STUDY OF THE INFLUENCE OF ROAD RESISTANCE ON THE FUEL CONSUMPTION OF A PASSENGER CAR WITH AN AUTOMATIC TRANSMISSION

One of the directions in the modern automotive industry is related to optimizing processes of the working cycle of internal combustion engines, which is related on another hand to reducing fuel consumption. This article presents calculation results of fuel consumption of a passenger car Honda Accord with automatic gearbox which are based on experimentally obtained power characteristics by using a chassis dynamometer DYNO COSBER. The fuel consumption was determined at different speeds of the car on a road without a slope and with 2%, 4% and 6% slope by using the chassis dynamometer and diagnostic equipment. The results of calculations about the influence of road resistances on fuel consumption were compared and analyzed with those obtained from measurements

SIDE SLIP OF WHEELS WITH LOW AND ULTRA-LOW PROFILE TIRES OF A PERSONAL CAR NEGOTIATING A TURN

This article studies the influence of the speed of a car with low and ultra-low profile tires, 14ʹʹ and 16ʹʹ, negotiating a turn through an interactive software system developed by us in the MATLAB environment. The changes of the normal and lateral loads of the wheels are obtained and the characteristics of the side slip angle (known as side slip) of the pneumatic tires are determined. Taking into account the side slip of the wheels, the software determines the center of the turn. The characteristics for the normal and lateral loads and of the side slip of the wheels for both types of tires are given. The influence of the tire profile on the handling characteristics is analysed. Recommendations are proposed for a personal car’s motion in a turn with both types of tires

COMPARISON OF NATURAL FREQUENCIES OF A MACPHERSON SUSPENSION ARM USING DIFFERENT BUSHINGS

The main function of the suspension system and its components is to absorb vibrations when the vehicle moves over bumps and to provide its stability in the different operating modes. Some of the vibration parameters are natural frequencies and mode shapes. This paper presents the results of the natural frequencies of an arm of the MacPherson front independent suspension using different bushings. For this purpose, three-dimensional geometric model of the arm was created and its frequency analysis was performed by Finite Element Analysis (FEA) using SolidWorks software. The obtained results of the natural frequencies of the arm with different bushings by FEA were presented and compared with those obtained experimentally

MECHANICAL BEHAVIOR AND STIFFNESS OF A POLYURETHANE BUSHING OF A PASSENGER CAR SUSPENSION

Suspension bushings play an important role in reducing vibrations, minimizing noise, absorbing road irregularities, and controlling joint movements. Polyurethane bushings, in particular, contribute to improved vehicle handling, exhibiting lower moments of inertia and greater strength under increased loads. However, this enhancement in performance may come at the expense of reduced ride comfort. This paper presents the results of a study on the mechanical characteristics of polyurethane material and the stiffness of bushings made from the same material, specifically in the context of the MacPherson front independent suspension. To achieve this, mechanical tension tests were conducted on polyurethane specimens, obtaining stress-strain curves. Additionally, a three-dimensional geometric model of the polyurethane bushing was created using the SolidWorks software. The paper presents the results of bushing stiffness obtained through nonlinear Finite Element Analysis (FEA). Experimental determination of radial stiffness was also performed, and the results were compared for validation

INTERACTIVE SYSTEM FOR STUDY OF CAR'S MOVEMENT WITH LOW AND ULTRA-LOW PROFILE TIRES IN A TURN

In this paper an interactive system for the study of the movement of a car in a turn is proposed. The interactive system is implemented on a modular principle in the MATLAB environment. The system operates on an algorithm, taking into account the current redistribution of the vertical wheel load and its effect on the characteristics of the lateral slip of wheels with low and ultra-low profile tires. The capabilities of the interactive system are visualized with graphical dependencies

STRENGTH AND FREQUENCY ANALYSIS OF THE LOWER ARM OF A DOUBLE WISHBONE SUSPENSION OF A PASSENGER CAR

One of the main elements of the suspension system is the lower control arm, which serves to transmit horizontal forces from the wheels to the chassis, while also defining the nature of the wheel movements relative to the chassis and the road surface. The implementation of guiding, elastic, and damping devices requires a comprehensive modelling of the vehicle\u27s motion during the design stage. This paper presents results from static strength analysis and frequency analysis of the lower control arm of an independent front double-wishbone suspension of a passenger car. For this purpose, a three-dimensional geometric model of the lower control arm was created, using the Honda Civic as a prototype for the passenger car. The loads under various operating conditions necessary for conducting static analysis were determined. The Finite Element Analysis (FEA) was employed using the Simulation module of the SolidWorks software to solve the problem. Stresses, displacements, natural frequencies, and modes of the control arm were determined. The results were compared with experimentally obtained data for the natural frequencies

STIFFNESS ANALYSIS OF THE RUBBER BUSHINGS OF MACPHERSON AND DOUBLE WISHBONE SUSPENSIONS

The rubber bushings are important components of automotive suspensions. These bushings play an important role in reducing noise and vibrations, enhancing ride comfort, and ensuring smooth vehicle motion. Therefore, investigating their elastic is of significant interest. This article presents the results of a force/torque analysis conducted on rubber bushings used in MacPherson and double wishbone front independent suspensions. To achieve this, three-dimensional geometric models of the rubber bushings were created using the SolidWorks software, employing two types of passenger cars as prototypes. The results were determined through Finite Element Analysis (FEA), and the radial force for all bushings was experimentally measured. The obtained results were then compared for validation

FREQUENCY ANALYSIS OF AN ARM OF MACPHERSON SUSPENSION ON A PASSENGER CAR

The smoothness, ride comfort, safety and handling of the car depends on the manner of suspension design and its corresponding details. One of main functions of the arm and the rubber bushings mounted on it is to reduce the vibrations and the noise transferred from the road to the passenger car components. This article presents the results of a frequency analysis of an arm of the MacPherson front independent suspension. For this purpose, three-dimensional geometric models of the arm and rubber bushings are created via finite element analysis (FEA) software SolidWorks, where Skoda Octavia passenger car was used as a prototype. The axial, radial and torsional stiffness of the rubber bushings were determined through analytical dependences and FEА. The obtained results had been used for calculation of the natural frequencies and mode shapes of the arm which were compared with experimentally obtained data