Method for modeling a bore chamfer in a hull within the scope of submarine shipbuilding for welding-in of outfitting Part 2 Mathematical description of hole groove in spherical and conical sections of hulls

Статья является логическим продолжением первой части (№1, 2020), в которой была предложена методика геометрического моделирования кромок отверстий на цилиндрических участках обечаек. В этой части рассмотрено математическое описание кромок отверстий в сферических и конических участках корпусов. Показано, что поверхность кромки отверстий может быть описана как дважды косой цилиндроид или косой коноид в зависимости от требований к разделке.Полученные выражения для описания кромок отверстий могут быть представлены в аналитическом и матричном виде (в однородных координатах). Также полученные выражения могут быть использованы в качестве промежуточного этапа в предложенной методике проектирования технологических комплексов. Отмечено, что получаемую криволинейную направляющую разделки кромки можно использовать в качестве связи между обрабатываемым изделием и обрабатывающим инструментом для механической обработки кромок отверстий с помощью нестационарных технологических комплексов. The article is a logical continuation of the first part (No. 1, 2020), in which a method for geometric modeling of hole grooves on cylindrical sections of shells has been proposed. Mathematical description of hole grooves in spherical and conical sections of hulls has been studied in the current part. It is shown that surface of a hole groove can be described as double oblique cylindroid or oblique conoid depending on groove preparation. Received expressions for describing the hole grooves can be shown in analytical and matrix form (in uniform coordinates). Also received expressions can be used as an intermediate stage in the proposed methodology for the design of process systems. It is noted that the resulting curvilinear groove guide can be used as a connection between the workpiece and the machining tool for machining the hole grooves using non-stationary process systems.

A New Millimeter Wave Mixer Based on the Groove Guide

A novel groove guide mixer was proposed. The key features of this mixer are large dimension and good signal-to-noise performance. The shell of this mixer is made up of a novel waveguide, the groove guide. A planar logarithmically periodic antenna was installed in the guide. It received signals in the guide and transmitted them to the mixer diode. A compact multi-section coaxial filter was arranged to lead the intermediate frequency signal out of the shell. At the end of the mixer, a matched terminator is adopted to absorb millimeter wave signals. One model of this mixer was designed, fabricated and tested at 93.069GHz. It works well on millimeter wave band.

The Novel Design of Full-Balancing Mechanism for Single-Cylinder Diesel Engine

One new sliding-block balancing mechanism is proposed for the single-cylinder diesel engine. In the new mechanism, the sliding block is installed against the engine piston. The reciprocation trajectory of sliding block is collinear with the piston trajectory, while sliding block and piston move in the opposite direction, just like two opposite crank connecting rods. The new mechanism includes the crankshaft, connecting rod ring, the slider and the guide components. Through the bearing, connecting rod is installed in the eccentric journal of the crankshaft. The circular connecting rod is in the accurate guiding surface of the slider; and the guide pins are in the guide groove. Guide rod connects with supporting shaft through the guide hole of the slide. The optimized parameters for the sliding block show that the ratio of eccentric distance of the eccentric journal to the length of the connecting rod is equal to the ratio of crank radius to connecting rod length. The appropriate results can balance both the centrifugal inertia force and the reciprocating inertia force generated by piston group. Even the complete balance of the first and second-order reciprocating inertia forces can be obtained, which can reduce the vibration and noise of diesel engine.