EP2064979B1 - Electric suction head - Google Patents

Description

The invention relates to a Elektrorosaugkopf for a vacuum cleaner with a housing, one of a disposed within the housing in an engine compartment electric motor cleaning device, a Saugmundkanten limited suction mouth on the underside of the housing and a suction port, wherein the engine compartment for the passage of air for cooling the electric motor has at least one air inlet opening for the entry of ambient air and at least one air outlet opening.

The electric suction head can have an accumulator or an electrical connection for supplying power to the electric motor via a vacuum cleaner. The electric suction head can be connected without restriction via a suction pipe and a flexible hose or directly to a dust-housing, in the latter case, the weight of the vacuum cleaner on the Elektrorosaugkopf loads. The suction pipe or the sucker are connected to the suction port. The electric suction head is usually removable from the suction pipe or the vacuum cleaner housing and can be kept ready as an accessory. In particular equipped with an accumulator Elektrorosaugköpfe can be retrofitted as an accessory in a variety of commercial vacuum cleaners.

Electric suction heads with the features described above are known in various embodiments from practice. In the generic electric suction heads, the waste heat of the electric motor to prevent overheating and consequent malfunction must be dissipated. Particularly in the case of a powerful electric motor, a poor efficiency of the electric motor or peak loads during the cleaning operation, the engine's own fans are not sufficient in the normally cramped installation conditions to dissipate the waste heat. From the Practice, it is therefore known to use the suction vacuum generated by a vacuum cleaner to direct a secondary air flow for cooling through the engine compartment of the electric motor. The electric motor has air inlet openings for the entry of ambient air and at least one air outlet opening. As air inlet and air outlet openings existing leaks or specially provided cooling air openings can be provided anyway, the air outlet openings open in the known versions in areas with a high negative pressure, for example, in a suction connection associated tilting joint or a suction channel within the housing. A corresponding embodiment is also from the JP 9 047 395 known.

From the publication JP 5 253 125 An electric suction head is known in which the cooling air from the electric motor enters through air inlet openings in the housing in the engine compartment and passes through air outlet openings of the engine compartment in a roll chamber of a brush roller. The disadvantage here is that the prevailing in the roll chamber vacuum and thus the cooling air flow is heavily dependent on the floor covering.

In the known embodiments, the suction-effective air volume and the pressure prevailing at the suction mouth vacuum is reduced by the required for cooling secondary air flow, the non-contributing to the suction side air flow is also referred to as incorrect or false air. Due to the required minimum amount of cooling air a good seal in the known versions of a Elektrorosaugkopfes is not possible.

Against this background, the invention has the object, in an electric vacuum head with the features described above to improve the suction and energy efficiency. In particular, while ensuring a sufficient cooling of the electric motor, the absorbent air amount can be maximized.

Starting from a Elektrorosaugkopf with the features described above, the object is achieved in that the at least one air outlet opening is arranged on the underside of the housing such that the exiting during operation of the electric vacuum head from the air outlet opening cooling air passes through at least one of Saugmundkanten in the suction , At the air inlet openings of the engine compartment when sucking there is usually about the ambient pressure, wherein in the region of the underside of the housing in which the air outlet opens, at least a slight negative pressure is created, whereby air is sucked from the environment and directed to the cooling of the engine and after leaving the air outlet openings together with a sucked at the bottom of the housing main air flow enters the suction mouth. According to the invention, the required cooling air is passed over at least one of the suction mouth edges and thus contributes to the total amount of air that is effective for suction. For the partial air flow of the cooling air takes place only in the flow direction before the Saugmundkanten a displacement of the suction. At the at least one air outlet opening at the bottom of the housing prevails in comparison to the known embodiments in which the air outlet opening is connected to a tilting joint, a suction channel or a roll chamber, a comparatively low negative pressure, which is why correspondingly large flow cross sections must be provided. However, this is readily possible due to the large area available at the bottom of the housing.

Preferably, a plurality of air outlet openings is provided on the underside of the housing in order, on the one hand, to achieve a sufficiently large flow cross section and, on the other hand, to prevent a malfunction in the event of clogging of an air outlet opening. Preferably a plurality of substantially identically formed air outlet openings arranged side by side. Basically, depending on the designs of the electric vacuum head and in particular the arrangement of the electric motor and air outlet openings seen in the working direction can be arranged in front of and behind the suction mouth, then passes over both Saugmundkanten each part of the entire cooling air into the suction.

In order to ensure a sufficient negative pressure for conveying the cooling air at the at least one air outlet opening, it is preferably arranged in an inflow region of one of the suction mouth edges. In a conventional construction of the electric suction head, the distance of the air outlet opening to the associated suction mouth edge is less than 30 mm, preferably less than 15 mm.

If a sealing lip, bristle strip or the like is provided on the underside of the housing, the at least one air outlet opening can expediently be arranged between the suction mouth and the sealing lip or the bristle strip. In addition to the pressure difference across the suction mouth edges, a further pressure drop is also observed at the sealing lip or the bristle strip, so that there is a defined under normal operating conditions negative pressure between the sealing lip or the bristle strip and the associated suction mouth.

As a result of the configuration according to the invention, the channels, spaces and joints along the suction air flow between the suction mouth and the suction connection can be made particularly dense without impairing the cooling in order to minimize the occurrence of false air. Rigid and articulated connections between the parts of the Elektrorosaugkopfes may be provided for example with seals or flexible connecting hoses.

Since the cooling air according to the invention contributes to the effective amount of air, a special high suction efficiency can be achieved even with a large demand for cooling air. Thus, the electric motor can easily be designed for a maximum power consumption under load of more than 50 W, preferably more than 100 W, particularly preferably more than 200 W.

In a preferred embodiment of the invention, the at least one air outlet opening is arranged in a recess between preferably approximately perpendicular to the Saugmundkanten ribs. By extending approximately in the direction of flow ribs and the set-back arrangement of the air outlet opening clogging of the air outlet opening can be prevented and a sufficient air flow can be ensured even in a long pile floor covering.

Starting from the described embodiment of a Elektrorosaugkopfes arise a variety of preferred developments. For example, cooling ribs and / or a fan wheel can be arranged on the electric motor to support the cooling. Furthermore, it can be provided that the cross-section of the air inlet opening and / or the air outlet openings is designed to be adjustable, in order to enable an adaptation to a different demand for cooling air. The adjustment of the cross section can be done manually or temperature controlled, wherein at a shutdown of the electric motor, the at least one air outlet opening or the at least one air inlet opening can be closed. It is also possible to variably increase or decrease the flow cross sections as a function of different functional and power settings of the electric motor. To change the cross section, an electrically or mechanically driven diaphragm can be provided. In addition, an automatic temperature control by means of a temperature sensor or a bimetal-controlled aperture can be done.

As part of a further embodiment of the invention, it is provided that a bypass is arranged on the engine compartment, which connects the engine compartment with a through-flow of the suction air channel or a through-flow of the suction chamber within the housing. By the bypass, an additional air flow can be provided, which allows for an excessive reduction of the flowing from the at least one air outlet opening cooling air flow emergency cooling. The bypass can expediently be pressure-controlled and closed during normal suction operation. If the suction air stream, for example, on a very langflorigem carpet or a clogged suction mouth decreases sharply, under certain circumstances, a sufficient cooling of the electric motor can no longer be ensured. At the same time, the negative pressure in the channels and chambers through which the suction air flows increases within the housing so that emergency cooling can be achieved by means of a bypass opening at a predetermined negative pressure.

In the context of the invention, a cleaning roller arranged in a roller space, which has spirally arranged lips or brush strips, is preferably provided as the cleaning device. The cleaning roller is usually aligned horizontally with its longitudinal axis perpendicular to the working direction of the Elektrorosaugkopfes. Without limitation, however, can be provided within the scope of the invention, a plurality of vertically or obliquely arranged to the processing direction cleaning rollers or other type of cleaning devices.

Fig. 1

eine perspektivische Ansicht eines erfindungsgemäßen Elektrosaugkopfes,

Fig. 2

der Elektrosaugkopf gemäß Fig. 1 in einer Ansicht von unten

Fig. 3

ein Vertikalschnitt entlang der Linie A-A der Fig. 2,

Fig. 4

der qualitative Verlauf des an der Unterseite des Gehäuses entlang der Linie A-A herrschenden Unterdrucks Δp.

The invention will be explained below with reference to a purely illustrative drawing. They show schematically:

Fig. 1

a perspective view of a Elektrorosaugkopfes invention,

Fig. 2

the electric suction head according to Fig. 1 in a view from below

Fig. 3

a vertical section along the line AA of Fig. 2 .

Fig. 4

the qualitative course of the prevailing at the bottom of the housing along the line AA negative pressure Ap.

Fig. 1 shows an electrosuction head 1 according to the invention in a perspective view. The electric suction head 1 has a housing 2 in which an electric motor 4 for driving a cleaning device 5 designed as a brush roller is arranged in an engine compartment 3. The bristles of the brush roller pass through on the underside of the housing 2 extending over the width of the electrosuction head 1 and of a front Saugmundkante 6a and a rear Saugmundkante 6b limited suction mouth 7. Sealing lips 8a, 8b are each in the direction of movement in front of the front Saugmundkante 6a and behind the rear suction mouth edge 6b arranged. In addition to display elements 9, 9 'and controls 10 2 air inlet openings 11 of the engine compartment 3 for the passage of air for cooling the electric motor 4 can be seen at the top of the housing. The electric suction head 1 has a suction connection 12 designed as a rotary tilting joint for connection to a suction pipe 13 or a vacuum cleaner housing. The power supply of the Elektrorosaugkopfes 1 can be done without restriction via an integrated into the Elektrorosaugkopf 1 voltage source or via a supply line from the vacuum cleaner. The electric suction head 1 is supported on its rear side by rollers 14.

Again Fig. 2 , which shows a bottom view of the Elektrorosaugkopfes 1, it can be seen, air outlet openings 15 of the engine compartment 3 are arranged on the underside of the housing 2 in the inflow region of the rear suction mouth edge 6b between the suction port 7 and the rear sealing lip 8b. At the air outlet openings 15 prevails in suction a certain negative pressure, so that cooling air is sucked through the air inlet openings 11 and the engine compartment 3 and after exiting the air outlet openings 15 via the rear Saugmundkante 6b enters the suction 7. The cooling air thus contributes to the suction-effective air flow, which flows into the suction mouth via the suction mouth edges 6a, 6b, whereby an optimization of the suction effect according to the invention is achieved.

The air outlet openings 15 are arranged in a row next to one another at an equal distance from the rear suction mouth edge 6b in each case in a depression between ribs 16 running perpendicular to the rear suction mouth edge 6b. By the ribs 16 and the set-back arrangement of the air outlet openings 15, the risk of clogging of the air outlet openings 15 can be reduced to a carpet.

In contrast to the embodiments known from the prior art, a very high tightness of the electric suction head 1 can be achieved even with a large power consumption of the electric motor. The electric motor 4 is typically designed for a power consumption under load of more than 50 W, preferably more than 100 W, particularly preferably more than 200 W.

Of the Fig. 3 It can be seen that the guided through the engine compartment 3 cooling air flow K is passed together with the sucked laterally at the bottom of the housing 2 main suction H via the Saugmundkanten 6a, 6b and is passed through a roller chamber 17 to the suction port 12. With the in Fig. 1 shown controls 10, different powers of the electric motor 4 can be adjusted, depending on the power position, the cross section of the air inlet openings 11 is adjusted with an associated aperture 18. If the total suction flow entering through the suction mouth 7, for example on a very long-pile floor covering or clogging of the suction mouth 7, strongly decreases, sufficient cooling can no longer be ensured by the cooling air flow K flowing over the air inlet openings and the air outlet openings. At the same time, due to the reduced total intake flow, the negative pressure in the roller chamber 17 increases. In order to avoid overheating of the electric motor 4 in such an operating state, a flap opening in the direction of the roll chamber 17 in the direction of the roll chamber 17 is arranged as a bypass 19 on the engine compartment 3. The bypass 19 is closed during normal suction and opens when a predetermined negative pressure is exceeded, whereby an emergency cooling is achieved by entering from the engine compartment directly into the roll chamber emergency cooling flow N.

Fig. 4 shows by way of example the prevailing at the bottom of the housing 2 in the longitudinal direction negative pressure Ap. In this case, in a first region I immediately below the suction mouth 7, a maximum negative pressure Δp max. observed in relation to the ambient pressure. At the suction mouth edges 6a, 6b, the negative pressure .DELTA.p decreases sharply, whereby the suction effect is decisively determined by the flow and the pressure distribution at the suction mouth edges 6a, 6b. In a second and a third region II, III between each suction mouth 6a, 6b and the associated sealing lip 8a, 8b, a reduced negative pressure is observed, which is sufficient, however, via the air inlet openings 11, the engine compartment 3 and the air outlet openings 15 a cooling air flow K to Cooling of the electric motor 4 to produce. In a fourth and a fifth region IV, V outside the sealing lips prevails about the ambient pressure

Claims (9)

1. Electric suction head for a vacuum cleaner comprising a housing (2), a cleaning device (5) able to be driven by an electric motor (4), arranged inside the housing (2) in a motor chamber (3), a suction orifice (7), delimited by suction orifice edges (6a, 6b) on the underside of the housing (2) and a suction connection (12), wherein the motor chamber (3) has at least one air inlet opening (11) and at least one air outlet opening (15) for the passage of air for cooling the electric motor (4), characterized in that the air outlet opening (15) is arranged on the underside of the housing (2) such that the cooling air, emerging out of the air outlet opening (15) when the electric suction head (1) is in operation, arrives into the suction orifice (7) via at least one of the suction orifice edges.
2. Electric suction head according to Claim 1, characterized by a plurality of air outlet openings (15) on the underside of the housing (2).
3. Electric suction head according to Claim 1 or 2, characterized in that the at least one air outlet opening (15) is arranged in a depression between ribs (16) running preferably approximately perpendicularly to the suction orifice edges (6a, 6b).
4. Electric suction head according to any of Claims 1 to 3, characterized in that the cleaning device (5) is constructed as a cleaning roller arranged in a roller chamber (17).
5. Electric suction head according to any of Claims 1 to 4, characterized in that the air outlet opening (15) is arranged in an approach flow region of one of the suction orifice edges (6a, 6b).
6. Electric suction head according to any of Claims 1 to 5, characterized in that on the underside of the housing (2) a sealing lip (8a, 8b) or a bristle strip is provided, with the air outlet opening being arranged between the suction orifice (7) and the sealing lip (8a, 8b) or the bristle strip.
7. Electric suction head according to any of Claims 1 to 6, characterized in that the electric motor (4) is designed for a maximum power consumption under load of more than 50 W (Watt), preferably more than 100 W, particularly preferably more than 200 W.
8. Electric suction head according to any of Claims 1 to 7, characterized in that the cross-section of the air inlet opening (11) and/or of the air outlet opening (15) is adjustable.
9. Electric suction head according to any of Claims 1 to 8, characterized in that a bypass (19) is arranged on the motor chamber (3), which connects the motor chamber (3) with a duct which has the suction air flowing through it, or with a chamber which has the suction air flowing through it, inside the housing (2).

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