JP6958852B2 - Gas stove - Google Patents

Description

The present invention relates to a gas stove.

Conventionally, there is known a gas stove that can reduce the thermal power of the burner when the user's sleeve approaches the burner. For example, the gas stove described in Patent Document 1 is provided with a light-shielding photosensor floodlight and a light receiver at the front left end and the front right end of the top plate, respectively. The detected light projected from the floodlight crosses the upper surface of the top plate to the left and right and reaches the receiver. The gas stove closes the safety valve to stop the gas and extinguish the burner when the user's sleeve blocks the detection light.

By the way, when cooking, the user stands in front of the gas stove, puts ingredients and seasonings into cooking containers such as pots and frying pans placed on the burner, and mixes ingredients with cooking tools such as balls and slicers. Perform cooking operations. Since the user brings his / her hand closer to the cooking container in the cooking operation, the hand enters the top plate, but at this time, the position and angle at which the hand enters the top plate differ depending on the user's standing position in front of the gas stove. .. The standing position of the user varies depending on the situation at that time, such as the number of burners in use, the dominant hand of the user, the content of the cooking operation, the state of the ingredients in the cooking process, and the preference of the user.

Many cooking containers generally have a circular shape. Therefore, the edge of the cooking container is located near the front end of the top plate on the front side of the burner and away from the front end of the top plate on the side of the burner. When cooking, depending on the standing position of the user, if the user's dominant hand is located in front of the burner, the distance between the user's hand and the edge of the cooking container is relatively close. In this case, the user is afraid of burns, and for example, the cooking operation is performed with the hand located in front of the front end of the top plate. Since the edge of the cooking container is close to the front end of the top plate, when the cooking utensil is moved toward or away from the cooking container in the radial direction during cooking operation, it is not necessary to move the hand onto the top plate to a position where the detection light is blocked. , The cooking utensils reach the center of the cooking container.

Japanese Patent No. 2886940

However, depending on the standing position of the user, when the dominant hand of the user is located diagonally in front of the burner, the distance between the hand of the user and the edge of the cooking container becomes relatively long. In this case, the user is less likely to hesitate to bring his / her hand closer to the cooking container for the cooking operation because the fear of burns is reduced. Since the edge of the cooking container is far from the front end of the top plate, the user may push his / her hand onto the top plate to a position where the detection light is blocked during the cooking operation in order to reach the center of the cooking container. was there. Then, the gas stove was extinguished frequently during cooking, which could be inconvenient. Therefore, it is conceivable to change the design of the gas stove and shift the position where the detected light crosses left and right to the rear of the front end of the top plate to bring it closer to the burner. However, in this case, the cooking container may block the detection light, and if it is erroneously detected as a sleeve, the fire may be extinguished frequently during cooking, which may deteriorate the usability of the gas stove.

An object of the present invention is to provide a gas stove capable of controlling a thermal power by reliably detecting a foreign substance approaching a burner while suppressing a sensitive reaction of a sensor.

The gas stove of the invention according to claim 1 of the present invention includes a burner, a valve provided in the gas passage of the burner to change the gas flow rate flowing through the gas passage, a valve operating means for operating the valve, and a transmission unit. A sensor that has a receiving unit and outputs a detection result of a foreign substance by receiving the detection wave transmitted from the transmitting unit by the receiving unit, and a valve operating means when the foreign substance is detected by the sensor. In a gas stove provided with a control means for controlling the drive of the gas to reduce the gas flow rate, the sensor transmits the detection wave upward, and the height of the foreign matter is high when the foreign matter is located above the sensor. The information indicating the above is output as the detection result, and the cooking utensil is placed on the burner of the first virtual circle that passes through the front part of the top plate around the burner on the top plate of the gas stove. In the area on the front side of the supporting range of the trivet, a group of sensors arranged in a plan view arc shape from one side to the other side in the left-right direction of the burner is configured so as to surround the burner from the front side, and the gas stove The control means is provided with a determination means for determining whether or not the measurement height indicated by the detection result acquired from the sensor is within the operating range within a predetermined height range, and the control means is the sensor by the determination means. When it is determined that the measured height is within the operating range, the driving of the valve operating means is controlled.

The gas stove of the invention according to claim 2 is the sensor arranged at least on the front side of the burner and on the rear side of the sensor group in addition to the configuration of the invention according to claim 1, and is centered on the burner. Moreover, at least one or more inner sensors arranged on the second virtual circle passing radially inside the first virtual circle are further provided.

In addition to the configuration of the invention according to claim 2, the gas stove of the invention according to claim 3 has a control means of the inner sensor rather than the gas flow rate when the gas flow rate is reduced based on the detection result of the sensor group. The gas flow rate when the gas flow rate is reduced based on the detection result is controlled to a small flow rate.

In the gas container of the invention according to claim 4, in addition to the configuration of the invention according to claim 2 or 3, when a foreign substance is detected by the inner sensor, the foreign substance is present based on the detection result of the inner sensor. The control means includes a determination means for determining whether or not the cooking container is placed above the burner, and the control means operates the valve when the determination means determines that the foreign matter is the cooking container. It is characterized in that the means is not driven and the gas flow rate is maintained.

The gas stove of the invention according to claim 5 has the configuration of the invention according to any one of claims 1 to 4, and the sensor group is a first sensor which is one of the sensors included in the sensor group. And one of the sensors included in the sensor group, including the second sensor located behind the first sensor, and the upper limit of the operating range set for the second sensor. The height on the side is higher than the height on the upper limit side of the operating range set for the first sensor.

According to the gas stove of the invention according to claim 1, the sensor group is arranged along the concentric circles of the burner in the area in front of the burner and in front of the installation range of the trivet. That is, since the sensor group is arranged around the burner on the front side of the burner, foreign matter approaching the burner up to the radius of the first virtual circle is reliably detected not only in front of the burner but also on the side. be able to. Therefore, the gas stove can reduce the gas flow rate based on the detection result of the sensor and prevent clothing ignition and the like. In addition, the cooking container generally has a circular shape, and when the cooking container is placed on the burner, the sensor group is located along the outer circumference of the cooking container. Therefore, since the user performs a cooking operation on the ingredients in the cooking container with the cooking utensil, the sensor group cooks from the position where the sensor group does not react sensitively to the center of the cooking container no matter where the hand is extended around the cooking container. Since the tools can be delivered, the gas stove does not impair usability.

According to the gas stove of the invention according to claim 2, in addition to the effect of the invention according to claim 1, when the user extends his / her hand into the first virtual circle for cooking, the user's arm is a sensor. If the sensor group straddles the upper part of the detection range of the group, the sensor group may not be able to detect the user's arm. Since the inner sensor is located closer to the burner in the radial distance of the burner than the sensor group, even if the sensor group cannot be detected, foreign matter that has approached the burner up to the radius of the second virtual circle can be reliably detected. Can be detected. Therefore, the gas stove can reduce the gas flow rate based on the detection result of the sensor and prevent clothing ignition and the like.

According to the gas stove of the invention according to claim 3, in addition to the effect of the invention according to claim 2, the position of the inner sensor is closer to the burner in the radial distance than the position of the sensor group. Therefore, when the inner sensor detects a foreign substance such as the user's arm or arm, the user's hand is closer to the burner than when the sensor group detects the foreign substance, and there is a risk of clothing ignition. Therefore, when the inner sensor detects a foreign substance, the gas stove can prevent clothing ignition and the like by reducing the gas flow rate as compared with the case where the sensor group detects the foreign substance.

According to the gas stove of the invention according to claim 4, in addition to the effect of the invention according to claim 2 or 3, since the position of the inner sensor is closer to the burner than the position of the sensor group, the cooking container is placed above the burner. When placed, the inner sensor may detect the cooking container as a foreign object. When the gas stove determines that the foreign matter detected by the inner sensor is a cooking container, the gas stove does not drive the valve and maintains the gas flow rate, so that the usability is not impaired.

According to the gas stove of the invention according to claim 5, in addition to the effect of the invention according to any one of claims 1 to 4, the position of the second sensor is behind the position of the first sensor and close to the burner. .. By setting the height of the upper limit side of the operating range lower than that of the second sensor for the first sensor away from the burner, the gas stove can suppress the first sensor from reacting sensitively to foreign matter, which is convenient. Does not impair. For the second sensor near the burner, by setting the height on the upper limit side of the operating range higher than the first sensor, the gas stove can quickly detect when a foreign object approaches the burner, and clothing ignition etc. can be prevented. Can be prevented.

The present invention may arbitrarily combine the matters specifying the invention according to claims 1 to 5.

It is a perspective view of the stove 1. It is an exploded perspective view of the stove 1. It is a top view of the stove 1. It is sectional drawing of an optical sensor 40. It is a figure which shows the structure of the thermal power control mechanism 60. This is a block showing the electrical configuration of the stove 1. It is a control table which sets the control value of an optical sensor 40. It is a figure for demonstrating the relationship between the position of a user's wrist, and the operating height. It is a flowchart (1/2) of a gas flow rate control process. It is a flowchart (2/2) of a gas flow rate control process.

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

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

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

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

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

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

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

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

The stove 1 includes a plurality of (10 in this embodiment) optical sensors 4A to 4D and 4F to 4K. The optical sensors 4A to 4D and 4F to 4K each have the same configuration. In the following description, when the optical sensors 4A to 4D and 4F to 4K are generally described, they are referred to as an optical sensor 40. The optical sensor 40 is a known reflection type ranging sensor. The optical sensors 4A to 4D and 4F to 4K are provided inside the housing 2 and are arranged outside the high heat burner 5 and the standard burner 6. The optical sensors 4A to 4D and 4F to 4K are located in the opening 2A of the housing 2 in a plan view. When the top plate 3 is fixed to the housing 2, the optical sensors 4A to 4D and 4F to 4K are located directly below the top plate 3. The optical sensors 4A to 4D and 4F to 4K output a detection wave from the window portion of the glass plate 11 toward the upper side of the top plate 3 to detect foreign matter approaching the high heat burner 5 and the standard burner 6. The "outer" positions of the high heat burner 5 and the standard burner 6 in the present invention intersect in the vertical direction such as front, rear, left, right, and surroundings of the high heat burner 5 and the standard burner 6. The position outside the high heat burner 5 and the standard burner 6 in the direction.

The optical sensors 4A to 4D and 4J are used to control the flow rate of gas supplied to the high-heat burner 5. Among them, the optical sensors 4A to 4D constitute a sensor group 40X arranged on the virtual circle D1A in a plan view. The virtual circle D1A is a virtual arc centered on the high heat burner 5 and passing through the front portion of the top plate 3. The optical sensors 4A to 4D are arranged at substantially equal intervals along the virtual circle D1A at positions diagonally forward to the right and diagonally forward to the left of the high-heat burner 5. The optical sensors 4A to 4D are arranged outside the outer periphery of the wok 22 in a plan view when, for example, a wok 22 having a diameter of 33 cm is placed on the trivet 7 of the high-heat burner 5.

In addition, "along" in the present embodiment is not necessarily limited to the state in which the optical sensors 40 are arranged side by side on one virtual circle drawn in a predetermined direction, and the line is allowed while allowing misalignment. It means the state where it is arranged based on. Further, the virtual circle is not necessarily limited to an arc-shaped line, and may be a straight line or a wavy line.

The optical sensor 4J is arranged on the virtual circle D1B in a plan view. The virtual circle D1B is a virtual arc centered on the high heat burner 5 and passes through the radial inside of the virtual circle D1A. The optical sensor 4J is arranged diagonally to the left of the high-heat burner 5 and behind the sensor group 40X. The optical sensor 4J is arranged outside the outer circumference of the frying pan 24 in a plan view when, for example, a frying pan 24 having a diameter of 28 cm is placed on the trivet 7 of the high-heat burner 5, and is located outside the outer circumference of the wok 22. Placed inside. The arrangement position of the optical sensor 4J is a position closer to the high-heat burner 5 than the optical sensors 4A to 4D in the radial distance. The optical sensor 4J is provided to reliably detect the approach of the foreign matter when the foreign matter approaches the high-heat burner 5 at a radial distance from the optical sensors 4A to 4D arranged along the virtual circle D1A.

The optical sensors 4F to 4I, 4K are used to control the gas flow rate supplied to the standard burner 6. Among them, the optical sensors 4F to 4I form a sensor group 40Y arranged on the virtual circle D2A in a plan view. The virtual circle D2A is a virtual arc centered on the standard burner 6 and passing through the front portion of the top plate 3. The optical sensors 4F to 4I are arranged at substantially equal intervals along the virtual circle D2A at positions diagonally forward to the right and diagonally to the left of the standard burner 6. The optical sensors 4F to 4I are arranged outside the outer periphery of the wok in a plan view when, for example, a wok having a diameter of 33 cm is placed on the trivet 8 of the standard burner 6.

The optical sensor 4K is arranged on the virtual circle D2B in a plan view. The virtual circle D2B is a virtual arc centered on the standard burner 6 and passes through the radial inside of the virtual circle D2A. The optical sensor 4K is arranged diagonally to the right of the standard burner 6 and behind the sensor group 40Y. The optical sensor 4K is arranged outside the outer circumference of the frying pan and inside the outer circumference of the wok with a diameter of 33 cm in a plan view when a frying pan with a diameter of 28 cm is placed on the standard burner 6's trivet 8. Will be done. The arrangement position of the optical sensor 4K is a position closer to the standard burner 6 than the optical sensors 4F to 4I in the radial distance. The optical sensor 4K is provided to reliably detect the approach of the foreign matter when the foreign matter approaches the standard burner 6 at a radial distance from the optical sensors 4F to 4I arranged along the virtual circle D2A.

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

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

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

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

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

The thermal power control mechanism 60 will be described with reference to FIG. Hereinafter, the thermal power control mechanism 60 of the high thermal power burner 5 will be described. The gas supply pipe of the standard burner 6 is provided with a thermal power control mechanism having the same configuration as that of the high thermal power burner 5 except that the bypass pipe 28 and the solenoid valve 62 are not provided. Illustration and description of the thermal power control mechanism will be omitted.

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

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

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

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

The solenoid valves 61 and 62 are operated by the CPU 71 (see FIG. 6) of the control circuit 70, such as the detection result of the pot bottom temperature by the thermistor 5B, the detection result of foreign matter by the optical sensors 4A to 4D, 4J, the time after ignition, etc. It is controlled according to each. Similarly, the operation of the solenoid valve 63 is also controlled by the CPU 71. The safety valve 64 is opened in conjunction with the pressing of the ignition button 15.

The electrical configuration of the stove 1 will be described with reference to FIG. The stove 1 includes a control circuit 70. The control circuit 70 includes a CPU 71, a ROM 72, a RAM 73, a non-volatile memory 74, a timer (not shown), an I / O interface, and the like. The timer is operated by a program. The CPU 71 controls various operations of the stove 1 in an integrated manner. The ROM 72 stores various programs of the stove 1 including a gas flow rate control process (see FIG. 9). The RAM 73 temporarily stores various types of information. The non-volatile memory 74 stores various parameters and the like. The control table (see FIG. 7) described later is stored in the non-volatile memory 74. Further, a height table (not shown) in which the measured voltage value of the optical sensor 40 and the measured height (described later) are associated with each other is also stored in the non-volatile memory 74.

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

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

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

When the optical sensor 40 detects foreign matter such as a hand or an arm approaching the high-heat burner 5 and the standard burner 6, the CPU 71 of the stove 1 of the present embodiment operates the solenoid valves 61 and 62 to control the gas flow rate. Control is performed to reduce the flow rate from the first flow rate to the third flow rate. The light emitting element 41 of the optical sensor 40 is arranged so that the emission direction of infrared light is directed toward the upper side of the stove 1 (see FIG. 2). When the foreign matter is located above (the direction in which the infrared light is emitted from the light emitting element 41), the optical sensor 40 outputs a detection signal according to an accurate distance from the foreign matter. As described above, the optical sensor 40 is arranged under the top plate 3 of the stove 1. In the present embodiment, when the foreign matter is located above the optical sensor 40, the distance between the upper surface of the top plate 3 and the foreign matter in the vertical direction is defined as "height" with reference to the upper surface of the top plate 3. .. In the following description, the height of the foreign matter corresponding to the measured voltage value output when the optical sensor 40 detects the foreign matter is referred to as “measured height”.

The CPU 71 of the stove 1 can determine whether or not the height of the foreign matter is equal to or less than a predetermined height by setting a threshold value for the magnitude of the measured voltage value output by the optical sensor 40. That is, the CPU 71 can detect whether or not a foreign substance has entered within a range from the upper surface of the top plate 3 to a predetermined height in the vertical direction above the optical sensor 40.

The CPU 71 of the stove 1 executes a gas flow control process (see FIG. 9), and when a foreign substance is detected within a predetermined height range by the optical sensor 40, a high-heat burner corresponding to the optical sensor 40 that detects the foreign substance. The process of weakening the thermal power of 5 or the standard burner 6 is performed. In the following description, the height of the foreign matter that is the reference for the CPU 71 to perform the process of weakening the thermal power of the high-heat burner 5 or the standard burner 6 is referred to as "operating height", and the range from the upper surface of the top plate 3 to the operating height is defined as the operating height. , "Operating range". Further, in the gas flow rate control process, the CPU 71 reduces the thermal power of the high thermal power burner 5 or the standard burner 6, and then when the optical sensor 40 no longer detects foreign matter within a predetermined height range, the original thermal power. Perform the process of returning to. In the following description, the height of the foreign matter that is the reference for the CPU 71 to perform the process of returning the thermal power of the high-heat burner 5 or the standard burner 6 is referred to as the "release height", and the range from the upper surface of the top plate 3 to the release height is defined as the release height. , "Non-release range". In the gas flow rate control process, the operating height and the release height (operating range and non-release range) of the optical sensors 4A to 4D and 4F to 4K are set to different heights (different ranges) according to the respective arrangement positions. .. When the gas flow rate control process is executed, the CPU 71 sets control values including the operating height and the release height of the optical sensors 4A to 4D and 4F to 4K, respectively, based on the control table (see FIG. 7).

The control table will be described with reference to FIGS. 7 and 8. In the control table, as the control values for each of the optical sensors 4A to 4D and 4F to 4K, the gas flow rate, the target burner (high heat burner 5 or standard burner 6), the first operating height, the first operating stable width, and the first The operation stabilization time, the first release height, and the first release confirmation time are set. Further, among the optical sensors 40 corresponding to the high-heat burner 5, for the optical sensors 4A, 4C, and 4D, in addition to the above, the second operating height, the second operating stable width, the second operating stable time, and the second. (2) The release height and the second release confirmation time are set. Further, for the optical sensors 4J and 4K, in addition to the above, the cooking container determination width is set. The first operating height and the second operating height are set, for example, with a standard user height of 1600 mm.

The first operating height is the operating height of the optical sensor 40, which is used as a determination reference in the determination process when the CPU 71 reduces the gas flow rate to the third flow rate. The CPU 71 compares the measured height of the optical sensor 40 with the first operating height, and reduces the gas flow rate to the third operating flow rate when the foreign matter is within the operating range. The operating height of the optical sensors 4A, 4C, 4D, 4F, 4G, 4I to 4K is, for example, 120 mm. When a cooking container such as a frying pan 24 or a pan 26 is placed on the trivets 7 and 8, the handle of the cooking container is often arranged above the optical sensors 4A to 4C and 4G to 4I. Among them, the operating heights of the optical sensors 4B and 4H are, for example, 70 mm, and the operating heights of the optical sensors 4A and 4C arranged next to the optical sensors 4B and the optical sensors 4G arranged next to the optical sensors 4H, It is set lower than the operating height of 4I. A voltage value corresponding to the first operating height (hereinafter, referred to as "first operating voltage value") is stored in the control table.

The first operation stable width is a height width set by the CPU 71 as a height range that allows a change in the measured height of the optical sensor 40 in the process of determining the gas flow rate to be reduced to the third flow rate. .. The first operating stable width of the optical sensors 4A to 4D and 4F to 4K is, for example, ± 10 mm.

The cooking container judgment width determines whether or not the cooking container placed on the trivets 7 and 8 is in a position to cover the optical sensors 4J and 4K in the process of the judgment process for reducing the gas flow rate to the third flow rate. The width of the height set as a reference for the operation. When a large cooking container such as a wok 22 having a diameter of 33 cm (see FIG. 3) is placed on the trivets 7 and 8, the wok 22 may cover the upper part of the optical sensors 4J and 4K. In this case, the measured heights of the optical sensors 4J and 4K hardly change. Therefore, if the change in the measured heights of the optical sensors 4J and 4K is within the cooking container determination range, the CPU 71 determines that the cooking container is placed on the trivets 7 and 8 and does not reduce the gas flow rate. The cooking container determination width of the optical sensors 4J and 4K is, for example, ± 3 mm.

The first operation stabilization time is the time for the CPU 71 to observe the change in the measurement height of the optical sensor 40 in the process of determining the gas flow rate to be reduced to the third flow rate. The first operation stabilization time of the optical sensors 4A to 4D and 4F to 4K is, for example, 0.2 seconds. The CPU 71 reduces the gas flow rate to the third flow rate when the change in the measured height of the optical sensor 40 is equal to or less than the first operation stable width during the first operation stabilization time. Further, the CPU 71 determines that the cooking container is located at a position covering the optical sensors 4K and 4J when the change in the measurement height of the optical sensor 40 is equal to or less than the cooking container determination width during the first operation stabilization time. do.

The first release height is the release height of the optical sensor 40, which is used as a determination reference in the determination process when the CPU 71 restores the gas flow rate reduced to the third flow rate. The CPU 71 compares the measured height of the optical sensor 40 with the first release height, and increases the gas flow rate from the third release rate to the original flow rate when the foreign matter is not within the non-release range. The release height of the optical sensors 4A, 4C, 4D, 4F, 4G, 4I to 4K is, for example, 140 mm. The first release height is set higher than the first operating height. Similar to the first operating height, the first release height of the optical sensors 4B, 4H is, for example, 90 mm, which is set lower than the release height of the optical sensors 4A, 4C, 4D, 4F, 4G, 4I to 4K. .. The voltage value corresponding to the first release height (hereinafter, referred to as "first release voltage value") is stored in the control table.

The first release confirmation time is the time for the CPU 71 to observe a state in which the measurement height of the optical sensor 40 is not within the non-release range in the process of determining to restore the gas flow rate reduced to the third flow rate. .. The first release confirmation time of the optical sensors 4A to 4D and 4F to 4K is, for example, 1.0 second. The CPU 71 increases the gas flow rate from the third flow rate to the original flow rate when the measured height of the optical sensor 40 is higher than the first release height during the first release confirmation time.

The second operating height is the operating height of the optical sensors 4A, 4C, 4D which is used as a judgment reference in the judgment process when the CPU 71 reduces the gas flow rate to the second flow rate. The second operating height of the optical sensors 4A and 4C is set higher than the first operating height, for example, 150 mm. The positions of the optical sensors 4A and 4C are close to the range where the handle of the cooking container may be placed, and when the user grabs the handle of the cooking container and cooks, the hands and arms are on the high heat burner 5. It is a position that is rarely approached. Therefore, the second operating height of the optical sensors 4A and 4C is set lower than the second operating height of the optical sensors 4D so as not to react too sensitively.

The optical sensor 4D is on the same virtual circle D1A as the optical sensors 4A and 4C, and is located behind the optical sensors 4A and 4C. When the user extends the hand or arm to the side of the high-heat burner 5 in order to stir the cooking container with a ladle, the hand or arm is at a height close to the user's shoulder at the position of the optical sensor 4D. There is a high possibility that it will pass by. The second operating height of the optical sensor 4D is higher than the second operating height of the optical sensors 4A and 4C so that the approach of the user's wrist to the high-heat burner 5 can be detected quickly in order to prevent clothing ignition. Is also set high, for example 170 mm.

The second operating height of the optical sensor 4B located in the range where the handle of the frying pan 24 or the pan 26 may be arranged is not set in order to ensure the usability of the stove 1. Further, the optical sensors 4A and 4C are arranged near the optical sensor 4B and are located in a range where the handle of the frying pan 24 or the pan 26 may be arranged. On the other hand, the optical sensor 4D is arranged farther from the optical sensor 4B than the optical sensors 4A and 4C, and it is unlikely that the handle of the frying pan 24 or the pan 26 is arranged at the arrangement position. In order to ensure the usability of the stove 1, the second operating height is set higher as the optical sensor 40 is located away from the optical sensor 4B where the handle of the frying pan 24 or the pan 26 is most likely to be arranged. ..

Further, the optical sensor 4J located closest to the high-heat burner 5 reliably detects the hand or arm approaching the high-heat burner 5 and reliably prevents clothing ignition, so that the second operating height is not set. The CPU 71 compares the measured heights of the optical sensors 4A, 4C, and 4D with the second operating height, and reduces the gas flow rate to the second operating flow rate when the foreign matter is within the operating range. A voltage value corresponding to the second operating height (hereinafter referred to as "second operating voltage value") is stored in the control table.

The second operation stable width is a width set by the CPU 71 as a height range that allows a change in the measured height of the optical sensors 4A, 4C, and 4D in the process of determining the gas flow rate to be reduced to the second flow rate. be. The second operating stability width of the optical sensors 4A, 4C, and 4D is, for example, ± 30 mm. The second operation stabilization time is the time for the CPU 71 to observe changes in the measured heights of the optical sensors 4A, 4C, and 4D in the process of determining the gas flow rate to be reduced to the second flow rate. The second operation stabilization time of the optical sensors 4A, 4C, and 4D is, for example, 0.2 seconds. The CPU 71 reduces the gas flow rate to the second flow rate when the change in the measured heights of the optical sensors 4A, 4C, and 4D is equal to or less than the second operation stabilization width during the second operation stabilization time.

The second release height is the release height of the optical sensors 4A, 4C, 4D which is used as a determination reference in the determination process when the CPU 71 restores the gas flow rate reduced to the second flow rate. The CPU 71 compares the measured heights of the optical sensors 4A, 4C, and 4D with the second release height, and increases the gas flow rate from the second release rate to the original flow rate when the foreign matter is not within the non-release range. The release height of the optical sensors 4A and 4C is, for example, 170 mm, and the release height of the optical sensor 4D is, for example, 190 mm. The second release height is set higher than the second operating height. In addition, the voltage value corresponding to the second release height (hereinafter, referred to as "second release voltage value") is stored in the control table.

During the second release confirmation time, the CPU 71 observes a state in which the measurement heights of the optical sensors 4A, 4C, and 4D are not within the non-release range in the process of determining to restore the gas flow rate reduced to the second flow rate. It's time to do it. The second release confirmation time of the optical sensors 4A, 4C, and 4D is, for example, 1.0 second. The CPU 71 increases the gas flow rate from the second flow rate to the original flow rate when the measured heights of the optical sensors 4A, 4C, and 4D are higher than the second release height during the second release confirmation time.

Based on the control table set in this way, the CPU 71 sets the gas flow rate from the first flow rate to the second flow rate to the third flow rate in the high-heat burner 5 when a foreign substance is detected within the operating range by the optical sensor 40. In the standard burner 6, a process of reducing the gas flow rate from the first flow rate to the third flow rate is performed. Further, when the high thermal power burner 5 performs the process of reducing the gas flow rate, the CPU 71 sets the operating height of the optical sensors 4A and 4C higher than the operating height of the optical sensors 4J based on the control table. Similarly, the CPU 71 sets the operating height of the optical sensor 4D higher than the operating height of the optical sensors 4A and 4C based on the control table. Further, the CPU 71 sets the operating height of the optical sensor 4B lower than the operating height of the optical sensors 4A, 4C, 4D, and 4J based on the control table.

Hereinafter, the gas flow rate control process corresponding to the high-heat burner 5 will be described. The gas flow rate control process corresponding to the standard burner 6 is also performed in almost the same manner as in the case of the high heat burner 5, and the description will be simplified below.

When the user cooks with the high heat burner 5, a cooking container such as a pot is placed on the trivet 7 and the ignition button 15 is pressed. The safety valve 64 of the thermal power control mechanism 60 is in a mechanically closed state when the ignition button 15 is not pressed. Further, the solenoid valves 61 to 63 are maintained on the open side when the ignition button 15 is not pressed. When the ignition button 15 is pressed, the safety valve 64 opens in conjunction with the ignition button 15, and the first flow rate of gas flows through the thermal power adjusting mechanism 30. The CPU 71 drives the igniter 35 and ignites the high heat burner 5. The firepower of the high firepower burner 5 becomes a high firepower. The CPU 71 reads various programs including gas flow rate control processing from the ROM 72 and executes them. The flame formed in the flame hole of the high-heat burner 5 is detected by the thermocouple 5C. The user manually operates the heating power adjusting lever 18 according to the degree of baking of the object to be cooked, the progress of cooking, and the like, and adjusts the heating power of the high heating power burner 5.

As shown in FIG. 9, when the gas flow rate control process is started, the CPU 71 reads the control values of the optical sensors 4A to 4D and 4J corresponding to the high heat burner 5 from the control table stored in the non-volatile memory 74. , Stored in RAM 73 (S1). The CPU 71 acquires the detection signals (measured voltage values) of the optical sensors 4A to 4D and 4J, respectively (S5). The timing at which the optical sensors 4A to 4D and 4J each output the detection signal is not synchronized, and the CPU 71 acquires the detection signal from each of the optical sensors 4A to 4D and 4J at different timings.

The CPU 71 compares the measured voltage values of the optical sensors 4A to 4D and 4J with the respective first operating voltage values (S7). The measured voltage value output by the optical sensor 40 of the present embodiment is inversely proportional to the length of the measurement distance. Therefore, when no foreign matter has entered the operating range corresponding to the first operating height or less of each of the optical sensors 4A to 4D and 4J and the measured height is higher than the first operating height, the measured voltage value is the first. Indicates less than one operating voltage value. If none of the optical sensors 4A to 4D, 4J has an optical sensor 40 whose measured height is equal to or less than the first operating height (S7: NO), the CPU 71 advances the process to S9.

The CPU 71 compares the measured voltage values of the optical sensors 4A, 4C, and 4D with the second operating voltage values of each (S9). Since the second operating height is not set for the optical sensors 4B and 4J, they are not subject to determination in the processing of S9. Similar to the above, if no foreign matter has entered the operating range corresponding to the second operating height or less of each of the optical sensors 4A, 4C, 4D and the measured height is higher than the second operating height, the measured voltage value is Indicates less than the second operating voltage value. If none of the optical sensors 4A, 4C, and 4D has an optical sensor 40 whose measured height is equal to or less than the second operating height (S9: NO), the CPU 71 returns the process to S5. The gas flow rate flowing through the thermal power adjusting mechanism 30 by the thermal power control mechanism 60 is maintained at the first flow rate. The thermal power of the high thermal power burner 5 is maintained at the high thermal power.

When a foreign substance such as a user's hand or arm intrudes into the operating range, the measured voltage value of the optical sensor 40 rises and indicates a first operating voltage value or more or a second operating voltage value or more. Among the optical sensors 4A, 4C, and 4D, if there is at least one optical sensor 40 whose measured voltage value is equal to or higher than the second operating voltage value and whose measured height is equal to or lower than the second operating height (S9: YES). The CPU 71 advances the process to S51. The CPU 71 obtains the upper limit height and the lower limit height of the measurement height according to the second operation stable width. Specifically, the CPU 71 reads the measured height corresponding to the measured voltage value based on the height table. The CPU 71 calculates the upper limit height and the lower limit height of the measurement height according to the second operation stable width based on the measurement height. The CPU 71 reads a voltage value (lower limit value) corresponding to the upper limit height and a voltage value (upper limit value) corresponding to the lower limit height based on the height table. The CPU 71 stores the calculation results (upper limit value and lower limit value) in the RAM 73 (S51).

The CPU 71 starts measuring the second operation stabilization time (S53), and acquires a detection signal (measured voltage value) of the optical sensor 40 indicating that the measurement height is equal to or less than the second operation height (S55). The CPU 71 determines whether or not the acquired measured voltage value is equal to or greater than the upper limit value and equal to or less than the lower limit value according to the second operating stability width (S57). When the measured voltage value is equal to or greater than the upper limit value and equal to or less than the lower limit value, and the measured height is equal to or greater than the lower limit height of the second operation stable width and equal to or less than the upper limit height (S57: YES), the CPU 71 has a second operation stabilization time. It is determined whether or not the elapse has passed (S59). When the second operation stabilization time has not elapsed (S59: NO), the CPU 71 returns the process to S55 and repeats the processes of S55 to S59. The CPU 71 monitors whether or not the measured height is maintained within the second operation stabilization width until the second operation stabilization time elapses.

If the measured height of the foreign matter by the optical sensor 40 becomes lower than the lower limit height of the second operation stabilization width or higher than the upper limit height before the lapse of the second operation stabilization time, the foreign matter momentarily falls within the operating range. Since it was only located inside, it can be considered that the possibility of ignition is low. Therefore, when the measured voltage value shows a value larger than the upper limit value or a value smaller than the lower limit value according to the second operation stable width (S57: NO), the CPU 71 returns the process to S5.

When the second operation stabilization time elapses while the measured height of the foreign matter by the optical sensor 40 is maintained at the lower limit height or more and the upper limit height or less of the second operation stabilization width (S59: YES), the CPU 71 is electromagnetically charged. An instruction is given to the valve circuit 91 to control a part of the solenoid valves 61 and 62, that is, the solenoid valve 62 to be closed (S67). The gas flow rate flowing through the thermal power adjusting mechanism 30 by the thermal power control mechanism 60 is reduced from the first flow rate to the second flow rate. The firepower of the high heat burner 5 automatically changes from high heat to medium heat. The CPU 71 issues an instruction to the buzzer circuit 88, drives the piezoelectric buzzer 77, and notifies the detection of foreign matter (S69). Further, the CPU 71 lights a predetermined LED on the operation panel 25 to notify the detection of foreign matter. When the operation panel 25 includes a liquid crystal screen, the detection of foreign matter may be notified by the display on the liquid crystal screen.

As shown in FIG. 10, the CPU 71 acquires the detection signals of the optical sensors 4A to 4D and 4J, respectively (S71). The CPU 71 compares the measured voltage values of the optical sensors 4A to 4D and 4J with the respective first operating voltage values (S73). No foreign matter has entered the operating range corresponding to the first operating height or less of each of the optical sensors 4A to 4D, 4J, and the measured height of the optical sensors 4A to 4D, 4J is the first operating height. If there is no optical sensor 40 indicating the following (S73: NO), the CPU 71 advances the process to S75.

The CPU 71 compares the measured voltage values of the optical sensors 4A, 4C, and 4D with the second release voltage values of each (S75). Since the second release height is not set for the optical sensors 4B and 4J, they are not subject to determination in the processing of S75. When there is a foreign substance in the non-release range corresponding to less than the second release height and the measured height is less than the second release height, the measured voltage value indicates a value larger than the second release voltage value. If any one of the optical sensors 4A, 4C, and 4D has an optical sensor 40 whose measured height is less than the second release height (S75: YES), the CPU 71 returns the process to S71. The gas flow rate flowing through the thermal power adjusting mechanism 30 by the thermal power control mechanism 60 is maintained at the second flow rate. The thermal power of the high thermal power burner 5 is maintained at medium thermal power.

When the foreign matter goes out of the non-release range corresponding to less than the second release height, the measured voltage value of the optical sensor 40 drops, indicating a value equal to or less than the second release voltage value. When all the measured voltage values of the optical sensors 4A, 4C, and 4D are equal to or less than the second release voltage value, and there is no optical sensor 40 indicating that the measurement height is less than the second release height (S75: NO), the CPU71 Procees the process to S77.

The CPU 71 starts measuring the second release confirmation time (S77), and acquires the detection signals of the optical sensors 4A, 4C, and 4D, respectively (S79). The CPU 71 compares the measured voltage values of the optical sensors 4A, 4C, and 4D with the second release voltage values of each (S81). If all the measured voltage values of the optical sensors 4A, 4C, and 4D are equal to or less than the second release voltage value, that is, if there is no optical sensor 40 whose measurement height is less than the second release height (S81: NO), the CPU 71 determines whether or not the second release confirmation time has elapsed (S83). When the second release confirmation time has not elapsed (S83: NO), the CPU 71 returns the process to S79 and repeats the processes of S79 to S83. The CPU 71 monitors whether or not the measured heights of the optical sensors 4A, 4C, and 4D are maintained above the second release height, respectively, until the second release confirmation time elapses.

If any of the optical sensors 4A, 4C, and 4D has an optical sensor 40 whose measured height is less than the second release height before the lapse of the second release confirmation time, the foreign matter is momentarily in the non-release range. Since it was only located outside, the possibility of ignition can be considered to continue. Therefore, the CPU 71 returns the process to S71 when at least one of the optical sensors 4A, 4C, and 4D has an optical sensor 40 whose measured voltage value is larger than the second release voltage value (S81: YES).

When the second release confirmation time elapses while the measured heights of the optical sensors 4A, 4C, and 4D are maintained at or higher than the second release height (S83: YES), the CPU 71 instructs the solenoid valve circuit 91. Is controlled to open the solenoid valves 61 and 62 (S85). The gas flow rate flowing through the thermal power adjusting mechanism 30 by the thermal power control mechanism 60 is increased from the second flow rate to the first flow rate. The firepower of the high heat burner 5 automatically changes from medium heat to high heat. The CPU 71 issues an instruction to the buzzer circuit 88, stops driving the piezoelectric buzzer 77, and cancels the notification of foreign matter detection (S87). Further, the CPU 71 turns off a predetermined LED on the operation panel 25 to cancel the notification of foreign matter detection. The CPU 71 returns the process to S5.

In the determination process of S7 or S73, when at least one of the optical sensors 4A to 4D and 4J is the optical sensor 40 whose measured height is equal to or less than the first operating height (S7: YES or S73: YES). The CPU 71 advances the process to S11. As shown in FIG. 9, the CPU 71 obtains the upper limit height and the lower limit height of the measurement height according to the first operation stable width, and stores them in the RAM 73. Further, in addition to the above, when the optical sensor 40 indicating that the measured height is equal to or less than the first operating height is the optical sensor 4J, the CPU 71 has an upper limit height and a lower limit height of the measured height according to the cooking container determination width. Is stored in the RAM 73 (S11).

Specifically, the CPU 71 reads the measured height corresponding to the measured voltage value based on the height table. The CPU 71 calculates the upper limit height and the lower limit height of the measurement height according to the first operation stable width based on the measurement height. When the optical sensor 40 to be processed is the optical sensor 4J, the CPU 71 further calculates the upper limit height and the lower limit height of the measurement height according to the cooking container determination width based on the measurement height. Based on the height table, the CPU 71 reads the voltage value (lower limit value) corresponding to the upper limit height corresponding to the first operation stable width and the voltage value (upper limit value) corresponding to the lower limit height, and stores them in the RAM 73. .. Similarly, the CPU 71 reads the voltage value (lower limit value) corresponding to the upper limit height according to the cooking container determination width and the voltage value (upper limit value) corresponding to the lower limit height based on the height table, and stores them in the RAM 73. do.

The CPU 71 starts measuring the first operation stabilization time (S13), and acquires a detection signal (measured voltage value) of the optical sensor 40 indicating that the measurement height is equal to or less than the first operation height (S15). The CPU 71 determines whether or not the acquired measured voltage value is equal to or greater than the upper limit value and equal to or less than the lower limit value according to the cooking container determination width (S17). Since the cooking container determination width is not set for the optical sensors 4A to 4D, they are not subject to determination in the processing of S17. Therefore, when the optical sensors 40 to be processed are the optical sensors 4A to 4D (S17: NO), the CPU 71 advances the processing to S21. The optical sensor 40 to be processed is the optical sensor 4J, the measured voltage value is equal to or more than the upper limit value and the lower limit value according to the cooking container determination width, and the measurement height is equal to or more than the lower limit height and the upper limit of the cooking container determination width. When the height is equal to or less than the height (S17: YES), the CPU 71 determines whether or not the first operation stabilization time has elapsed (S19). When the first operation stabilization time has not elapsed (S19: NO), the CPU 71 returns the process to S15 and repeats the processes of S15 to S19. The CPU 71 monitors whether or not the measured height is maintained within the cooking container determination width until the first operation stabilization time elapses.

When the first operation stabilization time elapses while the measurement height of the foreign matter by the optical sensor 40 is maintained at the lower limit height or more and the upper limit height or less of the cooking container determination width (S19: YES), the CPU 71 processes. Is returned to S5. In this case, since a wok 22 (see FIG. 3) having a diameter of 33 cm was placed on the trivet 7 and covered the optical sensor 4J, it is considered that the measured height of the optical sensor 4J showed an almost constant value. It is considered. Therefore, the CPU 71 does not control to reduce the gas flow rate to the third flow rate. As described above, the timing at which the CPU 71 acquires the detection signal from each of the optical sensors 4A to 4D and 4J is not synchronized. Therefore, even if the state in which the cooking container is detected by the optical sensor 4J is maintained, the CPU 71 does not necessarily repeat the determination process of S17 corresponding to the optical sensor 4J. That is, the CPU 71 performs the processing corresponding to the optical sensors 4A to 4D according to the detection signal acquired at the timing when the processing of S5 is executed.

If the measurement height of foreign matter by the optical sensor 4J is lower than the lower limit height or higher than the upper limit height of the cooking container judgment width before the lapse of the first operation stabilization time, that is, the measured voltage value becomes the cooking container judgment width. When a value larger than the corresponding upper limit value or a value smaller than the lower limit value is shown (S17: NO), the CPU 71 advances the process to S21.

The CPU 71 determines whether or not the measured voltage value is equal to or greater than the upper limit value and equal to or less than the lower limit value according to the first operation stable width (S21). When the measured voltage value is equal to or greater than the upper limit value and equal to or less than the lower limit value according to the first operating stable width, and the measured height is equal to or greater than the lower limit height and equal to or less than the upper limit height of the first operating stable width (S21: YES). The CPU 71 determines whether or not the first operation stabilization time has elapsed (S23). When the first operation stabilization time has not elapsed (S23: NO), the CPU 71 acquires the detection signal (measured voltage value) of the optical sensor 40 to be processed (S25). The CPU 71 returns the process to S21 and repeats the processes of S21 to S25. The CPU 71 monitors whether or not the measured height is maintained within the first operation stabilization width until the first operation stabilization time elapses. When it is lower than the lower limit height or higher than the upper limit height of the first operating stability width, that is, when the measured voltage value shows a value larger than the upper limit value corresponding to the first operating stable width or a value smaller than the lower limit value. (S21: NO), the CPU 71 returns the process to S5.

When the first operation stabilization time elapses while the measured height of the foreign matter by the optical sensor 40 is maintained at the lower limit height or more and the upper limit height or less of the first operation stabilization width (S23: YES), the CPU 71 is electromagnetically charged. An instruction is given to the valve circuit 91 to control the closing of the solenoid valves 61 and 62 (S27). The gas flow rate flowing through the thermal power adjusting mechanism 30 by the thermal power control mechanism 60 is reduced from the first flow rate or the second flow rate to the third flow rate. The thermal power of the high thermal power burner 5 automatically changes from high thermal power or medium thermal power to low thermal power. The CPU 71 issues an instruction to the buzzer circuit 88, drives the piezoelectric buzzer 77, and notifies the detection of foreign matter (S29). Further, the CPU 71 lights a predetermined LED on the operation panel 25 to notify the detection of foreign matter. When the operation panel 25 includes a liquid crystal screen, the detection of foreign matter may be notified by the display on the liquid crystal screen.

As shown in FIG. 10, the CPU 71 acquires the detection signals of the optical sensors 4A to 4D and 4J, respectively (S31). The CPU 71 compares the measured voltage values of the optical sensors 4A to 4D and 4J with the first release voltage values of each (S35). When there is a foreign substance in the non-release range corresponding to less than the first release height and the measured height is less than the first release height, the measured voltage value indicates a value larger than the first release voltage value. If any one of the optical sensors 4A to 4D and 4J has an optical sensor 40 whose measured height is less than the first release height (S35: YES), the CPU 71 returns the process to S31. The gas flow rate flowing through the thermal power adjusting mechanism 30 by the thermal power control mechanism 60 is maintained at the third flow rate. The thermal power of the high thermal power burner 5 is maintained at a low thermal power.

When the foreign matter goes out of the non-release range corresponding to less than the first release height, the measured voltage value of the optical sensor 40 drops, indicating a value equal to or less than the first release voltage value. When all the measured voltage values of the optical sensors 4A to 4D and 4J are equal to or less than the first release voltage value and none of the optical sensors 40 indicating the measurement height is less than the first release height disappears (S35: NO), the CPU71 Advances the process to S37.

The CPU 71 starts measuring the first release confirmation time (S37), and acquires the detection signals of the optical sensors 4A to 4D and 4J, respectively (S39). The CPU 71 compares the measured voltage values of the optical sensors 4A to 4D and 4J with the first release voltage values of each (S41). If all the measured voltage values of the optical sensors 4A to 4D and 4J are equal to or less than the first release voltage value, that is, if there is no optical sensor 40 whose measurement height is less than the first release height (S41: NO), the CPU 71 determines whether or not the first release confirmation time has elapsed (S43). When the first release confirmation time has not elapsed (S43: NO), the CPU 71 returns the process to S39 and repeats the processes of S39 to S43. The CPU 71 monitors whether or not the measured heights of the optical sensors 4A to 4D and 4J are maintained above the first release height until the first release confirmation time elapses.

Before the lapse of the first release confirmation time, when there is at least one optical sensor 40 among the optical sensors 4A to 4D, 4J indicating that the measurement height is less than the first release height, that is, the measured voltage value is the first. When there is at least one optical sensor 40 indicating a value larger than the release voltage value (S41: YES), the CPU 71 returns the process to S31.

When the first release confirmation time elapses while the measured heights of the optical sensors 4A to 4D and 4J are maintained at or above the first release height (S43: YES), the CPU 71 advances the process to S85. Control is performed to open the solenoid valves 61 and 62 (S85). The gas flow rate flowing through the thermal power adjusting mechanism 30 by the thermal power control mechanism 60 is increased from the third flow rate to the first flow rate. The firepower of the high heat burner 5 automatically returns from low heat to high heat. The CPU 71 cancels the notification of foreign matter detection (S87), and returns the process to S5.

The CPU 71 executes substantially the same gas flow rate control process on the standard burner 6 and controls the gas flow rate flowing through the thermal power adjusting mechanism 30 based on the detection signals of the optical sensors 4F to 4I and 4K. In the standard burner 6, the gas flow rate is not controlled by the second flow rate, but is controlled between the first flow rate (solenoid valve 61: open) and the third flow rate (solenoid valve 61: closed). Therefore, in the gas flow rate control process corresponding to the standard burner 6, the processes of S9 and S51 to S87 are omitted, and the CPU 71 proceeds to S5 in the case of S7: NO. When the high heat burner 5 and the standard burner 6 are extinguished, the CPU 71 ends the execution of the gas flow rate control process corresponding to each burner.

As described above, the sensor groups 40X and 40Y are arranged along the concentric circles of the high heat burner 5 and the standard burner 6, respectively, at least in front of the high heat burner 5 and the standard burner 6. That is, the sensor groups 40X and 40Y are arranged on the front side of the high heat burner 5 and the standard burner 6 so as to surround the high heat burner 5 and the standard burner 6, respectively. Therefore, the sensor groups 40X and 40Y can detect foreign matter approaching the high heat burner 5 and the standard burner 6 up to the radius of the virtual circles D1A and D2A not only in front of the high heat burner 5 and the standard burner 6 but also on the side. , Can be detected reliably. Therefore, the stove 1 can reduce the gas flow rate based on the detection result of the optical sensor 40 and prevent clothing ignition and the like. Further, the cooking container is generally circular, and when the cooking container is placed on the high heat burner 5 and the standard burner 6, the sensor groups 40X and 40Y are located along the outer periphery of the cooking container. Therefore, even if the user places his / her hand around the cooking container and uses the cooking utensil to perform a cooking operation on the ingredients in the cooking container, the sensor groups 40X and 40Y are sensitive if they are outside the virtual circles D1A and D2A. Since it is possible to suppress the reaction to the stove 1, the stove 1 does not impair the usability.

When the user extends his / her hand into the virtual circles D1A and D2A for cooking and the part near the shoulder of the user's arm straddles the upper part of the detection range of the sensor group 40X / 40Y, the sensor group 40X / 40Y May not be able to detect the user's skill. The optical sensors 4J and 4K are located closer to the high-heat burner 5 and the standard burner 6 in the radial distance of the high-heat burner 5 and the standard burner 6 than the sensor groups 40X and 40Y, respectively. Therefore, even if the sensor groups 40X and 40Y cannot be detected, the optical sensors 4J and 4K can reliably detect foreign matter that has approached the high-heat burner 5 and the standard burner 6 up to the radius of the virtual circles D1B and D2B, respectively. Can be detected. Therefore, the stove 1 can reduce the gas flow rate based on the detection result of the optical sensor 40 and prevent clothing ignition and the like.

The positions of the optical sensors 4J and 4K are closer to the high-heat burner 5 and the standard burner 6 in the radial distance than the positions of the sensor groups 40X and 40Y, respectively. Therefore, when the optical sensors 4J and 4K detect foreign matter such as the user's arm and arm, the user's hand is closer to the high heat burner 5 and the standard burner 6 than when the sensor groups 40X and 40Y detect the foreign matter. , There is a risk of clothing ignition. Therefore, when the optical sensors 4J and 4K detect foreign matter, the stove 1 can prevent clothing ignition and the like by reducing the gas flow rate as compared with the case where the sensor groups 40X and 40Y detect foreign matter. ..

Since the positions of the optical sensors 4J and 4K are closer to the high heat burner 5 and the standard burner 6 than the positions of the sensor groups 40X and 40Y, when the cooking container is placed above the high heat burner 5 and the standard burner 6, the light is emitted. The sensors 4J and 4K may detect the cooking container as a foreign substance. When the stove 1 determines that the foreign matter detected by the optical sensors 4J and 4K is a cooking container, the stove 1 does not drive the solenoid valve 61 and maintains the gas flow rate, so that the usability is not impaired.

The position of the optical sensor 4D is behind the positions of the optical sensors 4A and 4C and is close to the high-heat burner 5. For the optical sensors 4A and 4C away from the high-heat burner 5, by setting the height on the upper limit side of the operating range lower than the optical sensor 4D, the optical sensors 4A and 4C of the stove 1 are sensitive to foreign matter. The reaction can be suppressed and the usability is not impaired. For the optical sensor 4D close to the high heat burner 5, by setting the height on the upper limit side of the operating range higher than the optical sensors 4A and 4C, the stove 1 can be used when a foreign object approaches the high heat burner 5. It can be detected quickly and can prevent clothing ignition and the like.

The present invention is not limited to the above embodiment, and various modifications can be made. The optical sensors 4A to 4D included in the sensor group 40X are arranged on the front side of the high heat burner 5, but may be arranged on the side or the rear side of the high heat burner 5 along the virtual circle D1A. Similarly, the optical sensors 4F to 4I included in the sensor group 40Y may be arranged on the side or the rear side of the standard burner 6 along the virtual circle D2A. Further, the number of optical sensors 40 included in the sensor groups 40X and 40Y may be arbitrarily changed. Although one optical sensor 4J is mentioned as an example of the optical sensor 40 arranged along the virtual circle D1B, two or more optical sensors 40 may be arranged along the virtual circle D1B. Similarly, not only one optical sensor 4K but also two or more optical sensors 40 may be arranged along the virtual circle D2B.

In the present embodiment, the sensor groups 40X and 40Y along the virtual circles D1A and D2A are arranged on the outer side in the radial direction of the wok 22 having a diameter of 33 cm as an example. Further, as an example, the optical sensors 4J and 4K along the virtual circles D1B and D2B are arranged on the radial inside of the wok 22 having a diameter of 33 cm and on the radial outside of the frying pan 24 having a diameter of 28 cm. The sizes of these virtual circles D1A, D2A, D1B, and D2B are only guidelines, and the diameters of the virtual circles D1A, D2A, D1B, and D2B and the arrangement positions of the optical sensors 4A to 4D, 4F to 4K are appropriately changed. be able to. For example, the sensor groups 40X and 40Y may be arranged on the radial inside of the wok 22 having a diameter of 33 cm and on the radial outside of the frying pan 24 having a diameter of 28 cm. In this case, it is preferable that the thermal power of the high-heat burner 5 and the standard burner 6 is such that the flame does not protrude from the bottom of the wok 22 having a diameter of 33 cm, even if the thermal power is high. Further, the optical sensors 4J and 4K may be arranged on the outer side in the radial direction of the wok 22 having a diameter of 33 cm.

When the optical sensors 4J and 4K detected the cooking container, the CPU 71 did not control to reduce the heating power. The optical sensor 40 to be controlled is not limited to the optical sensors 4J and 4K, and all optical sensors 4A to 4D and 4F to 4K may be targeted. Further, the user may be able to set an arbitrary optical sensor 40 as a control target by operating the operation panel 25. For example, it is effective when heating a large pot, a barrel, or the like having a diameter of more than 33 cm.

The stove 1 has taken as an example a so-called two-port gas stove having a high-heat burner 5 and a standard burner 6, but may be a so-called three-port gas stove having a small burner in addition to the high-heat burner 5 and the standard burner 6. .. The stove 1 is not limited to the built-in type, and may be a table stove or a small stove with a cassette type gas supply.

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

Even when a foreign substance is detected by the optical sensors 4F to 4I, 4K corresponding to the standard burner 6, the CPU 71 changes the gas flow rate from the first flow rate to the first flow rate according to the distance from the foreign substance by the optical sensors 4F to 4I, 4K. It may be gradually reduced to the third flow rate through two flow rates.

The gas supply pipe 27 may switch the gas flow rate in two steps by reducing the number of bypass pipes and the number of solenoid valves (for example, as one bypass pipe and one solenoid valve). Alternatively, the gas supply pipe 27 may increase the number of bypass pipes and the number of solenoid valves to switch the gas flow rate in multiple stages. In this case, when controlling the heating power to the medium heating power, the stove 1 may change the gas flow rate according to the cooking content and control the heating power according to the cooking content. The stove 1 sets the number of solenoid valves to be closed when the second flow rate is controlled according to the cooking content specified by the user in the operation of the operation panel 25 or the detection result of the pot bottom temperature by the thermistors 5B and 6B. You may change it.

In the present embodiment, the measurement height, the operating height, and the release height are defined as the height above the optical sensor 40 with respect to the upper surface of the top plate 3 and the distance between the upper surface of the top plate 3 and the foreign matter in the vertical direction. However, the height may be defined as the vertical distance with respect to the position of the light emitting element 41 of the optical sensor 40.

The first operating height, the first release height, the second operation height, and the second release height of the optical sensors 4A to 4D and 4F to 4K are only examples, and the positional relationship and operation of the stove 1 in the front-rear direction. It can be arbitrarily set in the control table so as to satisfy the relationship between the height and the release height, or the relationship between the distance between the high-heat burner 5 and the standard burner 6 in the radial direction and the relationship between the operating height and the release height.

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

Of course, in the gas flow rate control process, a process of weakening the thermal power may be performed based on the operating range. The operating height is the height on the upper limit side of the operating range. Therefore, the height on the lower limit side may be set in the operating range. In this case, in the processing of S7, S9, and S73, the CPU 71 may determine whether or not the measurement height of the optical sensor 40 is within the operating range. Specifically, in the processing of S7 and S73, the CPU 71 determines whether or not there is an optical sensor 40 whose measured height is equal to or greater than the height on the lower limit side of the operating range and equal to or less than the first operating height. Just do it. Similarly, in the process of S9, the CPU 71 may determine whether or not there is an optical sensor 40 whose measured height is equal to or greater than the height on the lower limit side of the operating range and equal to or less than the second operating height.

The above description also applies to the relationship between the release height and the non-release range. Therefore, even if the height less than the release height, that is, the range less than the release height from the optical sensor 40 is set as the non-release range, the range less than the release height from the upper surface of the top plate 3 is substantially. It can be regarded as indicating the non-release range. Then, similarly to the above, in the gas flow rate control process, a process of returning the thermal power to the original state may be performed based on the non-release range. In this case, in the processing of S35 and S75, the CPU 71 may determine whether or not the measurement height of the optical sensor 40 is outside the non-release range. Specifically, in the process of S35, the CPU 71 may determine whether or not there is an optical sensor 40 whose measurement height is higher than the height on the lower limit side of the non-release range and less than the first release height. Similarly, in the process of S75, the CPU 71 may determine whether or not there is an optical sensor 40 whose measurement height is higher than the height on the lower limit side of the non-release range and less than the second release height.

In the above description, the high heat burner 5 and the standard burner 6 are examples of the "burner" of the present invention. The gas supply pipe 27 is an example of the “gas passage” of the present invention. Solenoid valves 61 and 62 are examples of the "valve" of the present invention. The solenoid valve circuit 91 is an example of the "valve operating means" of the present invention. The light emitting element 41 is an example of the "transmitter" of the present invention. The light receiving element 44 is an example of the "receiver" of the present invention. Infrared light is an example of a "detection wave". The optical sensor 40 is an example of a “sensor”. The CPU 71 that performs the processing of S27 and S67 is an example of the "control means" of the present invention. The top plate 3 is an example of the "top plate" of the present invention. The virtual circles D1A and D2A are examples of the "first virtual circle" of the present invention. Optical sensors 4A to 4D and 4F to 4I are examples of the "sensor group" of the present invention. The CPU 71 that performs the processing of S7 and S9 is an example of the "determination means" of the present invention. The virtual circles D1B and D2B are examples of the "second virtual circle" of the present invention. The optical sensors 4J and 4K are examples of the "inner sensor" of the present invention. The CPU 71 that performs the processing of S17 corresponds to the "determination means" of the present invention. The optical sensors 4A and 4C are examples of the "first sensor" of the present invention. The optical sensor 4D is an example of the "second sensor" of the present invention.

1 Stove 3 Top plate 4A-4D, 4F-4K, 40 Optical sensor 5 High-heat burner 6 Standard burner 27 Gas supply tube 40X, 40Y Sensor group 41 Light emitting element 44 Light receiving element 61, 62 Solenoid valve 91 Solenoid valve circuit D1A, D1B , D2A, D2B virtual circle

Claims (5)

With a burner
A valve provided in the gas passage of the burner and changing the gas flow rate through the gas passage,
A valve operating means for operating the valve and
A sensor having a transmitting unit and a receiving unit, and outputting a foreign matter detection result by receiving the detection wave transmitted from the transmitting unit at the receiving unit.
In a gas stove provided with a control means for controlling the drive of the valve operating means to reduce the gas flow rate when a foreign substance is detected by the sensor.
The sensor is
The detection wave is transmitted upward, and when a foreign matter is located above the sensor, information indicating the height of the foreign matter is output as the detection result.
On the top plate of the gas stove, in the area of the first virtual circle that passes through the front part of the top plate centering on the burner and in front of the installation range of the trivet that supports the cooking utensil on the burner, the burner. A group of sensors arranged in a plan view arc shape from one side to the other side in the left-right direction of the burner is configured so as to surround the burner from the front side.
The gas stove is provided with a determination means for determining whether or not the measurement height indicated by the detection result acquired from the sensor is within the operating range within a predetermined height range.
The control means is a gas stove that controls the drive of the valve operating means when the determination means determines that the measured height of the sensor is within the operating range. The sensor is arranged at least on the front side of the burner and on the rear side of the sensor group, and is arranged on a second virtual circle centered on the burner and passing radially inside the first virtual circle. The gas stove according to claim 1, further comprising at least one or more inner sensors. The control means is characterized in that the gas flow rate when reducing based on the detection result of the inner sensor is controlled to a smaller flow rate than the gas flow rate when reducing based on the detection result of the sensor group. The gas stove according to claim 2. When a foreign substance is detected by the inner sensor, a determination means for determining whether or not the foreign substance is a cooking container placed above the burner based on the detection result of the inner sensor is provided.
According to claim 2 or 3, the control means does not drive the valve operating means and maintains the gas flow rate when the determination means determines that the foreign matter is the cooking container. The described gas stove. The sensor group is
The first sensor, which is one of the sensors included in the sensor group,
It is one of the sensors included in the sensor group, and includes a second sensor located behind the first sensor.
1. The height of the upper limit side of the operating range set for the second sensor is higher than the height of the upper limit side of the operating range set for the first sensor. The gas stove according to any one of 4 to 4.

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