JP2001134311A - Method and device for preparing working data and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To apply smooth and uniform work to the whole working face by determining a tool route continued at approximately uniform density on the whole working face of a target to be worked which is composed of a composite curved surface. SOLUTION: Plural radiant lines 3 are extended from a start point S determined on a working surface along the working surface. Then respective points formed on respective radiant lines 3 and separated from the start point S by an equal distance are mutually connected to set up plural connection lines 4. Finally respective radiant lines 3 are divided into plural parts by intersections between adjacent connection lines 4, these divided points are ascendingly connected in the extending direction of the radiant lines 3 to form a spiral 5 around the start point S and the spiral 5 is determined as the route of a working tool.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of creating machining data representing a path of a tool used for machining a workpiece in order to obtain a target shape of the workpiece given as shape data. The present invention relates to an apparatus and a recording medium used for implementation.

[0002]

2. Description of the Related Art In the technical field of manufacturing a molding die for an industrial product, complicated processing surfaces including three-dimensional curved surfaces are required.
Processing with high precision and in a short time is required. To meet this demand, CAM (Computer Aided M
anufacturing) apparatus is used. The CAM device is
An apparatus (including a general-purpose computer equipped with a recording medium on which the creation procedure is recorded) for creating machining data including a tool path of a tool used for machining based on shape data giving a target shape of a workpiece. . The shape data is
Although it may be created based on drawings and entered manually, in general, CAD (Computer Aided Des
ign) created by the device and given online or offline to the CAM device.

[0003] Creation of machining data performed in a CAM apparatus using such shape data has conventionally been generally performed by the following three methods. In the first method, as shown in FIG. 9, a plurality of contour surfaces arranged at predetermined intervals in the height direction of the workpiece A are set, and the respective contour surfaces and the machining surface of the workpiece A are determined. (Hereinafter, referred to as a contour surface method) using the intersection line (contour line) of the above as a tool path.

In a second method, as shown in FIG. 10, a plurality of cut surfaces including a height direction of a workpiece A are set in parallel with each other at predetermined intervals, and each cut surface and a cut surface are set. This is a method (hereinafter, referred to as a cross-sectional method) in which an intersection line with a processing surface of the workpiece A is used as a tool path.

[0005] A third method is a method called a along-plane method. In this method, shape data of a workpiece given from a CAD apparatus in a format such as IGES is obtained by using Bezier,
Utilizing the combination of analytic surfaces (patches) represented by equations such as NURBS, one of the parameters (u, v) is fixed for each surface, and the curve obtained by moving the other is a tool. This is a method of setting as a route (a ...).

[0006]

However, in the first method, the contour surface method, as shown in FIG. 9, the workpiece A is substantially perpendicular to the height direction (Z direction). If it contains machined surface a ₁ that with neither cross plane, the tool path is not set in the pressurized Kumen a _1, was sometimes necessary processing is not performed.

[0007] In the second method, the cross-sectional method,
As shown in FIG. 10, when the workpiece A is substantially perpendicular to the (X direction in the drawing) the arrangement direction of the cut surface includes a working surface A ₂ that with neither cross the cut surface, the pressurized Kumen A _In some cases, the tool path was not set in ₂ and required machining was not performed.

[0008] Such inconvenience can be alleviated by such advance set narrow the distance between the level surface or cut surface, suitable number of crossover lines on the processed surface A ₁ or A in ₂ occurs However, in such a case, there is a problem that the total length of the determined tool path becomes longer, and the time required for machining increases.

Japanese Patent Application Laid-Open No. 8-123526 discloses that the interval between tool paths set at intersections between each contour surface and a machining surface in the above-mentioned contour surface method is examined, and that adjacent tool paths are determined by a predetermined distance. A method is disclosed for forcibly inserting one or more tool paths between them when a reference value is exceeded. However, in this method, when the reference value given as a parameter is set to an excessively large value, a machining surface into which a tool path is not inserted occurs and an incompletely machined portion remains, and conversely, the reference value is set to an excessively small value. In such a case, there is a problem in that a large number of originally unnecessary tool paths are set and the machining time is lengthened.

Conventionally, the contour surface method and the sectional method are combined, for example, a tool path is determined for the entire workpiece A by the contour surface method, and the tool path is substantially orthogonal to the height direction. how to determine the tool path by cross method only for processing surface a ₁ which is employed. However, in this method, selection of the working surface defining a tool path by cross method, have been made by the operator's discretion, rather than machined surface A ₁ of the large area as shown in FIG. 9, the same processing surface of a small area (Processed surface substantially perpendicular to the height direction) may be overlooked, and after performing processing according to the set tool path, an incompletely processed portion remains, and correction processing of the processed portion is forced. There's a problem.

Further, since the tool path by the contour surface method and the tool path by the cross section method are formed separately and are not continuous, a flaw generated at a position where the tool first comes in contact with each of the boundaries between the two. (Cutter mark) is formed and the workpiece A
In order to obtain a good finished state over the entire surface of the substrate, there is also a problem that a finishing process for removing a plurality of cutter marks formed at each boundary portion is required.

In the third method, the along-plane method, the tool path is set correctly along each of the patches given as the shape data from the CAD apparatus. Although a finished state can be obtained, the following problem occurs when applied to a workpiece having a complex curved surface represented as an aggregate of many patches.

FIG. 11 is an explanatory view of a problem of the along-plane method, in which a mesh is drawn along a parameter on a curved surface showing a part of a workpiece defined in a CAD apparatus.
Workpiece A illustrated is represented as a collection of a plurality of patch A ₃ to A _6, of these, in the patch A _3,
While mesh along the flow surface is formed in the patch A _4, mesh facing in a direction different from the flow surfaces are formed. This is because different depending on the definition of how each of the patches at the design stage by CAD system, when carrying out the surface along Method in patch A _4, along a path that is set along the mesh tool Moves unnaturally.

Further, since meshes are not continuous at the boundaries between the patches A _{3 to} A ₆ , the tool path must be set for each patch, and the contour surface method and the sectional method are combined. as with a result of the cutter mark is formed in the boundary portion of the patch a ₃ to a ₆ set tool path for each, in order to obtain a good finished state over the entire surface of the workpiece a, a number of There is a problem that complicated post-processing for removing the cutter mark is required.

Furthermore, as the patch A ₅ in FIG. 11, in the curved surface spacing mesh is represented in a state of clogged locally, since the density of the tool path obtained by surface along method is not constant, the patch There is also a problem that a difference occurs in the degree of finish in the inside.

The present invention has been made in view of such circumstances, and determines a continuous tool path at a substantially uniform density over the entire processing surface of a workpiece represented by a compound curved surface. The object of the present invention is to provide a method of creating processing data capable of forming a smooth and uniform processing surface over the entire surface by performing the processing according to, and an apparatus and a recording medium used for performing the method. And

[0017]

According to the present invention, there is provided a method for creating machining data, comprising: providing a path of a tool used for machining the machining surface to a workpiece to which shape data of the machining surface constituted by a compound curved surface is given; In the method of creating the processing data including, a plurality of radiations spread at an equal angle within one plane from a starting point appropriately determined on the processing surface, is set along the processing surface in each direction. Step, a plurality of connecting lines connecting points equal in distance from the starting point on each radiation along the processing surface, a step of elementally dividing the processing surface by these connecting lines and the radiation, Each of the radiations is divided into a predetermined number between the intersections of two adjacent connecting lines, and the dividing points on each radiation are connected in ascending order in the extending direction to form a screw around the starting point. Forming a line and connecting the screw with the path of the tool. Characterized in that it comprises a step of setting Te.

[0018] Further, the processing data creating apparatus according to the present invention comprises:
An apparatus for creating machining data including a path of a tool used for machining the machining surface for a workpiece given shape data of the machining surface configured by the composite curved surface, the machining data being appropriately determined on the machining surface. Radiation setting means for setting a plurality of radiations extending at an equal angle in one plane from the starting point along the processing surface in respective directions, and a plurality of radiations set by the radiation setting means. A plurality of connecting lines connecting points having the same distance from the starting point are set along the processing surface, and the element dividing means for dividing the processing surface by these connecting lines and the radiation, and the radiation setting means. Each of the set plurality of radiations is divided into a predetermined number between intersections of two connecting lines which are set by the element dividing means and are adjacent to each other. Ascending in the direction Linked to form a spiral around the starting point, characterized by comprising a tool path setting means for setting a 該螺 line as a path of the tool.

Further, in the recording medium according to the present invention, a procedure for creating machining data including a path of a machining tool for the machining surface on a workpiece to which shape data of the machining surface formed by the composite curved surface is given. In a computer-readable recording medium on which a computer program for causing a computer to execute is stored, the computer is caused to emit a plurality of radiations spread at equal angles in one plane from a starting point appropriately determined on the processing surface. Program code means for setting along the processing surface in the direction of, and causing the computer to set a plurality of connection lines connecting points having the same distance from the starting point on the plurality of radiations along the processing surface. Program code means for dividing the processing surface into elements by using these connecting lines and the radiation; Each of the lines is divided into a predetermined number between intersections of two connecting lines adjacent to each other, and the dividing points on each ray are connected in ascending order in the extending direction so as to be centered on the starting point. A computer program that includes a program code for forming a spiral and setting the spiral as a path of the tool.

In the present invention, first, a plurality of radiations which spread at an equal angle from an appropriately determined starting point are extended along the processing surface in the respective directions on the processing surface to which the shape data is given. . These radiations can be obtained as side ground lines in the respective directions between the divided elements constituting the processing surface. Next, a connection line connecting points having the same distance from the starting point is set on each radiation to divide the entire processing surface into elements. Finally, each of the radiations is connected to two adjacent connection lines. A predetermined number of division points are obtained between the intersection points to obtain division points, and these division points are connected in ascending order to form a spiral line centered on the starting point. The spiral line formed in this way is a line that starts at the starting point and is continuous at a substantially uniform density over the entire processing surface. By performing processing using the spiral line as a tool path, the entire spiral surface is formed. And a smooth and uniform machined surface can be obtained.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings showing the embodiments. FIG. 1 is a block diagram showing a configuration of a machining data creation device used for carrying out a machining data creation method according to the present invention (hereinafter, referred to as the present invention method).
The processing data creation device 1 includes a radiation setting unit 10, an element division unit 11, and a tool path setting unit, each of which is configured as an arithmetic processing unit.
And a data file 13 for storing the shape data of the machined surface of the workpiece used in the calculation as a result of the calculation performed as described below.

On the input side of the processing data creation device 1, CA
The D device 2 is connected, and the shape data of the workpiece used for creating the processing data performed according to the procedure described below is:
It is provided from the CAD device 2. An input operation unit 14 such as a keyboard and a mouse is provided on the input side of the processing data creation device 1 so as to be operable by an operator.

On the output side of the processing data creating device 1,
A display unit 15 such as a CRT display or a liquid crystal display is provided, and the display unit 15 is configured to display processing data created by the processing data creation apparatus 1 in a procedure described later. Further, the display unit 15 is configured to provide a display for assisting an input by operating the input operation unit 14 so that an operator can intervene in various stages of data creation.

In FIG. 1, the radiation setting unit 10, the element dividing unit 11, and the tool path setting unit 12 are shown as arithmetic processing units that are individually configured. The form is a CPU (Central Prism) that performs each operation according to a program stored in a ROM (Read Only Memory).
ocessing Unit) and the data file 13
Is a rewritable RAM (Random Access Me
mory), and the processing data creation device 1
The computer is configured to include the input operation unit 14 and the display unit 15 in addition to the U, the ROM, and the RAM.

Although the processing data creating apparatus 1 shown in FIG. 1 is configured such that the shape data of the workpiece is given from the CAD apparatus 2, the processing is performed by using the input data given by the operation of the input operation unit 14. Data creation device 1
It is also possible to adopt a configuration in which the shape data is created within, that is, a configuration that also serves as a CAD device. In this configuration, it is preferable that the display unit 15 perform display for assisting the operation of the input operation unit 14, such as the type of data to be input and the input order.

In the processing data creating apparatus 1 configured as described above, the object to which the shape data is given from the CAD apparatus 2 is targeted, and the processing data is formed on the processing surface formed by the composite curved surface of the processing object. The calculation for creating the machining data including the path of the tool used for machining the machining surface is performed in the following procedure.

FIG. 2 is an external perspective view showing an example of the workpiece. The workpiece A shown in the figure, like the workpiece A shown in FIGS. 9 and 10, has a flat rectangular processing surface A ₁ substantially perpendicular to the height direction (Z direction), and the processing surface A _1. and a working surface a ₂ to substantially decrease cut vertically in succession four sides of a _1, but forms a simple form, such as an inverted rectangular box body, the following procedure is constituted by a composite curved surface The same applies to a target having a complicated shape having a processed surface.

The shape data of the workpiece A as described above is represented by C
It is provided from the AD device 2 and stored in the data file 13 of the processing data creating device 1. The processing data creation device 1
Using the shape data of the workpiece A, the workpiece A
The operation of creating machining data including the path of the machining tool necessary for machining all the machining surfaces (including A ₁ and A ₂ ) collectively is performed. The tool rotates in an axis (X direction) while rotating about an axis parallel to the height direction (Z direction).
An end mill that moves in the Y plane) and performs cutting with a cutting edge provided at the tip, and the processing data is a combination of a movement path in the XY plane and a feed amount (cut amount) in the Z direction. Given as

FIG. 3 is a flowchart showing the procedure for implementing the method of the present invention. In carrying out the method of the present invention, first, processing conditions necessary for creating processing data, such as a diameter of a tool (end mill) to be used and a cuttable amount, are set (step 1), and a target workpiece is set. The shape data is imported (step 2). The setting of the processing conditions and the import of the shape data are performed according to the operation of the input operation unit 14 by the operator. At this time, it is preferable to display on the display unit 15 a display for input assistance such as contents to be input, a procedure, and the like. The shape data of the workpiece taken in step 2 is stored in the data file 13 as described above, and is used as needed.

After setting the processing conditions and taking in the shape data as described above, the starting point S of the tool path is set (step 3). This setting is made by operating the input operation unit 14 by the operator. At this time, the shape of the workpiece given as the shape data can be displayed on the display unit 15, and the starting point S can be designated on this display screen. The starting point S can be set at an appropriate position on the processing surface of the workpiece, but since it is the point where the tool first hits the processing surface of the workpiece, the starting direction S (Z
It is desirable that the point be located at the top of
In the workpiece A shown in ( ₁₎ , the center point of the flat processing surface A1 located at the uppermost position in the Z direction is preferably set as the starting point S.

By setting the starting point S in step 3, the preparation for processing data preparation is completed, and then the processing data generating apparatus 1 sets a plurality of radiations spread at equal angles within one plane from the starting point S. Is set along the processing surface (step 4). These radiations can be mathematically determined as geodesic lines where the distance along the working surface in each direction is the shortest.

FIG. 4 is an explanatory view of the procedure for forming the side ground wire.
You. As shown in FIG. 4 (a), the side ground lines constitute a processing surface.
Element B₁One point b on one side of₁From the surface in a predetermined direction
Element B with adjacent vector_TwoReached the border with
Later, the intersection b with the boundary side_TwoChange the direction with and element B_Twoof
Extended on the surface, and further comprising the element B_TwoElement B following
_ThreeIntersection b with_ThreeChange the direction in the element B_ThreeOn the surface of
It is similarly extended and formed. Element B_TwoOn the surface of
The extension direction of the geodesic line is, as shown in FIG.
B₁, B_TwoIs spread in one plane at the boundary between the two
Element B ₁Within b₁, B_TwoBek connecting
Tor, element B_TwoIn the direction as it is extended
And element B_ThreeThe geodesic direction above is forward
Notation element B_TwoCan be obtained by the same processing between
Wear.

In step 4, the above-described procedure is repeated at the boundaries between a number of elements constituting the machining surface, and the radiation is set by sequentially extending geodesic lines from the starting point S in the respective directions. Such setting of the radiation can be performed over the entire surface regardless of the shape of the processing surface. The radiation setting unit 10 performs the above-described arithmetic processing for radiation setting. FIG. 5 (a)
FIG. 7 is a plan view showing a setting mode of radiation going from a starting point S in eight directions. As shown in the figure, the radiations 3, 3,... Are extended in different directions according to the state of the processing surface on each path, and as a result, short straight lines for each element are continuous, and are curved in plan view. Is set.

The processing data creating apparatus 1 in which the radiation is set as described above sets a plurality of connecting lines connecting points having the same distance from the starting point S at each fixed interval on each radiation. The processing surface is divided by a number of rectangular elements defined by these and each radiation (step 6). These connecting lines can be set in the same manner as in the case of radiation as side ground lines extending from points on each radiation in a direction orthogonal to the radiation. Further, the juxtaposition intervals of the connection lines may be automatically determined according to the processing conditions set in Step 1, or may be numerically input as a part of the processing conditions.

In the element dividing section 11, the arithmetic processing for setting the connecting line as described above is performed. FIG. 5 (b)
The radiation lines 3, 3... Shown in FIG.
Is a plan view showing a state in which... Are set, and the processed surface of the workpiece is formed into a group of elements that spread in a spider web centering on the starting point S by radiations 3, 3. Elements are divided.

After such element division, each of the connecting lines 4, 4
The length between the intersections of the adjacent radiations 3, 3 generally increases as the distance from the starting point S increases, but the radiations 3, 3,. Since it is configured as a curve that changes direction, the length between the intersections may be reduced on the contrary. Therefore, when the length between the intersections is too large, a new radiation is added between these intersections, and conversely, when the length between the intersections is too small,
By thinning out one of the radiations, the accuracy of the tool path determined as follows can be improved.

[0037] FIG. 6 is an explanatory view of an state of adding and thinning of radiation, added in multiple locations of C ₁ parts like in the figure, the thinning is performed respectively in the same C ₂ parts. In addition, the addition of radiation starts from the midpoint between the intersections with the target connecting line, and sets the new radiation in the direction that averages the respective directions of the radiation on both sides. Of the new radiation,
This is achieved by obliterating the extension of radiation on both sides. Such addition and thinning processing may be performed unconditionally in accordance with the length between the intersections.
It may be performed on the condition that the operator who operates 14 intervenes.

After the element division as described above is completed including the addition and thinning out of the radiation, the processing data creating apparatus 1 places each of the plurality of radiations at a predetermined point between the intersections with two adjacent communication lines. The radiation is divided into numbers, and the division points on each ray are connected in ascending order in the direction in which they are extended to set a spiral centered on the starting point S (step 7).

FIG. 7 is an explanatory diagram of a procedure for forming a spiral.
As shown, each radiation 3,3... Has two connecting lines 4,4.
Are equally divided by a plurality of (three in the figure) division points D ₁ , D ₂ , D ₃ set between the intersections with
Are the division points D ₁ ,
The procedure of connecting D ₂ , D ₃ in the ascending direction of the radiations 3, 3..., Ie, dividing the appropriate division point D ₁ on the radiation 3 on the radiation 3 adjacent to one side thereof connected to the point D _2,
Is set by repeating the further steps of connecting the dividing points D ₂ to the dividing point D ₃ on radiation 3 Neighboring on the same side. The tool path setting unit 12 performs the above-described arithmetic processing for setting the spiral line 5 and outputs the spiral line 5 set as described above as machining data indicating the tool path.

FIG. 5C is a plan view showing a state in which the spiral line 5 is set on the processing surface obtained by dividing the element as shown in FIG. 5B, and the spiral line 5 set as described above is As shown, the line starts from the starting point S and extends in one direction while increasing the distance from the starting point S. Here, each of the radiations 3, 3...
Are equally divided by..., And are equally divided by the division points D ₁ , D ₂ , D ₃ between intersections of two adjacent connecting lines 4, 4. _1, D _2,
Spiral 5 formed by connecting the D ₃ becomes possible to continuously maintain a substantially uniform density over the entire working surface.

The number of division points between the adjacent connecting lines 4 and 4 is not limited to three as shown in FIG. 7, but can be set to an appropriate number. This number determines the density (interval between overlapping portions) of the spiral lines 5 set as described above, and may be set to an appropriate number according to the processing conditions set in step 1. A numerical value may be input as a part of the condition. Further, it is desirable that the number of the division points be increased or decreased according to the above-mentioned addition or thinning of the radiation. This increase / decrease processing may be performed unconditionally in accordance with the addition or thinning out of the radiation, or may be performed on the condition that the operator operating the input operation unit 14 intervenes.

As described above, in the method of the present invention, starting from the starting point S appropriately set on the processing surface, a spiral line maintaining a substantially uniform density is formed along the processing surface over the entire surface. Since the line is set as the path of the tool used for processing the processing surface, the processing surface of the workpiece formed by the compound curved surface is uniformly processed by the tool following a single path over the entire surface. Becomes possible.

In the above-described embodiment, a case has been described in which a dedicated apparatus (the processing data creating apparatus 1) is used to execute the method of the present invention. However, the above-described procedures are recorded as a computer-readable program. This recording medium is mounted on a general-purpose computer to load the program, and the present invention is implemented by using a CPU as an arithmetic processing unit, a RAM as storage means, and the like provided in the computer. The method can also be practiced.

FIG. 8 is a schematic diagram showing such an embodiment. In the figure, RM denotes a recording medium such as a magnetic disk or an optical disk. The recording medium RM is provided along the processing surface of the workpiece to which the shape data is given from the starting point on the processing surface in each direction. A program code PC11 for causing a computer to perform a process of setting a plurality of rays to be spread, a plurality of connecting lines connecting points having equal distances from the starting point of each set ray are set along the machining surface, and the machining surface is defined as an element. Dividing each radiation into a predetermined number between the intersections of two adjacent communication lines with the program code PC12 that causes the computer to perform the dividing process, and dividing points on each radiation in ascending order in the extending direction And a program code PC13 for causing the computer to perform a process of forming a spiral line centered on the starting point by connecting to the computer program.

When such a recording medium RM is mounted on the disk drive 7 of the general-purpose computer 6 and read processing is performed, the computer program recorded on the medium RM is loaded on the computer 6 and the computer 6
Executes the above-described arithmetic processing to obtain machining data including a path of a tool used for machining.

[0046]

As described in detail above, in the processing data creating method and the processing data creating apparatus according to the present invention, and the recording medium according to the present invention, the processing surface of the workpiece constituted by the composite curved surface is appropriately provided. A spiral line extending from the starting point along the surface of the processing surface is formed, and this screw line is set as a tool path of the processing tool, so that the distribution is made at a substantially uniform density over the entire processing surface having a complicated shape. It is possible to set a tool path to be performed, and by the processing tool moved along this tool path, it is possible to perform smooth and uniform processing over the entire surface regardless of the form of the processing surface, In addition, the load applied to the tool during this period does not fluctuate much, and it is easy to cope with high-speed machining. Furthermore, since the spiral line set as the tool path is continuous over the entire processing surface, only a cutter mark associated with the first contact with the tool is formed at the starting point, and complicated post-processing is required. The present invention has excellent effects, such as obtaining a good finished surface without any problem.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a processing data creation device according to the present invention.

FIG. 2 is an external perspective view illustrating an example of a workpiece.

FIG. 3 is a flowchart showing a procedure for implementing the method of the present invention.

FIG. 4 is an explanatory diagram of a procedure for forming a side ground line.

FIG. 5 is an explanatory diagram of an execution procedure of the method of the present invention.

FIG. 6 is an explanatory diagram of an implementation state of addition and thinning of radiation.

FIG. 7 is an explanatory view of a procedure for forming a spiral line.

FIG. 8 is a schematic view showing another embodiment of the present invention.

FIG. 9 is a diagram showing a tool path set by the contour surface method.

FIG. 10 is a diagram showing a tool path set by a cross-sectional method.

FIG. 11 is an explanatory diagram of a problem in the along-plane method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Processing data creation apparatus 2 CAD apparatus 3 Radiation 4 Connection line 5 Screw wire 10 Radiation setting part 11 Element division part 12 Tool path setting part

Claims (3)

[Claims] 1. A method for creating machining data including a path of a tool used for machining a machining surface on a workpiece to which shape data of the machining surface formed by a compound curved surface is given, A step of setting a plurality of radiations spreading at an equal angle in one plane from a starting point appropriately determined along the processing surface in each direction, and a distance from the starting point on each radiation is equal. A step of setting a plurality of connecting lines connecting points along the processing surface, dividing the processing surface into elements by using these connecting lines and the radiation, and two connecting lines adjacent to each of the radiations Is divided into a predetermined number between the intersections, the dividing points on each ray are connected in ascending order in the extending direction to form a spiral centered on the starting point, and the spiral is used as a path of the tool. And a setting process. Data creation method. 2. An apparatus for creating machining data including a path of a tool used for machining a machining surface of a workpiece given shape data of the machining surface formed by a compound curved surface, wherein Radiation setting means for setting a plurality of radiations spread at an equal angle in one plane from a starting point appropriately determined along the processing surface in each direction, and a plurality of radiations set by the radiation setting means. Element dividing means for setting a plurality of connection lines connecting points having the same distance from the starting point on the radiation along the processing surface, and dividing the processing surface by these connection lines and the radiation, Each of the plurality of radiations set by the radiation setting means is divided into a predetermined number between intersections of two connecting lines which are set by the element dividing means and are adjacent to each other. The above A machining path creation means for forming a spiral line centered on the starting point by connecting in the ascending order in the extending direction, and setting the spiral line as a path of the tool. . 3. A computer program for causing a computer to execute a procedure for creating machining data including a path of a machining tool for a machining surface of a workpiece to which a shape data of the machining surface constituted by a compound curved surface is given. A computer-readable recording medium on which a plurality of radiations spread at equal angles within one plane from a starting point appropriately determined on the processing surface are directed to the processing in each direction. Program code means for setting along the surface; and causing the computer to set a plurality of connecting lines connecting points having the same distance from the starting point on the plurality of radiations along the processing surface. A program code means for dividing the processing surface into elements by means of radiation, and a computer A predetermined number of intersections between the intersections of the two connecting lines, and connecting the dividing points on each ray in the ascending direction in the extending direction to form a spiral line centered on the starting point, A computer readable recording medium characterized by recording a computer program including program code means for setting a spiral as a path of the tool.