JPH0340470Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Field of Application) The present invention relates to an improvement of a die used in a butt cold welding machine for wire rods, particularly thin wires.

(Prior art) In the case of butt cold welding of wire rods, pressure welding cannot be performed if foreign matter such as oil or dust adheres to the butt surfaces of the wire rods, so initially the butt surfaces are cut with a knife or the butt surfaces are After removing foreign matter with a buff etc.
They were gripped with a die and pressed together to make pressure contact.

However, the above-mentioned method has poor workability such as cutting and buffing the wire, and an improved method called "multi-stage pressing" was developed. In this method, by pressing the wire 3 to 5 times in succession, foreign matter on the abutting surfaces is pushed out into the press burr, and the wire is press-bonded in a place where there is no burr inside the wire.

FIG. 1 shows a die portion of a conventional multi-stage cold press welding machine, and only the die shows a cross section taken at a hole for gripping a wire.

The dice consist of four pieces, 1a, 1b, 1c, and 1d. 2a, 2b, 2c, and 2d are fingers, which are not shown, but are rotated and pressed by a spring in the direction of arrow A with the pin 3 as a fulcrum, and prevent the wire rod inserted into the die from retreating and allow it to move forward. It is something.

Spring 4a, 4b, 4c, 4d are four dice 1
a, 1b, 1c, and 1d are pressed in the direction that they are separated from each other.

5a and 5b are V blocks, which are pressed in the direction of the arrow R with a lever as described later, thereby pressing the die with the V surface and gripping the wire with the die, and then pressing the wire in the axial direction to cool it. It performs pressure welding. The V-blocks 5a, 5b and the dies 1a, 1b, 1c, 1d are incorporated in a recessed portion of the main body 6, and move using the side surface 7 of the recessed portion as a guide.

The movement of the die during cold welding using the cold welding machine having such a configuration will be explained with reference to FIGS. 1A to 1D.

Wire rod 10 to be cold welded as shown in Fig. 1A
a, 10b as fingers 2a, 2b and 2c,
Insert into the die via 2d.

As shown in FIG. 1B, by pressing the V blocks 5a and 5b in the direction of the arrow with a lever described later, the die also moves in the direction of the arrow.
Grip the wire rods 10a and 10b with a die.

As shown in FIG.
When b is further pressed in the direction of the arrow, the die moves along the slope 11 of the V-block to the wire rods 10a,
The abutting surfaces of the wire rods 10b are moved in the direction of pressing each other (in the direction of the arrow), and the pressed portion of the wire is burr 1.
It becomes 2.

As shown in FIG. 1D, V blocks 5a, 5
When b is returned to the direction of the arrow, springs 4a, 4b, 4
c and 4d (see FIG. 1), the die moves in the direction of the arrow and returns to the state shown in FIG. 1A.

At this time, the fingers 2a, 2b and 2
Stop at c, 2d. At this time, due to the friction between the tip of the finger and the wire, the finger tries to rotate in the biting direction using the pin 3 as a fulcrum, thereby preventing the wire from retreating.

Repeat the above steps 3 to 5 times to complete cold pressure welding by multi-stage pressure welding.

(Problem to be solved) In the multi-stage pressure welding of wire rods as described above, the first
As shown in Figure A, when inserting the wire rod to be cold welded into the wire rod gripping part 12 of the die (see Figure 2 A) through the fingers, a wire rod insertion guide part 13 is formed at the entrance of the wire rod. Although the wire rod is easy to insert, when the wire rod is an ultra-fine wire, it has no stiffness, and it is difficult to insert the wire rod through the finger, through the wire rod insertion guide section, and into the wire rod gripping section.

Furthermore, machining grooves for gripping ultra-fine wire requires extremely high precision and is highly difficult. On the other hand, since the shape of the groove in the wire gripping part is slightly smaller in diameter than the wire, it is an absolute condition that when the wire is gripped, it does not slip even when pressed against the opposing wire. When the wire slips, various adjustments are made to grip the wire. but,
The time and skill required for this adjustment had become a major bottleneck in die production.

(Means for Solving the Problems) The present invention provides a die for a cold pressure welding machine that solves the above-mentioned problems. A groove wider than the wire gripping portion is provided in the wire rod gripping portion, and a plurality of grooves orthogonal to the grooves are formed in the wire rod gripping portion.

Fig. 2 is an explanatory diagram of a specific example of the die of the wire butt cold welding machine of the present invention, in which A is a top view, B is a sectional view taken along the line _X1 - _X1 of Fig. A, and C is a cross-sectional view of Fig. X ₂ − in diagram A
X ₂ arrow view, figure D is an enlarged view of the lower half of X ₃ in B.

As shown in the drawing, there is a wire rod gripping part 12 in the center of the die, and a wire rod insertion guide part 13 formed on both sides following the wire rod gripping part 12. Normally, the wire is inserted through the fingers into the wire rod gripping part using the insertion guide part 13 as a guide. 12 is inserted. However, the dice 11 of this invention
By providing a groove 15 that communicates with the wire gripping part 12 and has a wider width than the groove 15, the wire rod abutment part at the center of the die 11 is made easier to see from above, and the wire rod can be inserted more easily. As a result, when inserting the wire into the wire gripping part 12, instead of inserting it through the fingers as in the conventional case, open the fingers, place the wire from the upper part of the groove 15, and then insert the wire into the gripping part 12. Approximately 2 to 3 mm into the groove of
Complete by pushing and inserting. Therefore, even a stiff wire such as an ultra-fine wire can be easily inserted.

Further, as described above, the wire gripping portion 12 of the ultra-fine wire
The groove requires high-precision machining and also requires that the wire does not slip during pressure welding. However, in the present invention, as shown in FIG. A plurality of grooves 16 with a certain depth are cut in the direction to prevent the wire from slipping. This groove 16 is effective if it is formed using an electric pen after the die is hardened and heat treated.

(Effects of the Invention) As explained above, according to the die of the present invention, by providing grooves communicating with both sides of the wire gripping portion of the die, the wire rod abutting portion at the center of the die is easier to see than the upper part. Moreover, it becomes possible to easily insert the wire into the wire gripping portion without using fingers.

Furthermore, by cutting a plurality of grooves in the orthogonal direction to the grooves of the wire gripping portion, it is possible to prevent the wire from slipping and to grip it reliably, and adjustments can be made in a short time.

As described above, the die of the present invention is extremely effective in eliminating slippage during insertion and pressure welding of the wire, which has been a problem with conventional ultrafine wires.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a die portion of a cold pressure welding machine, and FIGS. 1A to 1D are explanatory diagrams of the movement of the die portion. Figure 2 is an explanatory diagram of the die of the present invention, where A is a top view, B is a cross-sectional view of X ₁ - X ₁ in Fig. A, and C is a view taken along arrows X ₂ - X ₂ of A , Figure D is an enlarged view of the lower half of X ₃ in Figure B. 11...Dice, 12...Wire rod gripping part, 13...
...Wire insertion guide section, 14...Flash storage section, 15...
...Wire rod insertion guide groove, 16... Orthogonal groove of wire rod gripping part.

Claims (1)

[Scope of utility model registration request] The die has a wire rod gripping portion in the center thereof, and a wire insertion guide groove wider than the wire rod gripping portion is provided on both sides following the wire rod gripping portion, and a plurality of grooves perpendicular to the wire rod gripping portion are formed in the wire rod gripping portion. A die for a cold welding machine for butting wire rods.