A safety type plasma stove

Abstract

The present invention discloses a safety type plasma stove, which includes a base, a burner head, and an electronic control unit. A plurality of discharge electrodes are arranged in the burner head, and a voltage transformation circuit unit is further arranged in the base and is electrically connected to the electronic control unit and the discharge electrodes; the electronic control unit is provided with a ground detection circuit and a total power leakage detection circuit. The ground detection circuit detects whether all the protective grounding points of the plasma stove are effectively grounded, and the total power leakage detection circuit is used to detect the difference between the current flowing into and out of the positive and negative electrodes of the electronic control unit to judge whether the plasma stove is leaking electricity; the ground detection circuit is electrically connected to the protective grounding wire in the three-wire plug; a liftable grounding device is further arranged in the burner head, and the liftable grounding device is provided with an elastically liftable protruding end for elastically contacting the bottom of the cookware. The present invention enables the plasma stove to perform the wok-tossing operation safely and has multiple protections of ground detection and leakage detection.

Description

Technical Field

[0001] The present invention relates to the technical field of cooking stoves, and particularly to a safety-type plasma stove. Background Art

[0002] Plasma, also known as ionized gas, is an ionized gaseous substance composed of positive and negative ions generated after some electrons are stripped from atoms and atomic groups. It is a macroscopic electrically neutral ionized gas with a scale larger than the Debye length. Its motion is mainly governed by electromagnetic forces and exhibits significant collective behavior. Plasma is a good conductor of electricity, and by using a cleverly designed magnetic field, plasma can be captured, moved, and accelerated. The development of plasma physics provides new technologies and processes for the further development of sciences such as materials, energy, information, environmental space, space physics, and geophysics. Plasma is the fourth state of matter different from solids, liquids, and gases. Matter is composed of molecules, molecules are composed of atoms, and atoms are composed of a positively charged atomic nucleus and negatively charged electrons orbiting around it. When heated to a high enough temperature or due to other reasons, the outer electrons break free from the bondage of the atomic nucleus and become free electrons, just like students running to the playground to play freely after class. When electrons leave the atomic nucleus, this process is called "ionization". At this time, the matter becomes a uniform "paste" composed of positively charged atomic nuclei and negatively charged electrons. Therefore, people jokingly call it ion plasma. The total amount of positive and negative charges in these ion plasmas is equal, so it is approximately electrically neutral and is called plasma.

[0003] A plasma stove is a new type of cooking stove that utilizes the characteristics of plasma, uses high voltage electricity to break down air to form thermal plasma, converts electrical energy into thermal energy, and finally obtains a thermal plasma beam with an ideal length and function, and generates a thermal plasma beam with flame-like characteristics to heat cookware for cooking.

[0004] Since a plasma stove uses electrical energy as the direct energy input, to generate a plasma beam, it is necessary to boost the mains voltage to a high voltage of about 10 KV. Under such a high working voltage, how to ensure the electrical safety of users and prevent electric shock accidents becomes a very important matter.

[0005] Currently, the plasma stoves on the market have the following defects:

[0006] 1. For safety reasons, currently, when users cook with a plasma stove, they cannot perform the wok-tossing operation (the "wok-tossing" refers to the cooking action of lifting the wok, leaving the cooking range, and repeatedly jolting it to ensure that the cooked food is heated evenly). In the existing technology, once the wok is lifted away from the cooking range, the wok is no longer effectively grounded. In this case, if the discharge electrode discharges towards the bottom of the wok, the wok will become charged and may easily cause electric shock to the human body. Therefore, for the current plasma stoves, when the plasma stove is completely separated from the wok, a simple and crude method of immediately turning off the fire is adopted to prevent electric shock. However, such a design causes the circuit control to immediately cut off the power supply and turn off the fire every time the wok is lifted away from the cooking range, and then turn on the fire again after the wok is placed back. Such repeated turning off and on of the fire results in discontinuous heat supply at the bottom of the wok, thus making it impossible to perform the normal wok-tossing cooking operation with the existing plasma stoves.

[0007] 2. The existing plasma stoves only simply ground the cooking range housing, but do not detect whether the entire circuit, especially the external power supply part, is effectively grounded. In some old residential areas / rural areas and other regions, when many residents' houses are connected to the power supply, the installation of the grounding wire is not strictly carried out in accordance with national standards. In this way, even if the existing plasma stove products have grounded the metal exposed parts of the products in the internal circuit part, if they are used in the above-mentioned old residential areas without grounding wires, they cannot achieve the effect of grounding protection and there are potential safety hazards.

[0008] 3. The existing plasma stoves only connect a leakage switch at the incoming line and do not perform leakage detection on the internal circuit of the cooking range, which also poses potential safety hazards.

[0009] Therefore, the existing technology needs to be improved. Summary of the Invention

[0010] In view of the deficiencies of the above-mentioned existing technology, the purpose of the present invention is to provide a safe plasma stove, aiming to enable the plasma stove to perform the wok-tossing operation safely and have multiple protections such as grounding detection and leakage detection.

[0011] To achieve the above purpose, the present invention adopts the following technical solutions:

[0012] A safe plasma stove includes a base, a cooking range disposed on the base, and an electronic control unit disposed in the base. A plurality of discharge electrodes exposed above the base are disposed in the cooking range. A voltage transformation circuit unit is also disposed in the base and is electrically connected to the electronic control unit and the discharge electrodes. A wire for connecting to an external power supply and connected to the electronic control unit extends out of the base, and the shells of the base and the cooking range are protected by grounding.

[0013] Among them, the electronic control unit is provided with a ground detection circuit and a total power leakage detection circuit. The ground detection circuit detects whether all the protective grounding points of the plasma stove are effectively grounded, and the total power leakage detection circuit is used to detect the difference between the currents flowing into and out of the positive and negative poles of the electronic control unit to determine whether the plasma stove is leaking electricity;

[0014] The wire is a three-wire wire for live, neutral and ground, and a three-pin plug is provided on the wire. The ground detection circuit is electrically connected to the protective grounding wire in the three-pin plug;

[0015] A liftable grounding device is further provided in the burner head. The liftable grounding device is provided with an elastically liftable protruding end protruding upward for elastic contact with the bottom of the cookware. The protruding end is electrically grounded and electrically connected to the ground detection circuit.

[0016] Among them, a leakage protection switch is further provided on the wire to connect the three-pin plug and the electronic control unit.

[0017] Among them, the liftable grounding device is further provided with a highest position switch circuit for detecting the highest position of the protruding end, which is electrically connected to the electronic control unit.

[0018] Among them, the electronic control unit further includes a main control circuit, a power supply circuit electrically connected to the main control circuit, and the output end of the power supply circuit is electrically connected to the input end of the voltage transformation circuit unit;

[0019] The ground detection circuit and the total power leakage detection circuit are electrically connected to the main control circuit.

[0020] Among them, the burner head further includes an installation housing for installing the voltage transformation circuit unit. The installation housing includes an upper shell and a lower shell. The upper shell is provided with a ground device installation cavity, and a ground connection wire is arranged in the ground device installation cavity;

[0021] The liftable grounding device includes a seat body, a sleeve arranged in the seat body, a spring installed in the sleeve and abutting against the sleeve and the base, and a lifting rod sleeved in the spring. The upper end of the lifting rod is a protruding end passing through the sleeve. The seat body is fixed in the ground device installation cavity of the upper shell and is connected to the ground connection wire.

[0022] Among them, a ceramic protection tube is further sleeved on the part of the upper end of the sleeve exposed from the upper shell;

[0023] A guiding nozzle is further provided at the top end of the sleeve, and the upper end of the lifting rod passes through the guiding nozzle.

[0024] Among them, a first wire groove communicating with the grounding device installation cavity is provided on the upper surface of the upper shell for laying a grounding connection wire that is grounded and connected to the liftable grounding device. First resistance grooves are also formed on both sides of the first wire groove and the periphery of the grounding device installation cavity. The first wire groove and the first resistance grooves are filled with insulating glue for resistance to electricity.

[0025] Among them, the burner head further includes a high-temperature resistant insulating board located above the installation shell, and the high-temperature resistant insulating board mounts the plurality of discharge electrodes.

[0026] Among them, a negative electrode for forming a discharge circuit with the plurality of discharge electrodes is further provided above the high-temperature resistant insulating board;

[0027] A negative electrode support installation cavity and a second wire groove communicating with the negative electrode support installation cavity are further provided on the upper surface of the upper shell for laying a negative electrode connection wire connected to the negative electrode. Second resistance grooves are also formed on both sides of the second wire groove and the periphery of the negative electrode support installation cavity. The second wire groove and the second resistance grooves are filled with insulating glue for resistance to electricity.

[0028] Among them, a temperature sensor is further provided on the installation shell and is electrically connected to the electronic control unit.

[0029] In the safe plasma cooker of the present invention, by arranging a liftable grounding device in the burner head, the extended end of the liftable grounding device is elastically contacted with the bottom of the cookware. In this way, during the wok-tossing operation, even if the cookware is separated from the burner head and the fire is not turned off, the cookware can still be effectively grounded through the contact with the extended end. Again, when the cookware is further separated from the extended end upward, there is already a sufficient distance between the bottom of the pot and the discharge electrode, so that the discharge electrode will no longer discharge to the bottom of the pot to ensure safety. It also detects whether the external mains power and the cooker shell are effectively grounded by setting a three-pin plug and a grounding detection circuit. If the grounding is invalid, the power supply of the circuit is turned off through the electronic control unit. At the same time, a total power leakage detection circuit is also provided to effectively detect whether there is leakage during the use of the cooker. If there is leakage, the power supply is turned off. In this way, the plasma cooker of the present invention has multiple protections such as grounding detection, leakage detection, and liftable grounding device to ensure the use safety of the product, and can perform the wok-tossing operation safely without repeatedly turning off and turning on the fire. Description of the Drawings

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on the structures shown in these drawings without creative efforts.

[0031] Figure 1Schematic diagram of the structure of the first embodiment of the safe plasma stove of the present invention;

[0032] Figure 2 is Figure 1 Exploded schematic diagram of the structure;

[0033] Figure 3 is Figure 1 Cross-sectional schematic diagram of the structure;

[0034] Figure 4 is Figure 1 Cross-sectional schematic diagram of the contact state between the liftable grounding device and the bottom surface of the cookware.

[0035] Figure 5 Schematic diagram of the circuit principle of the first embodiment of the safe plasma stove of the present invention;

[0036] Figure 6 Schematic diagram of the structure of the installation housing of the present invention;

[0037] Figure 7 Schematic diagram of the structure of the liftable grounding device of the present invention;

[0038] Figure 8 is Figure 7 Exploded schematic diagram of the structure;

[0039] Explanation of reference numerals:

[0040] 100 - Plasma stove, 1 - Burner head, 11 - Cookware support, 12 - Installation housing, 121 - Upper shell, 1210 - Grounding device installation cavity, 1211 - First wire groove, 1212 - First resistance slot, 1213 - Negative electrode support installation cavity, 1214 - Second wire groove, 1215 - Second resistance slot, 13 - High-temperature insulating board, 14 - Negative electrode, 122 - Lower shell, 13 - Switch button, 14 - Adjustment knob, 15 - Temperature sensor, 16 - Cooling fan, 17 - Air inlet, 18 - Air outlet, 191 - Incoming wire connection port, 192 - Ground wire connection port, 2 - Base, 21 - Human-machine interaction panel, 22 - Switch button, 23 - Adjustment knob, 3 - Electric control unit, 31 - Grounding detection circuit, 32 - Total power leakage detection circuit, 33 - Main control circuit, 34 - Power supply circuit, 4 - Discharge electrode, 5 - Transformer circuit unit, 6 - Wire, 7 - Three-pin plug, 7 - High-temperature insulating board, 8 - Liftable grounding device, 81 - Lift rod, 811 - Extended end, 82 - Seat body, 83 - Sleeve, 84 - Spring, 85 - Ceramic protection tube; 86 - Guide nozzle, 87 - First electrode plate, 88 - Second electrode plate, 9 - Leakage protection switch, 10 - Highest position switch circuit, 200 - Cookware. Detailed implementation manners

[0041] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0042] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0043] In the present invention, unless otherwise clearly defined and limited, the terms "connection", "fixation", etc. shall be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0044] In addition, the descriptions such as "first", "second", etc. in the present invention are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features.

[0045] Please refer to Figures 1 to 5, the present invention provides a safe plasma stove 100, which includes a base 2, a stove head 1 disposed on the base 2, and the stove head 1 can be one or more. And an electric control unit 3 disposed in the base 2, wherein a plurality of discharge electrodes 4 exposed above the base 2 are disposed in the stove head 1, and a voltage transformation circuit unit 5 is further disposed in the base 2 and electrically connected to the electric control unit 3 and the discharge electrodes 4. A wire 6 for connecting to an external power supply and connected to the electric control unit 3 extends out of the base 2, and the shells of the base 2 and the stove head 1 are protected and grounded. The stove head 1 further includes a cookware support 11 disposed on the base 1 for supporting the cookware 200. The cookware 200 can be made of materials such as metal cookware or ceramic cookware. The wire 6 is used to connect to an external mains power supply: 220V AC power supply. The protection grounding method for the shells of the base 2 and the stove head 1 can be to set a unified protection grounding point (protection grounding terminal) inside the plasma stove, and then the protection grounding terminal is connected to the shells of the metal components of the plasma stove such as the base 2, the stove head 1, etc. through circuit wires, and at the same time, the protection grounding terminal is connected to the ground wire in the wire 6 to connect to the protection grounding wire (PE) in the external mains power grid.

[0046] The electric control unit 3 is used to generate the driving power supply required by the voltage transformation circuit unit 5, and control the conduction, turn-off and output power of the voltage transformation circuit unit 5. The driving power supply generated by the electric control unit 3 is a low-voltage power supply with high frequency or low frequency. The voltage transformation circuit unit 5 converts the low-voltage electricity input by the electric control unit 3 into high-voltage electricity and then outputs it to the discharge electrodes 4 for discharging. The arc generated by the discharge of the discharge electrodes 4 ionizes the air to generate a high-temperature plasma to heat the bottom of the pot. In the embodiment of the present invention, the electric control unit 3 and the voltage transformation circuit unit 5 are isolated and disposed in the base 2.

[0047] The discharge electrode 4 of the plasma stove 100 of the present invention is a positive electrode. When the cookware 200 is a metal cookware, the metal cookware can be directly used as a negative electrode to form a discharge circuit; when the cookware is a ceramic cookware, a negative electrode needs to be separately disposed in the stove head 1.

[0048] As Figure 5 shown, the electric control unit 3 of the plasma stove 100 of the present invention is provided with a ground detection circuit 31 and a total power leakage detection circuit 32. The ground detection circuit 31 detects whether all the protection grounding points of the plasma stove 100 are effectively grounded, and the total power leakage detection circuit 32 is used to detect the difference between the current flowing in and out of the positive and negative poles of the electric control unit 3 to judge whether the plasma stove 100 leaks electricity.

[0049] The wire 6 is a three-wire wire for live, neutral and ground, and a three-pin plug 7 is disposed on the wire 6. The ground detection circuit 31 is electrically connected to the protection grounding wire in the three-pin plug 7. The three-wire wire for live, neutral and ground is a wire provided with a live wire, a neutral wire and a ground wire.

[0050] Due to the combination of the three - wire plug 7 and the ground detection circuit 31, when the user's household connects to the mains power supply, if the protective earthing wire (PE) of the mains power grid is not connected, after the three - wire plug 7 of the plasma cooker 100 of the present invention is inserted into the socket, the ground detection circuit 31 will send a detection signal to the protective earthing wire in the wire 6. When it is detected that effective grounding fails (such as through feedback voltage or feedback current detection), the power output from the electronic control unit 3 is turned off, and the plasma cooker 100 of the present invention cannot be used. In this way, in some old communities or rural areas without protective earthing wires, the plasma cooker 100 of the present invention can detect effective grounding and play a protective role.

[0051] At the same time, the ground detection circuit 31 of the present invention can also effectively detect the grounding of the metal components of the plasma cooker 100 itself, such as the base 2, the cooking head 1, etc., and the cookware 200 placed on the cooking head 1. If there is no effective grounding, the power output from the electronic control unit 3 is also turned off to prohibit the use of the plasma cooker 100. This can prevent electric shock caused by grounding failure.

[0052] The total power leakage detection circuit 32 of the plasma cooker 100 of the present invention will detect the magnitude of the current flowing out from the "positive pole" of the electronic control unit 3, including the total current flowing out to the transformer circuit unit 5 and then to all discharge electrodes. At the same time, it also detects the magnitude of the current flowing into the "negative pole", such as the total current of the negative - pole loop current conducting to the discharge electrodes, the current of each grounding device, etc., and makes a judgment. If the total current flowing into the negative pole and each grounding device is less than the current flowing out from the positive pole, it indicates that there is a leakage, and the electronic control unit 3 will immediately cut off the power and turn off the fire, thus preventing electric shock accidents caused by leakage.

[0053] As Figure 3 and Figure 4 shown, a lift - up grounding device 8 is further provided inside the cooking head 1 of the plasma cooker 100 of the present invention. The lift - up grounding device 8 is provided with an elastically lift - up extending end 811 protruding upward for elastically contacting the bottom of the cookware. The extending end 811 is electrically grounded and electrically connected to the ground detection circuit 31. The electrical grounding of the extending end 811 can be connected to the ground through the ground connection point on the upper circuit board of the electronic control unit 3, or directly connected to the protective earthing wire PE through the internal protective earthing terminal of the plasma cooker to connect to the ground, so that the potential is zero.

[0054] The extending end 811 of the liftable grounding device 8 can be lifted and elastically contacts the bottom of the cookware 200. In this way, within the extending range of the extending end 811, even if the cookware 200 is lifted off the cookware support 11, since the bottom of the pot is still in contact with the extending end 811, and the extending end 811 is protected and grounded, the cookware 200 is still grounded and there is no safety hazard. If the extending end 811 is not effectively grounded, the grounding detection circuit 31 will function to cut off the power supply. Again, even if the cookware 200 is lifted to a height higher than the highest extending height of the extending end 101 and separated from it, at this time, since the bottom of the cookware 200 is far enough from the discharge electrode 5, the discharge electrode 5 will not discharge towards the bottom of the pot, and the cookware 200 is also safe at this time. In this way, the user can perform "tossing the pot" during cooking without safety hazards. The highest extending height of the extending end 811 can be designed through experiments. For example, the height of the highest extending height of the extending end 811 from the plane of the discharge electrode 5 is greater than or equal to 50 mm, or the distance between the highest extending height of the extending end 811 and the plane of the discharge electrode 5 is greater than or equal to 3 times the distance from the discharge electrode 5 to the bottom of the pot or to the negative electrode.

[0055] Meanwhile, due to the safety function of the liftable grounding device 8, after the cookware 200 leaves the cookware support 11, the plasma cooker 100 of the present invention does not need to turn off the fire immediately, avoiding the defect in the prior art that if "tossing the pot" is required, the cooking appliance needs to turn off and turn on the fire repeatedly to ensure safety, resulting in discontinuous heat and affecting cooking.

[0056] That is, the setting of the liftable grounding device 8 of the present invention enables the plasma cooker 100 of the present invention to perform the safe and normal "tossing the pot" operation without repeatedly turning on and off the fire.

[0057] In this way, the plasma cooker 100 of the present invention has multiple protections such as grounding detection, leakage detection, and liftable grounding device to ensure the use safety of the product.

[0058] As Figure 5 shown, the electronic control unit 3 of the embodiment of the present invention further includes a main control circuit 33, a power supply circuit 34 electrically connected to the main control circuit 33, and the output end of the power supply circuit 34 is electrically connected to the input end of the voltage transformation circuit unit 5; the grounding detection circuit 31 and the total power leakage detection circuit 32 are electrically connected to the main control circuit 33.

[0059] The main control circuit 33 can be controlled by a single-chip microcomputer combined with a program. The main control circuit 33 controls the output of the voltage transformation circuit unit 5, and the power supply circuit 34 provides driving current for the voltage transformation circuit unit 5. The power supply circuit 34 is connected to the external mains through a wire 5 and a three-pin plug 6.

[0060] In the embodiment of the present invention, a human-machine interaction panel 21 is further provided on the base 2 for controlling the plasma cooker 100. The human-machine interaction panel 21 can be set as a button or a touch screen. A switch button 22 and an adjustment knob 23 are also provided on the base 2 for turning on and off the plasma cooker 100 and adjusting the output power. The human-machine interaction panel 21, the switch button 22 and the adjustment knob 23 are all electrically connected to the main control circuit 33.

[0061] Further, as Figure 1 shown, a leakage protection switch 9 is further provided on the wire 6 of the embodiment of the present invention, connecting the three-pin plug 7 and the electric control unit 3. The setting of the leakage protection switch 9 can cooperate with the total power leakage detection circuit 32 to play a dual leakage protection role. At the same time, the leakage protection switch 9 also has short-circuit and overload protection to ensure the safe use of the plasma cooker 100 of the present invention.

[0062] Further, as Figure 5 shown, the liftable grounding device 8 of the present invention is further provided with a highest position switch circuit 10 for detecting the highest position of the extended end 811, which is electrically connected to the electric control unit 3. The highest position switch circuit 10 is used to detect whether the extended end 811 is at the highest position. If the extended end 811 is at the highest position, it means that the cookware 200 has been separated from the cooking head 1. The highest position switch circuit 10 sends this detection information to the electric control unit 3, and the electric control unit 3 can time the time when the cookware 200 is separated from the cooking head 1. When the leaving time reaches a preset time, such as 20 s, the power supply is turned off to turn off the fire, preventing accidents caused by the user forgetting to turn off the fire.

[0063] Specifically, as Figures 6 to 8 shown, the cooking head 1 of the plasma cooker 100 of the present invention further includes an installation housing 12 for installing the voltage transformation circuit unit 5. The installation housing 12 includes an upper housing 121 and a lower housing 122. The upper housing 121 is provided with a grounding device installation cavity 1210, and a grounding connection wire (not shown) is provided in the grounding device installation cavity 1210. The grounding device installation cavity 1210 is used for installing the liftable grounding device 8. The installation housing 12 protects the voltage transformation circuit unit 5 and can support the liftable grounding device 8, the cookware support 11, the discharge electrode 4, etc. on the cooking head 1. Preferably, a temperature sensor 15 electrically connected to the electric control unit 3 is further provided on the installation housing 12. The temperature sensor 15 can detect the temperature of the heat conducted from the voltage transformation circuit unit 5 or the plasma beam to the installation housing 12. When the actual temperature of the installation housing 12 exceeds the preset temperature during the working process, the power supply of the voltage transformation circuit unit 5 will be cut off, so that the voltage transformation circuit unit 5 stops outputting electric energy to the discharge electrode and stops discharging, to ensure the use safety.

[0064] Preferably, as Figure 2As shown in the figure, a heat dissipation fan 16 facing the side wall of the installation housing 12, and an air inlet 17 and an air outlet 18 for the heat dissipation fan 16 to intake and exhaust air are further provided on the base 2 of the embodiment of the present invention. In this way, the heat generated by the voltage conversion circuit unit 5 can be quickly blown out of the base 2, ensuring the heat dissipation effect of the whole machine.

[0065] As Figure 6 shown in the figure, the installation housing 12 is further provided with an incoming line connection port 191 and a ground wire connection port 192. The incoming line connection port 191 is used to connect the voltage conversion circuit unit 5 and the power supply circuit 34. The ground wire connection port 192 is used for protective grounding of the metal shell. Preferably, the upper shell 121 of the embodiment of the present invention adopts a plastic insulating material for the insulation between the discharge electrodes 4 and the insulation of the connection wires between the discharge electrodes 4 and the voltage conversion circuit unit 5.

[0066] The liftable grounding device 8 of the present invention includes a seat body 82, a sleeve 83 disposed in the seat body 82, a spring 84 installed in the sleeve 83 and abutting the sleeve 83 and the base 82, and a lifting rod 81 sleeved in the spring 84. The upper end of the lifting rod 81 is an extending end 811 that penetrates out of the sleeve 83. The seat body 82 is fixed in the grounding device installation cavity 1210 of the upper shell 121 and is connected to the grounding connection wire. Due to the action of the spring 84, the lifting rod 81 realizes up and down lifting and slides up and down in the sleeve 83. At the same time, since the lifting rod 81 is sleeved in the spring 84 and the spring 84 abuts on the base 82, and the base 82 is connected to the grounding connection wire to realize grounding, in this way, the spring 84, the lifting rod 81, and the sleeve 83 are all electrically grounded. When the cookware 200 is placed on the cookware support 11 and contacts the extending end 811 of the lifting rod 81, the cookware is grounded. And because the lifting rod 81 elastically lifts within the lowest and highest positions set in the sleeve 83, when the cookware 200 lifts within the lowest and highest positions, it is elastically in contact with the extending end 811 of the lifting rod 81. Thus, the cookware 200 can be effectively grounded during the stir-frying operation within the lowest and highest positions, ensuring the safety of the stir-frying operator.

[0067] Preferably, as Figure 8 shown in the figure, a ceramic protection tube 85 is further sleeved on the part of the upper end of the sleeve 83 of the embodiment of the present invention that exposes the upper shell 121. The ceramic protection tube 85 is sleeved outside the sleeve 83 to prevent the discharge electrodes 4 on the upper shell 121 from discharging to the metal and wires in the liftable grounding device 8, resulting in abnormal discharge of the product.

[0068] At the top end of the sleeve 83 in the embodiment of the present invention, a guiding nozzle 86 is further provided, and the upper end of the lifting rod 81 is inserted through the guiding nozzle 86. The extending end 811 of the lifting rod 81 is inserted through and exposed from the guiding nozzle 86. The guiding nozzle 86 is used to guide the lifting rod 81 to prevent the lifting rod 81 from swaying left and right during the lifting process and affecting the contact with the bottom of the pot. Preferably, the guiding nozzle 86 is made of insulating materials such as ceramics and plastics.

[0069] Specifically, the highest position switch circuit 10 in the embodiment of the present invention includes a first electrode plate 87 fixed to the inner top end of the sleeve 83 and a second electrode plate 88 fixed to the bottom of the lifting rod 81. As the lifting rod 81 moves upward, when the extending end 811 extends upward to reach the highest position, the second electrode plate 88 contacts the first electrode plate 87. At this time, the highest position switch circuit 10 is turned on and sends a signal to the main control circuit 33. The main control circuit 33 starts timing to calculate the time when the cookware 200 separates from the extending end 811 to determine whether to turn off the fire.

[0070] Please continue to refer to Figure 6 Furthermore, on the upper surface of the upper shell 121 of the plasma cooker 100 of the present invention, a first wire groove 1211 communicating with the grounding device installation cavity 1210 is provided for laying a grounding connection wire connected to the liftable grounding device 8. First resistance grooves 1212 are respectively formed on both sides of the first wire groove 1211 and the periphery of the grounding device installation cavity 1210. The first wire groove 1211 and the first resistance grooves 1212 are filled with insulating glue for resistance to electricity. The first wire groove 1211 is used to lead out the grounding wire of the liftable grounding device. Since when the transformer circuit unit 5 is connected to a plurality of discharge electrodes 4, a plurality of wires need to be arranged above the upper shell 121 and connected to the bottom of the discharge electrodes 4, and these wires and the discharge electrodes 4 carry positive electricity, and the grounding connection wire arranged in the first wire groove 1211 is of negative polarity, it is easy to cause the discharge electrodes 4 to discharge to the grounding wire in the first wire groove 1211. Therefore, a layer of first resistance grooves 1212 is further provided on both sides of the first wire groove 1211 and the periphery of the grounding device installation cavity 1210, and insulating glue is provided in the first wire groove 1211 and the first resistance grooves 1212 to prevent abnormal discharge and avoid affecting the normal use of the product due to abnormal discharge.

[0071] Please continue to refer to Figure 3 Preferably, the burner head 1 of the plasma cooker 100 of the present invention further includes a high-temperature resistant insulating plate 13 located above the installation housing 12, and the high-temperature resistant insulating plate 13 mounts the plurality of discharge electrodes 4.

[0072] In the embodiment of the present invention, the upper shell 121 of the installation shell 12 supports the high-temperature resistant insulating plate 13 and the cookware support 11. On the one hand, the high-temperature resistant insulating plate 13 can prevent the heat loss from the bottom of the cookware, and on the other hand, it can block the heat from flowing downward to the installation shell 12 to prevent the temperature of the installation shell 12 from being too high and affecting the voltage transformation circuit unit 5 therein. At the same time, the high-temperature resistant insulating plate 13 is also used to install and support a plurality of discharge electrodes 4.

[0073] Preferably, a negative electrode 14 for forming a discharge loop with a plurality of discharge electrodes 4 is further provided above the high-temperature resistant insulating plate 13 of the present invention.

[0074] In the embodiment of the present invention, the negative electrode 14 is separately provided. In this way, during use, the cookware 200 is no longer part of the electrical circuit, changing the method of some existing plasma cooktops 100 where the plasma beam is generated between the "discharge electrode" and the "cookware", and allowing the plasma beam to be generated between the "discharge electrode" and the "negative electrode", so that both metal and non-metal cookware can be used on the plasma cooktop 100 of the present invention. At the same time, it avoids the problem that when using the cookware as the negative electrode, the plasma directly hits the bottom of the cookware, causing the cookware to be punctured under long-term action and affecting the service life of the cookware.

[0075] Further, in combination Figure 6 , on the upper surface of the upper shell 121 of the embodiment of the present invention, a negative electrode support installation cavity 1213 and a second wire groove 1214 communicating with the negative electrode support installation cavity 1213 are further provided for laying a negative electrode connecting wire (not shown) connected to the negative electrode 14. Second resistance grooves 1215 are also provided on both sides of the second wire groove 1214 and the periphery of the negative electrode support installation cavity 1213, and the second wire groove 1214 and the second resistance grooves 1215 are filled with insulating glue for resistance to electricity. The negative electrode support installation cavity 1213 is used to place a mounting seat, and the mounting seat is used to support the negative electrode 14. The negative electrode connecting wire is connected to the power ground of the electronic control unit 3.

[0076] The second wire groove 1214 is used to lead out the negative electrode connecting wire of the negative electrode 14. Similarly, since there are multiple wires and discharge electrodes 4 above the upper shell 121, and these wires and discharge electrodes 4 carry positive polarity electricity, and the negative electrode connecting wire provided in the second wire groove 1214 is of negative polarity, it is easy to cause the discharge electrode 4 to discharge to the negative electrode connecting wire in the second wire groove 1214. Therefore, a second layer of resistance grooves 1215 is further provided on both sides of the second wire groove 1214 and the periphery of the negative electrode support installation cavity 1213, and insulating glue is provided in the second wire groove 1214 and the second resistance grooves 1215 to prevent discharge and avoid affecting the normal use of the product due to abnormal discharge at this place.

[0077] The safety-type plasma stove 100 proposed in the embodiment of the present invention is provided with a liftable grounding device 8 inside the stove head 1, so that the protruding end 811 of the liftable grounding device 8 is in elastic contact with the bottom of the cookware 200. In this way, during the wok-tossing operation, even if the cookware 200 is separated from the stove head and the fire is not turned off, the cookware 200 can still be effectively grounded through contact with the protruding end. Moreover, when the cookware 200 is further lifted away from the protruding end, there is a sufficient distance between the bottom of the pot and the discharge electrode, so that the discharge electrode will no longer discharge to the bottom of the pot to ensure safety. The present invention also detects whether the external mains power and the stove shell are effectively grounded by setting a three-wire plug 6 and a grounding detection circuit 31. At the same time, a total power leakage detection circuit 32 is also provided to effectively detect whether there is power leakage during the use of the stove. In this way, the plasma stove 100 of the present invention has multiple protections such as grounding detection, leakage detection, and liftable grounding device to ensure the safe use of the product, and it can perform the wok-tossing operation safely.

[0078] The above are only examples clearly illustrating the present invention, and do not limit the patent scope of the present invention. It is impossible to enumerate all implementation manners here. Any equivalent structural transformation made by using the content of the technical solution of the present invention under the concept of the present invention, or direct / indirect application in other related technical fields is included in the patent protection scope of the present invention.

Claims

1. A safety type plasma stove, comprising a base, a stove head arranged on the base, and an electric control unit arranged in the base. A plurality of discharge electrodes exposed above the base are arranged in the stove head. A voltage transformation circuit unit is also arranged in the base and is electrically connected to the electric control unit and the discharge electrodes. A wire for connecting to an external power supply and connected to the electric control unit extends out of the base. The shells of the base and the stove head are protected and grounded; Characterized in that, The electric control unit is provided with a grounding detection circuit and a total power leakage detection circuit. The grounding detection circuit detects whether all the protected grounding points of the plasma stove are effectively grounded. The total power leakage detection circuit is used to detect the difference between the current flowing into and out of the positive and negative poles of the electric control unit to judge whether the plasma stove leaks electricity; The wire is a three-wire wire of live wire, neutral wire and ground wire. A three-pin plug is arranged on the wire. The grounding detection circuit is electrically connected to the protective grounding wire in the three-pin plug; A liftable grounding device is also arranged in the stove head. The liftable grounding device is provided with an elastically liftable extending end protruding upward for elastically contacting the bottom of the cookware. The extending end is electrically grounded and is electrically connected to the grounding detection circuit; The liftable grounding device is also provided with a highest position switch circuit for detecting the highest position of the extending end. The highest position switch circuit is electrically connected to the electric control unit.

2. The safety type plasma stove according to claim 1, Characterized in that, A leakage protection switch is also arranged on the wire and is connected to the three-pin plug and the electric control unit.

3. The safety type plasma stove according to claim 1, Characterized in that, The electric control unit further includes a main control circuit, a power supply circuit electrically connected to the main control circuit. The output end of the power supply circuit is electrically connected to the input end of the voltage transformation circuit unit; The grounding detection circuit and the total power leakage detection circuit are electrically connected to the main control circuit.

4. The safety type plasma stove according to claim 1, Characterized in that, The stove head further includes an installation housing for installing the voltage transformation circuit unit. The installation housing includes an upper shell and a lower shell. The upper shell is provided with a grounding device installation cavity, and a grounding connection wire is arranged in the grounding device installation cavity; The liftable grounding device includes a seat body, a sleeve arranged in the seat body, a spring installed in the sleeve and abutting against the sleeve and the base, and a lifting rod sleeved in the spring. The upper end of the lifting rod is an extending end and passes through the sleeve. The seat body is fixed in the grounding device installation cavity of the upper shell and is connected to the grounding connection wire.

5. The safety type plasma stove according to claim 4, Characterized in that, A ceramic protection tube is also sleeved on the part of the upper end of the sleeve exposed above the upper shell; A guiding nozzle is also arranged at the top end of the sleeve. The upper end of the lifting rod passes through the guiding nozzle.

6. The safety type plasma stove according to claim 4, Characterized in that, The upper surface of the upper shell is provided with a first wire groove communicating with the grounding device installation cavity for laying the grounding connection wire grounded to the liftable grounding device. First resistance grooves are also opened on both sides of the first wire groove and the periphery of the grounding device installation cavity. The first wire groove and the first resistance grooves are filled with insulating glue for resistance.

7. The safe plasma cooker according to claim 4, characterized in that, the burner head further includes a high-temperature resistant insulating plate located above the installation housing, and the high-temperature resistant insulating plate mounts the plurality of discharge electrodes.

8. The safe plasma cooker according to claim 7, characterized in that, a negative electrode for forming a discharge circuit with the plurality of discharge electrodes is further provided above the high-temperature resistant insulating plate; a negative electrode support mounting cavity and a second wire groove communicating with the negative electrode support mounting cavity are further provided on the upper surface of the upper shell for laying a negative electrode connection wire connected to the negative electrode. Second resistance grooves are further formed on both sides of the second wire groove and the periphery of the negative electrode support mounting cavity, and the second wire groove and the second resistance groove are filled with insulating glue for resistance.

9. The safe plasma cooker according to claim 4, characterized in that, a temperature sensor is further provided on the installation housing and is electrically connected to the electronic control unit.

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