JP2001023751A - Manufacture of electric wire connecting terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate insertion of an electric wire end part and prevent disconnection by forming a preliminary bell mouth part with a preliminary bell mouth forming pin and finishing an electric wire end inserting tube part with a parallel pin of a punch. SOLUTION: The tip of a die pin is brought into contact with one end of a short wire material (a), and the other end of the short wire material (a) is strongly pressed with a pin of a first punch to form a straight tube part (b). The tapered projecting part of a preliminary bell mouth forming pin of a second punch is press-fitted into the end of the short wire material (a) facing an outward expanding opening part to form a preliminary bell mouth part (c"). The short wire material (a) having the preliminary bell mouth part (c") is set to a third die 15. The short wire material (a) is inserted and held into a through hole 17 so that the preliminary bell mouth part (c") is faced to an opening part 16 of one end. Then, a parallel pin 21 of a third punch 20 is press fitted into the preliminary bell mouth part (c") of the short wire material (a) facing the opening part 16 to form a bell-like electric wire end inserting tube part (c).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a terminal for connecting electric wires.

[0002]

2. Description of the Related Art For example, Japanese Patent Publication No. Sho 56-42113 and Japanese Patent Publication No. Sho 62-99
One disclosed in Japanese Patent Publication No. 90 is known. In this method of manufacturing the electric wire connection terminal, a copper round wire having a diameter of the electric wire connection terminal is cut into a short dimension that can form one electric wire connection terminal, and the copper wire is cut at both ends or one end of the short wire. This is to press-form the wire end insertion tube portion using a pin-shaped elongated rod member or a thin protruding rod portion smaller than the diameter of the wire. According to this manufacturing method, since cutting powder such as that generated by the cutting process is not generated, it is possible to work under a favorable working environment, and it is possible to manufacture at low cost with simple equipment without material loss. .

[0003]

However, in the wire connection terminal having the above-described wire end insertion tube portion, the tube end of the tube portion is so thin that it is difficult to insert the wire end portion. In addition, the electric wire inserted and crimped into the pipe portion sometimes swings frequently, and in this case, the electric wire may be bent at the edge of the pipe with a small radius of curvature and disconnected.

Accordingly, the present invention relates to the above-mentioned Japanese Patent Publication No. Sho 56-4.
The technology of the method for manufacturing a wire connection terminal described in Japanese Patent Publication No. 2113 is further developed and improved, and a wire end insertion tube at one end of the wire connection terminal is formed in a trumpet shape to facilitate insertion of the wire end. It is another object of the present invention to provide a method for manufacturing a wire connection terminal capable of preventing disconnection. Another object of the present invention is to provide a method of manufacturing a wire connection terminal that can easily form a trumpet-shaped tube.

[0005]

As shown in FIGS. 1 to 6, a method for manufacturing an electric wire connection terminal according to the present invention comprises connecting a conductive metal wire having a diameter of an electric wire connection terminal to one electric wire. It is cut to a short dimension capable of forming the connection terminal A, and when forming a wire end insertion tube c having a trumpet-shaped tube opening c ′ at one end of the short wire a, the wire is extended outward at one end. A punch 12 having a die 7 having a through hole 9 having a hole-like opening 8 and a preliminary wrapper mouth forming pin 14 having a tapered projection 13 formed at the tip thereof to conform to the internal shape of the flared pipe opening c '. The short wire a is inserted into the through hole 9 of the die 7 from the outwardly extending opening 8 at one end thereof, and is held so as not to move in the opening direction X at the other end. On the other hand, the tapered projection 13 of the punch 12 faces the inside of the outwardly expanding opening 8. Press-fitting into one end of the short wire rod a, thereby expanding the one end outward along the inner surface of the cone of the outwardly expanding opening 8 to form a spare flapper opening c #; A step of extracting the tapered projection 13 of the punch 12 from the preliminary wrapper opening c #, and extracting a short wire a having the preliminary wrapper opening c # from the die 7 into the through hole 17 of another die 15. One end opening 16 of this
And a punch 2 having a thin parallel pin 21 while holding the other end so as not to move in the opening direction X.
No. 0 of the parallel pin 21 is press-fitted into the spare wrapper opening c # of the short wire a facing the inside of the one end opening 16 of the through-hole 17 so that the spare wrapper opening c # side of the short wire a is in contact with the spare pin. Forming the wire end insertion tube portion c while protruding outward from the one end opening 16 of the die 15.

[0006]

The wire end insertion tube portion of the wire connection terminal is formed in a trumpet shape in which the mouth portion is expanded outward.
The end of the wire can be easily inserted into the tube from the trumpet-shaped mouth, and even if the end of the wire crimped into the tube crimps swings, The bending stress concentration can be reduced, so that it can be well protected from a disconnection accident.

[0007] In forming the wire end insertion tube, a preliminary wrapper mouth forming pin is first formed to form a spare wrapper mouth, and then the wire end insertion tube is finished with a punch parallel pin. Since the process is performed through the process, the trumpet-shaped wire end insertion tube can be easily formed. In the step of forming the spare wrapper mouth portion, the outer surface of the tapered protrusion of the spare wrapper mouth forming pin comes into close contact with the inner surface of the spare wrapper mouth portion due to strong surface pressure contact, but the short wire of the tapered protrusion is formed. Since the press-fit depth into the spare wrapper mouth is shallow, the tapered projection of the spare wrapper mouth forming pin can be easily pulled out from the spare wrapper mouth of the short wire after the formation of the spare wrapper mouth. In the finishing process of the wire end insertion tube part of the trumpet shape, the parallel pin of the punch is pressed deeply into the spare trumpet opening of the short wire, but at this time, the parallel pin may bite into the inner surface of the spare trumpet opening. Therefore, the parallel pin of the punch can be easily extracted from the short wire even after the formation of the tube portion, and there is no possibility of breaking the parallel pin at the time of extraction.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a method for manufacturing a wire connection terminal according to the present invention will be described with reference to the drawings. FIG. 8 is a sectional view of an electric wire connection terminal manufactured according to an embodiment of the present invention. This wire connection terminal A has a straight wire end insertion tube portion b at one end, a trumpet-shaped wire end insertion tube portion c at the other end, and a wire end portion between both pipe portions b and c. Partition walls d for restricting insertion are formed respectively. The trumpet-shaped wire end insertion tube c has a trumpet-shaped tube opening c ′.

Next, an example of a method of manufacturing the electric wire connection terminal having the above-described structure will be described in the order of the manufacturing steps with reference to FIGS.

First, a conductive metal wire such as a copper round wire having the same diameter as the outer diameter of a desired wire connection terminal A is cut into a short length capable of forming one wire connection terminal A, thereby obtaining a short wire material. a is formed.

Next, the short wire a is transferred to the manufacturing apparatus shown in FIG. This manufacturing apparatus includes a first die 1 and a first punch 2. The first die 1 has a through hole 3 that matches the outer diameter of the wire connection terminal A. And
The first die 1 has a die pin 4 and a pipe 5. The die pin 4 is formed into a diameter that matches the inner diameter of the straight wire end insertion tube portion b of the wire connection terminal A, and is inserted into the through hole 3.

The pipe 5 has an outer diameter that matches the inner diameter of the through hole 3 and is fitted on the outer periphery of the die pin 4 and inserted into the through hole 3. The portion 5a is inserted so as to be shallower than the insertion depth of the tip 4a of the die pin 4. As a result, the inner peripheral wall of the through hole 3 of the die 1 and the outer periphery of the die pin 4 and the tip 5a of the pipe 5
A space portion S for forming a straight tube portion is formed in between.

On the other hand, the first punch 2 has a pin 6 having a thickness corresponding to the through hole 3 of the first die 1.

Thus, as shown in FIG. 1, the short wire a is inserted into the through hole 3 of the first die 1 through one end opening thereof, and one end of the short wire a is connected to the tip 1 of the die pin 4.
4a.

Next, as shown in FIG. 2, the pin 6 of the first punch 2 is advanced and inserted into the through hole 3 of the first die 1 from one end opening of the first die 1. Press strongly. As a result, the material at one end of the short wire a plastically flows into the space S to form a straight tube b, and the opening edge b ′ of the tube b is connected to the tip of the pipe 5. It contacts the part 5a.

Next, the pins 6 of the first punch 2 are extracted from the through holes 3 of the first die 1. Thereafter, the short wire a formed with the straight wire end insertion tube b is pulled out from the through hole 3 of the first die 1.

Next, as shown in FIG. 3, a short wire a having a straight wire end insertion tube b at one end is set on a second die 7. The second die 7 has a through hole 9 having an outwardly extending opening 8 at one end, and the die pin 10 and the pipe 11 are formed in the through hole 9 when the die pin 4 and the pipe 5 of the first die 1 are used. Is inserted in the same state as. The short wire a having a straight wire end insertion tube portion b formed at one end thereof is inserted into the through hole 9 of the second die 7 from the outwardly expanding opening 8 at one end thereof, and the tube portion is inserted. b
Into the tip side of the die pin 10 and the pipe b
Is brought into contact with the tip 11a of the pipe 11. As a result, the short wire a having the straight wire end insertion tube b formed at one end thereof has the end a ′ on the opposite side to the tube b facing the inside of the flared opening 8. The other end of the through hole 9 is inserted and held in the through hole 9 so as not to move in the opening direction X. The second punch 12 which is a counterpart of the second die 7 has a pre-wrapper opening forming pin 14, and the tip of the pre-wrapping opening forming pin 14 has a trumpet-shaped pipe opening c ′ (see FIG. 8). A tapered projection 13 conforming to the shape is formed.

Next, as shown in FIG.
Of the short wire rod a facing the inside of the flared opening 8 of the through hole 9 by press-fitting the tapered projection 13 of the spare flapper opening forming pin 14 into the end a '. The outer opening 8 is expanded outward along the inner surface of the cone to form a spare flapper opening c #. FIG. 7 shows a short wire a formed with the spare wrapper mouth c # and the straight wire end insertion tube b.

After the formation of the spare wrapper opening, the second punch 1
The second pre-wrapper opening forming pin 14 is extracted from the pre-wrapper port c #. At this time, the outer surface of the tapered projection 13 of the auxiliary wrapper opening forming pin 14 is in contact with the inner surface of the auxiliary wrapper opening c # due to strong surface pressure contact. Since the press-fit depth of the tapered projection 13 with respect to 〃 is shallow, the tapered projection 1 of the
3 can be easily extracted from the spare wrapper mouth c # of the short wire a.

Short wire a having a spare flapper opening c #
Is pulled out of the through-hole 9 of the second die 7 and then set on the third die 15 as shown in FIG. Like the second die 7, the third die 15 has a through-hole 17 having an opening 16 at one end extending outward, and a die pin 18 and a pipe 19 are formed in the through-hole 17. The die 7 is inserted in the same state as the die pin 10 and the pipe 11. The short wire a formed with the spare wrapper mouth c # and the straight wire end insertion tube b is inserted into the through hole 17 of the third die 15 from the opening 16 at one end thereof. The pipe b is inserted into the tip of the die pin 18 and the opening edge b ′ of the pipe b is inserted into the tip 1 of the pipe 19.
9a. As a result, the short wire a is inserted into the through-hole 17 so that the spare trumpet opening c # faces the opening 16 at one end and does not move in the opening direction X at the other end of the through-hole 17. Inserted and held. A third punch 20, which is a counterpart of the third die 15, has a parallel pin 21 thinner than the short wire a.

Next, as shown in FIG.
Is inserted into the spare wrapper opening c # of the short wire a facing the opening 16 so that the spare wrapper opening c # side of the short wire a is opened to the opening 16 of the third die 15. Trunk-shaped wire end insertion tube c protruding outward from
To form

After forming the trumpet-shaped tube portion, the third punch 20
Of the parallel pin 21 of the completed wire connection terminal A in the through hole 17 from the spare wrapper mouth c #. Finally,
The wire connection terminal A is pulled out from the through hole 17.

[0023]

According to the present invention, the trumpet-shaped wire end insertion tube is formed so that its mouth is formed in a flared shape expanding outward. Can be easily inserted into the wire end insertion tube from the portion, and the wire connection operation can be performed efficiently. In addition, even when the wire end inserted and crimped into the wrapper-shaped wire end insertion tube oscillates, the bending stress concentration in the wrapper-shaped pipe mouth can be reduced, so that it is well protected from disconnection accidents. It can be advantageous.

To form a trumpet-shaped wire end insertion tube, a spare trumpet opening forming pin is used to form a spare trumpet opening, and then a trumpet-shaped wire end insertion tube is formed using a parallel pin of a punch. It is performed through a two-stage process of finishing.
Therefore, it is possible to easily form the trumpet-shaped wire end insertion tube portion, and to form a relatively deep trumpet-shaped wire end insertion tube portion of the punch deeply pressed into the short wire. There is also an advantage that the parallel pin can be easily extracted from the short wire without breaking.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a state where a short wire is inserted into a first die.

FIG. 2 is a sectional view showing a state in which a pin of a first punch is pressed against a short wire in a first die to form a straight tube at one end of the short wire.

FIG. 3 is a cross-sectional view showing a state in which a short wire having a straight tube portion is inserted into a second die.

FIG. 4 is a cross-sectional view of a state in which a spare wrapper opening forming pin is formed by press-fitting a preliminary wrapper opening forming pin into the other end of the short wire in the second die.

FIG. 5 is a cross-sectional view of a state where a short wire having a straight tube portion and a spare wrapper mouth portion is inserted into a third die.

FIG. 6 is a cross-sectional view of a state in which a parallel pin of a third punch is press-fitted into a spare wrapper opening of a short wire in a third die to form a wrapper-shaped tube.

FIG. 7 is a cross-sectional view of a semi-finished product of the wire connection terminal.

FIG. 8 is a cross-sectional view of a completed wire connection terminal.

[Explanation of symbols]

 Reference Signs List A A terminal for electric wire connection a Short wire rod c Wrap-shaped tube end for insertion of wire end c 'Wrap-shaped tube mouth c〃 Spare wrapper mouth 7,15 die 8 Spread-out opening of die 7,9 die 7 through hole 12 and 20 punch 13 tapered projection 14 preparatory horn opening forming pin 16 one end opening of die 15 17 through hole of die 15 21 parallel pin of punch 20

Claims (1)

[Claims] 1. A conductive metal wire having a diameter of an electric wire connection terminal is cut into a short length capable of forming one electric wire connection terminal, and a trumpet-shaped pipe opening is formed at one end of the short wire. In forming a wire end insertion tube portion having a through hole, a die having a through hole having an outwardly extending opening at one end, and a tapered projection at the tip that matches the internal shape of the trumpet-shaped tube mouth portion. And a punch having a formed pre-wrapper mouth forming pin, wherein the short wire is inserted into the through hole of the die from the outer flared opening at one end thereof and moved toward the other opening. While holding the punch, the tapered projection of the punch is press-fitted into one end of a short wire rod facing the outside opening of the through hole, so that the one end is the conical inner surface of the outside opening. Spread outwards to form a spare wrapper mouth Extracting the tapered protrusion of the punch from the spare wrapper opening, extracting the short wire having the spare wrapper opening from the die, and opening one end of the short wire into the through hole of another die. The parallel pin of the punch having the thin parallel pin is inserted into the through hole at the other end, and the parallel pin of the punch having the thin parallel pin is held in the one end opening of the through hole. Forming a wire end insertion tube while pressing the short wrapper mouth side of the short wire rod outwardly from one end opening of the die by press-fitting the wire. Manufacturing method of connection terminal.