INMATEH - Agricultural Engineering

8

Authors: Sfîru R., Meca A., Cârdei P., Muraru V., Mihailov N., Atanasov At.

The article presents an optimizing method of agricultural equipment selection by users, dealing with databases and different objective functions, all finally materializing in benefits of energetic nature.

8

Authors: Stefănoiu M.D., Cârdei P., Vlădut V., Boruz S., Lazar S., Fodor M.

The problem of the optimization of working regimes of agricultural aggregates remains one of current, even if their approach began with over a half of century ago or even earlier. The reasons for the problem remains in the study are several: difficulty of verifying experimentally the optimality of solutions, the existence of some solutions with certain errors in the specialty literature of reference, the complexity of mathematical models on which is solve the problems of optimality and which introduce new parameters, necessary for obtaining of some functions goal which would have optimal points in the strict sense of local extremum, parameters which however are not usual and are difficult to determine by measurements. This article starts from a known method from the literature of the '70, corrects the solution and modifies slightly the mathematical model in order to make its calibration on a specific case so that the final results–the coordinates of the optimal point - to be obtained numerically and compared with data from the literature.

8

Authors: Ciupercă R., Popa L., Lazăr G., Drăgan R., Aliyev Ch.

The paper presents a comparative study on mechanized process of planting vegetable seedlings, performed by two types of machines among the most common and used vegetable farm machines, respectively machine with a section equipped with rotative distributor with buckets and a second type- with section endowed with supply chain and planting flexible disks. After the analysis performed, the advantages and disadvantages of two machine types studied have been found out, in terms of technology of vegetable seedling planting.

8

Authors: Cârdei P., Kostadinov G.

The article continues to present some results related to those in [3], thoroughly studying the results of aggregates working optimization operating mode designed to soil works, their significance and interpretation.

10

Authors: Danciu A., Brătucu G., Vlădut V., Brkic M.

Because of machining precision by pairing and running in (lapping) of the conjugated parts (piston and cylinder), the manufacturers, in order to not reject several parts assembled have recourse to execution of several diameters for these parts so that to be respected the conditions of ovality, conicity and the clearance between the conjugated components (max. 0.5÷2μm). To highlight the size and shape of the injection pump elements (piston and cylinder) worn-out after the completion of an operating cycle on the engine, were taken randomly from a sample of 141 injection pump elements, studying the distribution of these dimensions. The study of sizes distribution or of the effective deviations from shape of pistons and cylinders (bushings) of the worn off injection pumps elements, had as scope the knowledge of dimensions range of these, in order to check the possibilities to re-establish the operational state of these by lepping and re-pairing, pursuing and the determination of the number of measuring pneumatic completes, required in the resettlement process of the operational state of these. The statistical and mathematical processing aimed to: - determination of average diameters on two directions and in each of the three plans of measurement (both for pistons and for the cylinders of elements); - the determination of pistons ovality and cylinders respectively in the three plans of measurement; - the determination of averages for the piston conicity (cmed)) and for cylinders (CMED); - the determination of averages of the clearances in the three measurement plans for the conjugated parts; - sorting in ascending order of the pistons and cylinders; - highlighting the possibilities to restore the operating status of injection pump elements.