JPS58196923A - Power source device for discharge machining - Google Patents

Abstract

PURPOSE:To efficiently consume making electric power for interpole gap discharging machining by returning a part of the electric power to a DC power source at the time of turn-off by a rectifier coupled with a transformer instead of a resistor for consuming electric power. CONSTITUTION:In a power source device for pulse discharge between an electrode 1 and a workpiece to process the workpiece, semiconductor switching elements 9a-9d, a transformer 13, a control device 14, rectifiers 15a, 15b, a choke coil 16 and a condenser form a intermittently operating high-frequency inverter in which input voltage is contrived to be a constant voltage. The inverter is adapted to convert from AC to DC in such a manner as to keep the voltage of a condenser 7 at a reference value. A DC output thus returned to a DC power source is loaded on the DC power source to be a constant voltage, and again becomes a voltage supply source to the interpole gap 3. Thus, making electric power is efficiently consumed for interpole gap discharge machining.

Description

[Detailed Description of the Invention] This invention 1. ．． 1. Pulse discharge Ml between the electrode and the workpiece
This relates to the improvement of a power supply device for electric discharge machining that performs machining in line C.
・In Figure 1, (1) is the electrode, (2) is the workpiece, (3) is the micromachined gap r+ formed by the first lump (hereinafter referred to as the gap), (4) is a first semiconductor switching element such as a bipolar transistor or a field effect transistor; (5) is the semiconductor switching element (4);
A control device that controls L/1 ON and OF k', (
The tied 4-de, (71i, t capacitor, (8) is the equivalent 4c inota'notanos on the line from Sotoshi Dengu to the above pole gap (3), and usually has a low value below IPH. (9) is a second semiconductor switching element such as a bipolar transistor or a field effect type transistor, which forms a series circuit with the resistor (connected in parallel with the transistor (7)). 0M is [Note 8 @ 20
) ON of semiconductor switch element (9), O1! A control device (6) for controlling F is a blood flow IIc system consisting of a transformer, a rectifier, a controller, etc. Figure 2 shows the OFk control (b) to the semiconductor 4-inochinog element glue of L recording movement 2.
Example 10 - Next, the operation will be explained. When the first semiconductor switch and the bordering element (4) are ON L, the insulation between the electrodes (3) is broken and a current flows, but the circuit through which the current flows is shown in Figure 1. As shown, the current increases linearly with time at (V"-VO)t/■, where V is the voltage of the DC power supply υ, and VG is the voltage between the poles. 0) The arc voltage is approximately 20'% 1%L is the line 0) Impairment resistance, (f rises, and when the semiconductor switching element (4) is turned on, after t1 has elapsed, Ip = (Vs -
VOlt +/ Lj (a current flows t), where the semiconductor switching element (4) changes from the ON state to the uFF state. Even assuming that there is, the energy stored in the inductance of the line J) is
Ip'C)) At the 7th moment, the current instantaneously becomes zero, and at the 1st moment the semiconductor switching cable (4jull)
A so-called surge voltage occurs at the ljl terminal [7, current 12 passes through the diode (6) and charges the sensor (7)
, the voltage of Konoano'4F(7) rises.
The li control device αυ is determined by the voltage of the capacitor (7) as shown in Figure 2 or the R10R2 voltage of the Zener Tide.Is it higher or lower than the voltage Vz? The semiconductor switching element (9) is ON/OFF controlled by a comparator (CMF) that determines the voltage, and if the voltage of the capacitor is high, the ON output +Vl is turned on, and if it is low, it is turned OFF.
As shown in FIG. 3(a), as shown in FIG. 3(a), the contact gap (
3), the current il12 shown in Fig. 83 (b) flows, but this is the current i+ at turn 4 (Fig. 8 (C)) and the current il12 at the time of dart off (Fig. 8 (d)). Disassembly>, especially at turn-off Q) Current 12 is similar to 11 between M (3
), some of it contributes to processing, but ultimately most of it is converted into thermal energy of resistor α0.

Conventional electric discharge machining power supplies are configured as described above.In order to control the pulse width of the current between the machining electrodes, the current at the time of turn-off of the semiconductor switching element is stored in a capacitor. , and finally, the resistor is used to make the heat work stable, and the amount of power actually consumed in the first part of electrical discharge machining at the machining gap (3) is calculated from the total power input to the device. In other words, not only is it impossible to expect an improvement in power efficiency in principle, but the power supply device itself, which contains a large amount of semiconductors, generates heat, which causes a decrease in reliability U1.

This invention eliminates the IX point of the conventional one as described above, instead of a resistor that consumes part of the power at turn-off, it is coupled to a transformer. By returning it to the original DC power supply side using a rectifier, there is no unnecessary heat generation caused by resistors, and the input power can be more efficiently consumed in the first process of electric discharge machining between machining electrodes.
The purpose is to provide power supply equipment for 4-hour construction.

An embodiment of the present invention will be described below with reference to the drawings. Fourth
In the figure, j:3 is (9B), (9b), (91, (9
d) l! Both of them are semiconductor switching elements, and the transformer α3 (711 primary side is connected to it; Then, it should be controlled by the control device α◆ so as to repeat ON and OFF at a predetermined frequency.The control device in this case is shown in Fig. 5, using a semiconductor switching element (7) and a field effect transistor (1). 15a), +15b) are tl rectifiers connected to the secondary side of the transformer 0, and are connected to the capacitor αη via the choke coil Ofi.The capacitor Qη is connected to the output of the original free-current power supply!103. 01 is connected to this toe 77 distachonova type constant voltage device (g) which stabilizes the blood flow output.
2 diodes (20a), f20b), (
20c), +20d) j, semiconductor switch blowfish element (9a), +9b), (9c), (9d)
Semiconductor switching elements (9a), (9b), (9
c >, (9d) Eye control device wtO withdrawn and ON, (
J) “)” is controlled by the FBI III device 0.
4JIJ As shown in Figure 5, if the voltage Via of the sensor (7) is lower than the reference voltage kVz determined by the diode, the semiconductor switching element (9a) +19''
+.

(9c), (9d) all () to 'to' + c shi, Vin
Kazena-ta-i 4-1 Te decision, iru group *wLff k
Vz, L' tl sieve it t+ C semiconductor switching element (9a) + (9d) I, - (J N,
19b), (9c) (dan゛l゛, then (9a l,
(9d)? □ (9b), (9c) are connected to N and C, and the semiconductor switching elements are alternately turned ON and OFF, and the transformer (to ). Therefore, when the discharge frequency between the electrodes (3) increases or the peak value of each discharge current is high, the voltage across the connector increases [11. Semiconductor switching element (9a) .

(9b), (9c), t9d) perform repeated switching operations to maintain the capacitor voltage at a constant value.On the secondary side of the transformer (to) is a rectifier (15).
a).

(15b) and remove high-frequency switching noise - (connect choke coil, connect capacitor αη) 1. Convert alternating current that contains a lot of high-frequency switching noise into blood flow (
As described above, the semiconductor switching element (9a),
(9b), (9c), (9d), transformer (to), control equipment! 1 (14).

Rectifier (15a), (15b), fq-ri:]
4 LeQf9. J Notensa αη forms a high-frequency inverter that stabilizes the input voltage and performs intermittent operation, and performs AC/DC conversion to maintain the voltage of the capacitor (7) at a reference value. At this time, the power of the control circuit Q41 is supplied from the capacitor (7), and there is no need to receive a special external supply.In this way, the power is returned to the DC power supply side, and the DC output is returned to the original DC power supply. [
The voltage is regulated by the first voltage regulator connected in a row in a row, and again the voltage is tIIt between the poles (3) =
Juice supply line source. Figure 6 shows the control device t for this constant voltage device.
Q1 performs a so-called pulse width modulation (1'WM) operation in which the pulse width of the f Yonova isona is changed depending on the output voltage. In the above embodiment, a field effect transistor is used as the semiconductor Suinotinog element (9). Below is an example.
f2 uses a normal Hypofusugi transistor.
At the beginning (as shown in Figure 7), a unidirectional switch is connected to the secondary side of the transformer. It may be a half-wave rectification system, and furthermore, the constant current f upper device (to) operates a transistor in a switching operation, a chopper type tgoke Q/j (active.
1) To store the effect of the semiconductor switching element 747 in a capacitor, 0) to make the voltage of the capacitor a constant voltage. At the same time, a type of high-frequency inverter was installed at the input terminal to return power, eliminating the need for a resistor like in conventional devices.
This has the effect of providing a power supply device for electrical discharge machining that has high power efficiency, low self-heat generation, and can be miniaturized.

[Brief explanation of drawings]

Figure 1 is a neo circuit diagram showing the configuration of a conventional electric discharge machining power supply device, Figure 2 is a circuit diagram showing the configuration of the control device for the second semiconductor switching element in the m1 diagram, and Figure 3 is a discharge current waveform. An explanatory diagram, FIG. 4 is a circuit diagram showing the configuration of a power supply device for electric discharge machining according to an embodiment of the present invention, and FIG. 5 is a circuit diagram showing the configuration of a semiconductor switch jig element control device according to FIG. FIG. 6 is a circuit diagram showing the configuration of the control device of the constant voltage device in FIG. 4, and FIG. (1) is an electrode, (2) is an applied object, (3) t
, s-1 degree gap, (4) is the first semiconductor switch element, (6) is the die 4-de, (7) is the capacitor, (9) is the second semiconductor switch element, ＠ is a DC power supply, 11 is a transformer, and (to) is a rectifier. In the drawings, the same reference numerals indicate directions or corresponding parts. Agent Makoto Kuzuno - VL: Yugata (voluntary) 1. 1 'No Showa 71 month [I 4'l"j'l'l!'

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Electrical discharge machining *m equipment: L 1111+1',,, 4 old, It f'l] bolts 1, 7, 1'1 application, d1 °----2- 1, Hitoshi Katayama Part 5, Subject of amendment (1) Bridge of detailed explanation of the invention in the specification. (2) Drawing S Contents of amendment (2) Figures 1 and 15 in the drawing are 10 years old as shown in the attached sheet.
121iI and above 1-

Claims (1)

[Claims] A power supply device for electric discharge machining that supplies an intermittent pulse voltage to the machining gap formed between the electrode and the workpiece via the machining fluid is connected to a DC power supply in series with the power supply, and is connected in series to the power supply. A first semiconductor switching element that repeats operation, and a diode (7
a series circuit consisting of a semiconductor device, an inoanograph element, and a transformer connected in parallel to the capacitor and which performs a switch jig operation when the voltage of the inoanosa is equal to or higher than a reference value; and the transformer. The electric discharge machining device consists of a rectifier circuit connected to the secondary side of the electric discharge machining circuit and a rectifier circuit connected to add the DC power supply voltage.