Introduction. Up to 23% of all cylinder blocks of used engines D-245 and D-260 have worn out sockets for the liner sleeve collar in-depth and shall be discarded. The aim of the study was to increase the durability of the cylinder blocks of the mentioned above engines by processing the sockets in the repair size with the subsequent installation of adjusting washers. Materials and Methods. In the article, the method of dimensional analysis was used to solve the problems. Based on the data presented in the technical documentation, the dimension chains were calculated when the piston moves to the lower and upper dead center. Results. The conducted studies of dimension chains found that when the piston moves to the lower and upper dead center with gaps in the joints corresponding to the new units, the distance between the bottom of the piston and the head of the unit can be from 0.488 to 1.592 mm, and with gaps corresponding to the permissible during operation – from ‒0.035 to 1.15 mm. According to the results of calculations, the depth of the socket under the liner collar in the boring process should be within 9,4+0,08+0,04 mm, i.e. in the range of 9.44...9.48 mm. Discussion and Conclusion. As a result of the study, the dimensional analysis found that the permissible value for milling the block stopping plane is 0.35 mm, and the depth of the liner collar when installing the adjusting washer with a thickness of 0.4 mm shall be from 9.45 to 9.47 mm.
Introduction. The article deals with the development of a device for evaluating technical condition on of volumetric hydraulic drives made in Russia and abroad at repair and service centres. Materials and Methods. The study uses the statements of theoretical mechanics and hydrodynamics, the basic principles of mechanisms and machines production. For technical condition evaluating of volumetric hydraulic drives, the method of hydraulic loading of hydraulic motor was applied. Reliability of results was confirmed during experimental settings of the hydraulic loading device stand. Results. A stand design with the hydraulic loading device was developed and put into practice for new technical condition evaluating of volumetric hydraulic drives, made in Russia and abroad, at repair and service centres. A property of the stand is the use of the hydraulic loading method when the torque (braking) moment on the shaft of the tested hydraulic rotor is created using a hydraulic machine. The stand consists of data processing and measurement units. The data processing unit is based on a multifunctional data acquisition board connected with a personal computer. The structure of the data measurement unit includes a frequency converter connected to an electric motor, a drive shaft for connecting the shaft of the tested hydraulic pump; hydraulic system having a hydraulic tank; suction, control, drain, and discharge lines and reversible flow chokes installed in discharge lines and connected with the hydraulic pump and hydraulic rotor; loading device with the reversible hydraulic pump, drive shaft joined with the shaft of the tested hydraulic motor. Additionally, reversible throttle flow meters are connected via special ports and electric lines to the data acquisition board. The developed stand allows evaluating the technical condition of most widespread models of volumetric hydraulic drives used in modern agricultural and road construction equipment. The stand is characterized by good energy efficiency, simplicity of design, low costs, good technical characteristics that make it competitive. Discussion and Conclusion. The new stand design with the hydraulic loading device allows implementating of the dynamic testing methodology and guarantees high accuracy of evaluating the technical condition of the most widespread Russian and foreign volumetric hydraulic drives at repair and service centres. Further improvement of the evaluating the technical condition of volumetric hydraulic drives is related to the development of specialized software for processing and analysing test results in real-time.
Introduction. Some physical processes active in the electronic engine control systems lead to wear and tear of the system elements. Experience in operating and diagnosing vehicles at the service station has shown that there is the operation of vehicles with failures, many of which subsequently lead to malfunctions of different complexities. The purpose of the study is to apply diagnostics for determining the operational reliability and assessing the technical condition of electronic engine control systems. Materials and Methods. A batch of cars was selected to assess the operational reliability of modern electronic engine control system. There were carried out experimental tests of Skoda Octavia cars with 1.8 TSI CDAB 152 hp Euro5 engine and CDAA 160 hp Euro5 engine. The sample consisted of 60 vehicles. Every vehicle was registered for diagnostics, pre-maintenance and computer diagnostics. After a short test, the vehicle was taken back to the service station and subjected to a detailed diagnosis of the electronic engine control system. Results. The results of analyzing reliability of the main elements of the electronic engine control system have been obtained. It can be concluded that most of the failures of the structural elements of the electronic engine control system occur within the actuators of the system, which have moving elements, sensors measuring the parameters of the system wear out to a lesser extent. The analysis of dependence of failure rates of the fuel pump pressure regulator on operating time intervals has been carried out. Discussion and Conclusion. It was determined that the spark plugs have the least mileage lifetime. At the same time, the failure within the fuel pressure regulator of the car fuel system occurs most frequently (19.8% of total). The resource of this element of the electronic engine control system averages 125,000 km. It is proved that diagnostics using modern technological equipment is effective.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.