CN115682046A - Dry burning prevention device and control method of kitchen range - Google Patents

Abstract

The invention discloses an anti-dry burning device and a control method of a stove, wherein the anti-dry burning device comprises: the electromagnetic valve is used for controlling the opening and closing of the cooker; the thermocouple is used for sensing the temperature of the bottom of a cooker placed on the cooker; the power supply is a voltage-variable power supply with adjustable voltage; the electromagnetic valve, the thermocouple and the power supply are connected in sequence to form an anti-dry heating loop, and the difference between the power supply voltage and the thermoelectric potential generated by the thermocouple provides starting voltage for the electromagnetic valve. The voltage-adjustable variable-voltage power supply is arranged, so that a user can change the preset flameout temperature by adjusting the output voltage of the power supply in the using process to adapt to different cooking conditions, the anti-dry-burning function of the anti-dry-burning device can be suitable for cookers with different heat conductivity coefficients and different cooking food materials, and the using effect of the user is enhanced.

Description

Dry burning prevention device and control method of kitchen range

Technical Field

The invention relates to the technical field of kitchen utensils, in particular to an anti-dry-burning device, and particularly relates to a control method of a stove.

Background

Gas cookers are an indispensable part of daily life of people, and the gas cookers are kitchen appliances heated by direct fire using gas fuel such as liquefied petroleum gas, artificial gas, natural gas, and the like. The gas stove is called a stove plate, the popularization degree of the gas stove is unknown, and a passing concept is difficult to see. Such as a firewood range, a kerosene stove, a briquette stove, etc. Gas stoves are mainly classified into liquefied gas stoves, and natural gas stoves, depending on the source of the gas. According to the range, the range is divided into a single range, a double range and a multi-range.

The gas-cooker is comparatively convenient when using, and is economical and practical, and the air pollution that can effectual less dust granule caused compares with traditional coal kitchen. The gas stove is clean and energy-saving, is generally used in household life at present, but the safety of the gas stove in use is generally concerned all the time, people need to pay attention to the combustion condition of the gas stove all the time, such as water burning and the like, the phenomenon that gas is still released due to the fact that a gas valve is forgotten to be closed or gas is extinguished due to negligence of people in the use process, the gas stove can heat a cooker for a long time, water in the cooker is burnt out due to long-time heating, the cooker is burnt out if the water is dried, fire disasters can be caused if the water is burnt out if the water is light, and leaked gas can also threaten the safety of lives and properties of people.

Along with social development, the living standard of people is improved, safety consciousness in life is continuously strengthened, flameout protection of the gas stove is used as a necessary safety use measure of the gas stove, the dry burning prevention gas stove is affected by the fact that a dry burning prevention technology is not mature enough, and the market share is not high.

The flameout set temperature of the existing dry-burning prevention gas stove cannot be adjusted, so that the problem that the dry-burning prevention gas stove is flameout mistakenly due to the fact that different food materials are cooked and different pots used for cooking the food materials are caused.

The present invention has been made in view of this situation.

Disclosure of Invention

The invention aims to overcome the defects in the prior art, provides an anti-dry heating device and solves the problem that the preset flameout temperature cannot be adjusted in the conventional anti-dry heating device.

In order to solve the technical problems, the invention adopts the technical scheme that the basic concept is as follows:

an anti-dry heating device, comprising:

the electromagnetic valve is used for controlling the opening and closing of the cooker;

the thermocouple is used for sensing the temperature of the bottom of a pot placed on the stove;

the power supply is a variable voltage power supply with adjustable voltage;

the electromagnetic valve, the thermocouple and the power supply are connected in sequence to form an anti-dry heating loop, and the difference between the power supply voltage and the thermoelectric potential generated by the thermocouple provides starting voltage for the electromagnetic valve.

Furthermore, the negative pole of the thermocouple and the negative pole of the power supply are connected with each other, and the electromagnetic valve is connected in series on a loop between the positive pole of the thermocouple and the positive pole of the power supply.

Furthermore, a first voltmeter is connected in parallel at two ends of the thermocouple and used for detecting thermoelectric force generated by the thermocouple;

or, the two ends of the electromagnetic valve are connected in parallel with a second voltmeter for detecting the voltages at the two ends of the electromagnetic valve;

preferably, the power supply is provided with a detection means for detecting an output voltage thereof.

And the positive pole of the thermistor is connected to a loop between the electromagnetic valve and the positive pole of the thermocouple, and the negative pole of the thermistor is connected with the negative pole of the power supply to form a rapid flameout loop.

Further, the negative electrode of the power supply is connected with a switching device, and the negative electrode of the power supply is selectively connected with the negative electrode of the thermocouple or the negative electrode of the thermistor through the switching device.

Further, the switching device is a travel switch, including:

the shell is hollow, and the top and the bottom of the shell are respectively provided with corresponding openings;

the hollow shaft penetrates through the shell from an opening on the shell and is circumferentially positioned with the shell;

the first fixed contact is arranged on the top of the shell and is communicated with the outside of the shell;

the second stationary contact is arranged on the side wall of the shell and is communicated with the outside of the shell;

the movable contact is arranged on the hollow shaft, radially and outwards extends from the periphery of the hollow shaft, and is driven by the hollow shaft to be selectively communicated with the first stationary contact or the second stationary contact.

Furthermore, the first fixed contact penetrates through the top wall of the shell and extends towards the interior of the shell, the first fixed contact is fixedly connected with the top wall of the shell, and the distance between one end, away from the hollow shaft, of the movable contact and the side wall of the shell is smaller than the distance between the first fixed contact and the inner wall of the shell;

the second stationary contact penetrates through the side wall of the shell and extends towards the inside of the shell, the second stationary contact is in circumferential limit connection with the shell, the distance between one end of the movable contact far away from the hollow shaft and the side wall of the shell is less than or equal to the distance between the second stationary contact and the inner wall of the shell,

preferably, one end of the second stationary contact arranged in the shell is connected with a contact piece, the contact piece extends from the lower part of the first stationary contact to the bottom of the shell, and the top end of the contact piece is gradually bent towards the inner wall of the shell;

a return spring is sleeved on the second stationary contact, one end of the return spring is abutted with the contact piece, and the other end of the return spring is abutted with the inner wall of the shell; one end of the second stationary contact arranged outside the shell is provided with a limiting protrusion which is limited with the shell.

Further, the openings comprise a first opening and a second opening which are respectively arranged at the top and the bottom of the shell and have decreasing diameters; the hollow shaft comprises a first part and a second part, and the first part and the second part of the hollow shaft are respectively matched with the first opening and the second opening;

an elastic component is arranged between the first part of the hollow shaft and the bottom wall of the shell, a radial protrusion which is limited with the top wall of the shell is further arranged on the first part of the hollow shaft, the moving contact is arranged at the bottom end of the first part of the hollow shaft, and the axial distance between the radial protrusion and the moving contact is smaller than or equal to the distance of the first fixed contact extending into the shell.

Furthermore, the thermocouple is fixed on the top of the hollow shaft, at least part of the thermocouple protrudes out of the top surface of the hollow shaft, the positive pole of the thermocouple penetrates through the bottom of the hollow shaft through a lead and is connected with the electromagnetic valve, and the negative pole of the thermocouple penetrates through the bottom of the hollow shaft through a lead and is connected with the second stationary contact from the outside of the connecting shell;

a through hole is formed in the hollow shaft between the movable contact and the radial protrusion, and the negative electrode of the power supply penetrates through the through hole from the bottom of the hollow shaft through a lead and is connected with the movable contact;

the negative electrode of the thermistor is connected with the first stationary contact from the outside of the shell through a lead;

preferably, the travel switch is installed at the center of the burner, and the top of the hollow shaft of the travel switch extends upwards out of the burner.

The second purpose of the invention is to provide a control method of a stove, wherein the stove is provided with the dry burning prevention device, and the following technical scheme is adopted:

when placing the pan on the cooking utensils, auto-change over device switches to first state: the negative electrode of the power supply is connected with the negative electrode of the thermocouple, and the electromagnetic valve, the thermocouple and the power supply are sequentially connected to form an anti-dry heating loop;

when not placing the pan on the cooking utensils, auto-change over device switches to the second state: the negative pole of the power supply is connected with the negative pole of the thermistor, and the electromagnetic valve, the thermistor and the power supply are sequentially connected to form a rapid flameout loop.

After adopting the technical scheme, compared with the prior art, the invention has the following beneficial effects:

the voltage-adjustable variable-voltage power supply is arranged, so that a user can change the preset flameout temperature by adjusting the output voltage of the power supply in the use process to adapt to different cooking conditions, the anti-dry-burning function of the anti-dry-burning device can be suitable for cookers with different heat conductivity coefficients and different cooking food materials, and the use effect of the user is enhanced.

According to the invention, the dry burning prevention loop and the quick flameout loop are arranged, so that the power supply and the electromagnetic valve can be selectively connected to the dry burning prevention loop or the quick flameout loop, and the dry burning prevention device can simultaneously realize the dry burning prevention function and the quick flameout function.

According to the invention, the travel switch is arranged, so that when a cooker is placed on the cooker, the hollow shaft moves downwards under the pressure of the cooker, the movable contact on the hollow shaft is contacted with the second stationary contact, at the moment, the power supply, the electromagnetic valve and the thermocouple are mutually connected to form an anti-dry burning loop, the thermoelectric force generated by the thermocouple is gradually increased along with the rise of the temperature of the bottom of the cooker, the voltage acting on two ends of the electromagnetic valve is gradually reduced, when the voltage acting on two ends of the electromagnetic valve is lower than the critical voltage for maintaining the opening of the electromagnetic valve, the electromagnetic valve is closed, the gas stove is flameout, and the anti-dry burning function is realized; when a cooker is not placed on the cooker, the hollow shaft moves upwards under the elastic force of the elastic element to enable the movable contact on the hollow shaft to be in contact with the first fixed contact, at the moment, the power supply, the electromagnetic valve and the thermistor are connected with each other to form a quick flameout loop, current in the loop passes through the thermistor, the thermistor is gradually increased by the thermistor, voltage acting on two ends of the electromagnetic valve is gradually reduced, when the voltage acting on two ends of the electromagnetic valve is lower than critical voltage for maintaining the opening of the electromagnetic valve, the electromagnetic valve is closed, the gas cooker is flameout, and the quick flameout function is achieved.

According to the invention, the mechanical travel switch is arranged, so that the dry burning prevention device is sensitive to control and high in precision when the dry burning prevention loop and the quick flameout loop are directly switched; the contact piece is arranged, so that the contact between the movable contact and the second contact is more reliable.

Meanwhile, the invention has simple structure and obvious effect and is suitable for popularization and use.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without limiting the invention to its proper form. It is obvious that the drawings in the following description are only some embodiments, and that for a person skilled in the art, other drawings can be derived from them without inventive effort. In the drawings:

FIG. 1 is a schematic view of the structure of the dry burning prevention device of the present invention;

FIG. 2 is a schematic structural diagram of an anti-dry heating device provided with a first voltmeter according to the present invention;

FIG. 3 is a schematic view of the principle of the structure of the dry combustion preventing device with a second voltmeter according to the present invention;

FIG. 4 is a schematic view of the structure of an anti-dry heating device according to another embodiment of the present invention;

fig. 5 is a schematic structural view of the travel switch of the present invention.

Description of the main elements in the figures:

1. a thermocouple; 101. a first thermocouple; 102. a second thermocouple; 2. an electromagnetic valve; 3. a power source; 4. a thermistor; 5. a travel switch; 501. a first stationary contact; 502. a second stationary contact; 5021. a limiting protrusion; 5022. a return spring; 5023. a contact piece; 503. a movable contact; 504. a housing; 5041. a first opening; 5042. a second opening; 505. a hollow shaft; 5051. a first portion; 5052. a second portion; 5053. a through hole; 5054. a radial projection; 506. an elastic element; 6. a first voltmeter; 7. a second voltmeter; 8. and a third voltmeter.

It should be noted that the drawings and the description are not intended to limit the scope of the inventive concept in any way, but to illustrate it by a person skilled in the art with reference to specific embodiments.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and the following embodiments are used for illustrating the present invention and are not intended to limit the scope of the present invention.

In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted" and "connected" are to be construed broadly, e.g., as being fixed or detachable or integrally connected; can be mechanically or electrically connected; may be directly connected or indirectly connected through an intermediate. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Example one

As shown in fig. 1 to 2, an embodiment of the present invention discloses an anti-dry heating device, which includes a thermocouple 1 for sensing a temperature of a bottom of a pot placed on a cooker, the thermocouple 1 is an electronic component that generates a thermal electromotive force (thermoelectromotive force), which is a thermal potential, when heated, and includes a detection end and a free end, the detection end of the thermocouple 1 contacts with the bottom of the pot and senses the temperature of the bottom of the pot, and the free end of the thermocouple 1 generates a thermoelectric force proportional to the temperature of the detection end. The free end of the thermocouple 1 is connected with a power supply 3 and the electromagnetic valve 2 through a lead to form an anti-dry heating loop, the opening and closing actions of the electromagnetic valve 2 are used for controlling the communication and the cut-off of a gas pipeline, and the difference between the voltage of the power supply 3 and the thermoelectric potential generated by the thermocouple 1 provides starting voltage for the electromagnetic valve 2.

Preferably, in this embodiment, the negative electrode of the thermocouple 1 and the negative electrode of the power supply 3 are connected with each other, the electromagnetic valve 2 is connected in series on a loop between the positive electrode of the thermocouple 1 and the positive electrode of the power supply 3, the positive electrode of the power supply 3 and the positive electrode of the electromagnetic valve 2 are connected through a lead, and the negative electrode of the electromagnetic valve 2 and the positive electrode of the thermocouple 1 are connected through a lead, so that the voltage received by the electromagnetic valve 2 is a difference value obtained by subtracting a thermoelectric force generated at the free end of the thermocouple 1 from the output voltage of the power supply 3.

Preferably, in this embodiment, a valve core is disposed in the electromagnetic valve 2, and the positive and negative electrodes of the electromagnetic valve 2 receive voltage and form electromagnetic force for controlling the opening of the electromagnetic valve 2 inside the electromagnetic valve 2; a spring for keeping the spool of the solenoid valve 2 closed is also provided inside the solenoid valve 2. When the electromagnetic force borne by the valve core of the electromagnetic valve 2 is greater than the spring force borne by the valve core of the electromagnetic valve 2, the electromagnetic valve 2 is opened to realize ventilation of the gas stove; when the electromagnetic valve 2 is not under voltage or the electromagnetic force generated by the voltage applied to the electromagnetic valve 2 is smaller than the elastic force of the spring in the electromagnetic valve 2, the electromagnetic valve 2 is closed to realize the gas cutoff of the gas stove; when the electromagnetic force generated by the voltage applied to the electromagnetic valve 2 is equal to the elastic force of the spring inside the electromagnetic valve 2, the electromagnetic valve 2 is in the critical state of opening, and the voltage applied to the electromagnetic valve 2 is referred to as the opening critical voltage of the electromagnetic valve 2. Since the elastic force of the spring inside the solenoid valve 2 is a fixed value, the electromagnetic force required to open the solenoid valve 2 is a fixed value, that is, the opening threshold voltage of the solenoid valve 2 is a fixed value.

In the embodiment, the thermocouple 1 is installed on a burner of a cooker, wherein the thermocouple 1 is arranged at the center of the burner, and the detection end of the thermocouple 1 extends upwards out of the burner to be in contact with the bottom of the cooker. Initially, the temperature of the pot is low, the thermoelectric force generated by the free end of the thermocouple 1 is small, and the output voltage of the power supply 3 counteracts the thermoelectric force of the free end of the thermocouple 1 and then provides the electromagnetic valve 2 with voltage for maintaining the opening of the electromagnetic valve 2; along with the rise of the temperature of the cooker, the thermoelectric potential generated at the free end of the thermocouple 1 is gradually increased, the difference value of the thermoelectric potential is subtracted from the output voltage of the power supply 3, namely, the voltage applied between the positive electrode and the negative electrode of the electromagnetic valve 2 is gradually reduced, when the temperature of the bottom of the cooker rises to a certain magnitude, the voltage applied to the two ends of the electromagnetic valve 2 is smaller than the opening critical voltage of the electromagnetic valve 2, the electromagnetic force applied to the valve core by the electromagnetic valve 2 is smaller than the elastic force of the spring in the electromagnetic valve 2, the electromagnetic valve 2 is closed, and the gas stove is cut off and flameout.

Preferably, in this embodiment, the temperature of the bottom of the pot when the gas stove is extinguished is the extinguishing temperature.

Preferably, in this embodiment, the power supply 3 is a variable voltage power supply 3 with adjustable voltage. Since the opening critical voltage of the electromagnetic valve 2 is a fixed value, when the output voltage of the power supply 3 changes and the electromagnetic valve 2 is closed, the upper limit value of the thermoelectric force generated at the free end of the thermocouple 1 changes, that is, the upper limit value of the temperature at the position (that is, the bottom of the pot) detected by the detection end of the thermocouple 1 changes, that is, the flameout temperature changes.

In this embodiment, the extinction temperature increases as the output voltage of the power supply 3 increases. Through setting up power 3 into output voltage size adjustable vary voltage power 3, make the user in the use, can change predetermined flame-out temperature through adjusting power 3's output voltage to adapt to different culinary art conditions, make the dry combustion method prevention function of preventing dry combustion method device can be applicable to the different pans of coefficient of heat conductivity and different culinary art materials, reinforcing user's result of use.

Preferably, in this embodiment, a first voltmeter 6 is connected in parallel to two ends of the thermocouple 1, and is configured to detect a thermoelectric force generated at a free end of the thermocouple 1 in real time; the power supply 3 is provided with a detection unit for detecting the output voltage thereof. Therefore, the convenience of a user can adjust the output voltage of the power supply 3 according to the heat conductivity coefficient of the cooker and different food materials in the cooking process, the dry burning prevention device is prevented from being flamed out by mistake, and the using effect of the user is further enhanced.

Example two

As shown in fig. 3, the present embodiment is different from the first embodiment in that a second voltmeter 7 is connected in parallel to two ends of the solenoid valve 2 for detecting a difference between the output voltage of the power supply 3 and the thermoelectric voltage generated by the thermocouple 1, that is, a voltage value received by the solenoid valve 2.

EXAMPLE III

As shown in fig. 4, in the present embodiment, the dry-heating preventing device includes a first thermocouple 101 for sensing the temperature of the bottom of a pot placed on the hob and a second thermocouple 102 for sensing the temperature of flame generated at the top of the hob.

First thermocouple 101 and second thermocouple 102 are the electronic component that produces the thermoelectromotive force promptly to generate the electric potential by heating, first thermocouple 101 and second thermocouple 102 all include sense terminal and free end, wherein the sense terminal of first thermocouple 101 and second thermocouple 102 is used for the response temperature change, the free end of first thermocouple 101 and second thermocouple 102 produces and is the direct thermal potential with sense terminal temperature, the free end of first thermocouple 101 and second thermocouple 102 passes through wire interconnect, and connect power supply 3 and solenoid valve 2 and form the anti-dry combustion return circuit, the opening and the closed action of solenoid valve 2 are used for controlling gas pipeline intercommunication and cutting off.

In this embodiment, the first thermocouple 101 is disposed at the center of the burner, during cooking, the first thermocouple 101 is not burned by flame, and the detection end of the first thermocouple 101 extends upward and is used for contacting with the bottom of the pot to detect the temperature of the bottom of the pot, and as the temperature of the bottom of the pot gradually rises, the first thermoelectric force generated by the free end of the first thermocouple 101 gradually increases; the second thermocouple 102 is arranged at a flame port close to the burner, and during cooking, the detection end of the second thermocouple 102 is directly burned by flame, and the second thermoelectric voltage generated by the free end of the second thermocouple 102 is constant due to stable flame temperature.

In this embodiment, the cathodes of the first thermocouple 101 and the second thermocouple 102 are connected to each other, and the anode of the second thermocouple 102 is connected to the cathode of the power supply 3, i.e. the total electromotive force between the anodes of the first thermocouple 101 and the second thermocouple 102 is the second thermoelectric force minus the first thermoelectric force. The positive pole of the electromagnetic valve 2 is connected with the positive pole of the power supply 3, the negative pole of the electromagnetic valve 2 is connected with the positive pole of the first thermocouple 101, and an anti-dry heating loop is formed, namely, the voltage applied to the two ends of the electromagnetic valve 2 is the difference between the second thermoelectric potential and the first thermoelectric potential plus the output voltage of the power supply 3.

Because the opening critical voltage of the electromagnetic valve 2 is a fixed value and the magnitude of the second thermoelectric force is constant, as the temperature of the bottom of the cooker placed on the gas stove rises, the first thermoelectric force generated by the free end of the first thermocouple 101 gradually increases, the difference between the second thermoelectric force generated by the second thermocouple 102 and the first thermoelectric force generated by the free end of the first thermocouple 101 gradually decreases, namely the total electromotive force generated by the second thermocouple 102 and the first thermocouple 101 decreases, so that the voltage acting on the electromagnetic valve 2 gradually decreases as the temperature of the position detected by the first thermocouple 101 rises, when the temperature of the bottom of the cooker rises to a certain magnitude, the voltage applied to the electromagnetic valve 2 is smaller than the opening critical voltage of the electromagnetic valve 2, the electromagnetic valve 2 is closed, the gas stove is cut off, and the cooker is flameout, and the temperature of the bottom of the cooker is flameout temperature when the cooker is flameout.

Since the opening threshold voltage of the electromagnetic valve 2 is a fixed value and the magnitude of the second thermoelectric force generated by the free end of the second thermocouple 102 is constant, when the output voltage of the power supply 3 changes and the electromagnetic valve 2 is closed, the upper limit value of the first thermoelectric force generated by the free end of the first thermocouple 101 changes, that is, the upper limit value of the temperature at the position detected by the detection end of the thermocouple 1 (i.e., the bottom of the pot) changes, that is, the flameout temperature changes.

In this embodiment, when the output voltage of the power supply 3 is reduced and the electromagnetic valve 2 is closed, the upper limit value of the temperature of the position detected by the detection end of the first thermocouple 101 is reduced, that is, the flameout temperature is reduced; when the output voltage of the power supply 3 increases and the electromagnetic valve 2 is closed, the upper limit value of the temperature at the position detected by the detection end of the first thermocouple 101 increases, that is, the extinction temperature increases.

Therefore, use the cooking utensils to cook the in-process, the user can be according to different pans and different edible materials, adjusts power 3's output voltage to certain size to the temperature maximum value that can reach at the bottom of the pan when changing solenoid valve 2 and closing, flame-out temperature promptly, when reaching this temperature at the bottom of the pan, solenoid valve 2 is automatic closed, thereby prevents to cause the condition emergence of pan dry combustion method because of user's negligence, improves the security.

The opening and closing of the electromagnetic valve 2 are controlled by the thermal potential difference of the second thermocouple 102 and the first thermocouple 101 and the output voltage of the power supply 3, so that the on-off of a gas pipeline is controlled, the stove is controlled to be flamed out, the characteristics of the thermocouple 1 are fully utilized, and the overall energy consumption of the device is small.

Preferably, in this embodiment, a third voltmeter 8 is connected in parallel to the positive electrode of the first thermocouple 101 and the positive electrode of the second thermocouple 102, and is used for detecting a difference value of thermoelectric potentials generated by the first thermocouple 101 and the second thermocouple 102. Therefore, the convenience of a user can adjust the output voltage of the power supply 3 according to the heat conductivity coefficient of the cooker and different food materials in the cooking process, the dry burning prevention device is prevented from being flamed out by mistake, and the using effect of the user is further enhanced.

Preferably, in this embodiment, the first thermocouple 101 and the second thermocouple 102 are made of the same material.

Preferably, in this embodiment, the output voltage of the power supply 3 is always smaller than the threshold voltage for opening the electromagnetic valve 2, so as to prevent the electromagnetic valve 2 from being opened by mistake under the action of the power supply 3, and thus, the gas leakage is prevented.

Example four

As shown in fig. 1 to 5, in this embodiment, the dry combustion preventing device is further provided with a fast flameout loop, a thermistor 4 is disposed on the fast flameout loop, and the power supply 3, the electromagnetic valve 2 and the thermistor 4 are connected in series to form the fast flameout loop. When the quick flameout loop is acted, the current in the quick flameout loop passes through the thermistor 4 and causes the thermistor 4 to generate heat, the thermistor 4 is gradually increased by the heating resistor, the voltage received by the electromagnetic valve 2 is gradually reduced, when the voltage at the two ends of the electromagnetic valve 2 is lower than the critical voltage for maintaining the opening state of the electromagnetic valve 2, the electromagnetic valve 2 is closed, the gas circuit is interrupted, and the dry combustion preventing device achieves the effect of quick flameout.

Preferably, in this embodiment, one end (positive electrode) of the thermistor 4 is connected to a loop between the negative electrode of the electromagnetic valve 2 and the positive electrode of the thermocouple 1 through a lead, and the other end (negative electrode) of the thermistor 4 is connected to the negative electrode of the power supply 3, so as to form a fast flameout loop.

In this embodiment, the negative electrode of the power supply 3 is selectively connected to the negative electrode of the thermocouple 1 or the negative electrode of the thermistor 4 through the switching device, so that the dry-heating preventing device has a fast flameout function. Therefore, the dry-burning prevention device can enable the gas stove to simultaneously realize the dry-burning prevention function and the quick flameout function, the dry-burning prevention loop and the quick flameout loop of the dry-burning prevention device jointly control the same electromagnetic valve 2, and the control system of the gas stove is simple without being controlled by a separate circuit.

Preferably, in the present embodiment, the switching device is a travel switch 5.

In this embodiment, the travel switch 5 includes a housing 504 having a hollow interior, and a hollow shaft 505 penetrating the housing 504, and the hollow shaft 505 is circumferentially limited from the housing 504. A first fixed contact 501 and a second fixed contact 502 which are communicated with the outside of the shell 504 are arranged on the inner wall of the shell 504, a movable contact 503 which moves synchronously with the hollow shaft 505 is arranged on the hollow shaft 505, and the movable contact 503 can selectively contact with the first fixed contact 501 or the second fixed contact 502 along with the axial movement of the hollow shaft 505.

In this embodiment, the top and the bottom of the casing 504 are respectively provided with corresponding openings, and the hollow shaft 505 penetrates the casing 504 from the opening on the casing 504 and is circumferentially positioned with the casing 504.

First stationary contact 501 is disposed on the top of casing 504, penetrates the top wall of casing 504, and extends toward the inside of casing 504; second stationary contact 502 is provided on a side wall of casing 504, penetrates a side wall of casing 504, and extends toward the inside of casing 504, and second stationary contact 502 and first stationary contact 501 are provided on the same side of casing 504. The movable contact 503 is disposed on the hollow shaft 505 and extends radially outward from the outer periphery of the hollow shaft 505, in this embodiment, the movable contact 503 extends toward a side where the first stationary contact 501 and the second stationary contact 502 are disposed, and a distance between one end of the movable contact 503, which is far away from the hollow shaft 505, and a side wall of the housing 504 is smaller than a distance between the first stationary contact 501 and an inner wall of the housing 504, so that when the hollow shaft 505 moves upward, the movable contact 503 is lapped on a lower end of the first stationary contact 501. Meanwhile, the distance between one end of the movable contact 503 away from the hollow shaft 505 and the side wall of the housing 504 is smaller than or equal to the distance between the second stationary contact 502 and the inner wall of the housing 504, so that the movable contact 505 can contact with the second stationary contact 502 when moving downwards.

Preferably, in this embodiment, the first stationary contact 501 is fixedly connected to the top wall of the housing 504; the second stationary contact 502 is circumferentially limited and connected with the housing 504, one end of the second stationary contact 502, which is arranged inside the housing 504, is connected with the contact piece 5023, the contact piece 5023 extends from the lower part of the first stationary contact 501 to the bottom of the housing 504, and the top end of the contact piece 5023 is gradually bent towards the inner wall of the housing 504, so that in the downward movement process of the hollow shaft 505, the end part of the movable contact 503, which is far away from one end of the hollow shaft 505, enters the contact area of the contact piece 5023 from the bent part at the top of the contact piece 5023, the movable contact 503 is prevented from being clamped with the top of the contact piece 5023, and the smoothness of the work of the travel switch 5 is improved.

In this embodiment, the sidewall of the housing 504 is further provided with a guide post which vertically corresponds to the second stationary contact 502 and is parallel to the second stationary contact, the guide post penetrates through the sidewall of the housing 504 and extends toward the inside of the housing 504, the guide post is movably connected with the sidewall of the housing 504, one end of the guide post, which is disposed outside the housing 504, is provided with a limit protrusion 5021 which is limited with the housing 504, and the guide post is disposed inside the housing 504 and connected to the contact piece 5023, so that the second stationary contact 502 is circumferentially limited with the housing 504.

Preferably, the distance between one end of the movable contact 503 away from the hollow shaft 505 and the side wall of the housing 504 is smaller than the distance between the second stationary contact 502 and the inner wall of the housing 504. In this embodiment, a return spring 5022 is sleeved on the second stationary contact 502, one end of the return spring 5022 abuts against the contact piece 5023, the other end of the return spring 5022 abuts against the inner wall of the housing 504, and a limit protrusion 5021 which is limited with the housing 504 is arranged at one end of the second stationary contact 502 which is arranged outside the housing 504, so that when the movable contact 503 contacts with the contact piece 5023, the end of the movable contact 503, which is far away from one end of the hollow shaft 505, enters the contact area of the contact piece 5023 from the bent part at the top of the contact piece 5023, the movable contact 503 continues to move downwards to press the contact piece 5023, so that the return spring 5022 is compressed, and under the elastic force action of the return spring 5022, the contact piece 5023 is in close contact with the movable contact piece 503, thereby ensuring the reliability of the contact between the movable contact piece 5023 and the movable contact piece 5023.

Preferably, in this embodiment, the openings include a first opening 5041 and a second opening 5042 of decreasing diameter, the first opening 5041 is disposed at the top of the housing 504, and the second opening 5042 is disposed at the bottom of the housing 504; the hollow shaft 505 includes first and second portions 5051, 5052, the first and second portions 5051, 5052 are coaxial and the second portion 5052 is formed at a lower end of the first portion 5051, and the first and second portions 5051, 5052 of the hollow shaft 505 cooperate with the first and second openings 5041, 5042, respectively.

An end surface of the first portion 5051 of the hollow shaft 505 adjacent to the second portion 5052 and the bottom of the housing 504 are provided with a resilient member to allow the movable contact 503 on the hollow shaft 505 to contact the first stationary contact 501. Preferably, the elastic component is a spring, which is sleeved on the second portion 5052 of the hollow shaft 505, the upper end of the spring abuts against the lower end face of the first portion 5051 of the hollow shaft 505, and the lower end of the spring abuts against the bottom wall of the housing 504; a radial protrusion 5054 which is limited with the top wall of the shell 504 is further arranged on the first part 5051 of the hollow shaft 505 and close to the lower end of the first part 5051, the movable contact 503 is fixed at the junction of the first part 5051 and the second part 5052 of the hollow shaft 505, and the axial distance between the radial protrusion 5054 and the movable contact 503 is smaller than or equal to the distance that the first fixed contact 501 extends into the shell 504, so that when the hollow shaft 505 moves upwards to the maximum position, the contact piece 5023 can be in close contact with the lower end of the first fixed contact 501, and the working reliability of the travel switch 5 is ensured.

In this embodiment, when the hollow shaft 505 is not under axial pressure, the spring is in a free state, the radial protrusion 5054 and the top wall of the housing 504 are limited, and the movable contact 503 is forced to press the first contact; when the hollow shaft 505 is pressed to move downwards, the spring is in a compressed state, the contact piece 5023 follows the hollow shaft 505 to move downwards, the end part of the contact piece 5023 far away from the hollow shaft 505 is abutted with the contact piece 5023, and the movable contact 503 is communicated with the second contact through the contact piece 5023.

Preferably, in this embodiment, the travel switch 5 is installed at the center of the burner, the top of the hollow shaft 505 of the travel switch 5 extends upward out of the burner, the top end of the hollow shaft 505 is closed, the thermocouple 1 is fixed on the top of the hollow shaft 505 and at least partially protrudes out of the top surface of the hollow shaft 505, the positive electrode of the thermocouple 1 passes through the bottom of the hollow shaft 505 through a conducting wire and is connected with the electromagnetic valve 2, the negative electrode of the thermocouple 1 passes through the bottom of the hollow shaft 505 through a conducting wire and is connected with the second stationary contact 502 from the outside of the connecting housing 504, a through hole 5053 is formed in the hollow shaft 505 between the movable contact 503 and the radial protrusion 5054, the negative electrode of the power supply 3 passes through the bottom of the hollow shaft 505 through the through hole 5053 through a conducting wire and is connected with the movable contact 503, and one end (negative electrode) of the thermistor 4, which is far away from the electromagnetic valve 2, is connected with the first stationary contact 501 from the outside of the housing 504 through a conducting wire.

In this embodiment, when a pot is placed on the cooker, the hollow shaft 505 moves downward under the pressure of the pot to make the movable contact 503 on the hollow shaft 505 contact with the second stationary contact 502, and at this time, the power supply 3, the electromagnetic valve 2 and the thermocouple 1 are connected with each other to form an anti-dry-burning loop, the thermoelectric force generated by the thermocouple 1 gradually increases with the temperature rise of the bottom of the cooker, the voltage acting on the two ends of the electromagnetic valve 2 gradually decreases, and when the voltage acting on the two ends of the electromagnetic valve 2 is lower than the critical voltage for maintaining the opening of the electromagnetic valve 2, the electromagnetic valve 2 is closed, the gas stove is turned off, and the anti-dry-burning function is realized; when no cooker is placed on the cooker, the hollow shaft 505 moves upwards under the elastic force of the elastic element 506, so that the movable contact 503 on the hollow shaft 505 is contacted with the first stationary contact 501, at the moment, the power supply 3, the electromagnetic valve 2 and the thermistor 4 are connected with each other to form a quick flameout loop, current in the loop passes through the thermistor 4, the thermistor 4 is gradually increased by the thermistor, voltage acting on two ends of the electromagnetic valve 2 is gradually reduced, when the voltage acting on two ends of the electromagnetic valve 2 is lower than the critical voltage for maintaining the opening of the electromagnetic valve 2, the electromagnetic valve 2 is closed, the gas cooker is flameout, and the quick flameout function is realized.

Through setting up mechanical form travel switch 5, make prevent dry combustion method device control sensitive, and the precision is higher when preventing dry combustion method return circuit and quick flame-out return circuit direct switch-over, simultaneously, establish ties through thermistor 4 and solenoid valve 2, power 3 and form quick flame-out return circuit, solve current prevent dry combustion method device when not placing the pan, the dry combustion method flame-out time receives the big problem of firepower size influence, prevents to appear because of the firepower is less, the condition that the cooking utensils are not put out of fire for a long time.

Preferably, in this embodiment, the housing 504 of the travel switch 5 is made of a high-temperature-resistant insulating material (e.g., ceramic), and the first stationary contact 501, the second stationary contact 502, and the moving contact 503 are all made of a hard conductive material (e.g., copper, iron, etc.).

Although the present invention has been described with reference to a preferred embodiment, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (10)

1. An anti-dry heating device, comprising:

the electromagnetic valve (2) is used for controlling the opening and closing of the cooker;

the method is characterized in that:

the thermocouple (1) is used for sensing the temperature of the bottom of a cooker placed on the cooker;

the power supply (3) is a voltage-adjustable variable voltage power supply (3);

the electromagnetic valve (2), the thermocouple (1) and the power supply (3) are sequentially connected to form an anti-dry heating loop, and the difference between the voltage of the power supply (3) and the thermoelectric potential generated by the thermocouple (1) provides an opening voltage for the electromagnetic valve (2).

2. The dry-heating preventing device according to claim 1, wherein: the negative pole of the thermocouple (1) and the negative pole of the power supply (3) are mutually connected, and the electromagnetic valve (2) is connected in series on a loop between the positive pole of the thermocouple (1) and the positive pole of the power supply (3).

3. The dry-heating preventing device according to claim 2, wherein: two ends of the thermocouple (1) are connected in parallel with a first voltmeter (6) for detecting thermoelectric force generated by the thermocouple (1);

or the two ends of the electromagnetic valve (2) are connected with a second voltmeter (7) in parallel and used for detecting the voltage at the two ends of the electromagnetic valve (2);

preferably, the power supply (3) is provided with a detection means for detecting an output voltage thereof.

4. The dry-heating preventing device according to any one of claims 1 to 3, wherein: the fast flameout circuit is characterized by further comprising a thermistor (4), wherein the positive electrode of the thermistor (4) is connected to a loop between the electromagnetic valve (2) and the positive electrode of the thermocouple (1), and the negative electrode of the thermistor (4) is connected with the negative electrode of the power supply (3) to form a fast flameout loop.

5. The dry-heating preventing device according to claim 4, wherein: the negative electrode of the power supply (3) is connected with a switching device, and the negative electrode of the power supply (3) is selectively connected with the negative electrode of the thermocouple (1) or the negative electrode of the thermistor (4) through the switching device.

6. The dry-heating preventing device according to claim 5, wherein:

the switching device is a travel switch (5) comprising:

the shell (504) is hollow, and the top and the bottom of the shell are respectively provided with corresponding openings;

a hollow shaft (505) extending through the housing (504) from an opening in the housing (504) and positioned circumferentially with respect to the housing (504);

a first stationary contact (501) which is provided on the top of the housing (504) and which is connected to the outside of the housing (504);

a second stationary contact (502) that is provided on a side wall of the housing (504) and that is connected to the outside of the housing (504);

and the movable contact (503) is arranged on the hollow shaft (505), radially and outwards extends from the outer periphery of the hollow shaft (505), and is selectively communicated with the first fixed contact (501) or the second fixed contact (502) under the driving of the hollow shaft (505).

7. The dry-heating preventing device according to claim 6, wherein: the first fixed contact (501) penetrates through the top wall of the shell (504) and extends towards the interior of the shell (504), and the distance between one end, away from the hollow shaft (505), of the movable contact (503) and the side wall of the shell (504) is smaller than the distance between the first fixed contact (501) and the inner wall of the shell (504);

the second fixed contact (502) penetrates through the side wall of the shell (504) and extends towards the interior of the shell (504), the second fixed contact (502) is in circumferential limit connection with the shell (504), and the distance between one end, away from the hollow shaft (505), of the movable contact (503) and the side wall of the shell (504) is smaller than or equal to the distance between the second fixed contact (502) and the inner wall of the shell (504);

preferably, one end of the second stationary contact (502) arranged in the housing (504) is connected with a contact piece (5023), the contact piece (5023) extends from the lower part of the first stationary contact (501) to the bottom of the housing (504), and the top end of the contact piece (5023) is gradually bent towards the inner wall of the housing (504);

a return spring (5022) is sleeved on the second stationary contact (502), one end of the return spring (5022) is abutted against the contact piece (5023), and the other end of the return spring is abutted against the inner wall of the shell (504).

8. The dry-heating preventing device according to claim 7, wherein: the openings comprise a first opening (5041) and a second opening (5042) which are respectively arranged at the top and the bottom of the shell (504) and have decreasing diameters; the hollow shaft (505) comprises a first portion (5051) and a second portion (5052), the first portion (5051) and the second portion (5052) of the hollow shaft (505) cooperating with the first opening (5041) and the second opening (5042), respectively;

an elastic component is arranged between the first part (5051) of the hollow shaft (505) and the bottom wall of the shell (504), the first part (5051) of the hollow shaft (505) is further provided with a radial protrusion (5054) limited with the top wall of the shell (504), the movable contact (503) is arranged at the bottom end of the first part (5051) of the hollow shaft (505), and the axial distance between the radial protrusion (5054) and the movable contact (503) is smaller than or equal to the distance of the first fixed contact (501) extending into the shell (504).

9. The dry-heating preventing device according to claim 8, wherein: the thermocouple (1) is fixed on the top of the hollow shaft (505) and at least partially protrudes out of the top surface of the hollow shaft (505), the positive pole of the thermocouple (1) penetrates through the bottom of the hollow shaft (505) through a lead and is connected with the electromagnetic valve (2), and the negative pole of the thermocouple (1) penetrates through the bottom of the hollow shaft (505) through a lead and is connected with the second stationary contact (502) from the outside of the connecting shell (504);

a through hole (5053) is formed in the hollow shaft (505) between the movable contact (503) and the radial protrusion (5054), and the negative electrode of the power supply (3) penetrates through the through hole (5053) from the bottom of the hollow shaft (505) through a lead and is connected with the movable contact (503);

the negative electrode of the thermistor (4) is connected with the first stationary contact (501) from the outside of the shell (504) through a lead;

preferably, the travel switch (5) is installed at the center of the burner, and the top of the hollow shaft (505) of the travel switch (5) protrudes upward out of the burner.

10. A control method of a cooker is characterized in that: the stove is provided with the dry burning prevention device of any one of the claims 5 to 9;

when placing the pan on the cooking utensils, auto-change over device switches to first state: the negative electrode of the power supply (3) is connected with the negative electrode of the thermocouple (1), and the electromagnetic valve (2), the thermocouple (1) and the power supply (3) are sequentially connected to form an anti-dry heating loop;

when not placing the pan on the cooking utensils, auto-change over device switches to the second state: the negative electrode of the power supply (3) is connected with the negative electrode of the thermistor (4), and the electromagnetic valve (2), the thermistor (4) and the power supply (3) are sequentially connected to form a rapid flameout loop.

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