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
  • F02M55/04—Means for damping vibrations or pressure fluctuations in injection pump inlets or outlets
• • 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
• • 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
  • F02M59/12—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps having other positive-displacement pumping elements, e.g. rotary
  • F02M59/14—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps having other positive-displacement pumping elements, e.g. rotary of elastic-wall type
• • 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
  • F02M59/445—Selection of particular materials
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B1/00—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders
  • F04B1/04—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinders in star- or fan-arrangement
  • F04B1/0404—Details or component parts
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B11/00—Equalisation of pulses, e.g. by use of air vessels; Counteracting cavitation
  • F04B11/0008—Equalisation of pulses, e.g. by use of air vessels; Counteracting cavitation using accumulators
  • F04B11/0033—Equalisation of pulses, e.g. by use of air vessels; Counteracting cavitation using accumulators with a mechanical spring
• • 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
  • F02M2200/00—Details of fuel-injection apparatus, not otherwise provided for
  • F02M2200/03—Fuel-injection apparatus having means for reducing or avoiding stress, e.g. the stress caused by mechanical force, by fluid pressure or by temperature variations
• • 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
  • F02M2200/00—Details of fuel-injection apparatus, not otherwise provided for
  • F02M2200/26—Fuel-injection apparatus with elastically deformable elements other than coil springs
• • 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
  • F02M2200/00—Details of fuel-injection apparatus, not otherwise provided for
  • F02M2200/31—Fuel-injection apparatus having hydraulic pressure fluctuations damping elements
• • 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
  • F02M2200/00—Details of fuel-injection apparatus, not otherwise provided for
  • F02M2200/31—Fuel-injection apparatus having hydraulic pressure fluctuations damping elements
  • F02M2200/315—Fuel-injection apparatus having hydraulic pressure fluctuations damping elements for damping fuel pressure fluctuations
• • 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
  • F02M2200/00—Details of fuel-injection apparatus, not otherwise provided for
  • F02M2200/90—Selection of particular materials
  • F02M2200/9015—Elastomeric or plastic materials
• • 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

Definitions

• the present invention relates to a fuel pump integrating a damper to absorb hydraulic waves propagating in the fluid.
• a fuel circuit feeding a vehicle engine comprises a lift pump that flows fuel from a low pressure tank to a high pressure fuel pump that highly pressurizes the fuel prior to flow it to injectors.
• a high pressure pump known in the art comprises a rotating camshaft cooperating with a piston that reciprocally slides within a bore in order to pressurize the fuel in a compression chamber.
• the camshaft is guided in rotation between two bushings and, in operation a back flow of low pressure fuel wets the camshaft and flows through the bushings, lubricating the surfaces, and returning to the low pressure line. Hydraulic waves propagate in said back flow and generate noise, the pulsations impacting the other components of the low pressure line, such as a filter.
• a fuel pump comprising a fixed body in which is received, between rotational guiding means, such as coaxial bushings, a camshaft cooperating with a piston slidably guided within a bore.
• the camshaft is adapted to rotate and actuates the piston to reciprocally move within the bore in order to pressurize fuel within a compression chamber.
• the camshaft is provided with an integral fluid damper so that hydraulic waves propagating in a fluid wetting the camshaft and flowing through the rotational guiding means are damped.
• the camshaft is partially hollow and the fluid damper is arranged in the hollow part.
• the camshaft is further provided with a channel extending through the wall of the camshaft and establishing a fluid communication between the external surface of the camshaft and the internal hollow part.
• the damper in camshaft of the pump is a solution that provides advantages such as to be able to be done with minimum effort and low number of parts.
• the damper comprises a deformable partition member arranged in the hollow part.
• the partition deformations enable to absorb hydraulic waves by varying the volume of a first chamber (50) wherein opens the communication channel (46).
• the partition member is arranged inside the hollow part, separating the hollow part into the first chamber and a second chamber.
• the second chamber can be open in fluid communication with the fluid flow (FR) or in another embodiment it can be closed.
• the partition member can arranged at the extremity of the hollow part, the volume of the first chamber being equal to the volume of the hollow part.
• the partition In absence of hydraulic waves, the partition, remains in a rest position and, when hydraulic waves occur, the partition deforms or displaces away from said rest position.
• the partition is a deformable elastic membrane, for instance a metal sheet.
• the damper is cylindrical and the partition is a piston slidably guided in said cylindrical shape, a spring soliciting the piston toward a rest position.
• the camshaft is a composite shaft comprising a cylindrical axle shaft over which is fixedly press fitted a cam.
• Figure 1 is a sketch of a fuel circuit of a vehicle.
• Figure 2 is a cross section of a fuel pump according to a first embodiment of the invention.
• Figure 3 is a cross section of a fuel pump according to another embodiment of the invention.
• Figure 4 is an alternative to the first embodiment of figure 2.
• FIG. 1 is a non- limiting sketchy representation of a vehicle 8 having an engine 10 in which is arranged simplified fuel equipment 12. This is not limited to any specific type of vehicle, or of fuel, and the teachings of the invention are applicable to diesel as well as to gasoline or any other fuel.
• a fuel tank 14 and a low pressure pump 16 In the rear of the vehicle 8 are arranged a fuel tank 14 and a low pressure pump 16 and, in the front, on the vehicle engine 10, are arranged a high pressure pump 18, a manifold 20, also known as a common-rail, distributing high pressure fuel to a plurality of injectors 22.
• a manifold 20 also known as a common-rail, distributing high pressure fuel to a plurality of injectors 22.
• a low pressure supply line 24 extending from the tank 14 to the high pressure pump 18, a high pressure circuit 26 confined between the high pressure pump 18, the manifold 20 and the injectors 22 and, a return low pressure line 28 extending from the front to the rear of the vehicle 8 to flow some fuel back from the injectors 22 back to the tank 14.
• Both supply and return low pressure lines 24, 28, are long extending between the front and the rear of the vehicle 10 and, inside said lines, low pressure fuel flows and propagate hydraulic waves generated for instance by the operation of the high pressure pump , or by an injection event.
• the pump 18 comprises a fixed body 30 having a left member 32 spaced apart from a right member 34.
• each member 32, 34 is rotationally arranged a camshaft 36, extending along a first axis Al, that cooperates with a piston via a cam follower, not represented.
• each member 32, 34 is provided with a bushing 38 that are coaxially Al arranged.
• the camshaft 36 has one cam 40 arranged between the members 32, 34.
• the non-represented part of the pump 18 comprises the piston cooperating with the cam 40 to reciprocally slide along a second axis A2 within a bore wherein it pressurizes fuel in a compression chamber.
• part of the fuel creates a low pressure back flow F that wets the camshaft 36 then divides into a front back flow FF and a rear back flow FR, going through the bushings 38 lubricating the rotating surfaces. Hydraulic waves propagate in said back flows generating undesired pulsations in the low pressure return line.
• the camshaft 36 is provided with a fluid damper 42.
• the camshaft 36 is manufactured partially hollow, said hollow part 44 axially Al extending inside the camshaft 36 from approximately half the middle of the camshaft 36 to the right extremity of the camshaft 36 where it opens in the rear back flow FR.
• the blind end of the hollow cylinder 44 is between the bushings 38 and, the hollow cylinder 44 is in fluid communication with the interior of the pump 10 via a channel 46 extending from the hollow cylinder 44, in the vicinity of said blind end, to the outer surface of the camshaft 36.
• a transversal elastic membrane 48 for instance a thin sheet of metal laser welded on the shaft, which divides the hollow cylinder 44 into a first chamber 50, where are the blind end and the channel 46, and a second chamber 52 represented on the right of the membrane 48.
• the membrane 48 is normally plane in a rest position and, should it deform, its elastic properties solicit it permanently to return to said plane rest position.
• the inside of the first chamber 50 is filled with fuel.
• the hydraulic waves propagate along the back flow F enter the channel 46, get in the first chamber 50 and deform the membrane 48 varying the volume and damping the hydraulic pulsations of the flow.
• the total volume of the two chambers remains constant.
• the right extremity of the hollow cylinder 44 cylinder is open, filled with fuel and when the membrane deforms, fuel is expelled from the second chamber.
• the membrane can be arranged at the right extremity of the hollow part, as shown in figure 4, the first chamber taking all the volume of the hollow part.
• the right extremity of the hollow part may be closed, and the membrane be installed, as in figure 2, inside the hollow part.
• the second chamber 52 is then filled with air, or another gas.
• the membrane 48 deforms and slightly compresses the gas in the second chamber 52.
• the first chamber 50 is smaller than the second chamber 52, in other alternatives, the reverse can be made with the first chamber 50 being larger than the second chamber 52, said second chamber 52 being open or closed.
• FIG. 3 Another embodiment is sketched on figure 3.
• the membrane 48 has been replaced by a sliding piston 54 that is permanently solicited in a rest position by a spring 56 arranged in the second chamber 52.
• the hydraulic waves displace the piston varying the volume of the chambers 50, 52.
• the camshaft 36 can be mono-bloc, made of one piece, or can be composite, made of a cylindrical axle shaft over which is fixedly arranged, for instance by, a cam.
• An advantage of the latter construction is to utilize for the axle shaft a lower grade steel than what is used for the cam. In this case manufacturing the hollow cylinder may be easier.

Landscapes

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

Applications Claiming Priority (2)

Publications (1)

Family

ID=50239142

Family Applications (1)

Country Status (4)

Families Citing this family (3)

Citations (1)

Family Cites Families (9)

• 2014
  • 2014-01-20 GB GBGB1400864.3A patent/GB201400864D0/en not_active Ceased
  • 2014-12-03 KR KR1020167019129A patent/KR20160108350A/ko not_active Application Discontinuation
  • 2014-12-03 WO PCT/EP2014/076371 patent/WO2015106876A1/en active Application Filing
  • 2014-12-03 EP EP14805942.1A patent/EP3097304A1/de not_active Withdrawn

Patent Citations (1)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events