CN114532907A

CN114532907A - Attachment for a cleaning device, suction wiper and method for wet cleaning a surface

Info

Publication number: CN114532907A
Application number: CN202111403774.5A
Authority: CN
Inventors: 迪特马尔·格哈特; 西尔维娅·哈西亚
Original assignee: Bohong University Of Applied Technology; Vorwerk and Co Interholding GmbH
Current assignee: Bohong University Of Applied Technology; Vorwerk and Co Interholding GmbH
Priority date: 2020-11-24
Filing date: 2021-11-24
Publication date: 2022-05-27
Also published as: DE102020131028B4; DE102020131028A1

Abstract

In order to improve the wet cleaning by means of a cleaning device, in particular to improve the determination of the moisture content of the cleaning elements for wet cleaning while using little circuit engineering effort, the invention proposes an attachment (2) for a cleaning device (60), a suction wiper and a method for wet cleaning a surface (58). The attachment (2) has a housing (4), a carrier element (6) for accommodating a cleaning element (8) provided for wet cleaning, and two sensor electrodes (16, 18) arranged on the carrier element (6), wherein the sensor electrodes (16, 18) are designed to generate an electrical signal that is dependent on the moisture content in the cleaning element (8), wherein a drive device (30) is provided for moving the carrier element (6) relative to the housing (4), wherein the sensor electrodes (16, 18) are capacitively coupled to two receiving electrodes (24, 26) arranged on the housing (4), and wherein a sensor (42) is provided for determining the position of the carrier element (6) relative to the housing (4).

Description

Attachment for a cleaning device, suction wiper and method for wet cleaning a surface

Technical Field

The invention relates to an attachment for a cleaning appliance, having a housing, a carrier element for accommodating a cleaning element for wet cleaning, and two sensor electrodes arranged on the carrier element, wherein the sensor electrodes are designed to generate an electrical signal that is dependent on the moisture content in the cleaning element, wherein a drive device is provided for moving the carrier element relative to the housing. The invention also relates to a suction wiper and a method for wet cleaning a surface.

Background

Attachments of the type mentioned at the outset are commonly used for wet cleaning floors. Typically, the housing of the accessory has a connection means for connecting with the cleaning device. This may be an autonomous, self-propelled cleaning device or a manually guided cleaning device. The cleaning apparatus may be constructed to be used as a vacuum cleaner in addition to wet cleaning. In this way, a combined suction wiper can be used for vacuuming and wet cleaning of floors.

For wet cleaning, the cleaning elements, such as ultra-fine fiber cloths or mops, are typically wetted periodically to ensure adequate cleaning performance throughout the wet cleaning process. A liquid source, for example a water tank, is usually provided on the cleaning device for wetting. It is common to automatically deliver a quantity of liquid from a liquid source to the cleaning elements at regular intervals. During wet cleaning, the cleaning elements lose liquid, depending on the nature of the floor to be cleaned and the force with which the cleaning elements are pressed against the floor to be cleaned, especially when the cleaning device is manually guided. Consequently, subsequent wetting at regular intervals can easily result in the cleaning element being too wet or too dry, so that proper cleaning performance cannot be guaranteed throughout the cleaning process. For sensitive floor coverings, such as parquet floors, excessively wet cleaning elements can damage the floor covering. In cleaning devices that do not have a liquid source and cannot automatically wet the cleaning element, the cleaning element is typically wetted manually, for example by dipping the cleaning element into a liquid-filled container, such as a bucket. Even when wetting the cleaning element manually, it is difficult to select the correct point in time for the subsequent wetting of the cleaning element and to ensure that the humidity in the cleaning element is constant.

In order to ensure constant humidity in the cleaning member, it is therefore necessary to detect the humidity at uniform intervals. It is known from the prior art to detect moisture by means of a sensor and to wet the cleaning element as a function of the detected moisture.

The robotic suction wiper disclosed in EP 2762051 a2 uses a capacitive sensor to detect the moisture content of the cleaning element. The capacitive sensor is integrated in the housing of the robot wiper.

From DE 102018128687 an accessory is known, which has a housing with a receiving area for receiving a cleaning element, with a capacitive sensor for detecting the moisture content of the cleaning element attached to a base plate that moves relative to the housing. The capacitive sensor is arranged in the receiving area of the base body and is connected to the electronics of the accessory by means of a radio or communication connection.

The sensitivity of the sensor is very important for reliably detecting the moisture content of the cleaning element. The sensitivity of a capacitive sensor is generally dependent on the mounting location of the sensor. In addition to optimum humidity, the cleaning process can be improved by moving the cleaning element relative to the attachment. However, the movement of the cleaning element relative to the attachment makes the mounting and operation of the sensor and associated electronics more difficult. If the sensor is mounted directly on the cleaning element, the cable-guided connection of the sensor is complicated by the relative movement of the cleaning element with respect to the attachment and in some cases is even impossible. The radio-technical solutions for signal transmission and energy supply are technically complex and increase in cost. If the sensor is mounted on the attachment itself, but at a distance from the cleaning element, for example by means of an additional material arranged between the sensor and the cleaning element, the sensitivity of the sensor is reduced. Typically, the distance between the sensor and the cleaning element is determined by the thickness of the base plate to which the cleaning element is attached and the air gap between the base plate and the attachment.

Disclosure of Invention

The invention is therefore based on the technical problem of improving the wet cleaning by means of a cleaning device, in particular of improving the determination of the moisture content of the cleaning elements for wet cleaning, while using little circuit engineering effort.

According to a first teaching, this object is achieved according to the invention by the accessory mentioned at the outset in that the sensor electrodes are capacitively coupled to two receiving electrodes arranged on the housing and a sensor for determining the position of the carrier element relative to the housing is provided.

It is recognized within the scope of the invention that the use of a capacitive coupling of the sensor electrode with two receiving electrodes arranged on the housing enables a determination of the wetness of the cleaning element in a technically simple manner.

By providing a sensor for determining the position of the carrier element relative to the housing, the influence of the relative position of the carrier element relative to the housing on the capacitive coupling is taken into account, wherein the position is determined in particular in a time-dependent manner. The position of the carrier element relative to the housing has a great influence on the capacitive coupling of the sensor electrodes on the carrier element with the receiving electrodes on the housing, since the capacitance of the capacitor is usually dependent on the relative arrangement of the capacitor plates. Thus, the sensor for determining the position of the carrier element can improve the determination of the wetness of the cleaning element. Accordingly, the subsequent wetting of the cleaning elements can be made more reliable and thus in a more targeted manner, and the wet cleaning can be designed more efficiently.

In addition, wireless connection of the sensor can be achieved through the capacitive coupling design of the sensor and the accessory electronic device, thereby reducing the complexity of circuit technology.

In general, the moisture of the cleaning element used in the wet cleaning process can be determined more reliably by the attachment according to the invention, thereby increasing the effectiveness of the cleaning process.

Within the scope of the invention, two sensor electrodes arranged on the carrier element and designed to generate an electrical signal as a function of the moisture content in the cleaning element form the two electrodes of the capacitive sensor and form a capacitor. In general, the capacitance of a capacitor is determined by the electric field between two electrodes of the capacitor, in the present case the sensor electrodes of a capacitive sensor. The functional principle of a capacitive sensor is based on the fact that the capacitance changes when the electric field between two sensor electrodes changes. The electric field may depend on various factors, for example on the properties of the insulating material, dielectric, between the sensor electrodes. For example, if a volume of air is used as the dielectric between the sensor electrodes, changes in air humidity can result in changes in the capacitance of the capacitive sensor. This change in capacitance can be measured in a number of ways. For example, if the capacitive sensor forms part of a resonant circuit, a change in capacitance may cause a change in the resonant frequency of the resonant circuit.

The two sensor electrodes arranged on the carrier element are preferably in one plane and the moisture content of the cleaning cloth influences at least a part of the electric field between the sensor electrodes. The change in the moisture content of the cleaning cloth causes a change in the capacitance of the capacitive sensor, thus generating an electrical signal according to the moisture content in the cleaning element. By capacitive coupling of the sensor electrodes with receiving electrodes arranged on the housing, signals can be transmitted in a technically simple manner to the electronics of the housing, where they can be analyzed further. The capacitive coupling between the receiving electrode and the sensor electrode is in a similar way based on the principle of capacitors.

The sensor electrodes are preferably arranged for applying a high-frequency alternating voltage of a certain predetermined frequency and generating a signal having a frequency dependent on the capacitance value of the capacitive sensor. The frequency generated by the sensor electrodes and thus the sensitivity of the capacitive sensor depend not only on the moisture content of the immediate environment of the sensor electrodes, in particular of the part of the cleaning element protruding into the electric field between the sensor electrodes, but also on the material and thickness of the cleaning element. For example, the sensitivity may depend on the type of fabric of the cleaning element, e.g., whether it is a fine-meshed or coarse-meshed cleaning cloth. The sensor electrode shape and the relative arrangement of the sensor electrodes to each other may also have an effect on the sensitivity of the capacitive sensor.

Within the scope of the present invention, moisture content is understood to mean in particular the content of liquid or vapor. For example, the moisture content may be the content of water or water vapor. Furthermore, water mixtures, in particular mixtures of water and cleaning agents, and other chemical solutions or waxes suitable for floor cleaning can also be used as liquids.

Elements made of natural or artificial fabrics, cloths, sponges or foams can be used as cleaning elements, wherein the cleaning elements are preferably suitable for cleaning and/or caring for surfaces and are capable of absorbing moisture.

The capacitive coupling between the sensor electrode according to the invention and the receiving electrode of the housing of the accessory enables a wireless operation of the capacitive sensor on the moving part of the accessory. No radio technology is required to transmit the signal from the sensor electrode to the electronics arranged on the accessory housing. The material costs of the accessory design according to the invention can thus be significantly reduced compared to the material costs of wireless solutions with electronic circuit technology for radio-based signal and energy transmission.

The carrier element can be moved relative to the housing by providing a drive means for moving the carrier element. In this way, the surface to be cleaned, for example a floor, can be cleaned more effectively when a wet wiping is performed. The liquid, in particular cleaning liquid, which is transferred onto the floor by the cleaning element is distributed evenly over the floor by the movement of the carrier element. By means of the sensor arranged on the housing, the position of the carrying element relative to the housing can be determined, in particular as a function of time, and the movement of the carrying element relative to the housing can thus be tracked. This makes it possible to take into account the influence of the movement of the carrier element on the capacitive coupling and thus on the determination of the moisture content.

The sensor for determining the position of the carrier element relative to the housing is preferably designed as a hall sensor. Furthermore, the sensor may be based on other methods for position determination, for example the sensor may be designed as an optical sensor, an ultrasonic sensor or an infrared sensor.

Furthermore, the simple and robust design of the attachment design according to the invention is advantageous in terms of the forces acting on the carrier element during the acceleration movement. Simple and strong structures are generally not prone to wear during use. In particular, the capacitive coupling of the sensor electrodes and the resulting cable-based connection of the sensor to the electronics of the accessory are dispensed with, so that a simple construction is possible.

The drive device can also cause a rotational movement of the brush roller if the carrying element is designed as a cylindrical roller. The movement of the carrying element relative to the housing may be determined in dependence on the angle of rotation of the roller.

By determining the position of the carrier element relative to the housing, in particular as a function of time, it is also possible to detect a change in the speed of the carrier element relative to the housing. If the relative speed of the carrier element changes while the drive power of the drive means remains constant, this may indicate an increased static friction between the floor and the carrier element.

The stopping of the load bearing element can also be detected, for example, if the movement of the load bearing element is blocked by an obstacle on the floor. If a stop is detected, further measures can be initiated, for example the drive can be stopped. For example, overheating of the drive device can be avoided when the movement of the carrier element is prevented, whereby safety risks can be minimized.

It can be provided for the attachment that the carrier element with the cleaning element is at least temporarily fixedly arranged or can be locked relative to the housing of the attachment. In this way, the cleaning process can be performed without operating the drive device, and power-saving operation of the accessory can be achieved.

According to a second teaching, the above object is achieved according to the invention by a suction wiper for wet cleaning of a surface having a vacuum cleaner and an attachment as described at the beginning, wherein the attachment is designed for connection to the vacuum cleaner.

By using a suction wiper with a vacuum cleaner and the attachment described at the outset, the floor can be cleaned more effectively, since both a vacuum cleaning of the floor and a wet cleaning of the floor can be effected using the suction wiper. The capacitive coupling of the capacitive sensor to the housing of the accessory improves the mobility of the movable part of the accessory as a whole, since complex radio technology or mobility-limiting cabling can be dispensed with. Thus, not only the wet cleaning process itself but also the dust suction process using the suction wiper according to the present invention can be improved due to the increased mobility.

Furthermore, the capacitive coupling of the capacitive sensor with the housing allows for a more flexible design of the carrier element, since no components need to be provided for connecting the capacitive sensor with the housing.

The provision of a sensor for determining the position of the carrier element relative to the housing of the attachment also allows the position of the carrier element relative to the vacuum cleaner of the suction wiper to be determined at least indirectly. Thus, even when cleaning using the suction wiper according to the invention, the movement of the carrying element relative to the housing of the attachment and relative to the cleaner can be taken into account and cleaning can be carried out more efficiently.

In the case of a suction wiper, it can be provided that the attachment with the carrier element with the cleaning element, which is at least temporarily fixed or lockable relative to the housing, is moved relative to the vacuum cleaner. Thus, in addition to wet cleaning, dust can be sucked without operating the drive device of the accessory, and power-saving operation of the suction wiper is made possible.

According to a third teaching, according to the present invention, the above object is achieved by a method for wet cleaning a surface, wherein a cleaning element is fixed to a carrier element and wherein the carrier element is arranged in a housing, in which method the surface is wet cleaned by the cleaning element, in which method the carrier element is moved relative to the housing during the wet cleaning, in which method the position of the carrier element relative to the housing is determined, in which method an electrical signal is generated as a function of the moisture content of the cleaning element by means of two sensor electrodes arranged on the carrier element, and in which method the generated electrical signal is transmitted to two receiving electrodes arranged on the housing by capacitive coupling.

In this way, the method of wet cleaning a surface can be implemented in a technically simple manner, since the signal generated as a function of the moisture content of the cleaning element is transmitted to the housing by capacitive coupling and no complex radio transmission is required. Furthermore, by improving the detection and transmission of moisture content, wet cleaning of the surface may be improved.

Furthermore, the method according to the invention enables an effective wet wiping of a surface to be cleaned, such as a floor, by means of the movement of the carrier element relative to the housing during wet cleaning. Thereby, the liquid delivered by the cleaning element to the floor can be evenly distributed over the floor. Furthermore, the removal of dirt adhering to the surface to be cleaned can be simplified.

Furthermore, the determination of the position of the carrier element relative to the housing makes it possible to take into account the movement of the carrier element when transmitting a signal generated by the sensor electrode as a function of the moisture content of the cleaning element to the receiving electrode of the housing. In this way, a more reliable signal transmission and thus an improved wet cleaning is achieved. In particular, the position of the support element relative to the housing can be determined as a function of time. The position is preferably determined by means of a hall sensor.

In this way, changes in the movement of the cleaning elements can be detected. For example, if a slowing of the movement of the carrying element is detected while the power of the movement-inducing drive remains constant, this may indicate an increase in the static friction of the carrying element relative to the floor. For example, an increase in static friction may be caused by sticky dirt at locations on the floor where motion slowing is detected. This location of the floor covered with sticky dirt can thus be cleaned particularly intensively, that is to say over a longer period of time or with an increased speed of movement.

Furthermore, active electronic components as well as wireless power supply and the circuit complexity resulting therefrom can be avoided on the carrier element by components which move relative to the housing during the method.

In the following, different embodiments of the attachment, suction wiper and method are described, wherein each embodiment is suitable for the attachment, suction wiper and method. Furthermore, the individual embodiments can be combined with one another.

In a first embodiment of the attachment, two coupling electrodes are provided on the side of the carrier element facing away from the sensor electrodes, wherein one of the coupling electrodes is in each case capacitively coupled to one of the receiving electrodes and wherein one of the coupling electrodes is in each case electrically conductively connected to one of the sensor electrodes.

In this way, the capacitive coupling of the capacitive sensor with the receiving electrode of the accessory may be improved, so that possible interference with the signal generated by the capacitive sensor and transmitted to the accessory electronics may be reduced and the sensitivity of the capacitive sensor may be improved. The signal generated by the capacitive sensor may be transmitted from the sensor electrode to the conductively connected coupling electrode. Preferably, one of the coupling electrodes is capacitively coupled with one of the receiving electrodes, respectively, such that one of the coupling electrodes forms a capacitor with one of the receiving electrodes, respectively. A series connection of three capacitors is thereby preferably realized: a capacitor formed by one of the receiving electrodes and one of the coupling electrodes, a capacitor formed by two sensor electrodes, and a capacitor formed by the other of the receiving electrodes and the other of the coupling electrodes. In this case, the capacitance value of the middle capacitor of the three series-connected capacitors, i.e., the capacitance value of the capacitive sensor formed by the two sensor electrodes, is affected by the moisture content of the cleaning element attached to the carrying element.

By providing the coupling electrode, the sensitivity of the capacitive sensor is significantly increased. The sensor electrodes of the capacitive sensor can in particular be mounted directly on the cleaning element.

In addition to the electrodes already mentioned, further electrodes may be provided, for example further sensor electrodes, further coupling electrodes and/or further receiving electrodes. For example, the number of sensor electrodes, coupling electrodes and receiving electrodes can be doubled in each case, so that a further series connection of three capacitors can be used for the signal transmission of the signal generated by the capacitive sensor as a function of the moisture content of the cleaning element. The redundant further series connection of the further capacitors improves the reliability and accuracy of the moisture measurement of the cleaning element.

Further, it is also possible to increase only the number of sensor electrodes, coupling electrodes, or receiving electrodes. If a large number of measurements are available, an average measurement can be determined therefrom, thereby improving measurement accuracy.

It is also possible to place further electrodes, for example further sensor electrodes, at further locations of the cleaning element spatially remote from the existing sensor electrodes and to provide further coupling electrodes and/or receiving electrodes for capacitively coupling the capacitive sensor to the housing of the accessory. In this way, the moisture content at different locations on the cleaning element can be determined, and the spatial resolution of the moisture measurement of the cleaning element can be improved. Therefore, the moisture content of the cleaning member can be determined more reliably, especially in the case of using a large-area cleaning member.

The carrier element can preferably be designed as a plate. Furthermore, the sensor electrode can be provided on the underside of the carrier element, i.e. on the side facing the floor to be cleaned, wherein the cleaning element is also arranged thereon, and the coupling electrode can be provided on the upper side of the carrier element, i.e. on the side facing the attachment. Alternatively, the coupling electrode can also be arranged on a side face of the carrier element.

The carrier element can also be designed as a roller, on the circumferential side of which the cleaning elements can be arranged. The sensor electrodes may be arranged at both ends of the roller, preferably between the cleaning element and the main body of the roller, such that the electric field between the two sensor electrodes is at least partially influenced by moisture in the cleaning element.

In general, by providing the coupling electrode in addition to the sensor electrode on the side of the carrier element facing away from the sensor electrode, the design of the carrier element, in particular the movement of the carrier element relative to the housing, can be made more flexible.

In a further embodiment of the attachment, the sensor electrode is in direct contact with the cleaning element.

In this way, the sensitivity of the cleaning element can be significantly increased, since the sensor electrode can move with the cleaning element and thus a constant distance between the sensor electrode and the cleaning element can be ensured. In addition to the moisture content of the cleaning element, the capacitance value of a capacitive sensor is typically also influenced by the characteristics of other objects located in the electric field between the sensor electrodes. For example, if there is an air gap or a portion of the carrier element in the electric field between the sensor electrodes, the moisture content of the air in the air gap and the thickness and properties of the carrier element material can affect the capacitance value. As the thickness of the carrier member increases and the size of the air gap increases, the electrical signal generated by the capacitive sensor depending on the moisture content of the cleaning member becomes weaker. If the sensor electrode is in direct contact with the cleaning element, preferably in such a way that there is no air gap between the cleaning element and the sensor electrode, the influence of the moisture content of the cleaning element on the capacitance value increases significantly compared to disturbing influences, for example due to the presence of air gaps or parts of the carrying element protruding into the electric field of the sensor electrode.

In a further embodiment of the attachment, a control unit is provided and is designed to determine the moisture content of the cleaning element from the signals generated by the sensor electrodes.

By determining the humidity of the cleaning element, a situation regarding the cleaning process performed by the cleaning element can be obtained without the user having to take manual measures to control the humidity. For example, the user may be informed of the wetness of the cleaning element. The notification to the user may be made through a display.

The wetness of the cleaning element may be determined, for example, based on the thickness or material properties of the cleaning element used, e.g., the cleaning element. Information about the amount of liquid transferred to the floor during cleaning can also be obtained from the determined humidity.

By providing a control unit, when a change in the movement of the carrier element is detected, for example when the drive device is stopped, and when an unplanned change in the movement of the carrier element occurs, the control unit can automatically trigger the action without the user having to intervene. For example, the drive means may be stopped. It is also possible to increase the power of the drive device in order to keep the speed of movement of the carrying element constant, for example in the case of particularly dirty and sticky floors.

Additionally or alternatively, the user may be notified of an unplanned change in movement of the load bearing element. It is generally possible to provide for the user to be informed of the movement of the carrier element detected by the sensor, for example by means of a display or in some other way to convey information to the user about the speed of movement of the carrier element.

In a further embodiment of the attachment, a wetting device having a liquid source and a controllable valve for wetting the cleaning element is provided, and the control unit is designed to adjust the wetting of the cleaning element by the wetting device as a function of the moisture content.

In this way, an automatic wetting of the cleaning element can be triggered, without the user having to take manual measures to wet the cleaning element. The attachment can continue to operate without having to interrupt the cleaning process for subsequent wetting. For example, the determined humidity may be compared with a reference value and a valve for wetting the cleaning element may be controlled depending on the comparison. For example, if the determined humidity is below the reference value, the valve is preferably opened for subsequent wetting of the cleaning element. For example, if the determined humidity exceeds the reference value, the valve preferably remains closed and the cleaning element is not subsequently wetted. In the case of a determined humidity which is very low compared to the reference value, it is also possible to open the valve for a longer time and/or to open the valve for a greater liquid flow than in the case of a determined humidity which is only slightly below the reference value.

In a corresponding embodiment of the method, the moisture content of the cleaning element is determined from the electrical signal, the moisture content is compared with a reference value, and the cleaning element is subsequently wetted as a function of the comparison result.

In this way, the amount of liquid delivered to the cleaning element can be influenced in a targeted manner. In this way, the cleaning process can be performed by automatic subsequent wetting of the cleaning element without the user having to manually subsequently wet the cleaning element.

Alternatively, it is also possible to inform the user only of the result of the comparison of the determined humidity with the reference value, for example by means of a display or by means of another signal, for example an audio signal. For example, the user may be notified that the humidity is too low. In this way, the user can continue to perform the cleaning process until the humidity of the cleaning element drops below a certain level.

In particular, it is possible to subsequently wet the cleaning element continuously, for example by permanently slightly opening the valve. The control unit may close the valve if a certain reference value of the determined humidity is exceeded.

The reference value may be set by a user through the control unit. The reference value may also be recalled from an external memory, for example by wireless communication. The reference value may also be called by the control unit from another device, such as a cell phone or a computer, or from an external server. For invoking the external information, wireless communication, such as a WLAN or bluetooth connection, may preferably be used.

In a further preferred embodiment of the accessory, a memory can be provided. For example, the reservoir may have different reference values for different floor coverings. In this way, the humidity can be selected specifically for a particular floor covering, for example, in order to prevent sensitive floor coverings from being damaged by cleaning with excessively humid cleaning elements. Different reference values may also be provided for different types of cleaning elements. For example, a reference value for the wiping mop and a reference value for the microfiber cloth may be set. Different reference values may also be provided for cleaning elements of different material thicknesses.

In a corresponding embodiment of the suction wiper, a reservoir is provided on the attachment. A reservoir or an additional reservoir may also be provided on the cleaner. Usually, a control unit may also be provided on the cleaner. If the control unit is provided on the cleaner, the construction of the attachment can be made more compact.

A wetting apparatus with a liquid source may be provided on the attachment. Furthermore, a source of cleaning agent can be provided on the wetting apparatus, wherein for example a high concentration of cleaning agent is provided. If a source of cleaning agent is provided, a flow connection to a flow connection connecting the source of liquid to the cleaning element may be provided. Thereby, for example, an amount of cleaning agent can be delivered to the cleaning element in dependence of the humidity and controlled by the control unit. In this way, the concentration of the cleaning agent in the cleaning member can be controlled. For example, if there is a particular tough soil or a particular type of soil on the floor to be cleaned, the user can give a higher concentration of cleaner in the cleaning elements.

If a slowing down of the movement of the carrier element is detected with the power of the drive device remaining constant, a stronger subsequent wetting of the cleaning element and/or an increase in the detergent addition from the detergent source can be initiated, for example by the control unit. Particularly dirty areas of the floor to be cleaned can thereby be cleaned more effectively.

In a corresponding embodiment of the suction wiper, a wetting device with a liquid source is provided on the attachment. The wetting apparatus may also have an additional source of cleaning agent. Alternatively, a wetting apparatus with a liquid source may be provided on the vacuum cleaner. In this way, the accessory can be designed more compact. In addition, a source of cleaning agent may be provided on the cleaner.

In a further embodiment of the accessory, the control unit is designed to determine the signal in a specific spatial position of the carrier element relative to the housing.

In this way the moisture content of the cleaning element can be determined more reliably. In addition to the medium through which the electric field between the electrodes penetrates, the shape and position of the electrodes relative to each other typically also affect the capacitance value of the capacitor formed by the electrodes. If the signal is determined in a specific spatial position of the carrier element relative to the housing, the influence of the relative displacement of the electrodes on the capacitive coupling of the electrodes of the carrier element to the electrodes of the accessory can be minimized. For example, the effect of a change in the relative position of the sensor electrode with respect to the receive electrode on the capacitive coupling may be minimized.

For example, if a coupling electrode is provided, the effect of a change in the relative position of the coupling electrode with respect to the receiving electrode on the capacitive coupling can be minimized. Overall, the sensitivity and the measurement accuracy of the capacitive sensor can be increased in this way.

In a corresponding embodiment of the method, the moisture content of the cleaning element is determined in a specific position of the carrier element relative to the housing.

In this way, the moisture content of the cleaning element can be determined independently of the movement of the cleaning element. The influence of the relative movement of the carrying element with respect to the housing of the accessory and thus the influence of the electrodes participating in the capacitive coupling between the accessory and the housing on the determination of the humidity can be minimized.

In a further embodiment of the attachment, the control unit is designed to regulate the wetting of the cleaning element by the wetting device in at least one specific position of the carrier element relative to the housing.

By wetting the cleaning element in a specific location of the carrier element or in several specific locations of the carrier element, the wetting of the cleaning element and the wet cleaning of the floor can be made more uniform.

In a corresponding embodiment of the method, the cleaning element is wetted subsequently in at least one specific position of the carrier element relative to the housing.

Provision can also be made for a cleaning agent to be added from a cleaning agent source or to increase its addition in a specific position of the carrier element. This makes it possible in particular to design the distribution of the cleaning agent in the cleaning element more uniformly.

In a further embodiment of the method, the time and the position of the carrier element relative to the housing are assigned to the determined humidity and the determined humidity, the time and the position are stored in a memory.

In this way, the change in humidity over time can be tracked. It is thereby also possible to detect changes over time in the movement of the carrier element relative to the housing in dependence on the determined humidity. Based on the development of humidity over time, it is possible, for example, to detect changes in the hygroscopicity of the cleaning element and the release of moisture from the cleaning element to the floor to be cleaned. For example, if the humidity drops faster than the previous cleaning process, this may indicate that the cleaning elements are worn. For example, the material of the cleaning elements may wear as the number of cleaning processes increases. The cleaning cloth used as the cleaning element becomes sparse after frequent use, thereby losing liquid more quickly. A reduction in the material thickness of the cleaning element has a negative effect on the sensitivity of the sensor, since the cleaning element has less influence on the electric field between the sensor electrodes in this case.

In particular, the wear of the cleaning element can be determined in this way in order to inform the user of the need to replace the cleaning element. For example, the control unit may provide information about the status of the cleaning element via a display device. In general, it is also possible to adapt the subsequent wetting of the cleaning element to the state of the cleaning element.

For example, it may be arranged to increase the subsequent wetting frequency. The display device may also serve as an input device by which a user can control the control unit, for example by which the user can specify the reference value.

A memory is preferably provided in the accessory for storing the determined humidity, time and location. Alternatively, a memory may be provided on the cleaner, or an external memory, such as an external server, may be provided. In general, the memory for storing the determined humidity, time and location may be the same memory on which the humidity reference values of the different floor coverings are stored. In addition to the reference value of the floor covering, different reference values for different cleaning elements may also be stored in the memory.

Furthermore, by assigning the determined positions of the carrying elements to different times, the development of the movement over time and the resulting change in movement can be stored in a memory. It is also possible to determine different speeds for different floor coverings and store these correspondences in a memory. For example, the user may select the floor covering via communication with the control unit through an input device or through an external device. Then, depending on the floor covering selected, the control unit may set reference values for the speed of movement of the carrier element and the humidity in the cleaning element corresponding to the floor covering.

In a further embodiment of the attachment, the drive is designed as an eccentric drive.

By providing the drive means in the form of an eccentric drive, the carrier element can perform an eccentric movement relative to the housing. It has been found that in this way a wet wiping of the floor can be designed particularly effectively and that the liquid which is transferred to the floor by the cleaning element is distributed particularly evenly over the floor.

By means of the sensor arranged on the housing, the position of the carrier element relative to the housing can be determined, in particular as a function of time, and thus the eccentric movement of the carrier element relative to the housing can be tracked. The influence of the eccentric movement of the carrier element on the capacitive coupling is thus taken into account, so that a determination of the moisture content is achieved.

The cleaning element is preferably moved in an eccentric motion on a closed curved path. If the signal is determined in a particular spatial position of the carrying element relative to the housing, the signal can be determined at a particular point on the closed curve path of the cleaning element.

In a corresponding embodiment of the method, the carrier element is moved eccentrically relative to the housing during wet cleaning, wherein the position of the carrier element relative to the eccentric shaft is determined and wherein the moisture content of the cleaning element is determined in a specific position of the cleaning element relative to the movement shaft, in particular the eccentric shaft.

By means of the eccentric movement, the liquid and the cleaning agent which are transferred to the floor by the cleaning element during wet cleaning can be distributed evenly over the floor. Furthermore, the removal of dirt adhering to the surface to be cleaned can be simplified.

By determining the position of the carrier element relative to the eccentric shaft, it is possible to take into account the eccentric movement of the carrier element when transmitting the signal generated by the sensor electrode as a function of the moisture content of the cleaning element to the receiving electrode of the housing. The position of the carrier element relative to the eccentric shaft can be determined in particular as a function of time.

In this way, a change in the eccentric movement of the cleaning element can be detected. For example, if a slowing of the movement of the carrying element is detected while the power of the drive causing the eccentric movement remains constant, this may indicate an increase in the static friction of the carrying element relative to the floor. For example, where a slowing of the eccentric motion is detected on the floor, an increase in the static friction may be caused by sticky dirt. This location of the floor covered with sticky dirt can thus be cleaned particularly intensively, that is to say over a long period of time or with an increased eccentric movement speed.

Furthermore, the moisture content of the cleaning element can be determined in this way independently of the eccentric movement of the cleaning element.

Drawings

The invention is explained in more detail below with the aid of embodiments with reference to the drawings. In the figure:

figure 1 shows a first embodiment of an attachment for a cleaning appliance in a schematic side sectional view,

figure 2 shows a first embodiment of an attachment for a cleaning appliance in a schematic bottom view,

figure 3 shows an embodiment of a suction wiper for wet cleaning of a surface in a schematic side sectional view,

FIG. 4 shows an example of a measurement signal generated by a capacitive sensor with and without capacitive coupling of a sensor electrode with a receiving electrode arranged on a housing, an

Fig. 5 shows an example of an accessory for a cleaning device of the prior art in a schematic side sectional view.

Detailed Description

In the following description of various embodiments according to the present invention, like parts have like reference numerals even though the parts in the respective embodiments may differ in size or shape.

Figure 5 shows an example of an attachment 2 for a cleaning appliance of the prior art. The accessory 2 has a housing 4 with a carrying element in the form of a base plate 6. The base plate 6 can be designed to be movable, for example pivotable, relative to the housing 4. The housing 4 is provided with rollers 12 by means of which the accessory 2 can be moved over the floor. The housing 4 also has a connecting element 10 for connecting with a cleaning appliance. A cleaning element in the form of a cleaning cloth 8 is fixed to the floor plate 6. In addition, a capacitive sensor is provided on the housing 4 of the attachment 2.

The capacitive sensor has a first sensor electrode 16 and a second sensor electrode 18. The

sensor electrodes

16, 18 are connected to a control unit 14 arranged on the housing 4 of the accessory 2. The

sensor electrodes

16, 18 are not connected to each other in an electrically conductive manner, and the capacitance value of the capacitive sensor is influenced by the electric field present between the sensor electrodes. The electric field is influenced by the liquid content of the cleaning cloth 8. If a high-frequency alternating voltage is applied to the

sensor electrodes

16, 18, the

sensor electrodes

16, 18 generate a signal in response, the frequency of which depends on the object located in the region of the electric field, in particular on the liquid content of the cleaning cloth 8.

In addition to the cleaning cloth 8, other objects located in the electric field area, such as the floor plate 6 and the air gaps between the

sensor electrodes

16, 18 and the floor plate 6, also influence the capacitance value of the capacitive sensor. As the distance between the

sensor electrodes

16, 18 and the cleaning cloth 8 increases, the sensitivity of the capacitive sensor decreases. The relative movement of the cleaning cloth 8 with respect to the

sensor electrodes

16, 18, for example due to the oscillating movement of the floor plate 6 which takes place during the cleaning process, also leads to a reduction in the sensitivity of the capacitive sensor.

Fig. 1 now shows a first embodiment of an attachment 2 for a cleaning appliance according to the invention in a schematic sectional side view. As in the example of prior art fig. 5, the accessory 2 has a housing 4 with a carrying element in the form of a bottom plate 6. A drive means, here in the form of an eccentric drive 30, is provided on the housing 4 for moving the bottom plate 6 relative to the housing 4. In particular, the base plate 6 can be driven relative to the housing 4 in the form of an eccentric movement about the eccentric shaft 32.

On the housing 4 there are rollers 12 for moving the accessory 2 on the floor. For example, the attachment 2 may be pushed on the floor by a user via the rollers 12, or it may be driven in a self-propelled manner by further drive means (not shown). The housing 4 also has a connecting element 10 for connecting with a cleaning device. A cleaning element in the form of a cleaning cloth 8 is fixed to the floor plate 6.

A control unit 14 having a memory 38, a microprocessor 40 and a communication means 36 is provided on the accessory 2. The execution of the commands stored in the memory 38 causes, on the microprocessor 40, the control of the electrical components of the accessory 2 connected to the control unit 14. The control unit 14 is also connected to a sensor 42 for determining the position of the soleplate 6 relative to the housing 4. The sensor 42 is preferably designed as a hall sensor and detects the movement of a magnet 44 arranged on the base plate 6.

A wetting device 46 having a liquid source 48 and a detergent source 52 is provided in the attachment 2. The cleaning cloth 8 can be moistened with liquid from the liquid source 48 via a flow-through connection in the form of a supply line 54 connected to the moistening device 46 and by means of the controllable valve 50. Additionally, a cleaning agent from the cleaning agent source 52 may be added to the liquid. The valve 50 as well as the liquid source 48 and the detergent source 52 may be controlled by the control unit 14 via the wetting apparatus 46.

On the side of the floor plate 6 facing the cleaning cloth 8, two

sensor electrodes

16, 18 are arranged. The

sensor electrodes

16, 18 are in direct contact with the cleaning cloth 8. One of the

sensor electrodes

16, 18 is in each case electrically conductively connected to one of the two

coupling electrodes

20, 22 arranged on the side 28 of the floor panel 6 facing away from the cleaning cloth 8. One of the two

coupling electrodes

20, 22 is capacitively coupled to one of two receiving

electrodes

24, 26, respectively, which two receiving

electrodes

24, 26 are arranged on the side of the housing 4 of the accessory 2 facing the base plate 6.

The receiving

electrodes

24, 26 are connected to the control unit 14. In the present case, one of the two

coupling electrodes

20, 22 forms a capacitor with one of the two receiving

electrodes

24, 26. Together with the capacitor formed by the capacitive sensor (sensor electrodes 16, 18), there is thus a series connection of three capacitors. In the present case, the capacitance value of the capacitive sensor is influenced by the electric field present between the

sensor electrodes

16, 18. The electric field is influenced by the liquid content of the cleaning cloth 8.

If a high-frequency alternating voltage 5 is applied to the

sensor electrodes

16, 18 by the control unit 14 of the attachment 2, the

sensor electrodes

16, 18 generate a signal in response, the frequency of which depends on the liquid content of the cleaning cloth 8. The disturbing influence of other objects located in the vicinity of the

sensor electrodes

16, 18 is significantly reduced compared to the arrangement of the capacitive sensor of fig. 5, because there is direct contact between the

sensor electrodes

16, 18 and the cleaning cloth 8. Based on the change in the frequency of the signal generated by the capacitive sensor, the control unit 14 can determine the humidity of the cleaning cloth 8. The microprocessor 40 may compare the humidity to a reference value retrieved from the memory 38. Based on the comparison, the control unit 14 can trigger a subsequent wetting of the cleaning cloth 8 by the wetting device 46. By means of the hall sensor 42, the moisture content of the cleaning cloth 8 can be determined in a specific position of the floor plate 6 relative to the housing 4, so that the sensitivity of the capacitive sensor is increased.

The user may control the control unit 14 by means of a display and input device on the handpiece of the cleaning appliance (not shown). The control unit 14 may also be controlled by means of the communication means 36, for example with the aid of a mobile phone. For example, the user may specify different reference values for the allowable humidity of different floor coverings and purposely influence the amount of liquid from liquid source 48 for subsequent wetting and the amount of detergent used supplied by detergent source 52.

Fig. 2 shows an embodiment of the attachment 2 for a cleaning appliance shown in fig. 1 in a schematic bottom view. The accessory 2 has a housing 4 with a carrying element in the form of a bottom plate 6 which is movable relative to the housing 4. On the housing 4 there are rollers 12 for moving the accessory 2 on the floor. The housing 4 also has a connecting element 10 for connecting with a cleaning appliance.

On the side of the base plate 6 facing away from the housing 4, a receiving region 34 for the cleaning elements 8 is provided. In the receiving region 34, a capacitive sensor is arranged, which has two

sensor electrodes

16, 18, a circular outer electrode 16 with an inner radius RA1 and an outer radius RA2 and a circular inner electrode arranged in the center of the outer electrode with a radius RI, wherein RI is smaller than RA1, so that a positive distance exists between the two

circular sensor electrodes

16, 18. In the illustrated embodiment of the attachment 2, the

sensor electrodes

16, 18 are in direct contact with a cleaning cloth (not shown).

The receiving area 34 also has a magnet 44. By means of the magnet 44, the position of the base plate 6 relative to the housing 4 can be determined by a hall sensor (not shown) located on the housing 4 of the accessory 2.

Fig. 3 shows an embodiment of a suction wiper for a wet cleaning surface 58 with a vacuum cleaner 60 and an attachment 2 as shown in fig. 1 and 2 in a schematic sectional side view.

The attachment 2 has a housing 4, a connecting element 10 for connection with a vacuum cleaner 60 and a carrying element in the form of a sole plate 6 on which a cleaning element 8 is arranged. A capacitive sensor with

sensor electrodes

16, 18 is arranged on the bottom plate 6. The capacitive sensor is capacitively coupled to the accessory 2 via

coupling electrodes

20, 22 arranged on a side 28 of the base plate 6 facing away from the

sensor electrodes

16, 18 and receiving

electrodes

24, 26 arranged on the housing 4 of the accessory 2. A roller 12 is provided on the attachment 2 for moving the attachment 2 over a surface 58 to be cleaned.

The control unit 14 is arranged in the vacuum cleaner 60 and is constructed to determine the humidity corresponding to the moisture content in the cleaning element 8 from the signal generated by the capacitive sensor and transmitted via the communication connection 56. A wetting apparatus 46 with a liquid source 48, a detergent source 52 and a controllable valve 50 is also provided, which wetting apparatus is constructed for control by the control unit 14 in dependence on the determined humidity. The cleaning element 8 can be wetted subsequently via the wetting device 46 by means of the flow-through connection 54.

Fig. 4 shows an example of a measurement signal generated by a capacitive sensor with and without capacitive coupling of the sensor electrodes to the receiving

electrodes

24, 26 arranged on the housing 4.

In the graph shown in fig. 4, the course over time of the sensor frequency measured by the capacitive sensor, for example in the case of capacitive coupling of the

sensor electrodes

16, 18 to the receiving

electrodes

24, 26 arranged on the housing 4 by the

coupling electrodes

20, 22 as shown in fig. 1, and by the

sensor electrodes

16, 18 attached to the attachment 2 without capacitive coupling as shown in fig. 5, is shown during the cleaning process. In addition to the course of the measured

sensor frequencies

62, 72, the course of the

mean values

64, 74 of the measured

sensor frequencies

62, 72 is also shown, respectively. At the start of the measurement, at time t 0 seconds, the cleaning cloth 8 has a liquid content of 60g of water. At the end of the measurement, at t 120 seconds, the cleaning cloth 8 has a liquid content of 30g of water.

During cleaning, the liquid content in the cleaning cloth 8 was reduced from 60g to 30g, a reduction of 30 g. This reduction in water content results in a change in the capacitance value of the capacitive sensor, and thus a change in the frequency of the

signal

62, 72 generated by the capacitive sensor. When the water content in the cleaning cloth 8 decreases from 60g to 30g as a result of the cleaning process, the relative frequency variation of the capacitive sensor, which is represented by the average value 64 when the sensor electrodes are capacitively coupled via the coupling electrodes, is 14%, based on the absolute frequency 66 at t ═ 0 seconds. In contrast, when the water content in the cleaning cloth 8 decreases from 60g to 30g as a result of the cleaning process, the relative frequency change, expressed as the mean value 74, of the capacitive sensor without capacitive coupling is only 1%, based on the absolute frequency 76 at t ═ 0 seconds. By means of the capacitive coupling of the capacitive sensor, in particular by the provision of the

coupling electrodes

20, 22, the sensitivity of the capacitive sensor can thus be increased significantly.

Claims

1. An attachment (2) for a cleaning device (60), the attachment having

-a housing (4),

-a carrier element (6) for accommodating a cleaning element (8) provided for wet cleaning and

two sensor electrodes (16, 18) arranged on the carrier element (6),

-wherein the sensor electrodes (16, 18) are configured to generate an electrical signal dependent on the moisture content in the cleaning element (8),

-wherein drive means (30) are provided for moving the carrying element (6) relative to the housing (4),

it is characterized in that the preparation method is characterized in that,

the sensor electrodes (16, 18) are capacitively coupled to two receiving electrodes (24, 26) arranged on the housing (4) and

-providing a sensor (42) for determining the position of the carrying element (6) relative to the housing (4).

2. An attachment according to claim 1, in which,

it is characterized in that the preparation method is characterized in that,

-providing two coupling electrodes (20, 22) on a side (28) of the carrier element (6) facing away from the sensor electrodes (16, 18),

-wherein one of the coupling electrodes (20, 22) is capacitively coupled with one of the receiving electrodes (24, 26) respectively and

-wherein one of the coupling electrodes (20, 22) is electrically conductively connected with one of the sensor electrodes (16, 18), respectively.

3. An accessory according to claim 1 or 2,

it is characterized in that the preparation method is characterized in that,

the sensor electrodes (16, 18) are in direct contact with the cleaning element (8).

4. An accessory according to any one of claims 1 to 3,

it is characterized in that the preparation method is characterized in that,

-providing a control unit (14) and

-the control unit (14) is configured to determine the humidity of the cleaning element (8) from the signal generated by the sensor electrode (16, 18).

5. An attachment according to one of the preceding claims 4,

it is characterized in that the preparation method is characterized in that,

-providing a wetting device (46) having a liquid source (48) and a controllable valve (50) for wetting the cleaning element (8), and

-the control unit (14) is configured for adjusting the wetting of the cleaning element (8) by the wetting device (46) as a function of the humidity.

6. Accessory according to any one of claims 4 to 5,

it is characterized in that the preparation method is characterized in that,

-the control unit (14) is configured to determine the signal in a specific spatial position of the carrying element (6) relative to the housing (4).

7. Accessory according to any one of claims 1 to 6,

it is characterized in that the preparation method is characterized in that,

the drive device (30) is designed as an eccentric drive.

8. Suction wiper for wet cleaning a surface (58), having

-a vacuum cleaner (60), and

-an accessory (2) according to any one of claims 1 to 7,

-wherein the accessory (2) is configured for connection with the vacuum cleaner (60).

9. Method for the wet cleaning of a surface (58),

-wherein the cleaning element (8) is fixed to the carrier element (6) and wherein the carrier element (6) is arranged in the housing (4),

-in the method, a surface (58) is wet cleaned by the cleaning element (8),

-in the method, the carrier element (6) is moved relative to the housing (4) during wet cleaning,

-in the method, the position of the carrying element (6) relative to the housing is determined,

-in the method, an electrical signal is generated as a function of the moisture content of the cleaning element (8) with two sensor electrodes (16, 18) arranged on the carrier element (6), and

-in the method, the generated electrical signal is transmitted to two receiving electrodes (24, 26) arranged on the housing (4) by capacitive coupling.

10. The method of claim 9, wherein the first and second light sources are selected from the group consisting of,

-in the method, the humidity of the cleaning element (8) is determined from the electrical signal,

-in the method, the humidity is compared with a reference value, and

-in the method, the cleaning element (8) is subsequently wetted according to the result of the comparison.

11. The method according to claim 9 or 10,

-in the method, the wetness of the cleaning element (8) is determined in a specific position of the carrying element (6) relative to the housing (4).

12. The method of claim 11, wherein the first and second light sources are selected from the group consisting of,

-in the method, the time and the position of the carrying element (6) relative to the housing (4) are assigned to a determined humidity, and

-in the method, the determined humidity, the time and the location are stored in a memory (38).

13. The method according to claim 11 or 12,

-in the method, the carrier element (6) is moved eccentrically with respect to the housing (4) during wet cleaning,

-in the method, the position of the carrier element (6) relative to the eccentric shaft (32) is determined, and

-in the method, the wetness of the cleaning element (8) is determined in a specific position of the cleaning element (8) relative to a movement axis, in particular an eccentric axis (32).