JPS61209701A - Blooming method - Google Patents

Abstract

PURPOSE:To prevent the damage of a rolling mill by opening a gap of rolling rolls immediately before biting a slab and returning the roll gap to a set value by detecting a rolling reaction at the moment when the slab is bitten. CONSTITUTION:Load cells 13, 14 are provided respectively to the bearing parts of table rolls 1, 1a placed at the inlet and outlet sides. A load cell 15 for detecting a rolling reaction is provided to a mill housing 3 and is connected to a signal converter 18. The load cells 13, 14 are connected to a host control unit 20 respectively through signal converters 16, 17. Immediately before a slab 2 is bitten by rolling rolls 4, 5, a roll gap is opened by several percents through a signal of load cell 13. Further, the roll gap is returned to a set value, through the load cell 15 and the control unit 20, at the moment when the slab 2 is bitten into the rolls 4, 5. In this way, a mill is kept free from an impact load and is therefor prevented from being damaged.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for blooming steel materials, etc. using a blooming mill.

<Prior Art> Conventionally, when a slab of steel material or the like is rolled in a blooming mill, the rolling mill is usually controlled by detecting the rolling load or the load current of the electric motor that drives the rolling rolls.

As shown in Figure 1M2, which represents the concept of such a conventional 9-blubber rolling mill, a slab 2 is conveyed by a table roller 1, and the gap between an upper roll 4 and a lower roll 5 incorporated in a mill housing 3 is Screw down according to plate thickness 5--6
Rolling is performed by holding the upper and lower rolls 4.5 at optimal positions. During this rolling, the worker monitors the rolling reaction force detected by the load cell 7 provided in the mill housing 3 using an indicator 8, or
The load current of the drive motors 9, 1-0 is read from indicators 11 and 12, and the direction of load application is controlled 20-.

Since the blooming mill is used under harsh conditions, excessive stress is generated in the mill housing 3 and the reduction screw 6.
This is a major cause of damage. Therefore, in the conventional blooming rolling method as described above, in order to prevent damage to the reduction screw 6 and the mil-no-using 3 due to excessive load, the reduction amount is reduced and the worker uses the indicator 8.11.12. The reduction screw 6 is adjusted while checking the value of .

<Problems to be Solved by the Invention> In the conventional blooming rolling method, the rolling amount is made smaller than necessary in order to avoid damage to the rolling knee and the housing, resulting in a low production volume. When an increase in volume is required, the operator relies on manual control, which tends to result in harsh operation and overload, especially when the slab is caught in the rolling rolls, causing the rolling mill to overload. causing damage.

The present invention eliminates the drawbacks of such conventional rolling methods,
It is an object of the present invention to provide a rational blooming method that can limit overload and prevent damage to a rolling mill.

Means for Solving the Problems> The blooming rolling method of the present invention detects the tip of the slab by a detector provided on the table roller bearing immediately before biting the rolling roll slab of the blooming mill, This detection signal operates the reduction screw to open the gap between the rolling rolls to a predetermined setting value, and then detects the rolling reaction force signal when the tip of the slab enters the rolling roll. The invention is characterized in that the reduction screw is operated in response to a signal to return the gap between the rolling rolls to the predetermined set value.

Effect> When the tip of the slab reaches the table row 2 equipped with a detector, this is detected, and based on the detection signal, a preset roll gap is instantaneously opened by, for example, several percent of the set value. This prevents an excessive impact load from being applied to the mill housing and the reduction screw when the slab is jammed. Next, the rolling reaction force generated when the slab is bitten by the rolling roll is detected, and the roll gap is returned to a predetermined setting value based on this signal.
Rolling to a predetermined thickness is performed.

<Example> As shown in FIG. 1, which shows the concept of an example of the method of the present invention, a slab 2 is conveyed on a table roller 1, and between an upper roll 4 and a lower roll 5...; A load cell 13 is provided in the bearing part of the table roller 1 on the entry side of the blooming mill in which rolling is performed by biting the table roller 1.
Further, a load cell 14 is provided at the bearing portion of the table roller 1a on the exit side.

Further, the mill housing 3 is provided with a load cell 15 for detecting rolling reaction force. And these load cells 1
Signal converters 16, 17 and 18 for converting the detection signals are respectively connected to 3, 14 and 15, and the signals from these signal converters 16, 17 and 18 are inputted to drive the drive motor of the reduction screw 6. A main controller 20 is provided that issues controller 191C control signals. Note that the reduction screw 6 has a drive motor 21 that is controlled by the drive motor controller 19.

During rolling work, just before the slab 2 is bitten between the upper and lower rolls 4.5, when its tip reaches the table roller 1, the roll gap between the rolls 4.5, which was preset by the signal from the load cell 13, is momentarily open several percent of the set value. That is, the load cell 13 detects that the tip of the slab 2 has come onto the table roller 1.
The output signal is converted by the signal converter 16 and inputted to the main controller 20, and the main controller 20 gives a control signal to the drive motor controller 19, which controls the drive motor 21 in the direction of opening the roll gap. Rotate. Next, when the slab 2 is caught between the rolls 4.5, the load cell 15 detects this rolling reaction force, and the detection signal is converted by the converter 18 and input to the main controller 20. A control signal is issued to the drive motor controller 19, and the drive motor 21 is driven to return the roll gap to its original setting value and enter steady operation.

Since the blooming mill performs repeated (reciprocating) rolling, when the first pass from right to left in the figure is completed as described above, the second pass from left to right in the figure is completed. Rolling is performed.

At this time as well, the upper and lower rolls 4.5 of slab 2 are
When the tip of the slab 2 comes on top of the table roller 1a before being caught in the gap, the load cell 14 detects this and similarly sends a signal to the main controller 20 via the signal converter 17 to set it. When the roll gap that had been set opens several percent of the set value and the slab 2 is caught between the rolls 4.5, the load cell 15 detects this, and the roll gap is returned to its original state and steady rolling is performed in the same way as above. .

How is it possible to open the roll gap momentarily just before the slab bites in each pass, so that the rolling operation can be carried out without causing any shock loads or damage to the mill housing 3 and the reduction screw 6? obtain.

<Effects of the Invention> According to the method of the present invention, the impact load applied to the mill housing and the reduction screw when the slab is bitten in the blooming mill is avoided, and the mill housing and the reduction screw are not damaged, resulting in high efficiency and rationality. It is possible to carry out various rolling operations.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram of an embodiment of a blooming mill that implements the blooming method of the present invention, and FIG. 2 is a conceptual diagram of a conventional blooming mill. In the drawing, 1+1a is a table roller, 2 is a slab, 3 is a mill housing, 4 and 5 are rolls, 6 is a reduction screw, 13 to 15 are load cells, 16 to 18 are signal converters,
19 is a drive motor controller, 20 is a main control device,
21 is a drive motor.

Claims (1)

[Claims] Immediately before the slab is bitten by the rolling rolls of the blooming mill, the tip of the slab is detected by a detector installed in the table roller bearing, and this detection signal is used to operate the reduction screw to adjust the gap of the rolling roll to a predetermined level. The gap of the rolling roll is adjusted to the predetermined setting value by detecting a signal of rolling reaction force when the tip of the slab enters the rolling roll and operating the rolling screw based on this detection signal. A blooming rolling method characterized by rolling back.