I'd like to know how I can add something like a hinge or some other device
on a door that will make it close on its own without anyone pushing/pulling it closed.

The situation is this: I have a lot of people that come in and out of my room and they often don't
or forget to close the door. I'm having to get up out of my seat and walk over to the door 20-50 times a day doing this and it's getting very annoying. So I'm interested in doing something to the door so that it will just swing closed on its own. I'd imagine it would require something like a very strong hinge with thick bent coil/wire that will always force the door to close when no pressure is applied to open it. I just don't know what exactly
it's called or looks like.

Thanks.

 

It's called a self closing hinge. Google it. Just replace one or two of the exiting hinges and tighten as needed. Being in Korea, you'll have to check around over there for availability.

 

There are hydraulic door closers which you've seen on commercial doors. They also make smaller sizes for lighter residential doors. They are nice because they are spring loaded to close the door but also have a hydraulic damper to slow the door so it doesn't slam. Then there are self closing hinges like Gunguy mentioned. They are simple spring hinges that can be set to either open or close the door. They are small and inexpensive but if set too strong can slam the door.

 

When the kids were little I installed one like this on the outside door and it worked well to keep the door closed and the dogs inside.

https://www.doityourself.com/forum/a...1&d=1520612432

 

Similar to what Vic describes are self closing hinge pins like this:

Hinge Pin Door Closer: Model# N208-033 | True Value

Just replaces one or more hinge pin instead of entire hinge.

Vic, where did you get "Korea"?

 

I forgot to mention, the door I installed this had spring hinges but they didn't have enough umph to close and latch the door where as the hydraulic closer did!

 

Prior posts...verified via IP.

 

Thanks for the replies!
I decided to go for this one:
https://www.amazon.com/Spring-Closer...ng+door+closer

It doesn't require any nailing, hammering, etc. Simply attach/slide it on to the door hinge.
I'll give it a try once it arrives and see if it's any good.

Thanks.