HIGH-PRESSURE PUMP

• US 20180363609A1
• Filed: 09/13/2016
• Published: 12/20/2018
• Est. Priority Date: 10/26/2015
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: LUCARELLI, Francesco, LINDEN, Dietmar Van Der, LAEPPLE, Karl-Heinz
• Granted Patent: US 10,851,749 B2
• Time in Patent Office: Days
• CPC Class Codes: F02M 59/06 with cylinders arranged radially to driving shaft, e.g. in V or star arrangement
• CPC Class Codes: F02M 59/102 Mechanical drive, e.g. tappets or cams F02M45/063 takes precedence
• CPC Class Codes: F02M 59/44 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
• CPC Class Codes: F02M 59/48 Assembling; Disassembling; Replacing
• CPC Class Codes: F02M 63/0265 Pumps feeding common rails

Abstract

The invention relates to a high-pressure pump (1), in particular for a motor vehicle, for conveying a fluid, in particular fuel, e.g. diesel fuel, comprising a drive shaft having at least one cam, at least one piston, at least one cylinder (6) for mounting the at least one cam, wherein the at least one piston is supported on the drive shaft by the at least one cam, so that a translational motion can be carried out by the at least one cam as a result of a rotary motion of the drive shaft, at least one cover cap (8), which is attached indirectly or directly to the outside of the cylinder (6), wherein one end (18) of the at least one cover cap (8) rests on a projection (16) of the remaining high-pressure pump (1) for the interlocking attachment of the end (18) of the cover cap (8) to the projection (16).

Claims

1. A high pressure pump (1) for delivering a fluid, the high pressure pump comprising

a drive shaft (2) with at least one cam (3),

at least one piston (5),

at least one cylinder (6) in which the at least one piston (5) is mounted,

the at least one piston (5) being supported on the drive shaft (2) with the at least one cam (3), with the result that a translational movement can be carried out by the at least one piston (5) on the basis of a rotational movement of the drive shaft (2), and

at least one covering cap (8) which is fastened indirectly or directly to the cylinder (6) on an outer side,

characterized in that

an end (18) of the at least one covering cap (8) lies on a projection (16) of the high pressure pump (1) in order to fasten the end (18) of the covering cap (8) to the projection (16) in a positively locking manner.

2. The high pressure pump as claimed in claim 1, characterized in that the projection (16) is configured on the high pressure pump (1) on the outer side and/or the projection (16) is configured as an undercut (42) and/or the projection (16) is configured in the radial direction (41) with regard to a longitudinal axis (17) of the cylinder (6), and the end (18) of the at least one covering cap (8) lies on an axial stop (43) of the projection (16).

3. The high pressure pump as claimed in claim 1, characterized in that the projection (16) is configured in the circumferential direction or tangential direction with regard to a longitudinal axis (17) of the cylinder (6) and/or the projection (16) is formed by a ring (44) or a nut (45) on the cylinder (6).

4. The high pressure pump as claimed in claim 1, characterized in that the at least one covering cap (8) has a substantially central opening (48).

5. The high pressure pump as claimed in claim 4, characterized in that the at least one covering cap (8) has a substantially radially configured supporting section (50) and a substantially axially configured supporting section (51).

6. The high pressure pump as claimed in claim 5, characterized in that the opening (48) is configured on the supporting section (50).

7. The high pressure pump as claimed in claim 4, characterized in that the end (18) of the at least one covering cap (8) which lies on the projection (16) of the remaining high pressure pump (1) is an edge (49) of the opening (48).

8. The high pressure pump as claimed in claim 4, characterized in that an electric plug (52) is arranged in the opening (48).

9. The high pressure pump as claimed in claim 1, characterized in that a cutout (55) for a fuel nozzle (54) is configured on the at least one covering cap (8), and/or the cylinder (6) comprises a cylinder head (14) and/or a mounting cylinder (15).

10. The high pressure pump as claimed in claim 1, characterized in that the at least one covering cap (8) lies on the high pressure pump (1) with an elastic prestressing force and/or the at least one covering cap (8) is configured at least partially from an elastic plastic, and/or the at least one covering cap (8) is configured at least partially from a material with a modulus of elasticity of less than 5, 1, or 0.2 kN/mm².

15. A high pressure injection system (36) for an internal combustion engine (39), the high pressure injection system comprising

a high pressure pump (1) as claimed in claim 1, and

a high pressure rail (30) communicating with the high pressure pump.

16. The high pressure injection system as claimed in claim 15, further comprising a prefeed pump for delivering a fuel from a fuel tank to the high pressure pump.

17. The high pressure pump as claimed in claim 1, characterized in that the projection (16) is configured in the circumferential direction or tangential direction with regard to a longitudinal axis (17) of the cylinder (6) and/or the projection (16) is formed by a ring (44) or a union nut (45) on the cylinder (6).

18. The high pressure pump as claimed in claim 1, characterized in that the at least one covering cap (8) lies on the high pressure pump (1) with an elastic prestressing force and/or the at least one covering cap (8) is configured completely from a thermoplastic elastomer, and/or the at least one covering cap (8) is configured completely from a material with a modulus of elasticity of less than 5, 1, or 0.2 kN/mm².

11. A method for producing a high pressure pump (1), the method comprising the steps:

provision of a drive shaft (2) with at least one cam (3),

provision of at least one piston (5),

provision of at least one cylinder (6) in which the at least one piston (5) is mounted,

provision of at least one covering cap (8),

assembling of the at least one drive shaft (2), the at least one piston (5) and the at least one cylinder (6), with the result that the at least one piston (5) is supported on the drive shaft (2) with the at least one cam (3), and a translational movement can be carried out by the at least one piston (5) on the basis of a rotational movement of the drive shaft (2), and

fastening of the at least one covering cap (8) indirectly or directly on the cylinder (6) on the outer side,

characterized in that

the covering cap (8) is first of all stretched elastically for fastening purposes, and an elastic recovery is subsequently carried out, with the result that an end (18) of the at least one covering cap (8) lies on the projection (16) of the remaining high pressure pump (1) on account of the elastic recovery, and the at least one covering cap (8) is fastened to the projection (16) in a positively locking manner as a result.

12. The method as claimed in claim 11, characterized in that first of all an electric plug (52) is mounted, and subsequently the at least one covering cap (8) is fastened, and/or the at least one covering cap (8) is stretched in the radial direction (41) with regard to the longitudinal axis (17) of the cylinder (6) and is recovered elastically.

13. The method as claimed in claim 11, characterized in that the at least one covering cap (8) is stretched substantially at an edge (49) of an opening (48) as the end (18) of the at least one covering cap (8), with the result that the size of the opening (48) is increased by way of the stretching, and the elastic recovery is subsequently carried out substantially at the edge (49) of the opening (48), and/or the electric plug (52) which has already been mounted is first of all guided through the opening (48) of the at least one covering cap (8), and the elastic stretching of the at least one covering cap (8) is subsequently carried out, and/or the covering cap (8) is stretched, and the covering cap (8) is subsequently fastened on the remaining high pressure pump (1) with an elastic prestress.

14. The method as claimed in claim 11, characterized in that the at least one covering cap (8) is stretched, by the covering cap (8) being pushed onto the high pressure pump (1) on the outer side in the axial direction (40), and the axial movement of the at least one covering cap (8) bringing about stretching of the at least one covering (8) on account of the outer-side geometry of the high pressure pump (1).

19. The method as claimed in claim 11, characterized in that the at least one covering cap (8) is stretched substantially at an edge (49) of an opening (48) as the end (18) of the at least one covering cap (8), with the result that the size of the opening (48) is increased by way of the stretching, and the elastic recovery is subsequently carried out substantially at the edge (49) of the opening (48), and/or the electric plug (52) which has already been mounted is first of all guided through the opening (48) of the at least one covering cap (8), and the elastic stretching of the at least one covering cap (8) is subsequently carried out, and/or an axial supporting section (51) of the covering cap is stretched in the radial direction (41), and the axial supporting section (51) is subsequently fastened on the remaining high pressure pump (1) with an elastic prestress.

20. The method as claimed in claim 11, characterized in that the at least one covering cap (8) is stretched, by the covering cap (8) being pushed onto the high pressure pump (1) on the outer side in the axial direction (40), and the axial movement of the at least one covering cap (8) bringing about radial stretching of the at least one covering (8) on account of the outer-side geometry of the high pressure pump (1).