Open AccessInfluence of dynamic loads in joints on dimensional stability
Author(s) -
A. S. Yamnikov,
А. А. Маликов,
O. S. Kashmin,
I. D. Troitsky
Publication year - 2021
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/1100/1/012019
Subject(s) - stiffness , machining , deformation (meteorology) , surface finish , grinding , mechanical engineering , computer science , structural engineering , surface roughness , cartridge , flank , materials science , engineering , composite material , sociology , anthropology
In small arms manufacturing the lock dimensional chain final link precision is secured with manual file fitting and removing the tolerance intentionally left on the recoil lugs. The manual process reduces the contact stiffness of the lock components, and the final link dimension (between the cylindrical gauge end that simulates a cartridge, and the breeching lock face) set during the assembly is distorted when the breech lock components are exposed to shot impact loads. For this reason, the cylindrical cartridge dummy used for the initial assembly is sized to allow for subsequent plastic deformation at the breech lock component interfaces. The deformation value is determined experimentally on an ad hoc basis. Polynomial expressions have been obtained experimentally for the interface plastic deformation vs. relative positioning errors and surface finish relation for parts made of typical military steel grades. To study the relation between the interface surface machining methods and contact stiffness flat specimens, 50RA steel quenched to HRC 40…45 (the roughness R z is 10…15 μm) were machined as follows: peripheral pregrinding; flank milling; file crosswise (at 45°) movements. The results generated after processing the measurements made with a HOMMEL TESTER W55 instrument show that finish flank milling yields the best results.