Method of electrodeposition coating on a hub

Abstract

A method is realized for easily performing, without using a masking tape, an operation to accurately form a coating film 31 only on a coated section (α 8 ) partly formed on the surface of a hub main body 13 a. The upper end face of a rubber closed end cylindrical masking cover 32 is elastically pressed against the outside end surface of a cylindrical section 16 forming the hub main body 13 a . As a result a border section between the coated section (α 8 ) and the portion adjacent to the coated section (α 8 ) can be made liquid-tight. In this state, coating particles are electrodeposited on the coated section (α 8 ) by bringing a coating liquid 28 discharged from a liquid supply tube 29 into contact with the coated section (α 8 ). By adopting such a method, the problems can be solved.

1 . A method of electrodeposition coating on a hub where in order to form a coating film on a desired range that includes at least one part of a surface of a cylindrical section among the surfaces of a hub that constitutes a wheel support hub unit that is respectively provided with an attachment flange on a part close to an outside end of an outer peripheral surface for supporting and fixing a wheel and a braking rotating member, and with the cylindrical section for externally engaging at least one of the wheel and the braking rotating member on an outside end section, coating particles in a coating liquid are electrodeposited on this desired range, with the desired range in contact with the coating liquids
 wherein the operation of electrodepositing the coating particles on the desired range is carried out with a masking cover in contact with or closely opposing to a border part on the surface of the hub between the desired range and a range adjacent to this desired range.   
     
     
         2 . A method of electrodeposition coating on a hub according to  claim 1 , wherein a border sections which is to come into contact with, or closely oppose, the masking cover, is a periphery part of an outside end surface of a cylindrical section that constitutes the hub. 
     
     
         3 . A method of electrodeposition coating on a hub according to  claim 1 , wherein a hole that passes through the hub in an axial direction is provided in a center section of the hub, and a border section, which is to come into contact with, or closely oppose, the masking cover, is an annular section that surrounds an outside end opening of the hole of the outside end surface of the hub which is surrounded by the cylindrical section. 
     
     
         4 . A method of electrodeposition coating on a hub according to  claim 2 , wherein after coating particles in a coating liquid have been electrodeposited onto an inner surface of a cylindrical section that constitutes the hub in a state where a radial direction inner side of the cylindrical section is filled with the coating liquid, this coating liquid is drained to the exterior of this cylindrical section through an outside end opening of the cylindrical section, after which gas is blown into the outside end opening of this cylindrical section. 
     
     
         5 . A method of electrodeposition coating on a hub according to  claim 1 , wherein, as the masking cover, a masking cover is used, which has an entirely cylindrical shape, a section on the outer peripheral surface thereof close to a tip end that can be pressed against the entire inner periphery part of the outside end surface of the cylindrical section that constitutes the hub so as to be liquid-tight, and a liquid drained passage formed on a part of the tip end section able to enter within the cylindrical section that connects the outer peripheral surface and inner peripheral surface of said portion. 
     
     
         6 . A method of electrodeposition coating on a hub where in order to form a coating film on a desired range that includes at least a surface of a cylindrical section among the surfaces of a hub that constitutes a wheel support hub unit that is respectively provided with an attachment flange on a part close to an outside end of an outer peripheral surface for supporting and fixing a wheel and a braking rotating member, and with the cylindrical section for externally engaging at least one of these wheel and braking rotating member on an outside end section, coating particles in a coating liquid are electrodeposited on this desired range, with the desired range in contact with the coating liquid,
 wherein a plurality of partial ranges that respectively become a range of one part of the desired range are set, and the operation of electrodepositing said coating particles on the desired range is carried out in separate processes for each of said partial ranges.   
     
     
         7 . A method of electrodeposition coating on a hub according to  claim 6 , wherein one of the respective processes is a process of electrodepositing the coating particles onto a section among the surfaces of the cylindrical section that is in contact with the coating liquid while only the cylindrical section is dipped in the coating liquid contained in a coating liquid tank having an open top section. 
     
     
         8 . A method of electrodeposition coating on a hub according to  claim 6 , wherein a plurality of coating devices at least provided with coating liquid tanks that contain the coating liquid, and having an open top end, are prepared, and one coating device is selected among the respective coating devices for each process, and the selected coating device is used to carry out the process. 
     
     
         9 . A method of electrodeposition coating on a hub according to  claim 6 , wherein one coating device provided with a coating liquid tank that contains coating liquid and that has an open top end, and a nozzle that sprays the coating liquid upwards is prepared, and each step is performed using only this coating device. 
     
     
         10 . A method of electrodeposition coating on a hub according to  claim 9 , wherein relative positions of liquid levels of the coating liquid contained in the coating liquid tank and of the nozzle to the hub, and a way of spraying the coating liquid to be sprayed from this nozzle are changed for each of the steps. 
     
     
         11 . A method of electrodeposition coating on a hub where, after forming an undried coating film on a surface of a cylindrical section among the surfaces of a hub that constitutes a wheel support hub unit respectively provided with an attachment flange on a part close to an outside end of an outer peripheral surface for supporting and fixing a wheel and a braking rotating member, and with the cylindrical section for externally engaging at least one of the wheel and the braking rotating member on an outside end section, by electrodepositing coating particles onto the surface, the coating film is baked onto the surface of the cylindrical section by heating the undried coating film to dry it,
 wherein the heating temperature of the undried coating film is below 140° C.   
     
     
         12 . A method of electrodeposition coating on a hub where, after forming an undried coating film on a surface of a cylindrical section among the surfaces of a hub that constitutes a wheel support hub unit respectively provided with an attachment flange on a part close to an outside end of an outer peripheral surface for supporting and fixing a wheel and a braking rotating member, and with the cylindrical section for externally engaging at least one of the wheel and the braking rotating member on an outside end section, by electrodepositing coating particles onto the surface, the coating film is baked onto the surface of the cylindrical section by heating the undried coating film to dry it,
 wherein the heating temperature of the undried coating film is between 140° C. and 220° C., and the operation of heating the undried coating film is carried out while the hub is being cooled from an inside end side.