JPS643576B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is directed to a coil forming line for forming a straight rolled wire rod into a coil shape after passing through a final finishing mill for hot continuous wire rod rolling. This invention relates to a method of operating related equipment to improve the problem of the tail end having a defective shape.

(Prior Art) FIG. 6 shows an example of the layout of a hot continuous wire rod rolling mill. In this process, the billet is heated to hot rolling temperature in a heating furnace 1, rolled into a thick diameter wire rod in approximately 20 continuous rolling mills 2, and then divided into two into a winding machine line 3 and a finishing rolling line 4. A part of the wire rod is wound as is in the winding machine 5, but the other part is further rolled into a finer diameter wire rod in a block mill (finishing rolling mill 6), and then rolled into a wire rod with a pinch roll 8 and a loop layer 9 in a coil forming line 7 from a straight shape. It is formed into a coil shape and sent to an accumulation device 11 while being cooled on a conveyor 10.

FIG. 7 shows details of a part of the coil forming line, in which the hot rolled wire w passing through the guide pipe 12 is fed into the rotating curved guide pipe 13 of the loop layer 9 by the pinch rolls 8, and the coiled wire w is fed into the rotating curved guide pipe 13 of the loop layer 9. ₁ and the rollers 14 of the conveyor 10
It is transported in a domino-like state, partially overlapping and falling down.

In the connection system between the finishing rolling line 4 and the coil forming line 7 shown in FIG. It has a speed control device LED and is connected via a synchronous speed command system 18, and the pinch roll 8 and the loop layer 9 are operated at a set rotational speed of a certain synchronous ratio with respect to the rotational speed of the finishing rolling mill 6.

(Problems to be Solved by the Invention) In the above-mentioned connecting line, as shown in _FIG . The part is often a coiled wire rod _w2 with a small diameter.

When such a small-diameter coiled wire w ₂ is formed, it tends to get stuck between the rollers 14 of the conveyor 10 or get stuck on the core rod 19 of the accumulating device 11 as shown in FIG. Various troubles may occur, such as not being able to fall and accumulate smoothly, or the small diameter coil w ₂ becoming stretched out by the binding wire 20 during binding, as shown in FIG.

The present invention relates to the formation of the above-mentioned small diameter coiled wire _w2 ,
The purpose is to prevent troubles associated with this.

(Means, effects, and examples for solving the problems) As a result of various studies on the problems of the above-mentioned prior art, the following knowledge was obtained.

Regarding the specific structure of the equipment, FIG. 11 shows the arrangement relationship between the loop layer 9, the front pinch roll 8, and the rear conveyor 10, and FIG. 12 shows the internal structure of the loop layer 9. In this example, the loop layer 9 includes a pair of curved guide pipes 13.
is rotatably supported within the machine frame 22 by a bearing 23,
It is stably supported by a central rotary body 25 which is rotationally driven by a connection of bevel gears 24, and there appears to be no structural factor in forming the small diameter coiled wire during normal operation.

Next, a detailed examination of the forming condition of the tail end of the rolled wire rod w is as follows. In the above-mentioned connection line, when the tail end of the rolled wire rod w passes through the finishing mill 6, it is sent to the loop layer 9 by only the pinch rolls 8, where it is formed into a loop shape and placed on the conveyor 10. When the tail end of the rolled wire rod w passes through the pinch rolls 8, the feeding force to the loop layer 9 is only the inertial force of the wire rod, and the tensile force due to the force of rotation in the loop layer 9 to form it. As a result, the diameter of the coiled wire w ₂ at the tail end becomes smaller than the diameter of the coiled wire w ₁ when the feeding force of the pinch roll 8 is applied.

The present invention solves the problem of reducing the diameter of the tail end of the coiled wire rod, which is a problem in the prior art, because according to the study results, the speed of the rolled wire rod w suddenly increases when the tail end of the rolled wire rod passes through the pinch rolls 8. lowered, loop layer 9
The cause is that the speed at the exit of the curved guide pipe 13 is lower than the required speed, so as a corrective measure, the speed of the wire rod is increased to a certain extent in advance so that the tail end of the rolled wire rod passes through the pinch rolls and the wire rod The idea is to maintain the necessary and sufficient speed when passing through the loop layer even if the speed of the loop layer decreases.

The speed of the rolled wire w increases when the tail end is about to pass through the finishing mill 6, or immediately after passing, and the rotational speeds of the pinch rolls 8 and the loop layer 9 are increased. In this way, no tension is applied to the rolled wire rod between the finishing mill and the pinch rolls, and no adverse effects occur. Thereafter, when the tail end of the rolled wire rod passes through the pinch rolls, the rotations of the pinch rolls 8 and the loop layer 9 are returned from the accelerated state to a steady value. In this way, by appropriately selecting the timing of acceleration/deceleration and the degree of speed increase, the loop layer can be adjusted so that the tail end of the rolled wire rod, which has passed through the pinch rolls and is no longer receiving the feeding force, decreases in speed and falls to a steady value. be the exit of In this case, by making the speed increase rate of the pinch roll correspond to the speed increase rate of the loop layer, the tail end of the wire rod can be passed through the loop layer at high speed in a short time after leaving the pinch roll, so that the tail end of the wire rod coil This effectively prevents the diameter from becoming smaller.

In summary, the method for improving the tail end shape of a wire coil according to the present invention includes a finishing mill, a pinch roll, a loop layer, and a
In a coil forming line for rolled wire rods that is connected to a conveyor and an accumulator, a first wire rod detector is installed in the vicinity of the finishing mill, a second wire rod detector is installed immediately after the pinch rolls, and The rotational speed of the pinch roll and loop layer is increased from the steady value set speed by detecting the passing of the end, and the rotational speed of the pinch roll and loop layer is decreased to the steady value set speed by the detection of the wire tail end passing by the second wire detector. It is characterized by causing

Hereinafter, the present invention will be specifically explained mainly with reference to FIGS. 1 to 4.

In the present invention, for the connecting lines 4 and 7 for finish rolling and coil forming, as shown in FIG. _Immediately after the pinch roll 8, a second wire detector _D2 of the same type is provided to detect the passage of the tail end of the wire w.

FIG. 2 is a speed control diagram of the pinch roll 8, in which the vertical axis represents speed and the horizontal axis represents time. When the passage of the tail end of the rolled wire rod w is detected by the first wire rod detector D ₁ , the speed of the pinch roll 8 is increased from the steady value set speed v ₁ by the signal d ₁ and increases during the timer time t ₁ . Set the value as speed v ₂ and then maintain this speed v ₂ . When the passage of the tail end of the rolled wire rod w is detected by the second wire rod detector _D2 , the speed of the pinch roll 8 is decelerated from the rising value set speed _v2 by the signal _d2 , and the steady value is set during the timer time _t2 . Return to speed v ₁ . The timer times t ₁ and t ₂ are approximately 3 seconds or less, and the speed v ₂ of v ₁
It is appropriate to limit the increase in s ₁ to about 40% or less.

At the same time, loop layer 9 also increases/decelerates. FIG. 3 is a speed control diagram of the loop layer 9, in which the vertical axis represents speed and the horizontal axis represents time. Wire tail end passing signal
When d ₁ is detected, the speed of loop layer 9 is changed from the steady value setting speed v ₂ to the rising value setting speed v ₄ for the timer time.
The speed is increased at time _t3 , and when the signal _d2 is detected, the speed is decreased from speed _v4 to the steady value set speed _v3 at timer time _t4 .
The timer times t ₃ and t ₄ are also about 3 seconds or less, and the speed v ₄ is
It is appropriate that the increase s ₂ relative to v ₃ be about 20% or less.

FIG. 4 shows a speed control block diagram of the DC electric mechanisms 16 and 17 for driving the pinch roll 8 and the loop layer 9. Electric motor 16 or 17 is DC power supply 2
6 via a thyristor device 27 to control the rotation speed. The signal from the speed setting device 28 is sent to the speed controller 30 via the wire rod rising speed setting device 29 for the method of the present invention, and the rotational speed signal from the tacho generator 31 interlocked with the electric motors 16 and 17 is also used for speed control. The output is sent to the current controller 32 and compared with the current signal from the current detector 33 of the power supply circuit, and the output is input to the pulse generator 34, where the pulse The gate control of the thyristor device 27 is performed by this.

In connection with the implementation of the method of the present invention, in the case of a small diameter wire, the rear end portion _w3 of the coil may swell and come loose as shown in Fig. 5A, and in this case, the loop layer 9 Raise the speed quickly to tighten the rear end of the coil slightly as shown in Figure 5B. For this purpose, a third wire rod detector is installed at the exit of the final rolling mill of the continuous rolling mill 2 as shown in FIG.
D ₃ is provided, and the wire tail end detection signal d ₃ increases the trailing end speed of the wire from the steady value set speed v ₃ to the rising value set speed v ₃ as shown in the speed control diagram in FIG.
The speed is returned to _v5 by the signal _d2 of the wire detection point _D2 . The timer time for this speed control shall be approximately 3 seconds or less, and the speed increase _s3 shall be approximately 20% or less.

Furthermore, each of the above improvement circuits for carrying out the method of the present invention is interlocked with the circuit that applies wave control to the wire coil to prevent mutual influence.

(Effects of the Invention) As described above, according to the present invention, the shape of the tail end portion of wire coil forming is improved, and the forming process can proceed smoothly.

[Brief explanation of drawings]

Fig. 1 is a layout diagram of a wire detector in a coil forming line for implementing the method of the present invention, Fig. 2 is a speed control diagram of the pinch roll in the method of the present invention, and Fig. 3 is a speed control diagram of the loop layer in the method of the present invention. Control diagram; Figure 4 is a block diagram of the speed control device for the drive motor of the pinch roll and loop layer; Figure 5A is a diagram showing an example of the shape of the rear end of the coiled wire;
Figure 5b is a diagram showing the rear end tightened state;
Figure C is a wire rod rear end speed control diagram, Figure 6 is a diagram showing an example of the layout of a conventional hot continuous wire rod rolling mill, Figure 7 is a diagram showing some details of the coil section, and Figure 8 The diagram shows the connection diagram of the finishing rolling mill, pinch roll, and loop layer power supply and speed control device.
FIG. 9A is an explanatory diagram of the state of forming the coiled wire;
FIG. 9B is a longitudinal sectional side view of the accumulating device, FIG. 10 is a perspective view of the coiled wire in a bundled state, FIG. 11 is a side view showing the arrangement of the loop layer and the front and rear devices, and FIG. 12 is a side view of the loop layer. FIG. 1... Heating furnace, 2... Continuous rolling mill, 3... Winding machine line, 4... Finishing rolling line, 5... Winding machine, 6... Finishing rolling machine, 7... Coil forming line, 8 ... Pinch roll, 9 ... Loop layer, 10 ... Conveyor, 11 ... Accumulator, 12
... Guide pipe, 13 ... Curved guide pipe,
14... Roller, 15, 16, 17... DC motor, 18... Synchronous speed command system, 19... Core rod,
20... Binding wire, 22... Machine frame, 23... Bearing,
24...Bevel gear, 25...Center rotating body, 26...
DC power supply, 27...thyristor device, 28...speed setting device, 29...rising speed setting machine, 30...
Speed controller, 31... Tacho generator, 32...
Current controller, 33...Current detector, 34...Pulse generator, w...Hot rolled wire rod, _w1 , _w2 ,
w ₃ ... Coiled wire, LED ... Power supply speed control device, D ₁ , D ₂ , D ₃ ... Wire detector, d ₁ , d ₂ ,
d ₃ ... Signal, v ₁ , v ₃ , v ₅ ... Steady value setting speed,
v ₂ , v ₄ , v ₆ ... Rising value setting speed, t ₁ , t ₂ , t ₃ , t ₄ ...
...Timer time, s ₁ , s ₂ , s ₃ ... Increased amount.

Claims (1)

[Claims] 1. In a coil forming line for rolled wire rods that is connected to a finishing mill, pinch rolls, loop layer, conveyor, and accumulating device in the hot continuous wire rolling process, a first wire rod detector is installed in the vicinity of the finishing mill, and the wire rod detector is installed immediately after the pinch rolls. A second wire detector is provided, and when the first wire detector detects the passing of the wire tail end, the rotational speed of the pinch roll and loop layer is increased from the steady value set speed, and the second wire detector detects the passing of the wire tail end. A method for improving the shape of a tail end of a wire coil, characterized by reducing the rotational speed of a pinch roll and a loop layer to a steady value set speed by detection.