BON KOK WUI & TAN MING SHENG

Date – 27th August, 2013

A Total Solution for Automotive Helical Spring Design

APM Engineering & Research Sdn. Bhd.

Seating Systems

Complete Seating System from OEM RFQ.

New seating mechanisms (Track, Recliner, Height adjustment, Lumbar etc).

Suspension System

Range of coil, leaf and parabolic springs, air bellow.

Shock absorbers.

Corner Module.

Complete Leaf Spring Suspension Module.

Gas Spring

Climate Control

Radiator, Condenser cores and assembly.

Blower fan and shroud.

Complete A/C Cooling module.

Interiors and Plastics

Door Panel and Interior trims & head liners.

Instrument Panel, Bumper System

Company Background : APM Engineering & Research Sdn. Bhd.

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Current automotive design trend: Better Fuel Efficiency & Larger Cabin Space.

Consequences: Suspension design package reduced, complexity of design increased.

Design process become more complex due to the limitation of the design package. More and more consideration is required which is unable to capture by general design formulation.

CAE as a design tool to realize design blind spot and provide better understanding to the designer through virtual realization

Introduction

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Objectives

To simulate coil spring behavior along the working stroke during design stage in order to detect the potential risk prior to prototype making.

To evaluate Coil Spring design based on below criteria along the working stroke:

Load & Spring Constant

Principle Stresses & Shear Stresses

Interference with Surrounding Package

Rubber Force distribution

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Drawing and Design information for prototype

Generate FEA Report

Customer Input

Customer Approval

Preliminary Design Calculation

CAD Drawing

Computer Aided Engineering (CAE)

Load Analysis Stress Analysis

Rubber Force Analysis Interference Analysis

Feasibility Study

No No

No

Sample Development

Methodology

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Model & Load Case Description

In Vehicle Condition :

Upper seat is fixed in ALL degree of freedom . Displacement is imposed on the lower seat.

Imposed Displacement

Fixed

Coil Spring

[Steel] 3D Spring Seat

[Steel] 2D

Rubber Seat

[Rubber] 3D

Surrounding Packages

[Steel] 2D

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Detailed Analysis Result : Load & Rate Plots

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Principle Stress Shear Stress

Detailed Analysis Result : Principle & Shear Stress

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Bottom View

Cross-section View

Iso View

Detailed Analysis Result : Interference with Surrounding Packages

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Mating Parts Dust Cover

Rubber Seat Spring Seat

Detailed Analysis Result : Interference with Surrounding Packages

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Mating Parts Dust Cover

Rubber Seat Spring Seat

Detailed Analysis Result : Interference with Surrounding Packages

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Detailed Analysis Result : Rubber Force Distribution

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Conclusions

From the simulation, the potential risk is identified. Therefore design changes can be made during the initial design stage.

A full picture of helical spring behavior along the working stroke is illustrated through simulation to enable design engineer for a better judgement ensuring fulfillment of customer’s requirement.

CAE provides a total solution for automotive helical spring. Not only a higher efficient and comprehensive tool, it is also an enhancement for the helical spring design process.

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Special thanks to those who contributed in this study: APM Engineering & Research Management & Staff APM Coil Springs Management & Staff Altair Engineering Mr Vishal Pawar Mr Mangesh Gite

Acknowledgements