JPH10106867A - Charging system for electric motor car - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve cooling efficiency of a coil. SOLUTION: A primary coil 32 is constituted by winding a conducting pipe 34 around a primary side core 33. Cooling water is circulated in the conducting pipe 34, and cooled by a radiator 52 in a charging power source 50. A core line of a charging power cable 40 is connected with both ends of the conducting pipe 34 via current-carrying terminals 37, and excites the primary coil 32. Refrigerant flows in a charging coupler 30 through a refrigerant circulation path. The heat generated in the coupler 30 is eliminated to the outside of a connector by the refrigerant, and dissipated by a radiating means. Cooled refrigerant flows again to cool the charging coupler 30, passing the refrigerant circulation path.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging system for charging an electric vehicle using electromagnetic induction, and more particularly to a charging system having an improved coil cooling structure.

[0002]

2. Description of the Related Art This type of charging system has various advantages because it can supply electric power to an electric vehicle in a non-contact manner without passing through electric contacts, and various structures are considered. The basic structure is described in, for example, Japanese Patent Application Laid-Open No. 5-258962.
JP-A-5-260671, JP-A-6-14470
As disclosed in each of the publications, the primary and secondary cores are each wound with a coil, and when charging an electric vehicle, an alternating current is passed through the primary coil and an electromotive force is applied to the secondary coil by electromagnetic coupling. This is an application of the transformer principle of causing

[0003] In such a charging system, there is a strong demand for miniaturization of the whole, and to achieve this, it is necessary to sufficiently cool the heat generated from the primary coil and the core of the charging coupler. Thus, for example, US Pat.
No. 412,304, as shown in FIGS. 9 and 10, a core 2 is housed in a housing 1 and a primary coil 3 is wound around an outer periphery of the core 2 and is arranged along the primary coil 3. A large number of cool air passages 4 and exhaust ports 5 connected thereto are formed. In this housing 1,
A cool air supply hose 6 is connected to supply outside air into the cool air flow path 4, and the outside air flows through the cool air flow path 4 and flows out from the exhaust port 5, thereby discharging heat inside the charging coupler. I can do it.

[0004]

However, in the above-described structure, since only the outside air is sent into the vicinity of the heat-generating portion, the cooling efficiency is still insufficient, and there is a problem that heat is easily trapped inside the charging coupler. Was.

[0005] The present invention has been made based on the above circumstances, and an object of the present invention is to provide a charging system for an electric vehicle capable of improving cooling efficiency and reducing the size or the capacity.

[0006]

According to a first aspect of the present invention, there is provided a charging system for an electric vehicle, wherein a charging coupler is mounted on a receiving portion provided on the electric vehicle, and a primary coil is excited by a charging power supply to receive the receiving portion. In the charging system that generates an electromotive force in the secondary coil on the side and charges the power storage device of the electric vehicle with the electromotive force, a refrigerant circulation path that circulates the refrigerant through the charging coupler and heat generated by the refrigerant flowing through the refrigerant circulation path And a heat radiating means for discharging the cooling water to cool the charging coupler by circulation of the refrigerant.

A second aspect of the present invention is characterized in that, in the first aspect of the present invention, the refrigerant circulation tube forming a part of the refrigerant circulation path is integrated with a power cable for supplying power to the charging coupler. . A third aspect of the present invention is characterized in that, in the first or second aspect of the invention, a radiator integrated into a charging power supply device is used as a radiating means.

According to a fourth aspect of the present invention, in any one of the first to third aspects of the present invention, the primary coil of the charging coupler is constituted by a conductive pipe, and the conductive pipe is used as a part of a refrigerant circulation path to supply a refrigerant. It has a characteristic where it flows.

[0009]

According to the first aspect of the present invention, the refrigerant flows in the charging coupler through the refrigerant circulation path, and the heat generated in the charging coupler is removed to the outside of the connector by the refrigerant. Then, the heat is released by the heat radiating means, and the cooled refrigerant flows through the refrigerant circuit again to cool the charging coupler.

According to the present invention, since the cooled refrigerant repeatedly flows inside the charging coupler, the heat generated in the charging coupler can be efficiently removed. In addition, since the refrigerant circulates in the refrigerant circulation path, there is no waste, and a gas refrigerant or a liquid refrigerant other than air, which is excellent in cooling capacity, can be used, which is more convenient for improving the cooling efficiency.

According to the second aspect of the present invention, since the refrigerant circulation tube for flowing the refrigerant is integrated with the electric power cable, handling during charging of the electric vehicle is facilitated. According to the third aspect of the present invention, since the radiator is integrated into the charging power supply device, the entire system can be made compact. Furthermore, according to the invention of claim 4, since the coil is formed by the conductive pipe, the coil itself can be used as a part of the refrigerant circulation path. As a result, not only is the whole compact, but also cooling can be performed near the heat source, resulting in excellent cooling efficiency.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION

<First Embodiment> A first embodiment of the present invention will be described below with reference to FIGS.

The overall configuration of the present system is as shown in FIG. 1. A receiving portion 12 which can be opened and closed by, for example, a lid 11 is formed outside the vehicle body of the electric vehicle EV. It can be inserted and set. A charging power cable 40 is connected to the charging coupler 30, and is connected to a charging power supply 50. The charging power supply 50 is provided with a high-frequency power supply 51 for outputting a high-frequency voltage of, for example, 100 kHz, and includes an air-cooled radiator 52 and a cooling fan 53 as radiating means for radiating heat from cooling water as a refrigerant described later. It is arranged integrally inside.

The receiving portion 12 of the electric vehicle EV is provided with a coupler receiving case 13 forming a concave portion 13a which is open outward, and a secondary coil unit 20 is disposed therein. This secondary coil unit 20
Is formed by winding a secondary coil 22 around a secondary core 21 made of, for example, ferrite, and is cooled by an air-cooling fan 23 provided in the vehicle body. The output terminal of the secondary coil 22 is connected to a charging circuit for charging a power battery (not shown), which is a power storage device for powering the electric vehicle EV, and a high-frequency voltage induced by the secondary coil 22 is provided. The power battery can be charged by rectifying the power.

The secondary core 21 has a shape such as a quadrangular prism bent into an L-shape, and is fixed to the coupler receiving case 13 in a shape in which the long side of the L-shape is horizontal. The short side extends downward and the lower end is the coupler receiving case 1
3 and slightly projecting into the recess 13a. Further, the tip side of the long side of the L-shape is exposed toward the inside of the recess 13 a through an opening 13 b formed at the front end of the receiving case 13. A leaf spring 14 is attached to the bottom of the recess 13a of the receiving case 13, and the recess 13a
The charging coupler 30 inserted therein is urged upward (toward the secondary coil unit 20).

On the other hand, the charging coupler 30 is configured by housing a primary coil 32 and a primary side core 33 in a housing 31. The primary side core 33 is the same as the secondary side core 21, and is fixed to the housing 31 in a shape in which the long side of the L shape is along the inside of the housing 31,
The short side of the L-shape extends upward at the base side of the housing 31, and its upper end surface penetrates the housing 31 and protrudes to the outside. Further, the tip side of the long side of the L-shape is exposed on the upper surface through an opening 31 a formed at the front end of the housing 31. Therefore, when the charging coupler 30 is inserted into the recess 13 a of the receiving case 13 of the electric vehicle EV, the top surface of the long side of the primary core 33 faces the lower end surface of the short side of the secondary core 21. State and the primary side core 33
The upper surface of the short side of the secondary core 21 is opposed to the lower surface of the distal end of the long side of the secondary core 21. And the recess 13a of the receiving case 13
The opposing surfaces of the cores 21 and 33 are almost in contact with each other by biasing the charging coupler 30 upward by the leaf spring 14 provided on the bottom surface of the. A circuit is formed.

A conductive pipe 34 is wound a plurality of times around the short side of the primary core 33 so that the primary coil 32
Are formed. The conductive pipe 34 is made of a copper alloy in this embodiment, and has a diameter of 5 mm and a thickness of 0.5, for example.
mm and the inside diameter is about 25 mm. Also,
On the inner peripheral side of the primary coil 32, for example, heat-conductive silicon grease 35 or the like is applied between the primary core 33 and the primary core 33, whereby the silicone grease 35 is applied between the primary core 33 and the primary coil 32. The primary coil 32 is wound around the primary core 33 so as to be able to conduct heat with higher heat transferability than the state where no coating is performed. Although not shown, the inner and outer surfaces of the conductive pipe 34 are insulated by, for example, enamel coating.

As shown in FIG. 4, the charging power cable 40 has two cores 41,
The two refrigerant supply tubes 42 constituting the outward path and the return path are wound around the outer periphery side of the first through an insulating layer in a helical shape in opposite directions, respectively, and a jacket layer 43 is formed on the outer periphery thereof. Is integrated. The refrigerant supply tube 42 is
It is made of a heat-resistant and flexible synthetic resin such as a silicone resin. Each core 41 of the charging power cable 40 is connected to the output terminal of the high frequency power supply 51 on the charging power supply 50 side, and the refrigerant supply tube 42 on the outward path is connected to the circulation pump 54 in the charging power supply 50. At the same time, the refrigerant supply tube 42 on the return path is connected to the radiator 52.

The connection structure between the primary coil 32 and the charging power cable 40 is as shown in FIG. That is, the refrigerant supply tube 42 is connected to the end of the conductive pipe 34.
Are connected to the conductive pipe 34 by a pipe clamp 36 in a watertight manner. Thus, a closed refrigerant circulation path including the conductive pipe 34, the refrigerant supply tube 42, and the radiator 52 is formed, and cooling water is sealed therein as a refrigerant. A plurality of drain caps 44 are integrally formed at the connection end of the refrigerant supply tube 42, and water droplets flow from the conductive pipe 34 side due to dew condensation on the conductive pipe 34 or the like. Even when water drops flow from the tube 42 side, the water drops 44 can prevent the water drops from flowing to the opposite side. The one of the two refrigerant supply tubes 42 on the outward path is connected to the end of the conductive pipe 34 on the inner peripheral side of the primary coil 32, and the refrigerant supply tube 42 on the return path is connected to the outer periphery of the primary coil 32. The cooling water flows from the inner peripheral side to the outer peripheral side of the primary coil 32.

In the conductive pipe 34, near the connection with the refrigerant supply tube 42, an energizing terminal 37 is connected, for example, by brazing, and the core 41 of the charging power cable 40 is fixed by caulking. I have. On the charging coupler 30 side, the charging power cable 40 is led out through a tubular portion 38 also serving as a handle, which is integrally provided on the base side of the housing 31.

The present embodiment has the above configuration, and its operation will be described as follows. When charging the electric vehicle EV, first, the charging coupler 30 is connected to the receiving portion 12 of the vehicle body.
Insert inside. Then, the charging coupler 30 is inserted all the way into the receiving case 13, where the coupler receiving case 1 is inserted.
The charging coupler 30 is pressed against the secondary coil unit 20 side by the leaf spring 14 in 3, and the cores 21 and 33 are joined to form a closed-loop magnetic circuit. Then, when a power switch (not shown) of the charging power supply 50 is turned on, the circulating pump 54 and the cooling fan 53 are activated, and the high-frequency power supply 51 operates to apply a high-frequency voltage to the primary coil 32 through the charging power cable 40. . When the primary coil 32 is excited, an electromotive force is generated in the secondary coil 22, and based on this, the electric vehicle EV
Is charged.

When a high-frequency current flows through the primary coil 32, the conductive pipe 34 and the primary core 33 constituting the primary coil 32 generate heat. However, since the circulation pump 54 is operated as described above, the cooling water flows through the inside of the conductive pipe 34 through the refrigerant supply tube 42 on the outward path of the charging power cable 40, and this flows again on the return path side of the charging power cable 40. Radiator 5 through refrigerant supply tube 42 of
A circulating flow of cooling water is returned from the second to the circulation pump 54. For this reason, the heat generated in the conductive pipe 34 is immediately transmitted to the cooling water flowing in the inside thereof, and is carried to the radiator 52 side, where it is cooled and circulated by the cooling fan 53. Therefore, even if the conductive pipe 34 generates Joule heat during charging, the conductive pipe 34 is immediately cooled, so that the temperature of the primary coil 32 can be prevented from rising significantly. The heat generated in the primary core 33 is transferred to a conductive pipe 34 that forms the inner peripheral side of the primary coil 32.
To the radiator 52 also by the cooling water flowing therethrough. Therefore, the temperature rise of the primary side core 33 can be reliably prevented. The secondary coil unit 20
Is cooled by the air cooling fan 23 in the vehicle body.

As described above, according to the present embodiment, the following effects can be obtained. (1) Since the primary coil 32 is made of a conductive pipe and cooling water is passed inside, the coil conductor itself, which is a source of Joule heat, is cooled from the inside, and extremely efficient cooling is possible. It is. Moreover, the refrigerant supply tube 4
Since the cooling system is a water cooling system in which cooling water is circulated through the cooling device 2, the cooling efficiency is higher than that of a conventional air cooling system that only flows outside air, and the size and capacity of the charging coupler 30 can be reduced.

In this embodiment, a high-frequency current of 100 kHz is applied to the primary coil 32, and the current depth due to the skin effect is calculated to be about 0.3 mm from the surface. Therefore, even if the coil conductor is hollow, the electric resistance does not increase and does not cause a decrease in efficiency or heat generation. Rather, effective cooling utilizing the hollow shape is possible. (2) By filling the space between the primary coil 32 and the primary side core 33 with silicon grease 35, the primary coil 32
Is thermally wrapped around the primary core 33, so that the heat generated in the primary core 33 is also smoothly transmitted to the conductive pipe 34, where it is cooled. The rise can also be suppressed effectively. (3) Since the coolant supply tube 42 is wound around the outer periphery of the core wire 41 and integrated with the charging power cable 40, the core wire 41 can be cooled, and only one cable needs to be handled. Charging work is simplified. In addition, since the radiator 52 is built in the charging power supply 50, the entire charging facility becomes compact. Further, since the cooling water is circulated while being cooled by the radiator 52, wasteful use of the refrigerant is eliminated, which is economical. (4) In addition, since the cooling water is caused to flow from the inner peripheral side to the outer peripheral side of the primary coil 32, the whole is adapted to the situation that the inner peripheral side is close to the primary side core 33 and is likely to become high temperature. It can be cooled efficiently and uniformly. (5) Since the insulating layer is formed on the inner peripheral surface of the conductive pipe 34, water having conductivity can be used as a coolant, and the material cost is low and the sealing structure is relatively simple. And cost can be reduced as a whole. However, the present invention is not limited to the use of water as a refrigerant, and it is a matter of course that various oils and hydrocarbon solvents such as chlorofluorocarbon may be used.

<Second Embodiment> FIGS. 5 to 7 show a second embodiment of the present invention.

In the present embodiment, a receiving portion 60 is provided at the front of the electric vehicle, and a charging coupler 80 can be inserted therein. As shown in FIGS. 5 and 6, the receiving portion 60 is provided below a slit 62 formed in a front portion of a bonnet 61 of the vehicle body.
0 is arranged in a facing state so that the charging coupler 80 can be inserted therebetween. Secondary coils 71 are wound around the secondary cores 70, respectively, and are connected to a charging circuit (not shown).

On the other hand, the charging coupler 80 is connected to the primary core 8.
A primary coil 83 is wound around the housing 2, and these are housed in a resin housing 81.
4 are integrally formed (see FIGS. 6 and 7). The charging power cable 40 having the same structure as that of the first embodiment is connected to the handle portion 84. The core wire 41 of the charging power cable 40 is connected to a primary coil 83 wound around a primary core 82 and supplied with power from a charging power supply 50. By passing a high-frequency current from the charging power supply 50 to the primary coil 83 with the charging coupler 80 inserted, power can be transmitted to the secondary coil 71 by an electromagnetic induction phenomenon.

As shown in FIG. 6, inside the housing 81 of the charging coupler 80, on both sides of the primary coil 83, an annular refrigerant flow path 8 insulated from the primary coil 83 is provided.
5 are formed. The coolant passage 85 is connected to the handle portion 84 and is divided into an inflow-side passage 87 and an outflow-side passage 88 by a partition wall 86 formed in the hollow handle portion 84. The inflow-side channel 87 is connected to the charging power cable 40.
Connected to the outward path side of the refrigerant supply tube 42 integrated with
The outflow-side flow path 88 is connected to the return path side of the refrigerant supply tube 42.

In the above configuration, to charge the electric vehicle, the charging coupler 80 is inserted into the receiving portion 60 through the slit 62 of the bonnet 61. Then, as in the first embodiment, the primary coil 83 is excited, and the pump is driven to circulate the cooling water in the refrigerant circulation path. Thereby, the cooling water is supplied to the refrigerant supply tube 4 on the outward path.
2 passes through the refrigerant flow path 85 on the outward path formed in the housing 81 of the charging coupler 80 and passes through the refrigerant flow path 85 on the return path side.
And returns to the radiator 52. In this process, the cooling water deprives the heat of the primary coil 83 and the primary side core 82 to raise the temperature,
This is radiated by the radiator 52 in the charging power supply 50. As a result, similarly to the first embodiment, the entire charging coupler 80 is maintained at a low temperature.

<Third Embodiment> FIG. 8 shows a third embodiment of the present invention, which differs from the above embodiments in that the structure of the radiator 90 is improved.

That is, between the refrigerant supply tube 42 on the return path provided on the charging power cable 40 and the refrigerant supply tube 42 on the outward path, a meandering metal pipe radiator 91 is formed. Is provided. The cooling water in the refrigerant supply tube 42 passes through the radiator 91 and is sent out to the refrigerant supply tube 42 on the outward path by the circulation pump 54.

The radiator 91 is provided with a radiator tank 92.
, And a low-boiling-point refrigerant such as Freon is sealed in the tank 92. A number of radiating fins 93 are erected around the outer periphery of the radiating tank 92, and cooling air can be sent from the cooling fan 53 to the fins 93.

In this configuration, when the cooling water is circulated through the charging coupler by the circulation pump 54, the low-boiling-point refrigerant is heated by the heated cooling water to rise in temperature, and a part of the refrigerant is boiled. The boiling low-boiling-point refrigerant is condensed and dropped on the inner wall of the heat radiation tank 92, and the tank 92 is cooled by the heat radiation fins 93. With such a configuration, a sufficient heat dissipation area in the radiator 90 can be ensured, so that the cooling efficiency can be further improved.

<Other Embodiments> The present invention is not limited to the embodiments described above and illustrated in the drawings. For example, the following embodiments are also included in the technical scope of the present invention. In addition to the following, various changes can be made without departing from the scope of the invention. (1) In each of the first and second embodiments, water is used as the refrigerant. However, in the present invention, since a closed refrigerant circulation path is used, a low-boiling refrigerant such as Freon, or A refrigerant that cannot be released into the atmosphere, such as a gas refrigerant, can also be used. (2) When a water-based refrigerant is used, the following measures can be applied as a measure against freezing in consideration of use in cold regions or use in winter.

The antifreeze is mixed with the refrigerant.

At the end of charging, the cooling water is automatically drained. In this case, in order to make the drainage more reliable, compressed air may be sent to the flow path of the cooling water after the drainage.

An anti-freeze valve is provided in the flow path of the cooling water so that the cooling water is automatically drained when the temperature drops to a temperature at which there is a possibility of freezing.

A heater is provided in the flow path of the cooling water, and when the temperature drops to a temperature at which there is a possibility of freezing, the heater is energized and heated. (3) In the first embodiment, the conductive pipe 34 has a round cross section. However, the present invention is not limited to this, and a conductive pipe having a square cross section may be used. By doing so, the coil can be wound in close contact with the primary core, so that the heat transfer with the core is improved and the cooling characteristics of the core can be improved. (4) In each of the above embodiments, the refrigerant is caused to flow inside the conductive pipe. However, the present invention is not limited to this. The coil and the core may be cooled by flowing the refrigerant also to the outside.
A coolant flow path may be formed through the core to allow the coolant to flow therethrough. . (5) The conductive pipe is not limited to being wound in two layers as in the above embodiment, may be wound in one layer, or may be wound in three layers or more. In the single-layer winding, heat transfer with the core is improved and contributes to cooling. In the case of two or more layers, a heat conductive material can be filled between the layers to effectively transfer heat. (6) Each core on the primary side or the secondary side may be provided with fins for cooling. In this case, the core may be integrally formed of the same material, or a metal fin formed of a material having excellent heat conductivity such as aluminum may be attached to the core in an insulated state. (7) The heat radiating means is not limited to providing the heat radiator in the power supply device as in the above-described embodiment. For example, when a structure in which the heat radiator is integrated with the power cable can be expected to sufficiently release heat from the cable. The cable can also be used as a heat radiating means. (8) The refrigerant supply path is not necessarily integrated with the power cable, but may be configured as a separate refrigerant supply hose.

[Brief description of the drawings]

FIG. 1 is a side view schematically showing a charging system of the present invention.

FIG. 2 is a longitudinal sectional view of a charging coupler and a receiving portion according to the first embodiment of the present invention.

FIG. 3 is an enlarged side view showing a connection portion of the conductive pipe.

FIG. 4 is a partially broken perspective view showing the charging power cable.

FIG. 5 is a perspective view schematically showing a charging system according to a second embodiment of the present invention.

FIG. 6 is a vertical sectional view showing the state of insertion of the charging coupler.

FIG. 7 is a sectional view of the charging coupler.

FIG. 8 is a sectional view showing a radiator according to a third embodiment of the present invention.

FIG. 9 is a sectional view of a charging coupler showing a conventional example.

FIG. 10 is an enlarged sectional view of a charging coupler showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 12 ... Receiving part 20 ... Secondary coil unit 21 ... Secondary side core 22 ... Secondary coil 30 ... Charging coupler 31 ... Housing 32 ... Primary coil 33 ... Primary side core 34 ... Conductive pipe 40 ... Charging power cable 42 ... Refrigerant Supply tube 45 ... Refrigerant flow path 50 ... Charging power supply 51 ... Charging high frequency power supply 52 ... Radiator 53 ... Cooling fan 54 ... Cooling pump

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Akashi Arisaka 1-3-1 Shimaya, Konohana-ku, Osaka-shi, Osaka Sumitomo Electric Industries, Ltd. (72) Inventor Toshiro Shimada 1-chome, Shimaya, Konohana-ku, Osaka-shi, Osaka 1-3 No. Sumitomo Electric Industries, Ltd.

Claims (4)

[Claims] 1. A charging coupler is mounted on a receiving portion provided on an electric vehicle, and a primary coil provided on the charging coupler is excited by a charging power supply to generate an electromotive force in a secondary coil on the receiving portion side. In the charging system for charging the power storage device of the electric vehicle by the electromotive force, a refrigerant circulation path for circulating a refrigerant through the charging coupler and a radiator for releasing heat from the refrigerant flowing in the refrigerant circulation path are provided. A charging system for an electric vehicle, wherein the charging coupler is cooled by circulation of a refrigerant. 2. The electric device according to claim 1, wherein a refrigerant circulation tube forming a part of the refrigerant circulation path is integrated with a power cable for supplying power to a primary coil of the charging coupler. Car charging system. 3. The charging system for an electric vehicle according to claim 1, wherein the heat radiating means comprises a radiator integrated into the charging power supply device. 4. The charging coil according to claim 1, wherein a primary coil of the charging coupler is formed of a conductive pipe, and the conductive pipe flows through the refrigerant as a part of a refrigerant circuit. Electric vehicle charging system.