JP2020184485A - Electric wire with terminal and method for inspecting the same - Google Patents

Abstract

To facilitate measurement of electric resistance.SOLUTION: With an electric wire 10 with a terminal, a terminal 40 is connected to an end section of an electric wire 20. The electric wire 20 has a core wire 22 that is a bundle of a plurality of element wires. The terminal 40 has an electric wire connecting section 42 and an adjacent section 44. The adjacent section 44 is formed in a flat plate shape so as to be continuous with the electric wire connecting section 42. The core wire 22 exposed at a front end of the wire 20 is connected to the electric wire connecting section 42. The core wire 22 connected to the electric wire connection section 42 has a welded section 26. The welded section 26 is ultrasonically welded to electric wire connecting section 42 and includes at least one roughened section 29 and at least one smooth section 32. The roughened section 29 has a roughened surface. A surface of the smooth section 32 is formed to be smoother than the roughened section 29 and flatter than the roughened section 29.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to an electric wire with a terminal and a method for inspecting an electric wire with a terminal.

For example, an electric wire with a terminal in which a terminal and a core wire of the electric wire are connected by ultrasonic welding is disclosed in Japanese Patent Application Laid-Open No. 2017-162635 (Patent Document 1 below). To bond a core wire and a terminal by ultrasonic welding, the core wire is bonded to the terminal by vibrating the welding horn at high frequency with the core wire and the terminal sandwiched between the welding horn and the anvil.

Here, in order for the high frequency vibration to act effectively on the core wire, it is important to prevent slipping between the welding horn and the core wire. Therefore, a non-slip groove is formed on the pressing surface of the welding horn, and the core wire is made to bite into the non-slip groove, that is, anti-slip is achieved by the so-called edge effect.

JP-A-2017-162635

The joint state between the terminal and the core wire is confirmed by measuring the electrical resistance between the terminal and the core wire. Here, as the electric resistance between the terminal and the core wire, it is preferable to measure the electric resistance between the terminal and the welded portion welded to the terminal. Further, in the measurement of the electric resistance between the terminal and the core wire, a pair of probes having a flat surface are brought into surface contact with the flat portion of the terminal and the flat portion of the welded portion, and the terminal and the welded portion are measured. Measure the electrical resistance between.

Here, in the case of the electric wire with a terminal as described above, it is possible to bring one probe into surface contact with the flat portion of the terminal. However, since the surface of the welded portion is in a rough state due to the edge effect of the non-slip groove, even when a probe having a flat surface is brought into contact with the rough surface of the welded portion, the probe and the welded portion may come into surface contact with each other. This is not possible and the measurement accuracy is reduced.

To measure the electrical resistance between the terminal and the weld, for example, the probe is brought into surface contact with the terminal and the terminal connected to the other end of the wire that is different from the end where the weld was formed. And measure the electrical resistance between the terminals. Then, a method of confirming the joint state by obtaining the resistance value between the terminal and the welded portion by subtracting the resistance value other than the portion to be measured from the measured resistance value can be considered.
However, when it is necessary to frequently inspect the joint state of the electric wire with a terminal, such as when the electric wire with a terminal is mass-produced, the work of measuring the electric resistance becomes complicated and the working time increases.

This specification discloses a technique that facilitates the measurement of electrical resistance.

The electric wire with a terminal of the present disclosure is an electric wire with a terminal in which a terminal is connected to an end portion of the electric wire, the electric wire has a core wire which is a bundle of a plurality of strands, and the terminal is a wire connecting portion. The adjacent portion is formed in a flat plate shape so as to be connected to the electric wire connecting portion, and the core wire exposed at the end of the electric wire is connected to the electric wire connecting portion. The core wire connected to the electric wire connection portion has an ultrasonically welded welded portion, and the welded portion has at least one rough surface portion and at least one smooth portion. The surface of the rough surface portion is rough, and the smooth portion has a smoother surface than the rough surface portion and is formed flatter than the rough surface portion.

According to the present disclosure, the measurement of electrical resistance can be facilitated.

FIG. 1 is a perspective view of an electric wire with a terminal according to the first embodiment. FIG. 2 is a front view of an electric wire with a terminal. FIG. 3 is a plan view of an electric wire with a terminal. FIG. 4 is a side view of an electric wire with a terminal. FIG. 5 is a plan view showing a state in which an electric wire and a terminal are ultrasonically welded. FIG. 6 is a perspective view of the welding horn viewed from diagonally below. FIG. 7 is a cross-sectional view showing a state in which the terminal and the electric wire are placed on the anvil, and is a cross-sectional view corresponding to the cross section of the line AA in FIG. FIG. 8 is a cross-sectional view taken along the line AA of FIG. FIG. 9 is a perspective view of the electric wire with a terminal according to the second embodiment. FIG. 10 is a plan view of an electric wire with a terminal. FIG. 11 is a cross-sectional view taken along the line BB of FIG. FIG. 12 is a perspective view of an electric wire with a terminal according to the third embodiment. FIG. 13 is a cross-sectional view in which the probe is brought into surface contact with the smooth portion, and is a cross-sectional view corresponding to the cross section of FIG. FIG. 14 is a perspective view of an electric wire with a terminal according to the fourth embodiment. FIG. 15 is a plan view of an electric wire with a terminal. FIG. 16 is a cross-sectional view in which the second probe is brought into surface contact with the smooth portion, and is a cross-sectional view corresponding to the cross section of the line CC of FIG. FIG. 17 is a cross-sectional view in which the third probe is brought into surface contact with the smooth portion, and is a cross-sectional view corresponding to the cross section of the line CC of FIG.

[Explanation of Embodiments of the present disclosure]
First, the embodiments of the present disclosure will be listed and described.

(1) An electric wire with a terminal whose terminal is connected to the end of the electric wire, the electric wire has a core wire which is a bundle of a plurality of strands, and the terminal has an electric wire connecting portion and an adjacent portion. The adjacent portion is formed in a flat plate shape so as to be connected to the electric wire connecting portion, and the core wire exposed at the end of the electric wire is connected to the electric wire connecting portion. The core wire connected to the portion has a welded portion that has been ultrasonically welded, and the welded portion has at least one rough surface portion and at least one smooth portion, and the rough surface portion is a surface. Is rough, and the surface of the smooth portion is smoother than the rough surface portion and is formed flatter than the rough surface portion.

One probe having a flat surface can be brought into surface contact with the smooth portion, and the other probe having a flat surface can be brought into surface contact with the adjacent portion. That is, the electrical resistance between the welded portion and the terminal can be easily measured. This makes it possible to easily inspect the joint state between the terminal and the electric wire.

(2) The sliding surface portion is formed at the tip end portion of the welded portion.
Since the smooth portion is formed at the tip of the welded portion, the position of the smooth portion can be easily specified. That is, the probe can be easily brought into surface contact with the smooth portion. As a result, the electrical resistance between the welded portion and the terminal can be easily measured.

(3) The rough surface portion is formed in a plurality of directions in the extending direction of the electric wire, and the smooth portion is formed between the adjacent rough surface portions.
Since the smooth portion is formed between the adjacent rough surface portions, the position of the smooth portion can be easily specified. Further, since the smooth portion for contacting the probe is formed between the rough surface portions of the welded portion, the length direction of the core wire in the welded portion is higher than that in the case where the smooth portion is separately formed at a position away from the rough surface portion. The size can be reduced.

(4) A pair of the smoothed portions are arranged on both sides in the width direction of the welded portion.
A pair of smoothing portions can be sandwiched between the probes to bring the smoothing portion and the probe into surface contact, or the probe can be slid after assembling the probe to the welded portion to bring the smoothing portion and the probe into surface contact. That is, the probe can be easily aligned with the smooth portion. This makes it easier to measure the electrical resistance between the weld and the terminal.

(5) The smooth portion is formed by recessing the welded portion toward the electric wire connecting portion, and the surface of the bottom portion of the smooth portion is smoother than the rough surface portion and is smoother than the rough surface portion. It is formed flat.
The probe can be inserted into the concave smooth portion to bring the probe into surface contact with the bottom of the smooth portion. That is, it is possible to easily align the probe with respect to the smooth portion. This makes it easier to measure the electrical resistance between the weld and the terminal.

(6) A method for inspecting an electric wire with a terminal having a terminal connected to the end of the electric wire. The electric wire has a core wire which is a bundle of a plurality of strands, and the terminal is adjacent to the electric wire connecting portion. The adjacent portion is formed in a flat plate shape so as to be connected to the electric wire connecting portion, and the electric wire connecting portion is connected to the core wire exposed at the end of the electric wire. The core wire connected to the electric wire connecting portion has a welded portion that has been ultrasonically welded, and the welded portion has at least one rough surface portion and at least one smooth surface portion, and the rough surface portion has at least one rough surface portion. The surface is rough, and the smooth portion is formed to be smoother than the rough surface portion and flatter than the rough surface portion, and the probe is brought into surface contact with each of the adjacent portion and the smooth portion. The joint state between the welded portion and the terminal is inspected.

One probe with a flat surface is brought into surface contact with a smooth surface, and the other probe with a flat surface is brought into surface contact with an adjacent portion so that the electrical resistance between the welded portion and the terminal can be easily measured. As a result, the joint state between the terminal and the electric wire can be easily inspected.
[Details of Embodiments of the present disclosure]
A specific example of the electric wire 10 with a terminal of the present disclosure will be described with reference to the following drawings. It should be noted that the present disclosure is not limited to these examples, and is indicated by the scope of claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

<Embodiment 1>
The first embodiment in the present disclosure will be described with reference to FIGS. 1 to 8.
As shown in FIGS. 1 to 4, the electric wire 10 with a terminal according to the present embodiment includes an electric wire 20 and a terminal 40 connected to an end portion of the electric wire 20. In the following description, the direction indicated by the arrow Z is the top, the direction indicated by the arrow Y is the rear, and the direction indicated by the arrow X is the right. Further, for a plurality of the same members, only one member may be designated with a reference numeral, and the other members may be omitted with reference numerals.

[Terminal 40]
The terminal 40 is formed by processing a conductive metal plate material. The terminal 40 of the present embodiment is formed in the shape of a rectangular plate having a long plan view in the front-rear direction.
The terminal 40 has an electric wire connecting portion 42 and an adjacent portion 44. The electric wire connecting portion 42 is a portion to which the core wire 22 of the electric wire 20 described later is connected. The adjacent portion 44 is a portion of the terminal 40 that is different from the electric wire connecting portion 42 adjacent to the electric wire connecting portion 42. The upper surfaces of the electric wire connecting portion 42 and the adjacent portion 44 are flat and smooth surfaces.

[Electric wire 20]
As shown in FIGS. 1 to 4, the electric wire 20 has a circular cross section and extends in the front-rear direction. The electric wire 20 includes a core wire 22 and an insulating coating 24. The core wire 22 is formed by twisting a plurality of conductive metal strands. The insulating coating 24 is made of an insulating synthetic resin that covers the outer periphery of the core wire 22. At the front end of the electric wire 20, the core wire 22 is exposed by peeling the insulating coating 24.
The portion of the core wire 22 exposed from the insulating coating 24 connected to the electric wire connecting portion 42 is a welded portion 26 welded by ultrasonic welding.

[Welded portion 26]
The welded portion 26 is welded to the electric wire connecting portion 42 by being sandwiched together with the terminal 40 between the anvil 81 described later and the welding horn 91 described later and ultrasonically vibrated. As shown in FIGS. 1 to 4, the welded portion 26 includes a high compression portion 27 and a low compression portion 30.

The high compression portion 27 has a main body portion 28 and a plurality of rough surface portions 29. The main body portion 28 is formed by being compressed into a semicircular cross section so that the cross-sectional area of the welded portion 26 is the smallest. In the main body 28, a plurality of strands of the core wire 22 are integrally formed by welding to form a semicircular cross section. Therefore, the surface of the main body 28 is a smooth curved surface in which the boundary between the strands is unknown.

The plurality of rough surface portions 29 are formed side by side on the upper surface of the main body portion 28 at intervals in the front-rear direction, which is the direction in which the electric wire 20 extends. In the high compression portion 27 of the present embodiment, three rough surface portions 29 are formed side by side in the front-rear direction.

The rough surface portion 29 is formed long in the left-right direction. The upper surface of the rough surface portion 29 is curved in the left-right direction along the main body portion 28. The rough surface portion 29 is formed by the core wire 22 biting into the holding groove 96 described later of the welding horn 91 when the welded portion 26 is welded. Therefore, the compressed state of the rough surface portion 29 is slightly relaxed as compared with the main body portion 28. As a result, the upper surface of the rough surface portion 29 has a clearer boundary between the strands than the main body portion 28. That is, the surface of the rough surface portion 29 is rougher than that of the main body portion 28.

The low compression section 30 is formed in a row in front of the high compression section 27. The low compression portion 30 is welded to a lower compression than the high compression portion 27, so that the cross-sectional area becomes larger toward the front as shown in FIG.

The low compression portion 30 has a connecting portion 31 and a smoothing portion 32. The smooth portion 32 is formed in a rectangular parallelepiped shape at the front end portion of the low compression portion 30. The upper surface of the smooth portion 32 is a flat surface where the boundary between the strands is unknown. That is, the smooth surface 32U of the smooth portion 32 is a smooth surface 32U formed to be smoother and flatter than the surface of the rough surface portion 29 in the high compression portion 27.

The connecting portion 31 is formed so as to be connected to the front end portion of the high compression portion 27 and to the rear end portion of the smoothing portion 32. The connecting portion 31 has a form in which the cross-sectional shape changes from a circular cross-sectional shape to a square cross-sectional shape from the high compression portion 27 to the smooth portion 32. Further, as shown in FIGS. 1, 3 and 4, the connecting portion 31 has a clearer boundary between the strands than the main body portion 28 and the smooth surface 32U. That is, the surface of the connecting portion 31 is rougher than that of the main body portion 28 and the smooth surface 32U.

This embodiment has the above-mentioned configuration, and subsequently, an example of a manufacturing process of the electric wire 10 with a terminal will be described.
The electric wire 10 with a terminal is manufactured by welding the terminal 40 and the electric wire 20 by an ultrasonic welding device 80.

[Ultrasonic Welding Device 80]
The ultrasonic welding apparatus 80 includes an anvil 81, a welding horn 91, and a pair of position holding portions 85.

The anvil 81 is fixed on the base 82 of the ultrasonic welding apparatus 80. The upper surface of the anvil 81 is formed flat so that the terminal 40 can be placed on it.
The welding horn 91 is formed in a block shape. The welding horn 91 is movable in the vertical direction with respect to the anvil 81 so as to sandwich the terminal 40 and the exposed core wire 22 together with the anvil 81 from both sides in the vertical direction.

The length dimension of the welding horn 91 in the front-rear direction is slightly shorter than the length dimension of the exposed core wire 22 in the front-rear direction.
A pair of recesses 92 are formed in the lower part of the front end of the welding horn 91. The pair of recessed portions 92 are formed to be recessed so as to approach each other from both left and right sides of the welding horn 91.

A welding recess 93 recessed upward is formed in the lower portion of the welding horn 91 so as to extend in the front-rear direction.
The portion of the weld recess 93 on the rear side of the region where the pair of recesses 92 is formed is the high pressure portion 95.

The high pressure portion 95 is formed so as to be recessed in a semicircular shape upward. A plurality of holding grooves 96 are formed in the inner portion (upper portion) of the high pressure portion 95 at intervals in the front-rear direction. In this embodiment, three holding grooves 96 are formed at intervals in the front-rear direction.

The holding groove 96 is formed so as to extend in the left-right direction along the inner surface of the high pressure portion 95. The core wire 22 bites into the holding groove 96 when the welding horn 91 descends toward the anvil 81.

In the welding recess 93, the portion on the front side of the high pressure portion 95 is a low pressure portion 97 arranged between the pair of recess portions 92. The inner portion of the low pressurizing portion 97 is a pressurizing surface 98 that is connected to an inner wall 92A extending in the vertical direction adjacent to the left and right rear in a pair of recessed portions 92.

The end of the pressure surface 98 on the high pressure portion 95 side is curved downward in an arc shape. Further, the pressurizing surface 98 becomes flat from the end on the high pressurizing portion 95 side toward the front, and the front end portion of the pressurizing surface 98 is a flat and smooth pressurizing flat surface 99.

The pair of position holding portions 85 are formed symmetrically. The pair of position holding portions 85 are arranged on both sides in the left-right direction with reference to the portion where the terminal 40 is placed in the anvil 81, and can be brought into contact with each other.

Each position holding portion 85 has a terminal holding portion 86 and an electric wire holding portion 88. The terminal holding portion 86 is formed so as to project toward the terminal 40. The electric wire holding portion 88 is formed so as to project toward the insulating coating 24 arranged behind the terminal 40.
Therefore, when the pair of position holding portions 85 approach each other, the terminals 40 placed on the anvil 81 are sandwiched and held by the pair of terminal holding portions 86 from both sides in the left-right direction. Further, the insulating coating 24 arranged behind the terminal 40 is sandwiched and held from both sides in the left-right direction by a pair of electric wire holding portions 88.

A horn insertion recess 89 is formed between the terminal holding portion 86 and the electric wire holding portion 88 in the position holding portion 85 so that the welding horn 91 can enter from above.

Therefore, when the welding horn 91 approaches the anvil 81 while the terminals 40 and the electric wires 20 are held by the pair of position holding portions 85, the low pressure portion 97 of the welding horn 91 is between the pair of terminal holding portions 86. The high pressurizing portion 95 enters the horn insertion recess 89 at the same time.

Subsequently, an example of a welding process for welding the electric wire 20 and the terminal 40 will be described.
First, the insulating coating 24 is peeled off at the front end of the electric wire 20 to expose the core wire 22. Next, the terminal 40 is placed on the anvil 81, and the exposed core wire 22 is arranged on the electric wire connecting portion 42 of the terminal 40.

Next, the pair of position holding portions 85 move in the left-right direction so as to approach each other. Then, the terminals 40 are held by the pair of terminal holding portions 86, and the insulating coating 24 of the electric wire 20 is held by the pair of electric wire holding portions 88.

When the electric wire 20 and the terminal 40 are held by the pair of position holding portions 85, the welding horn 91 is lowered, and the core wire 22 and the electric wire connecting portion 42 are sandwiched by the anvil 81 and the welding horn 91 from the vertical direction.

Here, in the process of lowering the welding horn 91, the welding recess 93 of the welding horn 91 covers the core wire 22 from above, and the core wire 22 is compressed in the high pressure portion 95 and the low pressure portion 97. Further, the core wire 22 is in a state of being bitten into the holding groove 96 of the high pressure portion 95. At this time, the pressure applied to the core wire 22 in the high pressurization section 95 and the low pressurization section 97 is larger in the high pressurization section 95 than in the low pressurization section 97.

Next, when ultrasonic vibration by the welding horn 91 is applied to the core wire 22, frictional heat is generated between the strands of the core wire 22, and the core wire 22 and the electric wire connecting portion 42 are welded and fixed. Along with this, a welded portion 26 is formed on the electric wire connecting portion 42.

Here, in the process of forming the welded portion 26, when the ultrasonic vibration of the welding horn 91 is applied to the core wire 22, the core wire 22 compressed by the high pressure portion 95 is formed as the high compression portion 27. Then, the surface of the main body 28 is formed on a smooth surface in which the boundary between the strands is unknown. Further, the core wire 22 compressed by the low pressure portion 97 is formed as the low compression portion 30. Then, the portion of the pressure surface 98 compressed by the pressure flat surface 99 is formed as a smooth portion 32 having a smooth smooth surface 32U in which the boundary between the strands is unknown.

On the other hand, the core wire 22 that bites into the holding groove 96 in the high pressure portion 95 is formed as a rough surface portion 29. Then, the surface of the rough surface portion 29 is not prepared because the core wire 22 bites into the holding groove 96, and the surface of the rough surface portion 29 becomes rough due to the edge effect of the holding groove 96. That is, the surface of the main body 28 and the smooth surface 32U of the smooth portion 32 are configured to be smoother than the surface of the rough surface portion 29. As described above, the electric wire 10 with terminals is completed.

Subsequently, the welded state of the completed electric wire 10 with terminals is inspected.

The welded state of the electric wire 10 with a terminal is confirmed by measuring the electric resistance between the terminal 40 and the welded portion 26 in the core wire 22.

The resistance measuring instrument R for measuring electrical resistance has a pair of probes P. The pair of probes P are formed in a columnar shape, each having a screening surface P1 at the tip.

The electrical resistance between the terminal 40 and the core wire 22 is measured by bringing the examination surface P1 into surface contact with the adjacent portion 44 of the terminal 40 and the welded portion 26 of the electric wire 20. Here, for example, when the portion of the probe P in contact with the examination surface P1 is rough or not flat, the examination surface P1 of the probe P cannot be brought into surface contact with the measurement location. It ends up. Then, the measurement accuracy of the electric resistance between the terminal 40 and the welded portion 26 is lowered, and the joint state between the terminal 40 and the electric wire 20 cannot be inspected.

As a countermeasure for this, for example, a method is conceivable in which terminals are connected to the rear end of the electric wire 20 by crimping, and the probe P is brought into surface contact with each terminal to measure the electrical resistance between the terminals. However, according to such a method, it is necessary to calculate the resistance value between the terminal and the welded portion by subtracting the resistance value other than the portion to be measured from the measured resistance value.
Therefore, when it is necessary to frequently inspect the joint state of the electric wire 10 with a terminal, such as when the electric wire 10 with a terminal is mass-produced, the measurement work of the electric resistance becomes complicated and the working time increases. Is a concern.

However, the terminal-attached electric wire 10 of the present embodiment is a terminal-attached electric wire 10 in which the terminal 40 is connected to the front end (end) of the electric wire 20, and the electric wire 20 is a core wire 22 which is a bundle of a plurality of strands. The terminal 40 has an electric wire connecting portion 42 and an adjacent portion 44. The adjacent portion 44 is formed in a flat plate shape so as to be connected to the electric wire connecting portion 42, and the core wire 22 exposed at the front end portion of the electric wire 20 is connected to the electric wire connecting portion 42 and is connected to the electric wire connecting portion 42. The core wire 22 is ultrasonically welded and has a welded portion 26. The welded portion 26 has at least one rough surface portion 29 and at least one smooth surface portion 32. The rough surface portion 29 has a rough surface, and the smooth portion 32 has a rough surface portion (upper surface). It is smoother than 29 and flatter than the rough surface portion 29.

Therefore, according to the present embodiment, as shown in FIG. 1, the examination surface P1 of one probe P is brought into surface contact with the smooth surface 32U of the smooth portion 32, and the other probe P is brought into surface contact with the adjacent portion 44. Can be done. Thereby, the electric resistance between the welded portion 26 and the terminal 40 can be easily measured. That is, the inspection of the joint state between the terminal 40 and the electric wire 20 can be easily performed.

Further, according to the present embodiment, the smooth portion 32 is formed at the tip end portion of the welded portion 26.
Since the smooth portion 32 is formed at the tip of the core wire 22, the position of the smooth portion 32 can be easily specified. As a result, the probe P can be easily brought into surface contact with the smooth portion 32, and the electrical resistance between the welded portion 26 and the terminal 40 can be measured more easily.

<Embodiment 2>
Next, the second embodiment will be described with reference to FIGS. 9 to 11.
The terminal-equipped electric wire 110 of the second embodiment has a modified shape of the welded portion 26 in the first embodiment, and the configuration, operation, and effect common to the first embodiment are duplicated, and thus the description thereof is omitted. To do. Further, the same reference numerals are used for the same configurations as in the first embodiment.

The welded portion 126 in the second embodiment, unlike the first embodiment, has only the high compression portion 127 as shown in FIGS. 9 and 10. The high compression section 127 has a main body section 128, a plurality of rough surface sections 29, and a smoothing section 132.

Similar to the first embodiment, the main body 128 is formed so that the cross-sectional area of the weld 126 is the smallest. In the main body 128, a plurality of strands in the core wire 22 are integrated by welding, and the front end portion and the rear end portion are formed in a semicircular cross section. Therefore, as shown in FIGS. 9 and 10, the surface of the main body 128 has a smooth curved surface in which the boundary between the strands is unknown.

The plurality of rough surface portions 29 are formed side by side on the upper surface of the main body portion 128 with an interval in the front-rear direction, which is the direction in which the electric wire 20 extends.

The smoothing portion 132 is formed between the rough surface portions 29 adjacent to each other in the front-rear direction in the main body portion 128, and is formed at the upper end portion of the main body portion 128. As shown in FIG. 11, the upper surface of the smoothing portion 132 is a rectangular smooth surface 132U that is long in the front-rear direction and extends straight in the left-right direction. The smooth surface 132U is a flat surface whose boundaries between the strands are unknown. That is, the smooth surface 32U of the present embodiment is also formed to be smoother and flatter than the surface of the rough surface portion 29.

Therefore, according to the present embodiment, the examination surface P1 of one probe P can be brought into surface contact with the smooth surface 132U of the smooth portion 132, and the other probe P can be brought into surface contact with the adjacent portion 44. As a result, the electrical resistance between the welded portion 126 and the terminal 40 can be easily measured, and the joint state between the terminal 40 and the electric wire 20 can be easily inspected.

Further, as shown in FIGS. 9 and 10, the smoothing portion 132 of the present embodiment is formed between the rough surface portions 29 adjacent to each other in the front-rear direction in the high compression portion 127, so that the position of the smoothing portion 132 can be determined. It can be easily identified.
By the way, for example, when a smooth portion is separately formed at a position away from the rough surface portion or a position different from the high compression portion (position in front of or behind the high compression portion), in addition to the length dimension of the high compression portion, The length dimension of the smooth portion is also required, and the size of the core wire in the welded portion in the length direction (front-back direction) becomes large.
However, in the present embodiment, the smooth portion 132 is formed between the rough surface portions 29 in the upper part of the high compression portion 127. That is, since it is not necessary to separately form a smooth portion at a position away from the rough surface portion or a position different from the high compression portion (position in front of or behind the high compression portion), the length dimension of the welded portion 126 in the front-rear direction can be adjusted. Can be miniaturized.

<Embodiment 3>
Next, the third embodiment will be described with reference to FIGS. 12 and 13.
The electric wire 210 with a terminal of the third embodiment has a larger wire diameter than the electric wire 20 of the first embodiment and has a modified shape of the welded portion 26, and has the same configuration, operation, and common configuration as that of the first embodiment. Since the effects are duplicated, the description thereof will be omitted. Further, the same reference numerals are used for the same configurations as in the first embodiment.

As shown in FIG. 12, the electric wire 220 in the third embodiment has a larger core wire 222 due to a larger number of strands than the first embodiment. Further, unlike the first embodiment, the welded portion 226 has only the high compression portion 227.

The high compression portion 227 has a main body portion 228, a plurality of rough surface portions 229, and a smoothing recess (an example of a “smoothing portion”) 232.
The main body portion 228 is formed so that the cross-sectional area of the welded portion 226 is the smallest. In the main body 28, a plurality of strands in the core wire 22 are integrated by welding, and are formed in a flat rectangular parallelepiped shape that is larger in the horizontal direction than in the vertical direction. As a result, the surface of the main body 228 is a flat surface whose boundaries between the strands are unknown. The horizontal length dimension of the main body portion 228 is set to be at least twice the horizontal length dimension of the main body portion 28 of the first embodiment.

The plurality of rough surface portions 229 are formed side by side on the upper surface of the main body portion 228 with an interval in the front-rear direction. Each rough surface portion 229 is formed so as to extend straight in the left-right direction along the upper surface of the main body portion 228. On the upper surface of the rough surface portion 229, the boundary of the strands is clearer than that of the main body portion 28, and the surface is rougher than that of the main body portion 28.

The smoothing recess 232 is formed between two rough surface portions 229 arranged in the front-rear direction. The smoothing recess 232 is formed in a bottomed concave shape that is recessed toward the electric wire connecting portion 42. As shown in FIGS. 12 and 13, the bottom of the smoothing recess 232 is a flat surface where the boundary between the strands is unknown. That is, the smooth surface 32U of the present embodiment is also a smooth surface 32U formed to be smoother and flatter than the surface of the rough surface portion 29.

Therefore, according to the present embodiment, as shown in FIG. 13, by inserting one probe P into the smoothing recess 232, the examination surface P1 of the probe P comes into surface contact with the smooth surface 232U at the bottom of the smoothing recess 232. Can be made to. As a result, the electrical resistance between the welded portion 26 and the terminal 40 can be easily measured by bringing the other probe P into surface contact with the adjacent portion 44. That is, the inspection of the joint state between the terminal 40 and the electric wire 20 can be easily performed.

<Embodiment 4>
Next, the fourth embodiment will be described with reference to FIGS. 14 to 17.
The terminal-equipped electric wire 310 of the fourth embodiment has a modified shape of the welded portion 26 in the first embodiment, and the configuration, operation, and effect common to the first embodiment are duplicated, and thus the description thereof will be omitted. To do. Further, the same reference numerals are used for the same configurations as in the first embodiment.

Unlike the first embodiment, the welded portion 326 in the fourth embodiment has only the high compression portion 327 as shown in FIGS. 14 and 15. The high compression portion 327 has a main body portion 328, a plurality of rough surface portions 29, and a smoothing portion 332.

Similar to the first embodiment, the main body portion 328 is formed so that the cross-sectional area of the welded portion 26 is the smallest. In the main body 328, a plurality of strands in the core wire 22 are integrated by welding, and the upper portion of the main body 328 is formed in an arc shape. As a result, the surface of the main body portion 328 is a smooth curved surface in which the boundary between the strands is unknown.

The plurality of rough surface portions 29 are formed on the upper surface of the main body portion 328 by arranging three thereof at equal intervals in the front-rear direction, which is the direction in which the electric wire 20 extends.

The smoothing portion 332 is formed between the rough surface portions 29 arranged at the front end portion and the rear end portion in the main body portion 328, and is formed on both sides of the main body portion 128 in the left-right direction. Therefore, the smoothing portion 332 is arranged on both sides in the left-right direction of the rough surface portion 29 arranged at the center in the front-rear direction of the three rough surface portions 29.

The smoothing portion 332 has a smoothing surface 332W extending in a direction away from the upper surface of the terminal 40. The smooth surface 332W is formed to be smoother and flatter than the surface of the rough surface portion 29, and has a rectangular shape that is long in the front-rear direction.

Next, the inspection method of the electric wire 10 with a terminal in this embodiment will be described.
A resistance measuring instrument for measuring electrical resistance further includes a second probe P2 and a third probe P3, as shown in FIGS. 16 and 17.

As shown in FIG. 16, the second probe P2 is formed in an arch shape having a concave portion P21 and having a rectangular shape in front view. The recess P21 is formed so as to be recessed upward from the lower end in the central portion in the left-right direction of the second probe P2. The inner surface of the recess P21 in the left-right direction is a smooth and flat examination surface P22 extending in the vertical direction. An insulating portion P23 is formed at the lower end of the second probe P2.

Therefore, when inspecting the terminal-equipped electric wire 310 of the present embodiment, the welded portion 326 is first inserted into the recess P21 of the second probe P2. In the process of inserting the welded portion 326, when the insulating portion P23 of the second probe P2 comes into contact with the terminal 40, the second probe P2 is slid in either the left-right direction as shown in FIG. As a result, the smooth surface 332W of the smooth portion 332 of the high compression portion 327 and the examination surface P22 come into surface contact with each other, and the electrical resistance between the terminal 40 and the welded portion 326 can be measured. That is, since the second probe P2 can be easily aligned with the smoothed portion 332, the electric resistance between the welded portion 326 and the terminal 40 can be easily measured.

On the other hand, the third probe P3 is configured as a sandwich type having a pair of sandwiching portions P31 as shown in FIG. The mating surfaces at the tips of the pair of sandwiching portions P31 are flat and smooth examination surfaces P32. Therefore, when inspecting the electric wire 310 with a terminal by the third probe P3, as shown in FIG. 17, the pair of smoothing portions 332 are sandwiched by the pair of sandwiching portions P31 from both sides in the left-right direction, so that the smooth surface 332W And the examination surface P32 come into surface contact with each other. That is, the operator can easily measure the electrical resistance between the welded portion 326 and the terminal 40 simply by sandwiching the pair of smoothing portions 332 with the pair of sandwiching portions P31 of the third probe P3.

<Other embodiments>
The techniques disclosed herein are not limited to the embodiments described above and in the drawings, and include, for example, various aspects such as:

(1) In the first embodiment, the low compression section 30 having the smoothing section 32 is configured in front of the high compression section 27. However, the present invention is not limited to this, and a low compression portion having a smooth portion may be configured behind the high compression portion.

(2) In the above embodiment, the rough surface portions 29 and 229 are configured to extend in a direction orthogonal to the extending direction of the electric wire 20. However, the present invention is not limited to this, and the rough surface portion may be configured to extend in an oblique direction with respect to the extending direction of the electric wire.

(3) In the above embodiment, the terminal 40 is formed in a rectangular plate shape in a plan view. However, the present invention is not limited to this, and a connecting portion connected to another terminal may be formed at the tip of the terminal, or a connecting portion connected to another member may be formed on the side portion of the terminal.

10: Electric wire with terminal 20: Electric wire 22: Core wire 24: Insulation coating 26: Welded part 27: High compression part 28: Main body part 29: Rough surface part 30: Low compression part 31: Connecting part 32: Smooth part 32U: Smooth surface 40 : Terminal 42: Electric wire connection 44: Adjacent 80: Ultrasonic welding device 81: Anvil 82: Base 85: Position holding part 86: Terminal holding part 88: Electric wire holding part 89: Horn insertion recess 91: Welding horn 92: Recessed portion 92A: Inner wall 93: Welded recess 95: Highly pressurized portion 96: Holding groove 97: Low pressurized portion 98: Pressurized surface 99: Pressurized flat surface 110: Wire with terminal 126: Welded portion 127: Highly compressed portion 128 : Main body 132: Smooth 132U: Smooth surface 210: Electric wire with terminal 220: Electric wire 222: Core wire 226: Welded part 227: High compression part 228: Main body part 229: Rough surface part 232: Smoothing recess (Example of "smoothing part") )
232U: Smooth surface 310: Electric wire with terminal 326: Welded part 327: High compression part 328: Main body part 332: Smooth part 332W: Smooth surface P: Probe P1: Examination surface P2: Second probe P21: Recessed part P22: Examination surface P23 : Insulation part P3: Third probe P31: Holding part P32: Examination surface R: Resistance measuring instrument

Claims (6)

An electric wire with a terminal whose terminal is connected to the end of the electric wire.
The electric wire has a core wire which is a bundle of a plurality of strands.
The terminal has an electric wire connecting portion and an adjacent portion.
The adjacent portion is formed in a flat plate shape so as to be connected to the electric wire connecting portion.
The core wire exposed at the end of the electric wire is connected to the electric wire connecting portion.
The core wire connected to the wire connection portion has an ultrasonically welded welded portion.
The welded portion has at least one rough surface portion and at least one smooth portion.
The rough surface portion has a rough surface and is
The smooth portion is an electric wire with a terminal whose surface is smoother than the rough surface portion and is formed flatter than the rough surface portion. The electric wire with a terminal according to claim 1, wherein the smooth portion is formed at the tip end portion of the welded portion. The rough surface portion is formed in a plurality of directions in the extending direction of the electric wire.
The electric wire with a terminal according to claim 1, wherein the smooth portion is formed between a plurality of the rough surface portions. The electric wire with a terminal according to claim 3, wherein the smooth portion is arranged in pairs on both sides in the width direction of the welded portion. The smooth portion is formed by being recessed toward the electric wire connecting portion.
The electric wire with a terminal according to claim 1 or 3, wherein the surface of the bottom portion of the smooth portion is smoother than the rough surface portion and is formed flatter than the rough surface portion. This is an inspection method for electric wires with terminals whose terminals are connected to the ends of the electric wires.
The electric wire has a core wire which is a bundle of a plurality of strands.
The terminal has an electric wire connecting portion and an adjacent portion.
The adjacent portion is formed in a flat plate shape so as to be connected to the electric wire connecting portion.
The core wire exposed at the end of the electric wire is connected to the electric wire connecting portion.
The core wire connected to the wire connection portion has an ultrasonically welded welded portion.
The welded portion has at least one rough surface portion and at least one smooth portion.
The rough surface portion has a rough surface and is
The smooth portion is smoother than the rough surface portion and is formed flatter than the rough surface portion.
A method for inspecting an electric wire with a terminal for inspecting the joint state between the welded portion and the terminal by bringing a probe into surface contact with the adjacent portion and the smooth portion.

Images