• External loading of the motor grader during the operation of the cutting operation and moving the processed surroundings

    pg(s) 69-72

    The main feature of modern earthmoving machines is the execution of a wide range of different operations. At the same time, the loading mode changes and it is characterized by coordinates, values of the applied forces acting on the machine and the regularities of their change in time. In order for the machine to be able to adapt to the listed variables, it must be equipped with the appropriate systems. Existing calculation methods do not allow taking into account the entire range of these effects. In the proposed work, adaptation approaches of earthmoving and transport vehicles to variable operating conditions are analyzed.

  • Monitoring of changes in the roughness of the metal surface after the application of the conversion layer

    pg(s) 66-68

    The article is focused on the study of the integrity of the material that is used in the automotive industry in process of creating joints by combined technology. The article describes the study of the properties of chemically pretreated surfaces by phosphating technology. When creating new surfaces by phosphating, a new type of phosphate layer was used using modern conductive compounds of polyaniline salts. The pretreated surfaces were investigated in terms of structure, 2D and 3D microgeometry, contact angle in relation to the determination of surface wettability and surface energy. The experiment was realized in order to identify the connections between individual factors of the process and roughness characteristics.

  • Traction electric motor for battery-powered electric vehicles

    pg(s) 61-65

    Paper deals with a newly designed three-phase asynchronous electric motor with an application as a traction motor for driving compact battery-powered electric vehicles mainly in urban environments. The main characteristics of the motor are presented. The problems and solutions related to the sizing and optimization of the motor in the design according to various criteria and conditions are analyzed, with energy efficiency being the main determining factor.

  • Self-Excited Acoustic System: enhancing quality control

    pg(s) 40-42

    This article discusses the use of self-excited acoustical systems (SAS) for the non-invasive and quick study of aluminium castings used in the automotive industry. The SAS system is incorporated into the industry 4.0 standard production line and provides valuable insights into the quality and reliability of the aluminium castings. This approach is innovative and aims to enhance the efficiency of the production process.

  • Investigation of the causes to autotruck cooling jacket defects

    pg(s) 36-39

    Defects in the cooling jacket occur for a variety of reasons. This type of details works in severe heat load conditions – fluctuating fluid pressure, mechanical friction and corrosion. The reason for appearance of defects in auto truck engines is often the type of material from which their individual parts are made. For various reasons, they are susceptible to the influence of natural wear, material fatigue and the complex action of many physical and chemical fast-flowing processes.
    One of the main parts of internal combustion engines is the cooling jacket. This part operates under severe thermal stress conditions caused by mechanical friction in contact with the piston, fluctuating pressure where the refrigerant fluid moves, and corrosive action from that same fluid containing antifreeze. The listed factors require the material from which this part is made to have strength and good wear and corrosion resistance – prerequisites for a long service life.
    Therefore, it is important to identify the exact causes of cooling jacket defects and to found ways to prevent them.
    The examined details are analyzed by standard methods for chemical and metallographic analysis, as well as for mechanical tests.

  • Modification of the interior of a passenger car for the needs of fisherman

    pg(s) 32-35

    The main objective of the paper is to design a structure for the interior of the Hyundai ix20 passenger car, which is used by recreational fishing enthusiasts. The authors set out to use the luggage compartment (boot) of the vehicle appropriately for the placement of the multifunctional folding structure. The structure is designed to allow the most effective utilization of each of its components. The individual parts of the structure can, for example, be employed to assemble a table. Moreover, it is suitable for storing things needed for fishing, camping, and travelling. An integral part of the arrangement is a folding bed for two people. One of the design purposes was the comfort and uncomplicated operation of the entire structure by the user. The authors attended to carry out the modification without any interference into the interior or exterior of the vehicle. In addition, one of the conditions was to ensure free access to the components of the mandatory equipment of the car. The authors designed the structure in order to ensure the simple handling of its individual parts along with its simple installation in and removal from the vehicle. From the point of view of safety, a calculation of the stressed parts of the bed structure was performed. Thus, the structure was designed and constructed with regard to minimising the reduction of the original vehicle luggage compartment. In addition, the condition of no interference into the interior or exterior of the vehicle was met.

  • Computational fluid dynamics (CFD) analysis of the divergent part of the Formula Student car restrictor

    pg(s) 9-13

    The FSAE competition is a student engineering competition that involves designing, constructing, and building a small racing car. Students from different universities compete on auto-moto sports tracks. The competition’s judges are eminent experts in marketing, automotive engineering, and racing car engineering. In class IC, engines are used as power units. One of the main limitations is that all intake air must pass through a diameter of 20 mm. One of the main challenges facing student competitors is solving this problem, and the convergent-divergent jet is one of the possible solutions to the problem. In this paper, CFD simulations were used to examine the influence of the divergent part of the restrictor on the total mass flow at the nozzle exit. A diagram of the dependence of the mass flow on the half-angle of the divergent part was obtained. For the CFD simulation, ANSYS Fluent was used, which proved to be very good for examining the mentioned influence.

  • Analysis of planetary gear trains applied in vehicles

    pg(s) 5-8

    The paper presents a theoretical analysis in the field of the application of planetary gear trains in vehicles. The following main areas have been considered: design features of planetary gear trains, specific aspects of the application use of planetary gears in vehicles and possibilities of increasing the efficiency coefficient of these drives. An analysis of the option for investigating these gear sets has been implemented as well. Special attention is dedicated to the options of minimizing energy consumption, taking into account the relevant limitations and operating conditions of planetary gear trains. Conclusions have been deduces. Ideas for future scientific work are presented

  • Surface treatment – effect on spring parts in the automotive industry

    pg(s) 3-4

    In modern automotive engineering, a particular car is composed of various parts that are manufactured using a wide variety of materials and technologies and that meet the high demands of modern customers and environmental norms. In the production process of a specific article for assembling cars, a problem with springs of a certain type is found. During the planned production, assembled products began to show the same defect. The mounted springs fall spontaneously. An analysis of the possible causes was made. A visual examination was made which showed a lack of plasticity, a change in geometry and raised doubts about the thermal surface treatment. Based on the results of the performed measurements and analysis, the possible causes of the problems during production were recognized. Several conditions could have caused this:
    – Two different tools were available at the manufacturer, respectively two different technologies for the production of the springs;
    – The manufacturer used two different sub-suppliers for surface treatment;
    – insufficient corrosion protection;
    The results of the measurements show that despite the geometric deviations of the dimensions, the springs lose their function due to lack or improper surface treatment.

  • Disturbance rejection in a one-half vehicle suspension using a fuzzy controller

    pg(s) 98-102

    Generally, passenger ride comfort can be interpreted as an attenuation of sprung mass acceleration or as peak minimization of sprung mass vertical displacement, while good handling can be characterized as an attenuation of unsprung mass acceleration. This effort devoted to passive suspension design is ineffective because improvements to ride comfort are achieved at the expense of handling and vice versa. Instead, the best result can be achieved by active suspension, i.e. when an additional force can act on the system and simultaneously improve both of these conflicting requirements. Another important goal of the control design is to maintain robustness of the closed loop system. In the paper, fuzzy logic is used to simulate active suspension control of a one-half-car model. Velocity and acceleration of the front and rear wheels and undercarriage velocity above the wheels are taken as input data of the fuzzy logic controller. Active forces improving vehicle driving, ride comfort, and handling properties are considered to be the controlled actuator outputs. The controller design is proposed to minimize chassis and wheels deflection when uneven road surfaces, pavement points, etc. are acting on tires of running cars. As a result, a comparison of an active suspension fuzzy control and a spring/damper passive suspension is shown using MATLAB simulations.

  • Optimal length of a railway curve for a given design speed

    pg(s) 94-97

    The majority of railway projects in our country aim at the maximum utilization of existing railway infrastructure, increase of the operation parameters, frequently at the condition of achieving interoperability. Increasing permissible speeds of trains invariably requires increasing the radii and lengths of curves. However, at small delta angles the use of the minimum design speed radius gives suboptimal results in terms of the total length of the curve. The report presents a parametric method for optimizing the railway curves at small delta angles in view of the necessity of achieving higher speeds on existing lines.

  • LNG fueled ship type “C” storage tank pressure rise particularities related to the bunkering flow

    pg(s) 91-93

    In the proposed publication it is conducted simulation-based experiment with the bunkering process of type “C” LNG containing tank. According to the specific features of the LNG bunkering process it is analysed the nature of the boiling off mechanism of the cryogenic fluid during bunkering transfer. The attained data by the experiment is analysed including the specific condition of heat ingress simulation. On the base of the results there are stated conclusions and recommendations to the ship operators related to the limiting conditions of the pressure vessels operation as it is the type “C” tank.