Jtekt Corporation

Hidenobu Tanaka

Masayuki Nagaoka

Hiromitsu Tomiyama

Atsumune Nagatani

Yoshihito Yoshihara

Yuji Takahashi

Shoji Ishimura

Kenichi Aota

A steering system that is telescopically extendable and retractable using a motor driving force includes a motor, a telescopic steering shaft, a tube that supports the steering shaft such that the steering shaft is rotatable and that is movable with telescopic movement of the steering shaft, and a driving force transmission device that transmits a rotational driving force of the motor to the tube. The driving force transmission device includes a driving force converter that converts the rotational driving force of the motor to a linear driving force, and a coupling member that couples the driving force converter to the tube. The coupling member is breakable by an impact force applied thereto through the steering shaft and the supporting member during a secondary collision so as to decouple the driving force converter from the tube.

Steering system

A steering system that is telescopically extendable and retractable using a motor driving force includes a motor, a telescopic steering shaft, a tube that supports the steering shaft such that the steering shaft is rotatable and that is movable with telescopic movement of the steering shaft, an energy absorbing member connected to the tube, and a movable member connected to the energy absorbing member and configured to move the tube by being moved by a driving force of the motor. The energy absorbing member has a stiffness that moves the tube by transmitting the driving force of the motor from the movable member to the tube. The energy absorbing member is deformable to absorb impact energy that is applied to the energy absorbing member through the steering shaft and the tube during a secondary collision.

A steering system includes a movable member and a tooth member. The movable member includes first tooth arrangements. The movable member is movable together with a column jacket in a tilt direction. The movable member is movable in a right-left direction. The tooth member is supported by a lateral plate of an upper bracket so that the tooth member is located between the movable member and the lateral plate in the right-left direction. The tooth member includes: second tooth arrangements engageable with the first tooth arrangements; and curved elastic portions supporting the second tooth arrangements, with the second tooth arrangements inclined toward the upper bracket such that the second tooth arrangements are away from the first tooth arrangements. When the elastic portions are sandwiched between the movable member and the lateral plate and elastically deformed, the second tooth arrangements come into engagement with the first tooth arrangements.

A column jacket can pivot in a tilt direction around an end of a steering shaft along with the steering shaft. When the column jacket is pivoted in the tilt direction, an engaging member moves in the tilt direction along with the column jacket. A position fixing mechanism has a pair of fixing members located adjacent to opposite ends of an engaged member in a longitudinal direction to fix the position of the engaged member in the tilt direction. The position fixing mechanism fixes the position of the column jacket in the tilt direction by engaging the engaged member with the engaging member. At a time of a secondary collision, the engaged member engaged with the engaging member breaks a front fixing member.

A steering system includes an insertion shaft that is movable in a tilt direction C along with a column jacket, a first tooth member including a plurality of first teeth aligned along a first linear direction, and a second tooth member including a plurality of second teeth aligned along the first linear direction. A first restriction portion restricts movement of the first tooth member in the first linear direction with respect to an upper bracket. A second restriction portion is movable in the first linear direction and immovable in a second linear direction, with respect to a linear slot in the first tooth member that extends along the first linear direction. The second restriction portion restricts movement of the second tooth member in the second linear direction with respect to the first tooth member.

In a steering system, a pair of side plates of an upper bracket support first tooth rows each including a plurality of first teeth arranged at a pitch and second tooth rows each including a plurality of second teeth arranged at the pitch. An insertion shaft supports third teeth that can come into and out of contact with the first tooth rows and fourth teeth that can come into and out of contact with the second tooth rows. One pair out of a pair of the tooth tip of each first tooth and the tooth tip of the corresponding second tooth and a pair of the tooth tip of each third tooth and the tooth tip of the corresponding fourth tooth are in the same position in a tilt direction, and the other pair are displaced from each other by a length smaller than the pitch in the tilt direction.

A steering system includes a lock mechanism and a releasing member. The lock mechanism includes a clamping shaft inserted through insertion holes in side plates, an operation lever that rotationally operates the clamping shaft, a rotational cam coupled to the clamping shaft so as to be rotatable integrally therewith and movable integrally therewith in an axial direction, a first clamping member that moves the rotational cam in the axial direction with respect to the side plates, and a stopper that restricts a rotation range of the clamping shaft. The releasing member includes a fitting portion located between the side plates and fitted on an outer peripheral surface of the clamping shaft so as to provide a clamping margin, and frictionally slides the fitting portion in the axial direction with respect to the clamping shaft when the rotational cam moves in the axial direction with respect to the side plates.

A steering system includes: a first tooth member provided with a first tooth row that includes a plurality of first teeth each of which has a tooth trace extending in a lateral direction and which are aligned along a tilt direction, the first tooth row being elastically deformable in the lateral direction, and a second tooth member including a second tooth row that includes a plurality of second teeth each of which has a tooth trace extending in the lateral direction and which are aligned along the tilt direction, the second tooth member facing the first tooth member in the lateral direction. The first tooth member is supported by an upper bracket such that the first tooth row is disposed away from the upper bracket in the lateral direction. The second tooth member is movable in the tilt direction along with a column jacket.

A steering system includes: an upper bracket that supports a column jacket so that the column jacket is pivotable about a central shaft; a pair of first tooth rows that are supported by the upper bracket and are arranged side by side in an axial direction; and a tooth member that is pivotable together with the column jacket and is movable in a right-and-left direction. The tooth member has second teeth that are formed in two locations spaced apart from each other in the axial direction and that can mesh with the pair of the first tooth rows. The tooth tip angle of first teeth in one first tooth row of the pair of the first tooth rows is different from the tooth tip angle of the first teeth in the other first tooth row that is more distant from the central shaft than the one first tooth row.

A steering system includes an upper bracket having a first tooth row, a rigid tooth member, a second tooth row provided on the tooth member, a first moving member, and an elastic member disposed between the tooth member and the first moving member. The first tooth row includes a plurality of first teeth. The second tooth row includes a plurality of second teeth. The elastic member exerts a constant restoration force. The second tooth row meshes with the first tooth row when the first teeth and the second teeth are alternately arranged in a tilt direction.

A lock device of a steering system includes a tongue piece unit and a frame plate held on a first side plate. The tongue piece unit includes elastic tongue pieces supported in a cantilever manner by a vertical frame provided along at least one of longitudinal edge portions of at least one of first side plates to form a row that extends in a tilt direction. The frame plate includes partitioning portions, between which a plurality of grooves are formed to house the elastic tongue pieces so as to be projectable. When a steering column is locked, some of the elastic tongue pieces are pressed by a pressing surface of a tightening member to be retracted into grooves. Consequently, the tightening member is interposed between the elastic tongue pieces projecting from the grooves in the tilt direction.

In a steering system configured such that occurrence of a half lock is suppressed, when a body portion of a tooth member is pressed in a lock operation of locking the position of a steering column, the tooth member is extended to move a pair of second tooth row forming portions away from each other obliquely with respect to a lateral direction of an elongate tilt hole along the outer surface of a fastening side plate.

Growing community of inventors

Shiki-gun, Japan

Hidenobu Tanaka