JP2006107882A - Manufacturing method of wire with terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform a good ultrasonic welding by restraining attenuation of ultrasonic vibration caused by a reflection wave generated by the difference of acoustic impedances between a terminal fitting and a layer of air. <P>SOLUTION: On the method of welding a core wire Wa at a terminal part of a wire W and a wire connection part 14 of the terminal fitting 11 by ultrasonic welding, a good ultrasonic welding can be performed by restraining attenuation of ultrasonic vibration by restraining the generation of reflection wave by arranging vibration absorbing means 16, 26, 36 absorbing vibration energy at the ultrasonic welding at a contact part 15 of the terminal fitting 11. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing an electric wire with a terminal, and more particularly, when joining an electric wire and a terminal metal fitting by ultrasonic welding, a loss of vibration energy in a welded portion is reduced so that good welding can be performed. It is.

Conventionally, there is one described in Patent Document 1 that uses ultrasonic welding as a method of joining the terminal fitting and the core of the electric wire. In general, in order to join a core wire and a terminal by ultrasonic welding, as shown in FIG. 5, first, the wire connection portion 3 of the terminal fitting 2 is placed on the anvil 1, and the wire W is placed on the upper surface of the wire connection portion 3. The core wire Wa exposed by peeling the terminal is placed. Next, the core wire Wa on the wire connection portion 3 is pressed by the welding tip 4 and ultrasonic vibration is applied so that the core wire Wa and the terminal fitting 2 are sandwiched between the anvil 1 and the core wire Wa is attached to the terminal fitting. It joins to the electric wire connection part 3 of 2. As shown in FIG.
JP 2000-20642 A

In the process of joining the core wire Wa and the terminal fitting 2 using ultrasonic welding as described above, the incident wave A of ultrasonic vibration added from the welding tip 4 to the terminal fitting 2 is the other end of the terminal fitting 2. However, there is a case where the reflected wave B is generated at the same time and the vibration energy of the incident wave A is canceled and attenuated. That is, as shown in the relationship diagram of FIG. 6A, since the difference in acoustic impedance between the contact portion 5 and the air layer 6 is large, a part of the incident wave A reaching the contact portion 5 is an air layer. 6 is dissipated as a transmitted wave C, but mostly returns as a reflected wave B from the contact portion 5 to the wire connection portion 3. When a phase shift occurs between the reflected wave B and the incident wave A, the vibration energy of the incident wave A is weakened by the reflected wave B as shown in FIG. It is thought that it occurs in the electric wire connection part 3.
As described above, since the vibration energy acting on the electric wire connection portion 3 is weakened by the reflected wave B, the bonding between the core wire Wa and the electric wire connection portion 3 may be insufficient.

  The present invention has been made in view of the above problems, and it is an object of the present invention to provide an ultrasonic welding method capable of minimizing the generation of reflected waves caused by the difference in acoustic impedance between the terminal fitting and the air layer. It is said.

In order to solve the above-mentioned problems, in the present invention, a core wire peeled off and exposed at the end portion of the electric wire, and an electric wire connecting portion for receiving the core wire are provided at one end and a contact portion with the mating terminal is provided at the other end. A method of manufacturing an electric wire with a terminal by ultrasonic welding in a state where the terminal fitting is sandwiched between an anvil and a welding tip,
A method of manufacturing an electric wire with a terminal, characterized in that a vibration absorbing means that suppresses the generation of reflected waves by absorbing vibration energy during ultrasonic welding is applied to the contact portion of the terminal metal fitting so as to perform ultrasonic welding. Is provided.

According to this method, since the vibration energy of the incident wave that reaches the contact portion from the wire connection portion of the terminal fitting can be effectively absorbed by the vibration absorbing means, the acoustic impedance between the contact portion and the air layer is reduced. It is possible to suppress the generation of reflected waves caused by a large difference.
In addition, as a terminal metal fitting which should weld a core wire, it can apply to various terminals, such as a female terminal, a male terminal, a ground terminal, a battery terminal.

Specifically, the vibration absorbing means comprises an elastic contact piece provided at the contact portion of the terminal fitting, and the elastic contact piece is formed separately from the terminal fitting main body and can swing relative to the main body. It is fitted and fixed in a stable state.
In this way, the elastic contact piece of the contact portion swings separately from the main body due to the vibration energy of the incident wave that has reached the contact portion from the wire connection portion of the terminal metal fitting. The vibration energy transmitted to the contact portion can be absorbed.

Further, the vibration absorbing means may be constituted by a pressing piece that elastically presses the contact portion of the terminal fitting against the anvil.
If comprised in this way, since the vibration energy of the incident wave which reached the contact part from the electric wire connection part of the terminal metal fitting is absorbed by the holding piece which elastically presses the contact part, generation of a reflected wave is effective. Can be suppressed.

Further, the vibration absorbing means comprises a step portion formed on the anvil so that the tip of the contact portion of the terminal fitting can be abutted, and a pressing means for elastically pressing the terminal fitting against the step portion. May be.
If it does in this way, the contact part of a terminal metal fitting will be in the state pressed firmly on the anvil via the step part. For this reason, most of the vibration energy of the incident wave from the wire connection part to the contact part is transmitted to the anvil, but the difference in acoustic impedance between the terminal fitting and the anvil is extremely small compared to the air layer. The vibration energy of the incident wave is absorbed by the anvil, so that the generation of the reflected wave can be effectively suppressed.

  As is clear from the above description, according to the method for manufacturing a terminal-attached electric wire of the present invention, good ultrasonic welding is performed by preventing attenuation of vibration energy at the electric wire connecting portion due to generation of reflected waves. be able to.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 2 show a first embodiment of the present invention, and ultrasonic welding is performed on a core wire Wa exposed by peeling off a terminal of an electric wire W on a terminal fitting 11 using an ultrasonic welding machine 10. The process which manufactures an electric wire with a terminal is shown. The ultrasonic welding machine 10 includes an anvil 12 on which the terminal fitting 11 is placed, and a welding tip 13 that faces the upper portion of the anvil 12 and sandwiches the terminal fitting 11 and the electric wire W between the anvil 12. The ultrasonic wave is applied to the terminal fitting 11 and the core wire Wa between the welding tip 13 and the anvil 12 to join them together.

In this embodiment, as shown to FIG. 1 (A), the terminal metal fitting 11 is equipped with the electric wire connection part 14 which should fix the core wire Wa in the end. The electric wire connecting portion 14 includes a flat bottom wall 14a and side walls 14b extending vertically upward from both sides of the bottom plate portion 14a and has a substantially U-shaped cross section. On the other hand, the other end of the terminal fitting 11 is provided with a box-shaped contact portion 15 for receiving a mating terminal (not shown), and an elastic contact that also serves as a vibration absorbing means that is separately formed in a mountain shape. A piece 16 is provided, and an electrical contact is obtained by elastically holding the mating terminal between the elastic contact piece 16 and the upper surface portion 15 a of the inner surface of the contact portion 15.
As shown in FIG. 1 (B), the elastic contact piece 16 has engaging projections 16a protruding at both ends of the base portion, while engaging holes 15b are formed on both side walls of the contact portion 15 so that the elastic contact piece 16 By fitting the engaging protrusion 16a, the elastic contact piece 16 is fixed to the main body 11a of the terminal fitting 11 so as to be slightly swingable.

  The electric wire W to be welded to the terminal fitting 11 is formed by covering a core wire Wa obtained by twisting a plurality of strands into a circular cross section with an insulating coating Wb made of synthetic resin, and the insulating coating Wb of the terminal portion is connected to the terminal fitting 11. The core wire Wa is exposed by peeling over a predetermined length necessary for joining to the core.

Next, the manufacturing method of the electric wire with a terminal by a 1st embodiment is explained.
As shown in FIG. 2 (A), the anvil 12 of the ultrasonic welder 10 is fixed to the base of the main body, and an accommodating portion 12a for accommodating and positioning the electric wire connecting portion 12 of the terminal fitting 11 on the upper surface portion. It is recessed. The welding tip 13 has a block shape having a width that allows entry into the electric wire connection portion 12 of the terminal fitting 11, and can be operated in the vertical direction opposite to the upper portion of the anvil 12. The lower surface of the welding tip 13 is a pressing surface 13 a against the core wire 31, and the core wire Wa is compressed between the pressing surface 13 a and the bottom wall 14 a of the electric wire connection portion 14, and between the core wire Wa and the electric wire connection portion 14. Ultrasonic vibration is applied.

  First, as shown in FIG. 2A, the core wire Wa exposed from the end of the electric wire W is placed in the electric wire connecting portion 14 of the terminal fitting 11 accommodated in the accommodating portion 12 a of the anvil 12. At this time, the welding tip 13 of the ultrasonic welding machine 10 stands by at the raised position above the core wire Wa. Next, as shown in FIG. 2 (B), when the welding tip 13 is lowered toward the anvil 12, the core wire Wa is crushed by the anvil 12 and compressed between the bottom wall 14a and at the same time from the welding tip 13 Sonic vibration is applied. As a result, the core wire Wa gradually increases in temperature due to frictional heat and softens, and is joined to the bottom wall 14 b of the terminal fitting 11.

  When the incident wave acting on the wire connecting portion 14 by the application of the ultrasonic vibration is transmitted from the contact portion 15 at the tip to the air layer, the difference in acoustic impedance between the two becomes large, so that the reflected wave becomes a reflected wave. There is a component returned to. Since this reflected wave returns from a position away from the wire connecting portion 14, the phase is shifted from the incident wave, so that the vibration energy of the incident wave acting on the wire connecting portion 14 may largely cancel. In this embodiment, since the elastic contact piece 16 provided in the contact portion 15 is a separate component and is fitted and fixed so as to be swingable with respect to the main body 11a, the vibration energy of the incident wave transmitted to the contact portion 15 is obtained. As a result of the resonance of the elastic contact piece 16, much of the vibration energy transmitted to the air layer is absorbed. For this reason, generation | occurrence | production of the reflected wave resulting from the difference in the acoustic impedance between the contact part 15 and an air layer can be suppressed effectively, Therefore The loss of the energy of the ultrasonic vibration with respect to the electric wire connection part 14 is made the minimum. Therefore, good ultrasonic welding can be performed.

3A to 3C show a second embodiment of a method for manufacturing a terminal-attached electric wire.
A presser piece 26 that elastically presses the contact portion 25 at the tip of the terminal fitting 21 against the anvil 22 is provided as a vibration absorbing means. The presser piece 26 is made of an elastic mountain-shaped plate-like member, and for example, supports the support member 22a erected on the upper surface of the anvil 22 via a support pin 26a projecting from its intermediate portion. is doing. In the normal state, the pressing piece 26 is supported in a state where the pressing portion 26 b at the tip elastically contacts the upper surface of the anvil 22 as shown in FIG. Further, the distal end portion of the pressing portion 26b is curved upward to form a guide portion 26c capable of receiving the terminal fitting 21. The terminal fitting 21 to be ultrasonically welded in the second embodiment is a male terminal or a ground terminal provided with a flat contact portion 25. Since other configurations are the same as those of the first embodiment, the same reference numerals are given and description thereof is omitted.

Next, the manufacturing method of the electric wire with a terminal by a 2nd embodiment is explained.
2A, the contact portion 25 of the terminal fitting 21 is inserted between the pressing portion 26b and the upper surface of the anvil 22 through the guide portion 26c, as shown in FIG. 2B. The contact piece 25 is elastically pressed and held toward the anvil 22 by the presser piece 26. Next, the core wire Wa of the electric wire W is arranged in the electric wire connecting portion 14. Then, as shown in FIG. 2C, the welding tip 13 is moved downward to apply ultrasonic vibration between the core wire Wa and the wire connection portion 14, thereby ultrasonically bonding the two.

  In this embodiment, since the contact portion 25 is held elastically pressed by the presser piece 26 toward the anvil 22, the presser piece 26 resonates due to the vibration energy of the incident wave transmitted to the contact portion 25. As a result, much of the vibration energy transmitted to the air layer is absorbed. For this reason, generation | occurrence | production of the reflected wave resulting from the difference of the acoustic impedance between the contact part 25 and an air layer can be suppressed effectively, and favorable ultrasonic welding can be performed.

4 (A) and 4 (B) show a third embodiment of a method for manufacturing a terminal-attached electric wire.
As the vibration absorbing means, a contact part 35 at the tip of the terminal fitting 31 is formed with a step part 32a formed on the anvil 32, and a pressing means 36 that elastically presses the contact part 35 against the step part 32a. The stepped portion 32a has a shape that can accept the tip surface of the contact portion 35 of the terminal fitting 31 in a contact state. On the other hand, the pressing means 36 includes a pressing piece 36 a that is elastically pressed by a piston or the like that presses toward the contact portion 35 from the wire connection portion 14 side of the terminal fitting 31. The terminal fitting 31 to be ultrasonically welded in the third embodiment may be a box-shaped female terminal, a flat male terminal, a ground terminal, or the like. Since other configurations are the same as those of the first embodiment, the same reference numerals are given and description thereof is omitted.

Next, the manufacturing method of the electric wire with a terminal by a 3rd embodiment is explained.
As shown in FIG. 4A, the contact portion 35 of the terminal fitting 31 is fitted on the step portion 32 a of the anvil 32 and is disposed on the upper surface of the anvil 32. Next, by pressing the terminal fitting 31 toward the contact portion 35 from the wire connecting portion 14 side via the pressing piece 36a, the contact portion 35 is elastically pressed against the stepped portion 32a. In this state, the core wire Wa of the wire W is attached. It arrange | positions in the electric wire connection part 14. FIG. Then, as shown in FIG. 4B, the welding tip 13 is moved down to apply ultrasonic vibration between the core wire Wa and the wire connection portion 14, thereby ultrasonically bonding the two.

  In the present embodiment, since the contact portion 35 is held in a state of being pressed by the pressing piece 36a toward the step portion 32a of the anvil 32, the vibration energy of the incident wave transmitted to the contact portion 35 passes through the step portion 32a. Is transmitted to the anvil 32. Since the difference in acoustic impedance between the terminal fitting 31 and the anvil 32 is extremely small compared to the difference between the terminal fitting 31 and the air layer, the generation of reflected waves due to the difference in acoustic impedance is effectively suppressed. Therefore, good ultrasonic welding can be performed.

  In each of the above embodiments, the electric wire to be ultrasonically welded to the terminal fitting is not limited to a general copper electric wire, but can be similarly applied to an aluminum electric wire. Similarly, as a material of the terminal fitting, a general copper alloy is used. The present invention can be similarly applied to aluminum terminals and other metal terminals.

1A and 1B show a first embodiment of a method of manufacturing a terminal-attached electric wire according to the present invention, in which FIG. 1A is an exploded perspective view of a terminal fitting and an electric wire to be connected to the terminal fitting, and FIG. . (A) (B) is sectional drawing which shows the ultrasonic welding process of 1st Embodiment. (A)-(C) are sectional drawings which show the ultrasonic welding process of 2nd Embodiment. (A) (B) is sectional drawing which shows the ultrasonic welding process of 3rd Embodiment. It is a figure which shows a prior art example. (A) is a figure which shows the relationship of the acoustic impedance of a terminal metal fitting and an air layer, (B) is a figure which shows the relationship of an incident wave, a reflected wave, and a synthetic wave.

Explanation of symbols

11, 21, 31 Terminal fitting 11a Main body 12, 22, 32 Anvil 13 Welding tip 14 Electric wire connection part 15, 25, 35 Contact part 16 Elastic contact piece (vibration absorbing means)
26 Presser piece (vibration absorbing means)
32a Step (vibration absorbing means)
36 Pressing means (vibration absorbing means)
W Electric wire Wa Core wire

Claims (4)

An anvil and a welding tip include a core wire exposed by peeling off a terminal portion of an electric wire, and a terminal fitting provided at one end with a wire connection portion that receives the core wire and a contact portion with a mating terminal at the other end. A method of manufacturing an electric wire with a terminal by ultrasonic welding in a state of being sandwiched between,
A method of manufacturing an electric wire with a terminal, characterized in that a vibration absorbing means that suppresses the generation of reflected waves by absorbing vibration energy during ultrasonic welding is applied to the contact portion of the terminal metal fitting so as to perform ultrasonic welding. .   The vibration absorbing means comprises an elastic contact piece provided at the contact portion of the terminal fitting, and the elastic contact piece is molded separately from the main body of the terminal fitting and is fitted in a swingable manner with respect to the main body. The manufacturing method of the electric wire with a terminal of the above-mentioned Claim 1 currently fixed.   The method of manufacturing an electric wire with a terminal according to claim 1, wherein the vibration absorbing means includes a pressing piece that elastically presses the contact portion of the terminal fitting against the anvil.   The vibration absorbing means comprises a step portion formed on the anvil so that a tip of a contact portion of the terminal fitting can be abutted, and a pressing means for elastically pressing the terminal fitting against the step portion. The manufacturing method of the electric wire with a terminal of description.

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