JP2023154337A - Crimping device, manufacturing method of terminal-equipped wire, and terminal-equipped wire - Google Patents

Abstract

To provide a crimping device capable of appropriately crimping a crimping piece of a terminal fitting to a conductor core wire of an electric wire.SOLUTION: A crimping device 4 includes a first processing tool 70 having an arcuate surface 76 for crimping a caulking piece 42 to a conductor core wire 11 while guiding the caulking piece 42 so as to cover the conductor core wire 11 of an electric wire 10, and a second processing tool 100 having a facing surface 101 facing the arcuate surface 76, and is configured such that a terminal fitting 20 is sandwiched between the arcuate surface 76 and the facing surface 101 to perform a crimping process. The arcuate surface 76 includes a rear curved surface 76b that guides a tip end portion 42a of the caulking piece 42 to be inserted into the conductor core wire 11, and a front curved surface 76a that guides the caulking piece 42 toward a rear curved surface 76b. The degree of curvature of the rear curved surface 76b in the cross section of the first processing tool 70 is smaller than the degree of curvature of the front curved surface 76a in the cross section.SELECTED DRAWING: Figure 3

Description

The present invention relates to a crimping device for crimping a caulking piece of a terminal to a conductor core wire of an electric wire, a method of manufacturing an electric wire with a terminal, and an electric wire with a terminal.

Conventionally, terminal fittings that are crimped and crimped onto electric wires have been proposed. This type of terminal fitting typically includes a placing part on which the electric wire is placed, a conductor clamping part which is clamped to the conductor core wire of the electric wire, and a covering clamping part which is clamped to the insulation coating of the electric wire. has. Then, after placing the wire on the placement part, use the processing tools (so-called anvil and crimper) provided in the crimping device to surround and crimp the conductor core wire and insulation sheath. The above-described crimping is performed by deforming the tightening portion (see, for example, Patent Document 1).

Japanese Patent Application Publication No. 2018-073584

By the way, when the terminal fitting is crimped to the electric wire as described above, the conductor crimping part of the terminal fitting slides along the arcuate surface provided on the processing tool (in particular, the crimper) and surrounds the conductor core wire. The conductor core wire is gradually deformed, and finally it is crimped so that it comes into close contact with the conductor core wire. Here, from the viewpoint of improving the reliability of the electrical connection between the conductor core wire and the terminal fitting, it is generally recommended that the conductor It is desirable that the caulking portion is crimped to the conductor core wire. By inserting the tip between the strands in this way, the contact area between the conductor core wire and the conductor crimping part becomes large, and the conductor crimping part is prevented from unintentionally separating from the conductor core wire after crimping. This is because it is suppressed.

However, for example, if the degree of curvature of the arcuate surface of the processing tool is excessively larger than the degree of curvature at which the desired crimping described above is achieved, the deformation of the conductor crimping portion may become excessive. In this case, as shown in Figure 9, the tip of the conductor crimping part may not be fully inserted between the strands of the conductor core wire, and may hit the outer peripheral surface of the conductor core wire and become folded back. be. On the other hand, if the degree of curvature of the arcuate surface of the processing tool is excessively smaller than the degree of curvature at which the desired crimping described above is achieved, the deformation of the conductor crimping portion will be too small, and the conductor core wire may be surrounded by the conductor crimping portion. itself can be difficult. Generally, the degree of curvature of the arcuate surface is empirically set to an appropriate degree so as to reduce the incidence of such defects. However, it is desirable to further reduce the incidence of such defects and further increase the productivity of electric wires with terminals.

One of the objects of the present invention is to provide a crimping device, a method for manufacturing an electric wire with a terminal, and an electric wire with a terminal, which are capable of appropriately crimping a caulking piece of a terminal fitting to a conductor core wire of an electric wire. .

In order to achieve the above-mentioned object, the "crimping device" according to the present invention has the following features.

A crimping device for crimping a caulking piece of a terminal fitting to a conductor core wire of an electric wire, the crimping device comprising:
a first processing tool having an arcuate surface for crimping the crimping piece to the conductor core wire while guiding the crimping piece so as to cover the conductor core wire;
a second processing tool having an opposing surface facing the arcuate surface,
configured to perform a crimping process by sandwiching the terminal fitting between the arcuate surface and the opposing surface in a predetermined processing direction,
The arcuate surface is
It has a rear curved surface that guides the tip of the caulking piece to be inserted into the conductor core wire, and a front curved surface that guides the caulking piece toward the rear curved surface,
The degree of curvature of the rear curved surface in the cross section of the first processing tool along the processing direction is smaller than the degree of curvature of the front curved surface in the cross section.
Must be a crimping device.

Furthermore, in order to achieve the above-mentioned object, the "method for manufacturing an electric wire with a terminal" according to the present invention has the following features.

A method for manufacturing an electric wire with a terminal for manufacturing an electric wire with a terminal in which a caulking piece of a terminal fitting is crimped onto a conductor core wire of the electric wire, the method comprising:
an arrangement step of arranging the conductor core wire and the caulking piece between an arcuate surface of a first processing tool and an opposing surface of a second processing tool;
a crimping step of sandwiching the conductor core wire and the crimping piece between the arcuate surface and the opposing surface in a predetermined processing direction, and crimping the crimping piece to the conductor core wire so as to cover the conductor core wire. ,
The arcuate surface of the first processing tool is
a rear curved surface that guides the tip of the crimping piece to be inserted into the conductor core wire in the crimping step, and a front curved surface that guides the crimping piece toward the rear curved surface,
The degree of curvature of the rear curved surface in the cross section of the first processing tool along the processing direction is smaller than the degree of curvature of the front curved surface in the cross section.
It must be a manufacturing method for electric wires with terminals.

Furthermore, in order to achieve the above-mentioned object, the "electric wire with terminal" according to the present invention has the following features.

An electric wire with a terminal, comprising an electric wire and a terminal fitting having a caulking piece that is crimped to a conductor core wire of the electric wire,
The caulking piece of the terminal fitting is
With the tip of the crimping piece inserted into the conductor core wire, the crimping piece is crimped to the conductor core so as to cover the conductor core, and from the tip to the base end of the crimping piece. has an arcuate portion extending toward
The outer surface of the arcuate portion is
a distal end side curved surface adjacent to the distal end portion, and a proximal side curved surface located between the distal side curved surface and the proximal end portion,
The degree of curvature of the distal side curved surface in a cross section perpendicular to the axis of the electric wire is smaller than the degree of curvature of the proximal side curved surface in the cross section,
Must be an electric wire with a terminal.

According to the crimping device of the present invention, the first processing tool (for example, a crimper) has an arcuate surface that guides the crimping piece of the terminal fitting, and the second processing tool (for example, an anvil) has an opposing surface facing the arcuate surface. The crimping process is performed using the and, so that the terminal fitting is sandwiched between the arcuate surface and the opposing surface. The arcuate surface of the first processing tool has a front curved surface and a rear curved surface having different degrees of curvature. Specifically, the degree of curvature of the rear curved surface is smaller than the degree of curvature of the front curved surface. When the crimping process is performed, the crimping piece of the terminal fitting is guided through the front curved surface toward the rear curved surface, and is guided by the rear curved surface so as to be inserted into the conductor core wire. According to the inventor's considerations, the degree of curvature of the rear curved surface is smaller than the degree of curvature of the front curved surface, resulting in a problem in which the tip of the caulking piece hits the outer peripheral surface of the conductor core wire and is folded back. It has been shown that this can be suppressed. As this principle, for example, the following can be considered.

That is, as illustrated in FIGS. 5 to 7, when the crimping process is performed, the tip of the caulking piece is guided to the front curved surface so that it has the same degree of curvature as the front curved surface. (i.e., curved). After that, when the tip of the caulking piece that has passed through the front curved surface reaches the rear curved surface, the degree of curvature of the rear curved surface is smaller than the degree of curvature of the front curved surface (that is, the rear curved surface is closer to being flat). The tip portion, which has been deformed (curved) in advance by the front curved surface, is difficult to be pressed against (or is slightly separated from) the surface of the rear curved surface. As a result, even if elastic recovery occurs at the tip due to so-called springback, compared to when the degree of curvature of the front curved surface and the rear curved surface is the same, or when the degree of curvature of the rear curved surface is greater than the degree of curvature of the front curved surface. While the crimping piece is being guided by the rear curved surface, the external force exerted on the tip of the crimping piece from the rear curved surface can be reduced. It is thought that the above principle makes it difficult to cause a problem in which the tip end of the caulking piece hits the outer peripheral surface of the conductor core wire and is folded back due to excessive deformation (curving) of the tip end of the caulking piece.

As described above, the crimping device having the present configuration is capable of appropriately crimping the caulking piece of the terminal fitting to the conductor core wire of the electric wire.

Note that the above-mentioned cross section of the first processing tool "along the processing direction" can be rephrased as a cross section of the first processing tool perpendicular to the axis of the electric wire, for example. Furthermore, the magnitude of the above-mentioned "degree of curvature" is determined when, for example, the front curved surface and the rear curved surface have a shape that corresponds to an arc of a perfect circle (that is, a part of the circumference of a perfect circle having a predetermined radius) in the cross section. If so, it can be determined based on the size of the radius of the perfect circle. Specifically, it can be determined that the smaller the radius of the perfect circle, the greater the degree of curvature. On the other hand, if the front curved surface does not have a shape corresponding to the arc of a perfect circle in the cross section (for example, if it has a curve shape different from a perfect circle), for example, the curvature at multiple points on the front curve (i.e., The determination can be made based on the average value of the reciprocal of the radius of curvature at each of the plurality of points. Specifically, it can be determined that the larger the average value, the greater the degree of curvature. The same applies to the subsequent curved surface.

Furthermore, according to the method of manufacturing an electric wire with a terminal of the present invention, a first processing tool (for example, a crimper) having an arcuate surface that guides the crimping piece of the terminal fitting, and a second processing tool having an opposing surface facing the arcuate surface are provided. A crimping process is performed using a tool (for example, an anvil) so that the terminal fitting is sandwiched between the arcuate surface and the opposing surface. The arcuate surface of the first processing tool has a front curved surface and a rear curved surface having different degrees of curvature. Specifically, the degree of curvature of the rear curved surface is smaller than the degree of curvature of the front curved surface. When the crimping process is performed, the crimping piece of the terminal fitting is guided through the front curved surface toward the rear curved surface, and is guided by the rear curved surface so as to be inserted into the conductor core wire. According to the inventor's considerations, the degree of curvature of the rear curved surface is smaller than the degree of curvature of the front curved surface, resulting in a problem in which the tip of the caulking piece hits the outer peripheral surface of the conductor core wire and is folded back. It has been shown that this can be suppressed. An example of this principle is as described above. Therefore, according to the manufacturing method of this configuration, it is possible to manufacture an electric wire with a terminal in which the caulking piece of the terminal fitting is properly crimped onto the conductor core wire of the electric wire.

Furthermore, according to the electric wire with a terminal of the present invention, the crimping piece is crimped so as to cover the conductor core wire with the tip of the crimping piece of the terminal fitting being inserted into the conductor core wire of the electric wire. Therefore, compared to the case where the tip of the crimping piece is not inserted into the conductor core wire, the contact area between the conductor core wire and the crimping piece is expanded, and the crimping piece may unintentionally separate from the conductor core wire after crimping. things are suppressed. Therefore, the electric wire with a terminal of this configuration can improve the reliability of the electrical connection between the conductor core wire and the terminal fitting.

The present invention has been briefly described above. Further, details of the present invention will become clearer by reading the detailed description described below with reference to the accompanying drawings.

FIG. 1 is a perspective view showing a state before a conductor crimping part and a covering crimping part of a terminal fitting are crimped onto an electric wire using a crimping apparatus according to an embodiment of the present invention. FIG. 2 is a sectional view taken along line AA in FIG. FIG. 3 is an enlarged view of section B in FIG. 2. FIG. 4 is a sectional view taken along line CC in FIG. FIG. 5 is a diagram corresponding to the DD cross section in FIG. 4 for explaining the first process in which the deformation of the conductor crimping piece progresses due to crimping. FIG. 6 is a diagram corresponding to FIG. 5 for explaining a second process in which the deformation of the conductor crimping piece progresses due to crimping. FIG. 7 is a diagram corresponding to FIG. 5 for explaining the third process in which the deformation of the conductor crimping piece progresses due to crimping. FIG. 8 is a diagram corresponding to the DD cross section in FIG. 4, showing a state in which the tip end of the conductor crimping piece is properly inserted into the conductor core wire. FIG. 9 is a diagram corresponding to FIG. 8 showing a state in which a problem occurs in which the tip of the conductor crimping piece hits the outer peripheral surface of the conductor core wire and is folded back.

<Embodiment>
Hereinafter, a method for manufacturing a terminal-equipped electric wire 1 according to an embodiment of the present invention using a crimping device 4 according to an embodiment of the present invention will be described with reference to FIGS. 1 to 9. As shown in FIGS. 1 and 4, the electric wire 1 with a terminal is formed by crimping a terminal fitting 20 to the end of the electric wire 10 using a crimping device 4. In the electric wire 1 with a terminal, the electric wire 10 and the terminal fitting 20 are electrically connected. As shown in FIGS. 1 and 4, the crimping device 4 includes an anvil 2 and a crimper 3.

Hereinafter, for convenience of explanation, "front-back direction", "horizontal direction", and "up-down direction" will be defined as shown in FIGS. 1 to 9. The "front-back direction", the "left-right direction", and the "up-down direction" are orthogonal to each other. The front-rear direction corresponds to the extending direction of the electric wire 1 with a terminal (more specifically, the terminal fitting 20), and the front side and the rear side correspond to the distal end side and the proximal end side of the terminal fitting 20, respectively. Hereinafter, first, each member constituting the terminal-equipped electric wire 1 will be explained in order.

First, the electric wire 10 will be explained. As shown in FIGS. 1 and 4, the electric wire 10 includes a conductor core wire 11 and an insulating coating 12 that covers the outer periphery of the conductor core wire 11. In this example, the conductor core wire 11 is an aggregate of a plurality of wires. Each strand is made of a conductive metal such as copper or aluminum. The insulation coating 12 is made of resin having insulation properties. In preparation for crimping the terminal fitting 20 onto the electric wire 10, the insulating coating 12 is removed at the tip of the electric wire 10 to expose a predetermined length of the conductor core wire 11.

A later-described conductor crimping portion 40 (see FIG. 1, etc.) of the terminal fitting 20 will be crimped to a predetermined location on the exposed conductor core wire 11 on the rear side of the terminal portion 11a (see FIG. 1, etc.) later. . A later-described sheath crimping portion 60 (see FIG. 1, etc.) of the terminal fitting 20 will be crimped to the end portion of the insulating sheath 12 of the electric wire 10.

Next, the terminal fitting 20 will be explained. In this example, the terminal fitting 20 is formed by plating a metal plate material as a base material to cover the entire surface with a plating layer, and then subjecting it to processing such as pressing and bending. Note that the terminal fitting 20 may be formed by performing processing such as press working and bending on a metal plate material, and then performing a plating process to cover the entire surface with a plating layer. Typically, a plate made of copper (Cu) or a copper (Cu) alloy is used as the metal plate. As the plating layer, a tin (Sn) plating layer is typically used.

As shown in FIGS. 1 and 4, the terminal fitting 20 includes a terminal connecting portion 30 with a mating terminal, a connecting portion 35, a conductor crimping portion 40, an intermediate portion 50, and a covering crimping portion 60. The terminal connecting portion 30, the connecting portion 35, the conductor crimping portion 40, the intermediate portion 50, and the cover crimping portion 60 are arranged in a line in this order along the front-rear direction from the front side to the rear side. In this example, the explanation will be continued using the terminal metal fitting 20 having the terminal connection part 30 as a typical example, but the present invention can also be applied to terminals having other shapes such as relay terminals for connecting two electric wires. is applicable. Hereinafter, for convenience of explanation, regarding the plate-shaped conductor crimping part 40 and the covering crimping part 60, the surface on the side that contacts the electric wire 10 will be referred to as the "inner surface", and the surface on the opposite side to the side that contacts the electric wire 10 will be referred to as the "inner surface". It is called the "outer surface."

The terminal connecting portion 30 is a portion of the terminal fitting 20 that is connected to a mating terminal, and in the example shown in FIG. 1, has a rectangular cylindrical shape extending in the front-rear direction. A spring piece 31 is provided inside the terminal connection section 30 to make elastic contact with a mating terminal inserted into the terminal connection section 30 (see FIG. 1). The terminal connecting portion 30 is connected to a conductor crimping portion 40 via a connecting portion 35.

The conductor crimping portion 40 is a portion of the exposed conductor core wire 11 of the electric wire 10 that is crimped at the predetermined location on the rear side of the terminal portion 11a. As shown in FIGS. 1, 2, and 4, the conductor crimping part 40 includes a base 41 (see FIGS. 2 and 4) and a pair of conductor crimping pieces 42. The base portion 41 has a substantially U-shaped cross section (perpendicular to the front-back direction) that opens upward, and extends in the front-back direction. The pair of conductor crimping pieces 42 have an arm-like shape extending upward from a pair of left and right end portions of the base 41 . Before being crimped onto the conductor core wire 11, the pair of conductor crimping pieces 42 extend upward while tilting outward in the left-right direction, as shown in FIGS. 1 and 2.

As shown in FIG. 1, the conductor clamping part 40 has a section extending along the inner surface from one end in the left-right direction to the other end (extending in the left-right direction when the conductor clamping part 40 is in the unfolded state). , a plurality (three in this example) of groove-shaped serrations 43 are formed so as to be lined up at intervals in the front-rear direction.

The sheathing crimping portion 60 is a portion that is crimped to the end portion of the insulation sheath 12 of the electric wire 10 . As shown in FIGS. 1, 2, and 4, the covering crimping portion 60 includes a base 61 (see FIG. 4) and a pair of covering crimping pieces 62. The base portion 61 has a substantially U-shaped cross section (perpendicular to the front-back direction) that is open upward, and extends in the front-back direction. The pair of cover crimping pieces 62 have an arm-like shape extending upward from a pair of left and right end portions of the base portion 61 . Before being crimped onto the insulating sheath 12, the pair of sheath crimping pieces 62 extend upward while tilting outward in the left-right direction, as shown in FIGS. 1 and 2.

The intermediate portion 50 is a portion that connects the base 41 of the conductor crimping portion 40 and the base 61 of the covering crimping portion 60 in the front-rear direction. Like the base portions 41 and 61, the intermediate portion 50 has a substantially U-shaped cross section (perpendicular to the front-back direction) that is open upward, and extends in the front-back direction. Each member constituting the terminal-equipped electric wire 1 has been described above.

Next, the crimping device 4 used for crimping the terminal fitting 20 to the electric wire 10 will be described. As shown in FIGS. 1 and 4, the crimping device 4 includes an anvil 2 and a crimper 3. The anvil 2 is a fixed mold and functions to support the terminal fitting 20. The crimper 3 is a movable mold located above the anvil 2 and is movable relative to the anvil 2 in the vertical direction.

As shown in FIGS. 1 and 4, the crimping device 4 includes, as the anvil 2, a front anvil 90 (not shown in FIG. 1), a conductor anvil 100, and a covering anvil 110. The front anvil 90, the conductor anvil 100, and the covering anvil 110 are arranged in a line in this order along the front-rear direction from the front side to the rear side. The front anvil 90 functions to support the terminal connecting portion 30 and the connecting portion 35 of the terminal fitting 20. The conductor anvil 100 functions to support the conductor clamping portion 40 of the terminal fitting 20. The covering anvil 110 functions to support the intermediate portion 50 and the covering crimping portion 60 of the terminal fitting 20.

The crimping device 4 includes a conductor crimper 70 and a covering crimper 80 as the crimpers 3. The conductor crimper 70 is arranged to face the conductor anvil 100 in the vertical direction, and crimps the pair of conductor crimping pieces 42 of the conductor crimping section 40 to crimp the conductor at the predetermined location of the conductor core wire 11. It functions to press the portion 40 together. The covering crimper 80 is arranged to face the covering anvil 110 in the vertical direction, and crimps the pair of covering crimping pieces 62 of the covering crimping part 60 to tighten the covering crimping part against the end portion of the insulation covering 12. It serves the function of crimping 60.

As shown in FIGS. 1 to 4, the conductor crimper 70 has a flat plate shape with a thickness equal to the distance between the front surface 71 and the rear surface 72, and has an upwardly recessed portion in the center of the lower surface in the left-right direction. A caulking surface 73 is formed. The crimping surface 73 is formed for crimping the pair of conductor crimping pieces 42 of the conductor crimping portion 40 of the terminal fitting 20 while guiding them. By employing the crimping surface 73 having the shape shown in FIG. They are crimped so that they are inserted into the upper part of the conductor core wire 11 while abutting each other (so that they have a so-called B crimp shape) (see FIGS. 4 and 8).

Specifically, as shown in FIG. 2, the crimping surface 73 is located at the center position of the conductor crimper 70 in the left-right direction with respect to the center plane H (see FIG. 2), which is a plane perpendicular to the left-right direction. It has a shape that is symmetrical in the direction, and extends in parallel to the front-rear direction over its entire area. The caulking surface 73 is composed of an introduction surface 74, a tapered surface 75, and an arcuate surface 76 on each side of the central plane H. The introduction surface 74, the tapered surface 75, and the arcuate surface 76 are arranged in this order from the bottom to the top and are smoothly continuous. In this way, the caulking surface 73 is composed of a pair of left and right introduction surfaces 74, a pair of left and right tapered surfaces 75, and a pair of left and right arcuate surfaces 76. Note that the central plane H can also be referred to as a plane above a point Pc in the figure (center position Pc to be described later) among the planes represented by the cross-sectional line CC.

The introduction surface 74 is constituted by a curved surface that moves inward in the left-right direction as it advances upward and projects downward. The tapered surface 75 is a flat surface that is inclined in a direction that moves inward in the left-right direction as it moves upward. The arcuate surface 76 is a curved surface that protrudes upward so as to have a substantially U-shape that opens downward when viewed from the front-rear direction. The inner ends of the pair of arcuate surfaces 76 in the left-right direction are connected to each other at a central position Pc on the central plane H. Note that the detailed shape of the arcuate surface 76 (see FIG. 3) will be described later.

As shown in FIG. 4, the covering crimper 80 has a flat plate shape with a thickness equal to the distance between the front surface 81 and the rear surface 82, and has an upwardly recessed crimper in the center of the lower surface in the left and right direction. A surface 83 is formed. The crimping surface 83 is formed to guide and crimp the pair of covering crimping pieces 62 of the covering crimping portion 60 of the terminal fitting 20 . In this example, the crimping surface 83 has the same shape as the crimping surface 73. For this reason, the pair of covering crimping pieces 62 are inserted into the upper part of the insulation covering 12 so as to surround the insulation covering 12 and with the pair of downwardly facing tips abutting each other (so-called B crimp). (see FIG. 4). The crimping device 4 has been described above.

Next, a procedure for crimping the terminal fitting 20 onto the electric wire 10 using the crimping device 4 will be described. The terminal fitting 20 is crimped to the electric wire 10 (specifically, the conductor crimping part 40 is crimped to the conductor core wire 11, and the covering crimping part 60 is crimped to the insulation coating 12) at once. . Specifically, as shown in FIG. 4, first, the terminal fitting 20 has the terminal connecting portion 30 and the connecting portion 35 supported on the upper surface 91 of the front anvil 90, and the conductor crimping portion 40 supported on the upper surface of the conductor anvil 100. 101 and placed on the anvil 2 so that the intermediate portion 50 and the covering crimping portion 60 are supported by the upper surface 111 of the covering anvil 110.

Next, in the electric wire 10, the exposed end portion 11a of the conductor core wire 11 is supported by the connecting portion 35, the predetermined portion of the exposed conductor core wire 11 is supported by the base portion 41 of the conductor crimping portion 40, and the insulation coating 12 is coated. It is placed on the terminal fitting 20 so as to be supported by the base 61 of the caulking portion 60 .

Next, as shown by the arrow shown in FIG. will be lowered to As a result, the conductor crimping portion 40 is sandwiched between the crimping surface 73 of the conductor crimper 70 and the upper surface 101 of the conductor anvil 100, and the crimping surface 83 of the covering crimper 80 and the covering anvil 110 are sandwiched. The crimping process progresses while the covering crimping part 60 is sandwiched between the upper surface 111 and the upper surface 111.

In the process of lowering the conductor crimper 70 and the covering crimper 80, the outer surfaces of the pair of conductor crimping pieces 42 of the conductor crimping part 40 come into contact with the crimping surface 73 of the conductor crimper 70 (the surface on the crimping surface 73 As a result, the pair of conductor crimping pieces 42 are deformed into a curved shape (being crimped) while being guided by the crimping surface 73. In this process, the outer surfaces of the pair of conductor crimping pieces 42 are rubbed on the surface of the crimping surface 73 of the conductor crimper 70 in the order of the pair of introduction surfaces 74, the pair of tapered surfaces 75, and the pair of arcuate surfaces 76. It moves.

Similarly, in the process of lowering the conductor crimper 70 and the covering crimper 80, the outer surfaces of the pair of covering crimping pieces 62 of the covering crimping part 60 come into contact with the crimping surface 83 of the covering crimper 80 (crimping By sliding on the surface 83), the pair of covering crimping pieces 62 are deformed into a curved shape (being crimped) while being guided by the crimping surface 83.

As shown in FIG. 4, when the conductor crimper 70 and the covering crimper 80 are lowered to the predetermined positions, the conductor crimping portion 40 is crimped to the conductor core wire 11 by the pair of conductor crimping pieces 42, and the pair of covering crimpers are crimped to the conductor core wire 11. When the crimping of the covering crimping portion 60 to the insulating coating 12 by the clamping piece 62 is completed, the crimping of the terminal fitting 20 to the electric wire 10 is completed. In the crimping completed state, as described above, the pair of conductor crimping pieces 42 are inserted into the upper part of the conductor core wire 11 so as to surround the conductor core wire 11 and with the pair of downwardly facing tip portions 42 a in contact with each other. The pair of covering crimping pieces 62 are crimped so as to be inserted into the insulation coating 12 (see FIG. 8), and the pair of covering crimping pieces 62 are crimped so as to surround the insulation coating 12, with the pair of tip portions facing downward being in contact with each other. It is crimped so as to be inserted into the upper part of the insulation coating 12.

By completing the crimping as described above, the terminal-equipped electric wire 1 shown in FIG. 4 is obtained. In the electric wire 1 with a terminal, the caulking piece 42 forms an arc-shaped portion extending from its distal end portion 42a toward its base end portion. As shown in FIG. 8, the outer surface of the arcuate portion (i.e., the crimping piece 42) has a distal end side curved surface (a curved surface corresponding to the rear curved surface 76b) adjacent to the distal end portion 42a, and a distal side curved surface and a proximal end portion. It has a proximal curved surface (a curved surface corresponding to the front curved surface 76a) located between the two. As a result, the degree of curvature of the distal side curved surface in a cross section perpendicular to the axis of the electric wire 1 with a terminal is smaller than the degree of curvature of the proximal side curved surface in that cross section.

Note that the terminal-equipped electric wire 1 shown in FIG. 4 is provided with a water-stopping material in the form of a resin paste so as to cover the crimped portion between the conductor crimping portion 40 and the conductor core wire 11 and the terminal portion 11a of the conductor core wire 11. Good too. The water stop material is provided so as to cover the end portion 11a of the conductor core wire 11 while flowing down from the pair of conductor crimping pieces 42 of the conductor crimping portion 40 toward the base 41.

Hereinafter, with reference to FIGS. 3 to 8, the detailed shape of the arcuate surface 76 on the crimping surface 73 of the conductor crimper 70 and the effect obtained by adopting this detailed shape will be described. As shown in FIG. 3, the arcuate surface 76 of the crimping surface 73 of the conductor crimper 70 has a front-stage curved surface 76a and a rear-stage curved surface 76a that have different degrees of curvature in a cross section perpendicular to the front-rear direction (extending direction of the electric wire 1 with a terminal). It is composed of a curved surface 76b. Specifically, the degree of curvature of the rear curved surface 76b is smaller than the degree of curvature of the front curved surface 76a.

The rear curved surfaces 76b of the pair of left and right arcuate surfaces 76 are arranged symmetrically in the left-right direction so as to be adjacent to each other in the left-right direction, and the inner ends in the left-right direction of the pair of left and right rear curved surfaces 76b are located at the center on the central plane H. They are connected to each other at position Pc. Of the arcuate surfaces 76, the front curved surface 76a is a portion that functions to guide the conductor crimping piece 42 toward the rear curved surface 76b, and the rear curved surface 76b guides the tip portion 42a of the conductor crimping piece 42 toward the conductor core wire 11. This is the part that functions to guide you to insert it into the top of the screen.

In the example shown in FIG. 3, the front curved surface 76a has a center Ca extending from the boundary position P1 between the tapered surface 75 and the arcuate surface 76 to the upper end position P2 of the arcuate surface 76 that projects upward in a cross section orthogonal to the front-rear direction. It has a shape corresponding to the arc of a perfect circle with radius Ra. The rear curved surface 76b has a shape corresponding to a perfect circular arc with a center Cb and a radius Rb, extending from the upper end position P2 to the center position Pc in a cross section perpendicular to the front-rear direction. Here, since the radius Rb is larger than the radius Ra, it is realized that the degree of curvature of the rear curved surface 76b is smaller than the degree of curvature of the front curved surface 76a.

When the above-mentioned crimping process is performed, the conductor crimping piece 42 of the terminal fitting 20 passes through the introduction surface 74 and the tapered surface 75 in this order, and then is guided toward the rear curved surface 76b via the front curved surface 76a, and is guided by the rear curved surface 76b. It is guided so as to be inserted into the upper part of the conductor core wire 11 (see FIGS. 5 to 8). According to the inventor's considerations, the degree of curvature of the rear curved surface 76b is smaller than the degree of curvature of the front curved surface 76a, so that the tip portion 42a of the conductor crimping piece 42 hits the outer peripheral surface of the conductor core wire 11 and is folded back. It has been shown that the problem of a closed state (see FIG. 9) can be suppressed. As this principle, for example, the following can be considered.

When the above-mentioned crimping process is performed, as shown in FIG. (i.e., curved). Thereafter, as shown in FIG. 6, when the tip 42a of the conductor crimping piece 42 passes through the front curved surface 76a and reaches the rear curved surface 76b, the degree of curvature of the rear curved surface 76b is smaller than the degree of curvature of the front curved surface 76a ( That is, since the rear curved surface 76b is closer to a flat surface, the tip portion 42a that has been deformed (curved) in advance by the front curved surface 76a is difficult to be pressed against (or slightly separated from) the surface of the rear curved surface 76b. Become. In the example shown in FIG. 6, the tip portion 42a is slightly away from the surface of the rear curved surface 76b. Thereafter, as shown in FIG. 7, the tip portion 42a of the conductor crimping piece 42 is guided to the rear curved surface 76b. At this stage, even if elastic recovery of the distal end portion 42a occurs due to so-called springback, the degree of curvature of the front curved surface 76a and the rear curved surface 76b may be the same, or the degree of curvature of the rear curved surface 76b may be lower than that of the front curved surface 76a. The external force exerted from the rear curved surface 76b to the tip portion 42a of the conductor crimping piece 42 (external force in a direction that increases the degree of deformation (curving) of the tip portion 42a) can be reduced compared to the case where the degree of deformation (curving) of the tip portion 42a increases. Due to the above principle, due to excessive deformation (curving) of the tip portion 42a of the conductor crimping piece 42, the tip portion 42a hits the outer peripheral surface of the conductor core wire 11 and is folded back (see FIG. 9). It is thought that this will be less likely to occur.

<Action/Effect>
As described above, according to the crimping device 4 according to the present embodiment, the conductor crimper 70 has the arcuate surface 76 that guides the conductor crimping piece 42 of the terminal fitting 20, and the conductor anvil 100 has the upper surface 101 facing the arcuate surface 76. A crimping process is performed using and so that the terminal fitting 20 is sandwiched between the arcuate surface 76 and the upper surface 101. The arcuate surface 76 of the conductor crimper 70 has a front curved surface 76a and a rear curved surface 76b having different degrees of curvature. Specifically, the degree of curvature of the rear curved surface 76b is smaller than the degree of curvature of the front curved surface 76a. When the crimping process is performed, the conductor crimping piece 42 of the terminal fitting 20 is guided toward the rear curved surface 76b via the front curved surface 76a, and is guided to be inserted into the conductor core wire 11 by the rear curved surface 76b. According to the inventor's considerations, as mentioned above, the degree of curvature of the rear curved surface 76b is smaller than the degree of curvature of the front curved surface 76a, so that the tip portion 42a of the conductor crimping piece 42 is aligned with the outer periphery of the conductor core wire 11. It has been shown that the problem of being folded back due to hitting a surface (see FIG. 9) can be suppressed.

<Other aspects>
Note that the present invention is not limited to the above embodiments, and various modifications can be adopted within the scope of the present invention. For example, the present invention is not limited to the embodiments described above, and can be modified, improved, etc. as appropriate. In addition, the material, shape, size, number, arrangement location, etc. of each component in the above-described embodiments are arbitrary as long as the present invention can be achieved, and are not limited.

For example, in the above embodiment, the front curved surface 76a has a shape corresponding to a perfect circular arc with a radius Ra in a cross section perpendicular to the front-back direction, and the rear curved surface 76b has a radius Ra in a cross section perpendicular to the front-back direction. It has a shape corresponding to an arc of a perfect circle with a radius Rb larger than the radius Rb. On the other hand, as long as the degree of curvature of the rear curved surface 76b in the cross section perpendicular to the front-back direction is smaller than the degree of curvature of the front curved surface 76a in the cross section, each of the front curved surface 76a and the rear curved surface 76b is perpendicular to the front-rear direction. The cross section may have a curved shape different from a perfect circle. In this case, the degree of curvature of the front curved surface 76a can be determined based on, for example, the average value of the curvatures at multiple points on the front curved surface 76a (that is, the reciprocal of the radius of curvature at each of the multiple points). . Specifically, it can be determined that the larger the average value, the greater the degree of curvature of the front curved surface 76a. The same applies to the rear curved surface 76b.

Here, the features of the crimping device 4, the method for manufacturing the electric wire 1 with a terminal, and the embodiment of the electric wire 1 with a terminal according to the present invention described above will be briefly summarized and listed below in [1] to [5].

[1]
A crimping device (4) for crimping a crimping piece (42) of a terminal fitting (20) to a conductor core wire (11) of an electric wire (10),
A first having an arcuate surface (76) for crimping the crimping piece (42) to the conductor core wire (11) while guiding the crimping piece (42) so as to cover the conductor core wire (11). A processing tool (70),
a second processing tool (100) having a facing surface (101) facing the arcuate surface (76);
configured to perform a crimping process by sandwiching the terminal fitting (20) between the arcuate surface (76) and the opposing surface (101) in a predetermined processing direction;
The arcuate surface (76) is
A rear curved surface (76b) that guides the tip end portion (42a) of the caulking piece (42) to be inserted into the conductor core wire (11), and a rear curved surface (76b) that guides the tip end (42a) of the caulking piece (42) to be inserted into the conductor core wire (11); (42), and a front curved surface (76a) that guides the
The degree of curvature of the rear curved surface (76b) in the cross section of the first processing tool (70) along the processing direction is smaller than the degree of curvature of the front curved surface (76a) in the cross section.
Crimping device (4).

According to the crimping device having the configuration [1] above, the first processing tool (for example, a crimper) has an arcuate surface that guides the crimping piece of the terminal fitting, and the second processing tool (for example, a crimper) has an opposing surface facing the arcuate surface. For example, the crimping process is performed using an anvil) so that the terminal fitting is sandwiched between the arcuate surface and the opposing surface. The arcuate surface of the first processing tool has a front curved surface and a rear curved surface having different degrees of curvature. Specifically, the degree of curvature of the rear curved surface is smaller than the degree of curvature of the front curved surface. When the crimping process is performed, the crimping piece of the terminal fitting is guided through the front curved surface toward the rear curved surface, and is guided by the rear curved surface so as to be inserted into the conductor core wire. According to the inventor's considerations, as mentioned above, because the degree of curvature of the rear curved surface is smaller than the degree of curvature of the front curved surface, the tip of the caulking piece hits the outer peripheral surface of the conductor core wire and is folded back. It has been shown that this reduces the number of problems that can occur. Therefore, the crimping device having this configuration can properly crimp the caulking piece of the terminal fitting to the conductor core wire of the electric wire.

[2]
In the crimping device (4) described in [1] above,
The front curved surface (76a) is
In the cross section, it has a shape corresponding to an arc of a perfect circle whose radius is a predetermined value (Ra),
The rear curved surface (76b) is
In the cross section, it has a shape corresponding to an arc of a perfect circle whose radius is a value (Rb) larger than the predetermined value (Ra).
Crimping device (4).

According to the crimping device having the configuration [2] above, in the cross section, the front curved surface has a shape corresponding to an arc of a perfect circle whose radius is a predetermined value, and the rear curved surface has a radius smaller than the predetermined value. It has a shape corresponding to the arc of a perfect circle, which is a large value. Thereby, it is possible to realize the above-described relationship in the degree of curvature between the front-stage curved surface and the rear-stage curved surface.

[3]
In the crimping device (4) described in [1] or [2] above,
The first processing tool (70) has the pair of arcuate surfaces (76),
The pair of arcuate surfaces (76) are
In the width direction, the rear curved surface (76b) of one of the arcuate surfaces (76) and the rear curved surface (76b) of the other arcuate surface (76) are adjacent to each other in the width direction intersecting the processing direction. arranged symmetrically in
Crimping device (4).

According to the crimping device having the configuration [3] above, the first processing tool has a pair of arcuate surfaces arranged symmetrically in the width direction. As a result, the conductor core wire of the electric wire is covered with a pair of crimping pieces, and the wire is crimped so that the tip of the pair of crimping pieces bites into the conductor core wire (a so-called B crimp-like crimping shape). Can crimp terminal fittings.

[4]
A method for manufacturing an electric wire with a terminal, the method for manufacturing an electric wire with a terminal (1) in which a crimping piece (42) of a terminal fitting (20) is crimped onto a conductor core wire (11) of the electric wire (10), ,
The conductor core wire (11) and the caulking piece (42) are provided between the arcuate surface (76) of the first processing tool (70) and the opposing surface (101) of the second processing tool (100). an arrangement step of arranging the
The conductor core wire (11) and the caulking piece (42) are sandwiched between the arcuate surface (76) and the opposing surface (101) in a predetermined processing direction, and the conductor core wire (11) is covered. a crimping step of crimping the clamping piece (42) to the conductor core wire (11),
In the crimping process, the arcuate surface (76) of the first processing tool (70)
a rear curved surface (76b) that guides the tip end (42a) of the caulking piece (42) to be inserted into the conductor core wire (11); a front curved surface (76a) that guides the
The degree of curvature of the rear curved surface (76b) in the cross section of the first processing tool (70) along the processing direction is smaller than the degree of curvature of the front curved surface (76a) in the cross section.
A method for manufacturing electric wires with terminals.

According to the method for manufacturing an electric wire with a terminal having the configuration of [4] above, a first processing tool (for example, a crimper) having an arcuate surface that guides the caulking piece of the terminal fitting, and a first processing tool having an opposing surface facing the arcuate surface. A crimping process is performed using two processing tools (for example, an anvil) so that the terminal fitting is sandwiched between the arcuate surface and the opposing surface. The arcuate surface of the first processing tool has a front curved surface and a rear curved surface having different degrees of curvature. Specifically, the degree of curvature of the rear curved surface is smaller than the degree of curvature of the front curved surface. When the crimping process is performed, the crimping piece of the terminal fitting is guided through the front curved surface toward the rear curved surface, and is guided by the rear curved surface so as to be inserted into the conductor core wire. According to the inventor's considerations, the degree of curvature of the rear curved surface is smaller than the degree of curvature of the front curved surface, resulting in a problem in which the tip of the caulking piece hits the outer peripheral surface of the conductor core wire and is folded back. has been shown to be suppressed. An example of this principle is as described above. Therefore, according to the manufacturing method of this configuration, it is possible to manufacture an electric wire with a terminal in which the caulking piece of the terminal fitting is appropriately crimped to the conductor core wire of the electric wire.

[5]
An electric wire (1) with a terminal, comprising an electric wire (10) and a terminal fitting (20) having a caulking piece (42) crimped to a conductor core wire (11) of the electric wire (10),
The caulking piece (42) of the terminal fitting (20) is
The tip portion (42a) of the caulking piece (42) is crimped to the conductor core wire (11) so as to cover the conductor core wire (11) while being inserted into the conductor core wire (11). It has an arcuate portion extending from the location (42a) toward the base end location of the caulking piece (42),
The outer surface of the arcuate portion is
a distal end side curved surface adjacent to the distal end portion (42a), and a proximal side curved surface located between the distal side curved surface and the proximal end portion,
The degree of curvature of the distal side curved surface in a cross section perpendicular to the axis of the electric wire is smaller than the degree of curvature of the proximal side curved surface in the cross section,
Electric wire with terminal (1).

According to the electric wire with a terminal configured as described in [5] above, the tip of the crimping piece of the terminal fitting is crimped to the conductor core wire so as to cover the conductor core wire when it is inserted into the conductor core wire of the wire. . Therefore, compared to the case where the tip of the crimping piece is not inserted into the conductor core wire, the contact area between the conductor core wire and the crimping piece is expanded, and the crimping piece may unintentionally separate from the conductor core wire after crimping. things are suppressed. Therefore, the electric wire with a terminal of this configuration can improve the reliability of the electrical connection between the conductor core wire and the terminal fitting.

1 Electric wire with terminal 4 Crimping device 10 Electric wire 11 Conductor core wire 20 Terminal fitting 42 Conductor crimping piece (crimping piece)
42a Tip location 70 Crimper for conductor (first processing tool)
76 Arc-shaped surface 76a Front curved surface 76b Back curved surface 100 Anvil for conductor (second processing tool)
101 Top surface (opposite surface)

Claims (5)

A crimping device for crimping a caulking piece of a terminal fitting to a conductor core wire of an electric wire, the crimping device comprising:
a first processing tool having an arcuate surface for crimping the crimping piece to the conductor core wire while guiding the crimping piece so as to cover the conductor core wire;
a second processing tool having an opposing surface facing the arcuate surface,
configured to perform a crimping process by sandwiching the terminal fitting between the arcuate surface and the opposing surface in a predetermined processing direction,
The arcuate surface is
It has a rear curved surface that guides the tip of the caulking piece to be inserted into the conductor core wire, and a front curved surface that guides the caulking piece toward the rear curved surface,
The degree of curvature of the rear curved surface in the cross section of the first processing tool along the processing direction is smaller than the degree of curvature of the front curved surface in the cross section.
Crimping device. The crimping device according to claim 1,
The front curved surface is
In the cross section, it has a shape corresponding to an arc of a perfect circle with a radius of a predetermined value,
The latter curved surface is
In the cross section, it has a shape corresponding to an arc of a perfect circle whose radius is larger than the predetermined value;
Crimping device. The crimping device according to claim 1 or 2,
The first processing tool has a pair of the arcuate surfaces,
The pair of arcuate surfaces are
arranged symmetrically in the width direction so that the rear curved surface of one of the arcuate surfaces and the rear curved surface of the other arcuate surface are adjacent to each other in the width direction that intersects the processing direction;
Crimping device. A method for manufacturing an electric wire with a terminal for manufacturing an electric wire with a terminal in which a caulking piece of a terminal fitting is crimped onto a conductor core wire of the electric wire, the method comprising:
an arrangement step of arranging the conductor core wire and the caulking piece between an arcuate surface of a first processing tool and an opposing surface of a second processing tool;
a crimping step of sandwiching the conductor core wire and the crimping piece between the arcuate surface and the opposing surface in a predetermined processing direction, and crimping the crimping piece to the conductor core wire so as to cover the conductor core wire. ,
The arcuate surface of the first processing tool is
a rear curved surface that guides the tip of the crimping piece to be inserted into the conductor core wire in the crimping step, and a front curved surface that guides the crimping piece toward the rear curved surface,
The degree of curvature of the rear curved surface in the cross section of the first processing tool along the processing direction is smaller than the degree of curvature of the front curved surface in the cross section.
A method for manufacturing electric wires with terminals. An electric wire with a terminal, comprising an electric wire and a terminal fitting having a caulking piece that is crimped to a conductor core wire of the electric wire,
The caulking piece of the terminal fitting is
With the tip of the crimping piece inserted into the conductor core wire, the crimping piece is crimped to the conductor core so as to cover the conductor core, and from the tip to the base end of the crimping piece. has an arcuate portion extending toward
The outer surface of the arcuate portion is
a distal end side curved surface adjacent to the distal end portion, and a proximal side curved surface located between the distal side curved surface and the proximal end portion,
The degree of curvature of the distal side curved surface in a cross section perpendicular to the axis of the electric wire is smaller than the degree of curvature of the proximal side curved surface in the cross section,
Electric wire with terminal.

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