Research of methods and development of measures to improve comfort conditions for a passenger car
Students Name: Ludyn Vasyl Volodymyrovych
Qualification Level: magister
Speciality: Motor Vehicle Transport
Institute: Institute of Mechanical Engineering and Transport
Mode of Study: full
Academic Year: 2022-2023 н.р.
Language of Defence: ukrainian
Abstract: Improving the design of the car in the direction of increasing comfort encourages manufacturers to take into account the individual requests of consumers as fully as possible. Automatic transmissions, electric power steering, climate control, adaptive suspension and lighting are widely used. However, its climatic, vibrational and acoustic components will serve as defining, basic indicators of comfort. Vibration and noise isolation of the car becomes relevant when the roar of the engine, the sounds of the clutch of the wheels with the road surface, creaks, etc. are detected in the cabin. In this case, you don’t have to think about comfort and peace of mind during the trip. In cars of the lower and middle class, noise insulation material is either completely absent, or its amount is minimal. The main reason for this is the desire of the manufacturer to save on insulating components. If we take into account the volume of production, the monetary costs of the car plant will be higher. The second reason is the reluctance of the manufacturer to devote time to the installation of noise-insulating materials. The third reason is the extra weight (several tens of kilograms) that complete vibration and noise isolation adds to the weight of the car. As a result of the rapid motorization of Ukraine in modern conditions, there has been a great demand for noise and vibration insulation. In accordance with the demand, an offer appeared in the form of various accessories and materials designed to provide additional noise and vibration isolation, which formed a separate market niche. Object of study — sources of vibrations, air and structural noise of the car. Scope of research: dependence of vibration and noise levels on the nomenclature and volume of vibration and noise protection materials. Goal of research: determination of the results of additional vibration and noise protection of European cars in Ukraine. The first section issues of equipping the car with a number of comfort systems with centralized and decentralized control are considered. Presented are modern interpretations of the concept of vehicle comfort; the most important components of comfort are singled out; a list of the main normative indicators of climatic, vibration and acoustic comfort is provided; the task of research and improvement of two interrelated components - reduction of vibrations and noise - is formulated. The second section systematized the main and secondary sources of noise and vibration generation, including in case of malfunctions of the internal combustion engine, running gear or brakes; the main methods of eliminating the causes and effects of excessive sound and vibration load are described; a number of types of research on the vibration and sound properties of vehicles are considered, including foreign NVH tests on noise and vibration optimization, which are sought for further practical implementation of the characteristics of the most common vibration and noise isolation materials. The third section requests for a comprehensive improvement of acoustic and vibration comfort parameters were submitted, equipment was selected for researching the levels of structural noise generated by various sources, and the results of the implementation of the listed requests in practice were also submitted. In the work, an experimental application of the proposed noise insulation measures for cars was carried out in the following areas: in the area where the wheel arches were treated, a reduction in the level of wheel noise, the effects of overcoming road irregularities and stones, suspension work was observed; in the area of the door, the level of external noise has been reduced. After impacting the car, the noise level in the low-frequency spectrum dropped, especially at frequencies up to 400 Hz. Measurements were taken while recording data in the cabin. Impacts from the positions of vibration and noise isolation in the cabin and on the arches of both pairs of wheels improved the overall comfort of the driver and passengers. Keywords: vibration, acoustic comfort, noise isolation of the car, NVH (Noise, Vibration, Harshness).