摘要:
An oil circuit in which a meter-in circuit and a differential circuit are combined is disposed. Oil is supplied from a variable capacity pump (1) in order to make a mold opening/closing control apparatus operate. A position instruction signal (Xe ref ) obtained by integrating a velocity instruction signal (dXe ref /dt) and a positional deviation (Xe ref -Xe) of the displacement of the mold opening/closing control apparatus are obtained. A flow-rate instruction signal (q ref ) is set by the positional deviation. Then, a differential switching determining section (12) receives the positional deviation and determines differential switching, following which a differential change-over valve (5) switches between the meter-in circuit (II) and the differential circuit (I). With a gain switching section (13) connected to the differential switching determining section (12), the gain switching section (13) switches between a pump gain (PG1) for the meter-in circuit and a pump gain (PG2) for the differential circuit. The above variable capacity pump (1) is controlled by the switched pump gain. A fixed capacity pump (21) may be connected to the variable capacity pump (1) and used. In such a case, switching between un-load and on-load is performed in response the reception of a flow-rate instruction signal from the gain switching section.
摘要:
A method and apparatus for controlling the stroke of a press in which the movements of two portions of a movable platen (28; 128) of the press are continuously sensed during a stroke. A signal is generated whose magnitude at any time during a stroke is dependent on the sum of the distances moved by the two portions of the movable platen (28; 128) during the stroke. The signal is compared with a preselected value which is selected in accordance with the length of the stroke required and the stroke is terminated when the magnitude of the signal equals the preselected value.
摘要:
Eine hydraulische Presse besitzt einen Arbeitszylinder (11), in dem ein Hauptkolben (12) verschieblich aufgenommen ist, der im Inneren des Arbeitszylinders (11) zumindest eine Kammer (11a) definiert. Das Volumen der Kammer (11a) ändert sich in Abhängigkeit von der Bewegung des Hauptkolbens (12), wobei der zumindest einen Kammer (11a) eine Befüllvorrichtung (13) zugeordnet ist, mittels der der Kammer (11a) bei sich vergrößerndem Volumen Hydraulikflüssigkeit über eine Befüllleitung (14) zuführbar ist, in der ein 1. Absperrventil (15) sitzt, das in einem Ventilgehäuse (16) angeordnet ist. Um einen kompakten Aufbau zu erzielen, ist in dem Ventilgehäuse (16) ein Rückführungskanal (28) ausgebildet, durch den Hydraulikflüssigkeit aus der Kammer (11a) abführbar ist, wobei in dem Rückführungskanal (28) ein 2 Absperrventil (24) angeordnet ist.
摘要:
A servo-drive system of a press, wherein a pair of servo-motors (30a, 30b) as the power sources of a ram (22) capable of generating a necessary ram pressure by using a torque obtained by synthesizing the same torques based on speed-torque characteristics are mirror-images of each other and installed, opposite to each other, at both ends of an operating shaft (20) vertically moving the ram (22), whereby the operating shaft (20) can be directly driven by operating the pair of servo-motors (30a, 30b) as an integral part.