JP7127803B2 - Process design system and process order determination method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a process design system for designing a process for obtaining an object having a predetermined shape by removing a part of a material by cutting or the like, and a process sequence determination method.

At present, NC machine tools are used in many manufacturing sites because they can machine required parts with high precision and high efficiency. In addition, software such as CAD/CAM that assists creation of NC programs used in NC machine tools has been developed.

However, with the conventional CAM software, the process design such as selection of the machining area and determination of the machining order must be done manually, and it is necessary to spend a huge amount of work time on this design. Machining using an NC machine tool requires the creation of an NC program for each product, which poses the problem of an enormous amount of setup work time.

Therefore, development of a process design system that executes process design by computer is required. In Patent Document 1, the region to be removed by processing is divided once by all planes including the planar portion of the surface of the region, and the divided regions are reconfigured with a plurality of types of combinations, and the reconfigured region is obtained. describes a technique for generating a plurality of machining process candidates by determining the machining order and machining conditions.

JP-A-2005-309713

However, in the automation of process design as described in Patent Document 1, one machining process is determined by geometric constraints, etc., but geometric constraints alone do not necessarily shorten the machining time. However, it is not always possible to determine the processing order.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a process design system capable of automatically deriving one machining process to be used in actual machining, and a machining order determination method.

In order to achieve the above object, a process design system that is one aspect of the present invention is a process design system that determines a process for obtaining an object having a predetermined shape by processing a plurality of removal areas of a material. a tree obtaining unit for obtaining an order tree representing a hierarchical structure of candidates for the processing order of the removal area derived by limiting the processing order of the removal area based on geometric constraints; A removal area information acquisition unit that acquires removal area information including geometric features of the removal area corresponding to each node of, removal area information of the removal area processed with another material, and processing the removal area a performance information acquisition unit for acquiring performance information in which processing example information associated with actual processing conditions is accumulated; The priority of the matching unit that searches for and applies the performance information acquired by the unit and the order of removing the removal area that exists in the upper hierarchy in the order tree is high, and the tools in the applied machining conditions are larger and an order determination unit that determines the process using the priority condition that the removal area corresponding to the tool has a high priority in the order of removal.

According to this, it is possible to automatically design a process suitable for the shape of the material and the object, and it is possible to shorten the setup time before manufacturing.

In addition, the order determination unit determines the process by adding a condition that prioritizes a tool that can remove all the corresponding removal areas in the geometric constraint condition to the priority condition to determine the process. You may

According to this, when all the removal areas that can be approached with one type of tool are removed, the removal area to be removed with the tool does not remain in all the remaining removal areas. This condition has a wide range of application, and it is possible to reduce the number of times the tool is held and to shorten the machining time.

The order determination unit may determine the processes by adding to the priority condition a condition of prioritizing an area to be machined with only one tool with respect to all removal areas. According to this, the process design time can be shortened.

Further, in order to achieve the above object, there is provided a machining order determining method for fabricating a part by machining and removing a material, wherein the machining order of a plurality of removal areas from the material is determined. When determining the machining order from candidates for the machining order of the removal area having an order tree represented by a hierarchical structure that is limited and derived based on geometric constraints, each condition is determined in the order described below. A machining order determination method that is applied to determine the machining order.

Condition 1: Prioritize a tool that can remove all of the corresponding removal areas in the geometric constraint, or give priority to an area that can be machined with only one tool for all removal areas Condition 2: In the order tree Priority is given to the removal area that exists in the upper hierarchy. Condition 3: Regarding the tool within the applied machining conditions, the removal area that corresponds to a larger tool is given priority.

According to this, it is possible to determine the processing order of the container even when the material and the shape of the object are new, and it is possible to shorten the setup time before manufacturing.

It should be noted that executing a program for causing a computer to execute each process included in the process design system also corresponds to the implementation of the present invention. Of course, carrying out the recording medium on which the program is recorded also corresponds to carrying out the present invention.

According to the present invention, it is possible to automatically derive a machining process capable of shortening the machining time based on the geometric conditions of the removal area based on data on the shape of the material and the shape of the object.

It is a block diagram which shows the functional structure of a process design system. FIG. 3 is a perspective view showing the material, object and total removal area; FIG. 4 is a perspective view showing a total removed area; Fig. 3 shows an ordered tree; FIG. 10 is a diagram showing processing conditions applied to an order tree; It is a flowchart which shows operation|movement of a process design system. Fig. 2 shows a first-stage order tree in the process of determining the order and the determined order; Fig. 2 shows a second stage order tree in the process of determining the order and the determined order; FIG. 13 shows a third-stage order tree in the process of determining the order and the determined order; It is a figure which shows the determined process.

Next, an embodiment of a process design system according to the present invention will be described with reference to the drawings. It should be noted that the embodiments described below are all comprehensive or specific examples. Numerical values, shapes, materials, components, arrangement positions and connection forms of components, steps, order of steps, and the like shown in the following embodiments are examples and are not intended to limit the present invention. In addition, among the constituent elements in the following embodiments, constituent elements that are not described in independent claims representing the highest concept will be described as arbitrary constituent elements.

In addition, the drawings are schematic diagrams in which emphasis, omissions, and ratios are appropriately adjusted in order to illustrate the present invention, and may differ from actual shapes, positional relationships, and ratios.

FIG. 1 is a block diagram showing the functional configuration of the process design system. FIG. 2 is a perspective view showing the material, object and removal area. FIG. 3 is a perspective view showing the total removed area. As shown in these figures, the process design system 100 according to the present embodiment is a system for designing a processing process for obtaining an object having a predetermined shape by partially removing a material 200 made of metal, resin, or the like. , and is a system realized by causing a computer to execute software (programs). The process design system 100 also acquires information from the CAD 300, the support system 301, and the expert system 302, and outputs the information of the process designed based on the acquired information to the CAM 303. FIG. A computer is an electronic computer having a CPU (Central Processing Unit), input/output means such as a display device and an input device, and storage means such as a memory and an external storage device.

First, based on the shape of the material 200 created by the CAD 300 or the like and the shape of the target object 201, the support system 301 limits the possibilities of the processing order of the removal region 202 based on geometric constraints, and creates a hierarchical structure. is a system that creates an ordered tree represented by

The method by which support system 301 creates the ordered tree is not particularly limited. An example of the support system 301 will be described here.

First, the support system 301 extracts a total removal area 203 that is a difference area between the shape of the material 200 and the shape of the object 201 .

The shape of the material 200 and the shape of the target object 201 are obtained from a computer implementing the support system 301 or a so-called CAD 300 executed by another computer. In addition, the support system 301 acquires a plane part existing on the surface of the total removal area 203, or divides the total removal area 203 into a number of temporary areas obtained by dividing the total removal area 203 by one temporary plane including the plane part. is obtained for each virtual plane.

This is because by using the total removal area 203, even if the shape of the object 201 is the same, if the shape of the material 200 is different, the removal order is not necessarily the same because the shape of the removal area is different. In addition, when the machining is interrupted due to a trouble occurring during the machining, the order of machining can be determined again, and an improvement in the flexibility of the process design system 100 can be expected.

Next, the support system 301 divides the extracted total removal area 203 by planes to extract divided removal areas. The selection of the planes for dividing the total removal area 203 is not particularly limited, but here the planes are determined as follows.

For the extracted total removal area 203, a plane included in the total removal area 203 is searched, and when the plane is divided by the plane, three or more divided removal areas are generated (for example, the plane 204 shown in FIG. 3). ). Then, the total removal area 203 is divided by the extracted plane to extract the divided removal areas. If there are planes that can be further divided into three or more regions for the extracted division removal region, division is performed again. This operation is repeated until division into three or more regions becomes impossible. Finally, if the extracted divided removal area can be divided on the planes forming the divided removal area, the removal area is extracted by further dividing the divided removal area.

Next, the support system 301 generates an order tree represented by a hierarchical structure as shown in FIG. The method of generating the order tree 400 is not particularly limited as long as it is based on geometric constraints, but here the order tree 400 is generated as follows.

In actual machining, geometric constraints arise because the tool can only approach removal areas that have open faces, which are surfaces exposed to the atmosphere. For example, in the shape of the object 201 shown in FIG. 2, the removal areas that can be machined from the shape of the initial material 200 are the first removal area 210, the second removal area 220, and the third removal area that can contact the tool. Limited to 230. The fourth removal region 211 and the fifth removal region 212 can be processed when the first removal region 210 is removed by processing. When removed by processing, processing becomes possible. Considering the geometrical constraints of tooling accessibility in this way, a hierarchical ordered tree 400 can be created as shown in FIG. The order tree 400 can express the subordinate relationship of each machining region, and can limit a large number of machining order candidates.

Next, the process design system 100 will be described. The process design system 100 is a system that obtains an order tree 400 generated by a support system 301 to obtain an object 201 having a predetermined shape, and determines one process from the obtained order tree 400 . As shown in FIG. 1, the process design system 100 includes a tree acquisition unit 101, a removal area information acquisition unit 102, a performance information acquisition unit 103, a matching unit 104, and an order determination unit as processing units that can be implemented by a computer. 105.

The tree acquisition unit 101 is an order tree 400 represented by a hierarchical structure created by the support system 301, and processes the removal area derived by limiting the machining order of the removal area 202 based on geometric constraints. It is a processing unit that acquires an order tree 400 indicating order candidates. The method of acquiring the sequence tree 400 from the support system 301 is not particularly limited, and communication, movement of a medium storing the sequence tree 400, and the like can be exemplified.

The removal area information acquisition unit 102 is a processing unit that acquires removal area information including geometric features of the removal area 202 corresponding to each node of the order tree 400 acquired by the tree acquisition unit 101 . A node here means a node in a tree structure, and includes all meanings of a root node, an internal node, and a leaf node. One node in the order tree 400 corresponds to one removal region 202 . In the case of this embodiment, the removal area information is acquired from the support system 301 . The acquired removal area information includes the size of the removal area 202, the position of the center of gravity of the removal area 202 represented by XYZ coordinates, etc., the depth of the removal area 202 in the direction in which a tool such as a cutting tool penetrates, and the depth of the removal area 202. The shape of the removal area 202 on the plane orthogonal to the direction in which the tool or the like penetrates, whether the removal area 202 penetrates the object, and the difference between the removal area corresponding to the parent node and the removal area corresponding to the sibling node. A distance, for example, a distance between centers of gravity can be exemplified. Furthermore, the geometric information may be determined based on the shape of the removal area 202, and may include a virtual shape such as a virtual rectangular parallelepiped that can contain the removal area and has the smallest volume. information may be defined.

The performance information acquisition unit 103 is a processing unit that acquires performance information from the expert system 302 . The record information is information accumulated by the expert system 302, and includes machining example information in which the removal area information of the removal area machined with a different material and the machining conditions at the time of machining the removal area are linked. It is a constructed database. In the case of the present embodiment, the actual result information adopts processing conditions when processing by a so-called skilled engineer. Machining conditions include, for example, the type of tool for removal machining, the rotational speed of the tool, the feed rate of the tool, the depth of cut in the radial direction, the depth of cut in the axial direction, whether or not cutting oil is used, and the type of cutting oil. , the mass of the removed area, the material, the state of finish, the dimensional tolerance, and the like.

The matching unit 104 is a processing unit that searches the performance information acquired by the performance information acquisition unit 103 and applies the processing conditions corresponding to the removal area information of each node acquired by the removal region information acquisition unit 102 . In the case of the present embodiment, the matching unit 104 searches for the processing example that has the most similar features of the removal area information corresponding to the removal area 202 from the performance information, and based on the obtained result, each node of the order tree 400 One processing condition is applied to each removal area 202 . As a result, machining conditions are determined such that machining troubles such as tool breakage do not occur. FIG. 5 is a diagram showing processing conditions applied to an order tree. As shown in the figure, "EM" means an end mill, and the number attached to the side of "EM" is an identifier indicating the type of end mill. The identifier indicates the diameter size, material, etc. of the end mill. Moreover, it has shown that it is a large sized tool, so that a numerical value is large. In the case of this embodiment, the numerical value indicates the diameter of the end mill.

The order determination unit 105 is a processing unit that determines one process for processing the material 200 from the order tree 400 to obtain the object 201 based on a predetermined condition. In the case of this embodiment, the objective function is the number of tool changes, and the machining order is determined so as to minimize it. The objective function may include the minimization of the total travel time of the tool from the previously machined removal area to the next machined removal area. Also, the following three conditions are applied as predetermined conditions in the stated order, and one step, that is, the machining order is determined from the order tree 400 that is a set of a plurality of steps.

Condition 1: Priority is given to tools that can remove all of the corresponding removal areas in the geometrical constraint.
Condition 2: Priority is given to regions existing in higher hierarchies in the order tree.
Condition 3: Priority is given to areas where tools with larger tool diameters are used than others.

In Condition 1, all removal regions 202 that can be removed using a single tool are limited to all removal regions 202 that can be machined because they are directly approachable by the tool, subject to geometric constraints. are removed, the tool is no longer used after that, so the tool change is only before and after machining these removed areas 202 . By preferentially removing the removal region 202 to be removed using such a tool, it is possible to remove the region of the lower hierarchy in a situation where there are few tool changes.

In condition 2, since the removal area 202 that exists in the upper hierarchy in the order tree 400 is the removal area 202 that is geometrically easy for the tool to approach, by machining the easy-to-machine area first, the removal area 202 that exists in the lower hierarchy is removed. The approach of the tool to the removal area 202 to be removed can be facilitated.

In condition 3, it is conceivable that the removal area 202 removed using a large-sized tool having a larger tool diameter also has a large removal volume. By preferentially processing the area with a large removal volume, it is possible to facilitate the approach of the tool to the area to be subsequently processed.

According to the above conditions, the machining order is determined as follows based on the order tree 400 with machining conditions shown in FIG. 5, for example. Note that the order tree 400 is a directed tree structure. In the order tree 400, the removal area 202 approachable by the tool becomes the root, and when the root is removed, the node immediately below the previous root becomes the new root. In the case of the present embodiment, since the first removal region 210, the second removal region 220, and the third removal region 230 are all the removal regions 202 that can be approached with a tool, there are multiple routes. Since it is a process of removing one material 200, it is treated as one order tree 400. FIG.

FIG. 6 is a flow chart showing the operation of the process design system. As shown in the figure, the process design system 100 first extracts a root from the order tree 400 (S101).

If a plurality of removal areas 202 are extracted (S102: No), then condition 1 is applied to the extracted route (S103). In the case of this embodiment, the tool EM8 is used only for the second removal area 220, which is a removable area, and therefore Condition 1 is satisfied. Similarly, the condition 1 is satisfied because the tool EM4 is used only for the third removal area 230, which is a removable area. Therefore, when the second removal area 220 is processed using the tool EM8, none of the remaining removal areas 202 are removed using the tool EM8. Similarly, when the third removal area 230 is machined using the tool EM4, none of the remaining removal areas 202 will be removed using the tool EM4. From the above, there are a plurality of removal regions 202 corresponding to Condition 1, although the removal regions 202 to be removed are narrowed down to the second removal region 220 and the third removal region 230 .

Next, when condition 2 is applied to the narrowed removal region 202 (S104), since the second removal region 220 and the third removal region 230 are in the same hierarchy in the order tree 400, they cannot be narrowed down to either one. , a plurality of removal regions 202 corresponding to condition 2 remain.

Next, when condition 3 is applied to the remaining root (S105), the second removal area 220 using the tool EM8 whose tool diameter is larger than the tool EM4 of the third removal area 230 corresponds to condition 3. The removal area 202 corresponding to is singular.

Therefore, the removal area 202 to be removed first is determined as the second removal area 220 .

In addition, when the removal area 202 cannot be narrowed down to a single number even if the conditions up to condition 3 are applied (S105: No), the process design system 100 gives priority to other conditions, for example, the removal area 202 that minimizes tool movement. The order is determined according to such conditions (S107).

Next, since the order of all removal regions 202 has not been determined (S108: No), the second removal region 220, which is the root whose order has been determined, is removed from the order tree 400 (S109), and the root is extracted again. (S101).

Thus, an order tree 400 as shown in FIG. 7 is formed. Specifically, the removal area 202, which is the route that can be approached by the tool, includes a first removal area 210, a third removal area 230, and a sixth removal area 221 and a seventh removal area 222, which are removal areas in the lower layer. is extracted.

When Condition 1 is applied to the extracted route, if the removal area that can be approached by the tool EM6 is removed, there is no removal area 202 to be removed using the tool EM6. Therefore, the first removal area 210, the sixth removal area 221, and the seventh removal area 222 correspond. Since the tool EM4 is similar, the third removal area 230 is also applicable.

Since the first removal area 210 and the third removal area 230 are on the same layer, the condition 2 cannot be narrowed down, so the condition 3 is applied. The removal regions 202 (removal regions 210, 221, 222) using the tool EM6 with a large tool diameter are preferentially removed.

In this case, since there are a plurality of priority removal areas 202 (three areas in this embodiment), the process design system 100 applies Condition 2 as another condition, and the first removal area 210 existing in the upper hierarchy , and regarding the sixth removal region 221 and the seventh removal region 222, the order is determined according to conditions such as prioritizing the removal region 202 with the least movement of the tool.

Thus, an order tree 400 as shown in FIG. 8 is formed. Specifically, the removal area 202, which is a route that can be approached by the tool, is the third removal area 230, a removal area in the hierarchy below it. A fourth removed region 211 and a fifth removed region 212 remain as ordered tree 400 .

Next, applying Condition 1 to the extracted routes, all remaining routes are applicable. Next, when condition 2 is applied, only the third removal area 230, which is the upper hierarchy, is applicable. Therefore, the third removal area 230 is determined as the next priority.

Finally, as shown in FIG. 9, a fourth removal area 211 and a fifth removal area 212 remain, but since these cannot be ranked according to conditions 1 to 3, they are ranked according to other conditions.

As a result of the above, as shown in FIG. 10, the processing order is as follows. Second removal region 220 →first removal region 210 →sixth removal region 221 →seventh removal region 222 →third removal region 230 →fourth removal region 211 →fifth removal region 212 .

As described above, the process design system 100 according to this embodiment can determine one process out of a plurality of processes. Further, the determined process is based on the database based on the achievements of experts constructed by the support system 301, so it is a realistic and rational process.

Specifically, processes were created by the process design system 100 for forming multiple types of objects from multiple types of materials, and actual processing was performed according to the created processing order. It was confirmed that the process determined by the process design system 100 of this embodiment can be automatically processed without problems.

It should be noted that the present invention is not limited to the above embodiments. For example, another embodiment realized by arbitrarily combining the constituent elements described in this specification or omitting some of the constituent elements may be an embodiment of the present invention. The present invention also includes modifications obtained by making various modifications to the above-described embodiment within the scope of the gist of the present invention, that is, the meaning of the words described in the claims, which a person skilled in the art can think of. be

In the above embodiment, the case of determining the process of end milling using a milling machine has been described, but the present invention is not limited to this. For example, the process design system 100 can also be applied to lathe machining. In this case, since the material is rotating, the surface approached by the bit, which is a cutting tool, is a cylindrical surface.

Also, although the process design system 100 and the support system 301 have been described as separate entities, the support system 301 may be incorporated in the process design system 100 as a tree creating unit.

In addition, the condition 1 was set to give priority to a tool capable of removing all of the corresponding removal regions in the geometric constraint conditions. A condition of prioritizing areas not to be processed may be used. According to this, it becomes possible to simplify the process of process determination.

It is also possible to determine the process based on conditions 2 and 3 without judging condition 1.

INDUSTRIAL APPLICABILITY The present invention can be used for designing processing steps when manufacturing an object using an NC processing machine or the like.

100 process design system 101 tree acquisition unit 102 removal area information acquisition unit 103 performance information acquisition unit 104 matching unit 105 order determination unit 200 material 201 object 202 removal area 203 total removal area 204 plane 210 first removal area 211 fourth removal area 212 fifth removal region 220 second removal region 221 sixth removal region 222 seventh removal region 230 third removal region 301 support system 302 expert system 400 ordered tree

Claims (4)

A process design system for determining a process for processing a plurality of removal areas of a material to obtain an object of predetermined shape,
a tree obtaining unit that obtains an order tree representing a hierarchical structure of candidates for the processing order of the removal area derived by limiting the processing order of the removal area based on geometric constraints;
a removal area information obtaining unit for obtaining removal area information including geometric features of the removal area corresponding to each node of the order tree;
a performance information acquisition unit that acquires performance information in which processing example information in which removal region information of a removal region processed with a different material and processing conditions when processing the removal region are linked is accumulated;
a matching unit that searches the performance information acquired by the performance information acquisition unit and applies processing conditions corresponding to each of the removal area information acquired by the removal region information acquisition unit;
Apply the condition that preferentially removes the removal area that exists in the upper hierarchy in the order tree, and then remove the removal area that corresponds to the larger tool preferentially for the tool within the applied machining conditions. A process design system, comprising: a sequence determination unit that determines a process by applying conditions . The order determination unit
If all the removal areas that can be approached with one type of tool are removed before applying the condition to preferentially remove the removal area that exists in the upper hierarchy in the order tree, all the remaining removal areas are covered with the tool. 2. The process design system according to claim 1, wherein the process is determined by adding a condition that priority is given to a removal area that does not remain in the removal area to be removed by . The order determination unit
Prior to applying the condition to preferentially remove the removal area existing in the upper hierarchy in the order tree, the removal area to be removed by a tool that does not remove other removal areas, and is among all the removal areas 2. The process design system according to claim 1, wherein the process is determined with the addition of a condition that priority is given to a removal area in which only one exists . A processing order determination method for manufacturing parts by processing and removing materials,
A case where the machining order is determined from candidates for the machining order of the removal regions having an order tree represented by a hierarchical structure derived by limiting the machining order of the plurality of removal regions from the material based on geometric constraints. In addition, a processing order determination method for determining the processing order by applying each condition in the order described below.
Condition 1: When all removal areas that can be approached with one type of tool are removed, priority is given to a removal area in which the removal area to be removed with the tool does not remain in all remaining removal areas , or other Priority is given to a removal area that is removed by a tool that does not remove the removal area and that exists only in one removal area among all removal areas. Condition 2: Priority is given to a removal area that exists in a higher hierarchy in the order tree Condition 3: For tools within the applied machining conditions, give priority to the removal area that corresponds to a larger tool

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