A roll stack for the production of plastic sheeting uses a pneumatically-operated toggle joint, instead of a hydraulic press, to precisely separate two rollers. The pneumatically-operated toggle joint allows the rollers to be more quickly and safely further separated from each other in case there is an emergency.

A roll stack for the production of plastic sheeting uses a pneumatically-operated toggle joint, instead of a hydraulic press, to precisely separate two rollers. The pneumatically-operated toggle joint allows the rollers to be more quickly and safely further separated from each other in case there is an emergency.

When the deceleration start point is reached, the meter-in side of the hydraulic driving actuator is subjected to a flow rate control to thereby start the deceleration control processing. The position to which the movable unit is moved is detected to use a speed instruction corresponding to the movement position to subject the hydraulic driving actuator to a meter-in control. The position to which the movable unit is moved is detected to calculate the moving speed of the movable unit. Based on the speed instruction, the moving speed is subjected to the feedback control using the meter-out control to the hydraulic driving actuator.

When the deceleration start point is reached, the meter-in side of the hydraulic driving actuator is subjected to a flow rate control to thereby start the deceleration control processing. The position to which the movable unit is moved is detected to use a speed instruction corresponding to the movement position to subject the hydraulic driving actuator to a meter-in control. The position to which the movable unit is moved is detected to calculate the moving speed of the movable unit. Based on the speed instruction, the moving speed is subjected to the feedback control using the meter-out control to the hydraulic driving actuator.

A mold clamping device includes a base, a stationary platen, a movable platen, a mold clamping mechanism, a tie bar, and a half nut. This mold clamping device further includes a shaft supporting plate supporting a tip of the tie bar. This shaft supporting plate is fixed to the tip of the tie bar, and is mounted on the base so as to be freely movable.

When the deceleration start point is reached, the meter-in side of the hydraulic driving actuator is subjected to a flow rate control to thereby start the deceleration control processing. The position to which the movable unit is moved is detected to use a speed instruction corresponding to the movement position to subject the hydraulic driving actuator to a meter-in control. The position to which the movable unit is moved is detected to calculate the moving speed of the movable unit. Based on the speed instruction, the moving speed is subjected to the feedback control using the meter-out control to the hydraulic driving actuator.

When the deceleration start point is reached, the meter-in side of the hydraulic driving actuator is subjected to a flow rate control to thereby start the deceleration control processing. The position to which the movable unit is moved is detected to use a speed instruction corresponding to the movement position to subject the hydraulic driving actuator to a meter-in control. The position to which the movable unit is moved is detected to calculate the moving speed of the movable unit. Based on the speed instruction, the moving speed is subjected to the feedback control using the meter-out control to the hydraulic driving actuator.

A mold for production of cast parts, having two mold parts in the form of mold plates, which mold parts arc movable with respect to each other from an open position into a closed position, wherein the mold parts in their closed position define a mold cavity which may be filled with liquid casting compound and in their open position enable removal of a cast part which has solidified by at least partial cooling, and are lockable in their closed position by a locking device which joining the two mold parts so as to be releasable, and which mold parts may also be swung, wherewith in the closed position the locking device produces the locking of the mold plates with the stipulation that the locking pressure is maintained. The locking device has an energy storage means with a gas pressure spring for maintaining the closing pressure which presses the mold plates together after they have initially been pressed together.

In a mold clamping apparatus, a mold clamping mechanism is provided with a half nut, and a tie bar is provided with circumferential groove configured to meshed with the teeth of the half nut. A strong-force mold opening mechanism that opens molds at an initial stage of mold opening extends across a space separating a movable platen and the mold clamping mechanism and is connected to the movable platen and the mold clamping mechanism. The strong-force mold opening mechanism is set so as to have greater axial force and shorter stroke than those of a mold opening and closing mechanism. A control unit controls opening and closing of the half nut, controls the strong-force mold opening mechanism and controls the position of the half nut in such a way that the half nut is synchronized with the circumferential groove by the strong-force mold opening mechanism.

In a mold clamping apparatus, a mold clamping mechanism is provided with a half nut, and a tie bar is provided with circumferential groove configured to meshed with the teeth of the half nut. A strong-force mold opening mechanism that opens molds at an initial stage of mold opening extends across a space separating a movable platen and the mold clamping mechanism and is connected to the movable platen and the mold clamping mechanism. The strong-force mold opening mechanism is set so as to have greater axial force and shorter stroke than those of a mold opening and closing mechanism. A control unit controls opening and closing of the half nut, controls the strong-force mold opening mechanism and controls the position of the half nut in such a way that the half nut is synchronized with the circumferential groove by the strong-force mold opening mechanism.