JPS6340175Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a control device for a commercial electric automatic rice cooker that automates the start of rice cooking, the completion of cooking, reheating, and warming.

Commercial electric automatic rice cookers usually use three-phase alternating current as the power source. The purpose of the present invention is to provide a control device for a commercial electric automatic rice cooker that can advantageously utilize the three-phase AC heater to keep warm and automatically control reheating and keeping warm with a simple control circuit. .

Next, the present invention will be explained based on an embodiment shown in the drawings. 1 is three electric heater wires 1A, 1B, 1C
_S1 is a three-phase AC heater connected in delta and embedded in a spirally shaped disc-shaped cast object 10 to form a planar heating element as shown in FIG. _L1 is the power lamp that lights up when switch _S1 is closed, F is the fuse, and 2 is whether to automatically set the rice cooking start time or not (immediately).
21 is its automatic side terminal, 22 is its manual side terminal, _T1 is a timer for the time switch connected to the automatic side terminal 21 and is for setting the rice cooking start time, _a1 is its normally open contact, b ₁ is its normally closed contact, 31 is a temperature sensor placed in contact with the center of the bottom of food can A, and 3 is the input of the output of temperature sensor 31 and the output of rice cooking timer TC ₁ . 32 is a manual switch provided in the power supply circuit of the control circuit, and the electromagnetic relay 30 is energized by the manual changeover switch 2. Either the closing contact _b1 or the manual switch 32 can be selected. Automatic switching contact 4 has rice cooking terminal 41 and reheating side terminal 42
and a rice cooking electromagnetic switch relay 43 whose rice cooking terminal has a contact 4a inserted between the manual power switch _S1 and the heater 1, and a rice cooking lamp.
_L2 is connected, and the reheating side terminal 42 is connected to a manual changeover switch 5 for switching between automatic manual and stop of reheating and heat retention. A manual changeover switch 5 is connected to a terminal 51 to which an automatic reheating circuit 6 and a heat retention circuit 7 are connected to automatically perform reheating and heat retention, and an OFF switch to stop reheating and heat retention.
The automatic reheating circuit 6 has a terminal 52 and a manual terminal 53 for manually reheating, and a timer _T2 , which is a first time relay, is connected to the automatic reheating circuit 6. Timer T ₂ has a normally open contact A ₂ inserted into the reheating circuit 6 and a normally open contact A ₃ provided in the energizing circuit to timer T ₃ (described later), and the contact is closed after a set time elapses after input.
Close a ₂ and a ₃ . The timer T ₃ is a time relay, and has a normally closed contact B ₃ inserted in series with the contact A ₂ in the automatic reheating circuit 6 and a normally open contact A ₄ inserted in the warming circuit 7. After a set period of time after ₃ is closed, contact A ₄ is closed and contact B ₃ is opened. 9 is connected to the heat insulation circuit 7, and is a contact 9a for energizing the heater wire 1A.
This is an electromagnetic relay for heat retention that opens and closes the heater wire 1A, and _L3 is a heat retention lamp that lights up when the heater wire 1A is energized.

Close the manual power switch _S1 , connect the changeover switch 2 to the automatic side 21, connect the changeover switch 5 to the automatic side 51, and set the timer _T1 to a desired time. When the set time comes, contact _a1 closes and contact _b1 opens due to the action of timer _T1 . In this state, the control circuit 3 connects the switching contact 4 to the rice cooking side 41 because the temperature of the food can A is low, and the electromagnetic relay 43 is energized to close the contact 4a and light up the lamp _L2 . As a result, a three-phase alternating current of 200 volts and 15 amperes is applied to the heater 1, and the heat generated by the heater 1 causes rice to be cooked in the food can A.The output of the sensor 31 causes the bottom of the food can A to reach the set temperature (for example, 125°C). )
, and when the time set by the timer TC ₁ built into the control circuit 3 has elapsed, the switching contact 4 is connected to the reheating and warming side 42, and the electromagnetic relay 43 is de-energized and the contact is closed. 4a, the rice cooking by the heater 1 is stopped, and the timer T ₂ is switched from the reheating circuit 6 via the changeover switch 5.
Current is supplied to Also, timer T ₁ and timer T ₂
After a set time (for example, one minute) has elapsed, contacts a ₂ and a ₃ are closed, thereby energizing the electromagnetic relay 43 and closing contact 4 a again to perform reheating.
When contact a ₃ closes, timer T ₃ operates and the corresponding timer
After a set time of _T3 (for example, 5 minutes), contact _b3 opens and contact _a4 closes. As a result, reheating is stopped, and the electromagnetic relay 9 is energized and the contact 9
A is closed, electricity is started to be applied to the heater wire 1A, and the food can A is kept warm. For this heat retention, use manual selector switch 5.
This continues until the power is applied to the OFF terminal 42.

If you want to start cooking rice manually, press the manual power switch.
Close S ₁ and turn manual selector switch 2 to manual side 2.
Connect to 2. This will start cooking the rice, and reheating and keeping it warm will be done as before.

When reheating is performed manually, the changeover switch 5 is connected to the reheating side terminal 53. As a result, the electromagnetic relay 43 is energized via the reheating circuit 8, and reheating is performed for a desired time.

As described above, the control device for the commercial electric automatic rice cooker of the present invention uses one heating wire of a three-phase AC heater to keep warm, reheats with a timer, and uses a thermistor (temperature sensor) to keep warm. Since the heat retention is automatically controlled, it is possible to control the control device of a commercial electric automatic rice cooker with a simple control circuit, and rice cooking can be stopped using both the temperature sensor and timer TC ₁ . It is safe even when the temperature sensor fails.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a control device for a commercial electric automatic rice cooker according to the present invention, FIG. 2 is a plan view of a three-phase AC heater, and FIG. 3 is a front view of the commercial electric automatic rice cooker.

Claims (1)

[Scope of utility model registration request] A three-phase AC heater with three heater wires connected in delta, a time switch to set when to start energizing the heater, and when the food can reaches the set temperature or the time set by the timer has elapsed. It is equipped with a temperature switch that _stops power supply to the heater _when
A variable reheating circuit that re-energizes the heater for the time set by timer _T3 after the time set by timer _T2 has elapsed from the OFF operation, and a heat retention circuit that energizes only one heater wire of the heater after reheating is completed. A control device for a commercial electric automatic rice cooker consisting of: