Projeto de um protótipo para medir força de união em montagens aparafusadas

Abstract

The deed of joining parts together can be understood like attach more than one element to give it a peculiar usefulness. For this it is necessary the assistance of a chemical or mechanical capable of generating a force which can hold the parts together. Such as usual methods, there are more than one way of ensuring that union, as welding, riveting or gluing. The focus of this work are the bolt connections. These junctions are widely applied when there is interest in future dismounting bolt assembly. when pressing a set a bolt against a set of pieces is the goal of ensuring union among the parties and create a force that prevents the release of the same. Some variables used in the process can be measured like torque and angle of rotation of the nut relative to the bolt. Others, such as friction force, force preload and roughness are economically unviable in display production levels. The objective of this work is to build a device that can measure the axial force acting on screw in a screw connection and thus obtain the torque coefficient (k) for various combinations of screws, nuts and washers. The study is restricted to the variables of the process, assembly systems, and data collection interface, where some concepts, data and formulas were reviewed in order to assist in the development and assembly of the equipment. For prototyping resources were optimized computational modeling of the mechanical structure and electronics, as well as in simulations and pre-testing. Assays were performed with different types of screws in order to observe the variation in the force acting on such elements and how this force can be influenced by characteristics of the bolt. As test results were obtained values close to those proposed in the literature for most of the screws tested, thus validating the proposal for which the equipment was developed