Hydroforming uses High pressure fluid to form the part into the desired shape of the die.

Two types of hydroforming process: 1.Tube Hydroforming 2.Sheet hydroforming

Introduction

Tube hydroforming

Used for forming complex shapes

A circular tube is preformed and placed in a closed die

High pressure fluid is introduced into the ends of tube

Application feed thorough ends for uniform thickness

The tube if confied to the shape of the die cavity

Hydroforming History

1903: First patent for Hydroforming using molten lead to expand a tube to confirm to

shape of the die. Die closing, fluid sealing, pressurization are observed in this patent.

1917: Pre-forming was introduced for improving bent brass tube process.

1932: Patent for making artificial limbs from aluminum tube

1950: Patent for producing hallow metal aircraft propeller using high pressure fluid.

1959: Patent for producing cam shafts by axially feeding material from the ends of tube.

1960: Nippon bulge industries,Japan developed liquid bulge forming process and

high pressure sealing methods. Typical application were Bicycle frame joints.

1970:Patent for swaging(end diameter reduction),axial feeding for diameter expansion,

Piercing a slot, and in-die end shearing using high pressure fluid.

Hydroforming History

o1986:Standard Tube Canada of Woodstock, Canada used Hydroforming technique to

produce larger frame members in North America.

o1988-1989:Pressurizing the blank during the die-closing phase of the forming cycle was

introduced by Standard Tube.

o1994-1996:Higher expansions through axial end feeding, localized cam forming, and in-die

hydrobending Of large auto-frame members.

o1998:General Motors introduces the idea of using multiple, different diameter and thickness

for complete – frame Hydroforming in a single die.oProduction of more than a million engine cradles per year by hydroforming in the US.

oIn Europe hydroformed sub-frames are used for models such as Ford’s Mondeo and General Motors’s Vectra.

oChrysler is using 2.8 million hydroformed components per year.

Advantages of Hydroforming

ULSAB 1995 concluded that a hydroformed intensive body structure(HIBS) would yield ..

Reduction in weight of 11%

Reduction in Part count of 15%

Reduction in cost of 10%

Compared with similar size conventional body structure.