JP3130089U - Centrifugal blower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a centrifugal blower capable of setting air volume and wind pressure in a wide range in one blower and thus easily exhibiting performance meeting the requirements.
Each blade in an impeller 1 is constituted by three portions in which an inlet blade 4, a main blade 5 and an outlet blade 6 are connected in this order. Each of the inlet wing 4 and the outlet wing 6 is attached to the impeller 1 so that the angle can be changed with respect to the main wing 5 so that the inlet angle β1 and the outlet angle β2 of the blade can be changed.
[Selection] Figure 1

Description

  The device according to the claims relates to a centrifugal blower, and particularly to a centrifugal blower capable of setting performance over a wide range.

  As is well known, a centrifugal blower is a device that rotates an impeller in which a plurality of blades are arranged in the circumferential direction and raises pressure by the action of centrifugal force thereby to send out gas such as air. In a centrifugal blower, generally, the air volume is proportional to the first power of the rotational speed and the third power of the shape ratio (size), and the wind pressure is proportional to the second power of the rotational speed and the second power of the shape ratio.

  In conventional centrifugal blowers, there are no elements that individually set the air volume and wind pressure, so in order to respond to the various demands of users regarding air volume and air pressure, a fan with a slightly different size is prepared from among them. It was necessary to select the optimal one. This is because there is no changeable range for performance such as air volume and pressure in one blower, so to obtain the required performance, it is only possible to change the number of rotations or the size of the blower. .

  If there is no blower that matches the required performance, it is common to select a blower with slightly higher performance and adjust the performance by reducing the flow rate with dampers at the inlet and outlet to meet the requirements. there were.

In addition, Patent Document 1 below describes a centrifugal blower in which the blade angle is determined to be different depending on the position, thereby improving the blowing efficiency.
JP 10-54390 A

  As described above, the method of adjusting the performance of the blower by reducing the flow rate with a damper or the like may significantly reduce the original efficiency of the blower. In addition, even if the centrifugal blower described in Patent Document 1 above is adopted, the shape (size, angle, etc.) of the blades and the impeller is constant in one blower, and the range in which the performance can be changed is small. Unless it is selected from many types of blowers of different sizes, it is difficult to obtain performance that meets the requirements.

  The invention according to the claims provides a centrifugal blower capable of setting a wide range of air volume and wind pressure in one blower, and thus easily exhibiting performance meeting the requirements.

  The centrifugal blower of the invention according to the claims is configured such that the inlet angle and the outlet angle of the blades in the impeller can be changed. The entrance angle and the exit angle are angles formed by the inlet side end portion and the outlet side end portion of the blade with respect to the tangential direction of the circumference corresponding to the rotation trajectory. The angles β1 and β2 illustrated in FIG. Respectively.

In the centrifugal fan, the inlet angle of the blade in the impeller significantly affects the air volume, and the outlet angle also significantly affects the wind pressure. Therefore, according to the centrifugal blower of the present invention in which each angle can be changed, the performance of the blower can be set around the air volume by changing the inlet angle of the blade, and the wind pressure can be changed by changing the outlet angle of the blade. The performance of the blower can be set at the center. The air blowing performance can be adjusted in a wide range without reducing the flow rate with an inlet or outlet damper. Therefore, according to the centrifugal blower of the invention, it is possible to appropriately exhibit the required performance without reducing the blowing efficiency.
In addition, the centrifugal blower of the invention refers to a configuration in which the entrance angle and the exit angle can be changed at least at the design stage and the trial operation stage before shipment. Therefore, even if the entrance angle and the exit angle are already made unchangeable in the commercial operation stage, they are not necessarily different from the centrifugal blower of the present invention.

  In particular, each blade in the impeller is composed of three parts in which the inlet wing, the main wing, and the outlet wing are connected in this order (from the inner peripheral part to the outer peripheral part). Is preferably attached to the impeller so that the angle can be changed with respect to the main wing.

  By doing so, it is possible to easily change each of the entrance angle and the exit angle of the blade as described above. Since it is not necessary to change the angle of the main wing, it is advantageous for firmly attaching the main portion of the blade to the impeller in a stable state.

In particular,
a) Fix the main wing to the main plate (hub) of the impeller, and set up a fixing pin (pin whose position is fixed) on the main plate at the positions of the inlet side (suction side) and outlet side of the main wing,
b) Attach the exit end of the inlet wing and the entrance end of the exit wing to each fixed pin so that the angle of the entrance wing and the exit wing can be changed around each fixed pin.
c) A movable pin (position changeable pin) is provided at each of the inlet end (including the vicinity of the end) of the inlet wing and the outlet end (including the vicinity of the end) of the outlet wing.
d) It is also preferable to attach an angle changing member that can change and fix the position of each movable pin of the inlet wing and the outlet wing (individually or collectively) to the main plate.

  In such a centrifugal blower, the angle of each of the inlet wing and the outlet wing can be smoothly changed on the inlet side and the outlet side of the fixed main wing. Each of the inlet wing and the outlet wing can be changed in angle as shown in b) around the fixed pin provided as in a) above, and the position of each movable pin shown in c) can be changed by the angle changing member in d). This is because the angle will naturally change and be maintained at that angle when fixed. There is an advantageous effect that the entrance angle and the exit angle can be easily changed by moving the movable pin, and the entrance angle and the exit angle can be firmly fixed by fixing the movable pin.

As the angle changing member of d) above for each of the inlet wing and the outlet wing,
-The position can be changed and fixed in the circumferential direction of the impeller along the main plate,
・ It has a plurality of slots extending in the radial direction (radial direction of the impeller)
・ All the movable pins of the inlet wing or the outlet wing are simultaneously positioned by inserting the above movable pins of all the inlet wings or all the outlet wings into the long holes.
---- It is better to install a variable ring (that is, an annular body whose circumferential position can be changed).

If the centrifugal blower is equipped with such an angle changing member, the angles of all the inlet blades or outlet blades can be changed and fixed at a time depending on the position of the variable ring. This can be explained as follows based on, for example, FIGS.
・ When the position of the variable ring is changed along the main plate in the circumferential direction of the impeller, the movable pins of all the inlet wings or all the outlet wings are displaced in the circumferential direction together with the variable ring while being inserted into the elongated holes. Also, it is displaced in the radial direction which is the length direction of the long hole. Thus, when the movable pins of all the inlet wings or all the outlet wings are displaced, the total number of the inlet wings or the outlet wings changes the angle smoothly.
・ When the variable ring is fixed, the movable pins of all inlet wings or all outlet wings are fixed in a position uniquely determined by the circumferential position of the slot and the distance between the fixed pin and movable pin of each wing. Thus, the angle is fixed for the total number of inlet blades or outlet blades.

  From this point, if the positional accuracy of the long hole in the variable ring is increased, the angle of the plurality of blades and the amount of change can be determined uniformly with high accuracy. The variable ring should be fixed to the main plate after determining the optimum position (position matching the required performance) at the design stage or trial operation stage, but once fixed, it should be attached so that the position can be changed. It's also good.

  In the centrifugal blower, the fixing pin protrudes to the outside of the main plate (the side without the blades), and a groove extending in the circumferential direction into which the protruding portion of the fixing pin is inserted into the variable ring. Or it is preferable to form a hole.

  In such a case, when the variable ring is along the main plate, the protruding portion of the fixing pin enters the groove or hole formed in the variable ring, so the variable ring when changing the position is provided on the main plate. It will be in the state which can be moved by being guided by the fixed pin. Therefore, the change in the circumferential position of the variable ring for changing the angle of the inlet blade or the outlet blade can be performed very easily and accurately, and the position can be prevented from shifting in the radial direction.

  According to the centrifugal blower of the device according to the claims, the air blowing performance can be adjusted in a wide range without lowering the air blowing efficiency, and the performance matching the user's request can be exhibited. This alleviates the need to prepare a large number of types of fans that are slightly different in size, and can reduce the manufacturing cost of the fans. The performance can also be improved without increasing the size of the blower.

  It is also possible to adopt a configuration having a variable ring so that the angle change of the inlet wing or the outlet wing that enables the adjustment of the performance as described above can be performed collectively. It is also possible to change the position of the variable ring very easily and accurately.

  Embodiments of the invention are introduced in FIGS. First, FIG. 1 is a diagram conceptually showing a main part of a centrifugal blower, in which FIG. 1 (A) is a longitudinal sectional view of an impeller 1 of the centrifugal blower, and FIG. 1 (B) is a B- in FIG. It is B sectional drawing. FIG. 2 is a diagram specifically showing the main part. FIG. 2A is a longitudinal sectional view of the impeller 1, and FIG. 2B is a sectional view taken along the line BB in FIG. 3 is a view showing a mechanism for changing the angle of the inlet blade 4 and the outlet blade 6 in the impeller 1, and FIG. 3 (A) is a view taken along the line III-III in FIG. 2 (A), and FIG. ) Is a detailed view showing a part of the inlet blade variable ring 11 in (A), and (C) is a detailed view showing a part of the outlet blade variable ring 12 in (A). FIG. 4 is a performance comparison diagram of the centrifugal fan as an example and the blade-fixed centrifugal fan as a comparative example.

  An impeller 1 shown in FIG. 1 and the like has a plurality of blades and side plates (shrouds) 3 attached to a main plate (hub) 2, and a boss portion 7 integrated with the main plate 2 is a motor or the like (not shown). By attaching and rotating to the shaft (same as above), air is sucked from the opening on the inner peripheral side, and the pressure is increased and sent out to the outer peripheral side. Although not shown, a diffuser, a vortex chamber, and a discharge pipe are assembled on the outer peripheral side of the impeller 1, and a centrifugal blower is configured by all of them.

  As shown in FIGS. 1 (A) and 1 (B), the impeller 1 of the centrifugal blower according to the invention has an inlet wing 4, a main wing 5, and an outlet wing 6 arranged in this order from the inner peripheral side in this order. Of the wings. Each of the inlet wing 4 and the outlet wing 6 can be changed in angle with respect to the main wing 5 so that the inlet angle β1 and the outlet angle β2 of each blade can be changed.

The configuration for changing the angle of the inlet wing 4 and the outlet wing 6 with respect to the main wing 5 is as shown in FIGS. That is, first, as shown in FIGS. 2 (A) and 2 (B),
a) While fixing the main wing 5 to the main plate 2 of the impeller 1 by welding or the like, fixing pins 4a and 6a are attached to the main plate 2 at the positions of the inlet side (suction side) and the outlet side of the main wing 5 respectively. Stand and fix. The fixing pins 4a and 6a pass through the main plate 2 at a right angle, and project an end portion on the outer side (side without blades).
b) By attaching the outlet side end portion of the inlet blade 4 and the inlet side end portion of the outlet blade 6 to the fixing pins 4a and 6a, respectively, the inlet blade 4 and the outlet blade 6 are centered on the fixing pins 4a and 6a, respectively. The angle can be changed.
c) Movable pins 4b and 6b perpendicular to the main plate 2 are attached to the inlet side end portion of the inlet wing 4 and the outlet side end portion of the outlet wing 6, respectively, and are projected to the outside of the main plate 2. If the position of the movable pin 4b or 6b is changed, the angle of each inlet blade 4 or outlet blade 6 can be changed.
d) The inlet blade variable ring 11 and the outlet blade variable ring 12 that can be fixed by changing the position in the circumferential direction of the impeller 1 along the main plate 2 are attached to the outside of the main plate 2. The inlet wing variable ring 11 is provided near the inner periphery of the main plate 2, while the outlet wing variable ring 12 is provided near the outer periphery of the main plate 2, and their attachment can be changed, for example, with the main plate 2. Each variable ring 11 or 12 may be sandwiched with a bolt or the like (not shown).

  The inlet wing variable ring 11 and the outlet wing variable ring 12 are attached as angle changing members that can collectively change and fix the positions of the movable pins 4b and 6b of the inlet wing 4 and the outlet wing 6. The structures of the variable rings 11 and 12 and their functions are as shown in FIGS.

  That is, the inlet wing variable ring 11 is provided with a plurality of elongated holes 11a extending in the radial direction, and the protruding ends of the movable pins 4b of all the inlet wings 4 are inserted into the elongated holes 11a. One outlet blade variable ring 12 is also provided with a plurality of elongated holes 12a extending in the radial direction, and the protruding ends of the movable pins 6b of all the outlet blades 6 are inserted therein. If the position of the variable ring 11 or 12 in the circumferential direction is changed, the movable pins 4b and 6b are displaced while moving in the radial direction in the long holes 11a and 12a as shown in FIGS. Thus, the angles of all the inlet blades 4 or the outlet blades 6 can be uniformly changed at the same time. If the variable ring 11 or 12 is fixed to the main plate 2, the angles of all the inlet blades 4 or the outlet blades 6 can be fixed simultaneously.

  As shown in each drawing of FIG. 3, grooves 11b and 12b are formed in each of the variable rings 11 and 12, and each of the variable rings 11 and 12 covers the ends of the fixing pins 4a and 6a protruding outside the main plate 2. I have to. If it does in this way, when changing the circumferential direction position of variable ring 11 * 12, there is no possibility that the position of variable ring 11 * 12 may be shifted in the radial direction accidentally.

また、出口角β２については、

で定めることができる。ただし、上の二式において、
Ｑ：送風機の風量 Ｐ：送風機の風圧
Ｎ：送風機の回転数 γ：気体密度
Ｄ１，Ｄ２：羽根の入口および出口の直径
ｂ１，ｂ２：羽根の入口および出口の幅
β１，β２：羽根の入口および出口の角度
ｋ１，ｋ２：羽根の直径・幅等に関する補正係数
である。 In the centrifugal blower incorporating the impeller 1 as described above, by changing the angles of the inlet blade 4 and the outlet blade 6 through the variable rings 11 and 12, that is, the inlet angle β1 and the outlet angle β2, the air volume and the wind pressure are widened. The range can be adjusted. The inlet angle β1 and the outlet angle β2 to be set in order to obtain the air volume / wind pressure required by the user or the like can be determined by the following formulas according to the researches of the inventors. That is, first, for the entrance angle β1,

For the exit angle β2,

Can be determined by However, in the above two formulas,
Q: Air flow rate of the blower P: Wind pressure of the blower N: Number of rotations of the blower γ: Gas density D1, D2: Diameters of the blade inlet and outlet b1, b2: Blade inlet and outlet widths β1, β2: Blade inlet and Outlet angle k1, k2: Correction coefficients relating to the diameter and width of the blades.

  Note that the inlet angle β1 and the outlet angle β2 determined in advance as described above are preferably adjusted again after actually measuring the air volume and the wind pressure by performing a trial run of the centrifugal fan.

FIG. 4 shows a conventional blower-fixed blower (comparative example) and the above-described blower as an embodiment of the present invention (those shown in FIGS. ) And the performance range are compared. The range of the solid line is the performance at 1000 to 1800 min ⁻¹ revolutions in a conventional blower with an entrance angle β1 = 25 ° and an exit angle β2 = 41.5 °. The range of the broken line is the performance range of the blower changed at the same rotational speed with the inlet angle β1 = 20 to 60 ° and the outlet angle β2 = 30 to 85 °. Increasing the inlet angle β1 increases the air volume, and increasing the outlet angle β2 increases the wind pressure. It can be seen from FIG. 4 that the fan according to the invention can obtain a wider performance range than the conventional one.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows notionally the principal part of the centrifugal blower which is one Embodiment of invention, Comprising: FIG. 1 (A) is a longitudinal cross-sectional view about the impeller 1 of a centrifugal blower, The same (B) is the same in (A). It is BB sectional drawing. It is a figure which shows the principal part of FIG. 1 concretely, Comprising: FIG. 2 (A) is a longitudinal cross-sectional view of the impeller 1, The same (B) is BB sectional drawing in the same (A). It is a figure which shows the mechanism of angle change of the entrance blade 4 and the exit blade 6 in the impeller 1, Comprising: FIG. 3 (A) is the III-III arrow line view in FIG. 2 (A), FIG. 4A is a detailed view showing a part of the inlet blade variable ring 11, and FIG. 4C is a detailed view showing a part of the outlet blade variable ring 12 of FIG. It is a performance comparison figure about the centrifugal blower as an Example and the blade fixed type centrifugal blower which is a comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Impeller 2 Main plate 3 Side plate 4 Inlet blade 5 Main wing 6 Outlet blade 4a, 6a Fixed pin 4b, 6b Movable pin 7 Boss 11 Inlet blade variable ring 12 Outlet blade variable ring 11a, 12a Long hole 11b, 12b Groove β1 Inlet angle β2 Exit corner

Claims (5)

  A centrifugal blower characterized in that an inlet angle and an outlet angle of a blade in an impeller can be changed.   Each blade in the impeller is composed of three parts in which the inlet wing, the main wing, and the outlet wing are connected in this order, and each of the inlet wing and the outlet wing is attached to the impeller so that the angle can be changed with respect to the main wing. The centrifugal blower according to claim 1, wherein the centrifugal blower is provided. The main wing is fixed to the main plate of the impeller, and a fixing pin is set up on the main plate at the position of each end of the main wing on the entry side and the exit side,
By attaching the exit side end portion of the entrance wing and the entrance side end portion of the exit wing to each fixing pin, the angle of the entrance wing and the exit wing can be changed around each fixing pin, respectively.
A movable pin is provided on each of the inlet end of the inlet wing and the outlet end of the outlet wing,
The centrifugal fan according to claim 2, wherein an angle changing member capable of changing and fixing the position of each movable pin of the inlet blade and the outlet blade is attached to the main plate. As the above angle changing member for each of the inlet wing and the outlet wing,
A variable ring that can be repositioned and fixed along the main plate in the circumferential direction of the impeller, and has a plurality of elongated holes extending in the radial direction, and all of the inlet blades or all of the outlet blades are placed in the elongated holes. The centrifugal blower according to claim 3, wherein the movable pin is inserted so as to simultaneously determine the positions of all the movable pins of the inlet wing or the outlet wing.   5. The variable ring according to claim 4, wherein the fixing ring protrudes outside the main plate, and the variable ring has a groove or a hole extending in a circumferential direction in which the protruding portion is inserted. Centrifugal blower.

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