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
  • 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
  • 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
• • 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
  • F02M2200/30—Fuel-injection apparatus having mechanical parts, the movement of which is damped
  • F02M2200/306—Fuel-injection apparatus having mechanical parts, the movement of which is damped using mechanical means
• • 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

Definitions

• the present invention relates to a pressure vibration dampener for an internal combustion engine fuel injection system as described in the preamble of claim 1.
• Publication US 5934251 discloses a solution in which there is an attempt to affect the dampening while the engine is running.
• the solution comprises an dampening diaphragm limiting the fuel volume and an adjustment diaphragm, behind which the underpressure of the inlet system of the engine affects, and springs between the diaphragms and on the inlet side of the adjustment diaphragm.
• the underpressure of the inlet side of the engine pulls the adjustment diaphragm so that the pressure on the spring between the diaphragms is reduced and thereby also the dampening diaphragm is moved and the pressure of fuel is reduced and further the fuel injection to the common rail is started due to the reduced pressure.
• this has the effect that it will improve the efficiency of the dampening of the vibration.
• the operation is, however, dependent on the underpressure of the inlet side of the engine and the effect of the vibration dampening changes only momentarily as the underpressure changes.
• Pressure vibrations are formed also on the low pressure side of conventional, pressure controlled fuel injection systems, the uncontrolled vibrations having a negative effect on the operation of the system.
• the aim of the invention is to accomplish a pressure vibration dampener for the fuel injection system of an internal combustion engine by means of which a more efficient dampening than that of prior art can be achieved and by means of which especially vibrations having different frequencies can be simultaneously dampened.
• spring rate is the ratio of the compression force in the spring unit to the spring compression travel. Spring rate can be determined with each spring compression travel of the spring unit.
• the pressure vibration dampener for the fuel injection system of an internal combustion engine comprises a body part delimiting a volume inside it.
• an intermediate piece has been movably arranged inside the volume of the body part.
• the body part further comprises a first opening, through which the volume can be connected to the fuel injection system, the first opening being arranged to open into the volume on the first side of the intermediate piece, and a spring arrangement arranged into the volume on the other side of the intermediate piece, the other side being on the opposite side of the first side in relation to the intermediate piece, one end of the spring arrangement being supported on the intermediate piece and the other end on the body part.
• a characterizing feature of the invention is that the spring rate of the spring arrangement decreases as the compression travel of the spring arrangement increases.
• the pressure vibration dampener of a fuel injection arrangement has at least two separate spring units having different spring properties, i.e. spring rate.
• spring rate the same vibration dampener can be used for reducing two vibrations occurring at different frequencies and strengths.
• the spring rate of the spring arrangement can be dimensioned so that it is continuously reduced as the compression travel increases.
• an increasing force causes an accelerating movement of the intermediate piece and thus also an efficient spring vibration dampening.
• the intermediate piece is formed by a piston unit the movement of which in the volume can be controlled by means of the parallel surfaces of the volume and the piston unit.
• the piston unit is provided with a sealing arrangement arranged on the circumference of the piston unit.
• the sealing arrangement comprises a piston ring or piston rings causing a friction force acting against the movement of the piston unit as the piston moves. This can also be used for influencing the vibration dampening properties of the system.
• the body part of the fuel pressure vibration dampener comprises a second opening that opens into the volume on the other side of the piston unit for discharging the fuel that has ended up there from the volume on the other side of the piston unit.
• FIG. 1 illustrates a part of the fuel injection system of an internal combustion engine having pressure vibration dampeners according to the invention
• - figure 4 illustrates another embodiment of a pressure vibration dampener according to the invention
• - figure 5 illustrates yet another embodiment of a pressure vibration dampener according to the invention
• FIG. 6 illustrates the relative spring rates of the spring arrangement as a function of its relative movement.
• FIG. 1 schematically illustrates a part of the fuel injection system 1 of the internal combustion engine 5.
• the internal combustion engine 5 is shown here very schematically for clarity, and it is an engine known as such.
• Fuel is fed from the fuel tank 2 by means of a fuel pump 3 at relatively low pressure via fuel piping 4 to each injection pump 6.
• the fuel piping comprises a main line 4 and branch lines 7 from the main line to each injection pump.
• Each injection pump 6 is connected to an injector nozzle 9.
• the injection pump 6 accomplishes fuel injection together with the injector nozzles 9.
• the injection pump increases the pressure to such a level that a necessary injection pressure is achieved at injector nozzles 9.
• a pressure vibration dampener 10 has been arranged in certain positions of the fuel injection system 1.
• the pressure vibration dampener has firstly been located in the ends of the main line 4 prior to the branch channels 7 leading to the injection pumps 6 as well as to the branch channels themselves.
• the pressure vibration dampener 10 can also be arranged in connection with the injection pumps 6 for dampening the pressure vibrations of both the inlet and return sides.
• a vibration dampener has been arranged in the return channels 8.
• Each fuel pressure vibration dampener has an outlet channel 11 arranged in connection therewith for discharging leak fuel away from the vibration dampeners.
• FIG. 2 illustrates in more detail an embodiment of a fuel pressure vibration dampener 10 according to the invention.
• the fuel pressure vibration dampener comprises a body part 101.
• a volume 102 has been arranged inside the body part, the volume being cylindrical, and a first opening 104 via which the volume can be connected to the fuel injection system, for example the main line 4 shown in figure 1 , the pressure vibrations of which the vibration dampener has been arranged to dampen.
• a piston unit 103 also cylindrical, has been arranged inside the volume, the piston unit acting as an intermediate piece in the volume.
• the piston unit can reciprocate in the volume in the direction of the longitudinal axis.
• the piston unit 103 comprises a indentation parallel with the longitudinal axis, such as a bore 105, being preferably located in the direction of the longitudinal axis, in the center of the piston unit.
• a structure helps centering the piston unit 103 in the volume; it additionally forms a volume for discharging the pressure pulse.
• the piston unit is additionally provided with piston rings or other sealing arrangement 106.
• the sealing arrangement i.e. here the piston rings, are chosen so that the clearance between the wall of the volume and the piston rings is relatively small. The clearance is so small that as the piston rings move, a distinct friction force is formed, dampening the movement of the piston. This can be utilised as a dimensioning parameter of the system.
• Spring arrangement 107 is arranged on the other side of the piston unit in the volume 102. One end of the spring arrangement is supported by the piston unit and the other end of the spring arrangement is supported by the body part 101.
• the spring arrangement of the pressure vibration dampener 10 of the fuel injection system 1 comprises here four spring units 108 having a spring rate that is smaller when the spring is under a certain compression than when it is in its free state. This accomplishes a very fast but a short-stroke movement of the piston unit, eliminating the pressure pulse when a pressure pulse acts on the first side of the piston unit.
• the action described above can be accomplished for example by means of a Belleville spring.
• the Belleville spring 108 is especially suitable for use in a vibration dampener according to the invention, as, for example, its compression travel is relatively small, even though the force needed for achieving the travel can be relatively large.
• the Belleville springs are arranged in relation to each other so that in their free state the outer circumferences 108' of two adjacent Belleville springs 108 are against each other and on the other hand so that the inner circumferences 108" are also against each other.
• the maximum spring force is the same that of only one spring unit, but the maximum compression travel, i.e. amount of springing, is with four Belleville springs thus arranged quadruple in comparison to that of only one spring. This applies in the case all the springs are similar.
• the operation can be widely modified by choosing for the system spring units having suitable properties.
• Figure 3 shows an dampener otherwise corresponding to that illustrated in figure 2 but here the spring arrangement comprises, as the spring unit closest to the piston, a Belleville spring differing from the others, with the spring having a smaller spring rate whereby it has in figure 3 also accomplished its compression travel while others have not. This allows the vibration dampener to dampen a vibration of both low and high intensity.
• the body part of the pressure vibration dampener 101 additionally comprises an opening 109 that opens into volume 102 on the other side of the piston unit, i.e. on the side of the piston unit where the spring unit is arranged to, through which opening the fuel leaked past the piston unit can be discharged from the volume 102, for example via discharge channels 11. Due to this, the second side of the spring unit is in essentially lower pressure than the other side and the fuel leaked past the piston unit does not disturb the operation of the dampener.
• Figure 4 illustrates another embodiment of a pressure vibration dampener 10 for a fuel injection system 1 according to the invention.
• This embodiment also corresponds with that of figure 2 in other aspects, but here the spring arrangement 107 comprises the spring units 108 located closest to the piston unit formed as pairs of two units, the pairs being arranged against each other in a way similar to that shown in figure 2. If all spring units are similar, this solution achieves a compression travel of about three fourths of the compression travel of the embodiment of figure 2, of which about one third happens at the maximum force of a single spring unit (the lowest spring unit in the figure) and two thirds with a force being double to the maximum force of a single spring unit.
• Figure 5 illustrates a vibration dampener differing from others in that one spring unit of the spring arrangement 107 is a helical spring 110.
• This kind of a spring arrangement offers the advantages of the invention to some degree, even though the space requirement can be larger, or a smaller compression travel can be arranged into a similar volume 102 than by using Belleville springs only.
• the vibration dampener of figure 5 is not provided with piston rings, either, whereby the amount fuel leaking past the piston unit is slightly larger than in, for example, the solution illustrated in figure 2.
• Figure 6 illustrates the relative spring rates of a spring arrangement as a function of its relative movement.
• the vertical axis describes the relation between force at a certain compression travel and the force at the maximum compression travel and the horizontal axis shows the relation between a certain compression travel and maximum compression travel.
• Graph 6.1 illustrates a spring arrangement in which the spring rate is reduced as the compression travel increases but so that at maximum compression travel the force is at a maximum as well.
• Graph 6.2 illustrates a spring arrangement in which the spring rate is reduced, with the increase of compression travel, to the extent that at maximum compression travel the spring force is smaller than with a relative compression travel value of 0.8.
• the compression travel 0.8-1.0 takes place with a decreasing force after the compression travel has reached a relative value of 0.8.
• Spring arrangements shown in fig. 6 can be used in the connection with the invention.

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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)
• Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=33306128

Family Applications (1)

Country Status (7)

Cited By (1)

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Citations (7)

Family Cites Families (1)

• 2004
  • 2004-10-29 FI FI20045410A patent/FI119445B/fi not_active IP Right Cessation
• 2005
  • 2005-10-26 CN CN2005800452737A patent/CN101094982B/zh active Active
  • 2005-10-26 KR KR1020077011984A patent/KR101132026B1/ko active IP Right Grant
  • 2005-10-26 EP EP05799433A patent/EP1805411B1/en active Active
  • 2005-10-26 AT AT05799433T patent/ATE398236T1/de not_active IP Right Cessation
  • 2005-10-26 WO PCT/FI2005/050378 patent/WO2006045902A1/en active IP Right Grant
  • 2005-10-26 DE DE602005007512T patent/DE602005007512D1/de active Active

Patent Citations (7)

Non-Patent Citations (1)

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