Machining path generation device, machining path generation method, and workpiece production method

Abstract

To improve the dimensional accuracy of a finished product, an intermediate product, etc., produced by processing a workpiece, which is a workpiece to prevent a machining tool from troubles .SOLUTION: A processing path generation device that generates a processing path for processing a workpiece, includes: a communication unit that receives workpiece information of the workpiece and tool information of a tool that processes the workpiece; and a processing unit connected to the communication unit. The processing unit generates a processing shape for a removal portion to be removed from the workpiece, based on the workpieces information and the tool information received by the communication unit, divides the generated processing shape into a plurality of division elements; estimates respective rigidities of the plurality of division elements; and selects one of the plurality of processing paths, based on the estimated rigidities of the division elements.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a machining path generation device, a machining path generation method, and a workpiece production method.

Background Art

[0002] As background art in this technical field, there is Japanese Patent Application Laid-Open No. 2018-32157 (Patent Document 1). This publication states, "The present invention aims to provide a method for generating a numerical control program, an element creation method, a numerical control program generation system, and a numerical control program generation program that can set machining conditions according to the machining shape and create a tool path in which the path of the machining operation is coded according to the machining shape. A method for generating a numerical control program for controlling the machining operation performed during machining of a material, comprising: an element creation step of creating elements related to the shape of the material based on a material design model that is a design model of the material by executing a computer-aided design program; an element reading step of reading the elements created by the computer-aided design program into a computer-aided manufacturing program; a tool path creation step of executing the computer-aided manufacturing program to create a tool path in which the path of the machining operation is coded for each of the read elements; and a tool path connection step of executing the computer-aided manufacturing program to create a numerical control program by connecting the created tool paths."

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the technique described in Patent Document 1, the rigidity of the removed portion removed by machining is not considered. That is, it does not have a function of evaluating the quality of the machining path based on the rigidity of the machining shape constituting the removed portion and determining the machining path from a plurality of machining path candidates. Therefore, dimensional accuracy of a finished product, an intermediate product, etc. produced by machining from the workpiece to be machined cannot be expected. The present invention has been made in view of such a situation, and an object thereof is to provide a technique for improving the dimensional accuracy of a finished product, an intermediate product, etc. produced by machining.

[0005] Also, an object is to generate a machining path that avoids a decrease in the rigidity of the removed portion due to machining and suppresses the occurrence of defects from a plurality of machining path candidates. Here, a defect is a defect caused by machining, and typical ones include deformation and breakage of the workpiece and malfunction of the machine tool.

[0006] Furthermore, an object is to provide a method for producing a finished product by machining a workpiece with a machining path that avoids a decrease in the rigidity of the removed portion due to machining and suppresses the occurrence of defects from a plurality of machining path candidates.

Means for Solving the Problems

[0007] To solve the above problems, for example, the configuration described in the claims is adopted. This application includes a plurality of means for solving the above problems. As an example, a machining path generation device that generates a machining path for machining a workpiece, the machining path generation device having a communication unit that receives workpiece information of the workpiece and tool information of a tool for machining the workpiece, and a processing unit connected to the communication unit. The processing unit generates a machining shape of a removed portion removed from the workpiece based on the workpiece information and the tool information received by the communication unit, divides the generated machining shape into a plurality of divided elements, estimates the rigidity of the plurality of divided elements, and selects one of the plurality of machining paths based on the estimated rigidity of the divided elements.

Effects of the Invention

[0008] According to the present invention, it is possible to improve the dimensional accuracy of finished products, intermediate products, etc. generated by processing from the workpiece to be processed.

[0009] In addition, when machining the workpiece, it is possible to avoid a decrease in the rigidity of the portion removed by a single machining or the remaining workpiece portion after machining, suppress the occurrence of defects, and perform machining.

[0010] Furthermore, from a plurality of machining path candidates, it is possible to machine the workpiece with a machining path that avoids a decrease in the rigidity of the machining removal portion and suppresses the occurrence of defects, and produce a finished product. Problems, configurations, and effects other than those described above will be clarified by the description of the following embodiments.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3A

Figure 3B

Figure 3C

Figure 3D

Figure 4A

Figure 4B

Figure 4C

Figure 4D

Figure 5

Figure 6A

Figure 6B

Figure 7A

Figure 7B

Figure 8A

Figure 8B

Figure 9A

Figure 9B

Embodiments for Carrying Out the Invention

[0012] Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. In all the drawings for explaining each embodiment, the same members are basically denoted by the same reference numerals, and repeated explanations thereof are omitted.

[0013] In the following description, when explaining the processing with "program" or functional blocks as the subject, since the program performs the defined processing by being executed by the CPU, the subject of the processing may be the CPU instead of the program or functional blocks.

Examples

[0014] <Configuration of the Machining Path Generation Device 10> FIG. 1 shows a hardware block diagram of the machining path generation device 10 according to Embodiment 1 of the present invention. The machining path generation device 10 of the present invention prevents defects in the finished product or intermediate product after cutting by evaluating the rigidity of the removed portion removed in each machining. Here, the defect is a defect caused by machining, and typical ones include deformation or breakage of the work material and failure of the machine tool.

[0015] Hereinafter, the object to be machined is referred to as the workpiece, the portion removed by machining is referred to as the removed portion, and the one having the shape obtained by machining is referred to as the finished product or the processed object. However, in the following specification, the finished product is an article having a shape obtained by machining, and is not necessarily the final form of the product form.

[0016] Among the removed portions, by minimizing the reduction in rigidity of the portion removed by a single machining or the removed portion remaining after machining, the occurrence of defects is suppressed, and a cutting machining path that can be machined more stably is generated. Then, the machining path generation device 10 converts the generated cutting machining path into a numerical control program for controlling a numerically controlled (NC) machine tool and outputs it to the NC machine tool. In the case where the NC machine tool has a function of changing the cutting machining path into a numerical control program, the cutting machining path may be output from the machining path generation device 10 to the NC machine tool.

[0017] Further, the cutting machining path includes the removal path of the workpiece by the cutting tool and the tool conditions. The tool conditions are information including the type of the cutting tool, the rotational speed of the cutting tool, the feed rate of the cutting tool, and the like. Hereinafter, the cutting machining path may be referred to as the machining path.

[0018] The machining path generation device 10 has a configuration similar to that of a general computer such as a personal computer, and includes a processor such as a CPU (Central Processing Unit) that constitutes the processing unit 11, a memory such as a DRAM (Dynamic Random Access Memory) that constitutes the storage unit 12, a storage such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive), an input device such as a keyboard, a mouse, and a touch panel that constitute the input unit 13, an output device such as a display that constitutes the output unit 14, and a communication module such as a NIC (Network Interface Card) that constitutes the communication unit 15. The processing unit 11, the storage unit 12, the input unit 13, the output unit 14, and the communication unit 15 are connected to each other by a connecting device (not shown) such as a bus.

[0019] The processing unit 11 comprises functional blocks of an information acquisition processing unit 111, a machining path generation unit 112, a machining path evaluation unit 113, a machining condition adjustment unit 114, and a conversion unit 115. These functional blocks are realized by a computer's processor executing a predetermined program loaded into the memory. The information acquisition processing unit 111, the machining path generation unit 112, the machining path evaluation unit 113, and the machining condition adjustment unit 114 may be provided as one machining path generation program. Further, the machining path generation program may include a program for realizing the function of the conversion unit 115. Part or all of these functional blocks may be realized as hardware by an integrated circuit or the like.

[0020] The communication unit 15 receives the workpiece information 121 from the outside such as CAD (Computer Aided Design) and the tool information 122 from the outside such as an NC machine tool, and transmits them to the information acquisition processing unit 111.

[0021] The information acquisition processing unit 111 acquires the workpiece information 121 via the communication unit 15 and stores it in the storage unit 12. The workpiece information 121, as information on the workpiece, includes, for example, the shape of the workpiece before machining, the material of the workpiece, the shape of the cutting portion on the workpiece, the shape of the finished product after cutting, the fixing method of the workpiece, and part or all of the fixing location of the workpiece, etc., supplied from an information medium having material information such as a CAD model.

[0022] Further, the information acquisition processing unit 111 acquires the tool information 122 from an NC machine tool for machining the workpiece or a tool management program file associated with the NC machine tool and stores it in the storage unit 12. The tool information 122, as tool information for machining the workpiece, includes, for example, part or all of the outer diameter of the cutting tool, the protruding length, the available material, the number of tool edges, the twist angle of the tool, and the machining method and machining conditions assigned to the tool.

[0023] Based on the workpiece information 121 and the tool information 122 acquired by the information acquisition processing unit 111, the machining path generation unit 112 selects the tool to be used. Further, the machining path generation unit 112 generates a machining path 1 that is a candidate for the machining path, and stores it in the storage unit 12 as the machining path information 123. The machining path 1 includes, in addition to the removal path of the workpiece by the cutting tool, information such as the type of cutting tool indicating the machining conditions, the rotational speed of the cutting tool, and the feed rate of the cutting tool. Since the machining path 1 may include a plurality of machining paths before being transmitted to the NC machine tool, it is treated as a provisional machining path.

[0024] The method for selecting the tool to be used will be described later. Note that it is desirable to make the angle of the advancing direction of the cutting tool and the types of the contact methods between the tool and the workpiece discrete and finite values so that the number of generated machining paths 1 becomes a realistic value. The details of the machining path generation method will be described later.

[0025] The machining path evaluation unit 113 estimates the rigidity of the removal part from the workpiece information 121 and the machining path information 123. The rigidity of the removal part includes the rigidity of the part to be machined in one pass and the part to be machined remaining after machining within the removal part. The machining path evaluation unit 113 sets the priority order of the machining path 1 from the machining efficiency, noise level, energy consumption, etc., estimates and evaluates the rigidity of the removal part when machined according to the priority order. The method for estimating the rigidity will be described later. Further, the machining path evaluation unit 113 compares the rigidity of the removal part for each of the plurality of machining paths included in the machining path 1, and adopts one from the machining path 1 based on the comparison result.

[0026] When it is determined by the evaluation of the machining path evaluation unit 113 that determines whether the machining path is adoptable that machining cannot be performed under the machining conditions of the tool information 122, the machining condition adjustment unit 114 adjusts the machining conditions of the machining path 1 to generate a machining path 2, and stores it in the storage unit 12 as the machining path information 123.

[0027] The conversion unit 115 converts one of the machining paths 1 adopted by the machining path evaluation unit 113 or the machining path 2 whose machining conditions are adjusted by the machining condition adjustment unit 114 into an NC program. Note that when the NC machine tool has the function of the conversion unit 115, the machining path generation device 10 may not have a conversion unit. In this case, the information of the machining path 1 adopted by the machining path evaluation unit 113 or the machining path 2 whose machining conditions are adjusted by the machining condition adjustment unit 114 is output to the NC machine tool.

[0028] The storage unit 12 stores the above-described workpiece material information 121, tool information 122, and machining path information 123. Note that the storage unit 12 may store information other than the above-described information.

[0029] The input unit 13 receives various operations from the user. The output unit 14 displays, for example, a screen (not shown) representing the generated machining path. The communication unit 15 connects to a computer that outputs a CAD model, an NC machine tool, etc. via a predetermined network such as the Internet or a mobile phone communication network and communicates various data.

[0030] <Tool selection> Next, a tool selection method by the machining path generation unit 112 will be described.

[0031] FIG. 2 shows a flowchart of tool selection for machining path generation by the machining path generation unit 112 of the machining path generation device 10.

[0032] The machining path generation unit 112 determines the conditions for usable tools (S1), taking the workpiece material information 121 and the tool information 122 acquired by the information acquisition processing unit 111 as input information. At this time, a usage priority is set in advance for the tools included in the tool information 122. This is based on the experience of the operator, the learning results, and the usage frequency. First, refer to the tool information 122 and set the usage conditions for each tool. For example, a drill with a tool diameter of 10 mm is adopted when the tool is applied perpendicularly to the surface of the workpiece material to machine a round hole with a hole diameter of 10 mm, and so on. In step (S1), using the workpiece material information 121, determine the conditions for the selected usable tool (temporarily selected tool). A temporarily selected tool is one that can machine the workpiece material and geometrically create a completed shape. Specifically, refer to the relationship between the cutting edge length of the temporarily selected tool and the required cutting depth, the relationship between the shape of the temporarily selected tool and the roundness of the machined shape, etc.

[0033] Next, the machining path generation unit 112 temporarily selects a usable tool with reference to the usage conditions of the tool information 122 according to the conditions of the usable tools determined in step (S1) in step (S2).

[0034] In step (S2), a plurality of tools may be temporarily selected, or it may be uniquely determined. However, if there is no temporarily selected tool, output the conditions for usable tools.

[0035] Finally, the machining path generation unit 112 adopts the tool with the highest priority as the used tool from the temporarily selected tools in step (S3) and acquires the tool information 122 of the adopted tool.

[0036] As described above, the tool may be arbitrarily selected by the operator in addition to being selected by the machining path generation device 10.

[0037] <Machining Path Generation> Next, the machining path generation method by the machining path generation unit 112 will be described. The machining path generation unit 112 generates a machining path using the workpiece material information 121 and the tool information 122. First, the shape of the portion to be removed by machining is extracted from the workpiece material information 121. Hereinafter, the shape of the removed portion removed by machining is referred to as the machining shape.

[0038] Next, the shape of the divided element is set from the tool information 122. The shape of the divided element is the shape that can be removed by one movement of the tool. One movement refers to the period from the start of movement until the movement direction of the tool changes with an angle. When moving on a curve such as arc cutting, it is from the start of movement to the end point of the curve.

[0039] The machining shape is divided using the shape of the removed portion (machining shape) removed by machining and the shape of the divided element. At this time, it is advisable to limit the number of divisions and the division direction so that the division method becomes a realistic number.

[0040] In FIG. 3A, the workpiece material, the removed portion, and the finished product are shown as the workpiece material B1, the shape of the removed portion (machining shape) B2, and the finished product B3, respectively. For example, when machining and removing the machining shape B2 from the workpiece material B1 as shown in FIG. 3A, as shown in FIGS. 3B - D, the machining shape is divided so that the tool movement direction D1 is perpendicular to each of the Y-axis, X-axis, and Z-axis. Here, the divided element B4 indicates the region removed by one tool movement.

[0041] Next, an order of machining is assigned to each divided element, and it is set as the removal path of the workpiece material by the cutting tool of the machining path 1. At that time, the order of connecting each divided element should be determined in consideration of machining efficiency, noise, energy load, etc., but it may be arbitrarily selected based on experience and learning results. In this way, a division method and a machining order are assigned to the machining shape and generated as the machining path 1.

[0042] <Machining Path Evaluation> Next, the method for estimating rigidity by the machining path evaluation unit 113 will be described. The machining path evaluation unit 113 estimates the rigidity of the divided elements based on the contact state between the divided elements to be machined and the workpiece to be cut in the machining order of the divided elements defined in the machining path 1. The estimation of the rigidity of the divided elements is to estimate the rigidity of the portion (specific divided element) removed by one machining within the removal portion and the rigidity of the remaining removal portion (other divided elements) after being removed by machining.

[0043] Figures 4A - D are diagrams for explaining the method of estimating rigidity using the contact state of each divided element. Figures 4A - D show, as an example, the case where the machining path 1 generated by the machining path generation unit 112 is divided in the Y direction in order to machine the machining shape B2 with respect to the workpiece B1.

[0044] First, as shown in Figure 4A, the divided elements are three that are divided in the Y direction. The machining order for removing the divided elements shown in Figure 4A is three ways as shown in Figures 4B, 4C, and 4D.

[0045] In Figure 4B, it shows that the divided elements A41, A42, and A43 are machined in this order, in Figure 4C, the divided elements B41, B42, and B43 are machined in this order, and in Figure 4D, the divided elements C41, C42, and C43 are machined in this order. However, in the example of this figure, since the machining shape is symmetric, the difference in the feed direction is not considered, but in the case of an asymmetric shape, it should be considered and a different machining order should be used.

[0046] Next, the contact state of the divided elements will be described.

[0047] Figure 4B shows a machining path that machines in order from the divided element at the most negative position in the X direction of the machining path 1, that is, the divided elements A41, A42, and A43 are machined in this order. Among each divided element, the surface (contact surface) in contact with the surrounding material is shown in color. The surrounding material is, in addition to the finished product B3, other divided elements included in the machining path 1 such as the divided element A42 with respect to the divided element A41.

[0048] The divided element A41 to be removed first has no contact between two surfaces in the XZ plane and one surface in the XY plane (the surface with the positive Z direction), and the other surfaces are contact surfaces. That is, the divided element A41 has three contact surfaces: a contact surface C1 that contacts the finished product B3 in the YZ plane, a contact surface C2 that contacts the finished product B3 in the XY plane, and a contact surface C3 that contacts the divided element A42 in the YZ plane. Similarly, since the divided element A42 to be removed second is an element that is removed after the divided element A41 is removed, the contact surface with the divided element A41 becomes a non-contact surface. Therefore, the number of contact surfaces is two: a contact surface that contacts the finished product B3 in the XY plane and a contact surface that contacts the divided element A43 in the YZ plane. The number of contact surfaces of the divided element A43 to be removed third is two: a contact surface that contacts the finished product B3 in the XY plane and a contact surface that contacts the finished product B3 in the YZ plane.

[0049] Figure 4C shows that the machining paths of the divided element B41 to be removed first and the divided element B42 to be removed second are in the same state as the divided element A41 in Figure 4B. On the other hand, since the divided element B43 to be removed third has the elements of the divided element B41 and the divided element B42 removed, the number of contact surfaces is only one. In this way, by temporarily setting the machining order for the divided elements divided by the machining path generation unit 112, the contact state of the workpiece is considered. Here, the contact state is grasped by the ratio of the contact area of each divided element with the finished product or other divided elements to the total surface area of the divided element. Based on this contact state, the rigidity of each divided element is evaluated. A larger ratio of the contact area to the total surface area of the divided element gives a better score, and a smaller ratio gives a poor score. For example, for Figure 4C, the divided element B41 and the divided element B42 are given good scores, and the element of the divided element B43 is determined to have a poor score.

[0050] The reason for scoring as described above according to the contact state is that when machining the divided elements, the larger the ratio of the contact area to the total surface area of the divided elements, the less likely it is for defects caused by machining (such as deformation or breakage of the workpiece and malfunction of the machine tool) to occur. As shown in FIG. 4B, after removing the divided elements A41 and A42, the contact surface of the remaining divided element A43 consists of only two surfaces, and the rigidity of the divided element A43 becomes smaller than that of the divided element A41. Therefore, in the finished product B3, the machining accuracy of the surface in contact with the divided element A43 deteriorates compared to the surface in contact with the divided element A41. In the first embodiment, the rigidity of each divided element, particularly the rigidity of the divided element A43 after machining the divided elements A41 and A42, is evaluated based on the ratio of the contact area to the total surface area of the divided elements.

[0051] As the contact state, in addition to the ratio of the contact area, the positional relationship between the contact surfaces can be considered. The more types of normal directions of the contact surfaces, the better the score, and the fewer the types, the worse the score. For example, in the case of FIG. 4C, since the divided elements B41 and B42 have three directions, they are highly evaluated, while the divided element B43 has only one direction and is thus poorly evaluated. This is because the more types of normal directions of the contact surfaces, the more evenly the cutting force is dispersed in each direction, preventing malfunctions of the machine tool including deformation or breakage of the workpiece and breakage of the tool. The rigidity of the remaining divided element B43 after machining the divided elements B41 and B42 in FIG. 4C is poorly evaluated.

[0052] As described above, for each machining sequence, the rigidity of the removed part is evaluated based on the contact state of the divided elements, and a machining sequence in which the rigidity of all the divided elements exceeds the threshold value and has the best score is adopted.

[0053] <Machining Path Generation> Next, FIG. 5 is a flowchart for explaining an example of the machining path generation process of the machining path generation device 10 according to the first embodiment.

[0054] It is started in response to a predetermined operation from the user. First, the information acquisition processing unit 111 acquires the workpiece information 121 from an information medium having material information such as, for example, a CAD (Computer Aided Design) model, and stores it in the storage unit 12. Further, the information acquisition processing unit 111 acquires the tool information 122 from an NC machine tool or a tool management program file associated with the NC machine tool, and stores it in the storage unit 12 (S11).

[0055] Next, the machining path generation unit 112 selects a tool to be used and determines machining conditions using the workpiece information 121 and the tool information 122 (S12). Note that the details of this step are described with reference to FIG. 2.

[0056] Next, based on the workpiece information 121 and the tool information 122, the machining shape of the removed portion to be removed from the workpiece B1 is generated, and further, the machining shape of the removed portion is divided into divided elements. Then, by combining the machining orders for the divided elements, a plurality of machining paths are generated (S13).

[0057] In order to evaluate the plurality of generated machining paths, among the plurality of paths, a machining path with a short total machining time is selected (S14). Instead of the evaluation criterion of a short total machining time, based on the workpiece information 121 and the tool information 122, the order of machining the divided elements may be determined based on at least one of machining efficiency, noise level, and energy consumption, and the machining path may be selected.

[0058] Next, the machining path evaluation unit 113 focuses on the machining paths generated by the machining path generation unit 112 in ascending order of the total machining time, and evaluates the rigidity of the divided elements removed by each machining (S15). The rigidity of the divided element to be removed is estimated based on the contact state of each divided element, as described with reference to FIG. 4.

[0059] Subsequently, it is determined whether the processing path under consideration can be adopted (S16). Here, if it is determined that the processing path under consideration cannot be adopted, the processing path evaluation unit 113 determines whether there is an unconsidered processing path remaining (S17). Here, if it is determined that there is an unconsidered processing path remaining, the process returns to step (S14), and the steps after step (S4) are repeated.

[0060] In step (S17), if it is determined that there is no unconsidered processing path remaining, the processing path evaluation unit 113 selects the processing path with the highest evaluation (S18). In step S18, the processing condition adjustment unit 114 may adjust the conditions during processing for the processing path with the highest evaluation among the processing paths determined to be non - adoptable. Note that the conditions during processing may also be adjusted by the user.

[0061] Next, the conversion unit 115 converts the processing path that the processing path evaluation unit 113 evaluated with the highest score in step (S18), or the processing path whose processing conditions were adjusted by the conversion unit 115 in step (S18), into an NC program (S19). If the NC machine tool has the function of the conversion unit, in the processing path creation device 10, step S19 can be omitted, and the information of the processing path in step S18 may be output to the NC machine tool.

[0062] The converted NC program is transmitted to the NC machine tool by the communication unit 15. The NC machine tool processes the workpiece to be machined according to the processing path transmitted from the processing path generation device 10 and generates a processed product. Also, the processing path may be converted into a program suitable for a machine at an output destination other than the NC program.

[0063] According to the first embodiment, it is possible to improve the dimensional accuracy of the finished product, intermediate product, etc. generated by processing from the workpiece to be machined. Also, when the workpiece to be machined is divided into divided elements for processing, it is possible to avoid a decrease in the rigidity of the processing target portion remaining after one - time processing among the removed portions by processing and suppress the occurrence of defects.

Embodiment

[0064] In Example 2, an example in which the machining path generation device 10 is applied not only to a workpiece with a constant material but also to a workpiece B60 having a high-rigidity portion B61 and a low-rigidity portion B62 as shown in FIG. 6A will be described.

[0065] The machining path generation device 10 of Example 2 is obtained by adding a function to consider a material rigidity parameter as a material property to the machining path evaluation unit 113 of the machining path generation device 10 of Example 1.

[0066] Among the machining path generation devices 10 in FIG. 1, the description of the configurations with the same reference numerals shown in FIG. 1 that have already been described and the portions having the same functions will be omitted. A rigidity evaluation method by the machining path evaluation unit 113 for a composite material having a high-rigidity portion B61 and a low-rigidity portion B62 will be described.

[0067] In the machining path evaluation unit 113 of Example 1, the rigidity of the divided elements was estimated using the contact state of the divided elements. In the evaluation of the machining path for a composite material (workpiece B60) having a high-rigidity portion B61 and a low-rigidity portion B62, in addition to the estimation of the rigidity of the divided elements based on the contact state, a function of evaluating the rigidity based on a material rigidity parameter corresponding to the material of the workpiece is added. Specifically, the divided elements divided for machining path generation are further divided at the material boundary position, and the rigidity is evaluated for each divided element. Specific examples of the division method and the evaluation method will be described later. FIG. 6B shows the shape of the machined workpiece (the shape of the finished product) B63.

[0068] Also, FIG. 7A shows an example of the machining shape B72 of the removed portion and the division method. The division of the machining shape B72 of the removed portion in FIG. 7A is performed by the machining path generation unit 112 shown in Example 1.

[0069] Next, the splitting element B7 is split by the material boundary line using the function of splitting by the added material boundary line. An example of the splitting method is shown in FIG. 7B. When the material boundary line and the splitting line are parallel as in this example, since the material ratio of the splitting element B7 does not change over time by processing, the high-rigidity portion B71 and the low-rigidity portion B72 shown in FIG. 7B are evaluated as one splitting element. The material rigidity parameters used for evaluation are the area ratios of the high-rigidity portion B71 and the low-rigidity portion B72 with respect to the total surface area of the splitting element. When obtaining the area ratio of the contact surface with respect to the total surface area of the splitting element based on the contact state of the splitting element due to the machining path of the composite material B70, the material rigidity parameters can be used. For example, when the contact surface is a high-rigidity portion, a high weight can be assigned, and when the contact surface is a low-rigidity portion, a low weight can be assigned to calculate the total sum of the areas of the contact surfaces with respect to the total area of the splitting element.

[0070] In addition to the area ratio, the positional relationship between the contact surfaces that can be grasped by the type of the normal direction of the contact surface can be considered.

[0071] According to Example 2, the dimensional accuracy of the finished product, intermediate product, etc. generated by processing the composite material can be improved. In addition, when the composite material is divided into splitting elements for processing, it is possible to suppress the occurrence of defects.

Example

[0072] In Example 3, an example will be described in which not only the workpiece with a constant material but also the composite material B80 having a high-rigidity portion B81 and a low-rigidity portion B82 as shown in FIGS. 8A and 8B is targeted.

[0073] Example 3 is obtained by adding a function to consider the material rigidity parameter as the material property to the machining path evaluation unit 113 of the machining path generation device 10 in Example 1.

[0074] Among the machining path generation devices 10 in FIG. 1, for the configurations with the same reference numerals shown in FIG. 1 that have already been described and the portions having the same functions, the description will be omitted. In Example 3, the splitting method and the evaluation method when the tool is moved and removed in the X direction will be described.

[0075] As shown in FIG. 8A, the case of creating a groove shape as shown in FIG. 8B from a composite material B80 having a high-rigidity portion B81 and a low-rigidity portion B82 will be described.

[0076] According to the flow shown in Example 1, the machining shape B92 is divided into divided elements B9 as shown in FIG. 9A. Next, using the function of dividing by the added material boundary line, as shown in FIG. 9B, the divided elements are further divided by the material boundary line into divided elements B91 and B92. In this example, unlike the methods shown in FIGS. 7A and 7B, since the material ratio of the divided elements changes over time, evaluation is performed for each divided element divided by the material boundary line.

[0077] The evaluations for each divided element separated by the material boundary line are summarized, the evaluation of the divided elements to be removed in one tool movement is performed, and finally, the evaluation of the machining path is obtained. Note that the method for evaluating the rigidity of the divided elements separated by the material boundary line is the same as the method shown in Example 1. To evaluate the contact state of the divided elements, using the material rigidity parameter, the divided element B91 at the high-rigidity portion is weighted highly, and the divided element B92 at the low-rigidity portion is weighted lowly to calculate the area of the contact surface.

[0078] Also, as the positional relationship between the contact surfaces, scoring is performed so that the contact surface direction of the divided element B91 at the high-rigidity portion has a low score and the divided element B92 at the low-rigidity portion has a high score to evaluate the contact state and estimate the rigidity of the divided elements.

[0079] According to Example 3, it is possible to improve the dimensional accuracy of a finished product, an intermediate product, etc. generated by machining the composite material. Also, even for a composite material in which the rigidity changes during machining of the divided elements, it is possible to suppress the occurrence of defects.

Description of Reference Numerals

[0080] 10: Machining path generation device 11: Processing unit 12: Storage unit 13: Input unit 14: Output unit 15: Communication unit 111: Information acquisition processing unit 112: Machining path generation unit 113: Machining path evaluation unit 114: Machining condition adjustment unit 115: Conversion unit 121: Workpiece material information 122: Tool information 123: Machining path information

Claims

1. A machining path generation device that generates a machining path for machining a workpiece, comprising: a communication unit that receives workpiece information of the workpiece and tool information of a tool for machining the workpiece; a processing unit connected to the communication unit; wherein the processing unit: generates a machining shape of a removal portion to be removed from the workpiece based on the workpiece information and the tool information received by the communication unit; divides the generated machining shape into a plurality of divided elements; generates a plurality of machining paths by combining machining orders for the plurality of divided elements; estimates the rigidity of the plurality of divided elements from the contact state between the divided elements and the workpiece; selects, based on the estimated rigidity of the divided elements, a machining path in which the rigidity of the divided element exceeds a threshold value and has the best score from the plurality of generated machining paths a machining path generation device.

2. The machining path generation device according to claim 1, wherein the processing unit estimates the rigidity of the divided element based on the area ratio of the contact area between each of the divided elements and the workpiece or other divided elements to the total surface area of the divided element. a machining path generation device.

3. The machining path generation device according to claim 2, wherein the processing unit estimates that the rigidity of the divided element is high when the area ratio is large, and estimates that the rigidity of the divided element is low when the area ratio is small. a machining path generation device.

4. The machining path generation device according to claim 3, wherein the processing unit estimates the rigidity of the divided element according to the number of types of normal directions of the contact surface of the divided element in addition to the area ratio. a machining path generation device.

5. The machining path generation device according to claim 4, wherein the processing unit estimates that the rigidity of the divided element is high when the number of types of normal directions of the contact surface of the divided element is large, and estimates that the rigidity of the divided element is low when the number of types of normal directions of the contact surface of the divided element is small. a machining path generation device.

6. The machining path generation device according to claim 3, wherein the processing unit determines a priority order of the machining paths based on at least one of machining efficiency, noise level, and energy consumption when machining the plurality of divided elements based on the workpiece information and the tool information, and estimates the rigidity of the divided element according to the priority order. a machining path generation device.

7. The machining path generation device according to claim 3, wherein the workpiece information received by the communication unit is information including the shape of the workpiece before machining and the material of the workpiece. The tool information received by the communication unit is information including the outer diameter of a cutting tool for a tool that processes a workpiece A machining path generation device.

8. In the machining path generation device according to claim 3, The preprocessing unit selects a tool for machining the workpiece based on the workpiece information and the tool information received by the communication unit, and divides the machining shape of the removal part removed from the workpiece into divided elements that can be removed by one movement of the selected tool. A machining path generation device.

9. In the machining path generation device according to claim 3, The processing unit calculates a weighted area ratio based on a material rigidity parameter corresponding to the material of the workpiece, and estimates the rigidity of the divided element based on the calculation result. A machining path generation device.

10. A machining path generation method for generating a machining path for machining a workpiece by a machining path generation device including a communication unit and a processing unit connected to the communication unit, wherein the communication unit receives workpiece information of the workpiece and tool information of a tool for machining the workpiece, and the processing unit generates a machining shape of a removal part removed from the workpiece based on the workpiece information and the tool information received by the communication unit, divides the generated machining shape into a plurality of divided elements, generates a plurality of machining paths by combining the machining orders for the plurality of divided elements, estimates the rigidity of the divided element based on the area ratio of the contact area between each of the divided elements and the workpiece or other divided elements to the total surface area of the divided element, and selects a machining path in which the rigidity of the divided element exceeds a threshold value and has the best score from the plurality of generated machining paths based on the estimated rigidity of the divided element. A machining path generation method.

11. In the machining path generation method according to claim 10, the processing unit estimates that the rigidity of the divided element is high when the area ratio is large, and estimates that the rigidity of the divided element is low when the area ratio is small. A machining path generation method.

12. In the machining path generation method according to claim 11, the processing unit calculates a weighted area ratio based on a material rigidity parameter corresponding to the material of the workpiece, and estimates the rigidity of the divided element based on the calculation result. A machining path generation method.

13. A workpiece production method for machining a workpiece by generating a machining path for machining the workpiece by a machining path generation device connected to an NC machine tool and including a communication unit and a processing unit connected to the communication unit, wherein the communication unit of the machining path generation device receives workpiece information of the workpiece and tool information of a tool for machining the workpiece, the processing unit of the machining path generation device, generates a machining shape of a removal portion to be removed from the workpiece based on the workpiece information and the tool information received by the communication unit, divides the generated machining shape into a plurality of divided elements, generates a plurality of machining paths by combining machining orders for the plurality of divided elements, estimates the rigidity of the divided element based on the area ratio of the contact area of each of the divided elements with the workpiece or other divided elements to the total surface area of the divided element, selects a machining path in which the rigidity of the divided element exceeds a threshold value and has the best score from the plurality of generated machining paths based on the estimated rigidity of the divided element, and outputs the selected machining path to the NC machine tool, and the NC machine tool machines the workpiece according to the machining path output from the machining path generation device to generate a workpiece. Workpiece production method.

Images