Steering Wheel Horn Switch Guide Pin Dynamics

Solution Overview

Problem

The existing steering wheel designs require additional space for the horn switch due to the protrusion of the guide pin when the airbag module interferes with it during horn operation, which increases the force needed to ring the horn and reduces vibration damping.

Innovation Solution

A steering wheel design where the guide pin is axially slidably connected to the core metal and locked to the airbag module, featuring a stopper with a flange portion and a damper to transmit loads and adjust vibration frequency, eliminating the need for movable and fixed horn plates and allowing the guide pin to remain within the core metal without protruding towards the airbag module.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the guide pin is fixed to the core metal and the airbag module is slid along the guide pin, then the horn switch can be provided, but the guide pin protrudes toward the airbag module side when the horn is operated, requiring additional space and increasing the force needed to ring the horn

Engineering Contradiction:

Improvehorn switch functionalityVSAvoidforce required to ring the horn

Core Design Contradiction:

ReliabilityVSForce

Solution Approach 1:

The patent inverts the traditional horn switch structure by making the guide pin movable relative to the core metal instead of fixed. The guide pin is now connected to the core metal via a movable connection that allows it to retract when the airbag module is pushed down during horn operation, eliminating the protrusion problem and reducing the force required to ring the horn.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent applies dynamics by transforming the static guide pin into a dynamic component that can move relative to the core metal. The guide pin is equipped with a movable connection mechanism that enables it to adjust its position during horn operation, allowing it to retract when the airbag module is pushed down, thereby eliminating interference and reducing operating force.

Inventive Principle:

Principle #15Dynamics

2Device complexity

If the guide pin protrudes toward the airbag module side during horn operation, then the horn switch structure is maintained, but a large force is required to ring the horn and the vibration damping effect is reduced

Engineering Contradiction:

Improvehorn switch structureVSAvoidvibration damping effect

Core Design Contradiction:

Device complexityVSLoss of energy

Solution Approach 1:

The patent applies dynamics by transforming the static guide pin into a dynamic component that can move relative to the core metal. The guide pin is equipped with a movable connection mechanism that enables it to adjust its position during horn operation, allowing it to retract when the airbag module is pushed down, thereby eliminating interference and reducing operating force.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent introduces a movable connection mechanism as an intermediary between the guide pin and the core metal. This intermediary allows the guide pin to move independently, retracting during horn operation to eliminate interference with the airbag module, thereby reducing the force required and improving vibration damping without complicating the overall structure.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If space is secured for the guide pin protrusion, then the horn switch can operate, but the available space in the narrow central part of the steering wheel is further reduced

Engineering Contradiction:

Improvehorn switch operationVSAvoidavailable space in steering wheel

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The patent applies dynamics by transforming the static guide pin into a dynamic component that can move relative to the core metal. The guide pin is equipped with a movable connection mechanism that enables it to adjust its position during horn operation, allowing it to retract when the airbag module is pushed down, thereby eliminating interference and reducing operating force.

Inventive Principle:

Principle #15Dynamics

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

This design saves space for the horn switch while maintaining its functionality by ensuring reliable load transmission and adjusting vibration frequency, reducing the required force to operate the horn and enhancing vibration damping.

Implementation Method 1

a damper that is provided in a space between the second end portion and the flange portion and is locked to an inner edge of the second opening

Methodology Applied

Scientific EffectVibration damping: Damping

Implementation Method 2

a horn spring provided between the flange portion and the core metal

Methodology Applied

Scientific EffectElastic potential energy storage and release: Spring

Data Source

PatentUS11351915B2Steering wheel

Publication Date: 2022.06.07 JOYSON SAFETY SYST JAPAN KK

AI summary

Provided are a horn switch and steering wheel capable of reducing a space for the horn switch. A horn switch 4 includes: a guide pin 41 provided with a first end part 411 axially slidably connected to a first opening 211 of a core metal 2, and a second end part 412 disposed to be locked to a second opening 322 of an airbag module 3; a stopper 42 provided with a flange part 421 fixed to the shaft part of the guide pin 41; a damper 43 disposed in a space between the second end part 412 and the flange part 421 and locked to the inner edge of the second opening 322; a horn spring 45 disposed between the flange part 421 and the core metal 2; a fixed-side contact 46 disposed in the core metal 2; and a movable-side contact 47 disposed in the airbag module 3.