JP3170738B2 - Centrifugal fan - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centrifugal fan for an electric blower used for a vacuum cleaner or the like.

[0002]

2. Description of the Related Art FIG. 27 is a longitudinal sectional view showing an example of a conventional centrifugal fan disclosed in, for example, Japanese Patent Publication No. 6-63511, and FIG. 28 is an enlarged sectional view of a portion C in FIG.
Reference numerals 1 and 2 denote an upper fan plate and a lower fan plate which are spaced apart and opposed to each other.
Is curved upward from the outer periphery toward the center, and is formed in a substantially truncated cone shape. And the upper and lower fan plates 1,
Each of 2 has a plurality of fitting holes 3a and 4a. Reference numeral 5 denotes an intake opening provided in the upper fan plate 1. 6 is upper and lower fan plates 1 and 2
A plurality of blades partitioning a space between the blades, and are arranged in a plane radial pattern from the center of the upper and lower fan plates 1 and 2 to the peripheral edge. Reference numerals 7 and 7 denote a plurality of projections provided on both end surfaces of the blade 6 which are inscribed in the upper and lower fan plates 1 and 2, respectively, and are fitted into fitting holes 3a and 4a formed in the upper and lower fan plates 1 and 2, respectively. The upper and lower fan plates 1 and 2 and the blade 6 are fixed by caulking.

The protrusion 7 is provided in FIGS. 29 and 30 (FIG. 2).
As shown in the enlarged cross-sectional view of the D portion of FIG. 9), before the caulking, two high step portions 7a, 7a whose height from the contact surface is higher than the plate thickness of the upper and lower fan plates 1, 2 are provided. And a low step portion 7b sandwiched between the high step portions 7a and 7a and having a height from the contact surface substantially equal to the plate thickness of the upper and lower fan plates 1 and 2. Then, the high step portions 7a of the protrusions 7,
7a and the low step portion 7b are fitted into fitting holes 3a and 4a formed in the upper and lower fan plates 1 and 2, and the high step portions 7a and 7a are fixed by caulking.

FIG. 31 is a longitudinal sectional view showing an example of an electric blower to which the centrifugal fan 8 is attached. Reference numeral 9 denotes a drive motor of the electric blower 8, and reference numeral 10 denotes an output shaft of the drive motor 9 having the centrifugal fan 8 attached to one end. 11 is a fan cover of the centrifugal fan 8, 12 is a suction port provided in the fan cover 11, 13 is a peripheral opening of the centrifugal fan 8, and air sucked into the centrifugal fan 8 from the suction port 12 of the fan cover 11 is provided. The air is sucked from the intake opening 5 of the upper fan plate 1 and discharged from the peripheral opening 13. In addition, 14 is a guide blade,
15 is a casing of the drive motor 9, and 16 is an exhaust port.

The operation of the electric blower provided with the centrifugal fan 8 configured as described above will be described. When the drive motor 9 of the electric blower is driven, the output shaft 10 rotates, and the centrifugal fan 8 attached to the output shaft 10 rotates. In this way, the air sucked from the suction port 12 of the fan cover 11 is sucked into the suction opening hole 5 of the upper fan plate 1, discharged from the peripheral opening 13 through the space between the blades 6, and further driven by the guide blades 14. It is introduced into the casing 15 of the motor 9, cools each part in the casing 15, and
Is discharged from

[0006]

According to the conventional centrifugal fan 8 constructed as described above, when the centrifugal fan 8 is manufactured, the high step portions 7a, 7a provided on the projections 7 of the blade 6 are connected to the upper and lower fan plates. It must be caulked so as to protrude outside of 1 and 2. For this reason, the high steps 7a, 7
a is, as shown in FIG.
In some cases, when the centrifugal fan 8 rotates, it causes air resistance to generate turbulence in the fan cover 11, and the electric blower In addition to reducing the inhalation efficiency, this has caused noise. On the other hand, if the protruding amount of the high steps 7a, 7a after caulking is reduced as much as possible in order to reduce the air resistance, the caulking force is reduced and the high-speed rotation cannot be achieved. As shown, the fitting holes 3a (4) of the upper (lower) fan plate 1 (2)
There is a problem that a) is deformed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and eliminates air resistance during rotation of a centrifugal fan, does not generate turbulence in a fan cover, and improves the suction efficiency of an electric blower. And low noise can be realized,
It is an object of the present invention to obtain a centrifugal fan capable of improving a crimping force.

[0008]

[0009]

[0010]

[0011]

[0012]

According to a first aspect of the present invention, there is provided a centrifugal fan according to the first aspect of the present invention, wherein a fan plate is disposed so as to be spaced apart and opposed, and a space between the fan plates is disposed radially between the fan plates. A plurality of blades for partitioning the fan plate, the protrusion provided at a position in contact with the fan plate of the blade is fitted into a fitting hole formed in the fan plate and caulked, thereby forming the fan plate and In the centrifugal fan with the blade fixed, the opening area of the fitting hole is formed larger on the outer surface side than the inner surface side with which the blade contacts, and a hole is provided in the protrusion, and the protrusion is formed on the outer surface of the fan plate. It is fixed by caulking flat so as to be almost the same plane.

According to a second aspect of the present invention, there is provided a centrifugal fan, comprising: a plurality of fan plates which are spaced apart and opposed to each other; and a plurality of blades which are radially arranged between the fan plates and partition a space between the fan plates. A centrifugal fan in which the fan plate and the blade are fixed by fitting a protrusion provided at a position in contact with the fan plate of the blade into a fitting hole formed in the fan plate and caulking the blade. A V-shaped notch is provided substantially at the center of the protrusion, and the bottom of the notch is formed on an inclined surface substantially equal to the inclined surface of the inner surface of the fan plate.

[0014]

[0015]

[0016]

[0017]

[0018]

According to the first aspect of the present invention, when the projection provided with the hole is fitted into the fitting hole and the projection is crushed, the crushing force is dispersed in the longitudinal direction of the projection, and the projection is at its root. The portion is caulked flat without buckling, the gap is filled, and the air resistance decreases when the centrifugal fan rotates. Further, the crushed protrusion serves as a holding portion for the caulking force, and the caulking force is improved.

According to the second aspect of the present invention, the projections having the cutouts having different inclined surfaces are fitted into the fitting holes of the fan plate, which increase in inclination angle toward the center and curve. Crush and fill the notch. The crushed protrusion is caulked flat, and the air resistance decreases when the centrifugal fan rotates. Further, the crushed protrusion serves as a holding portion of the caulking force, and the caulking force is improved corresponding to each position on the blade.

[0020]

【Example】

Embodiment 1 FIG. 1 is a longitudinal sectional view of a first embodiment of the present invention, FIG. 2 is a plan view of FIG. 1, and FIG. 3 is an enlarged sectional view of a portion A in FIG. It shows the state where it is. Numerals 1 and 2 denote an upper fan plate and a lower fan plate which are spaced apart and opposed to each other. The upper fan plate 1 is curved upward from the outer periphery toward the suction port 5 and is formed in a substantially truncated cone shape. The fan plate 2 has a disk shape,
A mounting hole 20 is formed at the center thereof. Reference numerals 3 and 4 denote a plurality of fitting holes formed in the upper and lower fan plates 1 and 2, respectively, and the opening area is larger on the outer surface side than on the inner surface side where the blade is inscribed. Open in a tapered shape toward the outer surface side.

Reference numeral 6 denotes a plurality of blades which partition a space between the upper and lower fan plates 1 and 2 and are arranged in a plane radial pattern from the center of the upper and lower fan plates 1 and 2 to the peripheral edge. 21 and 21 are upper and lower fan plates 1 and 2
A plurality of protrusions provided on the surfaces 6a, 6b of the blade 6 inscribed in the upper and lower fan plates 1, 2 by fitting the protrusions 21, 21 into the fitting holes 3, 4 of the upper and lower fan plates 1, 2.
The upper and lower fan plates 1 and 2 and the blade 6 are fixed. The projections 21 after the projections 21 and 21 are fitted into the fitting holes 3 and 4 of the upper and lower fan plates 1 and 2 and caulked do not project outside the upper and lower fan plates 1 and 2, and As shown in FIG. 3, the cross-sectional shape is such that the volume increases toward the gap between the upper and lower fan plates 1 and 2, and the crimping force is maintained by taking such a shape after crimping. I do.

The operation of the embodiment constructed as described above will be described with reference to FIG. First, when the drive motor 9 of the electric blower is driven to rotate the output shaft 10, the centrifugal fan attached to the output shaft 10 rotates. At this time, as shown in FIG. 3, the centrifugal fan has no air resistance at the time of rotation because the protrusions 21 and 21 after the caulking do not protrude outside the upper and lower fan plates 1 and 2, and therefore noise is reduced. Also does not emit. Then, the air sucked from the suction port 12 of the fan cover 11 is supplied to the suction opening hole 5 of the upper fan plate 1.
And is discharged from the peripheral opening 13 through the space between the blades 6, and further introduced into the casing 15 of the drive motor 9 by the guide vanes 14 to cool the respective parts in the casing 15 and discharged from the exhaust port 16. You.

Therefore, according to the present embodiment, since the protrusions 21 and 21 after caulking do not protrude outside the upper and lower fan plates 1 and 2, there is no air resistance when the centrifugal fan rotates, and the fan cover 11 Turbulence does not occur within
The suction efficiency of the electric blower is improved, and the noise can be reduced. Furthermore, since the protrusions 21 and 21 after caulking increase in volume toward the gap between the upper and lower fan plates 1 and 2, a strong caulking force can be maintained.

Embodiment 2 In the first embodiment, the opening areas of the fitting holes 3 and 4 provided in the upper and lower fan plates 1 and 2 are made larger on the outer surface side than on the inner surface side where the blade 6 is inscribed. In this embodiment,
At this time, the opening area ratio of the fitting holes 3 and 4 is further limited to a constant value. That is, in this embodiment, the opening areas of the fitting holes 3 and 4 are set such that the opening area on the outer surface side is 1.1 to 1.5 times the opening area on the inner surface side where the blade 6 is inscribed. It was done.

According to this embodiment configured as described above,
The protrusions 21 and 21 can be flatly caulked in the fitting holes 3 and 4 without any gap, so that the air resistance can be reduced when the centrifugal fan rotates, and the crushed protrusions 21 and 21 maintain the caulking force. Since it is a part, the swaging force is improved. On the other hand, when the opening area on the outer surface side is 1.5 times or more the opening area on the inner surface side where the blade 6 is inscribed, a gap remains in the fitting hole 3 after caulking as shown in FIG. Since the amount of crushing of the protruding portion 21 also increases, problems such as buckling of the root portion 21c of the protruding portion 21 and deformation of the fitting hole 3 occur, which is not preferable. In the above description, the case of the upper fan plate 1 has been described, but the same applies to the case of the lower fan plate 2 (the same applies to the following embodiments).

Embodiment 3 FIG. 5 is a longitudinal sectional view of a third embodiment of the present invention, and FIG. 6 is an enlarged sectional view of a portion B in FIG. In the first and second embodiments, the fixed state after the crimping of the protrusion 21 is shown, but in the present embodiment, the state before the crimping is shown. In the present embodiment, when the plurality of protrusions 21 and 21 provided on the blade 6 are fitted into the fitting holes 3 and 4 of the upper and lower fan plates 1 and 2, the protrusions project from the outer surfaces of the upper and lower fan plates 1 and 2. The volume S to be formed is substantially equal to the volume V of the gap formed when the projections 21 and 21 are fitted into the fitting holes 3 and 4. According to the present embodiment configured as described above, when the protrusion 21 is caulked, the protrusion 21 does not protrude to the outer surfaces of the upper and lower fan plates 1 and 2 and reduces the air resistance when the centrifugal fan rotates. And can be crimped into the fitting holes 3 and 4 without any gap, and the crushed projection 2
Since 1 serves as a holding portion of the caulking force, the caulking force is improved.

Embodiment 4 FIG. 7 shows a fourth embodiment of the present invention, showing a state before swaging of the projection 21.
FIG. 8 is an explanatory view of FIG. 7. Reference numeral 22 denotes a step formed on the outer surface side of the fitting hole 3 substantially in parallel with the outer surface of the upper fan plate 1, and has an opening area larger than the opening area on the side where the blade 6 inscribes the upper fan plate 1. It is. As shown in FIG. 8, the depth h of the step 22 of the fitting hole 3 is set to 2/3 or less of the thickness t of the upper fan plate 1.

FIG. 9 is a diagram showing the results of the experiment. The horizontal axis represents the depth h of the step 22 and the vertical axis represents the depth h of the step 22 of the fitting hole 3 when the caulking force is taken. Indicates that the caulking force is high when the thickness is 2/3 or less of the plate thickness t of the upper fan plate 1. Therefore, according to the present embodiment, when the depth h of the step portion 22 of the fitting hole 3 is set to 2/3 or less of the thickness t of the upper fan plate 1, the projection 21 is positioned outside the upper fan plate 1. It is possible to caulk without protruding, the air resistance is reduced when the centrifugal fan rotates, and the crushed protrusion 21 serves as a holding portion for caulking force, and the caulking force is improved.

Fifth Embodiment FIG. 10 is an enlarged sectional view of a main part of a fifth embodiment of the present invention showing a state before caulking of a projection 21, and FIG. 11 is an enlarged sectional view of a main part showing a state after caulking. . Reference numeral 23 denotes a rectangular hole formed substantially at the center of the protrusion 21 of the blade 6, and the protrusion 21 is fitted into a tapered fitting hole 3 having a larger outer surface area. is there. In the projection 21 configured as described above, as shown in FIG. 10, the force F for crushing the projection 21 at the time of caulking is dispersed as f in the longitudinal direction of the projection 21. Therefore, as shown in FIG. 11, the base portion 21c of the projection 21 can be caulked flat without buckling. For this reason, the protrusion 21 does not protrude outside the upper fan plate 1 and the air resistance decreases when the centrifugal fan rotates, and the crushed protrusion 21 serves as a holding portion of the crimping force, and the crimping force is improved.

Embodiment 6 FIG. 12 is an enlarged sectional view of a main part of a sixth embodiment of the present invention, showing a state before the caulking of the projection 21. In the fifth embodiment, the case where the rectangular hole 23 is formed substantially at the center of the protrusion 21 of the blade 6 is shown. In the present embodiment, the oval hole 24 is provided. is there. Also in the present embodiment, the base 21c of the projection 21 can be caulked flat without buckling, the air resistance decreases when the centrifugal fan rotates, and the crushed projection 21 serves as a holding portion for caulking force. The caulking power is improved.

Seventh Embodiment FIG. 13 is an enlarged sectional view of a main part of a seventh embodiment of the present invention, showing a state before crimping of a projection 21. In the fifth embodiment, the rectangular hole 23 is provided substantially at the center of the protrusion 21 of the blade 6, but in this embodiment, three substantially square holes 25 are arranged and drilled. Also in the present embodiment, it is possible to caulk the base 21c of the protrusion 21 flat without buckling, to reduce the air resistance when the centrifugal fan rotates, and to make the collapsed protrusion 21 a holding part of the caulking force. The crimping force is improved. In the present embodiment, the hole 25 is formed in a substantially square shape and three holes are arranged and drilled. However, the shape of the hole may be any shape, and the number thereof is not limited.

Embodiment 8 FIG. 14 is an enlarged plan view of a main part of an eighth embodiment of the present invention. 3 is a fitting hole formed in the upper fan plate 1;
The protrusion 21 of the blade 6 is fitted. In this embodiment, the vicinity of both ends of the outer surface side opening 30a of the fitting hole 3 is
The blade is formed in a tapered shape that expands from the inner surface side inscribed inward toward the outer surface side, and its opening area is set to the opening 3 on the inner surface side.
0b is formed larger than the opening area. In the present embodiment configured as described above, when the protrusion 21 is fitted into the fitting hole 3 and caulked, the protrusion 21 has a large volume at both ends and can be firmly fixed. Therefore, according to the present embodiment, the air resistance can be reduced when the centrifugal fan rotates, and the swaging force can be improved.

Embodiment 9 FIG. 15 is an enlarged plan view of a main part of a ninth embodiment of the present invention.
6 is a longitudinal sectional view. Reference numeral 3 denotes a fitting hole formed in the upper fan plate 1, into which the protrusion 21 of the blade 6 is fitted. In the present embodiment, both ends of the outer surface side opening 30a of the fitting hole 3 and the inner peripheral surface 26 side of the blade 6 are formed in a tapered shape which expands from the inner surface side where the blade 6 is inscribed toward the outer surface side. , The opening area of the inner side opening 30b.
Is formed so as to be larger than the opening area. According to this embodiment, when the protrusion 21 is caulked, the volume of the protrusion 21 at both ends and the inner peripheral surface 26 side of the blade 6 is increased, and the protrusion 21 can be firmly fixed. The air resistance is reduced, and the crimping force can be further improved. In this case, as shown in FIG. 16, the protruding portion 21 of the blade 6 may be formed in a tapered shape so that the outer peripheral surface 27 side of the blade 6 decreases in volume upward.

Embodiment 10 FIG. 17 is an enlarged plan view of a main part of a seventh embodiment of the present invention.
8 is a longitudinal sectional view. Reference numeral 3 denotes a fitting hole formed in the upper fan plate 1, into which the protrusion 21 of the blade 6 is fitted. In this embodiment, both ends of the outer surface side opening 30a of the fitting hole 3 and the outer peripheral surface 27 side of the blade 6 are formed in a tapered shape expanding from the inner surface side where the blade 6 is inscribed toward the outer surface side, The opening area is set to the inner side opening 30b.
Is formed so as to be larger than the opening area. Also in the present embodiment, effects similar to those of the ninth embodiment can be obtained. In this case, as shown in FIG. 18, the protrusion 21 of the blade 6 may be formed in a tapered shape so that the volume decreases toward the upper side of the inner peripheral surface 26 of the blade 6.

Embodiment 11 FIG. 19 is an enlarged plan view of a main part of an eleventh embodiment of the present invention. 3 is a fitting hole formed in the upper fan plate 1;
Here, the protrusion of the blade is fitted. In this embodiment, the opening area of the outer opening 30a of the fitting hole 3 is formed larger than the opening area of the inner opening 30b.
The fitting hole 3 is formed such that the shape of the outer surface side opening 30a and the shape of the inner surface side opening 30b are different. For example, the shape of the inner side opening 30b is rectangular,
The shape of the outer opening 30a is an ellipse. According to this embodiment, the shape of the outer opening 30a and the inner opening 30
Since the shape of b is deformed, when the protrusion 21 is caulked, the protrusion 21 is filled in the outer surface side opening 30a and does not protrude to the outside, and the air resistance decreases when the centrifugal fan rotates, The caulking power is improved.

Embodiment 12 FIG. 20 is an enlarged plan view of a main part of a twelfth embodiment of the present invention. 3 is a fitting hole formed in the upper fan plate 1;
Here, the protrusion 21 is fitted. The outer opening 30a of the fitting hole 3 is enlarged on both sides of the inner peripheral surface 26 and the outer peripheral surface 27 of the blade 6, and the opening area thereof is larger than the opening area of the inner opening 30b. Is formed. Therefore, according to the present embodiment, as in the case of the eleventh embodiment, the air resistance decreases when the centrifugal fan rotates,
Further, the crimping force can be improved. In the above embodiment, both ends of the protruding portion 21 of the blade 6 may be tapered so that the volume decreases from the root portion 21c toward the upper portion 21d as shown in the sectional view of FIG.

Embodiment 13 FIG. 22 is an enlarged sectional view of a main part of a thirteenth embodiment of the present invention showing a state before caulking, and FIG. 23 is a sectional view of FIG. In the figure, reference numeral 3 denotes a fitting hole formed in the upper fan plate 1, into which the protrusion 21 of the blade 6 is fitted. 2
1e, 21e are both side protrusions located on both sides of the upper part of the protrusion 21 of the blade 6, and the outer surface 3 of the upper fan plate 1 when the protrusion 21 is fitted into the upper fan plate 1.
It is formed so as to protrude outward from the outside. 21f
Is a substantially central portion of the protrusion 21, that is, both side protrusions 21e,
A valley having a V-shaped cross section formed between 21e and 21g is a valley bottom of the valley 21f. As shown in FIG. 23, the valley bottom 21g is formed to be inclined so as to have substantially the same inclination angle as the inclined surface of the inner surface 32 of the upper fan plate 1.

That is, as shown in FIG. 2, the upper fan plate 1 is provided on a spirally mounted blade 6, and is substantially horizontal on the outer peripheral side, but in the circumferential direction toward the center. It bends with an increased angle of inclination.
For this reason, as shown in FIG.
The shape of the valley bottom 21g of f is formed to be inclined along the shape of the inner surface 32 in which the blade 6 is inscribed in the upper fan plate 1. In other words, when the blade 6 is fixed to the curved upper fan plate 1 by caulking, the outer peripheral side 33 of the blade curvature comes into contact with the inner surface 32 of the upper fan plate 1 as shown in FIG. Therefore, as shown in FIG. 25, if the shape of the valley bottom 21g is formed perpendicular to the direction in which the blade 6 stands, the inner peripheral side 3
A gap P may be formed at the bottom 21g of the valley 21f. For this reason, as shown in FIG.
1 g was inclined so as to increase from the outer peripheral side 33 to the inner peripheral side 34 of the blade curvature, that is, in accordance with the inclined surface of the inner surface 32 of the upper fan plate 1.

Accordingly, as shown in FIG. 26, from the outer peripheral side of the centrifugal fan to the inner peripheral side of the center, a V-shaped valley 21 is formed.
The inclination angle of the valley bottom 21g of f is gradually increased. In the present embodiment, while being configured as described above, the outer peripheral surface 3 of the upper fan plate 1
The volume of the protruding portion of the protruding portion 21 protruding from 1 is substantially equal to the volume of the gap when the protruding portion 21 is fitted into the fitting hole 3. Therefore, according to the present embodiment, the air resistance is reduced when the centrifugal fan rotates, and the caulking force can be improved corresponding to each position on the blade 6.

[0040]

[0041]

[0042]

[0043]

[0044]

As is clear from the above description, the centrifugal fan according to the present invention has the following effects. A fan plate that is spaced apart and opposed,
A plurality of blades radially arranged between the fan plates to partition a space between the fan plates, and a protrusion provided at a position of the blades in contact with the fan plate is fitted to the fan plate. In the centrifugal fan in which the fan plate and the blade are fixed by fitting into the fitting hole and caulking, the opening area of the fitting hole is formed larger on the outer surface side than on the inner surface side where the blade contacts, and a hole is provided in the projection, Since the protruding portion is fixed by caulking flat so as to be substantially the same plane as the outer surface side of the fan plate, when caulking the protruding portion, the force for crushing the protruding portion is dispersed in the longitudinal direction of the protruding portion, and the root portion is It can be caulked flat without buckling.

The fan plate further includes a plurality of fan plates which are spaced apart from each other and which are arranged radially between the fan plates to partition a space between the fan plates. In the centrifugal fan in which the fan plate and the blade are fixed by fitting the protrusion provided at the position into the fitting hole formed in the fan plate and caulking, a V-shaped The notch is provided, and the bottom of the notch is formed on an inclined surface substantially equal to the inclined surface of the inner surface of the fan plate, so that no gap is formed at the bottom of all the notches.
The crushed protrusion serves as a holding portion of the caulking force, and the caulking force is improved corresponding to each position on the blade.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a first embodiment of the present invention.

FIG. 2 is a plan view of FIG.

FIG. 3 is an enlarged sectional view of a portion A in FIG. 1;

FIG. 4 is a sectional view of a comparative example of the second embodiment of the present invention.

FIG. 5 is a longitudinal sectional view of a third embodiment of the present invention.

FIG. 6 is an enlarged sectional view of a portion B in FIG. 5;

FIG. 7 is an enlarged sectional view of a main part of a fourth embodiment of the present invention.

FIG. 8 is an explanatory diagram of FIG. 7;

FIG. 9 is a diagram showing a relationship between a step depth and a caulking force.

FIG. 10 is an enlarged sectional view of a main part of a fifth embodiment of the present invention.

11 is an enlarged sectional view of a main part showing a state after caulking in FIG. 10;

FIG. 12 is an enlarged sectional view of a main part of a sixth embodiment of the present invention.

FIG. 13 is an enlarged sectional view of a main part of a seventh embodiment of the present invention.

FIG. 14 is an enlarged plan view of a main part of an eighth embodiment of the present invention.

FIG. 15 is an enlarged plan view of a main part of a ninth embodiment of the present invention.

FIG. 16 is a longitudinal sectional view of a ninth embodiment of the present invention.

FIG. 17 is an enlarged plan view of a main part of a tenth embodiment of the present invention.

FIG. 18 is a longitudinal sectional view of a tenth embodiment of the present invention.

FIG. 19 is an enlarged plan view of a main part of an eleventh embodiment of the present invention.

FIG. 20 is an enlarged plan view of a main part of a twelfth embodiment of the present invention.

FIG. 21 is a longitudinal sectional view of a twelfth embodiment of the present invention.

FIG. 22 is an enlarged sectional view of a main part of a thirteenth embodiment of the present invention.

FIG. 23 is a sectional view of FIG. 22;

FIG. 24 is an explanatory diagram of a thirteenth embodiment.

FIG. 25 is an explanatory diagram of a thirteenth embodiment.

FIG. 26 is an explanatory diagram of a thirteenth embodiment.

FIG. 27 is a longitudinal sectional view showing an example of a conventional centrifugal fan after caulking.

FIG. 28 is an enlarged sectional view of a portion C in FIG. 27;

FIG. 29 is a longitudinal sectional view showing an example of a conventional centrifugal fan before caulking.

30 is an enlarged sectional view of a D part in FIG. 29;

FIG. 31 is a longitudinal sectional view showing an example of a conventional electric blower.

FIG. 32 is an operation explanatory view showing an example of a conventional centrifugal fan after caulking.

[Explanation of symbols]

1 upper fan plate, 2 lower fan plate,
3, 4 fitting holes, 6 blades, 21 protrusions, 21f
Valley, 21g valley bottom, 22 steps, 23, 24,
25 holes.

Continuation of the front page (56) References JP-A-4-259695 (JP, A) JP-A-5-192426 (JP, A) JP-A-4-297680 (JP, A) JP-A-63-274355 (JP) , A) JP 514585 (JP, U) JP 5-6105 (JP, U) JP 5-8489 (JP, U) (58) Fields surveyed (Int. Cl. ⁷ , DB Name) F04D 29/28

Claims (2)

(57) [Claims] 1. A fan plate, which is spaced apart and opposed to a plurality of blades, and a plurality of blades are arranged radially between the fan plates to partition a space between the fan plates. In the centrifugal fan in which the fan plate and the blade are fixed by fitting the protrusion provided at the contact position into the fitting hole formed in the fan plate and caulking, the opening area of the fitting hole is reduced. The outer surface side is formed larger than the inner surface side with which the blade contacts, and a hole is provided in the protrusion, and the protrusion is fixed by caulking flat so as to be substantially flush with the outer surface side of the fan plate. Centrifugal fan. 2. A fan plate, which is spaced apart and opposed to each other, and a plurality of blades radially arranged between the fan plates to partition a space between the fan plates, wherein the blade has a fan plate. In the centrifugal fan in which the fan plate and the blade are fixed by fitting the protrusion provided at the contacting position into a fitting hole formed in the fan plate and caulking, A centrifugal fan comprising a V-shaped notch, and a bottom of the notch formed on an inclined surface substantially equal to an inclined surface of an inner surface of the fan plate.