CN210641092U

CN210641092U - Miniature electric heating rod

Info

Publication number: CN210641092U
Application number: CN201921374391.8U
Authority: CN
Inventors: 姚剑浩
Original assignee: Jiaxing Wisdom Electronics Co ltd
Current assignee: Jiaxing Wisdom Electronics Co ltd
Priority date: 2019-08-22
Filing date: 2019-08-22
Publication date: 2020-05-29
Anticipated expiration: 2029-08-22

Abstract

A miniature electric heating rod comprises a cylindrical base rod (1), wherein an electric heating layer (2) made by a cylindrical thick film printing method is wrapped on the cylindrical surface of the base rod, and an electrode (3) made by the cylindrical thick film printing method is arranged on the electric heating layer. The electric heating layer consists of three layers: the bottom layer is a dielectric insulating layer (4), the middle layer is a resistance layer (5), and the upper layer is a dielectric insulating protective layer (6). The electric heating layer of the miniature electric heating rod is made by a cylindrical thick film printing method, and the thickness of each film is generally 10-20 microns, and the size is uniform. Compared with a ceramic film winding type heating rod, the heating body can be designed to be wider due to the fact that a winding film is omitted, the circumferential length of a round rod with the same outer diameter is fully utilized, the heating body with higher power can be designed to be possible, and the service life is greatly prolonged.

Description

Miniature electric heating rod

Technical Field

The utility model relates to a structure of an electric heating device, in particular to a miniature electric heating rod.

Background

The electric heating rod is a device for electric heating, is generally cylindrical, and can be realized by manufacturing a resistance layer on the outer surface of a ceramic cylinder. Ceramic electric heating rods with a diameter less than 4mm, such as electric soldering irons, electronic cigarettes and other electric heating rods requiring a small size, are difficult to manufacture a uniform resistance layer on the outer surface of the cylinder. The existing method is to print a resistance layer on the surface of a ceramic raw material film, then to roll the ceramic film on a ceramic cylinder, and to make an electric heating rod by isostatic pressing, high temperature sintering and other processes, which results in complex structure and process and low yield. Chinese patent 201410439924.1 describes a cylindrical thick film printing apparatus which is capable of screen printing a paste onto the cylindrical surface of a cylindrical workpiece.

Disclosure of Invention

The utility model aims at providing a structure of miniature electric bar can utilize face of cylinder thick film printing device to make qualified product.

The miniature electric heating rod comprises a cylindrical base rod, wherein an electric heating layer made by a cylindrical thick film printing method is wrapped on the cylindrical surface of the base rod, and an electrode made by the cylindrical thick film printing method is arranged on the electric heating layer.

The miniature electric heating rod has precise size because the electric heating layer and the electrode are made by a cylindrical thick film printing method, and compared with the heating rod in a ceramic film winding mode, the miniature electric heating rod has the advantages that the winding film is eliminated, the circumferential length of the round rod with the same outer diameter is fully utilized, the heating body can be designed to be wider, the design of the heating body with higher power is possible, and the service life is greatly prolonged.

Drawings

FIG. 1 is a front view of a micro-electrothermal rod;

FIG. 2 is a back view of a micro-electrothermal rod;

FIG. 3 is an expanded view of the electric heating layer;

FIG. 4 is an expanded view of the underlying dielectric insulating layer of the electrical heating layer;

FIG. 5 is a development view of the electric heating layer after sintering of the electrodes;

FIG. 6 is an expanded view of the electrical heating layer after sintering the resistive layer;

FIG. 7 is a development view of the electric heating layer after sintering the upper dielectric insulating protective layer;

fig. 8 is a perspective view of a micro electric heating rod.

Detailed Description

As shown in fig. 1 and 2, the micro-electric heating rod comprises a cylindrical base rod 1, an electric heating layer 2 formed by a cylindrical thick film printing method is coated on the cylindrical surface of the base rod 1, and an electrode 3 formed by a cylindrical thick film printing method is arranged on the electric heating layer 2.

As shown in fig. 6 and 7, the electric heating layer 2 of this micro electric heating rod is composed of three layers: the bottom layer is a dielectric insulating layer 4, the middle layer is an electrode 3 and a resistance layer 5, the ends of the electrode and the resistance layer are in lap joint, and the upper layer is a dielectric insulating protective layer 6.

The resistive layer of the micro-heating rod can be designed in various shapes, for example, as shown in fig. 3 and 6, the resistance layer 5 is developed in an M-shape, and two electrodes 3 are provided at both ends of the M-shape. The electrodes are arranged at the same end of the electric heating rod and are convenient to be connected with a power supply.

The electric heating layer of the miniature electric heating rod is manufactured by a cylindrical thick film printing method, the thickness of each film is generally 10-20 microns, and the manufacturing process is as follows: a layer of dielectric insulating paste is printed on the base rod 1, and after sintering, the dielectric insulating layer 4 shown in fig. 4 is formed, which serves as an insulating layer and a transition carrier to increase the bonding strength of the resistance layer. Next, electrode paste is printed at the positions of the electrodes, and sintered to form the electrodes 3, which serve to draw out the resistance layer and enhance solderability, as shown in fig. 5. The resistor paste is then printed and sintered to form the resistor layer 5, which is used to generate heat when energized as shown in fig. 6. Finally, a layer of dielectric insulating paste is printed on the resistor layer 5, and then sintered to form a dielectric insulating protective layer 6, as shown in fig. 7, which is used for isolating the resistor layer from the outside, protecting the resistor layer, preventing oxidation, and insulating the resistor layer from the outside. The lower part of the electrode 3 is not covered by the dielectric insulating protective layer 6, leaving a welding position. Sintering is needed after printing a layer of slurry each time, and the sintering temperature is about 850 ℃, which depends on the type of the slurry.

The dielectric insulating slurry is glass slurry, which is prepared by grinding and mixing fine glass powder and carriers such as resin solvent and the like, printing the mixture on a cylinder, volatilizing the resin solvent after high-temperature sintering, softening and welding the glass powder to form a compact glass layer. The electrode paste is generally formed by grinding and mixing silver powder, glass powder, resin and a solvent, after the electrode paste is printed on a cylinder, the resin and the solvent are volatilized and burnt to leave silver paste and glass through high-temperature sintering, silver powder particles are fixed on a glass body, and meanwhile, the glass body is fused with a lower glass layer, so that the purpose of fixing the silver layer is achieved. The resistance paste is generally silver palladium paste, platinum paste or ruthenium paste, and is similarly prepared by adding glass powder, resin, solvent and the like to various powder materials and grinding and mixing. And printing and sintering to form a metal resistance layer, wherein the resistance is adjusted by the powder proportion. The thickness of the printing layer directly affects the resistance of the resistor, if the printing layer is thin, the resistor becomes larger, if the printing layer is thick, the resistor becomes smaller, and if the printing layer is not uniform, the thin part can be burnt out when being heated. Printing a consistent film thickness is critical to success.

The base material of the miniature electric heating rod can adopt an alumina rod, a zirconia rod, a quartz rod or a stainless steel tube. The miniature electric heating rod has wide application, can be applied to occasions which need heating and are limited by installation size, and can be used for an electronic cigarette, as shown in figure 8, the front end 7 of the base rod 1 is made into a conical shape, so that a cigarette end can be conveniently inserted. When the electric soldering iron is used on an electric soldering iron, the front end does not need to be made into a cone shape and is used as a heating element.

The electric heating layer and the electrode of the miniature electric heating rod are manufactured by a cylindrical thick film printing method, the thickness error of the printed film can be controlled to be below 10%, and the pattern size is accurate, so that the finished product of the miniature electric heating rod is stable in resistance. Experiments show that stable mass production can be obtained in the range of 1.7-4 mm in diameter of the base rod. Subversing the recognition that small diameter cylinders cannot achieve stable film thickness with printing methods traditionally thought. Compared with a ceramic film winding type heating rod with the same outer diameter, the effective circumference length is much longer (because the printing surface of the ceramic film winding type heating rod is required to be arranged on the inner surface of the film, the ceramic film is generally 0.3mm thick, the effective diameter of the heating rod is greatly reduced), the circular arc surface of the circumference is fully utilized, the resistance layer can be designed to be wider and can be uniformly distributed on the whole circumference surface, the interface defect caused by film wrapping is avoided, the appearance of the circumference surface is smooth and tidy, the design of the resistance layer with higher power is possible, and the service life is prolonged due to the widening of the width of the resistance layer. Meanwhile, because the winding film is eliminated, the resistance layer is arranged on the circumferential surface, the heat does not need to heat the outer winding film firstly and then is conducted to the outside, the heating rate is higher, and the heat efficiency is higher. Experiments show that the temperature rise rate of the cylinder with the same diameter and power can be improved by more than 4 times.

Claims

1. A miniature electric heating rod comprises a cylindrical base rod (1), and is characterized in that an electric heating layer (2) made by a cylindrical thick film printing method is wrapped on the cylindrical surface of the base rod (1), and an electrode (3) made by the cylindrical thick film printing method is arranged on the electric heating layer (2).

2. The miniature electric heating bar according to claim 1, characterized in that the electric heating layer (2) consists of three layers: the bottom layer is a dielectric insulating layer (4), the middle layer is an electrode and a resistance layer (5), and the upper layer is a dielectric insulating protective layer (6).

3. A miniature electric heating rod according to claim 1 or 2, characterized in that the development of the resistive layer (5) is M-shaped, with an electrode at each end of the M-shape.