JPH01217129A - Microwave oven - Google Patents

Abstract

PURPOSE:To obtain the stabilized finish of cooking even when a foodstuff is cooked repeatedly, by controlling the heating of the foodstuff based on the detecting value of the concentration of gas, generated from the foodstuff during heating. CONSTITUTION:A change rate operating means 4 operates a change rate of the output VSE of a gas detecting device 2 with respect to a time immediately after starting cooking. When a foodstuff is cooked repeatedly, the change rate, operated by the change rate operating means 4, becomes larger when the amount of remaining gas in the case of an oven before cooking is more. Accordingly, a cooking constant setting means 5 decides that the cooking is repeated cooking more than two times when the operated change rate is higher than a predetermined value and sets cooking constants alpha, beta, smaller than the cooking constant of first time. The control of next heating is effected by a heating control means 7 based on the cooking constants alpha, betaand the output Vmax of a maximum value detecting means 6 as follows; heating is effected for a time (t1) after starting the heating and, further, additional heating is effected for a time beta.t1 when the time (t1) means a time from the starting of the heating to a time when the output VSE of the gas detecting device 2 becomes equal to a value Vmax-alpha.Vmax.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a microwave oven that automatically cooks food based on a detected value of the concentration of gas generated from one food during heating.

(Prior Art) A case in which food is automatically cooked using a conventional microwave oven will be described. In FIG. 3, after food 40 is placed on rotating plate 32 and door 31 is closed, a cooking setting key (not shown) provided on operation panel 34 is selected and pressed. Next, when a cooking start key (not shown) provided on the operation panel 34 is pressed, the cooling fan 35 rotates and outside air is sucked into the oven compartment of the microwave oven. Then, after about 16 seconds have elapsed, heating of the food 40 is started. After a while after the start of heating, gases such as steam, smoke, and odor are generated from the food 40. The concentration of this gas is determined by the gas detection device 2.
detected by.

Note that these gases are exhausted to the outside together with the outside air sucked into the oven chamber by the cooling fan 35 through a guide in which the gas detection sensor 2a of the gas detection device 2 is installed.

The cooking time for automatic cooking is controlled by the output of the gas detection device 2,
The microcomputer 25 shown in FIG.
It is carried out by In FIG. 2, gas detection device 2
has a resistor R8, a gas detection sensor 2a, and a noise removal circuit 2b. The gas detection sensor 2a decreases its resistance value as the concentration of the gas to be detected increases. The gas detection sensor 2a and the resistor R8 are connected in series. After noise is removed from the partial pressure ■sE of the gas detection sensor 2a by a noise removal circuit 2b consisting of resistors R1 and R2 and a capacitor CI, the microcomputer 25
sent to. The microcomputer 25 includes a CPU 25a and a power supply section 2.
5b1 key matrix 25c1 display section 25d1 control section 25e1 and memory 25f. When a cooking setting key is selected in the key matrix 25c, the cooking constants α and β stored in the memory 25f are determined by the CPU 25a based on the selection result and the detection output of the aforementioned weight detection device (not shown). be selected.

This selected cooking constant α.

Based on β and the output v8E of the gas detection device 2, the CPU 25
The heating control shown in FIG. 4 is performed by a.

In FIG. 4, t has passed since the cooking start key was turned on. (
For about 16 seconds), the microwave for heating the food 40 is not oscillated, and only the cooling fan 35 is driven, refreshing the inside of the refrigerator. Therefore, at this time, food 40
Since no gas is generated from the output v of the gas detection device 2
8. is almost constant and takes a value close to the maximum value V□xi. Refresh time t. Heating starts when the time period elapses. As the food 40 is heated, gas such as steam and smoke is generated from the food 40, and the output vSP of the gas detection device 2,
begins to decrease. Output v of gas detection device 2 from the start of heating
The CPU 25a counts the time t1 until sE becomes equal to V□81-α・V□xi, and further calculates the time β・V□xi.
Additional heat is applied for tl. Therefore, the total heating time is t1
+β・tl, and the total cooking time T is to +t1+
It becomes equal to β·tl.

(Problem to be solved by the invention) When automatic cooking is repeatedly performed using a conventional microwave oven, gas (also referred to as gas) generated during the previous cooking may remain inside the oven after the second cooking. I will do it.

After the previous cooking is completed, when the door 31 of the microwave oven is closed and only the cooling fan 35 is operated, the time required for the residual gas to be completely exhausted is τ as shown in FIG. It takes time. τ. According to experiments, the value is approximately 3 to 5 minutes.

Therefore, when automatic cooking is repeated, the output (2) of the gas detection device 2 changes as shown in the graph g2 shown in FIG. 6 in the second and subsequent cooking cycles.

E That is, since the cooling fan 35 is operating during cooking, the output vSE of the gas detection device 2 increases from the start of cooking until gas is generated, and reaches the maximum value vffiaX2 just before gas is generated from the food 40. (<va+axl). When gas is generated from the food 40, the output v8 of the gas detection device 2 begins to decrease. Further, the output vSE of the gas detection device 2 in the first cooking becomes the graph g1 shown in FIG. 6, as explained in FIG. 4.

On the other hand, the cooking time, that is, the cooking constants α and β that determine the heating time, are determined based on the cooking method indicated by the selected cooking setting key and the output of the weight detection device as described above. When cooking, if the cooking method and the amount of ffl of the food are the same for the first time and the second and subsequent times, the cooking constant α is the same.

β will be selected by the CPU 25a.

In addition, when cooking repeatedly, the maximum value V□8□ of the output V8E of the gas detection device 2 in the second and subsequent cooking is as follows:
As mentioned above, due to the influence of residual gas, the maximum value vmaxi of the output vsE of the gas detection device 2 in the first cooking
becomes smaller than

Therefore, in the second cooking, the output VsE of the gas detection device 2 from the start of heating is vIax2-α·vIll
The time t12 until it becomes equal to ax2 is the output vsE of the gas detection device 2 from the start of heating in the first cooking.
The time it takes for ``maxl-α・va+axl'' to become equal to ``maxl-α・va+axl is longer by △t1.Therefore, +1 The general heat time for the second and subsequent cooking is compared to the general heat time for the first cooking. The length increases by Δt1+β·Δt1.When cooking repeatedly in this way, the edge heating time becomes longer, resulting in overcooking from the second time onwards, making it difficult to obtain a stable cooking finish. .

The present invention has been made in consideration of the above-mentioned problems, and an object of the present invention is to provide a microwave oven that can provide stable cooking results even when cooking is repeated.

[Structure of the invention]

(Means for Solving the Problems) The present invention detects the concentration of gas generated from the food during heating in a microwave oven that cooks food by oscillating microwaves, and outputs an output as the concentration of this gas increases. a gas detection device that calculates the rate of change in the output of the gas detection device with respect to time immediately after the start of cooking; and a calculation device that calculates cooking constants α, β ( 1) and the maximum value V of the output of the gas detection device after heating the food.
and the output of the gas detection device from the heating start lax to V −α・V a+a
If the time until x max becomes equal is tl, the general thermal time is t
The present invention is characterized in that a heating control means for controlling heating so that +β·tl is provided.

(Function) According to the microwave oven according to the present invention configured as described above, the rate of change in the output of the gas detection device over time immediately after the start of cooking is calculated by the calculation means.

This calculated rate of change is affected by residual gas remaining in the microwave oven before cooking. That is, the greater the amount of residual gas, the greater the calculated rate of change. Also, the cooking constant α is based on the weight of the food, the cooking method, and the output of the calculation means.

β is set in the setting means. By using the set cooking constants α and β and controlling the general heating time of cooking by the heating control means, a stable cooking finish can be obtained even when cooking is repeated.

(Example) FIG. 1 shows an example of a microwave oven according to the present invention. The microwave oven of this embodiment includes a gas detection device 2, a rate of change calculation means 4, a cooking constant setting means 5, a maximum value detection means 6, and a heating control means 7. Since the gas detection device 2 has already been explained in the section of the prior art, its explanation will be omitted. The change rate operator stage 4 receives the output V8 of the gas detection device 2 immediately after the start of cooking.
- Calculate the rate of change over time.

The cooking constant setting means 5 sets cooking constants α and β based on the weight of the food, the cooking method, and the output of the rate of change calculation means 4. The maximum value detection means 6 detects the maximum value iii! of the output vSH of the gas detection device 2 after heating has started! Detect v, a8. The heating control means 7 controls the food so that the thermal time is t + β·tl, where tl is the time from the start of heating until the output vsE of the gas detection device becomes equal to V□8−α·■. Control heating.

Next, the operation of the embodiment will be explained by taking as an example the case of repeated cooking. The rate of change calculated by the rate of change calculation means 4 is affected by residual gas remaining in the oven before cooking. That is, if there is a large amount of residual gas, the calculated value of the rate of change will be large, and if there is little residual gas, the calculated value of the rate of change will be small. Therefore, when the calculated rate of change is greater than or equal to a predetermined value, the cooking constant setting means 5 determines that the cooking is repeated from the second time onwards.

Cooking constants α and β are set smaller than the cooking constants set when there is no residual gas, such as in the first cooking. For example, when there is no residual gas, that is, when the cooking constant α is 0.2 and the cooking constant β is 1.2, which are set based on the weight of the food and the cooking method, the rate of change calculation means 4
When the rate of change, which is the output of
5, β-1, 2.

Note that α and β when the rate of change is a predetermined value or more are set so that the general thermal time at this time is equal to the general thermal time when there is no residual gas. Therefore, in the above explanation, α
For example, amo, 2, β-1,
It can be set to 0, or both α and β can be set to be small.

Based on the cooking constants α and β thus set and the output V of the maximum value detection means 6, the heating control means 7 performs the following heating control.

That is, from the start of heating, the output ■sE of the gas detection device 2 is VIIa! −α・v, the time t takes to become equal to ax
1, heating is performed for t1 hours from the start of heating, and further β・
Apply additional heat for t1 hours. I wanted to generalize heat time 11+
β・tl.

As described above, according to this embodiment, a stable cooking finish can be obtained even when cooking is repeated.

Note that when the output of the chemotaxis calculation means 4 is equal to or higher than a predetermined value, the values of the cooking constants α and β are set to be small in this embodiment, but the cooking constants α and β are not changed and the cooking process is performed. Refresh time 1 from when the start key is turned on until heating starts
The same effect as in this embodiment can also be obtained by making 0 longer than (1o-240 seconds).

〔Effect of the invention〕

According to the microwave oven of the present invention, stable cooking results can be obtained even when cooking is repeated.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the microwave oven according to the present invention, Fig. 2 is a block diagram showing the control system of the microwave oven shown in Fig. 3, and Fig. 3 is an electronic oven having a gas detection sensor. A plan view of the oven, Figure 4 is a graph showing the change in the output of the gas detection device with respect to cooking time when there is no residual gas in the oven, and Figure 5 is a graph showing the change in the output of the gas detection device with respect to cooking time when there is no residual gas in the oven. A graph showing changes in the output of the gas detection device when it is operated, Figure 6 shows the first mouthful of repeated cooking: JRPI! It is a graph showing the change in the output of the gas detection device in the second cooking. 2... Gas detection device, 4... Change rate calculation means, 5.
... Cooking constant setting means, 6... Maximum value detection means, 7.
...Heating control means. Applicant's agent Mr. Sato - Figure 1 Figure 2 to: Refretsu Tsuyu Soku I (non-Kanshin (I'm a fan of five motions) B, I, TZ interval cooking between two Tanaka SO Time=to+r, +β11 Figure 4

Claims (1)

[Claims] In a microwave oven that cooks food by oscillating microwaves, there is a gas detection device that detects the concentration of gas generated from the food during heating and reduces the output as the concentration of the gas increases, and a calculation means for calculating the rate of change of the output of the gas detection device over time; a setting means for setting cooking constants α and β (<1) based on the weight and cooking method of the food and the output of the calculation means;
Maximum value V_m of the output of the gas detection device after heating the food
Maximum value detection means for detecting _a_x and output of the gas detection device from the start of heating to V_m_a_x-α・V_m_
A microwave oven, characterized in that it is provided with heating control means for controlling heating so that the total heating time becomes t_1+β·t_1, where t_1 is the time taken to become equal to a_x.