Steer-by-Wire Steering Mechanism With Mechanical End-Stop Reaction

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Solution Overview

Problem

Steer by wire type steering apparatuses lack mechanical connection between the steering wheel and wheels, leading to indefinite rotation of the steering wheel, reduced driver's steering feeling, and decreased stability, especially when a motor or electronic controller malfunctions.

Innovation Solution

A steer by wire type steering apparatus with a screw shaft, moving member, housing, and guide member that mechanically restricts the steering wheel rotation at maximum point and generates a physical steering reaction force using support members even in the event of a motor or electronic controller malfunction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a steer by wire type steering apparatus is used to eliminate mechanical connection between steering wheel and wheels, then convenience in steering operation is improved, but steering wheel can rotate indefinitely and driver's steering feeling and stability are reduced

Engineering Contradiction:

Improvesteering operation convenienceVSAvoidsteering stability

Core Design Contradiction:

Ease of operationVSStability of the object's composition

Solution Approach 1:

The steering system is divided into independent segments: the steering wheel with motor becomes one module, and the wheels become another module, connected through electronic control rather than direct mechanical linkage. This segmentation enables independent control of each component while maintaining overall system functionality.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

An electronic controller acts as an intermediary between the steering wheel motor and the wheel motors. The controller receives steering input signals, processes them according to vehicle conditions, and generates appropriate commands for the wheel motors, thereby mediating the steering action without direct mechanical connection.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Extent of automation

If motor or electronic controller malfunctions in steer by wire system, then automation is improved, but steering reaction force cannot be generated and driver's steering feel deteriorates

Engineering Contradiction:

Improveelectronic steering controlVSAvoidsteering reaction force generation

Core Design Contradiction:

Extent of automationVSReliability

Solution Approach 1:

The system incorporates redundant mechanical reaction force generation mechanisms that are prepared in advance. When electronic control malfunctions, these pre-configured mechanical pathways (such as emergency steering mechanisms or alternative force feedback paths) automatically activate to maintain steering functionality and driver awareness.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The system dynamically changes operational parameters based on system status. When electronic control is functional, normal electric steering parameters are used. When malfunction is detected, the system switches to emergency steering parameters that rely on mechanical reaction forces, thereby adapting to the changed conditions and maintaining reliability.

Inventive Principle:

Principle #35Parameter changes

3Stability of the object's composition

If steering wheel rotation is mechanically restricted at maximum point, then steering stability is improved, but device complexity increases due to additional mechanical components

Engineering Contradiction:

Improvesteering stabilityVSAvoidmechanical structure complexity

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The motor that drives the wheels also serves dual functions: it acts as the primary steering actuator during normal operation and simultaneously functions as a reaction force generator during emergency conditions. This multi-functionality reduces the need for separate dedicated components for each function.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system uses its own motor and control systems to provide steering reaction force feedback to the driver, rather than requiring separate dedicated reaction force generation mechanisms. The motor controller can generate electrical torque that mimics mechanical reaction forces, allowing the system to serve its own steering feedback needs.

Inventive Principle:

Principle #25Self-service

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enhances driver's steering feel and stability by preventing further rotation of the steering wheel and providing a physical reaction force, ensuring safe steering even in the presence of malfunctions.

Implementation Method 1

a screw shaft having an outer circumferential screw portion provided on an outer circumferential surface and rotating in conjunction with the steering shaft, a moving member coupled to an outer circumferential side of the screw shaft and having an inner circumferential screw portion screw-coupled to the outer circumferential screw portion

Methodology Applied

Scientific EffectScrew mechanism: Screw

Data Source

PatentUS12454305B2Steer by wire type steering apparatus

Publication Date: 2025.10.28 HL MANDO CORP

AI summary

The present embodiments may provide a steer by wire type steering apparatus including a screw shaft rotating in conjunction with the steering shaft, a moving member coupled to an outer circumferential side of the screw shaft and moving in the axial direction when the screw shaft rotates, a housing in which the screw shaft and the moving member are embedded, and a guide member coupled to the housing to support the moving member and guide the axial movement of the moving member.