This application is a National Stage of International Application No. PCT/JP2012/069881 filed Aug. 3, 2012, the contents of all of which are incorporated herein by reference in their entirety.
The present invention relates to a numerical control apparatus.
When a machining process for repeating acceleration and deceleration of a spindle motor in one cycle is repeatedly executed by a machine tool a plurality of times, in some case, the temperature of the spindle motor rises and finally the spindle motor overheats and urgently stops.
To deal with this problem, Patent Literature 1 discloses a technology for predicting a motor temperature from a motor temperature measured by a temperature sensor. According to the technology of Patent Literature 1, as measures against a likelihood that the predicted motor temperature is equal to or higher than a threshold to cause overheating, a method of reducing maximum speed of a motor, a method of increasing an acceleration/deceleration time constant of the motor and reducing the value of a motor current during acceleration and deceleration, and a method of increasing an operation stop time when a machine driven by the motor repeatedly performs the same operation pattern, and the like.
According to the technology of Patent Literature 1, the prediction of the motor temperature is performed on the basis of a relation between a motor average current obtained by measurement in advance and a motor temperature rise amount or the prediction of the motor temperature is performed using a function calculated in advance from an experiment data or the like for calculating a predicted motor temperature from a measured motor temperature difference in a predetermined cycle period. Changes of the motor acceleration/deceleration time constant, the motor maximum speed, and the operation stop time are adjusted to values set in advance.
Patent Literature 1: Japanese Patent Application Laid-Open No. H10-80055
However, according to the technology described in Patent Literature 1, there is a problem in that a large-capacity memory that stores the relation between the motor average current and the motor temperature rise amount to predict the motor temperature is necessary. When the prediction of the motor temperature is performed using the function for calculating the predicted motor temperature from the measured motor temperature difference in the predetermined cycle period, there is a problem in that the experiment needs to be performed every time the type of the motor is changed. The adjustment of the motor acceleration/deceleration time constant, the motor maximum speed, and the operation stop time is performed using setting values (fixed values) set in advance. Therefore, there is a problem in that an adjustment effect is different depending on the setting values.
The present invention has been devised in view of the above and it is an object of the present invention to obtain a numerical control apparatus that can avoid overheating of a spindle motor as easy as possible.
In order to solve the aforementioned problems, a numerical control apparatus according to one aspect of the present invention is constructed in such a manner as to include: a cycle-time measuring unit that measures a cycle time in machining a workpiece; a current-amount measuring unit that measures a current amount per unit cycle flowing to a motor that drives a workpiece rotating shaft; a cycle-time calculating unit that calculates, on the basis of the measured current amount per unit cycle, a cycle time at which suppression of occurrence of overheating of the motor is guaranteed; a processing unit that determines on the basis of a comparison of a cycle time calculation value by the cycle-time calculating unit and a cycle time measurement value by the cycle-time measuring unit whether the motor overheats; and a delay unit that delays, when the processing unit determines that the motor overheats, a start of a next cycle by at least a value obtained by subtracting the cycle time measurement value from the cycle time calculation value.
The numerical control apparatus according to the present invention suppresses occurrence of overheating of a spindle motor without a prior experiment or an input of detailed current/temperature characteristics for each motor. Therefore, it is possible to avoid the overheating of the spindle motor as easy as possible.
Embodiments of a numerical control apparatus according to the present invention are explained in detail below with reference to the drawings. Note that the present invention is not limited by the embodiments.
First Embodiment.
For example, a signal for an automatic start is supplied to the control operation unit 30 according to operation of an automatic start button (not shown in the figure) by a user. Upon receiving the signal for the automatic start, the control operation unit 30 starts a machining program 343. The control operation unit 30 generates, according to the machining program 343, a moving amount command for an X axis, a moving amount command for a Z axis, and a rotation command for a spindle (a workpiece rotating shaft) and supplies the generated commands to the driving unit 90. The driving unit 90 includes an X-axis-servo control unit 91, a Z-axis-servo control unit 92, and a spindle-servo control unit 94 and drives an X-axis servo motor 901 and a Z-axis servo motor 902 according to the moving amount command for the X axis and the moving amount command for the Z axis input from the control operation unit 30. The driving unit 90 controls to rotate a spindle motor 904 according to a number-of-revolutions command for the spindle input from the control operation unit 30. The X-axis-servo control unit 91 receives feedback position data from an X-axis position sensor 95 of the X-axis servo motor 901 and performs position feedback control. Similarly, the Z-axis servo control unit 92 receives feedback position data from a Z-axis position sensor 96 of the Z-axis servo motor 902 and performs position feedback control. The spindle-servo control unit 94 receives feedback speed data or feedback position data from a spindle sensor 97 of the spindle motor 904 and performs speed feedback control or position feedback control.
The control operation unit 30 further includes a PLC (Programmable Logic Controller) 36, a machine-control-signal processing unit 35, a storing unit 34, an analysis processing unit 37, an interpolation processing unit 38, an acceleration/deceleration processing unit 43, an axis-data input/output unit 42, a screen processing unit 31, an input control unit 32, a data setting unit 33, and a duty-cycle-calculation processing unit (a cycle-time calculating unit, a processing unit) 41.
The storing unit 34 includes a region for storing parameters 341, a machining program 343, and screen display data 344. The storing unit 34 also includes a shared area 345 serving as a work space. The input operation unit 20 is configured by an input device such as a hardware switch or a touch panel. The parameters 341 and the machining program 343 are input to the data setting unit 33 through the input control unit 32 when an operator operates the input operation unit 20. The data setting unit 33 converts the input parameters 341 and the input machining program 343 into data and stores the data in the storing unit 34. The screen display data 344 stored in the storing unit 34 is read by the screen processing unit 31 and sent to the display unit 10. The display unit 10 includes a display device such as a liquid crystal panel and displays the sent screen display data 344 to enable the operator to visually recognize the screen display data 344.
The signal for the automatic start is input to the machine-control-signal processing unit 35 through the PLC 36. The machine-control-signal processing unit 35 receives the signal for the automatic start and instructs, via the storing unit 34 (for example, the shared area 345 of the storing unit 34), the analysis processing unit 37 to start execution of the machining program 343. The analysis processing unit 37 instructed to start the execution of the machining program 343 starts reading of the machining program 343.
The analysis processing unit 37 reads out the machining program 343 from the storing unit 34 according to the start instruction, performs analysis processing concerning blocks (rows) of the machining program 343, and passes a position command serving as an analysis result to the interpolation processing unit 38 via the shared area 345.
The interpolation processing unit 38 receives the analysis result (the position command) from the analysis processing unit 37, performs interpolation processing for the analysis result (the position command), and supplies a result of the interpolation processing (a moving amount and a rotating amount) to the acceleration/deceleration processing unit 43. The interpolation processing unit 38 receives a rotation command and a number-of-revolutions command for the spindle motor 904 from the analysis processing unit 37 via the shared area 345 and passes the rotation command and the number-of-revolutions command to the acceleration/deceleration processing unit 43.
The acceleration/deceleration processing unit 43 applies acceleration/deceleration processing to the result of the interpolation processing supplied from the interpolation processing unit 38. The acceleration/deceleration processing unit 43 outputs acceleration/deceleration processing results concerning the X axis and the Z axis to the duty-cycle-calculation processing unit 41. The acceleration/deceleration processing unit 43 performs the acceleration/deceleration processing for the spindle motor 904 and outputs an acceleration/deceleration processing result to the spindle-servo control unit 94 through the duty-cycle-calculation processing unit 41 and the axis-data input/output unit 42.
The duty-cycle-calculation processing unit 41 outputs the received acceleration/deceleration processing result to the X-axis-servo control unit 91 and the Z-axis-servo control unit 92 through the axis-data input/output unit 42.
The X-axis-servo control unit 91 receives the feedback position data from the X-axis position sensor 95 of the X-axis servo motor 901 and performs position feedback control. Similarly, the Z-axis servo control unit 92 receives the feedback position data from the Z-axis position sensor 96 of the Z-axis servo motor 902 and performs the position feedback control. The spindle-servo control unit 94 receives the speed feedback data or the position feedback data from the spindle sensor 97 of the spindle motor 904 and performs the speed feedback control or the position feedback control.
The spindle-servo control unit 94 detects an electric current of the spindle motor 904 and outputs the electric current to the duty-cycle-calculation processing unit 41 through the axis-data input/output unit 42. The duty-cycle-calculation processing unit 41 calculates, on the basis of the electric current of the spindle motor 904 received from the axis-data input/output unit 42, a minimum machining time in which suppression of the occurrence of overheating of the spindle motor 904 is guaranteed (hereinafter referred to as duty cycle time). The duty-cycle-calculation processing unit 41 compares a cycle time measured by a cycle-time measuring unit 382 explained below and the duty cycle time to determine whether the spindle motor 904 overheats.
The interpolation processing unit 38 includes a delay unit 381 and a cycle-time measuring unit 382.
The cycle-time measuring unit 382 is cyclically called by internal processing of the interpolation processing unit 38. The cycle-time measuring unit 382 measures a cycle time (time for one cycle) of the machining program 343 on the basis of the number of calling and a cycle (a calling interval) of the calling.
The delay unit 381 calculates a difference between the duty cycle time calculated by the duty-cycle-calculation processing unit 41 and the cycle time of the machining program 343 measured by the cycle-time measuring unit 382. When the measured cycle time of the machining program 343 is smaller than the duty cycle time calculated by the duty-cycle-calculating processing unit 41, the delay unit 381 delays a start of the next machining cycle by time of the difference.
Note that the control operation unit 30 is typically realized by a computer including a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and an I/O interface. Specifically, for example, the CPU executes a numerical control program stored in the ROM in advance to thereby function as the PLC 36, the machine-control-signal processing unit 35, the analysis processing unit 37, the interpolation processing unit 38, the acceleration/deceleration processing unit 43, the screen processing unit 31, the data setting unit 33, and the duty-cycle-calculation processing unit 41. The storing unit 34 is configured by the ROM or the RAM or both of the ROM and the RAM. Functions of the input control unit 32 and the axis-data input/output unit 42 are realized by the I/O interface. Note that the control operation unit 30 may be configured to realize a part or all of functional units, which are enumerated as being typically realized on the CPU, with hardware or a combination of the hardware and software (a numerical control program).
When the operator performs operation for a start, the analysis processing unit 37 counts up (+1) a number-of-machined-pieces counter for measuring the number of machined works (workpieces) (the number of machined pieces) in the shared area 345 (step S1). Note that, in an initial state, a zero value is stored as a value of the number-of-machined-pieces counter. “1” is set by the first processing at step S1. The number-of-machined-pieces counter is set in, for example, the shared area 345.
Subsequently, the control operation unit 30 executes machining of the work (step S2). Details of processing at step S2 are specifically as explained below.
In the processing at step S2, first, the analysis processing unit 37 performs an analysis of the machining program 343 and passes an analysis result (a position command) of the machining program 343 to the interpolation processing unit 38. The interpolation processing unit 38 receives the analysis result (the position command) from the analysis processing unit 37, performs interpolation processing for the analysis result (the position command), and supplies a result of the interpolation processing to the acceleration/deceleration processing unit 43. The acceleration/deceleration processing unit 43 applies acceleration/deceleration processing to the supplied result of the interpolation processing and supplies an acceleration/deceleration processing result to the axis-data input/output unit 42 through the duty-cycle-calculation processing unit 41. Subsequently, the axis-data input/output unit 42 performs axis data output processing. That is, the axis-data input/output unit 42 supplies, a moving amount command ΔX for the X axis, a moving amount command ΔZ for the Z axis, or a number-of-revolutions command or a position command for the spindle, which is supplied from the duty-cycle-calculation processing unit 41, to the driving unit 90. The driving unit 90 drives the X-axis servo motor 901 and the Z-axis servo motor 902 according to the input moving amount command ΔX for the X axis and the input moving amount command Δz for the Z axis. The driving unit 90 subjects the spindle motor 904 to rotation control or position control according to the number-of-revolutions command or the position command for the spindle input from the axis-data input/output unit 42. The X-axis-servo control unit 91 receives feedback position data from the X-axis position sensor 95 of the X-axis servo motor 901 and performs position feedback control. Similarly, the Z-axis servo control unit 92 receives position feedback data from the Z-axis position sensor 96 of the Z-axis servo motor 902 and performs position feedback control. The spindle-servo control unit 94 receives speed feedback data or position feedback data from the spindle sensor 97 of the spindle motor 904 and performs speed feedback control or position feedback control.
During the execution of the processing at step S2, the duty-cycle-calculation processing unit 41 performs measurement of a current value flowing to the spindle motor 904 during machining (step S3). Specifically, the spindle-servo control unit 94 detects a feedback current from the spindle motor 904 and outputs the detected feedback current to the duty-cycle-calculation processing unit 41 through the axis-data input/output unit 42. The duty-cycle-calculation processing unit 41 classifies the received feedback current of the spindle motor 904 into a current value and time during acceleration, a current value and time during deceleration, and a current value and time during steady rotation and stores the feedback current in the shared area 345 of the storing unit 34.
During the execution of the processing at step S2, the analysis processing unit 37 determines whether machining for one cycle has ended (step S4). When the machining for one cycle has not ended (No at step S4), the analysis processing unit 37 executes the determination processing at step S3 again. When the machining for one cycle has ended (Yes at step S4), the processing is advanced to step S5.
In processing at step S5, the cycle-time measuring unit 382 measures a cycle time (time for one cycle) of the machining program 343 (step S5). The cycle-time measuring unit 382 measures the cycle time of the machining program 343 on the basis of the number of calling and a cycle (a call cycle) of calling of processing of the cycle-time measuring unit 382.
The duty-cycle-calculation processing unit 41 substitutes the current value during the acceleration, the time during the acceleration, the current value during the steady rotation, the time during the steady rotation, the current value during the deceleration, and the time during the deceleration recorded in the shared area 345 in Formula 1 below and calculates a duty cycle time (step S6).
Duty cycle time=((spindle acceleration time current^2×acceleration time)+(spindle deceleration time current^2×deceleration time)+(spindle steady time current^2×steady rotation time))/((continuous rated output/short time rated output)^2) (1)
Note that the continuous rated output and the short time rated output are constants determined for each spindle motor 904. The continuous rated output and the short time rated output are registered in the parameters 341 in advance by the operator and read out and used by the duty-cycle-calculation processing unit 41 according to the processing at step S6.
Subsequently, the duty-cycle-calculation processing unit 41 determines whether the cycle time obtained by the processing at step S5 is smaller than the duty cycle time obtained by the processing at step S6 (step S7). When the cycle time is smaller than the duty cycle time, this means that the spindle motor 904 overheats when continuous machining is performed. When the cycle time is smaller than the duty cycle time (Yes at step S7), the duty-cycle-calculation processing unit 41 calculates the wait time setting value Tw using Formula 2 below (step S8).
Wait time setting value Tw=duty cycle time−cycle time (2)
When the cycle time is larger than the duty cycle time (No at step S7), the duty-cycle-calculation processing unit 41 sets the wait time setting value Tw to a zero value (step S9). Note that the duty-cycle-calculation processing unit 41 records the calculated wait time setting value Tw in the shared area 345.
After the processing at step S8 or step S9, the interpolation processing unit 38 determines whether a value of the number-of-machined-pieces counter stored in the shared area 345 has reached a planned number of machined pieces set in advance in the parameters 341 or the like (step S10). When the value of the number-of-machined-pieces counter has not reached the planned number of machined pieces (No at step S10), the delay unit 381 delays the start of the next machining by the wait time setting value Tw (step S11). Specifically, after staying on standby until the wait time setting value Tw elapses, the delay unit 381 issues a cycle start for starting the next machining. In this case, when the zero value is set in the wait time setting value Tw, the delay unit 381 issues the cycle start without a waiting time.
When the value of the number-of-machined-pieces counter has reached the planned number of machined pieces (Yes at step S10), the interpolation processing unit 38 initializes (zero-clears) the value of the number-of-machined-pieces counter (step S12), and the operation of the numerical control apparatus 1 ends.
As explained above, according to the first embodiment of the present invention, the numerical control apparatus 1 includes the cycle-time measuring unit 382 that measures a cycle time of machining of a work, the current-amount measuring unit that measures a current amount per a unit cycle flowing to the spindle motor 904, the cycle-time calculating unit that calculates, on the basis of the measured current value per the unit cycle, a duty cycle time in which suppression of the occurrence of overheating of the spindle motor 904 is guaranteed, the duty-cycle-calculation processing unit 41 functioning as the processing unit that determines on the basis of the comparison of the duty cycle time and the cycle time whether the spindle motor 904 overheats, and the delay unit 381 that delays, when the duty-cycle-calculation processing unit 41 determines that the spindle motor 904 overheats, a start of the next cycle by the wait time setting value Tw obtained by subtracting the cycle time from the duty cycle time. Consequently, the numerical control apparatus 1 can suppress occurrence of overheating of the spindle motor 904 without a prior experiment and an input of a detailed current/temperature characteristic of each motor. That is, the numerical control apparatus 1 can avoid overheating of the spindle motor 904 as easy as possible.
Note that the delay unit 381 is explained as delaying the start of the next cycle by the wait time setting value Tw. However, a delay amount can exceed the wait time setting value Tw.
The numerical control apparatus 1 further includes the storing unit 34 that stores in advance rated outputs (a continuous rated output and a short time rated output) of the spindle motor 904. The cycle-time calculating unit calculates a duty cycle time using the rated outputs of the spindle motor 904 stored by the storing unit 34. Consequently, the numerical control apparatus 1 can suppress the occurrence of overheating of the spindle motor 904 without a prior experiment and an input of a detailed current/temperature characteristic of each motor.
Second Embodiment.
As shown in the figure, a numerical control apparatus 2 in the second embodiment is different from the first embodiment in that the delay unit 381 is omitted from the interpolation processing unit 38, in that a halt-time-variable setting unit 371 is added to the analysis processing unit 37, and in that a machining program 346 is stored in the storing unit 34 in advance instead of the machining program 343.
The halt-time-variable setting unit 371 substitutes the wait time setting value Tw calculated by the duty-cycle-calculation processing unit 41 for the variable for designating the halt time. The analysis processing unit 37 analyzes the dwell command, to the variable of which the wait time setting value Tw is set, and outputs an analysis result for delaying the start of the next cycle by the wait time setting value Tw. That is, according to the second embodiment, the analysis processing unit 37 including the halt-time-variable setting unit 371 functions as a delay unit.
As shown in
When it is determined that the value of the number-of-machined-pieces counter has reached the planned number of machined pieces (Yes at step S30), at step S33, processing same as the processing at step S12 in the first embodiment is executed and the operation of the numerical control apparatus 2 ends.
In this way, according to the second embodiment of the present invention, the storing unit 34 stores in advance the machining program 346 including, before the rewind command (a rewind code), the dwell command (a halt code) for halting the machining by a delay amount to be set later. The halt-time-variable setting unit 371 sets the wait time setting value Tw to the delay time of the dwell command. Consequently, when there is a risk of occurrence of overheating, a halt time is inserted for the wait time setting value Tw in every one cycle machining. Therefore, the numerical control apparatus 2 can suppress the occurrence of overheating of the spindle motor 904.
Third Embodiment.
A numerical control apparatus in a third embodiment of the present invention executes a machining program by one cycle to display a value (hereinafter, margin time) obtained by subtracting a cycle time from a cycle time (a duty cycle time) in which it is guaranteed that the spindle motor 904 does not overheat. When the margin time is a minus value, the numerical control apparatus can display a warning (hereinafter, duty cycle warning) to the effect that the spindle motor 904 is likely to overheat soon.
The duty-cycle-display processing unit 412 subtracts the duty cycle time from the cycle time to calculate a margin time Td and displays the calculated margin time Td on the display unit 10. The duty-cycle-warning processing unit 413 determines whether the margin time Td is a minus value. If the margin time Td is the minus value, the duty-cycle-warning processing unit 413 displays the duty cycle warning on the display unit 10.
Thereafter, the duty-cycle-warning processing unit 413 determines whether a value of the margin time Td is a minus value (step S48). When the margin time Td is the minus value (Yes at step S48), the duty-cycle-warning processing unit 413 displays the duty cycle warning on the display unit 10 according to a method same as step S47 (step S49) and the operation of the numerical control apparatus 3 ends. When the value of the margin time td is a plus value (No at step S48), the processing at step S49 is skipped.
As explained above, according to the third embodiment of the present invention, the numerical control apparatus 3 includes the duty-cycle-warning processing unit 413 that displays a warning when the value obtained by subtracting the duty cycle time from the cycle time is a minus value. Consequently, the operator can learn in advance, simply by executing the machining program 343 for one cycle, whether it is likely that the spindle motor 904 overheats when the machining program 343 is continuously operated.
The numerical control apparatus 3 includes the duty-cycle-display processing unit 412 that displays the duty cycle time and the cycle time or a difference value between the cycle time and the duty cycle time.
Consequently, even when the spindle motor 904 does not overheat, the operator can learn a margin degree until overheating of the spindle motor 904 and can refer to the margin degree when the operator reduces the cycle time of the machining program 343.
Fourth Embodiment.
The spindle-position-command check unit 372 determines whether position commands for orient, a C axis, and the like are present between spindle rotation commands (rotation commands based on speed commands) in the machining program 343.
When it is determined that the position command is absent between the spindle rotation commands, in order to reduce the duty cycle time, the acceleration/deceleration processing changing unit 431 changes acceleration/deceleration processing of the spindle motor 904 so as not to execute a part or all of deceleration processing immediately before a section between the spindle rotation commands and a part of all of acceleration processing immediately after the section and to continue the rotation of the spindle motor 904 between the spindle rotation commands.
As shown in
Note that the acceleration/deceleration processing changing unit 431 can change the acceleration and deceleration processing to gently increase speed at fixed acceleration from a fixed speed rotation state for the rotation section 1411 to a fixed speed rotation state for the rotation section 1412.
Note that a section in which the motor stops between two rotation periods based on speed control and position control is absent between the two rotation periods such as a section between the rotation section 1311 and the rotation section 1312 and a section between the rotation section 1411 and the rotation section 1412 is referred to as a spindle stop section.
As shown in
Subsequently, in processing at step S54 to step S56, kinds of processing same as the kinds of processing at step S4 to step S6 are respectively executed. After the processing at step S56, as in the processing at step S7, the duty-cycle-calculation processing unit 41 determines whether the cycle time is smaller than the duty cycle time (step S57).
When it is determined that the cycle time is smaller than the duty cycle time (Yes at step S57), the acceleration/deceleration processing changing unit 431 determines presence or absence of a spindle stop section on the basis of the information stored in the shared area 345 by the processing at step S53 of the spindle-position-command check unit 372 (step S58). When the spindle stop section is present (Yes at step S58), the acceleration/deceleration processing changing unit 431 combines a deceleration period and an acceleration period before and after the spindle stop section and reduces the number of acceleration and deceleration (step S59). When the spindle stop section is absent (No at step S58), the processing at step S59 is skipped.
When it is determined in the determination processing at step S57 that the cycle time is larger than the duty cycle time (No at step S57), both of the processing at step S58 and the processing at step S59 are skipped.
Thereafter, the numerical control apparatus 4 executes an operation in a second cycle in the flowchart of
As explained above, according to the fourth embodiment of the present invention, the numerical control apparatus 4 is provided with the acceleration/deceleration processing changing unit 431 that determines presence or absence of the spindle stop section and, when the spindle stop section is present, changes the acceleration and deceleration processing for the spindle motor 904 so as not to execute a part or all of deceleration processing immediately before the spindle stop section and a part or all of acceleration processing immediately after the spindle stop section and to continue the rotation of the spindle motor 904 during the spindle stop section. Consequently, because the duty cycle time can be reduced, it is possible to reduce a halt time between cycle times as much as possible.
Fifth Embodiment.
With a numerical control apparatus in a fifth embodiment, the operator can learn, simply by performing machining one cycle, the number of machined pieces available until the spindle motor 904 overheats.
The continuous operation time information 347 is information describing a relation between an electric current flowing to the spindle motor 904 and the time until the occurrence of overheating of the spindle motor 904 in a state in which the electric current flows. The continuous operation time information 347 is described by, for example, a lookup table or a function. The number-of-machined-pieces estimating unit 411 calculates time in which continuous machining is possible referring to the continuous operation time information 347 using the average of the electric current of the spindle motor 904 and divides the calculated time by the cycle time to calculate the number of pieces that can be continuously machined.
After the processing at step S74, the number-of-machined-pieces estimating unit 411 calculates an average current value of the spindle motor current acquired at step S72 (step S75). The number-of-machined-pieces estimating unit 411 calculates, referring to the continuous operation time information 347 stored in the shared area 345, the number of machined pieces that can be continuously machined until the spindle motor 904 overheats (step S76).
For example, when the average current value of the spindle motor 904 is 70%, according to the relation shown in
After the processing at step S76, the numerical control apparatus 5 ends the operation.
As explained above, according to the fifth embodiment of the present invention, the numerical control apparatus 5 includes the storing unit 34 that stores in advance the continuous operation time information 347 that describes a relation between an electric current flowing to the spindle motor 904 and time until the occurrence of overheating of the spindle motor 904 in a state in which the electric current flows, the cycle-time measuring unit 382 that measures a cycle time, the duty-cycle-calculation processing unit 41 functioning as the current-amount measuring unit that measures a current amount per a unit cycle flowing to the spindle motor 904, and the number-of-machined-pieces estimating unit 411 that estimates, on the basis of a cycle time measurement value by the cycle-time measuring unit, a current amount measurement value by the current-amount measuring unit, and the continuous operation time information, the time in which a work can be continuously machined or the number of machined pieces of the work that can be continuously machined without causing overheating of the spindle motor 904 and displays the time or the number of machined pieces. Consequently, the operator can learn, at a stage when one work has been machined, an estimated value of the time or the number of machined pieces until the occurrence of overheating of the spindle moor 904. Therefore, when the operator desires to machine several to several ten works, the operator can determine whether the machining is possible.
Sixth Embodiment.
Consequently, as shown in
Seventh Embodiment.
Subsequently, the delay unit 385 delays a cycle start of the next machining by the calculated machining halt time Tk (step S93). When the overload warning for the spindle motor 904 has not been generated (No at step S91) or after the processing at step S93, the delay unit 385 executes the determination processing at step S91 again.
In this way, according to the seventh embodiment, the numerical control apparatus 7 includes the cycle-time measuring unit 382 that measures a cycle time and the delay unit 385 that delays, when an overload warning for the spindle motor 904 has been generated, a start of the next cycle until the time of a value obtained by multiplying a measurement value of the cycle time by the cycle-time measuring unit 382 with the remaining number of pieces to be machined elapses. Consequently, it is possible to obtain effects same as the effects in the sixth embodiment.
As explained above, the numerical control apparatus according to the present invention is suitably applied to a numerical control apparatus that repeatedly executes a machining program.
1 to 7 Numerical control apparatuses
10 Display unit
20 Input operation unit
30 Control operation unit
31 Screen processing unit
32 Input control unit
33 Data setting unit
34 Storing unit
35 Machine-control-signal processing unit
37 Analysis processing unit
36 PLC (Programmable Logic Controller)
38 Interpolation processing unit
41 Duty-cycle-calculation processing unit
42 Axis-data input/output unit
43 Acceleration/deceleration processing unit
90 Driving unit
91 X-axis-servo control unit
92 Z-axis-servo control unit
94 Spindle-servo control unit
95 X-axis position sensor
96 Z-axis position sensor
97 Spindle sensor
341 Parameters
343, 346 Machining programs
344 Screen display data
345 Shared area
347 Continuous operation time information
371 Halt-time-variable setting unit
372 Spindle-position-command check unit
381, 383, 385 Delay units
382 Cycle-time measuring unit
411 Number-of-machined pieces estimating unit
412 Duty-cycle-display processing unit
413 Duty-cycle-warning processing unit
431 Acceleration/deceleration processing changing
unit
901 X-axis servo motor
902 Z-axis servo motor
904 Spindle motor
1311, 1312, 1313, 1314, 1411, 1412, 1413, 1414 Rotation sections
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/JP2012/069881 | 8/3/2012 | WO | 00 | 1/29/2015 |
Publishing Document | Publishing Date | Country | Kind |
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WO2014/020763 | 2/6/2014 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
4531524 | Mioduski | Jul 1985 | A |
5209110 | Sano et al. | May 1993 | A |
5968102 | Ichimaru | Oct 1999 | A |
6257348 | Momochi et al. | Jul 2001 | B1 |
20060207979 | Daniel | Sep 2006 | A1 |
20070081800 | Hsiang | Apr 2007 | A1 |
Number | Date | Country |
---|---|---|
03-180779 | Aug 1991 | JP |
07-274383 | Oct 1995 | JP |
10-080055 | Mar 1998 | JP |
10-279204 | Oct 1998 | JP |
11-216640 | Aug 1999 | JP |
11-262289 | Sep 1999 | JP |
11-341850 | Dec 1999 | JP |
11341850 | Dec 1999 | JP |
2000-176696 | Jun 2000 | JP |
2001-150200 | Jun 2001 | JP |
3212510 | Sep 2001 | JP |
2010-102416 | May 2010 | JP |
Entry |
---|
Japanese Office Action for JP 2012-557738 dated Feb. 5, 2013. |
International Search Report for PCT/JP2012/069881 dated Oct. 16, 2012. |
Number | Date | Country | |
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20150194805 A1 | Jul 2015 | US |