Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M55/00—Fuel-injection apparatus characterised by their fuel conduits or their venting means; Arrangements of conduits between fuel tank and pump F02M37/00
  • F02M55/02—Conduits between injection pumps and injectors, e.g. conduits between pump and common-rail or conduits between common-rail and injectors
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M63/00—Other fuel-injection apparatus having pertinent characteristics not provided for in groups F02M39/00 - F02M57/00 or F02M67/00; Details, component parts, or accessories of fuel-injection apparatus, not provided for in, or of interest apart from, the apparatus of groups F02M39/00 - F02M61/00 or F02M67/00; Combination of fuel pump with other devices, e.g. lubricating oil pump
  • F02M63/02—Fuel-injection apparatus having several injectors fed by a common pumping element, or having several pumping elements feeding a common injector; Fuel-injection apparatus having provisions for cutting-out pumps, pumping elements, or injectors; Fuel-injection apparatus having provisions for variably interconnecting pumping elements and injectors alternatively
  • F02M63/0205—Fuel-injection apparatus having several injectors fed by a common pumping element, or having several pumping elements feeding a common injector; Fuel-injection apparatus having provisions for cutting-out pumps, pumping elements, or injectors; Fuel-injection apparatus having provisions for variably interconnecting pumping elements and injectors alternatively for cutting-out pumps or injectors in case of abnormal operation of the engine or the injection apparatus, e.g. over-speed, break-down of fuel pumps or injectors ; for cutting-out pumps for stopping the engine
  • F02M63/0215—Fuel-injection apparatus having several injectors fed by a common pumping element, or having several pumping elements feeding a common injector; Fuel-injection apparatus having provisions for cutting-out pumps, pumping elements, or injectors; Fuel-injection apparatus having provisions for variably interconnecting pumping elements and injectors alternatively for cutting-out pumps or injectors in case of abnormal operation of the engine or the injection apparatus, e.g. over-speed, break-down of fuel pumps or injectors ; for cutting-out pumps for stopping the engine by draining or closing fuel conduits

Definitions

• the present invention relates to a connecting element for connecting a fuel injector of a piston engine to a fuel rail in accordance with the preamble of claim 1 .
• a fuel injector In a common rail system of a piston engine several fuel injectors are connected to a fuel rail, in which fuel is stored in a high pressure.
• the pressure in the fuel rail may be up to 3000 bar.
• the fuel injectors are typically operated electrically and comprise a valve needle for opening and closing fluid communication between the fuel rail and the cylinder. Because of the very high pressure in the fuel system, even a small damage can cause leaking of a fuel injector. Since all the fuel injectors are continuously connected to the fuel rail, a malfunction- ing fuel injector can cause constant leakage into a cylinder of the engine. The leaking fuel can cause damage in the cylinder and also leak further to the surroundings of the engine.
• An object of the present invention is to provide a connecting element which can be used for connecting a fuel injector of a piston engine to a fuel rail and to prevent leakages caused by a fuel injector failure.
• the characterizing features of the connecting element according to the invention are given in the characterizing part of claim 1 .
• the connecting element according to the invention comprises a connecting block for receiving fuel from a fuel rail, and a fuel pipe that is attached to the connecting block for supplying fuel to a fuel injector.
• the connecting block is provided with a fuel inlet for receiving fuel from the fuel rail and with a fuel outlet that is connected to the fuel pipe.
• the fuel pipe is provided with a flow fuse for preventing fuel supply to a leaking fuel injector.
• the flow fuse prevents flow to a fuel injector, where the valve needle is stuck in an open position. Damages to the cylinder and fuel leakages to the surroundings of an engine can thus be prevented. Since the flow fuse is integrated in the fuel pipe, the number of parts in the fuel injection system can be reduced. Also, less space for the fuel injection system around the cylinder heads of the engine is needed. Because the number of connections between different parts of the fuel injection system is reduced, also the risk of leakages is reduced.
• Fig. 1 shows schematically a fuel injection system of a piston engine
• Fig. 2 shows a connecting element for a fuel injection system according to an embodiment of the invention.
• FIG 1 is shown schematically a fuel injection system of a piston engine 1 .
• the engine is a large internal combustion engine, such as a main or an auxiliary engine of a ship or an engine that is used at a power plant for producing electricity.
• the fuel injection system is a common rail system, where pressurized fuel is stored in a fuel rail 4 before being introduced into fuel injectors 3.
• the engine 1 can comprise one or more additional fuel injection systems.
• the fuel injection system of figure 1 could be used for injecting liquid pilot fuel that is used for igniting gaseous fuel that is introduced into the intake system of the engine 1 .
• the engine 1 could thus be provided with an additional fuel injection system for gaseous fuel and also with an additional fuel injection system for liquid main fuel.
• the engine 1 comprises a plurality of cylinders 2. Each cylinder 2 of the engine 1 is provided with at least one fuel injector 3. Each fuel injector 3 is arranged to inject fuel into a cylinder 2 of the engine 1 .
• the fuel injection system comprises a low-pressure pump 6, which supplies fuel to a high-pressure pump 5.
• the high-pressure pump 5 supplies the fuel at a high-pressure into a fuel rail 4.
• the pressure in the fuel rail 4 is typically 700 to 3000 bar.
• all the fuel injectors 3 of the engine 1 are connected to the same fuel rail 4.
• the fuel injection system could be provided with two or more fuel rails 4, in which case only some of the fuel injectors 3 would be connected to each fuel rail 4.
• the fuel injection system could also be provided with two or more low-pressure pumps 6 and/or high-pressure pumps 5.
• one low-pressure pump 6 and one high-pressure pump 5 could be provided for each fuel rail 4 of the engine 1 , or several pumps 5, 6 could supply fuel to each fuel rail 4.
• Each fuel injector 3 is connected to the fuel rail 4 via a connecting element 10.
• the connecting element 10 is connected to the fuel rail 4 via a connecting duct 7.
• the connecting element comprises a fuel pipe 12 and a connecting block 1 1 to which the fuel pipe 12 and the connecting duct 7 are connected.
• FIG. 2 shows a connecting element 10 according to an embodiment of the invention.
• the main parts of the connecting element 10 are a connecting block 1 1 and a fuel pipe 12.
• the connecting block 1 1 is provided with a fuel inlet 13, which can be connected to the connecting duct 7 for introducing the pressur- ized fuel from the fuel rail 4 into the connecting element 10.
• the connecting block 1 1 is further provided with a fuel outlet 14, to which the fuel pipe 12 is attached.
• the fuel pipe 12 and the connecting block 1 1 are separate parts.
• the connecting block 1 1 is provided with an internal thread 19, which is engaged with an external thread 20 that is arranged at a first end of the fuel pipe 12.
• the other end of the fuel pipe 12 can be inserted into a cylinder head, where it is connected to a fuel injector 3.
• the connecting element 10 further comprises a flow fuse 15.
• a flow fuse is generally used as a safety device in fuel injection apparatuses and usually disposed between the pressure accumulator and the injection valve. The flow fuse prevents an uncontrolled fuel leakage to the combustion space of the cylinder, which may take place, by limiting the fuel flow rate.
• the flow fuse also called as a flow limiting valve, is a device that is designed to be triggered in certain predetermined conditions to prevent flow through it.
• the flow fuse 15 is used for preventing flow from the fuel rail 4 to the fuel injector 3 in the case the valve needle of the fuel injector 3 is stuck in an open position.
• the flow fuse 15 thus functions as a safety device that prevents fuel leakage through a malfunc- tioning fuel injector 3.
• the flow fuse 15 is arranged inside the fuel pipe 12.
• the fuel pipe 12 forms the body of the flow fuse 15.
• the flow fuse 15 comprises a piston 17 and a spring 16.
• the piston 17 is arranged completely inside the fuel pipe 12 and can move in the longitudinal direction of the fuel pipe 12.
• the spring 16 is arranged to push the piston 17 against a valve seat 18.
• the valve seat 18 surrounds the fuel outlet 14 of the connecting block 1 1 .
• the piston 17 keeps moving towards the fuel injector end of the fuel pipe 12 until it reaches a stopper surface 21 and closes the fluid communication between the connecting block 1 1 and the fuel injector 3.
• the pres- sure of the fuel rail 4 keeps the piston 17 in this position and prevents flow to the malfunctioning fuel injector 3. Damage to the engine 1 and leaking of the fuel to the surroundings is thus prevented.
• the piston 17 does not move the full distance against the stopper surface 21 , but the flow fuse 15 is configured so that the fuel injection is terminated before the pis- ton 17 has moved the full stroke from the initial position to the flow blocking position.
• the piston 17 has a channel (not shown) or a clearance (not shown), through which the flow is permitted for example when the piston is at half-way of the stroke but not permitted when the piston 17 is at its injector side end. Because the flow fuse 15 is integrated into the fuel pipe 12, the arrangement is space saving and reduces joints between the parts of the fuel injection system.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Fuel-Injection Apparatus (AREA)

Priority Applications (2)

Applications Claiming Priority (1)

Publications (1)

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Family Applications (1)

Country Status (2)

Citations (6)

Family Cites Families (2)

• 2014
  • 2014-05-22 WO PCT/FI2014/050396 patent/WO2015177399A1/en active Application Filing
  • 2014-05-22 EP EP14732255.6A patent/EP3146195B1/de active Active

Patent Citations (6)

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