A kind of anticorrosive structure of ternary package assembly

Abstract

A kind of ternary encapsulation assembly anticorrosion structure belongs to the technical field of automobile exhaust system. Intake flange is connected with intake upper shell, intake upper shell and lower shell form cavity, TWC carrier is fixed in it by gasket one, intake lower shell is connected with catalytic converter shell through front end taper, GPF carrier in it is fixed by gasket two, catalytic converter shell is connected with exhaust pipe through rear end taper, exhaust pipe is connected with rear flange assembly, oxygen sensor nut and differential pressure tube nut seat are fixed on corresponding shell outer wall respectively, differential pressure tube assembly is installed correspondingly, EGR pipe is connected with catalytic converter shell, heat shield is welded on catalytic converter shell outside, bracket is fixed by bolt, relevant bracket, heat insulation cotton and the like are fixed correspondingly. The utility model improves anticorrosion performance, prolongs service life while guaranteeing the stability of exhaust purification function and the environmental adaptability of structure by the synergy of material selection, process optimization and structure design.

Description

Technical Field

[0001] This utility model belongs to the field of automotive exhaust system technology, specifically a corrosion-resistant structure for a ternary encapsulation assembly. Background Technology

[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 / alkaline substances. Poor corrosion resistance can severely affect their mechanical properties, shorten their service life, and even pose safety hazards. This solution aims to significantly improve the corrosion resistance of ternary catalytic converter assemblies through the comprehensive application of multiple anti-corrosion technologies, enabling them to operate stably in complex environments and exceeding industry standards for service life. Summary of the Invention

[0003] To address the problems existing in the background technology, this utility model provides a corrosion-resistant structure for a ternary packaging assembly.

[0004] To achieve the above objectives, this utility model adopts the following technical solution: a ternary encapsulation assembly anti-corrosion structure, including an intake flange, an upper intake shell, an oxygen sensor nut, a lower intake shell, an upper heat shield, a lower heat shield, a differential pressure tube assembly, a second differential pressure tube assembly, a first differential pressure tube nut seat, an EGR flange, an EGR tube, a connecting sleeve, a temperature sensor positioning seat, a second oxygen sensor nut, a rear cone, a second differential pressure tube nut seat, a rear flange assembly, a right bracket, a differential pressure tube bracket, a differential pressure tube bracket cover plate, a front cone, upper heat insulation cotton, lower heat insulation cotton, a TWC carrier, a first gasket, a catalyst housing, a GPF carrier, a second gasket, a left connecting bracket, a right connecting bracket, flange bolts, and an exhaust pipe;

[0005] The intake flange is fixedly connected to the upper intake shell. The upper intake shell is fixedly connected to the lower intake shell to form a cavity for accommodating the TWC carrier. The TWC carrier is fixed in the cavity by a gasket. The lower intake shell is fixedly connected to the front cone. The front cone is fixedly connected to the catalytic converter housing. A GPF carrier is disposed inside the catalytic converter housing. The GPF carrier is fixed inside the catalytic converter housing by a gasket. The catalytic converter housing is fixedly connected to the rear cone. The rear cone is fixedly connected to the exhaust pipe. The exhaust pipe is fixedly connected to the rear flange assembly. Oxygen sensor nut one and oxygen sensor nut two are respectively fixed to the outer walls of the upper intake shell and the catalytic converter housing. The temperature sensor positioning seat is fixed to the outer wall of the catalytic converter housing. Differential pressure pipe nut seat one and differential pressure pipe nut seat two are... The differential pressure pipe assembly is fixed to the outer wall of the catalytic converter housing and the outer wall of the rear cone. The first differential pressure pipe assembly is fixed to the first differential pressure pipe nut seat, and the second differential pressure pipe assembly is fixed to the second differential pressure pipe nut seat. 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 catalytic converter housing through a connecting sleeve. The upper heat shield and the lower heat shield are fixed to the outer wall of the catalytic converter housing by resistance welding. The left connecting bracket and the right connecting bracket are fixed to the catalytic converter housing by flange bolts. The differential pressure pipe bracket is fixed to the outer wall of the catalytic converter housing. The differential pressure pipe bracket cover plate is covered and fixedly connected to the differential pressure pipe bracket. 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 shield, and the lower heat insulation cotton is fixed to the inner wall of the lower heat insulation shield.

[0006] The differential pressure pipe support cover plate and the differential pressure pipe support are fixedly connected by hexagonal flange bolts.

[0007] The materials of the intake flange, upper intake shell, lower intake shell, rear cone, front cone, catalytic converter shell, exhaust pipe, differential pressure pipe bracket, and differential pressure pipe bracket cover are all 441 ferritic stainless steel.

[0008] The materials of the oxygen sensor nut 1, oxygen sensor nut 2, upper heat insulation cover, lower heat insulation cover, 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 tube, connecting sleeve, temperature sensor positioning seat, rear flange assembly, right bracket, left connecting bracket, and right connecting bracket are all SUS304 austenitic stainless steel.

[0009] The material of the hexagonal flange bolts and flange bolts is No. 35 steel.

[0010] Compared with the prior art, the beneficial effects of this utility model are:

[0011] 1. Significantly enhances corrosion resistance and extends assembly service life: Adopting a layered anti-corrosion design, core components (intake flange, catalytic converter housing, etc.) are made of 441 ferritic stainless steel to withstand high-temperature exhaust gas corrosion, while sensor connectors, brackets, and other components are made of SUS304 austenitic stainless steel to resist humid salt spray environments. Bolts are treated with Dacromet to enhance their rust resistance. At the same time, through processes such as applying silver paint to exposed welds and welding after passivation treatment of parts, a 720-hour rust-free anti-corrosion effect is achieved, effectively avoiding structural damage caused by corrosion and extending the service life of the assembly.

[0012] 2. Ensuring the stability of exhaust purification function: Structurally, the upper and lower intake shells form a closed cavity, which is used to fix the TWC carrier with gasket one. The catalytic converter shell is fixed with the GPF carrier through gasket two, ensuring the installation stability of the catalytic purification and particulate matter filter components. The sealed connection design of the intake and exhaust paths (such as fixing the front cone to the catalytic converter shell and the rear cone to the exhaust pipe) avoids exhaust gas leakage, which not only ensures purification efficiency but also reduces the corrosive impact of leaked exhaust gas on surrounding components.

[0013] 3. Enhance structural reliability and environmental adaptability: The upper and lower heat insulation covers are fixed to the outer wall of the catalyst housing by resistance welding. Combined with internal heat insulation cotton, the heat radiation of high-temperature exhaust gas is reduced, thus reducing the accelerating effect of temperature changes on material corrosion. All components are fastened with bolts (such as hexagonal flange bolts and flange bolts). The anti-corrosion treatment of the connection parts is combined with the structural design, enabling the assembly to adapt to complex operating conditions such as vibration and temperature difference during vehicle operation, thereby improving overall operational reliability.

[0014] In summary, the corrosion-resistant structure of this ternary encapsulation assembly, through the synergy of material selection, process optimization, and structural design, not only improves corrosion resistance and extends service life, but also ensures the stability of exhaust purification function and the environmental adaptability of the structure. Attached Figure Description

[0015] Figure 1 This is a front view of the present invention;

[0016] Figure 2 This is a left view of the present invention;

[0017] Figure 3 This is a schematic diagram of the internal structure of this utility model. Detailed Implementation

[0018] The technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of this utility model. Obviously, the described embodiments are only some embodiments of the utility model, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the protection scope of this utility model.

[0019] This embodiment describes a corrosion-resistant structure for a ternary encapsulation assembly, including an intake flange 1, an upper intake shell 2, an oxygen sensor nut 1 3, an intake lower shell 4, an upper heat shield 5, a lower heat shield 6, a differential pressure tube assembly 1 7, a differential pressure tube assembly 2 8, a differential pressure 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 cone 15, a differential pressure tube nut seat 2 16, a rear flange assembly 17, a right bracket 18, a differential pressure tube bracket 19, a differential pressure tube bracket cover plate 20, a front cone 22, upper heat insulation cotton 23, lower heat insulation cotton 24, a TWC carrier 25, a gasket 1 26, a catalytic converter housing 27, a GPF carrier 28, a gasket 29, a left connecting bracket 30, a right connecting bracket 31, flange bolts 32, and an exhaust pipe 33.

[0020] The intake flange 1 is connected and fixed to the upper intake shell 2. The upper intake shell 2 is fixedly connected to the lower intake shell 4 to form a cavity for accommodating the TWC carrier 25. The TWC carrier 25 is fixed in the cavity by a gasket 26. The lower intake shell 4 is connected and fixed to the front cone 22. The front cone 22 is connected and fixed to the catalytic converter housing 27. A GPF carrier 28 is disposed inside the catalytic converter housing 27. The GPF carrier 28 is fixed inside the catalytic converter housing 27 by a gasket 29. The catalytic converter housing 27 is connected and fixed to the rear cone 15. The rear 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 14 and oxygen sensor nut 25 are fixed to the outer walls of the upper intake shell 2 and the catalytic converter housing 27, respectively. The temperature sensor positioning seat 13 is fixed to the outer wall of the catalytic converter housing 27. The differential pressure pipe nut seat 19 and differential pressure pipe nut seat 29 are also fixed to the outer walls of the catalytic converter housing 27. 6 are respectively fixed on the outer wall of the catalytic converter housing 27 and the outer wall of the rear cone 15. The differential pressure pipe assembly 7 is fixed on the differential pressure pipe nut seat 9. The differential pressure pipe assembly 8 is fixed on the differential pressure pipe 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 catalytic converter housing 27 through the connecting sleeve 12. The upper heat shield 5 and the lower heat shield 6 are respectively fixed to the outer wall of the catalytic converter housing 27 by resistance welding. The left connecting bracket 30 and the right connecting bracket 31 are fixedly connected to the catalytic converter housing 27 by flange bolts 32. The differential pressure pipe bracket 19 is fixed to the outer wall of the catalytic converter housing 27. The differential pressure pipe bracket cover plate 20 covers the differential pressure 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. The lower heat insulation cotton 24 is fixed to the inner wall of the lower heat insulation cover 6.

[0021] The differential pressure pipe support cover plate 20 and the differential pressure pipe support 19 are fixedly connected by hexagonal flange bolts 21.

[0022] The materials of the intake flange 1, intake upper shell 2, intake lower shell 4, rear cone 15, front cone 22, catalyst shell 27, exhaust pipe 33, differential pressure pipe bracket 19, and differential pressure pipe bracket cover plate 20 are all 441 ferritic stainless steel.

[0023] The materials of the oxygen sensor nut 13, oxygen sensor nut 24, upper heat insulation cover 5, lower heat insulation cover 6, differential pressure tube assembly 17, differential pressure tube assembly 28, differential pressure tube nut seat 19, differential pressure tube nut seat 216, EGR flange 10, EGR tube 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.

[0024] The hexagonal flange bolts 21 and 32 are made of No. 35 steel. (The high-temperature corrosion resistance of 441 ferritic stainless steel meets the following requirements: under long-term use at 800℃, it is resistant to SO2 and NO in exhaust gas.) x Corrosion, 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 treated with Dacromet (Dacromet treatment: bolts are degreased and derusted, then immersed in Dacromet solution, coating thickness 8-12μm, cured at 300±10℃ for 30min; exposed welds are coated with high-temperature silver paint, welding slag must be cleaned before coating, dry film thickness ≥30μm, 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 coated with silver paint, except for intake flange 1, intake upper shell 2, intake lower shell 4, and front Except for the end cone 22, catalyst housing 27, upper heat shield 5, lower heat shield 6, differential pressure pipe assembly 1 7, and differential pressure pipe assembly 2 8, all parts made of 441 and SUS304 materials are passivated (the components are passivated after the bracket and projection weld nut are welded, and the passivated parts are laser welded (welding temperature ≤1200℃). After welding, the weld and heat-affected zone (range: within 5mm of the weld edge) are locally coated with passivating liquid. Exposed welds are defined as 'welds that are in direct 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 weld inside the housing cavity) do not need to be coated with silver paint) before welding, to meet the requirement of no red rust for 720h. ('No red rust after 720h' is based on neutral salt spray test (according to GB / T 10125-2021 standard). Test conditions: temperature 35±2℃, salt spray concentration 5% (NaCl solution), pH value 6.5-7.2, after continuous exposure for 720h, no red rust on the surface (rust area ≤0.1%))

[0025] During operation, the high-temperature exhaust gas from the engine first enters the cavity formed by the fixed connection between the upper intake shell 2 and the lower intake shell 4 through the intake flange 1. Within the cavity, the TWC carrier 25, fixed by gasket 26, performs preliminary catalytic purification of the exhaust gas, removing pollutants such as carbon monoxide and hydrocarbons. The purified exhaust gas then enters the front cone 22 through the lower intake shell 4 and flows into the catalytic converter housing 27. Inside the catalytic converter housing, the GPF carrier 28, fixed by gasket 29, filters particulate matter in the exhaust gas. The filtered exhaust gas then enters the rear cone 15... The exhaust pipe 33 (with gaskets 26 and 29 made of ceramic fiber reinforced metal mesh, temperature resistant ≥1000℃, compression controlled at 15%-20% to ensure sealing while preventing damage to the carrier under pressure) finally discharges through the rear flange assembly 17. Throughout the exhaust gas flow process, the upper heat insulation cover 5 and 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 lower heat insulation cotton 24 inside effectively reduce the heat radiation of high-temperature exhaust gas to surrounding components, reducing the material corrosion rate caused by temperature changes. Simultaneously, the structure's corrosion resistance is enhanced by the materials... Selection and processing work together to ensure quality. Components that directly contact high-temperature exhaust gases, such as the intake flange 1 and catalytic converter housing 27, are made of 441 material, which has excellent high-temperature corrosion resistance and can resist the erosion of acidic substances in the exhaust gas. Components such as the oxygen sensor nut 3 and EGR pipe 11 are made of SUS304 material, which can adapt to external environments such as humidity and salt spray. Connecting parts such as hexagonal flange bolts 21 and flange bolts 32 are made of 35 steel, and a Dacromet coating is applied to form a protective film to enhance corrosion resistance. In addition, all exposed welds are coated with silver paint to seal gaps and prevent electrochemical corrosion. Except for specific core components, parts made of 441 and SUS304 materials are passivated before welding, and the components are passivated after welding of the bracket and projection weld nut, which can form an oxide protective film to ensure that the requirement of no red rust is met for 720 hours. In addition, differential pressure pipe assembly 1 7 and differential pressure pipe assembly 2 8 are fixed by corresponding differential pressure pipe nut seats, and EGR pipe 11 is connected to catalyst housing 27 through connecting sleeve 12. These auxiliary components are all made of suitable materials and are combined with the overall anti-corrosion process to further ensure the anti-corrosion effect of the entire assembly, ensure the stable operation of the structure in complex environments, and extend the service life.

[0026] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of the equivalents of the claims are intended to be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A corrosion-resistant structure for a ternary encapsulation assembly, characterized in that: Includes intake flange (1), upper intake shell (2), oxygen sensor nut one (3), lower intake shell (4), upper heat shield (5), lower heat shield (6), differential pressure tube assembly one (7), differential pressure tube assembly two (8), differential pressure tube nut seat one (9), EGR flange (10), EGR tube (11), connecting sleeve (12), temperature sensor positioning seat (13), oxygen sensor nut two (14), rear cone (15), differential pressure tube nut seat two (16), rear flange assembly (17), right bracket (18), differential pressure tube bracket (19), differential pressure tube bracket cover plate (20), front cone (22), upper heat insulation cotton (23), lower heat insulation cotton (24), TWC carrier (25), gasket one (26), catalyst housing (27), GPF carrier (28), gasket two (29), left connecting bracket (30), right connecting bracket (31), flange bolts (32), and exhaust pipe (33); The intake flange (1) is connected and fixed to the upper intake shell (2). The upper intake shell (2) is fixedly connected to the lower intake shell (4) to form a cavity for accommodating the TWC carrier (25). The TWC carrier (25) is fixed in the cavity by a gasket (26). The lower intake shell (4) is connected and fixed to the front cone (22). The front cone (22) is connected and fixed to the catalyst housing (27). A GPF carrier (28) is provided inside the catalyst housing (27). The GPF carrier (28) is fixed by a gasket (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 one (3) and oxygen sensor nut two (14) are respectively fixed to the outer walls 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), and the differential pressure pipe nut seat one (9) and differential pressure pipe nut seat two (9) are fixed to the outer walls of the catalyst housing (27). 16) The differential pressure tube assembly one (7) is fixed on the outer wall of the catalyst housing (27) and the outer wall of the rear cone (15), respectively. The differential pressure tube assembly one (7) is fixed on the differential pressure tube nut seat one (9), and the differential pressure tube assembly two (8) is fixed on the differential pressure tube nut seat two (16). The EGR flange (10) is connected and fixed to one end of the EGR tube (11). The other end of the EGR tube (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. 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 differential pressure pipe bracket (19) is fixed on the outer wall of the catalyst housing (27), the differential pressure pipe bracket cover plate (20) covers the differential pressure pipe bracket (19) and is fixedly connected, the right bracket (18) is fixed on 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 anticorrosion structure of a three-terminal package assembly according to claim 1, wherein: The differential pressure pipe support cover plate (20) and the differential pressure pipe support (19) are fixedly connected by hexagonal flange bolts (21).

3. The anticorrosion structure of a three-terminal package assembly according to claim 1, wherein: The materials of the intake flange (1), intake upper shell (2), intake lower shell (4), rear cone (15), front cone (22), catalyst housing (27), exhaust pipe (33), differential pressure pipe bracket (19), and differential pressure pipe bracket cover (20) are all 441 ferritic stainless steel. The materials of the oxygen sensor nut one (3), oxygen sensor nut two (14), upper heat shield (5), lower heat shield (6), differential pressure pipe assembly one (7), differential pressure pipe assembly two (8), differential pressure pipe nut seat one (9), differential pressure pipe nut seat two (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 materials of the hexagonal flange bolt (21) and flange bolt (32) are 35 steel.

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