Plating pretreatment apparatus and method for cylinder block

An apparatus for plating pretreatment of a cylinder block, comprising:

• a seal jig sealing one end of a cylinder inner wall surface of a cylinder in the cylinder block;
• and
• an electrode performing a plating pretreatment of the cylinder inner wall surface,
• wherein the seal jig is disposed to one end of the electrode through a female thread part, a seal jig attachment plate and bolts for fastening,
• wherein the seal jig is disposed at an upper end portion of the electrode, the electrode disposed to face the cylinder inner wall surface, the electrode forming a gap flow channel between the cylinder inner wall surface and the outer surface of the electrode, the electrode having an in-electrode flow channel formed therein,
• wherein the gap flow channel communicates with the in-electrode flow channel via a communicating hole formed in the gap flow channel and by a lower surface of the seal jig and the upper end portion of the electrode at a position closest to the seal jig and an upper end portion of the gap flow channel, the gap flow channel being adapted to introduce a treatment liquid to the cylinder inner wall surface and flow the treatment liquid therethrough toward the seal jig, and the in-electrode flow channel is adapted to receive and flow therethrough the treatment liquid having passed through the communicating hole, and
• wherein the flow channel cross-sectional area of the communicating hole is smaller than the flow channel cross-sectional area of the gap flow channel.