As sheet metal fabricators around the world start to ramp up manufacturing operations following the coronavirus pandemic, many will look for opportunities to improve efficiency and build a more modern, resilient business. Automation will play an increasing role as a way to offer a high level of flexibility and reliability and allow for physical distancing. The global crisis may actually speed the adoption of automation.
For bending operations, advances in machine, software and robot technology make automation more practical for companies that want to optimize workflow, shorten turnaround time, lower production costs and become more adaptable for the future. In fact, the characteristics of the modern robotic bending cell can help fabricators more easily justify the move to automated bending.
Reliable robotics
Today’s robotic bending cell operates reliably and without operator intervention – 24 hours per day if required. As the manufacturing industry continues to face a shortage of skilled labor, automation offers an attractive solution.
While workers are still needed to oversee the operation of a robotic bending cell – to monitor the process, materials and surroundings – a bending cell like LVD Strippit’s Dyna-Cell automated system requires fewer skilled operators and leaves the repetitive tasks to the robot. This frees workers to perform other higher value tasks – shifting their duties to job preparation and scheduling, data analysis, process and workflow management, or retraining for a different assignment.
Because the cell can work largely unattended, it can operate over multiple shifts as well as lights-out. A large input and output capacity hastens lights-out production. In the Dyna-Cell bending cell shown on the right , the input station can feed up to 1,800 small parts at a size of 220 mm by 150 mm by 1 mm along with 800 parts sized to 360 mm by 25 mm by 1 mm. The cell has four input pallets with a varying number of piles and stack sizes, and pallets are easily moved with a forklift.
The bending cell also offers two output positions: Parts can be easily “dropped” into a bin sized to 1,200 mm by 800 mm by 750 mm or parts can be stacked on a pallet in multiple layers up to 750 mm high. This input/output configuration uses a small amount of floor space and offers the flexibility to handle a large variety of parts.
Certain models of robotic bending cells, including LVD’s Dyna-Cell, feature built-in real-time adaptive process control. This technology delivers a high level of quality assurance, providing automation with a quality guarantee. Without the need for calibration, the real-time adaptive process control adapts to material variations, including sheet thickness, strain hardening and grain direction, automatically compensating for any changes. As a result, the formed part is accurate from the first bend and there is repeatable accuracy in the bending process. With no part failures, there is a high degree of process stability and consistency.
Automated intelligence
Automation has the reputation of being time-consuming, expensive and customized to projects with a long lifecycle. Robot teaching is one area that has required significant time and experienced operators. Unlike the systems of just a decade ago, there is no need for advanced robot programming skills to use a robotic bending cell.
Modern robotic bending cells, such as the Dyna-Cell, need no robot teaching, and programming for the press brake and the robot is handled offline. The programming itself is easier because of automated and “drag and drop” functions within the programming software. A main example is seen in LVD’s bending software, which automatically calculates the optimal program – bending sequence, tool setup, finger positions, angle measurement positions and collision detection.
Furthermore, the robot software imports all bending data and automatically calculates all gripper positions taking into account the gripper force, collision detection and robot reachability. The system automatically calculates the fastest collision-free path for the robot across the complete bending operation.
For every job, the database contains all the setup information needed for the press brake and robot. All the information is available on the controller so that production can begin immediately.
With the wealth of digital information and 3-D visualization available, the operator has a smart assistant to quickly set up the cell for production. Programming steps can be simple and quick and can take 20 min. or even less, depending on the part. The order of operations can go as follows:
Program the press brake offline: Import the CAD data into the bending software to prepare the press brake program. Export the program to the robot software. Takes approximately 2 min.
Program the robot offline: Import results into the robot software and prepare the program for the robot. Combine these results with the results from the bending software and export to the press brake database. Takes approximately 8 min.
Bend a part manually on the press brake: Bend at least one part manually using the offline generated program. Bend until the part is within angle and leg distance tolerances Takes approximately 2 min.
Bend a part with the robot: Bend at least one part and verify the robot path and approach points. If all is OK, start production. Takes approximately 8 min.
The present-day robotic bending cell also uses one centralized controller to manage both the press brake and the robot. A self-explanatory graphical user interface means interaction with the cell is simple, intuitive and as efficient as possible. The entire cell can be operated with a touch control.
Today’s flexibility
The Dyna-Cell modern robotic bending cell can operate automatically as well as manually. In a more traditional fully enclosed, fully automated cell, this flexibility is not possible. But modern bending cells allow the fabricator to easily switch from automatic to manual mode.
When automated operations aren’t necessary, the press brake can be used as a standalone machine, essentially providing an additional bending machine. One mid-sized fabricator operates the cell manually during the day for small batches or urgent jobs and uses the cell in automated bending mode for large production runs overnight. This fabricator operates two automated bending cells in this fashion, using one operator during the day for the two machines.
Another feature that robotic bending cells can offer is the flexibility afforded by robot grippers. A bending cell that’s configured based on a specific high-volume part requires a special robot gripper or multiple grippers. A bending cell with a universal gripper that fits most common product families offers increased flexibility and savings from not having to invest in robot grippers of varying sizes.
The modern robotic bending cell is economical to own and operate and fits a broad range of applications, including high-volume repeat jobs and low-volume jobs that sporadically reoccur. In contrast, specialized bending cells designed to bend very specific products in large volumes can be extremely expensive and come with a high cost per part. As fabricators rebuild and look ahead, modern bending automation technology can offer a way to address issues such as labor shortages, higher wage costs and quality control, and pave a path to a more resilient business.
