JP2019020008A - Range hood - Google Patents

Abstract

To provide a range hood which suppresses contamination in a detection part of a gas sensor and performs automatic ventilation operation while accurately interlocking a gas cooking apparatus with the range hood.SOLUTION: Each of multiple gas sensors 5 (5a and 5b) for detecting a concentration of a specific kind of gas contained in gas circulating in a ventilation path 4 inside a casing 10 that is disposed on a rear wall W has predetermined sensitivity with respect to combustion exhaust gas. At least one of the multiple gas sensors is disposed so as to face the ventilation path at a position retracted from an inner peripheral surface 4a of the ventilation path just by a predetermined dimension at a front side of a hood part 3 as a front-side gas sensor 5a. At least one of th multiple gas sensors is disposed so as to face the ventilation path at a position retracted from the inner peripheral surface of the ventilation path just by a predetermined dimension at a rear side of the hood part as a rear-side gas sensor 5b. A control part is configured to update air wind quantity based on the gas concentration obtained from the front-side gas sensor and the rear-side gas sensor, and preset air quantity.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a range hood, and more particularly, to a range hood provided with a blower and a control unit that controls the blower.

  For example, when cooking using a cooking appliance such as a gas stove or a gas grill, a ventilator used to discharge cooking exhaust to the outside includes a blower and a controller that controls the blower. There is a range hood.

  As such a range hood, Patent Literature 1 includes a gas sensor that detects the concentration of a specific type of gas, and the control unit obtains the gas concentration obtained by the gas sensor and the gas concentration thereof. A range hood is disclosed in which the set air volume is updated based on the set air volume at the time.

  That is, the range hood disclosed in Patent Literature 1 newly sets an appropriate set air volume corresponding to various cases based on the gas concentration and the set air volume obtained from the gas sensor (that is, updates the set air volume). ) Is configured to be able to.

  And in the range hood of the said patent document 1, when cooking with a gas stove is performed and the gas concentration used as detection object reaches a predetermined value (for example, 1st threshold value), the air blower of a range hood has stopped However, the blower of the range hood is driven according to the detection value (change rate K value) of the gas sensor.

  Thereby, when cooking with a cooking appliance such as a gas stove, if the gas concentration exceeds the first threshold, it becomes possible to automatically drive the blower device of the range hood. It is meaningful to keep the area where the kitchen is installed, usually the kitchen environment in good condition.

  In addition, the range hood disclosed in Patent Document 1 is configured so that the blower of the range hood can be automatically stopped when the gas concentration is equal to or lower than the second threshold value. Therefore, energy can be saved by not operating the blower in vain.

  That is, the range hood described in Patent Document 1 does not require the gas stove and the range hood to communicate with each other by a method such as wired communication or wireless communication, and the gas stove and the range hood are the same manufacturer. Without having to be a specific type, the gas stove and the range hood can be linked to each other, and the range hood can be automatically ventilated.

JP 2006-173193 A

  However, the range hood of Patent Document 1 includes the following problems.

  The range hood is often used by being installed directly above a gas cooking device such as a gas stove. For this reason, in the range hood of patent document 1, a gas sensor will receive the flow of combustion exhaust gas strongly because a range hood is installed right above gas cooking appliances, such as a gas stove. As a result, oil smoke or water vapor generated during cooking directly licks the surface of the gas sensor, so that dust containing oil dust or the like adheres to the detection part of the gas sensor, making it impossible to accurately detect the concentration of a predetermined gas. There is a case.

  On the other hand, when the gas sensor is arranged in a place where it is difficult to receive the flow of the combustion exhaust gas, the gas sensor is moved away from the flow of the combustion exhaust gas, and the combustion exhaust gas reaching the gas sensor is sucked together with the combustion exhaust gas. There is a risk of dilution with air, and the concentration of a predetermined gas in the combustion exhaust gas cannot be detected with high accuracy, making it difficult to accurately link a gas cooking device such as a gas stove and a range hood.

  The present invention solves the above-mentioned problem of the range hood, suppresses the adhesion of oil and soot to the detection part of the gas sensor, and automatically synchronizes the gas cooking device such as a gas stove and the range hood with automatic ventilation. An object of the present invention is to provide a range hood that can be operated.

In order to achieve the above object, the range hood of the present invention provides:
A casing that has a ventilation path inside and is installed on the rear wall surface that is the wall surface on the back side when viewed from the front,
A hood portion configured to have a suction port serving as an upstream end of the ventilation path, collect gas rising from below, and suck the gas from the suction port;
A blowing means provided in the ventilation path;
A control unit for controlling the blowing means,
The set air volume is configured to be able to be set continuously or stepwise from an air volume of 0 to an appropriately set upper air volume, and
A range hood configured such that the control unit controls the blower so that the amount of gas blown by the blower becomes the set air volume,
A plurality of gas sensors for detecting the concentration of a specific type of gas contained in the gas flowing through the ventilation path;
Each of the plurality of gas sensors has a predetermined sensitivity to combustion exhaust gas,
At least one of the plurality of gas sensors, as a front side gas sensor, faces the ventilation path at a position on the front side of the hood portion and retracted by a predetermined dimension from the inner peripheral surface of the ventilation path. Arranged,
At least one of the plurality of gas sensors, as a rear gas sensor, faces the ventilation path at a position on the rear side of the hood portion and retracted by a predetermined dimension from the inner peripheral surface of the ventilation path. Arranged,
The control unit is configured to update the set air volume based on a gas concentration obtained from the front gas sensor and the rear gas sensor and the set air volume.

  In the range hood of this invention, it is preferable that the said front side gas sensor and the said back side gas sensor have a predetermined sensitivity with respect to hydrogen.

  Further, during operation of the blower, the control unit is configured to stop the blower when the gas concentration detected by the rear gas sensor is equal to or lower than a predetermined stop gas concentration. It is preferable.

  Moreover, it is preferable that the set air volume is updated based on a value obtained by weighting each gas concentration obtained by the front gas sensor and the rear gas sensor and the set air volume. .

  The range hood of the present invention is configured as described above, and it is possible to prevent oil smoke and the like from adhering to the detection part of the gas sensor and reduce the detection sensitivity, and at the time of stopping the range hood, By detecting the combustion exhaust gas generated from a gas cooking device such as a gas stove during cooking by the rear gas sensor, the range hood can be accurately started.

  That is, according to the present invention, since the front side gas sensor and the rear side gas sensor are disposed at a position retracted by a predetermined dimension from the inner peripheral surface of the ventilation path, the gas sensor is prevented from receiving a strong flow of combustion exhaust gas. In addition, it is possible to suppress a decrease in sensitivity due to oil smoke or the like adhering to the detection portion of the gas sensor, and the rear side gas sensor is disposed in a recessed position, and fresh air supplied from the front by ventilation is provided. Because it is in contact with dense flue gas with a small dilution ratio, it is possible to reliably detect the occurrence of flue gas and start the range hood accurately.

  In addition, the front side gas sensor receives the combustion exhaust gas from the gas stove and the air diluted with fresh air supplied from the front side by ventilation, resulting in both the ventilation amount and the combustion exhaust gas amount. An output corresponding to the gas concentration depending on the is obtained.

  Therefore, by controlling the set air volume based on the output of the front side gas sensor, it is possible to suppress the occurrence of excessive or insufficient ventilation, and appropriate ventilation can be performed.

  That is, according to the present invention, it is possible to suppress the gas sensor from receiving a strong flow of combustion exhaust gas, and to suppress a decrease in sensitivity due to oil smoke or the like adhering to the detection part of the gas sensor. Thus, it is possible to realize a range hood capable of accurately detecting combustion exhaust gas with a small dilution ratio by fresh air, accurately linking the gas stove and the range hood, and accurately performing the automatic ventilation operation.

  Further, when the front gas sensor and the rear gas sensor having a predetermined sensitivity to hydrogen are used, the automatic ventilation operation can be performed more accurately according to the concentration of the combustion exhaust gas.

  Further, when the control unit is configured to stop the blowing means when the gas concentration detected by the rear gas sensor is equal to or lower than the predetermined gas concentration during operation of the blower, a gas such as a gas stove is used. When using cooking equipment, when the gas cooking equipment is extinguished, the exhaust gas from the gas cooking equipment (gas not diluted with fresh air) does not reach the rear gas sensor in a short time. Since the gas concentration detected by the side gas sensor (or the output corresponding to the gas concentration) is likely to be greatly reduced, it becomes possible to detect fire extinguishing of the gas stove quickly and accurately and stop the blowing means. A range hood capable of performing automatic ventilation operation more accurately can be obtained.

  In addition, automatic ventilation operation is more appropriately configured by updating the set air volume based on the weighted values of the gas concentrations obtained by the front gas sensor and the rear gas sensor and the set air volume. It is possible to realize a range hood capable of performing the above.

It is principal part side sectional drawing of the range hood concerning embodiment of this invention. It is a principal part front sectional view of the range hood concerning the embodiment of the present invention. It is a schematic block diagram of the gas sensor used in the range hood concerning embodiment of this invention. It is a block diagram of the control part with which the range hood concerning the embodiment of the present invention is provided. It is a figure which shows reaction of the gas sensor when the gas stove (gas cooking appliance) installed under the range hood concerning embodiment of this invention is burned.

  Hereinafter, the embodiment of the present invention will be shown and the features thereof will be described in more detail.

The range hood 1 according to the present embodiment is used together with gas cooking appliances such as a gas stove and a gas grill, and as shown in FIGS. 1 and 2, a rear wall W that is a wall on the back side as viewed from the front. The casing 10 to be installed, the blower 40, a control unit (not shown), a front gas sensor 5 (5a), and a rear gas sensor 5 (5b) are provided. Specifically, the rear wall surface W described above is, for example, a wall surface of a kitchen.
In addition, the following embodiment demonstrates the range hood 1 used with the gas stove which is a residue cooking appliance.

  The casing 10 has a ventilation path 4 inside and a hood portion 3. The hood part 3 has a suction port 41 that is an upstream end of the ventilation path 4, and fulfills a function of collecting the gas rising from below and sucking it from the suction port 41. In addition, the hood part 3 is arrange | positioned under the casing main body 2 with which the casing 10 is provided.

  The hood portion 3 has a flat rectangular parallelepiped shape (rectangular box shape) that is short in the vertical direction, and has a structure in which the opening on the lower surface side functions as the suction port 41 and the ventilation path 4 is formed inside. Which is connected to the casing body 2 at the top plate 31.

The ventilation path 4 is formed from the hood part 3 to the casing body 2, and the main part of the space in the casing 10 constitutes the ventilation path 4.
In the range hood 1 according to the present embodiment, the casing 10 includes the casing body 2 and the hood portion 3, but is not particularly limited to such a configuration.

A partition wall 32 is provided in the hood 3, and the ventilation path 4 and the wiring path 33 are partitioned by the partition wall 32.
The inner peripheral surface 32 a of the partition wall 32 constitutes the inner peripheral surface 4 a of the ventilation path 4.

  And the operation part 11 (FIG. 1) which sets ON / OFF of the air blower 40, setting air volume, etc. manually is provided in the front-end surface of the food | hood part 3. As shown in FIG. Moreover, the illumination 12 (FIG. 2) is provided in the food | hood part 3. As shown in FIG. A wiring (not shown) connected to the operation unit 11 and the illumination 12 is configured to be disposed in the wiring path 33.

  A blower device 40 including, for example, a sirocco fan is provided in an area of the ventilation path 4 located in the casing body 2. A duct 42 is provided on the downstream side of the blower 40 in the ventilation path 4 located in the casing body 2, and the downstream end portion (upper end in FIGS. 1 and 2) of the duct 42 is the ventilation path 4. A discharge port 43 is formed.

  Further, an extension exhaust duct (not shown) is connected to the discharge port 43 so that gas is discharged to the outside (outdoor).

  Moreover, the range hood 1 according to the present embodiment includes a control unit 100 (see FIG. 4).

  As shown in FIG. 4, the control unit 100 is a microcomputer 100a, a front gas sensor detection circuit 105a that is a detection circuit for the front gas sensor 5 (5a), and a rear that is a detection circuit for the rear gas sensor 5 (5b). A side gas sensor detection circuit 105b, a temperature sensor detection circuit 106, an operation switch board 107, a motor control circuit 108, a fan motor 109 for driving a fan included in the blower 40, and the like. It is comprised so that various control may be performed. Note that various known devices can be used as appropriate as the control unit 100 and peripheral devices associated therewith, and there is no particular limitation on the configuration thereof.

  As the blower device 40, for example, a fan including a fan such as a sirocco fan and a driving unit such as a motor for driving the fan is preferably used, but various known devices can be used as appropriate, and are particularly limited. Is not to be done. The amount of air blown from the blower 40 is controlled by the control unit 100, and specifically, driving means such as a motor is controlled. The blown amount per unit time may be directly detected by a known detection means. Moreover, it may be estimated from the rotation speed of the fan, and may be configured to be estimated from one or both of the current and voltage of the driving means.

  The detected or estimated airflow data is transmitted to the control unit 100. The air volume data may be analog data such as voltage and current applied from the detection means to the control unit 100, or digital data.

  The control unit 100 obtains the blowing amount from the transmitted blowing amount data. For example, when the so-called raw data of the blown air amount is transmitted, the control unit 100 obtains the blown air amount by an arithmetic function having one function based on the raw data. However, various specific processes in the control are conceivable and are not particularly limited.

  The control unit 100 performs feedback control based on the data of the air flow rate so that the actually detected air flow rate matches the set air flow rate (hereinafter referred to as the set air flow rate). In addition, control of the ventilation volume by the control part 100 is not limited to feedback control, Control by systems, such as feedforward control, may be sufficient. In other words, the method for controlling the air flow rate may be any method as long as the actual air flow rate is controlled to fall within a predetermined error range with respect to the set air flow rate.

The front gas sensor 5 (5a) and the rear gas sensor 5 (5b) detect the concentration of a specific type of gas in the atmosphere (hereinafter referred to as gas concentration). In the present embodiment, the gas sensor 5 is Two (plural) gas sensors including the above-described front side gas sensor 5 (5a) and the rear side gas sensor 5 (5b) are provided.
In addition, in the range hood 1 of this invention, it should just be provided with the two gas sensors of the above-mentioned front side gas sensor 5 (5a) and back side gas sensor 5 (5b), and is not limited to two pieces. .

  As shown in FIG. 1, the front gas sensor 5 (5a) is a position on the front side of the hood portion 3 and is retracted from the inner peripheral surface 4a of the ventilation path 4 by a predetermined dimension (5 mm in the present embodiment). It is arrange | positioned in the position so that the ventilation path 4 may be faced. Specifically, it arrange | positions so that the ventilation path 4 may be faced from the through-hole 132a for the front side gas sensor 5 (5a) provided in the partition 32 which comprises the internal peripheral surface 4a of the ventilation path 4. FIG.

  The rear gas sensor 5 (5b) is a position on the rear side of the hood portion 3 (position close to the rear wall surface W), and has a predetermined dimension (5 mm in this embodiment) from the inner peripheral surface 4a of the ventilation path 4. It is arrange | positioned so that the ventilation path 4 may be faced in the position which only retired. Specifically, the air passage 4 is arranged as desired from the through hole 132b for the rear gas sensor 5 (5b) provided in the partition wall 32 constituting the inner peripheral surface 4a of the air passage 4.

  In FIG. 2, the rear gas sensor 5 (5b) is shown, but the front gas sensor 5a (FIG. 1) is not shown.

  FIG. 3 shows an equivalent circuit of the gas sensor 5 (5a, 5b) used in the range hood 1 according to the present embodiment.

The gas sensor 5 (5a, 5b) used in the range hood 1 of the present embodiment is a semiconductor gas sensor, and has a detection unit 51 having a resistance R _S and a resistance R _L as shown in FIG. A resistance unit 52 connected in series with the detection unit 51, a detection unit 51 connected in series, and an application unit (not shown) for applying a predetermined voltage V _C (V) to both ends of the resistance unit 52; The heating part 53 for maintaining the part 51 at predetermined | prescribed temperature, and the measurement part 55 which measures the voltage _VO (V) of the both ends of the resistance part 52 are provided.

Furthermore, the heating unit 53 has a resistance R _H, the predetermined heat is generated in the resistance R _H by a predetermined voltage V _H (V) is applied to both ends of the resistor R _H. Thereby, it becomes easy to maintain the temperature of the detection unit 51 at a predetermined temperature. For convenience, the resistance value of the resistor R _S is represented by the same symbol as R _S (Ω), and the resistor R _L is represented by the same symbol as R _L (Ω).
The resistance R _S of the detection unit 51 is a variable resistance whose resistance value R _S changes with the gas concentration.

Here, in examining the range hood 1 of the present embodiment including the two gas sensors, the front gas sensor 5 (5a) and the rear gas sensor 5 (5b), first, the range hood including only one gas sensor. Consider the case.
When the range hood includes only one gas sensor 5, the resistance value R _S is expressed by the following equation (1).
R _S = {(V _C −V _O ) / V ₀ } × R _L (1)

On the other hand, the range hood 1 of the present embodiment includes two gas sensors, the front side gas sensor 5 (5a) and the rear side gas sensor 5 (5b), and thus each of the gas sensors 5 (5a, 5b). The apparent resistance value R _S obtained by synthesizing the two gas sensors 5 (5a, 5b) from the voltage V _O (V _Oa , V _Ob ) measured by the measuring unit 55 is obtained from the above equation (1). I have to. This point will be described later.
In addition, it means that it is in a state with high gas concentration, so that the value of _RS obtained by Formula (1) is small.

The front side gas sensor 5 (5a) and the rear side gas sensor 5 (5b) used in the range hood 1 of the present embodiment are configured so that the gas concentration (specific atmosphere in the atmosphere with respect to the entire atmosphere) The resistance value R _S of the detection unit 51 changes according to the gas ratio), and the voltage V _O (V _Oa , V _Ob ) measured by the measurement unit 55 changes. Note that the front gas sensor 5 (5a) and the rear gas sensor 5 (5b) used in the range hood 1 of the present embodiment have a predetermined sensitivity to the combustion exhaust gas.

  However, specific gases for detecting combustion exhaust gas include, for example, hydrogen, ethanol, isobutane, carbon monoxide, but are not limited thereto.

  Moreover, the front side gas sensor 5 (5a) used in the range hood 1 of this embodiment is a type 1 gas sensor shown in Table 1, and is combustible in city gas or LP gas such as hydrogen and isobutane. It has a predetermined sensitivity to gas.

  Further, the rear gas sensor 5 (5b) used in the range hood 1 of the present embodiment is also a type 1 gas sensor shown in Table 1 and is combustible in city gas or LP gas such as hydrogen and isobutane. It has a predetermined sensitivity to gas.

  As described above, the two gas sensors used in the range hood 1 according to the present embodiment, that is, the front gas sensor 5 (5a) and the rear gas sensor 5 (5b) are gas sensors having the same characteristics. .

  In addition, in the range hood 1 concerning this embodiment, although the semiconductor gas sensor is used as the gas sensor 5, the gas sensor which can be used in this invention is not limited to a semiconductor gas sensor, Various gas sensors are used suitably. It is possible to use.

  The detected gas concentration data is transmitted to the control unit 100. In the present embodiment, the concentration data transmitted to the control unit 100 is a voltage (analog data) applied from the measurement unit 55 of the gas sensor 5 to the control unit 100. The gas concentration is obtained by a calculation function as a function. Note that the data transmitted to the control unit 100 may not be analog data but may be digital data converted based on voltage, and there is no particular restriction on the type thereof. In any case, the control unit 100 can finally obtain the gas concentration from the transmitted concentration data.

In the range hood 1 according to the present embodiment, the control unit 100 newly sets the set air volume based on the gas concentration and the set air volume obtained from the front gas sensor 5 (5a) and the rear gas sensor 5 (5b). That is, the set air volume is configured to be updated.
A predetermined range of the set air volume is appropriately set by the range hood 1 and always includes OFF (stop state) as a lower limit, that is, an air volume of 0 (m ³ / h), and an upper limit is appropriately set.

  The set air volume may be configured to be able to be set continuously between the upper limit and the lower limit, or may be configured to be set in stages. Furthermore, it may be configured such that a part can be set continuously and the rest can be set stepwise.

  The set air volume is updated at predetermined intervals, but the set air volume is preferably updated at as short an interval as possible (ultimately continuously). However, there is no special restriction on the update mode. For example, a condition for updating may be separately determined, and the update may be performed when the condition is satisfied.

  Next, the update of the set air volume in the range hood 1 of the present embodiment including two gas sensors, the front gas sensor 5 (5a) and the rear gas sensor 5 (5b), will be described in more detail.

In the present embodiment, as described above, the concentration data of the specific gas detected by the front gas sensor 5 (5a) and the rear gas sensor 5 (5b) is measured by each measurement unit of each gas sensor 5 (5a, 5b). The voltage V _O (V _Oa , V _Ob ) measured at 55.

Specifically, the apparent output voltage V _O is _divided into a voltage V _Oa (corresponding to V _O in FIG. 3) measured by the measurement unit 55 of the front gas sensor 5 (5a), and the rear gas sensor 5 (5b). From each of the voltages V _Ob (corresponding to V _O in FIG. 3) measured by the measuring unit 55, the following equation (2):
V _O = V _Oa + V _Ob (2)
Ask more.

Then, the apparent resistance value R _S is expressed by the above equation (1):
R _S = {(V _C −V _O ) / V _O } × R _L (1)
Ask for.
The smaller the value of R _S obtained by Equation (1), the higher the gas concentration.

The voltages V _Oa and V _Ob are predetermined values when the gas concentration is 0, and the resistance value R _{S at} this time is a predetermined value. This value is set as a reference resistance value R _SO . The reference resistance value R _SO and other values (resistance value R _S , resistance value R _L, etc.) differ depending on the front side gas sensor 5 (5a) and the rear side gas sensor 5 (5b), but the range according to the present embodiment. In the hood 1, values corresponding to the gas sensors 5 (5 a, 5 b) are stored in a storage device such as a ROM (Read Only Memory) attached to the control unit 100.

In this embodiment, the rate of change K (%) is defined as an index indicating the apparent gas concentration detected by the front gas sensor 5 (5a) and the rear gas sensor 5 (5b). The change rate K is expressed by the following formula (3).
K = {(R _SO −R _S ) / R _SO } × 100 (3)
Note that the rate of change K obtained by Equation (3) is a value from 0 to 100, and the greater the rate of change K, the higher the detected gas concentration.

Rate of change K is a one-to-one correspondence with the resistance value R _S apparent, one-to-one with the gas concentration of the apparent resistance R _S of the apparent rear side gas sensor 5 and the front side gas sensor 5 (5a) to (5b) is detected Therefore, the change rate K has a one-to-one correspondence with the apparent gas concentration detected by the gas sensor 5 (5a, 5b), and changes as the apparent gas concentration detected by the gas sensor 5 (5a, 5b) increases. The rate K increases.

  Therefore, the control described below is based on the rate of change K, and although the apparent gas concentrations detected by the front gas sensor 5 (5a) and the rear gas sensor 5 (5b) do not appear directly, In addition, it can be said that the control is performed based on the gas concentrations detected by the front gas sensor 5 (5a) and the rear gas sensor 5 (5b).

Table 1 shows gas types to be detected in the type 1 gas sensor used as the front side gas sensor 5 (5a) and the rear side gas sensor 5 (5b), and the type 2 and type 3 gas sensors as reference gas sensors. The relationship between the type, the concentration (ppm) of each gas in each gas sensor, and the apparent resistance value R _S and the reference resistance value R _SO (ie, R _S / R _SO ) is illustrated.

The values shown in Table 1 are obtained for each of the front side gas sensor 5 (5a) and the rear side gas sensor 5 (5b), and the output voltages V _Oa and V _Ob are obtained for each of these output voltages V _Oa and V _Ob . The above formula (1):
R _S = {(V _C −V _O ) / V ₀ } × R _L (1)
R _S / R _SO obtained individually by the above, in other words, for the front side gas sensor 5 (5a), R _Sa / R _SOa obtained from V _Oa and for the rear side gas sensor 5 (5b), obtained from V _Ob R _Sb / R _SOb is shown.

  A blank in Table 1 indicates that the gas sensor of the corresponding type is not a detection target because the sensitivity to the gas is low.

  In the range hood 1 according to the present embodiment, the front gas sensor 5 (5a) has the characteristics shown in the type 1 column, and the rear gas sensor 5 (5b) also has the characteristics shown in the type 1 column. Although it has, it is not limited to this, You may use the gas sensor which shows another characteristic as the front side gas sensor 5 (5a) and the back side gas sensor 5 (5b).

  As described above, the range hood 1 according to the present embodiment is configured to be able to update the set air volume. Specifically, the gas concentration (corresponding to the rate of change K) and the setting at a certain point in time are set. The control unit 100 is configured to update the set air volume used thereafter from the air volume. The certain time point is, of course, a time point before the update of the set air volume, but is preferably immediately before the update time.

  The update of the set air volume preferably has a tendency that the set air volume after the update becomes larger as the gas concentration becomes higher than the predetermined set air volume before the update. That is, although not shown in particular, when the gas concentration is taken on the X axis and the updated set air volume is taken on the Y axis with respect to a predetermined set air volume before the update, a relationship line between the gas concentration and the updated set air volume is obtained. However, it is preferable that the so-called right shoulder rises.

  The aspect in which the relationship line rises to the right may be an aspect in which the Y value continuously increases (monotonically increases) as the X value increases, and there is a horizontal portion in part and other portions are It may be a mode of increasing continuously or a mode of increasing stepwise. In addition, this invention does not exclude the aspect in which the process to reduce in part exists for some reason when the Y value increases as the X value increases.

As the gas concentration increases, the air volume (m ³ / h) required for promptly discharging the air containing the detected gas increases, so it is preferable to increase the set air volume after the update as described above.

  Further, it is preferable that the set air volume is updated as the set air volume after the update increases as the set air volume before the update increases with respect to the predetermined gas concentration. That is, although not particularly illustrated, when the set air volume before update is taken on the X axis and the set air volume after update is taken on the Y axis for a predetermined gas concentration, the set air volume before update−the set air volume after update It is preferable that the relationship line rises so-called right.

  Further, the manner in which the above relationship line rises to the right is similar to the above-described relationship line between the gas concentration and the updated set air volume, and the Y value continuously increases (monotonically increases) as the X value increases. ), A part having a horizontal part and another part continuously increasing, or an aspect increasing stepwise. Note that the present invention does not exclude an aspect in which there is a step of decreasing in part for some reason when the Y value increases as a whole as the X value increases.

  Normally, regardless of the gas concentration, when the set air volume before update is large, the desired set air volume after update becomes large. Therefore, the larger the set air volume before update as described above, the greater the set air volume after update. Is preferably increased.

  In the range hood 1 according to the present embodiment, the set air volume is updated as shown in Table 2, for example.

That is, from the rate of change K shown in the upper part of Table 2 (which increases as the gas concentration increases) and the set air volume before update (m ³ / h) shown in the left column, the corresponding set air volume after update (m ³ / H) is set and updated. In the present embodiment, the stage of change in the set air volume (the stage of the set air volume after the update) is 7 stages of 0 (OFF), 150, 200, 250, 300, 400, 500 (m ³ / h).

  In the range hood 1 according to the present embodiment, as shown in Table 2, the set air volume after update tends to increase as the rate of change K increases with respect to each set air volume before update. I understand.

  In particular, this tendency exists even when the set air volume before update is 0. In this case, when the gas concentration exceeds the first threshold, the set air volume after the update exceeds 0.

<Linking with gas stove>
FIG. 5 shows the reaction of the front gas sensor 5 (5a) and the rear gas sensor 5 (5b) when the gas stove is burned to boil hot water. In FIG. 5, a state where the value of R _S / R _O is small represents a state where the gas concentration is high. Note that R _O is the resistance (reference resistance) of the detection unit 51 when the concentration of the target gas is zero. Further, the resistance R _S of the detection unit 51 decreases as the gas concentration increases. Therefore, the state where R _S / R _O is small indicates that the gas concentration is high.

In FIG. 5, after the start of combustion of the gas stove (burner), the rear side gas sensor 5 (5b) shows a quick reaction, whereas the front side gas sensor 5 (5a) has a slow reaction. This is because the mixed gas of combustion exhaust gas and fresh air reaches the front side gas sensor 5 (5a), whereas the rear side gas sensor 5 (5b) is disposed at a deep position, and is caused by fresh air. It is considered that the rear side gas sensor 5 (5b) reacted more quickly than the front side gas sensor 5 (5a) because a high concentration flue gas having a low degree of dilution arrives.
In addition, after the combustion of the gas stove (burner) is stopped, it is understood that the output tends to greatly decrease in the rear side gas sensor 5 (5b) in which high-concentration combustion exhaust gas having a low degree of dilution by fresh air has arrived. .

  In the range hood 1 according to the present embodiment, for example, when cooking is performed using a gas stove, the first concentration is set so that the concentration (gas concentration) of the gas to be detected reaches a predetermined value (this is the first threshold). The threshold value is set.

  Even when the blower 40 of the range hood 1 is stopped, if the rate of change K exceeds the value of the rate of change K corresponding to the gas concentration of the first threshold (10 in this embodiment), the range hood One air blower 40 is configured to start driving. Thereby, when cooking with a gas stove is performed and the gas concentration exceeds the first threshold, the blower 40 of the range hood 1 can be automatically driven.

  In this way, when the air blower 40 of the range hood 1 is automatically driven, the gas stove and the range hood 1 are not communicated with each other by wire or wireless, and the gas stove is the same manufacturer or predetermined model as the range hood 1. Therefore, the range hood 1 and the gas stove can be linked (that is, the blower 40 of the range hood 1 is automatically driven), which is meaningful.

Even when the set air volume before update is larger than 0 and smaller than the predetermined value, the set air volume after update is set to 0 when the gas concentration is equal to or lower than the second threshold value. In the present embodiment, when the set air volume is stepwise, the set air volume before the update is greater than 0, and the minimum set air volume is 150 (m ³ / h), the rate of change K is the second threshold value. When it is 5 or less, the set air volume after update is set to 0 (see Table 2).

  For example, when cooking with a gas stove, a particularly large air volume is not required, but when the range hood 1 is driven with a set air volume larger than 0 and smaller than a predetermined value in order to discharge the generated flue gas, the gas stove When cooking by is completed, no combustion exhaust gas is generated, and the driving of the range hood 1 becomes unnecessary.

Therefore, even when the set air volume before update is a predetermined value larger than 0 (in this embodiment, 150 (m ³ / h)), the change rate K corresponds to the gas concentration of the second threshold value. When the rate of change K is equal to or less than the value (5 in this embodiment), the driving of the blower 40 of the range hood 1 is stopped.

  Thereby, when cooking by a gas stove is complete | finished, gas concentration will be below a 2nd threshold value, and it will become possible to stop the air blower 40 of the range hood 1 automatically.

  As described above, when the blower 40 of the range hood 1 is automatically stopped, the gas stove and the range hood 1 do not communicate with each other by wire or wirelessly, and the gas stove is the same manufacturer or a predetermined model as the range hood 1. In addition, the range hood 1 and the gas stove can be linked (that is, the air blower 40 of the range hood 1 is automatically stopped) without being necessary, which is significant.

  In the case of the range hood 1 according to the present embodiment, the front gas sensor 5 (5a) and the rear gas sensor 5 (5b) both have a predetermined sensitivity to hydrogen. It is possible to realize a range hood capable of performing an automatic ventilation operation in accordance with the concentration of a specific gas in the combustion exhaust gas generated during use.

  In the present embodiment, when the range hood 1 is stopped, the range hood 1 can be accurately started by detecting the combustion gas generated from the gas stove during cooking by the rear gas sensor 5 (5b).

  Further, the front side gas sensor 5 (5a) receives combustion exhaust gas from a gas stove and the like and air diluted with fresh air supplied from the front side by ventilation, resulting in ventilation amount and combustion exhaust gas. An output corresponding to the gas concentration depending on both the quantity can be obtained. Therefore, by controlling the set air volume according to the output of the front side gas sensor 5 (5a), it becomes possible to suppress the occurrence of excessive or insufficient ventilation, and appropriate ventilation can be performed.

  That is, in the range hood 1 of the present embodiment, the front side gas sensor 5 (5a) and the rear side gas sensor 5 (5b) are provided by being retracted from the ventilation path 4 by a predetermined dimension, so that the gas sensor 5 (5a 5b) can suppress the flow of combustion exhaust gas from being strongly received, and it is possible to suppress a decrease in sensitivity due to oil smoke or the like adhering to the detection part of the gas sensor 5 (5a, 5b), and the rear side gas sensor. 5 (5b) makes it possible to reliably detect combustion exhaust gas with a small dilution ratio with fresh air, and to properly perform automatic ventilation operation by properly linking the gas stove and the range hood.

In the present embodiment, as described above, the apparent output voltage V _O is expressed by the above-described equation (2):
V _O = V _Oa + V _Ob (2)
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Thereafter, the apparent resistance value R _S is expressed by the above formula (1):
R _S = {(V _C −V _O ) / V _O } × R _L (1)
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Then, the rate of change K (%) is defined as an index indicating the apparent gas concentration, and the rate of change K is expressed by the above equation (3):
K = {(R _SO −R _S ) / R _SO } × 100 (3)
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On the other hand, coefficients ka and kb for weighting the output voltage V _{Oa of} the front side gas sensor 5 (5a) and the output voltage V _Ob of the rear side gas sensor 5 (5b) are determined respectively, and the apparent output voltage V _{O is determined.} With the following formula (4):
V _O = ka · V _Oa + kb · V _Ob (4)
Further, the apparent resistance value R _S is obtained by the above-described formula (1):
R _S = {(V _C −V _O ) / V _O } × R _L (1)
After that, the rate of change K (%) is defined as an index indicating the apparent gas concentration, and the rate of change K is expressed by the above equation (3):
K = {(R _SO −R _S ) / R _SO } × 100 (3)
In other words, the set air volume is updated based on the weighted value and the set air volume obtained from the gas concentrations obtained from the front gas sensor 5 (5a) and the rear gas sensor 5 (5b). The weighting coefficients ka and kb are set so as to satisfy ka <kb, and the output of the rear gas sensor 5 (5b) is mainly used during the operation of the blowing means 40. As an alternative, the blowing means 40 may be stopped.

  By comprising in this way, the range hood 1 which can perform an automatic ventilation driving | running | working more appropriately can be provided.

  Further, during operation of the air blowing means 40, when the gas concentration detected by the rear gas sensor 5 (5b) is equal to or lower than a predetermined stop gas concentration (that is, the output of the rear gas sensor 5 (5b) is predetermined). It is also possible to configure the control unit 100 to stop the blowing means 40 when the output is equal to or less than the stop output.

In such a configuration, as shown in FIG. 5, when the gas stove is extinguished, the output (R _S / R ₀ ) of the rear gas sensor 5 (5b) is likely to be greatly reduced. Can be stopped and the air blowing means 40 can be stopped, so that the range hood 1 capable of performing the automatic ventilation operation more accurately can be obtained.

  In the above embodiment, the case where cooking is performed using a gas stove has been described as an example. However, the present invention is not limited to a gas stove. For example, the present invention is similarly applied to the case where other gas cooking equipment such as a gas grill is used. Is possible.

  The present invention is not limited to the above embodiment in other points, and various modifications can be made within the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Range hood 2 Casing main body 3 Hood part 4 Ventilation path 4a Inner peripheral surface of a ventilation path 5 Gas sensor 5a Front side gas sensor 5b Rear side gas sensor 10 Casing 11 Operation part 12 Illumination 31 Top plate 32 Partition 32a Inner peripheral surface 33 of partition Passage 40 Blowing device 41 Suction port 42 Duct 43 Discharge port 51 Detection unit 52 Resistance unit 53 Heating unit 55 Measurement unit 132a Front side gas sensor through hole 132b Rear side gas sensor through hole W Rear wall surface

Claims (4)

A casing that has a ventilation path inside and is installed on the rear wall surface that is the wall surface on the back side when viewed from the front,
A hood portion configured to have a suction port serving as an upstream end of the ventilation path, collect gas rising from below, and suck the gas from the suction port;
A blowing means provided in the ventilation path;
A control unit for controlling the blowing means,
The set air volume is configured to be able to be set continuously or stepwise from an air volume of 0 to an appropriately set upper air volume, and
A range hood configured such that the control unit controls the blower so that the amount of gas blown by the blower becomes the set air volume,
A plurality of gas sensors for detecting the concentration of a specific type of gas contained in the gas flowing through the ventilation path;
Each of the plurality of gas sensors has a predetermined sensitivity to combustion exhaust gas,
At least one of the plurality of gas sensors, as a front side gas sensor, faces the ventilation path at a position on the front side of the hood portion and retracted by a predetermined dimension from the inner peripheral surface of the ventilation path. Arranged,
At least one of the plurality of gas sensors, as a rear gas sensor, faces the ventilation path at a position on the rear side of the hood portion and retracted by a predetermined dimension from the inner peripheral surface of the ventilation path. Arranged,
The said control part is comprised so that the said setting air volume may be updated based on the gas concentration obtained from the said front side gas sensor and the said back side gas sensor, and the said setting air volume.   The range hood according to claim 1, wherein the front gas sensor and the rear gas sensor have a predetermined sensitivity to hydrogen.   During operation of the blower, the controller is configured to stop the blower when the gas concentration detected by the rear gas sensor is equal to or lower than a predetermined stop gas concentration. 3. The range hood according to claim 1 or 2, characterized in that:   The set air volume is configured to be updated based on a weighted value of each gas concentration obtained by the front gas sensor and the rear gas sensor and the set air volume. Range food.

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