A connection sealing assembly for high-pressure oil rail helium sealing test

Abstract

The present invention relates to a connection sealing assembly for helium sealing test of a high-pressure oil rail, comprising a pressure measuring end joint, a vent hole is provided in the middle of the pressure measuring end joint, a mounting hole communicating with the vent hole is provided in the middle of the outside of the pressure measuring end joint, an airtight plug is provided in the mounting hole to seal it, the airtight plug is a large end face structure, and its inner end face is a flat end face, and the inner end face of the airtight plug is sealed with the outer end face of the pressure measuring end joint. The present invention changes the structure of the airtight plug and sets it as a large end face structure, changes the original bottom of the mounting hole as a sealing surface to the inner end face of the airtight plug and the outer end face of the pressure measuring end joint as the sealing surface, and guides the force to the outer end of the pressure measuring end joint, thereby avoiding excessive pressure from damaging the bottom conical surface of the pressure measuring end joint made of a softer material in the mounting hole.

Description

Technical Field

[0001] The invention relates to the technical field of high-pressure fuel rails, and in particular to a connection sealing component for helium sealing testing of high-pressure fuel rails. Background Art

[0002] The function of the high-pressure fuel rail is to store fuel and suppress the pressure fluctuations caused by the high-pressure pump supplying fuel and the injector spraying fuel to ensure the stability of the system pressure. During the use of the high-pressure fuel rail, a pressure measuring end connector needs to be screwed into one end of the high-pressure fuel rail for installing the pressure measuring sensor, and the sealing performance of the high-pressure fuel rail must be ensured during use.

[0003] At present, in order to meet the National VI emission requirements, the working pressure of the engine fuel system of fuel vehicles has been increased from 250 bar to 350 bar. If the helium sealing test scheme of the fuel rail is based on the previous sealing scheme of the pure stainless steel fuel rail (such as Figure 1 ), which will damage the sealing surface of the pressure sensor installed in the pressure measuring end joint, causing oil leakage.

[0004] The original working pressure of 250bar oil rails are all made of stainless steel. Stainless steel is relatively hard and has good strength. It can seal the four nozzle holes and the oil inlet joint. The pressure measuring joint can be directly sealed on the conical sealing surface. The 350bar oil rail is made of forged blanks through machining. It is an oil rail with an integral structure. Only the pressure measuring end joint needs to be assembled. The material of the 350bar pressure measuring end joint is alloy copper, which is softer than stainless steel. The working pressure is increased from 250bar to 350bar. The pressure on the same sealing surface during the sealing test is 40% greater than before. If the copper joint sealing cone surface is still used as the helium test sealing surface, the 350bar pressure acts on the sealing cone surface of the copper joint, and the sealing cone surface will be damaged, which will cause the high-pressure sensor to be installed during use without sealing, causing leakage. Summary of the invention

[0005] The purpose of the present invention is to solve the above-mentioned problem and provide a connection sealing assembly for helium sealing test of high-pressure oil rails, which adopts an airtight plug with a large head end face, and the airtight plug is sealed on the outside of the pressure measuring end joint. The inner end face of the airtight plug and the outer end face of the pressure measuring end joint are used as sealing surfaces to prevent excessive pressure from damaging the bottom sealing cone surface of the pressure measuring end joint made of a relatively soft material in the installation hole.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] A connection sealing assembly for helium sealing test of a high-pressure oil rail is installed at the end of the high-pressure oil rail, comprising a pressure measuring end joint, the pressure measuring end joint is sealingly installed at one end of the high-pressure oil rail, a vent hole is provided in the middle of the pressure measuring end joint, a mounting hole communicating with the vent hole is provided in the middle of the pressure measuring end joint outside, an airtight plug is provided in the mounting hole to seal the mounting hole, the airtight plug is a large end face structure, the inner end face of the airtight plug is a flat end face, and the inner end face of the airtight plug is sealed with the outer end face of the pressure measuring end joint.

[0008] The present invention changes the structure of the airtight plug and sets it as a large-head end face structure. The original bottom of the installation hole is changed to use the inner end face of the airtight plug and the outer end face of the pressure measuring end joint as the sealing faces, and the force is directed to the outer end of the pressure measuring end joint. In this way, it is avoided that excessive pressure causes the bottom conical surface of the pressure measuring end joint made of a softer material in the installation hole to be damaged.

[0009] As a preferred technical solution, the airtight plug comprises a thick external plug body and a thin connecting section, and the airtight plug is installed in the mounting hole of the pressure measuring end connector through the connecting section.

[0010] As a preferred technical solution, the connecting section is screwed into the mounting hole via threads, and the length of the connecting section is shorter than the depth of the mounting hole in the pressure measuring end connector.

[0011] As a preferred technical solution, a sealing ring is provided between the airtight plug and the pressure measuring end joint. Since the large head plane of the inner end of the airtight plug has a large area, a large diameter sealing ring can be selected to withstand the same sealing pressure and is not easily deformed. In addition, the design has a large test range, and leakage between the large plane and the thread of the copper joint can also be tested.

[0012] As a preferred technical solution, the airtight plug is provided with a sealing ring installation groove at the connection between the inner end surface of the external plug body and the connecting section, and the sealing ring is installed in the sealing ring installation groove.

[0013] As a preferred technical solution, the size of the outer plug body of the airtight plug is comparable to the size of the pressure measuring end connector.

[0014] As a preferred technical solution, the pressure measuring end joint is a pressure measuring end joint made of alloy copper or copper material.

[0015] As a preferred technical solution, the pressure measuring end connector is screwed into the pressure measuring cavity via threads.

[0016] As a preferred technical solution, the bottom of the mounting hole of the pressure measuring end joint is a conical surface, which is used to install a pressure measuring sensor when in use.

[0017] The airtight plug of the present invention is a large-head end face structure, and its inner end face is a flat end face. The airtight plug is installed on the pressure measuring end joint through the mounting hole, and the inner end face of the airtight plug and the outer end face of the pressure measuring end joint are used as sealing surfaces, and a sealing ring for sealing is arranged between the two. The original bottom conical surface in the mounting hole is no longer sealed as the sealing surface, and then during high-pressure testing, the force is directed to the outer end of the pressure measuring end joint, thereby avoiding excessive pressure from damaging the bottom conical surface of the pressure measuring end joint made of a softer material in the mounting hole, and effectively protecting the conical surface to be used when assembling the pressure sensor.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] 1. Wider application range: This design can be used for sealing test of high-pressure oil rails with higher pressure and softer materials;

[0020] 2. Strong operability: Due to the large area of ​​the large head plane, the sealing ring can be selected with a large diameter, which can withstand the same sealing pressure and is not easily deformed;

[0021] 3. The design test range is large, and the leakage between the large surface and threads of the copper joint can also be tested. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of the structure of the existing oil rail seal test connection seal assembly;

[0023] Figure 2 A schematic diagram of the connection seal assembly of the present invention being installed on the oil rail;

[0024] Figure 3 It is a structural schematic diagram of the connection sealing assembly of the present invention;

[0025] Figure 4 It is a schematic structural diagram of the airtight plug of the present invention.

[0026] In the figure: 1-pressure measuring end joint; 101-vent hole; 102-mounting hole; 2-airtight plug; 3-oil rail; 4-sealing ring; 5-sealing cone surface; 2'-existing airtight plug. DETAILED DESCRIPTION

[0027] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] Example

[0029] Existing fuel rail helium seal test solutions are as follows: Figure 1As shown, it uses a conical airtight plug 2' installed in the pressure measuring end joint 1 on the oil rail 3. The test pressure is 250bar. The material is stainless steel. Stainless steel is relatively hard and has good strength. It seals the 4 nozzle holes and the oil inlet joint. The pressure measuring joint can directly use the sealing surface on the drawing. However, for the 350bar oil rail, it is made of forged blanks through machining. Only one part, the pressure measuring end joint, needs to be assembled. The material of the 350bar pressure measuring end joint is alloy copper, which is softer than stainless steel. The working pressure is increased from 250bar to 350bar. During the sealing test, the pressure on the same sealing surface is 40% greater than before. If the copper joint sealing cone surface is still used as the helium test sealing surface, the 350bar pressure acts on the copper joint sealing cone surface, and the sealing cone surface will be damaged, which will cause the high-pressure sensor to be installed during use without sealing, causing gasoline leakage.

[0030] To solve this problem, the present invention provides a connection sealing assembly for helium sealing test of a high-pressure oil rail.

[0031] like Figure 3 , which is installed in the pressure measuring cavity at the end of the high-pressure oil rail 3, such as Figure 2 The left middle end includes a pressure measuring end joint 1 and an airtight plug 2. The pressure measuring end joint 1 is installed in the pressure measuring cavity of the high-pressure oil rail 3 through a threaded sealing connection. A vent hole 101 is provided in the middle of the pressure measuring end joint 1. The pressure measuring end joint 1 is provided with a mounting hole 102 in the middle of its outer portion that communicates with the vent hole 101. When in use, the mounting hole 102 is used to install a pressure sensor. The bottom of the mounting hole 102 is a sealing cone 5 for cooperating with the pressure sensor.

[0032] When performing the airtight test, the airtight plug 2 is installed in the mounting hole 102. Figure 4 The airtight plug 2 includes a thick external plug body and a thin connecting section. The airtight plug 2 is screwed into the mounting hole 102 of the pressure measuring end joint 1 through the connecting section thread. The inner and outer end surfaces of the external plug body are both flat end surfaces. The length of the connecting section is shorter than the depth of the mounting hole 102 to ensure that the sealing cone surface 5 is a cavity.

[0033] In addition, the size of the outer plug body of the airtight plug 2 is comparable to that of the pressure measuring end joint 1, and the pressure measuring end joint 1 is a pressure measuring end joint 1 made of alloy copper or copper. In order to increase the sealing effect, a sealing ring 4 is provided between the airtight plug 2 and the pressure measuring end joint 1, and a sealing ring 4 installation groove is provided at the connection between the inner end face of the outer plug body of the airtight plug 2 and the connecting section, and the sealing ring 4 is installed in the sealing ring 4 installation groove. Since the large head plane of the airtight plug 2 itself has a large area, a large diameter sealing ring 4 can be selected for the sealing ring 4, which can withstand the same sealing pressure and is not easily deformed under force. In addition, the design has a large test range, and leakage between the large plane and the thread of the copper joint can also be tested. The airtight plug 2 of the present invention is a large-head end face structure, and its inner end face is a flat end face. The airtight plug 2 is installed in the pressure measuring end joint 1 through the mounting hole 102, and the inner end face of the airtight plug 2 and the outer end face of the pressure measuring end joint 1 are used as sealing surfaces, and a sealing ring 4 for sealing is arranged between the two. The original bottom conical surface in the mounting hole is no longer sealed as a sealing surface, and then during high-pressure testing, the force is directed to the outer end of the pressure measuring end joint, thereby avoiding excessive pressure from damaging the bottom conical surface of the pressure measuring end joint made of a softer material in the mounting hole, and effectively protecting the sealing cone surface 5 to be used when assembling the pressure sensor.

[0034] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A connection sealing assembly for helium sealing test of a high-pressure oil rail, installed at the end of the high-pressure oil rail, comprising a pressure measuring end joint, the pressure measuring end joint is sealingly installed at one end of the high-pressure oil rail, a vent hole is provided in the middle of the pressure measuring end joint, and a mounting hole communicating with the vent hole is provided in the middle of the outer portion of the pressure measuring end joint, characterized in that: An airtight plug is provided in the mounting hole to seal it, the airtight plug is a large end face structure, the inner end face of which is a flat end face, and the inner end face of the airtight plug is sealed with the outer end face of the pressure measuring end joint; For the 350bar fuel rail, the 350bar pressure measuring end connector material is alloy copper; The bottom of the mounting hole is a sealing cone surface; The airtight plug includes a thick external plug body and a thin connecting section. The airtight plug is screwed into the mounting hole of the pressure measuring end joint through the connecting section thread. Both inner and outer end surfaces of the external plug body are flat end surfaces. The length of the connecting section is shorter than the depth of the mounting hole to ensure that the sealing cone surface is a cavity. A sealing ring is provided between the airtight plug and the pressure measuring end joint; The airtight plug is provided with a sealing ring installation groove at the connection between the inner end surface of the external plug body and the connecting section, and the sealing ring is installed in the sealing ring installation groove.

2. A connection sealing assembly for high-pressure fuel rail helium sealing test according to claim 1, characterized in that: The size of the outer plug body of the airtight plug is comparable to the size of the pressure measuring end connector.

3. A connection sealing assembly for high-pressure fuel rail helium sealing test according to claim 1, characterized in that: The pressure measuring end joint is screwed into the pressure measuring cavity at the end of the high-pressure oil rail through threads.

4. A connection sealing assembly for high-pressure fuel rail helium sealing test according to claim 1, characterized in that: The bottom of the mounting hole of the pressure measuring end joint is a conical surface, which is used to install a pressure measuring sensor when in use.

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