Generally speaking, all hydraulic pipelines of fully mechanized coal mining and high-end general mining support equipment are basically composed of high pressure rubber hose assembly and related pipeline accessories. The high pressure rubber hose has many specifications and models, and the amount of use is large. The failure performance of the high pressure rubber hose There are many forms and the reasons are complicated. In the working face and roadway, hundreds of meters long, exposed high-pressure pipelines, any failure may increase safety hazards; failure will directly cause the working face to stop, affect production efficiency, increase maintenance costs; in addition, replace in harsh environments high pressure rubber hose will inevitably pollute the system, increase the hidden troubles of other links in the system, and reduce the reliability and efficiency of the entire hydraulic system. This is a concern for any hydraulic system.
1. The problem form and impact of high pressure rubber hose assembly
2. Reason analysis of high pressure rubber hose
The reasons for the failure of the mine high pressure rubber hose assembly and intermediate joint components are summarized as follows:
(1) The pressure source of the hydraulic (emulsion) system adopts a three-piston pump or a five-piston pump, with high rated pressure, large flow, and large pressure pulsation. Each component of the pipeline is easy to fatigue and damage.
(2) The emulsion medium has low privacy, high density, and relatively poor corrosion resistance. Especially, the pH of the water in different mining areas is very different, and the management is not strict during use. The underground emulsion often fails to reach the specified oil-water ratio, and the rubber has been in In the immersion of this medium, it will inevitably deteriorate, harden and age.
(3) The damage of the inner rubber layer of the high-pressure hose accelerates the corrosion of the steel wire mesh of the hose and reduces the compressive strength of the high pressure rubber hose. The pressure wave has a strong impact on the high pressure rubber hose assembly and joint components, and leads to the fracture of dangerous sections of the high pressure rubber hose assembly and joint components.
(4) The coal mine production environment is dusty, humid, and the water is weakly alkaline. The vibrating pipeline rubs against environmental objects, so that the rubber on the surface of the high-pressure hose is worn, and the anti-corrosion layer on the surface of the joint component falls off, which promotes the damage process.
(5) The factories that produce high pressure rubber hose assemblies and intermediate joint components are mostly small and medium-sized enterprises. They are restricted by technology, equipment, capital and other conditions, and some do not even process according to the process requirements of the drawings. The high-pressure hose assembly and piping accessories cannot meet the requirements. To the technical requirements, the product quality is uneven, the strength is low, the life is short, and the pollution is serious, laying hidden dangers for sudden safety accidents.
(6) The design layout is unreasonable. Under normal circumstances, the high-pressure hose is mainly subjected to internal pressure and a certain external force. The incorrect arrangement will cause the high-pressure hose to be subjected to additional additional force for a long time and reduce the service life of the high pressure rubber hose assembly.
(7) The failed pipeline components are used for over-life. Since it is impossible to inspect and accurately determine whether high-pressure hoses and pipeline components have failed or reached their service life, there are a large number of components used over-life on site. These high pressure rubber hose are often prone to failure during use, leading to an increase in failure rate.