JPH0620460U - Metal surface treatment equipment - Google Patents

Abstract

(57) [Abstract] [Purpose] Even if an overcurrent flows between a pair of electrodes for treating a metal surface and the power supply is turned off, the power supply is automatically returned to the on state. [Structure] A power supply for applying a voltage between the positive terminal 11 and the negative terminal 12 is mainly composed of a transformer 3, and this power supply is turned on and off by a power supply thyristor 4.
The power switch unit 31 detects that an overcurrent flows between the positive terminal 11 and the negative terminal 12, and switches off the power supply thyristor 4. The power supply restoration setting unit 41 functions to periodically set the power supply thyristor 4 to ON. Therefore, even if an overcurrent flows between the positive terminal 11 and the negative terminal 12 and the power source is turned off, the power source is automatically returned to the on state.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an apparatus for treating a metal surface for cleaning the metal surface or plating the metal surface.

[0002]

[Prior art]

 As is well known, in this type of processing apparatus, a voltage is applied between a pair of electrodes, one electrode is connected to a metal, the other electrode is covered with asbestos, and this asbestos is impregnated with an electrolytic solution. By contacting the asbestos with the metal surface, it is possible to clean weld marks on the metal surface or to form a plating on the metal surface. That is, an electric current is passed between the metal surface and the electrolytic solution, and the metal surface is treated by the chemical reaction generated at this time.

FIG. 4 shows the appearance of the above-mentioned conventional processing apparatus. As shown in this figure, two extension cords 102 and 103 are derived from the apparatus main body 101. A clip 104, which is a pair of electrodes, and a holder 105 are connected to the extension cords 102 and 103, respectively. The clip 104 is connected to the metal plate 106, and the holder 105 is covered with asbestos 107. The asbestos 107 is impregnated with the electrolytic solution. Here, with the voltage applied between the clip 104 and the holder 105, the surface of the metal plate 106 is treated by wiping the surface of the metal plate 106 with this asbestos 107.

[0004]

[Problems to be solved by the device]

 By the way, when the metal surface is treated, the clip 104, which is a pair of electrodes, and the holder 105 may be short-circuited and an overcurrent may flow. In this case, the protection circuit built in the apparatus main body 101 operates to interrupt the flow of current, so that it is necessary to press the reset button 108 for canceling the interruption of current when continuing the process.

However, for example, when processing the surface of a large metal plate, the two extension cords 102 and 103 are pulled around to perform the work. However, if the clip 104 and the holder 105 are short-circuited during this work. Each time, the reset button 108 has to be pressed back to the place where the apparatus main body 101 is installed, which causes a problem that work efficiency deteriorates.

Therefore, an object of the present invention is to obtain a metal surface treatment apparatus which does not require the reset button to be pressed down even if an overcurrent flows between a pair of electrodes.

[0007]

[Means for Solving the Problems]

 In order to solve the above problems, in the present invention, a switch means for turning on and off a power supply for applying a voltage between the electrodes and an overcurrent flowing between the electrodes are detected to detect the power supply. And a setting means for periodically setting the power supply to be turned on through the switch means.

[0008]

[Action]

 According to this invention, when the detection means detects that an overcurrent has flowed between the electrodes, the power supply is turned off through the switch means. This prevents overcurrent from flowing. Further, the setting means periodically sets the power source to be turned on through the switch means. Therefore, even if the power supply is turned off due to an overcurrent, the power supply is turned on by the setting means after that.

[0009]

【Example】

 An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a circuit diagram showing an embodiment of a processing device according to the present invention. In the figure, the power plug 1 is connected to a commercial AC power source, and power is supplied from here. The four switches 2-1 to 2-4 are interlocked with each other, and when turned on, connect either the terminal A and the terminal B or the terminal C and the terminal B, respectively.

When the switches 2-1 to 2-4 are turned on and the terminals A and B are connected to each other, one terminal of the primary side coil in the power transformer 3 turns on the switch 2-1. Via the power supply thyristor 4 and the fuse 5. The other terminal of the primary coil is connected to the commercial power supply via the power supply thyristor 4 and the fuse 5. One terminal of the secondary coil of the power transformer 3 is connected to the positive terminal 11 via the ammeter 6, the rectifier circuit 7, the switch 2-2 and the two resistors 8a and 8b, and the secondary coil is connected. The other terminal is connected to the negative terminal 12 via the rectifier circuit 7 and the switch 2-3.

At this time, since the rectifier circuit 7 is interposed between the secondary coil of the power transformer 3 and each of the two switches 2-2 and 2-3, between the positive terminal 11 and the negative terminal 12, A DC voltage will be applied.

Here, as shown in FIG. 2, the positive terminal 11 is connected to the clip 14 via the extension cord 13, and the negative terminal 12 is connected to the holder 16 via the extension cord 15. The clip 14 is connected to a metal plate 17 to be treated, and the holder 16 is covered with asbestos 18 impregnated with an electrolytic solution. When this asbestos 18 is rubbed on the surface of the metal plate 17, a direct current flows between the surface of the metal plate 17 and the electrolytic solution of the asbestos 18, and the chemical reaction at this time cleans the welding marks on the metal surface.

In this way, when a DC voltage is applied between the positive terminal 11 and the negative terminal 12 to clean the metal surface, the metal surface has a glossy mirror finish.

When the switches 2-1 to 2-4 are turned on and the terminals C and B are connected to each other, the primary coil of the power transformer 3 is connected to the commercial power source. The secondary coil is directly connected to the positive terminal 11 and the negative terminal 12 without the rectifier circuit 7. Therefore, an AC voltage is applied between the positive terminal 11 and the negative terminal 12. At this time, an AC voltage is also applied between the clip 14 and the holder 16 shown in FIG. 2, and an AC current flows between the surface of the metal plate 17 and the electrolytic solution of the asbestos 18 to clean the welding marks on the metal surface.

When an AC voltage is applied between the positive terminal 11 and the negative terminal 12 in this manner, the metal surface has a matte finish.

The varistor 20 connected in parallel to the power supply thyristor 4 is for protecting the thyristor 4. The pilot lamp 21 inserted in parallel with the primary coil of the power transformer 3 is an indicator lamp indicating whether or not the power supply from the commercial power source is received. Furthermore, the voltmeter 22 inserted in parallel with the secondary coil of the power transformer 3 displays the voltage of the secondary coil. Based on this voltage and the current displayed on the ammeter 6, , It is possible to know the electric power consumed for processing the metal surface.

On the other hand, the holder 16 shown in FIG. 2 is provided with the remote switch 23 shown in FIG. 1, and this remote switch 23 is guided to the voltage detection section 24 via an extension cord and connected thereto. There is.

The voltage detection unit 24 is supplied with the AC voltage from the sub-transformer 25, rectifies the AC voltage by the first rectifier circuit 26, and obtains the DC voltage.

Now, when the remote switch 23 is turned on, a current flows through a route of the first rectifier circuit 26 → resistor 27 → zener diode 30 → parallel circuit of the resistor 28 and the light emitting element of the photocoupler 29 → remote switch 23. At this time, the light emitting element of the photocoupler 29 emits light, and the light receiving element of this photocoupler 29 is turned on.

The light receiving element of the photocoupler 29 is incorporated in the power switch unit 31. In the power switch unit 31, the light receiving element of the photocoupler 29 is inserted in the path from the electrode T of the power supply thyristor 4 to the gate G. In this path, the volume 32, the resistors 33a, 33b, 33c, 33d, A distributed constant circuit including the capacitors 34a, 34b, 34c and the trigger diode 35 is formed. Here, if the resistance value is changed by manipulating the volume 32, the phase of the AC voltage applied to the gate G of the power supply thyristor 4 changes, which changes the voltage applied to the power supply transformer 3. It Therefore, the volume 32 can be adjusted to change the voltage applied to the power supply transformer 3 and consequently the voltage between the clip 14 and the holder 16.

In the voltage detection unit 24, when the switch 2-4 is turned on and the terminals A and B are connected, the first rectifier circuit 26 → resistor 36 → switch 2-4 → light emission. A current flows to the diode 37, and the light emitting diode 37 emits light, indicating that a direct current voltage is applied between the clip 14 and the holder 16. On the other hand, when the terminal C and the terminal B of the switch 2-4 are connected, a current flows through the first rectifier circuit 26 → the resistor 36 → the switch 2-4 → the light emitting diode 38, and the light emitting diode 38 It emits light to indicate that an AC voltage is applied between the clip 14 and the holder 16.

On the other hand, the power supply restoration setting unit 41 includes a monostable multivibration radar 42 composed of an integrated circuit and peripheral circuits and a switching transistor 43. Clock pulses are transmitted from the monostable multivibration radar 42 to the switching transistor 43. It is being output. This clock pulse has a period of 5 (sec), for example, as shown in FIG. 3, and the switching transistor 43 is turned on every time in response to this clock pulse.

Each time the switching transistor 43 is turned on, a path of the first rectifying circuit 26 → resistor 45 → light emitting diode 46 → switching transistor 43 → ground is formed, and the light emitting diode 46 emits light intermittently. To do. At the same time, a path of the first rectifier circuit 26 → the parallel circuit of the buzzer 47 and the diode 48 → the switching transistor 43 → the ground is formed, and the buzzer 47 intermittently emits sound.

The voltage detector 24 is provided with the second rectifier circuit 51. The rectifier circuit 51 inputs the voltage between both terminals of the resistors 8a and 8b inserted in the line on the positive terminal 11 side, rectifies this voltage, and outputs a DC voltage to the resistor 52. The voltage of the movable contact of the resistor 52 is applied to the gate of the thyristor 53.

Here, when the metal surface is treated smoothly, and if no overcurrent flows between the clip 14 and the holder 16, the voltage output from the second rectifier circuit 51 is at a low level. Therefore, the voltage applied to the thyristor 53 from the movable contact of the resistor 52 is also extremely low, and therefore the thyristor 53 maintains the off state.

In this state, when the clip 14 and the holder 16 are short-circuited and an overcurrent flows, the voltage output from the second rectifier circuit 51 rises, and the thyristor 53 moves from the movable contact of the resistor 52. The voltage applied to the thyristor 53 rises and the thyristor 53 turns on.

At this time, a current path of the first rectifier circuit 26 → resistor 27 → diode 54 → zener diode 55 → thyristor 53 → ground is formed, and the current output from the first rectifier circuit 26 is It flows to the earth through the route. Therefore, no current flows in the path from the first rectifier circuit 26 to the remote switch 23 via the light emitting element of the photocoupler 29, whereby the light emitting element of the photocoupler 29 does not emit light and the photocoupler 29 in the power switch section 31 is stopped. The light receiving element of turns off.

In the power supply switch unit 31, since the light receiving element of the photocoupler 29 is turned off, the path from the electrode T of the power supply thyristor 4 to the gate G is cut off, and the power supply thyristor 4 is turned off. As a result, no voltage is applied to the power transformer 3, and the voltage output between the clip 14 and the holder 16 becomes zero.

At this time, a current also flows through the path of the first rectifier circuit 26 → the resistor 45 → the light emitting diode 46 → the Zener diode 55 → the thyristor 53 → the earth, and the light emitting diode 46 continuously emits light. Further, a current also flows through a path of the first rectifier circuit 26 → a parallel circuit of the buzzer 47 and the diode 48 → the Zener diode 55 → the thyristor 53 → ground, and the buzzer 47 continuously sounds. As a result, a short circuit between the clip 14 and the holder 16 is notified.

That is, regardless of whether the output between the clip 14 and the holder 16 is an AC voltage or a DC voltage, when an overcurrent flows between the clip 14 and the holder 16, this overcurrent is detected by the voltage detection unit 24. Then, the light receiving element of the photocoupler 29 is turned off, and the voltage output between the clip 14 and the holder 16 is interrupted. At the same time, the light emitting diode 46 continuously emits light, and the buzzer 47 continuously emits sound to notify of a short circuit between the clip 14 and the holder 16, which makes it possible to detect that the treatment of the metal surface is interrupted.

When the short circuit between the clip 14 and the holder 16 is instantaneous, the capacitor 56 connected in parallel with the resistor 52 absorbs the pulse-shaped voltage output from the second rectifier circuit 51. Therefore, the thyristor 53 does not turn on only by momentarily short-circuiting the clip 14 and the holder 16.

After that, when the clock pulse is output from the monostable multivibration radar 42 to the switching transistor 43 in the power restoration setting unit 41, the switching transistor 43 is turned on. At this time, the thyristor 53 in the voltage detecting section 24 is grounded at its anode side through the Zener diode 55 and the switching transistor 43, thereby returning from ON to OFF.

As a result, the current path from the Zener diode 55 to the ground via the thyristor 53 is cut off, and the current output from the first rectifier circuit 26 flows through the original path. That is, the first rectifier circuit 26 → resistor 27 → zener diode 30 → parallel circuit of the resistor 28 and the light emitting element of the photocoupler 29 → a current flows through the path of the remote switch 23, and the light emitting element of the photocoupler 29 emits light, The light receiving element is turned on, the power supply thyristor 4 is turned on, a voltage is applied between the clip 14 and the holder 16, and the treatment of the metal surface can be restarted.

Further, in synchronization with the clock pulse output from the monostable multivibration radar 42, the DC current output from the first rectifier circuit 26 also flows to the light emitting diode 46 and the buzzer 47, which causes The light emitting diode 46 emits light intermittently, and the buzzer 47 emits sound intermittently.

As described above, in the above-described embodiment, when an overcurrent flows between the clip 14 and the holder 16, the power supply thyristor 4 is turned off in response to this, and the power supply to the power transformer 3 is stopped. However, when a clock pulse is output from the monostable multi-vibration radar 42 after this, the power supply thyristor 4 automatically returns to the on state, so a short circuit occurs between the clip 14 and the holder 16 during the processing of the metal surface. However, unlike the conventional device, it is not necessary to press the reset button, and the work can proceed efficiently.

In the above embodiment, a thyristor or a photocoupler is inserted in each current path to interrupt or connect these current paths. However, the present invention is not limited to this, and a plurality of relays may be used. May be inserted in each current path. Of course, in this case, the circuit configuration is for switching each relay on and off. The oscillation source of the clock pulse is not limited to the monostable multi-brader, but various oscillation circuits can be applied. Further, it is also possible to start the clocking for a fixed period only when the power supply for applying the voltage between the clip and the holder is cut off, and then restart this power supply after the fixed period.

In short, the power supply for applying the voltage between the clip and the holder should be reset periodically so that even if an overcurrent flows between the clip and the holder and this power is cut off, the power is automatically restored. Any configuration may be used.

Further, here, although an apparatus for cleaning welding traces on a metal surface is illustrated, the positive and negative of each voltage of the clip and the holder are reversed, and the kind of the electrolytic solution is simply changed to change the metal surface. The present invention can be applied to such an apparatus as well, since plating can be applied to the device.

[0040]

【effect】

 As described above, according to the present invention, even when the power is turned off due to the overcurrent flowing between the pair of electrodes in which one is connected to the metal and the other is immersed in the electrolyte, the power is turned on. Since it automatically returns, the work can proceed efficiently.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of an apparatus for treating a metal surface according to the present invention.

FIG. 2 is a diagram showing fixtures connected to the apparatus shown in FIG.

FIG. 3 is a diagram showing clock pulses output from a monostable multivibration radar in the apparatus shown in FIG.

FIG. 4 is a diagram showing an appearance of a conventional processing apparatus.

[Explanation of symbols] 1 power plug 2-1 to 2-4 switch 4 power supply thyristor 5 fuse 6 ammeter 7 rectifier circuit 8a, 8b resistance 11 positive terminal 12 negative terminal 13,15 extension cord 14 clip 16 holder 17 metal plate 18 Asbestos 23 Remote switch 24 Voltage detection unit 25 Sub transformer 31 Power switch unit 41 Power recovery setting unit

[Procedure amendment]

[Submission date] October 27, 1992

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

[Figure 1]

Claims (1)

[Scope of utility model registration request] 1. One of a pair of electrodes is connected to a metal, the other electrode is immersed in an electrolyte solution that contacts the surface of the metal, and a voltage is applied between the electrodes to remove the metal In a metal surface treating apparatus for treating a surface, switch means for switching on and off a power source for applying a voltage between the electrodes, and detecting that an overcurrent flows between the electrodes, An apparatus for treating a metal surface, comprising: a detection unit that is turned off through a switch unit; and a setting unit that periodically sets the power source to be turned on through the switch unit.