INNOVATIVE THREAD METHOD THROUGH CYLINDRICAL HOLES

Innovative activity in the field of engineering and technology, based on the use of best practices, contributes to scientific and technological progress in production. The latest projects in the field of technology significantly increase the technical and economic performance of enterprises. Innovative technical solutions of production nature significantly improve the structure and quality of production. Given the level of the proposed technological changes in the manufacture of threads in through holes, these innovations cover the field of combinatorial and partial. Today mechanical engineering is characterized by mechanization and automation of technological processes, a wide range of products of various parts. Among the non-detachable and detachable joints of parts, the threaded connection is the most common. Simplicity, reliability, the ability to adjust the force with which the conjugate surfaces come into contact, the possibility of repeated cycles of disassembly and assembly, etc., make this type of connection the most commonly used in mechanisms and machines of modern engineering. With the simplicity of the contact pair of threaded joints, where one of them contains the outer and the other the inner screw surface, during their manufacture there are problems that significantly inhibit production. The subject of research of this article is the solution of difficulties of manufacturing of an internal cut in through openings of small diameter by means of a tap. According to various sources, up to 80% of marriage is due to breaking taps. Studies by a group of scientists has found that more than 75% of taps break when the reverse (reverse) stroke of the tap, when the torque reaches its maximum value. The reverse scheme of production of a screw profile of a cutting surface by means of the mechanized devices and their alternative analogs, and also machines of drilling group, is offered.

Assessment of the Durability of Threaded Joints

The article deals with the determination of the resistance to cyclic loading of the threaded joints of pressure vessels and defective elements according to the failure mechanics criteria. Theoretical and experimental studies do not provide a sufficient basis for the existing calculation methods for the cyclic strength of the threaded joints of pressure vessels. The short crack kinetics in the threaded joints, a shakedown in one of the joint elements of pressure vessels, i.e., in the bolt or stud, has not been studied sufficiently. The calculation methods designed and improved within the study were based on theoretical and experimental investigations and were simplified for convenient application to engineering practice. The findings could be used to investigate the shakedown of studs of a different cross-section with an initiating and propagating crack. Value: the developed model for the assessment of durability of the threaded joints covers the patterns of resistance to cyclic failure (limit states: crack initiation, propagation, final failure) and shakedown (limit states: progressive shape change and plastic failure). Analysis-based solutions of plastic failure conditions and progressive shape change were accurate (the result was reached using a two-sided approach; the solutions were obtained in view of the parameters of the cyclic failure process in the stud (bolt) and based on experimental investigations of the threaded joints).

Control System of Assembly Production Organizational and Technological System of Automotive Cluster Factories

New term “Assembly Production Organizational and Technological System” is proposed. The model of Assembly Production Organizational and Technological System developed by the authors is described. In the model, this system is considered as a set of subsystems included in it: Assembly Tools Subsystem, Calibration Equipment Subsystem, Spare Tools and Parts Subsystem. Control system of the Assembly Production Organizational and Technological System is described. Developed by the authors model of Assembly Tools Set Element, which is a part of the Assembly Tools Subsystem is described. Developed by the authors classification of elements of assembly tools set is provided. The authors divide the assembly tools set into the following groups of equipment: torque wrenches, non-programmable screwdrivers and nutrunners, multispeed programmable screwdrivers and nutrunners, tooling and adaptors. Assembly tools for tightening threaded joints are divided into 3 groups according to the level of automation of the tightening process. These groups are divided into subgroups according to the principles developed by the authors. Developed classification of elements of assembly tools set is expedient to be used in automotive cluster assembly factories and other factories which have a similar assembly tools set structure.

Monitoring and Diagnosis System of Downhole Tubing Leakage

The downhole tubing in a gas well is affected by many factors such as high pressure erosion, gas lift operation, sand production at the bottom of the well and engineering construction, etc., which can easily lead to leakage of the threaded joints of the tubing and the pipe body, and the leaked natural gas will invade Annulus, making the annulus under pressure. The annular pressure caused by oil pipe leakage is a major safety hazard in oil and gas production. Therefore, the accurate diagnosis the degree of leakage of downhole tubing is of great significance to preventing the occurrence of production accidents effectively. To this end, a set of downhole tubing leak monitoring and diagnosis system has been developed by integrating fluid monitoring, acoustic wave detection and tracer detection technology, and the developed tubing leak monitoring and diagnosis system was used for leak detection tests on offshore platforms. The test results show that the developed tubing leakage monitoring and diagnosis system can meet the need of offshore gas well diagnosis, and realize the holographic diagnosis of the leakage degree of the downhole tubing without moving the downhole tubing string.

Bearing capacity of a threaded pair made of spatially reinforced carbon-carbon composite materials at high temperatures

The bearing capacity of a threaded pair made of spatially reinforced carbon-carbon composite materials (CCCM) with a 4DL reinforcement scheme in the temperature range from 20 to 2500 °C is experimentally determined. Recommendations are given for the design of CCCM threaded joints for operation at high temperatures. Keywords: carbon-carbon composite material, threaded joint, limit load, bearing capacity, threaded pair, high temperature. [email protected]

Friction Coefficient Estimate for Threaded Joints Made of Carbon-Carbon Composite Materials

Experimental studies were carried out to estimate the friction coefficients for a screw-nut threaded pair made of spatially reinforced carbon-carbon composite materials (CCCM). Quantitative values were obtained for the thread friction coefficient and nut end friction coefficient. The ultimate screw-in torque for the CCCM threaded pair was determined, and its failure mode at a destructive screw-in torque was established. The laboratory tests were carried out to measure the tightening force. The nut screw-in torque was measured using a torque wrench.