CN-122021040-A - Sealing performance analysis method and design method for high-pressure common rail pump sealing structure

CN122021040ACN 122021040 ACN122021040 ACN 122021040ACN-122021040-A

Abstract

The application relates to the technical field of diesel engine fuel supply, and discloses a method for analyzing the sealing performance of a sealing structure of a high-pressure common rail pump and a design method. And then, carrying out a response surface test by adopting a Box-Behnken design, establishing a stress field finite element model, and calculating the maximum equivalent stress and the minimum contact pressure of the sealing surface under different parameter combinations by a system. And constructing a quantitative mathematical model between the two key indexes and the design parameters through response surface analysis. Finally, the optimization target is used for maximizing the minimum contact pressure and minimizing the maximum equivalent stress, so that the cooperative optimization of key parameters of the sealing structure is realized, and the accurate analysis of the sealing performance of the high-pressure sealing structure is further realized.

Inventors

LIU ZHENMING
ZHENG XIANQUAN
WEI HAONAN
HUO BAIQI
LIU JINGBIN
LIU QI
LUO LI
NIE TAO
CHEN PING
ZHOU LEI

Assignees

中国人民解放军海军工程大学
中国人民解放军92942部队

Dates

Publication Date: 20260512
Application Date: 20260205

Claims (10)

1. The method for analyzing the sealing performance of the sealing structure of the high-pressure common rail pump is characterized by comprising the following steps of: analyzing the load condition and failure mode of the sealing structure of the high-pressure common rail pump; Screening key design parameters of the sealing structure according to the analysis results of the load and failure modes; Designing a response surface test, and performing test design aiming at the key design parameters; Establishing a stress field finite element model of the sealing structure, and calculating stress distribution under different design parameter combinations; Recording the maximum equivalent stress and the minimum contact pressure of the sealing surface under different design parameter combinations; and analyzing the influence of design parameters on the sealing performance based on the maximum equivalent stress and the minimum contact pressure, and performing parameter optimization.
2. The method of claim 1, wherein the key design parameters include: sealing surface edge fillet radius, contact surface edge cone angle alpha, sealing surface boss thickness h, sealing ring belt diameter D and bolt pretightening force F.
3. The method of claim 2, wherein the response surface test is a four-factor, three-level Box-Behnken design, the four factors including preload force F, taper angle α, boss thickness h, and annulus diameter D.
4. A method according to claim 3, wherein the values of the pre-tightening force F comprise 30kN, 50kN and 70kN; the cone angle alpha has the values of 90 degrees, 120 degrees and 150 degrees; the value of the boss thickness h comprises 0.2mm, 0.3mm and 0.4mm; the values of the diameter D of the girdle comprise 19.2mm, 20.0mm and 20.8mm.
5. The method according to claim 1, wherein the minimum contact pressure is used as an evaluation index of sealing performance and the maximum equivalent stress is used as an evaluation index of structural reliability.
6. The method according to claim 1, wherein the method further comprises: And obtaining a functional relation between the maximum equivalent stress and the minimum contact pressure of the sealing surface and the design parameters through response surface analysis, and carrying out parameter optimization based on the functional relation.
7. The method of claim 6, wherein the optimization corresponds to a goal of minimum contact pressure maximization and maximum equivalent stress minimization.
8. The method of claim 6, wherein the response surface equation for the maximum equivalent stress is: , Wherein, the For the maximum equivalent stress of the sealing surface, In order to be a pre-tightening force, For the contact surface edge taper angle, Is the thickness of the boss at the edge of the sealing surface, To seal the annulus diameter.
9. The method of claim 6, wherein the response surface equation for the minimum contact pressure is: , Wherein, the For the minimum contact pressure of the sealing surface, In order to be a pre-tightening force, For the contact surface edge taper angle, Is the thickness of the boss at the edge of the sealing surface, To seal the annulus diameter.
10. A method for designing a sealing structure of a high-pressure common rail pump, characterized in that an optimal design parameter combination is determined by adopting the method for analyzing the sealing performance of the sealing structure of the high-pressure common rail pump according to any one of claims 1 to 9, so as to improve the sealing performance and the structural reliability.

Description

Sealing performance analysis method and design method for high-pressure common rail pump sealing structure Technical Field The application relates to the technical field of diesel engine fuel supply, in particular to a method for analyzing the sealing performance of a sealing structure of a high-pressure common rail pump and a design method. Background The high-pressure common rail pump of the diesel engine is taken as one of core components of the fuel supply system, and plays a vital role in the working process of the common rail system and the whole diesel engine. The working pressure of the high-pressure pump is one of the key performance parameters, and can obviously influence the atomization quality and combustion efficiency of the fuel oil as well as the power performance, emission performance and reliability of the diesel engine. In the prior art in China, the maximum working pressure of the high-pressure pump is usually not more than 180 MPa, if the maximum working pressure is raised to be more than 200 MPa, the high-pressure pump is easy to cause fatigue failure due to an oil supply element of the high-pressure pump after running for a certain time, faults such as high-pressure sealing failure, fatigue fracture of a plunger component and the like are caused, the oil supply flow and efficiency are obviously reduced when the high-pressure pump is light, and the high-pressure pump completely loses working capacity when the high-pressure pump is heavy. Aiming at the problem that the sealing structure of the high-pressure pump is easy to generate sealing failure under higher pressure, the current main solution of domestic manufacturers is to change the tightening torque of the sealing structure of the high-pressure pump, namely, adjust the assembly pretightening force of the sealing structure to realize the sealing performance under higher pressure. However, simply increasing the assembly preload, while meeting the sealing requirements at higher pressures, the seal structure has a higher stress level and is more susceptible to fatigue failure, resulting in a reduced service life of the high pressure pump seal structure. Moreover, the influence rule of the tightening torque/pretightening force on the sealing performance of the high-pressure pump sealing structure is not clear, and in actual engineering, the test can be carried out only after the tightening torque is changed, so that the leakage amount of the sealing structure of the high-pressure pump and the running time for obvious leakage are observed and measured. Therefore, the sealing performance of the high-pressure pump sealing structure is closely related to design parameters of the sealing structure besides being highly related to the assembling pretightening force, but the prior art lacks a perfect method for analyzing the sealing performance of the high-pressure sealing structure, so that the research on the influence rule of the sealing structure on the sealing performance is extremely deficient, and the sealing performance of the high-pressure sealing structure cannot be accurately analyzed. It should be noted that the information disclosed in the foregoing background section is only for enhancement of understanding of the background of the application. Disclosure of Invention The following presents a simplified summary in order to provide a basic understanding of some aspects of the disclosed embodiments. This summary is not an extensive overview, and is intended to neither identify key/critical elements nor delineate the scope of such embodiments, but is intended as a prelude to the more detailed description that follows. The method for analyzing and designing the sealing performance of the high-pressure common rail pump sealing structure can solve the problem that the sealing performance of the high-pressure sealing structure cannot be accurately analyzed. The embodiment of the disclosure provides a method for analyzing sealing performance of a sealing structure of a high-pressure common rail pump, which can comprise the following steps: analyzing the load condition and failure mode of the sealing structure of the high-pressure common rail pump; Screening key design parameters of the sealing structure according to the analysis results of the load and failure modes; Designing a response surface test, and performing test design aiming at the key design parameters; Establishing a stress field finite element model of the sealing structure, and calculating stress distribution under different design parameter combinations; Recording the maximum equivalent stress and the minimum contact pressure of the sealing surface under different design parameter combinations; and analyzing the influence of design parameters on the sealing performance based on the maximum equivalent stress and the minimum contact pressure, and performing parameter optimization. The embodiment of the disclosure provides a design method of a sealing structure of a high-press