WO2023140799A1

WO2023140799A1 - An oven temperature control system

Info

Publication number: WO2023140799A1
Application number: PCT/TR2021/051156
Authority: WO
Inventors: Fatih ZUNGOR; Metin OZTURK; Ogun DUZGUN; Gonca IZCI
Original assignee: Mamur Teknoloji Sistemleri San. A.S.
Priority date: 2021-11-08
Filing date: 2021-11-08
Publication date: 2023-07-27
Also published as: EP4430917A1

Abstract

The invention relates to an oven temperature control system comprising an electric heating element (32, 34) adapted to heat a cooking chamber (12); a mechanical switch (30) controlled by a mechanical thermostat (26) adjusted to switch the temperature of the cooking chamber (12) by switching on and off in a range around a preset thermostat temperature value in a cooking mode. The temperature control system further comprises an electronic control unit (18) configured to activate the heating element (32, 34) in the cooking chamber (12); a controller (185) electrically connected to the electronic control unit (18) and determines the on-off time of the heating element (32, 34) in the cooking chamber (12) according to the feedback (181, 182) provided by the mechanical thermostat (26) to the electronic control unit (18) and a relay (186) connected the electronic control unit (18) to enable current switching.

Description

AN OVEN TEMPERATURE CONTROL SYSTEM

TECHNICAL FIELD

The invention relates to an oven temperature control system comprising an electronic control unit that controls the operation of the thermostat and controls the on/off of the heating.

BACKGROUND OF THE ART

An oven is defined as a device for cooking, melting, reheating or drying a substance in a confined space using energy sources. There are many types of ovens, from those used for cooking in daily life to those used in industry. Ovens, household ovens, tile ovens, coal production ovens, blast ovens, industrial kitchen ovens, bread ovens, etc. are the main types.

In the literature, studies are carried out to improve oven performance in terms of more efficient use of energy. The most important factors determining oven performance are energy consumption and cooking quality. It is possible to use mechanical thermostats that provide temperature control in order to reduce energy consumption in ovens and timer cards that make a time adjustment. Mechanical thermostats, as a working principle, are a device that performs on-off operation in a band around a set temperature. Generally, the ovens equipped with this device are not controlled by electronic components. In addition, while providing temperature control in the ovens, switching on and off in a continuous temperature band may also negatively affect the oven's cooking quality. In the literature, solutions are developed for providing energy efficient cooking of ovens and maintaining cooking quality.

EP3250002 discloses a household cooking appliance. The domestic cooking appliance includes several electrically operated elements to heat a cooking chamber, a mechanically switched mode switch to turn at least one heating element on and off depending on an identified operating mode, and a mechanical thermo-controller to control the connected heating element accordingly. Here, at the temperature of the cooking chamber where the thermo-controller is electrically connected in series with the heating elements, there is an electronic circuit with a heating circuit relay and at least one additional consumer that can be switched on and off with the operating mode switch. BRIEF DESCRIPTION OF THE INVENTION

The object of the invention is to provide an oven temperature control system that has an electronic control unit increasing energy efficiency for ovens controlled by a mechanical thermostat.

In order to achieve the above objective, the invention relates to an oven temperature control system comprising an electric heating element adapted to heat a cooking chamber; a mechanical switch controlled by a mechanical thermostat adjusted to switch the temperature cooking chamber by switching on and off in a range around a preset thermostat temperature value in a cooking mode. The control system further comprises an electronic control unit configured to activate the heating element in the cooking chamber; a controller electrically connected to the electronic control unit and determines the on-off time of the heating element in the cooking chamber according to the feedback provided by the mechanical thermostat to the electronic control unit and a relay connected the electronic control unit to enable current switching. In this way, the electronic control unit can be activated prior to the mechanical thermostat, and the actual temperature in the cooking mode can be set differently (high or low) from the actual thermostat temperature by control of the mechanical thermostat over the electronic control unit. With such a simple solution, the ability to intervene in the thermostat temperature determined by the mechanical thermostat allows to the creation of new cooking modes. For example, in a case where the cooking temperature is set to 200 degrees with the oven control interface in cooking mode, while the thermostat temperature is set to oscillate between 220-180 degrees, an additional command can be given, and it is possible for the electronic control unit to increase the temperature by shorten the oscillation interval and decrease by lengthening it. The heating element element activation period can be changed by the electronic control unit. Preferably, the electronic control unit receives feedback and calculates the on-off time of the heating operation as the small time differences and controls the on-off switch of the heating element by providing the operating control of the mechanical thermostat by activating the on-off operation of the heating process by the mechanical thermostat prior to the mechanical thermostat. Here, the electronic control unit can perform a calculation process in accordance with the algorithm and work as a timer. With the relay on the electronic control unit, current control can be provided in the electronic control unit. Alternatively, the electronic control unit can be controlled by a button.

In a preferred embodiment of the invention, the electronic control unit is adapted to receive feedback from an oven door in a way that adjusts the on-off time. This way, when the oven door is opened, it can quickly elevate to the previous cooking temperature value. In a preferred embodiment of the invention, the electronic control unit is adapted to receive feedback from an oven door in a way that adjusts the on-off time. In this way, depending on the opening and closing of the oven door, a heating element, for example, remains on for a longer period, allowing the cooled cooking chamber to reach the cooking temperature in a short time.

In a preferred embodiment of the invention, the electronic control unit is adjusted to reduce the mechanical thermostat temperature value set in the mechanical thermostat by interfering with the electricity flow cycle. In this way, the electronic control unit, which is activated before the mechanical thermostat and controls the operation of the mechanical thermostat, also provides energy efficiency control by reducing the set temperature value of the mechanical thermostat. In other words, thanks to the electronic control unit, the oven saves energy without influencing the cooking quality noticably.

In a preferred embodiment of the invention, the electronic control unit is configured to control the mechanical thermostat by supplying electric current. In this way, mechanical thermostat control is provided by the electronic control unit. In other words, the thermostat does not work unless there is a current flow from the electronic control unit to the mechanical thermostat. In addition, the electronic control unit also has a feature that feeds the mechanical thermostat.

A preferred embodiment of the invention includes a limit thermostat that stops operating at a predetermined temperature threshold value, measuring the heating in an operating mode of the cooking chamber. In this way, malfunctions due to overheating in the temperature control system can be prevented.

A preferred embodiment of the invention includes distributor circuit element connections on the positive conductor line of the switch. In this way, mechanical switching can be provided, and the heating elements can be cut at a suitable moment by controlling the operation via the switch.

A preferred embodiment of the invention includes one or more terminals that enable connecting lines to be connected to each other under a correct working principle. Safe connections can be provided between the lines in the temperature control system. BRIEF DESCRIPTION OF THE FIGURES

Figure 1 is a general perspective view of the control system connections of the oven according to the subject matter invention.

Figure 2 is a schematic view of an oven temperature control system that is the subject matter invention.

Figure 3 is a schematic view of the electronic control unit for an oven temperature control system according to the invention.

Figure 4 is the illustration of the analysis graph of an oven temperature control system according to the subject matter invention.

DETAILED DESCRIPTION OF THE INVENTION

In this detailed explanation, the invention is explained without any limitation and only with reference to examples to better explain the subject matter.

In Figure 1 , the oven connections of an inventive oven temperature control system are shown in a general perspective view. A muffle (13) covers the oven (10) cooking space against the environment and holds several oven parts in place. A cooking chamber (12) is surrounded by the muffle (13) and accessible from the front opening of the muffle (13). There is a front wall (14) located at the opening of the cooking chamber (12) and provided as a frame at the opening of the muffle (13). An oven door (16) is hinged and mounted to the front wall from the free end thereof. Inside the cooking chamber (12), there is a first heating element (32) and a second heating element (34) with an electrical connection that provides heating of the food to be cooked.

Figure 2, an oven temperature control system, according to the subject matter invention, is shown schematically. In the oven temperature control system (11), feedback is made to an electronic control unit (18) from a connecting line (162) in the oven door (16). The feedback to the electronic control unit (18) is connected via the feedback line (181 ) from the door. Additionally, the feedback signal from the output pin (264) of a mechanical thermostat (26) is also connected to the electronic control unit (18) via the feedback line (182) from a thermostat. The mechanical thermostat (26) performs an on-off operation in a band around a set temperature value. The performed on-off operation is controlled by the electronic control unit, providing electrical cut-off or transmission on the first and second heating elements (32, 34). A connection is provided to the output pin (264) of the mechanical thermostat from the conductor line connection pin (282) of a lamp (28). A negative line connection pin (284) of the lamp (28) is connected to a negative line terminal (384) of a first terminal (38) via the negative conductor line (22). A grounding terminal (386) of the first terminal (38) and a grounding terminal (406) of the second terminal (40) are interconnected. Thus, the lamp (28) is turned on, and the cooking chamber (12) of the oven (10) is illuminated. Terminals (38, 40) provide connection lines (20, 22, 24) in two or more parts to be connected to each other under a correct working principle. A connection is made to the input pin (262) located on a mechanical thermostat (26) of the first terminal (38) from a thermostat connection line (183) located in the electronic control unit (18). Thus, energy flow is provided to the mechanical thermostat (26) via the electronic control unit (18), and the operation of the mechanical thermostat (26) is controlled by the connections (182, 183, 262, 264). A connection is made from an outer conductor connection line (184) on the electronic control unit (18) to a positive conductor line (20) of the temperature control system (11 ).

Additionally, there is a negative conductor line (22) and a grounding line (24) on the temperature control system (11). There is a mechanically switched switch (30) in the temperature control system (11), which is connected (304) in a controlled manner via the mechanical thermostat (26) to turn the cooking chamber heating element (32, 34) on or off. A first-leg connection pin (301 ) and a sixth-leg connection pin (306) of the switch (30) can be in transmission or cut-off, providing a mutual connection. A second-leg connection pin (302) and a fifth-leg connection pin (305) of the switch (30) can be in the conduction or cut-off manner, providing a mutual connection. In addition, a third-leg connection pin (303) and a fourth-leg connection pin (304) of the switch (30) can be in transmission or cut off by providing a mutual connection. The first leg connector pin (301 ) of the switch (30) to a lead connector pin (322) of the first heating element (32); the second leg connector pin (302) to a lead connector pin (342) of the second heating element (34); the third leg connection pin (303) is connected to an outer conductor connection line end (402) of the second terminal (40) and to the outer conductor connection line (184) of the electronic control unit (18) via the positive conductor line (20). In addition, the fourth leg connection pin (304) of the switch (30) is connected to an output pin (364) of a limit thermostat (36) and the fifth leg connection pin (305) to the output pin (264) of the mechanical thermostat. Here, the limit thermostat (36) cuts off the electrical conduction and stops working if overheating occurs during cooking. No line connection is made to the sixth leg connection pin (306). A negative line connection pin terminal (40) are connected to each other. In addition, the negative line connection pin (324) of the first heating element (32) is connected to a negative line connection pin (344) of the second heating element (34) via the negative conductor line (22). A ground line pin (326) of the first heating element (32) is idle. A ground line pin (346) of the second heating element 34 is also free. An input pin (362) of the limit thermostat (36) and an outer conductor line terminal (382) of the first terminal (38) are connected to each other via the positive conductor line (20). In addition, the negative line terminal (404) of the second terminal (40) and the negative line terminal (384) of the first terminal (38) are connected to each other.

In Figure 3, the electronic control unit of an oven temperature control system according to the subject matter is shown schematically. The connection lines (181 , 182, 183, 184) of the electronic control unit (18) mentioned in Figure 2 are shown. In addition, during the cooking in the cooking chamber (12), the on-off time of the heating can be calculated with a controller (185) located on the electronic control unit (18), which receives feedback from the mechanical thermostat (26) and the oven door (16). Here, the controller (185) includes an algorithm that calculates the on-off time. Since the electronic control unit (18) controls the operation of the mechanical thermostat (26), it is a unit that cuts or transmits the electrical transmission to the heating elements (32, 34) in accordance with the on-off times calculated by the controller (185). The controller (185) works both to calculate and act as a timer. Electrical conduction and cut-off control of the heating elements (32, 34) are provided via mechanical switching switches (30). As a mode of operation, the arrival of feedback, the calculation of the most appropriate on-off times, the control of the mechanical thermostat (26) connected to the heating elements (32, 34) via the switch (30) with the electronic control unit (18) and hysteresis control of the heating elements (32, 34). The electronic control unit (18) reduces the adjusted temperature band of the mechanical thermostat (26) and thus provides energy efficiency in the oven (10) without reducing the cooking quality. A relay (186) connected to the electronic control unit (18) provides current switching.

Figure 4 shows the oven temperature control system analysis graph according to the invention. In the analysis graph given here, a power comparison was made with an oven center. According to the analysis graph, it has been determined that the electronic control unit (18) and the system (11 ) control the energy by acting prior to the mechanical thermostat (26) when necessary, and as a result, the oven (10) works more efficiently and providing energy efficiency. REFERENCE NUMBERS

10 Oven 302 Second leg connection pin

11 Temperature control system 303 Third leg connection pin

12 Cooking chamber 304 Fourth connecting pin

13 Muffle 305 Fifth pin connecting pin

14 Front wall 306 Sixth leg connecting pin

16 Oven door 32 First heating element

162 Connecting line 322 conductor line connection pin

18 Electronic control unit 324 Negative line connection pin

181 Feedback line from the door 326 Ground line pin

182 Feedback line from thermostat 34 Second heating element

183 Connection line to the thermostat 342 Conductor line connection pin

184 Outer conductor connection line 344 Negative line connection pin

185 Controller 346 Ground line pin

186 Relay 36 Limit thermostat

20 Positive conductor line 362 Input pin

22 Negative conductor line 364 Output pin

24 Earthing line 38 First terminal

26 Mechanical thermostat 382 Outer conductor line terminal

262 Thermostat input pin 384 Negative line connector

264 Thermostat output pin 386 Ground wire terminal

28 Lamp 40 Second terminal

282 Conductor line connection pin 402 Outer conductor line terminal

284 Negative line connection pin 404 Negative line terminal

30 Switch 406 Ground wire terminal

301 First leg connection pin

Claims

1- An oven temperature control system comprising an electric heating element (32, 34) adapted to heat a cooking chamber (12); a mechanical switch (30) controlled by a mechanical thermostat (26) adjusted to switch the temperature of the cooking chamber (12) by switching on and off in a range around a preset thermostat temperature value in a cooking mode characterized in that an electronic control unit (18) configured to activate the heating element (32, 34) in the cooking chamber (12); a controller (185) electrically connected to the electronic control unit (18) and determines the on-off time of the heating element (32, 34) in the cooking chamber (12) according to the feedback (181 , 182) provided by the mechanical thermostat (26) to the electronic control unit (18) and a relay (186) connected the electronic control unit (18) to enable current switching.

2- An oven temperature control system according to claim 1 , wherein the electronic control unit (18) is adapted to receive feedback from an oven door (16) in a way that adjusts the on-off time.

3- An oven temperature control system according to any one of the previous claims, wherein the electronic control unit (18) is adjusted to reduce the mechanical thermostat temperature value set in the mechanical thermostat (26) by interfering with the electricity flow cycle.

4- An oven temperature control system according to any one of the preceding claims, wherein electronic control unit (18) is configured to control the mechanical thermostat (26) by supplying electric current.

5- An oven temperature control system according to any one of the preceding claims, wherein distributor circuit element connections (301 , 302, 303, 304, 305, 306) are provided in the positive conductor line (20) of the switch (30).