JP2532134B2 - Vacuum cleaner suction body - Google Patents

Description

The present invention relates to a suction port body of an electric vacuum cleaner, and more particularly to a self-propelled mechanism of a suction port body.

(Prior Art) Conventionally, in the suction inlet of an electric vacuum cleaner, generally,
A structure was adopted in which all wheels for running the suction port main body on a surface to be cleaned such as a carpet were non-driven driven wheels. However, with this conventional structure, it is difficult to move the suction port main body because the resistance is large, especially when running on a carpet.

Therefore, conventionally, in order to assist the traveling of the suction port main body, a method has been adopted in which the rotation direction of the rotary brush is reversed in accordance with the traveling direction of the rotary brush built in the suction port main body and driven to rotate by an electric motor. . However, in this conventional method, the runnability is greatly influenced by the frictional force between the bristles of the rotating brush for scraping out the dust and the surface to be cleaned,
Depending on the type of surface to be cleaned, stable running performance could not be obtained. Moreover, the running performance was improved only when the rotating brush was rotated.

Further, conventionally, in an upright type electric vacuum cleaner in which a long handle is provided in a cleaner body having an integrated suction port body, a drive wheel which is rotationally driven by an electric motor for driving a rotary brush is fixedly provided. The structure was also adopted. In addition, in this conventional vacuum cleaner, a clutch mechanism is provided between the electric motor and the drive wheels, and the clutch mechanism is transmitted to the drive wheels by interlocking the clutch mechanism with a wire by a wire. The mechanical power is mechanically reversed. However, the drive wheel mechanism adopted in such an upright type electric vacuum cleaner increases weight and size, and is unsuitable as a suction port body as an attachment. Further, since the electric motor for driving the drive wheels and the electric motor for driving the rotating brush are common, the traveling property is improved only when the rotating brush is rotated. In addition, since the drive wheel and its power transmission section at the rear of the lower surface of the cleaner body are in air communication with the dust suction section at the front of the lower surface of the cleaner body, dust easily enters the drive wheel section, which improves reliability. However, in some cases, the drive wheels could be locked, causing the electric motor to overheat and lead to flames. Furthermore, since the drive wheels are fixedly provided, the drive wheels are overloaded depending on the type of the surface to be cleaned and the unevenness of the surface to be cleaned.

(Problems to be Solved by the Invention) As described above, in the suction port body of the conventional vacuum cleaner, the drive wheels for self-propelling are provided in a fixed position, so that the type of the surface to be cleaned and the unevenness Depending on the state and the like, the driving wheels may be overloaded, which may result in burnout of the driving electric motor, and there is a problem that the operability is poor.

The present invention is intended to solve such a problem, and an object thereof is to provide a suction port body of an electric vacuum cleaner that can prevent an overload from being applied to a drive wheel due to an uneven state of a surface to be cleaned. It is what Further, another object of the present invention is to facilitate the operation of changing the traveling direction at the suction port body of the electric vacuum cleaner. Further, another object of the present invention is to obtain an appropriate torque of the drive wheels according to the condition of the surface to be cleaned.

[Structure of Invention]

(Means for Solving the Problem) A suction port body of an electric vacuum cleaner according to the present invention is provided with a suction port body in which a dust suction part such as a suction port is provided on a lower surface part and a connecting pipe communicating with the dust suction part is provided outside. In a suction port body of an electric vacuum cleaner provided, a drive wheel support body composed of a case or the like is supported at a lower portion of the suction port body so as to be vertically movable and urged downward, and the drive wheel support body is supported by the drive wheel support body. Is rotatably supported, and an electric motor for rotationally driving the drive wheel and a transmission mechanism such as a belt for transmitting power from the electric motor to the drive wheel are provided inside the drive wheel support.

In addition, position the drive wheels almost symmetrically with respect to the connecting pipe.
A pair may be provided, and each of these drive wheels and an electric motor that rotationally drives these drive wheels may be connected via a differential gear mechanism.

Further, electrical contacts are provided on the suction port body side and the drive wheel support side, respectively, which contact and separate as the drive wheel support moves up and down, and at least one of the suction port body side and the drive wheel support side is provided. On the other hand, for example, on the suction port body side, a plurality of the electrical contacts for switching the voltage applied to the electric motor for driving the drive wheels may be arranged in the vertical direction.

(Operation) The suction port body of the electric vacuum cleaner of the present invention is used by connecting the hose or extension pipe connected to the cleaner body to the connecting pipe. When carrying a hose or the like and facing the suction port body to the surface to be cleaned such as a carpet or floor, suction or dust from the dust collecting section on the lower surface of the suction port body, such as connecting pipes, extension pipes, hoses, etc. It is led to the vacuum cleaner body through. At this time, when the electric motor in the drive wheel support body supported at the lower portion of the suction port main body is driven, the power of the electric motor is transmitted to the drive wheel supported by the same support body through the transmission mechanism in the support body, and this drive is performed. The wheel is rotationally driven, and the suction port body is rotated by itself on the surface to be cleaned by the rotation of the grounded drive wheel. Since the drive wheel support is vertically movably supported by the suction port main body and is urged downward, the user presses the suction port main body against the surface to be cleaned,
Alternatively, the support moves up and down relative to the suction port body depending on the type of the surface to be cleaned, the state of the unevenness, and the like.
As a result, the load applied to the drive wheels from the surface to be cleaned becomes relatively constant, and the drive wheels are prevented from being overloaded.

Further, in the suction port body of the electric vacuum cleaner according to claim 2, when the suction port body travels in a direction orthogonal to the rotation axis direction of the drive wheels, a pair of drive wheels positioned substantially symmetrically with respect to the connecting pipe. Almost equal power is transmitted to the motor through the differential gear mechanism. On the other hand, when changing the traveling direction of the suction port main body on the surface to be cleaned, the load applied to each drive wheel from the surface to be cleaned is different. The power is distributed, and the rotational speed of the drive wheel located inside the curved traveling direction is smaller than the rotational speed of the other drive wheels.

Further, in the suction port body of the electric vacuum cleaner according to claim 3, with the vertical movement of the drive wheel support body with respect to the suction port body, the electrical contact on the support body side comes into contact with and separates from the electrical contact on the suction port body side. . Then, for example, in the case where the lower side electrical contact of the plurality of electrical contacts lined up and down on the suction port main body side is in contact with the support side electrical contact, and in the case where it is in contact with the upper side electrical contact. , The applied voltage to the motor changes. Thus, as the drive wheel support moves up and down according to the type of the surface to be cleaned and the change in the surface shape, the torque and the rotational speed of the drive wheel are automatically switched.

(Example) Hereinafter, the structure of one example of the suction inlet of the vacuum cleaner of the present invention will be described with reference to the drawings.

In FIGS. 1 to 4, reference numeral 11 denotes a suction port main body having a left-right direction as a longitudinal direction, and the suction port main body 11 is a bumper.
It is composed of a lower main body case 13, an upper main body case 14 and a lid body 15 which are vertically connected via 12
Is detachably attached to the body cases 13 and 14. A suction port 16 is formed in the front portion of the lower surface of the lower body case 13 and extends in the left-right direction as a dust suction portion. A fitting recess 17 is formed on the lower surface of the lower body case 13 along the rear edge of the suction port 16, and a lip piece stand 18 is fitted and fixed in the fitting recess 17. Then, a lip piece 19 made of an elastic material such as rubber is provided on the lip piece base 18 so as to project downward, and the lip piece 19 is substantially parallel to the suction port 16 of the suction port body 11. It extends from the left end to the right end.

Further, driven wheels 20 are axially attached to the left and right sides of the lower surface front edge portion of the lower body case 13 with the left-right direction as the rotation axis direction.

Further, on the upper side of the center of the rear portion of the suction port body 11, a front end opening has a rotary tube facing the center portion in the left-right direction of the suction port 16.
Reference numeral 21 is pivotally mounted so that it can be tilted and lowered by a predetermined angle. That is, a support shaft portion formed on the right and left outer surfaces of the rotating tube 21 so as to project.
22 is rotatably held by the main body cases 13 and 14. Further, the rotating pipe 21 located outside the suction port body 11
A bent connecting pipe 23 is fitted and connected to the rear end portion of the rear end portion so as to be rotatable in the circumferential direction. Then, the rotating pipe 21 and the connecting pipe 23 constitute a connecting pipe 24 which communicates with the suction port 16.

A rotary brush 26 is rotatably supported in the suction port body 11 so as to face the suction port 16 from above and with the left-right direction as a rotation axis direction. This rotating brush 26
A plurality of brush bristles 28 are planted on the outer peripheral surface of a cylindrical brush stand 27. Although not shown, a DC motor for rotating the rotating brush 26 is provided on one side of the rear portion of the suction port body 11, and an output shaft of this motor is provided for power transmission. A belt is stretched around a fixed pulley and a pulley fixed to the rotating brush 26.

Further, at the bottom of the suction port body 11 and at the same time as the lip piece.
At the rear of 19, there is formed a support body storage portion 31 that opens downward, and this storage portion 31 is airtightly shielded from the space portion communicating from the suction port 16 in the suction port body 11 to the connecting pipe 24. ing. Further, on both the left and right sides of the support accommodating portion 31, there are groove portions 3 which are vertically open and open rearward.
2, 33 are formed respectively, and a pair of these groove portions 32, 3
3 is located symmetrically with respect to the connecting pipe 24.
In addition, the support accommodating portion 3 is located in front of each groove 32, 33.
Bearing holes 34, which are coaxial with each other in the left-right direction and open in opposite directions, are formed in both left and right side surface portions of the inside of 1, respectively. Further, a pair of left and right bosses 35 are vertically provided integrally with the upper surface of the support housing portion 31 located between the both groove portions 32, 33, and these bosses 35 center on the bearing hole 34. It is inclined in the tangential direction of the circle.

Reference numeral 41 is a drive wheel support, and the drive wheel support 41 includes a lower support case 42 and an upper support case which are vertically fixed and connected.
43, and the space formed between these support cases 42, 43 is a storage chamber 44.

Then, on the rear side of the left and right sides of the drive wheel support body 41, a box-shaped drive wheel cover portion 45 which is fitted into the groove portions 32 and 33 of the suction port body 11 and which is expanded upward and opened downward. , 46 are formed respectively. Further, at the front end portions of the left and right outer side surfaces of the drive wheel support body 41, support shaft portions 47 are coaxially formed so as to project. The support shafts 47 are rotatably fitted in the bearing holes 34 of the suction port main body 11, respectively, and the drive wheel support body 41 is provided below the support body storage portion 31 of the suction port main body 11. Is rotatably supported by a predetermined angle. Further, a pair of left and right cylindrical bosses 48 into which both bosses 35 of the suction port main body 11 are fitted from above are integrally formed on the upper surface of the drive wheel support 41 located between the both cover parts 45 and 46. The bosses 48 are inclined in a tangential direction of a circle centered on the support shaft portion 47. The drive wheel support 41 and the upper surface inside the support housing 31 of the suction port body 11 which are respectively wound around the corresponding bosses 35 and 48.
A pair of springs 49 are attached between the springs 49 and the upper surface thereof, and the springs 49 always urge the support 41 downward.

A DC motor 51 is supported and fixed in the storage chamber 44 of the drive wheel support 41 and on the side of one drive wheel cover portion 45. Further, a differential gear (differential gear) mechanism 53 forming a part of the transmission mechanism 52 is arranged at the center of the rear part of the storage chamber 44. The input shaft 54 of this differential gear mechanism 53
Has a front end portion axially supported by a metal bearing 56 fixed to ribs 55 formed on the support cases 42 and 43. Then, as the transmission mechanism 52, a pulley 57 fixed to an output shaft whose rotation axis direction is the front-rear direction of the electric motor 51 and a pulley 58 fixed to an input shaft 54 of the differential gear mechanism 53 are endless. The belt 59 is stretched.

Further, output shafts 61, 62 projecting from the differential gear mechanism 53 in both left and right directions are bearing holes 63, 64 formed in both left and right side surface portions of both drive wheel cover portions 45, 46 of the drive wheel support 41. The shafts are supported by metal bearings. The drive wheels 65, 66 are coaxially fixed to the output shafts 61, 62, respectively, located in the cover portions 45, 46, and the drive wheels 65, whose left and right directions are the rotation axis direction, are provided. 6
The lower part of 6 projects downward from the cover parts 45, 46.

Next, the structure of the differential gear mechanism 53 will be described with reference to FIG.

A first spur gear 71 is fixed to the rear end of the input shaft 54, and a substantially U-shaped first arm plate 72 is rotatably supported. Then, the both output shafts that rotatably pass through the both end portions of the first arm plate 72, respectively.
A second spur gear 73 and a third spur gear 74 are fixed to the inner end portions of 61 and 62, respectively. A first crown gear 75 is rotatably supported on the inner end of the one output shaft 62,
The crown gear 75 is meshed with the first spur gear 71. Further, a substantially L-shaped second arm plate 76 is fixed to a side surface of the crown gear 75, and an inner end portion of the other output shaft 61 is rotatably passed through a tip end portion of the arm plate 76. are doing.
A second crown gear 77, which is a planetary gear, is rotatably supported on the base of the second arm plate 76. This crown gear 77
Are meshed with the second and third spur gears 73 and 74, respectively.

Next, the configuration of electrical connection between the suction port body 11 side and the drive wheel support body 41 side will be described with reference to FIGS. 6 to 8.

The outer peripheral surface of the one boss 35 of the suction port body 11 has a first
Or, the fourth electrical contacts 81, 82, 83, 84 are fixed one after another in pairs in the vertical direction. On the other hand, on the inner peripheral surface of the corresponding cylindrical boss 48 of the drive wheel support 41, the first electrical contact 81 and the second electrical contact 82 or the third electrical contact 82 are generated as the support 41 moves up and down. Pair of fifth electrical contacts 85 with which the electrical contacts 83 and the fourth electrical contacts 84 are in contact with each other in a freely attachable / detachable manner.
And the sixth electrical contact 86 is fixed. The interval between the contacts 81, 82, 83, 84 arranged vertically on the boss 35 is smaller than the height of the contacts 85, 86 of the cylindrical boss 48.

Next, the configuration of the power supply circuit of the DC electric motor 51 that drives the drive wheels 65 and 66 will be described with reference to FIG.

Transformer for step-down in which primary coil is connected to AC power supply 91
Both ends of the secondary coil of 92 are rectifying diodes 9
It is connected to one pole of the smoothing capacitor 95 via 3,94, and the other pole of this capacitor 95 is connected to the middle point of the secondary coil. Then, one pole of the capacitor 95 is
While being directly connected to the first electrical contact 81,
It is connected to the third electrical contact 83 via a resistor 96. The other pole of the capacitor 95 is directly connected to the second and fourth electrical contacts 82, 84 in common. Further, the fifth and sixth electrical contacts 85, 86 are connected to both poles of the electric motor 51, respectively. That is, the contact 81, ...,
The switch 97 formed by 86 not only controls the on / off of the electric motor 51, but also has two operating contact modes of the electric motor 51. The power supply circuit is provided, for example, in the suction port body 11.

 Next, the operation of the above embodiment will be described.

At the time of cleaning, for example, the tip of the extension pipe connected to the cleaner body via a hose is detachably fitted and connected to the connection pipe 23.

And, for example, by holding the grip of the hose, the driven wheel 20,
When the drive wheels 65, 66 and the tips of the lip pieces 19 are grounded on the surface to be cleaned 100 such as a carpet or floor to clean, as shown by the arrows in FIG. The dust sucked together with the air from the suction port 16 facing the surface to be cleaned 100 is guided to the dust collecting chamber in the cleaner body through the connecting pipe 24, the extension pipe, the hose and the like, and is captured there. At this time, the lip piece 19 regulates the pressure distribution in the space between the lower surface of the suction port body 11 and the surface to be cleaned 100, and the low pressure portion is in front of the lip piece 19 and below the suction port 16. Limit to a small area. As a result, the negative pressure in the suction port 16 portion is increased and strong dust suction is performed.

Also, by turning on a switch (not shown),
When the electric motor for driving the rotating brush 26 is operating, the rotating brush 26 rotates to scrape dust from the carpet or the like.

By the way, hold the hose by the grip 11
In the state in which the drive wheel 65 is grounded, the drive wheel support 41, which moves up and down together with the drive wheels 65, 66 due to the load applied by the user, etc.
In contrast, it has been rising to some extent. Then, the fifth and sixth electrical contacts 8 on the drive wheel support 41 side
5,86, as shown in FIG. 7 or 8, the third and fourth electrical contacts 83, 84 or the first electrical contact on the side of the suction port body 11
And the second electrical contacts 81 and 82, respectively. Therefore, the electric motor 51 is in the operating state, and the drive wheels 65, 6 are transmitted from the electric motor 51 via the transmission mechanism 52 including the differential gear mechanism 53.
Power is transmitted to 6, and these drive wheels 65 and 66 rotate. Then, due to the rotation of the drive wheels 65, 66 that are grounded, the suction port body 11 self-propels in the front-rear direction on the surface 100 to be cleaned.

Further, the drive wheel support body 41 urged downward depending on the force of the user pressing the suction port main body 11 against the surface 100 to be cleaned, the type of the surface 100 to be cleaned, the state of irregularities, etc. It rotates in the up-down direction relative to the suction port body 11 around the portion 47. This allows the drive wheel 6 to be removed from the surface to be cleaned 100.
The load on 5,66 becomes relatively constant and these drive wheels
Prevents 5,66 from being overloaded. Therefore, it is possible to prevent the electric motor 51 from being burnt out due to an excessive current, and the traveling operability of the suction port body 11 is good.

When the drive wheel support body 41 is located relatively lower than the suction port body 11 according to the change in the surface shape of the surface to be cleaned as described above, as shown in FIG. The fifth and sixth electrical contacts 85, 86 on the side of the body 41 are the inlet body 1
It contacts the lower third and fourth electrical contacts 83, 84 of the one side. At this time, the electric motor 51 is connected to the power source via the resistor 96 shown in FIG. 9, and the voltage applied to the electric motor 51 becomes low, so that the drive wheels 65, 6 rotatably driven by the electric motor 51.
The torque and speed of 6 become smaller. On the other hand, when the support body 41 is located higher than the suction port main body 11, as shown in FIG.
The electrical contacts 85, 86 contact the upper first and second electrical contacts 81, 82 on the suction port body 11 side. At this time, the electric motor 5
Since 1 is directly connected to the power supply and the voltage applied to the electric motor 51 is increased, the torque and the rotational speed of the drive wheels 65, 66 are increased.

In this way, the applied voltage is automatically switched according to the type of the surface to be cleaned and the torque is automatically switched accordingly, but when the drive wheel support 41 is descending, the drive wheels 65 and 66 are cleaned. Since the load applied from the surface 100 is small and the load applied to the drive wheels 65 and 66 is large when the support 41 is raised, it is appropriate that the torque increases as the support 41 rises as described above. is there. That is,
The running operability of the suction port main body 11 is further improved.

Further, when the suction port main body 11 is temporarily lifted during the cleaning and floated in the air, the drive wheel support 41 is in the most lowered state with respect to the suction port main body 11 due to the repulsive force of the spring 49. At this time, as shown in FIG. 6, the contact points 85, 86 on the side of the support body 41 are the contact points 81, 82, 8 on the side of the suction port main body 11.
It is also far from 3,84. Therefore, the suction port body
When the 11 is lifted, the electric motor 51 is automatically turned off and the drive wheels 65, 66 are automatically stopped. When the drive wheels 65 and 66 are again grounded, the electric motor 51 is automatically turned on and the drive wheels 65 and 66 rotate.

In this way, the drive wheels 65, 66 only when the ground surface 100 is touched.
Since it is driven to rotate, it is safe and saves electricity.

By the way, when the suction port main body 11 travels in the front-rear direction, equal power is transmitted from the electric motor 51 to the pair of drive wheels 65 and 66 which are symmetrically positioned with respect to the connecting pipe 24 through the differential gear mechanism 53. To be done. That is, the differential gear mechanism is driven from the output shaft of the electric motor 51 via the pulley 57, the belt 59 and the pulley 58.
Rotation is transmitted to the input shaft 54 of 53, the first spur gear 71 and the first crown gear 75 rotate at a constant speed, respectively, and the second
The crown gear 77 revolves, but this second crown gear 77 does not rotate,
The second and third spur gears 73, 74 rotate at a constant speed, and both drive wheels 6
The rotation speed of 5,66 becomes equal.

However, when changing the traveling direction of the suction port main body 11 on the surface to be cleaned 100, the load applied to each drive wheel 65, 66 due to the friction with the surface to be cleaned 100 is different. Power is distributed to the drive wheels 65, 66 by the mechanism 53, and the drive wheels 65, 66 with less load are distributed.
The power of the electric motor 51 is intensively transmitted to. That is, the second crown gear 7 is driven at a speed corresponding to the difference in the loads applied to the drive wheels 65, 66.
7, the rotation speed of the drive wheels 65, 66 under a larger load is smaller than that of the other drive wheels 65, 66. For example, when changing the traveling direction to the left toward the front, the rotation speed of the left drive wheel 66 becomes smaller,
The opposite is true when changing the direction of travel to the right.

Therefore, the running direction of the suction port main body 11 can be easily changed to the left and right during cleaning, and the movement to the left and right becomes easy.

Further, since there is the lip piece 19 that is in contact with the surface to be cleaned 100, the suction airflow for sucking dust does not flow behind the lip piece 19, that is, on the drive wheels 65, 66 side. Therefore, dust is unlikely to adhere to the drive wheels 65 and 66, and the support case 4
Since there is no airflow that flows through the gap between 2, 43 or the bearing holes 63, 64, dust is unlikely to enter and adhere to the electric motor 51 and the transmission mechanism 52. Therefore, it is possible to prevent a situation in which the drive wheels 65 and 66 are locked, the electric motor 51 or the like is overheated due to the generation of an excessive current, and a flame is thereby generated.

Further, although the pressure inside the drive wheel cover portions 45, 46 of the drive wheel support body 41 in which the upper portions of the drive wheels 65, 66 are housed is almost always atmospheric pressure, the lip pieces 19 lower the drive wheels 65, 66. Since the pressure in the space between the lower surface of the support body 41 and the surface to be cleaned 100 that are protruding does not decrease, a pressure difference between the upper and lower sides of the drive wheels 65 and 66 does not occur. Therefore, a load due to the pressure difference is not applied to these drive wheels 65 and 66, and the power loss is reduced.

Further, particularly when the surface to be cleaned is folded, the lip pieces 19 can prevent the hair of the carpet from being inclined due to negative pressure and adversely affecting the rotation of the drive wheels 65 and 66.

The means for pneumatically isolating the suction port 16 side from the drive wheels 65, 66 side is not limited to the lip piece 19, but a protrusion formed integrally with the lower surface of the suction port body 11 or a fixed one-line fixing It may be a brush, an elongated roller, or the like.

Also, the electric motor for driving the rotating brush 26 and the drive wheels 65, 66
Since it is separate from the driving electric motor 51, the suction port body 11 can be self-propelled even when the rotating brush 26 is not rotating.

Furthermore, the fact that the drive wheel mechanism is unitized by the drive wheel support 41 is advantageous in manufacturing and the like. For example, the drive wheel support 41 includes a support shaft portion 47 for the suction port body.
Although it can be attached to and detached from the suction port main body 11 by engaging and disengaging from the bearing hole 34 of 11, the same support is provided with a unit in which a non-driven driven wheel is axially attached, and the manufacturer or It is also possible for the user to easily select or replace the drive wheels 65, 66 and the driven wheels.

〔The invention's effect〕

 According to the present invention, the following effects can be obtained.

In the suction port body of the electric vacuum cleaner according to claim 1, a drive wheel support body having an electric motor and a power transmission mechanism built-in is provided below the suction port body so as to be vertically movable and urged downward to support the drive wheel. Since the drive wheel is supported by the support, it is possible to prevent the drive wheel from being overloaded due to the drive wheel moving up and down with respect to the suction port body depending on the type of surface to be cleaned and the state of the unevenness. Therefore, it is possible to improve the traveling operability of the suction port main body and prevent burning of the drive motor due to excessive current.

Further, in the suction port body of the electric vacuum cleaner according to claim 2, a pair of drive wheels are provided so as to be positioned substantially symmetrically with respect to the connecting pipe of the suction port body, and each of the drive wheels and the electric motor is provided with a differential gear mechanism. When changing the running direction of the suction port main body, the rotational speed of these drive wheels will differ depending on the load applied to both drive wheels. The operability of change is improved.

Further, in the suction port body of the electric vacuum cleaner according to claim 3, an electric contact that is freely contactable and separable is provided on the suction port body side and the drive wheel support body side, and at least one of the suction port body side and the drive wheel support body side is provided. Since the electric contacts are arranged vertically, the applied voltage to the electric motor can be switched according to the vertical movement of the drive wheel support body.Therefore, according to the type and condition of the surface to be cleaned, the drive wheel The torque can be automatically adjusted to an appropriate value, and the traveling operability of the suction port body can be further improved.

[Brief description of drawings]

FIG. 1 is a sectional view taken along the line I--I of FIG. 3 showing an embodiment of the suction port body of the electric vacuum cleaner of the present invention, and FIG.
Sectional view, FIG. 3 is a perspective view of the same as above, FIG. 4 is an exploded perspective view of the drive wheel support portion of the same, FIG. 5 is a plan view of the differential gear mechanism of the same as above, and FIGS. FIG. 9 is a circuit diagram of the same as FIG. 11 ... Suction port body, 16 ... Suction port as a dust suction part, 24 ...
… Connecting pipe, 41 …… Drive wheel support, 51 …… Motor, 52 ……
Transmission mechanism, 53 …… Differential gear mechanism, 65,66 …… Drive wheel, 81,
82,83,84,85,86 ... electrical contacts.

Claims (3)

(57) [Claims] 1. A suction port body provided with a dust suction portion on a lower surface portion and a connecting pipe communicating with the dust suction portion on an outer side. A drive wheel support is vertically movable downward at a lower portion of the suction port body. The drive wheel is urged and supported by the drive wheel supporter so that the drive wheel is rotatably supported by the drive wheel support body, and an electric motor for rotationally driving the drive wheel inside the drive wheel support body and power from the electric motor to the drive wheel are provided. A suction mechanism for an electric vacuum cleaner, comprising a transmission mechanism for transmitting. 2. A pair of drive wheels are provided substantially symmetrically with respect to the connecting pipe, and each drive wheel and an electric motor for rotationally driving these drive wheels are connected via a differential gear mechanism. The suction port body of the vacuum cleaner according to claim 1. 3. An electric contact which is brought into contact with and separated from the suction port body side and the drive wheel support body side as the drive wheel support body moves up and down is provided, and the suction port body side and the drive wheel support body side are connected to each other. 3. A plurality of the electrical contacts for switching the voltage applied to the driving wheel driving electric motor are provided in at least one of the electric contacts side by side in the vertical direction.
Suction mouthpiece of the vacuum cleaner described.