JPH07244518A - Method for preparing nc working tool cutting route and device thereof - Google Patents

Abstract

PURPOSE:To simply and quickly execute the check of interference between a shape face and a cutting tool by rotating shape face data and tool cutting route data by coordinate transformation so that a working direction is turned to a specific direction and then checking interference between a tool system model and the shape face data. CONSTITUTION:The cutting tool 1 is detachably fixed to a tool head H fixed to the tip of a main shaft A of an NC working machine through a tool chuck C in an inclined state from an NC shaft z. The main shaft A and the tool head H can be optionally rotated respectively in arrow M and N directions. Shape face data and tool cutting route data are rotated by coordinate transformation so that the working direction is turned to the Z axis direction of the NC working machine and then interference between the tool system model and the shape face data is checked. Thereby the shape face data to be checked at its interference can be extracted from both upper and lower ends of the tool system model.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for creating a cutting path for NC processing, and more specifically, NC data for an NC processing machine for performing die processing using a computer-aided design system, that is, The present invention relates to a method and an apparatus for creating a tool cutting path.

[0002]

2. Description of the Related Art In recent years, computer aided design systems
(Hereinafter, referred to as CAD / CAM system) is becoming widespread and applied to various industrial fields. In particular, the CAD / CAM system that handles a three-dimensional shape model is widely applied from the conceptual stage of design to the simulation of production.

As an example of use of such a CAD / CAM system, an operation program (ie, NC data) of an NC processing machine for cutting a press die for an automobile member (eg, side sill, fender panel, etc.) is automatically created. There is something to do. In this case, the CAD / CAM system stores the shape surface data of the automobile member composed of the free-form surface as a database.
The M system creates tool cutting path data (that is, NC data) by processing the shape surface data.

By the way, an automobile member is usually composed of a complicated free-form surface portion, and moreover, the free-form surface portion has a portion which is largely curved or bent. Therefore, if a tool cutting path that avoids the interference between the cutting tool for cutting the die and the shape surface data is created and the NC processing machine is not driven based on the tool cutting path data obtained in this way, the cutting tool will not work. There is a possibility that it may interfere with the machined surface and the accurate cutting surface may not be obtained, or the NC machine itself may be damaged.

In order to deal with the above-mentioned problems, as a method for avoiding the interference between the cutting tool and the machining surface adjacent to the tool cutting path, when the tool cutting path data for the die machining is created, Curved surface data corresponding to the mold surface data is converted into multiple tangential plane data composed of triangles, and the tool cutting path data is created by checking the interference of the cutting tool with each tangential plane data. Has been proposed (see, for example, JP-A-63-24304).

However, in the case of the above method,
Since the curved surface data corresponding to the mold surface data must be converted into multiple tangent plane data composed of triangles and the interference of the cutting tool with each tangent plane data must be checked, the processing work becomes complicated. In addition, there is a problem that a great deal of processing time is required.

On the other hand, when cutting a metal mold for an automobile member (for example, a side sill) having a shape surface F shown in FIGS. 8 and 9, generally, the tool axis O of the cutting tool 1 is NC.
It is carried out by fixing so as to become the Z axis of the processing machine. In this case, when performing the interference check using the CAD / CAM system, the interference check range based on the maximum diameter portion 2a of the tool holder 2 holding the cutting tool 1 is set,
Since it suffices to perform the interference check, the interference check range can be small. However, for example, when trying to perform cutting along the tool cutting path indicated by the symbol K, in order to avoid interference between the tool holder 2 and the processing surface. Must lengthen the cutting tool 1. Then, in a machining range where a relatively small diameter cutting tool 1 is required, such as for finishing a corner portion, breakage of the cutting tool 1 and deterioration of the machined surface accuracy are likely to occur due to the runout of the cutting tool 1 and the cutting load. A problem arises.

[0008]

Therefore, as shown in FIG. 10, a method of cutting along the tool cutting path K by inclining the tool axis O of the cutting tool 1 with respect to the Z axis of the NC processing machine will be described. Attempts have been made to adopt it.

In this case, however, the interference check range is inevitably increased by the amount of inclination of the tool axis O, which complicates the interference check work.

Further, when the cutting is performed with the tool axis O tilted, as shown in FIG. 11, when the shape surface F ₁ of the shape surface F which requires interference check is taken out as data, the cutting tool is used. 1 (here, for the sake of simplicity, a cylindrical shape), the intersection of a plane including the upper surface 1a and the lower surface 1b and the shape surface F must be obtained while determining based on the NC coordinate system. When performing an interference check with the tool 1, see the interference between the elements 1c, 1c ... (that is, a set of circles) forming the cutting tool 1 (in other words, a cylinder) and the shape surface F ₁ , or A plane P having a vector in the direction of the axis O
On the other hand, it is necessary to compare the distance from the tool axis O to the shape surface F ₁ and the radius of the cutting tool 1. In other words, polar coordinates must be set many times for each element (constituting point) that constitutes the tool cutting path data. Therefore,
As the number of objects to be calculated becomes extremely large, the number of coordinate conversions also becomes large, which causes a problem that it takes a lot of time for the interference check.

The present invention has been made in view of the above points, and when performing die cutting using a cutting tool having a tool axis inclined with respect to the Z axis of an NC processing machine, It is an object of the present invention to make it possible to easily and quickly perform an interference check with a cutting tool.

[0012]

A method of creating a tool cutting path for NC processing according to the present invention is based on shape surface data using a cutting tool having a tool axis inclined at a predetermined angle with respect to the Z axis of an NC processing machine. When creating a tool cutting path for performing cutting by cutting, the shape surface data and the tool cutting path data are rotated by coordinate conversion so that the processing direction is the direction of the Z axis, and then the tool system model and the shape. I try to check the interference with the surface data.

In the NC machining tool cutting path creating apparatus of the present invention, a machining tool having a tool axis inclined by a predetermined angle with respect to the Z axis of the NC machining machine is used to perform machining based on the shape surface data. Is an NC machining tool cutting path creating device for creating a tool cutting path, and an input unit for inputting shape surface data, tool cutting path data, and a machining direction,
A coordinate conversion unit that rotates the shape surface data and the tool cutting path data by coordinate conversion so that the machining direction is the direction of the Z axis, and an interference check for checking the interference between the tool system model and the rotated shape surface data. And a section.

[0014]

In the NC machining tool cutting path creating method and creating apparatus of the present invention, the shape surface data and the tool cutting path data are rotated by coordinate conversion so that the processing direction is the Z-axis direction of the NC processing machine. , After that, because the interference between the tool system model and the shape surface data is checked,
Upper and lower ends of the tool system model (in other words, NC axis Z
Between the maximum value Zmax and the minimum value Zmin), it is sufficient to extract the shape surface data to be checked for interference, and the interference between the extracted shape surface data and the tool system model is based on the radius in the cutting tool data and the shape surface from the Z axis. It can be checked by comparison with the distance to the data.

[0015]

According to the NC machining tool cutting path creating method and apparatus of the present invention, the shape surface data and the tool cutting path data are coordinate-converted so that the machining direction is the Z axis of the NC processing machine. Since the rotation is performed and then the interference between the tool system model and the shape surface data is checked, the interference check is performed between the upper and lower ends of the tool system model (in other words, the maximum value Zmax and the minimum value Zmin on the NC axis Z). It suffices to extract the shape surface data to be processed, and the interference between the shape surface data thus extracted and the tool system model is caused by the radius and tool axis O (in other words, NC axis Z) in the tool system model to the shape surface data. The interference can be checked by comparing with the distance, the amount of calculation and the number of coordinate conversions can be reduced, and the interference check work can be speeded up. Therefore, it is possible to significantly reduce the creation time of the NC machining tool cutting path, which is an excellent effect.

[0016]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

In this embodiment, a tool cutting path for carrying out a cutting process based on the shape surface data is created by using a cutting tool having a tool axis inclined by a predetermined angle with respect to the Z axis of an NC processing machine. Yes, as shown in FIG.
Is detachably attached to the tool head H provided at the tip of the spindle A of the NC processing machine via the tool chuck C in an inclined state with respect to the NC axis Z. The spindle A and the tool head H are rotatable in the directions of arrows M and N, respectively.

Further, the NC machining tool cutting path of this embodiment is created by using a CAD / CAM system, and its basic construction will be described with reference to the block diagram shown in FIG.

The NC machining tool cutting path creating apparatus according to the present embodiment includes an input unit 11, an external storage unit 12, a selection unit 13, a coordinate conversion unit 14, an interference check unit 15, and a result recording unit 1.
6 is provided.

In the input section 11, the shape surface data F and a plurality of tool cutting path data K ₁ , K ₂ ... (See FIG. 3)
And the machining directions Q ₁ , Q ₂ ... Of the respective tool cutting path data K ₁ , K ₂ ... The machining directions Q ₁ , Q _2, ... Are directions when the rotation angle of the spindle A and the rotation angle of the tool head H are fixed at a certain angle.

The external storage unit 12 stores data (dimensions, holder shape, etc.) of the cutting tool used.

In the selecting unit 13, a plurality of tool cutting path data K ₁ , K ₂ ... Is classified into cutting path data groups G ₁ and G ₂ ... (That is, one of the machining directions Q ₁ , Q ₂ ...) Is designated, and the tool cutting path data group G ₁ , G ₂ ... With the designated machining direction Q is coordinate-transformed together with the shape surface data F. Part 1
4 is output.

In the coordinate conversion section 14, the shape surface data F and the tool cutting path data groups G ₁ , G ₂ ... Are arranged so that the machining direction Q designated in the selection section 13 becomes the direction of the NC axis Z. The coordinate plane is rotated (see FIG. 4), and the coordinate plane-converted shape surface data F and tool cutting path data group G are output to the interference check unit 15.

In the interference check unit 15, the interference between the tool system model T, the shape surface data F, and the tool cutting path data K ( _one of K ₁ , K _2, ...) Read out from the external storage unit 12. Check (details will be described later) is performed,
The result is output to the result recording unit 16.

The result recording unit 16 records the result of the interference check (that is, whether or not it interferes, the place of interference, the set tool, etc.), and the next tool cutting is performed on the interference check unit 15 and the selection unit 13. A request for route data and a request for the next interference check processing direction are output.

Next, the creation of the NC machining tool cutting path will be described in detail with reference to the flow chart shown in FIG.

In the following, the CAD / CAM system is used to check the interference in the tool cutting path when a die for an automobile member having shape surface data F as shown in FIG. 3 is cut using an NC processing machine. The case of performing the above will be described as an example. In such shape surface data F,
A plurality of tool cutting path data K ₁ , K ₂ ··· and machining directions Q ₁ , Q ₂ · · whose machining directions are different depending on the location to be machined
・ There exists.

First, in step S ₁ , the input unit 11
To shape surface data F, tool cutting path data K ₁ , K ₂ ...
And the machining directions Q ₁ , Q ₂ ... Of the respective tool cutting path data K ₁ , K ₂ ... Next, the selecting unit 13 classifies the plurality of tool cutting paths K ₁ , K ₂ ··· into cutting path groups G ₁ , G ₂ ··· according to the machining direction (step S ₂ ), and thereafter, machining for which interference check is performed this time. The direction Q (that is, one of the machining directions Q ₁ , Q _2, ...) Is designated (step S ₃ ), and in step S ₄ , the tool cutting path data group (that is, the tool) having the designated machining direction is designated. One of the cutting path data groups G ₁ , G ₂ ... Is taken out together with the shape surface data F.

Thereafter, in the coordinate conversion section 14, the shape surface data F and the tool cutting path data group (for example, the tool cutting path data group so that the designated machining direction Q (in other words, the tool axis O) becomes the direction of the NC axis Z) (for example, G ₁ ) is collectively rotated (step S ₅ ). As shown in FIG. 4, this rotation is performed by rotating the shape surface data F'and the tool cutting path data K'in the state of the chain line in the arrow B direction by coordinate conversion. Then, as shown in FIG. 4, the machining direction Q coincides with the NC axis Z and the tool axis O. Since the main axis A of the NC processing machine is fixed in the processing direction Q here, one of the tool cutting path data groups (that is, one of G ₁ , G ₂ ... ), The rotation base point is collectively performed at the origin of the NC coordinate system.

Next, the data of the cutting tool to be used is retrieved from the external storage unit 12 (step S ₆ ), and one is selected from the tool cutting path data group (tool cutting path data K).
Extraction (step S ₇ ), the interference check unit 15 performs an interference check between the tool system model T and the shape surface data F on the tool cutting path data K (step S ₈ ), and the result storage unit 16 stores the result in a file. Save (step S ₉ ).

This interference check will be described in detail with reference to FIGS. 6 and 7.

That is, the maximum value Zmax of the NC axis Z in the tool system model T (here, for the sake of simplicity, it has a cylindrical shape).
And the intersections a and b of the minimum value Zmin and the shape surface data F,
The points a and b are taken out as the shape surface data F ₁ that requires an interference check, and the radius r and the tool axis O (in other words, NC axis Z) in the tool system model T and the distance d between the shape surface data F are obtained. As a result of comparison, if d> r, it is determined that “interference does not occur”, and if d ≦ r, “interference occurs”. Therefore, for the interference check of the present embodiment, the same method as the conventionally known processing from the NC axis Z direction is adopted.

Then, in step S ₁₀ , it is judged whether or not there is unprocessed tool cutting path data in the cutting path group G including the designated tool cutting path K,
If it is determined that "there" repeats the check of interference between the tool cutting path K unprocessed returns to step S _6. If it is determined as "no" in step S ₁₀ (i.e., the interference check of the tool cutting path data in the cutting path group G is completed), step S ₁₁
In, whether machining direction Q there is an unprocessed determination is made, if it is determined as "Present", the process returns to step S _3, the machining direction Q Step S ₃ following processing for the unprocessed repeat.

As described above, in the present embodiment, the shape surface data F and the tool cutting path data K are rotated by coordinate conversion so that the machining direction becomes the Z axis of the NC machining machine, and then the tool system model T and the geometry. Since the interference with the surface data F is checked, the upper and lower ends of the tool system model T (in other words, the maximum value Zm on the NC axis Z).
It is sufficient to extract the shape surface data F ₁ to be subjected to the interference check between ax and the minimum value Zmin), and the interference between the extracted shape surface data F ₁ and the tool system model T is the radius r in the cutting tool system model T. Tool axis O (in other words,
Interference can be checked by comparing with the distance d from the NC axis Z) to the shape surface data F ₁ . Therefore, the amount of calculation and the number of coordinate conversions can be reduced, and the interference check work can be speeded up.

In the above description, a plurality of tool cutting path data having different machining directions are present in the shape surface data F, and these tool cutting path data are classified into cutting path groups for each machining direction. It goes without saying that the present invention can be applied to those having only tool cutting paths having the same machining direction.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of an apparatus used in a method for creating a NC machining tool cutting path according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a spindle tip portion in an NC processing machine to which a method for creating a tool cutting path for NC processing according to an embodiment of the present invention is applied.

FIG. 3 is a diagram showing an example of shape surface data and tool cutting path data to which a method for creating an NC machining tool cutting path according to an embodiment of the present invention is applied.

FIG. 4 is an explanatory diagram for explaining a state of rotation in the method for creating the NC machining tool cutting path according to the embodiment of the present invention.

FIG. 5 is a flowchart illustrating an interference check procedure in the method for creating the NC machining tool cutting path according to the embodiment of the present invention.

FIG. 6 is an explanatory diagram for explaining extraction of interference check shape surface data during interference check in the NC machining tool cutting path creation method according to the embodiment of the present invention.

FIG. 7 is an explanatory diagram for explaining an aspect of interference check in the method for creating the NC machining tool cutting path according to the embodiment of the present invention.

FIG. 8 is a perspective image diagram for explaining an NC processing state by a conventionally known method.

FIG. 9 is a side image view for explaining an NC processing state by a conventionally known method.

FIG. 10 is a side view image diagram for explaining an NC machining state when the tool axis is tilted with respect to the NC axis.

FIG. 11 is an explanatory diagram showing a mode of interference check when the tool axis is tilted with respect to the NC axis.

[Explanation of symbols]

1 is a cutting tool, 2 is a tool holder, 11 is an input section, 12
Is an external storage unit, 13 is a selection unit, 14 is a coordinate conversion unit, 15
Is an interference check unit, 16 is a result recording unit, F is a shape surface data, F ₁ is a shape surface data requiring an interference check, K is a tool cutting path data, O is a tool axis, Q is a machining direction, and T is a tool system model. , Z is the NC axis.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shuhei Fukuda 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Motor Corporation

Claims (2)

[Claims] 1. A tool cutting path for performing a cutting process based on shape surface data using a cutting tool having a tool axis inclined by a predetermined angle with respect to the Z axis of an NC processing machine.
A method for creating a C machining tool cutting path, wherein the shape surface data and the tool cutting path data are rotated by coordinate conversion so that the machining direction is the direction of the Z axis,
Then, a method of creating a tool cutting path for NC machining is characterized by checking the interference between the tool system model and the shape surface data. 2. A tool cutting path for performing a cutting process based on shape surface data using a cutting tool having a tool axis tilted at a predetermined angle with respect to the Z axis of an NC processing machine N
An apparatus for creating a tool cutting path for machining, comprising: an input unit for inputting shape surface data, tool cutting path data, and a processing direction; and a processing direction for the shape surface data and the tool cutting path data is a direction of the Z axis. The tool cutting path for NC machining is characterized by comprising a coordinate conversion unit for rotating by coordinate conversion so that the interference check unit for checking the interference between the tool system model and the rotated shape surface data. apparatus.