JPH08277799A - Impeller for multiblade centrifugal blower - Google Patents

Abstract

PURPOSE: To enable the light weight and the decrease of noise by making a blade composed of a metallic vane attaching part and a non-metallic vane part put on and fixed to the vane attaching part, making a center disc composed of a metallic disc base plate and a non-metallic receiving part fixed on the disc base plate, and fixing the receiving part and the vane part. CONSTITUTION: Coil materials made of metallic plates are sequentially pressed, vane attaching parts 5 are continuously cut and raised, the continuous vane attaching parts 5 are set in outsert injection molding dies by using positioning holes for press work, and vane parts 6 are injection-molded to the vane attaching parts 5. Moreover, only the required number of blades are cut, rounded into cylinders, both ends of each cylindrical body is curled, and an end ring is formed. A metallic center disc is inserted into the cylindrical body, and an impeller is formed. Plastic receiving parts 15 are attached to a disc base plate 14 in the center disc, and the vane parts 6 are inserted into the receiving parts 15 and stuck and ultrasonic-welded. Therefore, the light weight and the low noise can be achieved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double suction impeller (hereinafter simply referred to as an impeller) of a forward-direction multi-blade centrifugal blower (commonly known as a sirocco fan) used in devices for air conditioning, ventilation, exhaust, equipment cooling, etc. Referred to as)) structure.

[0002]

2. Description of the Related Art Conventional impellers are roughly classified into the following three types according to their materials and manufacturing methods.

In the A type, a large number of independent metal blades (hereinafter referred to as blades) are fixed to two facing metal end rings by caulking, goby folding, welding, etc. A cylindrical body is formed, and one or two center disks are inserted into the central portion thereof, and the blade and the center disk are fixed by caulking or the like to form an impeller. An excellent example of the prior application is US Pat. No. 2,285,182.

In the B type, a large number of blades are cut and raised on a single metal plate by press working, and rolled into a cylindrical shape.
Weld the butting part, curl both ends to form a cylinder, insert the center disk in the center,
The blade and center disk are fixed by caulking or the like to form an impeller. An excellent prior application is U.S. Pat. No. 3,335,482.

In the C type, two one-sided suction impellers made by injection molding a plastic material are fixed back to back to form a wheel. There is no previous application.

The above three types of impellers have the following advantages and disadvantages.

A type is a blade, an end ring,
The rigidity of the impeller is inferior because several points of the three kinds of parts of the center disk are assembled, and therefore the metal plate is made thicker to cover and becomes heavy. Assembling the pick-up point of the number of parts is inferior in productivity, and machining error and assembly error are accumulated, resulting in inferior cylindricity and new circularity and poor dynamic balance. The blade is made of metal with high natural frequency such as steel and aluminum, so noise is high. Since the blade cross section is an arc shape made of a metal plate with a certain thickness, gas separation and vortex occur, resulting in poor aerodynamic characteristics and noise characteristics.

Since the B type has a structure with high rigidity, it is thin and lightweight. Since the number of parts is small (2
Type 2) Good productivity and little accumulation of machining and assembly errors, resulting in excellent cylindricity and new circularity, and good dynamic balance. Since it is formed of a metal plate, it is inferior in aerodynamic characteristics and noise characteristics like the A type. On a limited circumference,
Since a large number of blades are cut and raised, there are restrictions in designing the blade width (radial direction) and the number of blades, and it is difficult to obtain the required air volume and pressure.

Since the C type material is inferior in strength to a metal plate, an impeller having a large diameter and a wide width has a disadvantage that it cannot withstand centrifugal force and is destroyed. Physical properties of plastics have the drawback of high temperature creep, and there are restrictions on where they can be operated. However, since plastic has a low natural frequency, it has low noise. Since the blade can be formed into a blade-shaped cross-sectional shape, it produces the least gas separation and eddies, and is the most excellent in aerodynamic and noise characteristics.

As described above, since each of the three types has merits and demerits and there is no full blower, the suboptimal wheel is selected and used depending on the driving place and driving conditions.

[0011]

In recent years, there are many cases where a blower is installed close to a living space or a working space, and there is a strong demand for high efficiency and low noise of the blower. At the same time, further downsizing is required, so that the blower is forced to operate at high speed, and especially in the air conditioner and the ventilator.
From the viewpoint of effective use of the floor, the ceiling embedded type or the ceiling hanging type is increasing. Therefore, further weight reduction and low noise of the blower are required. This required level cannot be solved at all by the structure and manufacturing method of the conventional impeller described above.

[0012]

Originally, an impeller of a blower is required to have two different functions at the same time. One is the function as a fluid device (aerodynamic characteristics and noise characteristics such as ventilation efficiency and low noise), and the other is the function as a high-speed rotating body (mechanical characteristics such as rigidity and dynamic balance). Have a relationship. That is, in order to increase the rigidity as the function of the rotating body, the structure in which the blade is beaded is optimal, but since the fluid separates on the surface of the blade, the function as a fluid device is significantly reduced. Further, a plastic material is most suitable for reducing noise as a fluid device function, but the strength and rigidity, which are functions as a rotating body, are reduced due to insufficient material strength. In the design of the conventional impeller, since the requirements of this trade-off were pursued at the same time, only a halfway result, which is a product of compromise between the two, was obtained. In the present invention, these two functions, "the blade which is an ideal fluid machine" and "the car which is an ideal high speed rotating body" are first separated and thoroughly pursued, and then the two are combined. The problem was solved by a new design method of obtaining an "ideal blade / wheel".

A designing / manufacturing method according to the present invention will be described with reference to FIGS.

1. First, let's start with the design of a "car". Among the above 3 types of wheels, B type, which is the most excellent as a rotating body, is selected as the basic structure of the "car", and the optimal metal material is adopted for the operating conditions of the blower. Next, the “blade” or blade 3 which has conventionally pursued two functions at the same time is separated into a wing portion 6 which is a component of a fluid device and a wing attachment portion 5 which is a component as a rotating body. To pursue. A bead 7, which is strictly prohibited as a fluid device, is formed and provided on the blade mounting portion 5 formed by continuously cutting and raising a single metal plate, and then the metal plate is rolled into a cylindrical shape to form an end portion. Are welded to each other to obtain a cylindrical body 10. If both end portions of this cylindrical body 10 are curled to form the end rings 1 and 2, a stronger cylindrical body is obtained. By inserting the disk 4 into the center of this cylindrical body and fixing it to the blade mounting portion 5 by adhesion or the like, an ideal rotating body "car" can be obtained. As the material of this “car”, a metal plate (eg steel, stainless steel, aluminum, titanium, etc.) suitable for the operating conditions of the blower may be selected.

2. In this way, since the blade mounting portion 5 takes charge of the function of the "car" as the rotating body, the blade portion 6 only needs to pursue the function of the "blade" as the fluid device. As a result, it has become possible to use a material that was conventionally optimal for fluid equipment but was unsuitable as a rotating body due to insufficient strength, insufficient rigidity, creep properties, etc. It is possible for the designer to design and manufacture a blade with the optimum shape by adopting the optimum material (for example, plastics, ceramics) only for the condition of the “blade” without considering strength, rigidity and creep. became.

3. The most general manufacturing method according to the present invention is
Blade mounting part 5 by progressive press working of coil material of metal plate
Are continuously cut and raised to form the intermediate material 9 shown in FIG.
The width of the feed rail is 1 to 3 mm wider than that of the normal progressive feed press working, and the positioning hole 11 is opened for each blade mounting portion 5.
Next, using the positioning hole 11 for press working as a positioning hole, the continuous blade mounting portion 5 is set in the outsert injection molding die, and the blade portion 6 is injection molded into the blade mounting portion 5.
Using the positioning holes 11, the required number of blades is cut accurately. Roll it into a cylinder. The butting portion is welded to form the cylinder 10 shown in FIG. Both ends of the cylindrical body 10 having the width of the feed rail are curled to form the end rings 1 and 2, and a strong cylindrical body 20 is manufactured. A metallic center disk is inserted into and fixed to the cylindrical body 20 to complete the impeller. An example of this fixing method is shown in FIG. That is, the center disk 4a has a structure in which the plastic receiving portion 15 is attached to the disk substrate 14, and the wing portion 6 is inserted into the receiving portion 15 and is fixed by adhesion or ultrasonic welding. As another example, FIG.
There is a method shown in 2. That is, the center disk 4b
The groove-shaped receiving portion 1 is formed on the outer peripheral portion by press molding.
2 are provided. The blade portion 6 is inserted into the groove-shaped receiving portion 12, and the central portion 13 between the groove and the groove is strongly forged to narrow the groove width, and the blade portion 6 is pinched and fixed to the groove-shaped receiving portion 12. In order to increase the effect of narrowing the groove width, a concave or convex protrusion 17 is provided in the central portion 13 between the grooves, and after the blade 3 is inserted into the groove-shaped receiving portion 12, the protrusion 17 is strongly pressed. Then
There is also a method of making it almost flat. Either way,
It is important to pinch the wing portion 6 with the surface X of the groove-shaped receiving portion 12. If the wing portion 6 is pinched by the edge of the groove-shaped receiving portion 12, the wing portion 6 will be damaged and will eventually be destroyed. Also, the wings 6
There is also a method in which the groove between the groove-shaped receiving portion 12 and the surface X is recessed to provide a seat for the surface X to more securely fix the groove-shaped receiving portion 12 and the blade portion 6. In the step (1), a short material may be used instead of the coil material. In addition, as a modification of the process, the blade portion 6 is attached to the blade attaching portion 5 by manually covering the blade attaching portion 5 with the blade portion 6 obtained by cutting an extruded material having a blade-shaped cross section. Alternatively, the blade 3 may be formed by bonding.

[0017]

First Embodiment A preferred embodiment of the present invention will be described with reference to FIGS. This embodiment is an impeller (bore diameter 284 mm, width 240 mm, number of blades 48, blade arc length 29.0 mm) of a double suction type sirocco fan used for a ceiling embedded type of an air handling unit which is a type of air conditioner. is there. Conventionally, the A type impeller was used, but the weight reduction (2.8 kg to 2.1 k
g) and noise reduction (from 56 db to 53 db) were required. In B type impeller, the arc length of the blade is 18.6 m.
Since it is as short as m, the air volume and pressure do not reach the required level. Since the C-type impeller is provided with an auxiliary heater near it, the impeller creep-deforms due to heat and eventually is destroyed.

1. A design procedure according to the present invention will be described. Basic specifications of conventional impeller (caliber 284 mm, width 240
mm, the number of blades is 48, and the arc length of the blade is 29 mm). Choose B type as the basic structure of "car".
Therefore, the arc length of the blade attachment portion 5 is the outer circumference (892.
8 mm) divided by the number of blades 48 is 18.6 mm. A bead 7 is provided on the blade attachment portion 5 in parallel with the blade width direction to enhance rigidity. The blade mounting portion 5 is provided with a small hole 8 for fixing the common material to enhance the adhesiveness with the blade portion 6. An airfoil-shaped plastic injection-molded product having an arc length of 29 mm is adopted for the wing portion 6. The 48 blade attachment portions 5 and the end rings 1 and 2 are made of a single metal plate, and the left and right ends of the blade attachment portion are connected to the end rings. The blade mounting portion 5 and the end rings 1 and 2 are made of zinc-plated steel sheet having a thickness of 0.4 mm. A continuous blade plate 16 including a blade mounting portion 5 covering the blade portion 6 and end rings 1 and 2.
(Fig. 8) is rolled to form a cylinder, and 17a and 17
b is abutted, and the abutting surface is welded by a plasma welding method or the like to obtain a cylindrical body 10. Next, both ends of the cylindrical body 10 are curled to enhance rigidity, and thus the cylindrical body 20 is manufactured.
Get. The center disk 4a is obtained by attaching the plastic receiving portion 15 to the disk substrate 14 made of a galvanized steel plate. The center disk 4a is inserted into the cylindrical body 20, and the 48 blades 3 provided on the cylindrical body 20 have four blades.
The impeller is completed by being inserted into the grooves of the eight receiving portions 15 and fixed at predetermined positions by adhesion or welding. As another design example of the method of fixing the center disk and the blade, the groove-shaped receiving portion 12 press-molded on the outer peripheral portion of the disk substrate is used.
There is a center disk 4b having This groove-shaped receiving portion 1
After inserting the blade 3 into the groove 2, the intermediate portion 13 between the grooves
There is also a method in which the blade 3 is strongly forged to reduce the width of the groove and the blade 3 is pressed and fixed.

2. Next, a manufacturing procedure according to the present invention will be described. Galvanized steel plate (plate thickness 0.4 mm, plate width 260 m
(m ・ coil material) by progressive press forming, the blade mounting parts 5 are provided at equal intervals (18.6 mm), and two beads (width 2 mm, height 1.5 mm) are inserted parallel to the plate width direction. Reinforce. Further, small holes 8 for fixing the common material having a diameter of about 2 to 5 mm are formed in each of the left and right end portions of the blade mounting portion 5 at one location and at several locations inside. The feed bar for progressive press working and the positioning pilot hole 11 formed in the feed bar are left as they are and used as a positioning hole in the next step.
The blades 6 are formed on the blade mounting portions 5 by outsert injection molding using heat-resistant plastic as a material, and at the same time, the blades 6 are mounted and covered to form blades. In the small hole 8,
The injected resins are welded to each other and integrated, and the problem such as separation between the metal blade mounting portion 5 and the plastic blade portion 6 is solved. Next, the continuous blade plate 16 provided with the 48 blades 3 is rolled to form a cylinder, both ends 17a and 17b are butted, and the mating surfaces are joined by plasma welding to obtain the cylindrical body 10. Next, both ends of the cylindrical shape are curled to strengthen the rigidity of the cylindrical body. Next, the center disk 4a having 48 plastic receiving parts 15
The cylindrical body 20 is arranged so that the blade portion 6 fits in the groove of the receiving portion 15.
And fixed by means such as adhesion or ultrasonic welding to complete the impeller. The state is shown in FIG. Alternatively, a fixing method using one or two center disks 4b described above may be used. This state is shown in FIGS. 13 and 14. The impeller designed and manufactured in this way weighs only 2.0 kg, and the noise is 52.5 d.
b and the required level were achieved.

[0020]

[Example 2] When corrosive gas is present as in a ventilation or exhaust system of a chemical factory, an aluminum alloy plate or a stainless plate is used.

[0021]

Example 3 A ceramic material is used for the blade when hot gas is present.

[0022]

[Embodiment 4] Since the impeller has a very large volume as compared with its weight, it is not efficient to carry it as a finished product. Therefore, the press intermediate material 9 having a continuous blade is wound into a coil without being cut off, the center disk is housed in the space at the center, and sent to the factories all over the world. If you use it to separate the required number of blades and assemble the impeller, you can easily make an impeller at low cost anywhere in the world.

[0023]

As described above, according to the present invention, since the degree of freedom in design is increased, it is possible to design the material most suitable for the operating conditions of the blower into the optimum shape. Therefore, in combination with the effect of the manufacturing method according to the present invention, 25% weight reduction and 6% noise reduction are possible. The larger the impeller, the greater this effect.

[Brief description of drawings]

FIG. 1 is a side view of a cross section of an impeller showing an embodiment of the present invention. This drawing is an example in which the center disk 4a is adopted.

FIG. 2 is a partially enlarged view of FIG.

FIG. 3 is a front view of a cross section on one side of an impeller showing an embodiment of the present invention.

FIG. 4 is a partially enlarged view of FIG.

FIG. 5 is a plan view of a press working intermediate material 9.

FIG. 6 is a front view of a central cross section of a press working intermediate material 9.

FIG. 7 is a side view of a press-working intermediate material 9.

FIG. 8 is a side view of a continuous blade plate 16 in which a blade portion 6 is provided on a blade attachment portion 5 of a press working intermediate material 9.

FIG. 9 is a perspective view of the cylindrical body 10.

FIG. 10 is a perspective view of a cylindrical body 20.

FIG. 11 is an explanatory diagram of a center disk 4a.

FIG. 12 is an explanatory diagram of a center disk 4b.

FIG. 13 is an explanatory diagram of a method of fixing the blade that employs the center disk 4b.

FIG. 14 is an explanatory diagram of a method of fixing a blade that employs two center disks 4b.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 End ring 2 End ring 3 Blade 4 Center disk 5 Blade mounting part 6 Wing part 7 Bead 8 Small hole 9 Pressing intermediate material 10 Cylindrical body 11 Pilot hole 12 Groove receiving part 13 Center part of groove part and groove part 14 Disk base part 15 Receiving part 16 Continuous blade plate 17 Central uneven part 20 Cylindrical body

Claims (7)

[Claims] 1. In an impeller of a double-suction type forward multi-blade centrifugal fan comprising a pair of end rings 1, 2, a plurality of blades 3 and a center disk 4a, the end rings 1, 2 are made of metal and the blades 3 are The center blade 4a is composed of a metallic blade mounting portion 5 and a non-metallic blade portion 6 fixed to the blade mounting portion so as to cover the central blade 4a.
4 and a non-metal receiving portion 15 fixed to the disc substrate
An impeller of a multi-blade centrifugal blower, characterized in that the receiving portion 15 and the blade portion 6 are fixed to each other. 2. The impeller according to claim 1, wherein the blade mounting portion 5 has a small hole 8. 3. The impeller according to claim 1, wherein the blade mounting portion 5 has a bead 7. 4. An impeller of a double suction type forward multi-blade centrifugal blower comprising a pair of end rings 1 and 2, a plurality of blades 3 and a center disk 4b, wherein the end rings 1 and 2 are made of metal, and the blade 3 is It is composed of a metallic blade mounting portion 5 and a non-metallic blade portion 6 fixed to the blade mounting portion so as to cover it, and a groove-shaped receiving portion 12 is formed on the outer peripheral portion of the metal center disk 4b. An impeller for a multi-blade centrifugal blower, characterized in that the groove-shaped receiving portion clamps and fixes the blade portion 6. 5. The impeller according to claim 4, wherein the blade mounting portion 5 has a small hole 8. 6. The impeller according to claim 4, wherein the blade mounting portion 5 has a bead 7. 7. The pair of end rings 1, 2 and the plurality of blade mounting plates 5 are made of one metal plate, claim 1, or claim 2, or claim 3, or claim 4. Or the impeller according to claim 5 or claim 6.