Casing structure for electrical and mechanical units

Claim 1

A casing structure for accommodating electrical and mechanical units including heat and sound sources, comprising: (a) a first, a second and a third compartment, each having respective air inlets and outlets, said first compartment being connected to said second compartment, which is connected in turn to said third compartment, through respective connecting passages including their air outlets and inlets to constitute an air flow passage through the first, second and third compartments arranged in series; (b) a heat source and a sound source arranged in said intermediate, second compartment; (c) a fourth compartment positioned in the connecting passage between said first and second compartments; (d) an air cooling fan disposed in said fourth compartment so as to be in the vicinity of said heat source in said second compartment, wherein cooling air is circulated through said air flow passage from said first compartment via said second compartment toward said third compartment and said heat source is compulsorily cooled by said cooling fan; (e) a first casing unit for containing said first and second compartments; and (f) a second casing unit for containing said third and fourth compartments, wherein said second casing unit is connected to said first casing unit so as to be able to open and close with respect to said first casing unit.