Semi-X-shaped rubber ring sealing structure of nodular cast iron pipe

Abstract

The utility model discloses a semi-X-shaped rubber ring sealing structure of a nodular cast iron pipe, and relates to the technical field of socket fit sealing of nodular cast iron pipes. The sealing ring comprises an integrally-formed semi-X-shaped rubber ring, one end of the periphery of the rubber ring is provided with a protruding annular positioning clamping block, the other end of the periphery of the rubber ring is provided with a first sealing part, and a straight part is arranged between the first sealing part and the positioning clamping block; the end, close to the positioning clamping block, of the inner circumference of the rubber ring is an inclined part, an extrusion part is arranged in the middle of the inner circumference, and the vertical distance from the inner circumference of the rubber ring to the straight part is gradually increased from the end where the positioning clamping block is located to the extrusion part. A second sealing part is arranged at one end, far away from the positioning fixture block, of the inner circumference of the rubber ring, one side of the section of the second sealing part and the first sealing part is arc-shaped, and arc-shaped grooves are formed between the second sealing part and the first sealing part and between the second sealing part and the extrusion part respectively; the nodular cast iron pipeline is reasonable in section appearance design, the sealing reliability of the nodular cast iron pipeline in certain high-pressure, high-temperature and dynamic environments is improved, and the requirement for high-temperature hot water conveying in the heating industry can be met.

Description

TECHNICAL FIELD

[0001] The utility model relates to ductile cast iron pipe socket joint sealing technical field, concretely is a kind of half "X" shape rubber ring sealing structure of ductile cast iron pipe. BACKGROUND

[0002] For ductile cast iron pipe socket joint sealing, currently all adopt rubber ring as sealing mode, different sealing rings with different cross-sectional shapes are designed for different interfaces, but with the improvement of people's living standards, central heating develops faster and faster, thus ductile cast pipe, as an excellent water conveying pipe material, is favored by the heating industry, but heating needs to transport high-temperature water, and usually ductile cast iron pipe transports normal-temperature water, thus higher requirements are put forward for rubber sealing of cast pipe socket joint.

[0003] Due to the influence of shrinkage rate of molten iron, the size of socket and spigot of ductile cast iron pipe will fluctuate within the required tolerance range, thus when socket joint of ductile cast pipe is carried out, maximum gap G max And minimum gap G min Exist, when rubber ring adapts to socket joint, there will be maximum compression ratio and minimum compression ratio, at this time, appropriate rubber ring size is needed to ensure that sealing will not fail, if compression ratio is too small, sealing surface and rubber ring do not have large force, failure is possible, if compression ratio is too large, rubber ring may be damaged, leading to failure, especially in high-temperature condition, rubber ring ages faster, elasticity decreases, and brittleness increases, at this time, if higher compression ratio (above 38%) is maintained, rubber ring will crack and peel due to performance decline, thus leading to entire sealing failure.

[0004] In addition, rubber will undergo thermal aging at high temperature, leading to changes in its physical and chemical properties. Over time, the elasticity, strength and toughness of the rubber may decrease, making the material more susceptible to cracking at the tip or in areas of stress concentration, however, in order to increase friction, the existing rubber ring usually adopts full flat structure with more surface contact, for example, the fish tail-shaped rubber ring shown in Figure 1 The outer ring of the pipe socket, i.e. the full flat wall surface, also brings the problem of shorter service life than expected for high-temperature environment application.

[0005] In summary, under the new requirements of the heating industry for ductile cast pipe, a rubber ring that can adapt to high-temperature water and can normally seal is urgently needed. UTILITY MODEL CONTENTS

[0006] The utility model aims at providing a half "X" shape rubber ring sealing structure of ductile cast iron pipe to solve the problems raised in the above background technology.

[0007] To achieve the above object, the utility model provides the following technical scheme: A half "X" shape rubber ring sealing structure of nodular cast iron pipe, the half "X" shape rubber ring is integrally formed, and the outer periphery one end is the annular positioning clamping block of protruding, is used for clamping in the positioning groove of pipeline socket near end part, the other end is equipped with first sealing part, and it is the flat portion that cooperates with the inner wall of pipeline socket between the positioning clamping block, the inner periphery of half "X" shape rubber ring near the one end of positioning clamping block is the inclined portion, and is equipped with extrusion portion in the inner periphery middle part, and the vertical distance of the inner periphery of half "X" shape rubber ring to flat portion gradually increases from the end of positioning clamping block to extrusion portion, and the inner periphery of half "X" shape rubber ring away from the one end of positioning clamping block is equipped with second sealing part, and the cross section of first sealing part away from the side of positioning clamping block is arc, and it is equipped with arc-shaped recess between first sealing part and extrusion portion respectively.

[0008] Preferably, when the half "X" shape rubber ring is in working state, the inclined portion, the extrusion portion and the second sealing portion near the inner periphery of the half "X" shape rubber ring are in close contact with the pipeline socket under pressure, and the flat portion and the first sealing portion near the outer periphery of the half "X" shape rubber ring are in close contact with the pipeline socket under pressure; the arc-shaped recess between the first sealing portion and the second sealing portion is used to disperse the force to the first sealing portion and the second sealing portion on both sides after being impacted by the fluid, so as to increase the pressure of the first sealing portion and the second sealing portion on the pipeline socket and the pipeline socket respectively.

[0009] Preferably, the tangent line of the first sealing portion near the flat portion is less than 45° with the flat portion.

[0010] Preferably, the arc surface of the first sealing portion and the second sealing portion corresponds to an obtuse angle.

[0011] Preferably, the material of the half "X" shape rubber ring is EPDM.

[0012] Preferably, the thickness of the half "X" shape rubber ring at the second sealing portion is less than the extrusion portion.

[0013] Compared with the prior art, the utility model has the beneficial effects that:

[0014] 1. The semi-X-shaped rubber ring sealing structure of this ductile iron pipe has a reasonable cross-sectional design. The sharp fishtail part in the original structure is replaced with the first sealing part, reducing the possibility of tip failure and stress failure. This ensures that the sealing ring can maintain its performance after long-term use and has a long service life. At the same time, the addition of a second sealing part provides a larger contact area, improving the sealing ability with the mating surface and effectively preventing fluid leakage. Furthermore, due to the wavy variable compression ratio of the semi-X-shaped rubber ring, this characteristic allows it to function within the tolerance range of the socket clearance. With excellent sealing performance, wear resistance, and anti-aging properties, the sealing reliability of ductile iron pipes is improved under certain high-pressure, high-temperature, or dynamic environments, making it suitable for various complex working conditions.

[0015] 2. The semi-X-shaped rubber ring sealing structure of this ductile iron pipe can better resist deformation under pressure and maintain its sealing performance, especially in high-pressure environments. It can also provide sealing in multiple directions, making it suitable for applications involving bidirectional pressure and tension. Its semi-X geometry can disperse the pressure acting on its surface, thereby reducing wear and improving durability. The one-piece molded rubber ring does not distinguish between soft and hard rubber, making the installation and replacement of the sealing ring relatively simple, reducing maintenance time and costs. The semi-X-shaped structure can also effectively absorb impact and vibration, making the pipe socket assembly process more stable and absorbing some impact energy. The semi-X-shaped design also helps prevent dust and impurities from entering the sealing area, which is beneficial to improving the cleanliness of the system. In addition, this structure is relatively simple in shape and low in cost, which can reduce maintenance and replacement costs in the long term. Attached Figure Description

[0016] Figure 1 A schematic cross-sectional view of an existing fishtail-shaped rubber ring sealing structure;

[0017] Figure 2 This is a cross-sectional schematic diagram of the semi-X-shaped rubber ring sealing structure of this utility model;

[0018] Figure 3 for Figure 2 A schematic diagram of one working state of the structure shown.

[0019] In the diagram: 1. Pipe socket; 2. Pipe spigot; 3. Half "X" shaped rubber ring; 31. Positioning block; 32. Extrusion part; 33. First sealing part; 34. Second sealing part. Detailed Implementation

[0020] Due to the characteristics of the ring structure, the cross-sectional shape of the rubber ring is the same on all planes passing through the center line of the ring. Therefore, the following description is for convenience and will be referred to as such. Figures 1 to 3 The cross-section is used as a reference, and this cross-section can represent the structural features of this utility model.

[0021] Referring to Figure 1 , the tail of the existing STD rubber ring is fish-tail-shaped, when the pipeline transports water, the water will generate pressure to compress the fish-tail-shaped structure of the tail of the rubber ring, so as to make the sealing more stable, but due to the demand of the heating industry for transporting high-temperature water, this structure gradually has some problems, including the service life and sealing failure mentioned in the above background art, therefore, the utility model provides a semi-"X" shaped rubber ring sealing structure of a ductile iron pipe, referring to Figure 2 , the semi-"X" shaped rubber ring 3 is integrally formed, one end of the outer periphery thereof is a protruding annular positioning clamping block 31, which is used for clamping in the positioning groove of the proximal end of the pipe socket 1, the other end is provided with a first sealing portion 33, and the portion between the positioning clamping block 31 and the first sealing portion 33 is a flat portion matched with the inner wall of the pipe socket 1; the inner periphery of the semi-"X" shaped rubber ring 3 is inclined at one end close to the positioning clamping block 31, and a pressing portion 32 is arranged in the middle of the inner periphery, the vertical distance from the inner periphery of the semi-"X" shaped rubber ring 3 to the flat portion gradually increases from the end of the end where the positioning clamping block 31 is located to the pressing portion 32; the inner periphery of the semi-"X" shaped rubber ring 3 is provided with a second sealing portion 34 at one end away from the positioning clamping block 31, and the cross section of the first sealing portion 33 away from the side of the positioning clamping block 31 is arc-shaped, and arc-shaped grooves are arranged between the first sealing portion 33 and the pressing portion 32 and the second sealing portion 34 respectively.

[0022] The tail presents a crossed semi-"X" shape, so that the sealing ring can effectively self-adjust when subjected to pressure, increase the contact area, the structure has two sealing lips, can form double sealing, and is helpful to improve the overall sealing performance and improve the sealing effect; specifically, referring to Figure 3 , when the semi-"X" shaped rubber ring 3 is in a working state, the inclined portion, the pressing portion 32 and the second sealing portion 34 close to one side of the inner periphery of the semi-"X" shaped rubber ring 3 are in close contact with the pipe socket 1 under pressure, and the flat portion and the first sealing portion 33 close to one side of the outer periphery of the semi-"X" shaped rubber ring 3 are in close contact with the pipe socket 1 under pressure, thereby providing good sealing effect; in addition, the arc-shaped grooves between the first sealing portion 33 and the second sealing portion 34 are used to disperse the force to the first sealing portion 33 and the second sealing portion 34 on both sides after being subjected to fluid impact force, so as to increase the pressure of the two on the pipe socket 1 and the pipe socket 2 respectively, so that the semi-"X" shaped rubber ring 3 has good self-adjusting ability, can automatically adjust the sealing state according to the change of pressure, under the double action of water pressure and the elastic restoring force of the rubber ring itself, the rubber ring and the matching surface will generate a large pressure, so that the rubber ring and the matching surface generate a large friction force, due to the existence of the friction force, the phenomenon that the greater the water pressure, the better the sealing effect will occur, and it can also adapt to dynamic pressure or temperature change, and ensure that the sealing effect is always good.

[0023] Due to the fact that the socket and spigot of the ductile cast iron pipe are both cast, the size of the socket and spigot will fluctuate within the required tolerance range due to the shrinkage of the molten iron, and thus when the socket and spigot of the ductile cast iron pipe are matched, the maximum gap G max and the minimum gap G min exist, and the rubber ring will have a maximum compression ratio and a minimum compression ratio when it is adapted to the matching of the socket and spigot, and an excessively large compression ratio will accelerate the aging of the rubber ring at high temperatures, reduce the elasticity and increase the brittleness, and thus cause the rubber ring to fail, and the tail of the rubber ring of the utility model is a half "X" structure, and when the rubber ring is compressed during the matching of the socket and spigot, the compression ratio will be in a wave shape, and this feature enables the rubber ring to function within the matching tolerance range of the socket and spigot, and the structure design enables the sealing ring to maintain stable sealing performance in a dynamic environment.

[0024] Taking the socket and spigot matching part of a DN300 specification ductile cast iron pipe as an example, the half "X" shaped rubber ring sealing structure of the utility model is adopted, the gap of the socket and spigot matching of the DN300 pipe is a maximum gap G=15mm and a minimum gap G=12mm, and the maximum compression ratio of the rubber ring is about 38% and the minimum compression ratio is about 27% after calculation, and thus in the face of complex high temperature water working conditions, the half "X" shaped rubber ring always has a relatively appropriate compression ratio to ensure the sealing of the pipe when the socket and spigot matching gap G is at the maximum and the minimum.

[0025] In a more preferred embodiment, the tangent line of the first sealing part 33 close to one end of the straight part and the straight part form an angle less than 45°, and more preferably, the tangent line is collinear with the straight part, so that the sharp end failure phenomenon can be better reduced.

[0026] In a more preferred embodiment, the central angles of the arc surfaces of the first sealing part 33 and the second sealing part 34 are both obtuse angles, and compared with acute angles or right angles, this structure has more convex parts, is better in self-adjustment and wave-shaped compression ratio, and has a thicker connection part between the sealing part and the main body structure and better structural durability compared with acute angles.

[0027] In a more preferred embodiment, the material of the half "X" shaped rubber ring 3 is EPDM rubber, which has the characteristics of high temperature resistance and aging resistance, and of course, other specific materials can be used as long as they meet the characteristics of high temperature resistance and aging resistance.

[0028] In a more preferred embodiment, the thickness of the half "X" shaped rubber ring 3 at the second sealing part 34 is less than that of the extrusion part 32, and in the use process, the pipe spigot 2 will preferentially contact the inclined part and the extrusion part 32, and the extrusion and wear of the second sealing part 34 are smaller, which is beneficial to improve the durability.

[0029] Meanwhile, the half "X" structure also has various advantages, compared with the previous structure, it has a larger contact area, improves the sealing ability with the mating surface, effectively prevents fluid leakage, the half "X" shape can provide sealing in multiple directions, is suitable for bidirectional pressure and tension application scenarios, the half "X" structure can better resist deformation when being pressed, maintains its sealing performance, especially in high pressure environment, the arc-shaped geometry of the half "X" structure can disperse the pressure acting on its surface, thereby reducing wear and improving durability, the integrally formed rubber ring has no hard and soft rubber, so that the installation and replacement of the sealing ring are relatively simple, maintenance time and cost are reduced, the half "X" structure can also effectively absorb impact and vibration, the pipe socket assembly process is more stable, and part of impact energy can be absorbed, the shape reduces the possibility of tip failure and stress failure, can ensure that the sealing ring can maintain performance after long-term use, the half "X" design also helps to prevent dust and impurities from entering the sealing area, improves the cleanliness of the system, in addition, the structure shape is relatively simple, the cost is low, and the long-term use can reduce maintenance and replacement cost.

[0030] The above is only the preferred embodiment of the present application, but the protection scope of the present application is not limited to this, any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be limited by the protection scope defined by the claims.

[0031] The not detailed part of the present application is the known technology of the person skilled in the art.

Claims

1. A semi-"X" shaped rubber ring sealing structure for ductile iron pipes, characterized in that: The semi-X-shaped rubber ring (3) is integrally formed. One end of its outer circumference is a raised annular positioning block (31) for locking in the positioning groove near the end of the pipe socket (1). The other end is provided with a first sealing part (33), which is a straight part that cooperates with the inner wall of the pipe socket (1) between it and the positioning block (31). The end of the inner circumference of the semi-X-shaped rubber ring (3) near the positioning block (31) is an inclined part, and a pressing part (32) is provided in the middle of the inner circumference. The vertical distance from the inner circumference of the semi-X-shaped rubber ring (3) to the straight part gradually increases from the end of the positioning block (31) to the pressing part (32). The end of the inner circumference of the semi-X-shaped rubber ring (3) away from the positioning block (31) is provided with a second sealing part (34). The cross-section of the semi-X-shaped rubber ring (3) and the side away from the positioning block (31) are both arc-shaped, and arc-shaped grooves are provided between the semi-X-shaped rubber ring (3) and the first sealing part (33) and the pressing part (32).

2. The semi-X-shaped rubber ring sealing structure for a ductile iron pipe according to claim 1, characterized in that: When the semi-X-shaped rubber ring (3) is in working condition, the inclined part, the squeezing part (32) and the second sealing part (34) are pressed on the side of the inner circumference of the semi-X-shaped rubber ring (3) and are in close contact with the pipe socket (2), while the straight part and the first sealing part (33) are pressed on the side of the outer circumference of the semi-X-shaped rubber ring (3) and are in close contact with the pipe socket (1). The arc groove between the first sealing part (33) and the second sealing part (34) is used to disperse the force to the first sealing part (33) and the second sealing part (34) on both sides after being subjected to fluid impact force, so as to increase the pressure of the two on the pipe socket (1) and the pipe socket (2) respectively.

3. The semi-X-shaped rubber ring sealing structure for a ductile iron pipe according to claim 1, characterized in that: The angle between the tangent of the first sealing part (33) near the straight part and the straight part is less than 45°.

4. The semi-X-shaped rubber ring sealing structure for a ductile iron pipe according to claim 1, characterized in that: The central angles corresponding to the arc surfaces of the first sealing part (33) and the second sealing part (34) are both obtuse angles.

5. The semi-X-shaped rubber ring sealing structure for a ductile iron pipe according to claim 1, characterized in that: The material of the semi-X-shaped rubber ring (3) is EPDM rubber.

6. The semi-X-shaped rubber ring sealing structure for a ductile iron pipe according to claim 1, characterized in that: The thickness of the semi-X-shaped rubber ring (3) at the second sealing part (34) is less than that of the extrusion part (32).

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