Data creation program, data creation device, and data creation method
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- NHK SPRING CO LTD
- Filing Date
- 2023-03-29
- Publication Date
- 2026-06-30
Smart Images
Figure 0007882801000001 
Figure 0007882801000002 
Figure 0007882801000003
Abstract
Description
[Technical Field]
[0001] This invention relates to a data creation program, a data creation device, and a data creation method. [Background technology]
[0002] Reverse modeling is widely used to compare the actual shape of products and structures with their design shapes, or to perform Finite Element Method (FEM) simulations using the actual shape. In reverse modeling, mesh data acquired by a 3D measuring machine is converted into geometric data that can be used with general-purpose CAD software using specialized data processing software. Geometric data is the mesh data D M Multiple curved surface patches D are shown above. P It is created by joining these together (see Figure 11(a)). Line D between curved patches F These remain in the geometry data and are called feature lines (see Figure 11(b)). At this time, line D F Depending on the purpose, it may be necessary to form feature lines that conform to the shape of the product or structure.
[0003] In coil springs, factors such as free height, inclination, and coil diameter affect the generated stress, and depending on the quality of the product, the generated stress may differ from the design stress. To understand this difference, it is necessary to create geometric data using the reverse modeling method described above and perform a FEM simulation. As a technique for reflecting the actual shape in the FEM simulation, a technique is known in which a simulation model is prepared in advance and the one that is closest to the measured actual shape is selected to perform an accurate FEM simulation (see, for example, Patent Document 1). In addition, a technique is known in which a feature diagram that indirectly reflects the actual shape is used to compare the pre-prepared FEM simulation results with the measured feature diagram, and the simulation model is corrected based on the difference (see, for example, Patent Document 2). [Prior art documents] [Patent Documents]
[0004] [Patent Document 1] Patent No. 6740167 [Patent Document 2] Japanese Patent Publication No. 2006-232064 [Overview of the project] [Problems that the invention aims to solve]
[0005] Incidentally, the technology described in Patent Document 1 involves selecting a pre-prepared simulation model, so discrepancies with the actual shape are unavoidable. Furthermore, the technology described in Patent Document 2 does not directly compare the actual shape, but rather compares it with a feature diagram that indirectly reflects the actual shape, so it is not guaranteed to accurately reflect the actual shape either.
[0006] Furthermore, if a product or structure has a relatively simple shape, such as one composed of planes, it can often be automatically converted into geometric data using the automatic generation function of data processing software. However, if it is composed of complex curved surfaces or has a helical shape, such as a coil spring, the automatic generation function cannot produce high-quality geometric data. In particular, when the purpose is to use the geometric data for FEM simulation, it is desirable that the feature lines follow the shape of the product or structure, but the automatic generation function generally does not produce such results. Therefore, it is necessary for operators to create the geometric data using manual generation functions, which consumes a lot of manpower and makes it difficult to create geometric data efficiently.
[0007] The present invention has been made in view of the above, and aims to provide a data creation program, a data creation device, and a data creation method that can efficiently create geometric data that accurately reflects the actual shape. [Means for solving the problem]
[0008] To solve the above-mentioned problems and achieve the objective, the data creation program according to the present invention is characterized by causing a computer to perform the following steps: a parameter setting step of setting a first design variable, which is a shape parameter that represents the wire cross-sectional shape according to the design value of the coil spring, and a second design variable, which is a shape parameter that represents the wire cross-sectional shape within the tolerance range set for the design value, for each wire cross-section; a selection step of selecting a design variable for each wire cross-section by comparing the three-dimensional scan data of the target structure with the shape parameter; and a data creation step of creating geometric data based on the selected design variable.
[0009] Furthermore, the data creation program according to the present invention is characterized in that, in the above invention, the parameter setting step divides the tolerance range under predetermined conditions and generates the second design variable for each of the divided ranges.
[0010] Furthermore, the data creation program according to the present invention is characterized in that, in the above invention, the selection step selects a design variable for the wire cross-section based on the distance between a first set point of the wire cross-section in the three-dimensional scan data and a second set point of the wire cross-section based on the first or second design variable.
[0011] Furthermore, the data creation program according to the present invention is characterized in that, in the above invention, the design variables representing the cross-sectional shape of the wire are set with respect to the wire cross-section using orthogonal coordinates with the center position of the wire cross-section as the origin.
[0012] Furthermore, the data creation program according to the present invention is characterized in that, in the wire cross section, a circle tangent to the outer edge of the wire cross section is set, and the following are set as design variables to represent the shape of the wire cross section: the coordinates of the center position of the circle, the diameter of the circle consisting of the length of the major axis and the length of the minor axis of the circle, the coordinates of the point of contact between the outer edge of the wire cross section and the circle, and the orientation of the circle.
[0013] Further, the data creation device according to the present invention includes a first shape parameter including design variables representing the cross-sectional shape of the wire corresponding to the design value of the coil spring, and a second shape parameter including design variables representing the cross-sectional shape of the wire within the tolerance range set for the design value. A parameter setting unit that sets the shape parameters for each wire cross-section, a selection unit that compares the three-dimensional scan data of the target structure with the first and second shape parameters for each wire cross-section and selects a shape parameter, and a geometry data creation unit that creates geometry data based on the selected shape parameter. It is characterized by comprising.
[0014] Further, the data creation method according to the present invention is a data creation method for creating geometry data of a coil spring, including a first shape parameter including design variables representing the cross-sectional shape of the wire corresponding to the design value of the coil spring, and a second shape parameter including design variables representing the cross-sectional shape of the wire within the tolerance range set for the design value. A parameter setting step of setting the shape parameters for each wire cross-section, a selection step of comparing the three-dimensional scan data of the target structure with the first and second shape parameters for each wire cross-section and selecting a shape parameter, and a data creation step of creating geometry data based on the selected shape parameter. It is characterized by including.
Advantages of the Invention
[0015] According to the present invention, there is an effect that a coil spring design that meets the requirements can be performed regardless of the cross-section and pitch of the wire.
Brief Description of the Drawings
[0016] [Figure 1] FIG. 1 is a block diagram showing a schematic configuration of a geometry data creation device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a diagram (part 1) for explaining the definition of the basic shape of a coil spring in an embodiment of the present invention. [Figure 3]FIG. 3 is a diagram (Part 2) for explaining the definition of the basic shape of a coil spring in one embodiment of the present invention. [Figure 4] FIG. 4 is a diagram (Part 1) showing an example of a coil spring. [Figure 5] FIG. 5 is a diagram (Part 2) showing an example of a coil spring. [Figure 6] FIG. 6 is a diagram (Part 1) for explaining parameters representing the cross-sectional shape of a coil spring wire. [Figure 7] FIG. 7 is a diagram (Part 2) for explaining parameters representing the cross-sectional shape of a coil spring wire. [Figure 8] FIG. 8 is a diagram (Part 3) for explaining parameters representing the cross-sectional shape of a coil spring wire. [Figure 9] FIG. 9 is a flowchart for explaining an overview of a geometry data creation method performed by a geometry data creation device according to one embodiment of the present invention. [Figure 10] FIG. 10 is a diagram for explaining the selection of design variables performed by a geometry data creation device according to one embodiment of the present invention. [Figure 11] FIG. 11 is a diagram for explaining the creation of conventional geometry data.
Embodiments of the Invention
[0017] Hereinafter, embodiments for implementing the present invention (hereinafter referred to as "embodiments") will be described with reference to the accompanying drawings. Note that the drawings are schematic, and the relationship between the thickness and width of each part, the ratio of the thickness of each part, etc. may be different from the actual ones, and there may be parts where the dimensional relationship and ratio are different between the drawings.
[0018] (Embodiment) Figure 1 is a block diagram illustrating the schematic configuration of a geometry data creation device according to one embodiment of the present invention. The geometry data creation device 1 shown in Figure 1 selects optimal shape parameters from information regarding the shape of a coil spring to create geometry data. Based on this geometry data, it performs analysis and simulation on a product virtually modeled on a computer, thereby providing CAE (Computer Aided Engineering) functionality to support product design and development. The geometry data creation device 1 includes an input unit 11, a parameter setting unit 12, a selection unit 13, a geometry data creation unit 14, an output unit 15, a storage unit 16, and a control unit 17.
[0019] The input unit 11 receives various signals related to the operation of the geometry data creation device 1. The input unit 11 is configured using a keyboard, mouse, switch, touch panel, etc.
[0020] The parameter setting unit 12 sets shape parameters that represent the shape of the coil spring for the mesh data of the structure for which geometry data is to be created. These shape parameters include design values and design variables necessary for designing the coil spring, such as the cross-sectional shape of the wires and the pitch of the coil spring. Multiple design variables necessary for designing a single coil spring are paired according to the cross-section of the wires, and the shape parameters are composed of these paired design variables. The mesh data is data generated using a 3D scanner or 3D digitizer, and is data that represents the surface shape of the structure using planar elements.
[0021] Here, the shape parameters and design variables of a coil spring will be explained with reference to Figures 2 to 8. First, the definition of the basic shape of a coil spring will be explained. Figures 2 and 3 are diagrams illustrating the definition of the basic shape of a coil spring in one embodiment of the present invention. Figures 4 and 5 are diagrams showing an example of a coil spring. Figures 3 to 5 show an example where the cross-sectional shape of the wire (strand) forming the coil spring is circular.
[0022] As shown in Figure 2, the coil spring 100 is formed by winding strands of wire in a spiral shape. In this case, the line extending along the center of the strand is called the center line, and the cross-section with a plane perpendicular to this center line as the cutting plane is called the strand cross-section. Specifically, in the coil spring 100, as shown in Figure 3, a center line 110 is set in the strand that passes through a plurality of centers 111 located at predetermined length intervals and extends along each of the centers 111 of the strand, and a strand cross-section 120 is set, for example, at the end of the strand, with a plane perpendicular to the center line 110 as the cutting plane. Here, one turn is defined as one rotation of the center line 110 in the circumferential direction, and the number corresponding to the number of rotations is counted as the turn number. For example, the position where the strand (center line) has made three rotations from one end is called the third turn. The basic shape of the coil spring is defined by associating the center line coordinates and the strand cross-sectional shape (shape parameters) with the turn numbers.
[0023] For coil springs with a circular wire cross-section, in addition to the definition of the basic shape, the number of turns, the diameter of the wire, the average diameter of the coil, and the distance between centerlines (pitch) are defined. For example, the coil spring 101 shown in Figure 4 has design values of 5 turns, a wire diameter of 3.2, an average coil diameter of 24, and a distance between centerlines of 5.2. Similarly, the coil spring 102 shown in Figure 5 has design values of 10 turns, a wire diameter of 2.2, an average coil diameter of 20, and a distance between centerlines of 2.7. Note that for shapes other than a circle, the diameter of the wire is set, for example, as the diameter of the circumscribed circle that circumscribes the cross-section of the wire.
[0024] Here, the parameters for representing the cross-sectional shape of the wire strands will be explained with reference to Figures 6 to 8. Figures 6 to 8 are diagrams for explaining the parameters for representing the cross-sectional shape of the wire strands of a coil spring. First, as shown in Figure 6, a Cartesian coordinate system is set for the wire strand cross-section, with the center (centroid) position P0 of the wire strand cross-section as the origin, and mutually orthogonal X and Y directions. In addition, a circle (including ellipses, perfect circles, and ovals) that is tangent to the outer edge of the wire strand cross-section is set. For example, as shown in Figure 6, the outer edge consists of two sets (four) of two parallel straight sections arranged to be orthogonal to each other, and four curved sections that connect the different sets of straight sections, and circles that are tangent to the ends of each curved section are set. The center positions of each circle are Pc1 to Pc4, and the positions where the circle and the wire strand cross-section are tangent (points of contact) are P1 to P8. For example, the points of contact of the circle with center position Pc1 are positions P1 and P2. Furthermore, the coordinates of the center position Pc1 are (Xc1, Yc1). The coordinates of position P1 are (X1, Y1). The diameter of this circle (hereinafter simply referred to as "circle diameter") can be expressed by the length of the major axis and the length of the minor axis, which here is (Rx1, Ry1). In addition, the angle between the X direction and the major axis is θ1, and this angle θ1 is the orientation of the circle. Similarly, the coordinates, circle diameter, and circle orientation are set for the circles at center positions Pc2 to Pc4. By setting various design variables at each center position, shape parameters representing the wire cross section are set. By setting these shape parameters for each wire cross section, the shape at each wire cross section position can be set.
[0025] For example, if the cross-section of the wire is a circle and the diameter D1 is set to 4 (see Figure 7), each design variable can be expressed as follows: Center position: Pc1~Pc4=(0,0) Orientation of the circle: θ1~θ4=0° Circle diameter:(Rx1,Ry1)~(Rx4,Ry4)=(2,2) Point of contact: (X1,Y1)=(X8,Y8)=(2,0) (X2,Y2)=(X3,Y3)=(0,-2) (X4,Y4)=(X5,Y5)=(-2,0) (X6,Y6)=(X7,Y7)=(0,2)
[0026] Furthermore, if the cross-section of the wire is a shape in which a part of a circle, such as a seat coil formed at the end of the wire, is cut out, and the diameter D1 of the virtual circle formed along the outer edge is set to 4 and the radial length D2 of the cross-section is set to 1 (see Figure 8), then each design variable can be expressed as follows. Center position: (Xc1,Yc1)=(√2,1) (Xc2,Yc2)=(-√2,1) (Xc3,Yc3)=(Xc4,Yc4)=(0,0) Orientation of the circle: θ1~θ4=0° Circle diameter:(Rx1,Ry1)=(Rx2,Ry2)=(0,0) (Rx3,Ry3)=(Rx4,Ry4)=(2,2) Point of tangency: (X1,Y1)=(X2,Y2)=(X8,Y8)=(√2,1) (X3,Y3)=(X4,Y4)=(X5,Y5)=(-√2,1) (X6,Y6)=(X7,Y7)=(0,2)
[0027] In addition to the shapes described above, the cross-sectional shape of the wire strands can also be represented using the shape parameters described above, even for ellipses, ovals, rectangles, and other shapes. Examples of other shapes include a shape that forms an outer edge consisting of two pairs (four) of straight sections, each pair of straight sections that are non-parallel and facing each other, arranged in different directions, and four curved sections that connect the straight sections of the different pairs, or a shape formed by connecting multiple curved sections that extend with different radii of curvature.
[0028] The parameter setting unit 12 generates parameters according to the tolerance range set in the design of the coil spring, in addition to the parameters set as described above. That is, the parameter setting unit 12 sets parameters corresponding to the design drawing, including design variables for each position of each wire cross section and design variables set according to the tolerance range. Here, the tolerance range is a numerical range set according to the dimensions that are permissible for the product, relative to the design values of the structure to be manufactured.
[0029] The parameter setting unit 12 divides the tolerance range according to predetermined conditions, for example, dividing it into 10 equal sections, and sets design variables for each tolerance. Specifically, the angle θ1 to θ4 is set to a tolerance range of ±10°, and this tolerance range (a range of 20° with the design value as the median) is divided into 10 sections, and design variables for the wire cross section of the median value of each divided section are generated. For example, the center position (e.g., (Xc1, Yc1)) is changed to correspond to the median value after division. As a result, for each wire cross section, a first shape parameter is set using design variables corresponding to the design drawing, and a second shape parameter is set using multiple sets (10 sets in the case of 10 divisions) of design variables (variations) according to the tolerance range. As a way of setting variations of design variables based on the tolerance range, for example, design variables based on the ratio of the length of the major axis and the length of the minor axis may be generated. In the case of the length of the major axis and the length of the minor axis and the ratio, for example, the tolerance range is set to ±3% of the ratio. Furthermore, the division is not limited to the angle division described above; other parameters can also be divided. Another example of division is to divide the tolerance range into finer parts, considering manufacturing experience, for the range that is more likely to be achieved, and into coarser parts for the range that is less likely to be achieved.
[0030] Returning to Figure 1, the selection unit 13 compares the mesh data with the parameters (design variables) set by the parameter setting unit 12 and selects the design variables that increase the reproducibility of the mesh data.
[0031] The geometry data creation unit 14 creates geometry data composed of parameters selected by the selection unit 13 at each wire cross-section position.
[0032] The output unit 15, under the control of the control unit 17, displays images or outputs sound and light. The output unit 15 is composed of a display, speaker, light source, etc.
[0033] The memory unit 16 stores programs (for example, a geometry data creation program, which will be described later) for the control unit 17 to perform various operations. The memory unit 16 also has a design variable memory unit 161 that stores design variables. The design variable memory unit 161 stores various design variables associated with each wire cross section. The memory unit 16 is configured using volatile memory and / or non-volatile memory, or a combination thereof. For example, the memory unit 16 is configured using RAM (Random Access Memory), ROM (Read Only Memory), etc.
[0034] The control unit 17 controls the operation processing of each component of the geometry data creation device 1. For example, when the control unit 17 receives an instruction input via the input unit 11 to start the geometry data creation process, it causes each unit to execute the process. The control unit 17 also causes the geometry data creation unit 14 to output the geometry data or information related to its shape to the output unit 15.
[0035] The parameter setting unit 12, the selection unit 13, the geometry data creation unit 14, and the control unit 17 are each configured using processors such as a CPU (Central Processing Unit) or various arithmetic circuits that perform specific functions, such as an ASIC (Application Specific Integrated Circuit).
[0036] Next, the geometry data creation process will be explained with reference to Figure 9. Figure 9 is a flowchart illustrating the outline of the method for selecting the optimal design proposal performed by a geometry data creation device according to one embodiment of the present invention. When the control unit 17 receives an instruction input to start the geometry data creation process, for example via the input unit 11, it causes each unit to execute the process.
[0037] First, the control unit 17 acquires mesh data (step S101). The control unit 17 acquires the mesh data of the structure for which geometric data is to be created.
[0038] Thereafter, the parameter setting unit 12 acquires the center line of the mesh data (step S102). The parameter setting unit 12 sets a line extending along each center in the mesh data as the center line. At this time, the parameter setting unit 12 sets a cross section with a plane orthogonal to this center line as the cutting plane as the generatrix cross section. Each generatrix cross section set from the mesh data is described as being assigned different numbers n (1 to n MAX :n MAX corresponding to, for example, the total number of generatrix cross sections).
[0039] The parameter setting unit 12 sets the number n of the generatrix cross section to n = 1 (step S103).
[0040] Thereafter, for the n-th generatrix cross section, the parameter setting unit 12 sets shape parameters composed of first design variables based on the design values. Also, the parameter setting unit 12 generates second design variables according to the tolerance range and sets shape parameters including the second design variables. As a result, a plurality of sets of shape parameters respectively constituted by the first and second design variables and representing the shape of the generatrix cross section are created.
[0041] After parameter setting, the selection unit 13 compares the mesh data with each shape parameter and selects design variables (step S105). FIG. 10 is a diagram for explaining the selection of design variables performed by the geometric data creation device according to an embodiment of the present invention. The selection unit 13 selects a first setting point S M in a certain generatrix cross section S of the mesh data M1 S M2 S M3 S M4 ···, and a generatrix cross section S SThe second setting point S in S1 S S2 S S3 S S4 Regarding ..., the corresponding setting points (for example, setting point S M1 and S S1 The distance between the two points is calculated, and the combination of design variables that minimizes the sum of the distances between each corresponding setpoint is selected. The second setpoint is the point closest in distance to the first setpoint.
[0042] Returning to Figure 9, the control unit 17 increases n by 1 (step S106). Then, the control unit 17 checks when n is n MAX It is determined whether n is greater than or equal to (step S107). The control unit 17 determines whether n is greater than or equal to n MAX If it is determined that the following is true (step S107: No), the process proceeds to step S104, and the above process is repeated for the nth element after the increment. Meanwhile, the control unit 17 determines that n is n MAX If it is determined to be larger (Step S107: Yes), proceed to Step S108.
[0043] In step S108, the geometry data creation unit 14 creates geometry data using the design variables selected for each wire cross-section. The geometry data creation unit 14 creates geometry data using a program for creating an analysis model of the coil spring. A known program can be used for creating this analysis model of the coil spring.
[0044] After creating the geometry data, the control unit 17 may, for example, display the created geometry data on the output unit 15 or store it in the storage unit 16.
[0045] In the embodiment described above, the cross-sectional shape corresponding to the scan data is selected using the design variables of the wire cross-section corresponding to the design value and the design variables of the wire cross-section corresponding to the tolerance range for the design value, and geometric data is created for each cross-section according to the shape parameters selected. According to this embodiment, variations of the cross-sectional shape parameters are created within the tolerance range, and shape parameters suitable for the scan data are selected from among these shape parameters for each cross-section, so that geometric data that accurately reflects the actual shape can be efficiently created. In this case, the more design variables there are in the tolerance range (for example, the larger the number of divisions), the higher the accuracy with respect to the actual shape can be.
[0046] Furthermore, according to this embodiment, since the creation of the geometry data described above is performed by a computer, the geometry data can be created efficiently and in a relatively short amount of time.
[0047] Furthermore, in this embodiment, the geometry data created by the method described above can be used for FEM (Finite Element Method) analysis. Therefore, according to this embodiment, the process from creating the geometry data to simulating the said geometry data can be carried out seamlessly.
[0048] Furthermore, according to this embodiment, it is possible to change the cross-sectional shape (shape parameter) for each winding, and even for coil springs where the cross-sectional shape differs depending on the winding, it is possible to create geometry data that accurately reflects the actual shape.
[0049] In this embodiment, an example of selecting shape parameters for each cross-section has been described. However, it is also possible to create multiple provisional shape models (provisional models) in which shape parameters have been set in advance for each cross-section, and then select the model that is closest to the mesh data from among these provisional models. In this case, the selection unit 13 calculates, for example, the sum of the distances between the set points of the mesh data and the provisional model, and selects the provisional model with the smallest sum. Note that, in addition to the sum of the distances between the set points of the mesh data and the provisional model, other statistical values such as cumulative values, mode, and mean may also be used.
[0050] Furthermore, the program to be executed by the geometry data creation device relating to this entity is provided, for example, as a file data in an installable or executable format, recorded on a computer-readable recording medium such as a CD-ROM, flexible disk (FD), CD-R, DVD (Digital Versatile Disk), USB media, or flash memory.
[0051] Furthermore, the program to be executed by the geometry data creation device according to this embodiment may be stored on a computer connected to a network such as the Internet and provided by being downloaded via the network.
[0052] Furthermore, the geometry data creation device according to this embodiment can function as a server device and be configured to send and receive information with external terminals connected via a network.
[0053] While embodiments for carrying out the present invention have been described so far, the present invention should not be limited to the embodiments described above.
[0054] Thus, the present invention may include various embodiments not described herein, and various design modifications can be made without departing from the technical idea specified by the claims.
[0055] As described above, the data creation program, data creation apparatus, and data creation method according to the present invention are suitable for efficiently creating geometric data that accurately reflects the actual shape. [Explanation of symbols]
[0056] 1. Geometry data creation device 11 Input section 12 Parameter setting section 13 Selection Section 14. Geometry Data Creation Section 15 Output section 16 Memory section 17 Control Unit 100, 101, 102 coil springs 110 Center line 111 Center 120 Wire cross section 161 Design Variable Storage Unit
Claims
1. On the computer, A parameter setting step in which a first design variable, which is a shape parameter that represents the wire cross-sectional shape according to the design value of the coil spring, and a second design variable, which is a shape parameter that represents the wire cross-sectional shape within the tolerance range set for the design value, are set for each wire cross-section, For each wire section, a selection step is performed to compare the three-dimensional scan data of the target structure with the shape parameters and select design variables. A data creation step that creates geometric data based on selected design variables, A data creation program characterized by causing the execution of [a specific action].
2. The parameter setting step involves dividing the tolerance range according to predetermined conditions and generating the second design variable for each of the divided ranges. The data creation program according to feature 1.
3. The selection step selects a design variable for the wire cross-section based on the distance between a first setpoint of the wire cross-section in the three-dimensional scan data and a second setpoint of the wire cross-section based on the first or second design variable. The data creation program according to feature 1.
4. The design variables representing the cross-sectional shape of the wire strand are set using orthogonal coordinates with the origin at the center of the wire strand cross-section. The data creation program according to feature 1.
5. In the aforementioned cross-section of the wire, a circle tangent to the outer edge of the cross-section of the wire is defined. The design variables used to represent the cross-sectional shape of the wire strand are: the coordinates of the center of the circle, the diameter of the circle consisting of the length of the major axis and the length of the minor axis, the coordinates of the point of contact between the outer edge of the wire strand cross-section and the circle, and the orientation of the circle. The data creation program according to feature 4.
6. A parameter setting unit sets a first shape parameter for each wire cross-section, which includes a design variable that represents the wire cross-sectional shape according to the design value of the coil spring, and a second shape parameter that includes a design variable that represents the wire cross-sectional shape within the tolerance range set for the design value. For each wire cross section, a selection unit compares the three-dimensional scan data of the target structure with the first and second shape parameters and selects the shape parameters. A geometry data creation unit that creates geometry data based on selected shape parameters, A data creation device characterized by comprising the following features.
7. A method for creating data to generate the geometry data of a coil spring, A parameter setting step in which a first shape parameter, which includes a design variable that represents the wire cross-sectional shape according to the design value of the coil spring, and a second shape parameter, which includes a design variable that represents the wire cross-sectional shape within the tolerance range set for the design value, are set for each wire cross-section, For each wire cross section, a selection step is performed to compare the three-dimensional scan data of the target structure with the first and second shape parameters and select the shape parameters. A data creation step that creates geometric data based on selected shape parameters, A data creation method characterized by including the following.