Cast plastic cylinder head cover with integral lubricating channels

摘要

A process is claimed for manufacturing a cast plastic cylinder head cover(1) with one or more integral lubricating channels(2-5) which extend along at least part of the length of a cam shaft(17) when the cover is located on a cylinder head(12). The cover(1) wall thickness in the area of the lubrication channels(2-5) is greater than the remaining wall areas and the casting tool includes a gas supply inlet near the lubricating channels and one or more outlets for plastic offset from the gas inlet. Molten thermoplastic is fed to the mould and solidifies in the thinner areas and the areas around the lubricating channels(2-5) in contact with the tool wall. Plastic in the centre of the thicker sections of the cover wall remain fluid and compressed gas fed via the gas inlet(6) into the fluid plastic forces this out through outlets(7,8) leaving hollow chambers which act as the lubricating channels(2-5). A cylinder head cover produced by the said gas injection process is claimed and is a one piece cast plastic component with one or more integral lubrication channels which include curved sections.