JP6051937B2 - Numerical controller - Google Patents

Description

  The present invention relates to a numerical control device.

  Conventionally, a numerical control device controls the operation of a machine tool. The machine tool includes a spindle head, a spindle, and a tool changer. The spindle head is provided so as to be able to move up and down along a column standing on the base, and supports the spindle in a rotatable manner. Patent Document 1 discloses a tool changer provided with a turret type tool magazine. The disk-shaped tool magazine is fixed to a frame provided on the column and is disposed on the front side of the spindle head. The tool magazine has a plurality of grip arms on its outer periphery and is rotatable. A gripping portion provided at the tip of the grip arm grips the tool so as to be detachable. When changing the tool, the spindle head rises past the Z-axis origin. The grip portion of the grip arm holds a used tool attached to the spindle. A tool holding mechanism provided inside the spindle head unclamps the tool mounted on the spindle. The spindle head rises further, removes the tool from the spindle, and rises to the ATC origin. Thereafter, the tool magazine turns, and the grip arm that holds the tool to be used next is moved directly below the main shaft. Thereafter, the spindle head is lowered, and the grip arm mounts the next tool to be used on the spindle. The tool holding mechanism clamps the tool mounted on the spindle. The spindle head descends to the workpiece machining area.

  The tool holding mechanism includes an unclamp member. The spindle head includes an unclamping operation member. The unclamp operation member includes an unclamp cam. A column is provided with a roller. The cam surface of the unclamp cam contacts and separates from the roller during the ascending stroke and descending stroke of the spindle head. The unclamp operation member swings and presses the unclamp member. The tool holding mechanism unclamps the tool mounted on the spindle.

JP 2012-206227 A

  The machine tool described in Patent Document 1 has a problem in that a large noise is generated during unclamping operation and tool mounting during tool replacement. The method of reducing the sound by adjusting the position of the tool changer is not a problem as long as the position adjustment is appropriate. However, if the position is shifted even a little, an excessive load is applied to the member with the tool changer. Accumulation of load leads to fatigue failure of the member.

  The objective of this invention is providing the numerical control apparatus which can aim at reduction of the sound and mechanical load which generate | occur | produce at the time of a tool exchange operation | movement.

A numerical controller according to claim 1 of the present invention includes a column provided on a base, a spindle head provided on the column so as to be movable up and down, a spindle rotatably supported on the spindle head and mounted with a tool, A machine tool comprising a frame provided in the column and proximate to the spindle head, and a tool magazine provided rotatably on the frame and capable of holding a plurality of tools, the spindle head comprising: When the tool magazine rises from the machine origin to the ATC origin at which the tool magazine can turn, the tool mounted on the spindle is removed and delivered to the tool magazine, and the tool magazine is positioned when the spindle head is located at the ATC origin. To position the desired tool so as to face the spindle, and when lowering the spindle head from the ATC origin to the machine origin, A numerical controller for mounting the desired tool in the spindle from the magazine, provided in the column, a head support mechanism for vertically movably supporting the spindle head, and control means for controlling the operation of the head supporting mechanism, wherein A tool holding mechanism that is provided on the spindle head and holds the tool attached to the spindle, and an unclamp that is provided on the spindle head and releases the tool attached to the spindle by pressing an unclamp member of the tool holding mechanism. A clamping operation member, an unclamping cam provided on the unclamping operation member, a column, and a rising stroke in which the spindle head rises from a machining position to the ATC origin, and a descent that descends from the ATC origin to the machine origin. In the process, the unclamping operation member is operated by contacting and separating the cam surface of the unclamping cam And a roller for the control means in each of said rising line as said downward stroke, after starting to move the spindle head at a first speed, the moving speed of the spindle head, said first speed First control means for switching to a second speed that is lower than the first speed, and after the first control means switches the movement speed to the second speed, the first speed is higher than the second speed. Second control means for switching to three speeds , wherein the first control means switches to the second speed at the position where the roller contacts the cam surface in the up stroke, and in the down stroke, the tool Is switched to the second speed at a position where the main shaft is mounted . In each of the upstroke and downstroke of the main shaft head, the moving speed of the spindle head is temporarily slower on the way the spindle head moves. Therefore, the numerical control device can reduce the noise generated at the time of tool change and reduce the load on the machine tool. The moving speed of the spindle head becomes high again after it becomes low. Therefore, the numerical control device can shorten the time required for tool change.

In upstroke of the main shaft head, the moving speed of the spindle head becomes slow at the position where the contact roller with the cam surface. Therefore, the numerical control device can reduce the collision noise generated when the roller contacts the cam surface in the ascending stroke of the spindle head, and can reduce the load applied to the cam surface and the roller.

In downstroke of the main shaft head, the moving speed of the spindle head becomes slower at a position where the tool is attached to the spindle. Therefore, the numerical control device can reduce the impact sound generated when the tool is mounted on the spindle during the descending stroke of the spindle head, and can reduce the load on the spindle and the tool changer.

1 is a perspective view of a machine tool 1. FIG. 3 is a partially broken view around the spindle head 7. FIG. 3 is a block diagram showing an electrical configuration of the machine tool 1 and the numerical control device 30. The flowchart of a tool exchange process. The figure which shows the raising / lowering operation | movement of the spindle head 7 in a tool exchange operation | movement. A partially cutaway view around the spindle head 7 of Z490. The partially broken view around the spindle head 7 of Z500. FIG. 10 is a partially cutaway view around the spindle head 7 of Z510. A partially broken view around the spindle head 7 at Z615 (ATC origin). The graph which shows the relationship between the Z-axis coordinate of the spindle head 7 at the time of the spindle head 7 raising, and a feed rate. The graph which shows the relationship between the Z-axis coordinate of the spindle head 7, and a feed rate at the time of the spindle head 7 descent. The graph which shows the relationship between the Z-axis coordinate and feed speed which were created by combining each graph of FIG. 10 and FIG. 11 (modification example).

  An embodiment of the present invention will be described with reference to the drawings. In the following description, the diagonally lower left, the diagonally upper right, the right, and the left in FIG. 1 are the front, rear, right, and left of the machine tool 1, respectively. The left-right direction, the front-rear direction, and the up-down direction of the machine tool 1 are the X-axis direction, the Y-axis direction, and the Z-axis direction of the machine tool 1, respectively.

  The structure of the machine tool 1 will be described with reference to FIG. The machine tool 1 includes a base 2, a machine body 3, a table 10, a tool changer 20, and the like. The base 2 is a substantially rectangular parallelepiped base made of iron. The machine body 3 is provided at the upper rear of the base 2 and cuts a work (not shown) held on the upper surface of the table 10. The table 10 is provided at the upper center of the base 2 and can be moved in the X-axis direction and the Y-axis direction by an X-axis motor 53, a Y-axis motor 54 (see FIG. 3), and a guide mechanism (not shown). The tool changer 20 is fixed to a frame 8 provided on the upper part of the machine main body 3, and the tool 4 mounted on the main shaft 9 of the machine main body 3 is exchanged with another tool.

  The machine tool 1 includes an operation panel (not shown). The operation panel includes an input unit 24 and a display unit 25 (see FIG. 3). The operator inputs an NC program, a tool type, tool information, various parameters, and the like through the input unit 24. When the operator operates the input unit 24, the display unit 25 displays various input screens or operation screens.

  The configuration of the machine body 3 will be described with reference to FIG. The machine body 3 includes a column 5, a spindle head 7, a spindle 9, a control box 6, and the like. The column 5 is erected on the upper rear side of the base 2. The spindle head 7 can move up and down in the Z-axis direction along the front surface of the column 5. The main shaft 9 is rotatably supported inside the main shaft head 7. The spindle 9 is equipped with a tool holder 17 (see FIG. 2) and rotates at high speed by driving a spindle motor 52 (see FIGS. 2 and 3). The tool holder 17 holds the tool 4. The control box 6 stores a numerical control device 30 (see FIG. 3). The numerical control device 30 controls the operation of the machine tool 1.

  As shown in FIG. 2, the spindle head 7 is raised and lowered in the Z-axis direction by a Z-axis moving mechanism (corresponding to the head support mechanism of the present invention) provided on the front surface of the column 5. The Z-axis moving mechanism includes a pair of Z-axis linear guides (not shown), a Z-axis ball screw 26 (see FIG. 2), and a Z-axis motor 51 (see FIG. 3). The Z-axis linear guide extends in the Z-axis direction and guides the spindle head 7 in the Z-axis direction. The Z-axis ball screw 26 is disposed between a pair of Z-axis linear guides and is rotatably provided by an upper bearing portion 27 and a lower bearing portion (not shown). The spindle head 7 includes a nut 29 (see FIG. 2) on the back surface. The nut 29 is screwed into the Z-axis ball screw 26. The Z-axis motor 51 rotates the Z-axis ball screw 26 in the forward and reverse directions. Therefore, the spindle head 7 moves in the Z-axis direction together with the nut 29. The spindle head 7 includes a spindle motor 52 at the top.

  The internal structure of the spindle head 7 will be described with reference to FIG. The spindle head 7 rotatably supports the spindle 9 inside the lower front part. The main shaft 9 has a rotation axis in the vertical direction. The main shaft 9 is connected to the drive shaft of the main shaft motor 52 via a coupling 23. Therefore, the main shaft 9 is rotated by the rotation drive of the main shaft motor 52. The main shaft 9 includes a tapered hole 18, a holder clamping member 19, and a draw bar 81. The tapered hole 18 is provided at the tip (lower end) of the main shaft 9. The holder clamping member 19 is provided above the tapered hole 18. The draw bar 81 is provided by being coaxially inserted into a shaft hole passing through the center of the main shaft 9.

  As shown in FIG. 2, the tool holder 17 holds the tool 4 on one end side, and includes a taper mounting portion 17A and a pull stud 17B on the other end side. The taper mounting portion 17A has a conical shape. The pull stud 17B protrudes in the axial direction from the top of the taper mounting portion 17A. The tapered mounting portion 17A is mounted in the tapered hole 18 of the main shaft 9. When the taper mounting portion 17A is mounted in the taper hole 18, the holder clamping member 19 clamps the pull stud 17B. When the draw bar 81 presses the holder holding member 19 downward, the holder holding member 19 releases the pull stud 17B.

  The spindle head 7 is provided with a crank lever 60 inside the rear upper part. The crank lever 60 is substantially L-shaped and can swing around a support shaft 61. The spindle 61 is fixed in the spindle head 7. The crank lever 60 includes a vertical lever 63 and a horizontal lever 62. The longitudinal lever 63 extends obliquely upward from the support shaft 61 to the column 5 side, bends upward at the intermediate portion 65, and further extends upward. The lateral lever 62 extends substantially horizontally from the support shaft 61 to the front of the column 5. The front end of the lateral lever 62 can be engaged from above with a pin 58 projecting perpendicularly to the draw bar 81. The vertical lever 63 includes a plate cam body 66 on the back surface of the upper end portion. The plate cam body 66 has a cam surface on the column 5 side. The cam surface of the plate cam body 66 can be brought into and out of contact with a cam follower 67 fixed to the upper bearing portion 27. The cam follower 67 slides on the cam surface of the plate cam body 66. A tension coil spring (not shown) is elastically provided between the longitudinal lever 63 and the spindle head 7. When the crank lever 60 is viewed from the right side, the tension coil spring constantly urges the crank lever 60 clockwise. Therefore, the crank lever 60 always releases the downward pressing of the pin 58 by the lateral lever 62.

  With reference to FIGS. 6 to 9, the operation of detaching the tool holder 17 from the tapered hole 18 of the main shaft 9 will be described. As shown in FIG. 6, the spindle head 7 ascends with the taper mounting portion 17 </ b> A of the tool holder 17 installed in the tapered hole 18 of the spindle 9. The plate cam body 66 provided on the crank lever 60 contacts the cam follower 67 and slides. As shown in FIG. 7, the cam follower 67 slides along the cam shape of the plate cam body 66. The crank lever 60 rotates counterclockwise around the support shaft 61 when viewed from the right side. The lateral lever 62 engages with the pin 58 from above and presses the draw bar 81 downward. The draw bar 81 urges the holder holding member 19 downward. Therefore, the holder holding member 19 releases the holding of the pull stud 17B. As shown in FIGS. 8 and 9, the tool holder 17 can be removed from the tapered hole 18 of the main shaft 9.

  On the contrary, when the taper mounting portion 17A of the tool holder 17 is mounted in the taper hole 18 of the main shaft 9, the taper hole of the tool holder 17 is inserted into the taper hole 18 of the main shaft 9 as shown in the order of FIGS. With the mounting portion 17A inserted, the spindle head 7 is lowered. The plate cam body 66 provided on the crank lever 60 slides on the cam follower 67. A cam follower 67 slides along the cam shape of the plate cam body 66. The crank lever 60 rotates clockwise around the support shaft 61 when viewed from the right side. Therefore, the lateral lever 62 is separated from the pin 58 to release the downward pressing of the draw bar 81. The draw bar 81 releases the downward biasing of the holder clamping member 19, and the holder clamping member 19 clamps the pull stud 17B. As shown in FIG. 6, the mounting of the taper mounting portion 17 </ b> A of the tool holder 17 is completed in the taper hole 18 of the main shaft 9.

  The structure of the tool changer 20 will be described with reference to FIG. The tool changer 20 includes a tool magazine 21. The tool magazine 21 is a turret type. The tool magazine 21 includes a magazine base 71 and a plurality of grip arms 90. The magazine base 71 has a disk shape. The plurality of grip arms 90 are provided so as to be swingable in the front-rear direction along the outer periphery of the magazine base 71. The magazine support 45 is fixed to the frame 8. The frame 8 is fixed to the column 5 and arranged close to the spindle head 7. The magazine support 45 supports the support shaft 75 in a rotatable manner. The support shaft 75 extends obliquely downward with respect to the front of the machine tool 1. The support shaft 75 rotatably supports the magazine base 71. The magazine base 71 is arranged with the front side facing the front of the machine tool 1.

  The structure of the magazine base 71 will be described with reference to FIG. The magazine base 71 includes a boss portion 73 and a collar portion 72. The boss 73 is cylindrical. The support shaft 75 is inserted into the boss portion 73. The flange portion 72 is provided on the front end side of the outer peripheral surface of the boss portion 73 so as to be orthogonal to the axial direction. The boss 73 fixes the indexing disc 77 to the rear end. The indexing disc 77 has a plurality of cam followers (not shown) on the back side (surface facing the spindle head 7) with the support shaft 75 as the center. The plurality of cam followers are arranged corresponding to the positions of the plurality of grip arms 90, respectively.

  The casing 41 is fixed to the upper part of the magazine support 45. The casing 41 stores the rotation index mechanism. The rotation index mechanism has a plurality of gears and a cam (not shown). The magazine motor 55 is fixed to the upper part of the casing 41. The rotation shaft of the magazine motor 55 is connected to the rotation index mechanism. The plurality of cam followers of the indexing disc 77 are fitted into cam grooves (not shown) formed in the cam of the rotary indexing mechanism. Therefore, the indexing disc 77 can index one of the plurality of grip arms 90 and move to the lowest position of the magazine base 71.

  The magazine base 71 fixes a plurality of fulcrum stands 82 along the outer periphery of the back surface. The fulcrum stand 82 supports the grip arm 90 so as to be swingable about the pivot shaft 85. The grip arm 90 includes a grip portion 91 at one end. The grip part 91 can grip a tool. The grip arm 90 rotatably supports the cam follower 93 in the vicinity of the pivot shaft 85 toward the spindle head 7 side. The cam follower 93 slides on the inclined surface of the cam body 11 fixed to the front surface of the spindle head 7 as the spindle head 7 moves up and down. The grip arm 90 swings around the pivot shaft 85. The grip portion 91 of the grip arm 90 indexed to the lowest position of the magazine base 71 can swing between the proximity position and the retracted position. The proximity position is a position that is close to and faces the main shaft 9. The retreat position is a position away from the main shaft 9 forward.

  The grip arm 90 holds the steel ball 92 at the other end opposite to the grip portion 91 in a state where the steel ball 92 is urged outward by a compression coil spring (not shown). The boss portion 73 extrapolates a cylindrical grip support collar 80 around which a guide surface 83 having an arcuate cross section is provided. A part of the steel ball 92 protruding and retracting from the other end of the grip arm 90 elastically contacts the guide surface 83 of the grip support collar 80. The guide surface 83 guides the other end side of the grip arm 90. Therefore, the grip arm 90 can swing stably.

  The guide surface 83 includes a first notch groove 98 and a second notch groove 99. The first notch groove 98 is provided on the front side of the magazine base 71 in the guide surface 83. The second notch groove 99 is provided on the guide head 83 on the spindle head 7 side. When the steel ball 92 is fitted in the first notch groove 98, the grip arm 90 maintains the posture in a state where the grip 91 is moved to the close position. When the steel ball 92 is fitted in the second notch groove 99, the grip arm 90 maintains the posture in a state where the grip portion 91 is moved to the retracted position.

The electrical configuration of the numerical control device 30 will be described with reference to FIG. The numerical control device 30 includes a CPU 31, a ROM 32, a RAM 33, a nonvolatile storage device 34, an input / output unit 35, drive circuits 51A to 55A, and the like. The CPU 31 controls the numerical control device 30. The ROM 32 stores a control program, a tool change program, and the like. The control program is for analyzing and executing the NC program. The tool change program is for executing a tool change process (see FIG. 4) described later. RAM 3 3 temporarily stores the various data during various processes running. The non-volatile storage device 34 stores a plurality of NC programs and the like registered by the operator through the input unit 24. The NC program is composed of a plurality of blocks including various control commands, and controls various operations including axis movement of the machine tool 1, tool change, and the like in units of blocks.

  The drive circuit 51A is connected to the Z-axis motor 51 and the encoder 51B. The drive circuit 52A is connected to the spindle motor 52 and the encoder 52B. The drive circuit 53A is connected to the X-axis motor 53 and the encoder 53B. The drive circuit 54A is connected to the Y-axis motor 54 and the encoder 54B. The drive circuit 55A is connected to the magazine motor 55 and the encoder 55B. The drive circuits 51A to 55A receive commands from the CPU 31 and output drive currents to the corresponding motors 51 to 55, respectively. The drive circuits 51A to 55A receive feedback signals from the encoders 51B to 55B and perform position and speed feedback control. The feedback signal is a pulse signal. The input / output unit 35 is connected to the input unit 24 and the display unit 25, respectively.

  The user can select one NC program from among a plurality of NC programs with the input unit 24. The CPU 31 displays the selected NC program on the display unit 25. The CPU 31 controls the operation of the machine tool 1 based on the NC program displayed on the display unit 25.

  A tool change process executed by the CPU 31 will be described with reference to the flowchart of FIG. 4 and FIGS. In the following description, the Z-axis mechanical origin is referred to as the Z-axis origin. The machine origin is a position where the X-axis and Y-axis machine coordinates are zero, and the Z-axis machine coordinate is an upper limit position where the workpiece can be machined. In this embodiment, for convenience of explanation, Z180 is a machining position, Z480 is a Z-axis origin, and Z615 is an ATC origin. Further, Z490 is a position where the plate cam body 66 comes into contact with the cam follower 67 when the tool change of the spindle head 7 is raised, and Z510 is a position where the tool holder 17 comes into contact with the spindle 9 when the tool change of the spindle head 7 is lowered. In FIG. 5, the thick arrow indicates the movement of the spindle head 7 at the highest speed, and the thin arrow indicates the movement of the spindle head 7 at the low speed, and the acceleration process to the maximum speed and the deceleration process to the low speed are not shown. An example of the maximum speed is 50 m / min. An example of a low speed is 20 m / min. The Z-axis is based on the upper surface of the table 10 as a reference (0). Z490 indicates a position 490 mm higher than the upper surface of the table 10.

  The tool change process executes a tool change operation. The tool change operation is executed in the order of the upward stroke, the tool magazine turning, and the downward stroke.

  When the CPU 31 reads the control command instructing the tool change while the NC program is being executed for each block by the control program, the CPU 31 reads the tool change program from the ROM 32 and executes this processing.

[Rising process]
The CPU 31 starts an orientation operation (S1). The orientation operation is an operation for stopping the rotation angle position of the spindle 9 at a position where the tool is changed. The CPU 31 rotates the Z axis motor 51. The CPU 31 starts to raise the spindle head 7 from the machining position Z180 at the highest speed (S2). As shown in FIGS. 5 and 10, the spindle head 7 moves up the section 101 at the highest speed. A section 101 is a section from Z180 to Z465.

  The CPU 31 determines whether or not the spindle head 7 has reached Z465 (S3). Until Z465 is reached (S3: NO), the process returns to S3 and the spindle head 7 continues to rise at the highest speed. When Z465 is reached (S3: YES), the CPU 31 starts decelerating (S4). The spindle head 7 begins to decelerate from the highest speed. When the rising speed of the spindle head 7 is decelerated to a low speed, the CPU 31 maintains the rising speed of the spindle head 7 at a low speed (S5). In the present embodiment, when the spindle head 7 reaches Z490, the rising speed of the spindle head 7 becomes low. As shown in FIGS. 5 and 10, the spindle head 7 rises while decelerating from the maximum speed to the low speed in the section 102. A section 102 is a section from Z465 to Z490. The spindle head 7 passes through the Z-axis origin (Z480).

  The CPU 31 determines whether or not the spindle head 7 has reached Z490 (S6). Until Z490 is reached (S6: NO), the process returns to S6 and continues to raise the spindle head 7 at a low speed. When Z490 is reached (S6: YES), the plate cam body 66 contacts the cam follower 67 as shown in FIG. The spindle head 7 is rising at a low speed. Therefore, the machine tool 1 can reduce the collision sound generated when the plate cam body 66 abuts against the cam follower 67. As will be described later, the lateral lever 62 engages with the pin 58 at the same time as the plate cam body 66 contacts the cam follower 67. A collision noise is also generated when the lateral lever 62 is engaged with the pin 58. As described above, since the spindle head 7 is rising at a low speed, the collision noise is also reduced. The machine tool 1 can reduce both the moment when the plate cam body 66 abuts the cam follower 67 and the moment when the lateral lever 62 engages with the pin 58, so the plate cam body 66 and the cam follower 67, and the lateral lever 62 and the pin. The load on 58 can be reduced.

  When Z490 is reached (S6: YES), since the plate cam body 66 is already in contact with the cam follower 67, the CPU 31 rises at the highest speed (S7). As shown in FIGS. 5 and 10, the spindle head 7 accelerates from the low speed in the section 103 and rises at the maximum speed. A section 103 is a section from Z490 to Z573.

  As shown in the order of FIGS. 6 to 8, the cam follower 93 slides on the inclined surface of the cam body 11 fixed to the front surface of the spindle head 7 downward from the upper side as the spindle head 7 moves up. The grip arm 90 swings around the pivot shaft 85. The grip portion 91 of the grip arm 90 that is indexed to the lowest position of the magazine base 71 moves to a position close to the main shaft 9. The grip portion 91 grips the tool holder 17 attached to the main shaft 9.

  On the other hand, as shown in the order of FIGS. 6 to 8, the plate cam body 66 contacts the cam follower 67 and slides upward. The crank lever 60 swings along the cam shape of the plate cam body 66. The crank lever 60 rotates counterclockwise about the support shaft 61 when viewed from the right side. The lateral lever 62 engages with the pin 58 and presses the draw bar 81 downward. The draw bar 81 urges the holder holding member 19 downward. The holder clamping member 19 releases the pull stud 17B. The tool holder 17 can be removed from the tapered hole 18 of the main shaft 9. As the spindle head 7 is further raised as shown in FIG. 9, the grip portion 91 of the grip arm 90 pulls out the tool holder 17 from the tapered hole 18 of the spindle 9. The spindle head 7 continues to rise.

  The CPU 31 determines whether or not the spindle head 7 has reached Z573 (S8). Until Z573 is reached (S8: NO), the process returns to S8 and the spindle head 7 continues to rise at the highest speed. When Z573 is reached (S8: YES), the CPU 31 starts decelerating to stop at Z615 (S9). The spindle head 7 begins to decelerate from the highest speed.

  The CPU 31 determines whether or not the spindle head 7 has reached Z615 (S10). Until it reaches Z615 (S10: NO), the CPU 31 returns to S10 and continues to raise the spindle head 7 at a low speed. When Z615 is reached (S10: YES), the CPU 31 stops the spindle head 7 (S11). As shown in FIGS. 5 and 10, the spindle head 7 rises while decelerating from the highest speed to zero in the section 104. A section 102 is a section from Z465 to Z490. The feed speed of the spindle head 7 becomes zero at Z615. The upward stroke of the spindle head 7 is completed.

[Tool magazine swivel]
The CPU 31 turns the tool magazine 21 (S12). The CPU 31 determines the grip arm 90 that holds the tool holder 17 that holds the next tool and moves it to the tool change position. The next tool is a tool specified by the tool change command. The tool change position is the lowest position of the tool magazine 21 and a position facing the spindle 9 in the vicinity.

[Descent process]
The CPU 31 starts to lower the spindle head 7 from Z615, which is the ATC origin, at the highest speed (S13). As shown in FIGS. 5 and 11, the spindle head 7 moves down the section 105 at the highest speed. A section 105 is a section from Z615 to Z535. As shown in FIG. 9, the plate cam body 66 slides downward with respect to the cam follower 67, but the crank lever 60 does not swing. As shown in FIG. 11, the feed speed of the spindle head 7 reaches the highest speed at Z573.

The CPU 31 determines whether or not the spindle head 7 has reached Z535 (S14). Until Z535 is reached (S14: NO), the process returns to S14 and the spindle head 7 continues to descend at the highest speed. When Z535 is reached (S14: YES), the CPU 31 starts decelerating (S15). The spindle head 7 begins to decelerate from the highest speed. When the descending speed of the spindle head 7 is reduced to a low speed, the CPU 31 maintains the descending speed of the spindle head 7 at a low speed (S16). In this embodiment, at least before the spindle head 7 reaches Z510, the descending speed of the spindle head 7 is reduced to a low speed. As shown in FIGS. 5 and 11, the spindle head 7 descends while being decelerated from the maximum speed to the low speed in the section 106. A section 106 is a section from Z535 to Z510.

  The CPU 31 determines whether or not the spindle head 7 has reached Z510 (S17). Until Z510 is reached (S17: NO), the process returns to S17 and the spindle head 7 continues to descend at a low speed. When Z510 is reached (S17: YES), as shown in FIG. 8, the tool holder 17 gripped by the gripping portion 91 of the grip arm 90 indexed to the tool change position is inserted into the tapered hole 18 of the spindle 9 and mounted. The hook of the tool holder 17 comes into contact with the tip of the main shaft 9. The spindle head 7 descends at a low speed. Therefore, the machine tool 1 can reduce the collision sound generated when the tool holder 17 is mounted on the tip end portion of the main shaft 9. Since the machine tool 1 can reduce the momentum when the tool holder 17 is attached to the tip of the main shaft 9, the load applied to the tip of the main shaft 9, the tool holder 17, and the grip arm 90 can be reduced.

  When Z510 is reached (S17: YES), since the tool holder 17 is already mounted on the tip of the spindle 9, the CPU 31 descends at the highest speed (S18). As shown in FIGS. 5 and 11, the spindle head 7 accelerates from a low speed in a section 107 and descends at a maximum speed. A section 107 is a section from Z510 to Z480 (Z-axis origin). The feed speed of the spindle head 7 reaches its maximum speed before reaching Z480.

  As shown in the order of FIGS. 8 to 6, when the spindle head 7 is lowered, the cam follower 93 slides the inclined surface of the cam body 11 fixed to the front surface of the spindle head 7 upward from below. The grip arm 90 swings around the pivot shaft 85. The grip portion 91 of the grip arm 90 moves from the close position to the retracted position.

  On the other hand, the plate cam body 66 slides downward with respect to the cam follower 67. The crank lever 60 swings along the cam shape of the plate cam body 66. The crank lever 60 rotates clockwise about the support shaft 61 when viewed from the right side. The lateral lever 62 is spaced upward from the pin 58 and releases the downward pressure on the draw bar 81. The draw bar 81 releases the downward bias to the holder holding member 19. The holder clamping member 19 clamps the pull stud 17B.

  The CPU 31 determines whether or not the spindle head 7 has reached Z480 (S19). Until Z480 is reached (S19: NO), the process returns to S19 and the spindle head 7 continues to descend at a high speed. When Z480 is reached (S19: YES), the spindle head 7 has reached the Z-axis origin, and moves to Z180, which is the machining position, while maintaining the highest speed (S20). The feed speed of the spindle head 7 decelerates before Z180 and becomes zero at Z180. The CPU 31 ends this process and executes the process of the next block of the NC program.

  In the above description, the tool 4 and the tool holder 17 that holds the tool 4 shown in FIG. 2 correspond to the tool of the present invention. Regarding the feed speed of the spindle head 7, the maximum speed corresponds to the first speed and the third speed of the present invention, and the low speed corresponds to the second speed of the present invention. The CPU 31 corresponds to the control means of the present invention. The CPU 31 that executes the processes of S4 and S5 in the upward stroke of the spindle head 7 and executes the processes of S15 and S16 in the downward stroke of the spindle head 7 corresponds to the first control means of the present invention. The CPU 31 that executes the process of S7 corresponds to the second control means of the present invention. The holder clamping member 19 corresponds to the tool holding mechanism of the present invention. The draw bar 81 corresponds to the unclamp member of the present invention. The crank lever 60 corresponds to the unclamping operation member of the present invention. The plate cam body 66 corresponds to the unclamp cam of the present invention. The cam follower 67 corresponds to the roller of the present invention.

  As described above, the numerical controller 30 according to the present embodiment controls the operation of the machine tool 1. The machine tool 1 includes a tool magazine 21 that can hold a plurality of tools. The machine tool 1 removes the tool holder 17 attached to the spindle 9 and transfers it to the tool magazine 21 when the spindle head 7 is raised from the Z-axis origin to the ATC origin. When the spindle head 7 is located at the ATC origin, the machine tool 1 turns the tool magazine 21 to position a desired tool holder so as to face the spindle 9. The machine tool 1 mounts a desired tool holder on the spindle 9 from the tool magazine 21 when the spindle head 7 is lowered from the ATC origin to the machine origin. In the ascending stroke and descending stroke of the tool change operation, the numerical control device 30 performs control to switch the spindle head 7 to the low speed after starting the movement at the maximum speed and to switch to the maximum speed. That is, in the ascending stroke and the descending stroke of the spindle head 7, the moving speed of the spindle head 7 temporarily decreases during the movement of the spindle head 7. Therefore, by switching from the maximum speed to the low speed in accordance with the timing at which the members come in contact with each other in the tool changing operation, it is possible to reduce the noise generated at the time of changing the tool and reduce the load on the machine tool 1. Furthermore, since the numerical control device 30 switches to the highest speed after the members contact each other, the time required for tool change can be shortened. Further, in the present embodiment, after switching from the first speed to the second speed, switching to the third speed, which is faster than the second speed, can reduce the time required for tool change.

  Further, in the present embodiment, after the spindle head 7 starts to rise at the highest speed in the ascending process of the tool change operation, the plate cam body 66 becomes low speed at the position where it abuts the cam follower 67. Therefore, the numerical control device 30 can reduce the collision noise that occurs when the cam follower 67 contacts the cam surface of the plate cam body 66 during the upward stroke of the spindle head 7. Further, the numerical control device 30 can reduce the load applied to the cam surface of the plate cam body 66 and the cam follower 67.

  Further, in the present embodiment, after the spindle head 7 starts to descend at the highest speed in the lowering process of the tool change operation, the tool holder 17 is lowered at the position where the tool holder 17 is attached to the spindle 9. Therefore, the numerical control device 30 can reduce a collision sound generated when the tool holder 17 is mounted on the spindle 9 during the descending stroke of the spindle head 7. Further, the numerical control device 30 can reduce the load applied to the spindle 9, the tool holder 17, and the grip arm 90.

  The present invention is not limited to the above embodiment, and various modifications can be made. In the above embodiment, as shown in FIGS. 10 and 11, two speed patterns are set in order to match the timing at which the spindle head 7 is switched from the maximum speed to the low speed in the ascending stroke and the descending stroke with the timing at which the members contact each other. To do. For example, as shown in FIG. 12, if the speed pattern is one speed pattern that slows the zone from Z490 to Z510, the numerical control device 30 can handle both the upward stroke and the downward stroke. Since there is only one speed pattern, the control can be simplified.

  In the above embodiment, the spindle head 7 starts to rise or descend at the highest speed, switches to a low speed, and then returns to the highest speed again. However, if the speed to switch after the low speed is higher than the low speed, the highest speed is achieved. It is not necessary to return to high speed.

  In the above embodiment, in the ascending stroke and the descending stroke, each of the sections moving at a low speed is one section, but a plurality of sections may be set in accordance with the timing at which the other members collide with each other.

  In the above-described embodiment, when the cam follower 67 contacts the cam surface of the plate cam body 66 in the ascending stroke, and in the descending stroke, the feeding speed of the spindle head 7 is set at a predetermined low speed in accordance with the mounting of the tool holder 17 to the spindle 9. However, the speed may be lowered before these timings.

  In the above embodiment, S5 and S16 in the process of FIG. 4 may be omitted.

DESCRIPTION OF SYMBOLS 1 Machine tool 2 Base 4 Tool 5 Column 7 Spindle head 8 Frame 9 Spindle 17 Tool holder 19 Holder clamping member 21 Tool magazine 26 Z-axis ball screw 30 Numerical control device 31 CPU
60 Crank lever 66 Plate cam body 67 Cam follower 81 Draw bar

Claims (1)

A column provided on the base; a spindle head provided on the column so as to be movable up and down; a spindle supported rotatably on the spindle head and mounted with a tool; a frame provided on the column and proximate to the spindle head; ATC origin is provided for controlling a machine tool provided with a tool magazine that is pivotably provided on the frame and is capable of holding a plurality of tools, wherein the spindle magazine is pivotable from the machine origin. The tool mounted on the spindle is removed and transferred to the tool magazine. When the spindle head is located at the ATC origin, the tool magazine is turned to face the desired tool against the spindle. When the spindle head is lowered from the ATC origin to the machine origin, the desired tool is moved from the tool magazine to the spindle. A numerical control device to be mounted,
A head support mechanism that is provided in the column and supports the spindle head so as to be movable up and down;
Control means for controlling the operation of the head support mechanism ;
A tool holding mechanism that is provided on the spindle head and holds the tool mounted on the spindle;
An unclamping operation member provided on the spindle head and releasing the tool mounted on the spindle by pressing an unclamping member of the tool holding mechanism;
An unclamp cam provided on the unclamp operation member;
The unclamp cam is brought into contact with and separated from the cam surface of the unclamp cam in an ascending stroke in which the spindle head is raised from the machining position to the ATC origin and a descending stroke in which the spindle head is lowered from the ATC origin to the machine origin. A roller for operating the clamp operating member ;
The control means includes
In each of the rising line as with the downward stroke,
A first control means for switching the spindle head moving speed to a second speed that is lower than the first speed after starting to move the spindle head at a first speed;
After the first control means switches the movement speed to the second speed, the second control means to switch the movement speed to a third speed that is faster than the second speed ,
The first control means includes
In the ascending stroke, at the position where the roller contacts the cam surface, switch to the second speed,
In the descending step, the numerical control device is switched to the second speed at a position where the tool is mounted on the spindle .

Images