CN201054814Y - Overheat protector for magnet exciting coil of electromagnetic oven - Google Patents

Abstract

The utility model provides an overheated protector of electromagnetism stove excitation coil, the electromagnetism stove includes excitation coil, coil plate rail (1), control circuit and power supply unit, excitation coil regularly twines on coil plate rail (1), especially, overheated protector includes thermistor (2) and sets up buckle structure (11) and fixed block (12) that are used for laying this thermistor (2) in the bottom outside of coil plate rail (1), two pins and the control circuit electricity of thermistor (2) are connected. The thermistor (2) is made into a U shape and is fixed on the fixing block (12) by the aid of grooves (121 and 122), and the fixing block (12) provided with the thermistor (2) is fixed on the outer side of the bottom of the heating coil disc (1) by the aid of a buckling structure (11). The power supply of the heating coil can be cut off in time by the thermistor (2), the heating coil is prevented from being burnt out, and the service life of the induction cooker is prolonged.

Description

Overheat protection device for excitation coil of induction cooker

technical field

The utility model relates to a household stove heated by electric energy, in particular to an overheat protection device used for an excitation coil of an electromagnetic cooker and using a thermistor as a sensing element.

Background technique

The induction cooker uses an AC power supply to generate an alternating magnetic field by means of an excitation coil, and eddy currents are generated at the bottom of the metal pan to generate heat. It is widely used in modern household kitchen utensils. However, the materials and structures of the pots used with the induction cooker are different, and the pots with inappropriate materials will cause the local temperature of the excitation coil of the induction cooker to rise sharply, causing the excitation coil and its coil frame of the induction cooker to be burned. , and even cause safety accidents, reducing the service life of the induction cooker.

Contents of the invention

The technical problem to be solved by the utility model is to avoid the deficiencies of the prior art and propose an overheat protection device that cuts off the power supply of the excitation coil in time when the temperature of the excitation coil of the induction cooker reaches the warning temperature.

The utility model solves the technical problem and can realize by adopting the following technical solutions:

Design and manufacture an overheating protection device for the excitation coil of an electromagnetic oven, the electromagnetic oven includes an excitation coil, a coil frame, a control circuit and a power supply device, the excitation coil is regularly wound on the coil frame, especially, the overheating The protection device includes a thermistor, a buckle structure and a fixing block arranged at the bottom of the coil frame for placing the thermistor, and the two pins of the thermistor are electrically connected to the control circuit.

The buckle structure is arranged outside the bottom of the coil frame, and the buckle structure includes two parallel vertical walls extending outward from the bottom of the coil frame, and the end planes of the two vertical walls are inclined downward toward their opposite faces and protruding, so as to form a buckle mechanism between the two vertical walls; the fixed block is a cube made of high temperature resistant material, installed between the two vertical walls by means of a buckle structure, and the fixed block is not in contact with the vertical wall The two opposite sides are provided with positioning grooves; the thermistor is columnar and made into a letter "U" shape, and a sleeve made of insulating material is placed on the sleeve of the thermistor; the sleeve is sleeved The thermistor is fixed on the fixing block by means of a groove, and the fixing block equipped with the thermistor is fixed on the outside of the bottom of the heating coil disk by means of a buckle structure. Radiation oil is coated between the fixed block and the vertical wall.

The thermistor is electrically connected to the control circuit of the induction cooker by means of a connecting plug, and the two pins of the thermistor are electrically connected to the connecting plug by means of wires.

Compared with the prior art, the technical effect of the utility model "the overheat protection device for the excitation coil of the induction cooker" lies in:

1. If the pot with inappropriate material quality is used, and the excitation coil of the induction cooker is partially overheated and exceeds the warning temperature, the power supply of the excitation coil can be cut off in time with the help of the thermistor to prevent the excitation coil and the coil frame from being overheated. burnt out;

2. The overheating protection device prevents the excitation coil of the induction cooker from overheating, prolonging the service life of the induction cooker.

Description of drawings

Fig. 1 is a schematic diagram of the axonometric projection of the excitation coil frame of an induction cooker provided with an overheat protection device, the bottom surface of the coil frame faces upward;

Fig. 2 is a schematic diagram of the disassembled state of Fig. 1;

Fig. 3 is a schematic diagram of the control circuit of the induction cooker.

Detailed ways

Further details will be given below in conjunction with the embodiments shown in the accompanying drawings.

The utility model is an overheat protection device for the excitation coil of an electromagnetic oven. The electromagnetic oven includes an excitation coil, a coil frame 1, a control circuit and a power supply device. The excitation coil is regularly wound on the coil frame 1. In particular, the overheating The protection device includes a thermistor 2 and a bayonet structure 11 and a fixing block 12 for placing the thermistor 2 arranged on the bottom outside of the coil frame 1, and the two pins of the thermistor 2 are connected with the control The circuit is electrically connected.

As shown in FIG. 1 and FIG. 2 , the buckle structure 11 is arranged outside the bottom of the coil frame 1 , and the buckle structure 11 includes two parallel vertical walls 111 extending outward from the bottom of the coil frame 1 , 112, the end planes of the two vertical walls 111, 112 are inclined downward and protrude toward their opposite faces, thereby forming a buckle mechanism between the two vertical walls 111, 112; the fixing block 12 is made of high temperature resistant material The cube is installed between two vertical walls 111, 112 by means of a buckle structure 11, and positioning grooves 121, 122 are provided on the two opposite sides of the fixed block 12 that are not in contact with the vertical walls 111, 112; the thermistor 2 It is columnar and made into the shape of the letter "U". The thermistor 2 is covered with a sleeve 21 made of insulating material; the thermistor 2 covered with the sleeve 21 is fixed by means of grooves 121, 122 On the fixing block 12 , the fixing block 12 equipped with the thermistor 2 is fixed on the outside of the bottom of the heating coil disk 1 by means of the buckle structure 11 .

In order to enable the thermistor 2 to accurately sense the temperature of the heating coil of the induction cooker, heat dissipation oil is applied between the fixed block 12 and the vertical walls 111 and 112 .

The thermistor 2 is electrically connected to the control circuit of the induction cooker by means of a connecting plug 3 , and the two pins of the thermistor 2 are electrically connected to the connecting plug 3 by means of wires. On the control circuit board, a connection socket corresponding to the connection plug 3 should be provided. This technology has been widely used in the field of circuit board design and will not be described in detail here.

The thermistor 2 has a nonlinear characteristic that the resistance value changes with the change of the ambient temperature, and the control circuit judges whether the temperature of the heating coil has reached the warning value according to the change of the resistance value of the thermistor 2, and if it reaches Warning value The control circuit cuts off the power supply of the heating coil, and when the temperature of the heating coil drops to a safe range, the control circuit turns on the power supply of the heating coil again. In the prior art, there are many kinds of circuits that can realize the above functions. In this preferred embodiment, the above functions are realized by detecting the voltage of the voltage divider circuit. As shown in FIG. 3 , R _NTC representing the thermistor 2 is connected in series with the voltage dividing resistor R, and the potential at point A in the figure is used as an overheating control signal for the control circuit of the induction cooker. According to the resistance value of the thermistor R _NTC when the warning temperature is reached, determine the resistance value of the voltage divider resistor R, that is, the voltage on the voltage divider resistor R should be the operating voltage of the control circuit at this time. As the temperature of the heating coil increases, the resistance of the thermistor R _NTC decreases, and the voltage of the divider resistor R increases. When the temperature of the heating coil reaches a warning value, the potential at point A increases to The operating voltage value of the control circuit, that is, the overheating control signal is valid, the control circuit cuts off the power supply of the heating coil, so that the heating coil no longer heats up; when the temperature of the heating coil drops to a safe range, the thermistor R The resistance value of _NTC increases, thereby reducing the voltage on the voltage dividing resistor R, the potential of point A is lower than the operating voltage of the control circuit, that is, the overheating control signal is invalid, the power supply of the heating coil is turned on, and it is in the heating working state again .

The overheat protection device of the heating coil of the induction cooker makes the heating coil work in a safe temperature range by virtue of the non-linear characteristics of the thermistor, preventing local overheating and prolonging the service life of the induction cooker.

Claims (4)

1. an overheat protection device for the excitation coil of an electromagnetic oven, the electromagnetic oven comprises an excitation coil, a coil frame (1), a control circuit and a power supply unit, and the excitation coil is regularly wound on the coil frame (1), which Characterized by: The overheating protection device includes a thermistor (2) and a buckle structure (11) and a fixing block (12) arranged at the bottom of the coil frame (1) for accommodating the thermistor (2), The two pins of the thermistor (2) are electrically connected with the control circuit. 2. The overheat protection device for the excitation coil disk of an electromagnetic oven according to claim 1, characterized in that: the buckle structure (11) is arranged outside the bottom of the coil frame (1), and the buckle structure (11) ) includes two parallel vertical walls (111, 112) extending outward from the bottom of the coil frame (1), and the end planes of the two vertical walls (111, 112) are inclined downward and protrude toward their opposite faces, so that A buckle mechanism is formed between the two vertical walls (111, 112); the fixed block (12) is a cube made of high temperature resistant material, and is installed between the two vertical walls (111, 112) by means of the buckle structure (11), Positioning grooves (121, 122) are provided on the two opposite sides of the fixed block (12) that are not in contact with the vertical walls (111, 112); the thermistor (2) is columnar, and is made into the letter " U" shape, the thermistor (2) is covered with a sleeve (21) made of insulating material; the thermistor (2) with the sleeve (21) is covered with grooves (121, 122) It is fixed on the fixing block (12), and the fixing block (12) equipped with the thermistor (2) is fixed on the outside of the bottom of the heating coil disk (1) by means of a buckle structure (11). 3. The overheating protection device for the excitation coil of an electromagnetic oven according to claim 2, characterized in that heat dissipation oil is coated between the fixed block (12) and the vertical walls (111, 112). 4. The overheat protection device for the excitation coil of an electromagnetic oven according to claim 1, characterized in that: The thermistor (2) is electrically connected to the control circuit of the induction cooker by means of a connecting plug (3), and the two pins of the thermistor (2) are electrically connected to the connecting plug (3) by means of wires.

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