Crimping tool, method for producing an electrical wire attached to a terminal, and electrical wire attached to a terminal

Abstract

In a crimping tool 10 having a lower die 14 and an upper die 16 for crimping a crimp forming part 112 of a crimp terminal 110 to an electric wire 101, for example, a lower die central convex portion 22a of a lower die recessed portion 22 provided in the lower die 14 has an upper end surface 22c and a front wall surface 22d and a rear wall surface 22e arranged opposite to each other in the longitudinal direction. For example, if the edge where the front wall surface 22d meets the upper end surface 22c is defined as the first edge 22f, and the inclination angle of the front wall surface 22d with respect to a vertical axis AX from the first edge 22f is defined as the notch angle θ1, the notch angle θ1 is in a range of 20° or more and 30° or less.

Description

field of technology

[0001] The present invention relates to a crimping tool, a method for manufacturing an electric wire attached to a terminal, and an electric wire attached to a terminal. background

[0002] Typically, a terminal crimping machine is designed to produce an electrical wire attached to a terminal by crimping a crimp forming part onto an end portion of an electrical wire. Generally, a terminal crimping machine uses a crimping tool comprising a lower die and an upper die. The lower die and the upper die are held close to each other and free from each other in a vertical direction, and when brought close to each other, they form a crimped part through plastic deformation of the crimp forming part.

[0003] JP 2022-42683 A discloses a technology related to a crimping tool comprising a lower die and an upper die, each having a recessed portion with a protrusion in contact with a crimp forming part, a concave portion near one side in a width direction of the recessed portion, and a convex portion near the other side in the width direction of the recessed portion. Here, the width direction is a direction perpendicular to a longitudinal direction aligned with the axial direction of the crimp forming part. When the lower die and the upper die of the crimping tool are brought close to each other while the crimp forming part is placed on the recessed portion of the lower die, the convex portion of the lower die engages with the concave portion of the upper die, and the convex portion of the upper die engages with the concave portion of the lower die.The recessed portion of the lower die and the recessed portion of the upper die then form a crimping part by compressing the crimping part while holding it between the convex portions located at both ends in the width direction. The convex portions thereby restrict the plastic deformation of the crimping part due to expansion in the width direction, preventing the crimp terminal from being fitted into the crimping tool and preventing the occurrence of burrs in the crimping part. Summary of the invention

[0004] Since conditions regarding the shape of a crimping die in the crimping die disclosed in JP 2022-42683 A are practically unknown, in order to improve the electrical performance of a terminal-attached electric wire manufactured using the crimping die, it is desirable to make a specific proposal.

[0005] The object of the present invention is to provide a crimping tool that improves the electrical performance of an electrical wire attached to a terminal, a method for manufacturing an electrical wire attached to a terminal having the improved electrical performance, or an electrical wire attached to a terminal.

[0006] One embodiment of the present invention is a crimping tool having a lower die and an upper die for crimping a crimp forming part of a crimp terminal to an electrical wire when the lower die and the upper die are brought close to each other in a vertical direction; wherein the lower die and the upper die each have a rectangular parallelepiped shape with a cross section on a horizontal plane defined in a longitudinal direction aligned with an axial direction of the crimp forming part and in a width direction perpendicular to the longitudinal direction;and wherein the lower die and the upper die each comprise: a depressed portion provided in a concave portion and having a central convex portion protruding in the crimping direction, the concave portion being formed on a die surface aligned in a crimping direction and contacting the crimp forming part along the longitudinal direction; a concave portion adjacent to one end of the depressed portion in the width direction and extending from the die surface in a direction opposite to the crimping direction; a convex portion adjacent to the other end of the depressed portion in the width direction and protruding from the die surface in the crimping direction; the central convex portion of the depressed portion including an upper end surface and a front wall surface and a rear wall surface opposite to each other in the longitudinal direction;wherein, when an end edge where the front wall surface meets the upper end surface is defined as a first end edge, and an end edge where the rear wall surface meets the upper end surface is defined as a second end edge; and when an inclination angle of the front wall surface with respect to a vertical axis from the first end edge and an inclination angle of the rear wall surface with respect to a vertical axis from the second end edge are each defined as a notch angle, the notch angle is in a range of 20° or more and 30° or less.;

[0007] Furthermore, according to one aspect of the present invention, a method for manufacturing a terminal-attached electric wire in which a crimp forming part of a crimp terminal is crimped to the electric wire comprises a step of inserting a part of the electric wire into the crimp forming part; and a step of holding the crimp forming part, into which a part of the electric wire is inserted, with a crimping die including a lower die and an upper die. The crimping die is the crimping die according to the above-mentioned aspect.

[0008] Furthermore, the terminal-attached electric wire according to one embodiment of the present invention comprises a crimping part formed by holding a crimping forming part, into which a part of an electric wire is inserted, with a crimping tool including a lower die and an upper die; wherein the crimping part has a concave lower crimping portion into which a convex shape of a part of the lower die is transferred, and a concave upper crimping portion into which a convex shape of a part of the upper die is transferred; wherein the concave lower crimping portion and the concave upper crimping portion each have a bottom surface and a front inner wall surface and a rear inner wall surface that are opposite to each other in a longitudinal direction aligned with the axial direction of the crimping forming part;wherein, when a corner where the front inner wall surface meets the bottom surface is set as a first corner, and a corner where the rear inner wall surface meets the bottom surface is set as a second corner, and when an inclination angle of the front inner wall surface with respect to a vertical axis from the first corner and an inclination angle of the rear inner wall surface with respect to a vertical axis from the second corner are defined as an angle of a concave portion, the angle of the concave portion is in the range of 20° or more and 30° or less;

[0009] According to the present invention, it is possible to provide a crimping tool that improves the electrical performance of an electrical wire attached to a terminal, a method for manufacturing an electrical wire attached to a terminal having the improved electrical performance, or an electrical wire attached to a terminal. Short description of the drawings Fig. 1 is a perspective view of a terminal crimping apparatus that may utilize a crimping tool according to one embodiment. Fig. 2 is a perspective view of an electrical wire attached to a terminal, manufactured using a crimping tool according to an embodiment. Fig. 3 is a perspective view illustrating an electrical wire and a crimp terminal before they are mounted on the terminal crimping device. Fig. 4 is a perspective view of a crimping tool according to one embodiment. Fig. 5 is a perspective view of a lower die embodying a swaging tool according to one embodiment. Fig. 6 is a partial cross-sectional view showing states of the lower die and the upper die before they are brought close to each other. Fig. 7 is a partial cross-sectional view showing states of the lower die and the upper die during the crimping process. Fig. 8 is a partial cross-sectional view showing states of the lower die and the upper die after they have been separated. Fig. Figure 9 is a partial cross-sectional view of the lower die, corresponding to a section IX-IX in Fig. 5 corresponds. Fig. Figure 10 is a partial cross-sectional view of an electrical wire attached to a terminal, corresponding to a section XX in Fig. 2 corresponds. Fig. 11 is a diagram illustrating an electric performance of an electric wire attached to a terminal in Example 1. Fig. 12 is a diagram illustrating an electric performance of an electric wire attached to a terminal in a second example. Fig. 13 is a diagram illustrating an electric performance of an electric wire attached to a terminal in a third example. Detailed description of the invention

[0010] Hereinafter, a crimping tool, a method for manufacturing a terminal-attached electric wire, and a terminal-attached electric wire according to an embodiment will be described in detail with reference to the drawings. The dimensional relationships in the drawings are exaggerated for illustrative purposes and may differ from the actual relationships.

[0011] Fig. 1 is a perspective view of a terminal crimping device 1 that can use a crimping tool 10 according to an embodiment. Hereinafter, directions of the terminal crimping device 1 and the crimping tool 10 are defined as follows, for example: an X direction indicates a longitudinal direction aligned with an axial direction of a crimp terminal 110 mounted on the crimping tool 10, from a rear side to a front side of the crimp terminal 110; a Y direction indicates a width direction perpendicular to the X direction on a horizontal plane; and a Z direction indicates a vertical direction from a lower side to an upper side. The terms "front" and "rear" may be used for the X direction. In addition, the terms "top" and "bottom" may be used for the Z direction.

[0012] Fig. 2 is a perspective view of an electrical wire 100 attached to a terminal according to an embodiment, manufactured using the crimping tool 10. Fig. 3 is a perspective view illustrating an electric wire 101 and the crimp terminal 110 before they are mounted on the terminal crimping device 1.

[0013] The terminal crimping device 1 manufactures the terminal-attached electric wire 100 by crimping a crimp forming part 112 of the crimp terminal 110 to an end portion of the electric wire 101 to form a crimp part 114.

[0014] The electric wire 101 may be a high-voltage wire used in a high-voltage circuit of an electric vehicle or the like. The electric wire 101 includes a core wire 102 and a cover member 103 covering the core wire 102. The core wire 102 is, for example, a twisted wire comprising a plurality of wires made of soft copper. In the corresponding drawings below, the core wire 102 is shown in the cross section of a single conductor for the sake of simplicity. The cover member 103 is an insulating member containing a synthetic resin, such as polyethylene. As shown in Fig. 3, before the electric wire 101 is mounted on the terminal crimping device 1, the cover member 103 is removed at an end portion of the electric wire 101, and a part of the core wire 102 is exposed to the outside.

[0015] As described above, the crimp terminal 110 is a terminal made of metal and crimped to an end portion of the electric wire 101, specifically, the core wire 102 exposed to the outside with the cover member 103 peeled off. The crimp terminal 110 may be made of, for example, pure copper with a copper content of 99.90% or more, and may be further silver-plated. Here, the pure copper may be oxygen-free copper, tough pitch copper, phosphorus-deoxidized copper, or the like. The crimp terminal 110 is rod-shaped overall and includes a connecting portion 111, a crimp forming portion 112, and a flange 113.

[0016] The connecting portion 111 is, for example, a cylindrical portion located on a front side of the crimp terminal 110 in the X direction along the axial direction of the crimp terminal 110. The connecting portion 111 is connected to an opposite connecting portion of an opposite terminal, so that the crimp terminal 110 and the opposite terminal are electrically connected.

[0017] The crimping forming part 112 is a cylindrical portion located on the crimping terminal 110 on a rear side of the flange 113 in the X direction. The crimping forming part 112 has an insertion hole 112a extending in the axial direction of the crimping forming part 112, and a tip of the core wire 102 is inserted into the insertion hole 112a. In other words, the present embodiment uses a closed-cylinder type crimping terminal 110.

[0018] The flange 113 is a cylindrical portion disposed between the connecting portion 111 and the crimping forming part 112, and protrudes radially outward from an outer periphery of the crimping forming part 112. An annular groove 113a, to which a sealing member can be freely attached, may be formed on an outer periphery of the flange 113.

[0019] The terminal crimping device 1 includes a base 11, an electric wire holder 12, a frame 13, a lower die 14, a motion controller 15, an upper die 16, and a drive device (not shown). The lower die 14 and the upper die 16 constitute the crimping tool 10 according to this embodiment.

[0020] The base 11 is, for example, a block-like structure of a rectangular parallelepiped or the like, which is fixed on a work table on which the terminal crimping device 1 is placed.

[0021] The electric wire holder 12 includes a first holder 12a fixed to the base 11 and on which the electric wire 101 is placed; and a second holder 12b configured to be brought close to and separated from the first holder 12a in the Z direction and to hold the electric wire 101 placed on the first holder 12a. The first holder 12a has a groove 12c located at a central portion in the Y direction and extending in the X direction. The electric wire 101 is disposed in the groove 12c, so that the first holder 12a restricts the movement of the electric wire 101 in the Y direction. The electric wire holder 12 first places the electric wire 101 on the first holder 12a, with the second holder 12b separated from the first holder 12a in the Z direction.Thereafter, the electric wire holder 12 brings the second holder 12b close to the first holder 12a in the Z direction and finally holds the electric wire 101 between the first holder 12a and the second holder 12b. When the electric wire 101 is held between the first holder 12a and the second holder 12b, the movement of the electric wire 101 in the X, Y, or Z direction is restricted.

[0022] The frame 13 is fixed to the base 11 and comprises a frame body 13a and a frame support 13b which supports the upper die 16 so as to be movable in the Z direction with respect to the frame body 13a.

[0023] Fig. 4 is a perspective view of the crimping tool 10 at an illustrated angle in which a front side of the crimping tool 10 in the X direction can be visually recognized. Fig. 4 illustrates the crimping tool 10 in a state in which the crimp forming part 112 of the crimp terminal 110 is placed on the lower die 14 and the crimp forming part 112 is not yet held between the lower die 14 and the upper die 16. Fig. 5 is a perspective view of the lower die 14 at an angle shown in which a front side of the lower die 14 in the X direction is visually recognizable.

[0024] The lower die 14 of the crimping tool 10 is supported by the base 11 and, together with the upper die 16, forms a pair of dies for holding and compressing the crimp forming part 112. The lower die 14 may be referred to as an "anvil." The lower die 14 has a lower die body 20 and a lower die concave portion 21.

[0025] The lower die body 20 is a rectangular parallelepiped block with a cross-section on a horizontal plane defined in the X and Y directions. The lower die body 20 has a lower die surface 20a. The lower die surface 20a is a die surface of the lower die 14, which faces the upper die 16 and is brought close to the upper die surface 30a (see Fig. 6) when the lower die 14 and the upper die 16 are brought together.

[0026] The lower die concave portion 21 is located at a central part of the lower die surface 20a of the lower die body 20 in the Y direction and is shaped to have a recess in the X direction. The lower die concave portion 21 has a lower die bottom surface 21a whose width in the Y direction is set to be smaller than an opening width in the Y direction in an opening area opened on the lower die surface 20a. Further, the lower die concave portion 21 has a first inclined side surface 21b and a second inclined side surface 21c, which extend from the lower die bottom surface 21a and are formed symmetrically in the Y direction.One end of the first inclined side surface 21b extends continuously with one end of the lower die bottom surface 21a extending in the X direction, and the other end of the first inclined side surface 21b extends continuously with the lower die surface 20a. Similarly, one end of the second inclined side surface 21c extends continuously with the other end of the lower die bottom surface 21a extending in the X direction, and the other end of the second inclined side surface 21c extends continuously with the lower die surface 20a. The first inclined side surface 21b and the second inclined side surface 21c are inclined so that they extend away from each other in the Y direction as they extend from the lower die bottom surface 21a toward the lower die surface 20a. The lower die concave portion 21 has a lower die recessed portion 22, which is a recessed portion 22 provided on the lower die 14.

[0027] The crimp forming part 112 is placed on the recessed portion 22 of the lower die located on the lower die bottom surface 21a. The recessed portion 22 of the lower die crimps the crimp forming part 112 located at a tip of the electric wire 101, thereby transferring the shape of the recessed portion 22 of the lower die to the crimping part 114 to form a lower crimping part 114a of the crimping part 114 (see Fig. 7 and Fig. 8). The lower die recessed portion 22 includes a lower die central convex portion 22a and a pair of lower die recessed portion bottom surfaces 22b. The lower die central convex portion 22a, which protrudes in a crimping direction, is lower than the lower die surface 20a in the Z direction and is located in a central part of the lower die body 20 in the Y direction. Here, the crimping direction with respect to the lower die 14 is a direction from a lower side to an upper side in the Z direction. The lower die recessed portion bottom surfaces 22b are located on both sides of the lower die central convex portion 22a in the Y direction and are formed below the lower die central convex portion 22a in the Z direction. A bottom surface 22b of the recessed portion of the lower die extends continuously with the first inclined side surface 21b.The other bottom surface 22b of the recessed portion of the lower die extends continuously with the second inclined side surface 21c.

[0028] Subsequently, a width of the central convex portion 22a of the lower die in the Y direction is defined as a recess width W. A height in the Z direction from the bottom surfaces 22b of the recessed portion of the lower die to an upper end surface 22c of the central convex portion 22a of the lower die is defined as a recess height H.

[0029] The lower die 14 has a concave portion 23 of the lower die and a convex portion 24 of the lower die. The concave portion 23 of the lower die and the convex portion 24 of the lower die are adjacent to each other in the Y direction above the concave portion 21 of the lower die, which includes the recessed portion 22 of the lower die.

[0030] The concave portion 23 of the lower die is formed via the first inclined side surface 21b in the Y direction adjacent to one end of the recessed portion 22 of the lower die and downward in the Z direction from the lower die surface 20a. The concave portion 23 of the lower die has a bottom surface 23a (see Fig. 6) and a first inner surface 23b and a second inner surface 23c (see Fig. 6) facing each other in the Y-direction, and a third inner surface 23d (see Fig. 6) and a fourth inner surface 23e, which face each other in the X direction. The first inner surface 23b is closest to the recessed portion 22 of the lower die among a plurality of inner surfaces forming the concave portion 23 of the lower die.

[0031] The convex portion 24 of the lower die is adjacent to the other end of the recessed portion 22 of the lower die in the Y direction via the second inclined side surface 21c and projects upwards from the surface 20a of the lower die in the Z direction. Note that the convex portion 24 of the lower die can be considered a wall erected directly adjacent to the recessed portion 22 of the lower die and can therefore be referred to as a "horizontal wall" or a "support." The convex portion 24 of the lower die has an end surface 24a as well as a first outer surface 24b and a second outer surface 24c (see Fig. 6), which face each other in the Y direction, and a third outer surface 24d and a fourth outer surface 24e, which face each other in the X direction. The first outer surface 24b is closest to the recessed region 22 of the lower die among a plurality of outer surfaces forming the convex region 24 of the lower die.

[0032] As in Fig. As shown in Figure 1, the motion regulator 15 is provided on the front side of the lower die 14 in the X direction. The motion regulator 15 includes the regulator body 15a and the pair of flange receiving portions 15b.

[0033] The regulator body 15a is, for example, a rectangular parallelepiped block body. The two flange receiving portions 15b protrude upward from an upper surface of the regulator body 15a and are spaced apart from each other in the Y direction. When the connecting portion 111 of the crimp terminal 110 is inserted between one flange receiving portion 15b and the other flange receiving portion 15b, the movement of the crimp terminal 110 in the Y direction is restricted. When the crimp forming part 112 is arranged on the recessed area 22 of the lower die, the movement of the crimp terminal 110 toward the front side in the X direction is restricted by the flange 113 of the crimp forming part 112, which contacts the two flange receiving portions 15b in the X direction.

[0034] The upper die 16 of the crimping tool 10 is held by the frame 13. The upper die 16 may be referred to as a "crimper." The upper die 16 is held by the frame support 13b and faces the lower die 14 in the Z direction. Furthermore, by moving the frame support 13b in the Z direction with respect to the frame body 13a, the upper die 16 is brought close to and separated from the lower die 14. Here, a crimping direction with respect to the upper die 16 is the direction from an upper side to a lower side in the Z direction. The upper die 16 has a shape such that it is obtained by rotating the lower die 14 by 180° while maintaining parallel orientation to a YZ plane. In other words, the shape of the upper die 16 is essentially the same as that of the lower die 14. However, there may be differences between the lower die 14 and the upper die 16, such as a length in the Z direction.

[0035] The upper die 16 has an upper die body 30 and an upper die concave portion 31. An upper end of the upper die body 30 has the same shape as that of the lower die body 20, and the length of the upper die body 30 in the Z direction is greater than that of the lower die body 20. A die surface of the upper die body 30 is an upper die surface 30a. The upper die concave portion 31, which has the same shape as the lower die concave portion 21, has an upper die bottom surface and faces the lower die concave portion 21 in the Z direction. A recessed portion 32 of the upper die (see Fig. 6) has the same shape as the recessed portion 22 of the lower die and faces the recessed portion 22 of the lower die in the Z direction. The recessed portion 32 of the upper die crimps the crimp forming part 112 located at a tip of the electric wire 101, thereby transferring the shape of the recessed portion 32 of the upper die to the crimping part 114 to form the upper crimping part 114b of the crimping part 114 (see Fig. 7 and Fig. 8). The upper die recessed portion 32 has an upper central convex portion 32a and a pair of upper recessed portion bottom surfaces 32b. One upper recessed portion bottom surface 32b extends continuously with a first inclined side surface 31b. The other upper recessed portion bottom surface 32b extends continuously with a second inclined side surface 31c.

[0036] In addition, the upper die 16 has a convex area 33 of the upper die (see Fig. 6) and a convex portion 34 of the upper die. The convex portion 33 of the upper die has the same shape as the concave portion 23 of the lower die and engages with the lower convex portion 24 when brought close to the lower die 14. The convex portion 34 of the upper die has the same shape as the lower convex portion 24 and engages with the concave portion 23 of the lower die when brought close to the lower die 14. Note that the convex portion 34 of the upper die, like the lower convex portion 24, is considered a wall erected directly adjacent to the depressed portion 32 of the upper die and can therefore be referred to as a "horizontal wall" or a "support bar."

[0037] Furthermore, the drive device moves the frame carrier 13b in the Z direction with respect to the frame body 13a, whereby the upper die 16 is brought close to and away from the lower die 14 in the Z direction.

[0038] Next, manufacturing steps of the terminal-attached electric wire 100 by the terminal crimping apparatus 1 including the crimping tool 10 will be described.

[0039] Fig. Figure 6 is a cross-sectional view of the crimping tool 10, corresponding to a section VI-VI in Fig. 1. In particular, the Fig. 6 is a partial cross-sectional view illustrating states of the lower die 14 and the upper die 16 before the crimp forming part 112 of the crimp terminal 110 is placed on the lower die recessed portion 22 of the lower die 14 and the crimp forming part 112 is crimped to the electric wire 101, that is, before the lower die 14 and the upper die 16 are brought close to each other.

[0040] Fig. Fig. 7 is a partial cross-sectional view showing states of the lower die 14 and the upper die 16 in which, starting from the positions shown in Fig. 6, the upper die 16 is brought close to the lower die 14, and then the crimp forming part 112 is pressed to form the crimp part 114.

[0041] Fig. Fig. 8 is a partial cross-sectional view showing a state in which the finally formed crimping part 114 is located on the lower die recessed portion 22 of the lower die 14 after, starting from the position shown in Fig. 7, the upper die 16 was separated from the lower die 14.

[0042] First, in the terminal crimping apparatus 1, a step is performed in which a part of the electric wire 101 is inserted into the crimping forming part 112. Specifically, the crimping terminal 110 is mounted at a predetermined position of the terminal crimping apparatus 1 so that the crimping forming part 112 is placed on the recessed portion 22 of the lower die. Next, the electric wire 101 is placed on the first holder 12a of the electric wire holder 12, and the core wire 102 of the electric wire 101 is then inserted into the insertion opening 112a of the crimping forming part 112. Then, the electric wire 101 is held between the first holder 12a and the second holder 12b by bringing the second holder 12b close to the first holder 12a. The state of the crimping forming part 112 at this stage is shown in the Fig. 6 shown.

[0043] Next, in the terminal crimping device 1, a step is performed in which the crimp forming part 112 is crimped to the electric wire 101. Specifically, the terminal crimping device 1 moves the upper die 16 toward the lower die 14 by driving the drive device. Through this operation, as shown in Fig. 7, the upper die 16 is brought close to the lower die 14, and the crimp forming part 112 is crimped (compressed) by holding it between the recessed portion 22 of the lower die and the recessed portion 32 of the upper die. At this point, the crimp forming part 112 extends in the Y direction while being compressed in the Z direction, and finally, the shapes of the recessed portion 22 of the lower die and the recessed portion 32 of the upper die are transferred to the crimp terminal 110 to form the crimp part 114. In this way, the terminal crimping device 1 crimps the core wire 102 inserted into the insertion hole 112a of the crimp terminal 110 and the crimp forming part 112, thereby manufacturing the terminal-attached electric wire 100 in which the crimp terminal 110 and the electric wire 101 are integrated, as shown in FIG. Fig. 2 shown.

[0044] Thereafter, the terminal crimping device 1 drives the drive device again to move the upper die 16 away from the lower die 14. This process separates the upper die 16 and the lower die 14 from each other, as shown in Fig. 8, and the electrical wire 100 attached to a terminal can be removed from the lower die 14.

[0045] Next, the setting of a notch angle will be described, which is one of the factors that define the shapes of the recessed portion 22 of the lower die and the recessed portion 32 of the upper die. Since the shape of the recessed portion 22 of the lower die and the shape of the recessed portion 32 of the upper die are the same, the setting will be described below with emphasis on the recessed portion 22 of the lower die.

[0046] Fig. Figure 9 is a partial cross-sectional view of the lower die 14, corresponding to a section IX-IX in Fig. 5. The cross section in Fig. 9 is a virtual XZ plane passing through an intermediate position of the recessed portion 22 of the lower die in a width direction corresponding to the Y direction of the lower die 14.

[0047] First, in the longitudinal direction corresponding to the X direction of the lower die 14, a width of the body portion 20 of the lower die is defined as a first width W1, and a width of the convex portion 24 of the lower die is defined as a second width W2. The second width W2 is shorter than the first width W1. Similarly, in the longitudinal direction, a length of the upper end surface 22c of the central convex portion 22a of the lower die of the recessed portion 22 of the lower die is defined as a recess length L. The recessed portion 22 of the lower die is located within a range defined by the second width W2 in the longitudinal direction. In other words, the recess length L is shorter than the second width W2.

[0048] The lower die recessed portion 22 includes a front wall surface 22d and a rear wall surface 22e as wall portions opposite each other in the longitudinal direction. The front wall surface 22d and the rear wall surface 22e are inclined so that their distance from each other gradually increases in the longitudinal direction from the upper end surface 22c of the lower die central convex portion 22a to the lower die bottom surface 21a. An edge where the front wall surface 22d meets the upper end surface 22c is defined here as a first edge 22f, and an edge where the rear wall surface 22e meets the upper end surface 22c is defined as a second edge 22g. An inclination angle of the front wall surface 22d with respect to a vertical axis AX from the first edge 22f and an inclination angle of the rear wall surface 22e with respect to the vertical axis AX from the second edge 22g are each defined as a notch angle θ1.

[0049] Fig. Fig. 10 is a partial cross-sectional view of the electrical wire 100 attached to a terminal, corresponding to a section XX in Fig. 2. In particular, the Fig. 10 is a cross-sectional view of the crimping part 114 and its periphery in the electrical wire 100 attached to a terminal. The cross section in Fig. 10 is an imaginary XZ plane passing through the center axis of the crimp terminal 110.

[0050] In the crimping part 114, the shape of the recessed portion 22 of the lower die is transferred to form the lower crimping part 114a, and the shape of the recessed portion 32 of the upper die is transferred to form the upper crimping part 114b. The central convex portion 22a of the lower die abuts a portion of the lower crimping part 114a, and the portion is largely recessed to form a concave lower crimping portion 114c. Similarly, the central convex portion 32a of the upper die abuts a portion of the upper crimping part 114b, and the portion is largely recessed to form a concave upper crimping portion 114d.

[0051] Furthermore, the concave lower crimping portion 114c and the concave upper crimping portion 114d each have a bottom surface 114e and a front inner wall surface 114f and a rear inner wall surface 114g that oppose each other in the longitudinal direction. The front inner wall surface 114f and the rear inner wall surface 114g are inclined so that their distance from each other in the longitudinal direction gradually decreases from a main surface of the lower crimping part 114a or the upper crimping part 114b to the bottom surface 114e. A corner where the front inner wall surface 114f meets the bottom surface 114e is defined here as a first corner 114h, and a corner where the rear inner wall surface 114g meets the bottom surface 114e is defined as a second corner 114i.In addition, an inclination angle of the front inner wall surface 114f with respect to the vertical axis AX from the first corner 114h and the inclination angle of the rear inner wall surface 114g with respect to the vertical axis AX from the second corner 114i are each defined as the angle θ2 of the concave portion.

[0052] In the crimping part 114, the core wire 102, which is a bundled body of a plurality of wires, is crimped into the insertion opening 112a by being held between the lower crimping part 114a and the upper crimping part 114b, so that the core wire 102 is in close contact with the crimp terminal 110, thereby ensuring an electrical conduction path.

[0053] Fig. 11 is a graph showing a relationship of a voltage drop at the crimping part 114 to the notch angle θ1 as electric power of the electric wire 100 attached to a terminal in Example 1. In Fig. 11, the horizontal axis represents the notch angle θ1 (degrees), and the vertical axis represents the ratio when, at a notch angle θ1 of 20°, the voltage drop is 1.0. Under the following various conditions, the voltage drop at the crimping part 114 was measured by changing the notch angle θ1, and the values ​​shown in Fig. 11 measurement results presented were obtained.

[0054] The electric wire 101 in Example 1 includes the core wire 102 comprising a plurality of soft copper wires and having a wire diameter of φ0.32 mm. The conductor size of the core wire 102 is 40 sq (conductor cross-sectional area: 39.73 mm 2 Note: “sq” is a unit of measurement for the thickness of an electrical wire according to the Japanese Industrial Standards (JIS).

[0055] A main material of the crimp terminal 110 in Example 1 is oxygen-free copper. A copper / silver plating is applied to the crimp terminal 110 as a base, and a silver plating is applied on top. The thickness of the crimp forming part 112 is 2.2 mm.

[0056] Further, in the lower die 14 and the upper die 16 used in the manufacture of the terminal-attached electric wire 100 in Example 1, the conditions regarding the shapes of the recessed portion 22 of the lower die and the recessed portion 32 of the upper die as recessed portions are as follows: the recess length L is 8.0 mm, the recess width W is 3.0 mm, and the recess height H is 2.0 mm.

[0057] First, as a result of a first measurement in Example 1, when the notch angle θ1 is 20°, that is, when the angle θ2 of the concave portion at the crimping part 114 is approximately 20°, the voltage drop is judged to be within an acceptable range of the electric performance of the electric wire 100 attached to a terminal. Here, the lower the voltage drop ratio compared to 1.0, the better the electric performance is judged, and the higher the voltage drop ratio compared to 1.0, the more insufficient the electric performance is judged.

[0058] Further, when the notch angle θ1 is 30°, that is, when the angle θ2 of the concave portion at the crimping part 114 is approximately 30°, the voltage drop ratio is 0.9 as a result of a second measurement in Example 1. The ratio is lower than 1.0, and it is judged that the electrical performance of the electric wire 100 attached to a terminal is good.

[0059] Further, when the notch angle θ1 is 45°, that is, when the angle θ2 of the concave portion in the crimping part 114 is approximately 45°, the voltage drop ratio is 1.7 as a result of a third measurement in Example 1. The ratio is larger than 1.0, and it is judged that the electric performance of the electric wire 100 attached to a terminal is insufficient.

[0060] It is therefore desirable that, for the electric performance of the terminal-attached electric wire 100 in Example 1, the notch angle θ1 with respect to the voltage drop in the crimping part 114 is in the range of 20° or more and 30° or less.

[0061] Fig. 12 is a graph showing a relationship of a voltage drop at the crimping part 114 to the notch angle θ1 as electric power of the electric wire 100 attached to a terminal in Example 2. In Fig. 12, the horizontal axis represents the notch angle θ1 (degrees) and the vertical axis represents a ratio of the voltage drop. The voltage drop is 1.0 at a notch angle θ1 of 20° under conditions similar to those in Fig. 11. Under the following different conditions, the voltage drop at the crimping part 114 was measured, with the notch angle θ1 set to 20°, and the voltage drop shown in Fig. 12 measurement results shown were obtained.

[0062] The electric wire 101 in Example 2 includes the core wire 102 comprising a plurality of soft copper wires and having a diameter of φ0.32 mm. The conductor size of the core wire 102 is 95 sq (conductor cross-sectional area: 96.27 mm 2 ).

[0063] A main material of the crimp terminal 110 in Example 2 is tough pitch copper. A copper / silver plating is applied to the crimp terminal 110 as a base, and a silver plating is applied on top. The thickness of the crimp forming part 112 is 2.0 mm.

[0064] In the lower die 14 and the upper die 16 used in the manufacture of the terminal-attached electric wire 100 in Example 2, the conditions regarding the shape of the recessed portion 22 of the lower die and the recessed portion 32 of the upper die as recessed portions are as follows: the recess length L is 11.60 mm; the recess width W is 3.95 mm; and the recess height H is 2.55 mm.

[0065] As a result of a measurement in Example 2, a voltage drop ratio of 0.09 is obtained when the notch angle θ1 is 20°, that is, when the angle θ2 of the concave portion at the crimping part 114 is approximately 20°. This ratio is lower than 1.0 in Example 1, and it is judged that the electrical performance of the electrical wire 100 attached to a terminal is good.

[0066] Therefore, with respect to the voltage drop at the crimping part 114, the electric performance of the electric wire 100 attached to a terminal in Example 2 satisfies the condition that the notch angle θ1 is preferably in the range of 20° or more, and 30° or less, which is assumed in Example 1.

[0067] Fig. 13 is a graph showing a relationship of a voltage drop at the crimping part 114 to the notch angle θ1 as electric power of the electric wire 100 attached to a terminal in Example 3. In Fig. 13, the horizontal axis represents the notch angle θ1 (degrees) and the vertical axis represents a ratio of the voltage drop. The voltage drop is 1.0 at a notch angle θ1 of 20° under conditions similar to those in Fig. 11. Under the following different conditions, the voltage drop at the crimping part 114 was measured, with the notch angle θ1 set to 20°, and the voltage drop shown in Fig. 13 measurement results presented were obtained.

[0068] The electric wire 101 in Example 3 includes the core wire 102 comprising a plurality of wires made of soft copper and having a diameter of φ0.80 mm. The conductor size of the core wire 102 is 40 sq.

[0069] Note that the crimp terminal 110 in Example 3 is the same as the crimp terminal 110 in Example 1. In addition, the lower die 14 and the upper die 16 used in manufacturing the terminal-attached electric wire 100 in Example 3 are the same as those used in manufacturing the terminal-attached electric wire 100 in Example 1.

[0070] As a result of a measurement in Example 3, a voltage drop ratio of 0.08 is obtained when the notch angle θ1 is 20°, that is, when the angle θ2 of the concave portion at the crimping part 114 is approximately 20°. This ratio is lower than 1.0 in Example 1, and it is judged that the electrical performance of the electrical wire 100 attached to a terminal is good.

[0071] Therefore, the electric performance of the terminal-attached electric wire 100 in Example 3 with respect to the voltage drop at the crimping part 114 satisfies the condition that the notch angle θ1 is preferably in the range of 20° or more and 30° or less, which is assumed in Example 1.

[0072] Next, a description will be given of the actions of the crimping tool 10, the method of manufacturing the terminal-attached electric wire 100, and the terminal-attached electric wire 100.

[0073] The crimping tool 10 according to the present embodiment includes the lower die 14 and the upper die 16 for crimping the crimp forming part 112 of the crimp terminal 110 to the electrical wire 101 when the lower die 14 and the upper die 16 are brought close to each other in the vertical direction. The lower die 14 and the upper die 16 each have a rectangular parallelepiped shape with a cross section on a horizontal plane defined in a longitudinal direction aligned with an axial direction of the crimp forming part 112 and in a width direction perpendicular to the longitudinal direction.

[0074] The lower die 14 includes the lower die recessed portion 22 provided in the lower concave portion 21 and having the lower die central convex portion 22a protruding in a crimping direction. The lower die concave portion 21 is formed on the lower die surface 20a aligned in the crimping direction and contacts the crimp forming part 112 along the longitudinal direction. The lower die 14 has the lower die concave portion 23 adjacent to one end of the lower die recessed portion 22 in the width direction and extending from the lower die surface 20a in a direction opposite to the crimping direction. Further, the lower die 14 has the lower die convex portion 24 adjacent to the other end of the lower die recessed portion 22 in the width direction and protruding from the lower die surface 20a of the lower die in the crimping direction.

[0075] The upper die 16 includes the upper die recessed portion 32 provided in the upper die concave portion 31 and having the upper die central convex portion 32a protruding in the crimping direction. The upper die concave portion 31 is formed on the upper die surface 30a aligned in the crimping direction and contacts the crimp forming part 112 in the longitudinal direction. The upper die 16 has the upper die convex portion 33 adjacent to one end of the upper die recessed portion 32 in the width direction and extending from the upper die surface 30a in a direction opposite to the crimping direction. Further, the upper die 16 has the upper die convex portion 34 adjacent to the other end of the upper die recessed portion 32 in the width direction and protruding from the upper die surface 30a in the crimping direction.

[0076] In the lower die 14, the lower die central convex portion 22a of the lower die recessed portion 22 has the upper end surface 22c and the front wall surface 22d and the rear wall surface 22e, which are opposite to each other in the longitudinal direction. Here, an end edge where the front wall surface 22d meets the upper end surface 22c is defined as the first end edge 22f, and an end edge where the rear wall surface 22e meets the upper end surface 22c is defined as the second end edge 22g. The inclination angle of the front wall surface 22d with respect to the vertical axis AX from the first end edge 22f and the inclination angle of the rear wall surface 22e with respect to the vertical axis AX from the second end edge 22g are each defined as the notch angle θ1. The notch angle θ1 is in a range of 20° or more and 30° or less. The notch angle θ1 in the upper die 16 is defined similarly.

[0077] As shown above, the vertical direction corresponds to the Z direction, the longitudinal direction corresponds to the X direction, and the width direction corresponds to the Y direction. Furthermore, the crimping direction of the lower die 14 corresponds to the Z direction, and the crimping direction of the upper die 16 corresponds to the direction opposite to the Z direction.

[0078] First, according to the crimping tool 10, when the lower die 14 and the upper die 16 are closest to each other, the recessed portion 22 of the lower die and the recessed portion 32 of the upper die compress the crimp forming part 112 in the Y direction to form the crimp part 114 while being held between the convex portion 24 of the lower die and the convex portion 34 of the upper die. At this point, the convex portion 24 of the lower die and the convex portion 34 of the upper die limit the plastic deformation of the crimp forming part 112 due to expansion in the Y direction on their outer surfaces, so that the occurrence of burrs in the crimp part 114 can be prevented.

[0079] In addition, the notch angle θ1 of the lower die 14 and the notch angle θ1 of the upper die 16 in the crimping tool 10 are in the range of 20° or more and 30° or less. Therefore, as shown with reference to the diagrams in the Fig. 11 to 13, the terminal-attached electric wire 100 manufactured using the crimping tool 10 can reduce a voltage drop at the crimping part 114 when actually used as a product.

[0080] As described above, according to the present embodiment, it is possible to provide a crimping tool 10 that improves the electrical performance of the electrical wire 100 attached to a terminal.

[0081] The method for manufacturing the terminal-attached electric wire 100 according to the present embodiment is a method for manufacturing the terminal-attached electric wire 100 by crimping the crimp forming part 112 of the crimp terminal 110 to the electric wire 101. The manufacturing method includes the step of inserting a part of the electric wire 101 into the crimp forming part 112 and the step of holding the crimp forming part 112, into which a part of the electric wire 101 is inserted, with a crimping die having a lower die and an upper die. The crimping die is the crimping die 10 according to the above-described embodiment.

[0082] According to the manufacturing method, the terminal-attached electric wire 100 is manufactured using the crimping tool 10, so that the terminal-attached electric wire 100 having improved electrical performance can be provided.

[0083] Furthermore, the terminal-attached electric wire 100 according to the present embodiment includes the crimping part 114 formed by holding the crimping forming part 112 of the crimping terminal 110, into which a part of the electric wire 101 is inserted, with the crimping tool 10 including the lower die 14 and the upper die 16. The crimping part 114 includes the concave lower crimping portion 114c into which a part of the convex shape of the lower die 14 is transferred, and the concave upper crimping portion 114d into which a part of the convex shape of the upper die 16 is transferred. The concave lower crimping portion 114c and the concave upper crimping portion 114d each have the bottom surface 114e and the front inner wall surface 114f and the rear inner wall surface 114g that are opposite to each other in the longitudinal direction aligned with the axial direction of the crimp forming part 112.A corner where the front inner wall surface 114f meets the bottom surface 114e is referred to as the first corner 114h, and a corner where the rear inner wall surface 114g meets the bottom surface 114e is referred to as the second corner 114i. The inclination angle of the front inner wall surface 114f with respect to the vertical axis AX from the first corner 114h and the inclination angle of the rear inner wall surface 114g with respect to the vertical axis AX from the second corner 114i are each defined as the angle θ2 of the concave portion. The angle θ2 of the concave portion is then in the range of 20° or more and 30° or less.

[0084] For example, according to the terminal-attached electric wire 100, the angle θ2 of the concave portion of the crimping part 114 is in the range of 20° or more, and 30° or less when the crimping tool 10 is used. Therefore, as described with reference to the diagrams in FIGS. Fig.11 to 13, the electrical performance of the terminal-attached electrical wire 100 can be improved when used as a product because the voltage drop at the crimping part 114 can be reduced.

[0085] In the above description, the crimping tool 10 used for the terminal crimping device 1 is exemplified, but the structure or shape of the crimping tool 10 can also be used for crimping tools.

[0086] Although the present invention has been described above with reference to the embodiment, the present invention is not limited to this, and the configuration of the parts may be replaced by any configuration having a similar function as long as it falls within the scope of the claims. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2022-42683 A

[0003] JP 2022

[0004] JP 42683 A

[0004]

Claims

[1] Crimping tool (10) comprising a lower die (14) and an upper die (16) for crimping a crimp forming part (112) of a crimp terminal (110) to an electric wire (101) when the lower die (14) and the upper die (16) are brought close to each other in a vertical direction; wherein the lower die (14) and the upper die (16) each have the shape of a rectangular parallelepiped, with a cross section on a horizontal plane defined in a longitudinal direction aligned with an axial direction of the crimp forming part (112) and in a width direction perpendicular to the longitudinal direction; wherein the lower die (14) and the upper die (16) each comprise: a recessed portion (22, 32) provided in a concave portion (21, 31) and having a central convex portion (22a, 32a) protruding in a crimping direction, the concave portion (21, 31) being formed on a die surface (20a, 30a) aligned in the crimping direction and coming into contact with the crimp forming part (112) along the longitudinal direction; a concave portion (23, 33) adjacent to one end of the recessed portion (22, 32) in the width direction and extending from the die surface (20a, 30a) in a direction opposite to the crimping direction; a convex portion (24, 34) adjacent to the other end of the recessed portion (22, 32) in the width direction and protruding from the die surface (20a, 30a) in the crimping direction; wherein the central convex portion (22a, 32a) of the recessed portion (22, 32) comprises an upper end surface (22c) and a front wall surface (22d) and a rear wall surface (22e) which are opposite to each other in the longitudinal direction; and wherein when an end edge at which the front wall surface (22d) meets the upper end surface (22c) is defined as a first end edge (22f), and an end edge at which the rear wall surface (22e) meets the upper end surface (22c) is defined as a second end edge (22g); and when an inclination angle of the front wall surface (22d) with respect to a vertical axis from the first end edge (22f) and an inclination angle of the rear wall surface (22e) with respect to a vertical axis from the second end edge (22g) are each defined as a notch angle (θ1), the notch angle (θ1) is in a range of 20° or more and 30° or less. [2] A method of manufacturing a terminal-attached electrical wire (100) having a crimp forming part (112) of a crimp terminal (110) crimped to an electrical wire (101), the method comprising: a step of inserting a part of the electric wire (101) into the crimping forming part (112); a step of holding the crimping forming part (112) into which a part of the electric wire (101) is inserted with a crimping tool comprising a lower die (14) and an upper die (16); and wherein the crimping tool is the crimping tool (10) according to claim 1. [3] Electrical wire (100) attached to a terminal, comprising: a crimping part (114) formed by holding a crimping forming part (112) into which a part of an electric wire (101) is inserted with a crimping tool (10) comprising a lower die and an upper die (16); wherein the crimping part (114) has a concave lower crimping area (114c) into which a convex shape of a part of the lower die (14) is transferred, and a concave upper crimping area (114d) into which a convex shape of a part of the upper die (16) is transferred; wherein the concave lower crimping portion (114c) and the concave upper crimping portion (114d) each have a bottom surface (114e) and a front inner wall surface (114f) and a rear inner wall surface (114g) which are opposite to each other in a longitudinal direction aligned with the axial direction of the crimp forming part (112); wherein, when a corner where the front inner wall surface (114f) meets the bottom surface (114e) is set as a first corner (114h), and a corner where the rear inner wall surface meets the bottom surface (114e) is set as a second corner (114i); and when an inclination angle of the front inner wall surface (114f) with respect to a vertical axis (AX) from the first corner (114h) and an inclination angle of the rear inner wall surface (114g) with respect to the vertical axis (AX) from the second corner (114i) are defined as an angle (θ2) of a concave portion, the angle (θ2) of the concave portion is in the range of 20° or more and 30° or less.

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