EP2540204B1 - Auxiliary air valve, vacuum cleaner and mounting method - Google Patents

Description

Field of the invention

The invention relates to a secondary air valve for a vacuum cleaner, with a housing, an inlet opening for the secondary air flow, an outlet opening for the secondary air flow and a pressure-dependent opening closure means for blocking the flow connection between the inlet opening and the outlet opening. The invention also relates to a vacuum cleaner with a suction nozzle, a suction fan that is flow-connected to it, a dust separation device arranged in the suction channel, a pressure sensor that is operatively connected to the suction channel and a secondary air valve for selectively feeding a secondary air flow into the flow channel, as well as a method for assembling such a vacuum cleaner.

Background of the invention

Vacuum cleaners are used to pick up dirt on floor surfaces, furniture or the like by means of a suction air stream. For this purpose, the suction mouth of a suction nozzle is placed on the surface to be cleaned so that dust or other contaminants are sucked in by the suction air flow. The suction air flow is generated by a suction fan which is in flow connection with a dust separation device, for example a centrifugal separator or a dust filter bag. The dirt particles picked up by the suction nozzle are collected in the dust separation device, while the cleaned air is released into the environment. The suction mouth of a suction nozzle suitable for floor cleaning usually has a rectangular shape and extends transversely to the sliding direction. It is desirable that a homogeneous negative pressure is applied over the entire width of the suction mouth in order to achieve a uniform suction result. In order to be able to use the power of the suction fan particularly effectively, the lowest possible pressure loss between the suction mouth and the suction fan is also advantageous.

The suction fan and the dust separator can for example be attached to a push tube that is mechanically connected directly to the suction nozzle and usually also forms part of the flow channel between the suction nozzle and the suction fan (stick vacuum cleaner). According to another common design, the suction fan and the dust separation device are arranged in the housing of a separate unit carrier, which can be moved over the floor surface by means of a chassis and is flow-connected to the push tube inserted into the suction nozzle by a flexible hose line (canister vacuum cleaner).

In order to prevent the suction fan or other electrical or electronic components from being damaged by overheating when the suction area, for example the suction nozzle, hose or dust filter, is closed, a secondary air valve is often arranged in vacuum cleaners, which in this case provides a secondary air flow to the suction fan and prevents an interruption of the cooling air flow. Alternatively or additionally it can be provided that the vacuum cleaner is equipped with a pressure sensor. A pressure sensor, which is functionally connected to the electrical or electronic control of the vacuum cleaner, can be used to measure the increasing negative pressure in the suction channel when the suction nozzle is closed, in order to reduce the suction fan output in the event of such an event. A pressure sensor can also be used to continuously indicate the negative pressure to the user of the vacuum cleaner or that a threshold value has been exceeded, for example via a visual pressure indicator in the form of a pointer or a lighting device.

From the patent specification DE 10 2006 030 227 B3 a mist air valve of the type mentioned is known. The known secondary air valve consists of a housing with an inlet opening for the secondary air flow, an outlet opening for the secondary air flow and a closure means by which the flow connection between the inlet opening and the outlet opening is blocked when the vacuum cleaner is operating undisturbed. The inlet opening for the secondary air flow consists of a simple hole through which the secondary air valve can suck in ambient air. In the area of the outlet opening, the valve housing has a connection element in the form of a connection flange made of an elastically deformable material, by means of which the Secondary air valve flow-connected, but sealed to the environment, can be attached to the suction air duct of the vacuum cleaner. The closure means consists of a piston which is arranged in the valve housing and which is tensioned against the inlet opening by a spring in a sealing manner from the inside. In the event of a pressure drop in the suction channel, the ambient pressure acting on it from the outside moves the piston away from the inlet opening against the spring force, so that the secondary air flow can flow through the inlet opening, the valve housing and the outlet opening into the suction air channel. If a vacuum cleaner equipped with such a secondary air valve has a pressure sensor, this must be installed separately in the vacuum cleaner, usually using a hose connection. This can increase the cost of construction and assembly.

In the Offenlegungsschrift DE 10 2007 040 951 A1 a vacuum cleaner is disclosed in which a pressure sensor is preassembled on the receptacle for the electrical or electronic components of the device control. The pressure sensor is used to measure the negative pressure in the suction channel upstream of the dust filter bag. In this embodiment, the plastic injection-molded receptacle forms part of the pressure channel in one piece, via which the pressure sensor is connected to the suction air channel of the vacuum cleaner. With regard to the possible arrangement of a secondary air valve, no statement is made in this document.

In the Offenlegungsschrift DE 10 2008 016 152 A1 describes a vacuum cleaner in which the housing of the secondary air valve is molded from plastic and latched onto the electrical circuit board of the vacuum cleaner by means of latching hooks. The valve housing is also coupled in a sealed manner with its outlet opening for the secondary air flow to the secondary air duct, which in turn is in flow connection with the suction duct of the vacuum cleaner.

The utility model DE 298 17 355 U1 discloses a cleaning device for flushing sanitary sewer pipes or the like, which is intended to ensure rapid and leak-free cleaning of the pipeline without impairing the function of toilet bowls or the like connected to the pipeline. The cleaning device is provided with a liquid ring pump, which is connected to a service water tank on the suction side via a connecting pipe. in the A secondary air valve and a vacuum sensor are integrated at a distance from one another in the connecting pipe. No statement is made about the specific arrangement of these components to one another.

From the disclosure document DE 42 37 150 A1 a vacuum cleaner is also known, which is equipped with a ring-shaped circumferential seal in the flow channel between the motor protection filter and the suction fan. A radially running bore is made in the seal, which opens outwards into a connection for a pressure sensor. The pressure sensor or a hose or pipe connected to it are inserted into the connection with a friction fit and sealing and are subsequently connected to the flow channel via the bore.

From the pamphlet CN 1 308 914 A a vacuum cleaner with a secondary air valve is also known, which is arranged in or on a housing of the vacuum cleaner in a flow channel of a sucked air stream. A pressure sensor is mounted on a control plate, which is also arranged on the housing of the vacuum cleaner, and extends into the air flow channel. Depending on a pressure difference determined by the pressure sensor in the air flow, the control plate controls a drive element of the secondary air valve. The secondary air valve is arranged at a distance from the control plate via an opening for the entry of external air into the sucked-in air flow.

The problem underlying the invention

The present invention is based on the object of providing a vacuum cleaner equipped with a secondary air valve and pressure sensor with a simplified structure, a reduced number of components and a simplified assembly.

Solution according to the invention

The reference signs in all claims do not have a restrictive effect, but are only intended to improve their readability.

The problem posed is achieved by a secondary air valve with the features of claim 1, a vacuum cleaner with the features of claim 2 and a method with the features of claim 11.

With regard to the secondary air valve suitable for solving the task, it is thus provided that it has a housing, an inlet opening for the secondary air flow, an outlet opening for the secondary air flow and a pressure-dependent opening closure means to block the flow connection between the inlet opening and the outlet opening having, wherein the housing is equipped with receiving means for receiving a pressure sensor.

A vacuum cleaner suitable for solving the problem with a suction nozzle, a suction fan that is flow-connected to it, a dust separation device arranged in the flow channel, a pressure sensor that is operatively connected to the flow channel and a secondary air valve for selectively feeding a secondary air flow into the flow channel is therefore characterized by the fact that the secondary air valve has a recording means is directly connected to the pressure sensor.

With regard to the assembly of the vacuum cleaner, a method is therefore suitable for solving the problem according to the invention in which the pressure sensor is first mounted on the electrical and / or electronic circuit board, then the secondary air valve is attached to the pressure sensor via the receiving means and finally the circuit board is attached to a higher-level assembly or the vacuum cleaner housing is pushed in.

By applying the invention, the number of components that are required to manufacture a vacuum cleaner provided with a secondary air valve and pressure sensor can be reduced. The overall design effort of the vacuum cleaner is reduced and the joining of the components is simplified. In particular, it is possible to reduce the length and number of hose lines or pipelines for pressure transmission within the vacuum cleaner.

Preferred embodiment of the invention

Advantageous training and further developments which can be used individually or in combination with one another are the subject of the dependent claims.

According to a first preferred embodiment of the invention, the pressure sensor is designed as a means for measuring the absolute pressure or a pressure difference. The signal determined by this pressure sensor can be forwarded to the control of the vacuum cleaner and used to reduce the power or speed of the suction fan in the event that the suction channel is caused, for example, by unintentional suction is clearly narrowed or even closed by curtains or the like. Alternatively, according to another preferred embodiment of the invention, it is contemplated that the pressure sensor is a pressure switch. A switching function can thus be carried out depending on the negative pressure in the suction channel. In both embodiments it is furthermore advantageously provided that the pressure sensor is operatively connected to a pressure display means. This can be, for example, an analog display which shows the pressure measured by the pressure sensor in the suction channel by means of a pointer on a scale. It is also conceivable that when a threshold value for the negative pressure is reached, the pressure switch generates an optical signal which, for example, indicates that the filling limit of the dust filter bag has been reached.

It is furthermore advantageously provided that the pressure sensor is flow-connected to the secondary air valve directly, that is to say without additional hoses, pipelines or the like. Attaching the secondary air valve to the pressure switch or attaching the pressure switch to the secondary air valve thus not only simplifies assembly, but also makes additional pneumatic connecting means between the two components superfluous.

An embodiment is particularly advantageous in which the receiving means is used not only for the mechanical connection between the secondary air valve and the pressure sensor, but also for a flow connection between the two components. As a result of this design, the unit comprising the secondary air valve and pressure sensor can be particularly compact. The unit of mechanical coupling and flow connection also makes it particularly easy to connect the secondary air valve to the pressure sensor in an airtight manner, so that the risk of false air being sucked in can be reduced with little structural effort.

Furthermore, it is advantageously provided that the pressure sensor is frictionally connected to the secondary air valve. The joining process, but also a later dismantling for maintenance or repair purposes, are particularly easy to carry out with this training. Furthermore, the molding of complex latching means or the like can be dispensed with, as a result of which a simplified construction of the tools required for the production of the secondary air valve and pressure sensor is possible.

With particular advantage, the receiving means comprises a conical bore in the housing of the secondary air valve or of the pressure sensor and a conical connector on the housing of the pressure sensor or of the secondary air valve. The connection of channels via a cone is particularly easy to make gas-tight and allows frictional assembly in different angular positions. Furthermore, lines of different cross-sections can also be tightly connected to one another, provided that both connecting pieces have a conicity that matches one another. In addition, the strength of the frictional connection can be adjusted individually through the inclination of the cone and the elasticity of the materials.

In principle, it is conceivable to first arrange the secondary air valve on an assembly of the vacuum cleaner, in particular the electrical and / or electronic circuit board, and then to attach the pressure sensor to the secondary air valve. However, a design in which the pressure sensor is arranged on the electrical and / or electronic circuit board of the vacuum cleaner is particularly preferred. In this way, it can be electrically connected to other electrical or electronic components located on the circuit board, for example a TRIAC used for fan control, in a particularly simple manner and without additional cabling.

With regard to the assembly of the vacuum cleaner, it is preferred that the joining direction of the pressure sensor and possibly also further electrical or electronic components on the circuit board deviates from the joining direction between the pressure sensor and the secondary air valve. An assembly process in which the joining directions run orthogonally to one another is particularly advantageous. This design enables a particularly space-saving arrangement of electrical or electronic components on the circuit board without impeding a compact arrangement and the subsequent joining of the secondary air valve.

With the invention, the number of components that are required for manufacturing the vacuum cleaner provided with a secondary air valve and pressure sensor can be reduced. As a result, the overall design effort of the vacuum cleaner is reduced and the joining of the components is simplified. In particular, it is possible to reduce the length and number of hose lines or pipelines for pressure transmission within the vacuum cleaner.

Brief description of the drawings

Fig. 1

die Darstellung eines erfindungsgemäß ausgestatteten Bodenstaubsaugers;

Fig. 2

ein Nebenluftventil mit angeschlossenem Drucksensor nach einer ersten Ausführung der Erfindung;

und schließlich

Fig. 3

ein Nebenluftventil mit angeschlossenem Drucksensor nach einer weiteren Ausführung der Erfindung;

Further advantageous configurations are described in more detail below with reference to two exemplary embodiments shown in the drawings, to which the invention is not limited, however.
They show schematically:

Fig. 1

the representation of a cylinder vacuum cleaner equipped according to the invention;

Fig. 2

a secondary air valve with an attached pressure sensor according to a first embodiment of the invention;

and finally

Fig. 3

a secondary air valve with an attached pressure sensor according to a further embodiment of the invention;

Detailed description based on two exemplary embodiments

In the following description of two preferred embodiments of the present invention, the same reference symbols designate the same or comparable components.

The in Fig. 1 illustrated vacuum cleaner 1 is designed as a cylinder vacuum cleaner. In principle, however, the invention can also be used with advantage in other designs, for example a stick vacuum cleaner.

The vacuum cleaner 1 after Fig. 1 consists of a separate subframe 2, which is equipped with a chassis 3 and can therefore be moved comfortably over the floor surface to be cleaned. The housing 4 of the subframe 2 accommodates in particular a suction fan 5 and a dust separation device 6 in the form of a dust filter bag 7. Further, not shown components of the subframe are, for example, a windable power cable for electrical connection with a Power supply, control devices for switching on and power setting, electronic control devices and a storage compartment for accessories such as suction brushes or the like.

Upstream of the dust separation device 6 there is a connection 8 for attaching a flexible suction hose 9, which in turn is flow-connected to a telescopic push tube 10. The thrust tube 10 is pushed into a connection piece 11 of the suction nozzle 12 in a sealed manner. Upstream of the connecting piece 11, the suction nozzle 12 has a suction nozzle housing 13 and a sliding base 14 with a suction mouth 15 to be guided over the floor surface to be cleaned. The suction nozzle 12 is also provided with a roller arrangement 16 for supporting the thrust tube 10.

During the cleaning process, the sliding sole 14 lies against the floor surface in a sealing manner, with an air stream being sucked in by the negative pressure applied to the suction mouth 15 and the dust on the floor surface being carried along with it. The air flow carrying dirt is passed through the thrust tube 10 and the suction hose 9 into the dust separating device 6, where the dust is separated out in the dust filter bag 7. The pre-cleaned air flow then passes through a motor protection filter 17 in order to also separate out particularly fine dust particles. The now cleaned air flow passes through the suction fan 5 and is then discharged into the environment through an opening 18 in the housing 4 of the unit carrier 2.

In the subframe 2 there is also a controller 19 with a printed circuit board 20 which, in addition to other electrical and electronic components, also carries a pressure sensor 21 and is operatively connected to the suction fan 5 and other components such as switches and setting devices. Directly mechanically and fluidically connected to the pressure sensor 21 is a secondary air valve 22 which can communicate on the inlet side with the environment and on the outlet side with the dust separation device 6.

How out Fig. 2 As can be seen, the secondary air valve 22 has a housing 23 with an inlet opening 24 for the incoming secondary air flow and an outlet opening 25 for the exiting secondary air flow. The outlet opening 25 is in a manner not shown upstream of the suction fan 5 with the suction channel, for example the Dust separation device 6, fluidly connected. A closure means 26 is arranged in the housing 23 of the secondary air valve 22 downstream of the inlet opening 24 and is pressed by a spring 27 in a sealing manner against the wall of the housing 23 surrounding the inlet opening. As soon as the pressure at the outlet opening 25 falls below a value defined by the force of the spring 27 and the effective area of the closing means 26 due to a closure of the suction nozzle 12, the closing means 26 is lifted from the housing 23 and opens the inlet opening 24. The secondary air flow sucked in as a result is passed on into the suction channel and prevents the suction fan 5 from overheating.

The secondary air valve 22 is mechanically connected to the pressure sensor 21 arranged on the circuit board 20 by a receiving means 28. The connection is frictionally engaged by a connector 29 on the pressure sensor 21 that tapers conically towards the outside and is inserted into a complementary conical bore 30 in the housing 23 of the secondary air valve 22. Since the connector 29 is pierced, it simultaneously forms a channel 30 for the flow connection between the pressure sensor 21 and the secondary air valve 22.

The pressure sensor 21 and further electrical or electronic components of the controller 29, for example a TRIAC 32, are placed on the printed circuit board 20 perpendicularly to the extent of the printed circuit board (arrow A). In this case, contacts 33 are inserted through recesses in the printed circuit board 20 and soldered to the rear conductor tracks. Alternatively, the conductor tracks can also be arranged on the upper side of the circuit board 20, with the electrical or electronic components being soldered directly to it. The longitudinal axis of the connector 29 of the pressure sensor 21 extends parallel to the surface side of the printed circuit board 20 beyond this, so that the joining of the secondary air valve 22 takes place in a direction (arrow B) deviating from arrow A, namely orthogonal thereto. The assembly of the secondary air valve 22 is thus not hindered either by the pressure sensor 21 already preassembled on the circuit board 20 or by other electrical or electronic components arranged there.

In the embodiment according to Fig. 3 the secondary air valve 22 is connected both mechanically and fluidically to the dust separation device 6 via a rigid pipe section 34. The housing 23 of the secondary air valve 22 is provided with upwardly projecting receiving means 28 in the form of latching hooks 35 which, after assembly, comprise a mushroom-like counterpart 36 on the pressure sensor 21. The channel 31 for the flow connection between the secondary air valve 22 and the pressure sensor 21 is arranged on the other side of the receiving means 28 and is sealed airtight by a separate ring seal 37.

By applying the invention, the number of components that are required to manufacture a vacuum cleaner provided with a secondary air valve and pressure sensor can be reduced. The overall design effort of the vacuum cleaner is reduced and the joining of the components is simplified. In particular, it is possible to reduce the length and number of hose lines and pipelines for pressure transmission within the vacuum cleaner.

The features disclosed in the above description, the claims and the drawings can be important both individually and in any combination for the implementation of the invention in its various configurations.

List of reference symbols

1

vacuum cleaner

2

Subframe

3

landing gear

4th

casing

5

Suction fan

6th

Dust separator

7th

Dust filter bag

8th

connection

9

Suction hose

10

Thrust tube

11

Connection piece

12th

Suction nozzle

13th

Suction nozzle housing

14th

Sliding sole

15th

Suction mouth

16

Roller arrangement

17th

Motor protection filter

18th

opening

19th

control

20th

Circuit board

21

Pressure sensor

22nd

Secondary air valve

23

casing

24

Inlet opening

25th

Outlet opening

26th

Closure means

27

feather

28

Receiving means

29

Support

30th

drilling

31

channel

32

TRIAC

33

Contact

34

Pipe section

35

Locking hook

36

Counterpart

37

Ring seal

Claims (13)

1. Auxiliary air valve (22) for a vacuum cleaner (1), with a housing (23), an inlet opening (24) for the auxiliary air current, an outlet opening (25) for the auxiliary air current and a closure means (29) that opens on a pressure-dependent basis for blocking the flow connection between inlet opening (24) and outlet opening (25),
   wherein the housing (23) of the auxiliary air valve (22) is equipped with receiving means (28) for receiving a pressure sensor (21).
2. Vacuum cleaner (1) with a suction nozzle (12), a suction fan (5) connected thereto for flow purposes, a dust separating facility (6) arranged in the flow channel, a pressure sensor (21) actively connected to the suction channel and an auxiliary air valve (22) according to claim 1 for selectively injecting an auxiliary air current into the suction channel,
   characterised in that
   the auxiliary air valve (22) is directly connected to the pressure sensor (21) via the receiving means (28).
3. Vacuum cleaner according to claim 2, characterised in that the pressure sensor (21) is a means for measuring the absolute pressure or a pressure difference.
4. Vacuum cleaner according to claim 2, characterised in that the pressure sensor (21) is a pressure switch.
5. Vacuum cleaner according to one of claims 2 to 4, characterised in that the pressure sensor (21) is actively connected to a pressure indicating means.
6. Vacuum cleaner according to one of claims 2 to 5, characterised in that the pressure sensor (21) is directly connected to the auxiliary air valve (22) for flow purposes.
7. Vacuum cleaner according to claim 6, characterised in that the flow connection takes place by way of the receiving means (28).
8. Vacuum cleaner according to one of claims 2 to 7, characterised in that the pressure sensor (21) is connected to the auxiliary air valve (22) with a friction fit.
9. Vacuum cleaner according to claim 7 or 8, characterised in that the receiving means (28) comprises a cone-shaped bore hole (30) in the housing of the auxiliary air valve (22) or of the pressure sensor (21), as well as a cone-shaped connecting piece (29) on the housing of the pressure sensor (21) or of the auxiliary air valve (22).
10. Vacuum cleaner according to one of claims 2 to 9, characterised in that the pressure sensor (21) is arranged on the electrical and/or electronic circuit board (20) of the vacuum cleaner (1).
11. Method for assembling a vacuum cleaner (1) according to claim 10, characterised in that first the pressure sensor (21) is assembled on the electrical and/or electronic circuit board (20), subsequently auxiliary air valve (22) is fastened to the pressure sensor (21) via the receiving means (28) and finally the circuit board (20) is inserted into a higher-level module or the vacuum cleaner housing.
12. Method according to claim 11, characterised in that the joining direction of the pressure sensor (21) onto the circuit board (20) deviates from the joining direction between pressure sensor (21) and auxiliary air valve (22).
13. Method according to claim 12, characterised in that the joining direction of the pressure sensor (21) onto the circuit board (20) runs orthogonally to the joining direction between pressure sensor (21) and auxiliary air valve (22).

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