JP2010244883A - Crimp terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a crimp terminal capable of suppressing extension of a terminal and an electric wire at over-crimping while securing a necessary adhesive performance. <P>SOLUTION: In the crimp terminal in which a conductor crimping part 12 is formed in a cross-sectional nearly U-shape with the bottom plate 13 and a pair of right and left conductor caulking pieces 14, 14, and on the inner face of the conductor crimping part, a plurality numbers of recess groove shape serrations extending in a direction orthogonal to the longitudinal direction of a conductor Wa are formed, the serration 16 is divided and formed only in the inner face of the conductor caulking piece except the inner face of the bottom plate, and by that, a plain part 17 without the serration is prepared on the inner face of the bottom plate between groups of the serrations. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a crimp terminal suitable mainly for use in connection with an aluminum electric wire.

  As this type of crimp terminal, those shown in FIGS. 10 and 11 are known (for example, see Patent Documents 1 and 2).

  As shown in FIG. 10, the crimp terminal 1 is formed by twisting together an electrical contact portion 2 having a through hole 2 a through which a fastening means such as a bolt (not shown) can pass, and a plurality of aluminum wires 6 a of an aluminum electric wire 5. And a crimping portion 3 having a substantially U-shaped cross section connected to the conductor (core wire) 6 by crimping. On the inner surface 3 a of the crimp portion 3, a plurality of concave groove-shaped serrations 4 extending in a direction orthogonal to the length direction of the conductor 6 are formed.

  As shown in FIG. 11, when the conductor 6 of the aluminum electric wire 5 is crimped to the crimping portion 3 of the crimping terminal 1 by crimping, the aluminum strand 6a of the conductor 6 is slid while being rubbed against the concave serration 4. By moving, the oxide film on the surface of the aluminum element wire 6a of the conductor 6 is destroyed, and adhesion between the exposed new surface (substrate) and the crimping part 3 of the crimping terminal 1 (in the contact surface between solids, A phenomenon in which solids stick to each other due to the bonding force exerted by atoms on the surface occurs, and electrical connection is achieved.

Japanese Patent Laying-Open No. 2007-173215 (FIG. 1) Japanese Patent Laying-Open No. 2003-249284 (FIG. 7)

  By the way, when crimping to an aluminum wire, compared to crimping to a normal copper wire, over-crimping (the deformation ratio of the cross section of the crimping portion is larger than that of a copper wire to obtain good electrical performance). It is necessary to perform such strong pressure bonding). This is because it is necessary to cause adhesion between the terminal material and the conductor while breaking the strong oxide film formed on the surface of the conductor.

  However, if over-compression is performed, as shown in FIG. 12, since the thickness of the terminal is reduced at the portion where the serration 4 is provided, the extension of the terminal and the conductor 6 of the wire in the axial direction of the wire due to the crimping ( (Indicated by an arrow in the figure) sometimes became too large. This is because the thin portion of the terminal extends better, and the conductor 6 of the electric wire is dragged by the extension of the terminal and extends well in that portion. If the extension of the terminal or the conductor of the electric wire becomes too large, it is necessary to enlarge the connector housing in order to accommodate the crimp terminal in the connector housing. This is contrary to the miniaturization required for connectors in recent years.

  In view of the above circumstances, an object of the present invention is to provide a crimp terminal that can suppress elongation of a terminal or an electric wire when over-compression is performed while ensuring necessary adhesion performance.

  In order to solve the above problems, the invention according to claim 1 is provided with a conductor crimping portion that is crimped and connected to a terminal of a conductor of an electric wire immediately after the electrical connection portion, and the conductor crimping portion is connected to the electrical connection. Formed in a substantially U-shaped cross-section with a bottom plate continuous from the section and a pair of left and right conductor crimping pieces that are extended on both the left and right sides of the bottom plate and are crimped so as to wrap the conductor disposed on the inner surface of the bottom plate In the crimp terminal in which a plurality of concave groove-shaped serrations extending in a direction perpendicular to the length direction of the conductor are formed on the inner surface of the conductor crimping portion, the plurality of serrations are formed on the bottom plate. A solid surface without serration is formed on the inner surface of the bottom plate that is divided and formed only on the inner surface of the conductor crimping piece excluding the inner surface, and is thereby sandwiched between serrations formed on the inner surface of the conductor crimping piece. Special feature It is set to.

  The invention according to claim 2 is the crimp terminal according to claim 1, wherein the end of the conductor crimping piece extends in the lengthwise end of the serration formed on the inner surface of the conductor crimping piece. The end located on the side is stopped in front of the tip of the conductor crimping piece, so that a serrated non-formation area remains on the inner surface of the tip end in the extending direction of the left and right conductor crimping pieces. It is characterized by being.

  The invention of claim 3 is the crimp terminal according to claim 1 or 2, wherein a convex portion is provided on the inner surface of the bottom plate sandwiched between serrations formed on the inner surfaces of the left and right conductor crimping pieces, The plain portion is provided on the upper surface of the convex portion.

  Invention of Claim 4 is a crimp terminal of any one of Claims 1-3, Comprising: The groove width of the said serration is 50-100% of the diameter of the strand which comprises the conductor of the said electric wire. It is characterized by being set to the size of the range.

  Invention of Claim 5 is the crimp terminal of any one of Claims 1-4, Comprising: It forms in the said right and left conductor crimping piece with respect to the expansion | deployment length of the left-right direction of the said conductor crimping part, respectively. The ratio of the total dimension of the length of the serrations is set in the range of 30% to 60%.

  According to the invention of claim 1, since the plain portion without serration is secured on the inner surface of the bottom plate of the U-shaped conductor crimping portion, the thin portion of the conductor crimping portion is reduced by the plain portion. The elongation of the terminal and the conductor can be suppressed. In particular, the presence of the plain portion on the bottom plate that receives a large pressure during crimping increases the effect of suppressing the elongation of the terminal and the conductor. Also, even if there is no serration in the bottom plate, there is serration on the inner surface of the side caulking piece, so that the conductor to be stretched slides on the edge of the concave groove serration, In the case of an aluminum electric wire, the oxide film on the surface of the aluminum conductor is surely broken, and the adhesion spreads from that point, so that the conductor crimping part and the conductor are joined with a wide adhesion area. . Accordingly, it is possible to suppress the elongation of the terminal and the conductor while causing the necessary adhesion as a whole, and there is not much dimensional change even when the terminal after crimping is stored in the connector housing. In this state, the crimp terminal can be stored, and it is not necessary to enlarge the connector housing.

  According to the invention of claim 2, since the serrated non-formation area is left on the inner surfaces of the tip portions of the left and right conductor crimping pieces, the strength of the tip of the conductor crimping pieces can be increased. Therefore, when caulking the conductor caulking piece so as to wrap the conductor, the tip of the conductor caulking piece can be strongly bited into the inside of the conductor, and both mechanical connectivity and electrical connectivity can be improved. .

  According to the invention of claim 3, since the convex portion is provided on the inner surface of the bottom plate sandwiched between the left and right serrations, the conductor that plastically deforms when the left and right conductor crimping pieces are crimped so as to wrap the conductor. Can be pushed to the side of the conductor crimping piece by the presence of the convex portion. Accordingly, it is possible to increase the pressing force when the conductor slides while being rubbed against the serration, thereby improving the bondability between the electric wire and the terminal. In particular, in the case of an aluminum electric wire, the oxide film on the conductor surface can be easily broken, so that the adhesion area can be increased and the bonding property can be improved.

  According to invention of Claim 4, since the groove width of a serration is set to the dimension of the range of 50-100% of the diameter of the strand which comprises the conductor of an electric wire, it has adhered to the surface of the strand. The oxide film can be efficiently peeled off at the edge of the serration, and the adhesion can be improved.

  According to invention of Claim 5, the ratio of the total dimension of the length of the 2nd serration respectively formed in the left and right conductor crimping pieces with respect to the development length of the conductor crimping part in the left-right direction is 30% to 60%. Therefore, it is possible to suppress the elongation of the terminal and the conductor while securing sufficient adhesion.

It is a perspective view of the crimp terminal of one embodiment of the present invention. (A) is a plan view showing only the rear portion of the crimp terminal, (b) is a cross-sectional view taken along arrow IIb-IIb in (a), and (c) is a cross-sectional view taken along arrow IIc-IIc in (a). FIG. It is a principal part expanded sectional view of the part which a serration and a conductor rub in the crimp terminal. It is a cross-sectional view of the crimping part of the crimping terminal and the conductor. It is a characteristic view which shows the comparison of the adhering force by the difference in the formation method of a serration. It is a characteristic view which shows the comparison of the full length of the terminal by the difference in the method of formation of a serration. It is a characteristic view which shows the comparison of the electrical resistance value by the difference in the method of formation of a serration. It is a block diagram of the crimp terminal of other embodiment of this invention, (a) is a principal part expanded view, (b) is a VIIIb-VIIIb arrow sectional drawing of (a), (c) is VIIIc- of (a). VIIIc arrow sectional drawing, (d) is a VIIId-VIIId arrow sectional drawing of (a). It is sectional drawing of the part which crimped the crimp terminal of the embodiment on the conductor. It is a perspective view which shows the conventional crimp terminal. It is a cross-sectional view of the part which crimped the electric wire of the crimp terminal. It is a simulation figure which shows the mode of the expansion of the serration part at the time of crimping | bonding the same crimp terminal to an electric wire, Comprising: (a) is sectional drawing which shows the state cut | disconnected by the perpendicular | vertical surface, (b) was cut | disconnected by the horizontal surface It is sectional drawing which shows a state.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 is a perspective view showing a configuration of a crimp terminal according to the embodiment, FIG. 2A is a plan view showing only a rear portion of the crimp terminal, and FIG. 2B is a plan view of FIG. IIb-IIb arrow sectional view, FIG. 2 (c) is a sectional view taken along arrow IIc-IIc in FIG. 2 (a), and FIG. 3 is an enlarged sectional view of a principal portion of a portion where serrations and conductors rub in the crimp terminal. 4 is a cross-sectional view of the crimp terminal and the crimp portion of the conductor.

  As shown in FIGS. 1 and 2, the crimp terminal 10 is manufactured by being subjected to tin plating after being entirely pressed with copper or a copper alloy. Immediately after that, the conductor crimping portion 12 that is crimped and connected to the end of an aluminum conductor Wa (hereinafter simply referred to as a conductor) of an aluminum wire W (hereinafter simply referred to as a wire), A covering caulking portion 15 for caulking a portion of W with the covering Wb is provided.

  In the figure, the arrow AB direction indicates the front-rear direction, which is the terminal longitudinal direction, and the arrow CD direction indicates the left-right direction. The aluminum electric wire W is composed of a conductor (core wire) Wa formed by twisting a plurality of aluminum wires Wc made of aluminum or aluminum alloy, and an insulation coating Wb covering the conductor Wa. Is connected to the end (front end) of the conductor Wa of the aluminum wire W such that the front-rear direction AB coincides with the longitudinal direction X of the conductor Wa of the wire W.

  The conductor crimping portion 12 includes a pair of left and right conductors that are crimped so as to wrap around the bottom plate 13 that is continuous from the electrical connection portion 11 and the conductor Wa that is provided on the left and right sides of the bottom plate 13 and is disposed on the inner surface 13a of the bottom plate 13. The fastening pieces 14 and 14 are formed in a substantially U-shaped cross section.

  On the inner surface of the conductor crimping portion 12, three serrations 16 having a groove shape extending in the direction Y orthogonal to the length direction X of the conductor Wa are arranged in the longitudinal direction X of the conductor Wa (the longitudinal direction AB of the terminal). Are formed at equal intervals. These three serrations 16 are divided and formed only on the inner surface 14a of the conductor crimping piece 14 excluding the inner surface 13a of the bottom plate 13. As a result, a plain portion 17 that is a blank portion without serration is provided on the inner surface 13a of the bottom plate 13 sandwiched between serrations 16 that are divided and formed on the inner surfaces 14a of the left and right conductor crimping pieces 14. .

  Of the end portions in the length direction of the serrations 16 formed on the inner surface 14 a of the conductor crimping piece 14, the end portion located on the leading end side in the extending direction of the conductor crimping piece 14 is the tip of the conductor crimping piece 14. Thus, a non-serrated non-formation area 18 is left on the inner surface of the distal end portion in the extending direction of the left and right conductor crimping pieces 14.

  Moreover, the groove width t of these serrations 16 is set to a dimension in the range of 50 to 100% of the diameter of the wire Wc constituting the conductor Wa of the electric wire W. Further, when the development length in the left-right direction of the conductor crimping portion 12 is L, the total dimension (L1 + L1) of the length L1 of the serrations 16 respectively formed on the left and right conductor crimping pieces 14 is 30 with respect to L. % To 50%, preferably about 40%.

  Specifically, the width of the plain portion 17 is set to about 20% of L, and L1 is set to about 20% of L.

  On the bottom plate 13 of the crimping portion 12 of the crimping terminal 10 configured in this manner, the conductor Wa exposed by peeling off the end of the aluminum electric wire W is placed, and as shown in FIG. When the clamping pieces 14 and 14 are crimped so as to enclose the conductor Wa and are crimped, as shown in FIG. 3, the inner surface of the conductor crimping portion 12 (in the figure, the inner surface 14a of the conductor crimping piece 14) by the pressing force applied from the outside. Only the conductor Wa is in pressure contact, and the crimp terminal 10 and the conductor Wa extend in the longitudinal direction of the conductor Wa.

  At that time, the wire Wc of the conductor Wa slides as indicated by an arrow while rubbing the edge of the serration 16, thereby destroying the oxide film on the surface of the wire Wc and exposing the new surface (substrate). Then, the newly formed surface and the inner surface of the conductor crimping portion 12 cause adhesion, whereby the conductor Wa is electrically connected to the conductor crimping portion 12 in a good state.

  By the way, when crimping to the aluminum electric wire Wa, it is necessary to perform over-compression. If over-compression is performed, the thickness of the crimp terminal 10 is reduced at the portion where the serration 16 is provided. In some cases, the extension of the crimp terminal 10 and the conductor Wa of the electric wire in the axial direction becomes too large. When this elongation becomes large, when the crimp terminal 10 is housed in a connector housing or the like, the crimp portion does not fit in a predetermined housing position of the housing. Therefore, it is necessary to enlarge the connector housing.

  In that regard, in the crimp terminal 10 of the present embodiment, the plain portion 17 without serration is secured on the inner surface 13a of the bottom plate 13 of the conductor crimp portion 12 having a U-shaped cross section. The elongation of the crimp terminal 10 and the conductor Wa can be suppressed by the amount of the 12 thin portions. In particular, the presence of the uncoated portion 17 in the bottom plate 13 that receives a large pressure during crimping increases the effect of suppressing the elongation of the crimp terminal 10 and the conductor Wa.

  In addition, although there is a plain portion 17 without serration on the bottom plate 13, there are serrations 16 on the inner surface 14 a of the conductor crimping piece 14 on both sides of the plain portion 17, so that it extends to the edge of the groove-like serration 16. When the conductor Wa to be slid slides while rubbing, the oxide film on the surface of the conductor Wa is surely broken, and the adhesion that hardly occurs in the plain portion 17 is caused by the adhesion of the conductor crimping portion 12 and the conductor Wa. It can be reliably raised at the side.

  Therefore, as a whole, it is possible to suppress the elongation of the crimp terminal 10 and the conductor Wa while causing as much adhesion as necessary, and even when the crimp terminal 10 after crimping is stored in the connector housing, The crimp terminal 10 can be stored in a state where there is not much dimensional change, and it is not necessary to enlarge the connector housing.

  Further, since the serrated non-formation area 18 is left on the inner surface of the tip of the left and right conductor crimping pieces 14, the strength of the tip of the conductor crimping piece 14 can be increased. Therefore, when the conductor crimping piece 14 is crimped so as to enclose the conductor Wa, the tip of the conductor crimping piece 14 can be strongly bitten into the conductor Wa (see FIG. 4), and mechanical connectivity and electrical Both connectivity can be enhanced.

  Further, since the groove width t of the serration 16 is set to a dimension in the range of 50 to 100% of the diameter of the wire Wc constituting the conductor Wa of the electric wire W, the oxidation adhering to the surface of the wire Wc. The film can be efficiently peeled off at the edge of the serration 16 and the adhesion can be improved.

  Further, the ratio of the total dimension L1 + L1 of the length L1 of the serrations 16 formed on the left and right conductor crimping pieces 14 to the development length L in the left-right direction of the conductor crimping portion 12 is set in a range of 30% to 60%. Therefore, the expansion of the crimp terminal 10 and the conductor Wa can be suppressed while ensuring sufficient adhesion.

  5, 6, and 7 are characteristic diagrams showing the results of comparison experiments between the crimp terminal of the embodiment of the present invention and the crimp terminal of the comparative example, and FIG. 5 shows the adhesion force due to the difference in the way of forming serrations. FIG. 6 is a characteristic diagram showing comparison of the total lengths of terminals according to differences in the manner of forming serrations, and FIG. 7 is a characteristic diagram showing comparison of electrical resistance values according to differences in the manner of formation of serrations.

  A sample M in each characteristic diagram corresponds to the crimp terminal of the present embodiment, and three serrations are formed in the conductor crimping portion, but the serration is divided into the right and left conductor crimping pieces. The crimp terminal is formed with a plain portion 17 without serration. In addition, the sample S is a crimp terminal having three serrations continuous to the conductor crimping portion, that is, a crimp terminal without the plain portion 17, as in the conventional product of FIG. 8. In FIG. 7, M1 and S1 are experimental data for the sample in the initial state, and M2 and S2 are experimental data for the sample after the durability test.

  These samples M and S were crimped under the same conditions to collect data.

  As a result, it was found from FIG. 5 that the fixing force is not different from that of the comparative example (conventional example equivalent product) S even when the plain portion 17 is provided (M).

  Also, from FIG. 6, when the compression ratio is extremely high, there is no difference between the sample M and the sample S, but in the range of a lower compression ratio (normal over-compression), the sample M is better. It has been found that the overall length elongation of the terminal can be suppressed and the change in dimensions can be suppressed.

  Further, FIG. 7 shows that when the compression ratio is increased, the resistance value of the sample S is increased, but the increase in the resistance value of the sample M can be suppressed regardless of the compression ratio.

  FIG. 8 is a configuration diagram of a crimp terminal according to another embodiment of the present invention, FIG. 8 (a) is a developed view of the main part, FIG. 8 (b) is a cross-sectional view taken along the line VIIIb-VIIIb of FIG. 8C is a sectional view taken along the line VIIIc-VIIIc in FIG. 8A, FIG. 8D is a sectional view taken along the line VIIId-VIIId in FIG. 8A, and FIG. It is sectional drawing of the part crimped to the conductor.

  As shown in FIG. 8, in the crimp terminal 20 of this embodiment, a convex portion 21 is formed on the inner surface 13a of the bottom plate 13 sandwiched between the three serrations 16 of the inner surfaces 14a of the left and right conductor crimping pieces 14, The plain portion 17 is provided on the upper surface of the convex portion 21. Since the other points are the same as in the above embodiment, the description thereof is omitted.

  As described above, when the convex portion 21 is provided on the inner surface 13a of the bottom plate 13 sandwiched between the left and right serrations 16, the left and right conductor crimping pieces 14 are crimped so as to wrap the conductor Wa as shown in FIG. Sometimes, the plastically deformed conductor Wa can be pushed to the side of the conductor crimping piece 14 as indicated by an arrow due to the presence of the convex portion 21. Accordingly, it is possible to increase the pressing force when the conductor Wa slides in the axial direction (direction perpendicular to the paper surface of FIG. 9) of the conductor Wa while being rubbed against the serration 16, and thereby the electric wire (conductor Wa) and the terminal Bondability of (conductor crimping part 12) can be improved. In particular, in the case of an aluminum electric wire, the oxide film on the surface of the conductor Wa can be easily broken by strong rubbing, so that the adhesion area can be increased and the bondability can be greatly improved. Moreover, since the effect | action which peels off the oxide film on the surface of the conductor Wa can be acquired also by the edge of convex part 21 itself, an adhesion area can be expanded greatly and improvement of joining property can be aimed at.

  In the above embodiment, three serrations 16 are provided in the front-rear direction of the terminal. However, the number of serrations 16 is not limited to three as long as the number is two or more.

  Moreover, in the said embodiment, although the case where the crimp terminal of this invention was connected to the aluminum electric wire W was described, even if it connects to a copper electric wire, the same effect can be exhibited.

DESCRIPTION OF SYMBOLS 10 Crimp terminal 11 Electrical connection part 12 Conductor crimping part 13 Bottom plate 13a Inner surface 14 Conductor crimping piece 14a Inner surface 17 Plain part 18 Non-formation area 20 Crimp terminal 21 Convex part W Aluminum electric wire Wa Aluminum conductor Wc Aluminum element wire

Claims (5)

Immediately after the electrical connection portion, there is provided a conductor crimping portion that is crimped and connected to the end of the conductor of the electric wire. The conductor crimping portion extends from the electrical connection portion to the left and right sides of the bottom plate. And a pair of left and right conductor crimping pieces that are crimped so as to wrap the conductor disposed on the inner surface of the bottom plate, and are formed in a substantially U-shaped cross section. In a crimp terminal in which a plurality of serrations in a groove shape extending in a direction orthogonal to the direction is formed,
The plurality of serrations are divided and formed only on the inner surface of the conductor crimping piece excluding the inner surface of the bottom plate, and are thereby sandwiched by the serrations formed on the inner surface of the conductor crimping piece. A crimp terminal, wherein a plain portion without serration is provided on an inner surface of the bottom plate. The crimp terminal according to claim 1,
Of the end portions in the longitudinal direction of the serrations formed on the inner surface of the conductor crimping piece, the end portion located on the leading end side in the extending direction of the conductor crimping piece is stopped before the tip of the conductor crimping piece. Accordingly, a serrated non-formation area is left on the inner surface of the extending direction front end portion of the left and right conductor crimping pieces. The crimp terminal according to claim 1 or 2,
A crimp terminal, wherein a convex portion is provided on an inner surface of the bottom plate sandwiched between serrations formed on inner surfaces of the left and right conductor crimping pieces, and the plain portion is provided on an upper surface of the convex portion. The crimp terminal according to any one of claims 1 to 3,
The crimp terminal, wherein the groove width of the serration is set to a size in the range of 50 to 100% of the diameter of the wire constituting the conductor of the electric wire. The crimp terminal according to any one of claims 1 to 4,
The ratio of the total dimension of the lengths of the serrations formed in the left and right conductor crimping pieces to the developed length in the left and right direction of the conductor crimping part is set in a range of 30% to 60%. Characteristic crimp terminal.

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