Optimised material flow in sheet metal processing

The company

Heimann GmbH & Co. KG has its headquarters in Olbernhau in the Ore Mountains (Germany). It's a fitting location, because metal processing has a long tradition here. The Saigerhütten complex in the town was even named a UNESCO World Heritage Site in 2019. Heimann GmbH & Co. KG is a fifth-generation family-owned business founded in 1902. The company manufactures high-quality steel structures for a wide range of applications, from special plant construction, mechanical engineering and municipal utilities to complete industrial buildings. With the addition of a new workshop, the company has expanded its central site to 18,000 m² of production space.

Requirement

The people responsible at Heimann planned the flow of materials in the new workshop very carefully, taking into account the fact that components with very different shapes, dimensions and weights will be handled there. These are mainly steel sheets that are prepared for installation in complex steel structures through various process steps such as cutting, grinding and straightening.

The aim here first of all was to plan crane systems that were as versatile as possible, for example systems that could also be operated in tandem and that could ensure that the cutting systems are fed with sheets of different sizes. Secondly, possibilities needed to be created to handle the cut-to-size (i.e. significantly smaller) components on processing machines in batch sizes of one, for the purpose of efficient flow production. The components are therefore transported on two levels: firstly, crane systems feed the cutting machines, and, secondly, workstation cranes support the processing steps.

Solution

Three cranes on a common crane runway handle the steel sheets removed from the warehouse. Two single-girder cranes and one double-girder V-type crane with 10 and 12.5-tonne load capacities are used. The weight-optimised design of the V-type girder ensures, among other things, high load-bearing capacity for a low deadweight and reduced load sway when the crane travels. All three cranes are equipped with infinitely variable long and cross-travel drives. The frequency inverters of the drives make it much easier for the crane operator to avoid load sway during long travel.

When handling the blanks and components at the workstations, several crane systems from the Demag KBK modular crane system make work much easier and at the same time create the conditions for an efficient flow of materials. Two KBK monorails with a track length of 12 and 29 m ensure efficient point-to-point handling. Power is supplied through the KBK II-R profile section via an integrated conductor line. This eliminates the need for externally visible power supply cables, which also eliminates any risk of collisions.

KBK single-girder and double-girder suspension cranes also serve the workstations at Heimann. The production processes are optimally linked, and the employees can ergonomically and smoothly transport the blanks and components within the production lines.

The KBK double-girder crane has a runway length of 20 m, along which a crane bridge with a span of 4.2 m travels under electric power. The crane bridge is driven by Demag DRF 200 and a ZBF63 A 8/2 drive motor with two-stage travel speeds of 5.00/20.00 m/min. Heimann uses a high-performance DC-Pro 10-1250 as a hoist with two-stage lifting speeds of 6/1.5 m/min and a load capacity of 1250 kg. The unmachined parts and heavy metal plates are thus transported from the deburring to the chamfering workstations.

A total of nine Demag Manulift chain hoists in the two KBK systems are operated ergonomically and with just one hand using the control handle. The operator does not need a separate control unit. They can easily control the load by thumb using rocker switches on the control unit, which is integrated into the load-bearing arrangement. The control unit is suitable for both left-handed and right-handed users, so every crane operator can work ergonomically.

The Manulift is used, among other things, for precise positioning of the components at workstations across various production centres and as a travelling hoist for KBK single-girder cranes with different runway lengths and spans. Two particularly short crane girders with a span of 1.1 m stand out. These help to load manufactured metal parts from a pallet onto the roller conveyor of a roller straightening machine and back onto a pallet after the production step is completed.

Three questions for Tilo Kupfer, Sales Engineer responsible for the Heimann GmbH & Co. KG project in Olbernhau (Germany)

 

Demag: Mr Kupfer, what information do you collect when you meet a customer for the first time?

Tilo Kupfer: First of all, the customer describes which processes they would like to carry out in the new workshop or with the new lifting equipment in the future and where the lifting operations will take place. The properties of the stored goods – in particular their dimensions and weights – play a role, as do the user's objectives, for example in terms of flexibility and throughput.

This results in a basic concept for the selection and number of cranes or the KBK system, which will be further refined over the course of the project. This includes a discussion of safety, ergonomics and operation, among other things. Are variable-speed drives required, which level of positioning accuracy is required, and which lifting and load handling devices are used? Should cranes work in tandem and, if so, where? Do loads need to be turned over? These are all questions that need to be answered before we can start working on the concept in more detail.

Demag: Which product features are particularly worth mentioning from the systems at Heimann GmbH & Co. KG?

Tilo Kupfer: Heimann sometimes prepares very large and heavy steel sheets for further processing, e.g. in workshop construction, with operations such as flame cutting and straightening. The environmental conditions are rather harsh and the cranes are expected to be highly reliable and available.

 

The wide range of Demag products in various areas of the company is certainly worth mentioning. We have box-section and V-type single- and double-girder cranes, as well as several KBK modular systems. Heimann attaches great importance to safety and ergonomics, which is another reason why we have selected a custom-fit system for every lifting task and every workstation.

 

It was also important for our customer that the operator feels "at home" and safe when changing workstations, as they can use similar lifting equipment in every workshop. This includes the tried-and-tested Manulift system, which ensures ergonomic operation and is also used here in the largest size to handle parts weighing up to 500 kg, while being operated by just one hand.

Demag: Which customer requirement was particularly exciting in this project?

Tilo Kupfer: In my opinion, the exciting thing about planning the KBK system was the directly parallel arrangement of cranes and monorails. We thus created the conditions for the operators to transfer workpieces to the work areas without the need to set them down.

One challenge in planning the project for one of the two V-type cranes was the possibility of controlling two travelling hoists both separately and in tandem operation. This means that flat sheet metal parts or unstable long components can be handled safely and precisely. 

Special features

When planning the cranes and KBK systems, the planners from Demag and decision-makers from Heimann placed great importance on the design of the transfer points. This resulted in an integrated handling system that is highly flexible and meets all the requirements of the specific lifting and handling tasks – for very different and often very bulky goods.

In addition, the KBK system was perfectly integrated into the production environment – sometimes even into the enclosed work areas of machines, e.g. the straightening system.

Heimann places high demands on safety. All cranes are equipped with the SafeControl system developed by Demag, which continuously monitors all relevant crane functions and movements, including overlapping movements, with a focus on safety.

SafeControl also enables two travelling hoists to work in tandem on one of the two double-girder V-type cranes: a useful option, especially when long steel sheets and profiles need to be handled and cut.