The present application claims priority to and incorporates by reference the entire contents of Japanese Patent Application No. 2019-071077 filed in Japan on Apr. 3, 2019.
The present invention relates to a terminal-equipped electric wire and a terminal crimping device.
Conventionally, there have been techniques for crimping a terminal to an electric wire. Japanese Patent Application Laid-open No. 2010-80194 discloses a technique of a terminal crimping device having a crimper including: a main body on which a sliding contact surface is formed; and a contact portion. The contact portion of Japanese Patent Application Laid-open No. 2010-80194 protrudes from the main body in both directions in which the electric wire extends, and further protrudes inward in a direction intersecting the sliding contact surface, and comes in contact with a wire barrel piece from both sides in an electric wire extending direction when the wire barrel piece is crimped to a core wire. The terminal crimping device of Japanese Patent Application Laid-open No. 2010-80194 is supposed to be able to suppress an increase in the length of the terminal fitting in the electric wire extending direction before and after crimping.
Here, there is still room for improvement in suppressing the lengthening of the crimp terminal due to crimping.
An object of the present invention is to provide a terminal-equipped electric wire and a terminal crimping device capable of suppressing lengthening of the crimp terminal due to crimping.
In order to achieve the above mentioned object, a terminal-equipped electric wire according to one aspect of the present invention includes an electric wire; and a crimp terminal including a core wire crimp portion crimped to a core wire of the electric wire, wherein the core wire crimp portion includes a bottom wall portion, and a crimping piece that extends in a direction intersecting the bottom wall portion from an end of the bottom wall portion in a width direction and that is wound around the core wire, a cross-sectional shape of the crimping piece is a curved shape convex toward a side opposite to the bottom wall portion, and a curved portion of the crimping piece includes a protrusion formed to protrude stepwise with respect to surrounding portions.
The above and other objects, features, advantages and technical and industrial significance of this invention will be better understood by reading the following detailed description of presently preferred embodiments of the invention, when considered in connection with the accompanying drawings.
Hereinafter, a terminal-equipped electric wire and terminal crimping device according to an embodiment of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited by the present embodiment. Moreover, components in the following embodiment include those that can be easily assumed by those skilled in the art or substantially identical.
An embodiment will be described with reference to FIGS. 1 to 8. The present embodiment relates to a terminal-equipped electric wire and a terminal crimping device.
As illustrated in
In the description of the crimp terminal 1 in the present specification, a connection direction with the counterpart terminal, that is, an insertion direction with respect to the counterpart terminal is referred to as a first direction L. The first direction L is the longitudinal direction of the crimp terminal 1. A width direction of the crimp terminal 1 is referred to as a second direction W. The second direction W is orthogonal to the first direction L. In the crimp terminal 1, a direction orthogonal to both the first direction L and the second direction W is referred to as a third direction H. The third direction H is a compression direction by an upper mold 50 when the crimp terminal 1 is crimped. The third direction H is a height direction of the crimp terminal 1.
The terminal connecting portion 11 is a portion electrically connected to a counterpart terminal. The shape of the terminal connecting portion 11 of the present embodiment is a rectangular tube shape. The core wire crimp portion 12 is a portion that is crimped to a core wire 61 of an electric wire 60. The electric wire 60 has the core wire 61 and a covering 62. Examples of the material of the core wire 61 include copper and aluminum. In the electric wire 60 to be crimped by the crimp terminal 1, the covering 62 at the end is removed to expose the core wire 61 by a predetermined length. The core wire 61 of the present embodiment is a group of a plurality of strands. Alternatively, the core wire 61 may be a single wire such as a coaxial cable. The crimp terminal 1 is crimped to the end of the electric wire 60 and thereby electrically connected to the exposed core wire 61.
The shape of the core wire crimp portion 12 before being crimped to the core wire 61 is a U-shape as illustrated in
As illustrated in
The terminal connecting portion 11 and the core wire crimp portion 12 are connected via an intermediate portion 14. The height of the intermediate portion 14 is lower than any of the height of the terminal connecting portion 11 and the height of the core wire crimp portion 12. The core wire crimp portion 12 and the covering crimp portion 13 are connected via an intermediate portion 15. The intermediate portion 15 includes a bottom wall portion 15a and a side wall portion 15b. The bottom wall portion 15a connects the bottom wall portion 21 of the core wire crimp portion 12 and the bottom wall portion 31 of the covering crimp portion 13. The side wall portion 15b extends from both sides of the bottom wall portion 15a. One side wall portion 15b connects the first crimping piece 22 and the third crimping piece 32. The other side wall portion 15b connects the second crimping piece 23 and the fourth crimping piece 33. The height of the side wall portion 15b is lower than any of the heights of the crimping pieces 22 and 23 of the core wire crimp portion 12 and the heights of the crimping pieces 32 and 33 of the covering crimp portion 13.
As illustrated in
The core wire crimp portion 12 and the covering crimp portion 13 are crimped to the electric wire 60 by the lower mold 40 and the upper mold 50 as illustrated in
The upper mold 50 is a terminal crimping mold that sandwiches the crimp terminal 1 and the electric wire 60 between the lower mold 40 and oneself and thereby crimps the crimp terminal 1 to the electric wire 60. The upper mold 50 sandwiches the core wire crimp portion 12 and the core wire 61 between the lower mold 40 and oneself and thereby crimps the core wire crimp portion 12 to the core wire 61. In addition, the upper mold 50 sandwiches the covering crimp portion 13 and the covering 62 between the lower mold 40 and oneself and crimps the covering crimp portion 13 to the covering 62. As illustrated in
The upper mold 50 of the present embodiment includes a first upper mold 70 illustrated in
As illustrated in
The first wall surface 72 and the second wall surface 73 are positioned away from each other downward in the third direction H. The upper end portion of the first wall surface 72 includes a first curved surface 74. The upper end portion of the second wall surface 73 includes a second curved surface 75. The first curved surface 74 and the second curved surface 75 are surfaces facing the lower mold 40 in the third direction H, and are curved upward. The first curved surface 74 and the second curved surface 75 are located in an inner part of the first wall surface 72 and the second wall surface 73 farthest from the lower mold 40. The first curved surface 74 and the second curved surface 75 are adjacent in the second direction W. The boundary between the first curved surface 74 and the second curved surface 75 forms a ridge 76 projecting downward.
As illustrated in
The magnitude of the radius of curvature of the second curved surface 75 differs between the portion on one side in the second direction W and the portion on the other side in the second direction W across the boundary portion 75a. In the second curved surface 75, the radius of curvature of the portion on the ridge 76 side of the boundary portion 75a may be relatively small.
The first curved surface 74 bends the first crimping piece 22 toward the second curved surface 75 and winds the first crimping piece 22 around the core wire 61. The second curved surface 75 bends the second crimping piece 23 toward the first curved surface 74 and winds the second crimping piece 23 around the core wire 61. This procedure forms a terminal-equipped electric wire 2 illustrated in
The first upper mold 70 of the present embodiment has a recess 77 as illustrated in
The first recess 78 and the second recess 79 according to the present embodiment have shapes each having a cylindrical space inside. That is, each of the first recess 78 and the second recess 79 has a circular cross-sectional shape of the section orthogonal to a depth direction. The cross-sectional shape of the first recess 78 and the cross-sectional shape of the second recess 79 are the same shape or substantially the same, for example. The depth of the first recess 78 is same as the depth of the second recess 79, for example.
The first recess 78 and the second recess 79 are adjacent in the width direction, that is, the second direction W. The center position of the first recess 78 in the first direction L may be the same as the center position of the second recess 79 in the first direction L. In the present embodiment, as illustrated in
The first crimping surface 71 includes an inclined end surface 80. The inclined end surface 80 is provided at one end of the first crimping surface 71 in the first direction L. The inclined end surface 80 is inclined with respect to the first direction L and spreads in the first direction L toward a main surface 70a. The main surface 70a is one of a pair of main surfaces of the first upper mold 70 and is orthogonal to the first direction L. The main surface 70a is a surface facing the covering 62 side of the electric wire 60 in the crimping process. In other words, the main surface 70a is a surface located on the base side of the core wire 61 in the crimping process. The recess 77 is provided at a position near the main surface 70a in the first direction L, for example. The recess 77 is arranged so as not to overlap the inclined end surface 80.
As illustrated in
The second crimping piece 23 includes a curved portion 23b and a base portion 23c. The base portion 23c is a portion extending from the bottom wall portion 21 in the third direction H. The cross-sectional shape of the base portion 23c is a substantially linear shape. The curved portion 23b is a portion on the tip side of the base portion 23c in the second crimping piece 23. The curved portion 23b is curved such that a tip 23a faces the bottom wall portion 21 in the third direction H. The first crimping piece 22 and the second crimping piece 23 are crimped to the core wire 61 while bringing an outer surface 22d of the first crimping piece 22 and an outer surface 23d of the second crimping piece 23 into contact with each other. A portion where the first crimping piece 22 and the second crimping piece 23 come in contact is formed into a groove 24. The groove 24 is a groove-shaped portion formed between the curved portions 22b and 23b, and extends in the first direction L.
As illustrated in
The first protrusion 25 and the second protrusion 26 protrude toward the side opposite to the bottom wall portion 21. The protruding direction of each of the first protrusion 25 and the second protrusion 26 is the third direction H, that is, a height direction of the crimp terminal 1. The first protrusion 25 and the second protrusion 26 may protrude in a direction slightly inclined with respect to the third direction H.
The first protrusion 25 and the second protrusion 26 are formed in the crimping process. In the crimping process, the core wire crimp portion 12 is crimped to the core wire 61 by the upper mold 50 and the lower mold 40. A part of the core wire crimp portion 12 enters the recess 77 when the core wire crimp portion 12 is crimped, whereby the first protrusion 25 and the second protrusion 26 are formed. A part of the first crimping piece 22 enters the first recess 78 in the crimping process, whereby the first protrusion 25 is formed. A part of the second crimping piece 23 enters the second recess 79 in the crimping process, whereby the second protrusion 26 is formed. Entrance of the part of the core wire crimp portion 12 into the recess 77 suppresses the lengthening of the crimp terminal 1 in the crimping process. Accordingly, the terminal-equipped electric wire 2 of the present embodiment can reduce the amount of lengthening of the crimp terminal 1, and can suppress variation in the amount of lengthening. According to the terminal-equipped electric wire 2 of the present embodiment, it is possible to suppress a situation in which the crimp terminal 1 jumps out of a cavity such as an electric junction box.
As illustrated in
As illustrated in
The first protrusion 25 and the second protrusion 26 face each other in the width direction, that is, the second direction W. The center position of the first protrusion 25 in the first direction L may be the same as the center position of the second protrusion 26 in the first direction L. In the present embodiment, as illustrated in
The positions of the first protrusion 25 and the second protrusion 26 in the first direction L may be a position on the covering crimp portion 13 side of the center of the core wire crimp portion 12, or may be a position on the terminal connecting portion 11 side of the center, for example. The first protrusion 25 and the second protrusion 26 are preferably formed in a region excluding a bell-mouth portion 27 in the core wire crimp portion 12. The bell-mouth portion 27 is a portion formed corresponding to the inclined end surface 80 of the first upper mold 70. The bell-mouth portion 27 is formed at the covering crimp portion 13-side end of the core wire crimp portion 12. The outer surface of the bell-mouth portion 27 is an inclined surface that is inclined with respect to the first direction L. The bell-mouth portion 27 is inclined so as to expand in the first direction L toward the covering crimp portion 13.
The first protrusion 25 of the present embodiment is formed in a region excluding the bell-mouth portion 27 in the first crimping piece 22. The second protrusion 26 is formed in a region excluding the bell-mouth portion 27 in the second crimping piece 23. In order to arrange the first protrusion 25 and the second protrusion 26 in this manner, the recess 77 is separated from the inclined end surface 80 as illustrated in
As described above, the terminal-equipped electric wire 2 of the present embodiment includes the electric wire 60 and the crimp terminal 1. The crimp terminal 1 includes the core wire crimp portion 12 that is crimped to the core wire 61 of the electric wire 60. The core wire crimp portion 12 includes the bottom wall portion 21 and the crimping pieces 22 and 23. The crimping pieces 22 and 23 extend in a direction intersecting the bottom wall portion 21 from the end of the bottom wall portion 21 in the second direction W, and are wound around the core wire 61.
The cross-sectional shape of each of the crimping pieces 22 and 23 is a curved shape that is convex toward the side opposite to the bottom wall portion 21. The curved portions 22b and 23b of the crimping pieces 22 and 23 respectively include the protrusions 25 and 26 protruding stepwise with respect to surrounding portions. In the crimp terminal 1 in which the protrusions 25 and 26 are formed, the lengthening of the crimp terminal 1 is suppressed in the crimping process. Since the volume corresponding to the protrusions 25 and 26 is released, the lengthening of the crimp terminal 1 in the first direction L is suppressed. Accordingly, the terminal-equipped electric wire 2 of the present embodiment achieves an effect that the lengthening of the crimp terminal due to crimping is suppressed. Furthermore, since the lengthening of the crimp terminal 1 is suppressed, it is possible to reduce variation in the length of the crimp terminal 1 in the first direction L.
In the terminal-equipped electric wire 2 of the present embodiment, the bell-mouth portions 27 are formed at the end portions in the first direction L of the crimping pieces 22 and 23. The protrusions 25 and 26 are formed in regions excluding the bell-mouth portion 27 in the crimping pieces 22 and 23. In the embodiment, the protrusions 25 and 26 are formed in a region on the terminal connecting portion 11 side of the bell-mouth portion 27 in the first direction L. Forming the protrusions 25 and 26 in the region excluding the bell-mouth portion 27 would prevent interference between the formation of the bell-mouth portion 27 and the formation of the protrusions 25 and 26.
The crimping pieces 22 and 23 of the present embodiment include the first crimping piece 22 and the second crimping piece 23. The first crimping piece 22 extends from one end of the bottom wall portion 21 in the width direction, while the second crimping piece 23 extends from the other end of the bottom wall portion 21 in the width direction. The core wire crimp portion 12 is crimped to the core wire 61 while bringing the outer surface 22d of the first crimping piece 22 and the outer surface 23d of the second crimping piece 23 into contact with each other. The protrusions 25 and 26 include the first protrusion 25 formed on the outer surface 22d of the first crimping piece 22 and the second protrusion 26 formed on the outer surface 23d of the second crimping piece 23. The first protrusion 25 and the second protrusion 26 face each other in the width direction of the bottom wall portion 21. This ensures symmetry in the crimp terminal 1, leading to reduction of variations in the performance of the crimp terminal 1. For example, it is possible to reduce the variation between the amount of lengthening on the first crimping piece 22 side and the amount of lengthening on the second crimping piece 23 side.
The crimp terminal 1 of the present embodiment has the covering crimp portion 13 that is crimped to the covering 62 of the electric wire 60. In the height direction of the crimp terminal 1, the tips 25a and 26a of the protrusions 25 and 26 are located lower than the top 13a of the covering crimp portion 13. Therefore, the protrusions 25 and 26 would not easily interfere with the cavity when the crimp terminal 1 is stored in the cavity.
The terminal crimping device 100 according to the present embodiment includes the lower mold 40 and the upper mold 50. The lower mold 40 supports the crimp terminal 1 having the core wire crimp portion 12 crimped to the core wire 61 of the electric wire 60, from below. The upper mold 50 has the first crimping surface 71 for winding the core wire crimp portion 12 around the core wire 61, and descending toward the lower mold 40 to crimp the crimp terminal 1 to the electric wire 60. In the first crimping surface 71, the portion facing the lower mold 40 has the recess 77 that is recessed stepwise with respect to the surrounding portion. In the embodiment, the first curved surface 74 and the second curved surface 75 have the recess 77. The upper mold 50 including the recess 77 can release a part of the core wire crimp portion 12 to the recess 77 in the crimping process, making is possible to suppress the lengthening of the crimp terminal 1.
A first modification of an embodiment will be described.
In a case where the recess 21a is formed in the bottom wall portion 21, the first protrusion 25 and the second protrusion 26 are preferably arranged so as not to overlap the recess 21a. The first protrusion 25 and the second protrusion 26 are formed at a position on the covering crimp portion 13 side of the recess 21a. The first protrusion 25 and the second protrusion 26 may be formed at a position on the terminal connecting portion 11 side of the recess 21a. Since there is no overlapping between the position of the recess 21a and the position of the protrusions 25 and 26 in the first direction L, it is possible to suppress the reduction in strength of the core wire crimp portion 12.
A second modification of an embodiment will be described.
As illustrated in
A third modification of an embodiment will be described.
As illustrated in
For example, the crimp terminal 1 is crimped to the core wire 61 so that the second crimping piece 23 overlaps the outside of the first crimping piece 22. In this case, for example, a protrusion 28 is formed on the second crimping piece 23 positioned on the outside. The protrusion 28 is formed at a top of the second crimping piece 23, for example. In other words, the protrusion 28 may be formed at a position farthest from the bottom wall portion 21 on the outer surface 23d of the second crimping piece 23. The protrusion 28 may be formed in plurality on the second crimping piece 23.
A fourth modification of an embodiment will be described. An anticorrosion resin film may be formed on the terminal-equipped electric wire 2. The resin film is formed so as to cover the tip 61a of the core wire 61 and the intermediate exposed portion 61b, for example. The resin film may be further formed in the groove 24 of the core wire crimp portion 12.
The shape, arrangement, number, or the like, of the protrusions are not limited to the shape, arrangement, number, or the like, of the protrusions 25, 26, or 28 exemplified in the above embodiment and the modification. The shape, arrangement, number, or the like, of the protrusions are appropriately determined in accordance with the crimped shape of the crimp terminal 1 with respect to the electric wire 60.
The contents disclosed in the above embodiments and modifications can be executed in appropriate combination with each other.
In the terminal-equipped electric wire according to the present embodiment, a protrusion protruding stepwise with respect to surrounding portions is formed on a curved portion of a crimping piece. According to the terminal-equipped electric wire of the present embodiment, it is possible to achieve an effect of releasing the volume corresponding to the protrusion formed at the time of crimping, leading to suppression of the lengthening of the crimp terminal.
Although the invention has been described with respect to specific embodiments for a complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art that fairly fall within the basic teaching herein set forth.
Number | Date | Country | Kind |
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2019-071077 | Apr 2019 | JP | national |