- In Focus
The continual objective in metal-cutting manufacturing is to further increase productivity, creating added value for the customer. As a result, new and further development of machine tools and addition of optional extensions continue. Currently, the conventional potentials for productivity increases are thought to have been fully exploited. In terms of Industry 4.0, HELLER's approach is to enhance transparency of the current machine status, evaluating the information gained in combination with existing data to allow purposeful diagnostics. To achieve this, future machine functions will be combined with powerful data extraction amongst other measures.
By means of three modules HELLER illustrates the importance of ease of operation, customised workpiece manufacturing and enhanced evaluation of existing sensor data.
HELLER4Operation is an easy-to-use, operator-oriented user interface for HELLER machines. The use of touch controls at the tool/workpiece loading station enables fast and robust operation. In addition to the familiar Siemens standard operation, the new main operator panel allows execution of customer-specific programs from web environments. The 24” touch interface named HELLER Operation Interface can be upgraded with expansion programs, so-called Xtends, enhancing performance and functionality.
The second area, HELLER4Services, comprises digital services. The HELLER Services Interface focuses on transparency of manufacturing and maintenance processes. The module forms the basis for evaluations and statistics, thus providing support in reducing machine downtimes. Additionally, the visualisation of specific information, including status displays of axes, spindles or other assemblies, enables users to determine wear and to take preventive measures in order to avoid unscheduled downtimes.
The third area, HELLER4Performance, comprises the machine analysis for process and performance optimisation, time-synchronous extraction of real-time data into the internet as well as evaluation and graphical display, e.g. using the SAP-HANA internet platform. Together with SAP, HELLER demonstrates the specific benefits of this online streaming function with the mapping of a CAD-designed 3-D workpiece in a cloud. This enables precise representation of the tool (paths including tolerances) in which tool wear is expected. Subsequently, the workpiece program is run on the machine. The data generated is directly transferred to the cloud. This way the paths to be traversed by the machine/tool can be pre-assessed on the basis of the workpiece design prior to machining to see whether the machine will be able to perform the operation.
The example of tool provisioning shows how further savings can be achieved with HELLER4Industry by linking the digital and the real world. Usually, tool magazines are loaded in a way to provide optimal storage capacity. Often, however, the tool access sequence differs from the sequence of the machining operations. It means that the distance from the tool to the spindle has a significant influence on the duration of the tool change. To reduce these unproductive times, the stock of workpieces to be optimised can be selected from the pallet management and be transferred to the cloud along with the details. This way, both the tool change times and the tool idle times can be analysed and evaluated in view of the sorting order, providing the shortest idle times for the given workpiece and the machining operation. Subsequently, HELLER generates the CNC program for re-sorting in the cloud and provides it to the machine for re-sorting of the tool magazine.
In terms of Industry 4.0, HELLER is also focusing on a further increase in machine productivity and the support of consistent engineering chains. Core aspects to achieve this are supplementary machine functions, on-demand services and enhanced service capabilities. Essential for this are new industry standards in terms of data exchange and data security as well as standardised interfaces. HELLER is accelerating the evaluation of existing machine sensors and supports network integration of the machines, using services on network computers. However, for digitisation it is important to develop data recording mechanisms capable of generating a real-life image of the machine and mapping it within a network, either in the customer-internal private cloud or in an internet-based public cloud.
For HELLER, the aim of all considerations, possibilities and solutions remains the reduction of cycle times, and thus per-piece costs, by providing high productivity. Already today, HELLER achieves the goal of generating added value for the customer through greater ease of use, optimal integration into the network and expanded functionalities and service possibilities.
Already in 2006, Mercedes-Benz began using the newly developed twin-wire arc spraying technology for the 6.3L V8 AMG engines. In 2011, the process was integrated into series production of the Mercedes V6 engines. Then in 2012, the companies Gebr. Heller Maschinenfabrik GmbH in Nürtingen and Daimler AG decided to industrialise the technology and all steps of the process. Meanwhile, the process Daimler named NANOSLIDE® is not only used in series manufacturing but has also found its way into the F1 champion's extremely successful car, the Mercedes-Benz PU 106A Hybrid.
When evaluating the efficiency of a vehicle, drivers are paying closer attention to fuel consumption now. For a number of reasons, CO2 emissions are becoming more and more important as a factor, since they also form the basis for emission limits and subsidy programmes. As a result, the automotive industry is focusing on weight reduction measures and downsizing. Today, the efficiency of a motor vehicle can be increased in various ways.
The quality of the cylinder surfaces, for example, has a major influence on the consumption of combustion engines. After all, surface hardness, roughness and texture are not only the determining factors for fuel consumption but also the performance characteristics of the engine. Up to 25 percent of fuel energy in the part-load operational range is required to overcome the engine's internal friction.
To reduce frictional losses on cylinder surfaces, Daimler AG developed an innovative thermal spraying technology that received several national and international awards, enabling the coating of cylinder bores of aluminium lightweight crank-cases for car engines using twin-arc spraying. To generate the NANOSLIDE® surface, the molten material is sprayed onto the cylinder wall by means of a gas flow and deposited as a layered, ultrafine to nano-crystalline coating. Subsequently, the NANOSLIDE® coating is smoothed to an extremely high degree in a specially developed mirror honing process, which gives a thickness of only 0.1 to 0.15 millimetres and a surface that is almost like a mirror. The honing process also exposes pores in the material, which are able to retain oil and help optimise lubrication of the piston assembly. All in all, the process enables to reduce mechanical friction loss by up to 50 percent whilst providing extremely high wear resistance.
Although the coating process is considered extremely cost-effective and technologically superior, quality-determining parameters such as current, voltage, wire feed and process gas flow need to be carefully adjusted and matched to the coating procedure.
In 2012, Gebr. Heller Maschinenfabrik GmbH in Nürtingen and Daimler AG established a successful cooperation for the further industrialisation of the process. The goal for HELLER was to industrialise all steps of the process and to develop it into a dependable application for the global markets under the name of HELLER CBC (CylinderBoreCoating)CBC coating process (CylinderBoreCoating) based on a global network of systems and services for the complete process chain of crankcase manufacturing.
In the same year, HELLER gave the go-ahead with the official opening of the HELLER CBC TechnologyCenter at the company's headquarters in Nürtingen during the Automotive Dialog 2012 and started with the coating of customer-specific prototypes. Initially, the process was used for exclusive small-batch series. With the entry into mid-sized batch production, a viable alternative to existing liner technology was born. The production rules and criteria for the automotive industry had been fulfilled and thus the preconditions for high-volume production.
To implement this next step, market-oriented solutions in terms of system supply and services were required. In 2013, Mercedes-Benz introduced NANOSLIDE® to the US market for the turbocharged V6 spark-ignition engines in the context of the BlueEFFICIENCY technologies. NANOSLIDE® helps to reduce engine weight by several kilogrammes and reduces fuel consumption by up to three percent by eliminating the need for thick grey cast iron liners used in the predecessor engine.
Meanwhile the technology is also used for the latest generation of 4-cylinder and 8-cylinder engines of Mercedes-AMG. In 2013, HELLER commissioned enhanced manufacturing systems and integrated the process, including the process steps for pre- and finish-machining, into the process chain of engine production, whilst ensuring the necessary high degree of process quality and dependability.
In 2013, HELLER and Daimler received the German Innovation Award for Climate and Environment in the category “Process Innovations for Climate Protection”. In 2014, NANOSLIDE® received an award from US trade journal R&D Magazine, the so-called Oscar of Invention, naming it one of the most important high-tech products. Today, the two partners see this as another award for a technology that has also had a share in winning the first F1 Constructor's Championship and the Drivers' Championship in 2014. NANOSLIDE® also realises its full potential in the V6 turbo engine of the current world champion's car, the Mercedes-Benz PU 106A Hybrid.
By means of twin-wire arc spraying technology the cylinder surfaces in the aluminium crankcases are coated with an extremely thin layer based on an iron-carbon alloy. The result is a very wear-resistant nano to ultrafine material structure with micropores, ensuring lubrication during operation. As a result, heavy grey cast iron liners in the aluminium crankcases that can be several millimetres thick are eliminated. The result is a surface as smooth as glass, providing up to 50 percent less friction between piston, piston rings and cylinder surface and a weight reduction of several kilogrammes. Meanwhile, the process incorporates numerous inventions and ideas and is protected by more than 90 patent families and more than 40 patents.
Shortening the process chain with the ›smart technology mix‹ from HELLER can create enormous application-specific potential. In this interview, Managing Director Christian Pfleiderer talks about maximising customer value through optimal ›Lifetime Productivity‹ of HELLER machines.
CP: All the standard models in the HELLER machine range are already equipped for numerous standard technologies and processes. And the machines are designed to allow other technologies to be integrated without major additional effort. HELLER divides the technologies into two categories.
First the primary technologies, which are within the mainstream. All models enable milling, boring and tapping and, with the C series mill/turning centres, also turning. Then there are non-mainstream technologies, such as reaming, deep-hole drilling, facing and interpolation turning, which are likewise part of the standard module, as well as special technologies, including shaping, gear cutting, honing and grinding, which are tailored specifically to the customer’s needs. As a preferred solution provider, HELLER wants to offer the optimal process every time. This is based on the recognised strengths of HELLER’s universal machines - productivity, stability, reliability, availability and precision.
If the customer or the application requires additional technologies to be integrated, HELLER can achieve this, following a detailed examination of technical feasibility, flexibly, swiftly and without any overengineering - even at a later time. The focus is always on per-piece costs, machining quality and process reliability.
CP: Basically, there are two different scenarios: first, the customer already has one or more HELLER products and is confronted with various requirements. This can happen as part of the continuous improvement process, where process chains and throughput times have to be shortened. Or the customer has received a major order, the per-piece costs of which could be reduced by integrating another process. Or it can be about replacing machines with other technologies, and the idea of cost-effectively integrating processes on the HELLER machine instead of buying a new one. These are just a few of the situations we encounter.
Application engineering then reviews the viability of retrospective process integration, allowing for the fact that the customer is meant to be familiar with this technology already. Secondly, the customer presents us with a specific application, where integration of a non-mainstream technology appears to make sense in terms of both quality and per-piece costs.
Whichever scenario, HELLER has a wealth of application engineering experience for providing the customer with an optimal machine and process solution, also in the form of a multitasking concept. HELLER deliberately speaks of a ›smart technology mix‹. For a complete machining operation, the customer pays only for what is actually required. As a result, a very efficient and direct return on the additional investment can be achieved.
CP: Generally speaking: when a HELLER machine is shipped to the customer, the control software required for efficient programming and production is integrated onboard. In some cases, this includes cycles developed by HELLER for grinding complex contours such as control curves, for example. With the C series mill/turning centres, HELLER has implemented not only all cycles for turning, but also a proprietary balancing cycle for reliable workpiece clamping into the control’s user interface. Then there is the comprehensive range of aftersales services which permits universal machines to be retrofitted at a later time. The best example here is the HELLER out-facing head system, which allows the customer to apply more efficient machining strategies for producing complex contours.
CP: This aspect is very important for the customer as part of an investment decision made for a particular situation and no less important for HELLER in terms of a certain technological uniqueness. HELLER purposely makes the ›Lifetime Productivity‹ of its machines a subject of discussion.
For two reasons: many customers certify HELLER machines as providing longer productivity than the competition. This requires in turn that HELLER remains a partner to its customers over the machine’s entire service life, so that the machine can be modified to suit changed framework conditions. The numerous optimisation and upgrade packages available constitute an essential element of the HELLER philosophy.
The robust mechanical construction of HELLER machines guarantees long-term precision far beyond the depreciation period. However, after a service life of many operating hours, a machine tool’s production performance and precision often no longer satisfy current requirements.
With HELLER Retrofit, HELLER Services offers an original factory overhaul to restore our customers’ existing machines to state-of-the-art condition. HELLER Services staff provide tailored service solutions and custom-made service packages to ensure optimum productivity and maximum availability of the machines –anywhere in the world, on site and around the clock. A factory overhaul with HELLER Retrofit pays dividends, especially for older machines sold by HELLER Automotive and HELLER Machines. Not only will we restore the performance of the machines, we will also increase productivity by up to 20%.
The machines covered include our innovative and comprehensive production solutions for powertrain, driveline and chassis components, marketed under the name HELLER Automotive. They provide a high level of productivity, contributing to minimal per-piece costs. Moreover, HELLER Services provides support for machines of the HELLER Machines brand. Just like the machines from our current portfolio they provide a wide range of options in proven quality.