General exhaust aftertreatment heat shield

Abstract

The invention belongs to the technical field of automobile exhaust aftertreatment package structures, and discloses a general exhaust aftertreatment heat shield. The general exhaust aftertreatment heat shield comprises heat insulating sheets with the semi-circular section, landing edges are arranged on one sides of the heat insulating sheets, and the two heat insulating sheets are buckled throughthe landing edges to form the cylindrical heat shield; and inclined corners are arranged at one ends of the heat insulating sheets, reinforcing bars are arranged on the outer surfaces of the heat insulating sheets, heat insulating cotton and reinforcing supports are arranged on the inner surfaces of the heat insulating sheets at intervals, and the reinforcing supports are arranged in the circumferential direction of the heat insulating sheets. The cost of an aftertreatment mold is greatly lowered; the process requirements of aftertreatment assembly production are met, welding is easy, and theproduction efficiency is improved; the loading reliability requirements when a hoop is fixed to the heat shield are met; and the overall heat preservation effect of aftertreatment is achieved, and theheat-insulating protection effect is achieved on parts surrounding aftertreatment.

Description

technical field [0001] The invention belongs to the technical field of packaging structure for after-treatment of automobile exhaust, and in particular relates to a general-purpose heat shield for after-treatment of exhaust. Background technique [0002] The chemical reaction of the engine exhaust processor has a lot to do with the heat change. In the National IV and National V stages, there are more SCR (Selective Catalytic Reduction Technology) product urea crystallization and blockage at low temperature. At the National VI stage, providing some heat sources required for SCR low-temperature catalysis and DPF (diesel particulate filter) regeneration under low-speed conditions has become the key to the National VI emission control technology. Keeping the exhaust temperature up to the standard after the engine is on the car has become one of the important performance indicators of the National VI after-treatment package structure. Therefore, based on the need for thermal man...

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Problems solved by technology

One is to wrap flexible thermal insulation cotton made of fiber material on the post-processing packaging structure. Due to the use of DPF in the National VI stage, the disassembly device has become a must-have structure for packaging. The post-processing will be segmented accordingly, and the heat insulation devices will also increase. A set of DOC (Oxidation Catalyst), DPF, and SCR post-treatment generally requires four sections of cotton-wrapped heat shields or 6 to 8 pieces of cotton-coated heat shields. The number of heat shield parts used increases, directly As a result, the mold development of post-processing assembly parts increased, and the cost increased. At the same time, the appearance of the insulation cotton wrapped on the post-processing packaging structure was poor, and the deformation amount was uncontrollable when the hoop was tightened.

The second is to use a double-layer structure to post-process the packaged products. The structure is relatively complicated. It is necessary to design a two-layer cylinder or box, and to design a special partition support structure. There are many production processes and high manufacturing costs.

The third is to weld or install cotton-coated metal heat shields outside the post-processing packaging products. This is the heat insulation method that everyone is focusing on developing. There are two main options. The first is a single-piece stamping structure, and its technological characteristics are for each piece Open a set of molds. This kind of heat shield has better contour control, higher strength, and easy assembly production. The disadvantage is that the cost of single-piece mold opening is extremely high. Usually, each post-processing requires 6 to 8 heat shields, resulting in The overall cost of aftertreatment products has risen significantly

The second way is to set a support ring on the cylinder, fill it with insulation material and then set a layer of cylinder outside the support ring. This structure takes a lot of time in actual production and the manufacturing cost is relatively high.

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