RU2078980C1 - Diesel engine fuel feed system - Google Patents

Abstract

FIELD: mechanical engineering; fuel system devices of diesel engine. SUBSTANCE: fuel channel connecting hydraulic chamber with circular groove on guide surface of spray tip or shutoff member of nozzle is used to act onto injection parameters depending on speed and load of diesel engine. EFFECT: higher economy. 2 cl, 2 dwg

Description

 The invention relates to the field of engine manufacturing.

 A known system for supplying fuel to a diesel engine [1] comprising a nozzle with a locking member, a spring, a movable element made in the form of a piston placed in a hydraulic chamber and connected to the last pressure source.

 The disadvantages of this system are the presence of an external pressure source, the use of two types of liquids, and the fact that during the operation the pressure of the fuel injection start is not controlled depending on the variable loading mode of the diesel engine.

 The use of an external pressure source and connecting piping complicates the design of the system for supplying fuel to diesel, increases the loss of engine power to drive auxiliary units and increases the likelihood of equipment failures, and the use of two types of liquids leads to their mixing due to leaks through the gaps of precision pairs. The regulation of the injection start pressure depending on the high-speed mode of the diesel engine does not provide the optimal pressure for the start of fuel injection into the diesel engine at a low engine speed and large cyclic feeds.

 The invention is aimed at simplifying the design of the system for supplying fuel to a diesel engine and increasing its efficiency by affecting the injection parameters depending on the speed and load conditions of the diesel engine.

 The objective is achieved in that the nozzle has a fuel channel connecting the hydraulic chamber to the annular groove on the guide surface of the atomizer or the shutoff element of the nozzle.

 Unlike the prototype, the source of external pressure and connecting pipelines are excluded from the proposed system, and one type of liquid is used as the working one. In addition, the fuel supply system regulates the injection start pressure, and therefore the maximum injection pressure, depending also on the diesel loading mode, improving the quality of fuel atomization with increasing load and a related decrease in the diesel engine crankshaft speed.

 Figure 1 shows a system for supplying fuel to a diesel engine. The system for supplying fuel to a diesel engine comprises: an injector 1 with a locking member 2 installed in the atomizer 3, a spring 4 for loading the locking member 2, a movable element 5 made in the form of a piston located in the hydraulic chamber 6, a connecting channel 7, and an annular groove 8 on the guide of the atomizer 3 or the locking element 2 (figure 2). The nozzle 1 is connected by a heating pipe 9 to a high pressure pump 10.

 The system for supplying fuel to a diesel engine operates as follows.

 Starting and idling of the diesel engine occurs at an injection start pressure corresponding to the preliminary tightening of the spring 4, adjusted to a lower start pressure of the locking member than in the nominal mode of operation. The fuel flowing through the gap between the guides of the locking member 2 and the atomizer 3 acts on the movable element 5 made in the form of a piston and placed in the hydraulic chamber 6. The pressure from the pressure of the fuel flows the movable element 5 transfers to the spring 4 loading the locking member 2.

 Since, with increasing diesel engine speed or increasing load, both the maximum and average fuel injection pressures increase, the pressure of the fuel leakage is determined by the magnitude of the cyclic feed and the pump shaft speed.

 The degree of impact and the rate of change of impact on the movable element 5 is also determined by the length of the guide part of the locking member 2 to the annular groove and the diametrical gap in the precision pair of the locking member 2-atomizer 3.

 Therefore, the force with which the movable element 5 is made in the form of a piston acts on the spring 4 will depend on the speed and load conditions of the diesel engine.

 The lowest pressure at the beginning of injection will be at low cyclic feeds and the minimum crankshaft speed, which increases the uniformity of fuel supply along the diesel cylinders and in cycles, and allows to reduce the minimum stable number of revolutions of the crankshaft.

 With increasing speed and increasing load, the force with which the movable element 5 acts on the spring 4 increases, due to the increase in pressure of the fuel flow. This will lead to an intensification of the mixture formation process.

 Thus, in this system for supplying fuel to a diesel engine, the regulation of the force exerted by the spring on the shut-off element from the pressure of the fuel leakage ensures that the pressure at the beginning and end of injection depends on the speed and load conditions of the diesel engine. However, the system has a simpler design by eliminating an external pressure source and using one type of fluid.

Claims (2)

 1. A system for supplying fuel to a diesel engine, comprising a high pressure pump, a fuel pipe, an injector with a locking member, a spring, a movable element made in the form of a piston located in a hydraulic chamber, characterized in that the nozzle has a connecting channel communicating with the hydraulic chamber with ring groove on the spray guide.  2. The system according to p. 1, characterized in that the annular groove is made on the guide of the locking body.

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