Neturen Co., Ltd.

Takashi Yamawaki

Takashi Kato

Tsuyoshi Yamamoto

Ryosuke Suzuki

Makoto Nomura

Yutaka Kiyosawa

Tetsuji Murata

Nobumoto Ishiki

Kenichi Aoki

Toshifumi Uemoto

Takuya Nakamizo

Norimasa Sunaga

A manufacturing method is provided for a hollow rack bar made of a hollow shaft material and including a toothed section which has a rack on an outer surface and a shaft section which is thinner than the toothed section. The manufacturing method includes: (i) drawing the hollow shaft material using a die and a plug, and preforming regions of the hollow shaft material including a toothed section formation region configured to become the toothed section and a shaft section formation region configured to become the shaft section so as to have thicknesses according to the respective regions; and (ii) forming the rack at the toothed section formation region of the hollow shaft material which is preformed.

Manufacturing method for hollow rack bar and hollow rack bar manufacturing apparatus

A method of fabricating a rack, the method includes: supporting a first rack bar having a first toothed part on a shaft of the first rack bar; supporting a second rack bar having a second toothed part 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 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 about the axial center lines of the first and second rack bars relative to the first and second rack bars; and bringing an end of the first rack bar and an end of the second rack bar into friction pressure welding with the joint member.

Method for manufacturing rack and hollow rack bar

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.

Method for manufacturing rack bar

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 () includes: the rack portion () engaged with the pinion gear (); and the supported faces () provided on a back side of teeth of the rack portion () and supported by the yoke (). The rack portion () is formed by locating a toothed mold () on an outer face of a circular tube material, and inserting a cored bar () into the circular tube material to pressurize an inner face, thereby transferring a shape of the toothed mold (). The supported faces () are formed by removal processing or deformation processing of a back side of the teeth rack portion () of the circular tube material.

Hollow rack bar and method of manufacturing the hollow rack bar

A rack bar includes a shaft portion and a rack toothed portion provided on the shaft portion. The rack toothed portion includes a plurality of rack teeth provided side by side in an axial direction of the shaft portion to mesh with a pinion gear. Each of the rack teeth includes a tooth tip portion, a contact face arranged obliquely relative to the axial direction and configured to contact the pinion gear, and a rounded corner portion between the tooth tip portion and the contact face. A first radius defining a central area of the rounded corner portion with respect to a tooth width direction is larger than a second radius defining another area of the rounded corner portion other than the central area.

Rack bar and rack bar teeth forming die

A hollow rack bar and a method of manufacturing the hollow rack bar are provided. The hollow rack bar 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 having a flat surface and arranged side by side with the teeth in a direction along a center axis of the blank pipe portion, and a slanted portion provided at an end of the flat portion with respect to a direction perpendicular to the center axis and arranged to be lower than the flat portion. A length of the slanted portion 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 of the blank pipe portion.

Hollow rack bar and method of manufacturing hollow rack bar

A rack bar includes a shaft portion, a rack toothed portion provided on the shaft portion, and a dummy toothed portion. The rack toothed portion includes a plurality of rack teeth provided side by side in an axial direction of the shaft portion, each of the rack teeth including a contact face arranged obliquely relative to the axial direction to contact the pinion gear. The dummy toothed portion includes at least one dummy tooth provided on at least one side of the rack toothed portion in the axial direction such that the dummy tooth is arranged parallel to and next to the rack teeth. The dummy tooth is designed such that a whole height of the dummy tooth is smaller than a whole height of each of the rack teeth.

The present invention includes a bar having a maximum cross section region smaller than a minimum cross section region of a hollow portion of a pipe P, and projected portions mounted along an axial direction of the bar and including a projected portion with maximum extent Hb, extent Ha of the projected portion positioned at a leading end side of the bar is set to be smaller than extent Hb of the projected portion positioned at a center side in the axial direction, and extent Hc of the projected portion positioned at a base end side of the bar is set to be less than or equal to extent Hb of the projected portion.

Mandrel, set of mandrels, and hollow rack bar

With a first push rod which is to be inserted/removed into/from a steel pipe through an opening at one end and a second push rod which is to be inserted/removed into/from the steel pipe through an opening at the other end, a metal core disposed on a side on which the first push rod is inserted/removed into/from the die assembly is sandwiched and this metal core is stopped from rotating with the first push rod. With the state of stopping the rotation of the first push rod, the metal core is introduced into the steel pipe through the opening at the one end by both the push rods. After the metal core is pressed into the steel pipe while stopped from rotating with the first push rod, this metal core is pushed back by the second push rod.

Hollow rack manufacturing method and manufacturing apparatus

The one end side portion is nipped by a jig including a jig member having a pair of convex portions which are to be fitted to a depressions in contact with a tooth side face and a inclined portion and positioning a bar and a jig member which is to be clamped/opened with respect to the jig member. A die having an inside diameter smaller than the diameter of the outer periphery is pressed onto the outer periphery of the end portion of the cylindrical end side portion projected from the jig up to a press-in depth determined preliminarily based on the rack, so as to reduce the diameter of the end portion.

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Tokyo, Japan

Takashi Yamawaki