JPH10225742A - Method for forging wire rod and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enlarge the elongation of a wire rod, to fully straighten material having difficult-to-working, etc., and to prevent the bending in a process for heating to necessary temp. to forging by heating the wire rod to a specific temp. or higher after uncoiling and straightening or during uncoiling and thereafter, straightening again. SOLUTION: The coiled wire rod hung down with rolling-contact roll 1 is carried into interval between the rolling-contact roll 1 and a pinch roll 3 and pinched with both rolls. The rolling-contact roll 1 and straightening rolls 4a are linked and rotated, and the wire rod 2 is passed through to the outlet side of the pinch rolls 4c arranged at the outlet side of the straightening device 4. After straightening to a large curving radius with the straightening device 4, the wire rod 2 is heated to >=400 deg.C with a heating device 5. After heating, the wire rod is straightened to the linear state with a straightening device 7 and thereafter, the wire rod 2 is heated to the necessary temp. to the forging with a heating device 6 and fed to a hot forging device 9 and shorn with a shear 9c and pressed with the forging part 9e.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire forging method and apparatus, and more particularly to a forging method suitable for forging a wire having low ductility at normal temperature and a method suitable for carrying out the forging method. It concerns the device.

[0002]

2. Description of the Related Art Conventionally, there has been proposed a method and an apparatus for continuously supplying a coil-shaped material (hereinafter simply referred to as a "wire") by winding a wire or a steel bar and performing hot forging. ,
Regarding the mechanism and control method, see, for example,
No. 38632, JP-A-61-199542, Tokuhei 3
No.-14535, No.3-14536, No.3-
Several improvements such as 14537 and JP-B-7-41345 have been proposed.

[0003] For example, a general carbon steel wire such as S45C can be forged without any trouble by using such a method or apparatus.

[0004]

However, in the case of a wire having low ductility at room temperature, such as a bearing steel having a ductility of 5% or less, sufficient bending and unbending cannot be performed at room temperature. It must be sent in the form of the radius of curvature as it is. In addition, since the residual stress due to the correction is also generated, a problem occurs in that a bend occurs in a heating device for heating to a temperature required for forging, and the material cannot pass through the heating device. In addition, since hot forging is intermittent, feeding into a heating device or the like is repeated starting and stopping, so the wire will be fed while shaking, especially in the case of thick wire. Occurs. Therefore, when forging such a wire, a coil-shaped wire cannot be used, and there has been no other choice but to use a straight wire in view of a decrease in yield and damage to a mold.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and provides a method for performing forging without any trouble using a coil-shaped wire even if the wire has low ductility at room temperature. It is intended to provide an apparatus for performing the method.

[0006]

In order to achieve the above object, according to the present invention, the wire is heated to 400 ° C. or more after unwinding and straightening or during unwinding, and then straightened again. I have. And by doing in this way, the unwound and straightened wire, the tensile strength of the unwound wire is reduced, the ductility is increased, the difficult-to-work material can be completely straightened, and the residual stress is also reduced. Bending in the step of heating to the temperature required for the subsequent forging can be prevented.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first wire forging device according to the present invention comprises a wire coil rewinding means, a conveying means for feeding a rewinded wire, and a straightening device for straightening the rewinded wire into a substantially straight line. Means, a heating means for heating the wire corrected by the straightening means to 400 ° C. or more, a second straightening means for correcting the wire heated by the heating means again to improve the linearity, and Means for heating the wire straightened by the straightening means and having improved linearity to a temperature required for forging, means for shearing or cutting the wire heated by the heating means to a predetermined length, and means for shearing or cutting the wire. The means for forging the wire material that has been sheared or cut in this way are sequentially arranged in series.

In the first wire rod forging device according to the present invention, the coiled wire is rewound using the wire coil rewinding means and straightened using the straightening means while being fed by the conveying means. And then heating means 40
After heating to 0 ° C. or higher, the wire heated by the second straightening means is straightened again to improve linearity, and then heated to a temperature required for forging by the heating means, and then sheared or cut by a predetermined means. The first wire forging method according to the present invention is to shear or cut to a length and forge by a forging means.

According to the first method of forging a wire rod according to the present invention, it is possible to completely correct a difficult-to-work material having low ductility at room temperature, which has been unwound and straightened, and has a low residual stress. It is possible to prevent bending in the process of lowering and heating to a temperature required for the subsequent forging.

Further, a second wire forging apparatus according to the present invention comprises a wire coil rewinding means, and a heating device for heating the coiled wire to 400 ° C. or more during rewinding of the wire by the rewinding means. Means and 400 ° C by this heating means
Conveying means for feeding the wire material heated and rewound as described above,
Straightening means for straightening the unwound wire, heating the wire corrected by the straightening means to a temperature required for forging, and shearing the wire heated by the heating means to a predetermined length. Or means for cutting, and means for forging the wire rod sheared or cut by this shearing or cutting means, are sequentially arranged in series, at this time,
As the heating means for heating to 400 ° C. or higher, a direct current heating device including a high-frequency heating device having a horseshoe-shaped or oval coil shape, a pinch roller for feeding power, and a pinch roller for returning current to the power supply device is preferable. .

In the second wire forging apparatus according to the present invention, the coil-shaped wire is heated to 400 ° C. or more by the heating means while the coil-shaped wire is unwound using the wire coil unwinding means. Then, the heated wire rod is straightened by using the straightening means while being sent by the conveying means, and then heated to a temperature required for forging by using the heating means, and then the shearing or cutting means. The second method for forging a wire rod according to the present invention is to perform shearing or cutting to a predetermined length by using the forging means.

According to the second wire forging method according to the present invention, the tensile strength of the unwound wire is reduced and the ductility is increased.
The present invention can be performed more easily than the invention described above, and can prevent bending in a step of heating to a temperature required for the subsequent forging. At this time, the radius of curvature of the unwound wire is about the diameter (1 to 1.5 m) of the normally wound coil and must be intermittently fed, so that the wire is fed while shaking. However, the use of a high-frequency heating device having a horseshoe-shaped or elliptical coil shape can sufficiently cope with the problem. In addition, by using a direct current heating device including a pinch roller for feeding power and a pinch roller for returning current to the power supply device, the coil can be continuously fed, and the coil is prevented from swinging during feeding. Can be.

[0013] The third wire forging apparatus according to the present invention comprises a wire coil rewinding means, a conveying means for feeding the rewinded wire, and a rewinding wire having a radius of curvature which does not become infinite. Straightening means for increasing, a heating means for heating the wire whose radius of curvature has been increased by the straightening means to 400 ° C. or higher, and a second straightening means for straightening the wire heated by the heating means so as to be linear. And this second
A second heating means for heating the wire made linear by the straightening means to a temperature required for forging, and a means for shearing or cutting the wire heated by the second heating and heating means to a predetermined length; Means for forging the wire rod sheared or cut by the shearing or cutting means are sequentially arranged in series. At this time, the means for heating to 400 ° C. or higher includes a horseshoe-shaped or oval coil shape. And a direct current heating device comprising a pinch roller for feeding power and a pinch roller for returning current to the power supply device.

In the third wire forging apparatus according to the present invention, the coil-shaped wire is rewound using the wire coil unwinding means, and the radius of curvature of the wire is reduced using the straightening means while being fed by the conveying means. After the wire is heated to 400 ° C. or higher by a heating unit, the wire heated by the second straightening unit is straightened by a straightening process, and then the second straightening process is performed. The third wire forging method according to the present invention is that after heating to a temperature required for forging by the heating means, the wire is sheared or cut to a predetermined length by a shearing or cutting means and forged by a forging means.

According to the third method of forging a wire according to the present invention, the wire to be rewound is not straightened immediately, but is once corrected to a large radius of curvature, so that the ductility at room temperature is less. Even if the difficult-to-work material is rewound without heating, it does not break or crack on the surface, and also reduces the residual stress and prevents bending in the process of heating to the temperature required for subsequent forging. .

In the present invention, the wire is heated to 400 ° C. before straightening.
The reason for the above heating is to avoid the brittle region of the wire existing in a temperature range of less than 400 ° C. and to reduce the tensile strength of the wire and increase the ductility at such a high temperature.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A wire forging apparatus according to the present invention is shown in FIGS.
The present invention is described based on the embodiment shown in FIG. 8 and extends to a wire rod forging method according to the present invention using these forging devices. FIG. 1 is a side view showing a schematic configuration of a first wire forging apparatus according to the present invention, FIG. 2 is an explanatory view when a wire is straightened and deformed, (a) is a material passing through a roller, and (b) is FIG. 3 is an explanatory view of a repeated bending deformation process, FIG. 3 is a side view of a main part showing a schematic configuration of another embodiment of the first wire forging apparatus according to the present invention, and FIG. 4 is forging a second wire according to the present invention. FIG. 5 is an explanatory view of the high-frequency heating coil in FIG.
(A) is a horseshoe shape, (b) is an oval shape, FIG. 6 is a side view of a main part showing a schematic configuration of another embodiment of the second wire forging device according to the present invention, and FIG. FIG. 8A is a side view showing a schematic configuration of a third wire forging device, FIG. 8A is a side view of a rewinding portion in the second wire forging device according to the present invention,
(B) is a front view of the figure (a).

[Embodiment 1] FIG. 1 is a side elevational view showing a schematic structure of a first wire forging apparatus according to the present invention (however, a hot forging apparatus 9 is a plan view). It should be noted that the device configuration may be such that this drawing is a plane surface or a side surface. In FIG. 1, reference numeral 1 denotes a rolling contact roll for suspending a coiled wire 2 conveyed by a crane or the like.
The coiled wire rod 2 suspended at its tip is provided with a pinch roll 3 whose tip is disposed so as to be able to move toward and away from the rolling contact roll 1 by the reciprocating movement of a rod of a cylinder 3a. And pinched by the transfer roll 1 and the pinch roll 3. Although one transfer roller 1 is shown in FIG. 1, a counterpart portion of the pinch roll 3 in the transfer roller 1 and a suspended portion of the coiled wire 2 are usually independent.

Reference numeral 4 denotes a straightening device arranged downstream of the pinch roll 3, and a plurality of bending straightening rolls 4a and 4b are arranged in a staggered manner in the vertical direction. The number of the bending straightening rolls 4a and 4b, the size of the rolls, the roll pitch, and the like are appropriately set according to the material and thickness of the wire 2. Among these, the bending straightening roll 4b, which is arranged above the line and moves up and down by the reciprocating movement of the rod of the cylinder 4b, can be fixed at an arbitrary position. For optimal straightening, FIG. As shown in (a), the position is set so that the wire 2 is bent or bent back, and the leading end of the wire 2 is pressed by the pinch roll 3 and then placed below the rolling contact roll 1 and the line. Bending straightening roll 4
By rotating a in conjunction with each other, the bending straightening rolls 4a and 4b in which the wire rods 2 are arranged in a staggered manner in the vertical direction.
, While passing through to the exit side of the pinch roll 4c arranged on the exit side of the straightening device 4, and straightens it almost linearly. In addition, the pinch roll 4c normally raises the upper roll before the front end of the wire 2 passes, and lowers it after passing.

Reference numerals 5 and 6 denote heating devices interposed between the straightening device 4 and a hot forging device 9 described later. The conventional heating device 6, that is, the hot forging device 9 in the embodiment of FIG. Although it is arranged immediately before and is usually divided into about three high-frequency coils, in this embodiment, since another heating device 5 (high-frequency coils 5a and 5b) is installed upstream thereof, the heating device is Reference numeral 6 denotes a coil divided into two high-frequency coils 6a and 6b.

The upstream heating device 5 of the heating device has a heating amount corresponding to one high-frequency coil of the conventional heating device (downstream heating device 6) and heating devices 5 and 6. A capacity is required in consideration of the heat loss of the roll in the second straightening device 7 disposed therebetween. In this embodiment, the high-frequency coil 5a is divided into two high-frequency coils 5a and 5b. Of course, each of the high-frequency coils 5a, 5b and 6a, 6b may be integrated one by one or one of them.
Conversely, further division is possible.

Note that support rolls 8a and 8b for guiding the leading end of the wire 2 sent to the high-frequency coils 5b and 6b are arranged as necessary between the high-frequency coils 5a and 5b and between the high-frequency coils 6a and 6b. Is done. The second straightening device 7 is structurally similar to the straightening device 4 and is used in the same manner. However, the number of rolls and the like are appropriately set as appropriate.

As described above, with the end of the wire rod 2 having passed to the exit side of the pinch roll 4c, the rolling roll 1 and the bending straightening roll 4a disposed below the line are rotated in conjunction with each other. If the tip of the wire 2 is a heating device 5, the second
Hot forging device 9 which passes through the straightening device 7 and the heating device 6
To reach the entrance.

The hot forging device 9 includes a feed roll 9a, a clamp 9b, a shear 9c, and a stopper 9d.
A forged part 9e composed of a die and a press is disposed. When the wire 2 is fed until its tip reaches the surface of the stopper 9d, the feeding is stopped. After stopping, the clamp 9b is moved to the wire 2 side to clamp the wire 2, and then the shear 9c is moved to the wire 2 side and sheared to a length required for forging. Next, the sheared wire 2 is forged 9e.
And press working here. During this press working, the clamp 9b and the shear 9c are retracted to their original positions, preparing for the next operation.

The wire 2 is fed by a pinch roll 4c, and the control is performed by the method described in, for example, Japanese Patent Publication No. 7-41345 or Japanese Patent Publication No. 3-14535-7. In addition, the end of the pinch roll 4
If the feed of the wire 2 is switched to the feed roll 9a of the hot forging device 9 immediately before passing through the line c, waste is reduced.

The present inventors have confirmed the effect of the present invention by using a bearing steel having a diameter of 30 mm, and found that the tip of the conventional high-frequency coil triple system was bent by about 15 mm and was caught by the high-frequency coil, so that the heating device was not used. Although it could not pass, in the method of the present invention using the device of the present invention shown in FIG.
The amount of heating substantially equivalent to the first heating amount of the high-frequency coil in the conventional heating device 6 is determined by the high-frequency coils 5 a
And the high-frequency coils 5a and 5b
After being heated to at least 00 ° C., the wire was straightened so that the wire 2 could pass through it. However, depending on the type of steel, the bend is further large, and the device shown in FIG. 1 may not be able to pass through the high-frequency coils 5a and 5b of the first heating device 5, but in such a case, as shown in FIG. If the straightening device 7a is further provided between the high-frequency coils 5a and 5b of the heating device 5, it can be passed without any problem.
The heating temperature of the wire 2 is 800 ° C. at the outlet surface temperature of the heating device 5 and 1200 ° C. at the outlet surface temperature of the heating device 6.
It was forged smoothly.

[Embodiment 2] FIG. 4 is a side view of a main part showing a schematic configuration of a second wire forging apparatus according to the present invention.
2 shows a portion different from the first wire forging device according to the present invention shown in FIG.

In FIG. 4, reference numerals 10a to 10c denote pinch rolls disposed at appropriate positions on the outer periphery of the coil-shaped wire 2 hung on the transfer roller 1, and high-frequency waves are provided between the pinch rolls 10a to 10c. Coil 11a, 11b
Is interposed.

In such a configuration, the leading end of the coiled wire 2 suspended from the transfer roller 1 is carried between the two rolls constituting the first pinch roll 10a. Pinched. The wire 2 is sent by the pinch roll 10a, passes through the high-frequency coil 11a, the pinch roll 10b, the high-frequency coil 11b, and the pinch roll 10c, and is heated to 400 ° C. or higher.
After passing between the transfer roll 1 and the pinch roll 3, the straightening device 4
Where it is sufficiently corrected in the same manner as a wire having high ductility at room temperature, and is formed into a linear shape. Then, after the straightening, the sheet is heated to a temperature required for forging by the heating device 6, and then sent to the hot forging device 9, where required press working is performed.

Incidentally, the coil diameter of the coiled wire rod 2 suspended on the transfer roller 1 generally ranges from 1 to 1.
Since the length of the pinch rolls is 5 m, the stroke of the cylinder is determined so that any pinch rolls 10a to 10c can be used within this diameter range. Similarly, the high-frequency coils 11a and 11b are also formed into a horseshoe shape as shown in FIG. 5A or an oblong shape as shown in FIG. It is possible to cope with the fluctuation of the coil diameter in a small installation space without lowering the thermal efficiency.

Further, as shown in FIG.
Instead of 1a, 11b, one of the two rolls constituting the pinch rolls 10a to 10c is one of the rolls 10aa to 10aa.
10ca may be a pinch roll for feeding power, and the remaining one of the rolls 10ab to 10cb may employ a direct current heating device that is a pinch roll for returning current to a power supply device.

[Embodiment 3] FIG. 7 is a side view of a main part showing a schematic configuration of a third wire forging apparatus according to the present invention (a hot forging apparatus 9 is a plan view). The structure of a portion different from the first wire forging device according to the present invention shown in FIG.

In the second wire forging apparatus according to the present invention shown in FIG. 4, a high-frequency wave is applied between pinch rolls 10a to 10c installed at appropriate positions on the outer periphery of a wire 2 hung on a rolling contact roll 1. Since the coils 11a and 11b are provided,
Burn-in coil (pay-off reel) 12 and rolling roller 1
As shown in FIG. 8 (b), it was necessary to increase the distance L between the wire 2 and the wire 2 to be hung.

Therefore, in the third wire forging apparatus according to the present invention shown in FIG. 7, the pinch rolls 10a to 10c are provided.
No high-frequency coils 11a and 11b are interposed between
The straightening device 4 does not straighten the straight line immediately, but once straightens the radius of curvature as large as possible without becoming infinite. The arrangement, number, rotation state, and the like of the bending straightening rolls 4a in the straightening device 4 are the same as in the case of the first wire forging device according to the present invention described above.

After straightening to a large radius of curvature by the straightening device 4 as described above, the wire 2 is heated to 400 ° C. or more by the heating device 5. Then, after heating, it is straightened by the second straightening device 7, heated to a temperature required for forging by the heating device 6, and sent to the hot forging device 9. The wire 2 sent to the hot forging device 9 is sheared by a shear 9c to a length necessary for forging, and is pressed in a forging portion 9e.

In the above-described third wire forging apparatus according to the present invention, the high-frequency coils 5a,
5b is the same as the high-frequency coils 11a and 11b in the second wire forging device according to the present invention described above.
As shown in FIG. 5A, a horseshoe shape as shown in FIG. 5A or an elliptical shape as shown in FIG. 5B is used. Further, as shown in FIG. If one of the rolls is a pinch roll for feeding power and the other roll is a pinch roll for returning current to the power supply, a direct current heating device is adopted, so that the coil diameter can be reduced. And the handling becomes easy.

The present inventors have confirmed the effect of the present invention by applying it to a material having a high breaking strength among bearing steels having a diameter of 30 mm and thus having a high yield stress. In the case of a material having an elongation of the plastic zone at room temperature of 2.5%, in the method of the present invention using the first device according to the present invention, the wire is not substantially linear at the outlet of the straightening device 4, and the high-frequency coil 5a has a wire rod. It's just about the tip of 2
The robot was caught by the high-frequency coil 5a and could not move forward. Therefore, if the amount of reduction of the bending straightening roll 4a is further adjusted so as to be linear at the outlet of the straightening device 4, the wire 2 is broken.

On the other hand, in the method of the present invention using the third device according to the present invention, although a large bend remains at the exit of the pinch roll 4c, it can pass through the horseshoe-shaped heating device 5, and this heating device 5 By heating to 600 ° C,
The strength is also reduced and the elongation of the plastic zone will be allowed,
The heating device 6 can pass through the second straightening device 7 and thereafter without any trouble.
By setting the surface temperature on the exit side of the sample to 1200 ° C., forging could be performed smoothly.

[0039]

As described above, according to the present invention,
Even a wire having low ductility at room temperature can be easily corrected, and can be prevented from bending in a subsequent step of heating to a temperature required for forging, so that a coiled wire can be used. Therefore, there is no joint as in the case where a linear wire is used, and it is possible to prevent damage to the mold and deterioration in quality caused when pressing the joint. This effect is more remarkable in the second and third aspects of the present invention. In the third aspect of the present invention, the interval between the bar-in coil (pay-off reel) and the wire suspended from the rolling contact roll is
There is no need to take large.

[Brief description of the drawings]

FIG. 1 is a side view showing a schematic configuration of a first wire forging apparatus according to the present invention.

FIGS. 2A and 2B are explanatory diagrams when a wire is deformed and corrected. FIG. 2A is a diagram illustrating a material passing through a roller, and FIG.

FIG. 3 is a side view showing a main part of a schematic configuration of another embodiment of the first wire forging apparatus according to the present invention.

FIG. 4 is a main part side view showing a schematic configuration of a second wire forging apparatus according to the present invention.

FIG. 5 is an explanatory diagram of the high-frequency heating coil in FIG. 4;
(A) shows a horseshoe shape, and (b) shows an oval shape.

FIG. 6 is a main part side view showing a schematic configuration of another embodiment of the second wire forging apparatus according to the present invention.

FIG. 7 is a side view showing a schematic configuration of a third wire forging apparatus according to the present invention.

8A is a side view of a rewinding part in the second wire forging apparatus according to the present invention, and FIG. 8B is a front view of FIG.

[Explanation of symbols]

 Reference Signs List 2 wire rod 3 pinch roll 4 straightening device 4c pinch roll 5 heating device 6 heating device 7 second straightening device 9 hot forging device 10aa roll 10ba roll 10ca roll 11a high frequency coil 11b high frequency coil

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ Identification code FI B21K 27/04 B21K 27/04 H05B 3/00 340 H05B 3/00 340 6/10 351 6/10 351 6/36 6/36 (72) Inventor Takai Hasegawa 4-5-33 Kitahama, Chuo-ku, Osaka City, Osaka Prefecture Inside Sumitomo Metal Industries, Ltd. (72) Inventor Masanobu Uemura 4-5-33, Kitahama, Chuo-ku, Osaka City, Osaka Sumitomo Metal Industries (72) Inventor Hideki Higuchi 4-5-33 Kitahama, Chuo-ku, Osaka City, Osaka Prefecture Inside Sumitomo Metal Industries, Ltd. (72) Inventor Tadashi Sawada 1 Konomi-cho, Kokurakita-ku, Kitakyushu-shi, Fukuoka Sumitomo Metal Kokura Steel Works, Ltd.

Claims (8)

[Claims] 1. A method in which a coil-shaped wire is unwound, straightened while being fed, heated to a temperature required for forging, and then sheared or cut to a predetermined length and forged. And heating the straightened wire to 400 ° C. or higher and re-straightening the wire before heating it to a temperature required for forging. 2. A method in which a coil-shaped wire is straightened while being rewound and fed, heated to a temperature required for forging, and then sheared or cut to a predetermined length and forged. A forging method for a wire, wherein the coil-shaped wire is heated to 400 ° C. or higher. 3. A method in which a coiled wire is unwound, straightened while being fed, heated to a temperature required for forging, and then sheared or cut to a predetermined length and forged. After straightening so that the radius of curvature is larger than before straightening in a range that does not become, before heating to the temperature required for forging, the straightened wire is heated to 400 ° C. or more, and then straightened straight. A wire forging method characterized by the following. 4. A rewinding means for a wire coil, a conveying means for feeding a rewinded wire, a straightening means for straightening the unwound wire, and a wire straightened by the straightening means at 400 ° C. or higher. Heating means for heating the wire heated by the heating means again, a second straightening means for improving straightness, and a wire straightened by the second straightening means and having improved straightness forged. Means for heating to a required temperature, means for shearing or cutting the wire heated by the heating means to a predetermined length, and means for forging the wire cut or cut by the shearing or cutting means are sequentially connected in series. A forging device for a wire rod, which is arranged in a shape. 5. A rewinding means for a wire coil, a heating means for heating a coiled wire to 400 ° C. or more during rewinding of the wire by the rewinding means, and a heating means for heating the coiled wire to 400 ° C. or more. Conveying means for feeding the unwound wire, straightening means for straightening the unwound wire, means for heating the wire straightened by the straightening means to a temperature required for forging, and heating Means for shearing or cutting a wire heated by the means to a predetermined length, and means for forging the wire cut or cut by the shearing or cutting means are sequentially arranged in series, forging a wire. apparatus. 6. A rewinding means for a wire coil, a conveying means for feeding a rewinded wire, a straightening means for increasing the radius of curvature of the rewinded wire so as not to be infinite, and a radius of curvature by the straightening means. Heating means for heating the increased wire to 400 ° C. or higher, second straightening means for straightening the wire heated by the heating means to form a straight line, and straightening by the second straightening means Second heating means for heating the drawn wire to a temperature required for forging, means for shearing or cutting the wire heated by the second heating and heating means to a predetermined length, and means for shearing or cutting the wire. A forging device for a wire rod, wherein means for forging a wire rod that has been sheared or cut by means are sequentially arranged in series. 7. The wire rod forging device according to claim 5, wherein the means for heating to 400 ° C. or higher is a high frequency heating device, and the coil shape of the high frequency heating device is a horseshoe shape or an oval shape. 8. A means for heating to 400 ° C. or higher is a direct current heating device, which comprises a pinch roller for supplying power and a pinch roller for returning current to a power supply device. The wire rod forging device according to claim 5 or 6, wherein