Classifications

• • 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
  • F04B1/0426—Arrangements for pressing the pistons against the actuated cam; Arrangements for connecting the pistons to the actuated cam
• • 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
  • F02M2200/02—Fuel-injection apparatus having means for reducing wear

Definitions

• the invention relates to a pump element for a piston pump for generating high fuel pressure in fuel injection systems of internal combustion engines according to the preamble of claim 1 and piston pumps according to the independent claim 12.
• the invention has for its object to provide a pump element and a piston pump for high-pressure fuel generation, which is simple in construction and has a further increased reliability under all operating conditions.
• a pump element for a piston pump for generating high fuel pressure in fuel injection systems of internal combustion engines with at least one piston arranged in a cylinder bore, the piston having a piston foot and a piston shaft, with a plate attached to the piston foot for transmitting the delivery movement from a drive on the piston, wherein the piston foot has a contact surface which cooperates with a recess in the plate, in that the support surface and the recess form an essentially flat contact zone.
• the flat contact zone between the support surface and the depression makes it possible to transmit the forces to be transmitted in the axial direction of the piston evenly over a large area.
• the flat contact surface can prevent the plate from performing a tilting movement which causes or enables the reciprocating movements in the tangential direction of the ring mounted on the drive shaft. It is thereby achieved that the ring performs no or only a very small rotary movement in all operating states of the high-pressure fuel pump and thus the bending stress on the plate and the piston is reduced. This is particularly important if the pump elements do not deliver the full flow, but are only partially filled by reducing the fuel flow accordingly. When the pump elements are partially filled, vapor bubbles form in the pump elements, which results in non-uniform torque transmission from the drive shaft to the pump elements.
• the configuration of the pump elements in accordance with the invention suppresses the rotary movements of the ring to such an extent that there are no more selective overstressing of the pump element or the ring. This increases the service life of the pump elements and the piston pump as a whole, without increasing the manufacturing costs.
• the contact zone is greater than or equal to the cross-sectional area of the piston skirt, so that the undesired tilting of the plate and the undesired rotational movement of the ring are further reduced.
• the contact surface of the piston foot or the surface of the recess forming the contact zone with the contact surface are curved with a radius greater than twenty times the diameter of the piston shaft , This large radius of curvature ensures that manufacturing tolerances can be compensated for without the plates tipping or the ring rotating.
• the piston foot and the plate are positively connected to one another by a plate holder, so that the plate always rests on the ring, which prevents damage to these components and facilitates the formation of a load-bearing lubricating film.
• the piston base has a collar and the plate holder is connected to the piston via the flange, so that on the one hand a large contact zone between the plate and piston base is possible and on the other hand a secure positive connection between the piston and the plate holder is ensured.
• This solution is also easy to assemble because the number of components is very small.
• the piston foot can also have a groove with an explosive ring and the plate holder can be connected to the piston via the explosive ring, so that the manufacture of the piston is further simplified.
• the plate holder is connected to the plate by shaping, in particular by flanging or folding, so that a durable, durable connection between the plate holder and plate is created in a simple and effective manner.
• the plate can have a bevel on the circumference on the side facing the piston.
• a particularly secure connection between the plate holder and plate can be achieved if the plate has a collar and the plate holder encloses the collar.
• the plate can also be connected directly to the piston, in particular by flanging or folding.
• the number of components is reduced again, which has a positive effect on the manufacturing costs.
• a piston pump for fuel generation in fuel injection systems of internal combustion engines in particular in a common rail fuel injection system, with at least one pump element, in that the at least one pump element is a pump element according to one of the preceding claims.
• the advantages according to the invention are fully apparent.
• it has proven to be advantageous to design the piston pump according to the invention as a radial piston pump according to claims 13 or 14. Further advantages and advantageous embodiments of the invention are as follows . Drawing, its description and the claims can be found.
• FIG. 1 shows a cross section through an embodiment of a high-pressure fuel pump according to the invention, designed as a radial piston pump,
• FIG. 2 is a detailed representation of the first
• Fig. 3-5 a second embodiment of a pump element according to the invention.
• Fig. 6-7 a cross section and a plan view of a third embodiment of a plate according to the invention.
• FIG. 1 shows a section through a radial piston pump equipped with pump elements 1 according to the invention for generating high-pressure fuel in injection systems of internal combustion engines.
• this radial piston pump designated as a whole by 3
• three pump elements 1 are arranged at an angle of 120 ° to one another around a drive shaft 5.
• An eccentric section of the drive shaft 5 is shown in the sectional plane of FIG. 1.
• the drive shaft 5 is rotatable in one Housing 7 of the radial piston pump 3 mounted (not shown).
• a pump element 1 consists of a cylinder bore 9 and a piston 11 which is sealingly guided in the cylinder bore 9.
• the piston 11 in turn consists of a piston shaft 13 and a piston foot 15.
• a plate 17 is fastened to the piston foot 15.
• a ring 19 with flats 21 is arranged between the eccentric section of the drive shaft 5 and the plates 17 shown in FIG. 1.
• This polygon-shaped ring 19 serves to convert the rotary movement of the eccentric section of the drive shaft 5 into an oscillating movement.
• the polygonal ring 19 oscillates once in the direction of the longitudinal axis of the pistons 11 and perpendicular to the longitudinal axis of the pistons 11.
• the polygonal ring 19 should not rotate. This creates a sliding movement between plate 17 and flattening 21. This sliding movement results in a tilting moment on plate 17.
• a groove 25 is pierced in the piston foot 15, and an explosive ring 27 is inserted in the groove 25.
• the piston foot has a substantially flat bearing surface 29 which projects into a recess 31 in the plate 17.
• the bearing surface 29 of the piston foot 15 rests on the base 33 of the depression 31. This results in an essentially flat contact zone between the contact surface 29 and the depression 31 or the base 33 of the depression 31.
• the contact zone (not designated in FIG. 2) in the first exemplary embodiment is as large as the cross section of the piston skirt 13, so that there is a very good introduction of the forces transmitted from the plate 17 to the piston skirt 15 in the axial direction of the piston skirt 13.
• the flat contact zone prevents the plate 17 from tilting relative to the piston skirt 13.
• a plate holder 35 which takes the piston shaft 13 in an opening 37.
• a force can be transmitted from the plate holder 35 in the direction of the piston foot 15 to the piston skirt 13 by the detonation ring 27.
• a compression spring 39 which is supported at one end on the pump holder 35 and at the other end on the housing 7 of the radial piston pump 3 (see FIG. 1), presses the plate holder 35 from top dead center to bottom dead center when the eccentric section of the drive shaft 5 (see FIG 1) executes the corresponding rotary movement. This movement is also transmitted to the piston skirt 13 via the detonation ring 27.
• the plate holder 35 also has a flanged edge 39 which surrounds a collar 41 of the plate 17.
• the exemplary embodiment shown in FIG. 2 is very easy to produce in terms of production technology, since the piston skirt 13 and the piston foot 15 have the same diameter and can therefore be ground in one setting.
• the plate 17 has on the bearing surface 29, which with the in Fig. 5 ring 19, not shown, comes into contact., A chamfer 40.
• the chamfer 40 has the effect that even when the polygon-shaped ring 19, which is not shown, is rotated under unfavorable circumstances, the plate holder 35 is not damaged by the resulting tilting movement of the plate 17.
• the chamfer 40 can be provided in all exemplary embodiments of the pump element 1 according to the invention.
• the piston foot 15 adjoining the piston skirt 13 has a significantly larger diameter than the piston skirt 13 in this exemplary embodiment. It is achieved in that the piston foot 15 has a collar 43. Due to the collar 43, the contact surface 29 of the piston foot 15 increases. In this exemplary embodiment, the contact surface 29 is of slightly curved design.
• FIG. 4 shows a plate 17 belonging to the piston 11 of FIG. 3.
• the recess 31 is dimensioned such that the piston foot 15 fits exactly into the recess 31.
• FIG. 5 shows the piston 11 and the plate 17 according to FIGS. 3 and 4 in the assembled state.
• the plate holder 35 transmits the force exerted on it by the spring 38 to the piston skirt 13 via the collar 43.
• the groove 25 and the detonation ring 27 can be omitted.
• FIG. 5 shows that the contact zone between piston foot 15 and plate 17 is larger than in the first exemplary embodiment.
• the surface load between the piston foot 15 and the base 33 of the recess 31 in the plate 17 is further reduced. Besides, that can Twisting of the polygonal ring 19 (see FIG. 1) can be prevented even more effectively.
• the plate holder 35 In order to center the spring 38, the plate holder 35 has first lugs 36a which are bent upwards. In alternation with the first lugs 36a, the plate holder 35 has second lugs 36b which are bent downwards. The plate 17 is fixed to the piston foot 15 by the second lugs 36b.
• the plate 17 has a chamfer 40 on the contact surface which comes into contact with the ring 19 (not shown in FIG. 5).
• the chamfer 40 has the effect that even when the polygonal ring 19, which is not shown, is rotated under unfavorable circumstances, the plate holder 35 is not damaged by the resulting tilting movement of the plate 17.
• the chamfer 40 can be provided in all exemplary embodiments of the pump element 1 according to the invention.
• a plate 17 of a third exemplary embodiment of a pump element according to the invention is shown in cross section and in plan view. No plate holder is provided in this embodiment.
• the necessary positive connection between the piston skirt 13 (not shown) and the plate 17 is made via a flanged edge 45.
• the flanged edge 45 is bent inwards and pressed into a groove in the piston 11, not shown.
• the groove and the flanged edge 45 must be dimensioned such that in any case the piston foot 15 (not shown) rests on the base 33 of the depression 31.
• recesses 47 are provided in the crimping edge 45.
• the exemplary embodiments of pump elements described above are not limited to radial piston pumps, but can also be used with in-line or distributor injection pumps.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Reciprocating Pumps (AREA)
• Fuel-Injection Apparatus (AREA)
• Details Of Reciprocating Pumps (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=7702265

Family Applications (1)

Country Status (6)

Families Citing this family (14)

Family Cites Families (17)

• 2001
  • 2001-10-15 DE DE10150351A patent/DE10150351A1/de not_active Withdrawn
• 2002
  • 2002-07-27 EP EP02760107A patent/EP1438505B1/fr not_active Expired - Lifetime
  • 2002-07-27 AT AT02760107T patent/ATE452290T1/de not_active IP Right Cessation
  • 2002-07-27 WO PCT/DE2002/002780 patent/WO2003042534A2/fr not_active Ceased
  • 2002-07-27 DE DE50214103T patent/DE50214103D1/de not_active Expired - Lifetime
  • 2002-07-27 US US10/450,175 patent/US7384246B2/en not_active Expired - Lifetime
  • 2002-07-27 JP JP2003544334A patent/JP2005509782A/ja active Pending

Non-Patent Citations (1)

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