The present invention relates to a system for generating a numerical control information which generates a numerical control information when blanks are machined by numerically controlled machines.
So-called numerical control systems which automatically control machines and tools with numerical control information comprising numerals and codes have been widely used and greatly contributed to the automation in processing, and reduction of the machining cost and time.
In such a numerical control system, it is necessary to input information for the numerical control prior to machining. In order to simplify the step, there has widely been used a numerical control information generating system which receives data in an interactive mode and generates a numerical control information. By using the numerical control information generating system of this type, such information for the numerical control may be generated for machining simply by inputting the material and shapes of blanks, and the machining methods (i.e. machining region, cutting directions, cutting tools, cutting conditions, machining order, etc). Recently there has been proposed a numerical control information generating system which can automatically determine a machining method and generate the numerical control information simply by inputting the blank shapes and the part shapes.
The present applicant has proposed a numerical control information generating system which can automatically determine the machining methods (see Japanese Laid-open Patent No. 65945/1990), an embodiment of which being shown by the block diagram of FIG. 1.
The numerical control information generating system comprises a processor (CPU) 1 which controls the whole system, a control memory 2 which stores programs for controlling the system, and a blank shape/part shape memory 3 which stores information on the blank shapes and the part shapes. The system also includes a machining step table registering memory 4 for registering a machining step table which stores the information on the machining steps, a display unit 5 which displays processing procedure information and the like, and an operation board 6 which receives as an input the blank shapes and the part shapes. It further comprises a temporary memory 7 which stores temporarily the information such as graphic element columns and the like, a numerical control information storing memory 8 for the numerical control information which stores information for the numerical control, and a parameter memory 9 which stores parameters for selecting a machining method. These above component parts may exchange information with each other through a bus line BL.
FIG. 5 shows an example of a blank shape and a part shape. The flowchart of FIG. 2 explains the process under which the above mentioned numerical control information generating system determines whether it should select a face machining or a longitudinal machining in order to obtain the process from a blank shape into a part shape.
A judgement is made as to whether or not an inclination A with respect to the X-axis of a graphic element e.sub.2 which forms a part shape within the region R which is inputted by an operator as the region requiring machining is within a parameter .theta..sub.p (Step S101). If it is judged that the inclination A is not within the parameter .theta..sub.p, the graphic element e.sub.2 is determined to be the object of longitudinal machining (Step S105) and the whole process terminates and is thereby completed. If it is judged, on the other hand, that the inclination A is within the parameter .theta..sub.p, a judgement is made as to whether or not the length L of the graphic element e.sub.2 inputted by the operator in relation to the X-axis is longer than the parameter L.sub.p registered in the parameter memory 9 (Step S102). If it is judged that the length L is not longer than the parameter L.sub.p, the graphic element e.sub.2 is determined to be object of the longitudinal machining (Step S105) and the process is thereby completed.
On the other hand, if it is judged that the length L of the X-axis is longer than the parameter L.sub.p, a rectangular region constituting of the graphic element e.sub.2 and the blank shape is generated, and a judgement is made as to whether or not the cutting stock D in the direction of the Z-axis (longitudinal direction) inputted by the operator is smaller than the parameter W.sub.p registered in the parameter memory 9 (Step S103). If it is judged that the cutting stock D is not smaller than the parameter W.sub.p, the graphic element e.sub.2 is determined to be the object of the longitudinal machining (Step S105) and the whole process is thereby completed. If the cutting stock D is smaller than the parameter W.sub.p, the graphic element e.sub.2 is determined to be the object of face machining (Step S104) and the whole process is completed.
The above mentioned conventional numerical control information generating system determines a graphic element as the object of the face machining only when all the conditions in the Steps 101, 102 and 103 shown in FIG. 2 have been satisfied. A judgement as to whether or not each of those conditions is satisfied is made independently in each step based on the parameters inputted in advance. Therefore, if the inclination and the length of a graphic element satisfy the conditions of Steps S101 and S102, and if the parameter W.sub.p at the Step S103 is 20 [mm], and the cutting stock D of the rectangle formed with the graphic element and the blank shape is 20 [mm], the condition in the Step S103 is satisfied, too. Then the graphic element becomes the object of the face machining. However, if the cutting stock D is 20.001 [mm], it does not satisfy the condition of the Step S103, the graphic element becomes the object of the longitudinal machining.
In the conventional system a graphic element is compared with parameters separately in each step, and if there is one step which does not quite satisfy a condition, then the graphic element is judged as an object of a longitudinal machining instead of a face machining. However, when an operator judges with his/her discretion whether it should be the longitudinal machining or the face machining, he/she judges factors at each step not only separately but comprehensively, and even if one condition in a step is not quite satisfied by a small margin, he/she may judge the graphic element to be the object of the face machining. The judgement given automatically by the system therefore does not always agree with what would be made by operators.