Forming die for thermal shock resistant coating of oxygen sensor

Abstract

The utility model discloses a forming die for a thermal shock resistant coating of an oxygen sensor. Comprising an upper template and a lower template, a positioning groove and a grouting groove are formed in the lower template, the depth of the grouting groove is larger than that of the positioning groove, the grouting groove is connected with the positioning groove, the structures of the grouting groove and the positioning groove are matched with the structure of an oxygen sensor chip core, ventilation channels communicated with the outside are symmetrically formed in the two sides of the grouting groove, and an injection groove communicated with the outside is formed in the front end of the grouting groove; the upper template and the lower template are symmetrical, the upper template and the lower template are detachably spliced and connected, the positioning grooves of the upper template and the lower template are spliced to form a positioning cavity, the grouting grooves are spliced to form a forming cavity, the injection grooves are spliced to form an injection port, the ventilation channels are spliced to form an exhaust hole, and the size of the forming cavity is larger than that of a part, needing to be coated, of an oxygen sensor chip. And a gap between the inner wall of the forming cavity and a to-be-coated part is uniform. A regular coating can be formed on a part needing to be coated through the forming cavity, and the coating is efficiently and conveniently manufactured.

Description

Technical Field

[0001] The utility model belongs to the technical field of oxygen sensors, and particularly relates to a thermal shock resistant coating forming die for an oxygen sensor. Background Art

[0002] During the cold start of the automobile engine, due to the presence of liquid condensed water during the cold start, it is very easy for the condensed water to drip into the high temperature area of ​​the normally working oxygen sensor core, causing the oxygen sensor core to crack and split during use. In order to prevent the condensed water in the front exhaust pipe from dripping into the high temperature area of ​​the oxygen sensor core due to the inevitable external dew point factors, causing abnormalities in the high temperature area of ​​the oxygen sensor heating, people add a thermal shock resistant coating to the high temperature area of ​​the oxygen sensor core, which greatly reduces the phenomenon of cracking and splitting of the oxygen sensor core during use.

[0003] The thermal shock resistant coating of existing oxygen sensor chips is generally made by spraying, dipping and coating. Except for plasma spraying, other processes are difficult to form regular shapes. The plasma spraying process has problems such as large equipment investment and low processing efficiency. How to design a mold that can efficiently and conveniently produce thermal shock resistant coatings and form regular shapes is a problem that needs to be solved.

[0004] The information disclosed in this background technology section is only intended to increase the understanding of the overall background of the present invention, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0005] The purpose of the utility model is to provide a thermal shock resistant coating forming die for an oxygen sensor, thereby overcoming the defects in the above-mentioned prior art.

[0006] To achieve the above-mentioned purpose, the utility model provides a forming mold for the heat-shock-resistant coating of an oxygen sensor, comprising an upper mold plate and a lower mold plate; a positioning groove and a grouting groove are arranged in the lower mold plate, the depth of the grouting groove is greater than the depth of the positioning groove, the grouting groove is connected to the positioning groove, the grouting groove and the positioning groove structure are matched with the oxygen sensor core structure, air passages connected to the outside are symmetrically arranged on both sides of the grouting groove, and an injection groove connected to the outside is arranged at the front end of the grouting groove; the upper mold plate is symmetrical with the lower mold plate, and the upper mold plate and the lower mold plate are detachably spliced ​​and connected, the positioning grooves of the upper mold plate and the lower mold plate are spliced ​​to form a positioning cavity, the grouting grooves are spliced ​​to form a forming cavity, the injection grooves are spliced ​​to form an injection port, and the air passages are spliced ​​to form an exhaust hole, the size of the forming cavity is larger than the size of the part of the oxygen sensor core to be coated, the gap between the inner wall of the forming cavity and the part to be coated is uniform, a regular coating is formed at the part to be coated during injection molding, and the gas formed in the drying process is discharged in time through the exhaust hole.

[0007] Preferably, in the technical solution, auxiliary exhaust holes communicating with the outside are evenly arranged at the bottom of the grouting groove in the upper template to improve the exhaust effect.

[0008] Preferably, in the technical solution, the diameters of the air ducts on both sides of the grouting groove are different, and the diameter of the air duct on one side is larger than the diameter of the air duct on the other side.

[0009] Preferably, in the technical solution, the upper template is provided with positioning pins at the four corners, and the lower template is provided with positioning grooves at corresponding positions, and the upper template and the lower template are connected and assembled through the positioning pins and the positioning grooves.

[0010] Preferably, in the technical solution, the upper template and the lower template are both made of polytetrafluoroethylene.

[0011] Preferably, in the technical solution, the inner wall surfaces of the grouting grooves of the upper template and the lower template are coated with silicone oil to facilitate separation of the coated oxygen sensor chip core from the mold.

[0012] Compared with the prior art, the utility model has the following beneficial effects:

[0013] The regular molding cavity can form a regular coating on the part of the oxygen sensor chip that needs to be coated. The coating production is efficient and convenient. The exhaust hole will discharge the gas formed during the drying process in time to ensure that the surface of the thermal shock resistant coating is smooth and free of bubbles. The upper and lower templates are connected by simple splicing, which is convenient for disassembly and assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the structure of the thermal shock resistant coating forming die of the oxygen sensor of the utility model;

[0015] Figure 2 This is a schematic diagram of the upper template structure of the utility model;

[0016] Figure 3 This is the front view of the upper template of the utility model;

[0017] Figure 4 It is a schematic diagram of the lower template structure of the utility model. DETAILED DESCRIPTION

[0018] The specific implementation modes of the present invention are described in detail below, but it should be understood that the protection scope of the present invention is not limited by the specific implementation modes.

[0019] Unless explicitly stated otherwise, throughout the specification and claims, the term “comprise” or variations such as “include” or “comprising”, etc., will be understood to include the stated elements or components but not to exclude other elements or components.

[0020] like Figure 1-4As shown, a heat shock resistant coating forming die for an oxygen sensor comprises an upper die plate 1 and a lower die plate 2, both of which are made of polytetrafluoroethylene; an upper positioning groove 10 and an upper grouting groove 11 are arranged in the upper die plate 1, the depth of the upper grouting groove 11 is greater than the depth of the upper positioning groove 10, the upper grouting groove 11 is connected to the upper positioning groove 10, the structures of the upper grouting groove 11 and the upper positioning groove 10 are matched with the structure of the oxygen sensor chip 3, and the upper grouting groove 11 is symmetrically arranged on both sides with the outer The upper air duct 12 is connected to the upper part, the diameter of the upper air duct 12 on one side is larger than the diameter of the upper air duct 12 on the other side, the front end of the upper grouting groove 11 is provided with an upper injection groove 13 connected to the outside, and the bottom of the upper grouting groove 11 is evenly provided with auxiliary exhaust holes 14 connected to the outside; the lower template 2 is provided with a lower positioning groove 20 and a lower grouting groove 21, the depth of the lower grouting groove 21 is greater than the depth of the lower positioning groove 20, the lower grouting groove 21 is connected to the lower positioning groove 20, the lower grouting groove 21, the lower positioning groove The structure 20 cooperates with the structure of the oxygen sensor core 3. The lower air ducts 22 connected to the outside are symmetrically arranged on both sides of the lower grouting groove 21. The diameter of the lower air duct 22 on one side is larger than the diameter of the lower air duct 22 on the other side. The front end of the lower grouting groove 21 is provided with a lower injection groove 23 connected to the outside; the upper template 1 is symmetrical with the lower template 2. The upper template 1 is provided with positioning pins 15 at four corners, and the lower template 2 is provided with positioning grooves 24 at corresponding positions. The upper template 1 and the lower template 2 are connected and assembled with the positioning grooves 24 through the positioning pins 15. The upper positioning grooves 10 and the lower positioning grooves 20 of the upper template 1 and the lower template 2 are assembled to form a positioning cavity, the upper grouting grooves 11 and the lower grouting grooves 21 are assembled to form a molding cavity, the upper injection grooves 13 and the lower injection grooves 23 are assembled to form an injection port, the upper air duct 12 and the lower air duct 22 are assembled to form an exhaust hole 4, the size of the molding cavity is larger than the size of the portion to be coated on the oxygen sensor core 3, and the gap between the inner wall of the molding cavity and the portion to be coated is uniform.

[0021] In the coating forming process, the exhaust holes 4 and the auxiliary exhaust holes 14 are blocked with matching row pins, silicone oil is applied to the inner wall surfaces of the upper grouting groove 11 and the lower grouting groove 21 and the top of the row pins, the oxygen sensor chip 3 is placed in the lower positioning groove 20 of the lower template 2, the coating portion is placed in the lower grouting groove 21, the upper template 1 is covered on the lower template 2 for assembly, the heat shock resistant coating slurry is injected into the molding cavity through the injection port, the slurry in the molding cavity covers the coating portion, and then the molding mold is placed in a 50°C oven for 30 minutes, the slurry forms a regular coating on the coating portion, the tooling is taken out, the row pins are removed, the exhaust holes 4 and the auxiliary exhaust holes 14 are leaked, and then the molding mold is placed in the oven for drying for 3 hours, the exhaust holes 4 on the side with a smaller diameter face the hot air blowing position, the hot air is blown in from the exhaust holes 4 on the side with a smaller diameter, and blown out from the exhaust holes 4 on the side with a larger diameter, so as to achieve an inlet and outlet air balance and achieve a better drying effect. The gas formed during the drying process is discharged in time to ensure that the surface of the thermal shock resistant coating is smooth and free of bubbles. The molding die is taken out and naturally cooled to room temperature, and the oxygen sensor chip 3 is taken out of the molding die to complete the molding of the thermal shock resistant coating.

[0022] The foregoing description of specific exemplary embodiments of the utility model is for the purpose of illustration and illustration. These descriptions are not intended to limit the utility model to the precise form disclosed, and it is clear that many changes and variations can be made based on the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the utility model and its practical application, so that those skilled in the art can realize and utilize various different exemplary embodiments of the utility model and various different options and changes. The scope of the utility model is intended to be defined by the claims and their equivalents.

Claims

1. A thermal shock resistant coating forming die for an oxygen sensor, characterized in that: It comprises an upper template and a lower template; the lower template is provided with a positioning groove and a grouting groove, the depth of the grouting groove is greater than the depth of the positioning groove, the grouting groove is connected to the positioning groove, the grouting groove and the positioning groove structure are matched with the oxygen sensor core structure, air passages connected to the outside are symmetrically provided on both sides of the grouting groove, and an injection groove connected to the outside is provided at the front end of the grouting groove; the upper template is symmetrical with the lower template, and the upper template and the lower template are detachably spliced ​​and connected, the positioning grooves of the upper template and the lower template are spliced ​​to form a positioning cavity, the grouting grooves are spliced ​​to form a molding cavity, the injection grooves are spliced ​​to form an injection port, and the air passages are spliced ​​to form an exhaust hole, the size of the molding cavity is greater than the size of the part of the oxygen sensor core to be coated, and the gap between the inner wall of the molding cavity and the part to be coated is uniform.

2. The oxygen sensor thermal shock resistant coating forming die according to claim 1, characterized in that: Auxiliary exhaust holes communicating with the outside are evenly arranged at the bottom of the grouting groove in the upper template.

3. The oxygen sensor thermal shock resistant coating forming die according to claim 1, characterized in that: The diameters of the air ducts on both sides of the grouting groove are different, and the diameter of the air duct on one side is larger than that of the air duct on the other side.

4. The oxygen sensor thermal shock resistant coating forming die according to claim 1, characterized in that: The upper template is provided with positioning pins at four corners, and the lower template is provided with positioning grooves at corresponding positions. The upper template and the lower template are connected and assembled through the positioning pins and the positioning grooves.

5. The oxygen sensor thermal shock resistant coating forming die according to claim 1, characterized in that: The upper mold plate and the lower mold plate are both made of polytetrafluoroethylene.

6. The oxygen sensor thermal shock resistant coating forming die according to claim 1, characterized in that: The inner wall surfaces of the grouting grooves of the upper template and the lower template are coated with silicone oil.

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