JPH11259113A - Tool locus preparing device, its method, article working method, and computer readable storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an article working method for easily and quickly working the shape of an article as a shape including a prescribed machining margin, tool locus preparing method and device and a computer readable storage medium. SOLUTION: The tool locus preparing device temporarily sets up (A, B) the locus of a tool A having a radius R1 on a shape face 1 to be obtained at the completion of a casting mold and synthesizes (C) the locus of the tool A and the locus of a tool A' having a radius R2 (R1<R2) set up on a part to which a working attribute is inputted. Machining work is practically executed by a machining device to which the tool A is attached by using the synthesized locus (NC data). Consequently a working margin to be a difference (R2-R1) of radiuses between both the tools A, A' is left (D) on the part to which the working attribute is inputted as a finishing margin 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of machining a tool used for casting, an article such as an intermediate used for manufacturing the mold, a tool path forming method, a tool path forming apparatus, and a method of manufacturing a tool path. The present invention relates to a computer-readable storage medium.

[0002]

2. Description of the Related Art In recent years, so-called CAD (computer-aided design) and CAE (computer-aided engineering) have been proposed.
With the advancement of technology and the intelligentization of machining equipment, at a manufacturing site, a two-dimensional or three-dimensional shape of an article to be manufactured is generated on a computer, and based on the generated shape data, for example, a machine is used. It is becoming possible to generate even tool trajectory data of a cutting tool or the like used in a processing apparatus.

[0003] However, when cutting an article, it is rare that the entire article can be uniformly machined by a single tool.
There are parts that need to be finished with different tools. Therefore, when generating the tool trajectory, it is necessary to set in advance such that a finishing margin (a margin) is left in the part of the article to be finished. The conventional procedure performed in such a case is outlined below.

FIG. 7 is a diagram for explaining a procedure from generation of a tool path to machining in a conventional example. As shown in the figure, in the conventional procedure, the operator obtains a previously generated completed surface 31 on a computer (A),
A finishing machining allowance 32 is set at a portion included in the shape surface where the finishing is to be performed (B). Next, the operator:
The trajectory 3 of the tool X having the radius R actually used with respect to the shape surface on which the finishing margin 32 is set by the computer.
3 is calculated (C). Then, using the data of the calculated trajectory 33, the operator actually performs a cutting process by a machining device to which the tool X is attached (D), and furthermore, a finishing process allowance 32 by a finishing tool Y. (E).

[0005]

However, in the above-mentioned conventional example, it is difficult to accurately set a portion where finishing is desired to be performed on an article having a complicated shape in a short time.

In order to solve such a problem, for example, in Japanese Patent Application Laid-Open No. 9-62330, the presence or absence of a finishing allowance is determined based on “annotation data” included in the shape data of an article. Although a method of calculating a tool trajectory in consideration of the determination result has been proposed, “annotation data” must be input at the time of design so as to correspond to a portion where a machining allowance is to be left.

Accordingly, the present invention provides a method for processing an article, a method for creating a tool path, a tool path generating apparatus, and a computer-readable storage medium for easily and quickly processing an article into a shape including a predetermined machining allowance. For the purpose of providing.

[0008]

Means for Solving the Problems In order to achieve the above object, a tool path creating method according to the present invention has the following features.

That is, a trajectory of a tool used for machining is created based on the design shape of the article so that the shape surface of the article after machining includes a predetermined machining allowance. A tool locus creation method, wherein in actual machining by the tool, a locus of the tool at the portion is formed by forming a portion of a shape surface including the predetermined machining allowance, and a tip position of the tool is the article. It is created using a virtual tool having a dimension that is offset to the outside of the shape surface of the design shape.

Preferably, the tool actually used for the machining and the virtual tool are ball end mills, and the radius of the virtual tool is actually used for the machining. It is preferable to increase the radius of the tool by the height of the predetermined machining allowance. This allows
The shape of the article is easily and quickly processed into a shape including a target machining allowance.

Further, as a method of processing an article, for example, rough cutting is performed by a tool actually used for the machining based on a tool path created by the tool path creating method of claim 1 or 2 (claim). Item 3), after performing the rough cutting, a portion of the shape surface including the predetermined machining allowance is determined based on a tool path created in accordance with the design shape of the article. It is preferable to perform finishing processing so that

Further, as a method of processing an article, for example, the predetermined machining is performed by producing a cast model by a full mold method based on a tool path created by the tool path creating method according to claim 1 or 2. A casting having a margin can be manufactured (claim 5).

Alternatively, in order to achieve the above object, a tool path creating apparatus according to the present invention has the following configuration.

That is, a trajectory of a tool used for machining is created based on the design shape of the article so that the shape surface of the article after machining includes a predetermined machining allowance. A tool trajectory creating device, a first trajectory creating means for creating a tool trajectory based on a design shape of the article and dimensions of a tool actually used for the machining, and an actual machine using the tool; In forming, in order to form a portion of the shape surface including the predetermined machining allowance, the trajectory of the tool at that portion is adjusted such that the tip position of the tool is offset outside the shape surface in the design shape of the article. A second trajectory creating unit created by a virtual tool having dimensions; and a trajectory of the actually used tool is created based on the tool trajectory created by the first and second trajectory creating units. Characterized in that it comprises a trajectory creating means.

Preferably, as a seventh aspect, the tool actually used for the machining and the virtual tool are ball end mills, and the radius of the virtual tool is actually used for the machining. It is preferable to increase the radius of the tool by the height of the predetermined machining allowance. This allows
The shape of the article is easily and quickly processed into a shape including a target machining allowance.

Further, the present invention is characterized by a computer-readable storage medium for operating a computer as an apparatus for realizing the above-mentioned tool path creating apparatus.

[0017]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a tool locus generating apparatus according to an embodiment of the present invention;

In the following description, it is assumed that a general method is used for calculating the tool trajectory based on the shape surface at the time of completion of the casting mold, and the description in this embodiment is omitted.

[First Embodiment] In the first embodiment,
In order to complete an unfinished die cast in advance to the dimensions according to the design shape, for a desired portion, the die is cut into a shape including a predetermined machining allowance by a tool A, and further by a tool B. The case where the desired portion is subjected to finishing processing will be described as an example. In this embodiment, a ball end mill having a spherical tip with a radius R1 is assumed as the tool A used for actual machining (see FIG. 5).

FIG. 1 is a diagram for explaining a procedure from generation of a tool path to machining according to the first embodiment of the present invention.

As shown in FIG. 1, in this embodiment, a completed shape surface 1 of a casting mold to be manufactured, which is generated in advance by an external device or the like, is prepared in a tool path creating device (A). On the other hand, the tool A having the radius R1 actually used in the subsequent process
Is temporarily calculated (B). The tentatively calculated locus 2 of the tool A need not be displayed on the screen.

Next, the operator inputs a machining attribute for the shape of the casting die displayed on the screen of the tool path creating device by designating a portion where a finishing machining allowance is to be left.

The tool trajectory creating apparatus calculates the trajectory of the virtual tool A 'having a radius R2 (where R1 <R2) (the trajectory 3 indicated by a thick line in the figure) with respect to the portion where the machining attribute is input. Then, based on the calculated trajectory 3 of the tool A 'and the tentatively calculated trajectory 2 of the tool A, the trajectory of the actual movement of the tool A is calculated (C). Specifically, when the trajectories of the tool A and the tool A ′ overlap each other around the shape surface of the casting mold, the coordinate values of the casting mold in the overlapping portion and the tool A in that portion Based on the coordinate value of the locus of the tool A ′, the coordinates (trajectory) of the tool farther from the shape surface of the casting mold may be sequentially selected.

Then, the operator uses the data representing the trajectory calculated in (C) to actually perform the cutting by the machining device equipped with the tool A (D).
By the cutting with the tool A, the difference between the radius of the tool A and the tool A ′, that is, (R2- The processing allowance of R1) can be left on the shape surface.

Thereafter, the operator uses a tool B (not shown) different from the tool A to finish machining allowance 4 in the machining apparatus.
To perform the cutting process. The tool trajectory at this time may be calculated by a general method based on the radius of the tool B only for the portion of the finishing allowance 4 to be cut.

FIG. 2 is a block diagram of a tool trajectory creating apparatus according to a first embodiment of the present invention. For example, a personal computer may be used.

In the figure, reference numeral 12 denotes a display such as a CRT. Reference numeral 13 denotes a keyboard as input means. 14
Is a ROM storing a boot program and the like.
Reference numeral 15 denotes a RAM for temporarily storing various processing results. 1
6 is an engineering workstation (EW)
S) A three-dimensional shape data file of the casting mold generated at 21 or the like, a program for performing a tool path creation process described later, and a program for creating so-called NC data in accordance with the tool path created by the tool path creation processing And a storage device such as a hard disk drive (HDD) for storing the information. 17 is a communication line 20 with an external device.
This is a communication interface for communicating via. These components are connected via an internal bus 19, and the CPU 11 controls the entire tool trajectory creating device according to a program stored in the storage device 16.

The NC data representing the tool trajectory calculated by the tool trajectory creating device is transferred to a machining device 22 such as an NC (numerical control) machining device via a communication line 20, and the transferred NC data is transferred to the NC device. Used, the machining device 22 performs cutting and the like.

The tool trajectory creating device shown in FIG. 2 is configured separately from the machining device 22, but it is needless to say that it may be an integrated device.

FIG. 3 is a flowchart showing a tool trajectory creation process according to the first embodiment of the present invention, which shows a process performed by the tool trajectory creation device. At the start of the processing shown in this flowchart, it is assumed that the radii of the tool A and the tool A 'are registered in advance. In the figure, step S1: three-dimensional shape data is obtained from the EWS 21 or the like via the storage device 16 or the communication line 20 as a shape surface when the casting mold is completed.

Step S2: The trajectory 2 of the tool A having the radius R1 actually used in the subsequent process is temporarily calculated over the entire shape surface 1.

Step S3: The shape of the casting mold is displayed on the display 12, and the operator is caused to input a part (processing attribute) for which a finishing machining allowance is to be left using a pointing device such as a mouse.

Step S4: The trajectory 3 of the tool A 'having the radius R2 is calculated for the part for which the machining attribute has been input in step S3.

Step S5: Based on the trajectory 3 of the tool A 'calculated in step S4 and the trajectory 2 of the tool A tentatively calculated in step S2, a trajectory where the tool A actually moves is calculated.

Step S6: The trajectory calculated in step S4 is output as NC data used by the machining device 22 to the machining device 22 via the communication line 20.

As described above, according to the present embodiment, the shape of the casting mold is changed by the procedure described with reference to FIG. 1 and the tool locus creating device that performs the tool locus creating process shown in FIG. , Easily and quickly the desired shape,
It can be processed into a shape including a machining allowance.

<Modification of the First Embodiment> FIG.
In the example of the above, the finish machining allowance 4
And the example in which the machining allowance 4 is cut by the tool B (not shown) has been described. In this modification, as shown in FIG.
By leaving the roughing allowance 6 and the finishing machining allowance 7 on the shape surface for the portion where the machining attribute is input, it is possible to prepare so that the finishing process can be performed on the portion in a plurality of stages.

In this case, first, in the first machining, the sum of the height of the rough machining allowance 6 and the height of the finish machining allowance 7 is the difference between the radius of the tool A and the virtual tool A '(R2-R
The tool A 'may be selected and the above-described tool path creation processing may be performed so that 1) is satisfied.

Next, in the second machining, the height of the finishing machining allowance 7 is set to the tool A (here, the tool A used for the second machining is 1 so that the rough machining allowance 6 is cut). It goes without saying that the finished surface is smoother than the tool A used for the second machining) and the tool A 'is selected so that the difference between the radius of the tool A' (R2-R1) is obtained. The above-described tool path creation processing may be performed.

Further, in the third machining, only the portion of the finishing machining allowance 7 to be cut is subjected to a general method based on the radius of the tool B so that the finishing machining allowance 7 is cut. What is necessary is just to calculate a tool path.

[Second Embodiment] In this embodiment, a case where the present invention is applied to the production of a cast model made of expanded polyethylene (styrene foam) by a so-called full mold method, which is an intermediate used in the production of a casting mold. Will be described. The basic concept is the same as in the case of directly manufacturing the casting mold described above, but when manufacturing a casting model by the full mold method, the casting model to be manufactured is the same as the shape of the casting mold designed in advance. Instead, it is necessary to have a large shape with a machining finish.

Further, similarly to the modification of the first embodiment,
By performing the tool path creation processing of FIG. 3 in a plurality of stages,
It goes without saying that a part of the casting model may be finished.

According to the present embodiment, a desired shape, that is, a shape of a cast model including a machining allowance can be easily and quickly processed. Therefore, by using the casting model, a casting mold including the machining finish can be rapidly manufactured.

In the example of FIG. 1 described above, the tool is a ball end mill, and the finishing machining allowance 4 is realized by using the difference in radius between the tool A and the tool A. However, the present invention is not limited to this. For example, in a mill having a rectangular tip such as a tool C shown in FIG. 6, a tool having a different distance L from the main shaft 5 of the machining apparatus and paying attention to the distance L may be used. It is only necessary to realize the finishing allowance 4 by utilizing the offset amount from the shape surface 1 at the time of completion caused by the above.

Further, in the tool trajectory creating apparatus according to the above-described embodiment, the operator inputs the machining attribute. However, a part to be finished is divided into a database according to the use of the article to be machined, and the database is referred to. , The processing attribute can be automatically set.

In the above-described embodiment, software for realizing the operation shown in the flowchart of FIG. 3 is stored in a storage medium such as a floppy disk, and the information in the storage medium is read into a personal computer, for example. Accordingly, it is needless to say that the present invention can be applied to a case where the computer is operated as the tool trajectory creating apparatus according to the present embodiment.

[0047]

As described above, according to the present invention,
An object processing method, a tool path creation method, a tool path creation apparatus, and a computer-readable storage medium for easily and quickly processing an article shape into a shape including a predetermined machining allowance are realized.

[0048]

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a procedure from tool path generation to machining according to a first embodiment of the present invention.

FIG. 2 is a block diagram of a tool path creation device as a first embodiment of the present invention.

FIG. 3 is a flowchart illustrating a tool trajectory creation process according to the first embodiment of the present invention.

FIG. 4 is a diagram illustrating a case in which a roughing allowance and a finish machining allowance are left on a shape surface for a part to which a machining attribute has been input;

FIG. 5 is a view showing a ball end mill as a tool A.

FIG. 6 is a view showing a tool C having a rectangular tip.

FIG. 7 is a diagram illustrating a procedure from generation of a tool path to machining in a conventional example.

[Explanation of symbols]

 1, 31: Shape surface at completion, 2, 3, 33: Tool path, 4, 7, 32: Finishing allowance, 5: Spindle, 6: Rough cutting allowance, 11: CPU, 12: Display, 13: Keyboard, 14: ROM, 15: RAM, 16: storage device, 17: communication interface, 19: internal bus, 20: communication line, 21: EWS, 22: machining device,

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Takanori Sakamoto 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Co., Ltd.

Claims (8)

[Claims] 1. A tool trajectory creating method for creating a trajectory of a tool used for machining based on a design shape of the article such that a shape surface of the article after machining includes a predetermined machining allowance. In order to form a portion of the shape surface including the predetermined machining allowance in actual machining by the tool, the trajectory of the tool at that portion is determined by changing the tip position of the tool to the shape in the design shape of the article A tool path creation method, wherein the tool path is created using a virtual tool having a dimension that is offset to the outside of a surface. 2. The tool actually used for the machining and the virtual tool are ball end mills, and the radius of the virtual tool is more than the predetermined radius of the tool actually used for the machining. 2. The tool path creation method according to claim 1, wherein the height is larger by the height of the machining allowance. 3. A method for processing an article, comprising: performing rough cutting with a tool actually used for the machining based on a tool path created by the tool path creation method according to claim 1 or 2. 4. After performing the rough cutting, a portion of the shape surface including the predetermined machining allowance is formed based on a tool path created according to the design shape of the article in the design shape of the article. 4. The method of processing an article according to claim 3, wherein the surface is subjected to a finishing process. 5. A method for processing an article, comprising: producing a cast model by a full mold method based on a tool path created by the tool path creating method according to claim 1 or 2. 6. A tool trajectory creating apparatus that creates a trajectory of a tool used for machining based on a design shape of the article so that a shape surface of the machined article includes a predetermined machining allowance. A first trajectory creating means for creating a tool trajectory based on a design shape of the article and a dimension of a tool actually used for the machining; and In order to form a portion of the shape surface including the machining allowance, the trajectory of the tool at that portion is assumed to have a size such that the tip position of the tool is offset outside the shape surface in the design shape of the article. The second created by a simple tool
Trajectory creating means, and actual trajectory creating means for creating the trajectory of the actually used tool based on the tool trajectory created by the first and second trajectory creating means. Trajectory creation device. 7. The tool actually used for the machining and the virtual tool are ball end mills, and the radius of the virtual tool is more than the predetermined radius of the tool actually used for the machining. 7. The tool path creation device according to claim 6, wherein the height is larger by the height of the machining allowance. 8. A tool trajectory creating process for creating a trajectory of a tool used for machining based on a design shape of the article so that a shape surface of the machined article includes a predetermined machining allowance. A computer-readable storage medium storing a program, wherein the storage medium creates a tool path based on a design shape of the article and dimensions of a tool actually used for the machining. First trajectory creating means, and in actual machining with the tool, in order to form a portion of the shape surface including the predetermined machining allowance, the trajectory of the tool at that portion is referred to as a tip position of the tool. Created by a virtual tool having a dimension that is offset outside the shape surface in the design shape of
And a storage medium that operates as an actual trajectory creating means for creating the trajectory of the actually used tool based on the tool trajectory created by the first and second trajectory creating means. .