Device for carrying out numerical control or regulation of a machine tool

Abstract

The present invention provides a device for carrying out numerical control of a machine tool, wherein the device generates an outward-direction cutting action and a return-direction cutting action. In the device for carrying out numerical control of a machine tool, a tool and a workpiece are caused to move back and forth relative to each other, while the tool and the workpiece are caused to rotate relative to each other, so that the workpiece is cut by both the outward-direction cutting action and the return-direction cutting action, wherein the device for carrying out numerical control of a machine tool is caused to move back and forth relative to each other, while the tool and the workpiece are caused to rotate relative to each other, so that the workpiece is cut by both the outward-direction cutting action and the return-direction cutting action.The control system of a machine tool comprises: a material removal area input unit that analyzes a cutting program and reads the shape of the workpiece removal area to be removed by cutting; a processing criteria input unit that reads the processing criteria for cutting, which include at least the cutting depth of the tool during the outward cutting action and the cutting depth of the tool during the return-direction cutting action; and an action generation unit that generates the outward cutting action and the return-direction cutting action based on the material removal area shape and the processing criteria such that the tool overlaps the uncut portion of the material removal area and the amount of overlap does not exceed the outward cutting depth and the return-direction cutting depth specified in the processing criteria.

Description

TECHNICAL AREA

[0001] The present invention relates to a numerical controller for a machine tool. TECHNICAL BACKGROUND

[0002] In a known technique for controlling a machine tool, a tool is moved relative to the workpiece, based on a machining program, while the workpiece is rotated, in order to perform a cutting operation on the workpiece. It is known that in such a technique, a tool is repeatedly moved back and forth relative to a workpiece, for example, to perform a cutting operation in a forward direction multiple times separately. See, for example, patent document 1. List of references Patent document

[0003] Patent document 1: Unexamined Japanese patent application, publication no. 2005-288563 DISCLOSURE OF THE INVENTION Problems to be solved by the invention

[0004] With this technique, where a workpiece is cut multiple times as described above, a reduction in processing time is expected. To meet this expectation, the cutting process can be performed not only in the forward direction but also in the return direction.

[0005] Unfortunately, a numerical controller that performs cutting operations in both forward and return directions requires specifying the positions and the amount of movement for each cutting operation in a machining program, taking into account the cutting depth for each operation. Creating such a machining program manually is difficult. The more complex the shape being machined, the greater the difficulty of creating the program manually. Using programming support software such as computer-aided manufacturing (CAM) would make creating a machining program relatively easy. However, implementing such software is expensive.To address this problem, a numerical controller is expected to generate cutting operations in both the forward and return directions, while reducing the cost of implementing programming support software. Means to solve the problems

[0006] One aspect of the present disclosure relates to a numerical controller for a machine tool that performs a cutting operation on a workpiece by means of both a cutting operation in a forward direction and a cutting operation in a return direction, by rotating a tool and the workpiece relative to each other while moving the tool and the workpiece back and forth relative to each other. The numerical controller includes: a material removal area input unit configured to analyze a program for the cutting operation and to read a shape of a material removal area of ​​the workpiece to be removed by the cutting operation;a machining condition input unit configured to read machining conditions for the cutting operation, wherein the machining conditions include at least a cutting depth to be made by the tool during the cutting operation in the forward direction and a cutting depth to be made by the tool during the cutting operation in the return direction; and a motion generator configured to generate the cutting operation in the forward direction and the cutting operation in the return direction based on the shape of the material removal area and the machining conditions such that the tool overlaps with a portion of the material removal area yet to be cut, and such that the amount of overlap does not exceed the cutting depth to be made by the tool in the forward direction and the cutting depth to be made by the tool in the return direction. Effects of the invention

[0007] From this perspective, the numerical controller can generate both the forward and reverse cutting processes, while reducing the cost of implementing software. This can shorten the processing time. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 illustrates an exemplary numerical controller for a machine tool according to one embodiment; Fig. 2A shows an example editing program for cutting to any shape with a contour that includes straight sections and a curved section; Fig. 2B shows exemplary descriptions of the in Fig. 2A shown processing program; Fig. 3A is a cross-sectional view to illustrate the [unclear] caused by the [unclear] in Fig. 2A shows the machining program and the specified shape of a removal area and a section (a half section above the axis of rotation Z) of the contour shape of a machined workpiece; Fig. 3B is a cross-sectional view to illustrate the [unclear] caused by the [unclear] in Fig. 2A illustrates the machining program specified shape of the removal area and a section (a half section above the axis of rotation Z) of the contour shape of the machined workpiece; Fig. Figure 4A shows an example editing program for cutting to any shape with a contour that includes straight sections and a curved section; Fig. 4B shows exemplary descriptions of the in Fig. 4A shown processing program; Fig. Figure 5A shows an example editing program for cutting to any shape with a contour that includes straight sections and a curved section; Fig. 5B is an example table for presenting tool identification information and machining conditions for machining with each of the tools; Fig. 6A illustrates exemplary cutting operations of a tool in the forward direction and in the return direction, generated by a motion generator; Fig. 6B illustrates exemplary cutting operations of a tool in the forward direction and in the return direction, generated by the motion generator; Fig. 6C illustrates exemplary cutting operations of a tool in the forward direction and in the return direction, generated by the motion generator; Fig. Figure 7A illustrates exemplary approximate movements generated by the motion generator; Fig. Figure 7B illustrates exemplary approximate movements generated by the motion generator; Fig. Figure 8A illustrates exemplary switching movements between the cutting operations in the forward direction and the cutting operations in the return direction, which are generated by the motion generator; Fig. Figure 8B illustrates exemplary switching movements between the cutting operations in the forward direction and the cutting operations in the return direction, which are generated by the motion generator; Fig. 9A illustrates exemplary restoring movements along the removal area, which are generated by the motion generator; Fig. Figure 9B illustrates further exemplary restoring movements along the removal area, which are generated by the motion generator; Fig. Figure 10 illustrates exemplary distance movements and exemplary approach movements following the restoring movements generated by the motion generator; Fig. 11A illustrates exemplary return movements and exemplary delivery movements generated by the motion generator; Fig. 11B illustrates exemplary return movements and exemplary delivery movements generated by the motion generator; Fig. 12A illustrates exemplary distance movements and exemplary approach movements at the end of the machining process, which are generated by the motion generator; Fig. 12B illustrates exemplary distance movements and exemplary approach movements at the end of the machining process, which are generated by the motion generator; Fig. Figure 13A shows an example machining program for cutting to a shape with only one straight contour, i.e. a rectangular removal area; Fig. Figure 13B shows an exemplary machining program for cutting to a shape with only a straight contour, i.e., a cutting area that includes a combination of a rectangular shape and tapered shapes (right-angled triangular shapes); Fig. Figure 13C shows an exemplary machining program for cutting to a shape with only one straight contour, i.e. a tapered (right-angled triangular) removal area; Fig. 13D shows exemplary descriptions of the in Fig. Editing programs shown in 13A to 13C; Fig. 14A is a cross-sectional view to illustrate the [unclear] caused by the [unclear] in Fig. 13A shows the machining program and the specified shape of the removal area and a section (a half section above the axis of rotation Z) of the contour shape of the machined workpiece; Fig. 14B is a cross-sectional view to illustrate the [unclear] caused by the [unclear] in Fig. 13A shows the machining program and the specified shape of the removal area and a section (a half section above the axis of rotation Z) of the contour shape of the machined workpiece; Fig. Figure 14C is a cross-sectional view to illustrate the [unclear] caused by the [unclear] in Fig. 13A shows the machining program and the specified shape of the removal area and a section (a half section above the axis of rotation Z) of the contour shape of the machined workpiece; Fig. 14D is a cross-sectional view to illustrate the [unclear] caused by the [unclear] in Fig. 13B shows the machining program and the specified shape of the removal area and a section (a half section above the axis of rotation Z) of the contour shape of the machined workpiece; Fig. 14E is a cross-sectional view to illustrate the [unclear] caused by the [unclear] in Fig. 13C shows the machining program and the specified shape of the removal area and a section (a half section above the axis of rotation Z) of the contour shape of the machined workpiece; Fig. Figure 15 illustrates exemplary cutting operations of a tool in the forward direction and in the return direction, which are generated by a motion generator, according to a variant of the embodiment; Fig. Figure 16 illustrates exemplary cutting operations of a tool in the forward direction and in the return direction, which are generated by a motion generator, according to a variant of the embodiment; Fig. Figure 17 illustrates exemplary rotary movements of a tool and a workpiece and exemplary cutting operations in the forward direction and in the return direction according to a variant of the embodiment; Fig. Figure 18A shows a machining program according to a variant of the embodiment, which is an exemplary machining program that enables cutting to a shape with a contour that includes only a curvature; and Fig. 18B is a cross-sectional view to illustrate the [unclear] caused by the [unclear] in Fig. Figure 18A shows the machining program specified form of a removal area and a section (a half section above a rotation axis Z) of the contour shape of a machined workpiece. PREFERRED OPERATING MODE FOR REALIZING THE INVENTION

[0008] Exemplary embodiments of the present invention are described below with reference to the accompanying drawings. The same reference numerals are used to represent identical or equivalent elements in the figures. (First embodiment)

[0009] Fig. Figure 1 illustrates an exemplary numerical controller for a machine tool according to one embodiment. A Fig. 1 Illustrated numerical controller 10 controls or regulates movements of a machine tool 20, specifically cutting movements of a tool T for a workpiece W based on a machining program 5.

[0010] Examples of workpiece W include a circular cylindrical workpiece, a cylindrical workpiece, a conical workpiece, and a frustoconical workpiece. Fig. In Figure 1 and the figures to be described below, the central axis of the workpiece W, which serves as the axis of rotation of the workpiece, is referred to as the “Z-axis” and the axis perpendicular to the Z-axis is referred to as the “X-axis”.

[0011] The machine tool 20 performs a cutting operation on the workpiece W using the tool T. Specifically, the machine tool 20 moves the tool T back and forth along the Z-axis or along the resultant of the Z- and X-axes while the workpiece W is rotated about the Z-axis. In this way, the workpiece W is cut. The machine tool 20 performs a cutting operation on the workpiece W by means of both a cutting operation in the forward direction (i.e., in the -Z direction) and a cutting operation in the return direction (i.e., in the +Z direction). Examples of such a tool T include a tool that incorporates two blades, T1 and T2.

[0012] The machine tool 20 can machine a workpiece not only with a straight shape, but also with a circular shape in one direction along the Z-axis. The machine tool 20 can machine the inner circumferential surface of a workpiece, such as a cylindrical workpiece, as well as the outer circumferential surface of a workpiece.

[0013] The numerical controller 10 controls a rotary movement of the workpiece W and a translational movement of the edge T3 of the tool T. The following section describes in detail how the translational movement of the edge T3 of the tool T is controlled. The numerical controller 10 includes a material removal area input unit 12, a machining condition input unit 14, a motion generator 16, and a memory unit 18.

[0014] Components of the numerical controller 10 (except for the memory unit 18) are each configured as an arithmetic processor, such as a central processing unit (CPU), a digital signal processor (DSP), or a field-programmable gate array (FPGA). The components of the numerical controller 10 (except for the memory unit 18) have various functions that are implemented by executing predefined software (a predefined program) stored in the memory unit 18. The components of the numerical controller 10 (except for the memory unit 18) can have various functions that are implemented either through interaction between hardware and software or by hardware alone (an electronic circuit).

[0015] Memory unit 18 is configured as storage such as read-only memory (ROM), a hard disk drive (HDD), or a solid-state drive (SSD). Memory unit 18 stores predefined software (a predefined program) for implementing the various functions of the components of the numerical controller 10 described above.

[0016] In this embodiment, the machining program 5 includes the shape of the material removal area of ​​the workpiece W (i.e., the contour shape of the cut workpiece W) and machining conditions for the cutting operation. The material removal area input unit 12 analyzes the machining program 5 and reads the shape of the material removal area of ​​the workpiece W. The machining condition input unit 14 analyzes the machining program 5 and reads the machining conditions for cutting. The machining program 5, the material removal area input unit 12, and the machining condition input unit 14 are now described in detail.

[0017] Fig. Figure 2A shows an example editing program for cutting to any shape with a contour that includes straight sections and a curved section, and Fig. 2B shows exemplary descriptions of the in Fig. 2A shown processing program. Fig. 3A and Fig. Figure 3B is a cross-sectional view illustrating the [effects] caused by the [component]. Fig. 2A shows the machining program specified shape of a removal area and a section (a half section above the axis of rotation Z) of the contour shape of a machined workpiece.

[0018] As in Fig. 2A, Fig. 2B and Fig. 3A shown G130 represents a command that generates a back-and-forth cutting operation parallel to the Z-axis by specifying a plurality of motion blocks N100 to N104. PS_ represents the sequence number of the first of the movement blocks (the movement block N100, which specifies a movement A→B). PE_ represents the sequence number of the last of the movement blocks (the movement block N104, which specifies a movement →C). U_ represents a finishing allowance for the finishing or final machining in the X direction. W_ represents a finishing allowance for the finishing or final machining in the Z direction. G00 represents a positioning command. G01 represents a cutting feed command, which is performed by linear interpolation. G02 represents a cutting feed command, which is carried out by circular interpolation in a clockwise direction (where R specifies the circular arc radius).

[0019] As in Fig. 2A and Fig. 3A shown The motion block N100 specifies a positioning shift from a shift start point A (Z = 20.0, X = 15.0) to a point B (Z = 20.0, X = 5.0), The motion block N101 specifies a displacement for the cutting feed, which is carried out by linear interpolation, from point B (Z = 20.0, X = 5.0) to position Z = 16.0 in the Z direction, The movement block N102 specifies a further displacement to the cutting feed, which is carried out by circular interpolation in a clockwise direction, to the position Z = 13.0 in the Z direction, where the circular arc radius R is 3.0. The motion block N103 specifies a further displacement to the cutting feed, which is achieved through linear interpolation, to the position (Z = 10.0, X = 10.0), and The motion block N104 specifies a further displacement to the cutting feed, which is carried out by linear interpolation, to the position X = 15.0 in the X direction, i.e. a displacement endpoint C (Z = 10.0, X = 15.0).

[0020] It should be prevented that the coordinate value of the X-axis decreases between points B and C.

[0021] As can be seen, motion blocks N100 to N104 show the contour shape of the material removal area R of the workpiece W, which is defined by one or more straight lines and curves, i.e., the contour shape of the cut workpiece W. If the finishing allowances (U, W) are specified, motion blocks N100 to N104 show the contour shape of the material removal area R of the finished workpiece W, i.e., the contour shape of the cut workpiece W. As can be seen, the machining program includes the contour shape of the material removal area R of the workpiece W to be removed by cutting, i.e., the contour shape of the cut workpiece W.

[0022] In this case, the material removal area input unit 12 analyzes the machining program and reads the shape of the material removal area R of the workpiece W to be removed by cutting operation from the contour shape of the material removal area in the machining program. For example, in the case of the Fig. 2A and Fig. 3A shows command G130, the cut area input unit 12 defines the interior of an area surrounded by points ABC as the cut area R from the movement blocks N100 to N104. Alternatively, it reads as in Fig. 2A and Fig. 3B shows that when the finishing allowances (U, W) are specified, the material removal area input unit 12 also takes the finishing allowances (U, W) from the machining program and shifts, i.e. offsets the read material removal area R in the X and Z directions by the corresponding finishing allowances.

[0023] Fig. Figure 4A shows an example editing program for cutting to any shape with a contour that includes straight sections and a curved section, and Fig. 4B shows exemplary descriptions of the in Fig. 4A shown in the processing program. As in Fig. 4A and Fig. As shown in diagram 4B, the motion blocks N100 to N104 can be provided in the form of a subroutine. PP_ represents a subroutine number that specifies motion blocks (the finished or finalized form). M99 indicates the end of the subroutine (return to the main program).

[0024] Referring to Fig. 2A and Fig. 2B contains the machining program machining conditions for cutting operations. D1_ represents the cutting depth achieved by the tool T during the cutting process in the forward direction (A→C direction), and D2_ represents the cutting depth achieved by the tool T during the cutting process in the return direction (C→A direction). F1_ represents the feed rate of the tool T during the cutting process in the forward direction (A→C direction) and F2_ represents the feed rate of the tool T during the cutting process in the return direction (CA direction). E_ represents the cutting direction at the end of the machining process. For example, E0 indicates that the cutting direction at the end of the machining process is not specified. For example, E1 indicates that the cutting direction at the end of the machining process is specified as the forward direction. For example, E2 indicates that the cutting direction at the end of the machining process is specified as the return direction. RR_ represents the amount of distance traveled by the tool T after the cutting process. TY_ specifies how the return or feed motion is to be performed during the cutting operation. For example, TY0 specifies that the return or feed motion is specified along the circumference of the cut area R. For example, TY1 specifies that the return or feed motion is specified by a line segment. For example, TY2 specifies that the return or feed motion is specified by a circular arc. UD_ represents the amount by which the tool T extends beyond the cut area R during the return motion.

[0025] In this case, the machining condition input unit 14 analyzes the machining program and reads the machining conditions for the cutting process. For example, in the case of the Fig. In the G130 command shown in Figure 2A, the machining condition input unit 14 reads the cutting depth made by tool T during the cutting operation in the forward direction from address D1 and the cutting depth made by tool T during the cutting operation in the return direction from address D2. The machining condition input unit 14 reads the feed rate of tool T during the cutting operation in the forward direction from address F1 and the feed rate of tool T during the cutting operation in the return direction from address F2. The machining condition input unit 14 reads the cutting direction at the end of the machining operation from address E.

[0026] The machining condition input unit 14 reads the distance T traveled by the tool after the cutting operation from address RR. Machining condition input unit 14 reads the specification for the return or infeed movement during the cutting operation and the path type from address TY. For example, in the case of TY0, machining condition input unit 14 reads the return or infeed movement along a straight path or a curved path along the circumference of the cut area R. For example, in the case of TY1, machining condition input unit 14 reads the return or infeed movement along any straight path (a line segment) on the plane defined by the Z-axis and the X-axis. For example, in the case of TY2, machining condition input unit 14 reads the return or infeed movement along any curved path (a circular arc) on the plane defined by the Z-axis and the X-axis.The machining condition input unit 14 reads the amount by which the tool T extends beyond the cutting area R during the return movement from address UD.

[0027] The processing conditions for cutting can be pre-stored in storage unit 18. Fig. Figure 5A shows an example editing program for cutting to any shape with a contour that includes straight sections and a curved section, and Fig. 5B is an example table for displaying tool identification information and machining conditions for machining with each of the tools. As in Fig. As shown in Figure 5B, storage unit 18 stores preliminary information that specifies a mapping between tool identification information and machining conditions for machining with each of the tools (D1, D2, F1, F2, E, TY, UD) in the form of a table. As shown in Fig. As shown in section 5A, the processing program 5 includes a specification T_ of the tool identification information.

[0028] In this case, the machining condition input unit 14 can analyze the machining program and read the machining conditions corresponding to the tool identification information from the storage unit 18. This can simplify the machining program 5.

[0029] Next, the motion generator 16 is described. The motion generator 16 generates a back-and-forth cutting operation based on the material removal area read by the material removal area input unit 12 and the machining conditions read by the machining condition input unit 14. Specifically, the motion generator 16 generates cutting operations of the tool T relative to the workpiece W in the forward and return directions such that the tool T overlaps with a section of the material removal area R yet to be cut, and such that the amount of this overlap does not exceed the cutting depth to be performed by the tool in the forward direction and the cutting depth to be performed by the tool in the return direction, which are contained in the machining conditions. The cutting operations in the forward and return directions are performed by respective straight paths parallel to the Z-axis.The straight paths are directed in opposite directions along the Z-axis.

[0030] Fig. Figures 6A to 6C illustrate exemplary cutting operations of a tool in the forward and return directions, generated by the motion generator. In each of Fig. 6A to 6C, the cutting operations in the forward direction are indicated by the solid lines, the cutting operations in the return direction are indicated by the dashed lines, and the cutting depth for each cutting operation in the forward direction is indicated by d1 and the cutting depth for each cutting operation in the return direction is indicated by d2.

[0031] For example, as in Fig. Figure 6A illustrates that if the specification (E) of the cutting direction at the end of the machining corresponds to the forward direction, the motion generator 16 alternately performs the cutting operations in the forward direction (the solid lines) with the cutting depth d1 and the cutting operations in the return direction (the dashed lines) with the cutting depth d2 in sequence from the bottom up.

[0032] For example, as in Fig. Figure 6B illustrates that if the specified cutting direction (E) at the end of the machining corresponds to the return direction, the motion generator 16 alternately performs the cutting operations in the return direction (the dashed lines) with the cutting depth d2 and the cutting operations in the forward direction (the solid lines) with the cutting depth d1 in sequence from the bottom up.

[0033] Alternatively, as in Fig. Figure 6C illustrates that if no cutting direction is specified (E) at the end of the machining process, the motion generator 16 alternately generates the cutting operations in the forward direction (the solid lines) with the cutting depth d1 and the cutting operations in the return direction (the dashed lines) with the cutting depth d2 in sequence from top to bottom.

[0034] If the cutting depth during the cutting operation is large enough for the tool to extend beyond the material removal area R, i.e., if the tool does not overlap with the portion of the material removal area still to be cut, the motion generator 16 terminates the creation of the cutting operation. If the cutting depth during the cutting operation is large enough for the tool to extend beyond the material removal area R, as in Fig. As illustrated in Figure 6C, the motion generator 16 adjusts the cutting depth during the cutting operation to be generated at the end so that the cutting depth is not large enough for the tool to extend beyond the material removal area R. If the cutting depth during the cutting operation is large enough for the tool to extend beyond the material removal area R, the motion generator 16 can adjust the cutting depth during the cutting operation so that the resulting excess is divided by the number of multiple cutting operations and the result is subtracted from the cutting depth in each cutting operation.

[0035] Fig. 7A and Fig. Figure 7B illustrates exemplary approximate movements generated by the motion generator. If, as in Fig. Figure 7A illustrates that if the Z-coordinate of the intersection point (empty circle) of the tool T and the section of the material removal area R yet to be cut is the same as the Z-coordinate of the starting point of movement A at the beginning of the machining process, there is no need for an approximation movement. However, if, as in Fig. Figure 7B illustrates that the Z-coordinate of the intersection point (empty star) of the tool T and the section of the removal area R to be cut at the beginning of the machining differs from the Z-coordinate of the starting point of the movement A, the motion generator 16 can generate an approximation movement in the Z direction from the machining starting point A to the intersection point (a positioning movement, a rapid traverse movement).

[0036] Fig. 8A and Fig. Figure 8B illustrates exemplary switching movements between forward and return cutting operations generated by the motion generator. In each of Fig. 8A and Fig. 8B The positions where the cutting process in the forward direction (the solid line) begins on the circumference of the removal area R are marked by the empty circles, and the positions where the cutting process in the forward direction (the solid line) ends on the circumference are marked by the filled circles. In each of Fig. 8A and Fig. 8B The positions where the cutting process in the return direction (the dashed line) starts on the circumference of the removal area R are marked by the empty stars and the positions where the cutting process in the return direction (the dashed line) ends on the circumference are marked by the filled stars.

[0037] As in Fig. 8A and Fig. Figure 8B illustrates that the motion generator 16 produces approach or approach movements along the circumference of the cutting area R in the direction corresponding to the positions where the cutting process begins in the forward direction (solid line) (the empty circles) and the positions where the cutting process begins in the return direction (dashed line) (the empty stars). The motion generator 16 produces approach or approach movements along the circumference of the cutting area R such that the positions where the cutting process ends in the forward direction (solid line) (the filled circles) are connected to the adjacent positions where the cutting process begins in the return direction (dashed line) (the empty stars).The motion generator 16 further generates approach movements or feed movements along the circumference of the cutting area R such that the positions at which the cutting process in the return direction (the dashed line) ends (the solid stars) are connected to the adjacent positions at which the cutting process in the forward direction (the solid line) begins (the empty circles). The feed movement refers to a movement that allows the tool T to be closer to the section of the cutting area R that is yet to be cut.

[0038] If the motion block in the direction A→B is assigned to a rapid traverse command, a movement along the direction A→B must only be an approach movement (a positioning movement, a rapid traverse movement). However, if the motion block in the direction A→B is assigned to a cutting feed command, a movement along the direction A→B must only be a positioning movement (a cutting feed movement). If the motion block in the direction B→C is assigned to a cutting feed command, a movement along the direction B→C must only be a positioning movement (a cutting feed movement).

[0039] Fig. 9A and Fig. Figure 9B illustrates exemplary restoring movements along the cut area, generated by the motion generator. To in Fig. To eliminate uncut sections as illustrated in Figure 9A, the motion generator can produce 16 cutting operations in the forward direction (the solid lines) and cutting operations in the return direction (the dashed lines), each involving a return motion (TY) along the perimeter of the cut area R, as shown in Figure 9A. Fig. Figure 9B illustrates this. The return movement refers to a movement that allows the tool T to be further away from the portion of the cut area R yet to be cut. The return movement can include a beyond movement (UD) along the perimeter of the cut area R. The beyond movement refers to a movement that allows the tool T to move beyond the portion of the cut area R yet to be cut after reaching it. In this case, a feed movement is again achieved by a movement in a direction opposite to the direction of the return movement.

[0040] Fig. Figure 10 illustrates exemplary distance movements and exemplary approach movements following the return movements generated by the motion generator. As in Fig. Figure 10 illustrates how the motion generator 16 can produce the cutting operations, each of which includes a retraction movement (RR) and approach movements after the return movement. The retraction movement refers to a movement that allows the tool T to be further away from the workpiece R. This can reduce interference between the tool T and the workpiece W. It can also prevent a cutting mark from being formed on the workpiece W.

[0041] Fig. 11A and Fig. Figure 11B illustrates exemplary return movements and exemplary delivery movements generated by the motion generator. As in Fig. Figure 11A illustrates that the motion generator can produce 16 cutting operations in the forward direction (the solid lines) and cutting operations in the return direction (the dashed lines), each involving a feed movement and a return movement (TY) along any straight path (a line segment) on the plane formed by the Z-axis and the X-axis. Alternatively, as shown in Fig. Figure 11B illustrates how the motion generator produces 16 cutting operations in the forward direction (solid lines) and cutting operations in the return direction (dashed lines), each involving a feed motion and a return motion (TY) through any curved path (circular arc) on the plane defined by the Z-axis and the X-axis. This can reduce the cutting load on the tool during the feed motion.

[0042] As described above, the motion generator 16 can generate the cutting operations, each of which includes a distance movement (RR) and a proximity movement after the return movement.

[0043] Fig. 12A and Fig. Figure 12B illustrates exemplary distance movements and exemplary approach movements at the end of the machining process, generated by the motion generator. If, as in Fig. 12A and Fig. Figure 12B illustrates the cutting depth when the cutting operation is large enough that the tool extends beyond the material removal area R, i.e., if the tool does not overlap with the portion of the material removal area yet to be cut, the motion generator 16 can generate a retraction motion (RR) and a proximity motion. If, as in Fig. Figure 12A illustrates that if the return movement is not included, the motion generator can generate 16 distance movements a, b, and c after the end of the machining movement. Alternatively, if, as in Fig. Figure 12B illustrates the return movement, which includes the motion generator 16, generating distance movements a, b, and c after the return movement. Distance movement a corresponds, for example, to a cutting feed. Distance movements b and c correspond, for example, to a rapid traverse, which allows the tool T to return to the starting point of the movement A.

[0044] As described above, the numerical controller of the first embodiment performs not only cutting operations in the forward direction but also cutting operations in the return direction. This can reduce the processing time.

[0045] The numerical controller of the first embodiment only needs to specify the shape of the machining area, i.e., the shape of the workpiece, in the machining program and can generate the positions and magnitudes of the movement for each of the cutting operations in the forward and return directions from this machining program, taking into account the depth of cut for each of the cutting operations in the forward and return directions. Thus, while reducing the cost of implementing programming support software, a numerical controller can generate cutting operations in the forward and return directions without using relatively effective programming support software such as computer-aided manufacturing (CAM). (Second embodiment)

[0046] In the first embodiment described above, cutting to any shape with a contour including straight sections and a curved section was described. In a second embodiment, a cutting process for removing a removal area with a shape having only a straight contour, i.e., a rectangular removal area, a removal area comprising a combination of a rectangular shape and a tapered shape (a right-angled triangular shape), or a tapered (right-angled triangular) removal area is described.

[0047] A numerical controller according to the second embodiment has a configuration analogous to that of the one in Fig. The numerical controller illustrated in Figure 1 is that of the first embodiment. The numerical controller according to the second embodiment includes a cutting area input unit 12, a machining condition input unit 14, and a motion generator 16, which function and operate in a manner that differs from that of the one in Figure 1. Fig. 1 illustrated numerical controller according to the first embodiment differs.

[0048] Fig. Figure 13A shows an example machining program for cutting to a shape with only one straight contour, i.e. a rectangular removal area. Fig. Figure 13B shows an exemplary machining program for cutting to a shape with only a straight contour, i.e., a cutting area that includes a combination of a rectangular shape and a tapered shape (a right-angled triangular shape), and Fig. Figure 13C shows an example machining program for cutting to a shape with only one straight contour, i.e. a tapered (right-angled triangular) removal area and Fig. 13D shows exemplary descriptions of the in Fig. The processing programs shown in sections 13A to 13C. Fig. Figures 14A to 14C are cross-sectional views illustrating the [effects] caused by the [component]. Fig. 13A shows the machining program and the specified shape of the removal area and a section (a half section above the axis of rotation Z) of the contour shape of a machined workpiece. Fig. 14D is a cross-sectional view to illustrate the [unclear] caused by the [unclear] in Fig. 13B shows the machining program and the specified shape of the removal area and a section (a half section above the Z axis of rotation) of the contour shape of the machined workpiece. Fig. 14E is a cross-sectional view to illustrate the [unclear] caused by the [unclear] in Fig. 13C shows the machining program specified shape of the removal area and a section (a half section above the axis of rotation Z) of the contour shape of the machined workpiece.

[0049] As in Fig. 13A, Fig. 13D and Fig. 14A shown G120 represents a command that creates a back-and-forth cutting operation parallel to the Z-axis by specifying a rectangular area. X_ represents the X-axis coordinate value (position) of point D diagonally to the starting point of the movement A, and Z_ represents the Z-axis coordinate value (position) of point D. U_ represents the magnitude of the displacement (movement) from the starting point of the movement A to point D (in other words, point B) in the X-axis direction, and W_ represents the magnitude of the displacement (movement) from the starting point of the movement A to point D (in other words, point C) in the Z-axis direction. The X-axis and Z-axis coordinate values ​​of the starting point of movement A are determined based on the previously stored shape of the workpiece W that is yet to be machined. As can be seen, the machining program includes the (rectangular) contour shape of the removal area R of the workpiece W to be removed by cutting processing, i.e. the contour shape of the cut workpiece W.

[0050] In this case, the material removal area input unit 12 analyzes the machining program and reads the shape of the material removal area R of the workpiece W to be removed by cutting operation from the (rectangular) contour shape of the material removal area in the machining program. For example, in the case of the Fig. 13A and Fig. In the G120 command shown in Figure 14A, the removal area input unit 12 defines the interior of the rectangular shape ABDC as the removal area R from the position (X, Z) of point D diagonally to the movement start point A, or the magnitudes of the movement (U, W) from the movement start point A to point D. The position of the movement start point A is determined based on the pre-stored shape of the raw material of the workpiece W that is still to be machined.

[0051] The machining program can include a finishing allowance. In the second embodiment, instead of the address (U, W) described above in the first embodiment, the address TY for specifying the return or feed movement includes a specification of a finishing allowance.

[0052] The cut area input unit 12 can also read the finishing allowance (TY) from the machining program and can prevent the cut area from including the finishing allowance. For example, in the case of the Fig. 13A, Fig. 14B and Fig. In the G120 command shown in Figure 14C, the cut area input unit 12 defines an area surrounded by a figure with a total of three vertices, such as point D and two points E and F, each of which is a predetermined distance d from point D in the X direction and in the Z direction, as the finishing allowance.

[0053] If the second position of the address (TY) assigned to the finishing allowance is one, the predetermined distance d is determined as the command value for the cutting depth D1 during the cutting operation in the forward direction. If the second position is two, the predetermined distance d is determined as the command value for the cutting depth D2 during the cutting operation in the return direction. If the first position of the address (TY) assigned to the finishing allowance is one, the finishing allowance is defined as having a triangular shape DEF, as shown in Fig. 14B illustrates, determined. However, if the first position of the address (TY) assigned to the finishing allowance is two, the finishing allowance is defined as an area enclosed by the line segments DE and DF and the circular arc EF, as shown in Fig. 14C illustrates, determines.

[0054] As in Fig. 13B, Fig. 13D and Fig. In 14D representation, the machining program can include the contour shape of the removal area R, which is specified as a shape formed by adding a tapered (right-angled triangular) shape to a rectangular shape. Q_ represents the amount of the taper from point B in the X-direction and R_ represents the amount of the taper from point C in the Z-direction.

[0055] In this case, the material removal area input unit 12 analyzes the machining program and reads the shape of the material removal area R of the workpiece W to be removed by cutting operation from the contour shape (a rectangular shape and tapered shapes such as right-angled triangular shapes) of the material removal area in the machining program. For example, in the case of the in Fig. 13B and Fig. In the G120 command shown in Figure 14D, the cut area input unit 12 reads the interior of the rectangular shape ABDC as a section of the cut area R from the position (X, Z) of point D diagonally to the starting point of movement A, or the amount of movement (U, W) from the starting point of movement A to point D as described above. Additionally, the cut area input unit 12 reads the interior of the right-angled triangular shape B-B'-D as another section of the cut area R from the address (Q) assigned to the amount of displacement from point B to point B' in the X-axis direction. Furthermore, the cut area input unit 12 reads the interior of the right-angled triangular shape C-C'-D as yet another section of the cut area R from the address (R) assigned to the amount of displacement from point C to point C' in the Z-axis direction.

[0056] In this way, the cut area input unit 12 reads an area obtained by combining the interior of the rectangular shape ABDC, the interior of the right-angled triangular shape B-B'-D and the interior of the right-angled triangular shape C-C'-D together as the cut area R.

[0057] As in Fig. 13C, Fig. 13D and Fig. As shown in Figure 14E, the machining program can include the contour shape of the removal area R, which is specified as a merely tapered (right-angled triangular shape).

[0058] In this case, the material removal area input unit 12 analyzes the machining program and reads the shape of the material removal area R of the workpiece W to be removed by cutting operation from the contour shape (a tapered shape such as a right-angled triangular shape) of the material removal area in the machining program. For example, in the case of the in Fig. 13C and Fig. 14E shown G120 command the cut area input unit 12 the interior of the right-angled triangular shape B-B'-D as the cut area R from the address (R) assigned to the amount of the displacement from point B (= point A) to point B' in the Z-axis direction.

[0059] As described above, the machining program includes machining conditions (D1, D2, F1, F2, E, RR, UD) for the cutting process. As described above, the machining condition input unit 14 analyzes the machining program and reads the machining conditions (D1, D2, F1, F2, E, RR, UD) for the cutting process. Then, as described above, the motion generator 16 creates a back-and-forth cutting operation based on the removal area read by the material removal area input unit 12 and the machining conditions read by the machining condition input unit 14.Specifically, the motion generator produces 16 cutting operations of the tool T relative to the workpiece W in the forward direction and in the return direction such that the tool T overlaps with a section of the removal area R that is still to be cut, and such that the amount of this overlap does not exceed the cutting depth to be made by the tool in the forward direction and the cutting depth to be made by the tool in the return direction, which are included in the machining conditions.

[0060] As can be seen from the preceding description, the numerical controller of the second embodiment also provides advantages analogous to those of the numerical controller of the first embodiment.

[0061] The embodiments of the present invention have been described above. However, the present invention should not be limited to the embodiments described above, and various changes and modifications can be made to the present invention. For example, in each of the preceding embodiments, the cutting operations generated by the motion generator 16 are carried out in the forward and return directions along respective straight paths parallel to the axis of rotation of the workpiece W (the Z-axis). The straight paths are directed in opposite directions along the axis of rotation of the workpiece W (the Z-axis). This, however, is only one example of the present invention.

[0062] For example, the cutting operations generated by the motion generator 16 can be performed in the forward and return directions along any straight paths on the plane formed by the workpiece's axis of rotation W (the Z-axis) and the axis perpendicular to the axis of rotation (the X-axis). The straight paths can be parallel to each other and can be directed in opposite directions along the workpiece's axis of rotation W (the Z-axis). Specifically, as in Fig. Figure 15 illustrates the cutting process in the forward and return directions by means of respective inclined paths with an angle of inclination θ (0° < θ < 90°) relative to the Z-axis. In this case - allow the ZX plane to be rotated clockwise by the angle θ and the cutting depths d1 and d2 to be replaced by d1cosθ and d2cosθ respectively, so that the same explanation as in the second embodiment described above applies to this example; and - the starting point for creating a path for a cutting operation must simply be the point furthest from point A in the X'-axis direction (the coordinate axis obtained by rotating the X-axis clockwise by the angle θ) (in which in Fig. 15 illustrated examples, point D).

[0063] For example, cutting operations in the forward and return directions can be performed along any curved paths on the plane defined by the workpiece's axis of rotation W (the Z-axis) and the axis perpendicular to the axis of rotation (the X-axis). The curved paths can be parallel to each other and can be directed in opposite directions along the workpiece's axis of rotation W (the Z-axis). Specifically, as in Fig. Figure 16 illustrates the cutting processes in the forward and return directions by means of respective paths along concentric circles around point A. In this case - the points of intersection of circular arcs around point A and the perimeter of the cutting area must be determined, and these points of intersection must be the starting point and the end point of each of the cutting operations in the forward direction and in the return direction.

[0064] The preceding embodiments illustrate an operating mode in which the tool is moved back and forth relative to the workpiece. However, this is merely an example of the present invention, which is also applicable to an operating mode in which the workpiece is moved back and forth relative to the tool. In other words, the present invention is also applicable to an operating mode in which the tool and the workpiece are moved back and forth relative to each other. In this case, the displacement of the tool simply needs to be replaced by a back-and-forth movement of the tool and the workpiece relative to each other.

[0065] The preceding embodiments illustrate an operating mode in which the workpiece is rotated. However, this is merely one example of the present invention, which is also applicable to an operating mode in which the tool is rotated relative to the workpiece. In other words, the present invention is also applicable to an operating mode in which the tool and the workpiece are rotated relative to each other. In this case, the rotation of the workpiece simply needs to be replaced by a rotation of the tool and the workpiece relative to each other. Examples of such machining include machining (end milling) performed with a rotation of a tool as in Fig. 17 illustrates how to carry it out. Fig. Figure 17 shows a view from the +Z direction (directly from above). The cutting operation in the forward direction (solid lines) is a downward cut (in the -X direction), and the cutting operation in the return direction (dashed lines) is an upward cut (in the +X direction).

[0066] Each of the preceding embodiments ( Fig. 2A, Fig. 3A, Fig. 3B, Fig. 4A and Fig. Figure 5A) illustrates an operating mode in which the machining program includes the contour shape of the removal area R of the workpiece W, which is defined by straight lines and a curve (five motion blocks N100 to N104). The total number of straight lines and curves is five. However, this is only one example of the present invention. The machining program can include the contour shape of the removal area R of the workpiece W, which is defined by one or more straight lines or curves. For example, as in Fig. 18A and Fig. Figure 18B illustrates the machining program, which includes the contour shape of the removal area R of the workpiece W, defined by only one curvature (a motion block N200). Fig. 18A specifies that the motion block N200 specifies a cutting feed displacement to position Z = 10.0 in the Z direction. This cutting feed displacement is achieved by circular interpolation in a clockwise direction with a circular arc radius R of 10.0. In other words, as in Fig. In Figure 18B, the motion block N200 illustrates the movement A→B→C in the form of a circular arc. Point B is the lowest point on the circular arc. List of reference symbols 5 Editing program 10 Numerical Controller 12 Abrasion area input unit 14 Processing condition input unit 16 motion generators 18 storage units 20 machine tools T tool W workpiece QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2005-288563

[0003]

Claims

[1] A numerical controller for a machine tool that performs cutting processing of a workpiece by both a cutting operation in a forward direction and a cutting operation in a return direction by relatively rotating a tool and the workpiece while relatively reciprocating the tool and the workpiece, the numerical controller comprising: a cutting area input unit configured to analyze a program for cutting processing and read a shape of a cutting area of ​​the workpiece to be removed by the cutting processing; a machining condition input unit configured to read machining conditions for the cutting processing, the machining conditions including at least a cutting depth to be made by the tool in the cutting process in the forward direction and a cutting depth to be made by the tool in the cutting process in the return direction; and a motion generator configured to generate the cutting operation in the forward direction and the cutting operation in the return direction based on the shape of the cutting area and the machining conditions such that the tool overlaps with a portion of the cutting area yet to be cut, and such that an amount of the overlap does not exceed the cutting depth to be made by the tool in the forward direction and the cutting depth to be made by the tool in the return direction. [2] Numerical controller according to claim 1, wherein the cutting operation in the forward direction and the cutting operation in the return direction generated by the motion generator are carried out by straight paths parallel to a rotational axis of the workpiece or any straight or curved paths on a plane formed by the rotational axis of the workpiece and an orthogonal axis orthogonal to the rotational axis, the tracks run parallel to each other, and the paths are directed in opposite directions along the axis of rotation of the workpiece. [3] Numerical controller according to claim 1, wherein the program includes a contour shape of the removal area specified as a right-angled triangular shape, a rectangular shape, or a shape formed by adding a tapered shape to a rectangular shape, and the cutting area input unit reads the shape of the cutting area from the contour shape of the cutting area in the program. [4] Numerical controller according to claim 1, wherein the program or a subprogram of the program includes a contour shape of the removal area which is defined by one or more straight lines or curves, and the cutting area input unit reads the shape of the cutting area from the contour shape of the cutting area in the program. [5] Numerical controller according to claim 1, wherein the program also includes a finishing or final processing allowance for finishing or final processing, the removal area input unit further reads the finishing allowance from the program and prevents the removal area from including the finishing allowance or offsets the removal area by the finishing allowance. [6] A numerical controller according to claim 1, wherein the machining conditions to be read by the machining condition input unit and used by the motion generator further include at least a feed rate of the tool and the workpiece relative to each other during the cutting process in the forward direction and a feed rate of the tool and the workpiece relative to each other during the cutting process in the return direction, an amount of distance for the tool and the workpiece relative to each other after each cutting operation, an infeed movement of the tool and the workpiece relative to each other during each cutting operation, a return movement of the tool and the workpiece relative to each other during each cutting operation, or whether a cutting direction at one end of the cutting processing is set as the forward direction or the return direction. [7] A numerical controller according to claim 6, wherein a path for each feed movement or a path for each return movement is a straight or curved path along a circumference of the removal area or any straight or curved path on a plane formed by a rotation axis of the workpiece and an orthogonal axis orthogonal to the rotation axis. [8] Numerical controller according to claim 1 or 6, wherein the program also includes the processing conditions, and the machining condition input unit analyzes the program and reads the machining conditions from the program. [9] A numerical controller according to claim 1 or 6, further comprising: a storage unit configured to store the identification information for machining conditions associated with the tool, wherein the program further includes the identification information for the tool, wherein the machining condition input unit reads the machining conditions corresponding to the identification information for the tool from the storage unit, wherein the identification information for the tool is read from the program. [10] A numerical controller according to claim 1, wherein the motion generator determines a predetermined point on a circumference of the removal area as the point at which the cutting operation in the forward direction starts or the point at which the cutting operation in the return direction starts, and produces an approach movement of the tool and the workpiece relative to each other in the direction of the point at which the cutting operation begins in the forward direction or the point at which the cutting operation begins in the return direction. [11] A numerical controller according to claim 1, wherein the cutting operation in the forward direction or the cutting operation in the return direction generated by the motion generator includes at least an infeed movement of the tool and the workpiece relative to each other in a direction in which the tool approaches the section of the removal area still to be cut, or a return movement of the tool and the workpiece relative to each other in a direction in which the tool moves away from the section of the removal area still to be cut. [12] The numerical controller according to claim 1, wherein the cutting operation in the forward direction or the cutting operation in the return direction generated by the motion generator includes a distance movement or an approach movement of the tool and the workpiece relative to each other in a direction in which the tool moves away from the workpiece. [13] The numerical controller according to claim 1, wherein, in a case where the tool does not overlap with the portion of the removal area yet to be cut, the motion generator generates a removal motion of the tool and the workpiece relative to each other in a direction in which the tool moves away from the workpiece.

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