Abstract:
A method of using data on the force flow in a press for the operation of a plunger, wherein the loads of the parts involved in the force flow can differ as a result of eccentrically operating forces, in such a way that the data about the respectively acting forces that, in accordance with Hooke's law, cause an extension or compression of a movement of the parts involved in the force flow, is measured and evaluated in relation to a drive device and a position of the plunger, whereupon a skewed position of the plunger is permitted or a skewed position of the plunger is counteracted or a skewed position of the plunger is set during operation of the press.
Abstract:
A slide motion control apparatus for a mechanical press comprising: a slide which is disposed so as to be relatively vertically movable with respect to a driven body to which a drive force is transmitted through a con rod of the mechanical press; a relative position commander that outputs a relative position command indicating a relative position of the slide with respect to the driven body; a relative position detector that detects a relative position of the slide with respect to the driven body, and outputs a relative position detecting signal indicating the detected relative position; a servomotor; a drive mechanism that relatively moves the slide with respect to the driven body by a drive force of the servomotor; and a controller that controls the servomotor based on a relative position command signal output from the relative position commander, and the relative position detecting signal output from the relative position detector.
Abstract:
A press has a fixed platen, a movable platen displaceable toward and away from the fixed platen, a plurality of low-pressure cylinders braced against the movable platen and pressurizable to move it toward the fixed platen, and a plurality of medium-pressure cylinders braced against the movable platen and pressurizable to move it toward the fixed platen. A low-pressure accumulator holding a body of hydraulic fluid and a head of nitrogen and a medium-pressure accumulator holding a body of hydraulic fluid and a head of nitrogen are connected via respective conduits with the low- and medium-pressure cylinders. a nitrogen supply connects the accumulators above the respective fluid bodies together in a closed system. A controller feeds the fluid therefrom to the respective cylinders. More particularly, the nitrogen supply includes a shunt conduit extending between upper regions of the accumulators and a pump or compressor in the shunt conduit for displacing nitrogen from the low-pressure accumulator to the high-pressure accumulator.
Abstract:
An electronic control system for operating the hydraulic cylinders associated with a press brake wherein independent control of each of the hydraulic cylinders is achieved to insure that the cylinders track against a fixed reference to insure more accurate forming of the workpiece. The cylinder tracking is under computer control which also establishes a creep speed slower than the normal forming speed near the point of ram reversal. A plurality of press brake may be operated simultaneously from the same tracking reference.
Abstract:
A hydraulic press such as a press brake is disclosed having a pair of long movable and fixed tools which are always kept in parallel with each other by detecting the obliquities of the movable and fixed tools and controlling the fluid delivery to hydraulic motors which drive the movable tool. Each hydraulic motor is controlled by a valve which is actuated by a rocking cam arrangement. The limit of movement of the movable tool toward the fixed tool also can be easily adjusted by adjusting the rocking cam arrangement.
Abstract:
A computer-controlled hydraulic press brake includes an actuator and control system which automatically provides variable pre-programmable ram opening and closing strokes. A microprocessor within the control system responds to stroke parameters entered by the operator and an encoder-generated signal indicative of ram position to generate a velocity command signal defining a velocity profile for positioning the ram to the stroke limits. Closed-loop servo systems associated with each ram cylinder respond to the velocity command signal to cause movement of the ram in accordance with the velocity profile. A ram leveling circuit responsive to individual position sensors associated with respective sides of the ram compensates for ram tilt by simultaneously applying complimentary correction signals to the respective servo systems. A second velocity profile may be generated in response to stored parameters to position a back gauge concurrently with ram movement by means of a second motor drive servo system.
Abstract:
A downstroke baler comprising a compaction chamber through which a platen is reciprocated vertically by spaced pressure actuated cylinders secured to opposite ends of the platen. The lower end of an actuating rod rests upon a support plate secured to the frame of the baler and a bracket secured to the frame of the baler is positioned adjacent the upper end of the actuating rod to restrain the actuating rod against vertical movement. A sleeve is secured to the platen and slides along the actuating rod such that the actuating rod is maintained perpendicular to the face of the platen. The upper end of the actuating rod is connected through an actuating link to valves secured to the frame of the baler. The valves control a hydraulic circuit connected to the cylinders which raise and lower the platen such that movement of the platen from a horizontal attitude causes the actuating rod to be moved from a vertical attitude thereby changing flow of fluid to the cylinders to return the platen to a horizontal attitude. The rod ends of the cylinders are in continuous communication with the source of pressurized fluid. A valve between the source of pressurized fluid and base ends of the cylinders is shiftable to a first position to direct pressurized fluid to the base ends of the cylinders to elevate the platen and is shiftable to a second position venting base ends of the cylinders to move the platen downwardly.
Abstract:
A device for driving in translatory motion the pressing element of a press, comprising a plurality of double-acting rams having their rods operatively connected to said pressing element said rams being hydraulically connected in series to each other, so that the driving of the piston of the first ram by a pressure fluid causes the rams to be fed by each other and the simultaneous sliding motions of their pistons, and means to keep constant the volume of hydraulic fluid contained in the front chamber of a ram and in the rear chamber of another ram with which it is connected.