EP3816517B1 - Cooking device controller with operating mode switch and timer - Google Patents

Description

The invention relates to a cooking appliance control system, having an operating mode switch which is designed to set a number of operating modes of a cooking appliance, and a timer which is designed to set a time-delayed start of an operating sequence under at least one of the operating modes which can be set using the operating mode switch. The invention also relates to a cooking appliance with such a cooking appliance control system. The invention further relates to a method for operating a cooking appliance. The invention is particularly advantageously applicable to ovens, in particular baking ovens.

Electronic oven controls or electronic clocks in conjunction with electromechanical temperature controllers and pre-selector switches already make it possible to start cooking in a household cooking appliance at a later time, which can also be referred to as "time-shifted operation", "time-shifted operation" or "delayed start". In order to ensure that the household cooking appliance does not pose a risk during potentially unattended cooking, it is also known to only allow time-shifted operation when a cooking chamber door is closed. The idea behind this is that flames caused by igniting food cannot then affect the surrounding area. A door switch is typically used to monitor whether the cooking chamber door is closed, but this is disadvantageous in terms of costs and can cause quality risks when installed.

EP 3 249 302 A1 discloses a household cooking appliance. The household cooking appliance has several electrically operated heating elements for heating a cooking chamber, a mechanically switching operating mode selector switch for switching on at least one heating element depending on a set operating mode, a mechanical temperature controller for regulating the switched on heating elements depending on a temperature of the cooking chamber, which mechanical temperature controller is electrically connected in series with the heating elements, and an electronic circuit, wherein a heating circuit relay is electrically connected in series with the heating elements and the mechanical temperature controller and can be switched in a clocked manner by means of the electronic circuit, the electronic circuit is connected to the operating mode selector switch in order to control a temperature set by the operating mode selector switch. to recognize the set operating mode and the electronic circuit is set up to switch the heating circuit relay in a cyclical manner depending on the recognized operating mode. A method is used to operate a household cooking appliance, whereby when an operating mode is selected in which at least one heating element is operated in a cyclical manner, the mechanical temperature controller is set to a temperature that is higher than an expected maximum cooking chamber temperature, in particular to a maximum adjustable temperature. Further prior art is provided in the document EP0213443A1 refer to.

It is the object of the present invention to at least partially overcome the disadvantages of the prior art and in particular to provide a particularly cost-effective possibility for achieving a safe, time-shifted operation of a cooking appliance while avoiding additional quality risks during assembly. This object is achieved according to the features of the independent claims. Advantageous embodiments are the subject of the dependent claims, the description and the drawings.

The object is achieved by a cooking appliance control, having an operating mode switch which is designed to set a plurality of operating modes of a cooking appliance, and a timer which is designed to set an operating sequence under at least one of the operating modes which can be set by the operating mode switch, wherein the cooking appliance control is designed such that an operating sequence which comprises at least one temperature-critical operating mode which can be set on the cooking appliance cannot be started with a time delay.

This cooking appliance control has the advantage that temperature-critical operating modes, which could cause food to ignite when activated, cannot be started at a later time, thus reducing the probability that flames can form unnoticed. Non-temperature-critical operating modes, which typically do not cause food to ignite when activated, can, however, also be started at a later time without supervision, as this is not critical from a safety point of view even if the cooking chamber door is not closed or not closed properly. In addition, this cooking appliance control is particularly inexpensive to implement. This means that a door switch is not required, which saves costs and avoids possible quality risks when installing it. If a door switch is nevertheless required, If present, the cooking appliance control can protect against a failure or error of the door switch.

The fact that the cooking appliance control is set up (e.g. programmed) to prevent a delayed start of an operating sequence that includes at least one temperature-critical operating mode that can be set on the cooking appliance, "due to the operating mode", means in particular that the delayed start of the operating sequence is prevented because the operating sequence includes the temperature-critical operating mode, e.g. because a temperature-critical operating mode is currently set via the operating mode switch. It is a further development that the timer is set up to prevent the delayed start.

The operating mode switch is designed to be operated by a user to select one of several operating modes. It can be a rotary knob, rocker switch, etc. It can be an electronic or a mechanical switch. The operating mode switch can also be referred to as an operating selector switch or pre-selector switch. It is a further development that the operating mode switch is designed to switch on one or more heating elements of the cooking appliance in a manner intended for the operating mode, depending on the operating mode set. In particular, different heating elements or combinations of heating elements can be switched on for operation for different operating modes. The heating elements can include, for example, electrical resistance heating elements, infrared radiators (heat lamps) such as halogen lamps and quartz radiators, etc.

The plurality of operating modes comprise at least one temperature-critical operating mode and at least one non-temperature-critical operating mode.

The cooking appliance is in particular a household cooking appliance with a cooking chamber that can be closed with a cooking chamber door. It is a further development that the cooking appliance is a stand-alone oven or a combination appliance, e.g. an oven/hob combination ("stove").

In the case of an oven, this typically has several heating elements, for example electrical resistance heating elements, for heating the cooking chamber or for heat treatment of food in the cooking chamber. The heating elements can, for example, be a bottom heat heating element, a top heat heating element, a grill heating element and/or a ring or circulating air heater. The operating mode switch can be used to set, for example, a bottom heat operating mode using only the bottom heat heater, a top heat operating mode using only the top heat heater, a hot air operating mode using only the ring or circulating air heater with additional operation of a circulating fan, a combined bottom/top heat operating mode using the bottom heat heater and the top heat heater, a (simple) grill operating mode using the top heat heater and the grill heater and/or a circulating air grill operating mode with simultaneous or intermittent use of the top heat heater and the grill heater on the one hand and the circulating fan.

It is a further development that the timer (also referred to as an oven timer or electronic clock) is an electronic circuit with an integrated circuit - e.g. a controller - that can switch a relay (hereinafter referred to without restriction of generality as an "interrupter relay") that is electrically connected in series with all radiators in particular. The interrupter relay can be, for example, a main relay or a heating circuit relay.

A user can set a delayed start of an operating sequence under a set operating mode on the timer, e.g. by entering a time period ("countdown period") after which operation is started with the set operating mode, or by entering a start time. The timer can be set up to keep the interrupter relay open until the start of the operating sequence and then close it. During an operating sequence, the timer can keep the interrupter relay closed or switch it intermittently, in particular with a specified duty cycle and a specified period. The interrupter relay can be an electrically controlled, mechanically switching relay. Alternatively, the interrupter relay can be an electronically controlled switching element such as a triac or similar.

The timer can have a display device for displaying, for example, a current time, the start time, the countdown time and possibly other user information. The timer can also have at least one actuating means, for example, for setting a current time, the start time, the countdown time and possibly other user-side operating parameters and/or user inputs. The At least one actuating means can, for example, have at least one button and/or at least one rotary knob, etc.

A further development is that the cooking appliance control has a mechanical temperature controller that is set up to regulate a cooking chamber temperature depending on a target temperature set by a user. This takes place without electronic control contributions, but mechanically or electromechanically. This has the advantage that the cooking appliance control can be designed to be particularly inexpensive and robust. The mechanical temperature controller can also be referred to as an electromechanical temperature controller, mechanical thermocontroller or thermostat. The mechanical temperature controller can be, for example, a capillary tube controller, a bimetal switch, etc. The mechanical temperature controller is in particular electrically connected in series with all heating elements, so that a current flow through the heating elements is possible through the mechanical temperature controller. If the temperature applied to the mechanical temperature controller is above the set target temperature, an electrical contact of the mechanical temperature controller is open and no current flows through the heating elements. If the temperature applied to the mechanical temperature controller is below the set target temperature, the electrical contact of the temperature controller is closed and current can flow through the heating elements switched on by means of the operating mode switch.

It is an embodiment that the at least one temperature-critical operating mode comprises or is a grill operating mode (simple grill operating mode and/or convection grill operating mode), in particular comprises all adjustable grill operating modes, in particular only comprises all adjustable grill operating modes. This has the advantage that the most frequently used, non-temperature-critical operating modes can be started at different times. This embodiment makes use of the idea that food in the oven can only ignite if high temperatures occur on the food due to intensive heat radiation. In practice, this is usually only the case with grill operating modes. A further advantage is that a time-delayed operation for carrying out a grill operating mode is rarely used due to its typically short duration and the frequent need to monitor the food to be grilled, so that preventing the time-delayed operation of a grill operating mode does not result in any or no significant deterioration in the user-friendliness of the cooking appliance.

In one embodiment, the operating mode switch is a mechanically switching operating mode switch that is connected to the timer by means of an electrical line, via which the timer receives information about an operating mode currently set on the operating mode switch, and the timer is set up to prevent the delayed start of the currently set operating mode, depending on the information received via the data line, if this is a temperature-critical operating mode. The use of a mechanically switching operating mode switch offers the advantage of a particularly inexpensive and robust construction.

It is a development that the mechanically switching operating mode switch is set up to open or close at least one associated electrical contact by means of a manual operation depending on the selected or actuated switching position and thus operating mode. In particular, by opening or closing the at least one contact, at least one radiator can be switched on for operation in the set operating mode. The operating mode switch can switch on different radiators or combinations of radiators for different switching positions or operating modes. The operating mode switch can be a rotary selector switch, for example. The contact can be designed as a switch. It is a development that each radiator is electrically connected in series with an associated contact, in particular an individual switch. In this way, the radiators can advantageously be switched on individually or in combination.

In a further development, the operating mode switch is a rotary selector switch which has a coding switch board, the output of which is connected to an input of the electronic circuit via the electrical line. Alternatively, the rotary selector switch can have simple switched contacts instead of a coding switch board. These designs have the advantage that the information about the currently set operating position or currently selected operating mode can be transmitted to the timer simply and inexpensively.

One embodiment is that the information includes an indication of the currently set operating mode. This allows operating modes for which time-shifted operation is prevented to be selected in a particularly differentiated manner by the time switch. This also advantageously opens up the possibility for the timer to carry out further functions associated with a specific operating mode, for example to operate at least one associated radiator in a timed manner, to switch auxiliary consumers such as circulating fans, additional fans, lights, motors, etc. on or off, etc.

One embodiment is that the information includes an indication of whether the currently set operating mode is a temperature-critical operating mode. This has the advantage that the operating mode switch can be designed particularly simply and inexpensively. In this embodiment, the information does not include the identification of the specific operating mode set, and can therefore only include an indication of whether the currently set operating mode is a temperature-critical operating mode.

It is also possible for the information to group at least two operating modes, whereby the same information is generated or provided for the operating modes of a group, e.g. grill modes - programs - top/bottom heat - off.

One embodiment is that the timer is set up to prevent the setting of a time offset (countdown time or start time) for the at least one temperature-critical operating mode from starting at a different time. This embodiment is advantageously particularly easy to implement and is particularly easy for users to understand. One development is that the timer checks whether a temperature-critical operating mode has been set when the user sets the time offset and, if so, prevents the activation of the time-delayed start. This can be implemented, for example, in such a way that when a mode for setting the time offset is activated, no time offset can be set on the timer. Alternatively, a time period can be set on the timer, but is not used by the timer to activate the time-delayed start.

It is an embodiment that the cooking appliance control is set up to run operating programs and is set up to prevent a delayed start of at least one operating program if this operating program includes a temperature-critical operating mode that can be set on the cooking appliance. This has the advantage that automatic programs that are set at least during at least one time period, a temperature-critical operating mode is provided and protected against a delayed start.

One embodiment is that the cooking appliance control is set up to prevent a change from the non-temperature-critical operating mode to a temperature-critical operating mode while maintaining the time-delayed start when a time-delayed start of a non-temperature-critical operating mode that can be set on the cooking appliance is set. This prevents a time-delayed operation of a temperature-critical operating mode from being made possible "through the back door". One development is that when a change from the non-temperature-critical operating mode to a temperature-critical operating mode is made, the time offset is automatically deleted or set to zero.

It is a further development that if the cooking appliance control prevents a delayed start of at least one temperature-critical operating mode that can be set on the cooking appliance due to the operating mode, the cooking appliance control is also set up to issue a corresponding message to a user, for example on a display device of the timer, e.g. of the type "delayed start not possible" or similar.

The object is also achieved by a cooking appliance, in particular a household cooking appliance, having a cooking appliance control as described above. The cooking appliance can be designed analogously to the cooking appliance control and has the same advantages.

The cooking appliance has in particular a cooking chamber with a loading opening that can be closed by a door, several heating elements and an operating mode switch. The cooking appliance is or includes in particular an oven.

One embodiment of the cooking appliance is a cooking appliance without a door switch, i.e. it does not have a door switch. Such a cooking appliance is advantageously particularly inexpensive and can be manufactured without any quality risks caused by installing the door switch. This is particularly advantageous for inexpensive cooking appliances that have a mechanically switching operating mode switch and an (electro)mechanical temperature controller.

In one embodiment, the cooking appliance is an oven which is designed to operate in a temperature-critical grill mode in which at least one grill heating element of the cooking appliance is activated.

The object is further achieved by a method for operating a cooking appliance, in which a delayed start of at least one temperature-critical operating mode that can be set on the cooking appliance is prevented due to the operating mode. The method can be designed analogously to the cooking appliance and the cooking appliance control and has the same advantages.

Fig.1

zeigt als Schnittdarstellung in Seitenansicht eine Skizze eines Gargeräts; und

Fig.2

zeigt ein vereinfachtes Blockschaltbild einer Gerätesteuerung des Gargeräts aus Fig.1.

The above-described properties, features and advantages of this invention, as well as the manner in which they are achieved, will become clearer and more readily understood in connection with the following schematic description of an embodiment, which is explained in more detail in connection with the drawings.

Fig.1

shows a sketch of a cooking appliance as a sectional view in side view; and

Fig.2

shows a simplified block diagram of a device control of the cooking appliance from Fig.1 .

Fig.1 shows a sectional side view of a sketch of a household cooking appliance in the form of an oven 1 with a cooking chamber 2, which has a front loading opening 4 that can be closed with a cooking chamber door 3. A door switch that detects whether the cooking chamber door 3 is closed is not present.

The cooking chamber 2 also has several heating elements 5 to 8, namely a bottom heat element 5, a top heat element 6, a grill heater 7 and a ring heater 8, wherein the ring heater 8 is arranged together with a circulating fan 9 behind a baffle wall 10.

The oven 1 also has a mechanically switching operating mode switch in the form of a rotary selector switch 11, by means of which, depending on its rotary position, the heating elements 5 to 8 are switched on individually or in combination for operation by opening or closing correspondingly assigned contacts (not shown). The heating elements 5 to 8 switched to a rotary position each correspond to a cooking mode, so that the rotary positions of the rotary selector switch 11 also correspond to the respective operating modes. are assigned. Specifically, two grill operating modes can be set here, namely a (simple) grill operating mode in which the top heat element 6 and the grill heating element 7 are switched on, and a circulating air grill operating mode in which the top heat element 6 and the grill heating element 7 on the one hand and the circulating fan 9 on the other hand are operated alternately. Each of the two grill operating modes is a temperature-critical operating mode. Alternatively, only the simple grill operating mode can be set.

The rotary selector switch 11 also has an off position in which none of the radiators 5 to 8 are switched on and therefore cannot be activated or energized.

The rotary selector switch 11 is connected here to a coding board 13, which is designed to convert the mechanical rotary position of the rotary selector switch 11 into an electrical code, the value of which clearly represents the rotary position. An output of the coding board 13 is connected via an electrical line 14 to an input of an electronic timer 15, whereby the code value of the coding board 13 is made available as information via the electrical line 14. The information therefore includes an indication of the operating mode currently set on the rotary selector switch 11.

The timer 15 has a display device 16 (see Fig.2 , e.g. a segment display, a screen, etc.) and can receive inputs from a user, e.g. via setting devices such as keys, buttons, etc. or - if the screen is a touch-sensitive screen - via control fields on the screen. The timer 15 is designed in such a way that a user can set a time-delayed cooking operation, for example by entering a period of time until the start of the time-delayed cooking operation or by entering a start time, if necessary with a confirmation to activate the time-delayed cooking operation. The start time or the time remaining until the start can then be shown on the display device 16, for example.

The oven 1 also has a mechanical temperature controller 17 that can be adjusted by the user via a rotary knob or similar (not shown), by means of which a target cooking chamber temperature in the cooking chamber 2 can be set.

The timer 15 is designed to prevent a delayed start of the grill mode(s) due to the operating mode, since these are temperature-critical in the sense that when activated or operated, food in the cooking chamber 2 could ignite. To do this, the timer 15 uses the code value to recognize the currently set operating mode and, when a grill operating mode is recognized, prevents, for example, switching to an input mode of the timer 15 for setting a time-shifted operation, setting a time offset and/or confirmation of the time-shifted operation. To do this, a corresponding message such as "time-shifted operation not possible" or similar can be displayed in the display device 16.

The timer 15 is also designed to prevent a change of the non-temperature-critical operating mode to a grill operating mode while maintaining the time-delayed start when a time-delayed operation or start of a non-temperature-critical cooking mode that can be set on the oven 1 (e.g. a bottom heat operating mode, a top heat operating mode, a combined bottom/top heat operating mode or a hot air operating mode) is set. This can be implemented, for example, by setting the time offset to zero, if necessary with the output of a corresponding message to the user.

Fig.2 shows a simplified block diagram of a device control of the oven 1 from Fig.1 . The device control here comprises at least the rotary selector switch 11 and the timer 14 and, in one variant, can also have an interrupter relay 12 which is electrically connected in series with all radiators 5 to 8. The temperature controller 17 is also electrically connected in series with all radiators 5 to 8.

After entering a time offset on the timer 15, the timer 15 keeps the interrupter relay 12 open until the start time determined by the time offset and then closes the interrupter relay 12. A duration of the operating mode or the operating sequence comprising the operating mode can also be set on the timer 15, in which case the timer 15 opens the interrupter relay 12 again after the preset duration of the operating sequence has elapsed, thus ending the operating sequence.

Of course, the present invention is not limited to the embodiment shown.

Furthermore, in one variant, a time-delayed operation can prevent not only cooking modes but also other temperature-critical operating modes, e.g. carrying out a pyrolysis operation in a cooking appliance capable of pyrolysis.

In general, "a", "an" etc. can be understood as a singular or a plural, in particular in the sense of "at least one" or "one or more" etc., as long as this is not explicitly excluded, e.g. by the expression "exactly one" etc.

List of reference symbols

1

oven

2

Cooking chamber

3

Cooking chamber door

4

Loading opening

5

Bottom heat radiator

6

Top heat radiator

7

Grill heater

8th

Ring heater

9

Circulating fan

10

Baffle

11

Rotary selector switch

12

Heating circuit relay

13

Encoding board

14

Electrical line

15

Timer

16

Display device

17

Temperature controller

Claims (13)

1. Cooking appliance controller (11, 15), having an operating mode switch (11), which is configured to set multiple operating modes of a cooking appliance (1), and a switch clock (15), which is configured to set a time-delayed start of an operating procedure under at least one of the operating modes that can be set by the operating mode switch (11), characterised in that the cooking appliance controller (11, 15) is configured such that an operating procedure which comprises at least one temperature-critical operating mode that can be set on the cooking appliance (11) cannot be started in a time-delayed manner.
2. Cooking appliance controller (11, 15) according to claim 1, wherein the at least one temperature-critical operating mode is a grill operating mode.
3. Cooking appliance controller (11, 15) according to one of the preceding claims, wherein the operating mode switch (11) is a mechanically switching operating mode switch (11), which is connected to the switch clock (15) by means of an electrical line (14), via which the switch clock (15) obtains information regarding an operating mode currently set on the operating mode switch (11), and the switch clock (15) is configured, as a function of information obtained via the electrical line (14), to prevent the time-delayed start of the currently set operating mode, if it is a temperature-critical operating mode.
4. Cooking appliance controller (11, 15) according to claim 3, wherein the information comprises an indication of the currently set operating mode.
5. Cooking appliance controller (11, 15) according to one of the preceding claims, wherein the information comprises an indication as to whether the currently set operating mode is a temperature-critical operating mode.
6. Cooking appliance controller (11, 15) according to one of the preceding claims, wherein the switch clock (15), in order to prevent the time-delayed start of the at least one temperature-critical operating mode, is configured to prevent a time delay from being set for said operating mode.
7. Cooking appliance controller (11, 15) according to one of the preceding claims, wherein the cooking appliance controller (11, 15) is configured to allow operating programs to be executed, and is configured to prevent a time-delayed start of at least one operating program if said operating program comprises a temperature-critical operating mode that can be set on the cooking appliance.
8. Cooking appliance controller (11, 15) according to one of the preceding claims, wherein the cooking appliance controller (11, 15) is configured, when a time-delayed start of a non-temperature-critical operating mode that can be set on the cooking appliance (1) is set, to prevent a change of the non-temperature-critical operating mode to a temperature-critical operating mode while retaining the time-delayed start.
9. Cooking appliance, having a cooking appliance controller (11, 15) according to one of the preceding claims.
10. Cooking appliance (1) according to claim 9, wherein the cooking appliance (1) is a cooking appliance (1) without a door switch.
11. Cooking appliance (1) according to one of claims 9 to 10, wherein the cooking appliance (1) is an oven that is configured for operation in a temperature-critical grill operating mode, in which at least one grill heating element (7) of the cooking appliance (1) is activated.
12. Cooking appliance (1) according to one of claims 9 to 11, having a mechanically switching operating mode switch (11).
13. Method for operating a cooking appliance (1) according to one of claims 9-12, characterised in that in which a time-delayed start of at least one temperature-critical operating mode that can be set on the cooking appliance (1) cannot be started in a time-delayed manner.

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