CN112578731A

CN112578731A - Numerical controller and control method for numerical controller

Info

Publication number: CN112578731A
Application number: CN202010625949.6A
Authority: CN
Inventors: 高桥有礼
Original assignee: Brother Industries Ltd
Current assignee: Brother Industries Ltd
Priority date: 2019-09-30
Filing date: 2020-07-01
Publication date: 2021-03-30
Anticipated expiration: 2040-07-01
Also published as: CN112578731B; JP7192735B2; JP2021056827A

Abstract

The present invention relates to a numerical controller and a control method for the numerical controller. In the XY plane, a straight line path connecting the command position and the origin (O) is a path (R1), and a straight line path connecting the origin (O) and the ATC position (K) is a path (R2). The origin (O) is the origin of the movement range of the spindle head. The ATC position (K) is a position of a spindle head where the ATC device performs tool exchange of the spindle. The path (R3) is a path formed by connecting the path (R1) and the path (R2) in the cutting mode. The numerical controller moves the spindle head in a path (R3). The numerical control apparatus does not need to perform the in-position check at the end (origin O) of the path (R1). Therefore, the numerical controller can move the spindle head from the command position to the ATC position (K) in a shorter time.

Description

Numerical controller and control method for numerical controller

Technical Field

The present invention relates to a numerical controller and a control method for the numerical controller.

Background

The machine tool described in japanese patent laid-open publication No. 2006-106849 includes a tool changer. The machine tool moves the spindle head to the ATC position. The tool changer replaces the tool held by the spindle of the spindle head moved to the ATC position with the tool stored in the tool magazine. The tool changing position is set outside the origin, which is the end of each mechanical movement range of the XYZ axes. The movement path of the spindle head from the command position to the ATC position passes through the origin in the middle. Therefore, in the XY plane, the movement path of the spindle head is divided into a linear path connecting the command position and the origin, and a linear path connecting the origin and the ATC position.

Since the movement path of the spindle head passes through the origin, the numerical controller needs to perform an in-position (in-position) check at the end of the path, that is, near the origin. If the seating inspection is performed, the moving speed of the spindle head is reduced near the origin, and therefore, there is a problem that the tool changing time becomes long.

Disclosure of Invention

An object of the present invention is to provide a numerical controller and a method for controlling the numerical controller that can move between a command position and an ATC position in a short time.

The numerical controller according to claim 1 includes: a first movement control unit that moves a spindle head, which is provided with a spindle to which a tool is detachably attached, from a command position to an ATC position where the tool changer performs tool changing, in directions of an X axis, a Y axis, and a Z axis that are orthogonal to each other; a tool changer that changes the tool of the spindle by using the tool changer when the spindle head is moved to the ATC position by the first movement control unit; and a second movement control unit that moves the spindle head from the ATC position to the command position after the tool change by the tool changer is completed, wherein the first movement control unit and the second movement control unit include a path control unit that moves the spindle head along a path formed by connecting the first path and the second path in a cutting mode when a straight path connecting the command position and an origin of a movement range of the spindle head is set as a first path and a straight path connecting the origin and the ATC position is set as a second path in an XY plane defined by the X axis and the Y axis. The numerical control apparatus does not need to perform a seating check at the end of the first path while moving the spindle head from the command position to the ATC position along the first path and the second path. Therefore, the numerical controller can move the spindle head from the command position to the ATC position in a shorter time. Since the numerical controller connects the first path and the second path in the cutting mode, the spindle head can be moved from the command position to the ATC position while being moved to the inner peripheral side of the origin. Since the spindle head is once moved to the origin side, it can be safely moved to the ATC position without colliding with other members in the movement range. The same is true for the ATC position to the command position.

In the numerical controller according to claim 2, the path controller may connect the first path and the second path with a common time constant in the cutting mode. Therefore, the numerical controller can smoothly connect the first path and the second path.

In the numerical controller according to claim 3, the first path and the second path may be connected by linear interpolation, and the path controller may connect the first path and the second path with the longer one of the time constant of the first path and the time constant of the second path. Therefore, when the first path and the second path are linear interpolation, the numerical controller can connect the first path and the second path safely and smoothly.

In the numerical controller according to claim 4, the first path and the second path may be connected by nonlinear interpolation, the time constant of the first path may include a first time constant in the X-axis direction and a second time constant in the Y-axis direction, the time constant of the second path may include a third time constant in the X-axis direction and a fourth time constant in the Y-axis direction, and the path controller may connect the first path and the second path in the X-axis direction with the longer one of the first time constant and the third time constant and connect the first path and the second path in the Y-axis direction with the longer one of the second time constant and the fourth time constant. Therefore, when the first path and the second path are nonlinear interpolation, the numerical controller can connect the first path and the second path safely and smoothly.

The numerical controller according to claim 5 includes: a first movement control step of moving a spindle head, which is provided with a spindle to which a tool is detachably attached, from a command position to an ATC position where the tool is exchanged by a tool exchange device, the spindle head being movable in X, Y, and Z-axis directions orthogonal to each other; a tool changing step of changing a tool of the spindle by the tool changer when the spindle head is moved to the ATC position by the first movement control step; and a second movement control step of moving the spindle head from the ATC position to the command position after the tool exchange in the tool exchange step is completed, wherein the first movement control step and the second movement control step include a path control step of moving the spindle head along a path formed by connecting the first path and the second path in the cutting mode, when a straight path connecting the command position and an origin of a movement range of the spindle head is set as a first path and a straight path connecting the origin and the ATC position is set as a second path in an XY plane defined by the X axis and the Y axis. Therefore, the control method of the numerical controller achieves the effect described in claim 1.

Drawings

Fig. 1 is a perspective view of a machine tool 1.

Fig. 2 is a plan view of the machine tool 1.

Fig. 3 is a front view of the machine tool 1.

Fig. 4 is a right side view of the machine tool 1.

Fig. 5 is a sectional view taken along the line I-I shown in fig. 3.

Fig. 6 is a partially enlarged view in the region W shown in fig. 1.

Fig. 7 is a block diagram showing the electrical configurations of the numerical controller 50 and the machine tool 1.

Fig. 8 is a diagram showing the command position P, the origin O, ATC position K, and the paths R1, R2, R3 on the XY plane.

Fig. 9 is a diagram of processing the moving speed by a two-stage moving average filter.

Fig. 10 is an explanatory diagram of linear interpolation.

Fig. 11 is a graph showing a change in the moving speed when moving on a path R3 formed by connecting the path R1 with the R2 in the cutting mode.

Fig. 12 is an explanatory diagram of the nonlinear interpolation.

Fig. 13 is a flowchart of the ATC operation process.

Detailed Description

Embodiments of the present invention will be described. The following description uses the left and right, front and back, and up and down indicated by arrows in the drawings. The left-right direction, the front-back direction, and the up-down direction of the machine tool 1 shown in fig. 1 are the X-axis direction, the Y-axis direction, and the Z-axis direction of the machine tool 1, respectively. The machine tool 1 is a vertical machine tool. The main shaft 7 (see fig. 5) extends in the Z-axis direction. The machine tool 1 rotates a spindle 7 to which a tool is attached. The object to be cut is fixed to the turntable 11. The machine tool 1 moves the object to be cut and the spindle head 6 relative to each other in the X-axis, Y-axis, and Z-axis directions to machine the object to be cut. The numerical controller 50 (see fig. 7) controls the operation of the machine tool 1.

The structure of the machine tool 1 will be described with reference to fig. 1 to 4. The machine tool 1 includes a base 2, a column 5, a spindle head 6, a spindle 7 (see fig. 5), a table device 10, a tool changer 40 (hereinafter, tool changer is referred to as ATC device 40), and the like. The base 2 includes a base 20 (see fig. 4) on the rear side of the upper surface, and the base 20 includes an X-axis moving mechanism 101 on the upper surface. The X-axis movement mechanism 101 moves the carrier 12 (see fig. 1 and 4) in the X-axis direction. The X-axis moving mechanism 101 includes a pair of X-axis rails (not shown), an X-axis ball screw (not shown), an X-axis motor 21, and the like. The pair of X-axis rails extend in the X-axis direction and are provided on the upper surface of the pedestal portion 20. The X-axis ball screw extends along the X-axis direction and is arranged between the pair of X-axis rails. The carrier 12 moves along the X-axis rail. The carrier 12 includes a nut (not shown) at the bottom, and the nut is screwed to the X-axis ball screw. The X-axis motor 21 rotates the X-axis ball screw to move the carrier 12 in the X-axis direction together with the nut. The carrier 12 includes a Y-axis moving mechanism (not shown) on the upper surface. The Y-axis moving mechanism moves the column 5 in the Y-axis direction. The Y-axis moving mechanism includes a pair of Y-axis rails, a Y-axis ball screw, a Y-axis motor 24 (see fig. 7), and the like. The Y-axis ball screw extends in the Y-axis direction and is disposed between the pair of Y-axis rails. The column 5 moves along a pair of Y-axis rails. The column 5 includes a nut (not shown) at a lower portion thereof, and the nut is screwed with the Y-axis ball screw. The Y-axis motor 24 rotates the Y-axis ball screw, and the column 5 moves in the Y-axis direction together with the nut. The column 5 is moved in the X-axis direction by the carrier 12. The column 5 is moved in the X-axis direction and the Y-axis direction by the X-axis moving mechanism 101, the carrier 12, the Y-axis moving mechanism, and the like. The column 5 includes a Z-axis movement mechanism 103 (see fig. 2, 3, and 5) on the front surface. The Z-axis movement mechanism 103 supports the spindle head 6 so that the spindle head 6 can move in the Z-axis direction. The Z-axis moving mechanism 103 includes a pair of Z-axis rails 35, a Z-axis ball screw 36 (see fig. 5), a Z-axis motor 19, and the like. The Z-axis rails 35 and the Z-axis ball screw 36 extend in the Z-axis direction, and the Z-axis ball screw 36 is disposed between the Z-axis rails 35. The spindle head 6 moves along the Z-axis rail 35. The main shaft head 6 includes a nut 68 (see fig. 5) on the back surface, and the nut 68 is screwed to the Z-axis ball screw 36. The Z-axis motor 19 is supported on the upper front surface of the column 5. The Z-axis motor 19 rotates the Z-axis ball screw 36, and the spindle head 6 moves in the Z-axis direction together with the nut 68.

The internal structure of the spindle head 6 will be described. As shown in fig. 5, the spindle head 6 rotatably supports the spindle 7 therein, and the spindle 7 extends in the Z-axis direction. The spindle head 6 has a spindle motor 8 fixed to an upper portion thereof. The spindle 7 and a drive shaft 81 of the spindle motor 8 are coupled by a joint 25. The drive shaft 81 extends downward. The spindle 7 includes a mounting hole (not shown), a clamping mechanism portion (not shown), a pull rod 70, and the like. The mounting hole is provided at the lower end of the main shaft 7. The clamp mechanism is provided in a shaft hole (not shown) penetrating the center of the spindle 7 and above the mounting hole. The tie rod 70 is inserted into the shaft hole of the spindle 7 coaxially with the shaft hole of the spindle 7. The pull rod 70 is always urged upward by a spring. The holder holding the tool is attached to the attachment hole of the spindle 7. When the tool shank is mounted in the mounting hole, the clamping mechanism portion clamps the tool shank. When the clamping mechanism portion is pressed downward by the pull rod 70, the clamping mechanism portion releases the clamping of the tool holder. In the present embodiment, for convenience of explanation, the "shank" may be simply referred to as "tool".

The spindle head 6 includes a swing arm member 60 at the rear upper inner side. The swing arm member 60 has a substantially L-shape and is swingable about a support shaft 61. The support shaft 61 extends in the left-right direction inside the spindle head 6, and is fixed to both left and right side walls of the spindle head 6. The swing arm member 60 includes a vertical arm portion 63 and a horizontal arm portion 62. The vertical arm portion 63 extends obliquely upward from the support shaft 61 with respect to the column 5 side. The lateral arm portion 62 extends substantially horizontally forward from the support shaft 61. The pin 71 is provided to protrude orthogonally to the tie rod 70. The distal end portion 62A of the lateral arm portion 62 is formed into a bifurcated shape, and is disposed so as to sandwich the tie bar 70 from both left and right sides of the tie bar 70. The tip portion 62A can engage with the pin 71 from above the pin 71. When the swing arm member 60 is viewed from the left side, the tension spring (not shown) always biases the swing arm member 60 in the counterclockwise direction. Therefore, the swing arm member 60 always releases the downward pressing of the pin 71 by the arm 62.

As shown in fig. 5 and 6, the spindle head 6 includes a rod support 91 at an upper portion thereof on the ATC device 40 side. The lever support portion 91 supports the lever 92 so that the lever 92 can move in the front-rear direction. The rod 92 extends in the front-rear direction. The trailing arm portion 63 of the swing arm member 60 has a contact portion 63A on the upper end portion (tip end portion) right side surface. The contact portion 63A contacts the front end portion of the rod 92 and is constantly biased rearward by the tension spring. Therefore, the rear end portion of the lever 92 always protrudes rearward from the lever support portion 91 by a predetermined distance. When the rear end portion of the lever 92 is pressed forward, the swing arm member 60 swings clockwise about the support shaft 61, and presses the pull rod 70 against the spring force. The clamping mechanism releases clamping (hereinafter, referred to as unclamping) of the tool holder, and the tool holder can be removed from the mounting hole of the spindle 7.

As shown in fig. 1 and 2, the table device 10 is provided in front of the pedestal portion 20 of the pedestal portion 2. The table device 10 includes a rotary table 11 at an upper portion thereof. The rotary table 11 is provided to be rotatable about a rotation axis parallel to the Z-axis direction by a rotary table motor (not shown). The rotary table 11 includes trays P1 and P2 on the upper surface. The cutting target is fixed to one or both of the trays P1 and P2 by using a jig (not shown) or the like.

The structure of the ATC apparatus 40 will be described. As shown in fig. 1 and 4, the ATC device 40 is supported on the right side of the spindle head 6 by a pair of

support columns

31 and 32. The

pillars

31, 32 are provided on the right side of the upper surface of the base 2. The

support columns

31 and 32 are separated from each other in the front-rear direction and extend upward from the upper surface of the base portion 2. The ATC device 40 receives a control signal from the numerical controller 50, and replaces the tool attached to the attachment hole of the spindle 7 with the tool specified by the NC program. The ATC device 40 includes a main body 401, a tool magazine 41, and the like.

As shown in fig. 1 to 7, the main body 401 is a metal box having a substantially rectangular parallelepiped shape. The

pillars

31, 32 support the main body 401. The main body 401 includes an operation member 47, a swing shaft 43, a tool changer arm 44, an ATC motor 45, an ATC drive shaft (not shown), and the like. The operation member 47 is a rod-like member that is provided inside the main body portion 401 and extends parallel to the Z-axis direction. The upper end of the operation member 47 protrudes upward from an opening (not shown) provided in the upper surface of the main body 401. The lower end of the operating member 47 is pivotally supported so as to be swingable about a swing shaft 49 (see fig. 4). The swing shafts 49 extend in the left-right direction inside the main body 401, and are fixed to both left and right side walls of the main body 401. Therefore, the upper end portion of the operating member 47 can move in the front-rear direction about the swing shaft 49. The posture in which the operation member 47 extends parallel to the Z-axis direction is the basic posture. The operating member 47 has an abutting portion 48 (see fig. 2) on the upper end left side surface. The contact portion 48 has a substantially cylindrical shape protruding leftward. When spindle head 6 moves to an exchange position K (hereinafter referred to as "ATC position K" with reference to fig. 2) described later to exchange tools, the rear end of rod 92 is positioned in front of contact portion 48 of operating member 47.

The swing shaft 43 is formed in a cylindrical shape protruding downward from the lower portion of the body 401, and is supported to be rotatable around the axis. The swivel axis 43 extends parallel to the Z-axis direction. The swing shaft 43 is supported to be movable in the vertical direction. The tool changer arm 44 is orthogonal to the lower end of the swing shaft 43 and extends in the horizontal direction. The tool changer arm 44 includes a pair of holding

portions

44A and 44B at both ends. The

gripping portions

44A and 44B are formed in a hook shape having a C-shape in plan view, and engage with a groove portion (not shown) formed in the holder. The tool changer arm 44 includes a lock mechanism (not shown). The locking mechanism fixes the holder engaged with the

gripping portions

44A and 44B. The tool changer arm 44 fixes and releases the tool holder by a lock mechanism according to a rotation angle of an ATC motor 45 described later. Therefore, the

grip portions

44A and 44B detachably grip the holder.

The ATC motor 45 is supported at a substantially central portion in the front-rear direction of the upper surface of the main body 401 (see fig. 1 and 2). An ATC drive shaft (not shown) is provided inside the main body 401. The ATC motor 45 rotates an ATC drive shaft. A power transmission mechanism (not shown) is provided inside the main body 401, and moves the turning shaft 43 and the tool changer arm 44 up and down and rotates according to the rotation angle of the ATC drive shaft. The power transmission mechanism also swings and drives the operating member 47 forward from the state of the basic posture in accordance with the rotation angle of the ATC drive shaft. When the operating member 47 presses the rear end portion of the lever 92 forward, the tool holder can be removed from the mounting hole of the spindle 7. The power transmission mechanism rotates the turning shaft 43 and the tool changer arm 44 in accordance with the rotation angle of the ATC drive shaft. The magazine 41 is fixed to the right side surface of the body 401, and has a substantially elliptical shape that is long in the Y-axis direction in side view. The magazine 41 has a tool passage of a substantially elliptical shape on the inner side, and a plurality of tool pockets 41A are accommodated along the tool passage. The holder 41A detachably mounts the holder. The magazine 41 includes a tool changer (not shown) at a lower front side. The knife changing part is opened downwards. The tool changing section includes an opening/closing section (not shown). The opening and closing part drives the cutter changing part to open and close. The opening/closing section cylinder 89 (see fig. 7) is a driving source of the opening/closing section. The magazine motor 42 is supported on the upper front side of the magazine 41. The plurality of tool pockets 41A are moved in the tool passage by driving of the magazine motor 42. The numerical controller 50 drives the magazine motor 42 to convey and position the magazine 41A supporting the next tool to the tool changing section. In the present embodiment, the current tool refers to a tool currently attached to the spindle 7, and the next tool refers to a tool to be attached to the spindle 7 by changing the tool.

Referring to fig. 2, 3, and 8, the movement range of the spindle head 6 and the positional relationship of the origin O, ATC position K will be described. The coordinate position of the spindle head 6 is set to the coordinate position of the center of the lower end of the spindle head 6. The machine tool 1 sets a movement range for each of XYZ axes, which are movement axes of the spindle head 6. The movement range refers to a range in which the spindle head 6 can move when machining a cutting target. The region surrounded by the respective movement ranges of the XYZ axes is the movement range of the spindle head 6. The moving range of the X axis is the moving range of the X axis, the moving range of the Y axis is the moving range of the Y axis, and the moving range of the Z axis is the moving range of the Z axis. The machine tool 1 machines a cutting target of a pallet (in fig. 2, the pallet P1) on the spindle head 6 side out of the pallets P1 and P2 fixed to the rotary table 11. Therefore, the X-axis movement range and the Y-axis movement range may be set to be located on the upper surface of the pallet P1 on the spindle head 6 side of the turntable 11. The right end coordinate position of the ATC device 40 in the X-axis movement range is X0, and the left end coordinate position of the opposite side is Xmax. The coordinate position of the main spindle head 6 side, i.e., the rear end portion of the Y-axis movement range is Y0, and the coordinate position of the opposite side, i.e., the front end portion, is Ymax. The Z-axis movement range may be set in consideration of the height of the jig and the object to be cut fixed to the turntable 11. The upper end of the Z-axis movement range may be set to the position of the tool changer of the ATC device 40. The lower end of the Z-axis movement range may be set above the upper surface of the turntable 11. The coordinate position of the upper end of the Z-axis movement range is Z0, and the coordinate position of the lower end of the turntable 11 side is Zmax. The origin O of each of the transfer ranges in the XYZ axes is set to the end on the ATC device 40 side of the ends of each of the transfer ranges in the XYZ axes. The origin O (x, y, z) ═ 0, 0, 0. As shown in fig. 2 and 8, the Z axis is set as the origin O, and the X axis and the Y axis are set outside the movement range of each axis and near the origin O, with respect to the coordinate position of the ATC position K. The ATC position K (x, y, z) — (0.1, -0.1, 0) is set. When the spindle head 6 moves to the ATC position K during tool exchange, the rear end of the rod 92 is positioned at a position away from the front of the contact portion 48 of the operating member 47. In the machine tool 1, the ATC motor 45 is driven to swing the operation member 47 in the basic posture forward, and the lever 92 is pressed forward, thereby releasing the clamping of the tool attached to the spindle 7.

Referring to fig. 7, the electrical configurations of the numerical controller 50 and the machine tool 1 will be described. The numerical controller 50 includes a CPU51, a ROM 52, a RAM53, a storage device 54, an input interface 55, an output interface 56, and the like. The CPU51 performs overall control of the numerical controller 50. The ROM 52 stores various programs such as an ATC operation program. The ATC operation program is a program for executing ATC operation processing (see fig. 13) described later. The RAM53 stores various data when performing various processes. The storage device 54 is nonvolatile, and stores various data in addition to the NC program.

The machine tool 1 further includes an input unit 82 and an origin sensor 83. The holder lift sensor 84, the holder fall sensor 85, the opening/closing section opening sensor 86, the opening/closing section closing sensor 87, the air cylinder 88, the opening/closing section cylinder 89, and the identification sensor 58 are provided in the ATC device 40. The input unit 82 and the display unit 90 are provided on an operation panel (not shown). The input unit 82 accepts various inputs. The display unit 90 displays various screens. The origin sensor 83 detects the origin of the spindle 7 in the X, Y, and Z directions. The holder elevation sensor 84 detects the elevation of the holder 41A located at the knife changing portion. The holder lowering sensor 85 detects the lowering of the holder 41A located at the knife changing portion. The opening/closing section opening sensor 86 detects the opening state of the opening/closing section. The opening/closing section closing sensor 87 detects the closed state of the opening/closing section. The cylinder 88 is a driving source of a tool holder lifting mechanism (not shown). The holder lifting mechanism lifts the holder 41A at the tool changing position. The opening/closing section cylinder 89 is a driving source of an opening/closing section opening/closing mechanism (not shown). The opening/closing section opening/closing mechanism opens/closes the opening/closing section. The input unit 82, the origin sensor 83, the holder raising sensor 84, the holder lowering sensor 85, the opening/closing unit opening sensor 86, and the opening/closing unit closing sensor 87 are electrically connected to the input interface 55. The air cylinder 88, the opening/closing cylinder 89, and the display unit 90 are electrically connected to the output interface 56. The Z-axis motor 19, the spindle motor 8, the X-axis motor 21, the Y-axis motor 24, the tool magazine motor 42, and the ATC motor 45 are electrically connected to the output interface 56. The Z-axis motor 19 includes an encoder 19A, and the encoder 19A detects the rotation angle of the Z-axis motor 19. The spindle motor 8 includes an encoder 8A, and the encoder 8A detects the rotation angle of the spindle motor 8. The X-axis motor 21 includes an encoder 21A, and the encoder 21A detects the rotation angle of the X-axis motor 21. The Y-axis motor 24 includes an encoder 24A, and the encoder 24A detects the rotation angle of the Y-axis motor 24. The tool magazine motor 42 includes an encoder 42A, and the encoder 42A detects the rotation angle of the tool magazine motor 42. The ATC motor 45 includes an encoder 45A, and the encoder 45A detects the rotation angle of the ATC motor 45. The

encoders

19A, 8A, 21A, 24A, 42A, 45A are electrically connected to the input interface 55. The recognition sensor 58 includes a holder recognition plate 57, a light projecting element 58A, and a light receiving element 58B. The holder identification plate 57 is attached to the holder 41A and moves integrally with the holder 41A. The holder identification plate 57 includes a light-transmitting portion (not shown) having a different pattern for each holder 41A. The light projecting element 58A and the light receiving element 58B are provided in the cutter changer, and are disposed to face both side surfaces of the holder identification plate 57 of the holder 41A conveyed to the cutter changer. The light projecting element 58A is electrically connected to the output interface 56. The light-receiving element 58B is electrically connected to the input interface 55. The light emitted from the light projecting element 58A is input to the light receiving element 58B through the light transmitting portion of the holder identification plate 57. The CPU51 detects which of the tool pockets 41A is conveyed to the tool changing portion of the tool magazine 41 based on a signal from the light receiving element 58B. When detecting that the magazine 41A of the next tool is conveyed to the tool changer of the magazine 41, the CPU51 stops the driving of the magazine motor 42 and positions the next tool to the tool changer.

The ATC operation is explained. As shown in fig. 2 to 5, CPU51 moves spindle head 6 from command position P to ATC position K via origin O. The CPU51 drives the magazine motor 42 to convey and position the next tool to the tool changing section. The CPU51 opens the opening/closing section, tilts the holder 41A to which the next tool is attached vertically downward by 90 ° from the horizontal state, and lowers the next tool from the opening of the tool changing section. The holder 41A is set in a vertical state. The CPU51 drives the ATC motor 45 to rotate the ATC drive shaft. The tool changer arm 44 is rotated back from the standby position integrally with the rotating shaft 43, and the operating member 47 swings forward. The contact portion 48 of the operating member 47 is pressed forward while being in contact with the rear end portion of the lever 92. The lever 92 moves forward, and urges the contact portion 63A of the trailing arm portion 63 of the swing arm member 60 forward. The swing arm member 60 starts to rotate clockwise when viewed from the right side about the support shaft 61 against the biasing force of the tension spring. The lateral arm portion 62 engages with the pin 71 from above the pin 71, and presses the pull rod 70 downward against the biasing force of a spring provided inside the spindle 7. The pull rod 70 applies downward force to the clamping mechanism portion. The gripping portion 44A grips the current tool attached to the spindle 7, and the gripping portion 44B grips the next tool located at the tool changer. The clamping mechanism portion is changed from the clamped state to the unclamped state (the state where the tool is currently disengaged from the clamping mechanism portion inside the spindle 7). The tool changer arm 44 descends from the top dead center. The current tool is disengaged downward from the spindle 7, and the next tool is disengaged downward from the holder 41A. The tool changer arm 44 is lowered and swiveled back. The tool changer arm 44 reaches the bottom dead center and continues to rotate back. The swing shaft 43 and the tool changer arm 44 rise from the bottom dead center. The tool changer arm 44 is rotated back and raised. The current tool is interchanged with the next tool. The rotation of the tool changer arm 44 is stopped. The next tool is disposed below the spindle 7, and the current tool is disposed below the tool holder 41A of the tool changing portion. The tool changer 44 is raised, the next tool is inserted into the mounting hole of the spindle 7, the current tool is inserted into the tool case 41A, and the tool changer 44 reaches the top dead center. The next tool is mounted to the mounting hole of the spindle 7, and the present tool is mounted to the holder 41A. The tool changer arm 44 is rotated reversely integrally with the rotating shaft 43. The tool changer arm 44 stops rotating back at the standby position. A pair of

gripping portions

44A and 44B is disposed between the spindle 7 and the cutter changing portion. The CPU51 returns the holder 41A located at the tool changing portion of the magazine 41 from the vertical posture to the horizontal posture. The CPU51 closes the opening/closing unit and ends the ATC operation.

Referring to fig. 8, the movement path of the spindle head 6 during the ATC operation will be described. The CPU51 performs the seating check at the end position of the first path while moving the spindle head 6 along the two paths. The in-position check functions to check whether the spindle head 6 has indeed moved to the end position. During the ATC operation, CPU51 moves spindle head 6 from command position P to ATC position K via origin O, and executes ATC using ATC device 40. After executing ATC, CPU51 moves spindle head 6 from ATC position K to command position P via origin O. The path from the instruction position P to the origin O is R1, and the path from the origin O to the ATC position K is R2. If the spindle head 6 moves straight from the command position P toward the ATC position K without passing through the origin O, the spindle head 6 may come into contact with other obstacles located within the movement range. If the spindle head 6 passes through the origin O, contact with other obstacles located within the movement range can be prevented. If the CPU51 performs the seating check at the origin O, the moving speed of the spindle head 6 decreases near the origin O, and thus the ATC time becomes long. When the CPU51 moves the spindle head 6 along the paths R1 and R2 during the ATC operation, the spindle head 6 can be moved so as to pass through the origin O side without performing the seating inspection by connecting the path R1 to the R2 in the cutting mode described later. The path formed by connecting the path R1 with the path R2 in the cutting mode is R3. R3 is a path on the inner peripheral side with respect to the origin.

The acceleration/deceleration process when the spindle head 6 moves on the path will be described with reference to fig. 9. The CPU51 calculates a target position, a movement distance, a movement speed, a movement time, and the like for each of the X-axis, the Y-axis, and the Z-axis based on an interpolation command of the NC program. The interpolation command is a control command used when the axis is moved at a predetermined moving speed, and is a linear interpolation command or the like. Linear interpolation refers to a manner of moving along a straight line between two points. The CPU51 performs post-interpolation acceleration/deceleration processing. The post-interpolation acceleration/deceleration processing is processing for smoothing a speed change by passing the calculated moving speed for each axis at least twice through a moving average filter (FIR filter). Fig. 9 shows the result of processing the moving speed moving from X1 to X2 in the X-axis direction twice with the moving average filter. The acceleration/deceleration time constant (hereinafter referred to as a time constant) of the moving average filter corresponds to the number of samples averaged by the moving average filter. When the sampling time is 1msec and the time constant of the moving average filter is 10msec, the moving average filter sets the average of the previous 10 instructions including the current interpolation instruction as the current output. The time constant of the moving average filter (FIR1) of the first stage is t1, and the time constant of the moving average filter (FIR2) of the second stage is t 2. As a result of processing the moving speed with the two-stage moving average filter (FIR1, FIR2), the change in acceleration is constant or less, and therefore the tool is slowly accelerated to the maximum speed based on t1+ t2 (hereinafter referred to as t3), then slowly decelerated based on t3, and then stopped. Therefore, the numerical controller 50 processes the moving speed of each axis by using a plurality of moving average filters to absorb a rapid change in the moving speed.

Referring to fig. 8 to 12, the cutting mode will be described. The cutting mode is a mode in which the shaft is moved on two or more paths at a moving speed set by the NC program. Fig. 10 shows the movement distance L of the path moving in a linear interpolation manner from P0 toward P1 on the XY plane. The movement distance L is a distance obtained by combining the X-axis movement distance Lx and the Y-axis movement distance Ly. Since the movement is linear at the set movement speed from P0 to P1, the CPU51 calculates the time constant t common to the movement speed when the X-axis movement distance Lx is moved and the movement speed when the Y-axis movement distance Ly is moved so that the movement time of the X-axis movement distance Lx is the same as the movement time of the Y-axis movement distance Ly. The CPU51 calculates a time constant based on the movement distance (Lx, Ly) and the movement speed for the X axis and the Y axis so that the jerk is constant. The CPU51 calculates the movement time by dividing the movement distance (Lx, Ly) by the movement speed. The CPU51 fixes the longer one of the calculated X-axis and Y-axis movement times. The CPU51 sets the moving speed of the axis having the shorter moving time to the moving speed calculated by the following equation.

The moving speed of the axis with shorter moving time (moving speed of the axis with longer moving time) × (moving distance of the axis with shorter moving time/moving distance of the axis with longer moving time)

Therefore, for the axis whose moving time is shorter, the moving time and the moving speed change, and the CPU51 recalculates the time constant so that the jerk is constant in the same manner as described above. The CPU51 sets the recalculated time constant to the common time constant t. The CPU51 moves the spindle head 6 by acceleration/deceleration control with a time constant t that is common to the X-axis movement distance Lx and the Y-axis movement distance Ly. Therefore, the spindle head 6 moves linearly from P0 to P1.

Fig. 11 is a diagram showing velocity changes when the moving speed (speed 1) when moving on the path R1 in the X-axis direction and the moving speed (speed 2) when moving on the path R2 are processed by two-stage moving average filters (FIR1, FIR2), and the path R1 is connected to the path R2 in the cutting mode. The highest speed of the speed 1 and the speed 2 is the moving speed V. The common time constant for speed 1 and speed 2 is t 3. When speed 1 starts decelerating from the maximum speed, speed 2 starts accelerating. In a portion where the speed 1 and the speed 2 overlap, the spindle head 6 moves so as to turn inward near the origin O while maintaining the speed V constant. A path turning inward with respect to the paths R1 and R2 is R3 (see fig. 8). Therefore, the CPU51 can move the spindle head 6 on the path R3 at the set speed V. The change in the moving speed in the Y-axis direction is also the same as the change in the moving speed in the X-axis direction. Fig. 12 shows the movement distance L. The movement distance L is a path moving from P0 toward P1 in a nonlinear interpolation manner on the XY plane. When the movement of the Y-axis movement distance Ly is completed earlier than the movement of the X-axis movement distance Lx, the path from P0 to P1 is bent at P2. Since the movement is performed at the set movement speed from P0 to P1, the CPU51 calculates the movement speed for the movement X-axis movement distance Lx, the movement speed for the movement Y-axis movement distance Ly, and the time constant of each axis. The time constant of acceleration/deceleration control when the X axis moves by a distance Lx is tx. The time constant of acceleration/deceleration control when the Y axis moves by the distance Ly is ty. When two paths of the nonlinear interpolation are connected in the cutting mode, acceleration and deceleration control of each path has time constants tx and ty. The CPU51 needs to superimpose waveforms of the respective moving speeds (speed 1 and speed 2) so that the moving speeds when moving across two paths are constant for each axis, and combine the t3 portions (see fig. 11). In the nonlinear interpolation, if the axes are different, the time constant changes, so the CPU51 needs to determine the time constants tx and ty common to each other on each of the X-axis and the Y-axis of each path.

Referring to fig. 13, the ATC operation process will be described. When the NC program is interpreted and the ATC instruction is received, the CPU51 reads the ATC operation program from the ROM 52 and executes the present process. An example of the ATC instruction is "G100 _ T2_ X10_ Y10_ Z400". As shown in fig. 8, this command is a control command that moves from the current command position P (10, 10, 400) to the ATC position K via the origin O, and after ATC of the tool T2 by the ATC device 40 is completed, moves to the original command position P (10, 10, 400) via the origin O. When receiving the ATC command, the route R1 is the route of the current movement (hereinafter referred to as the current route). The path R2 is a path of the next movement (hereinafter referred to as a next path). The CPU51 calculates the X-axis movement distance Lx and the Y-axis movement distance Ly of the route R1 as the present route based on the command position P and the respective coordinate positions of the origin O (S11). The CPU51 calculates the X-axis movement distance Lx and the Y-axis movement distance Ly of the path R2 as the next path based on the respective coordinate positions of the origin O and the ATC position K (S12). The CPU51 determines whether the movement of the path is linear interpolation (S13). Switching between linear interpolation and non-linear interpolation is performed according to the switching parameter. The switching parameters are set by the user via the operation panel and stored in the storage device 54. The CPU51 refers to the switching parameter, and when the switching parameter is linear interpolation (S13: YES), the paths R1 and R2 are linear interpolation. The CPU51 calculates the present movement distance (hereinafter referred to as the present movement distance Lc) from the X-axis movement distance Lx and the Y-axis movement distance Ly on the present route R1 (S15). The present movement distance Lc is a straight distance from the command position P to the origin O. The CPU51 calculates a next movement distance (hereinafter referred to as a next movement distance Ln) from the X-axis movement distance Lx and the Y-axis movement distance Ly of the next path R2 (S16). The next movement distance Ln is a straight distance from the origin O to the ATC position K. The CPU51 calculates the time constant tc of the present movement distance Lc (S17). The time constant tc is common to the X-axis and the Y-axis. The CPU51 calculates the time constant tn of the next movement distance Ln (S18). The time constant tn is also common to the X and Y axes. The CPU51 selects the longer one of the time constants tc and tn (S19). The CPU51 moves on the present route R1 with the time constant selected through S19 (S27). The spindle head 6 accelerates from the command position P to reach the maximum speed V, and moves toward the origin O along the path R1. The CPU51 sets the next route R2 as the present route (S28). The CPU51 calculates the X-axis movement distance Lx and the Y-axis movement distance Ly of the path R2 (S29). The CPU51 may set the values calculated in S12 as the X-axis movement distance Lx and the Y-axis movement distance Ly of the path R2. The CPU51 changes the route R2 from the next route to the present route, and therefore needs to delete the next route. Therefore, the CPU51 sets the X-axis movement distance Lx and the Y-axis movement distance Ly of the next route to 0 (S30).

The CPU51 moves on the current route R2 with the longer time constant selected in S19 (S31). When the CPU51 starts decelerating from the maximum speed V by the acceleration/deceleration control of the path R1, the CPU starts accelerating by the acceleration/deceleration control of the path R2. The spindle head 6 moves along the path R3 so as to turn inward near the origin O, and maintains the speed V constant. The spindle head 6 moves to the ATC position K, decelerates, and stops at the ATC position K. For the Z axis, the CPU51 moves the spindle head 6 from the command position P to the ATC position K regardless of acceleration/deceleration control for the X axis and the Y axis.

The CPU51 determines whether the ATC is completed (S32). Since the spindle head 6 has not completed the ATC when it moves from the command position P to the ATC position K (S32: NO), the CPU51 executes the ATC using the ATC apparatus 40 (S33). After the ATC is completed, the CPU51 returns to S11, and similarly executes the processes of S11 to S13, S15 to S19, and S27 to S31 described above for the paths R2 and R1 from the ATC position K to the command position P. Therefore, the spindle head 6 moves in the reverse direction along the path R3 so as to turn inward near the origin O, decelerates, and stops at the command position P. For the Z axis, the CPU51 moves the spindle head 6 from the ATC position K to the command position P regardless of acceleration/deceleration control for the X axis and the Y axis. Since the ATC has been completed (S32: YES), the CPU51 ends the present process. Since the moving speed varies depending on the moving distance, the moving speed does not necessarily become the highest speed V.

When the paths R1 and R2 are not linear interpolation (S13: no), the CPU51 needs to set the time constant of the X axis and the time constant of the Y axis. The CPU51 calculates the X-axis time constant txc from the X-axis movement distance Lx of the present route R1 (S21). The CPU51 calculates the time constant txn of the X axis from the X axis movement distance Lx of the next path R2 (S22). The CPU51 calculates a Y-axis time constant tyc from the Y-axis movement distance Ly of the present route R1 (S23). The CPU51 calculates a time constant tyn of the Y axis from the Y axis movement distance Ly of the next path R2 (S24). The CPU51 sets the longer one of the time constants txc and txn as the time constant tx and the longer one of the time constants tyc and tyn as the time constant ty (S25). The CPU51 moves the spindle head 6 by the X-axis movement distance Lx of the current route R1 with the time constant tx and moves by the Y-axis movement distance Ly of the current route R1 with the time constant ty (S27). The spindle head 6 accelerates from the command position P to reach the maximum speed V, and moves toward the origin O. The CPU51 sets R2 as the next route as the present route (S28). The CPU51 calculates the X-axis movement distance Lx and the Y-axis movement distance Ly of the current route R2 (S29), and sets the X-axis movement distance Lx and the Y-axis movement distance Ly of the next route to 0 (S30). The CPU51 moves the spindle head 6 by the X-axis movement distance Lx of the current route R2 with the time constant tx and moves by the Y-axis movement distance Ly of the current route R2 with the time constant ty (S31). When the CPU51 starts decelerating from the maximum speed V by the acceleration/deceleration control of the path R1, the CPU starts accelerating by the acceleration/deceleration control of the path R2. The spindle head 6 moves so as to turn inward near the origin O, and maintains the speed V constant. The spindle head 6 moves to the ATC position K, decelerates, and stops at the ATC position K. For the Z axis, the CPU51 moves the spindle head 6 from the command position P to the ATC position K regardless of acceleration/deceleration control for the X axis and the Y axis. After the ATC by the ATC device 40 is completed, the CPU51 returns to S11, and executes the processes of S11 to S13, S21 to S25, and S27 to S31 for the routes R2 and R1 from the ATC position K to the command position P. Therefore, the spindle head 6 moves so as to turn inward near the origin O with respect to the paths R1 and R2, decelerates, and stops at the command position P. For the Z axis, the CPU51 moves the spindle head 6 from the ATC position K to the command position P regardless of acceleration/deceleration control for the X axis and the Y axis. Since ATC has been completed (S32: YES), the CPU51 ends the present process.

As described above, the numerical controller 50 of the present embodiment moves the spindle head 6 from the command position P to the ATC position K. The ATC position K is a position where ATC is performed by the ATC apparatus 40. The spindle head 6 is movable in mutually orthogonal X, Y, and Z-axis directions, and includes a spindle 7 to which a tool is detachably attached. When the spindle head 6 moves to the ATC position K, the numerical controller 50 performs ATC of the spindle 7 using the ATC device 40. After ATC by the ATC device 40 is completed, the numerical controller 50 moves the spindle head 6 from the ATC position K to the command position P. The path R1 is a straight path connecting the command position P and the origin O of the movement range of the spindle head 6. The path R2 is a straight line path connecting the origin O and the ATC position K. The path R3 is a path formed by connecting the path R1 with the path R2 in the cutting mode. The numerical controller 50 moves the spindle head 6 on an XY plane defined by the X axis and the Y axis along a path R3. Therefore, the numerical controller 50 does not need a seating check at the end (origin O) of the path R1. Therefore, the numerical controller 50 can move the spindle head 6 from the command position P to the ATC position K in a shorter time than when the seating inspection is performed. Since the numerical controller 50 connects the path R1 and the path R2 in the cutting mode, the spindle head 6 can be moved from the command position P to the ATC position K while turning at a position inside the origin O. Since the spindle head 6 is once moved to the origin O side, the spindle head 6 can be safely moved to the ATC position K without interfering with other members in the movement range. The same applies to the movement from ATC position K to command position P.

The numerical controller 50 connects the path R1 and the path R2 with a common time constant in the cutting mode, and therefore the path R1 and the path R2 can be smoothly connected.

When the path R1 and the path R2 are connected by linear interpolation, the numerical controller 50 connects the path R1 and the path R2 at the longer time constant t of the time constant tc of the path R1 and the time constant tn of the path R2. Therefore, the numerical controller 50 can safely and smoothly connect the linearly interpolated path R1 and the path R2.

When the path R1 and the path R2 are connected by nonlinear interpolation, the time constant of the path R1 includes a time constant txc in the X-axis direction and a time constant tyc in the Y-axis direction. The time constant of the path R2 includes a time constant txn in the X-axis direction and a time constant tyn in the Y-axis direction. The numerical controller 50 connects the path R1 to the path R2 with the longer time constant tx of the time constant txc and the time constant txn in the X-axis direction, and connects the path R1 to the path R2 with the longer time constant ty of the time constant tyc and the time constant tyn in the Y-axis direction. Therefore, the numerical controller 50 can safely and smoothly connect the path R1 of the nonlinear interpolation and the path R2.

In the above description, the CPU51 executing the processing of S11 to S31 in fig. 13 is an example of the first movement controller, the second movement controller, and the route controller according to the present invention. The CPU51 executing the process of S33 is an example of the cutter changer of the present invention. Time constant txc is an example of a first time constant of the present invention, time constant tyc is an example of a second time constant of the present invention, time constant txn is an example of a third time constant of the present invention, and time constant tyn is an example of a fourth time constant of the present invention.

The present invention is not limited to the above embodiment, and various modifications are possible. The machine tool 1 is a vertical machine tool, but may be a horizontal machine tool in which a spindle extends in the horizontal direction. The spindle head 6 moves along three axes of the X axis, the Y axis, and the Z axis, but may be moved relative to the object to be cut along three axes, and for example, the spindle head may be moved in the Z axis direction, and the table to which the object to be cut is fixed may be moved along two axes of the X axis and the Y axis.

The ATC apparatus 40 moves the spindle head 6 to the ATC position K, and rotates and moves up and down the turning shaft 43 and the tool changer arm 44 between the spindle 7 and the tool changing portion of the tool magazine 41 to thereby perform ATC of the spindle 7.

In the ATC operation process of the above embodiment, the spindle head 6 moves from the command position P to the ATC position K, and returns from the ATC position K to the command position P after ATC is completed.

Claims

1. A numerical controller is provided with:

a first movement control unit (51) that moves a spindle head (6), which is capable of moving in X-axis, Y-axis, and Z-axis directions that are orthogonal to each other, from a command position (P) to an ATC position (K) at which a tool is exchanged by a tool exchange device (40), the spindle head including a spindle (7) to which a tool is detachably attached;

a tool changer that changes the tool of the spindle by using the tool changer when the spindle head is moved to the ATC position by the first movement control unit; and

a second movement control unit that moves the spindle head from the ATC position to the command position after the tool changing by the tool changer is completed,

the numerical control apparatus is characterized in that,

the first movement control unit and the second movement control unit are provided with path control units,

when a straight line path connecting the command position and an origin (O) of a movement range of the spindle head is defined as a first path (R1) and a straight line path connecting the origin and the ATC position is defined as a second path (R2) in an XY plane defined by the X axis and the Y axis, the path control unit moves the spindle head along a path (R3) formed by connecting the first path and the second path in a cutting mode.

2. The numerical control apparatus according to claim 1,

the path control portion connects the first path and the second path with a time constant common to each other in the cutting mode.

3. The numerical control apparatus according to claim 2,

the first path and the second path are paths joined by linear interpolation,

the path control unit connects the first path and the second path with the longer one of the time constant of the first path and the time constant of the second path.

4. The numerical control apparatus according to claim 2,

the first path and the second path are paths joined by nonlinear interpolation,

the time constant of the first path is provided with a first time constant (txc) in the X-axis direction and a second time constant (tyc) in the Y-axis direction,

the time constant of the second path includes a third time constant (txn) in the X-axis direction and a fourth time constant (tyn) in the Y-axis direction,

the path control unit connects the first path and the second path in the X-axis direction with the longer one of the first time constant and the third time constant, and connects the first path and the second path in the Y-axis direction with the longer one of the second time constant and the fourth time constant.

5. A method for controlling a numerical controller, comprising:

a first movement control step of moving a spindle head, which is provided with a spindle to which a tool is detachably attached, from a command position to an ATC position where the tool is exchanged by a tool exchange device, the spindle head being movable in X, Y, and Z-axis directions orthogonal to each other;

a tool changing step of changing a tool of the spindle by the tool changer when the spindle head is moved to the ATC position by the first movement control step; and

a second movement control step of moving the spindle head from the ATC position to the command position after the tool exchange in the tool exchange step is completed,

the control method of the numerical controller is characterized in that,

the first movement control step and the second movement control step include a path control step in which,

and a controller configured to, in an XY plane defined by the X axis and the Y axis, move the spindle head along a path formed by connecting the first path and the second path in the cutting mode, when a straight path connecting the command position and an origin of a movement range of the spindle head is defined as a first path and a straight path connecting the origin and the ATC position is defined as a second path.