JPS6336849B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Description of the Technical Field The present invention relates to a table for conveying material in a rolling mill that changes the thickness of a material to be rolled (or material to be rolled) during rolling. This invention relates to a table speed compensation method.

Please note that changing the plate thickness to a large extent during rolling
This will be referred to as changing the running plate thickness.

(b) Description of the prior art Changing plate thickness during running is carried out to produce plates with different thicknesses from a single material, and to improve material yield and save energy.

The rolled material has a shape as shown in FIG.

FIG. 1a shows the shape before being rolled in a rolling mill.

Figure 1b shows that when the roll interval of the rolling mill is changed during rolling and the material plate thickness is made smaller than before the change,
FIG. 1c shows the shape of the material when it is made larger than before the change.

In this way, when the material plate thickness at the exit side of the rolling mill is changed, the material speed at the input side and the material speed at the exit side of the rolling mill change.

In particular, when changing the plate thickness during running, the material speed change on the entry side of the rolling mill becomes large.

In addition, the speed of the table that transports the material to the rolling mill is such that the rolls on the table scrape the material, causing scratches on the material that make it impossible to use it as a product, or the power converter that drives the table running into an overcurrent as it tries to maintain the speed. The speed must be matched to the speed of the material being rolled so that it does not cause any problems or trip the power converter.

Therefore, if the table speed is given at a fixed draft value that is set from the exit side plate thickness predicted from the inlet side material plate thickness and the reduction amount for the rolling mill speed, as in the past, the exit side material will be reduced to a large extent. When the plate thickness is changed during running, a situation occurs where the speed of the material to be rolled and the table speed do not match, which causes the above-mentioned problem and impedes the operation.

(c) Purpose of the Invention The present invention has been made based on the above-mentioned circumstances, and it is an object of the present invention to ensure that the table speed always matches the speed of the material being rolled in a rolling mill that changes plate thickness during running, thereby enabling smooth operation. The purpose is to provide a table speed compensation method.

(d) Summary of the invention In order to achieve the above object, the present invention has the following configuration. In other words, when rolling a material to be rolled using a rolling mill, when changing the thickness of the material during rolling, the thickness of the material at the entrance of the rolling mill
Measure h _i and outlet plate thickness h _p , and calculate the table conveyance speed V _Ti of the rolled material in the rolling mill from these two plate thicknesses and the roll speed V _R of the rolling mill = h _p +3h _i /4h _i・h It is determined based on _p /h _{i VR} , and the conveyance speed V _Ti of the table is made to match the speed of the material to be rolled to eliminate slipping of the material to be rolled on the table.

(e) Structure and operation of the invention The present invention will be explained below with reference to an embodiment shown in FIG.

The material 2 rolled by the first rolling mill 1 is conveyed by the table 3 and rolled by the second rolling mill 4. The invention does not apply to continuous rolling mills in which material 2 is rolled simultaneously.

The second rolling mill 4 uses a rolling device (not shown) to change the distance between rolls to change the thickness of the rolling plate.

The first rolling mill 1 is equipped with a load cell 5 that can detect the rolling load, and the rolling load is inputted from the load cell 5 to the rolling mill exit side material plate thickness detector 6, and the following formula is used to calculate the rolling load of the first rolling mill 1. Measure the exit material plate thickness h _i .

h _i =h _i /M _i +S _i (1) where P _i : rolling load of the first rolling mill M _i : mill constant S _i : roll spacing of ). Here, equation (1) has the following meaning.

The rolling mill undergoes elastic deformation due to the rolling load, and the roll gap changes. The Mill constant expresses the relationship between rolling load and roll gap change. Therefore, the change in roll gap determined from the rolling load
The sum of Pi/Mi and the roll spacing S _i before rolling is equal to the plate thickness h _i . The same applies to equation (2) described below. The material 2 leaving the first rolling mill 1 is conveyed as it is by the table 3 in the shape shown in FIG. 1a.

Therefore, the material plate thickness h _i on the outlet side of the first rolling mill 1 measured by equation (1) becomes the material plate thickness on the inlet side of the second rolling mill 4.

The material rolled by the second rolling mill 4 has the shape shown in FIG. 1b or c. The outlet side plate thickness h _p of the second rolling mill 4 is determined by detecting the rolling load using the load cell 7 provided in the second rolling mill 4, inputting it to the rolling machine outlet side material plate thickness detector 8, and measuring it using the following formula. .

h _p =P _p /M _p +S _p (2) where P _p is the rolling load of the second rolling mill, M _p is the mill constant of 〃 S _p is the roll spacing of 〃.

Inlet side material plate thickness h _i and outlet side material plate thickness h _p of the second rolling mill 4 measured by outlet side material plate thickness detectors 6 and 8
is input to the input table speed reference calculator 9.

In addition to the above-mentioned material plate thicknesses h _i and h _p , the roll speed V _R of the second rolling mill 4 is also input to the entry side table speed reference calculator 9 .

The roll speed V _R is determined by a tachometer generator 11 directly connected to the shaft of a motor 10 that drives the second rolling mill 4.
The rotation speed of the second rolling mill 4 is detected, and the roll diameter and gear ratio of the second rolling mill 4 are detected by the speed detector 14.
Find it by multiplying by.

The input side table speed standard calculator 9 calculates the input side table speed standard V _Ti using equation (5) derived from the following equations (3) and (4).
seek.

V _Ti = (1+f)h _p /h _i V _R ...(3) From experience, f≒1/4r=h _p -h _i /4h _i ...(4) ∴V _Ti =h _p +3h _i / 4h _i・h _p /h _i V _R ……(5) If h _p and h _i have a special relationship, V _Ti =3/4・h _p /h _i V _R ……(6) .

however, r: rolling reduction rate f: Advanced rate It is.

Note that although the calculation formula used in the entry side table speed reference calculator 9 is an approximate formula, another rolling theoretical formula may be used.

In the present invention, the thickness of the material at the entrance of the second rolling mill is measured at the first rolling mill, but it may also be measured using a thickness meter or the like at the entrance of the second rolling mill.

Moreover, although the second rolling mill roll speed is given using a tachometer generator, there is no problem in giving the speed setting value of the second rolling mill.

The input side table speed reference V _Ti obtained by the input side table speed reference calculator 9 is determined by the advance compensation circuit 10.
is applied to the power converter 12 that drives the table motor 13.

The lead compensation circuit 10 compensates for the table response delay with respect to the speed reference V _Ti , and may not be provided if the response delay is not a problem.

(f) Effects of the Invention As described above, according to the present invention, the table speed can be adjusted as needed according to the change in the thickness of the material due to the change in the thickness of the running plate.
This allows for smooth operation without scratching the material with table rolls or tripping the power converter that drives the table motor.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the shape of the material, and FIG. 2 is a block diagram for embodying the table speed compensation method of the present invention. 1...First rolling mill, 2...Material, 3...Table, 4...Second rolling mill, 5...Load cell, 6...
...Rolling machine outlet side material plate thickness detector, 7... Load cell, 8... Rolling machine outlet side material plate thickness detector, 9... Inlet side table speed reference calculator, 10... Second rolling mill motor, 11... Tachometer generator, 12... Power converter, 13... Table motor, 14...
...Second rolling mill speed detector.

Claims (1)

[Scope of Claims] 1. When the material to be rolled is conveyed by the entrance table of the rolling mill and rolled in the rolling mill, when the thickness of the material to be rolled is changed during rolling, the material to be rolled in the rolling mill is Measure the side plate thickness h _i and the outlet side plate thickness h _p of the rolled material, and from these two plate thicknesses and the roll speed V _R of the rolling mill, calculate the table conveyance speed of the rolled material on the entry table of the rolling mill to V _Ti. A table speed compensation method characterized in that it is determined based on V _Ti =h _p +3h _i /4h _i・h _p /h _{i VR} .