JP2023022423A - Oven cooking device - Google Patents

Abstract

To provide an oven cooking device capable of accurately increasing respective temperatures on upper and lower parts in a firing furnace, when heating an internal part of the firing furnace in a natural convection type, by upper and lower heaters.SOLUTION: An oven cooking device 10 is configured so that a control unit 40 acquires an upper part determination result obtained by determining a change state of a temperature of an upper part in a firing furnace 20 on the basis of an upper part detection temperature of an upper part temperature sensor 33, and an upper part comparison result obtained by comparing an upper part upper limit or an upper part lower limit temperature prediction time with an upper part delay reference time, controls on/off of an upper heater on the basis of the upper part determination result and the upper part comparison result, then acquires a lower part determination result obtained by determining a change state of a temperature of a lower part in the firing furnace 20 on the basis of a lower part detection temperature of a lower part temperature sensor 34, and a lower part comparison result obtained by comparing a lower part upper limit or a lower part lower limit temperature prediction time with a lower part delay reference time, and controls on/off of a lower heater on the basis of the lower part determination result and the lower part comparison result, and can set each of the upper part delay reference time and the lower part delay reference time, to an independent time.SELECTED DRAWING: Figure 3

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oven cooking apparatus that heats the inside of a baking furnace by natural convection using upper and lower heaters provided in the upper and lower parts of the baking furnace.

Patent Literature 1 discloses a deck oven (oven cooking apparatus) for baking food such as bread dough. This deck oven is provided with three stages of furnace units in a main body frame, each furnace unit has a top heater provided in the upper part of the furnace and a bottom heater provided in the lower part of the furnace. The interior of the furnace is heated by the top and bottom heaters, and the object to be cooked such as bread dough carried into the furnace is heated by the top and bottom heaters.

JP-A-2004-267493

In this type of deck oven, the inside of the furnace is heated by upper and lower heaters, and the upper and lower heaters are based on the temperatures detected by the upper and lower temperature sensors provided at the upper and lower parts of the furnace. controlled on and off. This type of deck oven uses a natural convection system in which heated air (hot air) flows upward, instead of a forced convection system in which a fan is installed in the furnace to force the air to circulate. When the inside of the furnace is heated by natural convection with the upper and lower heaters, the control delay of the upper and lower heaters tends to occur due to the large thermal inertia in the furnace, and the temperature of the upper and lower parts of the furnace becomes higher than the set temperature. It was easy to hunt greatly on the upper and lower sides.

In addition, the steam convection oven disclosed by the applicant of the present application in Japanese Patent Application Laid-Open No. 2010-198126 is the difference between the temperature detected by the temperature sensor and the set temperature so that the inside of the cooking chamber becomes the set temperature (target temperature). Temperature deviation calculating means for calculating the temperature deviation; Temperature deviation gradient calculating means for calculating the temperature deviation gradient from the temperature deviation calculated over time; prediction time calculation means for calculating upper limit temperature prediction time or lower limit temperature prediction time; upper limit temperature deviation calculation means and lower limit temperature deviation calculation means for calculating upper limit temperature deviation or lower limit temperature deviation; The heater is on/off controlled based on the determination result and the predicted time of the upper limit temperature or the predicted time of the lower limit temperature.

This steam convection oven executes forced convection heating control by turning on and off the heater as described above while convecting the air in the cooking chamber with a convection fan. For this reason, in addition to quickly spreading the heat from the heater in the cooking chamber by the convection air, by controlling the on/off of the heater based on the above-described determination result and the upper limit temperature prediction time or lower limit temperature prediction time, The temperature inside the cooking chamber is less prone to hunting, which greatly exceeds the upper limit temperature and the lower limit temperature of the set temperature. In the deck oven of Patent Document 1, since the inside of the furnace is heated by natural convection with the upper and lower heaters, the way of heat transfer is different between the upper and lower parts of the furnace, and both the upper and lower heaters are heated. Even if heating control of a heater such as the above steam convection oven is performed under the same control conditions, there is a possibility that the temperatures of the upper and lower parts of the furnace cannot be controlled with high accuracy. SUMMARY OF THE INVENTION It is an object of the present invention to heat each temperature of an upper portion and a lower portion of a firing furnace with high accuracy when the interior of the firing furnace is heated by the upper and lower heaters in a natural convection manner.

In order to solve the above problems, the present invention provides a baking furnace for baking an object to be cooked, an upper heater for heating the upper part in the baking furnace, a lower heater for heating the lower part in the baking furnace, and a An upper temperature sensor that detects the temperature of the upper part, a lower temperature sensor that detects the temperature of the lower part in the kiln, and upper and lower limit temperatures that are the upper and lower limits of the upper set temperature that is the set temperature of the upper part of the kiln. The upper heater is controlled on and off so that the temperature is between, and the lower heater is set to a temperature between the lower upper limit and the lower lower limit temperature, which are the upper and lower limits of the lower set temperature, which is the set temperature of the lower part of the firing furnace. and a control device that controls on and off, and heats the inside of the baking furnace by natural convection with upper and lower heaters, wherein the control device controls the temperature detected by the upper temperature sensor, which is the temperature detected by the upper temperature sensor. The upper judgment result of judging the temperature change situation where the temperature at the upper part of the furnace approaches or leaves the upper upper limit temperature or lower limit temperature while the temperature rises or falls, and the temperature at the upper part of the firing furnace reaches the upper upper limit temperature or the upper lower limit temperature. Acquire the upper comparison result by comparing the upper upper limit or upper lower limit temperature prediction time to be reached with the upper delay reference time set as the reference for the delay time due to thermal inertia, and control the upper heater on / off based on the upper determination result and upper comparison result Then, from the lower detection temperature, which is the detection temperature of the lower temperature sensor, the temperature of the lower part in the firing furnace rises or falls while approaching or leaving the lower upper limit temperature or the lower lower limit temperature. , Lower limit comparison results are obtained by comparing the lower delay reference time, which is set as the reference for the delay time due to thermal inertia, to the lower upper limit or lower lower limit temperature prediction time at which the temperature in the lower part of the kiln reaches the lower upper limit or lower lower limit temperature. and controlling the on/off of the lower heater based on the lower determination result and the lower comparison result, and setting the upper delay reference time and the lower delay reference time independently of each other. is.

In the oven cooking apparatus configured as described above, the control device controls the temperature of the upper part of the baking furnace to rise or fall from the upper detection temperature, which is the temperature detected by the upper temperature sensor, and approach the upper upper limit or upper lower limit temperature. Alternatively, set the upper judgment result of judging the changing state of the leaving temperature and the upper upper limit or upper lower limit temperature prediction time when the upper temperature in the kiln reaches the upper upper limit or upper lower limit temperature as the reference for the delay time due to thermal inertia. An upper comparison result is obtained by comparing with the upper delay reference time, and the upper heater is on/off controlled based on the upper determination result and the upper comparison result. Based on the upper judgment result, which is the change in the temperature of the upper part in the kiln, and the result of comparing the upper limit or lower limit temperature predicted time with the upper delay reference time set as the reference for the delay time due to thermal inertia. Since the heater is controlled on and off, it is possible to control the heating with high accuracy between the upper limit temperature and the lower limit temperature in the upper part of the firing furnace with large thermal inertia by heating in the state of natural convection. Become.

In addition, the control device determines the change in temperature from the lower detection temperature, which is the detection temperature of the lower temperature sensor, when the temperature in the lower part of the firing furnace approaches or departs from the lower upper limit temperature or the lower lower limit temperature while increasing or decreasing. Comparison of the lower judgment result with the lower delay reference time, which is set as the reference for the delay time due to thermal inertia. The results are acquired, and the lower heater is controlled to be on or off based on the lower judgment result and the lower comparison result. Based on the lower judgment result of judging the change in temperature of the lower part in the firing furnace and the comparison result of the lower upper limit or lower lower limit temperature prediction time with the lower delay reference time set as the reference of the delay time due to thermal inertia Since the lower heater is controlled to turn on and off, it is possible to control the heating with high accuracy between the upper limit temperature and the lower limit temperature in the lower part of the firing furnace with large thermal inertia by heating in the state of natural convection. become.

In addition, the inside of the kiln is heated by natural convection with the upper and lower heaters. If the heating is controlled with such a control setting, one of the upper and lower portions of the firing furnace may exceed the upper limit temperature and the lower limit temperature, resulting in large hunting. On the other hand, the upper delay reference time and the lower delay reference time can be set independently. It is possible to set the delay reference time according to the way of propagation, and it is possible to perform highly accurate heating control between the upper limit temperature and the lower limit temperature for both the upper and lower parts of the firing furnace.

1 is a front view of an oven cooking apparatus of the present invention; FIG. 2 is a perspective view of FIG. 1 with the door opened; FIG. It is a cross-sectional view along line AA. It is a block diagram which shows a control apparatus. FIG. 4A is a diagram (a) showing first to fourth change states of the upper limit temperature showing the relationship between the upper limit temperature deviation and the upper limit temperature prediction time, and FIG. It is the figure (b) which shows - the 4th change state. FIG. 5 is a schematic diagram showing temperature changes in each of first to fourth change states; FIG. 4 is a schematic diagram showing upper and lower temperature prediction times for upper or lower temperature limits;

An embodiment of the oven cooking apparatus of the present invention will be described below with reference to the accompanying drawings. As shown in FIGS. 1 and 2, the oven cooking apparatus 10 of the present invention heats and bakes bread dough or baked confectionery dough (object to be cooked) in a natural convection baking furnace 20. By opening the door 21 provided in the front portion of the firing furnace 20, the object to be fired can be carried in and out of the firing furnace 20 through the front opening portion 20a. The oven cooking apparatus 10 is installed on a table, a counter, or a device such as a dough conditioner in a store, a workshop, or the like, and is installed vertically in multiple stages as necessary.

As shown in FIGS. 1 to 3, the oven cooking apparatus 10 includes a substantially rectangular parallelepiped casing 11, the right side of the casing 11 is the machine room 12, and the remaining part of the casing 11 is the baking furnace 20. are set up. The baking furnace 20 is used to bake an object to be cooked, such as dough for bread or confectionery, and has a substantially rectangular parallelepiped shape with a front opening 20a for loading and unloading the object to be cooked. A door 21 is provided at a lower front portion of the firing furnace 20 so as to be rotatable about a horizontal axis, and the door 21 closes a front opening 20a of the firing furnace 20 so as to be openable and closable. A ceramic hearth plate 22 is provided at the bottom of the firing furnace 20 , and a tray containing the food to be cooked can be placed on the top of the hearth plate 22 inside the firing furnace 20 . A heat insulating material 23 using glass wool is provided on the outer peripheral surface of the firing furnace 20 , and the heat insulating material 23 makes it difficult for the heat in the firing furnace 20 to be transmitted to the surroundings including the casing 11 and the machine room 12 .

As shown in FIG. 3 , an upper heater 31 is provided in the upper portion of the firing furnace 20 , and a lower heater 32 is provided below the hearth plate 22 in the lower portion of the firing furnace 20 . The upper heater 31 heats the upper portion of the firing furnace 20 , and the lower heater 32 heats the lower portion of the firing furnace 20 . The upper and lower heaters 31 and 32 are U-shaped heater elements whose longitudinal ends are attached to the upper and lower right side walls of the firing furnace 20. The upper heater 31 has four heater elements 31a to 31d. are arranged side by side, and the lower heater 32 has three heater elements 32a to 32c arranged side by side.

In this embodiment, the maximum output value (maximum power value) that can be output from the heater elements 31a and 31d arranged at the frontmost side and the rearmost side of the upper heater 31 is 515 W, and they are arranged in the middle part in the front-rear direction. The maximum output value (maximum power value) that can be output from the heater elements 31b and 31c is 290W. The maximum output value (maximum electric power value) that can be output from the heater element 32a arranged on the front side of the lower heater 32 is 515 W. The maximum output value (maximum power value) that can be output is 290W.

As shown in FIG. 3 , an upper temperature sensor 33 is provided on the upper right side of the firing furnace 20 , and the upper temperature sensor 33 detects the temperature of the upper portion of the firing furnace 20 . The upper temperature sensor 33 is arranged at a position slightly lower than the upper heater 31 on the upper right side of the firing furnace 20 and between the second heater element 31b from the front and the third heater element 31c from the front. there is A lower temperature sensor 34 is provided at the lower right side of the firing furnace 20 , and the lower temperature sensor 34 detects the temperature of the lower portion of the firing furnace 20 . The lower temperature sensor 34 is located at the same height as the lower heater 32 on the lower right side of the firing furnace 20, and between the frontmost heater element 32a and the second heater element 32b from the front. . Although FIG. 3 is a cross-sectional view showing the left side wall of the firing furnace 20, the upper and lower temperature sensors 33 and 34 are attached to the right side, so the upper and lower temperature sensors 33 and 34 are indicated by dashed lines. ing.

As shown in FIG. 4, the oven cooking apparatus 10 includes a control device 40, which controls the upper heater 31 (heater elements 31a to 31d), the lower heater 32 (heater elements 32a to 32c), the upper temperature The sensor 33 is connected to the lower temperature sensor 34 . The control device 40 has a microcomputer (not shown), and the microcomputer has a CPU, a RAM, a ROM and a timer (all not shown) connected via a bus.

The control device 40 has a heating operation process in the ROM for heating the inside of the firing furnace 20 to the upper and lower set temperatures. Up to 100% can be changed in 6 steps. When the control device 40 executes the heating operation process, the control device 40 turns on and off the upper heater 31 so that the temperature of the upper part of the baking furnace 20 is between the upper limit temperature and the upper lower limit temperature, which are the upper limit and lower limit of the upper set temperature. , the lower heater 32 is turned on and off so that the temperature of the lower part of the firing furnace 20 is between the lower upper limit temperature and the lower lower limit temperature, which are the upper limit and the lower limit of the lower set temperature. The heating operation process includes a manual operation process for setting the upper and lower set temperatures in the firing furnace 20 and the outputs of the upper and lower heaters 31 and 32, and the upper and lower set temperatures in the firing furnace 20 and the upper and lower heaters. A program operation process in which the outputs of 31 and 32 are preset is provided, and the manual operation process and the program operation process can be selected.

The control device 40 has a heating control process for heating and controlling the inside of the firing furnace 20 when performing the heating operation process. The heating control process includes an upper heating control process for controlling the heating of the upper part of the firing furnace 20 and a lower heating process for controlling the heating of the lower part of the firing furnace 20. By independently executing the heating control process, the upper and lower portions can be controlled at different temperatures and outputs. In order to execute the upper and lower heating control process, the control device 40 acquires the upper and lower temperature control information in the kiln 20 from the temperatures detected by the upper and lower temperature sensors 33 and 34 over time.

The upper temperature regulation control information mainly includes the upper determination result obtained by determining the temperature change status in which the upper temperature in the firing furnace 20 approaches or departs from the upper upper limit or upper lower limit temperature while increasing or decreasing, and the temperature inside the firing furnace 20. It is information based on the upper delay reference time set as the reference of the delay time due to thermal inertia and the upper comparison result compared . In addition, the lower temperature control information mainly includes the lower determination result obtained by determining the change in temperature in which the temperature in the lower part of the firing furnace 20 approaches or departs from the lower upper limit temperature or the lower lower limit temperature while increasing or decreasing, and the lower temperature control information. Information based on the lower delay reference time set as the reference of the delay time due to thermal inertia and the lower comparison result compared is.

Next, the upper and lower temperature control information will be described in detail. In order to acquire upper temperature control information, the control device 40 calculates an upper temperature deviation, which is the difference between the upper temperature detected by the upper temperature sensor 33 and the upper set temperature, which is the set temperature of the upper portion of the baking furnace 20. temperature deviation calculation means; upper upper limit temperature deviation calculation means for calculating an upper upper limit temperature deviation that is the difference between the upper temperature detected by the upper temperature sensor 33 and the upper upper limit temperature that is the upper limit of the upper set temperature; Upper and lower limit temperature deviation calculating means for calculating an upper and lower limit temperature deviation, which is the difference between the upper detected temperature and the upper and lower limit temperature, which is the lower limit of the upper set temperature.

In addition, the control device 40 monitors the upper temperature deviation calculated by the above-described upper temperature deviation calculating means, an overshoot temperature that is a temperature deviation higher than the upper set temperature, and an undershoot temperature that is a temperature deviation lower than the set temperature. Calculation means for calculating . The controller 40 constantly monitors this temperature deviation and updates the highest temperature deviation value as the provisional overshoot temperature and updates the lowest temperature deviation value as the provisional undershoot temperature. These provisional overshoot temperature and provisional undershoot temperature are determined before the upper heater 31 is turned on and before it is turned off. The control device 40 corrects the upper upper limit correction temperature and the upper lower limit correction temperature based on the overshoot temperature and the undershoot temperature obtained from the upper temperature deviation calculated by the upper temperature deviation calculating means. The upper upper limit temperature is the upper set temperature plus the upper upper limit corrected temperature, and the upper lower limit temperature is the upper set temperature plus the upper lower limit corrected temperature.

The upper temperature deviation, the upper upper limit temperature deviation and the upper lower limit temperature deviation are calculated by the following equations.
Upper temperature deviation (K) = upper detected temperature - upper set temperature

Upper upper limit temperature deviation (K) = upper detected temperature - upper upper limit temperature
= upper temperature deviation + upper set temperature - (upper set temperature +
upper upper limit correction temperature)
= upper temperature deviation - upper upper limit corrected temperature

Upper detected temperature = Upper temperature deviation + Upper set temperature Upper upper limit temperature = Upper set temperature + Upper upper limit corrected temperature

Upper and lower limit temperature deviation (K) = Upper detected temperature - Upper lower limit temperature
= upper temperature deviation + upper set temperature - (upper set temperature +
upper and lower limit correction temperature)
= upper temperature deviation - upper lower limit correction temperature

... upper detected temperature = upper temperature deviation + upper set temperature ... upper lower limit temperature = upper set temperature + upper lower limit corrected temperature Here, if the upper upper limit temperature deviation is a positive value, it is detected by the upper temperature sensor 33 If the temperature is higher than the upper upper limit temperature and the upper upper limit temperature deviation is a negative value, the temperature detected by the upper temperature sensor 33 is lower than the upper upper limit temperature. The same applies to the upper and lower limit temperature deviation below.

The control device 40 includes an upper temperature deviation gradient calculating means for calculating an upper temperature deviation gradient from the upper temperature deviation calculated over time by the upper temperature deviation calculating means, and an upper temperature deviation gradient calculated by the upper temperature deviation gradient calculating means. and an upper prediction time calculation means for calculating an upper upper limit temperature prediction time or an upper lower limit temperature prediction time at which the upper temperature in the firing furnace 20 becomes the upper upper limit temperature or the upper lower limit temperature.

These upper temperature deviation gradient, upper upper limit temperature prediction time, and upper lower limit temperature prediction time are calculated by the following equations.
Upper temperature deviation gradient (K/min)
= 60 seconds/10 seconds x (latest top temperature deviation - top temperature deviation 10 seconds ago)
Upper limit temperature prediction time (seconds) = 60 x (-upper upper limit temperature deviation) / upper temperature deviation gradient Upper lower limit temperature prediction time (seconds) = 60 x (- upper lower limit temperature deviation) / upper temperature deviation gradient Here, upper If the upper limit temperature prediction time is a positive value, it means that the upper limit temperature will be reached after x seconds, and if it is a negative value, it means that the upper limit temperature was reached x seconds before, and the upper limit temperature prediction time is The same is true for Each of the above data is calculated every second from the detected temperature of the upper temperature sensor 33 which is input to the control device 40, and each calculated data is stored in the memory for 40 seconds.

In order to acquire the lower temperature control information, the control device 40 calculates the upper temperature deviation, the upper upper limit temperature deviation, the upper lower limit temperature deviation, the upper temperature deviation gradient, and the upper upper limit temperature prediction time when acquiring the upper temperature control information. And similarly to the upper and lower limit temperature prediction time, lower temperature deviation, lower upper limit temperature deviation, lower lower limit temperature deviation, lower temperature deviation gradient, lower upper limit temperature prediction time and lower lower limit temperature prediction time are acquired, and each of these Data is calculated every second from the temperature detected by the lower temperature sensor 34 and input to the controller 40, and each calculated data is accumulated in the memory for 40 seconds.

Further, the control device 40 calculates the upper upper limit temperature deviation calculated by the upper upper limit temperature deviation calculating means or the upper lower limit temperature deviation calculated by the upper lower limit temperature deviation calculating means, and the upper upper limit temperature calculated by the upper prediction time calculating means. an upper determination means for determining, from the predicted time or the predicted time of the upper and lower limit temperature, the change state of temperature in which the temperature of the upper portion in the firing furnace 20 approaches or departs from the upper upper limit temperature or the upper lower limit temperature while increasing or decreasing; It has

The upper determination means will be described in detail with reference to FIGS. 5 and 6. FIG. FIG. 5 shows the upper and lower limit temperature deviation, the upper and lower limit temperature prediction time, the upper and lower limit temperature first to fourth The description of the upper part or the lower part of the state of change is omitted. Similarly, FIG. 6 shows the upper set temperature, the upper upper limit and lower temperature, the lower set temperature, the lower upper limit and the lower lower limit temperature, and the set temperature, upper limit and lower limit temperature shown in FIG. omits the description of the top or bottom. As shown in FIG. 5(a), in the upper determination means, in the relationship between the upper upper limit temperature deviation and the upper upper limit temperature prediction time, the upper upper limit temperature prediction time takes a positive value and the upper upper limit temperature deviation takes a positive value. The upper upper limit temperature first change state indicates a change state in which the upper temperature in the firing furnace 20 decreases and approaches the upper upper limit temperature (shown in A of FIG. 6), and the upper upper limit temperature prediction time is a negative value. The upper upper limit temperature second change state in which the upper upper limit temperature deviation takes a positive value indicates a change state in which the temperature of the upper part in the firing furnace 20 rises and departs from the upper upper limit temperature (shown in B of FIG. 6 ), the upper upper limit temperature prediction time is a negative value and the upper upper limit temperature deviation is a negative value. (shown in C of FIG. 6), the upper upper limit temperature prediction time is a positive value and the upper upper limit temperature deviation is a negative value. increases and approaches the upper upper limit temperature (shown in D in FIG. 6).

Next, as shown in FIG. 5B, in the relationship between the upper and lower limit temperature deviation and the upper and lower limit temperature prediction time, the upper and lower limit temperature prediction time is a positive value and the upper and lower limit temperature deviation is a positive value. The lower limit temperature first change state indicates a change state in which the upper temperature in the firing furnace 20 decreases and approaches the upper lower limit temperature (shown in E in FIG. 6), and the upper and lower limit temperature prediction time is a negative value. The upper and lower limit temperature second change state in which the upper and lower limit temperature deviation takes a positive value indicates a change state in which the temperature of the upper part in the firing furnace 20 rises and departs from the upper and lower limit temperature (shown in F of FIG. 6). , the upper and lower limit temperature prediction time is a negative value and the upper and lower limit temperature deviation is a negative value. (shown in G of FIG. 6), and the upper and lower limit temperature prediction time is a positive value and the upper and lower limit temperature deviation is a negative value. It shows a change situation in which the temperature rises and approaches the upper and lower limit temperature (shown in H in FIG. 6).

Similarly to the upper judging means, the lower upper limit temperature deviation and the lower upper limit temperature prediction time are classified into the lower upper limit temperature first to fourth change states, and the lower lower limit temperature deviation and the lower lower limit temperature prediction time are classified into the first to fourth change states. The relationship is classified into lower lower limit temperature first to fourth change states. In the above description of the upper determination means, the upper upper limit or upper lower limit temperature deviation in the upper determination means is replaced with the lower upper limit or lower lower limit temperature deviation in the lower determination means, and the upper upper limit or upper lower limit temperature prediction time in the upper determination means is determined by the lower determination. By replacing with the lower upper limit or lower lower limit temperature prediction time in the means, the lower determining means makes substantially the same determination as the upper determining means.

The control device 40 controls the temperature of the upper part of the firing furnace 20 based on the result of the upper determination that the temperature of the upper part of the firing furnace 20 approaches or departs from the upper upper limit or the upper lower limit temperature while the temperature of the upper part of the firing furnace 20 increases or decreases. temperature reaches the upper upper limit or upper lower limit temperature with an upper delay reference time set as a reference for the delay time due to thermal inertia, and comparing the upper judgment result with the upper comparison means A control means is provided for controlling on/off of the upper heater 31 based on the result of upper comparison by the means.

More specifically, as shown in Table 1, the control device 40 determines that the upper upper limit temperature first change state occurs, and the upper lower limit temperature prediction time (shown in A of FIG. 7) is used as the upper comparison condition. is longer than 240 seconds set as the upper delay reference time, the upper heater 31 is controlled to be turned off because the upper temperature in the firing furnace 20 is higher than the upper limit temperature and the temperature does not drop for a while. When the control device 40 determines that the upper limit temperature is in the second change state, it determines that the upper part in the firing furnace 20 is clearly higher than the upper upper limit temperature without applying the upper part comparison condition (unconditionally), The upper heater 31 is controlled to be turned off.

When the control device 40 determines that the upper upper limit temperature is in the third change state, it determines that the upper part in the firing furnace 20 is lower than the upper upper limit temperature without applying the upper upper limit comparison condition (unconditionally). If the heater 31 is on, the on state is maintained, and if it is off, the off state is maintained, and control is not performed to change the on/off state of the upper heater 31 . The control device 40 determines that the upper upper limit temperature is in the fourth change state, and the upper upper limit temperature prediction time (shown in D in FIG. 7) is the upper upper limit temperature prediction time (shown in D in FIG. 7) as the upper upper limit temperature change state, and the upper heater 31 is turned off. If it is determined that the time is shorter than 120 seconds, which is set as the reference time, it is determined that the temperature of the upper portion of the firing furnace 20 is rising and will soon reach the upper limit temperature, and the upper heater 31 is controlled to be turned off.

In addition, the control device 40 determines that the upper and lower limit temperature is in the first change state, and the upper and lower limit temperature prediction time (shown in E of FIG. 7) turns on the upper heater 31 as the upper comparison condition. If it is determined that the temperature of the upper part of the furnace 20 is shorter than 120 seconds, which is set as the upper delay reference time required for the temperature of the upper part of the inside to rise, the upper part of the baking furnace 20 is being cooled and will soon reach the upper limit temperature, so the upper heater 31 is turned on. control to When the control device 40 determines that the upper and lower limit temperature is in the second change state, it determines that the upper portion in the firing furnace 20 is higher than the lower limit temperature without applying the upper and lower temperature comparison condition (unconditionally), and the upper heater If the upper heater 31 is on, the on state is maintained, and if it is off, the off state is maintained, and control is not performed to change the on/off state of the upper heater 31 .

When the control device 40 determines that the upper and lower limit temperature is in the third change state, it determines that the upper part in the firing furnace 20 is clearly lower than the upper and lower limit temperature, and the upper heater 31 is turned on without applying the upper part comparison condition. control to turn on. The controller 40 determines that the upper upper limit temperature is in the fourth change state, and determines that the upper upper limit temperature prediction time (shown in H in FIG. 7) is longer than 240 seconds set as the upper delay reference time as the upper comparison condition. When determined, it is determined that the temperature in the upper part of the firing furnace 20 is lower than the upper limit temperature and will not rise to the upper upper limit temperature for a while, and the upper heater 31 is controlled to be turned on.

The control device 40 controls the temperature of the lower part of the firing furnace 20 based on the lower part determination result that the temperature of the lower part of the firing furnace 20 approaches or departs from the lower upper limit or the lower lower limit temperature while the temperature of the lower part of the firing furnace 20 increases or decreases. lower limit temperature prediction time at which the temperature reaches the lower upper limit or lower limit temperature with a lower delay reference time set as a reference for the delay time due to thermal inertia, and comparing the lower determination result with the lower comparison means A control means is provided for controlling on/off of the lower heater 31 based on the result of lower comparison by the means. The lower determination means has substantially the same determination conditions as the upper determination means, but the delay reference time for comparing the lower upper limit temperature prediction time or the lower lower limit temperature prediction time with the delay time due to the thermal inertia of the lower part of the firing furnace 20. For the lower comparison means with the lower delay reference time, the comparison conditions are different from those of the above-mentioned upper comparison means.

More specifically, as shown in Table 2, the control device 40 determines that the lower upper limit temperature first change state occurs, and the lower lower limit temperature prediction time (shown in A of FIG. 7) is used as the lower comparison condition. is longer than 60 seconds, which is set as the lower delay reference time, the lower heater 32 is controlled to be turned off because the lower temperature in the firing furnace 20 is higher than the upper limit temperature and the temperature does not drop for a while. . When the control device 40 determines that the upper limit temperature is in the second change state, it determines that the lower part in the firing furnace 20 is clearly higher than the lower upper limit temperature without applying the lower part comparison condition (unconditionally), It controls to turn off the lower heater 32 .

When the control device 40 determines that the lower upper limit temperature is in the third change state, it determines that the lower part in the firing furnace 20 is lower than the lower upper limit temperature without applying the lower part comparison condition (unconditionally). If the heater 32 is on, the on state is maintained, and if it is off, the off state is maintained, and control is not performed to change the on/off state of the lower heater 32 . The control device 40 determines that the lower upper limit temperature is in the fourth change state, and the lower upper limit temperature prediction time (shown in D in FIG. 7) is the lower upper limit temperature prediction time (shown in D in FIG. 7) as the lower upper limit temperature delay in which the lower heater 32 is heated by residual heat after the lower heater 32 is turned off. If it is determined that the time is shorter than 30 seconds, which is set as the reference time, it is determined that the temperature of the lower part in the kiln 20 is rising and will soon reach the lower upper limit temperature, and the lower heater 32 is controlled to be turned off.

In addition, the control device 40 determines that the lower lower limit temperature first change state exists, and the lower heater 32 is turned on after the lower lower limit temperature prediction time (shown in E in FIG. 7) as the lower comparison condition. If it is judged that the temperature of the lower part of the furnace 20 is shorter than 30 seconds, which is set as the lower part delay reference time required for the temperature of the lower part of the furnace to rise, the temperature of the lower part of the baking furnace 20 will soon reach the lower limit temperature, so the lower heater 32 is turned on. control to When the control device 40 determines that the lower lower limit temperature is in the second change state, it determines that the lower part in the firing furnace 20 is higher than the lower limit temperature without applying the lower lower limit comparison condition (unconditionally), and the lower heater If the lower heater 32 is on, the on state is maintained, and if it is off, the off state is maintained, and control is not performed to change the on/off state of the lower heater 32 .

When the control device 40 determines that the lower lower limit temperature is in the third change state, it determines that the lower part in the firing furnace 20 is clearly lower than the lower lower limit temperature without applying the lower lower limit comparison condition (unconditionally). , to turn on the lower heater 32 . The controller 40 determines that the lower upper limit temperature is in the fourth change state, and determines that the lower upper limit temperature prediction time (shown in H in FIG. 7) is longer than 60 seconds set as the upper delay reference time as the lower comparison condition. When determined, it is judged that the lower part in the kiln 20 is lower than the lower lower limit temperature and the lower upper limit temperature will not rise for a while, and the lower heater 32 is controlled to be turned on.

In the oven cooking apparatus 10 configured as described above, the control device 40 controls the upper limit or upper limit while the temperature of the upper part in the baking furnace 20 rises or falls from the upper detection temperature, which is the temperature detected by the upper temperature sensor 33 . A delay due to thermal inertia in the upper judgment result of judging the changing state of the temperature approaching or leaving the lower limit temperature and the upper upper limit or upper lower limit temperature prediction time when the upper temperature in the firing furnace 20 reaches the upper upper limit or upper lower limit temperature. An upper comparison result compared with an upper delay reference time set as a time reference is acquired, and the upper heater 31 is on/off controlled based on the upper determination result and the upper comparison result. Based on the result of comparison between the upper determination result, which is the change in the temperature of the upper part in the firing furnace 20, and the upper upper limit or upper lower limit temperature prediction time with the upper delay reference time set as the reference for the delay time due to thermal inertia. Since the heater 31 is controlled to turn on and off, it is possible to perform highly accurate heating control between the upper limit temperature and the lower limit temperature of the upper part of the baking furnace 20, which has large thermal inertia, by heating in the state of natural convection. become.

In addition, the control device 40 controls the temperature change state in which the temperature in the lower part of the baking furnace 20 approaches or departs from the lower detection temperature, which is the detection temperature of the lower temperature sensor 34, to the lower upper limit or the lower lower limit temperature while increasing or decreasing. and a lower delay reference time set as a reference for the delay time due to thermal inertia, the lower upper limit or lower lower limit temperature prediction time at which the temperature of the lower part in the firing furnace 20 reaches the lower upper limit or lower lower limit temperature. The lower heater 32 is on/off controlled based on the lower determination result and the lower comparison result. Based on the result of comparison between the lower judgment result obtained by judging the change in the temperature of the lower part in the firing furnace 20 and the lower upper limit or lower lower limit temperature prediction time with the lower delay reference time set as the reference for the delay time due to thermal inertia. Since the lower heater is controlled on and off by natural convection, the lower part of the firing furnace with large thermal inertia can be controlled with high accuracy between the upper limit temperature and the lower limit temperature. become.

In addition, since the inside of the firing furnace 20 is heated by natural convection by the upper and lower heaters 31 and 32, the thermal inertia and the way of heat transfer differ between the upper portion and the lower portion of the firing furnace 20. If the upper portion and the lower portion are heated and controlled with the same control setting, one of the upper portion and the lower portion of the kiln 20 may exceed the upper limit temperature and the lower limit temperature, resulting in large hunting. On the other hand, the upper delay reference time and the lower delay reference time can be set independently. can be set to a delay reference time according to the propagation of the heat, and both the upper and lower portions of the firing furnace 20 can be controlled with high accuracy between the upper limit temperature and the lower limit temperature.

DESCRIPTION OF SYMBOLS 10... Oven cooking apparatus, 20... Firing furnace, 31... Upper heater, 32... Lower heater, 33... Upper temperature sensor, 34... Lower temperature sensor, 40... Control device.

Claims (1)

a firing furnace for firing the food to be cooked;
an upper heater for heating the upper part of the firing furnace;
a lower heater for heating the lower part in the firing furnace;
an upper temperature sensor for detecting the upper temperature in the firing furnace;
a lower temperature sensor that detects the temperature of the lower part of the firing furnace;
The upper heater is controlled to turn on and off so that the temperature is between the upper limit temperature and the upper lower limit temperature, which are the upper limit and lower limit of the upper set temperature, which is the set temperature of the upper part of the baking furnace. a control device for controlling on/off of the lower heater so that the temperature is between the lower upper limit temperature and the lower lower limit temperature set as the upper limit and the lower limit of a certain lower set temperature,
An oven cooking apparatus that heats the inside of the baking furnace by natural convection with the upper and lower heaters,
The control device is
An upper detection result obtained by judging a temperature change state in which the temperature of the upper part of the firing furnace approaches or departs from the upper upper limit temperature or the upper lower limit temperature while increasing or decreasing from the upper detection temperature, which is the temperature detected by the upper temperature sensor. and an upper comparison result obtained by comparing the upper upper limit or upper lower limit temperature prediction time at which the upper temperature in the firing furnace reaches the upper upper limit or upper lower limit temperature with an upper delay reference time set as a reference for the delay time due to thermal inertia. and controlling on/off of the upper heater based on the upper determination result and the upper comparison result,
A result of determination of the lower part that determines the change in temperature in which the temperature in the lower part of the firing furnace approaches or departs from the lower upper limit temperature or the lower lower limit temperature while increasing or decreasing from the lower detection temperature, which is the temperature detected by the lower temperature sensor. and a lower comparison result obtained by comparing the lower upper limit or lower lower limit temperature prediction time at which the lower temperature in the firing furnace reaches the lower upper limit or lower lower limit temperature with a lower delay reference time set as a reference for the delay time due to thermal inertia. and controlling on/off of the lower heater based on the lower determination result and the lower comparison result,
An oven cooking apparatus, wherein each of the upper delay reference time and the lower delay reference time can be set independently.

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