JPH0724975B2 - Anomaly detection device for electrolytic finishing machine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an abnormality detecting device for an electrolytic finishing machine that finishes a work by electrolytic action.

[Prior Art] Conventionally, as an electric processing machine for electroprocessing a metal, for example, one disclosed in Japanese Patent Publication No. 62-11971 is known.
In this electric processing machine, a plurality of electric storage devices are connected in parallel in a gap between an electrode and a work, which are opposed to each other via a working liquid, and electric charges charged from the electric storage devices are discharged to process the work.

[Problems to be Solved by the Invention] By the way, since this electric processing machine does not include a device for detecting an abnormality in the charging voltage of the battery, the abnormal charging voltage may cause damage to the work and damage to the circuit components. In particular, the electrolytic finishing machine disclosed in Japanese Patent Application No. 62-27616, that is, an electric discharge machined work, is used as an electrode having an electrode surface corresponding to the machined surface of the work (for example, The electrode used during electrical discharge machining (hereinafter, this work and the electrode are referred to as the counter electrode), and when used in an electrolytic finishing machine that finishes machining while supplying pulsed current in a stationary liquid, it takes a long time to achieve a predetermined shape. However, there is a problem that a workpiece that has been subjected to electric discharge machining is instantly turned into a defective product due to an abnormal charging voltage.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to eliminate the above-mentioned inconvenience and to realize an abnormality detecting device for an electrolytic finishing machine, which prevents damage to a work due to an abnormal charging voltage of the electrolytic finishing machine.

[Means for Solving the Problems] In the invention of this application, a work and an electrode are arranged to face each other with a predetermined gap in an electrolytic solution, and a pulse current due to discharge of an electric charge from a capacitor is supplied to the work between the electrodes. In an electrolytic finishing machine for finishing, a shutoff device for shutting off the primary side of a power transformer, a charging switch for turning on / off power supply to a storage device of a current rectified on the secondary side of the power transformer, and the storage device While detecting the charging voltage of, comparing with a reference voltage, an abnormality detection circuit that outputs a signal when the charging voltage is equal to or higher than the reference voltage, and based on the signal of the abnormality detection circuit, activates the breaking device, And a control circuit that holds this state until the power is turned off.

[Operation] According to the abnormality detection circuit of the electrolytic finishing machine according to the present invention, the abnormality detection circuit detects the charging voltage of the battery and compares it with the reference voltage. When the charging voltage becomes equal to or higher than the reference voltage, the control is performed. The circuit activates the circuit breaker provided on the primary side of the power transformer to turn off the voltage supply to the charging switch, power storage device, etc., and hold this off state until the power switch is turned off. It is not charged with a very high charging voltage, and this abnormal voltage is not supplied to the gap between the electrode and the work and each circuit.

Embodiments Embodiments of the present invention will be described in detail and specifically below with reference to the drawings.

1 to 4 show an embodiment of the present invention.
1 to 3, an electrolytic finishing apparatus 1 capable of carrying out the present invention includes an electrode fixing device 3 for fixing an electrode 2, a work fixing device 5 for fixing a work 4, and a rotary motion of a servomotor 6 in a reciprocating motion. A power supply device including a drive conversion unit 7, a DC power supply unit 8 and a charging / discharging unit 9 to be replaced, which generate a pulse current.
10, a control device 14 including a head drive control unit 11, a processing condition control unit 12, an electrolytic solution flow control unit 13, etc., an input device 15 for inputting various data and processing conditions regarding the work 4, an electrolytic solution for filtering the electrolytic solution It is composed of a filtering device 16, a processing tank 17, and the like.

The electrode fixing device 3 has, at its lower end, an electrode 2 which is made of, for example, pure copper or graphite, and which is used when die-cutting or wire-cut electric discharge machining of the work 4 is performed. It is fixed so as to maintain a uniform gap 18 in the three-dimensional direction. The electrode fixing device 3 includes a servo motor 6 that receives a control signal from the head drive controller 11.
Is rotated up and down to set a predetermined gap 18 between the electrode surface 2a and the processed surface 4a.

The work fixing device 5 is a table made of highly insulating granite or ceramics, and the work 4 which is die-cut or wire-cut electric discharge machined is fixed to the upper surface of the work fixing device 5 by a set jig, a screw or the like not shown.

The electrolytic solution filtering device 16 is a dirty pump that supplies the contaminated electrolytic solution in the dirty tank 20 to the pump 21.
22, a clean tank 23 for storing the electrolytic solution filtered by the filter 21, and the electrolytic solution in the clean tank 23 is pumped up and jetted from the jet nozzle 24 arranged so as to be directed to the gap 18 into the gap 18. Clean pump that supplies jet
25, and a liquid temperature adjuster 26 for adjusting the liquid temperature of the electrolytic solution in the clean tank 23.

The electrolytic solution filtering device 16 filters the electrolytic solution containing the electrolytic product generated by processing by the control signal of the control device 14 and supplies the jet stream of the filtered clean electrolytic solution to the gap 18. The electrolytic products and the like in the gap 18 are eliminated. Reference numeral 27 in the drawing is a display device which is arranged above the right side surface of the electrolytic finishing machine 1 and has a plurality of lamps for displaying an abnormality described later.

FIG. 4 is a circuit diagram of the abnormality detecting device according to the present invention, which will be described below.

In the figure, 30 is a power switch, 31 is a power transformer, and 32 to
35 is connected between the power switch 30 and the power transformer 31,
Electromagnetic switch contacts that open and close by energizing coils 36-39, 40-42 are contacts 40a, 40b, 41a, 41b, 42a, 4 respectively.
2b is a thermal relay, 43 is a protector having contacts 43a, 44-1 to 44-3 are diodes for half-wave rectifying a three-phase power supply, 45 is a switching transistor as a charging switch, and 46 is a resistor for limiting current. , 47 is a condenser for supplying a pulse current due to the discharge of electric charge between the electrodes, 48 is a transistor 49, 50, resistors 51-53, condensers 54, 55, a diode
56 is a switching control circuit including 56 and the like, which turns on and off the transistor 45 in response to a control signal from the CPU 57 of the control device 14.

Further, 58 is a zener diode 59, diode 60, thyristor 61, resistors 62 to 66, phototriac 67, an abnormality detection circuit for detecting an abnormality in the charging voltage of the battery 47, 68 is an abnormality having contacts 68a, 68b Voltage detection relays, 69 and 70 are abnormality detection relays, 71 is a relay having contacts 71a and 71b connected in series to the switch 72, and 73 is contacts 73a and 7
Relays having 3b and connected in series with the switch 74, and 75 to 81 are lamps for displaying an abnormality, such as neon tubes. In addition,
In FIG. 4, reference numeral 82 is a power supply terminal of the power supply device 8 and 83 is a ground terminal thereof.

With such a configuration, the abnormality display device according to the present invention can detect the following seven abnormal states.

Abnormality 1 ... Abnormality of the charging voltage of the battery 47 〃… Abnormal operation of the clean pump 25 〃 3… Abnormal operation of the dirty pump 22 〃… Abnormal operation of the liquid temperature regulator 26 〃 5… Abnormal current detection 〃 6… Air pressure Abnormal drop of 7: Detection of lower limit abnormality of clean tank Here, the operation of the circuit in each abnormal state will be described.

(Abnormality 1) For example, when the battery 47 is charged with an abnormal voltage due to an abnormality in the power supply voltage, a failure in the power supply transformer 31, a failure in the diodes 44-1 to 44-3, this voltage V is detected by the abnormality detection circuit 58. It is supplied to the thyristor 61, and when it exceeds the reference voltage Vi set by the diodes 59 and 60, the thyristor 61 is turned on and the phototriac 67 is turned on. The photo triac 67 turns on and the voltage is supplied to the relay 68
When 68 is turned on, energization of the relay 68 is maintained due to conduction of the contact 68a (from OFF to ON), and energization to the coil 36 is cut off due to non-conduction of the contact 68b (from ON to OFF), so that the contact 32 is deenergized. It becomes conductive, and the supply of power to the power transformer 31 is stopped. Further, the lamp 75 is turned on by the supply of the power supply voltage (the voltage between R and T of the three-phase voltage) to the relay 68, indicating that the charging voltage is abnormal.

(Abnormality 2) Clean pump that pumps up the electrolyte in the clean tank 23
When an abnormal load is applied to (the motor of) 25 and an abnormal current flows, the thermal relay 40 operates, the contact 40a switches to the contact 40b side, the power supply to the coil 37 is cut off, and the electromagnetic switch is turned off. Is turned off to stop the power supply to the clean pump 25. In addition, the non-conduction of the contact 40a causes the lamp 76
The power supply voltage is supplied to the LED and lights up to display the operation of the thermal relay 40.

(Abnormalities 3 and 4) The same operation as the abnormality 2 is performed, the operation of the thermal relays 41 and 42 is detected, the lamps 77 and 78 are turned on by the power supply voltage, and each abnormal state is displayed.

(Abnormal 5) When an overcurrent flows through the primary side of the power transformer 31 and the contact 43a of the protector 43 becomes non-conductive, the relay 70 is turned off and the signal is output to the CPU 57, and the lamp 79 is turned on at the power supply voltage. Display the abnormal current status.

(Abnormality 6) For example, when the pressure of the air supplied to the pressure switch (not shown) for detecting the liquid level of the electrolytic solution in the dirty tank 20, the clean tank 23, and the processing tank 17 stops below a predetermined value. The switch 72 becomes non-conductive, the relay 71 operates, the contact 71b becomes conductive, the lamp 80 is supplied with the power supply voltage and lights, and the abnormal state is displayed.

(Abnormality 7) It is used in the same manner as Abnormality 6, and when the electrolytic solution in the clean tank 23 is below the lower limit position, the switch 74 becomes non-conductive, the relay 73 operates, the contact 73b becomes conductive, and the lamp 81 is powered. Turn on the voltage. This is to prevent the jet flow from being stopped from the jet nozzle to the gap 17 when the electrolyte is insufficient.

In FIG. 4, a relay 69 is for outputting the signal to the CPU 57 when the abnormalities 1 to 4 and 6 and 7 occur, and the CPU 57 sends this signal and the relay 70.
The signal is processed by taking the logical sum with the signal.

In this way, the abnormality detection circuit detects abnormalities in the charging voltage of the battery 47.
When it is detected by 58 and becomes higher than the reference voltage, the contact 32 of the electromagnetic switch provided on the primary side of the power transformer 31 is turned off to stop the voltage supply and the power switch 30 detects this state. Since it is held until it is turned off, the capacitor 47 is charged with a voltage equal to or higher than the reference voltage, this voltage is not supplied to the gap, and the work is not damaged in the finishing process of the discharge-processed work. In addition, it is possible to prevent damage to each part of the circuit due to the supply of abnormal voltage, and to use the thyristor used in the abnormality detection circuit 58.
A failure such as 61, that is, an abnormality of the abnormality detection circuit 58 itself can also be detected, and the abnormal charge of the battery 47 can be reliably prevented.

Further, it is possible to detect various abnormal states such as abnormal charging of the electric storage device 47 and operation of the thermal relays 40 to 42, and to concentrate on one outer surface of the electrolytic finishing machine 1 corresponding to each abnormal state. To display on the provided lamps 75-81,
The details of the abnormality can be identified at a glance, and inspections and repairs can be performed easily.
Since ~ 81 are turned on by the power supply voltage, the circuit can be simplified.

In the above embodiment, the case of detecting seven abnormal states has been described, but the number can be set appropriately.

[Effects of the Invention] As described in detail above, since the present invention is configured as described above, the following effects are achieved.

The capacitor is not charged with a voltage higher than the reference voltage, an abnormal current is not supplied between the electrodes, and the work is not damaged during finishing.

It is possible to prevent damage to circuit components due to supply of abnormal voltage.

[Brief description of drawings]

FIG. 1 is a plan view of an electrolytic finishing machine according to the present invention, FIG. 2 is a front view thereof, FIG. 3 is a block diagram thereof, and FIG. 4 is a circuit diagram of essential parts. 1 ... Electrolytic finishing machine, 2 ... Electrode, 4 ... Work,
8 ... Power supply device, 12 ... Control device, 14 ... Electrolyte filtration device, 30 ... Power switch, 31 ... Power transformer, 32-35 ...
… Electromagnetic switch contacts, 36-39 …… Electromagnetic switch coils,
40 to 42 ... Thermal relay, 44-1 to 44-3 ... Diode, 45 ... Switching transistor, 47 ... Condenser, 58 ... Abnormality detection circuit, 57 ... CPU, 75-81 ... Lamp.

Claims (1)

[Claims] 1. An electrolytic finishing machine for finishing a work by arranging a work and an electrode in an electrolytic solution so as to face each other at a predetermined interval and supplying a pulse current due to discharge of an electric charge from a condenser between the electrodes. A shutoff device for shutting off the primary side of the power transformer, a charging switch for turning on / off the power supply to the storage device of the current rectified on the secondary side of the power transformer, and a reference voltage for detecting the charging voltage of the storage device. In comparison with the abnormality detection circuit that outputs a signal when the charging voltage becomes equal to or higher than the reference voltage, based on the signal of the abnormality detection circuit, the cutoff device is operated, and this state is held until the power is turned off. An abnormality detection circuit for an electrolytic finishing machine that includes a control circuit.