Electric wire with terminal and method for manufacturing the same

Abstract

To provide an electric wire with a terminal in which electrical performance is improved by minimizing a change in the shape of the terminal, and to provide a method of manufacturing the same.SOLUTION: The terminal-equipped electrical wire includes the electrical wire 10 that has the conductor 11 and the electrical wire coating member 12 that covers the conductor 11, and the terminal 20 that is connected to the conductor 11 of the electrical wire 10, and the terminal 20 has the conductor crimping portion 22 that comes into contact with the conductor 11, and the projection 41 that comes into contact with the conductor 11 and extends from the conductor crimping portion 22 toward the electrical wire coating member 12.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an electric wire with a terminal and a method for manufacturing the same. [Background technology]

[0002] A wide variety of electronic devices are installed in automobiles, and wire harnesses are installed to transmit power, control signals, etc. to the electronic devices. A wire harness includes a plurality of electric wires and connectors, and is connected to an electronic device or another wire harness by fitting the connector to the connector of the electronic device or the connector of another wire harness. The electric wires with terminals that make up such wire harnesses generally include electric wires and terminal fittings attached to the ends of the electric wires.

[0003] In order to improve productivity and delivery efficiency of terminals, a chain terminal is widely known in which a plurality of terminals are connected together and are separated from a carrier (a chain portion) when in use. Conventionally, a chain terminal has been known that has a linearly formed chain portion and a plurality of terminals arranged in a direction perpendicular to the longitudinal direction of the chain portion (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-37547 Summary of the Invention [Problem to be solved by the invention]

[0005] As a means for improving the electrical performance of a terminal crimped to an insulated electric wire, changing the shape of the terminal or the shape of the crimping mold has been considered. However, in the case of existing terminals such as those described in Patent Document 1, changing the shape is difficult due to the limitations of the mold.

[0006] The present invention has been made in view of the problems inherent in the prior art, and an object of the present invention is to provide an electric wire with a terminal and a method for manufacturing the same, which improves electrical performance while minimizing changes to the shape of the terminal. [Means for solving the problem]

[0007] An electric wire with a terminal according to an embodiment of the present invention comprises an electric wire having a conductor and a wire covering material covering the conductor, and a terminal connected to the conductor of the electric wire, wherein the terminal has a conductor crimping portion that contacts the conductor and a protrusion that contacts the conductor and extends from the conductor crimping portion toward the wire covering material.

[0008] A method for manufacturing an electric wire with terminal according to an embodiment of the present invention includes a chained terminal having a plurality of terminals, a linearly formed chain portion, and a plurality of connecting portions extending from one widthwise side of the chain portion toward the plurality of terminals in a direction perpendicular to the lengthwise direction of the chain portion and formed integrally with the conductor crimping portion of the terminal, the method comprising the steps of: cutting the connecting portions of the chained terminal in the widthwise direction to form protrusions, thereby separating the terminals; and removing the wire coating material of the electric wires to expose the conductors, and crimping the exposed conductors with the conductor crimping portion of the terminal. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide an electric wire with a terminal and a method for manufacturing the same, in which electrical performance is improved while changes to the shape of the terminal are kept to a minimum. [Brief explanation of the drawings]

[0010] [Figure 1] 3 is a plan view of a chained terminal in the manufacturing method of the electric wire with terminal according to the embodiment. FIG. [Figure 2] FIG. 2 is a perspective view of a chained terminal in the manufacturing method of the electric wire with terminal according to the embodiment. [Figure 3] 3 is an enlarged view of a connecting portion of the chain terminal in FIG. 2. [Figure 4] 1 is a perspective view showing a state of a terminal before an electric wire is connected to the terminal-attached electric wire obtained by the manufacturing method according to the present embodiment. FIG. [Figure 5A] 4 is an optical microscope photograph showing the upper surface side of the conductor crimping portion of the electric wire with terminal according to the present embodiment after the conductor has been crimped. [Figure 5B] 5B is an optical microscope photograph showing the bottom side of the conductor crimped portion in FIG. 5A. [Figure 6A] 5B is an optical microscope photograph showing a cross section taken along line AA in FIG. 5A. [Figure 6B] 5B is an optical microscope photograph showing a cross section of line BB in FIG. 5A. [Figure 7] FIG. 2 is a plan view of a loose terminal in an unfolded state in the electric wire with terminal according to the embodiment. [Figure 8] 1 is a plan view showing a state of loose terminals before electric wires are connected in an electric wire with terminal obtained by the manufacturing method according to the present embodiment. FIG. [Figure 9] 1 is a perspective view showing a state of loose terminals before electric wires are connected in an electric wire with terminal obtained by the manufacturing method according to the present embodiment. FIG. [Figure 10] 4 is a graph showing the relationship between the voltage drop ratio and the length of the projection in the electric wire with terminal according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] The electric wire with terminal according to the present embodiment will be described in detail below with reference to the drawings. Note that the dimensional proportions in the drawings are exaggerated for the sake of convenience and may differ from the actual proportions.

[0012] [Wire with terminals] The electric wire with terminal according to this embodiment will be described. The electric wire with terminal includes an electric wire 10 having a conductor 11 and a wire covering material 12 that covers the conductor 11, and a terminal 20 that is connected to the conductor 11 of the electric wire 10.

[0013] The material of the conductor 11 of the electric wire 10 can be a metal with high conductivity, such as copper, copper alloy, aluminum, or aluminum alloy. The surface of the conductor 11 can also be tin-plated.

[0014] The material of the wire coating material 12 that covers the conductor 11 can be a resin that ensures electrical insulation, such as a resin containing polyvinyl chloride (PVC) as a main component or an olefin-based resin. Specific examples of olefin-based resins include polyethylene (PE), polypropylene (PP), ethylene copolymers, and propylene copolymers.

[0015] The terminal 20 of the electric wire with terminal has a conductor crimping portion 22 that contacts the conductor 11, and a protrusion 41 that contacts the conductor 11 and extends from the conductor crimping portion 22 toward the wire covering material 12 side.

[0016] The material (terminal material) of the terminal 20 can be a metal with high conductivity, such as at least one of copper, copper alloy, stainless steel, tin-plated copper, tin-plated copper alloy, and tin-plated stainless steel. Also, at least one of gold-plated copper, copper alloy, and stainless steel may be used, or at least one of silver-plated copper, copper alloy, and stainless steel may be used. Preferably, the terminal 20 contains copper or a copper alloy.

[0017] The terminal 20 may include a terminal body 21 to which a mating terminal (not shown) is connected. The terminal body 21 may be, for example, a female type, and may have an electrical connection portion for connection to the mating terminal. Furthermore, the electrical connection portion may have a box-like appearance and may include a spring piece that engages with the mating terminal.

[0018] The terminal 20 has a conductor crimping portion 22 that contacts the conductor 11. The conductor crimping portion 22 of the terminal 20 is connected to the end portion of the electric wire 10 by crimping. When the conductor crimping portion 22 is connected to the end portion of the electric wire 10, an electric wire with a terminal is obtained. Specifically, the conductor crimping portion 22 contacts the conductor 11 that is exposed by removing the wire coating material 12 from the end portion of the electric wire 10. As shown in FIG. 4 , the conductor crimping portion 22 has a bottom plate portion and a pair of conductor crimping pieces that are formed to extend upward, and is formed in a generally U-shaped cross section. The conductor crimping portion 22 is configured to be bent inward to wrap around the conductor 11 of the electric wire 10 and thereby crimp it.

[0019] The terminal 20 in the electric wire with terminal has a protrusion 41 that contacts the conductor 11 and extends from the conductor crimping portion 22 toward the wire covering material 12. The protrusion 41 is formed continuously from the bottom plate portion of the conductor crimping portion 22. However, since the terminal 20 has such a structure that includes the protrusion 41, it is preferable that the terminal 20 does not have a covering crimping portion that contacts the wire covering material 12 of the electric wire 10.

[0020] As shown in Fig. 4 , the electric wire with terminal is manufactured by inserting the end portion of the electric wire 10 into the conductor crimping portion 22 of the terminal 20, and then pressing the conductor crimping portion 22 and the end portion of the electric wire 10 to deform the conductor crimping portion 22. Then, as shown in Figs. 5A , 5B , 6A , and 6B , the pair of conductor crimping pieces of the conductor crimping portion 22 are bent inward to encase the conductor 11, thereby crimping the conductor 11 so that it is in close contact with the upper surface of the bottom plate portion of the conductor crimping portion 22. In this way, the terminal 20 and the electric wire 10 are crimped and connected, and an electric wire with terminal is obtained. Furthermore, as shown in Figs. 5B and 6B , when the conductor 11 of the electric wire 10 is crimped with the conductor crimping portion 22, the protrusion 41 comes into contact with the conductor 11 of the electric wire 10.

[0021] Because the terminal 20 has the protrusion 41, a floor-like flat portion that is longer than the top surface by length L1 is provided on the bottom surface of the rear end of the conductor crimping portion 22. The rear end of the conductor crimping portion 22 refers to the end of the electric wire 10 on the wire covering material 12 side. When the conductor 11 of the electric wire 10 is crimped with the conductor crimping portion 22, the force with which the terminal 20 presses the electric wire 10, i.e., the contact pressure from the terminal 20 to the electric wire 10, is efficiently transmitted. Therefore, when the terminal 20 is produced from a chain terminal as described below, there is no need to change the shape of an already used chain terminal, such as by increasing the width of the conductor crimping portion 22 of the terminal 20, in order to improve electrical performance, and there is no need to change the terminal mold.

[0022] The length of the protrusion 41 is preferably 0.5 mm or more and 1.0 mm or less. By making the length of the protrusion 41 0.5 mm or more, it is possible to increase the contact pressure from the terminal 20 to the electric wire 10 and improve electrical performance. Furthermore, by making the length of the protrusion 41 1.0 mm or less, it is possible to prevent adverse effects when placing the terminal.

[0023] The terminals 20 may be produced as loose terminals controlled to the above-described terminal shape. Alternatively, the terminals 20 may be produced by cutting the linking portions of a chain terminal in which multiple terminals are connected to a chain portion, and separating the terminals, as described below.

[0024] As described above, the electric wire with terminal according to this embodiment includes an electric wire 10 having a conductor 11 and a wire covering material 12 covering the conductor 11, and a terminal 20 connected to the conductor 11 of the electric wire 10. The terminal 20 has a conductor crimping portion 22 that contacts the conductor 11 and a protrusion 41 that contacts the conductor 11 and extends from the conductor crimping portion 22 toward the electric wire 10. Because the terminal 20 has the protrusion 41, when the conductor 11 is crimped with the conductor crimping portion 22, contact pressure from the terminal 20 to the electric wire 10 is efficiently transmitted. Therefore, there is no need to significantly change the shape of a terminal that is already in use in order to improve electrical performance. From the above, the electric wire with terminal according to this embodiment can provide an electric wire with improved electrical performance while minimizing changes to the shape of the terminal.

[0025] [Manufacturing method for electric wire with terminal] Next, a method for manufacturing the electric wire with terminal according to this embodiment will be described. In the method for manufacturing the electric wire with terminal, the chain terminal 1A may be manufactured first.

[0026] 1 and 2, the chained terminal 1A has a plurality of terminals 20 and a linearly formed linking section 30. The chained terminal 1A also has a plurality of connecting sections 40 that extend from one widthwise side of the linking section 30 toward the plurality of terminals 20 in a direction perpendicular to the lengthwise direction of the linking section 30 and are formed integrally with the conductor crimping sections 22 of the terminals 20.

[0027] The chained terminal 1A is produced by pressing a metal plate. During this pressing, a hole 31 may be formed in the chain portion 30 for each terminal 20. For example, the claws of a press machine (not shown) may be inserted into the hole 31 to support the chain portion 30. The chained terminal 1A may be stored in a factory or the like with the chain portion 30 wound up like a reel.

[0028] The method for manufacturing an electric wire with terminal according to this embodiment includes a step (step (a)) of cutting the connecting portion 40 of the chained terminal 1A in the width direction to form the protrusion 41, thereby separating the terminal 20. The manufacturing method also includes a step (step (b)) of crimping the conductor 11 exposed by removing the wire coating material 12 of the electric wire 10 with the conductor crimping portion 22 of the terminal 20. Each step will be described below.

[0029] [Process (a)] Step (a) is a step of cutting the connecting portion 40 of the chained terminal 1A in the width direction to form the protrusion 41, and separating the terminal 20. FIG. 3 is an enlarged view of the connecting portion 40 of the chained terminal 1A. When separating the terminal 20 from the chained terminal 1A, conventionally, the separation portion (cutoff tab) from the chained terminal 1A was controlled to be as short as possible, so the terminal 20 was cut at the rear end of the terminal 20 (conductor crimping portion 22), i.e., at cutting position C2. On the other hand, in the manufacturing method according to this embodiment, the connecting portion 40 is cut at cutting position C1 to secure a portion of length L1, and then the terminal 20 is separated, thereby producing a terminal 20 having the protrusion 41.

[0030] [Step (b)] Step (b) is a step of crimping the conductor 11 exposed by removing the wire coating 12 of the electric wire 10 with the conductor crimping portion 22 of the terminal 20. The end portion of the electric wire 10 is inserted into the conductor crimping portion 22 of the terminal 20 obtained in step (a), and the conductor 11 of the electric wire 10 is placed on the upper surface of the bottom plate portion of the conductor crimping portion 22. Then, the conductor crimping portion 22 and the end portion of the electric wire 10 are pressed together to deform the conductor crimping portion 22. Furthermore, the pair of conductor crimping pieces of the conductor crimping portion 22 are bent inward to encase the conductor 11, thereby crimping the conductor 11 so that it is in close contact with the upper surface of the bottom plate portion of the conductor crimping portion 22. In this way, the terminal 20 and the electric wire 10 are crimped and connected, and a terminal-attached electric wire is obtained in a state in which the protrusions 41 are in contact with the conductor 11.

[0031] As described above, the manufacturing method of the electric wire with terminal of this embodiment may be manufactured from the chained terminal 1A. This manufacturing method includes a step of cutting the connecting portion 40 of the chained terminal 1A in the width direction to form the protrusion 41, and then separating the terminal 20. This manufacturing method also includes a step of removing the wire coating 12 of the electric wire 10 to expose the conductor 11, and crimping the exposed conductor 11 with the conductor crimping portion 22 of the terminal 20. When separating the terminal 20 from the chained terminal 1A, the cutting position can be adjusted to produce a terminal 20 having the protrusion 41. By having the protrusion 41 in the terminal 20, contact pressure from the terminal 20 to the electric wire 10 is efficiently transmitted when the conductor 11 is crimped with the conductor crimping portion 22. Therefore, when manufacturing the terminal 20 from the chained terminal 1A, it is not necessary to change the shape of an already used chained terminal, such as by increasing the width of the conductor crimping portion 22 of the terminal 20, or to change the terminal mold, in order to improve electrical performance. As described above, according to the manufacturing method of the electric wire with terminal of the present embodiment, it is possible to provide a manufacturing method of the electric wire with terminal that improves electrical performance while minimizing changes to the shape of the terminal.

[0032] Furthermore, the electric wire with terminal according to this embodiment may be manufactured from loose terminals 1B. Descriptions of the same parts as in the case of manufacturing from the chained terminals 1A described above will be omitted or simplified.

[0033] 7 to 9, the loose terminals 1B are produced by controlling the terminal shape so that protrusions 41 with length L2 are formed. Therefore, the manufacturing method for producing an electric wire with terminal from the loose terminals 1B does not require the above-mentioned step (a), and includes step (b), i.e., a step of removing the wire coating material 12 from the electric wire 10 to expose the conductor 11 and crimping it with the conductor crimping portion 22 of the terminal 20.

[0034] The loose terminal 1B in the terminal-attached wire, like the terminal 20 described above, has a conductor crimping portion 22 that contacts the conductor 11, and a protrusion 41 that contacts the conductor 11 and extends from the conductor crimping portion 22 toward the wire coating material 12.

[0035] The shape of the loose terminal 1B (terminal 20) is not particularly limited, and may include a terminal body 21 having a hole 25 penetrating from the front to the back surface. A fastening member such as a bolt or a screw is inserted into this hole 25, and the loose terminal 1B (terminal 20) is fastened to a connected portion of various devices, etc., and fixed thereto for electrical connection. The shape of the hole 25 formed in the loose terminal 1B (terminal 20) is also not particularly limited, and may be, for example, male, female, or LA (round).

[0036] The loose terminal 1B (terminal 20) is crimped to the conductor 11 with the conductor crimping portion 22 in the same manner as in step (b) above, thereby crimping and connecting the loose terminal 1B (terminal 20) to the electric wire 10, and an electric wire with terminal is obtained in which the protrusion 41 is in contact with the conductor 11. Because the loose terminal 1B (terminal 20) has the protrusion 41, when the conductor 11 is crimped with the conductor crimping portion 22, contact pressure is efficiently transmitted from the terminal 20 to the electric wire 10. Therefore, there is no need to significantly change the shape of a terminal that is already in use in order to improve electrical performance. From the above, even when manufactured from the loose terminal 1B, the electric wire with terminal of this embodiment can provide an electric wire with improved electrical performance with minimal change in the shape of the terminal. [Example]

[0037] The present embodiment will be described in more detail below with reference to examples, but the present embodiment is not limited to these examples.

[0038] (Preparation of test samples) Chained terminals were prepared, and terminals with different protrusion lengths were fabricated by adjusting the cutting position in the above-mentioned step (a). Specifically, three lengths of protrusions were prepared: 0.1 mm, 0.5 mm, and 1.0 mm. Then, in step (b), the terminal and the electric wire were crimped and connected, and test samples of electric wires with terminals in contact with the conductor were obtained.

[0039] (Voltage drop ratio) The electrical performance of the terminal-attached wire was evaluated based on the voltage drop that occurred at the conductor crimped portion after the terminal was crimped. The voltage drop is thought to be caused mainly by contact resistance at the point where the conductor and the conductor crimped portion come into contact. Note that a lower voltage drop indicates better electrical performance.

[0040] The voltage drop value of the conductor crimped portion was calculated by measuring the voltage drop value of the terminal-attached electric wire and then subtracting the voltage drop value of the electric wire alone from the measured value. The voltage drop ratio was then calculated, assuming that the voltage drop value when the protrusion length was 0.1 mm was 1.0. Figure 10 is a graph showing the relationship between the voltage drop ratio and the length of the protrusion 41. The voltage drop ratio was 0.48 when the protrusion length was 0.5 mm and 0.46 when the protrusion length was 1.0 mm. These results demonstrate that the inclusion of protrusions in the terminal resulted in a terminal-attached electric wire with improved electrical performance.

[0041] Although the present embodiment has been described above, the present embodiment is not limited to this, and various modifications are possible within the scope of the gist of the present embodiment. [Explanation of symbols]

[0042] 1A chain terminal 10 Electric wire 11 Conductor 12 Wire sheathing material 20 terminals 22 Conductor crimping section 30 Chain section 40 Joint 41 Protrusion

Claims

1. an electric wire having a conductor and a wire coating material covering the conductor; a terminal connected to the conductor of the electric wire, The terminal includes a conductor crimping portion that contacts the conductor, and a protrusion that contacts the conductor and extends from the conductor crimping portion toward the wire coating material.

2. The electric wire with terminal according to claim 1 , wherein the length of the protrusion is 0.5 mm or more and 1.0 mm or less.

3. A method for manufacturing an electric wire with terminal according to claim 1 or 2, A plurality of the terminals; A linking portion formed in a straight line; a plurality of connecting portions extending from one side of the linking portion in the width direction toward the plurality of terminals in a direction perpendicular to the length direction of the linking portion and integrally formed with the conductor crimping portions of the terminals; In a chain terminal having cutting the connecting portion of the chained terminals in a width direction to form the protrusion portion, thereby separating the terminals; removing the wire coating from the electric wire to expose the conductor, and crimping the exposed conductor with the conductor crimping portion of the terminal.

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