The hot air capture part
10 is an device for capturing and collecting the Joule heat generated by the heat generation part
2 and, as shown in
FIG. 4, a substantially cylindrical cover
7, which has a hot air exhaust pipe
7
a, is provided so as to cover the top face of the hot air capture plate
6, which is made of aluminum, in which a plurality of hot air flow passage holes
6
a have been made. In the present embodiment, the hot air passage holes
6
a are arranged with the holes in a spiral, and a strip-shaped guide
9 is provided in an upright manner in a spiral shape, following this arrangement. A blower (not shown in the figure) is connected to the hot air exhaust pipe
7
a, via a duct
8, and the Joule heat generated by the heat generation part
2 is suctioned thereby and collected in the form of hot air.