Search

The subject of the article is the research of the production of a robot base using CAM programming, Autodesk Inventor HSM software, followed by the generation of G code – NC program. The research specifically examined the accuracy of measurement and evaluation of roundness with coaxiality on a 3D measuring device Thome. The surface roughness of the circular holes was measured using a Mitutoyo SJ 400 roughness meter. The maximum deviation of the roundness of the diameter D56H7 measured was 0.011 mm, and the diameter D72H7 measured was 0.013 mm. The coaxiality deviation of the diameters D56H7 and D72H7 measured was 0.017 mm.

The paper describes the structural design of a laboratory device that allows for presenting operation, simulating work procedures and checking functionality of the elevator “rope sensors” when equalizing different tensile forces in partial ropes of a rope system of traction elevators. The laboratory device is modified for checking operations of commonly used rope sensors. In an overwhelming number of cases, elevator technicians use them for setting up the unequally distributed tensile forces in elevator ropes. The device is equipped with three, mutually attached pulleys, over which the rope is installed. The unknown tensile force in the rope is determined by an “indirect method”, i.e. from the resultant of the forces of the rope bent over the pulleys, which have an effect on the force sensor. The tensile force along the rope axis can be determined numerically, but also experimentally, from the inclination angle of the rope installed on the pulleys, diameter of the pulleys, diameter of the rope and the force detected by the force sensor of the stretched rope. The paper presents experimentally obtained tensile force values at the rope sensor, deduced from stretching the rope. The paper also describes the procedure for determining the measured load in the rope by rope sensors of the SWR, SWK and RMT-1 types based on the variable axial force in the rope.

This article deals with the adjustment of a 3D printer for laser engraving and material cutting. The print head can be fitted with a solid laser diode module, which achieves a compact size while retaining its useful power. Two paths lead to the use of such a concept. It is possible to equip the existing print head with a module, which also brings a number of disadvantages such as, for example, the reduction of the printing space or the need for a suitable mounting design. A more elegant solution is to consider this in the design of a 3D printer and design a system to exchange the print heads for 3D printing and laser engraving. Such a solution allows full utilization of the workspace and simple installation of the effector for the required type of work. According to the installed power of the laser diode, it is possible not only to engrave but also cut material such as thin wood, veneer or acrylic glass. The use of such a machine is not only for graphic elements but for the creation of various stencils, boxes or simple models, which can be made up of plastic-burning pieces. The laser module is controlled by a driver, which is designed for the device. This is connected to a 3D printer control board. It is, therefore, necessary for the control board to have at least two pins, which can be controlled after adjusting the control firmware. Most laser modules are normally equipped with an adjustable lens, which is used to concentrate the focus of a laser for the given distance against the worktop. Thus, the modified 3D printer can perform its function as a multi-purpose CNC machine, while a basic platform similar for both devices is used.

The article deals with the description of the production of a shaped part composed of an outer pyramid and cylindrical surface, of inner cylindrical surfaces of different diameters and of an inner tongue groove. It describes the proposed tools and tool holders resulting from the technological process. In order to meet the required tolerances and shape deviations for the given component, the CTX alpha 500 two-spindle multi-axis CNC lathe was chosen for its production. Its control system enables the workshop method of programming and simulation of individual operations in automatic mode or in block-by-block mode. The design of the selected CNC lathe enables the machining of rotary parts in one clamping, which is ensured by the right and left spindle with chucks. The surface quality of the pyramidal surface and the internal diameter of D18H8 was measured using a Hommel Etamic W5 roughness gauge. The measured roughness values for the hole were: D = 18H8, Rz = 3.007 μm, Ra = 0.729 μm and for the pyramidal surface: Rz = 1.527 μm and Ra = 0.329 μm.

The paper presents a construction design and results of laboratory tests of so-called mechanical stress detectors, which can be used to detect the deformation of the steel structure of a crane and to amplify the mechanical signal from the effect of the so-called crane skewing, which is included among occasional loads acting on the crane. The values of the relative elongation of the detectors corresponding to the magnitude of the instantaneous tensile force were obtained by conducting experimental mechanical tests. Detectors of a known extent of deformation were installed on a two-girder overhead crane bridge, where they measured axial forces generated during the controlled deformation of the crane bridge. In practice, the instantaneous values of the axial forces recorded by the individual detectors make it possible to regulate the speed of the crane drive wheels and thus eliminate, in a relatively short time, the undesirable effects of deforming the crane bridge and friction of the crane wheels on the sides of the rail heads. [ABSTRACT FROM AUTHOR]

In the production of building materials and construction materials, continuously operating conveying equipment is commonly used, including roller conveyors. Roller conveyors are devices designed for horizontal, slightly ascending or descending transport of piece products moving on a system of rotating rollers of different shapes (cylindrical, conical, disc, pulley or according to the profile of the conveyed object). The rotating rollers are placed in the track frame (supporting structure), which can be either stable, relocatable or adjustable (height and length adjustable, so-called scissor conveyors). An analogue of the roller conveyor is the pulley conveyor, where instead of rollers, discs - pulleys are mounted on a non-rotating axis. Several discs are installed on the axis with gaps. The pulleys on adjacent axes overlap so that there is no continuous gap. The track is used for handling flat building parts and objects such as metal sheets, glass panes, furniture parts, etc. When transporting item building materials or bulk building materials placed in storage boxes which are transported on a powered roller track on pallets, a driving force is required depending on the angle of inclination of the roller track, the weight of the load, the number of rollers on which the load rests and the coefficient of shear friction during movement. The paper presents a laboratory device that has been designed to detect the adhesion force during the transport of piece loads by a roller conveyor. On the implemented device, it is possible to determine in laboratory conditions the amount of resistance to the movement of the load on the driven roller conveyor depending on the weight of the load. The paper presents measured values of the shear friction coefficient during the movement of a steel storage box on a driven roller track. In this paper, a driven roller track is used for laboratory tests, where the drive of the rollers is implemented by so-called short chains. In addition to horizontal tracks, this chain drive allows you to drive rising tracks with variable gradients or even rising curved tracks.

Transport above the limit angle of transport inclination provided using belt conveyors can be done in several ways. If we omit the methods based on an increase in the contact force of the transported material in relation to the surface of the conveyors belt and increase in the coefficient of friction, we will focus only on the method based on the principle of preventing the movement of the transported grains on the surface of the conveyors belt. This principle uses transverse cleats that prevent the movement (sliding or rotation) of material grains along the entire length of the conveyor belt, which is inclined at a high angle to the horizontal plane. Material grains are transported on the surface of a conveyor with cleats, distributed with a regular spacing along the entire length of the endless loop of the conveyor belt. To prevent material grains from falling of such a belt, corrugated sidewalls are fitted on both edges of the conveyor belt. This paper describes two variants that take into account the mutual position of the cleats in relation to the corrugated sidewalls. For each of the variant, the relationship is given with which it is possible to analytically quantify the volume of the bulk loose material batch that is spread over the area of the cleat in the vertical section of this conveyor belt design. The results of the measured values concerning the height of the loose material pile that were taken using laboratory instruments are listed in the tables and compared with the theoretically calculated values. Key data that must be known to calculate the pile height, and the volume of the transported material batch represent the exact value of the angle of repose for the loose material. The angle of repose of a particular loose material does not acquire a constant size, as it changes from its maximum (static angle of repose) depending on the shaking, flattening or absorbing liquid to its minimum (surcharge angle). The paper presents geometric shapes of batches for the transported material used for both limit values of the angle of repose.

In a parking house with KOMA TOWER computer-controlled automated parking system it happens that a control system is locked out of service after a pallet has failed to reach the required position during the shifting of pallets, loaded with cars, into rack cells.

The article presents the experimental measurement of the mining equipment motion resistance in the Mining Plant 1, the Lazy mine location district. The procedure of the experimental tests was as follows, one of the transport vessels was fitted with a weight of a known weight. The mining cage was loaded with the weight and pulled up in the traffic pit to the required depth, then the mining equipment was released and, using the IRC rotation speed sensor attached to the rope drum shaft, the travelled trajectory and the instantaneous mining cage speed were recorded with an indirect method. Upon reaching the speed of the transport vessels, a maximum of 3.15 m/s, the vessels were equipped with the mining equipment brakes and the transport vessels were slowed down to zero speed. From the recorded data in the PC memory, ie initial positions of both transport vessels, travelled trajectory and instantaneous speed values, the values were consequently calculated and added to the stated tables.

The article deals with a theoretical expression of resistances that occur in pushing loose material off the conveyor belt surface with a single-sided plough. The working branch of a belt conveyor is designed in a flat, single-idler arrangement. Theoretical prerequisites and derivations are practically tested on a belt conveyor model in the laboratory of the Department of Research and Testing of the Institute of Transport at the Engineering Faculty of VSB-TU in Ostrava.