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EP-4359709-B1 - COOKING APPLIANCE COMPRISING A COOKING CHAMBER AND A FAN FOR CIRULATING COOKING CHAMBER AIR, AND METHOD FOR OPERATING SAME

EP4359709B1EP 4359709 B1EP4359709 B1EP 4359709B1EP-4359709-B1

Inventors

  • HEINZ, VOLKER

Dates

Publication Date
20260513
Application Date
20220603

Claims (12)

  1. Cooking appliance (2), comprising a housing (4), a cooking chamber (8) arranged in the housing (4) and delimited by cooking chamber walls (6) of the housing (4), a cooking chamber door for closing a cooking chamber opening (10) of the cooking chamber (8) in a closed position of the cooking chamber door, at least one heater for heating the cooking chamber (8), a fan (12) for circulating cooking chamber air located in the cooking chamber (8), an impeller (14) of the fan (12) being arranged in the cooking chamber (8) and a motor (16) of the fan (12) being arranged outside the cooking chamber (8) on the housing (4), and the impeller (14) being torque-transmittingly connected to the motor (16) by means of a drive shaft (20) which passes through a drive shaft opening (18) in one of the cooking chamber walls (6), and a control means for controlling the heater and the fan (12), it being possible, depending on an operating state of the cooking appliance (2), and/or on a cooking program selected on the cooking appliance (2), and/or on a cooking procedure in the cooking chamber (8), for the impeller (14) to be automatically displaced, axially with respect to the drive shaft (20), between a first end position and a second end position of the impeller (14), and to be positioned in the corresponding end position, by means of a displacement device (24) of the cooking appliance (2), which displacement device is signal-transmittingly connected to the control means, characterised in that, on the drive shaft (20), a cone (52) is formed and arranged and, on the cooking chamber wall (6) that delimits the drive shaft opening (18), a cone-shaped delimiting surface (54) corresponding to the cone (52) of the drive shaft opening (18) is formed and arranged such that the cone (52) and the delimiting surface (54) form an annular gap (56) for supplying fresh air from the open surroundings into the cooking chamber (8), a clear cross section of the annular gap (56) having a predetermined minimum passage area in the first end position of the impeller (14) and having a predetermined maximum passage area in the second end position of the impeller (14).
  2. Cooking appliance (2) according to claim 1, characterised in that the displacement device (24) is designed such that, depending on an operating state of the cooking appliance (2), and/or on a cooking program selected on the cooking appliance (2), and/or on a cooking procedure in the cooking chamber (8), the impeller (14) can be automatically positioned, by means of the displacement device (24), at least in one intermediate position of the impeller (14) which is between the first end position and the second end position.
  3. Cooking appliance (2) according to claim 1 or claim 2, characterised in that the cooking appliance (2) comprises at least one sensor, signal-transmittingly connected to the control means, for automatically detecting at least one cooking parameter of the cooking procedure, preferably in that the at least one sensor is in the form of a cooking chamber camera for observing an item to be cooked located in the cooking chamber (8), and/or in the form of a humidity sensor for determining a cooking chamber humidity prevailing in the cooking chamber (8), and/or in the form of a temperature sensor for determining a cooking chamber temperature in the cooking chamber (8) and/or an item temperature of an item to be cooked located in the cooking chamber (8).
  4. Cooking appliance (2) according to any of claims 1 to 3, characterised in that the displacement device (24) comprises the motor (16), the motor (16) being designed as a shaded-pole motor such that, depending on the control of a plurality of coils (28, 30) of a stator (32) of the shaded-pole motor (16), the drive shaft (20), which is torque-transmittingly connected to a rotor (26) of the shaded-pole motor (16), automatically moves and positions the impeller (14), by means of the rotor (26) mounted in the stator (32), into its first end position or into its second end position, preferably into its first end position, into its at least one intermediate position or into its second end position.
  5. Cooking appliance (2) according to claim 4, characterised in that the plurality of coils (28, 30) is in the form of a first coil (28) and a second coil (30) that is separated from the first coil (28) by means of an electrical insulator (34), the first coil (28) and the second coil (30), as well as the control means, being designed such that the first coil (28) and the second coil (30) can be electrically conductively connected to each other in an electrical series circuit and/or an electrical parallel circuit by means of the control means.
  6. Cooking appliance (2) according to the preceding claim, wherein the clear cross section of the annular gap (56) in the at least one intermediate position of the impeller (14) has a passage area, the size of which is between the minimum and the maximum passage area.
  7. Cooking appliance (2) according to either of the two preceding claims, wherein the displacement device (24) comprises a motor mount (36) for the motor (16), which motor mount is movably held on the housing (4), and a motor mount drive (38), which is force-transmittingly connected to the motor mount (36), wherein, depending on the control of the motor mount drive (38), the motor mount (36) is movable axially with respect to the drive shaft (20) by means of the control means.
  8. Cooking appliance (2) according to the preceding claim, wherein the motor mount (36) comprises, for the motor mount (36), a retaining plate (42), which is movably held on the housing (4) by means of a longitudinal guide device (40) of the cooking appliance (2), preferably in that the longitudinal guide device (40) comprises a plurality of guide pins (44) and corresponding guide openings (46), particularly preferably in that the guide pins (44) are arranged on the housing (4) and the guide openings (46) are arranged or formed in the retaining plate (42).
  9. Cooking appliance (2) according to either of the two preceding claims, wherein the motor mount drive (38), which can be controlled by the control means, comprises a spur gear wheel (48), and the retaining plate (42) comprises a gear rack (50) which is designed to correspond to the spur gear wheel (48) and is located so as to engage therewith.
  10. Method for operating a cooking appliance (2) according to any of the preceding claims, wherein, depending on an operating state of the cooking appliance (2), and/or on a cooking program selected on the cooking appliance (2), and/or on a cooking procedure in the cooking chamber (8), the impeller (14) is automatically displaced, axially with respect to the drive shaft (20), between a first end position and a second end position of the impeller (14), and is positioned in the corresponding end position, by means of a displacement device (24).
  11. Method according to the preceding claim, wherein, depending on an operating state of the cooking appliance (2), and/or on a cooking program selected on the cooking appliance (2), and/or on a cooking procedure in the cooking chamber (8), the displacement device (24) automatically positions the impeller (14) at least in one intermediate position of the impeller (14) which is between the first end position and the second end position.
  12. Method according to either of the two preceding claims, wherein the cooking appliance (2) comprises at least one sensor signal-transmittingly connected to the control means, by means of which sensor at least one cooking parameter of the cooking procedure is automatically detected, preferably in that an item to be cooked located in the cooking chamber (8) is observed by means of the at least one sensor in a camera-based manner, and/or a cooking chamber humidity prevailing in the cooking chamber (8) is determined, and/or a cooking chamber temperature in the cooking chamber (8) and/or an item temperature of an item to be cooked located in the cooking chamber (8) is determined.

Description

The invention relates to a cooking appliance comprising a cooking chamber and a blower for circulating cooking chamber air of the type mentioned in the preamble of claim 1, as well as a method for its operation. Such cooking appliances and methods for their operation are known in the art in a multitude of embodiments. For example, the publication shows... JP 2006 283 584 A a cooking appliance of the appropriate type. Generally, cooking appliances comprise a housing, a cooking chamber arranged within the housing and bounded by the housing's walls, a cooking chamber door for closing an opening of the cooking chamber when the door is closed, at least one heating element for heating the cooking chamber, a fan for circulating the air in the cooking chamber (with a fan wheel located inside the cooking chamber and a motor for the fan located outside the cooking chamber on the housing), and a control unit for controlling the heating element and the fan. Such cooking appliances are described, for example, in the printed materials. DE 10 2016 115 529 A1 , DE 10 2015 109 854 A1 , US 5 526 734 A , DE 24 60 294 A1 , EP 3 838 086 A1 and FR 2 396 244 A1 known. The invention thus addresses the problem of improving a cooking appliance comprising a cooking chamber and a blower for circulating cooking chamber air, and a method for its operation. According to the invention, this problem is solved by a cooking appliance with the features of claim 1. The cooking appliance according to the invention can be, for example, an oven, a microwave oven, a steam cooker, or a combination appliance with a plurality of different heating methods. The cooking appliance according to the invention can also be designed as a household appliance or as a commercial appliance, i.e., a cooking appliance for professional use. Furthermore, this problem is solved by a method with the features of claim 10. Advantageous embodiments and further developments of the invention are described in the dependent claims. The advantage achievable with the invention lies particularly in the fact that a cooking appliance, comprising a cooking chamber and a fan for circulating the cooking chamber air, and a method for its operation are improved. Due to the inventive design of the cooking appliance and the method, namely by the different positioning of the fan wheel of the fan in the cooking chamber axially to the drive shaft, the airflow through the cooking chamber can be adjusted, and thus the cooking process taking place in the cooking chamber of the cooking appliance according to the invention can be influenced as desired. Accordingly, the heat distribution in the cooking chamber, and thus the cooking result of a cooking process taking place in the cooking chamber of the cooking appliance according to the invention, can be influenced much more effectively. Thus, the cooking process can be controlled or regulated not only by the speed of the fan for circulating the cooking chamber air, but also by the position of the fan wheel in the cooking chamber axially to the drive shaft, for example, behind a rear wall inserted into the cooking chamber. In principle, the cooking device according to the invention can be freely selected within wide suitable limits with regard to type, function, material and dimensions. See also the above explanations in the introductory description. A particularly advantageous embodiment of the cooking appliance according to the invention provides that the shifting device is designed such that, depending on an operating state of the cooking appliance and/or a cooking program selected on the cooking appliance and/or a cooking process in the cooking chamber, the fan wheel can be automatically positioned by means of the shifting device at least in an intermediate position of the fan wheel between the first end position and the second end position. In this way, the adjustability of the position of the fan wheel axially to the drive shaft is further improved, so that the circulation of the cooking chamber air can be designed even more variably. Accordingly, an advantageous further development of the method according to the invention provides that the shifting device automatically positions the fan wheel in the cooking chamber at least in an intermediate position of the fan wheel between the first end position and the second end position, depending on an operating state of the cooking appliance and/or a cooking program selected on the cooking appliance and/or a cooking process. A further advantageous embodiment of the cooking device according to the invention provides that the cooking device has at least one sensor connected to the control unit via signal transmission for the automatic detection of at least one cooking parameter of the cooking process; preferably, that the at least one sensor is a cooking chamber camera for observing food located in the cooking chamber and/or a humidity sensor for determining the humidity prevailing in the cooking cham