Vehicle Suspension Spring Pad Layout to Prevent Coil Spring Separation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In vehicles tuned for high handling performance and reduced weight, the spring connecting the suspension arm to the body member separates during full rebound, risking accidents like rollovers due to reduced spring compression and increased wheel stroke.

Innovation Solution

A suspension system with a leaf spring and spring pad configuration that supports the coil spring's lower end, using a leaf spring and spring pad to prevent separation during full rebound, ensuring continuous support and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the hardness of the spring is increased to tune the vehicle hard, then the wheel rate is improved, but the amount of compression of the spring is reduced

Engineering Contradiction:
Improvespring hardnessVSAvoidspring compression amount
Core Design Contradiction:
StrengthVSLength of moving object

Solution Approach 1:

The suspension system is divided into two independent spring components: a coil spring for primary suspension and a leaf spring as a secondary support. This segmentation allows each spring to have optimized characteristics - the coil spring provides the main elastic support while the leaf spring acts as a backup to prevent separation during full rebound, resolving the contradiction between spring hardness and compression amount.

Inventive Principle:
Principle #1Segmentation

2Weight of moving object

If the vehicle weight is lightened to meet eco-friendly trends, then the vehicle weight is reduced, but the force compressing the spring is reduced and the amount of compression is reduced

Engineering Contradiction:
Improvevehicle weightVSAvoidspring compression amount
Core Design Contradiction:
Weight of moving objectVSLength of moving object

Solution Approach 1:

By segmenting the suspension into a primary coil spring and a secondary leaf spring, the system compensates for reduced compression force from lightweight vehicles. The leaf spring is designed with lower stiffness to engage only when the coil spring is fully compressed, providing additional support during full rebound conditions without affecting normal suspension operation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The leaf spring is designed with specific parameter characteristics - lower stiffness compared to the coil spring, and a specific installation position that creates initial tension. These parameter changes allow the leaf spring to remain inactive during normal operation but activate when the coil spring reaches full compression, preventing separation in lightweight vehicles.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the wheel stroke is reduced to prevent spring separation, then the spring separation is prevented, but the vehicle performance and merchantability are affected

Engineering Contradiction:
Improvespring separation preventionVSAvoidvehicle performance
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The leaf spring is pre-installed with initial tension between the suspension arm and body member before any rebound motion occurs. This preliminary action ensures that when the coil spring reaches full compression during extreme rebound, the leaf spring is already positioned to immediately engage and prevent separation, without requiring reduction of wheel stroke.

Inventive Principle:
Principle #10Preliminary action

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

Prevents coil spring separation, enhancing vehicle stability and maintaining ride comfort by securing rebound stroke and preventing accidents.

Implementation Method 1

a rod portion extended from the coupled portion along a longitudinal direction of the suspension arm and configured to be elastically deformed in response to external force

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

a coil spring provided to be supported, at opposite ends of the coil spring, by a body member and the spring pad

Methodology Applied
Scientific EffectSpring elasticity: Spring

Implementation Method 3

a spring pad coupled to the leaf spring; and a coil spring provided to be supported, at opposite ends of the coil spring, by a body member and the spring pad

Methodology Applied
Scientific EffectForce distribution: Pressure Increase

Data Source

PatentEP4056393B1Suspension for vehicle
Publication Date: 2025.07.02 HYUNDAI MOTOR CO LTD
  • EP4056393B1 patent drawingFigure 1
  • EP4056393B1 patent drawingFigure 2
  • EP4056393B1 patent drawingFigure 3~4

AI summary

A suspension for a vehicle is configured such that, even in a situation of departing from a range (spring freedom height) in which a coil spring may be tensioned as a rebound state is added in a full rebound state, a lower end of the coil spring is coupled to a spring pad coupled to a leaf spring and continuously supported, so that the separation of the coil spring connecting a suspension arm to a body member may be prevented. The suspension includes the leaf spring provided at the suspension arm connecting a body frame to a knuckle; a spring pad coupled to the leaf spring; and the coil spring supported, at opposite ends of the coil spring, by the body member and the spring pad, the body member being located above the suspension arm