Shutting down of minecraft

Dear Minecraft,

I have like a little problem who i doensnt find in the forums itl like a little lag.
Eveytime i play minecraft for like an hour it just shut down the game!?
I had that already from the beginning it just shut down witout a warning or something and thats like every hour so it doesnt matter if its on sigleplayer or on a server but on survival games it does !! If you are like the best and then it shuts down its really annoying (like me ) so do you have a solution for me?

Greetings, XxJonTheBestxX