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
  • F02M37/00—Apparatus or systems for feeding liquid fuel from storage containers to carburettors or fuel-injection apparatus; Arrangements for purifying liquid fuel specially adapted for, or arranged on, internal-combustion engines
  • F02M37/0047—Layout or arrangement of systems for feeding fuel
• • 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
  • F02M39/00—Arrangements of fuel-injection apparatus with respect to engines; Pump drives adapted to such arrangements
  • F02M39/02—Arrangements of fuel-injection apparatus to facilitate the driving of pumps; Arrangements of fuel-injection pumps; Pump drives
• • 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
  • F02M59/00—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps
  • F02M59/44—Details, components parts, or accessories not provided for in, or of interest apart from, the apparatus of groups F02M59/02 - F02M59/42; Pumps having transducers, e.g. to measure displacement of pump rack or piston
• • 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
  • F02M63/0001—Fuel-injection apparatus with specially arranged lubricating system, e.g. by fuel oil
• • 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
  • F02M59/00—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps
  • F02M59/02—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps of reciprocating-piston or reciprocating-cylinder type
  • F02M59/04—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps of reciprocating-piston or reciprocating-cylinder type characterised by special arrangement of cylinders with respect to piston-driving shaft, e.g. arranged parallel to that shaft or swash-plate type pumps
  • F02M59/06—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps of reciprocating-piston or reciprocating-cylinder type characterised by special arrangement of cylinders with respect to piston-driving shaft, e.g. arranged parallel to that shaft or swash-plate type pumps with cylinders arranged radially to driving shaft, e.g. in V or star arrangement
• • 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

Definitions

• the present invention relates to a pump unit for a fuel injection system of an internal combustion engine.
• the present invention relates to a pump unit for a fuel injection system of an internal combustion engine, in which the pump unit is arranged along the fuel feed circuit and comprises a high-pressure pump and a pump for pre-feeding the high-pressure pump.
• the high-pressure pump comprises a pump body and a flange joined to the pump body.
• the feed circuit comprises a feed branch and a delivery branch of the pre- feed pump, a fuel tank and a fuel filter.
• the feed branch connects a tank to the pre-feed pump, while the delivery branch connects the pre-feed pump to the high-pressure pump.
• the fuel filter is arranged along the feed branch or along the delivery branch.
• the feed circuit comprises a bypass branch which directly connects the feed branch and the delivery branch so as to bypass the pre-feed pump, and an overpressure valve which is arranged along the bypass circuit so as to allow discharge into the feed branch of any overpressure prevailing along the delivery branch so as to avoid damaging the fuel filter.
• the pre-feed pump does not require the bypass circuit and the associated overpressure valve.
• the delivery branch, the feed branch and the bypass branch, where present, are formed at least partly inside the pre-feed pump.
• each pre-feed pump model with given delivery characteristics must be manufactured with at least two variants in order to meet the requirements of the various car manufacturing companies.
• the object of the present invention is to provide a pump unit of the type described above able to overcome the drawbacks of the prior art.
• a pump unit for a fuel injection system of an internal combustion engine in which the pump unit is arranged along the fuel feed circuit and comprises a pre-feed pump and a high-pressure pump which comprises a pump body and a flange joined to the pump body, the feed circuit comprising a feed branch and a delivery branch of the pre-feed pump, the pump unit being characterized in that the feed branch and the delivery branch of the pre-feed pump are formed, at least partly, in the flange of the high-pressure pump.
• the various variants of the feed circuit may be formed in the flange which, in the case in question, is a less complex component of the pre-feed pump and may be easily produced with different variants for each model of the pump unit, thereby greatly reducing the disadvantages of the prior art.
• FIG. 1 is a schematic view, with parts removed for the sake of clarity, of a fuel injection system for an internal combustion engine, comprising a pump unit designed according to the present invention
• FIG. 2 is a side elevation view, with parts removed for the sake of clarity and on a larger scale, of a detail of the pre-feed pump according to Figure 1.
• FIG 1, 1 denotes generally in its entirety a fuel injection system of an internal combustion engine.
• the injection system 1 comprises a circuit 2 for feeding the fuel to an internal combustion engine (not shown in the accompanying figures) and a pump unit 3 comprising a pre-feed pump 4 and a high-pressure pump 5 for feeding a common rail (not shown in the accompanying figures).
• the injection system 1 comprises in succession a tank 6, a pre-filter 7 for separating the water from the intake fuel, the pre-feed pump 4 and the high- pressure pump 5, and a fuel filter 8.
• the circuit 2 comprises a feed branch 9 which connects the tank 6 to the pre- feed pump 4 and a delivery branch 10 which connects the pre-feed pump 4 to the high-pressure pump 5.
• the pre-filter 7 is arranged along the intake branch 9 between the tank 6 and the pre-feed pump 4, while the filter 8 is arranged along the delivery branch 10.
• the circuit 2 comprises a high-pressure delivery branch 11 which connects the high-pressure pump 5 to the common rail (not shown in the accompanying figures) and a choke 12 arranged along the feed branch 9 downstream of the pre-filter 7.
• the feed branch 9 can be connected to a manual pump 13 which has the function of filling the circuit 2 of the injection system 1 with fuel without starting the pre-feed pump 4 and the high-pressure pump 5.
• the pre-feed pump 4 comprises a pump body 14 and a pumping station 15 housed inside the pump body 14.
• the high-pressure pump 5 comprises a pump body 16, a pumping station 17 housed inside the pump body 16, a flange 18 joined to the pump body 16 and a shaft 19 which is schematically indicated by means of a dot-dash line and has the function of operating the pumping station 17 and the pumping station 15.
• the pump body 14 is joined to the pump body 16 on the opposite side of the flange 18.
• the circuit 2 comprises a bypass branch 20 which comprises two parallel branches 21 and 22 arranged in parallel and connects the feed branch 9 to the delivery branch 10 and is arranged in the flange 18 in parallel with the pumping station 15, an overpressure valve 23 arranged along the branch 21, and a bypass valve 24 arranged along the branch 22 in parallel with the overpressure valve 23 and the pumping station 15.
• the overpressure valve 23 is calibrated so as to discharge, along the feed branch 9, the excess fuel pumped by the pre-feed pump 4, namely when the fuel pressure in the delivery branch 10 exceeds a given value, for example a value in the region of 10 bar.
• the bypass valve 24 is calibrated so as to bypass the pumping station 15 when the fuel pressure in the delivery branch 9 assumes a given value during preparation of the injection system 1 for initial use. In fact, before starting a newly constructed internal combustion engine, it is necessary to ensure that all the parts of the internal combustion engine including the component parts of the injection system 1 are filled with fuel, which also has the function of lubricating those parts which, during use, perform an alternating movement.
• the feed branch 9 is fed by the manual pump 13 which has the function of filling the circuit 2 of the injection system 1 without starting the pre-feed pump 4 and the high-pressure pump 5.
• part of the feed branch 9, part of the delivery branch 10 and the whole of the bypass branch 20 including the overpressure valve 23 and the bypass valve 24 are arranged in the pump unit 3.
• the feed branch 9 and the delivery branch 10 extend along the whole of the pump unit 3 and pass through the flange 18, the pump body 16 and the pump body 14.
• the delivery branch 10 after passing through the filter 8, again passes through the flange 18 and the pump body 16 so as to feed the high-pressure pump 5, in particular the pumping station 17.
• the flange 18 comprises a friction bearing designed to support rotatably the shaft 19 (not shown in Figure 2), a connector 25 comprising the choke 12 and suitable for connecting the portion of the feed branch 9 outside the flange 18, a connector 26 and a connector 27 for connecting the portion of the delivery branch 10 outside the flange 18.
• the feed branch 9 extends partly inside the flange 18 along a hole 28 parallel to the plane of the sheet in Figure 2 and a hole 29 perpendicular to the plane of the sheet in Figure 2.
• the delivery branch 10 extends partly inside the flange 18 as far as the connector 26 along a hole 30 parallel to the plane of the sheet in Figure 2 and along a hole 31 perpendicular to the plane of the sheet in Figure 2.
• the holes 30 and 31 are arranged in the vicinity of the connector 26.
• the delivery branch 10 extends partly inside the flange 18 as far as the connector 27 along a hole 32 perpendicular to the plane of the sheet in Figure 2.
• the bypass branch 20 extends entirely inside the flange 18 along holes 33, 34, 35, 36 and 37 which are parallel to the plane of the sheet in Figure 2.
• the hole 28 of the feed branch 9 intersects the hole 33, which intersects the hole 34, which intersect the holes 35 and 36, which in turn intersect the hole 37, which intersects the hole 30 of the delivery branch 10.
• the holes 35 and 36 house, respectively, the overpressure valve 23 and the bypass valve 24.
• the overpressure valve 23 and the bypass valve 24 are similar and each comprise a shutter 38, a spring 39, a ring 40 provided with a frustoconical seat for supporting the shutter 38, and a ring 41 for supporting the spring 39.
• the bypass valve 24 is an overpressure valve mounted in the opposite direction to the overpressure valve 23.
• the holes 28, 30, 33, 34, 35, 36 and 37 are formed by means of drill bits used to bore through lateral surfaces 42 and 43 of the flange 18 and are closed on these lateral surfaces 42 and 43 by means of plugs (not shown in the accompanying figures).
• the flange 18 has holes 44 perpendicular to the plane of the sheet in Figure
• the overpressure valve 23 and the bypass valve 24 may be arranged in the flange 18 in accordance with the requirements of car manufacturing companies and therefore result in a reduction in the number of variants of the pre-feed pump 4.
• the high-pressure pump unit described here may be subject to modifications and variations without departing from the scope of the accompanying claims.
• the pump unit 1 may be defined solely by the pump body 16 of the high-pressure pump 5 and by the flange 18, while the pre-feed pump 4 is connected to the high-pressure pump 5 by external pipes.

Landscapes

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

Applications Claiming Priority (2)

Publications (1)

Family

ID=40313882

Family Applications (1)

Country Status (2)

Cited By (1)

• 2007
  • 2007-10-26 IT ITMI20072073 patent/ITMI20072073A1/it unknown
• 2008
  • 2008-10-21 WO PCT/EP2008/064173 patent/WO2009053345A2/en active Application Filing

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