JPH0679743B2 - Continuous hot tension straightening device - Google Patents

Description

The present invention relates to a device for correcting the bending of a wire such as a titanium alloy wire.

[Conventional technology]

Generally, in order to straighten ordinary steel wires and the like, so-called roller levelers and spinner straightening machines, which apply the principle of repeated bending straightening, are often used. However, when a material having a high elastic limit and a low elastic modulus, such as a titanium alloy wire, is to be straightened, even if a roller leveler or the like is used, the amount of plastic deformation is insufficient and a good straightening effect cannot be obtained.

Therefore, as a method of correcting a titanium alloy wire or the like, conventionally, a stretch leveler that simply gives tensile elongation to the wire has been used. In this case, the stretching process is performed warm or hot in order to prevent residual stress from remaining in the wire after stretching.

As shown in FIG. 5, the stretch leveler fixes both ends of the wire rod 11 to the gripping devices 101, 101, contacts the energizing electrodes 102, 102 to the inside of the gripping devices 101, 101, and energizes the power source 100 to sandwich the electrodes 102, 102. The wire rod 11 in the separated portion L is heated uniformly. After that, the gripping device 10
1,101 is moved to stretch and straighten the wire rod 11, then cooled, the grip is removed, and the wire rod is cut to obtain a straight rod.

[Problems to be solved by the invention]

 However, the above conventional technique has the following drawbacks.

(1) Only the portion L sandwiched between the electrodes 102, 102 is subjected to the correction action, and the wire rod portion outside the electrodes 102, 102 is not subjected to the correction and does not become a product, so the yield is low.

(2) If the straightening length is increased to improve the yield,
Due to its own weight, the wire rod sags and bends. That is, in principle, a long product cannot be produced.

(3) Productivity is low due to intermittent operation.

(4) Coil products cannot be made.

On the other hand, a straightening device that can be continuously operated has also been proposed (Actual No. 55-82144). However, the technique described in Japanese Utility Model Publication No. 55-82144 also has the following drawbacks.

The tension is simply given by the friction force of the pinch roller,
This gives too little tension.

Although straightening is done cold, the residual stress does not disappear and straightness is low.

For the above reasons, this example can be applied only to a very soft material and a thin wire, and cannot be used for a wire having a high elastic limit and a low elastic modulus intended by the present invention.

[Means for solving problems]

An apparatus of the present invention for solving the above problems is an apparatus for straightening a wire rod having a high elastic limit and a low elastic modulus; an inlet drum arranged at intervals in the line direction and around which the wire rod is wound. And a delivery side drum, at least one pinch roller provided on the circumference of each of the drums to increase the frictional force between the delivery material and the drum by applying a pressing force to the delivery material, and the input side drum and the delivery side drum. And a line adjuster sequentially provided from the upstream side to the downstream side, a heating device for heating the wire rod, and a cooling device for cooling the wire rod.The line adjuster mechanically corrects the bending of the wire rod and continues. A continuous hot tension straightening device, which is a means for matching the line center of the heating device.

[Action]

In the present invention, a wire is wound around a rotary drum in which at least one pinch roll is arranged, and a heating device and a cooling device are provided between the rotary drums while pressing down the pinch roll to stretch and straighten the wire. Therefore, since sufficient tension can be obtained,
Titanium alloy wire rods and the like have a high elastic limit, and even a wire rod having a low elastic modulus can be sufficiently corrected.

Further, since the straightening is performed by continuously supplying the wire rod to the rotary drum, the yield is improved.

Further, since this kind of wire is wound in a coil shape, it has a curl (curl) as shown in FIG. When a large tension is applied to this wire, the wire apparently becomes straight, but as a reaction thereof, a bending moment remains as shown in FIG. When this wire is partially heated, that part becomes soft, and therefore plastic deformation occurs due to the residual bending moment.
It looks like it folds as shown. As a result, the pass line is not straight, and the wire rod bends sharply at the heating point. Due to this bending habit, a new bending habit is attached to the wire, and the straightness is reduced.

The present inventors have found that in order to prevent such a phenomenon, the residual bending moment at the scheduled heating point should be removed. As a means for removing this residual bending moment, the line adjuster according to the present invention is provided.
Light bending is applied to mechanically correct the three-dimensional bending of the wire so that it coincides with the line center of the heating device as the subsequent drawing point.

On the other hand, in the present invention, the wire is cooled after being heated by the heating device and before being wound on the output drum. This cooling device, the present invention is intended to straighten a wire rod having a high elastic limit and a low elastic modulus, and since it is necessary to apply a large tension, it is indispensable to wind the wire rod on the delivery side drum. In order to prevent the occurrence of new bending habit in the output side drum and to improve the straightness, the wire rod is cooled before winding to increase the elastic limit of the material.

[Specific configuration of the invention]

The present invention will be specifically described below with reference to the drawings. First, an outline of a specific example of the device of the present invention will be described with reference to FIG. The wire 11 to be straightened is preliminarily straightened by the leveler 2, the auxiliary heating induction coil 3 and the leveler 4 via the inlet pinch roller 1. Then, the wire 11 is wound around the entrance drum 5 and pressed down by the pinch roller 5 '. Then wire
The line 11 is heated by the main induction heating coil 7 while the path line is adjusted by the line adjuster 6 and then cooled by the air ejected from the air-cooling nozzle 8.
Wrapped around. The output drum 9 has a rotational speed higher than that of the input drum 5, and the wire rod 11 is stretched by the frictional force between the drum 9 and the wire rod 11 and the pressing force of the pinch roller 9'to reinforce it. . Thus pinch rollers
After 10, the wire product which is the product after straightening is obtained.

Next, the device of each part constituting the device of the present invention will be explained in more detail below.

The drum device according to the present invention, that is, the inlet drum 5 and the outlet drum 9 are devices that generate tension for stretching the wire 11 by winding the wire 11 around a rotating drum and utilizing the frictional force between the drum and the wire. Is. At that time, the wire rod is stretched by slightly increasing the rotation speed of the outlet drum 9 from the inlet drum 5. The drum device must be constructed as follows to achieve the intended purpose.

(1) The larger the number of windings of the wire wound around the drum is, the higher the tension-carrying capacity is, which is desirable. The solution to this is drum 5,
One or two or more pinch rollers 5 ', 9'are arranged on the circumference of 9 circles, and the pressing force thereof enhances the frictional force between the drum and the wire 11. By appropriately setting the pressing force and the number of pinch rollers according to the required tension, the number of turns can be reduced to one, which is the minimum. In this device, it is desirable to cut a groove corresponding to the wire diameter on the pinch roll surface to reduce the surface pressure applied to the wire. When the frictional force is insufficient, it is effective to apply a driving torque to the pinch rolls 5'and 9'to increase the tension.

(2) In a drum that is generally used to feed a wire, the wire moves in the drum circumferential direction and at the same time moves in the drum axial direction by the wire diameter per rotation. In order to make this axial movement smooth, the drum surface is tapered in the axial direction so that the diameter gradually decreases. In that case, since the drum peripheral speed differs depending on the axial position, a slight slip occurs between the drum and the wire. However, in the case of the drums 5 and 9 with the pinch rolls 5'and 9'of the present invention, if the above-mentioned slippage occurs in the drum surface, the plastic elongation of the wire becomes unstable and a sufficient straightening effect can be obtained. Therefore, the taper angle needs to be zero. Therefore, since it is difficult to move the wire rod in the drum axis direction, the number of turns is minimized from this point of view.

(3) Since the straightening work is performed between the inlet side drum 5 and the outlet side drum 9, the drum diameter is selected by the following equation so that the wire rod will not be plastically deformed during winding on the outlet side drum 9.

Here, D: drum diameter, d: wire rod, E: elastic modulus, б _y : yield stress of wire rod at winding temperature, б _L : deformation resistance of wire rod at heating temperature.

If this condition is not satisfied, the straightened wire will be bent again when wound around the drum, and the straightness will decrease.

Next, in the present invention, a heating device, that is, the main induction heating coil 7 is installed between the inlet drum 5 and the outlet drum. When heated by the heating coil 7 in a state where tension is applied by the drums 5 and 9, the wire is stretched and straightened at the same time. When the drums 5 and 9 rotate, the wire rods are supplied one after another, straightened, and then exit, so that a continuous straightening operation is possible.

The heating method is not particularly limited as long as it can be heated in a short time, but high-frequency induction heating is high in that it has high temperature rising ability, can be heated in a non-contact manner, scratches are unlikely to occur on the wire, and temperature control is easy. It is suitable.

The cooling in the present invention is necessary to lower the winding temperature on the outlet drum 9 as much as possible. That is, from the above equation, it is advantageous to reduce the winding temperature and increase б _y in order to design the drum diameter smaller. However, rapid cooling causes thermal stress to be generated in the wire and reduces the straightness. Therefore, forced air cooling or natural air cooling is specifically preferable.

Next, the line adjuster used in the present invention will be described.
One purpose of the apparatus of the present invention is to process a coiled wire. Of course, the coiled wire is strongly bent. Therefore, as shown in Fig. 2, the path line centers of all the devices of the straightening line are regulated by the guide rolls 12 and 12 so that they are statically aligned with each other. I won't. That is, as shown in FIG. 2, the wire rod bends and enters the main induction heating coil 7 while being bent, and becomes straight by heating and goes out in a straight line. point)
In this case, the curvature becomes discontinuous, so that good straightness cannot be obtained. Therefore, the pass line is not in a static state, but needs to be dynamically adjusted while the wire rod is actually running. The line adjuster device is used for this purpose.

The function of this device is to give the wire a light bend on the entry side so that the traveling directions of the wire coincide with each other at the stretching point. Generally, the bending of the wire before straightening is three-dimensional, and it is necessary to adjust the pass line both in the vertical plane and in the horizontal plane.

As a concrete example of this device, the present inventors have shown in FIG.
We devised a roll bending device. In the figure, each roll is formed with a groove adapted to the wire. Figure 3 (a),
In (b), the wire 11 is fixed to the fixing roll 14 and the pressing roll 13
And the warp roll 13 is moved in the arrow direction by a roll chock (not shown) to correct the warp of the wire rod in the vertical plane. Similarly, in FIGS. 3 (c) and 3 (d), the wire rod 11 is sandwiched between the fixed roll 15 and the moving roll 16, and the moving roll 16 is moved in the arrow direction by the roll chock to bend the wire rod in the horizontal plane. And adjust the pass line.

The above device is the skeleton of the correction according to the present invention. Next, the front and rear devices necessary for operating the above device will be described.

(1) Payoff An apparatus for placing a wire rod coil and feeding the wire rod to a straightening device, which is usually used in a wire drawing machine or the like, and has no problem. For example, there is a method in which a coil is placed on a turntable and a wire is fed horizontally.

(2) Roller leveler (Figs. 1 and 2) Slightly reduces the extreme bending of the wire rod supplied from the payoff and stabilizes the pass line. However, little correction effect is expected.

(3) Entry-side pinch roller (Fig. 1, 1) A drive-type pinch roller is installed on the entry side to counter the straightening tension in order to suppress the slip of the wire on the drum and stabilize the feeding performance of the wire. However, it is desirable to apply backward tension to the drum. However, this device can be omitted if the correction tension is low.

(4) Output side pinch roller (Fig. 1, 10) This stabilizes the feeding performance of the wire rod on the output side drum, and its purpose and structure are exactly the same as the input side pinch roller. It has the purpose of interrupting tension fluctuations from the cutting or coiling equipment described.

(5) Cutting device This is a device for cutting the wire sent from the delivery drum into a certain length when the final product is a straight rod. Specifically, it comprises a measuring device and a device for cutting the wire rod based on the measuring data. The cutting device is preferably a so-called flying cutter that cuts in synchronization with the moving speed of the wire so as not to interfere with the feeding of the wire.

(6) Coil winding device When the final product is a coil, a coil winding device is installed in place of the above cutting device. Of course, the winding diameter must be large enough so that bending does not cause plastic deformation.

(7) Preliminary straightening device The basic effects of straightening work can be sufficiently obtained by the above group of devices, but since the bending of the wire coil, which is the material, is quite large, the straightness obtained in one straightening work is self-correcting. There is a limit. Therefore, when a particularly high straightness is required, a pre-straightening device as shown in FIG. 4 is used.

In the figure, the part surrounded by the dotted line between the entrance side drum 5 and the roller leveler 2 is the preparatory straightening device 17, which comprises the heating coil 3 and the auxiliary roller leveler 2 '. This action is to soften the material by heating and straighten the roller at a high temperature by the auxiliary roller leveler 2 '. Since the pulling force of the roller leveler 2 on the inlet side acts as line tension, it has some effect on straightening. Further, when the wire rod coil 11 is contaminated with lubricant or dirt, it is eliminated by heating, and the surface of the wire rod is oxidized to increase the frictional force with the drum and improve the feeding property. Note that induction heating is desirable so that heating can be performed in a short time. The auxiliary roller leveler may have a system in which 5 to 10 rollers are arranged in a straight line and repeatedly bent, but it is effective to apply a heat insulating coating such as ceramic coating to the roller in order to prevent temperature decrease.

〔Example〕

 Examples will be described below.

(Example 1) Straightening was performed under the following conditions (1) to (3).

(1) Equipment specifications Drum diameter = 1600mmφ, drum pinch roller = number of 4, rolling force 800kg, heating = 400kHz induction heating, cooling = natural cooling line adjuster = roll number 4, roll diameter 50φ inlet side leveler = horizontal 5 rolls, Vertical 5 rolls, roll diameter 80
φ Input side pinch roller = Rolling down force 800kg Output side pinch roller = Rolling down force 1200kg Line adjuster to stretching start point distance = 40mm (2) Operating condition Output side drum / Input side drum speed = 1.02 Input side drum speed = 1m / min Heating Temperature = 700 ℃ Outlet drum winding temperature = 180 ℃ (3) Material Ti ₆ Al ₄ V alloy wire rod (drawing wire) 6.4mmφ, coil diameter 1200φ The straightness of the straightened wire rod was measured. A straightness of 0.09 to 0.24 mm was obtained, which was good.

(Example 2) In addition to the conditions of Example 1, a pre-correction device was installed. The operating conditions and the like are the same as in Example 1.

(1) Heating device = 400kHz induction heating, temperature 520 ° C (2) Auxiliary roller leveler = horizontal 5 rolls, vertical 5 rolls type, roller diameter 35mmφ, alumina ceramic coating As a result of straightening under the above conditions, per 300mm length after preliminary straightening The straightness was 8 mm, and the straightness was 0.03 to 0.05 mm after this straightening.

〔The invention's effect〕

As described above, in the present invention, since the wire is wound around two drums and the heating device is provided between the drums to continuously correct the wire, the productivity is high and the yield can be improved.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of a continuous straightening device of the present invention, FIG. 2 is a diagram showing a pass line when a wire rod is running, and FIG. 3 is a diagram showing line adjustment by a 4-roll bender ((a), (b)). Respectively,
Correction of the downward warp and upward camber, (c) and (d) are diagrams showing correction of the left warp and right warp coils, respectively.) FIG. 4 is a diagram of a pre-correction device, and FIG. 5 is a conventional correction device ( FIG. 6 to FIG. 8 are views for explaining the bending habit and the residual bending moment. 1 ... Entrance pinch roller, 2 ... Roller leveler, 2 '...
… Auxiliary roller leveler, 3 …… Heating coil, 4 …… Roller leveler, 5 …… Inlet side drum, 5 ′ …… Pinch roller, 6
...... Line adjuster, 7 ... Main induction heating coil, 8 ...
… Air-cooling nozzle, 9 …… Outlet drum, 9 ′ …… Pinch roller, 10 …… Exit pinch roller, 11 …… Wire rod, 12 …… Guide roll, 13 …… Pressing roll, 14,15 …… Fixed roll, 16
...... Movement roll, 17 …… Preliminary straightening device, 100 …… Power supply, 1
01 …… Grip device, 102 …… Current-carrying electrode, L …… Wire part sandwiched between current-carrying electrodes.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tetsuya Kuwayama 5-15 Kitahama, Higashi-ku, Osaka, Osaka Prefecture Sumitomo Metal Industries, Ltd. (72) Mitsuru Masuda 5-15 Kitahama, Higashi-ku, Osaka, Osaka Sumitomo Metal Industries Co., Ltd. (56) References: 60-103575 (JP, U)

Claims (3)

[Claims] 1. An apparatus for straightening a wire rod having a high elastic limit and a low elastic modulus; an inlet drum and an outlet drum which are arranged at intervals in the line direction and around which the wire rod is wound; At least one pinch roller is provided on the circumference of each drum to increase the frictional force between the wire rod and the drum by applying a pressing force to the wire rod, and between the inlet side drum and the outlet side drum from the upstream side to the downstream side. It is equipped with a line adjuster sequentially provided on the side, a heating device for heating the wire rod, and a cooling device for cooling the wire rod, and the line adjuster mechanically corrects the bending of the wire rod to match the line center of the subsequent heating device. A continuous hot tension straightening device characterized by being a means. 2. A coil supply device upstream from the inlet drum,
The apparatus according to the above-mentioned item 1, wherein a product cutting device or a coil winding device is arranged on the downstream side of the delivery drum. 3. The apparatus according to claim 1, further comprising a pre-correction device provided with a heating device and a leveler device on the upstream side of the entrance drum.