Method and apparatus for applying composite plating on hollow member

An apparatus for applying composite plating on an internal surface of a hollow member comprising:

• an electrode which is inserted into the hollow member with a predetermined clearance to an internal surface of the hollow member, the hollow member being held in a condition in which a generatrix of the internal surface extends vertically;
• a composite plating liquid supply passage having a discharge opening which is in communication with an opening at a lower end of the hollow member;
• means for entraining bubbles of a gas into a composite plating liquid which is supplied into the clearance through said supply passage;
• wherein said discharge opening is provided with a restricted passage portion whose internal diameter is equal to or smaller than an outer diameter of said electrode;
• and
• wherein a lower end portion of said electrode is made gradually smaller in diameter towards the lower end thereof.

An apparatus for applying composite plating on an internal surface of a hollow member comprising:

• an electrode which is inserted into the hollow member with a predetermined clearance to an internal surface of the hollow member, the hollow member being held in a condition in which a generatrix of the internal surface extends vertically;
• a composite plating liquid supply passage having a discharge opening which is in communication with an opening at a lower end of the hollow member;
• means for entraining bubbles of a gas into a composite plating liquid which is supplied into the clearance through said supply passage;
• and
• wherein said means for supplying a composite plating liquid comprises two gas entraining passages which are disposed to face each other at a predetermined distance between a front end of each, said gas entraining passages being disposed substantially at right angles to the flow direction of the composite plating liquid.