FASTENING STRUCTURE FOR SELF-TAPPING SCREW AND STRUCTURE OF PUSH ROD OF BRAKE APPLYING CYLINDER IN BRAKE DEVICE OF VEHICLE USING THE TAPPING SCREW FASTENING STRUCTURE

摘要

PROBLEM TO BE SOLVED: To provide a slackening preventive structure of a self-tapping screw fastening structure equipped with a strengthened slackening preventive structure applicable favorably in a fastening structure for an object whereto impacts are applied with the time.;SOLUTION: The slackening preventive structure for a self-tapping screw has such an engaging structure that engagement is generated while male threads 7 of the screw makes tapping of female threads 3 at the inside wall of a glide hole 2, and has a glide shaft part 14 protruding onto the shaft from the tip of a screw shaft part 13 on which the male threads 7 are formed, wherein the outside diameter R1 of the glide shaft part 14 is made slightly greater than the outside diameter R2 of the bottoms of the male threads 7 and the inside diameter 3 of the crests 3 of the female threads 3 formed by tapping, and prevention of the screw from slackening is established by abutting the glide shaft part 14 to the female threads 3 existing closely owing to the diametric difference t.;COPYRIGHT: (C)2004,JPO