JPS5955363A - Electric discharge coating device - Google Patents

Abstract

PURPOSE:To finish a coated surface to a beautiful and thick surface in the stage of depositing and coating an electrode to be coated on the surface of the work, by interposing an induction coupling device of a voltage transformer or the like to an electric discharge power source for working. CONSTITUTION:An induction coupling device of a voltage transformer 3g or the like is interposed in an electric power source 3 section, and a circuit which turns a switching device 3d on and off by using a high-frequency oscillation output is provided on the primary side 3g1 thereof. Outputs of intermitent voltage pulse trains are drawn out from the secondary side 3g2 thereof and are made to the voltage pulses for electric discharge coating. Then rotating motion is kept applied on the electrode to be coated during the period from approaching and contacting to spacing, whereby the smooth and beautiful coated surface is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a discharge coating device, and in particular, a high-frequency power source is used in the discharge power source section of the device, and an inductively coupled device such as a transformer is used to create a high-frequency voltage between a workpiece electrode and a workpiece. The voltage pulse is applied to cause discharge.

Conventionally, in this type of discharge stage, the covering material electrode is attached to a vibrating device such as a vibrating device composed of a reciprocating electromagnet and a repulsion spring, or a vibrating device that rotates a biased heavy salmon body having a rotational bias axis using a rotating means. By facing the surface of the workpiece and exciting the electromagnet with an oscillator, commercial alternating current, or even charging/discharging current or voltage of a discharge capacitor,
The vibration movement is performed in the opposite direction to repeat contact and separation vibration on the surface of the workpiece at the tip of the coating material electrode, and a pulse discharge is generated in the gap in synchronization with the close contact, and the coating material electrode is heated at the time of contact. Covering is performed by welding and adhering the tip of the welded part to the workpiece and leaving it on the workpiece surface when separated from the welded state, and 1! By performing relative scanning movement or scanning processing feed between the electrode and the workpiece in a direction substantially perpendicular to the vibration direction, the entire surface of the workpiece or a necessary part of the covering material constituting the electrode is covered by electrical discharge. A layer can be formed.

However, if the so-called electrical discharge coating is performed by simply tapping the wandering material electrode against the surface of the workpiece in a vibrating motion in the opposite direction to open the contact, the tip of the covering material electrode may be damaged. Discharge and energization melts, and the softened part melts in a similar manner due to discharge and energization on the surface of the workpiece when it comes into contact with a light tap, and then welds to the softened part, pulling up the electrode of the workpiece (3)
Occasionally, the molten welded part is broken between the surface side of the workpiece and the tip of the electrode of the workpiece, for example, at the tip of the electrode where the amount of heat melt is small, and the electrode material is left welded on the surface of the workpiece, so that O is carried out. The broken surface of the bald patch, that is, the blood that has fallen on it, becomes a large uneven jagged surface, and the coated surface has a small surface roughness and has the drawback of not being finished neatly.

In addition, due to the light contact and separation with the tip of the electrode, the surface of the workpiece becomes uneven, and the coating material does not adhere uniformly to the workpiece surface.
The covered surface is uneven, there are thin parts of the covered layer, many holes and weak points that are rather large than pinholes, and the covered surface is thin and the density of the covered layer is small. It was hot.

In consideration of these points, the present inventors have first determined that the axis 1 in the contact/separation direction is attached to the target electrode during the period from at least close contact to separation due to the movement of near contact/separation. By applying rotational motion around an axis that is offset from the axis of the coating material electrode, the surface to be coated can be smoothed with little surface roughness, resulting in a beautiful finished surface, and the coating thickness can be increased.
It became clear that the layer was denser, without holes or weak points, and that the surface of the workpiece under the covering layer was less uneven. In active gases, reducing gases such as hydrogen, or mixtures thereof, or equivalent scum, vapor,
Furthermore, it was proposed to carry out electrical discharge coating machining by applying vibrational motion and rotational motion of the coating material electrode to the workpiece in liquid at the same time.

Therefore, as a discharge power supply unit used in a conventional discharge coating device using contact/release vibration, a capacitor system using a capacitor charging/charging mechanism has been commonly used. In the discharge encasing method, in addition to the liquid level scanning operation in the discharge applied force loe, the coating material electrode is driven close to the surface of the workpiece to start the discharge, and after contact welding, the two are separated. During the above period until they separate, the contact between the two, and furthermore, the contact weld part moves relative to each other in the direction perpendicular to the vibration direction and parallel to the surface of the workpiece while being suppressed or rubbed, contributing to the coating effect. During this operation, it is necessary that a discharge, short circuit, or current heating current with desired characteristics flows in the contact area between the two.
With an L source, it is difficult to create discharge characteristics suitable for various purposes.

For this purpose, for example, as described in Japanese Patent Publication No. 46-28.162, the output of a DC voltage source is controlled on and off by an electronic switching element such as a transistor, that is, the duration of the voltage pulse or discharge pulse, and the pulse Pause time between
Alternatively, the current imaging width, etc. can be arbitrarily adjusted and set using Ichihara, which can be controlled, but the configuration is complicated, and as mentioned above, 1! Since it is necessary to supply a discharge or energized heating current when there is a contact short circuit between the workpieces, the conventional conventional configuration has poor power efficiency due to the need to protect the electronic switch element, etc., and is therefore large in size. There were drawbacks.

Taking these points into consideration, the present invention includes an inductive coupling device such as a transformer interposed in the power supply section, and a circuit that turns on and off the switching device using high-frequency oscillation output on the primary side. Installed, intermittent voltage pulse train output is output from this secondary side, and the bamboo coating process is performed! This is a pressure pulse.

The figures show an embodiment of the present invention, and Figure 1 is a schematic configuration diagram of the discharge coating device according to the embodiment, and Figures 1 and 2 are block circuit connection diagrams of the embodiment of the power supply section B for discharge machining.

In the figure, 1 is a rod-shaped, short cylindrical or pipe-shaped covering material electrode such as a sintered body of 10% CO (tungsten carbide binder makes the amount slightly larger) - the remainder is a WO sintered body, and 2 is a covering material electrode made of, for example, iron material. The workpiece is opposed to the electrode 1, and a power source 3 for machining is connected between the two to supply intermittent voltage pulses. Details of an embodiment of the power source 3 for machining are shown in Figure 2. .

Reference numeral 4 denotes a support shaft having a support holder 4a for fixing the coating electrode 1, and is integrally connected to the shaft of the motor 5.

Reference numeral 6 denotes a vibrating device main body, in which one end of a vibrating piece 6a made of a spring material is fixed to enable elastic vibration, and the other end is a vibrating free end.
A support shaft 4 is rotatably held in a coupling portion 8 provided at the free end by a ball bearing 8a. Reference numeral 7 denotes an electromagnetic vibration device which applies intermittent excitation at a predetermined frequency to the excitation coil 7a from a power source 9 to attract and release the iron piece 6b.

In this way, the coating material electrode 1 is rotated by the motor 5 around an axis slightly offset from its central axis, and is brought into contact with and released from the workpiece 2 by the vibrating motion by the vibration device 6, thereby performing electric discharge covering machining. .

Next, Figure 2 is a block diagram of the block circuit of the electric discharge machining power supply section 3, which includes a high frequency oscillation section 3a and a low frequency excavation section 3b, and the outputs of both oscillation sections are logically multiplied by an AND circuit or the like. The circuit C is manually operated to output a high frequency output intermittently at a low frequency, and the output signal is sent to an electronic switch 3 such as a transistor.
d and performs discharge power output through base control and the like.

The high frequency oscillator 3a outputs a high frequency voltage pulse signal having a duration of, for example, around 1 to 10 μB and a pause time of around several μ days or less, whereas the other low frequency oscillator 3b outputs, for example, 20/I B A device that outputs a low frequency voltage pulse signal having a duration of around 5 ms and a pause time of 10 μS to 'lm5iil, and the duration fMl and pause time of each voltage pulse can be set variably. In this case, both voltage pulse signals are preferably synchronized (for example, a high frequency voltage is generated within a period in which a low frequency voltage pulse signal is generated), and a certain number of pulse signals enter exactly the predetermined number, which causes a rest period. (repeated for each low frequency voltage pulse) are turned into a composite signal by an AND circuit 6C, and the composite signal is used to control a driver circuit (not shown) provided as needed to control the electronic switch 5 (L). Input as a signal. 5θ is a processing DC power source obtained by transforming and rectifying a commercial AC, for example, 3f is a smooth f-wave mouth path of a capacitor tube, and these power sources are a high-frequency power source with an air core or iron core, as well as the electronic switch 3d. Custom made good transformer 3
It is connected in series to the primary winding 3H of t. 3ft is the secondary winding of the transformer 5f, which passes through the rectifier 3h and outputs the output 6.
Normally, electrode 1 is added as a positive electrode to a discharge gap (not shown) from 1 to 1.

Thus, the output 51 outputs a power pulse having the duration and pause time of 5 pulses in the output of the low frequency oscillator 3b, but each power pulse is equal to the output voltage pulse of the high frequency oscillator 3a. The accumulation of the duration and pause time of
The electronic switch 3d does not completely respond to turn on and off (7:[However, it is essentially turning on and turning off high frequency waves), so the safety resistor 3j is a thick one. It is possible to conduct current in an intermittent short-circuit state of the output 3 without having to do so.

1. For example, when the electric discharge compound machining action is performed at a lower frequency vibration (for example, 1Ω (around 1H2) and a low electrode rotation speed (for example, several tens of DR, P, M), the low frequency excavation part 3b The output X7f and pressure pulse are made to have a high frequency, for example, with a duration of 200 μ8 and a rest time of 50 μe, while the output voltage pulse of the high frequency oscillator 3a is used with a low frequency, such as a duration of 6 μ days and a rest time of 5 me. On the contrary, change the swing D number (for example, 400Hz)
When coating is performed at a high rotational speed (for example, 1500R, P, M, etc.), a low frequency voltage pulse is applied for a duration of 100 seconds.
0μθ, pause time 100mθ.

The conditions of the 1FL pressure pulse can be selected and set from a wide range according to the purpose, such as coating by adjusting the high frequency pulse (-pulse to 15 μS duration and 1 μs rest time), and stable discharge wave υ Processing can be performed with high power efficiency.

In an actual example, when an 8550 steel workpiece is coated with a rod-shaped covering material electrode of 10% Co-balance Wc sintered body under the condition that the roughness of the processed surface of the bale is 34μRmax, the conventional capacitor charging/discharging method In the case of the power source, the contact/release frequency of the covering material electrode is IDDDHz and the hammer processing speed is approximately 0.
In contrast, in the case of the present invention, the rotation of the zero running material electrode was 15OR,P,
M, the same perturbation number 100 Hz and the same perturbation 'fIL as above.
Low frequency voltage pulse duration 250μ days when using poles;
Rest time 50μ days, high frequency voltage pulse duration 2.5μ
When the pause time is 3μθ, approximately 05mm/5
It became rn in.

Furthermore, the other coating materials are the same under the same conditions! The number of rotations of the pole is 50OR, P
, M, and a frequency of 30 DI (z), the power source configuration according to the present invention has a value of 0.4 mm'15 r+11n, and the practical effect on the covering speed is great.

[Brief explanation of the drawing]

Figure 1.1 shows a schematic diagram of the device to be protected according to the present invention.
Figure 4 and Figure 2 are diagrams of the block circuit 11'η of the power supply section. In the figure, 1 is a workpiece electrode, 2 is a workpiece, and 3 is a power source. 6a is a high frequency oscillation section, 3L+ is a low frequency oscillation section, 5
c is an AND circuit, 3d is an electronic switch, 5f is a transformer,
3h is a rectifier, 4 is a support shaft, 5 is a motor, 6 is a vibration device main body, 6a is a vibrator, 6b is an iron piece, 7 is an electromagnetic vibration clamp, 8 is a coupling part, and 9 is a vibration power source.

Claims (1)

[Scope of Claims] (11) A covering material electrode is arranged to which vibration of contact and separation and rotation around an axis in the contact and separation direction are applied to the surface of the workpiece, and between the electrode and the workpiece In a device that connects a machining discharge power supply and applies intermittent voltage pulses, the generated electrical discharge welds and coats a workpiece electrode on the surface of a workpiece.
As the discharge power source for machining, a switch device is turned on by a high frequency signal. A discharge coating device characterized in that a voltage pulse output is taken out from the secondary side of an inductive coupling device equipped with a primary side circuit that is turned off.