Sealing mechanism of large size and large deformation rubber cylinder for pipeline intelligent plugging robot under multiple factors

Abstract

Large-volume rubber cylinder is a core component of pipeline intelligent plugging robot (PIPR). It is used for plug pipe section during pipeline rerouting, maintenance, and repair operations to prevent large-area leakage of pipeline oil and gas. This paper studies the sealing mechanism of large size and large deformation rubber cylinder of the PIPR under the influence of different rubber materials, axial length, radial length and inclined angle. Based on large deformation characteristics of rubber material, the theoretical mechanics of rubber cylinder were deduced and analyzed. Constitutive test of rubber material was carried out, and constitutive relationship parameters of rubber material were obtained. The finite element simulation model of rubber cylinder sealing mechanism analysis is established, and the influence of various system parameters and working conditions on the model is considered. In addition, visible indoor tests were established to verify the simulation model. It showed that stress concentrated on the apex and shoulder inside the rubber cylinder directly affected the deformation damage of rubber cylinder. After comparing the analysis result of the sealing effect of rubber cylinder under various parameters, it is concluded that the optimal rubber cylinder structure is 180 mm in axial length, 55 mm in radial thickness, 28° inclination angle, and hardness of rubber material is 85HA. This study provides a reference for the optimization design of rubber cylinder of PIPR. It has important engineering significance for the successful implementation of the plugging operation.