JP3524666B2 - Gas cooker - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rice cooker, and more particularly to a rice cooker having a function of retaining heat by gas combustion after completion of rice cooking.

[0002]

2. Description of the Related Art Conventionally, a gas rice cooker is known to be able to cook delicious rice in a shorter time than an electric rice cooker due to the strong heat of a gas burner. There are two methods of keeping heat after cooking rice in such a gas rice cooker: one that uses a commercial power source to keep warm with an electric heater, and one that keeps warm with a gas pilot burner. This is convenient because it does not require the work of securing a commercial power source.

[0003]

However, in the rice cooker of the type in which the gas is used as a pilot fire burner, the heating of the bottom of the pot is local and the heating is caused by the direct fire of the burner, which results in a temperature distribution. It was bad, and the corresponding part was sometimes colored or scorched. Therefore, it is conceivable to provide a burner burner flame port in a wide range, but this not only complicates the structure but also requires an extra installation space for the burner, resulting in an increase in size of the appliance itself. It is also possible to use the rice cooking burner as the heat retaining burner, but it becomes difficult to reduce the combustion amount to the required heat amount this time. Therefore, there is a problem that the temperature cannot be kept for a long time unlike the type using an electric heater.

The gas rice cooker of the present invention solves the above problems,
The purpose is to keep good heat with a simple structure without using an electric heater.

[0005]

[0006]

[0007]

[0008]

Gas cooker according to the first aspect of the present invention to solve the above problems SUMMARY OF THE INVENTION comprises a burner which is arranged a number of burner ports in the circumferential direction on the side surface top of the annular mixture chamber, A gas rice cooker that heats a rice cooker placed above the burner to cook rice, and shifts to a heat retention mode after completion of rice cooking to reduce the heating power of the burner to keep the rice cooker warm. A ring-shaped hot plate is provided coaxially with the burner's annular mixture chamber between the rice cooker and the combustion flame during heat retention of the burner is covered by the ring-shaped hot plate so that the rice cooker is not directly heated. At the same time, the gist of the hot plate is that it moves to a position where it covers the flame during heat retention as the rice is cooked.

A gas cooker according to a second aspect of the present invention which solves the above-mentioned problems is provided with a burner in which a large number of flame openings are circumferentially arranged in an upper side surface of an annular mixture chamber, and the burner is mounted above the burner. A gas rice cooker that heats the placed rice cooker to cook the rice, and shifts to the heat retention mode after the rice is cooked to lower the heating power of the burner to keep the rice cooker warm, and between the burner and the rice cooker. In addition, a ring-shaped hot plate is provided coaxially with the annular mixture chamber of the burner so that the combustion flame when the burner is kept warm is covered by the ring-shaped hot plate and the rice cooker is not directly heated. The gist of the present invention is to provide a heat-sensitive responding body that comes into contact with the bottom surface of the heat-dissipating body and is displaced when a predetermined temperature of the bottom of the pot is reached, and to mount the hot plate on the heat-sensitive responding body.

[0010]

[0011]

[0012]

[0013] Gas cooker according to the first aspect of the present invention having the above structure, the heat plate is moved with the cooking completion, be set to the optimum position for each of the flame and the time kept at the time of cooking You can Therefore, even if the shape and size of the rice cooking flame changes due to the control of the amount of rice cooked and burned, it is not necessary to set a fixed position according to the flame of rice cooking and heat retention, and the position of the hot plate can be set easily. Can be determined.

In the gas cooker according to the second aspect of the present invention having the above-mentioned structure, since the hot plate is attached to the thermosensitive body, when the pot bottom temperature reaches a predetermined temperature and the thermosensitive body is displaced downward, The hot plate also moves downward and approaches the burner flame top. As described above, since the heat-responsive body is interlocked with the heat-responsive body, the switching of the hot plate between the heat retention and the rice cooking is surely performed.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION In order to further clarify the constitution and operation of the present invention described above, preferred reference examples and examples of the gas rice cooker of the present invention will be described below. FIG. 1 is a schematic configuration diagram of a gas rice cooker as a reference example of the present invention. The gas rice cooker is roughly divided into a rice cooker 10 and a controller 40.

The rice cooking section 10 is a pot 11 for storing rice and water.
A burner 12 that burns and heats the pot 11; a gas supply path 13 that supplies gas to the burner 12; and a solenoid valve 14 that is provided in parallel in the middle of the gas supply path 13 and that supplies and shuts off different amounts of gas. , 15, 16 and solenoid valves 14, 1
An original solenoid valve 17 for shutting off gas supply to 5 and 16, and an igniter 18 for generating a high voltage for ignition to the burner 12.
An electrode 19 that is sparked by the voltage generated from the igniter 18, a thermoelectric generator 20 that is composed of a plurality of thermocouples that are connected in series and that detects the presence or absence of a flame and generates an electromotive force by the combustion heat of the burner 12; And a temperature sensor 23 for detecting the temperature of the bottom 2. Further, the burner 12 has an annular mixture chamber 12a formed at the head thereof, and a large number of flame ports 21 are arranged in the circumferential direction on the outer peripheral side surface of the upper portion thereof.

A ring-shaped heat plate 31 made of metal having good thermal conductivity and heat resistance is attached to the temperature sensor 23. The ring-shaped hot plate 31 is formed to have a size larger than the outer peripheral diameter in which the burner flame port is arranged.
It is provided at a height position where only the flame when heating is heated without contacting the flame when cooking rice. The heating plate 31 is attached to the outer case of the temperature sensor 23, and there is no influence of heating on the internal temperature sensing part.

The solenoid valves 14, 15 and 16 respectively supply different amounts of gas, and the heating power is adjusted by properly using these three solenoid valves. High heat (130 in this example)
0kcal / h) requires solenoid valves 14 and 15 to open, medium heat (1000kcal / h in this reference example ) requires solenoid valve 14 only, low heat (800kcal / h in this reference example ) In this case, only the solenoid valve 15 is opened, and only the solenoid valve 16 is opened for heating while keeping heat (500 kcal / h in this reference example ).

The controller 40 is provided with a rice cooking / heat keeping control circuit (not shown) for controlling rice cooking and heat keeping based on the temperature detection from the temperature sensor 23, and a load drive circuit 40a as shown in FIG. The load driving circuit 40a attracts the magnet source solenoid valve 17 while energized, the booster circuit 41 that boosts the thermoelectromotive force of the thermoelectric generator 20, the current adjusting resistor 44, the igniter 18 that generates a high voltage, and the energizer. A coil 26 for maintaining, a diode D1 for regulating the energizing direction,
D2, switches S1 and S2 that are turned on and off in conjunction with ignition and extinguishing operations, and a switch S3 that is turned on only during ignition operations. Then, the solenoid valves 14 to 17 are opened and closed based on the value detected by the sensor 23.

Next, the operation of the gas rice cooker of this reference example will be described. The magnet-source solenoid valve 17 is mechanically pushed open by an ignition operation (not shown), and at the same time, the switch S1,
S2 and S3 are turned on, and the current adjustment resistor 44 from the storage battery 22
Via the booster circuit 41, the igniter 18 and the coil 4
Power is supplied to 6. Solenoid valve 1 by its power supply
4 and 15 are opened and gas is supplied to the burner 12,
The igniter 18 is activated to spark the electrode 19 and ignite the burner 12. Further, by energizing the coil 46, the magnet-source solenoid valve 17 is attracted, and the rice cooking combustion is continued by high heat. Further, the combustion heat of the burner 12 generates a thermoelectromotive force of the thermoelectric generator 20, which is boosted by the booster circuit 41 supplied with the power. Then, the surplus power is stored in the storage battery 22 and is supplied from the storage battery 22 at the time of next ignition.

As shown in FIG. 2a, since the hot plate 31 is set above the flame outlet 21 where the flame during rice cooking does not come into contact, the flame is cooled by the hot plate and adversely affects the heating of rice cooking. There is no such thing. Further, since the flame during rice cooking is formed obliquely upward due to the resultant force of the jet speed in the horizontal direction and the upward draft force, it is easy to set the hot plate to a position where it does not come into contact with the flame. In addition, even if the bottom 2 of the pot is partially heated by a direct flame of flame or high-temperature exhaust gas when cooking rice, the heat transfer in the pot is convective heat transfer due to the flow of rice and water, so the bottom 2 of the pot is partially It does not easily get hot and has little adverse effect on the distribution of cooked rice.

Further, the controller 40 constantly detects the temperature of the pot 11 by the temperature sensor 23 during cooking, and the temperature sensor 23
Detects the first set temperature (145 ° C. in this reference example ), it is determined that the rice cooking is completed, and the solenoid valves 14 and 15 and the original solenoid valve 1 are determined.
7 is closed, the burner 12 is extinguished, and warming operation starts. At this time, as shown in the transition a of FIG.
When the sensor 23 detects that the temperature has dropped gradually to the third set temperature (65 ° C. in the present reference example ) by extinguishing the fire, the controller 40 opens the solenoid valve 16 and the original solenoid valve 17, Activate the igniter 18 to ignite the burner 12,
Performs heating operation by heat retention combustion. Burner 1 for heat retention combustion
It is heating with the minimum combustion amount of 2 (500 kcal / h), but the temperature rises again because the combustion amount is too large to keep it warm. When it is detected that the temperature of the bottom 2 has risen to the second set temperature (77 ° C. in this reference example ), the controller 40 closes the solenoid valve 16 and the original solenoid valve 17 to shut off the gas and extinguish the burner 12. This causes the temperature to drop. By repeating the ignition and extinguishing operations in this manner, it is possible to maintain the temperature within a predetermined temperature range.

When the heat is kept after the rice is cooked, the heat transfer in the pot is changed to conduction heat transfer because the moisture is absorbed by the rice and becomes rice.
When heat is transmitted slowly and local heating is performed, the temperature of the corresponding portion rises, and coloring and scorching are likely to occur.
Further, the heat retaining flame has no jetting force and is formed almost directly above the flame opening, and as shown in FIG. 2B, the heat plate 3 provided above the flame opening.
Heat 1. The heat plate 31 absorbs the heat of the flame and diffuses and releases the heat as radiant heat. Therefore, the local heating of the flame is eliminated and the rice cooker is heated uniformly, and the temperature distribution of the rice cooker bottom 2 is kept uniform as shown in the cooker bottom temperature distribution graph a in FIG. In addition, the heat retention flame has a considerably smaller amount of combustion than the rice cooking flame and has almost no horizontal ejection speed, so it is formed above by the draft force. Therefore, set the heat plate 31 to a position that covers the flame. Is easy. Further, since the amount of combustion of the flame during heat retention is small, there is almost no adverse effect of heating the hot plate 31.

Compared with the temperature change in the conventional heat retention by the burner burner, in the case of the heat retention by the burner burner (transition b in FIG. 4), it is impossible to change the combustion amount during the heat retention depending on the amount of rice or the room temperature. The amount of combustion is set so that the temperature does not rise due to heat retention under any conditions. Therefore, after cooking rice, the temperature falls below the predetermined temperature range with the lapse of time, whereas the temperature change according to this reference example (transition a in FIG. 4) keeps heat for a long time by keeping the temperature within the predetermined temperature range. I see that it is possible.

As explained above, according to the gas cooker of the reference example of the present invention, the heating plate 31 is provided between the burner flame port 21 and the bottom 2 of the burner to avoid the heating of the pot by the direct flame during the heat retaining combustion. Radiant heat of the heating plate uniformly heats the bottom 2 of the pot, so that it does not partially burn. Further, since the heat of the heat retaining flame is widely diffused by the heat plate 31, the combustion amount of the burner 12 at the time of heat retaining can be set relatively high. Therefore, the burner 12 can be narrowed down to the required combustion amount and can also be used as a heat retaining burner. Further, since the burner 12 can also be used as a heat retaining burner, it is not necessary to separately provide a heat retaining burner, and the number of parts is reduced. Further, since the burner 12 is repeatedly ignited and extinguished to maintain a predetermined temperature range, it is possible to maintain an optimum heat retention state. Also, the amount of combustion can be adjusted to large, medium, or small by switching the solenoid valve, so delicious rice can be cooked. Further, since it is started by the storage battery 22, it is not necessary to use a commercial power source, which is convenient. Also,
Since the heat of the thermal insulation flame is widely diffused by the hot plate 31, ON, O
The FF cycle becomes longer and the setting range of the pot bottom temperature can be narrowed. Also, since the number of ignitions is reduced, the power consumption of the storage battery is reduced and the life is extended. Further, since the heat plate 31 is made of a metal having good thermal conductivity, the surface temperature distribution becomes uniform, and the heat plate 31 radiates uniformly.

Next, a gas rice cooker as an embodiment will be described with reference to FIG. Gas rice cookers are roughly divided into 10 rice cookers.
And a controller 40.

The rice cooking section 10 is a pot 11 for storing rice and water.
A burner 12 that burns and heats the pot 11; a gas supply path 13 that supplies gas to the burner 12; and a solenoid valve 14 that is provided in parallel in the middle of the gas supply path 13 and that supplies and shuts off different amounts of gas. , 16, a source solenoid valve 17 for shutting off gas supply to the solenoid valves 14, 16, an igniter 18 for generating a high voltage for ignition to the burner 12, and an electrode 19 for sparking by a voltage generated by the igniter 18.
And a thermocouple 20 for detecting the presence or absence of flame, and the bottom 2 of the pot 11.
And a temperature sensor 30 that detects the temperature. Further, the burner 12 has an annular mixture chamber 12a formed at the head thereof, and a large number of flame ports 21 are arranged in the circumferential direction on the outer peripheral side surface of the upper portion thereof.

Further, as shown in FIG. 6, the temperature sensor 30 is brought into contact with the bottom 2 to detect the temperature of the bottom 2. The non-magnetic cover 37 is provided so that one end of the cover 37 is brought into contact with the surface of the pot bottom 2 by the pressing spring 35 fixed to the fixing portion 25, and inside the temperature-sensitive ferrite 3 whose magnetism changes according to temperature.
8 and a magnet 39 that faces the temperature-sensitive ferrite 38 to attract and desorb. Also, one end is fixed to the magnet 39, and the heat-sensitive responsive shaft 3 moves up and down integrally with the magnet 39.
3 is provided. A return spring 34 for urging the magnet 39 in a detaching direction from the temperature-sensitive ferrite 38 is provided at an intermediate position on the thermosensitive shaft 33. Further, as shown in FIG. 7A, a ring-shaped heat plate 31 made of metal having good heat conductivity and heat resistance is attached in the middle of the heat-responsive shaft 33 via a support piece, and is close to the pot bottom 2. Set to the position.

Further, the solenoid valves 14 and 16 supply different amounts of gas, and the two solenoid valves regulate the heating power of the rice cooking combustion and the heat retaining combustion. When cooking rice is burning (1 in this embodiment)
(300 kcal / h) opens the solenoid valves 14 and 16, and at the time of heat retention combustion (200 kcal / h in this embodiment), the solenoid valve 14 is closed and only the solenoid valve 16 is opened.

[0030] Next, the operation of the temperature-sensitive sensor embodiment will be described. At the start of cooking rice, when the burner 12 is ignited, the pot bottom 2
Since the temperature is lower than the predetermined temperature, the attraction force between the temperature-sensitive ferrite 38 of the temperature-sensitive sensor 30 and the magnet 39 is larger than the force of the return spring 34 whose one end is fixed to the fixing portion 25. Therefore, as shown in FIG. The temperature sensor 30 maintains the initial state.
Then, as the temperature of the bottom 2 gradually rises, the temperature of the temperature sensor 30 also rises accordingly. then,
When the temperature of the temperature-sensitive ferrite 38 reaches a predetermined temperature (the temperature near the Curie point in this embodiment) after the rice is cooked, the magnetism of the temperature-sensitive ferrite 38 changes from ferromagnetism to paramagnetism, and the attractive force with the magnet 39. Rapidly weakens. And FIG. 7 (B)
As shown in FIG. 5, the force of the return spring 34 overcomes the attraction force to separate the magnet 39 from the temperature-sensitive ferrite 38. At the same time, the heat-responsive shaft 33 is moved downward by the force of the return spring 34, a fire extinguishing switch (not shown) is pressed, the electromagnetic valve 14 is closed, and the heat retaining combustion state is entered. Further, the heat plate 31 attached to the heat-sensitive reaction shaft 33 also moves downward, and the attaching portion 36 is pressed against the stopper 32 by the force of the return spring 34, so that the heat plate 31 is kept at the set position. Then, the ring-shaped hot plate absorbs the heat of the combustion flame at the time of heat retention, and diffuses the heat as radiant heat to release the heat. Therefore, the local heating due to the flame disappears and the rice cooker is heated uniformly,
It is possible to maintain the heat retention state of the optimum temperature distribution for a long time.

As described above, according to the gas rice cooker of the present embodiment, the heat plate 31 is interlocked with the heat-sensitive responsive shaft 33 which is displaced during the combustion of rice cooked and the heat retention thereof, and the heat plate 31 is burned by each combustion flame. Since it can be set to a position suitable for, i.e., a position that covers the warm flame and does not touch the rice cooking flame, it depends on the size of the flame depending on the type of fuel gas and the amount of combustion. Position can be easily determined without Further, since the heating plate 31 is provided, the reduction of the combustion amount at the time of heat retention becomes relatively high, and the burner 12 can also be used as a heat retention burner. Therefore, since it is not necessary to separately provide a heat insulating burner, space can be saved, the number of parts can be reduced, the structure can be simplified, and the cost can be reduced. Further, since the heat-sensitive responsive shaft 33 is provided which is displaced when the rice is cooked and the heat is kept warm, it can be linked with the ignition and fire extinguishing switches, which is convenient. Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments. For example, the heat-responsive material may be a linear expansion bimetal, a volume expansion paraffin, or a vapor pressure ether.
Of course, alcohol may be used, and various embodiments can be carried out without departing from the spirit of the present invention.

[0032]

[0033]

[0034]

[0035]

According to the gas rice cooker according to the first aspect of the present invention, since the hot plate can be set for each of the rice cooking flame and the heat retaining flame, the difference in the size of the flame when the supply gas pressure is high or low. As a result, at the optimum setting position of the hot plate during heat retention, the flame during rice cooking does not touch the hot plate,
The hot plate can be easily set at the optimum position where the heat can be uniformly distributed.

Further, according to the gas cooker according to the second aspect of the present invention, since the hot plate is interlocked with the heat-sensitive responsive shaft, the position of the hot plate can be reliably switched between heat retention and rice cooking. it can.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a gas rice cooker as a reference example of the present invention.

FIG. 2 is an explanatory diagram showing a positional relationship between a burner flame and a hot plate.

FIG. 3 is a graph showing a temperature distribution of rice on a bottom of a pot during heat retention.

FIG. 4 is a graph showing a temperature change of rice on a bottom of a pot during heat retention.

FIG. 5 is a schematic configuration diagram of a gas rice cooker as an embodiment of the present invention.

FIG. 6 is an enlarged view of the temperature sensor of FIG.

FIG. 7 is an explanatory diagram showing a positional relationship between a burner flame and a heating plate.

FIG. 8 is an explanatory diagram of a controller.

[Explanation of symbols]

2 ... pot bottom 10 ... rice cooker 11 ... pot 12 ... Burner 12a ... Annular mixture chamber 18 ... Igniter 20 ... Thermocouple 21 ... Burner flame mouth 22 ... Dry battery 23 ... Temperature sensor 30 ... Temperature sensor 31 ... Hot plate 32 ... Stopper 33 ... Thermosensitive axis 34 ... Return spring 36 ... Encircling section 40 ... Controller 40a ... Load drive circuit 41 ... Booster circuit

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-54-117277 (JP, A) Actually opened 61-86123 (JP, U) Actually opened 59-86501 (JP, U) (58) Field (Int.Cl. ⁷ , DB name) A47J 27/00 105 A47J 27/00 109

Claims (2)

(57) [Claims] 1. A burner having a large number of flame openings arranged in the circumferential direction is provided at an upper portion of a side surface of an annular mixture chamber, and a rice cooker placed above the burner is heated to cook rice. A gas rice cooker that shifts to a heat retention mode to reduce the heating power of the burner to keep the rice cooker warm, wherein a ring-shaped hot plate is coaxial between the burner and the rice cooker and coaxial with the annular mixture chamber of the burner. The heating flame of the burner is kept covered by the ring-shaped hot plate so as not to directly heat the rice cooker, and the hot plate moves to a position where the flame is kept warm when the rice is cooked. A gas rice cooker characterized by that. 2. A burner having a large number of flame openings arranged in the circumferential direction is provided at an upper portion of a side surface of the annular mixture chamber, and a rice cooker placed above the burner is heated to cook rice. A gas rice cooker that shifts to a heat retention mode to reduce the heating power of the burner to keep the rice cooker warm, wherein a ring-shaped hot plate is coaxial between the burner and the rice cooker and coaxial with the annular mixture chamber of the burner. The heating flame of the burner is kept covered by the ring-shaped hot plate so that it does not directly heat the rice cooker, and it comes into contact with the bottom of the rice cooker and displaces when the temperature reaches a predetermined bottom. A gas rice cooker comprising a heat sensitive body, and the hot plate attached to the heat sensitive body.