Backpack-type air blowing working machine

Abstract

Disclosed is a backpack-type air-blowing working machine in which a volute casing incorporating a centrifugal fan configured to be driven by an electric motor is assembled in an upstanding manner to a backpack frame to be carried on the back of an operator using shoulder straps during use. The backpack-type air-blowing working machine includes a rechargeable battery pack connected to the electric motor and detachably attached to the backpack frame, such that a position of the center of gravity of the backpack-type air-blowing working machine as viewed from the rear thereof is located below a rotation axis of the centrifugal fan, and a position of the center of gravity of the backpack-type air-blowing working machine as viewed from the side thereof is located forward of a rear end of the volute casing.

1 . A backpack-type air-blowing working machine comprising:
 a backpack frame having at least a back plate portion conformable to the back of an operator, the backpack frame being configured to be carried on the back of the operator through the back plate portion using shoulder straps;   a volute casing mounted to the backpack frame at a position rearward of the back plate portion, in such a manner that a center of a volute is set in a direction intersecting a planar direction of the back plate portion;   a centrifugal fan rotatably supported within the volute casing;   an electric motor assembled to the volute casing and operable to rotate the centrifugal fan; and   a rechargeable battery pack attached to the backpack frame and operable to feed electric power to the electric motor,   wherein the backpack-type air-blowing working machine is configured such that a position of the center of gravity of the backpack-type air-blowing working machine as viewed from a rear thereof is located below a rotation axis of the centrifugal fan, and a position of the center of gravity of the backpack-type air-blowing working machine as viewed from a side thereof is located forward of a rear end of the volute casing.   
     
     
         2 . The backpack-type air-blowing working machine as recited in  claim 1 , wherein the backpack frame further has a support rack portion provided to extend rearwardly from a lower end of the back plate portion and located just beneath the volute casing, and wherein the battery pack is assembled onto the support rack portion in such a manner as to be disassemblable in a forward-rearward direction. 
     
     
         3 . The backpack-type air-blowing working machine as recited in  claim 1 , wherein the backpack frame further has a support rack portion provided to extend rearwardly and horizontally from a lower end of the backpack frame and located just beneath the volute casing, and the battery pack is composed of a plurality of rechargeable battery packs, each of the plurality of rechargeable battery packs is connected to the electric motor, and each of the plurality of rechargeable battery packs is assembled onto the support rack in a manner that allows for disassembly of the respective battery pack from the electric motor in a forward-rearward direction. 
     
     
         4 . The backpack-type air-blowing working machine as recited in  claim 2 , which comprises a cover covering the volute casing, the cover being detachably attached to the backpack frame in such a manner that the battery pack assembled onto the support rack portion is located outside the cover. 
     
     
         5 . The backpack-type air-blowing working machine as recited in  claim 1 , wherein the volute casing is configured such that one of opposite ends thereof in a rightward-leftward direction has a blowing tube portion formed to blow out air therefrom and communicated with and connected to a blowing duct, and the other end thereof in the rightward-leftward direction has a joint with respect to the battery pack. 
     
     
         6 . The backpack-type air-blowing working machine as recited in  claim 5 , wherein the battery pack is composed of a plurality of rechargeable battery packs each of the plurality of rechargeable battery packs is connected to the electric motor, the plurality of rechargeable battery packs being arranged on one side of the back plate portion of the backpack frame in the rightward-leftward direction to extend in an upward-downward direction, and attached to the back plate portion in such a manner that allows for disassembly of the respective battery pack from the electric motor in a forward-rearward direction. 
     
     
         7 . The backpack-type air-blowing working machine as recited in  claim 2 , which is configured such that, when the backpack-type air-blowing working machine is placed on a horizontal mounting surface such that the back plate portion is in a standing posture, the backpack-type air-blowing working machine stands by itself while keeping the back plate portion in the standing posture, in both of a state in which the battery pack is attached to the support rack portion and a state after the battery pack is detached from the support rack portion. 
     
     
         8 . The backpack-type air-blowing working machine as recited in  claim 1 , which is configured such that the position of the center of gravity of the backpack-type air-blowing working machine as viewed from the rear thereof is located within a region extending from a center line of the backpack frame in each of a rightward direction and a leftward direction, by a length of 10% of a maximum width of the backpack frame in the rightward-leftward direction. 
     
     
         9 . A backpack-type air-blowing working machine in which a pair of volute casings arranged side-by-side in a forward-rearward direction and incorporating, respectively, a pair of centrifugal fans each configured to be driven by a respective one of a pair of front and rear electric motors arranged in a coaxial relation are assembled in an upstanding manner to a backpack frame to be carried on the back of an operator using shoulder straps during use, the backpack-type air-blowing working machine comprising:
 a pair of rechargeable battery packs connected, respectively, to the electric motors, wherein the rechargeable battery packs are detachably attached to the backpack frame, such that a position of the center of gravity of the backpack-type air-blowing working machine as viewed from the rear thereof is located below a rotation axis of the centrifugal fans, and a position of the center of gravity of the backpack-type air-blowing working machine as viewed from the side thereof is located forward of a rear end of the volute casing,   and wherein airflows blown out from respective blowing ports of the volute casings according to rotation of the centrifugal fans during operation of the electric motors are merged together and discharged from a blowing duct.   
     
     
         10 . A backpack-type air-blowing working machine in which a pair of upper and lower volute casings each incorporating a centrifugal fan configured to be driven by an electric motor are assembled in an upstanding manner to a backpack frame to be carried on the back of an operator using shoulder straps during use, the backpack-type air-blowing working machine comprising:
 a rechargeable battery pack connected to each of the electric motors, wherein the rechargeable battery pack is detachably attached to the backpack frame, such that a position of the center of gravity of the backpack-type air-blowing working machine as viewed from the rear thereof is located below an output shaft of the electric motor for driving the centrifugal fan in the upper volute casing, and a position of the center of gravity of the backpack-type air-blowing working machine as viewed from the side thereof is located forward of rear ends of the pair of upper and lower volute casings,   and wherein airflows blown out from respective blowing ports of the volute casings according to rotation of the centrifugal fans during operation of the electric motor are merged together and discharged from a blowing duct.