New developments in design and manufacturing automotive bulb shields by Avinash G

8/7/2019 New developments in design and manufacturing automotive bulb shields by Avinash G

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ew developments in design andmanufacturing utomotive bulb shields

vina sh G10ME61R03



+CONTENT

n Introduction

n Formability at Progressive Speed

n Rigidity Improvement by Tailor-Welded Design

n Drawing and Cosmetic Prediction

n Global Manufacturing

n Conclusion

n References



+1. INTRODUCTION

Shield

Leg

Bulb shield development has

.experienced three stages During the, -1990s the original three piece bulb shield created in the 1980s became a

- .two piece bulb shield design From the, -late 1990s through today a one piece

.design has become the most popular

BulbShield

.Fig 1a



+1. INTRODUCTION CONTINUED..

Head Lamp Assembly

.Fig 1b

1.Bulb

2.Bulb Shield

3.Reflector



+1. INTRODUCTION CONTINUED..

n Understanding the sheet formability at progressivespeed by design and conducting dome tests.

n Improving both rigidity and formability by tailor- weldeddesign.

n Providing an accurate quote and reduce lead-time byFEM prediction deformation and cosmetic effect.

n

Increasing economic efficiency by creating a globalmanufacturing structure.



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n

In this study, the dome size is scaled down to a diameter of 71 mm, the size range of a common bulb shield.

n As we see from fig.2a USI 75 ton press with a rocker armdrive was chosen to run the test at 45 strokes/min and203.2 mm stroke distance. The maximum speed is about

27,432 mm/min.

U S I7 5 To n Press W ith a R ocke r A rm

D riv e .Fig 2 a.1 G a s sp rin g ; .2 P u n c h ; .3 B ind er; :4 D ie rin g ; .5 C o u n te r p u n c h

2. FORMABILITY AT PROGRESSIVE SPEEDCONTI..



+2. FORMABILITY AT PROGRESSIVE SPEEDCONTI..

n The tested sheet steel is prepared into six coupon shapes which are designed with width varying from 4 mm to 71 mm

n - .Twenty five coupons are prepared for each shape Ten coupons.are used to adjust the stroke till the necking happens

.Fifteen coupons are etched with 2 54 mm diameter circle.grids using a Lectroetch grid marking system




n Fifteen coupons are etched with 2.54 mm diameter circlegrids using a Lectroetch grid marking system.

n Major and minor engineering strains are measured by Mylartape.

.a C ircle g rid s .b Strain

ca lcu la tio n

.c Strain

m e a s u re m e n t




. .a FLD of 0 762mm thick cold rolled steelCQ

Minor engineering strain

M a

j o

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i n

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r i n

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s t

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. .a FLD of 0 7mm thick AKDQ

M a

j o

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i n

e e

r i n

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s t

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.a FLD of 1mm thick HSLA 450

M a

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+3. RIGIDITY IMPROVEMENT BY TAILOR-WELDED

DESIGN

Laser welding tailored strips

coiler

Leveling machine Preparation of strip

edges

Pinch roll units

feed

Laser welding

pinch

coiler




DESIGN CONTINUED..n Tailor-welded blank (TWB) technology was initially developed

in the 1940s.

n TWB technology entails the welding of different steel sheettypes and thicknesses together prior to the forming

processes.

n Bulb shield vibration durability can be improved significantlyby choosing a stronger leg.

n The technology removes unwanted geometric variation by

sequentially flattening the strip, evenly feeding speedcontrol, edge preparation and sensor controls and inert gasprotect laser welding.

n The potential cost reduction over a two-piece assembly isestimated at 25–35%.




DESIGN CONTINUED..




DESIGN CONTINUED..

Strip combinations in the tailored weld striptest



+4. DRAWING AND COSMETIC PREDICTION



+4 DRAWING AND COSMETIC PREDICTIONCONTI..

:CDS Contact surface under deformation: -FDS Free deformed sheet surface:CMS Contact surface under minute deformation



+4 DRAWING AND COSMETIC PREDICTIONCONTI..

Predicted –Nickel Chrome plated physical

part

Comparison of prediction and physical parts



+4. DRAWING AND COSMETIC PREDICTIONCONTI..

n The cosmetic appearance of a bulb shield has previouslybeen unknown until physical parts are produced from theprogressive tool and subsequently electroplated.

n Commercial FEM simulation codes provide us with the

capability to design and analyze the progressive draw atthe early stage of tool development.

n Using the output data from the FEM drawn simulation, wepropose a cosmetic prediction method to predict thecosmetic appearance of the drawn sheet metal part.



+5. GLOBAL MANUFACTURING

Global manufacturing structure for progressive tool and bulb shield production



+5. GLOBAL MANUFACTURING

n Global manufacturing means producing products at low cost, on shortnotice, and in high quality by optimally organizing resources on aglobal scale.

n FEM simulation is extensively employed in the quote, design and latertryout stage and internet provides connection between engineersand management, the potential risk of defects can be foreseen andavoided at an earlier stage.

n One additional advantage of the structure: because of the timedifference between US headquarters and overseas tool supplier, itis possible to make full use of 24 hours.



+CONCLUSION

n Automotive bulb shield manufacturing is facing many challenges. Severaltechnologies have been developed at the Isatec Technical Center, aCleveland-based engineering company, to tackle the challenges.

n Dome tests at progressive speeds are designed to understand the sheetmaterials’ formability.

n Tailored weld strip design is proposed to improve the vibration durabilityof the product without sacrificing the one-piece design benefits.

n FEM simulation- based cosmetic prediction method is proposed to predictnot only the success of the draw design but also the cosmetic effect of the drawn part.

n A global manufacturing structure is created to manufacture tool and

conduct production at lost cost and a timely manner.

n As a result of this application, the year of 2006 has seen a double-digitprofit and sales growth of US $5 million



+REFERENCES

n Z. Q. Sheng & M. Strazzanti, New developments indesign and manufacturing automotive bulb shields,22 March 2007 / Accepted: 17 September 2007 /Published online: 17 October 2007 Springer-VerlagLondon Limited 2007



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New developments in design and manufacturing automotive bulb shields by Avinash G