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EN
Distributions of mechanical and thermal stresses in a plunger of the high pressure die casting machine with a horizontal shot sleeve have been considered for a flat thermal stationary problem. An axial pressure of the plunger pressing in the technological process has been accounted for as well. Principal and equivalent stresses have been determined within two different hypotheses on the strength of materials, including one theory covering various allowable stresses in tension and compression. Four plunger material variants have been analysed.
EN
The study discusses the thermo‑mechanical stress distribution in the plunger of a cold chamber casting machine with a horizontal casting chamber in the stationary aspect. The main stresses as well as the reduced stresses were determined for four different strength hypotheses, two of which took into account different acceptable maximal tensile and compressive stresses. For comparative purposes, the calculations were performed for three different construction materials used for cold chamber pressure machine plungers: grey pearlitic cast iron, high silicon bronze and beryllium bronze, as well as one more type of bronze, which has not been used for plungers so far, i.e. aluminium‑iron‑nickel bronze, constituting the initial alloy for the newly‑developed complex bronzes with high wear resistance and elevated strength.
EN
Precision surface assemblies can be found in the two locations in a fuel system of a diesel engine. These parts are the pumping section in an injection pump and the injector nozzles. In this paper the authors present the results of surface topography measurements of precise surface assemblies of some fuel injectors. The measurements have been made with the atomic force microscope (AFM) NT-206. The results of surface topography measurements were presented in the form of 2D and 3D images and also as surface roughness profiles in some selected cross-sections of the investigated surfaces. It has been also shown cumulative roughness height distribution and roughness height distribution as well as Minkowski volume (first Minkowski functional). After scanning the surface on the atomic force microscope, the obtained data were processed with the SurfaceXplorer ® 1.311 and Gwyddion 2.35 software. The study concerned some new injector nozzles and also injector nozzles after a certain time of operation. The side and the conical precise surface assembly of the injector nozzle body and needle were tested. The atomic force microscope NT-206 allows to perform a surface scan of the sample with maximum dimensions of 32x32 μm and a maximum height of roughness ± 1 μm. Scanned area was divided into 256x256 measurement points, while the measurement was carried out in a static (contact) mode. The results presented in this paper also includes the calculated values of Ra, Sa (roughness average) and Rq, Sq (root mean square roughness) surface roughness parameters and the value of the skewness Ssk (Rsk), kurtosis Sku (Rku) and maximum distance between the lowest valley and the highest peak of investigated surface – Rt. The obtained data allow evaluating the degree and type of wear of tested surfaces on the micro-scale.
EN
Precision surfaces in a diesel engine’s fuel system are used in the two components. First one is the pumping section in the injection pump. The second ones are injectors. In this paper authors present results of the topography measurements of the surface of plunger and barrel assembly in the injection pump pumping section. The measurements were performed using the atomic force microscopy (AFM) NT-206. The measured surface topographies were shown in the form of two and three-dimensional views of selected areas of the investigated surfaces. There are also presented the profiles of the selected area cross-sections as well as roughness height distribution and cumulative height distribution of roughness. Additionally, the basic parameters describing the surface roughness, such as: a roughness average Ra, a root mean square value Rq of roughness, a skewness Ssk (Rsk) and kurtosis Sku (Rku), are also specified. The samples (plungers and barrels), which have been measured, come from the injection pump pumping section as a new ones and after estimated period of operation time. The lateral precision surfaces have been measured. The atomic force microscope NT-206 allows to perform scanning of the measured surface with maximum are dimensions of 32 μm x 32 μm and maximal roughness height of ± 1 􀁐m. Scanned surfaces was divided into 256x256 measuring points and the measurements were performed in the static (contact) mode. After surface scanning on the atomic force microscope, the data was calculated in the SurfaceXplorer® 1.311 or Gwyddion 2.35 software. In this paper, only selected surfaces from the several dozen performed scans are shown. The obtained results allow to determinate the degree and type of wear of tested surfaces at the micro-level.
EN
A novel type of pulsed electromagnetic actuator is presented and modelled. Its plunger consists of two cylindrical parts made of classical magnetic material and permanent magnet, respectively. Its motion is controlled by short current pulses of the prescribed amplitude. The paper starts with the definition of the technical problem and formulation of its mathematical model. This model is then solved numerically and the whole methodology is illustrated by a typical example, whose results are discussed.
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