Die Driver

Summary:

The local sheet metal manufacturer, Jensen MetalTech, uses a press brake as one of it’s many metal-forming tools. To produce various shapes, large punches and dies must be swapped into and out of the press brake. Unfortunately, the tool-swapping process at Jensen MetalTech was inefficient and dangerous. This was due to the size and weight of the tools, as well as the methods used for storing them. Some of the heavier punches and dies weigh 400 pounds, and are 6 feet long. This combination of weight and size created a lifting risk. In addition, these tools were stored in various orientations and at different heights. This compounded the problem of lifting the tools, because they had to be reoriented and lifted to the proper height to be used in the press brake. Team Die Driver was tasked with creating a system for minimizing the risks involved in this process. The video below summarizes the steps that the team took to do this:

 

 

 

Overview:DD1

The tool-swapping process at Jensen MetalTech was inefficient and dangerous. This was due to the size and weight of the tools, as well as the methods used for storing them. Some of the heavier punches and dies weigh 400lbs, and are 6 feet long. This combination of weight and size created a very real lifting risk. In addition, these tools were stored in various orientations and at different heights. This compounded the problem of lifting the tools, because they had to be reoriented and lifted to the proper height to be used in the press brake.

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Objectives:

To combat this problem, the team created a set of objectives for improving the tool-swapping process. These objectives were used as a benchmark for the success of the project, and also facilitated the design process. The objectives were:
  • To greatly increase the safety of the swapping process
  • Allow the press brake operator to swap the tools with as little force as possible
  • Make the swapping process as quick and easy as possible

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Methods:

The team opted to create an entirely new system to facilitate the swapping process. By doing so, the design was able to embrace benefits of modularity. A set of racks and a positioner were envisioned with a common interface for quick, effortless swapping. A module with this interface was constructed as a proof of concept, and then later integrated into the system.

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Friction Reduction Elements:

A roller system was implemented for reducing the friction force from the heavy dies. Several designs were made due to the different sizes for each die, cost, and ease of fabrication and assembly. The original roller design consisted of a shoulder screws, spacers and ball bearings. This proved to be very expensive and could only accommodate dies that were 1.8 inches wide. Although this roller system would have sufficed, the design team wanted to create a system that was more robust and could adapt to future needs.

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The final roller design shown below can now be used to hold virtually all dies as it supports a range of widths. The cost has been minimized by using inexpensive screw and washers instead of shoulder screws and spacers. This design was also better suited for fabrication and assembly, as it does not have a U-shaped channel for screws.

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A punch key support was also created in order to accommodate the L shaped key on each punch. This key support is made out of a low-friction material (bronze) and is designed to be easily replaceable.

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Analysis:

To create the Die Driver system, the team used computer aided design software and finite element software. Safety remained an utmost concern throughout the entire design process, so FEA studies were rigorous and frequent. The following FEA studies were conducted to ensure that the design was safe:

  • Downward load on driver chassis (600lbs)
  • Splitting forces on the punch key holder (200lbs)
  • Massive fully-loaded tool weights on racks (8400lbs)

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Results:

By working in collaboration with the experienced professionals at Jensen MetalTech, the Die Driver system was constructed. The design did an excellent job of proving the viability of the roller system for reducing friction forces. Project Manager Joe Gauntt stated that the system will be implemented in future press brake operations.

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 Lessons Learned:

The team gained invaluable experience by working with the experienced engineers at Jensen MetalTech. Team Die Driver discovered the significance of proper assembly instructions, as well as the importance of an immaculate bill of materials.