MACHINE TAPS FOR CUTTING SCREWS

Abstract

The common use of screw joints connections in engineering is caused by their simple construction, high load-bearing capacity, reliability and convenience of connection and disconnection of parts. The high use of screw joints is also explained by the fact that there are a lot of special screw parts adapted to a variety of structures, there is their broad standardization and low cost in terms of mass production. It is known that 60….70% of general machinery parts have screw joins. And the processing of these joints with cutting tools is a complex technological problem, especially in manufacturing the accurate screw holes. Research considers the efficiency performance of taps by means of reducing their breakdowns on the basis of the design of taps, taking into account the changes in their parameters in the process of screw cutting and the state of the individual parts of this tool. The progressive design machine taps for cutting screws are examined in the study. In this construction the deformation angle of the screw increases in terms of continuous teeth cutting teeth to 0.2 degrees and then stabilizes at the simultaneous operation of all the teeth on the winding of 0.175 degrees and gradually decreases when the fluctuations drop to zero when the cut screw teeth leave. On the basis of theoretical research it is recommended to improve the design of the device for cutting screws by curved taps. The advantage of the tap is the improvement of the work conditions: separation of chippings that helps to form a cleaner surface and it is very important when dealing with viscous materials. They also provide a greater density of taps regrinding to avoid joins of the holes and their break-down.