| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve the internal cooling efficiency of an operation execution means by transmitting the air exhausted from an air outlet through the 1st and 2nd exhaust ducts and then exhausting the air to the outside through an air hole. SOLUTION: A 2nd exhaust duct 63 having an almost same shape as a 1st exhaust duct 58 of a power circuit 48 is placed at the rear end part of the right side part 63A of a shielding cover 61. When a case cover body is attached to a case main body, the opening end of the duct 63 is connected to an opening end 58A of the duct 58. That is, both ducts 58 and 63 function as a single piece of exhaustion duct (combined exhaust duct) having the through-hole parts 58B and 63B when the case cover body is attached to the case main body. Thus, the air that is forcibly exhausted from a 2nd air outlet 57 of the circuit 48 is transmitted through the hole parts of the combined exhaust duct and then exhausted to the outside through the hole part of the cover 61 and then a 2nd air hole 60 of the right wall.</p> |
