Hydraulic extension cushion with planetary roller screw driven by alternating-current servo synchronous motor

Abstract

Disclosed is a hydraulic extension cushion with a planetary roller screw driven by an alternating-current servo synchronous motor. A pneumatic control valve core structure of a core mechanism controlling blank holding force is replaced by a valve core structure driven by the alternating-current servo synchronous motor, and the valve core structure is higher in accuracy and responding speed; the structure is simple and compact, and the failure rate is low; the valve core structure design has a buffering capacity, the problem of too large blank holding force at the initial moment of stamping can be solved, and meanwhile, a main valve core is protected against damage. A pressure sensor is arranged in a piston cavity, and the alternating-current servo synchronous motor can be adjusted conveniently according to instantaneous pressure conditions, accordingly valve core displacement is controlled accurately, accurate control over the blank holding force is achieved, and the whole forms a closed loop system. The alternating-current servo synchronous motor drives a screw to rotate through deceleration, then the rotation is converted into the linear motion of the valve core through a planetary roller pair, the alternating-current servo synchronous motor is used for controlling the displacement of the valve core in a closed-loop mode, and accordingly accurate blank holding force adjustment can be achieved.

Description

Technical field [0001] The invention belongs to the technical field of press stretch pads, and in particular relates to a hydraulic stretch pad with an AC servo synchronous motor driving a planetary roller screw. Background technique [0002] In the production of sheet metal drawing process, it is often necessary to press the edge of the workpiece to prevent wrinkles. Small presses are always equipped with spring or rubber edge holding devices. The holding force provided by this kind of edge holding device cannot be too large and cannot be adjusted; in large or deep drawing, air cushion or hydraulic air cushion is often used. The traditional hydraulic air cushion uses a hydraulic cylinder as a support cushion, and the hydraulic oil in and out of the hydraulic cylinder is determined by a working valve stem controlled by air pressure. The air distribution valve is used to control the piston in the cylinder, thereby controlling the movement of the working valve rod connected to the...

AI Technical Summary

Problems solved by technology

The structure of this hydraulic air cushion is complicated, and the manufacturing workload is large.

Moreover, it is difficult to precisely control the position of the valve stem controlled by air pressure, and it is impossible to quantitatively control the size of the valve opening, and it is also impossible to accurately control the size of the blank holder force.

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