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
  • 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
  • F02M63/0225—Fuel-injection apparatus having a common rail feeding several injectors ; Means for varying pressure in common rails; Pumps feeding common rails
• • 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
  • F02M63/0012—Valves
  • F02M63/0031—Valves characterized by the type of valves, e.g. special valve member details, valve seat details, valve housing details
  • F02M63/005—Pressure relief valves
  • F02M63/0052—Pressure relief valves with means for adjusting the opening pressure, e.g. electrically controlled
• • 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
  • F02M63/0225—Fuel-injection apparatus having a common rail feeding several injectors ; Means for varying pressure in common rails; Pumps feeding common rails
  • F02M63/023—Means for varying pressure in common rails
  • F02M63/026—Means for reducing the pressure in common rails at power off

Definitions

• the invention relates to a pressure relief valve for fuel injection devices, in particular for fuel injection devices of internal combustion engines designed as common rail systems according to the preamble of claim 1.
• a pressure relief valve of the aforementioned type is known, for example, from DE 101 15 162 Cl.
• a needle-shaped valve element is used, which is sealingly guided with a shaft in the flow connection designed as a sliding guide and is spring-loaded in the direction of its blocking position.
• the sliding guide has a connection cross-section for the return which is overridden by the valve needle and is at a distance from the valve seat.
• the pressure relief valve shown permits the control of fuel from a fuel accumulator if the pressure in the fuel accumulator exceeds a predetermined value. In various operating states, however, it is desirable to lower the pressure in the fuel accumulator independently of a value specified by the design of the valve, which is not possible with the pressure relief valve shown.
• the invention specified in claim 1 is based on the problem, the function of the pressure relief valve. to expand, so that in certain operating states, regardless of the design of the pressure relief valve, the valve can be opened to adjust the pressure in the connected Lowering fabric furnishings to a level that can be specified as desired.
• valve element By coupling the valve element to a piston surface which can be pressurized to move the valve element into the open position, the opening of the valve can be controlled independently of the fuel pressures to be controlled in the connected fuel devices and the design of the valve.
• the advantages achieved by the invention are that the fuel system can be relieved in a simple manner. System relief is necessary, for example, if fuel storage components need to be replaced or repaired as part of maintenance. Last but not least, emergencies are also conceivable in which an immediate relief of the fuel pressure has to be carried out through an emergency relief.
• a surface of a cup-shaped piston which at the same time receives the spring that loads the valve element in the direction of its blocking position, is formed with a piston surface that can be pressurized.
• annular volume provided with a pressure connection is provided on the outside of the cup-shaped piston and is limited by an annular flange formed on the cup-shaped piston.
• the piston surface is pressurized with compressed air.
• the single figure shows a cross-sectional view of the pressure relief valve.
• the reference number 1 denotes the pressure relief valve in its entirety and 2 the housing.
• a bore 3 is provided in the housing 2, which runs coaxially onto a bore 4 which is connected to a high-pressure connection 5.
• the valve seat 6 which cooperates with a valve needle 7.
• the valve seat 6 is formed in a valve plate 7, which lies between the housing 3 and the housing part 8 containing the high-pressure connection 5.
• the valve plate 7 contains a valve cone assigned to the valve seat 6, against which the valve needle 7 abuts with its rounded end in the blocking position.
• the valve needle 7 consists of a piston-shaped component that is sealingly guided in the bore 3, whereby a connection cross-section 10 that radially opens out onto the return connection 9 is covered, which is at a distance from the valve seat 6 and can be overridden by the valve needle 7.
• the spring 11 is held between a spring plate 14 and the piston crown 13 belonging to the piston 12 under prestress.
• An adjustment screw 15, which acts on the spring plate 14, is used to adjust the desired spring force.
• the cup-shaped piston 12 is formed with a flange 16 which contains a piston surface 17 which delimits an annular volume 18 on the outside of the cup-shaped piston 12 which is connected to a compressed air connection 19.
• the spring and the area ratios are designed in a known manner so that the pressure relief valve opens when a pressure value is reached in the connected fuel devices that is above a specified maximum value.
• the nozzle needle 7 is displaced with compression of the spring 11 until the connection cross section 10 which is overdriven by the nozzle needle 7 is released and the fuel pressure in the connected fuel devices, for example a pressure accumulator for fuel, is reduced by deactivation. If a minimum limit pressure predetermined by the design of the valve is reached, the pressure limiting valve is closed again via the force of the spring 11.
• Opening and closing pressures are different because the area of the valve needle that is pressurized against the spring force is larger in the opening position that releases the flow connection than in the blocking position. In this way, undesired oscillation of the valve element in the event of slight pressure fluctuations can be prevented.
• a pressure reduction in the fuel system connected to the pressure limiting valve 1 can take place by pressurizing the ring volume 18. If the annular volume 18 is pressurized with compressed air via the compressed air connection 19, a pressure acts on the piston surface 17, which pushes the piston 12 under compression of the spring 11 in the opening direction, the valve needle 7 being carried along or being tracked by the applied fuel pressure and the passage to the connection cross section 10 releases. In this way, it is possible to react to emergency situations in any operating conditions and to bring about a pressure drop in the fuel devices via the return connection 9. In particular, the • Direction can be used to relieve the system during maintenance with the engine switched off.
• a further function is integrated in the valve according to the invention with simple constructional means, so that the application range of the pressure relief valve 1 has been expanded.

Landscapes

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

Applications Claiming Priority (2)

Publications (2)

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ID=34638188

Family Applications (1)

Country Status (4)

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Family Cites Families (4)

• 2003
  • 2003-11-24 DE DE10355124A patent/DE10355124B4/de not_active Expired - Lifetime
• 2004
  • 2004-11-19 WO PCT/EP2004/013142 patent/WO2005054663A1/fr active IP Right Grant
  • 2004-11-19 AT AT04798002T patent/ATE390556T1/de active
  • 2004-11-19 EP EP04798002A patent/EP1694958B1/fr active Active

Non-Patent Citations (1)

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