JP2014239175A - Non-contact power transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-contact power transmission device, having a high coupling coefficient between coils, preferable from viewpoints of efficiency, EMC, and human body protection.SOLUTION: The non-contact power transmission device transmits power between an infrastructure side coil 10 and a mobile side coil 30 on the basis of mutual inductive action of electromagnetic induction. Between the infrastructure side coil 10 and the mobile side coil 30, a pair of coupling cores 20 that magnetically couples the infrastructure side coil 10 and the mobile side coil 30 are provided.

Description

  The present invention relates to a non-contact power transmission device that transmits power between a moving body side coil and an infrastructure side coil mounted on a moving body such as an electric vehicle.

As a device for supplying electric power to a moving body such as an electric vehicle or conversely receiving electric power from the moving body side, a method of connecting the infrastructure side and the moving body side via a contact-type connector is generally used. is there.
However, since the insertion and removal of the connector is troublesome, a system for transmitting electric power in a non-contact manner using the principle of electromagnetic induction has been developed.

As this device, alternating current is passed through the ring coil on the infrastructure side placed on the ground, and the magnetic flux generated by this is restored to the current by the principle of electromagnetic induction by the ring coil on the mobile body side mounted on the lower surface of the mobile body. In addition, a device that obtains electric power on the moving body side in a non-contact manner is known (see, for example, Patent Document 1).
According to this method, there is an advantage that there is no need to insert and remove like a contact type connector, and there is a small risk of electric shock due to electric leakage even during flooding.
Note that non-contact is a technical term used to mean that power is not transmitted by a current that is conducted through a contact, and does not mean that a cover or the like that is not involved in conduction is not in physical contact.

JP 2010-93180 A

However, when the non-contact power transmission device described in Patent Document 1 is used, this device is attached to the bottom of a vehicle that is a moving body. In the first place, the bottom of the vehicle is grounded to avoid a collision with an obstacle. Therefore, the gap between the infrastructure coil and the automobile coil cannot be made very small.
For this reason, the coupling coefficient between both coils cannot be increased.
Since the efficiency of power transmission by electromagnetic induction can be increased as the coupling coefficient is higher, there is a problem that the lower coupling coefficient causes the efficiency to deteriorate.
In addition, since the low coupling coefficient means that the leakage magnetic flux is large, there is also a problem that it is not preferable from the viewpoint of EMC (electromagnetic compatibility), leakage magnetic field, and human body protection against an electric field.

  The present invention has an object to solve such problems, and has a high coupling coefficient between the infrastructure side coil and the moving body side coil, which is preferable from the viewpoint of efficiency, EMC, and human body protection. An object is to provide a transmission apparatus.

A non-contact power transmission device according to the present invention is provided with an infrastructure side coil having a rod-shaped core and a winding around which a conducting wire is wound, and is provided in a moving body and approaches the infrastructure side coil. A movable body side coil having a rod-shaped core and a winding around which a conductive wire is wound, and based on a mutual dielectric action of electromagnetic induction, between the infrastructure side coil and the movable body side coil. A non-contact power transmission device that transmits power at
A pair of connection cores that magnetically connect the infrastructure side coil and the mobile body side coil are provided between the infrastructure side coil and the mobile body side coil.

  According to the non-contact power transmission device according to the present invention, since the pair of connection cores that magnetically connect the infrastructure side coil and the mobile body side coil are provided between the infrastructure side coil and the mobile body side coil, In addition, a magnetic circuit of a loop circuit is possible, a generation of leakage magnetic flux is suppressed, a coupling coefficient is high, and a contactless power transmission device that is preferable from the viewpoint of efficiency, EMC, and human body protection can be obtained.

It is front sectional drawing of the non-contact electric power transmission apparatus which concerns on Embodiment 1 of this invention. It is a bottom sectional view of the moving body side coil of the non-contact power transmission device of FIG. 1, and is a view when viewed from the infrastructure side coil.

  Hereinafter, embodiments of the non-contact power transmission apparatus of the present invention will be described with reference to the drawings.

Embodiment 1 FIG.
FIG. 1 is a front sectional view of a non-contact power transmission apparatus according to Embodiment 1 of the present invention, and FIG. 2 is a bottom sectional view of a moving body side coil 30.
This non-contact power transmission device includes an infrastructure-side coil 10 provided in a power feeding area, a mobile body-side coil 30 that is attached to the bottom of an automobile that is a mobile body and faces the infrastructure-side coil 10 in close proximity, A pair of connecting cores 20 provided between the side coil 10 and the moving body side coil 30 and magnetically connecting the infrastructure side coil 10 and the moving body side coil 30 are provided.

The moving body-side coil 30 includes a rectangular base 35 attached to the bottom of an automobile (not shown), a ring-shaped protrusion 36 protruding on the infrastructure-side coil 10 side on the base 35, and the protrusion A rod-shaped core 31 attached to 36 and a winding 32 around which a conducting wire is wound are provided.
The core 31 has extended cores 33 extending along the moving direction of the automobile at both ends.
A portion of the protruding portion 36 on the side of the extension core 33 on the traveling direction side of the automobile (the arrow direction in FIG. 2) is a triangular guide portion 34 whose opposing side portions are enormous in the outward direction.

  The infrastructure side coil 10 includes a case 13 fixed to the ground of the power supply area, a rod-like core 11 supported in the case 13 via a support member (not shown), and a conductor wound around the core 11. And a wound winding 12.

The connecting core 20 has a core portion 23 composed of a spherical core element 22 that is a first core element that is adjacent to each other and a concave core element 21 that is a second core element, and each core portion 23 alternately. And an elastic tube 24 that covers the connection core body 26 that is stacked so as to be connected to the main body 26.
The spherical core element 22 has a spherical shape as a whole, and a convex portion 25 is formed along the entire circumference of the spherical core element 22. The concave core element 21 is slidably in surface contact with the hemispherical surface of the spherical core element 22 on both sides.

  An electromagnetic characteristic measuring device (not shown) that can measure the electromagnetic characteristics of the winding 32 is connected to the winding 32 of the moving body side coil 30.

Next, the operation of the non-contact power transmission apparatus having the above configuration will be described.
First, the vehicle is moved so that the moving body side coil 30 approaches the infrastructure side coil 10 placed in the power feeding area.
At this time, the guide part 34 of the moving body side coil 30 mounted on the lower surface of the automobile pushes and expands the tip end of the connection core 20 derived from the infrastructure side coil 10, and the tip ends of the pair of left and right connection cores 20 respectively move to the moving body side coil. The left and right expansion cores 30 are guided so as to be in contact with each other.

Thereafter, it is detected whether the connecting core 20 is correctly in contact with the expansion core 33 and whether there is an abnormality between the infrastructure side coil 10 and the moving body side coil 30 using the electromagnetic characteristic specifying device.
Then, after confirming that the contact is correct and that there is no abnormality, a magnetic field proportional to the current is generated around the winding 12 by energizing the infrastructure side coil 10 with alternating current as an exciting current. The formed magnetic flux links the windings 32 of the moving body side coil 30 via the connecting core 20, and as a result, an electromotive force is generated in the moving body side coil 30.
The moving body side coil 30 is connected to an in-vehicle battery (not shown), and the electric power generated by the moving body side coil 30 is charged in the in-vehicle battery.

As described above, according to the contactless power transmission device according to this embodiment, a pair of magnetically connecting the infrastructure side coil 10 and the mobile body side coil 30 between the infrastructure side coil 10 and the mobile body side coil 30. Since the connecting core 20 is provided, the core 11 of the infrastructure side coil 10 and the core 31 of the moving body side coil 30 do not have a large magnetic gap through the connecting core 20 and are closed-loop magnetism having a small magnetic resistance. A circuit is formed. It is inevitable that some gaps occur between the adjacent core portions 23 and the contact portion between the connecting core 20 and the expansion core 33, but these are larger than the large gaps between the coils of the device described in the background art section. The increase in magnetoresistance due to the small gap is negligibly small.
Therefore, the coupling coefficient between the infrastructure side coil 10 and the moving body side coil 30 is high, the efficiency and EMC are improved, and the influence on the human body with respect to the leaking magnetic field and electric field can be suppressed.

  Further, since the connecting core 20 is flexible, a closed-loop magnetic circuit is ensured even if a slight positional shift occurs in the left-right direction of the moving body-side coil 30 with respect to the infrastructure-side coil 10 (left-right direction with respect to the traveling direction of the automobile). Is done.

  Moreover, since the core 31 of the moving body side coil 30 has the extended core 33 extended in the moving direction of the automobile at both ends, the moving body side coil 30 extends in the front-rear direction (the moving direction of the automobile) with respect to the infrastructure side coil 10. A closed-loop magnetic circuit is ensured even if a slight misalignment occurs.

  Moreover, since the moving body side coil 30 has the guide part 34 which guides the edge part of the connection core 20 to the expansion core 33, the edge part of the connection core 20 is reliably guide | induced to the expansion core 33. FIG.

  Further, since the connecting core 20 includes the spherical core element 22 and the concave core element 21 in surface contact with the hemispherical surface of the spherical core element 22, the moving body side coil 30 in the left-right direction with respect to the infrastructure side coil 10. A closed loop magnetic circuit can be secured by following a simple configuration with respect to a slight positional deviation.

In addition, in order to produce an inexpensive and high-performance magnetic material such as ferrite, an upper and lower split mold is used. Therefore, some mold shift and parting line are unavoidable during molding.
On the other hand, since this spherical core element 22 has a convex portion 25 formed along its great circle, even if the spherical core element 22 rotates, the parting line is formed on the sliding surface of the concave core element 21. To prevent the occurrence of inconveniences such as floating of the sliding surface between the spherical core element 22 and the concave core element 21 and increase of the magnetic resistance due to mold misalignment and parting line. Can do.

  In addition, since the connecting core body 26 configured by connecting adjacent core portions 23 to each other is entirely covered with the elastic tube 24, the connecting core body 26 is protected and the life of the connecting core 20 is extended. be able to.

  In addition, since the moving body side coil 30 includes an electromagnetic characteristic measuring device that is connected to the winding 32 and measures the electromagnetic characteristics of the winding 32, if the connecting core 20 is correctly in contact with the expansion core 33, the moving body side coil 30 is provided. The inductance of the coil 30 is increased, and by monitoring the inductance, it can be detected whether or not the coil 30 is correctly connected.

  In addition, the electromagnetic characteristic measuring apparatus measures the electromagnetic characteristics of the winding 32 by flowing currents of a plurality of frequencies through the winding 32, so that a small animal, a can, or the like is interposed between the infrastructure side coil 10 and the moving body side coil 30. Abnormalities such as the presence of foreign matter and contact can be detected.

In the above embodiment, the expansion core 33 and the guide part 34 are provided in the moving body side coil 30, but the expansion core 33 and the guide part 34 may be provided in the infrastructure side coil 10.
Further, the moving body side coil 30 is made to move forward or backward by the automobile and the moving body side coil 30 is opposed to the infrastructure side coil 10. In this case, the moving body side coil 30 is rotated by 180 ° in accordance with the forward or backward movement of the automobile. It can respond by installing in
Further, if an alternating current is passed through the winding 32 of the moving body side coil 30, an induced current flows through the winding 12 of the infrastructure side coil 10 due to the magnetic flux generated thereby, so that power is transferred from the moving body side coil 30 to the infrastructure side coil 10. It can also be transmitted.
Further, the electromagnetic characteristic measuring device may be provided in the infrastructure side coil 10 together with the moving body side coil 30 or may be provided only in the infrastructure side coil 10.
Moreover, although the automobile has been described as the moving body, it is not limited to the automobile, and may be, for example, a train.

Further, even if the connecting core 20 is provided with the core portion 23 only at one position on the lower end portion, the deformation of the core portion 23 becomes large, the load of the elastic tube 24 becomes large, and the life becomes a problem. Applicable.
Further, although the contact surface of the core portion 23 is a spherical shape, it may be a structure that allows a large contact area between magnetic bodies even when bent, and may be a cylindrical surface shape or a barrel surface shape.
In addition, a composite magnetic material formed by mixing rubber-like resin and magnetic powder may be used for the connection core, and although the performance and durability are slightly reduced, a similarly deformable connection core is obtained at a low cost. be able to.

  DESCRIPTION OF SYMBOLS 10 Infrastructure side coil, 11 core, 12 winding, 13 Case, 20 Connection core, 21 Concave core element, 22 Spherical core element, 23 Core part, 24 Elastic tube, 25 Convex part, 26 Connection core main body, 30 Mobile body side coil 31 cores, 32 windings, 33 expansion cores, 34 guide parts, 35 bases, 36 protrusions

A non-contact power transmission device according to the present invention is provided with an infrastructure side coil having a rod-shaped core and a winding around which a conducting wire is wound, and is provided in a moving body and approaches the infrastructure side coil. A movable body side coil having a rod-shaped core and a winding around which a conductive wire is wound, and based on a mutual dielectric action of electromagnetic induction, between the infrastructure side coil and the movable body side coil. A non-contact power transmission device that transmits power at
A pair of connecting cores that magnetically connect the infrastructure side coil and the mobile body side coil are provided between the infrastructure side coil and the mobile body side coil ,
The connecting core is flexible;
The core of the movable body side coil or the core of the infrastructure side coil has extended cores extending in the moving direction of the movable body at both ends .

As described above, according to the contactless power transmission device according to this embodiment, a pair of magnetically connecting the infrastructure side coil 10 and the mobile body side coil 30 between the infrastructure side coil 10 and the mobile body side coil 30. Since the connecting core 20 is provided, the core 11 of the infrastructure side coil 10 and the core 31 of the moving body side coil 30 do not have a large magnetic gap through the connecting core 20 and are closed-loop magnetism having a small magnetic resistance. A circuit is formed. It is inevitable that some gaps occur between the adjacent core portions 23 and the contact portion between the connecting core 20 and the expansion core 33, but these are larger than the large gaps between the coils of the device described in the background art section. The increase in magnetoresistance due to the small gap is negligibly small.
Therefore, it is possible coupling coefficient between the infrastructure side coil 10 and the movable body side coil 30 is high, the efficiency, EMC is improved, also to suppress the influence of the human body with respect to the leakage magnetic field, electric field.

Claims (10)

A rod-shaped core, and an infrastructure-side coil having a winding around which a conducting wire is wound, and a movable body and close to and opposed to the infrastructure-side coil, the rod-shaped core and the core A non-contact power transmission device for transmitting power between the infrastructure-side coil and the mobile-side coil based on a mutual dielectric action of electromagnetic induction. There,
A non-contact power transmission device in which a pair of connection cores that magnetically connect the infrastructure side coil and the moving body side coil are provided between the infrastructure side coil and the moving body side coil.   The contactless power transmission device according to claim 1, wherein the connection core is flexible.   The non-contact power transmission device according to claim 1, wherein the core of the moving body side coil or the core of the infrastructure side coil has extended cores extending in a moving direction of the moving body at both ends.   The non-contact power transmission device according to claim 3, wherein the infrastructure-side coil or the moving body-side coil having the extension core has a guide portion that guides an end of the connection core to the extension core.   The contactless power transmission device according to any one of claims 1 to 4, wherein the connection core includes a core portion including a first core element and a second core element that are adjacent to each other and are bendable.   6. The first core element is a spherical core element having a spherical shape as a whole, and the second core element is a concave core element in surface contact with a hemispherical surface of the spherical core element. Non-contact power transmission device.   The contactless power transmission device according to claim 6, wherein the spherical core element has a convex portion formed along a great circle.   The contactless power transmission device according to any one of claims 5 to 7, wherein a connecting core main body configured by connecting adjacent core portions is covered with an elastic tube.   9. The electromagnetic characteristic measuring device according to claim 1, wherein at least one of the moving body side coil and the infrastructure side coil includes an electromagnetic characteristic measuring device connected to the winding and measuring an electromagnetic characteristic of the winding. Non-contact power transmission device.   The non-contact power transmission device according to claim 9, wherein the electromagnetic characteristic measurement device measures the electromagnetic characteristics of the winding by flowing currents having a plurality of frequencies through the winding.

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