I hope it's no too late.
You can find Chilean laws here:
http://www.bcn.cl/portada.html
This link has a 24 pages long PDF that has everything refering to edged weapons laws in Chile:
http://www.bcn.cl/publicadores/pub_uaprol_doc/listado/detalle.php?id=22
If you don't understand Spanish, I'll try to summarize it for you.
Edged weapons in Chile don't have specific laws, like in Argentina, firearms are given a lot of attention but knives aren't. They fall under a general category of "weapons". You're not supossed to carry "weapons" (defined by law as "any object or instrument used to attack or defend", in Chile; and as "anything that increases offensive power" in Argentina). The problem is that with these wide definitions, every single item known to man can be considered a weapon.
Article 10 of Law number 12.927 says that "the use of cutting, piercing or bludgeoning weapons is prohibitted to any person" that is not a soldier or LEO, unless they have permission from the proper authorities. It's punishible with minimum prison time or a fine of up to 1/4 of your montlhy income. As you would expect, producing a knife in a fight has all sorts of legal consecuences, but luckily that isn't the case here.
Law professors in Chile say that intent is the key thing here, because the law stresses the action and not the object (the important thing is that you USE the object as a weapon, not that it was in itself capable of causing harm). The "natural" use of the object isn't punished (a hunting knife while hunting, for instance).
There are no blade length limits as far as I know, or specific knives not allowed (like autos, or things like that).
Although I live in Argentina I spend quite a bit of time each year in Chile and have friends who live there. Form our collective experience this is the advice I can give you for carrying knives there, most of it is common sense:
-Just to be on the safe side, try to avoid knives that are too aggresive looking. People in general and LEOs in particular are more prone to have a bad reaction to a black bladed tac knife than to a shiny folding hunter, regardless of blade size.
-If you're taking a big folder, carry a more sheeple-friendly SAK. Not only is it a good backup, but it will be more suitable for some places than a larger knife.
-Attitude is what LEOs look for, a well behaved, polite person is unlikely to be bothered. Even if for some reason a policeman's attention is called to your knife, if you act like a normal, well intentioned person he'll probably just tell you to be more discreet.
I've carried all sorts of knives in Chile. Cities require more discretion, as in the case in almost every country, but people really don't seem to mind unless you're threatening somehow.
Finally, I'm no expert on laws, so you should check with the Chilean embassy (
http://www.chile.ca/)
