Exhaust manifolds, internal combustion engines, and vehicles

Abstract

The present application relates to an exhaust manifold, comprising an exhaust manifold body, a barrier layer and a heat-resistant layer. The barrier layer is provided on the outer wall of the exhaust manifold body, and the heat-resistant layer is provided on the inner wall of the exhaust manifold body. The barrier layer is used to block the heat exchange between the inside and outside of the exhaust manifold body, and the heat-resistant layer is made of a heat-resistant material. By means of the barrier layer to block the heat exchange between the inside and outside of the exhaust manifold, the heat loss caused by the heat in the exhaust manifold diffusing outward can be reduced, and the wiring harness, sensors and other pipes near the exhaust manifold can be protected. Moreover, the barrier layer can replace the exhaust manifold heat shield, saving the installation space and cost of installing the heat shield. The inner side of the exhaust manifold body has the highest working temperature and the most complex working environment. By providing a heat-resistant layer on the inner wall of the exhaust manifold body, the heat resistance of the exhaust manifold can be improved with the help of the heat-resistant layer, so that it can work in harsh working environments and the service life of the exhaust manifold can be increased.

Description

Technical Field

[0001] The present application relates to the field of automobile power technology, in particular to an exhaust manifold, an internal combustion engine and a vehicle. Background Art

[0002] During the development and design of internal combustion engines, achieving energy conservation, environmental protection, and reduced fuel consumption often requires increasing the engine's explosion pressure. As explosion pressure and exhaust temperature increase, the exhaust manifold's operating environment becomes increasingly demanding. Furthermore, to meet environmental requirements, additional structures are often added to the engine, making it difficult to improve exhaust manifold performance within the limited space available. Summary of the Invention

[0003] Based on this, an exhaust manifold, an internal combustion engine and a vehicle are provided, which improve the performance of the exhaust manifold with a simpler structure, thereby meeting working requirements and increasing the service life of the exhaust manifold.

[0004] In one aspect of the present application, an exhaust manifold is provided, comprising:

[0005] exhaust manifold body;

[0006] a barrier layer disposed on an outer wall of the exhaust manifold body; and

[0007] a heat-resistant layer provided on the inner wall of the exhaust manifold body;

[0008] The barrier layer is used to block the heat exchange between the inside and outside of the exhaust manifold body, and the heat-resistant layer is made of a heat-resistant material.

[0009] The exhaust manifold described above comprises at least an exhaust manifold body, a barrier layer, and a heat-resistant layer, wherein the barrier layer and the heat-resistant layer are respectively arranged on the outer wall and the inner wall of the exhaust manifold body. By means of the barrier layer, heat exchange between the inside and outside of the exhaust manifold is blocked, heat loss caused by heat diffusion outward in the exhaust manifold can be reduced, and parts near the exhaust manifold, such as wiring harnesses, sensors, and other pipelines, can also be protected. Moreover, the barrier layer can replace the exhaust manifold heat shield in the related art, saving the installation space and cost of installing the heat shield. The inner side of the exhaust manifold body has the highest operating temperature and the most complex working environment. By providing a heat-resistant layer on the inner wall of the exhaust manifold body, the heat-resistant performance of the exhaust manifold can be improved with the help of the heat-resistant layer, thereby enabling it to operate in harsh working environments and also extending the service life of the exhaust manifold.

[0010] In one embodiment, the heat-resistant material includes boron nitride. Boron nitride has the characteristics of high temperature resistance and can be oxidized at high temperatures to form a viscous liquid or solid-liquid state, and has the ability to self-heal cracks.

[0011] In one embodiment, the heat-resistant material further comprises at least one of chromium boride, zirconium boride, and titanium boride. This allows the metal in the metal boride to better bond with the exhaust manifold body, increasing interlayer bonding strength and further improving exhaust manifold performance.

[0012] In one embodiment, the heat-resistant material comprises a metal oxide;

[0013] The metal oxide includes at least one of aluminum oxide, titanium dioxide, and chromium oxide. Thus, ceramic materials such as aluminum oxide, titanium dioxide, and chromium oxide, or mixtures thereof, have good high temperature resistance.

[0014] In one embodiment, the heat-resistant material further comprises silicon dioxide. While silicon dioxide itself lacks the high-temperature resistance of metal oxides, it has a higher adhesive strength. The heat-resistant layer formed by mixing silicon dioxide and metal oxides combines the high-temperature resistance of metal oxides with the adhesiveness of silicon dioxide at high temperatures.

[0015] In one embodiment, the mass ratio of the silicon dioxide to the metal oxide is 0.5 to 20. In this way, the adhesion of the heat-resistant layer can be improved while meeting the requirements of high-temperature working conditions.

[0016] In one embodiment, the exhaust manifold body has an exhaust port;

[0017] The thickness of the heat-resistant layer gradually increases along the extension direction toward the exhaust port on the inner wall, thus meeting the actual requirements at the exhaust port.

[0018] In one embodiment, the ratio of the maximum value of the thickness dimension to the minimum value of the thickness dimension is less than or equal to 8. In this way, while satisfying the requirement of the heat-resistant layer for improving the performance of the exhaust manifold, the risk of the heat-resistant layer peeling off due to stress concentration, resulting in heat-resistant failure of the heat-resistant layer, is reduced.

[0019] In one embodiment, the thickness is 0.005 mm to 1 mm. This can ensure that the heat-resistant layer improves the performance of the exhaust manifold while reducing the risk of the heat-resistant layer peeling off due to stress concentration, resulting in heat-resistant failure of the heat-resistant layer.

[0020] In one embodiment, the material of the barrier layer includes metal oxide;

[0021] The metal oxide includes at least one of aluminum oxide, titanium dioxide, and chromium oxide. Thus, ceramic materials such as aluminum oxide, titanium dioxide, and chromium oxide, or mixtures thereof, have good high temperature resistance.

[0022] In one embodiment, the barrier layer also includes silicon dioxide. While silicon dioxide itself lacks the high-temperature resistance of metal oxides, it has superior adhesion. The heat-resistant layer formed by mixing silicon dioxide with metal oxides combines the high-temperature resistance of metal oxides with the adhesion of silicon dioxide at high temperatures.

[0023] In one embodiment, the mass ratio of the silicon dioxide to the metal oxide is 0.01 to 10. In this way, the adhesion of the heat-resistant layer can be improved while meeting the requirements of high-temperature working conditions.

[0024] Another aspect of the present application provides an internal combustion engine comprising the above-mentioned exhaust manifold. Thus, by using the above-mentioned exhaust manifold with improved heat resistance and longer service life, the thermal efficiency of the internal combustion engine is improved, fuel consumption is reduced, and carbon emissions are reduced. The probability of internal combustion engine failure is also greatly reduced, thereby extending the service life of the internal combustion engine.

[0025] In another aspect of the present application, a vehicle is provided, comprising the above-mentioned internal combustion engine. Thus, by using the above-mentioned internal combustion engine, the performance of the vehicle is also improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic structural diagram of an exhaust manifold according to an embodiment of the present application;

[0027] Figure 2 for Figure 1 a top view of the structure shown;

[0028] Figure 3 for Figure 2 AA cross-sectional schematic diagram of the top view shown.

[0029] Description of reference numerals:

[0030] 100. Exhaust manifold; 110. Exhaust manifold body; 111. Exhaust port; 120. Barrier layer; 130. Heat-resistant layer. DETAILED DESCRIPTION

[0031] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0032] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0033] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0034] In this application, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0035] In this application, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0036] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0037] In addition, the drawings are not drawn to a 1:1 scale, and the relative sizes of the elements in the drawings are drawn only as examples and not necessarily according to the true scale.

[0038] In order to facilitate understanding of the technical solution of the present application, before detailed description, the exhaust manifold in the related art is first explained.

[0039] The internal combustion engine is a heat engine that boasts high thermal efficiency, compact size, light weight, excellent maneuverability, and ease of use. It burns fuel internally and converts the released heat directly into power. The internal combustion engine is the dominant power source in transportation, construction machinery, agricultural machinery, fishing vessels, and defense equipment. It is a highly efficient and widely used power machine today.

[0040] As mentioned in the background technology, the combustion level of an internal combustion engine determines its energy consumption and emission levels. To improve combustion efficiency, the mechanical load and thermal load must increase, which requires the explosion pressure in the cylinder to continue to expand. With the increase of explosion pressure and exhaust temperature, the working environment of the exhaust manifold is becoming more and more harsh. The exhaust manifold is connected to the engine cylinder block and collects the exhaust gas from each cylinder and introduces it into the exhaust manifold with diverging pipes. As one of the important components of the engine assembly system, the exhaust manifold collects the exhaust gas from each cylinder and introduces it into the exhaust manifold. In order to separate the exhaust of each cylinder as much as possible, there is generally one branch for 1-2 cylinders, and each branch is made as long as possible and independently formed to reduce the mutual influence of gases in different pipes.

[0041] As vehicle engine efficiency improves, exhaust temperatures rise to 600-650°C. Furthermore, in recent years, vehicle exhaust emission standards have continued to rise, and the application of catalytic and turbocharging technologies has significantly increased the operating temperature of the exhaust manifold, reaching over 750°C. As engine performance continues to improve, the operating temperature of the exhaust manifold has also increased. Simultaneously, advancements in engine technology have led to more complex exhaust manifold structures. Furthermore, operating under cyclical temperature fluctuations requires exhaust manifold design and materials with excellent high-temperature performance.

[0042] To cope with harsh operating environments, related technologies typically require the installation of a heat shield on the exhaust manifold. However, to meet environmental requirements, internal combustion engines often incorporate features such as exhaust gas recirculation (EGR). EGR returns a small portion of the exhaust gas produced by a diesel or gasoline engine to the cylinders. This significantly limits the space available for the heat shield, making it difficult to optimize exhaust manifold performance within this limited footprint.

[0043] Therefore, it is necessary to provide an exhaust manifold, an internal combustion engine, and a vehicle, which can improve the performance of the exhaust manifold with a simpler structure, thereby meeting work requirements and increasing the service life of the exhaust manifold.

[0044] For ease of description, the drawings only show structures related to the embodiments of the present application.

[0045] Figure 1 FIG. 1 shows a schematic structural diagram of an exhaust manifold 100 in an embodiment of the present application. Figure 2 Shown Figure 1 A top view of the structure shown, Figure 3 Shown Figure 2 AA cross-sectional schematic diagram of the top view shown.

[0046] See Figure 1 and Figure 2 , and combined with Figure 3 An exhaust manifold 100 provided in one embodiment of the present application includes an exhaust manifold body 110, a barrier layer 120, and a heat-resistant layer 130. The barrier layer 120 is disposed on the outer wall of the exhaust manifold body 110, and the heat-resistant layer 130 is disposed on the inner wall of the exhaust manifold body 110. The barrier layer 120 is used to block heat exchange between the interior and exterior of the exhaust manifold body 110, and the heat-resistant layer 130 is made of a heat-resistant material.

[0047] The exhaust manifold 100 provided herein includes at least an exhaust manifold body 110, a barrier layer 120, and a heat-resistant layer 130. The barrier layer 120 and the heat-resistant layer 130 are respectively disposed on the outer and inner walls of the exhaust manifold body 110. The barrier layer 120 blocks heat exchange between the inside and outside of the exhaust manifold 100, thereby reducing heat loss caused by heat diffusion outward from within the exhaust manifold 100 and protecting nearby components of the exhaust manifold 100, such as wiring harnesses, sensors, and other piping.

[0048] Furthermore, the barrier layer 120 replaces the heat shield installed on the exhaust manifold 100 in related art, saving installation space and costs. This not only avoids additional costs but also reduces them. The inside of the exhaust manifold body 110 has the highest operating temperature and most complex operating environment. By providing the heat-resistant layer 130 on the inner wall of the exhaust manifold body 110, the exhaust manifold 100's heat resistance is improved, enabling it to operate in harsh operating environments and extending its service life.

[0049] In some embodiments, the heat-resistant material includes boron nitride. Boron nitride is resistant to high temperatures and can oxidize at high temperatures, forming a viscous liquid or solid-liquid state, with the ability to self-heal cracks. For example, boron nitride can be formed into the heat-resistant layer 130 through processes such as thermal spraying, 3D printing, or powder metallurgy. Furthermore, the heat-resistant material also includes at least one of chromium boride, zirconium boride, and titanium boride. It is understood that the heat-resistant material can be a mixture of boron nitride and a metal boride. For example, the heat-resistant material can be a mixture of boron nitride and chromium boride, a mixture of boron nitride and zirconium boride, or a mixture of boron nitride and titanium boride. The heat-resistant material can also be a mixture of boron nitride, chromium boride, and zirconium boride; a mixture of boron nitride, chromium boride, and titanium boride; or a mixture of boron nitride, zirconium boride, and titanium boride. The heat-resistant material can also be a mixture of boron nitride, chromium boride, zirconium boride, and titanium nitride. It should be noted that the above mixtures do not chemically react to form new composite materials. In this way, the metal in the metal boride can better bond with the exhaust manifold body 110, increasing interlayer bonding strength, thereby further improving the performance of the exhaust manifold 100. Of course, the heat-resistant material may also include other metal borides, which are not limited here.

[0050] In some embodiments, the heat-resistant material includes a metal oxide, and the metal oxide includes at least one of aluminum oxide, titanium dioxide, and chromium oxide. In this way, ceramic materials such as aluminum oxide, titanium dioxide, chromium oxide, or a mixture of the above materials have good high-temperature resistance. It can be understood that the material of the heat-resistant layer 130 can be one of aluminum oxide, titanium dioxide, and chromium oxide, or it can be a mixture of aluminum oxide and titanium dioxide, a mixture of aluminum oxide and chromium oxide, a mixture of titanium dioxide and chromium oxide, or a mixture of the three. It should be noted that the above mixtures will not react chemically to form new composite materials. Of course, the material of the heat-resistant layer 130 can also include other metal oxides, as long as it has good high-temperature resistance.

[0051] Furthermore, the heat-resistant material also includes silicon dioxide. Although the high-temperature resistance of silicon dioxide itself is not as good as that of metal oxides, silicon dioxide has a higher adhesion. The heat-resistant layer 130 formed by mixing silicon dioxide and metal oxide takes into account the high-temperature resistance of metal oxide and the adhesion of silicon dioxide at high temperatures. For example, the metal oxide or its mixture with silicon dioxide can be formed into the heat-resistant layer 130 by processes such as thermal spraying, 3D printing or powder metallurgy. In combination with some of the embodiments described later, if silicon dioxide is not added and only metal oxide is relied upon, it is difficult to achieve the required thickness, resulting in extremely limited high-temperature resistance of the exhaust manifold.

[0052] The inventors have found that in order to improve the adhesion of the heat-resistant layer 130 while meeting the requirements of high-temperature working conditions, in some embodiments, the mass ratio of silicon dioxide to metal oxide is 0.5 to 20. It is understood that the mass ratio can be, but is not limited to, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20. It should be noted that silicon dioxide and metal oxide do not chemically react to form a new composite material. In this embodiment, the mass ratio of silicon dioxide to metal oxide is adjusted to balance the adhesion of silicon dioxide and the high-temperature resistance of the metal oxide.

[0053] Combine Figure 1 and Figure 2 As shown, and see Figure 3 In some embodiments, the exhaust manifold body 110 has an exhaust port 111. The thickness of the heat-resistant layer 130 gradually increases along the inner wall extending toward the exhaust port 111. The thickness of the heat-resistant layer 130 is adjusted based on the actual requirements at the exhaust port 111, with the thickness of the heat-resistant layer 130 increasing closer to the exhaust port 111. Based on this, the inventors considered that if the heat-resistant layer 130 is too thin, the performance improvement of the exhaust manifold 100 provided by the heat-resistant layer 130 will be limited. If the heat-resistant layer 130 is too thick, the heat-resistant layer 130 may peel due to stress concentration, resulting in heat-resistant failure of the heat-resistant layer 130. Therefore, the ratio of the maximum thickness to the minimum thickness is less than or equal to 8. In yet other embodiments, the thickness is between 0.005 mm and 1 mm. It is understood that the thickness may be, but is not limited to, 0.005 mm, 0.01 mm, 0.1 mm, 0.5 mm, or 1 mm.

[0054] In some embodiments, the material of the barrier layer 120 includes a metal oxide, and the metal oxide includes at least one of aluminum oxide, titanium dioxide, and chromium oxide. Thus, ceramic materials such as aluminum oxide, titanium dioxide, and chromium oxide, or mixtures thereof, have excellent high-temperature resistance. It is understood that the material of the barrier layer 120 can be one of aluminum oxide, titanium dioxide, and chromium oxide, or a mixture of aluminum oxide and titanium dioxide, a mixture of aluminum oxide and chromium oxide, a mixture of titanium dioxide and chromium oxide, or a mixture of the three. It should be noted that the above mixtures do not chemically react to form new composite materials. Of course, the material of the barrier layer 120 can also include other metal oxides, as long as they have good high-temperature resistance.

[0055] Furthermore, the barrier layer 120 also includes silicon dioxide. While silicon dioxide itself lacks the high-temperature resistance of metal oxides, it exhibits superior adhesion. The heat-resistant layer 130 formed by mixing silicon dioxide with metal oxides combines the high-temperature resistance of metal oxides with the adhesion of silicon dioxide at high temperatures. For example, the metal oxide or its mixture with silicon dioxide can be formed into the barrier layer 120 via processes such as thermal spraying, 3D printing, or powder metallurgy.

[0056] The inventors have discovered that, in order to improve the adhesion of the barrier layer 120 while meeting high-temperature operating conditions, in some embodiments, the mass ratio of silicon dioxide to metal oxide is 0.01 to 10. It is understood that the mass ratio may be, but is not limited to, 0.01, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. It should be noted that silicon dioxide and metal oxide do not chemically react to form a new composite material. In this embodiment, the mass ratio of silicon dioxide to metal oxide is adjusted to balance the adhesion of silicon dioxide with the high-temperature resistance of the metal oxide.

[0057] Based on the same inventive concept, another aspect of the present application further provides an internal combustion engine, including the exhaust manifold 100 described above. By using the exhaust manifold 100 described above, which has better heat resistance and a longer service life, the thermal efficiency of the internal combustion engine is improved, fuel consumption is reduced, and carbon emissions are reduced. The probability of internal combustion engine failure is also greatly reduced, thereby extending the service life of the internal combustion engine.

[0058] Based on the same inventive concept, another aspect of the present application further provides a vehicle comprising the above-mentioned internal combustion engine. Thus, by using the above-mentioned internal combustion engine, the performance of the vehicle is also improved.

[0059] Combine Figures 1 to 3As shown, the exhaust manifold 100 provided in the present application comprises at least an exhaust manifold body 110, a barrier layer 120, and a heat-resistant layer 130. The barrier layer 120 and the heat-resistant layer 130 are respectively disposed on the outer and inner walls of the exhaust manifold body 110. The barrier layer 120 blocks heat exchange between the inside and outside of the exhaust manifold 100, thereby reducing heat loss caused by heat diffusion outward from within the exhaust manifold 100 and protecting nearby components of the exhaust manifold 100, such as wiring harnesses, sensors, and other piping. Furthermore, the barrier layer 120 can replace the heat shield of the exhaust manifold 100 in related art, saving installation space and costs. The inner side of the exhaust manifold body 110 has the highest operating temperature and the most complex working environment. By providing a heat-resistant layer 130 on the inner wall of the exhaust manifold body 110, the heat-resistant layer 130 can be used to improve the heat resistance of the exhaust manifold 100, thereby enabling it to work in harsh working environments and also increasing the service life of the exhaust manifold 100.

[0060] In some embodiments, the heat-resistant material includes boron nitride. Boron nitride has the characteristic of high temperature resistance, and boron nitride can be oxidized at high temperature, in a viscous liquid or solid-liquid state, and has the ability to self-heal cracks. The heat-resistant material also includes metal borides, and the metal in the metal boride can better bond with the exhaust manifold body 110, thereby improving the interlayer bonding force, thereby further improving the performance of the exhaust manifold 100. In other embodiments, the heat-resistant material may include metal oxides, ceramic materials such as aluminum oxide, titanium dioxide, chromium oxide, or a mixture of the above materials, so that the heat-resistant layer 130 has better high-temperature resistance. Metal oxides can also be mixed with silicon dioxide, so that the heat-resistant layer 130 has both the high-temperature resistance of metal oxides and the adhesion of silicon dioxide.

[0061] Considering that the thickness of the heat-resistant layer 130 cannot be too thick or too thin, in order to meet the performance requirements while reducing the possibility of the heat-resistant layer 130 peeling off due to stress concentration, resulting in heat-resistant failure of the heat-resistant layer 130, the present application sets the thickness of the heat-resistant layer 130 so that the ratio of the maximum thickness to the minimum thickness is less than or equal to 8, and the thickness is 0.005 mm to 1 mm.

[0062] Barrier layer 120 is made of metal oxides, ceramic materials such as aluminum oxide, titanium dioxide, chromium oxide, or mixtures thereof, and exhibits excellent high-temperature resistance. It can also include silicon dioxide to enhance its adhesion. To ensure high-temperature operation while maintaining high adhesion, the mass ratio of silicon dioxide to metal oxide is between 0.01 and 10.

[0063] The internal combustion engine and vehicle provided in the present application, due to the use of the above-mentioned exhaust manifold 100 with better heat resistance and longer service life, improve the thermal efficiency of the internal combustion engine, reduce fuel consumption and achieve green carbon reduction. At the same time, the probability of failure of the internal combustion engine is greatly reduced, thereby increasing the service life of the internal combustion engine and improving the performance of the vehicle.

[0064] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0065] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. An exhaust manifold, characterized in that: include: exhaust manifold body; a barrier layer, provided on an outer wall of the exhaust manifold body; and a heat-resistant layer provided on the inner wall of the exhaust manifold body; Wherein, the barrier layer is used to block the heat exchange between the inside and outside of the exhaust manifold body, and the heat-resistant layer is made of a heat-resistant material; The exhaust manifold body has an exhaust port; The thickness of the heat-resistant layer gradually increases along the extension direction toward the exhaust port on the inner wall; the ratio of the maximum value of the thickness to the minimum value of the thickness is less than or equal to 8, and the thickness is 0.005 mm to 1 mm.

2. The exhaust manifold according to claim 1, characterized in that The heat-resistant material includes boron nitride.

3. The exhaust manifold according to claim 2, characterized in that The heat-resistant material further includes at least one of chromium boride, zirconium boride, and titanium boride.

4. The exhaust manifold according to claim 1, characterized in that The heat-resistant material includes a metal oxide; The metal oxide includes at least one of aluminum oxide, titanium dioxide, and chromium oxide.

5. The exhaust manifold according to claim 4, characterized in that The heat-resistant material further comprises silicon dioxide.

6. The exhaust manifold according to claim 5, characterized in that The mass ratio of the silicon dioxide to the metal oxide is 0.5 to 20.

7. The exhaust manifold according to any one of claims 1 to 6, characterized in that: The material of the barrier layer includes metal oxide; The metal oxide includes at least one of aluminum oxide, titanium dioxide, and chromium oxide.

8. The exhaust manifold according to claim 7, characterized in that The material of the barrier layer further includes silicon dioxide.

9. The exhaust manifold according to claim 8, characterized in that The mass ratio of the silicon dioxide to the metal oxide is 0.01 to 10.

10. An internal combustion engine, characterized in that: Comprising the exhaust manifold according to any one of claims 1-9.

11. A vehicle, characterized in that: Comprising the internal combustion engine of claim 10.

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