JPH10205493A - Blower impeller and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blower impeller made of a metal to take a recycle, saving of resources, and coping with a PL method into consideration and have high performance and to provide manufacture thereof. SOLUTION: A blower impeller 2 is formed of a magnesium alloy, a hollow layer is formed at the internal part of a structure, and a hollow part is pressurized and held at a pressure higher than an atmospheric pressure. Thus, the blower impeller is light in weight and excellent in recycle properties. A manufacturing method is such that after the blower impeller is divided into constituting elements and molded, a joining portion is adhered or brazed. When a hollow part is pressurized and held, after the constituting elements of the blower impeller are joined together through bonding or brazing, a pin hole part is formed in a part thereof, and gas is injected through the pin hole. Thereafter, by closing the pin hole part, the hollow part of a blade type impeller forms a structure which is held at a pressure higher than an atmospheric pressure. This means improves workability of a work to bring the device into a hollow state and pressurize an internal part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blower impeller provided with an airfoil blade having a thickness effective for reducing noise.

[0002]

2. Description of the Related Art A blower impeller equipped with airfoil blades was made of metal when a large propeller fan was used in an outdoor unit of an air conditioner in the 1950s. However, with the passage of time, it was replaced by plastic. The reason is that plastic is suitable for mass production as a blower impeller that can obtain a large air volume with low noise.

[0003]

However, in recent years, while recycling of home appliances is desired, metal parts are easier to recycle than plastic parts.
It is recognized as a suitable material. Therefore, it is only necessary to return to the metal steel plate as in the past, but it has been very difficult to achieve the same performance level with the metal steel plate for the fan impeller, which has been improved in performance in recent years.

[0004] In addition, the outdoor unit of the air conditioner is required to be flame retardant in order to take measures against arson in compliance with the PL method.

SUMMARY OF THE INVENTION In view of the above-mentioned conventional problems, it is an object of the present invention to provide a high-performance metal blower impeller and a method of manufacturing the same in consideration of recycling, resource saving, and compliance with the PL method.

[0006]

According to the present invention, in order to solve the above-mentioned problems, recycling is facilitated by using a material made of a magnesium-based alloy, and the fan impeller can be made flame-retardant. In addition, it is possible to save resources by hollowing the inside of the structure. In addition, by maintaining the hollow portion of the airfoil at a pressure higher than the atmospheric pressure, the airfoil has sufficient resilience against deformation due to external force, thereby enabling further reduction in thickness.

[0007] As a manufacturing method, a blower impeller is divided into constituent elements, formed, and then joined to hollow. If hollowing is performed directly, the hollow state of the inner portion tends to vary, making it difficult to correct the rotational balance of the impeller. Dividing into components increases the number of man-hours, but is a preferable method for mass production considering stability of quality. Further, when the hollow portion is to be pressurized, after joining the molded product divided into the constituent elements, a pinhole portion is provided in a part, gas is injected from the pinhole portion, and then the pinhole portion is provided. Close up. If the joining and the pressurization of the hollow portion are performed at the same time, the joint must be fixedly held until the joint has sufficient strength. If it is a pinhole portion, the operation after pressurization is easy.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 for solving the above-mentioned problems is a blower impeller made of a magnesium-based alloy. According to this configuration, a lightweight metal alloy can be obtained.

According to the second aspect of the present invention, since the structure has the hollow layer inside, the weight and cost can be further reduced.

According to the third aspect of the present invention, since the hollow portion of the airfoil blade is kept at a pressure higher than the atmospheric pressure, an external force which becomes a problem in reliability when the thickness is reduced in pursuit of weight reduction is pursued. It can have sufficient resilience to deformation.

[0011] The invention according to claim 4 is a method for manufacturing a fan impeller in which a blower impeller is divided into components and molded, and a joining portion is bonded or brazed.
This makes it easy to achieve uniform hollowing inside.

Further, according to the present invention, after the blower impeller is divided into components and formed, the joint portion is bonded or brazed, and a pinhole portion is provided in a part, and the pinhole is provided. This is a method for manufacturing a blower impeller in which a gas is injected from a hole portion, and thereafter, the pinhole portion is closed to obtain a structure in which the hollow portion of the airfoil is held at a pressure higher than the atmospheric pressure. Is realized easily.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, a blower impeller 2 is located at the center of the outdoor unit main body 1 and is fixed to a bolt of a fan motor 3 with a nut 4 to supply air to a heat exchanger (not shown) to generate heat. It contributes to the exchange performance improvement.

(Example 1) Magnesium alloy (90M
g-10Al) chips (rice grains having a major axis of about 5 to 6 mm) by the thixomolding method.
A blower impeller of 50 mmφ was formed. The thixomolding method is a molding method in which a chip is heated to a temperature from a freezing point to a melting point in a cylinder to be in a semi-molten state in which a liquid phase and a solid phase coexist and injected into a mold. 550 in the embodiment
Heated to ５580 ° C. Magnesium alloy (90M
g-10Al) is a material having a specific gravity of about 1.82 and a low specific gravity as a metal. The core portion was designed to have a designed thickness of 1 mm because metallization can improve mechanical strength.

Comparative Example 1 A blower impeller having an outer dimension of 350 mmφ was formed using flame-retardant polypropylene. The specific gravity was 1.2, and the core portion had a designed thickness of 2 mm.

When comparing Example 1 with Comparative Example 1, the specific gravity of metal is heavier than that of plastic. There was no difference because the thickness was reduced by the improvement. Therefore, the metal was heavier by the airfoil blades as a whole. However, a flame retardant with a large environmental load is used for plastics, and it can be said that the examples are far more suitable parts in consideration of recycling and environmental impact.

Example 2 The same material as in Example 1 was used, and a blade impeller having an outer size of 350 mmφ was formed by thixomolding by dividing the airfoil blade so as to be hollow. Thereafter, the portion to be joined was fixed with a cyanoacrylate adhesive. FIG. 2 is a perspective view of the blower impeller so that the joints (dotted line portions and blade end surfaces) can be seen. At this time, the design thickness of the airfoil blade is 1.5 mm,
The core had a thickness of 1 mm.

Comparing Example 2 with Comparative Example 1, the overall weight was reduced in Example 2 by hollowing out the airfoil blade and setting the thickness to 1.5 mm.

In the second embodiment, the bonding portion is fixed with a cyanoacrylate-based adhesive capable of obtaining a sufficient adhesive strength in a short time, but other epoxy-based or vinyl acetate-based adhesives may be used. It was also possible to fix by brazing.

(Example 3) The same material as in Example 1 was used, and an airfoil impeller having an outer dimension of 350 mmφ was formed by a thixomolding method by dividing the airfoil blade so as to be hollow. Thereafter, a part of the joint of the airfoil was left as a pinhole (near the hub), and the other was fixed with a cyanoacrylate-based adhesive. At this time, the design thickness of the airfoil blade was 0.5 mm, and the design thickness of the core portion was 1 mm. Next, nitrogen gas was injected from the three pinholes via an elastic material so that the internal pressure became 1.5 kg / cm ² , and the elastic material was reinforced with an adhesive so as not to come off during practical use.

Comparing Example 3 with Comparative Example 1, the overall weight was much lighter in Example 3 by making the airfoil blade hollow and making the wall thickness 0.5 mm.

In the third embodiment, the internal pressure of the hollow portion is 1.5
The pressure was set to be kg / cm ² , but the internal pressure had to be correlated with the design thickness of the airfoil blade portion. That is, the internal pressure is made higher as the design thickness becomes thinner. This effect is effective as long as more than the atmospheric pressure, large pressure variation when too high, it is preferable to 2 kg / cm ² or less because workability come reduced. As the gas used for injection, nitrogen gas was used in the examples, but the gas is not limited to nitrogen gas, and dry air, carbon dioxide, and the like could also be used.

The pinhole portion set for gas injection has such a size that an injection needle can be inserted into an elastic material, and means about 3 mmφ or less.

(Embodiment 4) Using the same material as in Embodiment 1, the airfoil blade is divided so that the hollow portion becomes a continuous space via the core portion, and the outer dimensions of the airfoil blade are reduced by a thixomolding method.
A blower impeller of 50 mmφ was formed. Thereafter, the joint of the airfoil blade was fixed with a cyanoacrylate-based adhesive except for the pinhole portion arranged in the core portion. At this time, the design thickness of the airfoil blade was 0.5 mm, and the design thickness of the core portion was 1 mm. Next, nitrogen gas was injected from the pinhole portion of the core portion through the elastic material to an internal pressure of 1.5 kg / cm ² so that the elastic material was reinforced with an adhesive so as not to come off in practical use.

Comparing Example 4 with Comparative Example 1, the overall weight was much lighter in Example 4 by hollowing out the airfoil blade and making the wall thickness 0.5 mm. Further, when Examples 3 and 4 were compared, the workability in manufacturing was greatly improved by making the pinhole portion a continuous space.

In Examples 1 to 4, alloys with aluminum were shown, but manganese, zinc and the like could be used for the purpose of the present invention.

Using the fan impellers prepared in Examples 1 to 4, unit evaluation tests (severe tests and impact strength tests) were conducted based on practical use.

The severe test was repeated 10000 cycles at room temperature at 1300 rpm (1.3 times the maximum number of rotations used), one cycle of 25 seconds of operation and 5 seconds of stop. Thereafter, the presence or absence of abnormalities such as cracks and deformation was observed.

In the impact strength test, a blower impeller was attached to a falling weight impact test apparatus at room temperature, and 50 g of steel balls (100 g) were placed.
One cycle of vertically dropping each blade from a height of cm was repeated 100 times. Thereafter, when the blower impeller was rotated to 1000 rpm from the start, the presence or absence of abnormal noise was examined.

As a result, it was confirmed that the fan impellers of Examples 1 to 4 had no problem. The present invention is particularly characterized by the material of the blower impeller, but in places where there is a risk of salt damage, such as near the coast, a coating film or the like on the surface is required to enhance corrosion resistance. Therefore, a blower impeller surface coated with a coating film is also included in the scope of the present invention.

[0032]

As is apparent from the above embodiment, the invention according to claim 1 uses a material made of a magnesium-based alloy, so that recycling can be facilitated and the blower impeller can be made flame-retardant. .

According to the second aspect of the present invention, it is possible to save resources by hollowing the inside of the structure.

According to the third aspect of the present invention, by maintaining the hollow portion of the airfoil at a pressure higher than the atmospheric pressure, the airfoil has sufficient resilience against deformation due to an external force, thereby making it possible to further reduce the thickness.

According to the fourth aspect of the present invention, the workability of maintaining the pressure above the atmospheric pressure is improved by making the hollow portion between the core portion and the airfoil blade a continuous space.

According to a fifth aspect of the present invention, as a manufacturing method, a blower impeller is divided into constituent elements, formed and formed, and then joined to form a hollow, so that hollowing is performed more directly than hollowing is performed. Products with stable quality can be obtained.

According to a sixth aspect of the present invention, in the case where the hollow portion is pressurized, the molded product divided into the constituent elements is joined, and then a pinhole portion is provided in part, and By injecting a gas and then closing the pinhole portion, the workability of pressurizing the hollow portion is improved.

[Brief description of the drawings]

FIG. 1 is a partially exploded perspective view of an outdoor unit main body provided with an embodiment of the present invention.

FIG. 2 is a perspective view of a blower impeller obtained according to a second embodiment of the present invention.

[Explanation of symbols]

 1 Outdoor unit body 2 Blower impeller 3 Fan motor 4 Nut

Claims (6)

[Claims] 1. A fan impeller comprising a magnesium-based alloy. 2. The blower impeller according to claim 1, further comprising a hollow layer inside the structure. 3. The blower impeller according to claim 1, wherein the hollow portion of the airfoil is pressurized and held at a pressure higher than the atmospheric pressure. 4. The blower according to claim 1, wherein the core portion and the airfoil blade have a hollow portion, and the hollow portion is a continuous space and is pressurized and held at a pressure higher than the atmospheric pressure. Impeller. 5. A method for manufacturing a blower impeller, wherein the blower impeller is divided into components and molded, and then a joining portion is bonded or brazed. 6. After the blower impeller has been divided into components and formed, the joined portions are bonded or brazed.
A pinhole portion is provided in a part, a gas is injected from the pinhole portion, and thereafter, the hollow portion of the airfoil is obtained by closing the pinhole portion to obtain a structure in which the hollow portion is maintained at an atmospheric pressure or higher. Method of producing a blower impeller.