JP2009237929A - Numerical controller, control program for numerical controller, and recording medium for numerical controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a numerical controller capable of automatically determining a coasting distance where a main spindle head is coasted extra when rapidly traversed toward a first movement end position and determining the coasting distance by a versatile control program, and to provide a control program and a recording medium for the numerical controller. <P>SOLUTION: When rapidly traversing the main spindle head by a Z-axis motor from each cutting operation completion position to a return position, rapid traverse is performed until reaching deceleration start timing based on a control command, a return operation is then performed up to the return position while a rapid traverse speed is maintained, and the Z-axis motor is subsequently decelerated up to a zero speed. After reaching the return position, at least either the Z-axis motor or a Y-axis motor is made to execute rapid traverse to calculate a coasting distance where the main spindle head coasts over the return position, and after the main spindle head is stopped by the deceleration operation, the Z-axis motor is operated in a direction reverse to a returning operation only by the coasting distance. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a numerical control device that controls a machine tool, a control program for a numerical control device, and a recording medium, and in particular, a direction orthogonal to a first axis that is partially overlapped with a fast-forward operation in the first axial direction. The present invention relates to a numerical control technology that enables fast-forwarding operation to be started as early as possible and shortens the cycle time of cutting.

  In a vertical numerically controlled machine tool, for example, when cutting a plurality of vertical holes parallel to the Z-axis, as shown in FIG. , X-axis and / or Y-axis rapid feed C, Z-axis descending rapid feed D, hole cutting feed E after the return to the Z-axis return position (position within the in-position width of the return position) Is normal. The speed waveform of the operation in each axis direction in this case is as shown in FIG.

By the way, Patent Document 1 proposes a technique that can shorten the cycle time by partially wrapping the Z-axis upward rapid feed B and the X-axis and / or Y-axis rapid feed C. In the technique of Patent Document 1, as shown in FIGS. 7A and 7B, the maximum speed of Z-axis fast-forwarding is increased to the return position by setting the coasting distance for fast-forwarding upward in the Z-axis. The arrival timing is advanced, the start timing of the X-axis and / or Y-axis fast-forward operation C is advanced, and the cycle time is shortened. In addition, since it rises excessively in the Z-axis direction by the coasting distance, the moving amount of the fast-forward D below the Z-axis is increased by a running distance equal to the coasting distance.
JP-A-9-120310

  Patent Document 1 does not describe in detail how to set the coasting distance, but provides an example in which a parameter corresponding to the maximum cutting feed rate is provided and calculation is performed according to the cutting feed rate. It is only described. However, if the set coasting distance is too large, the cycle time may be increased rather than shortened, and if the coasting distance is too small, the effect of shortening the cycle time becomes poor.

  In addition, when the parameters, constants, arithmetic expressions, etc. for determining the coasting distance are incorporated in each machining program, the machining program becomes complicated and the time required for creating the machining program becomes longer, making it versatile and practical. There is a problem of lack of sex. Therefore, it is desirable to be able to determine the coasting distance and the timing for starting X-axis and / Y-axis rapid feed by a versatile control program that can be commonly applied to various machining programs.

  The object of the present invention is to enable automatic determination of the coasting distance for coasting beyond the first movement end position when fast-forwarding toward the first movement end position, and to be applied commonly to various machining programs. It is to provide a numerical control device that makes it possible to determine the coasting distance by a possible versatile control program, a control program for the numerical control device, and a recording medium.

  The numerical control device according to claim 1 commands a plurality of feed motors of a machine tool based on a machining program having a positioning command including a movement end position of a tool or a workpiece and a command speed, and relatively moves the tool and the workpiece. In the numerical control apparatus for machining a workpiece, position information acquisition means for acquiring information related to the position of the tool or workpiece moved by the feed motor, and the machining program includes a first positioning including a first movement end position. When the command and the second positioning command including the second movement end position are continuously executed as commands, the tool or workpiece is not decelerated at the command speed based on the first positioning command by the first feed motor. When the position information acquisition means acquires that the first movement end position has been reached, a first control that decelerates the first feed motor. And when the position information acquisition means acquires that the tool or workpiece has moved to the first movement end position based on the first positioning command, the tool or workpiece is moved based on the second positioning command. A second control means for driving a second feed motor different from the first feed motor so as to start, and the first control motor decelerates the first feed motor by the first control means, so that the tool or workpiece ends the first movement. The position information acquisition unit acquires a stop position that has stopped beyond the position, and based on the stop position acquired by the position information acquisition unit and the first movement end position, the distance that the tool or workpiece has coasted A coasting distance calculating means for calculating and a tool so as to position the tool or workpiece to the first movement end position based on the distance calculated by the coasting distance calculating means. It is characterized in that a third control means for driving the first feed motor.

When the first positioning command and the second positioning command are continuously executed, information on the position of the tool or workpiece moved by the feed motor is acquired by the position information acquisition unit.
The first control means moves the tool or workpiece by the first feed motor according to the first positioning command, and moves the first feed motor to the first movement end position at the command speed without decelerating. Is switched to deceleration. The second control means starts the movement of the tool or workpiece by the second feed motor based on the second positioning command when the tool or workpiece moves to the first movement end position. The coasting distance calculating means calculates the distance the tool or workpiece has coasted based on the stop position at which the tool or workpiece has stopped beyond the first movement end position and the first movement end position by the first control means. Calculate. The third control means moves the tool or the workpiece to the first movement end position based on the distance calculated by the coasting distance calculation means.

According to a second aspect of the present invention, in the first aspect of the invention, the information on the position of the tool or workpiece is a feedback position of the first feed motor.
According to a third aspect of the present invention, in the first aspect of the invention, the information on the position of the tool or workpiece is a command position commanded by the first positioning command.

  According to a fourth aspect of the present invention, there is provided the numerical control device according to the first aspect, wherein the third control means stops the movement of the tool or workpiece to the first movement end position, and the second control means causes the tool or workpiece to move. When the movement stops at the second movement end position, a fourth control means for executing the next command of the machining program is provided.

  The numerical control device according to claim 5 is a numerical control device for driving and controlling the X-axis, Y-axis, and Z-axis driving means of a machine tool based on a machining program, wherein each cutting operation completion position is controlled by the Z-axis driving means. When fast-forwarding from the position to the return position, the Z-axis drive means is operated based on the control command until the deceleration start timing based on the control command is reached, and then the return is performed while maintaining the fast-forward speed of the Z-axis drive means. At least one of the X-axis driving means and the Y-axis driving means after the spindle head has reached the return position; Second control means for executing fast-forwarding based on a control command by one side and coasting distance calculating means for calculating a coasting distance in which the spindle head has coasted beyond the return position After the spindle head is stopped by the deceleration operation of the Z-axis driving means, the Z-axis driving means is operated in the opposite direction to the return operation by the coasting distance calculated by the coasting distance calculating means. And 3 control means.

  The return position in “until the return position is reached” means a position within the in-position width of the return position. “To reach the return position” may be when the feedback position reaches the return position, or when the command position commanded by the control command reaches the return position.

In FIG. 3 according to the embodiment, a Z-axis cutting feed a, a Z-axis rapid feed b, an X-axis and / or a Y-axis fast feed c, a Z-axis fast feed d and e, and a Z-axis cutting feed f are used. The velocity waveform in this case is as shown in FIG. The first control means is a deceleration start timing based on the control command (timing t1 in FIG. 4) when the spindle head is fast-forwarded by the Z-axis driving means from each cutting feed completion position to the return position by the Z-axis fast feed b. The Z-axis driving means is operated based on the control command until it reaches the position, and then the Z-axis driving means is returned until the return position is reached at the timing t2 in FIG. 4 while maintaining the rapid feed speed of the Z-axis driving means. Is decelerated to zero speed.
Note that the area of the hatched area of the parallelogram in the Z-axis rapid feed b in FIG. 4 corresponds to the “collision distance”.

  As described above, since the fast-forwarding is performed until the return position is reached while the Z-axis fast-forward speed is maintained at a high level between the timings t1 and t2, the timing t2 at which the return position is reached can be advanced, so that immediately after the timing t2. The second control means can start fast-forward c based on a control command from at least one of the X-axis drive means and the Y-axis drive means and complete fast-forward at an early stage. Therefore, it is possible to shorten the cycle time required to execute the series of operations a to f by advancing the completion timing of the fast-forward c.

  According to a sixth aspect of the present invention, there is provided a numerical control device control program comprising: a computer of a numerical control device that drives and controls the X-axis, Y-axis, and Z-axis drive means of a machine tool based on a machining program; When fast-forwarding from each cutting operation completion position toward the return position, the Z-axis drive means is operated based on the control command until the deceleration start timing based on the control command is reached, and then the rapid feed speed of the Z-axis drive means is set. The first control means for causing the Z-axis drive means to decelerate to zero speed, and then the X-axis drive means and the Y-axis after the spindle head has reached the return position. Second control means for executing fast-forwarding by at least one of the shaft driving means, and a coasting distance for calculating a coasting distance in which the spindle head has coasted beyond the return position After the spindle head is stopped by the calculating means and the deceleration operation of the Z-axis driving means, the Z-axis driving means is moved in the opposite direction to the return operation by the coasting distance calculated by the coasting distance calculating means. It is characterized by functioning as third control means to be operated.

  A recording medium for a numerical control device according to a seventh aspect is characterized in that the control program for the numerical control device according to a sixth aspect is recorded so as to be readable by a computer.

  According to the first aspect of the present invention, the position information acquisition means, the coasting distance calculation means, and the first to third control means are provided, and the first control means causes the first feed motor to perform the first positioning command. When the tool or workpiece is moved and moved to the first movement end position without decelerating, the first feed motor is switched to deceleration. When the tool or workpiece is moved to the first movement end position by the second control means, the movement of the tool or workpiece is started by the second feed motor based on the second positioning command. The coasting distance calculating means calculates the distance the tool or workpiece has coasted based on the stop position at which the tool or workpiece has stopped beyond the first movement end position and the first movement end position by the first control means. Calculate. The third control means moves the tool or the workpiece to the first movement end position based on the coasted distance calculated by the coasting distance calculating means.

  Thus, in order to operate the first feed motor without decelerating until the first movement end position is reached, the timing at which the first movement end position is reached is advanced by the second feed motor based on the second positioning command. The start timing for moving the tool or workpiece can be advanced, and the cycle time for executing a plurality of commands including the first and second positioning commands can be reliably shortened.

  Moreover, the first to third control means do not need to be incorporated into the machining program, and can be incorporated into a numerical control control program that decodes the machining program and creates a control command, and thus is excellent in versatility and practicality.

  According to the second aspect of the present invention, since the information on the position of the tool or workpiece is the feedback position of the first feed motor, the accuracy of the feed operation control by the second control means can be improved.

  According to the invention of claim 3, since the information regarding the position of the tool or workpiece is a command position commanded by the first positioning command, the coasting distance is always constant if the same operation is performed. The reproducibility of the feed operation control by one control means can be improved.

  According to the invention of claim 4, the tool or workpiece stops moving to the first movement end position by the third control means, and the tool or workpiece stops moving to the second movement end position by the second control means. In this case, since the fourth control means for executing the next command of the machining program is provided, the next command of the first and second positioning commands can be safely executed without interfering with the jig or the like.

  According to the fifth aspect of the present invention, as described above, the timing at which the spindle head reaches the return position can be advanced by the first control means, so the X-axis drive means and the Y-axis drive means by the second control means can be advanced. Since the fast feed start timing based on the control command by at least one can be advanced and the fast feed completion timing can be advanced, the cycle time can be reliably shortened.

  In addition, the first control means causes the Z-axis driving means to operate based on the control command until the deceleration start timing based on the control command, and then returns until the return position is reached while maintaining the rapid feed speed of the Z-axis driving means. Therefore, in order to fast-forward to the return position while maintaining the maximum speed obtained by acceleration of the Z-axis fast-forward, the coasting distance of an appropriate size proportional to the maximum speed is automatically determined and the coasting distance is determined. Can only be controlled to coast.

  Moreover, the first control means, the second control means, the coasting distance calculation means, and the third control means are incorporated into a numerical control control program that decodes the machining program instead of the machining program and creates a control command. Since it can be applied to machining programs in common, it has excellent versatility and practicality.

According to the invention of claim 6, the same effect as that of claim 5 can be obtained.
According to the invention of claim 7, the same effect as that of claim 5 can be obtained.

  Hereinafter, the best mode for carrying out the present invention will be described based on examples.

First, the configuration of the machining center 1 will be described.
As shown in FIG. 1, the machining center 1 performs desired machining (for example, “boring”, “milling”) on the workpiece by independently moving the workpiece and the tool relative to each axis in the XYZ rectangular coordinate system. ”,“ Drilling ”,“ cutting ”, etc.). The machining center 1 includes a cast iron base 2, a machine body 3 for cutting a workpiece, a box that is fixed to the upper part of the base 2 and covers the machine body 3 and the upper part of the base 2. It is comprised mainly by the shape-like splash cover (not shown).

  As shown in FIG. 1, the base 2 is a substantially rectangular parallelepiped casting that is long in the Y-axis direction. Legs 2a whose heights can be adjusted are respectively provided at the four corners of the lower part of the base 2, and the machining center 1 is installed by installing these legs 2a on the floor of a factory or the like.

  An operation panel 24 (see FIG. 2) for operating the machining center 1 is provided. The operation panel 24 is provided with a keyboard having a numeric keypad and various operation keys, and a display unit 25 (liquid crystal display) (see FIG. 2) for displaying a setting screen or an execution operation is provided above the operation panel 24. Yes. The operator operates the keyboard while confirming the display information on the display 25 of the operation panel 24, thereby performing a machining program for executing workpiece machining, the type of tool used, tool information, various parameters, etc. Can be set individually.

Next, the machine body 3 will be described.
As shown in FIG. 1, the machine body 3 includes a column 5 that is fixed to the upper surface of a column seat 4 on the rear portion of the base 2 and extends vertically upward, and a spindle head 7 that can be raised and lowered along the front surface of the column 5. A spindle 9 extending downward from the lower part of the spindle head 7, and a tool changer (ATC) provided on the right side of the spindle head 7 for attaching and replacing a tool holder (not shown) with a tool at the tip of the spindle 9 20 and a table 10 which is provided on the upper part of the base 2 and detachably fixes the workpiece. A box-shaped control box 6 is provided on the back side of the column 5, and a numerical control device 30 (see FIG. 2) for controlling the operation of the machining center 1 is provided inside the control box 6.

Next, the moving mechanism of the table 10 will be described.
As shown in FIGS. 1 and 2, the table 10 is driven by an X-axis motor 51 and a Y-axis motor 52, which are servo motors, in the X-axis direction (the left-right direction of the machine body 3) and the Y-axis direction (the depth of the machine body 3). Direction). This moving mechanism has the following configuration. First, a rectangular parallelepiped support base 12 is provided below the table 10. A pair of X-axis feed guides extending along the X-axis direction are provided on the upper surface of the support base 12, and the table 10 is movably supported on the pair of X-axis feed guides.

  The support base 12 is provided on the upper portion of the base 2 and is movably supported on a pair of Y-axis feed guides extending along the longitudinal direction of the base 2. Thus, the table 10 is driven to move in the X-axis direction along the X-axis feed guide by the X-axis motor 51 provided on the base 2, and is converted into a Y-axis feed guide by the Y-axis motor 52 provided on the base 2. And driven to move in the Y-axis direction.

  The X-axis feed guide is provided with telescopic covers 13 and 14 that contract in a telescopic manner on both left and right sides of the table 10. In the Y-axis feed guide, a telescopic cover 15 and a Y-axis rear cover are provided before and after the support base 12, respectively. With these plural covers, the X-axis feed guide and the Y-axis feed guide always serve as the telescopic covers 13, 14, 15 and the Y-axis rear cover even when the table 10 moves in either the X-axis direction or the Y-axis direction. Covered by. Therefore, it is possible to prevent the chips scattered from the processing region, the splash of coolant liquid, and the like from falling on each rail.

Next, the raising / lowering mechanism of the spindle head 7 will be described.
As shown in FIG. 1, the spindle head 7 is supported by a guide rail extending in the vertical direction on the front side of the column 5 so as to be movable up and down via a linear guide. The spindle head 7 is connected to a feed screw extending in the vertical direction on the front side of the column 5 by a nut. The spindle head 7 is driven up and down in the vertical direction by rotationally driving the feed screw in the forward and reverse directions by a Z-axis motor 53 (see FIG. 2).

Next, the main shaft 9 will be described.
As shown in FIG. 1, the main shaft 9 is formed in a cylindrical shape that is long in the vertical direction, and a spindle is rotatably provided inside thereof. The spindle is rotationally driven by a spindle motor 54 provided on the upper part of the spindle head 7. A holder mounting hole (not shown) that increases in diameter toward the tip is provided in the tip side portion of the spindle.

  As shown in FIG. 1, the tool changer 20 grips and conveys a tool magazine 21 that stores a plurality of tool holders that support tools, a tool holder that is attached to the spindle 9, and other tool holders. It consists of a tool change arm 22 and the like. Inside the tool magazine 21, a plurality of tool pots that support the tool holder and a transport mechanism that transports the tool pots within the tool magazine 21 are provided.

Next, a control system of the machine tool 1 will be described.
As shown in FIG. 2, the numerical controller 30 includes a microcomputer, and includes a CPU 31, a ROM 32, a RAM 33, an input / output interface 34, axis control circuits 41 a to 45 a, and servo amplifiers 41 to 41. 44, differentiators 51b to 54b, and the like. The servo amplifiers 41 to 44 are connected to an X-axis motor 51, a Y-axis motor 52, a Z-axis motor 53, and a main shaft motor 54, respectively. The axis control circuit 45 a is connected to the magazine motor 55. The RAM 33 stores various machining programs input and registered by the user, and the ROM 32 stores in advance a numerical control program for decoding the machining program.

  The X-axis motor 51 and the Y-axis motor 52 are for moving the table 10 in the X-axis direction and the Y-axis direction. The magazine motor 55 is for rotating the tool magazine 21. The main shaft motor 54 is for rotating the main shaft 9. The X-axis motor 51, the Y-axis motor 52, the Z-axis motor 53, and the main shaft motor 54 include encoders 51a to 54a, respectively.

  The axis control circuits 51 a to 54 a receive a movement command amount from the CPU 31 and output a current command amount (torque command value) to the servo amplifiers 41 to 44. The servo amplifiers 41 to 44 receive this command and output a drive current to the motors 51 to 54. The axis control circuits 41a to 44a receive position feedback signals from the encoders 51a to 54a and perform position feedback control. The differentiators 51b to 54b differentiate the position feedback signals input from the encoders 51a to 54a to convert them into speed feedback signals, and output the speed feedback signals to the axis control circuits 41a to 44a.

  The axis control circuits 41a to 44a receive speed feedback signals from the differentiators 51b to 54b and control the speed feedback. The drive currents output from the servo amplifiers 41 to 44 to the motors 51 to 54 are detected by current detectors 41b to 44b. The drive currents detected by the current detectors 41b to 44b are fed back to the axis control circuits 41a to 44a. The axis control circuits 41a to 44a perform current (torque) control by the fed back drive current.

  In general, the drive current flowing through the motors 51 to 54 and the load torque applied to the motors 51 to 54 are approximately the same, so that the current detectors 41b to 44b that detect the drive current flowing through the motors 51 to 54 are used. Can be detected. The axis control circuit 45a drives the magazine motor 55 in response to a movement command amount from the CPU 31. The numerical control device 30 is connected to an operation panel 24 having operation keys and the like, and a display 25. The X-axis motor 51 corresponds to the X-axis drive means, the Y-axis motor 52 corresponds to the Y-axis drive means, and the Z-axis motor 53 corresponds to the Z-axis drive means.

Next, the multi-axis rapid feed control unique to the present application applied to a machining program for forming a plurality of vertical holes parallel to the Z-axis in the workpiece by the machine tool 1 will be described.
First, the outline of the multi-axis rapid feed control will be described with reference to FIGS.
The numerical control device 30 includes the following first, second and third control means and coasting distance calculation means.

  As shown in FIG. 3 and FIG. 4, the first control means uses a control command when the spindle head 7 performs Z-axis rapid feed b from the completion position of the cutting feed a toward the return position by the Z-axis motor 53. Based on the control command, the Z-axis motor 53 is operated until the deceleration start timing t1 is reached, and then the Z-axis motor 53 is returned to the return position while maintaining the rapid feed speed of the Z-axis motor 53, and then the Z-axis motor 53 is set to zero speed. To slow down.

The second control means causes fast-forward c based on a control command from at least one of the X-axis motor 51 and the Y-axis motor 52 after the spindle head 7 reaches the return position.
The coasting distance calculation means calculates the coasting distance (the area of the hatched area of the parallelogram in the fast-forward operation b in FIG. 3) that the spindle head 7 has coasted beyond the return position.

  After the spindle head 7 is stopped by the deceleration operation of the Z-axis motor 53, the third control unit reverses the Z-axis motor 53 to the return operation by the coasting distance calculated by the coasting distance calculation unit. A fast-forward operation in the direction is performed (see fast-forward d in FIG. 4). Note that the rapid feed e is a rapid feed based on a control command executed after the rapid feed c and the fast feed d are finished, and the cutting feed f is an operation of cutting the next vertical hole.

  Next, a control program for multi-axis fast-forward control as the first, second and third control means and coasting distance calculation means will be described based on the flowchart of FIG. This control program is stored in advance in the ROM 32, and the RAM 33 is provided with various work memories necessary for executing the multi-axis rapid feed control. In the flowchart, the symbol Si (i = 1, 2,...) Indicates each step.

  This multi-axis rapid feed control is applied to a machining program that cuts a plurality of standing holes in a workpiece at predetermined intervals. The machining program describes operations in the order of operations as control commands in a predetermined program language. FIG. 5 shows a machining program in which operations such as Z-axis cutting feed A, Z-axis ascending rapid feed B, X-axis and / or Y-axis rapid feed C, and Z-axis descending rapid feed D as shown in FIG. It demonstrates based on the flowchart of these. Note that the Z-axis ascending rapid feed B corresponds to the first positioning command, the X-axis and / or Y-axis rapid feed C corresponds to the second positioning command, and the return position P corresponds to the first movement end position. The second movement end position is Q. The Z-axis motor 53 corresponds to a first feed motor, and the X-axis motor 51 and / or the Y-axis motor 52 corresponds to a second feed motor. Further, in the machining program, the operation is the same as the operation in FIG. 6A, but according to the flowchart in FIG. 5, the operation shown in FIG. 3 is performed. The command speed of the cutting feed command can be set by a control command, and the speed of the fast feed command for each axis is stored in advance in the RAM 33 or the like by a parameter.

  As shown in FIG. 5, when the machining program is started, the counter n is first set to “1”, although not shown. The current (n) control command, the next (n + 1) control command, and the next (n + 2) control command are read and interpreted (S1). Next, it is determined whether or not the current (n) control command is a program end (S2). When the determination is Yes, the machining program ends, and when the determination of S2 is No, the process proceeds to S3.

  In S3, it is determined whether or not the next (n + 1) control command is X-axis and / or Y-axis fast-forward and the next (n + 2) control command is Z-axis descending fast-forward. The process proceeds to S4, and after executing the current (n) control command, the process proceeds to S17. In S17, the control command n is incremented by “1”, and then the process returns to S1. When the determination of S3 is Yes, it is determined whether or not the current (n) control command is Z-axis ascending rapid feed (S5). When the determination is No, the process proceeds to S4, and after the execution of the current (n) control command, the process proceeds to S17. Transition. When the determination in S5 is Yes, Z-axis ascending rapid feed of the current (n) control command is started (S6). In S7, it is determined whether or not the Z axis ascending rapid feed deceleration start timing based on the control command (timing t1 in FIG. 4). When the determination is No, the current (n) control command is continued in S8 and the process returns to S7. When the determination in S7 is Yes, the process proceeds to S9.

  In S9, the Z-axis rising / fast-forwarding operation is continued while maintaining the Z-axis rising / fast-forwarding speed. Next, in S10, it is determined whether or not the Z-axis feedback position is within the in-position range from the return position. When the determination in S10 is No, the process returns to S9 and S9 and S10 are executed. For example, when the determination in S10 is Yes at timing t2 in FIG. 4, the process proceeds to S11. In S11, the next (n + 1) control command X-axis and / or Y-axis rapid feed C (c in FIG. 3) is started, and the Z-axis deceleration is started.

  In the next S12, it is determined whether or not the Z-axis deceleration is finished, that is, whether or not the Z-axis speed has become zero. If the determination is No, S12 is repeated, and if the determination in S12 is Yes, the process proceeds to S13. . Next, in S13, the Z-axis coasting distance exceeding the return position is calculated. The coasting distance is calculated as "stop position-return position"

  Next, in S14, as shown in FIG. 4, the Z-axis descending rapid feed d is executed for the Z-axis coasting distance. In the next S15, it is determined whether or not the rapid traverse C (c in FIG. 3) of the X-axis and / or the Y-axis is completed, and whether the Z-axis descending rapid traverse d is completed. When the determination of S15 is No, S15 is repeated, and when the determination of S15 is Yes, the process proceeds to S16. In S16, the control command n is incremented by “2”, and then the process returns to S1.

In the flowchart of FIG. 5, the numerical control device 30 that executes S7 to S12 corresponds to “first control means”, the numerical control device 30 that executes S11 corresponds to “second control means”, and executes S14. The numerical control device 30 that performs the processing corresponds to “third control means”, and the numerical control device 30 that executes S13 corresponds to “running distance calculation means”. The numerical controller 30 that executes S15 and S16 corresponds to a “fourth control unit”. In the example of the multi-axis rapid feed control shown in FIG. 3, “execute the next command” is to execute the Z-axis descending rapid feed e.
The flowchart of FIG. 5 corresponds to the “control program for numerical control device” of the present application, and the flowchart of FIG. 5 is described in a predetermined program language and recorded on a recording medium so as to be readable by a computer. It corresponds to “recording medium for apparatus”.
The position information acquisition means includes the encoders 51a to 54a, the axis control circuits 41a to 44a, the CPU 31, the ROM 32, and the like. The “information regarding the position of the tool or workpiece” may be a feedback position of the X-axis, Y-axis, or Z-axis feed motors 51 to 53, or a command position commanded by the “positioning command”. It may be.

Next, the operation and effect of this multi-axis rapid feed control will be described.
When the deceleration start timing t1 commanded by the control command is reached, the spindle head 7 returns to maintain the Z-axis fast-forward speed and increase it until it reaches the return position without reducing the Z-axis fast-forward speed. Since the timing to reach the position can be advanced, the rapid feed start timing t2 based on the control command by at least one of the X-axis motor 51 and the Y-axis motor 52 can be advanced, and the completion timing of the rapid feed c can be advanced. Time can be shortened reliably.

  In addition, the Z-axis motor 53 is operated based on the control command until the deceleration start timing t1 based on the control command, and then the Z-axis motor 53 is returned until the return position is reached while maintaining the rapid feed speed of the Z-axis motor 53. Since the fast-forwarding is made to the return position while maintaining the speed obtained by the acceleration of the fast-forwarding, it is possible to control the vehicle to coast by an appropriately determined coasting distance.

  In addition, since the flowchart of FIG. 5 is incorporated in a numerical control program instead of a machining program and can be commonly applied to various machining programs, it is excellent in versatility and practicality. When performing the return operation while maintaining the fast-forward speed by the Z-axis motor 53, the return operation is performed until the feedback position reaches the return position, so that the accuracy of the fast-forward c of the X axis and / or the Y axis can be improved.

  However, the machine tool is not limited to that of the first embodiment, and may be a machine tool of a type in which a column on which a spindle is mounted moves. The first feed motor is not limited to the Z-axis motor 53 but may be an X-axis motor 51 or a Y-axis motor 52.

Next, an example in which the above embodiment is partially changed will be described.
1] In S10 of the flowchart of FIG. 5, it is determined whether or not the Z-axis feedback position is within the in-position range from the return position. Instead of the “Z-axis feedback position”, the “command position” is commanded by a control command. It may be determined whether or not is within the in-position range from the return position. In this case, since the return operation is performed until the command position commanded by the control command reaches the return position when the return operation is performed while maintaining the rapid traverse speed of the Z-axis ascending / descending b, the coasting distance is always the same for the same operation. Since it becomes constant, the reproducibility of the Z-axis fast-forward operation can be improved.

  2] In FIG. 4, in the Z-axis ascending rapid feed b, the deceleration start timing t1 is reached during acceleration. However, when the distance to the return position in the Z-axis direction is large, the Z-axis ascending rapid feed based on the control command is performed. Since the operation is performed in the order of acceleration, constant speed, and deceleration at b, in this case, the timing for shifting from constant speed to deceleration is t1.

1 is an overall perspective view of a numerically controlled machine tool according to an embodiment of the present invention. It is a block diagram of the control system of the machine tool. It is explanatory drawing of the cutting operation | movement at the time of cutting a hole parallel to a Z-axis, and fast-forwarding operation | movement. FIG. 4 is a velocity waveform diagram in the case of FIG. 3. It is a flowchart of multi-axis rapid feed control unique to the present application. (A) FIG. 3 equivalent figure based on a prior art, (b) is a velocity waveform figure in the case of (a). (A) FIG. 3 equivalent figure which concerns on the prior art of patent document 1, (b) is a velocity waveform figure in the case of (a).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Machine tool 7 Spindle head 30 Numerical control apparatus 51 X-axis motor 52 Y-axis motor 53 Z-axis motor

Claims (7)

A numerical control device that commands a plurality of feed motors of a machine tool based on a machining program having a positioning command including a movement end position of a tool or a workpiece and a command speed, and moves the tool and the workpiece relatively to machine the workpiece. In
Position information acquisition means for acquiring information on the position of the tool or workpiece moved by the feed motor;
When the machining program has a first positioning command including a first movement end position and a second positioning command including a second movement end position as a command to continuously execute the tool or workpiece by a first feed motor. A first control means for decelerating the first feed motor when the position information obtaining means obtains that the movement to the first movement end position without decelerating at a command speed based on the first positioning command;
When the position information acquisition means acquires that the tool or workpiece has moved to the first movement end position based on the first positioning command, the movement of the tool or workpiece starts based on the second positioning command. Second control means for driving a second feed motor different from the first feed motor;
The position information acquisition means acquires the stop position where the first control motor decelerates the first feed motor to stop the tool or workpiece beyond the first movement end position, and the position information acquisition means acquires the stop position. A coasting distance calculating means for calculating a distance that the tool or workpiece has coasted based on the stopped position and the first movement end position;
And third control means for driving the first feed motor to position the tool or workpiece to the first movement end position based on the distance calculated by the coasting distance calculation means. Numerical control device.   The numerical control device according to claim 1, wherein the information related to the position of the tool or the workpiece is a feedback position of the first feed motor.   The numerical control device according to claim 1, wherein the information on the position of the tool or the workpiece is a command position commanded by the first positioning command.   When the third control means stops the movement of the tool or workpiece to the first movement end position and the second control means stops moving the tool or workpiece to the second movement end position, The numerical control device according to claim 1, further comprising fourth control means for executing a command. In a numerical control device that drives and controls the X-axis, Y-axis, and Z-axis drive means of a machine tool based on a machining program,
When the spindle head is fast-forwarded from the cutting operation completion position toward the return position by the Z-axis driving means, the Z-axis driving means is operated based on the control command until the deceleration start timing based on the control command is reached, and thereafter First control means for causing the Z-axis drive means to return until the return position is reached while maintaining the fast-forward speed of the Z-axis drive means, and then decelerating the Z-axis drive means to zero speed;
Second control means for executing fast-forwarding based on a control command by at least one of the X-axis drive means and the Y-axis drive means after the spindle head reaches the return position;
Coasting distance calculating means for calculating the coasting distance that the spindle head has coasted beyond the return position;
After the spindle head is stopped by the deceleration operation of the Z-axis driving means, the Z-axis driving means is operated in the direction opposite to the return operation by the coasting distance calculated by the coasting distance calculating means. Control means;
A numerical control device comprising: A computer of a numerical control device that drives and controls the X-axis, Y-axis, and Z-axis drive means of a machine tool based on a machining program,
When the spindle head is fast-forwarded from the cutting operation completion position toward the return position by the Z-axis driving means, the Z-axis driving means is operated based on the control command until the deceleration start timing based on the control command is reached, and thereafter First control means for causing the Z-axis drive means to return until the return position is reached while maintaining the fast-forward speed of the Z-axis drive means, and then decelerating the Z-axis drive means to zero speed;
Second control means for executing fast-forwarding by at least one of the X-axis driving means and the Y-axis driving means after the spindle head reaches the return position;
Coasting distance calculating means for calculating the coasting distance that the spindle head has coasted beyond the return position;
After the spindle head is stopped by the deceleration operation of the Z-axis driving means, the Z-axis driving means is operated in the direction opposite to the return operation by the coasting distance calculated by the coasting distance calculating means. Control means;
A control program for a numerical control device characterized in that it functions as a control program.   A recording medium for a numerical control device, wherein the control program for the numerical control device according to claim 6 is recorded so as to be readable by a computer.

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