AU2003220845B2

AU2003220845B2 - Centrifugal fan rotor and manufacturing method thereof.

Info

Publication number: AU2003220845B2
Application number: AU2003220845A
Authority: AU
Inventors: Tsunehisa Sanagi
Original assignee: Daikin Industries Ltd
Current assignee: Daikin Industries Ltd
Priority date: 2002-04-03
Filing date: 2003-04-02
Publication date: 2007-08-09
Anticipated expiration: 2023-04-02
Also published as: AU2003220845A1; JP3589243B2; JPWO2003087582A1; CN100582491C; EP1496265A1; WO2003087582A1; CN1646814A; EP1496265A4

Description

CENTRIFUGAL FAN ROTOR

AND

MANUFACTURING METHOD THEREOF TECHNICAL FIELD The present invention relates to a centrifugal fan rotor and to a manufacturing method thereof.

BACKGROUND ART Referring to Figure 1, there is illustrated a turbo fan rotor as an example of centrifugal fan rotors. The turbo fan rotor has a main plate 1, a shroud 2, and a plurality of blades 3, 3, which are disposed between an outer peripheral part la of the main plate 1 and the shroud 2. Each blade 3 is shaped like a swept-back wing inclined in a direction opposite to the rotational direction. Reference numeral 4 indicates a boss to which a motor rotational shaft is rotatably fastened.

It is difficult to form such a turbo fan rotor as an integral molding of synthetic resin because it has a three-dimensional shape which complicates the drawing-out of a molding.

With a view to coping with this difficulty, the following conventional techniques have been proposed. For example, there is a technique known in the art in which a main plate 1 is formed integrally with blades 3, 3, and leading ends of the blades 3, 3, are welded to an interior surface of a shroud 2 made of synthetic resin. In addition, there is another conventional technique in which a main plate 1 is formed integrally with first half portions of blades 3, 3, while on the other hand a shroud 2 is formed integrally with second half portions of the blades 3, 3, Thereafter, the first half portions and the second half portions are welded together.

Problem To Be Solved SThe above-described conventional techniques, however, require a welding C- process step of a higher level of accuracy, therefore producing a problem of increased g manufacturing costs.

;Z

In addition, there is another problem that polypropylene which does not suit for welding but has advantages of being inexpensive and recycle-friendly, cannot be used as a material.

Furthermore, there is the possibility that during the operation centrifugal forces 00 cause a welded junction to come loose if deterioration with age.

C' OBJECT OF THE INVENTION It is the object of the present invention to overcome or substantially ameliorate at least one of the above disadvantages, or at least to provide a useful alternative.

SUMMARY OF THE INVENTION In a first aspect, the present invention provides a centrifugal fan rotor comprising a main plate, a shroud, and a plurality of blades disposed between an outer peripheral part is of said main plate and said shroud, wherein a rotor half-finished product formed as an integral molding of synthetic resin comprising said main plate and said blades, and said shroud formed as an integral molding of synthetic resin are manufactured separately, wherein an engaging claw is formed integrally with said shroud, and wherein an engaging part for engaging with said engaging claw is formed in each said blade, and wherein said rotor half-finished product and said shroud are united together by establishing engagement between said engaging claw and said engaging part, and wherein said engaging claw and said engaging part are constructed so that the direction of engagement of said engaging claw and said engaging part becomes a direction in which the force of engagement of said engaging claw and said engaging part increases when a centrifugal force is exerted on each said blade, wherein said engaging claw is an inward claw piece provided projectingly and for-ned integrally with an interior surface of said shroud, and wherein said engaging part is an engaging concave part formed in an external surface of each said blade.

In a second aspect, the present invention provides a centrifugal fan rotor comprising a main plate, a shroud, and a plurality of blades disposed between an outer peripheral part of said main plate and said shroud, 849596 vIlRW wherein a rotor half-finished product formed as an integral molding of synthetic N, resin comprising said main plate and said blades, and said shroud formed as an integral molding of synthetic resin are manufactured separately, wherein an engaging claw is fon-ned integrally with each said blade, and wherein an engaging part for engaging with said engaging claw is formed in said shroud, and wherein said rotor half-finished product and said shroud are united together by establishing engagement between said engaging claw and said engaging part, and wherein 00 a rib is formed integrally with a rear surface of said outer peripheral part of said main (,i CK plate, the rib warping said outer peripheral part in the direction of the rear surface, wherein the direction of engagement of said engaging claw and said engaging N part becomes a direction in which the force of engagement of said engaging claw and said engaging part increases when a centrifugal force is exerted on each said blade, wherein said engaging claw is an outward claw piece provided projectingly and formed integrally with a leading end of said each blade, Is wherein said engaging part is an engaging hole formed in said shroud.

In a third aspect, the present invention provides a method of manufacturing a centrifugal fan rotor comprising a main plate, a shroud, and a plurality of blades disposed between an outer peripheral part of said main plate and said shroud, said method comprising the steps of: providing a rotor half-finished product formed as an integral molding of synthetic resin comprising said main plate and said blades, and providing said shroud formed as an integral molding of synthetic resin separately from said rotor half-finished product, establishing engagement between an engaging claw which is formed integrally with said shroud and an engaging part which is formed in each said blade so that said rotor half-finished product and said shroud are united together, wherein said engaging claw and said engaging part are constructed so that the direction of engagement of said engaging claw and said engaging part becomes a direction in which the force of engagement of said engaging claw and said engaging part increases when a centrifugal force is exerted on each said blade, wherein said engaging claw is an inward claw piece provided projectingly and fonrmed integrally with an interior surface of said shroud, and wherein said engaging part is an engaging concave part formed in an external surface of each said blade.

In a fourth aspect, the present invention provides a method of manufacturin g a centrifugal fan rotor comprising a main plate, a shroud, and a plurality of blades disposed 84Q596 v ,11W between an outer peripheral part of said main plate and said shroud, said method N comprising the steps of: ;providing a rotor half-finished product formed as an integral molding of synthetic resin comprising said main plate, and providing said shroud formed as an integral molding of synthetic resin separately from said rotor half-finished product, establishing engagement between an engaging claw which is formed integrally Vt) with each said blade and an engaging part which is formed in said shroud so that said 00 rotor half-finished product and said shroud are united together, and forming a rib C integrally with a rear surface of said outer peripheral part of said main plate at the time of ¢€3 molding of said rotor half-finished product, wherein the rib warps said outer peripheral C part in the direction of the rear surface, wherein said engaging claw and said engaging part are constructed so that the direction of engagement of said engaging claw and said engaging part becomes a direction in which the force of engagement of said engaging claw and said engaging part increases when a centrifugal force is exerted on each said blade, wherein said engaging claw is an outward claw piece provided projectingly and formed integrally with a leading end of said each blade, and wherein said engaging part is an engaging hole formed in said shroud.

An objective is to make it possible to manufacture a fan rotor which is inexpensive and rich in recycling efficiency. A rotor fan of the preferred embodiment is assembled not by a welding means but by an engaging means.

A preferred embodiment is directed to a centrifugal fan rotor comprising a main plate 1, a shroud 2, and a plurality of blades 3, 3, disposed between an outer peripheral part I a of the main plate I and the shroud 2. And, a rotor half-finished product A which is formed as an integral molding of synthetic resin comprising the main plate 1 and the blades 3, 3, and the shroud 2 which is formed as an integral molding of synthetic resin are manufactured separately. Furthermore, an engaging claw is formed integrally with the shroud 2 or with each blade 3, while on the other hand an engaging part for engaging with the engaging claw is formed in each blade 3 or in the shroud 2. In addition, the rotor half-finished product A and the shroud 2 are united together by establishing engagement between the engaging claw and the engaging part.

The engaging claw and the engaging part are preferably constructed so that the direction of engagement of the engaging claw and the engaging part becomes a direction in which the force of engagement of the engaging claw and the engaging part increases 3s when a centrifugal force is exerted on each blade 3.

849596 v.I'RW b The engaging claw is preferably an inward claw piece 5 which is provided projectingly and formed integrally with an interior surface of the shroud 2, and the ;engaging part is an engaging concave part 6 which is formed in an external surface of each blade 3.

The engaging claw is preferably an outward claw piece 9 which is provided projectingly and formed integrally with a leading end of each blade 3, and is further characterized in that the engaging part is an engaging hole 10 which is formed in the 00 shroud 2.

C A rib 8 is preferably formed integrally with a rear surface of the outer peripheral 1o part I a of the main plate 1.

(N A method of manufacturing a centrifugal fan rotor preferably comprises a main plate 1, a shroud 2, and a plurality of blades 3, 3, disposed between an outer peripheral part la of the main plate I and the shroud 2. And, a rotor half-finished product A comprising the main plate 1 and the blades 3, 3, is formed as an integral molding of is synthetic resin separately from the rotor half-finished product A.

Thereafter, an engaging claw which is formed integrally with the shroud 2 or with each blade 3 and an engaging part which is formed in each blade 3 or in the shroud 2 are brought into engagement with each other so that the rotor half-finished product A and the shroud 2 are united together.

The direction of engagement of the engaging claw and the engaging part preferably becomes a direction in which the force of engagement of the engaging claw and the engaging part increases when a centrifugal force is exerted on each blade 3.

The engaging claw is preferably an inward claw piece 5 provided projectingly and formed integrally with an interior surface of the shroud 2, and is further characterized in that the engaging part is an engaging concave part 6 formed in an external surface of each blade 3.

The engaging claw is preferably an outward claw piece 9 provided projectingly and formed integrally with a leading end of the each blade 3, and the engaging part is an engaging hole 10 formed in the shroud 2.

A rib 8 is preferably formed integrally with a rear surface of the outer peripheral part Ia of the main plate 1 at the time of moulding of the rotor half-finished product A.

After integral moulding of the rotor half-finished product A made up of the main plate 1 and the blades 3, 3, by the use of a synthetic resin, the engaging claw fornmed integrally with the shroud 2 or with each blade 3 and the engaging portion formed in each blade 3 or in said shroud 2 are brought into engagement with each other to assemble a fan L849596 \0 1R\V O rotor. Accordingly, it is no longer necessary to employ a conventionally-required C welding means. It therefore becomes possible to employ polypropylene which is inexpensive as a material, thereby achieving the reduction in manufacturing costs and the improvement in recycling efficiency.

c s Even when a centrifugal force acts on the blade 3 during the operation, the engagement between the engaging claw and the engaging part will not come loose. As a ,result of this, durability is improved significantly and no chatter sound is produced in the 00 engaging part during the operation.

(,i Ni It is possible to firmly unite together each blade 3 and the shroud 2 by a simple 0io means such as the engaging of the claw piece 5 and the engaging concave part 6.

ri It is possible to firmly unite together each blade 3 and the shroud 2 by a simple means such as the engaging of the claw piece 9 and the engaging hole The main plate outer peripheral part la in the rotor half-finished product A takes the same shape as that of the forming die a horizontal shape) at the time immediately Is after the internal moulding. After being cooled, the main plate outer peripheral part la is bent slightly toward the side on which the rib 8 is formed toward the rear surface).

In other words, the main plate outer peripheral part la is deformed in the same direction that the blade 3 is deformed by centrifugal force. Accordingly, if assembled to the shroud 2 immediately after the integral moulding of the rotor half-finished product A, this facilitates assembly work. Furthermore, the force of engagement increases after the assembly work. As a result, assembly workability is improved and, in addition, the engagement will not come loose during the operation.

Effects of the Invention In manufacturing a centrifugal fan rotor comprising a main plate I, a shroud 2, and a plurality of blades 3, 3, disposed between an outer peripheral part la of the main plate 1 and the shroud 2, a rotor half-finished product A composed of the main plate 1 and the blades 3, 3, is formed as an integral moulding of synthetic resin and the shroud 2 is formed as anl integral moulding of synthetic resin separately from the rotor half-finished product A. And, an engaging claw integrally formed with the shroud 2 or with each blade 3 and an engaging part integrally with each blade 3 or with the shroud 2 are engaged with each other so that the rotor half-finished product A and the shroud 2 are united together.

Accordingly, in accordance with these inventions, it is no longer necessary to employ a conventionally-required welding means. It therefore becomes possible to employ 949590 i PR\W O polypropylene which is inexpensive as a material, thereby achieving the reduction in manufacturing costs and in the improvement in recycling efficiency.

In one embodiment, the direction of engagement of the engaging claw and the engaging part becomes a direction in which the force of engagement of the engaging claw C s and the engaging part increases when a centrifugal force is exerted on the blades 3, Accordingly, in accordance with these invention, even when a centrifugal force acts on the blade 3 during the operation, the engagement between the engaging claw and the 00 engaging part will not come loose. As the result of this, durability is improved significantly and no chatter sound is produced in the engaging part during the operation.

0 In one embodiment, the engaging claw is an inward claw piece 5 provided in a I projecting manner and formed integrally with an interior surface of the shroud 2, and that the engaging part is an engaging concave part 6 formed in an external surface of each blade 3. Accordingly, in accordance with these inventions, it is possible to firmly unite together each blade 3 and the shroud 2 by a simple means such as the engaging of the claw piece 5 and the engaging concave part 6.

In one embodiment, the engaging claw is an outward claw piece 9 provided in projecting manner and formed integrally with a leading end of the each blade 3, and that the engaging part is an engaging hole 10 formed in the shroud 2. Accordingly, in accordance with these inventions, it is possible to firmly unite together each blade 3 and the shroud 2 by a simple means such as the engaging of the claw piece 9 and the engaging hole In one embodiment a rib 8 is formed integrally with a rear surface of the outer peripheral part la of the main plate 1 at the time of molding of the rotor half-finished product A. Accordingly, the main plate outer peripheral part Ia in the rotor half-finished product A takes the same shape as that of the forming die a horizontal shape) at the time immediately after the integral moulding; however, after being cooled, the main plate outer peripheral part la is bent slightly toward the side on which the rib 8 is formed toward the rear surface). In other words, the main plate outer peripheral part l a is deformed in the same direction that the blade 3 is deformed by centrifugal force.

Accordingly, if assembled to the shroud 2 immediately after the integral moulding of the rotor half-finished product A, this facilitates assembly work. As the result of this, the force of engagement increases after the assembly work. Consequently, assembly workability is improved and, in addition, the engagement will not come loose during the operation.

849596 IRW BRIEF DESCRIPTION OF DRAWINGS SFigure 1 is a perspective illustration depicting a turbo fan rotor which is an Sexample of commonly-used centrifugal fan rotors; SFigure 2 is a half cross-sectional view of a centrifugal fan rotor according to a first embodiment of the present invention; Figure 3 is a half cross-sectional view showing two states of a rotor half-finished 00 product for the centrifugal fan rotor according to the first embodiment of the present Ci invention, a state immediately after being molded and a state after being cooled; CFigure 4 is an enlarged top plan view of relevant parts of a main plate of the centrifugal fan rotor according to the first embodiment of the present invention; and Figure 5 is a half cross-sectional view of a centrifugal fan rotor according to a second embodiment of the present invention.

849596 v I'RW BEST MODE FOR CARRYING OUT INVENTION Hereinbelow, several preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

A centrifugal fan rotor a turbo fan rotor) which is manufactured in accordance with each of the embodiments is similar in structure to the one previously described in terms of the Background Art (see Figure This turbo fan rotor comprises a main plate 1, a shroud 2, and a plurality of blades 3, 3, installed between an outer peripheral part la of the main plate 1 and the shroud 2. Each blade 3 is shaped like a swept-back wing which is inclined in a direction opposite to the rotational direction. Reference numeral 4 indicates a boss to which a motor rotational shaft is rotatably fastened.

Embodiment 1 Referring to Figures 2 and 4, there is shown a centrifugal fan rotor according to a first embodiment of the present invention.

In the centrifugal fan rotor the turbo fan rotor), as shown in Figure 2, an inward claw piece 5 serving as an engaging claw is formed, in a projecting manner, integrally with an internal surface of the shroud 2. On the other hand, an engaging concave part 6 serving as an engaging part is formed on the side of an external surface of each blade 3. And, by bringing the claw piece 5 into engagement with the engaging concave parts 6, each blade 3 and the shroud 2 are united together. Reference numeral 7 indicates a cavity for use in integral molding of the claw piece 5 at the time of moulding of the shroud 2.

The turbo fan rotor of the present embodiment is manufactured as follows. In the first place, a rotor half-finished product A comprising a main plate 1 and blades 3, 3, is formed as an integral molding of synthetic resin (for example, polypropylene). On the other hand, together with a claw piece 5, a shroud 2 is formed as an integral molding of synthetic resin (for example, polypropylene). Thereafter, the claw piece 5 of the shroud 2 is engaged into an engaging concave part 6 of the blade 3 so that the rotor half-finished product A and the shroud 2 are united together integrally.

As a result of such arrangement, the blade 3 and the shroud 2 are firmly united together by a simple means such as engagement of the claw piece 5 and the engaging concave part 6. Accordingly, unlike the conventional techniques, it is no longer necessary to use a welding means.

Consequently, it becomes possible to use inexpensive polypropylene as a material and the reduction in manufacturing costs and the improvement in recycling efficiency are achieved.

Besides, the shroud 2 and the blade 3 are united together by engagement between the inward claw piece 5 and the engaging concave part 6 formed in the outer peripheral surface of the blade 3. As the result of this, the direction of engagement of the claw piece and the engagement concave part 6 becomes a direction in which the force of engagement increases when a centrifugal force acts on the blade 3.

Accordingly, even when a centrifugal force is exerted on the blade 3 during operation, the engagement between the claw piece 5 and the engaging concave part 6 will not come loose. As the result of this, durability is improved significantly and no chatter sound is produced in the engaging part during operation.

Ribs 8, 8, are formed integrally with a rear surface of the outer peripheral part la of the main plate 1 at the time of moulding of the rotor half-finished product A in the present embodiment. Because of the provision of the ribs 8, 8, the main plate outer peripheral part la becomes warped in the direction of the rear surface at the time of cooling after the molding. In other words, during the cooling, the surface of each rib 8 is first solidified when cooled and then is shrunk. As a result, the main plate outer peripheral part la becomes warped in the direction of the rear surface on which the ribs 8, 8, are formed. As shown in Figure 4, the ribs 8, 8, are shaped like a mound and are arranged radially, circumferentially, and in a direction of interconnecting them.

As a result of such arrangement, the main plate outer peripheral part la in the rotor half-finished product A takes the same shape as that of its forming die a horizontal shape) immediately after the integral moulding, as indicated by chain double-dashed line of Figure 3; however, after being cooled the main plate outer peripheral part la becomes warped slightly in the direction of the side on which the ribs 8, 8, are formed in the direction of the rear surface) as indicated by solid line of Figure 3. In other words, the main plate outer peripheral part la deforms in the same direction that the blades 3, 3, deform by centrifugal force. Accordingly, if assembled to the shroud 2 immediately after integral moulding of the rotor half-finished product A, this facilitates assembly work and the force of engagement increases after the assembly work. As a result, assembly workability is improved and, in addition, the engagement will not come loose.

Embodiment 2 Referring to Figure 5, there is shown a centrifugal fan rotor according to a second embodiment of the present invention.

In the centrifugal fan rotor the turbo fan rotor) of the present embodiment, an outward claw piece 9 serving as an engaging claw is provided projectingly and formed integrally with an leading end of the blade 3. On the other hand, the shroud 2 is provided with an engaging hole 10 serving as an engaging part. And, by engaging the claw piece 9 into the engaging hole 10, the blade 3 and the shroud 2 are united together.

This turbo fan rotor is manufactured as follows. In the first place, a rotor halffinished product A comprising a main plate 1 and a plurality of blades 3, 3, is formed as an integral molding of synthetic resin (for example, polypropylene), together with a claw piece 9. On the other hand, a shroud 2 is formed as an integral molding of synthetic resin (for example, polypropylene). Thereafter, the claw piece 9 of the blade 3 is engaged into the engaging hole 10 of the shroud 2, whereby the rotor half-finished product A and the shroud 2 are united together integrally.

As a result of such arrangement, the blade 3 and the shroud 2 are firmly joined together by a simple means such as engagement of the claw piece 9 into the engaging hole Accordingly, unlike the conventional techniques, it is no longer necessary to use a welding means.

Besides, the rotor half-finished product A and the shroud 2 are united together by engagement of the outward claw piece 9 into the engaging hole 10 formed in the shroud 2.

As the result of this, the direction of engagement of the claw piece 9 and the engaging hole becomes a direction in which the force of engagement increases when a centrifugal force acts on the blade 3.

Accordingly, even when centrifugal forces act on the blade 3 during operation, the engagement between the claw piece 9 and the engaging hole 10 will not come loose. As the result of this, durability is improved significantly and no chatter sound is produced in the engaging part during operation.

In addition, also in the case of the present embodiment, ribs 8, 8, are formed integrally with the rear surface of the outer peripheral part la of the main plate 1 at the time of molding of the rotor half-finished product A, as in the first embodiment.

Accordingly, the same working effects as the first embodiment are obtained.

It is needless to say that the present invention is applicable to centrifugal fan rotors other than the turbo fan rotor.

12 INDUSTRIAL APPLICABILITY As has been described above, the present invention provides a centrifugal fan rotor and a method of manufacturing a centrifugal fan rotor useful for manufacture of turbo fan rotors and especially suitable for molding of turbo fan rotors from synthetic resin.

Claims

1. A centrifugal fan rotor comprising a main plate, a shroud, and a gI plurality of blades disposed between an outer peripheral part of said main plate and said ;Z shroud, wherein a rotor half-finished product formed as an integral molding of synthetic resin comprising said main plate and said blades, and said shroud formed as an integral it' molding of synthetic resin are manufactured separately, 00 wherein an engaging claw is formed integrally with said shroud, and wherein an C engaging part for engaging with said engaging claw is formed in each said blade, and 10 wherein said rotor half-finished product and said shroud are united together by establishing engagement between said engaging claw and said engaging part, and wherein said engaging claw and said engaging part are constructed so that the direction of engagement of said engaging claw and said engaging part becomes a direction in which the force of engagement of said engaging claw and said engaging part increases when a centrifugal force is exerted on each said blade, wherein said engaging claw is an inward claw piece provided projectingly and formed integrally with an interior surface of said shroud, and wherein said engaging part is an engaging concave part formed in an external surface of each said blade.

2. A centrifugal fan rotor comprising a main plate, a shroud, and a plurality of blades disposed between an outer peripheral part of said main plate and said shroud, wherein a rotor half-finished product formed as an integral molding of synthetic resin comprising said main plate and said blades, and said shroud formed as an inteal molding of synthetic resin are manufactured separately, wherein an engaging claw is formed integrally with each said blade, and wherein an engaging part for engaging with said engaging claw is formed in said shroud, and wherein said rotor half-finished product and said shroud are united together by establishing engagement between said engaging claw and said engaging part, and wherein a rib is formed integrally with a rear surface of said outer peripheral part of said main plate, the rib warping said outer peripheral part in the direction of the rear surface, wherein the direction of engagement of said engaging claw and said engaging part becomes a direction in which the force of engagement of said engaging claw and said engaging part increases when a centrifugal force is exerted on each said blade, 849596 v I'RW wherein said engaging claw is an outward claw piece provided projectingly and formed integrally with a leading end of said each blade, N wherein said engaging part is an engaging hole formed in said shroud.

3. The centrifugal fan rotor of claim 1, wherein a rib is formed integrally with a rear surface of said outer peripheral part of said main plate. 00

4. A method of manufacturing a centrifugal fan rotor comprising a main Splate, a shroud, and a plurality of blades disposed between an outer peripheral part of said C€ main plate and said shroud, said method comprising the steps of: 0 providing a rotor half-finished product formed as an integral molding of synthetic resin comprising said main plate and said blades, and providing said shroud formed as an integral molding of synthetic resin separately from said rotor half-finished product, establishing engagement between an engaging claw which is formed integrally with said shroud and an engaging part which is formed in each said blade so that said rotor half-finished product and said shroud are united together, wherein said engaging claw and said engaging part are constructed so that thile direction of engagement of said engaging claw and said engaging part becomes a direction in which the force of engagement of said engaging claw and said engaging part increases when a centrifugal force is exerted on each said blade, wherein said engaging claw is an inward claw piece provided projectingly and formed integrally with an interior surface of said shroud, and wherein said engaging part is an engaging concave part formed in an external surface of each said blade.

A method of manufacturing a centrifugal fan rotor comprising a main plate, a shroud, and a plurality of blades disposed between an outer peripheral part of said main plate and said shroud, said method comprising the steps of: providing a rotor half-finished product formed as an integral molding of synthetic resin comprising said main plate, and providing said shroud formed as an integral molding of synthetic resin separately from said rotor half-finished product, establishing engagement between an engaging claw which is formed integrally with each said blade and an engaging part which is formed in said shroud so that said rotor half-finished product and said shroud are united together, and forming a rib integrally with a rear surface of said outer peripheral part of said main plate at the time of 8495906 v IRW molding of said rotor half-finished product, wherein the rib warps said outer peripheral part in the direction of the rear surface, wherein said engaging claw and said engaging part are constructed so that the direction of engagement of said engaging claw and said engaging part becomes a direction in which the force of engagement of said engaging claw and said engaging part increases when a centrifugal force is exerted on each said blade, t wherein said engaging claw is an outward claw piece provided projectingly and 0 formed integrally with a leading end of said each blade, and wherein said engaging part is San engaging hole formed in said shroud.

6. The centrifugal fan rotor manufacturing method of claim 4, wherein a Crib is formed integrally with a rear surface of said outer peripheral part of said main plate at the time of molding of said rotor half-finished product.

7. A centrifugal fan rotor substantially as hereinbefore described with reference to Figures 2 to 4 or 5 of the accompanying drawings. is

8. A method of manufacturing a centrifugal fan, said method being substantially as hereinbefore described with reference to Figures 2 to 4 or 5 of the accompanying drawings. Dated 28 June, 2007 Daikin Industries, Ltd. Patent Attorneys for the Applicant/Nominated Person SPRUSON FERGUSON 849596 v I'R\V