Ternary packaging assembly anti-corrosion structure

Abstract

The invention discloses an anti-corrosion structure of a ternary packaging assembly, and belongs to the technical field of automobile exhaust systems. An air inlet flange is connected with an air inlet upper shell, the air inlet upper shell and a lower shell form a cavity, a TWC carrier is fixed in the cavity through a first gasket, the air inlet lower shell is connected with a catalytic converter shell through a front end cone, a GPF carrier in the catalytic converter shell is fixed through a second gasket, the catalytic converter shell is connected with an exhaust pipe through a rear end cone, and the exhaust pipe is connected with a rear flange assembly. The oxygen sensor nut and the differential pressure pipe nut seat are respectively fixed on the outer wall of the corresponding shell, the differential pressure pipe assembly is correspondingly installed, the EGR pipe is connected with the catalytic converter shell and the heat insulation cover and is installed outside the catalytic converter shell through welding, the support is fixed through the bolt, and the relevant support, the heat insulation cotton and the like are correspondingly fixed. Through cooperation of material selection, process optimization and structural design, the anti-corrosion performance is improved, the service life is prolonged, and meanwhile the stability of the exhaust purification function and the environmental adaptability of the structure are guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of automobile exhaust systems, and in particular relates to a ternary package assembly anti-corrosion structure. Background Art

[0002] Currently, stainless steel exhaust manifold assemblies are widely used in automotive exhaust systems. During use, they are subject to corrosion from complex environmental factors such as humidity, salt spray, and acidic and alkaline substances. Poor corrosion resistance can seriously affect their mechanical properties, shorten their service life, and even pose safety risks. This solution aims to significantly enhance the corrosion resistance of the ternary package assembly through the integrated application of multiple corrosion protection technologies, enabling stable operation in complex environments and extending its service life beyond industry standards. Summary of the Invention

[0003] In order to solve the problems existing in the background technology, the present invention provides a ternary packaging assembly anti-corrosion structure.

[0004] To achieve the above objectives, the present invention adopts the following technical solutions: a three-element package assembly anti-corrosion structure, including an intake flange, an intake upper shell, an oxygen sensor nut 1, an intake lower shell, an upper heat insulation cover, a lower heat insulation cover, a pressure differential tube assembly 1, a pressure differential tube assembly 2, a pressure differential tube nut seat 1, an EGR flange, an EGR pipe, a connecting sleeve, a temperature sensor positioning seat, an oxygen sensor nut 2, a rear end cone, a pressure differential tube nut seat 2, a rear flange assembly, a right bracket, a pressure differential tube bracket, a pressure differential tube bracket cover, a front end cone, upper heat insulation cotton, lower heat insulation cotton, a TWC carrier, a gasket 1, a catalyst housing, a GPF carrier, a gasket 2, a left connecting bracket, a right connecting bracket, flange face bolts and an exhaust pipe; The intake flange is connected and fixed to the intake upper shell, the intake upper shell is fixedly connected to the intake lower shell and forms a cavity for accommodating the TWC carrier, the TWC carrier is fixed in the cavity by a gasket 1, the intake lower shell is connected and fixed to the front end cone, the front end cone is connected and fixed to the catalyst housing, a GPF carrier is provided in the catalyst housing, the GPF carrier is fixed in the catalyst housing by a gasket 2, the catalyst housing is connected and fixed to the rear end cone, the rear end cone is connected and fixed to the exhaust pipe, the exhaust pipe is connected and fixed to the rear flange assembly, the oxygen sensor nut 1 and the oxygen sensor nut 2 are respectively fixed on the outer walls of the intake upper shell and the catalyst housing, the temperature sensor positioning seat is fixed on the outer wall of the catalyst housing, the pressure differential tube nut seat 1 and the pressure differential tube nut seat 2 are respectively fixed on the outer wall of ... They are respectively fixed on the outer wall of the catalyst housing and the outer wall of the rear end cone, the pressure differential tube assembly 1 is fixed on the pressure differential tube nut seat 1, the pressure differential tube assembly 2 is fixed on the pressure differential tube nut seat 2, the EGR flange is connected and fixed to one end of the EGR pipe, and the other end of the EGR pipe is connected and fixed to the catalyst housing through a connecting sleeve, the upper heat insulation cover and the lower heat insulation cover are respectively fixed to the outer wall of the catalyst housing by resistance welding, the left connecting bracket and the right connecting bracket are fixedly connected to the catalyst housing by flange surface bolts, the pressure differential tube bracket is fixed on the outer wall of the catalyst housing, the pressure differential tube bracket cover is covered on the pressure differential tube bracket and fixedly connected, the right bracket is fixed to the exhaust pipe, the upper heat insulation cotton is fixed to the inner wall of the upper heat insulation cover, and the lower heat insulation cotton is fixed to the inner wall of the lower heat insulation cover.

[0005] The pressure differential pipe bracket cover plate is fixedly connected to the pressure differential pipe bracket by hexagonal flange bolts.

[0006] The materials of the intake flange, intake upper shell, intake lower shell, rear end cone, front end cone, catalyst housing, exhaust pipe, pressure differential pipe bracket, and pressure differential pipe bracket cover are all 441 ferritic stainless steel; The materials of the oxygen sensor nut 1, oxygen sensor nut 2, upper heat shield, lower heat shield, differential pressure tube assembly 1, differential pressure tube assembly 2, differential pressure tube nut seat 1, differential pressure tube nut seat 2, EGR flange, EGR pipe, connecting sleeve, temperature sensor positioning seat, rear flange assembly, right bracket, left connecting bracket, and right connecting bracket are all SUS304 austenitic stainless steel; The material of the hexagonal flange bolts and flange bolts is No. 35 steel.

[0007] All bolts are Dacromet-treated, and all exposed welds are painted with silver paint. Except for the intake flange, intake upper shell, intake lower shell, front end cone, catalyst housing, upper heat shield, lower heat shield, pressure differential tube assembly 1, and pressure differential tube assembly 2, the surfaces of all 441 and SUS304 parts are passivated before welding to meet the 720-hour red rust-free standard.

[0008] Compared with the prior art, the present invention has the following beneficial effects: 1. Significantly improved corrosion resistance and extended assembly service life: A layered corrosion protection design is employed. Core components (such as the intake flange and catalyst housing) are constructed from 441 ferritic stainless steel to withstand high-temperature exhaust gas corrosion. Sensor connectors, brackets, and other components are constructed from SUS304 austenitic stainless steel to withstand humid salt spray environments. Bolts are Dacromet-treated to enhance rust resistance. Furthermore, processes such as coating exposed welds with silver powder paint and passivating parts before welding achieve a 720-hour rust-free corrosion protection, effectively preventing structural damage caused by corrosion and extending the assembly service life.

[0009] 2. Ensure the stability of the exhaust purification function: Structurally, a closed cavity is formed by the intake upper shell and the intake lower shell. The TWC carrier is fixed with gasket 1, and the GPF carrier is fixed to the catalyst housing through gasket 2, ensuring the installation stability of the catalytic purification and particulate matter filtering components. The sealed connection design of the intake and exhaust paths (such as the front cone fixed to the catalyst housing and the rear cone fixed to the exhaust pipe) prevents exhaust gas leakage, which not only ensures purification efficiency but also reduces the corrosive effects of leaked exhaust gas on surrounding components.

[0010] 3. Enhanced structural reliability and environmental adaptability: The upper and lower heat shields are fixed to the outer wall of the catalyst housing by resistance welding. Combined with internal insulation cotton, they reduce the heat radiation of high-temperature exhaust gas and the accelerated effect of temperature changes on material corrosion. The various components are connected using bolts (such as hexagonal flange bolts and flange bolts). The anti-corrosion treatment of the connection parts is combined with the structural design to enable the assembly to adapt to complex operating conditions such as vibration and temperature differences during vehicle operation, thereby improving overall operational reliability.

[0011] In summary, the ternary packaging assembly anti-corrosion structure improves the anti-corrosion performance and extends the service life through the coordination of material selection, process optimization and structural design, while ensuring the stability of the exhaust purification function and the environmental adaptability of the structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a front view of the present invention; Figure 2 It is a left side view of the present invention; Figure 3 It is a schematic diagram of the internal structure of the present invention. DETAILED DESCRIPTION

[0013] The technical solutions of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0014] This embodiment describes a three-component package assembly anti-corrosion structure, including an intake flange 1, an intake upper shell 2, an oxygen sensor nut 1 3, an intake lower shell 4, an upper heat shield 5, a lower heat shield 6, a pressure differential tube assembly 1 7, a pressure differential tube assembly 2 8, a pressure differential tube nut seat 1 9, an EGR flange 10, an EGR tube 11, a connecting sleeve 12, a temperature sensor positioning seat 13, an oxygen sensor nut 2 14, a rear end cone 15, a pressure differential tube nut seat 2 16, a rear flange assembly 17, a right bracket 18, a pressure differential tube bracket 19, a pressure differential tube bracket cover 20, a front end cone 22, upper heat insulation cotton 23, lower heat insulation cotton 24, a TWC substrate 25, a gasket 1 26, a catalyst housing 27, a GPF substrate 28, a gasket 29, a left connecting bracket 30, a right connecting bracket 31, flange face bolts 32, and an exhaust pipe 33. The intake flange 1 is connected and fixed to the intake upper shell 2, and the intake upper shell 2 is fixedly connected to the intake lower shell 4 to form a cavity for accommodating the TWC carrier 25. The TWC carrier 25 is fixed in the cavity by a gasket 1 26. The intake lower shell 4 is connected and fixed to the front end cone 22, and the front end cone 22 is connected and fixed to the catalyst housing 27. A GPF carrier 28 is provided in the catalyst housing 27, and the GPF carrier 28 is fixed in the catalyst housing 27 by a gasket 29. The catalyst housing 27 is connected and fixed to the rear end cone 15, and the rear end cone 15 is connected and fixed to the exhaust pipe 33, and the exhaust pipe 33 is connected and fixed to the rear flange assembly 17. The oxygen sensor nut 1 3 and the oxygen sensor nut 2 14 are respectively fixed on the outer walls of the intake upper shell 2 and the catalyst housing 27, the temperature sensor positioning seat 13 is fixed on the outer wall of the catalyst housing 27, the pressure differential pipe nut seat 1 9 and the pressure differential pipe nut seat 2 1 6 are respectively fixed on the outer wall of the catalyst housing 27 and the outer wall of the rear end cone 15, the pressure differential pipe assembly 17 is fixed on the pressure differential pipe nut seat 19, the pressure differential pipe assembly 28 is fixed on the pressure differential pipe nut seat 216, the EGR flange 10 is connected and fixed to one end of the EGR pipe 11, and the other end of the EGR pipe 11 is connected and fixed to the catalyst housing 27 through the connecting sleeve 12, the upper heat insulation cover 5 and the lower heat insulation cover 6 are respectively fixed to the outer wall of the catalyst housing 27 by resistance welding, the left connecting bracket 30 and the right connecting bracket 31 are fixedly connected to the catalyst housing 27 by flange face bolts 32, the pressure differential pipe bracket 19 is fixed on the outer wall of the catalyst housing 27, the pressure differential pipe bracket cover 20 covers the pressure differential pipe bracket 19 and is fixedly connected, the right bracket 18 is fixed to the exhaust pipe 33, the upper insulation cotton 23 is fixed to the inner wall of the upper insulation cover 5, and the lower insulation cotton 24 is fixed to the inner wall of the lower insulation cover 6.

[0015] The pressure differential pipe bracket cover plate 20 is fixedly connected to the pressure differential pipe bracket 19 by hexagonal flange bolts 21 .

[0016] The materials of the intake flange 1, intake upper shell 2, intake lower shell 4, rear end cone 15, front end cone 22, catalyst housing 27, exhaust pipe 33, pressure differential pipe bracket 19, and pressure differential pipe bracket cover 20 are all 441 ferritic stainless steel; The materials of the oxygen sensor nut 1 3, oxygen sensor nut 2 14, upper heat shield 5, lower heat shield 6, differential pressure tube assembly 1 7, differential pressure tube assembly 2 8, differential pressure tube nut seat 1 9, differential pressure tube nut seat 2 16, EGR flange 10, EGR pipe 11, connecting sleeve 12, temperature sensor positioning seat 13, rear flange assembly 17, right bracket 18, left connecting bracket 30, and right connecting bracket 31 are all SUS304 austenitic stainless steel; The material of the hexagonal flange bolts 21 and flange bolts 32 is 35# steel. (The high temperature corrosion resistance of 441 ferritic stainless steel meets the following requirements: under the condition of long-term use at 800℃, it can withstand SO2 and NO in exhaust gas. X Erosion, corrosion rate ≤ 0.01mm / year); SUS304 austenitic stainless steel, neutral salt spray resistance ≥ 1000h (according to GB / T 10125 standard); 35# steel after Dacromet treatment, coating thickness controlled at 8-12μm, neutral salt spray resistance ≥ 500h) All bolts are Dacromet treated (Dacromet treatment: after degreasing and rust removal, the bolts are immersed in Dacromet solution, coating thickness 8-12μm, cured at 300±10℃ for 30min; exposed welds are painted with high-temperature silver paint, welding slag must be cleaned before painting, dry film thickness ≥ 30μm, and naturally dried for 24h; passivation treatment uses chromium-free passivation solution (concentration 5%-8%), immersion time 10-15min, forming a passivation film thickness of 0.5-1μm, drying temperature 80℃), all exposed welds are painted with silver paint, except for intake flange 1, intake upper shell 2, intake lower shell 4, front Except for the end cone 22, catalyst housing 27, upper heat shield 5, lower heat shield 6, differential pressure tube assembly 1 7, and differential pressure tube assembly 2 8, the surfaces of all parts made of 441 and SUS304 materials are passivated (the components are passivated after welding the bracket and projection welding nut. The passivated parts are laser welded (welding temperature ≤ 1200°C). After welding, the weld and heat-affected zone (range: within 5mm of the weld edge) are locally re-coated with passivation liquid; exposed welds are defined as 'welds directly in contact with the external environment' (such as the connection weld between the intake flange and the intake upper shell, and the weld between the exhaust pipe and the rear flange assembly). Non-exposed welds (such as the welds in the shell cavity) do not need to be coated with silver powder paint) before welding, and they must meet the 720-hour red rust-free standard. ('720h No Red Rust' is based on a neutral salt spray test (per GB / T 10125-2021). Test conditions: temperature 35±2°C, salt spray concentration 5% (NaCl solution), pH 6.5-7.2. After 720 hours of continuous exposure, no red rust is observed on the surface (rust area ≤ 0.1%).) When the present ternary package assembly anti-corrosion structure is working, the high-temperature exhaust gas discharged by the engine first enters the cavity formed by the fixed connection between the intake upper shell 2 and the intake lower shell 4 through the intake flange 1. The TWC carrier 25 fixed by the gasket 1 26 in the cavity will perform preliminary catalytic purification on the exhaust gas to remove pollutants such as carbon monoxide and hydrocarbons; the purified exhaust gas enters the front cone 22 through the intake lower shell 4, and then flows into the catalyst housing 27. The GPF carrier 28 fixed by the gasket 29 in the catalyst housing will filter the particulate matter in the exhaust gas, and then the filtered exhaust gas enters through the rear cone 15 The exhaust pipe 33 (gasket 1 26 and gasket 2 29 are made of ceramic fiber reinforced metal mesh, with a temperature resistance of ≥1000°C and a compression rate of 15%-20% to ensure sealing while avoiding damage to the carrier under pressure) is finally discharged through the rear flange assembly 17. During the entire process of exhaust gas circulation, the upper heat insulation cover 5 and the lower heat insulation cover 6 are fixed to the outer wall of the catalyst housing by resistance welding. The upper heat insulation cotton 23 and the lower heat insulation cotton 24 inside can effectively reduce the heat radiation of high-temperature exhaust gas to surrounding components and reduce the material corrosion rate caused by temperature changes. At the same time, the corrosion resistance of the structure is improved by the material. The selection and process treatment are jointly guaranteed. The intake flange 1, catalyst housing 27 and other components that are in direct contact with high-temperature exhaust gas are made of 441 material. This material has good high-temperature corrosion resistance and can resist the erosion of acidic substances in the exhaust gas. The oxygen sensor nut 3, EGR pipe 11 and other components are made of SUS304 material, which can adapt to external environments such as moisture and salt spray. The hexagonal flange bolts 21, flange bolts 32 and other connectors are made of 35 steel, which is treated with Dacromet to form a protective film to enhance corrosion resistance. In addition, all exposed welds are painted with silver powder paint to seal the gaps and avoid electrochemical corrosion. Except for specific core components, 441 and SUS304 material parts are passivated before welding, and the bracket and projection welding nut are passivated after welding to form an oxide protective film to ensure that the 720h red rust-free requirement is met. In addition, the differential pressure tube assembly 1 7 and the differential pressure tube assembly 2 8 are fixed by the corresponding differential pressure tube nut seats, and the EGR pipe 11 is connected to the catalyst housing 27 through the connecting sleeve 12. These auxiliary components are made of suitable materials and cooperate with the overall anti-corrosion process, which further guarantees the anti-corrosion effect of the entire assembly, ensures the stable operation of the structure in complex environments, and extends the service life.

[0017] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

Claims

1. A ternary package assembly anti-corrosion structure, characterized by: It includes an intake flange (1), an intake upper shell (2), an oxygen sensor nut (3), an intake lower shell (4), an upper heat insulation cover (5), a lower heat insulation cover (6), a pressure differential tube assembly (7), a pressure differential tube assembly (8), a pressure differential tube nut seat (9), an EGR flange (10), an EGR tube (11), a connecting sleeve (12), a temperature sensor positioning seat (13), an oxygen sensor nut (14), a rear end cone (15), a pressure differential tube nut seat (16), a rear flange assembly (17), a right bracket (18), a pressure differential tube bracket (19), a pressure differential tube bracket cover (20), a front end cone (22), an upper heat insulation cotton (23), a lower heat insulation cotton (24), a TWC carrier (25), a gasket (26), a catalyst housing (27), a GPF carrier (28), a gasket (29), a left connecting bracket (30), a right connecting bracket (31), flange face bolts (32) and an exhaust pipe (33); The intake flange (1) is connected and fixed to the intake upper shell (2), the intake upper shell (2) is fixedly connected to the intake lower shell (4) to form a cavity for accommodating a TWC carrier (25), the TWC carrier (25) is fixed in the cavity via a gasket 1 (26), the intake lower shell (4) is connected and fixed to the front end cone (22), the front end cone (22) is connected and fixed to the catalyst housing (27), a GPF carrier (28) is provided in the catalyst housing (27), and the GPF carrier (28) is fixed in the cavity via a gasket 2 (29). Inside the catalyst housing (27), the catalyst housing (27) is connected and fixed to the rear end cone (15), the rear end cone (15) is connected and fixed to the exhaust pipe (33), the exhaust pipe (33) is connected and fixed to the rear flange assembly (17), the oxygen sensor nut 1 (3) and the oxygen sensor nut 2 (14) are respectively fixed to the outer wall of the intake upper shell (2) and the catalyst housing (27), the temperature sensor positioning seat (13) is fixed to the outer wall of the catalyst housing (27), the pressure differential tube nut seat 1 (9) and the pressure differential tube nut seat 2 ( 16) are fixed on the outer wall of the catalyst housing (27) and the outer wall of the rear end cone (15), respectively, the pressure differential tube assembly (7) is fixed on the pressure differential tube nut seat (9), the pressure differential tube assembly (8) is fixed on the pressure differential tube nut seat (16), the EGR flange (10) is connected and fixed to one end of the EGR pipe (11), the other end of the EGR pipe (11) is connected and fixed to the catalyst housing (27) through the connecting sleeve (12), the upper heat shield (5) and the lower heat shield (6) are fixed to the catalyst housing (27) by resistance welding, respectively. The outer wall of the catalyst housing (27), the left connecting bracket (30) and the right connecting bracket (31) are fixedly connected to the catalyst housing (27) by flange bolts (32), the pressure differential pipe bracket (19) is fixed to the outer wall of the catalyst housing (27), the pressure differential pipe bracket cover (20) covers the pressure differential pipe bracket (19) and is fixedly connected, the right bracket (18) is fixed to the exhaust pipe (33), the upper heat insulation cotton (23) is fixed to the inner wall of the upper heat insulation cover (5), and the lower heat insulation cotton (24) is fixed to the inner wall of the lower heat insulation cover (6).

2. The ternary packaging assembly anti-corrosion structure according to claim 1, characterized in that: The pressure differential pipe bracket cover plate (20) is fixedly connected to the pressure differential pipe bracket (19) via hexagonal flange bolts (21).

3. The ternary package assembly anti-corrosion structure according to claim 1, characterized in that: The materials of the intake flange (1), the intake upper shell (2), the intake lower shell (4), the rear end cone (15), the front end cone (22), the catalyst housing (27), the exhaust pipe (33), the pressure differential tube bracket (19), and the pressure differential tube bracket cover (20) are all 441 ferritic stainless steel. The materials of the oxygen sensor nut one (3), the oxygen sensor nut two (14), the upper heat shield (5), the lower heat shield (6), the pressure differential tube assembly one (7), the pressure differential tube assembly two (8), the pressure differential tube nut seat one (9), the pressure differential tube nut seat two (16), the EGR flange (10), the EGR tube (11), the connecting sleeve (12), the temperature sensor positioning seat (13), the rear flange assembly (17), the right bracket (18), the left connecting bracket (30), and the right connecting bracket (31) are all SUS304 austenitic stainless steel. The materials of the hexagonal flange face bolts (21) and the flange face bolts (32) are No. 35 steel.

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