Structural Design Of External Cylindrical Honing Equipment For Artillery Recoil Piston Rod

The recoil piston rod is the core part of the artillery recoil device.The machining quality of the outer circle surface of the recoil bar directly affects the stability of the moving seal pair of the recoil machine,and then affects the artillery launch.The traditional manual measurement and manual grinding methods cannot ensure the dimensional accuracy and surface roughness of the outer circle of the recoil piston rod,which is easy to cause the friction and wear of the moving sealing pair of the recoil machine and produce liquid leakage,which is difficult to meet the needs of high service life of the artillery.In this paper,for the high-quality machining of the cylindrical surface of the gun retractor,the external cylindrical honing method is proposed,which breaks through the diameter in-situ measurement and controllable honing pressure feed technology,develops the NC external cylindrical honing equipment,and carries out the external cylindrical honing process test for the test piece of the retractor.The specific research contents are as follows:(1)The overall design scheme of external cylindrical honing equipment with diameter in-situ measurement function is put forward.It is clear that the external cylindrical honing equipment should have the functions of spindle rotation,external cylindrical honing processing and diameter in-situ measurement.The structural form,main design parameters and the working process of external cylindrical honing with recoil piston rod are determined.(2)It breaks through the key technology of diameter in-situ measurement and controllable honing pressure feed.The principle and method of diameter in-situ measurement based on comparative measurement are proposed.It is clear that the measurement error mainly comes from the rotation accuracy error of the workpiece,the straightness and parallelism error of the guide rail,and the error analysis model is established.Taking the ?60mm recoil piston rod as an example,it is analyzed that the measurement error caused by the above three errors in the sensitive direction of measurement error accounts for 5.64% of the accuracy requirements.The principle and scheme of constant pressure feed for external cylindrical honing driven by air pressure based on electric proportional valve are proposed,and the control method of constant pressure feed pressure for external cylindrical honing is determined.(3)An air pressure driven constant pressure feed external cylindrical honing equipment with diameter in-situ measurement function is developed.The structure design of in-situ measuring unit,cylindrical honing unit,spindle unit and tailstock unit of cylindrical honing equipment is carried out.The static and modal analysis of key structural components are completed.The analysis results show that the maximum offset of the vertical plate of the honing head in the X direction is 12.994μm,The maximum stress is 30.185 MPa.The maximum deformation and maximum stress of the bed under static load are 6.706μm and 29.069 MPa,which meet the design requirements of equipment reliability.The minimum frequency of the first six modes of the equipment bed is higher than that of the spindle motor and Z1 motor,which can avoid resonance.(4)By comparing with the measurement results of CMM,it is verified that the accuracy of in-situ measurement system can reach ± 2μm.The force measurement test of the external cylindrical honing unit is carried out by using the strain tension pressure sensor.The fluctuation of the honing feed pressure is less than 4N.It is verified that the external cylindrical honing unit can realize the stable control of the honing pressure.The process test is carried out for ?60 recoil piston rod.The effects of oil particle size,honing pressure,honing speed and honing times on the surface roughness and material removal rate of the test piece are studied,and the reasonable honing process parameters are determined.The surface roughness of the test piece of retractor bar processed with the selected reasonable process parameters can reach Ra 0.024μm.The roundness reaches 0.011 mm,and the diameter difference of adjacent 50 mm sections is less than 10μmThe developed external cylindrical honing equipment has been applied in the project to realize the diameter in-situ measurement and external cylindrical honing of the cylindrical surface of the artillery recoil piston rod,which is of great significance to the development of precision machining technology of military products in our country.