JP7117271B2 - heating cooker - Google Patents

Description

TECHNICAL FIELD The present invention relates to a heating cooker, and more particularly to a heating cooker suitable for detecting steam generated in a heating chamber and controlling heating means.

A heating cooker stores an object to be heated in a heating chamber, and cooks the object by controlling a heating means such as a magnetron or an electric heater based on an operator's operation instruction such as a heating instruction. . There is known a technique of arranging a steam sensor for detecting steam generated in a heating chamber and controlling a heating means based on the detection result of the steam sensor in order to cook an object to be heated. Such a technique is described, for example, in JP-A-9-79587.

Japanese Patent Application Laid-Open No. 9-79587

However, the distribution of steam to be detected is not uniform, and if the amount of steam in the vicinity of the steam sensor is different from the steam associated with the generation source, the target steam cannot be detected accurately. In particular, if there is a delay in the detection of steam with respect to the generation of steam, the object to be heated cannot be heated appropriately, resulting in a poor cooking finish.

It is an object of the present invention to solve the above problems and to provide a cooking device capable of appropriately detecting the generated steam and improving the cooking finish.

In order to achieve the above object, the present invention comprises a heating chamber containing an object to be heated, heating means for heating the object to be heated, a steam sensor for detecting steam generated in the heating chamber, and the steam sensor. Control means for controlling the heating means based on the detection, comprising a discharge passage for discharging the steam and a partition plate for partitioning at least a part of the discharge passage, separated by the partition plate The vapor sensor was placed on the spatially smaller side of one side of the discharge channel.

According to the present invention, it is possible to stably detect the steam generated in the heating chamber, and to improve the cooking finish.

1 is a front perspective view of a main body of a heating cooker according to an embodiment; FIG. AA sectional view of FIG. Explanatory drawing of the state in which the door of the heating cooker is opened and the inside of a main body can be seen. The perspective view of the exhaust duct of the heating cooker. FIG. 4 is a main cross-sectional view of the heating cooker in a state where an exhaust duct is attached. FIG. 4 is a main cross-sectional view of the heating cooker in a state where an exhaust duct is attached. Diagram showing a reference example of steam detection accuracy Diagram showing steam detection accuracy

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 8 described above.

FIG. 1 is a perspective view of the front side of the heating cooker of one embodiment. In FIG. 1, 5 is a door provided in front of the heating cooker, 1 is the main body of the heating cooker, 4 is a handle provided on the top of the door 5, and 6 is a heat-resistant glass window provided on the door 5. , 2 is an operation panel provided under the door 5, and 7 is a detachable water tank provided under the door 5, in which water necessary for producing steam is stored.

Further, 8 is input means provided on the operation panel 2, and is composed of a display section 9, an operation section 10, and a heat cooking start switch 11. As shown in FIG. By operating the operation unit 10, it is possible to set the heating method such as microwave heating or heater heating, the heating time, the set temperature for oven heating, and the like. 3 is an outer frame covering the upper surface and left and right side surfaces of the main body 1, 12 is an external exhaust duct provided on the upper back surface of the main body 1, and 13 is an external exhaust port provided on the upper surface of the external exhaust duct 12.

FIG. 2 is a cross-sectional view of the heating cooker of FIG. 1 taken along the line A--A. In FIG. 2, reference numeral 14 denotes a heating chamber in which food to be heated is accommodated. The heating chamber 14 is surrounded by a heating chamber bottom surface 14a, a heating chamber inner wall surface 14b, a heating chamber upper surface 14c, a heating chamber left wall surface 14e, and the like. 15 is a planar electric heater provided above the heating chamber 14, and 16 is two rod-like electric heaters provided in the rear of the bottom surface 14a of the heating chamber.

17 is a boiler provided on the back side of the left wall surface 14e of the heating chamber, and 17a is an ejection port for ejecting the steam generated by the boiler 17 to the heating chamber 14.

18 is a temperature/vapor sensor (such as a thermistor) that is placed in the rear right rear of the upper surface 14c of the heating chamber and is connected to the control unit 19 to detect the temperature of the heating chamber 14 and the vapor generated from the object to be heated. The resistance value changes accordingly. The control unit 19, which will be described later, converts the resistance value detected by the temperature/steam sensor 18 into a voltage, and the voltage value is confirmed in advance for the required temperature (set temperature) of the heating chamber 1. The power supply to the electric heaters 15 and 16 is adjusted so that the voltage value (control value) is set. Further, based on the steam detection signal detected by the temperature/steam sensor 18, the remaining heating time of the object to be heated is adjusted.

The detection of steam by the temperature/steam sensor 18 (simply referred to as steam sensor) will now be described. Steam is a cluster of tiny water droplets. Therefore, when a minute water particle touches the temperature/steam sensor 18, the temperature of the temperature/steam sensor 18 is stolen at that moment, and the resistance value, which is the detected value of the temperature/steam sensor 18, changes. Steam is detected by detecting that the voltage value obtained by converting this resistance value has changed within a predetermined time. Of course, it is possible to use sensors that detect vapor in other forms. For example, based on the fact that absorption characteristics differ when vapor is contained, a vapor sensor that detects vapor by applying absorption analysis may be used.

20 is a machine room provided between the bottom surface 14a of the heating chamber and the bottom plate 21 of the main body 1. As shown in FIG. In the machine room 20, a weight detection means 22, a magnetron 23, a waveguide 24, a rotating antenna 25, a rotating antenna driving means 26, an inverter board 40 and the like are arranged.

41 is a table plate supported by the weight detection means 22 .

As shown in FIG. 2, the bottom surface 14a of the heating chamber has a concave shape in the approximate center, and a rotating antenna 25 is installed therein. The light is diffused by the antenna 25 and radiated into the heating chamber 14 . Rotating antenna 25 is connected to the output shaft of rotating antenna driving means 26 .

FIG. 3 is a perspective view for explaining the internal structure of the heating cooker of this embodiment, in which the door 5 is opened, the outer frame 2 is omitted, and a part of the structure is shown transparently. In FIG. 3, 19 is a control unit for controlling the magnetron 23, the rotating antenna 25, the electric heater 15, etc., 27 is the heating chamber edge exposed in front of the main body 1 when the door 5 is opened, and 5a is inside the door 5. A protrusion 27a provided on the upper portion is a door switch that is pushed by the protrusion 5a when the door 5 is closed. 28a is an internal exhaust port provided in the upper portion of the rear plate 28, and 29 is an exhaust duct that guides exhaust air from the heating chamber 14 to the internal exhaust port 28c.

The exhaust duct 29 takes the steam from the heating chamber 14 through a duct inlet 29e. The duct inlet 29e is a portion of the heating chamber upper surface 14c close to the rear plate 28, and is formed of a plurality of small holes toward the center from the right end as viewed from the door 5 side. The introduced steam is exhausted from the duct exhaust port 29f. The duct exhaust port 29f is formed so as to come into contact with the rear plate 28 from the right end as viewed from the door 5 toward the center.

As can be seen from FIGS. 2 and 3, when the door 5 is closed, the door 5 comes into contact with the heating chamber rim 27, keeping the heating chamber 14 in a sealed state, preventing leakage of microwaves, and preventing heat and water vapor from the heater. to be contained. At this time, the convex portion 5a provided on the door 5 closes the contact of the door switch 27a, and when the door 5 is opened, the contact of the door switch 27a is opened. .

Next, the structure of the exhaust duct 29 will be described using the perspective view of the exhaust duct 29 in FIG. The exhaust duct 29 is a substantially box-shaped duct consisting of a top surface 29a, a side surface 29b, a side surface 29c, and a wall surface 29d. A duct exhaust port 29f is provided on the leeward side (rear plate side). A screen 29g is formed at the duct outlet 29f. After filling the heating chamber 14, the steam generated in the heating chamber 14 flows into the exhaust duct 29 from the duct inlet port 29e.

The exhaust passage formed by the exhaust duct 29 is divided into two chambers by a partition plate 30. As shown in FIG. The temperature/vapor sensor 18 is installed in the smaller of the two chambers, which is located on the edge side of the heating chamber.

Next, the mounting structure of the temperature/steam sensor 18 will be described with reference to FIG. The temperature/vapor sensor 18 is provided in the exhaust duct 29 where the detection part of the temperature/vapor sensor 18 hits the object of temperature measurement (steam and ambient temperature in this embodiment). The steam that has flowed into the exhaust duct 29 passes through the duct exhaust port 29f and is discharged to the outside of the heating chamber 1 through the external exhaust duct 12 and the external exhaust port 13. Further, the effect of the partition plate 30 that divides the area inside the exhaust duct provided in the exhaust duct 29 will be described later.

Furthermore, the mounting structure of the temperature/steam sensor 18 will be described with reference to FIG. The rear plate 28 consists of an inner rear plate 28b and an outer rear plate 28a. The outer rear plate 28a is in contact with the duct outlet 29f. This portion of the outer rear plate 28a in contact with the screen 29g is formed with long holes to allow ventilation.

A detection part (thermistor) of the temperature/vapor sensor 18 is formed so as to protrude from the side surface 29 b of the exhaust duct 29 . The steam generated from the heated part passes through the tip of the temperature/steam sensor 18 (thermistor serving as a detection part) in the steam flow path indicated by the arrow in the figure, and is exhausted from the duct outlet 29f. The exhaust steam passes through the external exhaust duct 12 and is discharged to the outside from the external exhaust port 13 .

Regarding the effect of the partition plate 30 provided in the exhaust duct 29 in the heating cooker configured as above, using FIGS. The time lag from when the sensor detects steam will be described in detail. Fig. 7 shows an installation environment in which the plate 30 that partitions the area in the exhaust duct is not provided, and the object to be heated is heated in a state where the top and left and right sides of the microwave oven are open and enclosed. With the partition plate 30 provided in the exhaust duct 29, microwave heating was performed under the same conditions as above.

The implementation of microwave heating will be described. The cooking time is determined based on the weight of the object to be heated detected by the weight detection means 22, and cooking is automatically performed. With this configuration, the user does not need to perform an operation to set the cooking time, so the operability is improved and the usability is improved.

Here, when the object to be heated is, for example, a drink, it is necessary to change the temperature after heating according to the type of the drink. Specifically, the temperature should be around 50 to 54°C when making sake kan as a drink, and around 60 to 65°C when warming milk as a drink other than sake. Therefore, if the cooking time is determined based only on the weight of the drink, depending on the type of drink, the drink may be overheated or underheated.

Therefore, a temperature/steam sensor 18 is provided, and the temperature state of the object to be heated is determined in real time based on the steam detection signal from the temperature/steam sensor. Specifically, when it is judged that steam is generated from the heated object, it is judged that the heated object will soon reach the appropriate temperature range, the cooking time is corrected based on the amount of steam, and the remaining cooking time decrease.

For example, when warming sake, the cooking time detected by the weight detecting means 22 is t, the time from the start of cooking until the sensor detects steam is t1, and the remaining cooking time when steam is detected is t2. In this case, the remaining cooking time t2 is optimized by a correction formula of t1×correction coefficient (which naturally varies depending on the type of drink and detected weight).

If it is judged that steam is not generated, the cooking time is set based on the weight. This configuration eliminates excess or deficiency caused by the cooking time based only on the weight of the object to be heated.

Microwave heating is performed by placing the object to be heated in the center of the heating chamber 14, which in this embodiment is water that stably generates steam, and steam is generated from the object to be heated (water), and the temperature/steam sensor 18 detects the steam. I went until

In the heating cooker of this embodiment in which the partition plate 30 is not provided in the exhaust duct 29, there is a time lag of about 20 to 60 seconds until the steam generated in the heating chamber 14 is detected by the sensor.

It is known that this time lag varies depending on the size of the heating chamber 14 and the distance between the object to be heated and the temperature/vapor sensor 18 .

Furthermore, there is a time lag of about 40 seconds between the closed condition and the open condition of the heating cooker, and this difference causes a difference in the finish temperature of the food (about 20°C) depending on the installation environment.

Next, an embodiment of the heating cooker in which the partition plate 30 is provided inside the exhaust duct 29 will be described with reference to FIG.

In the heating cooker provided with the partition plate 30 in the exhaust duct 29 of this embodiment, the time lag until the steam generated from the object to be heated is detected is approximately 17 seconds (approximately 16 seconds). Also, the steam detection time lag difference due to the installation environment is almost eliminated.

This is because the partition plate 30 divides the steam flowing into the exhaust duct 29 into the steam to be exhausted and the steam for sensor detection, and furthermore, the steam for detecting the steam is easily trapped in the exhaust duct 29, thereby improving the accuracy of steam detection and It was found that the responsiveness was greatly improved.

As described above, in the present embodiment, by providing the partition plate 30 flowing into the exhaust duct 29 in the exhaust duct 29 to which the temperature/steam sensor 18 is attached, the steam generated in the heating chamber 14 can be quickly heated again. Stable detection regardless of the environment in which the cooker is installed makes it possible to accurately detect the state of the object to be heated in real time regardless of the installation environment. It is possible to perform automatic control, and compared with the case where the partition plate 30 is not provided, it is possible to suppress uneven finishing of the object to be heated.

13 Magnetron 14 Heating Chamber 15 Electric Heater 18 Temperature/Steam Sensor 19 Controller 29 Exhaust Duct 30 Partition Plate

Claims (5)

A heating chamber containing an object to be heated, a heating means for heating the object to be heated, a steam sensor for detecting steam generated in the heating chamber, and a control for controlling the heating means based on the detection of the steam sensor. and means for discharging the steam, having a partition plate for partitioning at least a part of the discharge passage, and one side of the discharge passage partitioned by the partition plate is small in space. A heating cooker characterized in that the steam sensor is arranged on the side of the heating cooker. 2. The heating cooker according to claim 1, wherein said discharge path is configured as an exhaust duct for exhausting steam to the outside. 3. The heating cooker according to claim 2, wherein the exhaust duct allows fluid containing steam to flow in from below and exhaust sideways. 3. The heating cooker according to claim 1, wherein the inflowing fluid containing steam is separated by the partition plate. 2. The heating cooker according to claim 1, wherein said steam sensor is formed so as to protrude from a side surface of said discharge passage .

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