the casting machines

[davide&golia]

Good morning to all,

I wanted to ask you a question to which I did not find answer in any corner of the web.
I hope therefore that someone of you, with certainly more experience than me in the field, can give me a hand or at least direct me to a path.

in die casting machines, how do they make the seal inside the injection chamber to avoid aluminum piping between the piston and the cylinder?

I thought of two solutions:

• realize a coupling with interference between piston and cylinder;
• apply seal bands similar to those for internal combustion engines.

in the first hypothesis, I think the interference varies very much since the working temperatures are of the order of 600°c.
In the second hypothesis, I think the problem can be the aggressiveness of aluminium at the above temperature, which would lead to a quick wear of the bands.

I hope someone can give me an opinion on this problem.

cordial greetings,
Davide matvelli.

 

[Camillo60]

post a little old however, the piston is generally made (pressoculate cold room) in berillious copper having a diameter slightly lower than the inner diameter of the container for what is enough to avoid gripping during
the operation. the piston is constantly cooled through the passage of water inside it.
considers that although liquid, the metal has its "viscosity" that prevents it from flowing into spaces less than a certain value and also during the first phase of injection the thrust is quite "delicate".

Camillus