JP2017183154A - Manufacturing method of electric wire with heat-shrinkable tubing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique for easily improving a water cut-off performance of a heat-shrinkable tubing.SOLUTION: In an electric wire with a terminal 10, an exposure core wire part 14a exposed to one end of an electric wire 12 includes a connection part 11 jointed to a support surface 200S of a plate-like terminal 20. The electric wire with the terminal is inserted 10 to a heat-shrinkable tubing 30B. In the heat-shrinkable tubing 30B, a thermoplastic adhesive layer 32L is formed on an inner peripheral surface, and an expansion part 320 of a thermoplastic adhesive agent in which a base end part 322 is communicated to the thermoplastic adhesive layer 32L is formed. The heat-shrinkable tubing 30B is heated and contracted in a state where the expansion part 320 is distributed on the side of the support surface 200S of the terminal 20.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method for manufacturing an electric wire with a heat-shrinkable tube.

  Generally, a wire harness mounted on a vehicle such as an automobile has a terminal including a core wire and an insulated wire having an insulation coating surrounding the core wire, and a terminal connected to the core wire exposed at one end of the insulated wire. It has electric wires.

  In a terminal-attached electric wire, a heat-shrinkable tube may be attached to a connection portion between the core wire of the electric wire and the terminal for the purpose of waterproofing and corrosion prevention. In particular, when the core wire of an insulated wire is an aluminum wire in a terminal-attached electric wire, it is effective to seal the connection portion with a heat-shrinkable tube because the connection portion between the core wire and the crimp terminal is easily corroded by different metal contact corrosion. It is.

  Generally, a thermoplastic adhesive layer is provided on the inner peripheral surface of the heat shrinkable tube. When the heat shrinkable tube is heated, the heat shrinkable tube shrinks and the thermoplastic adhesive melts. To do. The melted thermoplastic adhesive is solidified to fill a gap between the terminal-attached electric wire and the heat-shrinkable tube (for example, Patent Document 1).

JP 2011-29102 A

  By the way, when the thermoplastic adhesive in the heat-shrinkable tube is insufficient, an auxiliary material formed of the plastic adhesive is placed in the insufficient part, and heat treatment may be performed. However, when using a supplement, depending on the shortage, it may be difficult to place the supplement appropriately at the target position. For this reason, in the heat-shrinkable tube after shrinkage | contraction, water stoppage might not be able to be secured enough.

  An object of this invention is to provide the technique which improves the water stop property of a heat contraction tube easily.

  In order to solve the above-mentioned problem, a first aspect is a method for manufacturing a wire with a heat-shrinkable tube in which a heat-shrinkable tube is attached to a connection portion between a terminal and a wire in a wire with a terminal, and (a) A core wire exposed at one end, a step of preparing a terminal-attached electric wire having a connecting portion joined to one main surface of a plate-like terminal, and (b) a layer of a thermoplastic adhesive is formed on the inner peripheral surface, And the step of covering the connecting portion with the heat shrinkable tube through one end of the terminal-attached electric wire through the heat shrinkable tube having the unevenly distributed portion formed by uneven distribution of the thermoplastic adhesive in a part of the circumferential direction; (c) after the step (b), heating and shrinking the heat shrinkable tube.

  Moreover, a 2nd aspect is a manufacturing method of the electric wire with a heat contraction tube of a 1st aspect, Comprising: In the said (c) process, the said uneven distribution part is distribute | arranged to the said one main surface side of the said terminal. Heating the heat-shrinkable tube in a state.

  Further, a third aspect is a method for manufacturing an electric wire with a heat-shrinkable tube according to the first or second aspect, wherein the unevenly distributed portion has a base end side connected to the thermoplastic adhesive layer and a tip end side of the electric wire with the heat shrink tube. It includes an overhanging portion protruding outward in the axial direction of the heat shrinkable tube.

  Moreover, a 4th aspect is a manufacturing method of the electric wire with a heat contraction tube of a 3rd aspect, Comprising: The said (c) process includes the process of bending the said overhang | projection part inside.

  Moreover, a 5th aspect is a manufacturing method of the electric wire with a heat contraction tube of a 4th aspect, Comprising: The said overhang | projection part has a part which becomes wide as it goes to a front end side from a base end part.

  According to the manufacturing method of the electric wire with a heat shrinkable tube of the first aspect, since the unevenly distributed portion of the thermoplastic adhesive is integrated with the heat shrinkable tube, the unevenly distributed portion matches the region where the thermoplastic adhesive is insufficient. By positioning the electric wire with the heat-shrinkable tube, the region can be supplemented with the thermoplastic adhesive. For this reason, the water-stopping property of the heat shrinkable tube can be easily improved.

  According to the second aspect of the method for manufacturing the electric wire with a heat-shrinkable tube, the unevenly distributed portion of the thermoplastic adhesive is heated in a state facing the one main surface to which the core wire in the terminal is connected. The surface side can be replenished with thermoplastic adhesive. Thereby, sealing of the connection part of the terminal and core wire in the one main surface side becomes easy.

  Moreover, according to the manufacturing method of the electric wire with a heat contraction tube of the 3rd aspect, a thermoplastic adhesive can be replenished to the one end vicinity in which the overhang | projection part in the heat contraction tube was formed. For this reason, since the inner side of one end vicinity of a heat-shrinkable tube can be appropriately filled with a thermoplastic adhesive, water-stopping can be improved. Moreover, since the overhang | projection part has protruded the outer side of the heat contraction tube, when a heat contraction tube is heated, an overhang | projection part can be fuse | melted easily.

  Moreover, according to the manufacturing method of the electric wire with a heat-shrinkable tube according to the fourth aspect, the vicinity of the opening on the one end side of the heat-shrinkable tube can be filled with the thermoplastic adhesive by bending the protruding portion inward. It becomes easy.

  Moreover, according to the manufacturing method of the electric wire with a heat contraction tube of a 5th aspect, the bending of an overhang | projection part becomes easy by making the width | variety of an overhang | projection part gradually large toward a front end side from a base end part.

It is a figure showing electric wire 100 with a heat contraction tube concerning a 1st embodiment. It is a schematic perspective view which shows the heat-shrinkable tube 30 before shrinkage | contraction of 1st Embodiment. It is a schematic perspective view of the electric wire 10 with a terminal of 1st Embodiment. It is a schematic perspective view of the principal part of the electric wire 10 with a terminal inserted in the heat-shrinkable tube 30B before shrinkage. It is a schematic perspective view of the principal part of the electric wire 10 with a terminal inserted in the heat-shrinkable tube 30B before shrinkage. It is a schematic front view of the heat-shrinkable tube 30B before shrinkage | contraction of 2nd Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, the component described in this embodiment is an illustration to the last, and is not a thing of the meaning which limits the scope of the present invention only to them. In the drawings, the size and number of each part may be exaggerated or simplified as necessary for easy understanding.

<1. First Embodiment>
Drawing 1 is a figure showing electric wire 100 with a heat contraction tube concerning a 1st embodiment. The heat-shrinkable tube-equipped electric wire 100 includes the terminal-attached electric wire 10 and the heat-shrinkable tube 30. The electric wire with terminal 10 includes an electric wire 12 and a terminal 20.

<Wire>
The electric wire 12 includes a core wire portion 14 and a covering portion 16 formed around the core wire portion 14. The core wire portion 14 is formed in a linear shape from a conductive material such as copper, copper alloy, aluminum, or aluminum alloy. Here, the core wire portion 14 has a configuration in which a plurality of strands are twisted together. But the core wire part may be comprised by the single wire. The covering portion 16 is formed by extruding the insulating resin material around the core wire portion 14 by an extrusion device or the like. The core wire portion 14 is exposed at the distal end portion of the electric wire 12, and an exposed core wire portion 14a having a predetermined length is formed.

<Terminal>
In the terminal 20, a copper alloy base material such as copper or brass was plated with tin (Sn) or tin alloy in which silver (Ag), copper (Cu), bismuth (Bi) or the like was added to tin. It may be a metal plate. The terminal 20 is a member formed by, for example, pressing a metal plate material.

  The terminal 20 includes a contact portion 21, an intermediate portion 23, a core wire connection portion 25, and a covering connection portion 27.

  The contact portion 21 is a portion that is directly connected to a connection partner. Here, the contact portion 21 is a flat plate portion, and a through-hole 211 through which a fixing tool (screw or the like) for fixing to a connection partner is passed is formed in the center portion thereof.

  The intermediate portion 23 is a flat plate portion that is continuous with the core wire connecting portion 25 and the contact portion 21. The intermediate part 23 in the present embodiment has a flat plate shape. The portion near at least the intermediate portion 23 in the core wire connecting portion 25 is also flat. In this embodiment, the whole core wire connection part 25 is flat form. In the following description, a flat plate-like portion extending from the core wire connection portion 25 to the intermediate portion 23 in the terminal 20 is referred to as a core wire support portion 200. Further, the surface (main surface) on the core wire portion 14 side in the core wire support portion 200 is referred to as a support surface 200S.

  The core wire connecting portion 25 is a portion that electrically connects the terminal 20 to the exposed core wire portion 14a. In the terminal-attached electric wire 10, the core wire connection portion 25 is the connection portion 11 at which the exposed core wire portion 14 a is joined to the support surface 200 </ b> S (one main surface) of the terminal 20.

  The core wire connecting portion 25 has a pair of crimping pieces that are crimped to the exposed core wire portion 14a. In addition, it is not essential that the terminal 20 is connected to the exposed core part 14a via a pair of crimping pieces. For example, the terminal 20 may be connected to the exposed core portion 14a by ultrasonic welding, resistance welding, soldering, or the like.

  The covering connection portion 27 is a portion that connects the terminal 20 to the covering portion 16 of the electric wire 12. Here, the covering connection portion 27 includes a pair of crimping pieces, and the terminal 20 is connected to the covering portion 16 by the pair of crimping pieces being crimped to the covering portion 16 of the electric wire 12.

<Heat shrinkable tube>
The heat-shrinkable tube-equipped electric wire 100 has a water stop structure that prevents liquid from entering in order to prevent corrosion of the core wire portion 14. The water stop structure in the electric wire 100 with the heat shrinkable tube includes the heat shrinkable tube 30.

  In the electric wire 100 with a heat-shrinkable tube, it is conceivable that the core wire portion 14 and the terminal 20 of the electric wire 12 are made of different metals. For example, it is conceivable that the core wire portion 14 is an aluminum wire, that is, a wire (aluminum or aluminum alloy) containing aluminum as a main component. On the other hand, the terminal 20 is plated with a tin alloy in which silver (Ag), copper (Cu), bismuth (Bi) or the like is added to tin (Sn) or tin on a copper alloy base material such as copper or brass. It is conceivable that the member has been made. In this case, the exposed core portion 14a that comes into contact with the terminal 20 is likely to corrode when a liquid serving as an electrolyte enters. In such a case, it is effective to attach the heat shrinkable tube 30 in order to suppress the intrusion of the liquid into the core wire connecting portion 25.

  The heat-shrinkable tube 30 covers at least the core wire connection portion 25 that is the connection portion 11 of the terminal-attached electric wire 10, and here, the region including the core wire connection portion 25 and the covering connection portion 27 from the tip of the exposed core wire portion 14 a. cover.

  FIG. 2 is a schematic perspective view showing the heat-shrinkable tube 30 before shrinking according to the first embodiment. As shown in FIG. 2, a thermoplastic adhesive layer 32L, which is a thermoplastic adhesive layer, is formed on the inner peripheral surface of the heat-shrinkable tube 30 (hereinafter referred to as heat-shrinkable tube 30B) before shrinkage. ing. The thermoplastic adhesive is a resin material that is solid at normal temperature and melts by heating, and specifically, a modified olefin-based or polyester-based hot-melt adhesive.

  The thermoplastic adhesive layer 32L is formed on the entire inner peripheral surface of the heat-shrinkable tube 30B. Here, the thermoplastic adhesive layer 32L has a uniform thickness in the circumferential direction of the heat-shrinkable tube 30B. Further, the heat shrinkable tube 30B is formed with an overhang portion 320 formed of a thermoplastic adhesive. The projecting portion 320 is a projecting portion whose base end portion 322 is continuous with a part in the circumferential direction of the thermoplastic adhesive layer 32 </ b> L and projecting outward in the axial direction of the heat shrinkable tube 30. The heat-shrinkable tube 30B on which the thermoplastic adhesive layer 32L and the overhang portion 320 are formed is manufactured by, for example, two-color molding. The overhang portion 320 is an example of an unevenly distributed portion formed by uneven distribution of a thermoplastic adhesive in a part of the heat shrinkable tube 30 in the circumferential direction.

  The overhanging portion 320 has the smallest width at the base end portion 322 and is formed in a plate shape whose width increases from the base end portion 322 toward the tip end portion 324. Here, the overhang portion 320 is formed in a substantially semicircular plate shape. In addition, the shape of the overhang | projection part 320 is not limited to this, For example, you may form in the shape of a square plate.

<Manufacturing method>
FIG. 3 is a schematic perspective view of the terminal-attached electric wire 10 according to the first embodiment. 4 and 5 are schematic perspective views of a main part of the terminal-attached electric wire 10 inserted into the heat-shrinkable tube 30B before shrinkage. In FIG. 3, the heat-shrinkable tube 30B is indicated by a two-dot chain line.

  First, as shown in FIG. 3, the terminal-attached electric wire 10 having the connection portion 11 in which the exposed core wire portion 14 a exposed at one end of the electric wire 12 is joined to the support surface 200 </ b> S of the plate-like terminal 20 via the core wire connection portion 25. Is prepared (wire preparation process with terminals).

  Subsequently, as shown in FIGS. 3 and 4, the end portion of the terminal-attached electric wire 10 is passed through the heat-shrinkable tube 30, and the connection portion 11 of the terminal-attached electric wire 10 is the heat-shrinkable tube 30. Covered (insertion process). At this time, one end of the heat-shrinkable tube 30B on the side where the overhang portion 320 is formed is arranged closer to the contact portion 21 than the exposed core portion 14a.

  Subsequently, as illustrated in FIG. 5, when the operator pushes the distal end portion of the overhang portion 320 with the fingertip F <b> 1, the overhang portion 320 is bent inward from the base end portion 322 (bending step). At this time, the overhang portion 320 is arranged on the side where the exposed core portion 14a of the terminal 20 is joined, that is, on the side of the support surface 200S. For this reason, as shown in FIG. 5, the side where the exposed core portion 14 a of the terminal 20 is joined is partially closed in the opening 30 </ b> P at one end of the heat shrinkable tube 30 by bending the overhang portion 320 inward. Is done. Further, in order to seal the tip side portion of the core wire portion 14a, it is conceivable that the protruding portion 320 is bent so as to contact the tip portion of the exposed core wire portion 14a. Note that this bending step may be omitted as appropriate.

  Subsequently, the heat-shrinkable tube 30, the thermoplastic adhesive layer 32L, and the overhanging portion 320 are heated by a heating device (not shown) (heating step). As a result, the heat-shrinkable tube 30 contracts as much as possible according to the outer shape of the connecting portion 11. Further, the thermoplastic adhesive layer 32L and the overhanging portion 320 are melted by heat. And the electric wire 100 with a heat-shrinkable tube 100 by which the space between the heat-shrinkable tube 30 and the connection part 11 was filled with the melted and solidified material of the thermoplastic adhesive layer 32L and the overhang | projection part 320 is obtained by being cooled to normal temperature.

  Further, in order to prevent the hot melt of the overhanging portion 320 from protruding from one end of the heat-shrinkable tube 30 after shrinking, the width of the overhanging portion 320 is made smaller than the width of the heat-shrinkable tube 30B. Can be considered.

  Moreover, although it can be considered that the thickness of the overhanging portion 320 is substantially the same as the thickness of the thermoplastic adhesive layer 32L, it is not limited to this. Further, it is not essential that the thickness of the overhang portion 320 is uniform. For example, the overhanging portion 320 can be easily bent by making the portion near the base end portion 322 relatively thin. Further, in the overhang portion 320, the intermediate portion between the base end portion 322 and the tip end portion 324, or the tip end portion 324 is made relatively thick so as to ensure bendability and the volume of the overhang portion 320. Can be increased.

<Effect>
In the case of the heat-shrinkable tube 30B, an overhang portion 320 that is an unevenly distributed portion of the thermoplastic adhesive is integrated with the heat-shrinkable tube 30B. For this reason, by positioning the heat-shrinkable tube 30B so that the unevenly distributed portion is close to a region where the thermoplastic adhesive can be insufficient, the thermoplastic adhesive can be easily supplemented to the insufficient region. When the heat-shrinkable tube 30B is heated, the thermoplastic adhesive layer 32L inside the heat-shrinkable tube 30B and the protruding portion 320 are fused, so that the inside of the heat-shrinkable tube 30 can be sealed with good reproducibility.

  Further, the heat shrinkable tube 30B is heated in a state where the overhanging portion 320 that is an unevenly distributed portion is disposed on the side of the supporting surface 200S to which the exposed core wire portion 14a of the terminal 20 is connected, thereby supporting the terminal 20. A thermoplastic adhesive can be replenished to the surface 200S side. Thereby, sealing of the connection part 11 becomes easy.

  Moreover, a thermoplastic adhesive can be replenished to the one end vicinity in which the overhang | projection part 320 in the heat contraction tube 30B was formed. For this reason, since the inside of the heat shrinkable tube 30 near one end can be appropriately filled with the thermoplastic adhesive, the waterstop property of the heat shrinkable tube 30 can be increased. In addition, since the overhang portion 320 overhangs outside the heat shrinkable tube 30B, the overhang portion 320 can be easily melted when the heat shrinkable tube 30B is heated.

  Further, by gradually increasing the width of the overhang portion 320 from the base end portion 322 toward the distal end portion 324 side, the overhang portion 320 can be easily bent. Further, the capacity can be increased by widening the width.

  Further, by bending the overhanging portion 320 inward by the bending process, it becomes easy to fill the vicinity of the opening 30P on one end side of the heat shrinkable tube 30 with the thermoplastic adhesive.

<2. Second Embodiment>
Next, a second embodiment will be described. In the following description, elements having the same functions as the elements already described may be denoted by the same reference numerals or reference numerals added with alphabetic characters, and detailed description may be omitted.

  FIG. 6 is a schematic front view of the heat-shrinkable tube 30B before shrinkage according to the second embodiment. A thermoplastic adhesive layer 32La is formed on the inner peripheral surface of the heat-shrinkable tube 30B of the present embodiment. The thermoplastic adhesive layer 32La has a thick portion 320a formed by uneven distribution of the thermoplastic adhesive in a part of the heat shrinkable tube 30B in the circumferential direction. That is, the thick part 320a corresponds to an unevenly distributed part. The thickness L2 including the thick part 320a of the thermoplastic adhesive layer 32La is larger than the thickness L1 of the other part (for example, the part opposite to the thick part 320a).

  By using the heat-shrinkable tube 30B on which the thick part 320a of the thermoplastic adhesive layer 32La is formed, the thermoplastic adhesive can be easily applied to a region where the thermoplastic adhesive may be insufficient. Can be replenished. In particular, as shown in FIG. 6, the heat-shrinkable tube 30 </ b> B is heated with the thick portion 320 a facing the support surface 200 </ b> S side of the terminal 20, so that the thermoplastic adhesive is applied to the support surface 200 </ b> S side of the terminal 20. Can be replenished.

<3. Modification>
Although the embodiment has been described above, the present invention is not limited to the above, and various modifications are possible.

  For example, in the above embodiment, the overhanging portion 320 and the thick portion 320a, which are unevenly distributed portions of the thermoplastic adhesive, are provided at one place in the circumferential direction of the heat shrinkable tube 30B. However, the unevenly distributed portions may be provided in a distributed manner at a plurality of locations in the circumferential direction of the heat shrinkable tube 30B. Dispersing the unevenly distributed portion at a plurality of locations facilitates thermal melting.

  Further, the overhanging portion 320 may be provided not only on one end side of the heat-shrinkable tube 30B but also on the opposite other end side. Furthermore, you may provide both the overhang | projection part 320 and the thick part 320a in the heat contraction tube 30B.

  Although the present invention has been described in detail, the above description is illustrative in all aspects, and the present invention is not limited thereto. It is understood that countless variations that are not illustrated can be envisaged without departing from the scope of the present invention. In addition, the configurations described in the above embodiments and modifications can be appropriately combined or omitted as long as they do not contradict each other.

DESCRIPTION OF SYMBOLS 100 Electric wire with heat shrinkable tube 10 Electric wire with terminal 11 Connection part 12 Electric wire 14 Core wire part 14a Exposed core wire part 16 Covering part 20 Terminal 25 Core wire connection part 30 Heat shrinkable tube 30B Heat shrinkable tube 30P before shrinkage 32L, 32La Thermoplastic adhesion Agent layer 200 Core wire support 200S Support surface (one main surface)
320 Overhang (uneven portion)
322 Base end portion 324 Tip end portion 320a Thick portion (unevenly distributed portion)

Claims (5)

A method for producing a heat-shrinkable tube-attached electric wire in which a heat-shrinkable tube is attached to a connection portion between the terminal and the electric wire in the electric wire with terminal,
(a) a step of preparing a terminal-attached electric wire having a connecting portion where the core wire exposed at one end of the electric wire is joined to one main surface of the plate-like terminal;
(b) The terminal is connected to the heat-shrinkable tube having an unevenly distributed portion formed by forming a thermoplastic adhesive layer on the inner peripheral surface and unevenly distributing the thermoplastic adhesive in a part of the circumferential direction. Covering the connection portion with the heat-shrinkable tube through one end of the attached wire;
(c) after the step (b), heating and shrinking the heat-shrinkable tube; and
A method for manufacturing an electric wire with a heat-shrinkable tube. It is a manufacturing method of the electric wire with a heat contraction tube of Claim 1,
Step (c) is a step of heating the heat-shrinkable tube in a state where the unevenly distributed portion is disposed on the one main surface side of the terminal.
Manufacturing method of electric wire with heat shrinkable tube. It is a manufacturing method of the electric wire with a heat contraction tube of Claim 1 or Claim 2,
The unevenly distributed portion is a method of manufacturing an electric wire with a heat-shrinkable tube, wherein a proximal end side is connected to the thermoplastic adhesive layer and a distal end side includes an overhanging portion protruding outward in the axial direction of the heat-shrinkable tube. It is a manufacturing method of the electric wire with a heat contraction tube of Claim 3,
The step (c)
The manufacturing method of the electric wire with a heat contraction tube including the process of bending the said overhang | projection part inside. It is a manufacturing method of the electric wire with a heat contraction tube of Claim 4,
The manufacturing method of the electric wire with a heat contraction tube which has a part from which the said overhang | projection part becomes large as it goes to a front end side from a base end part.

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