Vacuum cleaner with two turbines and operating method for same

Abstract

The invention relates to a vacuum cleaner with a first turbine and a second turbine, wherein the turbines are designed to generate a suction flow for suctioning in dust. The vacuum cleaner has a valve arrangement, which valve arrangement is designed to allow a suction flow to flow through the turbines one after another or parallel to one another. With the invention, the operation of the vacuum cleaner can be made more variable by providing a broader characteristic suction curve of the vacuum cleaner. This is made possible, in particular, by the fact that the turbines of the vacuum cleaner can be operated in series or parallel to one another, allowing the suction properties of the vacuum cleaner to be optimally adapted to different applications. The invention also enables the vacuum cleaner to maintain a suction operation when a filter unit of the vacuum cleaner is being cleaned. The invention also relates to a method for operating a vacuum cleaner with two turbines, wherein the vacuum cleaner can be operated in series or parallel operation.

Description

[0001] Hilti Corporation in Schaan

[0002] Principality of Liechtenstein

[0003] VACUUM CLEANER WITH TWO TURBINES AND OPERATING METHOD THEREFOR

[0004] The present invention relates to a vacuum cleaner with a first turbine and a second turbine, wherein the turbines are configured to generate a suction flow for sucking in dust. The vacuum cleaner has a valve arrangement, wherein the valve arrangement is configured to allow a suction flow to flow through the turbines sequentially or in parallel. With the invention, the operation of the vacuum cleaner can be made more variable by providing a broader characteristic suction curve for the vacuum cleaner. This is made possible in particular by the fact that the turbines of the vacuum cleaner can be operated in series or in parallel, and the suction properties of the vacuum cleaner can thus be optimally adapted to different applications. Furthermore, the invention makes it possible to maintain suction operation of the vacuum cleaner when a filter unit of the vacuum cleaner is being cleaned.In a second aspect, the invention relates to a method for operating a vacuum cleaner with two turbines, wherein the vacuum cleaner can be operated in series or parallel operation.

[0005] Background of the invention:

[0006] Vacuum cleaners are known in the art that can generate a suction current, which can then suck in dust. A turbine is typically used to generate the suction current, which can create a negative pressure. Vacuum cleaners are well known in the household sector, for example, for vacuuming floors, carpets, or furniture. However, vacuum cleaners are also used on construction sites to extract dust and particles generated when working with machine tools. This can reduce the dust exposure to which a machine tool user is exposed, making a valuable contribution to protecting the user's health.

[0007] State-of-the-art vacuum cleaners often suffer from the disadvantage that they are typically designed for a specific application, and the associated suction and operating characteristics cannot be changed during the lifetime of the vacuum cleaner. When designing a vacuum cleaner, a selection decision often has to be made, for example, whether the vacuum cleaner should generate a high air flow velocity or a strong vacuum, since a combination of these different properties is often not possible.

[0008] For example, EP 2 421 630 A1 discloses a vacuum cleaner with two suction units, wherein the suction units in the vacuum cleaner of EP 2 421 630 A1 are flowed through in parallel by a suction flow. The disadvantage of such a parallel arrangement is that it only increases the volume flow, not the pressure level.

[0009] Vacuum cleaners often have filters or a filter unit that must be cleaned at regular intervals to ensure the suction flow can continue through the filter. With many conventional vacuum cleaners, the vacuuming operation must be briefly interrupted to clean the filter or filter unit. This is often accompanied by a drop in the vacuum inside the vacuum cleaner, which can interrupt or weaken the suction flow.

[0010] The object underlying the present invention is to overcome the above-described deficiencies and disadvantages of the prior art and to provide a vacuum cleaner that optimally covers a wide range of applications and whose suction and operating characteristics can be flexibly changed or adjusted during operation. A further aim of the invention is that the vacuum cleaner's suction operation can be continued even while filter cleaning is being performed.

[0011] The problem is solved by the subject matter of the independent claims. Advantageous embodiments of the subject matter of the independent claims can be found in the dependent claims.

[0012] Description of the invention:

[0013] According to the invention, a vacuum cleaner is provided with a first turbine and a second turbine, wherein the turbines are configured to generate a suction flow for sucking in dust. The vacuum cleaner has a valve arrangement, wherein the valve arrangement is configured to allow a suction flow to flow through the turbines sequentially or in parallel. With the invention, by providing the two turbines, which can be operated either in series or in parallel, a vacuum cleaner with an extended characteristic suction curve can be provided, so that a multitude of applications can be covered by the vacuum cleaner. Within the meaning of the invention, it is preferred that switching between series operation and parallel operation of the turbines takes place automatically.For example, the valve arrangement of the vacuum cleaner can switch from series operation to parallel operation when a vacuum limit is exceeded or undershot. In other words, it may be preferred within the meaning of the invention for switching between series and parallel operation of the vacuum cleaner to occur depending on the vacuum conditions in the vacuum cleaner.

[0014] For the purposes of the invention, the term "dust" is preferably used as a generic term for various types of suction material. For example, "dust" can include solids and / or liquids. In other words, the suction material can be dry and dust-like, formed from a liquid, or a mixture of dry suction material, such as dust, drilling dust, particles, and a liquid, such as water, which is used, for example, as rinsing or cooling water on a construction site when performing work with machine tools.

[0015] According to the invention, it is preferred that the vacuum cleaner comprises at least one sensor for determining operating data of the vacuum cleaner. Furthermore, the vacuum cleaner can comprise a control device for evaluating the operating data of the vacuum cleaner determined by the at least one sensor, wherein the control device is configured to control the vacuum cleaner depending on the operating data determined by the at least one sensor. The operating data of the vacuum cleaner can, in particular, be negative pressure values ​​or ratios within the vacuum cleaner. In the context of the invention, however, it can also be preferred that motor parameters, filter parameters, particle or flow velocities and / or particle concentrations are measured, without being limited thereto. The operating data can preferably also be referred to as operating parameters.To determine the operating parameters, in particular the vacuum conditions in the vacuum cleaner, the vacuum cleaner can be equipped with suitable sensors. The sensors of the sensor system can, for example, be designed to determine a negative pressure in the vacuum cleaner's collecting container or in the various suction line sections, such as the first and second suction sections, the suction channel, and / or the first and second outlet sections. Furthermore, the vacuum cleaner can have a control device, wherein the control device is preferably configured to evaluate the negative pressure data determined by the sensors and, based on the determined negative pressure data, to set whether the vacuum cleaner operates in series or parallel operation.According to the invention, it is preferred that the turbines of the vacuum cleaner are sequentially flowed through in series operation, while the turbines of the vacuum cleaner are preferably flowed through in parallel operation by partial suction flows of the suction flow. Due to the different operating modes "series operation" and "parallel operation" of the vacuum cleaner, the proposed vacuum cleaner is advantageously capable of covering a particularly wide range of different suction power levels. This allows the vacuum cleaner and its operation to be optimally adapted to different applications, so that, for example, the energy consumption of the vacuum cleaner can be minimized. This is particularly advantageous when the vacuum cleaner is battery-operated, since in this case the range of the battery(ies) can be significantly increased or extended using the invention.

[0016] It is preferred within the meaning of the invention that a first negative pressure range and / or a first flow velocity range can be assigned to the series operation of the vacuum cleaner, while a second negative pressure range and / or a second flow velocity range are assigned to the parallel operation of the vacuum cleaner. This preferably means within the meaning of the invention that the vacuum cleaner can achieve different ranges of negative pressure values ​​and flow velocities in its different operating modes - series operation and parallel operation. It may be preferred within the meaning of the invention that these negative pressure ranges and / or flow velocity ranges are designed to be disjoint from one another and do not overlap. However, it may also be preferred within the meaning of the invention that the suppression and flow velocity ranges overlap.According to the invention, it is preferred that the operating parameters "flow velocity" and "negative pressure" be plotted in a diagram, with the flow velocity preferably being plotted on the y-axis and the negative pressure on the x-axis. This flow velocity versus negative pressure plot can preferably be referred to as a "suction curve" according to the invention.

[0017] According to the invention, it is preferred that series operation of the vacuum cleaner is characterized in that a comparatively low flow velocity and a high negative pressure are achieved in the vacuum cleaner, while parallel operation of the vacuum cleaner results in comparatively high flow velocity and low negative pressure values. It has been shown that by combining the different operating modes in a vacuum cleaner, the flow velocities and the achievable negative pressure values ​​can be almost doubled. The flow velocities and negative pressure values ​​achievable by combining the different operating modes in a vacuum cleaner can advantageously be represented in a combined suction curve, which essentially combines the best properties of the individual series operation and the individual parallel operation of two turbines.As a result, the invention can provide a vacuum cleaner with an optimized suction curve, which is characterized in particular by particularly high achievable flow velocities and negative pressure values.

[0018] The same applies mutatis mutandis to the volume flow Q of the suction flow S. Within the meaning of the invention, it is preferred that a first negative pressure range and / or a first volume flow range can be assigned to the series operation of the vacuum cleaner, while a second negative pressure range and / or a second volume flow range are assigned to the parallel operation of the vacuum cleaner. Within the meaning of the invention, this preferably means that the vacuum cleaner can achieve different ranges of negative pressure values ​​and volume flows in its different operating modes - series operation and parallel operation. Within the meaning of the invention, it may be preferred that these negative pressure ranges and / or volume flow ranges are designed to be disjoint from one another and do not overlap. However, it may also be preferred within the meaning of the invention that the negative pressure and volume flow ranges overlap.According to the invention, it is preferred that the operating parameters "volume flow" and "negative pressure" be plotted in a diagram, with the volume flow Q preferably being plotted on the y-axis and the negative pressure on the x-axis. This volume flow versus negative pressure plot can preferably also be referred to as a "suction curve" according to the invention.

[0019] According to the invention, it is preferred that series operation of the vacuum cleaner is characterized in that a comparatively low volume flow Q and a high negative pressure are achieved in the vacuum cleaner, while parallel operation of the vacuum cleaner results in comparatively high volume flows and low negative pressure values. It has been shown that by combining the different operating modes in a vacuum cleaner, the volume flows and the achievable negative pressure values ​​can be almost doubled. The volume flows and negative pressure values ​​achievable by combining the different operating modes in a vacuum cleaner can advantageously be represented in a combined suction curve, which essentially combines the best properties of the individual series operation and the individual parallel operation of two turbines.As a result, the invention makes it possible to provide a vacuum cleaner with an optimized suction curve, which is characterized in particular by particularly high achievable volume flows and negative pressure values.

[0020] According to the invention, it is preferred that the turbines of the vacuum cleaner be comparatively small and have a comparatively low suction power. For example, the turbines can have approximately half the nominal power typically found in vacuum cleaners. The use of two comparatively small turbines, which can preferably be operated in a variable parallel or series connection, has the advantage that, in particular, those operating ranges characterized by a high or maximum volume flow and / or a high or maximum vacuum can be expanded or better served. These operating ranges are frequently used in vacuum cleaners.To ensure optimal operation of the vacuum cleaner with good suction power in these working areas, a very large, virtually oversized turbine would have to be used if only one turbine were used, which would require a lot of space. It has been shown that the use of two comparatively small turbines does not simply replace one large turbine, but rather offers the surprising advantages mentioned above, which experts had not anticipated. In particular, the use of the two comparatively small turbines can ensure improved operation in frequently used working areas characterized by high volume flow and / or strong vacuum.

[0021] In accordance with the invention, it is preferred that essentially identical turbines be used within the proposed vacuum cleaner, thus realizing manufacturing and procurement advantages. However, it may also be preferred that different turbines be used to expand the suction curve.

[0022] The feature that the valve arrangement can allow the suction flow to flow through the turbines one after the other or in parallel to one another preferably means, within the meaning of the invention, that the suction flow practically always flows through the first turbine, i.e. during operation of the vacuum cleaner and when no filter cleaning is taking place. When the vacuum cleaner is running in series operation, it is preferred within the meaning of the invention that the suction flow flows through the first turbine and the second turbine one after the other. In this embodiment of the invention, the suction flow can first flow through the first turbine and then through the second turbine, wherein this sequential flow through the first and second turbines is preferably referred to as "series operation" of the vacuum cleaner within the meaning of the invention. The term "series operation" within the meaning of the invention preferably means that the turbines are connected "in series" or "in series" and are successively flowed through by the suction flow.Alternatively, the turbines can also be connected in parallel and the suction flow can flow through them in parallel. In this embodiment of the invention, it is preferred that the suction flow is divided into partial suction flows, with a first partial suction flow flowing through the first turbine and a second partial suction flow flowing through the second turbine. The strength, extent, and / or volume of the partial suction flows preferably depend on whether identical or different turbines are used. The aforementioned properties of the partial suction flows can also depend on whether the valves of the valve arrangement are fully or only partially open.

[0023] The valve arrangement can, for example, comprise flap, slide, or rotary valves. It is preferred within the meaning of the invention that the valve arrangement comprises different types of valves, such as flap and rotary valves. However, it may also be preferred for the valve arrangement to comprise exclusively flap valves, exclusively slide valves, or exclusively rotary valves. Various possible and preferred embodiments of the valve arrangement are described below:

[0024] Example of «Series operation of the vacuum cleaner with flap valves»

[0025] During serial operation of the vacuum cleaner with flap valves, it is preferred according to the invention that the valve arrangement comprises flap valves and that the suction flow flows through the turbines of the vacuum cleaner one after the other. For example, the vacuum cleaner or its valve arrangement can have two flap valves, which are referred to as first and second flap valves according to the invention. Flap valves are preferably designed according to the invention to open or close a line for a - possibly dust-laden - air flow. This function of a flap valve can be used primarily when the flap valve is arranged in a continuous line that is to be able to be opened or closed. For example, in the exemplary embodiment "serial operation of the vacuum cleaner with flap valves", the second flap valve can be arranged in the second suction section between the filter unit and the second turbine.The second flap valve can thus be configured to open or close the second suction section between the filter unit and the second turbine. In the exemplary embodiment of the invention "serial operation of the vacuum cleaner with flap valves", it is preferred within the meaning of the invention for the second flap valve to be closed and to close the second suction section. As a result, advantageously no air flows from the dust collection container of the vacuum cleaner towards the second turbine, but rather the direct path between the dust collection container and the second turbine is closed by the second flap valve of the valve arrangement. The direct path between the dust collection container and the second turbine is preferably referred to as the second suction section within the meaning of the invention.Instead, the preferably dust-laden suction stream flows from the dust container through the vacuum cleaner's filter unit, where the suction stream is filtered, so that after passing through the filter unit, the suction stream is at least somewhat purified and contains significantly less dust and particles than before filtering. The preferably purified suction stream then flows through the first suction section, which is preferably arranged between the filter unit and the first turbine, toward the first turbine. The suction stream flows through the first turbine and then reaches the area of ​​the first flap valve of the vacuum cleaner's valve assembly.The first flap valve is preferably arranged at a T-junction, whereby the suction flow can flow through a line towards the T-bar and then branch into two possible lines, whereby both possible lines are opened or closed by the first flap valve. On the one hand, the suction flow, which in the exemplary embodiment "series operation of the vacuum cleaner with flap valves" comes from the first turbine, can flow towards the first output section and towards the first inlet and outlet opening of the vacuum cleaner. However, in the exemplary embodiment "series operation of the vacuum cleaner with flap valves" this path is preferably closed off, namely by the first flap valve. Instead, in the exemplary embodiment of the invention "series operation of the vacuum cleaner with flap valves" it is preferred that the suction flow coming from the first turbine flows at the T-junction through the suction channel towards the second turbine.Thus, in the exemplary embodiment "serial operation of the vacuum cleaner with flap valves", the first flap valve is set such that the first flap valve opens the suction channel, which is arranged between the first and second turbines, for the suction flow. The suction flow then preferably flows through the second turbine, flows into the second outlet section and leaves the vacuum cleaner through the second inlet and outlet opening. Thus, within the meaning of the invention, it is preferred that in the exemplary embodiment "serial operation of the vacuum cleaner with flap valves", the first flap valve is set such that the suction flow can flow from the first turbine through the suction channel towards the second turbine, while the second flap valve is set such that the second suction section between the dust collection container or the filter unit and the second turbine is closed.Thus, in the embodiment of the invention “serial operation of the vacuum cleaner with flap valves”, the suction flow flows successively through the first turbine and then through the second turbine.

[0026] It is preferred in the sense of the invention that in the embodiment "serial operation of the vacuum cleaner with flap valves" both the first and the second turbine are flowed through by the suction flow, wherein the suction flow flows successively through the first turbine and then through the second turbine.

[0027] Example of «Parallel operation of the vacuum cleaner with flap valves»

[0028] In the exemplary embodiment "parallel operation of the vacuum cleaner with flap valves," the valve arrangement also has two flap valves, with the first flap valve and the second flap valve being arranged in essentially the same positions as in the exemplary embodiment "serial operation of the vacuum cleaner with flap valves." Within the meaning of the invention, this preferably means that the first flap valve is arranged at the T-junction between the first turbine on one side and the lines to the first inlet and outlet opening or the second turbine on the other side. The second flap valve is preferably arranged in the second suction section between the dust collection container or the filter unit and the second turbine.In the embodiment "parallel operation of the vacuum cleaner with flap valves," the first flap valve is preferably set such that the path from the first turbine through the first output section and the first inlet and outlet opening is cleared. In other words, the suction flow coming from the first turbine can flow through the first output section and leave the vacuum cleaner through the first inlet and outlet opening. The second flap valve is preferably set such that the second suction section between the dust collection container or the filter unit on one side and the second turbine is cleared, so that the suction flow from the dust collection container can flow at least partially through the second turbine.According to the invention, the suction flow in the embodiment "parallel operation of the vacuum cleaner with flap valves" is preferably divided into two partial suction flows, with the first partial suction flow flowing through the first turbine and the second partial suction flow flowing through the second turbine. The first partial suction flow exits the vacuum cleaner through the first inlet and outlet opening, while the second partial suction flow exits the vacuum cleaner through the second inlet and outlet opening.Thus, in the sense of the invention, it is preferred that in the exemplary embodiment "parallel operation of the vacuum cleaner with flap valves", the first flap valve is set such that a first partial suction flow flows from the first turbine through the first output section towards the first inlet and outlet opening, while the second flap valve is set such that a second partial suction flow flows from the dust collection container through the filter unit through the second suction section towards the second turbine, to then continue through the second output section and exit the vacuum cleaner through the second inlet or outlet opening. Thus, in the exemplary embodiment of the invention "parallel operation of the vacuum cleaner with flap valves", the suction flow is divided into a first and a second partial suction flow, wherein the partial suction flows flow through the turbines of the vacuum cleaner parallel to one another.According to the invention, it is preferred that the first partial suction flow flows through the first turbine and leaves the vacuum cleaner through the first inlet or outlet opening, while the second partial suction flow flows through the second turbine and leaves the vacuum cleaner through the second inlet or outlet opening. The partial suction flows are preferably guided through the vacuum cleaner by the valve arrangement in the manner described above, wherein the valve arrangement in the exemplary embodiment "parallel operation of the vacuum cleaner with flap valves" preferably comprises two flap valves, i.e. a first and a second flap valve. According to the invention, in the exemplary embodiment "parallel operation of the vacuum cleaner with flap valves" the suction flow or a partial suction flow flows through both the first and the second turbine, wherein the first turbine is flowed through by a first partial suction flow and the second turbine is flowed through by a second partial suction flow.Preferably, in the embodiment “parallel operation of the vacuum cleaner with flap valves”, the turbines of the vacuum cleaner are flowed through by partial suction flows parallel to each other.

[0029] According to the invention, it is preferred that the valve arrangement comprises at least a first flap valve and a second flap valve, the first flap valve being arranged downstream of the first turbine in a suction flow direction, and the second flap valve being arranged upstream of the second turbine in a suction flow direction. The first flap valve can preferably be arranged in the region of the T-junction between the first turbine on the one side and the first output section and the first inlet or outlet opening or the suction channel and the second turbine on the other side. According to the invention, it is preferred that the first flap valve allows the suction flow to flow either in the direction of the first inlet or outlet opening or in the direction of the second turbine, while the second flap valve enables or prevents the suction flow from flowing through the second turbine.The second flap valve is particularly designed to open or close the second suction section between the dust collection container or the filter unit on the one side and the second turbine on the other side.

[0030] Of course, slide valves can also be used instead of flap valves.

[0031] Example of «Series operation of the vacuum cleaner with rotary valves»

[0032] In the exemplary embodiment of the invention in which the valve arrangement has rotary valves, the valve arrangement preferably has three rotary valves, the first rotary valve being located between the first turbine and the second turbine and the second rotary valve being located between the second turbine and the filter unit. In the sense of the invention, it is preferred that the first rotary valve is designed to close or open a suction channel between the first turbine and the second turbine, and the second rotary valve is designed to close or open a second suction section between the second turbine and the filter unit. In the exemplary embodiment “serial operation of the vacuum cleaner with rotary valves”, the first rotary valve is preferably set so that the suction channel between the first turbine and the second turbine is opened.This allows the preferably undivided suction flow from the first turbine through the suction channel toward the second turbine. The second rotary valve is preferably located in the second suction section, with the second rotary valve in the "series operation of the vacuum cleaner with rotary valves" embodiment being set such that the second rotary valve closes the second suction section. This prevents air from flowing from the dust collection container or from the filter unit toward the second turbine. As a result, the suction flow advantageously flows undivided from the dust collection container through the filter unit and through the first suction section toward the first turbine of the vacuum cleaner.

[0033] It is preferred according to the invention that the valve arrangement in the embodiment of the invention in which the valve arrangement has rotary valves comprises a third rotary valve, wherein the third rotary valve is arranged between the first turbine and the first inlet or outlet opening. Preferably, the third rotary valve can be configured to close or open an outlet section between the first turbine and the first inlet or outlet opening. In the embodiment "serial operation of the vacuum cleaner with rotary valves", the third rotary valve is preferably set such that the third rotary valve closes the first outlet section, so that no air flow can flow from the first turbine towards the first inlet and outlet opening. Instead, the suction flow preferably leaves the vacuum cleaner through the second inlet or outlet opening after the suction flow has flowed through the second turbine.Thus, in the exemplary embodiment "serial operation of the vacuum cleaner with rotary valves", it is preferred that the first rotary valve of the valve arrangement is open and releases the suction channel between the first and second turbines, while the second and third rotary valves of the valve arrangement are closed and seal off their corresponding line sections - second suction section and first outlet section. In particular, in the exemplary embodiment "serial operation of the vacuum cleaner with rotary valves", the turbines of the vacuum cleaner are flowed through in series, i.e. one after the other, i.e. the suction flow flows first through the first turbine and then through the second turbine. The preferably undivided suction flow is guided accordingly through the vacuum cleaner by the valve arrangement or its rotary valves.

[0034] Example of «Parallel operation of the vacuum cleaner with rotary valves»

[0035] In the embodiment "parallel operation of the vacuum cleaner with rotary valves," it is preferred that the first rotary valve of the valve arrangement is closed and closes the suction channel between the first and second turbines, while the second and third rotary valves of the valve arrangement are open and release their corresponding line sections—second suction section and first outlet section. By opening the second rotary valve, which is preferably arranged in the second suction section between the dust collection container or the filter unit and the second turbine, the suction flow can be divided so that a first partial suction flow from the dust collection container flows through the first turbine, while a second partial suction flow from the dust collection container flows through the second turbine.After the first partial suction flow has flowed through the first turbine, the first partial suction flow flows into the first outlet section and exits the vacuum cleaner through the first inlet or outlet opening. In the embodiment "parallel operation of the vacuum cleaner with rotary valves," the first outlet section is preferably released by the third rotary valve. The second partial suction flow flows from the dust collection container through the filter unit and the second suction section toward the second turbine and further through the second outlet section, so that the second partial suction flow can exit the vacuum cleaner through the second inlet or outlet opening.

[0036] It is preferred in the sense of the invention that the function of the first flap valve in the design of the valve arrangement with rotary valves is taken over by the first and third rotary valve, while the function of the second flap valve essentially corresponds to the function of the second rotary valve.

[0037] According to the invention, it is preferred that the vacuum cleaner comprises a dust collection container for collecting dust. The dust collection container can preferably be located in a lower region of the vacuum cleaner and collects the dust and particles generated during operation of a machine tool. The filter unit of the vacuum cleaner can be arranged above the dust collection container, so that dust filtered from the suction stream by the filter unit, as well as filter cake removed from the filter during filter cleaning, can fall into the dust collection container.

[0038] According to the invention, it is preferred that the first turbine is assigned a first inlet or outlet opening and the second turbine is assigned a second inlet or outlet opening. The suction flow can preferably leave the vacuum cleaner through the first inlet or outlet opening and / or the second inlet or outlet opening. In this case, the preferably undivided suction flow can leave the vacuum cleaner in series operation through the second inlet or outlet opening, while the partial suction flows that arise when the air flows through the turbines of the vacuum cleaner in parallel leave the vacuum cleaner through the first inlet or outlet opening and the second inlet or outlet opening. According to the invention, it is preferred that the first outlet section is arranged between the first turbine and the first inlet or outlet opening, while the second outlet section is arranged between the second turbine and the second inlet or outlet opening.It is preferred in the sense of the invention that the first turbine and the first inlet or outlet opening are connected to one another via a first output section and the second turbine and the second inlet or outlet opening are connected to one another via a second output section.

[0039] According to the invention, it is preferred that the valve arrangement is configured to allow a cleaning stream to flow through the first turbine and / or the second turbine in a direction opposite to the suction stream. The filter unit of the vacuum cleaner can be cleaned with the cleaning stream, which preferably flows in a direction opposite to the direction of the suction stream. This ensures optimal, efficient suction operation of the vacuum cleaner over the entire service life of the vacuum cleaner. The vacuum cleaner can be operated in suction mode, in which the suction stream can flow through both turbines of the vacuum cleaner (parallel operation), or in which the suction stream can flow through one of the two turbines of the vacuum cleaner (series operation). In addition, the vacuum cleaner can be operated in a cleaning mode, in which the filter unit, preferably one of the two filter sections of the filter unit, is cleaned.

[0040] According to the invention, it is preferred that the vacuum cleaner comprises a filter unit for filtering the suction flow, wherein, during cleaning of the filter unit of the vacuum cleaner, one turbine maintains the suction operation of the vacuum cleaner, while the other turbine is flowed through by a cleaning flow. A flow direction of the cleaning flow is preferably opposite to a flow direction of the suction flow. The suction flow of the vacuum cleaner can preferably extend from a suction hose inlet through the dust collection container, through the filter unit, through one or both suction channels, and through one or both of the turbines, wherein the suction flow leaves the vacuum cleaner through one or both of the inlet or outlet openings of the vacuum cleaner.In other words, the suction flow can enter the vacuum cleaner in the area of ​​the suction hose inlet and flow through the dust collection container, the filter unit, one or both suction channels and through one or both of the turbines and leave the vacuum cleaner through one or both of the inlet or outlet openings of the vacuum cleaner. The cleaning flow preferably flows in a flow direction that is opposite to the flow direction of the suction flow. The cleaning flow can also be referred to as a backwash flow, since the cleaning flow flows through the turbines and / or the filter units of the vacuum cleaner in the opposite direction of the suction flow. The cleaning flow can preferably be brought about by opening at least one of the inlet or outlet openings of the vacuum cleaner.This can be achieved, for example, by the valve arrangement opening at least one of the outlet sections so that ambient air can be sucked into the vacuum cleaner through the corresponding inlet or outlet opening. This suction process for generating the cleaning flow preferably occurs suddenly, with the cleaning flow being caused in particular by the negative pressure prevailing in the vacuum cleaner. If the valve arrangement is switched in such a way that at least one of the inlet or outlet openings is opened, a flow is created to compensate for the pressure difference between the environment and the interior of the vacuum cleaner, with this pressure-compensating flow preferably forming the cleaning flow within the meaning of the invention.Preferably, the cleaning stream flows from the inlet or outlet opening through the first or second outlet section, through the first or second turbine, through the first or second suction channel, and toward the filter unit. There, the cleaning stream backwashes or flushes the filter unit, whereby this backwash or flushing can loosen any filter cake adhering to the filter unit. Backwashing or flushing the filter unit can advantageously clean the filter, and the removed filter cake can fall into the vacuum cleaner's dust container for later disposal.

[0041] The invention can now generate a cleaning stream that can flow through the first turbine or the second turbine when cleaning the filter unit, preferably in the opposite direction to the suction stream flowing through the turbines when the vacuum cleaner is in suction mode. According to the invention, the cleaning stream is preferably caused by the pressure difference between the interior of the vacuum cleaner and its surroundings. Preferably, a flow is formed that tends to equalize this pressure difference, with this pressure-equalizing flow preferably forming the cleaning stream with which the filter unit or its filter sections can be backwashed or rinsed and thus cleaned.

[0042] The cleaning flow can be brought about in particular by a clever switching or positioning of the valve arrangement. According to the invention, it is preferred that the filter unit has a first filter section and a second filter section, wherein a first cleaning area is assigned to the first filter section and a second cleaning area is assigned to the second filter section. Preferably, the cleaning flow can flow through the first turbine when cleaning the first filter section, while the cleaning flow flows through the first turbine when cleaning the second filter section. When cleaning the first filter section, it is preferred according to the invention that the cleaning flow flows through the first turbine of the vacuum cleaner, while the suction flow in this case flows through the second turbine, so that the suction operation can be maintained by the suction flow through the second turbine.Similarly, when cleaning the second filter section, the cleaning stream can flow through the vacuum cleaner's second turbine, while the suction stream in this case flows through the first turbine, so that the suction operation is maintained by the suction stream through the first turbine. In this way, the invention enables continued suction operation of the vacuum cleaner while simultaneously cleaning the filter unit or part of the filter unit.

[0043] According to the invention, it is preferred that the cleaning areas be fluidically separated from one another, so that, in particular, no fluid exchange or pressure equalization can occur between the cleaning areas. The cleaning areas preferably represent the spaces above or above the clean side of the filter unit, i.e., the sides of the filter that spatially face the turbines and not the dust collection container.

[0044] According to the invention, it is preferred that the valve arrangement comprises a fourth rotary valve, wherein the fourth rotary valve is arranged between the first turbine and the filter unit and is configured to close or open a first suction section between the first turbine and the filter unit. If the valve arrangement of the vacuum cleaner comprises, for example, four rotary valves, the first rotary valve, which is preferably arranged in the suction channel between the first and second turbines, can be closed to enable cleaning of the first filter section. This prevents serial operation of the turbines of the vacuum cleaner and the suction flow cannot flow through the two turbines of the vacuum cleaner one after the other. To enable cleaning of the first filter section, the second, third and fourth rotary valves can be opened.By opening the second rotary valve, which is preferably located in the second suction section between the filter unit and the second turbine, a partial suction flow from the vacuum cleaner's dust container can flow through the second suction section toward the second turbine, thus maintaining suction operation through the second turbine. The suction flow can then flow through the second outlet section and exit the vacuum cleaner through the second inlet or outlet opening. By opening the third rotary valve, which is preferably located in the first outlet section, the first outlet section can be released and the first inlet or outlet opening can be opened.This allows ambient air to be sucked into the vacuum cleaner, whereby this suction of ambient air is caused in particular by the pressure difference that exists between the vacuum-pressurized interior of the vacuum cleaner and the environment of the vacuum cleaner which is subjected to normal or atmospheric pressure.

[0045] The ambient air can be sucked in particularly suddenly, with the suction process becoming more sudden the greater the pressure difference between the interior and the surroundings of the vacuum cleaner. The sucked in ambient air forms the cleaning stream, which in the exemplary embodiment described here, in which the first filter section is cleaned and the suction operation is maintained by the second turbine, flows from the first inlet or outlet opening through the first turbine in the direction of the first filter section. There, the cleaning stream flows through the first filter section against the flow direction of the suction stream, so that within the meaning of the invention, this is preferably referred to as a through-flushing or backflushing of the first filter section. The cleaning stream reaches the filter unit - coming from the first turbine - in particular because the fourth rotary valve is open.By opening the fourth rotary valve of the valve assembly of the vacuum cleaner, the first suction section can be released so that the cleaning stream can flow from the first turbine towards the filter unit.

[0046] Analogous to the description above, in a second filter cleaning mode the second filter section can be cleaned and the suction operation can be maintained by the first turbine. In this second filter cleaning mode too, the first rotary valve is preferably closed, while the second, third and fourth rotary valves are open. In the second filter cleaning mode, ambient air flows into the vacuum cleaner through the second inlet or outlet opening, with this inflowing ambient air forming the cleaning stream for the second turbine. This cleaning stream flows through the second turbine towards the filter unit, in particular towards the second filter section of the filter unit. The cleaning stream can reach the filter unit and rinse the second filter section and thereby clean it, because the second rotary valve is open in the second filter cleaning mode.The vacuum cleaner's suction operation is maintained by the first turbine, with the suction flow entering the vacuum cleaner through the suction hose inlet into the vacuum cleaner's dust container and passing through the filter unit, the open fourth rotary valve, and the first suction section to the first turbine. From there, the suction flow continues toward the first inlet or outlet opening, passing through the third rotary valve and the first outlet section.

[0047] According to the invention, it is preferred that, when the first filter section of the filter unit is being cleaned, the vacuum cleaner's suction operation can be maintained by continuing to direct the suction flow through the second turbine. When the second filter section is being cleaned and the cleaning flow is flowing through the second turbine, the vacuum cleaner's suction operation can be maintained by continuing to direct the suction flow through the first turbine. This allows each turbine to ensure suction operation while the filter section associated with the other turbine and the other cleaning area can be cleaned.

[0048] If the filter unit consists of two filter sections, each assigned to the first turbine and the second turbine, the strength, extent, and / or volume of the partial suction flows can preferably also depend on how free or clogged the filter sections are. For example, if a first filter section assigned to the first turbine is freshly cleaned and relatively new, a strong and large partial suction flow can flow through the first filter section, while a clogged or old filter section can only allow a weaker or smaller partial suction flow to pass through. The filter unit can have a second filter section, which can be assigned to the second turbine.The filter sections can, for example, be formed in that the filter unit comprises a first filter, which can be referred to as the first filter section, and wherein the filter unit comprises a second filter, which can be referred to as the second filter section. Alternatively, the filter unit can also comprise a single filter which comprises independent filter sections. It is preferred within the meaning of the invention that, when a first and a second filter section are provided, the filter sections can each be assigned to a cleaning area. Preferably, the first filter section of the filter unit can be assigned to a first cleaning area, while the second filter section of the filter unit can be assigned to a second cleaning area.

[0049] In a second aspect, the invention relates to a method for operating the proposed vacuum cleaner, the method comprising the following method steps: a) providing a vacuum cleaner with a first turbine and a second turbine, b) controlling a valve arrangement of the vacuum cleaner so that a suction flow flows through the turbines either sequentially or in parallel.

[0050] The terms, definitions, and technical advantages introduced for the vacuum cleaner preferably apply analogously to the operating method. The proposed method can preferably comprise determining and / or evaluating operating data of the vacuum cleaner, wherein the control of the valve arrangement of the vacuum cleaner takes place as a function of the previously determined operating data. In the sense of the invention, it is preferred that a vacuum cleaner is provided with two comparatively small turbines, wherein the turbines can be essentially the same or different. During operation of the vacuum cleaner, operating data and / or operating parameters can be determined by a suitable sensor system of the vacuum cleaner. The vacuum cleaner can comprise a control device with which the operating data and / or operating parameters determined by the sensor system can be evaluated.The determined and / or evaluated operating data and / or operating parameters can preferably be used to control the vacuum cleaner or its valve arrangement such that a specific operating mode is set. The operating modes of the vacuum cleaner can in particular be series and parallel operation of the turbines of the vacuum cleaner. In series operation of the vacuum cleaner, the suction flow can flow as a substantially undivided suction flow one after the other through the first turbine and the second turbine. In parallel operation of the vacuum cleaner, it is preferred that the suction flow is divided and a partial suction flow flows through the first turbine and the second turbine. According to the invention, it is preferred that in parallel operation, a first partial suction flow flows through the first turbine, while a second partial suction flow flows through the second turbine.

[0051] Further advantages emerge from the following description of the figures. The figures, the description, and the claims contain numerous features in combination. The skilled person will also expediently consider the features individually and combine them into further meaningful combinations.

[0052] In the figures, identical and similar components are numbered with the same reference numerals. They show:

[0053] Fig. 1 View of a preferred embodiment of the vacuum cleaner with two turbines and a valve arrangement

[0054] Fig. 2 View of a preferred embodiment of the vacuum cleaner in series operation with rotary valves

[0055] Fig. 3 View of a preferred embodiment of the vacuum cleaner in series operation with flap valves

[0056] Fig. 4 View of a preferred embodiment of the vacuum cleaner in parallel operation with rotary valves

[0057] Fig. 5 View of a preferred embodiment of the vacuum cleaner in parallel operation with flap valves

[0058] Fig. 6 View of a preferred embodiment of the combined suction curve

[0059] Fig. 7 further view of a preferred embodiment of the combined suction curve

[0060] Fig. 8 View of a preferred embodiment of the vacuum cleaner with filter cleaning function

[0061] Fig. 9 View of a preferred embodiment of the vacuum cleaner with filter cleaning function and backwashing through the first turbine

[0062] Fig. 10 View of a preferred embodiment of the vacuum cleaner with filter cleaning function and backwashing by the second turbine

[0063] Fig. 11 View of an alternative preferred embodiment of the vacuum cleaner with filter cleaning function

[0064] Fig. 12 View of an alternative preferred embodiment of the vacuum cleaner with filter cleaning function and backwashing through the first turbine Fig. 13 View of an alternative preferred embodiment of the vacuum cleaner with filter cleaning function and backwashing through the second turbine

[0065] Implementation examples and figure descriptions:

[0066] Figure 1 shows a preferred embodiment of the vacuum cleaner 10 with a first turbine T1 and a second turbine T2, as well as a valve arrangement V. The vacuum cleaner 10 comprises, in a lower region, a dust collection container 12 into which a suction hose inlet 14 can open. For example, a suction hose (not shown) can be connected to the suction hose inlet 14 in order to connect the vacuum cleaner 10 to a machine tool (not shown) or a floor nozzle (not shown). A filter unit F, through which the air flow is drawn through the vacuum cleaner 10, can be arranged above the dust collection container 12.The air flow through the vacuum cleaner 10 can be generated by the two turbines T1, T2, wherein the air flow which enters the vacuum cleaner 10 as a preferably dust-laden air flow eLS through the suction hose inlet 14 and is sucked in the direction of the first turbine T1 and the second turbine T2 is preferably referred to as suction flow S. The suction flow S can be cleaned when passing through the filter unit F. In the context of the present invention, the suction flow S can either flow essentially undivided one after the other through the two turbines T1, T2 of the vacuum cleaner 10 (single operation SM, see Figs. 2 and 3) or can be split into a first partial suction flow TS1 and a second partial suction flow TS2 and flow in parallel through the turbines T1, T2 (parallel operation PM, see Figs. 4 and 5).

[0067] The suction flow S is guided through the interior of the vacuum cleaner 10 by means of a valve arrangement V. The valve arrangement V can comprise flap valves KV and / or rotary valves DV, whereby both those valve arrangements V which have only flap valves KV or only rotary valves DV can be preferred, as can those valve arrangements V which have both flap valves KV and rotary valves DV. Figures 1 and 2 show, by way of example, a valve arrangement V which comprises rotary valves DV. In Figure 1, the different positions of the rotary valves DV and the rotatability of the rotary valves DV are indicated by the curved double arrows.

[0068] The regions which adjoin the filter unit F in the direction of the suction flow S are preferably referred to as the first suction section SA1 and the second suction section SA2. The first suction section SA1 is preferably arranged between the filter unit F and the first turbine T1, whilst the second suction section SA2 is preferably arranged between the filter unit F and the second turbine T2. The region between the turbines T1, T2 is preferably referred to as the suction channel SK in the sense of the invention. In the direction of the suction flow S, the turbines T1, T2 are adjoined by line sections which are referred to as the first outlet section AA1 and the second outlet section AA2.The first output section AA1 is preferably located between the first turbine T1 and a first inlet or outlet opening O1, while the second output section AA2 is preferably arranged between the second turbine T2 and a second inlet or outlet opening O2. Through the inlet or outlet openings O1, O2, the suction flow S can leave the vacuum cleaner 10 as an outgoing air flow aLS.

[0069] 1, the rotary valves DV of the valve arrangement V are arranged in the suction channel SK, in the second suction section SA2 and in the first outlet section AA1. The first rotary valve DV1 is arranged behind the first turbine T1 and in front of the second turbine T2 in the direction of the suction flow S when the turbines T1, T2 are successively flowed through by the suction flow S, and thus in the suction channel SK. The first rotary valve DV1 is preferably designed to open or close the suction channel SK. The rotary valve DV1 can therefore determine whether the suction flow S, after flowing through the first turbine T1, flows further in the direction of the second turbine T2 (serial operation SM of the vacuum cleaner 10) or in the direction of the first inlet or outlet opening O1, where the suction flow S can leave the vacuum cleaner 10 as an outgoing air flow aLS.The second rotary valve DV2 is preferably located in the direction of the suction flow S between the filter unit F and the second turbine T2, thus in the second suction section SA2. The second rotary valve DV2 can thus determine whether a portion of the suction flow S flows from the dust collection container 12 in the direction of the second turbine T2 (parallel operation PM of the vacuum cleaner 10) or whether the suction flow S flows essentially undivided through the first suction section SA1 in the direction of the first turbine T1. The portion of the suction flow S that flows through the second turbine T2 is preferably referred to as the second partial suction flow TS2 within the meaning of the invention, while the other portion of the suction flow S that flows through the first turbine T1 is preferably referred to as the first partial suction flow TS1 within the meaning of the invention.The third rotary valve DV3 is located in the direction of the suction flow S behind the first turbine T1, but in the first suction section SA1, preferably between the first turbine T1 and the first inlet or outlet opening O1. The third rotary valve DV3 thus determines whether the first inlet or outlet opening O1 is open or closed. In other words, the third rotary valve DV3 is designed to open or close the first outlet section AA1 or the first inlet or outlet opening O1. When open, the suction flow S can completely or partially leave the vacuum cleaner 10 through the first inlet or outlet opening O1 as an outgoing air flow aLS. In the direction of the suction flow S behind the second turbine T2 is the second outlet section AA2, which forms the line section between the second turbine T2 and the second inlet or outlet opening O2.When the vacuum cleaner 10 is operated in parallel mode PM, a part of the suction flow S, in particular the second partial suction flow TS2, can leave the vacuum cleaner 10 through the second inlet or outlet opening 02 as outgoing air flow aLS.

[0070] Figure 2 shows a preferred embodiment of the vacuum cleaner 10 in series operation SM with a valve arrangement V which comprises three rotary valves DV. The positions and functions of the three rotary valves DV were described in the previous section. In series operation SM of the vacuum cleaner 10, the suction flow S flows essentially undivided one after the other through the first turbine T1 and through the second turbine T2. The flow of the suction flow S is indicated in Figure 2 by dashed arrows. To enable series operation SM of the vacuum cleaner 10, the first rotary valve DV1 in the suction channel SK between the turbines T1, T2 is open, while the second rotary valve DV2 and the third rotary valve DV3 are closed. After passing through the first turbine T1, the suction flow S flows through the suction channel SK opened by the first rotary valve DV1 in the direction of the second turbine T2.After passing through the second turbine T2, the suction flow S flows further through the second outlet section AA2 and leaves the vacuum cleaner 10 as outgoing air flow aLS through the second inlet or outlet opening O2. If the valve arrangement V - as shown in Figure 2 - is formed by three rotary valves DV, in series operation SM of the vacuum cleaner 10 the first outlet section AA1 and the second suction section SA2 are closed because the second rotary valve DV2 and the third rotary valve DV3 are closed.

[0071] A suction curve is shown in the lower part of Figure 2. For a suction curve, the volume flow Q of the suction flow S can be shown on the y-axis and the negative pressure -p on the x-axis. The volume flow Q of the suction flow S can, for example, be shown in the unit meter. 3 / second (m 3 / s), while the negative pressure -p can be specified in the unit millibar (mbar). Although the negative pressure has a negative sign, the negative pressure is plotted along the positive x-axis in the suction curve shown in Figure 2; thus, the amount of the negative pressure -p is shown. The suction curve in Figure 2 shows, in particular, the volume flow Q versus the negative pressure -p when only the first turbine T1 of the vacuum cleaner 10 is used ("T1"). In addition, it shows how the volume flow Q behaves as a function of the negative pressure -p when the suction flow S flows through the first turbine T1 and the second turbine T2 one after the other in series operation SM (or: "in series") ("T(1+2)_S"). It can be seen that significantly higher negative pressure values ​​can be achieved when two turbines T1, T2 are used, i.e.when a vacuum cleaner 10 has two turbines T1, T2, through which a suction flow S flows one after the other.

[0072] Figure 3 shows a preferred embodiment of the vacuum cleaner 10 in series operation SM with a valve arrangement V comprising two flap valves KV. The first flap valve KV1 can be arranged and / or adjusted such that the first flap valve KV1 is arranged behind the first turbine T1 in the direction of the suction flow S. The first flap valve KV1 can either open the suction channel SK in the direction of the second turbine T2 or the first outlet section AA1 in the direction of the first inlet or outlet opening O1. The second flap valve KV2 is arranged in the second suction section SA2 between the filter unit F and the second turbine T2 such that it can open or close the second suction section SA2. In the series operation SM of the vacuum cleaner 10 with flap valves KV shown in Figure 3, the first flap valve KV1 is adjusted such that the suction flow S can flow from the first turbine T1 through the suction channel SK in the direction of the second turbine T2.The second flap valve KV2, on the other hand, is closed, so that no air flow can flow from the dust collection container 12 through the second suction section SA2 toward the second turbine T2. In this embodiment of the invention, the first flap valve KV1 de facto takes over the functions of the first rotary valve DV1 and the third rotary valve D3, which are shown and described in Fig. 2.

[0073] The corresponding suction curve for series operation SM of vacuum cleaner 10 with flap valves KV essentially corresponds to the suction curve for series operation SM of vacuum cleaner 10 with rotary valves DV. Even with the valve arrangement V, which includes flap valves KV, an approximate doubling of the achievable vacuum values ​​-p can be achieved.

[0074] Figure 4 shows a preferred embodiment of the vacuum cleaner 10 in parallel operation PM with rotary valves DV. The three rotary valves DV are again located in the known positions, i.e. the first rotary valve DV1 in the suction channel SK between the turbines T1, T2, the second rotary valve DV2 in the second suction section SA2 and the third rotary valve DV3 in the first outlet section AA1. In the embodiment of the vacuum cleaner 10 in parallel operation PM with rotary valves DV shown in Figure 4, the suction flow S in the dust collection container 12 is divided into two partial suction flows TS1, TS2. The first partial suction flow TS1 flows from the dust collection container 12 through the filter unit F, through the first suction section SA1, through the first turbine T1, through the open third rotary valve DV3 and the first outlet section AA1 and leaves the vacuum cleaner 10 as outgoing air flow aLS through the first inlet or outlet opening O1.The second partial suction flow TS2 flows from the dust collection container 12 through the filter unit F, through the open second rotary valve DV2 and the second suction section SA2, through the second turbine T2 and through the second outlet section AA2 and leaves the vacuum cleaner 10 as an outgoing air flow aLS through the second inlet or outlet opening O2. Thus, the position of the rotary valves DV of the valve arrangement V in the embodiment of the invention shown in Figure 4 represents exactly the slide to the position of the rotary valves DV of the valve arrangement V in the embodiment of the invention shown in Figure 2.While in the embodiment in Figure 2 the first rotary valve DV1 is open and the second rotary valve DV2 and the third rotary valve DV3 are closed, in the embodiment in Figure 4 the first rotary valve DV1 in the suction channel SK is closed, while the second rotary valve DV2 in the second suction section SA2 and the third rotary valve DV3 in the first outlet section AA1 are open.

[0075] The lower section of Figure 4 shows the suction curve, which shows the course of the volume flow Q as a function of the negative pressure -p in parallel operation PM of the vacuum cleaner 10. The course of the volume flow Q as a function of the negative pressure -p, when only one turbine is used, is marked in the suction curve with "T1", while the course of the volume flow Q as a function of the negative pressure -p in parallel operation PM of both turbines T1, T2 is marked with "T(1+2)_P". It can be clearly seen that when using two turbines T1, T2, operated in parallel operation PM, almost twice the volume flow Q can be achieved compared to operation of the vacuum cleaner 10 with only one turbine ("T1").

[0076] Figure 5 shows a preferred embodiment of the vacuum cleaner 10 in parallel operation PM with a valve arrangement V which comprises two flap valves KV. The flap valves KV are arranged as in the exemplary embodiment shown in Figure 3. This means that the first flap valve KV1 is arranged in the region of the T-junction in the direction of the suction flow S behind the first turbine T1, while the second flap valve KV2 is arranged in the second suction section SA2 between the filter unit F and the second turbine T2. In the exemplary embodiment of the invention shown in Figure 5, the first flap valve KV1 is set such that the first partial suction flow TS1 can flow through the first outlet section AA1 and leave the vacuum cleaner 10 through the first inlet or outlet opening O1 as outgoing air flow aLS.In the exemplary embodiment of the invention illustrated in Figure 5, the second flap valve KV2 is set such that the second suction section SA2 is open and the second partial suction flow TS2 can flow from the dust collection container 12 toward the second turbine T2. The corresponding suction curve for parallel operation PM of the vacuum cleaner 10 with flap valves KV essentially corresponds to the suction curve for parallel operation PM of the vacuum cleaner 10 with rotary valves DV. Even with the valve arrangement V, which includes flap valves KV, approximately double the desired volume flow Q can be achieved.

[0077] Figure 6 shows a combined suction curve, or rather how the suction curve of the proposed vacuum cleaner 10 results from operating the vacuum cleaner 10 either in series operation SM or in parallel operation PM as a combination of the suction curves described so far. The invention is based on the idea that the operation of the vacuum cleaner 10 can be switched from a first operating mode - for example, the parallel operation PM mode - to a second operating mode - for example, the series operation SM mode - depending on determined negative pressure values ​​-p. The switching preferably occurs at a switching point SP, which in the sense of the invention can preferably also be referred to as a "negative pressure-triggered switching point SP". For example, the vacuum cleaner 10 can be operated in the parallel operation PM mode at low negative pressure values ​​and in the series operation SM mode at higher negative pressure values.Figure 6 shows various curves of volume flow rates Q versus negative pressure -p. For example, the curve of the volume flow rate Q is shown for the operation of a vacuum cleaner with one turbine, which occurs, for example, when the proposed vacuum cleaner 10 is operated with only one turbine T - for example, the first turbine T1. This curve is labeled "T1" in Fig. 6. In addition, the curves of the volume flow rates Q versus negative pressure -p are shown for parallel operation ("T(1+2)_P") and series operation ("T(1+2)_S"). The operation of the vacuum cleaner 10 can now be optimized by operating the vacuum cleaner 10 in parallel operation PM for low negative pressure values ​​-p, while operating the vacuum cleaner 10 in series operation SM for higher negative pressure values ​​-p.In between, a switchover takes place between the operating modes parallel operation PM («first operating mode») and series operation SM («second operating mode»). The switchover preferably takes place at the switchover point SP, which is characterized by a switchover negative pressure value -p(SP).

[0078] To determine the negative pressure values ​​-p, the vacuum cleaner 10 may have suitable sensors (not shown). Furthermore, the vacuum cleaner 10 may include a control device (not shown) configured to control the vacuum cleaner 10 or to initiate switching between the operating modes of the vacuum cleaner 10.

[0079] Figure 7 shows a possible combined suction curve «in its purest form», where the abbreviation «PM» indicates the area of ​​the suction curve in which the vacuum cleaner 10 is operated in parallel mode PM (on the x-axis: «first vacuum range», UB1), while the abbreviation «SM» indicates the area of ​​the suction curve in which the vacuum cleaner 10 is operated in series mode SM (on the x-axis: «second vacuum range», UB2).

[0080] Figure 8 shows a preferred embodiment of the vacuum cleaner 10 with a filter cleaning function. Figure 8 essentially corresponds to Figure 1, wherein in Figure 8 an additional rotary valve DV4 is shown and the filter unit F is divided into two parts. The filter unit F of the embodiment of the vacuum cleaner 10 shown in Figure 8 can comprise a first filter section FA1 and a second filter section FA2, wherein the filter sections FA1, FA2 can be cleaned separately from one another. The first rotary valve DV1, the second rotary valve DV2 and the third rotary valve DV3 are arranged in the known positions, i.e. the first rotary valve DV1 in the suction channel SK, the second rotary valve DV2 in the second suction section SA2 and the third rotary valve DV3 in the first outlet section AA1. The fourth rotary valve DV4 is preferably arranged in the first suction section SA1 between the filter unit F and the first turbine T1.This allows the fourth rotary valve DV4 to close or open the first suction section SA1. If the vacuum cleaner 10 has a filter cleaning function, ambient air can flow into the vacuum cleaner 10 through the first inlet or outlet opening O1 or through the second inlet or outlet opening O2. By opening the first inlet or outlet opening O1 or the second inlet or outlet opening O2, a cleaning flow AS can be generated, which flows through the vacuum cleaner 10 opposite to the flow direction of the suction flow S.

[0081] The incoming air flow eLS, which enters the vacuum cleaner 10 through the first inlet or outlet opening O1, can preferably flow through the first turbine T1, further through the first suction section SA1 and the open fourth rotary valve DV4 and expose the first filter section FA1 to ambient air. The ambient air entering the vacuum cleaner 10 through the first inlet or outlet opening O1 can form a first cleaning flow AS1, which enables backwashing of the first filter section FA1 of the filter unit F of the vacuum cleaner 10. This first cleaning flow AS1 and its course are shown in particular in Figure 9. During the cleaning and rinsing of the first filter section FA1, which is preferably assigned to the first turbine T1, the suction operation of the vacuum cleaner 10 can be continued by the second turbine T2.This ensures continuous suction operation of the vacuum cleaner 10 - even during filter cleaning. In this embodiment of the invention, the second rotary valve DV2, the third rotary valve DV3 and the fourth rotary valve DV4 are open, while the first rotary valve DV1 is closed. An incoming air flow eLS is sucked into the vacuum cleaner 10 through the first inlet or outlet opening O1, while the suction flow S leaves the vacuum cleaner 10 through the second inlet or outlet opening O2 as an outgoing air flow aLS. The suction of ambient air through the first inlet or outlet opening O1 can be achieved solely by the pressure difference between the interior of the vacuum cleaner 10 and its surroundings. However, within the meaning of the invention, it may also be preferable to assist the suction by reversing the direction of rotation of the first turbine 1.

[0082] The incoming air flow eLS, which enters the vacuum cleaner 10 through the second inlet or outlet opening 02, can preferably flow through the second turbine T2, further through the second suction section SA2 and the open second rotary valve DV2 and the second filter section FA2 with ambient air. The ambient air that enters the vacuum cleaner 10 through the second inlet or outlet opening 02 can form a second cleaning flow AS2, which enables backwashing of the second filter section FA2 of the filter unit F of the vacuum cleaner 10. This second cleaning flow AS2 and its course are shown in particular in Figure 10. During the cleaning and rinsing of the second filter section FA2, which is preferably assigned to the second turbine T2, the suction operation of the vacuum cleaner 10 can be continued by the first turbine T1.In this embodiment of the invention, which is shown in Figure 10, the second rotary valve DV2, the third rotary valve DV3 and the fourth rotary valve DV4 are also open, while the first rotary valve DV1 is closed.

[0083] An incoming air flow eLS is sucked into the vacuum cleaner 10 through the second inlet or outlet opening O2, while the suction flow S leaves the vacuum cleaner 10 through the first inlet or outlet opening O1 as an outgoing air flow aLS. The suction of ambient air through the second inlet or outlet opening O2 can be achieved solely by the pressure difference between the interior of the vacuum cleaner 10 and its surroundings. However, within the meaning of the invention, it may also be preferable to assist the suction by reversing the direction of rotation of the second turbine 2.

[0084] In order to control the opening and closing of the individual valves and openings and thus the cleaning of the filter F of the vacuum cleaner 10, the vacuum cleaner 10 can have a control device (no reference number, not shown). The control device can be configured to open and close the individual valves and openings of the vacuum cleaner 10. The filter F of the vacuum cleaner 10 can be divided into two parts and, for example, comprise a first filter section FA1 and a second filter section FA2. It can be preferred within the meaning of the invention for the control device to control the valves and openings of the vacuum cleaner 10 such that the filter sections FA1, FA2 are cleaned essentially alternately.The wording “essentially alternating” includes both the cases in which the filter sections FA1, FA2 are cleaned strictly one after the other and the cases in which the filter sections FA1, FA2 are cleaned with a temporal overlap. In this latter case, for example, the cleaning of the first filter section FA1 can still be ongoing while the cleaning of the second filter section FA2 has already begun. However, within the meaning of the invention, it can just as well be preferred that the filter sections FA1, FA2 of the filter unit F are cleaned as needed, for example as a function of a pressure loss in the area of ​​the filter unit F. In the case of a needs-based cleaning of the filter sections FA1, FA2 of the vacuum cleaner 10, pressure transducers or sensors can be provided to determine the pressure in the suction channels or suction sections of the vacuum cleaner 10.

[0085] For example, the grid G ​​(see Figures 8-12), which is arranged in the connection area VB above the filter unit F, can be closed the moment the filter cleaning is triggered. This can be effected, for example, by the control device. By closing the grid G, the filter sections FA1, FA2 can be fluidically separated from one another so that no more air can be exchanged between the filter sections FA1, FA2. Once the filter cleaning is complete, the grid G ​​can be opened again so that the fluidic connection between the filter sections FA1, FA2 can be restored. Various, preferably axial, movement elements can be used as actuators for the grid G. For example, the grid G ​​can be driven or moved using an electromagnetic lifting element, a pneumatic pressure cell or an electric rotary drive, without being limited to these.

[0086] Figures 11 to 13 show an alternative embodiment of the vacuum cleaner 10 or its valve arrangement V, wherein the vacuum cleaner 10 comprises a two-part filter unit F, which in turn has a first filter section FA1 and a second filter section FA2. Figure 11 generally shows a possible structure of a valve arrangement V which enables alternating cleaning of the filter sections FA1, FA2. In the exemplary embodiment of the invention shown in Figure 11, rotary valves DV or flap valves KV are arranged in the first outlet section AA1 and in the suction channel SK between the turbines T1, T2 of the vacuum cleaner 10. These rotary valves DV or flap valves KV are preferably designed to close or open the first outlet section AA1 or the suction channel SK.In addition, the vacuum cleaner 10 in its embodiment shown in Figure 11 has a first backwash opening RS1 and a second backwash opening RS2, wherein the first backwash opening RS1 is arranged in the first suction section SA1 and the second backwash opening RS2 is arranged in the second suction section SA2 or opens into it. A short line section can be located between the backwash openings RS1, RS2 and the suction sections SA1, SA2. The backwash openings RS1, RS2 can each be closed or opened by a three-way valve W, wherein a first three-way valve VW1 is preferably assigned to the first backwash opening RS1 and a second three-way valve WV2 is assigned to the second backwash opening RS2. Preferably, the first backwash opening RS1 and the first three-way valve WV1 are assigned to the first filter section FA1 and the second backwash opening RS2 and the second three-way valve WV2 are assigned to the second filter section FA2.

[0087] In the embodiment of the vacuum cleaner 10 shown in Figure 11, there is a rotary valve DV1 in the suction channel SK between the turbines T1, T2, which is closed in the operating situation of the vacuum cleaner 11 shown in Figure 11 and when the first filter section FA1 is being cleaned (see Figure 12) in order to prevent a flow between the turbines T1, T2, while the rotary valve DV1 in the suction channel SK of the vacuum cleaner 10 is open when the second filter section FA2 is being cleaned (see Figure 13) so that the turbines T1, T2 of the vacuum cleaner 10 can be flowed through one after the other.In the first outlet section AA1, for example, there may be a rotary valve DV3 which is open in the operating situation of the vacuum cleaner 11 shown in Figure 11 and when the first filter section FA1 is being cleaned (see Figure 12), while the rotary valve DV3 in the first outlet section AA1 is preferably closed when the second filter section FA2 is being cleaned (see Figure 13).

[0088] The filter unit F of the vacuum cleaner 10 shown in Figure 11 has a connecting area VB between the filter sections FA1, FA2. This connecting area VB can be open or closed. In Figure 11, for example, the connecting area VB between the filter sections FA1, FA2 is open, so that the filter sections FA1, FA2 essentially form a single filter unit F. When one of the two filter sections FA1, FA2 is cleaned, the connecting area VB is preferably closed, so that the filter sections FA1, FA2 form separate or independently functioning filter units. The connecting area VB can function as a gateway and, for example, comprise the grille G.

[0089] Figure 12 shows that the first three-way valve WV1 can be opened to open the first backwash opening RS1. This advantageously generates a first backwash flow RSS1, which is suddenly sucked into the vacuum cleaner 10 due to the pressure difference between the interior of the vacuum cleaner 10 and its surroundings. In addition, the filter unit F or the first filter section FA1 is decoupled from the first turbine T1, so that no more suction flow S flows through this half of the vacuum cleaner 10. The first backwash flow RSS1 can flow from the first backwash opening RS1 through the first filter section FA1 and thereby clean this first filter section FA1. While the first filter section FA1 is being cleaned, a second partial suction flow TS2 can continue to flow through the second filter section FA2 and the second turbine T2.This is advantageously made possible by a corresponding position of the second three-way valve WV2, which releases the second suction section SA2 when the first filter section FA1 is cleaned, so that the second partial suction flow TS2 can flow from the dust collection container 12 through the second filter section FA2 in the direction of the second turbine T2, so that the suction operation of the vacuum cleaner 10 can be maintained in this way.

[0090] Analogous to Figure 12, Figure 13 shows a cleaning of the second filter section FA2, while the suction operation of the vacuum cleaner 10 is maintained by a first partial suction flow TS1 through the first filter section FA1 and the first turbine T1. Figure 13 shows that the two three-way valves WV2 can be opened so that the second backwash opening RS2 is opened. This advantageously allows a second backwash flow RSS2 to be generated, which is suddenly sucked into the vacuum cleaner 10 due to the pressure difference between the interior of the vacuum cleaner 10 and its surroundings. In addition, the filter unit F or the first filter section FA2 is decoupled from the first turbine T2, so that no suction flow S can flow through this half of the vacuum cleaner 10.The second backwash flow RSS2 can flow from the second backwash opening RS2 through the second filter section FA2 and clean this second filter section FA2 in this way. While the second filter section FA2 is being cleaned, a first partial suction flow TS1 can continue to flow through the first filter section FA1 and the first turbine T1. This is advantageously made possible by a corresponding position of the first three-way valve WV1, which opens the first suction section SA1 when the second filter section FA2 is being cleaned, so that the first partial suction flow TS1 can flow from the dust collection container 12, through the first filter section FA1 in the direction of the first turbine T1, so that the suction operation of the vacuum cleaner 10 is maintained in this case by the left half of the vacuum cleaner 10. List of reference symbols.

[0091] 10 vacuum cleaners

[0092] 12 dust collection containers

[0093] 14 Suction hose inlet

[0094] T1 first turbine

[0095] T2 second turbine

[0096] V valve arrangement

[0097] KV flap valve

[0098] KV1 first flap valve

[0099] KV2 second flap valve

[0100] DV rotary valve

[0101] DV1 first rotary valve

[0102] DV2 second rotary valve

[0103] DV3 third rotary valve

[0104] DV4 fourth rotary valve

[0105] S suction flow

[0106] TS1 first partial suction flow

[0107] TS2 second partial suction flow

[0108] AS cleaning stream

[0109] AS1 first cleaning stream

[0110] AS2 second cleaning stream

[0111] SK suction channel

[0112] SA1 first suction section

[0113] SA2 second suction section AA1 first outlet section

[0114] AA2 second exit section

[0115] O1 first inlet or outlet opening

[0116] 02 second inlet or outlet opening

[0117] F filter unit

[0118] FA1 first filter section

[0119] FA2 second filter section

[0120] T(1+2)_S: joint operation of the first and second turbine in series operation

[0121] T(1+2)_P: joint operation of the first and second turbines in parallel operation

[0122] - p suppression v flow velocity

[0123] SP switching point

[0124] SM series operation

[0125] PM Parallel operation eLS Air flow entering the vacuum cleaner aLS Air flow leaving the vacuum cleaner

[0126] -p(SP) Negative pressure value of the switching point SP

[0127] UB1 first negative pressure area

[0128] UB2 second negative pressure area

[0129] WV1 first three-way valve

[0130] WV2 second three-way valve

[0131] RS1 first backwash opening

[0132] RS2 second backwash opening

[0133] RSS1 first backwash flow

[0134] RSS2 second backwash flow VB connection area between the filter sections

[0135] G Grid

Claims

Patent claims 1. Vacuum cleaner (10) with a first turbine (T1) and a second turbine (T2), wherein the turbines (T1, T2) are designed to generate a suction flow (S) for sucking in dust, characterized in that the vacuum cleaner (10) has a valve arrangement (V), wherein the valve arrangement (12) is designed to allow the suction flow (S) to flow through the turbines (T1, T2) one after the other or in parallel to one another.

2. Vacuum cleaner (10) according to claim 1, characterized in that the valve arrangement (V) comprises at least one flap valve (KV) and / or at least one rotary valve (DV).

3. Vacuum cleaner (10) according to one of claims 1 or 2, characterized in that the valve arrangement (V) comprises at least a first flap valve (KV1) and a second flap valve (KV2), wherein the first flap valve (KV1) is arranged behind the first turbine (T1) in a suction flow direction and wherein the second flap valve (KV2) is arranged in front of the second turbine (T2) in a suction flow direction.

4. Vacuum cleaner (10) according to claim 3, characterized in that the first flap valve (KV1) allows the suction flow (S) to flow either in the direction of a first inlet or outlet opening (O1) or in the direction of the second turbine (T2), and wherein the second flap valve (KV2) allows or prevents a flow of the suction flow (S) through the second turbine (T2).

5. Vacuum cleaner (10) according to one of claims 1 or 2, characterized in that the valve arrangement (V) comprises at least a first rotary valve (DV1) and a second rotary valve (DV2), wherein the first rotary valve (DV1) is arranged between the first turbine (T1) and the second turbine (T2) and wherein the second rotary valve (DV2) is located between the second turbine (T2) and a filter unit (F).

6. Vacuum cleaner (10) according to claim 5, characterized in that the first rotary valve (DV1) is designed to close or open a suction channel (SK) between the first turbine (T1) and the second turbine (T2), wherein the second rotary valve (DV2) is designed to close or open a second suction section (SA2) between the second turbine (T2) and a filter unit (F).

7. Vacuum cleaner (10) according to one of claims 5 or 6, characterized in that the valve arrangement (V) comprises a third rotary valve (DV3), wherein the third rotary valve (DV3) is arranged between the first turbine (T1) and the first inlet or outlet opening (O1).

8. Vacuum cleaner (10) according to one of claims 5 to 7, characterized in that the third rotary valve (DV3) is designed to close or open a first outlet section (AA1) between the first turbine (T1) and the first inlet or outlet opening (O1).

9. Vacuum cleaner (10) according to one of the preceding claims, characterized in that the valve arrangement (V) is designed to allow a cleaning flow (AS) to flow through the first turbine (T1) and / or the second turbine (T2) in a direction opposite to the suction flow (S).

10. Vacuum cleaner (10) according to one of the preceding claims, characterized in that the vacuum cleaner (10) comprises a filter unit (F) for filtering the suction flow (S), wherein the filter unit (F) has a first filter section (FA1) and a second filter section (FA2), wherein the first filter section (FA1) is provided with a first cleaning cleaning area (AB1) is assigned and a second cleaning area (AB2) is assigned to the second filter section (FA2).

11. Vacuum cleaner (10) according to claim 10, characterized in that the cleaning stream (AS) flows through the first turbine (T1) when cleaning the first filter section (FA1) and wherein the cleaning stream (AS) flows through the second turbine (T2) when cleaning the second filter section (FA2).

12. Vacuum cleaner (10) according to claim 10 or 11, characterized in that the valve arrangement (V) comprises a first three-way valve (WV1) and a second three-way valve (WV2), wherein the first three-way valve (WV1) is designed to close or open a first backwash opening (RS1), wherein a first backwash flow (RSS1) flows through the first filter section (FA1), and wherein the second three-way valve (WV2) is designed to close or open a second backwash opening (RS2), wherein a second backwash flow (RSS2) flows through the second filter section (FA1).

13. Vacuum cleaner (10) according to one of claims 5 to 12, characterized in that the valve arrangement (V) comprises a fourth rotary valve (DV4), wherein the fourth rotary valve (DV4) is arranged between the first turbine (T1) and the filter unit (F) and is designed to close or open a first suction section (SA1) between the first turbine (T1) and the filter unit (F).

14. Method for operating a vacuum cleaner (10) according to one of the preceding claims, wherein the method is characterized by the following method steps: a) providing a vacuum cleaner (10) with a first turbine (T1) and a second turbine (T2), b) controlling a valve arrangement (V) of the vacuum cleaner (10) so that a suction flow (S) flows either sequentially or in parallel through the turbines (T1, T2).

15. Method according to claim 14, characterized in that the method comprises a determination and / or evaluation of operating data of the vacuum cleaner (10), wherein the control of the valve arrangement (V) of the vacuum cleaner (10) takes place as a function of the previously determined operating data.

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