WO2014079625A1 - Valve device for use in a fuel injection system - Google Patents

Abstract

A valve device (34) is described for use in a fuel injection system, with an inlet (32) for connecting to a delivery chamber of a high pressure pump and with an outlet (36) for connecting to a high pressure accumulator, wherein the valve device (34) comprises an outlet valve (48) which opens in a delivery phase of the high pressure pump in order to produce a fluid connection between the delivery chamber and high pressure accumulator and closes in a suction phase of the high pressure pump, wherein the valve device (34) comprises a pressure limiting valve (50) which opens if a maximum pressure is exceeded, in order to produce a fluid connection between the high pressure accumulator and the delivery chamber, wherein a first valve of the valves outlet valve (48) and pressure limiting valve (50) can be flowed through along a central first flow path (78), and wherein a second valve of the valves outlet valve (48) and pressure limiting valve (50) can be flowed through along a second flow path (80) which surrounds the first flow path (78).

Description

 description

title

 Valve assembly for use in a prior art fuel injection system

The invention relates to a valve device according to the preamble of claim 1.

From WO 201 1/068524 A1 a valve device for use in a fuel injection system is known. In this valve device is a

Valve seat member provided which forms a valve seat for the pressure relief valve on an input side and a valve seat for the outlet valve on an output side.

The known from WO 201 1/068524 A1 valve device is

Tolerance sensitive and requires a complex production.

Proceeding from this, the present invention has the object to provide a most economical manufacturable valve device.

Disclosure of the invention

The problem underlying the invention is achieved by a valve device according to claim 1. Advantageous developments are in the

Subclaims specified. Features which are important for the invention can also be found in the following description and in the drawing, wherein the features, both alone and in different combinations, can be important for the invention, without being explicitly referred to again. In the valve device according to the invention, the flow paths of the outlet valve and the pressure relief valve surround each other. In this way, a known from WO 201 1/068524 A1 serial arrangement of exhaust valve and pressure relief valve can be avoided. In the case of the valve device according to the invention, separately provided valve seat elements may be provided in each case for the outlet valve and the pressure limiting valve, so that the tolerances of the valve seats do not influence one another. This simplifies the manufacture of the valve device.

The flow paths surrounded one another have the further advantage that a comparatively compact structural unit can be created, which takes up only little space. In addition, an optionally desirable structural integration of the valve device in a housing of the high-pressure pump is particularly well feasible.

In addition, it allows the surrounding arrangement of the

Flow paths at least the exhaust valve in close proximity to the

To arrange delivery chamber so that a dead volume is reduced and the efficiency of the high-pressure pump is increased.

In a preferred embodiment it is provided that the first

Flow path and the second flow path are concentric with each other. In particular, the first flow path runs along a first

Flow axis; the second flow path is annular in cross-section and surrounds the first flow path.

In order to simplify the assembly of the valve device in a fuel system, it is proposed that the outlet valve and the pressure relief valve are connected to each other and form an assembly. This also has the advantage that the functionality of this module, so the functionality of both the exhaust valve and the pressure relief valve, under

Use of the input and the output of the valve device in only one Prüfaufspannung can be checked.

In a particularly preferred embodiment, it is provided that the first valve is arranged on or in an annular sleeve, which with a Valve seat member of the second valve is connected. This allows a particularly compact and tolerant insensitive arrangement of the components of both valves.

In a further embodiment it is provided that the outlet valve and / or the pressure limiting valve has or have a valve spring, which is supported or supported on a housing of the valve device. This makes it possible in the case of using a valve spring on a conceivable separate component or separate components for supporting the

To dispense with valve spring.

The housing of the valve device may be provided separately from a housing of the high-pressure pump. However, it is preferred that at least one housing section of the valve device is provided by the housing of the high-pressure pump.

In a further embodiment of the invention it is provided that the outlet valve and / or the pressure relief valve has or have a resilient, in particular designed as a metal disc valve body. This makes it possible to dispense with a separate valve spring. The valve body thus has both a sealing function by interaction with a particular stationary valve seat and a closing function by providing a closing force by reshaping a deformed as a result fluid pressure resilient valve body.

Preferably, the valve bodies are mass-produced as a stamped part.

A particularly compact arrangement results when the first valve has a disk-shaped valve body, in particular a circular disk-shaped valve body, and / or when the second valve has a

annular disk-shaped valve body, in particular a

having annular disc-shaped valve body. In this way, the valves can be made particularly flat in the region of the valve seat. In addition, the manufacture of the valve body, in particular if they are in the form of a metal disc simplified. A further saving of installation space results when the valve body of the first valve and the valve body of the second valve extend in mutually parallel planes. These levels can be offset from each other or these levels can be aligned with each other, so be arranged in a common plane.

In a further preferred embodiment it is provided that the outlet valve and / or the pressure limiting valve has or have a limiting element for limiting an opening stroke of the valve body. This has the advantage that a maximum opening travel of the valve body can be limited. This shortens the movement and / or deformation travel of the valve body required from an open position to a closed position, so that short valve closing times are achieved. In addition, the velocities occurring upon impact of the valve body on the valve seat can be reduced, so that a reduced by the impact of the valve body on the valve seat wear is reduced and the life of the valve is increased.

In a particularly preferred embodiment it is provided that the first valve has a valve seat, which at the same time as

Limiting element for limiting an opening stroke of the valve body of the second valve is effective. This allows a reduction in the number of parts of the valve device and thus a particularly economical production of the valve device.

Hereinafter, exemplary embodiments of the invention will be explained with reference to the drawings. In the drawing show:

Figure 1 is a simplified diagram of a fuel injection system with a high-pressure pump, a valve device and a

 High-pressure reservoir;

Figure 2 is a simplified sectional view of a first embodiment of the valve device according to Figure 1; Figure 3 is a simplified sectional view of a second embodiment of the valve device according to Figure 1; and

FIG. 4 is a simplified sectional view of a third embodiment of the valve device according to FIG. 1.

FIG. 1 shows a fuel system 10 of an internal combustion engine in a greatly simplified representation. From a fuel tank 12 fuel via a suction line 14, by means of a prefeed pump 16, via a low-pressure line 18, and via one of an electromagnet 20 operable

 Quantity control valve 22 of a high-pressure pump 24 is supplied. Downstream, the high pressure pump 24 via a high pressure line 26 to a

High-pressure accumulator 28 connected. The high-pressure pump 24 has a delivery chamber 30, which with a

Input 32 of a valve device 34 is connected. An output 36 of the valve device 34 is connected via the high-pressure line 26 to the high-pressure accumulator 28. It is understood that the quantity control valve 22 and / or the valve device

34 may be formed as a unit with the high-pressure pump 24.

For example, the quantity control valve 22 may be an intake valve of the

Be high pressure pump 24. The quantity control valve 22 may also have a different actuator than the electromagnet 20, for example a piezoelectric actuator or a hydraulic actuator.

During operation of the fuel system 10, the prefeed pump 16 delivers fuel from the fuel tank 12 into the low-pressure line 18

Quantity control valve 22, the delivery chamber 30 of the high pressure pump 24 supplied amount of fuel.

The valve device 34 comprises two valves whose arrangement and construction are explained below with reference to FIGS. 2 to 4. These valves include an exhaust valve and a pressure relief valve. The function of the outlet valve is to open in a delivery phase of the high-pressure pump 24 to a fluid connection between the

Conveyor chamber 30 and the high-pressure accumulator 28 produce, so that the

High-pressure accumulator 28 can be filled with pressurized fluid. In a suction phase of the high-pressure pump 24, the outlet valve closes in order to prevent undesired reflux of fluid from the high-pressure accumulator 28 into the delivery chamber 30.

The pressure relief valve is normally closed and prevents in this closed position a backflow of fluid from the

 High-pressure accumulator 28 in the delivery chamber 30. However, if a maximum pressure is exceeded upstream of the valve device, opens

Pressure relief valve and allows a pressure reduction by establishing a fluid connection between the high-pressure accumulator 28 and the delivery chamber 30.

The valve device 34 shown in Figure 2 extends along a central longitudinal axis 38 between the input 32 and the output 36. The valve device 34 has a housing 40 which, for example. Two housing parts 42 and 44 includes. The housing parts 42 and 44 define a housing space

46 for disposing an exhaust valve 48 and a pressure relief valve 50.

The housing 40, in particular the housing part 42, is advantageously formed in one piece with the housing of the high-pressure pump 24. The second housing part 44 is, for example, a pressure-tight connection to the housing part 42 connectable high-pressure connection.

The housing space 46 has a preferably cylindrical boundary 52.

The outlet valve 48 and the pressure limiting valve 50 together form an assembly 54.

The outlet valve 48 has a preferably annular design

Valve seat member 56, which is in particular pressed by means of a press fit into the boundary 52 of the housing space 46. The exhaust valve 48 also includes a valve body 58 which annular disc-shaped

is trained. In a preferred embodiment, the valve body is connected in an annular connecting portion 60 with the valve seat member 56, for example, welded.

The valve body 58 is designed in particular as a metal disc and covers in a closed position in the valve seat element 56 distributed along a circumference arranged flow channels 62nd

The valve seat member 56 surrounds an annular sleeve 64 connected to the valve seat member 56. The annular sleeve 64 extends from the first

Valve seat member 56 in the direction of the output 36 of the valve device 34 and has an output 36 facing the output end 66. The end 66 serves to arrange a valve seat element 68 of the pressure limiting valve 50. The valve seat element 68 is connected to the annular sleeve 64 in particular by means of a press fit.

The valve seat member 68 cooperates with a valve body 70 (eg in the form of a sphere). The valve body 70 is by means of a

 Valve body guide member 72 out, which in turn is guided in a valve spring 74 and presses the valve body 70 by means of the valve spring 74 with a closing force against the valve seat member 68.

The valve spring 74 is supported at one end on the valve body guide element 72 and at the other end on a support surface 76 of the housing 40.

The bias of the valve spring 74 and thus a maximum pressure at which the pressure relief valve 50 opens, can be adjusted by adjusting the position of the valve seat member 56 of the exhaust valve 48 along the axis 38.

In the embodiment shown in Figure 2 is the

Pressure limiting valve 50 is arranged centrally and is traversed in the event that a maximum pressure is exceeded, along a first flow path 78 which corresponds substantially to the longitudinal axis 38 of the valve device 34. The outlet valve 48 is flowed through in a delivery phase of the high-pressure pump 24 along a second flow path 80, which is arranged radially relative to the first flow path 78.

The opening of the outlet valve 48 is accompanied by a deformation of the radially inner part of the valve body 58, so that this part is lifted from the flow channel 62 or the flow channels 62 of the valve seat member 56. Due to the spring elasticity of the valve body 58, a closing force can be provided by the valve body 58 itself, which is a

Rebuilding of the valve body 58 causes when the high-pressure pump 24 passes through a suction phase, in which the delivery chamber 30 increases.

It is advantageous if a limiting element 82 is provided to limit the opening travel of the valve body 58. The limiting element 82 is annular in a preferred embodiment and in particular connected to the annular sleeve 64, in particular pressed.

The valve seat member 56 and / or the valve body 58 are preferably provided in the form of stamped parts.

An embodiment of a valve device 34 shown in FIG. 3 has a structure comparable to that described above with reference to FIG. 2 of the valve device 34. Therefore, reference is made to the above description. Below are the

 Differences between the valve device 34 according to Figure 3 and the

Valve device 34 explained according to Figure 2.

In the valve device 34 according to FIG. 3, the valve seat element 68 of the pressure limiting valve 50 is provided in the form of a deep-drawn / stamped part. The

Valve seat member 68 has a ring portion 84 which is slipped onto the annular sleeve 64. The valve seat element 68 further has at least one passage opening 86 for the flow through a central first

Flow path 78 on. In a closed position of the pressure limiting valve 50, the at least one passage opening 86 is closed by means of a valve body 70, which is provided in the form of a disk, in particular in the form of a circular disk and more preferably in the form of a metal disk. The valve body 70 is connected to the valve seat member 68 along a radially outer ring portion.

As seen along the first flow path 78, a deformation path of the valve body 70 is limited by means of a limiting element 88. The

Limiting element 88 is preferably provided in the form of a deep-drawn / stamped part and more preferably directly connected to the valve seat element 68. The limiting element 88 has passage openings, not shown in the drawing, for the passage of fluid along the first flow path 78.

The ring portion 84 of the valve seat member 68 not only serves to attach the valve seat member 68 to the annular sleeve 64, but acts with its the valve body 58 of the exhaust valve 48 facing end face simultaneously as a limiting element for limiting an opening travel of the valve body 58th

The valve bodies 58 and 70 extend in mutually parallel planes 90 and 92, which are spatially adjacent to each other, preferably have a maximum distance of 50 mm, in particular of 30 mm. In the above described with reference to Figures 2 and 3

 Embodiments, the pressure relief valve 50 is arranged centrally as the first valve and the outlet valve 48 arranged as a second valve with respect to the pressure relief valve 50 radially au Shen. Hereinafter, with reference to Figure 4, an embodiment of a

Valve device 34 described in which the outlet valve 48 is arranged centrally as a first valve. Here, the exhaust valve 48 has a structure identical to the structure of the pressure-limiting valve 50 described above with reference to FIG. However, the outlet valve 48 is flowed along the first flow path 78 between the input 32 and output 36, so that along the axis 38, first the Valve seat member 56, then the valve body 58 and finally the

Limiting element 82 are provided.

The pressure limiting valve 50 according to FIG. 4, which can be flowed through along a second flow path 80 when a maximum pressure is exceeded in one direction from the outlet 36 to the inlet 32, is arranged at the end of the annular sleeve 64 facing the outlet 36. The valve body 70 of the pressure limiting valve 50 is provided on the side 32 of the valve seat member 68 facing the input.

Claims

Valve means (34) for use in a fuel injection system (10), having an inlet (32) for connection to a delivery chamber (30) of a high pressure pump (24) and having an outlet (36) for connection to a high pressure accumulator (28) Valve device (34) a Exhaust valve (48), which in a delivery phase of High-pressure pump (24) for establishing a fluid connection between the delivery chamber (30) and high-pressure accumulator (28) opens and in a suction phase of the high-pressure pump (24) closes, wherein the valve means (34) comprises a pressure relief valve (50) which when exceeding a maximum pressure for the production a fluid connection between the High-pressure accumulator (28) and the delivery chamber (30) opens, characterized in that a first valve of the valves outlet valve (48) and pressure relief valve (50) along a central first flow path (78) can be flowed through and that a second valve of the valves Exhaust valve (48) and pressure relief valve (50) along a first flow path (78) surrounding the second flow path (80) can be flowed through. Valve means (34) according to claim 1, characterized in that the first flow path (78) and the second flow path (80) are concentric with each other. Valve device (34) according to one of the preceding claims, characterized in that the outlet valve (48) and the Pressure relief valve (50) are interconnected and a Form assembly (54). Valve device (34) according to one of the preceding claims, characterized in that the first valve on or in an annular sleeve (64) is arranged, which is connected to a valve seat member (56, 68) of the second valve. Valve device (34) according to one of the preceding claims, characterized in that the outlet valve (48) and / or the  Pressure limiting valve (50) has or have a valve spring (74) which is supported on a housing (40) of the valve device (34) or supported. Valve device (34) according to one of the preceding claims, characterized in that the outlet valve (48) and / or the  Pressure limiting valve (50) has a resilient, in particular designed as a metal disc valve body (58, 70) or have. Valve device (34) according to one of the preceding claims, characterized in that the first valve has a disk-shaped valve body (58, 70), in particular a circular disk-shaped valve body (58, 70), and / or that the second valve has an annular disc-shaped valve body (58, 70), in particular an annular disk-shaped valve body (58, 70). Valve device (34) according to one of the preceding claims, characterized in that the valve body (58, 70) of the first valve and the valve body (58, 70) of the second valve in parallel planes (90, 92) extend. Valve device (34) according to one of the preceding claims, characterized in that the outlet valve and / or the  Pressure limiting valve (50) has a limiting element (82, 84) for  Limiting an opening stroke of the valve body (58, 70) or have. 10. Valve device (34) according to any one of the preceding claims, characterized in that the first valve has a valve seat member (56, 68) which is simultaneously effective as a limiting element (84) for limiting an opening stroke of the valve body (58) of the second valve.