JP7574562B2 - Coil manufacturing method - Google Patents

Description

The present invention relates to the technical field of a coil manufacturing method, and more particularly, to a coil manufacturing method for contactless power transmission.

In recent years, electric vehicles equipped with storage batteries such as lithium-ion batteries are becoming more common. In such electric vehicles, the motor is driven by the power stored in the storage battery to move, so efficient charging of the storage battery is required. Therefore, as a method for charging the storage battery mounted on an electric vehicle without physically connecting a charging plug or the like to the electric vehicle, research has been conducted on so-called wireless power transmission, which uses a receiving coil and a transmitting coil that are separated and opposed from each other. Wireless power transmission methods generally include an electric field coupling method, an electromagnetic induction method, and a magnetic field resonance method. When these methods are compared from the viewpoints of, for example, the frequency of the power transmitted and received, the degree of freedom in the horizontal and vertical directions, and the transmission efficiency, the electric field coupling method using a capacitor or the magnetic field resonance method using a coil is considered to be promising as a wireless power transmission method for charging the storage battery mounted on an electric vehicle, and research and development into these methods is also being actively conducted. For example, the following Patent Document 1 can be cited as a prior art document disclosing such background technology. This patent document 1 discloses a coil that transmits power by magnetic resonance using a loop coil with one winding (1 turn) and an open coil with 5.5 windings (5.5 turns).

On the other hand, the frequency of the power transmitted and received by the wireless power transmission is predetermined for each device that carries it, for example by law, and in the case of power transmission to the electric vehicle, it is set to a high frequency of 85 kHz. It is generally known that when a high-frequency current flows through a conductor, the current density is high on the surface of the conductor and decreases from the surface toward the center. In addition, as the frequency of the current increases, the current is concentrated on the surface, and as a result, the AC resistance of the conductor increases. This phenomenon is known as the "skin effect of the conductor." In the following explanation, the AC resistance of a conductor when a high-frequency current flows through the conductor is simply referred to as "impedance."

On the other hand, the above-mentioned wireless power transmission (contactless power supply) for electric vehicles requires the transmission (i.e., flowing through the coil) of a high-output power of at least 3.7 kilowatts while using a high-frequency (e.g., the above-mentioned 85 kilohertz) current. Therefore, if the resistance of the conductor (coil) increases due to the above-mentioned skin effect as a result of passing such high-output power (current), the generation of Joule heat will increase the loss in the coil, reducing the efficiency of wireless power transmission.

Another electrical phenomenon that reduces the efficiency of wireless power transmission, similar to the skin effect, is the so-called "conductor proximity effect," which occurs when conductors are wound in close proximity to each other as they are wound into a coil. Therefore, measures must be taken to prevent the increase in impedance caused by this proximity effect.

As a method for reducing impedance due to heat generation caused by losses in the coil, it is considered to construct the coil itself using twisted wire (so-called Litz wire). However, when considering that the receiving coil will be installed in a private vehicle, constructing the coil using the twisted wire leads to an increase in the weight and price of the coil. A conventional technique for solving this problem is to use a core material made of, for example, thin copper films and insulating layers that insulate the thin films, which is patterned and etched into the shape of the coil using a so-called photolithography method, and then stacking multiple layers of the etched core material and electrically connecting the layers to produce a stacked coil.

JP 2011-200045 A

However, the manufacturing method using the photolithography method described above has the problem that, for example, all of the copper thin film other than the coil pattern is removed in a non-reusable state, which increases the material and process costs for the coil, resulting in high overall costs.

The present invention has been made in consideration of the above problems and demands, and one example of an object of the present invention is to provide a manufacturing method for a coil that can reduce various costs as a coil for wireless power transmission.

In order to solve the above problem, the invention described in claim 1 provides a manufacturing method for a coil for contactless power transmission , which is formed by winding a winding line consisting of a plurality of straight portions made of a thin film conductor and a plurality of curved portions made of a thin film conductor , the method including: a partial winding manufacturing process for manufacturing a plurality of partial winding lines made of the thin film conductor that are connected in the winding direction of the coil to form the winding line , each partial winding line consisting of one of the straight portions and one of the curved portions continuing from the one of the straight portions; and a winding manufacturing process for arranging each of the manufactured partial winding lines in the winding direction and electrically connecting them to manufacture the winding line , wherein each of the curved portions is a curved portion for bending the winding line to form the winding, each of the partial winding lines has the same width, and the partial winding lines that are connected at different positions in the winding to form the winding line have the same shape.

According to the invention described in claim 1, for partial winding lines each consisting of one straight portion and one curved portion, a plurality of the partial winding lines that are connected at different positions to form the winding line have the same shape, each curved portion is a curved portion for bending the winding line to form a coil winding, and each partial winding line has the same width , so that by sharing the partial winding lines at a plurality of positions in the winding line, the number of types of partial winding lines when manufacturing one coil can be reduced, and the material costs and manufacturing costs of the coil can be reduced. Also, because each partial winding line consists of one straight portion and one curved portion, sharing of the partial winding lines is further promoted, and the associated costs can be further reduced.

In order to solve the above problem, the invention described in claim 2 is a coil manufacturing method described in claim 1, in which the same shape is configured to be a shape that is symmetrical when viewed from the center of the winding.

According to the invention recited in claim 2, in addition to the effects of the invention recited in claim 1, a winding is manufactured by connecting a plurality of partial windings having a symmetrical shape when viewed from the center of the winding of the winding at different positions, so that by increasing the number of partial windings that are shared, further cost reduction is possible.

To solve the above problem, the invention described in claim 3 is a coil manufacturing method described in claim 1 or claim 2, in which the partially wound wire manufacturing process is configured to manufacture each of the partially wound wires using at least one of a casting method or a die-cutting method using a mold having a shape corresponding to the same shape.

According to the invention described in claim 3, in addition to the effects of the invention described in claim 1 or claim 2, each partial winding is manufactured using at least one of a casting method and a die-cutting method using a mold with a shape corresponding to the shape of each of the identical partial windings. This makes it possible to reduce costs compared to manufacturing the entire coil using a photolithography method in which a conductor thin film of a size corresponding to the size of the coil is etched, and also contributes to the reuse of thin-film conductor materials.

In order to solve the above problem, the invention described in claim 4 is a coil manufacturing method described in any one of claims 1 to 3 , further comprising a lamination process of stacking the winding wire manufactured in the winding wire manufacturing process with an insulating layer sandwiched between them.

According to the invention described in claim 4 , in addition to the effect of the invention described in any one of claims 1 to 3 , since the windings are stacked with an insulating layer sandwiched therebetween, a coil having a stacked winding configuration can be manufactured at low cost.

In order to solve the above problems, the invention described in claim 5 provides a coil manufacturing method described in claim 4 , wherein the stacking process includes an insertion process of inserting a conductor post into a hole for conductive connection formed in each of the windings after stacking the windings, and a conduction process of deforming the inserted conductor post to conductively connect each of the windings.

According to the invention recited in claim 5 , in addition to the effect of the invention recited in claim 4 , after stacking the winding wires, a conductor post is inserted into the hole for conductive connection and the conductor post is deformed to conductively connect the winding wires, so that the stacked winding wires can be reliably conductively connected.

According to the present invention, for partial windings each consisting of one straight portion and one curved portion, a plurality of the partial windings which are connected at different positions to form a winding have the same shape, each curved portion is a curved portion for bending the winding to form a coil, and each partial winding is configured to have the same width .

Therefore, by sharing partial windings at multiple locations of the winding, the number of types of partial windings when manufacturing one coil can be reduced, and the material costs and manufacturing costs of the coil can be reduced. Also, since each partial winding consists of one straight portion and one curved portion, the sharing of partial windings can be further promoted, and the associated costs can be further reduced.

1 is a block diagram showing a schematic configuration of a power transmission system according to a first embodiment; FIG. 2 is a plan view showing a structure of a receiving coil according to the first embodiment. FIG. 11 is a plan view (i) showing the shapes of members constituting the power receiving coil of the first embodiment. FIG. 2B is a plan view showing the shapes of members constituting the power receiving coil of the first embodiment; FIG. 2 is an external perspective view conceptually illustrating a connection state of members in the power receiving coil of the first embodiment. 4 is a flowchart showing a manufacturing process of the power receiving coil and the power transmitting coil according to the first embodiment. 1A and 1B are diagrams illustrating a manufacturing method used in the manufacturing process of the receiving coil and transmitting coil of the first embodiment, in which (a) is a conceptual diagram illustrating a die-cutting method, and (b) is a diagram illustrating a manufacturing method of a stacked receiving coil. FIG. 11 is a plan view (i) showing the structure of a receiving coil according to a second embodiment. FIG. 11 is a plan view (ii) showing the structure of a receiving coil according to a second embodiment. FIG. 11 is a plan view (iii) showing the structure of the receiving coil of the second embodiment. 11A and 11B are diagrams (I) showing an aspect of interlayer connection in a receiving coil of a second embodiment, where (a) is a plan view showing said aspect, and (b) is an external perspective view (i) showing said aspect. 13A and 13B are diagrams (II) showing an aspect of interlayer connection in a receiving coil of a second embodiment, where (a) is an external oblique view (ii) showing said aspect, and (b) is an external see-through view showing said aspect. 10 is a flowchart showing a manufacturing process of the receiver coil according to the second embodiment. 11A and 11B are cross-sectional views showing a first method of interlayer connection in the manufacturing process of a receiving coil of the second embodiment, where (a) is a cross-sectional view showing a first step of the first method, (b) is a cross-sectional view showing a second step of the first method, (c) is a cross-sectional view showing a third step of the first method, (d) is a cross-sectional view showing a fourth step of the first method, (e) is a cross-sectional view showing a fifth step of the first method, (f) is a cross-sectional view showing a sixth step of the first method, and (g) is a cross-sectional view showing a seventh step of the first method. 11A and 11B are cross-sectional views showing a second method of interlayer connection in the manufacturing process of the receiving coil of the second embodiment, where (a) is a cross-sectional view showing a first step of the second method, (b) is a cross-sectional view showing a second step of the second method, (c) is a cross-sectional view showing a third step of the second method, and (d) is an oblique view conceptually showing the state of interlayer connection by the second method.

Next, the embodiments for carrying out the present invention will be described with reference to the drawings. Note that the embodiments and modifications described below are embodiments and modifications in which the present invention is applied to a power transmission system that transmits power for charging a rechargeable battery mounted on an electric vehicle to the electric vehicle equipped with the rechargeable battery in a non-contact manner using magnetic resonance.

Here, the magnetic field resonance type power transmission system of each embodiment and modified form includes a power transmission coil (described below) that transmits power, and a power receiving coil (described below) that is disposed facing (i.e., opposite) the power transmission coil at a distance from the power transmission coil and receives the power transmitted from the power transmission coil.

(A) First embodiment
First, a first embodiment of the present invention will be described with reference to FIGS.

(I) Overall Configuration and Operation of the Power Transmission System of the First Embodiment
First, the overall configuration and operation of the power transmission system of the first embodiment will be described with reference to Fig. 1. Fig. 1 is a block diagram showing a schematic configuration of the power transmission system of the first embodiment.

As shown in FIG. 1, the power transmission system S1 of the first embodiment is composed of a power receiving device R1 having a power receiving unit RV and the power receiving coil RC1, and a power transmitting device T1 having a power transmitting unit TR and the power transmitting coil TC1. At this time, the power receiving device R1 is mounted on the electric vehicle and is connected to a storage battery (not shown) mounted on the electric vehicle. On the other hand, the power transmitting device T1 is installed on the ground at a position where the electric vehicle moves or stops. When charging the storage battery, the electric vehicle is driven or stopped so that the power receiving coil RC1 of the power receiving device R1 and the power transmitting coil TC1 of the power transmitting device T1 face each other. Note that, when charging the storage battery by the power transmission system S1 of the first embodiment, it can be configured to transmit power from the power transmitting device T1 to the power receiving device R1 mounted on the stopped electric vehicle via the power transmitting coil TC1 of the power transmitting device T1 installed on the ground below the stopping position. Alternatively, the power transmission device T1 may be configured to continuously transmit power to a power receiving device R1 mounted on a moving electric vehicle via the power transmission coils TC1 of multiple power transmission devices T1 installed in a section of a certain distance on the road on which the electric vehicle is traveling. In this case, the power transmission unit TR corresponds to an example of the "output means" of the present invention, and the power receiving unit RV corresponds to an example of the "input means" of the present invention.

As shown in FIG. 1, the power transmission coil TC1 is composed of a power transmission loop coil, described later, wound concentrically or approximately concentrically. The power receiving coil RC1 is composed of a power receiving loop coil, described later, wound concentrically or approximately concentrically. The power to be transmitted to the power receiving device R1 is input from the power transmission unit TR to the power transmission loop coil of the power transmission coil TC1. As a result, the power transmission coil TC1 transmits the power to the power receiving coil RC1 by the magnetic field resonance method. On the other hand, the power receiving loop coil of the power receiving coil RC1 is disposed so as to face the power transmission coil TC1, and outputs the power received from the power transmission coil TC1 by the magnetic field resonance method to the power receiving unit RV. In this case, the power transmission coil TC1 and the power receiving coil RC1 each correspond to an example of a "coil" in the present invention.

In the above configuration, the power transmission unit TR of the power transmission device T1 outputs the power to be transmitted to the power receiving device R1 to the power transmission coil TC1 while complying with laws and regulations such as the Radio Act in the country in which the power transmission system S1 is used. The laws and regulations to be complied with at this time regulate the leakage magnetic field to be below a predetermined level, for example, taking into account the effects on the human body. In addition, in order to enable interconnection between all the power transmission devices T1 and the power receiving device R1, it is necessary for both to use a predetermined range of frequencies, and therefore the predetermined range of frequencies or frequency bands must comply with the recommendations of international organizations such as ISO (International Organization for Standardization) or IEC (International Electrotechnical Commission) as the laws and regulations. The power transmission coil TC1 then transmits the output power to the power receiving coil RC1 by magnetic resonance. In addition, the lower limit of the transmission efficiency, which takes into account a certain positional misalignment between the power transmission coil TC1 and the power receiving coil RC1, is also specified by the international organization, so the power transmission system S1 is also required to have high power transmission efficiency.

The receiving loop coil constituting the receiving coil RC1 of the power receiving device R1, which receives the power from the power transmitting coil TC1 by the magnetic field resonance method, outputs the received power to the power receiving unit RV. As a result, the power receiving unit RV converts the output corresponding to the power (for example, the high-frequency power of 85 kHz) into a DC (direct current) current, for example, by a power conversion unit (not shown), and outputs it to the storage battery of the electric vehicle. With the above configuration of the power receiving device R1, the storage battery is charged with the required amount of power.

(II) Configuration of receiving coil RC1 (transmitting coil TC1)
Next, the configuration of the power transmission coil TC1 and the power receiving coil RC1 of the first embodiment used in the power transmission system S1 of the first embodiment described above will be described with reference to Figs. 2 to 5. The power transmission coil TC1 and the power receiving coil RC1 of the first embodiment basically have the same configuration. Therefore, in the following description, the structure of the power receiving coil RC1 will be described. Also, Fig. 2 is a plan view showing the structure of the power receiving coil RC1 of the first embodiment, and is a plan view of the power receiving coil RC1 viewed from the power transmitting device T1 side in the power receiving device R1 (see Fig. 1). Furthermore, Figs. 3 and 4 are plan views showing the shapes of the members constituting the power receiving coil RC1, respectively, and Fig. 5 is an external perspective view conceptually showing the connection state of the members in the power receiving coil RC1.

As shown in the plan view of FIG. 2, the power receiving coil RC1 of the first embodiment is configured by laminating the power receiving loop coil RL1, which is made of, for example, thin copper wire and wound six times (6 turns) counterclockwise from the external connection terminal O1 at the outermost periphery to the external connection terminal O2 at the innermost periphery, on an insulating film BF. Here, in the first embodiment, the film BF is used to laminate the power receiving loop coil RL1, but other insulating materials such as glass epoxy materials can also be used. In addition, in order to efficiently dissipate heat generated by the power receiving coil RC1, a thin film material in which, for example, ceramic particles are dispersed can also be used. Furthermore, the centers of winding of the power receiving loop coil RL1 are the same or approximately the same for each winding.

On the other hand, as shown in FIG. 2, the receiving coil RC1 is configured by winding the receiving loop coil RL1 in the same layer within the receiving coil RC1, and the outermost and innermost ends (the center of the right side in FIG. 2) are the external connection terminals O1 and O2 for connecting the receiving loop coil RL1 to the receiving unit RV, respectively. As shown in FIG. 2, the receiving loop coil RL1 is configured by connecting the straight line members RL101 to RL125 from the external connection terminal O1 to the external connection terminal O2 with the curved member CN1, which is bent at a right angle, sandwiched between them. As a result, the receiving loop coil RL1 is generally rectangular. In this case, the receiving loop coil RL1 corresponds to an example of the "winding line" of the present invention. Also, each of the straight line members RL101 to RL125 and the curved member CN1 corresponds to an example of the "partial winding line" of the present invention.

On the other hand, as shown by solid lines in Fig. 3, each of the straight members RL101 to RL125 has a trapezoidal shape with the same width and thickness but different lengths in the winding direction. In contrast, each of the curved members CN1 has the same shape and width and thickness as the straight members RL101 to RL125 as shown by solid lines in Fig. 4. As shown in Fig. 5 for a part of the upper left corner of the power receiving loop coil RL1 in Figs. 2 to 4, each of the straight members RL101 to RL125 and the corresponding curved member CN1 are connected by welding, for example, so that their ends overlap. By connecting the straight members RL101 to RL125 and the corresponding curved members CN1, a six-turn power receiving loop coil RL1 is formed.

(III) Manufacturing method of the receiving coil RC1 and the transmitting coil TC1
Next, an outline of a manufacturing method for the power receiving coil RC1 and the power transmitting coil TC1 of the first embodiment will be described with reference to Fig. 6 and Fig. 7. Fig. 6 is a flow chart showing the manufacturing process for the power receiving coil RC1 and the power transmitting coil section TC1, and Fig. 7 is a diagram explaining a manufacturing method used in the manufacturing process for the power receiving coil RC1 and the power transmitting coil TC1. Here, the manufacturing method for the power receiving coil RC1 and the manufacturing method for the power transmitting coil TC1 are basically the same, so the manufacturing method for the power receiving coil RC1 will be described below.

As shown in FIG. 6, the manufacturing method is as follows: first, straight members RL101 to RL125 (including external connection terminals O1 and O2) are manufactured by, for example, a die-cutting method or casting method using dies having shapes corresponding to the straight members RL101 to RL125 (step S1). Next, each curved member CN1 is manufactured by, for example, a die-cutting method or casting method using dies having shapes corresponding to the curved members CN1 (step S2).

Here, as the punching method used in steps S1 and S2, for example, as shown by the white arrow in Fig. 7(a), a method is used in which a thin film material MT made of, for example, copper, wound in a roll shape is pulled out and punched using a punching die having a shape corresponding to each of the straight members RL101 to RL125 or the curved member CN1. In Fig. 7, the shape of the punching die DE used when manufacturing the loop coil L is shown in a generalized form. According to the punching method shown in Fig. 7, the thin film material MT is pulled out as shown by the hatched arrow in Fig. 7(b) and punched using the punching die DE, thereby continuously manufacturing loop coils L of the same shape as shown by the white arrow in Fig. 7(b). That is, for the straight members RL101 to RL125 that differ only in length, punching dies having shapes corresponding to the respective shapes are used to manufacture the straight members RL101 to RL125 (step S1). On the other hand, for curved members CN1 that have the same shape, all curved members CN1 are manufactured continuously using a single die that has a corresponding shape (step S2).

After the straight members RL101 to RL125 and the curved member CN1 are manufactured by the above steps S1 and S2, the manufactured straight members RL101 to RL125 and the curved member CN1 are then arranged in their respective positions as the receiving loop coil RL1 shown in Figures 2 to 4 (step S3), and the corresponding members are connected to each other by a method such as welding to manufacture the receiving loop coil RL1 (see Figure 5, step S4).

As shown in generalized form as loop coil L and film BF in Figures 7(c) and 7(d), the power receiving loop coil RL1 manufactured in steps S1 to S4 is laminated on film BF, for example, by an adhesive method, to complete the power receiving coil RC1 (step S5). After that, the external connection terminals O1 and O2 are connected to the power receiving section RV (in the case of power receiving device R1) or the power transmitting section TR (in the case of power transmitting device T1), completing the power receiving device R1 or power transmitting device T1.

As described above, according to the structure of the receiving coil RC1 and the manufacturing method thereof of the first embodiment, the multiple curved members CN1 that are connected at different positions to form the receiving loop coil RL1 have the same shape. Therefore, by sharing the curved members CN1 at multiple locations in the receiving loop coil RL1, the number of types of members required to manufacture one receiving coil RC1 can be reduced, and the material costs and manufacturing costs for the receiving coil RC1 can be reduced.

In addition, the receiving loop coil RL1 is manufactured by connecting multiple straight members RL101 to RL125 and curved member CN1, which have symmetrical shapes when viewed from the center of the windings of the receiving loop coil RL1, so by increasing the number of common members, further cost reductions are possible.

Furthermore, when manufacturing the straight members RL101, etc. using at least one of a casting method and a die-cutting method using molds with shapes corresponding to the individual shapes of the straight members RL101 to RL125 and the curved member CN1 (see Figures 6 and 7), it is possible to reduce each cost and also contribute to the reuse of the thin film material MT, compared to manufacturing the entire receiving coil RC1 using, for example, a photolithography method in which a conductive thin film of a size corresponding to the size of the receiving coil RC1 is used.

Furthermore, since the receiving coil RC1 is composed of straight members RL101 to RL125 and a curved member CN1, and the shape of each member includes straight or curved portions as the receiving loop coil RL1, the components constituting the receiving loop coil RL1 are more commonly used, which further reduces the associated costs.

In addition, since the receiving loop coil RL1 is laminated on the insulating film BF, the receiving coil RC1 having a laminated structure can be manufactured at low cost. The above-mentioned series of effects can also be obtained by manufacturing a transmitting coil TC1 having the same structure.

(B) Second embodiment
Next, a second embodiment of the present invention will be described with reference to Fig. 8 to Fig. 15. Fig. 8 to Fig. 10 are plan views showing the structure of a receiving coil according to the second embodiment, and Fig. 11 and Fig. 12 are views showing the manner of interlayer connection in the receiving coil. Fig. 13 is a flow chart showing a manufacturing process of the receiving coil, Fig. 14 is a cross-sectional view showing a first method of interlayer connection in the manufacturing process of the receiving coil, and Fig. 15 is a cross-sectional view showing a second method of interlayer connection.

In the above-described first embodiment of the receiving coil RC1 and transmitting coil TC1, a single receiving loop coil RL1 consisting of straight members RL101 to RL125 and curved member CN1 is wound six times (6 turns) on the film BF. In contrast, the receiving coil and transmitting coil of the second embodiment described below have a structure in which two windings are stacked with an insulating film sandwiched between them.

(I) Configuration of the power receiving coil of the second embodiment (power transmitting coil of the second embodiment)
First, the configuration of the receiving coil of the second embodiment and the transmitting coil of the second embodiment used in the power transmission system of the second embodiment will be described with reference to FIG. 8 to FIG. 12. The power transmission system of the second embodiment is similar to the power transmission system S1 of the first embodiment in that the power transmission system of the second embodiment is composed of a power receiving device including a receiving coil and a power receiving unit, and a power transmitting device including a power transmitting coil and a power transmitting unit. The configuration of the receiving coil of the second embodiment and the configuration of the transmitting coil of the second embodiment are basically the same except for their sizes. Therefore, in the following description, only the configuration and the manufacturing method of the receiving coil of the second embodiment will be described. At this time, the same component numbers are given to the components of the power transmission system of the second embodiment that are the same as those of the power transmission system S1 of the first embodiment, and detailed description will be omitted. Also, FIG. 8 to FIG. 10 are plan views of the receiving coil of the second embodiment when viewed from the power transmitting device of the second embodiment, for example, in the power receiving device of the second embodiment.

That is, as shown in the plan view of Fig. 8, the power receiving coil RC2 of the second embodiment is configured by stacking a power receiving loop coil RL2 made up of two parallel wires, for example, copper thin film wire RL21 and copper thin film wire RL22 (the configurations of each will be described in detail later), and a power receiving loop coil RL3 not shown in Fig. 8 , in the direction of the paper surface of Fig. 8 via a film BF similar to that of the power receiving coil RC1 of the first embodiment. The power receiving loop coil RL3 is also configured of two parallel wires, for example, copper thin film wire RL31 and copper thin film wire RL32 (the configurations of each will be described in detail later). Furthermore, the winding center of the copper thin film wire RL21 and copper thin film wire RL22 that make up the power receiving loop coil RL2 and the winding center of the copper thin film wire RL31 and copper thin film wire RL32 that make up the power receiving loop coil RL3 are mutually identical.

As shown in FIG. 8, the receiving loop coil RL2 is composed of copper thin film wire RL21 and copper thin film wire RL22 wound in parallel to each other in the same layer of the receiving coil RC2. The copper thin film wire RL21 and copper thin film wire RL22 are connected at their respective ends at the center of one side (the right side in FIG. 8) of the outer periphery of the receiving loop coil RL2, and have external connection terminals O21 and O22 for connecting the receiving loop coil RL2 to a power receiving unit (not shown) of the second embodiment. On the other hand, the receiving loop coil RL2 is composed of the copper thin film wire RL21 and the copper thin film wire RL22 wound in parallel counterclockwise from the external connection terminal O21 three times (three turns) toward the center of the receiving coil RC1, and then wound another three times (three turns) from the center toward the outer periphery, and the outermost periphery is the other external connection terminal O22.

8, the copper thin-film wire RL21 is configured by arranging the thin-film wire members RL2101 to RL2125, including straight and curved portions, in the winding direction of the copper thin-film wire RL21 with gaps between them from the external connection terminal O21 to the external connection terminal O22. At this time, the thin-film wire members RL2101 to RL2125 constituting the copper thin-film wire RL21 have the same width and thickness. Furthermore, adjacent ones of the thin-film wire members RL2101 to RL2125 are each electrically connected to the thin-film wire members constituting the copper thin-film wire RL31 via interlayer connections as described below, and as a result, the copper thin-film wire RL21 is electrically connected from the external connection terminal O21 to the external connection terminal O22. On the other hand, as shown in FIG. 8, the copper thin film wire RL22 is also configured by arranging the thin film wire members RL2201 to RL2225 including straight and curved portions in the winding direction of the copper thin film wire RL22 with gaps between them from the external connection terminal O21 to the external connection terminal O22. At this time, the thin film wire members RL2201 to RL2225 constituting the copper thin film wire RL22 have the same width and thickness as each other and the same width and thickness as the thin film wire members RL2101 to RL2125. Furthermore, adjacent ones of the thin film wire members RL2201 to RL2225 are each electrically connected to the thin film wire members constituting the copper thin film wire RL32 via interlayer connections as described later, and as a result, the copper thin film wire RL22 is electrically connected from the external connection terminal O21 to the external connection terminal O22. As a result, the copper thin film wire RL2 is generally formed in a substantially square shape.

The intersections of the copper thin film wire RL21 and the copper thin film wire RL22 in the windings are mutually insulated and intersect at four points (see FIG. 8) by a laminated structure in which the wires are electrically connected with an insulating layer (not shown) sandwiched therebetween. Furthermore, the thin film wire members RL2101 to RL2125 include a plurality of types of wires having the same shape. For example, the thin film wire members RL2102 and RL2103 shown in FIG. 8 have the same shape. Similarly, the thin film wire members RL2201 to RL2225 include a plurality of types of wires having the same shape. For example, the thin film wire members RL2202 and RL2203 shown in FIG. 8 have the same shape.

Next, the configuration of the power receiving loop coil RL3, which is layered directly below the power receiving loop coil RL2 via the film BF, will be described with reference to FIG. 9. Note that FIG. 9 is a plan view showing only the power receiving loop coil RL3.

The power receiving loop coil RL3, which constitutes the power receiving coil RC2 of the second embodiment together with the power receiving loop coil RL2 shown in Fig. 8, basically has the same configuration as the power receiving loop coil RL2. That is, as shown in Fig. 9, the power receiving loop coil RL3 is composed of a copper thin film wire RL31 and a copper thin film wire RL32 wound in parallel with each other in the same layer of the power receiving coil RC2 (i.e., the layer directly below the power receiving loop coil RL2 sandwiching the film BF in Fig. 8). The copper thin film wire RL31 and the copper thin film wire RL32 are connected at their respective ends to the center of one side of the outer periphery of the power receiving loop coil RL3 (the right side in the case shown in Fig. 9), and the power receiving loop coil RL3 is connected to the power receiving unit not shown and has external connection terminals O31 and O32 that are the same shape as the external connection terminals O21 and O22 of the power receiving loop coil RL2. On the other hand, the receiving loop coil RL3 is constructed by winding the thin copper wire RL31 and the thin copper wire RL32 counterclockwise in parallel from the external connection terminal O31 toward the center of the receiving coil RC2 three times (three turns), and then winding another three times (three turns) from the center toward the outer periphery, the outermost periphery of which is the other external connection terminal O32.

9, the copper thin-film wire RL31 is configured by arranging the thin-film wire members RL3101 to RL3125, including straight and curved portions, in the winding direction of the copper thin-film wire RL31 with gaps between them from the external connection terminal O31 to the external connection terminal O32. At this time, the thin-film wire members RL3101 to RL3125 constituting the copper thin-film wire RL31 have the same width and thickness. Furthermore, adjacent ones of the thin-film wire members RL3101 to RL3125 are each electrically connected to the thin-film wire members RL2101 and the like constituting the copper thin-film wire RL21, as described later, via interlayer connections, and as a result, the copper thin-film wire RL31 is electrically connected from the external connection terminal O31 to the external connection terminal O32. 9, the copper thin-film wire RL32 is also configured by arranging thin-film wire members RL3201 to RL3225 including straight and curved portions in the winding direction of the copper thin-film wire RL32 with gaps between them from the external connection terminal O31 to the external connection terminal O32. At this time, the thin-film wire members RL3201 to RL3225 constituting the copper thin-film wire RL32 have the same width and thickness as each other and as the thin-film wire members RL3101 to RL3125. Furthermore, adjacent ones of the thin-film wire members RL3201 to RL3225 are electrically connected to each other via interlayer connections with the thin-film wire members RL2201 and the like constituting the copper thin-film wire RL22, as described later, and as a result, the copper thin-film wire RL32 is electrically connected from the external connection terminal O31 to the external connection terminal O32. As a result, the copper thin-film wire RL3 has an overall roughly square shape.

The intersections of the copper thin film wire RL31 and the copper thin film wire RL32 in the windings are mutually insulated and intersect at four points (see FIG. 9) by a laminated structure in which the wires are electrically connected with an insulating layer (not shown) sandwiched therebetween. Furthermore, the thin film wire members RL3101 to RL3125 include a plurality of types of wires having the same shape. For example, the thin film wire members RL3102 and RL3103 shown in FIG. 9 have the same shape. Similarly, the thin film wire members RL3201 to RL3225 include a plurality of types of wires having the same shape. For example, the thin film wire members RL3202 and RL3203 shown in FIG. 9 have the same shape.

Furthermore, between the thin film wire members RL2101 to RL2125 that form the copper thin film wire RL21 and the thin film wire members RL3101 to RL3125 that form the copper thin film wire RL31, there are multiple types of members that have the same shape. For example, the thin film wire member RL2102 shown in FIG. 8 and the thin film wire member RL3102 shown in FIG. 9 are identical in shape, although the arrangement directions of the copper thin film wire RL21 and the copper thin film wire RL31 are different. Similarly, the thin film wire member RL2103 shown in FIG. 8 and the thin film wire member RL3103 shown in FIG. 9 are identical in shape.

Next, the positional relationship between the power receiving loop coil RL2 (i.e., copper thin film wire RL21 and copper thin film wire RL22) and the power receiving loop coil RL3 (i.e., copper thin film wire RL31 and copper thin film wire RL32) will be described with reference to FIG. 10. FIG. 10 is a plan view showing the overlapping state of the power receiving loop coil RL2 and the power receiving loop coil RL3, with the power receiving loop coil RL2 (copper thin film wire RL21 and copper thin film wire RL22) shown by a solid line and the power receiving loop coil RL3 (copper thin film wire RL31 and copper thin film wire RL32) layered directly below it with film BF (not shown in FIG. 10) in between, shown by a dashed line.

As shown by solid lines in Fig. 10, the receiving loop coil RL2 is made of copper thin-film wire RL21 consisting of thin-film wire members RL2101 to RL2125 and copper thin-film wire RL22 consisting of thin-film wire members RL2201 to RL2225, and is wound three times counterclockwise from the outermost external connection terminal O21 toward the inner circumference, and then wound three times in the same counterclockwise direction from the innermost to the outermost external connection terminal O22. The copper thin-film wire RL21 and the copper thin-film wire RL22 are wound in parallel with each straight line and curved line so that the position of the straight line shifts in the radial direction of the receiving coil RC1 by one pitch in the winding of the copper thin-film wire for each turn. Here, the "pitch" refers to the radial distance between the centers of the sides in the winding of the receiving loop coil RL2 in the radial direction (hereinafter the same). On the other hand, as shown by the dashed lines in FIG. 10, the power receiving loop coil RL3 is made of a copper thin film wire RL31 consisting of thin film wire members RL3101 to RL3125 and a copper thin film wire RL32 consisting of thin film wire members RL3201 to RL3225, and is wound three times counterclockwise from the outermost external connection terminal O31 toward the inner circumference, and then wound three times in the same counterclockwise direction from the innermost to the outermost external connection terminal O32. As with the power receiving loop coil RL2, the straight and curved parts are formed so that the position of the straight part shifts in the radial direction by one pitch in the winding of the copper thin film wire with each turn, and the copper thin film wire RL31 and the copper thin film wire RL32 are wound in parallel.

10, when viewed from the center of the windings of the power receiving loop coil RL2 and the power receiving loop coil RL3, the copper thin film wire RL21 and the copper thin film wire RL22 of the power receiving loop coil RL2 are stacked so that they are in the same position as the copper thin film wire RL31 and the copper thin film wire RL32 of the power receiving loop coil RL3. That is, in the power receiving coil RC2 in which the power receiving loop coil RL2 and the power receiving loop coil RL3 are stacked, the power receiving loop coil RL2 (i.e., the copper thin film wire RL21 and the copper thin film wire RL22) and the power receiving loop coil RL3 (i.e., the copper thin film wire RL31 and the copper thin film wire RL32) are stacked so that the copper thin film wire RL21 and the copper thin film wire RL22 and the copper thin film wire RL31 and the copper thin film wire RL32 overlap at that position, respectively. The power receiving loop coil RL2 and the power receiving loop coil RL3 are connected to each other at their four corners via a film BF (not shown in FIG. 10).

Next, the interlayer connection between the power receiving loop coil RL2 and the power receiving loop coil RL3 will be described with reference to Figs. 11 and 12. Figs. 11 and 12 are external perspective views conceptually showing the interlayer connection at the lower left corner in Figs. 8 to 10. More specifically, Fig. 11(a) is a plan view showing the interlayer connection at the lower left corner, and Figs. 11(b) and 12 are external perspective views showing the interlayer connection at the lower left corner.

11 and 12, there is the gap GP between the thin film wire member RL2104 arranged, for example, at the outermost periphery of the power receiving loop coil RL2 and the thin film wire member RL2103 of the power receiving loop coil RL2 arranged adjacent to the thin film wire member RL2104. Similarly, there is the gap GP between the thin film wire member RL3104 arranged, for example, at the outermost periphery of the power receiving loop coil RL3 and the thin film wire member RL3103 of the power receiving loop coil RL3 arranged adjacent to the thin film wire member RL3104. Meanwhile, there is an overlap between the thin film wire member RL2104 and the thin film wire member 3103 at their respective curved portions. In the overlapping portion, the thin film wire member RL2014 and the thin film wire member RL3103 are electrically connected via vias V (eight vias V in the example shown in Figs. 11 and 12) that penetrate the film BF, which is omitted from Figs. 11 and 12. On the other hand, the thin film wire member RL2104 is electrically connected via another via V to the thin film wire member RL3104 that is disposed adjacent to the thin film wire member RL3103 across the gap GP in the power receiving loop coil RL3. The thin film wire member RL3103 is further electrically connected via another via V to the thin film wire member RL2103 that is disposed adjacent to the thin film wire member RL2104 across the gap GP in the power receiving loop coil RL2. Due to the above-mentioned structure of the power receiving loop coil RL2 and the power receiving loop coil RL3, the thin film wire members RL2103 and RL2104 of the power receiving loop coil RL2 and the thin film wire members RL3103 and RL3104 of the power receiving loop coil RL3 are all electrically connected. That is, the power receiving loop coil RL2 and the power receiving loop coil RL3 are electrically connected to each other for each winding of the copper thin film wire RL21 and the copper thin film wire RL22, and the copper thin film wire RL31 and the copper thin film wire RL32.

(II) Manufacturing method of the receiving coil RC2
Next, an outline of a method for manufacturing the receiving coil RC2 of the second embodiment will be described with reference to Fig. 13 to Fig. 15. Note that the method for manufacturing the transmitting coil of the second embodiment is basically the same as the method for manufacturing the receiving coil RC2 described below.

As shown in FIG. 13, the manufacturing method involves first manufacturing the thin-film wire members RL2101 to RL2125 and the thin-film wire members RL2201 to RL2225, as well as the thin-film wire members RL3101 to RL3125 and the thin-film wire members RL3201 to RL3225 (including the external connection terminals O21 and O22, and the external connection terminals O31 and O32) by, for example, a die-cutting method or a casting method using a mold similar to that of the first embodiment (step S10; see FIGS. 6 and 7).

Next, the manufactured thin-film wire members RL2101, etc. are placed at the respective positions on the film BF as the receiving loop coil RL2 and the receiving loop coil RL3 shown in Figures 8 and 9 (step S11), and the above-mentioned vias V are formed to connect the necessary thin-film wire members to each other (i.e., electrically connect them), thereby manufacturing the receiving coil RC2 (step S12).

Here, we will explain the first method of interlayer connection in step S12 above using Figure 14 and the second method using Figure 15.

(i) First method of interlayer connection
First, the first method of the interlayer connection will be described. In the first method, as a first step, as shown in Fig. 14(a), patterned copper thin films 100 that will become the thin film wire members RL2101 and the like are attached to both sides of the film BF. Next, as a second step, as shown in Fig. 14(b), holes H1 are opened at the positions of the copper thin films 100 that will become the vias V, and then, as a third step, as shown in Fig. 14(c), plating 101 is formed on the entire surface including the holes H1 by, for example, electroless plating. In this case, the thickness of the plating 101 is preferably, for example, about 0.3 micrometers.

Next, as the fourth step, the resist 102 is patterned as shown in FIG. 14(d), and then as the fifth step, as shown in FIG. 14(e), the plating 103 is further formed by, for example, electrolytic plating. In this case, the thickness of the plating 103 is preferably, for example, about 25 micrometers. Next, as the sixth step, the resist 102 is peeled off as shown in FIG. 14(f), and finally, as the seventh step, the plating 101 is removed by, for example, etching as shown in FIG. 14(g). At this time, since the plating 103 is sufficiently thick compared to the plating 101, even if the etching is to the extent that the plating 101 is removed, the plating 103 is not entirely etched away. By the first method including the above seven steps, the receiving coil RC2 including the receiving loop coil RL2 and the receiving loop coil RL3 (including the via V) is manufactured as shown in the partial cross-sectional view in FIG. 14(g).

(ii) Second method of interlayer connection
Next, the second method of interlayer connection will be described. The second method is based on the premise that holes H2 for forming the vias V are pre-opened at positions where the vias V of the thin film wire members RL2101 to RL2125, the thin film wire members RL2201 to RL2225, the thin film wire members RL3101 to RL3125, the thin film wire members RL3201 to RL3225, and the film BF are to be connected. The holes H2 can also be used as positioning holes when arranging the thin film wire members RL2101, etc. on both sides of the film BF.

In the second method, as shown in FIG. 15(a), the patterned copper thin film 100 that will become the thin film wire member RL2101 and the like is attached to both sides of the film BF using the hole H2 as a clue for positioning. Next, as shown in FIG. 15(b), as the second step, a columnar copper material 200 that will become the via V is inserted into the hole H2 and is pressed and deformed from both sides of the film BF as shown by the white arrow in FIG. 15(b). Finally, as shown in FIG. 15(c), as the third step, the copper material 200 is deformed until it fills the inner surface of the hole H2, thereby forming the above-mentioned via V for interlayer connection between the power receiving loop coil RL2 and the power receiving loop coil RL3 sandwiched between the film BF, as shown in FIG. 15(d). By the second method including the above three steps, the power receiving coil RC2 including the power receiving loop coil RL2 and the power receiving loop coil RL3 connected by the via V is manufactured. Then, the external connection terminals O21 and O22, and the external connection terminals O31 and O32 are connected to the power receiving unit of the second embodiment (in the case of the power receiving device of the second embodiment) or the power transmitting unit of the second embodiment (in the case of the power transmitting device of the second embodiment), completing the power receiving device of the second embodiment or the power transmitting device of the second embodiment.

As described above, according to the structure of the receiving coil RC2 and the manufacturing method thereof of the second embodiment, in addition to the effects of the structures of the receiving coil RC1 and the transmitting coil TC1 of the first embodiment and the manufacturing method thereof, since the receiving coil RC2 is made of the thin-film wire member RL2010, etc., it is possible to further promote standardization of the thin-film wire members RL2101, etc. that constitute the receiving loop coil RL2 and the receiving loop coil RL3, thereby further reducing the associated costs.

In addition, since the receiving loop coil RL2 and the receiving loop coil RL3 are laminated on the insulating film BF, the receiving coil RC2 having a laminated structure can be manufactured at low cost.

Furthermore, since the receiving loop coil RL2 and the receiving loop coil RL3 are formed by connecting multiple thin-film wire members RL2101 etc. in the winding direction, the receiving coil RC2 can be manufactured at low cost.

Furthermore, the ends of the thin-film wire members RL2104, etc. that form the power receiving loop coil RL2 and the ends of the thin-film wire members RL3103, etc. that form the power receiving loop coil RL3, which are stacked via the film BF, overlap when viewed in plan of the power receiving coil RC2, and vias V are provided to connect the overlapping ends between layers (see Figures 11 and 12), so that the power receiving loop coil RL2 and the power receiving loop coil RL3 can be reliably connected while reducing the costs of the power receiving coil RC2. As a result, the interlayer connection is made at the corner of the power receiving coil RC2, so that the impedance does not increase due to the interlayer connection.

Furthermore, according to the second method of interlayer connection in the power receiving coil RC2 shown in FIG. 15, a columnar copper material 200 is inserted into the hole H2 for interlayer connection, and the copper material 200 is deformed to form a via V for interlayer connection, thereby ensuring interlayer connection between the stacked power receiving loop coils RL2 and RL3.

In addition, according to the second method, the positioning holes H2 for interlayer connection are pre-drilled in the portions of the thin-film wire members RL2101 etc. where the interlayer connection is to be made, so that the positioning accuracy of the interlayer connection can be improved while ensuring a conductive connection between the thin-film wire members RL2101 etc.

The above-mentioned series of effects can also be obtained by manufacturing the second embodiment of the transmission coil having the same structure.

Variations

Next, modified forms of the present invention will be described. The configuration of the power transmission system of each of the above-described embodiments may be modified as shown in (A) to (D) below. Even when each of these modifications is made, the present invention can achieve the same effects as the above-described power transmission system.

(A) First modified form
First, as a first modified embodiment, the number of turns in the power receiving coil RC1 or the power transmitting coil in each embodiment may be changed to a different number of turns.

(B) Second Modified Form
Next, as a second modified embodiment, the order of the power receiving loop coil RL2 and the power receiving loop coil RL3 of the second embodiment when viewed from the power receiving unit RV (or the power transmitting unit TR) side of the second embodiment may be interchanged.

(C) Third Modification
Next, as a third variant, in the receiving coil RC2 of the second embodiment (or the transmitting coil of the second embodiment), the winding direction of the receiving loop coil RL2 (receiving loop coil RL3) may be configured to be placed at the innermost circumference and then folded back in the opposite direction (i.e., wound counterclockwise from the outermost circumference to the innermost circumference, and then wound clockwise from the innermost circumference to the outermost circumference).

(D) Fourth Modification
Finally, as a fourth modified embodiment, the copper thin-film wires RL21 and the like in each embodiment have the same width over the entire circumference, but may be configured to be wider from the outer circumference to the inner circumference.

As explained above, the present invention can be used in the field of contactless power transmission, and particularly when applied to the field of power transmission for charging storage batteries installed in electric vehicles, it can produce particularly remarkable effects.

100 Copper thin film 101, 103 Plating 102 Resist 200 Copper material L Loop coil V Via S1 Power transmission system RV Power receiving section RC1, RC2 Power receiving coil R1 Power receiving device TR Power transmitting section TC1 Power transmitting coil T1 Power transmitting device O1, O2, O21, O22, O31, O32 External connection terminal MT Thin film material DE Punching die BF Film GP Gap H1, H2 Hole RL1, RL2, RL3 Power receiving loop coil RL21, RL22, RL31, RL32 Copper thin film wire CN1 Curved member RL101, RL102, RL103, RL104, RL105, RL106, RL107, RL108, RL109, RL110, RL111, RL112, RL113, RL114, RL115, RL116, RL117, RL118, RL119, RL120121, RL122, RL123, RL124, RL125 Straight member RL2101, RL2102, RL2103, RL2104, RL2105, RL2106, RL2107, RL2108, RL2109, RL2110, RL2111, RL2112, RL2113, RL2114, RL2115, RL2116, RL2117, RL 2118, RL2119, RL2120, RL2121, RL2122, RL2123, RL2124, RL2125 , RL2201, RL2202, RL2203, RL2204, RL2205, RL2206, RL2207, RL2208, RL2209, RL2210, RL2211, RL2212, RL2213, RL2214, RL2215, RL2216, RL2217, R L2218, RL2219, RL2220, RL2221, RL2222, RL2223, RL2224, RL2225 ,RL3101,RL3102,RL3103,RL3104,RL3105,RL3106,RL3107,RL3108,RL3109,RL3110,RL3111,RL3112,RL3113,RL3114,RL3115,RL3116,RL3117,R L3118, RL3119, RL3120, RL3121, RL3122, RL3123, RL3124, RL3125 , RL3201, RL3202, RL3203, RL3204, RL3205, RL3206, RL3207, RL3208, RL3209, RL3210, RL3211, RL3212, RL3213, RL3214, RL3215, RL3216, RL3217, RL3218, RL3219, RL3220, RL3221, RL3222, RL3223, RL3224, RL3225 Thin film wire members

Claims (5)

A method for manufacturing a coil for contactless power transmission , the coil being formed by winding a winding circuit having a plurality of straight portions made of a thin-film conductor and a plurality of curved portions made of a thin -film conductor, comprising:
a partial winding manufacturing process for manufacturing a plurality of partial windings made of the thin film conductor and connected in a winding direction of the coil to form the winding , each partial winding having one of the straight portions and one of the curved portions continuing from the one of the straight portions ;
a winding manufacturing process in which the respective manufactured partial windings are arranged in the winding direction and electrically connected to manufacture the winding;
Including,
each said curved portion is a curved portion for bending said winding wire to form said turns;
The width of each of the partial windings is the same;
A method for manufacturing a coil, characterized in that a plurality of partial windings that are connected at different positions in the winding to form the winding have the same shape. The method for manufacturing a coil according to claim 1,
A method for manufacturing a coil, characterized in that the identical shape is a shape that is symmetrical when viewed from the center of the winding. The method for manufacturing a coil according to claim 1 or 2,
A coil manufacturing method characterized in that in the partial winding manufacturing process, each of the partial windings is manufactured using at least one of a casting method and a die-cutting method using a mold having a shape corresponding to the same shape. The method for manufacturing a coil according to any one of claims 1 to 3,
A method for manufacturing a coil , further comprising a lamination step of laminating the windings manufactured in the winding manufacturing step with an insulating layer sandwiched therebetween . The method for manufacturing a coil according to claim 4,
The lamination step includes:
an insertion step of inserting a conductor post into a hole for conductive connection formed in each of the windings after laminating the windings;
a conductive step of deforming the inserted conductor pole to conductively connect each of the windings;
A method for manufacturing a coil, comprising :

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