CN113864543A

CN113864543A - Diesel engine high pressure fuel pipe ball head sealing structure

Info

Publication number: CN113864543A
Application number: CN202111337553.2A
Authority: CN
Inventors: 黄海华; 刘海珍; 王伟晓; 杨松; 杨耀
Original assignee: KUNSHAN JIANGJIN MACHINERY CO Ltd
Current assignee: KUNSHAN JIANGJIN MACHINERY CO Ltd
Priority date: 2021-11-10
Filing date: 2021-11-10
Publication date: 2021-12-31

Abstract

The invention provides a ball head sealing structure of a high-pressure oil pipe of a diesel engine, which enables the connection between the high-pressure oil pipes to be stable and reliable and ensures the long-term sealing effect. It includes: the male head is provided with a stud structure with a front projection, the front end of the stud structure comprises a cone-shaped closing-in transition part and a ball head tail end, the cone-shaped closing-in transition part projects forwards at the center of the front end of the stud structure, the ball head tail end projects forwards at the tail end face of the cone-shaped closing-in transition part, the starting part of the ball head tail end and the tail end face of the cone-shaped closing-in transition part are in seamless connection, the front end of the ball head tail end is a plane ending end, and the ball head tail end is specifically a section of annular spherical arc with the front projection in the thickness direction; the female head comprises a guide central hole and an inwards concave central conical surface, the inwards concave central conical surface is arranged in front of the guide central hole in the axial direction and is arranged coaxially, the inwards concave central conical surface is a conical surface which is closed from back to front, and the guide central hole is an internal thread hole.

Description

Diesel engine high pressure fuel pipe ball head sealing structure

Technical Field

The invention relates to the technical field of oil pipe joints, in particular to a ball head sealing structure of a high-pressure oil pipe of a diesel engine.

Background

When the high-pressure oil pipe of the diesel engine is assembled, the male head and the female head are required to be assembled in a butt joint mode, due to the fact that the high-pressure oil pipe is adopted, the existing method of filling a sealing contact gap through a gasket only through threaded connection or only adding the gasket cannot withstand high-pressure impact, the high-pressure impact is prone to leakage in the high-pressure environment, and therefore a sealing assembly structure suitable for the high-pressure oil pipe is urgently needed to be found.

Disclosure of Invention

Aiming at the problems, the invention provides a ball head sealing structure of a high-pressure oil pipe of a diesel engine, which enables the connection between the high-pressure oil pipes to be stable and reliable and ensures the long-term sealing effect.

Diesel engine high pressure fuel pipe bulb seal structure, its characterized in that, it includes:

the male head is provided with a stud structure with a front projection, the front end of the stud structure comprises a cone-shaped closing-in transition part and a ball head tail end, the cone-shaped closing-in transition part projects forwards from the center of the front end of the stud structure, the ball head tail end projects forwards from the tail end face of the cone-shaped closing-in transition part, the starting part of the ball head tail end and the tail end face of the cone-shaped closing-in transition part are in seamless connection, the front end of the ball head tail end is a plane end stop end, and the ball head tail end is specifically a section of annular spherical arc with a thickness direction projecting forwards;

the female head comprises a guiding central hole and an inwards concave central conical surface, the inwards concave central conical surface is arranged in front of the guiding central hole in the axial direction and is arranged coaxially, the inwards concave central conical surface is a conical surface which is closed from back to front, and the guiding central hole is an internal thread hole;

the stud structure is in threaded connection with the guide center hole, and the annular spherical arc at the tail end of the ball head and the concave center conical surface form a tangent annular sealing surface which is arranged in a clinging manner.

It is further characterized in that:

the conical gasket is arranged along the concave central conical surface in a copying mode, the outer wall of the conical gasket is arranged in a manner of clinging to the concave central conical surface, the annular spherical arc at the tail end of the ball head is clung to the corresponding position of the inner wall of the conical gasket to form a sealing surface, when the sealing surface leaks, only the conical gasket needs to be replaced, the conical gasket is made of soft materials, the conical gasket can be suitable for the tight contact of the convex peak and the valley of the damaged sealing surface, and the medium leakage is prevented;

a stopping groove is formed in the rear end of the stud structure, a sealing ring is sleeved in the stopping groove, a rear-end inner ring groove is formed in the position, facing the stopping groove of the stud structure, of the guide center hole, and the outer wall of the sealing ring is arranged in a manner of being tightly attached to the rear-end inner ring groove, so that the sealing of the connection tail end is ensured;

the front end of the stud structure is provided with an alignment cylindrical ring surface, and the front end of the guide central hole is provided with a transition conical surface, so that the stud and the guide central hole are accurately and reliably axially positioned;

the taper of the closing-in transition part of the conical table is 58 degrees, the taper of the concave central conical surface is 60 degrees, the initial part of the tail end of the ball head is in tangent connection with the tail end of the closing-in transition part of the conical table, so that the annular spherical arc of the tail end of the ball head is tightly attached to the concave central conical surface to form a tangent annular sealing surface;

the roughness of the annular spherical arc at the tail end of the ball head and the roughness of the concave central conical surface reach Ra0.4.

After the technical scheme is adopted, the thread fastening seal and the tangent annular seal surface are arranged between the male head and the female head, the seal coaxiality of the structure is good, the seal is ensured to be stable and reliable, the connection between high-pressure oil pipes is stable and reliable, and the long-term seal effect is ensured.

Drawings

FIG. 1 is a schematic cross-sectional perspective view of the present invention (without the tapered shim);

FIG. 2 is a schematic cross-sectional perspective view of the present invention (with tapered shims);

FIG. 3 is a schematic cross-sectional view of a male of the present invention;

the names corresponding to the sequence numbers in the figure are as follows:

the structure comprises a male head 10, a stud structure 11, a tapered platform closing-in transition part 12, a ball head tail end 13, a plane stop end 131, an annular ball arc 132, a stop groove 14, an alignment cylindrical ring surface 15, a female head 20, a guide central hole 21, a concave central conical surface 22, a sealing ring 50, a rear end inner annular groove 23, a transition conical surface 24, a tangent annular sealing surface 30, a tapered gasket 40 and a sealing ring 50.

Detailed Description

The ball head sealing structure of the high-pressure oil pipe of the diesel engine is shown in figures 1-3, and comprises:

the male head 10 is provided with a stud structure 11 with a front protrusion, the front end of the stud structure 11 comprises a cone-shaped closing-in transition part 12 and a ball-end 13, the cone-shaped closing-in transition part 12 protrudes forward from the center of the front end of the stud structure 11, the ball-end 13 protrudes forward from the end face of the cone-shaped closing-in transition part 12, the starting part of the ball-end 13 and the end face of the cone-shaped closing-in transition part 12 are seamlessly connected, the front end of the ball-end 13 is a plane end-stop end 131, and the ball-end 13 is specifically a section of annular spherical arc 132 protruding forward in the thickness direction;

the female head 20 comprises a guiding central hole 21 and an inwards concave central conical surface 22, the inwards concave central conical surface 22 is arranged in the axial front of the guiding central hole 21 and is arranged with the same central axis, the inwards concave central conical surface 22 is a conical surface which closes up from back to front, and the guiding central hole 21 is an internal threaded hole;

the stud structure 11 is in threaded connection with the guiding center hole 21, and the annular spherical arc 132 of the ball head end 13 and the concave center conical surface 22 form a tangential annular sealing surface 30 which is arranged in a tight fit manner.

The conical gasket 40 is arranged in a mode that the conical gasket 40 is arranged in a copying mode on the concave central conical surface 22, the outer wall of the conical gasket 40 is arranged in a mode that the conical gasket is tightly attached to the concave central conical surface 22, the annular spherical arc 132 of the tail end 13 of the ball head is tightly attached to the corresponding position of the inner wall of the conical gasket 40 to form a sealing surface, when the sealing surface leaks, only the conical gasket 40 needs to be replaced, the conical gasket 40 is made of soft materials, and the conical gasket 40 can be suitable for being in tight contact with a peak and a valley of the damaged sealing surface to prevent media from leaking.

In specific implementation, a stopping groove 14 is formed in the rear end of the stud structure 11, a sealing ring 50 is sleeved on the stopping groove 14, a rear-end inner annular groove 23 is formed in the position, facing the stopping groove 14 of the stud structure 11, of the guide center hole 21, and the outer wall of the sealing ring 50 is arranged in a manner of being tightly attached to the rear-end inner annular groove 23 to ensure sealing of the connection tail end;

the front end of the stud structure 11 is provided with an alignment cylindrical ring surface 15, and the front end of the guide central hole 21 is provided with a transition conical surface 24, so that the axial positioning of the stud and the guide central hole is accurate and reliable;

the taper F of the conical table closing-in transition part 12 is 58 degrees, the taper of the concave central conical surface 22 is 60 degrees, the initial part of the ball head tail end 13 is in tangent connection with the tail end of the conical table closing-in transition part 12, the annular ball arc 132 of the ball head tail end 13 is ensured to be tightly attached to the concave central conical surface 22 to form a tangent annular surface, and further a tangent annular sealing surface is formed;

the roughness of the annular spherical arc 132 and the concave central cone 22 of the ball end 13 is Ra0.4.

During processing, in order to ensure good sealing performance, the jump of the tail end ball head 13 of the male head 10 and the central axis is required to be less than 0.1, and the roundness of the tail end ball head 13 is required to be less than 0.005. In specific implementation, the male head 10 and the female head 20 are both made of 40CrNiMoA alloy steel materials which have high strength and toughness and good full-hardening and anti-overheating stability.

The processing technology of the 40CrNiMoA alloy steel material comprises the following steps:

1. and (3) heat treatment: quenching and tempering, wherein the quenching of the steel is a heat treatment process of heating the steel to a temperature above a critical temperature Ac3 (hypoeutectoid steel) or Ac1 (hypereutectoid steel), preserving heat for a period of time to ensure that the steel is completely or partially austenitized, and then rapidly cooling the steel to a temperature below Ms (or isothermal temperature near Ms) at a cooling speed higher than a critical cooling speed to perform martensite (or bainite) transformation. The rigidity, hardness, wear resistance, fatigue strength and toughness of the steel are improved to meet special physical and chemical performance requirements of special steel such as ferromagnetism, corrosion resistance and the like, and the tempering has the function of effectively reducing or eliminating internal stress in a quenched steel part or changing the hardness and strength of the steel so as to improve the ductility or toughness to a certain degree;

2. firstly, roughly turning the shape, and then finely turning the shape in place to ensure the form and position tolerance;

3. the roughness of the grinding ball head and the tangent line directly influences the sealing performance once the roughness is not required.

During installation, when the ball head is connected with the conical surface, the axial alignment of the ball head and the conical surface needs to be fully ensured, so that the stress distribution of the contact surface is reasonable; the tightening force is also required to a certain extent, and cannot be too large or too small, and a relatively large tightening force can obtain a relatively wide sealing surface and a relatively large average contact stress, so that the sealing effect is enhanced; however, when the tightening force is too large, the seal surface yields to a large extent due to stress relaxation, and leakage is likely to occur after long-term use.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.

Claims

1. Diesel engine high pressure fuel pipe bulb seal structure, its characterized in that, it includes:

2. The diesel engine high pressure oil pipe ball head sealing structure of claim 1, characterized in that: the ball head is characterized by further comprising a conical gasket, wherein the conical gasket is arranged in a shape of profiling on the concave central conical surface, the outer wall of the conical gasket is arranged in a manner of clinging to the concave central conical surface, and an annular ball arc at the tail end of the ball head is clung to the corresponding position of the inner wall of the conical gasket to form a sealing surface.

3. The diesel engine high pressure oil pipe ball head sealing structure of claim 1 or 2, characterized in that: the rear end of the stud structure is provided with a stopping groove, a sealing ring is sleeved on the stopping groove, a rear end inner ring groove is arranged at the position, facing the stopping groove of the stud structure, of the guide center hole, and the outer wall of the sealing ring is tightly attached to the rear end inner ring groove.

4. The diesel engine high pressure oil pipe ball head sealing structure of claim 1 or 2, characterized in that: the front end of the stud structure is provided with an alignment cylindrical ring surface, and the front end of the guide center hole is provided with a transition conical surface.

5. The diesel engine high pressure oil pipe ball head sealing structure of claim 1 or 2, characterized in that: the taper of the closing-in transition part of the conical table is 58 degrees, the taper of the concave central conical surface is 60 degrees, and the initial part of the tail end of the ball head is in tangential connection with the tail end of the closing-in transition part of the conical table.

6. The diesel engine high pressure oil pipe ball head sealing structure of claim 1, characterized in that: the roughness of the annular spherical arc at the tail end of the ball head and the roughness of the concave central conical surface reach Ra0.4.