Patent ID: 9737940
Date: 2017-08-22
CPC Classifications: B23D,Y10T

Claim:
1. A circular cutting machine comprising: (1) a headstock transfer unit for transferring a headstock between a standby position and a cutting position, the headstock mounting a circular saw motor for rotatably driving a circular saw blade; (2) a transfer vice unit for feeding a work by advancing the work toward the cutting position; (3) a main vice unit for clamping the work forward and rear of and across the cutting position; (4) a fixed length cutting controller for drivably controlling the circular saw motor, the headstock transfer unit, the transfer vice unit, and the main vice unit to perform fixed length cutting of the work; and (5) work end detection sensors for detecting a rear end of the work; wherein: (a) the main vice unit comprises a rear vice and a front vice, the rear vice being fixed in forward and rearward directions in a prescribed position rear of the cutting position and the front vice having, as a preset position thereof during cutting, a prescribed position forward of and across the cutting position from the rear vice, the front vice being movably disposed in the forward and rearward directions in a range between a position forward of its preset position and a rearmost position where rear ends of jaws of the front vice are in contact with front ends of jaws of the rear vice, the front vice and the rear vice including separate clamping cylinders capable of being independently controllable so that the front vice performs clamping and unclamping independently of clamping and unclamping by the rear vice; (b) the fixed length cutting controller comprises a processor and a storage device, the processor being configured to execute computer program processes, comprising a fixed-length cutting process, a determination process, a work pullout process, and a work remainder cutting process; (c) the fixed length cutting process is for cutting the work to a fixed-length, and when executed by the processor configures the fixed-length cutting controller to perform the following: (d) the determination process configures the fixed-length cutting controller to calculate a remaining length of the work currently undergoing fixed length cutting based on detection signals from the work end detection sensors and determines whether or not the remaining length has become insufficient to permit the transfer vice unit to advance the work the fixed length feed amount; (e) when the determination process determines that the remaining length of the work has become insufficient to permit the transfer vice unit to advance the work the fixed length feed amount, the work pullout process is executed configuring the fixed-length cutting controller to cause the front vice to retract to the rearmost position while the front vice and rear vice remain unclamped from the work, and then cause the front vice alone, without the rear vice, to clamp and advance the work a predetermined pullout amount so as to position the work, which can no longer be fed the fixed length, forward of the cutting line the length equivalent to the fixed length feed amount; and (f) after the work pullout process causes the front vice to pull out the work, the work remainder cutting process is performed, which configures the fixed-length cutting controller to perform the following: