February 26, 2004 | By Gary Morphy
Combined with the information in Part III of this series that focused on cross-section expansion before hydroforming, this article discusses the most common options used in preparing tube for hydroforming and achieving the designer-intended part. Properly executing bending and cross-section...
January 13, 2004 | By Eric Lundin
Hydroforming was one of the fastest-growing metal forming technologies during the 1990s. Most of U.S. industry cooled down during and after the recession of 2001, but things have been heating up lately, and the world of hydroforming is no exception. The North American Hydroforming Conference and Exhibition (Sept. 29 – Oct. 1 in Dayton, Ohio), which was sponsored by the Tube & Pipe Association, International® (TPA), and the Society of Manufacturing Engineers (SME), showcased new techniques, equipment, and applications that are moving the industry forward.
October 23, 2003 | By Gary Morphy
Material selection is a very important aspect of design flexibility when striving to fulfill part functionality requirements. Choosing the correct material is fundamental to making the part effectively and efficiently. The way a material is formed and the conditions it needs to withstand for...
The most common way to establish tube length after hydroforming is by cutting or shearing the tube to a specified dimension; however, cutting out this step can reduce scrap. A new method designed to eliminate this step combines forming the end of a tube to resemble its final form with using a hydroform die to correct end position variations off the bender. While this approach eliminates the final shear trim operation, it also presents new challenges.
Hydroforming is one of the most important fields in production manufacturing. In recent years many single presses, groups of presses, and entire production plants for internal high-pressure (IHP) hydroforming of tubes and extrusions have been installed, especially in the Americas and in Europe. The driving force behind this development has been the efficient production of automotive parts.
Hydroforming has become a competitive metal forming method and has succeeded in many applications because of its weight- and cost-saving attributes, elimination of joining operations, and ability to offer part design for confined spaces.
July 24, 2003 | By Eric Lundin
F & P Manufacturing Inc., a tier-one automotive components supplier, focused on four areas when it developed a hydroforming line for manufacturing Honda Accord engine cradles. These areas were eliminating end scrap, decoupling the bending machines from the manufacturing line, reducing cycle time, and palletizing parts.
July 10, 2003 | By Dr. Ghafoor Khodayari
It is well-known that tube has become an important material for hydroforming hollow components. The increasing complexity of product structures, particularly in the automotive industry, often requires one or more forming operations before a tube actually is hydroformed. Prebending is one of these forming processes used to prepare tubes for the so-called prebent tube hydroforming.
June 12, 2003 | By Atsushi Shirayori
For hydraulic tube bulging, direct pressure control is the most commonly used process. Pressure control allows engineers to determine the correct capacity hydraulic system and, more importantly, prevent tube rupture. However, inflow control, or control of the volume of fluid inside the tube, theoretically could be another viable hydroforming process. Finite element analysis has shown that inflow control could allow engineers to more accurately predict deformation behavior and therefore enhance the hydroforming process.
April 24, 2003 | By Gary Morphy
The last article in this series noted that variable periphery design, or cross-section expansion, often is thought to be the most important aspect of tube hydroforming design flexibility. Expansion in the hydroforming die commonly is assumed to be the most efficient and most effective method,...
March 27, 2003 | By Tom Driggers
Hydroforming is gaining ground in the manufacture of many automotive components,such as pillars, frame rails, and engine cradles. Automakers are finding hydroforming advantageous for forming many smaller parts also. The process is useful for manufacturing an automobile fuel filler tube, which is the expanded portion of a fuel filler assembly where a fuel nozzle is inserted.
October 24, 2002 | By Serhat Kaya
Passenger car fuel tanks have for many years been made out of plastic. To reduce MTBE leaks in the groundwater, the Department of Energy, The State of California, and the Western States Petroleum Association are studying material alternatives such as high-strength steel, stainless steel and aluminum gas tanks.
October 10, 2002 | By Shrinivas Patil
As tubular hydroforming becomes a competitive process for the mass production of automotive parts, a tube's material properties must be consistent. To predict variations in material properties, many tube producers use the uniaxial tensile test. Because the specimens for the tensile test are collected before a tube is bent and welded, they are not always accurate. To predict variations in tube property accurately, it should be tested under a biaxial state of stress.
October 10, 2002 | By Gary Morphy
It's difficult to overemphasize the importance of cross section expansion when you're talking about successful and innovative hydroforming of steel tubing. Overemphasizing one aspect of the tube hydroforming design process can take attention away from others and result in less than optimal design....
Comparing and correlating two tests, a common bench test (twist compression) and a straight-tube corner-fill test, simulate hydroforming to find the coefficient of friction.