JP2004102568A - Numerical value control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily set a position for monitoring condition of a motor such as the load torque. <P>SOLUTION: Sequence numbers of a block wherein the load torque of a spindle motor and a servo motor of a feeding shaft is to be monitored is previously set. When the sequence numbers of the block during the execution coincide with the set number (a1), a determination whether a positioning command (G00) is output or not is done (a2). In the case of YES, the load torque of the servo motor of the feeding shaft during the operation is measured and stored (a4). In the case of NO, the load torque of the spindle motor and the servo motor of the feeding shaft during the operation are measured and stored (a3). Load torque measuring position is easily set by only setting the sequence number. Since arrangement of an auxiliary function for measuring the load torque during the execution of a working program is unnecessary, the working program is easily changed without giving an influence to the working cycle time. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a numerical controller having a monitoring function of monitoring a state of a motor of a machine controlled by the numerical controller.
[0002]
[Prior art]
A numerical control device having a function of detecting breakage or wear of a tool or wear of a movable portion (feed shaft) of a machine by monitoring a load torque of a motor of a main shaft or a feed shaft of a machine tool controlled by the numerical control device. Are already known.
In this function, it is necessary to specify a part for monitoring the load torque from various machine operations in the machining program depending on an object to be detected. For example, to detect wear and breakage of a drill, it is necessary to monitor the load torque of the spindle and feed shaft motors during cutting, such as monitoring the load torque during drilling. It is necessary to specify the operation such as. Further, in order to monitor the wear or the like of the movable portion (feed shaft) of the machine, it is necessary to specify an operation capable of detecting the torque required for feeding the movable portion.
[0003]
Therefore, conventionally, a portion of the machining program in which the load torque is to be measured and monitored is specified using an auxiliary function (M code), and the load torque monitoring signal is turned ON / OFF by this auxiliary function. In the machining program, an auxiliary function to turn on this signal is placed at the beginning of the program where the load torque is to be monitored, and an auxiliary function to turn off this signal is placed at the end of the load torque monitoring point. In addition, the monitoring location of the load torque is designated by a program command.
[0004]
[Problems to be solved by the invention]
The location where the load torque is monitored can be freely specified by the program command. However, the ON / OFF auxiliary function must be placed before and after the location where the load torque is monitored in the program. As the number increases, the program work requires a great deal of effort. Also, changing the program requires similar work. Further, there is a problem that a load torque cannot be monitored for a program that has already been created and has no auxiliary function for monitoring the load torque.
[0005]
When the numerical control device executes the auxiliary function, signals are transferred from the numerical control unit to the programmable controller and from the programmable controller to the numerical control unit in the numerical control device. Increases, the time required to transfer the signal increases, and the cycle time of machining increases.
[0006]
Therefore, an object of the present invention is to improve the above-described problems of the prior art, to easily set a position for monitoring the state of the motor such as a load torque, and to have no particular effect on a machining cycle time, and to reduce a motor such as a load torque. It is an object of the present invention to provide a numerical control device capable of monitoring the state of a computer.
[0007]
[Means for Solving the Problems]
The invention according to claims 1 to 4 is a numerical controller having a function of monitoring a motor state such as a load torque of the motor, and inputs a sequence number of a block in the machining program for monitoring the state of the motor. Sequence number input means, a sequence number storage means for storing a sequence number input by the sequence number input means, and a sequence number of a block during execution of a machining program and a sequence number stored in the sequence number storage means. When the sequence number comparing unit and the sequence number comparing unit detect a match between the currently executed sequence number and any of the sequence numbers stored in the sequence number storing unit, the sequence number comparing unit executes a command corresponding to the sequence number. Means for monitoring the state of the motor such as load torque. In the ease of setting locations for monitoring the state of the load torque or the like, and as the state of the motor can be easily monitored. In particular, in the machine tool, the means for monitoring the state of the motor is configured such that if the command corresponding to the sequence number is a positioning command, the state of the motor of the feed axis being operated is determined. The state of the motor of the middle feed shaft is monitored.
[0008]
Also provided are motor information selection means for setting motor selection information for specifying a motor whose motor status is to be monitored in association with a sequence number, and motor selection information storage means for storing the set motor selection information. When the sequence number of the program being executed matches one of the sequence numbers stored in the sequence number storage means, the load torque of the selected motor and the like are determined according to the motor selection information corresponding to the matched sequence number. To monitor the status.
[0009]
The invention according to claims 5 and 6 is a numerical control device having a load torque monitoring function of a feed motor and a spindle motor, wherein the operation of a block in a machining program being executed is an operation other than a positioning operation or a positioning operation. And a means for monitoring the load torque of the feed motor during the positioning operation when the positioning operation detecting means detects that the positioning operation is being performed. Further, in a machining program, sequence number input means for inputting a sequence number of a block that does not monitor the load torque of the feed motor, sequence number storage means for storing a sequence number input by the sequence number input means, A sequence number comparing means for comparing the sequence number of the block in which the machining program is being executed with the sequence number stored in the sequence number storing means, and the means for monitoring the load torque is executed by the sequence number comparing means. When a match between the sequence number and the sequence number stored in the sequence number storage means is detected, the load torque of the feed motor during operation is not monitored.
The sequence number input means is composed of a display device connected to the numerical control device and an operation panel with data input means.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a block diagram showing a main part of a numerical controller according to an embodiment of the present invention and a main part of a machine tool controlled by the numerical controller.
The numerical control device 10 includes a processor 11, a ROM 12, a RAM 13, a servo control unit 14, a display / touch panel control unit 15, a spindle control unit 16, and the like. The processor 11 reads a system program stored in the ROM 12, and controls the numerical control device as a whole according to the system program. The RAM 13 stores temporary calculation data, display data, machining programs input from an input interface (not shown), and the like. It is memorized. The display / touch panel control unit 15 includes a current position of each axis of the machine tool, an alarm, various parameters, image signals such as image data, and further, in relation to the present invention, a measured load torque, an average value of the load torque, A signal such as the maximum value of the load torque is transmitted to the display 21 with the touch panel. The display unit 21 with a touch panel performs a display function and a function of a data input unit, and displays the above-described various information on the display unit 21 with a touch panel. Further, as will be described later, it constitutes a setting input means for setting a sequence number for measuring the load torque, a limit value of the load torque for issuing an alarm, and the like.
[0011]
The servo control unit 14 includes a processor, a memory such as a ROM and a RAM, and the like. Each of the feed axes (in this embodiment, orthogonal X, X, and Z) sent from the main processor 11 of the numerical controller 10 is based on a machining program. In this case, each axis servo motor Mx, My, Mz is driven via a servo amplifier 22x, 22y, 22z for each axis.
[0012]
Each of the servo motors Mx, My, and Mz of each feed axis has a built-in pulse encoder for detecting position and speed, and each of the servo amplifiers 22x, 22y, and 22z has a drive of each servo motor Mx, My, and Mz. A current detector for detecting a current is provided. The servo control unit 14 performs each process of the position loop, the speed loop, and the current loop based on the movement command from the main processor 11 and the position, speed, and current feedback signals from each pulse encoder and each current detector. Then, the positions and speeds of the servo motors Mx, My, and Mz of each feed axis are controlled. Further, a disturbance estimation observer is incorporated in the processor of the servo control unit, and the load torque of each feed shaft is estimated by the observer.
[0013]
The spindle control unit 16 rotates the spindle motor Ms at a commanded rotation speed via a spindle amplifier 23 based on a spindle rotation command and orientation commands from the main processor 11 and a feedback signal from a position coder (not shown). In addition, the rotational position of the spindle motor Ms is positioned at a predetermined position by an orientation command. Also, a disturbance estimation observer is incorporated in the spindle control unit 16 to estimate and detect the load torque applied to the spindle motor Ms.
[0014]
The hardware configurations of the numerical controller 10 and the machine tool described above are not different from those of the related art, and the sequence numbers and the like input and set in the RAM 13 from the display 21 with a touch panel as an operation panel are related to the present invention. Is different from the conventional numerical controller in that a memory unit is provided for storing the load torque of each feed shaft motor and the spindle motor when the block of the set sequence number is executed. .
[0015]
First, in the machining program, the sequence number of the block for measuring the load torque is input and set from the display 21 with a touch panel. In order to monitor the breakage or wear of the tool, the main spindle when the workpiece is cut by the tool, that is, when a block of a cutting command (G01, G02, G03, G94, etc.) is executed. If the load torque of the motor and the motor of the feed shaft is monitored, breakage and wear of the tool can be detected.
[0016]
Also, during execution of the block of the positioning (rapid feed) command (command of G00), the cutting of the workpiece by the tool is not performed, and the feed axis is driven by rapid feed. By measuring the load torque of the servomotor of the feed shaft which is rapidly fed to the feed shaft, it is possible to detect the wear of the movable portion of the machine driven by the feed shaft.
[0017]
Therefore, the display 21 with the touch panel is switched to the sequence number setting screen, and the sequence number of the block for monitoring the load torque is input and set for the machining program to be operated. FIG. 5 is an example showing a storage state of the sequence number storage unit of the sequence number (Nxxxx) input and set as described above.
[0018]
When the operation of the machine tool is started and the machining program is executed, the processor 11 executes the process shown in FIG. 2 at predetermined intervals. First, it is determined whether or not the sequence number of the currently executing block exists in the sequence number set in the sequence number storage unit (step a1). If there is no match, the process in the processing cycle ends. On the other hand, if a sequence number that matches the sequence number of the currently executing block is set and stored, it is determined whether the command of the currently executing block is a positioning (fast-forward) command (G00 command) (step a2), and positioning is performed. If so, the load torque of the servomotor of the feed axis driven by the block being executed is measured and stored in the RAM 13 (step a4).
If it is determined in step a2 that the command is not a positioning command, that is, it is determined that the feed is cutting, the load torque of the spindle motor Ms and the servomotor of the feed shaft being executed in the block is measured and stored in the RAM 13 (step a3).
[0019]
As described above, the servo control unit 14 and the spindle control unit 16 incorporate a disturbance estimation observer for the servo motors Mx, My, and Mz of the respective feed axes and a disturbance estimation observer for the main spindle motor Ms. Load torque applied to the feed shaft motors Mx, My, Mz and the main shaft motor Ms is required. The load torque obtained by the observer is obtained in steps a3 and a4 and stored in a predetermined storage unit of the RAM 13.
[0020]
The load torques of the spindle motor Ms and the servomotors Mx, My, and Mz of the feed axes measured and stored in this manner are different from those of FIG. The current value, average value, and maximum value are obtained. When the display 21 with the touch panel is set on the load torque display screen, the current value, the average value, and the maximum value are displayed on the screen for each of the spindle motor and the motor of each feed axis. When the maximum value of the measured load torque exceeds a preset limit value, an alarm signal is issued to change the display color. The average value and the maximum value are obtained and the current value, average value and maximum value of the load torque are displayed, and the alarm display when the measured load torque maximum value exceeds the limit value is the same as the conventional one. Detailed description is omitted.
[0021]
In the above-described first embodiment, the load torque of the motor operating in the block of the set sequence number is measured. However, in the second embodiment shown in FIG. Then, the load torque of the servomotor of the feed shaft is measured. At the time of the positioning (rapid traverse) operation, all the load torques of the servomotors of the feed shaft during the operation may be automatically measured. However, the purpose of measuring the load torque of the servomotor of the feed shaft is mainly to detect wear and the like of the movable portion of the feed shaft driven by the servomotor, and the load torque is measured over the front movement region of the feed shaft. It is necessary to obtain the load torque of the above. However, when the moving amount (fast-forwarding moving amount) is small and repeated, the load torque cannot be a factor indicating the wear of the movable part due to the influence of acceleration and deceleration, and conversely. In the positioning automatic measurement mode, set a sequence number that does not measure load torque in order to prevent it from being a factor that hinders wear detection and to prevent measurement for some other reason and not to include it in the average value of load torque. However, when the positioning block of the set sequence number is executed, the load torque is not measured in the second embodiment. Therefore, in the second embodiment, for the positioning command block, a sequence number for not measuring the load torque is set, and for the positioning command block, a sequence number for measuring the load torque is set for the cutting feed command. Will do.
[0022]
The processor 11 of the numerical control device 10 executes the processing shown as a flowchart in FIG. 3 at predetermined intervals.
First, it is determined whether or not the positioning automatic measurement mode has been set (step b1). If not set, the same processing as that of the first embodiment shown in FIG. 2 is executed. That is, steps b5, b6, and b7 in FIG. 3 are the same as the processing in steps a1, a2, and a3 of the processing shown in FIG. The processing in step b4 is the same as the processing in step a4 in FIG.
[0023]
If the positioning automatic measurement mode is set, it is determined whether the block currently being executed is a block of a positioning command (G00 command) (step b2). If is set, the load torque of the spindle motor Ms and the servomotor of the feed shaft in operation is measured and stored (step b7). If the sequence number has not been set, the process of the cycle is terminated as it is from step b5.
[0024]
On the other hand, when it is determined in step b2 that the block of the positioning command is being executed, it is determined whether or not the sequence number of the block is set (step b3). The load torque of the servomotor of the feed shaft that has been output is measured and stored (step b4). However, if it is detected in step b3 that the sequence number has been set, the processing of the cycle ends without measuring the load torque.
[0025]
As described above, in the second embodiment, if the positioning automatic measurement mode is not set, in the block of the cutting feed command in which the sequence number is set, the spindle motor and the servo motor of the active feed axis are set. In the positioning block in which the load torque is measured and the sequence number is set, the load torque of the servo motor of the feed axis which is instructed and operated by the block is measured and stored.
[0026]
If the positioning block is set to the automatic positioning measurement mode, the measurement of the load torque of the servo motor of the feed axis during operation is standard in the positioning block. The load torque of the servo motor is not measured. In the block of the cutting feed command in which the sequence number is set, the load torques of the spindle motor and the servomotor of the feed shaft are measured. In the positioning automatic measurement mode, when measuring the load torque of the servo motor of the feed shaft operating in all the positioning blocks in all the positioning blocks, the processing in step b3 is omitted, and the positioning block is being executed in step b2. When the determination is made, the process proceeds to step b4.
[0027]
In the first and second embodiments described above, the load torque of the spindle motor Ms and the servomotors Mx, My, and Mz of each feed shaft are measured based on the set sequence numbers. In addition, in the positioning block, the load torque of the servomotor of the feed shaft operating in the block is measured, and in the block of the cutting feed, the load torque of the spindle motor and the servomotor of the feed shaft in operation is measured.
[0028]
However, in order to determine the state of the spindle or the state of a specific feed axis, there is a case where it is desired to measure only the load torque of the spindle motor or the load torque of the servo motor of the specific feed axis. In a third embodiment described below, by specifying a motor for setting a sequence number and a load torque, only the load torque of the specified motor is measured during the operation of the block of the specified sequence number. I do.
[0029]
FIG. 6 is an explanatory diagram of a sequence number for measuring a load torque and an example of setting a motor according to the third embodiment. The display screen of the display unit 21 with the touch panel is used as a setting screen, and the sequence number for measuring the load torque and the information of the motor to be measured are input and set. As shown in FIG. 6, the RAM 13 stores the input sequence numbers and information of the motors to be measured in the blocks of the sequence numbers. In FIG. 6, "Nxxxx" is a sequence number, and M1 and M2 are main shaft motors Ms and feed shaft servomotors Mx. My. It is motor information indicating Mz.
[0030]
FIG. 4 is an operation flowchart of the third embodiment. When the numerical control device 10 starts operating, the process shown in FIG. 4 is executed at predetermined intervals. First, it is determined whether or not the sequence number of the block currently being executed matches the set sequence number (step c1). If not, the process of the cycle ends as it is. If they match, the load torque of the motor corresponding to the motor information set corresponding to the matched sequence number is measured and stored (step c2).
[0031]
The above processing is executed at predetermined intervals. Then, the average value of the stored load torques and the maximum value of the load torques are obtained, and displayed on the display screen of the display unit 21 with the touch panel.
[0032]
In the above-described embodiment, the example in which the load torque of the spindle motor and the servo motor of each feed shaft is monitored by the disturbance estimation observer to monitor the load torque is described. However, when the observer is not provided, the drive current of the motor is controlled. May be detected as the magnitude of the load torque. In this case, the motor drive current may be measured by measuring a current feedback signal detected and fed back by a current detector of each motor, or a current command (torque command) output from a speed loop is regarded as a load torque. You may make it measure.
[0033]
Furthermore, in addition to the load torque, the motor speed based on the speed feedback signal of the motor that is fed back and the speed command output from the position loop, the error amount (position error) obtained in the position loop processing, and thermal simulation The state of the motor such as the amount of heat obtained by the operation may be monitored by designating an operation block by a sequence number. For example, by measuring the speed, the amount of error, and the amount of heat of a spindle motor or a feed axis servomotor of a block that executes a specific operation, it is possible to monitor the motor operation state in the designated block.
[0034]
【The invention's effect】
The invention according to claims 1 to 3 of the present application can measure a load torque of a motor that operates in a desired block in a machining program by designating a sequence number. Since it is not necessary to specify the measurement point of the program, the required load torque can be easily measured. Further, since the auxiliary function is not used, it is not necessary to exchange a signal with the programmable controller when executing the auxiliary function, so that a cycle time for processing or the like can be shortened. Since it is only necessary to specify the sequence number, the location where the load torque is measured can be changed arbitrarily. Also, the load torque can be measured by specifying a sequence number for a conventional program in which an auxiliary function for measuring the load torque is not incorporated in the program.
[0035]
Further, in the invention according to claims 4 and 5 of the present application, at the time of the positioning operation, the load torque of the servomotor of the feed shaft driven by the positioning operation is automatically measured. In this case, it is also possible to specify a sequence number, select a block that does not measure the load torque even in the positioning operation, and select only a block suitable for detecting the degree of wear of the load torque indicating the wear of the movable portion of the feed shaft. it can.
[Brief description of the drawings]
FIG. 1 is a block diagram of a main part of a numerical controller according to an embodiment of the present invention and a main part of a machine tool controlled by the numerical controller.
FIG. 2 is a processing flowchart according to the first embodiment of the present invention.
FIG. 3 is a processing flowchart according to a second embodiment of the present invention.
FIG. 4 is a processing flowchart according to a third embodiment of the present invention.
FIG. 5 is an explanatory diagram showing a sequence number setting storage state in the first and second embodiments of the present invention.
FIG. 6 is an explanatory diagram illustrating a set sequence number and a storage state of motor information according to a third embodiment of the present invention.
[Explanation of symbols]
10 Numerical control device 21 Display with touch panel 22x, 22y, 22z Servo amplifier Mx, My, Mz Servo motor Ms Spindle motor

Claims (7)

A numerical controller having a motor status monitoring function,
Sequence number input means for inputting a sequence number of a block in the machining program for monitoring the state of the motor;
Sequence number storage means for storing a sequence number input by the sequence number input means,
Sequence number comparing means for comparing the sequence number of the block during execution of the machining program with the sequence number stored in the sequence number storing means,
When the sequence number comparing means detects a match between the currently executed sequence number and one of the sequence numbers stored in the sequence number storage means, the state of the motor is monitored by a command corresponding to the sequence number. And a means for controlling the numerical value. Means for monitoring the state of the motor is: if the command corresponding to the sequence number is a positioning command, the motor status of the operating feed shaft; if not, the main motor and the motor of the operating feed shaft. The numerical control device according to claim 1, wherein the numerical control device controls a machine tool that monitors a state of the machine tool. A numerical controller having a motor status monitoring function,
Sequence number input means for inputting a sequence number of a block in the machining program for monitoring the state of the motor;
Sequence number storage means for storing a sequence number input by the sequence number input means,
Motor information selection means for setting motor selection information for identifying a motor whose motor status should be monitored in association with a sequence number;
Motor selection information storage means for storing the set motor selection information,
Sequence number comparing means for comparing the sequence number of the block during execution of the machining program with the sequence number stored in the sequence number storing means,
When the sequence number comparing unit detects a match between the currently executed sequence number and any of the sequence numbers stored in the sequence number storage unit, the motor selection information stored in the motor selection information storage unit is detected. A means for monitoring the state of the selected motor in accordance with the motor selection information corresponding to the sequence number in which the match is detected. 4. The numerical controller according to claim 1, wherein the monitored state of the motor is a load torque of the motor. What is claimed is: 1. A numerical controller having a load torque monitoring function of a feed motor and a spindle motor, comprising: a positioning operation detecting means for determining whether an operation of a block in a processing program being executed is a positioning operation or an operation other than a positioning operation; Means for monitoring the load torque of the feed motor during the positioning operation when the detecting means detects that the positioning operation is being performed. Sequence number input means for inputting a sequence number of a block in the machining program, which does not monitor the load torque of the feed motor,
Sequence number storage means for storing a sequence number input by the sequence number input means,
Sequence number comparing means for comparing the sequence number of the block during execution of the machining program with the sequence number stored in the sequence number storing means,
The means for monitoring the load torque includes: when the sequence number comparing means detects a match between the sequence number being executed and the sequence number stored in the sequence number storage means, the load torque of the feed motor being operated. 6. The numerical control device according to claim 5, wherein monitoring of the numerical value is not performed. The numerical control device according to any one of claims 1 to 6, wherein the sequence number input means is a display device connected to the numerical control device and an operation panel using data input means.

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