JP3709295B2 - Blower fan slip prevention structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an anti-spinning structure for a blower fan, and more particularly to an anti-spinning structure for a blower fan using an internal combustion engine as a drive source.
[0002]
[Prior art]
Conventionally, as shown in FIG. 6, as a vacuum cleaner used for cleaning, for example, fallen leaves, pieces of wood, garbage, etc., as shown in FIG. 6, a main body 1 is a small air-cooled two-cycle gasoline engine 2 as a prime mover, The recoil starter 3, the fuel tank 4, the fan casing 5, and the like are integrally formed. A suction pipe 6 is detachably connected to the suction port 5 a of the fan casing 5, and the blowout port 5 b of the fan casing 5 is blown out. A pipe 7 is detachably connected, and a dust bag 8 having appropriate air permeability is provided at the leeward (blowout) end of the blowout pipe 7. In the figure, reference numerals 9 and 10 denote operation handles held by an operator.
[0003]
Although not shown in the figure, a cutter 11 and a blower fan 12 that are rotated via the output shaft 13 of the internal combustion engine 2 are disposed in the fan casing 5 (Japanese Patent Laid-Open No. 8). No. 13436 and US Pat. No. 5,245,726). The fan casing 5, the suction pipe 6, the blowout pipe 7, the blower fan 12, and the like are formed of plastics for weight reduction.
[0004]
[Problems to be solved by the invention]
In the vacuum cleaner, when the internal combustion engine 2 is started, the cutter 11 and the blower fan 12 are rotated via the output shaft 13 of the internal combustion engine 2, and sucked objects such as fallen leaves are sucked into the suction pipe 6, First, it is pulverized by the cutter 11 and further stored in a dust bag 8 provided at the leeward (blowout) end of the blowout pipe 7 connected to the blowout port 5b of the fan casing 5 by the function of the blower fan 12. .
[0005]
However, if the use is continued, buckling, deformation, etc. occur in the tightening boss portion 16 of the blower fan due to the impact caused by the contact between the blower fan and the suction object sucked into the fan casing by the rotation of the blower fan, There were problems such as blower fan spinning.
[0006]
The present invention has been made in view of the above circumstances, and relaxes the force applied to the tightening boss portion of the blower fan to prevent buckling, deformation, etc. of the tightening boss portion of the blower fan, An object of the present invention is to provide a blower fan idling prevention structure with improved durability of the blower fan mounting portion.
[0007]
[Means for Solving the Problems]
The present invention has been made in view of the above circumstances, and is provided with a concave portion adapted to an engaging convex portion provided on a magnet rotor attached to an output shaft of an engine, on a reinforcing annular rib portion formed on a back surface portion of a blower fan. The fitting recess is fitted to the engaging projection and the blower fan is fixed to the output shaft. Preferably, the fitting recess is formed at equal intervals over the entire circumference of the reinforcing annular rib. It is what.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 is a longitudinal sectional view of an essential part of a vacuum cleaner to which a blower fan anti-spinning structure according to the present invention is applied, FIG. 2 is an enlarged longitudinal sectional view of a blower fan, and FIG. 3 is an illustration of a reinforcing annular rib portion on the back of a blower fan. FIG. 4 is a front view of the magnet rotor, FIG. 5 is a cross-sectional view taken along the line V-V of FIG. 4, and FIG. 6 is a perspective view of the vacuum cleaner. In the blower fan idling prevention structure according to the present invention described with reference to FIGS. 1 to 5, the same parts as those of the vacuum cleaner shown in FIG.
[0009]
A cutter 11 and a blower fan 12 that are rotated via a crankshaft 13 that is an output shaft of the internal combustion engine 2 are disposed in the fan casing 5 of the main body 1.
[0010]
The vacuum cleaner does not require a centrifugal clutch mechanism, but in this embodiment, the crankshaft 13 of the internal combustion engine 2 has a clutch shoe mounting boss 14 that also serves as an air cooling fan of the internal combustion engine 2. The rotor 15 is attached.
[0011]
Further, as shown in FIGS. 1 and 2, an appropriate number of reinforcing annular rib portions 17 and 18 are usually provided on the back surface of the blower fan 12 in order to prevent the blower fan 12 from turning over and to be reinforced. The radial ribs 26 and 27 are formed by integral molding.
[0012]
In the present embodiment, the columnar clutch shoe mounting boss 14 used as an anti-rotation engaging convex portion is formed on the inside of the reinforcing annular rib portion 17 formed integrally with the back surface portion of the blower fan 12. A matching recess 19 is formed.
[0013]
In one embodiment of the drawing, the reinforcing annular rib portion 17 is formed in a waveform having equal intervals over the entire circumference, and each of the inner peripheral surfaces of the waveform forming portion is engaged with the clutch shoe mounting boss 14. The fitting recess 19 is configured. Therefore, when the blower fan 12 is attached to the crank 13 of the internal combustion engine 2, there is no need to consider its directionality, and the fitting recess 19 can be easily fitted to the clutch shoe mounting boss 14. .
[0014]
It should be noted that an appropriate number of the fitting recesses 19 of the clutch shoe mounting boss 14 formed on the back surface of the blower fan 12 may be provided in conformity with the number of the clutch shoe mounting bosses 14. You may form in the position latched on the outer peripheral surface of the rib 17. FIG.
[0015]
In the above configuration, the fitting recess 19 formed on the back surface of the blower fan 12 is fitted to the clutch shoe mounting boss 14 of the magneto rotor 15 mounted on the crankshaft 13 of the internal combustion engine 2, A blower fan 12 is fixed to the crankshaft 13 of the internal combustion engine 2 so as not to change its position.
[0016]
In one embodiment, the relay drive shaft 20 extended from the magnet rotor 15 portion attached to the crankshaft 13 of the internal combustion engine 2 is provided with an inner washer 21, an outer washer 22 serving as a cutter, and a nut 23. The blower fan 12 is firmly tightened and fixed to the crankshaft 13 of the internal combustion engine 2. In the figure, 24 is a magnet (for convenience of explanation, the position is changed and shown in FIGS. 1 and 5), and 25 is a power generating coil for ignition.
[0017]
According to the vacuum cleaner having the blower fan anti-spinning structure having the above-described configuration, the blower fan 12 is effectively prevented from idling due to buckling, deformation or the like of the tightening boss 16 of the blower fan 12.
[0018]
That is, in the present embodiment, the fitting recess 19 formed in the reinforcing annular rib portion 17 on the back surface portion of the blower fan 12 has the magnet rotor 15 fixed to the crankshaft 13 of the internal combustion engine 2. Since it is adapted to the boss 14 for attaching the clutch shoe, the force applied to the fastening boss portion 16 of the blower fan 12 is alleviated, the buckling and deformation of the fastening boss portion 16 and the idle rotation of the blower fan 12 are achieved. Is reliably prevented, and at the same time, the durability of the tightening boss portion 16 is improved.
[0019]
When diverting an internal combustion engine designed to attach a recoil starter to the magnet rotor 15 side, the recoil starter centrifugal clutch pawl mounting pole portion is used as an engaging convex portion. can do.
[0020]
【The invention's effect】
According to the present invention, the buckling and deformation of the tightening boss portion of the blower fan relative to the output shaft of the internal combustion engine and the idle rotation of the blower fan can be reliably prevented, and the durability of the tightening boss portion of the blower fan is improved. Can do.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of an essential part of a vacuum cleaner to which a blower fan idling prevention structure according to an embodiment of the present invention is applied.
FIG. 2 is an enlarged longitudinal sectional view of the blower fan shown in FIG.
FIG. 3 is a front view of a reinforcing rib portion on the back side of the blower fan.
FIG. 4 is a front view of a magnet rotor.
5 is a cross-sectional view taken along line VV in FIG.
FIG. 6 is a perspective view showing an entire example of a vacuum cleaner.
[Explanation of symbols]
2 Internal combustion engine 12 Blower fan 13 Output shaft (crankshaft)
14 Clutch shoe mounting boss (engagement projection)
15 Magnet rotor 17 Reinforcing annular rib 19 Fit recess

Claims (2)

Engaging protrusions (15) provided on the magnet rotor (15) attached to the output shaft (13) of the internal combustion engine (2) on the reinforcing annular rib (17) formed on the back surface of the blower fan (12). 14), a fitting recess (19) is formed, the fitting recess (19) is fitted to the engaging projection (14), and the blower fan (12) is fixed to the output shaft (13). Blow fan anti-spinning structure. 2. The blower fan anti-spinning structure according to claim 1, wherein the fitting recesses (19) are formed at equal intervals over the entire circumference of the reinforcing annular rib portion (17).

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