Large diameters, tight radii: Tube bending machine for H-P Products

High stress due to tight bending radii of up to 1xD, short cycle times and compatibility with existing tools: With these requirements, the US automotive supplier H-P Products turned to Schwarze-Robitec. The German tube bending machine manufacturer responded to the complex issue with a powerful CNC 160 E TB MR. The commissioning took place in the middle of the pandemic despite strict regulations – successfully also thanks to short distances between the customer in Ohio and the Schwarze-Robitec branch in Michigan.

Founded in 1945 and headquartered in Louisville, Ohio, H-P Products, Inc. manufactures a wide range of tubular products for large diesel engine, fire truck, construction equipment and agricultural equipment industries from air intake systems to exhaust and cooling components to structural components. To bend large tubes in particularly tight radii, the company now relies on a machine from Schwarze-Robitec. With the fully electric CNC 160 E TB MR, H-P Products is replacing another model from the German manufacturer after more than 20 years of continuous service.

Schwarze-Robitec designed the CNC 160 E TB MR for two different tool sets, each with two grooves: One of the bending tools bends tubes up to 127 mm in diameter at a bending radius of about 1.1xD. The other tool bends tubes up to 101.6 mm even at the even tighter radius of 1xD. The tighter the tubes can be bent for the automotive industry, the more compact the engine and exhaust system can be designed. This particular challenge prompted H-P Products to purchase the new tube bending machine from Schwarze-Robitec. The closer the ratio of tube diameter to bending radius, the higher the load that the tube bending machine must withstand in the process. The Cologne-based expert designs its machines precisely for this demanding 1xD bending: The decisive factor is sufficient rigidity of the entire system as well as the stability of the individual tool components in relation to each other. The CNC 160 E TB MR withstands this exceptionally high stress, even over a long period of use.

In addition, H-P Products brought in the requirement to produce parts in a very short time with high repeatability – a typical requirement in the automotive industry, which is focused on short cycle times. The machine achieves this thanks to the intelligent NxG control. The motion sequences of all axes are optimally coordinated during bending, thus minimizing the production time per part. It was also important that tools previously used at H-P Products could continue to be used on the new machine. This compatibility and flexible use of the tools is guaranteed by the tube bending expert for the Ohio-based company.

Schwarze-Robitec put the large machine into operation in the middle of one of the peak phases of the pandemic, despite worldwide contact and travel restrictions. This was possible because the company has its own branch office in Grand Rapids in the US state of Michigan. While the experts at the headquarters in Cologne provided intensive support for the entire project, from consulting and development to execution, the U.S. team was able to carry out the commissioning on site at the customer’s premises in the neighboring state. In this way, customer support interlocked optimally in a digital way and in person.