Method and apparatus for manufacturing busbars

Abstract

The present invention provides a method and apparatus for manufacturing busbars that can coat flat conductors with insulating resin with high adhesion by extrusion molding. [Solution] After the surface of a strip-shaped conductor material 1 is given a textured finish, an insulating resin formed into a fluid state by extrusion molding is supplied to the textured surface of the conductor material 1 to form an insulating resin layer surrounding the surface of the conductor material 1. Subsequently, the insulating resin is cooled to solidify. As a result, the insulating resin film formed on the surface of the conductor material 1 adheres firmly to the surface of the conductor material 1.

Description

Technical Field

[0001] The present invention relates to a method and an apparatus for manufacturing a bus bar used in a power supply circuit of an automobile, a solar cell module, or the like, and particularly relates to a method for manufacturing a bus bar provided with an insulating resin coating.

Background Art

[0002] In a power supply circuit of an automobile or the like, a flat bus bar made of copper or aluminum is used to connect a battery and various electrical components. Further, in order to prevent a short circuit between this bus bar and a vehicle body or another bus bar, the bus bar is coated with an insulating resin.

[0003] Such a bus bar having an insulating film is manufactured, for example, by applying an insulating resin to a conductive member cut into the shape of a bus bar product and then curing this. Specifically, as the insulating resin, a thermosetting resin or an ultraviolet curable resin is applied to the conductive member, and then heat is applied to cure it or ultraviolet light is irradiated to cure the resin (Patent Document 1). In this Patent Document 1, in order to prevent the thickness of the insulating film at the edge portion of the conductive member from becoming insufficient, the elongation rate and Young's modulus after curing of the photocurable insulating film are defined within a predetermined range.

[0004] Further, Patent Document 2 discloses a coated conductive member having a plate-shaped conductor, a plurality of linear conductors arranged along this plate-shaped conductor, and an insulating resin material extruded so as to surround them, and integrally forming the plate-shaped conductor and the linear conductors. This Patent Document 2 is obtained by integrally extruding a resin for a plate-shaped conductor and a plurality of linear conductors, and like Patent Document 1, manufactures by individually resin-coating bus bar products.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

[0006] When resin coating is applied by resin extrusion, it has the advantage of higher production efficiency compared to heat curing of thermosetting resins and light curing of photocurable resins. However, resin-coated conductors, in which resin is applied to the surface of a conductor by extrusion molding, are bent or twisted into complex shapes to route the various contacts of electrical components such as those in automobiles. In this way, electrical components are connected by busbars bent or twisted into various shapes.

[0007] In this case, conventional extruded busbars have poor adhesion between the resin coating and the flat conductor. When bent to fit the contact point for connection to electrical components, the resin coating may peel off in layers from the flat conductor at the bent portion, exposing the conductor. This destroys the insulation properties of the conductor, rendering it unusable as wiring.

[0008] The present invention has been made in view of the above problems, and aims to provide a method and apparatus for manufacturing a busbar that can coat a flat conductor with an insulating resin with high adhesion by extrusion molding. [Means for solving the problem]

[0009] The method for manufacturing a bus bar according to the present invention is: The busbar is manufactured by applying a textured finish to the surface of a strip-shaped conductor made of copper, aluminum, or an alloy thereof using a shot blasting method to create irregularities on the surface, extruding a polyamide insulating resin onto the surface of the conductor without preheating, and then cutting the extruded resin.

[0010] The busbar manufacturing apparatus according to the present invention is A supply unit that supplies a strip-shaped conductor made of copper, aluminum, or an alloy thereof in one direction, The surface of the conductor is processed to create a textured surface by shot blasting, forming an uneven surface. An extrusion molding section is provided to the conductor after the textured finish, by extruding a polyamide insulating resin without preheating the conductor, thereby forming an insulating resin layer surrounding the surface of the conductor. A winding section for winding the conductor on which an insulating coating layer has been formed, It is characterized by having the following features. [Effects of the Invention]

[0011] According to the present invention, after the surface of a strip-shaped conductor is textured, an insulating resin formed into a fluid state by extrusion molding is supplied to the textured surface of the conductor material, and then the insulating resin is cooled to solidify. As a result, the insulating resin coating formed on the surface of the conductor adheres firmly to the surface of the conductor, and even when the busbar is bent after being cut to a predetermined length, the insulating resin coating is prevented from peeling off from the conductor. Furthermore, in the present invention, since the resin is extruded without preheating the material after blast treatment, the resin coating can be easily peeled off when peeling off the resin coating at both ends of the busbar. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic diagram illustrating an embodiment of the present invention. [Figure 2] This is a plan view showing the configuration of an extrusion molding machine. [Modes for carrying out the invention]

[0013] Embodiments of the present invention will be described in detail below with reference to the attached drawings. Figure 1 is a schematic diagram showing a busbar manufacturing apparatus according to an embodiment of the present invention. A busbar material 1 with a rectangular cross-section is wound around the supply roller 2. This busbar material 1 is made of copper or aluminum wire (including alloys) or other metals or alloys, and is formed into a rectangular shape in a conventional process and then wound onto the supply roller 2.

[0014] The material 1, unwound from the supply roller 2, passes through the textured finish device 3, the resin extrusion molding machine 4, and the water tank 5, and is then taken up by the take-up machine 6. The material 1, driven to the take-up machine 6, is then subjected to textured finishing on its surface by the textured finish device 3. This textured finishing is a method of finishing the surface of the material 1 by mechanically or chemically roughening it. The surface state after textured finishing can be glossy, semi-glossy, or matte, and processing methods include shot blasting, sandblasting, wire brushing, and dispersion plating. In this embodiment, it is preferable to use the shot blasting method for textured finishing. In this shot blasting method, there is an air blasting method in which fine abrasive material is carried by compressed air and blown onto the surface of the material 1, and an impeller blasting method in which fine abrasive material is blown onto the surface of the material 1 by the wind force from the rotation of an impeller. In addition, although fine iron particles can be used as abrasive material, it is preferable to use fine alumina particles to avoid them adhering to the surface of the material as rust. Furthermore, in this textured finish process, it is preferable to form irregularities with a depth of 30 to 50 μm on the surface of material 1. In addition, the impact of the abrasive material removes material 1 from its surface, forming uniform, fine, and complexly shaped irregularities on the surface of material 1 that do not have a specific direction.

[0015] Next, the material 1 is coated with resin by a resin extrusion molding machine 4, which supplies resin to its surface. Figure 2 is a schematic plan view showing the configuration of the resin extrusion molding machine 4. The material 1 moves horizontally and passes through the resin molding die 11 of the resin extrusion molding machine 4. A fluid resin is supplied to the resin molding die 11 from the resin supply unit 12, and the resin is applied to the periphery of the material 1 inside the resin molding die 11. In the resin supply unit 12, a screw 13 is installed horizontally with its axial direction facing the resin molding die 11. A hopper 15 is installed above the rear end of the screw 13, and resin pellets stored in the hopper 15 are supplied from the lower end of the hopper 15 to the rear end of the screw 13. The screw 13 is housed in a housing 14, and the end of the housing 14 on the resin molding die 11 side is connected to the resin molding die 11 by a resin flow path 16. The temperature inside the housing 14 is adjusted to approximately 230-250°C, and the resin pellets supplied from the hopper 15 to the screw 13 melt within this housing. This molten resin is extruded toward the resin molding die 11 by the rotation of the screw 13, supplied to the resin molding die 11 with appropriate pressure, and coated onto the surface of the rectangular material 1 within the resin molding die 11.

[0016] As for the resin material, it is preferable to use one that has high adhesion to material 1, such as copper or aluminum (including its alloys), and has high insulation and high wear resistance, but polyamide can be used, for example.

[0017] On the surface of the material 1, the coated material 11 coated with the resin in a flowing state is then passed through the water tank 5 and cooled by water. As a result, the coated resin is cooled and adheres to the surface of the coated material 11. Then, after the coated material 11 after resin coating is pulled by the take-up machine 6, it is temporarily accumulated in the accumulator 7. Thereafter, the coated material 11 is supplied to the measuring unit 8. After the thickness of the insulating resin-coated material 11 and the inspection for the presence or absence of defects such as pinholes are carried out by the measuring unit 8, it is wound by the winding machine 9. The coil of the coated material 11 wound by the winding machine 9 is transferred to the next process and cut into a predetermined size. Then, the cut insulating resin-coated material 11 is used as a bus bar for the wiring circuit of an automobile or the like.

[0018] Next, the operation of the bus bar manufacturing apparatus configured as described above will be described. The bus bar material 1 such as copper having a flat rectangular cross section is mounted on the supply roller 2 in a state of being wound in a coil shape. Then, the material 1 unwound from this material coil is taken by the take-up machine 6 and supplied from the supply roller 2 to the embossing device 3. And, embossing is performed on the surface of the material 1 such as copper by a method such as shot blasting. By this embossing, irregularities having a depth of about 30 to 50 μm, for example, are formed on the surface of the material 1 as described above.

[0019] The material 1 having fine irregularities formed on the surface by this embossing is then supplied to the resin extrusion molding machine 4. In this resin extrusion molding machine 4, a molten resin such as polyamide is applied to the surface of the material 1. That is, the pellets of the polyamide resin stored in the hopper 15 are introduced from the hopper 15 to the rear end of the screw 13, and the resin pellets are heated and melted in the housing 14 and extruded toward the resin molding die 11 by the rotation of the screw 13. Then, when the material 1 passes through the resin molding die 11, the molten resin is supplied to the surface of the material 1 in the resin molding die 11, and the molten resin is applied to the surface of the material 1 so as to surround the material 1.

[0020] This resin-coated coated material 10 is taken by the take-up machine 6 and passed through the water tank 5, and is cooled in the water tank 5, so that the resin on the surface of the material 1 solidifies.

[0021] Then, the coated material 10 coated with resin is supplied from the take-up machine 6 to the accumulator 7, the moving speed is adjusted, and it is sent to the measuring unit 8. In the measuring unit 8, the thickness of the coated material 10 is measured and defects are inspected. After that, the coated material 10 is wound around the winding machine 9 in a coil shape. This coiled coated material 10 is conveyed to another line, cut to a predetermined length, and becomes a bus bar product.

[0022] This bus bar is bent, twisted, and deformed according to the circuit terminals in order to wire the circuits of automobiles and the like, and connects between the circuit terminals. At this time, in this embodiment, since the resin is applied and solidified on the surface of the material 1 roughened by embossing, the resin adheres closely to the surface of the material 1. As a bus bar product, even if it is bent or twisted, it is possible to prevent the resin part from peeling off from the surface of the material 1.

[0023] Also, in this embodiment, the material 1 after the blasting process moves to the resin extrusion molding process without being heated. Usually, when trying to coat the surface of a material with resin, in order to improve the adhesiveness of the coated resin, the material is heated and preheated, and then the resin is extruded onto its surface. However, if this is done, when using the bus bar after cutting the resin-coated material 10 for wiring and trying to form contacts by peeling off the coated resin at both ends of the bus bar, the peelability of the resin at both ends is poor and it is difficult to form contacts. Therefore, the material 1 after the blasting process is subjected to resin extrusion molding without preheating. However, in this embodiment, since the resin is extruded after embossing the surface of the material 1, the resin adheres firmly to the surface of the material 1, and when peeling off the coated resin at both ends of the bus bar, the resin can be easily peeled off.

Industrial Applicability

[0024] According to the present invention, since the surface of a strip-shaped conductor is textured and then an insulating resin is extruded onto the surface of the conductor to manufacture the busbar, even if the busbar is bent or twisted to fit the wiring location, the coating resin will not peel off and the insulation of the busbar will not be destroyed. Therefore, the ease of installation of the busbar into the electrical circuit is improved, which is beneficial for improving the efficiency of wiring work using the busbar. [Explanation of Symbols]

[0025] 1: Material 2: Supply roller 3: Pear-textured finish processing equipment 4: Resin extrusion molding machine 5: Aquarium 10: Covering material 11: Extrusion die 13: Screw 15: Hoppa

Claims

1. A method for manufacturing a busbar, characterized by: applying a textured finish to the surface of a strip-shaped conductor made of copper, aluminum, or an alloy thereof by shot blasting to create irregularities on the surface; extruding a polyamide insulating resin onto the surface of the conductor without preheating the conductor; and then cutting the conductor.

2. A supply unit that supplies a strip-shaped conductor made of copper, aluminum, or an alloy thereof in one direction, The surface of the conductor is processed to create a textured surface by shot blasting, forming an uneven surface. An extrusion molding section is provided to the conductor after the textured finish, by extruding a polyamide insulating resin without preheating the conductor, thereby forming an insulating resin layer surrounding the surface of the conductor. A winding section for winding the conductor on which an insulating coating layer has been formed, A busbar manufacturing apparatus characterized by having the following features.

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