JPH07136900A - Numerically controlled machining method - Google Patents

Abstract

PURPOSE:To efficiently provide a highly precise machined product by machining an object to be machined in the direction, in which a curvature of a machined face of the machined product is the predetermined value or less, on the basis of the first tool locus data, and then, machining the object in the direction crossing at right angles with the machining direction on the basis of the second tool locus data. CONSTITUTION:In machining of a press die 2 or the like, firstly in the first step, a machining area is set so that a curvature of a machined face to at least one direction of a machined product is the predetermined value or less, and secondly in the second step, the first tool locus CL1 data which is approximately parallel to one direction is set on the basis of a shape data of the machining area. Thirdly in the third step, a locus direction crossing at right angles with the locus direction of the first tool locus data is set as the second tool locus CL2 data, and then, the first and the second tool locus data are converted into NC machining data. After an object to be machined is machined on the basis of the NC machining data based on the first tool locus data, the object to be machined is machined on the basis of the NC machining data based on the second tool locus data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to, for example, when machining a press die, after machining the press die in the direction of smaller curvature by the first tool trajectory data, the second tool trajectory data is used to The present invention relates to an NC working method for obtaining a high-quality press die by working in a direction orthogonal to the working direction.

[0002]

2. Description of the Related Art Machining using an NC controlled machine tool (NC device) is widely performed in various manufacturing plants. For example, in an automobile production plant, processing using an NC device is performed in various steps, and the NC device is also used for processing a press die for producing a sheet metal part such as a panel.

On the other hand, computer-aided design systems / computer-aided manufacturing systems (CAD / CAM systems) have been generally adopted along with the progress of automation and mechanization of design and manufacturing, and CAs according to respective industries and jobs.
A D / CAM system is provided. When processing is performed by the NC device, the shape data created by using such a CAD / CAM system is used, and a predetermined conversion process is applied to this to create NC processed data.

Here, the NC created as described above
When performing external processing of a press die or the like using an NC device based on the processing data, generally, a tool such as a ball end mill or a flat end mill is used as a machining center (M /
According to C), grinding and cutting are performed while appropriately replacing. At this time, the physical specifications such as the tool type, diameter, and blade length are selected depending on the part or shape to be machined or the machining process such as rough machining, medium machining, and finish machining, and the CAD system is used with these as parameters. Tool trajectory data is calculated based on the shape data created above and converted into NC processing data.

[0005]

By the way, when calculating the tool trajectory data, in addition to the physical specifications of the tool to be used, the material (material) of the die to be processed by the NC device, the processing method, and the processing are specified. It is necessary to generate an optimum tool locus in consideration of specifications of the NC device to be performed. Here, the optimum tool locus means that the amount of uncut material is small and the manual work of the operator in the finishing process can be reduced, the load on the tool is small, and efficient machining is possible without damaging the tool. Means a locus.

FIG. 7A shows a tool 1 such as a ball end mill.
2 is a conceptual illustration of the tool locus CL when the die 2 is shaped. In this case, as shown in FIG. 7B, when the tool locus is set so as to reciprocate the tool 1 in the curved direction of the machining surface of the mold 2 (direction of arrow b),
In particular, the cutting direction (axial direction of the tool 1) receives a large cutting resistance in a portion having a large inclination close to the moving direction of the tool 1 (direction of arrow b), and in that case, the tool 1 may be damaged. is there. Therefore, the tool locus CL is set so that the tool 1 is reciprocally moved along the surface of the mold 2 in the direction of arrow a so that the cutting direction and the moving direction are substantially orthogonal to each other.

On the other hand, when machining is performed as shown in FIG. 7A, as shown in FIG. 7C, a non-machined uncut portion, a so-called cusp 3, occurs between adjacent tool loci CL. This cusp 3 will be linearly formed in the processed die 2 along the tool locus CL direction, and an operator must remove the cusp 3 manually in the finishing process. Therefore, the efficiency of mold processing is low,
Further, there is a problem that the precision and quality of the mold vary depending on the skill level of the worker.

The present invention solves the above-mentioned inconvenience, and by machining the object to be machined by using the NC machining data orthogonal to each other, the NC is not applied with an excessive load, and the NC is An object of the present invention is to provide an NC processing method capable of reducing the burden in the finishing step of the processed product after processing.

[0009]

In order to achieve the above-mentioned object, the present invention uses NC data based on shape data of processed products.
In the method of creating processing data, moving a tool according to the NC processing data to process an object to be processed, and obtaining the processed product, the curvature of the processed surface with respect to at least one direction of the processed product is a predetermined value or less. And a second step of setting first tool trajectory data that is substantially parallel to the one direction based on the shape data of the machining range, and a trajectory direction of the first tool trajectory data. A third step of setting a trajectory direction orthogonal to the second tool trajectory data, a fourth step of converting the first and second tool trajectory data into NC machining data, and NC machining based on the first tool trajectory data. A fifth step of processing the processing target object based on data, and a step of processing the processing target object based on NC processing data based on the second tool trajectory data. Wherein the sixth step of engineering, in that it consists of.

[0010]

In the NC machining method of the present invention, the first tool for selecting a machining range having a small curvature in at least one direction from the shape data of the processed product and performing machining in the direction having the smaller curvature with respect to the machining range. The trajectory data is set, and the second tool trajectory data orthogonal to the first tool trajectory data is set. Then, first, the processing object is processed by the NC processing data obtained from the first tool trajectory data. In this case, since the machining based on the first tool trajectory data is performed in the direction in which the curvature of the object to be machined is small, the tool is not overloaded. Then, the cusp left uncut in the above step is removed by the NC processing data obtained from the second tool trajectory data. In this case, most of the object to be machined has already been cut, so even if cutting a part with a large curvature, the tool will not be overloaded and the cusp will be removed by this work. Therefore, the finishing process by the worker in the post process can be facilitated.

[0011]

The NC processing method according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a block diagram of an NC data creation system 10 to which the NC processing method according to the present invention is applied. This NC data creation system 10 has a central processing unit, a computer 11 having a role of graphic processing, display control, database management, etc., a magnetic disk database 12 capable of storing and updating a large amount of graphic information, NC data creation. The NC data output device 13 that outputs the NC processed data created in the system 10, the display device 14 and the display device 14 that are the main devices for the dialog between the system and its user, and are used in conjunction with the input device. It is composed of input devices such as a tablet 15, a keyboard 16, a mouse 17, and a volume switch 18 which are connected.

Then, the NC data creation system 1 described above
0 has many programs as shown in the program configuration diagram of FIG. Each program can be classified into the following modules according to the function to be shared.

(1) Operating system 32 and control module 34 for controlling processing and information flow in the NC data creation system 10, (2) Various input devices, for example, input operations corresponding to the keyboard 16 are performed smoothly. An input module 44, which assists
(3) Input interpretation module 40 that interprets the input information according to the command instruction format, (4) Display module 38 that manages display information and performs display processing according to the command, (5) From sub-module corresponding to the instruction A graphic processing command module 24 for performing graphic processing according to a command to be configured, (6) a database operation module 50 for efficiently searching and accumulating a large amount of information necessary for creating NC processed data held in the database 54, ( 7) Macro module 28 that executes the macro program 28a that is an automatic design program, (8)
Tool locus calculation module 26 for calculating a tool locus (NC machining data) for machining the press die, (9) Other CA
External system interface 30 for exchanging information with the D system and other NC data creation systems and for interlocking processing
And so on.

Further, this NC data creation system 10
In order to maintain expandability and maintainability,
There are auxiliary files such as a system control file 22 that stores the configuration and standard value of 0, a command control file 42 that stores the operability of each command and a program control procedure, and a display control file 36 that stores the model and configuration of the display device. It is prepared. Also, a graphic processing library 46 for processing graphics, a display library 48 for displaying on the display device 14, and an NC data conversion utility for outputting the NC processed data created by the system 10 to the NC data output device 6. 56, a data exchange utility 52 for coupling with other systems is provided.

Next, each module will be briefly described.

The control module 34 modularizes the program group and intervenes between the modules,
Centralize control of in-system control and standardize calling procedures. Its functions are start, end, abnormal processing, execution control of each module, execution history recording, debug function, and special processing with the operating system 32.

The input module 44 provides the user with a comfortable input procedure according to a specification in which various input methods of various input devices are unified. The function is to prompt the user for the type of information to be input, the input method and the input device, select the input information, and convert the input information into the standard type.

The input interpretation module 40 unifies the method of interpreting the input information and the result display to support various input instruction methods to improve the input operability and maintain the expandability of the system. Its function is to interpret the input information and display the interpretation result.

The display module 38 uniformly processes various display operation requests and manages display information and display state.

The graphic processing command module 24 centrally manages the format of the input argument, the calling of the processing program according to the command, and the processing method of the result, and maintains the maintainability and expandability of the system.

The database operation module 50 standardizes the request method from other modules and provides a recovery means when a failure occurs. The functions are management of database usage, operation of the database 54, processing at the time of failure, and the like.

The external system interface 30 standardizes the exchange of information with other systems to make effective use of the NC data creation system 10. The function exchanges information with an external system and controls the operation of an external program.

The macro module 28 controls the execution of the NC data creation system 10 according to the created macro program 28a. Its function is to translate and execute the macro program 28a.

The tool locus calculation module 26 includes a machining range set as described later, a material of a machining object, a machining type (rough machining, medium machining, finishing machining, etc.), and a type of tool used for machining ( Ball end mills, flat end mills, etc.), tool diameters, physical specifications such as blade length, etc., as well as the first tool for each machining range based on parameters such as M / C (machining center) and NC device specifications. The trajectory data and the second tool trajectory data, which is the trajectory direction orthogonal to the trajectory data, are calculated.

Next, a method of creating NC processed data using the NC data creating system 10 configured as described above will be described with reference to the flowchart shown in FIG.

First, the wireframe model data of the final product is input to the database 54 from the external CAD system using the data conversion utility 52, and the macromodule 28 sends the wireframe model data to the wireframe model data. , Plane, curved surface, etc. 3
Dimensional model data is created (step S10). Figure 4
Uses the three-dimensional model 51 in the case of a panel constituting a car body as the product as an example.
It is what was displayed in.

Next, a 3D model corresponding to the 3D model 51 is used.
Based on the dimensional model data, the shape design data of the press die is created in consideration of the production technology (production know-how) of the press die for creating the product (step S).
20).

Next, a range that can be continuously processed at once is set for the shape design data (step S3).
0). An example of this processing range 53 is the three-dimensional model 51 of FIG.
It corresponds and shows. That is, the processing range 53 is set for a portion of the three-dimensional model 51 corresponding to the press die with a small curvature of the curved surface in at least one direction. As shown in FIG. 7A, the above setting is performed when the tool 1 is used for machining in the direction of the arrow a.
Is to prevent the load from increasing as shown in FIG. 7B.

When the machining range 53 is set, two tool trajectory directions are determined for each machining range 53, and first and second tool trajectory data (NC machining data) are calculated for each tool trajectory direction. (Steps S40, S
50, S60). The tool path direction is the machining range 52
Shape of the mold 2 (Fig. 5) that is the object to be processed in, the material of the mold 2, the processing type (roughing, medium processing, finishing, etc.), the type of tools used for processing (ball end mill, flat end mill) Etc.), physical specifications such as tool diameter and blade length, and parameters such as specifications of M / C (machining center) and NC device (input means such as keyboard 16 to NC data creation system 10). ) Is taken into consideration, the operator determines so that the cutting resistance does not become excessive. For example, with respect to the mold 2 shown in FIG. 5, the first tool locus CL1 is set so that the curvature of the machined surface becomes minimum in the cutting direction of the mold 2 by the tool 1. Also,
The second tool locus CL2 is set to be orthogonal to the first tool locus CL1. The first and second tool trajectory data set in this way are stored in the database 54 by the database operation module 50.

The processing of steps S40 to S60 is performed for each machining range 53 (step S70), and when the setting of the tool locus data for all the machining ranges 53 is completed, the tool locus data is converted into the NC data conversion utility 56. Is converted into NC processing data for controlling the operation of the tool 1 (step S80), and then supplied to the NC device by the NC data output device 13 (step S90).

The die 2 is processed based on the NC processing data created as described above. In this case, in the NC device, first, machining is performed along the tool locus CL1 shown in FIG. Since this machining direction is set to a direction in which the curvature of the machining surface of the die 2 is small, the tool 1 can perform the machining of the die 2 without receiving excessive cutting resistance as compared with the die 2. Note that the cusp 3 shown in FIG. 7C remains in the mold 2 due to the processing along the tool locus CL1.

Next, the NC apparatus processes the die 2 along the tool locus CL2 shown in FIG. The tool 1 removes the linear cusp 3 remaining in the above process, and finally only the dot cusp 55 shown in FIGS. 6A to 6C remains. In this case, when the machining is performed along the tool locus CL2, the tool 1 moves in a direction in which the curvature of the die 2 increases, but most of the cut portion has already been removed from the die 2. However, a problem such as an increase in cutting resistance does not occur.

Finally, the operator removes only the slightly remaining cusp 55, and the working operation of the die 2 is completed. Note that the work by the operator in this case is performed by the dot-shaped cusp 55.
Since only (see FIG. 6A) is removed, the work time is short, and the work result hardly depends on the skill of each worker.

[0035]

As described above, according to the NC machining method according to the present invention, the machining target is machined in the direction in which the curvature of the machining surface of the machining product is equal to or less than the predetermined value based on the first tool trajectory data. After that, processing is performed in the direction orthogonal to the processing direction based on the second tool trajectory data. By performing the machining as described above, the tool is not subjected to excessive cutting resistance than the object to be machined, and the finishing work by the operator after the NC machining can be easily and accurately performed. Thereby, a highly accurate processed product can be efficiently obtained.

[Brief description of drawings]

FIG. 1 is an N for implementing an NC processing method according to the present invention.
It is a block diagram of the NC data creation system which creates C processing data.

FIG. 2 is a program configuration diagram of an NC data creation system.

FIG. 3 is an N for implementing the NC processing method according to the present invention.
It is a flow chart which creates C processing data.

FIG. 4 is an explanatory diagram of products displayed on a display device and processing ranges set therein.

FIG. 5 is an explanatory diagram of a tool locus showing an NC processing method according to the present invention.

FIG. 6A is a plan view of a tool locus showing an NC processing method according to the present invention, and FIGS. 6B and 6C are explanatory views of a cusp in a cross section of FIG. 6A.

7A is an explanatory view of a conventional NC processing method, FIG.
7B is a cross-sectional explanatory view of a cusp generated by the method shown in FIG. 7A, and FIG. 7C is a cross-sectional explanatory view in the case of processing a die in a direction having a large curvature.

[Explanation of symbols]

1 ... Tool 3 ... Cusp 10 ... NC data creation system 11 ... Computer 12 ... Magnetic disk database 13 ... NC data output device 14 ... Display device 15 ... Tablet 16 ... Keyboard 17 ... Mouse 51 ... Three-dimensional model 53 ... Machining range 55 ... Cusp CL1 ... 1st tool locus CL2 ... 2nd tool locus

Claims (1)

[Claims] 1. A method of obtaining NC processed data by creating NC processed data from shape data of a processed product, moving a tool according to the NC processed data to process a processed object, and obtaining the processed product. A first step of setting a machining range in which the curvature of the machined surface with respect to at least one direction is equal to or less than a predetermined value, and based on shape data of the machining range, first tool locus data that is substantially parallel to the one direction is set. A second step; a third step of setting a trajectory direction orthogonal to the trajectory direction of the first tool trajectory data as second tool trajectory data; and a step of converting the first and second tool trajectory data into NC machining data. 4 steps, 5th step which processes the said to-be-processed object by NC processing data based on the said 1st tool trajectory data, 2nd tool trajectory Sixth step and, NC processing method characterized by comprising the machining the workpiece by the NC machining data based on the over data.