JPS6361084B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for controlling the speed of tables disposed on the entry and exit sides of a reversible rolling mill, and in particular, to a method for controlling the speed of tables disposed on the entry and exit sides of a reversible rolling mill, and in particular, for achieving stable rolling and improving rolling efficiency. Regarding those that speed control the table to improve.

[Conventional technology]

The main control device in the reversible rolling mill controls the reversible rolling mill and the front and rear tables of the reversible rolling mill. The equipment configuration is shown in Figure 1. In the figure,
1 is work roll 1a and backup roll 1b
2 is an entry table of the reversible rolling mill 1, 3 is an exit table of the reversible rolling mill 1, and 4 is an exit table of the reversible rolling mill 1.
5 is a reduction gear that connects the input and output tables 2 and 3 with the drive motor 6; 6 is the drive motor for the input and output tables; and 7 is this motor. 6 is a thyristor control device that operates the reversible rolling mill 1;
70 is a thyristor control device that operates this electric motor 60, and 8 is a master control device that provides a reference speed signal to the thyristor control devices 7 and 70.

In Fig. 1, the rolled material 4 is rolled in the normal direction of the arrow and stopped, and the kicking distance of the rolled material 4 is L.
It is becoming. If this kick-out distance L is too short, when rolling the rolled material 4 in the reverse direction of the next rolling,
Sufficient acceleration time and biting speed into the reversible rolling mill 1 cannot be obtained, resulting in unstable rolling. Moreover, if the kick-out distance L is too long, the time required for the rolled material 4 to be bitten by the reversible rolling mill 1 becomes long, and the rolling efficiency cannot be improved.

FIG. 2 diagrammatically represents the conventional control method, with the horizontal axis representing time and the vertical axis representing speed. In the figure, curve A shows the rolling speed of the reversible rolling mill 1, and curve B shows the table speed of the table 3. Point C indicates the point at which the rolling mill 1 kicks out the tail end of the rolled material 4 during rolling operation in the normal rotation direction, and the reversible rolling mill 1 and table 3 are determined by the capacity of the reversible rolling mill 1. The vehicle is accelerated or decelerated along the acceleration/deceleration rate α (m/sec ² ). At this time, the reversible rolling mill 1 and the input and output tables 2 and 3 are always operated in conjunction (hereinafter this state is referred to as mill follow), and the rolled material 4 is placed at a distance L from the center of the reversible rolling mill 1. Stop. Note that the speed acceleration/deceleration rate α is normally determined from Tables 2 and 3.
Since the deceleration rate is set to be greater than the slip limit of the rolled material 4, it stops at a distance of "distance L + slip amount".

On the other hand, for the next rolling in the normal rotation direction, setting of the rolling reduction amount of the reversible rolling mill 1 is started from the kicking point C of the rolled material 4 along the curve E, and the setting is completed at the point D after time Ts. Become. It is an optimal and efficient rolling method that the rolled material 4 is bitten into the reversible rolling mill 1 at this point D. Therefore, after the reversible rolling mill 1 and the input and output tables 2 and 3 are stopped, they are accelerated at the acceleration rate α by the mill follower after the timer To. At this time, if the distance of "distance L + amount of slippage" is short, the distance required for the biting speed of the next rolling cannot be obtained, and therefore the rolled material 4 will be biting at a slow speed, causing problems such as biting and stopping. Mechanical problems occur.
In addition, if the above-mentioned distance is long, a sufficient biting speed can be obtained, but on the other hand, the stopping time of the reversible rolling mill 1 T ₀
Because of the increase in the rolling time, the rolling time becomes longer and efficient rolling becomes impossible. In FIG. 2, the speed difference ΔV between the reversing rolling mill 1 and the table 3 indicates the difference between the speed of the work roll 1a of the reversing rolling mill and the speed of the table 3 due to the setting of the rolling reduction amount.

[Problem that the invention seeks to solve]

Conventional table speed control methods do not control the stopping position and stopping time of the kicked-out rolled material, so it may not be possible to obtain a sufficient distance to obtain the biting speed for the next rolling. However, there was a problem in that efficient rolling was not possible.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a table speed control method that allows stable and efficient rolling.

[Means for solving problems]

In the table speed control method according to the present invention, in order to stop the rolled material at a necessary distance to obtain the biting speed for the next rolling, Td time is The speed of the reversible rolling mill is maintained at the kick-off time, and then it is decelerated, and in order to match the timing of the next rolling bite and the completion of setting the reduction amount of the reversible rolling mill, the speed is stopped for Ta time after deceleration. This is what I did.

[Effect]

The table speed control method of the present invention enables stable and efficient rolling by controlling the speed based on Td and Ta determined by calculation.

[Embodiments of the invention]

An embodiment of the present invention will be described in detail below with reference to FIGS. 3 and 4.

FIG. 3 is a block diagram of a master control device to which the present invention is applied, and FIG. 4 is a diagram showing one embodiment of the present invention. The configuration of the reversible rolling mill and its peripheral equipment is the same as the conventional device shown in FIG. 1, so FIG. 3 shows only the configuration of the part corresponding to the main control device 8 in FIG. There is.

In FIG. 3, a reference speed signal 22 of the reversing rolling mill 1 and the front and rear tables 2, 3 is input to a tilt signal generator 11 that generates a tilt signal according to the acceleration/deceleration β of the reversing rolling mill 1 and the tables 2, 3. Ru. The output signal 23 is input to the roll diameter compensator 12 of the work roll 1a. The output signal 24 of the roll diameter compensator 12 becomes a speed reference signal of the reversing rolling mill 1. On the other hand, the output signal 23 of the inclination signal generator 11 is input to the roll diameter compensator 13 of the tables 2 and 3, and its output signal 25 becomes a speed reference signal of the exit table 3 when the reversible rolling mill 1 rotates forward. , after passing through the reduction compensator 14, the signal 26 becomes the velocity reference signal of the entry table 2. or,
When the reversible rolling mill 1 is in reverse rotation, the signal 25 becomes the speed reference signal of the input table 3, and the contact that turns ON and OFF during forward rotation and reverse rotation so that the signal 26 becomes the speed reference signal of the output table 3. It is switched by 50a and 50b.

15 is a logic holding device that is set by the bite signal 31 to close the contacts 15a ₁ to 15a ₄ and is reset by the kick signal 32 to open the contacts 15a ₁ to 15a ₃ and close the contact 15b; is set and closes the contact 16a,
A logic holding device 17 is reset by the bit signal 31, a storage device 18 stores the signal 25;
1 is a tilt signal generator that generates a tilt signal according to the acceleration/deceleration β of tables 2 and 3; 19 is a table selection circuit that outputs a signal input from the tilt signal generator 18 to contacts 15a ₄ or 15b; . 2
0 is a timer device that gives reset timing to the storage device 17, and 21 is time 3 of the timer device 20.
6 and gives a table start command 35.

Hereinafter, the speed control method of the present invention will be explained with reference to FIG. 3 with reference to FIG. 4.

During rolling, the logic holding device 15 outputs the biting signal 31.
is set, and signals 25 and 26 are output.
This serves as a speed reference signal for the input tables 3 and 2. That is, in this state, the contacts 50a,
15a ₁ to 15a ₄ are closed, and the slope signal generator 1
The output signal 25 of No. 3 is outputted as a velocity reference signal of the output table 3 via the contact 15a ₁ , and the output signal 26 of the reduction compensator 14 is outputted as the velocity reference signal of the input table 2 via the contact 15a ₂ .

On the other hand, the logic holding device 16 is in a reset state due to the bit signal 31.

When the tail end of the rolled material 4 is kicked out from the reversible rolling mill 1, the logic holding device 15 is reset by the kicking signal 32, and the signals 25 and 26 are "broken" because the contacts 15a ₁ and 15a ₂ are opened by the signal 33. becomes.

However, the reset of the logic holding device 15 closes the contact 15b. Since the storage device 17 stores the signal immediately before the contact 15a ₃ opens, that is, the kick-out signal 25, the kick-out signal is sent to the table selection circuit 19 via the tilt signal generator 18. It is supplied as a speed reference signal for the output table 3 via the contact 15b. This state continues for the time Td set in the timer 20 started by the kick-out signal 32.
This Td is calculated by the device 21 using the following equation (1).

Td = 1/βVo (VI ² /2 - Vo ² /2) ...(1) However, Vo: Kick-off speed (m/sec) VI: Biting speed of next rolling (m/sec) β: Table speed Acceleration/deceleration (m/sec ² )
So, when the friction coefficient between the table and the rolled material is μ, and the gravitational acceleration is g, β
The relationship is ≦μg.

The timer device 20 resets the storage device 17 after a time Td from the kick-off. The output signal 27 of the storage device 17 becomes zero, but the slope signal generator 18 supplies a slope signal 27 corresponding to the deceleration rate β to the table selection circuit 19, and the incoming table is decelerated as shown in FIG. Stop.

Here, equation (1) will be explained with reference to FIG. In FIG. 4, the area L of the hatched portion indicates the kick-out distance of the rolled material 4, and the area LI indicates the distance required to obtain the bite speed of the next rolling. That is,
Equation (1) sets the kicking distance L to L=LI, so after kicking out the rolled material 4, in order to obtain the kicking distance L, the time Td for maintaining the speed Vo at the time of kicking is determined.

Next, after the table 3 is stopped, the stopped state is continued for Ta time calculated by the device 21. Ta is calculated by the following equation (2).

Ta=Ts-(Td+Vo/β+VI/β)...(2) However, Ts: Time used to set the rolling reduction amount (sec) When Ta has elapsed, the device 21 sends the start signal 3.
5 is supplied to the logic holding device 16 and set. This closes the contact 16a to the slope signal generator 18.
A signal 26 is input to. In this state, the reversible rolling mill 1 is rotated in the reverse direction for the next rolling.
The specified speed has been reached. Therefore, the table selection circuit 19 connects the output of the slope signal generator 18 to the contact 15.
A speed reference signal for the table 3 is supplied through the terminal b, and the table 3 is accelerated in the reverse direction according to the acceleration/deceleration β, as shown in FIG.

Here, as shown in Fig. 4, the above equation (2) is used to match the point in time when the reduction amount setting is completed and the point in time when the rolled material 1 is accelerated in the reverse direction and bit into the reversible rolling mill at a predetermined speed. , the time Ta for which the rolled material 4 is kicked out and the rolled material 1 is kept waiting at the stopped position is determined.

Note that during rolling in the reverse direction, the contact 50b closes and the contact 50a opens, so the signal 25 is used as the speed reference signal of the entry table 2, and the signal 26 is
is output as a speed reference signal of the output table 3. Furthermore, in the above explanation, the speed control of the exit table 3 after kicking in rolling in the forward direction was described, but in rolling in the reverse direction, the table 2 becomes the exit table and the speed is controlled in the same way. .

FIG. 4 is a diagram showing the speed control method of the present invention. In the diagram of Fig. 4, A is the rolling mill speed;
B indicates the table speed, and the rolling mill speed A changes linearly from the point of kicking out to the biting speed in the opposite direction, and the table speed, that is, the rolling material speed B, is the speed Vo at the point of kicking out after being maintained for a time Td. It is decelerated to a stop at a deceleration β, stopped for a time Ta, and then accelerated to an acceleration β. Then, the times Td and Ta are determined so as to obtain the distance LI required for acceleration up to the bite speed VI of the next rolling, that is, the kick-out distance L.

[Effects of the Invention] As described above, according to the present invention, the tail end of the rolled material is kicked out from the reversible rolling mill in order to stop the rolled material at the necessary distance to obtain the biting speed for the next rolling. From the time when the Td time is reached, the table speed shall be maintained at the kicking speed, and in order to match the timing of the biting of the next rolling and the completion of setting the rolling reduction amount of the reversible rolling mill, after deceleration, time
Since Ta is stopped, the reversible rolling mill becomes stable.
And it can be driven efficiently.

[Brief explanation of drawings]

Fig. 1 is a block diagram of equipment controlled by the main control device, Fig. 2 is a diagram of a conventional control system, Fig. 3 is a block diagram of the main control device according to the present invention, and Fig. 4 is a diagram of the same. . DESCRIPTION OF SYMBOLS 1... Rolling machine, 4... Rolling material, 11... Incline signal generator, 15, 16... Logic holding device, 17...
...Storage device, 18...Gradient signal generator, 20...
Timer device, 21... calculation device. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. A rolled material kicked out from a reversible rolling mill is decelerated and stopped at a predetermined position, and the rolled material stopped at a predetermined position is conveyed in the direction of the reversible rolling mill, and is bitten by the reversible rolling mill. In the method of controlling the speed of the table for rolling, when the rolled material is being rolled by the reversible rolling mill, the speed is controlled to the speed of the reversible rolling mill, so that the tail end of the rolled material is at the speed of the reversible rolling mill. Td time from the point of kicking out from the machine Td = 1/βVo (VI ² /2 - Vo ² /2) However, Vo: kicking speed, VI: biting speed of next rolling, β: table acceleration/deceleration , where μ is the frictional coefficient between the table and the rolled material, and g is the gravitational acceleration, there is a relationship β≦μg. is maintained at the speed of the reversible rolling mill at the time of kicking out, and after Td has elapsed, the speed is decelerated according to the acceleration/deceleration β, Ta time Ta=Ts−(Td+Vo/β+VI/β), where Ts: rolling reduction of the reversible rolling mill The time required to set the amount. 1. A table speed control method for a reversible rolling mill, characterized in that the table speed is stopped, and after Ta has elapsed, the rolled material is accelerated according to an acceleration/deceleration β to convey the rolled material in the direction of the reversible rolling mill.