EP2875767B1 - Vacuum cleaner and method for operating same - Google Patents

Description

Field of the invention

The invention relates to a method for operating a vacuum cleaner, comprising a blower motor having a blower, which generates an air flow through a suction nozzle of the vacuum cleaner. Furthermore, a control device of the vacuum cleaner controls the fan depending on a floor covering category to be processed. The invention further relates to a vacuum cleaner.

Background of the invention

Vacuum cleaners can be used to clean different floor coverings, but often the requirements for the vacuum cleaner vary depending on the floor covering. In order to meet such different requirements, manual adjustment options for the engine power for driving a fan in the vacuum cleaner are provided in the prior art, for example. This manual power adjustment is generally made by a user of the vacuum cleaner due to the noise of the vacuum cleaner or other individual and subjective impressions. The manual power adjustment may therefore not meet the goal in such vacuum cleaners to achieve a high dust absorption or to achieve an objectively good cleaning result.

In addition, vacuum cleaners are known which can automatically control the performance of the fan motor. This is how the publication describes DE 10 2010 031 572 A1 a device and a method for controlling the performance of a blower motor for a vacuum cleaner, which should ensure a substantially consistently high energy efficiency, regardless of the floor covering on which the vacuum cleaner is operated. For this purpose, a pressure sensor system for detecting a differential pressure is provided between a first region lying in the suction flow direction before the replaceable filter bag and a second region lying in the suction flow direction after the replaceable filter bag. A control unit controls the power of the fan motor as a function of the detected pressure difference but independent of the negative pressure in the first area.

The patent DE 43 04 263 C1 describes a suction device and associated control method. A pressure sensor detects an actual suction pressure in the suction area of the vacuum cleaner and compares it with a target suction pressure at a cold junction to determine an error signal. Based on this error signal, a triac is controlled to control the power of the motor. In addition, a particular advantage of the method is that a low noise level is made possible by an envisaged standby position of the engine.

The publication DE 10 2007 025 389 A1 discloses a method for operating a vacuum cleaner in which a sensor determines the type of flooring to be processed in a "noise control" operation and a control device depending on the determined floor covering the engine power or influencing the engine performance parameters such that a adjusts the floor covering dependent air flow value. For this purpose, the control electronics can assign the flooring to one of the categories "Wilton", "Duracord" and "smooth floor", which in turn are assigned to be reached reference flow values for which result due to a floor covering dependent load curve and a performance-dependent fan characteristic associated engine performance. The method should have a favorable effect on the operating noise of the vacuum cleaner determined by the air flow.

Another pamphlet EP 2617340 A2 discloses a device and a method for controlling the engine power of a vacuum cleaner, in particular for controlling the engine power as a function of a level of a dust collector. In this case, the device for influencing an electrical power consumption of a vacuum cleaner motor of a vacuum cleaner with a suction air flow (13) can be arranged dust collecting means for detecting a pressure difference between a first Saugluftdruck upstream of the dust collector and a second Saugluftdruck downstream of the dust collector and a device for Adjusting the electrical power consumption of the vacuum cleaner motor when the detected pressure difference exceeds or falls below a preset differential pressure threshold.

The publication DE 10 2005 044 617 A1 discloses a method for grooming and / or cleaning a floor covering with a floor care and / or cleaning appliance. The device has means for identifying the type and / or condition of the floor covering. For this purpose, reading means are arranged in the device which read the nature and / or nature of the floor covering from information carriers integrated in the floor covering. By means of an electronic control system parameters such as a suction power or a brush speed of a cleaning brush arranged in the device can then be adapted with regard to the floor covering to be cleaned.

The patent DE 10 2007 011 381 B3 teaches a method for sensorless detection of a floor covering for a vacuum cleaner, the fan of which has an electronically commutated motor. Current parameters such as speed, motor current or switching angle can be read out from the motor, which in turn can be used to calculate the parameters of the fan, such as the negative pressure and the flow rate. These parameters can be compared in a control electronics with reference sizes, whereby at least two different floor coverings can be identified.

From the publication DE 10 2010 000 573 A1 For example, a method for controlling the power of a fan and a brush drive of an electrically driven suction / sweeping device is known. Floor sensors in the device serve to detect the floor covering. Depending on the floor covering detected, a controller can vary the performance of the fan and brush so that the total power consumption in the unit remains constant regardless of the fan and brush power consumption.

The translation of the European patent specification DE 698 32 957 T2 discloses an electrical surface treatment device having an acoustic detector for detecting a surface material to be treated. By means of the detector it is possible to distinguish not only between hard, smooth floors and a carpet, but also between different types of smooth floors and between different types of carpets. The detector provides an output signal that is characteristic of the surface material to be cleaned. A suction force of a suction unit and a speed of a brush may be controlled by a controller as a function of the output signal.

The publication DE 10 2008 061 251 A1 discloses an electric vacuum cleaner and a method of operating it. The vacuum cleaner has means that allow to adjust the suction power of the vacuum cleaner depending on a connected vacuum cleaner nozzle. Detection of the vacuum cleaner nozzle can be automatic or manual.

A control device with two control circuits and two pressure sensors is in the published patent application DE 10 2007 057 589 A1 disclosed. A first control loop can adjust the power at the motor / blower unit when changing the floor covering to be cleaned, in which also the flow resistance and thus the negative pressure applied to the first pressure sensor changes, such that the force required to displace the suction nozzle on the surface to be cleaned stays below a threshold. With a second control circuit, the suction power can be made independent of the degree of filling of a Staubabscheideeinheit by controlling the fan speed. For this purpose, the negative pressure, measured between fan and dust bag, adjusted between an upper and a lower threshold. The publication DE 10 2008 010 068 A1 discloses a similar device for a vacuum cleaner, which also has two pressure sensors and two control circuits.

Another control device with at least two sensors teaches the published patent application DE 10 2012 200 765 A1 , In one embodiment, a differential pressure is determined by two pressure sensors, which are arranged in the suction flow direction before and after the dust bag. The differential pressure makes it possible to draw conclusions about the degree of filling of the dust bag. Depending on the specific filling level of the dust bag, the fan motor power is increased in two or more stages so that the air flow remains above a minimum value.

The problem underlying the invention

The invention has for its object to provide an improved method for operating a vacuum cleaner. In particular, the total absorption capacity of the vacuum cleaner should be reduced with the least possible impairment of the dust absorption. Furthermore, it should in particular be possible to provide a sufficient cleaning performance over the period of use of a dust bag or a Staubabscheideeinheit the vacuum cleaner or until the complete filling of the dust bag or Staubabscheideeinheit available. It is another object of the present invention to provide a vacuum cleaner which can be operated by this method.

Inventive solution

The solution of the object is achieved by a method for operating a vacuum cleaner having a blower motor equipped with a blower, which generates an air flow through a suction nozzle of the vacuum cleaner. A control device of the vacuum cleaner controls the fan depending on a floor covering category to be processed. In the method according to the invention, the vacuum cleaner is set up for processing at least one first floor covering category and a second floor covering category, the floor covering category is signaled to the control device, and the floor covering of the category for which the vacuum cleaner is set up is processed. The control device controls a power consumption of the fan motor on the basis of the signaled flooring category such that when the first flooring category is being processed, both a first fan power and a first airflow are higher than in the second floor category processing a second, and thus lower fan power, and a second, also lower fan speed air flow. The first category of flooring is associated with floor coverings which, when processed with the suction nozzle, have a flow resistance greater than that which floor coverings have when processing with the suction nozzle assigned to the second floor covering category and / or the first floor covering category are carpets and the second Hard floor coverings assigned.

The solution of the problem also succeeds with a vacuum cleaner with a blower motor having a blower for generating an air flow through a suction nozzle of the vacuum cleaner. The vacuum cleaner according to the invention further comprises a recognition device for signaling a category of the floor covering to be processed from a category group comprising at least a first floor covering category and a second floor covering category, to a control device for controlling the blower, the control device being functionally connected to the detection device, around the suction blower depending on a signaled flooring category. The control device can control a power consumption of the fan motor on the basis of the signaled floor covering category in such a way that during the processing of the first Flooring category both the first blower output and a first air flow are higher than when processing the second floor covering category with a second blower output and a second air flow. The first flooring category is associated with floor coverings which, when machined with the suction nozzle, have a flow resistance greater than that exhibited by floor coverings when processed with the suction nozzle associated with the second floor covering category and / or the first flooring category are carpets and the second Hard floor coverings assigned.

Among other things, the invention exploits the inventors' surprising finding that floor coverings exist in which the dust absorption of a vacuum cleaner still remains within an acceptable range, when the blower output is reduced so far compared to the blower output required for other floor coverings, that even the air flow less than the other floor coverings.

Due to the inventively lower fan performance in the processing of the second flooring, the average total fan power when considering a treatment of both flooring categories is advantageously lower than a treatment of the second flooring category with the same fan performance as in the processing of the first floor covering category. Thus, the inventive method can advantageously lead to low energy consumption in vacuum cleaners. This advantage can be generally described by the following formula for the average total power consumption of a vacuum cleaner: $$\mathrm{Total\; input\; power}\mathrm{one}\mathrm{vacuum\; cleaner}\mathrm{at}\mathrm{one}\mathrm{processing}\mathrm{one}\mathrm{first}\mathrm{and}\mathrm{zweitein}\mathrm{flooring}=\left(\mathrm{power\; consumption}\mathrm{at}\mathrm{one}\mathrm{processing}\mathrm{one}\mathrm{first}\mathrm{flooring}+\mathrm{power\; consumption}\mathrm{at}\mathrm{one}\mathrm{processing}\mathrm{one}\mathrm{second}\mathrm{flooring}\right)/2$$

As a result, compared to a vacuum cleaner which processes both floor categories with the same fan power, the input power in the processing of the first floor covering can be increased to the extent that it is reduced during the processing of the second floor covering, without thereby reducing the total absorption capacity of the first floor covering Vacuum cleaner increased. Thus, the dust absorption in the first floor category can be advantageously increased without the total absorption capacity increases.

For the purposes of the present invention, the blower output is the electrical input power, ie the electrical power consumption of the motor which drives the blower. In particular, it does not mean the fan output, that is, the power that is transmitted, for example, from a fan motor to a fluid flow. However, in preferred embodiments of the invention, the relationship applicable to the blower output may also apply to the blower output.

The suction nozzle according to the invention is a section of the vacuum cleaner with the aid of which a floor covering is processed. The suction nozzle can be in direct contact with the floor covering. The suction nozzle may be releasably or non-releasably attached to a pipe or hose. The tube and / or hose may be connected to a dust bag or a collection container, e.g. a Staubabscheideeinheit be connected in the vacuum cleaner. The suction nozzle may have flow-optimized suction channels for a negative pressure, wherein the negative pressure is generated by the blower.

For the purposes of the invention, the term vacuum cleaner includes all types of vacuum cleaners, including canister vacuum cleaners, stick vacuum cleaners, vacuum cleaners and upright vacuum cleaners. The vacuum cleaner may be a dry and / or a wet vacuum cleaner and may be provided with either dust bags or bagless, e.g. work according to the Wirbelabscheideverfahren with a Staubabscheideeinheit.

A floor covering in the sense of the present invention is preferably an area that is usually entered by persons with their feet, so for example a concrete or a parquet floor, one with plates, e.g. Slabs or ceramic slabs or a floor slab, e.g. a carpet, felt, or elastic polymer such as neoprene covered floor. However, in the context of the invention, the word "floor covering" shall be understood to mean that it also covers other surfaces that can be worked with a vacuum cleaner, e.g. Furniture surfaces such as upholstered surfaces, cabinet, chair and table surfaces includes. The flooring may be indoors or outdoors.

A minimum air flow means an air flow through the suction nozzle of the vacuum cleaner, which is at least necessary to provide a minimum vacuum when processing a floor covering to achieve a minimum cleaning performance. A minimum cleaning performance is typically given for a universal suction nozzle, if a dust absorption of 70% for carpets or a dust absorption of 95% for hard floors is achievable. These values correspond to the minimum requirements of the EU energy label for vacuum cleaners, which was introduced on 1 September 2014. Typical minimum air flows then for example 15 l / s or 20 l / s, and may depend on a fan characteristic or a load characteristic of the vacuum cleaner.

Preferred embodiment of the invention

Advantageous embodiments and developments, which can be used individually or in combination with each other, are the subject of the dependent claims.

In a preferred embodiment of the method according to the invention, the second blower output is at least 10%, more preferably at least 15% lower than the first blower output. However, the second blower power may also be more than 15% below the first blower power, for example at least 20%, at least 25%, at least 30%, at least 40%, at least 50%, at least 60% at least 70%, particularly preferably at least 80%. , more preferably at least 85%, more preferably at least 90% below the first blower power. By way of example only, the first blower output (electrical input power of the motor that drives the blower) may be 1,000 watts (W). The second blower output can be 900 watts (10% lower), or 700 watts (30% lower) or 500 watts (50% lower), 400 watts (60% lower), 300 watts (70% lower), 200 watts (80%). lower), 150 watts (85% lower), or 100 watts (90% lower). The difference between the first and second blower output is preferably selected depending on the nature of the first and second flooring categories. For example, the preferred difference in a long-pile tufted carpet as the first floor covering and a polished hard floor as the second floor covering may be substantially greater than, for example, a loop carpet or felt carpet as the first floor covering and a rough stone floor as the second floor covering. In a preferred embodiment of the invention, the first blower output is 1,000 watts, in another preferred embodiment 1,200 watts. In a preferred embodiment of the invention, the second blower output is 200 watts, in another preferred embodiment 300 watts, in another preferred embodiment 400 watts.

In a further preferred embodiment, the second air flow is at least 5%, particularly preferably 10% lower than the first air flow. However, the second air flow may also be more than 10% below the first air flow, for example at least 15%, at least 20%, at least 25%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70% lower the second airflow. Even lower values are also possible. By way of example only, the first air flow, for example, for a carpet as the first floor covering, 27 liters per second (l / s), the second air flow in a hard floor, 21 l / s. The second flow is thus approx. 25% lower than the first flow.

The air flow rates of the first and the second air flow are in particular also dependent on the blower, in particular its size, type and material, the performance characteristics of the engine and the power and voltage supply of the motor. This relationship is known to those skilled in the art by the performance characteristics of the blower, also referred to as the blower characteristic, which indicates the air flow rate as a function of the vacuum generated by the blower at a given blower output. Furthermore, the flow rates depend on the type of soil to be processed and the air flow in the vacuum cleaner, so for example, the type and geometry of the airways including the suction nozzle, the type of dust, the location and the type of eventually provided filter. This relationship is known to the skilled person by the load characteristic of the vacuum cleaner when working a particular floor covering that indicates the air flow as a function of the negative pressure generated by the fan at a given floor covering and a given air flow in the vacuum cleaner.

In particular, the type and configuration of the suction nozzle can significantly affect the load characteristic. In a preferred embodiment of the method according to the invention, the step of setting up the vacuum cleaner for processing a first or a second flooring category, that the suction nozzle of the vacuum cleaner for processing at least the first floor covering category and / or for processing the second flooring category is established, preferably that due to the signaled flooring category is set up for processing the first floor covering category or for processing the second floor covering category. In other words, the air duct of the suction nozzle, including the air duct can count in the border region between the suction nozzle and the floor covering is changed. In a particularly preferred embodiment of the invention, this setting takes place in that a first suction nozzle is used for a first floor covering category and a second suction nozzle is used for a second floor covering category. Alternatively, only one Suction nozzle can be used for both types of flooring, with the suction nozzle for the different flooring categories can be brought into different working positions. Thus, for example, the suction nozzle can be manually operated by means of an operating means in order to set it for one or the other floor covering category. By the operation, for example, a brush or a sealing lip on the suction nozzle or be extended. Typically, this one or more footswitches are provided on the nozzle. Additionally or alternatively, setting up the vacuum cleaner to handle a floor covering category may include other measures, such as changes in a vacuum cleaner of the vacuum cleaner or changes in the airway filters. In addition, a so-called electric nozzle can be provided as a suction nozzle, for example a suction nozzle with a brush roller driven by a motor. The brush roller can be used for operating on carpets, for example, to loosen dirt in the carpet and to transport this in the suction air stream. By using an electric nozzle, the dust can be improved with the same performance or the same dust consumption can be achieved with less energy. Preferably, the electric nozzle or its brush motor due to the signaled flooring category, ie depending on the determined flooring category, switched on or off to save additional energy, for example by switching off on hard floors, or to provide additional cleaning power available, for example by switching on carpets.

In a preferred embodiment of the method according to the invention, the flooring category is determined by means of a sensor. Preferably, a sensor signal, which signals the floor covering category, is transmitted directly or indirectly from the sensor to the control device, for example by means of a wired or wireless signal transmission. In one embodiment of the invention, the sensor signal may also be used to set up the vacuum cleaner to handle the floor covering category without requiring user operation, for example, to bring the suction nozzle into the required working position, eg motorized, or as described above when using an electric nozzle as a suction nozzle by connecting or disconnecting the electric nozzle.

In one embodiment of the invention, the user of the vacuum cleaner, the sensor signal is displayed, for example, optically by means of a light signal or a switch position. The user can set up the vacuum cleaner based on the signal displayed to process the flooring category, or check the vacuum cleaner setup.

The flooring category is detected in some embodiments of the invention by means of an electrical or optical or mechanical signal and transmitted to the control device or signaled. The signaling or signal transmission can be wired or wireless. Suitable methods for detecting the flooring category and suitable signal transmission methods are known to those skilled in the art.

In a further preferred embodiment of the method according to the invention, the floor covering category is determined by means of a pressure sensor, the pressure sensor preferably determining a pressure at a measuring position located upstream of a dust bag located in the vacuum cleaner during operation or a dust separation unit located upstream in the suction flow direction in the vacuum cleaner. Particularly preferably, a negative pressure value is measured or determined at the nozzle or suction nozzle of the vacuum cleaner, for example by means of a vacuum measuring cell. The nozzle can touch or rest directly on or on the floor covering. The pressure sensor may be disposed in the nozzle or in a special suction channel in the nozzle. The determined negative pressure value can be transmitted as an electrical signal to the control unit. The control unit can subsequently evaluate this signal, for example by adjusting or comparing the signal with a defined value stored in the control unit, and then selecting the floor covering if it exceeds or falls below it. This selection may result in automatic adjustment of the fan's electrical input (blower output). In further preferred embodiments of the method according to the invention, the pressure sensor can be arranged at different positions, for example directly on or in front of a dust bag or the dust separation unit or at another location between the nozzle and the fan in the suction channel, or in the nozzle.

In a preferred embodiment of the method according to the invention, the floor covering category is determined by means of an optical sensor or an infrared sensor or a radar sensor or an ultrasonic sensor or a mechanical sensor.

The flooring category can be determined in certain embodiments of the method according to the invention by means of an acceleration sensor or a vibration sensor. In particular, these types of sensors are attached or integrated on or in the suction nozzle.

In a preferred embodiment of the method according to the invention, the floorcovering category is determined by means of an exceeding or undershooting of a predetermined sensor signal threshold value. For example, sensor signal threshold values can be stored in the control device of the vacuum cleaner, for example as stored measured value curves or characteristics, or in another form. After a sensor measurement of a floor covering category, this sensor signal can be electronically compared with the stored sensor signal threshold values and automatic adjustment, in particular of the electrical input power of the blower, can take place. Sensor signal threshold values can advantageously be integrated simply and cost-effectively into various components of the vacuum cleaner, in particular into already existing components of the control device. The predetermined sensor signal threshold value can be selected such that it is exceeded when the first floor covering category is processed with the first blower output or the second blower output, and the first blower output or the second blower output is not reached when the second floor covering category is processed. This ensures that when changing flooring category, for example, because the suction nozzle is moved from a carpet to a hard floor, the flooring category can be reliably detected even if the currently processed flooring is processed with a blower that still the previously edited flooring category equivalent. Preferably, a digital pressure sensor, eg a so-called digital pressure cell or a digital pressure switch is also used to determine the floor covering category, ie a pressure sensor which detects the floor covering category based on exceeding or falling below a predetermined pressure threshold and then in the form of a YES / NO -Sensor signal signals, for example in the form of a voltage pulse or a logic level voltage (high level or low level).

In one embodiment of the invention, a change in the floor covering category is determined on the basis of the signaled floor covering category. Preferably, if such a change is detected, the controller may adjust the power consumption of the fan motor based on the signaled flooring category after a predetermined waiting time for the changed flooring category. The predetermined waiting time is at least 1 second, preferably at least 3 seconds, more preferably at least 5 seconds. By maintaining this waiting time (hysteresis), it is possible to compensate for pressure pulses in the determination of floor coverings. Hystereses can compensate for short-term pressure pulses. The waiting time ensures that any resulting fluctuations do not affect the control. In particular, this can compensate for a faulty control in the event of only a brief change in floor coverings or sensor signal peaks or misfires of one of the aforementioned sensors for determining the floor covering category. The maintenance of the waiting time can be communicated to the user, for example via an indicator on the vacuum cleaner. Further, the waiting time can be also provided for the aforementioned device of the suction nozzle of the vacuum cleaner depending on the floor covering category.

In one embodiment of the invention, the control of the power consumption of the fan motor due to the signaled flooring category, in particular due to a change in the floor covering category, continuously over a predetermined period of time. The predetermined period of time is at least 3 seconds, preferably at least 5 seconds. This ensures a smooth and quiet regulation. Furthermore, the predetermined period of time can follow the waiting time described above.

In one embodiment of the invention, the floor covering category can be determined on the basis of the device of the vacuum cleaner for processing the floor covering category. For example, can be determined by switches or contact areas on the suction pipe and / or on the suction nozzle, which suction nozzle is mounted on the suction pipe, or in which working position, the suction nozzle is located. Alternatively, an operating means is provided on which the user can specify the floor covering category, for example by the position of the operating means, on the basis of his subjective impression or on the basis of a displayed sensor signal. This information can then be signaled to the control device become. The indication can also be used for the device of the vacuum cleaner for processing the flooring category, for example, to bring the suction nozzle in the required working position, eg motor. In a preferred embodiment of the method according to the invention, the category of floor covering is determined by means of a mechanical switch. A mechanical switch may be a toggle switch, a pressure switch, or another mechanical switch. In one embodiment of the invention, the mechanical switch may be operated manually after the user makes a selection, for example, due to his subjective impression, such as between two categories of flooring, eg carpet and hard floor. The person's decision may also be made based on a displayed sensor signal that detects and displays the flooring category.

In a further embodiment of the method for operating a vacuum cleaner, the vacuum cleaner has a blower equipped with a blower motor, which generates an air flow through a suction nozzle of the vacuum cleaner. A controller controls the fan depending on a flooring category to be processed. In the method according to the invention, the vacuum cleaner is set up for processing at least one first floor covering category and a second floor covering category, the floor covering category is signaled to the control device, and the floor covering of the category for which the vacuum cleaner is set up is processed. The control device carries out a first control step, which consists in that the control device controls a power consumption of the fan motor on the basis of the signaled flooring category such that a first fan power is set for the processing of the first floor covering category, which is higher than a second fan power, which is responsible for the Processing of the second flooring category is set, wherein the first blower power and the second blower power are selected for operation of the vacuum cleaner with empty dust bag or empty Staubabscheideeinheit. The control device also carries out a second control step, which consists in that the control device controls a power consumption of the fan motor such that the first fan power set in the first control step during machining of the first floor covering category and / or the second fan power set during the first control step during machining the second flooring category depending on a Filling degree of a arranged in operation in the vacuum cleaner dust bag or a arranged in operation in the vacuum cleaner Staubabscheideeinheit is changed.

In a further preferred embodiment of the method according to the invention, the first blower output during the processing of the first floor covering category and / or the second blower output during the processing of the second floor covering category is dependent on a degree of filling of a dust bag arranged in the vacuum cleaner during operation or a dust separation unit arranged in operation in the vacuum cleaner changed. In particular, the blower outputs are increased with increasing degree of filling of the bag or the Staubabscheideeinheit, such as gradually or continuously. The degree of filling can be detected by means of different sensors, for example position sensors or force measuring sensors. The consideration of the degree of filling to the blower power adjustment can be referred to as a multi-stage control of the control device. Particularly preferably, the degree of filling is measured by a differential pressure sensor, or the first blower power is changed during the processing of the first floor covering category and / or the second blower power during the processing of the second floor covering category as a function of a measured differential pressure. The degree of filling can be determined from a pressure difference between a first pressure at a first measuring position upstream of the dust bag or the dust separation unit in the suction flow direction and a second pressure at a second measuring position downstream of the dust bag or the dust separation unit in the suction flow direction, the first and the second second pressure is determined by one or more, connected to the measuring positions pressure sensors. An advantage of the differential pressure measurement is that the degree of filling is determined independently of the processed flooring category can. Preferably, the differential pressure sensor measures a pressure drop across the dust bag or Staubabscheideeinheit. For this purpose, the differential pressure sensor is preferably connected via lines or hoses having two measuring points or measuring positions which are preferably in the suction flow direction respectively before and after the bag or the dust separation unit, preferably directly in front of and directly behind the dust bag or the dust separation unit. The differential pressure sensor may be an analog pressure sensor that outputs a sensor signal proportional to the measured pressure difference. Alternatively, the differential pressure sensor can be formed by two analog pressure sensors, wherein then the differential pressure from the pressure difference of two absolute pressures is determined, which are measured by the two analog pressure sensors at two points in Saugstromrichtung before and after the bag or the Staubabscheideeinheit. Further preferably, it is provided to arrange a first analog pressure sensor in Saugstromrichtung before the vacuum cleaner bag or Staubabscheideeinheit, and with this the floor covering category based on the measured negative pressure, eg as described above by comparison with a sensor signal threshold to determine. For pressure difference measurement, a second pressure sensor in Saugstromrichtung is arranged after the vacuum cleaner bag or the Staubabscheideeinheit, and carried out the pressure difference measurement by means of the sensor signals of the first and the second pressure sensor. This arrangement has the advantage that the sensor signal of the first pressure sensor is used both for the detection of the floor covering category, as well as for the determination of the pressure difference, and thus a separate detection of the floor covering category is avoided via a further sensor. Thereby, the inventive method can be simplified, and also simplifies the construction of the vacuum cleaner according to the invention and manufacturing costs can be saved. Alternatively, the degree of filling may be measured by determining the weight of the collected dust and debris and comparing it to a predetermined maximum fill weight. Preferably, a vacuum cleaner according to the invention has a display which indicates to the user when the bag or the Staubabscheideeinheit is full. Particularly preferably, the display indicates the degree of filling of the bag or the Staubabscheideeinheit.

In a preferred method, the fan power is changed depending on the degree of filling of the bag or the Staubabscheideeinheit so that the air flow over the duration of use of the bag or the Staubabscheideeinheit remains essentially constant. For this purpose, the fan power is preferably increased continuously or stepwise over the period of use. Particularly preferably, the air flow is kept substantially constant up to a degree of filling of at least 100%, 99%, 95%, 90%, 80%, 75% or 70%. A preferred vacuum cleaner for this purpose has a blower whose maximum power consumption is higher than the power consumption, which is adjusted when the bag or empty Staubabscheideeinheit, especially when operating with the first blower power in the processing of floor coverings of the first floor covering category. For example, this is a vacuum cleaner with a maximum power consumption of 1200 W, 1400 W or 1600 W, which is controlled for the processing of floor coverings of the first flooring category with empty bag or Staubabscheideeinheit to a first blower power of 1000 W. In an alternative embodiment of the method, the blower power is increased by a predetermined value each time the airflow rate falls below a predetermined threshold, preferably in increments of 1 W, 5 W, 10 W, 20 W, 30 W, 50 W, or 100, respectively W. With each increase of the blower power by one level, the air flow increases and then decreases again with further filling of the bag or the Staubabscheideeinheit from, until the limit falls below again and thus the blower output must be increased again.

Increasing the fan power with increasing degree of filling or increasing differential pressure is advantageous for the following reasons: As the degree of filling increases, the air resistance of the dust bag or the dust-collecting unit increases. With constant power consumption of the fan motor, this results in a successive decrease in the air flow through the suction nozzle. Since, according to the invention, a lower blower output is set in the processing of floor coverings of the second floor covering category, a decrease of the air flow to a value below a minimum air flow will generally be reached faster when machining floor coverings of the second floor covering category than at Processing of floor coverings of the first floor covering category. If a reduction in airflow below the minimum air flow rate is achieved more quickly when working floor coverings of the second floor covering category than when working with floor coverings of the first floor covering category, this may result in the minimum cleaning performance for the floor covering being second Flooring category is no longer available, although the dust bag or Staubabscheideeinheit is not yet completely filled, for example, only half filled. In contrast, by increasing the blower power with increasing filling level achieved that despite increasing air resistance of the bag or Staubabscheideeinheit an air flow that is greater than the minimum air flow, as long as possible and preferably over the entire useful life of the bag or Staubabscheideeinheit or until complete filling the bag or Staubabscheideeinheit can be provided. In other words, it is avoided that when processing a floor covering of the second floor covering category with the second, lower blower power and the second, lower air flow, a state is reached in which the air flow through the suction nozzle due to the increasing filling level of the bag or the Staubabscheideeinheit of the vacuum cleaner falls below the minimum air flow, although the bag or the Staubabscheideeinheit not completely filled, for example, only half filled.

Increasing the fan power in response to a differential pressure measurement, i. with increasing differential pressure over the bag or the Staubabscheideeinheit, has the advantage that thereby an air flow above the minimum air flow can be adjusted and thus optimal dust uptake over the period of use of the bag or the Staubabscheideeinheit can be provided without affecting the flow characteristics of the bag or the Staubabscheideeinheit would have to be known at different levels of filling and / or blower power. This is particularly advantageous if, instead of original bags of the vacuum cleaner manufacturer, those from third-party suppliers are used which, for example, can have a different dust retention capacity and / or a different filter resistance than the original bags.

Overall, it can thus be achieved by increasing the fan power with increasing filling level of the bag or Staubabscheideeinheit or increasing differential pressure that is saved by the control on the second, lower fan performance in the processing of floor coverings of the second flooring category energy without earlier in operation as necessary, a reduction in the dust absorption or the cleaning performance occurs, and without that incomplete filled dust bag or an incompletely filled Staubabscheideeinheit would have to be changed prematurely.

The above-described control of the power consumption of the blower motor due to the signalized flooring category and the above-described increase in the blower power with increasing degree of filling or increasing differential pressure can be understood as two-part control or control in two steps. In a first control step, as described above, based on the signalized flooring category, the blower output is controlled to a first blower output P1 or second blower output P2 provided for operation with an empty bag or empty dust separation unit. In a second control step, the power consumption of the blower motor is controlled so that the blower motor in addition to the first blower power P1 and second blower power P2 set in the first control step, an additional power, i. an auxiliary blower output, depending on the determined degree of filling of the bag or the Staubabscheideeinheit or differential pressure is provided. The total blower power controlled by both control steps or arrangements is then the sum of the respective first blower power P1 or second blower power P2 set in the first control step and the auxiliary blower power set in the second control step.

In the method according to the invention, floor coverings are assigned to the first floor covering category (K1) which, when processed with the suction nozzle, have a flow resistance which is greater than that which floor coverings have when processing with the suction nozzle, which are assigned to the second floor covering category. Preferably, the first flooring category carpet flooring and the second flooring category hard flooring are assigned. Furthermore, the carpet coverings and / or the hard floor coverings can be subdivided or subdivided. For example, carpet coverings may include the subcategories longhair rugs, felt rugs, sling rugs, etc. Similarly, carpet coverings can be divided into the categories of sensitive and less sensitive carpets, with a selection of these subdivisions, in particular by means of manual selection. For example, hard floor coverings can be used in the sub-categories smooth and rough coverings or subdivided into the subcategories hard floor with cracks and hard floor without cracks. In a preferred embodiment of the invention, the first Floor covering category A carpet as prescribed for standard measurement according to IEC 60312-1, Edition 1.1, valid since November 2011. In a preferred embodiment of the invention, the second flooring category is a hard floor with or without scratches, as it is also mandatory for the standard measurement according to IEC 60312-1, Edition 1.1, valid since November 2011. In another preferred embodiment of the invention, the second flooring category is specifically a hard floor with cracks, as prescribed for the standard measurement according to IEC 60312-1, Edition 1.1, valid since November 2011. In a further preferred embodiment of the invention, the second flooring category is specifically a hard floor without cracks, as prescribed for the standard measurement according to IEC 60312-1, Edition 1.1, valid since November 2011.

The noise emission can advantageously be reduced during vacuuming using the method according to the invention. For example, experience shows that the noise emission when vacuuming on hard floor coverings by a distance-dependent sound pressure level of about 10 dB (A), ie about 10 decibels in an upstream filter of category A (to simulate the human hearing), be higher than when vacuuming on carpet floor coverings. The measured distance-dependent sound pressure level refers to a person who uses the vacuum cleaner in a common application area. When using the method according to the invention, the higher sound pressure level of about 10 dB (A) on a hard floor covering as the second floor covering category can be advantageously reduced by means of the reduced second blower power.

The preferred blower motor is a universal electric motor. The preferred fan motor is a brushless electric motor. Preferably, the electric motor is commutated electronically. A preferred electric motor is a reluctance motor.

In a preferred embodiment of the method according to the invention, the blower power is controlled by means of a phase control. A phase control can be made by means of electronic components such as so-called Triacs (Triode for Alternating Current; Bidirectional thyristor triode).

In an advantageous embodiment of the invention, the vacuum cleaner is provided with a blower motor having a blower for generating an air flow through a suction nozzle of the vacuum cleaner. The vacuum cleaner according to the invention further comprises a recognition device for signaling a category of the floor covering to be processed from a category group comprising at least a first floor covering category and a second floor covering category to a control device for controlling the blower, the control device being functionally connected to the detection device, around the suction blower depending on a signaled flooring category. The control device may perform a first control in that the control device controls a power consumption of the blower motor based on the signaled flooring category such that a first blower power is set for the processing of the first floor covering category, which is higher than a second blower power, which for the Processing of the second flooring category is set, wherein the first blower power and the second blower power are selected for operation of the vacuum cleaner with empty dust bag or empty Staubabscheideeinheit. The control device can also carry out a second control, which consists in that the control device controls a power consumption of the fan motor such that the first fan power set in the first control contributes to the processing of the first floor covering category and / or the second fan power set in the first control the processing of the second floor covering category is changed as a function of a degree of filling of a dust bag arranged in the vacuum cleaner during operation or a dust separating unit arranged in operation in the vacuum cleaner.

With the present invention, despite increasing air resistance of the bag or the Staubabscheideeinheit with increasing degree of filling of the bag or Staubabscheideeinheit the fan power, especially when operating with the set in the first control step or in the first control second, lower fan performance can be adjusted so that a minimum air flow through the suction nozzle of the vacuum cleaner, which is necessary for a minimum cleaning performance of the vacuum cleaner, if possible over the entire useful life of the bag or Staubabscheideeinheit or possibly to complete bag filling or Staubabscheideeinheitbefüllung can be provided. In other words: It is avoided that when editing a floor covering of the second floor covering category with the second, lower blower power set in the first control step or in the first control, a state is reached in which the air flow through the tank is increased as a result of the increasing filling level of the bag or the dust separation unit Suction nozzle of the vacuum cleaner below the minimum air flow, although the bag or the Staubabscheideeinheit is not completely filled

In a preferred embodiment of the invention, the vacuum cleaner is provided with a suction strength selection means with which the user can select a suction strength. In one embodiment of the invention, only several, e.g. 2, 3, 4 or 5 discrete levels of suction strength are selected, in another embodiment of the invention, a suction strength can be selected from a continuous range of absorbency. The Saugstärkenauswahlmittel may be formed for example with a rotary switch with switching stages or with a continuous knob, with a slide switch, a slider, a lever or with key switches. Preferably, by selecting a suction level, the user may determine the first blower output for processing the first flooring category and the second blower power for processing the second flooring category.

The preferred suction nozzle is a bottom suction nozzle, i. it is suitable for use in vacuuming a floor. In a preferred embodiment, the suction nozzle has at least one (e), preferably two or more rollers or wheels or rollers or balls. This advantageously facilitates the movement of the suction nozzle on the soil to be processed. The preferred suction nozzle has a suction nozzle sole with which the suction nozzle rests on the surface to be processed, preferably on a base. In certain embodiments of the invention, the suction nozzle is configured with a coupling portion for connection to a suction channel, a hose or a suction pipe. Preferably, the suction nozzle is equipped with a coupling portion for coupling to a suction pipe of a vacuum cleaner. The connection may be a plug connection, for example with a bayonet closure. Such compounds can advantageously be easily solved, for example, to use different suction nozzles. Different suction nozzles can be designed for different floor coverings.

The processing of the floor covering of the respective category for which the vacuum cleaner is arranged is preferably carried out by means of manual or automatic machining. Manual machining may be manual forward, reverse, lateral, or a combination of these directions. Automatic machining can be a self-contained movement of the vacuum cleaner without direct manual intervention. In an automatic processing, the vacuum cleaner can be started manually, and the travels and the End position, for example, be controlled by sensors. In certain embodiments according to the invention, the second floor covering category is subsequently processed in time subsequent to the processing of the first floor covering category. However, the processing of the second floor covering category can also take place independently of time of the processing of the first floor covering category. As a result, the total intake capacity of the vacuum cleaner can be reduced without substantially impairing the dust absorption.

Brief description of the drawings

Further advantageous embodiments will be described in more detail below with reference to embodiments illustrated in the drawings, to which the invention is not limited.

The reference numbers in all claims have no limiting effect, but are only intended to improve their readability.

Fig. 1

Ein erfindungsgemäßer Staubsauger zum Durchführen des erfindungsgemäßen Verfahrens;

Fig. 2

ein Staubsaugerkennfeld mit idealisierten Funktionskurven für eine Saugdüse und zwei verschiedene Bodenbelagskategorien, aufgetragen über Saugdruckwerte und Luftdurchflusswerte;

Fig. 3

die Düsenkennlinie für die Saugdüse des Staubsaugers in der Arbeitsstellung "Teppichboden" auf einem Teppichboden, aufgetragen über Staubaufnahmen und Luftdurchflusswerte;

Fig. 4

die Düsenkennlinie für die Saugdüse des Staubsaugers in der Arbeitsstellung "Hartboden" auf einem Hartboden mit Ritzen, aufgetragen über Staubaufnahmen und Luftdurchflusswerte; und

Fig. 5

die zwischen den Arbeitsstellungen Teppich und Hartboden umschaltbare Saugdüse des Staubsaugers.

Fig. 6

ein Diagramm, das den Ablauf einer Steuerung der Leistungsaufnahme des Staubsaugers bei einer Änderung der Bodenbelagskategorie illustriert.

Fig. 7

ein Blockschaltbild einer Anordnung zum Regeln der Leistungsaufnahme des Staubsaugers mit einer Regelschaltung.

Fig. 8

ein Blockschaltbild eine alternativen Anordnung zum Regeln der Leistungsaufnahme des Staubsaugers mit einer Regelschaltung.

Fig. 9

ein Diagramm, das den Verlauf des Luftdurchflusses für zwei Bodenbelagskategorien in Abhängigkeit von der Staubbeutelfüllung illustriert.

They show schematically:

Fig. 1

An inventive vacuum cleaner for carrying out the method according to the invention;

Fig. 2

a vacuum cleaner map with idealized functional curves for a suction nozzle and two different flooring categories, plotted against suction pressures and air flow rates;

Fig. 3

the nozzle characteristic for the suction nozzle of the vacuum cleaner in the working position "carpet" on a carpet, applied via dust pick-up and air flow values;

Fig. 4

the nozzle characteristic for the suction nozzle of the vacuum cleaner in the working position "hard floor" on a hard floor with cracks, applied via dust pick-up and air flow values; and

Fig. 5

The switchable between the working positions carpet and hard floor suction nozzle of the vacuum cleaner.

Fig. 6

a diagram illustrating the process of control of the power consumption of the vacuum cleaner when a change in the floor covering category.

Fig. 7

a block diagram of an arrangement for regulating the power consumption of the vacuum cleaner with a control circuit.

Fig. 8

a block diagram of an alternative arrangement for regulating the power consumption of the vacuum cleaner with a control circuit.

Fig. 9

a diagram illustrating the flow of air flow for two types of flooring depending on the dust bag filling.

Detailed description based on embodiments

In the following description of preferred embodiments of the present invention, like reference characters designate like or similar components.

The in Fig. 1 Vacuum cleaner 1 shown consists of a subframe 2, the housing 3, an electric motor driven suction fan 4 with an electronically commutated electric motor as a blower motor (not shown) receives. The suction fan 4 is fluidly connected upstream with a separator 5, which receives a replaceable dust filter bag 6. In the dust filter bag 6 opens a recessed into the housing 3 suction line 7, which in turn interacts via a flexible suction hose 8 and a telescopic suction tube 9 with a switchable between the working positions "carpet" and "hard floor" with a foot switch suction nozzle 10. In another - not shown - embodiment is located in the separation device 5 instead of the dust bag 6, a Staubabscheideeinheit in the form of a Wirbelabscheiders, in which dust-laden suction air is cleaned by centrifugal forces. For cleaning of floor coverings is the Suction nozzle 10 placed on the surface to be cleaned and moved after switching on the suction fan 4 back and forth. The dust located on the ground is sucked together with ground-level air into the separator 5 and deposited in the dust filter bag 6, wherein in the flow channel between the suction nozzle 10 and the separator 5, a negative pressure is formed. The cleaned air flow is guided through the suction fan 4 and escapes through an exhaust port 11 in the housing 3 to the outside. The control device 12 controls the fan output of the fan motor as a function of the floor covering category set on the operating means 13 by means of a phase-intercepting control. At the operating means 13 can be selected between the categories "carpet" and "hard floor". In an alternative, not shown embodiment of the invention takes the place of the operating means of the aforementioned sensor types. The sensor compares a sensor signal with a predetermined sensor signal threshold and signals the controller 12 a carpet or hard floor, depending on whether the sensor signal is below or above the threshold.

In Fig. 2 a vacuum cleaner map 12 is shown for a suction nozzle 10 connected to the vacuum cleaner 1. The vacuum cleaner map shows idealized function curves for the carpet and hard floor carpet categories with joints. The function curves are plotted against a suction pressure p, measured in mbar (millibar), and over an air flow Q through the suction nozzle 10, measured in l / s (liters per second). The suction pressure p is the difference between the pressure outside the vacuum cleaner and the pressure at the location between the suction fan 4 and the separator 5. An exemplary fan characteristic P1 for a commercial with a universal motor operated at a power of 1000 W (suitable for the carpet category) as Blower motor idealized shown as a straight line. The blower characteristic P1 is represented by a suction region p between approximately 180 mbar with an air flow Q of 0 l / s up to a suction pressure of 0 mbar with an air flow Q of approximately 32 l / s. Furthermore, a second blower characteristic P2 of the same blower operated with a power of 300 W (suitable for flooring hard floor) also idealized shown as a straight line. The blower characteristic P2 is shown over a suction range p between about 110 mbar at an air flow Q of 0 l / s up to a suction pressure 0 mbar at an air flow Q of about 23 l / s. The blower characteristic depends on the blower, in particular its size, type and material, the Performance characteristics of the motor and the power and voltage supply of the motor dependent

For carpet and hard floor floor coverings, two idealized load curves K1 for carpet and K2 for hard floor with joints are also shown. These floor covering categories are selected according to the specifications for standard measurement according to IEC 60312-1. The load curves can be determined as arithmetic curves or as measured curves. Characteristic K1 indicates for the floor covering category carpet the possible operating points which are set at different blower outputs P. Analogously, the characteristic K2 for the floor covering category hard floor indicates the possible operating points which are set at different blower outputs P. The load curve depends on the type of floor to be worked (eg carpet or hard floor) and the air duct in the vacuum cleaner, for example the type and geometry of the air paths including the suction nozzle (eg carpet nozzle or hard floor nozzle), the type of Dust separation, the location and the type of possibly provided filter from.

Furthermore, the two operating points A and B of this embodiment are shown. For a blower output P1 of 1000 watts in the carpet category (K1), the operating point B results in a suction pressure p1 at the suction nozzle of approx. 40 mbar with an air flow Q1 of approx. 27 l / s. For the floor covering category hard floor (K2) signaled at the operating point A, according to the invention, the control device sets the lower blower power P2 at 300 watts. At operating point A, a suction pressure p2 at the suction nozzle of approx. 10 mbar with an air flow Q2 of approx. 21 l / s is established. This results in a difference in air flow of approx. 6 l / s, whereby the lower air flow Q2 at operating point A is set in the floor covering category hard floor.

Fig. 3 shows the nozzle characteristic of the suction nozzle in the "Carpet" position on a carpet selected in accordance with the specifications for standard measurement according to IEC 60312-1, Edition 1.1, valid since November 2011, above the dust absorption Y, measured in% (percent) and above Air flow Q, measured in l / s. The dust receptacle Y is in this embodiment for the floor category carpet K1 at the blower output P1 of 1000 W between approx. 65% at 0 l / s and approx. 85% at approx. 43 l / s.

Fig. 4 shows the nozzle characteristic of the suction nozzle in the hard bottom position on a hard floor with cracks corresponding to the specifications for standard measurement according to IEC 60312-1, edition 1.1, valid since November 2011, plotted against the dust pickup Y, measured in% (percent) and above Air flow Q, measured in l / s. The idealized characteristic shows a kink at an air flow of approx. 20 l / s. Above an air flow of approx. 20 l / s, the characteristic curve is flat, ie the dust absorption Y is constantly high between approx. 102% and 107%, up to an air flow of approx. 37 l / s. On the other hand, below an air flow rate of approx. 20 l / s, the dust pick-up Y drops sharply; with an air flow rate of approx. 17 l / s it is only approx. 70%.

The load characteristic depends not only on the floor covering but also considerably on the suction nozzle used and / or its working position. In Fig. 5 the switchable suction nozzle 10 is shown in the working position hard floor and positioned on a hard floor 20 with cracks 21. It has a suction nozzle upper shell 17, a section 18 with a circumferential sealing region 24 in the form of a rubber lip made of a thermoplastic elastomer (TPE) and a suction nozzle mouth 23. Due to the peripheral sealing region 20, it is possible to apply a high negative pressure in the suction region 25 and to achieve a high dust absorption, in particular also in the cracks 21. In particular, by means of the first portion 18 with the peripheral sealing region 24, an air inflow from the environment 26, and thus a possible lowering of the negative pressure in the suction region 25, can be largely prevented. By means of a foot switch, not shown, the portion 18 can be raised with the sealing area perpendicular to the bottom surface 16 so that the sealing area 24 loses its sealing effect. Now the suction nozzle 10 is in the working position carpet.

To carry out the method according to the invention, the user sets up the vacuum cleaner 1 first by means of the foot switch on the floor nozzle on the floor covering category to be processed (carpet or hard floor). Then he also sets this category on the operating means 13 or the category is detected by the sensor. The category is then the control means or sensor to the controller 12th Depending on the floor covering category, it adjusts the power consumption of the blower motor by means of phase-cut control either to P1 (in this example 1000 watts) in the case of the carpet category or to P2 (300 W in this example) in the case of the hard floor category. If a carpet or hard floor corresponding to the specifications for standard measurement in accordance with IEC 60312-1 is now machined, the in Fig. 2 at the operating points B and A shown on air flow. Both the blower output and the air flow in the case of the hard floor are lower than in the case of the carpet. As a result, the total intake capacity of the vacuum cleaner can be reduced without substantially impairing the dust absorption.

Fig. 6 shows a diagram illustrating the process of control of the power consumption of the vacuum cleaner when a change in the floor covering category. In the illustrated sequence, a change in the floor covering category is determined by a digital pressure sensor (also called a digital pressure switch) and the control device 12 is signaled. As explained below with reference to Fig. 8 However, instead of a digital pressure sensor, an analog pressure sensor can also be used, and, for example, the determination of the floor covering category can take place based on the sensor signal of the analog pressure sensor in the control device 12. In Fig. 6 The upper solid line P represents the blower power plotted against the operating time, and the lower solid line 60 represents a sensor signal of the digital switch. The switching states of the switch (LO for switch inactive, HI for switch active) and the blower outputs P1 and P2 are illustrated by horizontal dashed lines. In this example, the controller is initially designed so that, by default, the blower power P is set to the second, lower blower power P2 for the second flooring category K2 (hard floor in this example), and only after the signalized first flooring category K1 (carpet in this example) first, higher blower output P1 is set. At point 61, the power of the blower motor in this example is P2 = 400W. At point 61, the suction nozzle 10 of the vacuum cleaner 1 is on hard ground. The negative pressure at the pressure sensor at point 61 is in this example 30 mbar (with a power consumption of 400W). The threshold for triggering the digital pressure switch is 55 mbar in this example. At point 61, therefore, there is a pressure below the threshold, so that the digital pressure switch is inactive (LO), which in this example the floor covering category K2 (hard floor) is signaled. At point 62, the suction nozzle 10 changed to a carpet and the vacuum at the suction nozzle, for example, increases to 70 mbar (with a power consumption of 400 W). The pressure is thus greater than the threshold of 55mbar, and the pressure switch is active (HI), ie signals the floor covering category K1 (carpet). After a predetermined waiting time W of, for example, 3 seconds between points 62 and 63, the control device 12 regulates the power consumption of the fan motor from point 63 to point 64 to P1 within a predetermined period Z of, for example, 5 seconds, in this example from 400 W to P1 = 1000W. The suction nozzle 10 is still on carpet, the pressure at the suction nozzle 10 by increasing the power consumption of 400W to 1000W, for example, 140 mbar increases. At point 65, the suction nozzle 10 changes from carpet back to hard floor (at a power consumption of still 1000W) and it sets a pressure of, for example, 45 mbar, which is therefore below the threshold. Accordingly, the pressure switch is again inactive (LO), and thus signals the floor covering category K2 (hard floor). After the predetermined waiting time W between point 65 and point 66, at point 66, the controller downshifts the power consumption of the blower motor to point 67 within the predetermined period Z to P2 = 400W. Point 67 again corresponds to point 61. In this example, predetermined waiting times (hysteresis) are used to compensate for pressure fluctuations and / or pressure pulses. Also, to ensure smooth and quiet regulation, predetermined periods of time are used to vary the power consumption due to a change in flooring category.

In Fig. 7 is an arrangement for regulating the power consumption of the suction fan 4 of the Fig. 1 shown vacuum cleaner with a control circuit shown. The course of the suction flow or air flow generated by the suction fan 4 through the suction nozzle 10, the (optional) suction tube 9, the suction hose 8, the suction line 7 and the dust filter bag 6, in which the dust is separated, is indicated by the dotted arrows. After the suction flow has passed the dust filter bag 6, it exits the vacuum cleaner downstream of the suction fan at an exhaust port (not shown). An analog differential pressure sensor 33 measures the differential pressure from the pressures applied at the measuring points 31 and 32, which are respectively arranged in the suction flow direction directly before and after the dust filter bag 6. About the measured differential pressure, the degree of filling of the dust filter bag 6 can be determined. In alternative Embodiments of the invention, the degree of filling of the dust filter bag 6 but also by other methods, for example by weight measurement by means of a weighing sensor or by a position sensor can be measured. The control device 12 is designed to regulate the power of the suction fan 4 as a function of the determined degree of filling of the dust filter bag 6 or in dependence on the measured differential pressure. For this purpose, the differential pressure sensor 33 supplies an electrical signal corresponding to the differential pressure to the control device. If the dust filter bag fills, the flow resistance increases because, inter alia, the pores of the filter material gradually become clogged, or because the bag has a smaller effective cross section for the air flow due to the filling. In order to keep the air flow through the suction nozzle 10 substantially constant, the control device increases the power consumption of the suction fan, so that the increased flow resistance is compensated. The increase can be controlled on the basis of a predetermined proportionality constant, or on the basis of a pre-measured and stored in the control device power consumption differential pressure characteristic. Thus, advantageously, the cleaning effect of the vacuum cleaner can be kept substantially constant, preferably until the dust filter bag 6 is completely filled. In addition to the differential pressure sensor 33, the embodiment shown also has a digital pressure sensor 30 for determining the floor covering category K1, K2. When the negative pressure applied to the pressure sensor 30 exceeds or falls below a predetermined pressure threshold value, it sends a corresponding electrical switching signal to the control device 12. The control device 12 then sets the power consumption of the fan motor to P1 (for example, by means of phase-angle control) depending on the determined floor covering category K1, K2 1000 watts) in the case of the first floor covering category (for example carpet) or P2 (for example 400 W) in the case of the second floor covering category (for example hard floor). Alternatively, other sensors as described above, eg acoustic or optical sensors, can be used to determine the floor covering category K1, K2. The digital pressure sensor 30 for determining the floor covering category K1, K2 can expediently be arranged on the suction nozzle 10, in the suction pipe 9, in the suction hose 8 or also in the suction line 7.

In Fig. 8 is an alternative arrangement for regulating the power consumption of the suction fan 4 of the Fig. 1 shown vacuum cleaner with a control circuit shown. Unlike the in Fig. 7 shown arrangement uses in Fig. 8 shown arrangement instead of an analog differential pressure sensor 33 two analog pressure sensors 34 for absolute pressure measurement. As with the previously in Fig. 7 As shown here, the measuring points 31, 32 are arranged in the suction flow direction before and after the dust filter bag 6. The differential pressure can then be determined from the two measured in 31 and 32 negative pressures. The analog pressure sensor 34, which measures at the first measuring point 31, also takes over the task of the sensor 30 from the in FIG. 7 shown arrangement. By comparing the measured negative pressure with a predetermined reference value, the control device can determine the floor covering category K1, K2.

An inventive method for controlling the power consumption of the suction fan 4 one of the in the FIGS. 7 and 8 arrangements shown is based on the in FIG. 9 illustrated diagram illustrated. In the diagram, two curves are plotted, which represent the course of the air flow (in l / s) in dependence on the degree of filling of the dust filter bag 6 (in grams, g). The curve with the solid line 101 represents the course for the floor covering category K1 (carpet in this example), the curve with the dashed line 102 the course for the floor covering category K2 (hard floor in this example). Whether the vacuum cleaner is currently being used on a floor covering category K1 or K2, by means of the sensor 30 in the case of the arrangement according to Fig. 7 or in the case of the order according to Fig. 8 be determined by comparing the measured at the measuring point 31 with an analog pressure sensor 34 value with the predetermined reference value. With empty dust filter bag (0 g) at point 108, the power consumption of the suction fan in the case of carpet K1 in this example is 1000 W. At point 109, the power in the case of hard floor in this example is 400 W. The maximum power consumption of the suction fan 4 is in this Example 1400 W. During use of the vacuum cleaner, the dust filter bag 6 fills, so that the flow resistance and the measured differential pressure increase. In order to keep the air flow constant, the control device 12 regulates the power of the suction fan 4 to the measured filling level of the dust filter bag 6, ie increases the power.

If the sensor detects that the vacuum cleaner is being operated on carpet K1, the control device 12 regulates a power of 1000 W at point 108. Fills up now the Dust filter bag 6, the differential pressure increases continuously. The controller increases the fan power accordingly until at point 104 the maximum value of 1400 W is reached. The increase in the fan power can be done either continuously or stepwise. With carpet K1 the maximum performance is already reached with a dust bag filling of approx. 600 g, whereas with hard floor K2 this is only the case with approx. 800 g. Between points 104 and 106, the dust filter bag fills on. Since the suction fan is operated with maximum power starting at point 104, the air flow begins to decrease. At about 900 g, the dust filter bag 6 is completely filled (indicated by the vertical dashed line in the diagram) and settles quickly at the dust filter bag inlet with dust, so that now the air flow drops sharply and at 107 marked point below that for an effective cleaning effect at least required minimum air flow 103 of about 15 l / s falls. As soon as the measured air flow drops below the minimum air flow 103, an indication on the vacuum cleaner indicates to the user that the dust filter bag 6 is completely filled and needs to be replaced.

If the sensor detects that the vacuum cleaner is being operated on hard floor K2, the control device 12 regulates a power of 400 W at point 109. If now the dust filter bag 6 is filled, the differential pressure increases continuously. The controller increases the fan power accordingly, until at point 105, the maximum power of 1400 W is reached. Between point 105 and 106, the dust filter bag continues to fill, with the air flow decreasing as the power can not be further increased. As described above for carpet, the dust filter bag when reaching the vertical dashed line (level about 900 g) is completely filled, so that the flow resistance increases sharply and the air flow drops sharply until it at 107 marked point below the minimum air flow required for cleaning 103 falls, and the user of the now necessary bag change is displayed.

The air flow rates to which the air flow in carpet K1 or the air flow in hard floor K2 are controlled by appropriate control of the fan power in this example are 40 l / s and 25 l / s. With these values, a complete filling of the dust filter bag is possible and at the same time a sufficient cleaning performance is achieved, in particular cleaning class A on hard floor.

LIST OF REFERENCE NUMBERS

1

vacuum cleaner

2

assembly carrier

3

casing

4

aspirator

5

separating

6

Vacuum Cleaner Bags

7

suction

8th

suction

9

suction tube

10

suction nozzle

11

exhaust vent

12

control device

13

operating means

14

Vacuums map

15

another vacuum cleaner map

16

another vacuum cleaner map

17

Saugdüsenoberschale

18

section

19

sealing area

20

hard floor

21

scratch

23

Saugdüsenmund

24

sealing area

25

suction area

26

Surroundings

30

digital pressure sensor

31

first measuring point

32

second measuring point

33

Differential Pressure Sensor

34

analogue pressure sensor

60

Sensor signal A, B operating point

p, p1, p2

suction

HI

Pressure switch active

LO

Pressure switch inactive

Q, Q1, Q2

Air flow

Y

dust removal

P, P1, P2

fan power

K1

Flooring category carpet

K2

Flooring category hard floor

W

predetermined waiting time

Z

predetermined period of time

Claims (18)

1. Method for operating a vacuum cleaner (1), with a fan which has a fan motor and which generates an air flow (Q, Q1, Q2) through a suction nozzle (10) of the vacuum cleaner (1), and with a control device (12) which controls the fan as a function of a flooring category (K1, K2) to be processed, wherein

   - the vacuum cleaner (1) is designed to process at least a first flooring category (K1) and a second flooring category (K2),

   - the flooring category (K1, K2) is signalled to the control device (12), and

   - the flooring of the category (K1, K2), for which flooring the vacuum cleaner (1) is designed, is processed,

   characterised in that
   the control device (12) controls a power consumption of the fan motor based on the signalled flooring category (K1, K2), such that during the processing of the first flooring category (K1) both a first fan power (P1) and a first air flow (Q1) are higher than a second fan power (P2) and a second air flow (Q2) during the processing of the second flooring category (K2), and in that the first flooring category (K1) is assigned floorings which have a flow resistance during processing with the suction nozzle (10) which is greater than that which floorings which are assigned to the second flooring category (K2) have during processing with the suction nozzle (10), and/or carpet floorings are assigned to the first flooring category (K1) and hard floorings are assigned to the second flooring category (K2).
2. Method according to claim 1, characterised in that the second fan power (P2) is at least ten percent lower than the first fan power (P1).
3. Method according to claim 1 or 2, characterised in that the second air flow (Q2) is at least five percent lower than the first air flow (Q1).
4. Method according to one of the preceding claims, characterised in that the suction nozzle (10) of the vacuum cleaner (1) is, on the basis of the signalled flooring category (K1, K2), designed to process the first flooring category (K1) or to process the second flooring category (K2).
5. Method according to one of the preceding claims, characterised in that the flooring category (K1, K2) is determined by means of a sensor, preferably by means of an optical sensor, an infrared sensor, a radar sensor, an ultrasonic sensor, a mechanical sensor, an acceleration sensor or a vibration sensor, or by means of a mechanical switch.
6. Method according to claim 5, characterised in that the flooring category (K1, K2) is determined by means of a pressure sensor, wherein preferably the pressure sensor determines a pressure on a dust bag located in the vacuum cleaner (1) during operation or a dust separation unit located in the vacuum cleaner (1) during operation at a measurement position upstream in the suction flow direction.
7. Method according to claim 5 or 6, characterised in that the flooring category (K1, K2) is determined by whether a predetermined sensor signal threshold is exceeded or undershot.
8. Method according to claim 7, characterised in that the predetermined sensor signal threshold value is selected such that it is exceeded when processing the first flooring category (K1) with the first fan power (P1) or the second fan power (P2), and is undershot when processing the second flooring category (K2) with the first fan power (P1) or the second fan power (P2).
9. Method according to one of the preceding claims, characterised in that a change in the flooring category (K1, K2) is determined on the basis of the signalled flooring category (K1, K2), and if a change has been determined the control device (12) controls the power consumption (P1, P2) of the fan motor based on the signalled flooring category (K1, K2) after a predetermined waiting time (W).
10. Method according to one of the preceding claims, characterised in that the control of the power consumption (P1, P2) of the fan motor is performed continuously over a predetermined period of time (Z) based on the signalled flooring category (K1, K2).
11. Method according to one of the preceding claims, characterised in that the first fan power (P1) during the processing of the first flooring category (K1) and/or the second fan power (P2) during the processing of the second flooring category (K2) is changed as a function of a fill level of a dust bag arranged in the vacuum cleaner (1) during operation or of a dust separation unit located in the vacuum cleaner (1) during operation.
12. Method according to claim 1, wherein the first fan power (P1) and the second fan power (P2) are selected for operation of the vacuum cleaner (1) with an empty dust bag or an empty dust separation unit, and the control device (12) performs a second control step, which consists in that the control device (12) controls a power consumption of the fan motor such that the first fan power (P1) set in the preceding control step is changed during the processing of the first flooring category (K1) and/or the second fan power (P2) set in the preceding control step is changed during the processing of the second flooring category (K2) as a function of a fill level of a dust bag arranged in the vacuum cleaner (1) during operation or of a dust separation unit arranged in the vacuum cleaner (1) during operation.
13. Method according to claim 11 or 12, characterised in that the fill level is determined from a pressure difference between a first pressure at a first measurement position upstream of the dust bag or the dust separation unit in the suction flow direction and a second pressure at a second measurement position downstream of the dust bag or the dust separation unit in the suction flow direction, wherein the first and the second pressure is determined by one or more pressure sensors connected to the measurement positions.
14. Method according to claim 13, characterised in that the first pressure is used to determine the flooring category (K1, K2).
15. Method according to one of the preceding claims, characterised in that carpet floorings are assigned to the first flooring category (K1) and hard floors are assigned to the second flooring category (K2).
16. Vacuum cleaner (1) with a fan having a fan motor for generating an air flow (Q, Q1, Q2) through a suction nozzle (10) of the vacuum cleaner (1), a detection device for signalling a category of the flooring to be processed from a category group (K1, K2), which comprises at least a first flooring category (K1) and a second flooring category (K2), to a control device (12) for controlling the fan, wherein the control device (12) is functionally connected to the detection device in order to control the suction fan (4) as a function of a signalled flooring category (K1, K2),
    characterised in that
    the control device (12) can control a power consumption (P1, P2) of the fan motor based on the signalled flooring category (K1, K2), such that during the processing of the first flooring category (K1) both the first fan power (P1) and a first air flow (Q1) are higher than during the processing of the second flooring category (K2) with a second fan power (P2) and a second air flow (Q2), and in that the first flooring category (K1) is assigned floorings which have a flow resistance during processing with the suction nozzle (10) which is greater than that which floorings which are assigned to the second flooring category (K2) have during processing with the suction nozzle (10), and/or carpet floorings are assigned to the first flooring category (K1) and hard floorings are assigned to the second flooring category (K2).
17. Vacuum cleaner (1) according to claim 16, wherein the first fan power (P1) and the second fan power (P2) are selected for operation of the vacuum cleaner (1) with an empty dust bag or an empty dust separation unit, and the control device (12) can perform a second control, which consists in that the control device (12) controls a power consumption of the fan motor such that the first fan power (P1) set in the preceding control is changed during the processing of the first flooring category (K1) and/or the second fan power (P2) set in the preceding control is changed during the processing of the second flooring category (K2) as a function of a fill level of a dust bag arranged in the vacuum cleaner (1) during operation or of a dust separation unit arranged in the vacuum cleaner (1) during operation.
18. Vacuum cleaner (1) according to claim 16 or 17, for performing the method according to at least one of claims 1 to 15.

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