Automatic lubrication lowers production costs by 15%

Jim Hughes, UK Sales Manager at Bielomatik, outlines how Honsel has benefited from the MQL system: "It has been difficult to evaluate the total cost savings being derived on the engine block production facilities of Honsel AG in Meschele, Germany, following the introduction of our two-channel minimal quantity lubrication (MQL) systems, but the company is well impressed. The precisely controlled delivery of minute quantities of lubrication to the cutting tip means cleaner swarf that can be directly recycled, machine parts require substantially less or no cleaning at all to remove potential oil contaminant, and a much cleaner working environment has been created where overall workshop cleaning has been reduced to once a week."

Honsel specialises in the development and production of metal products for the automotive sector - such as engine, transmission, suspension and bodywork. On its in-line engine block production facility, which handles around 3000 units per day, nine machine centres with a total of 17 spindles are fed by Bielomatik two-channel MQL systems. Bielomatik estimates that its system could be delivering up to or better than a 15 per cent reduction in production costs.

Benefits of two-channel system

On production lines where regular tool change takes place the Bielomatik lubrication system offers a real plus factor since the lubricant is transported on an 'air' carrier directly to the cutting tip of the tool within 0.1 seconds. At Honsel this takes place on the multi-spindle MAG Specht 550 Duo, where the two-channel systems pre-process the air/lubricant mixture before delivery. Metering of too much lubricant during the tool change is now precluded by the two-channel design; its spindle contains only pure air and it is therefore impossible for oil to reach the mounting surfaces of the tool holder. The versatility that comes with this exact metering system ensures precise lubricant delivery, whether for small-diameter tools or more robust operations such as thread formers.

Honsel is proud of its environmental status. A spokesperson for the company succinctly cited one of the benefits of the Bielomatik MQL system when he said: "We have got contamination completely under control. Engine blocks either go through the basic cleaning process specifically agreed with the customer or do not require any cleaning whatsoever."

Karsten Gutschker, responsible for production management for in-line engines, added: "We save considerable amounts of waste water, together with the cost of processing this water." Asked what the direct impact of this had on costs is, he gave this response: "Washing alone accounts for 4.5 per cent of the total machining costs for the line process."

Where the cleaning of parts can now be omitted, any associated penetration of heat into the workpiece has automatically been eliminated. This means pre-cooling of cleaned parts for leak testing has becomes unnecessary. The company is also finding that only one washing cycle is sufficient for the 3000 engine blocks produced each day.

Rapid payback

The omission of or limited requirement for cleaning alone offers enormous benefits in terms of overall production times and expenditure and enables Honsel's in-line engine department to maintain an excellent environmental record. As well as benefiting from low waste disposal costs, there are savings in lubricants costs, as oil consumption is on an average less than 3ml per component. Add these factors to other cost-saving elements of machine cutting with MQL, and such a lubrication system could pay for itself within months.

Even after 17 shifts a week on the Honsel engine line, the dry chips are where they belong - in the chip container. If lubrication is not optimised, metal chips smeared with oil stick to die carriers, for example, leading to faults during machining, as, typically, hollow taper shanks may not be positioned correctly in the spindle since small chips impair the concentricity of the tools. This is a quality problem that does not arise with a cutting machine using two-channel minimal quantity lubrication. The production described above still maintains an accuracy (tolerance) of 0.02mm with a distance of 450mm, or 0.010mm for some diameters.

The two-channel MQL system deployed through the Honsel engine block production line is part of the Bielomatik MQL range of lubrication systems designed to cut machining costs and improve productivity, while the company's auto-lube series takes the guess work out of routine maintenance, hence averting machine failure.

Go to www.bielomatik.com/en/lubrication/mqlsystems/2337?pms=2337 for more information about the MQL system.