JP2000161295A - Propeller fan and manufacture of propeller fan - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a propeller fan capable of preventing each vane outer circumferential part from being damaged, and provide a manufacturing method of the propeller fan. SOLUTION: In this propeller fan composed of a cylindrical shaped boss 1, and of plural vanes 2, 2,... integrally projected out of the outer circumference of the boss 1, the boss 1 and the vanes 2, 2,... are formed out of each integral molding part made out of synthetic resin possessing stiffness, and a sheathing part 8 made out of flexible synthetic resin is formed in the outer circumferential peripheral part of each vane 2, so that the outer circumferential part of each vane 2 is made to be covered with the sheathing part 8 made out of flexible synthetic resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a propeller fan and a method for producing the propeller fan.

[0002]

2. Description of the Related Art In general, a propeller fan is formed by forming a plurality of blades on an outer periphery of a boss for pivotally supporting a rotation shaft. It is said that it is advantageous to employ an aerofoil-shaped blade whose thickness gradually decreases toward.

On the other hand, as a blade material of a propeller fan,
Lightweight synthetic resin is attracting attention, and a propeller fan in which a boss and a blade are integrally formed of synthetic resin has been developed.

[0004] Further, in order to reduce the weight of the propeller fan, attempts have been made to hollow the inside of the above-mentioned aerofoil-shaped blade.

[0005]

However, since bosses and blades are required to have considerable rigidity, synthetic resin having high rigidity is used as a material.
Such a synthetic resin has high rigidity but has brittleness. When a hard object hits the outer peripheral portion of the blade which is thin during transportation, assembling or use, the portion is easily damaged. There is a problem that. In particular, as described above, in the case of an aerofoil-shaped blade, the above-described problem is likely to occur because the thickness of the trailing edge portion of the blade is thin. Even in the case of a hollow blade, similar problems occur because a synthetic resin having higher rigidity is used as a material of the blade.

The present invention has been made in view of the above points, and has as its object to provide a propeller fan capable of preventing damage to a blade outer peripheral portion and a method for manufacturing such a propeller fan.

[0007]

According to the first aspect of the present invention, as a means for solving the above-mentioned problems, a cylindrical boss 1 is provided.
And a plurality of blades 2 integrally protruding from the outer periphery of the boss 1.
2. In the propeller fan consisting of
And the blades 2, 2,... Are integrally formed of a synthetic resin having rigidity, and a covering portion 8 made of a synthetic resin having flexibility is formed on the outer peripheral edge of each of the blades 2. ing.

[0008] With the above configuration, the blade 2
The outer peripheral portion of the cover portion 8 is made of a flexible synthetic resin.
Thus, even if a hard object hits the outer periphery of the blade 2 during transportation, assembling, or use, damage to the portion can be prevented.

As in the invention of claim 2, claim 1
In the propeller fan described above, when each of the blades 2 is a hollow blade having a hollow portion 5, the weight of the blade 2 can be reduced.

According to a third aspect of the present invention, as a means for solving the above-mentioned problems, the boss comprises a cylindrical boss 1 and a plurality of blades 2, 2,... In the propeller fan, a fan half-molded body 6 comprising the boss 1 and a blade main body 3 constituting one surface of each of the blades 2 and a lid plate 4 joined to the blade main body 3 with a hollow portion 5 interposed therebetween. Are made of rigid synthetic resin, and the outer peripheral edges of the lid plate 4 and the blade body 3 are
The bonding is made via a covering portion 8 made of a synthetic resin having flexibility.

With the above-described structure, a member for joining the outer peripheral edges of the blade body 3 and the cover plate 4 constituting the hollow blade 2 and the covering portion 8 made of a synthetic resin having flexibility are provided. By using the components of the hollow blade, it is possible to prevent damage to the portion when the hard object hits the outer periphery of the blade 2 during transportation, assembly, or use.

As in the invention of claim 4, claim 1
4. The propeller fan according to claim 3, wherein a serration 11 having a sawtooth shape is formed at a position on a rear edge side of each of the blades 2 in the covering portion 8. A serration 11 having a function of rectifying the air flow at the blade trailing edge 8a is formed on the covering portion 8 to improve the aerodynamic characteristics of the blade 2 and to improve the aerodynamic characteristics of the blade 2 during transportation, assembling or use. It is possible to prevent damage to the site when a hard object is hit.

According to a fifth aspect of the present invention, as a means for solving the above-mentioned problems, the boss comprises a cylindrical boss 1 and a plurality of blades 2, 2,... In manufacturing the propeller fan, the boss 1 and the blades 2 are molded from a rigid synthetic resin, and the outer peripheral edge of each of the blades 2 is covered with a covering portion 8 made of a synthetic resin having flexibility. To join.

[0014] By the above-mentioned structure, the cover 8 made of a synthetic resin having flexibility is joined to the outer peripheral edge of each blade 2 formed of a synthetic resin having rigidity. A propeller fan can be obtained that can prevent damage to the portion even when a hard object hits the outer periphery of the blade 2 during middle, assembling, or use.

As in the invention of claim 6, claim 5
The method for manufacturing a propeller fan according to claim 1, wherein the boss 1
When forming the blades 2, 2,...
When the inside is hollow, a lightweight propeller fan can be obtained.

According to a seventh aspect of the present invention, as a means for solving the above-mentioned problems, the boss comprises a cylindrical boss 1 and a plurality of blades 2, 2,... In manufacturing a propeller fan, a fan half-molded body 6 composed of the boss 1 and a blade main body 3 constituting one surface of each of the blades 2 is joined to the blade main body 3 with a hollow portion 5 interposed therebetween. After the cover plate 4 is molded in advance with a rigid synthetic resin, the outer peripheral edges of the cover plate 4 and the blade body 3 are joined via a covering portion 8 made of a synthetic resin having flexibility. I have to.

With the above arrangement, after the fan half-molded body 6 composed of the boss 1 and the blade body 3 is integrally formed of a rigid synthetic resin, the outer peripheral edge of the cover plate 4 and the blade body 3 is formed. In the simple method of joining the parts via a covering part 8 made of a flexible synthetic resin, even if an object hits the outer periphery of the blade 2 during transportation, assembling or use, damage to the part is prevented. A lightweight propeller fan that can be prevented is obtained.

According to the present invention, as means for solving the above-mentioned problems, a cylindrical boss 1 and a plurality of hollow blades 2, 2,... In manufacturing a propeller fan, the boss 1
And a first cavity 14 for forming a fan half-molded body 6 in which the blade body 3 constituting one surface of each of the blades 2 is integrated, and a state in which a hollow portion 5 is interposed in the blade body 3. A pair of molds 12 and 13 having a second cavity 15 for molding the lid plate 4 to be joined with the first and second cavities 14 and 15 are used. After injecting a synthetic resin to form the fan half-molded body 6 and the cover plate 4, the fan half-molded body 6 is left in one mold 12 and the cover plate 4 is left in the other mold 13. The molds 12 and 13 are opened, and thereafter, the molds 12 and 13 are slid with each other to perform mold matching, and the fan half-molded body 6 and the cover plate 4 are abutted with each other. Abutment surfaces 6a, 4a of the fan semi-molded body 6 and the cover plate 4 The edge, so that by injecting synthetic resin having flexibility to form the covering portion 8 that joins the said fan half molded body 6 and the cover plate 4 with solidified state.

As described above, the fan half-molded body 6 formed of a synthetic resin having rigidity using the pair of molds 12 and 13 is butted against the cover plate 4, and the mating surfaces 6a and 4a are formed. By merely injecting a synthetic resin having flexibility in a solidified state into the periphery, the fan half-molded body 6 is formed.
Is formed, which joins the cover plate 4 and the cover plate 4, so that the manufacturing process and the manufacturing apparatus can be simplified, and the formation of the covering portion 8 which also functions as a joining member allows for assembling during transportation. A light propeller fan can be obtained that can prevent damage to the portion even when an object hits the outer periphery of the blade 2 during or during use.

As in the ninth aspect, the fifth aspect
9. The method of manufacturing a propeller fan according to claim 8, wherein each of the blades 2 is provided in the covering portion 8. 10.
When the serration 11 having a sawtooth shape is formed at a position on the trailing edge side, the serration 11 having a function of rectifying the air flow at the blade trailing edge 8a is formed on the covering portion 8 made of a synthetic resin having flexibility. Thus, it is possible to obtain a propeller fan that can prevent damage to a portion of the blade 2 when a hard object hits the outer periphery of the blade 2 during transportation, assembly, or use while improving the aerodynamic characteristics of the blade 2.

[0021]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

As shown in FIGS. 1 and 2, this propeller fan has a cylindrical boss 1 and a plurality (for example, three) of blades 2, 2, which are integrally provided on the outer periphery of the boss 1. 2
Each of the blades 2 is integrally formed with the boss 1 and forms one surface side (that is, a negative pressure surface side) of the blades 2. On the other hand, the cover plate 4 is joined with the hollow portion 5 interposed therebetween, and has an aerofoil shape in which the thickness gradually decreases from the front edge toward the rear edge in the rotation direction M. The boss 1 and the blade main body 3 form a fan semi-molded body 6 which is an integrally molded product of a rigid synthetic resin (for example, a glass fiber reinforced styrene resin). Reference numeral 7 denotes a shaft hole formed for inserting the motor rotation shaft into the boss 1.

The outer peripheral edge of the blade body 3 and the cover plate 4
They are joined via a covering portion 8 made of a synthetic resin having flexibility (for example, an elastomer or the like). The covering part 8
As shown in FIG. 3, each of the blades has a shape that constitutes the outer peripheral portion of the blade 2, and is in a state of being cut into grooves 9, 10 formed on the periphery of the blade main body 3 and the cover plate 4. Further, a serration 11 having a sawtooth shape for rectifying the air flow is formed on the trailing edge portion 8 a of the blade in the covering portion 8.

A method of manufacturing the propeller fan having the above configuration will be described with reference to FIGS.

As shown in FIG. 4, the propeller fan has a first cavity 14 for molding the fan half-molded body 6 and a second cavity 15 for molding the cover plate 4. It is manufactured using a pair of molds 12 and 13. In the case of this embodiment, the mold 12 is a movable mold that is horizontally moved in a direction away from the mold 13, and the mold 13 is a slide mold that is vertically slid with respect to the movable mold 12. It is a type.

The first cavity 14 is formed between a male die 16 formed on the movable die 12 and a female die 17 formed on the slide die 13, and the second cavity 15 is formed on the movable die 12. The male mold 18 formed on the moving mold 12
And a female mold 19 formed on the slide mold 13. Reference numeral 20 denotes a first sprue for guiding a molten synthetic resin having a rigidity in a solidified state, reference numeral 21 denotes a second sprue for guiding a molten synthetic resin having a flexibility in a solidified state, and reference numeral 22 denotes the first and second cavities 14.
15 is a first injection nozzle for injecting a molten synthetic resin having rigidity in a solidified state; and 24 is a first injection nozzle for injecting a molten synthetic resin having flexibility in a solidified state. Of the second injection nozzle.

Next, a procedure for manufacturing a propeller fan using the above-described apparatus will be described.

First, as shown in FIG. 4, the movable mold 12 and the slide mold 13 are matched, and the male and female molds 17 and 16 are formed.
With the first and second cavities 14 and 15 formed between the male and female dies 19 and 18, the first sprue 20
Then, a molten synthetic resin (for example, glass fiber reinforced styrene resin) having rigidity in a solidified state is injected from the first injection nozzle 23. Then, the molten synthetic resin is filled in the first and second cavities 14 and 15, as shown in FIG. 5, and the fan half-molded body 6 and the cover plate 4 are molded in the cavities 14 and 15, respectively.

After cooling and solidification of the fan half-molded body 6 and the cover plate 4, an arrow A shown in FIG.
As shown by, the movable mold 12 is separated from the slide mold 13 and opened. Then, the female mold 17 and the male mold 18
Are detached from the fan semi-molded body 6 and the lid plate 4, respectively.
The fan half-mold 6 and the cover plate 4 are
And female mold 19 respectively. When this mold opens, the first
The scrap resin 25 fixed on the sprue 20 and the runner 22 is separated and dropped. The end surfaces of the blade main body 3 and the cover plate 4 in the fan semi-molded body 6 thus obtained are butted surfaces 6a and 4a which are butted against each other.

Next, as shown in FIG. 7, the slide mold 13 is moved upward (ie, arrow B) by driving means (not shown).
After that, the movable mold 12 is moved in the direction of arrow C to perform mold matching, and the butted surface 6a of the fan half-molded body 6 and the butted surface 4a of the cover plate 4 are abutted. Then, a third cavity 26 is formed around these butting surfaces 6a and 4a. The third cavity 26 communicates with the second sprue 21 via the runner 22.

Under this condition, the second sprue 2
When the second injection nozzle 24 is set to 1 and a molten synthetic resin (e.g., an elastomer) having flexibility in a solidified state is injected, the molten synthetic resin is inserted into the third cavity 26 as shown in FIG. Is filled, and a covering portion 8 is formed around the butting surfaces 6a, 4a of the semi-mold fan 6 and the cover plate 4. The cover plate 8 is welded and joined to the blade main body 3 of the fan half-formed body 6 with the hollow portion 5 interposed therebetween by the covering portion 8. Then, if the mold is opened after the coating portion 8 is cooled and solidified, a propeller fan having a hollow blade structure is obtained.

In other words, according to the present embodiment, the lightweight hollow blades can be formed by simple steps such as horizontal movement of the movable mold 12 and vertical sliding movement of the slide mold 13 and mold opening and injection of molten synthetic resin. Is obtained.

The propeller fan obtained as described above is made of a flexible synthetic resin (for example, a member for joining the outer peripheral edges of the blade body 3 and the cover plate 4 constituting the hollow blade 2). The covering member 8 made of an elastomer) can also be used, and the component of the hollow blade is used to damage the portion when a hard object hits the outer periphery of the blade 2 during assembly, transportation, or use. Can be prevented.

In the above embodiment, a propeller fan having a hollow blade structure has been described, but the present invention is also applicable to a propeller fan having a structure having solid blades.

After the fan half-molded body 6 and the cover plate 4 are formed in advance by using a rigid synthetic resin, the cover plate 4
The outer peripheral edge of the fan body 3 and the blade body 3 in the fan molded body 6 may be joined via a covering portion 8 made of a synthetic resin having flexibility.

[0036]

According to the first aspect of the present invention, there is provided a propeller fan including a cylindrical boss 1 and a plurality of blades 2, 2,... 1 and the blades 2, 2,... Are integrally formed of a synthetic resin having rigidity, and a coating portion 8 made of a synthetic resin having flexibility is formed on the outer peripheral edge of each of the blades 2. Since the outer peripheral portion of the blade 2 is covered with the covering portion 8 made of a synthetic resin having flexibility,
Even when a hard object hits the outer periphery of the blade 2 during transportation, assembling, or use, there is an effect that damage to the relevant portion can be prevented.

As in the invention of claim 2, claim 1
In the propeller fan described above, when each of the blades 2 is a hollow blade having a hollow portion 5, the weight of the blade 2 can be reduced.

According to the third aspect of the present invention, there is provided a propeller fan comprising a cylindrical boss 1 and a plurality of blades 2, 2,... A rigid synthetic resin comprising a fan half-molded body 6 comprising a blade main body 3 constituting one surface side of each of the blades 2 and a cover plate 4 joined to the blade main body 3 with a hollow portion 5 interposed therebetween. And the outer peripheral edge of the lid plate 4 and the blade body 3 is joined via a covering portion 8 made of a synthetic resin having flexibility, so that the blade body forming the hollow blade 2 is formed. Since the member for joining the outer peripheral edges of the cover plate 3 and the cover plate 4 is also used as the covering portion 8 made of a synthetic resin having flexibility, during the transportation using the constituent members of the hollow blades, When a hard object hits the outer periphery of the blade 2 during assembly or use There is an effect that it is possible to prevent damage to the definitive the site.

As in the invention of claim 4, claim 1
4. The propeller fan according to claim 3, wherein a serration 11 having a sawtooth shape is formed at a position on a rear edge side of each of the blades 2 in the covering portion 8. A serration 11 having a function of rectifying the air flow at the blade trailing edge 8a is formed on the covering portion 8 to improve the aerodynamic characteristics of the blade 2 and to improve the aerodynamic characteristics of the blade 2 during transportation, assembling or use. It is possible to prevent damage to the site when a hard object is hit.

According to the fifth aspect of the present invention, in manufacturing a propeller fan including a cylindrical boss 1 and a plurality of blades 2, 2,... Since the boss 1 and the blades 2 are molded with a rigid synthetic resin, the covering portion 8 made of a synthetic resin having flexibility is joined to the outer peripheral edge of each of the blades 2. A simple method of joining a covering portion 8 made of a flexible synthetic resin to the outer peripheral edge of each of the blades 2 formed of a synthetic resin having rigidity. There is an effect that a propeller fan can be obtained that can prevent damage to the site even when a hard object hits the outer periphery.

As in the invention of claim 6, claim 5
The method for manufacturing a propeller fan according to claim 1, wherein the boss 1
When forming the blades 2, 2,...
When the inside is hollow, a lightweight propeller fan can be obtained.

According to the seventh aspect of the present invention, in manufacturing a propeller fan including a cylindrical boss 1 and a plurality of blades 2, 2,... A fan half-molded body 6 comprising a boss 1 and a blade main body 3 forming one surface side of each of the blades 2;
And the lid plate 4 joined with the hollow portion 5 interposed therebetween.
After being molded in advance with a rigid synthetic resin, the outer peripheral edges of the cover plate 4 and the blade body 3 are joined via the covering portion 8 made of a synthetic resin having flexibility. After integrally molding the fan half-molded body 6 composed of the boss 1 and the blade main body 3 with a synthetic resin having the following, the outer peripheral edge of the cover plate 4 and the blade main body 3 is covered with a flexible synthetic resin. By a simple method of joining via the portion 8, a lightweight propeller fan can be obtained which can prevent damage to the outer periphery of the blade 2 even when an object hits the outer periphery during transportation, assembly or use. This has the effect.

According to the eighth aspect of the present invention, in manufacturing a propeller fan comprising a cylindrical boss 1 and a plurality of hollow blades 2, 2,... A first cavity 14 for molding a fan half-molded body 6 in which the boss 1 and a blade body 3 constituting one surface of each blade 2 are integrated, and a hollow portion 5 is interposed in the blade body 3. A pair of molds 1 having a second cavity 15 for molding the lid plate 4 to be joined in the state of being
2, 13 and the first and second cavities 1
After injecting molten synthetic resin having rigidity in a solidified state into the molds 4 and 15 to mold the fan half-molded body 6 and the cover plate 4, the fan half-molded body 6 remains in one mold 12 and the other half. The molds 12 and 13 are arranged such that the cover plate 4 remains in the mold 13.
Are opened, and then the molds 12 and 13 are slid together to form a mold.
In this state, a synthetic resin having a solidified and flexible state is injected into the periphery of the butted surfaces 6a, 4a of the fan half-molded body 6 and the cover plate 4 to thereby form the fan half-molded body. Since the covering portion 8 for joining the cover plate 4 and the cover plate 4 is formed, the fan half-molded body 6 and the cover plate 4 which are formed of a synthetic resin having rigidity using a pair of dies 12 and 13 are formed. The covering portion 8 for joining the fan half-molded body 6 and the cover plate 4 is formed only by injecting a synthetic resin having flexibility in a solidified state around the butting surfaces 6a and 4a. Thus, the manufacturing process and the manufacturing apparatus can be simplified, and by forming the covering portion 8 which also acts as a joining member, even when an object hits the outer periphery of the blade 2 during transportation, assembly, or use. Damage the site There is an effect that lightweight propeller fan can be stopped is obtained.

As in the ninth aspect, the fifth aspect
9. The method of manufacturing a propeller fan according to claim 8, wherein each of the blades 2 is provided in the covering portion 8. 10.
When the serration 11 having a sawtooth shape is formed at a position on the trailing edge side, the serration 11 having a function of rectifying the air flow at the blade trailing edge 8a is formed on the covering portion 8 made of a synthetic resin having flexibility. Thus, it is possible to obtain a propeller fan that can prevent damage to a portion of the blade 2 when a hard object hits the outer periphery of the blade 2 during transportation, assembly, or use while improving the aerodynamic characteristics of the blade 2.

[Brief description of the drawings]

FIG. 1 is a perspective view of a propeller fan according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is an enlarged sectional view of a blade outer peripheral portion in the propeller fan according to the embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a mold matching state in the case of molding a mold half-molded fan and a cover plate used in the propeller fan manufacturing method according to the embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a state in which a mold half-mold of a mold and a cover plate used in the method of manufacturing a propeller fan according to the embodiment of the present invention are molded.

FIG. 6 is a cross-sectional view showing a mold open state after molding a mold half-molded fan and a cover plate used in the method of manufacturing a propeller fan according to the embodiment of the present invention.

FIG. 7 is a cross-sectional view showing a mold matching state during molding of the propeller fan used in the method of manufacturing a propeller fan according to the embodiment of the present invention.

FIG. 8 is a cross-sectional view showing a state in which a mold used in the method for manufacturing a propeller fan according to the embodiment of the present invention is molded with a propeller fan.

[Explanation of symbols]

1 is a boss, 2 is a blade, 3 is a blade body, 4 is a lid plate, 4a is a butt surface, 5 is a hollow portion, 6 is a half-molded fan, 6a
Is a butt surface, 8 is a covering portion, 8a is a trailing edge of the blade, 11
Is a serration, 12 is a mold (moving mold), 13 is a mold (slide mold), 14 is the first cavity, 15 is the second cavity, 16 and 18 are male molds, and 17 and 19 are female molds. , 26 are third cavities.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Eiichi Kitano 1304 Kanaokacho, Sakai-shi, Osaka Daikin Industries, Ltd. Sakai Seisakusho Kanaoka Plant F-term (reference) 3H033 AA02 BB02 BB08 CC01 DD04 DD06 DD24 DD25 DD26 EE05 EE08 EE11 EE19

Claims (9)

[Claims] 1. A cylindrical boss (1) and said boss (1)
Blades (2), (2)
A propeller fan comprising: the boss (1);
And the blades (2), (2)... Are integrally formed of a rigid synthetic resin, and each of the blades (2)
A propeller fan characterized in that a coating portion (8) made of a synthetic resin having flexibility is formed on an outer peripheral portion of the propeller fan. 2. The propeller fan according to claim 1, wherein each of the blades (2) is a hollow blade having a hollow portion (5). 3. A boss (1) having a cylindrical shape, and the boss (1)
Blades (2), (2)
A propeller fan comprising: the boss (1);
And a blade body (3) constituting one surface side of each of the blades (2)
(6) and the blade body (3)
A cover plate (4) joined with a hollow portion (5) interposed therebetween is made of a rigid synthetic resin, and an outer peripheral edge of the cover plate (4) and the blade body (3). The propeller fan is characterized in that the parts are joined via a covering part (8) made of a synthetic resin having flexibility. 4. A serration (11) having a sawtooth shape is formed at a position on a trailing edge side of each of the blades (2) in the covering portion (8). The propeller fan according to any one of the above. 5. A boss (1) having a cylindrical shape, and the boss (1)
Blades (2), (2)
In producing the propeller fan consisting of: (a), after the boss (1) and the blades (2), (2),... Are molded from a rigid synthetic resin, And a covering part (8) made of a synthetic resin having flexibility. 6. The boss (1) and blades (2), (2).
6. The method for manufacturing a propeller fan according to claim 5, wherein the inside of each of the blades (2) is hollow when forming the propeller fan. 7. A boss (1) having a cylindrical shape, and the boss (1)
Blades (2), (2)
In producing a propeller fan comprising: a fan half-molded body (6) comprising the boss (1) and a blade body (3) constituting one surface of each blade (2); and the blade body (3). ) And a lid plate (4) to be joined with a hollow portion (5) interposed therebetween, are formed in advance with a rigid synthetic resin, and then the lid plate (4) and the blade body (3) are joined together. A method for manufacturing a propeller fan, wherein an outer peripheral edge portion is joined via a covering portion (8) made of a synthetic resin having flexibility. 8. A boss (1) having a cylindrical shape, and the boss (1)
A plurality of hollow blades (2) integrally projecting from the outer periphery of the
(2) In producing a propeller fan comprising: (1) a half fan body (6) in which the boss (1) and a blade main body (3) constituting one surface of each blade (2) are integrated; A) a first cavity (14) for molding
A pair of molds (12), (2) and (3) having a second cavity (15) for molding a lid plate (4) joined with the blade body (3) interposed with a hollow portion (5) interposed therebetween. 13), the first and second cavities (14), (1)
5) Inject a molten synthetic resin having rigidity in a solidified state to form the fan half-molded body (6) and the cover plate (4), and then mold the fan half-molded body (1) in one mold (12). 6)
The molds (12) and (13) are opened so that the mold remains and the lid plate (4) remains on the other mold (13), and then the molds (12) and (13) are slid together. In this state, the fan half-molded body (6) and the cover plate (4) are abutted against each other.
The semi-molded fan body (6) and the cover plate (4) are filled with a molten synthetic resin having flexibility in a solidified state around the butting surfaces (6a) and (4a) of the butter plate and the cover plate (4). A method for producing a propeller fan, characterized in that a covering portion (8) for joining the propeller fan is formed. 9. A serration (11) having a sawtooth shape is formed at a position on the trailing edge side of each of the blades (2) in the covering portion (8). A method for producing a propeller fan according to any one of the above.