Fuel high-pressure pump

Abstract

Fuel high-pressure pump (10) for a fuel system of an internal combustion engine, the fuel high-pressure pump (10) having a pump housing (12) with a pump body (12a) and a pump cover (12b) which is fitted on the pump body (41), the fuel high-pressure pump (10) having a delivery chamber (16) which is arranged in the pump body (12a) and is delimited by a movable pump piston (18), the fuel high-pressure pump (10) having an inlet valve (14) which opens from a low-pressure region (71) of the fuel pump (10) towards the delivery chamber (16), the fuel high-pressure pump (10) having an outlet valve (20) which opens away from the delivery chamber (16) in the direction of an outlet (34) of the fuel high-pressure pump (10), a damping chamber (72) belonging to the low-pressure region (71) being configured between the pump body (12a) and the pump cover (12b), a damping pot (30a) being arranged in the damping chamber, the damping pot (30a) being formed by two metal diaphragms (73) which are welded to one another at their edges, characterized in that the damping pot (30a) is clamped against the pump cover (12b) on the one hand and against the pump body (12a) on the other hand by at least two holding ring springs (30b, 30c) which are identical in structure to one another.

Description

Technical Field

[0001] This invention relates to a high-pressure fuel pump for a fuel system of an internal combustion engine. Background Technology

[0002] This invention is based on a high-pressure fuel pump having a pump housing in which a pressure damper is arranged, as known from WO2018054628 A1. In known high-pressure fuel pumps, the pressure damper is fixed between the pump body and the pump cover by two generally annular members. Summary of the Invention

[0003] This invention is based on the need to simplify known devices and their manufacture in a practical manner. According to the invention, for this purpose, the damping tank is clamped against the pump cover on one side and against the pump body on the other by at least two retaining ring springs of identical structure.

[0004] Because the retaining ring springs are structurally identical, the number of dissimilar components is significantly reduced compared to existing technologies. These retaining ring springs act as pressure dampers, or rather, clamp the damping tank against both the pump cover and the pump body. This results in a corresponding simplification in pump manufacturing, particularly through simplified handling and logistics.

[0005] Currently, the "holding ring spring" is understood in particular as a structure having at least a substantially annular configuration, which holds a damping can formed by two metal diaphragms welded together at their edges against the pump cover on one side and against the pump body on the other side, and can also be clamped in the axial direction due to its inherent certain spring action.

[0006] Advantageously, it is possible to configure the retaining ring spring to also have elasticity or spring action in the radial direction, which, by means of the elasticity or spring action, can be clamped in the pump body or pump cover, and thus can be pre-assembled, for example, during the manufacture of the fuel high-pressure pump, before the final completion of the fuel high-pressure pump.

[0007] This can be achieved, for example, by having the retaining ring spring open at a position along its periphery, such as within a circumferential angle of 5° or 10°.

[0008] The axial elastic energy of the retaining ring spring is generated as follows: each retaining ring spring has a profile in its radial cross-section consisting of a rounded connecting section and two legs extending from the connecting section in the same radial direction. By applying an axial force to the area of ​​the legs, the legs can move toward each other, thereby causing the retaining ring spring to rebound in the axial direction.

[0009] Preferably, the rounded connecting section is arranged radially outward on the retaining ring spring and abuts against the pump body or pump cover in the radial direction. This ensures that the retaining ring spring rests facetably against the pump body or pump cover, and that the required radial force acts reliably and reproducibly between the retaining ring spring and the pump cover or pump body.

[0010] Therefore, it is specifically designed that the extended legs are arranged radially inward within the rounded connecting section. In an extended configuration, each of the legs can have a first section and a second section, wherein the first section is arranged between the second section and the connecting section. Here, viewed from the connecting section, the two first sections of the retaining ring spring can be arranged radially inward and on opposite axial sides. Advantageously, the two first sections can be tapered. Here, the structural height of the retaining ring spring, or the potential spring travel, increases continuously inward within the region of the first section.

[0011] Because the two second sections of a retaining ring spring are located in mutually parallel planes when no force is applied to the retaining ring spring, and / or, because the two second sections point towards each other axially with their radially inward ends when the retaining ring spring clamps the damping canister, a rounded abutment section is constructed between the first and second sections of the leg, which is arranged opposite the first and second sections axially when viewed from the connecting section. In particular, the retaining ring spring abuts against the axially adjacent member through this abutment section. For example, it is possible for two retaining ring springs to be placed on the edge of the metal diaphragm of the damping canister with corresponding abutment sections, and / or for a retaining ring spring facing the pump body to be placed on the pump body with its abutment section facing the pump body. In this way, a planar and reproducible abutment is achieved between adjacent members.

[0012] It is also possible to configure the fuel pump to have more than two identical retaining ring springs. For example, it is already possible to arrange two or more retaining ring springs between the damping tank and the pump cover. These retaining ring springs are preferably also abutting against each other via their abutting sections.

[0013] Similarly, two or more retaining ring springs can be arranged in the damping tank and pump housing. Likewise, these retaining ring springs are preferably abutted against each other via their abutting sections.

[0014] Such variations are particularly preferred for pump covers that are relatively high and / or have, for example, a fuel connection on their radially outer side.

[0015] A particularly advantageous feature is that the retaining ring spring, arranged toward the pump cover, rests against the pump cover, especially in a face-like manner, on the first section of the leg that points toward the pump cover. In this way, a reliable and reproducible abutment is achieved.

[0016] Preferred configuration: The retaining ring spring has a through hole passing through the first section. In this way, the entire damping chamber can be circulated, or pressure balance can be achieved unrestricted throughout the damping chamber.

[0017] Advantageously, each retaining ring spring is substantially rotationally symmetrical about its longitudinal axis.

[0018] "Essentially rotationally symmetric" specifically means that the retaining ring spring can also be open at a position along its periphery, and in particular, it should not be excluded that the retaining ring spring can have a through hole through the first section, which is a rotationally symmetric interruption in a strictly mathematical sense.

[0019] This results in the advantage that the retaining ring, when assembled in a high-pressure fuel pump, does not need to be oriented about its orientation around the longitudinal axis.

[0020] Advantageously, each retaining ring spring is substantially mirror-symmetric about a plane perpendicular to its longitudinal axis.

[0021] Here, "basically mirror symmetry" specifically includes minor breaks in symmetry, such as due to different or offset arrangements of through holes.

[0022] This produces the advantage that the retaining ring is not incorrectly assembled in terms of its orientation in the axial direction. Attached Figure Description

[0023] Exemplary embodiments of the present invention will now be explained with reference to the accompanying drawings. The drawings show:

[0024] Figure 1 The high-pressure fuel pump, which is known in the overall view;

[0025] Figure 2 A partial view according to a first embodiment of a fuel high-pressure pump modified according to the present invention;

[0026] Figure 3 From Figure 2 A magnified partial view;

[0027] Figure 4 A partial view of a second embodiment of a fuel high-pressure pump modified according to the present invention. Detailed Implementation

[0028] exist Figure 1In the figure, the fuel high-pressure pump for an internal combustion engine (not shown in more detail) is generally referred to by reference numeral 10. The fuel high-pressure pump 10 has a generally cylindrical pump housing 12, in which or on the important components of the fuel high-pressure pump 10 are arranged. Thus, the fuel high-pressure pump 10 has an inlet / flow control valve 14, a delivery piston 18 arranged in a delivery chamber 16 and capable of reciprocating motion via a drive shaft (not shown), an outlet valve 20, and a pressure limiting valve 22.

[0029] A first channel 24 exists within the housing 12, extending coaxially with the delivery chamber 16 and the delivery piston 18, and extending from the delivery chamber 16 to a second channel 26 formed by a slot, the second channel being arranged at a 90° angle to the first channel 24, and receiving a pressure limiting valve 22 within the second channel. Figure 1 In the figure, the longitudinal axis of the pump housing 12 is generally marked with reference numeral 28, and the longitudinal axis, or longitudinal direction, of the pressure limiting valve 22 is generally marked with reference numeral 29. Figure 1 At the upper part, a pressure damper 30 is arranged in the pump housing 12 between the pump cover 12b and the pump body 12b.

[0030] During operation, the delivery piston 18 draws fuel into the delivery chamber 16 via the inlet and quantity control valve 14 during the intake stroke. During the delivery stroke, the fuel in the delivery chamber 16 is compressed and discharged via the outlet valve 20, for example, into the high-pressure zone 32, or to the fuel collection line (“rail”), where it is stored under high pressure. The high-pressure zone 32 is connected to the high-pressure fuel pump 10 via the outlet pipe 34. Here, the amount of fuel discharged during the delivery stroke is regulated by the electromagnetically operated inlet and quantity control valve 14. In the event of unacceptable overpressure in the high-pressure zone, the pressure limiting valve 22 opens, allowing fuel to flow from the high-pressure zone into the delivery chamber 16.

[0031] Figure 2 and Figure 3 Shown in Figure 1 The pump shown is a modified embodiment according to the present invention. Here, Figure 2 The upper section of the pump housing 12, namely the upper section of the pump body 12a, and the pump cover 12b fixed thereon are shown. Figure 3 Shown in enlarged diagram Figure 2 The portion marked III shows the profiles of retaining ring springs 30b and 30c in a detailed radial cross-section. Figure 3 In the middle, this shape is as follows Figure 2 When filled into the high-pressure fuel pump, it appears dark in color. In contrast, in Figure 3 In the case of retaining springs 30b and 30c, the profiles are light-colored when they are in a relaxed state without any force applied to them.

[0032] A pressure damper 30 according to the invention is arranged between the pump body 12a and the pump cover 12b. It includes a damping canister 30a and two retaining ring springs 30b and 30c that are identical in structure to each other. The damping canister is composed of two metal diaphragms 73 welded to each other along a surrounding weld 93 at their edges. The retaining ring springs clamp the damping canister 30a against the pump cover 12b on one side and against the pump body 12a on the other side.

[0033] The retaining ring springs 30b and 30c have a profile in the radial cross section, which is composed of a rounded connecting section 85 and two legs 84 and 86 extending radially inward from the connecting section.

[0034] The outriggers 84 and 86 have first sections 83 and 87 and second sections 81 and 89 respectively, wherein the first sections 83 and 87 are arranged between the second sections 81 and 89 and the connecting section 85.

[0035] In this embodiment, the two first sections 83 and 87 of the retaining ring springs 30b and 30c are arranged radially inward and on opposite axial sides above and below the connecting section 85 in the figure.

[0036] In this embodiment, the two first sections 83, 87 are tapered, such that they appear as straight sections in the cross-section shown in the figures. Through-holes 90 are provided through the first sections 83, 87, allowing flow through the damping chamber 72 generally, or enabling pressure equilibrium to be established within the damping chamber 72.

[0037] Furthermore, in this embodiment, a retaining ring spring 30b arranged toward the pump cover 12b is provided to rest against the pump cover 12b with its first section 87 facing the support leg 86 pointing toward the pump cover 12b.

[0038] In this embodiment, it is also configured that: the two second sections 81 and 89 of each retaining ring spring 30b and 30c are in a state where no force is applied to the retaining ring spring 30b and 30c ( Figure 3 The lighter-colored parts (in the image) are located in planes that are parallel to each other, especially perpendicular to the longitudinal axis 28.

[0039] By applying force downwards to the upper support leg and upwards to the lower support leg, for example, while the damping tank 30a is clamped in the high-pressure fuel pump 10 by retaining springs 30b and 30c, the support legs 84 and 86 can slightly and elastically deform toward each other, corresponding to the elasticity of the retaining springs 30b and 30c in the axial direction. Here, rounded abutment sections 82 and 88 are also constructed between the first sections 83 and 87 and the second sections 81 and 89 of the support legs 84 and 86. These abutment sections are arranged opposite the first sections 83 and 87 and the second sections 81 and 89 in the axial direction when viewed from the connecting section 85.

[0040] Two retaining ring springs 30b and 30c are placed on the edge of the metal diaphragm 73 of the damping tank 30a, particularly on the surrounding welded portion 93 at the edge of the metal diaphragm 73, with corresponding abutment sections 82 and 88.

[0041] The retaining ring springs 30b and 30c, which are arranged toward the pump body 12a, are placed on the pump body 12a with their abutment sections 82 and 88 arranged toward the pump body 12a.

[0042] Figure 4 An alternative embodiment of the invention is shown. Here, the damping tank 30a is clamped against the pump cover 12b and the pump body 12a by more than two retaining ring springs 30b, 30b', 30c, 30c', 30c" with the same structure on one side and against the pump body 12a on the other side. In this embodiment, five retaining ring springs 30b, 30b', 30c, 30c', 30c" are received in the pump cover 12b, with two retaining ring springs above the damping tank 30a and three retaining ring springs below it.

[0043] In this embodiment, the retaining ring springs 30b, 30b', 30c, 30c', 30c' are open at position 7 along their circumference, such that they are elastic in the radial direction, i.e., as in these embodiments, they can be clamped in the radial direction into the pump cover 12b or alternatively into the pump body 12a.

[0044] exist Figure 4 In this embodiment, a relatively high pump cover 12b is implemented. A fluid connection 91, for example, an inlet for fuel such as gasoline, is implemented on its radially outer surface. A filter 92 is received inside the inlet.

Claims

1. A high-pressure fuel pump (10) for a fuel system of an internal combustion engine, wherein, The fuel high-pressure pump (10) has a pump housing (12) having a pump body (12a) and a pump cover (12b) mounted on the pump body (12a). The fuel high-pressure pump (10) has a delivery chamber (16) arranged in the pump body (12a) and limited by a movable pump piston (18). The fuel high-pressure pump (10) has an inlet valve (14) that opens from the low-pressure zone (71) of the fuel high-pressure pump (10) toward the delivery chamber (16). The fuel high-pressure pump (10) has an outlet valve (20) that is located away from the delivery chamber (16) in the direction toward the outlet (34) of the fuel high-pressure pump (10). The pump body (12a) and the pump cover (12b) are connected to form a damping chamber (72) belonging to the low-pressure zone (71), in which a damping can (30a) is arranged, consisting of two metal diaphragms (73) welded to each other at their edges. The damping can (30a) is characterized by being clamped by at least two retaining ring springs (30b, 30c) of identical structure against the pump cover (12b) on one side and against the pump body (12a) on the other side, wherein the retaining ring springs (30b, 30c) are open at a position (7) along their periphery, such that the retaining ring springs (30b, 30c) are elastic in the radial direction.

2. The high-pressure fuel pump (10) according to claim 1, characterized in that, The retaining ring springs (30b, 30c) are clamped in the radial direction into the pump body (12a) or the pump cover (12b).

3. The fuel high-pressure pump (10) according to claim 1 or 2, characterized in that, Each retaining ring spring (30b, 30c) has a profile in a radial cross section consisting of a rounded connecting section (85) and two legs (84, 86) extending from the connecting section in the same radial direction, such that the retaining ring spring (30b, 30c) is elastic in the axial direction.

4. The high-pressure fuel pump (10) according to claim 3, characterized in that, The rounded connecting section (85) is arranged radially outward on the retaining ring spring (30b, 30c) and abuts against the pump body (12a) or the pump cover (12b) in the radial direction.

5. The high-pressure fuel pump (10) according to claim 3, characterized in that, The extended legs (84, 86) are arranged radially inside the rounded connecting section, wherein each of the legs (84, 86) has a first section (83, 87) and a second section (81, 89), wherein the first section (83, 87) is arranged between the second section (81, 89) and the connecting section (85), wherein, viewed from the connecting section (85), the two first sections (83, 87) of the retaining ring springs (30b, 30c) are arranged radially inside and on opposite axial sides.

6. The high-pressure fuel pump (10) according to claim 5, characterized in that, The two first sections (83, 87) are tapered.

7. The fuel high-pressure pump (10) according to claim 5 or 6, characterized in that, The two second sections (81, 89) of the retaining ring springs (30b, 30c) are located in mutually parallel planes when no force is applied to the retaining ring springs (30b, 30c).

8. The high-pressure fuel pump (10) according to claim 7, characterized in that, With the retaining ring springs (30b, 30c) clamping the damping tank (30a), the two second sections (81, 89) point towards each other in the axial direction with their radially inward ends, such that a rounded abutment section (82, 88) is constructed between the first section (83, 87) and the second section (81, 89) of the legs (84, 86), the abutment section being arranged in the axial direction opposite the first section (83, 87) and the second section (81, 89) when viewed from the connecting section (85).

9. The high-pressure fuel pump (10) according to claim 8, characterized in that, Two retaining ring springs (30b, 30c) are placed on the edge of the metal diaphragm (73) of the damping tank (30a) with corresponding abutment sections (82, 88).

10. The high-pressure fuel pump (10) according to claim 9, characterized in that, Two retaining ring springs (30b, 30c) are placed on the welded portion (93) of the metal diaphragm (73) of the damping tank (30a) with corresponding abutment sections (82, 88).

11. The fuel high-pressure pump (10) according to claim 9 or 10, characterized in that, The retaining ring springs (30b, 30c) arranged toward the pump body (12a) are placed on the pump body (12a) with their abutment sections (82, 88) arranged toward the pump body (12a).

12. The fuel high-pressure pump (10) according to claim 5 or 6, characterized in that, The retaining ring springs (30b, 30c) arranged toward the pump cover (12b) abut against the pump cover (12b) with the first section (83, 87) of the support leg (84, 86) pointing toward the pump cover (12b).

13. The high-pressure fuel pump (10) according to claim 12, characterized in that, The retaining ring springs (30b, 30c) arranged toward the pump cover (12b) rest face-to-face with the first section (83, 87) of the support leg (84, 86) pointing toward the pump cover (12b).

14. The fuel high-pressure pump (10) according to claim 5 or 6, characterized in that, The retaining ring springs (30b, 30c) have through holes (90) through the first sections (83, 87) so that the damping chamber (72) can be generally circulated.

15. The high-pressure fuel pump (10) according to claim 1 or 2, characterized in that, Each retaining ring spring (30b, 30c) is substantially rotationally symmetric about the longitudinal axis of the retaining ring spring and substantially mirror-symmetric about a plane perpendicular to the longitudinal axis of the retaining ring spring.

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