JP2004322445A - Mold for molding centrifugal multi-blade fan - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold which can simply form a noise preventing slit in a foil and improve the production efficiency of a centrifugal multi-blade fan. <P>SOLUTION: The mold is composed of a lower mold 110 having a foil outside forming channel 114, an upper mold 120 having a foil inside forming channel 121 having a side wall with slit forming projections 125A and 125B erected, and a trimming mold 130 having a trimming piece 131 in the shape of a slender plate inserted into the channel 121 from above the upper mold 120. After the molding of a resin material, the trimming mold and the lower mold are extracted from the upper mold. By slightly turning the centrifugal multi-blade fan 100 in relation to the upper mold, the molding of the fan 100 can be extracted easily from the upper mold. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a mold for a centrifugal multi-blade fan constituting a blower of an air conditioner used for an automobile or the like.
[0002]
[Prior art]
Generally, an automotive air conditioner includes a centrifugal multi-blade fan that is driven to rotate by an electric motor at an upstream end of a duct. During operation of the automotive air conditioner, the centrifugal multi-blade fan is rotated to inhale air from the interior of the automobile or from outside the automobile, and send the air into the duct. The air sent into the duct in this manner is adjusted to a desired temperature by passing through an evaporator, a heater core, and the like provided in the duct, and then, from an outlet provided at the downstream end of the duct, It blows out into the car interior.
[0003]
As a centrifugal multi-blade fan to be incorporated in such an air conditioner for a vehicle, a centrifugal multi-blade fan in which a slit is formed in a longitudinal direction to reduce noise is known (for example, see Patent Document 1). It is known that a centrifugal multi-blade fan including a blade plate having such a slit secures a large airflow and reduces airflow noise generated during operation. In the case of manufacturing such a centrifugal multi-blade fan, there is a method in which components such as a wing plate and a bottom plate are separately manufactured, and these are assembled and integrated. Is preferred.
[0004]
More specifically, as shown in FIG. 7, the centrifugal multi-blade fan 10 has a circular bottom plate 1 having a circular boss 1 </ b> A formed in the center (upward in the figure) and a bottom plate 1. It is composed of a large number (for example, about 40) of wing plates 2 erected at equal intervals on the peripheral edge, and a ring-shaped rim plate 3 on which the upper portions of the wing plates 2 are fixed. Slits 4 </ b> A and 4 </ b> B are formed in a portion on the inner diameter side of each blade 2 in the vertical direction.
[0005]
Then, as a manufacturing method for integrally molding the centrifugal multi-blade fan 10 having such a structure, an upper die (not shown), a lower die, and the upper plate (see FIG. A sword-shaped upper punching die provided with a large number of blade-like plate portions 5 to be inserted to the position of the intermediate portion and forming a slit 4A, and a middle portion of the blade plate 2 from below the lower die. A sword-shaped lower punching die provided with a number of blade-like plate portions 6 for inserting the punching marks to form the slits 4B and setting the same, and injecting synthetic resin into the cavity to perform injection molding. Done. As shown in FIG. 7, a support portion 7 is formed on the upper portion of the slit 4A so as to straddle and connect the blades 2 in front and behind the slit 4A. Since the support portion 7 is shaped to straddle the slit 4A, the blade-shaped plate portion 5 of the upper punching die can be removed. On the other hand, an opening 8 is formed in each part of the bottom plate 1 where the lower end of the slit 4B is located so as to pass through the blade-shaped plate part 6 of the lower punching die downward.
[0006]
[Patent Document 1]
JP-A-10-306796, page 9, FIG.
[0007]
[Problems to be solved by the invention]
However, in the above-described conventional method for manufacturing a centrifugal multi-blade fan, since the blade-shaped plate portions 5 and 6 for forming the slits 4A and 4B are elongated punching dies ranging from 4 cm to 8 cm, the slits 4A and 4B are formed. There is a problem that the accuracy and life of the mold are reduced as compared with the mold of the centrifugal multi-blade fan which does not have the mold.
[0008]
Specifically, in the above-described conventional centrifugal multi-blade fan, the positioning accuracy of the blade-shaped plate portions 5 and 6 corresponding to the upper and lower punching dies and the accuracy error due to the bending of the blade-shaped plate portions 5 and 6 are different. And so on.
[0009]
In addition, since the number of the blade-shaped plate portions 5 and 6 is large (around 40), and in addition, the drawing stroke in the vertical direction is long, the blade-shaped plate portions 5 and 6 need to be formed of a material having high rigidity and being hardly deformed. . However, no matter how high the rigidity of the material, the material is difficult to be deformed. When the material is applied to an elongated material such as the blade-shaped plate portions 5 and 6, breakage or bending cannot be avoided.
[0010]
Therefore, an object of the present invention is to provide a highly durable molding die that can easily form a slit for preventing noise in a blade plate and enhances the manufacturing efficiency of a centrifugal multi-blade fan.
[0011]
[Means for Solving the Problems]
According to the first aspect of the present invention, a large number of blades are spaced from each other along the circumferential direction on a peripheral portion on one surface side of the bottom plate having a rotating body shape so as to be parallel to the rotation axis of the bottom plate. A centrifugal centrifuge in which an air flow path is interposed between the blades, and a slit is formed in a radially inner portion of the blade in the bottom plate in a direction parallel to the rotation axis. A molding die for a multi-blade fan, having a container shape, a bottom plate lower surface forming portion for forming the bottom plate lower surface being formed in an inner bottom portion, and forming the radially outer portion of the blade plate. A lower mold in which a blade plate outer forming groove is formed on an inner peripheral surface; and a cylindrical container shape fitted inside the lower mold, wherein the blade plate outer forming groove formed in the lower mold. When formed on the outer peripheral surface to correspond to A wing plate inner side forming groove having a groove width dimension longer than twice the thickness of the wing plate, and a slit forming projection for forming the slit formed on one of the side walls. A die, and a punching die having an elongated plate-like punched piece inserted into the blade plate inner side forming groove from above the upper die.
[0012]
According to the first aspect of the present invention, the upper metal mold is housed in the lower metal mold, and the resin material is formed into the molding metal with the cut piece of the metal mold inserted from above into the groove formed inside the blade plate of the upper metal mold. A centrifugal multi-blade fan can be formed in a mold. After forming the centrifugal multi-blade fan, the punching die is pulled out above the upper die, the lower die is pulled out relatively downward with respect to the upper die, and the blades are pulled out in the width direction of the blade plate inner forming groove 121. By moving the plate (rotating the centrifugal multi-blade fan with respect to the upper mold), the wing plate can be extracted from the projection for forming the slit, and the centrifugal multi-blade fan can be extracted below the upper mold. It becomes. In this way, by forming a slit in the blade, the inflow wind flowing into the pressure surface side of the adjacent blade supplies momentum to the inflow wind separated and flown in at the radially innermost end of the blade. Then, the momentum of the inflow wind of the adjacent blade is recovered. As a result, the inflow loss can be reduced, the drift between the blade plates can be made uniform, and the noise due to the separation vortex can be reduced.
[0013]
The invention according to claim 2 is the molding die of the centrifugal multi-blade fan according to claim 1, wherein at least one of the side walls on both sides of the blade-side inner-side forming groove at least on the rotational drive side of the centrifugal multi-blade fan. The side wall is curved so as to bulge toward the opposite side to the rotation driving direction, and the slit forming protrusion is formed on the side wall on the rotation driving direction side by the same dimension as the thickness dimension of the wing plate. It is characterized by being provided so as to protrude.
[0014]
According to the second aspect of the present invention, by moving the blade in the bending direction, the blade can be easily removed from the slit-forming projection of the groove formed inside the blade.
[0015]
The invention according to claim 3 is the molding die for a centrifugal multi-blade fan according to claim 2, wherein the slit-forming projection has a trapezoidal cross-section that is gradually narrowed toward the tip. Features.
[0016]
According to the third aspect of the present invention, since the width of the protrusion for forming a slit is gradually reduced toward the tip, the blade plate can be further easily removed from the protrusion for forming a slit. For this reason, the slit of the formed wing plate is wider on the surface (concave surface) opposite to the bending direction and narrower on the bending direction side, so that the wind passing through the slit can easily flow obliquely outward in the rotation direction, and is adjacent to the slit. This inflow wind flowing into the pressure surface side of the vane plate supplies momentum to the inflow wind separated and inflow at the innermost end in the radial direction of the vane plate, and recovers the momentum of the inflow wind of the adjacent vane plate. . As a result, it is possible to reduce the inflow loss and at the same time uniformize the drift between the blade plates, and to improve the effect of reducing the noise due to the separation vortex.
[0017]
【The invention's effect】
According to the first aspect of the invention, a centrifugal multi-blade fan with a slit can be easily manufactured with a simple structure, and the durability of a molding die can be increased.
[0018]
According to the second aspect of the present invention, at least the side wall on the rotation drive direction side of the centrifugal multi-blade fan among the side walls on both sides of the blade plate inner formation groove swells toward the opposite side to the rotation drive direction. With such a curved shape, the blade can be easily peeled off so that the slit-forming projection comes out of the slit, and damage to the blade at the time of mold release can be prevented.
[0019]
According to the third aspect of the present invention, in addition to the effect of the second aspect, it is possible to further easily extract the slit forming projection from the slit of the blade.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, details of a molding die of a centrifugal multi-blade fan according to the present invention will be described based on an embodiment shown in the drawings. In the present embodiment, the present invention is applied to a centrifugal multi-blade fan used as a blower of an automotive air conditioner. Prior to the description of the mold for the centrifugal multi-blade fan according to the present embodiment, the configuration of the centrifugal multi-blade fan manufactured using the mold will be described. In the description of the embodiments, the rotation axis direction of the centrifugal multi-blade fan will be described as the vertical direction for convenience, but the arrangement of the centrifugal multi-blade fan is not limited to this.
[0021]
[Configuration of centrifugal multi-blade fan]
FIG. 1 is a perspective view of a centrifugal multi-blade fan manufactured by a molding die according to the present embodiment, and FIG. 2 is a cross-sectional view showing a state where a blade plate of the centrifugal multi-blade fan is cut along a plane orthogonal to a rotation axis. . As shown in FIG. 1, the centrifugal multi-blade fan 100 has a bottom plate 101, a large number of (for example, about 40) blade plates 102, and a rim plate 103 integrally formed of a resin material.
[0022]
At the center of the bottom plate 101, a boss 104 bulging upward in a substantially conical shape is formed. The back surface side of the boss 104 is a substantially mortar-shaped recess, and a motor for rotational driving is arranged in the recess.
[0023]
The wing plate 102 is erected on the peripheral portion of the bottom plate 101 at predetermined intervals along the circumferential direction. These blades 102 are formed so that the center in the width direction is curved and swells in the direction opposite to the rotational driving direction indicated by arrow a in FIG. Slits 105 </ b> A and 105 </ b> B are formed along the longitudinal direction (rotational axis direction) at the radially inner portion of each blade 102. The slits 105A and 105B are separated from each other, and the upper end of the slit 105A is formed so as not to reach the upper edge of the blade 102, and the lower end of the slit 105B is It is formed so as not to reach the lower edge.
[0024]
As shown in FIG. 2, these slits 105A and 105B have tapered surfaces 106 on both side walls in the radial direction so as to gradually become narrower in a direction substantially opposite to the rotational driving direction a of the blade 102. 107.
[0025]
The rim plate 103 is a ring-shaped plate provided so as to connect the upper ends of the many blades 102 and is integrated with these blades 102.
[0026]
The configuration of the centrifugal multi-blade fan 100 has been described above. However, by using the tapered surfaces 106 and 107 as described above, a work (molded product) can be easily taken out from a molding die described later.
[0027]
Further, by forming the slits 105A and 105B in such a structure, the following operations and effects can be obtained. That is, as shown in FIG. 3, the inflow air A1 taken in from the center of the centrifugal multi-blade fan 100 flows into the pressure surface 102A, which is the front surface in the rotational drive direction a of the blade 102, in a deflected manner, and flows in. Part of the wind A1 flows through the slit 105A (105B) to the low-pressure suction surface 102B side, and the inflow wind A2 flowing to the pressure surface 102A side of the adjacent vane 102 is the innermost in the radial direction of the vane 102. The momentum is supplied to the inflow wind A2 separated and flown in at the end to recover the momentum of the inflow wind A2. As a result, the inflow loss can be reduced, the drift between the blade plates 102 can be made uniform, and the noise due to the separation vortex can be reduced. In order to cause a part of the inflow from the slits 105A and 105B to flow into the inflow from the adjacent vane plate 102 to obtain the momentum injection effect, the amount of the inflow should be set to an appropriate amount as compared with the inflow main flow. If the amount is large, a leakage loss occurs.
[0028]
[Molding mold for centrifugal multi-blade fan]
As shown in FIG. 4, the molding die according to the present embodiment generally includes a lower die 110, an upper die 120, and a punching die 130.
[0029]
First, the structure of the lower mold 110 will be described. As shown in FIG. 4, the lower mold 110 has a cylindrical container shape, and a bottom plate lower surface forming portion 111 for forming the lower surface side of the bottom plate 101 of the centrifugal multi-blade fan 100 described above is formed on the inner bottom. I have. A substantially conical projection 112 for forming the boss 104 of the centrifugal multiblade fan 100 is formed at the center of the bottom plate lower surface forming portion 111. Further, in the peripheral portion of the bottom plate lower surface forming portion 111, a blade lower end portion forming groove 113 for forming a portion of the blade plate 102 projecting below the bottom plate 101 is formed. Further, on the inner peripheral surface of the lower mold 110, the blade outer side forming groove 114 for continuously rising from the outer end of the blade lower end forming groove 113 to form a radially outer portion of the blade 102. Is formed.
[0030]
In addition, a shaft insertion hole forming protrusion 115 for forming an insertion hole for inserting a shaft of the driving motor is formed at the top of the protrusion 112. The end surface around the opening at the upper end of the lower mold 110 is a rim plate lower surface forming portion 116 for forming the lower surface of the rim plate 103 of the centrifugal multi-blade fan 100 described above.
[0031]
Next, the upper mold 120 will be described with reference to FIG. Note that the upper mold 120 shown in FIG. 4 shows a partially broken state for convenience of explanation. The upper mold 120 is a substantially cylindrical container having a diameter dimension that is closely fitted inside the lower mold 110 described above. On the lower surface of the upper mold 120, a bottom plate upper surface forming portion (not shown) for forming the upper surface of the bottom plate 101 of the centrifugal multi-blade fan 100 is formed.
[0032]
Further, on the outer peripheral surface of the upper die 120, a blade plate inner forming groove 121 for forming a radially inner portion of the blade plate 102 of the centrifugal multi-blade fan 100 is formed. The groove width of the blade-side inner forming groove 121 is set to be relatively long within a range that is at least twice as large as the thickness of the blade 102 and does not reach the adjacent blade-side inner forming groove 121. . One of the side walls 124 (the side wall facing the inside of the curved surface of the wing plate 102) of the opposing side walls forming the wing plate inside forming groove 121 is provided with slit forming projections 125A along the rotation axis direction. 125B protrudes toward the other side wall. The protrusion dimensions of the slit forming projections 125A and 125B are set to be the same as the dimensions of the centrifugal multi-blade fan 100 that penetrate the slits 105A and 105B, that is, the thickness of the blade 102. A cut-out piece 131 of a punching die 130 to be described later is inserted into the blade plate inner side forming groove 121.
[0033]
Further, a rim plate upper surface forming portion 122 is formed on the periphery of the upper end portion of the upper mold 120 so as to protrude outward and rotate. In addition, the above-described wing plate inner side forming groove 121 is exposed at an upper end portion inside the rim plate upper surface forming portion 122 so that a cut piece 131 of a cutting die 130 described later can be inserted. A ring storage groove 123 in which the support ring 132 is stored is formed around the circumference.
[0034]
Next, the configuration of the punching die 130 will be described. As shown in FIG. 4, the punching mold 130 is configured such that the same number of punching pieces 131 as the above-mentioned wing plate inner forming grooves 121 hang down at predetermined intervals along the circumferential direction on the lower surface of the annular support ring 132. Is provided. These cut pieces 131 are formed so as to form an inner portion of the wing plate 102 of the multi-blade fan 100 together with the upper mold 120 in a state of being inserted into the wing plate inside forming groove 121. It should be noted that the cut piece 131 is formed much thicker than the blade 102. This is because the interval between the wing plates 102 is longer than the thickness dimension of the wing plate 102, so that the blank 131 can be made thicker.
[0035]
The centrifugal multi-blade fan 100 as shown in FIG. 1 is formed by combining the lower mold 110, the upper mold 120, and the punching mold 130 and injecting a resin material into the cavity as described above. . Although FIG. 4 does not show a portion where a resin such as a gate is injected into a molding die, a resin injection portion such as a gate is formed so as to communicate with a cavity forming the centrifugal multi-blade fan 100. Needless to say.
[0036]
[Production method of centrifugal multi-blade fan]
Next, a method for manufacturing the centrifugal multi-blade fan 100 using the molding die according to the present embodiment will be described. FIG. 5 is a cross-sectional view taken along the line AA of FIG. 4 in a state where the molding dies are assembled. FIG. 6 is a diagram in which the lower mold 110 and the punching mold 130 are removed from the upper mold 120 after molding. It is sectional drawing which shows the state which removes the molded product of the wing fan 100.
[0037]
First, the above-described lower mold 110, upper mold 120, and punching mold 130 are combined as shown in FIGS. At this time, as shown in FIG. 5, the strip 131 of the punching die 130 is arranged so as to be in close contact with the side wall of the upper die 120 located on the side opposite to the bending direction in the blade-side inner forming groove 121. For this reason, a void for forming the radially inner portion of the blade 102 having the slits 105A and 105B can be formed by the cutout piece 131 and the blade inner forming groove 121. As shown in FIG. 5, this gap is positioned between the upper and lower dies 110 and 120 and the punching die 130 so as to be aligned with and communicate with the wing plate outside forming groove 114 of the lower die 110. It has become so.
[0038]
Next, after assembling a mold as shown in FIG. 5, a resin material is injected into the cavity to form the centrifugal multi-blade fan 100. After that, the punching die 130 and the lower die 110 are moved from the upper die 120 in the direction of the rotation axis and removed. At this time, the centrifugal multi-blade fan 100 remains in the upper mold 120. Next, by rotating the centrifugal multi-blade fan 100 in the direction opposite to the rotational drive direction, the slit forming projections 125A and 125B are disengaged from the slits 105A and 105B of the wing plate 102 of the centrifugal multi-blade fan 100. Can be extracted below the upper mold 120. By removing the centrifugal multi-blade fan 100 from the upper mold 120 in this way, the manufacture of the centrifugal multi-blade fan is completed.
[0039]
In the molding die according to the present embodiment described above, when the centrifugal multi-blade fan 100 is die-cut, the centrifugal multi-blade fan 100 can be easily removed without being caught by the upper die 120 only by rotating the centrifugal multi-blade fan 100. As a result, the slits 105A and 105B can be formed with high precision. Further, in this molding die, since the centrifugal multi-blade fan 100 is rotated and peeled off, one of the side walls 124 (the curved inner side of the blade plate 102) of the opposing side walls forming the blade plate inner formation groove 121 is formed. The projections 125A and 125B for forming the slits need only be provided on the side wall facing the other) along the direction of the rotation axis so as to project toward the other side wall, so that the mold structure can be simplified. Further, since the portion between the slits 105A and 105B of the blade 102 of the centrifugal multi-blade fan 100 extracted from the upper die 120 is flush with the blade 102, design accuracy and design strength can be easily realized.
[0040]
Although the embodiment has been described above, the present invention is not limited to this, and various design changes accompanying the gist of the configuration are possible.
[0041]
For example, in the above-described embodiment, as shown in FIG. 2, the sidewalls on both sides of the slits 105A and 105B formed in the blade 102 are tapered surfaces 106 and 107, but may be curved surfaces having a substantially tapered shape. Good. In this case, the slit-forming projections 125A and 125B may have a projection shape corresponding to their curved surfaces.
[0042]
Further, although the above-mentioned upper mold 130 is provided with two slit forming projections 125A and 125B, it may be singular or three or more according to the number of slits formed on the blade plate 102 of the centrifugal multi-blade fan 100.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an embodiment of a centrifugal multi-blade fan manufactured using a molding die according to the present invention.
FIG. 2 is a sectional view of a main part of a centrifugal multi-blade fan manufactured in the embodiment.
FIG. 3 is an explanatory cross-sectional view illustrating a blowing state of a slit of a centrifugal multiblade fan manufactured in the embodiment.
FIG. 4 is an exploded perspective view showing a molding die of the centrifugal multi-blade fan according to the embodiment.
FIG. 5 is a sectional view taken along the line AA of FIG. 4 showing an assembled state of the molding die according to the embodiment.
FIG. 6 is a cross-sectional view showing a state in which a lower die and a punching die are removed from the molding die according to the embodiment.
FIG. 7 is a perspective view of a main part showing a conventional example.
[Explanation of symbols]
REFERENCE SIGNS LIST 100 Centrifugal multi-blade fan 101 Bottom plate 102 Wing plates 105A, 105B Slit 110 Lower mold 111 Bottom plate lower surface forming portion 114 Wing plate outer forming groove 120 Upper die 121 Wing plate inner forming groove 124 Side walls 125A, 125B Slit forming protrusions 130 Mold 131 blank

Claims (3)

A large number of blades (102) are spaced along the circumferential direction on the peripheral edge on one surface side of the bottom plate (101) in the form of a rotating body so as to be parallel to the rotation axis of the bottom plate (101). An air flow path is interposed between the wing plates (102), and a radially inner portion of the bottom plate (102) of the wing plate (102) is parallel to the rotation axis. A centrifugal multi-blade fan (100) having a slit (105A, 105B) formed along a direction,
A bottom plate lower surface forming portion (111) for forming a bottom surface of the bottom plate (101) is formed in an inner bottom portion, and a blade plate for forming the radially outer portion of the blade plate (102). A lower mold (110) having an outer forming groove (114) formed on the inner peripheral surface;
It has a cylindrical container shape fitted inside the lower mold (110), and is formed on the outer peripheral surface so as to correspond to the blade plate outer forming groove (114) formed in the lower mold (110). Forming a radially inner portion of the wing plate (102), having a groove width dimension longer than twice the thickness of the wing plate (102), and forming the slit (105A) in one side wall. , 105B), the upper die (120) including a blade plate inner forming groove (121) on which slit forming protrusions (125A, 125B) are protruded.
And a punching die (130) having an elongated plate-like punching piece (131) inserted into the blade inner forming groove (121) from above the upper die (120). A molding die for a centrifugal multi-blade fan (100). A molding die for a centrifugal multi-blade fan (100) according to claim 1, wherein:
Of the side walls (124) on both sides of the vane plate inner forming groove (121), at least the side wall (124) on the rotational drive direction side of the centrifugal multi-blade fan (100) faces in the direction opposite to the rotational drive direction. The slit forming projections (125A, 125B) protrude from the side wall (124) on the side of the rotational drive direction by the same dimension as the thickness dimension of the blade (102). A molding die for the multi-blade fan (100), which is provided as follows. A molding die for a centrifugal multi-blade fan (100) according to claim 2, wherein:
The molding die for a centrifugal multi-blade fan (100), wherein the slit-forming projections (125A, 125B) have a trapezoidal cross-section formed gradually narrower toward the tip.

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