Abstract:
A rack manufacturing apparatus (100) and a rack manufacturing method are provided. The rack manufacturing apparatus includes a first support portion (110) configured to support a hollow or solid first bar (12A) on which first rack teeth are formed, a second support portion (140) configured to support a hollow or solid second bar (12B) such that an axial center line of the second bar (C2) is aligned with an axial center line of the first bar (C1), a base (20) configured to cause the second support portion (140) to approach the first support portion (110), and a rotary driving portion (130) configured to rotate the second support portion (140) about the axial center line of the second support portion (C2) relative to the first support portion (110) so as to join an end portion of the first bar (12A) and an end portion of the second bar (12B) by a friction pressure welding.
Abstract:
A rack bar (1, 21, 31) includes a shaft member (S1) having a toothed section (2, 12, 22). The toothed section (2, 12, 22) has a plurality of rack teeth (3, 13, 23), and extends over a portion of an entire length of the shaft member (S1) along a longitudinal direction of the shaft member (S1). The shaft member (S1) has a grinding-finished outer peripheral surface extending over the entire length of the shaft member (S1) including the toothed section (2, 12, 22). A method for manufacturing the rack bar (1, 21, 31) includes forming the toothed section (2, 12, 22) by plastic working and grinding the outer peripheral surface to improve shape accuracy.
Abstract:
A hollow rack bar (10) and a method of manufacturing the hollow rack bar are provided. The hollow rack bar (10) includes a hollow blank pipe portion having a uniform wall thickness, and a rack toothed portion. The rack toothed portion includes teeth, a flat portion (33) having a flat surface (35) and arranged side by side with the teeth in a direction along a center axis of the blank pipe portion, and a slanted portion (34) provided at an end of the flat portion (33) with respect to a direction perpendicular to the center axis and arranged to be lower than the flat portion. A length (t1) of the slanted portion (34) projected on a straight line perpendicular to the center axis and parallel to the surface of the flat portion is longer than zero and equal to or shorter than the wall thickness (t) of the blank pipe portion.
Abstract:
A method for manufacturing a rack bar includes joining axial end portions of first and second bar members to each other, and forming a power transmission section on the second bar member. The first bar member has a toothed portion. When the second bar member is hollow, the method may further include thickening a wall of a portion of the second bar member along the axial direction so as to be coaxial with the first bar member. When the second bar member has a greater diameter than the first bar member, the method may further include cutting an outside diameter of a portion of the second bar member in the axial direction so as to be coaxial with the first bar member. The power transmission section is formed on the portion of the second bar member where the wall has been thickened and/or the outside diameter has been cut.
Abstract:
Provided are a method of manufacturing a hollow rack bar including a rack portion that is engaged with a pinion gear and faces supported by a yoke easily and accurately, and the hollow rack bar. The hollow rack bar (10) includes: the rack portion (21) engaged with the pinion gear (29); and the supported faces (23) provided on a back side of teeth of the rack portion (21) and supported by the yoke (31). The rack portion (21) is formed by locating a toothed mold (39) on an outer face of a circular tube material, and inserting a cored bar (41) into the circular tube material to pressurize an inner face, thereby transferring a shape of the toothed mold (39). The supported faces (23) are formed by removal processing or deformation processing of a back side of the teeth rack portion (21) of the circular tube material.
Abstract:
Method of fabricating a rack including: supporting a first rack bar 12A having a first toothed part 12a on a shaft of the first rack bar; supporting a second rack bar 12B having a second toothed part 12b on a shaft of the second rack bar such that an axial center line of the second rack bar coincides with an axial center line of the first rack bar; supporting a joint member 15 between the first and second rack bars such that an axial center line of the joint member coincides with the axial center lines of the first and second rack bars; rotating the joint member 15 about the axial center lines of the first and second rack bars relative to the first and second rack bars; and simultaneously bringing an end of the first rack bar and an end of the second rack bar into friction pressure welding with the joint member.