JPH10309041A - Magnetic coupler for charging electric automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the degree of coupling between primary and secondary coils. SOLUTION: In a magnetic coupler which is constituted to insert and set the primary unit 30 of an electric automobile into and in the secondary unit 20 of the automobile, a primary coil 32 is constituted so that the coil 32 may be inserted into a secondary coil 22 and primary and secondary cores 21 and 31 are constituted to form a closed magnetic circuit which is closed below the coils 32 and 22. Most of the magnetic flux excited in the primary coil 32 is coupled with the secondary coil 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a magnetic coupling device for an electric vehicle for charging an electric vehicle using electromagnetic induction.

[0002]

2. Description of the Related Art In recent years, non-contact type charging systems utilizing electromagnetic induction have been developed as charging systems for electric vehicles.
One example is disclosed in JP-A-6-14470. As shown in FIG. 17, this is a configuration including a primary unit 1 connected to a charging power source and a secondary unit 2 arranged on the vehicle body side of the electric vehicle. The primary core 3 and the secondary core 4 are joined to each other to form a single magnetic circuit. In this state, an alternating current is applied to the primary coil 5 and an electromotive force is applied to the secondary coil 6 in a non-contact manner. Is generated.

[0003]

However, in the above configuration, the degree of magnetic coupling between the two coils 5 and 6 is not yet sufficient.
Actually, there is a problem that a loss of 1 to 2% occurs. Since such a loss is lost as heat, when electric power of, for example, 30 kWh is transmitted to enable short-time charging of the electric vehicle, heat generation of 300 to 600 Wh actually occurs. If the magnetic coupling device is required to be as small as possible and has a large amount of heat as described above, it will be very difficult to cool it down, and this will be a major obstacle to the practical use of the electromagnetic induction type charging system. ing.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a magnetic coupling device for an electric vehicle which can reduce the loss by increasing the degree of magnetic coupling between both primary and secondary coils as much as possible. Where you do it.

[0005]

The invention according to claim 1 is
For charging a power storage device of an electric vehicle with a charging power source, a primary unit having a primary coil is set on a secondary unit side having a secondary coil provided in the electric vehicle, and a primary coil is set. Is excited by a charging power supply to generate an electromotive force in the secondary coil to charge the power storage device. One of the primary and secondary coils is inserted into the other coil. It is characterized by being formed where possible.

According to a second aspect of the present invention, in the first aspect of the invention, the primary and secondary units each include a primary core and a secondary core which constitute a magnetic circuit when the primary unit is set in the secondary unit. A secondary core is provided, and these cores are characterized in that they are configured to penetrate both coils and draw a closed loop on one side of the coil to expose the other side of the coil. The invention of claim 3 is characterized in that, in the invention of claim 1 or 2, the primary coil is inserted into the secondary coil.

According to a fourth aspect of the present invention, in any one of the first to third aspects, at least one of the primary unit and the secondary unit is housed in a metal shield case, and the outer periphery of the coil is mounted on the shield case. The feature is that the surfaces are in contact.

[0008]

According to the first aspect of the present invention, since the primary and secondary coils are inserted into each other, most of the magnetic flux excited by one coil is linked to the other coil. become. As a result, the degree of magnetic coupling increases,
Loss is reduced.

According to the second aspect of the present invention, the core constituting the magnetic circuit penetrates both the primary and secondary coils inserted into each other and forms a closed loop on one side of the coil. Therefore, many portions of both coils are not buried in the core, but are exposed from the core. Therefore, Joule heat generated in the coil can be smoothly radiated to the outside, and it is possible to prevent the heat from being trapped and leading to a large temperature rise. In addition, the volume of the core can be reduced by such a magnetic circuit structure as compared with the related art, which contributes to reduction in size and weight.

According to the third aspect of the present invention, since the primary coil is inserted into the secondary coil, it is possible to reduce the size and weight of the primary unit, which is often held and operated by hand, and it is easy to use. improves.

According to the fourth aspect of the present invention, the heat generated in the coil is transmitted to the shield case and smoothly dissipated, so that not only is it effective in preventing a temperature rise but also in preventing radiation of noise. Contribute.

[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 this 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 body of an electric vehicle EV, and a charging connector 13 described later is inserted therein. You can set it.

As shown in FIG. 2, a secondary unit 20 is disposed behind the receiving portion 12 of the electric vehicle EV. The secondary unit 20 has a secondary core 21 and a secondary coil 22 made of, for example, ferrite, and is entirely housed in a shield case 23 made of, for example, an aluminum alloy. A lead wire 22A of the secondary coil 22 is connected to a power battery (not shown) which is a power storage device of the electric vehicle EV.
Is connected to a charging circuit for charging the battery, and rectifies the high-frequency electromotive force induced in the secondary coil 22 to charge the power battery. The secondary core 21 is made of, for example, ferrite, and as shown in FIG. 3, integrally has a rising wall 21B that rises vertically at the back of a flat bottom plate 21A. A circular base 21C is formed at the upper end to protrude forward. Guide grooves 21D are formed on both upper and lower end surfaces of the rising wall portion 21B. An engagement protrusion 23A projecting from the inner bottom surface of the shield case 23 is engaged with the lower guide groove 21D. Engagement projections 24A of a mounting member 24 screwed to the inner surface of the shield case 23 are engaged with the guide grooves 21D, and the secondary core 21 is thereby secured to the shield case 23.
Is mounted so as to be able to move within a predetermined stroke in the direction of going in and out. A leaf spring 25 is disposed between the back surface of the secondary core 21 and the back surface of the shield case 23, and constantly biases the secondary core 21 forward (to the right in FIG. 2). ing.

On the other hand, the secondary coil 22 is wound in a cylindrical shape having a relatively large inner diameter, and a bottom plate 21A of the secondary core 21 is provided.
And is arranged so as to be concentric with the circular base 21C. Therefore, in this state, the secondary coil 22 has an air-core shape that opens forward. As shown in FIG. 4, the shield case 23 is in contact with an area of about 3/4 of the outer peripheral surface of the secondary coil 22, so that Joule heat generated in the secondary coil 22 is shielded. 2
3 can be transmitted smoothly. The lead wire 22A of the secondary coil 22 penetrates through the back surface of the shield case 23 and is connected to a charging circuit (not shown) of the electric vehicle.

A lock ring 26 is attached to the front of the shield case 23. This is because a substantially semicircular locking ridge 26 is provided in front of the annular mounting base 26A.
B is provided integrally, and has a function of engaging a charging connector 13 described later.

As shown in FIG. 5, the charging connector 13 has a primary unit 30 disposed at the tip of a handle 14. The primary unit 30 is a primary core 31
The primary core 31 is also made of ferrite, and has a shape in which a cylindrical leg 31B is integrally protruded from the upper end of a flat plate-like vertical plate 31A as shown in FIG. The primary coil 32 is attached to the cylindrical leg 31B.
Is wound over substantially the entire area, and the outer periphery thereof and the vertical plate portion 31A of the primary core 31 are covered by a shield case 33 made of an aluminum alloy. The distal end surface of the shield case 33 has a cylindrical leg 3 of the primary core 31.
A circular opening 33A is formed at a position corresponding to 1B, and a rectangular opening 33B is formed at the lower end of the vertical plate portion 31A. A cover 34 for covering the circular opening 33A and the rectangular opening 33B is provided on the front surface of the shield case 33.
Is mounted so as to be openable and closable about a hinge shaft 35,
It is normally held in the closed position shown in FIG. 5 by a lock mechanism (not shown).

Further, as shown in FIG.
A lock member 36 is provided at a side portion of the handle 3 at a tip portion of the handle 14 so as to be rotatable about a shaft 37. The claw portion 36A is normally projected to the side of the charging connector 13 by a tension spring 38. It is energizing. Also,
The lock member 36 can be operated in a direction in which the claw portion 36A is retracted by a lock release button (not shown). The primary coil 32 is connected to a charging power supply 40 via a power cable 15 connected to the charging connector 13 (see FIG. 1).
Therefore, a high-frequency current can flow through the primary coil 32 to excite the primary coil 32.

The configuration of the present embodiment is as described above, and the operation will be described next. To charge the electric vehicle, the user holds the handle 14 of the charging connector 13 and
4 and open the leading primary unit 30 to the electric vehicle EV.
Into the secondary unit 20 of the above. Then, as shown in FIG. 7, the cylindrical leg 31B of the primary coil 32 and the primary core 31 is formed.
Are inserted into the secondary coil 22. In this state, the claw portion 36A of the lock member 36 of the charging connector 13 is engaged with the locking ridge 26B of the lock ring 26 of the secondary unit 20.
And is fixed in the set state shown in FIG. In this state, the circular base 21D of the secondary core 21 enters the circular opening 33A on the front surface of the primary unit 30 and abuts on the distal end surface of the cylindrical leg 31B of the primary core 31, and the bottom plate 21A of the secondary core 21 Is a rectangular opening 33 on the front of the primary unit 30.
B enters into B and is in contact with the lower end of the vertical plate portion 31A of the primary core 31, and these two cores 21 and 31 constitute a magnetic circuit penetrating the primary coil 22 and the secondary coil 32. The magnetic circuit is configured to penetrate both coils 22 and 32 and draw a closed loop on one side (below) of the coils 22 and 32.

Therefore, when the primary coil 22 is excited by the charging power supply device 40, the high-frequency magnetic flux excited by the primary coil 22 is linked to the secondary coil 32 to generate an electromotive force. The power storage device can be charged. After charging, the lock is released by operating the lock release button of the charging connector 13, the primary unit 30 is pulled out of the secondary unit 20, and the receiving unit 12 of the electric vehicle EV is received.
, And the cover 34 of the charging connector 13 may be closed.

According to the present embodiment, the following effects can be obtained. (1) When the primary unit 30 is inserted and set in the primary unit 20 of the electric vehicle EV, the primary coil 32 is inserted in the secondary coil 22 as shown in FIG. Therefore, most of the magnetic flux excited by the primary coil 32 is linked to the secondary coil 22, and the degree of magnetic coupling becomes extremely high. According to experiments, the loss can be reduced to about 1/10 compared to the conventional type,
Therefore, the amount of heat generated can be reduced to 1/10 and large power can be transmitted without taking special cooling means. This means that the power storage device of the electric vehicle EV can be charged in a short time and the charging connector 13 can be reduced in size, which is extremely convenient in practical use. (2) Moreover, in the present embodiment, both the primary and secondary cores 31 and 21 constitute a magnetic circuit that penetrates through the primary and secondary coils 22 and 32 and draws a closed loop. 32 has a closed shape on one side. Accordingly, the coils 22 and 32 are not buried in the core but are largely exposed. Therefore, Joule heat generated in the coils 22 and 32 can be smoothly radiated to the outside, and it is possible to prevent the heat from being trapped and leading to a large temperature rise. Further, the volume of the cores 21 and 31 can be reduced by such a magnetic circuit structure, which further contributes to reduction in size and weight. (3) In the present embodiment, the primary coil 32 is wound around the cylindrical leg 31B of the primary core 31 and inserted into the secondary coil 22 of the electric vehicle EV. The primary unit 30, which is often held and operated, can be reduced in size and weight, thereby improving usability. (4) In the present embodiment, the secondary core 21 is disposed so as to be movable with respect to the shield case 23 and
When the primary unit 30 is inserted, the cores 21 and 31 abut against each other to compress the leaf spring 25 while the primary unit 30 is inserted. 21 and 31 are brought into close contact with each other.
As a result, the leakage of magnetic flux at the joint between the cores 21 and 31 is reduced, and the degree of magnetic coupling can be maintained higher. (5) In the above embodiment, the circular base 21 is attached to the secondary core 21.
Since D is protruded, the circular base 21D enters the circular opening 33A on the front surface of the charging connector 13 and joins with the primary core 31. This means that on the primary unit 30 side, the distal end surface of the columnar leg 31B of the primary core 31 can be provided by retreating from the circular opening 33A to the inside, so that damage to the columnar leg 31B and adhesion of dirt can be prevented. It can be effectively prevented. (6) In the present embodiment, the shield cases 33 and 23 of the primary unit 30 and the secondary unit 20 are formed of an aluminum alloy having excellent thermal conductivity and conductivity, and the units 30 and 20 are accommodated therein. Because
The heat generated inside can be smoothly radiated to the outside and cooled, and noise radiation can be prevented. (7) Guide grooves 21D are formed above and below the primary core 21,
One (lower) guide groove 21 </ b> D has a shield case 23.
And the other (upper) guide groove 21 </ b> D is engaged with the engaging protrusion 24 </ b> A of the mounting member 24, which is a separate component, and the mounting member 24 is located inside the secondary coil 22. Since the screw is screwed at the position where the mounting is performed, a driver or the like can be inserted into the secondary coil 22 to easily fix the mounting member 24 to the shield case 23. Thus, while the secondary core 21 is configured to be movably mounted in the shield case 23, its assembly is extremely simple, and productivity can be improved. (8) In this embodiment, the secondary coil 32 on the electric vehicle side
Is set to have such a large inner diameter that the primary coil 22 can be inserted. Therefore, it is possible to easily remove dirt, foreign matter, and the like adhering to the inside of the secondary unit 30 and to have excellent maintainability.

<Second Embodiment> FIGS. 8 to 11 show a second embodiment of the present invention. Primary unit 5 is on the right side of FIG.
0 and the secondary unit 60 is shown on the left. The primary core 51 of the primary unit 50 is made of ferrite in which a yoke 51A and a cylindrical leg 51B are integrated, and a primary coil 52 is wound around the cylindrical leg 51B. The secondary core 61 of the secondary unit 60 is made of ferrite having a rising wall 61B protruding from one end of a bottom plate 61A, and the cylindrical leg 51B of the primary core 51 can be inserted into the rising wall 61 exactly. The receiving hole 61C is formed. The secondary coil 62 is an air-core cylindrical type and is arranged concentrically with the receiving hole 61C. The inner diameter of the secondary coil 62 is set slightly larger than the outer diameter of the primary coil 52, and the primary unit 50 is moved to the secondary unit 60 side as shown by the arrow in FIG. When inserted, the distal end of the cylindrical leg 51B of the primary core 51 enters the receiving hole 61C of the secondary core 61 as shown in FIG. 9 to form a closed-loop magnetic circuit, and the primary coil 52 The coil is completely inserted into the coil 62.

Therefore, also in this embodiment, the primary coil 5
The effect that most of the magnetic flux excited in 2 is linked to the secondary coil 62 and the degree of magnetic coupling is extremely high is obtained. Also in this embodiment, both coils 5
Since the cores 2 and 62 are not buried in the core but are largely exposed, the Joule heat generated in the coils 52 and 62 can be smoothly dissipated to the outside. Can be prevented beforehand. Also, the core 2 can be provided by such a magnetic circuit structure.
1, 31 can be reduced in volume, which further contributes to reduction in size and weight.

Moreover, in this embodiment, as shown in FIGS. 10 and 11, the primary unit 70 having a different capacity can be set in the secondary unit 60. That is, the primary unit 70 is the primary unit 50 described above.
"Means that the length of the cylindrical leg portion 71B of the primary core 71 is short and the primary coil 72 is small. Even if the primary coil 72 is small, there is no problem if the power transmission capacity is small. Also, even if the cylindrical leg 71B is short and the joint area with the secondary core 61 is small, the generated magnetic flux is small, so the problem is small. Absent. Rather, such a small primary unit 70
For example, the large primary unit 50 shown in FIG. 8 is used for quick charging at the charging stand, and the small primary unit 70 shown in FIG. 10 is used for long-time charging at home. Can be rationally handled.

In this embodiment, both cores 51, 6
The first bonding surface is formed along the insertion direction of the primary unit 50. This means that, in the butting type core, the error in the insertion depth appears as the size of the air gap between the cores and has a large effect on the magnitude of the magnetic resistance of the joint, whereas the error in the insertion depth does not affect both cores 51. , 61 means less influence on the magnetic resistance, and means that the magnetic resistance in the magnetic circuit is stable.

<Third Embodiment> FIGS. 12 and 13 show a third embodiment of the present invention. The primary core 81 of the primary unit 80 has an I-shape, and has an air-core primary coil 82 having a large diameter at one end thereof. On the other hand, the secondary unit 83
Has a square C shape having two legs 84A, and a secondary coil 85 is wound around one of the legs 84A.

When the primary unit 80 is moved and set in the direction of the arrow in FIG. 12, as shown in FIG. 13, the primary coil 82 and the secondary coil 85 are inserted and securely magnetically coupled. 81 and 84 form a closed loop magnetic circuit. With this configuration, the first
As in the embodiment, the effect is obtained that the degree of magnetic coupling between the two coils 82 and 85 is extremely high, and that the degree of exposure of the coils 82 and 85 is high and the cooling performance is excellent.

<Fourth Embodiment> FIG. 14 shows a fourth embodiment of the present invention. The structure of both primary and secondary coils is different from that of the third embodiment, and the structures of cores 81 and 83 are the same. is there. That is, both the primary coil 82 and the secondary coil 85 are air-core type, the primary coil 82 has an inside diameter that can be inserted into the leg 84A of the secondary core 84, and the secondary coil 85 has the primary coil 82 inside. It has an insertable inner diameter. When the primary unit 81 is moved as shown by the arrow in FIG.
The coupling state is the same as that shown in FIG.

<Fifth Embodiment> FIGS. 15 and 16 show a fifth embodiment of the present invention, which is different from the third embodiment shown in FIGS. In the configuration of the coils 82 and 85, the structures of both cores 81 and 84 are the same. That is, both legs 8 of the secondary core 84
A secondary coil 85 is wound around each of the coils 4 </ b> A. Cylindrical primary coils 82 having an inner diameter into which the secondary coil 85 can be inserted are located at both ends of the primary core 81. When this primary unit 80 is set as shown by the arrow in FIG.
As shown in FIG. 16, the coils 82 and 85 are in the inserted state,
In addition, the cores 81 and 84 form a closed-loop magnetic circuit. Thus, each coil is connected to two legs 84A.
In this case, the effect of reducing the size of each coil can be obtained. Note that, also in this embodiment, as shown in FIG.
May be inserted inside the.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing a charging system according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional side view of the secondary unit.

FIG. 3 is a perspective view showing primary and secondary cores.

FIG. 4 is a longitudinal sectional front view of the secondary unit.

FIG. 5 is a longitudinal sectional side view of the primary unit.

FIG. 6 is a partial cross-sectional view of the same primary unit.

FIG. 7 is a longitudinal sectional side view showing a state where the primary and secondary units are similarly combined.

FIG. 8 is a cross-sectional view of both units showing a second embodiment of the present invention.

FIG. 9 is a cross-sectional view showing the same coupling state.

FIG. 10 is a sectional view showing the same small primary unit.

FIG. 11 is a sectional view of the same small primary unit in a connected state;

FIG. 12 is a sectional view showing a third embodiment of the present invention.

FIG. 13 is a cross-sectional view showing the same coupling state.

FIG. 14 is a sectional view showing a fourth embodiment of the present invention.

FIG. 15 is a sectional view showing a fifth embodiment of the present invention.

FIG. 16 is a sectional view showing the same coupling state.

FIG. 17 is a sectional view showing a conventional structure.

[Explanation of symbols]

 EV ... electric vehicle 13 ... charging connector 20 ... primary unit 21 ... primary core 22 ... primary coil 23 ... shield case 30 ... secondary unit 31 ... secondary core 32 ... secondary coil 33 ... shield case 40 ... charging power supply

 ────────────────────────────────────────────────── ─── Continued from the front page (72) Inventor Toshiro Shimada 1-3-1 Shimaya, Konohana-ku, Osaka-shi, Osaka Sumitomo Electric Industries, Ltd.

Claims (4)

[Claims] 1. An electric vehicle for charging a power storage device of an electric vehicle by a charging power source, comprising: a primary unit having a primary coil; and a secondary unit having a secondary coil provided in the electric vehicle. In which the primary coil is excited by the charging power supply to generate an electromotive force in the secondary coil to charge the power storage device, wherein one of the primary and secondary is The coil of (1) is formed so as to be insertable inside the other coil, the magnetic coupling device for charging an electric vehicle. 2. The primary and secondary units are provided with a primary core and a secondary core which constitute a magnetic circuit when the primary unit is set in the secondary unit, and these cores penetrate both coils. 2. The magnetic coupling device for charging an electric vehicle according to claim 1, wherein the other side of the coil is exposed by drawing a closed loop on one side of the coil. 3. The magnetic coupling device for charging an electric vehicle according to claim 1, wherein the primary coil is inserted into the secondary coil. 4. The apparatus according to claim 1, wherein at least one of the primary unit and the secondary unit is housed in a metal shield case, and the outer peripheral surface of the coil is brought into contact with the shield case. A magnetic coupling device for charging an electric vehicle according to any one of the above.