阅读说明：本技术 具有附接接管的燃料高压泵 (High-pressure fuel pump with an attached nozzle ) 是由 S·科尔布 F·梅尔廷 于 2019-09-12 设计创作，主要内容包括：本发明涉及一种具有用于与燃料管路的附接区段连接的管状附接接管的燃料高压泵,其中,所述附接接管的外壁具有至少一个径向向内指向的凹槽,在该凹槽中布置有用于所述燃料管路的附接区段的径向向外伸出的保险器件。(The invention relates to a high-pressure fuel pump having a tubular attachment stub for connection to an attachment section of a fuel line, wherein the outer wall of the attachment stub has at least one radially inwardly directed groove in which a radially outwardly projecting securing means for the attachment section of the fuel line is arranged.)

1. A high-pressure fuel pump (22) having a tubular attachment stub (56) for connection to an attachment section (20) of a fuel line (18), characterized in that an outer wall (60) of the attachment stub (56) has at least one radially inwardly directed groove (70) in which a radially outwardly projecting securing means (78) for the attachment section (20) of the fuel line (18) is arranged.

2. The high-pressure fuel pump (22) as claimed in claim 1, wherein the groove (70) is configured completely circumferentially in the circumferential direction.

3. The high-pressure fuel pump (22) according to at least one of the preceding claims, wherein the securing means comprise a securing ring, in particular a snap ring (78).

4. The high-pressure fuel pump (22) as claimed in at least one of the preceding claims, wherein the securing means (78) is configured as an arrangement for an attachment section (20) which is configured as a quick-connect joint.

5. Fuel high-pressure pump (22) according to at least one of the preceding claims, wherein the groove (70) is provided in an intermediate region of the outer wall (60), preferably centrally, and/or,

wherein the groove (70) adjoins onto the cylindrical section (66) of the outer wall (60), preferably arranged between and adjoining two cylindrical sections (66, 68) of the outer wall (60).

6. The high-pressure fuel pump (22) according to at least one of the preceding claims, wherein the outer wall (60) has a constant wall thickness (d).

7. Fuel high-pressure pump (22) according to at least one of the preceding claims, wherein the outer wall (60) comprises at least one section (64) produced by a forming process, in particular a deep drawing process, preferably the entire outer wall (60) is produced by a forming process, in particular a deep drawing process.

8. The high-pressure fuel pump (22) according to at least one of the preceding claims, characterized in that it comprises a piston chamber (26), wherein the piston chamber (26) can be connected to a low-pressure region (28) or a high-pressure region (45) of a fuel system (10) of an internal combustion engine via the attachment stub (56) and an attachment section (20) arranged thereon.

9. The high-pressure fuel pump (22) according to at least one of the preceding claims, characterized in that it comprises a pump housing (52) and the attachment stub (56) is arranged on the pump housing (52), in particular soldered or welded to the pump housing (52).

10. Fuel high-pressure pump (22) according to at least one of the preceding claims, characterized in that it comprises a pressure damping device (29) with a cover element, and in that the attachment nipple (56) is arranged on the cover element, in particular soldered or welded thereto.

Technical Field

The invention relates to a high-pressure fuel pump according to the preamble of claim 1.

Background

Fuel systems for internal combustion engines are known from the market, in which fuel is delivered from a fuel tank at high pressure by means of a prefeed pump and a mechanically driven high-pressure fuel pump into a high-pressure accumulator ("rail") located in a high-pressure region. In the pump housing of such a high-pressure fuel pump, a piston chamber is usually arranged in which the fuel is compressed to a high pressure by a piston. The piston chamber is in fluid connection with the low-pressure region. The fluid connection usually comprises an attachment socket provided on the high-pressure fuel pump, on which an attachment section of the low-pressure line is arranged.

Disclosure of Invention

The problem on which the invention is based is solved by a high-pressure fuel pump having the features of claim 1. Advantageous embodiments are given in the dependent claims. Furthermore, the features which are relevant for the invention are given in the following description and the drawing, wherein the features are relevant for the invention both individually and in different combinations, and are not explicitly indicated here.

Therefore, a high-pressure fuel pump is initially proposed, which has a tubular attachment stub for connection to an attachment section of a fuel line. The outer wall of the attachment socket has at least one radially inwardly directed groove, in which a radially outwardly projecting securing means for the attachment section of the fuel line is arranged. Thus, the attachment section of the fuel line can be arranged on the securing means. The groove can be designed in particular as a groove.

The production of the attachment socket with the grooved outer wall can be realized relatively cost-effectively. Furthermore, the service life of the attachment stub thus produced is particularly long. The risk of an undesirably premature component failure is reduced here in particular by the fact that no or hardly any component weakening of the attachment socket is present in the region of the recess. However, the attachment section can still be reliably fixed on the attachment stub. This is achieved by arranging the fuse element in the recess. The attachment section can in turn be fixed to the securing device.

In one embodiment, the groove is formed completely circumferentially in the circumferential direction. The production of a recess configured in this way can be particularly simple, for example, by means of a forming process, in particular a deep-drawing process. Furthermore, the securing means can be arranged relatively simply on the circumferentially arranged recess.

In a further embodiment, the securing means comprises a securing ring. The securing ring can be fixed in the recess particularly easily. In this case, the securing ring cannot be completely closed, so that it can be slightly enlarged, for example, by means of pliers, in order to then position the securing ring in the recess in a form-fitting manner.

The securing ring can be designed in particular as a circular ring section and thus be rectangular in cross section. In this case, the recess can be configured in particular complementary to the securing ring, so that the securing ring can be mounted in the recess without play.

In this context, it is conceivable, in particular, for the securing ring to be a snap ring. The snap ring can be made in particular of spring steel. Furthermore, the snap ring has, in particular, end portions which are not aligned with respect to one another in the non-arranged state, so that after arrangement in the groove, the snap ring is axially clamped in the groove and is thus supported in a loss-proof manner.

Furthermore, it is conceivable that the securing means is designed for arranging an attachment section designed as a quick-connect coupling. The attachment section can therefore have, in particular, a snap lock in order to hold the attachment section on the securing device.

In this context, it is conceivable for the recess to be arranged in an intermediate region of the outer wall, preferably in the center of the outer wall.

The standard SAE J2044 relating to quick-connect joints requires a projection in the middle region of the attachment stub in order to hold the attachment section thereon. The projection is currently realized by a securing means, so that an attachment section designed as a quick-connect connection and designed according to standard SAE J2044 can be arranged on the attachment socket.

Furthermore, it can be provided in particular that the groove adjoins a cylindrical section of the outer wall of the attachment stub, preferably arranged between and adjoining two cylindrical sections of the outer wall of the attachment section. An attachment socket constructed in this way can be produced particularly simply.

The outer wall can in particular be designed in one piece. Furthermore, the outer wall can have, in particular, a constant wall thickness. In particular, it is therefore conceivable for the inner diameter of the outer wall in the region of the groove to be smaller than the inner diameter of the outer wall in the region of the adjoining cylindrical section.

In this context, it is conceivable in particular for the outer wall of the attachment socket to comprise at least one section produced by a forming process, in particular a deep drawing process. Preferably, the entire outer wall of the attachment socket is produced by a forming process, in particular a deep drawing process. The production by means of the deep-drawing process can be realized at relatively low cost. Furthermore, the attachment socket can be produced in particular with a relatively low degree of shaping. This is achieved in that only a relatively small degree of shaping is required for the formation of the recess in the deep-drawing process, so that a high strength can be provided continuously in the outer wall. The absence of a high degree of shaping, in particular at any point in the outer wall, makes it possible to achieve neither a weak point of strength which is introduced or caused by the production method, so that the durability of the attachment socket is increased and the risk of premature failure of the attachment socket is therefore reduced.

The high-pressure fuel pump may in particular have a piston chamber, wherein the piston chamber can be connected to a low-pressure region or a high-pressure region of a fuel system of the internal combustion engine via an attachment socket and an attachment section arranged thereon. Thus, in particular the low-pressure line or the high-pressure line can have an attachment section. Such a high-pressure fuel pump can be realized at relatively low cost. Furthermore, the risk of premature failure of the attachment nipple of the high-pressure fuel pump is reduced.

In this context, it is conceivable to arrange the attachment socket on the pump housing, in particular soldered or welded to the pump housing. In particular, the low-pressure region can be fluidically connected to the piston chamber, so that fuel to be delivered can pass from the low-pressure region through the attachment stub into the piston chamber.

It is also conceivable for the fuel high-pressure pump to comprise a pressure damping device with a cover element. The attachment socket can be arranged on the cover element, in particular soldered or welded to the cover element. In particular, the low-pressure region can be fluidically connected to the piston chamber, so that fuel to be delivered can pass from the low-pressure region through the attachment stub into the pressure damping device and from there into the piston chamber.

Drawings

Further features, application possibilities and advantages of the invention result from the following description of exemplary embodiments of the invention, which are illustrated on the basis of the drawings.

The figures show:

FIG. 1 is a simplified schematic illustration of a fuel system for an internal combustion engine;

fig. 2 shows a perspective view of a region of a high-pressure fuel pump according to the invention with an attachment stub having a securing means arranged thereon;

FIG. 3 is a cross-sectional view of a region of the high pressure fuel pump of FIG. 2;

FIG. 4 is a cross-sectional view as in FIG. 3, but without the safety device; and

fig. 5 is a schematic top view of the fuse element according to fig. 2.

Functionally identical elements and regions are provided with the same reference symbols in the following figures and are not explained in detail.

Detailed Description

Fig. 1 shows a fuel system 10 for an internal combustion engine, not shown in detail, in a simplified schematic representation. In operation of fuel system 10, fuel is supplied from fuel tank 12 via suction line 14 by means of pre-feed pump 16 and low-pressure line 18, which includes attachment section 20, to a high-pressure fuel pump 22, which is embodied as a piston pump.

An inlet valve 24 is arranged in the high-pressure fuel pump 22. By means of the attachment section 20 and the inlet valve 24, the piston chamber 26 can be fluidly connected with a low pressure region 28, which comprises the prefeed pump 16, the suction line 14 and the fuel tank 12. The inlet valve 24 can be opened forcibly by the operating device 30. The actuating device 30 and thus the inlet valve 24 can be actuated by a control unit 32. By the targeted opening and closing of the inlet valve 24 at specific points in time during the intake stroke of the high-pressure fuel pump 22, the fuel delivery quantity can be adjusted.

The piston 34 of the high-pressure fuel pump 22 can be moved up and down along a piston longitudinal axis 38 by means of a drive 36, which is embodied in the present case as a cam disk, as is indicated schematically by an arrow with the reference number 40. An outlet valve 44 is arranged hydraulically between the piston chamber 26 and an outlet 42 of the high-pressure fuel pump 22, which can be opened towards a high-pressure region 45 comprising a high-pressure reservoir 46 ("rail"). The high-pressure accumulator 46 and the piston chamber 26 can be fluidically connected by a pressure-limiting valve 48, which opens when a limiting pressure in the high-pressure accumulator 46 is exceeded.

Fig. 2 shows the upper part of the high-pressure fuel pump 22 in a perspective view. Here, the high-pressure fuel pump 22 first includes a pump housing 52. The attachment nipple 56 is secured in the recess 54 of the pump housing 52 (see fig. 3). The piston chamber 26 is fluidly connected with the low pressure region 28 via an attachment nipple 56. The fuel to be delivered therefore passes from the low-pressure region 28 through the attachment stub 56 into the piston chamber 26. The connection region 58 is provided on the upper end of the pump housing 52. A pressure damping device, not shown, which comprises a pot-shaped cover element, can be fastened to the connecting region 58.

The attachment nipple 56 has a longitudinal axis 62. Furthermore, the attachment stub 56 comprises a tubular outer wall 60 extending rotationally symmetrically about a longitudinal axis 62. The outer wall 60 of the attachment nipple 56 is manufactured by a deep drawing process. Thus, the entire outer wall 60 forms the section 64 that is manufactured in the deep drawing process. However, it is also possible in the sense of the invention for only a single part of the attachment stub 56 to form the section 64 produced in the deep drawing process.

The outer wall 60 of the attachment nipple 56 has a first cylindrical section 66 and a second cylindrical section 68. In this case, it is conceivable for the first cylindrical section 66 and the second cylindrical section 68 to have the same or substantially the same length. As is apparent from fig. 3 and 4, between the two cylindrical sections 66 and 68 there is arranged a groove 70 which is completely circumferential in the circumferential direction, groove-like and directed radially inward and adjoins the two cylindrical sections 66 and 68, respectively. The groove 70 is arranged in the middle region of the attachment stub 56. The recess 70 is produced here by corresponding shaping during the production process of the attachment stub 56 in the deep-drawing method.

Thus, the outer wall 60 is constructed integrally. Furthermore, the outer wall has a constant wall thickness d (see fig. 4). Thus, the inner diameter D2 of the outer wall 60 in the region of the groove 70 is smaller than the inner diameter D1 of the outer wall 60 in the region of the adjoining cylindrical sections 66, 68 (see fig. 4). The recess 70 is therefore introduced into the attachment stub 56 only by corresponding shaping during the deep-drawing process, wherein the degree of shaping required for the formation of the recess 70 is relatively small.

As shown in fig. 2 and 3, a securing means in the form of a snap ring 78 is arranged in the recess 70, said securing means projecting radially outward. In this case, the snap ring 78 can be designed in a known manner and therefore, in particular, not completely circumferentially, but as a ring segment, as is shown strictly schematically in fig. 5. Furthermore, the snap ring 78 has, in particular, ends 77, 79 which are not aligned with respect to one another in the non-arranged state, so that after arrangement in the groove 70, the snap ring 78 is arranged axially clamped in the groove 70 and is thus supported in a loss-proof manner. In particular, the snap ring 78 can be arranged in the groove 70 by means of a snap ring clamp, not shown.

In the radial direction, i.e. perpendicular to the longitudinal axis 62, the snap ring 78 projects beyond the outer side 61 of the outer wall 60 in the state arranged at the groove 70 (see fig. 2 and 3). The attachment section 20, not shown in detail, of the low-pressure line 18 can be fastened to the snap ring 78. The attachment section 20 can be designed in particular as a quick-connect fitting with a snap lock, so that the attachment section 20 can be locked and releasably arranged on the snap ring 78. The attachment socket 56 can be designed in particular such that an attachment section 20 designed according to standard SAE J2044 can be arranged thereon.

Adjacent to the first cylindrical section 66, the outer wall 60 of the attachment socket 56 has a transition region 72 (see fig. 3 and 4). The fastening section 74, viewed in the direction of the longitudinal axis 62 of the attachment stub 56, immediately follows the transition region 72. The attachment socket 56 is fixed to the pump housing 52 by a fixing section 74, the attachment socket 56 being welded to the pump housing 52. The attachment stub 56 has an inlet opening 76, which is arranged at the end of the attachment stub 56 opposite the fastening section 74.

Currently, the entire integrally constructed outer wall 60 of the attachment nipple 56 is integrally manufactured in a deep drawing process. Thus, the attachment stub 56 can be realized cost-effectively. Furthermore, the attachment stub 56 has only locations with a relatively small degree of profiling, so that high strength is continuously present without the presence of defined weak points of strength. The robustness and durability of the attachment stub 56 may thereby be improved.