Abstract: Disclosed is a solenoid type electromagnetic operating device which needs a relatively large current only for a limited short period at an excitation start initial stage and is adapted to achieve the speeding up at an excitation start stage and an improvement in responsiveness as well as power saving without increasing a power load on each of a drive circuit and power supply.

Abstract: A hydraulic power system includes a reversible pump, a variable-speed servomotor for driving the pump, a pressure sensor for detecting load pressure, a detector for detecting the motor speed, signal command units for generating preprogrammed pressure and flow rate commands, a rotational speed controller and a signal processor. The signal processor preferentially outputs a speed command corresponding to the flow rate command by a limiter operation when the difference signal between the pressure command and the pressure detection signal is higher than a predetermined level, whereas it preferentially outputs a speed command corresponding to the difference signal when the difference signal is equal to or lower than said level. The rotational speed controller controls the magnitude of a driving current supplied to the servomotor by a closed loop on the basis of the speed command and the detected signal so that the speed of the servomotor corresponds to the speed command.

Abstract: A dimension control device for continuous rolling machine includes a correction mechanism for correcting a set tension of the rolling machine in accordance with temperature variations of a rolling material. With such a dimension control device, the width of the rolling material is controlled to a contstant at all times regardless of any variation in the temperature.

Abstract: A control device for a continuous rolling machine adjusts the rolling position of an ith mill stand to correct a first rolling material dimension and simultaneously controls the rolling position of an (i-1)th mill stand to adjust a perpendicular dimension of the rolling material to compensate for changes caused by the adjustment of the rolling position of the ith mill stand.

Abstract: A control device for a rolling machine includes a forecaster for predicting a change in the lateral dimension of a rolled material at the exit of a downstream mill stand based on dimensional variations, and a mechanism by which the tension on the material between two mill stands is altered in accordance with the forecast value, to control the lateral dimension of rolled material exiting the last of a series of mill stands.

Abstract: A rolling mill control device detects a dimension or dimensions of a product material between two mill stands, and forecasts a width deviation value of the material at a downstream stand on the basis of rolling characteristics of the material, etc. The position of an upstream stand is then varied to reduce the forecast value to zero. Feedback control is also effected on the position of the upstream stand based upon the difference between a reference width and an actually measured value.

Abstract: A control device for a continuous rolling machine effects feedback control by measuring vertical and lateral dimensions at a point after an ith mill stand, and by controlling the tension in the material between an i-1th and the ith mill stand and the position of the ith mill stand to reduce the differences between the detected dimensions and reference dimensions to zero. A shape correction device may be used which calculates lateral and vertical dimension change values for the i-1th stand, which are used to control the position of the i-1th stand and the tension in the material between an i-2th mill stand and the i-1th stand to assist in bringing the actual dimensional output values into coincidence with the reference values.

Abstract: When two strand workpieces pass through a roll opening between two grooved working rolls on a roll stand so as to be rolled, the trailing end of one of them may leave the rolls and cause change in the roll separation. At that time mating bilateral screw-down devices are remotely controlled to adjust the roll opening at least at the position of the remaining workpiece. Alternatively in a multi-strand tandem rolling mill, the rolling speeds on roll stands upstream of a roll stand which one of the strand workpieces has left are changed by a speed ratio of (1-b.sub.2)/(1-b.sub.1) where b.sub.1 and b.sub.2 respectively designate rates of backward slip when two strand workpieces are being rolled and in the absence of one of the strand workpieces from the last-mentioned roll stand. Alternatively the roll speeds on roll stands downstream of the roll stand which one of the strand workpieces has left may be changed by a speed ratio of (1+f.sub.2)/(1+f.sub.1) where f.sub.1 and f.sub.

Abstract: The forward slip and the backward slip at a first stand are dependant upon a draft, the back tension, the front tension, and the shape of a sheet in a tandem type rolling mill. It is difficult to control the shape solely by detecting the tension distribution between the last stand and the tension reel.In the method of this invention, the shape of a rolled sheet is controlled by disposing a first shape meters between the pay-off reel and the first stand and a second shape meter between the last stand and the tension reel whereby shape control can be attained through a simple system.Tension distributions detected by the two shape meters are functions of the forward slip and the backward slip.