Hand-held engineering drill cooling system

The utility model relates to a cooling way of water pipe of hand-held engineering driller. A pipe joint (6) is installed on the gear box casing of the hand-held engineering driller; one end of the metal pipe (3) is connected with the pipe joint (6); another end through the centre of the main output axis (4) of the gear box and parallels with the drill joint (5). After the cooling water entering into the pipe joint (6) by a water valve (2), the cooling water along the metal pipe (3) comes to the drill joint (5) and enters the inner wall of the drill and flows to the edge of the drill for cooling. The utility model gets rid of the water sleeve and the water seal structure for avoiding the water leakage generated from the abrasion of water seal of water sleeve and main axis.