JP3533080B2 - Travel control device for welding bogie - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel rolling line and a surface for performing endless operation by joining a leading end of a succeeding steel plate to a tail end of a preceding steel plate. The present invention relates to a welding bogie for welding front and rear steel plates in a running line in a processing line or the like. [0002] In order to weld a moving steel plate, it is necessary to make the relative speed between the steel plate and a welding cart zero. In the case of a line where the line speed itself can be reduced to zero, there is no problem. However, if that is not possible, a steel plate storage device called a looper is conventionally provided in the line for surface treatment lines, etc. Alternatively, it was possible to stop and weld the steel plate on the opposite side of the storage device while maintaining the speed of the production line on the delivery side. However, when the steel sheet is thick and temperature control is strict, as in the case of rough bar welding in a hot rolling line, it is impossible to reduce the steel sheet speed to zero using a looper or the like. Therefore, in such a case, the welding cart is made to follow the moving speed of the steel sheet. That is, in a state where the restraining of the welding bogie with respect to the steel sheet is released as shown in FIG. 3, when the leading end of the rear steel sheet is to be welded to the tail end of the preceding steel sheet, the welding is performed as shown in FIG. When the traveling of the bogie is started to increase the speed of the preceding steel plate (the rolling speed of the downstream finishing mill) and the traveling speed of the welding bogie matches the speed of the preceding steel plate, as shown in FIG. Then, the speed increase of the welding bogie is stopped, and the preceding steel plate is held (detained) by the preceding material clamper on the welding bogie. Thereafter, when the following steel plate is accelerated and its tip reaches a predetermined position of the welding bogie as shown in FIG. 6, the acceleration of the following steel plate is stopped, and as shown in FIG. Hold row steel plate. Then, as shown in FIG. 8, the leading end of the succeeding steel plate is welded to the tail end of the preceding steel plate while driving the welding cart at the same speed as the steel plate. In order to carry out such welding during traveling without any problem, it is necessary to make the traveling speed of the welding bogie strictly follow the speed of the preceding steel plate and to make the relative speed between the steel plate and the welding bogie zero. It is essential that the bogie has a speed control device. FIG. 9 shows an outline of a conventional welding truck speed control system. Laser Doppler type plate speedometer 51
The steel plate is detected by the reflection of the laser beam applied to the steel plate, and the amount of movement of the preceding steel plate is detected from the frequency shift of the reflected light. During the detection of the steel plate, a speed synchronization pulse synchronized with the speed of the preceding steel plate is generated. A pulse generator 52 is coupled to a roller that rotates at a peripheral speed substantially the same as the moving speed of the preceding steel plate in the case where the laser doppler plate speedometer 51 cannot be installed or the speedometer fails. The pulse generator 52 generates one speed synchronization pulse per rotation of the roller at a predetermined minute angle. Target generator 6
0 calculates the speed of the preceding steel sheet based on the speed synchronization pulse generated by the sheet speed meter 51 or the pulse generator 52.
When the tail end of the preceding steel plate passes through the steel plate detector 53, the steel plate detector 53 switches from detecting the steel plate to non-detection, and in response to this, the target generator 60 counts the speed synchronization pulse (measures the travel distance of the tail end). ), And an acceleration pattern (speed target value corresponding to the count value, ie, time) for increasing the traveling speed of the welding bogie to the speed of the preceding steel plate during the traveling of the welding bogie for a substantially predetermined length. The speed target value distribution of the sequence is determined by calculation, and the speed target value corresponding to the count value of the speed synchronization pulse is output to the subtractor 11. On the other hand, the pulse generator 41 generates a speed synchronization pulse of one pulse per rotation of the wheel of the welding bogie at a predetermined minute angle, and the actual speed value representing the traveling speed of the welding bogie is given to the subtractor 11. The subtractor 11 calculates the speed deviation = (speed target value−
Speed actual value) to the speed control device 12. The speed control device 12 is usually a PID (proportional, integral, differential) calculator and supplies an energizing current value corresponding to the speed deviation to the motor driver. That is, a motor current value for reducing the speed deviation to zero is calculated, and the calculated motor current value is used as a target current.
0d. The motor driver 20d energizes the electric motor 20m so that the energized current value of the electric motor 20m that rotationally drives the wheels of the welding cart becomes the target current value. [0007] In order to adjust the stationary welding bogie to the moving speed of the preceding steel plate, it is necessary to perform strict speed control using the steel plate speed as a speed target value. On the other hand, considering that the welding bogie completes speed synchronization with the preceding steel plate and holds (constrains) the leading and trailing steel plates and the tail end for welding, the steel plate is welded at the tip or tail end. When the speed of the welding bogie does not completely match the rolling speed of the rolling mill or the pinch roll because the other is restrained by the bogie and the other is restrained by the hot rolling finish rolling mill or the pinch roll for threading. However, as shown in FIG. 10, there is a problem that the speed difference is accumulated as the tension of the steel sheet. Therefore, after the welding cart restrains the preceding and succeeding steel plates, it is necessary to more precisely control the speed of the welding cart, but in reality, the pulse generator 41,
It is not possible to completely match the speed of the welding bogie to the speed of the steel sheet due to errors in the speed detectors such as No. 52, deterioration in control performance due to noise, and disturbances in the threading speed caused by roll wear of rolling mills and pinch rolls. It is possible. For this reason, usually, by applying drooping to the speed control system of the welding bogie, even if there is a speed error, it is attempted to prevent the tension from fluctuating in the speed. In the case of the speed control of the welding bogie described above, the drooping means that the target torque of the welding bogie is adjusted according to the magnitude of the torque TS so that no steep torque fluctuation occurs in the electric motor 20m of the welding bogie. This is to correct the speed. For example, the speed of the preceding steel sheet (the bogie target speed) is S0, and the torque given to the preceding steel sheet by the rolling mill is T.
0, when the drooping gain is set to DG, the target speed correction value y1 = DG × S0 × TS / T0 (1) is used as the correction value, and the target speed of the welding bogie is reduced accordingly.
The drooping gain DG is determined according to the allowable range of the tension fluctuation of the preceding steel sheet. [0009] However, there is a problem that the initial speed following ability to the steel sheet is deteriorated by adding drooping. In addition, even after the steel sheet is restrained, there is a problem that the effect of the drooping is that the steel sheet tension is increased to some extent, so that the fluctuation of the steel sheet tension is inevitable. The present invention aims to remedy this kind of problem. SUMMARY OF THE INVENTION The present invention is directed to a method for holding a tail end of a moving preceding steel plate and a leading end of a succeeding steel plate, and traveling with the steel plate using welding means. In the travel control device of the welding bogie, the speed of the welding bogie is controlled until the welding bogie holds the tail end of the preceding steel plate and the tip of the succeeding steel plate. The traveling control method of the welding bogie is switched so as to output a resistance compensating torque and an acceleration / deceleration compensating torque corresponding to accelerating / decelerating the inertia of the welding bogie by the change of the speed target value. According to this, the welding bogie follows the steel plate speed by the speed control until the welding bogie restrains the tail end of the preceding steel plate and the tip end of the following steel plate, and the followability is high. Therefore, the time required for the speed of the welding bogie to synchronize with the speed of the steel plate can be shortened, the approach section of the welding bogie can be shortened, the relative speed error between the steel plate and the welding bogie can be reduced, and the mechanical strength of the clamper that holds the steel plate is set low There is an advantage that it can be done. On the other hand, after holding the steel plate, a running resistance compensating torque corresponding to the running resistance of the welding bogie and an acceleration / deceleration compensating torque corresponding to accelerating or decelerating the inertia of the welding bogie by the variation of the target speed value. Since the traveling control method of the welding bogie is switched so as to output the signal, the speed following capability of the welding bogie with respect to the steel plate is high even after the steel plate is held. In other words, the welding bogie generates a force that cancels its own running resistance and a force that accelerates and decelerates itself, but does not generate any resistance to the external force caused by the tension of the steel plate. The truck can move freely according to the difference in tension, and it is possible to prevent the tension from greatly changing. Thereby, even if the mechanical strength of the clamper holding the steel plate is set to be small, it is possible to prevent the tension from adversely affecting the welding operation. The acceleration / deceleration equivalent torque of the welding bogie is calculated by multiplying the acceleration / deceleration rate of the bogie by the inertia of the bogie. In the calculation of the bogie acceleration / deceleration rate, the target speed of the bogie is calculated. There are two types, a method using the actual speed value of the carriage and a method using the actual speed value of the bogie. FIG. 1 shows the configuration of an embodiment of the present invention.
The case where this embodiment is applied to the speed control device of the welding bogie shown in FIG. 9 will be described.
However, the torque generator 20 shown in FIG. 1 corresponds to the motor driver 20d and the electric motor 20m shown in FIG. 9 for the power transmission mechanism for connecting the output shaft of the electric motor 20m and the wheels. I do. The speed detector 40 in FIG. 1 includes a pulse generator 41 shown in FIG. 9 and a calculator for calculating the traveling speed (actual speed value) of the welding bogie based on the speed synchronization pulse generated by the pulse generator 41. The speed target value generated by the target generator 52 shown in FIG. 9 is given to the subtractor 11 of the traveling control device 10 and the C contact of the second switch SW2 shown in FIG. During speed follow-up control for the preceding steel sheet (FIGS. 3, 4,
5, 6) switch the first switch SW1 to the illustrated A contact side in order to perform strict speed control. As a result, the speed control by the feedback controller 12, which is a PID calculator, becomes effective, and the speed of the welding carriage is strictly controlled to the speed target value given by the target generator 60. When the speed following (speed synchronization) to the preceding steel plate is completed using the feedback controller 12 (FIG. 6),
The welding bogie holds the tail end of the preceding material and the tip end of the following material by the clamper (FIG. 7), but at the same time, holds the first changeover switch SW1 to the B contact side in the drawing. Switch SW
With the switching of 1, the output of the feedback controller 12 becomes invalid. Instead, a torque reference externally provided and a torque reference output from the acceleration / deceleration compensation torque calculator 13 corresponding to the running resistance compensation torque. Becomes effective. That is, the motor in the torque generator 20 (
Driver). Thereby, the traveling control device 10 becomes a control system that does not generate any resistance to an external force caused by the tension of the steel plate. The calculation of the acceleration / deceleration equivalent torque of the welding bogie by the pseudo-differentiator 14 and the multiplier 15 of the acceleration / deceleration compensation torque calculator 13 is based on the acceleration / deceleration rate of the welding bogie and the inertia value of the bogie given from the outside. Is calculated by multiplying the speed target value by a speed target value.
The changeover switch SW2 is in contact with the C contact side in FIG. 1)
Using the actual speed of the trolley, that is, the actual speed value (the second switch SW2 is in contact with the D contact side in FIG. 1)
There are two types. When it is desired to use a precise acceleration / deceleration rate of the bogie, the second switch SW2 is connected to the D contact side.
When the noise of the actual speed value becomes a problem, or when it is desired to control only the acceleration / deceleration of the speed target value sent from the target generator 60, the second switch SW2 is brought into contact with the C contact. The speed target value and actual speed value (SPEED) of the welding bogie using the traveling control device 10 described above, the tension of the succeeding steel plate (TENSION 1) and the tension of the preceding steel plate (TENSION 2)
FIG. 11 shows a control example according to the conventional control system shown in FIG. 9 as a comparative example. All data are after completion of speed following (speed synchronization) to the preceding steel plate. In the case of the conventional example shown in FIG. 11, it can be seen that the steel sheet tension greatly fluctuates due to the speed disturbance after holding the steel sheet. On the other hand, according to the embodiment shown in FIG. 1 of the present invention, as shown in FIG.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an outline of a device configuration according to an embodiment of the present invention. FIG. 2 shows a target speed and an actual speed of the welding bogie when the embodiment shown in FIG. 1 is used for controlling the traveling speed of the welding bogie.
5 is a graph showing (SPEED), the tension of the succeeding steel sheet (TENSION 1), and the tension of the preceding steel sheet (TENSION 2). FIG. 3 is a block diagram showing a positional relationship among a leading steel plate, a succeeding steel plate, and a welding trolley for welding them to make them continuous, showing a state where the welding trolley is on standby. FIG. 4 is a block diagram showing a positional relationship among a leading steel plate, a following steel plate, and a welding trolley for welding them to make them continuous, showing a state where the welding trolley starts running. FIG. 5 is a block diagram showing a positional relationship among a leading steel plate, a succeeding steel plate, and a welding bogie for welding them to make them continuous, in a state where the traveling speed of the welding bogie has reached the moving speed of the preceding steel plate. Is shown. FIG. 6 is a block diagram showing a positional relationship among a preceding steel plate, a succeeding steel plate, and a welding bogie for welding them to make them continuous, wherein the welding bogie travels at the same speed as the moving speed of the preceding steel plate; This shows a state in which the succeeding steel sheet matches the moving speed of the preceding steel sheet. FIG. 7 is a block diagram showing a positional relationship among a leading steel plate, a trailing steel plate, and a welding bogie for welding them to make them continuous, wherein the welding bogie, the leading steel plate, and the following steel plate are:
This shows a state of being integrally connected by the clamp. FIG. 8 is a block diagram showing a positional relationship among a preceding steel sheet, a succeeding steel sheet, and a welding trolley for welding the steel sheets to make them continuous, in which the preceding steel sheet and the following steel sheet are welded to make them continuous. Indicates a state in which FIG. 9 is a block diagram showing an outline of a conventional speed control system for a welding bogie. FIG. 10 shows a welding cart as shown in FIG.
FIG. 4 is a block diagram showing a cause of tension occurring in a preceding and succeeding steel plate in a state where a preceding steel plate and a following steel plate are integrally connected by a clamp. FIG. 11 shows the target speed and actual speed (SPEED) of the welding bogie, the tension of the succeeding steel plate (TENSION 1), and the tension of the preceding steel plate when the conventional traveling speed device shown in FIG. 9 is used.
It is a graph which shows (TENSION 2). [Description of Signs] 11: Subtractor 15: Multiplier 16: Adder 20d: Mode
20 m: electric motor 41: pulse generator 51: laser Doppler type plate speedometer 52: pulse generator 53: steel plate detector

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B21B 15/00 B21B 1/26 B23K 9/025

Claims (1)

(57) [Claim 1] While holding the tail end of the preceding steel plate moving and the tip of the succeeding steel plate, it travels with the steel plate using welding means and welds the tail end and the tip. In the traveling control device for the welding bogie, the speed of the welding bogie is controlled until the welding bogie holds the tail end of the preceding steel plate and the tip of the succeeding steel plate, and after holding, the traveling resistance compensation corresponding to the traveling resistance of the welding bogie is performed. A travel control device for a welding bogie, wherein a travel control method of the welding bogie is switched so as to output a torque and an acceleration / deceleration compensation torque corresponding to acceleration / deceleration of inertia of the welding bogie by a change in a speed target value.