Method for detecting a hardware error and cooking appliance for carrying out the method

Abstract

Method for detecting a hardware error when closing a cooking chamber of a cooking appliance and for issuing a notice about a detected hardware error, comprising the following steps: Determining and storing at least one reference value for the time period for the humidity increase in the cooking chamber from a first humidity value F1 to a second humidity value F2 at a predetermined value for the temperature of the atmosphere in the cooking chamber and with the cooking chamber closed; Recording at least one measured value for the time period for the humidity increase in the cooking chamber from the first humidity value F1 to the second humidity value F2 at the predetermined value for the temperature of the atmosphere in the cooking chamber and with the cooking chamber closed; Comparing the measured value with the reference value and outputting an indication from a plurality of indications via at least one output device depending on the deviation of the measured value from the reference value, wherein • the detected hardware errors concern the function of a fan flap that is connected to the cooking chamber and / or a door that closes the cooking chamber or a lid that closes the cooking chamber, and • the notices represent instructions and / or warning signals concerning the ventilator flap and / or the door or the lid.

Description

The present invention relates to a method for detecting a hardware fault when closing a cooking chamber of a cooking appliance and for outputting an indication of a detected hardware fault.For example, U.S. Pat. No. 5,711,606 discloses a diagnostic system for a cooking appliance having a heating device, in which the temperature of the heating device is detected via a temperature sensor in order to record a temperature profile over a specific period of time, which is compared with stored temperature profiles which are associated with specific malfunctions in order to detect a specific malfunction of the heating device. As soon as such a malfunction has been detected, an operator of the cooking appliance can receive a corresponding notification.DE 10 2008 008 020 A1 discloses a method for identifying fault events in a cooking appliance having at least one nozzle for injecting at least one fluid into a cooking chamber of the cooking appliance, in which method, after a nozzle activity, at least one temperature value and / or one humidity value is detected and compared with a specific setpoint value. Thus, two checks of the condition of a nozzle are made.DE 10 2005 017 617 A1 relates to a method for temperature control of a furnace, in particular a kitchen oven, for achieving a predetermined temperature by heating during a required heating time on the basis of a control program, wherein the control program is formed from a basic control program, which is generally predetermined for a furnace type, by computational consideration of a static correction variable, which reflects individual furnace parameters, and / or a dynamic correction variable, which takes into account variable operating parameters of the furnace. The static correction variable is determined during a heating process on the empty furnace by comparing a measured actual heating time value with a heating time reference value corresponding to the basic control program.A method for monitoring a cooking appliance which has temperature-sensitive components is known from DE 10 2011 015 834 A1, wherein at least one temperature sensor is used, the profile of the temperature detected by the temperature sensor is derived after time, the slope of the temperature profile determined in this way is compared with a predetermined threshold value and, if the predetermined threshold value is exceeded, an error signal is generated. An air filter is provided and the threshold value lies above the slope values which result during operation with a soiled air filter.DE 10 2010 002 877 A1 describes a method for operating a household appliance having at least two electrical consumers, wherein the function of at least one of the electrical consumers is checked by means of a control device of the household appliance, and after finding a fault of the checked electrical consumer, fault information is generated by the control device, by means of which fault information the faulty electrical consumer is unambiguously designated.A fan flap is required for gas exchange in a cooking chamber of a cooking appliance. Depending on the useful life and environmental parameters, in particular determined by dirt particles in the ambient air of the cooking appliance, dirt can settle on the fan flap, so that it no longer satisfactorily fulfils its sealing function. An leaking fan flap ensures a constant intake of ambient air into a cooking chamber, which leads to an extension of a heating time and, in the worst case, a non-reaching of a desired heating temperature. Leakage, caused by a soiled fan flap, can also lead to a desired setpoint humidity being able to be reached in a cooking chamber in a delayed manner or even no longer at all. Such a malfunction can be corrected, for example, by cleaning the fan flap.Leakage of a cooking chamber can also occur as a result of contamination or wear of the seal of a door or of a cover for closing the cooking chamber.It is therefore an object of the present invention to provide a method for detecting a hardware fault when closing a cooking chamber of a cooking appliance and for outputting an indication of a detected hardware fault.This object is achieved according to the invention by a process according to claim 1.Furthermore, the invention provides a cooking appliance having a cooking chamber which can be closed by a door or a cover and can be ventilated with ambient atmosphere by means of a fan flap, a device for supplying hot air, steam and / or microwaves to items to be cooked in the cooking chamber, optionally under pressure, an input device, an output device, a storage device, a measurement device for detecting the temperature and / or the moisture in the cooking chamber, and a control or regulating device which is connected to the device for supplying the input device, the output device, the storage device and the measurement device and is configured to carry out a method according to the invention.It can be provided here that the output device comprises the first and the second output device at least temporarily, and / or the output device comprises a display device and / or an audio device, and / or the storage device can be detached from the cooking appliance at least temporarily.Thus, when a cooking appliance is first put into operation, for example in the form of a cooking appliance for supplying items to be cooked with hot air and / or steam, as in a self-cooking center of the applicant, a reference curve for the course of the temperature over time can be recorded. The reference curve can contain, for example, information about the time period required to heat the atmosphere in a cooking chamber to the boiling temperature at 50° C. and steam. The reference curve can alternatively be created by a manufacturer's measurement, after maintenance, by means of several measurements and averaging or other methods within the skill of a person skilled in the art.The time durations acquired when the reference curve is recorded can (can) be compared later with correspondingly acquired time duration(s). Depending on the deviation of the respective measured value from the corresponding reference value, according to the invention, different indications can be displayed on a display display of the cooking appliance. The corresponding display can depend on the time period in which a specific deviation is detected and / or the frequency of a detected deviation. The following table gives an exemplary overview concerning a leakage caused by a fan flap, which has an effect on the time duration of the heating of the atmosphere in a cooking chamber in a preheating step before cooking to a predefined setpoint value, together with selected indications on a display display:0-10 % [0-30 sec]no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no nono no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no nono no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no10-15 % [30-45 sec]7 DaysA constant increase in the heating time over a set value of 7 days is achievedPlease check fan flap (appears from day 7)15-30 % [45-90 sec.]3 DaysConstant increase of the heating time, setpoint value, is achievedPlease check fan flap (appears from day 3)30-45% [60-90 sec]1 Day DaySuddenly increasing heating time, set point, is reachedPlease check (appears immediately) fan flap30-45% [60-90 sec]1 Day DaySuddenly increasing heating time, set point is not reached (max 70%)Please service call Check Cooking Result!30-45% [60-90 sec]1 Day DaySuddenly increasing heating time, set point is not reached (0-30%)Please service does not call No. Prog abort10-15 % [30-45 sec]60 DaysA constant increase in the cooking time over a 60 day set point is achievedPlease check fan flap only appears in the service technician mode)10-15 % [30-45 sec]60 DaysA constant increase in the cooking time over a 60 day set point is achieved. But 4 individual days with a time increase of once 15% on the dayPlease check fan flap (appears from the 4th single day)A plurality of indicators can be derived from the table, wherein, depending on the situation, only one indicator is selected for display at a time from this plurality.When determining or better selecting the indication displayed on the display screen, malfunctions of other functional units of the cooking appliance than the fan flap are not taken into account in the temperature detection. For example, there may be a low water pressure, which may be an indication of the need to refill a tank of a steam generator and may result in a predetermined desired humidity value not being reached. Also, calcification of the steam generator or a power failure may result in a target temperature value not being reached. All these errors can be detected by further sensor systems of the cooking appliance and taken into account in the selection of the indication to be displayed.The respective notification to be displayed can be selected from a plurality of previously stored notifications, wherein the deposit can be made by the manufacturer. Of course, further indications can be added by an operator during the operation of the cooking appliance.Further features and advantages of the invention will become apparent from the following description of an exemplary embodiment. In this case, the drawing, which consists of a single figure, shows the course of the moisture rise in the cooking chamber of a cooking appliance during a preheating step, that is to say without loading the cooking chamber with items to be cooked.The figure shows a setpoint value of the moisture of 100%, and also a reference curve for the moisture increase (F IS 1) during preheating, which curve represents a normal profile, that is to say a profile for a fully intact and thus clean fan flap. In addition, three moisture rises can be seen from the FIGURE, which deviate clearly from the reference curve, namely due to different errors.Directly below the reference curve, a slightly delayed moisture increase (F IS 2) can be observed, which reaches the setpoint value of the moisture not after 3 min and 40 sec as the reference curve, but only after 4 min and 20 sec. The reason for the corresponding delay can be a slight leakage of the fan flap. If a corresponding course is detected multiple times, for example four consecutive times, it can be displayed on a display device of the cooking appliance that the fan flap is to be tested pleasely.Furthermore, two moisture rises are shown in the figure, in which the desired value is not reached. Firstly, the moisture after 5 min is only 45% (F IS 3), which is a clear indication of a leak in the cap and can, for example, cause the indication that please call a service person. On the other hand, the moisture after 5 min is less than 20% (F IS 4) and can consequently have, for example, the indication that the preheating process is interrupted and maintenance has to take place immediately appears on the display display.Early detection of contamination of a fan flap and / or also of a defective door or cover seal reduces the risk of non-cooked foods, which can lead to a hygiene risk and ultimately to a health risk. In addition, this premature detection makes it possible to avoid unnecessary energy consumption, since cooking devices with a leak have an energy loss due to the need for longer heating times.The features disclosed in the preceding description, the claims and the drawing can be essential both individually and in any combination for the realization of the invention in its various embodiments.

Claims

Method for detecting a hardware fault during the closing of a cooking chamber of a cooking appliance and for outputting an indication of a detected hardware fault, having the following steps: determining and storing at least one reference value for the time duration for the moisture rise in the cooking chamber from a first moisture value F1 to a second moisture value F2 at a predefined value for the temperature of the atmosphere in the cooking chamber and the closed cooking chamber; detecting at least one measured value for the time duration for the moisture rise in the cooking chamber from the first moisture value F1 to the second moisture value F2 at the predefined value for the temperature of the atmosphere in the cooking chamber and the closed cooking chamber; comparing the measured value with the reference value and outputting an indication from a plurality of indications via at least one output device as a function of the deviation of the measured value from the reference value, wherein • the detected errors of the hardware relate to errors of the function of a fan flap operatively connected to the cooking chamber and / or of a door closing the cooking chamber or of a cover closing the cooking chamber, and • the indications represent action instructions and / or warning signals relating to the fan flap and / or the door or the cover.Method according to claim 1, characterised by determining and storing at least one further reference value for the time duration for heating the atmosphere in the cooking chamber from a first temperature value T1 to a second temperature value T2 at a predetermined value for the moisture in the cooking chamber and closed cooking chamber; acquiring at least one further measurement value for the time duration for heating the atmosphere in the cooking chamber from the first temperature value T1 to the second temperature value T2 at the predetermined value for the moisture in the cooking chamber and closed cooking chamber; Comparing the further measured value with the further reference value and outputting a further indication from a plurality of further indications via at least one further output device as a function of the deviation of the further measured value from the further reference value, wherein • the detected errors of the hardware relate to errors of the function of the fan flap operatively connected to the cooking chamber and / or of the door closing the cooking chamber or of the cover closing the cooking chamber, and • the further indications represent action instructions and / or warning signals relating to the fan flap and / or the door or the cover.Method according to Claim 1 or 2, characterized in that the reference value and / or the further reference value is determined during calibration or a first startup of the cooking appliance.Method according to one of the preceding claims, characterized in that a plurality of the reference values is determined as a function of time, a plurality of the measured values is recorded as a function of time and the plurality of measured values is compared with the plurality of reference values, and / or a plurality of the further reference values is determined as a function of time, a plurality of the further measured values is recorded as a function of time and the plurality of further measured values is compared with the plurality of further reference values.Method according to one of the preceding claims, characterized in that the circulation of the atmosphere in the cooking chamber is predefined when determining each reference value and when acquiring each measured value.Method according to one of the preceding claims, characterized in that, when outputting each indication, - malfunctions of functional devices of the cooking appliance which are not responsible for closing the cooking chamber, such as malfunctions of a heating device and / or of a steam generator, and / or - a time specification, such as a time period over which the comparison produces deviations of the measured values from the reference values, and / or - a frequency with which the comparison produces deviations of the measured values from the reference values, and / or - a loading state of the cooking chamber and / or - the length of the operation of the cooking appliance, in particular since the last maintenance of the cooking appliance, is or are taken into account.Method according to one of the preceding claims, characterized in that the plurality of indications is stored in a storage device, preferably before the first startup, and / or can be supplemented and / or changed during the operation of the cooking appliance.Cooking appliance having a cooking chamber which can be closed by a door or a cover and can be ventilated with ambient atmosphere by means of a fan flap, a device for subjecting items to be cooked in the cooking chamber to hot air, steam and / or microwaves, optionally under pressure, an input device, an output device, a storage device, a measurement device for detecting the temperature and / or the humidity in the cooking chamber, and a control or regulating device which is connected to the device for applying, the input device, the output device, the storage device and the measurement device and is configured to carry out a method according to one of the preceding claims.Cooking appliance according to claim 8, characterised in that the output device comprises the further output device at least temporarily, and / or the output device comprises a display device and / or an audio device, and / or the storage device is at least temporarily detachable from the cooking appliance.

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