JPH0654407U - Wire drawing dies - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a die which is excellent in wear resistance, has a long life, is low in cost, and can obtain a product having excellent surface properties. [Structure] In a wire drawing die including a nib having an approach portion, a bearing portion, and a relief portion, and a case, the nib is formed by stacking a plurality of rings to form a wire drawing die.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a drawing die used for drawing a metal wire.

[0002]

[Prior art]

 Conventionally, for drawing a metal wire rod, as shown in FIG. 2, a wire drawing die composed of a nib 12 in which an approach portion 13, a bare ring portion 14 and a relief portion 15 are integrated and a steel case 11 is used. Is generally known. As the material of the nibs, steel, cemented carbide and diamond are used to withstand pulling pressure and frictional force. Also, in recent years, an example of applying ceramics to nibs has been reported. Among these, cemented carbides, which have excellent wear resistance and are relatively inexpensive compared to diamond and the like, are generally widely used.

[0003]

[Problems to be solved by the device]

 By the way, it is the approach portion 13 that has a reduction angle and performs drawing processing and the bearing portion 14 that is finished to a target size that the wire mainly contacts during the drawing processing. In particular, the approach part 13 is a part where the wire to be drawn first comes into contact, and is also a part to which the maximum drawing pressure is applied. If drawing is performed using a die with cracks, it will cause defects such as scratches on the wire. Therefore, the die with cracks was discarded and replaced with a new die.

Further, when the bearing portion 14 is worn, the inner diameter of the die expands and the wire cannot be drawn to a desired wire diameter. Therefore, the conventional die had to be replaced with a new die when worn. The worn dies were then re-used by polishing them to remove the wear on the bearings and increasing the bearing dimensions.

As described above, in the conventional die, since the nibs are of the integral type, the entire die must be replaced due to the loss of a part of the approach portion 13 or the bearing portion 14, and the die life is shortened. Was short. By the way, the cemented carbide used for nibs is less expensive than diamond, but is more expensive than ordinary steel. Therefore, the conventional method of replacing the entire die due to a partial loss of the nib was very expensive to maintain.

Further, although cemented carbide is excellent in strength, its lubricity at the time of drawing is inferior to that of ceramics and diamond, and if the supply of the lubricant is cut off, the approach part 13 and the bearing part 14 will be damaged. It had the drawbacks of seizure, scratches on the die and wire, and deterioration of the surface properties of the wire.

The present invention has been made in order to solve the above problems, and it is an object of the present invention to provide a die capable of obtaining a product having excellent wear resistance, long life, low cost, and excellent surface properties. To aim.

[0008]

[Means for Solving the Problems]

 As a result of earnest studies to investigate the cause of the above problems, the present inventors have found that the cause is the shape of the nib. That is, the inner peripheral wall of the above-mentioned conventional nib has a smooth outer shape in which the approach portion and the bearing portion are integrated, and the wire rod continuously contacts the inner peripheral wall without being cut off. Therefore, the amount of lubricant brought in is insufficient. In addition, since the material of the nib is cemented carbide and the wire is steel, seizure occurs between the two due to metal-to-metal contact, which can scratch the die and wire and deteriorate the surface properties of the wire. Becomes

[0009]

[Action]

 Based on the above findings, the present inventors have come to the view that it is best to achieve the above object by making the shape of the nib into a specific shape, and have completed the present invention. That is, the wire drawing die of the present invention is a die including a nib having an approach portion, a bearing portion, and a relief portion and a case. The nib is formed by stacking a plurality of rings.

In the above structure, the rings to be stacked may have a shape in which the inner peripheral wall has a trapezoidal shape, a polygonal shape, or the like, but a retaining portion for the lubricant is formed on the inner peripheral wall between adjacent rings. It is preferable that the shape is as described above. More preferably, the above-mentioned shape is a substantially arc shape. The roughly arcuate shape is not limited to an accurate arcuate shape, and includes, for example, a shape in which the corner R is chamfered.

[0012] In the above-mentioned structure, during drawing, wear resistant material such as cemented carbide or diamond having excellent strength is used only for the ring where the wire actually contacts, and other parts are made of other materials. It is possible to configure the die by using the material.

[0012]

[Action]

 A recess is formed in the inner peripheral wall portion between the adjacent rings. Since the concave portions serve as retention points for the lubricant and the lubricant can be easily brought in, seizure can be prevented and a product having excellent surface properties can be obtained. In addition, it is easy to replace the ring in cracked and worn parts, and the other part can be reused, which can extend the die life and reduce the maintenance cost. .

[0013]

【Example】

 An embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a vertical cross-sectional view of a die of the present invention, in which 1 is a case, 2 to 6 are rings, and 7 are screws for fixing the rings 2 to 6. Reference numeral 1 denotes a steel case having an outer diameter dimension A = 70 mm, an inner diameter dimension B = 40 mm and a thickness dimension C = 40 mm, in which rings 2 to 6 having a thickness of 4 mm and an outer diameter of 40 mm are stacked and fixed with screws 7.

By the way, among the rings 2 to 6, the rings 2, 3 and 4 correspond to the approach portion, the ring 5 corresponds to the bearing portion, the ring 6 corresponds to the relief portion, and the rings 4 and 5 are made of cemented carbide. S45C was used for 3 and 6. The inner peripheral wall shape and the inner diameter of each of the rings 2 to 6 are such that the rings 2, 3 and 4 are substantially arcuate inner wall, and the inner diameters of the rings 2 and 5.9 are 5.9 mm and 5. 6 mm, the ring 4 is 5.3 mm, and the inner peripheral wall of the ring 5 is substantially perpendicular to both bottom surfaces of the ring and has a corner portion with an R, the inner diameter is 5.0 mm, and the ring 6 has a substantially inner wall. The shape was circular and the inner diameter was 5.3 mm.

Next, the results of comparing the die life and the life state will be described by using a die of the present invention and a conventional nib-integrated die made of cemented carbide to draw a wire. <Conditions of the wire drawing> test material: hard steel wire 80C (TS135kg / mm ² class) drawing machine: Tankama drawing machine drawing speed: 200 meters / min lubrication: dry lubricant used working ratio: outer diameter 5. 5φ → 5.0φmm (area reduction ≈17.4%) Table 1 shows the results of the drawing of the wire rod under the above conditions.

[0016]

[Table 1]

In Table 1, the life is represented by the weight of the wire rod that has been drawn to the extent that it is necessary to correct the inner peripheral wall surface of the die drawing hole. As can be seen from Table 1, the die of the present invention has a life of about 1.5 times that of the conventional die, and seizure does not occur on the inner peripheral wall surface of the drawing hole of the die at the end of its life. .

[0018]

[Effect of device]

 In the present invention, since the nib is constructed by stacking a plurality of rings, it is possible to use the wear-resistant material only for the rings that are in contact with the wire, and the other rings can be made of inexpensive steel material. In addition, even if the die wears, it is only necessary to replace the ring in that part, and the other parts can be reused, so the maintenance cost is reduced by about 30% compared to the conventional product. I was able to. Furthermore, since the lubricant is brought in easily, there is little damage to the die due to baking, and the die life can be improved by about 50% compared to the conventional product, and it is also possible to obtain a product with excellent surface properties. Produce the effect.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a die according to an embodiment of the present invention.

FIG. 2 is a vertical sectional view showing a conventional die.

[Explanation of symbols]

 1, 11 Case 2, 3, 4, 5, 6 Ring 7 Screw 8 Die 9 Wire 12 Nib 13 Approach part 14 Bearing part 15 Relief part

Claims (2)

[Scope of utility model registration request] 1. A drawing die comprising a nib having an approach portion, a bearing portion and a relief portion and a case, wherein the nib is formed by stacking a plurality of rings. 2. The wire drawing die according to claim 1, wherein the outer peripheral shape of the inner peripheral wall of the stacked rings is substantially an arc shape.