Self-tightening metal sealing ring

Abstract

The utility model discloses a self-tightening type metal sealing ring which comprises a metal sealing ring body, the metal sealing ring body is a hollow metal circular ring, and a lip opening which is opened axially is arranged on the end face of the circular ring of the metal sealing ring body in the circumferential direction. Therefore, the metal sealing ring body forms a circular annular elastic body with an axial opening lip in the circumferential direction of the end face. The utility model has the advantages of reasonable design, simple structure, long service life, convenience in installation, low cost, good sealing performance, strong leak-proof capability, easiness in realizing upper and lower die splitting stamping and simple spinning forming, can be repeatedly used, and is not easy to deform; the elastic metal sealing ring is particularly suitable for a sealing system of a segmented exhaust manifold of a diesel engine which is compact in sealing structure size, limited in strength and not rich in pre-tightening force, is a novel elastic metal sealing ring, can effectively solve the sealing problems of high temperature resistance and high pressure resistance of a fluid sealing system, and has extremely high practicability and popularization significance.

Description

Technical Field

[0001] The utility model relates to the technical field of sealing, in particular to a self-tightening metal sealing ring. Background Art

[0002] As we all know, the exhaust sealing ring is an important sealing component connecting the exhaust manifold in the engine exhaust system. With the upgrade of engine emissions, the exhaust temperature and exhaust back pressure of the exhaust manifold continue to increase. The traditional exhaust manifold uses a maze-type sealing method that combines multiple ring grooves and radial sealing rings. It is easy to leak at the connection. Slight leakage will affect the cylinder head and surrounding accessories. When the leakage is serious, the engine power and torque will be reduced, affecting the engine performance and reliability. Utility Model Content

[0003] The utility model aims to solve the shortcomings in the prior art and proposes a self-tightening metal sealing ring.

[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0005] A self-tightening metal sealing ring comprises a metal sealing ring body, wherein the metal sealing ring body is a hollow metal circular ring, and an axially opened lip is arranged on the circumference of the end surface of the circular ring of the metal sealing ring body, so that the metal sealing ring body constitutes a circular annular elastic body with an axially opened lip on the circumference of the end surface; the cross section of the metal sealing ring body is an integrated structure formed by an inner sealing lip component, a connecting component, and an outer sealing lip component connected in sequence through smooth transition; the cross section of the connecting component is a semicircular arc; the metal sealing ring body is an interference fit with the shaft and hole to be sealed.

[0006] Further, the cross-sectional shape of the inner sealing lip component is an arc shape, and the cross-sectional shape of the outer sealing lip component includes a straight line segment and an arc portion.

[0007] Furthermore, the arc on the cross section of the inner sealing lip component and the arc on the cross section of the outer sealing lip component are both arcs with a central angle not greater than π / 6 radians; the arc on the cross section of the inner sealing lip component and the semicircular arc on the cross section of the connecting component are concentric arcs with equal radius; one end point of the arc on the cross section of the inner sealing lip component is the inner end point (A) of the semicircular arc of the connecting component, and the other end point of the arc-shaped cross section of the inner sealing lip component is the second opening lip terminal end point (E); one end of the straight line segment is tangent to the semicircular arc on the cross section of the connecting component, and the point of tangency is the outer end point (B) of the semicircular arc of the connecting component; the end of the straight line segment away from the connecting component is tangent to the arc on the cross section of the outer sealing lip component, and the point of tangency is the end point (C) of the straight line segment; the end point of the outer sealing lip component away from the connecting component is the first opening lip terminal end point (D).

[0008] Furthermore, the length of the straight line segment is not greater than 2π / 3 times the radius of the semicircular arc on the cross section of the connecting part; the sum of the length of the cross section of the inner sealing lip part and the length of the cross section of the outer sealing lip part is equal to the length of the cross section of the connecting part; the arc on the cross section of the inner sealing lip part and the arc on the cross section of the outer sealing lip part are the inward-turned parts of the lip opening axially opened in the circumferential direction of the end face of the circular ring of the metal sealing ring body, respectively.

[0009] Furthermore, the metal sealing ring body is made of a precipitation-strengthened nickel-based high-temperature alloy steel strip in a solid solution and aging state.

[0010] Furthermore, the surface of the metal sealing ring body is treated with an aluminum chromium nitride (Al CrN) coating.

[0011] The utility model technology has the following beneficial effects:

[0012] First of all, the metal sealing ring body is a sealing ring with self-tightening sealing characteristics. Since the lip opening axially opened on the inner sealing lip component and the outer sealing lip component toward the end surface circumference of the circular ring of the metal sealing ring body is turned inward, the open end of the circular ring of the metal sealing ring body on the circumference of the end surface is not constrained. With the increase of system pressure and temperature, the lip opening arranged on the circumference of the axial end surface of the circular ring of the metal sealing ring body opens radially under the action of the exhaust gas pressure inside the system, compensating for the sealing pressure reduction caused by the deformation and separation of the front exhaust manifold and the rear exhaust manifold caused by temperature and pressure fluctuations and the relaxation of the metal sealing ring body, it plays a role in automatically adjusting the sealing system under thermal expansion and cold contraction working conditions. The sealing effect greatly improves the sealing performance of the system; at the same time, the sealing surface of the inner sealing lip component is an arc with a central angle of no more than π / 6 radians. Under the same elastic pressure, the arc-shaped sealing surface will produce a large elastic deformation, thereby increasing the microscopic unevenness on the sealing surface to form an effective close contact and fit, filling the microscopic grooves to achieve the initial sealing of the sealing surface, thereby effectively preventing the high-temperature exhaust gas from leaking from the connection; furthermore, the outer sealing lip component and the inner sealing lip component of the metal sealing ring body are interference fits with the holes and shafts to be sealed, thereby producing elastic deformation and storing elastic potential energy. When the pressure is unloaded or reduced, the stored elastic potential energy is released, a certain degree of rebound occurs, the deformation is reduced, and the normal sealing working state is entered.

[0013] Secondly, one end of the straight line segment on the outer sealing lip component of the metal sealing ring body is tangent to the semicircular arc on the connecting component, and the other end of the straight line segment on the outer sealing lip component is tangent to the arc with a central angle of no more than π / 6 radians on the outer sealing lip component. In this way, the connection between the two ends of the straight line segment on the outer sealing lip component and the semicircular arc on the connecting component and the arc with a central angle of no more than π / 6 radians on the outer sealing lip component at the corners is smoothly connected through arc transition. In this way, the metal sealing ring body can not only prevent the generation of fragile surfaces at the corners, but also reduce stress concentration, and avoid the generation of stamping or spinning cracks. When the wall thickness of the stamped or spun parts cannot be completely uniform, the connection between the thick wall and the thin wall adopts an arc transition connection form, which can avoid the stress concentration caused by the sudden increase of local stress due to the sudden change of wall thickness, thereby stabilizing the design size of the metal sealing ring body and enhancing the sealing effect of the metal sealing ring body. At the same time, since the length of the inner sealing lip component of the metal sealing ring body is smaller than that of the outer sealing lip component, from the perspective of structural mechanics, this asymmetric support arm will cause the position of the support point of the force to move forward to the straight edge line segment on the outer sealing lip component when the force is not completely uniform. In this way, the support points of the forces on the inner sealing lip component and the outer sealing lip component of the metal sealing ring body are not on the same vertical plane. Under the same force, the rollover moment of the metal sealing ring body in the optimal working position is greatly reduced. The reason for the rollover moment is that the metal sealing ring body is subjected to a local high-pressure area on the surface of the elastic body when the high-temperature and high-pressure airflow passes through the sealing ring groove, thereby forming a rollover force. The anti-rollover moment is balanced with the rollover moment. Only when the anti-rollover moment is greater than the rollover moment will the structure not roll over and become unstable, thereby avoiding the metal sealing ring body from deviating from the optimal working position of the vertical axis due to the overturning force.

[0014] Secondly, in order to cope with different working environments, the metal sealing ring body is made of precipitation-strengthened nickel-based high-temperature alloy steel strip, and the metal sealing ring body is required to be used in a solid solution and aging state. This can eliminate the residual stress generated by the metal sealing ring body during the production process and stabilize the metallographic structure and design dimensions of the metal sealing ring body.

[0015] Then the surface of the metal sealing ring body is treated with chromium aluminum nitride coating (Al CrN), which can effectively reduce the wear and friction resistance of the sealing surface of the outer sealing lip component and the arc-shaped sealing surface of the inner sealing lip on the metal sealing ring body and the circular hole and cylindrical shaft surface to be sealed during interference fit assembly. At the same time, it also effectively reduces the wear of the sealing surface of the outer sealing lip component and the arc-shaped sealing surface of the inner sealing lip on the metal sealing ring body when the front exhaust manifold and the rear exhaust manifold move axially due to thermal expansion and contraction, thereby greatly improving the sealing performance and service life of the metal sealing ring body.

[0016] Finally, since the metal sealing ring body has a long service life and can be used repeatedly, the selection of different material thicknesses can make the sealing surface reach different elastic deformation pressures, thereby reducing the cost of use; therefore, the metal sealing ring body is particularly suitable for the sealing system of the segmented exhaust manifold of a diesel engine with a compact sealing structure, limited strength, and insufficient preload force. It can effectively solve the high temperature and high pressure sealing problems of the fluid sealing system. Overall, it has the characteristics of easy installation, long service life, and good sealing effect, and has extremely high practicality and promotion significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a cross-sectional structural diagram of the metal sealing ring body in the embodiment of the utility model;

[0018] Figure 2 yes Figure 1 An enlarged schematic diagram of a partial cross-sectional structure;

[0019] Figure 3 yes Figure 2 Schematic diagram of the partial cross-section structure dimensions;

[0020] Figure 4 It is a schematic diagram of the partial cross-sectional structure dimensions of an embodiment of the utility model;

[0021] Figure 5 yes Figure 2 The first step of the partial cross-section construction forms a process diagram;

[0022] Figure 6 yes Figure 2 The second step of the partial cross-section construction forms a process diagram;

[0023] Figure 7 yes Figure 2 The third step of the partial cross-section construction process diagram;

[0024] Figure 8 yes Figure 1 , Figure 2Schematic diagram of the principle structure of usage status.

[0025] Explanation of the reference numerals: 1. Metal sealing ring body; 2. Lip; 3. Inner sealing lip component; 4. Connecting component; 5. Outer sealing lip component; 6. Straight-edge line segment; 7. First opening lip; 8. Second opening lip; 9. Front exhaust manifold; 10. Rear exhaust manifold; 11. Front end inner hole guide slope; 12. Lifting cone slope; 13. Sealing ring groove; 14. First inner step portion of inner wall surface; 15. Second inner step portion of inner wall surface; 16. First outer step portion of outer wall surface; 17. Second outer step portion of outer wall surface; A. Inner end point of the semicircular arc of the connecting component; B. Outer end point of the semicircular arc of the connecting component; C. End point of the straight-edge line segment; D. Terminal end point of the first opening lip; E. Terminal end point of the second opening lip. DETAILED DESCRIPTION

[0026] The technical solution of this patent is further described in detail below in conjunction with specific implementation methods.

[0027] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0028] like Figure 1 , Figure 2 As shown, in the following embodiment, a self-tightening metal sealing ring is described, comprising a metal sealing ring body (1), wherein the metal sealing ring body (1) is a hollow metal circular ring, and an axially opened lip (2) is arranged on the circumferential direction of the end surface of the circular ring of the metal sealing ring body (1), so that the metal sealing ring body (1) constitutes a circular annular elastic body with an axially opened lip (2) on the circumferential direction of the end surface; the cross section of the metal sealing ring body (1) is an integrated structure formed by an inner sealing lip component (3), a connecting component (4), and an outer sealing lip component (5) connected in sequence through a smooth transition; the cross section of the connecting component (4) is a semicircular arc, the cross section of the inner sealing lip component (3) is an arc, and the cross section of the outer sealing lip component (5) includes a straight line segment (6) and an arc portion; the metal sealing ring body 1 can be made of a precipitation-strengthened nickel-based high-temperature alloy steel strip in a solid solution and aging state, and at the same time, the surface of the metal sealing ring body 1 is coated with a chromium aluminum nitride coating (Al CrN) treatment.

[0029] In order to clearly and completely explain the composition of the metal sealing ring body 1, the utility model selects an embodiment to describe the evolution process of the cross-sectional shape of the metal sealing ring body 1 by using the mutual transformation between points, lines, surfaces and arc surfaces in the xoy plane rectangular coordinate system, so that the metal sealing ring body 1 can be clearly seen from the initial original prototype conception to the final product model design, so as to understand the shape structure of the cross section of the metal sealing ring body 1 in a more comprehensive, systematic, simple and intuitive manner.

[0030] In the embodiment of the utility model, D` is the intersection point of the two rays of the opening angle and the outermost edge of the annular arc part; f is the length of the straight line segment; n is the inner diameter of the metal sealing ring body; m is the outer diameter of the metal sealing ring body; h is the axial height of the metal sealing ring body; s is the radial thickness of the metal sealing ring body; t is the ring wall thickness of the metal sealing ring body; r is the radius of the semicircular arc of the connecting part, the arc of the inner sealing lip part and the arc of the outer sealing lip part; α is the opening angle; β is the central angle of the arc of the inner sealing lip part and the arc of the outer sealing lip part; δ is the interference fit of the inner diameter of the second inner step portion of the inner wall of the front exhaust manifold joint end and the outer diameter of the first outer step portion of the outer wall of the rear exhaust manifold joint end with the radial thickness of the metal sealing ring body.

[0031] like Figure 5 As shown, the xoy plane rectangular coordinate system is established, with the origin O of the coordinate system as the center, a circle with a radius of r is drawn, and the intersection points of the circle with the x-axis are A(-r, 0) and B(r, 0), and then with the origin O of the coordinate system as the center, concentric circles with a radius of rt are drawn, where t is the ring wall thickness of the metal sealing ring body 1, and in the area Q of the two concentric circles = {(x, y)|x 2 +y2≤r2,x,y∈R,r>0} and the region W={(x,y)|x 2 +y2≥(rt)2,x, y∈R,r>t>0}, the annular arc portion G=Q∩W is the original prototype of the cross-sectional shape of the metal sealing ring body 1.

[0032] like Figure 6 As shown, in the plane region of the third and fourth quadrants of the xoy plane rectangular coordinate system, two concentric circular regions Q1 = {(x, y) | x 2 +y2≤r 2 ,x,y∈R and y≤0,r>0} and the region W1={(x,y)|x 2 The arc AB of the annular arc portion G1=Q1∩W1 between {x, y∈R and y≤0, r>t>0} is a semicircular arc on the cross section of the connecting member 4; the area Q2={(x, y)|x in the plane area of ​​the first quadrant and the second quadrant of the xoy plane rectangular coordinate system is in two concentric circular areas.2 +y2≤r 2 ,x,y∈R and y≥0,r>0} and the region W2={(x,y)|x 2 +y2≥(rt)2,x, y∈R and y≥0, r>t>0}, take points D`(rsin(α / 2), rcos(α / 2)) and E(-rsin(α / 2), rcos(α / 2)) with the coordinate axis y as the axis of symmetry on the outermost edge arc of the annular arc part G2=Q2∩W2, so that the central angle ∠D`OE=α formed by points D`, E and the center point O is not less than the opening angle α of 2π / 3 radians. Points D`(rsin(α / 2), rcos(α / 2)) and E(-rsin(α / 2), rcos(α / 2)) are the two intersection points of the two rays forming the opening angle α and the outermost edge of the annular arc part.

[0033] like Figure 7 As shown, the two concentric circular areas Q3 = {(x, y) | x 2 +y2≤r 2 ,x≥rsin(α / 2),0≤y≤rcos(α / 2),r>0} and the region W3={(x,y)|x 2 +y2≥(rt)2,x≥rsin(α / 2),0≤y≤rcos(α / 2),r>t>0}, on the circular arc part G3=Q3∩W3 with point B(r,0) and point D`(rsin(α / 2),rcos(α / 2)) as endpoints; then, taking the position of point B(r,0) as the starting point, the arc BD` with point B(r,0) and point D`(rsin(α / 2),rcos(α / 2)) as endpoints is moved as a whole along the y-axis direction and parallel to the y-axis by a length f not greater than 2πr / 3, so that after the overall longitudinal translation of the arc BD`, the original arc BD` forms two concentric circular areas Q4={(x,y)|x 2 +(y-2πr / 3)2≤r 2 ,x≥rs in(α / 2), 2πr / 3≤y≤rcos(α / 2)+2πr / 3, r>0} and area W={(x,y)|x 2+(y-2πr / 3)2≥(rt)2,x≥rsin(α / 2), 2πr / 3≤y≤rcos(α / 2)+2πr / 3, r>t>0}, the circular arc part G4=Q4∩W4 is the arc CD, arc CD is the arc with point C(r,2πr / 3) and point D(rsin(α / 2,2πr / 3+rcos(α / 2)) as endpoints, and the position of the endpoint B(r,0) of arc BD` is located at the position of point C(r,2πr / 3), the endpoint D` of arc BD`(rsin(α / 2,rcos(α / 2)) The position is located at the point D (rsin (α / 2), 2πr / 3 + rcos (α / 2)), the arc CD is the arc on the cross section of the outer sealing lip component 5, and the point D (rsin (α / 2), 2πr / 3 + rcos (α / 2)) is the end point of the second opening lip 8 on the outer sealing lip component 5; the moving trajectory of the arc BD' end point B (r, 0) is the BC segment whose length f is not greater than 2πr / 3, and the BC segment is the straight line segment 6 on the cross section of the outer sealing lip component 5. The area Q5 of the two concentric circles in the plane area located in the second quadrant of the xoy plane rectangular coordinate system = {(x, y) | x 2 +y2≤r 2 ,x≤-rsin(α / 2), 0≤y≤rcos(α / 2), r>0} and area W5={(x,y)|x 2 On the arc AE of the annular portion G5=Q5∩W5 between +y2≥(rt)2,x≤-rsin(α / 2), 0≤y≤rcos(α / 2), r>t>0}, the arc AE with point A(-r, 0) and point E(-rsin(α / 2), rcos(α / 2)) as endpoints is an arc on the cross section of the inner sealing lip component 3, and point E(-rsin(α / 2), rcos(α / 2)) is the tip end point of the first opening lip 7 on the inner sealing lip component 3.

[0034] The utility model selects specific embodiments, and systematically explains from the selection of metal alloy materials of the metal sealing ring body 1 to the structural stress analysis and the final product size design according to the working environment of the metal sealing ring body 1 and the sealing effect to be achieved.

[0035] like Figure 1-Figure 8As shown, in order to ensure the sealing effect of the metal sealing ring body 1 and the sealing performance of the sealing system, and to prevent the metal sealing ring body 1 from plastic deformation during operation, which may lead to sealing failure, its metal alloy material should have a higher yield limit; since the metal sealing ring body 1 mostly works in a high temperature and high pressure environment, its metal alloy material should have good high temperature resistance and corrosion resistance; furthermore, the metal sealing ring body 1 is usually formed by upper and lower die stamping and simple spinning of metal alloy strips, so the metal alloy material used to process the metal sealing ring body 1 should have good ductility and certain tensile strength; according to the Practical Metal Material Selection Manual and published by the Machinery Industry Press According to the National Standard of the People's Republic of China: Classification and Designation of High-Temperature Alloys and Intermetallic Compounds High-Temperature Materials (GB / T30566-2014), a metal alloy material that meets the requirements is selected to process the metal sealing ring body 1; the metal alloy material used for the metal sealing ring body 1 is made of GH4169 precipitation-strengthened nickel-based high-temperature alloy steel strip in a solid solution state, and the metal sealing ring body 1 formed by the metal alloy steel strip through upper and lower mold stamping and simple spinning is subjected to aging heat treatment, thereby eliminating the residual stress generated by the metal sealing ring body 1 during the production process and stabilizing the metallographic structure and design dimensions of the metal sealing ring body 1.

[0036] When the force analysis of the structure of the metal sealing ring body 1 is performed, it is found that the maximum stress position of the metal sealing ring body 1 in the compressed state is located on the top end surface of the semicircular arc with a radius of r of the connecting component 4, and the maximum radial elastic force position is located at the arc connection of the inner sealing lip component 3 and the outer sealing lip component 5 with the connecting component 4 in a smooth transition; since one end of the straight line segment 6 on the metal sealing ring body 1 is tangent to the semicircular arc with a radius of r on the connecting component 4, and the other end of the straight line segment 6 is tangent to the arc with a radius of r and a central angle β not greater than π / 6 radians, the two end points of the straight line segment 6 are respectively tangent to the connecting component The connection at the corner between the semicircular arc with a radius r on 4 and the arc with a radius r and a central angle β not greater than π / 6 radians on the outer sealing lip component 5 is a smooth connection through an arc transition, which can not only prevent the generation of a fragile surface at the corner, but also reduce the concentration of stress and avoid cracks caused by stamping or spinning. When the wall thickness of the stamped part or the spun part cannot be completely uniform, the connection between the thick wall and the thin wall adopts an arc transition connection form, which can avoid the concentration of stress caused by the sudden increase of local stress caused by the sudden change of wall thickness, thereby stabilizing the design size of the metal sealing ring body 1 and enhancing the sealing effect of the metal sealing ring body 1. At the same time, since the lip 2 arranged on the circumferential direction of the axial end face of the circular ring of the metal sealing ring body 1 faces the high-pressure area and is consistent with the exhaust gas flow direction, the first opening lip 7 of the inner sealing lip component 3 and the second opening lip 8 of the outer sealing lip component 5 tend to become larger under the action of the high-temperature and high-pressure fluid. Under the working state, the internal pressure causes the lip 2 on the circumferential direction of the axial end face of the circular ring of the metal sealing ring body 1 to radially open, thereby increasing the contact stress and contact width between the sealing surface of the second opening lip 8 of the outer sealing lip component 5 on the metal sealing ring body 1 and the sealing surface of the first opening lip 7 of the inner sealing lip component 3 and the inner wall sealing surface of the front exhaust manifold 9 and the outer side sealing surface of the rear exhaust manifold 10, thereby ensuring the sealing performance of the metal sealing ring body 1.Due to the improved sealing performance, while improving the stress condition of the metal sealing ring body 1, the contact area between the sealing surface of the outer sealing lip component 5 on the metal sealing ring body 1 and the arc-shaped sealing surface of the inner sealing lip component 3 is increased, and at the same time, the stress of the semicircular arc with a radius of r of the connecting component 4 is minimized. When analyzing the influence of various dimensions of the metal sealing ring body 1 on the structural strength and sealing performance of the metal sealing ring body 1, the internal and external pressures of the metal sealing ring body 1 can be ignored, and the difference in elastic modulus and yield strength of the metal alloy material at working temperature and room temperature is analyzed. It is not difficult to find that the relative reduction in yield strength of the metal alloy material at high temperature is greater than the relative reduction in elastic modulus; in order to ensure that the metal sealing ring body 1 can maintain structural stability at both room temperature and working temperature, it should be considered to select the mechanical analysis of the metal sealing ring body 1 under the working state when designing the size, and the influence between the size of each component on the metal sealing ring body 1 and the strength of the metal sealing ring body 1 is analyzed by finite element simulation software to determine the maximum radial elastic force reached by the metal sealing ring body 1 at the minimum deformation.

[0037] When designing the dimensions of each part of the metal sealing ring body 1, all dimensional data are retained to two decimal places and the value of π is 3.14. The minimum value of the opening angle α is 2π / 3 radians. Since the two end points D' and point E that constitute the arc of the opening angle α are points with the coordinate axis y as the axis of symmetry, when the minimum value of the opening angle α is selected as 2π / 3 radians, it is deduced that the central angle β corresponding to the arc on the inner sealing lip component 3 and the arc on the outer sealing lip component 5 is π / 6 radians, but these do not represent the final design dimensions of the product. The inner wall surface of the joint end of the front exhaust manifold 9 is provided with a second inner step portion 15 of the inner wall surface, and the outer wall surface of the joint end of the rear exhaust manifold 10 is provided with a first outer step portion 16 of the outer wall surface. Since the second inner step portion 15 of the inner wall surface of the joint end of the front exhaust manifold 9 and the first outer step portion 16 of the outer wall surface of the joint end of the rear exhaust manifold 10 form a sealing ring groove 13, the second inner step portion 15 of the inner wall surface The inner diameter size and the outer diameter size of the first outer step portion 16 on the outer wall surface determine the size of the three-dimensional space of the formed sealing ring groove 13, thereby determining the inner diameter Φn, outer diameter Φm, axial height h, and radial thickness s of the metal sealing ring body 1; if the inner diameter size of the second inner step portion 15 on the inner wall surface of the front exhaust manifold 9 joint end is 67.80 mm and the outer diameter size of the first outer step portion 16 on the outer wall surface of the rear exhaust manifold 10 joint end is 59.20 mm, and at the same time, when designing the size of the metal sealing ring body 1, it is necessary to consider that the inner diameter size of the second inner step portion 15 on the inner wall surface of the front exhaust manifold 9 joint end and the outer diameter size of the first outer step portion 16 on the outer wall surface of the rear exhaust manifold 10 joint end are both interference fits with the radial thickness s of the metal sealing ring body 1 and the interference amount δ is about 0.20 mm, then the inner diameter Φn of the metal sealing ring body 1 is 59.00 mm and the outer diameter Φm is 68.00 mm.

[0038] Since the ring wall thickness t of the metal sealing ring body 1 greatly affects the elastic deformation of the sealing ring, it also has a relatively large impact on the strength of the metal sealing ring body 1. When t increases, the radial stiffness of the metal sealing ring body 1 increases, the elastic stress of the sealing surface increases, and the sealing effect is enhanced. However, as the maximum stress of the metal sealing ring body 1 increases, it is easy to cause the metal sealing ring body 1 to deform and fail due to excessive radial pressure. According to the requirements of the outer dimensions of the metal sealing ring body 1 and the requirements of the elastic deformation of the metal sealing ring body 1, a suitable ring wall thickness t of the metal sealing ring body 1 should be selected, and the ring wall thickness t of the metal sealing ring body 1 is 0.30mm.

[0039] Since the semicircular area of ​​the connecting component 4 of the metal sealing ring body 1 is the location where the stress of the entire metal sealing ring body 1 is concentrated, the radius r of the semicircular shape of the connecting component 4 has a direct impact on the maximum stress of the metal sealing ring body 1. When the radius r of the semicircular shape of the connecting component 4 increases, the elastic deformation of the metal sealing ring body 1 increases, resulting in a sharp increase in the stress of the semicircular area of ​​the connecting component 4, and a significant increase in the risk of fracture of the metal sealing ring body 1. The size of the radius r of the semicircular shape of the connecting component 4 should be reasonably designed. The inner diameter size of the second inner step portion 15 of the inner wall surface and the first outer step portion 16 of the outer wall surface should be set according to the inner wall surface of the joint end of the front exhaust manifold 9. The outer diameter of 16 and the maximum tensile strength, body hardness, elasticity and ductility of the GH4169 precipitation-strengthened nickel-based high-temperature alloy steel strip selected in the solid solution state of the metal sealing ring body 1, and the minimum interference amount δ value of the metal sealing ring body 1 assembly is reasonably selected, so the radial thickness s of the metal sealing ring body 1 and the inner diameter of the second inner step portion 15 of the inner wall surface and the outer diameter of the first outer step portion 16 of the outer wall surface The interference amount δ is about 0.20mm; and then according to the inner diameter size of the second inner step portion 15 of the inner wall surface of the front exhaust manifold 9 The outer diameter size of the first outer step portion 16 of the outer wall surface is set to form The three-dimensional space size of the sealing ring groove 13 determines the radius r of the semicircular arc of the connecting component 4 of the metal sealing ring body 1; in a low-temperature environment, the metal sealing ring body 1 can fully utilize the radial elastic force generated by its own interference to elastically deform the sealing surface of the metal sealing ring body 1 to block the gas leakage channel, and at the same time, in order to avoid the metal sealing ring body 1 after compression, the distance between the inner sealing lip component 3 and the first opening lip 7 and the second opening lip 8 on the outer sealing lip component 5 of the metal sealing ring body 1 becomes narrow, thereby affecting the lip 2 arranged on the axial end surface of the circular ring of the metal sealing ring body 1 under high-temperature and high-pressure working conditions. The metal sealing ring body 1 is provided with a radially open opening under the action of the force, thereby causing the deformation of the inner diameter of the second inner step portion 15 of the inner wall surface of the joint end of the front exhaust manifold 9 and the outer diameter of the first outer step portion 16 of the outer wall surface of the joint end of the rear exhaust manifold 10 due to temperature and pressure fluctuations, and the separation of the inner sealing lip component 3 and the outer sealing lip component 5 of the metal sealing ring body 1, resulting in a reduction in the sealing specific pressure. Therefore, the opening angle α of the axial end face of the circular ring of the metal sealing ring body 1 is not less than 2π / 3 radians, the radius r of the semicircular arc of the connecting component 4 of the metal sealing ring body 1 is 2.25 mm, and the radial thickness s of the metal sealing ring body 1 is 4.50 mm.

[0040] The length of the inner sealing lip component 3 of the metal sealing ring body 1 is smaller than that of the outer sealing lip component 5, and the cross-sectional shape of the outer sealing lip component 5 includes a straight line segment 6 and an arc-shaped portion. From the perspective of structural mechanics, this asymmetric support arm can make the position of the support point of the force move forward to the straight line segment 6 on the outer sealing lip component 5 when the force is not completely uniform, so that the support points of the force on the inner sealing lip component 3 and the outer sealing lip component 5 of the metal sealing ring body 1 are not on the same vertical plane, and under the same force, the rollover moment of the metal sealing ring body 1 at the optimal working position is greatly reduced; the reason for the rollover moment is that the metal sealing ring body 1 is subjected to a local high-pressure area on the elastic body surface of the metal sealing ring body 1 in the sealing ring groove 13, thereby forming a rollover force, and the anti-rollover moment is balanced with the rollover moment. Only when the anti-rollover moment is greater than the rollover moment will the support structure not produce rollover instability, thereby avoiding the metal sealing ring body 1 from deviating from the vertical axial optimal working position due to the overturning force. When the radial thickness s of the metal sealing ring body 1 is constant, if the total axial height h of the elastic sealing section of the outer sealing lip component 5 is constant, the length f of the straight edge segment 6 on the outer sealing lip component 5 can only be increased by reducing the length of the arc with a radius r and a central angle β not greater than π / 6 radians on the outer sealing lip component 5, thereby increasing the maximum anti-rollover moment of the metal sealing ring body 1. When adjusting the length of the arc with a radius r and a central angle β not greater than π / 6 radians on the outer sealing lip component 5, the axial rigidity of the metal sealing ring body 1 is also affected. Therefore, while increasing the maximum anti-rollover moment of the metal sealing ring body 1, the influence of the axial rigidity of the metal sealing ring body 1 on the structural strength should be comprehensively considered, and the f value of the straight edge segment 6 should be reasonably selected. Therefore, the length f value of the straight edge segment 6 on the outer sealing lip component 5 of the metal sealing ring body 1 is selected to be equal to 2πr / 3=4.71mm, and the total axial height h of the metal sealing ring body 1 is equal to r+f+rcos(α / 2)=8.09mm.

[0041] Since the sum of the length of the cross section of the inner sealing lip component 3 and the length of the cross section of the outer sealing lip component 5 of the metal sealing ring body 1 is equal to the length of the cross section of the connecting component 4, when the length f of the straight edge segment 6 on the outer sealing lip component 5 of the metal sealing ring body 1 is selected to be no greater than 2πr / 3, the length of the arc with a radius r and a central angle β no greater than π / 6 radians on the inner sealing lip component 3 and the outer sealing lip component 5 of the metal sealing ring body 1 changes with the change of the length f of the straight edge segment 6 on the outer sealing lip component 5 of the metal sealing ring body 1, and the inner sealing lip component 3 of the metal sealing ring body 1 is The change in the length of the arc with a radius r and a central angle β not greater than π / 6 radians on the inner sealing lip component 3 and the outer sealing lip component 5 has an influence on the structure of the metal sealing ring body 1 mainly on the distance that the sealing contact surface position can move after the metal sealing ring body 1 is compressed. When the length of the arc with a radius r and a central angle β not greater than π / 6 radians on the inner sealing lip component 3 and the outer sealing lip component 5 of the metal sealing ring body 1 is larger, the distance that the sealing contact surface position can move after the metal sealing ring body 1 is compressed is larger, which is equivalent to the length f value of the straight edge line segment 6 on the outer sealing lip component 5 of the metal sealing ring body 1 becoming smaller, thereby causing the metal sealing ring body 1 to be compressed. The first opening lip 7 of the inner sealing lip component 3 of the body 1 and the second opening lip 8 of the outer sealing lip component 5 become larger, which eventually leads to a decrease in the anti-rollover moment of the metal sealing ring body 1 and an increase in the maximum stress of the semicircular arc of the connecting component 4 of the metal sealing ring body 1. Considering that the arc length value of the radius r and the central angle β of the inner sealing lip component 3 and the outer sealing lip component 5 of the metal sealing ring body 1 is not greater than π / 6 radians directly affects the maximum stress borne by the metal sealing ring body 1 and the contact area of ​​the sealing surface of the metal sealing ring body 1 and the anti-rollover moment of the metal sealing ring body 1, the outer side of the metal sealing ring body 1 should be adjusted within a reasonable range. The length of the straight edge segment 6 on the sealing lip component 5 and the length of the arc with a radius r and a central angle β not greater than π / 6 radians on the inner sealing lip component 3 and the outer sealing lip component 5 of the metal sealing ring body 1 are selected to be of moderate size, and a smaller value is selected as appropriate. Therefore, the arc with a radius r and a central angle β not greater than π / 6 radians on the inner sealing lip component 3 and the outer sealing lip component 5 of the metal sealing ring body 1 should be selected with a central angle β equal to π / 6 radians, then the length of the arc with a radius r and a central angle β not greater than π / 6 radians on the inner sealing lip component 3 and the outer sealing lip component 5 of the metal sealing ring body 1 is 1.18 mm.

[0042] Embodiments of the utility model:

[0043] exist Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 8In the illustrated embodiment, when the pressure borne by the sealing system is axial pressure, the metal sealing ring body 1 is used. The sealing system is composed of a front exhaust manifold 9, a rear exhaust manifold 10 and a metal sealing ring body 1. The inner wall surface of the joint end of the front exhaust manifold 9 is provided with a first inner step portion 14 and a second inner step portion 15 on the inner wall surface. The front end inner hole of the pipe opening at the joint end of the front exhaust manifold 9 is provided with a front end inner hole guide inclined surface 11. The outer wall surface of the joint end of the rear exhaust manifold 10 is provided with a first outer step portion 16 and a second outer step portion 17 on the outer wall surface. A lifting frustum inclined surface 12 is provided on the first outer step portion 16 on the outer wall surface near the second outer step portion 17 on the outer wall surface. The first inner step portion 14 on the inner wall surface and the first outer step portion 16 on the outer wall surface are positioned and connected by a small radial clearance fit stop. Since the first inner step portion 14 on the inner wall surface and the first outer step portion 16 on the outer wall surface are fitted with a small radial clearance of about 0.1 mm, a first sealing structure is formed at the radial clearance fit stop positioning connection position, which can significantly reduce the pressure of the leaked gas and reduce the impact of the high-temperature gas on the rear structure. The second inner step portion 15 of the inner wall surface and the first outer step portion 16 of the outer wall surface form a sealing ring groove 13. Now the metal sealing ring body 1 is installed in the sealing ring groove 13, and the lip 2 axially opened in the circumferential direction of the end face of the metal sealing ring body 1 faces the inside of the sealing system in the same direction as the airflow. Since the sealing surface of the outer sealing lip component 5 on the metal sealing ring body 1 and the arcuate sealing surface of the inner sealing lip component 3 are interference fit with the sealing surface of the second inner step portion 15 of the inner wall surface and the sealing surface of the first outer step portion 16 of the outer wall surface, the sealing surface of the outer sealing lip component 5 on the metal sealing ring body 1 and the arcuate sealing surface of the inner sealing lip component 3 are interference fit with the sealing surface of the second inner step portion 15 of the inner wall surface and the sealing surface of the first outer step portion 16 of the outer wall surface. The sealing surfaces of the first outer step portion 16 on the outer wall surface of the rear exhaust manifold 10 are tightly attached to each other. Since the metal sealing ring body 1 is elastically deformed by elastic radial compression during interference assembly, elastic potential energy is stored. When the pressure is removed or reduced, the stored elastic potential energy is released, a certain degree of rebound occurs, the deformation amount is reduced, and the normal sealing working state is entered. At the initial stage of deformation, the sealing surface of the outer sealing lip component 5 on the metal sealing ring body 1 and the sealing surface of the second inner step portion 15 on the inner wall surface of the front exhaust manifold 9 are in narrow band contact, and the arc-shaped sealing surface of the inner sealing lip component 3 on the metal sealing ring body 1 and the sealing surface of the first outer step portion 16 on the outer surface of the rear exhaust manifold 10 are in line contact, thereby establishing an initial seal.At the same time, since the inner step portion of the inner wall surface of the joint end of the front exhaust manifold 9 and the outer step portion of the outer wall surface of the joint end of the rear exhaust manifold 10 are positioned and connected through the gap fitting stop, a comb tooth sealing structure, also called a labyrinth sealing structure, is formed. The labyrinth sealing structure reduces the leakage loss of the fluid medium by reducing the pressure difference, thereby gradually reducing the fluid medium pressure, and ultimately can also achieve the effects of labyrinth sealing and shock absorption and energy dissipation for the sealing system. Under actual working conditions, the sealing surface of the outer sealing lip component 5 and the arcuate sealing surface of the inner sealing lip component 3 on the metal sealing ring body 1 may be separated from the sealing surface of the second inner step portion 15 of the inner wall surface of the front exhaust manifold 9 and the sealing surface of the first outer step portion 16 of the outer wall surface of the rear exhaust manifold 10 due to exhaust temperature and pressure fluctuations or deformation of the exhaust pipe under the action of cold and hot stresses. At this time, since the metal sealing ring body 1 has good resilience and has previously generated large contact stress and elastic deformation when subjected to radial compression, the sealing surface of the outer sealing lip component 5 and the arcuate sealing surface of the inner sealing lip component 3 on the metal sealing ring body 1 can still contact and fit with the microscopically uneven parts on the sealing surface of the second inner step portion 15 of the inner wall surface of the front exhaust manifold 9 and the sealing surface of the first outer step portion 16 of the outer wall surface of the rear exhaust manifold 10, thereby enabling the metal sealing ring body 1 to achieve a sealing effect. In addition, the metal sealing ring body 1 is a self-tightening sealing ring. Since the lip 2 axially opened in the circumferential direction of the end face of the metal sealing ring body 1 faces the inside of the sealing system and is in the same direction as the airflow, under the working state, the internal pressure causes the lip 2 on the circumferential direction of the axial end face of the metal sealing ring body 1 to radially open, thereby increasing the contact stress and contact width between the sealing surface of the outer sealing lip component 5 and the arc-shaped sealing surface of the inner sealing lip component 3 on the metal sealing ring body 1 and the sealing surface of the second inner step portion 15 of the inner wall surface of the front exhaust manifold 9 and the sealing surface of the first outer step portion 16 of the outer wall surface of the rear exhaust manifold 10, thereby ensuring the sealing performance of the metal sealing ring body 1.In addition, since the length of the inner sealing lip component 3 on the metal sealing ring body 1 is smaller than that of the outer sealing lip component 5, from the perspective of structural mechanics, this asymmetric support arm causes the position of the support point of the force to move forward to the straight line segment on the outer sealing lip component when the force is not completely uniform. In this way, the support points of the force on the inner sealing lip component 3 and the outer sealing lip component 5 of the metal sealing ring body 1 are not on the same vertical plane. Under the same force, the rollover moment of the metal sealing ring body 1 at the optimal vertical axial working position is greatly reduced. The reason for the rollover moment is that the metal sealing The ring body 1 is subjected to high-temperature and high-pressure airflow passing through the elastic body in the sealing ring groove 13, and a local high-pressure area is generated on the surface of the elastic body, thereby forming a rollover force. The anti-rollover moment is balanced with the rollover moment. Only when the anti-rollover moment is greater than the rollover moment will the structure not produce rollover instability, thereby avoiding the metal sealing ring body 1 from deviating from the vertical axial working position due to the overturning force, and effectively fixing the metal sealing ring body 1 at the best vertical axial working position in the sealing ring groove 13 formed by the second inner step portion 15 on the inner wall surface of the joint end of the front exhaust manifold 9 and the first outer step portion 16 on the outer wall surface of the joint end of the rear exhaust manifold 10. At the same time, a lifting truncated cone inclined surface 12 is provided on the first step portion 16 of the outer wall surface of the joint end of the rear exhaust manifold 10, close to the second outer step portion 17 of the outer wall surface. The lifting truncated cone inclined surface 12 can further compress the radial size of the annular member of the metal sealing ring body 1 under the push of the exhaust gas, thereby increasing the sealing surface of the outer sealing lip component 5 on the metal sealing ring body 1, the arcuate sealing surface of the inner sealing lip component 3, and the arcuate sealing surface of the connecting component 4 and the sealing surface of the second inner step portion 15 of the inner wall surface of the joint end of the front exhaust manifold 9, the sealing surface of the first outer step portion 16 of the outer wall surface of the joint end of the rear exhaust manifold 10, and the outer wall surface of the first outer step portion 16 of the outer wall surface of the rear exhaust manifold 10. The contact stress and contact width on the end face of the second outer step portion 17 ensure the sealing performance of the metal sealing ring body 1, so that the sealing surface of the outer sealing lip component 5 of the metal sealing ring body 1 and the sealing surface of the second inner step portion 15 of the inner wall surface of the front exhaust manifold 9 are elastically deformed, and the narrow band contact at the initial stage of deformation is transformed into a wide band contact, and the arcuate sealing surface of the inner sealing lip component 3 on the metal sealing ring body 1 and the arcuate sealing surface of the connecting component 4 are elastically deformed with the sealing surface of the first outer step portion 16 of the outer wall surface of the rear exhaust manifold 10 and the end face of the second outer step portion 17 of the outer wall surface, and the line contact at the initial stage of deformation is transformed into a narrow band contact, thereby achieving sealing of the system fluid medium.

[0044] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes within the technical scope disclosed by the present invention according to the technical scheme and the utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A self-tightening metal sealing ring, comprising a metal sealing ring body (1), characterized in that: The metal sealing ring body (1) is a hollow metal circular ring, and an axially opened lip (2) is arranged on the circumference of the end surface of the circular ring of the metal sealing ring body (1), so that the metal sealing ring body (1) constitutes a circular annular elastic body with an axially opened lip (2) on the circumference of the end surface; the cross section of the metal sealing ring body (1) is an integrated structure formed by connecting the inner sealing lip component (3), the connecting component (4), and the outer sealing lip component (5) in sequence through smooth transition; the cross section of the connecting component (4) is a semicircular arc; the metal sealing ring body (1) is an interference fit with the shaft and hole to be sealed.

2. A self-tightening metal sealing ring according to claim 1, characterized in that: The cross-sectional shape of the inner sealing lip component (3) is an arc shape, and the cross-sectional shape of the outer sealing lip component (5) includes a straight line segment (6) and an arc-shaped portion.

3. A self-tightening metal sealing ring according to claim 2, characterized in that: The circular arc on the cross section of the inner sealing lip component (3) and the circular arc on the cross section of the outer sealing lip component (5) are both circular arcs with a central angle of no more than π / 6 radians; The circular arc on the cross section of the inner sealing lip component (3) and the upper semicircular arc on the cross section of the connecting component (4) are concentric circular arcs with equal radius; One end point of the arc-shaped cross section of the inner sealing lip component (3) is the inner end point (A) of the semicircular arc of the connecting component, and the other end point of the arc-shaped cross section of the inner sealing lip component (3) is the distal end point (E) of the second opening lip; One end of the straight line segment (6) is tangent to the semicircular arc on the cross section of the connecting component (4), and the tangent point is the outer end point (B) of the semicircular arc of the connecting component; The end of the straight line segment (6) away from the connecting component (4) is tangent to the arc on the cross section of the outer sealing lip component (5), and the tangent point is the end point (C) of the straight line segment; An end of the outer sealing lip component (5) away from the connecting component (4) is a distal end point (D) of the first opening lip.

4. A self-tightening metal sealing ring according to claim 3, characterized in that: The length of the straight line segment (6) is not greater than 2π / 3 times the radius of the semicircular arc on the cross section of the connecting component (4); The sum of the length of the cross section of the inner sealing lip component (3) and the length of the cross section of the outer sealing lip component (5) is equal to the length of the cross section of the connecting component (4); The inwardly turned parts of the lip opening (2) which is axially opened in the circumferential direction of the end surface of the circular ring of the metal sealing ring body (1) and the circular arc on the cross section of the inner sealing lip component (3) and the circular arc on the cross section of the outer sealing lip component (5) are respectively the first opening lip (7) and the second opening lip (8).

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