EP2612582B1 - Vacuum cleaner and method for operating same - Google Patents

Description

The invention relates to a vacuum cleaner with a designed as an axial fan suction fan and a dust chamber in which a filter is arranged, by means of a reversal of rotation of the suction fan a direction of a suction fan caused by the air flow through the filter is reversible. It further relates to a method of operating a vacuum cleaner.

Such vacuum cleaners are known. For example, in the WO 00/54644 describes a dust container for a vacuum cleaner, from which the dust is blown by reversing the direction of rotation of an axial blower in a collecting container. Prior to this emptying procedure, the user must couple the dust container to the collection container and activate the purging of the dust from the dust container.

Vacuum cleaners are also known in which the user manually shakes the filter by means of a mechanism for cleaning. A disadvantage of these vacuum cleaners, however, is that this only a very small filter cleaning can be achieved. The user must actively activate the filter cleaning. The mechanics cause additional costs and space required. Even devices that do not have such a mechanism are disadvantageous because the user has to do the filter cleaning manually. This is often very unhygienic. During cleaning of the filter by means of a mechanism as well as during manual filter cleaning, the user may be exposed to respiratory loads due to the swirling up of fine dust. In order to be able to suck for a sufficiently long time without suction loss, either a relatively large filter surface is required, or the user must clean the filter frequently.

From the WO A 2004/100746 Vacuum cleaners are known in which the device for cleaning a filter via a pressure sensor is automatically controlled or can be connected via an operating element by the user. The use of a sensor for controlling the cleaning device is disadvantageous, since the technical complexity increases, additional space is needed and increase the cost to a significant extent. The manual control of the cleaning device via an operating element has the disadvantage that the operator must operate the cleaning device independently at regular intervals. If operators forego regular operation of the cleaning device due to the additional expense, this can lead to the filter becoming contaminated with dirt particles as a result of which the efficiency of the vacuum cleaner is reduced to a significant extent.

The invention is therefore an object of the invention to provide a vacuum cleaner, which is inexpensive and in which the filter can be cleaned in a hygienic manner.

This object is achieved with the features of claim 1. For this purpose, in a vacuum cleaner with a designed as an axial fan suction fan and a dust chamber in which a filter is arranged, by means of a reversal of rotation of the suction fan a direction of a suction fan caused by the air flow, so a suction air flow is reversible through the filter, a control electronics for automatically reversing the direction of air flow through the filter following a suction process. The reversal thus takes place after each suction application, that is to say after the end of the suction process by the user.

The advantage of the invention is that a fully automatic hygienic filter cleaning is made possible at the end of each suction application. Such a trained vacuum cleaner is also cost-neutral, since no additional components must be used. The regular filter cleaning allows the use of filters with a relatively small filter area, which can save costs.

Advantageous embodiments of the invention are the subject of the dependent claims. Relationships used in subclaims indicate the further development of the subject of the main claim by the features of the respective subclaim; they may also contain independent inventions having a design independent of the objects of the preceding claims and are not to be understood as a waiver of the achievement of independent, objective protection for their characteristics. Furthermore, with a view to an interpretation of the claims in a closer specification of a feature in a subordinate claim, it is to be assumed that such a restriction does not exist in the respective preceding claims.

Optionally, in the vacuum cleaner, e.g. provided as functionality of the control electronics, a predetermined or predeterminable time value for establishing a time interval between an end of the suction process and the rotation direction reversal subsequently automatically effected. An impeller of the axial fan can be braked after switching off the vacuum cleaner or unrestrained until it stops. Thereafter, for example, a break, e.g. of two seconds, follow. The duration of the break is through the o.g. Time value determined. Subsequently, the axial fan, driven by the control electronics, automatically run in the opposite direction. The time value may be in the drive electronics e.g. implemented in hardware, e.g. as the time constant of an RC element, or in software, e.g. as the content of a corresponding memory cell.

Preferably, a predetermined or predeterminable further time value is provided for determining a duration of the reversal of the direction of rotation. This determines how long the filter will be cleaned. The duration of reversal of the direction of rotation subsequent to the suction process can generally be kept relatively short since, if the filter is automatically cleaned after each suction, only little dirt adheres to it. A possible time value for the duration of the reversal of the direction of rotation is, for example, one or two seconds, ie a short speed or flow pulse, but also any other time value is possible. This time value can also be implemented in hardware, for example as described above, eg as a time constant of an RC element, or in software, eg as the content of a corresponding memory cell.

Preferably, a speed of the suction fan in the reverse air flow direction may be lower than during the suction process. Even a weak blast air flow is usually sufficient to effectively clean the filter. At the same time, energy is saved because the axial fan does not have to be operated at high power.

When the vacuum cleaner comprises a suction passage downstream of a suction air flow in front of the dust chamber and a valve opening in a suction air flow blocking the suction passage in a blast air flow, it is ensured that the dust dissolving from the filter through the blown air flow does not exceed the suction air flow Suction channel is transported from the dust chamber. This prevents the user from standing in a cloud of dust when cleaning the filter. Instead, the dust released from the filter remains in the dust space, and may be stopped as needed after completion of the cleaning operation of the filter, e.g. be disposed of by manually draining / dumping the dust space by the user in an uncomplicated manner at a suitable location.

Preferably, a motor driving the suction fan is designed as a brushless permanent magnet motor. This allows a good engine life with a speed of at least 70,000 revolutions per minute. Such a speed is advantageous for an axial fan to achieve good fan efficiencies. In combination with a corresponding control electronics brushless permanent magnet motors are also energy efficient. More preferably, the brushless permanent magnet motor can be provided in internal rotor design, whereby the demands placed on him are met particularly well.

The vacuum cleaner is especially suitable for use as a table vacuum cleaner. Additionally or alternatively, for the vacuum cleaner is a version as a vacuum cleaner into consideration.

With regard to the method, the o.g. Problem solved according to the invention by the features of the corresponding method claim. This is in a method for operating a vacuum cleaner with one or more of the o.g. Provision is made for automatically reversing a direction of the air flow through the filter following a suction process by means of an activation of the suction fan caused by the control electronics. Following a suction process means after completion of the suction process by the user.

An embodiment of the invention will be explained in more detail with reference to the drawing. Corresponding objects or elements are provided in all figures with the same reference numerals. The or each embodiment is not to be understood as limiting the invention. Rather, in the context of the present It is possible to disclose numerous changes and modifications, in particular those variants, which may be made, for example, by combination or modification of individual features or elements or method steps described in the general description, the or each embodiment and the claims, and in the drawings Skilled in terms of solving the problem are removable and lead by combinable features to a new object or to new process steps or process steps.

Figur 1

eine schematische Darstellung eines Staubsaugers gemäß einem Ausführungsbeispiel der vorliegenden Erfindung,

Figur 2

einen zeitlichen Verlauf eines Saugvorgangs mit dem Staubsauger aus Figur 1 und

Figur 3

ein schematisch vereinfachtes Flussdiagramm eines Verfahrens zum Betrieb eines erfindungsgemäßen Staubsaugers.

Show it

FIG. 1

a schematic representation of a vacuum cleaner according to an embodiment of the present invention,

FIG. 2

a temporal course of a suction process with the vacuum cleaner FIG. 1 and

FIG. 3

a schematically simplified flowchart of a method for operating a vacuum cleaner according to the invention.

FIG. 1 schematically shows a simplified vacuum cleaner 10 with a suction fan 12, which is designed as an axial fan, consisting of a motor 14 and a blower unit 16 with an axial impeller 18. The suction fan 12 causes during a suction process 20 (FIG. FIG. 2 ) an air flow 22 (shown simplified by an arrow) through a suction port 24, a dust chamber 26 and a filter 28, such as a fine dust filter, which exits at a rear of the vacuum cleaner 10 through blow-out slots (not shown) from the vacuum cleaner 10 again. In this case, dust and dirt particles 30 are sucked in and retained with the filter 28. In the following, this air flow 22 is also referred to as suction air flow. As the suction time increases, especially particulate matter 32 pollutes the filter 28 and blocks it, so that a suction volume flow decreases. Therefore, in the present invention, the direction of the air flow through the filter 28 is automatically reversed following the suction process. Following the suction is called after completion of the suction by the user, ie after switching off the Suction fan 12 via a main switch 52. The air flow in the reverse direction to the suction air flow (opposite to the arrow) is hereinafter sometimes referred to as Blasluftstrom.

Between a battery 34 of the vacuum cleaner 10, which is designed in this embodiment as a vacuum cleaner, and the motor 14, a control electronics 36 is arranged, which converts the direct current from the battery 34 into a current required for driving the motor 14, in particular three-phase current. For this purpose, the control electronics 36, for example, a correspondingly suitable microprocessor (not shown).

The speed and direction of rotation of the motor 14 can be adjusted via the voltage and the rotational frequency. The direction of rotation of the motor 14 determines the direction of rotation of the axial impeller 18 of the suction fan 12 and thus the direction of the air flow through the filter 28. A height and a time course of the engine speed or the direction of rotation, i. For example, a rotational speed of the motor 14 during the suction process 20, a rotational speed of the motor 14 at opposite to suction 20 rotational direction of the motor 14 and the Axiallaufrads 18, a time value corresponding to a duration during which the suction fan 12 in the suction opposite direction is operated, and a time value corresponding to a period of time which is in the opposite direction between one end of the suction process and a control of the suction fan 12, as set values in the control electronics 36, eg in a memory (not shown) of the control electronics, be kept available retrievable. In this way, the control electronics 36 allows a cost-neutral processor-controlled reversal without additional components such as relays or the like. Alternatively, at least the above-stated time values may also be used in hardware, e.g. be implemented as the time constant of an RC element.

The motor 14 is a brushless permanent magnet motor. This allows operation at a speed of 70,000 or more revolutions per minute with acceptable life. A speed of 70,000 or more revolutions per minute is advantageous in order to achieve a suitable blower efficiency. The brushless permanent magnet motor can also be designed with an internal rotor, thus fulfilling its requirements particularly well.

The vacuum cleaner 10 may additionally include a valve (not shown). This is e.g. arranged in a region between the suction opening 24 and the filter 28, that is, for example, in the dust chamber 26 or in a suction channel, which is located downstream of the suction air flow in front of the dust chamber 26. The valve blocks the suction channel or the suction opening 24 in the case of a blast air flow, so that fine dust particles 32, which detach from the filter 28, or else dust and dirt particles 30 which are located in the dust chamber 26, are not conveyed out through the suction opening 24 ,

FIG. 2 shows a time course 38, in which on the abscissa the time in seconds and on the ordinate the fan speed per minute is plotted. Positive blower speeds represent a suction process 20. Following the suction process 20, the direction of rotation of the suction fan 12 is reversed, by which a direction of the air flow 22 caused by the suction fan 12 is reversed. That is, the suction air flow effected during the suction process 20 becomes subsequent to the suction process 20 automatically reversed into a blast air stream. This exposes the filter 28 ( FIG. 1 ) a cleaning automatically.

After switching on the suction fan 12 ( FIG. 1 ), ie after the user has switched on the vacuum cleaner 10, the axial impeller 18 rotates at 70,000 revolutions per minute during the entire suction process 20 after approximately two seconds. The time interval between the end of the suction process 20 and that subsequently effected automatically Direction of rotation reversal is determined by a given or predefinable time value. After switching off by the user, the axial impeller 18 runs depending on the design of the control electronics 36 (FIG. FIG. 1 ) either braked or unrestrained to a stop. This time is to be regarded as the end of the suction process 20. Thereafter, as a time interval between the end of the suction process 20 and the reversal of the direction of rotation, a pause 40 from here for about two seconds is given, at which the fan speed is 0 revolutions per minute. The suction fan 12 is then driven by the microprocessor of the control electronics 36 for a predetermined or predetermined further time value of about one second for a filter cleaning operation 42, represented by negative fan speeds, in the opposite direction, ie the axial impeller 18 rotates in the opposite direction, so that no air through the dust chamber 26 ( FIG. 1 ) is sucked, but a blast of air is blown from behind through the blow-out in the reverse direction through the filter 28. Within this short period of time, the filter 28 is separated from the dirt and dust particles accumulated during the suction process 20, in particular fine dust particles 32 (FIG. FIG. 1 ), so that the full suction power is available for the next suction process. For this purpose, only a short speed or flow impulse is required, which only takes up little of the battery capacity of the vacuum cleaner 10. In addition, the speed during the filter cleaning process 42 with, for example, about 50,000 revolutions per minute lower than during the suction process 20th

The dust and dirt particles, in particular fine dust particles 32, which are dissolved by the filter 28 accumulate in the dust space 26 and can be hygienically removed therefrom, if necessary, e.g. by emptying into a corresponding container.

FIG. 3 1 shows a schematically simplified flowchart for explaining a method 44 for operating the vacuum cleaner 10. In a first step 46, after an end of a suction process 20 (FIG. FIG. 2 ) via the control electronics 36 ( FIG. 1 ) a predetermined or predeterminable time value, for example, retrieved from the memory of the control electronics 36 and processed in a microprocessor. Within the time interval determined by the time value, the suction fan 12 (FIG. FIG. 1 ) not driven. This time value corresponds to the duration of a break 40 ( FIG. 2 ) between the suction process 20 and the filter cleaning process 42 ( FIG. 2 ). In a second step 48, a further predetermined or predeterminable time value is retrieved from a memory and, after the break 40, the suction fan 12 is triggered for this further time value, ie for a duration corresponding to this time value, in the direction opposite to the suction process 20. This further time value corresponds to the duration of the filter cleaning process 42. In a third step 50, the suction fan 12 is stopped by the control electronics 36 until the vacuum cleaner 10 is turned on again by a user.

Thus, the invention can be briefly illustrated as follows: It is a vacuum cleaner 10 with a designed as axial fan suction fan 12 and a dust chamber 26, in which a filter 28 is arranged, wherein by means of a reversal of rotation of the suction fan 12, a direction caused by the suction fan 12 Air flow 22 through the filter 28 is reversible, indicated that includes a control electronics 36 for automatically reversing the direction of the air flow 22 through the filter 28 following a suction 20.

LIST OF REFERENCE NUMBERS

10

vacuum cleaner

12

suction blower

14

engine

16

blower unit

18

axial impeller

20

suction

22

airflow

24

suction opening

26

dust chamber

28

filter

30

Dust and dirt particles

32

particulate matter

34

battery pack

36

control electronics

38

time course

40

Break

42

Filter cleaning operation

44

method

46

first step

48

second step

50

Third step

52

main switch

Claims (8)

1. Vacuum cleaner (10) comprising a suction fan (12) designed as an axial fan and a dust chamber (26) in which a filter (28) is arranged,
   it being possible for a direction of an air flow (22) through the filter (28) brought about by the suction fan (12) to be reversed by reversing the direction of rotation of the suction fan (12), the vacuum cleaner having a control electronics (36) for automatically reversing the direction of the air flow (22) through the filter (28) following a suction process (20),
   characterised by a time value, which is or can be predetermined, for setting a time interval (40) between an end of the suction process (20) and the reversal of the direction of rotation which is brought about automatically thereafter.
2. Vacuum cleaner (10) according to either claim 1 or claim 2, comprising an additional time value, which is or can be predetermined, for setting a duration of the reversal of the direction of rotation.
3. Vacuum cleaner (10) according to any of claims 1 to 3, wherein a speed of the suction fan (12) is lower when the air flow direction (22) is reversed than during the suction process (20).
4. Vacuum cleaner (10) according to any of claims 1 to 4, comprising a suction channel located in front of the dust chamber (26) downstream of a suction air flow, and a valve which is arranged therein, which opens upon a suction air flow and closes the suction channel during a blowing air flow.
5. Vacuum cleaner (10) according to any of claims 1 to 5, wherein a motor (14) driving the suction fan (12) is designed as a brushless permanent magnet motor.
6. Vacuum cleaner (10) according to any of claims 1 to 6, wherein the vacuum cleaner (10) is designed as a handheld vacuum cleaner.
7. Vacuum cleaner (10) according to claim 7, wherein the vacuum cleaner (10) is designed as a rechargeable vacuum cleaner.
8. Method for operating a vacuum cleaner according to any of the preceding claims, wherein a direction of the air flow through the filter (28) is reversed automatically following a suction process (20) as a result of an actuation of the suction fan (12) by the control electronics (36).

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