Renault’s hybrid project, Locobox, is becoming increasingly important due to the global discussion surrounding drive systems and the significant increase in sales figures. At the heart of this project is a hybrid transmission, which intelligently combines a combustion engine and electric drive, and is set to be used in the majority of the car models from the Renault Group. Renault regards this concept as extremely efficient since both drive systems can be operated simultaneously and regenerative systems can be used.
Renault’s Cléon plant, near to Rouen, and STA plant, close to Lille, are involved in the development and production of the hybrid transmission. And this is where the QUICKPOINT 3000 and JUMAT 3000 cylindrical grinding machines are used. QUICKPOINT and JUMAT are used as part of a line for transmission shafts, are loaded from above at Renault by a central loader and grind three different types of hybrid transmission shafts for this project.
Short cycle and changeover times
The targets for the cycle and changeover times are high. Olivier Gantier, Technical Leader for the Grinding department comments: “Production manages to output very high quantities with a low number of machine operators. One person looks after 10 machines. So we have to be able to retool the machines as quickly as possible. Changing the grinding wheels manually, for example, is out of the question.”
The JUNKER machines can handle these stringent requirements. As Olivier Gantier said: “These machines deliver short cycle and changeover times. The quality and precision is right and the accuracy is very high. On top of that, they enable flexible concepts to be implemented – we can grind up to three different parts without having to retool.” It is these high-quality attributes that impressed Renault. Other decisive factors included JUNKER’s many years of experience, reliable delivery times and excellent technical support.
Contact partners understand the French mindset
As a global player, JUNKER offers contact partners who speak the customer’s language. For Olivier Gantier, this provided further assurance of an effective collaboration: “This is very important for me. The Renault Group has its own specifications and requirements. Communication must run smoothly and this is easiest when it is in the local language.”
Prototype manufacture for the Renault Group
Prototype production takes place at the French main plant Cléon, where Renault have opted for the ZEMA NUMERIKA G 1500 Plus and the JUCRANK 6S 10-10. These two machines supply reference data for series production worldwide. The results then form the basis for global production at the Renault Group’s other sites. This means that the JUNKER reference machines set the standard for efficient production throughout the entire Group. The ZEMA NUMERIKA cylindrical grinding machine grinds flanges and journals for crankshafts in a single clamping set-up using corundum grinding wheels, while the JUCRANK non-cylindrical grinding machine machines the main and pin bearing in a single work step using CBN grinding wheels.
As Olivier Gantier said: “The ZEMA NUMERIKA rounds off JUNKER’s product portfolio perfectly. JUNKER uses CBN for grinding, while ZEMA uses corundum. JUNKER can supply machines for every grinding process.”
Flexible machines enable rapid changes
Machine flexibility is one of the key requirements at Renault. This is important during prototype development, for example, as Olivier Gantier explains: “When production begins, the geometry of the parts is not yet defined with precision, as this develops, we have to be able to respond to it with the machines.”
Thanks to their high level of flexibility and as changes can be implemented quickly, the JUNKER machines are suitable for a wide range of applications. This is important for the Technical Leader: “We need to be able to work on our current projects for 3 and 4-cylinder engines as well as projects to be planned for the future at Renault.” Maxime Piquel, a Senior Machine Operator with 16 years of experience, rates the JUNKER machines highly.
“Working with these machines is a really positive experience. They are easy to use and can be quickly adjusted when there are product changes. This makes my work so much easier.”
Ready for use quickly and continuously
As the machines are in operation around the clock at Renault, there are high requirements when it comes to servicing and production reliability. JUNKER offers a 24/7 premium service. In the event of repairs or servicing, all the machines are back up and running again very quickly, thanks to a central spare parts warehouse.
“Our experience with JUNKER Service has been very positive,” confirms Maxime Piquel, who works with the machine. “The teams are able to start looking for solutions right away. All the technicians are highly skilled and can provide rapid assistance. Not every machine manufacturer offers such continuous availability and quick response. This sets JUNKER apart.”
World market leader offers global support
“We are very pleased. Machine start-up runs well,” says Olivier Gantier. The Renault Group is already benefiting from this at other locations around the world such as Brazil, Russia and Portugal. The hybrid project Locobox is proof that the Renault Group is very pleased with the overall package provided by the JUNKER Group.