Minimal Quantity Lubrication (MQL) cuts engine block production costs

On its in-line engine block production facility at Honsel AG, nine machining centres with a total of 17 spindles are fed by bielomatik 2-channel MQL systems. Bielomatik believes their system, although difficult to measure, could be delivering up to, or better than, a 15 per cent reduction in production costs; certainly Honsel is very impressed with the savings.

Honsel specialises in the development and production of light-metal products for the automotive sector such as engine, transmission, suspension and bodywork. Introduction of the bielomatik 2-channel minimal quantity lubrication (MQL) systems ensures delivery of precisely controlled minute quantities of lubrication to the cutting tip. This 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. 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 2-channel system's pre-processes the air/lubricant mixture before delivery. Metering of too much lubricant during the tool change is now precluded by the 2-channel design, its spindle containing 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. Karsten Gutschker, responsible for production management for in-line engines at Honsel, said: "We save considerable amounts of waste water together with the cost of processing this water." A significant saving when you consider washing alone accounts for 4.5 per cent of the total machining costs for the line process. The company is also finding that only one washing cycle is sufficient for the 3,000 engine blocks produced each day. 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. Low waste disposal costs and minimal oil consumption are on an average less than 3 ml per component. Add these factors to other cost saving elements of machine cutting with MQL and you have introduced a lubrication system that could pay for itself within months, as opposed to years. Another problem, when lubrication is not optimised, is that 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 2-channel minimal quantity lubrication. The production described above still has accuracy (tolerance) of 0.02 mm with a distance of 450 mm, or 0.010 mm for some diameters. The 2-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, whilst their auto-lube series takes the guess work out of routine maintenance thus averting machine failure.