阅读说明：本技术 一种应用于保温电热水壶上的温控器 (Temperature controller applied to heat-preservation electric kettle ) 是由 甘跃斌 于 2021-02-01 设计创作，主要内容包括：一种应用于保温电热水壶上的温控器,包括温控器主体、安装在温控器主体上的烧水感温部件、保温感温部件和干烧感温部件,所述烧水感温部件中连接有用于控制烧水感温部件开关的烧水开关,所述保温感温部件连接有用于调节保温温度的温度调节器,通过在干烧感温部件中设置防二次干烧机构和复位机构,使得处于保温状态下的电热水壶在温度超过设定值,即发生干烧时,干烧感温部件内部电路断开,同时干烧动触片与防二次干烧机构也分离,干烧感温部件内部电路保持断开,只有通过复位机构将干烧动触片和二次干烧机构复位后才能再次实现加热功能,本发明能有效防止电热水壶在保温状态下反复干烧,安全性大大提高。(A temperature controller applied to a heat-preservation electric kettle comprises a temperature controller main body, a water boiling temperature sensing part, a heat-preservation temperature sensing part and a dry-burning temperature sensing part, wherein the water boiling temperature sensing part is installed on the temperature controller main body, a water boiling switch for controlling the water boiling temperature sensing part is connected in the water boiling temperature sensing part, the heat-preservation temperature sensing part is connected with a temperature regulator for regulating the heat-preservation temperature, a secondary dry-burning prevention mechanism and a reset mechanism are arranged in the dry-burning temperature sensing part, so that when the temperature of the electric kettle in a heat-preservation state exceeds a set value, namely, when dry burning occurs, an internal circuit of the dry-burning temperature sensing part is disconnected, a dry-burning movable contact is separated from the secondary dry-burning prevention mechanism, an internal circuit of the dry-burning temperature sensing part is disconnected, and the heating function can be realized again only after the dry-burning movable contact and the secondary dry-burning mechanism, the safety is greatly improved.)

1. A temperature controller applied to a heat-preservation electric kettle comprises a temperature controller main body (1), a water boiling temperature sensing component (2), a heat-preservation temperature sensing component (3) and a dry-burning temperature sensing component (4), wherein the water boiling temperature sensing component (2), the heat-preservation temperature sensing component (3) and the dry-burning temperature sensing component (4) are installed on the temperature controller main body (1), a water boiling switch (5) used for controlling the switch of the water boiling temperature sensing component (2) is connected in the water boiling temperature sensing component (2), a temperature regulator (6) used for regulating the heat-preservation temperature is connected in the heat-preservation temperature sensing component (3), the circuit input end of the dry-burning temperature sensing component (4) is connected with a fire wire, the circuit output end of the dry-burning temperature sensing component (4) is connected with the water boiling temperature sensing component (2) and the heat-preservation temperature sensing component (3), the water boiling temperature sensing component (2) and the heat-preservation temperature sensing component (3, the circuit output end and the zero line of heater (7) are connected, dry combustion method temperature-sensing part (4) including be used for sensing electric kettle heating temperature dry combustion method temperature-sensing piece (41), be used for mutually supporting dry combustion method movable contact piece (42) and dry combustion method static contact piece (43) of controlling dry combustion method temperature-sensing part (4) internal circuit break-make, its characterized in that: a linkage rod (44) is arranged between the dry-burning temperature sensing piece (41) and the dry-burning movable contact piece (42) for linkage action, and a secondary dry-burning prevention mechanism (8) for preventing the electric kettle from secondary dry burning and a reset mechanism (9) for driving the secondary dry-burning prevention mechanism (8) to reset after action are arranged in the dry-burning temperature sensing part (4).

2. The temperature controller applied to the heat-preservation electric kettle according to claim 1 is characterized in that: in a normal use state: the dry-burning movable contact piece (42) is contacted with the dry-burning static contact piece (43), the internal circuit of the dry-burning temperature sensing part (4) is communicated, and the dry-burning movable contact piece (42) pushes the secondary dry-burning prevention mechanism (8) in a static state;

dry burning occurs: the dry-burning temperature sensing piece (41) is deformed by temperature change, the dry-burning temperature sensing piece (41) drives the dry-burning movable contact piece (42) to act through the linkage rod (44), so that the dry-burning movable contact piece (42) is separated from the dry-burning static contact piece (43), the internal circuit of the dry-burning temperature sensing part (4) is disconnected, meanwhile, the dry-burning movable contact piece (42) is separated from the secondary dry-burning prevention mechanism (8), the dry-burning movable contact piece (42) is locked in a state of being separated from the dry-burning static contact piece (43) by the action of the secondary dry-burning prevention mechanism (8), and the internal circuit of the dry-burning temperature sensing part (4) is kept disconnected;

and (3) recovering the circuit after dry burning: the dry-burning movable contact piece (42) is separated from the secondary dry-burning prevention mechanism (8) through the action of the reset mechanism (9), the reset mechanism (9) is restored to the state before the action, the dry-burning movable contact piece (42) is firstly restored to the state of being contacted with the dry-burning static contact piece (43), and then the secondary dry-burning prevention mechanism (8) is restored to the state of being pushed by the dry-burning movable contact piece (42) to be in a static state.

3. The temperature controller applied to the heat-preservation electric kettle according to claim 2 is characterized in that: the secondary dry burning prevention mechanism (8) comprises a rotating head (81) and a rotating shaft (82), the rotating head (81) is installed on the rotating shaft (82), a pushing part (811) used for being in pushing contact with a dry burning movable contact piece (42) in a normal use state, a locking part (812) used for locking the dry burning movable contact piece (42) in a state of being separated from a dry burning static contact piece (43) when dry burning occurs, and a resetting part (813) used for being linked with a resetting mechanism (9) when a circuit is recovered after dry burning.

4. The temperature controller applied to the heat-preservation electric kettle according to claim 3 is characterized in that: the rotating shaft (82) is arranged at the eccentric position of the rotating head (81), and in a normal use state: the rotating head (81) has a torque rotating towards the direction of the dry burning contact piece (42) relative to the rotating shaft (82), and the dry burning contact piece (42) pushes against the pushing part (811) of the rotating head (81) to balance the torque of the rotating head (81).

5. The temperature controller applied to the heat-preservation electric kettle according to claim 4 is characterized in that: after dry burning, the gravity center of the rotating head (81) and the axis of the rotating shaft (82) are on the same vertical plane.

6. The temperature controller applied to the heat-preservation electric kettle according to claim 3 is characterized in that: the reset mechanism (9) comprises a movable column (91) capable of moving up and down and a reset head (92) fixedly arranged on one side of the movable column (91), the reset head (92) comprises a first step (921) used for being linked with a reset part (813) and a second step (922) used for being linked with a dry burning movable contact piece (42), the first step (921) extends to the upper part of the reset part (813), the second step (922) extends to the upper part of the dry burning movable contact piece (42), and the first step (921) is lower than the second step (922).

7. The temperature controller applied to the heat-preservation electric kettle according to claim 6 is characterized in that: the bottom of the temperature controller main body (1) is provided with a bottom cover (10), the bottom cover (10) is provided with a through hole (101) for the movable column (91) to penetrate out, a base surface cover (11) is arranged below the bottom cover (10), the base surface cover (11) is provided with a plurality of pits (111) corresponding to the through holes (101), a cylindrical hole is arranged inside the movable column (91), a spring (12) is arranged in the cylindrical hole, the spring (12) is used for providing a downward moving pushing elastic force for the moving column (91), the outer side of the moving column (91) is also sleeved with a sleeve member (93) for moving and guiding the moving column (91), the sleeve member (93) is provided with an open slot (931) for the extension of the reset head (92), the bottom of the open groove (931) is provided with a limit step (932) for limiting the downward movement stroke of the moving column (91).

8. The temperature controller applied to the heat-preservation electric kettle of claim 7 is characterized in that: the fixed one side that sets up in external member (93) of one end of pivot (82), the other end outwards extends the setting, still be equipped with on rotation head (81) and be used for canceling release mechanical system (9) and prevent that secondary dry combustion method constructs when (8) act and avoid empty part (814) of interfering.

9. The temperature controller applied to the heat-preservation electric kettle according to claim 1 is characterized in that: the water boiling temperature sensing part (2) is a steam switch.

10. The temperature controller applied to the heat-preservation electric kettle according to claim 1 is characterized in that: the heat-preservation temperature-sensing component (3) is a KST adjustable temperature controller.

Technical Field

The invention relates to a temperature controller on an electric kettle, in particular to a temperature controller applied to a heat-preservation electric kettle.

Background

At present, the existing electric heating kettle is divided into a heating insulation function and a heating insulation function, the electric heating kettle with the heating insulation function comprises a split type heating insulation structure with a switch and a heating insulation structure without the switch, the heating insulation structure without the switch is used for heating insulation after boiling water, and as a live wire and a zero line elastic sheet on a base are always connected with a power line, the heating insulation structure is always electrified to work, and potential safety hazards exist; and split type insulation construction, can realize preventing insulation construction long-term work limitedly, split type insulation construction mainly is add independent switch in addition on the base, through opening or closing of solitary control by temperature change structure, its operation is convenient inadequately, the structure is complicated, and the processing cost is high, and must not forget to close under the condition of this switch at the user, just play and prevent that the temperature controller from constantly working until getting into the state of boiling dry water, if the user forgets to close or leave for a long time, probably can cause insulation construction to boil dry water and continue to keep warm and heat until the dangerous situation appears equally.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides the temperature controller which is applied to the heat-preservation electric kettle, has simple and reasonable structure and can effectively prevent the electric kettle from being repeatedly burnt.

The technical scheme adopted by the invention for solving the technical problems is as follows:

the temperature controller comprises a temperature controller main body, a water boiling temperature sensing component, a heat preservation temperature sensing component and a dry-burning temperature sensing component, wherein the water boiling temperature sensing component, the heat preservation temperature sensing component and the dry-burning temperature sensing component are mounted on the temperature controller main body, a water boiling switch used for controlling the water boiling temperature sensing component is connected in the water boiling temperature sensing component, the heat preservation temperature sensing component is connected with a temperature regulator used for regulating heat preservation temperature, the circuit input end of the dry-burning temperature sensing component is connected with a live wire, the circuit output end of the dry-burning temperature sensing component is connected with the water boiling temperature sensing component and the heat preservation temperature sensing component, the water boiling temperature sensing component and the heat preservation temperature sensing component are arranged in parallel, the circuit output end of the water boiling temperature sensing component and the circuit output end of the heat preservation temperature sensing component are both connected with a heater of the electric kettle, the, The electric kettle dry-burning temperature sensing component comprises a dry-burning movable contact piece and a dry-burning static contact piece which are used for controlling the on-off of an internal circuit of the dry-burning temperature sensing component in a matched mode, a linkage rod is arranged between the dry-burning temperature sensing piece and the dry-burning movable contact piece to perform linkage action, and a secondary dry-burning prevention mechanism used for preventing an electric kettle from being secondarily dried-burned and a reset mechanism used for driving the secondary dry-burning prevention mechanism to reset after action are arranged in the dry-burning temperature sensing component.

In the present invention, in a normal use state: the dry-burning movable contact piece is contacted with the dry-burning static contact piece, the internal circuit of the dry-burning temperature sensing part is connected, and the dry-burning movable contact piece pushes the secondary dry-burning prevention mechanism in a static state; dry burning occurs: the dry-burning temperature sensing piece is deformed by temperature change, the dry-burning temperature sensing piece drives the dry-burning movable contact piece to act through the linkage rod, so that the dry-burning movable contact piece is separated from the dry-burning static contact piece, an internal circuit of the dry-burning temperature sensing part is disconnected, meanwhile, the dry-burning movable contact piece is also separated from the secondary dry-burning prevention mechanism, the dry-burning movable contact piece is locked in a state of being separated from the dry-burning static contact piece by the action of the secondary dry-burning prevention mechanism, and the internal circuit of the dry-burning temperature sensing part is kept disconnected; and (3) recovering the circuit after dry burning: the dry-burning movable contact piece is separated from the secondary dry-burning prevention mechanism through the action of the reset mechanism, the reset mechanism is restored to the state before the action, the dry-burning movable contact piece is firstly restored to the state of being contacted with the dry-burning static contact piece, and then the secondary dry-burning prevention mechanism is restored to the state of being pushed by the dry-burning movable contact piece to be in a static state.

In the invention, the secondary dry burning prevention mechanism comprises a rotating head and a rotating shaft, wherein the rotating head is arranged on the rotating shaft, and the rotating head is internally provided with a pushing part used for being in pushing contact with the dry burning movable contact piece in a normal use state, a locking part used for locking the dry burning movable contact piece in a state of being separated from the dry burning static contact piece when dry burning occurs, and a resetting part used for being linked with the resetting mechanism when a circuit is recovered after the dry burning.

In the invention, the rotating shaft is arranged at the eccentric position of the rotating head, and in a normal use state: the rotating head is provided with a torque rotating towards the direction of the dry-burning movable contact piece relative to the rotating shaft, and the dry-burning movable contact piece is abutted against the abutting part of the rotating head to balance the torque of the rotating head.

In the invention, after dry burning, the gravity center of the rotating head and the axis of the rotating shaft are on the same vertical plane.

In the invention, the reset mechanism comprises a movable column capable of moving up and down and a reset head fixedly arranged on one side of the movable column, the reset head comprises a first step for linking with the reset part and a second step for linking with the dry-burning movable contact piece, the first step extends to the upper part of the reset part, the second step extends to the upper part of the dry-burning movable contact piece, and the first step is lower than the second step.

In the invention, a bottom cover is arranged at the bottom of the temperature controller main body (1), a through hole for the movable column to penetrate through is formed in the bottom cover, a base surface cover is arranged below the bottom cover, a plurality of pits corresponding to the through hole are formed in the base surface cover, a cylindrical hole is formed in the movable column, a spring is arranged in the cylindrical hole and used for providing downward pushing elastic force for the movable column (91), a sleeve piece used for moving and guiding the movable column is further sleeved on the outer side of the movable column, an open slot used for extending out of a reset head is formed in the sleeve piece, and a limiting step used for limiting the downward moving stroke of the movable column is formed in the bottom of the open slot.

In the invention, one end of the rotating shaft is fixedly arranged at one side of the sleeve, the other end of the rotating shaft extends outwards, and the rotating head is also provided with a clearance part for avoiding interference when the reset mechanism and the secondary dry burning prevention mechanism act.

In the invention, the water boiling temperature sensing part is a steam switch.

In the invention, the heat-preservation temperature-sensing component is a KST adjustable temperature controller.

The invention has the beneficial effects that: the invention sets a secondary dry-burning prevention mechanism and a reset mechanism in the dry-burning temperature sensing part, so that when the temperature of the electric kettle in a heat preservation state exceeds a set value, namely when dry burning occurs, the dry-burning temperature sensing piece deforms due to temperature change, the dry-burning temperature sensing piece drives the dry-burning movable contact piece to act through the linkage rod, the dry-burning movable contact piece is separated from the dry-burning static contact piece, the internal circuit of the dry-burning temperature sensing part is disconnected, meanwhile, the dry-burning movable contact piece is separated from the secondary dry-burning prevention mechanism, the dry-burning movable contact piece is locked in a state separated from the dry-burning static contact piece by the action of the secondary dry-burning prevention mechanism, the internal circuit of the dry-burning temperature sensing part is disconnected, and the heating function can be realized again only after the dry-burning movable contact piece and the secondary dry-burning mechanism are reset through the reset mechanism.

Drawings

The invention is further illustrated by the following figures and embodiments:

FIG. 1 is a schematic view of the overall installation structure of the present embodiment;

FIG. 2 is a schematic diagram showing the connection of circuit components according to the present embodiment;

FIG. 3 is a schematic view of the dry-burning temperature sensing component of the present embodiment in a normal use state;

FIG. 4 is a diagram illustrating the operation of the second dry-heating prevention mechanism of the dry-heating temperature sensing device of this embodiment;

FIG. 5 is a diagram showing the temperature-sensitive part after the pressing operation of the reset mechanism;

FIG. 6 is a schematic structural diagram of the secondary dry-heating prevention mechanism of the present embodiment;

FIG. 7 is a schematic view of the mounting structure of the reset mechanism of the present embodiment;

FIG. 8 is a schematic view of an integrated structure of the movable column and the reset head in this embodiment;

FIG. 9 is a schematic structural diagram of the kit according to the present embodiment;

FIG. 10 is a force analysis diagram of the whole operation process of the secondary dry-fire prevention mechanism of the present embodiment;

fig. 11 is a schematic connection diagram of the thermostat main body, the bottom cover and the base surface cover according to the embodiment.

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 of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention.

Example (b):

as shown in fig. 1 to 9, the present embodiment discloses a temperature controller applied to a thermal insulation electric kettle, which comprises a temperature controller main body 1, a water boiling temperature sensing component 2, a thermal insulation temperature sensing component 3 and a dry-burning temperature sensing component 4 mounted on the temperature controller main body 1, wherein the water boiling temperature sensing component 2 is connected with a water boiling switch 5 for controlling the switch of the water boiling temperature sensing component 2, the thermal insulation temperature sensing component 3 is connected with a temperature regulator 6 for regulating the thermal insulation temperature, the circuit input end of the dry-burning temperature sensing component 4 is connected with a fire wire, the circuit output end of the dry-burning temperature sensing component 4 is connected with the water boiling temperature sensing component 2 and the thermal insulation temperature sensing component 3, the water boiling temperature sensing component 2 and the thermal insulation temperature sensing component 3 are arranged in parallel, the circuit output end of the water boiling temperature sensing component 2 and the circuit output end of the thermal, the circuit output end of the heater 7 is connected with a zero line, the dry-burning temperature sensing part 4 comprises a dry-burning temperature sensing sheet 41 for sensing the heating temperature of the electric kettle, a dry-burning movable contact sheet 42 and a dry-burning static contact sheet 43 which are used for mutually matching to control the on-off of the internal circuit of the dry-burning temperature sensing part 4, a linkage rod 44 is arranged between the dry-burning temperature sensing sheet 41 and the dry-burning movable contact sheet 42 to carry out linkage action, a secondary dry-burning prevention mechanism 8 for preventing the electric kettle from secondary dry burning and a reset mechanism 9 for driving the secondary dry-burning prevention mechanism 8 to reset after action are arranged in the dry-burning temperature sensing part 4, and the secondary dry-burning prevention mechanism 8 and the reset mechanism 9 are arranged in the dry-burning temperature sensing part 4, so that the electric kettle can effectively avoid repeated dry burning under the heat preservation state, and safety accidents are. In this embodiment, the water boiling temperature sensing component 2 is a steam switch, and the heat preservation temperature sensing component 3 is a KST adjustable temperature controller, wherein the specific implementation structures of the water boiling temperature sensing component 2, the heat preservation temperature sensing component 3, the dry-fire temperature sensing component 4, the water boiling switch 5, and the temperature regulator 6 are disclosed in the prior art, and the specific implementable structures are many, and are not described in detail herein.

The electric kettle of the embodiment forms two heating circuit loops:

the first circuit: the live wire → the dry burning temperature sensing part 4 → the water burning temperature sensing part 2 → the heater 7 → the zero line;

a second circuit: live wire → dry-fire temperature sensing part 4 → heat preservation temperature sensing part 3 → heater 7 → zero line.

Through the circuit control arrangement of the double loops, the electric kettle of the invention has the following basic functions: firstly, automatically cutting off power after water is boiled; heating water and then automatically keeping the temperature; thirdly, continuously preserving heat; and fourthly, automatically cutting off power during dry burning.

In addition, the electric kettle has higher safety configuration by arranging the secondary dry-burning prevention mechanism 8 and the reset mechanism 9 which are linked with the dry-burning temperature sensing part 4 to act, the electric kettle is locked in a power-off state after being dried by the secondary dry-burning prevention mechanism 8, the reset mechanism 9 needs to be manually operated to reset, and the electric kettle can be restarted after being reset, so that the secondary dry burning of the electric kettle is avoided.

The working principle of the invention is as follows:

in a normal use state: the dry-burning movable contact piece 42 is contacted with the dry-burning static contact piece 43, the internal circuit of the dry-burning temperature sensing part 4 is communicated, and the secondary dry-burning prevention mechanism 8 is pushed to be in a static state by the dry-burning movable contact piece 42;

dry burning occurs: the dry-fire temperature sensing piece 41 deforms under the change of temperature, the dry-fire temperature sensing piece 41 drives the dry-fire movable contact piece 42 to act through the linkage rod 44, so that the dry-fire movable contact piece 42 is separated from the dry-fire static contact piece 43, the internal circuit of the dry-fire temperature sensing part 4 is disconnected, meanwhile, the dry-fire movable contact piece 42 is also separated from the secondary dry-fire prevention mechanism 8, the secondary dry-fire prevention mechanism 8 acts to lock the dry-fire movable contact piece 42 in a state of being separated from the dry-fire static contact piece 43, and the internal circuit of the dry-fire temperature sensing part 4 is kept disconnected;

and (3) recovering the circuit after dry burning: the dry-burning movable contact piece 42 is separated from the secondary dry-burning prevention mechanism 8 through the action of the reset mechanism 9, the reset mechanism 9 is restored to the state before the action, the dry-burning movable contact piece 42 is firstly restored to the state of being contacted with the dry-burning static contact piece 43, and then the secondary dry-burning prevention mechanism 8 is restored to the state of being pushed by the dry-burning movable contact piece 42 to be in a static state.

Preferably, the secondary dry combustion prevention mechanism 8 comprises a rotating head 81 and a rotating shaft 82, the rotating head 81 is installed on the rotating shaft 82, a pushing part 811 used for being in pushing contact with the dry combustion movable contact piece 42 in a normal use state, a locking part 812 used for locking the dry combustion movable contact piece 42 in a state of being separated from the dry combustion static contact piece 43 when dry combustion occurs and a resetting part 813 used for being linked with the resetting mechanism 9 when a circuit is restored after dry combustion are arranged in the rotating head 81, the rotating head 81 is of a square structure, the pushing part 811 is one side surface of the rotating head 81 facing the dry combustion movable contact piece 42, the locking part 812 is a bottom surface of the rotating head 81, and the resetting part 813 extends from the side surface of the pushing part 811 to a direction close to the dry combustion movable contact piece 42. The rotating shaft 82 is arranged at the eccentric position of the rotating head 81, and under the normal use state: the rotating head 81 has a torque rotating towards the direction of the dry-burning moving contact piece 42 relative to the rotating shaft 82, and the dry-burning moving contact piece 42 pushes against the pushing part 811 of the rotating head 81 to balance the torque of the rotating head 81, so that when the dry-burning moving contact piece 42 is separated from the rotating head 81, the rotating head 81 rotates around the rotating shaft 82 under the action of self gravity and the supporting force of the rotating shaft 82, and the rotation is stopped until reaching a new position with balanced stress. After dry burning occurs, the gravity center of the rotating head 81 and the axis of the rotating shaft 82 are on the same vertical plane, when the gravity center of the rotating head 81 and the axis of the rotating shaft 82 are on the same vertical plane, the rotating head 81 is balanced and stopped at the position, at this time, the locking part 812 extends to the upper part of the dry burning movable contact piece 42, so that the dry burning movable contact piece 42 is locked at a state separated from the dry burning static contact piece 43 through the locking part 812, even if the dry burning temperature sensing piece 41 is reset along with temperature reduction, the dry burning movable contact piece 42 is still separated from the dry burning static contact piece 43 under the action of the locking part 812, the dry burning temperature sensing part 4 is in a power-off state, and both the circuit I and the circuit II are in a power-off state.

Preferably, the reset mechanism 9 includes a movable column 91 capable of moving up and down and a reset head 92 fixedly disposed at one side of the movable column 91, the reset head 92 includes a first step 921 for cooperating with the reset portion 813 and a second step 922 for cooperating with the dry-burned contact 42, the first step 921 extends above the reset portion 813, the second step 922 extends above the dry-burned contact 42, and the first step 921 is lower than the second step 922. As shown in fig. 11, the bottom of the thermostat main body 1 is provided with a bottom cover 10, the bottom cover 10 is provided with a through hole 101 for the movable column 91 to penetrate out, a base surface cover 11 is arranged below the bottom cover 10, the base surface cover 11 is provided with a plurality of pits 111 corresponding to the through hole 101, a cylindrical hole is formed in the movable column 91, a spring 12 is installed in the cylindrical hole, the spring 12 is used for providing a downward pushing elastic force for the movable column 91, an external member 93 for moving the movable column 91 in a movable manner is further sleeved on the outer side of the movable column 91, an open groove 931 extending from the reset head 92 is formed in the external member 93, and a limit step 932 for limiting the downward moving stroke of the movable column 91 is arranged at the bottom of the open groove 931. The movable column 91 and the reset head 92 are of an integrally formed structure, the movable column 91 can move up and down along the sleeve member 93, the reset head 92 is driven to move up and down along the open slot 931, and when the reset head 92 moves down to the limiting step 932, the limiting step 932 limits the reset head 92. Meanwhile, in order to allow the moving post 91 to smoothly move downward by protruding out of the through hole, a push-down elastic force for providing a downward movement to the moving post 91 is provided at the top of the moving post 91.

The action principle of the secondary dry burning prevention mechanism 8 and the reset mechanism 9 is as follows:

in a normal use state: the dry-fire temperature sensing piece 41 is in an original non-deformation state, the dry-fire movable contact piece 42 and the dry-fire static contact piece 43 are closed, the rotating head 81 is in a state that the center of gravity and the axis of the rotating shaft are on different vertical planes, the dry-fire movable contact piece 42 is pushed against the pushing part 811 to stop the rotating head 81 at the current position, the moving column 91 and the reset head 92 are in an upper position, and the reset head 92, the rotating head 81 and the dry-fire movable contact piece 42 are in a separated state;

dry burning occurs: the dry-burning temperature sensing piece 41 is deformed under the influence of temperature, the dry-burning temperature sensing piece 41 presses the dry-burning movable contact piece 42 downwards through the linkage rod 44, so that the dry-burning movable contact piece 42 is separated from the dry-burning static contact piece 43, the circuit is broken, the dry-burning movable contact piece 42 is elastically deformed in the pressing-down process, the abutting position of the dry-burning movable contact piece 42 and the abutting part 811 gradually moves downwards until the dry-burning movable contact piece 42 is separated from the abutting part 811, the acting force of the dry-burning movable contact piece 42 on the rotating head 81 disappears, the rotating head 81 is in an unbalanced state, the rotating head 81 rotates around the rotating shaft 82, the locking part 812 of the rotating head 81 rotates and extends to the position above the dry-burning movable contact piece 42 to lock the dry-burning movable contact piece 42 in the state of being separated from the dry-burning static contact piece 43, and;

and (3) recovering the circuit after dry burning: the electric kettle is lifted upwards, a vacant position allowing the movable column 91 to extend out is formed below the through hole, the movable column 91 and the reset head 92 move downwards together, the reset part 813 is pressed downwards by the first step 921 on the reset head 92, the rotary head 81 rotates around the rotating shaft 82 in the opposite direction, meanwhile, the second step 922 on the reset head 92 is pressed downwards to separate the rotary head 81 from the dry burning movable contact piece 42, after the first half of circuit recovery action is completed, the electric kettle is put down, the base of the electric kettle jacks the movable column 91, the reset head 92 rises to the high position along with the rotary head 81, the rotary head 81 and the dry burning movable contact piece 42 are in an unbalanced state, at the moment, the dry burning movable contact piece 42 is reset firstly under the action of elastic force and is closed with the dry burning static contact piece 43, the rotary head 81 is reset, and the pushing part 811 is pushed against one end of the dry burning movable contact piece 42, so that the circuit recovery action after the dry burning is.

Preferably, one end of the rotating shaft 82 is fixedly disposed at one side of the sleeve 93, the other end extends outward, and the rotating head 81 is further provided with a clearance 814 for avoiding interference when the reset mechanism 9 and the secondary dry burning prevention mechanism 8 act.

As shown in fig. 10, the force analysis of the whole operation process of the secondary dry-burning prevention mechanism of the present embodiment is as follows: when the rotary head is in a normal use state, the direction of the rotary head is vertically downward under the self gravity G, the dry-burning movable contact piece is propped against the propping part of the rotary head to apply a propping force F to the rotary head₁，F₁Is perpendicular to the pushing part, and the rotating shaft applies a supporting force F to the rotating head₂，F₂The direction of the rotating shaft extends along a reverse extension line of a connecting line between the gravity center of the rotating head and the axis of the rotating shaft, and at the moment, the stress of the rotating head is balanced;

② when the electric kettle is dry-burned to make the dry-burned movable contact piece separate from the pushing part, the rotating head is vertically downward under the gravity G, the rotating shaft applies a supporting force F to the rotating head₂，F₂The direction of the rotating head extends along a reverse extension line of a connecting line between the gravity center of the rotating head and the axis of the rotating shaft, at the moment, the stress of the rotating head is unbalanced, and the rotating head rotates around the rotating shaft;

thirdly, when the rotating head rotates to the state that the gravity center of the rotating head and the axis of the rotating shaft are on the same vertical plane, the rotating head is subjected to the self gravity G, the direction of the G is vertical and downward, the dry-burning movable contact piece is abutted against the locking part of the rotating head and is applied to the rotating head to form an abutting force F₁The rotary shaft applying a supporting force F to the rotary head₂，F₁And F₂The direction is vertical and upward, and at the moment, the stress of the rotating head is balanced;

fourthly, when the electric kettle is dried and the circuit is recovered through the reset mechanism, the rotating head is under the gravity G, the G direction is vertically downward, the dry-burning movable contact piece is propped against the locking part of the rotating head to apply a propping force F to the rotating head₁The rotating shaft is applied to the rotating head IA supporting force F₂，F₁And F₂Are all vertically upward, the reset head of the reset mechanism is pressed down to the reset part of the rotating head to apply a downward pressure F to the rotating head₃，F₃The direction of the rotating head is vertical to the reset part, at the moment, the stress of the rotating head is unbalanced, and the rotating head rotates around the rotating shaft;

when the reset head is pressed to the lowest position, the dry burning contact piece is separated from the rotating head, the rotating head is under the gravity G, the direction of G is vertical and downward, the rotating shaft applies a supporting force F to the rotating head₂，F₂Is extended along a reverse extension line of a connecting line between the gravity center of the rotating head and the axis of the rotating shaft, and a reset head of the reset mechanism is pressed down to a reset part of the rotating head to apply a downward pressure F to the rotating head₃，F₃Is perpendicular to the reset part, and at the moment, the stress of the rotating head is balanced;

sixthly, the resetting mechanism resets, when the resetting head rises to the highest position, the rotating head is vertically downwards under the self gravity G and G, and the rotating shaft applies a supporting force F to the rotating head₂，F₂The direction of the rotating head extends along a reverse extension line of a connecting line between the gravity center of the rotating head and the axis of the rotating shaft, at the moment, the stress of the rotating head is unbalanced, and the rotating head rotates around the rotating shaft;

and the rotating head is reset to a normal use state under the action of the reset mechanism, and the stress condition of the rotating head is the same as that of the rotating head.

The above description is only a preferred embodiment of the present invention, and the technical solutions that achieve the objects of the present invention by substantially the same means are within the protection scope of the present invention.