JP2008181695A - Manufacturing method for electric cable with terminal, electric cable with terminal, and terminal crimping device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for an electric cable with a terminal that can obtain stable electrical contact and a fixing force when crimping and connecting a terminal to an electric cable. <P>SOLUTION: A split crimper 30 split into a plurality of parts in the axial direction of an electric cable 10 is depressed to a prescribed height in a state of being integrally overlapped with a terminal pressing-face 32 for pressing a core-wire crimping part 26 of a terminal 20 so as not to form a step in the axial direction. The electric cable 10 and the core-wire connecting part 26 are wholly and uniformly crimped and connected to each other. Subsequently, the split crimper 30 partially stays at the prescribed height. Other parts of the split crimper 30 are further depressed while pressingly fixing the core-wire crimping part 26. Consequently, the core-wire crimping part is locally and further strongly pressed so as to crimp and connect the terminal 20 to the electric cable 10. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method of manufacturing an electric wire with a terminal, an electric wire with a terminal, and a terminal crimping device, and more specifically, when a terminal is crimped and connected to a core wire exposed at an end portion of the electric wire via a crimping piece. The present invention relates to a method for manufacturing a terminal-attached electric wire having both good electrical connection and mechanical fixing force.

  In recent years, electric and electronic devices mounted on automobiles have increased in variety, and high performance and multi-function have been rapidly promoted. Electric wires connected with terminals are connected to these individual devices via connectors, and signal transmission and power supply are performed via these electric wires with terminals. As the performance of equipment increases, it is required to improve the connection reliability of these electric wires and terminals, and it is important to solve the contradiction that the fixing force decreases when the electrical connection reliability is improved.

  In general, when connecting a terminal to such an electric wire, the core wire crimping portion of the terminal provided with a pair of crimping pieces erected facing each other is peeled off the insulating coating material. And crimping the core wire crimping part by pressing it from above and below with a crimper and an anvil. When a terminal is connected to an electric wire by such a crimp connection, an optimum crimp height (C / H) or crimp width (C) is obtained in order to obtain a predetermined fixing force and contact resistance between the terminal and the electric wire. / W) is set.

  As shown in FIG. 10, as the crimp height (C / H) changes, the fixing force and the contact resistance between the terminal and the electric wire change. In order to satisfy the predetermined performance with both the fixing force and the contact resistance, the range I satisfies the range I satisfying the performance required for the fixing force and the overlapping range A satisfying the performance II required for the contact resistance. The crimp height (C / H) must be set.

  On the other hand, there is a demand for improvement in the performance of the bonding force and contact resistance of the crimp connection portion between the terminal and the electric wire, and the ranges I and II satisfying the performance required for each are becoming increasingly narrow. Then, the overlapping range A of the ranges I and II satisfying these required performances is an extremely narrow range, and in the method of caulking the entire core wire crimping portion as described above, the terminals and the so as to satisfy the required performances. Connecting wires is extremely difficult.

  Therefore, as a crimping method for solving such a problem, the crimping portion of the terminal is crimped with a crimper having a stepped shape as described in, for example, Japanese Patent Application Laid-Open No. 59-165390 (Patent Document 1). A method has been proposed. FIG. 11 shows a state in which the terminal 120 is crimped to the electric wire 130 by the crimping method described in Patent Document 1. The front end direction of the electric wire 130 placed on the terminal 120 will be described as the front, and the base side of the electric wire 130 will be described as the rear.

  The crimper 110 described in this patent document 1 has a front side 112 that is a portion for caulking the terminal 120 strongly and a rear side 114 that is a portion for caulking weakly. By crimping the core wire crimping portion 122 of the terminal 120 using such a crimper 110, the front side 122a of the core wire crimping portion 122 has a lower crimp height (C / H), and the rear side 122b has a crimp height ( C / H) increases. Therefore, an optimum crimp height (C / H) is set on the front side 122a to ensure electrical performance such as contact resistance, and a machine such as a fixing force of the terminal 120 to the electric wire 130 is set on the rear side 122b. The crimp height (C / H) optimum for the mechanical strength can be set and the terminal 120 can be crimped and connected to the electric wire 130.

  However, when caulking the core wire crimping part 122 using such a stepped crimper 110, first, only the front side 112 of the most protruding crimper starts to press the front side 122a of the core wire crimping part 122. Then, the core wire 132 crimped by the front side 122a of the core wire crimping part 122 is crushed, and the strand of the core wire 132 is pushed out in the axial direction of the electric wire and extends. Subsequently, the rear end side 114 of the crimper presses and crimps the rear side 122b of the core wire crimping part 122.

  When the crimper 110 rises and the core wire crimping portion 122 is released, a so-called springback phenomenon occurs in which the core wire crimping portion 122 tends to return to the shape before the crimping, although it is slightly elastic. Here, if the deformation of the strand of the core wire 132 when the crimper 110 presses the core wire 132 through the core wire crimping portion 122 is small, the force that the core wire crimping portion 122 springs back and clamps the core wire 132. As the wire becomes weaker, the deformation of the wire can be recovered to follow up to some extent.

  FIG. 11B and FIG. 11C show radial cross sections of the front side 122 a and the rear side 122 b of the core wire crimping part 122. On the rear side 122b with a high crimp height (C / H), the strands of the core wire 132 are not so thin, and a large gap does not occur in the core wire crimping portion rear side 122b. However, as shown in FIG. 11 (b), since the crimp height (C / H) is low and the core wire is strongly pressed on the front side 122a of the core wire crimping portion 122, the strands constituting the core wire 132 itself Is getting thinner. For this reason, gaps are generated between the core wire and the terminal and between the core wires. As a result, the electrical connection deteriorates and the predetermined electrical performance cannot be satisfied. In addition, when the core wire becomes thin in this way, not only the contact resistance increases, but also the mechanical strength of the core wire becomes weak and the core wire easily breaks.

JP 59-165390 A

  Therefore, the problem to be solved by the present invention is that when the terminal is crimped and connected to the electric wire, the terminal and the electric wire have good electrical connection and mechanical fixing force, and the extension of the core wire crimped by the crimping piece of the terminal An object of the present invention is to provide a method of manufacturing a terminal-attached electric wire, a terminal-attached electric wire, and a terminal crimping apparatus capable of suppressing thinning and obtaining stable electrical contact and adhesion.

  In order to solve the above-described problems, the method for manufacturing a terminal-attached electric wire according to the present invention is such that a conductive terminal is connected to an electric wire terminal in which a core wire made of a conductive wire is covered with an insulating covering material. When manufacturing an electric wire with a terminal, the electric wire is connected to a core wire crimping portion provided with a crimping piece erected on both sides of a base portion extending from one end of a connection portion connected to a mating terminal of the terminal. The exposed core wire is placed, this core wire crimping portion is received by the terminal receiving surface provided on the anvil, and the shaft of the electric wire placed facing the anvil and placed on the core wire crimping portion of the terminal The divided crimper divided into a plurality of directions is pushed down to a predetermined height in a state where the terminal crimping surface presses the core wire crimping portion of the terminal so that there is no step in the axial direction of the electric wire. Terminal pressing surface and end of the anvil The core wire connection portion is clamped between the receiving surface and the electric wire and the core wire connection portion are crimped and connected uniformly evenly. Subsequently, the divided crimper is partially at the predetermined height. The other portion of the split crimper is further pushed down from the predetermined height, and the core wire crimping portion is pressed more strongly locally, and the core wire crimping portion is pressed radially. The gist of the invention is that the terminal is crimped and connected to the core wire in a state where a portion pressed strongly from the whole and a portion pressed weakly are mixed in the axial direction.

  Further, when some of the plurality of divided crimpers are further pushed down from the predetermined height, the divided crimpers located on the base side of the electric wire of the core wire crimping portion remain at the predetermined height and the core wire crimping portion. It is preferable that the terminal is strongly pressed and connected to the core wire by further pressing down the split crimper at the electric wire terminal side or at the intermediate portion.

  In addition, the terminal is connected to the core wire by the split crimper in which the corner portion formed by the end surface on the base side of the electric wire and the terminal pressing surface of the crimper of the portion that is pushed down from the predetermined height of the plurality of split crimpers is chamfered. It is more preferable to make a strong crimp connection.

  Further, in a portion where a part of the plurality of divided crimpers presses the core wire connecting portion more strongly, the height of the crimping piece erected opposite to both sides of the base portion of the core wire crimping portion is If the terminal made lower than the height on the base side of the electric wire is used, it is suitable for the method for manufacturing an electric wire with a terminal according to the present invention.

  In addition, in order to manufacture an electric wire with a terminal by the manufacturing method according to the present invention, a terminal crimping apparatus that presses a terminal on which the electric wire is placed with a crimper and an anvil and crimps and connects the terminal to the core wire. And an anvil provided with a receiving surface for receiving the terminal, and a crimper disposed opposite to the receiving surface of the anvil, the crimper being divided into a plurality in the axial direction of the electric wire to be crimped and connected to the terminal. A terminal crimping device is preferably used in which each of the divided crimpers can be separated and approached independently from the anvil.

  According to the method for manufacturing an electric wire with a terminal according to the present invention, when the core wire of the electric wire is clamped by the core wire crimping portion of the terminal, first, the divided crimper is integrated so that there is no step in the axial direction of the electric wire. Since the core wire crimping portion is crimped by being pushed down to a predetermined height in an overlapping state, the core wire sandwiched between the core wire crimping portions is tightened and fixed as a whole with an equal force.

  Subsequently, in a state where the movement of the core wire in the core wire crimping portion is regulated in this way, the divided crimper is further pushed down locally from the predetermined height, and the core wire connecting portion is pressed more strongly. As a result, the core wire crimping portion caulks the core wire more strongly in the portion pressed more strongly locally. At this time, the other part of the split crimper is kept pressed down to the predetermined height, and the core wire crimping part is kept pressed and fixed.

  Accordingly, the core wire is fixed at at least one end of the locally strongly pressed portion of the core wire crimping portion, so that the core wire can be prevented from extending and escaping even if the core wire is strongly caulked. . Since the core wire is strongly caulked by the core wire crimping portion in such a state that the escape or thinning of the core wire is suppressed, the core wire can be filled with no gap in the core wire crimping portion.

  Thereby, the contact between the core wire, the core wire crimping portion, and the strands constituting the core wire is improved, and very good electrical contact can be obtained.

  On the other hand, the core crimping portion in the portion that maintains the state where the divided crimper is pressed down to the predetermined height has a good fixing force between the terminal and the core wire, and the portion that is strongly pressed locally Can be protected.

  In addition, when the divided crimper further presses the core wire connecting portion more strongly, a portion that maintains the state of being pressed down to the predetermined height is disposed on the base side of the electric wire held between the core wire crimping portions. Then, the portion where the core wire crimping portion is locally strongly pressed may be arranged at a position other than the distal end side of the electric wire or the base side end portion of the core wire crimping portion. In this way, even if an excessive force is applied to the electric wire by, for example, the electric wire being pulled or bent, the portion where such a force is most easily applied in the crimp connection portion between the terminal and the core wire, That is, a weakly crimped portion having a good fixing force is arranged on the electric wire base side of the core wire crimping portion. Therefore, since it is difficult for force to be transmitted to a strongly pressed portion having good electrical contact, it is possible to achieve both wire adhering force and electrical connection reliability.

  Furthermore, if the corner part which consists of the contact surface of each crimper which comprises the said division | segmentation crimper, and the terminal press surface which presses a terminal is chamfered and the taper part is formed, the said core wire crimping part of a terminal will be pressed strongly. The boundary between the part to be pressed and the weakly pressed part becomes smooth. Accordingly, the core wire crimping portion cannot withstand large deformation at the boundary between the strongly pressed portion and the weakly pressed portion of the core wire crimping portion, and problems such as cracks are unlikely to occur.

  In the portion where the divided crimper locally presses the core wire connecting portion more strongly, if a terminal formed with a low crimping piece standing facing both sides of the base portion of the core wire crimping portion is used More preferable. The height of the crimping piece before the crimping process corresponds to the circumferential length of the core wire after the crimping process, and is a portion that further presses the core wire connecting portion, and the crimping piece is a base portion of the core wire crimping part. It is possible to prevent the occurrence of crimping failure due to the above.

  Thus, according to the terminal crimping apparatus provided with at least two or more independently splittable crimpers that are split in the axial direction of the electric wire placed on the terminal, the core wire crimping portion is good for the core wire. Crimping connection can be performed in a state of having both an electrical connection and a mechanical fixing force.

  Hereinafter, a first embodiment of the present invention will be described in detail with reference to FIGS. In addition, let the front end side of the electric wire mounted on this terminal be the front, and let the base side of this electric wire be the back. FIG. 1 is a perspective view showing a state before the terminal 20 is crimped and connected to the end of the electric wire 10, and FIG. 2 is a cross-sectional view showing a process of crimping and connecting the terminal 20 to the electric wire 10 shown in FIG. It is a thing. FIG. 3 is a perspective view of the electric wire 10 shown in FIG.

  As shown in FIG. 1, the electric wire 10 is formed by covering a core wire 12 formed by twisting a plurality of metal wires with a covering material 14 made of an insulating synthetic resin. The core wire 12 is exposed by skinning for a predetermined length.

  The terminal (in this case, female type) 20 is formed by bending a metal plate-like member, and includes a connecting portion 22, a base portion 24, and a core wire crimping portion 26 including crimping pieces 26a and 26b. And a covering crimping portion 28 composed of the crimping pieces 28a and 28b.

  The connecting portion 22 is formed in a substantially rectangular tube shape, and an elastic contact piece 22a is provided therein, and a distal end portion of a mating terminal (in this case, a male type) (not shown) is inserted. Electrically conducted. The base portion 24 is extended from the rear end portion of the connection portion 22, and a pair of core wire crimping pieces 26 a for caulking and fixing the core wire 12 of the electric wire 10 on the left and right sides of the intermediate portion of the base portion 24, 26 b is erected upward and constitutes the core wire crimping portion 26. In addition, a pair of covering crimping pieces 28a and 28b for caulking and fixing the covering 14 of the electric wire 10 are erected upward on the left and right sides of the rear end portion of the base portion 24, and the covering crimping section 28. Is configured.

  The core wire crimping pieces 26a and 26b provided in the core wire crimping portion 26 may be provided in at least one pair, and the number of pairs is not particularly limited. Moreover, although the terminal which has the crimping | compression-bonding pieces 28a and 28b for coating | cover was illustrated in the figure, the terminal of the type without the coating crimping | compression-bonding part 28 can also be used. Moreover, although the female-type thing was illustrated as a shape of the connection part 22, of course, a male-type shape may be sufficient.

  The core wire side crimper 30 and the core wire side anvil 40 and the covering side crimper 50 and the covering side anvil 60 are crimped by sandwiching the core wire crimping pieces 26a and 26b and the covering crimping pieces 28a and 28b of the terminal 20 by a press operation of a terminal crimping device (not shown). A crimping jig for connecting the terminal 20 to the core wire 12 exposed at the terminal portion of the electric wire 10.

  The core wire side crimper 30 includes a rear crimper 30a and a front crimper 30b which are divided into two in the axial direction of the electric wire 10 placed on the core wire crimping portion 26 of the terminal 20, and the rear crimper 30a and the front crimper 30b. Can be moved up and down independently.

  The core wire side crimper 30 is for pressing the crimping pieces 26a, 26b of the core wire crimping portion 26 of the terminal 20 from above, and a terminal pressing surface 32 is formed on the lower end surface thereof. The terminal pressing surface 32 is formed with guiding portions 34a and 34b having arch-shaped curved surfaces on its side surfaces, and a protruding portion 36 is formed in the vicinity of the center where both the arches 34a and 34b are connected. The arch-shaped guide portions 34a and 34b guide the tips of the crimping pieces 26a and 26b for the core wire of the terminal 20 inward when the terminal 20 is sandwiched between the core wire-side crimper 30 and the core wire-side anvil 40. The protruding portion 36 is formed so as to wind the tip ends of the core wire crimping pieces 26a and 26b in the direction of the core wire 12.

  On the other hand, the core wire side anvil 40 is for supporting the terminal 20 from below, and a terminal receiving surface 42 is formed on the upper end surface thereof according to the curvature after caulking of the base portion 24 of the core wire crimping portion 26. Yes.

  In addition, the covering side crimper 50 and the covering side anvil 60 are pressed and clamped by sandwiching the covering crimping portion 28 of the terminal 20 disposed between them, and connecting the terminal 20 to the terminal portion of the electric wire 10. The core wire side crimper 30 and the core wire side anvil 40 are formed slightly larger than the core wire 12 in accordance with the diameter of the coating 14 that is thicker than the core wire 12, and generally have the same configuration.

  That is, when the coated crimping portion 28 of the terminal 20 is sandwiched between the lower end surface of the coated crimper 50 and the coated anvil 60, the tips of the coated crimping pieces 28a and 28b are guided and pressed inward. A terminal pressing surface 52 is formed, and a terminal receiving surface 62 is formed on the upper end surface of the covering-side anvil 60 according to the curvature of the base portion 24 of the covering crimping portion 28 after being crimped.

  Next, the process of crimping and connecting the terminal 20 to the electric wire 10 will be described in order with reference to FIGS. FIG. 2A shows an AA cross section of the electric wire 10 and the terminal 20 shown in FIG. The electric wire 10 is placed on the base portion 24 of the terminal 20 so that the exposed core wire 12 is on the core wire crimping portion 26 of the terminal 20 and the covering material 14 is on the covering crimping portion 28. The core wire side crimper 30 and the anvil 40, and the covering side crimper 50 and the anvil 60 are arranged at positions facing each other with 20 therebetween. Here, the rear crimper 30a and the front crimper 30b constituting the core wire side crimper 30 are integrally overlapped on the terminal pressing surface 32 so that no step is generated in the axial direction of the electric wire 10.

  Subsequently, as shown in FIG. 2B, the core side crimper 30 is lowered while the rear crimper 30a and the front crimper 30b are integrally overlapped with each other, and the core wire of the terminal 20 is interposed between the core wire side anvil 40 and the core wire side anvil 40. The crimping part 26 is inserted. The core wire crimping pieces 26a and 26b are guided to guide portions 34a and 34b having an arch-shaped curved surface of the crimping die 32 provided on the lower surface of the core wire side crimper 30 (see FIG. 1) so as to uniformly wrap the core wire 12. Go.

  Here, the core side crimper 30 is lowered to a predetermined height in a state where the rear crimper 30a and the front crimper 30b are integrally overlapped. At this time, the core wire crimping portion 26 is pressed to an optimum crimp height (C / H) for mechanically fixing the core wire 12 and the terminal 20.

  Subsequently, as shown in FIG. 2 (c), the front crimper 30 b of the core wire side crimper 30 continues to descend further and presses the front portion of the core wire crimping portion 26 more strongly. Thereby, the part pressed by the front crimper 30b of the core wire crimping part 26 caulks the core wire 12 more strongly.

  Here, when the core wire crimping portion 26 is strongly pressed by the front crimper 30b, the core wire 12 is strongly caulked and crushed. Normally, when the core wire is crushed strongly in this way, the core wire extends back and forth and becomes thin. However, even if the front crimper 30b strongly presses the front portion of the core crimping portion 26, the rear portion is fixed and pressed by the rear crimper 30a, so the core wire 12 does not extend backward. Therefore, it is possible to prevent the core wire 12 from becoming thin.

  In this way, the terminal 20 is connected to the electric wire 10 in a state where the portion 26l having a low crimp height (C / H) and the portion 26h having a high crimp height (C / H) are mixed in the core crimping portion 26. (Fig. 2 (d)).

  FIG. 3 is a perspective view of a state in which the terminal 20 is crimped and connected to the electric wire 10. A portion 26l having a low crimp height (C / H) is provided in front of the core wire crimping portion 26, and a portion 26h having a high crimp height (C / H) is provided behind the portion 26l. Further on the rear side, a coating crimping portion 28 is provided, and the crimping connection is uniformly made as a whole. With such a configuration, when the base side of the electric wire 10 is pulled or bent, the force is applied to the portion 26 l with a low crimp height (C / H) in front of the core wire crimping portion 26. It is difficult to transmit, and it is possible to achieve both wire adhering strength and electrical connection reliability.

  4 is an arrow view showing a radial cross-section in a state where the terminal 20 is connected to the tip of the electric wire 10 shown in FIG. 3, and FIG. 4 (a) is a crimp height (C / H). The EE cross section of the low part 26l is shown. FIG. 4B shows an FF cross section of a portion 26 h having a high crimp height (C / H).

  As shown in FIG. 4A, the core wire 12 is crimped by pressing the core wire crimping portion 26 by the front crimper 30 b and is compressed in the radial direction of the core wire 12. However, in the state where the rear crimper 30a presses the high crimp height (C / H) portion 26h of the core crimping portion 26, the front crimper 30b further presses the low crimp height (C / H) portion 26l. Therefore, the core wire 12 does not run backward and escape. Therefore, as shown in FIG. 4A, there is no thinning of the strands, and no gap is generated between the core wire 12 and the core wire crimping portion 26 of the terminal 20 and between the strands of the core wire 12.

  On the other hand, as shown in FIG. 4 (b), the portion 26h having a high crimp height (C / H) is pressed by the rear crimper 30a so that the load applied to the core wire 12 is reduced to the crimp height (C / H). ) Is smaller than the lower portion 26l, and the deformation of the core wire 12 is small. Therefore, even if the rear crimper 30a stops pressing and the core wire crimping portion 26 is released and springs back, the core wire 12 can follow the shape and recover its shape. Therefore, a large gap does not occur in the core wire crimping portion 26 even in the portion 26h having a high crimp height (C / H).

  Thus, since a clearance is not easily generated in the core wire crimping portion 26, the electrical connection between the core wire 12 and the terminal 20 is stable, and the contact resistance does not increase. Moreover, since the core wire 12 and its strand are not thinned, the strength of the core wire 12 itself can be prevented from being reduced, and the strand of the core wire 12 is cut by pulling or bending the electric wire 10. It becomes difficult for trouble to occur. Further, by setting different crimp height (C / H) and crimp width (C / W) between the high portion 26h and the low portion 26l of the crimp height (C / H) of the core wire crimping portion 26, the electric wire It is easy to manage the fixing force, contact resistance, etc., can suppress variations in product performance, and can reliably obtain a predetermined crimped state.

  Next, a second embodiment of the present invention will be described with reference to FIG. 5 (a) to 5 (f) show the connection process of the terminal to the electric wire 10 according to the second embodiment of the present invention in a sectional arrow view.

  As shown in FIG. 5A, the electric wire 10 and the terminal 20 a have the same configuration as that of the first embodiment shown in FIGS. 1 to 3, and the electric wire with the core wire 12 exposed by peeling off the tip. 10 is placed on the core crimping portion 26 and the covering crimping portion 28 of the terminal 20a. The core side crimper 30 and the anvil 40, and the covering side crimper 50 and the anvil 60 are arranged to face each other with the terminal 20a interposed therebetween.

  In the second embodiment, the core wire side crimper 30 is disposed above the core wire crimping portion 26 of the terminal 20 such that the rear crimper 30a, the front crimper 30b, and the tip crimper 30c are integrally overlapped. Each of the rear crimper 30a, the front crimper 30b, and the tip crimper 30c can move up and down independently.

  As shown in FIG. 5B, the core side crimper 30 is integrated so that the rear crimper 30a, the front crimper 30b, and the tip crimper 30c are not stepped in the axial direction of the electric wire 10 on the terminal pressing surface 32. It descends in a state where it overlaps with. When the core wire crimping portion 26 of the terminal 20a is sandwiched between the core wire side crimper 30 and the core wire side anvil 40, the core wire crimping pieces 26a and 26b wrap around the core wire 12. Thus, the core wire side crimper 30 continues to descend to a predetermined height, the core wire side anvil 40 supports the core wire crimping portion 26 from below, and the core wire 12 is sandwiched between the core wire crimping pieces 26a and 26b of the core wire crimping portion 26. Caulking.

  Subsequently, as shown in FIG. 5 (c), the front crimper 30 b located in the intermediate layer of the core wire side crimper 30 continues to descend further and presses the intermediate portion of the core wire crimping portion 26 more strongly. Thereby, the part pressed by the front crimper 30b of the core wire crimping part 26 caulks the core wire 12 more strongly.

  Here, when the core wire crimping portion 26 is strongly pressed by the front crimper 30 b, the core wire 12 is strongly crushed at an intermediate portion of the core wire crimping portion 26. Normally, when the core wire is crushed strongly in this way, the core wire extends back and forth and becomes thin. However, even if the front portion of the core crimping portion 26 is strongly pressed by the front crimper 30b, the rear portion is fixed and pressed by the rear crimper 30a, and the front portion is fixed and pressed by the tip crimper 30c. Accordingly, the core wire 12 cannot extend backward or forward. Therefore, it can prevent very effectively that the strand of the core wire 12 becomes thin.

  When the terminal 20 is crimped and connected to the core wire 12 in this way, as shown in FIG. 5D, a portion 26h having a high crimp height (C / H) is provided in front of the core wire crimping portion 26, and thereafter A portion 26l with a low crimp height (C / H) is provided on the side, and a portion 26h with a high crimp height (C / H) is provided further on the rear side. In this way, if the portion 26l having a low crimp height (C / H) is disposed between the portions 26h having a high crimp height (C / H), the crimp height (C / H) is low. It is possible to effectively prevent the core wire 12 from extending from the portion 26l and the wire constituting the core wire 12 from becoming thin.

  Further, a portion 26h having a high crimp height (C / H) is provided behind the portion 26l having a low crimp height (C / H), and a covering crimping portion 28 is provided further to the rear thereof. . Therefore, when the base portion of the electric wire 10 is pulled or bent, the force is difficult to be transmitted to the portion 26l having a low crimp height (C / H) in front of the core wire crimping portion 26, and the wire fixing force Both electrical connection reliability can be achieved.

  FIG. 5E shows an EE cross section of a portion 26 l having a low crimp height (C / H). FIG. 5F shows an FF cross section of a portion 26h having a high crimp height (C / H). As shown in FIG. 5 (d), the core wire 12 is crimped by pressing the core wire crimping portion 26 by the front crimper 30 b, and is compressed in the radial direction of the core wire 12. However, in a state where the movement of the core wire 12 in the core wire crimping portion 26 is restricted by the rear crimper 30a and the tip crimper 30c, the front crimper 30b further presses and crimps the portion 26l having a low crimp height (C / H). Since it is processed, the core wire 12 does not extend backward and forward and escape. Accordingly, as shown in FIG. 5 (e), there is no thinning of the strands, and no gap is formed between the core wire 12 and the core wire crimping portion 26 of the terminal 20 and between the strands of the core wire 12. Thus, if the terminal 20 is crimped and connected to the core wire 12, an electric wire with a terminal having both a high fixing force and a low contact resistance can be manufactured.

  Furthermore, a third embodiment of the present invention will be described with reference to FIG.

  As shown in FIG. 6A, the electric wire 10 and the terminal 20 have the same configuration as that of the first embodiment shown in FIG. 1, and the electric wire 10 with the core wire 12 exposed by peeling off the tip is a terminal. 20 core wire crimping portions 26 and covering crimping portions 28 are mounted. The core side crimper 30 and the anvil 40, and the covering side crimper 50 and the anvil 60 are arranged to face each other with the terminal 20 interposed therebetween.

  The rear corner portion of the terminal pressing surface 32 of the front crimper 30b is chamfered to form a tapered portion 30t. The core side crimper 30 is disposed above the core wire crimping portion 26 of the terminal 20 so that the rear crimper 30a and the front crimper 30b are integrally overlapped with each other. Each of the rear crimper 30a and the front crimper 30b can move up and down independently.

  And the core side crimper 30 descend | falls in the state which the back crimper 30a and the front crimper 30b overlapped integrally so that there may be no level | step difference in the axial direction of the electric wire 10 in the terminal press surface 32. When the core wire crimping portion 26 of the terminal 20a is sandwiched between the core wire side crimper 30 and the core wire side anvil 40, the core wire crimping pieces 26a and 26b wrap around the core wire 12. Thus, the core wire side crimper 30 continues to descend to a predetermined height, the core wire side anvil 40 supports the core wire crimping portion 26 from below, and the core wire 12 is sandwiched between the core wire crimping pieces 26a and 26b of the core wire crimping portion 26. Then squeak.

  Subsequently, as shown in FIG. 6B, the front crimper 30 b of the core wire side crimper 30 continues to descend further and presses the front portion of the core wire crimping portion 26 more strongly. Thereby, the part pressed by the front crimper 30b of the core wire crimping part 26 caulks the core wire 12 more strongly. Here, since the taper part 30t is formed in the corner | angular part of the terminal press surface 32 of the front crimper 30b, the part pressed by the front crimper 30b of the core wire crimping part 26, and the part pressed by the back crimper 30a The level difference at the boundary is smoothly embossed.

  In this way, the terminal 20 is connected to the electric wire 10 in a state where the portion 26l having a low crimp height (C / H) and the portion 26h having a high crimp height (C / H) are mixed in the core crimping portion 26. It can be crimped to.

  As shown in FIG. 6 (c), the front crimper 30b is located at the boundary between the portion 26l having a low crimp height (C / H) and the portion 26h having a high crimp height (C / H). An inclined portion 26t that is smoothly inclined by pressing by the taper portion 30t is formed. By doing in this way, the crimping pieces 26a and 26b of the core wire crimping portion 26 are crushed at the boundary between the portion 26l having a low crimp height (C / H) and the portion 26h having a high crimp height (C / H), Problems such as a decrease in thickness and a decrease in mechanical strength, or cracks are unlikely to occur.

  Subsequently, a fourth embodiment of the present invention will be described with reference to FIG. FIGS. 7A and 7B show the connection process of the terminal to the electric wire 10 according to the fourth embodiment of the present invention in a cross-sectional arrow view.

  As shown in FIG. 7A, the electric wire 10 and the terminal 20b have substantially the same configuration as that of the first embodiment shown in FIG. 1, and the electric wire 10 with the core wire 12 exposed by peeling off the tip is shown. It is mounted on the core wire crimping part 26 and the covering crimping part 28 of the terminal 20b. The core side crimper 30 and the anvil 40, and the covering side crimper 50 and the anvil 60 are arranged to face each other with the terminal 20b interposed therebetween.

  From the rear end of the connection part 22 of this terminal 20b, the base part 24 in which the terminal of the electric wire 10 is mounted is extended, and the core wire 12 of the electric wire 10 is provided on the left and right sides of the intermediate part of the base part 24. A pair of crimping pieces for core wire 26a, 26b for caulking and fixing is erected upward. A cutout 26s is provided at the front upper end portion of the core wire crimping pieces 26a, 26b, and the lengths of the core wire crimping pieces 26a, 26b are short.

  The core wire side crimper 30 and the anvil 40, and the covering side crimper 50 and the anvil 60 are the same as those in the first embodiment, and the crimping process also includes a portion 26l having a low crimp height (C / H). The same is true in that a portion 26 h having a high crimp height (C / H) is disposed at the rear portion of the core wire crimping portion 26 and is disposed at the front portion of the portion 26.

  In FIG. 7B, the core wire crimping portion 26 and the covering crimping portion 28 of the terminal 20 are pressed against the core wire side crimper 30 and the anvil 40, and the coating side crimper 50 and the anvil 60 to be crimped and connected to the electric wire 10. It is sectional drawing of a state. As in FIG. 2D, the front side of the core wire crimping portion 26 is crimped one step lower by the front crimper 30 b of the core wire crimper 30.

  FIG. 7C and FIG. 7D are cross-sectional views in the radial direction of a portion 261 having a low crimp height (C / H) and a portion having a high crimp height (C / H) 26 h of the core wire crimping portion 26. is there. According to this terminal 20b, a notch 26s is provided in the front part of the core wire crimping pieces 26a, 26b, and the core wire crimping piece 26a, 26b has a lower crimp height (C / H) portion 26l. The length of 26a, 26b is formed short. Therefore, for example, as can be seen from comparison with FIG. 4A and the like, after crimping, the tips of the core wire crimping pieces 26a and 26b are pressed by the protruding portion 36 provided at the center of the terminal pressing surface 32 of the crimper 30b. However, the tip ends of the core wire crimping pieces 26 a and 26 b do not come too close to the base portion 24.

  The terminal-attached electric wire (Example 1) in which the terminal is crimped by the method for manufacturing the electric wire with terminal shown in FIGS. 1 to 4 described in the first embodiment, and the terminal using the other method. Are compared with the terminal-attached electric wires (comparative examples 1 and 2) which are crimped to the core wire.

In Example 1 and Comparative Examples 1 and 2, the terminals were crimped to the electric wires by different crimping methods, and the contact resistance and fixing force were measured. In Example 1 and Comparative Examples 1 and 2, the same wires and terminals were applied. Specifically, a copper wire having a core wire cross-sectional area of about 0.5 mm ² was used as the electric wire, and a terminal formed from a copper alloy was applied.

  In Example 1, as shown in FIG. 1 to FIG. 4, first, the entire core wire crimping portion is uniformly caulked so that the entire core wire crimping portion becomes the height of the high crimp height (C / H), and then A position corresponding to a portion having a low crimp height (C / H) was further crimped, and a terminal was crimped and connected to the electric wire.

  In Comparative Example 1, a crimper is formed in a staircase shape in advance as in the electric wire with terminal of Patent Document 1 (Japanese Patent Laid-Open No. 59-165390) shown in FIG. 11, and the crimp height (C / H) is The high part and the low part are caulked simultaneously.

  In Comparative Example 2, the terminal was crimped and connected to the electric wire by a method in which the entire core wire crimping part that was conventionally used was crimped to a uniform crimp height (C / H). The crimp width (C / W) of Example 1, Comparative Example 1 and Comparative Example 2 is the same, and the crimp height (C / H) of Example 1 and Comparative Example 1 is the crimp height (C / H). The higher part of the crimping height is the same as the crimp height (C / H) of Comparative Example 2, and the lower part of the crimping height (C / H) of Example 1 and Comparative Example 1 is the same as each other. The shape was further pushed in from the high portion of H).

  The contact resistance between the core wire of the electric wire and the core wire crimping portion of the terminal crimped and connected to one end of the electric wire is measured by measuring the resistance from the other end of the electric wire to the terminal by the four-terminal method. The resistance value was subtracted.

  The graph shown in FIG. 8 compares the contact resistance between the terminal and the core wire in the core wire crimping portion of the electric wire with terminal of Example 1 and Comparative Examples 1 and 2. In each of the electric wires with terminals of Example 1 and Comparative Examples 1 and 2, the contact resistance in the initial state immediately after the terminals were crimped to the electric wires was measured, and then the electric wires with terminals were placed in an atmosphere of 100 ° C. for 120 hours to be durable. The test was conducted and the contact resistance was measured again. The contact resistance in the initial state is approximately the same as that of Comparative Example 1 with an average of 0.3 mΩ (maximum 0.4 mΩ, minimum of 0.2 mΩ) and Comparative Example 2 with an average of 0.3 mΩ (maximum of 0.5 mΩ, minimum of 0.2 mΩ). On the other hand, Example 1 shows a low value of 0.2 mΩ on average (maximum 0.2 mΩ, minimum 0.2 mΩ). In addition, the contact resistance after the endurance test is 0.9 mΩ (maximum 1.2 mΩ, minimum 0.6 mΩ) in Comparative Example 1 and 0.5 mΩ (maximum 1.4 mΩ, minimum 0.3 mΩ) in Comparative Example 2. In contrast to the respective initial states, the value rises remarkably, but in Example 1, the average value remains 0.2 mΩ (maximum 0.3 mΩ, minimum 0.2 mΩ) and remains low. Further, in Comparative Examples 1 and 2, the variation in contact resistance is large after the durability test, whereas in Example 1, the variation in contact resistance is smaller than that in Comparative Examples 1 and 2 even in the initial state. The variation remains small.

  From this, when comparing the contact resistance, the crimping height (C / H) of the core wire crimping portion is determined by using a crimper in which the terminal pressing surface is previously formed stepwise in the axial direction of the electric wire as in Patent Document 1. The electric wire with a terminal of Comparative Example 1 manufactured by caulking the high part and the low part at the same time is a general electric wire with a terminal in which the entire crimped portion of the core wire is crimped to a uniform crimp height (C / H) (Comparative Example 2) It turns out that there is no big difference. On the other hand, first of all, the core wire crimping portion was caulked to a uniform crimp height (C / H), and then the portion having a lower crimp height (C / H) was further caulked. In the initial state, the electric wire with terminal not only has a low contact resistance, but also its variation is small, and it can be seen that the connection state between the core wire and the core wire crimping portion of the terminal connected to the core wire is very good. Moreover, since the electric wire with a terminal of Example 1 keeps the low contact resistance and the dispersion | variation after an endurance test, it turns out that the connection state is stable. Thus, it turns out that the electric wire with a terminal of Example 1 has the electrical connection superior to any of the comparative examples 1 and 2.

  Thus, as in Comparative Example 1, when the crimped portion (C / H) having a high crimp height (C / H) is caulked at the same time, the core wire escapes at a portion with a low crimp height (C / H). It is considered that thinning occurs and a gap is formed between the core wire crimping portion and the core wire and between the strands constituting the core wire, and good electrical contact is not obtained. On the other hand, in the electric wire with a terminal of Example 1, first, the entire core wire crimping portion is crimped to a uniform crimp height (C / H), and then the portion having a lower crimp height (C / H) is further increased. By being manufactured, the escape of the core wire is suppressed in the portion where the crimp height (C / H) is high, and the escape or thinning of the core wire does not occur in the portion where the crimp height (C / H) is low, It is considered that good electrical contact can be obtained without forming a gap between the core wire, the core wire crimping portion, and the strands constituting the core wire.

  The graph shown in FIG. 9 shows the fixing force of the core wire crimping portion of the electric wires with terminals of Example 1 and Comparative Examples 1 and 2. The fixing force is the tension when the terminal ends of the electric wires with terminals of Example 1 and Comparative Examples 1 and 2 are fixed and the ends of the electric wires are pulled, and the electric wires are detached from the terminals, or when the electric wires are broken. This is the value obtained by measuring the force. The electric wires with terminals of Example 1 average 128N (maximum 136N, minimum 124N), the electric wires with terminals of Comparative Example 1 average 126N (maximum 128N, minimum 121N), and the electric wires with terminals of Comparative Example 2 average 131N (maximum 135N, 126N). The fixing force of the electric wire with terminal of Example 1 is slightly inferior to that of Comparative Example 2, but is higher than that of Comparative Example 1.

  From these facts, the electric wire with terminal of Example 1 has particularly excellent electrical characteristics (contact resistance) as compared with Comparative Examples 1 and 2, and has mechanical characteristics (adhesion force) comparable to those of Comparative Examples 1 and 2. You can see that Thus, the terminal-attached electric wire of Example 1 was obtained by first caulking the entire core wire crimping portion uniformly to suppress the escape of the core wire, and then further caulking the core wire crimping portion locally. By forming the high (C / H) portion and the low portion, the contact between the core wire, the core wire crimping portion, and the strands constituting the core wire is improved, and very good electrical contact and good solidity are achieved. It can be seen that it has an adhesion.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention. For example, in the first to fourth embodiments, an example of a terminal having a core crimping portion and a covering crimping portion has been described, but it goes without saying that a terminal without a covering crimping portion may be used. In 1st-4th embodiment, although it showed by the example of the division | segmentation crimper comprised from 2 or 3 crimpers as a core wire crimper, you may make it comprise from 3 or more crimpers.

  Moreover, although the example which provides a part with low crimp height (C / H) in the front part and intermediate part of a core wire crimping part was shown, you may arrange | position in any site | parts other than the back end part of a core wire crimping part. A plurality of them may be arranged. Further, the crimp height (C / H) is not limited to two stages of high and low, and may be three stages of high, medium and low, for example.

  Moreover, in the said 1st-4th embodiment, although the example which crimps | bonds one electric wire which covered the core wire with the insulating coating | cover to the terminal was shown, this invention is especially limited to such an electric wire. It is not a thing. For example, the present invention is also effective when a plurality of electric wires are crimped to one terminal, or when a terminal is crimped to a shielded electric wire in which an insulating inner covering covering a core wire is further covered with a shield conductor. Needless to say.

  The electric wire with a terminal according to the present invention can obtain a good crimped state between the core wire and the terminal, has a stable contact resistance, and has a high reliability of electrical connection. It can utilize suitably for the connector member of an apparatus, its manufacture, etc.

The state before the connection of the electric wire with a terminal concerning the 1st embodiment of the present invention is shown. 2A to 2D are cross-sectional arrow views showing a connection process of the terminal-attached electric wire shown in FIG. The state after the connection of the electric wire with a terminal shown in FIG. 1 is shown. 4A and 4B are cross-sectional views in the radial direction of the core wire crimping portion of the electric wire with terminal shown in FIG. FIGS. 5A to 5F are cross-sectional arrow views showing a connection process of the electric wire with terminal according to the second embodiment of the present invention. FIGS. 6A to 6C are cross-sectional arrow views showing a connection process of the electric wire with terminal according to the third embodiment of the present invention. FIGS. 7A to 7D are cross-sectional views showing the connection process of the electric wire with terminal according to the fourth embodiment of the present invention. It is a graph which compares and shows the contact resistance of Example 1 and Comparative Examples 1 and 2 of the present invention. It is a graph which compares and shows the adhesive force of Example 1 and Comparative Examples 1 and 2 of the present invention. It is the graph which showed the dependence to the crimping height (C / H) of the adhering force of a terminal and an electric wire, and contact resistance. It is the figure which showed the crimping | compression-bonding process of the conventional electric wire with a terminal.

Explanation of symbols

10 Electric wire 12 Core wire 20 Terminal 26 Core wire crimping part 26a, 26b Crimp piece for core wire
30 core wire side crimper 30a rear crimper 30b front crimper 40 core wire side anvil 70 core wire holding member

Claims (6)

When manufacturing an electric wire with a terminal in which an electrically conductive terminal is connected to an electric wire terminal in which a core wire made of an electrically conductive element wire is covered with an insulating covering material,
The core wire exposed from the electric wire is placed on a core wire crimping portion provided with crimping pieces standing opposite to both sides of the base portion extending from one end of the connection portion connected to the other terminal of the terminal. Then, the core wire crimping portion is received by a terminal receiving surface provided on the anvil, and divided into a plurality of portions in the axial direction of the electric wires arranged facing the anvil and placed on the core crimping portion of the terminal. The crimper is pushed down to a predetermined height in a state where the crimper integrally overlaps the terminal pressing surface that presses the core crimping portion of the terminal so that there is no step in the axial direction of the electric wire, and this terminal pressing surface and the terminal of the anvil The core wire connecting portion is clamped between the receiving surface, and the electric wire and the core wire connecting portion are generally crimped and connected uniformly.
Subsequently, the split crimper partially stays at the predetermined height and presses and fixes the core crimping portion, and the other portions of the split crimper are further pushed down from the predetermined height, and the core crimping portion is The terminal is further strongly pressed locally, and the terminal is crimped and connected to the core wire in a state where a portion pressed strongly from the whole radial direction and a portion pressed weakly in the axial direction are mixed in the axial direction. A method for producing a terminal-attached electric wire, characterized in that:   When some of the plurality of divided crimpers are further pushed down from the predetermined height, the divided crimpers located on the base side of the electric wire of the core wire crimping portion remain at the predetermined height and the electric wire of the core wire crimping portion. 2. The method of manufacturing an electric wire with a terminal according to claim 1, wherein the terminal is strongly pressed and connected to the core wire by further pressing down the divided crimper at the terminal side or the intermediate portion.   The terminal is strongly crimped to the core wire by the split crimper in which a corner portion formed by the base end side surface of the wire and the terminal pressing surface of the crimper at a portion further pushed down from the predetermined height of the plurality of split crimpers is chamfered. The method for manufacturing an electric wire with a terminal according to claim 1, wherein the electric wire is connected.   In a portion where a part of the plurality of divided crimpers presses the core wire connecting portion more strongly, the height of the crimping piece erected opposite to both sides of the base portion of the core wire crimping portion is set to The manufacturing method of the electric wire with a terminal characterized by making it lower than the height of the base side.   The electric wire with a terminal manufactured by the manufacturing method in any one of the said Claim 1 thru | or 4. A terminal crimping device for crimping and connecting the terminal to the core wire by pressing a terminal on which an electric wire is placed with a crimper and an anvil,
An anvil provided with a receiving surface for receiving the terminal; and a crimper disposed opposite to the receiving surface of the anvil. The crimper is divided into a plurality of parts in the axial direction of the electric wire connected to the terminal by crimping. A terminal crimping apparatus, wherein each of the divided crimpers can be separated and approached independently from the anvil.

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