A calibration determination device includes: a free roll that conveys the bonding member; a load detection device that detects a load applied to a bearing of the free roll; a tension adjustment device that winds the bonding member to increase a tension applied to the bonding member and unwinds the bonding member to reduce the tension applied to the bonding member so as to adjust the tension applied to the bonding member; and a calibration determination unit that determines whether calibration of the load detection device is necessary. The tension adjustment device unwinds the bonding member to cause the bonding member not to be subjected to the tension, and the calibration determination unit determines whether the calibration of the load detection device is necessary based on the load detected by the load detection device with the bonding member not being subjected to the tension.

This circular rolling mill has a fixed main frame, a pair of cylindrical rollers, internal and external, to shape internal and external radial faces of an annular part and supported by a first secondary frame mounted on the main frame, as well as a pair of conical rollers, upper and lower, to shape opposite front faces of the part and supported by a second secondary frame mounted on the main frame. At least one rack and pinion assembly moves a roller in translation relative to one of the secondary frames. At least one electric geared motor drives the pinion of the rack and pinion assembly. The electric geared motor is fixedly mounted relative to one of the auxiliary frames. A fluid discharge mechanism is interposed in a kinematic chain for transmitting force between the rack and the roller moved by this rack. The fluid discharge mechanism has at least one variable volume chamber supplied with pressurized fluid and the volume of which varies as a function of the relative position of the roller and of the rack.

This circular rolling mill has a fixed main frame, a pair of cylindrical rollers, internal and external, to shape internal and external radial faces of an annular part and supported by a first secondary frame mounted on the main frame, as well as a pair of conical rollers, upper and lower, to shape opposite front faces of the part and supported by a second secondary frame mounted on the main frame. At least one rack and pinion assembly moves a roller in translation relative to one of the secondary frames. At least one electric geared motor drives the pinion of the rack and pinion assembly. The electric geared motor is fixedly mounted relative to one of the auxiliary frames. A fluid discharge mechanism is interposed in a kinematic chain for transmitting force between the rack and the roller moved by this rack. The fluid discharge mechanism has at least one variable volume chamber supplied with pressurized fluid and the volume of which varies as a function of the relative position of the roller and of the rack.

A control apparatus of a tandem rolling mill includes a speed command output unit configured to temporarily output a speed command value to each of a plurality of stands before a tandem rolling mill is activated while in a state where a rolled material is sandwiched between the plurality of stands, and a Droop amount setting unit configured to set a Droop amount set value of the stand smaller toward rear stage of the plurality of stands, during a period in which the speed command output unit temporarily outputs the speed command value. Including the configuration makes it possible to more surely prevent rupture of the rolled material. The control apparatus of the tandem rolling mill makes it possible to more surely prevent rupture of a rolled material.

Regarding each rolling mill, a rolling torque Gi before biting into a downstream stand is stored, the peripheral velocity of a most downstream stand Rn is controlled to be Gn1=Gn1* after biting into Rn, and a rolling torque Gn** of Rn after tension is stabilized is stored. After that, the peripheral velocity of a rolling mill Ri is controlled to be Gi=Gi* toward an upstream side, and the peripheral velocity of a rolling mill Rk at a downstream side of the rolling mill Ri is controlled to keep Gk=Gk** (k=i+1 to n) so that a rolling torque of a most upstream rolling mill R1 becomes equal to a stored G1*. Stabilization of material passage and improvement in accuracy of a product dimension are enabled by controlling tension between stands with high accuracy by using a simple control system without using table values or the like by each rolling condition even under a condition where a distance between stands is short.

Regarding each rolling mill, a rolling torque Gi before biting into a downstream stand is stored, the peripheral velocity of a most downstream stand Rn is controlled to be Gn1=Gn1* after biting into Rn, and a rolling torque Gn** of Rn after tension is stabilized is stored. After that, the peripheral velocity of a rolling mill Ri is controlled to be Gi=Gi* toward an upstream side, and the peripheral velocity of a rolling mill Rk at a downstream side of the rolling mill Ri is controlled to keep Gk=Gk** (k=i+1 to n) so that a rolling torque of a most upstream rolling mill R1 becomes equal to a stored G1*. Stabilization of material passage and improvement in accuracy of a product dimension are enabled by controlling tension between stands with high accuracy by using a simple control system without using table values or the like by each rolling condition even under a condition where a distance between stands is short.

A calibration determination device includes: a free roll that conveys the bonding member; a load detection device that detects a load applied to a bearing of the free roll; a tension adjustment device that winds the bonding member to increase a tension applied to the bonding member and unwinds the bonding member to reduce the tension applied to the bonding member so as to adjust the tension applied to the bonding member; and a calibration determination unit that determines whether calibration of the load detection device is necessary. The tension adjustment device unwinds the bonding member to cause the bonding member not to be subjected to the tension, and the calibration determination unit determines whether the calibration of the load detection device is necessary based on the load detected by the load detection device with the bonding member not being subjected to the tension.

A calibration determination device includes: a free roll that conveys the bonding member; a load detection device that detects a load applied to a bearing of the free roll; a tension adjustment device that winds the bonding member to increase a tension applied to the bonding member and unwinds the bonding member to reduce the tension applied to the bonding member so as to adjust the tension applied to the bonding member; and a calibration determination unit that determines whether calibration of the load detection device is necessary. The tension adjustment device unwinds the bonding member to cause the bonding member not to be subjected to the tension, and the calibration determination unit determines whether the calibration of the load detection device is necessary based on the load detected by the load detection device with the bonding member not being subjected to the tension.

A metal band is first rolled in a front and then in a rear (downstream) roll stand of a multi-stand rolling train. A looper between the roll stands may detect a band tension in the metal band. The band tension is supplied to a first and a second tension controller to determine an application additional target value and a speed additional target value. The second tension controller may only determine a value less than or greater than 0, as the speed additional target value, if the band tension is above or below an upper or lower band tension limit. Otherwise, the speed additional target value may be 0. The first tension controller is also supplied with a target tension that falls between the band tension limits. The application additional target value may be used to act on the rear roll stand.

A metal band is first rolled in a front and then in a rear (downstream) roll stand of a multi-stand rolling train. A looper between the roll stands may detect a band tension in the metal band. The band tension is supplied to a first and a second tension controller to determine an application additional target value and a speed additional target value. The second tension controller may only determine a value less than or greater than 0, as the speed additional target value, if the band tension is above or below an upper or lower band tension limit. Otherwise, the speed additional target value may be 0. The first tension controller is also supplied with a target tension that falls between the band tension limits. The application additional target value may be used to act on the rear roll stand.