CN111465131A - Temperature measurement feedback electromagnetic induction heating body based on thick film technology - Google Patents

Abstract

The invention discloses a temperature measurement feedback electromagnetic induction heating body based on thick film technology, which comprises an eddy current heating body base material, the eddy current heating body base material generates heat through a current changed in an electromagnetic coil; the surface of the eddy current heating body base material is provided with an insulating coupling Material layer, a thermistor wire layer is arranged on the surface of the insulating coupling material layer, and the insulating coupling material layer relatively insulates the thermistor wire layer from the eddy current heating element base material, and at the same time produces a better adhesion effect; the thermistor wire layer is located at On the loop of the sensor circuit, and the resistance value of the thermistor wire layer changes with temperature, the sensor circuit detects the temperature according to the resistance value change of the thermistor wire layer; since the thermistor wire layer directly detects the temperature of the eddy current heating element substrate, The temperature can be accurately detected in real time, which is more direct than detecting the temperature of the heated object.

Description

A temperature measurement feedback electromagnetic induction heating element based on thick film technology

technical field

The invention relates to the technical field of electromagnetic induction heating, and further relates to a temperature measurement feedback electromagnetic induction heating body based on thick film technology.

Background technique

At present, the electromagnetic induction heating device on the market is composed of electromagnetic coil + eddy current heating element. The eddy current heating element of the cylindrical coil is placed in the middle of the coil, and the eddy current heating element of the flat coil is placed on the upper or lower part of the coil. The alternating current generated by the induction heating power supply generates an alternating magnetic field through the electromagnetic coil), and the eddy current heating body is placed in the range of its magnetic field to cut the alternating magnetic field lines, and an alternating current (ie, eddy current) is generated inside the eddy current heating body to heat up and heat up Objects in contact with eddy current heating elements.

The temperature of the object to be heated needs to be monitored during the heating process. Generally, the magnetic field strength or output time of the electromagnetic coil is adjusted through the feedback signal of the thermocouple installed in the object to be heated for temperature control, as shown in Figure 1. The schematic diagram of the thermocouple temperature measurement structure, the current change of the coil 01 makes the eddy current heating body 02 generate heat, the eddy current heating body 02 heats the object placed inside, and the thermocouple 03 is inserted into the heating object to measure the temperature. Current feedback regulation of coil 01.

This temperature control method belongs to indirect measurement, which has the problems of long response time and large measurement error, and it is difficult to accurately realize temperature feedback; at the same time, because the thermocouple is generally made of metal, it is easily affected by the magnetic field of the electromagnetic coil, and the reliability is low. The temperature measurement method is single-point temperature measurement, and the phenomenon of uneven temperature distribution cannot be effectively identified.

For those skilled in the art, how to measure temperature accurately in real time is a technical problem that needs to be solved at present.

SUMMARY OF THE INVENTION

The present invention provides a temperature measurement feedback electromagnetic induction heating element based on thick film technology, which can directly measure the temperature of the eddy current heating element base material, and can realize real-time accurate temperature measurement. The specific scheme is as follows:

A temperature measurement feedback electromagnetic induction heating element based on thick film technology, comprising an eddy current heating element base material, and the eddy current heating element base material generates heat through an electromagnetic coil;

The surface of the eddy current heating element base material is provided with an insulating coupling material layer, and the surface of the insulating coupling material layer is provided with a thermistor line layer, and the thermistor line layer is located on the loop of the sensor circuit; the thermistor line The resistance of the layers varies with temperature.

Optionally, a cover protection layer is provided on the surface of the insulating coupling material layer, and the thermistor wire layer is wrapped in the cover protection layer; the electromagnetic coil is attached to the surface of the cover protection layer;

The thermistor wire layer is connected to a pad circuit, and the pad circuit extends to the edge of the cover protection layer and is connected to a lead.

Optionally, the thickness of the insulating coupling material layer is 10-200 microns, the thickness of the thermistor line layer is 5-20 microns, the thickness of the pad circuit is 5-20 microns, and the cover protection The thickness of the layers is 10-100 microns.

Optionally, the insulating coupling material layer, the thermistor wire layer, the pad circuit, and the cover protection layer are processed by screen printing.

Optionally, the thermistor wire layer is specifically a negative temperature coefficient sensor, a positive temperature coefficient sensor, or a platinum resistance sensor.

Optionally, the insulating coupling material layer is glass-ceramic.

The invention provides a temperature measurement feedback electromagnetic induction heating body based on thick film technology, comprising an eddy current heating body base material, the eddy current heating body base material generates heat through the current changed in the electromagnetic coil; the surface of the eddy current heating body base material is provided with insulating coupling Material layer, a thermistor wire layer is arranged on the surface of the insulating coupling material layer, and the insulating coupling material layer relatively insulates the thermistor wire layer from the eddy current heating element base material, and at the same time produces a better adhesion effect; the thermistor wire layer is located at On the loop of the sensor circuit, and the resistance value of the thermistor wire layer changes with temperature, the sensor circuit detects the temperature according to the resistance value change of the thermistor wire layer; since the thermistor wire layer directly detects the temperature of the eddy current heating element substrate, The temperature can be accurately detected in real time, which is more direct than detecting the temperature of the heated object.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative efforts.

1 is a schematic diagram of an existing thermocouple temperature measurement structure;

FIG. 2 is a structural diagram of a specific embodiment of the temperature measurement feedback electromagnetic induction heating body based on the thick film technology provided by the present invention.

The figure includes:

Eddy current heating element base material 1 , insulating coupling material layer 2 , thermistor wire layer 3 , pad circuit 4 , cover protective layer 5 , electromagnetic coil 6 , lead wire 7 .

Detailed ways

The core of the present invention is to provide a temperature measurement feedback electromagnetic induction heating element based on thick film technology, which can directly measure the temperature of the eddy current heating element substrate and can realize real-time accurate temperature measurement.

In order to make those skilled in the art better understand the technical solutions of the present invention, the temperature measurement feedback electromagnetic induction heating element based on the thick film technology of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

As shown in FIG. 2, it is a structural diagram of a specific embodiment of a temperature measurement feedback electromagnetic induction heating body based on thick film technology provided by the present invention, which includes an eddy current heating body substrate 1, an insulating coupling material layer 2, a thermistor The structure of the wire layer 3, the electromagnetic coil 6, etc., the eddy current heating body base material 1 generates heat through the electromagnetic coil 6, and the electromagnetic coil 6 is connected with the induction heating power supply. The current generates an alternating magnetic field that passes through the workpiece, and the eddy current heating element substrate 1 cuts the alternating magnetic field lines, thereby generating an alternating current inside. The eddy current makes the atoms inside the object move randomly at high speed, and the atoms collide and rub against each other to generate heat energy. Thereby heating the article, that is, by converting electrical energy into magnetic energy, the heated body induces the magnetic energy to generate heat.

The eddy current heating element base material 1 can be in the shape of a barrel or a flat plate. According to different heating objects, the thermistor wire layer 3 can be made into different shapes; the thermistor wire layer 3 can be bent on the surface to form different shapes as required. , to achieve a large-area area design on the eddy current heating element substrate 1, and the thermistor wire layer 3 covers a larger area to achieve a wide range of temperature measurement.

The surface of the eddy current heating element base material 1 is provided with an insulating coupling material layer 2, and the surface of the insulating coupling material layer 2 is provided with a thermistor wire layer 3; At the same time, the insulating coupling material layer 2 has good adhesion ability, which can make the eddy current heating element substrate 1 and the thermistor wire layer 3 more closely combined; The heat of the heating element base material 1 is rapidly transferred to the thermistor wire layer 3 .

The thermistor wire layer 3 is located on the loop of the sensor circuit. The resistance value of the thermistor wire layer 3 changes with temperature. The sensor circuit detects the resistance value change of the thermistor wire layer 3 and obtains the corresponding temperature according to the resistance value change.

The temperature measurement feedback electromagnetic induction heating body based on the thick film technology of the present invention is designed based on the thick film circuit. The thick film circuit is a kind of integrated circuit. A circuit unit with a certain function is formed. The thick film circuit referred to here mainly refers to the thermistor wire layer 3 of the temperature sensor circuit provided on the insulating coupling material layer 2 .

The temperature measurement feedback electromagnetic induction heating element based on the thick film technology of the present invention uses a magnetic conductive substrate as the eddy current heating element substrate 1, and the thermistor wire layer 3 of the temperature sensor circuit is prepared on its surface, and the thermistor wire layer 3 Good thermal coupling is achieved by tightly connecting the insulating coupling material layer 2 with the eddy current heating element base material 1 . During operation, the heat generated by the eddy current heating element is directly transferred to the temperature sensor circuit closely connected to it through the insulating coupling material to achieve accurate and direct temperature measurement. At the same time, the thick film circuit is a non-magnetic material and will not be affected by the magnetic field of the electromagnetic coil. Due to the highly integrated characteristics of thick-film circuits, the thickness of the thick-film functional layer of the heater is only tens to hundreds of microns, so the entire component is light, thin and compact, and it is easy to combine with other components to achieve a highly integrated, lightweight and portable assembly. Reduce energy consumption.

On the basis of the above scheme, the surface of the insulating coupling material layer 2 is provided with a covering protective layer 5, the covering protective layer 5 is coupled with the insulating coupling material layer 2, and the thermistor wire layer 3 is wrapped in the covering protective layer 5 to prevent heat The varistor line layer 3 plays a protective role.

The electromagnetic coil 6 is attached to the surface of the cover protection layer 5 ; the thermistor wire layer 3 is connected to the pad circuit 4 , and the pad circuit 4 extends to the edge of the cover protection layer 5 . The width of the pad circuit 4 is larger than that of the thermistor wire layer 3. At the edge of the covering protective layer 5, a part of the pad circuit 4 is covered by the covering protective layer 5, and the other part is exposed. The exposed part of the pad circuit 4 is connected to the lead 7, through the Lead 7 is connected to the rest of the temperature sensor circuit.

Preferably, the thickness of the insulating coupling material layer 2 of the present invention is 10-200 microns, the thickness of the thermistor line layer 3 is 5-20 microns, the thickness of the pad circuit 4 is 5-20 microns, and the thickness of the covering protective layer 5 is 5-20 microns. The thickness is 10-100 microns, and the appropriate thickness is selected according to the voltage and power level used.

The insulating coupling material layer 2, the thermistor wire layer 3, the pad circuit 4, and the cover protective layer are processed by screen printing. The specific process is: insulation coupling paste→screen printing→drying→high temperature sintering→sensor circuit paste→screen printing→drying→high temperature sintering→pad conductor paste→screen printing→drying→high temperature sintering → Covering protective paste → screen printing → drying → high temperature sintering → lead welding → finished product.

Preferably, the thermistor wire layer 3 in the present invention is one of a negative temperature coefficient sensor, a positive temperature coefficient sensor, or a platinum resistance sensor. Negative temperature coefficient temperature sensor is a kind of thermistor whose resistance value decreases rapidly as the temperature rises; it is usually composed of two or three metal oxides, which are sintered into dense sintered ceramics in a high-temperature furnace. Very flexible. The positive temperature coefficient sensor is a kind of thermistor. The resistance value of the positive temperature coefficient sensor shows a step increase with the increase of temperature. The higher the temperature, the greater the resistance value. Platinum resistance sensor is adding metal platinum to the resistance. The resistance value of the resistance is different due to the temperature change. Due to the stable characteristics of platinum, it will not cause physical or chemical changes due to high and low temperature.

The insulating coupling material layer 2 in the present invention is preferably made of glass-ceramic, which has good insulation and thermal conductivity, and can be well connected with the eddy current heating element substrate 1, the thermistor wire layer 3, and the pad circuit 4. coupling.

The above description of the disclosed embodiments enables any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (6)

1. A temperature measurement feedback electromagnetic induction heating body based on a thick film technology is characterized by comprising an eddy current heating body base material (1), wherein the eddy current heating body base material (1) generates heat through an electromagnetic coil (6);

an insulating coupling material layer (2) is arranged on the surface of the eddy current heating body substrate (1), a thermistor wire layer (3) is arranged on the surface of the insulating coupling material layer (2), and the thermistor wire layer (3) is positioned on a loop of a sensor circuit; the resistance value of the thermistor line layer (3) changes along with the temperature.

2. A thermometric feedback electromagnetic induction heating body based on thick film technology according to claim 1, characterized in that the surface of the insulating coupling material layer (2) is provided with a covering protective layer (5), and the thermistor wire layer (3) is wrapped in the covering protective layer (5); the electromagnetic coil (6) is attached to the surface of the covering protective layer (5);

the thermistor wire layer (3) is connected with a pad circuit (4), and the pad circuit (4) extends to the edge of the covering protective layer (5) and is connected with a lead (7).

3. A thermometric feedback electromagnetic induction heating body based on thick film technology according to claim 2, characterized in that the thickness of said insulating coupling material layer (2) is 10-200 microns, the thickness of said thermistor wire layer (3) is 5-20 microns, the thickness of said pad circuit (4) is 5-20 microns, and the thickness of said covering protective layer (5) is 10-100 microns.

4. The thermometric feedback electromagnetic induction heating body based on the thick film technology according to claim 3, characterized in that the insulating coupling material layer (2), the thermistor wire layer (3), the pad circuit (4), the covering protective layer are processed by screen printing.

5. A thermometric feedback electromagnetic induction heating body based on thick film technology according to claim 3, characterized in that said thermistor wire layer (3) is specifically a negative temperature coefficient sensor, or a positive temperature coefficient sensor, or a platinum resistance sensor.

6. A thermometric feedback electromagnetic induction heating body based on thick film technology according to claim 3, characterized in that said insulating coupling material layer (2) is microcrystalline glass.

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