Sorting robot on an axis

An industrial robot picks up the various workpieces from the material disposal of the sawing machine using one of the four fully automated exchangeable magnetic grippers.

For 26 years, the storage and sawing technology from KASTO has provided dependable service to the hydraulics specialists Liebherr-Components Kirchdorf GmbH. However, to reliably meet the increasing demands in the cylinder production in the future, the company decided to modernise and expand the system. KASTO retrofitted the existing bar storage system and one of the two sawing machines with state-of-the-art technology. Moreover, the high-performance KASTOtec bandsaw and a custom-made handling solution using robot support ensure efficient and ergonomic processes.

Excavators and wheel loaders, bulldozers as well as crawler and mobile cranes, have one thing in common: They require hydraulic drives to carry out their work. This machinery must often carry extremely heavy loads - in such cases, the hydraulic systems which generate strong forces and high torques are ideal. Furthermore, the technology behind it is precise and robust making this machinery suitable for the harsh operating conditions of construction sites or mining industry. All around the globe, hydraulic drives are used in countless applications ensuring that anything that should be moved, will move.

Hydraulic cylinders for any application

Liebherr is one of the most renowned experts in this field. With approx. 43,000 employees, the family-owned company is active and highly successful, for example, in the product fields of construction machines, mining equipment, crawler and mobile cranes as well as material handling technology. The mechanical production of Liebherr-Components Kirchdorf GmbH is located in Kirchdorf an der Iller, Baden-Württemberg where Liebherr was founded. Since 2018, the company headquarters is located in the neighbouring city of Oberopfingen with in-house assembly, testing and painting. The company is part of the component division of Liebherr and has specialised in the production of high-quality hydraulic cylinders for mobile and stationary applications since 1958. Every year approximately 75,000 hydraulic cylinders, suspensions and system solutions for cylinders leave the plant to be used around the world both within and outside the Liebherr Group.

The product portfolio extends from cylinders for high dynamic requirements for construction machines and industry to large heavy duty cylinders with a piston diameter from 500 millimetres and maximum stroke lengths from eight metres through to lightweight and special cylinders. Steels in various qualities are processed. The raw materials are delivered in the form of pipes and bars then stored in an automatic bar storage system, and cut to the correct lengths in the in-house sawmill.

New saw increases efficiency and cutting quality

For years, Liebherr-Components Kirchdorf GmbH has relied on KASTO for storage and sawing technology: An automatic cantilever arm and cassette storage with 733 spaces and a large bandsaw from the KASTOhba series have provided reliable service for 26 years. "Unit recently, a production circular saw from KASTO, which was just as old, was still running," recalls Stefan Lützel from Industrial Engineering of Liebherr Components. "Since then we have granted this saw a well-deserved retirement."

The reason for this was an extensive modernisation of the sawing technology initiated by the company in 2016. At that time, those responsible decided to purchase a new saw to increase efficiency and cutting quality further and to be able to process larger diameters. The old circular saw was replaced with a high-performance bandsaw from the KASTOtec SC 4 series. This is strictly designed for separating larger workpieces, in particular, solid and difficult-to-cut materials. It features a cutting range of 430 millimetres and can operate with HSS as well as carbide bandsaw blades. The saw is also equipped with the KASTO Performance Cutting (KPC) package. This includes features such as an improved band guide and vibration absorption for an even higher cutting performance.

Retrofitting as an economical alternative

The bar storage and KASTOhba bandsaw were in good mechanical working condition. However, the drives and control systems were no longer state-of-the-art after such a long time. "On the one hand, this had an impact on the availability, and on the other hand the spare parts were becoming difficult to procure," says Lützel. "KASTO offered us the option to retrofit both of the systems as an economical alternative to replacing them." This option comprised of replacing the control cabinets and operating panels, the cable carriers and cables to the operating gantry crane, measuring systems and drive controllers of the storage system. KASTO updated the drives of the storage system and saw using modern three-phase-motors. In addition, the outdated control system, as well as the safety technology, were reinstalled according to the current standards.

But that was not all: Together with KASTO, Liebherr Components developed a custom-made solution to automate the handling of the cut pieces. An industrial robot moves between the two saws on a linear axis. This robot is equipped with several exchangeable magnetic grippers to pick-up various workpieces from the material disposal of the sawing machine. The robot arm can easily lift up to 350 kilos. Along the linear axis, there are 18 storage locations for pallets and containers. The location of each load carrier is stored in the control system of the robot - thus, the robot can deposit each part precisely and gently on the specified location. Afterwards, the employees transport the cut pieces for further processing using forklifts or lift trucks.

Everything from a single source

As the general contractor, KASTO was responsible for implementing the entire project: from the modernisation of the existing saw and storage technology to the reconstruction of the new bandsaw through to the installation and setup of the linear axis and industrial robot. KASTO experts were also responsible for the integration of the various machine control systems into a uniform and easy-to-operate system. "It was a major advantage for us to have a single contact partner for all of our questions without having to coordinate between different suppliers," emphasizes Lützel. "Especially, because we had to carry out the reconstruction works during ongoing operation, without disrupting it too greatly." With this in mind, KASTO divided these tasks into several phases. In August 2016, the retrofit was conducted; in December, the KASTOtec was delivered and setup. The specialists connected this to the industrial robot in January 2017 before integrating the existing KASTOhba into the new system in the following December. "Thanks to the excellent coordination by KASTO, everything ran absolute smoothly," added Lützel.

The positive changes in the production at Liebherr-Components Kirchdorf GmbH can be clearly seen - and they certainly can be heard: "Before, our saws were equipped with so-called filling buckets - from which the cut pieces fell into the containers - that made a horrible noise every time," explains Stefan Lützel. Whereas, the robots place the workpieces accurately and quietly - this improved the work environment in the plant significantly. The new handling method has a further advantage: "We also process chromed materials that are sensitive to impact," explains Lützel. "If these are simply dropped, they are easily damaged. With the robots, we no longer have this problem."

Working ergonomically using robots

The KASTO solution has made improvements in other respects as well: Liebherr Components is now able to process material cuts up to three metres in length. The new sawing technology has resulted in a higher cutting quality than before, shorter cutting times, and a significant increase in the efficiency of the overall process. "The new system enables us to optimize our cutting process. As a result, we have less waste, and we can maximise the use of the material," describes Lützel. The automated handling ensures an ergonomic work sequence: The employees can enter the cutting orders via an operating panel. Then the operating gantry crane of the storage system automatically (unmanned) transfers the required bar to one of the two saws. "From storing of the raw material through to the complete cut and sorted cut pieces, we do not need to carry out any manual tasks," describes Lützel. This not only protects employee health but also enables the system to continue to run independently after working hours.

Since it has been in full operation, the system runs reliably without any noteworthy disruptions. If a problem should arise, all of the components can be serviced remotely. The KASTO experts can access the control systems online remotely and quickly assist from the headquarters in Achern, Baden. "This service is likewise very important to us to ensure high system availability," says Lützel. Furthermore, Liebherr-Components Kirchdorf GmbH signed a long-term maintenance contract with KASTO: In regular intervals, technicians of the sawing and storage technology manufacturer are on-site to check and maintain the system. "Thus, we are provided with optimum support even after the purchase and setup," Lützel is pleased to say.

Individual solution for special requirements

Those responsible at Liebherr Components are extremely satisfied with the collaboration with KASTO - especially since it was a real customisation: "This system as it stands here certainly does not exist anywhere else in the world," explains Lützel with a hint of pride. "The manner in which KASTO addressed our special requirements and developed an individual solution with us deserves special praise." Therefore, the hydraulics specialists from Liebherr-Components Kirchdorf GmbH can envision implementing further joint projects.

For years, Liebherr-Components Kirchdorf GmbH has relied on KASTO for storage and sawing technology.

The large bandsaw from the KASTOhba series has been in service for 26 years and is still mechanically sound.