Gas pipeline connecting structure for natural gas engine

Abstract

The utility model relates to the technical field of pipeline connectors, and discloses a gas pipeline connecting structure for a natural gas engine, which comprises a flaring type connector, one end of the flaring type connector is sleeved with a clamping sleeve and is locked through a locking nut, and the butt joint position of the flaring type connector and the clamping sleeve is sealed through an O-shaped ring. And the other end of the flaring type joint is in threaded connection with a connecting screw sleeve to form a gas connecting pipeline. The flaring type connector and the clamping sleeve are connected in a sleeved mode and locked through the locking nut, the butt joint position is sealed through the O-shaped ring, the other end of the flaring type connector and the clamping sleeve are in threaded connection with the connecting threaded sleeve, according to the design, through a multi-sealing structure, the sealing performance of a gas pipeline is effectively enhanced, the gap between the flaring type connector and the clamping sleeve can be filled with the O-shaped ring, gas leakage is prevented, and the service life of the gas pipeline is prolonged. Safe conveying of natural gas in a pipeline is ensured, and the risk of safety accidents such as engine fire caused by gas leakage is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to pipeline joint technical field, concretely is a kind of for natural gas engine gas pipeline connecting structure. BACKGROUND

[0002] Diesel engine is using oil pump to pump diesel from mailbox to fuel injection pump, and then by fuel injection pump pressure delivery to fuel injector and inject into cylinder compression natural combustion, it is a gradual pressure increasing process, and in the gas system of natural gas engine, it is just the opposite, whether CNG, LNG or LPG is stored in gas cylinder, it already has certain pressure, needs pressure reducer to reduce pressure to certain pressure (in the process of pressure reduction, need to absorb heat, generally take engine coolant to warm up), again by fuel control unit electric control pressure regulator or nozzle timing quantitative injection into mixer and air to carry out uniform mixing, mixed gas enters intake pipe again and then burns by spark plug ignition, it is a gradual pressure reducing process.

[0003] In the gas system of natural gas engine, the connection of gas pipeline is unavoidable, and the current gas pipeline connecting piece is designed by referring to the flared joint in the "Automobile Design Standard Data Handbook-Standard Parts", however, in the actual application process, when the traditional pipeline connecting piece meets the connection of high-pressure gas, the joint is often not tightly sealed, and gas leakage faults occur, and combined with the high-temperature environment during engine operation, it is easy to cause engine fire and other safety problems. UTILITARIAN CONTENT

[0004] To solve the technical problems in the background art, the utility model provides a kind of for natural gas engine gas pipeline connecting structure.

[0005] The utility model provides a kind of for natural gas engine gas pipeline connecting structure, including flared joint, one end of flared joint is connected with the sleeve and is locked by lock nut, and the butt joint of flared joint and sleeve is sealed by O-ring, and the other end of flared joint is connected with connecting screw nut to constitute gas connecting pipeline;

[0006] In view of the problem that the traditional gas pipeline connecting piece is prone to not tightly sealed and gas leakage when connecting high-pressure gas, the design adopts multiple sealing and connecting mode, flared joint is connected with sleeve, and then locked by lock nut, and this mechanical connecting mode ensures the close cooperation between the two, which provides the basis for sealing;

[0007] The O-shaped ring plays a key sealing role at the butt joint, can fill the small gap between the flared joint and the sleeve, prevent gas leakage, the flared joint is threadedly connected with the connecting sleeve, and the structure of the whole gas connecting pipeline is further improved, the multiple sealing and connecting structure effectively enhances the sealing property of the gas pipeline, reduces the risk of gas leakage, and guarantees the safety of the natural gas engine operation.

[0008] As a further optimization scheme of the utility model, the flared joint is provided with an annular groove matched with the O-shaped ring at the end away from the connecting sleeve, the O-shaped ring is assembled in the annular groove, and the outer wall of the O-shaped ring is tightly attached to the inner wall of the sleeve;

[0009] The annular groove is designed to better fix and position the O-shaped ring, which is matched with the O-shaped ring, so that the O-shaped ring can be tightly installed in the groove, reducing the displacement and deformation possibility of the O-shaped ring in the working process, and the outer wall of the O-shaped ring is tightly attached to the inner wall of the sleeve, further enhancing the sealing effect;

[0010] When the gas flows in the pipeline, the pressure will act on the O-shaped ring, the annular groove can limit the movement of the O-shaped ring, so that it always maintains close contact with the inner wall of the sleeve, ensuring the reliability of the seal, even in the vibration and high temperature environment generated by the engine operation, gas leakage can be effectively prevented.

[0011] Further, the groove width dimension L1 of the annular groove is 1.5mm, the groove depth dimension L2 is 7.7mm, and the groove positioning dimension L3 is 1.5mm, and the specification of the O-shaped ring is φ15x1.5;

[0012] The precise annular groove size and O-shaped ring specification are the key to ensure the sealing performance, the groove width dimension L1 is 1.5mm, which ensures that the O-shaped ring has a suitable accommodation space in the groove, neither will the O-shaped ring shake in the groove to affect the sealing effect due to excessive width, nor will the O-shaped ring be damaged due to excessive extrusion; the groove depth dimension L2 is 7.7mm, which can make the O-shaped ring fully contact with the inner wall of the sleeve after installation, ensuring the effectiveness of the seal; the groove positioning dimension L3 is 1.5mm, which accurately determines the position of the annular groove on the flared joint, so that the O-shaped ring can be precisely butt jointed with the sleeve after installation; the specification of the O-shaped ring is φ15x1.5, which is matched with the size of the annular groove, and together ensures the tightness and stability of the seal, which can effectively prevent gas leakage in the high pressure environment of the natural gas engine gas pipeline.

[0013] Further, the inner wall of the annular groove is chamfered, and the chamfer R1 is 0.2 mm, which can avoid damage of the O-ring in the installation and use process, the sharp corners may scratch the O-ring when the O-ring is installed into the annular groove, which reduces the sealing performance, the chamfering can make the O-ring more smooth in installation, reduce the damage risk in the installation process, and the flow and pressure change of the fuel gas may cause friction between the O-ring and the inner wall of the annular groove during engine operation, the chamfer can reduce the wear of the O-ring caused by the friction, prolong the service life of the O-ring, further ensure the reliability of the sealing, and prevent fuel gas leakage.

[0014] As a further optimization scheme of the utility model, the ball inner wall is provided inside the end of the sleeve near the flared joint, the O-ring is sleeved outside the flared joint, and the outer wall of the flared joint and the O-ring are in contact with the spherical surface;

[0015] The spherical inner wall of the sleeve, the O-ring and the flared joint form a double sealing structure of spherical sealing and O-ring sealing, the spherical inner wall can be tightly attached to the outer wall of the flared joint and the O-ring, and the special geometric shape of the spherical surface can further block the fuel gas leakage, the spherical sealing can evenly distribute the pressure on the contact surface when the fuel gas pressure acts, and the sealing effect is enhanced, and the double sealing structure can effectively cope with the high-pressure gas in the natural gas engine fuel gas pipeline, and can significantly improve the safety and stability of the pipeline connection even under complex working conditions, and reduce the possibility of fuel gas leakage.

[0016] As a further optimization scheme of the utility model, the outer wall of the flared joint at both ends is provided with external threads M1 and external threads M2, the external threads M1 and the external threads M2 are respectively engaged and connected with the internal threads of the locking nut and the connecting sleeve, and the thread sizes of M1 and M2 are respectively 7 / 8-14UNF-2A and NPT1 / 2;

[0017] The external threads at both ends of the flared joint, i.e. the external threads M1 and the external threads M2, are engaged and connected with the internal threads of the locking nut and the connecting sleeve, which has many advantages, the standardized threaded connection method can be operated conveniently and quickly by maintenance personnel during installation, and the connection and disassembly can be completed without special tools, which improves the work efficiency, and the stability of the threaded connection can ensure the firmness of the entire fuel gas pipeline connection, which can effectively prevent the connection from loosening even under the action of external forces such as vibration during engine operation, reduce the risk of fuel gas leakage caused by loosening of the connection, improve the maintainability and reliability of the equipment, and ensure the normal operation of the natural gas engine.

[0018] As a further optimization scheme of the utility model, the O-ring is a hydrogenated butyl nitrile rubber ring, which has good high-temperature resistance, oil resistance and chemical corrosion resistance;

[0019] The natural gas engine generates high temperature during operation, and the gas may contain some chemicals, so the ordinary rubber ring is easy to age and deform in such an environment, resulting in a decrease in sealing performance, while the hydrogenated nitrile rubber ring can maintain stable performance in a high-temperature environment and is not easy to be eroded by chemicals in the gas, thereby effectively ensuring the sealing effect for a long time, prolonging the service life of the pipeline connecting structure and ensuring the safe operation of the natural gas engine gas pipeline.

[0020] Further, the compression rate of the O-ring is 85%, and the filling rate is 95%, and reasonable compression rate and filling rate are important parameters for the O-ring to exert good sealing performance.

[0021] The compression rate of the O-ring is 85%, so that the O-ring can produce appropriate elastic deformation after installation and tightly fill the gap between the flared joint and the sleeve, effectively preventing gas leakage; and the filling rate is 95%, so that the O-ring can be fully filled in the annular groove, which not only ensures the close cooperation between the O-ring and the annular groove, but also avoids damage caused by excessive extrusion of the O-ring due to excessive filling.

[0022] Such compression rate and filling rate can make the O-ring maintain good elasticity and sealing performance during sealing, and better adapt to the complex working conditions of the natural gas engine gas pipeline, thereby ensuring long-term stable sealing effect.

[0023] The natural gas engine gas pipeline connecting structure has the following beneficial effects:

[0024] (1) The flared joint of the utility model is sleeved with the sleeve and locked by the locking nut, and the butt joint is sealed by the O-ring, and the other end is threadedly connected with the connecting sleeve, so that the multiple sealing structure effectively enhances the sealing performance of the gas pipeline, the O-ring can fill the gap between the flared joint and the sleeve, prevent gas leakage, ensure the safe transportation of natural gas in the pipeline, and reduce the risk of safety accidents such as engine fire caused by gas leakage;

[0025] (2) The annular groove adapted to the O-ring is formed on the flared joint, and the accurate groove width, groove depth and groove positioning size, as well as the round corner treatment of the inner wall, enable the O-ring to be tightly installed in the annular groove and not easy to displace and deform, which further improves the reliability of the sealing, ensures that the O-ring can maintain good sealing performance even if affected by factors such as vibration and high temperature during engine operation, and continuously prevents gas leakage;

[0026] (Three) the sleeve is internally provided with a spherical inner wall near one end of the flared joint, the flared joint and the outer wall of the O-ring are in contact with the spherical surface, realizing double sealing of the spherical surface sealing and the O-ring sealing, the spherical surface sealing can further block gas leakage by using the close-fitting characteristics of the spherical surface, and the sealing effect is significantly enhanced in cooperation with the O-ring sealing, effectively coping with high-pressure gas in the gas pipeline of the natural gas engine, and improving the safety and stability of the pipeline connection.

[0027] Additional aspects and advantages of the present application will be described in part below, some of which will become apparent from the following description, or will be learned from the practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a cross-sectional structure schematic view of the present application;

[0029] Figure 2 is a three-dimensional structure schematic view of the present application;

[0030] Figure 3 is a partial cross-sectional structure schematic view of the flared joint of the present application.

[0031] BRIEF DESCRIPTION OF DRAWINGS: 1, flared joint; 2, O-ring; 3, locking nut; 4, sleeve; 5, connecting screw; 6, annular groove. DETAILED DESCRIPTION

[0032] The embodiments of the present application will be described in detail below, examples of which are represented in the drawings, wherein the same or similar symbols represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present application, and cannot be understood as a limitation on the present application.

[0033] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be direct contact of the first and second features, or indirect contact of the first and second features through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be directly above or obliquely above the first feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature can be directly below or obliquely below the first feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.

[0034] In the gas pipeline system of the natural gas engine, the conventional pipeline connecting piece has the problems of loose sealing, easy to cause gas leakage and other safety hazards when facing high-pressure gas connection. The gas pipeline connecting structure of the present application effectively solves these problems through innovative design, and the specific implementation mode is as follows:

[0035] As Figure 1 and Figure 2 shown, the core component of the gas pipeline coupling structure is the flared joint 1, one end of which is sleeved with the sleeve 4, and this sleeving mode lays the foundation for the close fit between the two. In order to further ensure the stability of the connection, the flared joint 1 and the sleeve 4 are locked by using the locking nut 3. At the joint of the flared joint 1 and the sleeve 4, the O-ring 2 is installed, which plays a key sealing role and can fill the possible small gap between the two to prevent gas leakage. The other end of the flared joint 1 is threadedly connected with the connecting sleeve 5, thereby forming a complete gas connection pipeline. This multiple connection and sealing design ensures the safety of gas transportation from the structure.

[0036] In one embodiment, the dimensions of the flared joint are as follows: SR2 = 10.3 mm, L4 = 6 mm, L5 = 7 mm, L6 = 22 mm, L7 = 46 mm;

[0037] As Figure 3 shown, the flared joint 1 has a ring groove 6 at the end away from the connecting sleeve 5. The ring groove 6 is adapted to the O-ring 2, and the groove width L1 of the ring groove 6 is 1.5 mm. This width can ensure that the O-ring 2 has a suitable accommodation space in the groove and will not shake due to excessive width to affect the sealing effect. The groove depth L2 is 7.7 mm, which ensures that the O-ring 2 can fully contact the inner wall of the sleeve 4 after installation to achieve good sealing. The groove positioning size L3 is 1.5 mm, which accurately determines the position of the ring groove 6 on the flared joint 1, so that the O-ring 2 can be precisely jointed with the sleeve 4 after installation. The O-ring 2 is tightly fitted in the ring groove 6, and its outer wall is tightly attached to the inner wall of the sleeve 4.

[0038] In addition, the inner wall of the ring groove 6 is rounded, and the groove radius R1 is 0.2 mm. This design is very critical. During the installation of the O-ring 2, the round corner can avoid the O-ring 2 being cut by sharp corners, reducing the risk of installation damage. During engine operation, the flow and pressure changes of the gas will cause friction between the O-ring 2 and the inner wall of the ring groove 6. The round corner can reduce the wear of the O-ring 2 caused by this friction, prolong the service life of the O-ring 2, and ensure the reliability of the sealing.

[0039] As Figure 1 shown, the sleeve 4 has a spherical inner wall at the end close to the flared joint 1, and the O-ring 2 is sleeved on the outside of the flared joint 1. The flared joint 1 and the outer wall of the O-ring 2 are both in contact with the spherical surface. This special structure forms a double sealing form of spherical sealing and O-ring sealing.

[0040] The spherical seal utilizes its special geometry to evenly distribute pressure on the contact surface under the action of gas pressure, cooperates with the sealing effect of the O-ring 2, further blocks gas leakage, and even in the high-pressure environment and complex working conditions of the gas pipeline of the natural gas engine, the double-sealing structure can significantly improve the safety and stability of the pipeline connection and effectively reduce the possibility of gas leakage.

[0041] The outer wall of the flared joint 1 at both ends has external threads M1 and external threads M2, respectively, and the sizes of the external threads M1 and the external threads M2 are 7 / 8-14UNF-2A and NPT1 / 2, respectively, which are meshed and connected with the internal threads of the lock nut 3 and the connecting sleeve 5.

[0042] At the same time, the stability of the threaded connection can ensure that the entire gas pipeline is not prone to connection loosening during engine operation, even under the action of external forces such as vibration, effectively reducing the risk of gas leakage caused by connection loosening, and improving the maintainability and reliability of the equipment.

[0043] The O-ring 2 is made of hydrogenated nitrile rubber, which is because this material has good high-temperature resistance, oil resistance and chemical corrosion resistance. The natural gas engine generates high temperature during operation, and the gas may contain chemicals. Ordinary rubber rings are prone to aging and deformation in such an environment, leading to a decline in sealing performance. The hydrogenated nitrile rubber ring can maintain stable performance in a high-temperature environment and is not easily eroded by chemicals in the gas, thereby effectively ensuring the sealing effect for a long time, prolonging the service life of the pipeline connection structure, and ensuring the safe operation of the natural gas engine gas pipeline.

[0044] The compression rate of the O-ring 2 is set to 85%, and the filling rate is 95%. A reasonable compression rate allows the O-ring 2 to produce appropriate elastic deformation after installation, tightly filling the gap between the flared joint 1 and the sleeve 4, effectively preventing gas leakage. A suitable filling rate ensures that the O-ring 2 is fully filled in the annular groove 6, ensuring tight cooperation with the annular groove 6 and avoiding damage caused by excessive compression due to overfilling. Such compression rate and filling rate can make the O-ring 2 maintain good elasticity and sealing performance during the sealing process, and better adapt to the complex working conditions of the natural gas engine gas pipeline.

[0045] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto. Any skilled person in the art can make equivalent substitutions or changes to the technical solutions and concepts of the present application within the scope of the present application, which should be covered within the protection scope of the present application.

Claims

1. A connection structure for a gas pipeline in a natural gas engine, comprising a flared connector (1), characterized in that, One end of the flared connector (1) is fitted with the ferrule (4) and locked by the lock nut (3). The joint between the flared connector (1) and the ferrule (4) is sealed by the O-ring (2). The other end of the flared connector (1) is threaded with a connecting sleeve (5) to form a gas connection pipeline. The flared connector (1) has an annular groove (6) at the end away from the connecting threaded sleeve (5) that is compatible with the O-ring (2). The O-ring (2) is fitted in the annular groove (6), and the outer wall of the O-ring (2) is in close contact with the inner wall of the sleeve (4). The end of the ferrule (4) near the flared connector (1) has a spherical inner wall. The O-ring (2) is fitted on the outside of the flared connector (1), and the outer walls of both the flared connector (1) and the O-ring (2) are in contact with the spherical surface.

2. The gas pipeline connection structure for a natural gas engine according to claim 1, characterized in that, The groove width L1 of the annular groove (6) is 1.5mm, the groove depth L2 is 7.7mm, the groove positioning dimension L3 is 1.5mm, and the O-ring specification is φ15×1.

5.

3. The gas pipeline connection structure for a natural gas engine according to claim 1, characterized in that, The inner wall of the annular groove (6) is rounded, and the groove radius R1 is 0.2mm.

4. The gas pipeline connection structure for a natural gas engine according to claim 1, characterized in that, The outer walls of the two ends of the flared connector (1) are respectively provided with external threads M1 and M2, which are respectively engaged with the internal threads of the locking nut (3) and the connecting sleeve (5).

5. A gas pipeline connection structure for a natural gas engine according to claim 1, characterized in that, The O-ring (2) is a hydrogenated nitrile rubber ring.

6. A gas pipeline connection structure for a natural gas engine according to claim 1, characterized in that, The O-ring (2) has a compression rate of 85% and a filling rate of 95%.

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