JPH04262097A - Multi-blade fan - Google Patents

Abstract

PURPOSE:To surely fix a blade plate to a blade fitting plate with no backlash and improve the strength of an insertion portion. CONSTITUTION:A notch groove 19a is formed on the periphery section of a blade fitting plate 19, and a notch 20a corresponding to the notch groove 19a is formed on the edge section inside a blade plate 20. The blade plate 20 is inserted into the blade fitting plate 19 and fitted so that the notch groove 19a and the notch 20a are coupled with each other. A projection 23 pressed to the inner edge section of the notch groove 19a is draw-molded on the blade plate 20.

Description

[Detailed description of the invention]

[Object of the invention]

0002

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-blade fan used, for example, in a duct ventilation fan.

0003

2. Description of the Related Art For example, a centrifugal multi-blade fan is used in a duct ventilation fan. As shown in FIG. 6, this type of duct ventilation fan has a fan device 6 consisting of a motor 3, a multi-blade fan 4, and a fan casing 5 disposed inside a main body case 2 that is fitted into a portion of the ceiling of a building. By rotating the multi-blade fan 4, indoor air is sucked in and discharged from the duct 7.

The multi-blade fan 4 is constructed by attaching a large number of blade plates 9, also made of metal, to the outer periphery of a circular metal blade mounting plate 8 attached to the rotating shaft 3a of the motor 3. be done. In this case, the blade plate 9 is formed vertically long,
The middle part near the top is attached to the blade mounting plate 8, and the lower end part is connected and supported by an annular end plate 10.

In such a multi-blade fan 4, as shown in FIG. 6, a cut groove 8a is formed in the peripheral edge of the blade mounting plate 8, and the cut groove 8a is formed in the inner edge of the blade plate 9. A notch 9a corresponding to this is formed, and a notch 9b is also formed at the outer edge. and,
When attaching the blade plate 9 to the blade mounting plate 8, please refer to Figure 8.
As shown in FIG.
By inserting the blade plate 9 into the blade mounting plate 8 so that the blades fit into each other, and then caulking the open end portion of the cut groove 8a of the blade mounting plate 8 in the direction of arrow A using, for example, a roller, As shown in FIG.
I am trying to fix it to .

[0006]

By the way, in the multi-blade fan 4 as described above, the thickness of the blade plate 9 has been reduced (for example, by 0.4 mm) in order to improve performance such as weight reduction. It is being On the other hand, the width dimension of the cut groove 8a formed in the blade mounting plate 8 cannot be made very small due to problems such as the strength of the press die, and is at least about 0.8 mm.

Therefore, in the conventional multi-blade fan 4, the blade plate 9 is located within the cut groove 8a of the blade mounting plate 8.
There was a problem in that rattling was likely to occur, and so-called chattering noises were likely to occur.

[0008] Furthermore, the portion of the blade plate 9 between the notch 9a and the notch 9b (indicated by a in FIG. 7) is narrower than the other portions, so its strength is weaker. , the blade plate 9 is easy to bend around the part a as a fulcrum, especially,
If the upper end portion of the blade plate 9 (FIG. 7 is shown upside down from FIG. 6) is not fixed as described above, there is a risk that the free end side thereof may be bent. By the way, when we conducted a high-speed destructive test in which the multi-blade fan 4 was rotated at a much higher rotation speed than the normal rotation speed, the free end side of the blade plate 9 was bent toward the outer periphery (in the direction of arrow B in Fig. 7). It was seen that.

The present invention has been made in view of the above-mentioned circumstances, and its object is to provide a multi-function device that can securely fix the blade plate to the blade mounting plate without rattling, and also improve the strength of the blade plate. There is a wing fan to provide.

[Configuration of the invention]

[0011]

[Means for Solving the Problems] The multi-blade fan of the present invention includes:
A blade mounting plate is shaped like a disk and has a number of grooves formed on its periphery, and the intermediate part is fitted into each groove and attached to the blade mounting plate, and one of the two ends is interconnected and supported. The vane plate has a feature in that the vane plate has a convex portion that presses against the inner edge of the cut groove of the blade mounting plate.

0012

[Operation] According to the above means, the blade plate comes into pressure contact with the inner edge of the cut groove of the blade mounting plate by the convex portion, so that the situation where the width dimension of the cut groove becomes larger than the thickness dimension of the blade plate is avoided. Even if there is, the blade plate will be fixed to the blade mounting plate without wobbling. Further, the convex portion can improve the strength of the blade against bending.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a duct ventilation fan will be described below with reference to FIGS. 1 to 5. First, to briefly describe the overall configuration of the duct ventilation fan with reference to FIG.
It is attached to a mounting wooden frame 13 provided at part a by being fitted from below. An exhaust port 13a is provided on the right side of the main body case 11 in the figure, and one end of an exhaust duct 14 provided behind the ceiling 12 communicates with the exhaust port 13a. A fan device 15 is provided inside the main body case 11.

The fan device 15 is constructed by disposing a motor 17 and a multi-blade fan 18 according to this embodiment in a so-called spiral fan casing 16. The fan casing 16 has bell mouths 16a and 16b on the lower and upper surfaces, respectively, and the right side surface in the figure communicates with the exhaust port 13a. The motor 17 is
The fan casing 16 is attached to the inner part of the bell mouth 16b with the rotating shaft 17a facing downward, and at this time, a gap for ventilation is formed between the motor 17 and the bell mouth 16b. There is.

As will be described in detail later, the multi-blade fan 18 is
It is of a so-called double suction type, and includes a metal disk-shaped blade mounting plate 19, and a large number of metal blade plates whose upper middle portions are fitted and fixed around the periphery of this blade mounting plate 19. 20, and an annular end plate 21 that interconnects and supports the lower ends of the plurality of blade plates 20. The multi-blade fan 18 is attached with the center portion of the blade mounting plate 19 fitted onto the rotating shaft 17a of the motor 17.

[0016] Now, by rotating the multi-blade fan 18 by the rotation of the motor 17, the indoor air is circulated through the bell mouth 1.
6a, and is discharged from an exhaust port 13a through an exhaust duct 14 (indicated by arrow C in FIG. 3). In addition, the indoor air is removed from the main body case 11.
The fan casing 16 is sucked in through the upper bell mouth 16b through the space between the inner wall surface of the fan casing 16 and the outer surface of the fan casing 16, and is similarly discharged (indicated by arrow D). Furthermore, ceiling 12
The decorative frame 22 is placed in the opening 12a of the opening 12a.
It is installed to cover the room from the indoor side.

Now, regarding the multi-blade fan 18, FIG.
This will be explained in detail with reference to FIGS. 2, 4, and 5. 1, 2, 4, and 5, main parts of the multi-blade fan 18 are shown upside down compared to FIG. 3.

The blade mounting plate 19 has a disk shape as described above, and a plurality of grooves 19a into which the blade plates 20 are inserted are formed on the peripheral edge thereof in a direction slightly inclined with respect to the radial direction. It is formed to extend. This cut groove 19a is
Due to the strength of the press mold, its width b (see FIG. 5) is set to, for example, 0.8 mm. In addition, as will be described later, the open end portion of this cut groove 19a (the blade mounting plate 1
9) is caulked inward during the installation process of the blade plate 20. Furthermore, as shown in Fig. 4,
A similar cut groove 21a is also formed in the end plate 21.

On the other hand, the blade plate 20 has a vertically long strip shape with a thickness c (see FIG. 5) of, for example, 0.4 mm, and is located in the middle of the upper portion (lower portion in FIG. 4). A notch 20a that fits into the notch groove 19a is formed on the inner edge, and a notch 20b for caulking and fixing is formed on the outer edge. Similar notches 20c and 20d are also formed at the lower end (upper end in FIG. 4) of the blade plate 20.

The blade plate 20 has a convex portion 23 located between the notch 20a and the notch 20b.
is formed. In this embodiment, the convex portion 23 is formed by so-called drawing forming the vane plate 20 so that one side is bulged out into a substantially rectangular shape (the other side is depressed). Due to this convex portion 23, the thickness direction dimension d (see FIG. 5) of the entire blade plate 20 is slightly larger than 0.8 mm, so that the convex portion 23 is attached to the blade mounting plate as will be described later. It is adapted to come into pressure contact with the inner edge of the cut groove 19a of No. 19.

To attach the blade plate 20 to the blade mounting plate 19, first, as shown in FIGS. 4 and 5,
The blade plate 20 is inserted into the blade mounting plate 19 so that the cut groove 19a and the cut 20a fit into each other. Also,
At the same time, the end plate 21 is similarly inserted so that the cut grooves 21a and the cuts 20c fit into each other. At this time, since the thickness direction dimension d of the entire blade plate 20 is slightly larger than the width dimension b of the cut groove 19a due to the convex portion 23, the blade plate 20 is press-fitted into the cut groove 19a, so to speak. When fully inserted, the protrusion 23 comes into pressure contact with the inner edge of the cut groove 19a of the blade mounting plate 19, as shown in FIG.

After this, as shown in FIG.
The blade plate 20 is fixed to the blade mounting plate 19 as shown in FIG. 2 by caulking the open end portion of the cut groove 19a of the blade 9 in the direction of arrow E using, for example, a roller. Similar caulking is also performed on the end plate 21. A multi-blade fan 18 is constructed by attaching all the blade plates 20.

In the above configuration, the blade plate 20 comes into pressure contact with the inner edge of the cut groove 19a of the blade mounting plate 19 by the convex portion 23, so that the blade plate is made as thin as possible in order to improve performance such as weight reduction. Even if the width dimension b of the cut groove 19a becomes larger than the thickness dimension c of the blade plate 20 due to strength problems of the press mold, the blade plate 20 can be fixed to the blade mounting plate 19 without wobbling. become.

Furthermore, by forming the convex portion 23, it is possible to reinforce the portion between the notch 20a and the notch 20b, which is narrower than other portions of the blade plate 20. The strength of the portion inserted into the cut groove 19a, especially the strength against bending, can be improved. By the way, when we conducted a high-speed destructive test in which the multi-blade fan 18 was rotated at a much higher rotation speed than the normal rotation speed, the strength was improved by more than 20% compared to the multi-blade fan 4 described in the conventional example. It was confirmed that

As described above, according to this embodiment, unlike the conventional case in which the blade plate 9 easily rattles,
The blade plate 20 can be securely fixed to the blade mounting plate 19 without rattling. As a result, the occurrence of so-called chatter noise can be reliably prevented.

Furthermore, unlike the conventional blade plate 9 where the insertion portion a is weak and easily bent using that portion as a fulcrum, it is possible to improve the strength of the portion inserted into the cut groove 19a. . Therefore, even if the upper end portion of the blade plate 20 is a so-called free end that is not supported, bending and deformation of the blade plate 20 can be prevented.

It should be noted that the present invention is not limited to the above-mentioned embodiment, and can be implemented with appropriate modifications within the scope of the invention, for example, it can be used not only for duct ventilation fans but also for blowers in general. It's something you get.

[0028]

[Effects of the Invention] As is clear from the above explanation, according to the multi-blade fan of the present invention, the convex portion is formed on the blade plate to press against the inner edge of the cut groove of the blade mounting plate. This provides an excellent effect in that it can be securely fixed to the blade mounting plate without rattling, and the strength of the blade plate can also be improved.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the present invention, and is a cross-sectional plan view of the main parts before caulking.

[Figure 2] Cross-sectional plan view of main parts after caulking

[Figure 3] Vertical cross-sectional view of a duct ventilation fan

[Figure 4] An exploded perspective view of the main parts showing how the blade plate is assembled to the blade mounting plate

[Figure 5] A cross-sectional plan view of the main parts showing how the blade plate is assembled to the blade mounting plate

[Figure 6] A diagram equivalent to Figure 3 showing a conventional example

[Fig. 7] Equivalent view to Fig. 4

[Figure 8] Equivalent view to Figure 1

[Figure 9] Equivalent view to Figure 2

[Explanation of symbols]

18 is a multi-blade fan, 19 is a blade mounting plate, 19a is a cut groove, 20 is a blade plate, 20a is a cut, 21 is an end plate, 23
indicates a convex portion.

Claims (1)

[Claims] 1. A blade mounting plate that is attached to a rotating shaft and has a disc shape and has a number of notched grooves formed in its peripheral edge, and a blade mounting plate that has an intermediate portion fitted into each of the notched grooves. A plurality of blade plates are attached to the blade plate and one end of the blades is connected and supported to each other, and the blade plate is provided with an inner edge of the cut groove of the blade mounting plate. A multi-blade fan characterized by forming convex portions that press against each other.