JPS6159398B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a plating device for forming a thick and uniform plating layer over the entire surface of a processed part of an electroforming mold or an object to be plated.

In conventional plating, the mold or the workpiece is inserted into the plating solution with a sufficiently wide distance between the electrode and the workpiece, and the electric field strength is applied to the entire surface of the workpiece to plate the workpiece at once. Therefore, when there are irregularities on the surface of the workpiece, the electric field strength is weak in the recesses and corners, causing electrical shadowing, making it difficult to form a plating layer, and making uniform plating impossible.

For this reason, the present invention performs partial plating using an electrode with a small area, and performs plating while controlling the position and spacing of the facing gap using NC control or a copying control device.
In addition, a vibrating device is installed on the electrode to vibrate it, thereby maintaining stable and high-density current conduction, and plating is performed while selecting and replacing the electrode according to the shape of the machined surface of the workpiece. This is characterized in that uniform plating can be performed over the entire surface of the processed part of the mold or workpiece.

The present invention will be described below with reference to the drawings of one embodiment. Reference numeral 1 denotes an electroforming mold whose plating surface has irregularities and makes uniform plating difficult, and an electrode 2 is placed opposite the mold for plating. As shown in the figure, the facing area of the electrodes is small,
It can be easily inserted into the recess of the mold 1 and can be opposed to each other with a narrow interval. A vibration horn 3 serves as a support for mounting and supporting the electrode 2, and acts on the electrode 2 by increasing vibrations generated by a vibrator 4 such as crystal. The vibrator 4, the horn 3, and the electrode 2 are fixed together, and a plurality of integrated electrode tools with different shapes and dimensions are prepared so that the electrodes can be replaced. Reference numeral 5 denotes an electrode support head, which fixes the integral electrode tool with a magnetic chuck, and can control its movement in the mutually perpendicular X, Y, and Z axes, and controls the position of the opposing gap between the mold 1 and the electrode 2. You can control the interval. 6, 7, and 8 are drive motors for each axis, which are controlled by an NC control device 9. 10 is a plating liquid supply pump, which connects the head 5 to the horn 3;
The plating liquid is supplied to the gap through a jet hole provided through the electrode 2. The liquid supply pipe 11 that communicates with
A control valve 12 is provided, and this valve control is also automatically controlled by the NC control device 9. 13
The plating effect is improved by using a power source, usually a pulse power source, which supplies a plating current by applying current with polarity such that mold 1 is a cathode and electrode 2 is an anode. 14 is a rotary plate for storing a plurality of electrode tools 2a, 2b, 2c, etc. which are integrated with electrode 2, horn 3, and vibrator 4; 15 is a material handling device, both of which are controlled by NC control device 9; The disk is rotated and the selected electrode tool is replaced with the one fixed to the head 5 by the operation of the material handler 15, and the shape and area of the electrode 2 are selected to correspond to the plating part of the mold 1 and replaced. Then, we select the best electrode and perform the plating process.

The stored electrode tools 2a, 2b, 2c... are equipped with various types of tip electrodes, from thin to thick, and from short to long, and are used to create grooves and recesses depending on the shape of the machined surface of the mold 1 to be plated. When machining corners, etc., choose a thin electrode, narrow the gap between the facing electrodes, and efficiently plate the shadowed areas of the electrodes, making it easy to fill in the gaps with metal deposition. The drive of the motors 6, 7, and 8 for the X, Y, and Z axes is controlled by the NC control device 9, and the selected electrode 2 is placed in a part of the machining part of the mold 1 with a minute gap of about 0.5 to 1 mm or less. Pump 10 is placed opposite the pump.
A controlled plating liquid is jetted from the plating liquid, and electricity is supplied from the power source 13 to perform plating. Electrode 2 during plating processing
Vibration such as ultrasonic waves is applied to the electrode, and a large amount of new plating solution is circulated and supplied to the minute gap. Generated gases, decomposed products, etc. can be easily removed and cleaned by the pumping action and stirring action of the electrode vibration, and the anode electrode Eliminate impurities such as ions and oxides that adhere to the surface of 2.
Since the electrode surface is always kept in an active state, even with a thin electrode 2 with a small opposing area, a high current density of about 0.5 to 5 A/cm ² can be stably and continuously passed, resulting in high quality plating with high density crystals. Since the process is performed at a high speed and the processed area is gradually plated by moving the electrode 2 while stably maintaining the activated state caused by electrode vibration, high-quality uniform plating can be easily achieved from end to end. Machining is carried out while selecting the optimal electrode shape and size according to the shape of the mold surface, and movement and scanning is performed by the NC control device 9, so that uniform plating is applied to the entire machining surface of the mold 1.

Through this series of plating processes, electrically dark areas such as concave parts of the mold surface are electrodeposited and filled, and once the mold surface is flattened to some extent, the electrode 2 is moved back by controlling the Z axis to close the plating gap. The electric field is controlled to be wider than before, and the working electric field area is expanded, and the plating process is continued by moving and scanning the entire mold surface in the same way.
At this time, the concave portion of the mold 1 described above has already been filled by metal deposition and the electrically shaded portion has disappeared or decreased, so by widening the gap and plating over a wide area, stable plating can be achieved over the whole. As the process progresses, high-quality plating is performed at high speed, and a predetermined thick plating layer can be formed and finished on the entire surface of the mold. After the concave part of the mold surface is filled with the deposited metal and the electrically shadowed part disappears, the working electric field area can be expanded by replacing the electrode with a larger area. Processing can be performed by stopping the moving scan.

Note that the NC control device 9 controls the electrode tools 2a, 2.
The signals for widening the plating gap by selective exchange of b, 2c, etc. and Z-axis control are carried out step by step every time a predetermined plating step is completed.The control signals are recorded on a tape, and each step is controlled during playback. Because the process proceeds fully automatically, the desired plating and electroforming processes can be carried out stably and easily.

In addition, a microcomputer can be used in the NC control device that generates and controls control signals, and can perform corresponding control while detecting the state of the machining gap, controlling current density, plating liquid flow rate, flow rate control, and electrode vibration. can be adaptively controlled. Also, when using pulses for energization, the pulse width, pause width, frequency,
It is also possible to control the peak value, etc., and the electrical conditions can always be controlled to the best condition.

The electrode vibration uses vibrations from a minimum of 50 Hz to a maximum of about 500 KHz, and can be made by superimposing vibrations of about 50 to 500 Hz and ultrasonic vibrations of 1 KHz or more.

In addition, by controlling the vibration intermittently and providing a rest period for the vibration, stable plating can be achieved by changing the vibration, and fatigue of the electrode can be prevented and thin wire-shaped electrodes can be processed. Any electrode material can be used for the electrode, but if one plated with Pt or the like is used, it can be used as a wear-resistant electrode.

The plating liquid can be supplied in jet form from a nozzle facing the processing part (not shown), and the plating liquid can be supplied in a jet stream from a nozzle facing the processing part (not shown).
Plating may be performed while 1 and the electrode are immersed in a plating solution. Relative movement of the position and interval of the plating gap can be controlled by fixing the electrode 2 and moving the mold 1, or the relative movement can be shared between the electrode side and the mold side.

As explained above, in the present invention, an electrode with a small facing area is provided as an anode electrode, and the electrode is vibrated at high frequency while facing a part of a mold or a workpiece at a sufficiently narrow interval, and the position and interval of the facing gap are adjusted by NC. Since the plating is carried out sequentially while moving over the entire surface of the mold or workpiece under control or copying control, high-quality plating can always be performed with high current density, and the machined surface of the mold or workpiece can be plated at high current density. Since the electrodes are selected and replaced according to the shape of the part, the electrically shaded areas on uneven surfaces can be evenly plated, and the entire surface can be plated uniformly at high speed. It enables high-speed plating that is about 2 to 5 times faster than when the electrodes face the mold surface with a wide gap, and the activated gap and electrodes face each other with a small gap and generate high current density. By plating, it is possible to perform high-quality plating with small crystals in the plating layer and high elongation rate, and it is possible to perform high-quality uniform plating on a complex mold surface with large irregularities and deep concave parts, and on a wide surface, which is extremely effective in practical terms. This is a large one.

Plating and electroforming have the effect of effectively plating Ni, Cr, Cu, Au, Pt, and other arbitrary materials.

[Brief explanation of the drawing]

The drawing is a configuration diagram of an apparatus according to an embodiment of the present invention.
1 is the mold, 2 is the electrode, 4 is the vibrator, 5 is the head,
6, 7, 8 are drive motors, 9 is an NC control device, 1
0 is a pump, 12 is a valve, 13 is a power supply, 14 is a disc, 15 is a material handling device, 2a, 2b, 2c...
... is an electrode tool. 〓〓〓〓〓

Claims (1)

[Claims] 1. A device for plating the mold or workpiece with a cathode by applying current with polarity such that the electrode serves as an anode with the electrode interposed between the mold or workpiece inserted in a plating solution in a tank and the electrode. In this method, an electrode with a small facing area is provided as the electrode, a vibration device is provided to apply vibration to the electrode, and the vibrating electrode is placed in a facing gap facing a part of the mold or workpiece at a sufficiently narrow interval. A control device for NC control or copying control of the position or position and interval of the mold or workpiece is provided, and an automatic electrode exchange device for selectively replacing the electrode according to the shape of the machined surface of the mold or workpiece is provided. An electroplating device that is capable of uniformly plating the entire processed portion of a workpiece without shadowing.