JPH08305427A - Preparing method for surface working data for five-axes working machine - Google Patents

Abstract

PURPOSE: To prepare surface machining data for preventing the occurrence of overcut in the case of shifting a machining curved surface from one curved surface to the other curved surface when a work machining surface composed of plural curved surfaces is machined by using a five-axes machining center. CONSTITUTION: On a work machining surface 51, a ruled surface SR is linked within a certain range where the machining surface 51 and a rotary tool are not interferred and along the ruled surface SR, the side blade or bottom blade of the rotary tool is virtually moved so that surface machining data for machining the work machining surface 51 can be prepared. Since the rotary tool moved on the ruled surface SR, the motion of the rotary tool is made smooth, and even in the case of shifting the machining surface from one curved surface Sf10 on the work machining surface 51 to another curved surface Sf9, the attitude (inclination) of the rotary tool is not rapidly changed. Thus, the rotary tool is not affected by the rapid change of load received from a work and the occurrence of interference, namely, so-called overcut can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a numerically controlled machine tool having a 5-axis machined surface of a work having a free curvature such as a press die for press-molding an outer plate (side panel outer) of an automobile. (Hereinafter also referred to as NC machine tool) 5-axis machining for cutting or grinding while avoiding interference with a tool having cutting edges on the outer circumference (side peripheral surface) and end surface (bottom surface) mounted on a 5-axis NC machining center The present invention relates to a method of creating machined surface processing data.

[0002]

2. Description of the Related Art FIG. 1 shows a 5-axis N which is also applied to the present invention.
The general structure of the part including the head 11 of the C machine tool is shown. The head 11 is attached to a transfer shaft 12 movably attached to a 5-axis NC machine tool body (not shown). This transfer shaft 12 has three orthogonal axes X,
Motors for the Y and Z axes (not shown) are used to transport the respective components in the X axis, Y axis, and Z axis directions through the feed mechanism.

A substantially triangular prism-shaped first rotating member 13 having a predetermined flat inclined surface 13a is rotated about a C-axis parallel to the Z-axis by a C-axis.
The shaft motor 15 can turn in the direction of arrow α. Also, an inclined surface 14 that is in sliding contact with the inclined surface 13a.
a, and θ ° with respect to the C-axis, for example, 50
The second rotating member 14 having the arm portion 14c extending in the direction inclined by φ °, for example, 10 ° with respect to the inclined B axis.
However, the B-axis motor 16 can turn around the B-axis in the arrow β direction. The second rotating member 14
Is a flange portion 14b having the inclined surface 14a and an arm portion 1 integrally manufactured with the flange portion 14b.
4c and a chuck fixing portion 14d fixed to one end of the arm portion 14c.

Chuck fixing part 1 in the second rotating member 14
The chuck 17 is integrally fixed to 4d. At one end of the chuck 17, a rotary machining tool 1 (sometimes referred to as a flat cutter) such as an end mill having a cutting edge on the side surface and a bottom surface (referred to as side blade 1s and bottom blade 1t, respectively) is attached. To be The tool 1 is configured to be capable of rotating at high speed in the arrow γ direction or the opposite direction, for example, at a speed of about 10,000 rpm or more by a tool motor (not shown). Note that the tool 1 has an arrow γ
The tool 1 looks like a cylinder when it is rotating in the opposite direction. That is, the tool 1 can cut or grind a work by using the side blades 1s and the bottom blade 1t in a portion that looks like a cylinder.

Then, under such a structure, the tool 1
Is moved in the X, Y, and Z directions through the transfer shaft 12, swung around the C axis by the first rotating member 13 rotated by the C axis motor 15, and is rotated by the B axis motor 16. The rotating member 14 of FIG. As described above, the 5-axis NC machine tool can be said to be a machine having three orthogonal axes X, Y, Z and two axes B, C that rotate.

Tool trajectory data of this 5-axis NC machine tool,
The so-called CL data includes the XYZ coordinates (x, y, z) of the tip 1b of the tool 1 and the tilt angle (AX, B) of the axis 1a of the tool 1.
X) (AX and BX will be described later). In this case, as shown in FIG. 2, the tilt angle is represented by a tilt angle AY when the axis of the tool 1 is viewed from the YZ plane and a tilt angle AX when viewed from the XZ plane. Note that FIG.
Among them, reference numerals 1ax and 1ay indicate the projection of the axis 1a of the tool 1 on the XZ plane and the projection on the YZ plane, respectively.

Therefore, when the tool locus data of the 5-axis NC machine tool is represented by P, P is P = P (x, y, z, A
It is represented by a set of 5-axis NC data (X, AY).

By using a 5-axis NC machine tool constructed as shown in FIG. 1, a work can be cut or ground into a relatively free curved surface shape.

[0009]

By the way, in the case of a work formed by a plurality of curved surfaces, when the tool 1 moves from one curved surface to another curved surface, the direction of the axis 1a of the tool 1,
That is, the tilt angle changes abruptly.

However, when the tilt angle axis direction of the tool 1 changes abruptly, the load on the tool 1 changes abruptly,
Due to this, the tool 1 is shaken and the like.
There is a problem that interference (overcut) with respect to the work, so-called shaving, is likely to occur.

When the work in which the shaving is generated is a die such as a press, the correction work takes a considerable amount of time, and even if the work is corrected, the strength of the die becomes weak at the corrected portion. There are some secondary problems.

Moreover, when the direction of the tilt angle axis of the tool 1 changes abruptly, a sharp load is applied to the tool 1 when the tool 1 comes into contact with a workpiece, and the tool 1 may break. There was also the problem of being there.

Furthermore, even during machining of one curved surface, the inclination of the tool 1 is frequently changed along the shape of the curved surface, which causes a large amount of tool loci remaining on the work, and as a result, There was also a problem that a lot of uncut material would occur.

The present invention has been made in consideration of such a problem, and it is possible to prevent interference of the tool with the work when processing the work surface by the side blade or the bottom blade of the rotary tool. It is an object of the present invention to provide a method for creating surface processing data for a 5-axis machine.

[0015]

SUMMARY OF THE INVENTION The present invention creates surface machining data for machining a work surface composed of a plurality of curved surfaces by a rotary tool mounted on a 5-axis machine and having a side blade and a bottom blade. In the method, a ruled surface is stretched on the workpiece machining surface in a range that does not interfere with the rotary tool, and a machining path is virtually moved along the ruled surface by moving side blades or bottom blades of the rotary tool. It is characterized in that it is created and the data corresponding to this machining path is used as the surface machining data.

Further, according to the present invention, the work surface is
Substantially, a center curve, two outer curves arranged corresponding to the center curve, and a plurality of curved surfaces stretched between the center curve and each of the two outer curves. In the above case, the ruled surface is stretched on each of the two outer curved sides with the central curve as a ridge line, and the machining path connects the bottom blade and the side blade of the rotary tool. One point on the circumference is defined as a path which moves from the machining start point to the machining end point along the central curve.

Further, according to the present invention, when the ruled surface is stretched, an orthogonal plane in which the central curve is a normal line is created at the processing start point, and the two outer curves on the orthogonal plane are formed. Of each of the intersecting points, each straight line connecting the machining starting point and each of the intersecting points, each cutting line in each curved surface connecting the machining starting point and each of the intersecting points, the machining starting point and each of the When each straight line connecting the intersection point does not intersect with each cut line of each curved surface on the orthogonal plane, it is determined that the work machining surface and the rotary tool do not interfere with each other, and when intersecting, Is determined to be a straight line where the work machining surface and the rotary tool interfere with each other, and when it is determined that there is interference, a straight line connecting the machining start point and the intersection is used as a fulcrum with the machining start point as a fulcrum. Orthogonal to the direction away from the contents Rotate to a position in contact with each cut line on the surface to make a straight line that avoids interference, repeat the procedure from creating the orthogonal plane to determining and avoiding the interference until the processing end point, each processing point The surface stretched between the straight line which does not interfere with the above and the straight line which avoids the interference is the ruled surface.

[0018]

According to the present invention, a line-woven surface is stretched on a work-working surface composed of a plurality of curved surfaces to the extent that the work-working surface and the rotary tool do not interfere with each other, and the rotary tool is extended along the line-woven surface. By virtually moving the side blades or the bottom blade, surface processing data for processing the workpiece processing surface is created. In this case, since the rotary tool moves on the ruled surface, the motion of the rotary tool becomes smooth.

Further, according to the present invention, in the case where the work machining surface is substantially defined by a plurality of curved surfaces stretched between the central curve and each of the two outer curves, the rotary tool When you try to machine a workpiece machining surface by moving one point on the circumference where the bottom and side blades of are connected along the central curve from the machining start point to the machining end point, the central curve is ridged. In order not to interfere with each curved surface stretched, the ruled surface is stretched in the direction away from the work surface of each curved surface. Even in this case, since the rotary tool moves on the ruled surface, the motion of the rotary tool becomes smooth.

Further, according to the present invention, an orthogonal plane in which the central curve is the normal line at the machining start point is created, each intersection with the two outer curves on the orthogonal plane is obtained, and the machining start point and each Obtain each straight line that connects the intersection and each cut line of each curved surface that connects the processing start point and each cross point, and if each straight line does not intersect each cut line, determine that it is a straight line that does not interfere and intersect. In this case, it is determined that the line is an interfering line, and when it is determined that the line is interfering, the line is rotated from the machining start point as a fulcrum to a position in contact with each cut line on an orthogonal plane in a direction away from the work surface. By repeating the procedure until changing to a straight line that avoids interference, from the machining start point to the machining end point, the surface between the straight line that does not interfere and the straight line that avoids interference at each machining point By side blade It is a ruled surface to be made. Thereby, the ruled surface can be easily created.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In the drawings referred to below,
Components corresponding to those shown in FIGS. 1 and 2 are designated by the same reference numerals, and detailed description thereof will be omitted. Since FIGS. 1 and 2 are also used in the embodiment of the present invention, these are also referred to.

FIG. 3 shows that the rotary tool 1 (see FIG. 1; hereinafter, also simply referred to as a tool) does not interfere with a work surface formed by a plurality of curved surfaces, and efficiently processes the work surface. Tool locus data (so-called CL data)
The NC data creation system 21 for creating the 5-axis NC data (surface processing data) D2 is shown.

This NC data creation system 21 is an NC
It has a data creation unit 22. NC data creation unit 22
Is supplied from the database 24 with surface model data D1 corresponding to a work surface of a press die or the like which has been created in advance by another CAD system for the work surface of the work. It should be noted that the surface model data D1 in this case also includes information on which side of the surface the content is. Here, the work is the contents,
For example, in the case of a press die, it means the side left as the press die.

The NC data creation unit 22 is also supplied with tool data Td representing the attributes of the tool 1 from the database 23. The attribute of the tool 1 is a tool name (in this embodiment, an end mill having a side blade 1s and a bottom blade 1t) and a parameter of the tool 1, that is, a tool diameter (in the case of an end mill, a bottom). It corresponds to the diameter of the blade portion, that is, the cutting blade length of the bottom blade portion), the cutting blade length of the side blade portion, the tool shape, and the like.

The NC data creating section 22 determines, based on the obtained tool data Td and surface model data D1.
5-axis NC data D2 is created such that a work (not shown) has a shape surface represented by the surface model data D1.

The 5-axis NC data D2 to be created is
The shape represented by the surface model data D1 of the present invention, that is, the work machining surface (also referred to as the work machining shape surface) is a free-form surface, as will be described later in an example. Therefore, the shape represented by the surface model data D1. To
It is preferable that the data is efficient in finally cutting out from the work, in other words, the data can be cut as much as possible at a time and the finishing work to be performed later including the manual work is easy. Of course, when the workpiece machining surface is machined by the head 11 (see FIG. 1) of the 5-axis NC machine tool based on the created 5-axis NC data D2, the tool 1 and the workpiece machining surface do not interfere (overcut), that is, so-called. It is a prerequisite for creating the 5-axis NC data D2 that it can be cut without being cut.

In order to realize these, the shape data of the portion including the head 11 of the 5-axis NC machine tool is stored in the NC data creating unit 22 in advance. The portion including the head 11 interferes with the work surface. Not 5-axis NC data D
2 is created, but in the following description, creation of surface processing data that avoids interference in the part of the tool 1 will be described, and description of interference avoidance in the part including the head 11 excluding the tool 1 will be described. Since it is complicated and not directly related to the present invention, it is omitted.

The 5-axis NC data D2 created as a result by the NC data creating unit 22 is tool locus data as described above. In the case of the tool 1, the tool locus data of the tool 1 is the inclination data of the tool 1. It is a set of three-dimensional position coordinate data of the center 1c of the bottom edge 1t of the tool 1 including the five-axis NC data.

The databases 23, 24 and 26 are
Each of them is a storage means such as a hard disk, and the configuration may be such that one storage means is shared.

The NC data creating section 22 is a computer, and as is well known, a central processing unit (CPU).
And an I / O port connected to the central processing unit, a read-only memory (ROM) in which system programs and the like are written, and a random access memory (RAM, which is a write / read memory) for temporarily storing processing data, etc. , An external memory in which an application program such as a 5-axis NC data creation program and a graphic processing program for creating the optimum 5-axis NC data D2 that does not interfere with the work, a tablet 32 for a digitizer, a mouse Input device such as 34, keyboard 33 and volume switch 35, display 3
1. It has an output device such as a plotter printer not shown.

Next, the operation of the above embodiment will be described with reference to the flowchart relating to the data creating program shown in FIG. Unless otherwise specified, the control subject is the NC data creating unit 22. Further, the tool 1 is an end mill having a cutting edge on the bottom surface and the side peripheral surface as described above. For example, the number of blades is a straight blade having two or more blades or a twisting blade, and the axial direction including the bottom surface. A so-called square tool with a rectangular cross section (also called a flat cutter)
To use.

Therefore, first, the NC data creation unit 22
The tool data Td is read from the database 23, and the surface model data D1 is read from the database 24.
Is read (step S21). The surface model data D1 is graphic information of the workpiece machining surface that is created in advance by the CAD system on the upstream side.

As is well known, the surface model data D
1 consists of wire frame data and surface data. That is, the surface model data D1 is composed of a plurality of curve (which includes straight lines here) data which is wireframe data, and curved surface data which represents a plurality of curved surfaces stretched between the curves. Become.

FIG. 5 shows a work surface 51 which is a free-form surface represented by the read surface model data D1. The work machining surface 51 basically has a central curve Cv1, two outer curves Cv2 and Cv3 arranged corresponding to the central curve Cv1, and substantially a central curve Cv1. It is composed of eleven curved surfaces Sf1 to Sf11 stretched between the outer two curves Cv2 and Cv3. In FIG. 5, reference numeral 48 indicates a step at the connecting portion between the curved surface Sf8 and the curved surface Sf5, which appears due to the curved surface Sf5 falling to the back side of the paper surface.

For the sake of convenience, the three curved surfaces Sf1 to Sf3 existing between the curved line Cv1 and the curved line Cv2 on the work surface 51 are collectively referred to as a left curved face SfL, which is between the curved line Cv1 and the curved line Cv2. 8 existing curved surfaces Sf
4 to Sf11 are referred to as right curved surface Sfr. When defined in this way, the workpiece machining surface 51 is considered to be composed of the left curved surface SfL and the right curved surface Sfr, and the curve Cv
1 can be considered to be a ridgeline of the left curved surface SfL and the right curved surface Sfr. Further, it is considered that the content of the work related to the work processing surface 51 is on the back side of the paper surface in FIG.

Each of the curved surfaces Sf1 to Sf11 is a so-called trim curved surface obtained by cutting out a part from, for example, 11 original curved surfaces (referred to as a base curved surface) which are not shown and are basic. Dotted lines drawn for reference in the vertical and horizontal directions in the curved surfaces Sf1 to Sf11 are so-called parameter lines showing features such as curvatures of the curved surfaces Sf1 to Sf11. Conventionally, since the contact point of the tool 1 is determined based on this parameter line, for example, the curved surface Sf10 and the curved surface S
At the connecting portion 49 of f9, a sharp change in the posture (inclination) of the tool 1 occurs, and the load of the tool 1 increases, causing the tool 1 to shake (remain oscillated), and based on the shake. Interference (overcut), so-called shaving, often occurred.

Next, the tool parameters of the tool 1 for machining the work surface 51 are set or determined (step S2).

The lower right diagram in FIG. 1 is used for explaining the definition of the tool parameter in this embodiment of the tool 1, and the tool parameter of the tool 1 is the cutting edge length of the side blade 1s portion. From a side blade parameter (also referred to as a tool parameter or a tool side blade parameter) Py indicating the depth and a bottom blade parameter (also referred to as a tool parameter or tool bottom blade parameter) Px indicating the cutting edge length of the bottom blade 1t portion. Become.
The bottom blade parameter Px is equal to the diameter of the tool 1. In addition,
In the figure, the symbol Cf represents the circumference that is a ridge line connecting the bottom blade 1t and the side blade 1s, which appears when the tool 1 is rotating. Further, in the figure, the side blade parameter Py and the bottom blade parameter Px indicate the maximum length, and it is possible to set the tool parameter by limiting the length to an appropriate length within this maximum length.

When machining the workpiece machining surface 51, in this embodiment, one point on the circumference Cf of the rotating tool 1 (one point when the tool 1 is rotating) is the central curve C.
Machining start point P01 in contact with v1 (see Fig. 5)
From the machining end point Pn1 to the machining end point Pn1. The movement scanning performed twice is the first movement scanning, and the inclination of the tool 1 is inclined to the right curved surface Sfr side in the maximum range in which the tool 1 does not overcut the right curved surface Sfr, and the side blade 1s is used for machining (this processing scanning The inclination of the tool 1 can be gradually changed.) In the second movement scan, the tool 1 is tilted to the left curved surface SfL side to the maximum extent within the range where the tool 1 does not overcut the left curved surface SfL, and the side blade 1s is used. This is for machining (the inclination of the tool 1 can be changed even during this machining).

In this embodiment, after all, two tool locus data corresponding to these two machining scans are created. However, as will be described below, these two tool locus data substantially correspond to each other. Can be created at the same time.

Therefore, the position on the central curve Cv1 at which one point of the circumference Cf of the tool 1 abuts is represented by a parameter i on the software, and the position parameter i is first i = 0.
(The unit is a unit of length, for example, mm.) (Step S3). Here, the central curve Cv1
The arbitrary processing point above is represented by Pi1. Therefore, when the position parameter i = 0 is set, the machining point Pi1 becomes Pi.
1 = P01, and the processing start point P01 is specified.

Then, next, the position indicated by the position parameter i from the machining start point P01 on the central curve Cv1. In this case, since the position parameter i is i = 0, the machining start point P01 is shown in FIG. So that the central curve Cv
An orthogonal plane Op0 (generally represented by Opi) in which the tangent line of 1 is the normal line nv is created (step S4).

Next, the orthogonal plane Opi (in this case, Opi =
Op0) and the intersection points Pi2 of the outer curves Cv2 and Cv3
(In this case, Pi2 = P02) and intersection Pi3 (in this case, Pi3 = P03) are obtained (step S5).

Next, the processing point Pi1 and the intersection points Pi2, Pi
A straight line Li1 that connects 3 and 3 respectively (in this case, Li1 = L
01 (see FIG. 7)} and a straight line Li2 {in this case, Li2 =
L02 (see also FIG. 7)} (step S
6).

FIG. 7 shows a normal direction NLi of the orthogonal plane Opi = Op0 ((in this case, NLi = NL0 (see FIG. 6))).
In other words, the straight line Li1 and the straight line Li2 viewed from the direction perpendicular to the orthogonal plane Opi are shown.

In order to avoid complication, the position parameter i is generally described as i = i in the following description, and if necessary, the actual value of the position parameter i, for example, i = i It will be described as 0.

Then, next, when it is considered that the orthogonal plane Opi cuts the left curved surface SfL and the right curved surface Sfr, the cut line Mi1 of the left curved surface SfL (see FIG. 8) and the cut line Mi2 of the right curved surface Sfr. (Similarly, refer to FIG. 8) is obtained (step S7). In this case, the cut line Mi1
Is a ridgeline formed by the intersection of the orthogonal plane Opi and the curved surface Sf3. Similarly, the cut line Mi2 is the orthogonal plane Opi.
Is a ridgeline formed by the intersection of the curved surfaces Sf10 and Sf11 (see FIG. 6).

FIG. 8 shows the normal direction NLi of the orthogonal plane Opi.
It is the figure which drew the cut lines Mi1 and Mi2 seen from above. In FIG. 8, the hatched side indicates the content side 54 of the work processing surface 51 (referred to as the work processing surface content side 54, the processing surface content side 54, or the content side 54). In addition, the machining surface side of the workpiece machining surface 51 is denoted by reference numeral 55.
(It is referred to as the work processing surface side 55 or the processing surface side 55.)
It is represented by.

In the process of step S5, the intersection point Pi2 between the orthogonal plane Opi and the outer curves Cv2 and Cv3 is set.
When the intersection point Pi3 is not obtained, specifically, in FIG. 6, the end points 52 and 53 of the curves Cv2 and Cv3 on the outer side as viewed from the tangential direction TL0 of the orthogonal plane Op0 are closer to each other than the orthogonal plane Op0 in the figure. If it is on the left back side, the straight lines Li1 and Li2 and the cut lines Mi1 and Mi2 cannot be obtained. In such a case, the curved surface Sf3,
The end faces of Sf10 and Sf11 on the orthogonal plane Op0 side (see FIG. 6).
Inside, a side of a curved surface Sf3 connecting the processing start point P01 and the end point 52, and a curved surface S connecting the processing start point P01 and the end point 53.
The side of f10 and Sf11) may be virtually extended to the position where it abuts the orthogonal plane Op0 in the tangential direction of the end face while keeping the shape of the end face. Here, extending the shape of the end surface as it is means extending the shape of the end surface of the curved surfaces Sf3, Sf10, and Sf11 as viewed from the perpendicular direction NL0 of the orthogonal plane Op0. By doing so, it becomes possible to virtually create the intersection points P03 and P02, and as will be understood later, the tool trajectory data is created from the machining start point P01 to avoid the interference between the tool 1 and the workpiece machining surface 51. It is possible to create a ruled surface (which will be described later in detail) which is basic data for doing.

Next, referring to FIGS. 7 and 8, the straight line Li1
And the cutting line Mi1 and the positional relationship between the straight line Li2 and the cutting line Mi2 are determined to determine whether or not there is interference between the tool 1 and the workpiece machining surface 51 (step S8).

FIG. 9 is a diagram in which the cut lines Mi1 and Mi2 are drawn on the straight lines Li1 and Li2 in order to determine the positional relationship. The determination of the positional relationship here is, after all, a determination of whether or not the straight lines Li1 and Li2 are on the work processing surface content side 54. In FIG. 9, a part of the straight line Li2 is
The right side of the cut line Mi2 in the figure, that is, the processing surface content side 5
4, the side edge 1s of the tool 1, for example, the straight line Li
When the number is matched with 2, the determination is established because the hatched portion becomes the interference portion (overcut portion) OC. As shown in FIG. 9, when only part of the straight line Li2 is on the processed surface content side 54, the straight line Li2
Is determined to be on the processed surface content side 54. On the other hand, the straight line L
It is determined that i1 exists on the left side of the cut line Mi1, that is, on the processing surface side 55.

10A to 10E are diagrams for explaining various positional relationship determinations between the straight line Li2 and the cut line Mi2, and in the case of FIG. 10A, the straight line Li2 and the cut line Mi2.
2 and the straight line Li2 are 55 on the processed surface side.
Therefore, the interference portion OC does not exist. Figure 10
In the case of B as well, the straight line Li2 is naturally on the processed surface side 55, and there is no interference portion OC. In the case of FIGS. 10C to 10E, since at least a part of the straight line Li2 is on the processed surface content side 54, the interference part OC exists.

When the positional relationship determination in step S8 is established, that is, when it is determined that there is the interference portion OC, the straight lines Li1 and Li2 are on the orthogonal plane Opi, and the machining point Pi1 is the starting point on the machining surface side 55. It is tilted to a position where the interference portion OC disappears (step S9).

When the positional relationship determination in step S8 is established, the tilted straight lines Li1 'and Li2' (both see FIGS. 11A to 11E) are matched with, for example, the tool parameter Py, and the position in step S8 is determined. When the relation determination is not established, the interference portion OC does not exist, and thus the obtained straight lines Li1 and Li2 are directly used as the tool parameter P.
Match y (step S10).

11A to 11E are the same as FIGS. 10A to 10E.
Corresponding to each case of E, the tool parameter Py of the side blade 1s set in step S10 (here, Pyi1
far. 3] is a diagram provided for explaining the setting of FIG.

In the case of FIGS. 11A and 11B, the tool parameter Pyi1 of the tool 1 is set so as to match the straight line Li2. That is, the tool parameter Pyi1
Is an intersection point Pi3 which is an end point of the processing point Pi1 and the straight line Li2.
Of the corresponding point Pi3 '(in this case, Pi3' = Pi3).

In FIGS. 11C to 11E, the straight line Li2 is tilted toward the working surface side 55 from the working point Pi1 as the starting point, and the straight line Li
The tool parameter Pyi1 of the tool 1 is set to the corresponding point Pi3 'of the intersection point Pi3 that is tilted immediately after 2 is separated from the cut line Mi2, in other words, is tilted so as not to interfere. The inclination angles in this case are assumed to be ψ1 to ψ3, respectively.

In the case of FIGS. 11A and 11B, both end points of the cut line Mi2 are given priority, and in the cases of FIGS. 11C to 11E, the tangential direction of the cut line Mi2 is given priority and the tilt angle is set. You can also think of it.

Similarly, with respect to the cut line Mi1 on the left curved surface SfL side created in step S7, steps S8 to S8.
By the process of S10, the tool parameter Pyi1 of the tool 1,
Alternatively, the tool parameter Pxi1 (see FIG. 12B) has a corresponding point Pi2 ′ (FIG. 12B, corresponding to the machining point Pi1 and the intersection point Pi2).
(See FIG. 12C).

That is, as shown in FIG. 12A, the part of the side edge 1s of the tool 1 is set as the tool parameter Pyi1 on the side of the cut line Mi2, and as shown in FIG. 12B, on the side of the cut line Mi1. On the other hand, the bottom blade of the tool 1t
The portion is set as the tool parameter Pxi1, and further, as shown in FIG. 12C, the side blade 1s portion of the tool 1 is set as the tool parameter Pyi1 ′ with respect to the cut line Mi1 side. Note that the size of the tool 1 is appropriately drawn in FIGS. 12A to 12C.

In the process of steps S4 to S10, the right curved surface S of the tool 1 at the machining start point P01.
The tool parameter Py01 on the fr side and the tool parameter on the left curved surface SfL, for example, the tool parameter Py01 'were obtained.

Therefore, in order to obtain the tool parameters Pyi1 and Pyi1 'at all machining points Pi1 from the machining start point P01 to the machining end point Pn1, it is confirmed whether or not the value of the position parameter i is i = n. (Step S11).

In this case, since only the tool parameters Py01 and Py01 'at the machining start point P01 are obtained, the position parameter i is set to i = i + 1 (step S12). "+1" represents, for example, a unit length of 0.1 mm, 1 mm, 1 cm, or the like.

Then, returning to step S4, the position i = 0
The process of obtaining the orthogonal plane OP1 at + 1 = 1 and the process of obtaining the tool parameters Py11 and Py11 ′ in step S10 are repeated. In this way, steps S4 to S1 are performed until the positional parameter i becomes i = n.
By repeating the process of 0, the tool parameters Pyi1 and Pyi at all the machining points Pi1 up to the machining end point Pn1.
Find 1 '.

FIG. 13 is a diagram schematically illustrating orthogonal planes OP0 to OPn generated with respect to the work surface 51.

FIG. 14 schematically shows tool parameters Py01 to Pyn1 on the right-hand curved surface Sfr side and tool parameters Py01 'to Pyn1' on the left-hand curved surface SfL side created for the center curve Cv1 of the work surface 51. I am drawing. The position of the tool 1 is schematically indicated by a two-dot chain line for some of the tool parameters Py01 to Pyn1.

Next, by spline interpolation (free curve interpolation), the above-mentioned corresponding point Py0 on the tool parameter Pyi1.
3 ', Py13' to Pyn3 'are sequentially connected, and the corresponding point Py0 on the tool parameter Py1' is connected.
2 ′, Py12 ′ to Pyn2 ′ are sequentially connected to obtain connection curves Cv5 and Cv6 (see FIG. 15), and position data on the connection curves Cv5 and Cv6 are obtained (step S13).

Next, as shown by the hatched portion in FIG. 16, between the curve Cv1 and the connection curve Cv5, the tool parameter Pyi1 which is a straight line is Py01 → Py11 → ... →
A ruled surface (ruled surface (rule) that can be created by moving with Pyn1
d surface): a curved surface formed by the movement of one straight line} SR is set, and a curve Cv1 and a connection curve Cv6
Between the tool parameter Pyi1 ′ and Py01 ′ → P
A line-woven surface SL formed by moving y11 ′ → ... → Pyn1 ′ is stretched.

FIG. 17 shows the work surface 51 shown in FIG.
The ruled surface SR, SL stretched on the front side when viewed from the tool 1 above
FIG.

Next, 5-axis NC data D2 is created from the data representing the ruled surfaces SR and SL (step S15). In this case, since the 5-axis NC data D2 is tool locus data, the ruled surface S from the ruled surfaces SR and SL to the processing surface 55
It can be created as data that is translated in the direction perpendicular to the planes of R and SL by the radius of the diameter of the tool 1 and shifted.

Storage means such as a floppy disk in which the 5-axis NC data D2 created in this way is stored is attached to an NC control unit constituting a 5-axis machine such as a 5-axis NC machining center (not shown), Under the control of this NC control device, the work surface 51 is machined (formed) by the tool 1 mounted on the 5-axis NC machine tool.

As described above, according to the above-described embodiment, when the tool locus for machining the workpiece machining surface 51 is created,
Recognizing the machining shape of the workpiece machining surface 51, determining the machining site of the tool 1, for example, the side blade 1s or the bottom blade 1t, and then
When the interference between the machining shape and the tool 1 is determined, and when it is determined that the tool 1 interferes, the inclination of the tool 1 is changed, and finally, along the inclination of the tool 1, a line corresponding to each of the right curved surface Sfr and the left curved surface SfL is formed. The woven surfaces SR and SL are stretched. Therefore, by machining the workpiece machining surface 51 with the 5-axis NC data D2, which is the tool trajectory data created from the data relating to these two ruled surfaces SR and SL, for example, the side edge 1s of the tool 1 forms a line. Since it moves along the textured surfaces SR and SL, since the surfaces of the linear textured surfaces SR and SL are smooth, the movement of the tool 1 is also smoothed.
Even in the connection portion 49 between the curved surface Sf9 and the curved surface Sf9, the posture (inclination) of the tool 1 does not suddenly change.

As a result, the sudden change in the load of the tool 1 is eliminated, and the occurrence of runout of the tool 1 due to this is eliminated, so there is no possibility of interference (overcut) due to runout, so-called shaving. The remarkable effect of is achieved.

In FIG. 17, the dotted line indicates the parameter line of the workpiece machining surface 51 as described above,
It can be considered that the parameter lines on the ruled surfaces SR and SL are more uniform than the parameter lines on the work surface 51.

The present invention is not limited to the above embodiment,
It goes without saying that various configurations can be adopted without departing from the gist of the present invention.

[0076]

As described above, according to the present invention, a line-woven surface is stretched on a work-working surface composed of a plurality of curved surfaces to the extent that the work-working surface and the rotary tool do not interfere with each other. By virtually moving the side edge or the bottom edge of the rotary tool along the textured surface, surface processing data for processing the workpiece processing surface is created. As a result, the rotary tool moves on a smooth ruled surface, so the movement of the rotary tool also becomes smoother, and the rotary tool also rotates when moving from one curved surface to another curved surface on the workpiece machining surface. The effect that there is no sudden change in the attitude (tilt) of the tool is achieved.

Therefore, it is possible to prevent a sudden change in the load applied to the rotary tool from the work due to a sudden change in posture,
The effect that the rotary tool is not shaken and interference with the work, that is, so-called shaving can be prevented is achieved.

Further, since the rotary tool moves on the ruled surface, the tool is compared with the conventional technique for machining while continuously changing the posture (inclination) along the parameter line on the curved surface. It is possible to reduce the occurrence of uncut residue due to the marks, and it is possible to achieve a secondary effect that the number of man-hours in the manual finishing step after machining by the 5-axis machining machine can be considerably reduced.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration of a head portion of a general 5-axis NC machine tool.

FIG. 2 is a diagram provided for explaining a tilt angle of a tool.

FIG. 3 is a block diagram showing a configuration of a 5-axis NC data creation system according to an embodiment of the present invention.

FIG. 4 is a flowchart showing a process performed by an NC data creating unit in FIG.

FIG. 5 is a diagram showing a work surface which is a free-form surface represented by surface model data.

FIG. 6 is a diagram provided for explaining an orthogonal plane created at a processing start point with respect to a workpiece processing surface.

FIG. 7 is a view of a straight line connecting an intersection point of a work processing start point and an end point of a work processing surface on an orthogonal plane as seen from a direction normal to the orthogonal plane.

FIG. 8 is a view of a cut line of a workpiece processing surface on an orthogonal plane viewed from a direction normal to the orthogonal plane.

9 is a diagram in which the straight line of FIG. 7 and the cut line of FIG. 8 are drawn in an overlapping manner.

FIG. 10 is a diagram which is used for explaining a positional relationship determination between a straight line and a cut line, FIG. 10A is a diagram showing a case where the straight line and the cut line match, and FIG. 10B is a straight line cut line. FIGS. 10C to 10E are diagrams showing a case outside the line, and FIGS. 10C to 10E are diagrams showing a case where a part or all of the cut line is outside the straight line and the tool and the work interfere with each other.

11A to 11E are diagrams of FIGS. 10A to 10E.
It is a figure with which the description for deciding a tool position is provided corresponding to each case of.

FIG. 12 is a view for generally explaining a tool position without interference, FIG. 12A shows a case where one side is processed by a side edge of the tool, and FIG. 12B shows the other side. FIG. 12C is a diagram showing a case of machining with the bottom blade of the tool, and FIG. 12C is a diagram showing a case of machining the other surface with the side blade of the tool.

FIG. 13 is a diagram schematically illustrating a plurality of orthogonal planes generated with respect to a work surface.

FIG. 14 is a diagram schematically illustrating a tool parameter on the right-side curved surface side and a tool parameter on the left-side curved surface side, which are created with respect to the center curve of the work surface.

FIG. 15 is a diagram provided for explaining a case where a connection curve is generated by spline interpolation (free curve interpolation) for tool parameters.

FIG. 16 is a diagram used for explaining a ruled surface (ruled surface) formed by moving tool parameters represented by straight lines.

FIG. 17 is a diagram showing a ruled surface stretched on the front side when viewed from the tool on the work surface shown in FIG. 5;

[Explanation of symbols]

1 ... Tool 1b ... Tool tip 1s ... Side blade 1t ... Bottom blade 11 ... Head 21 ... NC data creation system 22 ... NC data creation unit 48 ... Step 51 ... Work machining surface 52, 53 ... End point 54 ... Machining surface content side 55 ... Machining surface side Cv1, Cv2, Cv3 ... Curves Li1, Li2 ... Straight lines Mi1, Mi2 ... Cutting line NLi ... Normal direction of orthogonal plane (plane perpendicular direction) Opi ... Orthogonal plane P01 ... Machining start point Pi1 ... Machining point Pn1 ... Processing end points Pi2, Pi3 ... Intersection points Sf1 to Sf11 ...
Curved surface SfL ... left curved surface Sfr ... right curved surface TL0 ... tangential direction of orthogonal plane

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hideyuki Horii 1-10-1 Shin-Sayama, Sayama-shi, Saitama Honda Engineering Co., Ltd. (72) Kotaro Tanaka 1-10-1 Shin-Sayama, Sayama-shi, Saitama Prefecture Engineering Co., Ltd.

Claims (3)

[Claims] 1. A method for creating surface machining data for machining a workpiece machining surface composed of a plurality of curved surfaces by a rotary tool having a side blade and a bottom blade, which is mounted on a 5-axis machining machine, the method comprising: Create a machining path by laying a ruled surface in a range that does not interfere with the rotary tool, and virtually moving the side blade or bottom blade of the rotary tool along this ruled surface, and correspond to this machining path. A method for creating surface processing data for a 5-axis machine, characterized in that the data to be processed is surface processing data. 2. The work machining surface is between a central curve, two outer curves arranged corresponding to the central curve, and each of the central curve and the two outer curves. In the case of being substantially defined by a plurality of curved surfaces stretched over, the ruled surface is stretched on each of the two outer curved sides with the central curve as a ridge line, and the processing path is the The one point on the circumference where the bottom blade and the side blade of the rotary tool are connected is set as a path which moves from the processing start point to the processing end point along the central curve. How to create surface processing data for 5-axis machine. 3. When the ruled surface is stretched, an orthogonal plane in which the central curve is a normal line is created at the processing start point, and each intersection point of the two outer curves on the orthogonal plane is defined. Obtaining, each straight line connecting the processing start point and each intersection, and each cutting line in each curved surface connecting the processing start point and each intersection, connecting the processing start point and each intersection When each straight line does not intersect with each cut line of each curved surface on the orthogonal plane, it is determined that the work machining surface and the rotary tool do not interfere with each other, and when intersecting, the work. When it is determined that the machining surface and the rotary tool interfere with each other, and when it is determined that they interfere with each other, the straight line connecting the machining start point and the intersection is separated from the content of the workpiece with the machining start point as a fulcrum. Direction on the orthogonal plane By making a straight line that avoids interference by rotating to a position in contact with the mouth line, repeating the procedure from creating the orthogonal plane to determining and avoiding the interference until the machining end point, and a straight line that does not interfere at each machining point and The method for creating surface processing data for a 5-axis machine according to claim 2, wherein a surface stretched between straight lines that avoids interference is used as the ruled surface.