EP2798912A1

EP2798912A1 - An oven comprising a cooling fan

Info

Publication number: EP2798912A1
Application number: EP12797815.3A
Authority: EP
Inventors: Ahmet Ferit Cosan; Asli Saime Kayihan; Mehmet Marasli
Original assignee: Arcelik AS
Current assignee: Arcelik AS
Priority date: 2011-12-26
Filing date: 2012-11-26
Publication date: 2014-11-05
Anticipated expiration: 2032-11-26
Also published as: EP2798912B1; ES2572704T3; WO2013098002A1; PL2798912T3

Abstract

The present invention relates to an oven (1) comprising an exterior body (2), a cooking cavity (3) wherein the cooking process is performed, a door (4) providing access into the cooking cavity (3), a front panel (5) disposed at the upper side of the door (4), a control unit (6) disposed behind the front panel (5), an air channel (8) disposed at the upper side of the cooking cavity (3), having an outlet port (7) opening to the outside environment from between the door (4) and the front panel (5), a humidity sensor (10) detecting the rate of humidity emitted by the cooking foodstuffs and providing the cooking process to be regulated by the control unit (6) depending on the rate of humidity and a cooling fan (9) disposed inside the air channel (8), operated in accordance with a predetermined algorithm, in successive stopping and operating periods, providing the cooling of the control unit (6) by sucking air from the environment wherein the control unit (6) is situated.

Description

AN OVEN COMPRISING A COOLING FAN

The present invention relates to an oven comprising a cooling fan that provides the electronic elements to be cooled.
In ovens, the electronic elements such as the control card, etc. situated in the control panel are cooled by means of a cooling fan and a ventilating duct wherein the fan is situated, disposed at the upper side of the casing enclosing the cooking cavity. The cooling fan furthermore provides the hot and humid air passing from the chimney to the ventilating duct in the cooking process to be discharged outside. During cooking and particularly in pyrolytic ovens, the control unit and the other components in the front panel have to be cooled effectively since high temperature values may be reached. In the state of the art, the cooling fan operates in accordance with stopping and operating periods in predetermined durations during the cooking process. The control unit sends signals relating to the operating and stopping of the fan motor for certain time periods in accordance with the fan operating program stored in its memory. In the case an error occurs in cable-connector connections or the fan motor malfunctions, the fan does not operate even if the control unit sends signals to the fan motor for operating, and the fan is accepted as “operating” by the control unit even if the fan does not operate. In the case the fan motor does not operate, the control unit and the other electronic components are overheated and damaged. In some embodiments, temperature sensors disposed in the vicinity of the control unit are used for controlling the cooling fan; however, this is an expensive solution.
In the Japanese Patent No. JP1398997, a cooking device is explained which comprises a main exhaust duct and an auxiliary exhaust duct wherein temperature and humidity sensors are disposed.
In the Japanese Patent No. JP2871231, a microwave oven is explained that prevents regional burning of cooking foods, comprising a humidity sensor disposed in the ventilating duct.
In the Japanese Patent No. JP3263627, a microwave oven is explained comprising a humidity sensor disposed in the ventilating duct.
The aim of the present invention is the realization of an oven comprising a cooling fan that provides the cooling of the electronic elements and which is controlled whether or not it operates appropriately.
The oven realized in order to attain the aim of the present invention and explicated in the first claim and the respective claims thereof, comprises an air channel disposed at the upper side of the cooking cavity, having an outlet port opening to the outside environment from between the door and the front panel, a fan disposed inside the air channel and a humidity sensor disposed inside the air channel which detects the rate of humidity emitted by the cooking foodstuff, and the control unit regulates the operation of the cooling fan by monitoring the data received from the humidity sensor.
In an embodiment of the present invention, upon detecting a sudden increase of the measured humidity value in the air channel some time after the cooking process has started by monitoring data received from the humidity sensor, the control unit determines that the cooling fan is operating without any problem. The control unit, upon monitoring a regular increase and decrease, without a sudden increase of the measured humidity values in the air channel, decides that there is an error hindering the operation of the cooling fan and provides the user to be alerted.
In another embodiment of the present invention, the motor that drives the cooling fan is of variable speed and the control unit operates the cooling fan at high speed starting from the moment the monitored humidity amount decreases until the end of the cooking process.
In another embodiment of the present invention, a suction line is arranged at the lower section of the oven air channel and a discharge line at the upper section, and the humidity sensor is disposed in the discharge line.
In another embodiment of the present invention, the oven comprises an exhaust device extending from the cooking cavity to the suction line and a separator that separates the suction line from the discharge line. The separator forms a barrier between the exhaust device and the humidity sensor in the discharge line, protecting the humidity sensor from the hot air rising from the exhaust device.
In another embodiment of the present invention, the humidity sensor is disposed at the center of the discharge line, at equal distances from the outlet port of the air channel and the cooling fan and thereby is provided to measure optimum humidity.
In the oven of the present invention, the control unit and the other electronic elements subjected to high temperatures during the cooking process are cooled effectively by the cooling fan, occurrence of an error preventing operation of the cooling fan is detected by monitoring the humidity sensor data without requiring an additional control element.
The oven realized in order to attain the aim of the present invention is illustrated in the attached figures, where:
Figure 1 – is the schematic view of an oven.
Figure 2 – is the graphic of the change in data with respect to time received from the humidity sensor in an embodiment of the present invention.
Figure 3 – is the graphic of the change in data with respect to time received from the humidity sensor in another embodiment of the present invention.
The elements illustrated in the figures are numbered as follows:

Oven
Exterior body
Cooking cavity
Door
Front panel
Control unit
Outlet port
Air channel
Fan
Humidity sensor
Suction line
Discharge line
Exhaust device
Separator

The oven (1) comprises an exterior body (2), a cooking cavity (3) wherein the cooking process is performed, a door (4) providing access into the cooking cavity (3), a front panel (5) disposed at the upper side of the door (4), a control unit (6) disposed behind the front panel (5), an air channel (8) disposed at the upper side of the cooking cavity (3), having an outlet port (7) opening to the outside environment from between the door (4) and the front panel (5), a cooling fan (9) disposed inside the air channel (8), operated in accordance with a predetermined algorithm, in successive stopping and operating periods, providing the cooling of the control unit (6) by sucking air from the environment wherein the control unit (6) is situated and a humidity sensor (10) detecting the rate of humidity emitted by the cooking foodstuffs and providing the cooking process to be regulated by the control unit (6) depending on the rate of humidity.
The oven (1) of the present invention comprises the humidity sensor (10) disposed on the flow path of the humid air discharged to the outside environment by the cooling fan (9) and the control unit (6) that detects whether or not there is an error preventing operation of the cooling fan (9) by monitoring the data received from the humidity sensor (10).
The control unit (6) sends drive signal to the fan (9) motor for operation of the fan (9) and presumes that the cooling fan (9) is operating from the moment the drive signal is received; however, in the case an error occurs in the software or in the cable-connector connections or malfunctioning of the cooling fan (9) motor such as locking thereof, etc., the cooling fan (9) does not operate even if the control unit (6) sends signal. The cooling fan (9), providing the cooling of the control unit (6) and the other electronic elements disposed in the front panel (5), operates in accordance with the algorithm stored in the memory of the control unit (6), in certain successive operating and stopping time periods during the cooking process. The humidity sensor (10) delivers the data relating to the amount of humidity in the air emitted by the cooking foodstuffs and discharged by the cooling fan (9) through the air channel (8) to the control unit (6). The humidity sensor (10) is disposed inside the air channel (8) in the flow path of the humid air discharged from the cooking cavity (3) to the outside environment by the cooling fan (9). The control unit (6) controls whether or not the cooling fan (9) operates in accordance with the predetermined algorithm by monitoring the data received from the humidity sensor (10) and determines whether or not there is an error that prevents operation of the cooling fan (9). The humidity sensor (10), besides the function of regulating the cooking process in accordance with humidity measurement, is also used as a safety element controlling the operation of the cooling fan (9) and the control unit (6) and the other electronic elements in the front panel (5) having the risk of overheating, are guaranteed to be cooled by the cooling fan (9).
In an embodiment of the present invention, after some time after the start of the cooking process, if the control unit (6) detects a sudden peak (P) in the humidity values (H) measured in the air channel (8) by monitoring the change of data with respect to time received from the humidity sensor (10), the control unit (6) determines that the cooling fan (9) is operating without any problem and that there aren’t any errors preventing the operation of the cooling fan (9) (Figure 2).
When the fan (9) shifts from the stopping mode to the operating mode, the humidity sensor (10) situated on the flow path of the air discharged from the air channel (8) by the cooling fan (9), is subjected to the humid air collected in the cooking cavity (3) and sucked into the air channel (8) and a sudden peak (P) is observed in the humidity values (H) measured by the humidity sensor (10). The sudden peak (P) in the humidity values (H) is evaluated by the control unit (6) that the cooling fan (9) is operating without problems.
If the control unit (6) detects a regular increase and decrease in the humidity values (H) measured in the air channel (8) without occurrence of a sudden peak (P) by monitoring the change of data with respect to time (t) received from the humidity sensor (10), the control unit (6) decides that there is a failure relating to the cooling fan (9) motor or an error originating from cable-connector connections or the software (Figure 3). Upon detecting an error preventing the operation of the cooling fan (9), the control unit (6) ends the cooking process and provides the user to be alerted that the cooling fan (9) does not operate by means of a visual or audible alerter (not shown in the figures).
In another embodiment of the present invention, the motor driving the cooling fan (9) is of variable speed and the control unit (6) operates the cooling fan (9) at high speed from the moment the amount of humidity starts to fall until the end of the cooking process due to increase of temperature in the cooking cavity (3) and hence in the proximity of the control unit (6) by monitoring the change of humidity value with respect to time. The control unit (6) determines that more cooling is required towards the end of the cooking process by monitoring the humidity data and provides an effective cooling to be performed by operating the cooling fan (9) at high speed.
In another embodiment of the present invention, the oven (1) comprises a suction line (11) disposed at the lower section of the air channel (8), providing air to be sucked by the cooling fan (9) and a discharge line (12) disposed at the upper section of the air channel (8), providing the cooling fan (9) to discharge the air to the outside environment, and the humidity sensor (10) is disposed in the discharge line (12).
In another embodiment of the present invention, the oven (1) comprises an exhaust device (13) extending from the cooking cavity (3) to the suction line (11) in the vertical direction and a separator (14) extending from the outlet port (7) to the cooling fan (9) in the horizontal direction, separating the suction line (11) from the discharge line (12) and forming a barrier between the exhaust device (13) and the humidity sensor (10). The separator (14) extends between the exhaust device (13) and the humidity sensor (10) inside the air channel (8), prevents the hot air rising from the exhaust device (13) from directly reaching the humidity sensor (10), thus the humidity sensor (10) is not subjected to the hot air rising from the exhaust device (13) and is protected from the high temperature in the cooking cavity (3).
In another embodiment of the present invention, the humidity sensor (10) is positioned at the center of the discharge line (12), so as to be almost at equal distance from the outlet port (7) and the cooling fan (9) and the humidity sensor (10) is provided to take optimum humidity measurements by improving the detection conditions. Since the humidity data oscillates more in the sections of the discharge line (12) farther away from and nearer to the cooling fan (9), the most optimum humidity measurement is realized at the middle section of the discharge line (12).
In the oven (1) of the present invention, the control unit (6) and the other electronic elements in its proximity which are subjected to high temperature in the cooking process are cooled effectively by the cooling fan (9) and in the case the cooling fan (9) malfunctions or does not operate due to another error, the error detection is made by monitoring the data of the present humidity sensor (10) without requiring any other control element. Consequently, the delicate and high cost electronic elements are protected.
It is to be understood that the present invention is not limited by the embodiments disclosed above and a person skilled in the art can easily introduce different embodiments. These should be considered within the scope of the protection postulated by the claims of the present invention.

Claims

An oven (1) comprising an exterior body (2), a cooking cavity (3) wherein the cooking process is performed, a door (4) providing access into the cooking cavity (3), a front panel (5) disposed at the upper side of the door (4), a control unit (6) disposed behind the front panel (5), an air channel (8) disposed at the upper side of the cooking cavity (3), having an outlet port (7) opening to the outside environment from between the door (4) and the front panel (5), a cooling fan (9) disposed inside the air channel (8), operated in accordance with a predetermined algorithm, in successive stopping and operating periods and a humidity sensor (10) detecting the rate of humidity emitted by the cooking foodstuffs and providing the cooking process to be regulated by the control unit (6) depending on the rate of humidity, characterized by the humidity sensor (10) disposed on the flow path of the humid air discharged to the outside environment by the cooling fan (9) and the control unit (6) that detects whether or not there is an error preventing operation of the cooling fan (9) by monitoring the data received from the humidity sensor (10).
An oven (1) as in Claim 1, characterized by the control unit (6) that determines there aren’t any errors preventing the operation of the cooling fan (9) upon detecting a sudden peak (P) in the humidity values (H) measured in the air channel (8) after some time after the start of the cooking process by monitoring the change of data with respect to time (t) received from the humidity sensor (10).
An oven (1) as in Claim 1 or 2, characterized by the control unit (6) that decides that there is a failure relating to the cooling fan (9) motor or an error originating from cable-connector connections or the software upon detecting a regular increase and decrease in the humidity values (H) measured in the air channel (8) without occurrence of a sudden peak (P) during the cooking process by monitoring the change of data with respect to time (t) received from the humidity sensor (10).
An oven (1) as in Claim 3, characterized by the control unit (6) that ends the cooking process and provides the user to be alerted that the cooling fan (3) does not operate with visual and/or audible warning upon detecting an error preventing the operation of the cooling fan (9).
An oven (1) as in any one of the above Claims, characterized by the variable speed cooling fan (9) motor and the control unit (6) that operates the cooling fan (9) at high speed from the moment the amount of humidity starts to fall until the end of the cooking process by monitoring the change of humidity value with respect to time (t).
An oven (1) as in any one of the above Claims, characterized by a suction line (11) disposed at the lower section of the air channel (8), providing air to be sucked by the cooling fan (9), a discharge line (12) disposed at the upper section of the air channel (8), providing the cooling fan (9) to discharge the air to the outside environment and the humidity sensor (10) that is disposed in the discharge line (12).
An oven (1) as in Claim 6, characterized by an exhaust device (13) extending from the cooking cavity (3) to the suction line (11) and a separator (14) extending from the outlet port (7) towards the cooling fan (9), separating the suction line (11) from the discharge line (12) and forming a barrier between the exhaust device (13) and the humidity sensor (10).
An oven (1) as in Claim 6 or 7, characterized by the humidity sensor (10) that is positioned at the center of the discharge line (12) so as to be almost at equal distances to the outlet port (7) and the cooling fan (9).