JP2893403B2 - Manufacturing method of bonding wire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention joins wire materials such as lead wires, cables, optical fiber cables and the like used in automobiles and other wire harnesses, electric products and wiring, and the like. FIELD OF THE INVENTION The present invention relates to a joining wire having a portion covered with a covering material and a method for producing the same. (Prior Art) For example, automotive wire harnesses include a main harness, a side harness, an engine sub-harness, a rear harness, a door harness, an instrument harness, and the like. Harnesses). For example, after removing the insulating coating of each wire to be joined to make it a bare wire, the bare wires are brought into contact with each other, and the wires are joined by using a metal bonding terminal, or directly into a hot state. It is connected by fusion welding. In order to prevent the occurrence of metal corrosion due to intrusion of water or salt damage into the joint portion and the occurrence of adverse effects such as poor electrical connection or disconnection, such a joint wire is used to prevent the joint portion and its vicinity from being damaged. Protected by covering material. As such a conventional bonding wire and a method for manufacturing the same, for example, there are the following. Using an insulating vinyl tape as a covering material, the insulating vinyl tape is wound around the joint. Using a thermoplastic resin as a covering material, a; molding by an extrusion molding method, and at the same time, solidifying in a connecting portion and sealing a joint portion. b; Form into a sheet and thermocompression bond to the joint. c; sealing is performed by injecting a heat-meltable resin into the container into which the joint is inserted. After using a heat-shrinkable tube as the covering material and passing the connecting portion through the heat-shrinkable tube, the tube is shrunk by applying a certain temperature from the outside of the tube. (Problems to be Solved by the Invention) However, the above-described bonding wire and the method for manufacturing the same have the following disadvantages. When the tape is wound around the joint portion of the joining wire rod, a gap is formed between the wraps of the tape unless the winding is first performed with a considerable tension applied thereto, resulting in poor sealing performance. Also,
If such an operation is performed manually, it takes time and productivity is low, and the winding operation requires skill. a; Since the equipment becomes large due to the necessity of an extrusion molding machine and the like, and the thermoplastic resin can be handled in a solid state only at a normal temperature, the process cannot be shifted to the next step until the temperature reaches the normal temperature. b; poor follow-up properties and poor adhesion to the joints, resulting in imperfect sealing and intrusion of water and the like. c; The joint is derailed or disconnected in the container in order to inject and solidify the heat-meltable resin while the joint is inserted into the container. Since the joining wire has to be passed through the tube, it is troublesome and workability is poor, and a gap is likely to occur, and after the both ends of the joining wire are connected to other members, it can not be passed through the tube. Coating is not possible. In addition, since none of the above-mentioned covering materials can be completely waterproofed, in order to prevent the occurrence of connection failure or disconnection due to water intrusion or salt damage at the joint of the joining wire, for example, in a vehicle interior, The harness is routed until the joint is inserted into the passenger compartment, but this requires time and effort for wiring the harness, and also makes the harness longer and heavier, as well as providing more space for the harness. And cost increases. (Means for Solving the Problems) In order to solve the above problems, the present invention relates to a method of manufacturing a bonded wire by joining a plurality of wires and covering the joint with a covering material. A thermoplastic resin layer is formed at the center of the plastic sheet except for the side edges, and is heated from above the thermoplastic resin layer to soften the thermoplastic resin and wrap the joints of the joining conductors. Further, the present invention relates to a method of manufacturing a joining wire in which an end of a plastic sheet is heated to melt-bond only the plastic sheet. In the present specification, the term "wire" is used to mean not only a wire such as a lead wire, an electric wire, a cable, and an optical fiber cable, but also a wire connecting a conductor and a connection terminal, and piping. “Joint” or “joint” is a term used to mean “joint” or “joint”. (Function) Since the covering material has an adhesive sealant layer on a plastic film, the plastic film is wrapped around and bonded to the outside with the adhesive sealant layer inside so that the covering material is bonded. The adhesive sealant follows the surface shape of the joining portion of the joining wire, so that the joining portion can be reliably sealed. In addition, by forming the covering material into a sheet shape, the connecting portion of the wire can be easily covered with a simple tool, and the joining portion of the joining wire can be covered even after the wire harness is assembled. Thereby, workability is improved. (Example) Hereinafter, an example of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view showing a joining wire according to a first embodiment of the present invention. The joining wire 1 is obtained by covering a joining portion of a joining wire 2 formed by joining a plurality of wires W1 to W4 with a coating material 3. As shown in FIG. 2, the joining conductor 2 is made into a bare wire state by removing each insulation coating of the four conductors W1 to W4, and then the bare wire portion of the conductor W1 and the bare wire portions of the conductors W2 to W4. Are joined to each other by soldering, using a joining terminal, or by direct fusion welding in a hot state, and the joining portion of the joining conducting wire 2 and its vicinity are covered with a covering material 3. Have been. In addition, as shown in FIG. 3 and FIG.
A thermoplastic resin layer (hereinafter, referred to as a “hot melt layer”) 5 as an adhesive sealant layer is partially formed on a plastic sheet 4. In addition, a foamed hot melt can be used as the hot melt. The plastic sheet 4 is a plastic sheet whose main component is a vinyl chloride-based or polyolefin-based resin.
As the plastic sheet 4, for example, a vinyl chloride resin sheet, a polyolefin resin sheet, a polyimide resin sheet, a polyamide resin sheet, a polyester resin sheet, or the like can be used. The thickness of the plastic sheet 4 is not particularly limited, but is, for example, about 0.05 to 5 mm. However, the thickness can also be changed according to the joint of the joint conductor 2. The hot melt layer 5 is made of, for example, a vinyl acetate resin such as Elvacs (trade name, manufactured by Toyo Soda Co., Ltd.), a polyamide resin, a polyolefin resin, an acrylic resin,
A resin mainly composed of a vinyl chloride resin, an ethylene vinyl acetate copolymer resin, a polyethylene resin, a polypropylene resin, a polybutadiene resin, a polyisoprene resin, and a polyimide resin can be used. Further, as these adhesive sealants, one kind may be used alone, or a mixture of two or more kinds may be used. Further, these adhesive sealants may contain various additives such as a plasticizer, a tackifier, and a stabilizer. The adhesive sealant used as the hot melt layer 5 has a softening temperature of 50 to 200C, preferably 80 to 180C. Further, by using a material having good adhesiveness with the plastic sheet as an adhesive sealant constituting the hot melt layer, a material having further excellent reinforcing properties can be obtained. Further, the thickness of the hot melt layer 5 is not particularly limited, but is, for example, about 40 μm to 3 mm. However,
The thickness can also be changed according to the joint of the joining conductor 2. Next, as a method for producing the coating material 3, for example, a method in which a hot melt liquefied by heating to a temperature equal to or higher than the melting point on the plastic sheet 4 is directly stretched to form a hot melt layer 5; The hot melt is poured into a mold to form a sheet, or the hot melt is formed into a sheet by a roll, and the hot melt is placed on a plastic sheet 4 and then heated to form a hot melt layer 5 integrated with the plastic sheet 4. And the like. In addition, in order to form the liquid hot melt layer 5 on the plastic sheet 4, for example, the liquid hot melt may be formed by injection molding, calendering, coating with a dispenser, or the like. Next, a method of manufacturing the joint wire 1 by covering the joint portion of the joint conductor 2 with the covering material 3 will be described. First, a hot melt or the like is applied to the coating material 3 having the hot melt layer 5 formed on the plastic sheet 4 shown in FIG. 3 from above the hot melt layer 5 to heat the coating material 3 for several seconds to several tens of seconds. As shown in FIG. 5, the surface 5a of the hot melt layer 5 of the coating material 3 is softened (melted), and the surface of the hot melt layer 5 becomes adhesive. Therefore, as shown in FIG. 6, the hot melt layer 5 adheres to the joint of the joining conductor 2 by wrapping the joint of the joining conductor 2 with the covering material 3 in this state, as shown in FIG. Thus, the joint of the joining conductor 2 is covered and protected by the covering material 3. As described above, since the surface of the hot melt layer 5 of the coating material 3 is softened, the hot melt layer 5 follows the unevenness of the joint of the joining conductor 2 and enters the gap, so that the joint is securely sealed. Further, since the hot melt layer 5 of the covering material 3 is in close contact with the joining portion of the joining conductor 2 and the surrounding insulating covering material to form an integral part with the insulating covering material, the sealing property, reinforcing property and covering function are improved. Furthermore, the coating operation can be performed only by preheating the coating material 3 for several seconds to several tens of seconds, for example, about 5 seconds to 10 seconds to soften the hot melt layer 5 and wrap the joint, thereby improving workability. Further, since the covering material 3 is in the form of a sheet, the same material can be used for a combination of bonding wires having different thicknesses or a plurality of wires. After wrapping the joint of the tangential conductors 2 with the covering material 3, as shown in FIG. 7, the end of the plastic sheet 4 of the covering material 3 is melted and bonded using a hot plate or the like. If
The strength is further increased, and the band-shaped coating material 3 can be used while being cut. In this case, the angle of the hot plate or the like may be fixed, but the finish is better if the angle is changed according to the thickness of the wire. The coating material 3 may be cut into an appropriate size before heating the hot melt layer 5, or may be cut into an appropriate size after heating the hot melt layer 5. Next, a specific example using the coating material 3 will be described. Example 1 (Coating material) A coating material was formed by coating a polyester hot melt material to a thickness of 0.8 mm on the following soft vinyl chloride sheet. Soft vinyl chloride sheet thickness: 0.5 mm Size: 50 mm x 40 mm Polyester hot melt material Trade name: Hardeck A-3200 (made by Asahi Kasei Co., Ltd.) Joining wire Using four 1.25 mm core wires, insulation coating of each of the four wires After removing the bare wires, the bare wire portions of one conductor and the bare wire portions of the three conductors are brought into contact with each other and joined by thermocompression bonding using ultrasonic waves to form a second conductor. The joining conductor as shown in the figure was formed. (Test) Tear tester (Tensilon manufactured by Toyo Baldwin Co., Ltd.)
RTM-1T; head speed 10 mm / min) was used to measure the tear strength. Specifically, as shown in FIG. 8, two of the three conductors are drawn in the direction of the arrow, measurement is started from the beginning of the drawing, and when each of the conductors is torn to the joint. End the measurement. Table 1 shows the measurement results. After covering the joints of the joining wires with the coating material, steam was applied at a temperature of 121 ° C. and a pressure of 2 atm by a pre-scraper tester, the sample was immersed for 30 hours under the test conditions, and Cu
It was confirmed whether or not the conductor had oxidative corrosion due to vapor permeation. In this case, the sealability was determined to be good when there was no oxidation corrosion, and the test results are shown in Table 1. Example 2 A coating material was formed by coating the following polyamide-based hot melt material with a thickness of 0.8 mm on the same soft vinyl chloride as in Example 1 to form a coating material. After covering the parts, the same test as in Example 1 was performed. Table 1 shows the test results. Polyamide-based hot-melt material trade name: Super-Stick 7802SS (DEXTER) Comparative Example 1 A 0.1 mm-thick vinyl chloride tape (NITTO TAPE, trade name, manufactured by Nitto Denko Corporation) at the joint of the same joint conductor as in Example 1.
Was wound 5 times and coated, and the same test as in Example 1 was performed. The test results are shown in Table 1. Comparative Example 2 The same test as in Example 1 was carried out by covering the joint portion of the same joint wire as in Example 1 with three turns of a 0.3 mm thick vinyl chloride tape. The test results are shown in Table 1. COMPARATIVE EXAMPLE 3 Using the same conductive wire as in Example 1, a bonding wire was formed by thermocompression bonding, and the bonding portion of this bonding wire was covered with only the same vinyl chloride sheet as in Example 1, and A similar test was performed. The test results are shown in Table 1. Comparative Example 4 Joint wire similar to that of Example 1 (however, joined by thermocompression bonding)
Was coated with only the same polyester hot melt material as in Example 1, and the same test as in Example 1 was conducted. The test results are shown in Table 1. In Example 1, when the tear strength was measured after 24 hours, a strength of 20 kgf or more was obtained. As can be seen from Table 1, by using the covering material 3 to cover the joint of the joining wire, the tear strength is remarkably improved. Next, an example of a method for producing the coating material 21 will be described. As shown in FIG. 9, a hot melt solution 32 obtained by diluting a hot melt resin with a solvent is placed in a container 31. A roller 33 made of polypropylene resin, polyacetal resin, fluorine resin, or the like is provided in the container 31, and a coater 34 is provided on the roller 33. Then, the plastic film 35 is conveyed while being sandwiched between the rollers 33 and the coater 34, the hot melt solution 32 is adhered to the surface of the plastic film 35, and then the hot melt solution 32 is formed by a fan 36 or the like. The stripped coating material sheet 37 is formed by volatilizing the solvent, and the strip-shaped coating material sheet 37 is wound by a roller 38 or the like.
At the time of use, the covering material sheet 37 is cut into a shape corresponding to the length and diameter of the connecting portion to form the sheet-like covering material 23. The method for manufacturing the coating material can be applied to the manufacturing of the coating material 3 in the first embodiment described above. (Effects of the Invention) As described above, according to the present invention, since the joint is covered with the covering material having the adhesive sealant layer on the plastic film, the adhesive sealant of the covering material is used for the joint of the joining wire. Following the surface shape, the joint can be reliably sealed,
Sealability, insulation, strength and weather resistance are improved. Thereby, the wire rods can be routed less and the weight can be reduced and the space can be effectively used. Further, since the covering material is in a sheet shape, the connecting portion of the wire can be easily covered with a simple jig and the joining portion of the joining wire can be covered even after assembling the wire harness. Workability is improved. Further, the coating operation is simple, the operation time is shortened, and the automation in the line can be achieved, thereby improving the productivity.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a joint portion of a joint wire according to a first embodiment of the present invention, FIG. 2 is a plan view showing the tangent conductor thereof,
3 and 4 are also a top view and a sectional view showing the covering material, FIG. 5 is a sectional view showing the state of the covering material after heating, and FIG. 6 is a joint using the covering material. FIG. 7 is a perspective view for explaining a method for manufacturing a wire rod, FIG. 7 is a perspective view for explaining another method for manufacturing a joint wire using the covering material, and FIG. 8 is a description of a test method for tear strength. FIG. 9 is an explanatory view similarly illustrating an example of a method of manufacturing the covering material. 1,21… Joint conductor, 2,22… Joint wire 3,23… Coating material, 4… Plastic sheet 5,25… Hot melt layer 24 …… Heat shrinkable sheet

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-57-82978 (JP, A) JP-A-51-147780 (JP, A) JP-A-63-51125 (JP, A) 161584 (JP, U) Japanese Utility Model Showa 59-1644447 (JP, U) Japanese Patent Publication No. 45-16148 (JP, B1) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01R 4/70, 4 / 72,43 / 00 H02G 15/18

Claims (1)

(57) [Claims] In a method of manufacturing a bonded wire by joining a plurality of wires and covering the joining portion with a covering material, the covering material forms a thermoplastic resin layer at a central portion of the plastic sheet except for side edges. Heating from above the thermoplastic resin layer to soften the thermoplastic resin, covering it by wrapping the joint of the joining conductor, and further heating the end of the plastic sheet to melt-bond only the plastic sheet What is claimed is: 1. A method for manufacturing a bonding wire. 2. 2. The method according to claim 1, wherein the plastic sheet is a soft vinyl chloride sheet. 3. The method according to claim 1, wherein the thermoplastic resin is selected from a polyester type and a polyamide type.