Stainless steel graphite ring high-temperature sealing structure of locomotive engine exhaust system

Abstract

The invention discloses a locomotive engine exhaust system stainless steel graphite ring high-temperature sealing structure which comprises a first exhaust pipe and a second exhaust pipe, the outer portions of the first exhaust pipe and the second exhaust pipe are locked through a locking piece, and a sealing ring groove is formed in the contact face of the first exhaust pipe or the second exhaust pipe. A sealing piece capable of deforming under stress is arranged in the sealing ring groove, and the sealing piece can deform in the axis direction of the first exhaust pipe or the second exhaust pipe under the action of leaked waste gas. According to the stainless steel graphite ring high-temperature sealing structure of the locomotive engine exhaust system, the V-shaped stainless steel graphite sealing ring is adopted, the graphite ring is attached to the exhaust pipe more tightly along with increase of waste gas force, the sealing effect is good, and meanwhile the problem that a graphite gasket is prone to damage when a pipeline is disassembled and assembled repeatedly is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of engine exhaust, and particularly to a high-temperature sealing structure of a stainless steel graphite ring for a locomotive engine exhaust system. Background Art

[0002] Previously, asbestos gaskets with high temperature resistance were generally used for sealing the exhaust pipe of the exhaust system of domestic locomotive engines. With the environmental protection requirements, the high-temperature asbestos gaskets have been replaced with, for example, Figure 1 the flexible graphite composite reinforced plate gasket, graphite metal wound gasket, steel-clad graphite gasket, etc. shown in the figure. Due to the elasticity of the graphite gasket, and the influence of high temperature and vibration, the pre-tightening force of the flange connection bolts between the two exhaust pipes is likely to fail and become loose. After the bolts become loose, the graphite gasket is damaged by the impact of high-temperature and high-pressure gas. After the gasket is damaged, a large amount of high-temperature gas leaks, affecting the normal operation of the engine. In severe cases, it may cause a fire accident. Therefore, it is necessary to regularly check the looseness of the connection bolts between the exhaust system pipelines. Summary of the Invention

[0003] The purpose of the present invention is to provide a high-temperature sealing structure of a stainless steel graphite ring for a locomotive engine exhaust system to solve the problems in the prior art that high temperature and vibration are likely to cause the pre-tightening force of the flange connection bolts between the two exhaust pipes to fail and become loose, and after the bolts become loose, the graphite gasket is damaged by the impact of high-temperature and high-pressure gas, and after the gasket is damaged, a large amount of high-temperature gas leaks, affecting the normal operation of the engine, and in severe cases, it may cause a fire accident.

[0004] The present invention is achieved by the following solution:

[0005] A high-temperature sealing structure of a stainless steel graphite ring for a locomotive engine exhaust system includes a first exhaust pipe and a second exhaust pipe. The first exhaust pipe and the second exhaust pipe are locked externally by a locking member. A sealing ring groove is provided in the contact surface of the first exhaust pipe or the second exhaust pipe. A seal that can be deformed under force is provided in the sealing ring groove. When the seal is affected by the leaked exhaust gas, it can deform along the axial direction of the first exhaust pipe or the second exhaust pipe.

[0006] Based on the above high-temperature sealing structure of a stainless steel graphite ring for a locomotive engine exhaust system, the sealing ring groove is a ring groove with a rectangular cross-section, and the position of the sealing ring groove is set away from the central gas path of the first exhaust pipe and / or the second exhaust pipe.

[0007] Based on the above high-temperature sealing structure of a stainless steel graphite ring for a locomotive engine exhaust system, the seal includes a stainless steel inner ring, a stainless steel outer ring, and a graphite ring; the graphite ring is arranged between the stainless steel inner ring and the stainless steel outer ring; the overall thickness of the stainless steel inner ring, the stainless steel outer ring, and the graphite ring is adapted to the size of the sealing ring groove.

[0008] Based on the above-mentioned high-temperature sealing structure of the stainless steel graphite ring for the exhaust system of a locomotive engine, the stainless steel inner ring and the stainless steel outer ring are the same. The stainless steel inner ring includes a first connecting ring plate and a second connecting ring plate. The first connecting ring plate and the second connecting ring plate are connected into one body through a V-shaped ring groove. The connection between the V-shaped ring groove and the first connecting ring plate and the second connecting ring plate is arc-shaped. The protruding direction of the V-shaped ring groove is from the stainless steel inner ring to the stainless steel outer ring.

[0009] Based on the above-mentioned high-temperature sealing structure of the stainless steel graphite ring for the exhaust system of a locomotive engine, when the seal is assembled in the seal ring groove, the V-shaped ring groove on the stainless steel outer ring contacts the side wall of the seal ring groove. The stainless steel inner ring is arranged close to the central air passage, and the stainless steel outer ring is arranged far from the central air passage.

[0010] Based on the above-mentioned high-temperature sealing structure of the stainless steel graphite ring for the exhaust system of a locomotive engine, the graphite layer in the graphite ring is evenly arranged between the cavities of the stainless steel inner ring and the stainless steel outer ring, and fits with the protruding part of the V-shaped ring groove in the stainless steel inner ring and the concave part of the V-shaped ring groove in the stainless steel outer ring.

[0011] Based on the above-mentioned high-temperature sealing structure of the stainless steel graphite ring for the exhaust system of a locomotive engine, the locking member includes a high-temperature bolt, a high-temperature locknut, a high-temperature double-stack self-locking lock washer, and a length-diameter ratio adjusting sleeve. The high-temperature bolt passes through the flange at the connection of the first exhaust pipe and the second exhaust pipe. The high-temperature locknut is arranged at the end of the high-temperature bolt. The length-diameter ratio adjusting sleeve is sleeved between the high-temperature locknut and the flange. The high-temperature double-stack self-locking lock washer is arranged at the contact part between the high-temperature locknut and the length-diameter ratio adjusting sleeve.

[0012] Based on the above-mentioned high-temperature sealing structure of the stainless steel graphite ring for the exhaust system of a locomotive engine, the depth of the seal ring groove is 3.0 - 3.5 mm, the width is 5.0 - 7.5 mm, and the gap between the seal and the seal ring groove is 0.5 - 1.0 mm. The thickness of the graphite ring is 3.2 - 4.0 mm. After the seal is installed in the seal ring groove, there is a compression amount of 0.2 - 0.5 mm.

[0013] Based on the above-mentioned high-temperature sealing structure of the stainless steel graphite ring for the exhaust system of a locomotive engine, both the stainless steel inner ring and the stainless steel outer ring are made of 06Cr19Ni10 stainless steel sheets with a thickness of 0.3 mm.

[0014] Based on the above-mentioned high-temperature sealing structure of the stainless steel graphite ring for the exhaust system of a locomotive engine, the high-temperature bolt is made of high-temperature resistant stainless steel 40Cr10Si2Mo - GB / T20878 - 2007 and is quenched and tempered. The double-stack self-locking lock washer is made of GH2132 high-temperature alloy material.

[0015] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are as follows:

[0016] 1. For the high-temperature sealing structure of the stainless steel graphite ring in the exhaust system pipeline of the locomotive engine in this solution, the rigid contact of the flange surface of the engine exhaust pipe is sealed by a V-shaped stainless steel graphite ring, which solves the problem of the failure and loosening of the bolt pre-tightening force caused by the elasticity of the graphite gasket.

[0017] 2. For the high-temperature sealing structure of the stainless steel graphite ring in the exhaust system of the locomotive engine in this solution, with the increase of the exhaust gas force received by the V-shaped stainless steel graphite sealing ring, the graphite ring fits more closely with the exhaust pipe, resulting in good sealing effect. At the same time, it solves the problem that the graphite gasket is easily damaged during repeated disassembly and assembly of the pipeline.

[0018] 3. For the high-temperature sealing structure of the stainless steel graphite ring in the exhaust system of the locomotive engine in this solution, the high-temperature bolts and nuts are made of heat-resistant stainless steel 40Cr10Si2Mo - GB / T20878 - 2007 and are quenched and tempered. They have a small expansion coefficient, high heat resistance, and will not loosen due to the high-temperature creep of the bolts after connection and tightening. In addition, a long diameter ratio adjustment sleeve is added to ensure that the long diameter ratio of the bolts is ≥5 when connecting the two exhaust pipes, preventing the sealing failure caused by the loosening of the bolts and nuts and achieving good sealing effect.

[0019] 4. For the high-temperature sealing structure of the stainless steel graphite ring in the exhaust system of the locomotive engine in this solution, double-stack self-locking lock washers made of GH2132 superalloy material are adopted, preventing the sealing failure caused by the loosening of the bolts and nuts and achieving good sealing effect.

[0020] 5. In this solution, the V-shaped graphite ring is easier to compress, ensuring the rigid contact and tight fit of the flange surfaces of the two exhaust pipes during installation. The high-pressure exhaust gas force acts on the V-shaped surface of the inner ring of the stainless steel graphite ring, enabling the upper part of the graphite ring to fit better with the flange surface of the first exhaust pipe and the lower part of the graphite ring to fit better with the bottom surface of the ring groove of the second exhaust pipe, using the pressure of the exhaust gas itself for sealing. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic structural diagram of the prior art;

[0022] Figure 2 is a schematic structural diagram of the whole of the present invention;

[0023] Figure 3 is an enlarged schematic structural diagram of the seal in the present invention;

[0024] Figure 4 is a top view schematic structural diagram of the high-temperature double-stack self-locking lock washer in the present invention;

[0025] Figure 5This is a schematic side view structure diagram of the high-temperature double-stack self-locking anti-loosening washer in the present invention;

[0026] In the figure: 1. First exhaust pipe; 2. Second exhaust pipe; 3. Locking member; 4. Sealing ring groove; 5. Sealing member; 6. Central gas path; 7. Flange; 31. High-temperature bolt; 32. High-temperature anti-loosening nut; 33. High-temperature double-stack self-locking anti-loosening washer; 34. Long diameter ratio adjustment sleeve; 51. Stainless steel inner ring; 52. Stainless steel outer ring; 53. Graphite ring; 511. First connecting ring plate; 512. Second connecting ring plate; 513. V-shaped ring groove. Detailed implementation manners

[0027] All the features disclosed in this specification, or all the steps in the disclosed methods or processes, except for mutually exclusive features and / or steps, can be combined in any manner.

[0028] Any feature disclosed in this specification (including any additional claims, abstract) can be replaced by other equivalent or similar-purpose alternative features unless specifically stated. That is, unless specifically stated, each feature is only an example of a series of equivalent or similar features.

[0029] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a predetermined orientation, be constructed and operated in a predetermined orientation, and therefore should not be construed as a limitation to the present invention.

[0030] In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features.

[0031] Embodiment 1

[0032] As Figures 2 to 5 shown, the present invention provides a technical solution:

[0033] A stainless steel graphite ring 53 high-temperature sealing structure for a locomotive engine exhaust system, which at least includes but is not limited to a first exhaust pipe 1 and a second exhaust pipe 2. The first exhaust pipe 1 and the second exhaust pipe 2 are locked externally by a locking member 3. A sealing ring groove 4 is provided in the contact surface of the first exhaust pipe 1 or the second exhaust pipe 2, and a sealable member 5 that can be deformed under force is provided in the sealing ring groove 4. When the sealing member 5 is affected by the leaked exhaust gas, it can deform along the axial direction of the first exhaust pipe 1 or the second exhaust pipe 2.

[0034] Based on the above structure, in this solution, the first exhaust pipe 1 and the end of the second exhaust pipe are butted as a whole, and the first exhaust pipe 1 and the second exhaust pipe 2 are locked by the locking member 3. Since the first exhaust pipe 1 and the second exhaust pipe 2 are in end contact, after the bolts are tightened to the specified torque, there is no pre-tightening force failure caused by the elasticity of the gasket, and the bolts are not likely to loosen. At the same time, a deformable seal 5 is arranged in the sealing ring groove 4 for sealing. The exhaust gas pressure that may leak can strengthen the sealing effect and make the sealing more tight.

[0035] As an example, the sealing ring groove 4 can be a ring groove with a rectangular cross-section, and the position of the sealing ring groove 4 is set away from the central gas path 6 of the first exhaust pipe 1 and / or the second exhaust pipe 2.

[0036] Based on the above structure, setting the sealing ring groove 4 away from the central gas path 6 of the first exhaust pipe 1 and / or the second exhaust pipe 2 can enable more butting contact surfaces at the ends of the first exhaust pipe 1 and the second exhaust pipe 2 to achieve relative sealing, and minimize exhaust gas leakage as much as possible. By setting the sealing ring groove 4 as a rectangular structure, it is convenient for later processing and also convenient for the assembly of the seal 5.

[0037] As an example, the seal 5 can include a stainless steel inner ring 51, a stainless steel outer ring 52, and a graphite ring 53; the graphite ring 53 is arranged between the stainless steel inner ring 51 and the stainless steel outer ring 52; the overall thickness of the stainless steel inner ring 51, the stainless steel outer ring 52, and the graphite ring 53 is adapted to the size of the sealing ring groove 4.

[0038] Based on the above structure, using stainless steel rings on both sides of the graphite layer can ensure that the graphite ring 53 has sufficient strength, and at the same time, setting the overall thickness of the stainless steel inner ring 51, the stainless steel outer ring 52, and the graphite ring 53 to be adapted to the size of the sealing ring groove 4 can enable the seal 5 to be assembled quickly and accurately.

[0039] As an example, the stainless steel inner ring 51 and the stainless steel outer ring 52 are the same. Taking the stainless steel inner ring 51 as an example, the stainless steel inner ring 51 can include a first connecting ring plate 511 and a second connecting ring plate 512. The first connecting ring plate 511 and the second connecting ring plate 512 are connected as a whole through a V-shaped ring groove 513. The connection between the V-shaped ring groove 513 and the first connecting ring plate 511 and the second connecting ring plate 512 has an arc transition; the protruding direction of the V-shaped ring groove 513 is from the stainless steel inner ring 51 to the stainless steel outer ring 52 direction;

[0040] When the seal 5 is assembled in the sealing ring groove 4, the V-shaped ring groove 513 on the stainless steel outer ring 52 contacts the side wall of the sealing ring groove 4; the stainless steel inner ring 51 is arranged close to the central air passage, and the stainless steel outer ring 52 is arranged away from the central air passage.

[0041] Based on the above structure, when the seal 5 is assembled in the seal ring groove 4, the end of the graphite ring 53, and the ends of the stainless steel inner ring 51 and the stainless steel outer ring 52 respectively abut against the bottom plate of the seal ring groove 4 and the end of the exhaust pipe on the other side, forming a seal; when the exhaust gas in the central air passage leaks from the connection of the first exhaust pipe 1 and the second exhaust pipe 2, it will first enter the seal ring groove 4 and impact the end face of the stainless steel inner ring 51. Since the first connecting ring plate 511 and the second connecting ring plate 512 of the stainless steel inner ring 51 and the outer ring are both connected by V-shaped ring grooves 513 with a certain elastic deformation, when the stainless steel inner ring 51 is impacted by high-pressure exhaust gas, the stainless steel inner ring 51 will have a tendency to expand outwards, so that the graphite ring 53 and the end of the stainless steel inner ring 51 will contact the two side end faces more tightly, forming a tighter seal. When the high-pressure exhaust gas also drives the stainless steel outer ring 52 to deform, the end of the stainless steel outer ring 52 will also be tightly sealed with the two side ends.

[0042] As an example, the graphite layer in the graphite ring 53 is evenly arranged between the cavities of the stainless steel inner ring 51 and the stainless steel outer ring 52, and fits with the convex part of the V-shaped ring groove 513 in the stainless steel inner ring 51, and fits with the concave part of the V-shaped ring groove 513 in the stainless steel outer ring 52. This can effectively ensure the sealing performance.

[0043] As an example, the locking member 3 can include a high-temperature bolt 31, a high-temperature locknut 32, a high-temperature double-stack self-locking lockwasher 33, and a major-to-minor diameter ratio adjustment sleeve 34; the high-temperature bolt 31 is arranged through the flange 7 at the connection of the first exhaust pipe 1 and the second exhaust pipe 2, the high-temperature locknut 32 is arranged at the end of the high-temperature bolt 31, the major-to-minor diameter ratio adjustment sleeve 34 is sleeved between the high-temperature locknut 32 and the flange 7, and the high-temperature double-stack self-locking lockwasher 33 is arranged at the contact part between the high-temperature locknut 32 and the major-to-minor diameter ratio adjustment sleeve 34.

[0044] Based on the above structure, through the major-to-minor diameter ratio adjustment sleeve 34, ensure that the major-to-minor diameter ratio of the bolt is ≥5 when the two exhaust pipes are connected, preventing seal failure caused by the loosening of the bolt and nut; at the same time, setting the high-temperature double-stack self-locking lockwasher 33 can prevent seal failure caused by the loosening of the bolt and nut.

[0045] As an example, the depth of the seal ring groove 4 is 3.0 - 3.5 mm, the width is 5.0 - 7.5 mm, the gap between the seal 5 and the seal ring groove 4 is 0.5 - 1.0 mm; the thickness of the graphite ring 53 is 3.2 - 4.0 mm; there is a compression amount of 0.2 - 0.5 mm left after the seal 5 is installed in the seal ring groove 4.

[0046] As an example, both the stainless steel inner ring 51 and the stainless steel outer ring 52 are made of 06Cr19Ni10 stainless steel sheets with a thickness of 0.3 mm.

[0047] The high-temperature bolt 31 is made of high-temperature resistant stainless steel 40Cr10Si2Mo - GB / T20878 - 2007 and is quenched and tempered. It has a small expansion coefficient and high heat resistance.

[0048] The double-stack self-locking anti-loosening washer is made of GH2132 high-temperature alloy material.

[0049] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A high-temperature sealing structure of stainless steel graphite rings for a locomotive engine exhaust system, characterized in that: It includes a first exhaust pipe and a second exhaust pipe, the first exhaust pipe and the second exhaust pipe are locked externally by a locking piece, a sealing ring groove is provided in the contact surface of the first exhaust pipe or the second exhaust pipe, a sealing piece that can be deformed under force is provided in the sealing ring groove, and the sealing piece can be deformed along the axial direction of the first exhaust pipe or the second exhaust pipe when affected by leaked exhaust gas.

2. According to claim 1, a high-temperature sealing structure of stainless steel graphite rings for a locomotive engine exhaust system, characterized in that: The sealing ring groove is a ring groove with a rectangular cross section, and the sealing ring groove is located away from the central gas path of the first exhaust pipe and / or the second exhaust pipe.

3. According to claim 2, a high-temperature sealing structure of stainless steel graphite rings for a locomotive engine exhaust system, characterized in that: The sealing member comprises a stainless steel inner ring, a stainless steel outer ring and a graphite ring; the graphite ring is arranged between the stainless steel inner ring and the stainless steel outer ring; the overall thickness of the stainless steel inner ring, the stainless steel outer ring and the graphite ring is adapted to the size of the sealing ring groove.

4. According to claim 3, a high-temperature sealing structure of stainless steel graphite rings for a locomotive engine exhaust system, characterized in that: The stainless steel inner ring is the same as the stainless steel outer ring, and the stainless steel inner ring includes a first connecting ring plate and a second connecting ring plate, and the first connecting ring plate and the second connecting ring plate are connected as a whole through a V-shaped ring groove, and the connection between the V-shaped ring groove and the first connecting ring plate and the second connecting ring plate is an arc transition; the convex direction of the V-shaped ring groove is from the stainless steel inner ring to the stainless steel outer ring.

5. According to claim 4, a high-temperature sealing structure of stainless steel graphite rings for a locomotive engine exhaust system, characterized in that: When the seal is assembled in the sealing ring groove, the V-shaped ring groove on the stainless steel outer ring contacts the side wall of the sealing ring groove; the stainless steel inner ring is arranged close to the central air channel, and the stainless steel outer ring is arranged away from the central air channel.

6. According to claim 5, a high-temperature sealing structure of stainless steel graphite rings for a locomotive engine exhaust system, characterized in that: The graphite layer in the graphite ring is evenly arranged between the cavities of the stainless steel inner ring and the stainless steel outer ring, and fits with the raised portion of the V-shaped ring groove in the stainless steel inner ring, and fits with the recessed portion of the V-shaped ring groove in the stainless steel outer ring.

7. A high temperature sealing structure of stainless steel graphite rings for a locomotive engine exhaust system according to claim 6, characterized in that: The locking part includes a high-temperature bolt, a high-temperature anti-loosening nut, a high-temperature double-stack self-locking anti-loosening washer and a length-to-diameter ratio adjustment sleeve; the high-temperature bolt is arranged through a flange at the connection between the first exhaust pipe and the second exhaust pipe, the high-temperature anti-loosening nut is arranged at the end of the high-temperature bolt, the length-to-diameter ratio adjustment sleeve is sleeved between the high-temperature anti-loosening nut and the flange, and the high-temperature double-stack self-locking anti-loosening washer is arranged on the contact portion between the high-temperature anti-loosening nut and the length-to-diameter ratio adjustment sleeve.

8. According to claim 7, a high-temperature sealing structure of stainless steel graphite rings for a locomotive engine exhaust system, characterized in that: The depth of the sealing ring groove is 3.0-3.5 mm, the width is 5.0-7.5 mm, the gap between the sealing element and the sealing ring groove is 0.5-1.0 mm; the thickness of the graphite ring is 3.2-4.0 mm; and after the sealing element is installed in the sealing ring groove, a compression amount of 0.2-0.5 mm is left.

9. A high temperature sealing structure of stainless steel graphite rings for a locomotive engine exhaust system according to claim 8, characterized in that: The stainless steel inner ring and the stainless steel outer ring are both made of 0.3 mm thick 06Cr19Ni10 stainless steel sheets.

10. A high temperature sealing structure of stainless steel graphite rings for a locomotive engine exhaust system according to claim 9, characterized in that: The high-temperature bolt is made of high-temperature resistant stainless steel 40Cr10Si2Mo-GB / T20878-2007 and is subjected to quenching and tempering treatment. The double-stacked self-locking anti-loosening washer is made of GH2132 high-temperature alloy material.

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