The present invention pertains to a method for self-testing and checking certain functions of a cooking device in the form of a convection oven, a steamer, or a combination of the two, namely a convection steamer, which comprises a cooking chamber or compartment, which can be closed by a cooking compartment door, and a plurality of actuators such as pumps, at least one heating device, at least one steam injection device, at least one flow-generating device such as a blower, and flaps and/or valves as well as temperature sensors and an appliance control unit.
Modern cooking appliances are highly sophisticated devices with a large number of individual components, some of which are subject to a certain amount of wear as a result of the frequent loads to which they are subjected; these loads have multiple causes, one of which is the high temperatures at which the device operates. A large number of malfunctions can therefore occur, which make it more difficult or even impossible to obtain the desired cooking result.
It is possible in principle to monitor certain appliance functions by means of complicated sensors. Thus, for example, the operation of the blower wheel can be monitored by appropriate monitoring of the blower motor by the use of Hall sensors, for example. The operation of pumps such as the drain pump can be monitored by using pressure sensors, for example, or by measuring the flow rate, or by measuring the current drawn by the pump. The sensors and control units required for this purpose are disadvantageous. Not only are they complicated and thus expensive, but the sensors themselves are also at risk of malfunction and failure, so that it cannot always determined whether the assembly responsible for the appliance function is itself defective or whether it is the monitoring sensor which is defective.
In particular, problems can also occur it the context of customer service visits, specifically in low-density population areas. The major problem is often that, because the operating personnel are becoming increasingly less knowledgeable, the appliance defect in question can no longer be identified, and when the call goes out to customer service, the customer cannot tell the service representative what spare parts he should bring with him When the customer service representative then arrives and is obliged to observe that he does not have the required spare part, he must often make an extra trip back and forth, often over quite a long distance.
An object of the present invention is therefore to propose a self-testing method which does not require additional sensors to check the functioning of the actuators of the cooking appliance, and which, after the test has been run automatically, makes it possible to determine whether any of the actuators is defective, and, if so, which one(s), so that effective maintenance procedures can be carried out and/or certain actuator malfunctions can be determined or ruled out. This object is achieved by the features of claim 1.
The method according to the invention for self-testing and checking certain functions of a cooking appliance in the form of a convection oven, a steamer, or a combination of the two, namely a convection steamer, is characterized in that, by means of the temperature sensors of the cooking appliance, the functionality of the actuators of the cooking appliance can be checked by comparing the detected temperatures and temperature profiles with the reference temperature values and reference temperature profiles which are to be expected during operation of the actuator in question and which are stored in the electronic appliance control unit; and in that, if the detected value agrees with the corresponding reference value, the electronic appliance control unit concludes that the actuator in question is functioning properly, or, if a deviation is detected, that it is malfunctioning and displays, stores, and/or transmits the results for evaluation, wherein, at the beginning of each detection, the cooking appliance is in a defined initial state.
By means of the temperature measurements, which can be conducted by the temperature sensors installed in the cooking appliance, certain actuators are checked to determine their functionality. A basic principle of the self-testing method according to the invention is the evaluation of certain rates of temperature change. The evaluation is dependent on, for example, the size of the cooking appliance, on the type of energy and voltage, or on the type of gas. There are therefore certain limit values associated with the specific appliance. As a result of the temperature measurements, therefore, appliance defects can be confirmed or ruled out. By isolating the malfunction of the cooking appliance and identifying the individual components responsible, it is possible in particular to improve customer service efficiency.
Thus, within the scope of the present invention, all essential appliance components can be checked in the simplest possible way. The great advantage of the present invention also consists in that, to implement the self-testing, no additional sensors need to be installed in the cooking appliance; on the contrary, the temperature sensors necessary for the cooking programs in question and for the operation of the cooking appliance are themselves sufficient to carry out the various individual self-testing steps.
It is advantageous, furthermore, for at least two actuators to be checked in succession, and for the defined starting state of the at least second actuator test to be produced essentially by the preceding actuator test. Thus several actuators can be self-tested one after the other in correspondingly rapid sequence.
It can be provided, if desired, that the following actuator cannot be tested if the preceding actuator has failed its test, in which case the entire test procedure thus comes to a stop. This prevents false test results from being obtained, and there is no danger that a properly operating actuator is judged to be defective.
It is especially advantageous, furthermore, for the self-test to comprise a check of the oven/steamer compartment environment (temperature/humidity) control and/or the cleaning of the cooking appliance. This can be done either in different self-tests or in a one complete self-test.
Within the scope of the self-test, it is advantageous for it to be possible to check at least one of the following actuators of the cooking appliance: the heating device, the temperature controller, the steam generation, the dehumidifier, the recirculation pump, and drain pump for draining a liquid reservoir.
It is advantageous to determine the functionality of the heating device by heating the cooking compartment over a specific temperature range within a predetermined time interval.
In the case of cooking appliances with direct water injection, it is advantageous to determine the functionality of the steam generation by heating the cooking compartment to a predetermined temperature and then to detect the drop in temperature during the active steam generation. The steam generation test can thus be carried out immediately after the test of the heating device. In the case of cooking appliances which comprise an additional steam generator, the test can be carried out by detecting the increase in the temperature of the cold cooking compartment caused by the injection of 100° C. steam.
It is advantageous, furthermore, to determine the functionality of the dehumidification by a dehumidifier by heating the cooking compartment and then, after opening the dehumidifier, to detect the temperature measured by a sensor thermally coupled to the dehumidifier, preferably a sensor in a feed air pipe, which temperature should drop by a predetermined amount within a predetermined time interval. As a function of the appliance in question, it may be possible to use the cooking compartment temperature sensor for this test, if it is sufficiently well-coupled thermally to the dehumidifier. Dehumidification can be achieved by supplying outside air or by injecting water, i.e., by quenching the steam atmosphere.
It is advantageous, furthermore, to determine the functionality of the recirculation pump by heating the cooking compartment and, after activating the recirculation pump, by detecting the cooking compartment temperature, which should fall by a predetermined amount in a predetermined time interval. Thus here is no longer any need to detect the operation of the recirculation pump directly by means of appropriate sensors, as described above.
It is advantageous, furthermore, to determine the functionality of the drain pump by first filling the liquid reservoir and starting the recirculation pump, then by turning the drain pump on and heating the cooking appliance in convection mode. A temperature considerably greater than 100° C. should be measured after a predetermined time interval. The relationships are as follows: While the recirculation pump is running, the cooking compartment is cooled by the water being continuously pumped through the cooking compartment. As long as this circuit is operating, the temperature in the cooking compartment cannot rise much above 100° C. even at the maximum heat setting.
This water circuit is interrupted when a properly functioning drain pump is turned on. The liquid reservoir of the recirculation pump is emptied. The recirculation pump runs on empty and cannot pump any water into the cooking compartment. Without this supply of water, the cooking compartment can now heat up to the set nominal temperature of greater than 100° C.
It is advantageous, furthermore, for the self-testing method according to the invention to determine whether the door seal is providing a satisfactory sealing effect; this can be done by first heating the cooking compartment to a predetermined temperature and then, after making sure that the door is closed, turning off the heating device and the actuators and detecting the temperature drop. If the door seal is completely functional, the temperature will drop only slightly, whereas, if the door seal is defective, a correspondingly greater temperature drop will be detected.
The present invention is not limited to the situation in which an operating cooking appliance can be tested for functionality by the self-testing method according to the invention. The self-testing method according to the invention is also adapted, according to the invention, to the self-testing of a new appliance. This facilitates the final inspection of the new appliance before delivery to the intended customer. In addition, a calibration of the reference values can be carried out under standardized conditions when they are stored for the first time.
In particular, it is advantageous, according to the present invention, for the detected values to be stored in a values table for later checking Deviations can then be identified accordingly on the basis of this values table.
The method according to the invention can be advantageously initiated by a wired or a wireless connection to the cooking device.
It is a particular advantage of the present invention that the individual self-tests run essentially automatically, and that their results are automatically displayed and possibly transmitted and/or stored as data.
It is preferable to conduct the test during the night, when the cooking appliance is not being used. The user can also be instructed to perform the necessary preparations such as not to leave any cooking racks in the cooking compartment at the end of work on the preceding day.
The present invention also comprises a cooking appliance in the form of a convection oven, a steamer, or a combination of the two, namely, a convection steamer, with a cooking compartment, which can be closed by a cooking compartment door, and a plurality of actuators such as pumps, at least one heating device, at least one steam injection/generation device, at least one flow-generating device, and flaps and/or valves as well as temperature sensors and an electronic appliance control unit, wherein this cooking appliance is adapted to, and capable of, performing a self-testing method according to one of claims 1-14.
Additional details, features, and advantages of the present invention can be derived from the following description of the exemplary embodiments illustrated in the attached drawings:
In front cover wall 5 there is a display and control panel 17, which is configured in the form of a touchscreen. An input signal to the appliance control unit can be transmitted by direct contact with certain fields.
The subdivision of the display and control panel 17 is illustrated in more detail in
Above the touchscreen 61 there is provided a panel 62 with a single row, on the left of which a loudspeaker 64 is provided, which is covered by a decorative foil and therefore cannot be seen on the appliance. On the right is provided an on/off button 66 for the cooking appliance 1, preferably also touch-sensitive. Under the touchscreen 61 another decorative surface 68 is provided, which, if desired, can also be configured as an additional display and control panel.
For the sake of clarity, the cooking compartment door has been removed in
As can be seen in
Blower wheel 29 is driven by a blower wheel motor 41, the speed and direction of which can be controlled.
In the lower area of the technical space a vapors temperature sensor 43 and a pipe 45 for quenching the vapors are provided. A vapors quenching valve 47 is present, which is connected to the vapors quenching pipe 45 by a hose (not shown).
A recirculation pump 49 and a drain pump (“siphon pump”) 51 are also provided. The recirculation pump serves to circulate cleaning liquid, whereas drain pump 51 serves to empty the liquid reservoir (not shown), located underneath the cooking compartment.
In the following, the individual components of the self-testing method according to the invention are described. The starting point of the self-testing method is a defined initial state of the cooking appliance, i.e., the state which is present when the self-testing method is begun.
As previously mentioned, the self-testing method is characterized in particular in that temperature measurements can be made by the temperature sensors already installed in the cooking appliance, as a result of which the functionality of specific actuators can be checked. The self-testing method according to the invention is based on the principle of evaluating specific rates of temperature change. For this purpose, reference is made to
The expected temperature drop during active dehumidification is illustrated by curve 58, corresponding to −15 degrees Kelvin in 60 seconds, for example.
The fastest temperature drop is expected when the recirculation pump is running, namely, a drop of −15 degrees Kelvin in 30 seconds according to curve 59. If the drain pump is active and the recirculation pump is also running, however, the normal change in temperature shown by curve 56 is expected. In the case of a defect, namely, a defective drain pump, the temperature would change in the manner shown by curve 59.
The evaluation depends, among other things, on the size of the appliance, on the type of energy and type of voltage, or on the type of gas. Thus appliance-dependent limit values are obtained. The temperature measurements are intended to confirm or rule out appliance defects.
It is advantageous for the self-testing method to be used as part of the final inspection of the appliance before it is delivered to the customer. This situation will be referred to first.
The self-testing method of the present invention comprises two areas; the compartment internal climate (temperature/humidity) control of the cooking appliance and the cleaning of the cooking appliance.
The advantageous possibility is available to conduct the two tests either separately or together as a complete test. The complete test saves a corresponding amount of time, wherein the climate (temperature/humidity) test can be conducted without the need for any further preparation. In contrast, when a complete test is to be run or when only the cleaning test is to be run, it is necessary to make certain preparations first.
The following actuators can be evaluated by the self-testing method:
I. Climate (temperature/humidity) control:
II. Cleaning:
The self-testing method according to the invention is limited to the actuators which are not automatically checked during normal operation. These actuators are:
It is advantageous for the self-testing method to be turned off on the basis of a certain parameter; this corresponds to a blocking of certain users from conducting the self-testing method, depending on the concrete application desired. The self-testing method can thus be reserved solely for remote diagnosis. All times and temperatures are to be taken from an Excel table, which is stored in internal memory or in an XML file. According to present invention, the following table is obtained by way of example:
If an appliance is tested for which no values have yet been defined, the self-test can be started in a special mode. For this purpose, the selection is displayed accordingly on the display panel 17, as shown in
Climate (temperature/humidity) test:
Cleaning test:
The expected values for the specific appliance in question are stored in a file (e.g., an XML file), which is automatically overwritten during the execution of learn mode. Thus even customized machines can be easily provided with the expected values. This file is not overwritten when an update occurs.
If, at the start of the self-test, the appliance-specific file is not yet present, the corresponding values are read from the central file and written to the appliance-specific file. In the central file, the values are stored for all current models and can be selected automatically on the basis of the combination of appliance model and type of heating device. It is possible for this file to be overwritten when an update occurs.
The test sequence is described below. Cooking appliance 1 is in a starting state:
The appliance can be tested completely in about 25 minutes by the automatic test procedure. The results and the date of the most recent preceding self-test are displayed. Alternatively, the test can be started over a network connection (ethernet, see below). The test of the door, i.e., of the door's reed contact, must be carried out beforehand.
After the test has been started, the appliance first checks to determine whether the following temperatures are under 50° C.: cooking compartment temperature, core temperature sensor, possibly the humidity sensor. If this temperature is exceeded, the test program is stopped, and the error message “appliance too hot” is displayed. If the temperatures are in the desired range, the test begins.
The appliance is preferably operated at all times so that the blower turns only in one direction (e.g., always toward the right) and at the “fast” speed setting. All of the tests proceed in sequence. As shown in
Most of the tests should be conducted in “convection mode”, because this advantageously prevents steam from being injected, which would falsify the test results.
The cooking appliance shown in
Door 7 must be closed before the self-test can begin. If door 7 is not closed, the test will not start, because if it is open it is impossible to detect a defect in the door contact reliably. Instead, a message is shown, as can be seen in
After door 7 has been closed, the display according to
The test of door 7 contact lasts until the signal “door closed” has been received for at least two seconds. This ensures that the door is properly latched. The present invention proposes that, if the door is not opened and closed again within the predetermined period, it is concluded that the door contact has failed the test. The complete self-test is terminated, and the corresponding results are displayed.
To conduct the individual actuator tests, it is necessary to prepare the cooking appliance, i.e., to establish a predefined initial state, as shown in field 69 of
The Complete Test now begins in step 3, as can be seen in
The test can thus reliably determine whether or not:
Then, as part of the climate (temperature/humidity) test, the self-testing method continues with the test of the steam generator/injector, as shown in
To test the dehumidifier, as shown in
The test of the feed air flap concludes the climate (temperature/humidity) test.
The cleaning test can now be carried out immediately thereafter, or, as previously mentioned, it can also be carried out separately.
As shown in
Then the test of the steam valve, i.e., of the steam/vapors quenching valve 47, is carried out, as shown in
In the cleaning test, the next step is the testing of the siphon or drain pump 51. First, the drain pump 51 is turned on for about 20 seconds to empty the liquid reservoir. Then the cooking appliance is operated for about 2 minutes 30 seconds at 130° C. in convection mode, wherein the blower wheel 29 is operated continuously toward the right. The recirculation pump 49 is turned on during the heating phase. Within the operating time in convection mode, the appliance must reach a cooking compartment temperature of 130° C. +10 K/−5 K. If this not reached, the drain pump 51 is defective. The reason for this is that, while liquid is being circulated, it is not possible for the temperature in the cooking compartment to rise much above 100° C. (temperature at which water evaporates). An increase does not occur until after the water has evaporated; that is, until after the drain pump 51 has emptied the liquid reservoir. The liquid reservoir is now filled up again, which is done by first turning off the recirculation pump 49 and only then turning on the steam/vapors quenching valve 47 for essentially 20 seconds. In the case of higher-power appliances, the test is carried out at reduced power to avoid evaporating the water completely.
If necessary, the temperature controller can be tested again as shown in
The tolerances given above are cited merely as examples and can be different within the scope of the invention.
Fields 65 and 69 of
If, however, it has been discovered that a test was failed, as, for example, the test of recirculation pump 49, then, as shown in
The following table shows the dependence of the malfunctions of the individual components on other components.
The functionality test of blower 29 can be checked on the basis of, for example, significant temperature differences in the cooking compartment. For example, this can be done by comparing the measurement values of cooking compartment sensor 35 with those of the core temperature sensor (not shown). If the door contact or the heater are not working properly, the test is stopped, because the other tests will not work.
If the test of recirculation pump 49 is negative, the result for steam injection valve 47 and drain pump 51 will not be evaluated, or these two tests will not be performed. A record will be kept, however, of the test result.
According to the present invention, the self-testing procedure can be started in the form of a remote diagnosis. For this purpose, a wired or wireless connection to the cooking appliance can be used. In particular, this self-test can be initiated over an ethernet connection. For this purpose, for example, the protocol for the kitchen process control system can be used. By means of an additional command and an action number, the self-test can be started, stopped, or evaluated.
With the present invention, the possibility of self-testing a cooking appliance in the form of a convection oven, a steamer, or a combination of the two, namely, convection steamer, is created, which takes place essentially automatically and by means of which all of the essential actuators of the cooking appliance can be automatically checked in a short time, as a result of which the functionality of the cooking appliance can be displayed to the operating personnel and/or any malfunctions and defects can also be displayed. There also exists the possibility—especially relevant to customer service personnel—to gain remote access to the appliance, which may be installed a considerable distance away, and to learn from the self-test which components of the cooking appliance are possibly defective. This helps them to provide the necessary spare parts in an efficient manner.
The self-testing methods can also be used to test new appliances and to calibrate them, which prevents partially defective appliances from being delivered to customers.
The present invention is not limited to the exemplary embodiments described here In particular, the numerical values which are cited are given only by way of example, and deviations from them are also within the scope of the invention.
Number | Date | Country | Kind |
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13188594.9 | Oct 2013 | EP | regional |
The present application is a U.S. national phase entry of pending International Patent Application No. PCT/EP2014/071945, international filing date Oct. 14, 2014, which claims priority to European Patent Application No. EP 13 188 594.9, filed Oct. 14, 2013, the contents of which are incorporated by reference in their entireties.
Filing Document | Filing Date | Country | Kind |
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PCT/EP2014/071945 | 10/14/2014 | WO | 00 |