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
  • B23H1/00—Electrical discharge machining, i.e. removing metal with a series of rapidly recurring electrical discharges between an electrode and a workpiece in the presence of a fluid dielectric
  • B23H1/02—Electric circuits specially adapted therefor, e.g. power supply, control, preventing short circuits or other abnormal discharges
  • B23H1/022—Electric circuits specially adapted therefor, e.g. power supply, control, preventing short circuits or other abnormal discharges for shaping the discharge pulse train

Definitions

• a discharge is generated between an electrode and a work.
• Discharge heating equipment that processes the work with discharge energy
• FIG.1 is the discharge from the conventional transistor discharge circuit.
• E indicates power supply
• E is power supply
• R 1 is for current limitation
• T 1 is a switching transistor as a switching element.
• W is a work
• P is an electrode
• Power is applied between the workpieces, causing a discharge and processing the workpiece.
• the current limiting resistor R1 generates heat, and the energy loss is large.
• the transistor T1 is turned off.
• the collected energy is the collector of the transistor ⁇ ,
• a second object of the present invention is to provide an electric discharge machining power supply which solves the above-mentioned disadvantages of the prior art, has a small power loss, has a small load applied to a switching element, and can flow a large current. That is.
• a second object of the present invention is to provide a small power loss, a small load applied to the switching element, a large current to flow, and a reverse voltage applied between the electrode and the fork.
• the present invention provides a method of synchronizing the turning on and off of two switching elements, applying a repetitive voltage between the fork and the electrode to generate a discharge.
• a feedback circuit is provided to return the energy stored in the inductance in the discharge circuit to the power supply circuit while applying a low voltage, and the switching element is switched by the surge voltage.
• the present invention provides the above-described feedback circuit for feeding back the energy stored in the inductance in the discharge circuit to the power supply circuit during the application of the voltage, and completes the discharge in the feedback circuit.
• a reverse voltage application circuit for applying a reverse voltage between the work and the electrode via a switching element and a current limiting resistor, which is turned on when the operation is completed, is provided. During this process, a voltage opposite to that at the time of processing was applied.
• the discharge processing power supply of the present invention does not have a current limiting resistor in the circuit, it prevents ripening and reduces power loss. It can be made very small.
• the application of voltage between the electrode and the work is stopped by using the switching element as a power source, it is stored in the floating inductance in the circuit. Energy that was
• a reverse voltage application circuit is added to the circuit that returns the energy stored in the inductance to the power supply circuit, the non- Since a reverse voltage is dynamically applied between the electrode and the work, in the case of discharge using water, the 3 ⁇ 4% reduction action is reduced, electrolytic corrosion is prevented, and the electric discharge is prevented. As a result, the finished surface of the work becomes rougher, and the reverse voltage is applied, so that the disappearance of the discharge becomes faster and the processing speed increases. it can .
• FIG. 1 is a diagram showing a discharge processing power supply by a conventional transistor discharge circuit
• FIG. 2 is a diagram showing a first embodiment of the present invention
• O PI 4 is a diagram showing a second embodiment of the present invention
• FIG. 5 is an operation timing chart of the peripheral embodiment.
• FIG. 2 is a diagram showing a first embodiment of the present invention, wherein 1 is a power supply circuit, E is a power supply, and G is a capacitor provided in the power supply circuit.
• a capacitor having a high response is used as the capacitor
• the power supply circuit ⁇ is a circuit having a small inductance. Is a peak, T 2 and T 3 are transistors as switching elements, D 1 and D 2 are diodes, and constitute a feedback circuit described later.
• L2 represents the floating inductance.
• FIG. 3 (a) is a return pulse applied to the base of the transistor T 2, ⁇ 3. The pulse is applied when the pulse is applied. The transistor T 2, ⁇ 3 periodically turns on and off and returns.
• (B) is a gap voltage VG applied to a gap between the electrode P and the work W, and (c) is a gap current flowing through the gap.
• the figure shows that when a voltage is applied to the cap, it almost discharges around the circumference.
• a pulse is input as shown in (a), and the transistor T
• a gap current IG flows through the gap. That is, the current
• This current is defined as the voltage between terminals of the above power supply circuit as V o.
• transistor transistors T2 and T3 are turned off.
• the output voltage Vo of the power supply circuit 1 is 120 V
• the gap voltage VG is 2 V
• the floating inductance is 1 + L2-0. If the on-time of 5H, transistor 2 and T3 is 1 xs,
• the diode D 1 D 2 and the transistor T are connected so as to reduce the influence of the response delay. 2. It is necessary to use a surge absorption circuit for element protection in T3.
• the gap current IG at the time of discharge and the width of the current are determined by the value of the floating inductance.
• Lee emissions da-click data first class to insert the in the circuit by changing the value of Lee down da-click data down the scan of this formic turbocharger-up current I peak current value of G. Pulse width Can be changed.
• the gap current ⁇ ⁇ G is prevented from suddenly rising to i, so that it rises up smoothly. Therefore, an inductor may be inserted in the circuit for control.
• the switching time of the transistors T 2 and T 3 is fixed. However, after the discharge is detected, the switching time is determined. By turning off the transistor T2, T3, it is possible to always supply a constant energy pulse.
• FIG. 4 is a second embodiment of the present invention, which differs from the first embodiment shown by F1G.2 in that the feedback circuits have diodes D1 and D'2. Resistors R 2, R 3, and switching elements that allow current flow in parallel and opposite to the direction in which the current flows through the die D 1, D 2 Each has a reverse voltage application circuit in which transistor 1: 4, .T5 and diode .D3, D4 are connected in series. It is a point.
• FIG. 5 (a) is applied to the bases of the transistors T 2 and T 3, similarly to the first embodiment shown in FIG. 2 and FIG. A repetitive pulse that conducts the transistors T 2 and T 3, (b> is the gap voltage VG between the power P and the peak W, and (c) is the gap voltage.
• Current IG, (d) is — A repetitive pulse that is applied to the ground of transistor T 4, 5 to turn on the transistors ⁇ 4, ⁇ 5 and to increase the power. .
• the transistors 2 and T 3 are turned on, the gap voltage VG is applied to the gap, a discharge occurs, and the gap current IG is applied to FIG.
• the first embodiment shows that the transistor T2 and T3 turn off, and the gap current IG decreases linearly. And Zhou.
• the transistor T2, T3 is turned on.
• the transistor T4 and T5 of the reverse voltage application circuit see FIG-5 (d)).
• the resistors R2 and R3 are inserted for current control because the current when the reverse voltage is applied is desired to be small. In this way, by applying a reverse voltage between the electrode P and the work W, the arc can be extinguished, and in the discharge processing using water, Positive and negative voltages are applied to an electrolytically eroded work such as a cemented carbide, so that electrolytic erosion can be prevented.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=16854431

Family Applications (1)

Country Status (2)

Cited By (3)

Families Citing this family (4)

Family Cites Families (2)

• 1983
  • 1983-12-02 JP JP22703183A patent/JPS60123218A/ja active Granted
• 1984
  • 1984-11-30 WO PCT/JP1984/000572 patent/WO1985002358A1/ja unknown

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