JPH09256994A - Centrifugal multiple blade type motor-driven blower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce noise without reducing strength, and prevent sticking of dust. SOLUTION: An annular main plate 3 is calked by a rivet 5 in a driving electric motor side in the flange part 4a of the boss 4 of an impeller 6A. In the main plate 3, a strip shaped grooves 3a, 3b, 3c fit to the projection part of a blade 1A is formed radially. The half side of the blade 1A is fit to those grooves 3a, 3b, 3c through the projection part, and then welding is carried out. The projection part is also formed on the other side of the blade 1A, the projection part of the blade 1A is fit to a groove 2a formed on the outer peripheral part of a side plate 2, welding is carried out, and then the side plate 2 is fixed. In the blade 1A, the joining side of the main plate 3 is formed on a trapezoidal lower bottom side, the blade 1A is joined forcibly, and a supporting member for supporting the side plate 2 is eliminated on a suction side so as to prevent generation of noise.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a centrifugal multi-blade electric blower.

[0002]

2. Description of the Related Art FIG. 10 is a partial vertical cross-sectional view showing an example of a conventional centrifugal multi-blade electric blower. However, a partial enlarged view of this FIG. Is shown in FIG. 11, and the front view of this FIG. 11 is shown in FIG.

In FIGS. 10, 11 and 12, in a side view (not shown), the left end surface of the lower end of the spiral casing 15 is
The base 15a is fixed by welding, and on the right side surface of the casing 15, a substantially annular guide plate 16 is attached to the circular opening from the right side, and is fixed by a plurality of bolts 19A.

The drive motor 10 is mounted on the base 15a and is fixed to the base 15a with bolts 19B. At the tapered shaft end protruding to the right of this drive motor 10,
The center of the boss 24 is press-fitted through the key 12, and the washer with claw 13
And is fastened via the lock nut 14.

An annular main plate 23 constituting the impeller 11 is inserted from the left side into a stepped portion formed on the left side surface of the outer periphery of the boss 24, and is caulked with a plurality of rivets 18A. On the outer peripheral side of the right side surface of the main plate 23 in FIG. 10, a blade 17 described later in FIGS. 13, 14 and 15 is continuously arranged in a cylindrical shape, and is caulked to the main plate 23 with two rivets 18B. There is.

In the side view (not shown), an annular side plate 22 is attached to the right end surface of the blade 17 in FIG. 10, and the right end of each blade 17 described above is caulked to the side plate 22 with a rivet 18B.

Further, as shown in FIG. 12, fixing bolts 26 having a large head portion are screwed onto the outer periphery of the shaft portion of the boss 24 at 90 ° intervals, and the fixing bolts 26 are axially attached to the head portion of each fixing bolt 26. Since it is formed in the direction orthogonal to, the male screw portion of one side of the stee 25, which is manufactured from a round bar, is screwed into the screw hole, fixed with a nut, and then cut flat.

The other end of the stee 25 is bent as shown in FIGS. 10 and 11, and further formed into a flat plate by forging, and together with the blade 17 mentioned above, a rivet 18 is attached to the side plate 22.
It is crimped at B.

FIG. 13 shows the main plate shown in FIGS. 10, 11 and 12.
23 is a partially enlarged detailed view showing the caulked portion of blade 23 and blade 17,
14 is a front view of FIG. 13 including a caulked portion with the side plate 22, FIG. 15 (a) is a left side enlarged view of FIG. 14 (however, the main plate 23 is omitted), FIG. 15 (b) 14 is an enlarged view of the right side surface of FIG. 14 (the side plate 22 is also omitted).

As shown in FIGS. 12 and 13, 14 and 15,
Each blade 17 has an end on both sides of this blade 17 and an impeller.
The caulking is performed by inclining the outer peripheral side by a predetermined angle α in the counterclockwise rotation direction in FIG.

As shown in FIG. 15 (b), the blade 17 is pressed into a gutter shape with a predetermined radius r and an angle β, and both ends are bent inward at right angles to form a fixed portion. Further, a pair of caulking holes 17c are formed in the fixing portions 17a at both ends, and a V-shaped groove 17b for facilitating the above-described trough-shaped bending is formed in the center portion in advance in the planing process. Has been done.

In the centrifugal multi-blade electric blower configured as described above, the impeller 11 is driven by the driving electric motor 10.
When rotating in the counterclockwise direction at 12, the air inside the impeller 11 is exhausted by the blades 17 from a discharge port (not shown) provided in the casing 15 to a duct (not shown).

Outside air flows from the guide plate 16 of the casing 15 into the inside of the impeller 11 which has a negative pressure.
The air is continuously blown to the discharge port by each rotating blade 17.

By the way, when the centrifugal multi-blade electric blower is mounted on a railroad vehicle, the electric power supplied to the driving electric motor 10 is supplied from the overhead line installed on the railroad track through the pantograph of the vehicle to the front. It is supplied to the main transformer of the vehicle, stepped down by this main transformer, and then supplied to this centrifugal multi-blade electric blower.

Electric power is supplied to the overhead line from each substation installed in each power feeding section, and when the vehicle passes through the section where the power supply system is switched, the power supply is interrupted for 0.25 to 0.30 seconds. .

Therefore, the centrifugal multi-blade electric blower is stopped and restarted for each section, so that the driving electric motor is
In the case where the three-phase induction motor is adopted as 10, the excessive torque of several tens of times the torque during the rated operation is generated at each restart, and further increases in the case of the single-phase induction motor.
Therefore, in order to deal with this excessive torque, the above-mentioned four steers 20 are incorporated on the suction side.

[0017]

However, in the centrifugal multi-blade electric blower configured as described above, not only noise is generated by the stee 25 which rotates in a direction orthogonal to the flow of the intake air, but also the noise is generated. Due to the rotating stee 25, the sucked cooling air may become turbulent and pulsate, and the suction efficiency and the blowing efficiency may be reduced.

Therefore, a method of increasing the outer shape of the impeller 11 is conceivable, but then the outer shape and weight of the casing 15 also increase, which makes it impossible to store the impeller 11 in a limited space under the vehicle, and also the drive motor 10 You have to increase the capacity,
Noise also increases.

Further, FIG. 13 showing an enlarged view of the mounting portion of the blade 17 shown in FIGS. 10, 11 and 12 and FIG. 14 showing a front view of FIG. 13 and FIG. 15 showing a side view of the blade 17. As shown, a blade with a trough shape and mounting parts formed on both ends
The inside of both ends of 17 becomes a turbulent flow part of the cooling air, and becomes an adhering part of the dust X shown by diagonal lines, which may cause the impeller to lose its balance.

Then, the rotation of the impeller causes not only vibration but also maintenance and inspection work for removing the dust X increases. Therefore, an object of the present invention is to provide a centrifugal multi-blade electric blower capable of reducing noise and preventing dust from adhering without lowering the strength.

[0021]

A centrifugal multiblade electric blower according to the invention described in claim 1 has an annular main plate fixed to a side surface of a boss inserted into a shaft end of the electric motor, and one side of the main plate. And a blade arranged in a cylindrical shape coaxially with the axis of the electric motor, and an annular side plate that is provided on the other side of the blade so as to face the main plate and fixes the other side of the blade constitutes an impeller. The centrifugal multi-blade electric blower is characterized in that the blade has a trapezoidal shape in which the side plate side is the upper base, the main plate side is the lower base, and the hypotenuse of the cylindrical inner peripheral side is arcuate.

The centrifugal multi-blade electric blower according to a second aspect of the present invention is characterized in that an arcuate portion is formed on the outer peripheral side of the blades arranged in a tubular shape.

The centrifugal multi-blade electric blower according to a third aspect of the present invention is characterized in that the group of blades arranged in a tubular shape is composed of blades having different widths on the main plate side.

Further, in the centrifugal multi-blade electric blower of the invention described in claim 4, convex portions are formed on the upper bottom side and the lower bottom side of the blade, and the convex portions are fitted and fixed to the main plate and the side plates. It is characterized in that a through hole is formed.

Further, the centrifugal multi-blade electric blower of the invention described in claim 5 is characterized in that the inside of the main plate side of the blade is welded to the outer periphery of the boss.

By such means, in the invention described in claim 1, the turbulent flow on the suction side of the impeller is prevented and the joint portion of the blade fixed to the main plate is strengthened.

Further, in the invention according to claim 2,
Efficiently assists the air flowing into the impeller with the arcuate portion.

Further, in the invention described in claim 3,
The frequency of noise generated by the blade is divided into a plurality of frequencies.

Further, in the invention described in claim 4,
Firmly fix the upper and lower bottom sides of the blade to the main plate and side plates.

Further, in the invention described in claim 5, the fixing strength on the lower bottom side of the blade is further increased to change the frequency.

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a centrifugal multiblade electric blower of the present invention will be described below with reference to the drawings. FIG.
FIG. 2 is a partial cross-sectional view showing a first embodiment of a centrifugal multi-blade electric blower of the present invention, corresponding to FIG. 11 shown in the prior art and corresponding to claims 1, 2 and 4, and FIG. In the front view of FIG.
It is a figure similarly corresponding to FIG.

In FIGS. 1 and 2, a boss 4 having a smaller outer shape than the boss 24 shown in FIG. 10 is press-fitted into the shaft end portion of the drive motor (not shown). It is fixed.

An annular main plate 3 is attached to the driving motor side of the flange portion 4a formed on the outer periphery of the boss 4 as shown in FIG. 10 of the prior art, and as shown in FIG. It is crimped with rivets 5 on the book.

On the outer peripheral side of the main plate 3, FIG. 3, FIG. 4 and FIG.
The arc-shaped punching groove 3a, into which the arc-shaped convex portion projecting near the base end side of the blade 1A, which will be described later in detail, is inserted and welded is continuously formed over the entire circumference.

On the boss 4 side of these grooves 3a, a rectangular punching groove 3b into which a rectangular convex portion, which will be described later with reference to FIGS. However, a groove 3c is formed in the same manner as the groove 3a with a space left between the groove 3b and the boss side of the groove 3b. Has been done.

The grooves 3a, 3b, 3c of each of these groups have
1 has a substantially trapezoidal shape, and FIG. 2 has a substantially spoon-shaped blade 1A projecting from the proximal end side. The above-mentioned convex portions 1a, 1b, 1c shown in the enlarged view of FIG. 3 are inserted from the suction side. The outer plate is welded from the outside and finished with a grinder in a process after the side plate 2 is incorporated.

On the suction side of each blade 1A, a side plate 2 having substantially the same outer shape as the side plate 22 shown in FIGS. 10 and 11 is attached symmetrically to the main plate 3. A groove 2a shown in FIG. 1 having the same size as the arc-shaped groove 3a formed in the main plate 3 is continuously formed on the outer peripheral side surface of the side plate 2 over the entire circumference.

Similar to the main plate 3, the protrusions 1d shown in FIG. 3 projecting from the suction side of the blade 1A are inserted into the grooves 2a, welded from the outside and finished with a grinder. There is.

FIG. 3 shows the blade 1 shown in FIG.
FIG. 4A is a left side view of FIG. 3 and FIG. 4A is an enlarged detailed view of FIG. A (however, the direction is changed by 90 ° due to space limitations).
3B is a right side view of FIG. 3 (however, only the end face is shown). The two-dot chain line shown in FIGS. 1 and 3 indicates the range of the width L ₀ of the arcuate portion of the blade 1A described in FIG.

As shown in FIG. 3, the blade 1A is formed in a substantially trapezoidal shape, and the hypotenuse, which is the inner peripheral side and is arranged in a cylindrical shape in FIG. 1, is formed in an arc shape, and the bottom side on the left side of the trapezoid is formed. The width is curvilinearly wide.

In FIGS. 3, 4 and 5, the above-mentioned convex portions 1a, 1b, 1c are provided on the bottom side of each blade 1A.
However, as shown in FIG. 3, the height h2 is about 70% of the thickness of the main plate 3.
It is projected. On the other hand, the convex portion 1d projecting on the suction side of each blade 1A also has a height h1 of about 70% of the thickness of the side plate 2.
It is projected.

As shown in FIG. 4A, an arcuate portion 1e having an inner radius r ₀ and a length L ₀ is formed on the outer peripheral side and the upper side of the blade 1A, and the convex portion 1a is formed. A convex portion having lengths L ₁ and L ₂ is formed on a linear portion having a length L and continuing from the arcuate portion at L ₀ , which is indicated by an angle α ₀ of about 60 °.

Further, the angle α of the arcuate portion shown in FIGS. 4A and 4B is the same as the inclination angle α shown in FIG.
The outer peripheral side and the hypotenuse part of each blade 1A are chamfered in a slightly arcuate shape to reduce stress concentration and prevent turbulence of inflowing air.

In the centrifugal multi-blade electric blower having the impeller 6A constructed in this manner, the impeller is driven in the counterclockwise direction indicated by the arrow A in FIG. 2 to rotate together with the boss 4 and the main plate 3. The inner air is pushed out in a substantially tangential direction by the blade 1A and is sent from a discharge port to a duct (not shown). The air on the suction side of the impeller 6A is sucked into the inside by the sent air.

In this process, each blade 1A is
Each blade 1A receives the reaction force of the air sent into the duct through the discharge port, and further receives an excessive torque due to the restart every time it passes through the section.
The fixed side to the main plate 3, which is fixed to
Since the joint area with the main plate 3 is also wide, it can be firmly fixed to the main plate 3 and the bending stress applied to the blade 1A can be made substantially uniform over the entire area of the arc-shaped slope.

Therefore, not only is the stee that crosses the suction side shown in the prior art unnecessary, but the turbulent flow of the inflowing air due to this stee can be prevented, and the noise caused by this turbulent flow can be prevented. The fear can be eliminated.

Further, since the air guided from the inner peripheral portion of the blade 1A to the arc-shaped outer peripheral portion becomes a laminar flow by the trapezoidal blade, it is possible to prevent dust from adhering to the tip portion.
Furthermore, since the cutting surface of the end surface of the blade 1A on the suction side is chamfered in an arc shape, it is possible not only to prevent the vortex of the air sucked into the blade 1A from the outside but also to improve the long-term operation of this electric blower. It is also possible to prevent the occurrence of cracks from the hypotenuse portion of the blade 1A due to fatigue due to driving over a long period and vibration transmitted from the vehicle.

The inventors of the present invention have shown the conventional centrifugal multiblade electric blower shown in FIGS. 10, 11 and 12, and the centrifugal multiblade of the first embodiment of the present invention shown in FIGS. 1 and 2. Regarding electric blowers, JISB-8330 (blower test and inspection method) and JISB-8
A comparative test was conducted based on 346 (Method of measuring noise of blower and compressor). The blower's rating is 60m ³ / m
In, static pressure 70mmAq, drive motor is 3φ, 4P, 440
It is a V-60Hz 2.5kW induction motor.

[0049]

[Table 1] As shown in Table 1, the centrifugal multiblade electric blower of the present invention is
Compared with the conventional centrifugal multi-blade electric blower, less axial power is required, fan efficiency is improved by 4.2%, actual noise is low, and specific noise is 5.3 dB lower.

Further, as shown in the graph of FIG. 5, the static pressure characteristic with respect to the air volume has a peak in the curve P1 of the conventional product in the vicinity of 30 m ³ / min. While there is a stable region, in the product of the present invention,
As shown by the curve P2, the characteristic that it decreases with the increase of the air volume is shown, and there is no surging region, and the stable characteristic is shown.

Next, FIG. 6 is a partial cross-sectional view showing a second embodiment of the centrifugal multi-blade electric blower of the present invention, which corresponds to claim 3 and corresponds to FIG. 1, and FIG. In the front view of FIG.
FIG. 3 is a diagram corresponding to FIG. 2.

In FIGS. 6 and 7, the difference from FIGS. 1 and 2 is that the width of the bottom portion of the blade is partially adopted on the side of the main plate. It is the same as FIG. Therefore, the same elements as those in FIGS. 1 and 2 are designated by the same reference numerals and the description thereof will be omitted.

That is, in FIGS. 6 and 7, the blade fixed in a spiral shape between the main plate 3 and the side plate 2 has a width on the main plate 3 side with respect to the width between the blades 1A shown in FIG. Four narrow blades 1B are incorporated.

In the centrifugal multi-blade electric blower having the impeller 6B as described above, a part of the frequency of noise generated from the blade is changed by changing the natural frequency of the blade by changing the kind of the blade. The peak of synthesized noise can be suppressed, resonance can be avoided, and life can be extended.

Next, FIG. 8 is a partial cross-sectional view showing a third embodiment of the centrifugal multi-blade electric blower of the present invention, which corresponds to claim 5 and corresponds to FIGS. 1 and 6. 9 is a front view of FIG. 8, which is also a view corresponding to FIGS. 2 and 7.

In FIGS. 8 and 9, the points different from FIGS. 1, 2 and 6 and 7 are the same blades, and a blade having a wider width on the main plate side is partially adopted and welded to the boss portion. Therefore, the others are the same as those in FIGS. 6 and 7. Therefore, the same elements as those in FIGS. 6 and 7 are designated by the same reference numerals and the description thereof will be omitted.

That is, in FIGS. 8 and 9, the blade fixed in a spiral between the main plate 3 and the side plate 2 is one of the five blades 1A shown in FIGS. 6 and 7. The width on the side of the main plate 3 to be wider and the inner end surface
And is welded to this boss.

In the centrifugal multi-blade electric blower having the impeller 6C as described above, the frequency of noise is changed by changing the kind of blade and the kind of natural frequency of the blade, and the combined noise is generated. Can be suppressed, resonance can be avoided, and the life can be further extended.

The blades incorporated in the impellers shown in FIGS. 6, 7, 8 and 9 have two types of widths on the main plate 3 side, but there are three types of blades having different widths. Then, the types of noise frequencies may be increased to further reduce the peak of synthesized noise. Further, the plate thickness may be slightly changed to change the frequency of vibration and noise.

[0060]

As described above, according to the first aspect of the present invention,
An annular main plate fixed to the side surface of a boss that is inserted into the shaft end of the electric motor, a blade fixed to this main plate on one side and arranged coaxially with the axis of the electric motor in a tubular shape, and the other side of this blade. In a centrifugal multi-blade electric blower that constitutes an impeller with an annular side plate that is provided opposite to the main plate and that fixes the other side of the blade, the blade has a cylindrical inner side where the side plate side is the upper bottom and the main plate side is the lower bottom. A trapezoidal shape with an arcuate hypotenuse on the circumference side prevents turbulent flow on the suction side of the impeller and strengthens the joints of the blades fixed to the main plate, thus reducing noise without reducing strength. It is possible to obtain a centrifugal multi-blade electric blower capable of reducing the amount of dust and preventing the adhesion of dust.

According to the second aspect of the present invention, the arc-shaped portion is formed on the outer peripheral side of the blade arranged in a tubular shape, so that the air flowing into the impeller is efficiently promoted by the arc-shaped portion. Therefore, it is possible to obtain a centrifugal multi-blade electric blower capable of reducing noise and preventing dust from adhering without lowering the strength.

According to the third aspect of the present invention, the blades arranged in a cylindrical shape are composed of blades having different widths on the main plate side, so that the frequency of noise generated from the blades can be adjusted to a plurality of frequencies. Since it is divided into two parts, it is possible to obtain a centrifugal multi-blade electric blower capable of reducing noise and preventing dust from adhering without lowering the strength.

Further, according to the invention described in claim 4, the convex portions are formed on the upper bottom side and the lower bottom side of the blade, and the through holes through which the convex portions are fitted and fixed are formed on the main plate and the side plates. By firmly fixing the upper bottom side and the lower bottom side of the blade to the main plate and side plates, a centrifugal multi-blade electric blower that can reduce noise and prevent dust adhesion without reducing strength is obtained. be able to.

Further, according to the fifth aspect of the present invention,
By welding the inner side of the main plate side of the blade to the outer periphery of the boss, the fixing strength of the lower bottom side of the blade was further increased and the frequency was changed, so the noise was reduced and the dust adhered without decreasing the strength. A centrifugal multiblade electric blower that can be prevented can be obtained.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing a first embodiment of a centrifugal multiblade electric blower of the present invention, showing only an impeller.

FIG. 2 is a front view of FIG.

FIG. 3 is an enlarged detail view showing the blade incorporated into FIGS. 1 and 2.

4A is a left side view of FIG. 3, and FIG. 4B is a right side view of FIG.

FIG. 5 is a graph showing the action of the centrifugal multi-blade electric blower of the present invention.

FIG. 6 is a partial cross-sectional view showing a second embodiment of the centrifugal multi-blade electric blower of the present invention.

FIG. 7 is a front view of FIG.

FIG. 8 is a partial cross-sectional view showing a third embodiment of a centrifugal multi-blade electric blower of the present invention.

9 is a front view of FIG. 7. FIG.

FIG. 10 is a partial vertical cross-sectional view showing an example of a conventional centrifugal multi-blade electric blower.

FIG. 11 is a partially enlarged detailed view of FIG.

FIG. 12 is a front view of FIG. 11.

FIG. 13 is a partially enlarged detailed view of FIGS. 10, 11 and 12.

FIG. 14 is a front view of FIG. 13;

15A is a left side view of FIG. 14, and FIG. 15B is a right side view of FIG.

[Explanation of symbols]

1A, 1B, 1C ... Blades 1a, 1b, 1c, 1d
... Convex portion, 1e ... Arc-shaped portion, 2 ... Side plate, 3 ... Main plate, 3a, 3
b, 3c ... groove, 4 ... boss, 4a ... flange portion, 5 ... rivet.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Takashi Sato, Takashi Sato, Fuchu, Tokyo, 1st location, Toshiba Fuchu factory (72) Inventor, Tokusei Watanabe, 1F, Toshiba, Fuchu, Tokyo, Fuchu factory, Toshiba

Claims (5)

[Claims] 1. An annular main plate fixed to a side surface of a boss inserted into the shaft end of an electric motor, and a blade fixed on one side to the main plate and arranged in a cylindrical shape coaxial with the axis of the electric motor. In the centrifugal multi-blade electric blower that constitutes an impeller with an annular side plate that is provided on the other side of the blade so as to face the main plate and fixes the other side of the blade, the blade has an upper bottom on the side plate side. A centrifugal multi-blade electric blower having a trapezoidal shape in which the main plate side is a lower bottom, and the hypotenuse of the cylindrical inner peripheral side is an arc shape. 2. The centrifugal multi-blade electric blower according to claim 1, wherein an arcuate portion is formed on the outer peripheral side of the blades arranged in a tubular shape. 3. The centrifugal multi-blade electric blower according to claim 1, wherein the blade group arranged in the tubular shape is composed of blades having different widths on the main plate side. 4. A convex portion is formed on an upper bottom side and a lower bottom side of the blade, and a through hole for fitting and fixing the convex portion is formed on the main plate and the side plate. The centrifugal multi-blade electric blower according to any one of claims 1 to 3. 5. The centrifugal multi-blade electric blower according to claim 1, wherein the inner side of the main plate side of the blade is welded to the outer periphery of the boss.