WO1994006592A1 - Machine d'etincelage par fil-electrode - Google Patents

Machine d'etincelage par fil-electrode Download PDF

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Publication number
WO1994006592A1
WO1994006592A1 PCT/JP1993/001183 JP9301183W WO9406592A1 WO 1994006592 A1 WO1994006592 A1 WO 1994006592A1 JP 9301183 W JP9301183 W JP 9301183W WO 9406592 A1 WO9406592 A1 WO 9406592A1
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WO
WIPO (PCT)
Prior art keywords
discharge
power supply
output
circuit
wire
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/JP1993/001183
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English (en)
Japanese (ja)
Inventor
Syunzo Izumiya
Akihiro Sakurai
Akiyoshi Kawahara
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Fanuc Corp
Original Assignee
Fanuc Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Fanuc Corp filed Critical Fanuc Corp
Publication of WO1994006592A1 publication Critical patent/WO1994006592A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23H—WORKING OF METAL BY THE ACTION OF A HIGH CONCENTRATION OF ELECTRIC CURRENT ON A WORKPIECE USING AN ELECTRODE WHICH TAKES THE PLACE OF A TOOL; SUCH WORKING COMBINED WITH OTHER FORMS OF WORKING OF METAL
    • B23H7/00—Processes or apparatus applicable to both electrical discharge machining and electrochemical machining
    • B23H7/02—Wire-cutting
    • B23H7/04—Apparatus for supplying current to working gap; Electric circuits specially adapted therefor

Definitions

  • the present invention relates to a wire-cut electric discharge machine that discharges between a workpiece and a wire electrode and processes the workpiece with its energy.
  • a wire-cut electric discharge machine which supplies a pulsed current from the power supply circuit to the wire electrode via electrons, monitors the occurrence of concentrated discharge and the state of power supply by these feeders.
  • wire-cut electric discharge machining maintaining a normal discharge between a workpiece and a wire electrode (hereinafter referred to as a wire) is important for performing high-precision machining.
  • a wire is too close to the workpiece and the discharge gap is short-circuited, or machining debris or free carbon in the coolant that fills the gap between the workpiece and the wire Due to uneven distribution, abnormal discharge phenomena (concentrated discharge) may occur, such as discharge points being concentrated in one place.
  • pulsed power is supplied to the wire from the power supply for discharge via the power supply, which is an electrode. If the power supply via the power supply is not performed normally, the normal discharge will not be maintained. At this time, since the wire comes in contact with a part of the power supply fixed in a fixed position and moves, the power supply may be worn to cause poor contact with the wire. Most of the power feeds are usually separated by two in the direction of wire travel. Since it is installed, even if the wire is in poor contact with one of the power supply terminals, the discharge will not be stopped by the power supply from the other power supply terminal. However, when the power is supplied by only one of the power supply electrodes, the voltage distribution in the wire changes, and a uniform discharge state cannot be maintained over the entire area of the machined surface.
  • the conventional abnormal discharge detection device was composed of a circuit as shown in the block diagram of FIG. That is, the potential difference between the workpiece 1 and one of the two feeders 2a and 2b (2a) is measured by the voltage measuring device 3a, and the workpiece 1 and the other feeder 2b And the potential difference between them is measured by the voltage measuring device 3b during the discharge period (that is, while the switch circuit 5 that converts the machining DC power supply 6 into pulsed power is on). The measured values are output to the controller 4 side.
  • the control device 4 performs processing such as discriminating whether or not the input values from the two voltage measuring devices 3a and 3b are uniformly dispersed, and makes the current discharge state normal. Has been determined.
  • Reference numeral 7 denotes a wire, which comes into contact with both of the power supply terminals 2a and 2b, and travels from the upper side to the lower side in the figure.
  • the centralized discharge is monitored using the detected values, while the power supply is simultaneously used with these detected values. and this called for monitoring of the power supply failure also was enough to be a force 3 ⁇ 4
  • An object of the present invention is to detect an abnormal discharge between a workpiece and a wire, to detect a contact failure between a wire and a power supply, and to indicate that these have been detected.
  • An object of the present invention is to provide a jet electric discharge machine.
  • one embodiment of the present invention provides a wire electric discharge machine that supplies a pulsed current from a power supply circuit for discharge to a wire electrode via two power supply terminals.
  • First and second discharge current detecting means for detecting a temporal change in a discharge current flowing through a power supply path to a power supply; a wire at the discharge time using the first and second discharge current detecting means;
  • Discharge position calculating means for calculating a value related to the discharge position on the electrode; a plurality of comparing means having different reference values for inputting the output of the discharge position calculating means;
  • a plurality of storage means for storing the outputs of the plurality of comparison means, respectively; the data stored in the storage means are read out at every predetermined number of discharges, and the data of each storage means read out in the same manner as the previous time are read out.
  • Discharge state determination means for determining whether or not a change or variation greater than a predetermined value is found in the data held in each storage means in comparison with the first and second discharge current detectors.
  • Power supply state determining means for determining whether the difference between the two outputs is within a predetermined range; and inputting and displaying the output of the power supply state determining means and the output of the discharge state determining means. Display means.
  • another aspect of the present invention relates to a wire electric discharge machine for supplying a pulsed current from a discharge power supply circuit to a wire electrode via two power supply terminals.
  • a first and a second discharge current detector for detecting a temporal change of a discharge current flowing respectively; based on an output of an adder and a subtractor to which outputs of the first and second discharge current detectors are inputted; The discharge position at which the value related to the discharge position on the wire electrode at the discharge time is calculated, and the count value corresponding to the calculated value is counted up from the plurality of count values.
  • Sorting circuit A power supply state detection circuit that receives the output of the subtractor in the discharge position sorting circuit, determines whether the output value of the subtracter is out of a predetermined range, and outputs a determination signal.
  • the above-mentioned discharge position every predetermined number of discharges And read out the count down bets value held in the mosquito window down evening divided circuits, compared to mosquito window down bets value of each mosquito window pointer was read out as before in
  • the abnormal discharge detection unit that determines whether the count value held at each count has a change or variation greater than a predetermined value, and a determination from the power supply state detection circuit.
  • An operation means comprising a power supply failure detecting unit for accepting another signal; and an indication from the output from the abnormal discharge detection unit of the operation means that a concentrated discharge is occurring, and from the power supply failure detection unit
  • a display means is provided for displaying from the output of the power supply that there is wear or contact failure in the power supply.
  • the change over time of the discharge current to the two power supply terminals of the wire electric discharge machine is detected by the detection means, and therefore, based on the output from these detection means, It can calculate whether or not a concentrated discharge has occurred, and on the other hand, can determine whether or not a power supply failure has occurred with any of the power supply terminals.
  • FIG. 1 is a diagram schematically showing a means for detecting abnormal discharge and power supply failure in an electric discharge machine according to the present invention.
  • Fig. 2 is a circuit diagram of the means for detecting abnormal discharge and power supply failure shown in Fig. 1.
  • FIG. 3 is a diagram schematically showing means for detecting abnormal discharge and power supply failure in an electric discharge machine belonging to the prior art
  • FIG. 4 is a circuit diagram for explaining the processing of FIG.
  • Fig. 1 shows a schematic diagram of the wire-cut electric discharge machine 10 in a block diagram, and has the same components as in Fig. 3 shown above. Are given the same numbers.
  • the electric discharge machine 10 includes a current detector 12a, 12b for detecting a temporal change of a discharge current flowing through each of the two feeders 2a, 2b, that is, a current differential value. It is equipped with.
  • the detection values measured by the current detectors 12a and 12b are sent to a discharge position sorting circuit 14 and a power supply state detection circuit 13 to be described later, respectively, and processed.
  • Their and output from the sheet conductive state detection circuit 1 3 and the discharge position sorting circuit 1 4 is sent to the control unit 4, concentrated discharge occurs in here ⁇ : poor feeding of whether the Is al the feed element are It is determined whether or not an error has occurred.
  • the control device 4 is connected to a manual data input device and a display for notifying power supply failure or abnormal discharge.
  • FIG. 2 An example of the power supply state detection circuit 13 and the discharge position classification circuit 14 is shown in FIG.
  • reference numeral 11 denotes a discharge current measurement circuit
  • reference numeral 13 denotes a power supply state detection circuit
  • reference numeral 14 denotes a discharge position sorting circuit
  • reference numeral 4 denotes a block surrounded by a chain line.
  • This is a control circuit including arithmetic means 25.
  • coils are provided as current detectors 12a and 12b for the power supply paths to the upper power supply 2a and the lower power supply 2b, respectively. ing. Then, the temporal change (differential value with time) of the current flowing to the feeders 2a and 2b is calculated as the voltage el and e2 by these coils. Detected and sent to the discharge position sorting circuit 14 side.
  • the discharge position sorting circuit 14 receiving the data corresponding to the differential value of the discharge current flowing to the power supply terminals 2a and 2b, as described later in detail, shows that the discharge phenomenon is caused by the wire and the workpiece.
  • the dolphin take place in any region of the gap between the goods, the discharge charging time (the time between being turned Ri by the switch circuit 5 in FIG. 1;. the so called n) detected for each), the The occurrence is recorded in counters 21a, 21b, ... 21n corresponding to each area.
  • the data stored in the counter 21 a, 2 lb, -21 ⁇ is read out by the control device 4 at predetermined time intervals, analyzed, and stored in a specific area. It is determined whether or not only concentrated discharge is occurring (that is, concentrated discharge is occurring).
  • the gap voltage VG between the wire and the workpiece 1 and the voltage of the machining power source 6 are VC.
  • the resistance of the conductor from machining power supply 6 to branch point P And the floating inductance is R0, L0; the resistance of the conductor from the junction P to the upper feeder 2a and the floating inductance is R1, L1; the lower feeder 2 from the junction P
  • the resistance of the conductor up to b and the floating inductance are R2, L2; the resistance of the wire from the upper feeder 2a to the discharge position Q and the floating inductance are Ru, Lu;
  • Rd and Ld be the resistance of the wire and the floating inductance from the power supply 2b to the discharge position Q above.
  • the current flowing through the upper power supply 2a is ia
  • the current flowing through the lower power supply 2b is ib
  • the discharge current is i (two ia + ib).
  • V c i R 0 + L 0 ⁇ + a (R 1 + r 1)
  • the following equation is derived from the closed circuit of the machining power supply 6, the workpiece 1, the wire 7, the lower feeder 2b, and the machining power supply 6.
  • V c i R 0 + L 0 + i b (R 2 + r 2
  • the discharge position Q measures and d d d t
  • the current detectors 12a and 12b of the discharge current measurement circuit 11 use the current detectors 12a and 12b to differentiate the discharge currents ia and ib during the same discharge period (current differential value). Are measured, and these measured values (el, e 2) are sent to the differential amplifier 15 and the adder 16. The outputs from the differential amplifier 15 and the adder 16 correspond to the numerator and denominator on the left side of the above equation (10), respectively.
  • the outputs from the differential amplifier 15 and the adder 16 are sent to the dividing circuit 17, where the left side of the equation (10) is calculated, and the right side of the equation (10) is calculated.
  • the value corresponding to L u—L d of It is output to the sample hold circuit 18 ⁇ Therefore, the output from the sample hold circuit 18 is information on the discharge position Q. That is, the differential amplifier 15, the adder 16 and the dividing circuit 17 constitute a discharge position calculating means.
  • the current detector 12b detects the discharge current
  • the rising edge thereof triggers the timer 19.
  • the sample hold circuit 18 holds the output from the divider 17 at the start of the discharge for a predetermined period of time to generate a plurality of comparators. Evening 20a, 2Ob, ⁇ , output to 20n side.
  • the outputs from the sample hold circuit 18 are compared with the comparison voltages Va, Vb,..., Vn at different levels according to the above-mentioned comparators 20a, 20b, ..., 20 ⁇ . Are compared.
  • the output sides of these comparators 20a, 20b, ..., 20n are connected to the input sides of the counters 21a, 21b, ..., 21 ⁇ , respectively, in one-to-one correspondence. I have. If the input to each comparator is higher (or lower) than the comparison voltage, a high-level signal is output to the counter corresponding to the comparator. Count up those powers. That is, the outputs of the comparators 20a, 20b,..., 20 ⁇ as the comparison means are stored in the input terminals 21a, 21b, ..., 21 ⁇ . .
  • the control device 4 intervenes during each period of 21 a, 2 1 b,..., 2
  • the values stored in In are read via the I / O circuit I ZO, and the values counted by each counter and the counters at the time of the previous reading are read. By comparing the count value with the count value, whether the count value at each count or the variation of the count value between the counts has changed more than a predetermined value. Is determined by the calculating means 25 provided in the control device 4.
  • the calculation means 25 calculates the counters 21a and 21b between the count value of each count previously captured and the count value of each count captured this time.
  • the power supply state detection circuit 13 for determining whether or not the power supply failure has occurred in the power supply is performed by each of the power supply 2a, 2
  • the temporal change of each discharge current to b is obtained from the output of the differential amplifier 15 in the discharge position sorting circuit 14 shown above.
  • the discharge position sorting circuit 14 determines whether or not the difference between the current differential values of the power feeders 2a and 2b output from the differential amplifier 15 is within a predetermined range. Identify whether a power supply failure has occurred in any of the power supply terminals.
  • the circuit itself is similar to the one described in Japanese Patent Application Laid-Open No. Sho.
  • the output (el-e 2) of the differential amplifier 15 in the discharge position sorting circuit 14 in FIG. 2 is sent to the two comparators 22 a and 22 b in the power supply state detection circuit 13.
  • Can be One of the comparators 22a compares the input value (output from the differential amplifier 15) with the comparison voltage VI, and outputs a high-level signal only when the input value is higher than the comparison voltage VI. Output and transmit to one input terminal of OR gate 23.
  • the other comparator 22b compares the input value with a comparison voltage V2 of a different level from the comparison voltage VI, and Only when the value is lower than the comparison voltage V 2 is a single-level signal output, but this signal is converted to a high level by an inverting circuit in the middle and transmitted to the other input terminal of the output 23.
  • the high level output from the OR circuit 23 is transmitted to the control device 4 via the input / output circuit 1 0, and is sent to the manual data input device 24 by the operation device 25 of the control device 4. This is indicated on the attached display.
  • the control device 4 is a normal numerical control device (NC device), a central processing unit (CPU), a read-only memory (ROM) containing a system program, etc., and a machining program for performing electric discharge machining. It has a write / read memory (RAM) and an input / output circuit (I / O) containing the data. Further, a manual data input device 24 for inputting and setting parameter overnight value data to the control device 4 is connected to the control device 4. As described above, the data manual input device 24 is provided with a display.

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)

Abstract

Une machine d'étincelage par fil-électrode fournit un courant pulsé allant d'un circuit d'alimentation électrique à un fil-électrocde par l'intermédiaire des deux conducteurs d'alimentation. On détecte les changements dans les courants de décharge passant par ces deux conducteurs en fonction du temps (donc de la valeur de différentiation des courants) et on utilise les résultats de cette détection pour obtenir des données relatives à la situation de décharge et donc déterminer un éventuel changement de cette situation dans le temps. On surveille par conséquent une éventuelle décharge concentrée. On détermine aussi la différence de courant entre les deux conducteurs pour voir si elle correspond à une fourchette prédéterminée et surveiller toute usure ou contact déficient concernant ces conducteurs.
PCT/JP1993/001183 1992-09-11 1993-08-24 Machine d'etincelage par fil-electrode Ceased WO1994006592A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP26796292A JPH0691433A (ja) 1992-09-11 1992-09-11 ワイヤカット放電加工機
JP4/267962 1992-09-11

Publications (1)

Publication Number Publication Date
WO1994006592A1 true WO1994006592A1 (fr) 1994-03-31

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Application Number Title Priority Date Filing Date
PCT/JP1993/001183 Ceased WO1994006592A1 (fr) 1992-09-11 1993-08-24 Machine d'etincelage par fil-electrode

Country Status (2)

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JP (1) JPH0691433A (fr)
WO (1) WO1994006592A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5500500A (en) * 1994-03-17 1996-03-19 Toyota Jidosha Kabushiki Kaisha Process and apparatus for electric discharge position detection
CN106944687A (zh) * 2016-01-07 2017-07-14 发那科株式会社 具有供电线的恶化检测功能的线放电加工机

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63185520A (ja) * 1987-01-23 1988-08-01 Kazuo Muto 放電加工制御装置
JPS6411726A (en) * 1987-07-07 1989-01-17 Fanuc Ltd Wire breaking detecting device
JPH01121127A (ja) * 1987-10-31 1989-05-12 Fanuc Ltd ワイヤ放電加工機における放電位置検出装置

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63185520A (ja) * 1987-01-23 1988-08-01 Kazuo Muto 放電加工制御装置
JPS6411726A (en) * 1987-07-07 1989-01-17 Fanuc Ltd Wire breaking detecting device
JPH01121127A (ja) * 1987-10-31 1989-05-12 Fanuc Ltd ワイヤ放電加工機における放電位置検出装置

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5500500A (en) * 1994-03-17 1996-03-19 Toyota Jidosha Kabushiki Kaisha Process and apparatus for electric discharge position detection
CN106944687A (zh) * 2016-01-07 2017-07-14 发那科株式会社 具有供电线的恶化检测功能的线放电加工机
KR20170082988A (ko) * 2016-01-07 2017-07-17 화낙 코퍼레이션 급전선의 열화 검출 기능을 갖는 와이어 방전 가공기
CN106944687B (zh) * 2016-01-07 2019-03-01 发那科株式会社 具有供电线的恶化检测功能的线放电加工机
KR101970391B1 (ko) 2016-01-07 2019-04-18 화낙 코퍼레이션 급전선의 열화 검출 기능을 갖는 와이어 방전 가공기

Also Published As

Publication number Publication date
JPH0691433A (ja) 1994-04-05

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