JPH0686741A - Air turbine suction implement of vacuum cleaner - Google Patents

Abstract

PURPOSE:To decrease a noise, and to enlarge generated torque by allowing the center shaft of a nozzle and the split surface of an air turbine impeller to coincide with each other, and forming roughly a funnel shape of a socket of a swivel asymmetrically against the center shaft of a suction implement. CONSTITUTION:Suction air 32 comes into collision with a blade 4a of an air turbine impeller 4, and a speed difference to a discharge air current 9 after the collision works as a momentum and generates torque. By this torque, a rotary brush 13 is rotated through a shaft 10, a pulley 11, and a timing belt 12. The air current 9 after the collision passes through a gap between the impeller 4 and the bottom face of the lower case 2, while diffusing along a circular arc of a side wall 4d of the impeller 4, and is discharged to a socket 22 of a swivel 15. The greater part of the discharge air current 9 is sucked into an L-shaped joint 23, but a partial air current 9a diffused by the impeller 4 hits against a rear wall 19 of a turbine chamber 16 and a side wall 22b of the socket 22. However, it is sucked quickly into the L-shaped joint 23, since the rear wall 19 and the side wall 22b are streamline by a circular arc of a large curvature, a noise by the air current after the collision becomes low.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air turbine in a suction tool of an electric vacuum cleaner, and more particularly to a flow passage shape capable of suppressing collision noise of high-speed jet airflow in a turbine chamber.

[0002]

2. Description of the Related Art Due to the variety of lifestyle habits, the floor surface is a wide variety of floors, floors, tatami mats, and carpets. In order to deal with these problems, the suction tool of the electric vacuum cleaner uses an electric motor (motor) or an air turbine by aerodynamic force as a power source for driving the rotary brush for cleaning the carpet. In the former case, a power supply line must be provided in the hose, extension pipe, etc. that connects the cleaner body and the suction tool, and the suction tool has a built-in motor, which is heavy, has a large operating force, and is a burden to the user. ing. In the latter case, there is an increase in noise due to an increase in turbine speed in a no-load state such as when the suction tool is lifted.

[0003] Conventionally, as a suction tool mounted on an air turbine, there are those shown in, for example, Japanese Utility Model Laid-Open No. Sho 53-97568 and Japanese Patent Laid-Open No. Sho 63-194619. These suction tools utilize the suction airflow of the cleaner main body to reduce the suction area by a nozzle to turn the suction air into a high-speed jet airflow, and the impeller of the air turbine is rotated by the jet airflow. Therefore,
In order to secure this high-speed jet airflow, it is necessary to maintain the amount of suction air, so due to the sinking of the suction tool during carpet cleaning, etc., in order to obtain a structure in which the ventilation port is not blocked and a large rotational force of the turbine, A structure has been proposed in which plate bodies are provided on both sides of the turbine in close proximity.

However, these structures do not take into consideration the noise generated when the high-speed jet stream collides with the impeller and the peripheral wall of the turbine chamber.

[0005]

The air turbine of the vacuum cleaner suction tool requires a large torque (rotational force) because it requires a rotational force to compensate for the resistance of the carpet and the loss of the timing belt between the air turbine and the rotary brush. ) Is required, for example, a torque of 180 gf · cm is required at a rotation speed of 10,000 r / min. The torque of the air turbine is proportional to the product of [blowing volume] and [blowing velocity] of the nozzle. The torque is determined by the resistance coefficient of a resistor such as a carpet or tatami mat when the rotary brush rotates. The blown air volume is affected by the blower performance of the cleaner body, but in general, the microcomputer in the cleaner body has 1.2 to 1.5 m ³ so that the blower operates with an air volume that increases the suction work of the blower. It is controlled to / min. Therefore, in order for the air turbine to output the required torque at the [jet flow rate] of these nozzles, a high-speed jet airflow of which the [jet flow rate] of the nozzle hole reaches about 100 m / s is required.

[0006] The noise of the suction tool mounted on the air turbine includes jet noise from the nozzle, collision noise when the jet stream collides with the blade, and discharge flow from the impeller to the peripheral wall of the air turbine chamber and the wall surface of the rotary joint. There is a collision sound at the time of a collision, etc., and these influence each other, and the noise level is almost the same level. If the sound of collision with the wall surface is loud, the noise of the suction tool also becomes loud. To reduce the collision noise, it is sufficient to lower the jet air flow velocity of the nozzle, but the generated torque also becomes smaller, and there is a problem that the rotating force of the rotary brush loses the resistance of the carpet etc. and it will not rotate, so the required flow velocity. You have to make sure the jet stream is flowing. For these reasons, there is a drawback in that the noise of the suction tool is large in the conventional flow path that is constituted by the nozzle, the impeller, the turbine chamber, the receiving port of the rotary joint, and the like.

Therefore, the present invention has a torque necessary to rotate the rotary brush in order to eliminate the drawback of the high noise of the air turbine in the conventional vacuum cleaner suction tool, and reduces the airflow collision of the air turbine. To provide a suction device for the vacuum cleaner.

[0008]

According to the present invention, the blades of an impeller divided into a plurality of parts are arranged so that their pitches are offset from each other, and the divided surfaces are aligned with the central axes of the nozzles, and the center of the socket of the rotary joint is aligned. The axis and the center point on the inlet side of the nozzle are substantially aligned. Alternatively, the central axes of the nozzle, the split surface of the impeller, and the socket of the rotary joint are made to substantially coincide with each other. The receiving shape of the rotary joint is substantially a jogo shape, and the receiving side and the bearing side peripheral wall of the impeller of the turbine chamber are connected by a streamline arc. The gap between each of the upper and lower surfaces of the turbine chamber and the impeller is set appropriately.

[0009]

[Operation] The suction airflow squeezed by the nozzle is 1
A high-speed jet stream of about 00 m / s is generated, which collides with the divided blades of the impeller and decelerates. This deceleration amount is converted into torque generation and noise. A part of the airflow that collides with the impeller flows back to the nozzle side. The backflow airflow becomes a vortex in the gap between the impeller and the nozzle support plate to generate noise. Most of the decelerated jet airflow after the collision flows along the bottom surface side of the turbine chamber while being diffused in the axial direction of the impeller in combination with the rotating effect of the impeller. If the gap between the impeller and the bottom surface of the turbine chamber is small, the air flow will be forced into the air, and jet noise will be generated due to the increase in the flow velocity. Therefore, this gap is appropriately set so that the flow velocity of the airflow can be further reduced. By making the shape of the rear wall of the turbine chamber and the receiving shape of the rotary joint streamlined, the suction effect of the blower of the cleaner body and the high-speed airflow that collides with the impeller, even if they collide with them, It suppresses the generation of vortices and reduces the noise energy.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. 1 is a perspective view of an air-turbine-equipped suction tool according to the present invention, FIG. 2 is a plan view of FIG. 1 with the upper case removed, FIG. 3 is a cross-sectional view of FIG. 1, and FIG. 4 shows the relationship between the gap and noise. FIG. 5 is a plan view of the other embodiment with the upper case removed, as in FIG.

The suction tool body is composed of an upper case 1 and a lower case 2, and has a rotary brush 3, an air turbine impeller 4, a shutter opening / closing mechanism 5 and the like built therein. The high-speed jet airflow 8 narrowed down by the main nozzle 7 provided on the nozzle mounting plate 6 collides with the blade 4a of the impeller 4 which is divided into two parts, is decelerated to become the discharge airflow 9, and is discharged from the cleaner main body. It is sucked into a blower (not shown). The speed difference between the high-speed jet airflow 8 and the discharge airflow 9 becomes a rotational force, that is, a generated torque, and the power is transmitted to the shaft 10, the pulley 11, the timing belt 12, and the rotary brush 3.
The shaft 10 is supported by a bearing holder 14 containing a ball bearing bearing 13. At the rear of the suction tool body, there is a rotary joint 15 connected to a hose / extension pipe (not shown) connected to the cleaner body, and is sandwiched between the upper case 1 and the lower case 2 so as to be slidably rotatable. . Turbine room 1
Reference numeral 6 denotes the nozzle support plate 6 sandwiched between the upper case 1 and the lower case 2, and the left and right side walls 17, 1 of the upper case 1 and the lower case 2.
8 and the rear wall 19. Nozzle support plate 6
Has a main nozzle 7 and a bypass nozzle 20, both of which are circular or elliptical in shape. Main nozzle 7
Is used when there is a large load such as carpet, and bypass nozzle 2
Reference numeral 0 denotes a knob 5b of the shutter opening / closing mechanism 5 which is used with the main nozzle 7 by opening and closing it when the load on the tatami mat or wooden floor is light. The opening area of the bypass nozzle 20 is 100 mm ² and the main nozzle 7 is 250 mm ^2, which is set to about 1/3 of the main nozzle 7, but this is set according to the load condition of the floor surface and the application. The central axis of the main nozzle 7 is aligned with the dividing surface of the turbine impeller 4.

The lower end of the main nozzle 7 is arranged so as to substantially coincide with the outermost periphery of the impeller 4 on the bottom surface side of the lower case 2.
The bypass nozzle 20 is arranged so that the jet airflow 8 does not collide with the blade 4 a of the impeller 4. The air turbine impeller 4 is divided into two blades, a blade L4b and a blade R4c, and the respective blades 4a are offset from each other by an anti-pitch. In the case of 8 blades, the pitch is 22.5 °.
The inner / outer diameter ratio of the impeller 4 and the curvatures R on both sides are optimized. The impeller 4 is fastened with a push-on fix 21 so as to be integrated with the shaft 10. The shaft 10 is supported by a ball bearing bearing 13 held by a bearing holder 14 so that the shaft 10 can smoothly rotate. A pulley 11 for rotating the rotary brush 3 is fixed to the other end of the shaft 10 via a timing belt 12. The socket 22 of the rotary joint 15 is provided with protrusions 22a on both sides, which serve as the center of rotation. This receptacle 22 has L
A joint 23 of the shape is rotatably mounted. The shape of the receiving port 22 is substantially streamlined in the shape of a jogo. In other words, the center axis 24 of the suction port, that is, the center axis 24 of the upper case 1 and the lower case 2 and the central axis 25 of the connecting portion of the receiving port 22 of the rotary joint 15 and the L-shaped joint 23 are aligned. However, the impeller 4 of the socket 22
An axial center 27 of the side center 26 is substantially aligned with the inlet side center 7a of the main nozzle 7. That is, the substantially jogo shape is asymmetric with respect to the central axis 24 of the mouthpiece. The rear wall 19 of the turbine chamber 16 is formed as an extended shape of the receiving port 22 or an arc having a large curvature with the side wall 17. The gap between the impeller 4 of the turbine chamber 16 and the side wall 17 on the nozzle support plate 6 side and the bearing 13 side is approximately twice the length of the parallel portion 7b of the main nozzle 7. The gap with the upper case 1 may be several millimeters, but with the lower case 2, as with the nozzle support plate 6 side, several times the length of the parallel portion 7b of the main nozzle 7 is necessary, and the size is set to that dimension. Is configured. The opening / closing of the bypass nozzle 20 is performed by the shutter opening / closing mechanism 5.
Shutter 5a. The bypass nozzle 20 is opened when cleaning a relatively lightly loaded floor surface such as a tatami mat or a wooden floor. When cleaning a heavily loaded floor such as a carpet, the bypass nozzle 20 is closed by the shutter 5a of the shutter opening / closing mechanism 5.

An example of cleaning the floor of a carpet or the like having a heavy load with the above configuration will be described. The suction air 32 flowing into the rotary brush chamber 28 is narrowed down by the main nozzle 7, becomes a high-speed jet airflow 8, and collides with the blade 4 a of the air turbine impeller 4. Then, the speed difference with the discharge airflow 9 after the collision acts as a momentum, and a rotational force (torque) is generated. With this torque, the rotary brush 3 is rotated via the shaft 10, the pulley 11, and the timing belt 12. The jet airflow 9 after the collision is the impeller 4
While being diffused along the arc of the side wall 4d, the gas is discharged to the receiving port 22 of the rotary joint 15 through the gap 29 between the impeller 4 and the bottom surface of the lower case 2. Most of the discharge airflow 9 is sucked into the L-shaped joint 23, but a part of the airflow 9a diffused by the impeller 4 hits the rear wall 19 of the turbine chamber 16 and the side wall 22b of the receiving port 22. So that it can flow easily
Since it has a streamlined shape formed by an arc having a large curvature, it is quickly sucked into the L-shaped joint 23. Therefore, the generation of vortices due to the air flow after the collision is small, and the noise is reduced.

As will be described with reference to FIG. 4, the main nozzle 7 is shown on the horizontal axis.
Is an index with respect to the length L of the parallel portion 7a, and the vertical axis is a measured value of noise. Air turbine impeller 4 on the carpet floor
Shows the noise value at a rotation speed of 10,000 r / min. Curve A is an experiment on the relationship between the nozzle support plate 6 and the gap 30 of the impeller 4. When the gab exceeds about twice the parallel part 7a, the noise drops sharply, and there is almost no change even when the gab exceeds it. Therefore, when the length L of the parallel portion 7a of the main nozzle 7 is 5 mm, the gap is 10 mm or more. Similarly, the gap 31 between the side wall 17 of the curved line B on the bearing 13 side and the side wall 4a of the impeller 4 will be described.
The noise decreases sharply at 2L times. In this embodiment, it is 8 mm. The curve C is an experiment on the gap between the bottom surface of the lower case 1 and the impeller 4, but a gap larger than about 2L is required.

The width of the air turbine impeller 4 is approximately three times the radius of the impeller 4, the inner / outer diameter ratio is 0.25 to 0.55, and the side wall 4d.
The radius of curvature is approximately equal to or slightly larger than the radius of the impeller. The inner diameter of the main nozzle 7 is approximately the same as the radius of the impeller 4, and the length L of the parallel portion 7b is about 1/2 to 1/6 of the inner diameter of the main nozzle 7. Air turbine room 1
The arc of the rear wall 19 of 6 is approximately equal to the radius of the impeller 4,
The width of the inlet 22 of the rotary joint 15 on the inflow side is substantially equal to the width of the impeller 4 and the depth thereof is substantially equal to the outer diameter of the impeller 4. The radius of the impeller 4 of this embodiment is 20 mm.

FIG. 5 shows another embodiment of the suction device / main nozzle 7.
The central axes of the split surface of the impeller 4 and the receiving port 22 of the rotary joint 15 are aligned with each other, and the discharge airflow 9 is sucked without colliding with the peripheral wall of the turbine chamber 16 or the like, thereby reducing noise. The occurrence can be greatly suppressed.

With the above structure, vortices generated when the high-speed jet stream ejected from the main nozzle collides with the side wall and the rear wall of the air turbine impeller or the turbine chamber can be suppressed, so that noise can be significantly reduced. it can. According to the experiment, it has been found that the noise can be reduced by 5 to 10 dB, and the generated torque is increased by about 5% at the rotational speed of the impeller of 10,000 r / min.

[0018]

According to the present invention, the high-speed jet air stream ejected from the main nozzle can be rectified in the flow path formed by the main nozzle of the suction tool, the air turbine impeller, the turbine chamber, and the rotary joint. In addition, there is an effect that noise can be reduced and generated torque can be increased.

[Brief description of drawings]

FIG. 1 is a perspective view of a suction tool mounted on an air turbine according to an embodiment of the present invention.

FIG. 2 is a plan view with the upper case of FIG. 1 removed.

3 is a cross-sectional view of FIG.

FIG. 4 is an explanatory diagram showing a relationship between a gap and noise.

FIG. 5 is a plan view showing the other embodiment of the present invention with the upper case removed, as in FIG.

[Explanation of symbols]

1 ... Upper case, 2 ... Lower case, 3 ... Rotary brush,
4 ... Air turbine impeller, 4a ... Blade, 4b ... Blade L, 4c ... Blade R, 4d ... Side wall, 5 ... Shutter opening / closing mechanism, 5a ... Shutter, 5b ... Knob, 6 ... Nozzle support plate, 7 ... Main nozzle, 7a ... entrance side center, 7b ... parallel part,
8 ... High-speed jet airflow, 9 ... Discharge airflow, 9a ... Diffusion airflow, 10 ... Shaft, 11 ... Pulley, 12 ... Timing belt, 13 ... Ball bearing bearing, 14 ... Bearing holder, 15 ... Rotating joint, 16 ... Turbine chamber , 17 ... R side wall, 18 ... L side wall, 19 ... Rear wall, 20 ... Bypass nozzle, 21 ... Push-on fix, 22 ... Receptacle, 22
a ... projection, 22b ... side wall, 23 ... L-shaped joint, 24 ... central axis of suction port, 25 ... central axis of connection between receiving port and L-shaped joint, 26 ...
Center of the inlet on the impeller side, 27 ... axial center of the inlet, 28 ... rotary brush chamber, 29 ... gap between impeller and lower case,
30 ... Gap between nozzle support plate and impeller, 31 ... Gap between R side wall and impeller side wall, 32 ... Suction air.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Shigenori Sato Inventor, Kuridate-cho, Tsuchiura-shi, Ibaraki 502 Hiritsu Seisakusho Co., Ltd.Mechanical Research Laboratory (72) Inventor, Koji Nakagawa 502, Kintate-cho, Tsuchiura-shi, Ibaraki Nitate Seisakusho Co., Ltd. Inside the mechanical laboratory

Claims (7)

[Claims] 1. An air turbine that rotates around a shaft when a suction airflow strikes a plurality of blades extending outward from the shaft, and a rotary brush that rotates using the air turbine as a drive source. In the air turbine suction tool of the electric vacuum cleaner having a structure in which the central axis of the suction tool does not match the split surface of the air turbine impeller, the central axis of the nozzle matches the split surface of the air turbine impeller. In addition, the receiving shaft of the rotary joint has a substantially jogo shape that is asymmetric with respect to the central axis of the suction tool, and the central axis of the receiving port is substantially aligned with the center point on the inlet side of the nozzle. A vacuum cleaner air turbine suction tool. 2. The air turbine suction tool for an electric vacuum cleaner according to claim 1, wherein the gap between the air turbine impeller and the nozzle support plate or the side wall of the turbine chamber is about twice the parallel portion of the nozzle. 3. The air turbine suction tool for an electric vacuum cleaner according to claim 1, wherein the width of the air turbine impeller is about three times the inner diameter of the nozzle. 4. The air turbine suction for an electric vacuum cleaner according to claim 1, wherein an arc of a rear wall of the air turbine chamber and a side wall of the air turbine impeller is formed into a shape substantially equal to a radius of the impeller. Ingredient 5. The air turbine suction tool for an electric vacuum cleaner according to claim 1, wherein the length of the parallel portion of the nozzle is set to 1/2 to 1/6 of the inner diameter. 6. The air turbine suction tool for an electric vacuum cleaner according to claim 1, wherein the shape of the main nozzle and the bypass nozzle are circular or elliptical, and the opening area ratio is set to about 3: 1. 7. The vacuum cleaner according to claim 1, wherein the central axes of the suction tool / main nozzle and the split surface of the impeller, and the central axes of the rotary joint and its receiving port are aligned. Air turbine suction tool.