NC Data Creation Method

1. Technical Field L This invention relates to an NC data creation method and, more particulary, to an NC data creation method in which a command statement is inserted after a T-code for tool selection.

2. Background Art

An automatic programming system is available in which a conversational screen conforming to each step of a plurality of data input steps is displayed on a display unit and NC statements (NC data) executable by an NC unit are created using data entered while referring to the conversational screens. For example, see U.S. Pat. No. 4,723,203 ("Machining Process Determination Method in Automatic Programming"). Such an automatic programming system includes the following steps, which will be described with reference to FIG. 6:

(1) a first step of selecting execution of "automatic programming";

(2) a second step of selecting data to be entered (step to be executed next)

(3) a third step of selecting a blank material;

(4) a fourth step of selecting surface roughness;

(5) a fifth step of selecting design drawing format;

(6) a sixth step of entering blank profile and its dimensions;

(7) a seventh step of entering a part profile and its dimensions;

(8) an eighth step of entering machine origin and turret position;

(9) a ninth step of selecting a machining process;

(10) a tenth step of selecting a tool and entering tool data;

(11) an 11th step of deciding machining conditions;

(12) a 12th step of entering cutting direction

(13) a 13th step of entering cutting limits;

(14) a 14th step of entering whether there is an area cut by the same tool; and

(15) a 15th step of calculating tool path (i.e., of creating an NC data statement).

In accordance with these steps, predetermined prompts (conversational screens) are successively displayed on a display screen, the operator enters the required data from a keyboard in response to these prompts and finally an NC statement is created using all of the entered data. It should be noted that the conversational inputs from the ninth step to the 14 step are made repeatedly until all machining process data have been entered.

The NC statement created by the foregoing method has NC statements MP1, MP2, ... MPn (see FIG. 7) for machining processes entered in sequence by repeating the ninth through 14th steps. Specified in each NC statement for a machining process are NC data (G50X.sub.-- Y.sub.--) for setting a coordinate system, a T-code (T.sub.--) for selecting a tool, and NC data (G01X.sub.-- Y.sub.-- ;..) for a tool path.

With this conventional NC statement format, however, it is difficult to tell merely from looking at the NC statements what tool is being used for what process; hence, checking and revising the NC statements is not easy. Further, the tool number.sub.-- in the T-code (T.sub.--) for tool selection indicates the tool position on a turret on which a plurality (six to ten) tools are mounted. Since it is not known whether the same tool will always be mounted at the same position on the turret, one cannot immediately tell merely from looking at the T-code of the NC statement what the tool is.

Accordingly, an object of the present invention is to provide an NC data creation method wherein the type of a tool, the process in which the tool is used, etc., can be recognized merely by looking at an outputted NC statement, and wherein it can be readily ascertained what part of an NC statement is for a machining process and what the process is.

In an NC data creation method according to the invention, a comment statement is inserted after a T-code for tool selection, the comment statement including information relating to a tool in the T-code and/or information relating to a machining process performed by the tool.

FIG. 1 is a view for describing the general features of the present invention;

FIG. 2 is a block diagram of a system for practicing the method of the invention;

FIG. 3 is a table for describing a tooling file;

FIGS. 4 and 5 are views for describing a machining process file;

FIG. 6 is a flowchart of automatic programming processing; and

FIG. 7 is a view for describing conventional NC statements.

FIG. 1 is a view for describing the general features of the present invention.

Numeral 1 denotes an NC statement, MP1, MP2, ... represent NC statements for respective machining processes, TC1, TC2 designate T-codes for selecting tools, and CMS1, CMS2 denote comment statements.

The comment statements CMS1, CMS2 are inserted after the tool selection T-codes TC1, TC2 of the NC statement 1 created based on data entered via a plurality of data input steps, each of the comment statements CMS1, CMS2 comprising information relating to the tool of the T-code and/or information relating to the machining process performed by the tool. This information is enclosed in brackets.

When an NC statement is outputted (printed out, displayed, etc.), the statement is outputted inclusive of the comment statement, which is ignored when numerical control is performed.

FIG. 2 is a block diagram of a system for practicing the method of the present invention. Numeral 11 denotes an automatic programming unit, 12 an NC control unit, 13 a graphic display unit (CRT), 14 a keyboard, 15, 16 changeover units, 17 a data input/output unit, 18 a program storing medium such as a bubble cassette memory, and 21 a machine tool.

The automatic programming unit 11 and NC control unit 12 are constituted by microcomputer and incorporate a processor, a control program memory (ROM) and a RAM. A RAM 11a of the automatic programming unit 11 stores a tooling file TF, workpiece file WF, a created family program FMF and NC statements, etc. An NC data statement on the basis of which NC control is presently being performed is stored in a RAM 12a of the NC control unit 12.

As shown in FIG. 3, the tooling file TF is such that tool numbers of tools, tool revision numbers, tool nose radii, blade angles and mounting angles correspond to tool management numbers ID.

In the automatic programming mode, a family program is created by entering data necessary for NC statement creation in accordance with the first through 14th steps shown in FIG. 6, just as in the prior art. The family program is stored in the RAM 11a. It should be noted that the data stored in the RAM include a machining process file created by repeating the ninth through 14 steps of FIG. 6. As shown in FIG. 4, the machining process file includes, for every machining process, a process number, a machining type (machining process name), tool data, machining conditions and machining area data. These are arrayed in the order of the entered machining processes. After all data have been entered, NC data are created in the 15th step of FIG. 6. When a tool selection T-code is outputted in this case, tool information (e.g., tool management number) and the machining process are obtained by referring to the machining process file, and these are outputted as a comment statement enclosed in brackets. It should be noted that rough machining of outer diameter is expressed by OUT-ROUGH, rough machining of inner diameter by IN-ROUGH, end-face rough machining by FACE-ROUGH, and finishing machining of outer diameter by OUT-FIN, etc.

Assume by way of example that rough machining of outer diameter and rough machining of inner diameter are designated as first and second machining processes, respectively, and that tool management numbers 100, 110 (see FIG. 3) are designated as the tools used in these processes, respectively. The automatic programming unit 11 will then create a machining process table (only a part of which is shown), as illustrated in FIG. 5, by obtaining the tool numbers and tool revision numbers by referring to the tooling file, and, at the time of NC data creation, will output the NC statement 1 having the comment statements CMS1, CMS2 inserted after the tool selection T-codes TC1, TC2, as shown in FIG. 1, by referring to the machining process file. In numerical control, the comment statements enclosed in brackets are ignored.

Thus, in accordance with the present invention, the arrangement is such that a comment statement is inserted after a T-code for tool selection, the comment statement including information relating to a tool in the T-code and/or information relating to a machining process performed by the tool. As a result, the type of a tool, the process in which the tool is used, etc., can be recognized merely by looking at an outputted NC statement, and it can be readily ascertained what part of an NC statement is for a machining process and what the process is.