inverter 113 is a power conversion device including a smoothing capacitor, a switching element such as an IGBT, a PWM control circuit, and the like. The inverter 113 converts a direct current into a high-frequency alternating current based on a control signal from the control unit 15, and transmits the transmission coil 12. To supply. The sensor 114 is connected between the PFC circuit 112 and the inverter 113 and detects current and voltage.

  The power transmission coil 12 is a coil for supplying power in a non-contact manner to the power reception coil 22 on the vehicle 200 side, and is configured by winding a conductive wire made of a conductor such as metal. The power transmission coil 12 is provided at a target location such as a parking space where the vehicle 200 is parked, and faces the lower side of the power receiving coil 22 on the vehicle 200 side when the vehicle 200 is parked at a specified position in the parking space.

The wireless communication unit 14 performs bidirectional communication with the wireless communication unit 24 provided on the vehicle 200 side. Since the communication frequency between the wireless communication unit 14 and the wireless communication unit 24 is set to a frequency higher than the frequency used in the vehicle peripheral device such as intelligence ski, the wireless communication unit 14 and the wireless communication unit 24 Even if it communicates between, vehicle peripheral devices are hard to receive the interference by the said communication. For communication between the wireless communication unit 14 and the wireless communication unit 24, for example, various wireless LAN methods are used, and communication methods suitable for long distances are used.

  The control unit 15 has a function of comprehensively controlling the power supply apparatus 100. For example, the control unit 15 controls the power control unit 11, the power transmission coil 12, and the wireless communication unit 14. The control unit 15 transmits a control signal to start power supply to the vehicle 200 side or receives power from the vehicle 200 side through communication between the wireless communication unit 14 and the wireless communication unit 24. Receive control signals. The control unit 15 performs switching control of the inverter 113 based on the detection current of the sensor 114 and controls electric power supplied from the power transmission coil 12. As the control unit 15, a microcomputer mainly composed of a CPU, a ROM, a RAM, and an I / O interface can be used.

  Moreover, in the relationship with this embodiment, the control part 15 is provided with the foreign material detection part 150, when this is caught functionally. The foreign object detection unit 150 detects a foreign object existing between the power transmission coil 12 and the power reception coil 22 based on a detection signal from the foreign object sensor 16 described later. Details of the foreign matter sensor 16 will be described later.

  The vehicle 200 includes a power receiving coil 22, a wireless communication unit 24, a charging control unit 25, a rectifying unit 26, a relay unit 27, a battery 28, an inverter 29, a motor 30, and a notification unit 32. Yes.

  The power receiving coil 22 is a coil for receiving electric power in a non-contact manner from the power transmitting coil 12 on the power supply apparatus 100 side, and is configured by winding a conductive wire made of a conductor such as metal. The power receiving coil 22 is provided at a target location, for example, between the rear wheels on the bottom surface (chassis) or the like of the vehicle 200, and when the vehicle 200 is parked at a specified position in the parking space, It faces the upper side of the power transmission coil 12.

  The wireless communication unit 24 performs bidirectional communication with the wireless communication unit 14 provided on the power supply apparatus 100 side.

  The rectifying unit 26 is connected to the power receiving coil 22 and is configured by a rectifying circuit that rectifies AC power received by the power receiving coil 22 into direct current.

  The relay unit 27 includes a relay switch that is turned on and off under the control of the charging control unit 25. The relay unit 27 can disconnect the high-power system including the battery 28 from the low-power system of the power receiving coil 22 and the rectifying unit 26 serving as a charging circuit unit by turning off the relay switch.

  The battery 28 is a power source of the vehicle 200 and is configured by electrically connecting a plurality of secondary batteries, for example.

  The inverter 29 is a power conversion device including a switching element such as an IGBT, a PWM control circuit, and the like. The inverter 29 converts a direct current output from the battery 28 into an alternating current based on the control signal, and converts the alternating current power to the motor 30. Supply. The motor 30 is composed of, for example, a three-phase AC motor, and is a drive source for driving the vehicle 200.

The notification unit 32 includes a warning lamp, a display of a navigation system, a speaker, and the like, and is arranged on an instrument panel or the like in the vehicle interior. The notification unit 32 outputs light, an image, sound, or the like to the user based on the control by the charging control unit 25.

  The charging control unit 25 has a function of controlling charging of the battery 28. For example, the charging control unit 25 controls the wireless communication unit 24 and the notification unit 32. The charging control unit 25 receives a control signal for starting power supply from the power supply apparatus 100 side through communication of the wireless communication unit 24 and the wireless communication unit 14, or receives a control signal for receiving power from the vehicle 200 side. Or send to.

  Although not shown, the charging control unit 25 is connected to a controller that controls the entire vehicle 200 via a CAN communication network. The controller manages the switching control of the inverter 29 and the state of charge (SOC) of the battery 28. When the charging control unit 25 determines full charging based on the SOC of the battery 28 obtained from the controller, the charging control unit 25 transmits a control signal to the power supply apparatus 100 to end charging.

  In the non-contact power feeding system according to the present embodiment, high-frequency power is transmitted between the power transmission coil 12 and the power receiving coil 22 in a non-contact state by electromagnetic induction. That is, when a voltage is applied to the power transmission coil 12, magnetic coupling occurs between the power transmission coil 12 and the power reception coil 22, and power is supplied from the power transmission coil 12 to the power reception coil 22.

  In such a non-contact power supply system, when the power transmission coil 12 on the power supply device 100 side or the power reception coil 22 on the vehicle 200 side is installed at a target location, from the viewpoint of coil protection and security, Housed inside.

  FIG. 2 is a schematic diagram illustrating a state of the power transmission coil 12 and the housing 120 installed in the parking space. FIG. 3 is a schematic diagram showing the configuration of the housing 120 and the foreign matter sensor 16. The power transmission coil 12 on the power supply apparatus 100 side is fixedly provided in a parking space (ground) in a state of being housed in the housing 120. The power transmission coil 12 has a structure wound in a spiral shape in a plane parallel to the ground, and the power reception coil 22 faces the upper surface of the housing 120 during power feeding.

  In the present embodiment, the upper surface of the housing 120 is set to have a slope shape. The vehicle 200 having the power receiving coil 22 mounted between the rear wheels at the bottom of the vehicle body is parked in the parking space by rear parking at the time of charging. On the premise of this parking mode, the upper surface of the housing 120 is set to have a slope shape such that the side corresponding to the vehicle rear FR is upward from the side corresponding to the vehicle center FC.

  The housing 120 includes a box-shaped coil case 121 that accommodates the power transmission coil 12 and an outer cover 122 that covers the coil case 121, and each upper surface side forms the above-described slope shape. An opening 122a is formed on the upper surface of the outer cover 122, and the upper surface 121a of the coil case 121 accommodated inside is exposed from the opening 122a. The opening 122a is set to a size that is slightly smaller than the outer shape of the upper surface 121a of the coil case 121, and the outer peripheral edge of the outer cover 122 projects inward so as to cover the peripheral edge of the upper surface 121a of the coil case 121. It is dressed up.

  The coil case 121 is provided with a drive mechanism (not shown) and is configured to be movable up and down. Thereby, the position of the up-down direction regarding the coil case 121 can be set from two patterns of a lower position and an upper position. When the lower position is set, as shown in FIG. 3, the coil case 121 allows a predetermined gap between the upper surface 121 a and the outer cover 122. On the other hand, when the upper position is set, the upper surface 121a of the coil case 121 comes into contact with the inner surface of the outer cover 122 as shown in FIG. The drive mechanism is controlled by the foreign object detection unit 150 as necessary.

  The housing 120 is provided with a foreign matter sensor 16 (see FIG. 2) that detects foreign matter present on the top surface of the housing 120, specifically, the top surface 121 a of the coil case 121. The foreign matter sensor 16 is a so-called light curtain, and includes a plurality of sensor units 160 that output detection light (light rays).

  The plurality of sensor units 160 are arranged in a direction (vehicle width direction) orthogonal to the front-rear direction of the vehicle 200, and the upper surface 121a of the housing 120 is covered in a planar shape by a plurality of detection lights arranged in the vehicle width direction. Will be. The interval between adjacent detection lights corresponds to the detection resolution by the foreign matter sensor 16 and can be set as appropriate according to the desired resolution. In addition, the plurality of sensor units 160 are arranged so that each detection light is close to the upper surface of the housing 120 in order to detect a foreign object having a small thickness.

  Each sensor unit 160 includes a light emitting unit 161 and a light receiving unit 162. The light emitting unit 161 includes a light emitter that outputs detection light such as infrared light or visible light. The light receiving unit 162 includes a light receiver that receives the detection light from the light emitting unit 161 and outputs the intensity of the detection light as an electrical signal level. In the present embodiment, the detection light output from the light emitter that is the light emitting unit 161 is directly incident on the light receiver that is the light receiving unit 162.

  The light emitting unit 161 and the light receiving unit 162 are arranged to face each other so that the detection light from the light emitting unit 161 to the light receiving unit 162 straddles the upper surface 121a of the coil case 121. Here, the light emitting unit 161 is disposed on the vehicle center FC side of the outer cover 122, the light receiving unit 162 is disposed on the vehicle rear FR side of the outer cover 122, and the detection light is parallel to the front-rear direction of the vehicle 200. doing. That is, when viewed from the housing shape of the housing 120, the light emitting unit 161 is disposed on the lower tilt side of the coil case 121, and the light receiving unit 162 is disposed on the upper tilt side of the coil case 121.

  The light emitting unit 161 and the light receiving unit 162 are arranged at predetermined positions of the outer cover 122, and thus are arranged in the outer peripheral region of the coil case 121. Thereby, when the position of the coil case 121 is set to the lower position, the light emitting unit 161 and the light receiving unit 162 are respectively exposed (see FIG. 3). On the other hand, when the position of the coil case 121 is set to the upper position, the light emitting unit 161 and the light receiving unit 162 are respectively shielded by the presence of the coil case 121 itself (see FIG. 4).

  In addition, as one of the features of the present embodiment, the light emitting unit 161 outputs the detection light while being inclined upward, and the light receiving unit 162 is an incident surface on which the detection light is incident (in this embodiment, the light receiving unit 162). Is set so that the light receiving surface) faces downward. For this reason, the detection light from the light emitting unit 161 to the light receiving unit 162 is set to have an upward gradient in the traveling direction of the detection light corresponding to the slope shape of the housing 120.

  In this non-contact power supply system, the foreign object detection unit 150 in the control unit 15 detects foreign objects prior to the power supply operation or periodically at the time of power supply from the power supply apparatus 100 to the vehicle 200 accompanying charging of the battery 28 of the vehicle 200. I do.

Specifically, first, the foreign object detection unit 150 moves the coil case 121 present at the upper position corresponding to the normal position to the lower position. That is, the foreign matter detection unit 150 lowers the coil case 121 and exposes the light emitting unit 161 and the light receiving unit 162 located around the coil case 121. Next, the foreign object detection unit 150 includes each sensor unit 16.
The 0 light emitting unit 161 is operated, and the detection signal of the light receiving unit 162 is read. When the foreign object detection unit 150 determines that any of the detection lights are blocked based on the output signal of the light receiving unit 162, the foreign object detection unit 150 determines that there is a foreign object. When ending the detection operation, the foreign object detection unit 150 moves the coil case 121 present at the lower position to the upper position. That is, the foreign object detection unit 150 raises the coil case 121 to shield the light emitting unit 161 and the light receiving unit 162.

  In addition, the foreign material detection part 150 can prohibit the start of charge, or can restrict | limit the output from the power transmission coil 12 at the time of electric power feeding operation, when the presence of a foreign material is judged. In addition, the foreign object detection unit 150 performs communication between the wireless communication unit 14 and the wireless communication unit 24 and operates the notification unit 32 of the vehicle 200.

  As described above, in the present embodiment, the foreign matter sensor 16 that detects foreign matter present on the upper surface 121a of the coil case 121 is disposed in the casing 120 (coil case 121) that accommodates the power transmission coil 12 and is installed in the parking space. Has been. The foreign matter sensor 16 includes a light emitting unit 161 and a light receiving unit 162, and arranges the detection light from the light emitting unit 161 to the light receiving unit 162 so as to straddle the upper surface 121a of the coil case 121. The foreign matter sensor 16 configures the light receiving unit 162 so that the detection light from the light emitting unit 161 is output while being inclined upward, and the incident surface on which the detection light from the light emitting unit 161 is incident faces downward.

  In the present embodiment, the incident surface on which the detection light is incident corresponds to the light receiving surface of the light receiver constituting the light receiving unit 162. Disturbance light such as sunlight and illumination is usually emitted from a position higher than the ground, so that the disturbance light is incident on the light receiving surface of the light receiver by facing the light receiving surface of the light receiver downward. It becomes difficult. Thereby, since the influence by disturbances, such as sunlight and illumination, can be suppressed, the foreign material which exists in the housing | casing 120 which accommodates the power transmission coil 12 can be detected accurately.

  Moreover, according to this structure, adhesion of contaminants, such as dust and liquid water, can be suppressed because the light-receiving surface of a light receiver is turned downward. Thereby, it can suppress that the light-receiving surface of a light receiver is soiled with a contaminant, and the detection accuracy and fall of a foreign material are reduced.

  Moreover, in this embodiment, the opening peripheral part of the outer cover 122 becomes the shape protruded inside so that the peripheral part of the upper surface 121a of the coil case 121 may be covered. According to such a configuration, the peripheral edge of the opening of the outer cover 122 serves as a ridge that covers the light receiving unit 162, so that the incidence of disturbance light on the light receiving unit 162 can be effectively restricted.

  Further, in the present embodiment, the upper surface 121a of the coil case 121 is set to have a slope shape that rises upward from the light emitting unit 161 side to the light receiving unit 162 side.

  According to such a configuration, even if liquid water such as rain water adheres to the upper surface 121a of the coil case 121, the liquid water can be flowed by the inclined shape and guided to the lower side of the slope. Thereby, the liquid water can be effectively removed without the liquid water staying on the upper surface 121a of the coil case 121.

  Although not described in the above-described embodiment, the coil case 121 may be formed with a drainage path for draining rainwater that has flowed down to the lower side of the slope in the lateral direction (the left-right direction of the vehicle 200). Thereby, the situation where the liquid water which flowed down the slope remains on the light emitting unit 161 side can be suppressed.

  In the present embodiment, the power transmission coil 12 is a ground-side unit that supplies power to the vehicle 200 in which the power reception coil 22 is mounted on the bottom of the vehicle body. In particular, the power reception coil 22 is mounted between the rear wheels of the vehicle 200. Has been. Here, the foreign matter sensor 16 moves the light receiving unit 162 to the rear of the vehicle 200 with respect to the light emitting unit 161 when the vehicle position when the power transmission coil 12 and the power receiving coil 22 are opposed to each other when power is exchanged is used as a reference. It arranges so that it may be located.

  According to this configuration, the light emitting unit 161 is disposed at a position closer to the center of the vehicle 200 than the light receiving unit 162. In the case 120 whose upper part is covered by the vehicle 200, there are many light emitting elements in the position closer to the center of the vehicle 200 than in the position closer to the rear of the vehicle 200. Therefore, by arranging the light emitting unit 161 at a position where there are few such light emitting elements, it is possible to obtain reliability that the light received by the light receiving unit 162 is the detection light from the light emitting unit 161.

  However, in the present embodiment, the positional relationship between the light receiving unit 162 and the light emitting unit 161 is defined by comparing the rear side of the vehicle 200 with the center side. However, in view of the fact that the central portion of the vehicle 200 has fewer light emitting elements than the position outside it, the light receiving unit 162 is arranged to be located outside the vehicle 200 relative to the light emitting unit 161. That's fine.

  Further, the coil case 121 is configured to be movable up and down by a drive mechanism. Accordingly, when the foreign matter sensor 16 does not detect foreign matter, the coil case 121 is raised and the light emitting unit 161 and the light receiving unit 162 are shielded by the coil case 121. On the other hand, when foreign matter is detected by the foreign matter sensor 16, the coil case 121 is lowered to expose the light emitting unit 161 and the light receiving unit 162.

  According to this configuration, when the foreign matter is not detected, the light emitting unit 161 and the light receiving unit 162 are shielded by the coil case 121 so that contaminants such as rainwater and dust adhere to the light emitting unit 161 and the light receiving unit 162. Can be suppressed. Thereby, it can suppress that the detection precision of a foreign material falls by a contaminant.

(Second Embodiment)
FIG. 5 is a schematic diagram illustrating configurations of the housing 120 and the foreign matter sensor 16 according to the second embodiment. The non-contact power feeding system according to the second embodiment is different from that of the first embodiment in the configuration of the foreign matter sensor 16. The description of the points common to the first embodiment will be omitted, and the following description will be focused on the differences.

  First, in the present embodiment, the upper surface of the housing 120 is set to have a tapered shape with the center position of the power transmission coil 12 as a reference, that is, a slope shape that faces upward toward the center position. The coil case 121 is formed in a ring shape, and a space is provided at the center thereof. On the other hand, the opening 122 a of the outer cover 122 is formed in a circular shape, and is set to a size that is slightly smaller than the outer shape of the upper surface 121 a of the coil case 121. The outer cover 122 has a shape that protrudes inward so as to cover the peripheral edge portion of the upper surface 121 a of the coil case 121.

  The housing 120 is provided with a foreign matter sensor 16 (see FIG. 2) that detects foreign matter present on the top surface of the housing 120, specifically, the top surface 121 a of the coil case 121. The foreign matter sensor 16 is a so-called light curtain, and is composed of a plurality of sensor units 160 each outputting detection light.

The plurality of sensor units 160 are arranged at equal pitches in the circumferential direction of the power transmission coil 12, and the upper surface 121a of the coil unit 121 is covered with a plurality of radial detection lights. Further, the plurality of sensor units 160 are arranged so that the detection light is close to the upper surface of the housing 120 in order to detect a foreign object having a small thickness.

  In the sensor unit 160, the light emitting unit 161 and the light receiving unit 162 are respectively disposed at predetermined positions of the outer cover 122 so that the detection light from the light emitting unit 161 to the light receiving unit 162 straddles the upper surface 121 a of the coil case 121. They are placed opposite to each other. Specifically, the light emitting unit 161 is disposed in the outer peripheral region of the power transmission coil 12, and the light receiving unit 162 is disposed in the inner diameter region of the power transmitting coil 12. For this reason, the detection light in each sensor unit 160 extends in the radial direction of the power transmission coil 12.

  As shown in FIG. 6, the light emitting unit 161 includes a light emitter 161a that outputs detection light such as infrared light or visible light, and a reflection mirror 161b that bends the detection light from the light emitter 161a. On the other hand, the light receiving unit 162 receives the detection light and outputs the intensity of the detection light as an electrical signal level, and a reflection mirror that bends the detection light from the light emitting unit 161 and guides it to the light receiving unit 162a. 162b.

  The light emitter 161a is disposed below the reflection mirror 161b and outputs detection light upward. The detection light output from the light emitter 161a is bent in a predetermined direction by the reflection mirror 161b. This predetermined direction is set according to the light receiving unit 162 corresponding to the light emitting unit 161. When the detection light reflected by the reflection mirror 161b on the light emitting unit 161 side is incident on the reflection mirror 162b on the light receiving unit 162 side, it is bent downward. The light receiver 162a is disposed below the reflection mirror 162b and receives the detection light reflected by the reflection mirror 21. In the present embodiment, the detection light output from the light emitter 161a is configured to enter the light receiver 162a via the reflection mirrors 161b and 162b.

  Further, as one of the features of the present embodiment, the light emitting unit 161 outputs detection light in the upward direction by the reflecting mirror 161b, and the light receiving unit 162 has an incident surface on which the detection light is incident (in this embodiment, a reflecting mirror). 162b) is set to face downward. For this reason, the detection light from the light emitting unit 161 to the light receiving unit 162 has an upward slope in the traveling direction of the detection light corresponding to the slope shape of the housing 120.

  Thus, in the present embodiment, the incident surface on which the detection light is incident corresponds to the reflection mirror 162b that constitutes the light receiving unit 162. Since disturbance light such as sunlight and illumination is usually irradiated from a position higher than the ground, disturbance light is less likely to enter the reflection mirror 162b by facing the reflection mirror 162b downward. Thereby, since the influence by disturbances, such as sunlight and illumination, can be suppressed, the foreign material which exists in the housing | casing 120 which accommodates the power transmission coil 12 can be detected accurately.

  In the present embodiment, the foreign matter sensor 16 has the light receiving unit 162 disposed in the inner diameter region of the power transmission coil 12 and the light emitting unit 161 disposed in the outer peripheral region of the power transmission coil 12. The light receiving unit 162 receives the detection light reflected by the reflection mirror 162b and the reflection mirror 162b that is a reflection member that reflects the detection light from the light emission unit 161 and guides it downward. And a light receiver 162a.

As shown in the present embodiment, when the light receiving unit 162 is disposed in the inner diameter region of the power transmission coil 12, the light receiving unit 162 is likely to be magnetically affected. In this regard, according to the present embodiment, the light receiver 162a is disposed below the power transmission coil 12 by guiding the detection light downward by the reflection mirror 162b. Thereby, the magnetic influence which the light receiver 162a receives can be suppressed.

  Further, according to such a configuration, even when the disturbance light L3 (see FIG. 6) is incident on the reflection mirror 162b, it is difficult to reach the light receiver 162a unless it passes through a predetermined optical path. For this reason, it can suppress that disturbance light is received by the light receiver 162a.

  In the present embodiment, the light emitting unit 161a is also disposed below the light emitting unit 161 using the reflection mirror 161b. However, in view of the magnetic influence, it is sufficient to adopt the above-described configuration only for the light receiving unit 162. . However, a form using a reflecting mirror may be applied to the first embodiment.

  In the present embodiment, the light emitters 161a and the light receivers 162a are arranged in a one-to-one number. However, by appropriately setting the angle of the reflection mirror 162b of the light receiving unit 162, a plurality of light emitters 161a is provided. The detection lights L1 and L2 (FIG. 3) may be received by a single light receiver 162a. Thereby, since the number of the light receivers 162a can be reduced, the number of assembling steps and costs can be reduced. In a case where a plurality of light emitters 161a share a single light receiver 162a, when detecting a foreign object, the plurality of light emitters 161a are not turned on all at once, but are turned on in order, so Detection can be performed.

  In each of the above-described embodiments, the foreign matter sensor 16 is applied to the housing 120 that houses the power transmission coil 12 disposed on the ground side. For example, if the power receiving coil 22 is disposed on the ceiling of the vehicle 200 and the power transmitting coil 12 is disposed so as to face the power receiving coil 22, the foreign object sensor 16 is applied to the housing that houses the power receiving coil 22. Also good. Of course, from the viewpoint of detecting foreign matter, the foreign matter sensor 16 may be applied to any of the casings that house individual coils with respect to the pair of coils facing each other.

  The unit on the vehicle 200 side of the non-contact power feeding system is mounted on an electric vehicle, but may be a vehicle such as a hybrid vehicle.

  The contactless charging system to which the contactless charging apparatus of the present invention is applied has been described above, but the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the invention. Needless to say.

DESCRIPTION OF SYMBOLS 100 Electric power feeder 11 Power control part 12 Power transmission coil 120 Case 121 Coil case 121a Upper surface 122 Outer cover 122a Opening 15 Control part 16 Foreign object sensor 160 Sensor unit 161 Light emission unit 161a Light emitter 161b Reflective mirror 162 Light reception unit 162a Light receiver 162b Reflective mirror 200 vehicles

Claims (6)

A first coil that transfers power in a contactless manner with the second coil by magnetic coupling;
A housing that houses the first coil and is installed at a predetermined destination;
A foreign matter sensor that includes a light emitting unit and a light receiving unit, and that disposes detection light from the light emitting unit to the light receiving unit so as to straddle the top surface of the housing in order to detect foreign matter present on the top surface of the housing; With
The foreign matter sensor is configured such that the detection light from the light emitting unit is tilted upward and output, and the light receiving unit is configured such that an incident surface on which the detection light from the light emitting unit is incident faces downward. A contactless power supply system.   The non-contact power feeding system according to claim 1, wherein an upper surface of the housing is set to have a slope shape that rises upward from the light emitting unit side to the light receiving unit side. The first coil is a ground-side unit that supplies electric power to a vehicle on which the second coil is mounted on the bottom of a vehicle body,
The foreign matter sensor is positioned on the outer side of the light emitting unit with respect to the vehicle position when power is exchanged between the second coil and the first coil. The non-contact power feeding system according to claim 1, wherein the light receiving unit is disposed in the non-contact power feeding system. The first coil has a structure wound spirally in a plane parallel to the ground,
4. The foreign object sensor according to claim 1, wherein the light receiving unit is disposed in an inner diameter region of the first coil, and the light emitting unit is disposed in an outer peripheral region of the first coil. Contactless power supply system described in 1. The light receiving unit is
A reflecting member that reflects detection light from the light emitting unit and guides it downward;
The contactless power feeding system according to claim 4, further comprising: a light receiver that is positioned below the reflecting member and receives the detection light reflected by the reflecting member.   The casing is configured to be movable up and down by a driving mechanism. When the foreign object is not detected by the foreign object sensor, the casing is raised to raise the light emitting unit, the light receiving unit, and the 6. The light emitting unit and the light receiving unit according to claim 1, wherein the light emitting unit and the light receiving unit are exposed by shielding the case and detecting the foreign matter by the foreign matter sensor. Contactless power supply system described in 1.

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