JP2003035296A - Manufacturing method of propeller fan - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a propeller fan which retains satisfactory shape precision of blade face and has high air blowing performance. SOLUTION: In the molding of a propeller fan 1 comprising two or more blades 3 mounted on the circumference of a hub 2 by injection of a molten resin into a metal mold 22, after the metal mold 22 is opened, the propeller fan 1 as a molded product left in the adhered state to the molding surface 36 of one die 32 is released from the mold by simultaneously protruding the hub 2 side and blade 3 side thereof by protruding pins 33 and 34. According to such a structure, in the blade 3, the deformation in releasing resulted from the release resistance in the part of the blade 3 is suppressed as much as possible. Consequently, the propeller fan 1 which retains a blade surface shape matched to a designed shape as much as possible and exhibits high blowing performance can be provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a propeller fan by injection molding a resin material.

[0002]

2. Description of the Related Art FIG. 3 shows a general injection molding machine 20 used for injection molding of a propeller fan. The injection molding machine 20 includes an injection unit 21 that melts a material resin and injects it, a mold 22 that molds the injection resin from the injection unit 21, and a mold that opens the mold 22 after molding. An opening / closing mechanism 23 and a protrusion mechanism 24 for ejecting a molded product after mold opening and releasing the molded product are provided.

Now, the procedure for forming the mold 22 will be described with reference to FIGS.

As shown in FIG. 4, the die 22 is a two-piece die having a fixed die 31 and a movable die 32, and the projecting pins 33, 33 are provided on the rear side of the movable die 32.・ ・ ・
And a pin unit 35 that is driven by the protrusion mechanism 24 is arranged. And the fixed mold 3
When the molten resin is injected from the injection unit 21 side into a cavity (not shown) formed between the movable mold 32 and the movable mold 32, the inner surface shape of the cavity is matched. A molded product is formed.

FIG. 5 shows a state in which after the molding, the movable die 32 is separated from the fixed die 31 and they are opened. By this mold opening, the molded product 40 is released from the fixed mold 31 side and is held on the movable mold 32 side while being attached to the molding surface thereof. Since the mold 22 is a two-piece mold composed of the fixed mold 31 and the movable mold 32, the molded product 40 has the desired product part 41 and runner part 42 (the injected resin reaches the cavity). It has been solidified between) and.

In FIG. 6, with the mold 22 opened, the pin unit 35 is driven forward, and the molded product 40 is ejected from the rear side of the molding surface by the projecting pins 33, 33 ,. It shows the state where it is released. After releasing the mold, by cutting off the runner portion 42 from the molded product 40, the target product portion 41 (as described later,
In this embodiment, a propeller fan corresponds to this).

By the way, in general, the blade surface shape of a propeller fan has a great influence on its air blowing performance, so it is designed based on extremely careful calculation from the viewpoint of ensuring air blowing performance. It is necessary to pay close attention to obtain a wing surface shape that matches the shape.

Further, as described above, when the propeller fan 1 as a molded product is ejected from the mold after being ejected by the injection pin 33, the work efficiency is usually shortened by shortening the work tact. From the viewpoint of increasing, etc., the solidification is performed in an insufficient state.
An indentation due to the projecting pin 33 remains at the projecting position of the propeller fan 1 where the projecting pin 33 abuts. When such an indentation occurs on the blade surface, for example, it is not preferable because it contributes to a decrease in air blowing performance due to the unevenness of the blade surface.

Under these circumstances, the conventional method shown in FIG.
As shown in FIG. 3, the position of the projecting pin 33 with respect to the propeller fan 1 as a molded product is set to the propeller fan 1
It was customary to set it inside the hub 2 located at the center of the.

[0010]

However, when the position of the projecting pin 33 with respect to the propeller fan 1 is set inside the hub 2 as described above, the problem of unevenness on the blade surface does not occur. However, a new problem that cannot be overlooked in securing the ventilation performance as described below will occur.

That is, when the mold is opened, the propeller fan 1 as a molded product remains with one surface of the propeller fan 1 attached to the molding surface 36 of the movable mold 32. Also, at the time of this mold opening, the propeller fan 1
The solidification of is not yet sufficient, and it has some softness.

In this state, the projecting pin 33 arranged on the back side of the movable die 32 is projected to the molding surface 36 side, and the tip of the projecting pin 33 is provided inside the hub 2 of the propeller fan 1. The propeller fan 1 is projected by the projecting pin 33, and the propeller fan 1 is forcibly released from the molding surface 36.

In this case, as shown by the solid line in the figure, with the release of the hub 2 portion, the blade 3 portion is also released simultaneously with the hub 2 portion. It is ideal in that it matches the design shape.

However, in actuality, the blade 3 portion has a larger contact area with the molding surface 36 than the hub 2 portion, and therefore the releasing resistance due to the adhesion to the molding surface 36 is also large. In addition, the bending moment of the blade 3 due to the mold release resistance of the blade 3 increases as it approaches the root. For these reasons, a broken line is shown in the figure (reference numeral 3 ').
As described above, in the blade 3, the root portion of the blade 3 is gradually bent and deformed downward as the mold release of the hub 2 progresses, and the blade 3 is completely solidified by the heat radiation after the mold release. Is fixed. That is, the shape deformed at the time of release becomes the blade surface shape of the blade 3 as a product as it is.

As a result, the propeller fan 1 as a product
In the above, the blade surface shape is different from the originally designed shape, and the air blowing performance is reduced accordingly.

However, an effective means for suppressing the deformation of the blade portion peculiar to such injection molding of a propeller fan has not been proposed yet.

Therefore, the present invention has been made for the purpose of proposing a method for manufacturing a propeller fan capable of manufacturing a propeller fan having good blade surface shape accuracy and high blowing performance.

[0018]

In the present invention, the following constitution is adopted as a concrete means for solving such a problem.

In the first invention of the present application, the propeller fan 1 having a plurality of blades 3, 3, ... Attached to the outer periphery of the hub 2 is molded by injection of molten resin into the mold 22. In the method for manufacturing a propeller fan described above, after the mold 22 is opened, the propeller fan 1 as a molded product remaining in an adhered state on the molding surface 36 of one mold 32 of the mold 22 is attached to the hub 2 side. And the blade 3 side are simultaneously projected by the projecting pins 33 and 34 to form the molding surface 36.
The feature is that it is released from the mold and released.

According to a second invention of the present application, in the method for manufacturing a propeller fan according to the first invention, the blade 3 is provided.
The arrangement position of the protruding pin 34 on the side is set to the root portion 3c of the blade 3.

According to a third invention of the present application, in the method for manufacturing a propeller fan according to the first invention, the blade 3 is provided.
The position of the protruding pin 34 on the side is set to a position near the front edge 3a of the blade 3.

According to a fourth invention of the present application, in the method for manufacturing a propeller fan according to the first invention, the blade 3 is provided.
The serration 9 is provided on the trailing edge 3b side, and the protruding pin 34 is made to correspond to the vicinity of the trailing edge 3b.

In the fifth invention of the present application, the above-mentioned first, second, and
In the method for manufacturing a propeller fan according to the third or fourth aspect of the invention, the protruding pin 34 is attached to each of the blades 3, 3, ...
A feature is that a plurality of them are provided for each.

[0024]

According to the present invention, the following effects can be obtained by adopting such a configuration.

In the method for manufacturing a propeller fan according to the first invention of the present application, after the mold 22 is opened, a molded product that remains in an adhered state on the molding surface 36 of one mold 32 of the mold 22 is obtained. The propeller fan 1 is detached from the molding surface 36 by ejecting the hub 2 side and the blade 3 side simultaneously by the projecting pins 33 and 34, and the propeller fan 1 is released.

Therefore, according to the method for manufacturing the propeller fan of the present invention, the hub 2 side is projected by the projecting pin 33, and at the same time, the blade 3 side is also projected by the projecting pin 34. For example, as in the prior art, only the hub 2 side is provided with the protruding pin 33.
The deformation of the blade 3 portion due to the release resistance of the blade 3 portion is minimized as compared with the configuration in which the propeller fan 1 as a product conforms to the design shape as much as possible. The wing shape will be retained.

The protruding pin 34 on the blade 3 side is additionally provided to the protruding pin 33 on the hub 2 side, and the protruding force required for the protruding pin 34 on the blade 3 side is For example, as compared with the case of projecting only the blade 3 side, the size can be remarkably reduced. Therefore, the depth of the indentation due to the protrusion of the protruding pin 34, that is, the unevenness of the blade surface is extremely small, and the presence of the indentation The influence on the blowing performance is small.

As a synergistic effect of both of them, according to the method for manufacturing a propeller fan of the present invention, it is possible to provide a propeller fan having good blade surface shape accuracy and high air blowing performance.

According to the method for manufacturing a propeller fan according to the second invention of the present application, in addition to the effects described above, the following unique effects can be obtained. That is, in the method for manufacturing a propeller fan of the present invention, the position of the projecting pin 34 on the blade 3 side is set to the root portion 3c of the blade 3. In this case, the root portion 3c of the blade 3 is
The bending moment due to the mold release resistance is the largest of the respective portions of the blade 3, and the thickness of the blade 3 is large and the portion is soft and easily deformed due to the delay of the solidification. By disposing the projecting pin 34 and projecting the projecting pin 34, it is possible to more effectively suppress the deformation of the blade 3 due to the mold release resistance, and it is possible to provide a propeller fan having higher air blowing performance.

According to the propeller fan manufacturing method of the third invention of the present application, in addition to the effects described above, the following unique effects are obtained. That is, in the method of manufacturing a propeller fan of the present invention, the position of the protruding pin 34 on the blade 3 side is set to a position near the front edge 3a of the blade 3. In this case, the front edge 3 of the blade 3
Since the position near a is the largest in the thickness of each part of the blade 3 and is soft and easily deformed due to the delay in its solidification, the protruding pin 3 is located near the front edge 3a.
By disposing 4 and projecting this, it is possible to effectively suppress the deformation of the blades 3 due to the release resistance, and it is possible to provide a propeller fan having a higher blowing performance.

According to the method for manufacturing a propeller fan according to the fourth invention of the present application, the following peculiar effect is obtained in addition to the above-described effects. That is, in the method for manufacturing a propeller fan of the present invention, the serration 9 is provided on the trailing edge 3b side of the blade 3, and the protruding pin 34 is made to correspond to the vicinity of the trailing edge 3b. in this case,
On the side of the trailing edge 3b of the blade 3, where the serrations 9 are provided, there is a large parting resistance from the molding surface 36, and the protruding pin 34 is arranged here and protruded by this. Despite the presence of a large mold release resistance on the trailing edge 3b side, the mold release resistance is
It is possible to more effectively reduce the influence on the deformation of the propeller fan, and it is possible to provide a propeller fan having high blowing performance.

According to the method for manufacturing a propeller fan according to the fifth aspect of the present invention, the following peculiar effect is obtained in addition to the effect described in the above or. That is, in the method for manufacturing a propeller fan according to the present invention, since the plurality of protruding pins 34 are provided for each of the blades 3, 3, ... The protrusion force of the protrusion pin 34 is reduced, and thus the generation of the indentation due to the protrusion of the protrusion pin 34 is suppressed. As a result, it is possible to provide a propeller fan having a high blowing performance, in which the reduction of the blowing performance due to the unevenness of the blade surface is suppressed as much as possible.

[0033]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below based on preferred embodiments.

FIG. 1 shows a propeller fan 1 manufactured by the manufacturing method according to the present invention. The propeller fan 1 is a resin-integrally molded product, and as shown in FIG. 2, has a peripheral wall 5 and an end face wall 6 and has an end face wall 6.
Is provided with a hub 2 having a substantially bottomed cylindrical shape having a boss 4 at the center thereof, and three blades 3, 3, ... Integrally mounted on a peripheral wall 5 of the hub 2. It is constructed and molded by injection molding. Further, inside the hub 2 of the propeller fan 1, a plurality of pin receiving portions 7, 7, ... Supported by a plurality of ribs 8, 8, ... Radially extending from the boss 4 toward the peripheral wall 5.・ Is provided. Further, the blade 3 is a thin blade, and a serration 9 is provided on the trailing edge 3b. In this embodiment, the blade 3 is a thin blade, but the invention of the present application is not limited to such a configuration, and it goes without saying that the blade 3 may be a thick blade.

The propeller fan 1 has the above

2. Description of the Related Art As described above in the section of "Prior Art", it is manufactured using the injection molding machine 20 shown in FIG. 3 and through the working steps shown in FIGS. The manufacturing method of this embodiment is different from the conventional manufacturing method in the step of releasing the molded product, that is, the propeller fan 1 after injection molding and mold opening.

That is, in the manufacturing method of this embodiment, as shown in FIGS. 4 to 5, injection molding is carried out using the mold 22 provided in the injection molding machine 20, but in that case, after molding, In the mold open state, the propeller fan 1 remains attached as a molded product 40 on the movable die 32 side of the fixed die 31 and the movable die 32 of the die 22. Then, the propeller fan 1 remaining on the movable die 32 side is released from the movable die 32 side by the pin unit 35. The greatest feature of the manufacturing method of the present invention is in the releasing step of the propeller fan 1. is there.

Specifically, as shown in FIG. 2, a plurality of projecting pins 33, 33, ... And a plurality of projecting pins 33, 33, ... Are provided on the pin unit 35 (see FIG. 3) arranged on the back side of the movable die 32. .. are provided, and these two types of projecting pins 33, 34 are simultaneously operated to separate the propeller fan 1 from the molding surface of the movable die 32. In this case, of the two types of projecting pins 33, 34, one of the projecting pins 33, 33, ... Corresponds to each of the pin receiving portions 7, 7, ... Of the propeller fan 1. While the arrangement position is set, each of the other protruding pins 34, 34, ...
・ The placement position is set to correspond to.

That is, in this embodiment, the protruding pin 3 is used.
4 corresponds to each of the above-mentioned blades 3, 3, ...
As indicated by a broken line ellipse in FIG. 1, 0 is provided at a plurality of positions along the front edge 3a on the front edge 3a side of the blade 3, and at a plurality of positions along the rear edge 3b on the trailing edge 3b side. On the root portion 3c side, a plurality of positions are set along the peripheral wall 5 of the hub 2 respectively.

After opening the mold, the pin unit 35
Is operated, and the protruding pins 33, 3 provided on the
.. and the respective projecting pins 34, 34, .. .. penetrate the movable die 32 and project toward the molding surface 36 side, and the projecting pins 33, 33 ,. Three
The hub 2 side of the propeller fan 1 and the blades 3, 3, ... Side of the propeller fan 1 are simultaneously projected by 4, 4 ,.

As described above, the manufacturing method of this embodiment is
At the time of releasing the propeller fan 1, the greatest feature is that the hub 2 side of the propeller fan 1 and the respective blades 3, 3, ... Side are projected at the same time. Such a unique effect can be obtained.

That is, in this manufacturing method, after the mold 22 is opened, the propeller fan 1 remaining in the adhering state on the molding surface 36 of the movable mold 32 is attached to each of the projecting pins 33 on the hub 2 side thereof. , 33, ... At the same time, the blade 3 side is ejected at the same time by each of the projecting pins 34, 34 ,. As compared with the structure in which only the hub 2 side is projected by the projecting pins 33, 33, ... As described above, the deformation of the blade 3 due to the mold release resistance of the blade 3 portion is minimized. As a result, the propeller fan 1 has a blade surface shape that matches the design shape as much as possible, and exhibits high air blowing performance as designed.

The projecting pin 34 installed corresponding to the blade 3 side is additionally provided to the projecting pin 33 installed corresponding to the hub 2 side.
The projecting force required for the projecting pin 34 on the blade 3 side can be made significantly smaller than, for example, the case of projecting only the blade 3 side. Therefore, the projecting pin 34 projecting force causes the blade surface of the blade 3 to project. The depth of the indentation, that is, the unevenness of the blade surface, is extremely small. Therefore, the presence of the indentation has a small effect on the air blowing performance and has no practical problem.

In the manufacturing method of this embodiment, the positions of the protruding pins 34 with respect to the blades 3 are set so that the blades 3 have the leading edge 3a side and the trailing edge 3b side and the root portion 3c.
Although they are set on the respective sides, specific effects such as the following (a) to (c) can be obtained for each of these arrangement positions.

(A) The vicinity of the front edge 3a of the blade 3 is a portion having the largest wall thickness among the respective portions of the blade 3 and is soft and easily deformed due to the delay of its solidification. Therefore, by disposing the projecting pin 34 in the vicinity of the front edge 3a and projecting the projecting pin 34, the deformation of the blade 3 due to the releasing resistance can be suppressed more effectively.

(B) On the trailing edge 3b side of the blade 3, the serration 9 is provided so that the releasing resistance from the molding surface 36 is large. Therefore, this trailing edge 3
By arranging the protruding pin 34 on the b side so that the protruding pin 34 protrudes, the influence of the release resistance on the deformation of the blade 3 regardless of the presence of a large release resistance on the trailing edge 3b side. Will be more effectively diminished.

(C) The root portion 3c of the blade 3 has the largest bending moment due to the releasing resistance among the respective portions of the blade 3 and has a large thickness and is soft and deformed due to a delay in solidification. It is a part that is easy to do, but in this case,
By causing the root portion 3c of the blade 3 to correspond to the protruding pin 34 and projecting the root portion 3c, it is possible to more effectively suppress the deformation of the blade 3 due to the release resistance.

The effects (a) and (c) are particularly remarkable when the blade 3 has a thick blade structure in which the delay of solidification of the molten resin is large.

On the other hand, in the manufacturing method of this embodiment, since a plurality of the projecting pins 34 are provided for each of the blades 3, 3, ..., The number of the projecting pins 34 arranged is large. The protrusion force at each protrusion pin 34 is reduced, and the generation of indentations due to the protrusion of the protrusion pins 34 is suppressed to that extent, and the deterioration of the air blowing performance due to the presence of the indentations is minimized as much as possible.

[Brief description of drawings]

FIG. 1 is a perspective view of a propeller fan manufactured by a manufacturing method of the present invention.

FIG. 2 is a diagram illustrating a mold release state of a propeller fan.

FIG. 3 is an overall view of an injection molding machine.

FIG. 4 is an explanatory diagram of a mold closed state of the mold unit.

FIG. 5 is an explanatory diagram of a mold opening state of the mold unit.

FIG. 6 is an explanatory diagram of a mold release state of a molded product from a mold unit.

FIG. 7 is an explanatory view of a product state at the time of mold release in the conventional manufacturing method.

[Explanation of symbols]

1 is a propeller fan, 2 is a hub, 3 is a blade, 4 is a boss,
5 is a peripheral wall, 6 is an end wall, 7 is a pin receiving portion, 8 is a rib, 9 is serration, 10 is a pin receiving position, 20 is an injection molding machine,
21 is an injection unit, 22 is a mold, 23 is a mold opening / closing mechanism,
Reference numeral 24 is a protruding mechanism, 31 is a fixed type, 32 is a movable type, 33 and 34 are protruding pins, 35 is a pin unit, 36 is a molding surface, 40 is a molded product, 41 is a product part, and 42 is a runner part.

Claims (5)

[Claims] 1. A propeller fan (1) having a plurality of blades (3), (3), ... Attached to the outer circumference of a hub (2) by injecting molten resin into a mold (22). A method of manufacturing a propeller fan for molding, wherein after the mold (22) is opened, it remains in an adhered state on the molding surface (36) of one mold (32) of the mold (22). The propeller fan (1) as a molded product is provided with a protruding pin (3) on the hub (2) side and the blade (3) side at the same time.
3) and (34), the molding surface (3
6) A method for producing a propeller fan, characterized in that the propeller fan is released from the step 6) and is released from the mold. 2. The propeller fan according to claim 1, wherein an arrangement position of the protruding pin (34) on the blade (3) side is set at a root portion (3c) of the blade (3). Production method. 3. The blade according to claim 1, wherein the position of the protruding pin (34) on the side of the blade (3) is set near the front edge (3a) of the blade (3). Propeller fan manufacturing method. 4. The serration (9) according to claim 1, on the trailing edge (3b) side of the blade (3).
Is provided, and the protruding pin (34) corresponds to the vicinity of the trailing edge (3b). 5. The method according to claim 1, 2, 3 or 4, wherein the protruding pin (34) comprises the blades (3), (3) ,.
A method for manufacturing a propeller fan, characterized in that a plurality is provided for each.