JP2022134756A - Device for evaluating nc programs for multi-axis processing machine, evaluation method, and processing method - Google Patents

Abstract

To evaluate NC programs for a multi-axis processing machine including a rotation axis that can change at least one of a relative direction and inclination of a working tool with respect to workpiece without processing the workpiece.SOLUTION: NC programs for a multi-axis processing machine including a rotation axis that can change at least one of a relative direction and inclination of a working tool with respect to workpiece are evaluated as follows; acquiring a plurality of types of NC programs created on premise of a set length of the working tool and an attachment position of the workpiece, simulating an operation of the working tool according to the acquired NC programs, according to the set length of the working tool and the attachment position of the workpiece, determining flexural rigidity of the working tool during processing and a moving range of the working tool, and selecting an NC program in which the flexural rigidity and the moving range are within allowable ranges.SELECTED DRAWING: Figure 2B

Description

The present disclosure relates to technology for evaluating an NC program for a multi-axis machine.

In NC processing, multi-axis processing machines such as 5-axis processing machines are used in recent years. With such a multi-axis machine, the angle of a tool such as a ball end mill with respect to the machined surface can be relatively freely set regardless of the shape of the machined surface. For this reason, during machining, of the angles formed by the tool with respect to the normal direction of the machining surface, the lead angle, which is the inclination angle of the tool in the direction of movement of the tool, and the tilt angle, which is the angle with respect to the horizontal direction orthogonal to the movement direction By setting the corner to an appropriate angle, the surface after processing is finished smoother than a predetermined surface roughness.

NC programs for such multi-axis machines are created according to the shape to be machined, and CADCAM is used to automatically generate tool machining paths and to simulate machining conditions. (For example, Patent Document 1 below).

JP 2020-98523 A

However, multi-axis machines have a high degree of freedom in various settings for machining, and when machining a free-form surface, how to set the lead angle and tilt angle will reduce the surface roughness of the machined surface. Whether or not it can be done depends on the intuition and experience of the program creator. For example, with a 5-axis machine, you can freely set not only the lead angle and tilt angle, but also the C-axis angle, which is the rotation angle of the main shaft, and the B-axis angle, which is the rotation angle of the workpiece around the Y-axis. Even if an NC program for machining a workpiece can be generated, it is not easy to judge whether the NC program is desirable. Even if the conditions were changed and a plurality of NC programs were created, it was unclear which NC program would be the most desirable for machining. For this reason, the number of prototypes cannot be reduced, and materials are wasted.

The present disclosure can be implemented as the following forms or application examples.

(1) A first aspect of the present disclosure is an evaluation device that evaluates an NC program of a multi-axis machine equipped with a rotary axis capable of changing at least one of the relative orientation and inclination of the machining tool with respect to the workpiece. It is an aspect as. This NC program evaluation device evaluates an NC program of a multi-axis machine having a rotary axis capable of changing at least one of the relative orientation and inclination of the machining tool with respect to the workpiece, A setting unit for setting a plurality of lengths of the machining tool and attachment positions of the workpiece in the multi-axis machine, and an NC program for machining the workpiece into a predetermined shape by the multi-axis machine. a program acquisition unit that acquires a plurality of types of NC programs created on the premise of the set length of the machining tool and the mounting position of the workpiece; and operation of the machining tool according to the acquired NC programs A simulation is performed, and according to the set length of the working tool and the mounting position of the workpiece, the bending rigidity of the working tool during the working and the movement range of the working tool are obtained, and the bending rigidity and the movement range of the working tool are obtained. and a selection unit that selects the NC program in which the movement range is within the allowable range.
According to such an NC program evaluation device, in a multi-axis machine equipped with a rotating shaft capable of changing at least one of the relative orientation and inclination of the machining tool with respect to the workpiece, the bending rigidity and the movement range of the machining tool You can select an NC program that is within the allowable range. Therefore, the NC program can be evaluated without actually machining the workpiece. Moreover, it is easy to avoid machining using an inappropriate NC program.
(2) In such a configuration, the plurality of types of NC programs, on the premise of the set length of the machining tool and the mounting position of the workpiece, are configured to set at least the tilt angle and the lead angle of the machining tool. Analysis for analyzing the movement of the tip of the machining tool including the angular change around the rotation axis for each of the plurality of types of NC programs for the selected NC program part, the bending rigidity and the movement range, and the amount of reversal of the analyzed tip of the machining tool about the rotation axis as indicators, among the plurality of types of NC programs, the machining of the workpiece is and an output for identifying a suitable NC program and outputting the result. By doing so, it is possible to specify and output an NC program suitable for machining the workpiece using the amount of reversal of the rotation axis as an index in addition to the bending rigidity and the movement range. The output from the output section may be realized by displaying on a display or the like, or may be used to actually operate the multi-axis machine.
(3) In such a configuration, when the machining of the workpiece by the machining tool is finish machining, the output unit outputs , the NC program with the least reversal around the rotation axis may be output as the NC program suitable for the machining. This makes it easier to achieve the accuracy required for finishing.
(4) In such a configuration, when the machining of the workpiece by the machining tool is rough machining performed before finishing machining, the output unit outputs the NC program with high bending rigidity to the An NC program suitable for the machining may be output rather than an NC program with less reversal around the rotation axis. This makes it easier to shorten the machining time required for rough machining.
(5) In such a configuration, when the NC program cannot be identified due to the bending rigidity and the amount of reversal around the rotation axis, the output unit sets the movement range of the tip of the machining tool to be smaller than other NC programs. It may specify the NC program and output the result. In this way, even if an NC program suitable for machining a workpiece cannot be specified depending on the bending rigidity and the amount of reversal around the rotation axis, an NC program suitable for machining the workpiece can be specified.
(6) A second aspect of the present disclosure is a method of evaluating an NC program of a multi-axis machine equipped with a rotary axis capable of changing at least one of the orientation and inclination of the machining tool relative to the workpiece. be. This method is an NC program in which a plurality of lengths of the machining tool and mounting positions of the workpiece are set in the multi-axis machine, and the multi-axis machine processes the workpiece into a predetermined shape. Acquiring a plurality of types of NC programs created on the premise of the set length of the machining tool and the mounting position of the workpiece, simulating the operation of the machining tool according to the acquired NC programs, According to the set length of the working tool and the mounting position of the workpiece, the bending rigidity of the working tool and the moving range of the working tool during the working are obtained, and the bending rigidity and the moving range are obtained. is within the allowable range.
According to such an NC program evaluation method, in a multi-axis machine equipped with a rotary axis capable of changing at least one of the relative orientation and inclination of the machining tool with respect to the workpiece, the bending rigidity and the movement range of the machining tool You can select an NC program that is within the allowable range. Therefore, the NC program can be evaluated without actually machining the workpiece. Moreover, it is easy to avoid machining using an inappropriate NC program.
(7) In such a configuration, the plurality of types of NC programs, on the premise of the set length of the machining tool and the mounting position of the workpiece, are configured to set at least the tilt angle and the lead angle of the machining tool. and analyzing the movement of the tip of the machining tool including the angular change about the rotation axis for each of the plurality of types of NC programs for the selected NC program, Using the bending rigidity, the movement range, and the degree of reversal of the tip of the machining tool analyzed around the rotation axis as indices, an NC program suitable for the machining of the workpiece from among the plurality of types of NC programs Identifies a program and outputs its results. By doing so, it is possible to specify and output an NC program suitable for machining the workpiece using the amount of reversal of the rotation axis as an index in addition to the bending rigidity and the movement range. The output from the output section may be realized by displaying on a display or the like, or may be used to actually operate the multi-axis machine.
(8) Furthermore, a third aspect of the present disclosure operates each part of the multi-axis machine using the NC program specified by the NC program evaluation method of the second aspect, It is an aspect as a processing method using a multi-axis processing machine. In this way, it is easy to avoid machining the workpiece with an inappropriate NC program.
(9) In such a processing method, the multi-axis processing machine has a spindle device that chucks and rotates the processing tool on the C-axis, which is a turning axis that is tilted 45 degrees with respect to the Y-axis along the vertical direction. It may be a 5-axis processing machine that rotates around.
(10) Further, the processing tool may be a ball end mill having a processing hemisphere with a predetermined radius at its tip.
(11) Furthermore, it is also preferable that the C-axis passes through the center point of the machining hemisphere of the ball end mill.
In this way, the C-axis is turned around the center point of the machining hemisphere of the ball end mill, so large turning of the C-axis is suppressed, and machining accuracy can be improved.
(12) The present disclosure can also be implemented as aspects other than the above, such as a control method for a multi-axis machine, a method for selecting an NC program, and a method for generating an NC program. Furthermore, it may be implemented as a control device for a multi-axis machine incorporating the above-described NC program evaluation device, or as a production system integrating these multi-axis machine, other processing devices, transfer devices, and the like.

FIG. 4 is an explanatory diagram for illustrating the operation of the 5-axis machine; The perspective view of a turning spindle device. FIG. 4 is an explanatory view of the turning range of the main shaft in the turning main shaft device as viewed from the turning axis direction; 1 is a schematic configuration diagram of a program evaluation device according to an embodiment; FIG. A block diagram of an NC program evaluation device. Explanatory drawing which illustrates the cross-sectional shape for calculating|requiring the tool length and bending rigidity of a rotary tool. Explanatory drawing which shows the attachment position of a workpiece|work. Explanatory drawing for demonstrating the state of the tool in a free-form surface. Explanatory drawing which shows the tilt angle of a tool. FIG. 4 is an explanatory diagram showing an example of the arrangement of processing point sequences on the XZ plane; Explanatory drawing showing the vector coordinates of each part of the ball end mill viewed from the origin of the machine. 4 is a flowchart showing evaluation processing of an NC program; An explanatory diagram illustrating initial values of the work mounting position and the length of the rotary tool. FIG. 4 is an explanatory diagram illustrating setting ranges and intervals of a tilt angle and a lead angle; FIG. 4 is an explanatory diagram illustrating coordinate values of each axis for each step in an NC program; FIG. 5 is an explanatory diagram illustrating the result of determining the machining range and machine stroke from the mounting position of the workpiece and the tool length; Explanatory drawing which shows the evaluation result of NC program by machining mode. FIG. 4 is an explanatory diagram illustrating the amount of rotation of the tip of the tool about the B-axis and the C-axis; FIG. 4 is an explanatory diagram showing an example of a three-dimensional movement amount of the tip of the tool;

A. Configuration of 5-axis machine:
An NC program evaluation device 100 (FIGS. 2A and 2B) for a multi-axis machine according to an embodiment evaluates a machining program for a 5-axis machine 10. FIG. Therefore, first, an overview of the five-axis machine 10 that performs machining according to a machining program will be described with reference to FIGS. 1A, 1B, and 1C. Each figure used for explanation is a schematic diagram, and the shape of each part may not necessarily be exact.

The 5-axis processing machine 10 is a tilting and turning type 5-axis processing machine that turns the spindle device 30 around a turning axis (C-axis) that is tilted 45 degrees with respect to the Y-axis. The 5-axis machine 10 includes a bed 11, a column 12, a saddle 13, a swivel spindle device 20, a slide table 14 and a turntable 15, as shown in FIG. 1A. The bed 11 has a substantially rectangular shape and is placed on the floor. A column 12 is erected on the bed 11 .

A saddle 13 is provided on the side surface of the column 12 so as to be movable in the X direction by a servomotor 71 . A servomotor 72 is provided on the side surface of the saddle 13 so that the turning spindle device 20 to which the spindle device 30 is attached can be moved in the Y direction corresponding to the vertical direction. A slide table 14 is provided on the bed 11 and is movable in the Z direction by a servomotor 73 . A turntable 15 is provided on the slide table 14 so as to be rotatable around an axis (B axis) along the Y direction. A work WK is fixed to the turntable 15 via a jig. The rotation angle .theta.b of the B-axis is measured counterclockwise from the origin position set on the turntable 15 facing the turntable 15 as an angle of 0.degree. The angle θb of the B axis is detected using a detector such as an encoder (not shown).

As shown in FIG. 1B, the turning spindle device 20 includes a turning shaft 21 and a turning main body portion 22 that constitute a turning portion, a fixed main body portion 23 as a fixed portion, a speed reduction mechanism portion 24, and a servomotor 25. I have. The swivel spindle device 20 rotates the swivel main body 22 around a swivel axis (C-axis) tilted 45 degrees with respect to the Y-axis in the YZ plane shown in FIG. 1B. This state is shown in FIG. 1C. FIG. 1C is an arrow view of the spindle device 30 attached to the swivel main body 22 as seen in the C-axis direction, which is the swivel axis. The swivel spindle device 20 rotates the swivel shaft 21 together with the swivel main body portion 22 with respect to the fixed main body portion 23 . As a result, the turning spindle device 20 changes the posture (orientation of the rotation axis R) of the spindle device 30 from the horizontal direction (0 degrees) through the vertical direction (180 degrees) to a predetermined angle θ (for example, 270 degrees), as shown in the figure. ) to index the rotation of the spindle device 30 . The rotation angle of the swivel body 22 (swivel shaft 21) rotates counterclockwise when the main spindle unit 30 faces the spindle unit 30, with the R-axis of the spindle unit 30 being horizontal as the origin (θc=0). measure. This angle θc is detected, for example, using a detector such as an encoder (not shown).

The direction vector (X, Y, Z) of the R axis with respect to the rotation angle θ about the C axis is, as shown in FIG. 1C,
(0, 0, 2) when the C-axis angle θc is 0°,
(√2, 1, 1) when the C-axis angle θc is 90°,
(0, 2, 0) when the C-axis angle θc is 180°,
(-√2, 1, 1) when the C-axis angle θc is 280°.
General formula (1) is
X=√2·sin θc
Y=-cosθc+1
Z = cos θc + 1 (1)
is. When the C-axis angle θc is 0°, it is set to (0, 0, 2) because when θc=0, the R-axis is horizontal and is in a state along the Z-axis direction. be. Since the direction vector only indicates the direction of the axis, it is not necessary to normalize the magnitude (length) of the vector so that it becomes a unit vector, but it is normalized here so that it matches the result of the general expression. . Therefore, if there is no need for generalization, it may simply be treated as indicating only the direction, and the magnitude of the direction vector may not be constant depending on the angle θc. This is the same when dealing with the direction vector about the angle θb around the B axis. As shown in FIG. 1A, positive and negative values in the X, Y, and Z directions are positive (+) in the vertical direction and negative (-) in the vertical direction. When the device 30 is viewed from the front, the right-hand direction is positive (+) and the left-hand direction is negative (-). With respect to the Z-axis, the depth direction is positive (+) and the front direction is negative (-).

The main shaft device 30 has a main shaft 31 that rotates around a rotation axis R and a servomotor 25 that rotates the main shaft 31 built into the main shaft device 30 . The spindle 31 has a chuck device for gripping the rotating tool 32 at its tip, and the rotating tool 32 has a ball end mill and a tool holder 41 for gripping the ball end mill. The rotary tool 32 is taken out from the tool magazine 60 by an automatic tool changer (not shown), attached to the spindle 31, removed, and stored in the tool magazine 60. FIG. The ball end mill is mounted on the spindle device 30 so that the reference point b for machining of the ball end mill is positioned at the intersection of the C axis and the R axis. The processing reference point b will be described later.

B. Creating an NC program:
FIG. 2A is a schematic configuration diagram showing the NC program evaluation device 100 together with the 5-axis machine 10. As shown in FIG. In the figure, the NC program evaluation device 100 and the 5-axis machine 10 are connected via the NC control device 90 so that the 5-axis machine 10 can be operated and processed by the NC program specified and output by the NC program evaluation device 100. connected. The connection between the NC control device 90 and the 5-axis machine 10 will be described later. The NC program evaluation device 100 is also connected to a CAD device 80, and with the support of the CAD device 80, also creates an NC program. Of course, the NC program evaluation device 100 can also be configured independently of one or both of the 5-axis machine 10 and the CAD device 80 .

As shown in FIG. 2B, the NC program evaluation apparatus 100 has an input unit 101 for inputting various information and data necessary for the operation of the NC program evaluation apparatus 100, an input storage unit 102 for storing the input information and data, and an input unit 102 for storing the input information and data. An NC program creation unit 103 creates an NC program according to the information and data obtained, an NC program storage unit 104 stores the created NC program, a machining simulation unit 105 reads out the stored NC program and simulates it, and a simulation A motion storage unit 106 for storing motions of the 5-axis machine 10, an analysis unit 107 for analyzing simulated motions, an analysis result storage unit 108 for storing analysis results, and various information necessary for processing of the NC program evaluation device 100 are displayed. and a display unit 110 that functions as a CAM (computer-aided manufacturing) in cooperation with each other. A CAM is a computer loaded with a CAM application. Hardware for exchanging electrical signals with the external device is also incorporated in the input unit 101 or the like that is connected to an external device such as a keyboard or a mouse.

In this embodiment, among the units shown in FIG. 2B, the NC program creation unit 103, the machining simulation unit 105, and the analysis unit 107 are realized by a single CPU 111 as hardware, and this CPU 111 executes a specific program. By doing so, the function of each part is realized. Also, the NC program storage unit 104 , the motion storage unit 106 , and the analysis result storage unit 108 are realized as specific storage areas of the storage device 112 . Of course, the CPU 111 may be provided for each function, and the storage device 112 may also be implemented as different hardware for each storage unit. The storage device 112 may be implemented as part of the main memory by a semiconductor memory, or may be implemented as an external storage device such as a hard disk or SSD.

The NC program creation unit 103 creates a machining program for the 5-axis machine 10 . The program itself is created by a programmer with the assistance of CAD, and is created by inputting the coordinates and program code necessary for machining from the input unit 101 . To create a machining program, it is necessary to set the length of the rotary tool 32 and the mounting position of the work WK. As shown in FIG. 3A, the rotary tool 32 comprises a tool portion 32a having a tip formed for processing and a holder portion 32b for fixing to the chuck 41. Of these, the rotary tool 32 is attached to the holder portion 32b. The length from the tip of the holder portion 32b to the tip of the tool portion 32a when attached to the chuck 41 via the tool is called a tool length L. FIG. If a long holder portion 32b is used, the tool length L is shortened, and conversely, if a short holder portion 32b is used, the tool length L is lengthened. In this way, while the rotary tool 32 is cantilevered by the chuck 41, a force that bends the tool portion 32a is applied to the tip, so the tool portion 32a is required to have sufficient bending rigidity kB to resist this force. . A representative example of the rotary tool 32 is a multi-bladed ball end mill such as a two-bladed or three-bladed tool. These rotary tools 32 are made of high-speed tool steel, cemented carbide, or the like.

The bending rigidity kB of the rotary tool 32 can be obtained from the following equation (2) in the case of a cantilever.
kB=E・I/L (2)
Here, E is the Young's modulus of the material (unit: MPa), I is the geometrical moment of inertia (unit: mm ⁴ ), and L is the above-described tool length (unit: mm). Of these, the Young's modulus E is determined by the material, and the geometrical moment of inertia I is also determined by the shape of the rotary tool 32 . However, if the rotary tool 32 has a complicated shape, the geometrical moment of inertia I must be obtained by dividing it into minute sections. Therefore, data provided by the rotary tool 32 or an operation program provided by the CAD device 80 or the like may be used for determination. In any case, the bending rigidity kB of the rotary tool 32 can be obtained if the type of the rotary tool 32 used for processing and the tool length L when attached to the chuck 41 are known. The handling of the bending stiffness kB in the evaluation of the NC program will be explained later in detail.

In addition, it is necessary to decide where on the turntable 15 the workpiece WK is to be placed prior to machining. The center position of the turntable 15 is determined. FIG. 3B shows the turntable 15 as seen from the Y-axis direction. The center of the turntable 15 is the center of the X and Z axes, that is, the origin OP of X=0 and Z=0. How the work WK is set with respect to the origin OP depends on the machining shape and the specifications of the program of the 5-axis machine 10. For example, in the example shown in FIG. It can be expressed as the amount X, Z that the center WP is deviated from the origin OP of the turntable 15 in the X-axis and Z-axis directions. The quantities X, Z indicating this arrangement distinguish between positive directions +X, +Z and negative directions -X, -Z from the origin OP, as shown. In this embodiment, the mounting range of the work WK in the X-axis direction and the Z-axis direction is from -100 mm to +100 mm. Of course, with the end point EP of the turntable 15 as the origin, the position of the work WK may be indicated only by positive values. As for the work WK, the position of the work WK may be set based on how far one of the corners (for example, the corner CP) of the work WK is from the origin OP of the turntable 15 . The position of WK in the Y-axis direction is Y=−100 mm when the lower surface of the work WK (surface on the turntable 15 side) is in contact with the turntable 15 . The position of the work WK on the turntable 15 can be set above the surface of the turntable 15 by interposing a base or the like, and the upper limit is +100 mm in this embodiment.

The NC program creation unit 103 uses, as input data, the shape data of the workpiece WK created by the CAD device 80 and the inclination (lead angle and tilt angle) of the rotary tool 32 with respect to the normal line NL to the free-form surface, to create an NC for machining. create a program Since the peripheral speed of the rotating tool 32 increases as it moves away from the center of rotation, it is tilted with respect to the surface of the work WK during machining. This state is illustrated in FIG. 3C. The traveling direction of the rotary tool 32 is indicated by TD. In this case, the lead angle θL is the angle at which the rotary tool 32 is inclined in the moving direction with respect to the normal direction NL to the machined free-form surface. Here, the normal direction NL to the machined free-form surface is a direction passing through the machining point a by the ball end mill, which is the rotary tool 32, and the center point b of the ball end mill. The center point b is on the turning center axis of the ball end mill used as the rotary tool 32 and is the center point of the machining hemisphere with the radius r. Further, as shown in FIG. 3D, the angle at which the rotary tool 32 is inclined from the normal line NL at the machining point in the direction perpendicular to the moving direction TD and the normal line direction is called a tilt angle θT. Both the lead angle θL and the tilt angle θT have positive and negative signs. The lead angle .theta.L represents an angle of tilting with respect to the moving direction TD as a positive angle, and an angle of tilting backward in the direction opposite to the moving direction TD as a negative angle. The tilt angle θT is a positive angle when viewed from the movement direction TD, and a negative angle when viewed from the movement direction TD. Creation of an NC program by the NC program creation unit 103 will be described later in detail.

A plurality of created NC programs are stored in the NC program storage unit 104 . An input screen is displayed on the display unit 110 from the NC program creation unit 103 . The inclination (lead angle and tilt angle) of the rotary tool 32 with respect to the normal NL to the free-form surface is input from the input unit 101 to the NC program creating unit 103 via the input screen. The tip of the ball end mill has a hemispherical shape, and the radius r of the hemispherical shape is input from the input unit 101 to the NC program creating unit 103 via the input screen. The length of the ball end mill from the tip to the tool holder 41 is input from the input unit 101 to the NC program creating unit 103 via the input screen. The shape data of the workpiece WK with respect to the machine origin M, which will be described later, is input from the input unit 101 to the NC program creating unit 103 via the input screen. The shape of the work WK is displayed on the display unit 110 from the NC program creation unit 103, and a machining pattern (contour line cutting, XZ straight line cutting) can be selected for each area of the work WK. Data input from the input unit 101 to the NC program creation unit 103 is stored in the input storage unit 102 .

An NC program for machining the workpiece WK into a predetermined shape is created as a set of point sequences tracing the tip of the rotary tool 32 . FIG. 4 schematically shows movement of the tip of the rotary tool 32 when the upper surface (XZ plane) of the work WK is machined as a free-form surface by XZ linear cutting. In this example, a ball end mill is used as the rotary tool 32, and from point Gd1, which is the first machining point a of the workpiece WK, to points Gd2, Gd3, and so on. Machining is performed while sequentially moving the ball end mill in the Z direction. Each point Gd1, Gd2, . . . is associated with point data corresponding to the surface shape of the work WK. Therefore, FIG. 4 corresponds to the arrangement of the three-dimensional coordinates (X, Y, Z) of the machining point a along the XZ alignment on the upper surface (XZ plane) of the work WK. As will be described later, the 5-axis machine 10 obtains the center point b of the ball end mill, which is the rotary tool 32, from the coordinates of the machining point a, and performs machining control. The interval Δz between the points Gd1, Gd2, . When the upper surface of the work WK is machined to the end in the Z direction, the tip position of the ball end mill is moved in the X direction by Δx. This amount of movement Δx should be less than the diameter of the hemispherical tip of the ball end mill. After moving the tip of the ball end mill by .DELTA.x in the X direction, machining is performed while moving toward the end on the opposite side in the Z direction, that is, in the -Z direction. Thereafter, similarly, the upper surface of the work WK is continuously machined.

During such machining, the rotary tool 32 is set at a predetermined lead angle θL and tilt angle θT with respect to the work WK. Therefore, when the machining reaches the end in the Z direction and the machining direction is reversed, it becomes necessary to change the angle of the rotary tool 32 with respect to the workpiece WK in order to make the lead angle θL and the tilt angle θT the same during machining. . The angle of the ball end mill with respect to the front surface of the workpiece WK is actually realized by rotating the main shaft (rotating shaft) R of the main shaft device 30 around the C-axis, but the C-axis is tilted 45 degrees from the vertical. Therefore, in order to move the tip of the ball end mill in the Z-axis direction of the work WK while realizing the predetermined lead angle θL and tilt angle θT, the work WK is rotated around the B-axis, and the work WK is moved with respect to the Z-axis. is set to a predetermined angle, and the workpiece WK is relatively moved in the Z-axis and X-axis directions.

In addition, since the normal direction of the surface of the workpiece WK changes depending on the machining shape, in order to keep the lead angle θL and the tilt angle θT constant, the C-axis angle is changed. It is necessary to change the amount of movement relatively. In some cases, it may be necessary to rotate the work WK around the B axis. Changes in the C-axis angle and B-axis angle during machining, displacement in the Z and X directions, and changes in displacement speed per time (acceleration) change the accuracy of the machined surface of the workpiece WK. Therefore, NC programs are required to be created so as to obtain high machining accuracy in such machining. Although the angle of the C-axis changes greatly at the end of the work WK in the Z direction, the rotation of the C-axis at the end of processing does not directly affect the machining accuracy of the surface of the work WK. .

The NC program is created as a set of point data along the Z direction in XZ straight line cutting as described above. The point data can be grasped as the coordinates of the machining point by the ball end mill viewed from the work origin (0, 0, 0). The coordinates of the machining point can be obtained as a vector from the work origin (0, 0, 0) and the machine origin, as shown in FIG. FIG. 5 shows the X, Y, and Z directions separately for the upper and lower stages on the left side of the drawing. state.

In FIG. 5, point b is the central point of the machining hemisphere with radius r, on the center axis of rotation of the ball end mill used as rotary tool 32, as shown in other figures. A direction passing through the center point b from the processing point a is the normal direction NL. The lead angle θL and tilt angle θT of the rotary tool 32 are angles with respect to the normal direction NL. In this embodiment, since a ball end mill is used as the rotary tool 32, the machining point a does not change even if the rotary tool 32 is tilted about the center point b by the predetermined lead angle .theta.L and tilt angle .theta.T. The position of the machining point a is a position where the normal line from the machining surface passes through the center point b of the machining hemisphere. A normal vector from the machining point a to the center point b of the machining hemisphere is represented by Vab.

A machining point a on the upper surface of the work WK by the ball end mill, which is the rotating tool 32 for machining, is expressed as (Xa, Ya, Za, Vab) with respect to the origin of the work WK. Similarly, the center point b of the working hemisphere is expressed as (Xb, Yb, Zb, Vab) with respect to the work origin. When creating an NC program, a rotating tool 32 is attached so that the position of the center point b of the machining hemisphere of the ball end mill does not change even if the spindle device 30 is rotated around the C axis. The position of the processing point a changes. On the other hand, even if the rotary tool 32 is tilted about the center point b by the predetermined lead angle .theta.L and tilt angle .theta.T, the machining point a does not change. If the coordinate of b is obtained, the five-axis machine 10 can perform machining control including control of the rotation angle around the C-axis. Therefore, the position (Xa, Point data (Xb, Yb, Zb) of the center point b is obtained as a position moved by a radius r along the normal vector Vab from Ya, Za). In this way, the point data string of the point b necessary for controlling the rotary tool 32 is generated from the point data string of the machining point a corresponding to the machining shape (FIG. 4).

The positional relationship between the workpiece WK and the ball end mill, which is the rotating tool 32, when machining the workpiece WK is determined by the coordinates of the machining point a from the workpiece origin (0, 0, 0), and the spindle device for turning the ball end mill. 30 around the C-axis and the rotation angle .theta.b around the B-axis of the turntable 15 on which the workpiece WK is placed. First, the rotation angle .theta.c about the C-axis of the spindle device 30 will be explained. It has already been explained that the direction vector for the rotation angle .theta.c about the C-axis can be expressed by the general formula (1). When a predetermined lead angle .theta.L and tilt angle .theta.T are set for machining, the spindle device 30 is rotated around the C-axis according to the normal direction NL of the machining surface, the lead angle .theta.L and the tilt angle .theta.T.

In order to achieve the predetermined lead angle .theta.L and tilt angle .theta.T, it may be necessary to rotate the workpiece WK around the B axis. Actually, it is not possible to set the lead angle θL of the rotary tool 32 to a negative angle, that is, to tilt the rotary tool 32 in the -Z direction only by rotating around the C axis. In this case, it is usually necessary to rotate the work WK around the B axis. If the direction vector (X, Y, Z) when the rotation angle θb of the B axis is 0° is represented by (0, 0, 1), the direction vectors at 0°, 90°, 180°, and 270° are teeth,
(0, 0, 1) when the B-axis angle θb is 0°,
(-1, 0, 0) when the B-axis angle θb is 90°,
(0, 0, -1) when the B-axis angle θb is 180°,
(1, 0, 0) when the B-axis angle θb is 280°.
changes like Putting this into a general formula,
Assuming that (xb, yb, zb) when the B-axis angle θb is 0°,
When the B-axis angle θb is 90°, (-xb, yb, zb),
When the B-axis angle θb is 180°, (-xb, yb, -zb),
When the B-axis angle θb is 280°, it is (xb, yb, -zb).
Since the B axis is an axis along the Y direction, even if the angle θb around the B axis changes, the value of the machining point aY does not change.

Therefore, when creating an NC program, the lead angle θL and tilt angle θT for machining are input, and the lead angle θL and tilt angle θT are considered in the machining shape acquired from the CAD device 80, and a plurality of machining points a Select the coordinates (Xa, Ya, Za, Vab) containing the normal vector at one processing point a from among, find the position shifted from the point b by the radius r in the Vab direction as the position of the center point b, and find the center The angles of the C axis and the B axis are obtained when the rotary tool 32 is tilted by the lead angle θL and the tilt angle θT with respect to the normal line NL (Vab) around the point b. The NC program sets the angle of each part of the 5-axis machine 10 (revolving main body part 22, turntable 15) and each part of the 5-axis machine 10 in the order of the C-axis, B-axis, Y-axis, and XZ-axis so as to satisfy these. The positions of (swing spindle device 20, saddle 13, slide table 14) are obtained, and the 5-axis machine 10 is operated via the NC control device 90. FIG. Similarly, for the other machining point a, the angles and positions of the parts of the 5-axis machine 10 are obtained in the order of the C-axis, B-axis, Y-axis, and XZ-axis.

By performing such work in accordance with the machining shape, the operator changes the inclination (lead angle and tilt angle) of the rotary tool 32 with respect to the normal NL of the free-form surface to create a plurality of types of NC programs. A plurality of created NC programs are stored in the NC program storage unit 104 .

Machining of the workpiece WK realized by a plurality of NC programs created in this manner can be simulated by the machining simulation unit 105 . The movement of the workpiece WK and the ball end mill by each NC program is simulated and displayed on the display unit 110 . At this time, the X-axis position, Y-axis position, Z-axis position, B-axis angle, and C-axis angle are displayed in the area 110a in the same screen of the display unit 110 according to the movement of the workpiece WK and the ball end mill. display (see FIG. 2B). The X-axis position, Y-axis position, Z-axis position, B-axis angle, and C-axis angle are stored in the motion storage unit 106 for each time. Based on the X-axis position, Y-axis position, Z-axis position, B-axis angle, and C-axis angle for each time stored in the motion storage unit 106, the analysis unit 107 analyzes the X-axis, Y-axis, Analyze Z-axis, B-axis, and C-axis motion. Details of the analysis will be described later. The analyzed X-axis, Y-axis, Z-axis, B-axis, and C-axis movements are stored in the analysis result storage unit 108 for each NC program. After analysis of a plurality of types of NC programs is completed, analysis results are read out for each NC program from the analysis result storage unit 108, and the contents thereof are compared. As a result of the comparison, one of a plurality of types of NC programs is specified and output. The output destination is the display section 110 or the NC control device 90 . The display unit 110 is a liquid crystal display or the like, and displays the specified result from the analysis result storage unit 108, that is, which NC program is desirable for machining the workpiece WK.

Using the NC program transmitted to the NC controller 90 of the 5-axis machine 10, the NC controller 90 can actually operate the 5-axis machine 10. FIG. The operation of the five-axis machine 10 in this case may be to actually machine the workpiece, or to check the movement of the slide table 14 and the rotary tool 32 without placing the workpiece. may The NC controller 90 outputs drive signals to the servomotors 71 to 74 and the servomotor 25 provided in the 5-axis machine 10 according to the NC program to control the positional relationship between the workpiece WK and the spindle device 30. , the ball end mill, which is the rotating tool 32, can be rotated at high speed to machine the workpiece WK.

C. Evaluation of the NC program:
Processing for evaluating the NC program will be described according to the flow chart of FIG. This process is a process in the NC program evaluation apparatus 100 described above, and is started and executed when an NC program for machining the workpiece WK into a specific machining shape is created and evaluated. When this processing routine is started, processing for identifying a machining shape is first performed (step S110). The machining shape is given as three-dimensional data from the CAD device 80 .

After specifying the machining shape, the mounting position of the work WK and the tool length L are tentatively determined (step S112). A person in charge (hereinafter referred to as a programmer) sets (step S114). This is because, as shown in FIG. 7, the mounting position of the work WK and the tool length L are provisionally set, and the range in which the mounting position of the work WK and the tool length L are to be changed is set. be. In this embodiment, the attachment position of the workpiece WK and the tool length L are not set one by one by the programmer, but are sequentially changed within a predetermined range, and exhaustive simulation is performed for all cases.

In the example shown in FIG. 7, the temporary setting of the mounting position of the workpiece WK is (0, -50, 0) in the (X, Y, Z) coordinate system, and the possible range is XYZ. , from the value −100 to the value +100. The tool length L is temporarily set to L=170 mm, and the variable range of the length is from 150 to 200 mm. In this embodiment, the mounting positions (X, Y, Z) of the workpiece WK are changed at intervals of 10 mm, and the tool length L of the rotary tool 32 is changed at intervals of 5 mm. In other words, there are 21×21×21 different work WK mounting positions and 11 different lengths of the rotary tool 32 for machining the same work WK. Of course, the mounting range of the work WK and the range or interval of the tool length L of the rotary tool 32 may be narrower or wider.

After completing the provisional setting of the mounting position of the workpiece WK and the initial values of the tool length L (step S112) and the setting of the mounting range, the tool length L range and the interval (step S114), the programmer changes the acquired machining shape. is displayed on the display unit 110, and while viewing this, the input unit 101 is used to set the lead angle θL and the tilt angle θT (step S120). A program is created (step S130). The setting of the lead angle θL and the tilt angle θT is appropriately set at intervals of 5 degrees within a predetermined range (0 to +20 degrees), as illustrated in FIG. When a ball end mill is used as the rotary tool 32, the lead angle .theta.L and the tilt angle .theta.T are preferably at least 10 degrees or more in terms of machining accuracy. This is because if the angle is 10 degrees or more, a large difference in surface roughness after processing does not occur. Of course, such an angle varies depending on the type of the rotary tool 32, so here, the angle is varied in the range of 0 to 20 degrees at intervals of 5 degrees. Therefore, there are 5×5 combinations of the lead angle θL and the tilt angle θT.

When one type of NC program for machining the obtained machining shape is completed, this NC program is analyzed (step S140). In the analysis, first, the NC program is simulated using the machining simulation unit 105 (step S142), and the XYZ axis coordinates and B Analysis processing of obtaining rotation angle coordinates of the axis and C-axis and analyzing them by the analysis unit 107 (step S145), and processing of storing the analyzed data in the analysis result storage unit 108 in association with the created NC program. (Step S147) is included.

FIG. 9 shows an example of the coordinates on the XYZ axes and the rotation angle coordinates of the B and C axes indicating the positions of the respective parts of the five-axis machine 10 analyzed and acquired as a result of the simulation. In the figure, steps are numbers assigned to each processing point Gd shown in FIG. For each step, the X coordinate, Y coordinate, and Z coordinate are obtained, and the rotation angles about the B axis and C axis are obtained and stored in the motion storage unit 106 .

For one type of NC program, when the creation and data analysis are completed, the setting of the work mounting position and the tool length L of the rotary tool 32 shown in FIG. 7 is changed, and the lead angle θL and It is determined whether or not the setting of the tilt angle θT has been changed and the creation of multiple types of NC programs has been completed (step S150). S150) is repeated. Whether or not the creation of the NC program is completed may be determined by the person in charge of creating the program, or may be determined to be complete when a predetermined number of NC programs, for example, three types of NC programs have been created. Create at least two types of NC programs.

If the creation and analysis of the NC programs are completed for all combinations of settings (step S150: "YES"), then the NC program selection process is performed (step S160). The selection process is performed as follows. First, the analyzed data for each NC program stored in the analysis result storage unit 108 is read, and the NC programs are compared from this data from the following viewpoints.
[1] Determine whether the range in which the rotary tool 32 moves relative to the workpiece WK is within the machining range of the 5-axis machine 10 . The machining range is a range in which the 5-axis machine 10 can perform machining with sufficient accuracy. The term “relative” is used because in the 5-axis machine 10 of the present embodiment, not only the spindle device 30 to which the rotary tool 32 is attached, but also the slide table 14 and the turntable 15 are moved and rotated for machining. for it is done.
[2] Determine whether the range in which the rotary tool 32 moves relative to the work WK is included in the machine stroke of the 5-axis machine 10 . The machine stroke is a range that can be mechanically taken when the 5-axis machine 10 is possible, and is wider than the machining range that guarantees machining accuracy.

During the simulation, a program that does not enter the machine stroke is rejected as a non-running program, so the analysis target is the NC program that is included in the machine stroke. Among them, the programs included in the processing range (in FIG. 10, those whose "processing range" is .largecircle.) are selected. Although not shown, the rotary tool 32 having insufficient bending rigidity kB is also excluded at this stage and not selected. As already explained, the flexural rigidity kB is obtained by the above-mentioned formula (2). Since the Young's modulus E and the geometric moment of inertia I are calculated in advance for the rotary tool 32 based on the material and cross-sectional shape, it is easy to determine the bending rigidity kB by setting the tool length L. be. Since the required bending rigidity kB of the rotary tool 32 can be calculated from the material of the workpiece WK and the amount of processing for one time, the tool length L that is insufficient for the required bending rigidity kB is selected at this stage. not.

In the NC program selected in this way, the setting of the mounting position of the work WK is appropriate, and the range of movement of the rotary tool 32 relative to the work WK is within the machining range of the 5-axis machine 10. Also, the program satisfies the premise that the setting of the type of rotary tool 32 and the tool length L are appropriate, and that the bending rigidity kB of the rotary tool 32 is within the allowable range. Then, machining evaluation is performed for these NC programs (step S170). Processing evaluation is performed based on the following indexes.

<1> A rotary tool 32 having a high bending rigidity kB is prioritized.
<2> Priority is given to NC programs with little or no reversal of the B-axis and C-axis.
FIG. 11 summarizes this processing evaluation.

Here, the bending rigidity kB of the rotary tool 32 of <1> is normalized with the bending rigidity kB of a tool having a predetermined tool length L as a reference. For example, with the bending stiffness kB of the rotary tool 32 calculated in No. 1 setting (type of rotary tool 32 and tool length L) as a reference value of 1.0, the bending stiffness kB in other settings is a relative value. (ratio). Therefore, the higher the numerical value, the higher the bending stiffness kB.

The reversal of the B-axis and C-axis in <2> means the reversal of the rotation direction around the axis that occurs during machining. FIG. 12 shows an example of angular changes (here, rotation amounts) around the B-axis and C-axis from the results of the simulation (step S142) when the 5-axis machine 10 is operated according to the NC program. The horizontal axis of the figure is the number of steps, and the vertical axis is the amount of rotation of each axis. In the figure, it can be seen that the direction of rotation about the B axis is reversed at timings t1, t2, t3, and t4. Inversion does not occur for the C-axis. At the stage of creating the NC program, it is impossible to grasp whether or not reversal around the B-axis and C-axis will occur. This is because, in the example shown in FIG. 4, the NC program is a line of point data (Xa, Ya, Za, Vab) of each machining point a in the Z direction. +1 and point data (Xa, Ya, Za, Vab) change depending on the machining shape, etc. Even a slight change may cause a large change in the rotation angle θc around the C axis and the rotation angle θb around the B axis. could be. Therefore, the presence or absence of such a reversal around the B axis was shown as a processing evaluation. This is because if a reversal occurs around the B-axis or the C-axis, the position at which the rotary tool 32 contacts the workpiece WK for machining may change discontinuously. Therefore, if an NC program that does not cause such reversal is selected, the surface roughness after machining will be small. Of course, if there is no NC program that does not cause reversal around the B-axis and C-axis among a plurality of types of NC programs, the machining program with the least number of reversals is selected. If the number of reversals is the same, the selection may be made from other viewpoints, or from a viewpoint accompanying the reversal around the axis, for example, by comparing the amount of change in the rotation angle (rotational angular velocity) before and after the reversal, It is also possible to select one with a small change in rotational angular velocity.

In this embodiment, based on the above index, as shown in the right end of FIG. 11, in the rough machining performed before the finish machining, the NC program No. 3 is specified as the program suitable for machining the workpiece WK. However, in the finishing process, the No. 2 NC program was specified as a program suitable for machining the workpiece WK. After that, this is output to the outside as processing evaluation. As an output, for example, the corresponding NC program number is displayed on the display unit 110 . The reason why the bending rigidity kB of the rotary tool 32 is prioritized in rough cutting is that in rough cutting, the cutting depth of the tool is larger than that in finishing, and therefore high bending rigidity kB is often required. Also, the reason why the NC program with little or no reversal of the B-axis and C-axis is prioritized in finishing machining is that high machining accuracy is required.

In the above embodiment, in addition to these indicators,
<3> Priority is given to the NC program in which the moving range of the tip of the rotary tool 32 is small.
You can add an index. An example of the moving range of the tip of the rotary tool 32 is shown in FIG. In the figure, the horizontal axis indicates the number of steps, and the vertical axis indicates the amount of movement in each axial direction. In the example shown in this figure, comparing the moving range RX in the X-axis direction, the moving range RY in the Y-axis direction, and the moving range RZ in the Z-axis direction, the moving range RX in the X-axis direction is the moving range of each axis. the largest of them. Therefore, the maximum movement range is compared for a plurality of types of NC programs, and the NC program with the smallest movement range is selected. This is because the smaller the movement range, the smaller the change in the positional relationship between the rotary tool 32 and the work WK, and the smaller the wear of the rotary tool 32 . Of course, the movement range of the machining tool may be obtained by adding the movement ranges in each of the XYZ axes, comparing the sum of the movement ranges among the NC programs, and specifying the NC program with the smallest movement range. Alternatively, when the rotary tool 32 is moved in at least two axial directions, the distance that the rotary tool 32 actually moves during machining is obtained instead of the movement range for each axis, and this determines the smallest NC program. You may make it select.

Furthermore, as another indicator,
<4> Priority is given to the NC program in which the change in the angular velocity of the tip of the rotary tool 32 is small.
You can add an index. A change in acceleration of each axis is obtained, and an NC program with a large value is not evaluated. Whether or not the NC program has a large change in the acceleration of each axis may be determined, for example, by treating an NC program with a large number of acceleration changes equal to or greater than a predetermined threshold value as a program with a large acceleration change, or by treating the program with a large acceleration change. The resulting NC program may be treated as a program with large acceleration changes. A large change in acceleration means a large change in the force that the tip of the rotary tool 32 and the workpiece WK receive from each other. If an NC program with a small change in the force acting between the rotary tool 32 and the workpiece WK is selected, the surface roughness after machining will be small.

The indicators <3> and <4> described above may be used when the indicators <1> and <2> do not give superiority or inferiority to the evaluation of the NC program. Alternatively, points are given for each type of machining, such as rough machining and finishing machining, and for each index, and the NC program with the best sum of points for each index is evaluated as the NC program suitable for that machining. good too.

In the machining evaluation process (step S170), in addition to the evaluation described above, if there is a relationship between the setting of the lead angle θL and the tilt angle θT in step S120 and the creation of the NC program, the B-axis , Whether the reversal around the C axis is reduced, whether the change in acceleration at the tip of the rotary tool 32 is small, and whether machining with a narrow movement range at the tip of the rotary tool 32 can be realized. You can do work to make the most of it. Such machining evaluation may be performed by simulation, or may be performed while actually machining the workpiece WK. In addition, the selected NC program may be slightly modified based on machining evaluation to further improve its completeness. With the above processing, the NC program evaluation processing routine is terminated.

According to the NC program evaluation device 100 of the 5-axis machine 10 described above, when the range of the mounting position of the workpiece WK and the range of the tool length L of the rotary tool 32 are set, machining can be performed under a plurality of conditions within the range. By obtaining the bending rigidity kB of the rotary tool 32 and the movement range of the rotary tool 32, an NC program can be selected in which the bending rigidity kB and the movement range are within the allowable range. Therefore, it is easy to set appropriate values for the mounting position of the workpiece WK and the tool length L, which have a wide setting range. In addition, NC programs with different settings of the lead angle θL and tilt angle θT in the selected NC program are simulated, and these are evaluated by the amount of reversal around the B and C axes and the bending stiffness kB. However, considering the difference in machining of the workpiece WK (whether it is rough machining or finishing machining), an NC program suitable for that machining can be specified. As a result, a desired NC program can be selected without actually machining the work WK. Therefore, after creating an NC program, it is possible to save the trouble of repeatedly performing machining with the 5-axis machine 10, measuring the surface roughness, etc., and correcting the NC program. As a result, it is possible to shorten the NC program development time, and reduce the materials and man-hours for trial production. Furthermore, the relationship between the setting of the lead angle .theta.L and the tilt angle .theta.T and the quality of the obtained NC program is accumulated as knowledge, which can also contribute to improving the skill of the NC program creator.

As described above, the 5-axis machining center having the B-axis and the C-axis has been described as an example of the 5-axis machining center 10. It doesn't matter if it is. In addition, the machine is not necessarily limited to 5 axes, and may be a multi-axis machine equipped with a rotary axis capable of changing at least one of the orientation and inclination of the machining tool relative to the workpiece, such as a 4-axis machine and a lathe. Even a multifunction machine with added functions can be implemented as an evaluation device for evaluating the NC program. As for the type of machining, it is advantageous to use it in simultaneous 5-axis machining in which 5 axes are controlled simultaneously, but it can also be applied to indexed 5-axis machining. In the present embodiment, XZ straight line cutting has been described as an example of the cutting method, but the same applies to contour line cutting.

In the evaluation apparatus 100 for the NC program described above, different evaluation indices are used for rough machining and finish machining, but either one of the indices may be used for determination. In addition to these indicators, we combine indicators such as the amount of change in the acceleration of the tip of the machining tool and the movement range of the tip of the machining tool, and output the NC program with the highest evaluation from among multiple types of NC programs. good too. Furthermore, other items may be combined.

In the above example, the NC program does not include the process of machining by replacing the rotary tool 32, but the automatic tool changer can be used to replace the rotary tool 32 prepared in the tool magazine 60. It may be applied to an NC program in which machining is continued and the evaluation is performed. In this case, an index for the bending rigidity kB of the tool to be replaced may be obtained again from the material of the tool, the length L of the tool, and the like. Also, as the rotary tool 32, a ball end mill having a machining hemisphere with a radius r at the tip has been described as an example, but the radius r of the ball end mill may be changed.

The workpiece WK is actually machined using the NC program judged to be the most appropriate by the NC program evaluation device 100 of the 5-axis machine 10 described above. In this case, the NC program determined to be appropriate is loaded into the NC controller 90 shown in FIG. 2A, and the NC program is executed. During machining, a ball end mill having the same shape as the rotary tool 32 used in the evaluation of the NC program, that is, the radius r of the machining hemisphere is the same, is attached to the spindle device 30 to machine the workpiece WK. At this time, it is assumed that the C-axis, which is the turning axis of the spindle device 30, passes through the center point b of the machining hemisphere of the ball end mill, as in the evaluation conditions. By doing so, the C-axis turns around the center point of the machining hemisphere of the ball end mill, eliminating large turning of the C-axis and improving the machining accuracy.

In each of the above embodiments, part of the configuration implemented by hardware may be replaced with software. At least part of the configuration implemented by software can also be implemented by a discrete circuit configuration. In addition, when part or all of the functions of the present disclosure are realized by software, the software (computer program) can be provided in a form stored in a computer-readable recording medium. "Computer-readable recording medium" means not only portable recording media such as flexible disks and CD-ROMs, but also various internal storage devices such as RAM and ROM, and fixed to computers such as hard disks. It also includes an external storage device. That is, the term "computer-readable recording medium" has a broad meaning including any recording medium capable of fixing data packets instead of being temporary.

The present disclosure is not limited to the embodiments described above, and can be implemented in various configurations without departing from the scope of the present disclosure. For example, the technical features in the embodiments corresponding to the technical features in the respective modes described in the Summary of the Invention column may be used to solve some or all of the above problems, or Substitutions and combinations may be made as appropriate to achieve part or all. Also, if the technical features are not described as essential in this specification, they can be deleted as appropriate.

DESCRIPTION OF SYMBOLS 11... Bed, 12... Column, 13... Saddle, 14... Slide table, 15... Turntable, 20... Turning spindle device, 21... Turning shaft, 22... Turning main body part, 23... Fixed main body part, 24... Reduction mechanism part , 25... Servo motor, 30... Spindle device, 31... Spindle, 32... Rotary tool, 32a... Tool part, 32b... Holder part, 41... Chuck, 51... X axis, 52... Y axis, 53... Z axis, 60 Tool magazine 71, 72, 73, 74 Servo motor 80 CAD device 90 NC control device 100 NC program evaluation device 101 Input unit 102 Input storage unit 103 NC program creation unit , 104 NC program storage unit 105 machining simulation unit 106 operation storage unit 107 analysis unit 108 analysis result storage unit 110 display unit 111 CPU 112 storage device θL lead angle , θT... tilt angle, NL... normal line, RX, RY, RZ... movement range, WK... workpiece

Claims (11)

An evaluation device for evaluating an NC program of a multi-axis machine having a rotation axis capable of changing at least one of the orientation and inclination of the machining tool relative to the workpiece,
a setting unit for setting a plurality of lengths of the machining tool and attachment positions of the workpiece in the multi-axis machine;
The multi-axis machine is an NC program for machining the workpiece into a predetermined shape, and a plurality of types created on the premise of the set length of the machining tool and the mounting position of the workpiece a program acquisition unit that acquires the NC program of
Simulating the operation of the processing tool by the acquired NC program, and according to the set length of the processing tool and the mounting position of the workpiece, the bending rigidity of the processing tool during the processing and the processing tool a selection unit that obtains a movement range of and selects the NC program in which the bending rigidity and the movement range are within the allowable range;
An evaluation device for an NC program. The plurality of types of NC programs are created by changing at least the tilt angle and the lead angle of the machining tool on the premise of the set length of the machining tool and the mounting position of the workpiece. is an NC program,
an analysis unit that analyzes, for each of the plurality of types of NC programs, of the movement of the tip of the machining tool, including changes in angle about the rotation axis, for the selected NC program;
Using the bending rigidity, the movement range, and the degree of reversal of the tip of the machining tool analyzed around the rotation axis as indices, an NC program suitable for the machining of the workpiece from among the plurality of types of NC programs an output unit that identifies a program and outputs the result;
2. The NC program evaluation device according to claim 1, comprising: The NC program evaluation apparatus according to claim 2,
When the machining of the workpiece by the machining tool is finish machining, the output unit selects an NC program in which the bending rigidity and the movement range are within the allowable range. outputting the NC program with the least amount as an NC program suitable for the machining;
NC program evaluation device. The NC program evaluation apparatus according to claim 2,
When the machining of the workpiece by the machining tool is rough cutting performed before finishing machining, the output unit outputs the NC program with high bending rigidity to less reversal around the rotation axis. An NC program evaluation device that outputs an NC program suitable for the machining from the NC program. The NC program evaluation device according to claim 3 or 4,
When the NC program cannot be specified due to the bending rigidity and the amount of reversal around the rotation axis, the output unit specifies an NC program in which the movement range of the tip of the working tool is smaller than another NC program, and NC program evaluation device that outputs results. A method for evaluating an NC program of a multi-axis machine having a rotary axis capable of changing at least one of the orientation and inclination of the machining tool relative to the workpiece, comprising:
setting a plurality of lengths of the machining tool and mounting positions of the workpiece in the multi-axis machine;
The multi-axis machine is an NC program for machining the workpiece into a predetermined shape, and a plurality of types created on the premise of the set length of the machining tool and the mounting position of the workpiece acquire the NC program of
Simulating the operation of the processing tool by the acquired NC program, and according to the set length of the processing tool and the mounting position of the workpiece, the bending rigidity of the processing tool during the processing and the processing tool and selecting the NC program in which the bending stiffness and the movement range are within the allowable range;
NC program evaluation method. The plurality of types of NC programs are created by changing at least the tilt angle and the lead angle of the machining tool on the premise of the set length of the machining tool and the mounting position of the workpiece. is an NC program,
analyzing the movement of the tip of the machining tool including the angular change about the rotation axis for each of the plurality of types of NC programs for the selected NC program;
Using the bending rigidity, the movement range, and the degree of reversal of the tip of the machining tool analyzed around the rotation axis as indices, an NC program suitable for the machining of the workpiece from among the plurality of types of NC programs 7. The NC program evaluation method according to claim 6, wherein the program is specified and the result thereof is output. A multi-axis machine for machining the workpiece by operating each part of the multi-axis machine using the NC program specified by the NC program evaluation method according to claim 6 or 7. Processing method used. The multi-axis machine is a tilt turning type 5 in which a spindle device that chucks and rotates the machining tool is turned around a C-axis that is a turning axis that is tilted at 45 degrees with respect to the Y-axis along the vertical direction. 9. The processing method according to claim 8, which is a shaft processing machine. 10. The processing method according to claim 9, wherein said processing tool is a ball end mill having a processing hemisphere with a predetermined radius at its tip. 11. The machining method according to claim 10, wherein said C-axis passes through the center point of said machining hemisphere of said ball end mill.

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