JP4728986B2 - Terminal crimping structure for ultra-fine wires for automobiles - Google Patents

Description

  The present invention crimps a terminal to an electric wire used for wiring in an automobile, in particular, a very thin electric wire having a size of 0.22 sq or less (the diameter of the conductor portion is 0.55 mm or less) using copper or a copper alloy for a conductor portion. The present invention relates to a terminal crimping structure.

In general, copper wires are used for electric wires used in automobile wire harnesses in view of characteristics such as conductivity and strength. The terminal made of is crimped and used by inserting and fitting the inter-terminal connection portion of the terminal into an electrical connector. As shown in Patent Document 1, the terminal wire connection portion includes an insulation barrel for crimping the insulation coating portion of the wire, and a wire barrel for crimping the conductor portion of the wire in front of the insulation barrel. The form is well known. With the wire positioned on this terminal, lower the crimping jig and bend both ends of each barrel inward, so that the tip of the insulation barrel is the insulation coating and the tip of the wire barrel is the conductor. It is crimped by crimping.
On the other hand, in Patent Document 2, when aluminum is used for the conductor portion, an oxide film is formed to lower the electrical continuity characteristics. However, when the compression ratio is increased, the electric wire holding force is lowered. Therefore, the wire barrel is formed by dividing the wire barrel into a wire holding crimp barrel and a wire conducting crimp barrel, and the wire conducting crimp barrel is crimped at a lower height than the wire holding crimp barrel. An invention has been disclosed in which the electric wire is securely held by the electric wire holding barrel while the front electric wire conducting barrel is crimped at a high compression rate to break the oxide film and achieve sufficient electric conduction. .

JP 2005-174896 A JP-A-2005-50736

However, when copper or copper alloy such as tough pitch copper or tin-containing copper is used for the conductor part and the wire size is 0.22 sq or less (the diameter of the conductor part is 0.55 mm or less), the compression rate is reduced. If the value is small, the terminal crimping strength becomes very low (that is, the conductor is easily cut). However, in order to secure the terminal crimping strength, the area ratio before and after crimping (the cross-sectional area of the conductor after crimping / the cross-sectional area of the conductor before crimping, also referred to as the compression ratio and the area reduction ratio. The same applies to the present invention hereinafter. ) As large as 95%, the resistance of the crimping part increases due to environmental changes, causing problems in conduction, and cannot be used for automobiles. Although it is conceivable to form the wire barrel separately for holding and conducting as in Patent Document 2, the rear side is crimped at a normal compression rate and the front side is compressed at a higher compression rate, respectively. Even if it is suitable for an aluminum electric wire, sufficient terminal crimping strength cannot be ensured for an extremely fine copper electric wire.
Therefore, at present, the area ratio is managed within the range of 75% to 95%, and the usage limit is set, so that it is used only for a specific application.

  Therefore, the present invention provides a terminal crimping structure that can satisfy both conduction and holding power even in an ultrafine electric wire using such copper or copper alloy as a conductor part, and is excellent in usability. It is aimed at.

In order to achieve the above object, the invention according to claim 1 is characterized in that the wire barrel includes a front portion where the area ratio before and after crimping of the conductor cross-sectional area is 75% or more and less than 95%, and the area ratio is 95%. It is characterized in that it is pressure-bonded so as to be formed in two stages with a rear portion of 99% or less.
In addition to the object of the first aspect of the present invention, the front portion and the rear portion of the wire barrel are separated by a notch in order to easily and accurately set the difference in front and rear area ratio. It is characterized by this.

According to invention of Claim 1, since the front part of a wire barrel has crimped | bonded the conductor part strongly, electroconductivity and holding | maintenance become favorable. On the other hand, as the conductor part is strongly crimped, the conductor part is easily cut by pulling the electric wire, but since the rear part of the wire barrel is crimping the conductor part more loosely, stress due to the pulling of the electric wire is applied to the front part. In addition, even if the conductor portion is cut at the front portion, the electrical conductivity and the retaining property are maintained at the rear portion.
That is, even if it is a very fine electric wire, the conduction | electrical_connection and holding | maintenance are performed suitably, crimping | bonding intensity | strength increases and the possibility of a fracture | rupture of an electric wire also becomes small. Accordingly, the range of use is expanded and the usability is also improved.
According to the second aspect of the present invention, in addition to the effect of the first aspect, the difference in the area ratio between the front and the rear can be easily and accurately set by cutting, and a more stable connection state can be maintained.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an explanatory view showing an example of the terminal crimping structure of the present invention, with the upper side being a plane and the lower side being a side surface. In FIG. 1, reference numeral 1 denotes a terminal, 10 denotes an electric wire, and the terminal 1 is connected to an inter-terminal connection portion 2 to be inserted and fitted into an electric connector (not shown) and to the rear (right side in the figure). Are connected to each other, and the wire connection portion 3 includes an insulation barrel 4 for crimping the insulation coating portion 11 of the wire 10 from the left and right, and a conductor of the wire 10 in front of the insulation barrel 4. It has the form which has the wire barrel 5 which crimps | bonds the part 12 from right and left. In addition, for example, the conductor 10 has a conductor portion 12 having a diameter of 0.55 mm, and a Cu—Sn based alloy or a Cu—Ni—Si based alloy is preferably used.

The crimped wire barrel 5 is provided with a step in which the front portion 6 has a lower vertical height than the rear portion 7 at the substantially central portion in the front-rear direction. That is, the area ratio before and after the crimping of the conductor portion 12 in the front portion 6 is set in the range of 75% or more and less than 95% of the conventional, and the area ratio of the conductor portion 12 in the rear portion 7 is 95% or more and 99% or less. The range is set. By setting the front and rear area ratios, the front portion 6 exhibits the conduction and holding functions, and the rear portion 7 exhibits the holding functions.
Note that this area ratio is managed by the height of the crimped portion, generally called the crimp height value. FIG. 2 shows the cross section of the front portion 6 on the left side and the cross section of the rear portion 7 on the right side. Thus, the crimp height value Ha of the front half portion 6 is small and the crimp height value Hb of the rear portion 7 is large. It has become.

The provision of the step in the wire barrel 5 is performed by a crimping process as shown in FIG. First, as shown in FIG. 2A, the terminal 1 is fixed on the base 20 of the crimping machine, and the electric wire 10 is interposed between the wire barrel 5 having the U-shaped conductor portion 12 and the insulating covering portion 11. Is positioned at a predetermined position located between the insulation barrels 4.
Next, the crimping jig 21 is lowered from above. The crimping jig 21 has a well-known structure in which a cross-section has an inverted V-shape and a crimping groove whose deepest portion protrudes in an M-shape is formed. Here, the front part 6 and the rear part of the wire barrel 5 are here, respectively. 7. Corresponding to the insulation barrel 4, three crimping parts 22 to 24 having crimping grooves having different depths in three stages are formed. Therefore, when the crimping jig 21 is lowered as shown in FIG. 5B, the end portions of the barrels are guided to the center by the crimping grooves of the corresponding crimping portions 22 to 24 and curled inward, and the crimping is completed. As shown in FIG. 5C, the front portion 6 and the rear portion 7 having different heights are formed in the wire barrel 5.

  Thus, according to the terminal crimping structure of the said form, the wire barrel 5 becomes the front part 6 from which the area ratio before and behind crimping becomes 75-95%, and the said area ratio becomes 95-99%. Since the front portion 6 of the wire barrel 5 is pressure-bonded so as to be formed in two stages with the rear portion 7, the conductor portion 12 is strongly pressure-bonded, and the electrical conductivity and the holding property are improved. On the other hand, since the conductor portion 12 is strongly crimped, the conductor portion 12 is easily cut by pulling the electric wire 10, but the rear portion 7 of the wire barrel 5 crimps the conductor portion 12 more loosely. The stress applied by the tension of 10 can be alleviated, and even if the conductor portion 12 is cut at the front portion 6, the continuity and the retaining property are maintained at the rear portion 7. That is, even if it is a very fine electric wire, the conduction | electrical_connection and holding | maintenance are performed suitably, crimping | bonding intensity | strength increases and the possibility of a fracture | rupture of an electric wire also becomes small. Accordingly, the range of use is expanded and the usability is also improved.

In addition, in the said form, although it is set as the structure which crimps | bonds a wire barrel by the height of two steps using the terminal similar to the past, it is a substantially intermediate part of the wire barrel 5 like the terminal 1a shown to FIG. 4 (A). It is also possible to provide a notch 8 from above and to form a fork between the front part 6 and the rear part 7 in advance. Other configurations are the same as the previous embodiment.
Therefore, also in this modified example, the crimping jig 21 provided with the three crimping portions 22 to 24 having different depths of the crimping grooves is lowered as shown in FIG. When the portion 6, the rear portion 7 and the insulation barrel 4 are respectively crimped, the area ratio of the front portion 6 is set in the range of 75% or more and less than 95% as shown in FIG. The area ratio of the rear portion 7 can be set in the range of 95% to 99%.

  As described above, even in the terminal crimping structure of the above-described modified example, even if it is an extremely thin electric wire, the conduction and holding thereof are suitably performed, the crimping strength is increased, the risk of breaking the electric wire is reduced, and the use range is expanded. Convenience is improved. In particular, since the front portion 6 and the rear portion 7 of the wire barrel 5 are separated by the notch 8, a difference in front and rear area ratio can be easily and accurately formed, and a more stable connection state can be maintained. Become.

Moreover, in the said form and modification, although the front part and the latter half part of a wire barrel are divided into substantially equal parts, according to the diameter of a conductor part, the length of a wire barrel, etc., a front part is made from a rear part. Of course, it is possible to make it longer or vice versa.
In addition, the size of the electric wire and the diameter of the conductor part are not limited to the above forms, and can be appropriately changed as long as the electric wire size is 0.22 sq or less (the conductor part diameter is 0.55 mm or less). It is not limited to the said form, such as making a connection part into a male shape.

It is explanatory drawing of a terminal crimping | compression-bonding structure, an upper side shows a plane and the lower side shows a side surface, respectively. It is sectional drawing of a wire barrel, and the left shows a front part and the right shows a back part, respectively. (A)-(C) is explanatory drawing which shows a terminal crimping | compression-bonding process, respectively. (A)-(C) is explanatory drawing which shows the terminal crimping process in a modification, respectively. It is explanatory drawing of the terminal crimping structure in the example of a change, and the upper side shows a plane and the lower side shows a side surface, respectively.

Explanation of symbols

  1, 1a ··· Terminals 2 · · Inter-terminal connection portion 3 · · Wire connection portion 4 · · Insulation barrel 5 · · Wire barrel 6 · · Front portion 7 · · Rear portion 8 · · · Incision 10... Electric wire 11.. Insulation coating part 12.. Conductor part 20.

Claims (2)

Copper or copper alloy is used for the conductor part, and the ultra-fine electric wire for automobiles having a conductor part diameter of 0.55 mm or less is attached to the insulation barrel for crimping the insulation coating part of the wire, and in front of the insulation barrel. It is a terminal crimping structure of an automotive fine wire that is crimped to a terminal having a wire barrel that crimps the conductor part,
The wire barrel is divided into two stages: a front portion where the area ratio of the conductor cross-sectional area before and after pressure bonding is 75% or more and less than 95% and a rear portion where the area ratio is 95% or more and 99% or less. A terminal crimping structure for an ultrafine electric wire for automobiles, characterized in that the crimping is performed to form each.   The terminal crimping structure for an ultrafine electric wire for an automobile according to claim 1, wherein the front portion and the rear portion of the wire barrel are separated by cutting.

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