JPH05208U - Mouth wire for drawing process - Google Patents

Abstract

(57) [Summary] [Purpose] The tip of a hot-rolled wire rod is processed with a small amount of work. [Structure] A tip-end wire 2 having a diameter smaller than that of the hot-rolled wire 1 is frictionally welded to the tip of the hot-rolled wire 1 concentrically, and then a portion near the end of the hot-rolled wire 1 and a friction welding portion are formed by cutting. A tapered cone portion 4 is attached between the two. [Effect] Because of the friction welding, the hot-rolled wire rod 1 and the pre-attached wire rod 2 can be pressed together in a short time, and when the cone portion 4 is processed, only the corner portion and the flash 3 of the hot-rolled wire rod 1 are processed. Therefore, the tip of the hot-rolled wire rod 1 can be edged with a small amount of cutting.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention eliminates the complicated work and labor required for secondary machining such as wire drawing of a wire rod unwound from a wire coil, and improves the productivity for drawing work. The present invention relates to a wire rod with a mouth.

[0002]

[Prior Art]

 As is well known, when various metal materials are roll-formed into hot-rolled wire rods by continuous rolling equipment with many rolling roll stands, most of these wire rods, except for some, are drawn (pulled out). (Including), that is, secondary processing.

Such a secondary working process varies depending on the material of the raw material or its application, but a typical example thereof is, for example, hot rolled wire rod → heat treatment → pickling → coating → drawing → ( Heat treatment → pickling → coating → wire drawing →) product.

As is well known, such wire drawing is a process of reducing the cross-sectional area of a wire material by using a molding die in order to obtain a wire diameter, shape, etc. suitable for an end use. Prior to processing, the end of the hot-rolled wire is subjected to so-called mouth-piece processing to make it thin enough to pass through the forming die.

In performing the forming process, first, the hot-rolled wire is heat-treated, pickled and coated, and then conveyed to an end drawing machine called a forming machine, where it is processed. The hot-rolled wire rod is rolled into a coil shape after the completion of the rolling and forming, but the arc portion of the coiled wire rod is straightened.

If the wire is a thin wire or a wire having a relatively low strength, it can be corrected by human power, but if it is a thick wire or a high strength wire, it must be corrected by a straightening machine using hydraulic pressure. I won't.

In the wire rod whose end portion has been corrected to have a predetermined length in this manner, the coiled peripheral portion thereof is suspended in the air by a hoist or the like, and the linear end portion thereof is, for example, cold-pressed. It is processed with a mouth by rolling, peeling (cutting), swaging (forging pressure), etc.

However, such work is mainly performed manually, and not only the worker takes an excessive amount of work, but also the mouthpiece work time is longer than the wire drawing work time. In many cases, the results were unfavorable in terms of productivity and workability.

In order to solve such a problem, as disclosed in, for example, Japanese Patent Publication No. 60-28563 and Japanese Patent Publication No. 53-142961, there is a system in which a series of mouthpiece work is mechanized. .

First, in the former, the rolled wire rod is deflected from the center of the rolling line during the rolling line until the coil is wound after finishing rolling of the wire rod, and one end of the deflected rolled wire rod is on the rolling line. The mouth part is rolled by a roll. In the latter case, a mouthpiece processing machine is provided between the hot rolling mill and the winder to form a mouthpiece portion at the end of the rolled wire.

[0011]

[Problems to be solved by the device]

 The above-mentioned two conventional examples are both for the purpose of omitting the steps in the secondary processing manufacturer and reducing the burden of the worker's muscular work, but both are economical in view of the equipment cost. In addition to being disadvantageous, it is not always productive. Above all, the fact that there is no evidence that it has been put into practical use in any case is the above fact.

[0012] There is a strong demand for a die-cast wire rod that is subjected to die-casting at the rolling stage in order to omit the wire-drawing process and reduce the burden of muscle labor. It is not preferable to bear the burden.

Therefore, an object of the present invention is to provide a mouthpiece wire rod for drawing work that does not place a heavy burden on the primary working maker.

[0014]

[Means for Solving the Problems]

 The present invention has been made in view of the above circumstances. Therefore, the feature of the drawn wire rod for drawing processing according to the present invention is that a thinly worked hole is formed at the tip of the hot rolled wire rod. In a drawn wire rod for drawing, the mouthed portion is a pre-attached wire rod having a diameter smaller than that of the hot rolled wire rod friction-welded to the tip of the hot-rolled wire rod by a friction welding machine, and a cutting device. The hot rolled wire rod has a cone portion formed by cutting a peripheral edge portion of the end of the hot-rolled wire rod on the pressure welding side of the pre-rolled wire rod into a taper shape.

[0015]

[Action]

 According to the lead wire for drawing according to the present invention, since the heat input in friction welding is small, it is possible to press the pre-attached wire to this tip in a short time without annealing the hot rolled wire. Then, the step portion of the hot-rolled wire rod and the pre-attached wire rod and the flash bulging outward of the circumference of the wire pressure welding portion due to the pressure welding are cut into a taper shape by a cutting device and the cone portion is cut. Is formed, but the cutting amount is small.

[0016]

【Example】

 1a, 1b and 1c which are explanatory diagrams of the procedure for forming the tip of a hot rolled wire rod, FIG. 2 which is an explanatory diagram of strength of a pressure contact portion, and a graph diagram of a relationship between a drawing strength ratio and a wire diameter ratio. 3; FIG. 4 is an explanatory view of friction welding conditions; FIG. 5 is a sectional view of friction welding portions of the specimen under condition A; FIG. 6 is a sectional view of friction welding portions of the specimen under condition B; This will be described with reference to FIG. 7 which is a hardness distribution graph diagram of the sample material which is A and FIG. 8 which is a hardness distribution graph diagram of the sample material which is condition B.

First, as shown in FIG. 1 a, in the manufacturing line until the wire rod coils after hot rolling are bundled, the hot rolled wire rod 1 is placed at the radial center of the tip of the hot rolled wire rod 1. The diameter of the pre-attached wire rod 2 having a very small diameter is aligned, and pressure welding is performed by a friction welding machine (not shown) having a known configuration.

When the two wires 1 and 2 are pressure-welded to each other, as shown in FIG. 1b, the hot-rolled wire 1 and the pre-attached wire 2 bulge outward along the outer periphery of the pressure-welded portion. The so-called 3 will occur.

As described above, since the burrs 3 cannot be passed through the drawing die for wire drawing in a state where the burrs 3 are still generated, the cutting device (not shown) can be used to heat the burrs 3 together with the burrs 3 as shown in FIG. 1c. A taper-shaped taper is formed by cutting a corner portion around the outer periphery of the end portion of the rolled wire rod 1 into a taper shape, and the outer diameter of the rolled wire rod 1 becomes smaller from the hot rolled wire rod 1 side toward the pre-attached wire rod 2 side. And the inner part 4 is formed.

Since the heat input amount is small in the pressure welding of the pre-attached wire 2 to the tip of the hot-rolled wire 1, it is not necessary to anneal to improve the supercooled structure of the joint as in normal heating welding. Therefore, both wires 1 and 2 can be pressure-welded to each other in an extremely short time. By the way, the pre-attached wire rod 2 prepared in advance does not care about its steel type or wire diameter, but it is necessary that the pre-attached wire rod 2 has such a joining strength that the joining portion does not cut during the drawing process.

That is, as shown in FIG. 2, the diameter of the rolled wire 1 is D ₁ , the tensile strength is Ts ₁ , the hole diameter of the die d is D ₂ , the diameter of the tip wire 2 is D ₀ , and the tensile strength is Assuming that Ts ₀ , the area reduction rate are R, and the pulling force is P ₁ , the pulling force P ₁ is P ₁ = D ₁ ² · Ts ₁ · 2 · R (1-R) <D ₀ ² · Ts ₀ (equation )It can be expressed as. That is, since R = 1− (D ₂ / D ₁ ) ² and D ₀ <D ₂ , D ₂ ² = (1−R) D ₁ ^{2 From the} formula, D ₀ ² <(1−R) D ₁ ² is led, the expression is derived.

Next, by multiplying each of the terms in the above equation by Ts ₀ , D ₀ ² · Ts ₀ <(1-R) D ₁ ² · Ts ₀ (equation) is obtained, and D ₀ ^{2 on} the left side of the equation · the Ts ₀ substituting the left side of the ^{_{D 1 2 · Ts 1 · 2}} · R (1-R) of the ^{_{formula, D 1 2 · Ts 1 ·}} 2 · R (1-R) <(1-R) D 1 ² · Ts ₀ , and Ts ₀ > Ts ₁ · 2 · R (formula) is obtained.

However, since the practical value of R is R ≦ 0.35, D ₀ ≦ 0.65D ₁ (formula), Ts ₀ ≧ 0.7Ts ₁ (formula), D ₀ ² · Ts ₀ > 0. 3D of 46D ₁ ² · Ts ₁ (formula) is obtained. By the way, when the tensile strength ratio Ts ₀ / Ts ₁ = Y and the wire diameter ratio D ₀ / D ₁ = X are transformed into the above formula, X ≦ 0.65 (formula), Y ≧ 0.7 ( Expression), X ² · Y> 0.46 (Expression).

The above equation is shown in FIG. 3 with Y on the vertical axis and X on the horizontal axis. The region where the bonding strength can be satisfied is X ≦ 0.65 of the equation, The range is the shaded area sandwiched by X ² · Y> 0.46 in the formula, and it is possible to reliably perform drawing work under the conditions that fall within this range. The following is a summary of the friction welding test, tensile test and drawing test. First, the test materials are as shown in Table 1.

[0025]

[Table 1]

Twelve sets of test materials each of which is composed of the base material (corresponding to the hot-rolled wire) and the pre-applied material (corresponding to the pre-applied wire) shown in Table 1 are prepared (hereinafter referred to as condition A). At the same time, 6 sets of test materials each consisting of a base material (corresponding to hot-rolled wire) and a pre-attached material (corresponding to pre-attached wire) were created (hereinafter referred to as condition B), and these were rotated. The welding was performed by friction welding under the conditions shown in FIG. 4 of the friction welding condition explanatory diagram, in which the number and the pressure welding load are both plotted on the vertical axis and the elapsed time is plotted on the horizontal axis.

In FIG. 3, the rotation speed N is continuously reduced to t ₁ seconds and the rotation speed is reduced to 0, and the pressure contact load is increased simultaneously with the rotation of the rotation speed N, and the pressure contact load is maintained at P ₁ ton until t ₁ second. Then, the pressure contact load is further increased from t ₁ , the pressure contact load is maintained at P ₂ ton for t ₂ seconds, and then the pressure contact load is reduced to 0. The above-mentioned such friction welding conditions, immediate Chi rotational speed N, the time t _1, the time t _2, when indicated by specific numbers of each pressure load P ₁ and pressure load P ₂ becomes as shown in Table 2.

[0028]

[Table 2]

The cross-sectional shape of the friction-welded portion of the sample material that satisfies the condition A (area reduction ratio 59%) after friction-welded welding is as shown in FIG. 5, and only the outer periphery of the pre-applied material 2 is in the friction-welded portion. The condition 3 (area reduction ratio 23%) after friction welding is applied while the burrs 3 are generated. The cross-sectional shape of the friction welding portion of the test material is as shown in Fig. 6. At the friction welding portion, burrs 3 are formed on both the outer periphery of the base material 1 and the outer periphery of the pre-applied material 2.

Then, a tensile test was performed by sampling without performing annealing treatment on both of these test materials, and 33.8 tons (42 Kgf / mm ² ) and 33.9 for the test material of condition A. tons of (42Kgf / mm ^2), and in the test piece of condition B obtained tensile strength of 34.2 tons (43Kgf / mm ^2), yet none of the test material at fracture of the press-contact joint However, it was due to the breakage of the pre-attached material 2.

Next, from the relationship of the capability of a wire drawing machine (not shown), for the test material under condition B, the corners of the flash 3 and the base material 1 on the pressure welding side of the front material 2 were cut into a taper shape. To form the mouthpiece, and as a pretreatment, pickling and bonderite treatment, then φ32 mm → φ27. By performing the drawing process under the drawing condition of 4 mm (area reduction rate: 27%), it was possible to perform the drawing without breaking the pressure-welded joint.

By the way, as described above, since the hole diameter of the drawing die is 27.4 mm, the pre-applied material 2 was cut to 26 mm and subjected to the drawing test. Furthermore, for the test material under condition A and the test material under condition B, the height distribution along the longitudinal direction at the center in the radial direction (indicated by the ● mark and the solid line) and the middle between the radial center and the outer circumference Altitude distribution along the longitudinal direction (indicated by a cross and a broken line) was investigated.

The results of the test materials comprising the condition A were as shown in FIG. 7, it indicates that the pressure-joint section near the highest hardness (● in sign 429H _mv, the × mark 319H _mv) is also Article result of test materials become matter B is as shown in FIG. 8, the pressure contact junction vicinity highest hardness degree (● in sign 468H _mv, the × mark 498H _mv) shows that it is also deer Since no defects were observed in the microstructure of the pressure welded joints of each of these test materials, it can be said from this fact that the pressure welded joints of the test materials have sufficient strength necessary for drawing. .. Actually, these friction welding devices and cutting devices may be installed in the refining line of the rolling mill.

In this way, in addition to being able to perform pressure welding in less than 30 seconds, it is possible to form the mouthpiece portion by a short-time cutting operation, so that it is possible to form a mouthpiece wire rod for drawing work with an extremely small load. It can be provided to the next processing manufacturer.

[0035]

[Effect of the device]

 As described above in detail, according to the mouthpiece wire rod for drawing according to the present invention, since the heat input of friction welding is small, it is not necessary to anneal the hot-rolled wire rod and the pre-attached wire rod can be attached to this tip for a short time. The burrs that bulge outward from the circumference of the wire pressure welding part due to the step and the pressure contact between the hot rolled wire rod and the pre-attached wire rod can be cut into a taper shape by a cutting device. Although the conical portion is formed, the amount of cutting is small, so the burden on the primary machining maker can be reduced, and the omission of steps in the secondary machining maker and the operator It can be expected to have an extremely large number of effects on reducing the load of muscle labor and improving productivity.

[Brief description of drawings]

1A, 1B, 1C, 1C, 1C, 1D, 1E, 1C, 1C, 1D, 1E, 1C, 1D, 1E, and 1C are explanatory views of a procedure for forming a tip on a hot-rolled wire rod.

FIG. 2 is an explanatory view of strength of a pressure contact portion.

FIG. 3 is a graph showing a relationship between a drawing strength ratio and a wire diameter ratio.

FIG. 4 is an explanatory diagram of friction welding conditions.

FIG. 5 is a sectional view of a friction welding portion of a test material under condition A.

FIG. 6 is a sectional view of a friction welding portion of a test material under condition B.

FIG. 7 is a hardness distribution graph of the pressure-bonded joint of the test material under the condition A.

FIG. 8 is a hardness distribution graph of the pressure-bonded joint of the sample under the condition B.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Hot-rolled wire or base material 2 ... Pre-applied wire or pre-applied material 3 ... Burr 4 ... Corn part

Claims (1)

[Claims for utility model registration] [claim 1] In a mouthpiece wire rod for drawing, which has a thinly machined mouthpiece portion at the end of the hot-rolled wire rod, the mouthpiece portion is formed by a friction welding machine. A pre-attached wire rod having a diameter smaller than that of the hot-rolled wire rod frictionally welded to the tip of the hot-rolled wire rod,
A mouthpiece wire rod for drawing, comprising a cone portion formed by cutting a peripheral edge portion of a hot-rolled wire rod on a pressure welding side of a hot-rolled wire rod into a taper shape by a cutting device.