JPS63309319A - Diamond die and wire drawing method - Google Patents

Abstract

PURPOSE:To remarkably reduce the wear and abrasion of a die and to enable steady wire drawing for a long time by using a diamond die having a hexagonal die hole as a die for continuous wire drawing of a wire rod but for a die used in the last stage at least. CONSTITUTION:In a continuous wire drawing, wire rod is drawn with a diamond die having a hexagonal die hole on each die other than the final die at least. From the viewpoint of crystalline structure of diamond, surfaces having the strongest wear and abrasion resistance appear on a die hole having such a shape and dies remarkably excellent in wear and abrasion resistance can be obtained. Accordingly, the wear and abrasion is reduced remarkably and a large quantity of wire rod can be drawn steadily for a long time. In addition, the hole of a die used in the last stage of the wire drawing stage is preferred to be made circle so that the wire finished is formed in complete roundness.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a diamond die used for wire drawing and a wire drawing method using the die.

[Conventional technology and its problems]

The dies used for wire drawing are worn out during wire drawing, and the hole diameter gradually increases or becomes scratched. In continuous wire drawing, the degree of die wear varies, and as the amount of wire drawing increases, the area reduction rate will differ from the originally set rate. As a result, if the slip ratio changes significantly, negative slip occurs, causing problems such as wire breakage. As a countermeasure to this problem, methods have been used in which the dies are replaced periodically, or the state of wear of the dies is checked and the dies are replaced. Another method was to check the outer diameter of the finished wire and replace the die.

However, if the dice are replaced regularly, the dice may be replaced more than necessary, which increases the cost of the dice. In addition, when replacing the die after checking the wear condition of the die, the area reduction rate changes significantly due to the delay in replacement, which may cause wire breakage.

When examining the wear condition of the die from the finished wire, it takes time and effort, and the delay in replacing the die may cause wire breakage. In particular, in the case of ultra-fine wires of 50-φ or less, it is difficult to even confirm whether the die is worn out or not. There were many other problems.

[Problem that the invention seeks to solve]

As a result of studying the above-mentioned problems, the present invention focused on the fact that diamond dies change their shape due to wear, but once they reach the new shape, the shape is maintained and wear does not progress. Furthermore, by using this die for wire drawing, we have developed a wire drawing method that significantly reduces problems such as die replacement and wire breakage.

[Means and effects for solving the problems] The first invention is a diamond die characterized in that the die hole is hexagonal. A second invention provides a wire drawing method characterized in that the wire is drawn using a diamond die having a hexagonal die hole. That is, in the present invention, as a result of wire drawing experiments using various diamond dies, it was found that the diamond dies take the shape shown in FIG. 1 when the wire is drawn and worn. That is, the shapes can be roughly divided into three types: (a) hexagonal, (ra) quadrilateral, and (C) rhombus. This is due to the diamond's crystal structure, and when it takes on these shapes, the most wear-resistant side of the diamond comes out, and once it wears down to this shape, it becomes stable and does not wear out. . Therefore, among these three shapes, a diamond die having the shape (a), which is close to a circle and a hexagon, was prepared and drawn, and as a result, a die having extremely excellent wear resistance was obtained.

To produce a diamond having the shape of the present invention, an ordinary circular die may be formed by polishing, or it may be formed into a hexagonal die from the beginning. Further, when wire drawing is performed using this hexagonal diamond die, the hexagonal diamond die of the present invention is used for at least the dies excluding the final die. The reason for this is that if hexagonal diamond dies are used up to the final die, the finished wire will not be a perfect circle. In other words, in the wire drawing method of the present invention, die wear is significantly reduced by using a hexagonal diamond die, which has die holes with less wear in the dies except for the final die, and therefore it is possible to draw a large amount of wire material into long lengths. The wire can be drawn stably for a long period of time.

In the diamond die of the present invention, the die hole does not necessarily have to be a regular hexagon, but may be substantially hexagonal or have a rectangular shape due to distortion of the crystal structure of the diamond.

〔Example〕

An embodiment of the present invention will be described below.

Diameter 0.90aaaφ as shown in Figures 2 and 3
of annealed copper wire (tough pitch copper) (1) with 12 dice (2
) was drawn to a diameter of 0.30ia. Diamond dies with hexagonal die holes were used for the 10th dies from the entrance side of the wire, and circular dies were used for the 11th and final dies. With this dice arrangement, so
When wire drawing of OOKG was carried out, the hexagonal diamond die showed almost no wear and there was no change in area reduction rate. For comparison, 5000 kg of tough pitch copper wire with a diameter of 0.90 mφ was drawn to an end diameter of 0.30 mm using 12 dies, all of which were ordinary circular diamond dies, using the above apparatus. In this case, the die hole shape was worn to an elliptical, square, or hexagonal shape, and the area reduction rate also changed significantly.

(Effects) As explained above, the die of the present invention hardly wears out, so the life of the die is improved.

In addition, in the wire drawing process, the number of die changes is reduced, and since there is no change in area reduction rate, there is no vibration of the wire, and problems such as wire breakage are reduced. It is something to do.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the shape of die wear, FIG. 2 is a side view showing an embodiment of the present invention, and FIG. 3 is a plan view of FIG. 2. 1...Wire rod, 2...Dice, 3...Capstan.

Claims (2)

[Claims] (1) A diamond die characterized by a hexagonal die hole. (2) A wire drawing method characterized in that, when continuously drawing a wire, diamond dies having hexagonal die holes are used in at least the other dies except the final die.