JP3408708B2 - Evaluation method of sealing performance - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve, a pump,
The present invention relates to a method for evaluating sealing performance in a sealing portion such as a pipe. 2. Description of the Related Art In a sealing portion of a valve, a pump, a pipe, or the like, the sealing performance is affected by the surface pressure of a contact portion. Therefore, the contact surface pressure is measured as a means for evaluating the sealing performance in the sealing portion. are doing. This method of measuring the contact surface pressure utilizes the fact that a thin film is inserted between the abutting members and that the film changes color in accordance with the surface pressure received from each member. Is evaluated, and the sealing performance between the abutting members is evaluated based on the obtained contact surface pressure. However, in the above-described conventional structure, the inserted film itself acts as a disturbance factor in the measurement of the contact surface pressure, and the value of the measured contact surface pressure is determined by the existence of the film. Not the actual case will be different from the contact pressure. Further, when the target fluid was at a high temperature, the heat resistance of the film was limited, so that the sealing performance of the evaluation target could be measured only under limited conditions. Furthermore, when a plurality of load cases act on the contact surface between the members in combination, it has been impossible to obtain a contact surface pressure corresponding to each load case. SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and the measuring means itself can accurately measure the contact surface pressure without causing disturbance, and can evaluate the sealing performance under a wide range of conditions. It is an object of the present invention to provide a method for evaluating seal performance that can be performed. [0005] In order to solve the above-mentioned problems, a method of evaluating sealing performance according to the present invention comprises disposing a sealing material between opposing contact surfaces, and in a direction parallel to the contact surfaces. When evaluating the sealing performance between the contact surfaces of both members in a member subjected to fluid pressure, modeling each member with a finite element, assuming a thin contact element for calculating the surface pressure between the contact surfaces, A thin contact element is set at a plurality of locations between the contact surfaces between the outside and inside of the member, and the contact analysis by the finite element method applies the stress acting on the contact element in the direction normal to the contact surface. Calculate as the pressure, eliminate the innermost contact element at the location where the product of the gasket coefficient and the fluid pressure, which represent the sealing characteristics of the sealing material, is greater than the contact surface pressure, and remove the contact element located on the innermost side. The contact performance by the finite element method is repeatedly performed under the condition of applying a fluid pressure, and the sealing performance is evaluated using the number of contact elements remaining on the contact surface as an evaluation scale. Embodiments of the present invention will be described below with reference to the drawings. In the present embodiment, a sealing material is arranged between contact surfaces of opposed members, and in a member that receives fluid pressure in a direction parallel to the contact surface, the sealing performance is evaluated by a contact analysis using a finite element method. . FIGS. 1 and 2 are conceptual diagrams of the present invention, in which members 1 and 2 are modeled by finite elements, and real values of physical properties such as Young's modulus and Poisson's ratio are set. A contact element 3 that models a sealing material is inserted between the contact surfaces 1a and 2a of the members 1 and 2. Contact element 3
Is a thin wall having anisotropy, and is disposed at a plurality of positions along the contact surface between the outside and the inside of the members 1 and 2, and in the present embodiment, three contact elements 3a, 3b,
3c is set. The members 1 and 2 receive a fluid pressure p in a direction parallel to the contact surfaces 1a and 2a. In this finite element model, FIGS.
The analysis is performed according to the procedure shown in. First, in the finite element model, the gasket coefficient α representing the sealing characteristics defined by the shape and size of the sealing material, the material, and the like are input to the contact element 3, and the load conditions such as the fluid pressure p and the external force and the constraint conditions are input. . (Steps shown in FIG. 3) Next, under this boundary condition, the stress acting on the contact surfaces 1a, 2a in the normal direction is applied to the contact elements 3c, 3b, 3c by the contact analysis by the finite element method. Contact surface pressure P
Is calculated as (Steps shown in FIGS. 3 and 4) At this time, as shown in FIG. 2, at a portion where the product of the gasket coefficient α and the fluid pressure p is larger than the contact surface pressure P,
The contact element 3a located on the innermost side is extinguished, and the contact analysis is performed again under the condition that the fluid pressure p is applied to the area A corresponding to the extinguished contact element 3a. The above-mentioned contact analysis is repeated a predetermined number of times or until the properties of the contact surfaces 1a and 2a are reduced, and the sealing performance is evaluated using the number of contact elements remaining on the contact surfaces 1a and 2a as an evaluation scale. To evaluate. (Each step shown in FIGS. 4 and 5) As described above, according to the present invention, since the contact surface pressure is obtained by analysis, the measuring means does not become a disturbance factor. The contact surface pressure can be accurately measured, and the sealing performance can be evaluated under a wide range of conditions. In addition, since the sealing performance is evaluated using the number of contact elements remaining on the contact surface after the analysis as an evaluation scale, a quantitative evaluation can be performed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a conceptual diagram showing a modeled configuration in an embodiment of the present invention. FIG. 2 is a conceptual diagram showing a modeled configuration. FIG. 3 is a flowchart showing an analysis procedure by the finite element method in the embodiment. FIG. 4 is a flowchart showing an analysis procedure by the finite element method in the embodiment. FIG. 5 is a flowchart showing an analysis procedure according to the finite element method in the embodiment. [Description of Signs] 1, 2 members 1a, 2a contact surfaces 3a, 3b, 3c contact elements

────────────────────────────────────────────────── ─── Continued on the front page (58) Fields investigated (Int. Cl. ⁷ , DB name) G01M 3/00 G06F 17/50 612 G01M 13/00 JICST file (JOIS)

Claims (1)

(57) [Claim 1] A seal member is arranged between opposing contact surfaces, and in a member receiving fluid pressure in a direction parallel to the contact surface, a seal between the contact surfaces of both members is provided. In evaluating the performance, each member is modeled with a finite element, a thin contact element for calculating the surface pressure between the contact surfaces is assumed, and a plurality of thin contact elements are provided between the contact surfaces between the outside and the inside of the member. It is set at a point, and the stress acting in the direction normal to the contact surface is calculated as the contact surface pressure acting on the contact element by contact analysis using the finite element method, and the gasket coefficient and the fluid pressure, which represent the sealing characteristics of the seal material, are calculated. To eliminate the innermost contact element at the site where the product of
It is characterized by repeatedly performing contact analysis by the finite element method under the condition that fluid pressure is applied to the area corresponding to the disappeared contact element, and evaluating the sealing performance using the number of contact elements remaining on the contact surface as an evaluation scale Evaluation method of sealing performance.