To achieve greater speed and versatility from production lines, extending beyond press machines to include the development of automated transfer equipment is vital. Article by AIDA Engineering.
In recent years, metal formers have come to demand even greater speed and versatility from production lines. Relying on the capabilities of presses to meet all of these demands, however, is impractical. It is vital to extend beyond press machines to include the development of automated transfer equipment like material feeders, industrial robots, and even research on processing approaches.
Today’s manufacturing trends particularly in the automotive industry, required press makers to produce complex parts from thinner yet stronger materials. Press line automated transfer equipment systems are flexible, allowing press maker to manipulate the part during production and reducing material waste when compared to progressive die, coil-fed applications. In addition to dedicated transfer presses, automated transfer equipment systems can be incorporated with straight side presses and gap frame presses, too.
Deciding on which automated transfer equipment systems is appropriate depends on two basic criteria; 1. part complexity and 2. production volume. It is also important to find a press builder that can act as a single source for the press, the automation, the axillary equipment, the integration services, the installation, the runoff and the post-installation support. The AIDA Group manufactures not only presses with material feeders and transfer robots but also the various types of peripheral equipment required for press automation systems. This enables easy synchronisation with presses and ultimately leads to higher productivity.
Compact High-Speed Servo Tandem Line For Small Spaces And High Productivity
A flexible production line composed of multiple general-purpose presses with conveyance robots positioned between the presses. Small general-purpose servo presses and press-to-press NCAH-III high-speed conveyor robot does not require major infrastructure equipment to install the equipment, and its small size also enables installation in factories with limited headspace. This is a solution that enables high-performance press metal forming even in a constrained environment.
Presses and robots are used in one-to-one pairs. This line can be freely used in combination with material feeders by adjusting the feed pitch and the transfer direction. And despite their small footprint, they equal or exceed the productivity of transfer presses. Compared to large presses, installation costs are 20–30 percent lower, delivery is at least 50 percent shorter, and the high costs of transfer dies are avoided entirely.
Crossbar Transfer Systems
Crossbar transfer systems directly transfer materials at high speed between presses in servo tandem lines. These systems were developed for automotive body panel forming systems. Using cutting-edge synchronisation control technologies and lightweight high-acceleration transfer arms, AIDA succeeded in setting a new world production speed benchmark of 20 spm for a deep draw-forming system (20 products per minute) thereby achieving one the
world’s fastest productivity rate for press-formed automotive body panels. major challenge of high productivity, a new synchronisation system for the high-speed press-to-press transfer robot system was developed. Despite the necessity of slowing the press speed in the forming portion of the stroke to achieve the required high-level deep drawforming, AIDA was still able to achieve one of the world’s fastest speed. As a forming systems builder, the Company was able to fully leverage its advanced knowledge of and experience with many types of automation.
High-Speed Transfer System Development
The most striking difference between a servo press and a conventional mechanical press is the ability to freely program the slide motion and speed on a servo press. This heretofore impossible optimisation of press slide motion to match each metalforming application has become an important factor to enhance value-added benefits such as increased productivity and improved formability achieved through press metalforming technologies.
There’s a demand from automotive air bags manufacturing industry to develop a transfer system that could be used together with “pendulum motion.”
Pendulum motion is a unique motion only possible on servo presses, equipped with AIDA’s independently developed direct drive mechanism. The top dead center of the stroke is set as close to the product height as possible, and the motion of the press looks just like the motion of a pendulum. The shorter the stroke length, the faster the per-piece production speed becomes, and in some cases, it has resulted in a nearly 50 percent leap in productivity.
Rising To The Challenge
However, there were many problems that had to be solved in order to achieve transfer forming methods that could accommodate pendulum motion. Transfer forming is the process of performing multistage forming within a single press machine. In order to convey (transfer) the product between stages, press mounted transfer equipment continuously performs the process of moving two “arms” (feedbars) which grab the part while the press slide is upstroking, carry it to the next stage, and then place it in the die, after which the feedbars are immediately retracted to prevent interference with the dies as the slide downstrokes.
Because the pendulum motion stroke length is shorter, the slide upstroke time is also much shorter compared to standard slide motion. The difficulty lies in how to coordinate the transfer equipment motion with the press motion within this short window of time. Moreover, in this specific case there were not just issues related to pendulum motion, there was also the issue of accommodating variable slide speeds during the stroke, as the speed in the forming portion of the stroke was 20 spm, which then increased to 60 spm in the non-forming portion of the stroke. This was the impetus for the development of a short-stroke TCS system, which was a challenge that could only be met by a forming systems builder such as AIDA, because press technologies or transfer equipment technologies alone could not solve this problem.
Under a conventional scenario, the transfer equipment would be synchronised with the press motion and that would then dictate the transfer feeder motion. However, as this case called for the synchronisation of the transfer feeder with the fast motion of a press with a shortened stroke, it required impossibly quick acceleration and deceleration functionality from the transfer feeder. In order to keep the transfer feeder acceleration and deceleration within attainable ranges, AIDA had to find the “optimal independent timing” for a transfer motion that was momentarily independent of the press motion. The goal was to achieve a fine-tuned timing that would just barely be outside the press motion boundary.
If the choice had been made to increase the size of the transfer equipment servo motors, it would have increased the speed of the transfer and solved the problem, but it would have substantially increased costs. Leveraging its in-house expertise in integrated systems technologies, AIDA was able to use the existing motor capacities and still achieve a system that provided 40 percent higher productivity than standard production methodologies.
For more information, please visit www.aida.com.sg.