JPH02132503A - Numerical control data producing device - Google Patents

Abstract

PURPOSE:To shorten the rough cutting operation time and to secure the even finishing margin by cutting a work in terms of a plane and in the largest cutting depth possible with the corresponding tool. CONSTITUTION:In the case of a tool having the largest diameter, a cutting area is calculated from the material form and the finishing form of a work. Then the plane cutting areas of each stage which are successively cut in terms of a plane in response to the diameter of a used tool and the cutting depth are calculated for the cutting remainder areas which are successively calculated with the tools used at each immediately preceding state in the case of the tolls having the diameters which are successively smaller than the largest one. Then a cutting remainder area of the corresponding tool is calculated from the calculated plane cutting area and the finishing form and then used as the cutting remainder area to the used tool having the next largest diameter. Then the numerical control NC data is produced according to the tool path and based on each of plane cutting areas calculated with use of the tools having the diameters smaller than the largest one as well as the diameters of these tolls. Thus it is possible to shorten the rough cutting operation time and to finally secure the even finishing margin.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to an apparatus for creating NC data for three-dimensional machining.

[Prior art]

Conventionally, when three-dimensional machining is performed, a workpiece is fixed to a workpiece table and the workpiece is machined while moving a tool such as a ball end mill and the workpiece relatively three-dimensionally. The limit value of the depth of cut that can be taken by the tool used is determined depending on the material of the workpiece to be machined, the rotation speed of the tool, the feed rate of the tool, etc., and as shown in Figure 6, the material shape of the workpiece Cutting was performed using one rough cutting NC data for the rough cutting shape until the completion of cutting the rough cutting shape.

[The secret problem that the invention tries to solve]

When rough cutting is performed as described above, in the initial stage, there are many idle cutting parts and there are many unnecessary movements. or,
If the same tool is used, the diameter of the tool must be selected according to the rough cutting shape, and the cutting amount is large, making it impossible to use a tool with good machining efficiency. Therefore, a very long time is spent on rough cutting, which is the stage before starting finishing cutting. The present invention has been made to solve the above problems, and its purpose is to use several types of tools, starting with the one with the highest machining efficiency, to achieve a final uniform finish. N that can generate NC data for rough cutting with allowance left.
The object of the present invention is to provide a C data creation device.

[Means to solve the problem]

The structure of the invention for solving the above problem is, as shown in the concept in FIG. A finishing shape memory means for storing the finished shape, a material shape memory means for storing the shape of the material of the workpiece, a tool condition storing means for storing the tool diameter and depth of cut with respect to the material of the workpiece for each tool; In the case of a maximum diameter tool, the cutting area determined from the material shape stored in the material shape memory means and the finished shape stored in the finished shape memory means, and the cutting area determined from the material shape stored in the material shape memory means and the finished shape stored in the finished shape memory means, and the cutting area determined by successively smaller diameters used following the maximum diameter tool. In the case of a tool, the remaining cutting area calculated sequentially for the tool used immediately before by the remaining cutting calculating means is sequentially calculated according to the diameter of the used tool and its depth of cut stored in the tool condition storage means. A cutting area calculating means for calculating a flat cutting area of each stage to be flat-cut, and cutting of the tool used based on the flat cutting area calculated by the cutting area calculating means and the finished shape stored in the finished shape storing means. Calculate the remaining area,
a remaining cutting area calculation means that determines that area as the remaining cutting area for the next tool with a smaller diameter, and each planar cutting area calculated by the cutting area calculation means when the tool used is sequentially decreased from the maximum diameter, and The present invention is characterized by comprising an NC data generation means for generating NC data according to the tool path from a tool diameter of a tool for machining a plane cutting area.

[Effect]

In the case of the largest diameter tool, the cutting area determined from the shape of the workpiece material and finished shape, and in the case of tools of successively decreasing diameter used following the largest diameter tool, the cutting area determined from the previous tool used. Regarding the sequentially calculated remaining cutting area, the planar cutting area of each stage to be planarly cut in sequence is calculated according to the diameter of the tool used and its depth of cut. Based on the calculated plane cutting area and finished shape, the remaining cutting area of the tool used is calculated, and this area is set as the remaining cutting area of the next tool with a smaller diameter. NC data is generated according to the tool path from each plane cutting area calculated when the used tool is sequentially reduced from the maximum diameter and the tool diameter of the tool that processes the plane cutting area.

【Example】

The present invention will be described below based on specific examples. In FIG. 2, 10 is a numerical control device, and this numerical control device 1o includes servo motor drive circuits DUX, DUY.
, DUZ, and sequence controller 11 are connected via an unillustrated interface. On the other hand, 20 is a machining center type machine tool controlled by the numerical control device 1o having the above configuration, and the servo motor drive circuit DUX. By the rotation of the servo motors 21, 22, and 23 driven by each of the DUYDUZ, the rotation between the workpiece table 25, which supports the workpiece W, and the spindle head 24, which supports the spindle 26 driven by the spindle motor SM, is caused. The relative position is changed three-dimensionally. Further, 27 is a tool magazine that holds a plurality of types of tools, and the tools in the tool magazine 27 are selectively mounted on the spindle 26 by a magazine indexing device (not shown) and a tool changing device 28, so that the tools can be attached to the workpiece W. Processing is performed. The sequence controller 11 also includes a computer 1.
2 and a main shaft motor drive circuit 15 that controls the rotation speed of the main shaft motor SM. This computer 12 has a microprocessor 12a1, a clock O-7, a signal generating circuit 1,
2b, ROMI 2c, RAM 12d, fixed disk 12e1 interface 12f, 12g. 12
A keyboard 13 and a CRT display device 14 are connected to the interface 12h. Next, the processing procedure of the MPU 12a will be explained based on the flowchart of FIG. 3, with reference to FIG. 4, which is a cross-sectional view illustrating the plane cutting area at each processing stage for each tool. In step 100, information representing the tool path, in step 102, information representing the three-dimensional shape of the machining curved surface, which is the finished shape of the workpiece W, and in step 104, information representing the three-dimensional shape, which is the material shape of the workpiece W, Tool T used in step 106
The tool diameter φDi for each + (i = 1.2.-.n) and the cutting depth C of the tool with respect to the material of the workpiece W to be machined are input from the keyboard 13 to the fixed disk 12e. Here, the tool diameter φDI is φDI>φ
Let it be D l + 1. Hereinafter, for convenience of explanation, the tools used are T, . The cutting depth C2 of the tool T2 is half the cutting depth CI of the tool T1. When the input of each data is completed, the process moves to step 108, and the cutting area is determined from the finished shape of the workpiece W stored in step 102 and the three-dimensional shape that is the material shape of the workpiece W stored in step 104. is determined by the cutting area calculation means. Among the tools used in the cutting area stored in step 106, the largest diameter tool T1
A plane cutting area for the Z1 plane in the Z direction, which is the cutting direction of the workpiece, is calculated to be equal to the depth of cut CI. Next, the process moves to step 110, and according to the tool path stored in step 100, NG data is generated by the NC data generation means from the Z calculated in step 108, the plane cutting area for the plane and its tool diameter φD, generate. Then, the process moves to step 112, and it is determined whether there are any remaining tools. Since there is a remaining tool T, step 112
The determination is YES, and the process moves to step 114, where the remaining cutting distance up to the Z plane in the Z direction, which is the cutting direction of the workpiece W, is calculated based on the plane cutting area calculated in step 108 and the workpiece stored in step 102. The remaining cutting area is calculated from the finished shape by the remaining cutting calculating means. Next, the process moves to step 116, and the maximum diameter tool among the remaining tools is cut until the Z plane, which is the height in the Z direction where the maximum diameter tool is cutting, which is the remaining cutting area calculated in step 114, is reached. Since the remaining tool is only T, the planar cutting area at the depth of cut C is calculated by the cutting area calculation means. Next, the process moves to step 118, and it is determined whether the plane cutting area up to Z, which is the height in the Z direction at which the maximum diameter tool cuts, and the plane has been calculated. If the plane cutting area up to the Z1 plane, which is the height in the Z direction at which the maximum diameter tool cuts, has not been calculated, the process returns to step 116, and further, the cutting depth C2 is set to the cutting depth C2.
Calculate the plane cutting area of the cutting surface by adding . In this way, the plane cutting area is calculated one after another for each cutting depth C, and in step 118, the plane cutting area up to Z, which is the height in the Z direction cutting by the maximum diameter tool, is calculated. In this case, since the depth of cut C of the tool T is half of the depth of cut C of the tool T1, one plane cutting area is calculated by the depth of cut C2 of the tool T2, and step 118 Without returning to step 116, the process moves to step 110, and according to the tool path stored in step 100, NC data is generated from the tool diameter φD for each plane cutting area calculated in step 116. Then, since there are no remaining tools, the determination in step 112 becomes NO and the process moves to step 120. In step 120, Z, which is the final depth of cut as the height in the Z direction, determined by the finished shape stored in step 102;
, to the plane, it is determined whether the generation of NC data using the maximum diameter tool has been completed. If it is not finished, the judgment is N.
O, the process moves to step 122, and the next Z-direction height Z plane is calculated at the cutting depth C1 of the maximum diameter tool T1, that is, the Z-direction height is calculated by adding the cutting depth CI to the cutting depth CI. 22 plane height value. Next, the process moves to step 108, and the planar cutting area in the 22 planes at the height in the Z direction calculated in step 122 is calculated. Steps 110 to 118 are then explained in the same manner as above, and in step 110 the tool T. ．． Generate NC data by T2. Then, in step 112, if there are no remaining tools, the determination becomes NO, and the process moves to step 120, where the final depth of cut Z, . It is determined whether the generation of NC data using the maximum diameter tool has been completed up to the plane. In this way, N
C data is generated and the Z.C data is generated, which is the final depth of cut. , up to the plane, when the generation of NG data for the maximum diameter tool is completed, the determination becomes YES and the program ends. The above program is explained with reference to FIG. 4, which is a longitudinal cross-sectional view of the raw material shape and rough cutting shape of the workpiece W, but the raw material shape and rough cutting shape of the workpiece W at one height in the Z direction are explained. Further explanation will be added regarding FIG. 5, which shows a cross-sectional view of the cutting shape. After cutting with the maximum diameter tool T1, the cutting tool T. The uncut area that cannot be cut remains as shown in the figure, but the cutting tool T with tool diameter φD2
By continuing to cut with a No. 2 grade, the uncut area can be reduced, and it is possible to obtain a finished shape that approximates the rough cut shape of the workpiece. In exchanging each cutting tool, an ATC command is inserted during program execution so that the tools in the tool magazine 27 are selectively and automatically exchanged by the tool exchanger 28 or the like. In the above program, for the remaining cutting area up to the plane cutting area in the Z direction, which is the cutting depth of the maximum diameter tool, the plane cutting area is repeatedly calculated according to the cutting depth using the remaining tool. However, for the remaining cutting area after generating NC data up to the final Z7 plane cutting area in the Z direction, which is the finished shape, at the depth of cut with the maximum diameter tool, The planar cutting area may be calculated based on the depth of cut of the remaining tool. In addition, in order to reduce the finishing stock in finishing cutting, the number of cutting tools should be selected appropriately after considering the rough cutting time, and the final cutting tool should have a small diameter and a small depth of cut. This can be achieved by choosing things. In this way, rough cutting time can be reduced by using several types of tools, starting with the tool with the highest machining efficiency, and cutting flatly at the maximum depth of cut that the tool can cut into the workpiece. Since the rough cutting process is shortened and ultimately leaves a uniform finishing allowance, it is possible to provide an NG data creation device that can generate NC data for rough cutting with good processing efficiency even in the subsequent finishing cutting process.

【Effect of the invention】

In the case of a maximum diameter tool, the present invention provides a cutting area determined from a material shape stored in a material shape memory means and a finished shape stored in a finish shape memory means, and a sequential diameter used following the maximum diameter tool. In the case of a tool that becomes smaller, the remaining cutting area calculated sequentially for the tool used immediately before by the remaining cutting calculation means is calculated according to the diameter of the used tool and its depth of cut stored in the tool condition storage means. A cutting area calculation means calculates the plane cutting area of each step of plane cutting in sequence, and the remaining cutting area of the tool used is calculated from the plane cutting area calculated by the cutting area calculation means and the finished shape stored in the finishing shape storage means. Since the tool is equipped with a residual cutting calculation means that calculates the area and sets the area as the remaining cutting area for the next tool with a small diameter, there is no unnecessary movement such as empty cutting even in the initial stage of cutting. Also, first cut the cutting area with a cutting tool that has a large diameter and a large depth of cut, that is, a large cutting amount, and at the end of this rough cutting, try to avoid as much uncut material as possible. , the finished shape is approximated to the rough cut shape, and then the remaining uncut area is cut with another tool, which is a cutting tool with a small tool diameter and a small depth of cut, to finish the rough cut shape. Efficient rough cutting NC data can be created.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing the concept of the present invention. FIG. 2 is a configuration diagram showing the configuration of a numerical control device and a machine tool having an NC data creation device according to a specific embodiment of the present invention. FIG. 3 is a flowchart showing the processing procedure of the CPU used in the device of the embodiment. FIG. 4 is a longitudinal sectional view illustrating the plane cutting area at each processing stage for each tool in the flowchart of FIG. 3. FIG. 5 is a cross-sectional view illustrating the relationship between the tool diameter of the cutting tool and the remaining cutting area in one plane cutting area. FIG. 6 is a longitudinal sectional view illustrating a conventional cutting process. 10 ・゛Numerical control device 12 Computer 12a・
...Microprocessor 12e゜・゛゜Fixed disk 20...Machine tool 2
1.22.23...Servo motor 25...Workpiece table SM-Spindle motor W--One workpiece Patent applicant Toyota Machinery Co., Ltd. representative Patent attorney Osamu Fujitani Fig. 4-Workpiece 1 Figure 6: Cutting shape of workpiece

Claims (1)

[Scope of Claims] An apparatus for creating NC data for a machine tool that performs three-dimensional machining of a workpiece according to a tool path using a rotary tool, comprising a finished shape memory means for storing a finished shape of the workpiece, and a material of the workpiece. A material shape memory means for memorizing the shape; a tool condition memory means for memorizing the tool diameter and depth of cut relative to the material of the workpiece for each tool; The cutting area determined from the material shape and the finished shape stored in the finished shape memory means, in the case of a tool with a successively smaller diameter used following the largest diameter tool, the cutting area calculated by the cutting remaining calculation means Cutting area calculation means for calculating the planar cutting area of each stage to be planarly cut in sequence according to the diameter of the tool used and its cutting depth stored in the tool condition storage means, with respect to the remaining cutting area sequentially calculated for the tool. and calculating the remaining cutting area of the used tool from the plane cutting area calculated by the cutting area calculation means and the finished shape stored in the finished shape storage means, and applying that area to the next used tool with a smaller diameter. a remaining cutting area calculation means, each flat cutting area calculated by the cutting area calculating means when the tool used is sequentially reduced from the maximum diameter, and the tool diameter of the tool for machining the flat cutting area; and NC data generation means for generating NC data according to the tool path.