PURPOSE: To permit the manufacture at a low cost, regulate the opening range of a door, and permit the automatic closure of the door by installing a spring for energizing the door in the closure direction and regulating the opening range of the door by the contact of the spring with a hinge pin when the door is opened.

CONSTITUTION: When a door 2 is opened and closed, an installation pin 8 draws a locus S. Further, a pulling coil spring 9 generates a deflection δ, and generates a pulling force, accompanied with the opening of the door 2. The door 2 is energized always in the closing direction by the above-described pulling force, and automatic closure is performed. Further, as for the pulling coil spring 9, when the door 2 is opened to a set angle α, a stopper 9a comes in contact with the base part of a hinge pin 6, and the opening of the door 2 over the above-described degree is prevented. Accordingly, a stopper part for regulating the opening position of the door 2 is formed from the hinge pin 6 and the pulling coil spring 9. Accordingly, the door 2 is regulated within a set opening range without specially installing a stopper. Further, the opening degree of the door 2 can be easily adjusted by changing the shape of the stopper 9a of the pulling coil spring 9.