JP2882955B2 - Oil column flow rate gain correction device in hydraulic pressure reduction control - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flow rate gain correcting device for eliminating a change in response of a hydraulic pressure reduction cylinder due to an oil column in hydraulic pressure reduction control.

[0002]

2. Description of the Related Art A conventional hydraulic pressure reduction control technique will be described with reference to FIG. In FIG. 4, a hydraulic pressure reduction cylinder (hereinafter, referred to as a pressure reduction cylinder) 8 is provided between the housing 1 of the rolling mill and the upper backup roll 2, and the pressure reduction cylinder 8 is connected to a pressure oil pipe 12 communicating with a hydraulic pressure source 12 '. A servo valve 13 is provided in the middle of the pressure oil pipe 12. An oil column position detector 10 is provided in the pressing cylinder 8. The control device 16 controls the servo cylinder 13 by operating and controlling the servo valve 13, and is connected to the oil column position detector 10 and the servo valve 13. 4, 3 is a lower backup roll, 4 and 5 are upper and lower work rolls, 6 is a rolled plate, 7 is a load cell, 9 is a ram, 11 is an oil column to be detected, 14 is a hydraulic pump, and 15 is a pump. The driving motors are respectively shown.

[0003] The control device 16 includes an oil column target value transmitting unit 17,
Reference flow rate gain calculator 18, adder 19, and accumulator 2
0, a converter 21 and the like. In the reference flow gain calculating section 18 of the control device 16, since the flow characteristic of the servo valve 13 changes depending on the hydraulic pressure on the servo valve outlet side, that is, the load, the gain is corrected for the purpose of correcting this change. The optimum flow rate gain under each load detected by the load cell 7 in the stage is obtained. Using the reference flow gain obtained in this way, the oil column target value transmitter 1
An oil column target value signal output from the control unit 7 is integrated by an integrating unit 20, and the output of the integrating unit 20 is passed through a converter 21 to control a servo valve 13 to operate a pressure reduction cylinder 8, and an oil column position detector The actual position signal of the oil column 11 from 10 is fed back and compared by the adding unit 19, so that the oil column 11 is controlled so as to reach a predetermined value.

As described above, in the conventional hydraulic pressure reduction control, the flow rate gain is corrected by the load, but is not corrected for the oil column 11 and the flow rate gain is constant. Therefore, as the height of the oil column 11 of the reduction cylinder 8 used increases, the response of the reduction cylinder 8 to a change in the oil column deteriorates (response delay). Therefore, conventionally, in order to obtain a constant response, it was necessary to readjust the reference flow rate gain each time the target oil column was changed.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the response delay to the change in the oil column and the readjustment of the flow rate gain required for each change in the target oil column in the prior art. An object of the present invention is to provide an oil column flow rate gain correction device.

[0006]

According to the present invention, there is provided an oil column flow rate gain correcting device in hydraulic pressure reduction control which achieves the above object.
A memory in which the calculated value of the correction ratio of the pre-measured optimum flow gain in the plurality of representative oil columns of the hydraulic pressure lowering cylinder to the flow rate gain in the reference oil column is set. A calculating unit for calculating the flow rate gain correction ratio of the target oil column, an integrating unit for integrating and correcting the obtained flow rate gain correction ratio to the flow rate gain of the reference oil column, and outputting an optimal flow rate gain for the target oil column; An accumulator for integrating the flow rate gain output from the unit to the difference between the target oil column signal and the actual oil column and transmitting the result to the servo valve.

[0007]

[Action]

(1) In the adjustment stage of the device, optimal flow gains of a plurality of representative oil columns including the reference oil column of the rolling-down cylinder are previously obtained by measurement, and the correction ratio of the flow gain of each representative oil column to the flow gain of the reference oil column is determined. Is calculated and set in the memory. (2) In the actual operation stage, when the oil column of the rolling-down cylinder is set in the control device, the calculation unit calculates the correction ratio corresponding to the set oil column by the polygonal line of the correction ratio of the representative oil column stored in the memory. Is calculated in approximation proportional to and is passed to the integrating unit. (3) The integrating section integrates the correction ratio into the flow rate gain of the reference oil column, and passes the flow rate gain corrected by the oil column to the next integrating section. (4) The accumulator integrates the flow rate gain corrected by the oil column with the difference between the target oil column signal indicating the target oil column and the actual oil column result to obtain a servo valve operation amount. And automatically operate. (5) As a result, the oil column of the screw-down cylinder that expands and contracts by the servo valve is controlled by operating the servo valve with the flow rate gain corrected according to the oil column. As a result, a uniform response can be obtained for each oil column, and the readjustment of the flow rate gain for each change in the oil column required by the conventional response delay is eliminated. (6) The height of the oil column of the rolling-down cylinder is detected by an oil column position detector, fed back to the control device, and compared with the indicated oil column height, so that control is performed to reach the target oil column. Will be

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an oil column flow rate gain correction device in hydraulic pressure reduction control according to one embodiment of the present invention. The same reference numerals are given to the same functional parts as in FIG. 4 showing the conventional example, but in FIG. 1, a rolling cylinder 8 is provided between the housing 1 of the rolling mill and the upper backup roll 2, and the rolling cylinder 8
Is connected to a pressure oil pipe 12 communicating with a hydraulic pressure source 12 ′, and a servo valve 13 is provided in the middle of the pressure oil pipe 12. An oil column position detector 10 is provided in the pressing cylinder 8. A load cell 7 is provided between the housing 1 and the lower backup roll 3 for detecting a load. The control device 16 controls the pressure reduction cylinder 8 by operating and adjusting the servo valve 13, and includes the load cell 7, the oil column position detector 10, and the servo valve 13.
It is connected to the. 1, 4 and 5 are upper and lower work rolls, 6 is a plate to be rolled, 9 is a ram, 11 is an oil column to be detected, 14 is a hydraulic pump, and 15 is a pump driving motor.

The control unit 16 includes, in addition to the oil column target value transmitting section 17, the reference flow rate gain calculating section 18, the adding section 19 and the converter 21, a memory 30, a calculating section 31, and integrating sections 32, 3.
The optimum servo operation amount is automatically supplied to the servo valve 13 for each control target oil column.

In the memory 30, after the optimum flow rate gains of the plurality of representative oil columns of the rolling down cylinder 8 are measured in advance,
Correction ratios of these optimum flow gains to the flow gain at the reference oil column are calculated, and these correction ratios are set. A specific example will be described with reference to FIG. FIG. 2 shows the memory 3
An example of how to determine the representative oil column to be set to 0 is shown in a graph,
The horizontal axis indicates the oil column height [mm], and the vertical axis indicates the flow rate gain correction ratio depending on the oil column height. As the representative oil column, take 30 mm, 50 mm, and 70 mm, including the reference oil column 10 mm, and obtain the optimum oil pressure flow rate gain supplied from the servo valve for each representative oil column by measurement at the adjustment stage of the hydraulic pressure reduction control device, The flow rate gain obtained for each representative oil column is set as a ratio of 1 to a reference oil column of 10 mm to determine a correction ratio for each of the other oil columns. Is set to

The calculation unit 31 obtains a flow rate gain correction ratio of an arbitrary target oil column from a set value of the memory 30 by a linear approximation proportional calculation. For example, when the target oil column height of the rolling-down cylinder 8 is 60 mm in the apparatus of FIG. 1, the correction ratio calculating unit 31 calculates the correction ratio points a of the representative oil columns 50 mm and 70 mm in FIG. The correction ratio 1.35 to the target oil column of 60 mm is calculated by approximate proportional calculation from the right triangle c having a polygonal line connecting the lines b and b as an oblique line.

The integrating section 32 integrates and corrects the obtained flow rate gain correction ratio to the flow rate gain of the reference oil column, and outputs an optimal flow rate gain for the target oil column. For example, in the case of FIG. 2, assuming that the optimal flow gain at the reference oil column of 10 mm is 200 in absolute value, the optimum flow gain for the target oil column of 60 mm is obtained as 270 by the calculation of 200 × 1.35 = 270.

The accumulator 33 corrects the flow gain output from the accumulator 32 to the difference between the target oil column signal from the oil column target value transmitter 17 and the actual oil column signal. The signal is transmitted to the servo valve 13.

Thus, an optimum servo valve operation amount, that is, a flow rate gain signal is automatically supplied to each control target oil column. The oil column height 11 of the pressure-reducing cylinder 8 controlled by the servo valve 13 is detected by the position detector 10,
The adder 19 provided upstream of the integrating unit 33 performs addition and comparison with the oil column target value signal, and performs feedback control so that the error becomes zero.

FIG. 3 shows a control flow of the oil column flow rate gain correction device described above. When controlling the rolling-down cylinder 8, the steps S10 to S13 in FIG.
As shown in the figure, the optimum flow gain at several representative oil columns in the rolling-down cylinder 8 is obtained by measurement, and from each optimum flow gain, (representative oil column flow gain) / (reference oil column flow gain)
The flow rate gain correction ratio is calculated by the following equation, and the flow rate gain correction ratio for each representative oil column is set in the memory 30.

In this state, the apparatus performs step S2
The target oil column is given by the numerical value A to the control unit as in 0, S21, and the operation starts formal (actual) operation.

In the formal operation, as shown in steps S22 to S31, first, the calculation unit 31 calculates the flow rate gain correction ratio corresponding to the target oil column A in approximate proportion from the broken line of the ratio of the representative oil column stored in the memory 30. After calculating, the calculated flow rate gain correction ratio is sent to the integrating section 32, and is integrated with the flow rate gain of the reference oil column to obtain the optimum flow rate gain at the target oil column. It is integrated with the instruction signal from the column target value transmission unit 17, sent to the servo valve 13 via the converter 21, and the operation of the servo valve 13 causes the reduction cylinder 8 to expand and contract. The height of the oil column 11 of the rolling-down cylinder 8 is captured as a numerical value A 'by the position detector 10, fed back to the control device 16 and compared with the target numerical value A by the adder 19 so that the target oil column A is achieved and held. Is automatically controlled. As a result, the response delay due to the oil column of the rolling cylinder according to the conventional method and the necessity of re-adjustment of the flow rate gain every time the target oil column is changed are eliminated, and an effect of performing an efficient hydraulic rolling reduction operation can be obtained.

[0018]

As described above, the oil column flow rate gain correction device according to the present invention is a control device for operating a reduction cylinder to a target oil column via a servo valve. A memory that measures the gain in advance, calculates the ratio of the reference oil column to the flow rate gain, and sets and stores it.A calculation to calculate the flow rate gain correction ratio of an arbitrary oil column by a polygonal line approximate proportional calculation from the set value in the memory Section, an integrating section that integrates the flow rate gain correction ratio of the oil column into a reference oil column flow gain, and outputs an optimum flow rate gain of the oil column, and a flow rate gain output from the integrating section to a target oil column. By providing an integrating unit that integrates the operation amount signal and transmits the servo valve, the response delay of the conventional hydraulic cylinder oil column in this type of hydraulic pressure reduction control device and the target oil column Eliminating the required flow rates gain adjustment Saragoto may correspond automatically calculating the optimum flow gain upon change in the target oil column.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an oil column flow rate gain correction device according to one embodiment of the present invention.

FIG. 2 is a diagram showing an example of a method of obtaining a flow rate gain correction ratio for an oil column.

FIG. 3 is a diagram showing a control flow.

FIG. 4 is a diagram showing a conventional example.

[Explanation of symbols]

 Reference Signs List 8 Lowering cylinder 10 Oil column position detector 11 Oil column 13 Servo valve 16 Control device 17 Oil column target value transmission unit 18 Reference flow rate gain calculation unit 19 Adder 21 Converter 30 Memory 31 Flow rate gain correction ratio calculation unit 32, 33 Accumulator

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B21B 37/00

Claims (1)

(57) [Claims] An oil column flow gain correction device for a control device for operating a hydraulic pressure reduction cylinder to a target oil column via a servo valve, wherein a reference of an optimum flow rate gain measured in advance in a plurality of representative oil columns of the hydraulic pressure reduction cylinder is provided. A memory in which the calculated value of the correction ratio for the flow rate gain in the oil column is set, an operation unit for obtaining a flow rate gain correction ratio of an arbitrary target oil column from the set value in the memory by a linear approximation proportional calculation, and a calculated flow rate gain An integrating unit that integrates and corrects the correction ratio to the flow rate gain of the reference oil column, and outputs the optimal flow gain for the target oil column, and calculates the difference between the target oil column signal and the actual oil column result by calculating the flow rate gain output from this integrating unit. An oil column flow rate gain correction device for hydraulic pressure reduction control, comprising: