JPS6013070B2 - Electric discharge coating processing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention involves placing electrodes of a covering material facing three workpieces and applying pulse discharge while performing contact vibration or sliding movement between the two to remove part of the electrode material from the workpiece. This invention relates to improvements in electrical discharge coating processing equipment for welding and coating.

If the coating process is continued for a long time, the increase in the amount of coating process will gradually decrease, and eventually the part of the coating layer that has been coated will become electrically discharged.
The amount of processing could not be increased beyond a predetermined value because it could melt and scatter due to heating or the like, or transfer and deposit on the electrode side, resulting in a reduction in weight. According to various tests and studies, the reason for this is that when the surface of the coating becomes uneven, it becomes difficult to laminate the coating even if the coating is processed again. In view of the above-mentioned points, the present invention is to process the coating by alternately switching between applying a pulse discharge between the coating material electrode and the workpiece and leveling and polishing the coating surface. Since the surface becomes a smooth surface and the coating is processed and laminated on top of the surface, the amount of coating can be increased in proportion to time.

Therefore, we provide an optimal device that performs this coating and polishing alternately. Using DC as a power source, a high frequency (for example, IK to 500 KHz) alternating current or pulse is generated by controlling the on/off of a switch, and the alternating current or pulse is transformed. An inverter is provided that outputs alternating current or direct current obtained by rectifying the alternating current by transforming the alternating current with a transformer, and the pulse output end of the inverter is connected between the coating material electrode and the workpiece via a changeover switch, and Alternatively, the DC output end is connected to the head for polishing by vibration or rotation via a switch. The present invention will be described below with reference to an embodiment of the drawings. 1 is an input terminal of a commercial AC power source, and 2 is a rectifier which directly rectifies the AC to obtain a DC power.

3 and 4 are switches (transistors) for on/off switching control of the DC output; of course, one switch may be used to turn on and off to generate pulses.

5 is a transformer that transforms the alternating current generated by turning on and off the switch 34, and half-wave rectification 6 converts the high frequency alternating current of the secondary coil.
A pulse rectified by is applied to the discharge gap.

Reference numeral 7 denotes a vibrating head, at the tip of which a coating material electrode 8 made of carbide or the like is attached, and facing the workpiece 9 for coating.

10 is a vibrator such as a haze distortion, magnetostriction, electromagnetic coil, etc., 11 is a horn, and 12 is a polishing tool, which supplies the output high frequency of the transformer 5.

13 is a 3-tap changeover switch inserted in the processing pulse circuit, 14 is a 3-tap changeover switch inserted in the circuit of the vibrator 10, and 15 is a 3-tap changeover switch inserted in the circuit of the vibration head 7, all of which operate in conjunction with each other. do.

Reference numeral 16 denotes a high frequency oscillator, which applies an oscillated high frequency wave Z to the switches 3 and 4 through a transformer 17 for control.

Usually, the oscillation frequency is about IK to 500K.
18 is an oscillator that interrupts the oscillation, and the oscillation frequency is 10
It is set to about 0 to 1 dish, and the output pulse is set to switch 3,
In addition to the rectifier J flow switches 19 and 20 (thyristor) inserted in the control circuit of No. 4, on/off control is performed.

The coating process uses moving tap changeover switches 13, 14, 1.
5 to 1 tap as shown in the figure, the electrodes 8,
A half-wave rectified high frequency pulse of IK to 500 KHz is supplied between the workpieces 9 via a switch 13 connected thereto, and a low frequency interruption control pulse of about 100 to 10 KHz from an oscillator 18 is supplied to the vibration head 7 through a switch 15. added to,
As a result, the coating material electrode vibrates in contact with and releases from the workpiece 9,
Pulse discharge is repeated to perform the coating process.

In machining, the portion of the tip of the electrode 8 heated by the discharge is transferred and welded to the workpiece 9, and a laminated coating is formed by repeating the pulsed discharge. The electric discharge machining pulse is an AC-DC-HF-p composed of a rectifier 2, switches 33, 4, a transformer 5, etc.
The inverter output is supplied from the inverter of Yamase, and the high frequency pulses oscillated by switches 3 and 4 at IK to 500 KHz are turned on and off by the low frequency pulses of 100 to 1 female Hz from the oscillator 18. The machining pulses that are interrupt-controlled and therefore supplied to the discharge gap are pulses in which a high-frequency pulse train is repeated at interrupt intervals.

On the other hand, the vibration head 7 is controlled to vibrate by the interruption control pulse of the oscillator 18, and the electrode 8 vibrates 4 times in contact with and away from the workpiece 9, so that while the electrode 8 vibrates for one cycle is close to or in contact with the workpiece 9, A large number of high-frequency machining pulses are supplied, electrical discharge is repeated, coating is performed, and the electrode 8 is connected to the workpiece 9.
When the electrode leaves the workpiece 9, the supply of machining pulses is stopped by the interruption interval control, the workpiece is cooled during this period, and when the electrode approaches the workpiece 9 again due to vibration, the high-frequency pulse discharge is repeated. Covering with the electrode material is performed from this step. As mentioned above, the discharge repeats short, small discharges during high-frequency pulses, so the coating surface roughness can be machined on a smoother surface compared to when a large discharge equal to the electrode frequency is used, but as the coating time elapses, Surface roughness also worsens. In such a case, even if the coating process is continued, an increase in the amount of coating cannot be expected, and the amount may actually decrease.
Then, change the changeover switch and change it to 2 taps. At this time, the switch 13 is turned off, the switch 14 is closed, and a high frequency wave is applied from the transformer 5 to the vibrator 10, causing it to vibrate at a high frequency. The vibration propagates through the horn 11 and is transmitted to the polishing tool 12 at the tip, which performs vibration polishing on the coated surface of the workpiece 9. In addition, for this polishing, when a carbide material is used for the covering material electrode 8, the electrode can be used also as a polishing tool, and when the changeover switch is switched to 3 taps, the high frequency of the transformer 5 is transmitted from the switch 15 to the vibrating head 7. The coated surface can be vibrated and polished by the electrode 8 supplied with high frequency vibration.

When the surface is leveled and polished in this manner and a smooth surface is obtained, the selector switch is switched to 1 tap and coating by discharge is performed again.

Alternate switching between coating and polishing with this changeover switch is as follows:
The switching time can be controlled so that optimum coating and polishing is always performed, and can be arbitrarily adjusted depending on the material, the thickness of the coating layer, etc. In this way, since the coating process always overlaps and coats a smooth surface, an increase in the amount of coating can be expected.
FIG. 2 is a graph showing the results when a WC-Co carbide electrode was used to apply discharge coating to the surface of one piece of SK4.

In the present invention, the inverter oscillates at one cycle Hz, the interruption control is performed at 1 Hz, the discharge pulse is applied by half-wave rectification of the inverter output, and the vibration head of the electrode is vibrated by adding the interruption control pulse. However, the machining current was set at Mean Hiro.
In addition, the coating surface was leveled and polished by applying high frequency output from an inverter to a vibrating tool, and a changeover switch was used to alternately perform coating and polishing. The conventional example for comparison is one in which vibration is performed at around 100 degrees and processing is performed using a processing average current ship. It was confirmed that the amount of coating for the same processing time can be increased by about three times or more according to the present invention. As mentioned above, an inverter can be constructed in a small size because it directly rectifies a commercial AC power supply, generates high-frequency AC or pulses by controlling the on/off of a switch, and transforms it with a transformer to obtain a specified voltage output. , has extremely high responsiveness at high frequencies, and can stably generate processing pulses of the above-mentioned IK to 500 KHz.

Further, it is very easy to interrupt the high frequency at a low frequency of about 100 to 10 KHz, and to obtain the desired processing pulse train by the interrupt control. Of course, this interruption control is not necessarily the purpose, but by performing interruption control, the cooling effect, etc. can be optimally controlled, so that the processing effect can be further enhanced. The inverter output is controlled by a changeover switch and can be used for both coating and polishing.By alternating coating and polishing, the amount of coating can be significantly increased. Since the coating and polishing are switched alternately, the switching time can be arbitrarily controlled to perform the optimal coating and polishing depending on the material, coating thickness, etc. This increases the amount of coating processing and creates a smooth coating. surface is easily obtained. In the above embodiments, the vibrating head 7 of the coating material electrode may be vibrated by a separate AC power source, or the electrode 8 may be rotated and coated while sliding on the workpiece 9. Further, the polishing head 12 can also utilize rotational polishing, and in this case, the output of the transformer 5 of the inverter can be controlled by adding direct current or pulses to the rotary motor.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of an embodiment of the present invention, and FIG. 2 is an experimental graph diagram. 1 is a commercial AC input terminal, 2 is a rectifier, 3 and 4 are switches, 5 is a transformer, 6 is a half-wave rectifier, 7 is a vibration head, 8 is an electrode, 9 is a workpiece, 10 is a vibrator, and 11 is a horn, 1
2 is a polishing tool, 13, 14, 15 are switching switches, 16
is a high frequency oscillator, 17 is a transformer, 18 is a low frequency oscillator,
19 and 20 are rectifier switches. Figure 1 Figure 2

Claims (1)

[Claims] 1. Coating by pulse discharge between the coating material electrode and the workpiece,
In electrical discharge coating processing equipment that alternately performs smoothing and polishing of the coated surface, a DC power source is used to generate high-frequency alternating current or pulses by on/off control of a switch, and the alternating current or pulses are transformed by a transformer. An inverter that outputs alternating current or direct current obtained by rectifying the alternating current is provided, and the pulse output end of the inverter is connected between the coating material electrode and the workpiece via a changeover switch, and the alternating current or direct current output of the inverter is An electrical discharge coating machine whose end is connected to a polishing head using vibration or rotation via a switch. 2. The electrical discharge coating processing apparatus according to claim 1, wherein the inverter frequency is 1K to 500KHz. 3. The electric discharge coating processing apparatus according to claim 1, wherein the changeover switches are interlocked.