Bending machine

Abstract

A bending machine includes a frame, a punch holder provided on the frame, a die holder provided on the frame, a pressing mechanism for pressing a punch toward a die, a first deflection detector for detecting a stroke of the punch, a second deflection detector for detecting an actual displacement of the punch, and a controller; and the controller previously stores a relation between a deflection of the frame and a specification of a sheet material, calculates an actual deflection of the frame by subtracting a detection value of the second deflection detector from a detection value of the first deflection detector, gets a target deflection of the frame based on the relation stored, and controls the pressing mechanism so that the actual deflection becomes consistent with the target deflection. According to the bending machine, working efficiency can be improved by rendering a trial bending unnecessary.

1 . A bending machine comprising:
 a frame that includes a base section, and a punch-side frame section and a die-side frame section that are extended from both sides of the base section in an identical direction, respectively;   a punch holder that is provided on the punch-side frame section and to which a punch is attached;   a die holder that is provided on the die-side frame section and to which a die is attached;   a pressing mechanism that presses the punch toward the die to bend a sheet material between the die and the punch;   a first deflection detector that is provided in the pressing mechanism and detects a stroke of the punch required for bending the sheet material;   a second deflection detector that is supported by the die-side frame section and detects an actual displacement of the punch; and   a controller operable to previously store a relation between a deflection of the frame and a bending length, material and a sheet thickness of a sheet material, to calculate an actual deflection of the frame by subtracting a detection value of the second deflection detector from a detection value of the first deflection detector, to get a target deflection of the frame for bending a sheet material to be bent based on the relation stored, and to control the pressing mechanism so that the actual deflection becomes consistent with the target deflection.   
     
     
         2 . The bending machine according to  claim 1 , wherein
 the pressing mechanism includes a motor for pressing that moves the punch toward the die,   the first deflection detector is an encoder that detects rotations of the motor, and   the second deflection detector is a scale that is supported by the die-side frame section via a support frame.   
     
     
         3 . The bending machine according to  claim 1 , wherein
 the controller includes a deflection calculator that calculates the actual deflection of the frame from detection results of the first deflection detector and the second deflection detector, and a memory for storing a data table in which the relation is defined.