Research On The Key Technology Of Chamfering Operation For Submarine Pipeline Maintaining Tool

Submarine pipelines play an important rule in the submarine oil and gas transmission system.Due to the complex submarine environment,submarine pipelines will be damaged.Submarine pipeline maintaining tool has many functions.It can effectively deal with the emergency of submarine pipeline and reduces economic loss and environmental pollution.China's underwater maintenance technology started late and there is a big gap with foreign countries.Based on the maintenance machine,the key technology of chamfering is studied in this paper.Finally,the design of the paper is verified by experiments.With the increase of transportation pressure,the strength of submarine pipeline is higher and higher.In order to reduce the energy consumption of chamfering high strength pipeline,reducing cutting force and power regard as a target.This paper designs a chamfering tool to chamfer the pipelines of high strenghth.X100 Pipeline Steel as research object,this paper uses Johnson-Cook's constitutive equation to simulate the pipe material.This paper uses controling single variable to define the cutting tool of geometric angle.Using this method creates the cutting tool of 3D model and applying large feed rate and cutting speed be simulated in 3D cutting works to obtain the results of large cutting power and cutting torque.Controling cutter edge's trajectory line ensures the quality of chamfering surface indirectly.This research method in order to wipe off the pipeline's burr and follow-up machine be worked expediently.Based by working principle and processing mode,this paper has deduced the expression of cutting speed and feed rate and established two equations of motion by two installation modes such as setoff installation and non setoff installation.According to the different set up such as rotational speed ratio?offset and different turn,this research has obtained six processing methods.Track vector equation be programed in the CREO and then controling variable method be used to obtain the best Chamfering method by analysing the simulation results.In order to analysing the question of under-cut or over-cut,this paper has designed a method to solve eccentricity error.And then using this result has designed a revising trajectory error to ensure this error in certain scope.In order to acquire the steady speed of cutting tool on the direction of pipelines and avoid impact,this paper applys trigonometric function addition and subtraction method to control the speed of feed motor based by PID control system.And then this desigen has been simulated in the AMESim.Finally,this simulation proves the right of this design.In order to avoid the influence of cutting tool's speed,this paper designs that proportional governor valve be installed in front of the tool principal axis and cutter head rotation's hydraulic motor.By this way,this paper has researched the principle of rate of flow.Finally,this design be simulated in the AMESim.The simulation result demonstrates that it can output stable flow to the hydraulic motor quickly under the fluctuation of external load and meet the requirements of different speed.In this paper,the chamfering experiment of subsea pipeline maintenance equipment is carried out.The experimental results show that the modified trajectory error method designed for the uneven chamfer quality can significantly improve the chamfer quality of pipelines.The tool feed displacement along the pipe diameter direction changes smoothly.The cutting speed of hydraulic motor is stable,meeting the machining requirements of machines and tools.Through the combination of theoretical research and experimental research,this paper completed the key technology research of chamfering process in the operation module of subsea pipeline maintenance tools.Finally,this paper lays the foundation for the sea trial of the engineering prototype of the subsea pipeline maintenance equipment.