JPH0315208Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for measuring roll gaps in a rolling mill, particularly in a rolling mill whose work rolls can be shifted in the axial direction.

[Prior Art] In rolling mills, roll gap management is important for maintaining the dimensional accuracy of products. Conventionally, when detecting this roll gap, the general method was to determine the position of the piston or ram of the cylinder using a position detector provided on the reduction cylinder, and convert this to the roll gap. but,
In the case of such a method, since it is affected by the elongation of the housing and the change in the volume of oil in the compression cylinder, these effects are corrected by calculation, and the accuracy has reached its limit.

To be more specific, FIG. 6 is a typical example of a roll position control system of a conventional rolling mill, and shows a rolling mill equipped with a control device of the Bisla control system. 2 in the diagram
7 is a rolling mill housing, 28 and 29 are work rolls, 30 and 31 are backing rolls, 32 is a ram of the rolling cylinder 33, 34 is a load cell, and 35 is a ram 3
2 is a displacement meter, and 36 is an arithmetic controller.

In Figure 6, if the plate thickness command value is xc, the rigidity coefficient of the rolling mill (generally called mill constant) is Km, the load constant is C, the displacement of the ram is x, and the rolling force is F, then in Bisla control, x= The displacement x of the ram 32 can be obtained from the relationship xc+C/KmF (1). That is, the ram 32 is displaced by C/Km greater than the command value xc to compensate for the expansion of the roll gap due to the elongation of the rolling mill and to eliminate variations in plate thickness.
Further, when C=1, it is possible to completely compensate for the influence of elongation of the rolling mill, and it is said that the ultimate goal of the Visla system can be achieved.

However, in this conventional method, instead of directly detecting the roll gap, the displacement of the ram of the rolling cylinder is detected, and the elongation of the rolling mill is calculated by detecting the rolling force using a load cell and dividing it by the mill constant. Because it is determined indirectly, there is a limit to accuracy due to the resolution of the load cell.

Furthermore, in recent years, the work rolls have been shifted in the axial direction in order to eliminate step wear on the rolls (usually referred to as plateway) caused by repeated rolling of rolled material with a constant width and to improve the shape of the rolled material. A rolling mill that can do this has been developed. In such a shift rolling mill, the roll deformation disturbance increases due to the shift of the work rolls compared to a normal rolling mill. Therefore, in order to accurately determine the roll gap using the roll gap detection method described above, a more complicated method is required. Calculation correction was required, further aggravating accuracy problems. For example, in equation (1), the mill constant Km is also related to the roll shift amount, so depending on the shift amount,
It is easy to see that accurate Bisla control cannot be achieved without changing Km. In other words, the correction calculation becomes that much more complicated.

[Problems to be solved by the invention] The present invention provides a method for easily and accurately detecting a roll gap in a rolling mill in which the work rolls can be shifted in the axial direction, without performing complicated disturbance correction calculations. This is what I did.

[Means for Solving the Problems] The present invention provides a rolling mill in which a work roll can be shifted in the axial direction. a movable member having a portion to
A roll gap detector is attached to a portion of the moving member located near the width end of the rolled material in close proximity to the roll gap of the work roll.

[Operation] Therefore, even if the work roll shifts, the detector moves together with the shift, so the positional relationship between the detector and the work roll is maintained, and the roll gap is accurately detected.

[Example] Hereinafter, an example of the present invention will be described based on the drawings.

1 and 2, upper and lower work rolls 1 and 2 have tapered portions 3 and 4 at opposite ends, respectively, and are movable in the axial direction by a shift device (not shown); 5 and 6 are axle boxes for the upper and lower work rolls 1 and 2, and each axle box 5 and 6 includes blocks 9 and 9 that have built-in bending cylinders 7 and 8, respectively.
10 is the rod 7 of the bending cylinder;
It is engaged with the work rolls 1 and 2 via a and 8a so that they can move together in the axial direction.

That is, as shown in the side view of FIG. 2, the axle boxes 5 and 6 have blocks 9 and
The block 10 can be left behind and can move freely, and can move together with the blocks 9 and 10 in the roll axis direction.

In such a rolling mill, the blocks 9 and 10 located on the tapered portions 3 and 4 have their detection heads 1 at the inner ends on the roll gap side, as shown in FIG.
Eddy current type roll gap detectors 13 and 14 are installed with the rollers 1 and 12 close to the roll gap.

FIG. 3 shows a block diagram of roll gap control, in which numeral 15 is an average value calculator that adds the signals from the detectors 13 and 14 to obtain an average value, and 16 is a roll gap controller that calculates the average value by adding the signals from the detectors 13 and 14. 17 is an adder that adds the signal from the converter 16 and the roll gap setting signal. 19 is a feedback signal from the signal from the adder 17 and the position detector 21 provided in the reduction cylinder 18. 21a, and if there is a difference, it sends a correction command to the servo valve 26 that controls the outflow and inflow of pressure oil to the pressure reduction cylinder 18.

That is, in the control system of the present invention, the initial roll gap is set based on the signal from the position detector 21 installed in the rolling cylinder 18, and the roll gap caused by the elongation of the rolling mill due to the load during rolling is controlled. The amount of expansion is detected by detectors 13 and 14 installed close to the roll gap and corrected.

In such a configuration, when detecting a roll gap between the upper and lower work rolls 1 and 2, the detector 13,
14 does not directly detect the roll gap, but rather detects the gap size x, y,
In addition, the gap dimensions x' and y' between the detection head 12 and the peripheral surfaces of the upper and lower work rolls 1 and 2 at the other end are detected, respectively, and these signals are sent to the calculator 15 to obtain the average value. The converter 16 converts it into a roll gap.

That is, when the detectors 13, 14 are attached to the blocks 9, 10, the distance from the detection heads 13, 14 to the center of the roll gap, the distance between the detection heads 13, 14
Since the distance between the start end of the tapered portions 3 and 4 of the work rolls 1 and 2, the angle of the taper portions 3 and 4, and the diameters of the work rolls 1 and 2 are all known, the calculation unit 15 A converter 16 can calculate the roll gap based on the above-mentioned values from the average value signal calculated.

Further, the roll gap conversion signal obtained by the converter 16 is sent to the control device 1 via an adder 17.
9 and is compared with the ram position signal 21a,
If there is a difference, a drive command is sent to the servo valve 26 and the roll gap is corrected through adjustment of the ram position of the reduction cylinder 18. That is, based on the roll gap conversion signal, the reduction ram 18a is pushed upward by that amount, narrowing the roll gap, correcting the elongation of the mill, and maintaining the initially set gap.

In the above, when the work rolls 1 and 2 shift in the axial direction, the blocks 9 and 10 also move together with the work rolls 1 and 2, so the detection heads 11 and
12 and the work rolls 1 and 2 are always maintained constant. Therefore, the work rolls 1 and 2 are rolled material S
No matter how you shift it to any position corresponding to the width of
Roll gaps can be detected without making any adjustments to the detection system.

Incidentally, in the embodiment described above, the average value of the roll gap was calculated by the calculating unit 15 and the correction work was performed.
Without determining the average value, the roll gap at each end position between the work rolls 1 and 2 is determined separately, and the roll gap at both ends of the work rolls 1 and 2, that is, the work side,
The gap may be adjusted separately on the drive side.

Figures 4 and 5 show other embodiments of the present invention, and show a rolling mill in which the work rolls 1 and 2 have ring grooves 22 and 23 in place of the tapered parts 3 and 4. . That is, as a roll gap detector, a light emitter 24 is attached to one of the blocks 9, 10 located on the ring grooves 22, 23 side, and a light receiver 25 is attached to the other block 9, 10 facing each other, and the work roll 1 is , 2 ring groove 22, 2
The light from the projectors 24, 24 passing between the work rolls 3 and the circumferential surfaces of the work rolls 2, 1 is received by the receivers 25, 25, respectively.
The roll gap is detected as a roll gap, and the signals from these light receivers 25, 25 are converted to an average value by the calculator 15, and the same control as in the previous embodiment is performed based on this signal.

In this method, the depth of the ring grooves 22 and 23 is constant, so even if the work rolls 1 and 2 shift or the roll gap changes, the roll gap can be directly detected easily and reliably. ,
Detection accuracy is further improved.

In the above embodiment, the roll gap detector was attached to the block, but a beam was installed between each axle box 5, 5 and between each axle box 6, 6 so that it could move in the axial direction together with the work rolls 1, 2. A detector may be attached to a desired position of this beam. It goes without saying that a detector other than the eddy current type or optical type may be used as long as it is a non-contact type detector.

[Effects of the invention] As explained above, according to the invention, a roll gap detector is placed close to the roll gap in the portion of the movable member that moves together with the work roll, which is located near the width end of the rolled material. Since the roll gap is installed at the width end of the rolled material, it is possible to directly detect the roll gap at the width end of the rolled material. Therefore, the roll gap can be easily and accurately detected without being affected by deflection of the work roll. It can have a great effect.

[Brief explanation of the drawing]

Fig. 1 is a schematic front view of the rolling mill of the present invention, Fig. 2 is a side view of Fig. 1, Fig. 3 is a view taken from - arrow in Fig. 1, and Fig. 4 shows another example of the present invention. Explanatory diagram, 5th
The figure is a view taken along the - arrow in FIG. 4, and FIG. 6 is an explanatory diagram of the conventional device. 1 and 2 are work rolls, 5 and 6 are axle boxes, 9 and 10
1 is a block, 13 and 14 are detectors, 23 is a light projector, and 24 is a light receiver.

Claims (1)

[Scope of utility model registration request] In a rolling mill in which a work roll can be moved in the axial direction, a moving member that moves in the axial direction integrally with the work roll and has a portion located near the width end of the rolled material is provided, and the moving member is moved in the axial direction. 1. A rolling mill characterized in that a roll gap detector is attached to a portion located near the width end of a rolled material in close proximity to a roll gap of a work roll.