JP2016192387A - Wire with terminal, manufacturing method thereof, and wire harness - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wire with a terminal, a manufacturing method thereof, and a wire harness which enable improved water cut-off performance between the wire and the terminal while employing a very simple structure.SOLUTION: On a part of an outer peripheral surface 30 of a covering material 22, at a peeled end 24 of a covering member 22 or at a position adjacent thereto, one or a plurality of low friction areas 26, 27 of which friction coefficient is smaller than other areas are formed. On a part of an inner wall 48 of a crimping part 41, at a position on an open end 49 side of the crimping part 41 opposite to the low friction areas 26, 27, one or a plurality of roughed areas 53, 54 of which surface roughness is greater than other areas are formed.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a terminal-attached electric wire formed by crimping and connecting an electric wire and a terminal, a manufacturing method thereof, and a wire harness incorporating the terminal-attached electric wire.

  Conventionally, for example, a wire harness with a terminal having a connection structure in which a terminal is crimped to a wire is used for a wire harness mounted on a vehicle. In this type of electric wire with terminal, if a liquid containing moisture adheres to the connection part between the exposed wire and the inner wall of the terminal, oxidation of the surface of the connection part and its vicinity proceeds, and an increase in electrical resistance or corrosion occurs. May happen.

  Recently, in order to reduce the weight of the wire harness, for example, an electric wire with a terminal in which a wire made of an aluminum alloy and a terminal made of a copper alloy are combined has been developed. As described above, a highly waterproof connection structure using a closed barrel type terminal including a bottomed cylindrical crimping portion has been proposed as one form of a terminal-attached electric wire in which different types of metals contact each other (for example, patents). Reference 1).

JP 2014-164913 A

  By the way, according to the inventor's diligent study, when the closed barrel type terminal is caulked from two directions facing each other, the coating material of the electric wire is plastically deformed to a degree that cannot be ignored, and along the axial direction or the circumferential direction. Have been found to be stretched non-uniformly.

  FIG. 10A is a schematic diagram showing an original form of the covering material 2 provided in the electric wire 1 before crimping, and FIG. 10B is a schematic diagram showing a deformed state of the covering material 5 provided in the electric wire 4 after crimping. . For convenience of explanation, in FIG. 10B, illustration of a terminal crimped to the electric wire 4 is omitted.

  Grid lines 3 in FIG. 10 (a) are marks provided in advance on the covering material 2, and indicate positions on the outer peripheral surface before pressure bonding. As can be understood from the drawing, the regions surrounded by the vertical lines and the horizontal lines are rectangular shapes having the same area. On the other hand, as shown in FIG. 10B, the grid line 6 after crimping has a shape distorted in the axial direction and the circumferential direction as compared with the grid line 3.

  Thus, by crimping the terminal to the electric wire, a distribution is generated in the thickness of the coating material that was originally uniform. Due to this “thickness non-uniformity”, a single electric wire with a terminal coexists with a portion where the adhesion between the electric wire and the terminal is relatively high and a portion where the adhesion is low. Specifically, since the repulsive force (that is, the pressure-bonding force) applied to the terminal at a portion where the covering material is thin is reduced, this adhesiveness tends to be lowered.

  If it does so, a slight clearance gap will arise in the site | part where the adhesiveness of an electric wire and a terminal is relatively low, and the liquid from the outside may permeate into said connection site | part through this clearance gap. In particular, in the case of an electric wire whose covering material is thinned as a whole, there is a possibility that sufficient adhesion between the electric wire and the terminal cannot be ensured, and the concern of this intrusion becomes more apparent. In other words, this kind of electric wire with a terminal has a sufficient room for improvement from the viewpoint of water stopping.

  The present invention has been made in view of the above-described problems, and provides an electric wire with a terminal capable of improving the water stoppage between the electric wire and the terminal while adopting an extremely simple structure, a manufacturing method thereof, and a wire harness. With the goal.

  The “wire with terminal” according to the present invention includes a conductive wire and an insulating covering material that covers the wire, and an exposed portion is formed in which the tip end side of the wire is exposed by peeling of the covering material. An electric wire, and a bottomed cylindrical crimp portion, and at least the exposed portion inserted into the crimp portion and a terminal crimped to the electric wire, and a part of the outer peripheral surface of the covering material, One or a plurality of low friction areas having a smaller coefficient of friction than other areas are formed at the peeling edge of the covering material or at the periphery of the peeling edge. One or a plurality of roughened regions having a larger surface roughness than other regions are formed at a position on the opening end side of the crimping portion with respect to the low friction region.

  The covering material is subjected to compressive stress from the terminal side, and is plastically deformed integrally with the crimping portion. At this time, the crimping portion may be deformed while the peeling end of the covering material is involved depending on the shape of the inner wall surface or the contact state with the covering material. Further, since the electric wire has a step due to the presence or absence of the covering material, the covering material exhibits a behavior of escaping to the inside of the crimping portion (the space side where the step is formed). That is, the coating material around the peeling edge tends to be thin.

  Therefore, since the low friction region is provided at the peeling end of the outer peripheral surface or at the peripheral position, it becomes easy to slip in the low friction region and is hardly influenced by the deformation behavior of the crimping portion. Thus, it can suppress that a coating | coated material extends | stretches to a front-end | tip direction by said entrainment phenomenon.

  At the same time, the covering material is subjected to a compressive stress from the terminal side, so that it is pushed outward along the inner wall surface of the crimping portion and escapes to the outside of the crimping portion (base end side of the electric wire). That is, the covering material surrounded by the crimping portion tends to be thin overall. Then, since the roughening area | region was provided in the inner wall face of a crimping | compression-bonding part, a frictional force increases in the said roughening area | region, and the deformation | transformation behavior of a coating | coated part is suppressed. Thus, it can suppress that a coating material extends | stretches to a base end direction by said extrusion phenomenon.

  As described above, it is possible to simultaneously suppress the covering material from extending in the distal end direction and the proximal end direction, the unevenness of the thickness of the covering material is eliminated, and sufficient adhesion between the electric wire and the terminal can be ensured. . Thereby, the water stop between an electric wire and a terminal can be improved, adopting a very simple structure.

  Moreover, it is preferable that the roughening region is formed at a position separated from the low friction region. By disposing the roughened region and the low friction region in a positional relationship that does not interfere with each other, the respective stretching suppression functions can be effectively exhibited.

  The roughened region is preferably formed at a position around the opening end. Thereby, it can suppress that the coating | covering material in the wide range from a peeling end to the front of an opening end extends | stretches in a base end direction. Further, by removing the position of the opening end from the roughening region, it is possible to prevent the roughening region from acting as a liquid inlet.

  Moreover, it is preferable that one said roughening area | region and one said low friction area | region are formed on the same virtual line in the said outer peripheral surface extended along the axial center of the said electric wire. Since the action directions of the roughening area and the low friction area one by one coincide with each other, it is possible to prevent the distortion of the plastic deformation of the covering material due to the twist of the acting direction, and the uniform thickness of the covering material It becomes easy to ensure the property.

  The roughening region and the low friction region are each two, and the first roughening region and the first low friction region are formed on the first virtual line, and the second roughening region and the second low friction region are formed. Preferably, the friction region is formed on a second imaginary line different from the first imaginary line, and the first imaginary line and the second imaginary line are opposed to each other across the axis of the electric wire. Usually, since an external force is applied from two directions facing each other, the roughening region and the low friction region can be respectively arranged at positions close to the two action points.

  Moreover, it is preferable that the crimping | compression-bonding direction of the said terminal is parallel to the virtual plane which includes the said 1st virtual line and the said 2nd virtual line. Since an external force is applied from the two crimping directions facing each other, the roughening region and the low friction region can be respectively arranged at positions close to the two action points.

  Moreover, it is preferable that the inner wall surface is provided with an inclined region inclined with respect to the axis of the electric wire at a position around the peeling end. Since the inclined region is inclined with respect to the axis of the electric wire, there is a high possibility that the peeled end of the covering material is caught along the surface formed by the inclined region when the crimping portion is deformed. That is, the effect of suppressing the stretching when the low friction region is provided appears more remarkably.

  Further, the first imaginary line is present at a position where the inclination angle of the surface formed by the inclined region is relatively large, and the second imaginary line is a position where the inclination angle of the surface formed by the inclined region is relatively small. The width along the axial center direction of the electric wire in the first low friction region is preferably larger than the width of the second low friction region. Considering the tendency that the greater the inclination angle is, the greater the degree of entanglement of the peeling end is, and the coating material extends in the tip direction by making the surface formed by the low friction region on the side with the relatively large inclination angle more slippery. Can be more effectively suppressed.

  In addition, it is preferable that the first imaginary line is at a position where the inclination angle of the surface formed by the inclined region is maximized. By arranging the low friction region and the roughening region at the position where the inclination angle is maximized, the stretching of the covering material can be most effectively suppressed.

  Moreover, it is preferable that the width | variety along the axial center direction of the said electric wire in the said low friction area | region changes according to the outer diameter of the said electric wire. By appropriately setting the width of the low friction region, it is possible to obtain a stretching suppression effect suitable for the outer diameter of the electric wire.

  Moreover, it is preferable that the said low friction area | region is formed in the range which does not exceed 1/3 of the outer diameter of the said electric wire from the position of the said peeling end regarding the axial center direction of the said electric wire. By appropriately setting the range of the low friction region, it is possible to obtain a stretching suppression effect suitable for the outer diameter of the electric wire.

  Moreover, it is preferable that the said low friction area | region is formed in the range containing the said peeling end. By reducing the friction coefficient of the peeling end where the corner portion is formed by peeling, the possibility of the covering material being caught from the peeling end can be further reduced.

  The “method for producing a terminal-attached electric wire” according to the present invention includes an electrically conductive wire and an insulating covering that covers the wire, and an exposed portion where the tip end side of the wire is exposed by peeling of the covering. And a terminal-attached electric wire comprising a terminal having a bottomed cylindrical crimp portion, and at least the exposed portion inserted into the crimp portion and crimped and connected to the wire. A roughening step of forming one or a plurality of roughened regions having a surface roughness larger than that of other regions on a part of the inner wall surface of the crimped portion before forming the crimped portion into a bottomed cylindrical shape; A low-friction process for forming one or more low-friction regions having a small friction coefficient compared to other regions on a part of the outer peripheral surface of the covering material before the electric wire is crimped and connected, In the friction process, when the terminal is crimped and connected, the peeling end of the covering material or The low friction region is formed in a portion corresponding to the position around the peeling end, and in the roughening step, the roughening step is performed at the portion corresponding to the position on the opening end side of the crimping portion when the terminal is crimped and connected. Forming a control region.

  The “wire harness” according to the present invention is formed by bundling a plurality of the above-described electric wires with terminals.

  According to the terminal-attached electric wire, the manufacturing method thereof, and the wire harness according to the present invention, it is possible to improve the water stoppage between the electric wire and the terminal while adopting an extremely simple structure.

It is a perspective view of the electric wire with a terminal concerning this embodiment. It is a partial expanded longitudinal cross-sectional view of the electric wire with a terminal shown in FIG. It is sectional drawing along the axial center of the electric wire in the electric wire with a terminal shown in FIG. It is an expanded view of the coating | covering material which makes the outer peripheral surface of an electric wire. It is the schematic explaining the extending | stretching suppression effect by a low friction area | region and a roughening area | region. It is the schematic explaining an example of the extending | stretching model of a coating | covering material. It is a flowchart explaining the manufacturing method of the electric wire with a terminal shown in FIG. It is the schematic explaining the crimping | compression-bonding process of step S5. It is a perspective view of the wire harness incorporating the electric wire with a terminal shown in FIG. It is the schematic which shows the deformation | transformation state of the coating | covering material before and behind crimping | compression-bonding.

  DESCRIPTION OF EMBODIMENTS Hereinafter, a terminal-attached electric wire according to the present invention will be described with reference to the accompanying drawings by giving preferred embodiments in relation to the manufacturing method and the wire harness.

[Configuration of electric wire 10 with terminal]
<Overall configuration>
FIG. 1 is a perspective view of a terminal-attached electric wire 10 according to this embodiment. Specifically, FIG. 1A is an overall perspective view after the electric wire 20 and the terminal 40 are crimped and connected, and FIG. 1B is an exploded perspective view before the electric wire 20 and the terminal 40 are crimped and connected. .

  FIG. 2 is a partially enlarged longitudinal sectional view of the terminal-attached electric wire 10 shown in FIG. 1, and specifically shows the crimping shape of the crimping portion 41 that is crimped and connected to the electric wire 20.

  FIG. 3 is a cross-sectional view along the axis 25 of the electric wire 20 in the electric wire with terminal 10 shown in FIG. Specifically, FIG. 3A shows a cross-sectional shape of the terminal-attached electric wire 10 at a position corresponding to low friction regions 26 and 27 described later, and FIG. 3B corresponds to roughening regions 53 and 54 described later. The cross-sectional shape of the electric wire 10 with a terminal in a position is shown.

  As shown in FIGS. 1 and 2, the terminal-attached electric wire 10 basically includes an electric wire 20 and a terminal 40. The electric wire 20 includes a conductive wire 21 and an insulating covering material 22 that covers the wire 21.

  The wire 21 is a stranded wire formed by twisting a plurality of strands 21e. The strand 21e is made of a metal material made of, for example, aluminum, an aluminum alloy, copper, or a copper alloy. The form of the wire 21 is not limited to a stranded wire but may be a single wire.

  The covering material 22 may be of any material as long as it is a substance that insulates the wire 21 from the outside. The covering material 22 is made of, for example, an insulating resin including polyvinyl chloride (PVC) and cross-linked polyethylene.

  By exposing a part of the covering material 22, the electric wire 20 is formed with an exposed portion 23 a where the tip end side of the wire material 21 is exposed. In addition, the site | part except the exposed part 23a which comprises the electric wire 20, ie, the site | part which the coating | covering material 22 remains without peeling is called "covering part 23b." In addition, an end surface formed by peeling of the covering material 22, that is, a position of a boundary surface between the exposed portion 23a and the covering portion 23b is referred to as a “peeling end 24”.

  For convenience of explanation, the extending direction of the terminal 40 is defined as “X direction”, the crimping side of the terminal 40 is defined as “arrow X1 side”, and the non-crimping side of the terminal 40 is defined as “arrow X2 side”. The X direction will be described on the premise that the X direction coincides with the direction along the axis 25 of the electric wire 20 (hereinafter, the axis direction).

  Two low friction regions 26 and 27 are formed along the X direction on the outer peripheral surface formed by the electric wire 20, that is, on a part of the outer peripheral surface 30 of the covering material 22. Here, the “low friction region” means a region having a smaller friction coefficient than other regions in the range from the peeling end 24 to the opening end 49.

  “Friction coefficient” is, for example, a physical quantity defined in JIS K7125 (1999) when the measurement target is a resin film. That is, it can be said that the low friction regions 26 and 27 are regions in which at least one of the static friction coefficient (μs) and the dynamic friction coefficient (μd) is relatively large.

  As shown in FIG. 3A, the low friction regions 26 and 27 are obtained by applying a low friction process (here, application of a lubricant 29) on the outer peripheral surface 30 of the covering material 22. The lubricant 29 is made of, for example, silicon grease, fluorine grease, or grease using polyphenyl ether as a base oil. The low friction treatment includes a surface modification treatment in addition to the above-described coating treatment.

  Returning to FIG. 1, one adjustment mark 28 is further formed on the outer peripheral surface 30 of the covering material 22 in addition to the low friction regions 26 and 27. The adjustment mark 28 functions as an “orientation mark” for adjusting the circumferential direction (angle θ) of the electric wire 20 when the electric wire 20 is inserted into the crimping portion 41.

  The terminal 40 is a closed barrel type female crimp terminal, and has a substantially cylindrical crimp part 41 and a hollow square columnar box part 42. Between the crimping | crimped part 41 and the box part 42, the transition part 43 of the predetermined | prescribed length which connects both mechanically and electrically is located. The crimping part 41, the box part 42 and the transition part 43 constitute a terminal 40 integrally. The terminal 40 is made of a copper alloy strip such as brass whose surface is tin-plated (Sn-plated).

  The box part 42 receives insertion of an insertion tab provided in a male crimp terminal (not shown). The box portion 42 has a bottom surface portion 60, side surface portions 61 and 62, and an upper surface portion 63. The elastic contact piece 64 is formed by bending the bottom surface portion 60 inward toward the arrow X1 side, and contacts the above-described insertion tab when inserting the male crimp terminal.

  The crimping part 41 is a part for crimping the electric wire 20 into which at least the exposed part 23a is inserted. The crimping part 41 is formed in a continuous shape in the entire circumferential direction, specifically in a bottomed cylindrical shape. The crimping part 41 opens to the arrow X1 side, a bottom part 44 closed to the arrow X2 side, a first cylindrical part 45 to crimp the exposed part 23a, a second cylindrical part 46 to crimp the covering part 23b, and the arrow X1 side. An opening 47 is provided. An inner wall surface 48 that defines an internal space is formed inside the crimping portion 41.

  The bottom portion 44 is deformed so as to be crushed into a substantially flat plate shape on the arrow X2 side, and has a flat shape in which predetermined portions facing each other in the vertical direction overlap each other. A butting portion 50 extending along the X direction is provided from the bottom 44 to the position of the opening end 49.

  Since there is a level difference of about the thickness of the covering material 22 between the exposed portion 23a and the covering portion 23b, the first tubular portion 45 tends to be strongly compressed. Thereby, the transition part from the 1st cylindrical part 45 to the 2nd cylindrical part 46 becomes a shape where the 1st cylindrical part 45 was pushed in strongly. As will be described later, since the plastic deformation of the covering material 22 is suppressed, a space 51 (FIG. 2) remains around the peeling end 24.

  The inner wall surface 48 is provided with a region that is inclined with respect to the axis 25 of the electric wire 20 (hereinafter referred to as an inclined region 52) at a position around the peeling end 24. In the example of FIG. 2, the inclination angle of the surface formed by the inclined region 52 on the upper side of the crimping portion 41 is the largest, and the inclination angle of the surface formed by the inclined region 52 on the lower side of the crimping portion 41 is the smallest.

  Two roughened regions 53 and 54 are formed along the X direction in a part of the inner wall surface 48 formed by the crimping portion 41. Here, the “roughened region” means a region having a larger surface roughness than other regions in the range from the peeling end 24 to the opening end 49.

  “Surface roughness” is a physical quantity defined in JIS B 0601 (1994) and JIS B 0031 (1994). That is, the roughened regions 53 and 54 have an arithmetic average roughness (Ra), a maximum height (Ry), a ten-point average roughness (Rz), an average interval of unevenness (Sm), and an average interval (S) of local peaks. And at least one of the load length ratios (tp) can be said to be a relatively large region.

  As shown in FIG. 3B, the roughening regions 53 and 54 are subjected to a roughening process on the inner wall surface 48 of the crimping portion 41. This roughening process includes, for example, an electric discharge process, a blast process, and a laser processing process.

<External features of the covering material 22>
The two low friction regions 26 and 27 have the same shape, specifically, a rectangular shape in plan view, and are formed at positions that are line-symmetric with respect to the axis 25 of the electric wire 20.

  FIG. 4 is a development view of the covering material 22 that forms the outer peripheral surface 30 of the electric wire 20, and represents the position using a two-dimensional graph for convenience of explanation. The horizontal axis of the graph is the relative position X (unit: μm) in the axial direction with respect to the peeling end 24, the position of the peeling end 24 is 0 μm, and the arrow X1 side is the positive direction. The vertical axis of the graph is the angle θ (unit: degree) in the circumferential direction, the position of the butting portion 50 is 0 degree (360 degrees), and the clockwise direction when viewing the electric wire 20 from the arrow X2 side is the positive direction. To do.

  The low friction region 26 is separated from the peeling end 24 by a gap G1 [μm] (positive value or zero value), and is disposed at a position centered on θ = 0 degrees. The low friction region 26 has a width in the axial direction of Wa1 [μm] and a width in the circumferential direction of Wc1 [degree] (positive value). That is, the low friction region 26 exists in the range of G1 to (G1 + Wa1) [μm] in the axial direction and in the range of −0.5 · Wc1 to 0.5 · Wc1 [degrees] in the circumferential direction.

  The low friction region 27 is separated from the peeling end 24 by a gap G2 [μm] (positive value or zero value), and is disposed at a position centered on θ = 180 degrees. The low friction region 27 has a width in the axial direction of Wa2 [μm] and a width in the circumferential direction of Wc2 [degrees]. That is, the low friction region 27 is in the range of G2 to (G2 + Wa2) [μm] in the axial direction and in the range of (180−0.5 · Wc2) to (180 + 0.5 · Wc2) [degrees] in the circumferential direction. Exists.

  Each of the low friction regions 26 and 27 is formed at a position closer to the peeling end 24 than the opening end 49, that is, at a position around the peeling end 24 or the peeling end 24. The position of the peeling edge 24 means G1 (G2) = 0 μm, and the peripheral position means 0 <G1 (G2) ≦ 100 μm.

  Assuming that the distance between the peeling end 24 and the opening end 49 is L, θ = 0 degrees, X = L + ΔX [μm] (ΔX> 0), that is, a position closer to the arrow X1 than the opening end 49 A mark 28 is also formed.

  In the drawing, the projection positions of the two roughened regions 53 and 54 are also shown on the outer peripheral surface 30 of the covering material 22. The two roughened regions 53 and 54 have the same shape, specifically, a rectangular shape in plan view, and are formed at positions that are line-symmetric with respect to the axis 25 of the electric wire 20.

  The roughening region 53 is arranged around the opening end 49 (arrow X2 side) and at a position centered on θ = 0 degrees. Further, the roughened region 54 is arranged around the opening end 49 (arrow X2 side) and at a position centering on θ = 180 degrees. Specifically, each of the roughening regions 53 and 54 is separated from the opening end 49 by the gap G3 (> 0) [μm] on the arrow X2 side.

  The roughening region 53 and the low friction region 26 are arranged at positions separated from each other and on an imaginary line 56 (first imaginary line) extending along the X direction. Similarly, the roughened region 54 and the low friction region 27 are arranged at positions separated from each other and on an imaginary line 57 (second imaginary line) extending along the X direction. Here, the virtual lines 56 and 57 are in a positional relationship facing each other across the axis 25 of the electric wire 20.

  Note that the roughening regions 53 and 54 and the low friction regions 26 and 27 are all arranged so as not to straddle the other virtual lines 58 and 59. Another imaginary line 58 (third imaginary line) is at a position centered at θ = 90 degrees, and another imaginary line 59 (fourth imaginary line) is at a position centered at θ = 270 degrees. That is, the other virtual lines 58 and 59 correspond to center lines along the circumferential direction of the two virtual lines 56 and 57, respectively.

<Elongation suppression effect by the electric wire 10 with terminal>
The electric wire with terminal 10 according to this embodiment is configured as described above. Next, the effect of suppressing stretching by the low friction regions 26 and 27 and the roughening regions 53 and 54 will be described with reference to FIG. 5A shows a case where the low friction regions 26 and 27 and the roughening regions 53 and 54 do not exist, and FIG. 5B shows a case where the low friction regions 26 and 27 and the roughening regions 53 and 54 exist. Show.

  As shown in FIG. 5A, the covering material 22 is integrally deformed with the crimping portion 41 and plastically deformed by receiving a compressive stress from the terminal 40 side. At this time, the crimping part 41 may be deformed while the peeling end 24 is rolled in depending on the shape of the inclined region 52 or the like. Moreover, since the electric wire 20 has a level | step difference by the presence or absence of the coating | covering material 22, the coating | covering material 22 shows the behavior which escapes to the arrow X2 side (space 51 of FIG. 2). As a result, the covering material 22 around the peeling end 24 tends to be thin.

  At the same time, the covering material 22 is subjected to a compressive stress from the terminal 40 side, thereby being pushed out along the inner wall surface 48 of the crimping portion 41 and escaping to the arrow X1 side. That is, the covering material 22 surrounded by the crimping part 41 tends to be thin as a whole.

  As shown in FIG. 5 (b), by providing the low friction regions 26 and 27 at the peeling end 24 or its peripheral position, it becomes easy to slip in the low friction regions 26 and 27, and the crimping portion 41 is deformed. It becomes hard to be affected. Thus, it can suppress that the coating | covering material 22 extends | stretches to the arrow X2 side by the entrainment phenomenon shown to Fig.5 (a).

  Further, by providing the roughened regions 53 and 54 on the inner wall surface 48, the frictional force increases in the roughened regions 53 and 54, and the deformation behavior of the covering material 22 is suppressed. Thus, it can suppress that the coating | covering material 22 extends | stretches in the arrow X1 direction by the extrusion phenomenon shown to Fig.5 (a).

  The terminal-attached electric wire 10 according to this embodiment includes [1] a conductive wire 21 and an insulating covering material 22 that covers the wire 21, and the distal end side of the wire 21 is exposed by peeling of the covering material 22. The electric wire 20 in which the exposed part 23a is formed, and [2] a terminal 40 that has a bottomed cylindrical crimp part 41, and at least the exposed part 23a is inserted into the crimp part 41 and crimped to the electric wire 20 are provided.

  A part of the outer peripheral surface 30 of the covering material 22 has one or a plurality of low friction regions 26 and 27 having a small friction coefficient compared to other regions at the peeling edge 24 of the covering material 22 or a peripheral position thereof (here Then, two) are formed. Further, in a part of the inner wall surface 48 of the crimping portion 41, a roughened region having a larger surface roughness than the other regions at a position on the opening end 49 side of the crimping portion 41 with respect to the low friction regions 26 and 27. One or plural (here, two) 53 and 54 are formed.

  As described above, it is possible to simultaneously suppress the covering material 22 from extending toward the arrow X1 side and the arrow X2 side, the unevenness of the thickness of the covering material 22 is eliminated, and the adhesion between the electric wire 20 and the terminal 40 is eliminated. Can be secured sufficiently. Thereby, the water stop between the electric wire 20 and the terminal 40 can be improved while adopting an extremely simple structure.

<Extension model of covering material 22>
FIG. 6 is a schematic diagram illustrating an example of a stretching model of the covering material 22. Specifically, FIG. 6A is a graph showing the amount of displacement for each direction component, and FIG. 6B shows the amount of displacement obtained by combining the direction components. The horizontal axis of the graph is the same relative position X (unit: μm) as in FIG. 4, and the vertical axis of the graph is the displacement (unit: μm). The amount of displacement is such that the displacement toward the arrow X1 side is a positive direction and the displacement toward the arrow X2 side is a negative direction.

  In FIG. 6A, “Pa” is a function representing the amount of displacement of the covering material 22 due to the entrainment phenomenon in the form of FIG. 5A, and “Qa” is the form in the form of FIG. It is a function representing the amount of displacement of the covering material 22 due to the extrusion phenomenon. “Pb” is a function representing the displacement amount of the covering material 22 due to the entrainment phenomenon in the form of FIG. 5B, and “Qb” is attributable to the extrusion phenomenon in the form of FIG. It is a function representing the amount of displacement of the covering material 22.

  The functions Pa and Pb in this stretching model are Kp (X−x1) in the range of 0 ≦ X ≦ x1, and are always 0 in the range of X> x1. The functions Qa and Qb are Kq · X in the range of 0 ≦ X ≦ x2, and are always Kq · x2 in the range of X> x2. Note that the slopes Kp and Kq are both positive values. Here, it is assumed that the low friction regions 26 and 27 have an effect of reducing the value of the inclination Kp, and the roughening regions 53 and 54 have an effect of reducing the value of the inclination Kq.

  In FIG. 6B, “before countermeasure” is a function representing the amount of displacement of the covering material 22 in the form of FIG. 5A and corresponds to the sum of functions (Pa + Qa). Further, “after countermeasure” is a function representing the amount of displacement of the covering material 22 in the form of FIG. 5B, and corresponds to the sum of functions (Pb + Qb). As can be understood from this figure, the absolute value of the displacement amount after “measures” is small over almost the entire range of the position X as compared with “before measures”.

  In addition, R1 shown to Fig.6 (a) is corresponded to the range of the X direction which can exhibit the extending | stretching suppression function by the low friction area | regions 26 and 27 effectively. R2 corresponds to a range in the X direction in which the stretching suppressing function by the roughened regions 53 and 54 can be effectively exhibited. In other words, it is preferable to arrange the low friction regions 26 and 27 so as to be within the range R1 and the roughening regions 53 and 54 within the range R2.

<Arrangement and shape of low friction regions 26 and 27 and roughening regions 53 and 54>
Returning to FIG. 4, the roughened region 53 (54) may be formed at a position separated from the low friction region 26 (27). By arranging the roughened region 53 (54) and the low friction region 26 (27) under a positional relationship that does not interfere with each other, the respective stretching suppression functions can be effectively exhibited.

  Further, the roughened regions 53 and 54 may be formed at positions around the opening end 49. Thereby, it can suppress that the coating | covering material 22 in the wide range from the peeling end 24 to the front of the opening end 49 extends to the arrow X1 side. Further, by excluding the position of the opening end 49 from the roughening regions 53 and 54, it is possible to prevent the roughening regions 53 and 54 from acting as a liquid inlet.

  Further, one roughening region 53 (54) and one low friction region 26 (27) extend on the same virtual line 56 (57) on the outer peripheral surface 30 extending along the axis 25 of the electric wire 20. It may be formed. Since the action directions of the roughening regions 53 (54) and the low friction regions 26 (27) one by one coincide with each other, it is possible to prevent the distortion of the plastic deformation of the covering material 22 due to the twist of the action direction. It is easy to ensure the uniformity of the thickness of the covering material 22.

  Further, the roughening regions 53 and 54 and the low friction regions 26 and 27 are two, respectively, and the virtual lines 56 and 57 may be opposed to each other with the axis 25 of the electric wire 20 in between. Usually, since external force is applied from two directions facing each other, the roughening regions 53 and 54 and the low friction regions 26 and 27 can be respectively arranged at positions close to the two action points.

  The crimping direction P1 of the terminal 40 may be parallel to a virtual plane 72 (FIG. 8) that includes the virtual lines 56 and 57. Since an external force is applied from the two crimping directions P1 facing each other, the roughening regions 53 and 54 and the low friction regions 26 and 27 can be arranged at positions close to the two action points, respectively.

  In addition, an inclined region 52 that is inclined with respect to the axis 25 of the electric wire 20 may be provided on the inner wall surface 48 at a position around the peeling end 24. Since the inclined region 52 is inclined with respect to the shaft center 25, when the crimping portion 41 is deformed, the possibility that the peeling end 24 of the covering material 22 is caught along the surface formed by the inclined region 52 is increased. That is, the effect of suppressing stretching when the low friction regions 26 and 27 are provided appears more remarkably.

  Further, the imaginary line 56 exists at a position where the inclination angle of the surface formed by the inclined region 52 is relatively large (θ = 0 degrees), and the imaginary line 57 has a relative inclination angle of the surface formed by the inclined region 52. The width (Wa1) along the X direction in the low friction region 26 that exists at a small position (θ = 180 degrees) may be larger than the width (Wa2) of the low friction region 27. Considering the tendency that the greater the inclination angle is, the greater the degree of engulfment of the peeling end 24 is. By making the surface formed by the low friction region 26 on the side where the inclination angle is relatively larger, the covering material 22 becomes the arrow X2. It can suppress more effectively extending to the side.

  Further, the virtual line 56 may be at a position (θ = 0 degree) at which the inclination angle of the surface formed by the inclined region 52 is maximized. By arranging the low friction region 26 and the roughening region 53 at a position where the inclination angle is maximized, the stretching of the covering material 22 can be most effectively suppressed.

  The low friction regions 26 and 27 may be formed in a range including the peeling end 24. By reducing the friction coefficient of the peeling end 24 in which the corner portion is formed by peeling, the possibility that the covering material 22 is caught from the peeling end 24 can be further reduced.

<Method for producing electric wire 10 with terminal>
Then, the manufacturing method of the above-mentioned electric wire 10 with a terminal is demonstrated in detail, referring the flowchart of FIG. 7, and FIG.

  In the “roughening step”, which is Step S <b> 1 in FIG. 7, roughening regions 53 and 54 are formed in a portion corresponding to the inner wall surface 48 of the terminal 40. Specifically, a known roughening process including an electric discharge process, a blast process, and a laser processing process is performed on a predetermined position of the metal plate before processing.

  The discharge process includes not only plasma discharge and corona discharge but also a process that uses any one of the discharge principles of spark discharge, glow discharge, and arc discharge. Blasting means various processes for spraying an abrasive, and includes a pneumatic method such as sand blasting, a mechanical method such as shot blasting, and a wet method such as wet blasting that jets a liquid mixed with abrasive grains.

  For example, in the case of laser processing, an irregular shape is imparted to the surface by sweeping and irradiating a laser beam with a solid laser containing YAG. By this roughening step, a roughened region 53 having a relatively large surface roughness and a rectangular shape in plan view is formed as compared with other portions. By the same procedure, another roughened region 54 is formed.

  The roughening regions 53 and 54 are preferably formed at positions that fall within the range R2 in FIG. Thereby, at the time of the crimping | compression-bonding connection (step S5) of the terminal 40, it can suppress effectively that the coating | covering material 22 extends | stretches to the arrow X1 side by an extrusion phenomenon.

  In the “forming process” which is Step S2 in FIG. 7, the terminal 40 is formed by processing the metal plate on which the roughened regions 53 and 54 are formed in Step S1. Specifically, a metal plate punched into a predetermined shape is bent into a cylindrical shape, and end portions are welded using a fiber laser or the like to form a butt portion 50. Thereafter, the bottom portion 44 is formed by crushing the skirt portion of the abutting portion 50, and welding and sealing are performed so as to close the portion. Thereby, the terminal 40 provided with the bottomed cylindrical crimp part 41 is formed.

  In the “application process” which is Step S3 in FIG. 7, two low friction regions 26 and 27 are formed by applying a lubricant 29 such as silicon grease on the outer peripheral surface 30 of the covering material 22. Prior to application, the tip end side of the covering material 22 is peeled off by a predetermined length, thereby producing the electric wire 20 in which the exposed portion 23a is formed. Further, by performing known marking processing including printing, heat treatment, and laser processing on the covering material 22, the adjustment mark 28 is formed at a predetermined position on the outer peripheral surface 30.

  The low friction regions 26 and 27 are preferably formed at positions that fall within the range R1 in FIG. Thereby, at the time of the crimping | compression-bonding connection (step S5) of the terminal 40, it can suppress effectively that the coating | covering material 22 extends | stretches to the arrow X2 side by an entrainment phenomenon.

  For example, the widths (Wa1, Wa2) along the X direction in the low friction regions 26 and 27 may be varied according to the outer diameter of the electric wire 20. By appropriately setting the widths of the low friction regions 26 and 27, it is possible to obtain a stretching suppression effect suitable for the outer diameter of the electric wire 20.

  In addition to or separately from this, the low friction regions 26 and 27 may be provided in a range in the X direction from the position of the peeling end 24 and not exceeding 1/3 of the outer diameter of the electric wire 20. By appropriately setting the ranges of the low friction regions 26 and 27, it is possible to obtain a stretching suppression effect suitable for the outer diameter of the electric wire 20.

  In the “insertion step”, which is step S4 in FIG. 7, the electric wire 20 in which the low friction regions 26 and 27 are formed in step S3 is inserted into the terminal 40 in a predetermined direction by a predetermined length. Specifically, after the exposed portion 23a of the electric wire 20 is brought close to the opening 47 of the terminal 40, it is confirmed whether or not the adjustment mark 28 formed on the covering material 22 is in the correct position. Here, it is confirmed whether or not the circumferential position (angle θ) between the adjustment mark 28 of the electric wire 20 and the butted portion 50 of the terminal 40 matches.

  When both positions do not match, after rotating the electric wire 20 in a direction to reduce the difference between the two, it is reconfirmed whether or not the positions match. On the other hand, when both positions coincide, the exposed portion 23a of the electric wire 20 is inserted from the opening 47 of the terminal 40 while maintaining the positional relationship.

  Even when the positions of the low friction regions 26 and 27 cannot be visually recognized from the outside of the crimping portion 41 when the electric wire 20 is inserted, the electric wire 20 can be guided in the correct direction by using the position of the adjustment mark 28 as a clue. .

  The adjustment mark 28 also functions as a positioning mark for adjusting the insertion amount of the electric wire 20. Specifically, the insertion amount may be determined according to the position (relative position X) in the axial direction between the adjustment mark 28 and the opening end 49.

  In the “crimping step”, which is step S5 in FIG. 7, the electric wire 20 inserted in step S4 is crimped. Hereinafter, this will be described in detail with reference to FIG.

  As shown in FIG. 8, the electric wire 20 and the terminal 40 before crimping connection are set in the crimping die 70, and the crimping die 71 above the crimping die 70 is lowered. Then, the crimping | compression-bonding part 41 of the terminal 40 is crimped from the crimping | compression-bonding direction P1, and the electric wire 20 and the terminal 40 are crimp-connected. Here, the crimping direction P <b> 1 is substantially parallel to the virtual plane 72 that includes the two virtual lines 56 and 57, and is substantially orthogonal to another virtual plane 73 that includes the two virtual lines 58 and 59. In this case, the crimping force becomes maximum at the circumferential position (θ = 0 degrees, 180 degrees) corresponding to the crimping direction P1, and the circumferential position (θ = 90 degrees, 270 degrees) corresponding to the side direction P2. ) Minimizes the crimping force.

  Thus, manufacture of the electric wire 10 with a terminal is complete | finished by step S1-S5. According to this manufacturing method, before the crimping portion 41 is formed into a bottomed cylindrical shape, roughened regions 53 and 54 having a larger surface roughness than other regions are formed on a part of the inner wall surface 48 of the crimping portion 41. One or a plurality of roughening steps (step S1) and before the terminal 40 is crimped and connected, a part of the outer peripheral surface 30 of the covering material 22 has a low friction region 26 having a smaller friction coefficient than other regions, A step of reducing friction (step S4) for forming one or a plurality of 27.

  In the roughening step (S1), roughened regions 53 and 54 are formed at portions corresponding to the peeled end 24 of the covering material 22 or its peripheral position when the terminal 40 is crimped and connected. Further, in the low friction process (S4), the low friction regions 26 and 27 are formed in the portion corresponding to the opening end 49 of the crimping portion 41 or the peripheral position when the terminal 40 is crimped and connected. Thereby, the electric wire 10 with a terminal which has the above-mentioned effect can be manufactured.

<Pressing direction P1 of terminal 40>
By the way, the method to grasp | ascertain the crimping | compression-bonding direction P1 (refer FIG. 8) of the terminal 40 is demonstrated.

[1] The most reliable means is to witness the crimping step (step S5 in FIG. 7). Instead of this, as shown below, the crimping direction P1 may be estimated by analyzing the electric wire with terminal 10 after manufacture.

[2] Depending on the shape of the crimping part 41, the crimping direction P1 may be estimated. For example, when the metal plate is bent into a cylindrical shape and the ends are welded together, the crimping direction P <b> 1 can be estimated from the position of the butting portion 50.

[3] The crimping direction P1 can be estimated from the cross-sectional shape of the electric wire 20. This is because the cross-sectional shape of the electric wire 20 is anisotropically deformed through the crimping process of the electric wire 20 and the terminal 40. Specifically, the crimping direction P <b> 1 corresponds to a direction in which the thickness of the electric wire 20 is a minimum value among the angular directions passing through the axis 25. For example, when the cross-sectional shape of the electric wire 20 is an ellipse, it can be estimated that the crimping direction P1 is the minor axis direction.

[4] The crimping direction P <b> 1 can be estimated from the occurrence of burrs in the crimping portion 41. This is because the crimping portion 41 undergoes plastic deformation along the boundary surface between the pair of crimping dies 70 and 71 (FIG. 8) through the crimping process of the electric wire 20 and the terminal 40. Specifically, the crimping direction P1 corresponds to the normal direction of another virtual plane 73 that includes two burrs. Note that a place where the burr is polished may be used instead of the place where the burr is generated.

<Application example>
Then, the application example of this electric wire 10 with a terminal is demonstrated. FIG. 9 is a perspective view of a wire harness 100 incorporating the terminal-attached electric wire 10 shown in FIG.

  The wire harness 100 includes connection structures 104A, 104B, 104C, which are constituted by electric wires with terminals 10, 10, 10,... And connectors 102, 102, 102,. ‥‥have. The wire harness 100 is an assembled electric wire in which each connection structure 104A (B, C,...) Is combined with a member (not shown) and bundled with a winding tape 106, and then an aggregate connector 108 is disposed at an end thereof. is there.

  As described above, the wire harness 100 capable of achieving both weight reduction and high water-stopping property can be obtained by bundling a plurality of the electric wires 10 with terminals. For example, if this wire harness 100 is mounted on a vehicle, the vehicle can be significantly reduced in weight and fuel efficiency can be improved.

[Remarks]
In addition, this invention is not limited to embodiment mentioned above, Of course, it can change freely in the range which does not deviate from the main point of this invention.

  In this embodiment, the number of the low friction regions 26 and 27 is two, but the number is not limited to this, and may be one or three or more. Further, the shapes, positions, and sizes of the low friction regions 26 and 27 may be freely changed within a range in which the above-described stretching suppression function can be exhibited.

  In this embodiment, the number of roughening regions 53 and 54 is two, but is not limited thereto, and may be one or three or more. Further, the shapes, positions, and sizes of the roughened regions 53 and 54 may be freely changed within a range in which the above-described stretching suppression function can be exhibited.

DESCRIPTION OF SYMBOLS 10 ... Electric wire with a terminal 20 ... Electric wire 21 ... Wire material 22 ... Coating | covering material 23a ... Exposed part 23b ... Covering part 24 ... Stripping end 25 ... Shaft center 26, 27 ... Low friction area 28 ... Adjustment mark 29 ... Lubricant 30 ... Outer periphery Surface 40 ··· Terminal 41 ··· Crimping portion 44 ··· Bottom portion 45 ··· First cylindrical portion 46 ··· Second cylindrical portion 47 ··· Opening portion 48 · · · Inner wall surface 49 · · · Open end 50 · Butting portion 52 · Inclined regions 53 and 54 · Rough Area 56 ... Virtual line (first virtual line)
57. Virtual line (second virtual line) 58, 59 Another virtual line 72 Virtual plane 73 Another virtual plane 100 Wire harness

Claims (14)

An electric wire having an electrically conductive wire and an insulating covering that covers the wire, and an exposed portion in which the leading end side of the wire is exposed by peeling of the covering; and
A terminal-attached electric wire comprising: a bottomed cylindrical crimping portion; and at least the exposed portion inserted into the crimping portion, and a terminal crimped and connected to the wire,
One or more low friction regions having a smaller coefficient of friction than other regions are formed on a part of the outer peripheral surface of the covering material at a position around the peeling end of the covering material or around the peeling end,
One or a plurality of roughened regions having a larger surface roughness than other regions are formed in a part of the inner wall surface of the crimping portion at a position on the opening end side of the crimping portion with respect to the low friction region. An electric wire with a terminal, characterized in that   The said roughening area | region is formed in the position spaced apart from the said low friction area | region, The electric wire with a terminal of Claim 1 characterized by the above-mentioned.   The electric wire with a terminal according to claim 1, wherein the roughened region is formed at a position around the opening end.   One said roughening area | region and one said low friction area | region are formed on the same virtual line in the said outer peripheral surface extended along the axial center of the said electric wire. The electric wire with a terminal given in any 1 paragraph of above. The roughening area and the low friction area are each two.
The first roughened region and the first low friction region are formed on the first imaginary line,
The second roughened region and the second low friction region are formed on a second imaginary line different from the first imaginary line,
The electric wire with a terminal according to claim 4, wherein the first imaginary line and the second imaginary line are opposed to each other across an axis of the electric wire.   The electric wire with a terminal according to claim 5, wherein a crimping direction of the terminal is parallel to a virtual plane including the first virtual line and the second virtual line.   The electric wire with a terminal according to claim 5 or 6, wherein an inclined region inclined with respect to the axis of the electric wire is provided on the inner wall surface at a position around the peeling end. The first imaginary line is at a position where the inclination angle of the surface formed by the inclined region is relatively large,
The second imaginary line is at a position where the inclination angle of the surface formed by the inclined region is relatively small,
The electric wire with a terminal according to claim 7, wherein a width along the axial center direction of the electric wire in the first low friction region is larger than a width of the second low friction region.   The electric wire with a terminal according to claim 7 or 8, wherein the first imaginary line is at a position where the inclination angle of the surface formed by the inclined region is maximized.   The electric wire with a terminal according to any one of claims 1 to 9, wherein a width along an axial center direction of the electric wire in the low friction region varies depending on an outer diameter of the electric wire.   The said low friction area | region is formed in the range which does not exceed 1/3 of the outer diameter of the said electric wire from the position of the said peeling end regarding the axial center direction of the said electric wire. The electric wire with a terminal of Claim 1.   The said low friction area | region is formed in the range containing the said peeling end, The electric wire with a terminal of any one of Claims 1-11 characterized by the above-mentioned. An electric wire having an electrically conductive wire and an insulating covering that covers the wire, and an exposed portion in which the leading end side of the wire is exposed by peeling of the covering; and
A method of manufacturing a terminal-attached electric wire comprising: a bottomed cylindrical crimp portion; and at least the exposed portion inserted into the crimp portion and a terminal crimped to the wire.
Before forming the crimped portion into a bottomed cylindrical shape, a roughening step of forming one or a plurality of roughened regions having a larger surface roughness than other regions on a part of the inner wall surface of the crimped portion;
A low friction step of forming one or a plurality of low friction regions having a small friction coefficient compared to other regions on a part of the outer peripheral surface of the covering material before crimping the wire;
In the low friction step, the low friction region is formed in a portion corresponding to a peeling end of the covering material or a position around the peeling end when the terminal is crimped and connected,
In the roughening step, the roughening region is formed in a portion corresponding to the position on the opening end side of the crimping portion when the terminal is crimped. The method for producing a terminal-attached electric wire.   A wire harness comprising a plurality of electric wires with terminals according to any one of claims 1 to 12.

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