JP7460038B1 - Flexible conductors and electrical equipment - Google Patents

Abstract

The present invention provides a flexible conductor having a small electrical resistance value by comprising a plurality of copper foils laminated in a thickness direction, the laminated copper foils being ultrasonically bonded to each other at both ends in the extension direction of the copper foils.The present invention also provides an electrical device including the flexible conductor, a movable part fastened to the first end of the flexible conductor, and a terminal fastened to the second end of the flexible conductor.

Description

The present disclosure relates to an ultrasonically bonded flexible conductor and an electrical device including the flexible conductor.

Prior art discloses a flexible conductor that includes a conductive and flexible flexible portion formed by stacking multiple thin copper plates, and terminal portions provided at both ends of the flexible portion, and that in manufacturing this flexible conductor, the thin plates are tin-plated, and the tin plating is melted by resistance welding or the like to join the stacked thin plates (for example, Patent Document 1).

Japanese Patent Application Publication No. 2013-131434

However, in the conventional method of joining laminated copper foils by melting the tin plating, the joining is performed via the plating layer. Therefore, when electricity is applied, current flows through the tin plating layer, which has a higher electrical resistance than copper, resulting in an issue of increased electrical resistance compared to a flexible conductor made of copper foil without tin plating.

The present disclosure has been made in order to solve the above problems, and aims to provide a flexible conductor in which a plurality of copper foils are ultrasonically bonded, and an electrical device equipped with the flexible conductor. do.

The flexible conductor according to the present disclosure comprises a plurality of copper foils stacked in the thickness direction, and among the plurality of copper foils, the outermost copper foil has a fastening surface for fastening to a mating component on a surface different from the surface on which it is stacked, and the plurality of stacked copper foils are ultrasonically joined to each other at the corners of the copper foil on the fastening surface.
In addition, the flexible conductor according to the present disclosure comprises a plurality of copper foils stacked in the thickness direction, and among the plurality of copper foils, the copper foil located at the outermost position is fastened to a mating member on a surface different from the surface on which it is stacked, has a fastening surface having a plating layer, and the stacked plurality of copper foils are ultrasonically joined to each other in the region corresponding to the fastening surface and at both ends in the extension direction of the copper foil.

The electrical device disclosed herein also includes the above-mentioned flexible conductor, and, of the first end and second end of the flexible conductor, a movable part that is fastened to the first end and a terminal to which the second end is fastened.

According to the flexible conductor according to the present disclosure, it is possible to provide a flexible conductor that has a smaller electric resistance value when energized than a conventional flexible conductor in which laminated copper foils are bonded by tin plating. Further, according to the electrical device according to the present disclosure, it is possible to provide an electrical device with a small electrical resistance value.

FIG. 2 is a schematic side view showing a state in which a switch including a flexible conductor according to Embodiment 1 of the present disclosure is open; 1 is a schematic side view showing a state in which a switch including a flexible conductor according to a first embodiment of the present disclosure is closed; FIG. 1 is a perspective view of a flexible conductor according to Embodiment 1 of the present disclosure. FIG. 11 is a perspective view of a flexible conductor according to a second embodiment of the present disclosure. FIG. 7 is a perspective view of a flexible conductor according to Embodiment 3 of the present disclosure. 6 is a schematic diagram of a flexible conductor according to a third embodiment of the present disclosure, corresponding to a cross section taken along line AA' in FIG. 5.

Embodiments of the present disclosure will be described below with reference to the accompanying drawings. Note that the drawings are schematically shown, and the mutual relationships of sizes and positions shown in different drawings are not necessarily accurately described and may be changed as appropriate. In addition, in the following description, similar components are shown with the same reference numerals, and their names and functions are also the same or similar. Therefore, detailed explanations about them may be omitted.

Embodiment 1.
The flexible conductor 1 in the first embodiment will be described with reference to Figures 1, 2 and 3. Figure 1 is a schematic side view showing a state in which a switch 11 including the flexible conductor 1 in the first embodiment is in an open state, that is, a state in which a movable contact 4 and a fixed contact 5, which will be described later, are not in contact with each other. For the sake of convenience, in Figure 1, a part of the front surface of the vacuum interrupter 16 is omitted to show the inside of the vacuum interrupter 16.

As shown in FIG. 1, the switch 11 according to the present embodiment includes a flexible conductor 1, a first terminal 12 (a fixed terminal on the flexible conductor side electrically connected to the movable contact 4 via the flexible conductor 1), a driving device tip 13, a first movable part 14 (a movable part connected to the movable contact 4), a vacuum valve 16, a fixed part 17 (a movable part connected to the fixed contact 5), a second terminal 19 (a fixed terminal on the vacuum valve side electrically connected to the fixed contact 5), a bolt 20 and a nut 23 that fix the first terminal 12 and the flexible conductor 1, a bolt 21 that fixes the fixed part 17 and the second terminal 19, and a nut 22 that fixes the first movable part 14, the flexible conductor 1, and the driving device tip 13. The switch 11 includes the fixed contact 5 and the fixed part 17 as fixed members, and the movable contact 4 and the first movable part 14 as movable parts.

The flexible conductor 1 includes a conductive and flexible flexible portion 38, a first end 32, and a second end 33. The first end 32 and the second end 33 are located so as to sandwich both ends of the flexible portion 38. Here, the first end 32 and the second end 33 may be a portion on one end side or the other end side of the flexible portion 38. In other words, the first end 32 and the second end 33 of the flexible conductor 1 are not limited to edges, etc., but may be a portion excluding the flexible portion 38. For example, if the flexible portion 38 is not in the center of the flexible conductor 1 but is located off the center, one end may be the central portion of the flexible conductor 1.

The first end 32 of the flexible conductor 1 is fastened to the driving device tip 13 and the first movable part 14, for example, by a nut 22. That is, the first end 32 of the flexible conductor 1 is connected to the movable part of the switch 11. That is, the first end 32 of the flexible conductor 1 is electrically connected to the first movable part 14.

In addition, the first end 32 of the flexible conductor 1 only needs to be connected to the first movable part 14, and does not need to be connected to the driving device tip 13.

The drive device tip 13 and the first movable part 14 are fastened with a nut 22.

Further, the drive device tip 13 is connected to an external drive device (not shown). The drive device is driven by, for example, the force of a spring. Note that the drive device includes an insulating rod connected to the first movable part 14.

The second end 33 of the flexible conductor 1 is fastened to the first terminal 12, for example, by a bolt 20 and a nut 23. That is, the second end 33 of the flexible conductor 1 of the switch 11 is connected to the fixed part of the switch 11. The second end 33 of the flexible conductor 1 is also electrically connected to the first terminal 12.

Note that the first end 32 and second end 33 that are coupled to the driving device tip 13, the first movable part 14, and the first terminal 12 as mating members are the outer peripheral part of the flexible conductor 1 or This does not mean only the end portion, and the portion that is coupled to the mating member may be located closer to the center than the outer periphery of the flexible conductor 1.

The fixed portion 17 and the second terminal 19 are fastened with a bolt 21. The fixed portion 17 and the second terminal 19 are also electrically connected.

Figure 2 is a schematic side view showing the state in which the switch 11 including the flexible conductor 1 of embodiment 1 is closed, i.e., the state in which the movable contact 4 and the fixed contact 5 are in contact. For ease of explanation, in Figure 2, part of the front of the vacuum valve 16 is omitted to show the inside of the vacuum valve 16. In Figure 2, the same reference numerals as in Figure 1 indicate the same configuration, so explanations are omitted.

As shown in Figure 2, the movable contact 4 and the fixed contact 5 in the vacuum valve 16 are in contact. In other words, the electrical circuit of the switch 11 is in a closed state.

The driving device transmits power to the driving device tip 13 to move in the direction of the arrow shown in Figure 2. When the power is transmitted to the driving device tip 13, the power is transmitted to the first movable part 14 connected to the driving device tip 13.

As power is transmitted from the driving device tip 13 to the first movable part 14, the movable contact 4 moves in a direction approaching the fixed contact 5. As the movable contact 4 moves, the movable contact 4 and the fixed contact 5 come into contact, and the switch 11 in the open state shown in FIG. 1 transitions to the switch 11 in the closed state shown in FIG. 2. .

The flexible conductor 1 follows the movement of the first movable part 14 when the switch 11 transitions from an open state to a closed state and from a closed state to an open state.

The switch 11 to which the flexible conductor 1 of the present invention is applied is not limited to a circuit breaker using a vacuum valve, but may be other electrical equipment such as a disconnector in which a fixed part and a movable part are electrically connected. The flexible conductor 1 can be easily used for switches and other electrical equipment having a different configuration from the switch 11 of the present embodiment.

FIG. 3 is a perspective view of the flexible conductor 1 according to the first embodiment.

The flexible conductor 1 includes a plurality of copper foils 41 laminated in the thickness direction. The plurality of copper foils 41 are, for example, rectangular with long sides and short sides. The thickness of the copper foil 41 is, for example, about 0.1 mm.

Further, the flexible conductor 1 includes an ultrasonic bonding portion 34, a fastening surface 35, and a fastening hole 36. For example, the ultrasonic bonding portions 34 are located at both ends of the plurality of copper foils 41 in the long side direction.

3, among the multiple copper foils 41 included in the flexible conductor 1, the outermost copper foil 42 has a fastening surface 35 that is fastened to a mating member on a surface different from the surface on which it is laminated, that is, on a surface different from the surface on which the two copper foils located on the outermost sides are laminated in the lamination direction when the multiple copper foils 41 are laminated. Hereinafter, the fastening surface is not the entire surface of the surface layer of the flexible conductor 1, but the surface of the surface layer excluding the flexible part 38. The area where the flexible conductor 1 is fastened to the mating member may be a part of the fastening surface 35, and may be in contact with the first movable part 14 at the fastening area 37 shown in FIG. 3, for example.

At the ultrasonic joint 34 of the flexible conductor 1, multiple laminated copper foils 41 are ultrasonically joined to each other. The ultrasonic joint 34 refers to the portion where multiple laminated copper foils 41 are ultrasonically joined to each other.

As shown in Figure 3, in the flexible conductor 1 of this embodiment, the ultrasonic joints 34 are located at locations on the fastening surface 35 that correspond to the four corners of the copper foil 41.

The x marks shown in FIG. 3 are processing marks generated on the conductor surface during ultrasonic bonding. Machining marks occur at positions sandwiched between the horn and anvil of the ultrasonic bonding device. Although FIG. 3 shows a case where three processing marks exist at each of the four corners of the copper foil 41 where the ultrasonic bonding portion 34 is located, the number of processing marks is not limited to three.

Further, the position of the ultrasonic bonding portion 34 is not limited to the four corners of the copper foil 41 as long as the flexibility of the flexible conductor 1 is not impaired.

Furthermore, as shown in FIG. 4, the ultrasonic bonding portion 34 to which ultrasonic bonding is performed is not limited to the outer peripheral portion of the flexible conductor 1, but may be provided in the central portion such as a portion adjacent to the fastening hole 36. Good too. Further, it may be provided in areas other than the fastening area 37.

In the ultrasonic bonding portion 34 of the flexible conductor 1, adjacent copper foils 41 are bonded and integrated by applying ultrasonic vibration to the copper foil 41 when ultrasonic bonding is performed.

Since the ultrasonic bonding part 34 of the flexible conductor 1 is joined and the plurality of copper foils 41 are integrated in the thickness direction, each copper foil 41 can be separated when attaching the flexible conductor 1 to a movable part or a terminal. The flexible conductor 1 can be easily electrically connected to the driving device tip 13, the first movable part 14, the first terminal 12, etc. of the switch 11 without causing any damage.

In a portion of the flexible conductor 1 other than the ultrasonic bonding portion 34, the copper foils 41 are not bonded to each other. Since the copper foils 41 are not bonded to each other, the copper foils 41 can be bent freely, and the flexible conductor 1 can follow the movement of the first movable part 14.

It is desirable that the multiple copper foils 41 of the flexible conductor 1 are ultrasonically bonded to each other in the region corresponding to the fastening surface 35. It is also desirable that the ultrasonic bonded portion 34 at least partially overlaps with the region corresponding to the fastening region 37. The region corresponding to the fastening surface 35 refers to the region of the copper foil 41 onto which the fastening surface 35 is projected in the thickness direction of the flexible conductor 1.

By applying ultrasonic bonding to the ultrasonic bonding portion 34 that overlaps at least a portion of the fastening region 37, the bonding at the ultrasonic bonding portion 34 can be performed in addition to the bonding by ultrasonic bonding when the flexible conductor 1 is attached. By pressing the region 37, contact resistance can be suppressed, and the electrical resistance can be lowered compared to simply ultrasonically bonded.

Ultrasonic bonding can solid phase bond copper foils together. The flexible conductor 1 according to the present embodiment is bonded by ultrasonic bonding with the base copper foil intact, so unlike the method of bonding the copper foil by melting the tin plating by spot welding, the bonding Therefore, it is not necessary to plate each copper foil 41 with tin or the like.

In this way, the electrical resistance of the flexible conductor 1 can be reduced by directly bonding the copper foils as they are as base copper foils, without using tin plating, which has a higher electrical resistance than the copper foils, to connect each copper foil 41. The value can be lower than that of conventional connections using plating. Therefore, when creating a flexible conductor with the same resistance value, the number of copper foils 41 forming the flexible conductor 1 can be reduced compared to a flexible conductor using tin plating.

In addition, since each copper foil 41 is not plated, the process of plating the copper foil 41 can be omitted, thereby reducing manufacturing costs.

There is also a method of spot welding raw copper foil to create a flexible conductor, but since the copper melts at high temperatures, an oxide film is formed on the surface, so it is necessary to remove the oxide film. In the case of ultrasonic bonding, since bonding is performed in a solid state, bonding can be performed below the melting point of the base material such as copper, and no oxide film is generated.

In the ultrasonic bonding section 34, it is desirable that the stacked copper foils 41 be ultrasonically bonded without using a plating layer, but some layers may be bonded via a plating layer.

As shown in FIG. 3, the flexible conductor 1 has a fastening hole 36 in a fastening surface 35. As shown in FIG. The flexible conductor 1 is fastened to a mating member through the fastening hole 36. When fastening, bolts 20, nuts 22, and nuts 23 are used. When the flexible conductor 1 is fastened to a mating member through the fastening hole 36, the fastening is not limited to bolts and nuts, but may be done by fitting, welding, or the like.

Since the flexible conductor 1 has the fastening hole 36, it is easier to apply it to a switch different from the switch 11 of this embodiment and other electrical equipment than when the flexible conductor 1 does not have the fastening hole 36. Become.

Note that the fastening hole 36 may not be provided.

Next, we will explain the manufacturing method of the switch 11 in this embodiment.

First, the flexible conductor 1 of the first embodiment, i.e., the flexible conductor 1 in which each layer is ultrasonically bonded to each other, the vacuum valve 16, and the switch 11 to which the vacuum valve is attached (excluding the vacuum valve 16, the flexible conductor 1, etc.) are prepared. The ultrasonically bonded flexible conductor 1 can be manufactured by applying ultrasonic vibration between the copper foils 41 laminated in the thickness direction. The manufacturing method of the flexible conductor 1 will be described in detail later.

Next, the vacuum valve 16 is attached to the switch 11, and then the flexible conductor 1 is attached to the first movable part 14 (movable electrode rod) connected to the vacuum valve 16. The first movable part 14 is attached to the first movable part 14 through the fastening hole 36 so that the first movable part 14 penetrates the fastening hole 36 of the flexible conductor 1, and the first movable part 14 and the flexible conductor 1 are connected. At this time, each copper foil 41 of the flexible conductor 1 is ultrasonically bonded at the ultrasonic bonding part 34, and each copper foil 41 does not come apart, so it can be easily attached to the first movable part 14. The first movable part 14 and the flexible conductor 1 can be attached by fastening with a nut. The first movable part 14 and the flexible conductor 1 can be attached by other methods such as fitting, without being limited to fastening with a nut.

Next, the flexible conductor 1 is attached to the first terminal 12. It can be attached by aligning the fastening hole of the first terminal 12 and the fastening hole 36 of the flexible conductor 1, and fixing it with the nut 23 through the bolt 20. The attachment of the first movable part 14 and the flexible conductor 1 is not limited to fastening with bolts, but may be done by other methods such as fitting.

Note that the order of attachment is not limited to the above, and the order of attachment may be changed as appropriate, such as by bonding a part of the flexible conductor 1 in advance before attaching the vacuum valve 16 to the switch 11. Further, although the method for manufacturing the switch 11 having the vacuum valve 16 has been described here, other electrical equipment such as a disconnector can be manufactured in the same manner.

Embodiment 2.
The flexible conductor 2 in Embodiment 2 will be explained using FIG. 4. Descriptions of configurations similar to those in Embodiment 1 will be omitted. Further, in FIG. 4, the same reference numerals as in FIGS. 1 to 3 indicate the same or corresponding parts.

Figure 4 is a perspective view of the flexible conductor 2 according to embodiment 2. As shown in Figure 4, the flexible conductor 2 of this embodiment differs from the flexible conductor 1 of embodiment 1 in the position of the ultrasonic joint 34. Below, the differences from the flexible conductor 1 of embodiment 1 will be mainly explained.

As shown in Figure 4, in the flexible conductor 2 according to this embodiment, the ultrasonic joint 34 is located in a range of the fastening surface 35 that includes the fastening hole 36. In other words, the ultrasonic joint 34 is included in the fastening surface 35. Note that the ultrasonic joint 34 and the fastening surface 35 may partially overlap.

In this way, the ultrasonic joint 34 may be provided in a portion adjacent to the fastening hole 36. By ultrasonically joining the portion adjacent to the fastening hole 36, when the flexible conductor 2 is attached and fastened with a bolt or nut, pressure is applied, making the contact stronger and further reducing the contact resistance.

By applying ultrasonic bonding to the area including the fastening holes 36, which are the current path, the copper foils 41 in the current path are firmly bonded together. By firmly bonding the copper foils 41 together, the electrical resistance of the flexible conductor 2 can be reduced compared to when the copper foils 41 are fastened with bolts and nuts. In addition, if it is not necessary to reduce the electrical resistance of the flexible conductor 2, the number of copper foils 41 that form the flexible conductor 2 can be reduced.

The x marks shown in FIG. 4 are processing marks generated on the conductor surface during ultrasonic bonding. After ultrasonic bonding, machining marks remain on the fastening surface 35 that is fastened to the mating member, but since the machining marks have a concave shape, they do not affect the contact with the mating member. The number of machining marks is not limited to the number shown. Further, the arrangement pattern of processing marks may be arranged in a grid pattern, for example.

Embodiment 3.
The flexible conductor 3 in Embodiment 3 will be explained using FIGS. 5 and 6. Descriptions of configurations similar to those in Embodiment 1 will be omitted. Further, in FIGS. 5 and 6, the same reference numerals as in FIGS. 1 to 4 indicate the same or corresponding parts.

Figure 5 is a perspective view of the flexible conductor 3 according to embodiment 3. Figure 6 is a schematic diagram of the flexible conductor 3 according to embodiment 3 corresponding to a cross section taken along line A-A' in Figure 5. The flexible conductor 3 of this embodiment differs from the flexible conductor 1 of embodiment 1 in that a plating layer is provided on the copper foil 42. The following will focus on the differences from the flexible conductor 1 of embodiment 1.

The flexible conductor 3 in this embodiment is located at the outermost position among the multiple copper foils 41, and the copper foil 42 that is fastened to the mating member has a plating layer of tin or the like on the side that is fastened to the mating member.

The area on which the plating layer is provided may be the entire side on which the copper foil 42 is fastened to the opposing member, or, for example, only the fastening surface 35.

When the base copper foil is exposed to oxygen for a long time, an oxide film is formed on the surface. In order to prevent the formation of an oxide film, it is conceivable to plate all the copper foils.

When using a plating such as tin that melts due to the frictional heat generated by ultrasonic bonding, the frictional heat generated between the copper foils 41 melts the plating before bonding is completed in the solid phase, causing slippage between the copper foils. Slippage prevents the ultrasonic vibrations from being transmitted, resulting in poor bonding.

By providing a plating layer only on the side of the copper foil 42 that is fastened to the mating member, slippage between the copper foils 41 is suppressed and bonding defects are not caused. Note that since the ultrasonic bonding portion 34 of the copper foil 41 is firmly bonded, no oxide film is generated on the copper foil 41 bonded to other copper foils 41.

It should be noted that, among the copper foils 41, the outermost copper foil on the side opposite to the copper foil 42 to be fastened to the mating member has a plating layer on the whole or part of the side opposite to the fastening surface 35 of the copper foil 42. may be provided.

In addition, it is desirable to apply plating only to the side of the copper foil 42 that is fastened to the mating member, but a plating layer may be provided on a part of the side of the copper foil 42 that is not fastened to the mating member, or a plating layer may be provided on a part of the other copper foil 41.

For plating, a material suitable for the temperature during ultrasonic bonding, such as tin or silver, is preferably used.

Although FIG. 6 shows a state in which there are ten copper foils 41, the number of copper foils 41 is not limited to ten.

Next, a method for manufacturing the flexible conductor according to the first to third embodiments will be described. The method for manufacturing the flexible conductor according to the first to third embodiments includes step 101 of stacking multiple copper foils 41 in the thickness direction, and step 102 of ultrasonically joining the multiple stacked copper foils 41 to each other at both ends in the extension direction of the stacked copper foils 41.

In addition, the above step 102 of ultrasonically joining the stacked copper foils 41 to each other may include step 102a of ultrasonically joining the stacked copper foils 41 to each other on the fastening surface 35 of the flexible conductor.

Further, the step 102 of ultrasonically bonding the plurality of stacked copper foils 41 to each other includes step 102b of ultrasonically bonding the plurality of stacked copper foils 41 to each other at the corners of the stacked copper foils 41. be able to.

Furthermore, the flexible conductor manufacturing method according to Embodiments 1 to 3 includes a step 103 of forming a plating layer on the fastening surface 35 of the copper foil 41, and the step 103 of forming the plating layer is performed before step 101. Alternatively, it may be performed between the above step 101 and the above steps 102, 102a and 102b, or even after the above steps 102, 102a and 102b.

That is, in order to produce an ultrasonically bonded flexible conductor, the copper foil 41 laminated in the thickness direction is sandwiched between the horn and anvil attached to the ultrasonic bonding machine, and the copper foil 41 is exposed to ultrasonic waves while applying pressure. All you have to do is transmit vibrations. By doing so, the oxide film and dirt on the bonding interface are removed, and the crystal grains between the copper foils 41 approach each other until they reach the atomic distance, so that the copper foils 41 can be bonded.

Note that in each of the above embodiments described in this specification, the material, ingredients, dimensions, shape, relative positional relationship, or implementation conditions of each component may be described, but these are merely examples in all respects and each embodiment is not limited to what has been described. Thus, countless variations not exemplified are anticipated within the scope of each embodiment. For example, this includes cases in which any component is modified, added, or omitted, and further cases in which at least one component in at least one embodiment is extracted and combined with a component of another embodiment.

1, 2, 3 flexible conductor, 11 switch, 12 first terminal, 14 first movable part, 16 vacuum valve, 17 fixed part, 32 first end, 33 second end, 35 fastening Surface, 36 Fastening holes, 41, 42 Copper foil

Claims (5)

Equipped with multiple copper foils laminated in the thickness direction,
Among the plurality of copper foils, the outermost copper foil has a fastening surface that is fastened to a mating member on a surface different from the surface on which it is laminated,
A flexible conductor in which a plurality of stacked copper foils are ultrasonically bonded to each other at a corner of the copper foil on the fastening surface . Equipped with multiple copper foils laminated in the thickness direction,
Among the plurality of copper foils, the copper foil located at the outermost position has a fastening surface that is fastened to a mating member on a surface different from the surface on which the copper foil is laminated and has a plating layer,
A flexible conductor in which a plurality of laminated copper foils are ultrasonically bonded to each other in a region corresponding to the fastening surface and at both ends in the stretching direction of the copper foil. 2. The flexible conductor of claim 1 , wherein said fastening surface includes fastening holes. 3. The flexible conductor of claim 2, wherein said fastening surface includes fastening holes. A flexible conductor according to any one of claims 1 to 4 ,
A movable part that is fastened to the first end of the first end and the second end of the flexible conductor;
a terminal to which the second end is fastened;
Electrical equipment with.

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