JP2005155437A - Impeller for blower - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lightweight impeller for a blower with excellent strength and good blowing performance. <P>SOLUTION: The impeller for a blower is equipped with a hub 2 and a plurality of wing type blades 3 composed of non-foaming material provided on the periphery of the hub 2. Recessed parts 10a are provided on the blades 3, and foaming parts 13 are formed by filling a foam resin or a thermoplastic elastomer into the recessed parts 10a. The impeller 1 for a blower can thereby be lightweight. Because the base of the blades 3 are formed of non-foaming material, they are hardly heat deformed and excellent in breakdown rotation strength. The blades 3 can be thickened as they are lightweight, thereby preventing noise and improving blowing performance. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an impeller for a blower used for an air conditioner or the like.

  As a conventional blower impeller, there has been one as shown in FIG. That is, the blower impeller 1 is formed of a cylindrical hub 2 and a plurality of wing-shaped blades 3 provided around the hub 2, and a central boss portion 4 (for fixing the motor) is used as a fan motor (see FIG. The air is blown by fixing the shaft to a shaft (not shown) and rotating the motor.

  The material of the impeller 1 for the blower used to use a metal such as a coated steel plate or an aluminum steel plate that has been press-processed and painted in recent years. And manufactured by injection molding (for example, see Patent Document 1).

  In addition, there is also one in which a foam material is mixed into the resin material of the entire fan wheel 1 for the blower (see, for example, Patent Documents 2 and 3).

Furthermore, a melted and bonded piece of a blade on a part of the blade (see, for example, Patent Document 4), or a blade is provided with a lid to make it hollow, and the blade thickness is about 3 to 15 mm in consideration of performance. A thicker one is also made. In addition, there is a type using a vibration isolator having a structure in which CR rubber is provided in a metal cylinder in order to reduce vibration from the fan motor in the boss portion (see, for example, Patent Document 5).
JP-A-9-228993 JP-A-8-4694 Japanese Patent Laid-Open No. 10-89298 JP 2000-345994 A Japanese Patent Laid-Open No. 10-47298

  However, in the case of making a blade having a thickness of about 5 to 15 mm, there is the following problem when foaming by mixing a normal chemical foaming agent as described above.

  When foaming agents, thermally expandable microcapsules, etc. are mixed into the molding material of the entire blower impeller and foamed at a high magnification, the molding cycle time becomes particularly long, and the blower impeller is thermally deformed at high speed rotation. It tends to be easy, and the breaking rotation strength tends to be low.

  Also, the method of attaching the lid to the wing-shaped blade by welding processing required post-processing after molding, and a somewhat conspicuous welding line appeared around the welded portion, which was unsightly in appearance. Further, when the cover plate is welded to the three-dimensional wing-shaped blade, a slight positional deviation occurs, and the yield is poor to secure a uniform hollow portion, resulting in poor productivity. Further, when the blade piece is foamed and the blade piece is melt-bonded, a post process of applying pressure by applying a hot plate or the like after molding is required.

  The present invention solves the above-mentioned conventional problems, and an object thereof is to provide an impeller for a blower that is excellent in strength, blowing performance, and productivity, and that is significantly reduced in weight.

  In order to solve the above-described conventional problems, an impeller for a blower according to the present invention includes a hub and a plurality of wing-shaped blades made of a non-foaming material and provided around the hub, and the blades have recesses. The foamed portion is formed by filling the concave portion with a foamed resin or a thermoplastic elastomer. The weight of the impeller for the blower can be reduced, and the resin at the base of the blade is formed by a non-foamed portion. A material having excellent breaking rotation strength is obtained. In particular, it becomes possible to make 700 g or less with a blower impeller having a diameter of 350 mm or more, and the burden on starting and rotating a fan motor that rotates a large blower impeller can be reduced. Moreover, since the blade can be made thicker as much as the weight can be reduced, the noise can be reduced and the blowing performance can be improved.

  The impeller for a blower of the present invention is lightweight, excellent in strength, and can contribute to energy saving and environmental aspects by reducing the electricity bill by improving the blowing performance accompanying the increase in blade thickness.

  A first invention includes a hub and a plurality of wing-shaped blades made of a non-foamed material and provided around the hub. The blade is provided with a recess, and the recess is filled with a foamed resin or a thermoplastic elastomer. Thus, the foamed portion is formed, and the impeller for the blower can be reduced in weight, and the resin at the base of the blade is formed by the non-foamed portion, so that a material having excellent thermal deformation and breaking rotation strength can be obtained. In particular, it becomes possible to make 700 g or less with a blower impeller having a diameter of 350 mm or more, and the burden on starting and rotating a fan motor that rotates a large blower impeller can be reduced. Moreover, since the blade can be made thicker as much as the weight can be reduced, the noise can be reduced and the blowing performance can be improved.

  In the second invention, in particular, the surface of the foamed portion of the first invention is formed by a non-foamed skin layer having a thickness of 0.2 to 2 mm. Even if a foreign object flies and hits it, it will not be greatly damaged.

  In the third invention, in particular, as the non-foaming material of the first or second invention, PP (polypropylene) resin, AS (acrylonitrile styrene) resin, A / EPDM / S (acrylonitrile ethylene propylene diene, Styrene) -based resin and ASA (acrylonitrile / styrene / acrylic ester) -based synthetic resin material is used. Light weight is achieved by using a synthetic resin material with a density of about 0.9 to 1.1. These resins can be easily subjected to weathering treatment, and the durability of 10 years or more can be secured even outdoors.

  In the fourth invention, in particular, as the non-foaming material of any one of the first to third inventions, one or two of calcium carbonate, talc (magnesium silicate), GF (glass fiber), and mica (mica) are used. A synthetic resin material mixed with ˜40% by weight is used, and the rigidity and heat resistance can be improved at a density of about 1.0 to 1.35, and the weight can be reduced. Similarly, it is easy to carry out weathering treatment, and it is possible to ensure durability of 10 years or more even outdoors.

  In the fifth invention, in particular, the foamed portion of any one of the first to fourth inventions is made of PP (polypropylene) resin, PE (polyethylene) resin, PS (polystyrene) resin, AS (acrylonitrile styrene). ) Resin, A / EPDM / S (acrylonitrile / ethylene propylene-diene / styrene) resin, ASA (acrylonitrile / styrene / acrylic ester) resin, PU (urethane) resin Therefore, the bondability between the resin in the non-foamed portion and the resin in the foamed portion is improved, and PP-based resin and PE-based resin foamed resin are suitable for the non-foamed portion of the PP-based resin. For non-foamed parts of AS resin, A / EPDM / S resin and ASA resin, the same resin foam resin or PS resin is suitable. Even if it is used for a long time as an impeller for a blower of an air conditioner, it does not peel at the joint between the non-foamed part and the foamed part.

  In the sixth invention, in particular, the foamed portion of any one of the first to fourth inventions is formed of an olefin-based thermoplastic elastomer or a styrene-based thermoplastic elastomer, and the resin of the non-foamed portion and the heat of the foamed portion. Bondability with the plastic elastomer is improved, and an olefin-based foamed thermoplastic elastomer is suitable for the non-foamed portion of the PP-based resin. Also, a styrene-based foamed thermoplastic elastomer of the same resin is suitable for the non-foamed portion of the AS resin, A / EPDM / S resin, and ASA resin. Due to the combination of these suitable resins and foamed thermoplastic elastomers, the non-foamed part and the foamed part are firmly fused. Even if used as an impeller for a blower of an air conditioner for a long time, the non-foamed part and the foamed part are foamed. It does not peel off at the joints.

  In the seventh invention, in particular, the apparent specific gravity of the foamed portion of the fifth or sixth invention is set to 0.05 to 0.5, and the amount of carbon dioxide in the critical state and the molding pressure are controlled. Thus, the filling amount and the expansion ratio change, and the weight can be adjusted. If the apparent specific gravity is in the range of 0.05 to 0.5, the shape can be stabilized and the weight can be reduced. In addition, an excellent blower impeller with less rotational breaking strength and thermal deformation can be obtained.

  In the eighth aspect of the invention, in particular, after the non-foamed portion made of the non-foamed material of any one of the first to seventh aspects is primary molded, the foamed portion is secondarily molded, and the mold is formed during the injection molding of the foamed portion. The core is expanded and integrally molded, and after molding the non-foamed part on the primary side, the non-foamed part and the foamed part are formed on the secondary side to fill the recessed part of the blade with foamed resin or foamed thermoplastic elastomer. Since it is firmly fused and the mold is core-backed, the expansion ratio is increased, the weight can be greatly reduced, and there is little occurrence of sink marks on the thick wings of the molded product.

  In the ninth invention, in particular, carbon dioxide in a supercritical state is used as the foaming agent used in the foaming portion of the seventh invention. In the foaming agent, the resin is plasticized in the critical state and fine. Since a large number of foam cells are formed, the blower impeller can be greatly reduced in weight as a blower impeller, and a foamed layer with little decrease in physical property strength can be formed, resulting in a blower impeller with little rotational breakage and thermal deformation.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1A is a perspective view of an impeller for a blower according to a first embodiment of the present invention, FIG. 1B is a perspective view of a blade of the impeller for the blower, and FIG. It is sectional drawing of an impeller. In addition, the same code | symbol is attached | subjected about the part same as a prior art example, and the description is abbreviate | omitted.

  In FIG. 1, a blower impeller 1 is formed of a cylindrical hub 2 and a plurality of blade-shaped blades 3 provided around the hub 2, and a fan motor (see FIG. A bearing 4 for fixing to a shaft (not shown) is provided.

  The thick wing portion 10 of the blade 3 is provided with a concave portion 10a in advance, and the concave portion 10a is filled with a foamed resin or a foamed thermoplastic elastomer and integrally molded. The molding is performed using a two-color molding machine. First, the non-foamed portion 12 of the base resin in which the concave portion 10a is provided in the blade 3 of the blower impeller 1 is molded on the primary side, and then the foamed resin or the heat of foaming is formed on the secondary side. A foamed portion 13 filled with a plastic elastomer and formed is formed.

Carbon dioxide gas (CO ₂ ) in a critical state as a physical foaming agent is used when molding the secondary side foamed resin or foamed thermoplastic elastomer. Carbon dioxide gas is highly soluble in the resin and the foamed cells are likely to be uniform. In addition, as a physical foaming agent, although a foaming cell becomes somewhat non-uniform | heterogenous, nitrogen gas can be used.

  Table 1 shows the amount of filler mixed together with Examples 1 to 16 in which the resin material of the non-foamed portion 12, the foamed portion 13, the type of filler, and the like were changed when the blower impeller 1 was molded in two colors. Resin density, fluidity MFI (melt flow index), apparent specific gravity of the foamed part, thickness of the skin layer 302 of the foamed part, weight of the molded product, and breaking speed of the molded product are shown.

  The blower impeller 1 in the above embodiment has three blades with a diameter of 410 mm, and the maximum thickness of the cross section at the center of the blade 3 is about 16 mm. When the noise of the impeller 1 for a blower is measured, the noise value is -0.5 to 1... 1 by setting the thickness of the blade 3 to about 16 mm as compared with a conventional blower impeller having a normal thickness of about 6 mm. The effect is about 5 dB.

  In Examples 15 and 16, a chemical foaming agent was used when molding the secondary side foamed resin or foamed thermoplastic elastomer. As the chemical foaming agent, azodicarboxylic acid amide or sodium hydrogen carbonate is used.

  Two-color molding is a molding method that is commonly used, and is a molding method that produces an integrated product made of two colors or two types of resin. For molding, a special machine equipped with two sets of injection devices is used. To do. A typical example of two-color molding is the first molding of the first color (first material) from the cylinder of the first injection device, and once the mold is opened and the primary molded product is adhered to the core side, the mold is 180 degrees. The mold is closed by rotating, the second color (second material) is molded from the cylinder of the second injection device, the mold is opened again, the molded product is taken out from the mold, and a two-color molded product is completed. In this case, two sets of molds, a primary mold and a secondary mold, are used. In actual operation, two sets of injection devices are operated almost simultaneously, and one shot of a molded product is obtained every half rotation. Other methods include attaching two sets of dies back-to-back around the vertical axis and half-rotating around the vertical axis, or for primary and secondary molding within a set of dies. There is a method of providing a set of cavities and cores.

In Examples 1 and 2, as shown in FIG. 3, the skin layer 14 of the non-foamed portion 12 is formed from a foamed portion 13 of 0.1 mm or less. Moreover, in Examples 3-16, the skin layer 14 of 0.2-2.0 mm is formed. As the synthetic resin material of the impeller 1 for the blower in Example 1, the synthetic resin material of the non-foamed portion 12 has a GF mixing amount of 20% by weight, a resin density of 1.14, a resin fluidity MFR (JIS-K). -7210, melt flow rate) is 230 ° C., 2.16 kgf / cm ² and 10 g / 10 min PP resin is used.

  Moreover, PP resin which does not contain a filler is used for the foamed part 13, and the apparent density of the foamed part 13 is about 0.05. The weight of the blower impeller 1 is 615 g, which is 185 g lighter than the conventional 800 g. The number of revolutions of the molded product is 3750 rpm, which is equal to or higher than that of the conventional example.

  Hereinafter, in Examples 2 to 16, the fillers having the contents shown in Table 1 are mixed and the apparent density of the foamed portion 13 is controlled to reduce the weight. In addition, the synthetic resin material of the foaming part 13 is PP resin in Examples 1 to 6, Example 7 is PU resin, Example 8 is PE resin, Example 9 is an olefin elastomer, Example 10 is AS resin, Example 11 is a styrene elastomer, Example 12 is an AES resin, Example 13 is an ASA resin, and Example 14 is a PS resin. In Examples 15 to 16, PP resin is used.

The apparent density of the foamed part 13 is roughly calculated by cutting out the foamed part 13 from the molded product after molding and dividing the weight of the foamed part by the volume. Is 20g / 200 cm ³ next time the foam part volume weight in 20g of 13 about 200 cm ^3, an apparent density is about 0.1.

  The number of revolutions of the molded product was determined when the boss 4 of the impeller 1 for the blower was fastened with a nut to the motor of the rotational destruction tester and fixed at a rate of 100 rpm per minute. This is the number of revolutions. The breaking rotation speed is an important characteristic as the strength of the blower impeller 1 and is considered to withstand strong winds of up to 30 m / second during outdoor typhoons. The number of revolutions varies depending on the weight and shape of the molded product, the type of synthetic resin material in the non-foamed portion 12, the type and amount of filler, the material of the foamed portion 13, the foamed state, and the like. Although the weight and the shape factor are large, by developing an appropriate synthetic resin material, a difference of about 1000 to 2000 rpm is produced even in the same shape. Therefore, it is possible to considerably increase the breaking rotation speed by improving the resin.

  Although the conventional example is 3600 rpm, Examples 1 to 14 have about 3650 to 3800 rpm, and the weight applied to the base of the blade 3 during rotation is reduced by the amount of lighter weight than that of the conventional example, thereby improving the strength. it can.

  In addition, the synthetic resin material used in the examples can improve the weather resistance by adding an appropriate amount of an ultraviolet ray inhibitor or an antioxidant when toning the resin material or mixing a filler. In particular, when used outdoors, PP, AS, AES, ASA, PE resin materials and olefin-based or styrene-based thermoplastic elastomers have excellent weather resistance, and it is possible to ensure durability of 10 years or more even outdoors. it can.

  When the apparent density of the foamed portion 13 is 0.5 or more, the weight of the molded product is reduced and the merit is reduced. Moreover, if it is 0.05 or less, weight reduction will become large, but molding time will become long and productivity will be inferior. Therefore, the range of 0.05 to 0.5 is desirable. Incidentally, when molding a foamed resin or a thermoplastic elastomer on the secondary side, the core back portion 15 can be formed by sliding an appropriate amount of the core back mold 6 as shown in FIG. A core back amount of about 2 to 5 mm is preferable for producing a fine cell of 200 μm or less by mixing carbon dioxide. If it is 5 mm or more, it is difficult to adjust the expansion ratio, and the molding time becomes long. On the other hand, if it is 2 mm or less, the apparent density of the foamed portion 13 tends to be 0.5 or more, and the expansion ratio tends to be small. In particular, in order to produce a fine cell of 50 μm or less, it is preferable to inject carbon dioxide into a cylinder of a molding machine in a supercritical state (critical temperature of 31 ° C. or higher and critical pressure of 73 atm or higher). Although it is possible even under the critical state, the cell diameter tends to be as large as about 0.5, and the surface irregularities tend to be large.

  Moreover, the thickness of the skin layer 14 of the foaming part 13 can be adjusted by controlling the foaming state and the molding cooling time on the secondary side. Further, in order to increase the expansion ratio, when a very small amount of talc, mica, GF, or calcium carbonate of about 1% by weight is added, they become the core material and easily foam. When the foaming state is low, the foaming state can be improved by adding less than 1% by weight of a chemical foaming agent. Also in this example, the foaming ratio is increased by mixing appropriately at less than 1%.

The synthetic resin material of the conventional example was injection-molded using a PP-based resin having a resin density of 1.14, a resin flowability MFI (melt flow index) of 230 ° C., 2.16 kgf / cm ² and 6 g / 10 min. Is. The blower impeller 1 used in the conventional example is also one having three blades with a diameter of 410 mm, and the maximum thickness of the cross-sectional portion at the center of the blade is 16 mm.

  As described above, the blower impeller of the present invention is lightweight and excellent in thermal deformation and breaking rotation strength, and thus can be widely applied to air conditioners, fans, blowers, power supplies, etc. that use fans. It is.

(A) Perspective view of impeller for blower in first embodiment of the present invention, (b) Perspective view of blade of impeller for blower Cross-sectional view of the blower impeller Sectional drawing of the impeller for blowers which shows another example Sectional view when the mold core back of the blower impeller A perspective view of a conventional impeller for a blower

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Impeller for blower 2 Hub 3 Blade 4 Boss part 10a Concave part 12 Non-foaming part 13 Foaming part 14 Skin layer

Claims (9)

A hub and a plurality of wing-shaped blades made of a non-foam material and provided around the hub are provided. The blade is provided with a recess, and the recess is filled with a foamed resin or a thermoplastic elastomer to form a foam portion. Impeller for blower. The impeller for a blower according to claim 1, wherein a surface of the foamed portion is formed of a non-foamed skin layer having a thickness of 0.2 to 2 mm. PP (polypropylene) resin, AS (acrylonitrile / styrene) resin, A / EPDM / S (acrylonitrile / ethylene propylene / diene / styrene) resin, ASA (acrylonitrile / styrene / acrylic acid ester) The impeller for a blower according to claim 1 or 2, wherein any one synthetic resin material of resin is used. The synthetic resin material in which 10 to 40% by weight of one or two of calcium carbonate, talc (magnesium silicate), GF (glass fiber), and mica (mica) is mixed is used as the non-foaming material. The blower impeller according to claim 1. PP (polypropylene) resin, PE (polyethylene) resin, PS (polystyrene) resin, AS (acrylonitrile / styrene) resin, A / EPDM / S (acrylonitrile / ethylene propylene / diene / styrene) The impeller for a blower according to any one of claims 1 to 4, wherein the impeller is formed of any one of a synthetic resin selected from a series resin, an ASA (acrylonitrile, styrene, acrylate) resin, and a PU (urethane) resin. The impeller for a blower according to any one of claims 1 to 4, wherein the foamed portion is formed of an olefin-based thermoplastic elastomer or a styrene-based thermoplastic elastomer. The blower impeller according to claim 5 or 6, wherein the apparent specific gravity of the foamed portion is 0.05 to 0.5. 8. A non-foamed portion made of a non-foamed material is first molded, and then the foamed portion is secondarily molded. When the foamed portion is injection-molded, the mold is core-backed and expanded and integrally molded. An impeller for a blower according to any one of the above. The impeller for a blower according to claim 7, wherein carbon dioxide in a supercritical state is used as the foaming agent.

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