Kropp Martin

Bio: Kropp Martin is an academic researcher from Bosch. The author has contributed to research in topics: Fuel injection & Internal combustion engine. The author has an hindex of 2, co-authored 4 publications receiving 298 citations.

Fuel injection system

Abstract: A fuel injection system for an internal combustion engine including a fuel injector which can be subjected to fuel at high pressure and is actuatable via a metering valve device by which the pressure in a pressure booster control chamber is controllable such that the pressure in a pressure booster pressure chamber, defined by a pressure booster piston, that can be filled with fuel from the high-pressure fuel source via a filling path in which a check valve is disposed and that is in communication with an injection valve member pressure chamber, is increased by the pressure booster piston such that an injection valve member opens for injecting fuel, whereupon fuel is positively displaced out of a damping chamber via a damping path, in which a damping throttle is disposed. To assure stable injection performance, the damping path is embodied such and connected in such a way to the filling path that the fuel positively displaced from the damping chamber via the damping throttle in an injection event reaches the filling path of the pressure booster pressure chamber via the damping path.

Fuel injection method and fuel injection system for internal combustion engine

Abstract: PROBLEM TO BE SOLVED: To improve an injection characteristic and an efficiency of a fuel injection system by arranging a pressure reducing control unit for forming at least one of low fuel pressure during injecting fuel, and controlling the pressure reducing control unit through a valve unit. SOLUTION: A displacement controlling type high pressure pump 2 is disposed in a pressure controlled fuel injection system 1, fuel in a fuel tank 4 is pumped up by its operation, and it is forcibly supplied to a pressure accumulator 6 through a forcibly supplying pipe passage 5. Fuel accumulated therein is led to a distribution device 8 through a valve unit 7, and is distributed to a plurality of high pressure pipe passages 9 led to each of individual cylinders, and then, the fuel is supplied to an injector 10 disposed on a combustion chamber of an internal combustion engine. In this time, fuel is supplied into the injector 10 in such a way that high fuel pressure is depressurized to low fuel pressure through a local pressure reducing control unit 11. An associated value unit 12 is controlled by the pressure reducing unit 11, and thereby, a supplying method is switched into such a way that high fuel pressure is directly supplied to the injector 10 or low fuel pressure is supplied through an orifice 13.

Fuel injection apparatus

Abstract: Fuel injector has hydraulic damper (37) which is arranged in the control circuit (13) and an injection nozzle (3). The hydraulic damper is so formed that it displays its damping action starting from predetermined prestroke (38) of injection nozzle at the opening of injection nozzle.

Fuel injection system for internal combustion engine, has high pressure zone connected to damping chamber that receives movable damping piston that is displaced in damping chamber under effect of pressure against opposing force

Abstract: The system has a fuel injector (1) provided with a case (2) receiving a valve body (32, 34) in a sliding manner. The body has a pressure surface stressed by the pressure of the fuel in high pressure zone (22, 26) of the injector. The zone is connected to a damping chamber (40) receiving a movable damping piston (44) that is displaced in the damping chamber under the effect of pressure against an opposing force.

Variable displacement compressor

Abstract: A swash plate 20 made of an aluminum-based material is allowed to be inclined in the axial direction of a rotary shaft 18 and to rotate integrally with the rotary shaft 18 due to the engagement between guide holes 251 formed in the support arms 25 made of an iron-based material and heads 231 of to-be-guided pins 23 made of an iron-based material. The inclination of the swash plate 20 is guided based upon a slide guide relationship between the guide holes 251 and the to-be-guided pins 23 and upon a slide support action of the rotary shaft 18. The inclination-limiting protuberances 191 integrally formed on the rotary support member 19 made of the iron-based material come into contact with the to-be-guided pins 23. The swash plate 20 is inclined at a maximum angle in a state where the inclination-limiting protuberances 191 come into contact with the to-be-guided pins 23.

High pressure pump

Abstract: Between a movable core chamber and a fuel supply passage, a needle guide slidably supports a needle fixed to a movable core. The needle guide has a communication hole which fluidly connects the movable core chamber and the fuel supply passage. An opening sectional area of the communication hole is defined in such a manner that a fuel discharged amount decreases as an energization start time of a coil is delayed. In a suction stroke, it is restricted that the movable core and the needle bounce toward the fixed core after the needle biases a suction valve toward a stopper by means of a biasing force of a second spring. A relationship between the energization start time of the coil and the fuel discharged amount is properly maintained, so that the fuel discharged amount of the high-pressure pump can be controlled correctly.

Fuel-injection valve

Abstract: The invention relates to a fuel-injection valve, in particular a high-pressure injection valve for directly injecting fuel into a combustion chamber of a compressed-mixture, spark-ignition internal combustion engine. Said valve is characterised in that an outlet opening (23) is provided downstream of the valve seat (20), the downstream end of said opening having a slit-forming element (30) that to a great extent closes the outlet opening (23). A slit-type flow outlet (35), through which a fuel spray can be discharged in a fan-type jet, is formed between the slit-forming element (30) and a front face (34) of the valve seat body (16).

Gallium nitride crystal and method of making same

Abstract: There is provided a GaN single crystal at least about 2 millimeters in diameter, with a dislocation density less than about 10 4 cm −1 , and having no tilt boundaries. A method of forming a GaN single crystal is also disclosed. The method includes providing a nucleation center, a GaN source material, and a GaN solvent in a chamber. The chamber is pressurized. First and second temperature distributions are generated in the chamber such that the solvent is supersaturated in the nucleation region of the chamber. The first and second temperature distributions have different temperature gradients within the chamber.

Fuel injection device

Abstract: The invention relates to a pressure-controlled fuel-injection device (1). Said device comprises a common pressure accumulation chamber, one injector (3) per cylinder and a local pressure intensifier (4) that is allocated to each injector (3). A 2/2-way valve (14) is provided for metering fuel to the injector (3).