Washing device with improved drain hose and method for operating the washing device

Abstract

The invention relates to a washing appliance 1, comprising a tub 2 and a drum 3 rotatably mounted therein about a rotation axis 7 for receiving laundry items, and a water drainage system 4, 5, 6 comprising a tub flange 4 on the tub 2, a drainage pump 6, and a drain hose 5, 7 arranged between the tub flange 4 and the drainage pump 6, wherein the drain hose 5 is equipped with helical expansion folds 8 at least in an expansion fold region 10. The invention also relates to a method for operating the washing appliance.

Description

[0001] The invention relates to a washing appliance with an improved drain hose and a method for operating the washing appliance. The invention particularly relates to a washing appliance comprising a tub and a drum mounted therein for rotation about a rotational axis for holding laundry items, and a water drainage system comprising a tub flange in the tub, a drainage pump, and a drain hose with expansion folds arranged between the tub flange and the drainage pump or its intake port. The invention also relates to a method for operating this washing appliance.

[0002] Washing machines generally have a tub in which a drum for holding laundry items is rotatably mounted, in particular rotatably mounted, in order to introduce mechanical energy into the laundry items to increase the washing effect and to achieve the subsequent dewatering of the laundry items through centrifugal forces (spin-out principle). The drum is housed in the stationary housing of the washing machine or is mounted by springs and dampers. A drainage pump for pumping an aqueous liquid out of the tub is generally attached to this housing. There is therefore a stationary system, namely the drainage pump connected to the housing of the washing machine, and an oscillating system consisting of the tub and laundry drum, also referred to herein as the wash chamber, due to the vibrations caused by imbalance.

[0003] The drain hose, which serves as the hydraulic connection between the tub and the drain pump—that is, between the oscillating system and the stationary system—is generally made of a permanently elastic material due to the vibrations caused by imbalance and features radial expansion folds on its surface geometry. The vibration amplitudes of the washroom can thus be elastically compensated, creating a hydraulically tight connection between the stationary and oscillating systems.

[0004] Against this background, the object of the present invention was to provide a washing appliance with an improved hydraulic connection from the oscillating wash chamber to the stationary drain pump (drainage pump). Preferably, taking into account the periodically oscillating movement of the wash chamber, an improved conveyance of the two-phase medium (aqueous liquid / air) from the drain tank should be possible. The object of the invention was also to provide a method for operating this washing appliance.

[0005] This object is achieved according to the invention by a washing device and a method for operating the washing device having the features of the respective independent patent claims. Preferred embodiments of the washing device according to the invention and of the method according to the invention are listed in the dependent patent claims, wherein preferred embodiments of the method according to the invention correspond to preferred embodiments of the washing device according to the invention, even if this is not explicitly mentioned herein.

[0006] The subject of the invention is therefore a washing appliance, comprising a tub and a drum rotatably mounted therein about a rotational axis, preferably a horizontal rotational axis, for receiving laundry items, and a water drainage system comprising a tub flange in the tub, a drainage pump and a drain hose arranged between the tub flange and the drainage pump, wherein the drain hose is equipped with helical expansion folds at least in one expansion fold region.

[0007] In general, the drainage pump has an intake port and a discharge port.

[0008] In a preferred embodiment of the washing appliance, the expansion fold area extends over the length of the drain hose, although the ends of the drain hose are generally designed to ensure the tightest possible connection to the tub flange and the intake port of the drainage pump.

[0009] With regard to the drainage of an aqueous liquid from the tub or a corresponding water / air two-phase mixture, the washing machine provides an additional conveying effect due to the helical expansion folds on or at the drain hose, in addition to the gravity that promotes the drainage process and the operation of the drainage pump.

[0010] Preferably, the drain hose in the washing machine is arranged at an angle between the tub flange and the drainage pump, i.e., in particular, at an angle relative to a surface on which the washing machine is mounted. It can be arranged in three spatial configurations. The axis of the hose guide can thus be angled to all three spatial axes, namely, at an angle relative to the three spatial axes: front-back, right-left, and top-bottom, i.e., the three Cartesian axes that span a three-dimensional space at right angles to each other.

[0011] During the manufacturing of the washing device, the pitch of the screw geometry can be adjusted depending on the expected degree of change in the two-phase mixture (separation of water and air) in the axial direction of the drain hose. In particular, the pitch can be changed or adjusted from a small pitch to a larger pitch along the flow direction in the drain hose.

[0012] According to the invention, the helical expansion folds can be designed in different ways. The pitches of the helical expansion folds can be the same or variable. Furthermore, the height of the folds can vary, thus forming a spiral geometry in addition to the helical geometry.

[0013] The drain hose used according to the invention is viewed here as having an inner volume (receiving volume for the two-phase mixture from the tub) composed of a hose with a circular diameter as the inner region or core and helical expansion folds attached to the hose as the outer region. The outer diameter d of the helical expansion fold is then determined by the height of the expansion folds. In the washing appliance according to the invention, it is preferred that the outer diameter d of the drain hose decreases from the tub flange to the drainage pump, so that a spiral geometry is then established in addition to the screw geometry.

[0014] The inventive design of the drain hose with helical expansion pleats ensures better separation of the two-phase medium being conveyed. The expansion pleats primarily convey the liquid phase, while the gaseous phase is separated in the core of the drain hose and can flow back to the lye tank as a venting process.

[0015] The hose with a circular diameter as the inner region can also be referred to as a flow channel tube. According to the invention, a washing device is preferred in which the outer diameter of the flow channel tube in the drain hose is the same or decreases along the length of the drain hose. Since the gas content of the two-phase flow decreases along the flow direction in the drain hose, the flow cross-section can either be reduced along the flow direction and / or the radial extent of the expansion fold geometry can be reduced, so that in addition to the screw geometry, a spiral geometry is also created, which can decrease in diameter radially in the flow direction.

[0016] The additional conveying effect according to the invention is generally adapted to the direction of rotation of the drum in the drainage process during the geometric, i.e. constructive, design of the drain hose, so that the direction of rotation of the drum determines whether the screw geometry represents a right-hand or left-hand thread.

[0017] Preferably, the radial configuration of the screw geometry (spiral geometry) is changed from large to small diameters depending on the degree of change in the two-phase mixture (separation of water and air). The gas content of the two-phase mixture decreases in the direction of flow, since the gaseous phase has already separated and is flowing back to the liquor tank.

[0018] When designing the radial pleat geometry, the local mobility between the oscillating and stationary system is generally also taken into account. The pleat geometry should preferably become smaller in the radial direction of flow to compensate for the local oscillation paths on the discharge hose. When designing the discharge hose, the channel and pleat design with regard to the phase separation of the medium, as well as the design and characteristics of the secondary flow through the helical expansion pleats, including the influence of the cross-sectional design on the flow in the core and, primarily, on the flow velocity and thus indirectly on the phase separation of the mixture, are preferably taken into account.Finally, the design takes into account the mutual influence between primary (tube core flow) and secondary flow (in the pleats or axial-tangential channel) via the ratio between the tube core diameter and the pleat or channel outer diameter.

[0019] The additional conveying effect can be achieved by one or more threads of the screw geometry, especially if the axial gradient of the channel guide is particularly pronounced.

[0020] To monitor the torsional vibrations of the vibration system in all three rotational forms during the design phase (whether right-hand or left-hand thread is shown in the drain hose), but also during operation of the washing machine, an acceleration sensor can be helpful, which is generally integrated in the washing machine for unbalance control anyway.

[0021] In the inventive design or configuration of the drain hose of the lye container, the pump flow, i.e. the pump suction chamber and the downstream pump pressure chamber, in which, for example, the pump impeller of the radial centrifugal pump rotates (uniform or counter-swirl), is preferably also taken into account. The induced swirl in the drain hose should preferably be designed in the same direction of rotation as the pump flow. This assumes that no serious or massive flow deflections or rectifications occur in the pump suction chamber due to bends or a corresponding filter insert or lint filter, which acts as a flow straightener. This provides the best possible support for pump venting, whereby uniform swirl for the pump flow has proven to be positive for pump venting.

[0022] The drainage pump that can be used in the washing machine is not limited according to the invention. Thus, a flow pump, a centrifugal pump, or a positive displacement pump, the latter also referred to as a volumetric displacement pump, can be used in the washing machine. Positive displacement pumps are mechanical devices that transport a liquid from point A to point B by moving a pumping chamber. These pumps guarantee a constant and uniform flow because they are designed to move a fixed volume of liquid per pumping cycle. According to the invention, a radial centrifugal pump, i.e., a flow pump, is preferably used.

[0023] According to the invention, the tub flange-drain hose-drainage pump configuration can also be designed as a circulation pump system.

[0024] The degree of two-phase nature of the medium and the oscillating excitation by the oscillating system (layered container with included drum) have a direct influence on the thread pitch and the number of threads of the screw (spiral) geometry of the expansion folds of the discharge hose. The higher the proportion of the liquid phase, the greater the pitch and the more thread turns (number) should be realized in principle, since the liquid portion predominates over the gaseous phase. However, an excessively high pitch is not advisable, so according to the invention the pitch is preferably only up to 45°. Since the gas portion increases with increasing drum speed, the design of the discharge hose will generally represent a compromise that covers a wide range of the two-phase nature of the mixture.Particular attention is paid to the fact that the low speed range lies between >50 and 400 rpm, as this is typically where most of the extracted wash liquor or rinse water is generated. Therefore, a sophisticated design of the spin profile in the dewatering process can be achieved with regard to speed gradients and corresponding holding plateaus. On the other hand, the gas content of the two-phase flow is high over the entire spin block, so the expansion folds can / should be designed flatter. Thus, a sensible design compromise must be found that maximizes the dewatering performance, averaged over time, and thus achieves a corresponding optimum.

[0025] The washing appliance is generally a washing machine or a washer-dryer. It generally has a drum rotatably mounted in a tub for holding laundry items, as well as a water supply device. The latter can, for example, be a valve-controlled fresh water connection, with the valve preferably being controllable by the control unit.

[0026] The invention also relates to a method for operating a washing appliance, having a tub and a drum mounted therein so as to be rotatable about a rotation axis for receiving laundry items, and a water drainage system, comprising a tub flange on the tub, a drainage pump with an intake port and a pressure port and a drain hose arranged between the tub flange and the drainage pump, wherein the drain hose is equipped with helical expansion folds at least in one expansion fold region, and wherein the method comprises the step of rotating the drum clockwise or counterclockwise depending on whether the expansion fold geometry represents a left-hand or right-hand thread.

[0027] In the method according to the invention, the rotation of the washing machine's drum during the dewatering process, i.e., during the laundry spinning and draining process steps, generally occurs in a single, fixed and always consistent direction of rotation, which is usually determined by the tub geometry, so that no counterproductive effect of conveying in the drain hose occurs. This is because the direction of rotation of the torsional vibrations of the oscillation system (tub with washing drum and drive system) caused by imbalance depends on the selected direction of rotation of the washing drum in the tub and thus determines whether the hose should be equipped with a right-hand or left-hand thread.The drain hose must be provided with a left-hand thread for the expansion pleat geometry if the drum is rotating clockwise (CW) and conversely with a right-hand thread if the drum is rotated counterclockwise (CCW) during the drainage process and the drain hose is oriented forwards towards the operator of the washing machine.

[0028] The invention has numerous advantages. Due to the new hose geometry, the invention enables operation of the washing machine with an additional hydraulic conveying effect in the drain hose. Furthermore, an improved deaeration effect or phase separation process is achieved through better phase separation of the medium to be conveyed (liquid on the outside in the expansion pleats / gaseous on the inside in the core). It is possible to separate the two-phase fluid from the tub or in the drain hose on the way to the drain pump, so that only the liquid phase is present in the pump, enabling good pumping performance or a good or maximized flow rate. This is particularly advantageous when the drain pump is a turbomachine, because these have a significantly poorer conveying capacity for two-phase fluids than, for example, volumetrically operating positive displacement pumps.

[0029] Finally, the invention also enables improved conveyance of foreign bodies from the tub to the drain pump, as the foreign bodies cannot remain in the originally radially formed or designed expansion folds. Instead, foreign bodies are continuously transported or guided through the expansion folds in the drain hose via the threaded outlet to the accessible drain pump.

[0030] The invention is illustrated below with reference to a non-limiting embodiment of a water drainage system usable in a washing machine according to the invention. Reference is made to the Figures 1 to 4 . Fig. 1 shows a lateral sectional view of a drain hose not used according to the invention in a known washing machine together with the tub flange and therefore has purely radially pronounced expansion folds. Fig. 2shows a side sectional view through a washing appliance according to the invention, wherein only the parts essential to the invention are shown. Fig. 3 shows a perspective front view of a drain hose used according to the invention with helical expansion folds in an expansion fold area and a tub flange in a water drainage system usable according to the invention. Fig. 4 shows a further perspective front view of a drain hose used according to the invention with helical expansion folds in an expansion fold area in a water drainage system usable according to the invention.

[0031] Fig. 1shows a side sectional view of a drain hose 9 not used according to the invention with a tub flange 4 in a known washing machine not shown otherwise. Five radial expansion folds 11 are arranged in the expansion fold area 10 to compensate for the tub vibration paths. The core diameter or the flow cross-section decreases along the flow direction (here from right to left from a tub (not shown) to a drain pump (not shown) of the washing machine, since the gas content of the two-phase flow medium (air-water or air-lye mixture) generally decreases toward the drain pump.

[0032] Fig. 2shows a side sectional view through a washing appliance 1 according to the invention, wherein only the parts essential to the invention are shown. In the tub 2, a drum 3 for holding laundry items not shown here is mounted so as to be rotatable about a horizontal axis of rotation 7. The large curved arrow indicates a possible direction of rotation. An aqueous liquid from the tub, generally a two-phase mixture of air and an aqueous liquid, flows from an opening arranged laterally in the lower part of the tub 2 via a tub flange 4 (long straight arrow) into a drain hose 5 which is provided with helical expansion folds 8, so that a circular helical flow, indicated by a small curved arrow, results in the direction of the drainage pump 6 or an access (intake nozzle) thereto.

[0033] Fig. 3shows a perspective front view of a drain hose 5 used according to the invention with helical expansion pleats 8 in an expansion pleat area 10 and a tub flange 4 in a water drainage system usable according to the invention. 12 denotes the inner area of ​​the drain hose. The outer diameter of the drain hose 5 decreases in the flow direction (here from top left to bottom right). The screw and spiral geometry of the drain hose expansion pleats is a right-hand thread for a washing drum rotation in the CCW direction.

[0034] Fig. 4shows a further perspective front view of a drain hose 5 used according to the invention with helical expansion pleats 8 in an expansion pleat area 10 and a tub flange 4 in a water drainage system usable according to the invention. 12 denotes the inner area of ​​the drain hose. The outer diameter of the drain hose 5 decreases in the flow direction (here from top right to bottom left). The outer diameter of the drain hose 5 decreases in the flow direction (here from top left to bottom right). The screw and spiral geometry of the drain hose expansion pleats here is a right-hand thread for a washing drum rotation in the CCW direction. List of reference symbols

[0035] 1 Washing machine; washing machine, washer-dryer 2 Soil container 3 Drum 4 Soil container flange 5 Drain hose 6 Drainage pump (soil pump, drainage pump) 7 Rotation axis 8 Helical expansion folds 9 Drain hose with radial expansion folds 10 Expansion fold area 11 Radial expansion fold 12 Flow channel part, core

Claims

1. Washing appliance (1), comprising a tub (2) and a drum (3) rotatably mounted therein about a rotation axis (7) for receiving laundry items, and a water drainage system (4, 5, 6) comprising a tub flange (4) in the tub (2), a drainage pump (6) and a drain hose (5, 7) arranged between the tub flange (4) and the drainage pump (6), characterized in that the drain hose (5) is equipped with helical expansion folds (8) at least in one expansion fold area (10).

2. Washing device (1) according to claim 1, characterized in that the expansion fold area (10) in the drain hose (5) extends from the drainage pump (6) to the tub flange (4).

3. Washing device (1) according to claim 1 or 2, characterized in that the drain hose (5) is arranged at an angle between the tub flange (4) and the drainage pump (6).

4. Washing device (1) according to one of claims 1 to 3, characterized in thatthe slopes of the helical expansion folds (8) are constant.

5. Washing device (1) according to one of claims 1 to 4, characterized in that the outer diameter d of the drain hose (5) decreases from the tub flange (4) to the drainage pump (6).

6. Washing device (1) according to one of claims 1 to 5, characterized in that the outer diameter of a flow channel part (12) in the drain hose (5) is the same or decreases over the length of the drain hose (5).

7. Washing device (1) according to one of claims 1 to 6, characterized in that the drainage pump (6) is a radial flow pump (centrifugal pump).

8. Method for operating a washing appliance (1), having a tub (2) and a drum (3) mounted therein so as to be rotatable about a rotation axis (7) for receiving items of laundry, and a water drainage system (4, 5, 6) comprising a tub flange (4) in the tub (2), a drainage pump (6) with an intake port and a pressure port, and a drain hose (5, 7) arranged between the tub flange (4) and the drainage pump (6), wherein the drain hose (5) is equipped with helical expansion folds (8) at least in one expansion fold region (10), and wherein the method comprises the step in a drainage phase of rotating the drum clockwise or counterclockwise, depending on whether the expansion fold geometry represents a left-hand or right-hand thread.

9. Method according to claim 8, characterized in thatthe expansion fold geometry of the drain hose (5) represents a left-hand thread and the drum (3) is rotated clockwise during the drainage phase.

10. Method according to claim 8, characterized in that the expansion fold geometry of the exhaust air hose (5) represents a right-hand thread and the drum (3) is rotated counterclockwise during the drainage phase.

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