JPH035765Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention automatically starts cooking based on the detection result of the temperature probe when the jack of the temperature probe that detects the temperature of the food to be cooked is connected to the plug. However, the present invention also relates to a cooking appliance such as an oven range or a microwave oven that is configured to automatically start cooking using a timer when a temperature probe jack is not connected.

[Prior art]

In cooking devices such as oven ranges and microwave ovens,
Both the function to set the heating time and cook the food to be cooked (hereinafter referred to as time cooking) and the function to cook by setting the temperature of the food to be cooked, that is, the finished cooking temperature (hereinafter referred to as temperature cooking). There are many configurations that can be used depending on the food to be cooked or the type of cooking.

By the way, as a method of measuring the finished temperature of the food to be cooked, a configuration is known in which a temperature probe is inserted into the food to be cooked and the temperature is directly measured.
In such a configuration, a switch is provided to change over between time cooking and temperature cooking, but if this switch is turned on incorrectly, for example, even though the timer has been set for very short heating, the changeover switch will not switch to temperature cooking. If the switch is set to the slow cooking side, long-term heating will be performed, and if the switch is set to the slow cooking side, high-temperature heating will be performed. There was something to be done.

In order to avoid such a situation, for example, Japanese Patent Publication No. 57-33478 has been proposed. This invention is
The above-mentioned problems are solved by providing a switch that is switched by inserting a temperature probe into the plug of the jack to detect the temperature of the food to be cooked, and thereby automatically switching between temperature cooking and time cooking. It's on.

FIG. 3 shows an example of the configuration of a conventional cooking appliance in which switching between time cooking and temperature cooking is performed by inserting the plug of the temperature probe into the jack.

In this example, the commercial power supply 1 includes a fuse 2, a start switch 3 for instructing the start of cooking, a normally closed contact Jb ₁ of a first jack switch JS ₁ placed in the jack into which the temperature probe plug is to be inserted,
When the timer relay TM closes, the timer relay TM starts timing, and when the timer relay TM finishes timing, the timer relay TM opens, and the normally open timer switch TMa, which has a limited time, a heating circuit 9 such as a heater or high-frequency heating device, and the food to be cooked are housed. A series circuit is connected to the power source 1 through a door switch 10 that is closed when the cooking chamber door is closed, and a heating circuit 9 is connected.
Timer switch TMa side end and door switch 10
Connect a series circuit consisting of the normally closed contact Jb ₂ of the second jack switch JS ₂ and the timer relay TM placed in the jack in which the temperature probe plug is to be inserted between the power supply 1 side end of the Normally closed contact Jb ₁ side end and timer switch TMa heating circuit 9
Normally open contact of jack switch JS ₁ between side end Ja ₁
A series circuit consisting of the normally open contact 12a of the electromagnetic relay 12 is connected, and the normally open contact 12 of the normally open contact Ja ₁ is connected.
The a-side end is connected to a power supply 1 via a control transformer 4 , and the voltage stepped down by the control transformer 4 is rectified by a control power supply circuit 5 and applied to a temperature control circuit 11 .

The temperature control circuit 11 operates the relay coil 1 according to the detection result of the temperature of the food to be cooked by the temperature probe.
It controls the excitation and demagnetization of 2C, and a thermistor 6 (built in the temperature probe) is connected to both output terminals of the control power supply circuit 5, and when the temperature probe plug is inserted into the jack, the A voltage divider circuit consisting of a circuit as shown) and a resistor R ₁ ,
A voltage dividing circuit consisting of a resistor R ₂ , a variable resistor R ₃ and a resistor R ₄ and a series circuit of the coil 12C of the electromagnetic relay 12 and the switch transistor 13 are connected in parallel,
The intermediate potential of the voltage divider circuit consisting of thermistor 6 and resistor _R1 is connected to one input terminal of comparator 7, and the output of variable resistor _R3 is connected to the + input terminal of comparator 7.
Connect the output resistance of flip-flop 8 to the set terminal S
In addition, the reset terminal R of the flip-flop 8 is connected to the + side output terminal of the control power supply circuit 5, and the output terminal Q of the flip-flop 8 is connected to the base of the switch transistor 13.

With this configuration, when the temperature probe is not used, that is, when cooking for hours, the temperature probe plug is not inserted into the jack.
Normally closed contacts Jb ₁ , Jb ₂ of double jack switches JS ₁ , JS ₂
are both closed. Therefore, by setting the heating time in the timer TM and closing the timer switch TMa and the start switch 3, power is supplied to the heating circuit 9 and the timer relay TM. As a result, the detection circuit 9 heats the food to be cooked, the Timer Relay TM starts timing, and when the set time has elapsed, the Timer Relay TM opens its timer switch TMa and stops supplying power to the heating circuit 9. do.

On the other hand, when using a temperature probe, that is, when performing temperature cooking, the plug of the temperature probe is inserted into the jack, so both jack switches JS ₁ ,
The normally closed contacts Jb ₁ and Jb ₂ of JS ₂ are both closed, and the normally open contact Ja ₁ of the first jack switch JS ₁ is closed. Therefore, even if the timer switch TMa is operated, power is not supplied to the heating circuit 9 and the timer relay TM. On the other hand, when the start switch 3 is operated, power is supplied to the temperature control circuit _{11 by closing the normally open contact Ja 1 of} the first jack switch JS 1, so that the normally open contact 12a is closed by the electromagnetic relay 12 and the heating circuit 9, the heating circuit 9 heats the food to be cooked. That is, the resistance value of the thermistor 6 provided in the temperature probe is large when the food to be cooked is at a low temperature, so the voltage at the negative input terminal of the comparator 7 is initially lower than the voltage at the positive input terminal, and The output becomes a high level, and the Q output of the flip-flop 8 to which this is input becomes a high level. As a result, the switch transistor 13 becomes conductive, the coil 12C of the electromagnetic relay 12 is energized, the normally open contact 12a is closed, and the heating circuit 9
Powered by When the food to be cooked is heated to a predetermined temperature, the resistance of the thermistor 6 becomes small, the output of the comparator 7 is reversed to low level, the flip-flop 8 is reset, and its Q output becomes low level. Normally open contact 12 of electromagnetic relay 12
A opens and heating ends.

[Problems that this invention attempts to solve]

However, the above-mentioned configuration requires two jack switches (three contacts), which causes problems such as increased manufacturing costs and a high failure rate.

[Means for solving problems]

The present invention was developed in view of the circumstances described above, and includes a contact that short-circuits the timer switch, which is closed by inserting the temperature probe plug into the jack during temperature cooking, and cuts off the power supply to the timer relay. By providing only one jack switch with a contact point, the number of jack switches that are opened and closed by inserting the temperature probe plug into the jack is reduced compared to the conventional method, thereby reducing manufacturing costs and failure rates. The purpose of the present invention is to propose a cooker that can save power by eliminating wasteful power supply to the timer relay, and can extend its lifespan.

〔Example〕

Hereinafter, the present invention will be explained in detail based on drawings showing embodiments thereof.

FIG. 2 is a schematic external view of the cooking device according to the present invention (hereinafter referred to as the device of the present invention).The right side of the front is equipped with an operation panel 51 equipped with a temperature control knob 55, etc. An electric circuit (see FIG. 1), which will be described later, is provided. Further, a cooking chamber door 53 is pivotally attached to the left side of the front surface, and a cooking chamber 52 for storing and heating the food to be cooked is formed at the rear portion when the cooking chamber door 53 is closed.

The inner wall of the cooking chamber 52 is provided with a jack 63 into which a plug 62 of a temperature probe 61 containing a thermistor 6 is inserted.
is equipped with a jack switch JS, which will be described later.

FIG. 1 is a circuit diagram showing the configuration of the electric circuit of the present device, and the same members as in the conventional configuration shown in FIG. 3 are given the same reference numerals.

One line of commercial power supply 1 has fuse 2,
A start switch 3 for instructing the start of cooking, a normally open timer switch TMa that has a time limit for closing the timer relay TM, which is closed when the timer relay TM starts measuring time, and is opened when the timer relay TM finishes timing, and a temperature control circuit 11 electromagnetic relay 12
A normally closed contact 12b that opens when energized, a heating circuit 9 such as a heater or high-frequency heating device, and a door switch 1 that closes when the cooking chamber door 53 is closed.
A series circuit is connected to the other line of the power supply 1 via the line 0 and the other line of the power supply 1.

The start switch 3 side end of the timer switch TMa is connected to one end of the normally open contact Ja of the jack switch JS, and the heating circuit 9 side end is connected to the other end of the normally open contact Ja. A parallel circuit is formed with the contact Ja, and the heating circuit 9 side end of the timer switch TMa is also connected to one end of the normally closed contact Jb of the jack switch JS, and the other end of this normally closed contact Jb is connected via the timer relay TM. It is connected to the other line of the power source 1. These normally open contacts Ja and normally closed contacts Jb
The plug 62 of the temperature probe 61 is connected to the jack 63.
When inserted into the circuit, the circuit closes or opens, respectively.

Furthermore, the power supply 1 of the normally closed contact 12b of the electromagnetic relay 12
Between the side end and the power supply 1 side end of the door switch 10,
A control transformer 4 is connected in parallel with the heating circuit 9. A control power supply circuit 5 is connected to the secondary side terminal of the control transformer 4, and both output terminals of the control power supply circuit 5 which output direct current are built into a temperature probe 61, and when the jack is inserted into the plug, Thermistor 6 and resistor R ₁ are configured as shown in the circuit.
a voltage dividing circuit consisting of a resistor R ₂ , a variable resistor R ₃ whose resistance value is changed and set by the temperature control knob 55 mentioned above, and a resistor R ₄ connected in series;
The series circuits of the switch transistor 13 and the coil 12C of the electromagnetic relay 12 are connected in parallel, and the intermediate potential of the voltage divider circuit consisting of the thermistor 6 and resistor _R1 is connected to the − input terminal of the comparator 7, and the other The intermediate potential of the voltage divider circuit is connected to the +input terminal of a comparator 7, and the output terminal of this comparator 7 is connected to a set terminal S of a flip-flop 8. The reset terminal R of this flip-flop 8 is connected to the output terminal of the control power supply circuit 5, and the output terminal Q of the flip-flop 8 is connected to the switch transistor 13.
connected to the base of.

The operation of the device constructed as above will be explained below.

Temperature probe 61 is not used during time cooking. That is, since the plug 62 of the temperature probe 61 is not inserted into the jack 63, the normally open contact Ja of the jack switch JS is open, the normally closed contact Jb is closed, and the thermistor 6 is also not connected to the temperature control circuit 11. Therefore, if you turn on the timer switch TMa and start switch 3 after setting the heating time on the timer relay TM, the start switch 3, timer switch TMa, and jack switch JS will turn on.
Power is supplied to the timer relay TM through the normally closed contact Jb of the timer relay TM, and the timer relay TM starts measuring time.

On the other hand, start switch 3, timer switch
The control transformer 4 is also energized via TMa, thereby supplying power to the temperature control circuit 11. However, in this case, since the temperature probe 61 is not used, the thermistor 6 is not connected to the temperature control circuit 11, and its resistance value becomes infinite. Therefore, the input potential to the - input terminal of the comparator 7 is lower than the input potential to the + input terminal. Therefore, the output of the comparator 7 becomes high level and is applied to the set terminal S of the flip-flop 8, and the Q output of the flip-flop 8 is maintained at a high level, so that the switch transistor 13 becomes non-conducting and becomes an electromagnetic relay. Twelve coils 12C remain demagnetized. As a result, the normally closed contact 12b of the electromagnetic relay 12 is maintained in its closed state, so that the power supply 1, the start switch 3, the timer switch
Power is supplied to the heating circuit 9 via TMa and the normally closed contact 12b, and the food to be cooked is heated. Then, when the time set in the timer TM has elapsed, the timer switch TMa is opened, power supply to the heating circuit 9 is stopped, and heating ends.

On the other hand, when performing temperature cooking, the plug 62 of the temperature probe 61 is inserted into the jack 63. As a result, the normally open contact Ja of the jack switch JS is closed and the normally closed contact Jb is opened, so the power supply to the timer relay TM is cut off and the timer relay TM does not operate, and the timer switch TMa
operation will also be disabled. Next, after sticking the tip of the temperature probe 61 into the food to be cooked,
When the temperature control knob 55 connected to R ₃ is operated to set the cooking temperature according to the food to be cooked, the input potential to the + input terminal of the comparator 7 is set by the variable resistor R ₃ correspondingly. .

Then, when start switch 3 is operated,
Initially, the temperature of the food to be cooked detected by the temperature probe 61 is low, so the resistance of the thermistor 6 is high, and as described above, the switch transistor 13 becomes non-conductive and power is supplied to the heating circuit 9, so that the food to be cooked is heated. heated. Eventually, when the temperature of the food to be cooked reaches the temperature set by the variable resistor _R3 , the input potential to the - input terminal of the comparator 7 becomes higher than the input potential to the + input terminal. As a result, the output of the comparator 7 changes to a low level and is applied to the flip-flop 8, the output terminal Q of the flip-flop 8 also changes to a low level, and the switch transistor 13 becomes conductive. Therefore, the electromagnetic relay 12 is excited, its normally closed contact 12b is opened, the power supply to the heating circuit 9 is stopped, and the heating cooking is completed.

〔effect〕

As detailed above, in the cooker according to the present invention, it is possible to automatically switch between temperature cooking and time cooking depending on whether or not the temperature probe plug is inserted into the jack. The number of switches that operate to switch between time cooking and temperature cooking can be reduced compared to conventional configurations. Therefore, it is possible to reduce manufacturing costs, reduce the failure rate, and so on. When the temperature probe is inserted into the jack, the power supply to the timer relay TM is cut off, thereby eliminating unnecessary power consumption. Further, the life of the timer relay will not be shortened due to unnecessary energization of the timer relay.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention.
The figure is an electric circuit diagram of a cooking appliance according to the present invention, FIG. 2 is a schematic external view of the cooking appliance of the invention, and FIG. 3 is an electric circuit diagram of a conventional cooking appliance. 3...Start switch, 9...Heating circuit, 1
1... Temperature control circuit, 12... Electromagnetic relay, JS...
…Jack switch, TM…Timer, TMa…
...Timer switch.

Claims (1)

[Claims for Utility Model Registration] When a plug of a temperature probe that measures the temperature of the food to be cooked is inserted into a predetermined jack, based on the detection result of the temperature probe, the plug is not inserted into the jack. In this case, a timer switch that is opened when the timer relay finishes timing, and a plug for the temperature probe are inserted in a cooker that controls the heating circuit based on the timing results of the timer relay to heat and cook the food to be cooked. the timer switch is interposed between the power source and the heating circuit, the normally open contact is connected in parallel with the timer switch, and the normally closed contact is connected to the timer relay. A cooking device characterized in that the cooking device is interposed in a power supply circuit to the cooking device.