JP2020148351A - Gas cooking stove - Google Patents

Abstract

To provide a gas cooking stove which can accurately detect a flame, prevent a configuration of a gas burner from getting complicated, and facilitate cleaning of the gas burner.SOLUTION: A gas cooking stove comprises: a gas burner 2 which has many flame holes 28 on a peripheral wall; a top plate 6 which has a burner opening 6a exposing the gas burner 2; a burner ring 18 which covers a gap between the burner opening 6a of the top plate 6 and the gas burner 2; ignition devices 15 and 17 which ignite the gas burner 2; and a control device 12 which controls combustion of the gas burner 2. The gas cooking stove also has: a burner temperature sensor 26 which detects a temperature of the gas burner 2 from beneath the same; and a ring temperature sensor 16 which detects the temperature of a burner ring 18 from beneath the same. The control device 12 has a combustion state detection section 29 which detects a combustion state of the gas burner 2 on the basis of the temperatures detected by the burner temperature sensor 26 and the ring temperature sensor 16.SELECTED DRAWING: Figure 1

Description

The present invention relates to a gas stove.

Conventionally, the gas stove is cooked by the gas burner exposed on the top plate. The gas stove is provided with a thermocouple in order to detect the presence or absence of ignition at the time of ignition of the gas burner and the extinguishing of the flame during cooking. (For example, see Patent Document 1 below).

The thermocouple detects the formation of a flame by the electromotive force generated in contact with the flame of the gas burner. Therefore, the thermocouple is provided in the vicinity of the flame hole so that the thermocouple is surely in contact with the flame of the gas burner.

However, if a thermocouple is provided in the vicinity of the flame hole, spilled juice or the like generated during cooking tends to adhere to the thermocouple. If spilled juice or the like adheres to the thermocouple, the appearance may be deteriorated due to dirt, or the sensitivity of the thermocouple may be lowered. Then, even if an attempt is made to remove the dirt adhering to the thermocouple, the thermocouple protrudes in the vicinity of the gas burner, which is troublesome to clean.

Therefore, a thermocouple is placed below the burner head that is placed on the burner body to form a flame hole, and a convex portion for guiding the spilled juice is provided on the upper surface of the burner head to make the spilled juice a thermocouple. It is known that the guide is provided in a direction that does not adhere to (see Patent Document 2 below).

However, in this case, a space for accommodating the thermocouple is formed between the burner body and the burner head, and a flame hole for bringing the flame into contact with the thermocouple on the inner side (center side of the burner head) of this space. There is a disadvantage that the structure of the gas burner becomes complicated because it is necessary to form the gas burner.

Japanese Unexamined Patent Publication No. 60-233421 Japanese Unexamined Patent Publication No. 2000-18524

In view of the above points, an object of the present invention is to provide a gas stove capable of accurately detecting a flame without using a thermocouple.

In order to achieve such an object, the present invention comprises a gas burner having a large number of flame holes formed in the peripheral wall, a top plate having a burner opening for exposing the gas burner, and the burner opening of the top plate. A burner temperature sensor that detects the temperature of the gas burner from below the gas burner in a gas stove including a burner ring that covers between the gas burner, an ignition device that ignites the gas burner, and a control device that controls combustion of the gas burner. A ring temperature sensor for detecting the temperature of the burner ring from below the burner ring is provided, and the control device of the gas burner is based on the detection temperature of the burner temperature sensor and the detection temperature of the ring temperature sensor. It is characterized by including a combustion state detection unit that detects a combustion state.

By providing the gas burner with a flame hole, the heat of the flame of the flame hole when burning is transferred, and the temperature of the gas burner rises. Burnering also receives radiant heat from the flame formed in the flame holes of the gas burner. Therefore, when the gas burner is burning (when a flame is formed in the flame hole), the temperature of the burner ring also rises.

The control device of the present invention is provided with a combustion state detection unit, so that the combustion state of the gas burner is detected by using both the temperature of the gas burner and the temperature of the burning. As a result, the combustion state of the gas burner can be detected without providing a thermocouple. Since the thermocouple is not required, the gas burner can be easily cleaned without the inconvenience of spilled juice adhering to the thermocouple as in the conventional case.

Further, in the present invention, the combustion state detection unit of the control device has the presence or absence of a flame in the flame hole based on the change in the detected temperatures of both the burner temperature sensor and the ring temperature sensor after the gas burner is ignited. Is characterized by detecting.

As the combustion state of the gas burner, the presence or absence of a flame in the flame hole of the gas burner can be mentioned. When ignited after the ignition operation (when there is a flame), the temperature of the burner ring rises due to the radiant heat, and the temperature of the gas burner also rises due to the transfer of heat from the flame hole. When the gas burner is not ignited (when there is no flame), neither the burner ring temperature nor the gas burner temperature rises after the ignition operation, or the burner ring temperature and the gas burner temperature rise and start to decrease.

From the above, the present invention detects the presence or absence of a flame in the flame hole based on the change in the detected temperatures of both the burner temperature sensor and the ring temperature sensor. As a result, it is possible to accurately detect the formation of a flame in the flame hole of the gas burner without providing a thermocouple, and it is possible to easily detect the presence or absence of ignition of the gas burner and the extinguishment of the flame.

Further, in the present invention, the combustion state detection unit of the control device compares the detection temperatures of the burner temperature sensor and the ring temperature sensor with the preset temperatures corresponding to the thermal power of the gas burner. It is characterized in that the presence or absence of a flame in the flame hole is detected and the strength of the thermal power of the gas burner is detected.

As the combustion state of the gas burner, the strength of the thermal power of the gas burner can be mentioned. The temperature of the gas burner and the temperature of the burner ring are within different temperature ranges depending on the strength of the thermal power of the gas burner (the magnitude of the flame), and if stable combustion is obtained with the thermal power, the temperature fluctuation will be. small.

Therefore, in the present invention, the detected temperatures of the burner temperature sensor and the ring temperature sensor are compared with the temperatures within the temperature range corresponding to the thermal power of the gas burner. Thereby, the strength of the thermal power can be detected, and when the temperature fluctuation is large, the state where the gas burner is not ignited (the state without flame) can be detected.

The figure which shows typically the structure of the gas stove which is an embodiment of this invention. Explanatory side view of the gas burner in this embodiment. Explanatory sectional view which enlarges and shows the main part of the burner for a stove of FIG. The flowchart which shows an example of the control by a controller.

An embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the gas stove 1 of the present embodiment gives a burner 2 (gas burner), a controller 3 for controlling the burner 2, and a desired instruction and various settings to the controller 3 by being operated by a user. It is provided with an operation panel 4 including a group of switches for performing the operation. The burner 2 and the controller 3 are housed in a box-shaped stove body 5 whose part is shown by a virtual line in the drawing. The open upper surface of the stove body 5 is closed by the top plate 6.

Fuel gas is supplied to the burner 2 via the gas supply pipe 7. The gas supply pipe 7 includes a main electromagnetic valve 8 that opens and closes the gas supply pipe 7, a flow rate control valve 9 that adjusts the flow rate of fuel gas flowing through the gas supply pipe 7, and a flow rate control valve 9 when the valve is closed. An orifice 10 is provided to ensure a minimum flow rate of fuel gas. The original solenoid valve 8 is opened by energization under the control of the controller 3 and closed by stopping energization. The flow rate control valve 9 is opened and closed by the motor 11. The motor 11 is controlled by a combustion control unit 12 (control device) functionally provided in the controller 3. The combustion control unit 12 adjusts the opening degree of the flow rate control valve 9 via the motor 11.

A burner opening 6a is provided on the top plate 6. The trivet 13 is placed on the top plate 6 so as to surround the burner opening 6a.

At the center of the burner 2, a pot bottom temperature sensor 14 that comes into contact with the bottom of the cooking container W when the cooking container W such as a pot is placed on the trivet 13 is provided. The pot bottom temperature sensor 14 detects the temperature of the bottom of the cooking container W heated by the burner 2 and outputs a signal indicating the detected temperature.

Further, an ignition plug 15 and a ring temperature sensor 16 are provided inside the stove body 5 near the burner 2. The spark plug 15 is driven by the igniter 17 to discharge for ignition. The spark plug 15 and the igniter 17 correspond to the ignition device of the present invention.

The ring temperature sensor 16 is a non-contact sensor such as an infrared temperature sensor, detects the temperature of the burner ring 18 (see FIGS. 2 and 3) described later, and outputs a signal indicating the detected temperature.

As shown in FIG. 2, the burner 2 includes a mixing pipe portion 19 installed in the stove body 5 and a burner body 20 connected to the mixing pipe portion 19 and exposed on the top plate 6 through the burner opening 6a. The burner head 21 is detachably mounted on the burner body 20.

Further, as shown in FIGS. 2 and 3, the burner 2 includes a cover plate 22 that covers the upper part of the burner head 21 with a predetermined gap, and a burner that expands radially outward from the outer circumference of the burner body 20. It has a ring 18. The pot bottom temperature sensor 14 penetrates the cover plate 22 and projects upward.

A gas nozzle (not shown) faces the upstream end of the mixing pipe portion 19, and the fuel gas ejected from the gas nozzle and the primary air sucked from the upstream end of the mixing pipe portion 19 due to the jet of the fuel gas are mixed. A mixed gas is generated by mixing in the pipe portion 19.

As shown in FIG. 3, an annular distribution chamber 23 communicating with the mixing pipe portion 19 is formed inside the burner body 20. Further, the burner body 20 includes an annular surface 24 provided so as to cover the upper part of the distribution chamber 23. The annular surface 24 is formed in an annular shape so as to be inclined upward from the inside to the outside.

The burner head 21 is provided with an inner cylinder portion 25 formed in a tubular shape and extending vertically downward in the central portion, and the inner cylinder portion 25 closes the inside of the distribution chamber 23 of the burner body 20. The pot bottom temperature sensor 14 supported inside the stove body 5 by a support member (not shown) penetrates and stands inside the inner cylinder portion 25.

A burner temperature sensor 26 is provided at a position below the burner head 21. The burner temperature sensor 26 is a non-contact sensor such as an infrared temperature sensor, and detects the temperature of the burner head 21 via the inner cylinder portion 25. Since the burner temperature sensor 26 is located below the inner cylinder portion 25, it is not exposed on the top plate 6.

Further, an outer peripheral wall 27 projecting downward is integrally provided at the outer peripheral end of the burner head 21. The lower end surface of the outer peripheral wall 27 is in contact with the upper surface of the annular surface 24. As a result, the burner head 21 is provided on the burner body 20 via the outer peripheral wall 27.

The outer peripheral wall 27 is formed with a large number of grooves that radiate along the radial direction of the burner head 21. The lower end side of each groove is open, and when the lower end surface of the outer peripheral wall 27 abuts on the annular surface 24, a large number of flame holes 28 having the annular surface 24 as the lower surface are formed on the outer periphery of the burner head 5. .. The heat of the flame formed in the flame hole 28 is transferred to the burner head 21. The temperature of the burner head 21 at this time is detected by the burner temperature sensor 26 via the inner cylinder portion 25.

As shown in FIG. 3, the burner ring 18 is attached to the burner body 20 and covers the gap between the burner body 20 and the inner peripheral edge of the burner opening 6a in the top plate 6 from above. Since the burner ring 18 has a shape that extends to the outer periphery of the burner body 20, the burner ring 18 receives the radiant heat of the flame formed in the flame hole 28 of the burner 2. The temperature of the burner ring 18 at this time is detected by the ring temperature sensor 16. The ring temperature sensor 16 is located below the burner ring 18 and is not exposed on the top plate 6.

The combustion control unit 12 of the controller 3 has a combustion state detection unit 29 that detects the combustion state of the burner 2 based on the detection temperature of the ring temperature sensor 16 and the detection temperature of the burner temperature sensor 26 as a function.

Here, an example of detection of the combustion state of the burner 2 (detection of flame and detection of strength of thermal power) by the combustion control unit 12 and the combustion state detection unit 29 of the controller 3 will be described.

As shown in FIG. 4, when the use of the gas stove is started and the ignition operation is performed, the combustion control unit 12 performs the ignition process in STEP1. Due to the ignition process of the combustion control unit 12, the igniter 17 is activated to generate a spark discharge in the spark plug 15, and the original solenoid valve 8 is opened.

Next, the combustion state detection unit 29 starts sampling the respective temperatures using the burner temperature sensor 26 and the ring temperature sensor 16 in STEP2. Subsequently, the combustion state detection unit 29 determines in STEP 3 whether or not the detection temperature Tb of the burner temperature sensor 26 and the detection temperature Tr of the ring temperature sensor 16 have risen, and if so, proceeds to STEP 4. If it does not rise, proceed to STEP 8 and detect no flame.

Proceeding to STEP 4, the combustion state detection unit 29 acquires the thermal power instruction value. The thermal power indicated value is the thermal power set in the combustion control unit 12 based on the operation of the operation panel 4. In this embodiment, for convenience of explanation, two types of thermal power, "strong" or "weak", will be described.

The combustion state detection unit 29 that has acquired the thermal power instruction value proceeds to STEP 5, and the detection temperature Tb of the burner temperature sensor 26 and the detection temperature Tr of the ring temperature sensor 16 are the temperatures corresponding to the thermal power indication values acquired in STEP 4, respectively. Determine if it is within the range (whether it is at any temperature within the temperature range).

Here, STEP4 and STEP5 will be described in more detail. When the thermal power instruction value is "strong" (large thermal power) in STEP 4, the combustion control unit 12 determines the temperature value (temperature range) of the burner 2 and the burner ring 18 when the thermal power instruction value is "strong". The temperature value (temperature range) of is extracted from a storage unit (not shown). Then, in STEP 5, the combustion state detection unit 29 compares the temperature value (temperature range) of the burner 2 when the extracted thermal power indicated value is “strong” with the detection temperature Tb of the burner temperature sensor 26, and burners. The temperature value (temperature range) of 18 is compared with the detection temperature Tr of the ring temperature sensor 16. In the present embodiment, the temperature range when the thermal power indicated value is “strong” is “150 ° C <Tb <190 ° C” for the burner 2 and “140 ° C <Tb <160 ° C” for the burner ring 18.

Therefore, when the thermal power indicated value is "strong", the detection temperature Tb of the burner temperature sensor 26 is in the range of 150 ° C. to 190 ° C., and the detection temperature Tr of the ring temperature sensor 16 is 140 ° C. to 160 ° C. If it is within the temperature range, the process proceeds to STEP 10.

Further, when it is acquired in STEP 4 that the thermal power instruction value is "weak" (small thermal power), the combustion control unit 12 determines the temperature value (temperature range) of the burner 2 and the burner when the thermal power instruction value is "weak". The temperature value (temperature range) of the ring 18 is extracted from a storage unit (not shown). Then, in STEP 5, the combustion state detection unit 29 compares the temperature value (temperature range) of the burner 2 when the extracted thermal power indicated value is “weak” with the detection temperature Tb of the burner temperature sensor 26, and burners. The temperature value (temperature range) of 18 is compared with the detection temperature Tr of the ring temperature sensor 16. In the present embodiment, the temperature range when the thermal power indicated value is "weak" is "360 ° C. <Tb <400 ° C." for the burner 2 and "100 ° C. <Tb <120 ° C." for the burner ring 18.

Therefore, when the thermal power indicated value is "weak", the detection temperature Tb of the burner temperature sensor 26 is in the range of 360 ° C to 400 ° C, and the detection temperature Tr of the ring temperature sensor 16 is 100 ° C to 120. If it is within the temperature range, the process proceeds to STEP 10.

As described above, the burner ring 18 has a higher temperature when the thermal power instruction value is "strong" than the temperature when the thermal power instruction value is "weak", while the burner 2 has the thermal power instruction value "strong". The temperature when the thermal power indication value is "weak" is higher than the temperature at. This depends on the composition of the flame. That is, the flame formed in the flame hole 28 of the burner 2 is composed of an internal flame (reducing flame) having a temperature of about 300 ° C. to 500 ° C. and an external flame (oxidizing flame) having a temperature of 1500 ° C. to 1800 ° C. .. In the case of high heat, a large external flame is formed on the outside of the flame hole 28, the radiant heat received by the burner ring 18 is large, the temperature of the burner ring 18 rises, and an internal flame is formed close to the flame hole 28 to form a burner head. The temperature transmitted to 21 decreases. In the case of low heat, the radiant heat received by the burner ring 18 is small, the temperature of the burner ring 18 decreases, and the temperature transmitted to the burner head 21 in contact with the external flame increases. Is
In this way, the "strong" and "weak" of the thermal power can be determined by the temperature changes of the burner 2 and the burner ring 18, respectively.

In STEP 5, the combustion state detection unit 29 proceeds to STEP 6 when one or both of the detection temperature Tb of the burner temperature sensor 26 and the detection temperature Tr of the ring temperature sensor 16 are out of the respective temperature ranges described above. The combustion state detection unit 29 that has advanced to STEP 6 proceeds to STEP 7 if both the detection temperature Tb of the burner temperature sensor 26 and the detection temperature Tr of the ring temperature sensor 16 have not decreased. Proceeding to STEP 7, the combustion state detection unit 29 detects that there is a flame and returns to STEP 4.

In STEP 6, when both the detection temperature Tb of the burner temperature sensor 26 and the detection temperature Tr of the ring temperature sensor 16 are lowered, the combustion state detection unit 29 proceeds to STEP 8 and detects no flame.

The combustion state detection unit 29 that has progressed from STEP 5 to STEP 10 is within a range of allowable fluctuations between the detection temperature Tb of the burner temperature sensor 26 and the detection temperature Tr of the ring temperature sensor 16 (in this embodiment, Tb and Tr). If the fluctuations in the above are all less than ± 5 ° C., the process proceeds to STEP 11. By advancing to STEP 11, the combustion state detection unit 29 detects the presence of a flame, determines that a flame matching the indicated value of the thermal power is formed, determines the thermal power, and returns to STEP 4.

In STEP 10, the detection temperature Tb of the burner temperature sensor 26 and the detection temperature Tr of the ring temperature sensor 16 are not within the allowable fluctuation range (in the present embodiment, the fluctuations of Tb and Tr are not less than ± 5 ° C. ), The combustion state detection unit 29 proceeds to STEP 12 and detects a thermal power control error.

As described above, the presence or absence of a flame and the strength of the thermal power can be detected without using a thermocouple. The temperature used for determination in STEP 5 and STEP 10 is appropriately set based on the shape, structure, material, etc. of the burner 2 and the burner ring 18.

Then, when the combustion state detection unit 29 advances to STEP 8 or STEP 12, the combustion control unit 12 performs a fire extinguishing process in STEP 9. By the fire extinguishing process of the combustion control unit 12, an error notification is performed and the main solenoid valve 8 is closed.

As described above, the gas stove 1 of the present embodiment includes the ring temperature sensor 16, the burner temperature sensor 26, and the combustion state detection unit 29, so that the combustion state of the burner 2 can be detected without providing a thermocouple. Therefore, since the gas stove 1 of the present embodiment does not have a thermocouple, the thermocouple does not adhere to the thermocouple as in the conventional case, and the flame detection accuracy is not deteriorated due to the adhesion of the spilled juice. There is no need to perform troublesome work such as removing dirt adhering to the surface.

In the present embodiment, the temperature of the burner head 21 is detected by the burner temperature sensor 26, but the temperature detected by the burner temperature sensor 26 according to the present invention is not limited to the temperature of the burner head 21. That is, although not shown, a burner temperature sensor that detects the temperature of the burner body 20 may be provided, or a burner temperature sensor that detects the temperature of both the burner head 21 and the burner body 20 may be provided.

Further, as the ring temperature sensor 16 and the burner temperature sensor 26, in addition to the non-contact temperature sensor such as the infrared temperature sensor, for example, a contact type temperature sensor using a thermistor or the like can be used.

1 ... Gas stove, 2 ... Burner (gas burner), 6 ... Top plate, 6a ... Burner opening, 12 ... Combustion control unit (control device), 15 ... Spark plug (ignition device), 16 ... Ring temperature sensor, 17 ... Igniter (Ignition device), 18 ... Burner ring, 26 ... Burner temperature sensor, 28 ... Flame hole, 29 ... Combustion state detector.

Claims (3)

A gas burner having a large number of flame holes formed in the peripheral wall, a top plate having a burner opening for exposing the gas burner, a burner ring covering between the burner opening and the gas burner of the top plate, and the above. In a gas stove including an ignition device that ignites a gas burner and a control device that controls combustion of the gas burner.
A burner temperature sensor for detecting the temperature of the gas burner from below the gas burner is provided.
A ring temperature sensor for detecting the temperature of the burner ring from below the burner ring is provided.
The control device includes a combustion state detection unit that detects a combustion state of the gas burner based on the detection temperature of the burner temperature sensor and the detection temperature of the ring temperature sensor. The combustion state detection unit of the control device is characterized in that after igniting the gas burner, the presence or absence of a flame in the flame hole is detected based on changes in both detection temperatures of the burner temperature sensor and the ring temperature sensor. The gas stove according to claim 1. The combustion state detection unit of the control device compares the detected temperatures of the burner temperature sensor and the ring temperature sensor with the preset temperature corresponding to the thermal power of the gas burner, thereby forming the flame hole in the flame hole. The gas stove according to claim 1 or 2, wherein the presence or absence of a flame is detected and the strength or weakness of the thermal power of the gas burner is detected.