DE102012112199A1 - Laundry treatment machine i.e. tumble dryer, has acceleration sensor provided with control unit to sense rotation of drum, defined position of drum and inclination of drum into standing position - Google Patents

Abstract

The machine (1) has a drum (2) rotatably mounted in a housing for receiving a laundry. An electric drive motor (3) drives the drum with a program control for selection and control of the program sequence of the machine. A control unit (8) controls the rotation of the drum by the drive motor. The drum is provided with an acceleration sensor (6). The sensor with the control unit senses the rotation of the drum, a defined position of the drum and an inclination of the drum into the standing position, so that the properties of the drum is considered in the control process of the machine.

Description

The invention relates to a laundry treatment machine, in particular a tumble dryer, with a drum rotatably mounted in the housing for receiving the laundry to be treated, with an electric drive motor for driving the drum, with a program control for selecting and controlling the program flow of the laundry treatment machine and with a control device for controlling the rotational movement of the drum by the drive motor.

Laundry treatment machines, especially dryers of the aforementioned type have long been well known and are now offered on a technically sophisticated state of the art on the market. In recent years, the process flows have been further developed through the introduction of new sensors and control methods that have improved the performance characteristics, the energy efficiency and the functionalities of these household appliances. However, in recent years there have been only a few new developments in the field of sensor technology and control technology, in which a defined position monitoring of the laundry drum forms the basis of the control process.

For example, it has been known for a long time in the washing machines to be loaded from above, in the so-called toploaders ( DE 40 37 868 A1 ), to move the drum to a position at the end of the washing program in which the drum opening to remove the laundry is at the top. As can be seen by way of example from this prior publication, magnetic, optical or inductive sensors or even tachogenerators have hitherto been used in laundry treatment machines for rotational movement or position monitoring of the laundry drum.

The disadvantage with these well-known monitoring devices is in particular that two-part sensors are necessary here, which must be aligned with one another and wherein one part must be provided on the rotating drum and the other part on the stationary housing or on another part of the system. This leads to a complex construction and a difficult mounting situation. In addition, this usually gives only information, whether the drum rotates or not. Although simple and cost-effective solutions can be implemented, this limits the expansion of new functionalities and applications if a defined and exact position determination of the drum must be recorded as a prerequisite.

The invention thus raises the problem for a laundry treatment machine of the type mentioned, to provide a further developed rotary motion and position control, in particular for a tumble dryer, can be realized with the novel applications and functionalities.

According to the invention, this problem is solved by a laundry treatment machine, in particular by a tumble dryer having the features of patent claim 1. Advantageous embodiments and further developments of the invention will become apparent from the following subclaims.

The invention is based in its approach on the idea of known from the prior art from other applications acceleration sensors z. B. use in a tumble dryer in a modified form, so as to open up new useful and function-improving control options.

The invention is so far oriented to introduce a new advantageous use of acceleration sensors in the field of household appliances, especially for laundry treatment machines.

Acceleration sensors are micro-electrical-mechanical systems (MEMS) and are offered not only for measuring acceleration but also for measuring angular acceleration in special applications. These acceleration sensors are small sensors that are now available on the market at low cost.

The use of acceleration sensors is already well known from the application in the automotive industry, in order to realize an impact detection for triggering the airbag in a car can. Another application is the use of PC's, laptop's u. s. w., in order to drive the read head in a safe position in time before the impact when falling of the device. Other applications include the detection of imbalances in devices of any kind. In the sensor technology for cameras u. Like. They are used to ensure automatic alignment of the image. Even in the now widespread iPads, they are used to align the screen display. In addition, acceleration sensors for controlling movements and tilt detection can be found in game consoles.

Furthermore, acceleration sensors belong to the prior art, which are also referred to as tilt sensors. With a tilt sensor, the exact position in relation to the direction of the solder or the change of the tilt angle be monitored. There are numerous methods for measuring inclinations with respect to the direction of the perpendicular given by gravity. The range of use of tilt sensors is z. Currently mainly in the field of accident prevention, for example on excavators and cranes as well as machine monitoring of industrial robots. The inclination sensors usually have a smaller measuring range and can therefore only be used within a limited range of reliable measured value acquisition.

In the DE 10 2005 037 144 B4 Although it has already been proposed to use an acceleration sensor in a drum washing machine in order to be able to sense vibrations of the swingably suspended drum assembly. It is provided to arrange the acceleration sensor directly on the board for the engine control. This control board is attached directly to the drive motor, so that it participates in the vibrations of the drum assembly.

The detection of imbalances in washing machines is relatively easy with an acceleration sensor possible, since in the case of an imbalance very high acceleration results, for the evaluation of an acceleration sensor is virtually predestined.

An acceleration sensor is thus used primarily in the obvious when it comes to detecting high acceleration values. However, since the drum moves relatively slowly and with low acceleration values in a laundry treatment machine during the washing or drying operation, the use of acceleration sensors in this rotary motion range has not received due attention.

The invention now starts from the consideration of selecting an acceleration sensor which is used in the manner of a tilt sensor. As a result, the sensor can be manufactured relatively inexpensively and is also suitable for a wide mass production. This tilt sensor is only interpreted for relatively slow rotational acceleration, since z. B. in the washing machine and also in the dryer during washing or drying, the drum is moved only at a low speed. In addition, in the applications according to the invention, only the measured values of two of the three possible axes, for example measured values of the Z and X axes, must be evaluated.

The advantages that can be achieved with the invention are summarized in that new multifunctional possibilities of use result from the special selection of an acceleration sensor and the arrangement of this sensor adapted to the respective system. Since only the acceleration of the fall must be evaluated, no additional, corresponding part is necessary for the operation of the acceleration sensor or of the inclination sensor.

The invention makes it possible to realize useful and versatile functions. Thus, the acceleration sensor for rotational movement monitoring can be used as overheating protection for a tumble dryer. It can thus be clearly determined whether the drum is spinning or not. This will certainly detect if the drive belt should be cracked or if the drive does not move the drum due to another blockage on the motor or drum bearing. This can cause the laundry to be damaged when the drum is stopped while the heating is switched on.

A particularly advantageous use results from the fact that a defined drum position is sensible. With the aid of an acceleration sensor arranged in the drum rib, a defined drum position can be approached reproducibly. This new functionality can be used to realize an interior lighting with lamps arranged in the drum rib. Care must be taken to ensure that the drum rib fitted with the lights always remains in the upper position at the end of the program or is moved there in a targeted manner.

In another application, an acceleration sensor for residual water detection can be used if z. B. the dryer is equipped with a humidifier. This serves to perform a finish treatment at the end of the drying process. This residual water can accumulate at the bottom of the drum at the end of the program. By way of a residual water sensor additionally integrated in the drum rib or in the vicinity of the drum rib, the still existing water can be detected. In this case, the drum rib with the residual water sensor must be positioned so that the residual water sensor is at the bottom. Depending on its measuring signals then appropriate measures can be taken to eliminate the residual water.

Finally, it is also possible to provide an acceleration lock with an inclined device in the laundry treatment machine with an acceleration sensor. Since in this case, the drum would be in an inclined position, the inclination sensor can sense this condition and this via a display device or activate a start-up lock until an alignment correction has been made. This prevents the possibility of bearing damage, faster wear or overall malfunction in certain drying programs.

An embodiment of the invention is shown purely schematically in the drawings and will be described in more detail below. It shows:

1 in a simplified representation of a tumble dryer with the necessary components for explaining the invention.

In the 1 is the application of an acceleration sensor preferably for a tumble dryer 1 shown. In the 1 are the drum 2 for receiving the laundry with their usual drive motor 3 and the drive belt 4 indicated schematically. In the present case has the drum 2 two opposite drum ribs 5 and 51 , as a driver in a known manner with rotating drum 2 cause the circulation of the laundry. Inside the upper drum rib 5 is an acceleration sensor 6 arranged, which has a fixed assignment to the drum rib 5 has, for example, that he is on a horizontal traverse 7 is attached. At the lower drum rib 51 is in the jacket area of the drum a residual water sensor 10 whose function will be discussed later. The residual water sensor may also be in another drum rib, for example the drum rib 5 be arranged. Then this rib has to be moved down to the position for the measurement. The advantage of the latter arrangement is that only one rib has to be equipped with electronic components. The acceleration sensor 6 and the residual water sensor 10 stand by signal with the control device 8th in connection. The control device 8th As is known, a microcontroller (MC) controls the measuring and control processes of the tumble dryer. The microcontroller can also be in the drum rib 5 be arranged and take on other tasks, for example, if the residual moisture control, a temperature control or lighting elements 9 in the drum rib 5 are integrated. In terms of control technology, synergy effects for the power supply in the drum rib can thereby be advantageously achieved 5 arranged components and for the signal transmission of the sensors use. In an advantageous embodiment, the acceleration sensor 6 together with the control device 8th arranged on a printed circuit board not shown here and is in a fixed relationship to the drum rib 5 , for example, in a horizontal arrangement within the drum rib 5 placed. Due to the fixed connection of the acceleration sensor 6 with the crossbar 7 or the control board will ensure that the accelerometer 6 always fixed in the same position and thus its signals are correctly interpretable. The acceleration sensor preferably used 6 has an evaluable signal range which corresponds to that of a so-called tilt sensor. In particular, acceleration sensors with a high sensitivity in a specific measuring range are suitable as a tilt sensor. It is sufficient to dimension this signal range so that the rotational movement of the drum and / or the current position of the drum and the horizontal inclination of the drum can be sensed via the detectable acceleration of the fall. The reproducibly measurable signal range of the acceleration sensor used as an inclination sensor is between +5.0 g and -5.0 g. In an advantageous embodiment, the measuring range may even be sufficient between +1.5 g and -1.5 g. By the use according to the invention of the acceleration sensor 6 in the drum rib 5 During operation, the alignment of two of the three measuring axes to the center of the earth constantly changes. By evaluating the signal from just two measuring axes, one can then determine the exact position of the drum rib on the drum track. This makes it possible for the signals of the acceleration sensor 6 by the control device 8th be evaluated such that by appropriate control of the drive motor 3 the laundry drum 2 can be moved to a defined drum position.

Below are a few examples for a tumble dryer with different uses of the acceleration sensor 6 and different functionalities:

Like in the 1 you can see the drum rib 5 of the tumble dryer 1 equipped with a lighting device, in this embodiment, a luminous element 9 in the bridge area of the upper drum rib 5 is shown symbolically. One or more light elements 9 can - as in 1 shown - in the horizontal web area of the upper drum rib 5 and / or on the oblique side surfaces of the drum rib 5 be arranged, which can be realized by reflection on the inner wall of the dryer, an indirect illumination. As light elements 9 are preferably used LED`s. When an efficient illumination of the interior of the laundry drum 2 must be done via the accelerometer 6 in connection with the control device 8th The drum can be turned into a position where the drum rib 5 in the upper vertex of the drum 5 located. Once the accelerometer 6 then signaling this position, the lighting can be switched on manually or automatically in connection with the door opening of the tumble dryer 1 be turned on. Since the lighting must be switched on only during a certain area with the upper position of the drum rib, it is sufficient here, only one of three possible axes, such as the Z-axis value of the acceleration sensor 6 to evaluate, since this value is directly dependent on the acceleration due to gravity. Release for the possible switching on of the illumination can already take place at values of -0.75 g to -1.25 g. Of course, the acceleration sensor can 6 also in a different drum rib than the light elements 9 In this case, he must assume a drum position in which the drum rib 5 with the light elements 9 lies in the upper vertex of the drum.

In another application, the acceleration sensor 6 be used for residual water detection when z. B. the dryer is equipped with a moistening device, not shown here.

The moistening device serves to be able to carry out a finish treatment for the purpose of smoothing the laundry items at the end of the drying process. This can be residual water at the end of the program at the bottom of the drum 2 accumulate. About one in the drum rib 5 or 51 or near the drum rib 5 or 51 additionally integrated residual water sensor 10 In this case, the remaining water can be detected.

In this case, the drum needs 2 be positioned so that drum rib 5 or 51 with the residual water sensor 10 located below, as is also in the 1 is shown by way of example. Depending on the measuring signals of the residual water sensor 10 then appropriate measures can be taken to eliminate the residual water.

Finally, it is also possible for the laundry treatment machine with an acceleration sensor 6 to provide a start-up lock at an inclination of the drum axis relative to the horizontal. In this case, it can be assumed that the device is wrong. As in this case also the drum rib 5 or 51 would be in an inclined position, the acceleration sensor 6 make this condition recognizable and can do so via a display device 11 or activate a startup lock in the system. By appropriate measures for readjustment, the system can then be brought into a balanced position.

If only this application variant is to be realized, it would also be conceivable to use the acceleration sensor 6 in an area outside the drum rib 5 to attach to the outer jacket of the drum and him over a corresponding line, or via contact elements with the in the drum rib 5 arranged to connect control board. Thus, also the already existing infrastructure of the drum rib can 5 regarding power supply and signal transmission.

The power supply for the accelerometer 6 as well as the signal transmission between the acceleration sensor 6 and one optionally outside the drum rib 5 located control device for the drive motor can over with the drum 2 connected sliding contacts, not shown here in detail. In order to keep the number of sliding contacts low, the supply current can be modulated depending on the signal in order to be able to distinguish the signals to be transmitted. The signal transmission can also be controlled by radio via corresponding transmitting and receiving modules.

Of course, the invention is suitable for understandable reasons primarily for a laundry treatment machine in the form of a tumble dryer 1 , Conceivable, however, would be comparable applications in a drum washing machine and a corresponding arrangement of an acceleration sensor 6 in the drum rib. The acceleration sensor 6 and possibly a part of its control device would then have to be waterproof encapsulated, however, since the drum rib inevitably moves through the washing water in a washing machine.

It should be obvious that the above-described embodiments do not represent the scope of the invention in its entirety, since with this new inventive concept, further obvious control processes can be realized.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 4037868 A1 [0003]
• DE 102005037144 B4 [0012]

Claims (15)

Laundry treating machine, in particular tumble dryer ( 1 ), with a rotatably mounted in the housing of the machine drum ( 2 ) for receiving the laundry to be treated, with an electric drive motor ( 3 ) for driving the drum ( 2 ), with a program control for the selection and control of the program sequence of the laundry treatment machine and with a control device ( 8th ) for controlling the rotational movement of the drum ( 2 ) by the drive motor ( 3 ), characterized in that the drum ( 2 ) with an acceleration sensor ( 6 ) in connection with the control device ( 8th ) the rotational movement of the drum ( 2 ) and / or a defined position of the drum ( 2 ) and or an inclination of the drum ( 2 ) in the stance position, so that these state properties of the laundry drum can be taken into account in the control process of the laundry treating machine. Laundry treating machine according to claim 1; characterized in that the acceleration sensor ( 6 ) has an evaluatable signal range which corresponds to that of an inclination sensor, wherein this signal range is dimensioned such that the rotational acceleration of the drum is determined by the detectable fall acceleration ( 2 ) and / or the current position of the drum ( 2 ) as well as the horizontal inclination of the drum ( 2 ) is sensible. Laundry treatment machine according to claim 2; characterized in that the measurable signal range of the acceleration sensor used ( 6 ) is between +5.0 g and -5.0 g. Laundry treating machine according to one or more of the preceding claims, characterized in that the acceleration sensor ( 6 ) in or on a drum rib ( 5 . 51 ) or on the outer peripheral shell of the drum ( 2 ) in the region of an underlying drum rib ( 5 . 51 ) is arranged. Laundry treating machine according to claim 4, characterized in that the acceleration sensor ( 6 ) so in the drum rib ( 5 . 51 ) or is mounted on a control board that a fixed assignment between acceleration sensor ( 6 ) and drum rib ( 5 . 51 ) consists. Laundry treating machine according to one or more of the preceding claims, characterized in that via the acceleration sensor ( 6 ) in connection with the control device ( 8th ) for the drive motor ( 3 ) A defined drum position can be controlled. Laundry treating machine according to one or more of the preceding claims, characterized in that via the acceleration sensor ( 6 ) in connection with the control device ( 8th ) the drum ( 2 ) is movable to a position in which a drum rib ( 5 ) in the upper vertex of the drum ( 2 ) is located. Laundry treating machine according to claim 7, characterized in that the drum rib ( 5 . 51 ) with bulbs ( 9 ) for illuminating the interior of the drum ( 2 ) is trained. Laundry treating machine according to one or more of the preceding claims, characterized in that via the acceleration sensor ( 6 ) in connection with the control device ( 8th ) the drum ( 2 ) is movable to a position in which a drum rib ( 5 . 51 ) is located at the bottom vertex. Laundry treating machine according to claim 9, characterized in that in the drum rib ( 5 . 51 ) a residual water sensor ( 10 ) is arranged, which senses the accumulating at the drum bottom liquid. Laundry treating machine according to one or more of the preceding claims, characterized in that the acceleration sensor ( 6 ) during operation of the laundry treatment machine for rotational movement monitoring of the drum ( 2 ) an unintended standstill of the drum ( 2 ) and via the control device ( 8th ) causes a warning and / or the interruption of the current program or the heating operation in the machine. Laundry treating machine according to one or more of the preceding claims, characterized in that via the acceleration sensor ( 6 ) in connection with the control device ( 8th ) a startup lock can be activated by the program control device if the acceleration sensor ( 6 ) senses an inclination of the drum axis relative to the horizontal. Laundry treating machine according to one or more of the preceding claims, characterized in that the power supply for the acceleration sensor ( 6 ) as well as the signal transmission between the acceleration sensor ( 6 ) and the control device ( 8th ) with the drum ( 2 ) occurs in connection sliding contacts. Laundry treating machine according to one or more of the preceding claims, characterized in that the signal transmission radio-controlled via transmitting and receiving modules. Laundry treating machine according to one or more of the preceding claims, characterized in that the acceleration sensor ( 6 ) to those in the drum rib ( 5 ) already existing power supply and signal transmission is coupled, for other measuring and control operations of the dryer ( 1 ) is provided.

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