JP6840355B2 - Stove - Google Patents

Description

The present invention relates to a stove.

Conventionally, there is known a gas stove that can reduce the thermal power of the burner when the user's hand or arm approaches the burner. For example, there is known a gas stove in which a light-shielding photosensor floodlight and a light receiver are provided on the front left end and the front right end of the top plate, respectively (see, for example, Patent Document 1). The detected light projected from the floodlight crosses the upper surface of the top plate to the left and right and reaches the receiver. When the optical sensor detects that clothes have entered the flammable area by blocking the light from the user's sleeves, the gas stove closes the safety valve to stop the gas and extinguish the burner.

Japanese Patent No. 2886940

However, since the range in which the optical sensor can detect foreign matter is limited, it is necessary to arrange more sensors in order to widen the detection range of the sensor around the burner. If many sensors are arranged and there are several sensors in a close range, when the light emission timings of the projectors of the sensors overlap, a part of the light emitted from the floodlights is received by the receivers of other sensors. This could cause false positives.

An object of the present invention is to provide a stove capable of preventing erroneous detection of a plurality of sensors that detect the presence or absence of foreign matter.

A plurality of the stoves of the invention according to claim 1 are arranged side by side outside the region including the burner, light is output from the light emitting unit, and the reflected light is received by the light receiving unit to detect the presence or absence of foreign matter. Based on the detection results of each of the sensors and the plurality of sensors, when the foreign matter is detected, the thermal power of the burner is controlled to be a predetermined low heat or extinguishing the fire, and the sensor is the foreign matter. Is detected, the light emitting timing of the light emitting portion of the foreign matter detection sensor, which is the sensor that detected the foreign matter, and at least the light emitting timing of the light emitting portion of another sensor adjacent to the foreign matter detection sensor are forcibly forced. Based on the change in the signal output from the light receiving unit of the foreign matter detection sensor before and after the light emission timing is forcibly adjusted by the light emission timing control means and the light emission timing control means, the foreign matter detection sensor performs the above. When the determination means for determining the correctness of the foreign matter detection result and the foreign matter detection determination means determine that the foreign matter detection result by the foreign matter detection sensor is correct, the foreign matter detection result of the foreign matter detection sensor is determined. It is characterized by including a confirming means and an invalidation means for invalidating the detection result of the foreign matter by the foreign matter detection sensor when the determination means determines that the detection result of the foreign matter by the foreign matter detection sensor is an error. And.

In the stove of the invention according to claim 2, in addition to the configuration according to claim 1, the determination means includes a first signal which is a signal from the light receiving unit when the foreign matter detection sensor detects the foreign matter. The light emission timing control means compares the second signal, which is a signal from the light receiving portion of the foreign matter detection sensor, when the light emission timing is forcibly adjusted, and the difference between the first signal and the second signal. Is less than the threshold value, it is determined that the foreign matter detection result by the foreign matter detection sensor is correct, and when the difference between the first signal and the second signal is greater than or equal to the threshold value, the foreign matter detection sensor determines that the foreign matter is detected. It is advisable to determine that the detection result of the foreign matter is an error.

In addition to the configuration according to claim 1 or 2, the stove of the invention according to claim 3 may be an infrared sensor.

According to the stove of the invention according to claim 1, when the sensor detects a foreign substance, at least another sensor adjacent to the foreign substance detection sensor emits light with respect to the light emission timing of the foreign substance detection sensor which is the sensor that detected the foreign substance. Forcibly adjust the timing. As a result, the light output from the light emitting portion of the other sensor and reflected by the foreign matter is incident on the light receiving portion of the foreign matter detection sensor, so that the foreign matter detection sensor can easily detect the foreign matter erroneously. If the foreign matter detection sensor accurately detects foreign matter, it is not affected by other sensors. Therefore, before and after adjusting the light emission timing, the correctness of the foreign matter detection result is determined based on the change of the signal output from the light receiving unit of the foreign matter detection sensor. If the foreign matter detection result is correct, the foreign matter detection result is confirmed, and if it is incorrect, the foreign matter detection result is invalidated. As a result, the optical sensor that detects foreign matter determines whether or not it is a false detection due to the influence of other sensors, and in the case of a false detection, the detection result is invalidated, so that false detection due to mutual interference between the sensors is performed. Can be prevented.

According to the stove of the invention according to claim 2, in addition to the effect according to claim 1, when the foreign matter detection sensor accurately detects the foreign matter, it is output from the light emitting part of another sensor and reflected by the foreign matter. Even if the light is received by the light receiving portion of the foreign matter detection sensor, it is not affected by the light. Therefore, the determination means can determine that the detection result of the sensor is correct if the change in the signal output from the light receiving unit of the foreign matter detection sensor before and after forcibly adjusting the light emission timing is smaller than the threshold value. On the other hand, if the change in the output signal is equal to or greater than the threshold value, the detection result of the sensor can be determined to be an error. As a result, the correctness of the detection result of the foreign matter detection sensor can be easily determined.

According to the stove of the invention according to claim 3, in addition to the effect according to claim 1 or 2, the effect of claim 1 or 2 is obtained in a stove equipped with a plurality of infrared sensors including a light emitting unit and a light receiving unit. be able to.

In the present invention, some of the invention-specific matters described in claims 1 to 3 may be arbitrarily combined.

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 timing chart which shows the operation of an optical sensor 40. It is a figure which shows the structure of the thermal power control mechanism 60 provided in the gas supply pipe 27. This is a block showing the electrical configuration of the stove 1. It is a figure which shows the state which the reflected light R6 which emitted from the light emitting element 41 of an optical sensor 4A and reflected by the foreign substance B4 is received by the light receiving element 44 of an optical sensor 4B. It is a flowchart of a main control process. It is a flowchart of a sensor control process. It is a timing chart of a sensor 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 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 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 gridiron, etc. to the outside of the grill.

In the center of the front surface of the housing 2, in the area on the right side of the grill door 14, ignition buttons 15, 16, thermal power adjusting levers 18, 19, an operation panel 25, and the like are provided. The ignition button 15 is provided adjacent to the right side of the grill door 14, and 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 a rotation operation in a substantially horizontal direction. The operation panel 25 is provided so as to be rotatable in the front-rear direction below the ignition buttons 15 and 16. The operation panel 25 includes a plurality of buttons for receiving inputs of various operations, an LED for notifying according to various operations, and the like.

On the other hand, in the center of the front surface of the housing 2, an ignition button 17, a thermal power adjusting lever 20, and the like are provided in the area on the left side of the grill door 14. The ignition button 17 is provided adjacent to the left side of the grill door 14, and when pressed, the 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 sensor device 4. The sensor device 4 includes a plurality of (11 in this embodiment) optical sensors 4A to 4K. The optical sensors 4A to 4K have the same configuration. In the following description, when the optical sensors 4A to 4K are generally described, they are referred to as an optical sensor 40. The optical sensor 40 is a known reflection type ranging sensor. The optical sensors 4A to 4K are provided inside the housing 2 and are arranged outside the high-heat burner 5 and the standard burner 6. The optical sensors 4A to 4K are located in the opening 2A of the housing 2 in a plan view. When the top plate 3 is fixed to the housing 2, the optical sensors 4A to 4K are located directly below the top plate 3. The optical sensors 4A to 4K output a detection wave from the window portion of the glass plate 11 toward the upper side of the top plate 3 to detect foreign matter approaching the high heat burner 5 and the standard burner 6. The "outside" of the high-heat burner 5 and the standard burner 6 in the present invention means that the high-heat burner 5 and the standard burner 6 intersect in the vertical direction such as front, rear, left, right, and surroundings. A part located outside the high heat burner 5 and the standard burner 6.

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

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

The optical sensors 4F to 4I are used to control the flow rate of gas supplied to the standard burner 6. The optical sensors 4F to 4I are located at positions from diagonally forward right to diagonally forward left of the standard burner 6 in a plan view, and are approximately evenly spaced along a gentle arc-shaped virtual line D2 along the circumferential direction of the standard burner 6. line up. The optical sensors 4F to 4I are arranged outside the outer circumference of the frying pan in a plan view when, for example, a frying pan having a diameter of 28 cm is placed on the trivet 8 of the standard burner 6.

The optical sensor 4E is used to control the gas flow rate supplied to the high-heat burner 5 and the standard burner 6. The optical sensor 4E is arranged between the optical sensor 4D and the optical sensor 4F at substantially the center in the left-right direction.

As described above, the optical sensors 4A to 4D are arranged along the virtual line D1, and the optical sensors 4F to 4I are arranged along the virtual line D2. The term "along" in the present embodiment is not necessarily limited to the state in which the optical sensors 4A to 4I are arranged on one virtual line drawn in a predetermined direction, and the line is used as a reference while allowing misalignment. The state of being placed. Further, the virtual line is not necessarily limited to an arc-shaped line, and may be a straight line or a wavy line. As described above, the optical sensors 4A to 4I are partially arranged along the virtual lines D1 and D2, respectively, but as a whole, they are laterally arranged in a predetermined detection area in front of the high-heat burner 5 and the standard burner 6. Arranged alongside to form a line.

The optical sensor 4J is used to control the flow rate of gas supplied to the high-heat burner 5. The optical sensor 4J is arranged obliquely to the left of the high-heat burner 5 and substantially behind the optical sensor 4D. 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 a plan view. In other words, the optical sensors 4A to 4D are located in front of the optical sensor 4J in the front-rear direction with respect to the high-heat burner 5, and are located outside the optical sensor 4J in the radial direction of the high-heat burner 5.

The optical sensor 4K is used to control the flow rate of gas supplied to the standard burner 6. The optical sensor 4K is arranged diagonally to the right of the standard burner 6 and substantially behind the optical sensor 4F. 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 a plan view. In other words, the optical sensors 4F to 4I are located in front of the optical sensor 4K in the front-rear direction with respect to the standard burner 6 and outside the optical sensor 4K in the radial direction of the standard burner 6.

The optical sensor 4J and the optical sensor 4K are provided at substantially the same position in the front-rear direction. The optical sensors 4J and 4K have the high thermal power burner 5 and the standard burner in order to reliably detect the approach of the foreign matter when the foreign matter approaches the high heat burner 5 and the standard burner 6 more than the area where the optical sensors 4A to 4I are lined up. It is provided between 6 and the area where the optical sensors 4A to 4I are lined up.

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. In this way, by extracting the change in the current value synchronized with the emission timing of the infrared light, the influence of the disturbance can be reduced. 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.

Here, the operation of the optical sensor 40 will be specifically described. As shown in FIG. 5, for example, one (1 cycle) distance measurement period from t to t1 is defined as the A period. The drive circuit sets the B period, the C period, and the D period during the A period. The B period is the period before infrared light emission, the C period is the infrared light emission period, and the D period is the post-infrared light emission period. The B period is a preparation period for driving the light emitting element 41 to emit infrared light. The C period is a period in which infrared light is emitted from the light emitting element 41, and is emitted, for example, 6 times in a pulse period. The number of times of emission is not limited to 6 times. During the D period, the signal processing circuit acquires the current output obtained by the light receiving element 44 sensing the light, extracts the current value change synchronized with the emission timing of the infrared light, and performs arithmetic processing to obtain the average value. The period. The optical sensor 40 repeatedly executes this A period while the power is on. The signal processing circuit outputs the result (measured value) of the arithmetic processing in the D period as a detection signal described later in the E period set in the next A period.

The optical sensor 40 having the above configuration measures the distance to a foreign object during the A period as follows, and indicates a voltage value (hereinafter, referred to as “measured voltage value”) according to the distance during the E period. Is output. As shown in FIG. 4, 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 infrared light emitted from the light emitting element 41 is among the reflected light reflected by the foreign matter B1. The reflected light reflected at an angle toward the light receiving element 44 is shown by the reflected light R1 in FIG. 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 FIG. Medium, reflected light R2. The condensing region F2 in which the reflected light R2 is refracted by the condensing lens 46 and condensed on the light receiving surface of the light receiving element 44 collects infrared light with respect to the emission position F0 emitted from the light emitting element 41 in the stretching direction. It is located farther than the optical region F1. The light receiving element 44 has a resistance value different depending on the light collecting region on the light receiving surface, and outputs a current having a magnitude corresponding to the resistance value at the time of distance measurement. Therefore, the stove 1 can obtain the measured voltage value indicated by the detection signal output by the optical sensor 40 and perform an operation based on the triangular ranging method to obtain the distance between the optical sensor 40 and the foreign matter.

With reference to FIG. 6, the thermal power control mechanism 60 of the high thermal power burner 5 will be described below. 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 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 FIG. 6, 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 as "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. 7) of the control circuit 70, such as the detection result of the pot bottom temperature by the thermistor 5B, the detection result of foreign matter by the optical sensors 4A to 4E, 4J, the time after ignition, etc. It is controlled according to each. Similarly, the operation of the solenoid valve 63 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. 7. 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 circuit 70 includes a power supply circuit 81, a switch input circuit 82, a thermistor input circuit 83, a thermocouple input circuit 84, an igniter circuit 85, a sensor input circuit 86, 87, a buzzer circuit 88, a safety valve circuit 90, and an electromagnetic valve circuit 91. The operation panel 25 and the like are connected to each other. The power supply circuit 81 steps down the alternating current (for example, 100V) supplied from the power supply 23 to a direct current (for example, 5V), rectifies it, and supplies electric power to various circuits. In FIG. 7, 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 FIG. 7, 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 FIG. 7, 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 FIG. 7, 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. In FIG. 7, the igniter is represented by "IG". Further, in FIG. 7, the thermistor, thermocouple, and igniter provided in the grill burner are omitted.

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

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

When the optical sensor 40 detects 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. When the foreign matter is located straight in front of the light emitting element 41 in the emission direction, the optical sensor 40 outputs a detection signal according to an accurate distance from the foreign matter. On the other hand, a process is performed in which a threshold value is set for the magnitude of the detection signal of the optical sensor 40 and it is determined whether or not the distance to the foreign matter is equal to or less than a predetermined distance.

With reference to FIG. 8, when a plurality of optical sensors 40 are arranged in a close range, the reason why the detected value of the distance different from the actual one is explained due to the overlapping of the emission timings of the infrared light. Here, the optical sensors 4A and 4B (see FIGS. 3 and 8) arranged at positions adjacent to each other will be described as an example. For example, the foreign matter B5 located directly above the optical sensor 4B is irradiated with infrared light emitted from the light emitting element 41 of the optical sensor 4B. The light receiving element 44 of the optical sensor 4B detects the position of the reflected light R5 reflected by the foreign matter B5 (the center of the infrared light intensity), and determines the distance to the foreign matter B5.

The infrared light emitted from each of the light emitting elements 41 of the optical sensors 4A and 4B is irradiated upward with a certain spread. An optical sensor 4A is arranged to the right of the optical sensor 4B. The foreign matter B4 above the optical sensor 4A is irradiated with infrared light emitted from the light emitting element 41 of the optical sensor 4A. The reflected light R4 reflected by the foreign matter B4 is incident on the light receiving element 44 of the optical sensor 4A. The light receiving element 44 detects the position of the reflected light R4 and determines the distance to the foreign matter B4.

Here, due to the spread of the infrared light emitted from the light emitting element 41 of the optical sensor 4A, the reflected light R6 reflected at another position of the foreign matter B4 may be incident on the light receiving element 44 of the optical sensor 4B. There is. The foreign matter B4 is arranged farther than the foreign matter B5 with respect to the optical sensor 4B, but the reflected light R6 reflected at another position of the foreign matter B4 is incident at almost the same incident angle as the reflected light R5. ing. At this time, the position of the condensing region focused on the light receiving surface of the light receiving element 44 in the optical sensor 4B of the reflected light R6 is in the stretching direction rather than the position of the condensing region corresponding to the actual distance to the foreign matter B4. , The position is far from the light emitting element 41. At this time, the distance of the foreign matter B4 detected by the light receiving element 44 of the optical sensor 4B is closer than the actual distance of the foreign matter B4, and there is a possibility that the distance is erroneously detected as a distance close to the foreign matter B5. Such a phenomenon is due to the fact that the light emitting timings of the light emitting elements 41 of the plurality of optical sensors 40 installed within a range close to each other overlap.

Therefore, in the present embodiment, when a plurality of optical sensors 40 are arranged in a close range to the stove 1, when the optical sensor 40 detects a foreign substance, at least the light emission timing of the optical sensor 40 that detects the foreign substance is relative to the light emission timing. The light emission timings of other adjacent optical sensors 40 are forcibly adjusted. As a result, a state that is easily affected by the other optical sensor 40 is forcibly created. The optical sensor 40 that actually accurately detects the distance of a foreign object is not affected by other optical sensors 40. Therefore, before and after adjusting the light emission timing, the range of change in the measurement distance of the optical sensor that detects foreign matter is confirmed, and the measurement distance is determined after confirming that the detection is not erroneous due to the influence of the other optical sensor 40. .. As a result, in the optical sensor that detects foreign matter, erroneous detection due to the influence of the other optical sensor 40 can be prevented.

The main control process will be described with reference to FIG. For example, when the ignition button 17 or 18 is pressed by the user and either the high heat burner 5 or the standard burner 6 is ignited, the CPU 71 reads the main control program stored in the ROM 72 and executes this process.

The CPU 71 turns on the power of the optical sensor 40 corresponding to the ignited burner (S1). For example, when the ignition button 15 is pressed and the high-heat burner 5 is ignited, the CPU 71 turns on the power of the optical sensors 4A to 4E, 4J corresponding to the high-heat burner 5. The power-on optical sensors 4A to 4E, 4J repeatedly execute the one-cycle operation shown in FIG. 5 described above. Since the power-on timings of the optical sensors 4A to 4E and 4J in S1 are the same, the start timings of the respective A periods are the same, but they gradually shift according to individual differences as the operation is repeated. It is common.

The CPU 71 executes the sensor control process (S2). In the sensor control process, as will be described later, when a certain optical sensor 40 detects a foreign substance among the optical sensors 4A to 4E and 4J whose power is turned on, the CPU 71 detects the foreign substance. The light emission timing of other optical sensors 40 other than the optical sensor 40 that has detected the foreign matter is forcibly adjusted to the light emission timing of. Then, the CPU 71 confirms the range of change in the measurement distance of the optical sensor 40 that has detected the foreign matter, confirms that the detection is not an erroneous detection due to the influence of another optical sensor 40, and then determines the measurement distance.

As a result of the sensor control process of S2, if there is no optical sensor 40 among the optical sensors 4A to 4E and 4J indicating that the measurement distance is equal to or less than the working distance (S3: NO), the CPU 71 sets the process to S2. return. The operating distance is a reference distance when determining whether or not to control the closing of the solenoid valves 61 and 62. 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 invades within the detection range corresponding to the working distance, the measured voltage value of the optical sensor 40 rises to indicate the working voltage value or higher. As a result of the sensor control process, if there is at least one optical sensor 40 among the optical sensors 4A to 4E and 4J that indicates that the measured voltage value is equal to or greater than the operating voltage value and the measured distance is equal to or less than the operating distance (S3: YES). The CPU 71 advances the process to S4. The CPU 71 issues an instruction to the solenoid valve circuit 91 and controls to close the solenoid valves 61 and 62 (S4). The gas flow rate flowing through the thermal power adjusting mechanism 30 by the thermal power control mechanism 60 is reduced to the third flow rate. The firepower of the high firepower burner 5 automatically becomes low firepower. The CPU 71 issues an instruction to the buzzer circuit 88, drives the piezoelectric buzzer 77, and notifies the detection of foreign matter (S5). Further, the CPU 71 lights a predetermined LED on the operation panel 25 to notify the detection of foreign matter.

The CPU 71 turns on the power of the optical sensor 40, which has been turned off, again in the sensor control process described later in S2 (S6). The CPU 71 acquires the detection signals of the optical sensors 4A to 4E and 4J corresponding to the ignited high-heat burner 5, respectively (S7). The CPU 71 compares the acquired measured voltage values with the release voltage values according to the release distances, respectively. The release distance is preset as a distance for controlling the reduction of the gas flow rate, and is, for example, 15 cm. Therefore, when there is a foreign substance in the detection range corresponding to the release distance and the measurement distance is less than or equal to the release distance, the measured voltage value indicates the release voltage value or more. If any one of the optical sensors 4A to 4E and 4J has an optical sensor 40 indicating that the measurement distance is equal to or less than the release distance (S8: YES), the CPU 71 returns the process to S7. 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 detection range corresponding to the release distance, the measured voltage value of the optical sensor 40 drops, indicating that it is less than the release voltage value. When all the measured voltage values of the optical sensors 4A to 4E and 4J are less than the release voltage value and there is no optical sensor 40 indicating that the measurement distance is less than or equal to the working distance (S8: NO), the CPU 71 advances the process to S9. .. The CPU 71 issues an instruction to the solenoid valve circuit 91 and controls to open the solenoid valves 61 and 62 (S9). The gas flow rate flowing through the thermal power adjusting mechanism 30 by the thermal power control mechanism 60 is increased to the first flow rate. High heat power The firepower of Burner 5 automatically becomes high heat power. The CPU 71 issues an instruction to the buzzer circuit 88, stops driving the piezoelectric buzzer 77, and cancels the notification of foreign matter detection (S10). 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 S2.

The CPU 71 executes the same main 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 4E to 4I and 4K. When the high heat burner 5 and the standard burner 6 are extinguished, the CPU 71 ends the execution of the main control process corresponding to the extinguished burner.

The sensor control process will be specifically described with reference to FIGS. 10 and 11. In this process, the parameter k is used. The parameter k is the number of times that the measurement distance is determined to be equal to or less than the working distance for each of the power-on optical sensors 4A to 4E and 4J, and is stored in, for example, the RAM 73. In the sensor control process shown in FIG. 10, for convenience of explanation, any optical sensor among the optical sensors 4A to 4E and 4J is set as the first sensor, and the operation when the first sensor detects a foreign substance will be mainly described.

The CPU 71 initializes the parameter k stored in the RAM 73 to 0 (S21). The optical sensors 4A to 4E and 4J, whose power is turned on in S1, each repeatedly execute the operation of one cycle shown in FIG. The first sensor, which is an arbitrary optical sensor among the optical sensors 4A to 4E and 4J, starts the first A period at t10. In the first sensor, t10 to t12 are the first A period, t12 to t14 are the second A period, t14 to t16 are the third A period, t18 to t19 are the fourth A period, and t19 to t20 are the fourth A period. The fifth A period, t20 to t21, is the sixth A period.

On the other hand, the optical sensor 40 other than the first sensor starts the first A period at t11, for example, after the first sensor. In the other optical sensors 40, t11 to t13 are the first A period, t13 to t15 are the second A period, t15 to t17 are the third A period, and t18 to t19 are the fourth A period. t19 to t20 is the fifth A period, and t20 to t21 is the sixth A period. Since FIG. 11 is a timing chart during the operation of the first sensor and the other optical sensor 40 whose power was turned on by the process of S1 of FIG. 10, the first sensor and the other optical sensor 40 The start timing of each A period is off.

The CPU 71 determines whether or not the B period of the first sensor has expired (S22). In period B, preparations are made for driving the light emitting element 41 to emit infrared light. Until the end of the B period (S22: NO), the CPU 71 returns to S22 and waits. When the B period ends (S22: YES), the CPU 71 determines whether or not the C period has ended (S23). In the C period, infrared light is emitted from the light emitting element 41 in a pulse period, for example, six times. The reflected light reflected by a foreign substance such as clothes is received by the light receiving element 44 of the first sensor.

Until the end of the C period (S23: NO), the CPU 71 returns to S23 and waits. When the C period ends (S23: YES), since the infrared light emission has ended, the CPU 71 determines whether or not the D period has ended (S24). In the D period, the current output obtained by sensing the light by the light receiving element 44 is acquired, the change in the current value synchronized with the emission timing of the infrared light is extracted, and the arithmetic processing for obtaining the average value of the six measured values is performed. Will be done. Until the end of the D period (S24: NO), the CPU 71 returns to S24 and waits. It should be noted that the determination as to whether or not each period has ended may be made by measuring the time using, for example, a timer or the like. Since the lengths of the A period and the B to E periods in which the optical sensor 40 operates are predetermined, has each period ended by measuring the time from when the power of the first sensor is turned on? It is possible to judge whether or not.

When the D period ends at t12 (S24: YES), the second A period starts in the first sensor, and the CPU 71 detects it during the E period set after a predetermined period elapses after the A period starts. It is determined whether or not the signal has been received (S25). In the E period, the result (measurement distance) of the arithmetic processing in the D period is output as a detection signal. Until the detection signal is received from the first sensor (S25: NO), the CPU 71 returns to S25 and waits.

When the detection signal is received (S25: YES), the CPU 71 determines whether or not the measurement distance corresponding to the received detection signal is equal to or less than the working distance (S26). Here, the CPU 71 compares the measured voltage value indicated by the detection signal with the operating voltage value according to the operating distance, respectively. The working distance is preset as a distance for controlling to reduce the gas flow rate, and is, for example, 10 cm. 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 detection range corresponding to the working distance and the measured distance is longer than the working distance, the measured voltage value indicates less than the working voltage value. If the measurement distance is not less than or equal to the working distance (S26: NO), no foreign matter has been detected by the first sensor, so the CPU 31 ends this process and proceeds to S3 in FIG.

At t12, the second A period of the first sensor is started, the B period and the C period end (S22: YES, S23: YES), and the D period ends at t14 (S24: YES). The third A period starts in the first sensor, and the CPU 71 receives a detection signal during the set E period after the elapse of a predetermined period after the start of the A period (S25: YES). When the measurement distance is equal to or less than the working distance (S26: YES), it is highly possible that a foreign substance has been detected, so the CPU 71 adds 1 to the parameter k stored in the RAM 73 (S27). The CPU 71 determines whether or not k is 3 or more (S28). At this point, k = 1 (S28: NO), and the number of samplings is not sufficient, so the CPU 71 returns to S22.

The CPU 71 confirms the end of the B period, the C period, and the D period in the third A period of the first sensor started at t14 (S22: YES, S23: YES, S24: YES). When the third A period (D period) ends at t16, the CPU 71 receives the detection signal again during the E period (S25: YES). When the measurement distance is again equal to or less than the working distance (S26: YES), the CPU 71 further adds 1 to the parameter k stored in the RAM 73 (S27). Since k = 2 at this point (S28: NO), the CPU 71 has detected the foreign matter twice in succession. The CPU 71 returns to S22.

The CPU 71 confirms the end of the B period, the C period, and the D period in the fourth A period of the first sensor started at t16 (S22: YES, S23: YES, S24: YES). When the fourth A period (D period) ends at t16, the CPU 71 again receives the detection signal from the first sensor during the E period (S25: YES). When the measurement distance is again equal to or less than the working distance (S26: YES), the CPU 71 further adds 1 to the parameter k stored in the RAM 73 (S27). Since k = 3 at this point (S28: YES), the CPU 71 has detected the foreign matter three times in succession, which is a sufficient number of sampling times.

Therefore, the CPU 71 determines whether or not the measurement distance detected three times in a row in the past satisfies the stability condition (S29). The stable condition is, for example, a condition in which the difference between the maximum value and the minimum value of the three measurement distances determined to be equal to or less than the working distance is within a predetermined error. If the difference between the maximum value and the minimum value of the measurement distance detected three times in a row in the past exceeds the range of the predetermined error, the stability condition is not satisfied (S29: NO), and the detection result is unstable. The CPU 71 returns to S21, initializes k to zero, receives the detection signal from the first sensor again, and repeats the process.

On the other hand, when the measurement distance detected three times in the past satisfies the stable condition (S29: YES), the state where the measurement distance is equal to or less than the working distance is continuously detected in the three times A period, and foreign matter is detected. Since the detected state continues for a predetermined time, it is highly possible that the first sensor has detected the foreign matter. However, as described above, there is a possibility that the light emitting element 41 of another sensor within the range close to the first sensor is affected by the infrared light emitted and erroneously detected. Therefore, in order to confirm whether the measurement distance detected by the first sensor three times in a row in the past is not an erroneous detection, the CPU 71 is t17, and the first sensor detecting a foreign object (corresponding to the "foreign object detection sensor" of the present invention). And, the power is temporarily turned off for all the optical sensors 4A to 4E and 4J of the other optical sensors 40 (corresponding to the "determination sensor" of the present invention) (S30). Therefore, the energization of the optical sensors 4A to 4E and 4J is turned off.

The CPU 71 simultaneously turns on the power of all the optical sensors 4A to 4E and 4J whose energization is turned off at t18 (S31). As a result, all the A period start timings of the optical sensors 4A to 4E and 4J are aligned. The first sensor and the other sensors 40 simultaneously start the fourth A period at t18. When the B period of the first sensor ends (S32: YES), the CPU 71 determines whether or not the C period has ended (S33). Since the light emission timing of the first sensor during the C period and the light emission timing of the other sensor 40 during the C period overlap with each other, the state of being easily affected by the other optical sensor 40 during the C period of the first sensor can be determined. Can be forcibly created. In the C period, infrared light is emitted from the light emitting element 41 in a pulse period, for example, six times. The reflected light reflected by a foreign substance such as clothes is received by the light receiving element 44 of the first sensor. At this time, infrared light is also emitted from the optical sensor 40 other than the first sensor. Therefore, in addition to the reflected light emitted from the light emitting element 41 of the first sensor and reflected by the foreign matter, the light receiving element 44 of the first sensor is reflected by the light emitting element 41 of the other sensor 40 and reflected by the foreign matter. There is a high possibility that light is also being received. The CPU 71 confirms the end of the C period and the D period (S33: YES, S34: YES). Since the fourth A period (D period) ends at t19 and the fifth A period starts, the CPU 71 receives the detection signal again during the E period (S35: YES).

The CPU 71 calculates the difference between the measurement distance corresponding to the detection signal received this time and the average value of the measurement distances of the past three times before that, and determines whether or not the difference is less than the threshold value (S36). When the difference is less than the threshold value (S36: YES), the range of change between the current measurement distance and the previous three measurement distances is small. As described above, even in a state where it is easily affected by the other optical sensor 40, if the first sensor actually detects the distance of the foreign matter accurately, it is not affected by the other optical sensor 40. .. Therefore, if the range of change is less than the threshold value and small, there is a high possibility that the first sensor actually detects the distance of the foreign matter accurately, so that the CPU 71 does not erroneously detect the distance measured three times in the past. Can be judged. Therefore, the CPU 71 determines the measurement distance (mean value) detected three times in the past (S37) and stores it in the RAM 73 as the measurement distance of the first sensor. The CPU 71 ends this process and proceeds to S3 in FIG. In this case, since the first sensor is an optical sensor indicating that the measurement distance is equal to or less than the working distance (S3: YES), the CPU 71 issues an instruction to the solenoid valve circuit 91 and controls to close the solenoid valves 61 and 62 as described above. (S4). As a result, the gas flow rate is reduced to the third flow rate, and the thermal power of the high thermal power burner 5 automatically becomes low thermal power.

On the other hand, when the difference between the current measurement distance and the average value of the previous three measurement distances is equal to or greater than the threshold value (S36: NO), the current measurement distance and the previous three measurement distances The range of change is large. If the range of change is greater than or equal to the threshold value, there is a high possibility that the first sensor has erroneously detected the distance of the foreign matter, so that the CPU 71 can determine that the past three measurement distances are erroneous detections. Therefore, the CPU 71 resets the measurement distance detected three times in the past and the measurement distance this time to invalidate it (S38). The CPU 71 ends this process and proceeds to S3 in FIG. In this case, at least the first sensor is not an optical sensor indicating that the measurement distance is equal to or less than the working distance. If the measurement distance of the other optical sensor 40 is not less than or equal to the working distance (S3: NO), the CPU 71 returns to S2 and repeatedly executes the sensor control process. When the cooking is completed and the ignition button 15 is pressed again by the user to extinguish the high heat burner 5, the CPU 71 forcibly ends the main control process shown in FIG.

In the above main control process, when there is an optical sensor 40 that detects a foreign object, the power of all the optical sensors 40 including the first sensor, which is the optical sensor 40 that detects the foreign substance, is temporarily turned off and then turned on again. As a result, the light emission timings of the first sensor and the other optical sensors 40 are matched to forcibly create a state in which the first sensor and the other optical sensors 40 are susceptible to the influence of other optical sensors 40 within a range close to the first sensor. At least, the light emission timing of the first sensor may be matched with the light emission timing of the first sensor and another optical sensor 40 adjacent to the first sensor. Therefore, the power supply of the first sensor and the other optical sensors 40 adjacent to the first sensor may be once turned off and then turned on again. Further, the power of each of the one or a plurality of other optical sensors 40 within a range close to the first sensor may be once turned off and then turned on again.

In the above description, the light emitting element 41 is an example of the "light emitting unit" of the present invention. The light receiving element 44 is an example of the "light receiving unit" of the present invention. The CPU 71 that executes the main control process of FIG. 9 is an example of the "thermal power control means" of the present invention. The CPU 71 that executes the processes of S30 and S31 of FIG. 11 is an example of the "light emission timing control means" of the present invention. The CPU 71 that executes the process of S36 is an example of the "determination means" of the present invention. The CPU 71 that executes the process of S37 is an example of the "determining means" of the present invention. The CPU 71 that executes the process of S38 is an example of the "invalidation means" of the present invention.

As described above, the stove 1 of the present embodiment includes the sensor device 4. The sensor device 4 includes a plurality of optical sensors 4A to 4K. The optical sensors 4A to 4K are arranged side by side on the outer side of the high heat burner 5 or the standard burner 6, light is output from the light emitting element 41, and the reflected light is received by the light receiving element 44, whereby the high heat burner 5 Alternatively, the presence or absence of foreign matter such as clothing that invades above the standard burner 6 is detected. The stove 1 controls the thermal power of the high thermal power burner 5 or the standard burner 6 to a predetermined low thermal power when a foreign substance is detected based on the detection results of the optical sensors 4A to 4K. When any of the optical sensors 40 of the optical sensors 4A to 4K detects a foreign substance in such a stove 1, after the power of the optical sensors 4A to 4K including the first sensor that detects the foreign substance is once turned off. By turning on the power at the same time, the light emission timings of all the optical sensors 4A to 4K are forcibly adjusted. As a result, the reflected light output from the light emitting element 41 of the other sensor 40 and reflected by the foreign matter is incident on the light receiving element 44 of the first sensor, so that the first sensor can easily detect the foreign matter easily. it can. When the first sensor accurately detects the foreign matter, it is not affected by the other optical sensors 40. Therefore, before and after adjusting the light emission timing, the correctness of the foreign matter detection is determined based on the change of the signal output from the light receiving element 44 of the first sensor. If the foreign matter detection result is correct, the foreign matter detection result is confirmed, and if it is incorrect, the foreign matter detection result is invalidated. That is, since the measurement distance is determined after confirming the range of change in the measurement distance of the optical sensor 40 and confirming that it is not an erroneous detection due to the influence of the other optical sensor 40, an error due to the influence of the other optical sensor 40 is determined. Detection can be prevented.

The present invention is not limited to the above embodiment, and various modifications can be made. 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 4I are arranged in the left-right direction, but the arrangement direction is not limited to the left-right direction, and may be a front-rear direction, or may be, for example, an oblique direction connecting the front right and the rear left. Alternatively, a support column may be erected on the rear side of the stove 1 and arranged vertically along the support column. Further, the optical sensors 4A to 4I may be arranged side by side along the inclination direction connecting the upper left side and the lower right side, for example. Further, the optical sensors 4A to 4I do not necessarily have to be linear or arcuate, and may be arranged side by side along, for example, a wavy undulating direction. Further, unlike the optical sensors 4J and 4K, not all the optical sensors 40 need to be arranged side by side.

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

In the process of S4 of the main control process shown in FIG. 9, the solenoid valves 61 and 62 are closed, the gas flow rate is controlled to the third flow rate, and the high heat burner 5 is controlled to the weak heat. One of 62 may be closed to control the medium heat power, or the high heat power burner 5 may be extinguished. Further, the high heat burner 5 may be controlled to either medium heat or low heat depending on the height at which the optical sensors 4A to 4K detect foreign matter.

In the process of S30 of the sensor control process shown in FIG. 10, all the optical sensors 40 including the first sensor that detected the foreign matter are turned off, but for example, the foreign matter detection result of the first sensor is likely to be affected. The power supply of only the optical sensor 40 may be turned off, or the power supply of a specific optical sensor 40 within a predetermined range from the first sensor may be turned off. The optical sensor 40 that easily affects the foreign matter detection result of the first sensor is, for example, one or a plurality of other optical sensors 40 adjacent to the first sensor that has detected the foreign matter. The specific optical sensor 40 within a predetermined range from the first sensor is, for example, highly likely that the reflected light emitted from the light emitting element 41 and reflected by the foreign matter is incident on the light receiving element 44 of the first sensor. The optical sensor 40.

In the above embodiment, in the sensor control process of FIG. 10, it is determined three times in a row that the measurement distance is equal to or less than the working distance, and when the stability condition is satisfied, the measurement distance of the first sensor is determined, but the measurement distance is determined. The number of times that is continuously determined to be less than or equal to the working distance is not limited to three, and can be freely changed.

In the process of S36 of FIG. 10 of the above embodiment, it is determined whether or not the difference between the current measurement distance and the measurement distance of the previous three times is less than the threshold value, but it is determined whether or not it is below the threshold value. You may.

1 Stove 5 High heat burner 6 Standard burner 4A-4K Optical sensor 41 Light emitting element 44 Light receiving element 71 CPU

Claims (3)

A plurality of sensors that are arranged side by side outside the area including the burner, light is output from the light emitting part, and the reflected light is received by the light receiving part to detect the presence or absence of foreign matter.
Based on the detection results of each of the plurality of sensors, when the foreign matter is detected, the thermal power of the burner is controlled to be a predetermined low thermal power or extinguishing, and a thermal power control means.
When the sensor detects the foreign matter, the light emitting timing of the light emitting portion of the foreign matter detection sensor, which is the sensor that detected the foreign matter, and the light emitting timing of the light emitting portion of at least another sensor adjacent to the foreign matter detection sensor. Light emission timing control means that forcibly matches with
Based on the change in the signal output from the light receiving portion of the foreign matter detection sensor before and after the light emission timing is forcibly adjusted by the light emission timing control means, the correctness of the foreign matter detection result by the foreign matter detection sensor is determined. Judgment means for judgment and
When the determination means determines that the foreign matter detection result by the foreign matter detection sensor is correct, the determination means for determining the foreign matter detection result by the foreign matter detection sensor.
The stove is provided with an invalidation means for invalidating the detection result of the foreign matter by the foreign matter detection sensor when the determination means determines that the detection result of the foreign matter by the foreign matter detection sensor is erroneous. The determination means
The light reception of the foreign matter detection sensor when the light emission timing is forcibly matched with the first signal which is a signal from the light receiving unit when the foreign matter detection sensor detects the foreign matter. The second signal, which is a signal from the unit, is compared, and when the difference between the first signal and the second signal is less than the threshold value, it is determined that the foreign matter detection result by the foreign matter detection sensor is correct.
The stove according to claim 1, wherein when the difference between the first signal and the second signal is equal to or greater than the threshold value, the detection result of the foreign matter by the foreign matter detection sensor is determined to be an error. The stove according to claim 1 or 2, wherein the sensor is an infrared sensor.

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