EP0054535B1 - Device for the surveillance of a mill train or a water mill - Google Patents

Description

The invention relates to a device for monitoring rolling mills and cooling lines, in particular for the production of bars or wires. In the case of partially or fully continuous rolling mills for the production of long products, such as profiles, bars or wires, the throughput is increased with increasing operating weights and higher rolling speeds. A process control is provided at rolling speeds of, for example, 30 to 80 m / s, since such rolling speeds already exceed the responsiveness of the control personnel. With the known process controls, which work using process computers, a number of essential operating parameters for the rolling, in particular the speed specification of the drive, the control of separating units or scissors, the loop control and the sequence control, are automatically monitored and controlled. Such computer-controlled rolling mills, however, require an unobstructed pass line for the rolling stock. If obstacles, such as material residues and deposits from the rolling stock in rolling mills and water accumulations in cooling sections, occur in the pass line, collisions with the incoming rod tip of the rolling stock can occur at high operating speeds, which results in malfunctions, in particular incorrect rolling, which result in addition to a material committee can also result in damage to the rolling mills. Due to the time required to correct the malfunctions, there is a reduction in the utilization of the rolling mills. As a result of the high dynamic loads when bars hit obstacles at high speed, damage to the rolling and transport units can occur.

With the current rolling mills and cooling lines, a check for freedom from obstacles on the rolling mills is generally only carried out when the rolling mill is converted or when the rolling malfunction has already occurred. It is not possible to check the continuous line during rolling operation with the known measures due to the short cycle times of often less than 5 s.

The invention aims to provide a device of the type mentioned at the beginning with which the automatic testing of the pass line in the time sections between successive rolling operations can be carried out at the speed required for this. To achieve this object, the invention consists essentially in that at least one light source, for example a Ne-He laser, is arranged at one end of a rolling mill or cooling section in the pass line of the material to be rolled and out of the pass line so that at least a light-sensitive sensor, for example a Si photodiode, is arranged at the other end of the rolling mill or cooling section in the through-line of the material to be rolled and can be pivoted out of it, and that the signals of the light-sensitive sensor of an evaluation circuit and a control unit for the rolling mill or cooling section are supplied, and that the light source and the sensor is connected to a pivot drive. Because the pass line is optoelectronically checked, process computers can be used to quickly check for obstacles in the relatively curved time interval between successive rolling operations. In order to avoid a collision of the optoelectronic measuring devices with the material to be rolled, starting from known devices according to GB-A-932 587, from which the features of the preamble of claim 1 are known, the light source and light-sensitive sensor can each be pivoted and arranged for the measuring process swung into the pass line and swung out of the pass line after the measurement. The light source is formed, for example, by a Ne-He laser with an output of <10 mW. Such a laser is not significantly influenced by the industrial atmosphere or the ambient light and can be focused very precisely. As a light-sensitive sensor, for example, an Si photodiode can be used, which is distinguished by low response times of, for example, 10 ^second The signals from the light-sensitive sensor can either be evaluated with the process computer available for controlling the process or with a separate evaluation circuit and used for controlling the drive.

For determining the point in time suitable for pivoting the light source and light-sensitive sensor, at least one additional material detector, such as, for. B. a photocell, a light barrier or inductive or capacitive proximity switch, arranged before the inlet and / or after the outlet of the rolling mill or cooling section to be monitored, the signals of which are fed to the control unit, the control device having a drive for pivoting the light source and Sensor can be connected. With such an arrangement, the possible faults can be recognized in good time and the necessary control measures can be taken in good time. If, for example, the measurement of the through line shows that there is no obstacle, no additional control measures are necessary. In the event that an obstacle is found in the pass line, the conveyance of further material can be carried out until it is removed of the obstacle can be stopped, provided the raw material has not yet been fed into the production line. However, if it is signaled by the additional material detector that the primary material has already been fed into the production line, the control device can, for example, direct measures for the removal of obstacles according to claim 6, provided there is still sufficient time for this. If a replacement product route is available, the collision of the material that has entered the production line could be prevented by repositioning a switch. If such a path is not available, so that these measures would be too late to prevent a collision, a separating unit can still be activated as a last resort, so that the rolling stock is removed from the rolling train before hitting the obstacle. For these purposes, the training is preferably such that the control unit in a known manner with the drive of the rolling mill or cooling section and / or with at least one sub-assembly, such as. B. a chopper, and / or at least one switch to an alternative path, is connected before the inlet of the rolling mill or cooling section to be monitored.

The light source is advantageously arranged at the outlet end of the rolling mill to be monitored, which creates the possibility that the beam cone of the light source is focused according to the caliber row of the rolling mill. Such focusing of the light source offers the greatest security for the detection of obstacles in the rolling mill or the cooling section.

• Figur 1 ein Blockschaltbild einer konventionellen rechnergesteuerten Walzstraße,
• Figur 2 eine vergrößerte Detailansicht der Figur 1 mit der erfindungsgemäßen Überwachungseinrichtung und
• Figur 3 eine weitere Ausgestaltung der erfindungsgemäßen Überwachungseinrichtung.

The invention is explained below with reference to an embodiment shown in the drawing. In this show:

• FIG. 1 shows a block diagram of a conventional computer-controlled rolling mill,
• Figure 2 is an enlarged detail view of Figure 1 with the monitoring device according to the invention and
• Figure 3 shows a further embodiment of the monitoring device according to the invention.

In Fig. 1, the billet task is denoted by t. 2 shows a walking beam furnace which can serve as a material buffer. 3 denotes a two-core VorstraBe, to which intermediate streets 4 connect. Following the intermediate streets 4, switches 5 are provided for the distribution of the rolling stock. 6 is used to refer to garret reels, while the material is fed to winding layers 8 for the formation of the bundle via the finishing lines designated 7. With 9 a coil transport device is designated. The process control is indicated schematically in FIG. 1, 10 being the conductance calculator for the first wire and 11 being the conductance calculator for the second wire. A corresponding process periphery 13 is also provided. Furthermore, a material tracking computer 14 together with the associated process periphery 15 is included in the process control. Coupling lines for connecting the individual computers or peripherals are indicated at 16.

The monitoring device is now included in such a system, as shown in FIG. 2. The components that are unchanged from FIG. 1 are designated with the same reference numerals, a hook path 17 for the removal of the bundles for testing, pressing, binding, sorting and unloading being visible in the enlarged representation.

The monitoring device has a measuring device consisting of a light source 18 and a light-sensitive sensor 19. The light source 18 is in this case formed by a Ne-He laser and the light-sensitive sensor by an Si photodiode. Transmitter and receiver 18 and 19 are pivotally mounted about an axis 21 ligating outside the respective pass line 20 and equipped with a pivot drive 22. hen.

An enlarged representation of such a monitoring device can be seen in FIG. The Ne-He laser 18 is focused on a divergence a of <0.08 mrad, this angle corresponding, for example, to the caliber series of the rolling mill 4. 3, both the transmitter 18 and the receiver 19 are pivoted into the pass line 20 and the signal emitted by the laser is made available by the Si photodiode 19 to an evaluation circuit 23. Depending on whether the transmitter is arranged at the outlet end 24 of the rolling mill 4 or at the inlet end 25 of the same rolling mill 4, a signal line 26 or 27 is used for the evaluation circuit 23. The evaluation circuit 23 is connected to the central control and control unit 29 via the line 28. A material detector 30 is arranged in front of the inlet end 25. The material detector arranged after the outlet end 24 is. designated by 31, the signals of the material detectors 30, 31 being connected to the central control and control unit 29 via signal lines 32.

The swivel drive 22 of the transmitter or receiver is actuated by lines 33 from the central control and control unit 29. If the material detector 30 indicates that the rod end has passed the location of this detector, the pivoting of the receiver 19 into the pass line 20 can be initiated after a corresponding safety time. At the same time, time monitoring for the next staff can begin. If the material detector 31 also signals the passage of the rod end, the central control and control unit 29 causes the transmitter 18 to pivot into the pass line 20. The correspondingly focused signal is then sent out and the evaluation is carried out. Immediately after the measurement process, the transmitter 18 and receiver 19 are pivoted back into their starting position outside the pass line 20.

If the evaluation circuit 23 signals that the pass line is free, the central control and control unit and a control of the conveying unit 34 for the primary material in turn release any locking which may have previously been released and initiate the discharge of the next rolled primary material.

If the pass line is blocked, the raw material control 34 remains locked according to a command from the evaluation circuit 23 and the central control and control unit 29 until the obstacle is removed. If there is already a signal from the material detector 30 at such a point in time, this means that the following pre-rolled material is already entering. In the case shown in FIG. 3, an alternative route is no longer available and an obstacle removal also appears too late. In this case, a chopping shear 36 is put into operation via the control line 35 via the central control and control unit 29, which cuts the rolling stock into pieces before it hits the obstacle and removes it from the rolling train. Such a measure can then be omitted. if a switch enables a diversion to a replacement product route or timely removal of obstacles.

The laser used is calibrated when the rolling mill is empty. In operation, when a beam intensity of at least 90% is received, the rolling mill is assumed to be free of obstacles. The control measures can be carried out in a hard-wired manner in the computer. They can also be freely programmed, which is more flexible if e.g. B. the production plant is changed or further control measures are to be included.

2, the monitoring device is arranged only at the intermediate and finished streets. A check is not absolutely necessary in Vorstraße 3, which is still used with larger cross sections. The interconnection of rolling mills can be done individually or in combination. If these rolling mills follow one another directly, practically only the combined release is possible.

Depending on the beam power of the transmitter, rolling mills over lengths of up to 300 m can be easily monitored. In addition to the precise beam bundling, the use of a Ne-He laser has the advantage that such a transmitter operates unaffected by the industrial atmosphere, such as oil mist and water vapor, and is not disturbed by the ambient light.

Claims (6)

1. Monitoring equipment for rod or wire rolling mills or for cooling trains of mill trains comprising opto-electric sensors which are connected to an interpreting circuit and to a control unit for the mill train or the cooling train, resp., characterised in that at least one light source (18), for example a Ne-He-Laser, is arranged at one end of a mill train or cooling train, resp., for being swivelled into and out of the travelling line (20) of the material to be rolled, that at least one photosensitive sensor (19), for example a Si-photo diode, is arranged at the other end of the mill train (4, 7) or of the cooling train, resp., for being swivelled into and out of the travelling line (20) of the material to be rolled, and that the light source (18) and the sensor (19) are connected with a pivotal drive (22).

2. Monitoring equipment as claim 1 characterised in that at least one additional detector (30, 31) for the material to be rolled, for example a photocell, a light barrier or inductive or capacitive proximity switch, is arranged before the supply end (25) and/or behind the discharge end (34) of the mill train (4, 7) or of the cooling train, resp., to be monitored, the signals of said detector being supplied to a control unit (29).

3. Monitoring equipment as claimed in claim 2, characterised in that the control unit (29) is in connection with the pivotal drive (22) for swivelling the light source (18) and the sensor (19).

4. Monitoring equipment as claimed in claim 1, 2 or 3, characterised in that the control unit (29) is, in a manner known per se, connected with the drive means of the mill train (4, 7) or the cooling train, resp., and/or with at least one driving aggregate, for example a chopping machine (36), and/or at least one diverter (5) to an alternate path before the supply end (25) of the mill train (4,7) or cooling train to be monitoring.

5. Monitoring equipment as claimed in any of claims 1 to 4, characterized in that the light source (18) is arranged at the discharge end (24) of the mill train to be monitored, the radiation cone of the light source being preferably focussed in accordance with the sequence of passes of the mill train..

6. Monitoring equipment as claimed in any one of claims 1 to 5, characterised in that the control unit (29) is in connection with devices for the removal of obstacles, such as devices for blowing free the water cooling trains, and/or for swivelling out guide means.

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