The 32-year-old has struggled to hold down a regular starting slot at Loftus Road since joining from Derby County in 2010.
As a result, the R's have allowed the centre-forward to make the temporary switch in order to get some minutes on the pitch.
Speaking about his latest acquisition, manager Chris Powell admitted that he was pleased to have signed someone with a vast experience of playing in the Championship.
"I'm really pleased to have Rob on board and look forward to working with him," Powell told the club's official website.
"With the squad we have we do have one or two players that have played at this level before and a couple have played Premier League, but you do need to have that Championship know-how week in, week out and Rob will give us that.
"He's done well at this level before and I think he will show people that he's a good player and we know that he comes here with maybe a point to prove to people. He just comes in and will work hard and I'm sure he will do well."
Hulse, who has been given the number 29 shirt, has gone into the squad for tomorrow's encounter against Watford.