Novel valve sealing structure

Abstract

The utility model discloses a novel valve sealing structure, which belongs to the technical field of diesel engines and comprises a rubber ring tightly sleeved on a valve rod, and the rubber ring comprises a sealing part sleeved with a spring ring and a connecting part integrally formed at the lower end of the sealing part and coated with an annular framework; the sealing part of the rubber ring comprises a main lip and an air sealing lip which are arranged along the circumferential direction of the inner wall of the rubber ring, and a plurality of supporting tables which are uniformly arranged at intervals along the circumferential direction of the inner wall of the rubber ring and are positioned between the main lip and the air sealing lip; and the air sealing lip is connected with the connecting part of the rubber ring and is downwards inclined. According to the utility model, the holding force to the valve rod can be increased, moderate lubrication is provided, lubricating oil is effectively prevented from leaking into a combustion chamber or a discharge system, the normal operation of an engine is ensured, the fuel efficiency is improved, the environmental pollution is reduced, and the service life of the engine is prolonged.

Description

Technical Field

[0001] The utility model belongs to the technical field of diesel engines, and particularly relates to a novel valve sealing structure. Background Art

[0002] The valve stem seal is a component used to seal the valve stem of an automobile engine. It plays a vital role in the operation of the automobile engine. It is mainly responsible for providing appropriate lubrication for the valve stem during movement, preventing excessive lubricating oil from leaking into the combustion chamber or exhaust system, causing carbon deposits in the cylinder and affecting engine efficiency. The valve stem seal needs to effectively control the amount of lubricating oil leakage. Excessive leakage can easily cause the engine to burn oil, cause carbon deposits, affect emissions, and increase valve and piston wear. Excessive leakage can easily cause dry friction between the valve and the guide, causing abnormal wear of the valve guide and valve guide, shortening the service life of the engine. However, the leakage of existing valve stem seals is too large, which can easily cause lubricating oil to flow along the valve stem to the valve disc, and then leak into the combustion chamber, causing carbon deposits in the cylinder and affecting engine efficiency.

[0003] Therefore, a new valve sealing structure that can effectively control the leakage of lubricating oil is needed. Utility Model Content

[0004] The purpose of the utility model is to provide a new valve sealing structure, which can increase the clamping force on the valve stem, effectively prevent lubricating oil from leaking into the combustion chamber or exhaust system while providing moderate lubrication, thereby ensuring the normal operation of the engine while improving fuel efficiency, reducing environmental pollution, and extending the service life of the engine.

[0005] In order to achieve the above purpose, the technical solution adopted by the present utility model is:

[0006] A new valve sealing structure includes a rubber ring tightly fitted on a valve stem, the rubber ring including a sealing portion with a spring ring fitted on the outside and a connecting portion integrally formed at the lower end of the sealing portion and covered with an annular skeleton on the outside; the sealing portion of the rubber ring includes a main lip and an air sealing lip circumferentially arranged along its inner wall, and a plurality of support platforms evenly spaced along its inner wall circumferentially and located between the main lip and the air sealing lip, the connecting portion of the air sealing lip and the rubber ring being connected and tilted downward.

[0007] A further improvement of the technical solution of the present utility model is that the connecting portion of the rubber ring includes a step arranged along the circumference of its inner wall and a plurality of assembly grooves located below the step and evenly spaced vertically, wherein the assembly groove located at the top is connected to the air sealing lip through the step.

[0008] The further improvement in the technical scheme of the utility model lies in that: the angle of the gas sealing lip inclining downward is α, 17°≤α≤40°; the main lip is radially raised along the sealing part of the rubber ring and is provided with a round corner with a radius R1, 0.15mm≤R1≤0.35mm.

[0009] The further improvement in the technical scheme of the utility model lies in that: the lower end of the annular framework is inwardly reduced in diameter, the inner edge of the upper end port is circumferentially provided with a clamping table, and the inner edge of the lower end port is circumferentially provided with a clamping seat matched with the bottom of the rubber ring.

[0010] The further improvement in the technical scheme of the utility model lies in that: the annular framework is inwardly reduced in diameter at 1 / 2 of the height thereof.

[0011] The further improvement in the technical scheme of the utility model lies in that: the radius R1 of the round corner of the main lip is 0.25mm; and the sealing part of the rubber ring is circumferentially and uniformly provided with four supporting tables along the inner wall thereof.

[0012] Thanks to the above technical scheme, the utility model has the following technical progress:

[0013] The valve sealing structure can increase the holding force of the rubber ring on the valve rod, effectively prevent the lubricating oil from leaking into the combustion chamber or the exhaust system while providing moderate lubrication for the valve rod, ensure the normal operation of the engine, improve the fuel efficiency, reduce environmental pollution, and prolong the service life of the engine.

[0014] The sealing part of the rubber ring comprises the main lip, the gas sealing lip and the supporting tables, the supporting tables are circumferentially and uniformly arranged along the inner wall of the rubber ring and located between the main lip and the gas sealing lip, the leakage of the rubber ring is related to the negative pressure borne by the rubber ring, the supporting tables can effectively reduce the pressure deformation of the main lip, so as to position and support the main lip, thereby reducing the influence of the negative pressure generated during the intake on the main lip.

[0015] The main lip is radially raised along the sealing part of the rubber ring and is provided with a round corner with a radius R1, 0.15mm≤R1≤0.35mm, preferably R1=0.25mm, the radial raising of the main lip can increase the holding force of the rubber ring on the valve rod, the size of the round corner of the main lip is related to the leakage, compared with the main lip of the existing rubber ring, the round corner of the main lip of the utility model is smaller, can effectively reduce the oil film thickness generated between the main lip and the valve rod, thereby effectively reducing the leakage during the reciprocating movement of the valve rod.

[0016] The air sealing lip adopted in the utility model is connected with the connecting part of the rubber ring and is arranged to be tilted downward. The downward tilt angle of the air sealing lip is α, 17°≤α≤40°. When positive pressure is generated during the exhaust process, the downward tilted air sealing lip is subjected to the positive pressure of the airflow to increase the holding force on the valve stem, prevent high-temperature exhaust gas from impacting the main lip, reduce the impact of high-temperature airflow on the main lip, and at the same time ensure that the main lip maintains a stable sealing state when the pressure changes.

[0017] The connecting portion of the rubber ring adopted in the present invention includes a step arranged along the circumference of its inner wall and a plurality of assembly grooves located below the step and evenly spaced vertically. The assembly groove at the top is connected with the air sealing lip through the step, so that the assembly height of the rubber ring is increased, which can effectively prevent the rubber ring from falling off due to heat. The setting of the step can not only effectively prevent the annular skeleton from being deformed too much, but also help to disperse the stress generated during assembly, avoid stress concentration and damage to the rubber ring. At the same time, the step serves as a positioning surface during assembly, ensuring that the rubber ring can be accurately positioned during installation, which is crucial to ensuring sealing performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the valve sealing structure of the utility model;

[0019] Among them, 1. rubber ring, 2. ring frame, 2-1. card table, 2-2. card seat, 3. spring ring, 4. main lip, 5. support platform, 6. air sealing lip, 7. step, 8. assembly groove. DETAILED DESCRIPTION

[0020] The present invention is further described in detail below with reference to the embodiments:

[0021] like Figure 1 As shown, the utility model provides a new valve sealing structure, including a rubber ring 1 tightly mounted on the valve stem, the rubber ring 1 including a sealing portion and a connecting portion integrally formed with the sealing portion, the outer portion of the sealing portion is sleeved with a spring coil 3, the connecting portion is located at the lower end of the sealing portion, and the outer portion is covered with an annular skeleton 2. The sealing portion of the rubber ring 1 includes a main lip 4, an air-sealing lip 6, and a plurality of support platforms 5. The main lip 4 and the air-sealing lip 6 are both arranged along the inner wall circumference of the sealing portion of the rubber ring 1, and the plurality of support platforms 5 are evenly spaced along the inner wall circumference of the sealing portion of the rubber ring 1, and the plurality of support platforms 5 are located between the main lip 4 and the air-sealing lip 6. Preferably, the sealing portion of the rubber ring 1 is evenly spaced along its inner wall circumference. The air-sealing lip 6 is arranged to be tilted downward, and its downward tilt angle is α, 17°≤α≤40°.

[0022] Since the leakage of the rubber ring 1 is related to the negative pressure it withstands, when the cylinder is intaken, the intake valve opens, and high-pressure air rushes into the cylinder, generating a vacuum effect on the lower end of the rubber ring 1 through the gap between the valve stem and the valve guide. At this time, the air sealing lip 6 does not have a reverse air sealing effect, and the vacuum negative pressure will eventually act on the main lip 4. The uneven negative pressure will cause the main lip 4 to be compressed and deformed, so that the sealing belt between the main lip 4 and the valve stem has an irregular curved surface on the circumference, making the seal unreliable. When the valve stem reciprocates, it is easy to cause increased oil leakage. Therefore, a support platform 5 structure is added between the main lip 4 and the air sealing lip 6 to reduce the compressive deformation of the main lip 4, so as to achieve the positioning and support of the main lip 4, thereby reducing the influence of the negative pressure generated during intake on the main lip 4.

[0023] The leakage of the rubber ring 1 is also related to the positive pressure it withstands. When the cylinder is exhausted, part of the airflow rushes to the lower end of the rubber ring 1 through the gap between the valve stem and the valve guide, forming positive pressure, which impacts the main lip 4 on the rubber ring 1, which can easily cause the main lip 4 to have a reduced clamping force on the valve stem, making the seal unreliable and increasing the amount of oil leakage. Therefore, a downward-inclined air sealing lip 6 is provided below the main lip 4. When positive pressure is generated during the exhaust process, the downward-inclined air sealing lip 6 is subjected to the positive pressure of the airflow to increase the clamping force on the valve stem, prevent high-temperature exhaust gas from impacting the main lip 4, reduce the influence of high-temperature airflow on the main lip 4, and at the same time ensure that the main lip 4 maintains a stable sealing state when the pressure changes.

[0024] The connecting part of the rubber ring 1 is connected with the air sealing lip 6 of its sealing part. Specifically, the connecting part of the rubber ring 1 includes a step 7 and a plurality of assembly grooves 8. The step 7 is circumferentially arranged along the inner wall of the connecting part of the rubber ring 1. The plurality of assembly grooves 8 are located below the step 7 and are evenly spaced vertically. The assembly groove 8 at the top is connected with the air sealing lip 6 of the sealing part of the rubber ring 1 through the step 7, thereby increasing the assembly height of the rubber ring 1 and effectively preventing the rubber ring 1 from falling off due to heat. The setting of the step 7 can not only effectively prevent the annular skeleton 2 from being deformed too much, but also help to disperse the stress generated during assembly, avoiding stress concentration causing damage to the rubber ring 1. At the same time, the step 7 serves as a positioning surface during assembly to ensure that the rubber ring 1 can be accurately positioned during installation, which is crucial to ensuring sealing performance.

[0025] The main lip 4 is radially raised along the sealing part of the rubber ring 1 and is provided with a fillet with a radius R1, 0.15mm≤R1≤0.35mm. Preferably, the fillet radius R1 of the main lip 4 is R1=0.25mm. The radial bulge of the main lip 4 can increase the clamping force of the rubber ring 1 on the valve stem, and the size of the fillet of the main lip 4 is related to the leakage amount. The larger the fillet, the greater the flow rate, and the smaller the fillet, the smaller the flow rate. Compared with the main lip of the existing rubber ring, the main lip 4 of the utility model has a smaller fillet, which can effectively reduce the thickness of the oil film generated by the main lip 4 and the valve stem, thereby effectively reducing the leakage amount during the reciprocating motion of the valve stem.

[0026] The lower end of the annular skeleton 2 is tapered inwards, and a clamping platform 2-1 is circumferentially provided on the inner edge of its upper port, and a clamping seat 2-2 adapted to the bottom of the rubber ring 1 is circumferentially provided on the inner edge of its lower port. Preferably, the annular skeleton 2 is tapered inwards from 1 / 2 of its height.

[0027] Therefore, the valve sealing structure of the present invention can increase the clamping force of the rubber ring 1 on the valve stem, provide moderate lubrication for the valve stem, and effectively prevent lubricating oil from leaking into the combustion chamber or exhaust system, thereby ensuring the normal operation of the engine while improving fuel efficiency, reducing environmental pollution, and extending the service life of the engine.

[0028] It is understood that the present invention is described by way of certain embodiments, and those skilled in the art will appreciate that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. Furthermore, under the guidance of the present invention, these features and embodiments may be modified to suit specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are intended to be protected by the present invention.

Claims

1. A new valve sealing structure, characterized by: The invention comprises a rubber ring (1) tightly fitted on a valve stem, the rubber ring (1) comprising a sealing portion with a spring ring (3) on the outside and a connecting portion integrally formed at the lower end of the sealing portion and covered with an annular skeleton (2) on the outside; the sealing portion of the rubber ring (1) comprises a main lip (4) and an air sealing lip (6) arranged along the circumference of its inner wall, and a plurality of support platforms (5) evenly spaced along the circumference of its inner wall and located between the main lip (4) and the air sealing lip (6); the air sealing lip (6) and the connecting portion of the rubber ring (1) are connected and arranged downwardly tilted; the main lip (4) is raised along the radial direction of the sealing portion of the rubber ring (1) and is provided with a The radius of the fillet is R1, 0.15mm≤R1≤0.35mm; the lower end of the annular skeleton (2) is tapered inward, and a clamping platform (2-1) is circumferentially provided on the inner edge of the upper port, and a clamping seat (2-2) adapted to the bottom of the rubber ring (1) is circumferentially provided on the inner edge of the lower port; the annular skeleton (2) is tapered inward from 1 / 2 of its height; the connecting portion of the rubber ring (1) includes a step (7) arranged along the circumference of its inner wall and a plurality of assembly grooves (8) located below the step (7) and evenly spaced vertically, wherein the assembly groove (8) located at the top is connected to the air sealing lip (6) through the step (7).

2. A novel valve sealing structure according to claim 1, characterized in that: The downwardly inclined angle of the air sealing lip (6) is α, 17°≤α≤40°.

3. A novel valve sealing structure according to claim 2, characterized in that: The fillet radius R1 of the main lip (4) is 0.25 mm; and four support platforms (5) are evenly spaced along the circumference of the inner wall of the sealing portion of the rubber ring (1).

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