JPS582486Y2 - tension control device - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a tension control device, particularly one that realizes stable control of a device having a cutting machine for cutting a rolled material.

A conventional device of this type is shown in FIG.

100 is the first rolling mill, 200 is the second rolling mill, 300 is the third rolling mill, 1 is the rolling mill roll, 2 is the rear tension Tbl acting on the first rolling mill, and 3 is the front tension acting on the first rolling mill. Tension Tf1- or rear tension Tbz-4 acting on the second rolling mill
is the forward tension Tfz acting on the second rolling mill, 5 is a load cell, 6 is a roll drive motor, 7 is a speed control device, 8 is a speed detector that measures the roll speed, 9 is a tension calculation device, 1
0 indicates a tension control reference value Tf, 11 indicates a tension adjustment device 12 for rolling material, and 20 indicates a crop shear which is a cutting device.

Inter-mill tension control in a continuous rolling mill is expressed as follows from rolling theory.

Gi=aiFi+biTbi+ciTfi...-
・・・・・・・・・・・・・・・(1) Here, i Rolling mill number G Rolling torque F Rolling force T Tension force a Torque arm b Rear tension arm coefficient C Front tension arm coefficient (In formula D, ai, bi, ci is a constant G determined by rolling conditions, and F is a value that can be measured during rolling.

Therefore, the tension between each rolling mill is In equation (2), If we focus on the first rolling mill.

b1 is the rear tension acting on the entry side of the first rolling mill, and is usually Tbt
=O.

Therefore, regarding the first rolling mill (it becomes a unit).

Here, the control block and its operation in FIG. 1 will be explained.

The calculator 9 that calculates the equation (2) calculates the tension according to the equation (2), and the Gi (torque) in the equation (2) is obtained by manually calculating the current (2) of the electric motor 6, the voltage V, and the roll speed S.

On the other hand, the rolling load F1 is detected from the load cell 5.

As can be seen from equation (3), if we focus on the first rolling mill, Tb
Since x=O, the output of the arithmetic unit 9 is Tf in equation (3)
1, which means the tension between the first and n-th rolling mills.

This tension Tf1 is compared with the tension control target value Tfl, and the deviation ΔT1 is determined by the tension control device 11.
is input.

Here, it has a control function that compensates for the gain response of tension control.

The output outputs a speed correction command to the speed control device 7 that controls the electric motor 6 in order to make the tension deviation ΔT zero.

On the other hand, in the crop shear 20, the tip 5 of the rolled material 12
Cut off the bad shape of the tail end.

What we will focus on here is the 1 tail end cutting, and at this time the rolled material 1
In No. 2, the front portion is already being rolled in a continuous rolling mill, and the tension is controlled during the rolling period.

This is shown in FIG.

In Figure 2a, time is plotted on the horizontal axis, and backward tension is plotted on the vertical axis, and in Figure 2A, time is plotted on the horizontal axis, and forward tension is plotted on the vertical axis.

In the conventional method, when the crop shear 20 cuts the tail end, a large rear tension is instantaneously generated.

Although the rear tension is generated, the tension calculator 9 calculates the tension on the assumption that the rear tension is not generated, and the controlled longitudinal tension of the first rolling mill decreases.

As mentioned above, the first rolling mill rear tension Tb1 is just T
As b1-0, the first rolling mill front tension Tf1 is calculated, and from the second rolling mill onward, the second rolling mill front tension is calculated as TfITb2 from equation (2).

Similarly, for the n-th rolling mill, Tfn-1Tbn is obtained, and the tension between the rolling mills is determined.

At this time, if T'b1 = "0" when cutting the tail end of the material, the time is only 1 sec or less, but in terms of calculation, even if Tb1 - 0, G and F change, so as shown in Figure 2, the time between all rolling mills is This caused an extremely large increase in tension, which had an extremely negative impact on operations and control.

This invention was made to eliminate the drawbacks of the conventional methods, and uses the instantaneous tension that cannot be measured during cutting to detect the starting point of the cutting operation (the point at which the blade contacts the plate) and the completion of cutting. By retaining the value of the front tension Tf1 of the first rolling mill that is calculated moment by moment for only that period, changes in the rolling pressure of the first rolling mill and changes in motor torque due to fluctuations in the rear tension of the first rolling mill are suppressed. It is an object of the present invention to provide a stable tension control device between rolling mills without transmitting tension after two rolling mills.

An embodiment of this invention will be described below with reference to FIG.

13 is a contact of a relay that cuts off the signal circuit, 14 is a signal storage device, 15 is a contact of a relay that cuts off a signal circuit, 22 is a Norx oscillator attached to the crop shear 20, and 23 is a shear angle detector. , 24 (Cutting board cutting angle setting device, 25
is a relay that is energized when the angle output of the angle detector 230 and the set angle output of the cutting angle setter 24 match, and the contact 13
is opened and contact 14 is closed.

Reference numeral 26 denotes a cutting completion angle setting device, and the angle at which the two shear blades come together, for example, is set as the cutting completion angle.

27 is a relay, and when the angle output of the angle detector 230 and the set angle output of the cutting completion angle setting device 26 match, contact 1 is activated.
3 is opened and contact 15 is closed.

The rest is the same as in FIG. 1 and will be omitted. The operation shown in FIG. 3 will be explained.

It has already been mentioned that the tension between successive rolling mills is normally controlled as Tbx=O.

Focusing on the first rolling mill, 1. Normally, the output of the tension calculator 9 is that the relay contact 13 is closed, and the output Tf1 of the tension calculator 9 and the reference value Tf? The difference △T from the tension adjustment device 11
is output to.

At this time, the relay contact 15 is in an open state.

Now, the shear angle detector 23 constantly detects the angle of the blade according to the motion of the shear by the crop shear pulse transmitter 22.

The cutting angle setter 24 calculates the contact point between the blade and the plate based on the plate thickness, and sets the point as the cutting start angle.

On the other hand, the cutting completion angle setting device 26 determines the angle at which the blade angle comes directly below, that is, the angle at which the two shear blades come together, as the cutting completion point.

When the output angle of the angle detector 23 and the set angle of the cutting angle setter 24 match, the relay 25 opens the contact 13, closes the contact 15, and outputs the tension value stored in the signal storage device 14. .

At this time, the tension calculator 19 only calculates Tb as 0, but in reality, G (torque) and F (rolling force) of the first rolling mill change due to the rear tension generated during cutting, so Tfl changes. Since the relay contact 13 is open, the front tension of the first rolling mill is the tension before cutting, which is held in the memory device 14, and since the contact 15 is closed, the stored value is calculated. is compared with the reference value Tf1, and the deviation is input to the tension adjustment device 11.

Further, when the set angle of the cutting completion angle setter 26 and the output of the angle detector 23 match, the relay 21 is energized, thereby closing the contact 13 and opening the contact 15, Tb1
= Returns to the contact state of o.

In this way, disturbances during cutting can be removed.

Even if there is a cutting device or a winding device behind the final rolling mill, the front tension is calculated here as Tfn = 0, but as mentioned above, the front tension is generated as Tfnz'0 when cutting or winding the material. This idea can also be applied when

As described above, according to this invention, by knowing the cutting point and controlling the tension, the memorized value before cutting is held for that period and the tension is controlled according to the memorized value, thereby making it possible to perform stable tension control, and to achieve stable tension control at low cost. A control device can be realized.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a conventional tension control device. FIG. 2 is an explanatory diagram for explaining FIG. 1, and FIG. 3 is a block diagram showing an embodiment of this invention. In the figure, 11 is a tension adjustment device, 13.15 is a contact, 14 is a storage device, 20 is a crop shear, 22 is a pulse generator,
23 is an angle detector, 24 is a cutting angle setter, 25, 27
is a relay. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Scope of utility model registration request] In a tandem rolling mill having a cutting machine that cuts a rolled material, a tension calculator that calculates the tension between the rolling mills; a memory that stores the output of the tension calculator; the tension calculator or the iB
a tension adjustment device that adjusts the tension between the rolling mills by adjusting the speed of the roll drive motor so that the longitudinal force value between the rolling mills from the rolling machine becomes a reference tension value; and the cutting machine starts cutting the rolled material. During the cutting action period until the cutting is completed, the calculated tension signal from the tension calculator to the tension W device is blocked, and the stored tension signal at the time of the start of cutting is held in the storage device, and the stored tension signal is stored at the tension W device. A tension control device comprising a signal transmission control device for transmitting a calculated tension signal from a tension calculator to the tension adjustment device during the cutting action period.