Exhaust manifold seal structure and exhaust manifold having the seal structure

Abstract

This application relates to an exhaust manifold sealing structure and an exhaust manifold with a sealing structure. The exhaust manifold sealing structure includes a sealing flange, a sealing ring, a heat-resistant ring, and an expansion-suppressing ring. The sealing flange is connected to the end face of the exhaust manifold and has a flange boss. The upper end face of the sealing ring abuts against the engine cylinder head, and the lower end face abuts against the top surface of the flange boss. The outer side of the heat-resistant ring is fitted onto the inner side of the flange boss, and the inner side of the expansion-suppressing ring is fitted onto the outer side of the flange boss. The heat-resistant ring prevents high-temperature exhaust from directly eroding the sealing flange and sealing ring. The heat-resistant ring and the expansion-suppressing ring, respectively, cooperate from the inner and outer sides of the flange boss to suppress the lateral slippage and deformation of the sealing flange. The exhaust manifold sealing structure does not require changes to the engine cylinder head structure; only the heat-resistant ring and expansion-suppressing ring need to be added to the original exhaust manifold sealing flange. The sealing ring can still use ordinary materials to ensure that the exhaust manifold sealing structure still has good sealing performance under high-temperature exhaust conditions.

Description

Technical Field

[0001] This application relates to the field of sealing structure technology between automobile engines and exhaust manifolds, and in particular to exhaust manifold sealing structures and exhaust manifolds with sealing structures. Background Technology

[0002] With advancements in engine technology, fuel consumption and displacement have continuously decreased to meet emission regulations. However, this reduction in fuel consumption and displacement has led to increasingly higher exhaust temperatures. These elevated temperatures exacerbate deformation of the exhaust manifold's sealing flanges and degrade the sealing performance of gaskets at high temperatures. This results in the exhaust manifold and cylinder head seals losing their seal, causing leaks that affect vehicle operation. Traditional solutions involve improving the high-temperature resistance and deformation resistance of the exhaust manifold flanges and gaskets by using expensive nickel-containing high-temperature cast iron materials to reduce flange deformation at high temperatures and maintain gasket elasticity. However, these traditional solutions increase engine costs, hindering mass production, and require replacing the entire exhaust manifold sealing structure with new materials, rendering them ineffective for older materials.

[0003] Patent document (CN109281745A) discloses a heat-insulating and energy-concentrating sleeve structure between the exhaust manifold and the cylinder head. The heat-insulating and energy-concentrating sleeve is threadedly installed in the exhaust passage of the cylinder head and arranged between the high-temperature combustion gas and the exhaust manifold gasket, which reduces the working temperature of the exhaust manifold gasket and prevents the exhaust manifold gasket from being directly eroded by the high-temperature exhaust gas. However, there is a gap between the heat-insulating and energy-concentrating sleeve and the cylinder head. The high-temperature gas contacts the exhaust manifold gasket through the gap, which affects the heat insulation effect of the heat-insulating and energy-concentrating sleeve on the exhaust manifold gasket.

[0004] Patent document (CN208153180U) discloses a sealing structure between an engine cylinder head and an exhaust manifold. The exhaust manifold and the cylinder head flange are both provided with U-shaped grooves for installing flexible rings. The seal is achieved by the pressure between the flexible ring and the U-shaped groove. However, this structure is only suitable for normal temperatures. Under high-temperature exhaust conditions, the flexible ring and the U-shaped groove are directly eroded by the high-temperature exhaust, resulting in a sharp decline in material properties and a deterioration in the sealing effect.

[0005] Patent document (CN 210234652 U) discloses an exhaust manifold reinforcement structure that prevents deformation at high temperatures by setting a tension plate. The tension plate can reduce the degree of thermal deformation of the exhaust manifold flange, but it aggravates the internal stress of the exhaust manifold, which can easily lead to cracking of the exhaust manifold. In addition, the exhaust manifold gasket is still directly eroded by the high temperature exhaust, and the seal is prone to failure at high temperature. Summary of the Invention

[0006] Therefore, it is necessary to provide an exhaust manifold sealing structure and an exhaust manifold with a sealing structure to address the problem that the exhaust manifold sealing structure is prone to deformation and sealing failure under high-temperature exhaust conditions.

[0007] An exhaust manifold sealing structure is provided for a sealing connection between the end face of the exhaust manifold and the end face of the cylinder head cover of an engine, the exhaust manifold sealing structure comprising:

[0008] A sealing flange is connected to the end face of the exhaust manifold, and a flange boss is provided on the flange face of the sealing flange facing away from the exhaust manifold.

[0009] A sealing ring, the upper end face of which abuts against the end face of the cover of the engine cylinder head, and the lower end face of which abuts against the top surface of the flange boss.

[0010] A heat-resistant ring, the outer side of which is fitted onto the inner side of the flange boss;

[0011] An anti-swell ring is provided, with its inner side fitted onto the outer side of the flange boss.

[0012] In one embodiment, the height of the inner side of the flange boss is equal to the height of the outer side of the flange boss, and both the inner and outer sides of the flange boss are perpendicular to the top surface of the flange boss; the height of the outer side of the heat-resistant ring is greater than the height of the inner side of the flange boss, and the height of the outer side of the heat-resistant ring is less than the sum of the height of the inner side of the flange boss and the height of the sealing ring.

[0013] In one embodiment, the height of the inner side of the expansion-suppressing ring is greater than the height of the outer side of the flange boss, and the height of the inner side of the expansion-suppressing ring is less than the height of the outer side of the heat-insulating ring.

[0014] In one embodiment, the shortest distance between the tangent on the outer side of the sealing ring and the tangent on the inner side of the sealing ring is the width of the sealing ring; the shortest distance between the tangent on the outer side of the flange boss and the tangent on the inner side of the flange boss is the width of the top surface of the flange boss; the width of the sealing ring is smaller than the width of the top surface of the flange boss; the outer side of the heat-insulating ring does not abut against the inner side of the sealing ring, and the inner side of the expansion-suppressing ring abuts against the outer side of the sealing ring.

[0015] In one embodiment, the inner diameter of the heat-resistant ring is larger than the diameter of the cross-section of the exhaust manifold cavity.

[0016] In one embodiment, the sealing ring includes at least two layers of stacked sealing gaskets, the sealing gaskets having sealing ribs formed thereon, the sealing ribs being flanges stamped out of the body of the sealing gaskets.

[0017] In one embodiment, a first mounting groove is provided on the inner side of the flange boss, and the outer side of the heat-insulating ring is interference-fitted to the inner side of the flange boss through the first mounting groove; and / or a second mounting groove is provided on the outer side of the flange boss, and the inner side of the expansion-suppressing ring is interference-fitted to the outer side of the flange boss through the second mounting groove.

[0018] In one embodiment, the exhaust manifold sealing structure further includes a fastener that secures the exhaust manifold sealing structure between the end face of the exhaust manifold and the end face of the engine cylinder head.

[0019] In one embodiment, at least one of the following is also included:

[0020] The heat-resistant ring is made of a high-temperature alloy material;

[0021] The expansion-suppressing ring is made of Kovar alloy.

[0022] This application also proposes an exhaust manifold with a sealing structure, the exhaust manifold with the sealing structure comprising:

[0023] Exhaust manifold; and,

[0024] The exhaust manifold sealing structure described above.

[0025] In this application's technical solution, the exhaust manifold sealing structure is positioned between the exhaust manifold's port end face and the engine cylinder head's cover end face. High-temperature exhaust gas exits from the engine cylinder head's cover end face and enters the exhaust manifold through the exhaust manifold's port end face. Therefore, the high-temperature exhaust gas will erode the sealing flange and sealing ring of the exhaust manifold sealing structure. A heat-resistant ring is installed inside the sealing ring. When high-temperature exhaust gas enters the exhaust manifold, it first contacts the heat-resistant ring. The heat-resistant ring has a low thermal conductivity, preventing the high-temperature exhaust gas from directly eroding the sealing flange and sealing ring, reducing the elastic decay of the sealing ring under high-temperature conditions, and effectively maintaining the sealing elasticity of the sealing ring. The heat-resistant ring also reduces the flange surface temperature of the sealing flange, reducing the longitudinal thermal deformation of the sealing flange and preventing exhaust leakage caused by insufficient compensation of the sealing ring due to excessive deformation at high temperatures. The heat-insulating ring and the expansion-suppressing ring cooperate from the inner and outer sides of the flange boss to suppress the lateral sliding deformation of the sealing flange, reduce the frictional damage to the sealing ribs of the sealing ring caused by the micro-movement of the sealing flange, and ensure that the exhaust manifold sealing structure always has sufficient sealing pressure and reliable sealing performance under high-temperature exhaust conditions.

[0026] The exhaust manifold sealing structure does not require changes to the engine cylinder head structure. It only requires the installation of a heat-insulating ring and an expansion-suppressing ring on the original exhaust manifold sealing flange. The sealing ring can still be made of ordinary materials to ensure that the exhaust manifold sealing structure still has good sealing performance under high-temperature exhaust conditions. Attached Figure Description

[0027] Figure 1 This is an exploded structural diagram of an embodiment of the exhaust manifold sealing structure and an exhaust manifold having the sealing structure of this application.

[0028] Figure 2 This is a cross-sectional view of an embodiment of the exhaust manifold sealing structure and an exhaust manifold having the sealing structure of this application.

[0029] Figure 3 for Figure 2 A magnified schematic diagram of the structure at point A in the middle.

[0030] Figure 4 for Figure 3 A cross-sectional view of the C-shaped sealing ring.

[0031] Figure 5 This is a combined structural schematic diagram of a top view (a), a side view (b), and a cross-sectional view (c) of an embodiment of the exhaust manifold sealing structure and an exhaust manifold with a sealing structure according to this application.

[0032] Figure 6 This is a combined structural schematic diagram of an isometric view (d) and a top view (e) of an embodiment of the exhaust manifold sealing structure and an exhaust manifold having a sealing structure according to the present application.

[0033] Figure 7 This is a cross-sectional schematic diagram of the heat-insulating ring of an embodiment of the exhaust manifold sealing structure and an exhaust manifold having the sealing structure of this application.

[0034] Figure 8 This is a combined structural schematic diagram of a cross-sectional view (f) and a top view (g) of an embodiment of the exhaust manifold sealing structure and an exhaust manifold having a sealing structure according to the present application.

[0035] Explanation of component labels in the attached diagram:

[0036] 1000. Exhaust manifold sealing structure; 100. Sealing flange; 110. Flange boss; 111. Top surface of flange boss; 112. Inner side of flange boss; 113. Outer side of flange boss; 200. Sealing ring; 210. Sealing gasket; 211. Inner side of sealing ring; 212. Outer side of sealing ring; 300. Heat-resistant ring; 300a. C-shaped heat-resistant ring; 310. Inner side of heat-resistant ring; 320. Outer side of heat-resistant ring; 400. Expansion-suppressing ring; 410. Inner side of expansion-suppressing ring; 420. Outer side of expansion-suppressing ring; 500. Fastener; 600. Exhaust manifold; 610. Cross-section of exhaust manifold inner cavity; 700. Engine cylinder head; 2000. Exhaust manifold with sealing structure. Detailed Implementation

[0037] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0038] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0039] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0040] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0041] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0042] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0043] See Figures 1 to 4 , Figure 1 and Figure 2 Exploded structural schematic diagram and cross-sectional structural schematic diagram of an embodiment of the exhaust manifold sealing structure 1000 and the exhaust manifold 2000 having the sealing structure of this application are shown respectively. Figure 3 It shows Figure 2 A magnified schematic diagram of the structure at point A in the middle. Figure 4 It shows Figure 3The heat-resistant ring 300 is a cross-sectional view of a C-shaped heat-resistant ring 300a. This application proposes an exhaust manifold sealing structure 1000 for sealing the connection between the end face of the exhaust manifold 600 and the end face of the engine cylinder head 700. The exhaust manifold sealing structure 1000 includes a sealing flange 100, a sealing ring 200, a heat-resistant ring 300, and an expansion-damping ring 400. The sealing flange 100 is connected to the end face of the exhaust manifold 600, and a flange boss 110 is provided on the flange surface of the sealing flange 100 facing away from the exhaust manifold 600.

[0044] See Figures 5 to 8 , Figure 5 The diagram shows a combined structural schematic of a top view (a), a side view (b), and a cross-sectional view (c) of an embodiment of the exhaust manifold sealing structure 1000 and an exhaust manifold 2000 having the sealing structure of this application, including an expansion-suppressing ring 400. Figure 6 A schematic diagram of the combined structure of the sealing ring 200 is shown in the isometric view (d) and top view (e). Figure 7 A cross-sectional view of the heat-insulating ring 300 is shown. Figure 8 A schematic diagram of the combined structure of the sealing flange 100 is shown in cross-sectional view (f) and top view (g). The upper end face of the sealing ring 200 abuts against the end face of the cylinder head 700, and the lower end face of the sealing ring 200 abuts against the top surface 111 of the flange boss. The outer side 320 of the heat-insulating ring is fitted onto the inner side 112 of the flange boss. The inner side 410 of the expansion-suppressing ring is fitted onto the outer side 113 of the flange boss. The cross-sectional shapes of the sealing ring 200, the heat-insulating ring 300, and the expansion-suppressing ring 400 match the shape of the end face of the exhaust manifold 600 and the end face of the cylinder head 700, and can be circular, elliptical, or other shapes, without specific limitation here. For example, the cross-sectional shape of the sealing ring 200, the heat-insulating ring 300, and the expansion-suppressing ring 400 is circular.

[0045] With this configuration, the exhaust manifold sealing structure 1000 is located between the pipe end face of the exhaust manifold 600 and the cover end face of the engine cylinder head 700. High-temperature exhaust gas is discharged from the cover end face of the engine cylinder head 700 and enters the exhaust manifold 600 through the pipe end face of the exhaust manifold 600. Therefore, the high-temperature exhaust gas will erode the sealing flange 100 and sealing ring 200 of the exhaust manifold sealing structure 1000. A heat-resistant ring 300 is installed inside the sealing ring 200. When high-temperature exhaust gas enters the exhaust manifold 600, it first contacts the heat-resistant ring 300. The heat-resistant ring 300 has a low thermal conductivity, preventing the high-temperature exhaust gas from directly eroding the sealing flange 100 and the sealing ring 200, reducing the elastic decay of the sealing ring 200 under high-temperature conditions, and effectively maintaining the sealing elasticity of the sealing ring 200. The heat-resistant ring 300 also reduces the flange surface temperature of the sealing flange 100, reducing the longitudinal thermal deformation of the sealing flange 100, and preventing exhaust leakage caused by insufficient compensation of the sealing ring 200 due to excessive deformation at high temperatures. The heat-resistant ring 300 and the expansion-suppressing ring 400 cooperate from the inner side 112 and outer side 113 of the flange boss, respectively, to suppress the lateral sliding deformation of the sealing flange 100, reducing the frictional damage to the sealing ribs of the sealing ring 200 caused by the slight movement of the sealing flange 100, so as to ensure that the exhaust manifold sealing structure 1000 always has sufficient sealing pressure and reliable sealing performance under high-temperature exhaust conditions.

[0046] The exhaust manifold sealing structure 1000 does not require any changes to the engine cylinder head 700 structure. It only requires the installation of a heat-insulating ring 300 and an expansion-suppressing ring 400 on the original exhaust manifold 600 sealing flange 100. The sealing ring 200 can still use ordinary materials to ensure that the exhaust manifold sealing structure 1000 still has good sealing performance under high-temperature exhaust conditions.

[0047] See Figure 3 , Figure 7 and Figure 8The height of the inner side 112 of the flange boss is equal to the height of the outer side 113 of the flange boss, and both the inner side 112 and the outer side 113 of the flange boss are perpendicular to the top surface 111 of the flange boss. The height of the outer side 320 of the heat-resistant ring is greater than the height of the inner side 112 of the flange boss. This design serves two purposes: firstly, the heat-resistant ring 300 can provide heat insulation for the inner side 112 of the flange boss, preventing the flange boss 110 from expanding and deforming inwards due to heat; secondly, the portion of the outer side 320 of the heat-resistant ring that extends beyond the inner side 112 of the flange boss can provide heat insulation for the sealing ring 200 located on the top surface 111 of the flange boss, preventing the sealing ring 200 from being damaged by high-temperature exhaust erosion. The height of the outer side 320 of the heat-resistant ring is less than the sum of the height of the inner side 112 of the flange boss and the height of the sealing ring 200. This design ensures that the sealing ring 200 has a certain elastic range during installation and tightening, preventing the outer side 320 of the heat-insulating ring from being too high and abutting against the engine cylinder head 700 and fixing the distance between it and the top surface 111 of the flange boss, thus preventing the sealing ring 200 from reaching the sealing and tightening state. This ensures that the heat-insulating effect is optimal while the sealing ring 200 is tightened.

[0048] See Figures 3 to 8 The height of the inner surface 410 of the expansion-suppressing ring is greater than the height of the outer surface 113 of the flange boss, while the height of the inner surface 410 of the expansion-suppressing ring is less than the height of the outer surface 320 of the heat-insulating ring. The shortest distance between the tangent of the outer surface 212 of the sealing ring and the tangent of the inner surface 211 of the sealing ring is the width of the sealing ring 200. The shortest distance between the tangent of the outer surface 113 of the flange boss and the tangent of the inner surface 112 of the flange boss is the width of the top surface 111 of the flange boss. The width of the sealing ring 200 is less than the width of the top surface 111 of the flange boss. The outer surface 320 of the heat-insulating ring does not abut against the inner surface 211 of the sealing ring, while the inner surface 410 of the expansion-suppressing ring abuts against the outer surface 212 of the sealing ring. With this configuration, the width of the sealing ring 200 is smaller than the width of the flange boss top surface 111, ensuring that the inner side 211 of the sealing ring does not abut against the outer side 320 of the heat-insulating ring, while the outer side 212 of the sealing ring abuts against the inner side 410 of the expansion-suppressing ring. The expansion-suppressing ring 400 provides precise circumferential positioning for the sealing ring 200 and prevents installation difficulties caused by over-positioning on the side of the heat-insulating ring 300. The inner side 410 of the expansion-suppressing ring abuts against the sealing ring 200, and a gap remains between the upper end face of the expansion-suppressing ring 400 and the engine cylinder head 700. Heat on the sealing ring 200 can be quickly dissipated through heat transfer with the expansion-suppressing ring 400, and external air flows rapidly through the gap between the expansion-suppressing ring 400 and the engine cylinder head 700 to promptly remove heat from the sealing ring 200 and the flange boss 110, further reducing the working temperature of the workpiece.

[0049] Preferably, the inner diameter of the heat-resistant ring 300 is larger than the diameter of the cross-section 610 of the exhaust manifold. With this configuration, the inner surface 310 of the heat-resistant ring will not protrude from the end face of the exhaust manifold 600. When the high-temperature exhaust passes through the exhaust manifold sealing structure 1000, the heat-resistant ring 300 will not throttle the high-temperature exhaust, which helps to reduce the resistance of the high-temperature exhaust.

[0050] The sealing ring 200 can be configured as a single-layer gasket, a multi-layer gasket, or a C-shaped gasket, etc., and is not specifically limited here. For example, the sealing ring 200 includes at least two stacked sealing gaskets 210, each gasket 210 having a sealing rib formed therefrom, which is a flange stamped onto the body of the sealing gasket 210. Compared to traditional bolt-hole positioning sealing gaskets, this eliminates the need for bolt fixing, and the short heat transfer distance between the stamped sealing rib and the surrounding air facilitates the dissipation of heat from the sealing gasket 210.

[0051] Specifically, a first mounting groove is formed on the inner side 112 of the flange boss, and the outer side 320 of the heat-insulating ring is interference-fitted to the inner side 112 of the flange boss through the first mounting groove to suppress the flange boss 110 from expanding and deforming inward when heated. And / or a second mounting groove is formed on the outer side 113 of the flange boss, and the inner side 410 of the expansion-suppressing ring is interference-fitted to the outer side 113 of the flange boss through the second mounting groove to suppress the flange boss 110 from expanding and deforming outward when heated. The height of the first mounting groove is less than the height of the outer side 320 of the heat-insulating ring, and the height of the second mounting groove is less than the height of the inner side 410 of the expansion-suppressing ring. This arrangement ensures that the heat-insulating ring 300 and the expansion-suppressing ring 400 will not detach from the first and second mounting grooves during installation, facilitating installation and ensuring the fixed stability of the heat-insulating ring 300 and the expansion-suppressing ring 400. The first and second mounting grooves can be machined onto the inner side 112 and the outer side 113 of the flange boss, simplifying the machining process.

[0052] Specifically, see Figure 1 The exhaust manifold sealing structure 1000 also includes a fastener 500, which secures the exhaust manifold sealing structure 1000 between the end face of the exhaust manifold 600 and the end face of the cylinder head 700. For example, the fastener 500 is a bolt.

[0053] The heat-resistant ring 300 is made of a high-temperature alloy. For example, the heat-resistant ring 300 is made of GH4169 material, which has good high-temperature resistance and fatigue resistance. The expansion-suppressing ring 400 is made of Kovar alloy.

[0054] See Figure 3 and Figure 4 The cross-section of the heat-insulating ring 300 can be rectangular, C-shaped, or other shapes; no specific limitation is made here. For example, see [link to relevant documentation]. Figure 3The cross-section of the heat-insulating ring 300 is set to rectangular, see reference. Figure 4 The heat-resistant ring 300 is a C-shaped heat-resistant ring 300a, which plays a certain auxiliary sealing role. The heat-resistant ring 300 can be integrated into the engine cylinder head 700, exhaust manifold 600 or sealing ring 200, and no specific limitation is made here.

[0055] This application also proposes an exhaust manifold 2000 with a sealing structure, which includes an exhaust manifold 600 and the aforementioned exhaust manifold sealing structure 1000.

[0056] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above 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.

[0057] The embodiments described above are merely illustrative of several implementation methods of this application, and 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 those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. An exhaust manifold sealing structure for sealing connection between a port end surface of an exhaust manifold and a cover end surface of an engine cylinder head, characterized by, The exhaust manifold sealing structure includes: A sealing flange is connected to the end face of the exhaust manifold, and a flange boss is provided on the flange face of the sealing flange facing away from the exhaust manifold. A sealing ring, the upper end face of which abuts against the end face of the cover of the engine cylinder head, and the lower end face of which abuts against the top surface of the flange boss. A heat-resistant ring, the outer side of which is fitted onto the inner side of the flange boss; An anti-expansion ring, wherein the inner side of the anti-expansion ring is fitted to the outer side of the flange boss; The height of the inner side of the flange boss is equal to the height of the outer side of the flange boss, and both the inner and outer sides of the flange boss are perpendicular to the top surface of the flange boss; the height of the outer side of the heat-resistant ring is greater than the height of the inner side of the flange boss, and the height of the outer side of the heat-resistant ring is less than the sum of the height of the inner side of the flange boss and the height of the sealing ring. The height of the inner side of the expansion-suppressing ring is greater than the height of the outer side of the flange boss, and the height of the inner side of the expansion-suppressing ring is less than the height of the outer side of the heat-insulating ring.

2. The exhaust manifold seal structure according to claim 1, characterized by, The shortest distance between the tangent on the outer side of the sealing ring and the tangent on the inner side of the sealing ring is the width of the sealing ring. The shortest distance between the tangent on the outer side of the flange boss and the tangent on the inner side of the flange boss is the width of the top surface of the flange boss. The width of the sealing ring is smaller than the width of the top surface of the flange boss. The outer side of the heat-insulating ring does not abut against the inner side of the sealing ring, while the inner side of the expansion-suppressing ring abuts against the outer side of the sealing ring.

3. The exhaust manifold seal structure of claim 1, wherein The inner diameter of the heat-insulating ring is larger than the diameter of the cross-section of the exhaust manifold.

4. The exhaust manifold seal structure according to claim 1, characterized by, The sealing ring includes at least two layers of stacked sealing gaskets, each gasket having a sealing rib formed thereon, the sealing rib being a flange stamped out of the body of the sealing gasket.

5. The exhaust manifold seal structure of claim 1, wherein The flange boss has a first mounting groove on its inner side, and the heat-insulating ring has its outer side pressed against the flange boss through the first mounting groove; and / or the flange boss has a second mounting groove on its outer side, and the expansion-suppressing ring has its inner side pressed against the flange boss through the second mounting groove.

6. The exhaust manifold seal structure of claim 1, wherein The exhaust manifold sealing structure also includes fasteners that fix and press the exhaust manifold sealing structure between the pipe end face of the exhaust manifold and the cover end face of the engine cylinder head.

7. The exhaust manifold sealing structure according to claim 1, characterized in that, It also includes at least one of the following: The heat-resistant ring is made of a high-temperature alloy material; The expansion-suppressing ring is made of Kovar alloy.

8. An exhaust manifold with a sealing structure, characterized in that, The exhaust manifold with a sealed structure includes: Exhaust manifold; and, The exhaust manifold sealing structure as described in any one of claims 1-7.

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