A die casting (mould) client needed support to prevent moulds parting during the die casting process, causing flashing around the mould line. The client asked Helipebs to design and deliver a locking type hydraulic cylinder to firmly hold two moulds together during the die casting process.
The challenge
The client, a major die caster, was having problems with a mould set up. During the die casting process the moulds were parting slightly, causing unwanted flashing around the casting mould line. This was wasting metal, resulting in extra work being required on the castings and so increasing costs. The client wanted a cost effective solution that would still fit within their space envelope. Any solution would need to use a single hydraulic cylinder in line with their existing set up.
The solution
We identified the problem was caused by compression of the hydraulic fluid in the system which forced the holding cylinder to move back fractionally during the moulding process. A larger hydraulic cylinder could have been used to give greater resistance to the moulding force, but space constrains prevented this. The Helipebs engineering team calculated that if the amount of hydraulic fluid being compressed could be reduced, the system would become ‘stiffer’ and prevent the moulds from parting. To achieve this we designed a hydraulic cylinder of the same bore size, but with the addition of a pilot operated check valve on the full bore area which isolated a smaller volume of oil directly in the cylinder, almost eliminating the compression and preventing excessive flashing.
Key points
- Our extensive knowledge of hydraulics enabled us to come up with a cost effective and relatively simple solution; Helipebs can often offer delivery within 7 days for this type of solution
- We understood our customers’ needs and worked with them to provide a satisfactory and straight forward fix, based on a standard cylinder and check valve design
- The customer was happy with the results and has swapped out other cylinders for pilot operated versions on other moulds
- Whilst hydraulic cylinder lifetimes vary depending upon application, Helipebs hydraulic cylinders often exceed 20 years of service with no issues
