Engine exhaust manifold and heat insulation plate thereof

Abstract

The engine exhaust manifold comprises an exhaust manifold body, a rear end flange plate is integrally arranged at the rear end of the exhaust manifold body, and the front end of the exhaust manifold body and a front end butt joint plate are integrally arranged; a heat insulation plate assembly is arranged outside the exhaust manifold body, the heat insulation plate assembly wraps the exhaust manifold body, and a high-temperature warning plate is installed on the outer surface of the heat insulation plate assembly. The front end of the exhaust manifold main body is communicated with an engine cylinder through a front-end butting plate, and the rear end of the exhaust manifold main body is communicated with a three-way catalyst through a rear-end flange plate. Through the arrangement of the dynamic balance system, the horn-shaped air inlet pipe cover reduces the back pressure and improves the power; and the spiral guide groove enhances waste gas mixing and reduces emission resistance. The heat insulation plate assembly is efficient in heat insulation, protects engine compartment components and enhances system stability. The high-temperature warning board visually displays the high-temperature state, and safe operation is ensured. The overall design improves exhaust efficiency, guarantees system stability, and reduces potential safety hazards.

Description

Technical Field

[0001] The present invention relates to the technical field of exhaust manifolds and heat insulation boards, and in particular to an engine exhaust manifold and a heat insulation board thereof. Background Art

[0002] During engine operation, the exhaust manifold, as a key component of the exhaust system, bears the important responsibility of collecting and transporting high-temperature exhaust gases. Traditional exhaust manifolds have many design deficiencies. First, in terms of exhaust manifold structural design, the common exhaust manifold branch structure is relatively simple, and the connection method between the branch pipe openings and the cylinders often cannot well adapt to the characteristics of exhaust gas discharge. For example, at the cylinder outlet, the channel cross-section design lacks specificity, making it difficult to fully utilize the exhaust pulse effect while ensuring smooth exhaust gas discharge, resulting in low exhaust efficiency, which in turn affects the engine's power output and fuel economy. In addition, the airflow channel inside the exhaust manifold is not optimized. For example, the inner wall is smooth and there is a lack of a reasonable guiding structure, which makes it easy for the exhaust gas to generate turbulence and vortexes during flow, increasing airflow resistance. This not only further reduces exhaust efficiency, but may also cause uneven pressure within the exhaust system, affecting engine stability.

[0003] Secondly, regarding the design and application of heat shields, traditional heat shields usually use relatively single materials and simple structures. In terms of material selection, the thermal insulation performance of most heat shields is limited, and it is difficult to effectively prevent the large amount of heat generated by the exhaust manifold from being transferred to the surrounding environment. This will not only cause the temperature in the engine compartment to be too high, affecting the normal operation and service life of other components, but may also pose a potential threat to the safety of the vehicle. In terms of structural design, the heat shield and the exhaust manifold do not fit well, with many gaps and loose parts, making it easy for heat to dissipate from these weak links, greatly reducing the insulation effect. Moreover, traditional heat shields are not convenient in installation and maintenance, and the complex installation method increases maintenance costs and time.

[0004] Third, regarding the overall safety of exhaust systems, existing technologies lack an effective high-temperature warning mechanism. The exhaust manifold reaches extremely high temperatures during operation, and uninformed personnel, such as nearby personnel or maintenance personnel, can easily touch hot components, potentially causing burns and other safety hazards. Traditional exhaust systems lack intuitive and reliable high-temperature warning devices, effectively preventing personnel from being alerted to potential heat hazards.

[0005] Therefore, it is very necessary to invent a kind of engine exhaust manifold and heat shield thereof. Summary of the Invention

[0006] The present invention provides an engine exhaust manifold and a heat shield plate thereof, and the present invention provides the following technical solutions: comprising an exhaust manifold body, a rear end flange, a front end docking plate, a heat shield plate assembly and a high temperature warning plate, wherein the rear end of the exhaust manifold body is integrally provided with a rear end flange, and the front end thereof is integrally provided with the front end docking plate; a heat shield plate assembly is provided on the outside of the exhaust manifold body, and the heat shield plate assembly covers the exhaust manifold body, wherein a high temperature warning plate is installed on the outer surface of the heat shield plate assembly; the front end of the exhaust manifold body is connected to the engine cylinder through the front end docking plate, and the rear end of the exhaust manifold body is connected to the three-way catalytic converter through the rear end flange.

[0007] Preferably, the exhaust manifold body includes an exhaust main pipe, a branch pipe opening, an intake pipe cover and a guide groove. The exhaust main pipe, the branch pipe opening and the intake pipe cover are integrally arranged together, and a guide groove is provided on the inner wall of the exhaust main pipe; a rear end flange is integrally provided at one end of the exhaust main pipe; and several intake pipe covers are integrally arranged together with the front end docking plate.

[0008] Preferably, the intake pipe cover is a trumpet-shaped pipe cover as a whole, and the inner diameter of the intake pipe cover is designed to decrease gradually. The channel cross-section is large near the cylinder outlet and gradually decreases towards the branch pipe outlet.

[0009] Preferably, the branch pipe opening and the exhaust main pipe have the same inner diameter, and the guide groove provided on the inner wall of the exhaust main pipe is a spiral groove provided along the axial direction of the exhaust main pipe.

[0010] Preferably, the overall axes of the exhaust main pipe, branch pipe opening and intake pipe cover are on the same horizontal line, and together they constitute a complete exhaust manifold, and the exhaust manifold as a whole is an "F"-shaped structure.

[0011] Preferably, the heat insulation plate assembly integrally arranged on the outside of the exhaust manifold body includes an upper heat insulation plate, a lower heat insulation plate, a partition plate, mounting ears and fastening bolts. The upper heat insulation plate and the lower heat insulation plate have the same structure, and both are integrally provided with partition plates and mounting ears. The mounting ears provided on the upper heat insulation plate and the lower heat insulation plate are tightly fixed together by the fastening bolts.

[0012] Preferably, the upper heat insulation plate and the lower heat insulation plate fit in with the upper and lower parts of the exhaust manifold, and the upper heat insulation plate and the lower heat insulation plate are geometric structures made of high heat insulation materials that fit the exhaust manifold; the partition plate integrally arranged between the upper heat insulation plate and the lower heat insulation plate is located between the intake pipe covers, which is used to block the heat transfer between the intake pipe covers.

[0013] Preferably, the high temperature warning plate installed on the surface of the upper insulation board includes a thermal conductive substrate, indication words, a temperature-sensitive color-changing sticker, a protective sticker and rivets. The thermal conductive substrate is provided with indication words, and a temperature-sensitive color-changing sticker is attached to its surface, and a protective sticker is attached to the outer surface of the temperature-sensitive color-changing sticker; the thermal conductive substrate, the temperature-sensitive color-changing sticker and the protective sticker are installed on the surface of the upper insulation board by the rivets.

[0014] Preferably, the heat-conducting substrate is made of a heat-conducting metal material, and the temperature-sensitive color-changing patch attached to the heat-conducting substrate becomes transparent when a threshold value is reached.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1. The intake manifold housing of the exhaust manifold body of this invention is designed as a trumpet-shaped housing with a gradually decreasing inner diameter. The larger cross-section of the channel near the cylinder outlet effectively reduces initial backpressure during exhaust gas discharge, allowing exhaust gas to exit the cylinder more smoothly, reducing energy loss during the engine's exhaust stroke and improving engine power output. This design also helps better utilize the exhaust pulse effect. As the inner diameter gradually decreases toward the branch pipe outlet, the exhaust gas velocity gradually increases during flow, enhancing the pulse effect, further improving exhaust efficiency and improving engine fuel economy.

[0017] 2. The spiral guide grooves on the inner wall of the exhaust manifold of the present invention create a spiral flow path for the exhaust gas during its flow, increasing the degree of exhaust gas disturbance and promoting better mixing of exhaust gases from different sources. This results in a more uniform exhaust gas composition, facilitating subsequent catalytic reactions in the three-way catalytic converter and more effectively reducing harmful gas emissions. Furthermore, the spiral flow pattern reduces boundary layer separation between the exhaust gas and the inner wall of the manifold, reducing the generation of vortices, thereby reducing exhaust gas flow resistance to a certain extent and improving the overall performance of the exhaust system.

[0018] 3. High-efficiency heat insulation ensures system stability: The heat insulation board assembly of the present invention adopts a structure in which an upper heat insulation board and a lower heat insulation board are matched, and both are made of high-insulation materials, which can greatly improve the heat insulation effect, effectively block the heat generated by the exhaust manifold from being transferred to the surrounding environment, reduce the temperature in the engine compartment, protect other components from being affected by high temperature, extend their service life, and improve the stability and reliability of the entire engine system. The partition plate integrally arranged on the upper heat insulation board and the lower heat insulation board is located between the intake pipe covers, which can further block the heat transfer between the intake pipe covers, avoid the accumulation and diffusion of heat between the intake pipe covers, and enhance the pertinence and effectiveness of heat insulation. At the same time, the upper heat insulation board and the lower heat insulation board are tightly fixed together by mounting ears and fastening bolts. This structural design not only facilitates the installation and disassembly of the heat insulation board, and facilitates subsequent maintenance and replacement, but also ensures that the heat insulation board fits tightly with the exhaust manifold, reduces gaps for heat loss, and improves heat insulation performance.

[0019] 4. Intuitive warnings ensure safe operation: The design of the high-temperature warning plate of the present invention provides a strong guarantee for the safe operation of the exhaust system. The thermally conductive substrate is made of thermally conductive metal material, which can quickly sense the heat transferred by the exhaust manifold. When the temperature reaches the threshold of the temperature-sensitive color-changing sticker, the temperature-sensitive color-changing sticker becomes transparent. At this time, the words originally set on the thermally conductive substrate will appear clearly, and the surrounding personnel will be visually warned that the exhaust manifold is in a high-temperature state, avoiding accidental touch and causing burns and other safety accidents. The protective sticker attached to the outer surface of the temperature-sensitive color-changing sticker can effectively protect the temperature-sensitive color-changing sticker from erosion and damage from the external environment, extend its service life, and ensure the long-term stable operation of the high-temperature warning function. Moreover, the thermally conductive substrate, the temperature-sensitive color-changing sticker and the protective sticker are installed on the surface of the upper insulation board by rivets. The installation method is simple and reliable, which ensures a firm connection between the high-temperature warning plate and the insulation board. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0021] Figure 2 It is a schematic diagram of the explosion structure of the present invention.

[0022] Figure 3 It is a structural schematic diagram of the exhaust manifold body of the present invention.

[0023] Figure 4 This invention Figure 1 Schematic diagram of the half-section structure.

[0024] Figure 5 It is a structural schematic diagram of the heat insulation board assembly of the present invention.

[0025] Figure 6 It is a schematic diagram of the layered structure of the high temperature warning plate of the present invention.

[0026] In the picture:

[0027] Exhaust manifold body 1, exhaust main pipe 11, branch pipe outlet 12, intake pipe cover 13, guide groove 14, rear end flange 2, front end docking plate 3, heat insulation plate assembly 4, upper heat insulation plate 41, lower heat insulation plate 42, partition plate 43, mounting ears 44, fastening bolts 45, high temperature warning plate 5, heat conductive substrate 51, indication words 52, temperature sensitive color changing sticker 53, protective sticker 54, rivet 55. DETAILED DESCRIPTION

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0029] As attached Figure 1-6 As shown:

[0030] The present invention provides an engine exhaust manifold and a heat shield plate thereof, comprising an exhaust manifold body 1, a rear end flange 2, a front end docking plate 3, a heat shield plate assembly 4 and a high temperature warning plate 5. The rear end of the exhaust manifold body 1 is integrally provided with a rear end flange 2, and its front end is integrally provided with the front end docking plate 3; a heat shield plate assembly 4 is provided on the outside of the exhaust manifold body 1, and the heat shield plate assembly 4 covers the exhaust manifold body 1, wherein a high temperature warning plate 5 is installed on the outer surface of the heat shield plate assembly 4; the front end of the exhaust manifold body 1 is connected to the engine cylinder through the front end docking plate 3, and the rear end is connected to the three-way catalytic converter through the rear end flange 2.

[0031] Furthermore, the structure of the exhaust manifold body 1 is extremely critical. It consists of an exhaust main pipe 11, a branch pipe opening 12, an intake pipe cover 13 and a guide groove 14. The exhaust main pipe 11, the branch pipe opening 12 and the intake pipe cover 13 are integrated through a precision casting process. The material used is a high-temperature resistant and high-strength nickel-based alloy. This alloy can withstand a high-temperature environment of up to 800°C-1000°C, ensuring the stability of the exhaust manifold under long-term high-load operation of the engine. A guide groove 14 is provided on the inner wall of the exhaust main pipe 11. The guide groove 14 has a depth of 3-5mm and a width of 5-8mm. Its function is to optimize the flow state of the exhaust gas in the pipe. One end of the exhaust main pipe 11 is integrally formed with the rear end flange 2. The rear end flange 2 is usually made of high-strength cast iron with a thickness of 10-15mm. The flatness of the installation surface is ensured to be within ±0.05mm through mechanical processing to ensure the sealing of the connection with the three-way catalytic converter. Several intake pipe covers 13 are integrally formed with the front end docking plate 3. The number of intake pipe covers 13 depends on the number of engine cylinders. For example, a four-cylinder engine is equipped with four intake pipe covers 13. The thickness of the connection part between the intake pipe cover 13 and the front end docking plate 3 is 8-12mm to ensure the connection strength.

[0032] Furthermore, the intake shroud 13 is an overall trumpet-shaped shroud. This unique shape facilitates the smooth introduction of exhaust gases. Its inner diameter is designed to gradually decrease, starting with a larger diameter near the cylinder outlet, typically 30-40 mm. As it extends toward the branch pipe opening 12, the inner diameter gradually decreases to approximately 20-30 mm, matching the inner diameter of the branch pipe opening 12. The intake shroud 13 is also made of a high-temperature-resistant nickel-based alloy. Through precision casting and subsequent machining, the inner wall roughness of the shroud is maintained between Ra0.8 and Ra1.6 μm, reducing exhaust gas flow resistance.

[0033] Furthermore, the inner diameters of the branch pipe opening 12 and the exhaust main pipe 11 are consistent, both of which are 25-35mm, ensuring a smooth transition of the exhaust gas during the flow process and avoiding airflow shock and pressure loss due to sudden changes in the pipe diameter. The guide groove 14 on the inner wall of the exhaust main pipe 11 is a spiral groove, which is opened along the axial direction of the exhaust main pipe 11. The pitch of the spiral groove is generally designed to be 15-20mm. This design encourages the exhaust gas to form a spiral flow in the exhaust main pipe 11, enhances the exhaust gas mixing effect, improves the exhaust efficiency, and reduces the friction resistance between the airflow and the pipe wall. The guide groove 14 is precisely formed on the inner wall of the exhaust main pipe 11 through CNC machining technology to ensure the shape accuracy and surface quality of the groove.

[0034] Furthermore, the overall axes of the exhaust main pipe 11, branch pipe opening 12, and intake pipe cover 13 are aligned horizontally. This layout greatly simplifies the exhaust system structure and reduces airflow losses caused by pipe bends. Together, they form a complete exhaust manifold with an overall "F"-shaped structure. The "F"-shaped design fully considers the spatial layout within the engine compartment, achieving efficient exhaust gas collection and transportation functions within a limited space. The overall length of the exhaust manifold varies depending on the engine model and installation location, generally ranging from 300-500mm.

[0035] Furthermore, the heat insulation plate assembly 4 on the outside of the exhaust manifold body 1 is composed of an upper heat insulation plate 41, a lower heat insulation plate 42, a partition plate 43, a mounting ear 44 and a fastening bolt 45. The upper heat insulation plate 41 and the lower heat insulation plate 42 have the same structure and are both made of aerogel composite materials with a thickness of 15-20 mm. The aerogel composite material has an extremely low thermal conductivity coefficient and can effectively block heat transfer. Both are integrally formed with a partition plate 43 and a mounting ear 44. The partition plate 43 is about 5-8 mm thick and is used to block heat transfer between the intake pipe covers 13. The length of the mounting ear 44 is 20-30 mm and the width is 15-20 mm. The mounting ears 44 on the upper heat insulation plate 41 and the lower heat insulation plate 42 are tightly fixed together by stainless steel fastening bolts 45 of M8-M10 specifications to ensure that the heat insulation plate assembly 4 is firmly covered on the outside of the exhaust manifold body 1.

[0036] Furthermore, the upper and lower heat shields 41 and 42 are molded and meticulously finished to precisely match the upper and lower portions of the exhaust manifold, achieving a precision fit within ±1mm to achieve optimal insulation. Their integrally formed partition plate 43, located between the intake manifold covers 13, effectively blocks heat transfer between the intake manifold covers 13, further enhancing the insulation performance of the heat shield assembly 4 and reducing the disordered diffusion of heat within the exhaust manifold. The outer surface of the heat shields is treated for wear and corrosion resistance, ensuring they can withstand the complex environment of the engine compartment.

[0037] Furthermore, the high temperature warning plate 5 installed on the surface of the upper heat insulation board 41 is composed of a heat-conducting substrate 51, a display word 52, a temperature-sensitive color-changing sticker 53, a protective sticker 54 and a rivet 55. The heat-conducting substrate 51 is made of an aluminum alloy material with a thickness of 3-5 mm. Its good thermal conductivity can quickly transfer the heat of the exhaust manifold to the temperature-sensitive color-changing sticker 53. The display word 52 is formed on the surface of the heat-conducting substrate 51 through a laser etching process. The content is a striking warning message such as "high temperature danger". The height of the word is 5-10 mm, ensuring clear visibility and durability. The temperature-sensitive color-changing sticker 53 is attached to the surface of the heat-conducting substrate 51. The size is cut according to the size of the heat-conducting substrate 51 and generally covers 80%-90% of the surface of the heat-conducting substrate 51. The protective sticker 54 is attached to the outer surface of the temperature-sensitive color-changing sticker 53 and is made of a transparent PET material with a thickness of 0.2-0.3 mm. It is used to protect the temperature-sensitive color-changing sticker 53 from external environmental erosion, such as dust, water vapor, etc.

[0038] Furthermore, the aluminum alloy material of the thermally conductive substrate 51 can efficiently conduct heat. When the exhaust manifold temperature rises, the heat is quickly transferred to the temperature-sensitive color-changing sticker 53. The threshold temperature set for the temperature-sensitive color-changing sticker 53 is generally between 60°C and 100°C. When the temperature reaches this threshold, the temperature-sensitive color-changing sticker 53 changes from its original opaque state to transparent, making the indication 52 below clearly visible, thereby serving as a warning to remind the operator that the exhaust manifold is in a high-temperature state and to avoid safety accidents. The rivets 55 are made of stainless steel with a diameter of 3-4mm. The number is determined according to the size and installation stability requirements of the high-temperature warning plate 5, generally 4-6, to firmly install the thermally conductive substrate 51, the temperature-sensitive color-changing sticker 53 and the protective sticker 54 on the surface of the upper insulation board 41.

[0039] How it works

[0040] First, when the engine is operating, high-temperature, high-pressure exhaust gas generated by each cylinder is discharged from the cylinder outlet. The large cross-section of the intake manifold 13 near the cylinder outlet quickly collects the exhaust gas, reducing initial resistance to exhaust gas discharge and allowing it to smoothly enter the exhaust manifold body 1. As the inner diameter of the intake manifold 13 gradually decreases, the exhaust gas's velocity gradually increases as it flows toward the branch pipe opening 12, creating a pulse effect that facilitates subsequent exhaust gas propulsion. The branch pipe opening 12 is consistent with the inner diameter of the exhaust main pipe 11, ensuring a smooth transition of exhaust gas into the exhaust main pipe 11 and avoiding airflow shock and pressure loss caused by sudden changes in pipe diameter. The spiral guide grooves 14 on the inner wall of the exhaust main pipe 11 create a spiral flow for the incoming exhaust gas. This not only enhances exhaust mixing and makes the exhaust gas composition more uniform, facilitating subsequent purification reactions in the three-way catalytic converter, but also reduces frictional resistance between the airflow and the pipe wall, improving exhaust efficiency and enabling more efficient exhaust gas transmission to the rear flange 2, where it connects to the three-way catalytic converter for subsequent exhaust gas treatment.

[0041] Regarding thermal insulation, the upper and lower insulation panels 41 and 42 of the heat shield assembly 4 are made of aerogel composite materials with extremely low thermal conductivity. They tightly wrap around the exterior of the exhaust manifold body 1, with a fit tolerance within ±1mm. This effectively blocks heat generated by the exhaust manifold body 1 from being transferred to the surrounding environment, minimizing heat loss, lowering the temperature within the engine compartment, and protecting surrounding components from high temperatures. A partition plate 43, integrally formed with the upper and lower insulation panels and located between the intake manifold covers 13, further blocks heat transfer between the intake manifold covers 13, preventing disordered heat diffusion within the exhaust manifold and enhancing the overall thermal insulation performance of the heat shield assembly 4.

[0042] In addition, the heat generated by the operation of the exhaust manifold is transferred to the heat insulation plate assembly 4 through the exhaust manifold body 1, and then conducted to the high temperature warning plate 5 installed on the surface of the upper heat insulation plate 41. The heat conductive substrate 51 of the high temperature warning plate 5 is made of aluminum alloy material, which can quickly transfer heat to the temperature-sensitive color-changing sticker 53. When the temperature of the exhaust manifold rises to the threshold temperature (60℃-100℃) set by the temperature-sensitive color-changing sticker 53, the temperature-sensitive color-changing sticker 53 changes from its original opaque state to transparent, so that the eye-catching words 52 (such as "High temperature danger or high temperature do not touch") formed below by the laser etching process are clearly visible, thereby reminding the operator that the exhaust manifold is in a high temperature state to avoid safety accidents. The protective sticker 54 protects the temperature-sensitive color-changing sticker 53 from erosion by external environmental factors such as dust and water vapor to ensure its normal operation.

[0043] Exhaust manifold production process

[0044] 1. Raw material preparation: Purchase high-temperature resistant and high-strength nickel-based alloy materials for manufacturing the exhaust main pipe 11, branch pipe opening 12, and intake pipe cover 13. Also prepare high-strength cast iron for manufacturing the rear flange 2.

[0045] 2. Casting: Using a precision casting process, nickel-based alloy material is cast into the preliminary shapes of the exhaust main pipe 11, branch pipe opening 12, and intake pipe cover 13, forming them into an integral piece. During the casting process, parameters such as temperature and casting speed are strictly controlled to ensure the quality and dimensional accuracy of the casting.

[0046] 3. Machining: The cast exhaust manifold body undergoes machining. Using CNC machining equipment, a spiral guide groove 14 with a depth of 3-5mm and a width of 5-8mm is precisely machined into the inner wall of the exhaust main pipe 11, ensuring both shape accuracy and surface quality. The rear flange 2 is machined to ensure the flatness of its mounting surface is within ±0.05mm. The intake manifold cover 13 undergoes subsequent machining to ensure an inner wall roughness between Ra0.8 and Ra1.6μm.

[0047] 4. Quality Inspection: The processed exhaust manifold body is subjected to comprehensive quality inspection, including dimensional accuracy inspection, appearance defect inspection, material performance inspection, etc. to ensure that the various performance indicators of the exhaust manifold body meet the design requirements.

[0048] Heat insulation board assembly production process

[0049] 1. Raw material preparation: Purchase aerogel composite materials for making upper insulation board 41 and lower insulation board 42. Prepare the same or compatible materials for making partition board 43 and mounting ears 44, as well as M8-M10 stainless steel fastening bolts 45.

[0050] 2. Mold Forming: According to the design dimensions, molds for the upper insulation board 41 and the lower insulation board 42 are made. The aerogel composite material is placed in the mold and formed into the upper insulation board 41 and the lower insulation board 42 through a compression molding process. At the same time, the partition board 43 and the mounting ears 44 are integrally formed.

[0051] 3. Fine Machining: The upper and lower heat shields 41 and 42 are finely machined to ensure that the fit between them and the upper and lower portions of the exhaust manifold is within ±1 mm. The outer surfaces of the heat shields are treated to impart a certain degree of wear resistance and corrosion resistance.

[0052] 4. Assembly: The upper insulation board 41 and the lower insulation board 42 are tightly fixed together through the mounting ears 44 and the stainless steel fastening bolts 45 to complete the assembly of the insulation board assembly 4.

[0053] 5. Quality inspection: Perform quality inspection on the insulation board assembly 4, including thermal insulation performance inspection, structural strength inspection, installation stability inspection, etc., to ensure that it can meet actual use requirements.

[0054] High temperature warning board production process

[0055] 1. Raw material preparation: Purchase aluminum alloy material with a thickness of 3-5 mm to make a thermal conductive substrate 51, prepare temperature-sensitive color-changing sticker 53, transparent PET protective sticker 54 with a thickness of 0.2-0.3 mm, and stainless steel rivets 55.

[0056] 2. Word production: A laser etching process is used to form eye-catching words 52 on the surface of the thermal conductive substrate 51, such as "High Temperature Danger". The height of the words is ensured to be 5-10 mm, clearly visible and durable.

[0057] 3. Assembly: Attach the temperature-sensitive color-changing sticker 53 to the surface of the thermally conductive substrate 51. Cut the sticker 53 according to the size of the thermally conductive substrate 51, generally covering 80%-90% of the surface of the thermally conductive substrate 51. Then, attach the protective sticker 54 to the outer surface of the temperature-sensitive color-changing sticker 53. Finally, use stainless steel rivets 55 with a diameter of 3-4 mm, depending on the size and installation stability requirements of the high temperature warning plate 5 (generally 4-6 rivets), to firmly install the thermally conductive substrate 51, temperature-sensitive color-changing sticker 53, and protective sticker 54 together.

[0058] 4. Quality inspection: Perform quality inspection on the high temperature warning plate 5, including thermal conductivity inspection, temperature-sensitive color change performance inspection, installation firmness inspection, etc., to ensure that it can play a normal warning role.

[0059] Overall assembly process

[0060] The finished exhaust manifold body 1, heat shield assembly 4, and high-temperature warning plate 5 are transported to the assembly workshop. First, the heat shield assembly 4 is wrapped around the exterior of the exhaust manifold body 1 and secured securely with mounting ears 44 and fastening bolts 45. The high-temperature warning plate 5 is then installed on the upper heat shield 41, ensuring accurate positioning and secure fixation. The assembled engine exhaust manifold and its heat shield undergo comprehensive quality and performance testing, including tests for air tightness, thermal insulation performance, and high-temperature warning functionality. Qualified products are packaged and prepared for shipment.

[0061] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. An engine exhaust manifold and a heat shield therefor, characterized in that: The exhaust manifold comprises an exhaust manifold body (1), a rear end flange (2), a front end docking plate (3), a heat shield assembly (4) and a high temperature warning plate (5), wherein the rear end of the exhaust manifold body (1) is integrally provided with a rear end flange (2), and the front end thereof is integrally provided with the front end docking plate (3); a heat shield assembly (4) is provided on the outside of the exhaust manifold body (1), and the heat shield assembly (4) covers the exhaust manifold body (1), wherein a high temperature warning plate (5) is installed on the outer surface of the heat shield assembly (4); the front end of the exhaust manifold body (1) is connected to the engine cylinder through the front end docking plate (3), and the rear end of the exhaust manifold body (1) is connected to the three-way catalytic converter through the rear end flange (2).

2. An engine exhaust manifold and heat shield therefor according to claim 1, characterized in that: The exhaust manifold body (1) comprises an exhaust main pipe (11), a branch pipe opening (12), an intake pipe cover (13) and a guide groove (14); the exhaust main pipe (11), the branch pipe opening (12) and the intake pipe cover (13) are integrally arranged together, and the inner wall of the exhaust main pipe (11) is provided with a guide groove (14); one end of the exhaust main pipe (11) is integrally provided with a rear end flange (2); and a plurality of the intake pipe covers (13) are integrally arranged together with a front end docking plate (3).

3. An engine exhaust manifold and heat shield therefor according to claim 2, characterized in that: The intake pipe cover (13) is a trumpet-shaped pipe cover as a whole. The inner diameter of the intake pipe cover (13) is designed to decrease gradually. The channel cross section is large near the cylinder outlet and gradually decreases towards the branch pipe opening (12).

4. An engine exhaust manifold and heat shield therefor according to claim 3, characterized in that: The branch pipe opening (12) and the exhaust main pipe (11) have the same inner diameter, and the guide groove (14) provided on the inner wall of the exhaust main pipe (11) is a spiral groove, which is provided along the axial direction of the exhaust main pipe (11).

5. An engine exhaust manifold and heat shield therefor according to claim 4, characterized in that: The exhaust main pipe (11), the branch pipe opening (12) and the intake pipe cover (13) have their overall axes on the same horizontal line, and together they form a complete exhaust manifold, which is an "F"-shaped structure as a whole.

6. An engine exhaust manifold and heat shield therefor according to claim 5, characterized in that: The heat insulation plate assembly (4) integrally arranged on the outside of the exhaust manifold body (1) comprises an upper heat insulation plate (41), a lower heat insulation plate (42), a partition plate (43), a mounting ear (44) and a fastening bolt (45). The upper heat insulation plate (41) and the lower heat insulation plate (42) have the same structure, and both are integrally provided with a partition plate (43) and a mounting ear (44). The mounting ears (44) provided on the upper heat insulation plate (41) and the lower heat insulation plate (42) are tightly fixed together by means of the fastening bolt (45).

7. An engine exhaust manifold and heat shield therefor according to claim 6, characterized in that: The upper heat insulation plate (41) and the lower heat insulation plate (42) are matched with the upper and lower parts of the exhaust manifold. The upper heat insulation plate (41) and the lower heat insulation plate (42) are made of high heat insulation materials and have a geometric structure that fits the exhaust manifold. The partition plate (43) integrally arranged between the upper heat insulation plate (41) and the lower heat insulation plate (42) is located between the intake pipe cover (13) and is used to block heat transfer between the intake pipe covers (13).

8. An engine exhaust manifold and heat shield therefor according to claim 7, characterized in that: The high temperature warning plate (5) installed on the surface of the upper heat insulation plate (41) comprises a heat conductive substrate (51), a display word (52), a temperature-sensitive color-changing sticker (53), a protective sticker (54) and a rivet (55); the heat conductive substrate (51) is provided with the display word (52), a temperature-sensitive color-changing sticker (53) is attached to its surface, and a protective sticker (54) is attached to the outer surface of the temperature-sensitive color-changing sticker (53); the heat conductive substrate (51), the temperature-sensitive color-changing sticker (53) and the protective sticker (54) are installed on the surface of the upper heat insulation plate (41) by the rivet (55).

9. An engine exhaust manifold and heat shield therefor according to claim 8, characterized in that: The heat-conducting substrate (51) is made of a heat-conducting metal material, and the temperature-sensitive color-changing patch (53) attached to the heat-conducting substrate (51) becomes transparent when the temperature reaches a threshold.

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