JPH0243562B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention involves rolling a material to be rolled by stacking three work rolls and passing the material to be rolled in a meandering manner through each rolling pass between the upper and lower work rolls. The present invention relates to a rolling control device in a one-stand multi-pass rolling mill.

[Technical background of the invention and its problems]

Conventionally, general rolling mills have been configured for one stand and one pass rolling. However, in this type of rolling mill, the rolling reduction per stand is about 40% at most, so in a Dandem rolling mill, it is necessary to perform high reduction rolling by increasing the number of stands.
This caused an increase in cost and space. However, recently, as described in, for example, Japanese Patent Application Laid-Open No. 56-17105 (Japanese Patent Application No. 54-91478), one-stand multi-pass rolling mills aimed at saving cost and space have attracted attention. This is achieved by installing three or more work rolls, where there were only two in the past, passing the material to be rolled in a meandering manner between each work roll, and rolling the work roll while sequentially varying the speed of each work roll according to the rolling reduction ratio. This enables stand multi-pass rolling. If such a one-stand multi-pass rolling mill is used, high reduction rolling with a rolling reduction rate of 70% per stand is possible.

However, in such a one-stand multi-pass rolling mill, if the work rolls continue to rotate in a state where there is no material to be rolled between the work rolls due to plate breakage, tail drop, etc., the work rolls may They come into direct contact with each other at different circumferential speeds.
As a result, mechanical overload was applied to the roll surface, roll shaft, gear, etc., which could lead to damage.

[Purpose of the invention]

The present invention has been made to solve the above-mentioned problems.
The purpose of the present invention is to provide a rolling control device that prevents accidents such as work rolls coming into direct contact with each other at different circumferential speeds due to tail drop, causing mechanical damage to the roll surfaces, roll shafts, gears, and other parts of the rolling mill. shall be.

[Summary of the invention]

In order to achieve this objective, the present invention predicts the timing at which the material to be rolled passes through each rolling pass, and changes the upper and lower work rolls of each rolling pass prior to the predicted timing at which the material to be rolled ends at the end of each rolling pass. At the same time, a break in the material to be rolled is detected, and when this plate breakage is detected, the upper and lower work rolls on the path downstream of the plate breakage are changed from a different speed operation state to a constant speed operation state. I am trying to move to the state.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 is a side view of a one-stand multi-pass rolling mill, for example a one-stand multi-pass rolling mill, which is controlled by the present invention.

In FIG. 1, 1 is a first work roll, 2 is a second work roll, 3 is a third work roll, and 4 is a fourth work roll, and these first to fourth work rolls 1 to 4 are on the lower side. They are stacked and placed between a backing roll 5 and an upper backing roll 6. The material to be rolled A is rolled as it passes between the work rolls 1 and 2, 2 and 3, and 3 and 4 in a meandering manner in the direction indicated by the arrow. In this way, three rolling passes are performed per stand, which will hereinafter be referred to as the first pass, second pass, and third pass in order from the bottom. 1st pass and 2nd pass
A pull-out roll 7 is installed between each pass, and a pull-out roll 8 is installed between the second pass and the third pass, and serves to pull out the material A to be rolled between each pass. Note that when there is no need to draw out the material to be rolled between each pass, the rolling material is configured to be rolled in the state shown by the first broken line. Further, a tension meter roll 9 for detecting tensile force is installed on the input side of the first pass, and a tension meter roll 10 is installed on the output side of the third pass.

FIG. 2 is a configuration diagram of a rolling control device related to the rolling mill. In the figure, 20 is a tracking device on the first path input side, and this tracking device 20
is for tracking the tail end position of the material to be rolled A at the entrance side of the first pass, and is a function of the rotation speed detector (for example, pulse generator) 21 connected to the tension meter roll 9. By inputting the output signal and the position signal 22 of the tension meter roll 9 and counting the number of pulses _P1 generated by the pulse generator 21, the tail end position of the material to be rolled A is calculated and the tail end position signal 23 is calculated. is sent to the first and second roll constant velocity command device 24. The first and second roll constant velocity command devices 24 receive the tail end position signal 23, and when it is detected that the tail end position has reached a pre-specified position before the first pass, the first and second roll uniform velocity command devices 24 A two-roll constant speed command 25 is sent to the speed setting device 26. Furthermore, this first
The detected tension 28 of the tension meter 27 attached to the tension meter roll 9 is inputted to the second roll constant velocity command device 24, and even when the detected tension 28 shows zero tension due to bottom drop or plate breakage, It has a function of sending out the first and second constant velocity commands 25 to the speed setting device 26. In addition to the first and second constant speed commands 25, the speed setting device 26 receives second and second roll constant speed commands 25, which are output signals of the second and third roll constant speed command devices 30.
The third roll constant speed command 31 and the third and fourth roll constant speed commands 32 which are the output signals of the third and fourth roll constant speed command devices 32
A roll constant speed command 33 is input. Here, the second and third roll constant velocity command devices 30 are configured to detect tension 35 of a tension meter 34 attached to the pull-out roll 7.
is input, and when the detected tension 35 shows zero tension due to tailing or plate breakage, the second and third roll constant speed commands 31 are sent to the speed setting device 26. Further, the third and fourth roll constant speed commands 32 are based on the detected tension 37 of the tension meter 36 attached to the pull-out roll 8.
is input, and when the detected tension 37 shows zero tension due to tail drop or plate breakage, the third and fourth roll constant speed commands 33 are sent to the speed setting device 26. The speed setting device 26 outputs peripheral speed target value signals for each of the work rolls 1 to 4, and the speed setting device 26 outputs a peripheral speed target value signal for each of the work rolls 1 to 4.
5, 31, 33, each command 25, 31, 3
The circumferential speed target values V ₁ , V 2 , V 3 , V ₄ of each work roll 1 , ₂ , ₃ , 4 according to the speed control device 40 ,
41, 42, and 43. The speed control devices 40, 41, 42, 43 control the rotational speed of each work roll drive motor 44, 45, 46, 47. Further, a detector (for example, a load cell) 50 is attached to the upper backing roll 6 for detecting plate breakage or tail-off, and the output of this load cell 51 is transmitted to the constant velocity command device 24, 30,
32, and backs up the detection of bottom-out and plate breakage.

The operation of the rolling control device configured as above will be explained. First, the operation of this embodiment will be explained through the process in which the material to be rolled A goes through its tail.

As the material to be rolled A is rolled through the first to third passes, the first pass entry side tracking device 20 uses the pulse gear connected to the tension meter roll 9 as a reference, using the position signal 22 of the tension meter roll 9 as a reference. By counting the number of pulses _P1 generated by the generator 21, the tail end position of the material to be rolled A is calculated, and a tail end position signal 23 is given to the first and second roll constant velocity command devices 24. Then, the first and second roll constant velocity command devices 24 set the first and second roll constant velocity commands 25 at the time when it is detected that the tail end position has reached a predetermined position before the first pass. device 26. In addition, the first and second constant velocity command devices 2
4 provides the first and second roll constant velocity commands 25 to the speed setting device 26 even when the tension 28 detected by the tension meter 27 is zero tension due to the upstream end or plate breakage. The speed setting device 26 inputting the first and second roll uniform velocity commands 25 sets the ratio of the circumferential speed target values V ₁ and V ₂ of the work rolls 1 and 2 to 1, and 1 peripheral speed target value V ₁ ,
The peripheral speed target value V ₂ of the second work roll 2, the peripheral speed target value V 3 of the third work roll ₃ , and the peripheral speed target value V ₄ of the fourth work roll 4 are controlled by each speed control device 41,
Give to 42, 43, 44. Then, each speed control device 41, 42, 43, 44 controls each work roll drive motor 44, 45, 46, 47 to each peripheral speed target value.
Since they are driven according to V ₁ , V ₂ , V ₃ , and V ₄ , the first work roll 1 and the second work roll 2 shift from a different speed rolling state to a constant speed rolling state. As a result, when the tail end position of the material to be rolled A passes between the first work roll 1 and the second work roll 2, the first and second work rolls 1 and 2 rotate at the same speed, so that the tail end position of the material to be rolled A passes between the first work roll 1 and the second work roll 2. This can prevent the upper and lower work rolls 2 and 1 of the first pass from coming into contact at different speeds. Note that even if the above-mentioned change in the circumferential speed target value necessary for transitioning from a different speed rolling state to a constant speed rolling state is performed in steps,
It may be performed with a certain inclination, or it may be performed according to a prespecified pattern.

Next, the second and third roll constant velocity command devices 30 detect that the tension 35 detected by the tension meter 34 has become zero due to the bottom of the first pass or a plate breakage between the first and second passes. At that point, a second and third roll constant speed command 31 is given to the speed setting device 26. The speed setting device 26 receives the second and third roll constant velocity commands 31, and sets the circumferential speed target value of the work rolls 2 and 3.
The ratio of V ₂ and V ₃ is set to 1, and each predetermined peripheral speed target value V ₁ , V ₂ , V ₃ , V ₄ is set to each speed control device 40 , 4 .
Give to 1, 42, 43. As a result, the upper and lower work rolls 3 and 2 of the second pass rotate at the same speed, and after the tail end position or break position has passed the upper and lower work rolls 3 and 2 of the second pass, the upper and lower work rolls 3 and 2
can prevent contact at different speeds.

Furthermore, the third and fourth roll uniform velocity command devices 32
When it is detected that the tension 37 detected by the tension meter 36 becomes zero due to the end of the second pass or a plate breakage between the second and third passes, the third and fourth roll constant velocity commands 33 are issued. to the speed setting device. Third,
The speed control device 26 that received the fourth roll uniform velocity command 33 sets the ratio of the circumferential velocity target values V ₃ and V 4 of the work rolls 3 and ₄ for the third pass of the work to 1, and The speed target values V ₁ , V ₂ , V ₃ , V ₄ are given to each speed control device 40 , 41 , 42 , 43 . This results in
Similarly to the above, it is possible to prevent the upper and lower work rolls 4 and 3 of the third pass from coming into contact at different speeds.

Note that the above-mentioned constant speed command devices 24, 30, 32
The load cell output 51 from the load cell 50 is inputted to the load cell 50, which is used as a backup signal for detecting bottom drop and plate breakage by taking advantage of the fact that the force applied to the load cell 50 changes greatly when the bottom falls off or the plate breaks. , constant velocity command devices 24, 30, 32
This is to ensure that the operation is performed reliably.

Therefore, in this embodiment, work rolls 1 to 4 are
In a one-stand multi-pass rolling mill in which the rolled material A is stacked up and rolled in a meandering manner between each work roll, and the speed of each work roll 1 to 4 is sequentially varied according to the rolling reduction ratio, the rolled material A is rolled. is configured to predict the timing at which the roll ends each pass, and to shift the upper and lower work rolls 1 to 4 of each pass from a different speed operation state to a constant speed operation state prior to the predicted end removal timing of each pass, In addition, when plate breakage is detected, the upper and lower work rolls on the downstream path from the plate breakage point are configured to shift from different speed operation to constant speed operation, so there is no risk of rolls that may come into contact with each other when work rolls 1 to 4 come into contact with each other. Mechanical damage to the surface, roll shaft, gear, and other parts of the rolling mill can be prevented.

In the above embodiment, all of the work rolls 1 to 4 are driven by electric motors 44 to 47, but the first work roll 1 may be an idling roll (idling wheel). In addition, the tension gauges 34 and 36 in FIG. 2 cannot be used in the rolling state shown by the broken line in FIG. , by detecting plate breakage and bottom removal.
It is possible to perform the same function as shown in the figure. Furthermore, it goes without saying that the above embodiment can also be applied to a rolling mill with four or more passes per stand.

〔Effect of the invention〕

As described above, in the present invention, when there is no material to be rolled between adjacent work rolls due to tail drop, plate breakage, etc. in a one-stand multi-pass rolling mill, and there is a risk that the work rolls may come into direct contact with each other,
Since it is configured to quickly shift from a different speed operating state to a constant speed operating state, it is possible to prevent mechanical damage to the roll surfaces, roll shafts, gears, and other parts of the rolling mill that may occur during contact.

[Brief explanation of drawings]

FIG. 1 is a side view of a one-stand multi-pass rolling mill to be controlled by the present invention, and FIG. 2 is a block diagram of a rolling control device showing one embodiment of the present invention. 1 to 4...Work roll, 5,6...Backup roll,
7, 8...Drawer roll, 9, 10...Tension meter roll, 20...First pass entrance side traversing device, 21...Pulse generator, 24...
First and second roll constant velocity command devices, 26... Speed setting device, 27, 34, 36... Tension meter, 30...
...Second and third roll constant speed command devices, 32...Third and fourth roll constant speed command devices, 40 to 43...
Speed control device, 44-47... Work roll drive motor, A... Material to be rolled.

Claims (1)

[Claims] 1. A method having three work rolls, passing the material to be rolled in a meandering manner through each rolling pass between adjacent work rolls, and varying the speed of the work rolls in each rolling pass sequentially according to the rolling reduction ratio. In a one-stand multi-pass rolling mill that performs tightening and rolling, a tracking device that calculates and predicts the tailing timing of each rolling pass based on a detection signal of a first detection means that detects a tail end position of the material to be rolled. a second detecting means for detecting the timing of breakage and tailing of the material to be rolled on the entrance side of the rolling mill and between each rolling pass; A timing generating device that generates a timing for shifting the upper and lower work rolls of each rolling pass from a different speed operation state to a constant speed operation state prior to the tail end position of the rolled material or the tail end timing of a fracture location, and this timing generation device. A one-stand multi-pass rolling mill comprising: a speed setting device that sets a speed target value for shifting the upper and lower work rolls of each rolling pass to a constant speed operation state according to the timing of the device. rolling control device. 2. In the device according to claim 1,
The timing generating device is configured to generate a timing for shifting the upper and lower work rolls of each rolling pass from a different speed operating state to a constant speed operating state, prior to the tail end timing of each rolling pass predicted by the tracking device. A rolling control device for a one-stand multi-pass rolling mill, characterized in that: 3. In the device according to claim 1,
The timing generating device determines the timing for shifting the upper and lower work rolls of each rolling pass located downstream of the fracture point from a different speed operation state to a constant speed operation state based on the detection signal of the second detection means. 1. A rolling control device for a one-stand multi-pass rolling mill, characterized in that: