US 5,587,633 A · Press control method and press apparatus

Abstract

It is an object to obtain a press apparatus and a press controlling method which apply press working to a processed object with accurate press load and is capable of press working with accurate press load without affected by variations in thickness of the processed objects and variations in shut height of molds. A servo motor (51) is connected concentrically to a rotation transmitter (52), and a screw shaft (53) is provided passing through the center of the rotation transmitter (52). The driving force of the servo motor (51) is converted into a thrusting force of a press ram (54) by combining the rotation transmitter (52) and the screw shaft (53). Correct press load is applied to the processed objects and troubles in the press processing caused by variations in thickness of the processed objects can be prevented.

Claims12

Dependent claims

A press control method for a press apparatus which converts a driving force of a motor into a thrusting force of a mold through driving force--thrusting force converting means directly connected to said motor to press a processed object, comprising the steps of:

(a) detecting a change of a torque value of said motor attendant on press processing of said processed object and determining whether a previously set predetermined torque value smaller than a target rated torque value is reached or not;
and
(b) after reaching said predetermined torque value, counting the quantity of drive of said motor, comparing deceleration pattern which is previously set as a function of speed and the quantity of drive and the counted quantity of drive of said motor and decelerating thrusting speed of said mold on the basis of a speed instruction applied according to the quantity of drive of said motor so that the thrusting speed of said mold attains zero at the time when the quantity of drive of said motor achieves a previously set predetermined quantity of drive.

A press apparatus which converts a driving force of a motor into a thrusting force of a mold through driving force--thrusting force converting means directly connected to said motor to press a processed object, comprising:

torque value detecting means connected to said motor, for detecting a change of a torque value of said motor caused in press processing of said processed object;
torque value comparing means connected to said torque value detecting means, for making a comparison and determining whether the detected torque value is a previously set predetermined torque value which is smaller than a target rated torque value or not;
drive quantity counting means connected to said motor for counting the quantity of drive of said motor;
and
controlling means connected to said torque value comparing means and said drive quantity counting means, for storing deceleration pattern previously set as a function of speed and the quantity of drive and comparing the quantity of drive of said motor outputted from said drive quantity counting means and said deceleration pattern to output speed instructions according to the quantity of drive of said motor so as to decelerate the thrusting speed of said mold, so that after reaching said predetermined torque value, the thrusting speed of said mold attains zero at the time when the quantity of drive of said motor achieves a previously set predetermined quantity of drive.

2 more elements

Dependencies are inferred from the claim text.

Press control method and press apparatus

Life of this patent

Press control method and press apparatus

Life of this patent

Abstract

Claims12