A capacitive humidity sensor and a cooking device

Abstract

The present invention discloses a capacitive humidity sensor and a cooking device. The humidity sensor includes a housing, a first electrode and a second electrode. The first electrode and the second electrode are arranged side by side and spaced apart on the housing. Further included are a driving unit, a control unit and a display unit. The driving unit is arranged on the housing, and its output end is connected to the first electrode and / or the second electrode. The control unit is electrically connected to the driving unit and the display unit respectively, and is used to control the movement of the first electrode and / or the second electrode through the driving unit. In the capacitive humidity sensor of the present invention, by controlling the translational movement of the first electrode and / or the second electrode and calculating the humidity value according to the translational distance, the humidity value can be accurately detected. In addition, through the display unit, it is convenient for the user to intuitively judge the change of humidity.

Description

Technical Field

[0001] The present invention relates to the technical field of cooking appliances, and particularly to a capacitive humidity sensor and a cooking appliance. Background Art

[0002] During the process of cooking food by a cooking appliance, the evaporation rate of the moisture in the food increases with the increase of temperature, and the humidity in the cavity changes greatly. The cooking state of the food can be reflected by humidity detection, so as to meet the needs of intelligent cooking and the need for precise humidity control.

[0003] Existing humidity sensors usually first calculate the capacitance value, and then obtain the absolute humidity value according to the capacitance value and the absolute humidity table. For such a humidity sensor, the equivalent distance between the electrodes and the coupling area are fixed and unchanged, and users cannot intuitively judge the humidity change situation according to the equivalent distance or the coupling area. Summary of the Invention

[0004] The present invention aims to solve at least one of the problems existing in the related art to some extent. For this purpose, the present invention provides a capacitive humidity sensor, which accurately detects the humidity value in the area where the capacitive humidity sensor is located through the equivalent distance or deflection angle between the first electrode and the second electrode, and at the same time facilitates users to intuitively judge the humidity change situation.

[0005] The present invention also provides a cooking appliance with the capacitive humidity sensor.

[0006] According to the above-provided capacitive humidity sensor, it is realized by the following technical solutions:

[0007] A capacitive humidity sensor includes a housing, a first electrode and a second electrode. The first electrode and the second electrode are arranged side by side and spaced apart on the housing. A driving unit, a control unit and a display unit are further included. The driving unit is arranged on the housing, and its output end is connected to the first electrode and / or the second electrode. The control unit is electrically connected to the driving unit and the display unit respectively, and is used to control the movement of the first electrode and / or the second electrode through the driving unit. The display unit is used to display the deflection angle θ or the translation distance d1 of the first electrode and / or the second electrode.

[0008] In some embodiments, the first electrode and the second electrode form a coplanar capacitor.

[0009] In some embodiments, the output end of the driving unit is connected to the second electrode, and is used to drive the translational movement of the second electrode or to drive the second electrode to rotate around the first electrode; alternatively, the output end of the driving unit is connected to the first electrode, and is used to drive the translational movement of the first electrode or to drive the first electrode to rotate around the second electrode.

[0010] In some embodiments, the driving unit includes a first driving unit and a second driving unit. The first driving unit is electrically connected to the control unit and its output end is connected to the first electrode, and is used to control the translational movement of the first electrode; the second driving unit is electrically connected to the control unit and its output end is connected to the second electrode, and is used to control the translational movement of the second electrode.

[0011] In some embodiments, the driving unit includes a first driving unit and a second driving unit. The first driving unit is electrically connected to the control unit and its output end is connected to the first electrode, and is used to control the rotation of the first electrode; the second driving unit is electrically connected to the control unit and its output end is connected to the second electrode, and is used to control the rotation of the second electrode.

[0012] According to a cooking device provided above, it is achieved through the following technical solutions:

[0013] A cooking device includes an inner container, an evaporator and a main controller. The steam outlet of the evaporator is communicated with the inner container. Further included is the capacitive humidity sensor as described above. The capacitive humidity sensor is installed on the inner container and is used to detect the real-time humidity value of the inner container. The main controller is electrically connected to the evaporator and the capacitive humidity sensor respectively, and the main controller is used to control the working state of the evaporator at least according to the detected real-time humidity value and the preset humidity target value.

[0014] In some embodiments, the main controller is used to control the working state of the evaporator according to the detected real-time humidity value, preset humidity target value, lower limit humidity value and upper limit humidity value.

[0015] In some embodiments, a water pump is further included. The water inlet of the water pump is communicated with tap water or a water tank, and the water outlet of the water pump is communicated with the water injection port of the evaporator. The main controller is electrically connected to the water pump.

[0016] In some embodiments, a temperature sensor is further included. The temperature sensor is installed inside the inner container and is used to detect the real-time temperature of the inner container. The main controller is electrically connected to the temperature sensor.

[0017] Compared with the prior art, the present invention has at least the following beneficial effects:

[0018] 1. The capacitive humidity sensor of the present invention realizes accurate detection of the humidity value by controlling the translational movement of the first electrode and / or the second electrode and calculating the humidity value according to the translational distance.

[0019] 2. The capacitive humidity sensor of the present invention realizes accurate detection of the humidity value by controlling the rotation of the first electrode and / or the second electrode and calculating the humidity value according to the deflection angle.

[0020] 3. By setting the display unit, it is convenient for users to intuitively judge the change of humidity according to the translational distance or humidity value of the second electrode, improving the user experience. Description of the Drawings

[0021] Figure 1 is a partial structural schematic diagram of the capacitive humidity sensor in the dry air state in Embodiment 1 of the present invention;

[0022] Figure 2 is a connection block diagram of the capacitive humidity sensor in Embodiment 1 of the present invention;

[0023] Figure 3 is a partial structural schematic diagram of the capacitive humidity sensor in the wet air state in Embodiment 1 of the present invention;

[0024] Figure 4 is a relationship diagram between the movement of the second electrode and the humidity display key in the display unit in Embodiment 1 of the present invention;

[0025] Figure 5 is a relationship diagram between the movement of the second electrode and the dashboard in the display unit in Embodiment 2 of the present invention;

[0026] Figure 6 is a connection block diagram of the capacitive humidity sensor in Embodiment 3 of the present invention;

[0027] Figure 7 is a structural schematic diagram of the cooking device in Embodiment 4 of the present invention;

[0028] Figure 8 is a relationship diagram between the evaporator control and the absolute humidity of the inner container in Embodiment 4 of the present invention. Detailed Embodiments

[0029] The following embodiments illustrate the present invention, but the present invention is not limited by these embodiments. Modifying the specific embodiments of the present invention or equivalently replacing some technical features without departing from the spirit of the present invention shall be covered within the scope of the technical solutions claimed by the present invention.

[0030] Embodiment 1

[0031] SeeFigure 1-3 As shown in the figure, this embodiment provides a capacitive humidity sensor. The capacitive humidity sensor 1 includes a housing 11, a first electrode 12, a second electrode 13, a driving unit 14, and a control unit 15. The housing 11 is a sealed housing, and the first electrode 12 and the second electrode 13 are arranged side by side and spaced apart on the housing 11. The driving unit 14 is arranged on the housing 11, and its output end is connected to the first electrode 12 and / or the second electrode 13 for driving the movement of the first electrode 12 and / or the second electrode 13. The control unit 15 is electrically connected to the driving unit 14 for controlling the movement of the first electrode 12 and / or the second electrode 13 through the driving unit 14. Preferably, the first electrode 12 and the second electrode 13 form a coplanar capacitor, and the first electrode 12 serves as the positive plate and the second electrode 13 serves as the negative plate.

[0032] In this embodiment, taking the driving unit 14 driving the translational movement of the first electrode 12 and / or the second electrode 13 as an example, since the capacitance C = ε*S / d, ε = ε 空气 +α*ε 水 , d = d0 + d1; where ε is the dielectric constant of the air in the area where the capacitive humidity sensor 1 is located; ε 空气 is the dielectric constant of dry air, approximately 1; α is a coefficient; ε 水 is the dielectric constant of water, approximately 0.8; S is the area of the first electrode 12 or the second electrode 13; d is the equivalent distance between the first electrode 12 and the second electrode 13; d0 is the center distance between the central axes of the first electrode 12 and the second electrode 13 of the capacitive humidity sensor 1 in the dry air state (see Figure 1 ), and d1 is the translational distance of the translational movement of the second electrode 13 of the capacitive humidity sensor 1 in the wet air state (see Figure 3 ). Since the area S in this embodiment is a fixed value and the capacitance C is to be controlled to be a constant value, when the dielectric constant ε in the area where the capacitive humidity sensor 1 is located changes, that is, when the air humidity changes, the control unit 15 controls the translational movement of the first electrode 12 and / or the second electrode 13 through the driving unit 14, so that the equivalent distance d between the first electrode 12 and the second electrode 13 changes, and further the capacitance C remains unchanged.

[0033] It can be seen that the capacitive humidity sensor of the present embodiment drives the translational movement of the first electrode 12 and / or the second electrode 13 by controlling the driving unit 14, so that the equivalent distance between the first electrode 12 and the second electrode 13 changes, and the control unit 15 calculates the humidity value according to the translation distance d1 of the first electrode 12 and / or the second electrode 13, so as to accurately detect the humidity value of the area where the capacitive humidity sensor 1 is located. Compared with the existing capacitive humidity sensor, the capacitive humidity sensor of the present invention can realize the characterization of its humidity value by adjusting the distance between the electrodes, that is, the difference in humidity can be directly displayed through mechanical linkage.

[0034] In this embodiment, the driving unit 14 is a stepper motor, and the output end of the stepper motor is connected to the second electrode 13, and is used to drive the translational movement of the second electrode 13. In this way, it is convenient for the control unit 15 to drive the translational movement of the second electrode 13 through the driving unit 14 according to the change of the dielectric constant ε (i.e., air humidity), so that the capacitance C remains unchanged, and then the humidity value is calculated according to the translation distance d1 of the second electrode 13. Of course, in other embodiments, the output end of the driving unit 14 can also be connected to the first electrode 12, and the driving unit 14 is used to drive the translational movement of the first electrode 12.

[0035] Furthermore, a display unit 16 is also included, and the display unit 16 is electrically connected to the control unit 15, and is used to display the translation distance d1 of the second electrode 13. When the air humidity in the area where the capacitive humidity sensor 1 is located changes, the driving unit 14 drives the translation movement of the second electrode 13 to keep the capacitance C unchanged, and the translation distance d1 of the second electrode 13 can be directly displayed through the display unit 16, or the translation distance d1 is first converted into a humidity value and then displayed through the display unit 16. Therefore, through the display unit 16, it is convenient for the user to intuitively judge the change of humidity according to the translation distance d1 or the humidity value, thereby improving the user experience.

[0036] See also Figure 4 Specifically, a pointer 161 and a humidity display key 162 for roughly displaying the humidity are provided on the display unit 16, wherein the pointer 161 is connected to the pointer 161 through a transmission mechanism, and the humidity display key 162 includes low humidity, low humidity, medium humidity and high humidity display keys arranged in ascending order of humidity. When the capacitive humidity sensor is in a dry air state, the pointer 161 points to the low humidity display key; as the humidity in the area where the capacitive humidity sensor 1 is located increases, the stepper motor drives the second electrode 13 to move in translation, and the movement of the second electrode 13 can drive the pointer 161 to move through the transmission mechanism, so that the pointer 161 points to the corresponding display key, so that the user can intuitively judge the humidity in the area where the capacitive humidity sensor 1 is located through the pointing of the pointer 161.

[0037] The following will combine Figure 1 and Figure 3 to illustrate the working principle of the capacitive humidity sensor 1 in this embodiment:

[0038] Refer to Figure 1 , when the area where the capacitive humidity sensor 1 is located is in a dry air state, the electric field lines of the capacitor pass through the dry air from the first electrode 12 to the second electrode 13. Since the capacitance C = ε*S / d, and the area S is a fixed value, to maintain the capacitance C constant, the dielectric constant ε at this time is the dielectric constant of dry air, and correspondingly, the equivalent distance d is the center distance d0, and the pointer 161 of the display unit 16 points to the low humidity display key.

[0039] Refer to Figure 3 , when the area where the capacitive humidity sensor 1 is located is in a wet air state, since the capacitance C = ε*S / d, and the area S is a fixed value, the dielectric constant ε at this time is the dielectric constant of wet air. To keep the capacitance C unchanged, the control unit 15 controls the translational movement of the second electrode 13 through the driving unit 14 to change the equivalent distance d between the first electrode 12 and the second electrode 13, and the equivalent distance d is the sum of the center distance d0 and the translational distance d1. The pointer 161 of the display unit 16 points to any one of the corresponding low humidity, medium humidity, and high humidity display keys.

[0040] Embodiment 2

[0041] The difference between this embodiment and Embodiment 1 lies in the different movement modes of the second electrode 13. Specifically, the output end of the driving unit 14 is connected to the second electrode 13 and is used to drive the second electrode 13 to rotate around the first electrode 12, so that the position of the second electrode 13 deflects, and the deflection angle of the second electrode 13 is θ. Furthermore, the coupling area between the second electrode 13 and the first electrode 12 is changed. In this way, it is convenient for the control unit 15 to drive the rotation of the second electrode 13 through the driving unit 14 according to the change of air humidity, so as to maintain the capacitance C unchanged, and further calculate the humidity value according to the deflection angle θ of the second electrode 13. In other embodiments, the output end of the driving unit 14 can also be connected to the first electrode 12, and the driving unit 14 is used to drive the rotation of the first electrode 12.

[0042] Refer to Figure 5Specifically, a dashboard 163 similar to a car is provided on the display unit 16 for accurately displaying the humidity. The dashboard 163 is connected to the second electrode 13 through a transmission mechanism. An indicator needle and a displayed humidity value are provided on the dashboard 163. The displayed humidity value ∈ [low humidity, high humidity]. When the capacitive humidity sensor is in a dry air state, the indicator needle points to low humidity; as the humidity in the area where the capacitive humidity sensor 1 is located increases, the driving unit 14 drives the second electrode 13 to rotate, and the movement of the second electrode 13 can drive the indicator needle to deflect through the transmission mechanism, so that the user can intuitively judge the humidity in the area where the capacitive humidity sensor 1 is located according to the direction of the indicator needle.

[0043] It can be seen that by controlling the second electrode 13 to rotate around the first electrode 12, while ensuring that the equivalent distance d between the second electrode 13 and the first electrode 12 remains unchanged, the coupling area between the second electrode 13 and the first electrode 12 is changed, and the humidity level in the area where the capacitive humidity sensor 1 is located is intuitively displayed through the instrument panel 163 of the display unit 16.

[0044] Example 3

[0045] See also Figure 6 The difference between this embodiment and embodiment 1 or 2 is that the driving unit 14 includes a first driving unit 141 and a second driving unit 142. The first driving unit 141 is electrically connected to the control unit 15 and its output end is connected to the first electrode 12, and is used to drive the first electrode 12 to rotate or translate. The second driving unit 142 is electrically connected to the control unit 15 and its output end is connected to the second electrode 13, and is used to drive the second electrode 13 to rotate or translate.

[0046] Specifically, when the first driving unit 141 drives the first electrode 12 to move translationally, the second driving unit 142 drives the second electrode 13 to move translationally in a direction opposite to the movement direction of the first electrode 12, so that the first electrode 12 and the second electrode 13 move relative to each other; or, when the first driving unit 141 drives the first electrode 12 to rotate, the second driving unit 142 drives the second electrode 13 to rotate in a direction opposite to the movement direction of the first electrode 12, so that the first electrode 12 and the second electrode 13 rotate relative to each other.

[0047] It can be seen that the first driving unit 141 drives the first electrode 12 to rotate or translate, and the second driving unit 142 drives the second electrode 13 to rotate or translate, thereby realizing synchronous control of the movement of the first electrode 12 and the second electrode 13, and then realizing rapid adjustment of the equivalent distance d or coupling area between the first electrode 12 and the second electrode 13, and further improving the response time of the capacitive humidity sensor 1.

[0048] Example 4

[0049] See Figure 7 , this embodiment provides a cooking device, including an inner container 2, an evaporator 3, and a main controller (not shown in the figure). The steam outlet of the evaporator 3 is communicated with the inner container 2. It further includes a capacitive humidity sensor 1 as described in any one of Embodiments 1-3. The capacitive humidity sensor 1 is installed on the inner container 2 and is used to detect the real-time humidity value of the inner container 2. The main controller is electrically connected to the evaporator 3 and the capacitive humidity sensor respectively, and the main controller is used to control the working state of the evaporator 3 at least according to the detected real-time humidity value and the preset humidity target value. Thus, through the real-time humidity value detected by the capacitive humidity sensor 1 and the preset humidity target value, the working state of the evaporator 3 is accurately controlled, and then the humidity of the cooking ingredients is controlled, achieving the purpose of intelligent cooking and improving the cooking effect and cooking experience.

[0050] Preferably, the main controller is used to control the working state of the evaporator 3 according to the detected real-time humidity value, preset humidity target value, lower limit humidity value, and upper limit humidity value, where the lower limit humidity value < preset humidity target value < upper limit humidity value. See Figure 8 , when the cooking device starts to cook ingredients, the main controller controls the evaporator 3 to start working and deliver steam to the inner container 2. Under the action of the steam, the temperature and humidity of the inner container 2 increase. When the absolute humidity ρw of the inner container 2 rises to or approaches the upper limit humidity value, the main controller controls the evaporator 3 to stop working or stop delivering steam to the inner container 2; when the absolute humidity ρw of the inner container 2 drops to or approaches the lower limit humidity value, the main controller controls the evaporator 3 to start working again to continue delivering steam to the inner container 2. In this way, the absolute humidity ρw inside the inner container 2 is maintained within the fluctuation range of the preset humidity target value (i.e., between the lower limit humidity value and the upper limit humidity value). In this way, the accurate control of the absolute humidity ρw inside the inner container 2 within the fluctuation range of the preset humidity target value is realized, improving the cooking effect, and the intermittent operation of the evaporator 3 is realized, reducing the working load of the evaporator 3 and being beneficial to improving the service life of the evaporator 3.

[0051] See Figure 7 , specifically, it further includes a water pump 5. The water inlet of the water pump 5 is communicated with tap water or a water tank 6, and the water outlet of the water pump 5 is communicated with the water injection port of the evaporator 3. The main controller is electrically connected to the water pump 5. In this way, the main controller 5 can control the working state of the water pump 5 according to the water shortage situation of the evaporator 3 to realize the water injection or water replenishment for the evaporator 3 through the water pump 5 and the water tank 6, preventing the evaporator 3 from dry burning and further improving the service life of the evaporator 3.

[0052] In addition, it further includes a temperature sensor 7. The temperature sensor 7 is installed inside the inner container 2 and is used to detect the real-time temperature of the inner container 2. The main controller is electrically connected to the temperature sensor 7 and is used to adjust the heating power of the cooking device according to the real-time temperature of the inner container 2 to improve the cooking effect.

[0053] The above are only some embodiments of the present invention. For those of ordinary skill in the art, without departing from the inventive concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention.

Claims

1. A capacitive humidity sensor, comprising a housing (11), a first electrode (12) and a second electrode (13), wherein the first electrode (12) and the second electrode (13) are arranged side by side and spaced apart on the housing (11), characterized in that, It further includes a driving unit (14), a control unit (15) and a display unit (16). The driving unit (14) is arranged on the housing (11), and its output end is connected to the first electrode (12) and / or the second electrode (13). The control unit (15) is electrically connected to the driving unit (14) and the display unit (16) respectively, and is used to control the translational movement or rotational movement of the first electrode (12) and / or the second electrode (13) through the driving unit (14). The display unit (16) is used to display the translational distance d1 or the deflection angle θ of the first electrode (12) and / or the second electrode (13). Wherein, the capacitance C = ε*S / d, and d = d0 + d1; in the formula, ε is the dielectric constant of the air in the area where the capacitive humidity sensor is located, d is the equivalent distance between the first electrode (12) and the second electrode (13), d0 is the central distance between the central axes of the first electrode (12) and the second electrode (13) in the dry air state of the capacitive humidity sensor, and d1 is the translational distance of the translational movement of the first electrode (12) and / or the second electrode (13) in the wet air state of the capacitive humidity sensor. When the dielectric constant ε in the area where the capacitive humidity sensor is located changes, the control unit (15) controls the translational movement of the first electrode (12) and / or the second electrode (13) through the driving unit (14), so that the equivalent distance d between the first electrode (12) and the second electrode (13) changes, and further the capacitance C remains unchanged; or The driving unit (14) controls the position of the first electrode (12) and / or the second electrode (13) to deflect, and the deflection angle of the first electrode (12) and / or the second electrode (13) is θ. While ensuring that the equivalent distance d between the first electrode (12) and the second electrode (13) remains unchanged, the coupling area between the first electrode (12) and the second electrode (13) is changed, and further the capacitance C remains unchanged.

2. The capacitive humidity sensor according to claim 1, wherein The first electrode (12) and the second electrode (13) form a coplanar capacitor.

3. A capacitive humidity sensor according to claim 1 or 2, characterized in that, The output end of the driving unit (14) is connected to the second electrode (13), and is used to drive the translational movement of the second electrode (13) or to drive the second electrode (13) to rotate around the first electrode (12).

4. A capacitive humidity sensor according to claim 1 or 2, characterized in that, The output end of the driving unit (14) is connected to the first electrode (12), and is used to drive the translational movement of the first electrode (12) or to drive the first electrode (12) to rotate around the second electrode (13).

5. A capacitive humidity sensor according to claim 1 or 2, characterized in that, The driving unit (14) includes a first driving unit (141) and a second driving unit (142). The first driving unit (141) is electrically connected to the control unit (15), and its output end is connected to the first electrode (12) for controlling the translational movement of the first electrode (12). The second driving unit (142) is electrically connected to the control unit (15), and its output end is connected to the second electrode (13) for controlling the translational movement of the second electrode (13).

6. The capacitive humidity sensor according to claim 1 or 2, characterized in that, The driving unit (14) includes a first driving unit (141) and a second driving unit (142). The first driving unit (141) is electrically connected to the control unit (15), and its output end is connected to the first electrode (12) for controlling the rotation of the first electrode (12). The second driving unit (142) is electrically connected to the control unit (15), and its output end is connected to the second electrode (13) for controlling the rotation of the second electrode (13).

7. A cooking device, comprising an inner container (2), an evaporator (3) and a main controller, wherein an outlet of the evaporator (3) is communicated with the inner container (2), and is characterized in that, It further includes the capacitive humidity sensor according to any one of claims 1-6. The capacitive humidity sensor is installed on the inner container (2) for detecting the real-time humidity value of the inner container (2). The main controller is electrically connected to the evaporator (3) and the capacitive humidity sensor respectively, and the main controller is used to control the working state of the evaporator (3) at least according to the detected real-time humidity value and the preset humidity target value.

8. A cooking device according to claim 7, characterized in that, The main controller is used to control the working state of the evaporator (3) according to the detected real-time humidity value, preset humidity target value, lower limit humidity value and upper limit humidity value.

9. The cooking device according to claim 7, characterized in that, It further includes a water pump (5). The water inlet of the water pump (5) is communicated with tap water or a water tank (6), and the water outlet of the water pump (5) is communicated with the water injection port of the evaporator (3). The main controller is electrically connected to the water pump (5).

10. A cooking device according to claim 7, characterized in that, It further includes a temperature sensor (7). The temperature sensor (7) is installed inside the inner container (2) for detecting the real-time temperature of the inner container (2). The main controller is electrically connected to the temperature sensor (7).

Images