Power-operated air blowing work apparatus

Abstract

A power-operated air blowing work apparatus comprises: a volute casing including a centrifugal fan installed therein and having a front wall formed with an air intake aperture for sucking air from an atmosphere into the volute casing by the centrifugal fan; an engine mounted to the volute casing in a rear side of the volute casing and connected to the centrifugal fan for rotating the centrifugal fan; an engine casing covering the engine from behind the engine in the rear side of the volute casing, and an air suction passage communicating from inside the engine casing toward inside the front wall of the volute casing for drawing air in the engine casing toward inside the front wall of the volute casing.

What is claimed is: 
     
         1 . A power-operated air blowing work apparatus comprising:
 a volute casing including a centrifugal fan installed therein and having a front wall formed with an air intake aperture for sucking air from an atmosphere into the volute casing by the centrifugal fan;   an engine mounted to the volute casing in a rear side of the volute casing and connected to the centrifugal fan for rotating the centrifugal fan;   an engine casing covering the engine from behind the engine in the rear side of the volute casing, and   an air suction passage communicating from inside the engine casing toward inside the front wall of the volute casing for drawing air in the engine casing toward inside the front wall of the volute casing.   
     
     
         2 . A power-operated air blowing work apparatus as claimed in  claim 1 , wherein the engine casing is formed with an air intake opening for introducing air from an atmosphere into the engine casing, wherein the air suction passage draws the introduced air in the engine casing toward inside the front wall of the volute casing. 
     
     
         3 . A power-operated air blowing work apparatus as claimed in  claim 1 , wherein the volute casing has a rear wall formed with an air outlet aperture for directing a part of the air sucked into the volute casing through the air intake aperture to inside the engine casing through the air outlet aperture, wherein the air suction passage draws the directed air in the engine casing toward inside the front wall of the volute casing. 
     
     
         4 . A power-operated air blowing work apparatus as claimed in  claim 1 , wherein the engine casing is lined inside with a sound insulating member for inhibiting engine noise from leaking outside, wherein the sound insulating member is formed with a channel on the surface thereof confronting the engine casing, thereby constituting a part of the air suction passage between the engine casing and the sound insulating member. 
     
     
         5 . A power-operated air blowing work apparatus as claimed in  claim 1 , wherein the engine casing is lined inside with a sound insulating member for inhibiting engine noise from leaking outside, wherein the sound insulating member itself is provided with a cylindrical bore disposed therein to constitute a part of the air suction passage through the sound insulating member. 
     
     
         6 . A power-operated air blowing work apparatus as claimed in  claim 1 , wherein the air suction passage is formed from behind the volute casing, around outside the volute casing and toward inside the front wall of the volute casing.