JP6782150B2 - Manufacturing method of electric wire with terminal - Google Patents

Description

The present invention relates to, for example, a method for manufacturing an electric wire with a terminal used in an automobile or the like.

Conventionally, in the fields of automobiles, OA equipment, home appliances and the like, electric wires made of copper-based materials having excellent electrical conductivity have been used as power lines and signal lines. In particular, in the field of automobiles, the performance and functionality of vehicles are rapidly increasing, and the number of various electric devices and control devices mounted on vehicles is increasing. Therefore, along with this, the number of electric wires with terminals used tends to increase.

On the other hand, as environmental problems are attracting attention, weight reduction of automobiles is required. Therefore, an increase in weight due to an increase in the amount of wire harness used becomes a problem. For this reason, lightweight aluminum electric wires are attracting attention in place of the conventionally used copper wires.

Here, a connection terminal is used when connecting such electric wires or at a connection portion of equipment or the like. However, even in the case of an electric wire with a terminal using an aluminum electric wire, copper having excellent electrical characteristics may be used for the terminal portion for the sake of reliability of the connecting portion and the like. In such a case, the aluminum electric wire and the copper terminal are joined and used.

However, when dissimilar metals are brought into contact with each other, so-called electrolytic corrosion may occur due to the difference in standard electrode potential. In particular, since the standard electrode potential difference between aluminum and copper is large, corrosion on the electrically base aluminum side progresses due to the influence of water scattering and dew condensation on the contact portion. For this reason, the connection state between the electric wire and the terminal at the connection portion becomes unstable, and there is a risk that the electrical resistance will increase due to the increase in contact resistance and the decrease in wire diameter, and further, the disconnection will occur, resulting in malfunction or malfunction of the electrical components. is there.

Therefore, a method of covering the connection portion between the electric wire and the terminal with a resin member has been proposed. However, if the resin member is applied with a thickness equal to or greater than a predetermined thickness in order to ensure corrosion resistance, the resin member may flow to the terminal body side before curing. If the resin member flows inside the terminal body, there is a risk of poor continuity at the connection between the terminals, poor insertion of the terminals, and the like. Therefore, a method of suppressing the flow of the resin member to the terminal body side has been proposed.

For example, when an opening is provided on the terminal body side and a resin member is applied, there is a method in which a blocking jig is inserted from the opening and the flow of the resin member is blocked by the blocking jig (Patent Document 1). ).

Further, when the resin member is applied, there is a method of locally irradiating the end portion of the anticorrosion countermeasure portion on the terminal body side with ultraviolet rays to accelerate the curing of the resin member and suppress the flow of the resin member (patented). Document 2).

Japanese Unexamined Patent Publication No. 2011-233328 JP 2015-153717

However, the method using a damming jig as in Patent Document 1 can be applied only to a special terminal having an opening. In addition, since it is necessary to insert and remove a damming jig that is not normally used at the time of manufacturing, the manufacturing process becomes complicated.

Further, as in Patent Document 2, in order to locally irradiate ultraviolet rays, it is necessary to arrange a shielding plate or the like having a slit in the irradiation portion, and the range of applicable devices and the terminal size are limited. Further, since the flow of the resin is not always constant, the effect of preventing the flow of the resin varies widely.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a method for manufacturing an electric wire with a terminal, which can prevent a resin member from flowing to a terminal body by a simple method.

In order to achieve the above-mentioned object, the present invention is a method for manufacturing an electric wire with a terminal in which a coated conductive wire and a terminal are connected. The coated conductive wire includes a coated portion and a conductive wire exposed from the tip of the coated portion. In the terminal, the terminal body and the crimping portion are connected via a transition portion, and the crimping portion includes a wire crimping portion to which the lead wire is crimped and a coated crimping portion to which the covering portion is crimped. A first resin coating step of applying a resin member on the bottom surface of the transition portion, and a first resin curing step of curing the resin member applied in the first resin coating step to form a flow stop. In the first resin coating step , at least on the crimping portion side of the flow stop, from the end of the conducting wire crimping portion on the terminal body side to the end of the covering crimping portion on the conducting wire crimping portion side. It is provided with a second resin coating step of applying a resin member made of the same resin material as the resin member to be coated, and a second resin curing step of curing the resin member applied in the second resin coating step. This is a characteristic method for manufacturing an electric wire with a terminal.

In the second resin coating step, the resin member may be coated by inclining the terminal so that the terminal body faces diagonally upward.

In this case, in the second resin coating step, a straight line connecting the upper surface position of the end portion of the lead wire crimping portion on the coated crimping portion side and the upper surface position of the end portion of the coated crimping portion on the lead wire crimping portion side. It is desirable to incline the terminal body so that is in the range of horizontal ± 10 °.

It is desirable that the flow stop is formed at a position separated from the lead wire crimping portion.

It is desirable that the height of the flow stop is 1/2 or more of the height of the wire crimping portion.

The viscosity of the resin member applied in the second resin coating step may be lower than the viscosity of the resin member applied in the first resin coating step.

In this case, the temperature of the resin member applied in the second resin coating step may be higher than the temperature of the resin member coated in the first resin coating step.

According to the present invention, first, by forming a flow stop in the transition portion by the resin member, the resin member flows to the terminal body side when the resin member covering the lead wire or the like is applied in the second resin coating step. Can be prevented. At this time, the flow stop can be formed with the amount of the resin member forming the flow stop portion being sufficiently smaller than the amount of the resin member required for anticorrosion applied in the second resin coating step.

Further, in the second resin coating step, the flow of the resin member to the terminal body side can be suppressed by tilting the terminal body side diagonally upward.

At this time, by setting the inclination angle of the terminal to an appropriate range, it is possible to prevent the resin member from excessively flowing to the coated lead wire side, and to more reliably cover the lead wire and the lead wire crimping portion with the resin member.

Further, by forming the flow stop at a position away from the tip of the lead wire, the flow of the resin applied in the second resin coating step can be efficiently suppressed.

Further, if the height of the flow stop is equal to or higher than a predetermined value, the flow of the resin applied in the second resin coating step can be efficiently suppressed.

Further, by relatively increasing the viscosity of the resin member applied in the first resin coating step, it is possible to efficiently form a flow stop having a predetermined height. Further, by making the viscosity of the resin member applied in the second resin coating step relatively low, the resin member can be efficiently permeated into the inside and the back surface of the lead wire.

In this case, by raising the temperature of the resin member applied in the second resin coating step higher than the temperature of the resin member coated in the first resin coating step, the viscosity can be changed even if the same resin member is used. be able to.

According to the present invention, it is possible to provide a method for manufacturing an electric wire with a terminal, which can prevent a resin member from flowing to a terminal body by a simple method.

The perspective view which shows the electric wire 10 with a terminal. The cross-sectional view which shows the electric wire 10 with a terminal. (A) is a diagram showing a manufacturing process of the electric wire 10 with a terminal, and (b) is an enlarged view of the vicinity of the flow stop 19. (A) and (b) are diagrams showing the manufacturing process of the electric wire 10 with terminals.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing an electric wire 10 with a terminal, and FIG. 2 is a cross-sectional view. Note that FIG. 1 is a perspective view of a part of the resin member 17. The terminal-attached electric wire 10 is configured by connecting the terminal 1 and the coated lead wire 11. The terminal 1 is an open barrel type, and a copper alloy such as copper or brass or one plated with tin or the like is used. A covered lead wire 11 is connected to the terminal 1.

The coated lead wire 11 includes a lead wire 13 which is an aluminum wire or an aluminum alloy wire, and a covering portion 15 which covers the lead wire 13. That is, the coated lead wire 11 includes a covered portion 15 and a lead wire 13 exposed from the tip thereof. The lead wire 13 is, for example, a stranded wire in which a plurality of strands are twisted together.

The terminal 1 is configured by connecting the terminal body 3 and the crimping portion 5 via the transition portion 4. The transition portion 4 located between the crimping portion 5 and the terminal body 3 opens upward.

The terminal body 3 is formed by forming a plate-shaped material having a predetermined shape into a tubular body having a rectangular cross section. The terminal body 3 has an elastic contact piece formed by folding a plate-shaped material into a rectangular cylinder. The terminal body 3 is connected by inserting a male terminal or the like from the front end portion. In the following description, an example is shown in which the terminal body 3 is a female terminal that allows insertion of an insertion tab (not shown) such as a male terminal. In the present invention, the detailed shape of the terminal body 3 is shown. Is not particularly limited. For example, instead of the female terminal body 3, for example, a male terminal insertion tab may be provided.

The crimping portion 5 is a portion to be crimped to the coated lead wire 11, and has a barrel shape having a substantially U-shaped cross section perpendicular to the longitudinal direction of the terminal 1. The crimping portion 5 of the terminal 1 includes a wire crimping portion 7 that crimps the lead wire 13 exposed from the coated wire 15 to the tip end side of the coated wire 11 and a coated crimping portion 9 that crimps the coated portion 15 of the coated wire 11.

A part of the inner surface of the wire crimping portion 7 is provided with serrations (not shown) in the width direction (direction perpendicular to the longitudinal direction). By forming the serrations in this way, when the lead wire 13 is crimped, the oxide film on the surface of the lead wire 13 is easily broken, and the contact area with the lead wire 13 can be increased.

At the tip of the coated lead wire 11, the covering portion 15 is peeled off, and the inner lead wire 13 is exposed. The coated portion 15 of the coated conducting wire 11 is crimped by the coated crimping portion 9 of the terminal 1. Further, the lead wire 13 exposed by peeling off the covering portion 15 is crimped by the lead wire crimping portion 7. In the wire crimping portion 7, the wire 13 and the terminal 1 are electrically connected. The end face of the covering portion 15 is located between the covering crimping portion 9 and the lead wire crimping portion 7.

In the present invention, at least the lead wire 13 exposed from the covering portion 15 is covered with the resin member 17. That is, the lead wire crimping portion 7 and the coated crimping portion 9 are covered with the resin member 17, and the lead wire 13 is not exposed to the outside by the resin member 17. The resin member 17 is, for example, an ultraviolet curable resin such as silicone acrylate, urethane acrylate, or acrylic acrylate.

Further, a flow stop 19 is formed on the upper surface of the transition portion 4. That is, the flow stop 19 is a protrusion provided on the bottom surface of the transition portion 4. The flow stop 19 is formed over the width direction of the transition portion 4. The flow stop 19 is made of resin, and is made of the same material as, for example, the resin member 17. The function of the flow stop 19 will be described later.

Next, a method of manufacturing the electric wire 10 with terminals will be described. First, the coated lead wire 11 and the terminal 1 are connected by crimping. Next, as shown in FIG. 3A, a resin member is applied (arrow A in the figure) on the bottom surface of the transition portion 4 (first resin coating step). At this time, it is desirable that the resin member is formed over the entire width of the transition portion 4. For example, the resin member may be applied to the center of the transition portion 4 in the width direction to spread the resin member over the entire width, or the resin member may be applied to a plurality of places in the width direction.

Here, in the present invention, coating the resin member means a method of bringing a droplet formed on the supply portion of the resin member into contact with the target portion, or ejecting (dropping) the droplet of the resin member from the supply portion to the target. It shall include all methods for obtaining a state in which the resin member is attached to the target portion, such as a method for attaching the resin member to the portion. For example, the resin member may be applied to the target portion with a jet dispenser or a mechanical dispenser.

Next, the resin member coated in the first resin coating step is irradiated with ultraviolet rays to be cured to form a flow stop 19 (first resin curing step). When the resin member is other than the ultraviolet curable resin, the resin member is cured by appropriately using a method such as heat.

FIG. 3B is an enlarged view of the vicinity of the flow stop 19 of FIG. 3A. The flow stop 19 is formed at a position separated from the lead wire crimping portion 7 (or the tip of the lead wire 13 exposed from the lead wire crimping portion 7). That is, a gap (D in the figure) is formed between the flow stop 19 and the wire crimping portion 7 (or the tip of the wire 13 exposed from the wire crimping portion 7) in the longitudinal direction of the terminal 1. By forming the gap in this way, it is possible to form a resin pool of the resin member to be applied after this.

Further, it is desirable that the height of the flow stop 19 (C in the figure) is ½ or more of the height of the wire crimping portion 7 (B in the figure). If the height of the flow stop 19 is too low, the blocking effect of the resin member described later becomes small.

Next, as shown in FIG. 4A, the terminal 1 is tilted so that the terminal body 3 faces diagonally upward. At this time, the straight line (straight line E in the figure) connecting the upper surface position of the end portion of the wire crimping portion 7 on the covering crimping portion 9 side and the upper surface position of the end portion of the covering crimping portion 9 on the lead wire crimping portion 7 side is horizontal. It is desirable to incline the terminal body 3 so that it is in the range of ± 10 °.

With the terminal 1 tilted, the resin member 17 is applied to the crimping portion 5 side (for example, near the tip of the conducting wire 13) with respect to the flow stop 19 (arrow F in the figure). At this time, the resin member 17 tries to flow to both sides at the same time as the coating, but the flow stop 19 blocks the flow of the resin member 17 to the terminal body 3 side. Further, since the resin member 17 flows in the gap between the flow stop 19 and the wire crimping portion 7 (or the tip of the wire 13 exposed from the wire crimping portion 7), the resin can be reliably applied to the end surface of the wire 13. At the same time, it is possible to prevent the resin member 17 from flowing to the terminal body 3 side beyond the flow stop 19.

Further, as shown in FIG. 4B, the resin member 17 is applied so that the entire lead wire 13 exposed from the covering portion 15 is covered (second resin coating step). That is, in the second resin coating step, the resin member 17 is sequentially applied from at least the end of the wire crimping portion 7 on the terminal body 3 side to the end of the covering crimping portion 9 on the wire crimping portion 7 side (arrow G in the drawing). Will be done. At this time, the thickness of the resin member 17 to be applied at this time is adjusted so that the thickness required for exhibiting the anticorrosion performance (for example, 0.2 mm or more) can be secured.

In the second resin coating step, the coating position of the resin member 17 does not have to be performed in order from the tip end side of the lead wire 13. Finally, the resin member 17 may be formed from the end of the wire crimping portion 7 on the terminal body 3 side to the end of the covering crimping portion 9 on the wire crimping portion 7 side.

Here, by inclining the terminal 1 and applying the resin member 17, the resin member 17 can also be applied to the end face side of the lead wire 13 and the end face side of the covering portion 15. Further, it is possible to prevent the resin member 17 from flowing to the terminal body 3 side. Further, by setting the inclination angle of the terminal 1 to a range in which the straight line E is horizontal ± 10 °, it is possible to prevent the resin member 17 from excessively flowing toward the coated lead wire 11.

It is desirable that the viscosity of the resin member applied in the second resin coating step is lower than the viscosity of the resin member applied in the first resin coating step. It is desirable that the flow stop 19 is formed so that the length of the terminal 1 in the longitudinal direction is as short as possible and the height is equal to or higher than a predetermined height. Therefore, the viscosity of the resin member applied in the first resin coating step is preferably high. On the other hand, in order to reliably cover the lead wire 13 and the like, the resin member applied in the second resin coating step preferably penetrates into the gap and the back side of the lead wire 13 and wraps around. Therefore, it is desirable that the viscosity of the resin member applied in the second resin coating step is low.

In this case, the resin member applied in the first resin coating step and the resin member applied in the second resin coating step may be different materials having different viscosities, but may be the same material. For example, by raising the temperature of the resin member applied in the second resin coating step higher than the temperature of the resin member coated in the first resin coating step, the viscosity of the resin member applied in the second resin coating step is increased. Can be lowered.

Next, the inclination of the terminal 1 is restored, and the resin member 17 coated in the second resin coating step is irradiated with ultraviolet rays to cure the resin member 17 (second resin curing step). As described above, the electric wire 10 with a terminal is manufactured.

As described above, according to the present embodiment, since the resin member 17 covers the connection portion between the terminal 1 and the coated lead wire 11, the anticorrosion effect can be efficiently obtained. Further, by forming the flow stop 19, it is possible to prevent the resin member 17 covering the lead wire 13 and the like from flowing to the terminal body 3 side. At this time, it is not necessary to use other jigs or local ultraviolet irradiation, and it can be applied to other than special terminals and devices.

Further, by inclining the terminal 1 and applying the resin member 17, the flow of the resin member 17 to the terminal body 3 side can be suppressed more efficiently, and the end face side of the lead wire 13 and the end face of the covering portion 15 can be suppressed. The resin member 17 can also be efficiently applied to the side.

In the present embodiment, the terminal 1 is tilted in the second resin coating step, but if the flow of the resin member 17 to the terminal body 3 side can be stopped only by the flow stop 19, the terminal 1 is necessarily tilted. There is no need. In this case, the first resin coating step, the first resin curing step, the second resin coating step, and the second resin curing step can all be performed in the same posture.

Further, by changing the viscosity of the resin member constituting the flow stop 19 at the time of coating and the viscosity of the resin member at the time of coating in the second resin coating step, the flow stop 19 having a predetermined height can be efficiently formed. At the same time, the resin member 17 can be sufficiently penetrated into the lead wire 13.

In particular, the same resin member is provided in the first resin coating step and the second resin coating step by providing a heating portion in the resin member coating device and raising the temperature of the resin member at the time of coating only in the second resin coating step. And a coating device can be used. Therefore, the device and the like can be simplified.

Further, in the present embodiment, in the second resin curing step, the inclination of the terminal 1 is restored to cure the resin member 17, but the resin member 17 may be cured while the terminal 1 is inclined. By curing the resin member 17 while the terminal 1 is tilted, it is possible to more reliably suppress the resin member 17 covering the lead wire 13 and the like from flowing to the terminal body 3 side.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the technical scope of the present invention does not depend on the above-described embodiments. It is clear that a person skilled in the art can come up with various modifications or modifications within the scope of the technical ideas described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

1 ………… Terminal 3 ………… Terminal body 4 ………… Transition part 5 ………… Crimping part 7 ………… Lead wire crimping part 9 ………… Covered crimping part 10 ………… Wire with terminal 11 ………… Covered wire 13 ……… Lead wire 15 ……… Covering part 17 ……… Resin member 19 ……… Flow stop

Claims (7)

It is a method of manufacturing an electric wire with a terminal that connects a covered wire and a terminal.
The coated lead wire includes a coated portion and a conducting wire exposed from the tip of the coated portion.
The terminal has a terminal body and a crimping portion connected via a transition portion, and the crimping portion includes a wire crimping portion to which the lead wire is crimped and a coated crimping portion to which the covering portion is crimped. And
The first resin coating step of coating the resin member on the bottom surface of the transition portion, and
The first resin curing step of curing the resin member applied in the first resin coating step to form a flow stop, and
It is applied in the first resin coating step on the crimping portion side of the flow stop, at least from the end portion of the conducting wire crimping portion on the terminal body side to the end portion of the covering crimping portion on the conducting wire crimping portion side. The second resin coating process of applying a resin member made of the same resin material as the resin member
A second resin curing step of curing the resin member applied in the second resin coating step, and
A method for manufacturing an electric wire with a terminal, which comprises the above. The method for manufacturing an electric wire with a terminal according to claim 1, wherein in the second resin coating step, the terminal is tilted to coat the resin member so that the terminal body faces diagonally upward. In the second resin coating step, the straight line connecting the upper surface position of the end portion of the wire crimping portion on the coated crimping portion side and the upper surface position of the end portion of the coated crimping portion on the lead wire crimping portion side is horizontal ±. The method for manufacturing an electric wire with a terminal according to claim 2, wherein the terminal body is tilted so as to be in a range of 10 °. The method for manufacturing an electric wire with a terminal according to any one of claims 1 to 3, wherein the flow stop is formed at a position separated from the wire crimping portion. The method for manufacturing an electric wire with a terminal according to any one of claims 1 to 4, wherein the height of the flow stop is ½ or more of the height of the wire crimping portion. The invention according to any one of claims 1 to 5, wherein the viscosity of the resin member applied in the second resin coating step is lower than the viscosity of the resin member applied in the first resin coating step. How to manufacture electric wires with terminals. The method for manufacturing an electric wire with a terminal according to claim 6, wherein the temperature of the resin member applied in the second resin coating step is higher than the temperature of the resin member applied in the first resin coating step.

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