Steering Column Lock Camwheel Variable Radius Profile

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Solution Overview

Problem

Existing electrical steering column lock devices for automotive vehicles lack an effective mechanism to control the mechanical relationship between parts, particularly during disengagement, resulting in inconsistent unlocking forces and torques.

Innovation Solution

A steering column lock device featuring a camwheel with circular contact surfaces of varying radii and slopes, allowing for precise control of the lockbolt's position and reaction torque, enabling variable unlocking forces and speeds through a series of cam profiles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a camwheel with variable radius circular contact surfaces is used, then the control precision of contact point position is improved, but the device complexity increases

Engineering Contradiction:
Improvecontact point position controlVSAvoidcamwheel structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The camwheel features circular contact surfaces with locally variable radii, where each contact surface has a specific radius value that differs from others. This local variation in geometric property allows precise control of the contact point position on the lockbolt without requiring complex additional control mechanisms, thus resolving the contradiction between measurement precision and device complexity.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention uses circular contact surfaces with variable radii on the camwheel, replacing traditional flat or uniformly curved surfaces. This curvature variation enables accurate positioning of the contact point while maintaining a relatively simple camwheel structure, addressing the contradiction between control precision and structural complexity.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Adaptability or versatility

If multiple cam profiles with different slopes are used, then the adaptability of unlocking force is improved, but the manufacturing precision requirements increase

Engineering Contradiction:
Improveunlocking forceVSAvoidcam profile geometry
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The camwheel incorporates multiple cam profiles, each with a specific slope value, allowing the unlocking force to be adapted to different conditions. Each profile's local geometric property (slope) is optimized for specific operational requirements, enabling force adaptability while using standard manufacturing processes for creating the profiles.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention varies the slope parameter of different cam profiles to achieve different unlocking force characteristics. By changing this geometric parameter across multiple profiles rather than using a single complex variable geometry, the system achieves adaptability with manageable manufacturing precision requirements.

Inventive Principle:
Principle #35Parameter changes

3Force

If the contact member cooperates with variable radius circular contact surface, then the force control is improved, but the ease of manufacture decreases

Engineering Contradiction:
Improveunlocking forceVSAvoidcamwheel fabrication
Core Design Contradiction:
ForceVSEase of manufacture

Solution Approach 1:

The use of circular contact surfaces with variable radii on the camwheel provides improved force control through geometric leverage while maintaining manufacturability. Circular arcs are relatively easy to manufacture compared to complex asymmetric curves, and the variable radius can be achieved through standard machining or forming processes, thus balancing force control improvement with ease of manufacture.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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

The solution provides accurate control over the unlocking process, adapting the steering column lock's operation by varying the unlocking force and speed, enhancing the mechanical relationship between the lockbolt and camwheel, thereby improving the locking and unlocking mechanisms.

Implementation Method 1

a camwheel movable in rotation around a rotation axis, the camwheel comprising at least one cam profile having a circular contact surface, the circular contact surface having a variable radius with respect to the rotational axis of the camwheel

Methodology Applied
Scientific EffectMechanical Advantage: Mechanical Advantage

Data Source

PatentEP3419865B1A steering column lock device for an automotive vehicle
Publication Date: 2019.11.13 U SHIN DEUTSCHLAND ZUGANGSSYSTEME GMBH
  • EP3419865B1 patent drawingFigure 1~2
  • EP3419865B1 patent drawingFigure 3~4

AI summary

The invention relates to a steering column lock device for an automotive vehicle comprising: - a lockbolt having a contact member, the lockbolt being configured to be driven between an engaged position in which the lockbolt locks a steering column, and a disengaged position in which the lockbolt releases the steering column, - a camwheel (3) movable in rotation around a rotation axis (30), the camwheel (3) comprising at least one cam profile having a circular contact surface (32), the circular contact surface (32) having a variable radius (Rl, R2) with respect to the rotational axis (30) of the camwheel (3), wherein the contact member is configured to cooperate with the circular contact surface (32) such that when the lockbolt is driven between the engaged position and the disengaged position by the rotation of the camwheel (3). The invention further relates to an electrical steering column lock for an automotive vehicle and to an automotive vehicle comprising the electrical steering column lock of the invention.