Patent ID: 8414303

Claim:
A wiring unit for robots having a rotary joint with which two members are mutually rotatably coupled, an electronic wiring passing through the two members and the rotary joint, the wiring unit comprising: a wiring case comprising i) a cylindrical housing whose both ends are opened in an axial direction of the housing and ii) a reel a) having a cylindrical core member located in an inner space of the housing and the reel comprising two lid members mutually integrated with the core member and located on both axial end sides of the inner space of the housing, and b) being relatively rotatable to the housing, the housing and the reel respectively being linked respectively with the two members of the robot; a slide aid comprising an annular rotary plate i) having both ends which produce a vacant space therebetween, ii) being placed to surround the core member in a radial direction of the housing, and iii) being rotatable about the core member, and a plurality of rollers provided on the rotary plate to be located around the core member and rotatable about an axis thereof; and a flexible printed wiring board, which is belt-shaped, in which a plurality of electrically conductive wires for the electrical wiring are contained with electrical insulation therebetween, and which has i) two length-width end portions one of which is linked with the core member and the other of which is linked with the housing and ii) a rest portion other than the two length-width end portions, which is located within the inner space of the housing, is wound and unwound in inside and outside spaces of a set of the rollers in the radial direction via the vacant space such that that the rest portion is moved on and along the rollers and is wound and unwound oppositely in directions between the inside and the outside spaces of the set of the rollers in the radial direction, wherein the flexible printed wiring board is folded back via the vacant space left by the rotary plate so that the flexible printed wiring board has an arc folded-back portion which changes a winding direction thereof in the vacant space, and is provided with an outer protective board made up of a polyimide film which is laid over the flexible printed wiring board so that the outer protective board is located outermost in the arc fold-back portion.