A stove with pyrolytic self-cleaning includes an oven having a cooking chamber to be heated and pyrolytically self-cleaned. An automatic pyrolysis system recognizes a limit value for soiling and controls pyrolytic self-cleaning. The automatic pyrolysis system includes a limit value comparator and a pyrolysis trigger connected to the limit value comparator.

The invention relates to a stove with pyrolytic self-cleaning, having a 
muffle to be operated with a heating element disposed in at least one wall 
region and optionally with additional convection heating, a convection 
blower for venting the muffle, and means for pyrolytic self-cleaning. 
The possibility of preventing soiling of a cooking chamber with the aid of 
pyrolytic self-cleaning, or of eliminating such soiling, is quite well 
known. Heretofore, the decision to initiate the pyrolytic cleaning process 
was left to the operator, for instance a housewife. The result was 
variable cleaning cycles. 
It is accordingly an object of the invention to provide a pyrolytic 
self-cleaning oven, which overcomes the hereinafore-mentioned 
disadvantages of the heretofore-known devices of this general type and 
which creates an objectively grounded initiation of pyrolytic cleaning 
operations. 
With the foregoing and other objects in view there is provided, in 
accordance with the invention, a stove with pyrolytic self-cleaning, 
comprising an oven having a cooking chamber to be heated, means for 
pyrolytically self-cleaning the cooking chamber, and an automatic 
pyrolysis system for recognizing a limit value for soiling and controlling 
pyrolytic self-cleaning, the automatic pyrolysis system including a limit 
value comparator and a pyrolysis trigger connected to the limit value 
comparator. 
In accordance with another feature of the invention, there is provided a 
sensor system being disposed in the cooking chamber and connected to the 
limit value comparator, the limit value comparator including a register 
and means for entering operationally dictated oven soiling values from the 
sensor system in the register, for comparing the oven soiling values with 
a limit value for oven soiling, and for activating the pyrolysis trigger 
if the limit value is exceeded. 
Through the use of the apparatus according to the invention, the operation 
of cleaning the oven muffle is recommended by the appliance itself, if the 
soiling is extensive enough. Soiling of the oven muffle can be detected by 
suitable sensors which, for instance, evaluate the electrical 
conductivity, or other systems which, for instance, make decisions with 
the aid of ultrasound, and process them. 
In accordance with a further feature of the invention, the limit value 
comparator includes a register and means for forming an actual value for 
oven soiling based on type and frequency of use of oven functions, for 
entering the actual value into the register, for comparing the actual 
value with a limit value for oven soiling, and for activating the 
pyrolysis trigger if the limit value is exceeded. It is therefore seen 
that another possibility for detecting soiling values for the oven muffle 
is to use a time and use-dependent system for the particular stove. 
In accordance with an added feature of the invention, the pyrolysis trigger 
activated by the limit value comparator trips pyrolytic self-cleaning. 
In accordance with an additional feature of the invention, there is 
provided a pyrolysis indicator with which the pyrolysis trigger visually 
signals pyrolytic self-cleaning. 
In accordance with yet another feature of the invention, there is provided 
a pyrolysis indicator with which the pyrolysis trigger audibly signals 
pyrolytic self-cleaning. 
In accordance with yet a further feature of the invention, there is 
provided a heating trigger being enabled by the pyrolysis trigger for 
pyrolytic self-cleaning following an acknowledgement signal. 
In accordance with yet an added feature of the invention, there is provided 
a heating trigger, the pyrolytic trigger compelling pyrolytic 
self-cleaning and enabling the heating trigger for pyrolytic 
self-cleaning. 
In accordance with yet an additional feature of the invention, there are 
provided means for permitting an operator to erase the register adding up 
the soiling values. 
In accordance with again another feature of the invention, there are 
provided means for tripping pyrolytic self-cleaning with a compulsory 
start. 
With the objects of the invention in view, there is also provided a stove 
with pyrolytic self-cleaning, comprising an oven, a muffle disposed in the 
oven having at least one wall region defining a cooking chamber, a heating 
element disposed in the at least one wall region for heating the cooking 
chamber, means for pyrolytically self-cleaning the cooking chamber, and an 
automatic pyrolysis system for recognizing a limit value for soiling and 
controlling pyrolytic self-cleaning, the automatic pyrolysis system 
including a limit value comparator and a pyrolysis trigger connected to 
the limit value comparator. 
In accordance with a concomitant feature of the invention, there are 
provided means for convection heating the cooking chamber, and a 
convection blower for venting the muffle. 
Other features which are considered as characteristic for the invention are 
set forth in the appended claims. 
Although the invention is illustrated and described herein as embodied in a 
pyrolytic self-cleaning stove, it is nevertheless not intended to be 
limited to the details shown, since various modifications and structural 
changes may be made therein without departing from the spirit of the 
invention and within the scope and range of equivalents of the claims. 
The construction and method of operation of the invention, however, 
together with additional objects and advantages thereof will be best 
understood from the following description of specific embodiments when 
read in connection with the accompanying drawings.

Referring now to the figures of the drawing in detail and first, 
particularly, to FIG. 1 thereof, there is seen a stove 1 equipped with 
pyrolytic self-cleaning, having a cooking chamber 2, a pyrolysis indicator 
3, controls 4, an electrical input control and stove control means 5, an 
air expulsion device 6, a door handle 7, a window 8, and a pattern of 
holes 9 located in the cooking chamber 2 for convection heating. The 
cooking chamber 2 is located inside a muffle 2' and can be heated by means 
of a heating element 14 disposed in at least one wall region of the muffle 
2'. The cooking chamber 2 can be optionally heated with additional 
convection heating through the use of the holes 9, while the muffle 2' is 
vented by a convection blower 10. 
A schematic control loop for the pyrolytic self-cleaning is shown in FIG. 
2. The stove 1 with pyrolytic self-cleaning which is equipped with the 
pyrolysis indicator 3, has an optional sensor system 15 in the cooking 
chamber 2. A limit value comparator 11 with a soiling register 11' 
receives operationally dictated oven soiling values from the sensor system 
15 disposed in the cooking chamber 2. The limit value comparator 11 
compares these values with an oven soiling limit value, and if the limit 
value is exceeded, a pyrolysis trigger 12 is activated, which in turn 
enables a heating control 13 for pyrolytic self-cleaning, so that the 
pyrolytic self-cleaning can be initiated. If the limit value comparator 11 
has determined that the limit value has been exceeded, then a visual 
and/or audible signal is provided by the pyrolysis indicator 3. Controls 
for the pyrolysis indicator 3 make it possible to erase the indication, 
which is optionally associated with resetting of the limit value 
comparator register 11', or to initiate pyrolysis immediately. 
If the cooking chamber 2 has no sensor system capable of detecting oven 
soiling, then an option exists for the limit value comparator 11 to form 
an actual value for oven soiling from the type and frequency of use of the 
oven functions, to enter this value into the soiling register 11' for the 
limit value comparator, to compare it with a limit value for oven soiling, 
and to activate the pyrolysis trigger 12 if this limit value is exceeded. 
The pyrolysis trigger 12 which is activated by the limit value comparator 
11, trips or signals the pyrolytic self-cleaning. The pyrolytic 
self-cleaning can be signaled visually or audibly by means of the 
pyrolysis indicator 3. Following an acknowledgement signal, the pyrolysis 
trigger 12 enables the heating control 13, so that the pyrolysis operation 
in the cooking chamber can begin. A pyrolytic self-cleaning can also be 
compelled after repeated acknowledgements, by means of the pyrolysis 
trigger 12. The soiling values provided to the limit value comparator 11 
by the sensor system 15 or by adding up time values, are added up in the 
limit value comparator register 11'. If the comparison with the limit 
value comparison register 11' and a memorized soiling limit value shows 
that the limit value has been exceeded, and if the operator wishes to 
postpone the pyrolytic self-cleaning, then the soiling values added up in 
the limit value comparator register 11' can be erased or reduced, by means 
of an erase signal. A compulsory start of the pyrolytic self-cleaning is 
equally possible.