Axial-flow fan

Abstract

An axial-flow fan includes a hub and a plurality of blades integrally resin-molded to the hub at a plurality of joints, The plurality of blades are formed so as to project from an outer perimeter edge of the hub. Each joint has at least one first blade thinned-out part formed so that at least one radial rib extending radially toward an outer perimeter side is formed.

1 . An axial-flow fan comprising:
 a hub; and   a plurality of blades integrally resin-molded to the hub at a plurality of joints therebetween, the plurality of blades being formed so as to project from an outer perimeter edge of the hub,   each joint having at least one first blade thinned-out part formed therein so that at least one radial rib extending radially toward an outer perimeter side is formed.   
     
     
         2 . The axial-flow fan according to claim I, wherein
 the at least one rib of each joint includes a plurality of radial ribs disposed in a circumferential direction.   
     
     
         3 . The axial-flow fan according to  claim 1 , wherein
 each radial rib extends along a straight line extending radially toward the outer perimeter side from an axial center of the hub when viewing the hub and the blade from an axial direction.   
     
     
         4 . The axial-flow fan according to  claim 1 , wherein
 each joint further includes
 a front edge rib continuing on a front edge of the blade in a portion further toward a front edge side of the blade the at least one radial rib; and 
   a second blade thinned-out part formed circumferentially between the front edge rib and the at least one radial rib, with the second blade thinned-out part being larger than the first blade thinned-out part.   
     
     
         5 . The axial-flow fan according to  claim 2 , wherein
 the radial ribs of each joint are equidistantly disposed relative to each other in the circumferential direction.   
     
     
         6 . The axial-flow fan according to  claim 1 , wherein
 each blade includes an indented part formed on a rear edge side thereof, with the indented part indented toward a front edge side of the blade from the rear edge of the blade; and   the first blade thinned-out part is positioned further toward the front edge side of the blade than the indented part when viewing the hub and the blade from an axial direction.   
     
     
         7 . The axial-flow fan according to  claim 2 , wherein
 each radial rib extends along a straight line extending radially toward the outer perimeter side from an axial center of the hub when viewing the hub and the blade from an axial direction.   
     
     
         8 . The axial-flow fan according to  claim 2 , wherein
 each joint further includes
 a front edge rib continuing on a front edge of the blade in a portion further toward a front edge side of the blade the at least one radial rib, and 
 a second blade thinned-out part formed circumferentially between the front edge rib and the at least one radial rib, with the second blade thinned-out part being larger than the first blade thinned-out part. 
   
     
     
         9 . The axial-flow fan according to  claim 2 , wherein
 each blade includes an indented part formed on a rear edge side thereof, with the indented part indented toward a front edge side of the blade from the rear edge of the blade; and   the first blade thinned-out part is positioned further toward the front edge side of the blade than the indented part when viewing the hub and the blade from an axial direction.   
     
     
         10 . The axial-flow fan according to  claim 3 , wherein
 each joint further includes
 a front edge rib continuing on a front edge of the blade in a portion further toward a front edge side of the blade the at least one radial rib, and 
 a second blade thinned-out part firmed circumferentially between the front edge rib and the at least one radial rib, with the second blade thinned-out part being larger than the first blade thinned-out part. 
   
     
     
         11 . The axial-flow fan according to  claim 3 , wherein
 the radial ribs of each joint are equidistantly disposed relative to each other in the circumferential direction.   
     
     
         12 . The axial-flow fan according to  claim 3 , wherein
 each blade includes an indented part formed on a rear edge side thereof, with the indented part indented toward a front edge side of the blade from the rear edge of the blade; and   the first blade thinned-out part is positioned further toward the front edge side of the blade than the indented part when viewing the hub and the blade from the axial direction.   
     
     
         13 . The axial-flow fan according to  claim 4 , wherein
 the radial ribs of each joint are equidistantly disposed relative to each other in the circumferential direction.   
     
     
         14 . The axial-flow fan according to  claim 4 , wherein
 each blade includes an indented part formed on a rear edge side thereof, with the indented part indented toward the front edge side of the blade from the rear edge of the blade; and   the first blade thinned-out part is positioned further toward the front edge side of the blade than the indented part when viewing the hub and the blade from an axial direction.   
     
     
         15 . The axial-flow fan according to  claim 5 , wherein
 each blade includes an indented part formed on a rear edge side thereof, with the indented part indented toward a front edge side of the blade from the rear edge of the blade; and   the first blade thinned-out part is positioned further toward the front edge side of the blade than the indented part when viewing the hub and the blade from an axial direction.