JP2018128170A - Stove - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stove capable of adjusting firepower with safety of a user secured.SOLUTION: A CPU is configured to: determine whether at least an optical sensor whose measurement height is within an operation range exists or not; when the at least optical sensor whose measurement height is within the operation range exits, indicate an electromagnetic valve circuit to reduce a gas flow rate (S17); acquire a measurement voltage value of each optical sensor containing a specific sensor where it is determined that its measurement height is within the operation range (S19); determine whether a measurement height corresponding to two or more optical sensors containing the specific sensor is not less than a release height corresponding to each optical sensor (S20); and when the measurement height corresponding to the two or more optical sensors containing the specific sensor is not less than the release height corresponding to each optical sensor (S20: YES), indicate the electromagnetic circuit to restore the gas flow rate (S23).SELECTED DRAWING: Figure 13

Description

  The present invention relates to a stove.

  Conventionally, a stove provided with a device for ensuring safety during use of the stove is known. The gas stove disclosed in Patent Document 1 stops the gas when a sensor that detects that clothing has entered the flammable area and a signal indicating that the clothing has entered the flammable area are input from the sensor. And a safety valve that extinguishes the fire of the gas burner.

Japanese Patent No. 2886940

  For example, when a plurality of sensors are arranged on a stove and the burner's thermal power is weakened or extinguished according to the measurement result of the sensor, if the burner's thermal power 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 heating power, it is necessary to ensure the safety of the user when returning the burner to the original heating power.

  The present invention has been made to solve such problems, and an object of the present invention is to provide a stove that can adjust the thermal power while ensuring the safety of the user.

  The stove according to claim 1 of the present invention includes a burner and a plurality of burners arranged outside the burner, and includes a transmission unit and a reception unit, and a transmission wave transmitted from the transmission unit is reflected by a measurement object. When the receiving unit receives the reflected wave, the sensor outputs a measurement result indicating the distance to the measurement target, and the gas flow rate of the gas passage of the burner is the first flow rate. First measurement means for determining whether any of the output measurement results indicates the distance equal to or less than a first distance; and any one 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, a first flow rate control unit that sets the gas flow rate to a second flow rate that is smaller than the first flow rate, and the gas flow rate by the first flow rate control unit. Was controlled The measurement result output from two or more sensors including the sensor that has output the measurement result determined to indicate the distance less than or equal to the first distance by the first determination means is greater than or equal to a second distance. When it is determined by the second determination means that determines whether to indicate the 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, And a second flow rate control means for setting the gas flow rate to the first flow rate.

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

  In the cooker according to claim 3, in addition to the configuration according to claim 1 or 2, the first determination means may be configured such that any one of the measurement results output from the sensor is a first predetermined time. When it is considered that the distance is equal to or less than the first distance, the measurement result is determined to indicate the distance equal to or less than the first distance, and the second determination means is output from the two or more sensors. When all the measurement results indicate the distance that is greater than or equal to the second distance for a second predetermined time that is longer than the first predetermined time, the measurement results are the distance that is greater than or equal to the second distance. It is judged that it shows.

  According to a fourth aspect of the present invention, there is provided a stove according to any one of the first to third aspects, further comprising a valve that is provided in the gas passage and that changes the gas flow rate, the first flow rate control means and the first flow rate control unit. The two flow rate control means controls the gas flow rate by operating the valve according to the judgment results by the first judgment means and the second judgment means.

  According to a fifth aspect of the present invention, in the cooker according to the fifth aspect, in addition to the configuration according to any one of the first to fourth aspects, the first determination unit within a third time after the gas flow rate is controlled by the second flow rate control unit. Control limiting means for restricting the execution of the gas flow rate control to the first flow rate control means when it is determined that any one of the measurement results output from the sensor indicates the distance less than or equal to the first distance. It is provided with.

  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. In other words, the stove according to claim 1 can reduce the heating power of the burner as the gas flow rate decreases, on the condition that any one of the plurality of sensors has a measurement result equal to or less than the first distance. Therefore, it is prevented that the user's clothes are ignited. In addition, the stove according to claim 1 has the gas flow rate after ensuring safety based on the measurement results of two or more sensors including the sensor that has output the measurement result indicating the distance of the first distance or more by the first determination means. Return to the first flow rate. In this case, for example, the user's clothes, etc., rather than the burner's thermal power being restored only on condition that the subsequent measurement result by the sensor indicating the measurement result indicating the first distance or less is equal to or greater than the second distance. The possibility of igniting foreign objects is sufficiently eliminated. Therefore, the stove according to claim 1 can adjust the heating power while ensuring the safety of the user.

  In the stove according to claim 2, in addition to the effect of the invention according to claim 1, since the second distance is larger than the first distance, the clothes of the user are surely moved away from the periphery of the burner. After judging that, the firepower can be restored.

  In addition to the effect of the invention described in claim 1 or 2, the stove described in claim 3 has a second predetermined time that is longer than the first predetermined time. When indicating more than two distances, restore the gas flow. That is, the stove returns the burner's fire power to the original after it has been determined that the user's clothing is no longer around the burner with sufficient time, so the safety of the stove is improved.

  In addition to the effect of the invention according to any one of claims 1 to 3, the stove according to claim 4 changes the gas flow rate according to the judgment by the first judgment means and the second judgment means. Adjust the firepower. Thereby, the stove according to claim 4 can prevent the user from igniting the clothes, and can restore the heating power after ensuring the safety of the user.

  When cooking or the like is performed using a stove, for example, the user's clothes or the like may repeatedly approach the sensor due to the user's action such as repeatedly mixing the contents of the pan with chopsticks. In such a case, for example, when the heating power of the burner is repeatedly reduced or extinguished according to the measurement result of the sensor, the temperature of the contents of the pan may be difficult to be maintained at a desired temperature. The stove according to claim 5, wherein any one of the measurement results output from the sensor by the first determination unit within a third predetermined time after the gas flow rate is controlled by the second flow rate control unit is the first distance. Even if it is determined that the following distance is indicated, the first flow rate control means restricts execution of the gas flow rate control. Therefore, in addition to the effect of the invention according to any one of claims 1 to 4, the stove described in claim 5 detects that the clothes of the stove user are close to the burner. Usability can be improved.

1 is a perspective view of a stove 1. FIG. 1 is an exploded perspective view of a stove 1. FIG. 1 is a plan view of a stove 1. FIG. 3 is a cross-sectional view of the optical sensor 40. FIG. FIG. 3 is a diagram showing a configuration of a thermal power control mechanism 60 provided in a gas supply pipe 27. It is a block which shows the electric constitution of the stove. It is a figure for demonstrating the detection range P of the optical sensor. It is a figure which shows the detection range as the whole of the optical sensors 4A-4K in the stove. It is a figure which shows the data structure of a setting value table. It is a figure which shows the data structure of a specific setting value table. It is a figure which shows the data structure of a cooking mode table. It is a flowchart of a gas flow control process. It is a flowchart of a gas flow control process. It is a flowchart of a setting value change process.

  Embodiments of the present invention will be described below. The structure of the apparatus described below is merely an illustrative example, and is not intended to be limited to that unless otherwise specified. The drawings are used to explain technical features that can be adopted by the present invention. In the following description, left, right, front, 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. The stove 1 is a built-in type stove that is installed by being dropped from above into an opening provided on an upper surface of a kitchen cabinet (not shown), for example. The stove 1 includes a housing 2 and a top plate 3. The housing | casing 2 is formed in a substantially rectangular parallelepiped shape, and upper part opens. The top plate 3 has a substantially rectangular shape in plan view and is fixed to the opening 2 </ b> A at the top of the housing 2. The top plate 3 is larger in the left-right direction than the housing 2 in 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 13 supports the glass plate 11 and the rear plate 12 from below and holds the outer peripheral edge. The glass plate 11 and the rear plate 12 are integrated with each other by a frame 13 to constitute one plate. A black pattern is printed on the lower surface of the glass plate 11, and rectangular transparent windows are formed at positions corresponding to 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 thermal power that can burn gas with high calorie high thermal power when adjusted to maximum thermal power. The left burner 6 is a standard burner provided on the left side of the upper surface of the glass plate 11 and capable of burning gas with a lower calorie than the right burner 5 when adjusted to the maximum heating power. A substantially cylindrical temperature detector 5A is provided at the center of the upper surface of the right burner 5 so as to be movable in the vertical direction, and is always urged upward by a spring (not shown). At the center of the upper surface of the left burner 6, a substantially cylindrical temperature detecting portion 5A is provided so as to be able to move up and down in the vertical direction, and is always urged upward by a spring not shown. At the center of the upper surface of the left burner 6, a substantially cylindrical temperature detection portion 6A is provided so as to be able to move up and down in the vertical direction, and is always urged upward by a spring (not shown). The thermistors 5B and 6B (see FIG. 6) for detecting the pan bottom temperature are stored inside the temperature detectors 5A and 6A, respectively. The thermistors 5B and 6B detect the pan bottom temperature via the upper wall portions of the temperature detectors 5A and 6A that are in contact with the pan bottom.

  A 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 driven, the igniter 35 generates a spark discharge at the ignition electrode and ignites 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 misfire in the right burner 5 based on the thermoelectromotive force generated in the thermocouple 5C. A number of flame holes are also provided on the side surface of the left burner 6, and an ignition electrode (not shown) of the igniter 36 and a thermocouple 6 </ b> C (see FIG. 6) are provided in the vicinity of the flame hole, as in the right burner 5. It is installed so as to face. The igniter 36 is also driven to generate a spark discharge at the ignition electrode and ignite the gas ejected from the flame hole. The thermocouple 6C is heated by a flame formed in the flame hole and generates a thermoelectromotive force. Therefore, the stove 1 can detect 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. The grill exhaust port 10 is provided with a cover 10 </ b> A having a plurality of holes. A grill box (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 cabinet, and an ignition electrode and a thermocouple (not shown) similar to the above are installed near the flame hole. A tray base (not shown) is stored in the grill cabinet. A tray, a grill net, a grill net, etc. (not shown) are placed on the tray. The tray is connected to the lower back 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 cabinet. A handle 14 </ b> A is provided at the lower front portion of the grill door 14. The user can pull out the pan, the grill base, the grill, etc. to the outside of the grill at the same time by grasping the handle 14A and pulling the grill door 14 forward.

  In the center of the front surface of the housing 2, ignition buttons 15, 16, heating power control levers 18, 19, an operation panel 25, and the like are provided in the area on the right side of the grill door 14. The ignition button 15 is provided adjacent to the right side of the grill door 14, and is operated to ignite and extinguish the right burner 5 when pressed. The ignition button 16 is provided on the right side of the ignition button 15 and is operated to ignite and extinguish a grill burner (not shown) provided in the grill cabinet. The grill burner is composed of an upper fire grill burner and a lower fire grill burner (not shown) provided respectively on the upper and lower sides of the left and right side walls in the grill cabinet.

  The thermal power adjustment 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 adjustment lever 19 is provided above the ignition button 16, and includes an upper fire adjustment knob 19A and a lower fire adjustment knob 19B. The upper-fire adjustment knob 19A adjusts the heating power of the upper-fire grill burner by a rotation operation in a substantially horizontal direction. The lower-fire adjustment knob 19B adjusts the heating power of the lower-fire grill burner by a rotation operation in a substantially horizontal direction. The operation panel 25 is provided below the ignition buttons 15 and 16 so as to be rotatable in the front-rear direction. The operation panel 25 includes a plurality of buttons that accept inputs of various operations, an LED that performs notification according to the 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 heating power adjustment lever 20, and the like are provided in the left region of the grill door 14. The ignition button 17 is provided adjacent to the left side of the grill door 14 and is operated to ignite and extinguish the left burner 6 when pressed. The thermal power adjustment 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 (11 in this embodiment) of 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 distance measuring sensor. The optical sensors 4 </ b> A to 4 </ b> K 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 plan view. When the top plate 3 is fixed to the housing 2, the optical sensors 4 </ b> A to 4 </ b> K are located immediately below the top plate 3. The optical sensors 4 </ b> A to 4 </ b> K output a detection wave from the window portion of the glass plate 11 toward the top of the top plate 3 to detect a foreign substance approaching the right burner 5 and the left burner 6. As a foreign object, the user's hand and arm of the stove 1, the sleeve tip of the user's clothes, etc. are assumed. The “outward” of the right burner 5 and the left burner 6 in the present invention means the right burner in the direction intersecting in the vertical direction, such as the front, rear, left, right, and surroundings of the right burner 5 and the left burner 6. 5 and the part located outside the left burner 6.

  Among 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. A region where the optical sensors 4A to 4I are arranged is a detection region C. The photosensors 4A to 4I are arranged along the left-right direction in the detection region C and 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 plan, the optical sensors 4B, 4E, and 4H are arranged in the left-right direction at the same position in the front-rear 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 arrangement positions of the optical sensors 4A to 4I are shifted in the front-rear direction is smaller than the range in which the optical sensors 4A to 4I are shifted in the left-right direction. Therefore, the detection region C in which the optical sensors 4A to 4I are arranged extends long in the left-right direction. That is, the photosensors 4A to 4I form an array that is arranged separately in the left-right direction while allowing some positional deviation in the front-rear direction as a whole.

  Among the optical sensors 4 </ b> A to 4 </ b> I, the optical sensors 4 </ b> A to 4 </ b> D and J are used for controlling the flow rate of gas supplied to the right burner 5. Among them, the optical sensors 4A to 4D are substantially equal to each other along a virtual arc D1 forming a gentle arc along the circumferential direction of the right burner 5 at a position from the right oblique front to the left oblique front of the right burner 5 in plan view. Line up at intervals. The optical sensors 4A to 4D are arranged outside the outer periphery of the frying pan in a plan view when a frying pan having a diameter of 28 cm, for example, is placed on the virtues 7 of the right burner 5.

  The optical sensor 4J is disposed diagonally to the left of the right burner 5 and substantially behind the optical sensor 4D. The arrangement position of the optical sensor 4J is closer to the right burner 5 than the optical sensors 4A to 4D in plan view. In other words, the optical sensor 4J is positioned on the rear side of the optical sensors 4A to 4D in the front-rear direction with respect to the right burner 5, and is positioned on the inner side of 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 a foreign object when the foreign object approaches the right burner 5 rather than the optical sensors 4A to 4D arranged along the virtual line D1.

  The optical sensors 4F to 4I and 4K are used for controlling the flow rate of the gas supplied to the left burner 6. Among them, the optical sensors 4F to 4I are substantially equal along a virtual line D2 forming a gentle arc along the circumferential direction of the left burner 6 at a position from the right front of the left burner 6 to the left front of the left burner 6 in plan view. Line up at intervals. The optical sensors 4F to 4I are disposed outside the outer periphery of the frying pan in a plan view when, for example, a frying pan having a diameter of 28 cm is placed on the virtues 8 of the left burner 6.

  The optical sensor 4K is disposed diagonally to the right of the left burner 6 and substantially behind the optical sensor 4F. The arrangement position of the optical sensor 4K is closer to the left burner 6 than the optical sensors 4F to 4I in plan view. In other words, the optical sensor 4K is located on the rear side of the optical sensors 4F to 4I in the front-rear direction with respect to the left burner 6, and is located on the inner side of 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 a foreign object when the foreign object approaches the left burner 6 rather than the optical sensors 4F to 4I arranged along the virtual line D2.

  The optical sensor 4E is used to control the flow rate of gas supplied to the right burner 5 and the left burner 6. The optical sensor 4E is disposed approximately at the center in the left-right direction between the optical sensor 4D and the optical sensor 4F. When viewed in plan, the optical sensors 4E are arranged in the left-right direction at the same position as the optical sensors 4B, 4H in the front-rear direction. The optical sensor 4E is disposed 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 a reflected wave reflected from a foreign object by the detection wave transmitted from the transmission unit, and measures the distance to the foreign object by applying a triangulation method. It is a sensor. The optical sensor 40 has a substantially rectangular parallelepiped housing 49 made of a light shielding resin. In the housing 49, 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. 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 a long and thin plate shape and is provided at the bottom of the housing 49. The casing 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 the extending 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 48 </ b> A 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 a light position sensor (PSD) that performs output according to a light receiving position of 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 48 </ b> A at the other end of the lead frame 48. Within the casing 49, the light emitting element 41 is located at the bottom of the casing 49 and at one end in the extending direction, and the light receiving element 44 is positioned at the bottom of the casing 49 and the other end in the extending direction. The control IC 47 is provided between the light emitting element 41 and the light receiving element 44 on the mounting surface 48 </ b> A 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 light projecting lens 43 is provided in the housing 49 in front of the light emitting element 41 in the emission direction and on the top of the housing 49. The light projecting lens 43 converges the infrared light incident from the light emitting element 41 into a beam shape and emits the light toward the emission direction. The condensing lens 46 is provided in the housing 49 in front of the light receiving element 44 in the emission direction and at an intermediate portion between the top and bottom of the housing 49. The condensing lens 46 condenses the reflected light obtained by reflecting the infrared light by the foreign matter on the light receiving surface of the light receiving element 44.

  The control IC 47 includes 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 oscillation circuit oscillates at a predetermined frequency. The driving circuit intermittently drives the light emitting element 41 in accordance with the oscillation of the oscillation circuit and emits infrared light a plurality of times during one distance measurement. When the light receiving element 44 receives reflected light in which infrared light is reflected by a foreign object, the output of the light receiving element 44 changes greatly in synchronization with the emission timing of the infrared light. The signal processing circuit acquires a current output obtained when the light receiving element 44 senses light, performs a calculation process of obtaining a mean value by extracting a current value change synchronized with the emission timing of the infrared light, and obtaining a calculation result. Output to the output circuit. The output circuit generates a voltage having a magnitude corresponding to the calculation result, and outputs the voltage as a detection signal corresponding to the distance to the foreign object. If 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 configured as described above measures the distance to the foreign object as follows, and outputs a detection signal indicating a voltage value corresponding to the distance (hereinafter referred to as “measured voltage value”). When the optical sensor 40 detects the foreign matter B1 that is a distance L1 ahead of the light emitting element 41 in the emission direction, the angle of the infrared light emitted from the light emitting element 41 toward the light receiving element 44 out of the reflected light reflected by the foreign matter B1 The reflected light reflected at is indicated by reflected light R1 in the figure. A position where the reflected light R1 is refracted by the condensing lens 46 and is condensed on the light receiving surface of the light receiving element 44 is defined as a light condensing region F1. In FIG. 4, the refraction of light by the light projecting lens 43 and the condensing lens 46 is omitted for convenience of explanation. When the foreign object B2 is located at a distance L2 closer than the distance L1, the reflected light reflected at an angle toward the light receiving element 44 out of the reflected light reflected by the foreign object B2 from the infrared light emitted from the light emitting element 41 is shown in the figure. , Indicated by reflected light R2. The condensing region F2 in which the reflected light R2 is refracted by the condensing lens 46 and collected by the light receiving surface of the light receiving element 44 is collected with respect to the emission position F0 where the infrared light is emitted from the light emitting element 41 in the extending direction. It is located farther than the light region F1. The light receiving element 44 has a resistance value that differs depending on the light condensing region on the light receiving surface, and outputs a current having a magnitude corresponding to the resistance value during distance measurement. Therefore, the stove 1 can obtain the measurement voltage value indicated by the detection signal output from the optical sensor 40, and obtain the distance between the optical sensor 40 and the foreign object by performing a calculation based on the triangulation method.

  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 for improving the cooking performance and safety of the stove 1. An upstream end of the gas supply pipe 27 is connected to a gas inlet (not shown) of the stove 1, and a downstream end is connected to a gas inlet (not shown) of the heating power adjustment mechanism 30. The thermal power adjustment mechanism 30 operates in conjunction with the operation of the ignition button 16 and the thermal power adjustment lever 18 and adjusts the ignition, 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 electromagnetic valves. The gas supply pipe 27 includes two bypass pipes 28 and 29. The bypass pipe 28 is connected between a branch part 65 and a junction part 66 provided in the gas supply pipe 27. The bypass pipe 29 is connected between a branch portion 67 and a junction portion 68 provided in the bypass pipe 28.

  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 as “SV”. An electromagnetic valve 61 is provided between the branching portion 65 and the merging portion 66 of the gas supply pipe 27. In the figure, the solenoid valve is represented as “KSV”. An electromagnetic valve 62 is provided between the branch portion 67 and the junction portion 68 of the bypass pipe 28. An electromagnetic valve 63 is provided between the junction 66 and the thermal power adjustment mechanism 30. The solenoid valves 61 and 62 are keep solenoid valves for adjusting the gas flow rate. The electromagnetic valve 63 is a keep solenoid valve for gas cutoff. Therefore, the response of adjusting the gas flow rate by the electromagnetic valves 61 to 63 is improved.

  The stove 1 opens and closes the electromagnetic valves 61 and 62, respectively, and adjusts the flow rate of the gas flowing through the heating power adjustment mechanism 30 in three stages: a first flow rate, a second flow rate, and a third flow rate. In a state where both the solenoid valves 61 and 62 are open, the first flow rate gas flows through the gas supply pipe 27 and the bypass pipes 28 and 29 to the thermal power adjustment mechanism 30. In a state where either one of the electromagnetic valves 61 and 62 (the electromagnetic valve 62 in this embodiment) is closed, the second flow rate gas flows through the gas supply pipe 27 and the bypass pipe 29 to the thermal power adjustment mechanism 30. When the solenoid valves 61 and 62 are both closed, the third flow rate gas flows through the bypass pipe 29 and into the thermal power adjustment mechanism 30. As a result, the thermal power when the flow rate of the gas flowing through the thermal power adjusting mechanism 30 is adjusted to the maximum by the thermal power adjusting lever 18 (see FIG. 1) is adjusted in three stages: weak thermal power, medium thermal power, and strong thermal power. The first flow rate corresponds to strong thermal power, the second flow rate corresponds to medium thermal power, and the third flow rate corresponds to weak thermal power. The medium thermal power corresponding to the second flow rate is a thermal power between a strong thermal power and a weak thermal power, and the magnitude of the thermal power varies. The second flow rate is preferably a gas flow rate that can maintain a thermal power that can provide a heat amount that hardly affects the cooking while suppressing the thermal power to such an extent that a flame does not protrude from the bottom of the pan.

  The solenoid valves 61 and 62 are operated by the CPU 71 (see FIG. 6) of the control circuit 70, the detection result of the pan 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. Are controlled in accordance with each. Similarly, the operation of the electromagnetic valve 63 and the safety valve 64 is controlled by the CPU 71. Similar to the right burner 5, a safety valve 64 and electromagnetic valves 61 to 63 are provided in a gas supply pipe (not shown) of the grill burner, and the operation is controlled by the CPU 71. Note that the gas supply pipe (not shown) of the left burner 6 is not provided with the bypass pipe 28 and the electromagnetic valve 62. The stove 1 opens and closes the electromagnetic valve 61 corresponding to the left burner 6, and the gas flow rate flowing through the thermal power adjustment mechanism 30 corresponding to the left burner 6 is changed to a first flow rate (corresponding to strong thermal power) and a third flow rate (low thermal power). Adjust) in two steps. The safety valve 64 is opened in conjunction with the depression 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 timer, an I / O interface, etc. (not shown) in addition to the CPU 71, ROM 72, RAM 73, and nonvolatile memory 74. The timer is activated by a program. The CPU 71 performs overall control of various operations of the stove 1. 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 information. The nonvolatile 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, sensor input circuits 86 and 87, a buzzer circuit 88, a safety valve circuit 90, an electromagnetic valve circuit 91, An operation panel 25 and the like are connected to each other. The power supply circuit 81 steps down and rectifies alternating current (for example, 100V) supplied from the power supply 23 to direct current (for example, 5V), and supplies power to various circuits. In the figure, the power source is represented as “AC”. The switch input circuit 82 detects pressing of the ignition buttons 15 to 17 and inputs it to the power supply circuit 81 and the control circuit 70. In the figure, the ignition button is represented as “SW”. The thermistor input circuit 83 inputs the detection values from the thermistors 5B and 6B to the control circuit 70. In the figure, the thermistor is represented as “TH”. The thermocouple input circuit 84 inputs the detection value (signal corresponding to the thermoelectromotive force) from the thermocouples 5C and 6C to the control circuit 70. In the figure, the thermocouple is represented as “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. In the figure, the igniter is represented as “IG”. In FIG. 6, the thermistor, thermocouple, and igniter provided in the grill burner are omitted.

  The sensor input circuit 86 receives detection signals from the temperature detectors 5A and 6A. Each detection signal of the optical sensors 4 </ b> A to 4 </ b> K is input to the sensor input circuit 87. The buzzer circuit 88 drives the piezoelectric buzzer 77 based on a control signal from the CPU 71. The safety valve circuit 90 opens and closes the safety valve 64 based on the control of the CPU 71. The electromagnetic valve circuit 91 opens and closes the electromagnetic valves 61 to 63 based on the control of the CPU 71. The operation panel 25 is used for timer setting by the user, input of selection of thermal power control according to cooking contents, etc., lighting and extinguishing of LEDs according to the control contents of the CPU 71, and the like.

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

  When the foreign substance approaching the right burner 5 and the left burner 6 is detected by the optical sensor 40, the CPU 71 of the stove 1 of the present embodiment operates the electromagnetic valves 61 and 62 to change the gas flow rate from the first flow rate to the second flow rate. Control to reduce the flow rate or the third flow rate is performed. The light emitting element 41 of the optical sensor 40 is arranged with the emission direction of infrared light directed upward of the stove 1 (see FIG. 2). The optical sensor 40 outputs a detection signal corresponding to the distance to the foreign object when the foreign object is located above (the direction in which infrared light is emitted from the light emitting element 41). On the other hand, when a threshold value is set for the magnitude of the detection signal of the optical sensor 40 and processing for determining whether the distance from the foreign object is equal to or less than a predetermined distance is performed, the detection range P of the foreign object by the optical sensor 40 (FIG. 7). Reference) has the following three characteristics.

  As a first characteristic, the optical sensor 40 has a characteristic in which, in the extending direction, the detection range P capable of detecting foreign matter is wider on the side opposite to the light receiving element 44 than the light receiving element 44 side with respect to the light emitting element 41. Have. This characteristic is 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 reflected light that can be incident on the light receiving element 44. In the following description, the direction from the light receiving element 44 toward the light emitting element 41 in the extending 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 emission direction of the light emitting element 41, infrared light from the light emitting element 41 is reflected by the foreign matter B4, and an angle toward the light receiving element 44 among them. The reflected reflected light R4 is refracted by the condensing lens 46 and collected 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 omitted 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 ahead of the emission direction and located between the light emitting element 41 and the light receiving element 44 in the extending direction, the infrared light from the light emitting element 41 is reflected by the foreign matter B5, The reflected light R5 reflected at an angle toward the light receiving element 44 is refracted by the condensing lens 46, thereby condensing in the same condensing region F3 as the reflected light R4 of the foreign object B4. Therefore, the optical sensor 40 outputs a detection signal indicating a measurement voltage value corresponding to the distance L3 as a detection result of the foreign object B5.

  When the foreign object B6 is located at a distance L3 ahead of the emission direction, and is located on the opposite side of the light receiving element 44 from the light receiving element 44 in the extending direction and farther from the light emitting element 41 than the distance G1, the reflection of the foreign object B6 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 object B7 is located at a distance L3 ahead of the emission direction and within the distance G2 larger than the distance G1 on the arrangement direction side of the light emitting element 41 in the extending direction, the infrared ray from the light emitting element 41 The reflected light R <b> 6 reflected by the foreign matter B <b> 7 and reflected at an angle toward the light receiving element 44 can enter 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, thereby condensing at a position different from the condensing region F3. Therefore, the detection signal output from the optical sensor 40 indicates a measured voltage value corresponding to the distance to the foreign object B7 being less than the distance L3. As described above, the optical sensor 40 has a characteristic that the detection range P in which the foreign matter in the extending direction can be detected 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 object is located on the arrangement direction side of the light emitting element 41 in the extending direction, the distance at which the foreign object 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 object when the foreign object is not in front of the light emitting element 41 in the emission direction. As shown in FIG. 4, when the foreign object B3 is located at the distance L1 and is located on the arrangement direction side of the light emitting element 41 in the extending direction, the infrared light from the light emitting element 41 is reflected by the foreign object B3, The reflected light R3 reflected at an angle toward the light receiving element 44 may enter the light receiving element 44 through the condenser lens 46 along the same optical path as the reflected light R2 of the foreign object B2. In this case, since the reflected light R3 of the foreign matter B3 is collected in the same region as the condensing 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. A detection signal indicating a voltage value is output.

  Accordingly, as shown in FIG. 7, the light is reflected by the foreign matter B8 located on the arrangement direction side with respect to the light emitting element 41 in the extending direction and at a distance L4 ahead of the emission direction, and reflected at an angle toward the light receiving element 44. In some cases, the optical path of the reflected light R7 is reflected by the foreign substance B9 located at the distance L3 forward in the emission direction and coincides with the optical path of the reflected light R8 reflected at an angle toward the light receiving element 44. When the reflected light R8 of the foreign material B9 is collected in the light collection region F3, the reflected light R7 of the foreign material B8 that follows the same optical path is also collected in the light collection region F3. In this case, the optical sensor 40 outputs a detection signal indicating a measurement voltage value corresponding to the distance L3 as a detection signal of the foreign object B8. As described above, the optical sensor 40 has a characteristic that the detection range P in which the foreign matter in the emission direction can be detected 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 in a direction perpendicular to the extending direction and deviated from the position of the light emitting element 41 in the direction perpendicular 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 aligned in the extending direction. Accordingly, the foreign matter detection range P by the optical sensor 40 has a predetermined width in the extending direction in which the light emitting element 41 and the light receiving element 44 are arranged as described above, and is substantially in the direction orthogonal to the extending 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 arrangement direction of the optical sensors 4A to 4D has a direction component in a 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 directions of tangent lines of the virtual line D1 at the positions where the optical sensors 4A to 4D are arranged, and are directed to the right side of the stove 1 (see FIG. 8A). On the other hand, the arrangement direction of the optical sensors 4F to 4I has a direction component in a direction from the right side to the left side along the arc formed by the virtual line D2. That is, the arrangement direction of the optical sensors 4F to 4I is the direction of the tangent line of the virtual line D2 at the position where each of the optical sensors 4F to 4I is arranged, and faces the left 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 have the arrangement direction along the imaginary lines D1 and D2 based on the third characteristic, and overall, the direction of the arrangement direction is a horizontal component. It is arranged in the state of having. 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 ranges P of the optical sensors 4A to 4I are 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 develop the respective detection ranges P in front of the right burner 5 and the left burner 6 with almost no gap, and can ensure a wide detection range as a whole.

  Furthermore, in the arrangement of the photosensors 4A to 4I, the photosensor 4A arranged at the right end and the photosensor 4I arranged at the left end are different in arrangement direction. The photosensors 4A arranged at the right end of the line are arranged with a direction component whose arrangement direction is directed to the right based on the first characteristic. Therefore, the arrangement of the photosensors 4A to 4I can secure a wider detection range P on the right side of the photosensor 4A than when the photosensor 4A is arranged to the left. The photosensors 4I arranged at the left end of the arrangement are arranged with a direction component whose arrangement direction is leftward based on the first characteristic. Therefore, the arrangement of the photosensors 4A to 4I can secure a wider detection range P on the left side of the photosensor 4I than in the case where the photosensor 4I is arranged to the right.

  The stove 1 according to the present embodiment is a case where the foreign matter is positioned directly in front of the light emitting element 41 in the emission direction, for example, at a distance of 10 cm, as the foreign matter detection range P by the optical sensor 40 when performing control to reduce the gas flow rate. The measurement voltage value of the detection signal is set to a threshold value (hereinafter referred to as “operation voltage value”). Thus, when a foreign object enters the detection range P having the shape shown in FIG. 7, the distance to the foreign object corresponds to a distance of 10 cm or less. When a foreign object enters the detection range P, the stove 1 can detect that the foreign object is 10 cm or less above the optical sensor 40, that is, that the foreign object has approached the right burner 5 or the left burner 6.

  As described above, the optical sensor 40 is disposed 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 top surface of the top plate 3 and the foreign matter in the vertical direction is defined as “height” with respect to the top surface of the top plate 3. . In the following description, the height of the foreign matter corresponding to the measurement voltage value output when the optical sensor 40 detects the foreign matter is referred to as “measurement height”.

  In the following description, the height of the foreign material serving as a reference for the CPU 71 to perform the process of weakening the heating power of the right burner 5 or the left burner 6 is referred to as “operation height”, and the range from the upper surface of the top plate 3 to the operation height is It is called “operating range”. After the measurement height based on the measurement voltage value output from the optical sensor 40 indicates a height within a predetermined operation range, the CPU 71 of the stove 1 determines a predetermined height with a change amount of the measurement height within a predetermined operation stability range. 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 determines that a foreign object has approached the right burner 5 or the left burner 6, the flow rate of the gas flowing through the heating power adjustment mechanism 30 of the right burner 5 or the left burner 6 is reduced in order to weaken the heating power of the right burner 5 or the left burner 6. Process 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 object is at a height that is relatively far from the optical sensor 40 in the emission direction of the light emitting element 41 of the optical sensor 40, the foreign object is at a height that is 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. For this reason, as the distance from the optical sensor 40 to the foreign object increases, the error generated between the actual height to the foreign object and the measured height may increase. For this reason, in this embodiment, the operation stable width of the optical sensors 4A to 4K is set in advance according to the size of the operation height.

  When a plurality of optical sensors 40 are provided, the optical sensors 40 may receive reflected light in which infrared light emitted from other optical sensors 40 arranged in proximity is reflected by a foreign object. In this case, noise may occur in the measured voltage value indicated by the detection signal output from the optical sensor 40. In addition, the detection signal output from the optical sensor 40 may fluctuate, or a voltage change due to an electrostatic surge or the like may occur in the sensor input circuit 87, the control circuit 70, or the like. May occur. The measured voltage value due to such noise often shows an unstable peak value in a relatively short time. For this reason, the stove 1 is provided with an operation stabilization time, and when the measured height based on the measured voltage value exceeds the operation stabilization time and indicates a stable height within the operation stabilization width, the stove 1 moves to the right burner 5 or the left burner 6. It is considered that a foreign object has approached. Thereby, the stove 1 can avoid performing control which reduces a gas flow rate according to the false detection of the foreign material by noise etc.

  In addition, as the operation stabilization time becomes longer, the time until the stove 1 regards the foreign object as approaching the right burner 5 or the left burner 6 becomes longer. Setting the operation stabilization time that is too long becomes a factor that hinders the stove 1 from quickly performing control to reduce the gas flow rate. In the stove 1, it has been clarified in a prior experiment that the possibility that the flame of the right burner 5 or the left burner 6 is ignited to the detected foreign object increases when the operation stabilization time is 0.5 seconds or more. For this reason, in the stove 1, in order to ensure safety, an operation stabilization time of 0.4 seconds or less is set in advance.

  The stove 1 performs a process of returning the gas flow rate to the original flow rate before the reduction after confirming that there is no foreign matter approaching the right burner 5 or the left burner 6 after performing the control to reduce the gas flow rate. Do. In the following description, the height of the foreign material serving as a reference for the CPU 71 to perform the process of returning the heating power of the right burner 5 or the left burner 6 is referred to as “release height”, and the range from the top surface of the top plate 3 to the release height is This is called “non-release range”. In this embodiment, after the measurement height corresponding to any one of the optical sensors 4A to 4E, 4J indicates the height within the operation range, the operation stabilization time has elapsed 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. In addition, after the measured height corresponding to any one of the optical sensors 4E to 4I and 4K corresponding to the left burner 6 indicates the height within the operating range, the measured stabilization time is the measured height within the operating stability width. Is passed, 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 has elapsed with the measured heights corresponding to all of the optical sensors 4A to 4E, 4J corresponding to the right burner 5 being higher than the predetermined release height. It is determined that there is no foreign matter approaching the right burner 5. Similarly, when a predetermined release confirmation time has elapsed with the measured heights corresponding to all of the optical sensors 4E to 4I, 4K corresponding to the left burner 6 being higher than the predetermined release height. Furthermore, it is determined that the measured height is stable outside the non-release range, and it is determined that there is no foreign matter approaching the left burner 6. Thus, the stove 1 reduces the possibility that the flame of the burner is ignited on the foreign matter by imposing stricter conditions than when detecting the foreign matter when canceling the detection of 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 set value table will be described with reference to FIG. The set value table stores the target burner, the operation height, the operation stability width, the operation stabilization 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 flow rate of the gas supplied to the right burner 5 or the left burner 6, and “right” indicates 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 a target burner. The optical sensors 4E to 4I and 4K use the left burner 6 as a target burner. The set value table includes a table whose control gas flow rate is “third flow rate” and a table whose “second flow rate” is.

  The table in which the control gas flow rate is “third flow rate” is used when performing control to reduce the gas flow rate 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 “second flow rate” corresponds to the operation height corresponding to the case where control is performed to reduce the gas flow rate from the first flow rate to the second flow rate, and the case where the gas flow rate is controlled to the second flow rate. Define the operation stability width, operation stabilization time, release height, and release confirmation time. The operation height, operation stability width, operation stability time, release height, and release confirmation time corresponding to the table whose control gas flow rate is “third flow rate” are the first operation height, the first operation stability width, First operation stabilization time, first release height, and first release confirmation time. The operation height, the operation stability width, the operation stabilization time, the release height, and the release confirmation time corresponding to the table whose control gas flow rate is the “second flow rate” are respectively the second operation height, the second operation stability width, The second operation stabilization time, the second release height, and the second release confirmation time.

  In the table in which the control gas flow rate is “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 and 4H is “ Each of them is defined as 70 "mm. In the stove 1, it is clear from prior experiments that when a foreign object approaches a position within about 100 mm from the right burner 5 or the left burner 6 in which a medium-fired flame is formed, the possibility of the flame igniting the foreign object 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 easily placed above the optical sensors 4B and 4H at a position near 100 mm from the optical sensors 4B and 4H. Taking this into consideration, the stove 1 uses 70 mm, which is smaller than the distance between the handle of the pan and the optical sensors 4B, 4H, when a general one-handed pan is placed on the Gotoku 7,8, The first operating height of the sensors 4B and 4H is set. Moreover, the stove 1 sets the 1st operation height of 120 mm about other optical sensors 40 with a low possibility that a pan handle will be arrange | positioned rather than optical sensors 4B and 4H, in order to ensure safety. Yes. Thus, the set value table defines the first operating height suitable for the arrangement of the optical sensors 4A to 4K in the stove 1. The stove 1 performs control to reduce the gas flow rate based on the set value table, thereby avoiding unnecessary gas flow rate reduction control and improving the usability of the stove 1.

  In the table whose control gas flow rate is “third flow rate”, the first release heights of the optical sensors 4A, 4C to 4G, 4I to 4K are “140” mm or more, and the first release heights of the optical sensors 4B and 4H are set. It is defined as “90” mm or more. The stove 1 is 90 mm larger than the distance between the handle of the pan and the optical sensors 4B and 4H when a general one-handed pan is placed on Gotoku 7 and 8, and the first of the optical sensors 4B and 4H. The release height is set. Further, by returning the gas flow rate from the third flow rate to the second flow rate or more, the optical sensor 4A is used to ensure a sufficient distance that does not ignite foreign matter even if a flame of medium heating power or more is formed in the right burner 5 or the left burner 6. , 4C to 4G, 4I to 4K, the first release height is set to 140 mm. The stove 1 is set such that the release height corresponding to the optical sensor 40 is larger than the operating height corresponding to the optical sensor 40. As a result, the stove 1 can return the gas flow rate to the original when the foreign object moves away from the optical sensor 40 beyond the release height that is separated from the operating height. The stove 1 ensures the safety when returning the gas flow rate to the flow rate before foreign matter detection by setting the foreign matter detection cancellation condition stricter than the foreign matter detection condition.

  The table in which the control gas flow rate is “second flow rate” includes the second operating height and the second operation height for the optical sensors 40 other than the optical sensors 4B and 4J among the optical sensors 4A to 4E and 4J whose target burner is “right”. A two-operation stable width, a second operation stabilization time, a second release height, and a second release confirmation time are defined. The stove 1 sets the second operation height and the second release height to be higher than the first operation height and the first release height corresponding to the same optical sensor 40. When the high-burning flame is formed in the right burner 5 by the gas flow rate of the first flow rate, it is in the same position from the right burner 5 as compared with the case where the flame of the medium heating power is formed by the gas flow rate of the second flow rate. The possibility of igniting foreign objects increases. For this reason, the table whose control gas flow rate is the “second flow rate” has a second operating height higher than the first operating height and the first release height as the operating height corresponding to the flame power of the flame formed in the right burner 5. An operating height and a second release height are defined.

  For example, when a two-handed pan is placed on Gotoku 7, the two handles of the two-handed pan are easily arranged extending in the left-right direction of the pan. The left arm of the user trying to grab the handle on the left side of the two-handed pan is inserted from the position between the right burner 5 and the left burner 6 toward the left front of the right burner 5, so the tip of the left arm is on the right Very easy to approach the burner 5. The stove 1 has a second operation height, a second operation stability width, a second operation stabilization time, a second release height, and a second release confirmation time for the optical sensor 4J disposed diagonally to the left of the right burner 5. Do not define. An item that is “-” in the design value table indicates that there is no definition of the set value. For this reason, the stove 1 is a gas based on the first operation height, the first operation stability width, the first operation stabilization time, the first release height, and the first release confirmation time with respect to the height measured by the optical sensor 4J. Control the flow rate. As a result, the stove 1 can change the gas flow rate to the third flow rate at a time when a foreign substance 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, the ignition to the foreign material approaching the right burner 5 from the diagonally left front is effectively prevented. The stove 1 has the second operating height for the same reason as for the optical sensor 4B, and for avoiding unnecessary gas flow rate control by erroneously detecting the handle of the one-handed pan described above as a foreign object. The second operation stabilization width, the second operation stabilization time, the second release height, and the second release confirmation time are not defined.

  In the table in which the control gas flow rate is “second flow rate”, the second operation stabilization time of the optical sensors 4A, 4C, 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. For this reason, the possibility of the flame of the right burner 5 igniting the foreign matter approaching the position of the optical sensors 4A, 4C, 4D is more likely than the possibility of the flame of the right burner 5 igniting the foreign matter approaching the position of the optical sensor 4E. Is also expected to be high. On the other hand, since the optical sensor 4E is disposed at a position between the right burner 5 and the left burner 6 at the center 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 assumed that 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, 4D as a time shorter than the second operation stabilization time of the optical sensor 4E. Ensures safety. In addition, the stove 1 reduces unnecessary gas flow rate reduction control by defining a second operation stabilization time longer than the optical sensors 4A, 4C, and 4D for the optical sensor 4E. Thus, 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.

  In the table in which the control gas flow rate is “second flow rate”, the second operating height (170 mm) of the optical sensors 4D and 4E is set higher than the second operating height (150 mm) of the optical sensors 4A and 4C. Defined. Since the optical sensors 4D and 4E are arranged at a position closer to the center of the stove 1 than the optical sensors 4A and 4C, the optical sensors 4D and 4E are directed diagonally to the left of the right burner 5 from a position between the right burner 5 and the left burner 6. Can detect foreign objects that can be inserted. As described above, the foreign object inserted in this way is easier to approach the right burner 5 than a foreign object inserted from another position toward the right burner 5. For this reason, the stove 1 performs control to reduce the gas flow rate with respect to the measurement heights of the optical sensors 4A and 4C, under the condition of performing control to reduce the gas flow rate with respect to the measurement heights of the optical sensors 4D and 4E. Set more strictly than the conditions. Thereby, the stove 1 can effectively prevent the foreign matter approaching the right burner 5 from being ignited. 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 return the gas flow rate to the original when the foreign object is sufficiently away from the position where the foreign object easily approaches the right burner 5. As described above, the stove 1 has safety when returning the gas flow rate to the flow rate before the foreign matter detection by strictly setting the foreign matter detection release condition according to the arrangement of the optical sensor 40 with respect to the right burner 5 and the left burner 6. Is secured.

  The set value table defines the first operation stable width as “± 10” mm and the second operation stable width as “± 30” mm as different values. As described above, as the characteristics of the optical sensor 40, the larger the distance from the optical sensor 40 to the foreign object, the larger the error generated between the actual distance from the optical sensor 40 to the foreign object and the distance indicated by the measured voltage value. May be. Thereby, the fluctuation width generated in the measurement voltage value output from the optical sensor 40 may increase as the distance from the optical sensor 40 to the foreign object increases. For this reason, the stove 1 is provided with a second operation stable width associated with the second operation height that is set to be higher than the first operation height in a range wider than the first operation stability width. Thereby, the stove 1 can perform smooth gas flow rate control according to the operation height.

  The specific setting value table will be described with reference to FIG. The specific set value table includes a table whose control gas flow rate is “third flow rate”, similar to the set value table. When a specific mode, which will be described later, is set, a foreign object is less likely to approach the right burner 5 or the left burner 6 than when a cooking mode of another mode type is set. For this reason, when the specific mode is set, the stove 1 performs gas flow reduction control to change 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 first flow rate. The reduction control for setting the flow rate to 2 is omitted. Therefore, the specific set value table does not include a table corresponding to a table in which the control gas flow rate in the set value table is “second flow rate”. Therefore, the stove 1 performs gas flow control according to the specific set value table, and when the foreign substance approaches the right burner 5 or the left burner 6 with the gas flow rate being the first flow rate or the second flow rate, the gas flow rate is changed at a time. A third flow rate can be achieved.

  The cooking mode table will be described with reference to FIG. The stove 1 is provided with a cooking mode corresponding to the cooking content in advance. The stove 1 in which the cooking mode is set automatically performs thermal power control according to the cooking content. The cooking mode table stores a mode type and a control pattern in association with each other. The mode type indicates the type of cooking mode. In the present embodiment, mode types of “rice cooking mode”, “water heater mode”, “high-temperature fried mode”, and “temperature adjustment mode” are provided. The control pattern indicates a thermal power control pattern corresponding to the mode type. The pattern P1 which is the control pattern of the “rice cooking mode” is a state where the right burner 5 or the left burner 6 is medium heat and low heat until the cooking is completed in a state where the pan is placed on either of the five virtues 7 and 8. It is a pattern that automatically repeats the power and extinguishes automatically when cooking is completed. The pattern P2, which is a control pattern of the “water heating mode”, is such that the right burner 5 or the left burner 6 maintains a strong heating power or a medium heating power while the kettle or the like is placed on any of the five virtues 7 and 8, and the kettle hot water boils. Then it is a pattern that extinguishes automatically. The pattern P3, which is the control pattern of the “high temperature stir fry mode”, is a pattern suitable for cooking fried foods in which the right burner 5 or the left burner 6 is mainly maintained at a high heating power so that the bottom temperature is kept high. The pattern P4 which is a control pattern of the “temperature adjustment mode” is a pattern which is mainly used for cooking fried food and automatically controls the heating power so as to keep the temperature of oil or the like in the pan constant. The user can set a desired cooking mode to the stove 1 by performing a predetermined operation input on the operation panel 25 when the stove 1 starts to be used.

  Among these cooking modes, in the “rice cooking mode” and the “water heater mode”, the user can use the right burner 5 or left until the rice cooking or water heating is completed in a state where the pan is placed on the virtues 7 and 8. There is no need to adjust the heating power of the burner 6 or mix the food to be cooked with chopsticks. Therefore, when these modes are set, it is difficult for a foreign object to approach the right burner 5 or the left burner 6. Therefore, the stove 1 is provided with a specific set value table that defines a set of set values for the case where the “rice cooking mode” and the “water heating mode” are set, separately from the set value table. When the “water heating mode” is set, the gas flow rate is controlled based on the specific set value table. Thereby, the stove 1 can perform the thermal power reduction control suitable for the cooking mode. Hereinafter, the “rice cooking mode” and the “water heating mode” are referred to as “specific mode”.

  The stove CPU 71 executes the gas flow rate control process (see FIGS. 12 and 13), and determines that the foreign object has approached the right burner 5 or the left burner 6 based on the detection result of the foreign object by the optical sensor 40. A process of weakening the heating power of the burner 5 or the left burner 6 is performed. Further, when the CPU 71 determines that the approach of the foreign matter is lost based on the detection result by the optical sensor 40 after the heating power of the right burner 5 or the left burner 6 is weakened, the heating power of the right burner 5 or the left burner 6 that has weakened the heating power. Perform processing to restore When the user performs cooking with the right burner 5, a cooking container such as a pan is placed on the virtues 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 depressed. Further, the electromagnetic 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, the ignition button 15 opens and the first flow rate gas flows through the thermal power adjustment mechanism 30. The CPU 71 drives the igniter 35 and ignites the right burner 5. The fire power of the right burner 5 is strong.

  The CPU 71 reads out and executes various programs including a 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 adjustment lever 18 according to the cooking level of the food to be cooked, the progress of cooking, etc., and adjusts the heating power of the right burner 5. The user can perform a predetermined operation input for setting a desired cooking mode on the operation panel 25 when the right burner 5 is ignited. When the cooking mode is set, the CPU 71 performs heat power adjustment according to the cooking mode. Similarly, when the user cooks with the left burner 6, the CPU 71 opens the safety valve 64 and the electromagnetic 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 Flow 1 gas. In response to the ignition of the left burner 6, the CPU 71 reads out various programs including a gas flow rate control process from the ROM 72 and executes them.

  As shown in FIG. 12, when starting the gas flow rate control process, the CPU 71 determines whether any cooking mode of any mode type is received via the operation panel 25 (S1). CPU71 transfers a process to S3, when cooking mode is not received (S1: NO). When the CPU 71 receives the cooking mode (S1: YES), the CPU 71 stores the received mode type in the RAM 73 and sets the received mode type cooking mode (S2). The CPU 71 shifts the process to S3.

  The CPU 71 acquires the gas flow rates flowing through the respective heating power adjusting mechanisms 30 of the right burner 5 and the left burner 6 based on the open state of the electromagnetic valves 61 and 62 (S3). The CPU 71 stores the acquired gas flow rate (that is, either or both of the solenoid valves 61 and 62 are open) in the RAM 73.

  The CPU 71 determines whether 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 indicates whether the mode type indicates a specific mode ("rice cooking mode" or "water heating" Mode "). When the mode type stored in the RAM 73 indicates the specific mode (S4: YES), the CPU 71 refers to the specific set value table (S6). On the other hand, when the cooking mode is not set or when the set cooking mode is not the specific mode (S4: NO), the CPU 71 refers to the setting value table (S5).

  CPU71 acquires the measured voltage value which the detection signal of optical sensor 4A-4K shows, respectively (S7). CPU71 calculates the measurement height corresponding to each of optical sensor 4A-4K based on the acquired measurement voltage value. The CPU 71 compares each of the calculated measurement heights with the operation 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 there is an optical sensor 40 whose measured height indicates a height within the operating range (S8). At this time, when the gas flow rate acquired in the process of S3 is the first flow rate and the CPU 71 refers to the set value table, the optical sensor 40 indicating the measured height is equal to or lower than the first operating height is displayed. First of all, determine whether there is. When there is no optical sensor 40 whose measured height is lower than the first operating height, the CPU 71 determines whether there is an optical sensor 40 whose measured height is lower than the second operating height. . In addition, when the gas flow rate acquired by the process of S3 is the 2nd flow rate and CPU71 is referring the setting value table, the optical sensor 40 which shows height whose measured height is below 1st operation height. Determine if there is. When the CPU 71 refers to the specific set value table, the CPU 71 determines whether there is an optical sensor 40 whose measured height is equal to or lower than the first operating height. Based on these determinations, the CPU 71 determines whether or not there is at least one optical sensor 40 that indicates the measurement height within the first operation range or the second operation range. CPU71 returns a process to S1, when there is no optical sensor 40 in which measured height shows the height below an operation | movement (S8: NO). In this case, the heating power of the right burner 5 and the left burner 6 is maintained at the heating 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 the height within the operating range (S8: YES), the CPU 71 specifies the optical sensor 40 whose measured height indicates the height within the operating range (S9). ). The CPU 71 stores information indicating the identified optical sensor 40 in the RAM 73. The optical sensor 40 specified in the process of S9 is hereinafter referred to as “specific sensor”.

  The CPU 71 determines whether the first elapsed time at which measurement is started in the process of S25 described later is being measured (S10). The first elapsed time indicates the time that has elapsed since the detection of foreign matter in the gas flow rate control process until the next time foreign matter is detected. The CPU 71 measures the first elapsed time using a timer (not shown) provided in the control circuit 70. If the CPU 71 does not measure the first elapsed time (S10: NO), for example, by executing the determination process of S13 for the first time after starting the execution of the gas flow rate control process, the process proceeds to S15.

  In a scene where the stove 1 is used for cooking, for example, the user of the stove 1 performs an operation such as repeatedly stirring the contents of the cooking container placed on Gotoku 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 operation 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. If the user's arm or the like actually has a sufficient height 12 cm or more away from the top plate 3 but is in a region overlapping the detection range P in the region R, 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, it becomes easy for the user to frequently reduce and return the gas flow rate by the operation of stirring the contents of the cooking container. At this time, the thermal power of the right burner 5 or the left burner 6 is not easily maintained at the thermal power desired by the user. In order to avoid such a problem, the stove 1 is configured such that when the first elapsed time from the end of the previous foreign object detection to the next foreign object detection is less than a predetermined time, The execution of control for reducing the flow rate is limited. Thereby, the stove 1 can avoid that the reduction | decrease and return | restoration of a gas flow are unnecessarily repeated according to the operation | movement regarding a user's cooking. Thereby, since the stove 1 can perform the thermal power control according to a user's actual cooking operation | movement, the usability of the stove 1 improves. In the present embodiment, from the result of the previous experiment, when the first elapsed time is 5 seconds or more, control for reducing the gas flow rate is performed. Note that the determination criterion of “5 seconds” is merely an example, and may be arbitrarily determined according to the arrangement and number of the optical sensors 40 in the stove 1, the safety assurance criterion, and the like.

  When measuring the first elapsed time (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 longer (S11: YES), the CPU 71 ends the measurement of the first elapsed time (S12) and clears the timer value. The CPU 71 shifts the process to S15.

  When the first elapsed time is less than 5 seconds (S11: NO), the CPU 71 determines the operation stabilization time associated with the specific sensor in the setting value table and the specific setting value table as “0.2” which is set in advance. "Second" or "0.4" second is changed to "0.5" second (S13). The CPU 71 is changed to an area where the arm of the user during cooking overlaps the detection range P in the area R shown in FIG. 8B by changing the operation stabilization time to be longer than before. When the time is shorter than the operation stabilization time, it is difficult to consider that a foreign object has approached the right burner 5 or the left burner 6. As described above, the CPU 71 changes the detection condition of the foreign matter such as the operation stabilization time in a direction in which the reduction control of the gas flow rate is limited when the first elapsed time is less than the predetermined time. It is possible to avoid repeated reduction and return.

  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 process to S15. The second elapsed time is the time that elapses from when the operation stabilization time is changed in the process of S13 until the next foreign object is detected. When the second elapsed time becomes equal to or longer than the 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, if the CPU 71 determines that there is an optical sensor 40 whose measured height is within the first operation range in the process of S8, the measured voltage value during the first operation stabilization time corresponding to the specific sensor. Monitor changes. When the CPU 71 determines in S8 that there is the optical sensor 40 whose measured height is within the second operation 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 change amount of the measured height during the operation stabilization time changed in the process of S13.

  The CPU 71 determines whether or not the amount of change in the measured 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, if the CPU 71 determines that the measured height is within the first operating range in S8, the CPU 71 determines whether the change amount of the measured height falls within the first operating stability range corresponding to the specific sensor. To do. If the CPU 71 determines that the measured height is within the second operating range in S8, the CPU 71 determines whether the change amount of the measured height falls within the second operating stability width corresponding to the specific sensor. CPU71 returns a process to S1, when the variation | change_quantity of the measurement height within an operation stable time exceeds the operation stable width corresponding to a specific sensor (S16: NO).

  When the change amount of the measured height within the operation stabilization time is within the operation stability width corresponding to the specific sensor (S16: YES), the CPU 71 considers that the measured height is stable within the operation range, As shown in FIG. 13, the solenoid valve circuit 91 is instructed to reduce the gas flow rate (S17). In this process, the CPU 71 instructs the electromagnetic valve circuit 91 to set the gas flow rate to the third flow rate when the determination of S8 is made with reference to the table in which the control gas flow rate is “third flow rate”. The solenoid valve circuit 91 that has received the instruction to set the gas flow rate to the third flow rate closes the solenoid valves 61 and 62, thereby changing the gas flow rate flowing through the thermal power adjustment mechanism 30 to the third flow rate. Thereby, the heating power of the right burner 5 or the left burner is changed from strong heating power or medium heating power to low heating power. The CPU 71 instructs the solenoid valve circuit 91 to set the gas flow rate to the second flow rate when the determination of S8 is made with reference to the table in which the control gas flow rate is “second flow rate”. The solenoid valve circuit 91 that has received the instruction to set the gas flow rate to the second flow rate closes the solenoid valve 62 to change the gas flow rate flowing through the thermal power adjustment mechanism 30 to the second flow rate. Thereby, the thermal power of the right burner 5 is changed from a strong thermal power to a medium thermal power.

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

  CPU71 acquires the measured voltage value which the detection signal of optical sensor 4A-4K shows, respectively (S19). CPU71 specifies the object burner of a specific sensor. The CPU 71 specifies that the target burner is the right burner 5 when the specific sensors are the optical sensors 4A to 4D and 4J. The CPU 71 specifies that the target burner is the left burner 6 when the specific sensors are the optical sensors 4F to 4I and 4K. When the specific sensor is the optical sensor 4E, the CPU 71 causes the right burner 5 to flow when the gas flows through the heating power adjustment mechanism 30 of the right burner 5, and the left burner when the gas flows through the heating power adjustment mechanism 30 of the left burner 6. 6 is identified as the target burner. CPU71 specifies the right burner 5 and the left burner 6 as object burner, when the gas is flowing into the thermal power adjustment mechanism 30 of both the right burner 5 and the left burner 6. FIG.

  Whether the measured height based on the measured voltage value of the optical sensor 40 corresponding to the specified target burner among the measured voltage values acquired in the process of S21 indicates a height equal to or higher than each of the release heights. Is determined (S20). At this time, when the gas flow rate acquired in the process of S3 is the first flow rate and the CPU 71 refers to the setting value table, the optical sensor 40 indicating that the measured height is higher than the second release height is displayed. Determine if there is. When the gas flow rate acquired in the process of S3 is the second flow rate and the setting value table is referred to, the CPU 71 has the optical sensor 40 whose measured height is higher than the first release height. Determine whether. When the CPU 71 refers to the specific set value table, the CPU 71 determines whether there is an optical sensor 40 whose measured height is 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.

  If at least one of the measured heights based on the measured 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 flow rate of the gas flowing through the thermal power adjusting mechanism 30 of the target burner is maintained at the flow rate reduced by the process of S17. The thermal power of the target burner is maintained at the thermal power reduced with the process of S17.

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

  The CPU 71 determines whether or not the release confirmation time has elapsed with the measured height based on the monitored measurement voltage value maintained at a height equal to or higher than the release height (S22). CPU71 returns a process to S19, when the measured height based on the measured voltage value to monitor does not maintain height more than cancellation | release height during the cancellation | release confirmation time (S22: NO). The CPU 71 indicates that the measurement height based on the measurement voltage value of the optical sensor 40 corresponding to the target burner is a release height or higher (S20: YES), and the measurement height is a height higher than the release height. The process of S20 to S22 is repeated until the release confirmation time elapses (S22: YES).

  When the measured 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), the CPU 71 instructs the solenoid valve circuit 91 to return the gas flow rate. (S23). In this process, the CPU 71 instructs the electromagnetic valve circuit 91 based on the open state of the electromagnetic valves 61 and 62 stored in the RAM 73 in accordance with the process of S3. The CPU 71 opens the solenoid valve 61 to the solenoid valve circuit 91 to increase the gas flow rate 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. An instruction is given to set the second flow rate. The solenoid valve circuit 91 that has received the instruction opens the solenoid valve 61 to change the gas flow rate flowing through the thermal power adjustment mechanism 30 from the third flow rate to the second flow rate. Thereby, the heating power of the right burner 5 or the left burner is restored from the weak heating power to the medium weak heating power. When the memory of the open state of the electromagnetic valves 61 and 62 indicates that both of the electromagnetic valves 61 and 62 are open, the CPU 71 opens both the electromagnetic valves 61 and 62 to the electromagnetic valve circuit 91 to increase the gas flow rate. An instruction to set the first flow rate is given. The solenoid valve circuit 91 that has received the instruction opens both the solenoid valves 61 and 62 to change the flow rate of the gas flowing through the thermal power adjustment mechanism 30 from the second flow rate or the third flow rate to the first flow rate. As a result, the heating power of the right burner 5 or the left burner returns from medium heating power or low heating power to strong heating power.

  The CPU 71 issues an instruction to the buzzer circuit 88, stops driving the piezoelectric buzzer 77, and cancels the foreign object detection notification (S24). Further, the CPU 71 turns off a predetermined LED on the operation panel 25 and cancels the notification of foreign object detection. Accordingly, the user can recognize that the stove 1 has finished detecting the foreign matter and that the heating power of the right burner 5 or the left burner has been restored in response to the completion of foreign matter detection. The CPU 71 starts measuring the above-described first elapsed time using a 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 in the process of S14 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 is equal to or longer than a predetermined time (5 seconds in the present embodiment) (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 an arbitrary time may be set as the predetermined time.

  When the second elapsed time is 5 seconds or longer (S27: YES), the CPU 71 changes the operation stabilization time changed in the process of S13 to return to the operation stabilization time predetermined for the specific sensor (S28). ). Accordingly, 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. Thereafter, the CPU 71 ends the measurement of the second elapsed time (S29) and clears the timer value. 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 pan on the virtues 7 and 8, the handle extends to a position indicating the operation range defined by the set value table. Sometimes I want to use a special pan. In addition, when the stove 1 detects a foreign object, the user may desire to change the flame of the right burner 5 or the left burner 6 to extinguish and further improve the safety of the stove 1. In addition, the user may desire to further improve the safety of the stove 1 by changing the conditions for the stove 1 to detect foreign matter such as the operation height and the operation stabilization time to stricter conditions. . Moreover, since the height of the user, the purpose of use of the stove 1, and the like are various, it is assumed that there is a desire to change the operating height according to the user's preference. The CPU 71 executes a design value changing 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 ensured according to a user's request. Process. When the CPU 71 receives a predetermined operation input for changing the setting values defined in the setting value table and the specific setting value table via the operation panel 25 in a state where the electromagnetic valves 61 to 63 are closed, the CPU 71 reads from the ROM 72. Various programs including design value change processing are read and executed.

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

  The CPU 71 determines whether a detection invalidation change instruction has been received (S32). The detection invalidity change instruction is an instruction for not performing the gas flow rate control process according to the measurement voltage value indicated by the detection signal output from the optical sensor 40 identified in the process of S31. If the CPU 71 has not received the detection invalidity change instruction (S32: NO), the process proceeds to S36.

  When the CPU 71 receives the detection invalidity change instruction (S32: YES), the CPU 71 determines whether the optical sensor 40 specified in the process of S31 is one of the optical sensors 4D, 4F, 4J, and 4K (S33). When the optical sensor 40 is one 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 objects are more easily accessible than the other optical sensors 40. Disabling foreign object detection by such optical sensors 4D, 4F, 4J, and 4K is not preferable from the viewpoint of ensuring the safety of the stove 1. Therefore, the CPU 71 does not permit the detection invalid 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 setting value associated with the corresponding optical sensor 40 in the setting value table to “− ( By changing to “No definition” ”, the detection invalidation change is registered (S35). For example, when cooking using the above-mentioned special pan, foreign matter detection by the predetermined optical sensor 40 is not performed, so unnecessary gas flow rate reduction control is not performed. In the design value changing process, by providing the processes of S32, S33, and S35, the user-friendly stove 1 according to the actual usage mode can be provided to the user. The CPU 71 shifts the process to S36.

  When the stove 1 detects a foreign object, the CPU 71 determines whether an instruction to change so that the flame of the right burner 5 or the left burner 6 is extinguished is received (S36). If the stove 1 detects a foreign object and has not received an instruction to change the flame of the right burner 5 or the left burner 6 to extinguish (S36: NO), the process proceeds to S41.

  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), it changes the control gas flow rate item in the setting value table to “no gas flow rate”. Then, extinguishing the flame of the right burner 5 or the left burner 6 is registered (S38). In this process, the CPU 71 may change only the “third gas flow rate” of the control gas flow rate items 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 only the “third gas flow rate” is changed to “no gas flow rate” in the control gas flow rate item, the CPU 71 sets the gas flow rate to the electromagnetic valve circuit 91 in the process of S18 in the gas flow control process described above. Instead of an instruction to set the flow rate, an instruction for preventing gas from flowing into the thermal power adjusting mechanism 30 is given to the electromagnetic valve circuit 91. The solenoid valve circuit 91 that has received the instruction for preventing the gas from flowing into the thermal power adjustment mechanism 30 closes the electromagnetic valves 61 to 63 so that the gas does not flow into the thermal power adjustment mechanism 30. When both the “third gas flow rate” and the “second gas flow rate” are changed to “no gas flow rate” in the control gas flow rate item, the CPU 71 sets the gas flow rate to the solenoid valve circuit 91 in step S18. The process of transmitting an instruction to set the flow rate to 2 is also changed to a process of giving an instruction to the solenoid valve circuit 91 to prevent the gas from flowing to the thermal power adjustment mechanism 30. The design value changing process includes the processes of S36 and S38, and when the stove 1 detects a foreign object, the user who wants to further extinguish the flame of the right burner 5 or the left burner 6 and 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 an instruction to change the operating height has been received (S41). If the CPU 71 has not received an instruction to change the operating height (S41: NO), the process proceeds to S51. CPU71 acquires the change candidate value of the operation height which a user inputs via the operation panel 25, when the instruction | indication which changes an operation height is received (S41: YES) (S43).

  The CPU 71 determines whether or not the obtained 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 the change candidate value. The allowable change range is set to ± 20 mm with respect to the operating height set in the set value table as an 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 change of the operation height, the change allowable range is the lower limit of the changeable operation height of “70 mm”. It stipulates. In this process, the CPU 71 determines whether or not the obtained change candidate value is within a change allowable range with respect to the operating height defined by the setting value table for the optical sensor 40 specified in the process of S31. This allowable change range may be arbitrarily provided according to the arrangement of the optical sensor 40 and the like.

  When the acquired change candidate value is a value within the change allowable range (S43: YES), the CPU 71 changes the setting value associated with the corresponding optical sensor 40 in the setting 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 obtained change candidate value is not within the change allowable range (S43: NO), the CPU 71 proceeds to S51 without performing the process of S45. In the design value changing process, by providing the processes of S41, S42, S43, and S45, the user can change the foreign matter detection condition of the stove 1 within the range in which the safety of the stove 1 is ensured. Usability can be improved.

  The CPU 71 determines whether an instruction to change the operation stabilization time has been received (S51). CPU71 complete | finishes a design value change process, when the instruction | indication which changes an operation stabilization time is not received (S51: NO). When the CPU 71 receives an instruction to change the operation stabilization time (S51: YES), the CPU 71 obtains a change candidate value of the operation stabilization time input by the user via the operation panel 25 (S52).

  The CPU 71 determines whether or not the obtained 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 predetermines a 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 the change candidate value. The allowable change range is set to ± 0.2 seconds with respect to the operation stabilization time set in the set value table as an 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 change of the operation stabilization time, the change allowable range is set to the upper limit of the changeable operation height “0. 5 seconds ". In this process, the CPU 71 determines whether or not the obtained change candidate value is within a change allowable range with respect to the operation stabilization time defined by the setting value table for the optical sensor 40 specified in the process of S31. This allowable change range may be arbitrarily provided according to the arrangement of the optical sensor 40 and the like.

  When the obtained change candidate value is a value within the change allowable range (S53: YES), the CPU 71 changes the setting value associated with the corresponding optical sensor 40 in the setting value table to the change candidate value. Then, the new operation stabilization time is registered in the set value table (S55). Thereafter, the CPU 71 ends the design value changing process. When the obtained change candidate value is not within the change allowable range (S53: NO), the CPU 71 ends the design value change process without performing the process of S55. In the design value changing process, by providing the processes of S51, S52, S53, and S55, the user can change the foreign object detection condition of the stove 1 within the range in which the safety of the stove 1 is ensured. Usability can be improved.

  As described above, the stove 1 has the optical sensor 40 arranged outside the burner. The optical sensor 40 outputs a measurement voltage value indicating the distance to the measurement object. The stove 1 can specify the measurement height based on the measured voltage value when a foreign object such as clothes of the user of the stove 1 comes close to the outside of the right burner 5 or the left burner 6. The CPU 71 determines whether there is even one optical sensor 40 whose measured height indicates a distance within the operating range (S8). When there is an optical sensor 40 whose measured height indicates a distance within the operating range (S8: YES), the CPU 71 reduces the flow rate of gas flowing through the thermal power adjustment mechanism 30 (S18). That is, the stove 1 reduces the heating power of the right burner 5 or the left burner 6 on condition that any one of the optical sensors 40 has a measurement result equal to or lower than the operating height. Therefore, the flame of the right burner 5 or the left burner 6 is prevented from igniting the foreign matter. In addition, the CPU 71 sets all the measurement heights based on the measurement voltage values of the optical sensor 40 corresponding to the specified target burner among the measurement voltage values acquired in the process of S21 to be higher than the respective release heights. It is determined whether to show (S22). When all of the measured heights based on the measured voltage value of the optical sensor 40 corresponding to the specified target burner indicate a height higher than the release height (S22: YES), the CPU 71 returns the gas flow rate to the solenoid valve circuit 91. (S26). As described above, the stove 1 restores the gas flow rate after ensuring the safety until the measurement height by the plurality of optical sensors 40 including the specific sensor is equal to or higher than the release height. In this case, the possibility of ignition of the foreign matter wire is sufficiently eliminated rather than returning the gas flow rate on the condition that the measurement height of the specific sensor is equal to or higher than the release height. Therefore, the stove 1 can adjust the thermal power while ensuring the safety of the user.

  The setting value table and the specific setting value table define the release height defined for each optical sensor 40 so as to be larger than the operating height 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 reliably separated from the periphery of the right burner 5 and the left burner 6.

  After the determination in S8, the CPU 71 determines that the foreign matter is in the right burner 5 or the left burner when the amount of change in the measured height of the specific sensor within the operation stabilization time is within the operation stability range corresponding to the specific sensor (S12: YES). 6 is regarded as approaching 6, and the flow rate of the gas flowing through the thermal power adjustment mechanism 30 is reduced (S18). Thereafter, after the determination in S22, the CPU 71 maintains the measured height based on the monitored voltage value to be higher than the release height, and when the release confirmation time has elapsed, the foreign matter is left in the right burner 5 or The solenoid valve circuit 91 is instructed to return to the gas flow rate assuming that the burner 6 is separated (S26). The release confirmation time defined for each optical sensor 40 is longer than the operation stabilization time similarly defined for each optical sensor 40. That is, the stove 1 restores the heating power of the right burner 5 and the left burner 6 after determining that the foreign matter has disappeared from the periphery of the right burner 5 and the left burner 6 with sufficient time. The safety of the stove 1 is improved.

  The stove 1 can automatically adjust the heating power of the right burner 5 and the left burner 6 by controlling the gas flow rate at the time of foreign object detection and detection cancellation performed in this way. Can be prevented.

  For example, the user of the stove 1 may perform operations such as repeatedly stirring the contents of a cooking container placed on the virtues 7 and 8 with chopsticks or the like. In this case, if the stove 1 erroneously detects that the user's arm or the like performing the operation of stirring the contents of the cooking container is a foreign object, the reduction and return of the gas flow are frequently repeated, and the right burner 5 or the left burner 6 It is difficult to maintain the thermal power of the thermal power desired by the user. After instructing the solenoid valve circuit 91 to return the gas flow rate (S26), the CPU 71 starts measuring elapsed time (S29). When the CPU 71 determines that there is at least one photosensor 40 whose measured height indicates the distance within the operating range next time (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. Thereby, when the elapsed time is shorter than predetermined time, the stove 1 will restrict | limit gas flow reduction control again. Therefore, the stove 1 can improve the usability of the stove 1 by detecting the foreign matter approaching the right burner 5 or the left burner 6 and avoiding frequent reduction and return 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 “transmission unit” of the present invention. The light receiving element 44 corresponds to the “reception unit” of the present invention. Infrared light is an example of “transmitted wave” and “reflected wave”. A foreign object 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 unit” 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. The electromagnetic valves 61 to 63 correspond to “valves” of the present invention. The operation stabilization time corresponds to the “first time” of the present invention. The release 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 unit” of the present invention.

  In addition, this invention is not limited to the said embodiment, A various change is possible. The stove 1 is exemplified by a so-called two-neck gas stove having a right burner 5 and a left burner 6. However, the stove 1 may be a so-called three-or-more 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 a built-in type, and may be a table stove, or a gas stove with a cassette-type small stove.

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

  In the above description, an example 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 has been described. You may reduce to a 3rd flow rate in steps through a 2nd flow rate. Further, the CPU 71 may set the gas flow rate to “0” in the gas flow reduction control.

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

  The operation height, operation stability width, operation stabilization 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. Moreover, the arrangement positions of the optical sensors 4A to 4K are merely examples. For example, the optical sensors 40 arranged in the circumferential direction of each of the right burner 5 and the left burner 6 are provided in double and triple in the radial direction, and the setting value table and the specific setting 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 variously defined.

  In the process of S26, the CPU 71 instructs the solenoid valve circuit 91 on the gas flow rate to be restored based on the open state of the solenoid valves 61 and 62 stored in the RAM 73 in accordance with the process of S3. It is an example of flow volume return. In returning the gas flow rate, the gas flow rate to be returned may be determined according to the open state of the electromagnetic valves 61 and 62 at the time of S26. The open state of the electromagnetic valves 61 and 62 may be determined based on the state of energization of the electromagnetic valves 61 and 62.

  In the present embodiment, the operation range is a range from the upper surface of the top plate 3 to the operation height. On the other hand, in the gas flow rate control process, a process for weakening the heating power was performed based on the operating height. This means that not only the operating range but also the range of height from the optical sensor 40 located below the top plate 3 to the top surface of the top plate 3 is included in the range to be controlled for reducing the thermal power. Become. However, when the stove 1 is used, no foreign matter is positioned below the top plate 3. Therefore, even if the operating range is the height below the operating height, that is, the range from the optical sensor 40 to the operating height, the range from the top surface of the top plate 3 to the operating height is substantially the operating range. It can be considered as shown.

  Of course, in the gas flow rate control process, a process of weakening the heating power based on the operating range may be performed. The operating height is the height on the upper limit side of the operating range. Therefore, the lower limit side height may be set in the operating range. In this case, in the processes of S7, S9, and S57, the CPU 71 may determine whether the measured 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 not less than the lower limit height of the operating range and not more than the first operating height. That's fine. Similarly, in the process of S9, the CPU 71 may determine whether or not there is an optical sensor 40 whose measured height is not less than the height on the lower limit side of the operating range and not more 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 below the release height from the optical sensor 40 is set as the non-release range, the range less than the release height is substantially from the top surface of the top plate 3. It can be regarded as indicating a non-release range. In the same manner as described above, in the gas flow rate control process, a process of returning the heating power based on the non-release range may be performed. In this case, in the processes of S35 and S65, the CPU 71 may determine whether or not the measured 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 measured height is higher than the lower limit side height of the non-release range and less than the first release height. Similarly, in the processing of S65, the CPU 71 may determine whether there is an optical sensor 40 whose measured height is higher than the lower limit side height of the non-release range and less than the second release height.

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

  In the setting value changing process, the CPU 71 changes the setting values registered in the setting value table and the specific setting value table in each process of S35, S38, S45, and S55, but all of S35, S38, S45, and S55. It is not necessary to perform the process. The stove 1 may select and execute one of S35, S38, S45, and S55 according to the degree of improvement in the convenience of the stove 1. In addition, the stove 1 acquires change candidate values and the like via the operation panel 25 in the setting value change process. However, the stove 1 is provided with other receiving units such as a receiving unit that can receive a signal from a remote controller or the like. In the case of provision, change candidate values and the like may be acquired via the reception unit.

  The stove 1 may arbitrarily determine the cooking mode belonging to the specific mode according to the pattern of the thermal power control. The specific setting value table may arbitrarily define the operation height, the operation stability width, the operation stabilization time, the release height, and the release confirmation time according to the thermal power control pattern. The mode type of the cooking mode is not limited to the above, and various modes may be provided.

  The CPU 71 needs to return the gas flow rate on the condition that the measurement heights of all the optical sensors 40 corresponding to the target burner including the specific sensor are higher than the release height of each optical sensor 40. Absent. For example, in addition to the specific sensor, the measurement height by the optical sensor 40 having a high degree of importance in foreign object detection, such as the release height of the optical sensor 40 being defined larger than the other optical sensors 40, 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 measured height by one or more optical sensors 40 arranged close to the specific sensor indicates a height that is higher than the release height of each optical sensor 40. In other words, the gas flow rate only needs to be restored on condition that the measured heights of two or more optical sensors 40 including the specific sensor are higher than the release height of each optical sensor 40.

  The CPU 71 may change the operation stability width associated with the specific sensor in the setting value table and the specific setting value table to be shorter than a predetermined width in the process of S13. In this case, since it is determined more strictly than before whether or not the arm of the user who is cooking is positioned in the region R overlapping the detection range P in the region R shown in FIG. It becomes difficult to regard the user's arm during cooking as a foreign object approaching the right burner 5 or the left burner 6. Thereby, stove 1 can avoid repeating reduction and return of useless gas flow. The stove 1 may not perform the gas flow rate reduction control in S17 when it is determined in S11 that the first elapsed time is shorter than the predetermined time.

1 Stove 4A-4K, 40 Photosensor 5 Right burner 6 Left burner 27 Gas supply pipe 41 Light emitting element 44 Light receiving element 61-63 Electromagnetic valve 71 CPU
74 Nonvolatile memory 91 Solenoid valve circuit

Claims (5)

With a burner,
A plurality of transmitters and receivers are arranged outside the burner, and the reception unit receives the reflected wave reflected by the measurement object from the transmission wave transmitted from the transmitter. A sensor that outputs a measurement result indicating the distance to the object;
When the gas flow rate in the gas passage of the burner is a first flow rate, first determination means for determining whether any of the measurement results output from the sensor indicates the distance equal to or less than a first distance;
When it is determined by the first determination means that any one of the measurement results output from the sensor indicates the distance equal to or less than the first distance, the second gas flow rate is less than the first flow rate. A first flow rate control means for making a flow rate;
After the gas flow rate is controlled by the first flow rate control means, the two or more sensors including the sensor that outputs the measurement result determined by the first determination means to indicate the distance less than the first distance. Second determination means for determining whether the measurement result output from the sensor indicates the distance equal to or greater than a second distance;
A 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. A stove comprising the means.   The stove according to claim 1, wherein the second distance is the distance larger than the first distance. The first determination unit is configured such that when any one of the measurement results output from the sensor is considered to indicate the distance equal to or less than the first distance for a first predetermined time, Determining that the distance is less than or equal to the first distance,
The second determination means sets the distance equal to or greater than the second distance for a second predetermined time in which all the measurement results output from the two or more sensors are longer than the first predetermined time. 3. The stove according to claim 1, wherein when the measurement is performed, it is determined that the measurement result indicates the distance equal to or greater than the second distance. A valve provided in the gas passage for changing the gas flow rate;
The first flow rate control unit and the second flow rate control unit control the gas flow rate by operating the valve in accordance with a determination result by the first determination unit and the second determination unit. The stove according to any one of claims 1 to 3.   After the gas flow rate is controlled by the second flow rate control unit, any one of the measurement results output from the sensor by the first determination unit within a third time indicates the distance equal to or less than the first distance. The stove according to any one of claims 1 to 4, further comprising a control restriction unit that restricts the execution of the control of the gas flow rate to the first flow rate control unit when it is determined.

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