JPS6189997A - Centrifugal fan - Google Patents

Abstract

PURPOSE:To establish improvement of blowing performance and a low cost by making the blade of a centrifugal fan of the steel plate and bending in a curl shape the outer edge and inner edge of the blade to prevent transformation and eddy current. CONSTITUTION:A curl portion 3 is formed on the inner edge 1a and outer edge 1b of a blade 1 attached to the circumferential edge of a runner body. Because a frictional sound is generated at the rotating time when the top end of a curl portion 3 makes contact with the stem of the blade, it is separated from the blade stem 1mm approximately. According to the foregoing constitution, transformation and bending at the rotating time can be reduced, occurrence of eddy current also be prevented, therefore vibration be reduced and blowing performance also be improved. However, the thin plate steel can be used for processing the universal material surface having a high marketing capability, both the blade and main plate can be constituted of the thin plate material of the universal material surface processing steel plate to establish lightness, and therefore they can be used as a labor saving material. Thus, the cost down for the entire equipment can be established.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a centrifugal fan made of steel plate that is incorporated into an air conditioner, and specifically relates to a fan such as a turbo fan, a fan, etc. .

<Conventional technology> Conventionally, when manufacturing the large (large diameter) centrifugal fans that are commonly used, one approach is to use aluminum for the components that make up the centrifugal fan in order to reduce the weight of the centrifugal fan. There is. However, in this case, in order to ensure the strength of the centrifugal fan, a thick aluminum plate is required as shown in Japanese Patent Publication No. 3G-5589, which has the disadvantage of requiring a huge amount of material cost compared to steel plate. .

Another possibility is to use steel plates for the blades of centrifugal fans.
The weight of the parts required to ensure strength is several times that of aluminum. The heavy weight of such centrifugal fans is due to an increase in the capacity of the motor that drives the fan, an increase in the size of the motor bearing that supports the fan, an increase in the complexity of the frame structure of the air conditioner in which these fans are incorporated, an increase in weight, and a complicated design. It has the disadvantage of requiring a one-defense design. As the use of steel plates for the blades,
For example, there is a type disclosed in Japanese Patent Publication No. 37-12327 in which the blades are made into an arcuate shape to increase the strength, but this has the disadvantage that the air blowing performance (noise noise) deteriorates.

Furthermore, it is possible to use synthetic resin for the components that make up the centrifugal fan, but in order to ensure the strength of the centrifugal fan, a large amount of synthetic resin would be required, and in this case, the manufacturing mold would require a huge amount of cost. It has drawbacks such as the

When moving (rotating) a large (large diameter) centrifugal fan, if the strength of the blades is insufficient, problems such as blade deformation, bending, and sometimes destruction may occur. This is due to the large centrifugal force acting on the blades due to the large diameter.

Therefore, if we try to obtain a sufficient blade strength of 1!7, the above-mentioned drawbacks will appear.

<Problems to be Solved by the Invention> In view of the above-mentioned circumstances, the present invention provides a lightweight centrifugal fan that uses the cheapest and most marketable steel plate as the blade material, has good air blowing performance, and is extremely strong. It is intended to provide.

<Means for Solving the Problems> In the present invention, the blades of a centrifugal fan are made of steel plates, and the inner and outer edges thereof are bent into a curled shape.

<Function> By bending both the inner and outer edges of the blade in this way (see curled part 3 in Figure 4), the strength is increased by 6 points compared to a simple flat blade without a bent part (see Figure 1), and The air blowing performance is also improved compared to circular blades (see Figures 10 and 11 ■).

<Example> Hereinafter, the present invention will be described in detail with reference to the drawings of the example.

1 to 4 show a turbo fan type, in which 1 is a blade attached to the periphery of an impeller main body 2, and curled portions 3 are formed on the inner edge 1a and outer edge 1b of the separate impeller Mi1. The impeller main body 2 consists of a main plate 2b having an annular side plate 2a on the front side and a seat push part 2C on the back side, the peripheral edge of the main plate 2b is a curled part 4, and the main plate 2b has a backing plate 5 serving as a bearing in the center. are arranged, making the total fan 6.

When assembling the fan 6, the caulking protrusions 7 protruding from both ends of the rectangular blades 1 are inserted into long holes 8 drilled in the annular side plate 2a and the main plate 2b, and then twisted. A. In this case, feather 1
By installing the curled portion 3 so as to be located on the rotational direction side of the fan 6, the air flow a does not collide with the curled portion 3 and no vortex is generated, resulting in good air blowing performance (Fig. 10).

(See Figure 11). However, the tip of the curled part 3 should be set at 1 mm because it will generate a chattering sound when rotating if it comes into contact with the main part of the blade.
They are separated by a certain degree (see Figure 3).

To explain this function now, first of all, the most important component of the centrifugal fan 6 is the blade 1, and the key is to have good air blowing performance and a strong blade shape. Further, during manufacture, a blade is required that is easy to assemble and has a shape that can improve strength. As for the bullet hole test of these various types of blades, the results shown in Figure 9 were obtained.

This is the pressing force (kg
) shows the results of the test.

However, blade test sample width: 40 x width: 130, blade shape: ■, ■ is curled at both ends, ■ is a flat plate, ■ is an arc, ■
：Curl and close contact are used together, ■：Both ends are close together and 2 beads, ■：Both ends are close together and 1 bead, ■：Both ends are close together.

That is, according to this chart, it can be seen that it is effective in terms of strength to make both ends of the blade curled. How the strength-related shape of a blade affects its air blowing performance can be determined by knowing how the air flows inside the blade. However, it is difficult to visually capture the streamlines inside the blades, so we set up several blade models that affect the streamlines and measured the air blowing performance (air volume and rotation speed, air volume and noise) of each. . It can be said that a blade with good air blowing performance has a good blade shape along the streamline.

This result is not shown in the M2O diagram and FIG. However, the blade in this case has a length of 130 mm and a medium size of 4. □mm, wall thickness 0.
This data was measured using a turbo fan (420 mm outer diameter, 370 mm inner diameter) with 40 5 mm blades tilted at 30 degrees installed in a ceiling-mounted air conditioner (see Figure 6).

That is, it can be seen that the blade (2) with curled ends on the side of the rotation direction of the fan and the flat blade (2) have the best characteristics (while the blade (2) with both ends curled on the side opposite to the rotation direction has somewhat inferior characteristics.

From the test results, it is thought that the streamlines inside the blade are as shown in FIGS. 3 and 5.

We were able to create a special blade shape that has good air blowing performance and is strong.

In addition, in order to increase the size of the 8-hung suspension, as shown in Figure 6, it is necessary to increase the inner diameter λ of the suction nozzle and enlarge the suction nozzle opening. Unavoidably, it becomes weaker. The present invention focuses on this point.

In the figure, 10 is a motor, 11 is a heat exchanger, and 112 is a discharge port.

As mentioned in Section 1, the most effective blade shape for a turbo fan is shown in Figure 3. The blade shape shown in FIG. 8 as well as other embodiment shapes are conceivable.

Further, as another embodiment, the use of a sirocco fan is shown in FIG. In this case, the curled portion 3 of the wing +fl 1 is positioned in the opposite direction to the direction of rotation.

Furthermore, regarding the strength of the main plate 2b, which is the blade base body 2, by forming the blade shape with curled portions 3, etc. as in the specific embodiment, there is very little deformation and deflection in the stationary state or during rotation! There are fewer periodic and non-periodic fluctuations. We will give a good award to Jt Men. In addition, by making the outer peripheral cross-sectional shape of the main plate 2b into a curled portion 4, etc., the flatness is excellent and the strength is improved, so surface runout and center runout are minimized during rotation, and there is also less vibration noise and quality is improved. It gets much better.

Shikara, Feather 1. Along with the IE board, it is possible to use thin plate material PT, which is a general-purpose surface-treated copper plate, which is a marketable material. b is sufficient, making it an energy-saving type.

Also, regarding the equipment for forming the blades and main plate,
Because parts can be formed using compression molding processing, roll molding processing, etc., there is no need for new large-capacity equipment, and versatile equipment is required, and the quality has also been achieved in the above-mentioned versatile thin sheet forest material 1 quality. Therefore, in conjunction with the low-output motor, the other parts that hold the motor itself can be made of thin plate material due to the strong epidemic and quality, which can lead to cost reductions for the entire device.

<Effects of the Invention> As described above, the centrifugal fan of the present invention has the following effects because the inner and outer edges of the blades are bent.

■It is possible to make a centrifugal fan that is as lightweight as aluminum using steel plate, which has the lowest material cost. Good ventilation performance. That is, it is now possible to use the blade U14SPG (14&) with a plate thickness of 0.5t (0.51nm).

In order to produce 1q of blades with the same strength using the conventional method, it would require a plate thickness of 3t (3mm) of aluminum, making it possible to significantly reduce costs.

1. Due to the weight reduction, it has become possible to downsize the centrifugal fan drive motor by eight.

■, 1 of the framework structure of the air conditioner that incorporates this centrifugal fan!
It is possible to increase crop production and reduce crop production. .

IV, IVj J & Machine 11i is I! ri 'li T
-1Low 1 & rib, low noise is now possible.

V, it becomes possible to incorporate iron plate air blowers of 400φ or more into small air conditioners (conventional iron plate flat blades (R requires a blade thickness of 1.st (1.6 mm), and blades ff1f).
i becomes 3 times or more. Furthermore, if we also consider the impact on the main plate that supports the blade, the total area of the blade and main plate becomes enormous.

).

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a partially cutaway front view of a turbo fan, FIG. 2 is a sectional view taken along line A-A in FIG. 1, and FIG.
FIG. 3 is an enlarged sectional view of the main part of the blade, FIG. 4 is a slope view of the blade, and FIG. 5 is an enlarged sectional view showing another attachment state of the blade.
Fig. 6 is a cross-sectional view of a ceiling-mounted air conditioner installed, Fig. 7 is a front view of another embodiment of the sirocco fan, and Fig. 8 is a front view of another embodiment of the blade. A cross-sectional view, FIG. 9 is a chart showing pressure test results for various blade shapes, and FIGS. 10 and 11 are a noise chart and a wind fn chart for the blade shape and air blowing performance. 1... impeller, 2... impeller body, 3... curl part. Figure 1, A Figure 4 Figure 10

Claims (1)

[Claims] 1. A centrifugal fan characterized in that the inner and outer edges of blades made of steel plates are bent. 2. Claim 1 where the bending is in a curled shape
Centrifugal fan as described in section.