Abstract: A servo drive system of a press machine includes a ram, an operation shaft which vertically moves the ram, and a servo motor which operates as a power source of the ram and which generates ram pressure using a torque based on at least one speed-torque characteristic of the servo motor. The operation shaft is directly driven using the servo motor. The at least one speed-torque characteristic of the servo motor is set in a manner such that a motor torque of the servo motor at which a capacity of electric energy supplied by a servo amplifier is determined becomes the motor torque at which an optimal punching pattern of the ram is generated from a light load to a heavy load according to a type of workpiece to be worked by the press machine.

Abstract: A continuous working system of a press machine includes a ram, an operation shaft which vertically moves the ram, and a servo motor which operates as a power source of the ram and which generates ram pressure using a torque based on at least one speed-torque characteristic of a motor. The operation shaft is directly driven using the servo motor. The operation shaft is continuously reciprocated and turned through an angle range corresponding to a distance between a predetermined lower end position required for press working by the ram and an upper end position such that the ram vertically moves between these positions by the servo motor, thereby subjecting a work to a continuous press working. The upper end position is set to a position slightly below a medium height of the entire vertically possible stroke of the ram. The lower end position is set to a position slightly above a bottom dead center of the entire vertically possible stroke of the ram.

Abstract: A servo drive system of a press machine has a pair of servo motors which can generate necessary ram pressure by compositing and using a torque based on the same speed-torque characteristics. The servo motors are symmetric with each other in a mirror image manner. The servo motors are opposed to each other at opposite ends of an operation shaft which vertically moves a ram. The servo motors are integrally operated, thereby directly driving the operation shaft.

Abstract: A press drive unit and press drive method are provided which decrease the cycle time of a press to improve its productivity, enable use of small-sized, inexpensive presses and provide improved product quality. To this end, the press drive unit comprises a drive shaft coupled to a slide through a specified power transmission mechanism; a first drive system for rotationally driving a flywheel with a main motor and driving the drive shaft through a clutch disposed between the flywheel and the drive shaft; and a second drive system for driving the drive shaft at variable speed with a sub motor. Driving is carried out with the first and second drive systems in a formation zone, and driving is carried out with the second drive system alone in a non-formation zone.

Abstract: In a press production series for massive forming with a toggle drive for driving a ram, varying stroke speeds of the ram motion are attached by adjustment of cogwheels of an planetary gear system having fixed connecting dimensions. Uniform machine frames can thus be used.

Abstract: A high precision, all-purpose, double action hydraulic press, which can control the speed, position, and parallelism of each slide, can conduct mold exchanges easily, and prevent the breakthrough phenomenon is provided with an outer slide 4, an inner slide 6, drive cylinders 8 and 9 which drive each of the slides, position detection devices 14 and 15 which detect the position of each of the slides, push pins 13, a damper cylinder 10 which prevents breakthrough phenomenon, and a die plate 5 which is equipped with push pins 13. By controlling the flow in the hydraulic pressure circuit which is connected to each of the drive cylinders, the speed, position, and parallelism of each of the slides are controlled.

Abstract: A material eject system includes an ejector mounted to a bed of a vehicle which is movable between a rear end and a forward end of the bed for ejecting material from the bed. The ejector is powered by a cylinder having different fluid volumes depending on the direction of motion of the cylinder. A control circuit operates with the ejector motor to automatically move the ejector through eject and return cycles. Further, the control circuit detects different positions of the cylinder and automatically operates the cylinder at different speeds to maintain a constant motor and ejector speed throughout the material eject cycle.

Abstract: With a method of controlling synchronous drive of a plurality of pressing machines, each of the pressing machines has a motor, a drive shaft to which a torque of a flywheel driven by the motor is transmitted through a clutch and a slide driven by the drive shaft so that a rotational position of the drive shaft of each of the pressing machines is synchronous each other. The method has a step of detecting actual velocity information of the motor and a step of detecting actual rotational-position information of the drive shaft. The detected actual rotational-position information is compared with the reference rotational-position information from a reference rotational position information generating section. Based on the result of the comparison, the reference velocity information from a reference velocity information generating section is compensated into characteristic reference velocity information of each of the pressing machines.

Abstract: A hydraulic press has closed loop feedback control on a slide, a slide pad and bolster cylinders. Hydraulic cylinders actuating various components of the press are controlled according to ideal position estimates to produce consistent and precise pressing action. A closed loop control consists of an ideal position/pressure value generator, a position/pressure detector and an arithmetic unit comparing the ideal and actual position/pressure values. Using the ideal and actual comparison result, the arithmetic unit produces a control signal to drive a cylinder to a desired position/pressure. The hydraulic press is capable of performing several operations on a workpiece in one press cycle, an improvement over presses requiring several operation steps or die changes. The bolster cylinders augment clamping force, reduce shock, and improve die alignment to produce better results with less wear on press components.

Abstract: A ram driving device for a press machine having: a ram; a horizontal drive axle (33) rotatably provided horizontally in a frame (3) of the press machine; a motion converting mechanism (35, 63, 83) associated with the horizontal drive axle, for converting a rotational motion of the horizontal drive axle into up-and-down motion of the ram (29); and a plurality of servomotors (43, 47) linked with the horizontal drive axle, for rotating the horizontal drive axle in synchronism with each other, to drive the ram up and down. The motion converting mechanism is a connecting rod (35); and a link mechanism (63) driven by a ball screw (61) and a nut member (77); and an eccentric ring cam (33) and a cam follower (91). Since the ram can be driven by a plurality of the servomotors synchronously, the device can generate a large press power of various moving stroke and various moving speed freely, without increasing the maintenance cost thereof.

Abstract: A compression molding apparatus adaptable for instantaneously applying a large pressurizing force in the final stage of compression molding having a simple design and at low cost. A gear is provided to a screw shaft for rotating through a pair of pinions by a pair of hydraulic motors, and a plunger compresses a composite material. In the final stage, by using a pair of pressure-mounting actuators provided in a pressure-mounting system, a compressed deformation takes place to instantaneously apply pressurizing force through the gear to the screw shaft by a torque arm and a lock-piece respectively.

Abstract: A hydraulic closing unit, particularly for injection molding machines which process plastics material. The closing unit includes a mold clamping plate which is slidably guided on guide columns between a stationary support plate and a stationary mold clamping plate. An annular main piston acts on the slidable mold clamping plate with a high mold closing force in mold closing direction. The main piston is axially slidably guided in the stationary support plate and load can be applied to both sides of the main piston. At least two coupling planes are provided between the main piston and the central pressure column. The coupling planes are mounted spaced apart and one behind the other in sliding direction of the slidable mold clamping plate. The main piston and the pressure column are slidable relative to each other over the distance range between the coupling planes.

Abstract: A clamping system for traversing and clamping molds in a molding machine, the clamping system including a toggle-type clamp arrangement defined by a plurality of pivotally connected links. A movable crosshead is carried on a crosshead guide, and a ball screw is non-rotationally secured to the movable crosshead to extend in the direction opposite from the face of a cooperating fixed mold portion. A pair of ball nuts are carried by the ball screw and each of the ball nuts is drivingly connected with a respective servomotor. One of the servomotors is adapted to provide rapid traverse movement for the movable crosshead, and the other servomotor is adapted to provide high torque for high clamping force to hold a pair of mold halves in tightly contacting relationship during the injection into a mold cavity defined by the mold halves of a flowable material under pressure.

Abstract: A clamping mechanism which includes a cylinder and a piston. The diameter of the piston is less than the internal diameter of a rear chamber of the cylinder such that fluid flows around the piston when the piston moves from an open position to an intermediate position. The diameter of the piston is equal to the internal diameter of a front chamber of the piston such that fluid cannot flow around the piston when the piston moves from the intermediate position to a closed position. To prevent cavitation within the cylinder, fluid is charged to the cylinder in accordance with the movement of the piston.

Abstract: A motor-operated, direct-pressure type mold clamping apparatus is capable of high-speed mold closing and opening operations and of producing a required mold clamping force, without the use of a large-sized motor. In the mold opening and closing operations, a ball screw, in engagement with a ball nut which is movable in one with a moving platen, is rotated at high speed by a motor through gears and a clutch, so that a die is opened and closed at high speed. In a mold clamping operation, the ball screw is driven with a large rotatory force transmitted through a clutch and gears which, having a high reduction ratio, serve to increase the rotatory force of the motor. Thus, dies are clamped with a large clamping force.

Abstract: A motor-operated, direct-pressure type mold clamping mechanism capable of high-speed mold closing and opening operations and of producing a required mold clamping force, without the use of a large-sized motor. In the mold opening and closing operations, a ball screw, in engagement with a ball nut which is movable in unison with a moving platen, is rotated at high speed by a coarse-adjustment motor through gears, so that a die is opened and closed at high speed. In the mold clamping operation, the ball screw is driven by a fine-adjustment motor through a clutch and gears which, having a high reduction ratio, serve to enhance the rotatory force and provide greater clamping force.

Abstract: A mold clamping device is disclosed. The device includes a clamping ram, whose front end is connected to a moveable board of an injection molding machine, slidably fitted in a clamping cylinder, and a support cylinder provided in parallel to the clamping cylinder. A support piston is slidably positioned in the support cylinder, and the front end of the rod of the support piston is connected to the moveable board of the injection molding machine. A front chamber and a rear chamber of the clamping cylinder, divided by the piston section of the clamping ram, and a front chamber of the support cylinder are connected by an oil path. There is provided a valve for opening or closing the connection between the rear chamber of the clamping cylinder and the front chamber of the clamping cylinder and the front chamber of the support cylinder.