Steering Device Tilt Lock Gear Buffer Member Noise Reduction

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Solution Overview

Problem

The existing steering devices experience sliding and impact sounds between the movable tilt lock gear and the outer surface of the vehicle body attachment bracket during tilt adjustment, which can be problematic during secondary collisions.

Innovation Solution

Incorporating a buffer member attached to the movable tilt lock gear, which slides on the outer surface of the vehicle body attachment bracket, and made of synthetic resin to reduce these sounds, along with a stationary tilt lock gear and a rotating movable tilt lock gear that engages with it, to enhance retention force and silence the sliding and impact noises.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a movable tilt lock gear is used to engage with a stationary tilt lock gear for improving retention force during tilt adjustment, then the retention force in the tilt direction is improved, but sliding sound and impact sound occur between the movable tilt lock gear and the vehicle body attachment bracket

Engineering Contradiction:
Improveretention forceVSAvoidsliding sound and impact sound
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

A buffer member made of synthetic resin is introduced as an intermediary between the movable tilt lock gear and the vehicle body attachment bracket. This buffer member contacts the outer surface of the side plate during sliding, replacing direct metal-to-metal contact and thereby eliminating sliding sounds and impact sounds while maintaining the locking function.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The buffer member is made of synthetic resin material instead of metal, creating a composite material solution. This synthetic resin material provides both noise reduction (by preventing metal contact) and functional performance (by maintaining engagement and retention force during tilt adjustment).

Inventive Principle:
Principle #40Composite materials

Data Source

PatentEP2597012B1Steering device
Publication Date: 2020.07.01 NSK LTD
  • EP2597012B1 patent drawingFigure 1
  • EP2597012B1 patent drawingFigure 2
  • EP2597012B1 patent drawingFigure 3

AI summary

There is provided a steering device that can reduce a sliding sound and an impact sound between a movable tilt lock gear and an outer surface of a side plate of a vehicle body attachment bracket. When a movable tilt lock gear 6 is rotated, and a thread of an inclined cam surface 82 of a stationary cam 8 runs on a thread of an inclined cam surface of a movable cam 42, a fastening rod 41 is pulled toward a left side, and the movable tilt lock gear 6 is pushed toward an outer surface 241 of a left side plate 24. Because a first buffer member 71 and a second buffer member 72 are attached to the movable tilt lock gear 6, sliding surfaces 711 and 712 of the first buffer member 71 and a sliding surface 721 of the second buffer member 72 contact the outer surface 241 of the left side plate 24, and slide, to suppress the sliding sound.