A method for regulating resistance of a sheet heating element

Abstract

The application discloses a kind of sheet type heating element resistance regulation and control method, it is related to heating element field, for the initial resistance error of existing heating element up to ±10%, the yield is only 85-90% problem.The present application proposes the following scheme, it includes the heating circuit of primary forming is designed into adjustable form, the initial resistance error of each heating element is reduced by secondary finishing, specifically including calculating the resistance of heating circuit, based on the principle of resistance bridge, resistance regulation and control area is added in heating circuit.This method changes the width of 8 small rectangular heating areas by laser resistance adjustment after calculation, so as to achieve the purpose of changing the resistance of heating element, and the initial resistance error of each heating element is reduced by secondary finishing, to improve the yield.

Description

Technical Field

[0001] This invention relates to the field of heating elements, and more particularly to a method for adjusting the resistance of a plate heating element. Background Technology

[0002] Electric heating elements are components that convert electrical energy into heat energy, and various electric heating devices use them to generate heat. Since their invention, electric heating elements have played a vital role in people's production and daily lives. Currently, there are numerous categories of electric heating elements, including conventional types, electric heating alloys, electric heating materials, microwave heating devices, electromagnetic induction heating devices, electric heating wires, electric heating plates, electric heating tapes, electric heating cables, electric heating discs, thermocouples, electric heating coils, electric heating rods, electric heating tapes, electric heating cores, mica heating elements, ceramic heating elements, tungsten and molybdenum products, silicon carbide rods, molybdenum powder, tungsten bars, heating wires, mesh belts, and many other types of electric heating elements. Among these, plate heating elements are the most common type of electric heating element.

[0003] However, the resistance of the heating element is affected by factors such as the particle size of the conductive phase powder (ρ - resistivity), the screen printing thickness (S - area), and the sintering process, resulting in an initial resistance error of up to ±10% and a yield of only 85-90%. Therefore, we need a method for controlling the resistance of a plate heating element. Summary of the Invention

[0004] (a) Purpose of the invention

[0005] In view of this, the purpose of this invention is to provide a method for adjusting the resistance of a plate heating element in order to reduce the initial resistance error of the heating element.

[0006] (II) Technical Solution

[0007] To achieve the above technical objectives, the present invention provides a method for adjusting the resistance of a chip heating element:

[0008] A method for adjusting the resistance of a plate heating element involves designing a one-piece molded heating circuit into an adjustable form and reducing the initial resistance error of each heating element through secondary precision machining. The method specifically includes the following steps:

[0009] Step 1: Calculate the resistance of the heating circuit using the formula (1):

[0010]

[0011] In the formula: R is the resistance of the heating element, in units of... ; The resistivity of the slurry is expressed in units of . •m; L is the length of the heating circuit, in meters; S is the cross-sectional area of ​​the heating circuit, in cubic meters. 2 ;

[0012] Step 2: Based on the principle of a resistance bridge, a resistance control area is added inside the heating circuit. The resistance control area includes multiple small rectangular heating zones.

[0013] Step 3: The small rectangular heating area in Step 2 is equivalent to resistor R3, and the heating circuit connected to it is equivalent to R1, R2, R4, and R5 respectively. At this time, each small rectangular heating area in the resistance adjustment area will form a resistance bridge.

[0014] Step 4: Through the equivalent transformation of star and triangle, the resistance bridge in Step 3 is transformed into an equivalent circuit of resistance series and parallel that is easy to solve.

[0015] Step 5: According to the Δ-Y equivalent transformation formula, the Δ connection of R1, R2, and R3 in the circuit of Step 4 is transformed into a Y-type connection. The equivalent transformation formula is as follows:

[0016]

[0017]

[0018]

[0019] The equivalent resistance of the above-mentioned resistance bridge can be calculated using the following formula:

[0020]

[0021] Substituting equation 2-4 into equation 5 and simplifying appropriately, we get:

[0022]

[0023] Step 6: Based on the formula in Step 5, the resistance of the heating element can be changed by adjusting the width of the small rectangular heating area through laser trimming.

[0024] Preferably, the secondary finishing process includes selecting a silver-palladium conductive paste with excellent conductivity as the pad material for the heating element.

[0025] Preferably, the secondary finishing process includes using metallic silver as the heating element lead wire and alumina ceramic with good thermal conductivity as the heating element substrate material.

[0026] Preferably, the secondary finishing process includes using a platinum-based resistor with excellent heating performance and stability as the heating paste.

[0027] Preferably, the secondary finishing process further includes depositing a glaze layer on the surface of the heating element to enhance its surface smoothness.

[0028] Preferably, the number of the small rectangular heating areas is eight.

[0029] As can be seen from the above technical solutions, this application has the following beneficial effects:

[0030] This method designs an adjustable heating circuit in a single molding process. After calculation, the width of eight small rectangular heating zones is changed by laser trimming, thereby altering the resistance of the heating elements. Secondary finishing processes further reduce the initial resistance error of each heating element, improving the yield rate. Additionally, it addresses the issue of tar and tobacco residue adhering to the heating element surface during cigarette baking, reducing this adhesion and enhancing the element's cleanliness. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0032] Figure 1 is a schematic diagram of the resistance control region of a plate heating element resistance control method provided by the present invention.

[0033] Figure 2 is a schematic diagram of a resistance bridge for a method of controlling the resistance of a chip heating element provided by the present invention.

[0034] Figure 3 is a circuit diagram after equivalent transformation of the resistance control method of a chip heating element provided by the present invention.

[0035] Figure 4 is a schematic diagram of the secondary processing of a plate heating element resistance control method provided by the present invention. Detailed Implementation

[0036] The following description is exemplary in nature and is not intended to limit the scope, application, or use of this disclosure. The accompanying drawings are merely schematic representations of the concept and principles of embodiments of this disclosure and do not necessarily show the specific dimensions or scale of each embodiment. Certain details or structures of embodiments of this disclosure may be exaggerated in particular portions of certain drawings.

[0037] Example 1

[0038] A method for adjusting the resistance of a plate heating element involves designing a one-piece molded heating circuit into an adjustable form and reducing the initial resistance error of each heating element through secondary precision machining. The method specifically includes the following steps:

[0039] Step 1: Calculate the resistance of the heating circuit using the formula (1):

[0040]

[0041] In the formula: R is the resistance of the heating element, in units of... ; The resistivity of the slurry is expressed in units of . L is the length of the heating circuit, in meters (m); S is the cross-sectional area of ​​the heating circuit, in cubic meters (m²). 2 Specifically, as shown in Equation 1, the value of R can be corrected by changing L or S through secondary processing, thereby improving the accuracy of the initial resistance of the heating element.

[0042] Step 2: Based on the principle of the resistance bridge, a resistance control area is added inside the heating circuit. The resistance control area includes multiple small rectangular heating areas, as shown in Figure 1. There are eight small rectangular heating areas.

[0043] Step 3: The small rectangular heating area in Step 2 is equivalent to resistor R3, and the heating circuit connected to it is equivalent to R1, R2, R4, and R5 respectively. At this time, each small rectangular heating area in the resistance adjustment area will form a resistance bridge; as shown in Figure 2.

[0044] Step 4: Through the equivalent transformation of star and triangle, the resistor bridge in step 3 is transformed into an equivalent circuit of resistor series and parallel that is easy to solve, as shown in Figure 3.

[0045] Step 5: According to the Δ-Y equivalent transformation formula, the Δ connection of R1, R2, and R3 in the circuit of Step 4 is transformed into a Y-type connection. The equivalent transformation formula is as follows:

[0046]

[0047]

[0048]

[0049] The equivalent resistance of the above-mentioned resistance bridge can be calculated using the following formula:

[0050]

[0051] Substituting equation 2-4 into equation 5 and simplifying appropriately, we get:

[0052]

[0053] Step 6, based on the formula in Step 5, it should be noted that due to factors such as sintering process technology and slurry viscosity, the bridge circuit is in an unbalanced state in most cases. As shown in the above formula, when the resistance bridge is in an unbalanced state, the resistance of R3 changes, and the equivalent resistance of its equivalent circuit also changes. Therefore, by adjusting the laser resistance and changing the width of the small rectangular heating area, the resistance of the heating element can be changed. Specifically, the method for changing the initial resistance of the heating element is as follows... Figure 4 As shown.

[0054] It should be noted that the secondary finishing process also includes selecting a silver-palladium conductive paste with excellent conductivity as the pad material for the heating element. Metallic silver is used as the heating element lead wire, and alumina ceramic with good thermal conductivity is used as the heating element substrate material. Platinum-based resistance thermometers with excellent heating performance and stability are used as the heating paste.

[0055] Example 2

[0056] A method for adjusting the resistance of a plate heating element involves depositing a glaze layer on the surface of the heating element to enhance its smoothness, thereby reducing the adhesion of e-liquid and tobacco residue to the surface of the heating element and improving its cleanliness. This method effectively addresses the phenomenon of e-liquid and some tobacco residue adhering to the surface of the heating element during the heating process of cigarettes.

[0057] This method designs an adjustable heating circuit in a single molding process. After calculation, the width of eight small rectangular heating zones is changed by laser trimming, thereby altering the resistance of the heating elements. Secondary finishing processes further reduce the initial resistance error of each heating element, improving the yield rate. Additionally, it addresses the issue of tar and tobacco residue adhering to the heating element surface during cigarette baking, reducing this adhesion and enhancing the element's cleanliness.

[0058] The exemplary implementation of the solution proposed in this disclosure has been described in detail above with reference to preferred embodiments. However, those skilled in the art will understand that various modifications and alterations can be made to the above specific embodiments without departing from the spirit of this disclosure, and various combinations can be made to the various technical features and structures proposed in this disclosure without exceeding the protection scope of this disclosure, which is determined by the appended claims.

Claims

1. A method for adjusting the resistance of a plate heating element, characterized in that, The heating circuit, which is formed in one piece, is designed to be adjustable. The initial resistance error of each heating element is reduced through secondary precision machining. This process includes the following steps: Step 1: Calculate the resistance of the heating circuit using the formula (1): In the formula: R is the resistance of the heating element, in Ω; ρ is the resistivity of the slurry, in Ω. m; L is the length of the heating circuit, in meters (m); S is the cross-sectional area of ​​the heating circuit, in cubic meters (m). ; Step 2: Based on the principle of a resistance bridge, a resistance control area is added inside the heating circuit. The resistance control area includes multiple small rectangular heating zones. Step 3: The small rectangular heating area in Step 2 is equivalent to resistor R3, and the heating circuit connected to it is equivalent to R1, R2, R4, and R5 respectively. At this time, each small rectangular heating area in the resistance adjustment area will form a resistance bridge. Step 4: Through the equivalent transformation of star and triangle circuits, the resistor bridge in Step 3 is transformed into an equivalent circuit of resistor series and parallel that is easy to solve. Step 5: According to the Δ-Y equivalent transformation formula, the Δ connection of R1, R2, and R3 in the circuit of Step 4 is transformed into a Y-type connection. The equivalent transformation formula is as follows: The equivalent resistance of the above-mentioned resistance bridge can be calculated using the following formula: R = Ra + (Rc + R5) / / (R b + R4) (5) Substituting equation 2-4 into equation 5 and simplifying appropriately, we get: Step 6: Based on the formula in Step 5, when the resistor bridge is in an unbalanced state, the resistance value of R3 changes, and the equivalent resistance value of its equivalent circuit also changes. Therefore, by adjusting the laser resistance, the width of the small rectangular heating area can be changed, thereby changing the resistance value of the heating element.

2. The method for adjusting the resistance of a plate heating element according to claim 1, characterized in that, The secondary finishing process includes selecting a silver-palladium conductive paste with excellent conductivity as the pad material for the heating element.

3. The method for adjusting the resistance of a plate heating element according to claim 2, characterized in that, The secondary finishing process includes using metallic silver as the heating element lead wire and alumina ceramic with good thermal conductivity as the heating element substrate material.

4. A method for adjusting the resistance of a plate heating element according to claim 2 or 3, characterized in that, The secondary finishing process includes using platinum-based resistors with excellent heating performance and stability as heating paste.

5. The method for adjusting the resistance of a plate heating element according to claim 1, characterized in that, The secondary finishing process also includes depositing a glaze layer on the surface of the heating element to enhance its surface smoothness.

6. The method for adjusting the resistance of a plate heating element according to claim 1, characterized in that, The number of small rectangular heating zones is eight.

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