JPS61103735A - Interpolation system of numerical control device - Google Patents

Abstract

PURPOSE:To enable a device to perform smooth further accurate control, by providing a low speed and a high speed interpolator each driven in a fixed period and its synchronizing 1/n period and using the sum of a pulse, dividing an output into (n) parts, in a low speed side and an output pulse in a high speed side as an interpolator output. CONSTITUTION:A servo motion, feeding an electrode in a diesinking electric discharge machine performing swivel machining, requires a high speed responsive characteristic such that the electrode 2, for instance, is retractively controlled by detecting a short of a work 1 and the electrode and fed in a normal condition if the electrode restores its condition of the short, and the servo motion, being necessary for decreasing its period of calculation, performs a high speed arithmetic operation in every short period by using sub CPU of a high speed interpolator, promptly and accurately operating a servo motion control. while a swivel motion control or a jog feed and a quick feed or the like, using the main CPU of a low speed interpolator 6 and executing an arithmetic operation in each normal period, can be smoothlyexecuted with no influence to the servo motion control.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an interpolation method for a numerical control device, and particularly relates to processing not only in the feeding direction of an electrode.

``This invention relates to an interpolation method for a numerical control device that facilitates control in a die-sinking electric discharge machine that performs oscillating machining including the direction around the electrode.

(Prior technology) Normal die-sinking electrical discharge machining machine performs machining only in the feeding direction of the electrode, but in oscillating machining, the movement of the electrode is performed not only in the feeding direction of the electrode but also in the oscillating motion around the electrode. It is possible to perform machining operations that are not available in conventional electrical discharge machines by controlling the entire motion.The oscillating motion shape is not limited to circular motion, but also rectangular motion. I can make you do it.

By performing this type of oscillating machining, it is possible to carve a diameter larger than the actual diameter of the electrode, it is easier to remove sludge generated during machining, and it is possible to It has the advantage that it can be distributed over an area, thereby substantially reducing the consumption of the electrode.

(Problems with conventional technology) By the way, in the case of a die-sinking electrical discharge machine, the electrode feed control in the electrode feeding direction needs to improve responsiveness.
Control for swing machining or general numerical control (NC)
Control by equipment, e.g.

The service for displaying the position etc. is NC equipped with this CP.
There was a problem that some U could not do it enough.

(Object of the Invention) In order to solve the above problems, the present invention provides highly responsive control using a dedicated central processing unit with a high-speed interpolator to control the feed axis in the electrode feeding direction. At the same time, shaft control for swing control and control by a general NC device are performed using a low-speed interpolator and another central processing unit, thereby achieving smooth and accurate control of the die-sinking electrical discharge machine. The purpose is to provide a method.

(Summary of the Invention) The interpolation method of the numerical control device of the present invention includes a low-speed interpolator that is started at a constant cycle and a high-speed interpolator that is started at a cycle of 1/n in synchronization with the low-speed interpolator.

The output pulse of the interpolator is the sum of the output pulse of the low-speed interpolator divided into n and the output pulse of the high-speed interpolator.

(Embodiment) Fig. gIJ1 is an explanatory diagram of an embodiment of the interpolation method of a numerical f1 control device according to the present invention, and Fig. 2 is an overall configuration diagram of a numerical control system to which the present invention is applied.・In Figure 2, l
2 is a workpiece, 2 is an electrode, 3 is a V/F converter, 4 is a pulse counter, and 5 is an NC device. Also, in Figure 1,
6 is the main interpolator, 8 is the l/8 interpolator, 9 is the auxiliary interpolator, 1
0 is the rt device.

Here, the discharge state between the work l and the electrode 2 is monitored, and a speed pulse is sent to the pulse counter 4 via the V/F converter 3. On the other hand, the NC device 5 reads the number of input pulses and transmits the speed command VCMD to the control shaft that drives the electrodes. 1. In the interpolation method of the numerical control device of the present invention, a low-speed (main) interpolator 6 that is activated at a fixed period, for example, 16 ms, is provided, and this interpolator 6 controls the oscillating motion around the electrode, Enable jog feed, fast feed, etc. Also, in synchronization with the low-speed interpolator 6,
For example, a high-speed (auxiliary) interpolator 9 is provided that is activated at a period of 1/8 of n, and this interpolator 9 detects when the electrode is fed or when the electrode 2 and the work l are short-circuited. to control the electrode backwards or perform high-speed responses such as jumping.

The main interpolator 6 and the auxiliary interpolator 9 are each composed of separate microprocessors, that is, a main CPU and a sub-CPU.

Next, a case will be described in which an interpolation method having such a low-speed interpolator 6 and a high-speed interpolator 9 is applied to a die-sinking electrical discharge machine.

As mentioned above, in a die-sinking electrical discharge machine that performs oscillating machining, the electrical discharge gap between the workpiece 1 and the 'Fl pole 2 is ff.
Interlocking to feed the electrode while lmL (below).

There are two types of movement: servo interlocking) and oscillating movement, which is a movement that repeats a certain pattern around the servo movement.

Among them, the servo movement controls the discharge gap1, e.g.
In addition to controlling the electrode feed in the normal state, if a short circuit occurs between the workpiece 1 and the electrode 2, this is detected and the electrode 2 is controlled backward, and when the short circuit is restored, the electrode feed control is performed in the normal state. High-speed responsiveness is required, and the calculation cycle must be shortened. However, if the cycle is shortened for this purpose, the NC cannot sufficiently service other processes. So, servo i]! Motion calculations use the sub-CPU of the high-speed interpolator, and by having this CPU perform high-speed calculations at short intervals, for example, every 2 ms, servo 'Bl movement control can be performed quickly and accurately. . On the other hand, swing motion control, jog feed, fast feed, etc. can be performed using the main CPU of the low-speed interpolator 6, for example, with a normal period of 12
Calculations are executed every m5 to ensure smooth swinging without being affected by servo interlocking control! I! It is configured to be able to perform motion, jog feed, V feed, etc.

FIG. 3 is a block diagram showing another embodiment of the numerical control system to which the interpolation method of the multi-f direct control device according to the present invention is applied. In FIG. Yes, positioning information for processing and M,
Accumulated NC command data such as S, T function love/hate, etc., 1
02 is an NC device, which performs tape league from the paper tape 101 to read NC data, and also reads the read N data.
The C data is decoded and, for example, if it is an M, S, T @ function command, it is sent to the machine side via a power board (not shown).

On the other hand, the movement commands, that is, the axis feed command Zc in the Z-axis direction for servo motion control, and the xY-axis commands Xc and Yc for swing motion control, are output to the subsequent pulse distributor, respectively. The NC unit 21102 is a second CPU 102 for swing motion control and other normal NC control according to the control program.
a, a first CPU 102 that exclusively executes arithmetic processing of a feed axis command Zc for servo motion control, a program memory 102b that stores a predetermined control program, a data memory 102c that stores data; operation panel 102d, tape reader/puncher 102e, frequency pulse conversion circuit 102f, input/output capo) 10
2g, current position counter 102h, and display device 102
i and an address/data bus 102 j that connects these
The program memory 102b is comprised of a read-only memory (ROM) and stores an NC program for numerically controlling one machine. On the other hand, in the data memory 102c, in addition to storing the NC data of the paper tape lot (processing 4, 71 data, etc.), the machine program programmed with parameters and user macros is stored in the area PM. 103 is a pulse distributor, which receives movement commands Xc, Y
A known pulse distribution calculation is executed based on c and Zc to generate a distribution pulse Ps of a frequency corresponding to the command speed 5.

104 linearly accelerates the pulse speed of the distribution pulse train Ps when the pulse train is generated;
A known acceleration/deceleration circuit decelerates linearly at the end of J to generate a pulse train Pi, and 105 is an electrode B of a die-sinking electrical discharge machine.
106 is a pulse distributor that generates one feedback pulse EP every time this motor rotates by a predetermined amount; 107 is an error calculation storage section 1 composed of, for example, a reversible counter; circuit 10
For example, this error calculation circuit 11 stores the difference Er between the number of input pulses Pi generated from 4 and the feedback pulse FP.
07a and an error register 107b that stores the error Er. 108 is a digital analog (DA) that generates an analog voltage proportional to the contents of the error register 107b.
) converter, 109 is a speed control circuit. EP is a machining electrode of a die-sinking electrical discharge machine. The electrode EP, which serves as a punch, is supported by a spindle SP, and a machining feed is given in the direction of the arrow by a servo motor 1O5, and a workpiece that becomes a gun is Power supply PS is connected between WK and electrode EP.
Electricity is supplied from the 110 is a gap voltage detection circuit that detects the gap voltage Va from the voltage applied between the electrode EP and the workpiece WK, and txt is the voltage-frequency (
VF) converter, which converts the frequency of analog gap voltage Va.

In the @implanting control system configured in this way, as mentioned above, in the case of misfire 11, the electrode feeding direction feed control to maintain the gap between the electrode EP and the workpiece WK of the die-sinking electrical discharge machine at a constant distance is performed at the first step. Using the CPU 102h of 1, for example, high-speed calculation control is performed every 2 ms per cycle, that is, not only electrode feed control when electrical discharge machining is normal, but also
When the electrode BP and workpiece WK are short-circuited, set the electrode EP to 1.
&flooding control, and when the short-circuit condition is recovered, normal electrode BP feeding control is quickly performed.

On the other hand, the oscillating motion control and jig feeding of the electrode BP.

Fast forwarding and normal NC control use the second cput.

2a is used to perform calculations every 16 ms in one cycle.

Note that the present invention is not limited to the embodiments described above, and various modifications can be made in accordance with the gist of the present invention, and these are not excluded from the scope of the present invention.

(Effects of the present invention) According to the present invention, a low-speed interpolator activated at a constant cycle;
A high-speed interpolator that is activated at a period of 1/n is provided in synchronization with this, and the output of the interpolator is the sum of the output pulse of the low-speed interpolator divided into n and the output pulse of the high-speed interpolator. Since the pulses are used, appropriate control can be assigned to each interpolator, and fine-grained and accurate interpolation can be performed. Furthermore, in a die-sinking electrical discharge machine control method that controls the feed axis and swings the electrode so as to control the discharge gap between the electrode and the workpiece, a dedicated central processing unit is used to control the feed axis. is provided, and the above-mentioned movement control is executed by another central processing unit, so that the feed axis control, which requires high responsiveness, can be controlled using a dedicated CPU. In addition, feed axis control is used for swing control or general NC where high responsiveness is not required.
The device can be controlled smoothly using a separate CPU that meets set conditions. Therefore, the die-sinking electric discharge machine can be controlled smoothly and accurately as a whole.

[BRIEF DESCRIPTION OF THE DRAWINGS] tJIj1 is an explanatory diagram for explaining the interpolation method of the numerical control device according to the present invention, FIG. 2 is a schematic configuration diagram of a numerical control system to which the interpolation method of the present invention is applied, and FIG. 1 is an overall block diagram of a numerical control system for explaining other embodiments. EP...electrode, 6...
Self-speed (main) complement 1■ interpolator, 8...1/8 interpolator. 9...High-speed (auxiliary) interpolator, 10...Adder, 5,
LO2-NC device, 102a...-first CPU, 10
2g...I/O port, 102k...2nd CPU

Claims (3)

[Claims] (1) Providing a low-speed interpolator that is started at a constant cycle and a high-speed interpolator that is started at a 1/n cycle in synchronization with the interpolator,
An interpolation method for a numerical control device, characterized in that the output pulse of the interpolator is the sum of a pulse obtained by dividing the output pulse of the low-speed interpolator into n parts and an output pulse of the high-speed interpolator. (2) An interpolation system for a numerical control device according to claim (1), wherein the low-speed interpolator and the high-speed interpolator are configured by separate microprocessors. (3) In the die-sinking electrical discharge machine, the movement of the electrode in the feeding direction is performed by the high-speed interpolator, and the swinging movement around the electrode is performed by the low-speed interpolator. An interpolation method for a numerical control device according to item (1) or item (2).