JPH1110683A - Mold device for injection molding of overlap fan - Google Patents

Abstract

PROBLEM TO BE SOLVED: To mold an overlap fan through injection molding as a single synthetic resin molded form. SOLUTION: A mold device 10 has a large number of blades, having the configuration of advancing blades and the like which are projectingly provided radially on the outer peripheral surface of a boss unit 2 so as to be slanted into the rotating direction of a fan, and molds an overlap fan 1, whose one parts of respective blades are overlapped with the neighboring blades of the same in the direction of axial line of rotation. In this case, a stationary mold 11 and a movable mold 12, opened and closed freely in the opening and closing direction Z of the mold, as well as slide molds 13, arranged between neighboring blades 2 respectively and formed so as to have configurations contacted annularly with each other upon mold clamping while movable into radial direction W, are provided while a cavity, coping with the boss unit 2, is formed of the stationary mold 11 and the movable mold 12. Further, cavities 14b, coping with respective blades, are formed between the neighboring slide molds 13 and the profiling surface 11a of the stationary mold 11 (movable mold 12), which are formed so as to cope with parts including the end rim surfaces of respective expanded blades 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthetic resin overlap fan, that is, an injection mold apparatus for an axial flow fan in which a part of each blade is axially overlapped with an adjacent blade. More particularly, the present invention relates to an injection molding die apparatus for an overlap fan in which each blade is formed as a forward wing or the like.

[0002]

2. Description of the Related Art As a blower fan for cooling a radiator of an automobile, an axial fan, that is, a boss portion is provided on an outer peripheral surface of the boss portion so as to project radially and inclined with respect to the rotation direction. Fans with multiple (usually several) blades are commonly used.

[0003] Such a fan is formed by injection-molding a synthetic resin material such as polypropylene. Specifically, a fixed mold and a movable mold that can be opened and closed in the mold opening and closing direction are formed. Using the equipped injection molding die equipment,
By injecting a molten synthetic resin material into a cavity having a shape corresponding to a fan formed therebetween, it is formed as an integral molded product made of synthetic resin.
Note that the cavity is formed from the shape of a fan having radial blades, with its axis of rotation coinciding with the mold opening and closing direction.

In this type of fan, in particular, in the case of a fan for cooling a radiator, a higher air volume can be obtained and the rotation of the fan can be increased in accordance with the recent sophistication and sophistication of automobiles. It is important and required that less noise be generated at times. For this reason, the blades of this type of fan are generally formed with approximately the same width from the root to the tip, but recently, in order to reduce the noise with the increase of the air flow, the edges in the rotation direction are cut. In many cases, the wings are partially expanded (increased blade width) to have an irregular shape protruding toward the leading edge or the trailing edge. A typical example of such a blade shape is a shape referred to as a “advanced wing”, in which the leading edge of the blade is gradually expanded from a substantially central portion to the tip in the radial direction, and bulged forward in the rotational direction. is there.

On the other hand, by increasing the number of blades protruding from the outer peripheral surface of the boss portion, a larger air volume can be obtained, and the noise can be relatively reduced. . However, when a large number of blades are arranged on the outer peripheral surface of the boss portion, depending on the diameter of the boss portion, etc., part of the adjacent blades (particularly, the root portion) overlap in the rotation axis direction, Overlap when viewed in the direction of the rotation axis. Then, such a fan in which a part of the adjacent blades overlaps in the direction of the rotation axis, that is, an overlap fan, in a general mold device including a fixed mold and a movable mold,
Since the overlapping portion of the blade cannot be formed by the mold on either side, injection molding cannot be performed as a single synthetic resin molded body.

Accordingly, Japanese Utility Model Laid-Open No. 2-99295 and Japanese Utility Model Laid-Open No. 63-160392 disclose an overlap fan in which a large number of such blades are arranged so as to partially overlap in the rotation axis direction. It has been proposed to form the halves and then assemble and integrate the halves together. Specifically, this method has half the blades on the outer peripheral surface of the boss portion having a width approximately half of that of the overlap fan to be finally obtained (therefore, the blades overlap in the rotation axis direction). No) The fan halves made of synthetic resin are formed in advance, and then the fan halves are integrated by fastening or adhesively bonding them with their rotation axes aligned.

[0007]

As described above, in the fan having the boss portion and the blade protruding radially on the outer peripheral surface of the boss portion and inclined with respect to the rotation direction. By increasing the number of blades and arranging more blades on the outer peripheral surface of the boss portion so that a part of the blades overlaps in the rotation axis direction, a higher air volume can be obtained and noise can be reduced. be able to.

However, manufacturing such an overlap fan by the method disclosed in Japanese Utility Model Application Laid-Open No. 2-99295 or the like involves fixing a pair of preformed fan halves to each other or bonding them together. Not only is it necessary to increase the number of man-hours and the production efficiency is low, but also it is not easy to secure the accuracy and strength (durability) of the fixed portion or the joint portion between the fan halves. That is, it is desirable that even such an overlap fan in which a number of blades are arranged to overlap in the direction of the rotation axis is formed as a single synthetic resin molded body as in the case of a normal fan.

In accordance with this, even in the case of such an overlap fan, the blades are provided on the leading edge side and the trailing edge side of the above-mentioned forward wing and the like in order to further increase the air volume and reduce the noise. It is preferable that at least one edge is partially expanded.

Accordingly, the present invention provides an overlapping fan having a shape in which a number of blades are arranged so as to overlap with each other in the direction of the rotation axis and each of the blades is partially expanded. It is an object of the present invention to provide a mold device for injection molding of an overlap fan that can be molded as a mold.

[0011]

SUMMARY OF THE INVENTION Basically, the above-mentioned object is achieved by forming a boss between a fixed mold and a movable mold, and forming a blade overlapping in the rotation axis direction in a radial direction. In this case, at least the edge surface of the wing-spread portion, which is undercut in the radial direction, is formed by the die-cut surface of the fixed-side or movable-side mold. Can be solved.

That is, according to the first aspect of the present invention, there is provided a mold apparatus for injection molding of an overlap fan, wherein a boss portion is provided on an outer peripheral surface of the boss portion so as to protrude radially and inclined with respect to the rotation direction. A plurality of blades having at least one of a leading edge side and a trailing edge side having a partially widened shape, each of which partially overlaps with an adjacent blade in the rotational axis direction. In a mold apparatus for molding an overlapping fan made of synthetic resin by injection molding, a fixed mold and a movable mold that can be opened and closed in the mold opening and closing direction, respectively, and between adjacent blades. And a radially movable slide mold formed in a shape that comes into annular contact with each other at the time of mold clamping, and a cavity corresponding to the boss portion by the fixed mold and the movable mold. To And a cavity corresponding to each blade is formed in a fixed mold or a movable mold corresponding to a slide mold adjacent to each other and a portion including an edge surface on the blade-expanded side of the blade. It is designed to be formed between the carved surface.

According to a second aspect of the present invention, there is provided an injection mold apparatus for an overlap fan according to the first aspect, wherein each of the slide dies and the fixed-side mold or the movable-side mold having the engraved surface is formed. The parting line is set so as to extend further along the side surface of the blade bordering the above-mentioned edge surface, beyond the portion where the side surface protrudes most in the rotation direction.

As described above, the mold apparatus for injection molding of the overlap fan according to the present invention is provided with the slide mold movable in the radial direction in addition to the fixed mold and the movable mold. Forming, on the fixed mold or the movable mold, a die-sinking surface corresponding to a portion including the leading edge side or the trailing edge side of the blade, and then forming the boss portion on the fixed side mold. Each blade is formed between the mold and the movable mold, and each blade is formed between the slide molds adjacent to each other and between these and the molding surface of the fixed mold or the movable mold. Therefore, even if the overlapping fan has a blade including an edge surface that partially overlaps in the direction of the rotation axis and partially expands and radially undercuts, a single synthetic resin It can be molded as a molded article. According to the second aspect, by simply changing the surface shape of the engraving surface, it is possible to variously change the length, shape, and the like of the blades.

[0015]

Embodiments of the present invention will be described below.

FIGS. 1 to 7 show an injection mold apparatus for an overlap fan according to an embodiment of the present invention and the overlap fan itself to be molded. And
FIG. 1 is a virtual exploded cross-sectional view showing the essential parts of the mold apparatus in a virtually developed manner. FIG. 2 is a sectional view of the mold apparatus taken along the line AA in FIG. FIG. 3 is a sectional view of the main part (longitudinal section), and FIG. 3 is a cross-sectional view of the main part (cross-sectional view) of the mold apparatus cut along a line BB (a direction perpendicular to the mold opening / closing direction) of FIG. Figure). 4 is a perspective view showing the entire overlap fan, FIG. 5 is a plan view showing the overlap fan viewed from the suction side, and FIG. 6 is a cross-sectional view showing the overlap fan cut along a plane including the rotation axis. FIG. 7 is a virtual development plan view showing the overlap fan virtually developed and viewed from the outer peripheral side.

As shown in the figure, the injection molding apparatus of the present embodiment, generally designated by 10, is an overlap fan 1 used as, for example, a radiator cooling fan of an automobile.
First, the molded overlap fan 1 itself will be described.

As shown in FIGS. 4 to 7, the overlap fan 1 has a boss 2 having a cylindrical outer peripheral surface, and a plurality of (herein, bosses) radially projecting from the outer peripheral surface of the boss 2. , Eight) blades 3 and are integrally molded from a synthetic resin material such as polypropylene resin.
The boss portion 2 is specifically formed in the shape of a concentric double boss, and a metal bush 4 is reinforced on the center boss to which the drive shaft is inserted and connected. Inserted in. However, the boss portion 2 only needs to have a cylindrical outer peripheral surface on which the blade 3 is protruded, and the specific shape and structure of the boss portion 2 depend on the connection structure to a rotary drive member including a rotary shaft. And can be appropriately designed. The outer peripheral surface of the boss 2 may be substantially cylindrical (columnar), and may be, for example, a conical outer surface inclined to some extent toward the suction side or the discharge side.

FIG. 7 is a plan view when the cylindrical boss portion 2 in which the blades 3 are integrally connected radially is developed virtually flat, as shown in FIG.
Each blade 3 is formed in the shape of an airfoil (wing),
That is, it is formed with a warp (warp), and its circumferential cross section (rotational cross section, width cross section) around the boss portion 2 has a gentle arc shape. More specifically, each blade 3 has a predetermined thickness in terms of strength, and therefore, each blade 3 radially projecting on the outer peripheral surface of the boss portion 2 has a slightly convexly curved front side surface, that is, A front side surface 3a facing the suction side, a back side surface facing the front side surface 3a and curved gently concavely, that is, a back side surface 3b facing the discharge side, and a front side surface 3a; An edge surface that connects the side edges of the back side surface 3b to each other, that is, a front edge surface 3c that is on the front side (front edge side) with respect to the rotation direction of the fan 1 and a rear edge that is also on the rear side (rear edge side). Surface 3d and, furthermore, front side 3
a and the back side surface 3b are provided with a top edge surface 3e for connecting the radial top edges to each other. The front edge surface 3c, the rear edge surface 3d, and the top edge surface 3e that mutually join the edges of the front side surface 3a and the back side surface 3b that are substantially parallel to each other are all rounded shapes, that is, It is formed as a smooth surface curved in a round shape, thereby suppressing the generation of turbulent flow during rotation of the fan and the reduction in strength due to stress concentration. The round shape is touched later.

Each of the blades 3 has its slightly concave back side surface 3b directed toward the positive pressure side (discharge side).
Further, in a state facing forward in the rotation direction, the fan 1 is inclined at a predetermined angle with respect to the rotation plane of the fan 1 so as to be entirely radial, that is, perpendicular to the rotation axis of the fan 1 set for each blade 3. Extending in a direction along a single reference axis 5. In other words, the front side surface 3a and the back side surface 3b of each blade 3 extend in parallel with the reference axis 5, which is the reference axis in the radial direction (radial direction) of the fan 1. However, the reference shaft 5 does not necessarily need to be perpendicular to the rotation axis of the fan 1 and may be slightly inclined or offset. The reference shaft 5 can be generally set substantially at the center of the blade 3, but may be another part such as an end. Here, the angle of inclination (mounting angle) of each blade 3 with respect to the rotation direction can be appropriately determined in general in the range of 10 to 60 degrees according to the required air volume and the like. Preferably, the angle is relatively small.

Each of the blades 3 has an increased air flow, and its tip portion bulges forward with respect to the rotation direction in order to prevent separation of the boundary layer at the tip portion in the radial direction and suppress eddy noise. To form a forward wing which is widened. That is, the leading edge surface 3c of each blade 3 is
The portion from the base to the center in the radial direction (base side) is substantially in the range on the outer peripheral surface of the boss 2 as shown by the dotted line in FIG. 7 (only slightly from the outer peripheral edge of the boss 2). Protruding), and substantially parallel to the reference axis 5, but the portion from the center to the tip (tip side) gradually expands forward in the rotational direction to have a substantially maximum width at the tip. As a result, the boss 2 protrudes toward the suction side from the edge of the outer peripheral surface of the boss 2. Meanwhile, the trailing edge surface 3 d of each blade 3 is parallel to the reference axis 5. That is, the front side surface 3a, the back side surface 3b, and the rear edge surface 3 of the blade 3
Although d is parallel to the reference axis 5, only the leading edge surface 3 c is not parallel to the reference axis 5, but expands and bulges forward (leading edge side) in the rotation direction at the tip side of the blade 3.

And, in order to obtain more airflow,
A large number (eight) of blades 3 having such a shape are provided on the outer peripheral surface of the boss portion 2. Therefore, when each of the blades 3 is projected and viewed in the rotation axis direction of the fan 1,
Partially overlapped with the adjacent blades 3, that is, they are arranged so as to overlap. Specifically, as shown in FIG. 5, the root portion on the leading edge surface 3c side of the blade 3 overlaps the root portion on the trailing edge surface 3d side of the adjacent blade 3. Note that the size (width) of the overlapping portion depends on the number and width of the blades 3 and, if the tip of the blade 3 formed as a forward wing has a large swelling, this portion will be reduced. May overlap.

As described above, the overlap fan 1 to be formed or formed by the injection molding die apparatus 10 of the present embodiment includes a boss 2 having a cylindrical outer peripheral surface, and the boss 2. Blades 3 projecting radially on the outer peripheral surface of the member and inclined with respect to the rotation direction
And each of these blades 3 is formed in the shape of a forward wing capable of obtaining a high air flow and suppressing the generated noise, and is composed of a large number of blades in order to obtain a larger air flow. Some of them are arranged overlapping. Therefore, such an overlap fan 1
An ordinary mold device simply provided with a fixed mold and a movable mold that open and close in the direction of the rotation axis of the fan 1 cannot form the overlap portion.

Therefore, as shown in FIGS. 1 to 3, the injection molding die apparatus 10 of the present embodiment is provided with a fixed die 11 that can be opened and closed in the rotation axis direction of the overlap fan 1 to be molded. In addition to the side mold 12, a slide mold (side mold) 13 movable in the radial direction W for forming the overlapping blades 3 is provided.

Here, the virtual development sectional view of the mold in FIG. 1 corresponds to FIG. 7 which is a virtual development plan view of the fan 1 in order to show the mutual arrangement structure of the molds forming the blade 3. It is described in a similar manner. That is, FIG. 3 shows that the mold apparatus 10 in the mold-clamped state is centered on the mold center line (the rotation axis of the fan 1) which coincides with the mold opening / closing direction Z, and the mold apparatus 10 is cut along the line CC of FIG. 7, the cavities corresponding to the bosses 2 are imagined so that the cavities forming the blades 3 are parallel to each other as in the case of FIG. Unfolded flat (assuming the mold part as a space)
This is shown from the outer peripheral side. Therefore, the illustrated virtual expanded cross-sectional shape of each mold portion corresponds to a shape obtained by expanding an annular cross section immediately above the outer periphery of the boss portion 2, and in particular, the slide mold 13 has a shape obtained by expanding the inner end face thereof. Is equivalent.

More specifically, as shown in FIG. 2, the fixed mold 11 and the movable mold 12 are mutually connected in the mold opening / closing direction Z in the same manner as a general injection molding machine. The mold can be freely clamped and opened, and at the time of mold clamp, a cavity 14 corresponding to the overlap fan 1 is defined and formed. A gate, a sprue, a runner, and the like (not shown) are formed on the fixed mold 11 side to inject the molten resin material into the cavity 14, which is the molding space. The fixed mold 11 is a normal one-stage sprue mold.
Alternatively, it can be configured as a two-stage sprue type having a payout plate. The movable die 12 is provided with an ejector pin and the like (not shown) for pushing out the fan 1 after molding.

The fixed-side mold 11 and the movable-side mold 12 specifically have cavities corresponding to the double boss-shaped boss portion 2 of the components of the overlap fan 1. 14a is formed. Further, here, the cavity 14a is formed such that the suction side (front side) of the fan 1 is on the fixed side mold 11 side and the discharge side is on the movable side mold 12 side. It is formed so as to match the opening / closing direction Z.

The blades 3 whose roots overlap in the direction of the rotation axis are provided with a plurality of (in this case, eight) slide metal members each of which is movable in the radial direction W, that is, the number of blades 3 is equal to the number of blades 3. Formed by the mold 13.

More specifically, as shown in FIG. 3 (and FIG. 1), each of the slide dies 13 is connected to the adjacent blade 3.
Each of the blades 3 is formed in the form of a block having a truncated wedge-like cross-sectional shape, which is disposed in a ring-like shape, and has a substantially radially extending side surface. Cavity surfaces corresponding to 3a and the other back surface 3b are respectively formed. That is, when the side facing the one direction according to the annular arrangement direction of each slide mold 13 is the front surface 13a and the side facing the other direction is the rear surface 13b, the front surface 13a and the rear surface 13b And the front side surface 3a of the blade 3 adjacent to the front side in the rotation direction of the blade 3 are formed. Thus, they are each parallel to the reference axis 5 of the corresponding blade 3 and make a 45 degree angle with each other.
In FIG. 1 which is a virtual view corresponding to FIG. 7, the front surface 13a and the rear surface 13b are shown closest to each other, but the actual annular cross section of each slide mold 13 in the radial direction is shown. The developed shape is such that the front surface 13a and the rear surface 13b are separated from each other as they become radially outward portions while maintaining their shapes (the length of the side end surface is increased).
It becomes a contour shape. And each of these slide molds 13
Can be freely moved in any radial direction W between adjacent blades 3, that is, in a range between the reference axes 5. The blade 3 on the side that forms 3b is movable in the radial direction W along the reference axis 5 of the blade 3.

In particular, as shown in FIG. 2, each of the slide molds 13 is formed so as to be arranged between the fixed mold 11 and the movable mold 12 with their side end surfaces in contact with each other.
The radially inner end face straddles the fixed mold 11 and the movable mold 12 and abuts thereon, and forms a cavity surface corresponding to the outer peripheral surface of the boss 2 of the fan 1 at the abutting position. Have been to be. That is, the inner end surface of each slide mold 13 is formed as an arc surface having a curvature corresponding to the outer peripheral surface of the boss portion 2, and both sides thereof are movable with the fixed mold 11 during mold clamping (at the time of molding). The boss portion 2 formed on the side mold 12 is supported in close contact with a cylindrical support surface having a diameter equal to the outer peripheral surface of the boss portion 2, and a cavity surface corresponding to the outer peripheral surface of the boss portion 2 is formed by an intermediate portion thereof. Has been. In this way, the slide molds 13 are arranged with their end faces in contact with the fixed mold 11 and the movable mold 12 at the time of mold clamping (at the time of molding), and the inner end face straddles between them. The boss portion 2 is supported in close contact with the outer peripheral surface of the boss portion 2 to form a cavity surface, and is also closely contacted in an annular direction with each other between the front surface 13a and the rear surface 13b of the adjacent slide mold 13. Cavity 14 corresponding to blade 3
b is formed.

However, in more detail, as shown in FIG. 1, a portion of the cavity 14b on the front edge side (rotational rotation) protruding outward in the axial direction from the range on the outer periphery of the boss portion 2 of each blade 3. The cavity corresponding to the front portion in the direction, FIG. 7) is formed between the slide mold 13 and the fixed mold 11. That is, the cavity surface corresponding to the back surface 3b of the protruding portion of each blade 3 is formed by the front surface 13a of the slide mold 13 continuously with the back surface 3b in the range on the outer peripheral surface of the boss portion 2. The entire surface of the protruding portion other than the back side surface 3b, that is, the cavity surface corresponding to the front side surface 3a, the top edge surface 3e, and the front edge surface 3c has a shape in which the front edge surface 3c is undercut in the radial direction. Therefore, it is formed on the side of the fixed-side mold 11 as the engraving surface 11a. Therefore, the parting line (parting surface, division surface, mating surface) PL1 between the front surface 13a of each slide mold 13 and the fixed mold 11 as viewed from the radial direction is bounded by the R-shaped front edge surface 3c. Thus, it is formed in a shape (arc shape) that curves slightly convexly along the back side surface 3b of the blade 3. The parting line PL2 between the rear surface 13b of the slide mold 13 and the fixed mold 11 is connected to the blade 3 adjacent to the front in the rotation direction.
Is formed in a linear shape extending in the mold opening / closing direction Z from the boundary on the edge of the boss portion 2 on the front side surface 3a, and is connected to the parting line PL1.

Here, the front surface 1 of each slide mold 13
Parting line PL1 between 3a and fixed mold 11 is
Basically, the rear side surface 3b can be set in a range up to the portion most protruding in the front edge direction. In the present embodiment, however, the parting line PL along the rear side surface 3b is provided.
1 is set so as to extend further in the direction in which the blade 3 protrudes (blade spreading direction) beyond the maximum protruding portion as shown in FIG. That is, the front surface 13a on the fixed mold 11 side of each slide mold 13 is a slightly curved surface corresponding to the back surface 3b of the blade 3 and extends to a point where the radially inner tip crosses the parting line PL2. It is formed. Therefore, by setting the parting line PL1 in this manner, a plurality of types of overlapping fans 1 having different protruding lengths in the leading edge direction of the blade 3 formed as a forward wing can be moved to the slide mold 13 Surface 1 in the fixed mold 11 without changing
It can be easily formed simply by changing the shape of 1a. Further, according to such a parting line PL1, burrs that may be generated at the boundary between the back side surface 3b of the blade 3 and the front edge surface 3c are aligned with the direction (the direction of extension of the blade 3) of the back side surface 3b of the blade 3. (In the width direction), it is possible to further reduce the wind resistance due to the burr when the fan 1 rotates.

On the other hand, it is parallel to the reference axis 5,
Trailing edge 3 of each blade 3 without radial undercut
d can be appropriately formed by one or both of the adjacent slide molds 13. Specifically, the slide mold 13 is moved in the radial direction W along the back surface 3b of the blade 3 (the blade 3 on the side forming the back surface 3b).
In the present embodiment, which is slid in the radial direction W along the reference axis 5 of FIG. 1, as shown in FIG. The rear surface 1 of the slide mold 13 continuously with the back surface 3b
3b, the remaining partial area is formed continuously with the front side surface 3a by the front surface 13a of the adjacent slide mold 13. That is, the parting line PL3 between the adjacent slide molds 13 is
Is set at the portion of the rear edge surface 3d that swells most in the anti-rotation direction of the fan. In addition, this parting line
The PL3 can be set at any other location in consideration of the manufacturability of the slide mold 13 and the like. However, when the slide mold 13 is slid in the radial direction W that is not parallel to the reference axis 5, It is necessary to set the parting line PL3 at, for example, the most protruding portion on the trailing edge 3d in the fan rotation axis direction (discharge side direction).

Also, since the radius of the top surface 3e in the range on the outer periphery of the boss portion 2 of each blade 3 is swelled in the radial direction, one of the adjacent slide dies 13 is formed. Alternatively, it can be appropriately formed by both. Here, both are formed in half and half (FIG. 3).

The edge portion around the blade 3 preferably has a round shape in order to eliminate stress concentration and maintain good strength.
This is also true for reducing wind resistance (drag) and preventing turbulence. The most common and preferable shape of such a round shape is a substantially semicircular round shape whose diameter is the thickness of the plate-shaped blade 3 protruding in the direction of extension from the edge thereof. is there.

However, in the present embodiment in which the parting line PL1 is set along the back side surface 3b of the blade 3 and the front edge surface 3c is formed by the engraved surface 11a of the fixed mold 11, the front edge is The radius of the surface 3c cannot be semicircular. Since the blade 3 is inclined with respect to the axis of rotation of the fan, if the radius of the front edge surface 3c is a semicircular shape that bulges in the direction in which the blade 3 extends (the width direction), the blade 3 projects most in the direction of fan rotation. This is because a portion to be formed is an intermediate portion of the front edge surface 3c, and a portion thereof is undercut in the mold opening / closing direction Z. Therefore, in the present embodiment, the round shape of the front edge surface 3c includes an arc whose boundary portion with the back side surface 3b protrudes most in the fan rotation direction as shown in FIGS. It is formed in a curved shape. That is, in the figure, the center of the arc is on the line in the rotational direction from the boundary point with the back side surface 3b, or the trailing edge side of the blade 3 (discharge side, (Lower). Note that there is no such restriction on the trailing edge surface 3d and the top edge surface 3e, so that the round shape is formed in a substantially semicircular shape.

The slide mold 13 is fixed to the fixed mold 1.
Although it can be supported on either side of the movable mold 1 and the movable mold 12, and can be supported independently of these,
Generally, it can be supported movably in the radial direction W with respect to the movable mold 12. Also, the slide mold 13
An appropriate actuator such as a hydraulic actuator can be used as an actuating means for moving in a radial direction W between the mold clamping position and the mold opening position, or by using a diagonal guide pin, a link device, or the like. It is also possible to move the fixed mold 11 and the movable mold 12 in the radial direction W in accordance with the relative movement in the mold opening / closing direction Z. In addition, in this embodiment, the radiation direction W is set to the radiation direction W parallel to the back side surface 3b of each blade 3, but even in the radiation direction W parallel to the front side surface 3a, or The intermediate radiation direction W may be used (however, the parting line PL3 needs to be appropriately set accordingly).

At the time of injection molding, after the mold is clamped in the state shown in FIGS. 2 and 3, a hot-melt synthetic resin material is injected into a cavity 14 (14a, 14b) from a gate (not shown). After the material has cooled and solidified,
The fixed mold 11 and the movable mold 12 are relatively separated from each other, and the slide mold 13 is moved outward in the radial direction W to open the mold, thereby taking out the molded resin product. Thus, it is possible to obtain the overlap fan 1 integrally formed from the synthetic resin material.

As described above, the injection mold apparatus 10 according to the present embodiment has the forward blade type overlap fan 1, ie,
The boss 2 and the outer peripheral surface of the boss 2 are radially and
A plurality of blades 3 projecting obliquely with respect to the rotational direction, and in particular, having a tip portion formed as a forward wing that is widened forward (leading edge side) in the rotational direction; Each of the blades 3 is a mold device for molding an overlap fan 1 partially overlapped with the adjacent blade 3 in the rotational axis direction by injection molding of a synthetic resin material. A pair of dies that can be opened and closed with each other, that is, each of the fixed dies 11 and the movable dies 12 is disposed between the adjacent blades 3, and is formed into a shape in which the dies are closed to each other at the time of mold clamping. A slide mold 13 movable in the radial direction W;
The cavity 14a corresponding to the boss portion 2 is formed between the fixed-side mold 11 and the movable-side mold 12, and
The cavities 14b corresponding to the respective blades 3 include the slide dies 13, 13 adjacent to each other and the engraving surface 1 of the fixed-side dies 11 formed corresponding to the front edge surface 3c of the blade 3.
1a.

More specifically, the fixed mold 1
The first engraving surface 11a includes a front side surface 3a and a top edge surface 3e of a front edge side portion expanded in the rotation direction front side, in addition to the front edge surface 3c which is undercut in the radial direction W. It is formed corresponding to the surface of the blade 3. The front edge surface 3c has a round shape, but the mold opening / closing direction Z
On the other hand, the rear side surface 3b of the blade 3 is formed by the surface (front surface 13a) of the slide die 13 including the expanded front edge side portion, so that each slide die 13 is formed. And fixed mold 11
The radial parting line (mating surface) PL with
A parting line PL1 is formed along the back side surface 3b bordering the front edge surface 3c.

For this reason, according to the injection molding die apparatus 10, the slide die 13 movable in the radial direction W is provided, and the blade 3 is moved between the slide die 13 adjacent to each other.
Is formed, the synthetic resin overlap fan 1 in which the blades 3 are partially overlapped (overlapping) in the rotation axis direction can be formed as a single molded body. . In addition, since the leading edge surface 3c of the blade 3 is formed by the engraving surface 11a of the fixed mold 11, the blade 3 is formed as a forward wing, and the tip side portion is formed to bulge forward in the rotation direction. Despite this, the forward wing-type overlap fan 1 can be easily formed.

Further, in the present embodiment, the side surface (front surface 13a) forming the back surface 3b of the blade 3 in each slide mold 13 is such that the back surface 3b is closest to the front edge direction in the fixed mold 11 side. Beyond the protruding part, it is further extended in a shape corresponding to the back side surface 3b. That is, the above parting line PL1 is
b, and is further extended beyond the maximum protruding portion of the rear side surface 3b. For this reason, various forward blade-type overlap fans 1 having different wing-spreading lengths in the leading edge direction (forward in the rotation direction) can be used to form the engraving surface of the fixed-side mold 11 without changing the slide mold 13. By simply changing the shape of 11a, molding can be easily performed, and the manufacturing cost of the mold can be reduced correspondingly.

In the above embodiment, the front edge of the front side 3a (and the top edge 3e) of each blade 3 is formed by the engraved surface 11a of the fixed die 11, and The rear surface 13b of the mold 13 (blade 3
The parting line PL2 between the front side surface 3a and the fixed mold 11 is moved from the base of the front edge surface 3c (the boundary on the edge of the boss 2 on the front side surface 3a) to open and close the mold. The front side surface 3a is set parallel to the reference axis 5 like the back side surface 3b.
Since there is no undercut in the radiation direction W, the parting line PL2 can be set at an arbitrary position on the front side 3a, and like the parting line PL1, along the front side 3a. It can also be formed.
Which mode to use can be appropriately determined from the viewpoint of ease of manufacturing a mold and the like.

Further, in the above embodiment, the suction side (the leading edge side of the blade 3) of the overlap fan 1 is on the side of the fixed mold 11, and the discharge side (the rear edge side of the blade 3) is the movable side mold. Although they are respectively associated with the mold 12 sides, this relationship can be reversed. That is, the fixed mold 11 and the movable mold 12 which can be opened and closed in the mold opening and closing direction Z mutually.
On the other hand, which side in the rotation axis direction of the overlap fan 1 corresponds to the fixed mold 11 or the movable mold 12 depends on, for example, the specific shape of the boss 2 or the like. Can be determined appropriately. In the above embodiment, when the suction side of the overlap fan 1 is directed toward the movable mold 12, the engraved surface 11 a is formed on the movable mold 12.

Further, in the above embodiment, the overlap fan 1 to be formed or formed has the blade 3 formed as a forward wing, and the overlapping fan 3 is formed by radiating to form the overlapped blade 3. Direction W
The above-mentioned embodiment is provided with a slide mold 13 which is movable in a predetermined direction, and in which a surface portion which becomes an undercut in the radial direction W is formed by the engraved surface 11a of the fixed mold 11 (or the movable mold 12). Mold device 10 in the form of
A blade composed of a trailing wing whose front end portion on the trailing edge side is expanded in the opposite rotation direction, or a blade whose front end portions on the leading edge side and the trailing edge side are both expanded (deformation of the forward wing);
Further, other variable-width blades in which at least one of the leading edge side and the trailing edge side is partially widened, and in some cases, a blade having a shape such that the leading edge surface or the trailing edge surface does not become undercut, etc. The present invention can be appropriately modified and applied to an overlap fan having blades of various special shapes.

Such a modified example will be specifically described below.

FIG. 8 is a virtual development plan view showing another form of an overlap fan having a different shape of the front edge side portion of the blade. FIG. 9 is a virtual exploded sectional view of an injection mold apparatus according to another embodiment of the present invention for injection-forming the overlap fan. Note that FIGS. 8 and 9
Each of them is represented by the same method as in FIG. 7 (virtual development plan view of the fan) and FIG. 1 (virtual development cross-sectional view of the injection molding die apparatus), and only different main parts are shown. The same or corresponding parts as those in the above embodiment include:
The same reference numerals are used.

As shown in FIG. 8, the blade 3 'of this embodiment is formed as a forward wing similarly to the above-mentioned blade 3 and has a portion (a front side portion) from a substantially center to a front end in a radial direction on a front edge side. 3s) is expanded so as to be wider in the rotation direction side, and the expanded tip portion 3
s, the root side 3n on the leading edge side is inside (discharge side)
It is formed in a twisted shape. In other words, the tip portion 3s of the blade 3 'has the same shape as the blade 3 described above, but the root portion 3n on the leading edge side has an inclination angle (mounting angle) with respect to the rotation direction which is smaller than that of the tip portion 3s. It is twisted from the middle to make it smaller.
In addition, the front side surface 3a and the back side surface 3 at the root side portion 3n.
b and the leading edge surface 3c are substantially parallel to the reference axis 5 similarly to the leading edge portion 3s (however, the leading edge surface 3c of the leading edge portion 3s that gradually widens toward the tip side). Are inclined with respect to the reference axis 5), and other portions are the same as those of the blade 3.

The blade 3 'is
The protruding portion is provided on the outer periphery of the boss portion 2 so that the tip side portion is more inclined with respect to the rotation direction than in the case of (1). Therefore, according to the overlap fan 1 'provided with such a blade 3', the front end portion 3 which is also wide is provided.
By increasing the mounting angle of s, the lift coefficient can be increased and more air volume can be obtained. On the other hand, the mounting angle is reduced and the lift coefficient is reduced at the root portion 3n where eddy currents that cause noise are likely to be generated. Since it is small, the eddy current can be further suppressed and noise can be further reduced.

As shown in FIG. 9, an injection mold apparatus 10 'for injection-molding the overlap fan 1' provided with such a blade 3 'is the same as that shown in FIGS. Is basically the same as that of the injection molding die apparatus 10 in the form, but in order to form the cavity 14b corresponding to the shape of the blade 3 ', the die-sinking surface 1 of the fixed side die 11 is formed.
1a and the shape of the surface of the slide mold 13 cooperating therewith are changed.

That is, the engraving surface 11a of the fixed mold 11
Are screwed with respect to the front edge 3c of the blade 3 'and the front edge of the front side 3a, ie, the front side 3s of the front side 3a, which are undercut in the radial direction W parallel to the reference axis 5. It is formed so as to correspond to the range portion of the root side portion 3n. Therefore, the rear surface 1 of the slide mold 13
Parting line PL2 between 3b and fixed mold 11 is:
It is set in the mold opening / closing direction Z from the twisting base point of the root side portion 3n on the front side surface 3a of the blade 3 '. The top surface 3e on the leading edge side of the blade 3 'is formed on the engraved surface 11a, and if necessary, the lower edge surface of the root side portion 3n protruding from the edge of the boss portion 2 is also formed. It is formed. On the other hand, the front surface 13 of the slide mold 13
a is a shape corresponding to the back side surface 3b of the blade 3 ', that is, a shape which is curved slightly convexly along the tip side portion 3s as a whole, but is a torsionally bent root portion on the leading edge side. 3n is formed in a concave shape along the back side surface 3b.

However, more specifically, since the leading edge surface 3c of the root side portion 3n of the blade 3 'is parallel to the reference axis 5, the radius of the leading edge surface 3c is the most common here. The shape is a semi-circular shape. Therefore, the parting line PL1 between the front surface 13a of the slide mold 13 and the fixed mold 11 is located at the root 3n of the blade 3 'at the portion of the semicircular front edge 3c which protrudes most in the fan rotation direction. Is set to That is, of the front edge surface 3c of the root side portion 3n, a portion extending from the edge of the back side surface 3b, which is undercut in the mold opening / closing direction Z, to the portion most protruding in the fan rotation direction, is the slide mold 13c.
Is formed by the front surface 13a of the main body.

As described above, even with the blade 3 'formed as a forward wing, a part of the leading edge surface 3c which does not undercut in the radial direction W parallel to the reference axis 5 is formed in a semicircular round shape. can do. The parting line PL1 at the tip side 3s of the blade 3 'is set on the back side 3b bordering the front edge 3c, as in the case of the blade 3 of the above-described embodiment. Is provided in a shape corresponding to the rear side surface 3b beyond the portion most protruding in the rotation direction and further extended. Therefore, various blades 3 'having different wing-spread lengths of the tip-side portion 3s can be easily formed by changing the surface shape of the engraving surface 11a of the fixed-side mold 11 without changing the slide mold 13. Can be formed.

[0054]

As described above, according to the first aspect of the present invention, there is provided an injection molding apparatus for an overlap fan, wherein the boss portion and the outer peripheral surface of the boss portion are radially inclined with respect to the rotation direction. A plurality of blades having a shape in which at least one edge of the leading edge side and the trailing edge side is partially expanded, and each of those blades has a part with an adjacent blade. In a mold apparatus for molding an overlap fan made of a synthetic resin arranged in an overlapping manner in a rotation axis direction by injection molding, a fixed mold and a movable mold that are openable and closable in a mold opening and closing direction are adjacent to each other. A sliding mold that is arranged between the blades and that is movable in the radial direction and that is formed in a shape that closely contacts each other in an annular shape when the mold is clamped, and a boss portion is formed by the fixed mold and the movable mold. Corresponding to And forming the cavities corresponding to the blades into a slide mold adjacent to each other and a fixed mold or a movable mold corresponding to a portion including an edge surface on the side where the blade is expanded. It is formed between the formed engraving surface.

Therefore, in the injection molding die apparatus of the overlap fan, especially, it is disposed between the adjacent blades and is movable in the radial direction formed into a shape which is annularly close to each other when the mold is clamped. Since each blade is formed by these slide dies adjacent to each other, the overlap fans in which the blades are overlapped and arranged in the rotation axis direction are made of a single synthetic resin. The blade can be formed as a molded body, and the portion including the edge surface on the expanded side of the blade that is undercut in the radial direction is formed by the engraving surface of the fixed mold or the movable mold. Therefore, even if the blade has a partially expanded shape such as a forward wing, it can be easily formed. That is,
According to this mold apparatus, in order to obtain a high air flow, a single overlapping fan in which a number of partially expanded blades such as a forward wing are arranged in an overlapping manner in the rotation axis direction is provided. There is an effect that it can be molded as a synthetic resin molded article.

According to a second aspect of the present invention, there is provided an injection mold apparatus for an overlap fan according to the first aspect, wherein each slide die and the fixed side die or the movable side die having the engraved surface are formed. The parting line is set so as to extend further along the side surface of the blade bordering the above-mentioned edge surface, beyond the portion where the side surface protrudes most in the rotation direction.

Therefore, according to the injection mold device for the overlap fan, the slide mold is not changed, but only the shape of the engraving surface of the fixed mold or the movable mold is changed. Thus, there is an effect that various overlap fans having different wing-spread lengths can be easily formed at a lower die manufacturing cost.

[Brief description of the drawings]

FIG. 1 is a virtual development cross-sectional view showing a virtual development of a main part of an injection mold apparatus for an overlap fan according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view (longitudinal cross-sectional view) of a main part, taken along line AA of FIG. 1 (die opening / closing direction).

FIG. 3 is a cross-sectional view (transverse cross-sectional view) of a main part, which is cut along a line BB (a direction perpendicular to the mold opening / closing direction) of FIG.
It is.

FIG. 4 is a perspective view showing an entire overlap fan molded by the injection molding die apparatus according to one embodiment of the present invention.

FIG. 5 is a plan view showing the overlap fan of FIG. 4 as viewed from a suction side.

FIG. 6 is a cross-sectional view of the overlap fan of FIG. 4 cut along a plane including a rotation axis.

FIG. 7 is a virtual development plan view showing the overlap fan of FIG. 4 virtually developed and viewed from the outer peripheral side.

FIG. 8 is a virtual development plan view showing an overlap fan having a blade shape according to another embodiment, which is virtually developed and viewed from the outer peripheral side.

9 is a virtual development cross-sectional view showing a virtual development of a main part of an injection molding die apparatus according to another embodiment of the present invention for molding the overlap fan of FIG. 8;

[Explanation of symbols]

 1, 1 'Overlap fan 2 Boss part 3, 3' Blade 10, 10 'Injection molding die apparatus 11 Fixed die 11a Die surface 12 Moving die 13 Slide die 14 Cavity 14a Cavity (boss part) ) 14b Cavity (blade)

Claims (2)

[Claims] 1. A boss portion and a projection protruding radially on the outer peripheral surface of the boss portion and inclined with respect to the rotation direction, and at least one edge of a front edge side and a rear edge side is partially enlarged. A plurality of blades each having a winged shape, wherein each of the blades is formed by injection molding a synthetic resin overlap fan in which a part of the blade overlaps an adjacent blade in the rotation axis direction. In the mold apparatus, a fixed mold and a movable mold that can be opened and closed in the mold opening and closing direction are disposed between the adjacent blades, and are formed into shapes that are in annular contact with each other when the mold is clamped. A sliding mold movable in a radial direction, wherein the fixed mold and the movable mold form a cavity corresponding to the boss, and a cavity corresponding to each blade is Formed between the adjacent slide mold and the engraving surface formed on the fixed mold or the movable mold corresponding to a portion including the edge surface on the blade-expanded side of the blade. A mold apparatus for injection molding of an overlap fan. 2. A parting line between each of the slide molds and the fixed mold or the movable mold on which the engraving surface is formed is provided on a side surface of the blade which is in contact with the edge surface. The mold device for injection molding of an overlap fan according to claim 1, wherein the side surface is further set to extend further beyond a portion most protruding in the rotation direction.