JPH0998918A - Vacuum cleaner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the efficiency of an electric air blower, i.e., the suction work done of a cleaner and at the same time, realize cost reduction and miniaturization/weight reduction by setting the coefficient of discharge and the specific rate to a specific range for the electric air blower incorporated in a vacuum cleaner. SOLUTION: A vacuum cleaner equipped with an electric air blower consisting of a motor and a centrifugal impeller in the main body of the vacuum cleaner, uses such an electric air blower that the coefficient of discharge ϕe sought by formula ϕe=Q/(60.π.D2 .b2 .u2 ) falls within the range of 0.03-0.05, and also the specific rate Ns sought by formula Ns=(N.Q<0.5> .H<-0.75> ) is set to the range of 140-180. In this case, Q is air capacity (m<3> /min), D is the configuration (m) of a centrifugal impeller, b2 is the exit width (m) of the centrifugal impeller, u2 is the convergence (m/min) of the outer periphery of the impeller, N is rotational frequency (r/min) and H is head (m). Power consumption in the maximum air capacity zone of the electric air blower should preferably be about 1K(k).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum cleaner using an electric blower having a centrifugal impeller, and more particularly to a vacuum cleaner suitable for reducing the size and weight and increasing the output.

[0002]

2. Description of the Related Art As a conventional vacuum cleaner, there is one disclosed in JP-A-55-87894.
The aerodynamic characteristics of this electric vacuum cleaner are shown in FIG. 2, and the smaller the amount of intake air on the horizontal axis, the smaller the load on the commutator motor and the lower the current value, that is, the power consumption. On the other hand, the suction power represented by (amount of suction air x degree of vacuum) in the figure also decreases. In addition, although the suction air volume has increased with the recent enlargement of vacuum cleaners, the suction work rate decreases even in the maximum air volume range, and in terms of power consumption, it depends on the blower efficiency and the motor efficiency. There is an urgent need to improve the suction work rate.

[0003]

In the prior art as described above, in order to improve the efficiency of one blower, it is possible to prevent leakage caused by a high pressure difference in each part, improve airtight performance, and reduce ventilation resistance. For that purpose, a seal member is provided, the dimensional accuracy of parts is improved,
Alternatively, measures have been taken against the cost reduction and downsizing, such as securing a large ventilation area.

In addition, in order to improve the efficiency of the other motor, the winding diameter is increased to reduce copper loss, and high-grade silicon steel sheet with less iron loss is used for the iron core material. There is a certain response. Further, as the efficiency of the electric blower is improved, the manufacturing cost is increased, the weight is increased, and the vacuum cleaner becomes heavier, and it is also a problem that it is heavy and difficult to operate for a person who uses it, particularly an old man or a woman. .

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an electric vacuum cleaner which improves the efficiency of an electric blower, that is, the suction work rate of a vacuum cleaner, which leads to cost reduction and size and weight reduction.

[0006]

An object of the present invention is to provide an electric vacuum cleaner having an electric blower composed of an electric motor and a centrifugal impeller in a main body of the electric vacuum cleaner, wherein the electric blower is (equation 1) of the electric blower. Discharge flow coefficient φe calculated by the formula
Is in the range of 0.03 to 0.05 and the specific speed Ns obtained by the equation (2) of the electric blower is 14
It is achieved by setting the range from 0 to 180.

Φe = Q / (60 · π · D ₂ · b ₂ · u ₂ ) (Equation 1) Ns = (N · Q ^0.5 · H ^−0.75 ) ( ^Equation 2) However, Q: air volume (m ³ / min), D _2: the outer diameter of the centrifugal impeller (m), b _2: the outlet width of the centrifugal impeller (m), u _2: circumferential speed of the impeller periphery (m / min) N: rotational speed (r / min), H: head (m), and power consumption in the maximum air volume range of the electric blower is preferably about 1 Kw, and further, the centrifugal impeller has an impeller outer peripheral outlet width b ₂ and an impeller outside. The ratio with the diameter D ₂ is
It is set in the range of 0.085 to 0.133, or the area S ₁ of an imaginary ring connecting the tips of the blades of the centrifugal impeller on the center side and the inlet area S _{0 of the} centrifugal impeller. It is preferable that the ratio S ₁ / S ₀ of the above is set in the range of _1.0 to 1.4.

On the other hand, another feature of the present invention is that the ratio S ₁ / S ₀ of the blade inlet area S ₁ of a virtual ring connecting the tips on the center side of the blade to the inlet area S ₀ of the centrifugal impeller. 1.0 to 1.
Centrifugal impeller set in the range of 4 and 40
The electric vacuum cleaner includes an electric blower including an electric motor that rotates at a rotation speed of 000 to 50,000 (r / min). ADVANTAGE OF THE INVENTION According to this invention, the vacuum cleaner suitable for size reduction, weight reduction, and high output is provided.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. First, before describing the embodiments, the problems and the idea of the invention will be described in detail. As described above, in FIG. 2, the suction work rate is represented by air volume × vacuum degree, and shows the maximum value in the operating air volume determined by the characteristics of the blower and the ventilation resistance of the cleaner body, and the power consumption is 100%.
In the case of a 0W class general household vacuum cleaner, the air volume is 1.0
It becomes maximum at ~ 1.5 (m ³ / min). In the past, household electric vacuum cleaners have used electric motors with a power consumption of about 500 W, but the power consumption has increased year by year with the improvement of the suction work rate demanded by the market, and recently, the mainstream thereof is 1 kW.
It is becoming a class.

The suction power is one of the values showing the suction capacity of the vacuum cleaner, and it is important to improve this in terms of the function of the vacuum cleaner. Particularly in recent years, the surface to be cleaned has become diversified as represented by the floor surface, and since it is required to be able to quickly clean in any situation, a stronger suction force is required.

As expressed by "suction work rate = fan output-air loss", in order to improve the suction work rate, the fan output (aerodynamic output of the electric blower) is increased or the ventilation loss (vacuum cleaner) is increased. Airflow loss of the main body) must be reduced. However, it is difficult to significantly reduce the ventilation loss because the operability is deteriorated, for example, by increasing the diameter of the hose or enlarging the main body of the cleaner unless the shape of the cleaner is changed.

On the other hand, in order to increase the fan output, each item on the right side represented by “fan output = motor input (power consumption) × motor efficiency × blower efficiency” may be improved. With regard to the above, the 1000 W class has already become the mainstream, and considering the current trends such as energy saving, we think that it cannot be further increased as a household appliance. Therefore, in order to improve the fan output, it is necessary to improve the efficiency of the electric motor and the blower, that is, the efficiency of the electric blower. Electric blower efficiency is the aerodynamic fan output
(W) divided by the motor input (W).

Therefore, conventionally, the efficiency of the electric motor and the blower are emphasized and optimized, respectively, and the outer diameter of the centrifugal impeller is set to about 105 to 115 mm and the outlet width of the centrifugal impeller is set to 7 to.
About 8.5 mm, the number of revolutions is set to 30,000 to 35,000 revolutions per minute, and the air volume is 1.0 to 1.5 (m ³ / min),
It has reached 45-48%.

Conventionally, when the value shown here is converted into a discharge flow coefficient which is a dimensionless number of the flow rate through the impeller, 0.03 is obtained.
The range is up to 0.05, and the maximum N is about 130 when the amount N (rotation speed) related to the impeller and the Ns (specific speed) with respect to the impeller diameter (D ₂ ) are obtained.

Discharge flow coefficient φ of centrifugal blower of fluid machine
e and the specific speed Ns are defined by the following equations.

Φe = Q / (60 · π · D ₂ · b ₂ · u ₂ ) (Equation 1) Ns = (N · Q ^0.5 · H ^−0.75 ) ( ^Equation 2) where Q: air volume (m ³ / min), D ₂ : Outer diameter of centrifugal impeller
(m), b _2: the outlet width of the centrifugal impeller (m), u _2: circumferential speed of the impeller periphery (m / min) N: rotational speed (r / min), H: Head (m) H = Pin / Γ, Pin: Suction static pressure (mmAq), γ: Specific weight (kgf
/ m ³ ).

The idea of the invention for solving the above problems will be described. First, FIG. 3 shows the result of calculating the efficiency of the electric motor and the blower with respect to the rotation speed, and the product of the efficiency of the electric blower. However, the characteristic curve in this figure is
Although it depends on the material and shape of the parts used, an example is shown in which the efficiency is obtained under the conventional configuration conditions.

According to this, in general, the motor efficiency tends to decrease as the number of revolutions increases, and the bearing loss and friction loss called mechanical loss increase. On the other hand, the blower efficiency in the case of the centrifugal fan tends to be improved as shown in FIG. This reduces the outer diameter in order to match the load characteristics of the fan as the number of rotations increases, but this reduces the disk friction loss of the fan and improves the efficiency of the blower.

Then, looking at the efficiency of the electric blower, which is the product of these, the peak appears at around 45,000 revolutions per minute and decreases before and after, but the efficiency is 50% in the region of about 40,000 to 50,000 revolutions per minute. Is over.

Therefore, in order to obtain the maximum electric blower efficiency, that is, the maximum suction work rate, a high efficiency can be obtained by setting the rotation speed to 40,000 to 50,000 (r / min).

Next, when considering the speed reduction of the centrifugal impeller to reduce the disk friction loss and the required output characteristics, the specific speed with respect to the rotational speed, the impeller outer peripheral outlet width, and the impeller outer diameter. The relationship of the ratio with is shown in FIG. As shown in the figure, the suitability specification for obtaining the maximum efficiency as a combined electric blower is that the specific speed (Ns = (N · Q ^0.5 · H
^-0.75 )) is in the range of 140 to 180, and the ratio between the impeller outer circumference outlet width and the impeller outer diameter is 0.08.
The range is from 5 to 0.133.

With the above settings, the maximum efficiency of the electric blower can be obtained, and the suction power of the electric vacuum cleaner can be improved. Further, since the outer diameter of the impeller is reduced and the electric blower is downsized, the cleaner main body can be reduced in size and weight, and handleability and operability can be improved.

Embodiments according to the present invention will be described below with reference to the drawings. First, the drawings will be described. FIG.
FIG. 1 is a vertical sectional view of an electric blower used in an electric vacuum cleaner according to an embodiment of the present invention. FIG. 2 is an aerodynamic characteristic diagram of the electric vacuum cleaner. FIG. 3 is a diagram showing the electric blower efficiency with respect to the rotational speed, and FIG. 4 is a diagram showing the specific speed with respect to the rotational speed and the ratio of the impeller outer peripheral outlet width to the impeller outer diameter. FIG.
FIG. 6 is a diagram showing a comparison between the present invention and a conventional aerodynamic characteristic of an electric blower. FIG. 6 is an external perspective view of an electric vacuum cleaner according to an embodiment of the present invention. FIG. 7 is a vertical cross-sectional side view of a cleaner body in the electric vacuum cleaner of FIG. FIG. 8 is a vertical cross-sectional side view of the centrifugal impeller according to the embodiment of the present invention.

As shown in FIG. 6, the electric vacuum cleaner includes an electric vacuum cleaner body 20 having a built-in electric blower and a dust collecting filter.
1, an infrared ray receiving portion 202 for remote operation is installed, and a hose hand portion 204 provided at the tip of a hose 203 rotatably connected to the vacuum cleaner body 201.
Further, a suction port 206 is attached via an extension tube 205. The hose hand section 204 is provided with a switch operation section 207 for controlling the electric blower in the vacuum cleaner main body 201.
And infrared emitting units 208 and 209 for transmitting control signals in the form of infrared signals to the infrared receiving unit 202.

Further, as shown in FIG. 7, the vacuum cleaner main body 201 has an outer shell composed of a lower case 301, an upper case 302 and a dust collecting lid 303. A suction port 304 is formed in the dust collecting lid 303, and the suction port 304 is provided inside the suction port 304.
A dust collection chamber 306 is formed for accommodating a dust collection bag 305 to be joined to the airbag. Behind the dust collecting chamber 306, the lower case 30
1 and the upper case 302 are followed by an electric blower chamber 307, and an electric blower 308 is housed in the electric blower chamber 307. The intake side of the electric blower 308 communicates with the dust collection chamber 306 via the auxiliary filter 309.
The exhaust side of the electric blower 308 is opened to the outside from an exhaust port 310 via an exhaust chamber and an exhaust filter.

Next, the electric blower 308 will be described in detail with reference to FIG. The electric blower 308 is roughly divided into a blower 1 and an electric motor 2. The blower 1 includes a centrifugal impeller 12, a fan casing 13 that houses the centrifugal impeller 12 from both sides, and a diffuser 10. The electric motor 2 includes a case including a housing 3 and an end bracket 9, a rotor 5 having a rotating shaft 4 housed in the case, and a stator 7 around which a stator coil 6 is wound. The housing 3 is formed in a deep cup shape having a narrow flange portion 3a at its open end, and a bearing holding portion 3b formed at the center of the end face portion thereof is provided with a bearing 8a for pivotally supporting one end of the rotary shaft 4. To be Further, the exhaust port 3 is provided on the outer peripheral portion of the housing 3 on the end face side.
c is formed. An end bracket 9 is coupled to the open end side of the housing 3, and the electric motor 2 and the blower 1 are connected via the end bracket 9.

The end bracket 9 is formed into a shallow cup shape by an end surface portion having a bearing holding portion 9a formed in the center thereof and a cylindrical outer peripheral portion provided with a wide flange portion 9b at its open end. An intake port 9c for introducing the air from the blower 1 into the electric motor 2 is formed in the. The bearing holding portion 9a is provided with a bearing 8b that supports the other end of the rotating shaft 4.

On the other hand, on the outside of the end bracket 9, a diffuser 10 connected to the intake port 9c is arranged.
On the upstream side, a centrifugal impeller 12 fixed to an end of the rotating shaft 4 by a nut 11 is provided. Then, the diffuser 10 and the centrifugal impeller 12 have the end bracket 9
The fan casing 13 is press-fitted and fixed to the outer periphery of the collar portion 9b so as to be hermetically connected.

The suction port 13 is located at the center of the fan casing 13, that is, at the suction port 13b located near the axis.
An airflow guide 13a is provided for guiding the air flowing from upstream to downstream of b to be smoothly sucked into the centrifugal impeller 12. The air flow guide 13a is formed so that its cross-sectional shape is an arc shape, and a seal member 14 is provided inside the arc so as to slide in contact with an inlet formed at the center of the side plate of the centrifugal impeller 12, and suction is performed. The mouth is kept airtight.

The airflow guide 13a is generated as the size of the electric vacuum cleaner increases and the air volume increases, and the auxiliary filter 309 located upstream of the suction port 13b of the centrifugal impeller 12 as shown in FIG. Reduces turbulence and separation of the flow due to the influence of a protective guard (not shown), etc.
This is to avoid a decrease in suction power. The diffuser 10 is formed on the outer peripheral side extension of the centrifugal impeller 12.
The return guide 1 includes seven diffuser blades 10a and a return guide 10b formed on the back side thereof.
0b is the end bracket 9 together with the air flow to the intake port 9
Form a return guide passage leading to c.

Next, the flow of air in the electric blower 308 will be described. When the motor 2 is driven to rotate the centrifugal impeller 12, air flows into the fan casing 13 from the suction port 13b. At this time, the airflow guide 13a rectifies the airflow flowing into the centrifugal impeller 12. The airflow discharged from the centrifugal impeller 12 passes between the diuser blades 10a, and is turned by 180 degrees in an annular clearance between the outer circumference of the diffuser 10 and the inner circumference of the fan casing 13, and further, the return guide 10b. After being passed through, the gas is introduced into the housing 3 through the intake port 9c. The air introduced into the housing 3 cools the rotor 5 and also passes through the air passage formed between the stator 7 and the inner surface of the housing 3, cools the stator coil 6 and exhausts the exhaust port 3c.
Is discharged to the outside.

FIG. 8 shows the shape of the centrifugal impeller 12 in detail. The centrifugal impeller 12 is configured by arranging six blades 17 radially between a side plate 18 and a main plate 19. Claws for connecting to the side plate 18 and the main plate 19 are formed on both sides of each wing 17, and the side plates 18 and the main plate 19 are connected to each other by fitting the claws into the square holes formed in the square holes. To be done. The inlet 18a opening at the center of the side plate 18 is rounded up so as to be in sliding contact with the seal member 14 provided at the suction port 13b formed by the airflow guide 13a.
Formed by. In order to improve the efficiency in such a centrifugal impeller 12, it is important that the suction air flows smoothly without loss, which will be described later.

Details of the embodiment of the electric vacuum cleaner using the electric blower having the above-mentioned structure will be described with reference to FIGS.
Go back and explain. First, FIG. 3 shows the calculation results of the efficiency of the electric motor 2 with respect to the rotation speed, the efficiency of the blower 1, and the efficiency of the electric blower 308, which is the product thereof, in this example. As shown in FIG. 3, it can be seen that the efficiency of the electric blower, which is the product of the electric motor efficiency and the blower efficiency, peaks at around 45,000 revolutions per minute and exceeds 50% in the region of about 40,000 to 50,000 revolutions per minute. Therefore,
In order to obtain the maximum electric blower efficiency, that is, the maximum suction work rate, the rotation speed is 40,000 to 50,000.
It turns out that it should be set to revolutions per minute.

Further, in consideration of the diameter reduction and the required output characteristics for reducing the disc friction loss of the centrifugal impeller 12,
As an appropriate outer diameter, as shown in FIG.
It was found that the maximum efficiency was exhibited at 00 mm. Therefore, from the above, it can be said that the appropriate specifications for obtaining the maximum efficiency as the combined electric blower are the outer diameter of the centrifugal impeller 12 of 80 to 100 mm at 40,000 to 50,000 rpm. Therefore, the outer diameter of the impeller can be reduced,
As a result, the vacuum cleaner body can be made compact and lightweight. Further, the weight reduction makes it easier to carry and the handling and operability can be improved.

FIG. 4 shows the relationship between the ratio of the specific speed to the rotational speed, the impeller outer peripheral outlet width, and the impeller outer diameter based on the above results. Appropriate specifications 40000-5
Specific speed of 0000 revolutions per minute (Ns = (N ・ Q ^0.5・ H
^-0.75 )) is in the range of 140 to 180, and the ratio of the impeller outer peripheral exit width to the impeller outer diameter is then in the range of 0.085 to 0.133. With the above settings, the discharge flow coefficient of the electric blower (φe = Q / (60 ・ π ・ D ₂・ b ₂
・ In the range of u ₂ )) from 0.03 to 0.05, it is possible to achieve the efficiency of the electric blower of 50% or more.

On the other hand, as the centrifugal impeller 12 is rotated at 40,000 to 50,000 revolutions per minute and the outer diameter of the impeller is reduced to 80 to 100 mm, as described above, as shown in FIG.
It is necessary to optimize the inlet area ratio of the impeller as shown in. Then, as a result of the examination, the side plate 1 on the suction side of the centrifugal impeller 12
Inlet area S ₀ when 8 diameter of the inlet 18a of was D ₀
(= ΠD ₀ ^2/4) and the blade inlet area _{S 1 (= π · D 1} · b wing center side diameter of the virtual circle ring connecting the tip 17a (the blade inlet diameter) dimension was D ₁ of the respective wings 17 Regarding the inlet area ratio S ₁ / S ₀ with ₁ ), it has been found that the range of 1.0 to 1.4 is preferable.

That is, when the inlet area ratio S ₁ / S ₀ is as large as 1.4 or more, the blade inlet area S ₁ becomes excessive with respect to the inlet area S ₀ , and the air sucked from the inlet is The flow is from the central part of the centrifugal impeller 12 to the outer peripheral part,
Since the deceleration in the flow path sharply increases when flowing to the blade center side tip 17a on the center side of the blade 17, the flow is separated,
Turbulence occurs, noise becomes high, loss in the impeller increases, and efficiency decreases.

On the other hand, when the inlet area ratio S ₁ / S ₀ is as small as 1.0 or less, the blade inlet area S ₁ becomes too small with respect to the inlet area S ₀ , and the flow of air sucked from the inlet is small. Is
When flowing from the central part of the centrifugal impeller 12 toward the outer peripheral part to the blade center side tip 17a on the center side of the blade 17, it becomes an accelerated flow and pushes the air forcefully, so that friction loss and loss due to collision increase. It was found that the efficiency decreased. For reference, the conventional inlet area ratio S ₁ / S
₀ is the range of 1.58 to 1.63, and the inlet area ratio in the range as in the present invention is not adopted as the electric blower of the vacuum cleaner. In other words, the inlet area ratio S ₁ / S ₀
40 centrifuge impeller set to 1.0 to 1.4
If it is an electric vacuum cleaner equipped with an electric blower consisting of an electric motor that rotates at a rotation speed of 000 to 50,000 (r / min),
It can be said that the electric blower efficiency of 50% or more is achieved, and the electric vacuum cleaner can be made smaller and lighter and have higher output.

Next, the experimental results of the vacuum cleaner of the embodiment according to the present invention are shown in FIG. 5 in comparison with the conventional product. The figure shows the aerodynamic performance of an electric blower, in which the horizontal axis shows the discharge flow coefficient, and the vertical axis shows the pressure coefficient and the electric blower efficiency and specific speed. The centrifugal impeller of this embodiment has an outer diameter dimension D ₂ =
φ95 mm, outer peripheral outlet width b ₂ = 8.1 mm, blade inlet diameter dimension D ₁ = φ36.7 mm, and the number of blades 17 is 6.
The ratio of the impeller outer peripheral exit width b ₂ to the impeller outer diameter D ₂ is 0.08.
5 and the inlet area ratio S ₁ / S ₀ is 1.2. The conventional centrifugal impeller has an outer diameter dimension D ₂ = φ110 mm, an outer circumference outlet width b ₂ = 7.0 mm, and a blade inlet diameter dimension D ₁ = φ42.5 m.
The number of m and wings 17 is 6. The ratio of the impeller outer peripheral outlet width to the impeller outer diameter is 0.064, and the inlet area ratio is 1.
58. Further, the power consumption in this embodiment is 100
It is 0 W, and the operating air volume showing the maximum suction power is about 1.
4 (m ³ / min), which is 1.0 to 1.5 (m ³ / m ³ of the air volume range of a general household vacuum cleaner with a power consumption of 1000 W class.
min) is applicable. The discharge flow coefficient is about 0.04.
It will be around 5. The specific speed at this point is about 1 of the conventional product.
From 35 to 150 in the range of the present invention,
Along with this, the efficiency of the electric blower increased from 46% to 50%, 4%
Is also improving. Due to this improvement in efficiency, the fan output is increased and the suction power is improved by about 40 W. That is, it has been proved that the calculation results of the electric blower efficiency based on the appropriate specifications in FIGS. 3 and 4 described above are appropriate.

[0040]

According to the present invention, the efficiency of the electric blower is increased to 5
It is possible to achieve 0% or more, and it is possible to improve the suction power of the electric vacuum cleaner. Therefore, since the outer diameter of the impeller is reduced, the electric blower is downsized.

As a result, the main body of the electric vacuum cleaner can be made smaller and lighter, and the handling and operability can be improved.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of an electric blower used in an electric vacuum cleaner according to an embodiment of the present invention.

FIG. 2 is a diagram showing aerodynamic characteristics of the electric vacuum cleaner.

FIG. 3 is a diagram showing an electric blower efficiency with respect to a rotation speed.

FIG. 4 is a diagram showing a specific speed with respect to a rotation speed and a ratio of an impeller outer peripheral outlet width to an impeller outer diameter.

FIG. 5 is a diagram showing a comparison between the present invention and conventional aerodynamic characteristics of an electric blower.

FIG. 6 is an external perspective view of an electric vacuum cleaner according to an embodiment of the present invention.

FIG. 7 is a vertical cross-sectional side view of a cleaner body in the electric vacuum cleaner of FIG.

FIG. 8 is a vertical sectional side view of a centrifugal impeller according to an embodiment of the present invention.

[Explanation of symbols]

1 ... Blower, 2 ... Electric motor, 3 ... Housing, 3a, 9b
... Collar part, 3b, 9a ... Bearing holding part, 3c ... Exhaust port, 4 ...
Rotating shaft, 5 ... Rotor, 6 ... Stator coil, 7 ... Stator, 8a, 8b ... Bearing, 9 ... End bracket, 9c ...
Intake port, 10 ... Diffuser, 10a ... Diffuser blade, 10b ... Return guide, 11 ... Nut, 12 ... Centrifugal impeller, 13 ... Fan casing, 13a ... Airflow guide, 13b ... Suction port, 14 ... Seal member, 17 ... Tsubasa, 1
7a ... Tip of central side of blade, 18 ... Side plate, 18a ... Inlet, 18
b ... entrance part, 19 ... main plate, 201 ... vacuum cleaner body, 2
Reference numeral 02 ... Infrared light receiving portion, 203 ... Hose, 204 ... Hose proximal portion, 205 ... Extension tube, 206 ... Intake port, 207 ... Switch operating portion, 208, 209 ... Infrared emitting portion, 301 ...
Lower case, 302 ... Upper case, 303 ... Dust collection lid, 304
... Suction port, 305 ... Dust collection bag, 306 ... Dust collection chamber, 307
... electric blower room, 308 ... electric blower, 309 ... auxiliary filter, 310 ... exhaust port.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hisanori Toyoshima 1-1-1 Higashitaga-cho, Hitachi-shi, Ibaraki Hitachi Ltd. Electric Appliances Division (72) Inventor Takahiro Nakai 1-chome, Higashi-taga-cho, Hitachi-shi, Ibaraki No. 1 in the Electric Appliances Division, Hitachi, Ltd. (72) Inventor Kazuo Tahara, 7-1, 1-1, Omika-cho, Hitachi, Hitachi, Ibaraki (72) Incorporated, Hitachi Research Laboratory, Hitachi, Ltd. (72) Inventor, Takeshi Abe Hitachi, Ibaraki Prefecture 7-1 Mika-cho, Oita-shi, Hitachi, Ltd. Hitachi Research Laboratory

Claims (6)

[Claims] 1. An electric vacuum cleaner having an electric blower including an electric motor and a centrifugal impeller in a main body of the electric vacuum cleaner, wherein the electric blower has a discharge flow coefficient φe obtained by the formula (1) of the electric blower. , 0.03 to 0.05, and the specific speed Ns obtained by the equation (2) of the electric blower is set in the range of 140 to 180. Machine. φe = Q / (60 ・ π ・ D ₂・ b ₂・ u ₂ ) (Equation 1) Ns = (N ・ Q ^0.5・ H ^-0.75 ) ( ^Equation 2) However, Q: air volume (m ³ / min), D ₂ : Outer diameter of centrifugal impeller (m), b ₂ : Outlet width of centrifugal impeller (m), u ₂ : Peripheral speed of impeller outer circumference (m / min) N: Rotational speed (r / min), H: Head (m) 2. An electric vacuum cleaner main body is provided with an electric blower including an electric motor and a centrifugal impeller, and the electric power consumption of the electric blower in the maximum air volume range is about 1 Kw. The discharge flow coefficient φe obtained by the equation (1) of the blower is in the range of 0.03 to 0.05, and the specific speed Ns obtained by the equation (2) of the electric blower is 140. A vacuum cleaner characterized by being set in a range of 180. φe = Q / (60 ・ π ・ D ₂・ b ₂・ u ₂ ) (Equation 1) Ns = (N ・ Q ^0.5・ H ^-0.75 ) ( ^Equation 2) However, Q: air volume (m ³ / min), D ₂ : Outer diameter of centrifugal impeller (m), b ₂ : Outlet width of centrifugal impeller (m), u ₂ : Peripheral speed of impeller outer circumference (m / min) N: Rotational speed (r / min), H: Head (m) 3. The centrifugal impeller according to claim 1 or 2, wherein the ratio of the impeller outer peripheral outlet width b ₂ to the impeller outer diameter D ₂ is set in the range of 0.085 to 0.133. The electric vacuum cleaner characterized by having. 4. The centrifugal impeller according to claim 1, wherein the centrifugal impeller has a blade inlet area S ₁ of a virtual annular ring connecting the central ends of the blades and an inlet area S _{0 of the} centrifugal impeller. Ratio S
₁ / S ₀ is set in the range of 1.0 to 1.4. 5. A ratio S ₁ / S ₀ between a blade inlet area S ₁ and an inlet area S _{0 of} a virtual ring connecting the tips on the center side of the blade is 1.0.
To 1.4, and an electric blower equipped with an electric blower including a centrifugal impeller and an electric motor for rotating the centrifugal impeller at a rotation speed of 40,000 to 50,000 (r / min). . 6. The fan casing for accommodating the centrifugal impeller according to claim 1, wherein the fan casing accommodates the centrifugal impeller in a suction port located near an axis of the fan casing from an upstream side of the suction port. An electric vacuum cleaner having an air flow guide for guiding air flowing downstream so that the air is smoothly sucked into the centrifugal impeller.