Hydroforming on a budget

TPJ - THE TUBE & PIPE JOURNAL® JUNE 2001

July 12, 2001

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You can use several strategies for starting a hydroforming operation on a limited budget. Review your alternatives for selecting a press, fluid intensification system, and developing the tooling necessary for your operation before you take the plunge.

In today's business environment, characterized by cost-cutting measures and increasing competition, it can be difficult to justify spending money on new manufacturing equipment. It can be especially difficult to justify purchasing equipment for a competitive niche market, such as hydroforming. The costs associated with hydroforming equipment, tooling, supplies, and additional employees can be prohibitive, especially for a small company.

However, it is possible for a company with limited resources to start up a hydroforming operation. You should begin by exploring all of the alternatives for equipment and tooling and developing a group of strategies for controlling costs.

Hydroforming Equipment and Tooling: Decisions, Decisions, Decisions

The three basic items necessary for hydroforming are a hydraulic press, a hydroforming fluid intensification system, and a hydroforming tool. The first two items—the hydraulic press and hydroforming fluid intensification system—are available either as separate components or as a single unit.

Presses. Purchasing a complete press could be the best option for some companies. It's simpler to purchase an entire unit from one vendor because it eliminates any uncertainty about compatibility between two separate units and can simplify troubleshooting, service, and warranty issues. However, a single unit can be expensive, and there are other costs, such as installing a new press pit at your facility and assembling the press when it arrives.

A second option is to combine a standard hydraulic press with a hydroforming fluid intensification system. This approach allows you to shop around for components that suit your needs best, and it might be less expensive. This option was used recently by an automotive industry Tier 1 vendor. The combination included a 2,500-ton hydraulic press from a Korean vendor and a 30,000-pounds-per-square-inch hydroforming fluid intensification system from a U.S. supplier. The company saved more than $500,000.

If you already have a hydraulic press, a third option is to combine it with a newly purchased hydroforming fluid intensification system. These systems can be tailored to your manufacturing needs with a goal of reducing costs. This type of hydroforming system has been in production for more than 10 years.

Tooling. Another area for potential savings is in the tooling. One method is to develop hydroform tools with interchangeable components so you can make different parts.

For example, one supplier of products for the appliance industry manufactures more than 1.5 million oven handles each year. The handles have 30 different part numbers but require only three sets of master tools. These master tools have removable inserts that can be interchanged at a fraction of the cost of developing separate master tools for each handle style.

Eliminating Primary and Secondary Operations

Once the hydraulic press, hydroforming fluid intensification system, and hydroforming tools are in place, how else can you save money with this technology? Use the hydroforming tools to eliminate primary and secondary operations.

The oven handle is loaded into the hydroforming tool as a straight length of tube. The hydroforming process fills the tube with water. As the upper tool descends, it forces the tubular blank into the cavity, with the water acting as a liquid mandrel, which prevents the tube from collapsing. After the upper has descended completely and the press has achieved clamping force, the hydroforming fluid intensification system goes to high pressure and fills out the part's shape. This process eliminates a 2-inch CNC tube bender and an operator. This can save more than $250.

The engine cradle shown in Figure 1 needs to be prebent and requires severe shape changes with back angles, holes, and slots. The photo on the left shows a blank part in the lower hydroform tool. The completed part is shown on the right. In a typical hydroforming process, this part would require the following operations:

  1. CNC bending in four places, which requires compound bending because of the proximity of the bends.
  2. Preforming, which requires additional tooling and labor (and perhaps even another press).
  3. Hydroforming and hydropiercing.

However, this part was made with the following process:

  1. CNC bending in only two places—the outside bends—without compound tooling, which saved $20,000 and eliminated 16 seconds from the bend process.
  2. Bending, forming, and piercing by hydroforming. This eliminated the preforming operation, which saved approximately $45,000 in tooling plus additional labor.

Saving More by Planning, Planning, and More Planning

The most important thing that a company can do is to shop around and find a supplier that specializes in engineering, process, and design of hydroforming systems. By acting as a consultant, the supplier can help to maximize your hydroforming applications. The supplier also can recommend equipment changes to reduce the capital investment needed to help you get started hydroforming components for your customers.



Kevin Webb

Contributing Writer

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TPJ - The Tube & Pipe Journal®

TPJ - The Tube & Pipe Journal® became the first magazine dedicated to serving the metal tube and pipe industry in 1990. Today, it remains the only North American publication devoted to this industry and it has become the most trusted source of information for tube and pipe professionals. Subscriptions are free to qualified tube and pipe professionals in North America.

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