Toyota has developed new aluminium casting technology for cylinder heads that uses liquid glass in place of sand and adhesive cylinder heads. This will help to reduce odour and smoke during production.
Toyota’s new aluminium casting process enables significantly thinner and more complex cooling water channels.
Toyota
Japanese car manufacturer Toyota has developed a new aluminium casting technology for cylinder heads. The process uses liquid glass, an inorganic material that is expected to be not only versatile but to reduce environmental pollution, too.The cooling water channels in cylinder heads are normally modelled from moulds made of sand and adhesive, explains Toyota. However, the organic substance phenolic resin is used as an adhesive in the manufacture of these moulds, known as cores, and produces strong odours and smoke during casting. This requires factories to adopt costly countermeasures that take up a lot of space.
No vapour is produced when inorganic materials are used as adhesives. There have, however, been significant limitations to modelling cores in this way up to now. Nevertheless, thin and complex cooling water channels are vital to improving cooling capacity and engine performance, according to Toyota. It has also not been possible until now to reuse the sand used in the process.
Thin cooling water channels now possible
The new process aims to solve this problem by using liquid glass, an inorganic material. Toyota says that this reduces odours to below a hundredth of the normal concentration level, which in turn drastically reduces the need for air pollution control measures at production facilities. In addition, the use of tensides creates a foam-like consistency which improves the fluidity of the sand, enabling significantly thinner and more complex cooling water channels in cylinder heads. The sand can also be reused multiple times. The lower processing temperature could reduce CO2 emissions by more than a half in comparison to conventional methods.