coffee machine

Abstract

Coffee machine (1),- with a water tank (2) which communicates fluidically with a functional component (4a) via a water line (3), so that water (W) present in the water tank (2) can be introduced into the functional component (4a) via the water line (3),- with a conveying device (5) arranged in the water line (3) for conveying water (W) from the water tank (2) into the functional component (4a),- with a heating device (6) arranged between the conveying device (5) and the functional component (4a) in the water line (3) for heating the water (W) flowing through the water line (3),- with a bypass valve (7) through which, in an open position of the bypass valve (7), water can be diverted past the conveying device (5),- with a shut-off valve (8) arranged in the water line (3) between the heating device (6) and the functional component (4a), which closes the water line (3) in a closed position,so that no water (W) can flow from the heating device (6) into the functional component (4a),- wherein the coffee machine (1) comprises a control / regulating device (9) by means of which the bypass valve (7) can be adjusted between the open position and a closed position in which no water (W) can bypass the conveying device (5), and by means of which the shut-off valve (8) can be adjusted between the closed position and an open position in which water (W) can flow from the heating device (6) into the functional component (4a),- wherein the coffee machine (1) can be adjusted into a first operating state and a second operating state by means of the control / regulating device (9),- wherein in the first operating state the bypass valve (7) is adjusted by the control / regulating device (9) into the closed position and the shut-off valve (8) is adjusted into the open position,- wherein in the second operating state the bypass valve (7) is adjusted by the control / regulating device (9) to the open position and the shut-off valve (8) to the closed position.

Description

The invention relates to a coffee machine. The invention further relates to a method for operating such a coffee machine. Coffee machines of this type - with a water tank which communicates fluidically with a functional component via a water line and with a conveying device arranged in the water line - and methods for their operation are known, for example, from DE 10 2018 104 573 A1, DE 10 2007 032 288 A1 and DE 10 2012 105 443 A1. To remove limescale deposits that form in the water and steam components of coffee machines through use, regular maintenance with a cleaning agent can be performed. This also applies to removing soiling that accumulates in the coffee product-carrying components of coffee machines through use, especially during coffee preparation. This is particularly important to prevent the spread of mold and germs. For this purpose, a descaling agent is often added to a container designed for a cleaning fluid to remove limescale deposits. Alternatively, a cleaning agent can be added to the brewing chamber of the coffee machine or to the container. After adding the cleaning fluid, the cleaning process can be carried out. With conventional coffee machines, however, usually only water- and steam-carrying components located downstream of the cleaning fluid reservoir or downstream of a water or steam pump can be cleaned or descaled, as the pump is designed to move water in only one direction – away from the reservoir. Therefore, to clean or descale the coffee machine's water tank and the lines between it and the pump, a suitable cleaning fluid must first be introduced into the water tank. This fluid is then pumped from the tank by the pump. It is therefore an object of the present invention to provide an improved embodiment of a coffee machine in which the disadvantages described above are at least partially, and ideally completely, eliminated. Furthermore, a method for operating a coffee machine is to be provided in which simple and effective maintenance of the coffee machine's water tank and water- and steam-carrying components, such as water lines, between the water tank and a conveying device of the coffee machine is achieved. This problem is solved according to the invention by the subject matter of the independent claims. Advantageous embodiments are the subject matter of the dependent claims. The basic idea of ​​the invention is therefore to direct the water or cleaning fluid, which is heated in a coffee machine's heating element, to a water tank of the coffee machine using the water / steam pressure generated during heating. For this purpose, a bypass valve of a bypass leading away from the conveying element is opened, and a shut-off valve arranged between the heating element and a functional component, in particular a brewing chamber, is closed. In this way, the water tank and water- and steam-carrying components located between the water tank and the conveying element, such as water pipes, can be cleaned without using the conveying element and without introducing a corresponding cleaning fluid into the water tank. A coffee machine according to the invention comprises a water tank which communicates fluidically with a functional component via a water line, so that water present in the water tank can be introduced into the functional component via the water line. The coffee machine according to the invention also comprises a conveying device arranged in the water line for conveying water from the water tank into the functional component and a heating device arranged between the conveying device and the functional component in the water line for heating the water flowing through the water line.Furthermore, the coffee machine has a bypass valve, through which water can bypass the pumping unit when the bypass valve is open, and a shut-off valve located in the water line between the heating unit and the functional component, which closes the water line in a closed position so that no water can flow from the heating unit into the functional component. The coffee machine also includes a control device by which the bypass valve can be adjusted between an open position and a closed position in which no water can bypass the pumping unit, and by which the shut-off valve can be adjusted between a closed position and an open position in which water can flow from the heating unit into the functional component.By means of the control / regulation device, the coffee machine can be adjusted to a first operating state and a second operating state, wherein in the first operating state the bypass valve is adjusted by the control / regulation device to the closed position and the shut-off valve to the open position, and wherein in the second operating state the bypass valve is adjusted by the control / regulation device to the open position and the shut-off valve to the closed position. According to a preferred embodiment, the pumping device is adjustable by means of the control unit between an active state, in which it pumps water from the water tank to the functional component, and an inactive state, in which the pumping device does not pump any water. In the first operating state of the coffee machine, the pumping device is set to the active state by the control unit, and in the second operating state, it is set to the inactive state. Using this embodiment, water can be directed to a functional component for coffee preparation in the first operating state, and a maintenance fluid can be transported to the water tank in the second operating state without the use of a pumping device. According to a further preferred embodiment, the heating device is adjustable by means of the control device between an active state, in which the water passing through the heating device is heated by it, and an inactive state, in which the water passing through the heating device is not heated by it. In the second operating state of the coffee machine, the heating device is set to the active state. With this embodiment, pressure can be built up in the water or the maintenance fluid by heating in the second operating state, and thus the heated and pressurized water or maintenance fluid can be conveyed to the water tank via the water- and steam-carrying components of the coffee machine without activating the pumping device. The heating element is conveniently set to active mode even in the coffee machine's initial operating state. This allows water from the water tank to be heated for brewing coffee or other hot beverages. According to an advantageous embodiment, the coffee machine has a reservoir for a lubricating fluid, which opens into the water line between the water tank and the heating element, particularly in the area of ​​the bypass valve. This allows the introduction of a lubricating fluid for cleaning the water- and steam-carrying components of the coffee machine. According to a further advantageous embodiment, the pumping device comprises a oscillating piston pump designed such that it can pump water present in the water line towards the functional component, but not towards the water tank. This enables efficient pumping of water from the water tank to the functional component in the first operating state. The functional component is typically a brewing chamber, a drainage system, or a coffee outlet. This allows coffee to be prepared and dispensed from the coffee machine during initial operation, or these functional components can be cleaned through a maintenance process. The invention further relates to a method for operating a coffee machine as previously described. According to the method, in the first operating state of the coffee machine, water or a cleaning fluid is conveyed by the conveying device through the water line, via the heating device, to the functional component. In the second operating state of the coffee machine, with the conveying device inactive, water or cleaning fluid located in the water line is heated by the active heating device and thus transported from the water line to the water tank or evaporated. In this way, both the preparation of coffee and the cleaning of the water- and steam-carrying components of the coffee machine are made possible.Likewise, the water tank and water and steam-carrying components of the coffee machine, such as water pipes, between the water tank and the shut-off valve can be cleaned or descaled by the heated water or - after adding a care fluid to the container for the care fluid - by the heated care fluid. The coffee machine is preferably operated in the first operating mode, at least until the water or cleaning fluid reaches the heating element, and then switched to the second operating mode. This ensures that a particularly large amount of water or cleaning fluid is heated by the heating element and can be used for cleaning or descaling. At the same time, this creates a particularly high pressure in the water or cleaning fluid, so that it is efficiently directed to the water tank. It is particularly preferred that the second operating state be maintained until no water remains in the water line, especially in the entire area between the shut-off valve and the water tank. Using this embodiment, the water- and steam-carrying components of the coffee machine are cleaned particularly thoroughly and simultaneously made free of water or cleaning fluid for subsequent operation in the first operating state. Further important features and advantages of the invention will become apparent from the dependent claims, the drawing and the associated description of the figures based on the drawing. It is understood that the features mentioned above and those to be explained below can be used not only in the combinations specified, but also in other combinations or on their own, without leaving the scope of the present invention. Preferred embodiments of the invention are shown in the drawing and are explained in more detail in the following description, where identical reference numerals refer to identical or similar components. Figure 1 illustrates an example of a coffee machine 1 according to the invention. The coffee machine 1 is equipped with a housing 1a, which surrounds an interior housing space 1b. A water tank 2 and a functional component 4a in the form of a brewing chamber 4 are arranged in the interior housing space 1b. The water tank 2 and the brewing chamber 4 communicate fluidically with each other via a water line 3, so that water W present in the water tank can be transported into the brewing chamber 4 via the water line 3. The brewing chamber 4 opens fluidically into a coffee outlet 11, which in turn communicates fluidically with a drain (not shown in Figure 1). To pump water W from the water tank 2 into the brewing chamber 4, a pumping device 5 is arranged in the water line 3. In the example shown in Fig. 1, the pumping device 5 is a diaphragm pump 5a, which is designed such that water W present in the water line 3 can be pumped by it towards the brewing chamber 4, but not towards the water tank 2. A heating device 6 for heating the water W flowing through the water line 3 is also arranged in the water line 3 between the pumping device 5 and the brewing chamber 4. The coffee machine 1 also includes a bypass 12 with a bypass valve 7, through which, in an open position of the bypass valve 7, water W can be routed past the conveying device 5. The coffee machine 1 also includes a shut-off valve 8 arranged in the water line 3 between the heating device 6 and the brewing chamber 4, which in a closed position closes the water line 3 so that no water W can flow from the heating device 6 into the brewing chamber 4. The coffee machine 1 also has a control / regulating device 9, which communicates with the feed unit 5, the heating unit 6, the bypass valve 7, and the shut-off valve 8. The control / regulating device 9 allows the bypass valve 7 to be adjusted between an open position and a closed position in which no water W can bypass the feed unit 5. The control / regulating device 9 also allows the shut-off valve 8 to be adjusted between a closed position and an open position in which water W can flow from the heating unit 6 into the brewing chamber 4. By means of the control / regulation device 9, the conveying device 5 can also be adjusted between an active state, in which the conveying device 5 conveys water W from the water tank 2 to the brewing chamber 4, and an inactive state, in which the conveying device 5 does not convey any water W. By means of the control / regulation device 9, the heating device 6 can also be adjusted between an active state, in which the water W flowing through the heating device 6 is heated by it, and an inactive state, in which the water W flowing through the heating device 6 is not heated by it. The coffee machine 1 can be adjusted between a first operating state and a second operating state by means of the control / regulating device 9. In the first operating state, the bypass valve 7 is set to the closed position and the shut-off valve 8 to the open position by the control / regulating device 9. Furthermore, in the first operating state, the pump 5 and the heating element 6 are each set to their active state. Thus, water W from the water tank 2 can be heated by the heating element 6 and supplied to the brewing chamber 4. In the second operating state, the bypass valve 7 is set to the open position and the shut-off valve 8 to the closed position by the control / regulating device 9. Furthermore, in the second operating state, the pumping device 5 is set to the inactive state and the heating device 6 to the active state. Thus, heated and pressurized water W or care fluid from the heating device 6 can be transported to the water tank 2 without using the pumping device 5 or any other pumping device. The coffee machine 1 also includes a container 10 of a care fluid, which flows into the water line 3 between the water tank 2 and the heating unit 6 and between the conveying unit 5 and the heating unit 6. The inventive method for operating the coffee machine 1 is explained below by way of example. In the first operating state of the coffee machine 1, as described above, water W or a maintenance fluid (not shown in Fig. 1) is conveyed by the conveying device 5 through the water line 3, via the heating device 6, and through the shut-off valve 8 to the brewing chamber 4. In the second operating state of the coffee machine 1, also described above, with the conveying device 5 inactive, water W or maintenance fluid in the water line 3 is heated by the active heating device 6 and thus transported via the water line 3 and the bypass valve 7 to the water tank 2 or evaporates. The coffee machine 1 can initially be operated in the first operating state until the water W or the maintenance fluid has reached at least the heating element 6, and then it can be switched to the second operating state. The second operating state can then be maintained until there is no more water W or maintenance fluid in the water line 3 and in the entire area between the shut-off valve 8 – or at least the heating element 6 – and the water tank 2. Reference symbol list 1 Coffee machine 1a Housing 1b Housing interior 2 Water tank 3 Water line 4 Brewing chamber 4a Functional component 5 Feeding device 5a Oscillating piston pump 6 Heating device 7 Bypass valve 8 Shut-off valve 9 Control / regulating device 10 Container for maintenance fluid 11 Coffee outlet 12 Bypass

Claims

Coffee machine (1),- with a water tank (2) which communicates fluidically with a functional component (4a) via a water line (3), so that water (W) present in the water tank (2) can be introduced into the functional component (4a) via the water line (3),- with a conveying device (5) arranged in the water line (3) for conveying water (W) from the water tank (2) into the functional component (4a),- with a heating device (6) arranged between the conveying device (5) and the functional component (4a) in the water line (3) for heating the water (W) flowing through the water line (3),- with a bypass valve (7) through which, in an open position of the bypass valve (7), water can be diverted past the conveying device (5),- with a shut-off valve (8) arranged in the water line (3) between the heating device (6) and the functional component (4a), which closes the water line (3) in a closed position,so that no water (W) can flow from the heating device (6) into the functional component (4a),- wherein the coffee machine (1) comprises a control / regulating device (9) by means of which the bypass valve (7) can be adjusted between the open position and a closed position in which no water (W) can bypass the conveying device (5), and by means of which the shut-off valve (8) can be adjusted between the closed position and an open position in which water (W) can flow from the heating device (6) into the functional component (4a),- wherein the coffee machine (1) can be adjusted into a first operating state and a second operating state by means of the control / regulating device (9),- wherein in the first operating state the bypass valve (7) is adjusted by the control / regulating device (9) into the closed position and the shut-off valve (8) is adjusted into the open position,- wherein in the second operating state the bypass valve (7) is adjusted by the control / regulating device (9) to the open position and the shut-off valve (8) to the closed position. Coffee machine according to claim 1, characterized in that the conveying device (5) is adjustable by means of the control / regulation device (9) between an active state in which it conveys water (W) from the water tank to the functional component (4a) and an inactive state in which the conveying device (5) does not convey any water, wherein the conveying device (5) is set to the active state by the control / regulation device (9) in the first operating state of the coffee machine (1) and is set to the inactive state in the second operating state. Coffee machine according to claim 1 or 2, characterized in that the heating device (6) is adjustable by means of the control / regulation device (9) between an active state in which the water (W) passed through the heating device (6) is heated by it, and an inactive state in which the water (W) passed through the heating device (6) is not heated by it, wherein the heating device (6) is set to the active state in the second operating state of the coffee machine (1). Coffee machine according to claim 3, characterized in that the heating device (6) is also set to the active state in the first operating state of the coffee machine (1). Coffee machine according to one of the preceding claims, characterized in that the coffee machine (1) has a container (10) of a maintenance fluid which opens into the water line (3) between the water tank (2) and the heating device (6), in particular in the area of ​​the bypass valve (7). Coffee machine according to one of the preceding claims, characterized in that the conveying device (5) comprises a vibrating piston pump (5a) which is designed such that water (W) present in the water line (3) can be conveyed by it in the direction of the functional component (4a), but not in the direction of the water tank (2). Coffee machine according to one of the preceding claims, characterized in that the functional component (4a) is a brewing chamber or a drainage device or a coffee outlet (4, 11). Method for operating a coffee machine (1) according to one of the preceding claims, wherein: - in the first operating state of the coffee machine (1) water (W) or a care fluid is conveyed by means of the conveying device (5) through the water line (3) via the heating device (6) to the functional component (4a), - in the second operating state of the coffee machine (1) with the conveying device (5) inactive, water (W) or care fluid located in the water line (3) is heated by the active heating device (6) and thus transported from the water line (3) to the water tank (2) or evaporated. Method according to claim 8, characterized in that the coffee machine (1) is initially operated in the first operating state, at least until the water (W) or the care fluid has reached the heating device (6), and is then switched to the second operating state. Method according to claim 8 or 9, characterized in that the second operating state is maintained until no water (W) is present in the water line (3), in particular in the entire area between shut-off valve (8) and water tank (2).

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