JPH0252120B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a blower used in a vacuum cleaner or the like.

1. Construction of a conventional example and its problems FIG. 1 shows a conventional blower for a vacuum cleaner of this type, in which a centrifugal fan 1 is fixed to a shaft 2 of an electric motor at its center with a nut 3. A suction port 4 is opened in the center of the centrifugal fan 1, and blades 5 are provided on the outer periphery of the suction port 4. An air guide 6 is installed on the outer periphery of the centrifugal fan 1, and the air guide 6 is provided with a plurality of guide vanes 7.

When a vacuum cleaner is operated, the shaft 2 of the electric motor rotates (counterclockwise in FIG. 1), and the fan 1 rotates at the same time. Due to this rotation, air flows in from the suction port 4, is pushed by the blades 5, and is discharged to the outer periphery of the fan 1. The exhausted air is transferred to air guide 6.
The current is rectified by a guide vane 7, and guided into the inside of an electric motor (not shown) through a communication port 8 provided at the end thereof. The guide vanes 7 of the air guide 6 are provided along the streamline direction of the air discharged from the fan 1 in order to efficiently straighten the air. In addition, air is forcefully discharged from the fan 1 and hits the inner end of the guide vane 7, generating noise.
There is a gap A between the inner end of the guide vane 7 and the outer periphery of the fan 1.
It was placed with a

The position of this guide vane 7 is determined so that when the air load is approximately constant and the air volume is approximately constant, the gap A is not made too small and the noise becomes too large, and so that the gap A is not made too large and the air discharged from the fan 1 is The filter is set at the optimal position so that the rectification effect does not deteriorate, but in the case of a load that sucks in dust, such as a vacuum cleaner, the air volume changes greatly depending on the amount of dust accumulated in the filter or the condition of the surface being cleaned. Therefore, when the air volume is high, the noise increases, and when the air volume is low, the amount of air discharged one after another from fan 1 is small, so the pressure of the air toward the outer circumference of fan 1 is reduced, and the air flows around the gap A. There was a drawback that it was difficult to enter the passage 9 even though it could only go around, and the efficiency of air blowing was greatly reduced.

Purpose of the Invention The present invention eliminates these conventional drawbacks, and maintains air blowing efficiency even when the amount of air used changes.
This is an attempt to suppress the generation of noise.

Structure of the Invention In the present invention, a movable vane that slides toward and away from the centrifugal fan is provided at the end of the guide vane on the centrifugal fan side, and the movable vane is biased in the projecting direction.

Therefore, the movable blade moves back and forth depending on the force relationship between the air pressure, that is, the amount of air, and the biasing force produced by the fan, thereby varying the gap with the fan.

For example, a centrifugal fan used in a vacuum cleaner usually has a rotation speed of about 30,000 rpm and an outer diameter of about 109 mm. The outer circumference of the fan at this time is 30000/60×φ109
mm×π=171m/sec. In other words, air from the outer circumference of the fan hits the movable blades at a speed of 171 m/sec. This speed is a large typhoon (approximately 50 to 60 m/
sec), which is equivalent to 626 km/h, which is enough wind pressure to move the movable blades.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings.

In FIGS. 2 and 3, reference numeral 11 denotes a centrifugal fan, which has a suction port 12 at the front of its central portion, and blades 13 at its outer periphery sandwiched between side plates 14 and 15. An air guide 16 is provided on the outer periphery and bottom of the centrifugal fan 11, and a fan casing 17 is provided in front of the centrifugal fan 11 and on the outer periphery of the air guide 16. The fan casing 17 has a suction port 12 for the centrifugal fan 11 in its center.
A suction port 18 corresponding to the opening is opened, and a skirt 19 on the outer periphery forms an air passage together with the air guide 16.

The air guide 16 is provided with a plurality of guide vanes 20, the tip portion 21 of which is comprised of a slidable movable vane 26. A fixed pin 22 is provided in the movable blade 26 as shown in FIG. 3, and a spring 23 is provided between the fixed pin 22 and the movable blade 26.
is stretched, and the elasticity of the spring 23 pushes the movable blade 26 toward the fan 11. Reference numeral 24 denotes an air passage divided by the guide vanes 20, which terminates at a communicating passage 25 opened below the air guide 16 at its outer circumferential end.
continues inside the electric motor (not shown).

In the above configuration, when the vacuum cleaner is operated,
The electric motor rotates the centrifugal fan 11 (counterclockwise in the case of Fig. 3), and air flows from the suction port 18 to the suction port 1.
2 → Inside of fan 11 → Air passage 24 → Communication passage 25
The flow is rectified by the guide vane 20 and the movable vane 26 in the air passage 24. Since the movable blade 26 is pressed toward the fan 11 by the spring 23, when the floor nozzle is attached to the floor and cleaning is performed, or when there is a lot of dust in the filter, the suction air volume is small and the dust is discharged from the fan 11. The air hitting the movable blade 26 is weak, the movable blade 26 becomes closer to the fan 11, and the gap A becomes smaller. Therefore, the air coming out of the fan 11 can be immediately guided to the air passage 24 by the movable blades 26, and unlike in the past, the gap A is too large and circulation flow does not occur, and the air blowing efficiency is high. Become something.

On the other hand, when the floor nozzle is raised above the floor surface, there is little dust on the filter, and the suction air volume is large, the air discharged from the fan 11 hits the movable blade 26 strongly, and the movable blade 26 is pushed against the spring 23. will be pushed backwards. Therefore, the movable blade 26 slides rearward on the outside of the guide blade 20, and the gap A becomes larger. Therefore, the air coming out of the fan 11 does not immediately hit the movable blades 26, and the generation of noise can be suppressed.

If it is a normal household vacuum cleaner, the filter is new and the air volume is low when the floor nozzle is in the air.
The air flow rate is 1.7 to 2.0 m ³ /min, and the gap A should be around 3 mm to 6 mm, considering air blowing efficiency and noise. If the filter is full of dust and the floor nozzle is attached to the surface to be cleaned, the air volume should be 1.0 to 6 mm. 1.5m ³ /min, gap A
A good value is about 1 mm to 3 mm.

Effects of the Invention As described above, according to the present invention, the tips of the guide vanes of the air guide are elastically supported and the gap between them and the fan is automatically varied according to the air volume, thereby improving air blowing efficiency and suppressing noise. It is something that can be achieved.

[Brief explanation of drawings]

Figure 1 is a plan view of a conventional vacuum cleaner blower.
FIG. 2 is an exploded perspective view of a blower for a vacuum cleaner according to an embodiment of the present invention, and FIG. 3 is an enlarged explanatory view of an air guide portion of the blower. 11...Centrifugal fan, 16...Air guide, 2
0... Guide vane, 23... Spring, 26... Movable vane.

Claims (1)

[Claims] 1. Equipped with a centrifugal fan having an intake port in the center and blades around the intake port, and an air guide that partitions and forms a plurality of air passages by a plurality of guide vanes arranged around the outer periphery of the centrifugal fan, The blower is provided with movable blades that slide toward and away from the centrifugal fan and are biased to protrude toward the centrifugal fan, at ends of the guide blades on the centrifugal fan side.