JP7199170B2 - Contactless power supply device, coil, and method for manufacturing coil - Google Patents

Description

TECHNICAL FIELD The present invention relates to a contactless power supply device, a coil, and a method for manufacturing the coil.

In recent years, the adoption of contactless power supply in power supply systems for automatic guided vehicles and electric vehicles has been considered.

Wireless power supply technology consists of, for example, a planar coil (ground side coil) for power transmission (primary side) embedded in the road surface of a power supply station and a power receiving (secondary side) coil installed at the bottom of an electric vehicle. It is a technique for supplying electric power to an electric vehicle by wirelessly transmitting electric power while opposing a planar coil (vehicle-side coil) at a certain interval, for example, an interval of about several tens of centimeters.

In contactless power supply, high power transmission efficiency is required, and coils used for this are also required to have low loss. Therefore, coils used for contactless power supply need to reduce copper loss, that is, reduce AC resistance.

Planar coils used for contactless power supply in electric vehicles are being standardized for the drive frequency, minimum transmission efficiency including coil misalignment, and the allowable range for misalignment between the ground side coil and the vehicle side coil. Companies will compete to develop products with better performance.

When actually installing a coil in a power supply station or vehicle, the outer shape, inner diameter, and number of turns of the coil may also be specified. It is required to create a coil that also retains strength for retention.

The following two factors are conceivable as factors that affect the AC resistance of the coil. The first factor is the DC resistance, which depends on the conductor cross-sectional area of the winding wire, and the second factor is the loss due to the proximity effect and skin effect, which vary depending on the frequency, wire twist configuration, coil configuration, and the like.

In particular, since non-contact power supply is used in a high frequency band on the order of kHz, the influence of the second factor becomes large. In order to reduce the influence of the second factor, a litz wire is used as the wire material, and a coil that is wound with a gap between the windings (hereinafter referred to as a "gap wound coil") is suitable for the form of the coil. .

In view of the above circumstances, conventional coils used for contactless power supply are made by winding litz wires (insulated conductors), which are formed by twisting a plurality of thin enameled wires, in a planar spiral shape with gaps between the windings. to form.

By the way, providing a gap between the windings simply means that at the manufacturing site, the product as a coil is transported, the coil is transported during manufacturing, and it is necessary to suppress fluctuations in the inductance of the coil. , it is necessary to consider manufacturability in the process of winding the wire into a coil shape (ease of winding the wire with an automatic winding machine), shape retention and handling after that.

The conventional technique for providing gaps between windings is a "groove-fitting structure" in which a supporting substrate is prepared with spirally formed grooves with gaps, and wires are manually inserted into the grooves of the supporting substrate, or There is a technique such as a "spacer structure" in which a spacer is provided between windings to wind the windings (see, for example, Patent Document 1).

In the case of a coil with a "groove-fitting structure," the preparation of a supporting substrate increases the material cost of the supporting substrate, increases manufacturing costs, and increases the size of the coil unit, leading to an increase in transportation costs. There is In addition, since the coil of "spacer structure" also requires a space holding member called a spacer, there arises a problem that the member cost and manufacturing cost are increased in substantially the same manner as the "groove fitting structure".

JP-A-2008-60432

In the case of a conventional coil in which a current-carrying wire is wound in a plane as described above, in order to maintain the shape of the coil, a support substrate with grooves is prepared, or a spacer is inserted between the windings to maintain a gap during handling. In addition, there is a problem that parts such as spacers and substrates are costly, and the manufacturing efficiency is lowered due to the work.

Accordingly, the present invention has been made to solve the above-mentioned problems, and provides a coil-shaped coil that can obtain specified performance and is easy to handle without using an interval holding member such as a spacer or tape or a grooved support substrate. It is an object of the present invention to provide a contactless power supply device, a coil, and a method for manufacturing the coil.

In order to achieve the above object, a coil for contactless power supply according to one aspect of the present invention is a coil formed by winding an electric wire made of a litz wire a plurality of times, and from the start of winding, Nth, ( N + 1) and (N + 2) turns of the electric wire are both arranged in a curved shape with a first gap located between the turns of the electric wire (where N is an integer of 1 or more ), and on both sides of the corner section in the winding direction, every other wire (the N-th wire and the (N+2)-th wire) are placed in a constant second gap between the turns of the wire A first spaced section in which the (N + 1)th winding wire meanders in the second gap and is separated from the other parallel winding wires in the parallel section. and a straight section having first and second abutting sections that are arranged on both sides of the first spaced section and in which the (N+1)th turn of the wire contacts one of the parallel turns of the wire. In the entire corner section, the Nth, (N+1)th, and (N+2)th windings of the wire are separated from each other.

A contactless power supply device according to an aspect of the present invention includes a substrate made of metal or resin, a magnetic core plate arranged on the substrate, and the coil arranged on the magnetic core plate.

A method for manufacturing a coil for contactless power supply according to an aspect of the present invention is to form a coil having corner sections and straight sections on both sides of the corner sections in the winding direction by winding an electric wire made of litz wire a plurality of times. In the corner section, all the N-th, (N+1)-th, and (N+2)-th turns of the electric wire from the start of winding are placed in the first gap located between the turns of the electric wire and a step of arranging them in a curved shape by spacing them apart through the straight section, and a parallel section in which every other turn of the electric wire is routed in parallel with a certain second gap located between the turns of the electric wire in the straight section. arranging, and arranging in a straight section a first spaced section in which the (N+1)th turn wire meanders in the second gap and is separated from the other parallel turn wire in the parallel section. and arranging first and second abutting sections in which the (N+1)th turn of the electric wire abuts one of the parallel turns of the electric wire on both sides of the first spaced section in the straight section ; The corner section is characterized in that the Nth, (N+1)th, and (N+2)th turns of the wire are separated from each other in the entire corner section .

According to the present invention, it is possible to provide a non-contact power supply device, a coil, and a method for manufacturing the coil, which can be manufactured at a low cost while obtaining prescribed performance and with good manufacturing workability.

BRIEF DESCRIPTION OF THE DRAWINGS The top view of the spiral coil (square outline coil) of 1st Embodiment which concerns on this invention. FIG. 2 is an enlarged view showing a main part (corner section A1 and straight section A2) of the coil in FIG. 1; FIG. 2 is a diagram showing intervals (sections P3 and P4) of electric wires in the coil of FIG. 1; FIG. 4 is an enlarged view showing a straight line connecting the center positions of the radii R1 and R2 of the corner portions of the coil; The top view of the spiral-shaped coil (rectangular-shaped external coil) of 2nd Embodiment. FIG. 6 is an enlarged view showing a main part (corner section A1 and straight section A2) of the coil of FIG. 5; FIG. 6 is a frequency-AC resistance characteristic diagram comparing the coil of FIG. 5 and a comparative example; FIG. 2 is a cross-sectional view taken along the line BB in FIG. 1, showing the contactless power supply device using the coils of the first and second embodiments;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described based on the drawings.
A contactless power supply device is configured by arranging a contactless power transmission device on the primary side and a contactless power reception device on the secondary side facing each other. The contactless power transmitting device on the primary side, which supplies power, and the contactless power receiving device on the secondary side, which receives power, are composed of almost the same coil elements. side will be described, but it goes without saying that the other side is similar.

(First embodiment)
A coil 20 according to a first embodiment of the present invention will be described below with reference to FIGS. 1 and 2. FIG. FIG. 1 is a plan view of a spiral coil (corner meandering coil) according to the first embodiment of the present invention, and FIG. 2 is a main part (corner section A1, straight section A2, sections P1 to P4 of each part). is an enlarged view of.

As shown in FIGS. 1 and 2, a coil 20 according to the first embodiment of the present invention has a single electric wire or litz wire 22 as an insulated conductor wound in the winding direction C from the innermost position A0. First, the wires are spirally arranged flatly (in a plane) so as to provide a corner section A1 in which the electric wire is arranged in a curved manner and a straight section A2 in which the electric wire is arranged in a straight line every other turn. The (manufactured) coil has an approximately rectangular outer shape (the corner section A1 is rounded).

The straight section A2 is a parallel section in which odd-numbered electric wires n1, n3, n5, n7, and n9 are arranged in parallel at regular intervals every other turn, and even-numbered electric wires n2, n4, and n6. , n8 meander within the spacing, and are arranged to abut and separate parallel wires n1, n3, n5, n7 and n9.

In the straight section A2 (inside the parallel section), the even-numbered electric wires n2, n4, n6, and n8 are separated from the other parallel odd-numbered electric wires n1, n3, n5, n7, and n9 at the center. A section P3, which is the first spaced section, is arranged.
On both sides of the section P3, sections P1 and P2 are arranged in which the even-numbered electric wires n2, n4, n6, and n8 abut on any of the parallel odd-numbered electric wires n1, n3, n5, n7, and n9. It is A section P1 arranged on the left side of the section P3 is called a first contact section. A section arranged on the right side of the section P3 is called a second contact section P2.

The section P1 is a section in which the odd-numbered electric wire n1 and the even-numbered electric wire n2 on the outer peripheral side are in contact with each other, and the even-numbered electric wire n2 and the odd-numbered electric wire n3 on the outer peripheral side are separated from each other. .
Section P2 is a section in which the odd-numbered electric wire n1 and the even-numbered electric wire n2 on the outer peripheral side are separated from each other, and the even-numbered electric wire n2 and the odd-numbered electric wire n3 on the outer peripheral side are in contact with each other.

If the number of turns of the electric wire is replaced by N, and the Nth, (N+1), and (N+2) turns of the electric wire are set from the beginning of the winding, the section P1 is the Nth electric wire n1 and the (N+1)th turn of the electric wire. , and the (N+1)-th wire n2 and the (N+2)-th wire n3 are separated from each other. Note that N is an integer of 1 or more.
Section P2 is a section in which the N-th wire n1 and the (N+1)-th wire n2 are separated from each other, and the (N+1)-th wire n2 and the (N+2)-th wire n3 are in contact with each other. be.

In the corner section A1, electric wires n1, n2, n3, . That is, the Nth, (N+1)th, (N+2)th turns, and so on of the wires are arranged in a curved line with a space therebetween.

In the corner section A1, the radius R1 of the arc (curve) drawn by the odd-numbered wires n1, n3, n5, n7, and n9 and the radius of the arc (curve) drawn by the even-numbered wires n2, n4, n6, and n8 R2 is, for example, 40.0 mm (referred to as R40), and radii R1 and R2 are the same. Note that the radii R1 and R2 may differ from each other.

A section P4 is arranged in the corner section A1. A section P4 is formed from contact between the (N+1)-th wire (for example, the wire n2) and the N-th wire (for example, the wire n1) in the straight section A2 arranged before the winding direction. This is the second spaced section where the (N+1)-th wire (for example, the wire n2) and the (N+2)-th wire (for example, the wire n3) in the section P2 arranged ahead in the direction are brought into contact with each other.

In the corner section A1 of the coil 20 wound in this manner, the curved portions (arc portions) of the odd-numbered electric wires n1, n3, n5, n7, and n9 and the even-numbered electric wires n2, n4, n6, and n8 are radiused. Both R1 and R2 are wound with the same diameter, and adjacent electric wires (for example, electric wire n1 and electric wire n2, electric wire n2 and electric wire n3, etc.) are separated from each other, and straight sections A2 on both sides of the corner section A1 (front of the corner section A1) Since the electric wires are in contact with each other in the section P1 and the section P2) ahead of the corner section A1, it is called a "corner winding coil".

For winding the coil 20, an automatic winding device using a die (winding jig) having a spiral groove is used. The automatic winding device fixes the delivery position of the litz wire 22, applies the litz wire 22 to the groove of the winding jig, rotates the winding jig in a plane while feeding the litz wire 22, and rotates the litz wire to the groove. 22 in order.

Since the coil 20 which is simply wound in a spiral shape on a plane will come apart when it is removed from the mold (winding jig) or during transportation, it is fitted in the mold (winding jig) as shown in FIG. In this state, the adhesive is sprayed to bond the abutting portions of the windings together, and the windings are left for a certain period of time until the adhesive hardens, and then handled. For adhesion of the contact portion, for example, a litz wire 22 wound with heat-fusible fibers may be used for adhesion by heating. It may be welded or solvent-bonded, or an acetate thread may be wound around the litz wire 22 and solvent-bonded.

In other words, the coil 20 is formed by winding the litz wires 22 while arranging them substantially flat, and regularly providing spaced portions and contact portions between the wires to form a spiral shape as a whole. A pair of crimping terminals 21 and 24 are connected to both ends of a litz wire 22, which is bonded (fixed) with an adhesive. The crimp terminals 21 and 24 may be attached to both ends before or after bonding.

The litz wire 22 is a wire group formed by twisting and bundling a plurality of enameled wires. In this example, a litz wire 22 having a wire diameter of, for example, about 4.4 mm is used. As an electric wire for electricity other than this example, for example, a conductor without insulation coating (a wire made of copper or aluminum), a self-bonding wire having a self-bonding layer as the outermost layer, etc. may be used. .

The crimp terminal 21 is connected to one inner end of the litz wire 22, and generally includes a crimp portion and a fixing portion provided with a fixing hole. The crimping portion is composed of a cylindrical metal member, and the wire rod and the metal portion are crimped and integrated by inserting and crimping the conductor portion of the litz wire 22 from which the enamel coating has been removed, and the crimping terminal 21 is made into a litz wire. Secure to line 22 . The crimp terminal 24 is connected to one end of the outer side of the litz wire 22 and is the same as the crimp terminal 21 .

As shown in FIG. 2, the coil 20 is wound so as to provide four wire wiring sections P1 to P4 (hereinafter referred to as "sections P1 to P4") P1 to P4 in one winding. A section P2, a section P3, and a section P1 are arranged in the straight section A2, and a section P4 is arranged in the corner section A1. Sections P1 to P4 are arranged so as to repeat the order of section P2, section P3, section P1, and section P4 in the direction in which the wire is wound from the straight section A2 to the corner section A1.

Section P1 (first contact section) is the N-th wire from the start of winding (wire n1 in the case of the first wire from the inside) and the (N+1)-th wire (the second wire from the inside). In the case of the contact part where the electric wire n2) abuts, the (N+1)th winding wire (second winding wire n2 from the inside) and the (N+2)th winding wire (in the case of the third winding from the inside is a section having a spaced portion where the electric wire n3) is spaced apart. Note that N is an integer of 1 or more.

In the section P2 (second contact section), the electric wire n1 that is the N-th winding wire and the electric wire n2 that is the (N+1)-th winding wire are separated from each other, and the electric wire that is the (N+1)-th winding wire is separated. It is a section having a portion where n2 and the electric wire n3, which is the (N+2)th turn electric wire, abut against each other.

In the section P3 (first spaced section), the electric wire n2, which is the (N+1)th winding wire, is in contact with the electric wire n3, which is the (N+2)th winding wire, and the electric wire n1, which is the Nth winding wire. This is the section where the contact is switched to contact.

In other words, in this section P3 (first spaced section), the electric wires n2, n4, . from the abutment portion of the wire to the abutment portion of the wires n1, n3, .

In the section P4 (second spaced section), the electric wire n2, which is the (N+1)-th turn wire in the straight section A2 arranged on the front side in the winding direction, extends from the contact with the electric wire n1 to the tip of the winding direction. This is a section that switches to abutment with the electric wire n3, which is the (N+2)-th turn electric wire in the section P2 of the straight section A2 arranged at .

In other words, in the section P4 (fourth section), the electric wires n2, n4, . From the contact portion of certain electric wires n1, n3, n5, . . . to the contact portion of the electric wires n3, n5, . It is a section (to cross).

In the section P4, from the section P1 on the right side of the section P4 to the section P2 on the left side of the section P4, the even-numbered electric wire n2 (the 2N-th electric wire ) is wound. That is, in this section P4, the even-numbered electric wire n2 is arranged so as to obliquely cross the gap between the odd-numbered electric wires n1 and n3.

In other words, in the section P4, the even-numbered electric wires n2, n4, . are arranged to traverse a curve of radius R2 having a center position different from the center position of . Note that the center position of the radius includes a center point that draws the radius and a line that connects the center points.

As shown in FIG. 2, the even-numbered wires n2 of the section P4 are connected to the first contact portion 31 of the first section P1 adjacent to one side (right side) of the section P4 and the other side (lower left side) of the section P4. side) and the second contact portion 32 of the section P1 adjacent thereto.

For example, the winding structure of the coil 20 will be described using electric wires n1, n2, and n3 as an example. In the sections P1 and P2, the even-numbered electric wire n2 is made to meander between the parallel odd-numbered electric wires n1 and n3 to contact and separate them.

Also, in the sections P3 and P4, the even-numbered wire n2 is diagonally crossed so as to switch the contact/separation relationship of the wires n1, n2, and n3.

In this way, the electric wires with different windings are separated by the section P3 of the straight section A2 and the section P4 of the corner section A1, and in the sections P1 and P2 between them, the adjacent electric wires are brought into contact with each other at a substantially constant interval. By bonding the contact portion, the shape retention force of the coil can be improved.

In this example, the total number of turns of the coil is 9, but the present invention can be applied to other numbers of turns and winding methods. In this example, the total number of turns is an odd number, but it may be an even number, and the number of turns itself may be increased or decreased.

In this example, the litz wire 22 is spirally wound so as to have a rectangular outer shape (when the outer shape is substantially rectangular as in this example, the four corner sections A1 are rounded). In addition, the outer shape may be polygonal such as substantially triangular, substantially pentagonal, substantially hexagonal, substantially octagonal, substantially D-shaped, substantially rectangular, and the like.

A method of manufacturing the coil 20 shown in FIG. 1 will be described below.
In this case, the coil 20 is formed by winding the litz wire 22 a plurality of times from the inner circumference to the outer circumference, with the innermost circumference as the first turn. At this time, while winding the litz wire 22, the wiring state of the sections P1 to P4 is formed. In this embodiment, the winding of the electric wire is started from the innermost peripheral side, but the winding may be started from the outermost peripheral side.

In this case, when the litz wire 22 is wound along the winding direction C from the position A0, the litz wire 22 is wound in the first turn (the first winding wire n1) except for the corner section A1. Roll straight without bending.

In the second turn, the wire n2 of the second winding contacts the wire n1 of the first winding and immediately enters the corner section A1, so the wire n2 is separated (branched) from the wire n1 in the corner section A1. and wire in a curved shape with a radius of R2.

In the section P2 of the straight section A2 beyond the corner section A1, the electric wire n2 is wired so as to abut on the electric wire n3 to be wound in the next turn.

In the section P3 of the straight section A2, the electric wire n2 is bent away from the contact position with the electric wire n3, and is wound obliquely toward the electric wire n1.

Then, in the section P1, the electric wire n2 abuts on the electric wire n1 and is wound along the electric wire n1.

Before entering the straight section A2, the electric wire n2 is separated from the electric wire n1 and wound to draw an arc with a radius R2 toward the electric wire n3. In this way, the electric wire n2 is meandered for the remaining half turn to complete the second turn.

Next, for the third turn (the electric wire n3 of the third turn), the litz wire 22 is wound linearly without bending along the same trajectory as the first turn (the electric wire n1 of the first turn). As a result, the electric wire n3 of the third roll contacts the electric wire n2 of the second roll in the section P2.

In this way, the electric wires for each turn are arranged in a curved line with a space therebetween in the corner section A1. The wires n7 and n9 are arranged parallel to each other at regular intervals, and the even-numbered wires n2, n4, n6 and n8 are arranged within the intervals of the odd-numbered wires n1, n3, n5, n7 and n9. meanders, and are arranged so as to be in contact with and separated from parallel wirings n1, n3, n5, n7, and n9.

As described above, according to the contactless power supply device of the first embodiment, the corner section A1 in which the electric wires of each turn are spaced apart and curved in a curved shape, and the electric wires n1 and n3 of the odd-numbered turns from the inner circumference side are arranged. are wound in parallel, and the even-numbered electric wires n2, n4, . As shown in , the spiral coil is provided with sections (section P3 in the center of the straight section A2 and section P4 in the corner section A1) for switching to the other winding wire at substantially constant intervals, and these sections P3, By forming contact parts with other windings on both sides of P4 and bonding the contact parts, the shape retention force of the coil is improved, and it is possible to connect between wires without providing spacers or support substrates. To provide a contactless power supply device, a coil, and a method for manufacturing a coil, which can handle a coil with regular gaps, and which is low in cost and has good coil manufacturing workability while obtaining specified performance. can do.

In the above embodiment, the radii R1 and R2 are the same and the center positions are different. However, as shown in FIG. so that the position and the position of the straight line connecting the center positions of the radii R2 of the electric wires n2, n4, . A winding wire may be arranged. It is conceivable to set the mutual radii R1 and R2 to, for example, 40.0 mm (R40). By setting the radii R1 and R2 to be the same diameter in this manner, the effect of facilitating automatic winding of the electric wire by an automatic winding machine is obtained.

(Second embodiment)
Next, a second embodiment will be described with reference to FIGS. 5 and 6. FIG. FIG. 6 is a plan view showing the coil of the second embodiment (a pair of rectangular coils with two wires), and FIG. 7 is an enlarged view of the essential part thereof. In the second embodiment, the same components as in the first embodiment are assigned the same reference numerals, and the description thereof will be omitted.

As shown in FIG. 5, the coil 20 of the second embodiment has a corner section A1 and straight sections A2 on both sides of the corner section A1. be. The coil 20 is formed by winding a pair of litz wires 22a and 22b consisting of an inner wire 22a and an outer wire 22b so as to have a substantially rectangular outer shape (with rounded corner sections A1). The electric wire itself is of a parallel type in which two wires having the same diameter as in the first embodiment are used in a pair.

For example, if two wires each having a diameter of 4.4 mm are used, the cross-sectional area of the two wires is approximately 16.0 mm ² , which is twice the conductor cross-sectional area of one litz wire 22. , DC resistance is halved, and loss and heat generation can be suppressed. It also contributes to making the magnetic field distribution of the coil more uniform.

In the second embodiment, the sections P1, P2, and P3 are arranged in the straight section A2, and the section P4 is arranged in the corner section A1. ing.

More specifically, as shown in FIG. 6, the corner section A1 consists of the (N+1)th turn wire n5 and the (Nth ) between the (N+1)-th electric wire n5 and the (N+2)-th electric wire n6 in the section P2 arranged ahead of the section A1 in the winding direction C from the contact with the electric wire n4 of the winding. It has a section P4, which is a second spaced section that switches to abutment.

In this corner section A1, the radius R1 of the arc (curve) drawn by the electric wire 22b on the outer peripheral side, such as the wire n4 of the Nth turn and the wire n6 of the (N+2)th turn, is, for example, 72.4 mm (hereinafter R72.4 ). On the other hand, the radius R2 of the arc (curve) drawn by the (N+1)-th wire n5 (inner wire 22a) is, for example, 68.0 mm (R68.0), and the radii R1 and R2 are different. .

By setting the outer wire 22b and the inner wire 22a of the pair of two electric wires 22a and 22b to have different radii, the distance of the straight section is increased, and the contact portion is increased, so that the coil shape retention force can be further improved. In terms of the relationship between adjacent electric wires on the inner peripheral side and the outer peripheral side, the radius R1 of the electric wire 22b positioned on the outer peripheral side is set larger than the radius R2 of the electric wire 22a positioned on the inner peripheral side. R2 (inner circumference side) < R1 (outer circumference side)

The straight section A2 has a parallel section in which every other wire (for example, the N-th wire n4 and the (N+2)-th wire n6) are wired in parallel at regular intervals. Three sections (sections P1, P2, P3) are provided in this parallel section, and the sections P2, P3, P1, . . . are arranged in the winding direction C in this order.

The section P3 is arranged in the central part of the parallel section, and the (N+1)-th wire n5 meanders diagonally within the interval to form another parallel wire (the wire n4 or the wire n6). ) is a first spaced interval.

A section P1 and a section P2 are arranged on both sides of the section P3. These sections P1 and P2 are contact sections in which the (N+1)-th wire n5 abuts on either of the adjacent parallel wire wires n4 and n6. A section P1 arranged on the left side of the section P3 is called a first contact section. A section arranged on the right side of the section P3 is called a second contact section P2.

Section P1 is a section in which the N-th wire n4 and the (N+1)-th wire n5 are in contact with each other, and the (N+1)-th wire n5 and the (N+2)-th wire n6 are separated from each other. is.

Section P2 is a section in which the N-th winding wire n4 and the (N+1)-th winding wire n5 are separated from each other, and the (N+1)-th winding wire n5 and the (N+2)-th winding wire n6 are in contact with each other. be.

In this coil 20, the electric wire n5 is wired so as to obliquely cross parallel electric wires (for example, between the electric wires n4 and n6) in the substantially central section P3 and the corner section A1 (section P4) of the straight section A2. .

Next, a method for manufacturing the coil 20 of the second embodiment will be described.
In the second embodiment, the innermost circumference is the first turn, and the inner circumference side litz wire 22a is wound multiple times from the inner circumference side toward the outer circumference side, and then the inner circumference side litz wire 22a is wound. Then, the litz wire 22b on the outer peripheral side is wound a plurality of times from the inner peripheral side to the outer peripheral side to form a corner section A1 as shown in FIG. 5 and straight sections A2 on both sides of the corner section A1 in the winding direction C. A coil 20 is formed. In this example, the winding is started from the innermost circumference side, but the winding may be started from the outermost circumference side.

At this time, as shown in FIG. 6, in the corner section A1 (section P4), for example, each turn (N-th, (N+1)-th, (N+2)-th turn) of the electric wire n4, the electric wire n5, the electric wire n6, etc. are spaced apart and arranged in a curved line.

Subsequently, in the straight section A2, a parallel section is arranged in which alternate turns of electric wires (the N-th electric wire n4 and the (N+2)-th electric wire n6) are wired in parallel at regular intervals.

A section P3 in which the (N+1)th turn wire n5 meanders within the interval between the wire n4 and the wire n6 and is separated from the other parallel turn wire at the center in the parallel section is arranged in the straight section A2.

Also, in the straight section A2, on both sides of the section P3, sections P1 and P2 are arranged in which the (N+1)th winding wire n5 abuts on either of the parallel winding wires n4 and n6.

As described above, according to the second embodiment, the inner litz wire 22a and the outer litz wire 22b, which are adjacent to each other due to winding, abut each other in the central section P3 of the straight section A2 and the section P4 of the corner section A1. In particular, contact sections (sections P1 and P2) where wires with different turns contact each other are arranged on both sides of a corner portion A1 where the wires are separated from each other, and the wires of each turn of the coil 20 are bonded together. By arranging the contact portions (contact portions) evenly in the radial direction from the center of the coil 20 and bonding the contact portions, it is possible to increase the shape retention force of the coil with gaps.

Here, referring to FIG. 7, the coil 20 of the second embodiment (corner meandering coil in FIG. 5) and the comparative example (a coil in which a litz wire is spirally wound with a gap of a constant interval (hereinafter referred to as This will be referred to as a "gap wound coil"), and the performance will be explained.

A gap-wound coil is a coil in which a litz wire is spirally wound with a constant gap. A gap-wound coil is a standard coil as a sample in which a predetermined gap is provided between each turn of the litz wire.

As test conditions, for each of the above two samples (gap wound coil and corner winding coil), both ends of the coil were connected to an existing LCR meter, and the AC resistance was measured by changing the frequency from 0 to 200 kHz. is. In FIG. 7, the value at the position where the frequency is 0 (about 14 mΩ) is the DC resistance.

Referring to FIG. 7 showing the measurement results, it can be seen that the meandering corner winding coil of the present invention has characteristics similar to those of the gap winding coil at any frequency, and the specified performance is obtained.

The non-contact power feeding device using the coil 20 (corner meandering coil) shown in the first and second embodiments includes a substrate 1 such as an aluminum plate and a substrate 1 arranged on the upper surface of the substrate 1, as shown in FIG. and a coil 20 placed (arranged) on the upper surface of the core plate 2 .

As a result, for example, the contactless power transmission device on the primary side or the contactless power receiving device on the secondary side can be used. Furthermore, in order to fix the position of the coil 20 on the magnetic core plate 2, the upper surface of the magnetic core plate 2 may be coated with mold resin or the like. Further, a groove for holding the shape of the coil 20 may be provided in the magnetic core plate 2 itself. The substrate 1 may be a metal plate such as an aluminum plate, or may be an insulating plate such as a resin plate.

When the coil 20 is moved onto the magnetic core plate 2 in this way, by bonding the abutting portions of the wires in advance, the need for a support substrate (bobbin) with grooves, a spacer, or the like is eliminated. The coil 20 can be handled in a state in which the shape is maintained without any defects, the inductance fluctuates less, and good handling properties (workability during coil manufacturing) can be obtained.

Although the embodiment of the present invention has been described above, the above embodiment is presented as an example and is not intended to limit the scope of the invention. The novel embodiments described above can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. The above-described embodiments and their modifications are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and equivalents thereof.

REFERENCE SIGNS LIST 1 aluminum plate (substrate) 2 magnetic core plate 20 coil 21, 24 crimp terminal 22, 22a, 22b litz wire.

Claims (7)

A coil for contactless power supply formed by winding an electric wire made of a litz wire a plurality of times,
All of the N-th, (N+1)-th, and (N+2)-th turns of the electric wire from the start of winding are arranged in a curved shape with a first gap located between the turns of the electric wire. a corner section (where N is an integer equal to or greater than 1);
On both sides of the corner section in the winding direction, the N-th turn of the electric wire and the (N+2)-th turn of the electric wire are arranged in parallel with a constant second gap between the turns of the electric wire. A first spaced section in which the (N+1)th turn wire meanders in the second gap and is separated from the other parallel turn wire in the parallel section , a straight section having first and second abutting sections arranged on both sides of the first spaced section, in which the (N+1)th winding of the electric wire abuts against one of the parallel windings of the electric wire. have
The coil, wherein the Nth, (N+1)th, and (N+2)th turns of the electric wire are separated from each other in the entire corner section . The corner section is
From the abutment of the (N+1)-th wire and the N-th wire in the straight section placed before in the winding direction, the straight line in the straight section placed ahead in the winding direction 2. The coil according to claim 1, further comprising a second spaced section in which the (N+1)-th wire and the (N+2)-th wire are brought into contact with each other. The radius or the center position of the radius of the arc (curve) drawn by the N-th wire and the (N+2)-th wire in the corner section, and the arc (curve) drawn by the (N+1)-th wire ) is different from the radius or the center position of the radius. 2. The coil according to claim 1, wherein a pair of wires comprising an inner wire and an outer wire are wound. 5. The coil according to any one of claims 1 to 4, wherein the portions where the electric wires contact each other are adhered. a substrate made of metal or resin;
a magnetic core plate disposed on the substrate;
A contactless power supply device comprising the coil according to any one of claims 1 to 5 arranged on the magnetic core plate. A coil manufacturing method for forming a coil for contactless power supply having a corner section and straight sections on both sides of the corner section in the winding direction by winding an electric wire made of a litz wire multiple times,
In the corner section, all of the Nth, (N+1)th, and (N+2)th turns of the electric wire from the start of winding are separated through a first gap located between the turns of the electric wire to form a curved shape. placing in
In the straight section, the N-th winding wire and the (N+2)-th winding wire are wired in parallel with a constant second gap between the windings of the electric wire. arranging the section;
A step of arranging a first spaced section in which the (N+1)th turn wire meanders in the second gap and is separated from other parallel turn wires in the parallel section in the straight section;
arranging first and second abutting sections in which the (N+1)th winding of the electric wire abuts one of the parallel windings of the electric wire on both sides of the first spaced section in the straight section. death,
A method of manufacturing a coil, wherein the corner sections are formed such that the Nth, (N+1)th, and (N+2)th turns of the electric wire are separated from each other .

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