The invention relates to a method for testing different substances in a combustion engine and to a combustion engine, especially a big diesel engine, for applying the method.
In this context big diesel engines refer to engines of such an output range so as to be applicable for heating power plants, or for auxiliary or main marine engines, for example. In accordance with a known testing technique different lubrication oil, cooling substance and/or fuel grades are tested in one or several engines one grade at a time. When this kind of method is used testing takes a lot of time. The method is also expensive due to considerable investment and operation costs caused by the engines. In these respects the problems are especially great when one wishes to examine the effect created jointly by several of the above mentioned substances with different grades thereof.
An aim of the invention is to essentially eliminate the drawbacks apparent in the known technique. A further aim is to provide an engine applicable for testing by using relatively simple measures and arrangements for modification of a conventional engine construction.
Thus, in accordance with the invention, by separating the medium systems and circuits of one or several cylinders of the engine so as to be independent of one another, different medium grades can be tested simultaneously by means of the same engine. Separating can relate to lubrication medium, cooling medium as well as fuel systems. By extending this kind of separating to relate to several or even all of the cylinders of the engine as well as to said different mediums, it is possible to simultaneously test by the same engine separate lubrication medium grades, different cooling substances and different fuel grades and to obtain test results about the separate mutual combinations thereof substantially quicker than by using previously known testing methods. When testing is accomplished in one and the same engine the results are mutually better comparable, because the conditions between separate cylinders of the same engine are more similar than the conditions in cylinders of separate engines.
Especially for testing different lubrication oil grades in a cylinder, that part of the crankshaft and of the crankcase of the engine which corresponds to the selected cylinder is tightly sealed by means of partitions from those parts of the crankshaft and of the crankcase corresponding to the adjoining cylinders and said part of the crankshaft is provided with separate supply and distribution channels between said partitions. By arranging the partition to extend to the oil pan and by arranging the crankshaft to go tightly through the partition the lubrication oil under test can easily be arranged to circulate fully independently of the other cylinders and the lubrication circuits thereof. It should be noted that in practice the lubrication oil can advantageously be arranged to be supplied in a known way through the crankshaft, the connecting rod and the piston into the cylinder and back therefrom into the crankcase, whereby the lubrication oil serves at the same time as a cooling substance. The supply can easily be arranged as is disclosed in the Finnish patent No. 53165.
In addition the engine can naturally be provided with separate channels arranged in the engine block for the cooling substance, which channels, in accordance with the invention, are arranged for each cylinder separately with regard to one another. Hereby, at the same time, separate properties of the cooling substance can with advantage be tested, for instance the influence of different temperatures of water, when used as cooling substance, on the operation of the engine. Likewise by providing one or several cylinders with a separate fuel feeding system, when desired, different fuel grades can be tested simultaneously together with different lubrication substance and cooling substance grades.
In the following the invention is described more in detail with reference to the attached drawing, in which
FIG. 1 shows as a perspective view an engine according to the invention partly in section,
FIG. 2 shows as a sectional view, at the position of one cylinder, the crankshaft and the crankcase of the engine of FIG. 1 sealed from the other parts of the engine as presumed by the invention,
FIG. 3 shows as a perspective view, at the position of one cylinder, the crankshaft and the crankcase of the engine of FIG. 1 sealed by means of partitions from the other parts of the engine.
In the drawing the reference numeral 1 indicates an engine block, 2 a crankcase, 3 a crankshaft, 4 a cylinder liner and 5 an oil pan. The crankshaft is supported by means of main bearings 8. The support for the bearings is arranged in accordance with a principle, more clearly disclosed in the Finnish patent No. 53165, by making use of a main bearing seat 7 and a telescopic support construction 6, which for its part is at the other end fixed to an oil duct 13 of a lubrication system. The crankcase 2 and the crankshaft 3 are for the part of said cylinder of the engine tightly sealed from the other corresponding parts of the engine by partitions 9a and 9b supported to one another and by additionally using gaskets 10, 11 and 12.
The lubrication oil system itself includes said oil duct 13, which by means of plugs 14 is sealed from the corresponding oil duct included in the lubrication system for the other cylinders. The supply of oil takes place by pumping through a pipe 15 (disclosed only schematically). Through openings 16 in the oil duct the oil is further transmitted from the oil duct 13 through an inner duct 17 in the support structure 6 and 7 into the main bearing 8, from there into ducts 18 and 19 made in the crankshaft 3 and further through an opening 20 into a connecting roll 21. Through the connecting rod the oil is transmitted in a known way (not shown in the drawing) through a piston pin and a piston into the cylinder liner 4 serving simultaneously both as lubrication medium and cooling medium. Through the cylinder liner the oil flows back into the crankcase to be recovered for recirculation. As shown in FIG. 2 by this means the lubrication oil system of a conventional big diesel engine can in a simple way be separated for the part of separate cylinders to be an entity of its own, in which different lubrication oil grades can be circulated and tested quite independent of other cylinders.
The provision of a cooling system for each cylinder for its part can in practice be accomplished for instance by sealing the cooling water ducts of the cylinder from the other cooling ducts and by arranging in the engine new fuel supply positions and outlets respectively and independent means to provide the supply and circulation. Further, when there is a desire at the same time to examine different fuel grades the cylinders are correspondingly also provided with fuel supply means of their own. By this means it is possible in the same engine at the same time to test separate lubrication substance, cooling substance and fuel grades either separately or in any combinations for examining the general effect thereof on the operation of the engine.
The invention is not limited to the embodiment shown but several modifications are feasible within the scope of the attached claims.