JP2020159564A - Stove - Google Patents

Abstract

To provide a stove that enables a handle not to be detected when foreign matter detected by a sensor is a handle of a cooking container.SOLUTION: A stove includes a plurality of sensors on the front side of a stove burner. The sensors receive reflection light that is emitted by a light emitting part and reflected by foreign matter at a light receiving part. Based on the reflection light received by the light receiving part, a CPU of the stove determines whether or not foreign matter is detected within a height range of a determination value A or lower (S13). When foreign matter is detected in the determination value A or lower (YES in S13), the CPU reduces fire power of the stove burner to the minimum fire power (S14). When a predetermined time elapses with the height of the foreign matter being within a constant height (YES in S16, and YES in S17) after the fire power is reduced, the CPU determines the foreign matter to be a handle (S18), and changes only a determination value of the sensor that has detected the handle to a determination value B that is lower than the height of the handle (S19). Thereby, it is possible that the stove does not detect the handle as foreign matter.SELECTED DRAWING: Figure 7

Description

The present invention relates to a stove.

Conventionally, a gas stove capable of reducing the thermal power of the stove burner when a plurality of optical sensors capable of detecting the ingress of foreign matter is provided on the front side of the top plate and one of the plurality of optical sensors detects the ingress of foreign matter is provided. It is known (see, for example, Patent Document 1). The optical sensor is a distance measuring sensor, and the detection wave transmitted from the transmitting unit receives the reflected wave reflected by the foreign matter at the receiving unit, and the distance to the foreign matter is measured by applying the triangular distance measuring method. When there is an optical sensor that indicates that the measurement distance to a foreign object is less than or equal to the operating distance, the gas stove can prevent the user's clothing from igniting by reducing the thermal power of the stove burner.

Japanese Unexamined Patent Publication No. 2018-128161

While using the stove burner, if the handle of the cooking pot is placed and the height position of the handle is less than the working distance, the heating power of the stove burner is reduced, but after that, it tries to increase the heating power to the initial state. Then, the firepower was repeatedly squeezed again, which was not easy to use.

An object of the present invention is to provide a stove that can prevent the handle of a cooking container from being detected when the foreign matter detected by the sensor is the handle of the cooking container.

The stove according to claim 1 is a sensor arranged in front of the stove burner and including a light emitting unit that emits infrared rays upward and a light receiving unit that emits light and receives reflected light reflected by a foreign substance. Based on the reflected light received by the light receiving portion of the sensor, a foreign matter determining means for determining whether or not the foreign matter is detected within a predetermined height range, and the foreign matter determining means for determining whether the foreign matter is detected within the predetermined height range. When it is determined that the foreign matter is detected, the foreign matter determining means detects the foreign matter within the predetermined height range in the stove provided with the thermal power controlling means for reducing the thermal power of the stove burner. When the determination is made, the handle determining means for determining whether the foreign matter is the handle of the cooking container, and when the handle determining means determines that the foreign matter is the handle, the foreign matter determining means is used in the sensor that detects the foreign matter. It is characterized by including a changing means for changing the threshold value of the predetermined height range when determining the foreign matter from the first threshold value before detecting the foreign matter to the second threshold value lower than the height of the handle. And.

The control according to claim 2 determines whether the height of the foreign matter detected by the sensor is higher than the height of the handle after the changing means changes the threshold value from the first threshold value to the second threshold value. The re-judgment means is provided, and when the re-judgment means determines that the height of the foreign matter is higher than the height of the handle, the re-judgment means returns the threshold value from the second threshold value to the first threshold value. It is good.

The stove according to claim 3 does not change the threshold value until the stove burner extinguishes after the changing means changes the threshold value from the first threshold value to the second threshold value, and the stove burner is reignited. In that case, it is preferable to provide a reignition return means for returning the threshold value to the first threshold value.

In the stove of claim 4, the handle determining means may determine the foreign matter as the handle when the foreign matter continues to be detected within a certain height range for a predetermined time or longer by the sensor.

According to the stove of claim 1, even if the handle of the cooking container is detected as a foreign substance and the heating power of the stove burner is reduced, the heating power of the stove burner can be increased thereafter, so that the usability of the stove can be improved. In addition, the threshold value of the sensor that detects the handle as a foreign object is changed from the first threshold value to the second threshold value, and the threshold value of the other sensors is not changed. Therefore, if a foreign substance enters at a position other than the handle, the control burner The firepower can be reduced. Therefore, the stove can achieve both usability and safety.

According to the stove of claim 2, for example, when the height of the handle is increased by putting the cooking container on the stove burner and then removing the handle from the cooking container, the threshold is changed from the second threshold to the first threshold. Therefore, when another foreign substance is detected, the heating power of the stove burner can be quickly reduced. As a result, the stove can ensure safety.

According to the stove of claim 3, there are usually few opportunities to replace the cooking container with another one without stopping the burning of the stove burner. In the present invention, after the foreign matter is determined to be the handle and the threshold value is changed to the second threshold value, the threshold value is not changed as the second threshold value until the stove burner is extinguished, so that the usability can be improved. Then, at the time of reignition, the threshold value is returned to the first threshold value, so that when another foreign matter is detected, the thermal power of the stove burner can be quickly reduced. As a result, the stove can ensure safety.

According to the stove of claim 4, it is possible to distinguish between a foreign matter that has accidentally entered the stove burner and a foreign matter that has a fixed position such as a handle.

It is a perspective view of the stove 1. It is a top view of the stove 1. It is a top view of the sensor 30. It is sectional drawing which shows the structure of a gas supply mechanism 50. It is the figure which showed the ignition danger range at the time of a large heat power and a small heat power. It is a block diagram which shows the electric structure of a stove 1. It is a flowchart of thermal power control processing. It is a flowchart which shows the continuation of FIG. It is a conceptual diagram of a thermal power control process. It is a flowchart of thermal power control processing (modification example).

Hereinafter, embodiments of the present invention will be described. Unless otherwise specified, the structure of the device and the like described below are not intended to be limited thereto, but are merely explanatory examples. The drawings are used to illustrate the technical features that can be adopted by the present invention.

The structure of the stove 1 will be described with reference to FIGS. 1 and 2. The stove 1 is a built-in stove. The stove 1 includes a housing 2 and a top plate 3. The top plate 3 is made of glass. A left burner 4 is provided on the left side of the top plate 3, and a right burner 5 is provided on the right side. The left burner 4 and the right burner 5 are examples of a stove burner. An exhaust port 7 for a grill is provided on the rear end side of the top plate 3. Non-transparent printing is applied to the entire top plate 3. A sensor window portion 15 having a substantially arc shape in a plan view is provided on the front side of the left burner 4, and a sensor window portion 16 having a substantially arc shape in a plan view is provided on the front side of the right burner 5. A sensor window 17 having a substantially rectangular shape in a plan view is also provided at the center of the front side of the top plate 3 in the left-right direction. The sensor window portions 15 to 17 are transparent regions, and when viewed from above, they transmit below the top plate 3 (see FIG. 2). Below the sensor window portion 15, four sensors 31 to 34 are arranged from left to right, respectively. Below the sensor window 16, four sensors 35 to 38 are arranged from left to right, respectively. One sensor 39 is arranged below the sensor window 17. These nine sensors 31 to 39 (hereinafter collectively referred to as "sensor 30") are general distance measuring sensors capable of measuring the distance to a foreign matter located above, and are, for example, infrared sensors.

On the top plate 3, on the front side of the sensor window portion 15, a left operation portion 11 for operating the left burner 4 is provided. On the front side of the sensor window portion 16, a right operation portion 12 for operating the right burner 5 is provided. A grill operating portion 13 for operating the grill is provided on the front side of the sensor window portion 17. Various capacitive switches, display units, and the like are arranged on the left operation unit 11, and for example, an ignition / fire extinguishing switch 21, a thermal power reduction switch 22, and a thermal power increase switch 23 are arranged. The ignition / fire extinguishing switch 21 receives the ignition and extinguishing of the left burner 4. The thermal power reduction switch 22 gradually reduces the thermal power of the left burner 4 each time it is touched with a fingertip. Each time the heat increase switch 23 is touched with a fingertip, the heat power of the left burner 4 is gradually increased. The thermal power decrease switch 22 and the thermal power increase switch 23 sense the touch of the fingertip and input the sense signal to the control circuit 70 (see FIG. 6) described later. The control circuit 70 increases or decreases the amount of gas in the gas supply mechanism 50 (see FIG. 4) described later in response to the sensing signal, and adjusts the amount of gas supplied to the corresponding left burner 4. Similar switches, display units, and the like are also arranged on the right operation unit 12.

A power switch 19 is provided near the upper right corner of the front surface of the housing 2. A grill door 8 is provided at the center of the front surface of the housing 2. The grill door 8 is movably supported toward the front side, and opens and closes an opening on the front side of the grill storage (not shown) provided inside the housing 2. A grill burner (not shown) is provided in the grill chamber.

The structure and function of the sensor 30 will be described with reference to FIG. The sensor 30 includes a sensor housing 300. The sensor housing 300 has a bottomed tubular shape with an opening at the top, and is supported by the lower surface of the top plate 3. The sensor housing 300 houses a light emitting unit 41 and a light receiving unit 42 inside. A partition wall 302 is provided between the light emitting unit 41 and the light receiving unit 42. The light emitting unit 41 emits infrared light upward. The light receiving unit 42 receives the reflected light reflected by the foreign matter from the infrared light emitted by the light emitting unit 41. The sensor 30 measures the distance to a foreign object by applying a triangular ranging method based on the intensity of the reflected light received by the light receiving unit 42.

When a foreign substance (for example, a part of the user's body) enters above the corresponding sensor windows 15 to 17, the sensor 30 transmits the reflected light reflected by the foreign substance to the sensor windows 15 to 17. It is received by the light receiving unit 42 via the above, and the distance to the foreign matter is measured. The sensor 30 outputs the measured distance to the foreign matter as a distance signal toward the sensor input circuit 85 (see FIG. 6) described later. When the CPU 71 of the control circuit 70 determines that the height of the detected foreign matter is within the predetermined height range based on the received distance signal, it determines that there is a foreign matter.

The structure of the gas supply mechanism 50 of the left burner 4 will be described with reference to FIG. Since the gas supply mechanism of the right burner 5 has the same configuration as the gas supply mechanism 50 of the left burner 4, the description thereof will be omitted. The gas supply mechanism 50 includes a gas supply pipe 51, a valve mechanism 52, a gas adjustment mechanism 53, a control motor 54, a gas supply pipe 55, a gas adjustment mechanism 56, and the like in order from the upstream side in the direction in which the gas flows. A source gas solenoid valve 511 is provided at one end on the upstream side of the gas supply pipe 51. The valve mechanism portion 52 is connected to one end on the downstream side of the gas supply pipe 51. The valve mechanism portion 52 is provided with a gas flow path inside, and in the gas flow path, the safety valve 521 and the main valve 522 are provided in this order from the upstream side in the gas flow direction.

The gas adjusting mechanism 53 is connected to the downstream side of the valve mechanism portion 52 and includes a gas flow path 531 and a needle valve 532. The gas flow path 531 is connected to the gas flow path of the valve mechanism portion 52. The needle valve 532 is movably provided near the outlet of the gas flow path 531, and the amount of gas flowing through the gas flow path 531 can be continuously adjusted by continuously adjusting the opening degree of the valve. The control motor 54 is a drive source for the safety valve 521, the main valve 522, and the needle valve 532, and is controlled by the CPU 71 (see FIG. 6) of the control circuit 70. An angle detection sensor 541 and an origin microswitch 542 are provided on the output shaft of the control motor 54. The angle detection sensor 541 detects the rotation angle of the output shaft of the control motor 54. The origin microswitch 542 is a microswitch for detecting the origin of the control motor 54. The gas supply pipe 55 is connected to the outlet of the gas flow path 531 and extends toward the left burner 4. A nozzle 551 is provided at one end on the downstream side of the gas supply pipe 55. The nozzle 551 is arranged to face the gas inflow portion 401 provided in the burner main body 400 of the left burner 4.

The gas adjusting mechanism 56 is provided in the middle of the gas supply pipe 55, and includes a bypass pipe 561, a solenoid valve 562, a weak bypass needle 563, and the like. One end of the bypass pipe 561 is connected to a branch portion 61 provided in the middle of the gas supply pipe 55, and the other end is connected to a merging portion 62 provided on the downstream side of the branch portion 61. As a result, a part of the gas flowing through the gas supply pipe 55 flows from the branch portion 61 to the bypass pipe 561, and joins the gas flowing through the gas supply pipe 55 at the merging portion 62. The solenoid valve 562 is provided in the bypass pipe 561. The weak bypass needle 563 is provided between the branch portion 61 and the confluence portion 62 of the gas supply pipe 55, and adjusts the gas flow rate to the minimum flow rate by narrowing the flow path area of the gas supply pipe 55. The "minimum flow rate" means a minimum flow rate preset in the adjustable range of the gas flow rate, and is, for example, the weakest minimum thermal power (for example, a melting fire) so as not to misfire the left burner 4. It is advisable to set the minimum flow rate to.

The operation of the gas supply mechanism 50 will be described. Before ignition of the left burner 4, the safety valve 521 and the main valve 522 are in a mechanically closed state. The needle valve 532 and the solenoid valve 562 are maintained on the open side. When the user touches the ignition / fire extinguishing switch 21, the original gas solenoid valve 511 opens and the control motor 54 is energized. By driving the control motor 54, the safety valve 521 and the main valve 522 are pushed in, and the gas flow path is opened. The gas flows from the gas flow path of the valve mechanism portion 52 through the gas flow path 531 of the gas regulation mechanism 53 and flows to the gas supply pipe 55. The gas is ejected from the nozzle 551 of the gas supply pipe 55. The ejected gas flows into the burner main body 400 from the gas inflow portion 401 while entraining the surrounding air, and is mixed with the air. The mixed gas mixed with air is supplied to the flame hole portion of the left burner 4. The igniter 27 operates at the same time as the control motor 54 is driven, and the gas ejected from the flame hole is ignited. The left burner 4 is in a burning state. When the thermocouple 26 detects a flame, for example, a lamp (not shown) provided on the ignition / fire extinguishing switch 21 lights up.

The stove 1 rotates the control motor 54 in the forward and reverse directions in response to the touch operation of the thermal power reduction switch 22 and the thermal power increase switch 23 by the user. The power of the rotating shaft of the control motor 54 is converted into power for adjusting the opening degree of the needle valve 532 by the gear mechanism 543. The gear mechanism 43 is a power transmission mechanism including a gear, a cam, or the like, and for example, the mechanism described in JP-A-2015-36593 may be applied. The gas adjusting mechanism 53 controls the control motor 54 and continuously adjusts the opening degree of the needle valve 532, so that the thermal power of the left burner 4 can be continuously and gently adjusted.

The opening degree of the needle valve 532 in the gas adjusting mechanism 53 is the adjusting opening degree adjusted by the touch operation of the thermal power reduction switch 22 and the thermal power increase switch 23, and the solenoid valve 562 of the gas adjustment mechanism 56 is in the open state. At this time, the burner thermal power corresponding to the gas flow rate integrated and adjusted by the gas adjusting mechanisms 53 and 56 is the set thermal power set by the operation of the thermal power decrease switch 22 and the thermal power increase switch 23.

The general operation of the gas supply mechanism 50 at the time of detecting a foreign substance will be described. In the present embodiment, as will be described later, when a plurality of sensors 30 are used to detect the entry of foreign matter on the front side of the stove burner in the combustion state, control is performed to momentarily reduce the thermal power of the stove burner in the combustion state. For example, the stove 1 closes the solenoid valve 562 of the gas adjusting mechanism 56 in order to momentarily reduce the thermal power of the left burner 4 in the combustion state. As a result, the bypass pipe 561 is momentarily shut off, so that the gas flow rate flowing from the gas supply pipe 55 toward the left burner 4 is adjusted to the minimum flow rate by the weak bypass needle 563. Therefore, the thermal power of the left burner 4 in the combustion state is momentarily adjusted to the minimum thermal power. As a result, the risk of foreign matter ignition can be avoided.

When the user touches the ignition / fire extinguishing switch 21 again to extinguish the left burner 4, the stove 1 rotates the control motor 54 in the reverse direction. As a result, the safety valve 521 and the main valve 522 of the valve mechanism 52 are driven in opposite directions, the original gas solenoid valve 511 is closed, and the gas flow path is closed. In this way, the gas supply to the left burner 4 is cut off and the fire is extinguished. The lamp (not shown) of the ignition / fire extinguishing switch 21 is turned off. Therefore, the user can recognize that the left burner 4 has been extinguished.

With reference to FIG. 5, the ignition danger range that changes according to the thermal power of the stove burner will be described. The ignition risk range is the range in which the flame of the stove burner has a risk of igniting foreign matter (clothes, etc.). Here, the flame of the left burner 4 will be described. For example, as shown in FIG. 5 (1), when the cooking pot 91 is heated by the left burner 4 and the cooking pot 91 is heated, the height of the ignition danger range is H1. H1 is the height from the top plate 3. On the other hand, as shown in FIG. 5 (2), the height of the ignition danger range is H2, which is lower than H1, because the flame becomes smaller at the time of small thermal power. Here, if the height threshold value for determining the presence or absence of foreign matter is set to H1 in all thermal powers, the risk of ignition is reduced, but in the case of small thermal powers, the range is not the ignition danger range. Even if a foreign object enters, the firepower will be reduced, so it is not easy to use. Therefore, in the stove 1 of the present embodiment, the determination value is changed according to the thermal power by executing the thermal power control process (FIGS. 7 and 8) described later. For example, H1 is set as a determination value at the time of high thermal power, and H2 lower than H1 is set as a determination value at the time of small thermal power. Then, when a foreign substance is detected, the thermal power is instantly reduced to the minimum thermal power, and control is performed to ensure safety.

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, and the like. The CPU 71 comprehensively controls various operations of the stove 1. The ROM 72 stores, for example, various programs including a thermal power control program. The thermal power control program executes the thermal power control process (see FIGS. 7 and 8) described later. The RAM 73 temporarily stores various types of information. The non-volatile memory 74 stores various information including burner thermal power information. The burner thermal power information is information in which the rotation angle of the output shaft of the control motor 54 is associated with the burner thermal power.

The control circuit 70 includes a power supply circuit 81, a thermistor input circuit 82, a thermocouple input circuit 83, an igniter circuit 84, a left operation unit 11, a right operation unit 12, a grill operation unit 13, a sensor input circuit 85, a buzzer circuit 86, and a motor. The circuit 87, the electromagnetic valve circuit 88, the sensor input circuit 89, and the like are electrically connected to each other. When the power switch 19 is pressed, the power supply circuit 81 steps down the alternating current (for example, 100V) supplied from the power supply 18 to direct current (for example, 5V), rectifies it, and supplies electric power to various circuits. The power of the stove 1 is turned on. When the power switch 19 is pressed again by the user, the power circuit 81 cuts off the power supply to the various circuits. The power of the stove 1 is turned off.

The thermistor input circuit 82 inputs a detection signal from the thermistor 25 (see FIG. 4) provided on the left burner 4 and the right burner 5 to the control circuit 70. The thermocouple input circuit 83 inputs the detection value (signal corresponding to the thermoelectromotive force) from the thermocouple 26 to the control circuit 70. The igniter circuit 84 drives the igniter 27 of the corresponding burner based on the control signal from the CPU 71. The left operation unit 11, the right operation unit 12, and the grill operation unit 13 sense the touch operation of the user, input the sensed signal to the control circuit 70, and based on the control signal from the control circuit 70, the left operation unit 11 The timer time and the like are displayed on the display unit of the right operation unit 12.

The sensor input circuit 85 inputs a distance signal from the sensors 31 to 39 to the control circuit 70. The buzzer circuit 86 drives the piezoelectric buzzer 77 based on the control signal of the CPU 71. The motor circuit 87 controls the drive of the control motor 54 based on the control signal from the CPU 71. The solenoid valve circuit 88 controls the opening and closing of the solenoid valve 562 based on the control signal from the CPU 71. The sensor input circuit 89 inputs each detection signal from the angle detection sensor 541 to the control circuit 70. The CPU 71 recognizes the rotation angle of the output shaft of the control motor 54 based on the detection signal from the angle detection sensor 541. The CPU 71 can specify the corresponding burner thermal power based on the recognized rotation angle of the output shaft of the control motor 54 and the burner thermal power information.

The thermal power control process will be described with reference to FIGS. 7 to 9. When the power switch 19 turns on the power of the stove 1, the CPU 71 turns on the power of the nine sensors 30. For example, when the user cooks with the left burner 4, when the cooking pot is placed on the trivet and the ignition / fire extinguishing switch 21 of the left operation unit 11 is touched, the left burner 4 is operated by the above operation of the gas supply mechanism 50. Is supplied with gas and ignited by the igniter 27. At this time, the needle valve 532 is maintained at the maximum opening degree, and the solenoid valve 562 is also maintained at the open side. Therefore, the thermal power of the left burner 4 becomes the set thermal power. The flame formed in the flame hole of the left burner 4 is detected by the thermocouple 26. When the flame of the left burner 4 is detected, the CPU 71 reads the thermal power control program from the ROM 72 and executes this process.

As shown in FIG. 7, the CPU 71 performs an initialization process and sets a determination value A, which is a height threshold value for determining the presence or absence of foreign matter (S10). The determination value A is an initial value and is stored in advance in the non-volatile memory 74. The determination value A is, for example, the height H1 of the ignition danger range shown in FIG. When the user changes the thermal power of the left burner 4 by touching the thermal power decrease switch 22 and the thermal power increase switch 23, the CPU 71 changes the determination value according to the thermal power of the left burner 4 (S11). The CPU 71 acquires a distance signal (measured voltage value) from the sensors 31 to 34 corresponding to the ignited left burner 4 and the central sensor 39 (S12). The CPU 71 acquires distance signals from sensors 31 to 34 and 39 for a predetermined number of times (for example, 4 times), calculates an average value of a predetermined number of distances, and uses sensors 31 to 34 and 39 to reach a foreign object. It is good to specify each.

The CPU 71 determines whether or not there is a sensor 30 whose height of the foreign matter is equal to or less than the determination value (S13). When there is no sensor 30 below the determination value (S13: NO), the CPU 71 adjusts to the set thermal power adjusted by the touch operation of the thermal power reduction switch 22 and the thermal power increase switch 23 (S31). At this time as well, the CPU 71 changes the determination value according to the set thermal power. The CPU 71 determines whether the user touches the ignition / fire extinguishing switch 21 to perform the fire extinguishing operation (S32). When the fire extinguishing operation is performed (S32: YES), the CPU 71 extinguishes the left burner 4 (S33), and ends this process. If the fire extinguishing operation is not performed (S32: NO), the CPU 71 returns to S11 and repeats the process.

As shown in FIG. 9 (1), for example, when the left burner 4 is ignited in a state where the determination value is A and the cooking pot 95 is placed on the trivet of the left burner 4, the height of the handle 96 of the cooking pot 95 is high. Is less than or equal to the determination value A set in S10 (S13: YES). In this case, as shown in FIG. 9 (2), assuming that a foreign substance has entered the ignition danger range, the CPU 71 closes the solenoid valve 562 of the gas adjusting mechanism 56 and instantly reduces the thermal power of the left burner 4 to the minimum thermal power. (S14). Subsequently, the CPU 71 reacquires a distance signal from the sensor that has detected the foreign matter in order to accurately measure the height of the foreign matter currently being detected (S15). The CPU 71 calculates the height of the currently detected foreign matter based on the re-acquired distance signal.

Next, the CPU 71 determines whether or not the height of the currently detected foreign matter is within a certain height range (S16). The constant height range is, for example, a height range of the determination value A or less, and is preferably set in a range assuming the height of the handle of a general cooking pot. The constant height range may be the same as the height range of the determination value A or less. When the height of the foreign matter is higher than the constant height range (S16: NO), it is unlikely that the detected foreign matter is the handle 96, so the CPU 71 returns to S11 and repeats the above process.

On the other hand, when the height of the handle 96 detected as a foreign matter is H3, the handle 96 is within a certain height range (S16: YES), so that the CPU 71 determines the foreign matter after detecting the foreign matter in, for example, S15. It is determined whether the time has passed (S17). The CPU 71 may start the measurement for a predetermined time from the time when the foreign matter is first detected in S12. Until the predetermined time elapses (S17: NO), the CPU 71 returns to S15 and continues to monitor the height of the foreign matter. When a predetermined time elapses while the height of the foreign matter is within a certain height range (S17: YES), the foreign matter remains at that position for at least a predetermined time, so that the foreign matter is fixed to something. It can be judged that it was done.

Therefore, the CPU 71 determines that the currently detected foreign matter is the handle 96 of the cooking pot 95 (S18), and as shown in FIG. 9 (3), only the determination value of the specific sensor that detected the handle 96 is the handle 96. The determination value is changed to B, which is lower than the height of (S19). As a result, the stove 1 does not determine the detected handle 96 as a foreign substance, so that the user can increase the thermal power of the left burner 4 during combustion. Therefore, the stove 1 can improve the usability. Further, since the judgment value of the sensor other than the specific sensor that detected the handle 96 remains A, when another foreign matter enters the height range of the judgment value A or less in the region other than the position of the handle 96. , The firepower of the left burner 4 can be instantly reduced. As a result, the safety of the stove 1 can be ensured.

On the other hand, when the state in which the height of the foreign matter is within the constant height range does not continue for a predetermined time (S17: NO), the CPU 71 does not determine that the foreign matter is the handle 96, returns to S15, and repeats the process.

By the way, after determining that the foreign object is the handle 96 (S18) and changing the determination value from A to B (S19), the CPU 71 reacquires the distance signals from the sensors 31 to 34 and 39 as shown in FIG. 8 (S19). S21). Based on the acquired distance signal, the CPU 71 determines whether or not the height of the foreign matter determined to be the handle 96 is higher than the determination value A (S22). If the height of the handle 96 does not change (S22: NO), the handle 96 continues to stay at that position, so the CPU 71 returns to S11 in FIG. 7 and repeats the process. That is, the sensor that detects the handle 96 detects the entry of foreign matter within the height range of the determination value B, and the other sensors detect the entry of foreign matter within the height range of the determination value A.

Here, for example, as shown in FIG. 9 (4), when the handle 96 is removed from the cooking pot 95 and moved to a place where the handle 96 is higher than the determination value A and there is no problem in safety (S22). : YES), It is not preferable for safety that the state of the determination value B continues. Therefore, the CPU 71 returns the determination value of the specific sensor that determines that the foreign object is the handle 96 from B to A (S23). As a result, the stove 1 can return at the time of ignition and can uniformly detect foreign matter entering the height range of the determination value A or less with respect to the left burner 4, so that safety can be improved.

Then, the CPU 71 determines whether the user touches the ignition / fire extinguishing switch 21 to perform the fire extinguishing operation (S24). When the fire extinguishing operation is not performed (S24: NO), the CPU 71 returns to S11 in FIG. 7 and repeats the process. When the fire extinguishing operation is performed (S24: YES), the CPU 71 extinguishes the left burner 4 (S25), and ends this process.

As described above, the stove 1 of the present embodiment is provided with a plurality of sensors 30 arranged on the front side of the left burner 4 and the right burner 5. The sensor 30 includes a light emitting unit 41 and a light receiving unit 42. The light emitting unit 41 emits infrared light upward. The light receiving unit 42 receives the reflected light that the light emitting unit 41 emits and is reflected by the foreign matter. The CPU 71 of the stove 1 determines whether or not a foreign substance is detected within a predetermined height range from the top plate 3 based on the reflected light received by the light receiving unit 42 of the sensor 30. When a foreign matter is detected within a predetermined height range, the CPU 71 limits the thermal power of the left burner 4 or the right burner 5 corresponding to the sensor 30 that has detected the foreign matter. For example, after reducing the heating power of the left burner 4, the CPU 71 determines whether the detected foreign matter is the handle 96 of the cooking pot 95. When the detected foreign matter is determined to be the handle 96, the CPU 71 changes the determination value in the predetermined height range when determining the foreign matter from the determination value A before detecting the foreign matter to the determination value B lower than the handle 96. To do. As a result, the user can increase the thermal power of the left burner 4 regardless of the handle 96, so that the usability can be improved.

In the above description, the CPU 71 that executes the process of S13 of FIG. 7 is an example of the foreign matter determination means of the present invention. The CPU 71 that executes the process of S14 is an example of the thermal power control means of the present invention. The CPU 71 that executes the processes of S15 to S18 is an example of the handle determination means of the present invention. The determination value A is an example of the first threshold value of the present invention, and the determination value B is an example of the second threshold value of the present invention. The CPU 71 that executes the processes of S21 and S22 of FIG. 8 is an example of the re-judgment means of the present invention. The CPU 71 that executes the process of S23 is an example of the return means of the present invention.

The present invention is not limited to the above embodiment, and various modifications can be made. For example, in the thermal power control process shown in FIG. 7, after the foreign matter was determined to be the handle 96 of the cooking pot 95 and the determination value was changed to B, the height of the handle 96 became higher than the height when it was first detected. In this case, the determination value is returned to A, but for example, the determination value B may remain until the fire is extinguished, and the determination value may be returned to A when the fire is reignited.

A modified example of the thermal power control process will be described with reference to FIGS. 9 and 10. Since the thermal power control processing of this modification is common to the processing of S10 to S19 of the thermal power control processing shown in FIG. 7, the subsequent processing will be mainly described. For example, as shown in FIG. 10, in the burning left burner 4, the CPU 71 detects the handle 96 of the cooking pot 95 as a foreign substance (S13: YES), and after instantaneously reducing the heating power to the minimum heating power (S14, (See FIG. 9 (2)), the height of the foreign matter is calculated again, and when the state within the constant height range continues for a predetermined time (S15, S16: YES, S17: YES), the detected foreign matter is determined to be the handle 96. (S18). Further, the CPU 71 changes the determination value of the sensor that has detected the handle 96 from the initial determination value A to the determination value B lower than the height of the handle 96 (see S19, FIG. 9 (3)).

Here, it is considered that there is usually little opportunity to replace the cooking pot 95 with another cooking pot without stopping the combustion of the left burner 4. Therefore, in this modification, the CPU 71 keeps the determination value of the sensor that detected the handle 96 as B, and determines whether the user touches the ignition / fire extinguishing switch 21 to perform the fire extinguishing operation (S41). When the fire extinguishing operation is not performed (S41: NO), the CPU 71 returns to S11 in FIG. 7 and repeats the process. When the fire extinguishing operation is performed (S41: YES), the CPU 71 extinguishes the left burner 4 (S42) and ends this process. Then, when the left burner 4 is extinguished and then the left burner 4 is reignited, the determination value A, which is the initial initial value, is set again in the initialization process (S10 in FIG. 7), thus ensuring safety. it can. The CPU 71 that executes the process of S10 in FIG. 7 is an example of the reignition return means of the present invention.

In addition to the above modifications, the present invention can be further modified. The stove 1 of the above embodiment is a built-in stove, but it may be a table stove. The number of stoves is two in the above embodiment, but may be one or three or more. Moreover, the grill may be omitted.

The arrangement, number, and location of the plurality of sensors 30 on the top plate 3 are not limited to the above embodiment, and can be freely changed. The central sensor 39 may be omitted. The sensor 30 is an infrared sensor that emits infrared light, but any sensor that can detect foreign matter may be used.

In the above embodiment, for convenience of explanation, two determination values A and B have been described, but more determination values may be set.

In the above embodiment, the thermal power control process in the left burner 4 has been described, but the same applies to the thermal power control process in the right burner 5.

In the above embodiment, the thermal power is adjusted by the gas supply mechanism 50 corresponding to each stove burner, but the structure may be a structure other than the above embodiment.

1 Stove 4 Left burner 31-39 Sensor 41 Light emitting part 42 Light receiving part 71 CPU
95 Cooking pot 96 Handles A, B Judgment value

Claims (4)

With the stove
A sensor arranged in front of the stove burner and provided with a light emitting unit that emits infrared rays upward and a light receiving unit that emits light and receives reflected light reflected by a foreign substance.
A foreign matter determining means for determining whether or not the foreign matter has been detected within a predetermined height range based on the reflected light received by the light receiving portion of the sensor, and the foreign matter determining means for detecting the foreign matter within the predetermined height range. If it is determined that the stove has been used, in a stove equipped with a thermal power control means for reducing the thermal power of the stove burner.
The thermal power control means
When the foreign matter determining means determines that the foreign matter has been detected within the predetermined height range, the handle determining means for determining whether the foreign matter is the handle of the cooking container and the handle determining means.
When the handle determining means determines that the foreign matter is the handle, the sensor that detects the foreign matter detects the foreign matter at a threshold value in the predetermined height range when the foreign matter determining means determines the foreign matter. The stove is provided with a changing means for changing from the previous first threshold value to a second threshold value lower than the height of the handle. After the changing means changes the threshold value from the first threshold value to the second threshold value, a re-judgment means for determining whether the height of the foreign matter detected by the sensor is higher than the height of the handle.
The re-judgment means is provided with a means for returning the threshold value from the second threshold value to the first threshold value when it is determined that the height of the foreign matter is higher than the height of the handle. The stove according to claim 1. After the changing means changes the threshold value from the first threshold value to the second threshold value, the threshold value is not changed until the stove burner is extinguished, and when the stove burner is reignited, the threshold value is set. The stove according to claim 1, further comprising a reignition return means for returning to the first threshold value. Any one of claims 1 to 3, wherein the handle determining means determines the foreign matter as the handle when the foreign matter continues to be detected within a certain height range for a predetermined time or longer by the sensor. The stove described in.

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