JPS6149203A - Numerical control method - Google Patents

Abstract

PURPOSE:To improve the operability of a numerical control method by monitoring both the position coordinate value of a program command and the present position coordinate value of a machine and positioning the mobile part of the machine at a program position according to the data of said two coordinate values when a control start request is delivered. CONSTITUTION:A numerical controller contains a processor 101, a RAM103, an operating board 105, etc. and controls a machine tool 111 via a pulse distributor 107. In this case, the pulse distribution is calculated based on the path data included in an NC (numerical control) program. Then the mobile part of the machine tool is moved and also a pulse interpolation point is monitored as a program position. At the same time, the actual position of the machine tool is monitored as a slide position. Then the control is stopped and a manual operation is carried out for exchange of tools and check of the working state. Thus a difference is produced between said program and slide positions. Therefore the tool is shifted by an amount equal to said difference to obtain the coincidence between both positions. Then the numerical control is started at a stop point according to the NC program data.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a numerical control method, and in particular monitors both the position according to the program command (program position) and the weaving position (slide position), and issues a start request. Alternatively, the present invention relates to a numerical control method in which, when a restart request is made after manual intervention, the mechanical movable part is moved so that the slide position matches the program position, and then NC program control is started.

<Prior art> If a tool breaks during numerical control based on NC program data, or if you want to check the machining status, stop the numerical control process based on NC program data, and then manually release the tool. Then, tool exchange, machining check, and other processing are performed, and then machining based on the NC program data is resumed. By the way, conventionally, when restarting machining, the tool is positioned at the origin and numerical control is performed again from the beginning using NC program data. Also, another method is
In addition to registering a custom macro to execute tool exchange in advance, a sensor monitors tool breakage, stores the machine position when tool breakage is detected, and then returns the old tool to the tool exchange point under the control of the custom macro. is moved, the tool is replaced, a new tool is positioned at the tool breakage position, and machining is then restarted using the NC program data.

<Problems to be solved by the invention> However, in the first conventional method, when restarting machining, the machine is moved to the origin and machining is restarted from the beginning, which increases machining time and is cumbersome to operate. Met.

In addition, in the second method using a custom macro, tool breakage processing can be automatically performed, but the system is large-scale, resulting in high costs, and has the disadvantage that it cannot be applied to cases other than tool breakage processing.

In light of the above, an object of the present invention is to prevent the program from being interrupted during numerical control using NC program data due to tool breakage, manual GJ operation to check machining, etc., or machine failure (for example, disconnection of the position loop of the servo system). To provide a numerical control method capable of restarting numerical control processing based on NC program data from the program position even if the position of the machine (referred to as the program position) and the machine position (referred to as the slide position) are different.

Another object of the present invention is to constantly monitor both the program position and the slide position, and when there is a start request or restart request, use the position data of both positions ≧ before starting numerical control using NC program data. It is an object of the present invention to provide a numerical control method for moving a mechanical movable part to a programmed position and then performing numerical control.

Still another object of the present invention is to check the distance between the program position and the slide position or the positional deviation for each axis at the time of startup or restart, and if the distance or positional deviation is large, a startup request or restart request is made. An object of the present invention is to provide a numerical control method that can prevent the danger associated with long-distance movement of a mechanical movable part from a slide position to a program position.

Another object of the present invention is to provide a numerical control method that prevents the machine position from deviating from the programmed position during NC program control and has good operability with fewer machining errors.

Means for Solving the Problems> The numerical control method of the present invention comprises a position coordinate value on a program command that is updated based on NC program data and a machine position coordinate value that is updated based on the current position of the machine. , and when there is a request to start control based on NC program data, position the machine movable part to the program position based on the program position data and machine position data, and then execute NC control processing based on the NC program data. Consisted of.

Furthermore, the numerical control method of the present invention further checks whether the difference between the program position and the machine position is smaller than a predetermined tolerance when the start request is received, and when the difference is smaller than the tolerance, the machine is positioned at the program position, then NC control processing is performed based on the NC program data, and when the difference is greater than an allowable value, the start request is invalidated.

Function> A pulse distribution calculation is executed based on the path data included in the NC program data to move the mechanical movable part, and the pulse interpolation point is monitored as a program positive. Also, the actual machine position is similarly monitored as the slide position. For example, during control based on NC program data, the slide position is updated in the same way as the program position (the pulse interpolation point is set as the slide position), and when the moving part of the machine is moved by manual operation, or when the position loop is broken. When the movable parts of the machine move by themselves, the current position of the machine is monitored by a predetermined method and the slide position is updated. Therefore, based on the NC program data (in order to replace the tool if the tool breaks during control, or to check the machining condition), the control based on the N01 program data is stopped and manual operation is performed. If there is an intervention, the program position and the slide position will be different.In such a case, when the cycle start button is pressed to start (restart), the position if1 vote value of the program position and the slide position will be compared,
If the difference is less than the allowable value, the tool is moved by the difference t4 to match the slide position with the program position, and then numerical control processing is started from the stop point (program position) based on the NC program data. On the other hand, if the difference is above the allowable value, the start request is invalidated, and the tool is brought closer to the program position 1 by manual operation to bring it below the allowable value, and then the cycle start button is pressed again to start and stop. Numerical control processing based on the NC program data is started from the point.

<Example> FIG. 1 is a schematic explanatory diagram of the present invention, and in the figure WK;
TL is the tool, P is the program position, and 2% is the slide position.

During automatic operation based on NC program data, if the machine is operating normally, the program position P and slide position P match (see FIG. 1(A)).

However, if automatic operation is stopped for some reason, for example, to change a tool or check the machining status, and then the tool ゛rL is moved manually, the program position P and the slide position P will no longer match (the first (See Figure CB).

Now, after changing the tool or checking the machining status, press the cycle start button on the operation panel to start (restart), and the processor will control the position deviation between the program position P and the slide position 9 and 22. Calculate each axis and check whether they are below the allowable value (see Figure 1 (C)
)reference).

If the positional deviation of all the axes is less than the allowable value, the positional deviation of each axis is regarded as an incremental command value, and the tool TL is placed in the program position P. As a result, the slide position P matches the program position P again (see FIG. 1 (DJ)).

When the tool reaches the program position P, the processor resumes automatic operation control from the program position based on the NC program data (see FIG. 1(E)).

Note that if the positional deviation of at least one control axis is equal to or greater than the allowable value at the time of restart, the tool will not move toward the program position 1 and the startup request will be ignored.

This is a dangerous slant because if the positional deviation is large, the tool TL may come into contact with the workpiece WK or the operator when moving from the slide position P to the program position P0. Therefore, if the positional deviation is large, you must manually move the tool close to the programmed positionian and then press the cycle start button to start the cycle.Then the tool will move towards the programmed positional position in the same way as described above, and then start again. Automatic driving begins.

FIG. 2 is a block diagram of a numerical control i[D device to which the method of the present invention is applied. In the figure, 101 is a processor, 102 is a ROM that stores a control program, 103ξ is a RAM,
104 is a data reading device for reading NC program data from the NC tape NT, 105 is an operation panel, and 106 is a manual data input device (M
(referred to as DI neck), 1071; t pulse distributor, 108
X ~ 108Zf; servo circuit for each axis, 109x ~ 1
09Z is the motor of each axis, and 110x to 110Z are one pulse Fx, F, every time the corresponding motor rotates a predetermined amount.
,, a pulse cog that generates F2, 111 a machine tool, and 112 an interface circuit for exchanging data between the machine tool and the control device.

Each of the servo circuits 108x to 108Z has the same groove composition, and the difference E8 between the distributed pulse PxSP, F2 output from the pulse distributor 107 and the feed puncture pulses F6, Fv, F2 generated from the pulse cogs 110x to 110Z, It has error registers ERX, ERY, and ERZ that store E, f, and E, DA* converters DAX, DAY, and DAZ that output analog voltages proportional to the difference, and speed control circuits 5CXSSCY and SCZ.

The numerical control method of the present invention will be explained below according to the flowchart shown in FIG. Note that the symbols indicating the following steps are attached to the right shoulder of the corresponding blocks in the flowchart of FIG. Further, the NC program data is read from the NC tape NT by the data reading device 104 and sent to the RA.
Assume that it is already stored in M103. Furthermore, in the following, the feed hold switch on the operation panel 105 is operated during automatic operation based on NC program data to stop automatic operation, the tool is then moved by manual intervention, and after a predetermined operation, the cycle start chain is stopped. A case will be described in which a restart is performed, but the present invention is not limited to such a case.

(al Press the cycle start button on the operation panel 105 to start the cycle.) As a result, the processor 101 reads one block of NC data from the RAMU 103.

(bl The processor uses the read NC data as a code indicating the program end (for example, MO2 or M2O).
Check whether it contains 3.

(cl) If it is included, the numerical control process based on the NC program data ends.

(d) However, if the NC data does not include a code indicating program end, the processor checks whether the NC data is path data.

(elNc data is passage data (, M-, S-, T
- If it is a functional instruction, these are the interface circuit 112
Output to work 11 [1111 via.

When a signal indicating the end of the operation corresponding to the command is received from the machine tool via the interface circuit 112, the next NC data is read and the processing from step (bl) is repeated.

(fl In step (dl), if the NC data is path data, the following path control is executed.

(fl-1 First, the processor 101 starts each axis current position (x
.

Find Y, , Z,).

(fl-2 Then, using the incremental value of each axis and the command speed F, the time T
(For example, the amount of movement Δx1ΔY1ΔZ to be moved in each axis direction during 16 m5ecl is determined from the following formula 6 (% (2)), and these Δx1ΔY1ΔZ are input to the pulse distribution @107 for each time ΔT.

[The fl-3 pulse distributor 107 performs simultaneous three-axis pulse distribution calculations based on the input data and distributes the distributed pulses PA,
Generate P,,F2 and servo circuit 108X~10 of each axis
8Z to move the tool along the commanded path.

(fl-4 Also, the processor 101 stores RAM1 every ΔT seconds.
The current positions of each axis of the program position X1, Y, Z, stored in 03, and the current position of each axis of the slide position xffi, Yl, Z. , is updated by the following equation 6 (%(4)) (the sign depends on the direction of movement), and similarly, the remaining movement amounts x2, Y2, zl of each axis stored in the RAM 103 every ΔT seconds (the initial values are respectively X4, Y7, z
(10) is updated using the following formula (10).

(gl) In parallel with the processing of step [fl, the processor 101 checks whether an automatic operation stop signal has been generated, for example, whether the feed hold switch on the operation panel 105 has been pressed.

[hl If the automatic operation stop signal (feed hold signal) is not generated, the processor checks whether the following formula % formula % (13) is satisfied, and if the formula (]3 is not satisfied, step ffl Repeat the following process, and if the conditions are met, end the passage control process and proceed to the next NC.
Read data from RAM 103, and then step ff
Repeat the process after l.

(il) On the other hand, in step (gl), if the feed hold switch is pressed and a feed hold signal is generated, the processor 101 stores the state at that time (cutting state, positioning state, reset state), and
Thereafter, inputting ΔX, ΔY1ΔZ to the pulse distributor 107 is stopped. This (from this, Nervo circuit 108x~
Each axis motor rotates at a reduced speed until the pulses stored in the error registers ERX to ERZ of 108Z are discharged, and then stopped.

(]) After this, the processor 10'1 enters a manual mode, for example, a jog mode, and monitors whether a predetermined jog button is pressed (manual intervention).

+kl Processor 101 checks whether the cycle start button has been pressed (if a restart request has been made) without manual intervention.

Then, if a reboot is not requested, step (jl
Repeat the following process.

(m) On the other hand, if there is manual intervention (jitter feed) in step (''), the process 2 101 executes the following job feed processing.

(If the jog button is pressed, the ml-1 processor 101 reads the feed axis (x, y, z) and its direction (positive, negative) (+X axis direction), and sets parameters in advance. Using the jig feed speed F and ΔT, calculate the following formula % (14), output the ΔJ to the pulse distributor 107 every ΔT seconds as long as the +X jig button is pressed, + tools
Move in the X-axis direction.

+n11-2 In addition, in parallel with the above processing, the processor 101 multiplies the following formula % formula % (15) every ΔT seconds to obtain the slide positive X-axis position coordinate value xo
, update. Furthermore, if the -X direction button is pressed (
15) The sign of the formula becomes negative, and if the Y') Yog button or ±Z button is pressed, the formula (15) is replaced with the following formula Y + ΔJ-4Y (16) or the following formula % formula % (17) or more When the manual intervention is completed, the processor 101
Step (does the process and checks if a reboot is requested).

(n) The processor is in RA if a reboot is requested.
Using the coordinate values of each axis position of the program positive and slide positive stored in M103, the program positive 97 and the program positive 97 are calculated by the following formula % formula % (18).
Each axis position deviation x1y1z between 22% is calculated.

(Next, the processor 101 checks the state at the time when the feed hold signal is generated (cutting state, positioning state, reset state), and stores the allowable values Tx, T, ..., T2 of each axis according to the state from the RAM. It reads t!The allowable values for each axis are set and stored in advance by parameters.Also, the allowable values TX, T, T2 are set to appropriate values depending on the state when the automatic operation stop signal is generated. be done.

(p) After the calculation, the processor compares each axis tolerance value with each axis position deviation between the program position and the slide position, and checks whether the following formula % formula % (21) holds true.

(ql If the formula (21) holds true, in other words, the slide positionian P is the program position P.

X
5y1 Step with Z as incremental value for each axis (
A process similar to the path control shown in fl is performed (t is reached, and the positioning speed is rapid traverse speed F0) to position the tool at the program position. As a result, the axis position coordinate values of the slide position and the program position match, and thereafter the process returns to step ffl, and the numerical control process based on the NC program data is repeated again from the automatic operation stop point.

(rl On the other hand, at least 1 in step (pi)
If equation (21) does not hold for the axis, processor 1
01 invalidates the restart request and displays on the display screen of the MDI device 106 which axis is greater than or equal to the allowable value. Figure 4 is an image when the PO5- key on the MDI device 106 is pressed to display the current position on the display screen. ), each axis coordinate value of the slide positionian in the work coordinate system (displayed as SLIDE PO5), and each axis tolerance value (displayed as TOLERANCE) are displayed. If it is within the tolerance range, there will be no mark; if it is moving within the tolerance range, there will be one mark (*); if it is not within the tolerance range, there will be a mark 2 @ (**), and if it is moving in the opposite direction to within the tolerance range. If so, mark 3 (***)
is added after the corresponding axis coordinate value.

Thereafter, the operator looks at the display screen and determines which axes are not within the allowable range, and then sends a job to bring the axes into the allowable range. When the cycle start button is pressed after all axes are within the allowable range due to job feeding, equation (21) is satisfied and the processing from step (ql) onwards is performed.

Although the above description assumes that a feed hold signal is generated during automatic operation, the present invention is not limited to this case.
For example, it could also be applied when an external reset button is pressed. However, when the external reset button is pressed, the processor sets all the axis coordinate values of the program positive controller to 0 (the program positive controller coincides with the origin). Therefore, for example, if you press the external reset button before starting with the NG program and then start, the tool will be positioned at the workpiece coordinate system origin since the program position coincides with the origin, and from then on, the tool will be positioned at the workpiece coordinate system origin using the NC program data. Controlled position.

In addition, if the position loop is broken and the tool is moving by itself, the slide position is monitored using a well-known follow-up method, and if the cycle start button is pressed after an emergency stop and the cycle start button is pressed, the above-mentioned procedure will be performed. After processing, if all axes are within the allowable range, move the tool toward the programmed position, match the slide position and the programmed position, and then perform 'tfh operation, while even one axis is within the allowable range. It can also be configured to disable the activation request if it is not included.

Furthermore, although the case has been described in which the allowable value is set for each axis, it is also possible to configure the allowable value to be set based on the distance between the program position and the slide position.

<Effects of the Invention> As explained above, according to the present invention, the position coordinate values on the program command that are updated based on the NC program data and the machine position coordinate values that are updated based on the current position of the machine are monitored. However, when there is a request to start control based on the NC program data, the 4214 is positioned at the program position based on the program position data and the aim position data, and then the NC control process is executed based on the NC program data. By simply pressing a cycle start button, for example, and with a simple configuration, the machine movable parts can be brought into alignment with the programmed position (automatic operation stop position), and then machining can be resumed from that position.

Furthermore, according to the present invention, when a start request is received, it is checked whether the difference between the program position and the machine position is smaller than a predetermined tolerance, and if the difference is smaller than the tolerance, the machine moves the movable part during movement. The movable part of the machine is automatically positioned at the programmed position assuming that there is no danger of contact with the workpiece, and if the difference is greater than the allowable value, the start request is invalidated as there is a danger, and the machine position is manually adjusted. 1. It was configured so that the activation request came within the permissible range, and then the activation request was made valid. Safe numerical control processing can be performed.

Furthermore, according to the present invention, the machine position can reliably match the programmed position with a simple operation and machining can be continued thereafter. In other words, the machine position can continue machining without moving away from the programmed position. , processing efficiency <,
Processing can be done with fewer errors.

Further, according to the present invention, the tolerance range is determined for each axis, the difference between the program position and the machine position is determined for each axis, and it is displayed for each axis whether the difference is smaller than the tolerance value. Because of this configuration, it is easy to understand which axis needs to be fed by DB, and the operability is good.

[Brief explanation of drawings]

Fig. 1 is a schematic explanatory diagram of the present invention, Fig. 2 is a block diagram of a numerical control device to which the present invention is applied, Fig. 3 is a flowchart of the processing of the present invention, and Fig. 4 is an explanatory diagram of a display example. . WK...Work, TL...Tool, P...Program position P,...Slide position 3, 101...Processor, 103...RAM105.
...Operation panel, 107...Pulse distributor, patent originator
FANUC CORPORATION (1 other person) Agent Patent attorney Chiki Saito Figure 1 Figure 4

Claims (7)

[Claims] (1) When the position coordinate values on the program command that are updated based on the NC program data and the machine position coordinate values that are updated based on the current position of the machine are monitored, and a request to start control based on the NC program data is made. , a numerical control method characterized in that a machine is positioned at a programmed position based on program position data and machine position data, and then NC control processing is executed using NC program data. (2) The numerical control according to claim (1), wherein the program position is a pulse interpolation point when a pulse interpolation calculation is executed based on path data included in the NC program data. Method. (3) When the start request is received, check whether the difference between the program position and the machine position is smaller than a predetermined tolerance, and if the difference is smaller than the tolerance, position the machine at the program position. A numerical control method according to claim (1), characterized in that: (4) The numerical control method according to claim (3), wherein the start request is invalidated when the difference is larger than a tolerance value. (5) The difference between the program position and the machine position is determined for each axis, and it is checked for each axis whether the difference is smaller than a tolerance value. Numerical control method. (6) The numerical control method according to claim (5), characterized in that the allowable value is changed depending on the time of device reset, positioning, and cutting. (7) The numerical control method according to claim (5), characterized in that whether or not the tolerance is within the tolerance is displayed for each axis.