EP2548491A1 - Vacuum cleaner and method for operating same - Google Patents

Abstract

The vacuum cleaner (1) has a drive unit e.g. suction fan (2) that generates a volume flow rate and a negative pressure. A volume flow rate determination unit determines volume flow rate value generated during operation, and a pressure sensor determines negative pressure value generated during operation. A drive unit controller (15) compares determined volume flow rate value and negative pressure value with a preset threshold as a design limit. An inverter (16) reduces electrical power input supplied to drive unit based on comparison result. Independent claims are included for the following: (1) method for operating vacuum cleaner; and (2) program for operating vacuum cleaner.

Description

The invention relates to a vacuum cleaner and a method for operating a vacuum cleaner. Vacuum cleaners are known per se and are operated with electric power either from a mains network or from an entrained voltage source, namely an accumulator or the like.

Vacuum cleaners remove a comparatively high electrical power from the respective voltage source and convert it into an air or suction power at a floor nozzle or a suction pipe. The suction power results as a product of negative pressure on the one hand and volume flow or flow on the other. During the suction process results with attached floor nozzle a preferred work area with good efficiency, ie a good ratio of absorbed electrical power and emitted suction, about half of the maximum possible flow rate. Often, however, during suction, the floor nozzle or the suction tube end is removed from the floor and set aside to remove e.g. Moving furniture, moving the vacuum cleaner or even going to another room, picking up a phone call, or just to stop sucking. During this time usually the vacuum cleaner is not switched off by the user, but continues with maximum flow, but without suction, on. From an energetic point of view is particularly unfavorable that in this situation, the maximum power is taken from the power source, but no suction power at the floor nozzle is available and is not needed. In addition, there is the fact that the usual noise of a vacuum cleaner continues throughout the period of non-use.

• Aus der WO 02/091899 A ist ein Verfahren zur Erkennung einer Situation, in welcher der Staubsauger nicht benutzt wird, auf Basis von Druckmesswerten bekannt. Dazu werden in einer in Folge aufgenommenen Mehrzahl von Druckmesswerten ein minimaler und ein maximaler Druckmesswert ermittelt und daraus die Differenz gebildet. Wenn diese Differenz unterhalb eines Schwellwertes liegt (also innerhalb der Zeit, während derer die Druckmesswerte aufgenommen wurden, nur geringe Schwankungen der Druckmesswerte sensiert werden), wird angenommen, dass der Nutzer den Staubsauger derzeit nicht verwendet, so dass die Motorleistung des Saugebläses reduziert wird.

In order to avoid an unnecessarily high energy consumption by the suction fan and further to avoid the associated with the operation of the suction fan noise during the period of non-use or to detect a non-use situation different proposals have become known:

• From the WO 02/091899 A For example, a method for detecting a situation in which the vacuum cleaner is not used is known based on pressure readings. For this purpose, a minimum and a maximum pressure measurement value are determined in a plurality of pressure measurement values recorded in sequence, and the difference is formed therefrom. If this difference is below a threshold value (ie within the time during which the pressure readings were taken, only slight fluctuations in the pressure readings sensation), it is assumed that the user is currently not using the vacuum cleaner, so that the engine power of the suction fan is reduced.

A consideration of a fluctuation of pressure measurements is also the approach of US 6,105,202 underlying in which it is proposed to avoid an undesirably high noise and an unnecessarily high energy consumption in an activated, but not in-use vacuum cleaner by means of exactly one pressure sensor and given rules for processing pressure readings in that the speed of the suction fan is reduced, if the pressure readings do not change or change only slightly, ie if a first time derivative of a sequence of pressure readings remains below a threshold value.

The JP 2 243 125 A wants to recognize the situation of use by means of movements of the floor nozzle and proposes to detect the movement of the floor nozzle by means of a motion sensor acting as a sensor that detects a rotation of a wheel of the floor nozzle. If a standstill of the floor nozzle is sensed in this way for more than a predetermined period of time, this should be usable for switching off the suction fan.

The US 2010/0 281 646 A describes an operating method for a specific type of vacuum cleaner, namely a so-called upright vacuum cleaner, in which the use situation is to be detected by means of a tilt sensor, so that the suction fan is supplied to a greater extent electrical power when the device is tilted, because of a continued use is closed and the power supply is reduced when the device is in an upright position.

From the DE 10 2007 025 389 A An operating method for a vacuum cleaner is known which aims at a uniform noise development. It is provided that by means of a control device, the volume flow generated by the suction fan is influenced as a control variable. However, a measurement of the volume flow generated in each case is not required and the volume flow is therefore not known. Instead, empirical values can be used, according to which the volume flow is dependent on the respective floor covering and, for example, is higher on smooth floors than on carpet floors. On this basis, it is sufficient if the control device information is transmitted to the respective floor covering, so that instead of a volume flow sensor not required here, a floor covering sensor can occur.

From the DE 689 16 607 T An operating method for a vacuum cleaner is known in which exactly one pressure sensor detects the static pressure generated by the suction fan. When increasing the detected static pressure, the suction blower output is increased to increase the volume flow. The increase in suction fan power is canceled again when the detected static pressure falls below a threshold. The DE 689 16 607 T In order to avoid vibrations, it proposes that the threshold value at which the increase in the suction blower power is reduced is below the threshold value at which the increase in the suction blower power was previously caused.

An object of the invention is to provide a vacuum cleaner and a method for operating a vacuum cleaner, in which a non-use situation is reliably detected, and so unnecessarily high energy consumption by the drive unit of the suction fan and further associated with the operation of the suction fan noise during the period the non-use is avoided.

This object is achieved with the features of claim 1.

For this purpose, in a vacuum cleaner with a drive unit and a drive unit control, wherein the drive unit generates a volume flow and a negative pressure in operation of the vacuum cleaner due to supplied electrical power, provided first that the vacuum cleaner means for detecting a measure of the volume flow generated during operation and means for Detecting a measure of the negative pressure generated during operation includes. Without waiving any further generality, the phrase "to capture a measure" is sometimes omitted in the following for the sake of better readability in determining a measure of a particular size. It will be understood by those skilled in the art that equivalent solutions will result if a particular size is not immediately detectable, but a measure of the particular size is detectable and, instead, that measure is used for the particular size. A measure of a volume flow generated during operation or a measure of a negative pressure generated during operation is, for example, a respective proportional or inversely proportional electrical current or voltage. In general, detection of a measure for a particular quantity is the acquisition of a respective measured value and the generation and / or transmission of a relevant signal.

In this sense, this formulation is sometimes omitted below for other sizes considered and defined in claim 1 vacuum cleaner is characterized further characterized in that the drive unit control means for forming a calculated value from the detected volume flow and the detected negative pressure, optional means for comparison the detected volumetric flow with a predetermined or predefinable volumetric flow upper limit, but in any case comprises means for comparing the arithmetic variable with a predetermined or predeterminable threshold value as a design limit. By comparing the volumetric flow with the volumetric flow upper limit, a situation can be recognized in which the floor nozzle is removed from the floor, because in this situation the Volume flow increases significantly. The floor nozzle removed from the floor is a distinguishing feature for a non-use situation, because, for example, even with a stored suction pipe, the floor nozzle is completely or partially lifted from the ground. By comparing the calculated size with the design limit, a raised state of the floor nozzle can be reliably detected. In a parallel consideration of volume flow and computational size also a false evaluation is avoided, which is possible, for example, when the increased volume flow results through a new, empty suction bag. For example, a ratio of the volume flow to the negative pressure, in particular a quotient of the volume flow and the negative pressure, as well as a respective signal or a quotient of the square of the volume flow and the negative pressure (each ratio of the volume flow to the negative pressure, In particular, each quotient formed from the volume flow and negative pressure, so to speak, is a measure of the suction power, because the suction power as a product of the volume flow and the negative pressure results), so that the computational size basically only meaningful in terms of increased flow and a causal lifting the floor nozzle from the ground is. For example, the arithmetic quantity formed, for example, in the form of a quotient or other ratio of volumetric flow and reduced pressure increases sharply when the maximum volumetric flow for the respective filling level of the anther / dust collecting container of the vacuum cleaner is reached. In principle, any qualified calculation algorithm which calculates a measure of the volume flow q and a measure of the negative pressure h as input variables comes into consideration for forming the arithmetic variable. Especially good experiences were made with an algorithm based on q * q / h for thresholding.

Finally, the drive unit control also comprises means for reducing the electrical power consumption of the drive unit as a function of both the result of the comparison of the volume flow with the volume flow upper limit and the result of the comparison of the calculated value with the design limit. Alternatively, it can be provided that the drive unit control does not itself comprise the means for reducing the electrical power consumption of the drive unit, but controls it.

In the EP 0373 353 A is driven with the exhaust air flow of a suction fan, an air turbine and detects their speed. The air turbine acts as a volumetric flow sensor and with a measured value supplied by it, a determination of operating conditions of the vacuum cleaner, for example, the Staubbeutelfüllgrads be possible. The EP 0373 353 A also mentions the possibility of combining the volumetric flow measured values supplied by the air turbine with measured values of a diaphragm pressure switch in order to be able to recognize operating states which can not be unambiguously identified solely on the basis of a volumetric flow measured value.

The EP 0373 353 A But there is no indication of the determination of a suction and there is no linked comparison of flow on the one hand and suction power on the other hand, each with associated comparison values. Furthermore, should at the EP 0373 353 A no reduction in the power consumption of the drive unit done, but it is rather an operating state display can be controlled to indicate, for example, to a level of the dust bag.

The advantage of the invention is that with the detection of a measure of the volume flow and the detection of a measure of the negative pressure, a direct determination of the relevant parameters for determining the suction power, so that an indirect suction power measurement or at least an indirect determination of a measure of the Suction power, which is attributed to a direct measurement of the relevant parameters. On the basis of the calculation variable in each case determined measure of the suction performance, the use situation can be easily and reliably detected, especially a non-use situation can be easily detected, because in a non-use situation, the suction decreases immediately drastically and finally disappears. The advantage of the invention is further that with the thus ensured improved detection of the non-use situation, an automatic stop function for the vacuum cleaner is realized - by further embodiments, even an automatic start-stop function -which reduces the power consumption when the electric Performance is actually not needed. Accordingly, the approach proposed here is also referred to below as the start-stop function. Furthermore, the reduction in power consumption of the drive unit without renouncing the broader general validity is also referred to below as "switching off" the drive unit, even if this shutdown may not be a complete, but only a partial reduction in power consumption means. Such a shutdown of the vacuum cleaner always means a termination or at least a reduction of the usual noise of the vacuum cleaner.

Advantageous embodiments of the invention are the subject of the dependent claims. Here used backlinks indicate the further development of the subject matter 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 obtaining independent, objective protection of 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.

In one embodiment of the vacuum cleaner it is provided that the drive unit control means for detecting a duration of exceeding the upper limit of the volume flow through the detected volume flow and means for comparing the duration of the excess with a predetermined or predetermined time limit and as a means for reducing the electrical power consumption depending on Result of comparison of detected duration and time limit activatable signal output includes. In this way it is achieved that the stop function is actually activated only when the condition for its activation is fulfilled for a certain period of time, so that e.g. not every brief lifting of the floor nozzle and the concomitant short-term increase in the volume flow leads to an undesired shutdown of the drive unit. Sensible values for the time limit are according to the knowledge of the inventor in the order of magnitude of 50 ms to 200 ms.

In this embodiment, therefore, the detected volumetric flow is compared with the volumetric flow upper limit, and when the volumetric flow upper limit is exceeded by a duration predetermined by the time limit, activation of the signal output of the drive aggregate control is possible. Actually, however, the signal output is only activated if, in addition, the value of the calculated variable formed on the basis of the measured values for negative pressure and volumetric flow exceeds the rated limit. Alternatively, it is also possible to provide only the arithmetic variable, that is, for example, the quotient of volumetric flow and negative pressure, and the design limit for the activation of the stop function, possibly taking into account a time limit value. Regardless of the specific embodiment, the design limit allows consideration of the resistances of the dust bag and the engine and exhaust filters on the one hand and the current power setting for the drive unit on the other.

In a further embodiment, the vacuum cleaner has a linking functionality, for example an AND gate or the like, as a means for combining the result of the comparison of the detected duration and time limit on the one hand and the result of the comparison of the calculated value and the design limit on the other hand, an output of this Linking functionality represents the activatable signal output. The activatable signal output can then be switched to an actuator to reduce the power consumption of the drive unit and thus cause the "shutdown" of the drive unit in the sense explained above.

By an effected reduction of the power consumption of the drive unit is detected as the state of the vacuum cleaner and during such a state with a decrease in the volume flow and / or an increase in the negative pressure, the reduction of the electric Power consumption of the drive unit is withdrawn, can be the "shutdown" of the drive unit cancel when the operating situation changes, so if, for example, the lifted floor nozzle is replaced and the user continues the suction process. For the user, this results in a fully automatic start-stop function, namely on the one hand an automatic "shutdown" (stop function) and on the other hand, an automatic restart of the drive unit (start function). The detection of a decrease in the volume flow or an increase in the negative pressure or a decrease in the volume flow and a simultaneous increase in the negative pressure are expressly independent and at least substantially equivalent criteria for the automatic restart of the drive unit. If only or even the negative pressure is considered, is particularly considered to add sensed pressure changes and deriving from the exceeding of a threshold by the sum thus formed a signal to reactivate the drive unit.

By at rest, ie in connection with the withdrawal of the reduction of the electrical power consumption of the drive unit, the drive unit is at least briefly applied with a respective maximum allowable motor voltage, the performance setting corresponding operating situation of the vacuum cleaner before automatic deactivation can be achieved faster again.

If a duration of the short-term loading of the drive unit with the respective maximum permissible motor voltage depends on a pre-selected for the drive unit power position, there is a dynamic restart of the drive unit depending on the operating situation to be achieved before the automatic deactivation.

If a duration of this state is detected in the state of a reduced reduction of the power consumption of the drive unit and the drive unit is deactivated at a duration exceeding a predetermined or specifiable threshold value, the automatic stop function or the automatic start-stop function is meaningfully supplemented in that initially and quasi as a stop function of the first degree, the power consumption is reduced, but not yet reduced to zero, and that the reduction of power consumption to zero, so the actual shutdown of the drive unit, only occurs if within a certain time no activation of the drive unit through Further use of the vacuum cleaner takes place (stop function of the second degree). When the drive unit is switched off, it can be provided that this can only be activated again via a user action, for example the actuation of a pushbutton or the like, or a movement of the floor nozzle that can be detected via a movement sensor. This allows the complete shutdown not only of the drive unit, but also the Control electronics and thus a reduction of the energy consumption of the vacuum cleaner to zero or almost zero. Sensible values for the threshold are, according to the inventor's knowledge, of the order of magnitude of about thirty seconds.

The above object is also achieved with a vacuum cleaner which operates according to the method as described here and below and comprises means for carrying out the method. The invention is preferably implemented at least partially in software or in software and firmware / hardware. The invention is on the one hand also a computer program with executable by a computer program code instructions and on the other hand, a storage medium with such a computer program and finally a control unit in the form of a drive unit control or with such a drive unit control or a vacuum cleaner with such a control unit, in the memory as a means for Implementation of the method and its embodiments such a computer program is loaded or loadable.

The advantage of the invention and its embodiments is thus in particular as follows: While the vacuum cleaner is operated in a situation in which, for example, the floor nozzle is lifted off the carpet or floor covering and no cleaning effect occurs or other, short suction breaks are inserted, the recorded electrical Power can be lowered in the short term and dynamically reconnected without the user having to accept a suction power restriction or carry out additional activities. Especially in operation with a floor nozzle removed from the carpet (open panel), the maximum power is taken from the electrical network (P1 = max), although then no suction power can be applied (negative pressure generation by the drive unit is then hardly possible; towards zero and thus also the suction power P2 approaches zero). These conditions have been accepted so far. In the context of higher energy costs and ecological rethinking, an intelligent control is useful, with which the electrical power consumption can be drastically reduced and automatically raised again depending on the usage situation without restricting the user or impairing the suction result. In addition, with the approach proposed here not only the electrical power consumption can be minimized in the periods in which is not sucked in the predefined working area, but also minimizes or at least reduced with the operation of a vacuum noise associated, so that also a cheaper acoustic effect results. The noises are due to the lack of noise insulation of the floor nozzle on the floor and - much more - by the maximum flow and the resulting maximum air velocity. For the power reduction (automatic stop function) has a period of 50 ms to 200 ms and for startup (automatic start function), a period between 20 ms and 100 ms proved to be advantageous in terms of dynamics.

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, within the scope of the present disclosure, numerous modifications and variations are possible, for example, by combination or modification of the individual elements or method steps described in the general description, or each embodiment and the claims, and included in the drawings for the expert with regard to solving the problem can be removed and lead by combinable features to a new object or to new process steps or process steps.

Figur 1

einen Staubsauger an sich bekannter Art in einer Ausführungsform als Bodenstaubsauger,

Figur 2

eine Antriebsaggregatsteuerung als Mittel zur Implementation des hier beschriebenen Ansatzes,

Figur 3

und

Figur 4

schematisch vereinfachte Flussdiagramme eines durch die Antriebsaggregatsteuerung ausführbaren Steuerungsprogramms als Mittel zur Implementation des hier beschriebenen Ansatzes,

Figur 5

die Antriebsaggregatsteuerung gemäß Figur 2 mit weiteren, optionalen Details,

Figur 6

und

Figur 7

besondere Ausführungsformen des Steuerungsprogramms in Form von Flussdiagrammen auf Basis der in Figur 3 und Figur 4 gezeigten Situation.

Show it

FIG. 1

a vacuum cleaner of a known type in one embodiment as a vacuum cleaner,

FIG. 2

a power plant controller as a means of implementing the approach described herein;

FIG. 3

and

FIG. 4

schematically simplified flowcharts of a control program executable by the power plant controller as a means of implementing the approach described herein,

FIG. 5

the drive unit control according to FIG. 2 with further, optional details,

FIG. 6

and

FIG. 7

particular embodiments of the control program in the form of flowcharts based on in FIG. 3 and FIG. 4 shown situation.

FIG. 1 schematically shows a simplified vacuum cleaner 1 in one embodiment as a vacuum cleaner. However, the invention is basically suitable for any vacuum cleaner 1, which is equipped with a blower unit with a motor-driven suction fan 2 as a drive unit. The vacuum cleaner 1 shown has a housing 3 which is divided into a fan chamber 4 and a dust collecting space 5. In the fan chamber 4, the suction fan 2 is directed with its suction side to the dust collection chamber 5 and generates there a negative pressure, which is passed through a connected suction hose 6 and a suction pipe 7 to the suction mouth of a floor nozzle 8. Thus, air laden with dirt 9 - represented by the arrows 10 - is absorbed on the processed substrate (suction air stream) and cleaned by means of a dust separator. In the embodiment is this is a dust bag 11 with downstream engine filter 12. The cleaned air is discharged through an exhaust filter unit 13 back to the environment. The control of a fan motor 14 of the suction fan 2 is carried out in a conventional manner via control electronics of a control unit 15 for controlling, for example power semiconductors of an inverter 16. The control unit 15 is an example of a drive unit control or the control unit 15 includes such a drive unit control. The fan motor 14 of the suction fan 2 is fed during operation of the vacuum cleaner 1 in a conventional manner with electrical power. The suction fan 2 thus generates a negative pressure and finally a volume flow as the basis for the suction air flow. For operation and for user information, an operating and display device 17 is provided.

As a means for detecting a measure of a volume flow generated during operation (formula sign q), in particular analogous values for the actual volume flow q, various solutions come into consideration: For example, a particular analog differential pressure sensor in the immediate vicinity of the suction fan 2, for example in the range of there usually provided motor protection grille. The measured differential pressure between static / dynamic pressure decrease (Pitot probe) correlates very well with the volume flow q in the measuring range under consideration. Alternatively, e.g. a Hitz wire, a pressure connection to the suction fan 2 or the derivation of the volume flow q from the engine characteristics thinkable and feasible. The central suspension of the suction fan or a rubber seal of the suction fan is particularly suitable as a location for the measurement of the volume flow, because there prevail the largest flow velocities. Here is also considered to inject appropriate sensors in the central suspension / rubber seal, for example.

As a means for detecting a measure of a vacuum generated during operation (formula sign h) comes for the vacuum cleaner 1, a pressure sensor, as a differential pressure sensor against ambient pressure in the region of the inlet opening of the vacuum cleaner 1 into consideration, the pressure in the suction hose 6 or to capture at the entrance of the dust bag 11. The negative pressure measured there can still be compensated by the volume flow-dependent pressure drop in the suction hose 6 in order to guarantee a constant suction power at the end of the suction hose 6. In the case of a local pressure measurement in the floor nozzle 8, this would indeed be dispensed with, but it would require additional wiring effort to the floor nozzle 8.

For processing a measure of the volume flow, that is, for example, a volumetric flow rate 20, the in FIG. 2 Drive unit controller 21 shown as a functional unit of the control unit 15, a comparator 22 as a means for comparison the volumetric flow measured value 20 with a predetermined or predeterminable and, for example, stored in a memory 23 volumetric flow upper limit. Depending on the result of the comparison made with the comparator 22, the inverter 16 is actuated via an activatable signal output 24 as a means for reducing the electrical power consumption of the suction fan 2 (drive unit) as an actuator for the drive unit by generating a related control signal.

For alternative or additional processing of a measure of the negative pressure, that is, for example, a negative pressure measured value 25, the in FIG. 2 Drive unit controller 21 shown as a functional unit of the control unit 15, a comparator according to the above-mentioned comparator 22 as a means for comparing the negative pressure measured value 25 with a predetermined or predetermined and for example stored in a memory 23 vacuum lower limit. Depending on the result of the comparison made with the comparator, the inverter 16 is actuated via an activatable signal output 24 as means for reducing the electrical power consumption of the suction fan 2 (drive unit) as an actuator for the drive unit by generating a related control signal.

The implementation of the invention and its embodiments is particularly considered in software or firmware, so that, for example, the comparator 22 as a software or firmware functionality in a control program 30 (FIG. FIG. 3 ) is implemented in the memory 23 of the power plant controller 21. The further explanation is continued without abandoning the broader general validity based on the assumption of a software implementation, although in principle a hardware implementation or a combined implementation in software and hardware is conceivable.

FIG. 3 shows a flowchart for re-explanation of the principles of the approach according to the invention. Thereafter, as part of the execution of the control program 30 by a processing unit (not shown) in the form of or in the manner of a microprocessor, ASICs or the like by means of the drive unit controller 21, first a measure of a volume flow generated by the vacuum cleaner 1 in operation and / or a measure of the volume flow generated by the vacuum cleaner 1 during operation, on the one hand, and a measure of a vacuum generated by the vacuum cleaner 1 during operation, on the other hand, and a calculated variable from the volume flow and negative pressure as a measure of a suction power (first function block 31). Then, in a second functional block 32, the detected volume flow with a predefined or predefinable volumetric flow upper limit and / or the arithmetic variable with the prespecified or specifiable as a design limit Threshold compared. Depending on the result of the comparison, in particular depending on the result of both comparisons, the electrical power consumption of the drive unit is then possibly reduced by appropriate control of the inverter 16 (third function block 33). Thereafter, unless an abort is caused by its execution, the control program is cyclically continued by re-execution of the first function block 31.

FIG. 4 shows the course of the calculated size with a first, left curve for a full or at least partially filled dust bag and in a right curve for an empty dust bag. The curves are plotted on the abscissa above a respective volumetric flow and on the ordinate over a ratio of volumetric flow and negative pressure. It can be seen that both curves - that is, regardless of the degree of filling of the dust bag - rise sharply for increasing volumetric flow readings. In this respect, the design limit can be drawn as a horizontal line (in FIG. 4 dashed line) and the same numerical value of the design limit can be used for situations with empty, partially filled to full dust bag.

FIG. 5 shows on the basis of the flowchart in FIG FIG. 3 a particular embodiment of the control program 30, in which it is checked with an intermediate fourth function block 34, whether the detected volume flow exceeds the upper flow limit longer than a predefined or predefinable time limit duration, and the reduction of power consumption by execution of the third function block 33 only at Reaching or exceeding the time limit takes place.

The principles of the approach according to the invention mentioned in the general part of the description can be implemented with a correspondingly extended control program 30 on the basis of in FIG. 3 and FIG. 5 shown principle with suitable function blocks and implement their implementation in software.

On the basis of the measure of the volume flow detected on the one hand and the detected measure of the negative pressure on the other hand, an arithmetic variable is formed within the first functional block 31, for example a ratio between volumetric flow and negative pressure. This variable can be compared, analogously as described above, with a threshold value predetermined or predeterminable as the rated limit, for example within the second functional block 32. Depending on the result of the comparison, a reduction of the power consumption of the drive assembly can then take place. This can be done by driving the inverter 16 directly ( FIG. 3, FIG. 5 Function block 33) or by a result of the fourth through the function block 34 (checking the duration of exceeding the upper flow limit) with the comparison of Calculation variable with the design limit, for example, by a logical AND operation is combined and correspondingly the third function block 33 is only executed when both conditions are met.

In addition shows FIG. 6 an embodiment of the drive unit controller 21 based on the already in FIG. 2 shown situation. Here, in addition to the volumetric flow measured value 20, a negative pressure measured value 25 is processed in the form of a variable formed from the volumetric flow measured value 20 and the negative pressure measured value 25 (ratio of the volumetric flow measured value 20 to the negative pressure measured value 25), for example in the form of a quotient of the volumetric flow measured value 20 and the negative pressure measured value 25. The calculated size can be formed in basically any form. In the foreground is a sufficient steepness in variations of the volume flow measurement 20 (see FIG. 4 ). The respective numerical value of the arithmetic variable can therefore be the result of a mathematical relation, for example as a quotient of the volumetric flow measured value 20 and the negative pressure measured value 25 or as a quotient of the square or higher powers of the volumetric flow measured value 20 and the negative pressure measured value 25, eg q ^ n / h ^ n , q ^ n / h, etc., or an algorithm and the like. To form the arithmetic variable, in particular the quotient, a corresponding functional unit 26 is provided. The arithmetic variable is then compared by a comparator 27 with a predetermined or predetermined threshold value, which is stored, for example in the memory 23 and retrievable there. The output signals of the two comparators 22, 27 are logically linked in a suitable manner by a logic unit 28, for example an AND gate, and as a result of this combination, a signal is generated via the activatable signal output 24, depending on the type of connection and input signals for the logic unit 28 generated to drive the inverter 16.

The activatable signal output 24 can thus be activated both as a function of the result of the comparison of the detected duration and time limit value (comparator 22, linking unit 28) and also depending on the result of the comparison of the calculated value with the design limit (functional unit 26, comparator 27, linking unit 28). If - as proposed here - it is provided that both conditions realized by the comparators 22, 27 have to be fulfilled for the reduction of the electrical power consumption of the drive unit, the linking unit 28 is an AND gate or a functionally equivalent unit. If a fulfillment of only one of the conditions is to be sufficient, the linking unit 28 is a corresponding OR gate. If only the arithmetic variable and the design limit are to be used for activating the activatable signal output 24, optionally the branch with the comparator 22 and the combining unit 28 can be dispensed with and the output of the comparator 27 can be applied directly to the activatable signal output 24. The However, consideration of both conditions has the advantage that the calculation of the computation size must be made only if a potential non-use situation is recognizable on the basis of a volumetric flow upper limit exceeding a limit, so that in normal operation monitoring of the volumetric flow with respect to the volumetric flow upper limit is sufficient and only on reaching or exceeding the volumetric flow upper limit, the formation of the arithmetic variable takes place, and thus resources are not unnecessarily used in the sense of computing power and / or storage space.

FIG. 7 shows a further embodiment of the control program 30. In this case, an effected reduction of the power consumption of the drive unit is detected as the state of the vacuum cleaner 1 by in the cyclic execution of the control program 30 and as long as the conditions expressed by the second and fourth function blocks 32, 34, are always met is branched to the third functional block 33 and thus the control of the inverter 16 is maintained to reduce the power consumption. Other ways of detecting such a condition, such as by setting a corresponding flag in the control program 30 and interrogating it elsewhere, are also conceivable. Here, after the third functional block 33 has been processed, that is to say during the state of reduced power consumption, a possible decrease in the volume flow and / or an increase in the negative pressure is checked by a fifth function block 35 and, depending on the result of this check, if necessary a sixth function block 36 is called up. with the reduction of the electrical power consumption of the drive unit is withdrawn.

It can be provided in a particular embodiment (not shown) that in connection with the withdrawal of the reduction of the electrical power consumption of the drive unit, the drive unit is at least briefly acted upon by a respective maximum allowable motor voltage. Furthermore, it can be provided that a duration of the brief application of the drive unit with the respective maximum permissible motor voltage depends on a preselected power position for the drive unit. For example, in memory 23 (FIG. FIG. 2 . FIG. 6 ), a so-called look-up table (LUT) which for each possible power position or a plurality of power value value ranges each includes a time value. This is read out of the memory 23 / the LUT upon activation of the drive unit and used for monitoring the duration of the drive of the drive unit.

FIG. 8 Finally, FIG. 3 shows a flowchart for an embodiment of the method or a subsequent drive unit control based on the illustration in FIG FIG. 7 , By a seventh function block 37 is checked whether the state of reduction of electrical power consumption already longer than a by a predetermined or predetermined threshold value, which is stored for example in the memory 23, expressed time period exists. If this is the case, the drive unit is deactivated and branched to an eighth function block 38, which causes the deactivation of the drive unit. A ninth functional block 39 can connect to the eighth functional block 38, with which, for example, a user action, for example a movement of the floor nozzle or the actuation of a push-button of the operating and display device 17, is monitored. If such a user action is detected, a branch is made to the sixth function block 36 and the drive unit is reactivated. If no such monitoring of a user action provided, there is always a way to re-activate an automatically completely disabled drive unit to turn off the vacuum cleaner 1 on the power switch and turn it back on or turn-depending on the type of automatic deactivation, causing the control program 30th is started with newly initialized starting values with regard to the recorded measured values 20, 25 or the monitored times and the drive unit initially runs as usual until the floor nozzle or the suction pipe is removed from the ground and the stop mechanism or start-stop system described here is started. Automatic to avoid unnecessary energy consumption in the activation state of the drive unit engages.

Basically, a possible by the user or the manufacturer of the vacuum cleaner or customer service calibration of the automatic stop or start-stop automatic is conceivable. For this purpose, a calibrating mode intended for calibration would be activated on the vacuum cleaner, for example by actuating a corresponding switching element or by actuating an already existing switching element for more than a predetermined duration. The power plant controller indicates the beginning of the calibration by means of a signal emitted by the vacuum cleaner, for example a flashing display device. Then the floor nozzle is lifted and kept in the off position for, for example, at least two seconds. After a predetermined period of time, for example two seconds, the drive unit control detects the volumetric flow measured value 20 and the negative pressure measured value 25. The two measured values recorded are temporarily stored. Upon completion of the acquisition of these readings, the vacuum will signal the beginning of a second part of the calibration. On such a signal, the floor nozzle is placed and kept for example at least two seconds in the mounted state. After a predetermined period of time, for example two seconds, the drive unit control again detects the volumetric flow measured value 20 and the negative pressure measured value 25. These two measured values are also temporarily stored. From the two cached measured values for the volumetric flow, a new value for the volumetric flow upper limit can be directly derived, for example as the mean value between the two measured values. The new upper flow limit will be in memory, for example a non-volatile memory, the drive unit control stored. In the same or similar way, values for a rated limit can be formed in each case with the values stored temporarily in pairs for the volume flow and negative pressure, and the new rated limit then also results, for example, as the mean value between the two previously formed values. The new rated limit is also stored in the memory, for example a non-volatile memory, of the drive unit control. There, the new volume flow upper limit and / or the new rated limit are available as device-specific calibrated or updated limit values. Such a calibration helps to identify aging influences and resulting changes in the vacuum and volume flow that can be reached during operation and to adjust the switching conditions for activating the stop or start-stop system. Furthermore, with such a calibration, it is also possible to adapt the switching conditions to different bottom nozzles.

Individual foreground aspects of the approach described here can thus be briefly summarized as follows: There are a vacuum cleaner 1 with a drive unit and a drive unit controller 21 and a method for operating such a vacuum cleaner 1, said the drive unit in the operation of the vacuum cleaner 1 due to supplied electrical power generates a volume flow and a negative pressure, wherein vacuum cleaner 1 and drive unit control 21 are characterized in that the vacuum cleaner 1 comprises means for detecting a measure of the volume flow generated during operation and a measure of the negative pressure generated during operation and the drive unit controller 21 means 22nd for comparing the detected volumetric flow and a predetermined or predefinable volumetric flow upper limit and / or means 27 for comparing a calculated variable formed from the detected volumetric flow and the detected negative pressure with a designation limit or predeterminable threshold, and means 16, 24 for reducing the electrical power consumption depending on the result of the comparison or both comparisons includes or controls. Alternatively or additionally, a corresponding monitoring can also take place with respect to a negative pressure generated during operation and a lower negative pressure limit. Thus, an automatic stop function is realized, in further embodiments even an automatic start-stop function. The functionality that implements the automatic switch-off and possibly the restarting of the drive unit can be embodied as permanently active functionality or as user-activatable functionality. In the case of a basically permanently active functionality, it can be provided that the functionality can be deactivated by the user.

LIST OF REFERENCE NUMBERS

1

vacuum cleaner

2

aspirator

3

casing

4

blower room

5

Dust collection chamber

6

suction

7

suction tube

8th

floor nozzle

9

dirt

10

Arrow (to show dirty air)

11

anther

12

motor filter

13

Exhaust air filter unit

14

blower motor

15

control unit

16

inverter

17

Operating and display device

20

Flow measurement

21

Drive unit control

22

comparator

23

Storage

24

signal output

25

Under pressure reading

26

functional unit

27

comparator

28

linking unit

30

control program

31-39

(first, second, ... ninth) function block

Claims (15)

Vacuum cleaner (1) with a drive unit and a drive unit control (21), wherein the drive unit generates a volume flow and a negative pressure during operation of the vacuum cleaner (1) due to supplied electrical power,
the vacuum cleaner (1)
Means for detecting a measure of the volume flow generated during operation and means for detecting a measure of the negative pressure generated during operation, characterized
in that the drive unit control (21)
Means for forming an arithmetic variable from the measure of the detected volume flow and the measure of the detected negative pressure and
Comprises means (27) for comparing the arithmetic variable with a threshold value predetermined or specifiable as a design limit and
in that the drive unit control (21)
Means (16, 24) for reducing the electrical power consumption of the drive unit depending on the result of the comparison of the calculated size with the rated limit includes or controls. Vacuum cleaner (1) according to claim 1, wherein the drive unit control (21) means (22) for comparing the measure of the detected volume flow with a predetermined or predetermined volumetric flow upper limit and means (16, 24) for reducing the electrical power consumption of the drive unit in dependence on both Result of the comparison of the volume flow with the volume flow upper limit as well as on the result of the comparison of the calculated variable with the rated limit includes or controls. Vacuum cleaner (1) according to claim 2, wherein the drive unit control (21) comprises means for detecting a duration of exceeding of the upper flow limit by the detected volume flow and means for comparing the duration of the excess with a predetermined or predetermined time limit and as a means for reducing the electrical power consumption depending on the result of the comparison of the detected duration and time limit activatable signal output (24). Vacuum cleaner (1) according to claim 3, comprising a linking unit (28) as a means for combining the result of the comparison of the detected duration and time limit on the one hand and the result of the comparison of the calculated value and the design limit on the other hand, wherein an output of the linking unit (28) the activatable Signal output (24) represents. Method for operating a vacuum cleaner (1) according to one of claims 1 to 4, wherein in operation a measure of the volume flow generated by the drive unit and a measure of the negative pressure generated by the drive unit is detected,
wherein the drive unit control (21) from the volume flow and the negative pressure forms an arithmetic variable, the arithmetic variable with the rated limit compares and depending on the result of the comparison, the electrical power consumption of the drive unit is reduced. Method according to claim 5,
wherein the drive unit controller (21) compares the detected volume flow with the predetermined or predefinable upper volume flow limit and generates a first control signal as a function of the result of the comparison,
wherein the drive unit controller (21) generates a second control signal as a function of the result of the comparison of the calculated variable and the rated limit, and
wherein the first control signal and the second control signal are linked and wherein the electric power consumption of the drive unit is reduced depending on the result of the combination. The method of claim 6, wherein the drive unit controller (21) detects a duration of exceeding the upper limit of the volume flow through the detected volume flow and compares the duration of the excess with a predetermined or predetermined time limit and generates the first control signal depending on the result of the comparison of the detected duration and time limit , Method according to one of claims 5, 6 or 7, wherein an effected reduction of the power consumption of the drive unit is detected as the state of the vacuum cleaner (1) and wherein during such a state with a decrease in the volume flow and / or an increase in the negative pressure, the reduction of the electric Power consumption of the drive unit is withdrawn. The method of claim 8, wherein in connection with the withdrawal of the reduction of the electrical power consumption of the drive unit, the drive unit is acted upon at least for a short time with a respective maximum allowable motor voltage. The method of claim 9, wherein a duration of the short-term loading of the drive unit with the respective maximum permissible motor voltage depends on a pre-selected for the drive unit power position. Method according to one of claims 8 to 10, wherein in the state of a reduced power reduction of the drive unit, a duration of the state is detected and wherein at a predetermined or predefinable threshold exceeding duration, the drive unit is deactivated. The method of claim 11, wherein a deactivated drive unit can only be activated again via a user action. Vacuum cleaner (1) according to one of claims 1 to 4 with means for carrying out the method according to one of claims 8 to 12. A computer program comprising computer executable program code instructions for implementing the method of any of claims 5 to 12 when the computer program is executed by a microprocessor. Vacuum cleaner (1) according to Claim 13, comprising a drive unit control (21) comprising a memory (23) and a microprocessor as means for carrying out the method according to one of Claims 5 to 12 and a control program which can be executed by the microprocessor and loaded into the memory (23) (30) as a computer program according to claim 13.

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