JP6857880B2 - Stove - Google Patents

Description

The present invention relates to a stove.

Conventionally, a stove that has been devised to ensure safety when using the stove is known. The gas stove disclosed in Patent Document 1 stops the gas when a sensor for detecting that clothes have entered the flammable area and a signal indicating that the clothes have entered the flammable area are input from the sensor. Equipped with a safety valve to extinguish the fire of the gas burner.

Japanese Patent No. 2886940

For example, when a plurality of sensors are arranged on the stove and the heating power of the burner is weakened or extinguished according to the measurement result of the sensors, if the heating power of the burner remains as it is, the subsequent cooking does not proceed smoothly. In order to prevent this, when the stove returns the burner to the original thermal power, it is necessary to ensure the safety of the user when returning the burner to the original thermal power.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a stove capable of adjusting the thermal power while ensuring the safety of the user.

The stove according to claim 1 of the present invention has a burner, a plurality of conroes arranged outside the burner, a transmitting unit and a receiving unit, and a transmitted wave transmitted from the transmitting unit is reflected by a measurement target. When the receiver receives the reflected wave and outputs a measurement result indicating the distance to the measurement target, and the gas flow rate in the gas passage of the burner is the first flow rate, the sensor outputs the measurement result. A first determination means for determining whether any of the output measurement results indicates the distance equal to or less than the first distance, and any of the measurement results output from the sensor by the first determination means. When it is determined that the distance is equal to or less than the first distance, the first flow control means for setting the gas flow rate to a second flow rate smaller than the first flow rate, and the gas flow rate by the first flow control means. Is controlled, the measurement results output from two or more sensors including the sensor that outputs the measurement result determined to indicate the distance equal to or less than the first distance by the first determination means. When the second determination means for determining whether or not the distance is equal to or greater than the second distance and all the measurement results output from the sensor by the second determination means indicate the distance equal to or greater than the second distance. When it is determined, the first determination means includes a second flow control means for setting the gas flow rate to the first flow rate, and the first determination means measures the measurement result output from the sensor for the first predetermined time. In the meantime, when it is considered to indicate the distance less than or equal to the first distance, it is determined that the measurement result indicates the distance less than or equal to the first distance, and the second determination means is from the two or more sensors. When all the output measurement results indicate the distance of the second distance or more during the second predetermined time, which is longer than the first predetermined time, the measurement result is the second distance or more. it you wherein it is determined that shows the said distance.
The stove according to claim 2 of the present invention has a burner, a plurality of conroes arranged outside the burner, a transmitting unit and a receiving unit, and a transmitted wave transmitted from the transmitting unit is reflected by a measurement target. When the receiving unit receives the reflected wave, a sensor that outputs a measurement result indicating the distance to the measurement target and the gas flow rate in the gas passage of the burner is the first flow rate, from the sensor. A first determination means for determining whether any of the output measurement results indicates the distance equal to or less than the first distance, and any of the measurement results output from the sensor by the first determination means. When it is determined that the distance is equal to or less than the first distance, the first flow control means for setting the gas flow rate to a second flow rate smaller than the first flow rate, and the gas flow rate by the first flow control means. Is controlled, the measurement results output from two or more sensors including the sensor that outputs the measurement result determined to indicate the distance equal to or less than the first distance by the first determination means. When the second determination means for determining whether or not the distance is equal to or greater than the second distance and all the measurement results output from the sensor by the second determination means indicate the distance equal to or greater than the second distance. When it is determined, the second flow control means for setting the gas flow rate to the first flow rate and the first determination means within a third predetermined time after the gas flow rate is controlled by the second flow rate control means. When it is determined that any of the measurement results output from the sensor indicates the distance equal to or less than the first distance, the control limiting means for causing the first flow control means to limit the execution of the control of the gas flow rate. To be equipped.

The stove according to claim 3 is characterized in that, in addition to the configuration according to claim 1 or 2 , the second distance is a distance larger than the first distance.

In addition to the configuration according to any one of claims 1 to 3, the stove according to claim 4 is provided in the gas passage and includes a valve for changing the gas flow rate, the first flow rate control means and the first. (Ii) The flow rate control means is characterized in that the gas flow rate is controlled by operating the valve according to the determination results of the first determination means and the second determination means.

The stove according to claim 1 has a plurality of sensors arranged outside the burner. The first determination means determines whether the measurement result output from any of the plurality of sensors is equal to or less than the first distance set for the sensor that outputs the measurement result. When the measurement result output from any of the plurality of sensors indicates the first distance or less, the first flow rate control means changes the gas flow rate from the first flow rate to the second flow rate. That is, the stove according to claim 1 can reduce the thermal power of the burner as the gas flow rate decreases, provided that the measurement result of any one of the plurality of sensors is the first distance or less. Therefore, it is prevented that the clothes of the user are ignited. Further, the stove according to claim 1 measures the gas flow rate after ensuring safety based on the measurement results by two or more sensors including the sensor that outputs the measurement result indicating the distance of the first distance or more by the first judgment means. Return to the first flow rate. In this case, for example, rather than returning the burner's thermal power to the original condition only on the condition that the subsequent measurement result by the sensor showing the measurement result indicating the first distance or less is the second distance or more, the user's clothes etc. The possibility of igniting foreign matter is sufficiently eliminated. Further, when all the measurement results of the two or more sensors indicate the second distance or more for the second predetermined time longer than the first predetermined time, the gas flow rate is restored. That is, the stove restores the firepower of the burner after taking sufficient time to surely determine that the user's clothes and the like have disappeared around the burner, so that the safety of the stove is improved. Therefore, the stove according to claim 1 can adjust the thermal power to ensure the safety of the user.
The stove according to claim 2 can reduce the thermal power of the burner as the gas flow rate decreases, provided that the measurement result of any one of the plurality of sensors is the first distance or less. Therefore, it is prevented that the clothes of the user are ignited. Further, the stove according to claim 2 measures the gas flow rate after ensuring safety based on the measurement results by two or more sensors including the sensor that outputs the measurement result indicating the distance of the first distance or more by the first judgment means. Return to the first flow rate. In this case, for example, rather than returning the burner's thermal power to the original condition only on the condition that the subsequent measurement result by the sensor showing the measurement result indicating the first distance or less is the second distance or more, the clothing of the user, etc. The possibility of igniting foreign matter is sufficiently eliminated. When cooking using a stove, for example, the user's clothes may repeatedly approach the sensor due to the user's actions such as repeatedly mixing the contents of the pot with chopsticks. In such a case, for example, if the thermal power of the burner is repeatedly reduced or extinguished according to the measurement result of the sensor, it may be difficult to keep the temperature of the contents of the pot at a desired temperature. In the stove according to claim 2, after the gas flow rate is controlled by the second flow rate control means, any of the measurement results output from the sensor by the first determination means within the third predetermined time is the first distance. Even if it is determined that the following distance is indicated, the first flow rate control means is restricted from executing the control of the gas flow rate. Therefore, the stove according to claim 2 can improve the usability of the stove while detecting that the clothes and the like of the user of the stove are close to the burner.

The stove according to claim 3 has a second distance larger than the first distance in addition to the effect of the invention according to claim 1 or 2 , so that the user's clothes and the like are surely worn from the periphery of the burner. You can restore the firepower after judging that you have moved away from.

The stove according to claim 4 is a burner by changing the gas flow rate according to the judgment by the first judgment means and the second judgment means in addition to the effect of the invention according to any one of claims 1 to 3. Adjust the firepower of. As a result, the stove according to claim 4 can prevent the user from igniting the clothes and the like, and can restore the thermal power after ensuring the safety of the user.

It is a perspective view of the stove 1. It is an exploded perspective view of the stove 1. It is a plan view of a stove 1. It is sectional drawing of an optical sensor 40. It is a figure which shows the structure of the thermal power control mechanism 60 provided in the gas supply pipe 27. This is a block showing the electrical configuration of the stove 1. It is a figure for demonstrating the detection range P of an optical sensor 40. It is a figure which shows the detection range as a whole of the optical sensors 4A to 4K in the stove 1. It is a figure which shows the data structure of the setting value table. It is a figure which shows the data structure of the specific setting value table. It is a figure which shows the data structure of the cooking mode table. It is a flowchart of a gas flow rate control process. It is a flowchart of a gas flow rate control process. It is a flowchart of setting value change processing.

Hereinafter, embodiments of the present invention will be described. Unless otherwise specified, the structure of the device described below is not intended to be limited thereto, but is merely an example of explanation. The drawings are used to illustrate the technical features that can be adopted by the present invention. In the following description, the left and right, front and back, and top and bottom indicated by arrows in the figure are used.

The structure of the stove 1 will be described with reference to FIGS. 1 to 3. The stove 1 is, for example, a built-in type stove that is installed by being dropped from above into an opening provided on the upper surface of a kitchen cabinet (not shown). The stove 1 includes a housing 2 and a top plate 3. The housing 2 is formed in a substantially rectangular parallelepiped shape, and the upper portion is open. The top plate 3 has a substantially rectangular shape in a plan view and is fixed to the opening 2A at the upper part of the housing 2. The top plate 3 is larger in the left-right direction than the housing 2 in a plan view. The top plate 3 includes a glass plate 11, a rear plate 12, and a frame body 13. The glass plate 11 is provided on the front side of the top plate 3, and the rear plate 12 is provided on the rear side of the top plate 3. The frame body 13 supports the glass plate 11 and the rear plate 12 from below, and holds the outer peripheral edge portion. The glass plate 11 and the rear plate 12 are integrated by the frame body 13 to form one plate. A black pattern is printed on the lower surface of the glass plate 11, and a rectangular transparent window portion is formed at a position corresponding to the optical sensors 4A to 4K described later.

The right burner 5 is provided on the right side of the upper surface of the glass plate 11, and is a burner for high heat that can burn gas with high calorie high heat when adjusted to the maximum heat. The left burner 6 is provided on the left side of the upper surface of the glass plate 11, and is a standard burner capable of burning gas with a lower calorie than the right burner 5 when adjusted to the maximum thermal power. A substantially cylindrical temperature detection unit 5A is provided in the center of the upper surface of the right burner 5 so as to be able to move in and out in the vertical direction, and is always urged upward by a spring (not shown). A substantially cylindrical temperature detection unit 5A is provided in the center of the upper surface of the left burner 6 so as to be able to move in and out in the vertical direction, and is constantly urged upward by a spring (not shown). A substantially cylindrical temperature detection unit 6A is provided in the center of the upper surface of the left burner 6 so as to be able to move in and out in the vertical direction, and is always urged upward by a spring (not shown). Thermistors 5B and 6B (see FIG. 6) for detecting the pot bottom temperature are stored inside each of the temperature detection units 5A and 6A, respectively. The thermistors 5B and 6B detect the pot bottom temperature via the upper wall portions of the temperature detecting portions 5A and 6A that come into contact with the pot bottom.

A large number of flame holes are provided on the side surface of the right burner 5, and an ignition electrode (not shown) of the igniter 35 and a thermocouple 5C (see FIG. 6) are installed in the vicinity of the flame holes so as to face the flame holes. When the igniter 35 is driven, a spark discharge is generated at the ignition electrode to ignite the gas ejected from the flame hole. The thermocouple 5C is heated by a flame formed in the flame hole to generate a thermoelectromotive force. Therefore, the stove 1 can detect a misfire in the right burner 5 based on the thermoelectromotive force generated in the thermocouple 5C. A large number of flame holes are also provided on the side surface of the left burner 6, and the ignition electrode (not shown) and the thermocouple 6C (see FIG. 6) of the igniter 36 are flame holes in the vicinity of the flame holes, as in the case of the right burner 5. It is installed so as to face the. When the igniter 36 is also driven, a spark discharge is generated at the ignition electrode and ignites the gas ejected from the flame hole. The thermocouple 6C is heated by a flame formed in the flame hole to generate a thermoelectromotive force. Therefore, the stove 1 can detect a misfire in the left burner 6 based on the thermoelectromotive force generated in the thermocouple 6C.

A grill exhaust port 10 is provided at the center of the rear plate 12 of the top plate 3. A cover 10A having a plurality of holes is installed in the grill exhaust port 10. A grill storage (not shown) is provided in the housing 2. The grill exhaust port 10 communicates with the grill storage. A grill burner (not shown) is provided in the grill chamber, and an igniter ignition electrode and a thermocouple (not shown) similar to the above are installed in the vicinity of the flame hole. A saucer stand (not shown) is stored in the grill. A saucer, a gridiron, a gridiron, etc. (not shown) are placed on the saucer. The saucer stand is connected to the lower part of the back surface of the grill door 14. The grill door 14 is provided in the center of the front surface of the housing 2, and opens and closes an opening provided in the front surface of the grill storage. A handle 14A is provided at the lower part of the front surface of the grill door 14. By grasping the handle 14A and pulling out the grill door 14 forward, the user can simultaneously pull out the saucer, the gridiron, the gridiron, etc. to the outside of the grill.

In the center of the front surface of the housing 2, in the area on the right side of the grill door 14, ignition buttons 15, 16, thermal power adjusting levers 18, 19, an operation panel 25, and the like are provided. The ignition button 15 is provided adjacent to the right side of the grill door 14, and by pressing the ignition button 15, the right burner 5 is ignited and extinguished. The ignition button 16 is provided on the right side of the ignition button 15, and when pressed, an operation of igniting and extinguishing a grill burner (not shown) provided in the grill chamber is performed. The grill burner is composed of an upper-fire grill burner and a lower-fire grill burner (not shown) provided above and below the left and right side walls in the grill chamber, respectively.

The thermal power adjusting lever 18 is provided above the ignition button 15 and adjusts the thermal power of the right burner 5 by a rotation operation in a substantially horizontal direction. The thermal power adjusting lever 19 is provided above the ignition button 16, and is provided with an upper-fire adjusting knob 19A and a lower-fire adjusting knob 19B at the top and bottom. The top-fire adjustment knob 19A adjusts the heating power of the top-fire grill burner by rotating the top-fire adjustment knob 19A in a substantially horizontal direction. The lower heat adjustment knob 19B adjusts the heating power of the lower heat grill burner by rotating the lower heat in a substantially horizontal direction. The operation panel 25 is provided so as to be rotatable in the front-rear direction below the ignition buttons 15 and 16. The operation panel 25 includes a plurality of buttons for receiving inputs of various operations, an LED for notifying according to various operations, and the like.

On the other hand, in the center of the front surface of the housing 2, an ignition button 17, a thermal power adjusting lever 20, and the like are provided in the area on the left side of the grill door 14. The ignition button 17 is provided adjacent to the left side of the grill door 14, and when pressed, the left burner 6 is ignited and extinguished. The thermal power adjusting lever 20 is provided above the ignition button 17, and adjusts the thermal power of the left burner 6 by a rotation operation in a substantially horizontal direction.

The stove 1 includes a sensor unit 4. The sensor unit 4 includes a plurality of (11 in this embodiment) optical sensors 4A to 4K. The optical sensors 4A to 4K have the same configuration. In the following description, when the optical sensors 4A to 4K are generally described, they are referred to as an optical sensor 40. The optical sensor 40 is a known reflection type ranging sensor. The optical sensors 4A to 4K are provided inside the housing 2 and are arranged outside the right burner 5 and the left burner 6. The optical sensors 4A to 4K are located in the opening 2A of the housing 2 in a plan view. When the top plate 3 is fixed to the housing 2, the optical sensors 4A to 4K are located directly below the top plate 3. The optical sensors 4A to 4K output a detection wave from the window portion of the glass plate 11 toward the upper side of the top plate 3 to detect foreign matter approaching the right burner 5 and the left burner 6. As foreign substances, the hands and arms of the user of the stove 1 and the sleeve tips of the user's clothes are assumed. The "outside" of the right burner 5 and the left burner 6 in the present invention means the right burner in a direction in which the right burner 5 and the left burner 6 intersect in the vertical direction such as front, rear, left, right, and surroundings. 5 and the part located outside the left burner 6.

Of the optical sensors 4A to 4K, the optical sensors 4A to 4I are arranged side by side from the right end to the left end of the stove 1 in front of the right burner 5 and the left burner 6. The area where the optical sensors 4A to 4I are arranged is defined as the detection area C. The optical sensors 4A to 4I are arranged along the left-right direction in the detection region C to form an array. The optical sensors 4A to 4I are arranged in the left-right direction at substantially the same interval when viewed from the front. When viewed in a plan view, the optical sensors 4B, 4E, and 4H are arranged at the same position in the front-rear direction and in the left-right direction. The optical sensors 4A, 4C, 4G, and 4I are arranged in the left-right direction at a position slightly behind the optical sensors 4B, 4E, and 4H in the front-rear direction. The optical sensors 4D and 4E are arranged in the left-right direction at a position slightly behind the optical sensors 4A, 4C, 4G and 4I in the front-rear direction. The range in which the positions of the optical sensors 4A to 4I are displaced in the front-rear direction is smaller than the range in which the optical sensors 4A to 4I are displaced in the left-right direction. Therefore, the detection area C in which the optical sensors 4A to 4I are arranged extends long in the left-right direction. That is, the optical sensors 4A to 4I form an arrangement in which the optical sensors 4A to 4I are separately arranged in the left-right direction while allowing some positional deviation in the front-rear direction.

Of the optical sensors 4A to 4I, the optical sensors 4A to 4D and J are used to control the gas flow rate supplied to the right burner 5. Among them, the optical sensors 4A to 4D are located at positions from diagonally forward right to diagonally forward left of the right burner 5 in a plan view, and are substantially along the virtual line D1 forming a gentle arc along the circumferential direction of the right burner 5. Line up at intervals. The optical sensors 4A to 4D are arranged outside the outer circumference of the frying pan in a plan view when, for example, a frying pan having a diameter of 28 cm is placed on the trivet 7 of the right burner 5.

The optical sensor 4J is arranged obliquely to the left of the right burner 5 and substantially behind the optical sensor 4D. The arrangement position of the optical sensor 4J is a position closer to the right burner 5 than the optical sensors 4A to 4D in a plan view. In other words, the optical sensor 4J is located behind the optical sensors 4A to 4D in the front-rear direction with respect to the right burner 5, and is located inside the optical sensors 4A to 4D in the radial direction of the right burner 5. The optical sensor 4J is provided to reliably detect the approach of the foreign matter when the foreign matter approaches the right burner 5 with respect to the optical sensors 4A to 4D lined up along the virtual line D1.

The optical sensors 4F to 4I, 4K are used to control the gas flow rate supplied to the left burner 6. Among them, the optical sensors 4F to 4I are located at positions from the diagonally front right to the diagonally front left of the left burner 6 in a plan view, and are approximately along the imaginary line D2 forming a gentle arc along the circumferential direction of the left burner 6. Line up at intervals. The optical sensors 4F to 4I are arranged outside the outer circumference of the frying pan in a plan view when, for example, a frying pan having a diameter of 28 cm is placed on the trivet 8 of the left burner 6.

The optical sensor 4K is arranged obliquely to the right of the left burner 6 and substantially behind the optical sensor 4F. The arrangement position of the optical sensor 4K is a position closer to the left burner 6 than the optical sensors 4F to 4I in a plan view. In other words, the optical sensor 4K is located behind the optical sensors 4F to 4I in the front-rear direction with respect to the left burner 6, and is located inside the optical sensors 4F to 4I in the radial direction of the left burner 6. The optical sensor 4K is provided to reliably detect the approach of the foreign matter when the foreign matter comes closer to the left burner 6 than the optical sensors 4F to 4I lined up along the virtual line D2.

The optical sensor 4E is used to control the gas flow rate supplied to the right burner 5 and the left burner 6. The optical sensor 4E is arranged between the optical sensor 4D and the optical sensor 4F at substantially the center in the left-right direction. When viewed in a plan view, the optical sensors 4E are arranged in the horizontal direction at the same positions as the optical sensors 4B and 4H in the front-rear direction. The optical sensor 4E is arranged at a position farther from the right burner 5 and the left burner 6 than the other optical sensors 4A to 4D and 4F to 4I.

The optical sensor 40 will be described. As shown in FIG. 4, the optical sensor 40 receives the reflected wave reflected by the foreign matter from the detection wave transmitted from the transmitting unit at the receiving unit, and applies a triangular ranging method to measure the distance to the foreign matter. It is a sensor. The optical sensor 40 has a substantially rectangular parallelepiped housing 49 made of a light-shielding resin. A light emitting element 41, a light projecting lens 43, a light receiving element 44, a condensing lens 46, and a control IC 47 are provided in the housing 49. The light emitting element 41, the light receiving element 44, and the control IC 47 are mounted on the lead frame 48. The lead frame 48 is formed in the shape of an elongated plate and is provided at the bottom of the housing 49. The housing 49 is formed long in the direction in which the lead frame 48 extends. Hereinafter, the direction in which the lead frame 48 extends is referred to as a stretching direction.

The light emitting element 41 is an infrared light emitting LED that emits infrared light as a detection wave. A laser diode or the like may be used for the light emitting element 41. The light emitting element 41 is provided on the mounting surface 48A at one end of the lead frame 48. The emission direction in which infrared light is emitted from the light emitting element 41 is a direction orthogonal to the mounting surface 48A and away from the mounting surface 48A. The light receiving element 44 is an optical position sensor (PSD) that outputs light according to the light receiving position of the reflected light received as a reflected wave. A CMOS image sensor or the like may be used for the light receiving element 44. The light receiving element 44 is provided on the mounting surface 48A at the other end of the lead frame 48. In the housing 49, the light emitting element 41 is located at the bottom of the housing 49 and one end in the stretching direction, and the light receiving element 44 is located at the bottom of the housing 49 and the other end in the stretching direction. The control IC 47 is provided between the light emitting element 41 and the light receiving element 44 on the mounting surface 48A of the lead frame 48. The periphery of the light emitting element 41 is sealed with a translucent resin 42. The periphery of the light receiving element 44 and the control IC 47 is sealed with a translucent resin 45.

The projection lens 43 is provided in the housing 49 in front of the light emitting element 41 in the emission direction and at the top of the housing 49. The projection lens 43 converges the infrared light incident from the light emitting element 41 in a beam shape and emits it in the emission direction. The condenser lens 46 is provided in the housing 49 in front of the light receiving element 44 in the emission direction and in the middle portion between the top and bottom of the housing 49. The condenser lens 46 collects the reflected light reflected by a foreign substance on the light receiving surface of the light receiving element 44.

The control IC 47 incorporates a constant voltage circuit, an oscillation circuit, a drive circuit, a signal processing circuit, and an output circuit (not shown). The constant voltage circuit steps down the input voltage to generate a constant output voltage and supplies it to the signal processing circuit. The oscillating circuit oscillates at a predetermined frequency. The drive circuit intermittently drives the light emitting element 41 in accordance with the oscillation of the oscillation circuit at the time of one distance measurement, and emits infrared light a plurality of times. When the light receiving element 44 receives the reflected light reflected by the foreign matter, the output of the light receiving element 44 changes significantly in synchronization with the emission timing of the infrared light. The signal processing circuit acquires the current output obtained by sensing the light by the light receiving element 44, extracts the current value change synchronized with the emission timing of the infrared light, performs arithmetic processing to obtain the average value, and obtains the arithmetic result. Output to the output circuit. The output circuit generates a voltage of a magnitude corresponding to the calculation result and outputs it as a detection signal according to the distance to the foreign matter. When the light receiving element 44 is a CMOS image sensor, the control IC 47 may be included in the CMOS image sensor.

The optical sensor 40 having the above configuration measures the distance to a foreign object as follows, and outputs a detection signal indicating a voltage value (hereinafter, referred to as “measured voltage value”) according to the distance. When the optical sensor 40 detects a foreign matter B1 separated by a distance L1 in front of the light emitting element 41 in the emission direction, the angle of the reflected light emitted from the light emitting element 41 toward the light receiving element 44 among the reflected light reflected by the foreign matter B1. The reflected light reflected by is indicated by the reflected light R1 in the figure. The position where the reflected light R1 is refracted by the condensing lens 46 and condensed on the light receiving surface of the light receiving element 44 is defined as the condensing region F1. In FIG. 4, the refraction of light by the light projecting lens 43 and the condensing lens 46 is not shown for convenience of explanation. When the foreign matter B2 is located at a distance L2 closer than the distance L1, among the reflected light emitted by the light emitting element 41 and reflected by the foreign matter B2, the reflected light reflected at an angle toward the light receiving element 44 is shown in the figure. , Reflected light R2. The condensing region F2 in which the reflected light R2 is refracted by the condensing lens 46 and condensed on the light receiving surface of the light receiving element 44 collects infrared light with respect to the emission position F0 emitted from the light emitting element 41 in the stretching direction. It is located farther than the optical region F1. The light receiving element 44 has a resistance value different depending on the light collecting region on the light receiving surface, and outputs a current having a magnitude corresponding to the resistance value at the time of distance measurement. Therefore, the stove 1 can obtain the measured voltage value indicated by the detection signal output by the optical sensor 40 and perform an operation based on the triangular ranging method to obtain the distance between the optical sensor 40 and the foreign matter.

The thermal power control mechanism 60 will be described with reference to FIG. The gas supply pipe 27 of the right burner 5 is provided with a thermal power control mechanism 60 in order to improve the cooking performance and safety of the stove 1. The upstream end of the gas supply pipe 27 is connected to the gas inlet (not shown) of the stove 1, and the downstream end is connected to the gas inlet (not shown) of the thermal power adjusting mechanism 30. The thermal power adjusting mechanism 30 operates in conjunction with the operation of the ignition button 16 and the thermal power adjusting lever 18, and adjusts the ignition, fire extinguishing, and thermal power of the right burner 5.

The thermal power control mechanism 60 includes a plurality of flow paths and a plurality of solenoid valves. The gas supply pipe 27 includes two bypass pipes 28 and 29. The bypass pipe 28 is connected between the branch portion 65 provided in the gas supply pipe 27 and the merging portion 66. The bypass pipe 29 is connected between the branch portion 67 provided in the bypass pipe 28 and the merging portion 68.

A safety valve 64 is provided on the upstream side of the branch portion 65 of the gas supply pipe 27. In the figure, the safety valve is represented by "SV". A solenoid valve 61 is provided between the branch portion 65 and the merging portion 66 of the gas supply pipe 27. In the figure, the solenoid valve is represented by "KSV". A solenoid valve 62 is provided between the branch portion 67 and the merging portion 68 of the bypass pipe 28. A solenoid valve 63 is provided between the merging portion 66 and the thermal power adjusting mechanism 30. The solenoid valves 61 and 62 are keep solenoid valves for adjusting the gas flow rate. The solenoid valve 63 is a keep solenoid valve for shutting off gas. Therefore, the responsiveness of adjusting the gas flow rate by the solenoid valves 61 to 63 is improved.

The stove 1 opens and closes the solenoid valves 61 and 62, respectively, and adjusts the gas flow rate flowing through the thermal power adjusting mechanism 30 in three stages of a first flow rate, a second flow rate, and a third flow rate. When the solenoid valves 61 and 62 are both open, the first flow rate of gas flows through the gas supply pipe 27 and the bypass pipes 28 and 29 to the thermal power adjusting mechanism 30. When either one of the solenoid valves 61 and 62 (solenoid valve 62 in this embodiment) is closed, a second flow rate of gas flows through the gas supply pipe 27 and the bypass pipe 29 to the thermal power adjusting mechanism 30. When the solenoid valves 61 and 62 are closed together, a third flow rate of gas flows through the bypass pipe 29 to the thermal power adjusting mechanism 30. As a result, when the gas flow rate flowing through the thermal power adjusting mechanism 30 is adjusted to the maximum by the thermal power adjusting lever 18 (see FIG. 1), the thermal power is adjusted to three stages of low thermal power, medium thermal power, and high thermal power. The first flow rate corresponds to high heat power, the second flow rate corresponds to medium heat power, and the third flow rate corresponds to low heat power. The medium thermal power corresponding to the second flow rate is the thermal power between the high thermal power and the low thermal power, and the magnitude of the thermal power varies. The second flow rate is preferable as long as it is a gas flow rate that can maintain the heat power that can give a heat amount that does not easily affect cooking while suppressing the heat power to the extent that the flame does not protrude from the bottom of the pot.

The solenoid valves 61 and 62 are operated by the CPU 71 (see FIG. 6) of the control circuit 70, such as the detection result of the pot bottom temperature by the thermistor 5B, the detection result of foreign matter by the optical sensors 4A to 4E, 4J, the time after ignition, etc. It is controlled according to each. Similarly, the operation of the solenoid valve 63 and the safety valve 64 is also controlled by the CPU 71. Similar to the right burner 5, the gas supply pipe (not shown) of the grill burner is also provided with a safety valve 64 and solenoid valves 61 to 63, and the operation is controlled by the CPU 71. The gas supply pipe (not shown) of the left burner 6 is not provided with the bypass pipe 28 and the solenoid valve 62. The stove 1 opens and closes the solenoid valve 61 corresponding to the left burner 6, and changes the gas flow rate flowing through the thermal power adjusting mechanism 30 corresponding to the left burner 6 to the first flow rate (corresponding to high thermal power) and the third flow rate (to weak thermal power). Correspondence) Adjust in two steps. The safety valve 64 is opened in conjunction with the pressing of the ignition button 15.

The electrical configuration of the stove 1 will be described with reference to FIG. The stove 1 includes a control circuit 70. The control circuit 70 includes a CPU 71, a ROM 72, a RAM 73, a non-volatile memory 74, a timer (not shown), an I / O interface, and the like. The timer is operated by a program. The CPU 71 controls various operations of the stove 1 in an integrated manner. The ROM 72 stores various programs of the stove 1 including a gas flow rate control process and a set value change process (see FIGS. 12 to 14). The RAM 73 temporarily stores various types of information. The non-volatile memory 74 stores various parameters including a set value table, a specific set value table (see FIGS. 9 and 10), a cooking mode table (see FIG. 11), and the like.

The control circuit 70 includes a power supply circuit 81, a switch input circuit 82, a thermistor input circuit 83, a thermocouple input circuit 84, an igniter circuit 85, a sensor input circuit 86, 87, a buzzer circuit 88, a safety valve circuit 90, and an electromagnetic valve circuit 91. The operation panel 25 and the like are connected to each other. The power supply circuit 81 steps down the alternating current (for example, 100V) supplied from the power supply 23 to direct current (for example, 5V), rectifies it, and supplies electric power to various circuits. In the figure, the power supply is represented by "AC". The switch input circuit 82 detects the pressing of the ignition buttons 15 to 17 and inputs them to the power supply circuit 81 and the control circuit 70. In the figure, the ignition button is represented by "SW". The thermistor input circuit 83 inputs the detected values from the thermistors 5B and 6B to the control circuit 70. In the figure, the thermistor is represented by "TH". The thermocouple input circuit 84 inputs the detected values (signals corresponding to the thermoelectromotive force) from the thermocouples 5C and 6C to the control circuit 70. In the figure, the thermocouple is represented by "TC". The igniter circuit 85 drives the igniter 35 of the right burner 5 and the igniter 36 of the left burner 6 based on the control signal of the CPU 71, respectively. In the figure, the igniter is represented by "IG". Further, in FIG. 6, the thermistor, thermocouple, and igniter provided in the grill burner are omitted.

Each detection signal of the temperature detection units 5A and 6A is input to the sensor input circuit 86. Each detection signal of the optical sensors 4A to 4K is input to the sensor input circuit 87. The buzzer circuit 88 drives the piezoelectric buzzer 77 based on the control signal of the CPU 71. The safety valve circuit 90 opens and closes the safety valve 64 under the control of the CPU 71. The solenoid valve circuit 91 opens and closes the solenoid valves 61 to 63 under the control of the CPU 71. The operation panel 25 is used for setting a timer by the user, inputting a selection of thermal power control according to the cooking content, and turning on / off the LED according to the control content of the CPU 71.

The ignition buttons 15 to 17 are connected in parallel to the switch input circuit 82 and the power supply circuit 81, respectively. When any one of the ignition buttons 15 to 17 is pressed by the user, electric power is supplied from the power supply circuit 81 to various circuits, and the power of the stove 1 is turned on. The switch input circuit 82 detects which of the ignition buttons 15 to 17 is pressed, and inputs the detection signal to the control circuit 70. As a result, the CPU 71 determines which ignition button 15 to 17 is pressed to turn on the power, and controls the operation of the corresponding burner sensors and the various valves.

When the optical sensor 40 detects a foreign substance approaching the right burner 5 and the left burner 6, the CPU 71 of the stove 1 of the present embodiment operates the solenoid valves 61 and 62 to change the gas flow rate from the first flow rate to the second flow rate. Control is performed to reduce the flow rate or the third flow rate. The light emitting element 41 of the optical sensor 40 is arranged so that the emission direction of infrared light is directed toward the upper side of the stove 1 (see FIG. 2). When the foreign matter is located above (the direction in which the infrared light is emitted from the light emitting element 41), the optical sensor 40 outputs a detection signal according to the distance to the foreign matter. On the other hand, when a threshold value is set for the magnitude of the detection signal of the optical sensor 40 and a process of determining whether or not the distance to the foreign matter is equal to or less than a predetermined distance is performed, the foreign matter detection range P (FIG. 7) (See) has three properties as described below.

The first characteristic is that the optical sensor 40 has a wide detection range P in which foreign matter can be detected on the side opposite to the light receiving element 44 with respect to the light emitting element 41 in the stretching direction. Have. This characteristic is a characteristic based on the range of the emission angle of infrared light that can be emitted from the light emitting element 41 or the range of the incident angle of the reflected light that can be incident on the light receiving element 44. In the following description, the direction in which the light receiving element 44 faces the light emitting element 41 in the stretching direction is referred to as an arrangement direction for convenience.

As shown in FIG. 7, when the foreign matter B4 is located at a distance L3 in front of the light emitting element 41 in the emission direction, the infrared light from the light emitting element 41 is reflected by the foreign matter B4 at an angle toward the light receiving element 44. The reflected reflected light R4 is refracted by the condensing lens 46 and condensed in the condensing region F3 of the light receiving element 44. In FIG. 7, the refraction of light by the light projecting lens 43 and the condensing lens 46 is not shown for convenience of explanation. The optical sensor 40 outputs a detection signal indicating a measured voltage value corresponding to the distance L3.

When the foreign matter B5 is located at a distance L3 in front of the emission direction and between the light emitting element 41 and the light receiving element 44 in the stretching direction, the infrared light from the light emitting element 41 is reflected by the foreign matter B5, and among them The reflected light R5 reflected at an angle toward the light receiving element 44 is condensed by the condensing lens 46 in the same condensing region F3 as the reflected light R4 of the foreign matter B4. Therefore, the optical sensor 40 outputs a detection signal indicating the measured voltage value corresponding to the distance L3 as the detection result of the foreign matter B5.

When the foreign matter B6 is located at a distance L3 in front of the emission direction, is located on the opposite side of the light receiving element 44 from the light emitting element 41 in the stretching direction, and is located farther than the distance G1 from the light emitting element 41, the foreign matter B6 is reflected. Light cannot enter the light receiving element 44. Therefore, the optical sensor 40 cannot detect the foreign matter B6.

On the other hand, if the foreign matter B7 is located at a distance L3 in front of the emission direction, is located on the arrangement direction side of the light emitting element 41 in the stretching direction, and is located within a distance G2 larger than the distance G1, the infrared from the light emitting element 41. The light is reflected by the foreign matter B7, and the reflected light R6 reflected at an angle toward the light receiving element 44 can be incident on the light receiving element 44. Therefore, the optical sensor 40 can detect the foreign matter B7. However, the reflected light R6 is refracted by the condensing lens 46, so that the reflected light R6 is condensed at a position different from that of the condensing region F3. Therefore, the detection signal output by the optical sensor 40 indicates the measured voltage value corresponding to the distance to the foreign matter B7 being less than the distance L3. As described above, the optical sensor 40 has a characteristic that the detection range P capable of detecting foreign matter in the stretching direction is larger on the arrangement direction side than the light emitting element 41.

As a second characteristic, the optical sensor 40 has a characteristic that when the foreign matter is located closer to the arrangement direction than the light emitting element 41 in the stretching direction, the distance at which the foreign matter can be detected is long in the emission direction. This characteristic is based on the fact that the optical sensor 40 cannot correctly detect the distance to the foreign matter when the foreign matter is not directly in front of the light emitting element 41 in the emission direction. As shown in FIG. 4, when the foreign matter B3 is located at the distance L1 and is located closer to the arrangement direction than the light emitting element 41 in the stretching direction, the infrared light from the light emitting element 41 is reflected by the foreign matter B3. The reflected light R3 reflected at an angle toward the light receiving element 44 may pass through the condenser lens 46 in the same optical path as the reflected light R2 of the foreign matter B2 and enter the light receiving element 44. In this case, since the reflected light R3 of the foreign matter B3 collects light in the same region as the light collecting region F2 of the reflected light R2, the optical sensor 40 uses the same measurement as the foreign matter B2 located at the distance L2 as a detection signal of the foreign matter B3. Outputs a detection signal indicating the voltage value.

Therefore, as shown in FIG. 7, it is reflected by the foreign matter B8 located on the arrangement direction side of the light emitting element 41 in the stretching direction and located at a distance L4 in front of the emitting direction, and is reflected at an angle toward the light receiving element 44. The optical path of the reflected light R7 may coincide with the optical path of the reflected light R8 reflected by the foreign matter B9 located at a distance L3 ahead of the emission direction and reflected at an angle toward the light receiving element 44. When the reflected light R8 of the foreign matter B9 is focused in the focusing region F3, the reflected light R7 of the foreign matter B8 following the same optical path is also focused in the focusing region F3. In this case, the optical sensor 40 outputs a detection signal indicating the measured voltage value corresponding to the distance L3 as the detection signal of the foreign matter B8. As described above, the optical sensor 40 has a characteristic that the detection range P capable of detecting foreign matter in the emission direction is larger on the arrangement direction side than the light emitting element 41.

As a third characteristic, the optical sensor 40 has a characteristic that the foreign matter cannot be detected when the foreign matter is located at a position deviated from the position of the light emitting element 41 in the direction orthogonal to the stretching direction and orthogonal to the emitting direction. .. This characteristic is based on the positional relationship in which the light emitting element 41 and the light receiving element 44 are arranged in the stretching direction. Therefore, as described above, the foreign matter detection range P by the optical sensor 40 has a predetermined width in the stretching direction in which the light emitting element 41 and the light receiving element 44 are aligned, and is substantially substantially in the direction orthogonal to the stretching direction and the emitting direction. It is invalid.

As shown in FIGS. 1 to 3, the optical sensor 40 having the above characteristics is provided on the stove 1 with the emission direction facing upward. The optical sensors 4A to 4D arranged along the virtual line D1 and the optical sensors 4F to 4I arranged along the virtual line D2 are arranged in different arrangement directions. Each of the arrangement orientations of the optical sensors 4A to 4D has a directional component in the direction from the left side to the right side along the arc formed by the virtual line D1. That is, the arrangement directions of the optical sensors 4A to 4D are the directions of the tangents of the virtual line D1 at the positions where the optical sensors 4A to 4D are arranged, and face the right side of the stove 1 (see FIG. 8A). On the other hand, the arrangement directions of the optical sensors 4F to 4I have directional components in the direction from the right side to the left side along the arc formed by the virtual line D2. That is, the arrangement directions of the optical sensors 4F to 4I are the directions of the tangents of the virtual lines D2 at the positions where they are arranged, and they face the left side of the stove 1. Further, the arrangement direction of the optical sensor 4E is along the left-right direction and faces the left side of the stove 1 (see FIG. 8A).

As shown in FIG. 8A, the optical sensors 4A to 4I set the arrangement direction along the virtual lines D1 and D2 based on the third characteristic, and the arrangement direction as a whole has a directional component in the left-right direction. It is arranged in a holding state. As a result, as shown in FIG. 8B, the detection range P of the optical sensors 4A to 4I in the detection region C is expanded more widely in the left-right direction. In other words, the detection range P of the optical sensors 4A to 4I is provided in a fence shape extending in the left-right direction in the detection area C in front of the right burner 5 and the left burner 6. Therefore, the optical sensors 4A to 4I can expand their respective detection ranges P in front of the right burner 5 and the left burner 6 with almost no gap, and can secure a wide detection range as a whole.

Further, the optical sensors 4A arranged at the right end and the optical sensors 4I arranged at the left end in the arrangement of the optical sensors 4A to 4I have different arrangement directions. The optical sensors 4A arranged at the right end of the array are arranged with a directional component whose arrangement direction is toward the right, based on the first characteristic. Therefore, in the arrangement of the optical sensors 4A to 4I, a wider detection range P can be secured on the right side of the optical sensor 4A as compared with the case where the optical sensors 4A are arranged with the arrangement direction facing left. The optical sensors 4I arranged at the left end of the array are arranged with a directional component whose arrangement direction is toward the left, based on the first characteristic. Therefore, in the arrangement of the optical sensors 4A to 4I, a wider detection range P can be secured on the left side of the optical sensor 4I as compared with the case where the optical sensors 4I are arranged so as to be arranged to the right.

The controller 1 of the present embodiment has a foreign matter detection range P by the optical sensor 40 when controlling to reduce the gas flow rate, when the foreign matter is located straight in front of the light emitting element 41 in the emission direction, for example, at a distance of 10 cm. The measured voltage value of the detection signal is set to a threshold value (hereinafter, referred to as “operating voltage value”). As a result, when a foreign matter enters the detection range P of the shape shown in FIG. 7, the distance to the foreign matter corresponds to a distance of 10 cm or less. When a foreign matter has entered the detection range P, the stove 1 can detect that the foreign matter is located 10 cm or less above the optical sensor 40, that is, the foreign matter has approached the right burner 5 or the left burner 6.

As described above, the optical sensor 40 is arranged under the top plate 3 of the stove 1. In the present embodiment, when the foreign matter is located above the optical sensor 40, the distance between the upper surface of the top plate 3 and the foreign matter in the vertical direction is defined as "height" with reference to the upper surface of the top plate 3. .. In the following description, the height of the foreign matter corresponding to the measured voltage value output when the optical sensor 40 detects the foreign matter is referred to as “measured height”.

In the following description, the height of the foreign matter that is the reference for the CPU 71 to perform the process of weakening the thermal power of the right burner 5 or the left burner 6 is referred to as "operating height", and the range from the upper surface of the top plate 3 to the operating height is defined as the operating height. It is called "operating range". The CPU 71 of the stove 1 shows a height within a predetermined operating range based on the measured voltage value output by the optical sensor 40, and then a predetermined amount of change in the measured height within a predetermined stable operating width. When the operation stabilization time has elapsed, it is considered that a foreign object has approached the right burner 5 or the left burner 6. When the CPU 71 considers that a foreign object has approached the right burner 5 or the left burner 6, the CPU 71 reduces the thermal power of the right burner 5 or the left burner 6, so that the gas flow rate flowing through the thermal power adjusting mechanism 30 of the right burner 5 or the left burner 6 is reduced. Perform the processing to reduce. In the present embodiment, the operating heights (operating ranges) of the optical sensors 4A to 4K are set to different heights (different ranges) according to the respective arrangement positions.

When the foreign matter is at a height relatively distant from the optical sensor 40 in front of the light emitting element 41 of the optical sensor 40 in the emission direction, the foreign matter is at a height relatively close to the optical sensor 40. The intensity of the reflected light of the foreign matter incident on the light receiving element 44 is reduced. Therefore, as the distance from the optical sensor 40 to the foreign matter increases, the error that occurs between the actual height to the foreign matter and the measured height may increase. Therefore, in the present embodiment, the operating stable width of the optical sensors 4A to 4K is preset according to the magnitude of the operating height.

When a plurality of optical sensors 40 are provided, the optical sensor 40 may receive the reflected light reflected by the foreign matter from the infrared light emitted by the other optical sensors 40 arranged close to each other. In this case, noise may occur in the measured voltage value indicated by the detection signal output by the optical sensor 40. Further, the measured voltage value of the optical sensor 40 may be noisy due to fluctuations in the detection signal output by the optical sensor 40, voltage changes in the sensor input circuit 87, control circuit 70, etc. due to electrostatic surge or the like. May occur. The measured voltage value due to such noise often shows an unstable peak value in a relatively short time. Therefore, the stove 1 is provided with an operation stabilization time, and when the measurement height based on the measured voltage value exceeds the operation stabilization time and shows a stable height within the operation stability width, the stove 1 is moved to the right burner 5 or the left burner 6. It is considered that a foreign object has approached. As a result, it is possible to prevent the stove 1 from being controlled to reduce the gas flow rate in response to erroneous detection of foreign matter due to noise or the like.

The longer the operation stabilization time, the longer it takes for the stove 1 to consider that the foreign matter has approached the right burner 5 or the left burner 6. Setting an operation stabilization time that is too long is a factor that hinders the stove 1 from rapidly controlling the gas flow rate. In the stove 1, it has been clarified in advance experiments that the flame of the right burner 5 or the left burner 6 is more likely to ignite the detected foreign matter when the operation stabilization time is 0.5 seconds or more. Therefore, in the stove 1, the operation stabilization time of 0.4 seconds or less is preset in order to ensure safety.

After controlling the gas flow rate to be reduced, the stove 1 confirms that there is no foreign matter approaching the right burner 5 or the left burner 6, and then returns the gas flow rate to the original flow rate before the reduction. Do. In the following description, the height of the foreign matter that is the reference for the CPU 71 to perform the process of returning the thermal power of the right burner 5 or the left burner 6 is referred to as "release height", and the range from the upper surface of the top plate 3 to the release height is defined as the release height. It is called "non-release range". In the present embodiment, after the measurement height corresponding to any of the optical sensors 4A to 4E and 4J indicates the height within the operation range, the operation stabilization time elapses at the measurement height within the operation stability width. In this case, it is determined that a foreign object has approached the right burner 5. Further, after the measurement height corresponding to any of the optical sensors 4E to 4I and 4K corresponding to the left burner 6 indicates the height within the operation range, the operation stabilization time is determined by the measurement height within the operation stability width. After that, it is considered that the measured height is stable within the operating range, and it is determined that a foreign object has approached the left burner 6. On the other hand, when the predetermined release confirmation time elapses while the measurement heights corresponding to all of the optical sensors 4A to 4E and 4J corresponding to the right burner 5 indicate a height equal to or higher than the predetermined release height. , It is determined that there are no foreign objects approaching the right burner 5. Similarly, when the predetermined release confirmation time elapses with the measurement heights corresponding to all of the optical sensors 4E to 4I and 4K corresponding to the left burner 6 indicating a height equal to or higher than the predetermined release height. In addition, the measurement height is considered to be stable outside the non-release range, and it is determined that there is no foreign matter approaching the left burner 6. As described above, the stove 1 imposes stricter conditions when canceling the detection of the foreign matter than when detecting the foreign matter, thereby reducing the possibility that the flame of the burner ignites the foreign matter. In the present embodiment, the release heights (non-release ranges) of the optical sensors 4A to 4K are set to different heights (different ranges) according to the respective arrangement positions.

The setting value table will be described with reference to FIG. The set value table stores the target burner, the operating height, the operating stable width, the operating stable time, the release height, and the release confirmation time in association with each of the optical sensors 4A to 4K according to the control gas flow rate. The target burner indicates whether each of the optical sensors 4A to 4K is used to control the gas flow rate supplied to the right burner 5 or the left burner 6, and "right" is used for the right burner 5 and "left". Corresponds to the left burner 6. The optical sensors 4A to 4E and 4J use the right burner 5 as the target burner. The optical sensors 4E to 4I and 4K use the left burner 6 as the target burner. The set value table includes a table in which the control gas flow rate is the "third flow rate" and a table in which the control gas flow rate is the "second flow rate".

The table in which the control gas flow rate is the "third flow rate" is used when the gas flow rate is controlled to be reduced from the first flow rate or the second flow rate to the third flow rate, and when the gas flow rate is controlled to the third flow rate. Define the corresponding separation height, operation stabilization width, operation stabilization time, release height, and release confirmation time. The table in which the control gas flow rate is the "second flow rate" corresponds to the case where the gas flow rate is controlled to be reduced from the first flow rate to the second flow rate and the gas flow rate is controlled to the second flow rate. The operation stabilization width, operation stabilization time, release height, and release confirmation time are defined. The operating height, operating stable width, operating stable time, release height, and release confirmation time corresponding to the table in which the control gas flow rate is the "third flow rate" are set as the first operating height and the first operating stable width, respectively. The first operation stabilization time, the first release height, and the first release confirmation time. The operating height, operating stable width, operating stable time, release height, and release confirmation time corresponding to the table in which the control gas flow rate is the "second flow rate" are set as the second operating height and the second operating stable width, respectively. The second operation stabilization time, the second release height, and the second release confirmation time.

In the table where the control gas flow rate is the "third flow rate", the first operating height of the optical sensors 4A, 4C to 4G, 4I to 4K is "120" mm, and the first operating height of the optical sensors 4B, 4H is "120" mm. It is defined as 70 "mm, respectively. In the stove 1, it was clarified in advance experiments that if a foreign substance approaches a position within about 100 mm from the right burner 5 or the left burner 6 on which a medium-heat flame is formed, the possibility of the flame igniting the foreign substance increases. It has become. On the other hand, when the user cooks with the right burner 5 or the left burner 6, the handle of a one-handed pan such as a frying pan is likely to be arranged above the optical sensors 4B and 4H at a position of about 100 mm from the optical sensors 4B and 4H. In consideration of this, the stove 1 illuminates 70 mm, which is smaller than the distance between the handle of the pot and the optical sensors 4B and 4H when a general one-handed pot is placed on the trivets 7 and 8. It is set as the first operating height of the sensors 4B and 4H. Further, for the stove 1, the first operating height of 120 mm is set for the other optical sensors 40, which are less likely to have the handle of the pot than the optical sensors 4B and 4H, in order to ensure safety. There is. As described above, the set value table defines the first operating height suitable for the arrangement of the optical sensors 4A to 4K on the stove 1. By controlling the gas flow rate to be reduced based on the set value table, the stove 1 can avoid the execution of unnecessary gas flow rate reduction control and improve the usability of the stove 1.

The table in which the control gas flow rate is the "third flow rate" sets the first release height of the optical sensors 4A, 4C to 4G, 4I to 4K to "140" mm or more, and the first release height of the optical sensors 4B, 4H. It is defined as "90" mm or more. The stove 1 is 90 mm larger than the distance between the handle of the pot and the optical sensors 4B and 4H when a general one-handed pan is placed on the trivets 7 and 8, and the first of the optical sensors 4B and 4H. It is set as the release height. Further, by returning the gas flow rate from the third flow rate to the second flow rate or more, even if a flame of medium heat or more is formed in the right burner 5 or the left burner 6, a sufficient distance is secured so that foreign matter is not ignited. , 4C to 4G, 4I to 4K, the first release height is set to 140 mm. The release height of the stove 1 corresponding to the optical sensor 40 is set to be larger than the operating height corresponding to the optical sensor 40. As a result, the stove 1 can restore the gas flow rate when the foreign matter moves away from the optical sensor 40 by a release height that is farther than the operating height. The stove 1 ensures safety when the gas flow rate is returned to the flow rate before the foreign matter detection by setting the foreign matter detection release condition more severely than the foreign matter detection condition.

In the table where the control gas flow rate is the "second flow rate", among the optical sensors 4A to 4E and 4J whose target burners are "right", the second operating height and the second operating height of the optical sensors 40 other than the optical sensors 4B and 4J. (2) The operating stability width, the second operating stabilization time, the second release height, and the second release confirmation time are defined. The stove 1 sets the second operating height and the second release height to be larger than the first operating height and the first release height corresponding to the same optical sensor 40. When a high-heat flame is formed on the right burner 5 by the gas flow rate of the first flow rate, it is at the same position from the right burner 5 as compared with the case where a medium-heat flame is formed by the gas flow rate of the second flow rate. There is a high possibility that foreign matter will ignite. Therefore, the table in which the control gas flow rate is the "second flow rate" has a second operating height that is larger than the first operating height and the first release height as the operating height corresponding to the thermal power of the flame formed on the right burner 5. The operating height and the second release height are defined.

For example, when a two-handed pan is placed on the trivet 7, the two handles of the two-handed pan are likely to extend in the left-right direction of the pan. The left arm of the user who tries to grab the handle on the left side of this two-handed pan is inserted diagonally forward to the left of the right burner 5 from the position between the right burner 5 and the left burner 6, so the tip of the left arm is on the right. Very easy to get close to the burner 5. The stove 1 sets the second operating height, the second operating stable width, the second operating stable time, the second release height, and the second release confirmation time for the optical sensor 4J arranged diagonally to the left of the right burner 5. Do not define. Items marked with "-" in the design value table indicate that there is no definition of the set value. Therefore, the stove 1 is a gas based on the first operating height, the first operating stable width, the first operating stable time, the first release height, and the first release confirmed time with respect to the height measured by the optical sensor 4J. Control the flow rate. As a result, the stove 1 can set the gas flow rate to the third flow rate at a time when a foreign matter approaches the right burner 5 from the diagonally left front while the gas flow rate is the first flow rate or the second flow rate. Therefore, ignition of foreign matter approaching the right burner 5 from diagonally forward left is effectively prevented. The stove 1 has a second operating height for the same reason as for the optical sensor 4B and for avoiding unnecessary gas flow control by erroneously detecting the handle of the one-handed pan as a foreign substance. , Second operation stabilization width, second operation stabilization time, second release height, second release confirmation time are not defined.

In the table where the control gas flow rate is the "second flow rate", the second operation stabilization time of the optical sensors 4A, 4C, and 4D is "0.2" seconds, and the second operation stabilization time of the optical sensor 4E is "0. It is defined as 4 "seconds. The optical sensors 4A, 4C, and 4D are arranged at positions closer to the right burner 5 than the optical sensor 4E. Therefore, the possibility that the flame of the right burner 5 ignites the foreign matter that approaches the positions of the optical sensors 4A, 4C, and 4D depends on the possibility that the flame of the right burner 5 ignites the foreign matter that approaches the position of the optical sensor 4E. Is expected to be higher. On the other hand, since the optical sensor 4E is arranged at a position between the right burner 5 and the left burner 6 in the central front portion of the stove 1, foreign matter frequently approaches the position of the optical sensor 4E when the stove 1 is used. It is expected to be done. Based on such an arrangement of the optical sensor 40, the stove 1 defines the second operation stabilization time of the optical sensors 4A, 4C, and 4D to be shorter than the second operation stabilization time of the optical sensor 4E, and the stove 1 defines the second operation stabilization time. The safety is guaranteed. Further, the stove 1 defines a second operation stabilization time longer than that of the optical sensors 4A, 4C, and 4D for the optical sensor 4E, thereby reducing unnecessary gas flow rate reduction control. In this way, since the second operation stabilization time is defined according to the arrangement of the optical sensor 40, the stove 1 can improve the usability of the stove 1 while ensuring the safety against the approach of foreign matter.

The table in which the control gas flow rate is the "second flow rate" makes the second operating height (170 mm) of the optical sensors 4D and 4E larger than the second operating height (150 mm) of the optical sensors 4A and 4C. It is defined. Since the optical sensors 4D and 4E are arranged closer to the center of the stove 1 than the optical sensors 4A and 4C, the optical sensors 4D and 4E are directed diagonally forward to the left of the right burner 5 from the position between the right burner 5 and the left burner 6. Can detect foreign matter inserted. As described above, the foreign matter inserted in this way is more easily approached to the right burner 5 than the foreign matter inserted toward the right burner 5 from another position. Therefore, the stove 1 controls the condition for reducing the gas flow rate with respect to the measured heights of the optical sensors 4D and 4E, and controls for reducing the gas flow rate with respect to the measured heights of the optical sensors 4A and 4C. Set stricter than the conditions. As a result, the stove 1 can effectively prevent ignition of foreign matter approaching the right burner 5. Further, the stove 1 defines the second release height (190 or more) of the optical sensors 4D and 4E as a distance larger than the second release height (170 or more) of the optical sensors 4A and 4C. As a result, the stove 1 can restore the gas flow rate when the foreign matter is sufficiently far from the position where the foreign matter easily approaches the right burner 5. In this way, the stove 1 is safe when the gas flow rate is returned to the flow rate before the foreign matter detection by strictly setting the release condition of the foreign matter detection according to the arrangement of the optical sensor 40 with respect to the right burner 5 and the left burner 6. Is secured.

In the set value table, the first operating stability width is defined as "± 10" mm and the second operating stability width is defined as "± 30" mm, which are different values. As described above, as a characteristic of the optical sensor 40, the larger the distance from the optical sensor 40 to the foreign matter, the larger the error that occurs between the actual distance from the optical sensor 40 to the foreign matter and the distance indicated by the measured voltage value. May become. As a result, the fluctuation width generated in the measured voltage value output by the optical sensor 40 may increase as the distance from the optical sensor 40 to the foreign matter increases. Therefore, the stove 1 is provided with a second operating stability width associated with a second operating height set to a height larger than the first operating height in a range wider than the first operating stable width. As a result, the stove 1 can smoothly control the gas flow rate according to the operating height.

The specific setting value table will be described with reference to FIG. The specific set value table includes a table in which the control gas flow rate is the "third flow rate", similar to the set value table. When a specific mode described later is set, foreign matter is less likely to approach the right burner 5 or the left burner 6 than when other mode types of cooking modes are set. Therefore, when the specific mode is set, the stove 1 controls the reduction of the gas flow rate from the first flow rate or the second flow rate to the third flow rate, and changes the gas flow rate from the first flow rate to the third flow rate. The reduction control to two flow rates is omitted. Therefore, the specific set value table does not include a table corresponding to the table in which the control gas flow rate in the set value table is the "second flow rate". Therefore, when the gas flow rate is controlled according to the specific set value table, the stove 1 changes the gas flow rate at once when a foreign matter approaches the right burner 5 or the left burner 6 while the gas flow rate is the first flow rate or the second flow rate. It can be a third flow rate.

The cooking mode table will be described with reference to FIG. The stove 1 is provided with a cooking mode in advance according to the cooking content. The stove 1 in which the cooking mode is set automatically controls the heating power according to the cooking content. The cooking mode table stores the mode type and the control pattern in association with each other. The mode type indicates the type of cooking mode. In this embodiment, mode types of "rice cooking mode", "boiler mode", "high temperature stir-fry mode", and "temperature control mode" are provided. The control pattern shows a pattern of thermal power control according to the mode type. In pattern P1, which is the control pattern of the "rice cooking mode", the right burner 5 or the left burner 6 has medium heat and low heat until the rice cooking is completed with the pot placed on either of the trivets 7 and 8. It is a pattern in which the force is repeated alternately and the fire is automatically extinguished when the rice cooking is completed. In pattern P2, which is the control pattern of the "boiling mode", the right burner 5 or the left burner 6 keeps high or medium heat while the kettle or the like is placed on either of the trivets 7 and 8, and the kettle water boils. Then, the fire is automatically extinguished. The pattern P3, which is a control pattern of the “high temperature stir-fry mode”, is a pattern suitable for cooking stir-fried foods, in which the right burner 5 or the left burner 6 mainly keeps high heat to keep the pot bottom temperature high. The pattern P4, which is the control pattern of the "temperature control mode", is mainly used for cooking fried foods, and is a pattern that automatically controls the heating power so as to keep the temperature of the oil or the like in the pan constant. The user can set a desired cooking mode on the stove 1 by inputting a predetermined operation input to the operation panel 25 at the start of using the stove 1.

Of these cooking modes, in the "rice cooking mode" and the "boiler mode", the user has the right burner 5 or the left until the rice cooking or boiling is completed with the pot or the like placed on the trivets 7 and 8. There is no need to adjust the heat of the burner 6 or mix the food to be cooked with chopsticks. Therefore, when these modes are set, it is unlikely that a foreign object approaches the right burner 5 or the left burner 6. Therefore, the stove 1 provides a specific set value table that defines a set of set values for the case where the "rice cooking mode" and the "boiler mode" are set, separately from the set value table, and provides the "rice cooking mode" and "rice cooking mode" and " When the "boiler mode" is set, the gas flow rate is controlled based on the specific set value table. As a result, the stove 1 can perform thermal power reduction control suitable for the cooking mode. Hereinafter, the "rice cooking mode" and the "boiler mode" will be referred to as a "specific mode".

When the CPU 71 of the stove executes the gas flow rate control process (see FIGS. 12 and 13) and determines that the foreign matter has approached the right burner 5 or the left burner 6 based on the detection result of the foreign matter by the optical sensor 40, the right A process of weakening the thermal power of the burner 5 or the left burner 6 is performed. Further, when the CPU 71 determines that the foreign matter is no longer approaching based on the detection result by the optical sensor 40 after weakening the thermal power of the right burner 5 or the left burner 6, the thermal power of the right burner 5 or the left burner 6 with the reduced thermal power is determined. Performs the process of restoring. When the user cooks with the right burner 5, a cooking container such as a pot is placed on the trivet 7 and the ignition button 15 is pressed. The safety valve 64 of the thermal power control mechanism 60 is in a mechanically closed state when the ignition button 15 is not pressed. Further, the solenoid valves 61 to 63 are maintained on the open side when the ignition button 15 is not pressed. When the ignition button 15 is pressed, it opens in conjunction with it, and the first flow rate of gas flows through the thermal power adjusting mechanism 30. The CPU 71 drives the igniter 35 and ignites the right burner 5. The firepower of the right burner 5 becomes a high firepower.

The CPU 71 reads and executes various programs including the gas flow rate control process from the ROM 72 in response to the ignition of the right burner 5. The flame formed in the flame hole of the right burner 5 is detected by the thermocouple 5C. The user manually operates the heating power adjusting lever 18 to adjust the heating power of the right burner 5 according to the degree of baking of the object to be cooked, the progress of cooking, and the like. When the right burner 5 is ignited, the user can perform a predetermined operation input for setting a desired cooking mode on the operation panel 25. When the cooking mode is set, the CPU 71 adjusts the heating power according to the cooking mode. Similarly, when the user cooks with the left burner 6, the CPU 71 opens the safety valves 64 and the solenoid valves 61 and 63 of the thermal power control mechanism 60 when the ignition button 17 is pressed, and causes the thermal power adjustment mechanism 30 to open the cooking. Flow one flow rate of gas. The CPU 71 reads and executes various programs including the gas flow rate control process from the ROM 72 in response to the ignition of the left burner 6.

As shown in FIG. 12, when the gas flow rate control process is started, the CPU 71 determines whether any mode type of cooking mode is received via the operation panel 25 (S1). When the CPU 71 has not received the cooking mode (S1: NO), the CPU 71 shifts the process to S3. When the cooking mode is received (S1: YES), the CPU 71 stores the received mode type in the RAM 73 and sets the cooking mode of the received mode type (S2). The CPU 71 shifts the processing to S3.

The CPU 71 acquires the gas flow rates flowing through the thermal power adjusting mechanisms 30 of the right burner 5 and the left burner 6 based on the open status of the solenoid valves 61 and 62 (S3). The CPU 71 stores the acquired gas flow rate (that is, whether any or any of the solenoid valves 61 and 62 is open) in the RAM 73.

The CPU 71 determines whether or not the specific mode is set (S4). In this process, if a predetermined mode type is stored in the RAM 73 in the process of S1, the CPU 71 refers to the stored mode type and determines whether the mode type indicates a specific mode (“rice cooking mode” or “boiler”). Whether to indicate "mode") is determined. When the mode type stored in the RAM 73 indicates a specific mode (S4: YES), the CPU 71 refers to the specific setting value table (S6). On the other hand, when the cooking mode is not set or the set cooking mode is not the specific mode (S4: NO), the CPU 71 refers to the set value table (S5).

The CPU 71 acquires the measured voltage values indicated by the detection signals of the optical sensors 4A to 4K, respectively (S7). The CPU 71 calculates the measurement height corresponding to each of the optical sensors 4A to 4K based on the acquired measured voltage value. The CPU 71 compares each of the calculated measured heights with the operating height indicated by the design value table or the specific set value table referred to in the processing of S5 or S6.

The CPU 71 determines whether or not there is an optical sensor 40 whose measured height indicates a height within the operating range (S8). At this time, in the CPU 71, when the gas flow rate acquired in the process of S3 is the first flow rate and the set value table is referred to, the optical sensor 40 indicating that the measured height is equal to or less than the first operating height. First determine if there is one. The CPU 71 determines whether there is an optical sensor 40 whose measured height is within the second operating height when there is no optical sensor 40 whose measured height is equal to or less than the first operating height. .. The CPU 71 has an optical sensor 40 whose measured height is equal to or less than the first operating height when the gas flow rate acquired in the process of S3 is the second flow rate and the set value table is referred to. Determine if there is. When referring to the specific set value table, the CPU 71 determines whether or not there is an optical sensor 40 whose measured height is equal to or less than the first operating height. Based on these determinations, the CPU 71 determines whether or not there is at least one optical sensor 40 indicating the measurement height within the first operating range or the second operating range. The CPU 71 returns the process to S1 when there is no optical sensor 40 whose measured height is equal to or lower than the operating height (S8: NO). In this case, the thermal power of the right burner 5 and the left burner 6 is maintained at the thermal power at the time of S3. Although not shown, the CPU 71 may repeat the processes of S1 to S3 without performing the processes of S4 to S16 when the gas flow rate acquired in the process of S3 is the third flow rate.

When there is at least one optical sensor 40 whose measured height indicates a height within the operating range (S8: YES), the CPU 71 identifies the optical sensor 40 whose measured height indicates a height within the operating range (S9). ). The CPU 71 stores information indicating the specified optical sensor 40 in the RAM 73. The optical sensor 40 specified by the process of S9 is hereinafter referred to as a "specific sensor".

The CPU 71 determines whether the first elapsed time at which the measurement is started in the process of S25 described later is being measured (S10). The first elapsed time indicates the time elapsed from the cancellation of the detection of foreign matter in the gas flow rate control process to the next detection of foreign matter. The CPU 71 measures the first elapsed time using a timer (not shown) included in the control circuit 70. When the determination process of S13 is executed for the first time after the start of execution of the gas flow rate control process and the first elapsed time is not being measured (S10: NO), the CPU 71 shifts the process to S15.

When the stove 1 is used for cooking, for example, the user of the stove 1 repeatedly stirs the contents of the cooking container placed on the trivets 7 and 8 with chopsticks or the like. There is. For example, it is assumed that the detection range P shown in FIG. 8B corresponds to an operating range of 12 cm. In this case, the arm or the like of the user who uses the right burner 5 may be placed at various positions in the region R shown in FIG. 8B while moving. Even if the user's arm or the like actually has a sufficient height separated from the top plate 3 by 12 cm or more, if it is in the region of the region R that overlaps the detection range P, the optical sensors 4A to 4D, Based on the measured height based on any of 4J, it is determined that the user's arm or the like is at a height within the operating range. In such a case, the operation of stirring the contents of the cooking container by the user tends to cause frequent repetition of reduction and restoration of the gas flow rate. At this time, it becomes difficult for the thermal power of the right burner 5 or the left burner 6 to be maintained at the thermal power desired by the user. In order to avoid such a problem, the stove 1 is gas when the first elapsed time from the end of the previous detection of foreign matter to the next detection of foreign matter is less than a predetermined time. It is intended to limit the execution of control that reduces the flow rate. As a result, the stove 1 can avoid unnecessary repetition of reduction and restoration of the gas flow rate according to the operation related to cooking by the user. As a result, the stove 1 can control the heating power according to the actual cooking operation of the user, so that the usability of the stove 1 is improved. In the present embodiment, the control to reduce the gas flow rate is performed when the first elapsed time is 5 seconds or more based on the result of the prior experiment. The criterion of "5 seconds" is an example, and may be arbitrarily determined according to the arrangement, number, safety assurance criteria, and the like of the optical sensors 40 on the stove 1.

When the first elapsed time is being measured (S10: YES), the CPU 71 determines whether the first elapsed time during measurement indicates 5 seconds or more (S11). When the first elapsed time is 5 seconds or more (S11: YES), the CPU 71 ends the measurement of the first elapsed time (S12), and clears the timer value. The CPU 71 shifts the processing to S15.

When the first elapsed time is less than 5 seconds (S11: NO), the CPU 71 sets the operation stabilization time associated with the specific sensor in the set value table and the specific set value table to a predetermined "0.2". Change from "seconds" or "0.4" seconds to "0.5" seconds (S13). By changing the operation stabilization time to be longer than before, the CPU 71 has been changed to a region in which the arm or the like of the user during cooking overlaps the detection range P in the region R shown in FIG. 8 (B). If it is left in a time shorter than the operation stabilization time, it becomes difficult to consider that a foreign object has approached the right burner 5 or the left burner 6. In this way, the CPU 71 changes the foreign matter detection conditions such as the operation stabilization time in the direction in which the reduction control of the gas flow rate is restricted when the first elapsed time is less than the predetermined time, so that the unnecessary gas flow rate is used. It is possible to avoid repeating the reduction and recovery of.

Next, the CPU 71 starts measuring the second elapsed time using a timer (not shown) provided in the control circuit 70 (S14). The CPU 71 shifts the processing to S15. The second elapsed time is the time that elapses from the change of the operation stabilization time in the process of S13 to the next detection of foreign matter. When the second elapsed time exceeds a predetermined time, the CPU 71 returns the operation stabilization time changed in the process of S13 to the operation stabilization time predetermined for the specific sensor in the process of S28 described later.

The CPU 71 monitors the change in the measured voltage value indicated by the detection signal of the specific sensor during the operation stabilization time (S15). In this process, when the CPU 71 determines in the process of S8 that there is an optical sensor 40 whose measured height is within the first operating range, the measured voltage value during the first operation stable time corresponding to the specific sensor. Monitor changes in. When the CPU 71 determines in S8 that there is an optical sensor 40 whose measurement height is within the second operating range, the CPU 71 changes the measured voltage value of the specific sensor during the second operation stabilization time corresponding to the specific sensor. Monitor. The CPU 71 extracts the maximum value and the minimum value of the measurement height within the operation stabilization time. The width of the maximum value and the minimum value of the extracted measurement height corresponds to the amount of change in the measurement height within the operation stabilization time. When the operation stabilization time is changed in the process of S13, the CPU 71 monitors the amount of change in the measured height during the operation stabilization time changed in the process of S13.

The CPU 71 determines whether the amount of change in the measurement height of the specific sensor within the operation stabilization time is within the operation stability width corresponding to the specific sensor (S16). In this process, when the CPU 71 determines in S8 that the measured height is within the first operating range, it determines whether the amount of change in the measured height falls within the first operating stable width corresponding to the specific sensor. To do. When the CPU 71 determines in S8 that the measured height is within the second operating range, the CPU 71 determines whether the amount of change in the measured height falls within the second operating stable width corresponding to the specific sensor. When the amount of change in the measured height within the operation stabilization time exceeds the operation stability width corresponding to the specific sensor (S16: NO), the CPU 71 returns the process to S1.

The CPU 71 considers that the measured height is stable within the operating range when the amount of change in the measured height within the operating stable time falls within the operating stable width corresponding to the specific sensor (S16: YES). As shown in FIG. 13, the solenoid valve circuit 91 is instructed to reduce the gas flow rate (S17). In this process, when the CPU 71 determines S8 with reference to the table in which the control gas flow rate is the "third flow rate", the CPU 71 instructs the solenoid valve circuit 91 to set the gas flow rate to the third flow rate. Upon receiving the instruction to set the gas flow rate to the third flow rate, the solenoid valve circuit 91 closes the solenoid valves 61 and 62 to set the gas flow rate flowing through the thermal power adjusting mechanism 30 to the third flow rate. As a result, the thermal power of the right burner 5 or the left burner changes from high thermal power or medium thermal power to low thermal power. When the CPU 71 determines S8 with reference to the table in which the control gas flow rate is the "second flow rate", the CPU 71 instructs the solenoid valve circuit 91 to set the gas flow rate to the second flow rate. Upon receiving the instruction to set the gas flow rate to the second flow rate, the solenoid valve circuit 91 closes the solenoid valve 62 to set the gas flow rate flowing through the thermal power adjusting mechanism 30 to the second flow rate. As a result, the thermal power of the right burner 5 changes from high thermal power to medium thermal power.

The CPU 71 issues an instruction to the buzzer circuit 88, drives the piezoelectric buzzer 77, and notifies the detection of foreign matter (S18). Further, the CPU 71 lights a predetermined LED on the operation panel 25 to notify the detection of foreign matter. Thereby, the user can recognize that the stove 1 has detected the foreign matter and that the thermal power of the right burner 5 or the left burner has been reduced and controlled according to the detection of the foreign matter.

The CPU 71 acquires the measured voltage values indicated by the detection signals of the optical sensors 4A to 4K, respectively (S19). The CPU 71 identifies the target burner of the specific sensor. When the specific sensor is the optical sensors 4A to 4D, 4J, the CPU 71 identifies that the target burner is the right burner 5. When the specific sensor is the optical sensor 4F to 4I, 4K, the CPU 71 specifies that the target burner is the left burner 6. When the specific sensor is the optical sensor 4E, the CPU 71 uses the right burner 5 if gas is flowing through the thermal power adjusting mechanism 30 of the right burner 5, and the left burner if gas is flowing through the thermal power adjusting mechanism 30 of the left burner 6. Each of 6 is specified as a target burner. When gas is flowing through the thermal power adjusting mechanism 30 of both the right burner 5 and the left burner 6, the CPU 71 specifies the right burner 5 and the left burner 6 as target burners.

Does the CPU 71 indicate that all of the measured voltage values acquired in the process of S21 based on the measured voltage values of the optical sensor 40 corresponding to the specified target burner are higher than the respective release heights? Is determined (S20). At this time, in the CPU 71, when the gas flow rate acquired in the process of S3 is the first flow rate and the set value table is referred to, the optical sensor 40 indicating that the measured height is equal to or higher than the second release height. Determine if there is. The CPU 71 has an optical sensor 40 whose measurement height is equal to or higher than the first release height when the gas flow rate acquired in the process of S3 is the second flow rate and the set value table is referred to. To judge. When referring to the specific set value table, the CPU 71 determines whether or not there is an optical sensor 40 whose measured height is equal to or higher than the first release height. Based on these determinations, it is determined whether or not the measured heights of the plurality of optical sensors 40 including the specific sensor indicate a height equal to or higher than the first release height or the second release height.

When even one of the measurement heights based on the measurement voltage value of the optical sensor 40 corresponding to the specified target burner indicates a height less than the release height (S20: NO), the CPU 71 returns the process to S19. The gas flow rate flowing through the thermal power adjusting mechanism 30 of the target burner is maintained at the flow rate reduced by the processing of S17. The thermal power of the target burner is maintained at the reduced thermal power due to the processing of S17.

When all the measured heights based on the measured voltage values of the optical sensor 40 corresponding to the specified target burner indicate a height equal to or higher than the release height (S20: YES), the CPU 71 of the optical sensor 40 corresponding to the target burner. The change in the measured voltage value shown is monitored during the release confirmation time (S21). In this process, when the CPU 71 determines in the process of S20 that the measured height indicates a distance equal to or greater than the first release height, the CPU 71 monitors the change in the measured voltage value during the first release confirmation time. When the CPU 71 determines in the process of S20 that the measured height indicates a distance equal to or greater than the second release height, the CPU 71 monitors the change in the measured voltage value during the second release confirmation time. In the present embodiment, both the first release confirmation time and the second release confirmation time are "1.0" seconds. For example, the first cancellation confirmation time and the second cancellation confirmation time may be set to different times, such as making the first cancellation confirmation time longer than the second cancellation time.

The CPU 71 determines whether or not the release confirmation time elapses by maintaining the measurement height based on the measured voltage value to be monitored at a height equal to or higher than the release height (S22). When the measurement height based on the measured voltage value to be monitored does not maintain a height equal to or higher than the release height during the release confirmation time (S22: NO), the CPU 71 returns the process to S19. The CPU 71 indicates that all the measured heights based on the measured voltage values of the optical sensor 40 corresponding to the target burner are higher than the released height (S20: YES), and the measured height is higher than the released height. The process of S20 to S22 is repeated until the release confirmation time elapses (S22: YES).

The CPU 71 instructs the solenoid valve circuit 91 to restore the gas flow rate when the measurement height based on the measured voltage value to be monitored is maintained at a height equal to or higher than the release height and the release confirmation time has elapsed (S22: YES). (S23). In this process, the CPU 71 gives an instruction to the solenoid valve circuit 91 based on the opening status of the solenoid valves 61 and 62 stored in the RAM 73 in accordance with the process of S3. When the memory of the opening status of the solenoid valves 61 and 62 indicates that the solenoid valve 61 is open and the solenoid valve 62 is closed, the CPU 71 opens the solenoid valve 61 to the solenoid valve circuit 91 to increase the gas flow rate. Instruct to set the second flow rate. Upon receiving the instruction, the solenoid valve circuit 91 opens the solenoid valve 61 to change the gas flow rate flowing through the thermal power adjusting mechanism 30 from the third flow rate to the second flow rate. As a result, the thermal power of the right burner 5 or the left burner returns from low thermal power to medium low thermal power. When the memory of the opening status of the solenoid valves 61 and 62 indicates that both the solenoid valves 61 and 62 are open, the CPU 71 opens both the solenoid valves 61 and 62 to the solenoid valve circuit 91 to increase the gas flow rate. Instruct to set the first flow rate. Upon receiving the instruction, the solenoid valve circuit 91 opens both the solenoid valves 61 and 62 to change the gas flow rate flowing through the thermal power adjusting mechanism 30 from the second flow rate or the third flow rate to the first flow rate. As a result, the thermal power of the right burner 5 or the left burner returns from the medium thermal power or the low thermal power to the high thermal power.

The CPU 71 issues an instruction to the buzzer circuit 88, stops driving the piezoelectric buzzer 77, and cancels the notification of foreign matter detection (S24). Further, the CPU 71 turns off a predetermined LED on the operation panel 25 to cancel the notification of foreign matter detection. As a result, the user can recognize that the stove 1 has finished detecting the foreign matter and that the thermal power of the right burner 5 or the left burner has been restored according to the completion of the detection of the foreign matter. The CPU 71 starts the measurement of the first elapsed time described above by using the timer (not shown) provided in the control circuit 70 (S25).

Next, the CPU 71 determines whether the second elapsed time at which the measurement is started by the process of S14 described above is being measured (S26). When the second elapsed time is not being measured (S26: NO), the CPU 71 returns the process to S1 (see FIG. 12). When the second elapsed time is being measured (S26: YES), the CPU 71 determines whether the second elapsed time being measured indicates a predetermined time (5 seconds in the present embodiment) or more (S27). When the second elapsed time is less than 5 seconds (S27: NO), the CPU 71 returns the process to S1. The predetermined time of 5 seconds is an example, and any time may be set as the predetermined time.

When the second elapsed time is 5 seconds or more (S27: YES), the CPU 71 makes a change to return the operation stabilization time changed in the process of S13 to the operation stability time predetermined for the specific sensor (S28). ). As a result, the operation stabilization time associated with the specific sensor is restored to the original operation stabilization time, so that the safety of the stove 1 is maintained. After that, the CPU 71 ends the measurement of the second elapsed time (S29), and clears the value of the timer. The CPU 71 returns the process to S1.

When the gas flow rate control process is performed as described above, for example, when the user places the pot on the trivets 7 and 8, the handle extends to a position indicating the operating range defined in the set value table. Sometimes you want to use a special pot. Further, the user may wish to further improve the safety of the stove 1 by changing the flame of the right burner 5 or the left burner 6 so that the flame of the right burner 5 or the left burner 6 is extinguished when the stove 1 detects a foreign substance. In addition, the user may wish to further improve the safety of the stove 1 by changing the conditions for the stove 1 to detect foreign matter such as the operating height and the operating stable time to stricter conditions. .. Further, since the height of the user, the purpose of use of the stove 1, etc. are various, it is assumed that there is a desire to change the operating height, etc. according to the preference of the user. The CPU 71 executes a design value change process (see FIG. 14), and changes various setting values defined in the setting value table and the specific setting value table within a range in which safety can be guaranteed, according to the user's request. Perform processing. When the CPU 71 receives a predetermined operation input for changing the set value defined in the set value table and the specific set value table via the operation panel 25 in the state where the solenoid valves 61 to 63 are closed, the CPU 71 receives from the ROM 72. Read and execute various programs including design value change processing.

As shown in FIG. 14, when the design value change process is started, the CPU 71 specifies which optical sensor 40 the set value is to be changed (S31). At this time, the user performs an operation input for selecting one of the optical sensors 40 by using the buttons on the operation panel 25. The CPU 71 identifies any optical sensor 40 according to the operation input content.

The CPU 71 determines whether or not the detection invalidation change instruction has been received (S32). The detection invalidation change instruction is an instruction for not performing the gas flow rate control process according to the measured voltage value indicated by the detection signal output by the optical sensor 40 specified in the process of S31. When the CPU 71 has not received the detection invalidation change instruction (S32: NO), the CPU 71 shifts the process to S36.

When the CPU 71 receives the detection invalidation change instruction (S32: YES), the CPU 71 determines whether the optical sensor 40 specified in the process of S31 is any of the optical sensors 4D, 4F, 4J, and 4K (S33). When the optical sensor 40 is any of the optical sensors 4D, 4F, 4J, and 4K (S33: YES), the CPU 71 shifts the process to S36. As described above, among the optical sensors 40, the optical sensors 4D, 4F, 4J, and 4K are arranged at positions where foreign matter can be easily approached as compared with other optical sensors 40. It is not preferable to disable the foreign matter detection by the optical sensors 4D, 4F, 4J, and 4K from the viewpoint of ensuring the safety of the stove 1. Therefore, the CPU 71 does not allow the detection invalidation change for the optical sensors 4D, 4F, 4J, and 4K.

When the optical sensor 40 is an optical sensor 40 other than the optical sensors 4D, 4F, 4J, and 4K (S33: NO), the CPU 71 sets the set value associated with the corresponding optical sensor 40 in the set value table to "-(. By changing to "(no definition)", the detection invalidation change is registered (S35). For example, when cooking using the special pot described above, foreign matter is not detected by the predetermined optical sensor 40, so that unnecessary gas flow rate reduction control is not performed. By providing the processes of S32, S33, and S35 in the design value change process, it is possible to provide the user with an easy-to-use stove 1 according to the actual usage mode. The CPU 71 shifts the process to S36.

When the stove 1 detects a foreign substance, the CPU 71 determines whether or not it has received an instruction to change the flame of the right burner 5 or the left burner 6 so as to extinguish the fire (S36). When the stove 1 detects a foreign substance, the CPU 71 shifts the process to S41 when it has not received an instruction to change the flame of the right burner 5 or the left burner 6 so as to extinguish the fire (S36: NO).

When the CPU 71 receives an instruction to change the flame of the right burner 5 or the left burner 6 to extinguish (S36: YES), the CPU 71 changes the item of the control gas flow rate in the set value table to "no gas flow rate". , Register to extinguish the flame of the right burner 5 or the left burner 6 (S38). In this process, the CPU 71 may change only the "third gas flow rate" among the items of the control gas flow rate to "no gas flow rate", or both the "third gas flow rate" and the "second gas flow rate". May be changed to "no gas flow rate". When the CPU 71 changes only the "third gas flow rate" to "no gas flow rate" among the control gas flow rate items, the CPU 71 sets the gas flow rate to the solenoid valve circuit 91 in the process of S18 in the gas flow rate control process described above. Instead of the instruction to set the flow rate, the solenoid valve circuit 91 is instructed to prevent gas from flowing to the thermal power adjusting mechanism 30. The solenoid valve circuit 91, which has received an instruction to prevent gas from flowing to the thermal power adjusting mechanism 30, closes the solenoid valves 61 to 63 to prevent gas from flowing to the thermal power adjusting mechanism 30. When both the "third gas flow rate" and the "second gas flow rate" of the control gas flow rate items are changed to "no gas flow rate", the CPU 71 sets the gas flow rate in the solenoid valve circuit 91 in the process of S18. The process of transmitting the instruction to set the flow rate to 2 is also changed to the process of giving the instruction to prevent the gas from flowing to the thermal power adjusting mechanism 30 to the solenoid valve circuit 91. In the design value change process, by providing the processes of S36 and S38, when the stove 1 detects a foreign substance, the user who wants to extinguish the flame of the right burner 5 or the left burner 6 to further improve the safety of the stove 1. Can meet the demands of. The CPU 71 shifts the process to S41.

The CPU 71 determines whether or not it has received an instruction to change the operating height (S41). When the CPU 71 has not received the instruction to change the operating height (S41: NO), the processing shifts to S51. When the CPU 71 receives the instruction to change the operating height (S41: YES), the CPU 71 acquires the operating height change candidate value input by the user via the operation panel 25 (S43).

The CPU 71 determines whether the acquired change candidate value is a value within a range in which the change is allowed (S43). In order to prevent the safety of the stove 1 from being impaired by the user changing the operating height, the stove 1 has a predetermined change allowable range in which the operating height can be changed. In the present embodiment, the CPU 71 acquires a candidate value indicating the operating height as a change candidate value. The change allowable range is set to ± 20 mm with respect to the operating height set in the set value table as the initial setting. In addition, in order to prevent the flame of the right burner 5 or the left burner 6 from being easily ignited by the foreign matter due to the change in the operating height, the change allowable range sets the lower limit of the changeable operating height to "70 mm". It is stipulated. In this process, the CPU 71 determines whether the acquired change candidate value is within the change allowable range with respect to the operating height defined by the set value table for the optical sensor 40 specified in the process of S31. This change allowable range may be arbitrarily provided according to the arrangement of the optical sensor 40 and the like.

When the acquired change candidate value is within the change allowable range (S43: YES), the CPU 71 changes the set value associated with the corresponding optical sensor 40 in the set value table to the change candidate value. Then, the new operating height is registered in the set value table (S45). The CPU 71 shifts the process to S51. When the acquired change candidate value is not within the change allowable range (S43: NO), the CPU 71 does not perform the process of S45 and shifts the process to S51. In the design value change process, by providing the processes of S41, S42, S43, and S45, the user is allowed to change the foreign matter detection condition of the stove 1 within the range in which the safety of the stove 1 is guaranteed. Usability can be improved.

The CPU 71 determines whether or not it has received an instruction to change the operation stabilization time (S51). When the CPU 71 has not received the instruction to change the operation stabilization time (S51: NO), the CPU 71 ends the design value change process. When the CPU 71 receives an instruction to change the operation stabilization time (S51: YES), the CPU 71 acquires a change candidate value of the operation stabilization time input by the user via the operation panel 25 (S52).

The CPU 71 determines whether the acquired change candidate value is a value within a range in which the change is allowed (S53). In order to prevent the safety of the stove 1 from being impaired by the user changing the stabilization time, the stove 1 has a predetermined change allowable range in which the stabilization time can be changed. In the present embodiment, the CPU 71 acquires a candidate value indicating the operation stabilization time as a change candidate value. The change allowable range is set to ± 0.2 seconds with respect to the operation stabilization time set in the set value table as the initial setting. In addition, in order to prevent the flame of the right burner 5 or the left burner 6 from being easily ignited by the foreign matter due to the change in the operation stabilization time, the change allowable range sets the upper limit of the changeable operating height to "0. 5 seconds ". In this process, the CPU 71 determines whether the acquired change candidate value is within the change allowable range with respect to the operation stabilization time defined in the set value table for the optical sensor 40 specified in the process of S31. This change allowable range may be arbitrarily provided according to the arrangement of the optical sensor 40 and the like.

When the acquired change candidate value is within the change allowable range (S53: YES), the CPU 71 changes the set value associated with the corresponding optical sensor 40 in the set value table to the change candidate value. Then, the new operation stabilization time is registered in the set value table (S55). After that, the CPU 71 ends the design value change process. If the acquired change candidate value is not within the change allowable range (S53: NO), the CPU 71 does not perform the process of S55 and ends the design value change process. In the design value change process, by providing the processes of S51, S52, S53, and S55, the user is allowed to change the foreign matter detection condition of the stove 1 within the range in which the safety of the stove 1 is guaranteed. Usability can be improved.

As described above, the stove 1 has an optical sensor 40 arranged outside the burner. The optical sensor 40 outputs a measured voltage value indicating the distance to the measurement target. The stove 1 can specify the measurement height based on the measured voltage value when a foreign substance such as clothes of the user of the stove 1 is close to the outside of the right burner 5 or the left burner 6. The CPU 71 determines whether or not there is at least one optical sensor 40 whose measured height indicates a distance within the operating range (S8). When there is an optical sensor 40 whose measurement height indicates a distance within the operating range (S8: YES), the CPU 71 reduces the gas flow rate flowing through the thermal power adjusting mechanism 30 (S18). That is, the stove 1 reduces the thermal power of the right burner 5 or the left burner 6 on condition that the measurement result of any one of the optical sensors 40 is equal to or less than the operating height. Therefore, it is prevented that the flame of the right burner 5 or the left burner 6 ignites the foreign matter. Further, among the measured voltage values acquired in the process of S21, the CPU 71 sets all the measured heights based on the measured voltage values of the optical sensor 40 corresponding to the specified target burner to be higher than the respective release heights. It is determined whether to show (S22). When all the measured heights based on the measured voltage values of the optical sensor 40 corresponding to the specified target burner indicate a height equal to or higher than the release height (S22: YES), the CPU 71 returns the gas flow rate to the solenoid valve circuit 91. (S26). In this way, the stove 1 restores the gas flow rate after ensuring safety until the height measured by the plurality of optical sensors 40 including the specific sensor becomes equal to or higher than the release height. In this case, the possibility of ignition of the foreign body wire is sufficiently eliminated rather than restoring the gas flow rate on the condition that the height measured by the specific sensor becomes equal to or higher than the release height. Therefore, the stove 1 can adjust the thermal power to ensure the safety of the user.

The set value table and the specific set value table are defined so that the release height defined for each optical sensor 40 is larger than the operating height also defined for each optical sensor 40. Therefore, the stove 1 can return the reduced thermal power to the original thermal power after determining that the foreign matter is surely separated from the periphery of the right burner 5 and the left burner 6.

After the determination in S8, when the amount of change in the measured height of the specific sensor within the operation stabilization time falls within the operation stability width corresponding to the specific sensor (S12: YES), the CPU 71 determines that the foreign matter is in the right burner 5 or the left burner. It is considered that the vehicle is close to No. 6, and the flow rate of gas flowing through the thermal power adjusting mechanism 30 is reduced (S18). After that, after the determination in S22, the CPU 71 maintains the measurement height based on the measured voltage value to be monitored to be higher than the release height, and when the release confirmation time elapses, the foreign matter is on the right burner 5 or the left It is regarded as separated from the burner 6, and the solenoid valve circuit 91 is instructed to return the gas flow rate (S26). The release confirmation time defined for each optical sensor 40 is set to be longer than the operation stabilization time also defined for each optical sensor 40. That is, the stove 1 restores the thermal power of the right burner 5 and the left burner 6 after sufficiently determining that the foreign matter has disappeared from the periphery of the right burner 5 and the left burner 6. The safety of the stove 1 is improved.

The stove 1 can automatically adjust the thermal power of the right burner 5 and the left burner 6 by controlling the gas flow rate at the time of detecting and canceling the detection of foreign matter performed in this way, so that clothing ignition and the like can be prevented. Can be prevented.

For example, the user of the stove 1 may repeatedly stir the contents of the cooking container placed on the trivets 7 and 8 with chopsticks or the like. In this case, if the stove 1 erroneously detects that the arm or the like of the user who stirs the contents of the cooking container is a foreign substance, the reduction and restoration of the gas flow rate are frequently repeated, and the right burner 5 or the left burner 6 is used. It becomes difficult to maintain the thermal power of the user at the desired thermal power of the user. After instructing the solenoid valve circuit 91 to restore the gas flow rate (S26), the CPU 71 starts measuring the elapsed time (S29). Next time, when the CPU 71 determines that there is at least one optical sensor 40 whose measured height indicates a distance within the operating range (S8: YES), the CPU 71 determines whether the elapsed time is 5 seconds or less (S15). When the elapsed time is less than 5 seconds (S15: NO), the CPU 71 returns the process to S1. As a result, when the elapsed time of the stove 1 is shorter than a predetermined time, the gas flow rate reduction control is restricted again. Therefore, the stove 1 can improve the usability of the stove 1 by detecting foreign matter approaching the right burner 5 or the left burner 6 and avoiding frequent repetition of reduction and recovery of the gas flow rate.

In the present embodiment, the stove 1 corresponds to the "stove" of the present invention. The right burner 5 and the left burner 6 correspond to the "burner" of the present invention. The light emitting element 41 corresponds to the "transmitter" of the present invention. The light receiving element 44 corresponds to the "receiver" of the present invention. Infrared light is an example of "transmitted wave" and "reflected wave". Foreign matter is an example of a "measurement target". The optical sensor 40 corresponds to the "sensor" of the present invention. The CPU 71 that executes the process of S8 functions as the "first determination means" of the present invention. The gas supply pipe 27 corresponds to the "gas passage" of the present invention. The CPU 71 that executes the process of S17 functions as the "first flow rate control means" of the present invention. The CPU 71 that executes the process of S20 functions as the "second determination means" of the present invention. The CPU 71 that executes the process of S23 functions as the "second flow rate control means" of the present invention. The operating height corresponds to the "first distance" of the present invention. The release height corresponds to the "second height" of the present invention. Solenoid valves 61 to 63 correspond to the "valve" of the present invention. The operation stabilization time corresponds to the "first time" of the present invention. The cancellation confirmation time corresponds to the "second time" of the present invention. The CPU 71 that executes the process of S13 functions as the "control limiting means" of the present invention.

The present invention is not limited to the above embodiment, and various modifications can be made. The stove 1 has an example of a so-called two-burner gas stove having a right burner 5 and a left burner 6, but even a so-called three-port gas stove having another burner in addition to the right burner 5 and the left burner 6 Good. The stove 1 is not limited to the built-in type, and may be a table stove or a small stove with a cassette type gas supply.

The optical sensors 4A to 4K are arranged on the lower side of the top plate 3 in the housing 2, but may be arranged on the top plate 3 as long as the sensors have a low height in the vertical direction. The top plate 3 does not have to use the glass plate 11. The optical sensors 4A to 4K may be arranged outside the opening 2A of the housing 2 in a plan view. Although the optical sensor 40 uses a reflection type distance measuring sensor using infrared light, it may be a reflection type sensor using ultrasonic waves or a sensor that detects the distance to a foreign object by radar radio waves.

In the above description, an example is shown in which the CPU 71 reduces the gas flow rate from the first flow rate to the second flow rate or the third flow rate according to the measurement height of the optical sensor 40, but the CPU 71 reduces the gas flow rate from the first flow rate. It may be gradually reduced to the third flow rate through the second flow rate. Further, the CPU 71 may set the gas flow rate to "0" in the gas flow rate reduction control.

The operation panel 25 may include a liquid crystal screen in addition to a plurality of buttons, LEDs, and the like. When the operation panel 25 includes a liquid crystal screen, the stove 1 may notify the detection of foreign matter by displaying the liquid crystal screen.

The operating height, operating stable width, operating stable time, release height, and release confirmation time of each of the optical sensors 4A to 4K are merely examples, and can be arbitrarily set in the set value table and the specific set value table. Further, the arrangement positions of the optical sensors 4A to 4K are only an example. For example, the optical sensors 40 arranged in the circumferential direction of the right burner 5 and the left burner 6 are provided in double or triple in the radial direction, and the set value table and the specific set value table are stable in operation according to the arrangement of the optical sensors 40. The width, operation stabilization time, release height, and release confirmation time may be defined in various ways.

In the processing of S26, the CPU 71 instructs the solenoid valve circuit 91 of the gas flow rate to be restored based on the opening status of the solenoid valves 61 and 62 stored in the RAM 73 in the processing of S3. This is an example of flow rate recovery. In the return of the gas flow rate, the gas flow rate to be returned may be determined according to the open state of the solenoid valves 61 and 62 at the time of S26. The open state of the solenoid valves 61 and 62 may be determined by the state of energization of the solenoid valves 61 and 62.

In the present embodiment, the operating range is the range from the upper surface of the top plate 3 to the operating height. On the other hand, in the gas flow rate control process, the process of weakening the thermal power was performed based on the operating height. This means that the range subject to control for weakening the thermal power includes not only the operating range but also the range of the height from the optical sensor 40 located below the top plate 3 to the upper surface of the top plate 3. Become. However, in the use of the stove 1, no foreign matter is located under the top plate 3. Therefore, even if the height below the operating height, that is, the range from the optical sensor 40 to the operating height is set as the operating range, the operating range is substantially the range from the upper surface of the top plate 3 to the operating height. It can be regarded as an indication.

Of course, in the gas flow rate control process, a process of weakening the thermal power may be performed based on the operating range. The operating height is the height on the upper limit side of the operating range. Therefore, the height on the lower limit side may be set in the operating range. In this case, in the processing of S7, S9, and S57, the CPU 71 may determine whether or not the measurement height of the optical sensor 40 is within the operating range. Specifically, in the processing of S7 and S57, the CPU 71 determines whether or not there is an optical sensor 40 whose measured height is equal to or greater than the height on the lower limit side of the operating range and equal to or less than the first operating height. Just do it. Similarly, in the process of S9, the CPU 71 may determine whether or not there is an optical sensor 40 whose measured height is equal to or greater than the height on the lower limit side of the operating range and equal to or less than the second operating height.

The above description also applies to the relationship between the release height and the non-release range. Therefore, even if the height less than the release height, that is, the range less than the release height from the optical sensor 40 is set as the non-release range, the range less than the release height from the upper surface of the top plate 3 is substantially. It can be regarded as indicating the non-release range. Then, similarly to the above, in the gas flow rate control process, a process of returning the thermal power to the original state may be performed based on the non-release range. In this case, in the processing of S35 and S65, the CPU 71 may determine whether or not the measurement height of the optical sensor 40 is outside the non-release range. Specifically, in the process of S35, the CPU 71 may determine whether or not there is an optical sensor 40 whose measurement height is higher than the height on the lower limit side of the non-release range and less than the first release height. Similarly, in the process of S65, the CPU 71 may determine whether or not there is an optical sensor 40 whose measurement height is higher than the height on the lower limit side of the non-release range and less than the second release height.

In the above embodiment, the stove 1 defines the first operating stable width uniformly as "± 10" mm and the second operating stable width uniformly as "± 30" mm. The stove 1 has the first operation stable width of the optical sensors 4A, 4D to 4G, 4I to 4K having a first operating height of 120 mm, and the first operation of the optical sensors 4B, 4H having a first operating height of 70 mm. It may be defined as a width larger than the stable width. Similarly, the stove 1 has a second operating stable width of the optical sensors 4A and 4C having a second operating height of 150 mm larger than the second operating stable width of the optical sensor 4C having a second operating height of 150 mm. It may be defined as a width.

In the set value change process, the CPU 71 changes the set values registered in the set value table and the specific set value table in each process of S35, S38, S45, and S55, but all of S35, S38, S45, and S55. Does not need to be processed. The stove 1 may be executed by selecting any one of S35, S38, S45, and S55 according to the degree of improvement in the usability of the stove 1. Further, although the stove 1 acquires the change candidate value or the like via the operation panel 25 in the set value change process, the stove 1 has other reception units such as a receiving unit capable of receiving a signal from the remote controller or the like. If it is provided, the change candidate value or the like may be acquired through the reception unit.

The stove 1 may arbitrarily determine a cooking mode belonging to a specific mode according to a pattern of thermal power control. In the above specific set value table, the operating height, the operating stable width, the operating stable time, the release height, and the release confirmation time may be arbitrarily defined according to the pattern of the thermal power control. The mode type of the cooking mode is not limited to the above, and may be provided in various ways.

The CPU 71 needs to restore the gas flow rate on the condition that the heights measured by all the optical sensors 40 corresponding to the target burner including the specific sensor indicate a height equal to or higher than the release height of each optical sensor 40. Absent. For example, in addition to the specific sensor, the release height of the optical sensor 40 is defined to be larger than that of the other optical sensors 40, and the measurement height by the optical sensor 40, which is highly important in detecting foreign matter, is the release height. The gas flow rate may be restored on condition that the above height is shown. Further, the gas flow rate may be restored on condition that the measurement height by one or more optical sensors 40 arranged close to the specific sensor indicates a height equal to or higher than the release height of each optical sensor 40. That is, the gas flow rate may be restored on condition that the height measured by two or more optical sensors 40 including the specific sensor indicates a height equal to or higher than the release height of each optical sensor 40.

In the process of S13, the CPU 71 may change the operation stability width associated with the specific sensor in the set value table and the specific set value table to be shorter than the predetermined width. In this case, whether or not the arm or the like of the user during cooking is located in the region of the region R shown in FIG. 8 (B) that overlaps the detection range P is determined more severely than before, so that the stove 1 is set. It becomes difficult to regard the user's arm or the like during cooking as a foreign substance approaching the right burner 5 or the left burner 6. As a result, the stove 1 can avoid repeating unnecessary reduction and restoration of the gas flow rate. Further, the stove 1 may not perform the gas flow rate reduction control of S17 when it is determined in S11 that the first elapsed time is shorter than the predetermined time.

1 Stove 4A-4K, 40 Optical sensor 5 Right burner 6 Left burner 27 Gas supply tube 41 Light emitting element 44 Light receiving element 61-63 Solenoid valve 71 CPU
74 Non-volatile memory 91 Solenoid valve circuit

Claims (4)

With a burner
The measurement is performed by the receiving unit receiving a reflected wave that is arranged outside the burner and has a transmitting unit and a receiving unit, and the transmitted wave transmitted from the transmitting unit is reflected by the measurement target. A sensor that outputs measurement results that indicate the distance to the target,
When the gas flow rate in the gas passage of the burner is the first flow rate, the first determination means for determining whether any of the measurement results output from the sensor indicates the distance equal to or less than the first distance.
When any of the measurement results output from the sensor is determined by the first determination means to indicate the distance equal to or less than the first distance, the gas flow rate is smaller than the first flow rate. The first flow rate control means to make the flow rate,
After the gas flow rate is controlled by the first flow rate control means, the two or more said sensors including the sensor that outputs the measurement result determined to indicate the distance equal to or less than the first distance by the first determination means. A second determination means for determining whether the measurement result output from the sensor indicates the distance equal to or greater than the second distance.
Second flow rate control that sets the gas flow rate to the first flow rate when it is determined by the second determination means that all the measurement results output from the sensor indicate the distance equal to or greater than the second distance. and means,
In the first determination means, when any of the measurement results output from the sensor is considered to indicate the distance equal to or less than the first distance for the first predetermined time, the measurement result is the said. Judging that it indicates the above distance below the first distance,
The second determination means obtains the distance of the second distance or more during the second predetermined time in which all the measurement results output from the two or more sensors are longer than the first predetermined time. When showing, it is determined that the measurement result indicates the distance equal to or greater than the second distance.
Stove, wherein a call. With a burner
The measurement is performed by the receiving unit receiving a reflected wave that is arranged outside the burner and has a transmitting unit and a receiving unit, and the transmitted wave transmitted from the transmitting unit is reflected by the measurement target. A sensor that outputs measurement results that indicate the distance to the target,
When the gas flow rate in the gas passage of the burner is the first flow rate, the first determination means for determining whether any of the measurement results output from the sensor indicates the distance equal to or less than the first distance.
When any of the measurement results output from the sensor is determined by the first determination means to indicate the distance equal to or less than the first distance, the gas flow rate is smaller than the first flow rate. The first flow rate control means to make the flow rate,
After the gas flow rate is controlled by the first flow rate control means, the two or more said sensors including the sensor that outputs the measurement result determined to indicate the distance equal to or less than the first distance by the first determination means. A second determination means for determining whether the measurement result output from the sensor indicates the distance equal to or greater than the second distance.
Second flow rate control that sets the gas flow rate to the first flow rate when it is determined by the second determination means that all the measurement results output from the sensor indicate the distance equal to or greater than the second distance. Means and
After the gas flow rate is controlled by the second flow rate control means, any of the measurement results output from the sensor by the first determination means within the third predetermined time determines the distance equal to or less than the first distance. When it is determined to indicate, the control limiting means for restricting the execution of the control of the gas flow rate by the first flow rate controlling means
Features and to Turkey Nro further comprising a. The stove according to claim 1 or 2 , wherein the second distance is a distance larger than the first distance. Provided in the gas passage and provided with a valve for changing the gas flow rate.
The first flow rate control means and the second flow rate control means control the gas flow rate by operating the valve according to the judgment results of the first judgment means and the second judgment means. The stove according to any one of claims 1 to 3.

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