JPH0526099B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a gas combustion control device that can be suitably implemented in a cooking appliance such as a gas microwave oven.

BACKGROUND ART For example, in a gas cooker, food to be cooked is stored in a heating chamber, and the food in the heating chamber is heated by a plurality of burners. Such foods are generally heated in a range of 50°C to 320°C. In the prior art, all burners are ignited and extinguished at the same time, and this series of operations is repeated so that the temperature detected by a temperature detection means such as a thermostat becomes a predetermined set temperature. In particular, the temperature within the heating chamber is maintained at the set temperature as much as possible.

In such prior art, when trying to maintain the temperature inside the heating chamber at a relatively low set temperature, for example, 100 degrees Celsius or less, the temperature inside the heating chamber decreases due to combustion control by simultaneously igniting or extinguishing all burners. Large variations in distribution occur.

Purpose An object of the present invention is to provide a gas combustion control device for a cooker that can perform heating with uniform temperature distribution even if the heating temperature is relatively low.

Configuration In the present invention, the plurality of gas burners 2 to 6 are divided into a first group B1 with a small amount of heat generated and a first group B1 with a small amount of heat generated.
The heating chamber 1 is
In the gas combustion control device for a cooker that heats an object to be heated 15 in a cooker, a first solenoid valve M1 supplies/cuts off fuel gas to the gas burners 2 to 6 of the first and second groups B1 and B2; A second solenoid valve M2 that supplies/cuts off fuel gas to the gas burners 2 in group B1; A third solenoid valve M3 that supplies/cuts off fuel gas to gas burners 3 to 6 in second group B2; and gas burners in first group B1. ignition means 11 for igniting gas burners 2 of the first group B1; flame detection means 12 for detecting the presence or absence of ignition of the gas burners 2 of the first group B1; and combustion exhaust gases from the gas burners 2 to 6 of the first and second groups B1 and B2 are guided. Heating chamber 13
A fan 14 for keeping the temperature constant inside the heating chamber 13, and a temperature detection means 16 for detecting the temperature of the heating chamber 13.
and a temperature setting means 19 for setting a set temperature T at which the inside of the heating chamber 13 is to be heated; If so, first the first and second solenoid valves M1, M2
and close the third solenoid valve M3 to start the ignition means 1.
(a) When ignition is detected by the flame detection means 12, the fan 14 is rotated, (a1) the third solenoid valve M3 is opened, and the temperature is lowered from the set temperature T by the temperature detection means 16. When a temperature higher than a predetermined first value is detected for the first time after ignition, the second and third solenoid valves M2 and M3 are closed, and the fan 14 is stopped.
(a2) Thereafter, when the temperature detecting means 16 detects a temperature lower than the set temperature T by a predetermined second value, the second solenoid valve M2 is opened and the fan 14
(a3) when the temperature detecting means 16 detects a temperature higher than the set temperature T by a predetermined first value; , a second operation is performed in which the second solenoid valve M2 is closed, the fan 14 is stopped, and the third solenoid valve M3 is kept closed, and the first and second operations (a2),
(a3) is repeated, and (b) when ignition is not detected by the flame detection means 12, the first and second solenoid valves M
1, a first control means that closes M2 and issues an alarm, and a second control means that, when the temperature T set by the temperature setting means 19 exceeds a predetermined reference value, The ignition means 11 is started by opening the solenoid valves M1 and M2 and closing the third solenoid valve M3.
(c) When ignition is detected by the flame detection means 12, the fan 14 is rotated; (c1) the third solenoid valve M3 is opened; When a temperature higher than the first value determined is first detected after ignition, the second and third values are detected.
Close the solenoid valves M2 and M3 and stop the fan 14, (c2)
Thereafter, when the temperature detecting means 16 detects a temperature lower than the set temperature T by a predetermined second value, a third operation of opening the second and third solenoid valves M2 and M3 and rotating the fan 14 is performed. (c3) When the temperature detecting means 16 detects a temperature higher than the set temperature T by a predetermined first value, the second and third solenoid valves M2 and M3 are closed and the fan 14
performs a fourth operation to stop the ignition, and repeats the third and fourth operations (c2) and (c3), and (d) when ignition is not detected by the flame detection means 12, the first and second solenoid valves M1, and a second control means for closing M2 and issuing an alarm, the second value being selected to be larger than the first value.

Effect According to the present invention, the plurality of gas burners 2 to 6 are
They are grouped into a first group B1 and a second group B2 which generates a larger amount of heat,
Preset temperature T is a predetermined reference value (for example, 100℃)
In the case of a low temperature range below, all burners 2 to 6 are ignited only during the first temperature increase, and during subsequent temperature adjustment, only the gas burner 2 of the first group B1 is controlled on-off, and the setting When the temperature T is in a high temperature range exceeding the reference value, all burners 2
6 are on-off controlled, and in this way, the temperature of the heating chamber 13 is quickly raised to a desired temperature. A fan 14 is provided in the heating chamber 13. Rotate the heating chamber 1
It is possible to reduce the range of temperature fluctuation within the heating chamber 13, and to uniformly heat the food to be cooked, such as meat or fish, to the center of the heating chamber 13, where heat is difficult to conduct.

Further, according to the present invention, when the flame detection means 12 does not detect the ignition of the gas burners 2 of the first group B1, the first and second solenoid valves M1 and M
2 is closed and an alarm is issued. In this way, the gas burners 2 of the first and second groups B1 and B2
Safety can be ensured by cutting off the supply of fuel gas to 6 to 6.

Furthermore, according to the present invention, the second value set lower than the set temperature T is selected to be larger than the predetermined first value set higher than the set temperature T. In a cooking device such as a microwave oven, the inside of the heating chamber 13 is separated from the atmosphere;
3, the temperature decrease rate is slower than the temperature increase rate, and therefore it takes a relatively long time for the temperature to decrease by the second value from the set temperature T, and the gas burner is not ignited during this period. . Further, since the means for raising the temperature from the set temperature T to the first value is relatively short, it is sufficient to ignite the gas burner for such a short period of time. In this way, the combustion time can be shortened as much as possible while keeping the temperature fluctuation width as small as possible, and the amount of gas fuel consumed can be saved.

Embodiment FIG. 1 is a system diagram of an embodiment of a gas cooker 1 according to the present invention. The burners constituting the combustion section of this cooking device 1 are grouped into a plurality of groups, and include a first group B1 and a second group B2. The first group B1 consists of a single burner 2 and the second group B2 consists of four burners 3, 4, 5, 6. Fuel gas such as city gas is passed through a strainer 7 and adjusted to a predetermined pressure by a governor 8. This regulated gas passes through the solenoid valve M1 and is applied to the burners 3, 4, 5, 6 of the second group B2 via the branch line 9. Also, solenoid valve M
1 is supplied to the burners 2 of the first group B1 via another branch line 10.
A solenoid valve M3 is provided in the middle of the branch pipe 9, and a solenoid valve M2 is provided in the middle of the other branch pipe 10.
is provided. The burner 2 is ignited or extinguished by opening and closing the solenoid valve M2. Furthermore, the burners 3, 4, 5, and 6 are simultaneously ignited or extinguished by the opening and closing operations of the solenoid valve M3.

Ignition means 11 for igniting the burner 2 is provided near the burner 2 . This ignition means 1
1 is, for example, an electric igniter that applies a high voltage between electrodes and releases ignition energy by spark discharge. When the burner 2 is ignited by the ignition means 11, the fan 14 in the heating chamber 13 rotates.
As will be described later, the solenoid valve M3 is opened and the burners 3, 4, 5, and 6 are instantaneously lit, and all of the burners 3, 4, 5, and 6 are ignited. Further, in the vicinity of the burner 2, a flame detection means 12 is provided in association with the ignition means 11 to detect the presence or absence of ignition. The presence or absence of ignition is detected by the flame detection means 12, and when it is detected that the burner 2 is ignited, the fan 14 rotates, and as will be described later, the solenoid valve M3 is opened and the burner 2 is ignited. 3, 4,
5 and 6 are lit. If the flame detection means 12 detects that the flame is not ignited, the fan 13 remains stopped and the solenoid valves M1 and M2 are closed, the supply of gas fuel is cut off, and an alarm is issued. Solenoid valve M3 also remains closed. In this way safety is maintained.

When the burners 2 to 6 are ignited, combustion exhaust gas from the burners is guided into the heating chamber 13 of the cooking device 1. The combustion exhaust gas in this heating chamber 13 is
The heated object 1 is circulated in the heating chamber 13 by the
5 is heated entirely and uniformly. Heating chamber 13
is equipped with temperature detection means 16 such as a thermostat for detecting the heating temperature within the heating chamber 13.

FIG. 2 is a block diagram showing the control mechanism of the cooking appliance 1 according to the present invention. Outputs from the flame detection means 12 and the temperature detection means 16 are given to a processing circuit 17 realized by a microcomputer or the like. Further, outputs from the ignition switch 18 and heating cooking time setting key 30 provided on the operation panel of the cooking device 1 are provided to the processing circuit 17.
Furthermore, the set temperature T set in advance by temperature setting means 19 such as an operating knob provided on the operation panel of cooking appliance 1 is stored in memory 20 provided in processing circuit 17 .

The opening and closing operations of the solenoid valves M1, M2, and M3 are controlled by the processing circuit 17.
The rotation stop of the heating chamber 13 is thereby controlled.
The heating temperature inside is controlled to be a predetermined temperature T. Further, when the ignition switch 18 is turned on, the ignition means 11 performs the ignition operation via the processing circuit 17. When the flame detection means 12 detects that the flame is not ignited, the buzzer 31 is activated via the processing circuit 17 to emit an alarm sound.

FIG. 3 is a flow chart showing the control operation of the present invention. Moving from step n1 to step n2, the heating time t is set using the cooking time setting key 30. Next, proceeding to step n3, the temperature detecting means 16 is set to operate at the set temperature T and stored in the memory 20 of the processing circuit 17.

Next, in step n4, it is determined whether the set temperature T is 100°C or less. When the temperature is below 100℃,
The process moves to step n5, and thus steps n6 to n18 are executed only during the first temperature increase, and steps n18 to n27 are repeatedly executed during subsequent temperature adjustment. When the set temperature T exceeds 100 DEG C., steps n6 to n18 are executed, and the operation from step n19 to return to step n8 is repeated.

At step n6, the ignition switch 18 is turned on. When the ignition switch 18 is turned on, the process moves to steps n7 and n8, and the processing circuit 17 opens the solenoid valves M1 and M2. Solenoid valve M
1. When M2 is in the open state, next step n9
Then, the ignition means 11 performs the ignition operation. Due to the ignition operation by the ignition means 11, the flame detection means 12 determines whether or not the burner 2 is ignited in step n10, and if it is not ignited, the solenoid valves M1 and M2 are closed in step n28. In step n29, the buzzer 31 notifies the non-ignition state with an alarm sound. Burner 2
When the fan 14 in the heating chamber 13 is ignited, the fan 14 in the heating chamber 13 rotates in step n11. Next step n12,
In step n13, the solenoid valve M3 is opened and the burners 3, 4, 5, 6 are ignited simultaneously.
When the burner 2 is ignited, the burner 2 has already been ignited, in other words, the first group B1 and the second group
All the burners of group B2 are in the ignited state. Therefore, the heating temperature in the heating chamber 13 is increased in a short time. In this way, heating chamber 1
As the temperature inside the heating chamber increases, in step n14, the detection means 16 determines whether or not the heating chamber temperature has reached a predetermined first value, for example T+2°C, which is 2°C higher than the set temperature T. detected. When the set temperature T+2° C. is reached, the solenoid valves M2 and M3 are closed in step n15, and the fan 14 is stopped in step n16. This cuts off the fuel gas supplied to the burners 2-6, so that the burners 2-6 are simultaneously extinguished. After the burners 2 to 6 are extinguished in this way, the temperature inside the heating chamber 13 continues to fall. While the temperature of the heating chamber 13 is decreasing, in step n17, the temperature detection means 16 again detects that the temperature of the heating chamber 13 is a second value larger than the set temperature T and a predetermined first value of 2°C, for example. T-4, which is a temperature lower by 4℃
It is detected whether the temperature has reached ℃, and the set temperature is T-4℃.
When it is detected that the
Move to. In step n18, it is detected whether or not the time t set by the timer 30 has elapsed.
If the time t has elapsed, the solenoid valve M is activated in step n32.
1 is closed, and heating cooking is completed in step n33.

At step n18, if time t has not elapsed, the process moves to step n19. In step n19, it is checked whether there is a command to perform combustion control. If there is no command, the process returns to step n18. Thereafter, a series of operations from step n8 to step n19 is repeated.

In this way, the series of operations from step n8 to step n19 is repeated to perform temperature control in a high temperature range exceeding 100°C.

If there is a command to perform combustion control in step n19, the process moves to step n20, where the electromagnetic valve M2 is opened, and then the process moves to step n21, where the ignition means 11 performs an ignition operation. As a result of the ignition operation by the ignition means 11, it is determined in step n22 whether or not the burner 2 has been ignited. Burner 2
If it is not ignited, the solenoid valves M1 and M2 are closed in step n30, the gas supply is cut off, and the buzzer 31 emits an alarm sound in step n31 to notify the non-ignition state. When burner 2 is ignited, the step
Moving to n23, the fan 14 in the heating chamber 13 rotates,
The temperature inside the heating chamber 13 increases, and the temperature in the heating chamber 13 increases.
At n24, the temperature detection means 1 determines whether the temperature inside the heating chamber 13 has reached the predetermined set temperature T+2°C.
6. Predetermined temperature T+2℃
When it reaches step n25, the solenoid valve M2
is closed, and the process moves to step n26, where fan 1
4 stops. After the solenoid valve M2 enters the closed state, the temperature inside the heating chamber 13 decreases. While the heating temperature is decreasing, it is determined in step n27 whether or not it has reached the set temperature T-4°C again, and if it has reached the set temperature T-4°C, the process returns to step n18.
It is determined whether the set temperature T has passed or not. In this way, step from step n18
The series of operations up to n27 is repeated, and temperature control is performed so that the temperature in the heating chamber 13 reaches the set temperature.

In this way, when the set temperature T is in the high temperature range, the burners 2 to 6 are controlled on and off. When the set temperature T is in the low temperature range, burners 2 to 6 are ignited only during the first temperature rise, and only burner 2 is ignited during subsequent temperature adjustments.
On-off controlled. In this way, the heating temperature in the heating chamber 13 is maintained approximately at the set temperature T.

Note that when the cooking stop key 32 is operated during heating cooking, an interrupt signal is sent to the processing circuit 17.
As a result, all of the electromagnetic valves M1 to M3 are closed, the fan 14 is stopped, and cooking is stopped.

FIG. 4 is a graph showing the temperature distribution inside the heating chamber 13, FIG. 4 1 shows the case where the method according to the present invention is used, and FIG. 4 2 shows the case where the conventional method is used. There is. In this graph, the predetermined set temperature T is 100° C., and the temperature was measured at 32 points inside the heating chamber 13. In the case of the method according to the present invention, the temperature distribution in the heating chamber 13 is as shown in FIG.
The temperature ranges from 90°C to a maximum of 105°C, and the temperature distribution width is approximately 15°C. On the other hand, when the conventional method is used, as shown in FIG. 4, the minimum temperature ranges from 90°C to the maximum temperature of 130°C, and the temperature distribution width shows approximately 40°C. That is, when the present invention is used, the temperature distribution can be reduced to 1/2 or less, and good temperature control becomes possible.

In this way, in the present invention, the fan 14 is provided in the heating chamber 13, and is rotated when the burner 2 is burning, thereby making the temperature of the heating chamber 13 uniform, and also Sometimes, all burners 2 to 6 are operated, and during temperature adjustment, when the set temperature T is in the high temperature range, all burners 2 to 6 are operated.
On-off control is performed, and when the set temperature T is in the low temperature range, only burner 2 is controlled on-off so that it burns at 1/5 of the full load, so the temperature control width is wider than the conventional one. It is possible to reduce the amount of heat as much as possible and evenly heat cooked foods such as meat and fish that are difficult to transmit heat to the center. In addition, the energy consumption during temperature adjustment can be significantly reduced, and the temperature control characteristics in the low temperature range are good, so it can also be used for heat retention.

Furthermore, a second temperature is set lower than the set temperature T.
The value of 4℃ is the first temperature set higher than the set temperature T.
Since I chose a value larger than the value of 2℃,
For example, in a cooking device such as a gas microwave oven, the heating chamber 13 is separated from the atmosphere, and the rate of temperature drop in the heating chamber 13 is slower than the rate of temperature rise. It takes a relatively long time for the temperature to drop by 4° C. from the set temperature T, and the gas burner is not ignited during this period. Further, since the gas combustion time required to raise the temperature to a temperature 2° C. higher than the set temperature T is relatively short, it is sufficient to ignite the gas burner for only such a short period of time. In this way, the combustion time can be shortened as much as possible while keeping the temperature fluctuation width as small as possible, and the amount of gas fuel consumed can be saved.

Further, although a thermostat was used as the temperature detecting means 16 in the above embodiment, it is also possible to selectively heat the burners grouped into a plurality of groups according to the output using a temperature detecting element such as a thermistor. You can also do this.

Effects As described above, according to the present invention, the fan 14 is provided in the heating chamber 13, and when the burner is burning, the fan 14 is rotated.
The gas burners for making the internal temperature uniform and obtaining the combustion gas introduced into the heating chamber 13 are the gas burners 2 of the first group B1 and the gas burners 3 to 6 of the second group B2, which generate a larger amount of heat. ,
If the temperature T set by the temperature setting means 19 is below a predetermined reference value, the first to third solenoid valves M1 to M3 are opened and all After the gas burners 2 to 6 are ignited to raise the temperature, and the temperature in the heating chamber 13 reaches a temperature higher than the set temperature T by a predetermined value, the second solenoid valve M2 is opened and closed for temperature adjustment. Therefore, if the temperature is lower than the set temperature T by a predetermined value, the gas burner 2 of the group B1
In this way, the heating chamber 13 can be heated around the set temperature T with a small temperature fluctuation range. Further, when the temperature T set by the temperature setting means exceeds the reference value, the first to third solenoid valves M1 to M3 are controlled to open and close, and all gas burners in the first and second groups B1 and B2 are controlled to open and close. 2～
6 is on-off controlled to maintain the temperature inside the heating chamber 13 between a temperature higher than the set temperature T by a predetermined value and a temperature lower than the set temperature T by a predetermined value. so that the temperature is T,
In this way, it is possible to reduce the range of temperature fluctuation and heat the heating chamber 13, and to uniformly heat the food to be cooked, such as meat or fish, to the center, where heat does not easily conduct.

Furthermore, according to the present invention, the ignition means 11 ignites the gas burners 2 of the first group B1, and by igniting the gas burners 2 of the first group B1,
When the third solenoid valve M3 is open, the second group B
When igniting, the first and second solenoid valves M1 and M2 are opened, and the third solenoid valve M is opened.
3 remains closed and the ignition means 11 is operated,
When the flame detection means 12 does not detect the ignition of the gas burners 2 of the first group B1, the first and second electromagnetic valves M1 and M
2 is closed and the third solenoid valve is kept closed to cut off the supply of fuel gas to all the gas burners 2 to 6 of the first and second groups B1 and B2, so safety is ensured.

In particular, according to the present invention, the second value, which is set lower than the set temperature T, is selected to be larger than the predetermined first value, which is set higher than the set temperature T. In a cooking device such as a microwave oven, the inside of the heating chamber 13 is separated from the atmosphere;
In this case, the temperature decrease rate is slower than the temperature increase rate, and therefore it takes a relatively long time for the temperature to decrease by the second value from the set temperature T, and the gas burner is not ignited during this period. Further, since the means for raising the temperature from the set temperature T to the first value is relatively short, it is sufficient to ignite the gas burner for such a short period of time. In this way, the combustion time can be shortened as much as possible while keeping the temperature fluctuation width as small as possible, and the amount of gas fuel consumed can be saved.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of an embodiment of the gas cooker 1 according to the present invention, FIG. 2 is a block diagram showing the control mechanism of the gas cooker 1 according to the present invention, and FIG. 3 is a flowchart showing the control operation of the present invention. Chart, Figure 4 shows heating chamber 1
3 is a graph showing the temperature distribution within No. 3. DESCRIPTION OF SYMBOLS 1... Gas cooker, 2, 3, 4, 5, 6... Burner, 13... Heating chamber, 16... Temperature detection means, 17...
Processing circuit, M1, M2, M3...Solenoid valve, B1, B
2...Group.

Claims (1)

[Scope of Claims] 1 A plurality of gas burners 2 to 6 are divided into a first group B1 that generates a small amount of heat and a second group B2 that generates a large amount of heat that is ignited by transfer from the gas burners 2 of the first group B1. In a gas combustion control device for a cooker in which the gas burners 2 to 6 are grouped and heat the object 15 in the heating chamber 13, fuel is supplied to the gas burners 2 to 6 in the first and second groups B1 and B2. A first solenoid valve M1 that supplies/cuts off gas; a second solenoid valve M2 that supplies/cuts off fuel gas to the gas burners 2 of the first group B1; and a second solenoid valve M2 that supplies/cuts off fuel gas to the gas burners 3 to 6 of the second group B2. A third electromagnetic valve M3 that shuts off; an ignition means 11 that ignites the gas burners 2 of the first group B1; a flame detection means 12 that detects whether or not the gas burners 2 of the first group B1 are ignited; and the first and second groups. Heating chamber 13 into which combustion exhaust gas from gas burners 2 to 6 of B1 and B2 is guided
A fan 14 for keeping the temperature constant inside the heating chamber 13, and a temperature detection means 16 for detecting the temperature of the heating chamber 13.
and a temperature setting means 19 for setting a set temperature T at which the inside of the heating chamber 13 is to be heated; If so, first the first and second solenoid valves M1, M2
and close the third solenoid valve M3 to start the ignition means 1.
(a) When ignition is detected by the flame detection means 12, the fan 14 is rotated, (a1) the third solenoid valve M3 is opened, and the temperature is lowered from the set temperature T by the temperature detection means 16. When a temperature higher than a predetermined first value is detected for the first time after ignition, the second and third solenoid valves M2 and M3 are closed, and the fan 14 is stopped.
(a2) Thereafter, when the temperature detecting means 16 detects a temperature lower than the set temperature T by a predetermined second value, the second solenoid valve M2 is opened and the fan 14
(a3) when the temperature detecting means 16 detects a temperature higher than the set temperature T by a predetermined first value; , a second operation is performed in which the second solenoid valve M2 is closed, the fan 14 is stopped, and the third solenoid valve M3 is kept closed, and the first and second operations (a2),
(a3) is repeated, and (b) when ignition is not detected by the flame detection means 12, the first and second solenoid valves M
1, a first control means that closes M2 and issues an alarm, and a second control means that, when the temperature T set by the temperature setting means 19 exceeds a predetermined reference value, The ignition means 11 is started by opening the solenoid valves M1 and M2 and closing the third solenoid valve M3.
(c) When ignition is detected by the flame detection means 12, the fan 14 is rotated; (c1) the third solenoid valve M3 is opened; When a temperature higher than the first value determined is first detected after ignition, the second and third values are detected.
Close the solenoid valves M2 and M3 and stop the fan 14, (c2)
Thereafter, when the temperature detecting means 16 detects a temperature lower than the set temperature T by a predetermined second value, a third operation of opening the second and third solenoid valves M2 and M3 and rotating the fan 14 is performed. (c3) When the temperature detecting means 16 detects a temperature higher than the set temperature T by a predetermined first value, the second and third solenoid valves M2 and M3 are closed and the fan 14
performs a fourth operation to stop the ignition, and repeats the third and fourth operations (c2) and (c3), and (d) when ignition is not detected by the flame detection means 12, the first and second solenoid valves M1, 2. A gas combustion control device for a cooker, comprising: second control means for closing M2 and emitting an alarm, wherein the second value is selected to be larger than the first value.