EP3857047A1

EP3857047A1 - Common rail for a fuel injection device

Info

Publication number: EP3857047A1
Application number: EP19759324.7A
Authority: EP
Inventors: Marco Ganser; Richard HAEFELI
Original assignee: Ganser Hydromag AG
Current assignee: Ganser Hydromag AG
Priority date: 2018-09-27
Filing date: 2019-08-21
Publication date: 2021-08-04
Also published as: WO2020064225A1; CH715387A1

Abstract

The invention relates to a common rail (16) having a preferably cube-shaped rail body (26) with a connection surface (44) and a control surface (62). All the hydraulic connections, such as the high-pressure inlet (30), the high-pressure outlets (32), the low-pressure feed inlet (38), the low-pressure feed outlet (40), and the return flow connection (46), are formed on the connection surface side. The fuel quantity regulating valve (64) which is connected between the low-pressure feed inlet (38) and the low-pressure feed outlet (40) is located on the control surface side. Furthermore, the pressure sensors (68), the pressure control valve (70), and the relief valve (72) are arranged on the control surface side. The protective cover (54) closes and protects the connection surface (62) and the elements arranged thereon from the surroundings.

Description

Common rail for a fuel injector

The present invention relates to a common rail for a device for the intermittent injection of high-pressure fuel into combustion chambers of an internal combustion engine, the device having a high-pressure feed pump for fuel, comprising a low-pressure inlet and a high-pressure outlet, and injection valves, according to the preamble of claim 1 and Claim 13. A common rail of this type is disclosed, for example, in the article "3rd generation passenger car common rail from Bosch with piezo inline injectors" in the magazine MTZ 3/2004 volume 65, pages 180 to 189. The known device has a quantity-controlled high-pressure pump which feeds the high-pressure storage space in two tubular rail bodies of the common rail with fuel under high pressure. The high pressure outlets of the rail body are connected to the injection valves. A pressure control valve is arranged on an axial end face of a rail body and a rail pressure sensor is arranged on the opposite axial end face of the rail body.

Furthermore, document WO 95/13474 discloses one

Control device for a filling level variable pump, in which a suction throttle valve serves as a fuel quantity control valve for the high-pressure feed pump. Also electrically controlled suction throttle valves for fuel quantity control from Common Rail

Injectors are well known.

It is an object of the present invention, the common To further develop Rail in such a way that it is compact and revision-friendly.

This object is achieved with a common rail having the features of claims 1 and 13. The common rail has a rail body which has a high-pressure storage space, a high-pressure inlet connected to the high-pressure storage space and the

High pressure storage space has connected high pressure outlets. The high-pressure inlet is intended to be connected to a high-pressure outlet of a high-pressure feed pump, which supplies the common rail with fuel under high pressure. The

High pressure outlets are designed with

Injectors to be connected, with which in a known manner under high pressure

Fuel is intermittently injected into the combustion chambers of an internal combustion engine.

The high-pressure outlet of the high-pressure feed pump is connected to the high-pressure inlet of the rail body, preferably via a high-pressure feed line, while the

High pressure outlets of the rail body preferably over

High-pressure connection lines are connected to the associated injection valves.

According to the invention there is a fuel quantity control valve on the rail body for regulating the

High-pressure feed pump arranged in the amount of fuel. The fuel quantity control valve is preferably designed as an electrically controlled suction throttle valve. The fuel quantity control valve is between a low pressure feed inlet of the rail body and one

Low pressure feed outlet of the rail body switched. Of the Low pressure feed inlet is designed to. to be connected to a low-pressure feed line, which feeds fuel under a low pressure of usually 2 to 10 bar from a fuel storage tank. The low pressure feed outlet is intended to be connected to a low pressure inlet of the high pressure feed pump, preferably via a

Low pressure connection line.

Compared to the prior art, the fuel quantity control valve is no longer integrated into the high-pressure feed pump, but is instead assigned to the commorn rail. On the one hand, this enables a simplified construction of the high-pressure feed pump and, on the other hand, excellent accessibility to the fuel quantity control valve.

For the sake of completeness, it should be mentioned that a low-pressure connection between the

Low pressure feed inlet and the low pressure feed outlet is formed, in which the fuel quantity control valve is connected. The low pressure feed inlet, the

Low pressure feed outlet and the

Low-pressure connection lines are of course separated from the high-pressure storage space.

At least one pressure sensor, which is used to measure the pressure of the fuel in the high-pressure storage space, is preferably also arranged on the rail body.

A pressure control valve is preferably arranged on the rail body and is connected between the high-pressure storage space and a return outlet of the rail body. The pressure control valve preferably serves to reduce the pressure of the fuel in the high-pressure storage space more quickly Reduction of the power required by the internal combustion engine.

The return outlet is preferably connected to the fuel storage tank via a return line. A preferably mechanical pressure relief valve is also preferably arranged on the rail body and is likewise connected between the high-pressure storage space and the return flow outlet. The pressure relief valve serves as a safety element in the event that a maximum permissible pressure of the fuel in the high pressure storage space should be exceeded.

For the sake of completeness, it should be mentioned that the fuel quantity control valve, the pressure sensor and the pressure control valve are designed to be electrically connected to a control device.

The rail body preferably has an at least approximately flat control surface. The fuel quantity control valve is arranged on this. Furthermore, the pressure sensor or the pressure sensors, the pressure control valve and the pressure relief valve are also arranged on this control surface, if these are present. This embodiment leads to a compact, maintenance-friendly structure.

The rail body preferably also has an at least approximately flat connection surface, the

Low-pressure feed inlet and the low-pressure feed outlet, as well as the high-pressure inlet and the high-pressure outlets are arranged on the side of this connection surface in this. If there is a return flow outlet, this is also preferably on the side of the connection surface in this arranged. This embodiment means that all hydraulic connections of the rail body are located in the area of the connection surface. This also leads to a compact and service-friendly structure. The rail body preferably has an at least approximately cuboid design. The control surface and the connection surface are preferably located on sides of the rail body facing away from one another, the control surface and the connection surface running at least approximately parallel to one another. This embodiment is preferably used in V-type engines, the common rail preferably being fastened between the two cylinder banks on the structure of the internal combustion engine, directly or preferably via a protective cover, as described below. The connection surface is preferably located on the side facing away from the structure of the internal combustion engine, so that all hydraulic connections are freely accessible.

In the case of an in-line engine, there is preferably also the possibility of arranging the connection surface at the top, on the cylinder head side, and of providing the control surface on the exposed side facing away from the engine structure. However, it is also possible here to provide the control surface opposite the connection surface on the lower side of the rail housing.

The rail body is preferably formed by a one-piece, integral body, for example one

Steel body.

In a preferred embodiment, the high pressure inlet as well as all or part of the

High pressure outlets in a straight first Row of connections arranged one behind the other in the longitudinal direction of the rail body. The low-pressure feed inlet and the are preferred

Low-pressure feed outlet and, if available, the return outlet in a straight second connection row also arranged in the longitudinal direction one behind the other. The first row of connections and the second

The row of connections are thus aligned at least approximately parallel to one another. If not all high-pressure connections are in the first connection row, a straight third connection row is preferably provided, in which the row is not in the first

Connection row of existing high pressure outlets in

Are arranged one behind the other in the longitudinal direction. In this embodiment, the second row of connections is preferably located centrally between the first and the third

Connection row. This embodiment is preferably used for V engines.

The fuel quantity control valve and, if present, the pressure sensor or pressure sensors, the pressure control valve and the like are preferred

Pressure relief valve arranged in a straight line in the longitudinal direction one behind the other. The control row and the second connection row are preferably located in a longitudinal center plane of the rail body.

The storage space is preferably delimited by a longitudinal bore running through the rail body in the longitudinal direction, which is closed at both ends, for example by means of locking screws. From the high-pressure inlet and the associated high-pressure outlets, connecting holes lead to the longitudinal bore, which, however, are in the Cross-section are smaller than the longitudinal bore. The axes of the longitudinal bore and the connection connection bores are preferably located in the same plane in which the first row of connections is located, this plane preferably running parallel to the longitudinal center plane of the rail body and at least approximately at right angles to the connection surface.

If a third row of connections is present, there is preferably a second longitudinal bore which runs in the longitudinal direction through the rail body and is closed at both ends, to which further connecting connection bores which are smaller in cross section lead from the associated high-pressure outlets. The two parallel longitudinal bores are preferably over a perpendicular to the longitudinal center plane

Connection bore connected to each other in terms of flow.

In this embodiment, the high pressure inlet and half of the high pressure outlets are preferably assigned to the first row of connections, while the other half of the high pressure outlets are assigned to the third row of connections. On the one hand, this offers good accessibility and on the other hand the possibility for short high-pressure connection lines between the

High pressure connections and the injection valves. Next is thanks to the at least approximately cuboid

Embodiment of the rail body and the longitudinal bores and Ouerbohrungen enables simple machining.

The longitudinal bore mentioned can be a material lock bore or the longitudinal bores mentioned can be

Sachlock bores to be formed. It is only appropriate to provide a closure formed at each end, for example by a locking screw.

As already mentioned above, there is preferably a protective cover arranged on the rail body, which surrounds the fuel quantity control valve and the pressure sensor, the pressure control valve and the pressure relief valve, if these are present, to protect them from the environment. Thus, the control and measurement elements (such as the fuel quantity control valve and the pressure control valve and the pressure sensor or pressure sensors) as well as safety elements (such as the pressure relief valve) are protected against the harsh environment by the protective cover.

In the assembled state, the protective cover preferably lies with its cover side facing away from the rail body against the structure of the internal combustion engine, and the rail body is fastened to the structure by means of screws, the screws running outside of or through the protective cover. On the one hand, this enables excellent protection for the control and measuring elements as well as on the safety elements, and on the other hand, it enables simple mounting on the structure of the

Internal combustion engine and free access to the hydraulic connections.

An electrical plug socket is preferably arranged on the protective cover, preferably on the jacket side, with which the electrically controlled

Fuel flow control valve and, if available, the

Pressure sensors and the pressure control valve are connected via electrical lines. A plug can be connected to the socket, from which a control cable to

Control of the injector runs. In a further aspect of the present invention, the common rail has a rail body defining a longitudinal direction, which has a high-pressure storage space, a high-pressure inlet connected to the high-pressure storage space and high-pressure outlets connected to the high-pressure storage space. Again it is

High pressure inlet is designed to be connected to the high pressure outlet of the high pressure feed pump. The high pressure outlets are designed to be connected to injectors.

According to the invention, the rail body has a control surface which runs at least approximately parallel to the longitudinal direction and is at least approximately flat, on which at least one control element, such as a fuel quantity control valve for regulating the flow rate of the

High-pressure feed pump drawn fuel quantity and a pressure control valve, and / or at least one measuring element, such as a pressure sensor or pressure sensors, and / or at least one safety element, such as a pressure relief valve, are arranged.

All existing control and measuring elements as well as safety elements are preferably arranged on the control surface side of the rail body.

However, it should be noted that in this aspect of the invention, for example

Fuel flow control valve, as in the state of the

Technology in which the high-pressure feed pump can be located and is therefore not assigned to the common rail and is not attached to the rail body. Furthermore, the rail body has an at least approximately parallel to the longitudinal direction approximately flat connection surface, the high-pressure inlet and the high-pressure outlets being arranged on the side of the connection surface in the region thereof.

The advantages of this aspect of the invention are the same as stated in connection with the features in question above.

Here too, the rail body is preferably at least approximately cuboid, the control surface and the connection surface facing away from one another, running at least approximately parallel to one another, with the advantages as described above in this regard.

In this aspect of the invention, too, a protective cover is preferably arranged on the rail body and surrounds the control and measuring elements and security elements arranged on the control surface in a protective manner against the environment.

For the sake of completeness, it should be mentioned that in this aspect of the invention, the common rail can have the same preferred embodiments as explained above. The present invention also includes a device having a high-pressure feed pump for fuel, comprising a low-pressure inlet and a high-pressure outlet, and injection valves for the intermittent injection of high-pressure fuel into combustion chambers

Internal combustion engine with a common rail according to the invention.

The invention is explained in more detail using an exemplary embodiment shown in the drawing. It show purely schematically:

1 in an isometric view obliquely from above, a device for the intermittent injection of high-pressure fuel into combustion chambers of an internal combustion engine with a high-pressure feed pump, a common rail fed by this and injection valves supplied by the common rail with high-pressure fuel;

Fig. 2 in an isometric view obliquely from above

Common Rail according to Fig. 1;

3 is an isometric view obliquely from below of the common rail according to FIGS. 1 and 2 without a protective cover;

4 the common rail according to FIGS. 1 to 3 with

Protective cover in a longitudinal section along the longitudinal median plane;

5 the common rail according to FIGS. 1 to 4 without

Protective cover in a cut parallel to the

^' Longitudinal median plane through a first

Series of connections, which includes the high pressure inlet and six high pressure outlets; and

6 the common rail according to FIGS. 1 to 5 in one

Section along the line VI - VI of Fig. 4th In the following description of the figures and in all the figures, the same reference symbols are used for the same features.

1 shows a device for the intermittent injection of high-pressure fuel into the combustion chambers of an internal combustion engine 10. In the exemplary embodiment shown, the internal combustion engine 10 is a 12-cylinder V internal combustion engine with two cylinder banks, each having six cylinders.

A high-pressure feed pump 14 and a common rail 16 according to the invention are fastened to the structure 12 of the internal combustion engine 10, in the exemplary embodiment shown between the two cylinder banks. The high-pressure feed pump 14, which is driven by the internal combustion engine 10 via a toothed belt or via gearwheels in a known manner, has a low-pressure inlet 18 and a high-pressure outlet 20. With a low-pressure connecting line 22 to the low-pressure inlet 18, the fuel is under low pressure of, for example, 2 to 10 bar, the high-pressure feed pump 14 brings the pressure to, for example, approximately 2000 bar in a known manner, and the common with a high-pressure outlet line 24 connected to the high-pressure outlet 20 Rail 16 fed.

The common rail 16 has an approximately cuboid rail body 26, preferably made of high-strength steel, in which a high-pressure storage space 28 is present, as shown in FIGS. 5 and 6. With the high-pressure storage space 28 is a high pressure inlet 30 to which the high pressure feed line 24 is connected and the high pressure outlets 32 are connected. In the shown

In the exemplary embodiment, each of the twelve high-pressure outlets 32 is connected via a high-pressure connecting line 34 to an associated injection valve 36 in order to supply the fuel with the high-pressure fuel.

For the sake of clarity, only those six injection valves 36 are shown in FIG. 1 which are assigned to the six cylinders of the one cylinder bank, in order to inject fuel under high pressure intermittently into their cylinders. The six injection valves 36 assigned to the second cylinder bank are connected in the same way to the remaining high-pressure outlets 32.

The rail body 26 also has one

Low pressure feed inlet 38 and one

Low pressure feed outlet 40. The low-pressure connection line 22 is connected to the latter. Connected to the low-pressure feed inlet 38. Is a low-pressure feed line 42 - indicated schematically in FIG. 2, through which the fuel under low pressure is supplied from a fuel tank, for example by means of a low-pressure fuel feed pump. As can be seen in particular from FIGS. 1 and 2, the rail body 26 in the exemplary embodiment shown has a flat connection surface 44 on the upper side, on the side and in the region of which all hydraulic connections of the common rail 16, that is to say the high-pressure inlet 30, the high pressure outlets 32, the Low pressure feed inlet 38, low pressure feed outlet 40 and, as will be described below, a return outlet 46 are formed.

2, the high-pressure inlet 30 and the six high-pressure outlets 32 assigned to the aforementioned cylinder bank are arranged one behind the other in a straight first connection row 48, the first connection row 48 in a longitudinal direction L defined by the rectangular rail body 26 parallel to the longitudinal center plane E and laterally offset with respect to this. The longitudinal center plane E continues at right angles to the connection surface 44.

The low pressure feed inlet 38, the

Low-pressure feed outlet 40 and the return outlet 46 are arranged one behind the other in a linear second connection row 50 in the longitudinal direction L, the second connection row 50 in the exemplary embodiment shown extending along the longitudinal center plane E.

The remaining six high-pressure outlets 32 assigned to the other cylinder bank are arranged one behind the other in a linear third connection row 52 in the longitudinal direction L. The third connection row 52 extends symmetrically with respect to the longitudinal center plane E to the first connection row 48, one of the high-pressure outlets 32 being located symmetrically to the high-pressure inlet 30.

The common rail 16, as can be seen in particular from FIGS. 1, 2 and 4, is assigned a protective cover 54 on which the rail body 26 is arranged and which with its bottom cover wall 56 rests on the structure 12 of the internal combustion engine 10. The protective cover 54 and the rail body 26 are fastened to one another by means of screws. The rail body 26 is detachably fastened to the structure 12 of the internal combustion engine 10 with four screws 58, which run through corresponding passages in the rail body 26 and in the casing 60 of the protective cover 54. For the sake of completeness, it should be mentioned that the protective cover 54 is connected to the casing 60 continuously on the circumferential side and thus has a cap-like shape.

The rail body 26 has a flat control surface 62 on its lower side facing away from the connection surface 44 and parallel to this (see also FIGS. 3 and 4), which is covered by the protective cover 54.

The connection surface and the control surface 62 are parallel to the longitudinal direction L.

Arranged on the control surface 62 is a fuel quantity control valve 64 which, in the exemplary embodiment shown, is formed by a generally known, electrically controlled suction throttle valve 66, as can be seen in particular from FIGS. 3 and 4. The fuel quantity control valve 64 arranged on the rail body 26 is connected between the low-pressure feed inlet 38 and the low-pressure feed outlet 40 and serves to regulate the fuel quantity sucked in by the high-pressure feed pump 14 or supplied to it. Furthermore, two pressure sensors 68 are arranged and fastened to the rail body 26, on the control surface 62, which serve to measure the pressure of the fuel in the high-pressure storage space 28 of the common rail 16; Of course, it is also possible to provide only a single pressure sensor 68.

Furthermore, in the embodiment shown, an electrically controlled pressure control valve 70 and a mechanical pressure relief valve 72 are arranged on the rail body 26, on the control surface 62 thereof.

The pressure control valve 70 and the pressure relief valve 72 are connected between the high pressure storage space 28 and the return flow outlet 46.

A return line 124 is connected to the return outlet 46 and returns the fuel emerging from the high-pressure storage space 28 when the pressure control valve 70 or pressure relief valve 72 is open to the fuel tank.

The pressure control valve 70 is provided to rapidly lower the pressure in the high-pressure storage chamber 28 and thus also in the injection valves 36 when the power demanded by the internal combustion engine 10 drops rapidly.

Under normal operating conditions, the preferably mechanically designed pressure relief valve 72 is closed. It opens when a maximum pressure value is exceeded in the high-pressure storage space 28 and closes again when the pressure falls below a predetermined pressure. The fuel quantity control valve 64, the pressure sensors 68, the pressure control valve 70 and the pressure relief valve 72 are arranged one behind the other in a linear control row 74 in the longitudinal direction L, the control row 74 being located in the longitudinal center plane E.

The control elements 76, that is to say in the exemplary embodiment shown, the fuel quantity control valve 64 and the pressure control valve 70, the measuring elements 78, in the exemplary embodiment shown the pressure sensors 68, and the safety elements 80 in the shown

Embodiment, the pressure relief valve 72, are arranged on the control surface 62 of the rail body 26 and fastened to it and encapsulated by the protective cover 54 protected from the environment. The electrical components of the control elements 76 - in the exemplary embodiment shown this

Fuel quantity control valve 64 and the pressure control valve 70 - and the measuring elements 78 - in the shown

In the exemplary embodiment, the pressure sensors 68 are connected via electrical lines 82 to a plug socket 84 which extends through the jacket 60 of the protective cover 54. The plug socket 84 can be connected to an electrical control 86 by means of a control cable in order to control and monitor the device for the intermittent injection of fuel under high pressure into the combustion chambers of the internal combustion engine 10. For the sake of completeness, it should be mentioned that, if necessary, electrical components of the safety elements 80 can also be connected to the controller 86 in the same way. The low-pressure connections of the common rail 16, that is to say the low-pressure feed inlet 38, the

Low-pressure feed outlet 40 and the return outlet 46 are of identical design, as is shown in particular in FIG. 4. They each have a blind bore 88, starting from the connection surface 24 and running at right angles to this, with a conical bottom region and with an internal thread. In the internal thread are the connecting screws of the low-pressure connection line 22 in a known manner

Low-pressure feed line 42 and the return line 124 can be screwed in. However, it is also possible to design these low-pressure connections differently.

In contrast, all high-pressure connections, in the exemplary embodiment shown the high-pressure inlet 30 and the high-pressure outlets 32, on the connection surface 44 and at right angles to this protruding cylinder stubs 90 are identical, the cylinder stubs 90 being provided with an external thread; see, in particular, FIGS. 1, 2, 4 and 5. The connection nuts of the high-pressure feed line 24 and the are in a known manner on the external thread

High-pressure connecting lines 34 can be screwed on.

As an alternative to the threaded stubs 90, the rail body 26 could also be used for the high-pressure connections, here 30 and 32

High-pressure suitable internal thread connections, similar to those disclosed in connection with the low pressure connections, here 38, 40 and 46. It can then be pro

High-pressure connection, a high-pressure connection nipple can be provided, which is screwed in in a known manner with injectors and with common rails and each according to the Rail embodiment, can also be welded soapy as is known.

From the bottom region of the blind hole 88 of the low-pressure feed inlet 38 runs to the bottom region of a blind hole-like receiving bore 94 for the

Fuel quantity control valve 64 an inclined bore 92; see FIGS. 4 and 6. The receiving bore 94 extends from the control surface 62 and is perpendicular to it. Furthermore, an in runs from the first end face 96 of the rail body 26 facing the high-pressure feed pump 14

First longitudinal bore 98 extending in the longitudinal direction L up to the receiving bore 94. The first longitudinal bore 98 is closed at the first end face 96 by means of a sealing element 126. A connecting bore 100 extends further into the first longitudinal bore 98 from the bottom region of the blind bore 88 of the low-pressure feed outlet 40. The oblique bore 92, the first longitudinal bore 98 and the connecting bore 100 form a connecting line between the low-pressure feed inlet 38 and the

Low pressure feed outlet 40, in which the

Fuel quantity control valve 64 is switched.

At this point it should be mentioned that it is also possible, if the common rail 16 is otherwise of the same design, the fuel quantity control valve 64, as in the prior art

Technology to assign the high pressure feed pump 14.

It goes without saying that in this case no low-pressure feed inlet 38, no low-pressure feed outlet 40 and no connecting line connecting them to one another would be necessary on the rail body 26. Axially parallel to the first longitudinal bore 98, a second longitudinal bore 102 runs from the second end face 96 ′ of the rail body 26 facing away from the first end face 96, said second longitudinal bore 102 extending into a further one from the bottom region of the blind hole bore 88 assigned to the return outlet 46

Connection bore 104 opens and ends there; see Fig. 4. The second longitudinal bore 102 is closed at the end face 96 'by means of a sealing element 126'.

The second longitudinal bore 102 is crossed by further receiving bores 106 for the pressure control valve 70 and the pressure relief valve 72. These blind hole-like further receiving bores 106 run from the

Control surface 62 and perpendicular to this.

From the bottoms of the further receiving bores 106 for the pressure control valve 70 and the pressure relief valve 72, bores also run at right angles to the control surface 62, each of which opens into a transverse bore 108, these transverse bores 108 running at right angles to the longitudinal center plane E each providing a flow connection to the high-pressure storage space 28 or its further represent holes 114 described below; see Figs. 5 and 6.

Opens the pressure relief valve 72 inserted into the relevant receiving bore, flows through the associated transverse bore 108 from the high-pressure storage space 28, fuel which flows through the second longitudinal bore 102 - am

Pressure control valve 70 over - and the further connection bore 104 is directed to the reflux outlet 46. Correspondingly, the fuel emerging from the high-pressure storage chamber 28 through the associated transverse bore 108 when the pressure control valve 70 is open is also fed to the return flow outlet 46 through the second longitudinal bore 102 and the further connecting bore 104.

Further extend from the control surface 62 and at right angles to this blind hole-like pressure sensor

Receiving bores 110. From the bottoms of the two pressure sensor receiving bores 110, bores each run to a further transverse bore 112, which each establish a hydraulic connection to the high-pressure storage space 28 or the associated bore 114. As shown in particular in FIGS. 2, 3 and 6, the transverse bores 108 and further transverse bores 112 are likewise closed off from the environment by means of sealing screws.

5 and 6 in connection with FIGS. 2 and 3, the high-pressure storage space 28 has the two bores 114 which run in the longitudinal direction L from the first end face 96 to the second end face 96 'and at these two end faces 96 , 96 'by means of

Screw plugs 116 are tightly closed. The

Axes of the two bores 114 run in the planes running parallel to the longitudinal center plane E, in which the first and third row of connections 48, 52 are also located.

5 and 6 show, the two bores 114 are connected to one another via the further transverse bores 108, the one in FIG. 6 also being connected to the side surface of the Rail body 26 extending and there closed portion of these further transverse bores 108 is visible.

From the free ends of the cylinder stub 90, blind-hole-like connection bores 120 extend, the conical bottom surface of which forms a sealing surface which mates with corresponding sealing surfaces of the high-pressure feed line 24 or high-pressure connecting lines 34

Interact. From the bottom of each connection bore 120, a connection connection bore 122 runs at right angles to the connection surface 44 and opens into the associated bore 114.

For the sake of completeness, it should be mentioned that the two bores 114, which form a large proportion of the high-pressure storage space 28, are larger in diameter than the other bores mentioned, which represent hydraulic connections.

In the exemplary embodiment shown, the rail body 26 is machined from a single metal block. The cuboidal embodiment of the rail body 26 allows the high-pressure storage chamber 28 and the necessary hydraulic connections to be produced in a simple manner by means of bores running in particular in the longitudinal direction L and at right angles to the connecting surface 44 or control surface 62 and the side surfaces. The two bores 114 can also be designed as blind bores, so that they can only be closed with a screw plug 116 on the end face 96 or 96 'from which they originate.

Claims

Common rail for a device for the intermittent injection of high-pressure fuel into combustion chambers of an internal combustion engine (10), the device comprising a high-pressure feed pump (14) for fuel, comprising a low-pressure inlet (18) and a high-pressure outlet (20), and injection valves (36) having a rail body (26) which has a high pressure storage space (28), a high pressure inlet (30) connected to the high pressure storage space (28) and high pressure outlets (32) connected to the high pressure storage space (28), the high pressure inlet (30) being used for this purpose is to be connected to the high pressure outlet (20) of the high pressure feed pump (14) and the high pressure outlets (32) are intended to be connected to injection valves (36), characterized by a fuel quantity control valve (64) arranged on the rail body (26) Regulation of the amount of fuel drawn in by the high-pressure feed pump (14), which is between a never the pressure feed inlet (38) of the rail body (26) and a low pressure feed outlet (40) of the rail body (26) is connected, the low pressure feed inlet (38) being intended to be connected to a low pressure fuel supply line (42), and the Low pressure feed outlet (40) is intended to be connected to the low pressure inlet (18) of the high pressure feed pump (14).

2 Common Rail according to claim 1, characterized by a on the rail body (26) arranged pressure sensor (68) for measuring the pressure of the fuel in the high pressure storage space (28).

3 Common Rail according to claim 1 or 2, characterized by a pressure control valve (70) arranged on the rail body (26) and / or a pressure relief valve (72) arranged on the rail body (26), the pressure control valve (70) and / or the pressure relief valve (72 ) is or are connected between the high-pressure storage space (28) and a return outlet (46) of the rail body (26). 4 Common rail according to one of claims 1 to 3, characterized in that the rail body (26) has an at least approximately flat control surface (62) on which the fuel quantity control valve (64) is arranged and on which the pressure sensor (68), if applicable Pressure control valve (70) and the pressure relief valve (72) are arranged.

5 Common Rail according to one of claims 1 to 4, characterized in that the rail body (26) has an at least approximately flat connection surface (44), the low pressure feed inlet (38), the low pressure feed outlet (40), the high pressure inlet (30) and the High-pressure outlets (32) and optionally the return outlet (46) are arranged on the side of the connection surface (44).

6. Common rail according to claim 4 and 5, characterized in that the rail body (26) is at least approximately cuboid, the control surface (62) and the connecting surface (44) facing away from one another at least approximately parallel to one another.

7. Common rail according to claim 6, characterized in that the rail body (26) defines a longitudinal direction (L), the high pressure inlet (30) and high pressure outlets (32) in a first connection row

(48) are arranged one behind the other in the longitudinal direction (L) and the low-pressure feed inlet (38) and the low-pressure feed outlet (40) and optionally the return outlet (46) are arranged one behind the other in a second connection row (50) in the longitudinal direction (L).

8. Common rail according to claim 7, characterized in that the fuel quantity control valve (64) and optionally the pressure sensor (68), the pressure control valve (70) and the pressure relief valve (72) are arranged one behind the other in a control row (74) in the longitudinal direction (L) .

9. Common rail according to claim 7 or 8, characterized in that the high-pressure storage space (28) through a in the longitudinal direction (L) in the rail body (26) extending at one end or at both ends by means of a closure (116) closed bore (114 ) and by leading from the high pressure inlet (30) and from the high pressure outlets (32) to the bore (114), smaller in cross section

Connection holes (122) is limited.

10. Common rail according to one of claims 1 to 9, characterized by a on the rail body (26) arranged protective cover (54) which the control surface (62), the fuel quantity control valve (64) and optionally the pressure sensor (68), the

Pressure control valve (70) and the pressure relief valve (72) surrounds the environment.

11. Common rail according to claim 10, characterized in that an electrical connector (84) is arranged on the protective cover (54), with which the fuel quantity control valve (64) and optionally the pressure sensor (68) and the pressure control valve (70) is electrically connected or are.

12. Common rail according to one of claims 1 to 11, characterized in that the

Fuel flow control valve (64)

Has suction throttle valve (66).

13. Common rail for a device for the intermittent injection of high-pressure fuel into combustion chambers

Internal combustion engine (10), the device having a high-pressure feed pump (14) for fuel, comprising a low-pressure inlet (18) and a high-pressure outlet (20), and injection valves (36), with a rail body (26) defining a longitudinal direction (L), which one

High-pressure storage space (28), one connected to the high-pressure storage space (28)

High pressure inlet (30) and connected to the high pressure storage space (28)

High pressure outlets (32), wherein the High-pressure inlet (30) is designed to be connected to a high-pressure outlet (20) of the high-pressure delivery pump (14), and the high-pressure outlets (32) are designed to be connected to injection valves (36), characterized in that the rail body (26 ) has an at least approximately flat control surface (62) running at least approximately parallel to the longitudinal direction (L), on which at least one control element (76), such as a fuel quantity control valve (64) for regulating the fuel quantity sucked in by the high-pressure feed pump (14) and / or a pressure control valve (70), and / or a measuring element (78), such as a pressure sensor (68) for measuring the pressure of the fuel in the high pressure storage space (28), and / or a safety element (80), such as a pressure relief valve (72) is or are, and the rail body (26) has an at least approximately flat, at least approximately flat connection surface (44) running parallel to the longitudinal direction (L), wherein the high pressure inlet (30) and the high pressure outlets (32) are arranged on the side of the connection surface (44).

14. Common rail according to claim 13, characterized in that the rail body (26) is at least approximately cuboid, the control surface (62) and the connection surface (44) facing away from one another at least approximately parallel to one another. 15. Common rail according to claim 13 or 14, characterized by a on the rail body (26) arranged protective cover (54) which the control surface (62) Control element (76) and optionally the measuring element (78) and the security element (80) to protect against the environment.

16. Common rail according to claim 15, characterized in that an electrical on the protective cover (54)

Plug socket (84) is arranged, with which the control element (76) and optionally the measuring element (78) is or are electrically connected. 17. Common rail according to claim 13 to 16, characterized in that the high-pressure storage space (28) through a in the longitudinal direction (L) in the rail body (26) extending at one end or at both ends by means of a closure (116) closed bore (114 ) and by leading from the high pressure inlet (30) and from the high pressure outlets (32) to the bore (114), smaller in cross section

Connection holes (122) is limited.