DE1565299A1 - Switching arrangement for feed control in electrical discharge machining - Google Patents

Description

1565239

Investment and patent management company with restricted inmate in Essen

Dr. Expl,

Stop arrangement for feed control electrical discharge machining

The invention relates to a switching arrangement for feed control in electrical discharge machining by means of several electrodes "moved by a single feed drive" which are each assigned to separate working groups, with the control signal for the feed drive in each case from a dex voltages present at the spark gaps between the electrodes and the workpieces are derived.

With a well-known. Switching arrangement of this type is the control signal in each case from the smallest voltage applied to a spark gap, i.e. the spark gap with the lowest length derived. For this purpose, in the known switching arrangement, the voltages at all spark gaps are only one Auxiliary voltage connected in opposition - which sets the nominal value of the length of all spark gaps uniformly determined. The IT disadvantage of the known switching arrangement is therefore mainly in the Impossibility, at the different spark gaps! -Different ones To set nominal values for their length and then to regulate the feed drive.

cd The invention aims to avoid the mentioned hacli parts

cd and consists in a switching arrangement of the aforementioned

^ Kind in that the voltages at the spark gaps have the target value the length of the same determining auxiliary voltages against are switched and the resulting difference spancn voltages are fed to a control part, the directional control signals in each case depending on the largest negative or positive existing differential voltage © »to the Feed drive emits, the occurrence of a negative

EV 167/62 _ -, _

IT / "'

Differential voltage makes positive differential voltages ineffective. Here, the feed control of dsr is in each case greatest deviation from the target values with the release masters that control signals have priority due to a spark gap that is too short.

The control part of the switching arrangement according to the invention is expediently designed such that both the largest negative as well as the largest positive differential voltage via a rectifier each to a signal converter, the respective differential voltages in output signals with the size of the differential voltage dependent phase position and / or Daiier and transform the output signals changeable impedances in the circuit of the Ilotor of the feed drive, with an output signal on which negative differential voltages are applied Signal converter an atis input signal to that of positive Prevents differential voltages from being applied to the signal converter.

A particularly simple embodiment of the switching arrangement According to the invention, positive differential voltages that occur are tapped only at a single spark gap will. Such an interpretation of the feed control is sufficient for most cases, because at least when it occurs a spark gap that is too short the feed control is already dominated by one of these spark gaps, while it is sufficient that, if the length of all spark gaps is too great any one of these spark gaps dominates the feed control and a reduction in the length of all flank gaps causes.

At. the switching arrangement according to the invention can, of course the voltages at several or all spark gaps also counteract the same auxiliary voltages, whereby these can also have a constant value. Advantageously are, however, in the switching arrangement according to the invention the voltages at the spark gaps different, - preferred-part adjustable emergency voltages SKfc counter-connected ..

909835/0854 - 2 -

* ORIGINAL BATHROOM

Sum preventing an output signal to the van positive Differential voltages applied to the signal converter ^ idle output signal at that of negative differential voltages "beaufscjälajvten signal converter is" at the Switching arrangement according to the invention swecknässigerweise in the rope of the Sreis des Iüotoi "s of the feed drive, the an enlargement of the gap causes the priory development of a TransforEator whose secondary winding with the signal subjected to positive differential voltages unforaer is coupled.

The arrangement of the connections according to the invention is not necessarily self-explanatory the presence of an immediately driving the Yors Club causing electric-IIotors. Instead of this can alsoL ·. others, see B. hydraulic feed drives, ver are applied, the dxircli the Hegel signals are controllable.

In Seicliming there is an example of an axis guide of a switching arrangement nacii of the invention shown schematically, and swar seigt

G. 1 the G-riandsctoaltung for a single one

3? Xffikenspalt and
Own 2 the full circuit for three

Point column. -. .

The Grundselialtimg nacii Eig. 1 has a capacitor 1 which is charged from a voltage source and which is periodically discharged over the swiss line of the electrode 2 and the cavity 3 formed by the workpiece 4. Käs workpiece 4-is via the resistor 5 with the. one FoI 6L · a capacitor β, the other FoI 633 of which is connected to the electrode 2.

The positive pole of the DC voltage source supplying the auxiliary voltage 9 is With one connection of a single

909835/8884

k 156528t

adjustable voltage divider 3 and the pole 6B of the capacitor 6 connected. The negative pole of the general voltage source 9 is connected to the other connection of the adjustable voltage divider Q. The tap of the adjustable ble voltage divider 0 is connected to the pole 6A of the capacitor 6 via the resistor 7.

Are the mean voltage TL ₁ at the spark gap 3 and the auxiliary voltage IL tapped at the voltage divider 6. equal, if you have the specified polarity and if the two resistors 5 and 7 are the same, then the voltage on capacitor 6 and thus between points A and S is Hull. If, however, the mean voltage TL ·, at IPunkenspalt 3 is smaller or larger than the auxiliary voltage XL ₇ tapped at the voltage divider G, then the result at the capacitor 6 is a voltage that is equal to half the difference between the two voltages, and two. Is the EoI 6A negative or positive compared to the lol 6B. Mm & q. The generated differential voltage is used in the "tapped"

The vallätäsadige switching arrangement according to! Ig .. 2; T & eEsrfcÄfc from three vaHstindigen circles of the in. Pig »t

described Jürfe. The den is. W ± g_ .. t mäJs. Jk tezsich points; corresponding & ankt.e of dasei Wss & iM® siad (SLetehriciit.er fOa _s tQb. »IQc vmä. 11 with- dßm deaa.- isusaerdem is: the one in SIg ... 1 with B l £ &% &% (£ i £ emf @ ASL Unlock; recheaa> d e alXen three Erreisen gemeinsaaae SficmM · (üjßgsfefe with SM3SL beiä &m;. gignaluaEggirmfern t2 wxät til this Jm the condensate Arsat Sa ^ & _s spring-6c...

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ORlG ¹ NAL

the signal converter 12 is dispensed with. The two Outputs of the "two transducers 12 and 13 are respectively to a variable impedance each in the form of the thyratron

15 and 16 switched. The llotor 13 of the feed drive is fed by the transformer 17, depending on whether thyratron 15 or thyratron 16 is ignited,

ii

a current flows through the rotor in one direction or the other and thus causes one when the thyratron -15 is ignited Reduction of the dot column and with the thyratron ignited

16 an enlargement of the spark gap. In the healthy one Thyratron 16 from the current part of the circle of the motor is the primary winding of a transformer 14 arranged, whose secondary winding is coupled to the signal converter 12 such that when a voltage occurs the signal converter 12 is blocked at the Selrondary winding.

Controlled rectifiers can also be used as variable impedances or in connection, with rectifiers, transistors, Heiais or similar 'suitable switching elements are used. A transistor would then act as an adjustable resistor operated while a relay is switched on for a shorter or longer time depending on the size of the output signal were. Instead of the DC voltage sources shown as batteries in the drawing, other DC voltage sources with pulsating or constant DC voltage can also be used will.

Claims;

909835/085 A ,, -. ■. \. . ,

ORIGINAL

Claims (1)

1565799 Claims 1. Switching arrangement for feed control in electro-electric machining by means of several electrodes moved by a single feed drive »each of which is assigned to separate working groups» where the control signal for the feed drive each τοη one of the voltages present between the electrodes and the workpieces at the gap gaps is derived »daduroh marked that the voltages at the spark gaps the target value the length of the same existing auxiliary voltages are counteracted and the resulting differential voltages are fed to a control part, the directional control signals each depending on τοη dsr greatest negative or positive gate-handing differential voltage the feed drive delivers »whereby the occurrence of a negative differential voltage makes positive differential voltages ineffective. 2. Switching arrangement according to claim 1 »daduroh characterized in that both the largest negative as well as the largest positive differential voltage across a rectifier each are fed to a signal converter which converts the respective differential voltages into output signals with τοη dar Grease the remote voltage dependent phase position and / or duration and transform the output signals ^ »changeable impedances be fed in the circuit of the motor of the feed drive » wherein an output signal at the signal converter to which negative differential voltages are applied is an output signal applied to the τοη positive differential voltages Signal converter prevented. 3 · Switching arrangement according to claim 1 or 2 »daduroh characterized in that occurring positive differential voltages can only be tapped at a single point gap. SV 167/62 909835/0854 & AD Original Ho / Gu May 12, 1964 4. Switching arrangement according to spoke. 1,2 or 3 «thereby. Kennselohnet, because ·· the voltages at the spark • paltan · different ·, · preferably · divisible Auxiliary voltages are counter-resisted. 5. Switching arrangement according to spoke 2, 3 or 4 »characterized in that an output * signal · · at the signal converter acted upon by positive Hfferensapannungen with an equilateral Aiiagangasignal to de“ acted upon by negative Difierenmepannungen Signaluaforasr in the part of the circuit of the motor of the feed drive ·· ₉ which causes an increase in the “Tonkenspaltes _t dl · primary winding a ·“ transformer, the secondary winding is coupled with the signal converter acted upon by the positive mfferenxepannungen. 9Q9S3 & / Q8 & 4 BATH ORIGINAL Blank page