JP2009011430A - Food heating warmer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To specify failed temperature sensor and heater when the temperature sensor and the heater for heating a plurality of placing sections for placing food and keeping them at a set temperature respectively fail. <P>SOLUTION: For the temperature control of the respective placing sections, the detected values of the temperature sensors of the respective placing sections are inputted to a control circuit. The control circuit judges that the temperature sensor failed when the detected value of the temperature sensor is abnormal and judges that the heater of the placing section whose temperature is detected by the temperature sensor failed when the detected temperature of the temperature sensor is abnormal further. Then, the lamp of the failed placing section among the lamps 44-61 of an operation panel 37 is made to flicker and a failed part is displayed at an error display device 68 by a code. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a food heating and warming device in which a placement unit such as a shelf is provided in a warming chamber, and the placement unit is heated by a heater to heat and heat the food placed on the placement unit.

  The food heating warmer is usually configured as a showcase (see, for example, Patent Documents 1 and 2), and is installed in a convenience store or the like. In the above-mentioned Patent Document 1, in a showcase having a refrigerated room and a warm room, hot plates (food placing portions) are arranged in a plurality of stages in the warm room, and the hot plate is heated by a heater to thereby form the hot plate. It is set as the structure which heat-heats the food mounted on the top.

Further, in Patent Document 2, in a showcase selling Chinese buns, etc., the inside of the storage room is heated by convection with air heated by the bottom heater, or a plurality of food placement shelves by heat conduction of the side heaters. In addition to heating the food, the steam generator is provided so that the steamed Chinese bun can be steamed by the steam generated from the steam generator.
JP-A-7-231835 Japanese Patent Laid-Open No. 2004-173797

2. Description of the Related Art In a food heating and warming device that heats and holds food by a hot plate method, a heater is provided for each of a plurality of hot plates. For this reason, when the heater is disconnected, only the hot plate having the disconnected heater loses the heating function. However, since other hot plates continue to function as a heat source, there is a problem that it is difficult for the store clerk to notice the hot plate failure.
Normally, the hot plate heater is controlled to be turned off and on by a thermostat that detects the temperature of the hot plate. It becomes high temperature.

  If the internal temperature is lower or higher than normal due to a hot plate failure, you will notice that the hot plate has failed, but even if you notice the failure, which hot plate has failed? It's hard to understand. If you touch the hot plate, you will find that the hot or cold hot plate has failed, but the hot plate that is functioning properly or the hot hot plate where the thermostat is contact welded. It is dangerous because you have to touch the plate.

  In Patent Document 2, a temperature sensor that detects the temperature of the warm room and a humidity sensor that detects humidity are provided, and the control device detects a failure of the temperature sensor and the humidity sensor. In the case of failure, the operation is stopped (see paragraphs “0159” to “0161”). However, when the control shown in Patent Document 2 is applied to the control of a food warmer equipped with a plurality of hot plates, a temperature drop or a temperature rise in the warm room can be detected. If the temperature drop is caused by the heater breakage, or if the heater breaks, it is impossible to detect which hot plate heater is broken.

  The present invention has been made in view of the above circumstances, and the purpose of the present invention is to generate a failure and the occurrence of a failure when a failure occurs in a food heating incubator that heats a food placing portion with a plurality of heaters. The object of the present invention is to provide a food heating and warming device that can notify the location of the food.

The present invention divides a placing portion for placing food into a plurality of sections, and for each of the plurality of sections, a heater for heating the section, a section temperature sensor for detecting the temperature of the section, and the above A constant temperature heating means configured to include a switching element that cuts and disconnects the heater according to the temperature detected by the section temperature sensor is provided, and the plurality of sections provided for the plurality of sections of the placement section are further provided. A failure detection unit that individually detects a failure of the constant temperature heating unit; and a notification unit that identifies and notifies the constant temperature heating unit of which the failure is detected by the failure detection unit among the plurality of constant temperature heating units. Located in a food heating incubator.
According to the above configuration, the failure detection unit detects which one of the plurality of constant temperature heating units has failed, and the notification unit identifies and notifies the failed constant temperature heating unit.

  According to the present invention, since the constant temperature heating means that has failed can be specified, when a failure occurs, it can be quickly dealt with.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The food heating and warming device 1 is for business use installed in a convenience store or the like, and has a warming chamber 3 that also serves as a showcase on a pedestal 2 as shown in FIGS. This warm room 3 includes a frame 4, side glasses 5 and 5 fixed to the left and right side surfaces of the frame 4, a ceiling plate 6 and a ceiling glass 7 fixed to the rear half and the front half of the ceiling surface of the frame 4. The frame 4 has two sliding doors 8 that are slidably provided between the left and right support columns 4a and 4a at the rear of the frame 4 and open and close the rear surface of the frame 4, and the frame 4 is slidably attached in the vertical direction. A sliding door 9 that opens and closes an inclined front surface is combined.

  The sliding door 8 is configured by fitting a glass plate inside the sash, and opens and closes the rear surface of the warming chamber 3. The sliding door 9 is also configured by fitting a slightly curved glass plate inside the sash, and opens and closes the front surface of the warming chamber 3. Therefore, the inside of the thermal storage 3 is configured such that the inside can be seen through the side glasses 5 and 5, the ceiling glass 7, and the slide doors 8 and 9. The sliding door 8 is opened and closed by a store clerk when selling the product, and the sliding door 9 is also opened and closed by the store clerk when cleaning the inside.

  A plurality of stages, for example, two metal shelf boards 10 to 13 on the left and right sides are provided in the warm room 3. These shelf boards 10-13 are used as the food mounting part together with the metal floor board 14 on the bottom surface of the storage room 3. The placing portion composed of the shelf boards 10 to 13 and the floor board 14 is divided into a plurality of sections. In this embodiment, the shelves 10 to 13 themselves constitute one section, and the floor board 14 is divided into two sections, a floor board left 14a and a floor board right 14b, at the center.

  A heater and a temperature sensor are disposed in each section of the placement unit. That is, for example, cord-shaped heaters 15 to 20 for heating the respective sections are arranged in a meandering manner on the back surface of the shelf plates 10 to 13 and the back surfaces of the floor plate left 14a and the floor plate right 14b. Accordingly, the shelf boards 10 to 13 and the floor board 14 function as hot plates, respectively, and heat the food placed on the top. In addition, on the back surfaces of the shelf boards 10 to 13 and the floor board left 14a and the floor board right 14b, mounting part temperature sensors (zone part temperature sensors) 21 to 26 for detecting the temperatures of the respective sections are arranged. Yes. Further, in the present embodiment, thermal fuses 27 to 32 that are blown when the temperature of each section exceeds a predetermined high temperature are arranged on the back surfaces of the shelf boards 10 to 13 and the floor board left 14a and the floor board right 14b. It is installed.

  Each of the placement portion temperature sensors 21 to 26 is connected to a control circuit (control means) 33 as shown in FIG. Moreover, each heater 15-20 is connected to the control circuit 33 via SSR34 as a switching element, respectively. And the control circuit 33 detects the temperature of the shelf boards 10-13 and the bottom left 14a, and the bottom right 14b from the detection signal of each mounting part temperature sensor 21-26, and each heater 15-20 according to the detected temperature. Is controlled through the SSR 34.

  Specifically, each of the placement unit temperature sensors 21 to 26 includes, for example, a thermistor whose resistance value changes according to the temperature. As shown in FIG. The terminal is connected to the positive power source + Vcc, and the other terminal is connected to the ground via the resistor 35. A common connection point between the placement part temperature sensors 21 to 26 and the resistor 35 is connected to the control circuit 33. For this reason, the control circuit 33 inputs the divided voltage of the common connection point of each mounting part temperature sensor 21-26 and the resistor 35 as a detection signal (voltage) of each mounting part temperature sensor 21-26.

  On the other hand, as shown in FIG. 7, the heaters 15 to 20 in each section of the placement unit are connected in series with a 100 V commercial power source 36, a phototriac 34 a of the SSR 34, and the temperature fuses 27 to 32. And the control circuit 33 detects the temperature of the shelf boards 10-13 and the bottom board left 14a, the bottom board right 14b from the detection signal of each mounting part temperature sensor 21-26, the detected temperature, each shelf board 10-13, and The set temperatures of the left and right shelf boards 14a and 14b are compared, the photodiode 34b of the SSR 34 is controlled according to the comparison result, the phototriac 34a is turned on and off, and the heaters 15 to 20 in each section of the mounting section are cut off. It is configured to electrify.

The set temperatures (target temperatures) of the shelf boards 10 to 13 and the floor board left 14a and the floor board right 14b can be set in three ways: standard, high and low. The standard, high, and low set temperatures of the respective sections (the shelf boards 10 to 13 and the floor board left 14a and the floor board right 14b) of the placement section are shown in FIG. Here, the left and right lower shelf boards indicate the floor board left 14a and the floor board right 14b.
In order to set the set temperatures of the shelf boards 10 to 13 and the floor board left 14a and the floor board right 14b to one of standard, high and low, an operation panel 37 provided on the back side of the base 2 shown in FIG. The temperature selection switches 38 to 43 are operated. That is, each time the temperature selection switches 38 to 43 are operated once, the set temperatures of the shelf boards 10 to 13 and the left side 14a and the right side 14b change from standard → higher → lower, It has come back to the standard.

  In the operation panel 37, the upper, lower, and standard lamps 44 to 49, 50 to 55, and 56 to 61 are arranged in three stages on the upper side of the temperature selection switches 38 to 43 from the top to the bottom. Has been. When a set temperature is selected by each of the temperature selection switches 38 to 43, a lamp indicating the selected set temperature is turned on.

  In addition to the power switch 62 and the buzzer off switch 63, the operation panel 37 further includes an operating lamp 64, an alarm lamp (alarm means) 65, a buzzer (alarm means) 66, an appropriate temperature lamp 67, an error indicator 68, and the like. Is provided. Among these, the error indicator 68 is composed of, for example, three seven-segment indicators, and displays the contents of the failure by a combination code of “E” and “number” shown in FIG. 13 as described later.

  In addition to the SSRs 34 for controlling the switching of the heaters 15 to 20, the lamps 44 to 61, 64, 65 and 67, the buzzer 66, the error A display 68 is connected via a drive circuit 69, and a power switch 62 and a buzzer off switch 63 are connected. Further, a door switch 70 and an indoor temperature sensor 71 are connected to the control circuit 33, and an illumination lamp 72 is connected to the drive circuit 69. In addition, although the illumination lamp 72 is for illuminating the inside of the thermal storage room 3, it is not illustrated in FIGS.

  The door switch 70 is for detecting the opening and closing of the slide door 9, and is provided in the base 2, for example, and is turned on when the slide door 9 is closed, and is turned off when the slide door 9 is opened. It has become. Moreover, the room temperature sensor 71 is provided on the upper part of the support | pillar 4b provided in the center part of the left-right direction of the rear surface of the flame | frame 4, and detects the temperature in the thermal storage chamber 3. FIG. The indoor temperature sensor 71 is also composed of a thermistor, similar to the mounting part temperature sensors 21 to 26, and both terminals are connected to the ground via a positive power source + Vcc and a resistor 73 as shown in FIG. A common connection point between the room temperature sensor 71 and the resistor 73 is connected to the control circuit 33.

  Next, the operation of the above configuration will be described. When the power switch 62 is turned on to turn on the power, the illumination lamp 72 is turned on, the SSRs 34 are turned on, and the heaters 15 to 20 are energized. The energization of the heaters 15 to 20 heats the shelf boards 10 to 13, the floor board left 14a, and the floor board right 14b. Then, when the temperature inside the warming chamber 3 reaches a predetermined temperature or higher, the indoor temperature sensor 71 detects this, and the control circuit 33 turns on the appropriate temperature lamp 67 to notify that the food can be put in.

The set temperatures of the shelf boards 10 to 13, the floor board left 14a, and the floor board right 14b are initially set to “standard”. Then, depending on the external temperature and the type of food (packaged food or beverage can, etc.), the temperature selection switches 38 to 43 are operated to set the temperature of the shelf boards 10 to 13, the floor board left 14a, and the floor board right 14b. I do.
The foods placed on the shelf boards 10 to 13, the floor board left 14a, and the floor board right 14b are turned off according to the temperature detected by the temperature sensors 21 to 26 in the heaters 15 to 20 in the respective sections of the placement parts. By this, it is heated and held at the set temperature. In the present embodiment, the control circuit 33 executes the temperature control routine of FIG. 8 every 1 second, for example. When the temperature control routine of FIG. 8 is entered, the control circuit 33 sequentially executes the temperature control of each section (the shelf boards 10 to 13, the floor board left 14a, and the floor board right 14b) of the placement section, and then performs the indoor temperature control and the door. Perform management. The contents of the temperature control, the room temperature control, and the door management in each section of the placement section are shown in FIGS.

The temperature control routine for each section of the placement unit shown in FIG. 9 maintains the shelf boards 10 to 13, the floor board left 14a, and the floor board right 14b at the set temperatures, and if a failure occurs, the occurrence of the failure and the failure This is to notify the user together with the location and the type of failure.
That is, when the temperature control routine of FIG. 8 is entered, the control circuit 33 first performs temperature control (step S1) of the left upper stage mounting portion, that is, the shelf board 10. In the temperature control of the shelf board 10, as shown in FIG. 9, the control circuit 33 first inputs a detection signal of the temperature sensor 21 of the shelf board 10 (step A1). Next, the control circuit 33 determines whether or not the temperature sensor 21 or the heater 15 of the shelf board 10 has failed based on the detection value of the temperature sensor 21 (step A2, step A3). If not, it is determined whether or not the temperature detected by the temperature sensor 21 is equal to or higher than the set temperature selected by the temperature selection switch 38 (step A4).

  When the detected temperature of the temperature sensor 21 is equal to or higher than the set temperature, that is, when the set temperature is standard (80 ° C. for the shelf board 10), when the temperature is 80 ° C. or higher, the control circuit 33 sends an OFF signal to the SSR 34. Is output to turn off the heater 15 (temperature control means; “YES” in step A4, step A5). When the temperature detected by the temperature sensor 21 is lower than the set temperature, that is, when the set temperature is standard (80 ° C.) and is lower than 80 ° C., the control circuit 33 outputs an ON signal to the SSR 34. The heater 15 is energized (temperature control means; “NO” in step A4, step A6).

  The shelf plate 10 is held at the set temperature by such power interruption of the heater 15. And the temperature control of the shelf board 10 by the power interruption of this heater 15 is similarly performed by the power interruption of the heaters 15-20 also about the other shelf boards 11-13, the floor board left 14a, and the floor board right 14b ( Steps S2 to S6 in FIG. In FIG. 8, the left middle stage mounting part is the left middle shelf 12, the left lower stage placing part is the floor board left 14a, the right upper stage placing part is the right upper stage shelf 11, and the right middle stage placing part is the right middle stage. The shelf board 13 and the lower right stage mounting part are the floor board right 14b.

  By the way, the food heating warmer 1 may break down during use. In this embodiment, the failure detection target is, firstly, means for heating and holding each section of the placement unit, that is, each of the shelf boards 10 to 13, the floor board left 14 a, and the floor board right 14 b, respectively, that is, A sensor circuit 74 that connects a series circuit of the temperature sensors 21 to 26 and the resistor 35 between the positive power source + Vcc and the ground, and each heater 15 to 20, the SSR 34, and each temperature fuse 27 to 32 are connected in series. The constant temperature heating means 76 is composed of a heater circuit 75. Second, a series circuit of an indoor temperature sensor 71 and a resistor 73 is a sensor circuit 77 that connects between the positive power source + Vcc and the ground.

  First, the failure of the constant temperature heating means 76 includes the disconnection / short circuit of the sensor circuit 74 including the disconnection / short circuit of the temperature sensors 21 to 26 itself (failure of the temperature sensor), the short circuit / disconnection of the SSR 34 and the heaters 15 to 20 themselves. This may be caused by a short circuit or disconnection of the heater circuit 75 (other failures). Such a failure of the sensor circuit 74 and a failure of the heater circuit 75 are detected by the control circuit 33 as failure detection means as follows.

  In other words, if a disconnection occurs in the temperature sensors 21 to 26 or the sensor circuit 74, the voltage of the positive power source + Vcc is directly input to the control circuit 33 as a detection signal of the temperature sensors 21 to 26 depending on the location of the disconnection. Or the ground potential is input as it is.

On the other hand, when the heater circuit 75 is in a short-circuited state, the heaters 15 to 20 are always energized without being cut off, resulting in an abnormally high temperature. On the contrary, if disconnection occurs in the heater circuit 75, the heaters 15 to 20 are always disconnected without being energized, and the temperature is abnormally decreased.
Therefore, the control circuit 33 enters the placement part temperature control routine, for example, the temperature control routine of the upper left shelf 10 and inputs the detection signal of the temperature sensor 21 (step A1). Next, the detection of the temperature sensor 21 is performed. It is determined whether or not the value is normal, that is, whether the voltage of the positive power source + Vcc or the ground potential is not reached (failure detection means; step A2). If the voltage of the positive power supply + Vcc or the ground potential is not reached, the control circuit 33 determines that the detected value of the temperature sensor 21 is normal (“YES” in step A2), and sets the sensor circuit 74 to have no failure.

  If the detected value of the temperature sensor 21 is the voltage of the plus power source + Vcc or the ground potential, the control circuit 33 determines that the temperature sensor 21 (sensor circuit 74) is out of order ("NO" in step A2), and stops heating. The SSR 34 is turned off and the heater 15 is turned off, and in order to notify the user of the failure, an alarm and display by the notification means, specifically, the three-stage temperature setting lamps 44, 50, All 56 are blinked, the appropriate temperature lamp 67 is turned off, the alarm lamp 65 is turned on, the buzzer 66 is sounded, and the error content is displayed on the error display 68 (notification control means; step A7). In this case, the error content display on the error indicator 68 is performed by E60, 61, 63 to 67 as shown in FIG. 13, but here, it is a failure of the temperature sensor 21 of the left upper shelf 10. , “E61” is displayed as a code.

  When it is determined that there is no failure in the sensor circuit 74 (“YES” in step A2), the control circuit 33 enters the failure detection of the heater circuit 75, and the temperature of each section of the placement unit is lower than the upper limit value or higher than the lower limit value. (Failure detection means; step A3). In addition, the upper limit temperature and the lower limit temperature of each section of the placement unit are determined as shown in FIG. When the detected temperature of the temperature sensor 21 is equal to or lower than the upper limit temperature (120 ° C.) or the lower limit temperature (50 ° C.) of the shelf board 10, the control circuit 33 determines that there is no failure in the heater circuit 75 (in step A3, “ YES ”), the process proceeds to temperature control in which the heater 15 is cut off according to the temperature detected by the temperature sensor 21 described above.

  When the temperature detected by the temperature sensor 21 exceeds the upper limit temperature of the shelf board 10 or is lower than the lower limit temperature, the control circuit 33 determines that the heater circuit 75 has a failure ("NO" in step A3) and turns off the SSR 34. Then, the heater 15 is turned off, and an alarm is displayed to notify the user of the failure. Specifically, all the temperature setting lamps 44, 50, and 56 for the shelf board 10 are flashed, the appropriate temperature lamp 67 is turned off, and an alarm is issued. The lamp 65 is turned on, the buzzer 66 is sounded, and an error is displayed on the error indicator 68 (notification control means; step A8). In this case, the error contents are displayed on the error display 68 by the code display of “E81” as shown in FIG.

The failure of the sensor circuit 74 and the failure of the heater circuit 75 as described above are similarly performed for each section of the placement unit other than the shelf board 10, and when a failure is detected, the same alarm and display are performed. Is made.
It should be noted that only the display corresponding to the last detected fault is displayed on the error display 68.

  As described above, when the sensor circuit 74 or the heater circuit 75 fails, the buzzer 66 sounds, so that the occurrence of the failure is immediately noticed. Note that the buzzer sound can be stopped by operating the buzzer off switch 63. Then, the user who notices the failure knows the failed mounting portion by blinking the temperature setting lamps 44 to 49, 50 to 55, and 56 to 61 as notification means. For example, if the temperature setting lamps 44, 50, and 56 are blinking, it is known that a failure has occurred in the constant temperature heating means 76 of the upper left shelf 10.

  Further, by looking at the code displayed on the error indicator 68 as a notification means, a failure occurs in any of the sensor circuit 74 including the temperature sensors 21 to 26 and the heater circuit 75 including the heaters 15 to 20. You can know what happened. For this reason, it becomes easy to find the failure position and the cause of the failure, and repair can be performed quickly.

  Now, in the temperature control routine of FIG. 8, when all the temperature control for the placement unit is completed, the control circuit 33 then shifts to the indoor temperature control (step S7). Failure detection of the sensor circuit 77 of the room temperature sensor 71 is performed in this room temperature control. That is, when shifting to the room temperature control, the control circuit 33 first inputs a detection signal of the room temperature sensor 71 as shown in FIG. 10 (step B1). Then, it is determined whether or not the detected value of the room temperature sensor 71 is normal.

  Since this indoor temperature sensor 71 constitutes a sensor circuit 77 similar to the placement portion temperature sensors 21 to 26, if there is a short circuit or a disconnection, the voltage of the positive power source + Vcc or the ground potential is used as a detection signal. Input to the control circuit 33. Therefore, if the detected value of the indoor temperature sensor 71 is not the voltage of the positive power source + Vcc or the ground potential, the control circuit 33 determines that there is no failure in the sensor circuit 77 (“YES” in step B2).

  When there is no failure in the sensor circuit 77, the control circuit 33 determines whether or not the temperature detected by the indoor temperature sensor 71 is not more than the upper limit temperature (step B3) and whether or not it is not less than the lower limit temperature (step B4). To do. When the detected temperature of the indoor temperature sensor 71 is not more than the upper limit temperature and not less than the lower limit temperature, the control circuit 33 determines that there is no abnormality and ends the indoor temperature control routine (“YES” in step B3, “ YES ”, return).

  When a failure occurs in the sensor circuit 77 including the indoor temperature sensor 71, the detection value of the indoor temperature sensor 71 becomes the voltage of the positive power source + Vcc or the ground potential, and therefore the control circuit 33 determines that the sensor circuit 77 is defective. (“NO” in step B2), an OFF signal is output to the SSRs 34 of all the heaters 15 to 20 serving as the heat insulation operation stop means to cut off all the heaters 15 to 20, and the appropriate temperature lamp 67 is turned off to turn off the buzzer. 66 is sounded, and the code of E30 (see FIG. 13) indicating the failure of the room temperature sensor 71 is displayed on the error display 68 (step B5).

  When the detected temperature of the indoor temperature sensor 71 exceeds the upper limit value (“NO” in step B3), the control circuit 33 cuts off all the heaters 15 to 20 in the same manner as described above, and sets the appropriate temperature lamp. 67 is turned off, the buzzer 66 is sounded, and the error display 68 displays a code of E20 (see FIG. 13) indicating a temperature abnormality (upper limit alarm) of the temperature-retaining chamber 3 (step B6).

  Further, when the detected temperature of the room temperature sensor 71 is less than the lower limit value (“NO” in step B4), the control circuit 33 turns off the appropriate temperature lamp 67, sounds the buzzer 66, and keeps the error indicator 68 on the warming room. The code display of E21 (refer to FIG. 13) indicating the temperature abnormality 3 (lower limit alarm) (hereinafter, alarm notification) is performed (step B7). When the temperature in the warming chamber 3 becomes lower than the lower limit temperature, the main cause is that the slide door 8 and the sliding door 9 remain open, and outside air enters the warming chamber 3 from there. It depends.

  For this reason, when the temperature in the thermal insulation 3 becomes less than the lower limit temperature, the heating and thermal insulation operation is continued as it is without disconnecting the heaters 15 to 20. And if the salesclerk who noticed opening of the sliding door 8 or the sliding door 9 by the ringing of the buzzer 66 closes this, the temperature in the temperature-retaining room 3 will rise and it will become more than a minimum temperature. Then, the control circuit 33 turns on the appropriate temperature lamp 67 when the indoor temperature sensor 71 detects a temperature equal to or higher than the lower limit temperature of the temperature-retaining room 3 by executing the subsequent step B4, and stops the buzzer 66 (already by the buzzer off switch 63). It is often stopped) and the code display of the error display 68 is turned off.

  As described above, when the sensor circuit 77 fails, or the temperature in the temperature keeping chamber 3 is abnormally high or abnormally low, an alarm is issued in the indoor temperature control routine, and the content of the failure is determined. It is displayed on the error display 68. For this reason, it is easy to investigate the cause of the failure, and the failure can be dealt with quickly. In addition, as the abnormally high temperature of the thermal storage 3, a short circuit of any one of the heater circuits 75 of the heaters 15 to 20 can be considered. In addition, the abnormally low temperature of the warming chamber 3 can be considered to hold the sliding door 9 open.

  When the indoor temperature control routine ends, the control circuit 33 goes to the door management routine (step S8). When the door management routine is entered, as shown in FIG. 11, the control circuit 33 determines whether or not the door switch 70 is on (closed) (step C1). If the slide door 9 is closed, the door switch 70 is in the ON state, so the control circuit 33 determines “YES” in step C1 and returns.

  When the door switch 70 is off, the control circuit 33 becomes “NO” in step S1, and displays “OP” on the error display 68 in the next step C2 (step C2). Due to the display of “OP”, the store clerk notices that the slide door 9 remains open, and closes the slide door 9.

  As described above, according to the present embodiment, when the constant temperature heating means 76 of the placement units (the shelf boards 10 to 13, the left side 14a and the right side 14b) fails, the constant temperature heating means of which placement part fails. Of the higher, standard, and lower lamps 44 to 49, 50 to 55, and 56 to 61 provided in the upper stage portions of the temperature selection switches 38 to 43 for setting the respective temperatures of the mounting portion, the failure Since the high, standard, and low lamps of the mounting unit are blinked, it is possible to know which mounting unit's constant temperature heating means has failed.

In addition, since the failure is indicated by the error indicator 65 at some point of the constant temperature heating means 76, the heater circuit including the heaters 15 to 20 is on the sensor circuit 74 side including the temperature sensors 21 to 26. You can know if it is on the 75th side.
For this reason, when repairing, the failure location and the cause of the failure can be easily identified, and the failure can be dealt with quickly.

In addition, in this embodiment, when a failure occurs, it is determined by the detection values of the temperature sensors 21 to 26 which side of the sensor circuit 74 and the heater circuit 75 of the constant temperature heating means 76 has failed. The circuit configuration is simple.
Furthermore, in this embodiment, when it determines with a failure by the detected value of the mounting part temperature sensors 21-26, only the heater of the mounting part determined to be failure is cut off, and other heaters continue energization. As a result, the heating and warming operation of the food heating and warming device 1 can be continued.

  The first problem that is predicted when the heating and heat insulation operation is continued even if the placement unit fails is that, for example, the SSR 34 of the heater circuit 75 of the failed placement unit has failed and the control circuit 33 is turned off to the SSR 34. Even if a signal is output, the heater is kept energized, resulting in an abnormally high temperature of the mounting portion. The problem of this abnormally high temperature is that the temperature fuses 27 to 32 are provided in the respective mounting portions. Therefore, even if the heaters 15 to 20 cannot be disconnected, the temperature use is increased if the mounting portion exceeds a certain temperature. Since the heater is cut off and the heater is cut off, it is safe. If the temperature fuse is not blown or if the heater cannot be cut off even if it is blown, the temperature inside the warming chamber 3 exceeds the upper limit temperature, and this is detected by the indoor temperature sensor 71. Causes the buzzer 66 to sound and the error indicator 68 to indicate that the upper limit temperature has been exceeded, so that the store clerk turns off the power switch 62 accordingly. Thereby, since the abnormally high temperature of a mounting part is prevented, further safety | security can be ensured.

In addition, a second problem that is predicted when the heat and heat retention operation is continued even if the placement unit fails is a reduction in the temperature of the product of the failed placement unit. About the failed mounting part, it becomes difficult to maintain the set temperature due to the power interruption of the heater. However, the food in the failed mounting part can also be maintained at an appropriate temperature by maintaining the inside of the greenhouse 3 at an appropriate temperature. Then, when the temperature in the warming chamber 3 becomes lower than the lower limit temperature, this is detected by the indoor temperature sensor 71 and the buzzer 66 is sounded, and the error indicator 68 displays less than the lower limit temperature. Then, the store clerk turns off the power switch 62 to stop the operation of the food heating incubator 1 and stop the sales of food. Thereby, generation | occurrence | production of the malfunction by which the foodstuff which is not heated to appropriate temperature is sold can be prevented.
In addition, in this embodiment, since the set temperature of each placement unit can be set higher and lower than the standard, it is optimal by changing the set temperature of the placement unit according to the form of the food to be placed and the external temperature. It can be set to a proper heat insulation temperature.

The present invention is not limited to the embodiment described above and shown in the drawings, and can be expanded or modified as follows.
The switching element is not limited to SSR, and may be a triac alone or an IGBT.
When all the heaters 15 to 20 are cut off in Steps B5 and B6, the power switch may be constituted by electric and electronic parts that can be controlled by the control circuit 33 such as SSR, and the power switch may be turned off.

1 is a front view of an operation panel according to an embodiment of the present invention. A perspective view of a food heating incubator as seen from the front side A perspective view of a food heating incubator as seen from the back side Sectional drawing which follows the AA line of FIG. Sectional drawing which follows the BB line of FIG. Block diagram showing electrical circuit configuration Circuit diagram showing specific configuration of sensor circuit and heater circuit Flow chart showing the contents of temperature control Flow chart showing contents of temperature control of mounting unit Flow chart showing the contents of indoor temperature control Flow chart showing details of door management (A) is a figure which shows the set temperature of 3 steps | paragraphs of each division of a mounting part, (b) is a figure which shows the upper limit temperature and lower limit temperature of a mounting part and a storage chamber. Diagram showing the relationship between code display and failure details

Explanation of symbols

  In the drawings, 10 to 13 are shelf boards (mounting parts), 14 is a laying board (mounting part), 15 to 20 are heaters, 21 to 26 are mounting part temperature sensors (zone temperature sensors), and 33 is a control circuit. (Failure detection means), 34 is SSR (switching element, heating stop means, heat insulation operation stop means), 44 to 49, 50 to 55, 56 to 61 are temperature setting lamps (notification means), 68 is an error indicator ( Notification means), 71 is an indoor temperature sensor, 74 is a sensor circuit, 75 is a heater circuit, 76 is a constant temperature heating means, and 77 is a sensor circuit.

Claims (5)

In a food heating and warming device provided with a placing part for placing food in a warming chamber,
The placement section is divided into a plurality of sections, and a heater for heating the section, a section temperature sensor for detecting the temperature of the section, and a detection temperature of the section temperature sensor are divided into the plurality of sections. In response, a constant temperature heating means configured to include a switching element that cuts off the heater is provided,
Furthermore, failure detection means for individually detecting a failure of the plurality of constant temperature heating means provided for the plurality of sections of the placement unit,
A food heating incubator comprising a notification means for specifying and notifying a constant temperature heating means in which a failure is detected by the failure detection means among the plurality of constant temperature heating means. The failure detection means can detect the content of the failure based on the input value of the ward temperature sensor, and can be divided into a failure of the ward temperature sensor and other failures,
2. The notification means, in addition to specifying and notifying the constant temperature heating means in which a failure is detected by the failure detection means, notifying the content of the failure detected by the failure detection means. The food heating incubator described.   The heating stop means for stopping energization of the heater of the constant temperature heating means in which the failure is detected when the failure detection means detects a failure of the constant temperature heating means. The food heating and warming device according to 1 or 2. An indoor temperature sensor that detects the temperature in the warming chamber, and a heating and warming operation stopping unit that stops energization of the heaters of all the constant temperature heating units are provided,
When the detected temperature of the indoor temperature sensor exceeds a predetermined upper limit temperature, the heating and heat insulation operation stopping means stops energization of all the constant temperature heating means to the heater, and the notification means notifies the failure. The food heating and warming device according to any one of claims 1 to 3. An indoor temperature sensor is provided for detecting the temperature in the warming room,
When the indoor temperature sensor detects a temperature lower than a predetermined lower limit temperature, a warning notification is issued by the notification means. Thereafter, when the internal temperature sensor detects the predetermined lower limit temperature or more, the warning by the notification means is issued. The food heating and warming device according to any one of claims 1 to 4, wherein the notification is stopped.

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