Jtekt Corporation

Yu Myohoji

Atsumune Nagatani

Masayoshi Sakuda

Yoshihito Yoshihara

Satoki Yoshimura

Michiaki Yamaoka

Masayuki Nagaoka

Naohiro Oosono

Daiki Goto

Shigeru Morita

Yusuke Nishimine

A column jacket includes a hollow outer jacket having a pair of clamped portions disposed to sandwich a slit between the clamped portions and a tubular inner jacket having, in an area where the inner jacket is fitted in the outer jacket, an elongated hole extending in an axial direction. A clamping mechanism clamps the pair of clamped portions with a pair of side plates of a fixed bracket. The elongated hole is disposed on any one of a first side and a second side, in the lateral direction, of a vertical plane passing through a central axis of the inner jacket, at a position other than on a straight line that extends in a vertical direction through the central axis.

Steering system

There is provided a steering system that can absorb an increased total amount of shock at a time of a secondary collision. A steering member is connected to one end of an upper jacket in a column axial direction. A lower jacket is externally fitted with the other end of the upper jacket in the column axial direction so as to be slidable with respect to the upper jacket. The lower jacket is supported by a support member fixed to a vehicle body. At the time of a secondary collision, a first sliding member generates a first resistive force by performing first relative sliding with respect to the upper jacket, and a second sliding member which is moved together with the first sliding member in the column axial direction generates a second resistive force by performing second relative sliding with respect to the support member and the lower jacket.

Provided is a steering system that is configured to absorb a secondary collision shock load and achieves high vibration rigidity with a simple structure. A lower jacket is externally fitted to an upper jacket in a slidable manner. A support member that supports the lower jacket includes a fixed portion that is fixed to a vehicle body. A shock of a secondary collision is absorbed by a shock absorbing mechanism. The shock absorbing mechanism includes second slide members configured to move together with the upper jacket, and to frictionally slide relative to the support member upon a secondary collision. The second slide member includes a sandwiched portion that is sandwiched between the support member and the lower jacket, and a transmitting portion that is brought into contact with both of the lower jacket and the support member at a position closer to the fixed portion than the sandwiched portion.

A first sliding member is held by an upper jacket. A second sliding member includes a fixed portion fixed to the first sliding member, and an extension portion that extends in a column axis direction and that has a coupled portion coupled to the fixed portion at a predetermined location in the column axis direction. The second sliding member being clamped by the clamping mechanism slides relative to a supporting member and a lower jacket during a secondary impact. The second sliding member includes a slit that reduces coupling stiffness between the fixed portion and the coupled portion of the extension portion so as to facilitate, in a clamping state of the clamping mechanism, deflection of the coupled portion of the extension portion relative to the fixed portion in a lateral direction as seen from the column axis direction.

Steering apparatus

A steering system includes a fastening mechanism that makes an upper jacket fastened to be held by a lower jacket. In a fastened state of the fastening mechanism, a first tooth member on the upper jacket side is meshed with a second tooth member on the lower jacket side. The second tooth member is connected to the lower jacket via a guide shaft (connecting member) that is fracturable during a secondary collision. During the secondary collision in an unfastened state of the fastening mechanism, a second engagement portion (driving member) that moves in a column axial direction integrally with the upper jacket abuts on the second tooth member in an unmeshed state to fracture the guide shaft, and deforms an impact absorbing member via the second tooth member to absorb an impact.

First teeth of a first tooth member that moves together with an upper jacket mesh with second teeth of a second tooth member. The second tooth member includes a received portion received by a receiving surface of a receiving member (energy absorption member). The second tooth member is rotatably supported by a fulcrum that is formed on the receiving surface at a contact position between the receiving surface and the received portion and is movable in a column axis direction. A guide shaft supported by a support member that is supported by a lower jacket is inserted into an elongated hole of the second tooth member, thereby guiding the second tooth member in a meshing and unmeshing direction.

A steering system enabling telescopic adjustment within a predetermined range includes a second tooth member supported by a lower jacket, a damper fixed to an upper jacket so as to face the second tooth member, and an abutting contact member fixed to the lower jacket and coming into abutting contact with the second tooth member from a side opposite from a side where the damper faces the second tooth member. The damper includes an inclined surface that is located at a portion (an end) of the damper, which faces the second tooth member and that is inclined so as to gradually be closer to the upper jacket toward the second tooth member. During telescopic adjustment, the second tooth member comes into abutting contact with the inclined surface of the damper at a sliding limit position.

In a steering system, a pair of first tooth rows that is movable integrally with an upper jacket includes first teeth each of which has a tooth trace extending in an up-down direction Z and which is arranged at a pitch in an axial direction. A tooth member shaped by compression molding includes a pair of second teeth provided on respective side surfaces of a pair of side surfaces of a body portion supported by a lower jacket, the side surfaces extending parallel to each other. The second teeth mesh with the respective first tooth rows in accordance with operation of an operation member that regulates extension and contraction of a column jacket. The second teeth have tooth tips displaced from each other by a distance shorter than a predetermined pitch.

Steering system and tooth member

When telescopic locking is released, a second tooth defining member interlocked with rotation of a clamping shaft via an interlocking mechanism (a driving member and a coupling shaft) acts to separate second teeth of the second tooth defining member from first teeth arranged in a column axial direction. At this time, the second teeth rotate in a circular-arc-like trajectory around a central axis of a support shaft, while the support shaft itself slides through a long groove formed in an outer jacket in the column axial direction. Thus, the movement trajectory of the second teeth during release of meshing engagement is in a direction approximately orthogonal to the column axial direction (the direction in which the first teeth are arranged).

When telescopic locking is released, a second tooth defining member operating in conjunction with rotation of a clamping shaft acts to separate second teeth of the second tooth defining member from first teeth arranged in a column axial direction. At this time, a second portion of the second tooth defining member on which the second teeth are formed is guided by a second guide mechanism in an orthogonal direction orthogonal to the column axial direction to release meshing engagement between the first teeth and the second teeth. A first portion of the second tooth defining member that is supported so as to be rotatable around a support is guided in a column axial direction by a first guide mechanism so as not to hinder operation of the second guide mechanism.

A second tooth defining member includes a first portion rotatably supported around a support so as to be movable in the column axial direction and a second portion defining second teeth coming into meshing engagement with first teeth moving together with an upper jacket. A guide mechanism guides the second portion in an inclination direction inclined with respect to an orthogonal direction orthogonal to the column axial direction. The guide mechanism includes a guide shaft supported by the lower jacket, and a guide hole that is slot formed in the second portion and extending in the inclination direction. The guide hole has a first end and a second end. The second end of the guide hole is arranged farther from the second teeth than the first end and above the first end in the column axial direction.

A steering system includes an engaged member fixed to an upper jacket, an engaging member rotatably supported by a lower jacket, and an impact absorbing member including a movable portion that moves together with the engaging member at the time of a secondary collision, to absorb impact made at the time of the secondary collision. The engaged member has a plurality of engaged teeth. The engaging member comes into engagement with the engaged teeth in accordance with an operation of an operation member. At the time of the secondary collision, the engaging member is disengaged from the lower jacket, and moves along with the upper jacket while in engagement with the engaged teeth.

A steering system includes a second tooth defining member and an energy absorbing unit. The energy absorbing unit includes energy absorbing portions each including a first portion extending upward in a column axial direction from a restraining portion restrained in the column axial direction and a second portion formed by folding back the energy absorbing portion at a fold-back portion, the energy absorbing portions being separated from each other in a first orthogonal direction, and a coupling portion that couples the second portions together and moves together with the second tooth defining member at the time of the secondary collision. At the time of the secondary collision, the energy absorbing portions allow the fold-back portions to move downward in the column axial direction to absorb impact energy while guiding downward movement of the second tooth defining member in the column axial direction between facing edges of the energy absorbing portions.

Growing community of inventors

Habikino, Japan

Yu Myohoji