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
  • 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
  • F02M59/10—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 the piston-drive
  • F02M59/102—Mechanical drive, e.g. tappets or cams
• • 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
  • F02M59/10—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 the piston-drive
• • 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
  • 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
• • 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
  • F04B1/0408—Pistons
• • 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
  • F04B1/0421—Cylinders

Definitions

• the present invention relates to a high-pressure pump for a fuel injection device of an internal combustion engine according to the preamble of claim 1.
• radial piston with one or more pump pistons are used, which indirectly from a drive shaft, for example via a cam or an eccentric in a
• Stroke movement are offset to perform a suction stroke, during which fuel is sucked into a pump working space of the high-pressure pump, and a pressure stroke in which the sucked fuel is compressed and output to the high-pressure accumulator of the common rail system.
• Such a radial piston pump for high-pressure fuel supply in common rail injection systems is z. B. from DE 102 21 305 A1.
• the radial piston pump has a plurality of pump elements radially arranged with respect to a drive shaft mounted in a pump housing, which are actuated by the drive shaft and each have a suction side and a high-pressure side.
• the pump elements are also connected to high pressure passages in the pump housing which each connect the high pressure side of a pump element to a high pressure port.
• Another known from the prior art high-pressure pump is in DE 10th
• the high-pressure pump being designed either as a radial or in-line piston pump can be formed.
• the high-pressure pump has a pump assembly and a drive shaft, wherein on the drive shaft of the pump assembly associated cam is provided.
• the pump assembly comprises a piston and a plunger body, wherein the piston is drivable by the cams of the drive shaft by means of the plunger body.
• the high-pressure pumps known in the prior art are designed such that in the pump working chamber a dead space volume extends around a top dead center of the pump piston, wherein a concentric relief groove is provided around the pump piston.
• a high-pressure pump for a fuel injection device of an internal combustion engine, which has at least one pump element with a pump piston, which is arranged in a pump working space and indirectly driven by the rotation of a drive shaft in a lifting movement in a substantially radial direction to a rotation axis of the drive shaft a dead space volume is eccentrically formed in the pump working space around the pump piston. Due to the eccentric design of the dead space around the pump piston around this is reduced, and thus the unwanted heat generation, the
• the pump element is formed in a cylinder head of the high-pressure pump.
• an undercut in the cylinder head is provided around a top dead center of the pump piston.
• the undercut is formed eccentrically around the pump piston.
• the pump working space is connected to a fuel discharge passage through which high-pressure fuel is discharged from the high-pressure pump.
• the eccentricity of the undercut around the pump piston is designed such that the dead space volume opposite the fuel drain channel is reduced, in particular removed.
• the "rear" dead space volume opposite the fuel drain channel or the dead space on the side facing away from the outlet is technically superfluous and detrimental to the efficiency of the high pressure generation Since the flow of fuel in the pump working space is concentrated mainly on the outflow side, the elimination of the rear dead space volume remains without major effects that could be critical to high pressure pumping or the life of the high pressure pump By reducing or completely eliminating in particular this technically redundant back dead volume, the efficiency of high pressure generation is further enhanced.
• the undercut is produced by milling.
• the undercut is produced by milling.
• the radially delivered cutter can be varied, so that for example present in a magazine milling cutters can be used for the production.
• the Position of the eccentric undercut by milling is well integrated into the production process of the high-pressure pump, since the milling process is performed in the soft tissue processing.
• a radial gap between the pump piston and a cylinder bore in the cylinder head in the region of the fuel drain channel is up to 0.6 mm, in particular between 0.35 mm and 0.5 mm.
• the gap can optionally be increased or varied depending on the geometric capacity of the high-pressure pump. This pressure increase is advantageously kept low according to the embodiment and is for example at a radial gap of 0.35 mm below 10 bar. At an operating pressure of the high-pressure pump of about 1600 bar to 2000 bar, this represents a comparatively very small pressure increase and thus an acceptable value.
• the pressure increase occurring during the delivery occurs at non-critical points of the high-pressure pump.
• the high-pressure pump is designed as a radial piston pump.
• the radial piston pump is preferably used in the diesel injection area, in particular in common rail systems. However, it can also be used in motor vehicles that do not work with diesel injection technology.
• Fig. 1A is a section through a portion of a high-pressure pump according to the prior art
• FIG. 1B is an enlarged detail of Fig. 1A;
• FIG. 2 shows a detail of a high-pressure pump according to an embodiment;
• FIG 3 shows a further detail of a high-pressure pump according to an embodiment.
• Fig. 1 is a section through a portion of a high-pressure pump 1 for a fuel injection device of an internal combustion engine according to the prior art.
• the high pressure pump 1 shown here is a radial piston pump and is used in a common rail system.
• the high pressure pump 1 comprises a housing 2, in which a rotationally driven drive shaft 3 is arranged, which is designed as a camshaft.
• the high-pressure pump 1 has at least one or more arranged in each case a cylinder head 8 pump elements 4, each with a pump piston 5, which is driven by a cam 6 of the drive shaft 3 indirectly in a lifting movement in at least approximately radial direction to a rotation axis 7 of the drive shaft 3.
• the pump piston 5 is guided in a cylinder bore 9 in a shaft portion 10 of the cylinder head 8 and slidably limited with its drive shaft 3 facing away from the end face in the cylinder bore 9 a pump working space 1 first Around the shaft portion 10 around a spring 12 is arranged.
• the pump working space 1 1 has (not shown) via a running in the housing 2 fuel inlet channel a connection with a fuel feed, for example, a feed pump.
• a fuel feed for example, a feed pump.
• an opening into the pump working chamber 1 1 inlet valve 13 is arranged.
• the pump working chamber 1 1 also has a connection extending in the cylinder head 8 fuel drain passage 14 with an outlet, which is connected for example with a high-pressure accumulator 15.
• With the high-pressure accumulator 15 one or more preferably arranged on the cylinders of the internal combustion engine injectors 16 are connected, injected by the fuel in the cylinder of the internal combustion engine becomes.
• an opening from the pump working chamber 1 1 outlet valve 17 is arranged.
• the pump element 4 is associated with a plunger assembly, via which the pump piston 5 is supported on the cam 6 of the drive shaft 3.
• the plunger assembly includes a hollow cylindrical plunger body 18 which is slidably guided in a bore 19.
• the pump piston 5 has a smaller diameter than the plunger body 18 and protrudes with its the pump working space 1 1 facing away from the end of the cylinder bore 9 and into the plunger body 18 inside.
• the pump piston 5 may have a piston foot 20 which is larger in diameter than its remaining area.
• the plunger assembly and the pump piston 5 are pressed by the prestressed spring 12 to the cam 6 of the drive shaft 3 out.
• the spring 12 is formed as the pump piston 5 surrounding and projecting into the plunger body 18 helical compression spring.
• the spring 12 is supported on the one hand on the cylinder head 8 and on the other hand on a spring plate 21.
• the spring plate 21 is connected to the pump piston 5 and is located on a side facing away from a roller shoe 22 of the annular web (not shown in detail here).
• the spring 12 thus acts on the spring plate 21 both on the pump piston 5 and on the plunger body 18 to press them as described above, against the cam 6 of the drive shaft 3.
• a cylindrical roller 23 is rotatably mounted in a cylinder-section-shaped receptacle on the cam 6 of the drive shaft 3 facing side of the roller shoe 22.
• FIG. 1B shows an enlarged section of FIG. 1A, indicated by reference numeral 24 in FIG. 1A, in the area of the pump working space 11.
• the pump working space 1 1 is in the manner described above by the pump piston 5 with its end facing away from the drive shaft 3 in the
• Cylinder bore 9 limited.
• the pump piston 5 is shown here in a position at a top dead center, wherein the direction of movement of the pump piston 5 is indicated in the cylinder bore 9 in the subsequent then caused by the rotational movement of the drive shaft 3 downward movement by the arrow 25.
• a dead space volume 27 can be seen, which also extends along the pump piston 5 around the annular undercut 28.
• the gap 29, which is present between the outer circumference of the pump piston 5 and the inner wall of Zylinderborhung 9 here is 0.23 mm.
• a rear dead volume 27 ' which is located on the side facing away from the fuel drain channel 14, technically superfluous.
• FIG. 2 shows a section of a high-pressure pump 1 according to an embodiment, wherein the dead space volume 27 is executed eccentrically around the pump piston 5.
• Reference number 30 schematically indicates the diameter D of 5 mm of a radially supplied milling cutter for producing the eccentric design of the dead space volume 27.
• the rear dead space volume 27 'shown in FIG. 1B is opposite to the fuel drain channel 14, by providing a eccentric undercut 28 has been eliminated.
• FIG. 3 shows a further detail of a high-pressure pump 1 according to an embodiment, wherein the undercut 28 is designed eccentrically around the pump piston 5.
• the undercut 28 is designed eccentrically around the pump piston 5.
• it is about the outer Circumference of the pump piston 5 around only a Totraumvolumen 27 formed between a portion of the outer periphery of the pump piston 5 and the cylinder bore, not shown here, which is on the side of the fuel drain channel (also not shown here, see Fig. 1 B).
• the double arrows marked Di, D 2 and D 3 indicate respective first, second and third diameters in the indicated directions, where Di is 6.5 mm, D 2 is 5 mm and D 3 is 7.2 mm.
• the height H of the undercut 28 in the embodiment is 8.73 mm.
• the high-pressure pump 1, in which a rear, the fuel drain passage opposite dead space volume is eliminated by providing the eccentric undercut around the pump piston around, has an improved delivery characteristics with significantly increased delivery rate.

Landscapes

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

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=43735054

Family Applications (1)

Country Status (6)

Cited By (1)

Citations (4)

Family Cites Families (2)

• 2010
  • 2010-01-21 DE DE102010001099A patent/DE102010001099A1/de not_active Withdrawn
  • 2010-12-28 CN CN2010800619308A patent/CN102713241A/zh active Pending
  • 2010-12-28 WO PCT/EP2010/070782 patent/WO2011088954A1/de active Application Filing
  • 2010-12-28 KR KR1020127019102A patent/KR20120113229A/ko not_active Application Discontinuation
  • 2010-12-28 EP EP10798126A patent/EP2526284A1/de not_active Withdrawn
  • 2010-12-28 RU RU2012135569/06A patent/RU2012135569A/ru not_active Application Discontinuation

Patent Citations (4)

Non-Patent Citations (1)

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