JP5890907B2 - Machining process determination method and machining process design apparatus - Google Patents

Description

  The present invention relates to a method for determining a machining process including a plurality of processes and a machining process design apparatus suitable for a CAM (computer-aided machining) system.

  In the machining production line composed of NC machines, the CAM is used to prepare the actual machining for the CAD model of the product to be produced. NC data that controls the operation of NC processing machines for each NC processing machine after creating a tool path, which is tool trajectory information, by setting a processing area that specifies the CAD model processing range using conditions, tools and processing conditions Need to create. The NC data created by CAM is transferred to the NC machine and actual machining is performed.

  When performing process design in the CAM, a high material removal rate is required for roughing, and a high surface quality is required for finishing. In general, the machining process is designed by multiple processes of roughing and finishing. However, depending on the shape of the workpiece, the maximum uncut amount due to roughing may exceed the machining allowance of the tool for finishing. The risk of chipping of the machining tool, deterioration of the finished surface, etc. increases. In order to avoid such problems, process design is often performed between the roughing process and the finishing process to insert the medium roughing process with a margin, but it is optimal for improving the productivity of machining. There is a need for a method for determining the correct processing steps.

  As a background art of this technical field, there is Patent Document 1. In this publication, “in the roughing method by the contour line processing method, the processing surface is classified for each inclination angle of the finished surface of the workpiece, and the maximum remaining amount of cutting by the tool used for each classified surface is calculated, When the calculated maximum remaining amount of machining exceeds the allowable value, a re-machining position is set for that portion ”(see summary).

  Moreover, there exists patent document 2. FIG. This gazette states, “Select process candidates from the plurality of process candidates in descending order of machining capability, find the maximum machining area that can be machined by the process candidates from the shape before machining and the shape after machining. The difference between the machining area and the shape after machining is obtained, and selection of process candidates is repeated until the difference falls below an allowable value.The selected process candidates are arranged, and the last selected process candidate is the final process. For each process order candidate, the effective machining time is obtained from the machining capacity, machining amount and load time of each process, and the total effective machining time of each process is summed to obtain the total effective machining time. The process sequence candidate that has the shortest effective machining time is determined as the machining process ".

  Moreover, there exists patent document 3. FIG. In this publication, “To read the three-dimensional material shape data M3 and the three-dimensional product shape data M1 from the three-dimensional CAD device H1 and generate the three-dimensional product shape data M1 from the three-dimensional material shape data M3 through a plurality of steps. The machining knowledge database D1 storing the finishing cost 46 and threshold values necessary for determining the machining conditions, the process candidate database D2 storing various tool information, and the three-dimensional product shape data The finishing allowance 46 is built up in M1, and the three-dimensional shape data M2 is created. Using this as a processing target, the order of processing steps for increasing processing accuracy and processing efficiency from a plurality of steps using various tool information. The process design module E1 to be determined is provided. "

JP 2003-108207 A Japanese Patent No. 4748049 JP 2009-274160 A

  However, the machining process design method described in Patent Document 1 does not consider a machining process consisting of a plurality of processes, and the scallop height (the scallop height is used as an index of surface accuracy) for uncut parts. 8A, an uncut portion is formed between adjacent tool paths of the processing tool, but is defined as the maximum height measured in the direction perpendicular to the final finished surface that is the product shape. In the case of FIG. 8 (b) where is represented by a slope, the scallop height is measured in the direction perpendicular to the slope.

  In addition, the surface accuracy other than the final surface is not considered in the device described in Patent Document 2, and surface accuracy between processes is not considered. For this reason, there is a problem in that the post-process shape after the pre-process affects the post-process, and it is not possible to eliminate concerns about problems in actual processing such as abnormal wear of the tool.

  In addition, according to the processing knowledge described in Patent Document 3, the final surface accuracy is uniquely defined as a finishing allowance, and the necessity of the previous process of a specific feature such as drilling is made into a database without considering the surface accuracy before the finishing process. There is a problem that it is determined and is not compatible with three-dimensional free-form surface processing.

  Accordingly, an object of the present invention is to provide a method for determining the process order of a plurality of processes based on the surface accuracy of each process in the three-dimensional shape processing.

  For example, the machining process in cutting generally increases the machining efficiency by using a large-diameter tool, but due to the large size of the tool, uncut parts are generated due to interference and restrictions on the tool shape. That is, there are many cases where the required surface accuracy cannot be satisfied with only one tool and process, and it is necessary to combine a plurality of processes to satisfy the surface accuracy. The combination of the steps and the determination of the order are often used as a template for each product or part to be processed in actual operation due to the complexity of the determination. However, the use of a template cannot optimize the machining process for each detailed design shape. An object of the present invention is to provide a method for determining a combination of processes having high accuracy and high efficiency with respect to a trade-off between accuracy and efficiency (productivity) and determining the order thereof.

  The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

In order to solve the above problems, in the present invention, in a method for determining a machining process consisting of a plurality of processes for processing a shape of a material into a design shape, at least a processing machine, a tool, a machining specification, and a machining method. In addition to each data item, create a process candidate data table that has a data item of surface accuracy before processing of the surface to be cut (required surface accuracy before processing), and create a machining area model from the process design target product CAD model and material CAD model The process area model is selected from the process candidate data table, and an initial process candidate capable of machining with high machining efficiency is selected from the process candidate data table, and tool path data for machining the machining area model with the selected process candidate is created. , the tool path data, and using the geometric element data of the tool and the workpiece, calculates a post-processing surface accuracy, the post-machining surface accuracy meet the final requirements surface accuracy Whether determined, if not satisfied, the process candidate with unprocessed request surface accuracy satisfying the post-machining surface accuracy from the process candidate data table is selected as the next step, the processing region model by said next step The process up to the step of determining whether or not the post-machining surface accuracy satisfies the final required surface accuracy is repeated by a simulation of machining the uncut region.

In order to solve the above problems, in the present invention, at least a process name, a processing machine, a tool, a processing specification, a processing method, a storage unit that stores a process candidate storage table having data items of required surface accuracy before processing, A calculation unit, an input unit, an output unit, and a communication unit, wherein the calculation unit extracts a region to be removed by cutting from a difference between a material shape and a final shape, and the storage unit The machining process design unit that determines the combination and order of processes from the process candidate data stored in the table and creates a machining process design plan, product CAD model data, material CAD model data, machining area model data, and process candidate data using a tool path data 3D CAM was prepared in accordance with the post-machining surface accuracy calculation unit that calculates a post-process surface accuracy for each process from the geometric elements of the tool and the work material, after said machining Compares the accuracy, the final request surface accuracy is design requirements, after processing surface accuracy to determine whether it satisfies the last request surface precision, and a post-process surface accuracy calculated by the post-process surface accuracy computing unit, wherein Comparing with the required surface accuracy before processing of the process candidate storage table stored in the storage unit, the surface accuracy comparison processing unit that selects the process candidate satisfying the required surface accuracy before processing, and created by the processing process design unit A machining process design apparatus having a machining time calculation unit for calculating a machining time with respect to the process design plan is configured.

According to the present invention, it is possible to provide a method for determining a process order of a plurality of processes based on surface accuracy of each process in three-dimensional shape processing.
For example, the processing time is reduced by determining a process combination having a short total processing time based on the surface accuracy of the surface to be cut. In addition, preparation man-hours are reduced by automating process design by searching for process combinations. In addition, safety is improved by taking into consideration machining defects by considering surface accuracy between processes.
Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

1 is a configuration diagram of a machining process design apparatus that implements a machining process design method according to an embodiment of the present invention. (A)-(c) is drawing for demonstrating the relationship of the required surface accuracy before a process, surface accuracy after a process, and final required surface accuracy considered in the process design which paid its attention to processing efficiency and surface accuracy. It is an example of a process candidate storage table configuration according to an embodiment of the present invention. It is a figure which shows the structural example of a processing machine data table. It is a flowchart which shows the outline | summary of the manufacturing process design method which concerns on one embodiment of this invention. It is a flowchart which shows the method of dividing | segmenting a process area based on the post-process surface accuracy which concerns on one embodiment of this invention. It is a flowchart which shows the method of searching for the possible combination by the manufacturing process design method which concerns on one embodiment of this invention. It is a figure for demonstrating the definition of scallop height. It is a figure which shows an example of the CAM setting screen which concerns on one embodiment of this invention. It is a figure which shows the example which displays the error of the process sequence of the machining process list screen of the CAM setting screen which concerns on one embodiment of this invention. It is a figure which shows the example which changed the setting method of the surface accuracy after a process of the process list screen of the CAM setting screen which concerns on one embodiment of this invention.

(1) Summary of the Invention First, the summary of the present invention will be described.
As described in the problem to be solved by the invention, in actual machining, there are many cases where the required surface accuracy cannot be satisfied only with a process with high machining efficiency, and machining is performed by combining a plurality of processes with different machining efficiency. Is done. Determining the combination and order of the processes is referred to as process design (sometimes referred to as machining process design, machining strategy planning, etc.), and the determined combination and order are referred to as process design proposal.

  2A, 2B, and 2C are graphs in which the horizontal axis represents machining efficiency and the vertical axis represents surface accuracy. Hereinafter, items to be considered in the process design will be described using this graph.

  In FIG. 2 (a), in a rough process with high machining efficiency (the foremost machining process set with the highest machining efficiency when machining the workpiece surface in a plurality of processes) 201, surface accuracy after machining is shown. Is rougher than the final surface accuracy (final required surface accuracy) required in the design, and an additional process is required. In order to satisfy the final required surface accuracy, a finishing process (final processing step set with an emphasis on surface accuracy so as to satisfy the final required surface accuracy when the surface to be processed is processed in multiple steps) 203 is required. However, in order to perform the finishing process 203, it is necessary that the post-process surface accuracy of the preceding process satisfies the required surface accuracy of the finishing process 203 before processing.

  Here, the required surface accuracy before processing is the surface accuracy before processing of the surface to be cut required for carrying out a certain process. For example, if the finishing process is performed with a rough surface, the finishing tool will be lost. This is a condition that is set in consideration of such a situation.

  For example, FIG. 2 (a) shows that the post-machining surface accuracy, which is the result of machining by the large roughing process 201, does not satisfy the pre-machining required surface accuracy of the finishing step 203. For this reason, FIG. As shown in b), between the large roughing step 201 and the finishing step 203, the intermediate roughing step (the surface accuracy of the uncut surface by the large roughing step satisfies the required surface accuracy before processing, and the required surface accuracy before finishing in the finishing step. The process design plan is completed by adding a processing step 202 that can be processed with finer surface accuracy.

  As shown in FIG. 2 (a), it is clearly shown that there is a possibility that a machining defect may occur only by the combination of the rough roughing process 201 and the finishing process 203, and as shown in FIG. The addition of the intermediate rough process 202 is a necessary consideration in the process design.

Also, even in the same process, depending on the machining area, the final required surface accuracy may be satisfied even in a process with high machining efficiency, as shown in Fig. 2 (c), due to the difference in geometric contact between the tool and the work material. . Therefore, by calculating the post-machining surface accuracy before machining, eliminating redundant additional steps has a great effect of reducing machining time in process design.
In one embodiment, the present invention provides a method for designing a machining process by paying attention to, for example, post-machining surface accuracy and pre-machining required surface accuracy.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof will be omitted.
(2) Configuration of Machining Process Design Apparatus for Implementing Machining Process Design Method FIG. 1 shows a configuration diagram of a machining process design apparatus 100 that implements a machining process design method according to an embodiment of the present invention.

In FIG. 1, the machining process design apparatus 100 includes a calculation unit 101, a storage unit 102, an input unit 103, an output unit 104, and a communication unit 105. The machining process design apparatus 100 is connected to a three-dimensional CAM 130, an NC machine tool 140, a three-dimensional CAD 150, and an NC simulator 160 via a communication unit 105 and a network 170.
Note that the machining process design apparatus 100 may be configured as one function of the three-dimensional CAM 130 in the same apparatus. Further, the input unit 103 and the output unit 104 are not held as independent components in the machining process design device 100, and for example, an input / output device held by the NC machine tool 140 may be used.

The input unit 103 is, for example, a keyboard or a mouse, the output unit 104 is, for example, a display or a printer, the arithmetic unit 101 is, for example, a processor such as a CPU, and the storage unit 220 is, for example, an HDD or a semiconductor memory.
The input unit 103 receives input of user instructions, and the output unit 104 displays and prints the processing results of the computer system.

  The three-dimensional CAD 150 creates a material shape (material CAD model) and a final shape (product CAD model) of a product to be processed as three-dimensional shape data. In addition to the material shape and the final shape, an intermediate shape for processing may be created as the three-dimensional data.

  The 3D CAM 130 determines a machining area, sets machining conditions, selects a tool, and creates a machining path for the 3D shape data created by the 3D CAD 150 or the 3D shape data input from the outside. An NC program is created from the created machining path. The processing up to the creation of the machining path can be performed by exchanging data between the three-dimensional CAM 130, the calculation unit 101 of the machining process design apparatus 100, and the storage unit 102. In addition, data exchange with the NC simulator 160 may be added to the processing.

  The NC simulator 160 loads the NC program created by the three-dimensional CAM 130 or the NC program stored in the storage unit 102 of the machining process design device 100, executes a machining simulation, and answers the result.

  The calculation unit 101 executes a program stored in the storage unit 102 and the like, thereby processing region calculation unit 110, processing step design unit 111, post-processing surface accuracy calculation unit 112, surface accuracy comparison processing unit 113, processing It functions as a time calculation unit 114 and a machining process surface accuracy check unit 115.

  The processing region calculation unit 110 extracts a region to be removed by cutting from the difference between the material shape and the final shape. Here, the material shape and the final shape may be replaced with an intermediate shape for processing.

  The machining process design unit 111 determines a combination and order of processes from the process candidate data held in the storage unit 102 and creates a process design plan. The processing is performed based on the processing results in the post-processing surface accuracy calculation unit 112, the surface accuracy comparison processing unit 113, and the processing time calculation unit 114. Details of the processing of the machining process design unit will be described later using the flowcharts of FIGS.

The post-machining surface accuracy calculation unit 112 uses the tool path data created by the three-dimensional CAM in accordance with the product CAD model data, the material CAD model data, the machining area model data, and the process candidate data, and uses a tool and a work material for each process. The surface accuracy after processing is calculated from the geometric elements. Here, the geometric element includes at least the tool cutting edge R, the shaft cut Ap, and the inclination angle θ between the tool and the work material. In addition, the post-machining surface accuracy calculation unit 112 can request the NC simulator 160 to execute a machining simulation, and calculate post-machining surface accuracy based on the result.
The post-process surface accuracy calculation unit 112 calculates at least the scallop height as an index of the post-process surface accuracy. As shown in Fig. 8 (a), the scallop height is defined as the maximum height measured in the direction perpendicular to the final finished surface, which is the product shape, although there is an uncut portion between adjacent tool paths of the machining tool. The In the case of FIG. 8B where the final shape 800 is represented by a slope, the scallop height is measured in the direction perpendicular to the slope. As another index of scallop height, for example, surface roughness (Ra: centerline average roughness, Rmax: maximum height, Rz: ten-point average roughness, etc.) described in JIS, etc. may be calculated. Good.

  The surface accuracy comparison processing unit 113 compares the post-processing surface accuracy calculated by the post-processing surface accuracy calculation unit 112 with the final required surface accuracy that is a design requirement, and whether the post-processing surface accuracy satisfies the final required surface accuracy. Determine. Further, the processed surface accuracy calculated by the processed surface accuracy calculation unit 112 is compared with the required surface accuracy before processing stored in the storage unit 102, and process candidates that satisfy the required surface accuracy before processing are selected.

  The machining time calculation unit 114 calculates a machining time for the process design plan created by the machining process design unit 111. Here, the machining time can be calculated from the length of the machining path created by the three-dimensional CAM 130 and the feed speed, for example. Further, by using the NC simulator 160, it is possible to calculate a machining time considering the maximum speed, acceleration / deceleration, tool change time, etc. of each axis of the machine tool.

As described above, the calculation unit 101 in this embodiment defines the required surface accuracy before processing in each step, the surface accuracy after processing in each step, and the final required surface accuracy that is a design requirement as the surface accuracy. Has been.
(3) Configuration of Storage Unit The storage unit 102 includes a process candidate data storage area 120, a processing machine data storage area 121, a product CAD model storage area 122, a material CAD model storage area 123, a machining area model storage area 124, and an NC program storage. An area 125 and a machining process design plan storage area 126 are included. The data in each storage area may be shared with the data in the storage unit of the three-dimensional CAM 130. In that case, the data may be stored in the storage unit of the three-dimensional CAM 130.

The process candidate data storage area 120 stores a process candidate storage table 301 shown in FIG. The process candidate storage table 301 has, for example, a process name 311, a processing machine 312, a tool 313, a processing specification 314, a processing method 315, and a required surface accuracy 316 before processing as table components. In addition to this, for example, the required surface accuracy after processing (including the one calculated by the post-processing surface accuracy calculation unit 112 such as the scallop height), the tool entry / exit method (engage, retract), etc. A setting item included in a typical CAM may be included as a component.
Each data record specified by the process name 311 is data representing one process candidate, and is registered in advance as a process candidate assumed in the table.

The processing machine 312 holds a name and identification ID that specify a processing machine on which the process candidate specified by the process name 311 is implemented.
The tool 313 holds, for example, information such as a tool material type (carbide, high speed, ceramic, etc.), a tool shape type (bull nose, ball end, total shape, etc.), a tool diameter, a tool edge R, and the number of teeth.
Even with the same tool, a plurality of process plans with different processing specifications and processing methods may be held as candidates.

  The machining specification 314 holds information such as a cutting speed V (m / min) and a single blade feed fz (mm / blade). You may hold | maintain the condition values used when instruct | indicating to a machine tool, such as spindle speed S (rpm) and feed speed F (mm / min). The material type of the target work material may be added as a table constituent element, and the machining specifications may be held for each material type.

  The machining method 315 includes, for example, a machining method based on the operation of the tool (contour line machining, part-dependent machining, trochoidal machining, etc.), a contact amount between the tool and the work material (axial cutting amount (ap), diameter cutting amount (ae). Etc.) is retained. The contact amount between the tool and the work material may not be defined, and for example, the post-machined surface accuracy such as the scallop height may be set as a condition, and the cutting depth of the tool that satisfies the setting condition may be set by the three-dimensional CAM 130.

The required surface accuracy 316 before processing is the surface accuracy before processing of the surface to be cut that is required for carrying out a certain process. For example, the scallop height, part stock (constant thickness from the bottom surface of the scallop to the processing surface), Defined by maximum cutting height, maximum unit removal volume, etc. Further, for example, the surface roughness (Ra: centerline average roughness, Rmax: maximum height, Rz: ten-point average roughness, etc.) described in JIS may be used.
Depending on the process candidate tool (for example, a tool that is resistant to initial cracks, a roughing tool with a significantly high cutting depth, etc.) and processing specifications (such as low specifications that presuppose machining of parts with poor surface accuracy) There may be a process candidate that does not maintain the required surface accuracy before processing.

  By holding the required surface accuracy 316 before processing as a constituent element of the process candidate storage table 301, it is possible to generate a process order plan that satisfies the process prerequisites in the process process design including a plurality of processes. The required surface accuracy before processing of the process candidate data storage area is a feature of the present invention.

The processing machine data storage area 121 stores device information of all the processing machines in the machining shop. For example, in this embodiment, a processing machine data table 401 as shown in FIG. 4 is stored.
As shown in the figure, a processing machine data table 401 includes a processing machine number column 411 that is identification information for specifying a processing machine, a processing machine column 412 for storing information for specifying the processing machine name of the processing machine, and the axis of the processing machine. An axis configuration column 413 for storing information for specifying the configuration, a stroke column 414 for storing information for specifying the stroke of each axis of the processing machine, and a setup time column 415 for storing an average time for changing the processing machine Have

The product CAD model storage area 122 receives and stores product CAD model data representing the final machining shape for each product created by the three-dimensional CAD device 150 via the network 170 and the communication unit 105.
Product CAD model data is stored in, for example, the DXF file format. The face model is defined in the element definition section (ENTITIES) as each graphic element constituting the drawing, and the solid model is stored in the block definition section (BLOCKS). It is defined as a block graphic element. In this embodiment, the CAD file format is not particularly limited.
In this embodiment, final required surface accuracy data is added to the product CAD model as the surface accuracy of the shape of the product. As this data, there are a case where data created by the three-dimensional CAD device 150 is adopted and a case where final required surface accuracy data is added when product CAD model data is registered in the machining process design device 100.

  The material CAD model storage area 123 stores three-dimensional CAD data representing the material shape of each product. Stores data in either face model, solid model, or both formats. The three-dimensional CAD data created in the three-dimensional CAD device 150 is received via the communication unit and stored. The file format of the material CAD model storage area 123 is also stored in the same file format as that of the product CAD model storage area 122 described above.

  The machining area model storage area 124 stores a machining area model created by the machining area calculation unit 110 extracting a machining area to be removed by cutting from the difference between the material CAD model and the product CAD model. Alternatively, the machining area model data created by the three-dimensional CAM 130 is received and stored. The file format of the machining area model storage area is also stored in the same file format as that of the product CAD model storage area 122 described above.

  In the NC program storage area 125, an NC program created by the three-dimensional CAM 130 and used as an input of the NC machine tool 140 is held in association with the process design plan.

The machining process design plan storage area 126 stores the process design plan data created by the machining process design unit 111. As shown in the machining process list screen 903 in FIG. 9, the process design plan data includes a process order number field 911, a process name field 912 for specifying a process name, a tool field 913 for storing information on a tool to be used, Machining specification column 914 for storing information of machining parameters to be used, pre-processing required surface accuracy column 915 for reading and recording the pre-processing required surface accuracy from the process candidate storage table 301, and processing calculated by the post-processing surface accuracy calculation unit 112. Record the back accuracy.
(4) Outline of machining process design method Next, an outline of a machining process design method according to an embodiment of the present invention will be described with reference to FIG. FIG. 5 is a flowchart showing an outline of a machining process design method executed by the machining process design unit 111 of the machining process design apparatus 100.

  First, in step S501, a process designer receives an input designating a process design target product from the input unit 103, and stores product CAD model data, material CAD model data, and machining area model data stored in the storage unit 102. read out. When the corresponding data is not registered in the storage unit 102, the data stored in the storage unit of the three-dimensional CAM 130 is read out.

  Here, the machining area model data is obtained by instructing the input unit 103 or the three-dimensional CAM 130 to create a machining area model, accepting the created machining area model data, and storing the machining area model data in the machining area model storage area 124, for example. is there. Alternatively, the machining area calculated by the machining area calculation unit 110 based on the shape data created by the three-dimensional CAD 150 is stored in the machining area model storage area 124.

  In step S <b> 502, the machining efficiency is the highest among the process candidates stored in the process candidate data storage area 120 of the storage unit 102 for the product CAD model data, the material CAD model data, and the machining area model data to be designed. A process having a high value is selected as the initial process.

  In step S503, generation of a tool path for processing according to each data of a processing machine, a tool, a processing specification, and a processing method registered in the data record of the process candidate selected in the previous step is generated in the three-dimensional CAM 130. The tool path data generated by the three-dimensional CAM is input via the network 170 and the communication unit 105.

  In step S504, the surface accuracy after processing the processing region model using the process candidate data selected in step S502 or step S507 and the tool path data input in the previous step is processed by the post-processing surface accuracy calculation unit 112. After processing surface accuracy) α is calculated.

  In step S505, it is determined by the processing of the surface accuracy comparison processing unit 113 whether the post-processing surface accuracy α calculated in the previous step S504 satisfies the final required surface accuracy (product CAD model) of the product. If the final required surface accuracy is satisfied, the process design is terminated. If the final required surface accuracy is not satisfied, the process proceeds to step S506.

  In step S506, since the next process is necessary, an instruction to correct the tool path of the previous process created in step S503 is sent to the three-dimensional CAM 130 so as to leave a machining allowance for the next process. Enter the toolpath data. If it is determined that the tool path does not need to be corrected, this step is omitted.

In step S507, process candidates that satisfy the constraint that the required surface accuracy before processing is higher than the post-processing surface accuracy α calculated in step S504 are selected from the process candidates stored in the process candidate data storage area 120 of the storage unit 102. Then, a process having a high machining efficiency is selected for the remaining machining area cut by the tool path of the previous process from the target machining area model.
For the selection of the process in step S507, for example, not only a process having the highest processing efficiency but also a method of selecting at random from processes having a higher processing efficiency than the average may be used.
In addition, the selection of the process in step S507 may use an evaluation index such as a process with high post-processing surface accuracy instead of a process with high processing efficiency.

After the process is selected in step S507, the process returns to step S503, the above process is repeated until the condition of step S505 is satisfied, and the process order is determined.
According to the flowchart shown in FIG. 5, it is possible to determine a process order plan that does not cause a problem in processing in surface accuracy before and after the process in a processing process including a plurality of processes.
(5) Machining process design method for dividing machining region based on post-machining surface accuracy Next, a method for dividing a machining region based on post-machining surface accuracy according to an embodiment of the present invention will be described with reference to FIG. FIG. 6 is a flowchart showing a method of dividing the machining area based on the post-machining surface accuracy executed by the machining process design unit 111.

  The flowchart of FIG. 6 is a flowchart in which new processing is added between steps with respect to the flowchart of FIG. Steps S501 to S507 in FIG. 6 have the same functions as the processes denoted by the same reference numerals shown in FIG.

  In step S601, when the value of the post-machining surface accuracy α calculated in step S504 has a variation in the machining area, an arbitrary threshold (for example, in the process candidate data storage area 120 of the storage unit 102) is based on the value of α. The machining area is divided for each range of the required surface accuracy before machining set for the stored process candidates. After the division, the maximum value of α within the threshold range (that is, the value of the portion having the worst surface accuracy) is stored in the machining region model storage area 124 together with the divided machining regions as α of the divided machining regions.

  In step S602, one machining area divided in step S601 is selected, and the process proceeds to step S505.

  In step S505, it is determined by the processing of the surface accuracy comparison processing unit 113 whether the post-processing surface accuracy α calculated in step S504 satisfies the final required surface accuracy of the product. If the final required surface accuracy is not satisfied, the process proceeds to step S506 as in the process of FIG. If the final required surface accuracy is satisfied, the process design of the divided machining area is completed, and the process proceeds to step S603.

  In step S603, it is determined whether or not the process design process has been completed in all the divided machining areas among the machining areas divided in step S601. If the processing is finished, the process design is finished. If there is a divided processing area that has not been processed, the process proceeds to step S604.

  In step S604, one divided machining area for which process design has not been completed is selected from the machining areas divided in step S601, and the process proceeds to step S505.

According to the flowchart shown in FIG. 6, when there is a large variation in the processed surface accuracy α in the initially set processing region, an appropriate process candidate is determined for each divided processing region by dividing the processed region based on the processed surface accuracy. It is possible to select and perform process design.
(6) Method for Searching for Possible Combinations in Process Order Determination Processing Next, referring to FIG. 7, a method for searching for possible combinations from among process candidates in the machining process design method according to one embodiment of the present invention. explain. FIG. 7 is a flowchart showing a method for searching for possible combinations by the machining process design method according to the embodiment of the present invention.

First, in step S701, the designer receives an input designating a design target product from the input unit 103, and reads product CAD model data, material CAD model data, and machining area model data stored in the storage unit 102. When the corresponding data is not registered in the storage unit 102, the data stored in the storage unit of the three-dimensional CAM 130 is read out.
Here, the machining area model data is obtained by instructing the input unit 103 or the three-dimensional CAM 130 to create a machining area model, accepting the created machining area model data, and storing the machining area model data in the machining area model storage area 124, for example. is there. Alternatively, the machining area calculated by the machining area calculation unit 110 based on the shape data created by the three-dimensional CAD 150 is stored in the machining area model storage area 124.

  In step S <b> 702, an initial process is selected from the process candidates stored in the process candidate data storage area 120 of the storage unit 102 for the product CAD model data, the material CAD model data, and the machining area model data to be designed. Select one selectable process. Here, the process that can be selected as the initial process is, for example, a process that uses a tool that is resistant to initial fractures that does not have the required surface accuracy before processing, and the processing conditions are set lower than usual so that it can be used as the initial process. Process.

  In step S703, process design is performed using the process selected in step S702 as an initial process. The process design is executed by replacing step S502 with step S712 in FIG. 7 in steps S502 to S507 in the flowchart of FIG. Alternatively, in steps S502 to S604 of the flowchart of FIG. 6, step S502 may be replaced with step S712 of FIG.

  In step S704, the processing time of the process design plan created in step S703 is estimated by the processing of the processing time calculation unit 114.

  In step S705, it is determined whether there is a process that can be selected as an initial process among the process candidates stored in the process candidate data storage area 120 of the storage unit 102. If a process candidate remains, the process returns to step S702, and one of the remaining process candidates is selected, and the process is continued. If no process candidate remains, the process proceeds to step S706.

  In step S706, the process design plan that minimizes the machining time is selected from the process design plans created by the processing up to the previous step.

According to the flowchart shown in FIG. 7, in a machining process consisting of a plurality of processes, it is possible to determine a process order plan that does not cause a malfunction in surface accuracy before and after the process and a combination of process candidates that minimizes the machining time. .
(7) Screen Display Example Next, screen display examples according to an embodiment of the present invention will be described with reference to FIGS. FIG. 9 is a diagram illustrating an example of a CAM setting screen 901 according to an embodiment of the present invention, and FIG. 10 displays an error in the process order on the machining process list screen of the CAM setting screen according to an embodiment of the present invention. FIG. 11 is a diagram illustrating an example, and FIG. 11 is a diagram illustrating an example in which a method for setting the post-machining surface accuracy on the machining process list screen of the CAM setting screen according to the embodiment of the present invention is changed.

  As shown in FIG. 9, the CAM setting screen 901 includes, for example, a model display screen 902, a machining process list screen 903, and the like. The CAM setting screen 901 is a screen for providing a man-machine interface when the process designer performs the process design using the machining process design apparatus 100, and includes an output unit 104 (the machining process design apparatus 100 and the three-dimensional CAM 130. Is mounted on the same device, it is displayed on the output unit of a three-dimensional CAM). The process design device 100 displays the product CAD model, the material CAD model, and the machining area model corresponding to the input designated by the process designer from the input unit 103 as the design target product, or the machining area is displayed on the 3D CAM 130. There is a model display screen 902 having a function of instructing determination and generation of a tool path, receiving the result, and displaying the result on the screen to support the confirmation of the process designer. In addition, there is a machining process list screen 903 that displays a machining process design plan created by the machining process design apparatus 100 to a process designer and supports confirmation.

  The model display screen 902 displays a processing area, a processing path, and the like in each process as a two-dimensional or three-dimensional model. For example, the material shape, design shape, intermediate shape, tool movement trajectory, tool axis inclination, and the like are displayed. In order to define a machining area on the product CAD model, the machining area can be selected using a cursor 904 or the like. Further, in conjunction with the machining process list screen 903, the machining area and machining path corresponding to the machining process selected on the machining process list screen 903 may be explicitly shown by highlighting by color change or blinking display.

  The machining process list screen 903 displays a machining process design plan as a list of machining processes. The components of the machining process list include, for example, a process order 911, a process name 912, a tool 913, a machining specification 914, a required surface accuracy 915 before processing, a post-processing surface accuracy 916, and the like. In addition, you may have the component of the process candidate storage table 301, etc. as a component. Further, when the machining specification data is stored in association with the tool in the process candidate storage table 301 of the storage unit 102, the machining specification 914 or the like may be omitted.

  Further, the post-machining surface accuracy 916 is accepted as a setting of the three-dimensional CAM 130 in process design, for example, not a value (calculated surface accuracy after machining) calculated by the post-machining surface accuracy calculation unit 112 of the machining process design device 100 or the like. The input value (required surface accuracy after processing) may be displayed. Further, both the calculated surface accuracy after processing and the required surface accuracy after processing may be displayed.

  If the process designer determines that the machining process design plan displayed on the machining process list screen 903 is acceptable, the process designer instructs the three-dimensional CAM 130 to create an NC program, and the machining process design apparatus 100 is created. The NC program is received and stored in the NC program storage area 125 in association with the machining process design plan. The stored NC program is sent to the NC simulator 160, and the quality can be confirmed by machining simulation. The simulation result is displayed on the model display screen 902. The NC program whose quality has been confirmed is downloaded to the NC machine tool 140 in the machine shop and manufactured.

  On the CAM setting screen, it is known from commercially available CAM software that the setting of the required surface accuracy after processing in each step is accepted, but the setting of the required surface accuracy 915 before processing is accepted according to the present embodiment. This is a remarkable feature in the CAM setting screen 901.

  FIG. 10 shows an example of a different form of the machining process list screen 903. As a component of the machining process list, there is an item of a surface accuracy check 1001, for example, a check result such as OK or NG is displayed. In the example of FIG. 10, the post-process surface accuracy of the process 1011 is 1.8, and the pre-process required surface accuracy of the process 1012 of the next process is set to 1.6. For this reason, the post-process accuracy of the process 1011 does not satisfy the required pre-process accuracy of the process 1012, and a process failure may occur in the process 1012. In the surface accuracy check 1001 of the present embodiment performed by the processing process surface accuracy check unit 115 for such a process sequence, NG is displayed in the step 1012 and a request for correction of the step 1012 or the process before and after the step 1012 is explicitly indicated. Can be shown.

  When the machining process design method described in FIGS. 5 to 7 is used, a process design plan that does not satisfy the surface accuracy as shown in FIG. 10 is not generated, but the process design is performed so as to be performed by a general CAM. In the case where each process is created, or when the process order and process candidates are partially changed, the effect of preventing machining defects can be obtained by the evaluation by the surface accuracy check 1001 according to this embodiment and the result display. .

  FIG. 11 shows an example of a different form of the machining process list screen 903. In this example, the post-machined surface accuracy 1101 that is a component of the machining process list is set so that the post-machined surface accuracy can be set in a plurality of processes instead of each process. For example, it is possible to omit the subsequent steps 1112 and 1113 in the region satisfying the post-processing accuracy 0.05 in Step 1111.

  In addition, this invention is not limited to above-described embodiment, Various modifications are included. For example, the above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to one having all the configurations described.

  Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. . In addition, it is possible to add, delete, and replace other configurations for a part of the configuration of the embodiment.

  Each of the above-described configurations, functions, processing units, processing means, and the like may be realized by hardware by designing a part or all of them with, for example, an integrated circuit. Each of the above-described configurations, functions, and the like may be realized by software by interpreting and executing a program that realizes each function by the processor. Information such as programs, tables, and files for realizing each function can be stored in a memory, a hard disk, a recording device such as an SSD (Solid State Drive), or a recording medium such as an IC card, an SD card, or a DVD.

  Further, the control lines and information lines indicate what is considered necessary for the explanation, and not all the control lines and information lines on the product are necessarily shown. Actually, it may be considered that almost all the components are connected to each other.

DESCRIPTION OF SYMBOLS 100 Machining process design apparatus 101 Operation part 102 Memory | storage part 103 Input part 104 Output part 105 Communication part 110 Machining area calculation part 111 Machining process design part 112 Post-process surface accuracy calculation part 113 Surface accuracy comparison process part 114 Processing time calculation part 115 Processing process Surface accuracy check unit 120 Process candidate data storage area 121 Machine data storage area 122 Product CAD model storage area 123 Material CAD model storage area 124 Processing area model storage area 125 NC program storage area 126 Machining process design plan storage area 130 3D CAM
140 NC machine tool 150 3D CAD
160 NC Simulator 201 Large Rough Process 202 Medium Rough Process 203 Finishing Process 301 Process Candidate Storage Table 311 Process Name 312 Processing Machine 313 Tool 314 Processing Specifications 315 Processing Method 316 Required Surface Accuracy 401 Before Processing Machine Data Table 411 Processing Machine Number Column 412 Machining machine name column 413 Axis configuration column 414 Stroke column 415 Setup time column 800 Final shape 901 CAM setting screen 902 Model display screen 903 Machining process list screen 904 Cursor 1001 for defining machining area Surface accuracy check column 1011, 1012 Step 1101 Processed Surface Accuracy Fields 1111 to 1113

Claims (9)

In a method for determining a machining process consisting of a plurality of processes for processing a shape of a material into a design shape,
In addition to at least the data items of the processing machine, tool, processing specifications, processing method, create a process candidate data table having data items of surface accuracy before processing of the surface to be cut (required surface accuracy before processing),
Create a machining area model from the CAD model of the process design target product and the material CAD model,
From the process candidate data table, select an initial process candidate capable of machining the machining area model with high machining efficiency,
Create tool path data to process the processing area model with the selected process candidate,
Using the tool path data and geometric element data of the tool and the work material, the post-machining surface accuracy is calculated,
Determining whether the post-machining surface accuracy satisfies the final required surface accuracy;
If not, select a process candidate having the required surface accuracy before processing that satisfies the post- processing surface accuracy as a next process from the process candidate data table,
By the simulation that processes the uncut region of the processing region model in the next step, the process is repeated until the step of determining whether the post-processing surface accuracy satisfies the final required surface accuracy,
A method for determining a machining process characterized by the above. The method for determining a machining process according to claim 1,
Shortening the total machining time by selecting a plurality of candidate process candidates having the required pre-machining surface accuracy that satisfies the post-machining surface accuracy from the process candidate data table and selecting a process with a high machining efficiency from these process candidates. A method for determining a machining process, comprising: determining a machining process. The method for determining a machining process according to claim 1,
In the processing region, when the post-processing surface accuracy varies, the processing region is divided based on the post-processing surface accuracy, and a process candidate is selected from the process candidate data table for each of the divided processing regions. Method of determining the process. The method for determining a machining process according to claim 1,
For all initial process candidates retrieved from the process candidate data table capable of processing the processing area model, each process candidate is used as an initial process, and the processing area model is processed until the post-processing surface accuracy satisfies the final required surface accuracy. Design the process,
Calculate the machining time for the designed machining process,
A method for determining a machining process, comprising: selecting a machining process design plan that minimizes the machining time of the machining process for each of all the initial process candidates. In the method for determining a machining process according to any one of claims 1 to 4,
Surface accuracy adopted as an index of required surface accuracy before processing includes scallop height, part stock, maximum cutting height, maximum unit removal volume, and surface roughness described in JIS (Ra: centerline average roughness, Rmax : Maximum height, Rz: Ten-point average roughness). A storage unit for storing a process candidate storage table having data items of at least a process name, a processing machine, a tool, a processing specification, a processing method, and a required surface accuracy before processing;
A calculation unit, an input unit, an output unit, and a communication unit;
The computing unit is
A processing region calculation unit for extracting a region to be removed by cutting from the difference between the material shape and the final shape;
A machining process design unit that determines a combination and order of processes from the process candidate data stored in the storage unit, and creates a machining process design plan;
By using tool path data created by 3D CAM according to product CAD model data, material CAD model data, machining area model data, and process candidate data, the post-machining surface accuracy is determined from the geometric elements of the tool and work material for each process. A post-machining surface accuracy calculation unit to calculate,
Said post-machining surface accuracy, compared with the last request surface accuracy is design requirements, after processing surface accuracy to determine whether it satisfies the last request surface precision, and post-process surface accuracy calculated by the post-process surface accuracy computing unit And a surface accuracy comparison processing unit that compares the required surface accuracy before processing of the process candidate storage table stored in the storage unit, and selects process candidates that satisfy the required surface accuracy before processing,
A machining time calculation unit that calculates a machining time for the process design plan created by the machining process design unit,
A machining process design apparatus characterized by comprising: The calculation unit is connected to a 3D CAM, 3D CAD, NC simulator, and NC machine tool via a network.
Or the said calculating part, the said memory | storage part, the said input part, the said output part, and the said communication part are mounted in the same apparatus as the said three-dimensional CAM, The processing process of Claim 6 characterized by the above-mentioned. Design equipment. The output unit displays a model display screen that displays a machining area and a machining path in each process as a two-dimensional or three-dimensional model, and a machining process list screen that displays a machining process design plan as a list of machining processes. The machining process design apparatus according to claim 6. Check the required pre-machining surface accuracy and post-machining surface accuracy of each successive process in the machining process design plan created or input to the computing unit, and the post-machining surface accuracy of the pre-process is the pre-machining required surface of the post-process. Judge whether the accuracy is high or not, and if the post-machining surface accuracy of the previous process is higher than the pre-machining required surface accuracy of the post-process, the machining process surface accuracy is output to indicate that there is a possibility of machining failure A check part,
The processing unit list screen for displaying a machining process design plan as a list of machining processes is explicitly displayed on the output unit as a correction request for a process determined to have a possibility of causing a machining defect. 6. The machining process design apparatus according to 6.

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