Electric slide rail device, vehicle seat equipped with electric slide rail, and manufacturing method for electric slide rail

A manufacturing method for an electric slide rail device,

• wherein the electric slide rail device comprises:
• a rail having a channel cross section and extending along a first direction;
• a slider that is received in the rail and slidably engages with the rail;
• a screw assembly including a screw member supported on the slider so as to be rotatable about the first direction;
• an electric motor that is supported on the slider and configured to rotate the screw member;
• and
• a screw engagement portion that is formed on the rail so as to extend in the first direction and engage with the screw member,
• the rail having a pair of side walls that oppose each other,
• wherein the screw engagement portion includes a plurality of engagement holes formed in each side wall and arranged in the first direction, each engagement hole extending at an angle with respect to a second direction perpendicular to the first direction, and
• wherein each engagement hole includes a first portion located in a longitudinally central part thereof and a pair of second portions located on either side of the first portion, the width of the second portion in the first direction being smaller than the width of the first portion in the first direction such that the screw member does not abut against an edge portion of the engagement hole in the first portion, and abuts against the edge portion of the engagement hole in at least one of the second portions,
• the manufacturing method comprising the steps of
• forming the engagement holes in the rail,
• assembling the screw assembly and the electric motor to the slider, and
• assembling the slider, with the screw assembly and the electric motor assembled thereto, to the rail.