JPS62202028A - Feed abnormality detector in continuous annealing of long-sized pipe - Google Patents

Abstract

PURPOSE:To instantaneously detect the clogging of a material in an induction heater even during the slow moving after the start of a line and the acceleration period by monitoring line speeds not only on the inlet side but also the outlet side of the induction heater in a feeding method for pushing a long sized pipe into the induction heater by a leveling machine. CONSTITUTION:A conventional speed detector 8 is provided on the inlet side of the induction heater 3 of the continuous annealing line and a speed detector 9 is likewise provided on the outlet side. The copper pipe let off from a pay off table 1 is fed by the leveling machine 2 to the heater 3 by which the copper pipe is heated and softened. The heated pipe is coiled by pinch rollers 4 and a coiler 5. The inlet side and outlet side speeds V1, V2 of the heater 3 are detected by the detector 8. A difference arises between the speeds V1 and V2 when the material is clogged in the heater 3. A line command speed V0 and the optional two speeds of the speeds V1, V2 are subjected to relational calculation by taking the case in which the speeds V1, V2 both fluctuate into consideration. An alarm is emitted or the line is subjected to emergency stop in accordance with the output thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a device for detecting feeding abnormality of a long tube in a continuous annealing line using a continuous annealing device for long tubes.

(Prior Art) Generally, long metal pipes are straightened by annealing a material pipe formed by drawing or the like. Among these, regarding annealing treatment, conventionally the manufactured material tube was wound into a coil shape and box annealed, but the processing time was extremely long and this was a bottleneck in improving the productivity of long tubes. It had become.

For this reason, attempts were made to develop a technology for continuous annealing of long tubes, similar to the continuous annealing of strips, and in order to increase the annealing line speed, continuous annealing lines using induction heating equipment were developed. It has become possible to put it into practical use. However, the shape of the material is different from continuous annealing of steel strips, and this softens due to annealing, making it impossible to transport the annealed long tube under high tension. Great care must be taken when transferring materials on the line. In particular, in the case of continuous annealing of materials that are softer than steel pipes, such as long copper pipes, there is a serious problem of material clogging caused by local melting or bending of the material pipe in the induction heating device, which reduces yield. and a decline in productivity.

For example, continuous annealing of long copper tubes, such as thin-walled tubes and internally grooved tubes,
As shown in FIG. 3, the steel pipe paid out from the payoff table 1 is fed to the induction heating bag ff13 by the straightening machine 2 and heated by an induction heating coil. The steel pipe that has become soft after heating passes through pinch rolls 4 and a coiler 5 and is wound onto a receiving table 6. Note that 7 is a cutting machine. In such a continuous annealing line, if material becomes clogged in the induction heating coil during continuous annealing, conventionally, as shown in the figure, a speed detector 8 installed between the straightening machine 2 and the induction heating device 3 A configuration in which the material feeding speed v1 is detected by , and when the detected speed v1 becomes below the emergency stop setting speed Vs after acceleration is completed, the line is brought to an emergency stop to minimize material clogging in the induction heating device. was taken. Note that the material (copper V) is fed so as to be forcibly pushed into the induction heating device by a straightening roll of a straightening machine.

(Problem to be Solved by the Invention) However, the operation of the above-mentioned continuous annealing line is divided into slow motion and acceleration periods after the start, and a steady period where the top speed reaches a steady state after the completion of acceleration. Since the slow motion and acceleration periods are set to be as short as possible and the speed is quickly brought to a steady state, the emergency stop setting speed Vs must be set to a value slightly smaller than the top speed Vt.
Therefore, the period from the start to the top speed after completion of acceleration is an unmonitored section, and no abnormality can be detected. In addition, even if the material becomes clogged in the induction heating device, the material is pushed into the induction heating device by the straightening machine 2, so the clogging phenomenon is not immediately detected by the speed detector, and the material Since blockages are accumulated and detected only when they reach the speed detector, the detection time is delayed. Therefore, there are problems in that not only the yield of the material decreases, but also the induction heating device may be damaged or the recovery time when the material is clogged is prolonged, leading to a decrease in the operating rate.

These problems are not limited to the continuous annealing line for steel pipes mentioned above.
The same applies to I-tubes and the like, and the problem was particularly large in continuous annealing of thin-walled long tubes, internally grooved long tubes, extremely small-diameter long tubes, and the like.

The purpose of the present invention is to eliminate the drawbacks of the above-mentioned prior art related to continuous annealing of long tubes, and to provide a material that can be easily annealed in an induction heating device, not only during the slow motion and acceleration periods from the start of the line, but also in the steady state after the completion of acceleration. To provide a feeding abnormality detection device capable of instantaneously detecting clogging without delay in detection time, and enabling high yield and high operating rate.

(Means for Solving the Problems) In order to achieve the above object, the inventors of the present invention have devised a method in which a long tube, which is a material to be treated, is fed into an induction heating device by being pushed through a straightening machine. In addition to installing a line speed detector between the straightening machine and the induction heating device as in the past, we also installed it on the outlet side of the induction heating device to control the line speed at the entrance and exit sides of the induction heating device. The present invention was made based on the knowledge that this is possible by monitoring.

That is, the gist of the present invention is to provide an apparatus for continuously annealing a long tube in a line in which a straightening machine, an induction heating device, and a pinch roll are arranged from the input side, and a straightening machine, an induction heating device, and a pinch roll are arranged between the straightening machine and the induction heating device. A speed detector provided at each outlet side of the device, and arbitrary two speeds of the inlet side speed V□ and outlet side speed v2 of the induction heating device detected by the speed detector, and line command speed vl, are detected by the speed detectors. A feed abnormality detection device for continuous annealing of a long tube, comprising a comparison calculator for comparison, and configured to issue an alarm or make an emergency stop of the line based on the output signal of the comparison calculator;
It is in.

The present invention will be explained in detail below based on examples.

(Example) Figure 1 is a diagram showing the continuous annealing line of a thin-walled long copper pipe.
In the figure, 1 is a payoff table, 2 is a straightening machine, 3 is an induction heating device, 4 is a pinch roll, 5 is a coiler, 6 is a receiving table, and 7 is a cutting machine. This is similar to the conventional continuous annealing line shown in the figure.

Note that the material (long copper tube) is pushed into the induction heating device 3 by the drive roll of the straightening machine 2, and since the material after heating is soft, the pinch roll 4 and coiler 5 are used to push it into the induction heating device 3. It is guided onto the table 6 and wound up.

In this continuous annealing line, a speed detector 8 was conventionally provided between the straightening machine 2 and the induction heating device 3, but in the present invention, in addition to this configuration, the A speed detector 9 is also provided between the pinch roll 4 disposed on the exit side (front) of the induction heating device 3, and the inlet speed v1 and the exit speed v2 of the induction heating device 3 are
Detect.

Note that the line command speed v0 can be detected by a pulse generator or the like from the driving rotation part of the drive roll of the straightening machine 2.

During line operation, if material clogging occurs in the induction heating device 3, the above-mentioned inlet speed V and outlet speed V
2, so monitoring is possible by detecting the difference6. However, if both the inlet speed v1 and the outlet speed v2 fluctuate, monitoring may become impossible.
Entrance side or exit side speed V1 with respect to line command speed v0. ．．
Each speed difference of V2 (■o-v), (V, -V,)
to monitor by detecting. Therefore, if any of the following equations (1), (2), and (3) is satisfied, it is determined that a clogging phenomenon has occurred in the induction heating device, and the line is urgently stopped as necessary.

In the above formula, the suffix 1 for α, β, and γ represents a coefficient for warning of the occurrence of a feed abnormality, 2 represents a coefficient for emergency stop of the line, and β1 × β2. β, Kunao, in the above formula, α,
The suffix 1 attached to β and γ indicates that it is a coefficient for warning of the occurrence of a feed abnormality, and 2 indicates that it is a coefficient for making an emergency stop of the line.
2, β, β7, γ1, γ2 are each arbitrarily set, for example, between 0<(αβ2), (ββ2), (γγ,)<0.5. This makes it possible to detect feeding abnormalities or material jams in two steps.

The configuration of the feed abnormality detection device is 5.For example, if shown in the block diagram shown in FIG. The signal is input to the device 11. On the other hand, the inlet speed V of the induction heating device 3 is detected by the speed detector 8, and the outlet speed V2 is detected by the speed detector 9, and after D/A conversion, they are input to the comparator 11. The comparison calculator 11 calculates the difference between the detected speeds v0, vl, ■, and calculates the difference between the detected speeds v0, vl, ■, and calculates the coefficients α1, β2.
, β1, β2, γ1, γ2, the above formula (1), (
Calculate and determine whether either of 2) or (3) is satisfied. If any speed difference indicates a feed abnormality, an alarm signal is output and input to the induction heating device as necessary. In some cases, a line emergency stop signal is output, and the drive of the roll drive motor 10 of the straightening machine 2 is stopped.

In the conventional material jam detection device, as shown in FIG. 4, the emergency stop speed Vs (Vt
> Vs), so even if the induction heating device is activated during the acceleration period and a material jam occurs and the outlet speed v2 fluctuates as shown in the curve in the figure, this will not occur. It was impossible to detect. On the other hand, according to the present invention, since the inlet and outlet speeds of the induction heating device can be constantly detected from the start of the line and fluctuations in the feeding state can be monitored, it is possible to match the line speed and the operating conditions of the induction heating device. This improves the reliability of line operation, especially during acceleration, and improves material yield. Of course,
Since the occurrence of material clogging can be detected instantaneously, the line can be immediately stopped in an emergency during any period, and damage to the heating device can be reduced as much as possible.

(Effects of the Invention) As described in detail above, according to the present invention, it is possible to constantly monitor the material feeding state of the line during continuous annealing of long tubes, and to prevent feeding abnormalities such as material clogging in the heating device. Since this can be detected instantly from the start of the line to the steady state, damage to the heating device can be effectively prevented, and recovery time in the event of material clogging can be shortened. In addition, since the line speed and operating conditions of the heating device can be matched while monitoring the material feeding status, it is possible to particularly speed up the acceleration period, perform efficient continuous annealing, and improve material yield. . In particular, the present invention is suitable for continuous annealing of thin-walled long materials such as copper pipes, materials with internal grooves, and the like.

[Brief explanation of drawings]

Fig. 1 is a diagram showing an example of equipment arrangement in a continuous annealing line for long tubes in an embodiment of the present invention, Fig. 2 is a block diagram of the feed abnormality detection device of the above embodiment, and Fig. 3 is a conventional feed abnormality detection device. FIG. 3 is a diagram showing the arrangement of a detection device. FIG. 4 is a diagram showing the speed mode of the continuous annealing line. 1... Payoff table, 2... Straightening machine, 3...
・Induction heating device, 4...pinch roll, 5...
・Coiler, 6...Receiving table, 7・
...Cutting machine, 8.9...Speed detector, 11...
Comparison operator. Patent applicant Takashi Nakamura, Patent attorney representing Kobe Steel, Ltd. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. An apparatus for continuously annealing a long tube in a line in which a straightening machine, an induction heating device, and a pinch roll are arranged from the input side,
A speed detector provided between the straightening machine and the induction heating device and on the exit side of the induction heating device, and an inlet speed V_1 and an exit speed V_ of the induction heating device detected by the speed detectors.
2 and line command speed V_0, and is configured to issue an alarm or make an emergency stop of the line based on the output signal of the comparison calculator. Feed abnormality detection device for continuous annealing of long tubes. 2 The comparison calculator calculates (V_0-V_1)V_0≧α
_1 or α_2, (V_0-V_2)/V_0≧β_1
or β_2, (|V_1−V_2|)/V_0≧γ_1
or γ_2 (where suffix 1 is a constant for issuing a warning and 2 is a constant for emergency stop), the device determines that there is a feed abnormality.