SHOCK-ABSORPTION TYPE VEHICULAR STEERING DEVICE, AND METHOD OF MANUFACTURING TUBE FOR THE SAME

PROBLEM TO BE SOLVED: To provide a shock-absorption type vehicular steering device having a large shock absorbing stroke. SOLUTION: An intermediate shaft 5 of this shock-absorption type vehicular steering device is connected to a steering shaft 3 through a first universal joint 4, and connected to an input shaft of a steering gear 11 through a second universal joint 6. The intermediate shaft 5 includes a first and a second cylinders 38 and 39, and a bellows portion 40 having convexes 41 and concaves 42 alternately. In a shrunken-diameter range 45 of the bellows portion 40 in the circumferential direction T, the top 43 of the convex 41 is formed with a flat plate part 51 extended in parallel with the axis C0 of the intermediate shaft 5. The depth H1 from the top 43 of the convex 41 to the bottom 44 of the concave 42 in the shrunken-diameter range 45 is formed smaller than the depth H2 from the top 43 of the convex 41 to the bottom 44 of the concave 43 in the non-shrunken-diameter range 46. The bellows portion 40 is bent and contracts when absorbing a shock. COPYRIGHT: (C)2009,JPO&INPIT