JPH06105772A - Vacuum cleaner mouthpiece - Google Patents

Abstract

(57) [Abstract] [Purpose] To reduce the noise of the suction portion of the electric vacuum cleaner that rotates the brush using the air turbine as the power source and increase the impeller output torque of the air turbine. [Structure] A swingable rotary tube 4 is arranged behind an impeller 2 of an air turbine, and an axial flow passage width 2 at an opening of the rotary tube 4 is arranged.
a is longer than the impeller blade width, and impeller 2 in the suction portion direction
The center position of the rotary tube 4 and the center position of the opening of the rotary tube 4 are substantially the same. Further, the height of the impeller rotating shaft 3 from the floor surface is set higher than the nozzle, and the lowest point of the nozzle and the lowest point of the impeller are made substantially the same.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suction portion of a vacuum cleaner, and more particularly to a suction portion of a vacuum cleaner suitable for a vacuum cleaner equipped with an air turbine.

[0002]

2. Description of the Related Art The suction port of a conventional electric vacuum cleaner equipped with a rotary brush driving air turbine comprises a suction port body and a rotary tube, and the rotary tube connects a hose connecting the suction port body and the vacuum cleaner body. It is configured to do. A semi-cylindrical portion is provided at the tip of the rotary pipe so as to cover the air turbine. Furthermore, the rotary pipe is swingable with respect to the suction port main body, and the swing center is the semi-cylindrical portion. It was near the center of rotation of the air turbine on both sides. An example of this conventional mouthpiece is described in Japanese Utility Model Laid-Open No. 1-28761.

[0003]

In the above prior art, the angle of the circumferential direction defined by the nozzle portion from the inlet side of the turbine to the outlet side of the turbine changes due to the swing of the rotary tube. Therefore, as the flow length of the air flow for driving the turbine changes in the turbine, the fluid resistance changes, and the rotation speeds of the turbine and the rotating brush change. As a result, there is a problem in that dust is unevenly collected by the rotating brush and cleaning of the carpet surface or the like becomes uneven. Further, since the rotary tube and the suction port main body are configured so as to partially overlap each other, the height of the suction port main body becomes high and a double cylindrical surface is formed, which hinders reduction in size and weight. Therefore, if the clearance between the rotary tube and the turbine is narrowed to reduce the height, the optimal turbine nozzle clearance cannot be ensured due to the swing of the rotary tube, and the airflow collides with the wall surface of the rotary tube, causing fluid resistance. Will increase and the output torque of the turbine will decrease. When the rotary tube rotates upward, the semi-cylindrical portion on the upper surface side of the rotary tube wraps around the upper nozzle portion. Conversely, when the rotary tube rotates downward, the semi-cylindrical portion on the lower surface side of the rotary tube becomes the lower nozzle portion. Since it wraps around, the nozzle gap is changed, and the flow separates due to the collision of the inflowing airflow with the wall surface, resulting in loud noise.

By the way, the air turbine needs a large torque (rotational force) in order to compensate the resistance of the carpet or the like and the loss of the timing belt for transmitting the turbine output to the rotating brush. For example, 180 gf. A torque of cm is required. Here, the torque of the air turbine is
It is proportional to the product of the "jet flow rate" and the "jet flow velocity" of the nozzle. The torque is determined by the resistance coefficient of the resistor (carpet, tatami, etc.) when the brush rotates. In addition, the blown air volume is affected by the blower performance of the cleaner body, but in general, the microcomputer inside the cleaner body operates so that the blower operates with an air volume that increases the suction work of the blower.
Controlled from 1.2 to 1.5 m ³ / min. Therefore, at these "jet flow rates", the "jet flow velocity" of the nozzle required for the air turbine to output the required torque is approximately
It reaches 100m / s and requires a high-speed jet stream. The noise of the air turbine is the jet noise from the nozzle,
Collision sound when jet stream collides with blades, collision sound caused by collision of air flow directly from nozzle and flow through impeller, collision caused by collision of air flow directly out of nozzle with wall surface around turbine Expressed as the sum of sounds. Among them, in particular, and are large, and their sizes are almost at the same level. In order to reduce this jet noise, it is sufficient to lower the flow velocity of the nozzle, but the generated torque also becomes smaller and the rotating force of the rotating brush loses the resistance of the carpet, etc., and there is a problem that it will not rotate. You have to make sure the jet stream is flowing. Further, the noise of the suction port body cannot be significantly reduced unless the collision noise with is also reduced.

The present invention has been made to solve the above problems, and provides a suction port of an electric vacuum cleaner which has a torque required to rotate a rotary brush and reduces airflow noise of an air turbine. To aim.

[0006]

To achieve the above object, an air turbine provided with a rotary shaft and an impeller having a plurality of blades attached to the shaft and extending in a radial direction of the shaft, and the air turbine. In a suction port of an electric vacuum cleaner including a nozzle that supplies a jet to a turbine and a rotary brush that is driven by torque generated by the air turbine, a rotary tube that is swingable on the side opposite to the nozzle with respect to the impeller. And the width of the impeller side opening of the rotary tube in the axial direction of the rotary shaft is equal to or larger than the width of the blade of the air turbine in the direction. Further, an air turbine having an impeller that is rotated by applying a suction airflow from a nozzle, a rotary brush that is driven by a torque generated by the air turbine, an impeller attached to the turbine, and an air turbine that is discharged from the air turbine. A rotary tube for guiding the airflow to the main body of the electric vacuum cleaner is provided, and the center positions of the impeller and the rotary tube are close to each other in the central axis direction of the impeller. Further, the center positions of the impeller and the rotating tube in the central axis direction of the impeller are close to each other. Further, the rotary shaft is disposed above the nozzle, the height of the lower end surface of the nozzle and the height of the lowest outer peripheral surface of the impeller are made substantially the same, and the blade length (l) of the impeller is set to the opening of the nozzle. It is 70% or more of the diameter (Dn). In addition, the blade tip of the impeller is formed with an arc larger than the blade thickness. Further, the impeller is formed of two divided impellers, and the blade length is changed from the abutting portion side of each of the divided impellers toward the axial end. Further, the impeller is formed of a plurality of divided impellers,
The shape of the boss portion in the cross section parallel to the axis of the impeller is symmetrical with respect to the axial center of the impeller and is substantially arcuate.

[0007]

In the present invention, the rotary tube can swing up and down,
Since it is placed behind the air turbine, even if the rotary tube is turned up and down, the flow path length from the impeller of the suction airflow from the nozzle to the rotary tube opening hardly changes, so the flow path resistance changes. Without doing so, the rotation speed of the impeller becomes stable, the torque transmitted to the rotating brush does not change, and the cleaning performance of the carpet surface and the like becomes stable. Further, the shape of the inlet passage of the impeller does not change when the rotary tube rotates upward or downward, and the turbine chamber wall surface and the rotary tube wall surface are formed by smooth curves. Therefore, the inflow angle of the airflow from the nozzle and the impeller does not change, and the generation of vortices in the airflow is suppressed and the noise energy
Can be reduced.

By the way, in the air turbine of the suction port of the electric vacuum cleaner, it is an essential condition that slender dust such as needles, toothpicks, hairs, etc. flows out downstream without obstructing the rotation of the impeller. . For this reason, the peripheral speed of the impeller is significantly reduced with respect to the speed of the jet flowing out from the nozzle, and most of the jet bypasses the impeller and only part of the flow passes between the impeller blades. Is required. In the present invention, most of the jets can bypass the impeller by setting the opening width of the rotary tube to be equal to or larger than the impeller width and bringing these center positions close to each other.

Since the peripheral speed of the impeller is significantly lower than the speed of the jet flowing out from the nozzle, the flow passing between the impeller blades collides with the impeller blades. Therefore, immediately after the impeller flows out, the jet that flows out of the nozzle is avoided and flows while making a U-turn to both shaft end sides of the impeller. Most of the airflow that collides with the impeller flows on the bottom side of the air turbine while diffusing in the axial direction of the impeller, and flows into the opening of the rotary tube. In the present invention, since the opening width of the rotary tube is set to be equal to or larger than the impeller width, the flow passing between the impeller blades and the flow bypassing the impeller of the jet flowing out from the nozzle smoothly flow into the rotary tube, and -Because there is no separation from the downstream wall surface of the bottle impeller or the wall surface of the rotary tube, no noise is generated due to the occurrence of turbulence due to separation.

Further, since the cross-sectional shape of the boss portion of the impeller is formed in an arc shape to the left and right, the airflow flowing between the jet blades quickly diffuses in the axial direction of the blades along the bend of the boss portion. The noise when colliding with the blades can be moderated.
Furthermore, since the flow that collides with the impeller passes through both end faces of the impeller in the rotation axis direction, it does not collide with the impeller again, and noise can be prevented.

[0011]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view of a suction port of an electric vacuum cleaner according to an embodiment of the present invention parallel to a floor to be cleaned, and FIG. Is. The air turbine includes a nozzle 1, an impeller 2 having a plurality of blades, an impeller rotating shaft 3, and a rotary tube 4 that is swingable up and down behind the impeller 2. The swing shaft inlet width 4a of the opening of the rotary tube 4 is the same as the blade width 2a of the impeller 2, and a rotatable suction joint 5 is connected to the cleaner body side. In addition, the suction port has air
In addition to the turbine, a rotary brush 6, a timing belt 7 for transmitting the rotational force of the air turbine to the rotary brush, and a suction case 8 are provided.

Next, the operation of the suction portion of the thus constructed vacuum cleaner will be described. When you turn on the vacuum cleaner,
Suction air is drawn from the floor of the suction case 8 to the rotary brush 6
Flow path in the order of the flow path in the vicinity of the nozzle, the nozzle 1, the impeller 2 of the air turbine, and the rotary tube 4. The suction airflow 9 near the nozzle 1 is
The jet 10 is narrowed down by the nozzle 1 and flows into the impeller 2 of the air turbine, and a rotational force (torque) is given to the impeller by the momentum of the jet 10. The rotation is transmitted to the rotary brush 6 by the timing belt 7 to rotate the rotary brush 6. Rotary brush 6
By rotating, the dust is scraped off from the cleaning surface of the carpet or the like to collect the dust.

When the suction joint 5 and an extension pipe (not shown) are connected to the suction portion of such a structure and sliding is performed back and forth on the surface to be cleaned for cleaning, even if the rotary tube 4 rotates in the vertical direction. Since the rotary tube 4 is located behind the impeller 2, that is, on the downstream side as shown by the broken line in FIG.
The flow path length of the suction airflow passing through the rotary pipe 4 becomes constant. As a result, the required rotation torque can be kept constant, and the rotation of the impeller can be stably transmitted to the rotating brush 6, so that the carpet surface or the like can be cleaned uniformly and the dust collection performance can be maintained. Further, the cross-sectional shape of the front end of the rotary tube 4 which is perpendicular to the axis is an arc shape so that the rotary tube can swing, and its diameter d ₅ is smaller than the diameter d _{2 of the} impeller 2. Therefore, the suction port height can be made lower than that of the rotary tube covering the impeller, and cleaning of a narrow space under the bed or the like becomes easy.

Further, when the rotary tube 4 is above (flow of B) or below (flow of B), the bending in the flow direction in the wake of the impeller is gentle.
The airflow from the nozzle 1 and the impeller 2 is smoothly guided to the main body of the electric vacuum cleaner, and noise generation and ventilation resistance can be suppressed. Further, since the flow channel width of the flow channel formed between the lower outer peripheral surface of the impeller 2 and the turbine wall surface 17 does not change even if the rotary tube swings, the dust collecting performance is deteriorated due to clogging of dust. There is no worry to cause. Further, since the turbine chamber wall 17 and the rotary pipe wall surface 18 are formed by continuous smooth curves, separation of the airflow discharged from the impeller 2 from these wall surfaces is suppressed, and noise generated due to separation is generated. Is less likely to occur.

Since the peripheral speed of the impeller is remarkably low with respect to the speed of the jet airflow 10 flowing out of the nozzle, most of the jet flows around the impeller as indicated by arrow 14 in FIG. Passes between the impeller blades. The flow passing between the impeller blades collides with the impeller blades and the arrow 11
The jet 10 flowing out from the nozzle like a and 11b avoids the jet 10 and flows in a U-turn shape toward the blade vehicle end side. The flow colliding with the impeller flows like 12a, 12b, 13a, 13b, and finally flows into the suction joint 5. During this time,
The airflow passages 15 and 1 outside the both end surfaces of the impeller in the rotation axis direction.
The airflow passing through 6 passes through the opening of the rotary tube 4 having the same width 4a as the blade width 2a of the impeller 2 and flows along the wall surface of the rotary tube. As a result, the bypassed flow 13a,
It is possible to prevent a rapid change in the flow direction that occurs when 13b flows into the rapid contraction path, the flow does not separate from the wall surface, and noise due to the turbulence due to separation does not occur.

In this embodiment, the center position of the impeller 2 and the center position of the rotary tube 4 do not overlap, but they are made to coincide with each other in the width direction of the suction portion, or the width 4a of the opening portion of the rotary tube 4 is made equal. If the width is longer than the impeller width 2a, the flow bypassing the impeller is sucked into the opening of the rotary tube without colliding with the wall surface, and flows to the outlet of the suction joint 5 with less fluid loss, so that the noise reduction effect is further increased. .

FIG. 3 shows the positional relationship of the nozzle 1 and the impeller 2 in the direction perpendicular to the floor surface. The impeller shaft 3 is located above the upper end of the nozzle hole, and the height from the floor surface is substantially the same. The nozzle lower point position and the outermost peripheral surface lowermost point of the impeller 2 are located at the positions. The blade length 1 (outer blade radius-inner blade radius) is set to 70% or more of the nozzle opening diameter Dn. In this embodiment, the blade length 1 of the impeller 2 is set to 12.5 m.
m, and the nozzle opening diameter Dn was 16 mm. FIG. 4 is a diagram showing this positional relationship as seen from the front side of the nozzle. The torque of the impeller 2 is generated by the difference in angular momentum between the inflow part and the outflow part of the blade. Since both the inflow part and the outflow part of the flow of the impeller of the air turbine are at the tip of the outer peripheral edge of the impeller 2, the vane outer edge of the impeller 2 is closest to the floor surface, that is, the blade. When it is at the lowest point in the radial direction,
This torque becomes the largest. Here, if the length of the blade 2a is short, even if the jet airflow 10 flows in between the blades, it immediately flows out in the axial direction, and a sufficient torque cannot be obtained.
On the other hand, if the length of the blades 2a is too long, the jet airflow enters between the blades too much, and the airflow that has flowed out in the axial direction becomes difficult to escape. Torque is generated in the direction opposite to the direction of rotation, resulting in negative work. Therefore, the blade length 1 is selected so that the jet airflow 10 from the nozzle 1 works most efficiently on the impeller 2. According to an experiment conducted by the present inventor, the minimum turbine torque (200 gf · cm) required for the rotary brush is obtained when the blade length 1 is 70% or more with respect to the nozzle opening diameter Dn as shown in FIG. ) Was found to be able to obtain.

Therefore, in the first embodiment of the present invention, as shown in FIG.
As shown in Fig. 2, two runners, a runner (right) 2R and a runner (left) 2L, are adjoined to form an impeller 2. Each runner has eight blades, and the blades are
It is arranged to be shifted left and right in the circumferential direction. The jet airflow 10 from the nozzle 1 collides with the runners-2R and 2L of the impeller 2, but the left and right runners are displaced from each other in the circumferential direction, so that the impact per runner is alleviated.
In addition, the tip of the blade is formed in an arc larger than the thickness of the blade plate, and the blade tip 19 is rounded as shown in FIG. The following blade rotation noise can be suppressed.

Another embodiment of the impeller is shown in FIGS. The impellers of FIGS. 8 and 9 have two runners 20L, 2
The blade height was changed from the 0R seam toward the end in the axial direction. FIG. 8 shows a situation in which the jet airflow from the nozzles hits the runners 20R and 20L of the impeller 2. The jet airflow discharged from the nozzle has the maximum velocity, and when it collides with the blade of the impeller, the flow is disturbed and the noise is increased. According to the present embodiment, the timing at which the airflow collides with the blade is shifted, so
A so-called skew effect is obtained, and noise can be further reduced as compared with the case where only the arrangement in which the right and left 8 sheets are alternately shifted.

The impellers of FIGS. 10 and 11 are runner-21.
R (right), 21C (center), and 21L (left) are formed, and a boss with a substantially arcuate cross section is formed from the center of the runner-21C to the left and right. FIG. 10 shows a situation in which the jet airflow from the nozzle hits the impeller and flows between the blades. As a result, the jet airflow immediately flows between the blades and is immediately dispersed right and left along the bend of the boss portion and diffuses in the axial direction of the impeller, so that noise generated by colliding with the blade boss portion can be reduced. I understand.
Further, due to the effect of bending in the blade cross section, the flow colliding with the impeller easily passes through both end faces in the rotation axis direction of the impeller, so that the flow collides with the impeller again or returns to the nozzle side. Within. This prevents noise due to re-collision with the impeller and noise due to mixing of the return flow and the jet. Further, the effect of increasing the output of the impeller can be obtained.

[0021]

According to the present invention, since the swingable rotary tube is arranged behind the impeller and the axial flow passage width of the rotary tube opening is made longer than the impeller blade width, the rotary tube is The shape of the suction flow path formed by the nozzle and the rotary tube does not change even when it rotates, and the flow path length from the nozzle to the exit of the impeller does not change, so the output torque of the impeller is stable and the torque is stable. Since it is stably transmitted to the rotating brush, the cleaning performance of the carpet surface etc. is stable, and since the change in the flow path shape is small, the generation of noise due to collisions etc. is suppressed, and a low noise and high performance vacuum cleaner A mouthpiece can be provided.

[Brief description of drawings]

FIG. 1 is a plan view in which a partial cross-sectional view is also used, except for an upper case 2 of a mouthpiece of an embodiment of the present invention.

FIG. 2 is a cross-sectional view perpendicular to the impeller rotating shaft of the suction port of the embodiment of the present invention.

3 is a cross-sectional view near the impeller of FIG.

FIG. 4 is a cross-sectional view of an impeller viewed from the nozzle direction in FIG.

FIG. 5 is a graph showing changes in rotational torque according to another embodiment of the present invention.

FIG. 6 is a perspective view of an impeller of this embodiment.

FIG. 7 is a cross-sectional view of the impeller side.

FIG. 8 is a diagram showing a flow state in which the suction airflow hits the impeller according to the embodiment of the present invention.

9 is a perspective view of FIG. 8. FIG.

FIG. 10 is a diagram showing a flow state in which the suction air flow hits the impeller according to the embodiment of the present invention.

11 is a perspective view of FIG.

[Explanation of symbols]

 1 ... Nozzle, 2 ... Impeller, 2a ... Impeller wheel axial direction length, 4 ... Rotating tube, 4a ... Rotating tube opening length, 5 ... Suction joint, 8 ... Suction part case, 9 ... Suction airflow, 10 ... Jet airflow, 11 ... Flow passing between impeller blades, 12 ... Flow passing between impeller blades, 13 ... Flow passing between impeller blades, 14 ... Flow bypassing impeller, l ... Blade length Dn ... Nozzle opening length, 20R ... Runner- (right), 20L ... Runner- (left), 21R ... Runner- (right), 21C ... Runner- (center), 20L ... Runner- (left).

Front page continuation (72) Inventor Katsumasa Mikami 1-1-1, Higashitaga-cho, Hitachi City, Ibaraki Prefecture Living Equipment Division, Hitachi, Ltd. (72) Masaro Sunagawa 1-chome, Higashitaga-cho, Hitachi City, Ibaraki Prefecture No. 1 Incorporated company Hitachi Ltd. Living Equipment Division

Claims (7)

[Claims] 1. An air turbine having a rotating shaft and an impeller attached to the shaft and having a plurality of blades extending in a radial direction of the shaft, a nozzle for supplying a jet to the air turbine, and the air turbine. In a suction part of an electric vacuum cleaner equipped with a rotary brush driven by the torque generated by, a swingable rotary tube is arranged on the side opposite to the nozzle with respect to the impeller, and in the axial direction of the rotary shaft. A suction part of an electric vacuum cleaner, wherein a width of an impeller side opening of the rotary tube is equal to or larger than a width of the air turbine in the direction. 2. An air turbine having an impeller that rotates by applying suction air from a nozzle, a rotary brush driven by the torque generated by the air turbine, an impeller attached to the turbine, and the air turbine. A rotary tube for guiding the airflow discharged from the vacuum cleaner to the main body of the electric vacuum cleaner, wherein the center positions of the impeller and the rotary tube in the central axis direction of the impeller are close to each other. Mouthpiece. 3. The suction part of the vacuum cleaner according to claim 1, wherein the center positions of the impeller and the rotary tube are close to each other in the central axis direction of the impeller. 4. The impeller blade length (l) is set so that the rotary shaft is disposed above the nozzle, the lower end surface of the nozzle and the outermost peripheral surface of the impeller are substantially the same in height. The suction portion of the vacuum cleaner according to claim 1, wherein the opening diameter (Dn) of the nozzle is 70% or more. 5. The suction portion of the electric vacuum cleaner according to claim 1, wherein the blade tip of the impeller is formed in an arc larger than the blade thickness. 6. The impeller is formed of two divided impellers, and the impeller length is changed from an abutting portion side of each of the divided impellers toward an axial end portion. The mouthpiece of the electric vacuum cleaner according to 1. 7. The impeller is formed of a plurality of divided impellers, and a shape of a boss portion in an axially parallel cross section of the impeller is symmetrical with respect to an axial center of the impeller and is substantially arcuate. The suction part of the electric vacuum cleaner according to claim 1.