STEERING COLUMN APPARATUS

• US 20140251061A1
• Filed: 10/24/2012
• Published: 09/11/2014
• Est. Priority Date: 12/02/2011
• Status: Active Grant

• Current Assignee: NSK Limited
• Original Assignee: NSK Limited
• Inventors: Moriyama, Seiichi
• Granted Patent: US 8,960,721 B2
• Time in Patent Office: Days
• US Class Current: 74/493
• CPC Class Codes: B62D 1/184 Mechanisms for locking columns at selected positions
• CPC Class Codes: B62D 1/187 with tilt adjustment; with tilt and axial adjustment B62D1/183, B62D1/19 takes precedence
• CPC Class Codes: B62D 1/195 Yieldable supports for the steering column

Abstract

Construction of a steering column apparatus used in a tilt steering apparatus is achieved that is capable of reducing impact applied to the driver'"'"'s body even when an adjustment rod is forcibly pressed against the front edges of long holes in the up-down direction during a secondary collision. Through holes that are continuous along the long holes in the up-down direction from the top end portion to the bottom end portion of the long holes in the up-down direction, and are formed in portions of a pair of left and right support plate portions of the support bracket that are further toward the front side than the long holes in the up-down direction. Bridge portions are provided between the front side edges of the long holes in the up-down direction and the rear side edges of the through holes. The bridge portions reduce impact by plastically deforming in the forward direction due to an impact load that is applied in the forward direction from the steering column by way of the adjustment rod during a collision accident.

Claims

1. A steering column apparatus, comprising:

a steering column having a means supporting a steering shaft so as to rotate freely in a state where the steering shaft which fixes and supports a steering wheel at a rear end portion thereof is inserted in an axial direction through the steering column, and a front end portion that is supported by a portion fastened to a vehicle body so as to be able to pivotally displace around a pivot shaft that is arranged in a width direction;

a displacement bracket fastened to a middle portion in the axial direction of the steering column;

a through hole formed so as to pass through the displacement bracket in the width direction;

a support bracket having a pair of support plate portions, and being supported by the vehicle body with the support plate portions arranged on left and right sides of the displacement bracket;

long holes in an up-down direction provided in portions of the pair of support plate portions that are aligned with the through hole;

an expansion/contraction apparatus having;

an adjustment rod that is inserted through the long holes in the up-down direction and the through hole, a pair of pressure portions that are provided in portions of the adjustment rod located on both sides of the support plate portions in the width direction, and a mechanism that expands or contracts a space between the pressure portions according to operation of an adjustment lever that is provided on one end portion of the adjustment rod that protrudes from an outside surface of one of the support plate portions;

through holes formed in portions of the pair of support plate portions further on the front side than the long holes in the up-down direction, and being continuous along the long holes in the up-down direction from a top end portion to a bottom end portion of the long holes in the up-down direction, and having a dimension in the up-down direction that is equal to or greater than the dimension in the up-down direction of the long holes in the up-down direction; and

bridge portions provided between front side edges of the long holes in the up-down direction and rear side edges of the through holes, and being able to plastically deform due to an impact load that is applied from the steering column in a forward direction by way of the adjustment rod during a collision accident.

2. The steering column apparatus according to claim 1, wherein

cut out portions having a width dimension that is less than an outer diameter of the adjustment rod are formed on both end portions in the up-down direction of the long holes in the up-down direction so as to protrude upward and downward from the both end portions in the up-down direction of the long holes in the up-down direction.

3. The steering column apparatus according to claim 1, wherein

rear side edges of the through holes are parallel with front side edges of the long holes in the up-down direction, and a width dimension in a forward-backward direction of the through holes becomes wider in a downward direction.

4. The steering column apparatus according to claim 1, wherein

the long holes in the up-down direction are constructed by long holes that have a partial arc shape around the pivot shaft, or extend in a tangential direction to the partial arc.

5. The steering column apparatus according to claim 1, wherein

the long holes in the up-down direction are formed so as to be inclined at a specified angle with respect to a virtual plane that is orthogonal to a center axis of the steering column so as to extend downward in the forward direction, and regardless of an up-down position of the steering wheel, the specified angle is larger than the inclination angle of the center axis of the steering column with respect to the forward-backward direction.

6. The steering column apparatus according to claim 3, wherein

an inclination angle of front end edges of the through holes with respect to a virtual plane that is orthogonal to the center axis of the steering column, is greater than an inclination angle of the center axis of the steering column with respect to a forward-backward direction regardless of an up-down position of the steering wheel.

7. The steering column apparatus according to claim 1, wherein

the expansion/contraction apparatus includes the adjustment lever that is rotatably provided on the one end portion of the adjustment rod, and the pair of pressure portions are constructed by a driven cam that fits around a portion near the one end in a middle portion of the adjustment rod, and a large diameter portion on other end side of the adjustment rod that is provided in a state such that displacement in a direction going away from the support plates is prevented;

the driven cam engages in one of the long holes in the up-down direction so as to be able to displace only along the one long hole in the up-down direction;

a base end portion of the adjustment lever is connected to the one end portion of the adjustment rod such that displacement of the base end portion of the adjustment lever in a direction going away from the driven cam is prevented by a large diameter portion on one end side that is provided on the one end portion of the adjustment rod;

the mechanism that expands or contracts the space between the pressure portions is provided on the base end portion of the adjustment lever and is constructed by a cam apparatus that comprises a driven cam and a driving cam that pivotally displaces together with the adjustment lever, and by pivotally displacing the adjustment lever in a specified direction, a dimension in an axial direction of the cam apparatus is reduced, and the space between the pressure portions is expanded, and by pivotally displacing the adjustment lever in a direction opposite to the specified direction, the dimension in the axial direction of the cam apparatus is expanded, and thus the space between the pressure portions is contracted; and

a long hole on a driven side that extends in the forward-backward direction is provided in a center portion of the driven cam;

a long hole on a driving side that extends in the forward-backward direction in a state where the dimension in the axial direction of the cam apparatus is expanded by pivotally displacing the adjustment lever in a direction opposite the specified direction and the steering wheel is maintained in the adjusted position in the up-down direction, is provided in a center portion of the driving cam;

a long hole on the other end side that extends in the forward-backward direction is provided in a center portion of the large diameter portion on the other end side; and

the adjustment rod is inserted through the long hole on the driven side, the long hole on the driving side, and the long hole on the other end side.