WO2010055107A1

WO2010055107A1 - High pressure pump

Info

Publication number: WO2010055107A1
Application number: PCT/EP2009/065076
Authority: WO
Inventors: Günter LEWENTZ
Original assignee: Continental Automotive Gmbh
Priority date: 2008-11-17
Filing date: 2009-11-12
Publication date: 2010-05-20
Also published as: DE102008057699A1

Abstract

A high pressure pump (10) for delivering oil and/or fuel for a motor vehicle has a housing (16) and a compressor unit (18) which is arranged at least partially in the housing (16) and has the purpose of performing high pressure compression. A feed line and a high pressure line (24) are connected to the compressor unit (18). According to the invention, the housing (16) is manufactured from a plastic, wherein the plastic is configured for a degree of component rigidity which is higher than the pressure of the feed line and lower than the pressure of the high pressure line (24). Using plastic for the housing (16) reduces the weight of the high pressure pump (10) so that the fuel consumption of a motor vehicle which uses such a high pressure pump (10) can be reduced.

Description

description

high pressure pump

The invention relates to a high-pressure pump, for example an oil pump and / or a fuel pump, by means of which oil and / or fuel for a motor vehicle can be required.

From EP 1 416 153 B1, a high-pressure pump is known which, as a fuel pump, requires fuel for a common rail system of a motor vehicle and compresses the fuel to a pressure of approximately 1 000 to 2 000 bar. The high-pressure pump has a housing made of aluminum into which a compressor unit for high-pressure compression is embedded. The compressor unit has a driven by an eccentric piston, which is guided in a cylinder of a cylinder head. The aluminum housing has blind holes with an internal thread, with the help of which the cylinder head made of steel can be screwed to the aluminum housing. Channels are provided within the housing to form an inlet conduit for conveying fuel from a fuel tank to the compressor unit. After compression, the compressed fuel leaves the compressor unit via a high-pressure line connected to the cylinder head and is led to a common rail system.

The disadvantage of such a high-pressure pump is that the consumption of a motor vehicle which uses such a high-pressure pump is too high.

It is the object of the invention to provide a high-pressure pump, by means of which the consumption of a motor vehicle can be reduced.

The solution of the problem is erfmdungsgemaß by the features of claim 1. Advantageous embodiments of the invention are specified in the dependent claims. The inventive high-pressure pump for requesting oil and / or fuel for a motor vehicle has a housing into which at least partially a compressor unit for high-pressure compression is arranged. With the Verdichterein ^¬ standardize a supply line and a high pressure line is connected. Erfmdungsgemaß the housing is made of a plastic, wherein the plastic for a component strength above the pressure of the supply line and below the pressure of the high-pressure line is designed.

The fact that the housing is not made of metal, but of a plastic, the weight of the high-pressure pump can be significantly reduced. Due to the reduced weight of the high-pressure pump, the consumption of a motor vehicle using such a high-pressure pump can be reduced, whereby additionally the CO ₂ emissions can be reduced. The Kunststoffmateπal of the housing is designed insbeson ^¬ particular taking into account only the pressure in the supply line shortly before the compressor unit. This makes it possible to produce a particularly light and / or a particularly inexpensive plastic for the housing auszuwäh ^¬ len. In particular, only the compressor unit and downstream in the flow direction components, such as in particular the high pressure line, designed for the pressure of the high pressure line of about 1 000 to 2 000 bar or even higher pressures. In this case, the high-pressure line is not formed by the plastic of the housing, but by its own component, for example a steel tube, which may be guided outside the housing and / or inside the housing. By dividing the high-pressure area and the low-pressure area into different components, it is possible to use materials which are particularly pressure-resistant only for the high-pressure area and low-cost and lightweight plastics for the low-pressure area. In particular, it is possible to surround the compressor unit and / or the cylinder head with the compressor unit with the plastic of the housing during the production of the housing by injection molding. There- By it is possible to avoid a direct screwing the compressor unit with the housing and, if necessary, provide an indirect screw, for example by means of a injected in the housing thread.

In particular, with the housing connected to the feed line pre-pressure pump, in particular a gerotor pump, attached, wherein the pre-pressure pump has a Vordruckpumpengehause, which is made of a plastic, wherein the plastic designed for a component strength above the pressure of the supply line and below the pressure of the high pressure line is. For the Vordruckpumpengehause in particular the same plastic can be used, which is also used for the housing of the high-pressure pump. The ubπ- gen components of the pre-pressure pump can be made entirely or partially of plastic. For example, if the pre-pressure pump is designed as a toothed ring pump, the inner gear and the outer gear ring can be made of plastic. Thereby, the weight and the cost of the high pressure pump can be additionally reduced.

Particularly preferably, the housing and / or the Vordruckpum ^¬ pengehause made of a thermosetting plastic and / or thermoplastic, which is in particular fiber-reinforced. For example, the Kunststoffmateπal of the housing glass fibers in order to increase the mechanical strength. This allows Kunststoffmateπalien train with a bending strength of 230 MPa ± 10% according to ISO 178, a tensile strength of 135 MPa ± 10% according to ISO 527 and a compressive strength of 360 MPa ± 10% according to ISO 604. As thermosetting and / or thermoplastic plastics these easily form the housing or the Vordruckpumpengehause and umspπtzen the high pressure components.

In a preferred embodiment, the high-pressure line is connected outside the housing to the compressor unit. The high-pressure line can be securely fastened, for example via a screw-type closure with the compressor unit, so that even pressures of 2,000 bar or even higher pressures do not lead to leaks. Furthermore, the high-pressure line can be mounted separately, that is, after the production of the housing. In particular, a comparable material pairing, for example steel / steel, can be used for the connection of the high-pressure line to the compressor unit, so that it is not necessary to allow the high-pressure line to be overmolded by the housing.

In particular, the housing has the supply line. The Zu ^¬ supply line can be formed by the plastic of the housing. The supply line can already be taken into account by injection molding during the production of the housing or can only be produced later, for example by drilling in the housing.

Particularly preferably, the compressor unit has an at least partially protruding from the housing cylinder head, wherein the cylinder head has a cylinder which is made of a metallic material, in particular steel. In particular, the cylinder head is made of a metallic material, in particular steel. In principle, it is sufficient if only the cylinder of the cylinder head is made of a material that can withstand the pressures occurring in the high-pressure line. In this case, the high pressure line is in particular directly connected to the cylinder. In particular, if the cylinder head and the Zylin ^¬ should be designed emstuckig, the entire cylinder head including the cylinder made of a metallic material see, especially steel.

In the case where the high-pressure pump has exactly one compressor unit, the high-pressure line connected to the compressor unit can be connected directly to a rail of a common-rail system. Even if two or more compressor units are provided, the compressor units can be connected via their respective high-pressure line to the rail. In a preferred embodiment are at least two compressor units are provided, which are each connected to a high pressure line, wherein the high pressure line are connected outside the housing via a connecting piece with a manifold, wherein the manifold, in particular for connection to a common rail system is provided. If necessary, the high-pressure lines can be fastened by means of suitable non-return valves, in each case with the connecting piece, for example via a screw connection. The fact that the manifolds are first merged, it is possible to connect via only one port, the high ^¬ pressure pump with the common rail system. It is therefore only the manifold connected to the rail of the common rail system. Preferably, the length of the high-pressure lines between the compressor unit and the connection piece is substantially the same length. This avoids an irregular pressure profile within the manifold.

In a particularly preferred embodiment, the compressor unit and / or the high-pressure line is connected to the housing via at least one connecting element extending into the housing, wherein the connecting element has a higher strength than the housing. The Verbindungsele ^¬ ment can be at least partially embedded, in particular in the housing.

Specifically, the compressor unit on a cylinder head which is buildin ^¬ Untitled via the connecting member to the housing. As a result, the cylinder head with the housing, even with a Mateπalpaarung steel / plastic, be securely connected.

The connecting element has in particular a thread, preferably internal thread. As a result, a secure screw can be ensured, even if the housing has an unfavorable for steel screws or steel nuts material, such as plastic, aluminum or magnesium. Particularly preferably, the connecting element has a ring ^¬ anchor with at least two connection points. This makes it possible to provide exactly one connection element for connection to the respective compressor unit in the housing, for example to inject it into the housing, and to provide a plurality of connection possibilities between the connection element and the compressor unit. Through the annular armature, which is preferably the cylinder of the compressor unit kreisπngfor- mig, in particular coaxially surrounds, a high holding force can be provided, so that the compressor unit during loading ^¬ drive can not break away from the housing.

Particularly preferably, the housing is produced by a manufacturing method in which the material of the housing is flowable, and the connecting element is arranged captive in the manufacture of the housing at least partially in the housing. This makes it possible to give the connecting element a complicated shape, which allows a particularly strong, in particular form-fitting connection between the connecting element and the housing. In the production, for example during casting and / or during injection molding, the housing can enclose the connecting element and also penetrate into cavities and intermediate spaces of the threaded implant. This leads to a particularly strong form-fitting connection of the Verbmdungselements with the housing.

In a further embodiment, the connecting element is connected via a self-tapping screw to the housing. As a result, the connecting element can subsequently be introduced captively in a manner comparable to a wood screw in the housing. Through the groove between the thread flanks results in a high holding surface between the connecting element and the housing, so that a secure attachment of the compressor unit is ensured with the housing.

Preferably, the connecting element has at least one retaining surface with a surface portion in the axial direction of the connecting element within the housing. When drove the compressor unit is pulled due to the high pressure within ^¬ half of the compressor unit on the Verbmdungselement results in a sufficiently high holding force on the holding surface, which holds the compressor unit safely. The holding surface is formed in particular by ^¬ Hmterschneidungen which particular distribute the forces exerted on the Verbmdungselement over a larger surface within the housing Formschlussig.

In particular, the Verbmdungselement within the Ge ^¬ housing on a coiled holding mandrel and / or splayed support arms and / or a holding paragraph. As a result, intersections occur within the housing, due to which forces acting on the connecting element can be distributed over a larger area of the housing. This makes it easier to comply with maximum allowable voltages within the housing and to choose a material for the housing with comparatively low maximum allowable voltages.

Preferably, the individual outer surfaces, in particular the holding surface, are connected to one another via a radius, sharp edges are thereby avoided, so that the notch effect of the connecting element embedded in the housing is reduced. The edges occurring in the connecting element are therefore not only deburred but rounded. For example, the connecting member is made by forging, so that the rounded transitions between the individual ^¬ NEN outer surfaces can be defined by the forging mold already.

Particular preference is given to the housing, connected to said compaction ^¬ tereinheit precompression pump, in particular a gerotor pump, attached via a Verbmdungselement. The fastening of the pre-pressure pump can be connected to the housing as explained above with reference to the compressor unit. The invention with reference to the drawings lying on ^¬ will be explained with reference to preferred exemplary len Ausfuhrungsbeispie-. Show it:

1 is a schematic perspective rear view of a erfmdungsgemaßen high-pressure pump,

Fig. 2: a schematic perspective top view of

High-pressure pump of FIG. 1,

3 shows a schematic sectional view of a connecting element in a first embodiment,

4 shows a schematic sectional view of a connecting element in a second embodiment,

5 shows a schematic sectional view of a connecting element in a third embodiment,

6 shows a schematic perspective view of a

Verbmdungselements in a fourth embodiment and

7 shows a schematic perspective view of a connecting element in a fifth embodiment.

In the case of the high-pressure pump 10 shown in FIGS. 1 and 2, fuel can reach an admission pressure pump 14 via an intake 12. In the booster pump 14, the fuel may, for example, to a pressure of 2 to 10 bar is compressed ^¬ the. This pressure is sufficient to lubricate the moving parts within the high-pressure pump 10 with fuel. The fuel then passes from the admission pressure pump 14 via supply lines provided within a housing 16 to two compressor units 18. Alternatively, only one compressor unit 18 or three or more compressor units 18 can be provided. The compressor units 18 each have a cylinder in which the fuel is compressed by means of a piston. The piston is actuated by an eccentric or roller pusher disposed within the housing 16 which is driven by a drive shaft 20. The compressor units 18 each have a cylinder head 22, which may be made of a stainless steel, in order to withstand the compaction resulting pressures of 1 000 to 2 000 bar or 2 500 bar and higher pressures can. The compressed on this high-pressure fuel passes through a connected to the cylinder head 22 outside the hous ^¬ ses 16 high-pressure line 24 to a connection piece 26, which is designed in the illustrated embodiment as a T-piece. To the connecting piece 26 may be followed by a manifold 28, which leads to a common rail system, where the fuel via injectors in the

Combustion chamber of an internal combustion engine can be injected.

Since the high pressure is generated only in the cylinder head 22, and therefore no high pressure occurs in the housing 16, the housing 16 is made of plastic. The housing 16 is closed on the bottom side by a cover 30, which may be made of aluminum or plastic. In the head area, the housing 16 is closed by a Vordruckpumpengehause 32, which is part of the priming pump 14. The precompression pump housing 32, the cover 30 and / or in particular the cylinder head 22 34 may be connected to a captive in the housing 16 injected Verbin ^¬-making element 36 through at least either one screw.

The connecting element 36 shown in FIG. 3 has a blind bore 38 which is provided with an internal thread 40. About the internal thread 40, the screw 34 can be attached. The connecting member 36 further includes splayed support arms 42 providing a support surface 44 with a Flachen- share in the axial direction of the Verbmdungselements 36 ^¬. About the retaining surfaces 44 can act on a connecting element 36 force on a larger area of the housing 16 are distributed, so that even larger forces can be removed via the housing 16.

In the illustrated in Fig. 4 of the exemplary encryption bmdungselements 36 36, the Verbmdungselement a ge ^¬ overcome retaining tab 46. The winding retaining mandrel 46 likewise provides a holding surface 44 with a surface portion in the axial direction of the wrought implant 36. Compared to the connecting element 36 shown in FIG. 3, in the case of the connecting element 36 shown in FIG. 4, an attacking force is removed into deeper areas of the housing 16.

In the exemplary embodiment of the connecting element 36 shown in FIG. 5, the connecting element 36 has a

Holding projection 48, through which a Hmterschneidung is formed to form a retaining surface 44 with a flat portion in the axial direction of the connecting element 36.

The connecting element 36 shown in FIG. 6 has a substantially spherical holding projection 48 in comparison to the connecting element 36 shown in FIG. 5. Furthermore, the retaining surface 44 is rounded. This results in a particularly low notch effect in the region of the holding projection 48 and the holding surface 44.

In the exemplary embodiment of the connecting element 36 shown in FIG. 7, the connecting element 36 has a ring anchor 50 which provides a plurality of connecting points 52. In the illustrated embodiment, the ring anchor 50 at the connection points 52 through holes, which are provided with an internal thread 40. Over the distance ranges between two adjacent connection points 52 a holding surface 44 is provided in order to distribute the forces acting on the Verbmdungselement to a larger Be ^¬ rich within the housing sixteenth In the illustrated exemplary embodiment, the ring anchor 50 is designed kreisrmgformig, so that the ring anchor 50 coaxial with the ZyIm- the compressor unit 18 can be arranged. The ring anchor 50 may in particular have a peripheral circumferential groove in order to form additional Hmterschneidungen and to increase the positive engagement. Furthermore, the ring anchor 50 may have a holding lug and / or be bevelled in cross-section, for example, substantially trapezoidal, designed to form Hmterschneidungen.

LIST OF REFERENCE NUMBERS

10 high pressure pump

12 enema

14 pre-pressure pump

16 housing

18 compressor unit

20 drive shaft

22 cylinder head

24 high pressure line

26 connector

28 Manifold

30 lids

32 pre-pressure pump housing

34 screw

36 connecting element

38 blind hole

40 internal thread

42 holding arm

44 holding surface

46 thorn

48 holding heel

50 ring anchors

52 attachment point

Claims

claims

1. High-pressure pump for demanding oil and / or fuel for a motor vehicle, comprising a housing (16), an at least partially in the housing (16) ^{arrange ¬} th compressor unit (18) for high-pressure compression, connected to the compressor unit (18) inlet - line and one to the compressor unit (18) connected to the high pressure line (24) characterized in that the housing (16) is made of a plastic, wherein the plastic for a component strength above the pressure of the supply line and below the pressure of the high pressure line ( 24) is designed.

2. High-pressure pump according to claim 1, characterized in that with the housing (16) connected to the feed line pre-pressure pump (14), in particular a Gero ^¬ gate pump, is fixed, wherein the pre-pressure pump (14) has a Vordruckpumpengehause (32) from a

Plastic is made, the plastic for a component strength above the pressure of the supply line and below the pressure of the high-pressure line (24) is designed.

3. High-pressure pump according to claim 1 or 2, characterized in that the housing (16) and / or the pre-pressure pump housing ^¬ (32) is made of a thermosetting plastic and / or thermoplastic, which is in particular fiber-reinforced.

4. High-pressure pump according to one of claims 1 to 3, characterized in that the high-pressure line (24) outside the housing (16) with the compressor unit (18) is connected is the.

5. High-pressure pump according to one of claims 1 to 4, characterized in that the housing (16) has the supply line.

6. High-pressure pump according to one of claims 1 to 5, characterized in that the compressor unit (18) at least partially from the housing (16) outstanding cylinder head (22), wherein the cylinder head (22) comprises a cylinder which consists of a metallic Mateπal, especially steel, is made.

7. High-pressure pump according to claim 6, characterized in that the cylinder head (22) is made of a metallic material, in particular steel.

8. High-pressure pump according to one of claims 1 to 7, characterized in that at least two compressor units

(18) are provided, which are each connected to a high-pressure line (24), wherein the high-pressure lines (24) outside the housing (16) via a connecting piece (26) are connected to a manifold (28), wherein the collecting line ( 28) is provided in particular for Ver ^¬ binding with a common rail system.

9. High-pressure pump according to claim 8, characterized in that the length of the high pressure lines (24) between the compressor unit (18) and the connecting piece (26) is substantially equal in length.

10. High-pressure pump according to one of claims 1 to 9, characterized in that the compressor unit (18) and / or the high pressure line (24) via at least one in the housing (16) extending connecting element (36) is connected to the housing (16) wherein the connecting element (36) has a higher strength than the housing.