JP7427186B2 - Stove - Google Patents

Description

The present invention relates to a stove.

Conventionally, a gas stove is equipped with a plurality of optical sensors that can detect the entry of a foreign object on the front side of the top plate, and when one of the plurality of optical sensors detects the entrance of a foreign object, the firepower of the stove burner can be reduced. known (for example, see Patent Document 1). The optical sensor is a distance-measuring sensor that uses infrared light emitted directly above from a light-emitting part and receives reflected light reflected by a foreign object at a light-receiving part, and measures the distance to the foreign object by applying a triangular distance measurement method. do. If there is an optical sensor that indicates that the measured distance to the foreign object is less than the working distance, the gas stove can prevent the user's clothes from catching fire by reducing the heating power of the stove burner.

Japanese Patent Application Publication No. 2018-128161

An object of the present invention is to provide a cooking stove that can detect foreign objects with high accuracy by irradiating infrared light emitted from a light emitting part onto foreign objects located above without diffusing them into the surroundings.

The stove of the present invention includes a light-emitting part that is provided on the lower side of the top plate and emits infrared rays upward, and a window part that is provided in the top plate and has translucency through which the infrared rays emitted by the light-emitting part are transmitted. a sensor having a light receiving section that receives reflected light that passes upward and is reflected by a foreign object located above the top plate, and is capable of detecting the foreign object based on the reflected light received by the light receiving section. In the stove, the sensor includes a main body that supports the light emitting part and the light receiving part toward a lower surface of the top plate, and a main body that is provided on the main body and surrounds the light emitting part and the light receiving part in a cylinder. a cylindrical part surrounding the top plate in a shape and extending upward toward the lower surface of the top plate; a partition wall provided inside the cylindrical part to partition the light emitting part side and the light receiving part side; A plate-shaped shielding part provided on the light emitting part side of the partition wall and shielding the infrared rays emitted from the light emitting part, and a circular through hole provided in the shielding part and transmitting the infrared rays. , the height position of the lower surface of the shielding part is the same as the height position of the upper part of the light emitting part, and the through hole is disposed directly above the light emitting part, and the diameter of the through hole is equal to the height position of the upper surface of the light emitting part. It is characterized by being shorter than the width of .

According to the stove of the present invention, the sensor includes a main body portion and a cylindrical portion. The main body supports the light emitting section and the light receiving section toward the lower surface of the top plate. The cylindrical portion is provided in the main body, surrounds the light emitting portion and the light receiving portion in a cylindrical shape, and extends upward toward the lower surface of the top plate. Thereby, the stove can irradiate the foreign object located above with the infrared light emitted from the light emitting part without diffusing it to the surroundings, so that the foreign object can be detected with high accuracy.

1 is a perspective view of a stove 1. FIG. FIG. 1 is a plan view of the stove 1. FIG. 3 is a plan view of a sensor 30. FIG. FIG. 4 is a sectional view taken along line II in FIG. 3; 4 is a sectional view taken along the line II-II in FIG. 3. FIG. 1 is a diagram showing a method of reflection test 1. FIG. 2 is a graph showing the results of reflection test 1. It is a figure which shows the method of reflection test 2. It is a graph showing the results of reflection test 2. It is a sectional view of sensor 300 (modification).

Embodiments of the present invention will be described below. The structure of the device described below is merely an illustrative example and is not intended to be limiting unless specifically stated. The drawings are used to explain technical features that can be adopted by the present invention.

The structure of the stove 1 will be explained with reference to FIGS. 1 and 2. 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 stove burners. 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. On the front side of the left burner 4, a sensor window 15 having a substantially arc shape in plan view is provided so as to surround the front side of the left burner 4, and on the front side of the right burner 5, a sensor window portion 15 having a substantially arc shape in plan view is provided. A sensor window 16 is provided. A sensor window 17 having a substantially rectangular shape in plan view is also provided at the center in the left-right direction of the front side of the top plate 3 . The sensor windows 15 to 17 are transparent areas, and transmit the light below the top plate 3 when viewed from above (see FIG. 2).

Below the sensor window 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 "sensors 30") are general distance measuring sensors capable of measuring the distance to a foreign object located above, and are, for example, infrared sensors.

If the stove 1 detects a foreign object within a predetermined height range from the top plate 3 based on the reflected light received by the light receiving section 42 of each of the plurality of sensors 30, the stove 1 determines that there is a foreign object and stops the combustion process. Reduce the firepower of the stove burner to the minimum power. Thereby, the stove 1 can prevent foreign objects entering the stove burner from being ignited, thereby improving safety. Note that, as will be described later, these nine sensors 30 are supported so as to be tilted forward at an angle α (for example, 5 degrees) with respect to the top. Thereby, the influence of reflection from the stainless steel range hood 100 (see FIG. 8) provided above the stove 1 can be effectively reduced.

On the top plate 3, in front of the sensor window 15, a left operating section 11 for operating the left burner 4 is provided. A right operation section 12 for operating the right burner 5 is provided on the front side of the sensor window section 16. A grill operation section 13 for operating the grill is provided on the front side of the sensor window section 17. Various capacitance type switches, display parts, etc. are arranged on the left operation part 11, and for example, an ignition/extinguishing switch 21, a fire power reduction switch 22, and a heat power increase switch 23 are arranged. The ignition/extinguishing switch 21 accepts ignition and extinguishing of the left burner 4. The heat power reduction switch 22 reduces the heat power of the left burner 4 in stages every 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 increased in stages. The heat reduction switch 22 and the heat increase switch 23 sense the touch of a fingertip, and input the sensing signal to a control unit (not shown). The control unit increases or decreases the amount of gas in a gas supply mechanism (not shown) provided in the housing 2 in response to the sensing signal, and adjusts the amount of gas supplied to the corresponding left burner 4. Note that similar switches, a display section, etc. are also arranged on the right operation section 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 supported so as to be movable toward the front side, and opens and closes an opening on the front side of a grill storage (not shown) provided inside the housing 2. A grill burner (not shown) is provided inside the grill chamber.

The structure and function of the sensor 30 will be explained with reference to FIGS. 3 to 5. As shown in FIGS. 3 and 4, the sensor 30 includes a main body portion 301 and a cylindrical portion 302. The main body part 301 is formed into a substantially rectangular shape that is elongated in the left-right direction when viewed from above, and a light-emitting part 41 and a light-receiving part 42 are provided on the upper surface of the main body part 301 side by side in the left-right direction. The cylindrical portion 302 is formed into a substantially rectangular cylindrical shape that surrounds the upper surface of the main body portion 301 and extends upward. A partition wall 303 that partitions between the light emitting section 41 and the light receiving section 42 is erected inside the cylindrical section 302 . A plate-shaped shielding part 304 is provided above the light emitting part 41 in parallel to the upper surface of the main body part 301, and a circular through hole 305 is provided in the center thereof.

As shown in FIG. 5, the sensor 30 having the above configuration is fixedly supported on the lower surface side of the top plate 3 in a state where it is tilted forward relative to the top. The inclination angle α of the sensor 30 with respect to the horizontal plane is not particularly limited, but is preferably 10° or less, and more preferably 5°. Further, it is preferable to prevent the infrared light emitted from the light emitting section 41 and passing upward through the through hole 305 from hitting the inside of the cylindrical section 302 . Note that the effects of tilting the sensor 30 will be described later.

In such a sensor 30, the light emitting section 41 emits infrared light upward. When the infrared light passes through the through hole 305, its irradiation direction and light amount are limited to a constant value. The infrared light that has passed through the through hole 305 is transmitted through the sensor windows 15 to 17 (see FIG. 2) of the top plate 3 without being diffused to the surroundings by the cylindrical part 302, and is located above the top plate 3. The foreign object is irradiated. The reflected light reflected by the foreign object is reflected downward. The light receiving section 42 receives the reflected light that has passed through the sensor windows 15 to 17 of the top plate 3 and entered the cylindrical section 302 of the sensor 30, out of the reflected light that has been turned back downward. The light receiving section 42 has a resistance value that differs depending on the light condensing area on the light receiving surface, and outputs a current having a magnitude corresponding to the resistance value when measuring distance. Therefore, the stove 1 can measure the distance between the sensor 30 and the foreign object by acquiring the measured voltage value indicated by the detection signal output by the sensor 30 and performing calculation based on the triangulation method.

When a foreign object (for example, a part of the user's body, etc.) enters above the corresponding sensor window 15 to 17, the sensor 30 transmits the reflected light reflected by the foreign object to the sensor window 15 to 17. The distance to the foreign object is measured by the light receiving unit 42. The sensor 30 outputs the measured distance to the foreign object as a distance signal to a control unit (not shown). When the control unit determines that the height of the detected foreign object is within a predetermined height range based on the received distance signal, it determines that a foreign object is present.

The influence of reflection from the range hood 100 on the measured value of the sensor 30 will be explained with reference to FIGS. 6 and 7. FIG. 6 shows the method for reflex test 1. In reflection test 1, as a comparison product to the product of the present invention, a stove with a sensor 30 horizontally supported and fixed on the lower surface side of the top plate 3 was used, and the stove was installed below a stainless steel range hood 100. Then, the cooking pot 95 was placed on the trivet of the stove burner, and the handle 96 was arranged so that the sensor 30 could detect it as a foreign object.

In such a stove, infrared light is emitted upward from the light emitting section 41 of the sensor 30. The infrared light is reflected by the handle 96 located directly above, and the reflected light is received by the light receiving section 42. Here, if the optical axis of the infrared light emitted upward from the light emitting part 41 is P1, a part of the infrared light emitted upward along P1 passes near the handle 96, It is reflected at an angle perpendicular to the range hood 100. Assuming that the optical axis of the reflected light is R1, most of the reflected light that is reflected downward along R1 hits the light receiving section 42 of the sensor 30. In reflection test 1, the measured voltage value indicated by the detection signal output by the sensor 30 under these conditions is obtained, converted to distance by calculation based on the triangulation method, and the measured distance to the handle 96 is calculated. We investigated changes over time.

FIG. 7(1) is a graph of temporal changes in the distance to the handle 96 in reflex test 1. The measured distance to the handle 96 fluctuated significantly up and down like noise over time and was not stable. In reflection test 1, the height of the handle 96 from the top plate 3 was 8 cm, but the measured distance fluctuated significantly up and down around 25 cm. It is presumed that this is because most of the reflected light reflected by the range hood 100 hits the light receiving section 42 .

Therefore, in order to further confirm the influence of the range hood 100, a shielding plate 90 (see FIG. 6) is placed between the sensor 30 and the range hood 100, and the shielding plate 90 (see FIG. , the time change in the distance measured by the sensor 30 to the handle 96 was investigated. Note that the shielding plate 90 was made of a black material that does not easily reflect light. As a result, as shown in FIG. 7(2), the measured distance to the handle 96 was significantly different from FIG. 7(1), and was stably maintained at around 8 cm. As a result, it has been demonstrated that a stove in which the sensor 30 is supported and fixed horizontally is greatly affected by the reflected light from the range hood 100.

The effect of reducing the influence of reflection on the range hood 100 when using the product of the present invention will be described with reference to FIGS. 8 and 9. FIG. 8 shows the method for reflex test 2. In the reflection test 2, a stove 1 of the present invention, in which a sensor 30 was tilted forward and supported and fixed on the underside of a top plate 3, was used, and the stove 1 was installed below a stainless steel range hood 100. Then, the cooking pot 95 was placed on the trivet of the stove burner, and the handle 96 was arranged so that the sensor 30 could detect it as a foreign object.

In such a stove 1, infrared light is emitted from the light emitting part 41 of the sensor 30 in a direction that is inclined toward the front with respect to the top. As in reflection test 1, the infrared light is reflected by the handle 96 located directly above, and the reflected light is received by the light receiving section 42. Here, if the optical axis of the infrared light emitted diagonally forward from the light emitting unit 41 is P2, a part of the infrared light emitted diagonally forward along P2 passes through the vicinity of the handle 96. However, in the range hood 100, the infrared light having the optical axis P1 in reflection test 1 is reflected obliquely from the rear with respect to a position in front of the position where it is reflected. If the optical axis of the reflected light at this time is R2, the reflected light reflected along R2 is directed toward a position in front of the sensor 30. As a result, most of the reflected light does not hit the light receiving section 42 of the sensor 30, so it is presumed that the influence of the range hood 100 can be significantly reduced.

Therefore, in the reflection test 2, in order to demonstrate that the measured value of the sensor 30 is not easily influenced by the range hood 100, under the situation shown in FIG. We investigated how distance changes. In addition, in a state where the shielding plate 90 is not arranged, the handle 96 is arranged between a pair of adjacent sensors 30 and near the boundary of the detection area of each sensor so that it can be easily compared with the graph of FIG. 7(1). By doing so, we intentionally reproduced a situation where the measured distance becomes unstable due to noise. Note that the height of the handle 96 of the cooking pot 95 used in reflection test 2 was approximately 17 cm.

FIG. 9(1) is a graph of temporal changes in the measured distance to the handle 96 in reflection test 2. As described above, the measured distance is unstable due to noise, but this is not due to the influence of the range hood 100. The measurement distance fluctuated vertically around 25 cm. Then, as in reflection test 1, a shielding plate 90 (see FIG. 8) was placed between the sensor 30 and the range hood 100, and the time change in the distance measured by the sensor 30 to the handle 96 was examined. As a result, as shown in FIG. 9(2), the measured distance to the handle 96 showed a similar waveform, although the vertical amplitude was slightly smaller compared to FIG. 9(1). Moreover, the measured distance oscillated up and down around about 20 cm.

From the above results, in the product of the present invention, there was no significant change before and after placing the shielding plate 90 compared to the comparative product in reflection test 1, so compared to the comparative product, the measurement distance of the sensor 30 was significantly affected. It has been demonstrated that the influence of reflection from the range hood 100 can be reduced. Therefore, by tilting the sensor 30 toward the front with respect to the top, the stove 1 can detect foreign objects with high accuracy even if the highly reflective stainless steel range hood 100 is located above, its influence can be reduced. I understand.

Furthermore, regardless of the presence or absence of the shielding plate 90, the sensor 30 can detect foreign objects with high accuracy. Even so, since the distance measured by the sensor 30 does not change significantly due to noise, it is possible to prevent the heating power of the stove burner from repeatedly decreasing and returning to the original heating power.

As described above, the stove 1 of this embodiment includes the sensor 30 including the light emitting section 41 and the light receiving section 42. The light emitting section 41 emits infrared rays upward. The light receiving section 42 receives the reflected light emitted by the light emitting section 41 and reflected by a foreign object. The stove 1 can detect foreign objects based on the reflected light received by the light receiving section 42. In the stove 1, such a sensor 30 is provided on the top plate 3 at least in front of the left burner 4 and the right burner 5, and is inclined toward the front with respect to the top. Thereby, the incident angle of infrared light from the light emitting part 41 to the range hood 100 can be tilted. As a result, the amount of reflected light incident on the light receiving section 42 can be reduced, so that the influence on the foreign object detection result of the sensor 30 can be reduced.

Note that the present invention is not limited to the above embodiments, and various modifications are possible. Although the stove 1 in the above embodiment is a built-in stove, it may be a table stove. Further, although the number of stove burners is two in the above embodiment, it may be one or three or more. Also, the grill may be omitted.

Further, the arrangement, number, and location of the plurality of sensors 30 on the top plate 3 are not limited to the above embodiments, and can be freely changed. The central sensor 39 may be omitted. Although the sensor 30 is an infrared sensor that emits infrared light, it may be a reflective sensor that includes a light emitting part and a light receiving part.

Further, in the above embodiment, the sensor 30 is tilted upward toward the front side, but it may be tilted toward the rear side. This also makes it possible to tilt the angle of incidence of infrared light from the light emitting section 41 to the range hood 100, thereby reducing the amount of reflected light that enters the light receiving section 42.

Further, in the above embodiment, the sensors 31 to 34 and the sensors 35 to 38 are arranged in a substantially circular arc shape in a plan view in front of the left burner 4 and the right burner 5, but for example, nine sensors 31 to 39 may be arranged in a substantially straight line extending in the left-right direction in front of the left burner 4 and right burner 5.

Further, the structure of the sensor 30 is not limited to the above embodiment, and various changes are possible. As shown in FIGS. 4 and 5, the cylindrical portion 302 of the sensor 30 of the above embodiment extends obliquely upward in a straight line from the top of the main body 301 toward the bottom surface of the top plate 3. It may be bent upward from the middle. As shown in FIG. 10, a sensor 300, which is a modified example, is supported and fixed on the lower surface side of the top plate 3 in a state in which it is tilted forward with respect to the upper side, similarly to the above embodiment. The sensor 300 has the same parts as the sensor 30 of the above embodiment except for the cylindrical part 402, so the same parts are given the same reference numerals.

The cylindrical portion 402 of the sensor 300 includes an inclined extending portion 405 and an upwardly extending portion 406 . The inclined extension part 405 extends obliquely upward from the upper part of the main body part 301 with respect to the front side. The upward extending portion 406 is bent upward from the top of the inclined extending portion 405 and extends in a direction perpendicular to the lower surface side of the top plate 3 . By shaping the cylindrical portion 402 as described above, it is possible to receive only light incident on the light receiving portion from directly above.

1 Stove 4 Left burner 5 Right burner 30 Sensor 41 Light emitting section 42 Light receiving section

Claims (1)

a light emitting part provided on the lower side of the top plate and emitting infrared rays upward; and the infrared rays emitted by the light emitting part passing upward through a translucent window provided in the top plate, A stove comprising a sensor having a light receiving section that receives reflected light reflected from a foreign object located above the top plate, and capable of detecting the foreign object based on the reflected light received by the light receiving section,
The sensor is
a main body portion that supports the light emitting portion and the light receiving portion toward the lower surface side of the top plate;
a cylindrical portion provided in the main body portion, surrounding the light emitting portion and the light receiving portion in a cylindrical shape, and extending upward toward the lower surface of the top plate;
a partition wall provided inside the cylindrical part and partitioning the light emitting part side and the light receiving part side;
a plate-shaped shielding part provided on the light emitting part side of the partition wall inside the cylindrical part and shielding the infrared rays emitted from the light emitting part;
a circular through hole provided in the shielding part and transmitting the infrared rays ;
The height position of the lower surface of the shielding part is the same as the height position of the upper part of the light emitting part, and the through hole is arranged directly above the light emitting part,
A stove characterized in that the diameter of the through hole is shorter than the width of the light emitting part .

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