JPH0440577Y2 - - Google Patents

Description

[Detailed explanation of the invention] (Field of application) This invention is a type of rice cooking in which the rice cooking power can be changed sequentially during the rice cooking process so that good rice can be cooked even if rice is started immediately after washing. The present invention relates to a preheating control device for a rice cooker, especially a rice cooker.

(Prior art and its problems) There are two types of conventional rice cookers of this kind.

One of them is, as shown in Figure 4, preheating A to increase the moisture content is performed at a constant heat for a certain time regardless of the amount of rice being cooked, and after this preheating is completed, the heat is adjusted in two stages in rice cooking heating B. Then, in the second half of this rice cooking heating, the fire power is set to low, the main detection device detects the end of rice cooking, and this output is used to advance the subsequent uneven heating. It is set to a weak firepower.

The other method, as shown in Figure 5, is to change the heat power conditions of preheating A according to the amount of rice to be cooked, set the heat power at this time when cooking a small amount of rice to be lower than that at the end of cooking, and The heating power in heating B is adjusted in two stages only in the case of cooking a small amount of rice, so that the heating power is suppressed in the latter half of heating the rice, and then a predetermined uneven time is allowed.

All of these devices are related to electric rice cookers, but in order to detect the temperature of the rice cooker, a heat-sensitive part is placed in contact with the bottom of the rice cooker, and the temperature is controlled at each time using this heat-sensitive part. A method is adopted in which this is done using the output of a thermostat installed in the unit.

The above conventional method does not control the temperature during preheating to increase the moisture content of rice grains, but in order to shorten this preheating time and stabilize the moisture content, the preheating temperature must be adjusted as quickly as possible. It is necessary to ensure and maintain this preheating temperature at a constant temperature. To this end, it is possible to adopt a configuration in which the preheating starting heating power is increased to quickly raise the temperature to the preheating set temperature, and the above-described heat sensitive section is provided with a detection means for detecting the preheating temperature.

However, with only the above configuration, even if the set thermal power is increased, the time required to reach the preheating temperature cannot be shortened as much as expected.

This is because when the preheating heat setting is increased, this heat directly affects the heat sensitive part, even though the temperature of the rice cooker has not reached the set temperature.
This is because the heat-sensitive section would reach the set temperature, which would cause the thermostat to operate. In other words, the temperature of the heat-sensitive part increases before that of the rice cooker.

(Technical Problem) The present invention is a rice cooker that heats a rice cooker C using a heating device 30 maintained at a predetermined heating power and controls the heating temperature of the rice cooker C according to the progress of the rice cooking operation. At the beginning of the rice cooking process, a preheating process for a predetermined period of time is provided to promote moisture absorption to the rice grains, and the preheating temperature is controlled by the output of the preheating temperature detection means 10 provided near the heating device 30. In order to effectively shorten this preheating time, the preheating temperature detection means for preheating temperature control is used to control the rice cooker once it reaches the preheating temperature without being affected by the heating means. The objective is to control the firepower even when the firepower is increased.

(Means) The technical means of the present invention taken to solve the above problem is to input the output of the preheating temperature detection means 10 and the output of the timer 2 that starts at the same time as the start of preheating to the OR circuit 6, The heating device 30 is operated by the output of 6, and the timer is in the output state for a set time.

(Operation) The above technical means of the present invention operates as follows.

When the rice cooking process starts, preheating starts.
At this time, the rice cooking pot is heated by the heating device 30, which is set in advance to a heat suitable for rice cooking, and at the same time, the timer 2 is activated. This brings about a preheating state, and the zero ambient temperature of the heat sensitive section rises. However, since the timer 2 is maintained in the output state for a set time, the preheating temperature detection means 10
The heating device 30 is maintained in the operating state by the output via the OR circuit 6 regardless of the detected output.
Therefore, even if a state in which the ambient air temperature temporarily rises above the temperature of the rice cooker occurs at the beginning of preheating, the output of the preheating temperature detection means 10 will cause the heating device 3 to
0 is not inactive, and the heating device 30 continues to operate. And the setting time of timer 2 is
Since it is set to a predetermined value in relation to the heating power of the heating device 30, the rice cooker is heated to the preheating set temperature when the set time elapses.

Thereafter, the heating device 30 is controlled by the output of the OR circuit 6 into which the detection output of the preheating temperature detection means 10 is input.
is controlled, and the temperature inside the rice cooker is maintained at the preheating temperature by repeating activation and deactivation of the heating device 30. It goes without saying that after this preheating step is completed, a rice cooking and heating step similar to that of a conventional rice cooker proceeds.

(Effects) Since the present invention has the above configuration, it has the following unique effects.

During preheating, the preheating temperature detecting means 10 does not work prematurely and is maintained at the preheating temperature for a predetermined period of time, so that the preheating time can be shortened. In other words, malfunction of the preheating temperature detection means 10 when the preheating thermal power is set to a large value can be prevented, and preheating can be completed in the shortest preheating time commensurate with the preheating thermal power.

In addition, during the preheating process, the temperature inside the rice cooker is maintained at a preheating temperature suitable for preheating for a predetermined period of time.
Accurate preheating is possible.

(Example) Hereinafter, an example of the present invention will be described based on FIGS. 2 and 3.

The first embodiment shown in FIG. 2 is implemented in a gas rice cooker.
A sensor serving as a preheating temperature detection means 10 is housed in the interior of the preheating temperature detecting means 10 . As the heating device 30, a combination of a main burner 1 and a solenoid valve 3 is adopted, and its excitation coil 31 and the output contact 12 of the sensor are connected in series.

This series circuit, the timer 2 and the ignition device 5 are connected in parallel, and when the operation switch 4 is closed, the timer and the ignition device are brought into conduction.

On the other hand, the normally open output contact 21 of the timer is connected in parallel with the output contact 12 to form an OR circuit 6, and this normally open output contact is closed at the same time as the timer 2 is started, and is opened when time-up occurs.

Therefore, when the operation switch 4 is closed, the normally open output contact 21 is closed for the time set by the timer, and the main burner 1 continues to burn for a certain period of time regardless of the output contact 12, and the rice cooker C is turned on. Increase to preheat temperature. When the set time of timer 2 has elapsed, output contact 12 turns ON according to the sensor output.
OFF, and the main burner 1 is repeatedly ignited and extinguished to maintain the preheating temperature.

Next, in the embodiment shown in FIG.
1 is provided with a water temperature detection sensor 13 in addition to the sensor as the preheating temperature detection means, and further incorporates two timers 2a and 2b with different set times, and the output contacts 22 and 23 of these timers 2a and 2b are The output contacts 12 of the sensor for detecting the preheating temperature are connected in parallel.

A changeover switch 14 is inserted in the circuit to the timers 2a and 2b, and is adapted to be switched in accordance with the output of the water temperature detection sensor 13. In addition, the water temperature detection sensor 13 detects the initial water temperature of the rice cooker C and switches the changeover switch 14. If the initial water temperature of the rice cooker C is below a certain level, the circuit of the timer 2a with the longer set time is turned on. In the opposite case, the timer 2b with the shorter set time is turned on.
becomes.

According to this embodiment, even if there is variation in the initial water temperature, the heating device 30 maintains the operating state without being affected by the initial heating time for preheating commensurate with the water temperature, that is, the output from the preheating temperature detection means 10. The duration of time will be set appropriately. The accuracy can be further improved by increasing the number of switching contacts and timers of the switching switch 14.

In addition, in any of the above-mentioned embodiments, although the control of the preheating step A has been described in detail, the control of the subsequent steps of rice cooking and heating B is the same as the conventional method. Since this point is well known, the explanation thereof will be omitted.

Further, in each of the above cases, the case where the present invention is applied to a gas rice cooker is illustrated, but when the invention is applied to an electric rice cooker, the heating device is an electric heater.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of the present invention, Figure 2 is an explanatory diagram of the first embodiment, Figure 3 is an explanatory diagram of the second embodiment, and Figure 4 is an explanatory diagram of the second embodiment.
FIG. 5 is an explanatory diagram of a conventional example, and in the figure, 10... preheating temperature detection means, 11... heat sensitive section,
12... Output contact, 2, 2a, 2b... Timer, 21, 22, 23... Output contact, 31... Excitation coil.

Claims (1)

[Scope of utility model registration request] The rice cooker controls the heating temperature of the rice cooking pot C by the heating device 30 for heating the rice as the rice cooking operation progresses, and the rice cooker controls the heating temperature of the rice cooking pot C by the rice cooking heating device 30 as the rice cooking operation progresses. In a preheating control device for a rice cooker that includes a preheating process by the heating device 30 and controls the preheating temperature by the output of a preheating temperature detecting means 10 provided near the heating device 30, the preheating temperature detecting means 10 and the output of a timer 2 that starts at the same time as the start of preheating are input to an OR circuit 6, and the heating device 30 is operated by the output of this OR circuit 6.
A preheating control device for a rice cooker, wherein the timer is in an output state for a set time.