Energy chain for high lifting speeds in press automation system

Profile

• What was needed: E4.1L energy chain
• Requirements: extremely high lifting speeds, lifting accelerations and numbers of strokes require stability and dynamics, and little space in the system
• Industry: mechanical engineering, automation and testing systems
• Success for the customer: E4 chain represents the perfect solution for the specific application: high stability with small size, low dead weight of the E4.1L version, great dynamics for the high lifting speeds and numbers of strokes, particularly small bend radii; the customer reports only good experiences and today praises the durability and high availability

The system removes the cutting inserts from the press and palletises them on sinter trays for subsequent sintering.

Problem

ROBOWORKER, based in Weingarten, Germany, is a leading manufacturer of systems for automation and inspection of precision parts. The company offers systems for virtually the entire manufacturing process of indexable inserts. ROBOWORKER stands for very flexible and compact systems, as well as for sophisticated control software. For example, using the TwinCAT real-time operating system from BECKHOFF, ROBOWORKER has developed a flexible interface for linear robots and configurable application software that optimally solves even difficult loading and palletising tasks with little programming effort.
Indexable inserts are pressed from carbide powder. ROBOWORKER's press automation systems remove the fragile green parts from the press and palletise them for the subsequent sintering process.
In order to ensure precision in the pick&place process while maintaining high throughput speeds, ROBOWORKER consistently relies on linear robots. With it, the machine builders implement a high-speed removal with a positioning repeatability of up to +/-0.02 mm. Special requirements for all components as well as the cable guidance in the press automation system arise due to the extremely high speeds and accelerations. The high lifting speeds and numbers of strokes require a very robustly built, and at the same time, flexible cables and cable guidance system. In addition to small bend radii, the guide should also be particularly space-saving. This not only helps in the dimensioning of the solution later on, but also saves energy during operation.
 

Solution

For the first time, ROBOWORKER accommodated the power and data cables for the linear robots and grippers as well as the pneumatic hoses in the igus E4.1L energy chain, which was ideally suited for this application. Because several new features of this energy chain were decisive factors of choice for this project. Most notable are its rigidity and small size. The lightweight design of the E4.1L enables high dynamics for the fast lifting speeds and stroke rates - all top priorities for this particular application. But even the very small bend radii do not pose any problems for the new solution.
The high requirements in terms of acceleration and speed could also be fully met. In the X axis, the stroke length is 1355 mm, and bend radius is 175 mm. With the Y and Z axes, the stroke is 500 mm respectively, the bend radii are 100 mm and 125 mm.
The low mass of the cable guidance despite the strong construction also reduces the risk of vibrations and oscillations. This too was a challenge, given the acceleration involved, which is more than 3.5 times normal gravitational force. At the same time, ROBOWOKER uses a specially constructed cast frame on which the entire system stands extremely still.
So far, ROBOWORKER has only had good experiences with energy chains from igus. In general, cable or energy chain failure is very rare, says Sautter, the head of design. Energy chains with a small bend radius have been used in earlier projects. Even custom-made items were sometimes needed to meet the requirements of ROBOWORKER.

The new E4.1L energy chain is very durable and about 30 per cent lighter than the standard version.

The energy chain is easy to open and close, and the shelves are also easy to assemble. This enables fast assembly times.

Energy chains on the X and Y axes of the linear robot. Here, the open energy chains are easy to assemble and, thanks to the small bend radius, take up very little space.

The fully-enclosed version of the energy chain is used in the z-axis.