Every time he goes to fight the Hulk,he usually losses. Will there be one that can stand a decent fight for a while?

For a while. Then Hulk will get mad and suddenly high power repulsors mean NOTHING.

Hasn't iron man recently defeated Hulk in his normal armour O.o

No, Marvel will continue to write Tony Stark as an idiot that will build a giant armor to get into a fist fight with Hulk no matter how futile that has been proven to be. Stark could easily develop an armor with heavy long range firepower and wear down Hulk and win 100% of the time by default. Logic goes out the window when someone wants to draw a brawl.

Its not just Hulk getting stronger it's him being able to heal quick too, its hard to beat somebody in a fist fight that will eventually get stronger then you and recover from everything you do in a matter of seconds. I agree with an earlier post, you figured by now Tony would have come up with a sniper armor by now or something, thought he was smart lol