WO2022223716A1

WO2022223716A1 - Pressure control valve for adjusting the pressure of a fuel, in particular for controlling the pressure of a fuel, and fuel system for an internal combustion engine

Info

Publication number: WO2022223716A1
Application number: PCT/EP2022/060596
Authority: WO
Inventors: Dirk Reinhold Dietzel; Christoph Espey; Felix Lippert; Sven POETZL
Original assignee: Daimler Truck AG
Priority date: 2021-04-22
Filing date: 2022-04-21
Publication date: 2022-10-27
Also published as: DE102021002128B3

Abstract

The invention relates to a pressure control valve (30) for adjusting the pressure of a fuel in a fuel system (10), through which fuel can flow, for an internal combustion engine, comprising a first connection (32), via which the fuel can be introduced into the pressure control valve (30); a second connection (36), via which the fuel introduced into the pressure control valve (30) via the first connection (32) can be discharged from the pressure control valve (30); a valve element (40), which can be moved between at least one closed position (S) and at least one open position (O); and a first control connection (42), via which a first fuel pressure, and thus a force (F1) resulting from the pressure, can be applied to the valve element (40), said valve element (40) being movable from the closed position (S) into the open position (O) by means of said force. (Fig. 2)

Description

Pressure control valve for adjusting, in particular controlling, a fuel pressure and fuel system for an internal combustion engine

The invention relates to a pressure control valve for setting, in particular regulating, a fuel pressure in a fuel system for an internal combustion engine through which the fuel can flow. The invention also relates to a fuel system for delivering fuel for an internal combustion engine.

EP 2441 946 B1 discloses a fuel pressure regulator having a bore in which is located a valve element which is movable from a non-regulating position of the fuel regulator, in which a first end of the bore is closed, to a regulating position of the fuel pressure regulator, in which the first end of the bore is open. Furthermore, a fuel pressure control system is known from EP 2 159406 A1.

The object of the present invention is to create a pressure control valve for setting a pressure of a fuel in a fuel system through which the fuel can flow, and a fuel system, so that the pressure of the fuel can be set in a particularly simple and advantageous manner.

This object is achieved by a pressure control valve having the features of patent claim 1 and by a fuel system having the features of patent claim 10 . Advantageous configurations with expedient developments of the invention are specified in the remaining claims.

A first aspect of the invention relates to a pressure control valve for setting, in particular controlling, a pressure of a fuel, in particular a liquid fuel, in one of the Fuel system for an internal combustion engine, in particular a motor vehicle, through which fuel can flow and is also referred to as a fuel device or fuel device or is designed as a device and preferably includes the pressure control valve. This means that the motor vehicle, which is preferably designed as a motor vehicle, has the internal combustion engine in its fully manufactured state and can be driven by the internal combustion engine. In addition, the motor vehicle includes the fuel system, by means of which the fuel, in particular of the internal combustion engine, can be delivered. For example, the fuel system is or includes a fuel circuit through which the fuel can flow.

The internal combustion engine is designed, for example, as a reciprocating engine or as a reciprocating engine. The fuel system includes, for example, a high-pressure pump, also referred to as a high-pressure fuel pump, and a pre-supply pump, also referred to as a fuel pre-supply pump, which is arranged in a fuel path through which the fuel can flow. For example, the fuel path comprises a line through which the fuel can flow, or the fuel path is formed by a line through which the fuel can flow. The line is also known as the fuel line. The fuel can be conveyed from a reservoir through the fuel path by means of the pre-supply pump and thereby conveyed to the high-pressure pump. The reservoir is also referred to as a tank or fuel tank, or the reservoir is a fuel tank, also referred to as a tank, the fuel being or being received in the reservoir. In the direction of flow of the fuel flowing through the fuel path, the pre-supply pump is preferably arranged downstream of the reservoir, so that the pre-supply pump draws in the fuel from the reservoir and can thereby convey it in particular through a first part of the fuel path and thus, for example, can convey it towards itself. In addition, the pre-supply pump can pump the fuel away from itself and thereby, for example, through a second part of the fuel path, with the high-pressure pump being arranged downstream of the pre-supply pump, in particular downstream of the fuel path, in the flow direction of the fuel flowing through the fuel path. This means in particular that the presupply pump can first deliver the fuel from the reservoir towards itself and then away from it and thereby deliver it through the fuel path and can deliver it to the high-pressure pump. In particular, the fuel can be conveyed through the fuel path at a first fuel pressure by means of the pre-supply pump and can thus be conveyed to the high-pressure pump. In other words can by means of the pre-supply pump, the first fuel pressure of the fuel can be effected. This also means that the high-pressure pump can be supplied from the reservoir via the pre-supply pump with the fuel that is delivered by means of the pre-supply pump and in particular that has the first fuel pressure.

Using the high-pressure pump, the fuel delivered by the pre-supply pump to the high-pressure fuel pump, with which the high-pressure pump can be or is being supplied by means of the pre-supply pump, can be transported away from the high-pressure pump and thereby, for example, to at least one injector and/or a fuel distribution element also referred to as a rail or common rail to be promoted. In particular, the high-pressure pump can be used to pump the fuel conveyed by the presupply pump to the high-pressure fuel pump at a second fuel pressure that is greater than the first fuel pressure away from the high-pressure pump and, for example, to the fuel distribution element or to the injector. In other words, the second fuel pressure of the fuel, which is greater than the first fuel pressure and prevails downstream of the high-pressure fuel pump, can be brought about by means of the high-pressure pump.

It can thus be seen that, for example, as part of a method for operating the fuel system, the fuel is sucked in from the reservoir at a third fuel pressure by means of the pre-supply pump and conveyed through the fuel path and towards the high-pressure pump, whereby the high-pressure pump is fed with the Presupply pump funded fuel is supplied. In this case, the aforementioned first fuel pressure of the fuel is effected by means of the pre-supply pump, so that in the method the high-pressure pump is supplied with the fuel having the first fuel pressure. The high-pressure pump conveys the fuel, which is conveyed to the high-pressure pump by means of the pre-supply pump, away from itself and in the process, for example, to the injector or to the fuel distribution element, with the high-pressure pump causing the second fuel, which is greater than the first fuel pressure.

It is conceivable that the fuel system includes the at least one injector and/or the fuel distribution element. In particular, the following can be provided: The internal combustion engine can have a plurality of combustion chambers, with a first of the combustion chambers being assigned the at least one injector, and with a second of the combustion chambers being assigned a second injector. through the injectors the fuel can be introduced into the combustion chambers, in particular injected directly into the combustion chambers. The fuel distribution element is a fuel distribution element that is common to the injectors and via which the injectors can be or are supplied with fuel. The high-pressure pump delivers, for example, the fuel at the second fuel pressure to and into the fuel distribution element, in which the fuel at the second fuel pressure is received. The injectors can be supplied with the fuel having the second fuel pressure from the fuel distribution element, so that the respective injector can eject the fuel having the second fuel pressure and thereby bring it into the respectively associated combustion chamber, in particular inject it directly.

The fuel system also includes the aforementioned pressure control valve, by means of which the aforementioned pressure of the fuel can be adjusted, in particular regulated. The fuel pressure adjustable by means of the pressure control valve is, for example, a fuel pressure in the fuel path and thus a fuel pressure prevailing in the fuel path upstream of the high-pressure pump and preferably downstream of the presupply pump. In particular, the pressure of the fuel that can be set, in particular that can be controlled, by means of the pressure control valve can be the first fuel pressure. The pressure that can be set, in particular regulated, by means of the pressure control valve is also referred to as the setting or control pressure, since it is set, in particular regulated, by means of the pressure control valve.

For this purpose, the pressure control valve has a first connection via which the fuel, i.e. at least part of the fuel, in particular from the fuel path from a branch point of the fuel path arranged downstream of the presupply pump and upstream of the high-pressure pump, can be introduced into the pressure control valve. For this purpose, it is preferably provided that the first connection at the branching point is fluidically connected or can be connected to the fuel path. Thus, at least part of the fuel flowing through the fuel path can be branched off from the fuel path at the branching point and introduced into the pressure control valve via the first connection. The pressure control valve also has a second port and a valve element. The valve element can be moved, in particular translationally, between at least one closed position and at least one open position, in particular along a direction of movement. The fuel introduced or flown into the pressure control valve via the first connection can be discharged from the pressure control valve via the second connection and in particular at an upstream location the pre-supply pump and preferably downstream of the reservoir arranged introduction point of the fuel path can be introduced into the fuel path. For this purpose, for example, the second connection at the point of introduction is fluidly connected or can be connected to the fuel path.

In particular, it is conceivable that the first connection and the second connection are more fluidly connected to one another in the open position than in the closed position. This means in particular the following: The valve element is, for example, at least partially, in particular at least predominantly and thus at least more than half or completely, accommodated in a valve housing, also referred to simply as a housing, and in particular along the direction of movement relative to the valve housing between the Open position and the closed position, in particular translatory, movable. It is conceivable that in the closed position the valve element, in particular in relation to the valve housing, has such a targeted play that in the closed position between the valve housing and the valve element, for example, such a targeted leakage is provided, caused or realized that via this targeted provided leakage in the closed position, the first port is fluidly connected to the second port, so that for example a quantity of fuel can flow in the closed position of the valve element from the first port to the second port. It is thus conceivable that the first connection and the second connection are not completely fluidically separated from one another in the closed position, but rather are fluidically connected to one another via the specifically provided leakage, ie are in fluidic communication with one another. In the open position of the valve element, however, the first connection and the second connection are more fluidly connected to one another than in the closed position of the valve element, so that, for example, at the same pressure and preferably at the same temperature of the fuel in the open position of the valve element, a larger volume flow from the first Port can flow to the second port than in the closed position. In other words, if, for example, the fuel has a first fluid pressure and a first temperature at or in the first connection while the valve element is in the closed position, a first volume flow of the fuel can flow from the flow from the first port to the second port. For example, if the fuel has the first fluid pressure and the first temperature at or in the first connection while the valve element is in its open position, a second volume flow of the Fuel flow from the first port to the second port. This can be achieved, for example, by the fact that in the closed position of the valve element the smallest flow cross section through which the fuel can flow of a flow path, via which or along which the fuel can flow from the first connection to the second connection, is smaller than in the open position of the valve element . It is particularly conceivable that in the closed position of the valve element the smallest flow cross-section of the flow path through which the fuel can flow is defined or realized or effected by the specifically provided clearance described above. In other words, when the valve element is in the open position, the smallest flow cross section through which the fuel can flow is greater than in the closed position.

For example, a circuit through which the fuel can flow is provided, which extends from the inlet point via the presupply pump to the branch point, from the branch point to the first port, from the first port through the pressure control valve to the second port and from the second port to the Discharge point extends. It is thus particularly conceivable that the flow path mentioned above is part of the circuit mentioned. Since the flow path is more open in the open position of the valve element than in the closed position, the circuit is more open in the open position than in the closed position of the valve element. Thus, in particular when the valve element is in the open position, at least part of the fuel flowing through the fuel path can flow through the circuit and thus flow back from the inlet point via the presupply pump and to the branch point and from there via the first connection, the second connection and the pressure control valve back to the inlet point , therefore circulate, so that the first fuel pressure can be lowered, whereby the pressure of the fuel flowing into the high-pressure pump, and therefore the first fuel pressure, can be regulated precisely, in particular to a maximum value.

The pressure control valve also has a control port, which is also referred to as the first control port. Via the first control connection, the valve element can be acted upon with a first pressure of the fuel prevailing in the fuel path, in particular at a control point of the fuel path located downstream of the branching point to the first connection of the pressure control valve and upstream of the high-pressure pump. The first pressure of the fuel is also referred to as the first application pressure and can be a first fuel pressure or previously be mentioned, first fuel pressure. By applying the first application pressure to the valve element, the valve element can be subjected to a first force resulting from the first application pressure, by means of which the valve element can be moved from the closed position into the open position. For this purpose, for example, the first control connection is or can be connected fluidically to the first control point or the first control connection is or can be connected fluidly to the fuel path at the first control point. The fuel or at least part of the fuel can be routed from the first control point to and in particular into the pressure control valve, in particular in such a way that the valve element can be acted upon or is acted upon, in particular directly, via the first control connection with the fuel which is at the first Control point from the fuel path to and into the pressure control valve. As a result, the valve element is subjected to the first application pressure that the fuel has at the first control point. In other words, due to the preferably provided fluidic connection between the first control connection and the first control point, the valve element is subjected to the first application pressure prevailing at the first control point. The first pressure acting at least indirectly, in particular directly, on the valve element results in the aforementioned first force, which acts at least indirectly, in particular directly, on the valve element, which can be moved from the closed position into the open position by means of the first force. This can be understood in particular as follows: The valve element can be moved, for example, in a first valve element direction from the closed position to the open position, with the first force resulting from the first application pressure, i.e. at least one force component of the first force, acting in the first valve element direction. The first valve element direction runs, for example, parallel to the aforementioned direction of movement or coincides with the direction of movement.

In order to be able to set, in particular regulate, the setting or control pressure of the fuel in a particularly advantageous and therefore particularly simple manner, it is provided according to the invention that the pressure control valve has a second control connection. Via the second control connection, the valve element can be acted upon, in particular at least indirectly or preferably directly, by a fourth fuel pressure, in particular prevailing in a return path of the fuel system, the fourth fuel pressure also being referred to as the second actuation pressure. By applying the valve element with the second application pressure (fourth fuel pressure), the valve element with a from the The second force resulting from the second application pressure (fourth fuel pressure) and directed in the opposite direction to the first force can be applied at least indirectly, in particular directly, by means of which the valve element can be moved from the open position into the closed position. For this purpose, the second control port can preferably be fluidically connected or connected to the return path at a second control point of the return path, so that the second application pressure (fourth fuel pressure) prevailing in the return path can be introduced into the pressure control valve, also simply referred to as the control valve, in particular in such a way that the Valve element can be or is acted upon at least indirectly, in particular directly, by the fourth fuel pressure introduced into the pressure control valve via the second control port. Due to the preferably provided fluidic connection between the second control connection and the return path, the fuel with which the valve element is acted upon via the second control connection has the fourth fuel pressure (second application pressure) that the fuel has at the second control point in the return path. The aforementioned second force, which is directed in the opposite direction to the first force, results from the fourth fuel pressure acting at least indirectly, in particular directly, on the valve element. This is to be understood in particular as follows: The valve element can be moved, for example, in a second valve element direction opposite to the first valve element direction, from the open position into the closed position. The second valve element direction runs, for example, parallel to the aforementioned direction of movement or coincides with the direction of movement. In this case, the second force, that is to say at least one force component of the second force, acts in the second valve element direction.

Furthermore, it is provided according to the invention that in the closed position at least the second connection is fluidically separated from the first control connection. Below this, for example, it is provided that a valve seat formed in particular by the valve housing or provided on the valve housing, on which the valve element bears or sits sealingly, for example in the closed position, is arranged between the first control connection and the second connection. Thus, for example, no fuel can flow from the first control port to the second port. In particular, the feature that in the closed position the first control connection is fluidically separated from the second connection by means of the valve element means that no specifically provided fluidic connection and thus also no specifically provided leakage between the first control connection and the second connection in the closed position is provided. Because in the open position second port is fluidically connected to the first control port, fuel can flow from the first control port to the second port, for example in the open position. Thus, it is particularly conceivable that a connection path is provided, along which or via which fuel can flow from the first control port to the second port. In the closed position, the connection path is closed or interrupted by the valve element, so that no fuel can flow through the connection path in the closed position, and consequently no fuel can flow from the first control port to the second port. In the open position, however, the valve element releases the connection path, so that fuel can flow from the first control port to the second port in the open position. This can be provided in particular in such a way that in the open position a specifically provided gap or a specifically provided second leakage is formed between the valve element and the housing, with fuel flowing through this gap or through this specifically provided second leakage and thus from the first control port can flow to the second port.

The return path is to be understood as meaning that at least an excess part of the fuel, delivered at least by means of the presupply pump and possibly also by means of the high-pressure pump to a component of the fuel system, is to be routed or is routed back from the component to the reservoir via the return path. In other words, during the aforementioned method, for example, the component is supplied with the fuel delivered at least by means of the pre-supply pump and preferably also by means of the high-pressure pump. In particular, it can be provided that the fuel, which is delivered to the component or with which the component is supplied, is delivered by means of the presupply pump at the first fuel pressure to the high-pressure pump and by means of the high-pressure pump to the component at the second fuel pressure. At least an excess part of the fuel, which was conveyed to the component by the high-pressure pump, is diverted, for example, and, in particular unused and in particular unburned, is fed back from the component to the reservoir via the return path. The excess part of the fuel thus flows on its way from the component to and into the reservoir through the return path, with which the second control port can be or is fluidically connected, in such a way that the valve element with the fourth fuel pressure prevailing in the return path (second Actuation pressure) can be acted upon at least indirectly, in particular directly. The component is, for example, the fuel distribution element, from which the excess part of the fuel is diverted, in particular via a further pressure control valve assigned to the fuel distribution element, by means of which the second fuel pressure prevailing in the fuel distribution element can be adjusted, in particular regulated. The second fuel pressure can be set, in particular regulated, for example via a quantity metering unit at an inlet of the high-pressure pump. Furthermore, the component can be the respective injector or injectors. Furthermore, the component can be the high-pressure pump, or the component can be a fuel filter, which can be arranged, for example, in the fuel path and, for example, downstream of the pre-supply pump and upstream of the high-pressure pump, so that the fuel filter can be filtered by means of the fuel filter fuel flowing through and, for example, the fuel path is to be filtered.

It can be seen that the first application pressure, in particular the first fuel pressure, upstream of the high-pressure pump is used as a first control or regulation pressure and the fourth fuel pressure (second application pressure), in particular in the return path, is used as a second control or regulation pressure in order to To move the valve element into the closed position and into the open position or to hold it in the closed position and in the open position. In other words, depending on the ratio of the control pressures, the valve element remains in the closed position or in the open position, or the valve element is moved from the closed position to the open position or from the open position to the closed position, as a result of which the set pressure (in particular the first fuel pressure) is particularly adjusted, in particular regulated, in a simple and advantageous manner.

Since at least the excess fuel can flow from the component back into the reservoir via the return path, the fuel system is or includes, for example, a fuel circuit through which the fuel can flow, in or in which the first fuel pressure can be set, in particular regulated, particularly easily and advantageously . The return path is formed, for example, by at least one return line or comprises at least one return line, wherein the fuel can flow or flows through the return line on its way from the component back into the reservoir. In an advantageous embodiment of the invention, in the closed position of the valve element, a targeted leakage of the fuel from the first connection to the second control connection is provided in the pressure control valve, that is to say it is designed or produced. The feature that the leakage is a targeted leakage is to be understood as meaning that the leakage is provided in a targeted manner, that is to say it is designed or produced in a targeted manner. In other words, the leakage is not an undesired, technically caused and unavoidable leakage, but the targeted leakage is specifically designed and enables a fluidic connection of the second control port of the pressure control valve to the return path when the valve element is in its closed position located. Targeted leakage is also referred to as forced leakage. In principle, the leakage can also exist in the open position, but will then be smaller because the inlet in the open position is fluidically connected to the suction side of the presupply pump.

Alternatively or additionally it can be provided that in the closed position and in the open position a targeted leakage of the fuel from the first control connection to the second connection in the pressure control valve is provided, ie is formed or produced. As a result, an advantageous pressure drop from the first control port, which is connected to the first control point downstream of the pre-supply pump and upstream of the high-pressure pump, to the second port, which is connected to the inlet point upstream of the pre-supply pump, can be made possible or used to prevent contamination of a mentioned clean side, on which the first control point is arranged, to avoid, that is, to avoid undesirable contamination, that is, contamination of fuel that has already been filtered, in particular by unfiltered fuel. The avoidance of contamination of already filtered fuel by unfiltered fuel can be implemented by the invention in a particularly simple manner and in particular without additional bores or overflow channels, so that the fuel system according to the invention makes it possible to set the first fuel pressure in a particularly simple and cost-effective manner, in particular to be able to regulate.

A further embodiment is characterized in that the pressure control valve has a valve housing which, for example, has or forms or delimits the first connection, the second connection, the first control connection and the second control connection. The first connection, the second connection, the the first control connection and the second control connection are collectively also referred to as connections.

The valve housing preferably also has a receptacle designed, for example, as a bore and also referred to as a bore. In particular, the intake is limited by the valve housing, in particular directly. The valve element is arranged in the receptacle in such a way that the valve element can be moved translationally along a direction of movement between the closed position and the open position relative to the valve housing. The direction of movement runs parallel to the aforementioned first valve element direction and parallel to the aforementioned second valve element direction, or the valve element direction coincides with the direction of movement. As a result, a particularly simple and therefore cost-effective construction of the pressure control valve can be implemented, so that the first fuel pressure upstream of the high-pressure pump can be adjusted, in particular regulated, in a particularly simple manner.

In order to be able to set, in particular regulate, the first fuel pressure in a particularly advantageous and therefore particularly cost-effective manner, a further embodiment of the invention provides that the receptacle at both ends along the direction of movement is both in the closed position and in the open position, i.e regardless of the open position and regardless of the closed position, is closed. In particular, provision is made for the receptacle to be closed at both of its ends along the direction of movement in all positions in which the valve element can be moved relative to the valve housing along the direction of movement.

A further embodiment is characterized in that the first connection, the second connection, the first control connection and the second control connection open into the receptacle along a respective direction running obliquely or preferably perpendicularly to the direction of movement. As a result, a particularly simple and thus cost-effective construction of the pressure control valve can be ensured.

In a further, particularly advantageous embodiment of the invention, it is provided that the opening point of the second connection, i.e. the opening point at which the second connection opens into the receptacle, is located along the direction of movement between the opening points of the first control connection and the first connection. This allows the first fuel pressure on especially adjusted, in particular regulated, in a simple and advantageous manner. A particularly great advantage of this channel arrangement is a forced flow from filtered to unfiltered fuel.

In order to realize a particularly simple construction of the pressure control valve and thus to be able to set, in particular regulate, the first fuel pressure in a particularly advantageous and simple manner, it is provided in a further embodiment of the invention that the opening point of the first connection along the direction of movement between the opening points of the second Control connection and the second connection is located.

Finally, it has proven to be particularly advantageous if an outlet opening of the first connection, which is arranged at an outlet point of the first connection and which opens out at its outlet point via the outlet opening into the receptacle, at least in the closed position of the valve element along a direction perpendicular to the direction of movement and towards towards the valve member is completely overlapped by the valve member with a second clearance. In this way, for example, an undesired influence on the first fuel pressure, which acts in front of the high-pressure pump, can be avoided by allowing the fuel to flow downstream of the presupply pump via the branching point to the first connection of the pressure control valve with the second clearance between the opening point of the outlet opening of the first connection in the receptacle and overlapping valve element can be adjusted. In particular, a particularly simple and cost-effective design of the valve element can be implemented as a result.

In a further embodiment of the invention, the pressure control valve comprises a spring, in particular a mechanical spring, by means of which a spring force acting at least indirectly, in particular directly, on the valve element in the same direction as the second force and thus preferably in the second valve element direction can be provided, by means of which the Valve element is movable from the open position to the closed position.

During the aforementioned method, for example, a first total force in the first valve element direction acts at least indirectly, in particular directly, on the valve element, the first total force being at least partially, in particular at least predominantly and thus at least more than half or completely, due to the first force can be formed. In addition, for example, a second total force directed counter to the first total force acts in the second valve element direction at least indirectly, in particular directly, on the valve element, the second total force being formed at least partially, in particular at least predominantly, by the second force. Provision is preferably made for the second total force to be formed partly by the second force and partly by the spring force. If the first total force is greater than the second total force, the valve element is moved in the first valve element direction or held in the open position. If the second total force is greater than the first total force, the valve element is moved into the closed position or held in the closed position. As a result, the first fuel pressure can be set, in particular regulated, in a particularly advantageous manner.

A second aspect of the invention relates to a fuel system for delivering fuel for an internal combustion engine, the fuel system having at least one pressure control valve according to the invention according to the first aspect of the invention. Advantages and advantageous configurations of the first aspect of the invention are to be regarded as advantages and advantageous configurations of the second aspect of the invention and vice versa.

A third aspect of the invention relates to a motor vehicle, preferably designed as a motor vehicle, which has an internal combustion engine, by means of which the motor vehicle can be driven. In addition, the motor vehicle has a fuel system according to the first aspect of the invention, the internal combustion engine being able to be supplied with the fuel by means of the fuel system. Advantages and advantageous configurations of the first and second aspect of the invention are to be regarded as advantages and advantageous configurations of the third aspect of the invention and vice versa.

Further advantages, features and details of the invention result from the following description of a preferred exemplary embodiment and from the drawing. The features and combinations of features mentioned above in the description and the features and combinations of features mentioned below in the description of the figures and/or shown alone in the figures can be used not only in the combination specified in each case, but also in other combinations or on their own, without going beyond the scope of the leave invention.

The drawing shows in: 1 shows a schematic representation of a fuel system according to the invention for an internal combustion engine of a motor vehicle;

2 shows a schematic sectional view of a pressure control valve of the fuel system, with a valve element of the pressure control valve being in its closed position; and

3 shows a schematic sectional view of the pressure control valve, the valve element of which is in its open position.

Elements that are the same or have the same function are provided with the same reference symbols in the figures.

1 shows a schematic representation of a fuel system 10 for an internal combustion engine of a motor vehicle, which is not shown in detail. This means that the motor vehicle, which is preferably designed as a motor vehicle, has the internal combustion engine in its fully manufactured state and can be driven by the internal combustion engine. The internal combustion engine has multiple combustion chambers. The respective combustion chamber is assigned, in particular precisely, an injector, by means of which a liquid fuel, in particular, can be introduced, in particular directly injected, into the respective combustion chamber to which the respective injector is assigned. As will be explained in more detail below, the fuel system 10 is used to supply the respective injector with the fuel, in particular liquid fuel. For this purpose, the fuel system 10 has a high-pressure pump 12, also referred to as a high-pressure fuel pump, and a presupply pump 14, which are arranged in a fuel path 16 through which the fuel can flow. The fuel can be pumped from a reservoir 18, embodied as a fuel tank, for example, through the fuel path 16 by means of the pre-supply pump 14 and is thereby pumped towards the high-pressure pump 12, so that the high-pressure pump 12 is downstream of the pre-supply pump in the direction of flow of the fuel flowing through the fuel path 16 and thus through the pre-supply pump 14 14 is arranged. In particular, the high-pressure pump 12 is arranged downstream of the fuel path 16 in the flow direction of the fuel flowing through the fuel path 16 and thus the pre-supply pump 14, so that the fuel path 16 up to the High-pressure pump 12 runs and ends at this. The fuel path 16 is, for example, a low-pressure path, in which the fuel has at least one effected by means of the pre-supply pump 14, first fuel pressure downstream of the pre-supply pump 14. By means of the high-pressure pump 12 , the fuel that is or was being conveyed by the pre-supply pump 14 to the high-pressure pump 12 can be conveyed or conveyed away from the high-pressure pump 12 . The high-pressure pump 12 is arranged, for example, in a second fuel path 20 through which the fuel delivered by the high-pressure pump 12 and thereby delivered away from the high-pressure pump 12 by the high-pressure pump 12 can flow. Thus, for example, the second fuel path 20 is arranged downstream of the fuel path 16 in the flow direction of the fuel flowing through the fuel path 16 and the fuel path 20 .

In particular, the fuel in the fuel path 20 has a second fuel pressure, which is caused by the high-pressure pump 12 and is greater or higher than the first fuel pressure. This means in particular that by means of the pre-supply pump 14, the fuel pressure is promoted with the first fuel and is promoted to the high-pressure pump 12. By means of the high-pressure pump 12 , the fuel is pumped at the second fuel pressure, which is greater than the first fuel pressure, and in particular is pumped away from the high-pressure pump 12 into the second fuel path 20 .

In the second fuel path 20, which is also referred to as the high-pressure path, there is, for example, a fuel distribution element that is common to the injectors and is also referred to as the rail or common rail, to which and into which the fuel, in particular the fuel at the second fuel pressure, is delivered by the high-pressure pump 12 . The injectors can be supplied with the fuel from the fuel distribution element, in particular with the fuel from the fuel distribution element having the second fuel pressure, via the fuel distribution element. Thus, the high-pressure pump 12 can deliver the fuel away from itself and towards the fuel distribution element and via the fuel distribution element to the respective injector with the second fuel pressure.

The fuel system 10 also includes a fuel path 16 arranged in the first fuel filter 22, which is also referred to as a pre-filter. The fuel filter 22 is arranged in the direction of flow of the fuel flowing through the fuel path 16 downstream of the reservoir 18 and upstream of the pre-supply pump 14, so that the means fuel delivered by the pre-supply pump 14 is filtered by means of the fuel filter 22 on its way from the reservoir 18 to the pre-supply pump 14 . The fuel system 10 also includes a second fuel filter 24 which is arranged in the fuel path 16 . The fuel filter 24 is also referred to as a main filter or is a main filter, the fuel filter 24 being arranged downstream of the pre-supply pump 14 and upstream of the high-pressure pump 12 in the flow direction of the fuel flowing through the fuel path 16 . As a result, the fuel that is delivered by means of the pre-supply pump 14 and thus flows through the fuel path 16 is filtered by means of the fuel filter 24 on its way from the pre-supply pump 14 to the high-pressure pump 12 . It can be seen that the fuel flowing through the fuel path 16 flows through the fuel filter 22 , the pre-supply pump 14 and the fuel filter 24 on its way from the reservoir 18 to the high-pressure pump 12 .

In addition, the fuel system 10 has a return path 26 . The return path 26 includes return branches 28a-d, which are explained in more detail below. At least an excess portion of the fuel, which was delivered to the high-pressure pump 12 by means of the presupply pump 14, can be pumped out via the return branch 28a and thus via the return path 26 from the high-pressure pump 12, bypassing the fuel distribution element and bypassing the injectors, i.e. without passing through the fuel distribution element to flow and without flowing through the injectors, are guided back to and into the reservoir 18, in particular also bypassing the fuel filters 22 and 24 and the pre-supply pump 14. In particular, the fuel can circulate in such a way that the high-pressure pump only receives so much quantity arrives as needed. However, there is a forced leakage path in the high-pressure pump, which can correspond to the return branch 28a.

At least an excess portion of the fuel flowing through fuel filter 24 can be routed from fuel filter 24 back to and into reservoir 18 via return branch 28b and thus via return path 26, it being preferably provided that the fuel flowing through return branch 28b is of the fuel filter 24 has been or is filtered. At least an excess part of the fuel, which has flowed from the fuel distribution element to the injectors, can be routed from the injectors back to and into the reservoir 18 via the return branch 28c and thus via the return path 26 . Via the return branch 28d and thus via the return path 26, at least an excess part of the fuel, which by means of the high-pressure pump 12 to and into the fuel distribution element can be returned from the fuel distribution element back to and into the reservoir 18 . It can be seen that the fuel flowing through the return branches 28c and 28d is guided back to and into the reservoir 18 by the injectors or by the fuel distribution element, without entering the combustion chamber

Internal combustion engine, that is, without being burned in the internal combustion engine. Overall, it can be seen that the high-pressure pump 12, the fuel filter 24, the injectors and the fuel distribution element are components, with at least one excess part of the fuel being conveyed at least by means of the presupply pump 14 to the respective component of the fuel system 10 via the return path 26 is to be led back to and into the reservoir 18 by the respective component. The fuel flowing through the return branches 28a and 28b was or is being conveyed exclusively by means of the pre-supply pump 14 in relation to the high-pressure pump 12 and the pre-supply pump 14, with the fuel flowing through the return branches 28c and 28d being conveyed both by means of the pre-supply pump 14 and by means of the high-pressure pump 12, respectively becomes.

The fuel system 10 also includes a pressure control valve 30, which is explained in more detail below. Fuel system 10 can include a further pressure control valve, which is provided in particular in addition to pressure control valve 30 and is assigned to the fuel distribution element, by means of which a pressure of the fuel received in the fuel distribution element prevailing in the fuel distribution element can be adjusted, in particular regulated. In this case, for example, the fuel flowing through the return branch 28d comes from the further pressure control valve. This means in particular that the excess fuel flowing through the return branch 28d is diverted from or by the fuel distribution element by means of the additional pressure control valve in order thereby to set, in particular to regulate, the pressure of the fuel prevailing in the fuel distribution element. The deactivation means that at least part of the fuel received in the fuel distribution element is discharged from the fuel distribution element via the additional pressure control valve and introduced into the return branch 28d and then flows through the return branch 28d and returns by means of the return branch 28d and thus by means of the return path 26 to and into the reservoir 18 . The additional pressure control valve is also referred to as a PCV. The pressure control valve 30 is shown in FIGS. 2 and 3 in a respective schematic sectional view. As can be seen by looking at FIGS. 1 to 3 together, the pressure control valve 30 has a first connection 32, via which the fuel from the fuel path 16 flows from a branch point AS of the fuel path 16, which is arranged downstream of the presupply pump and upstream of the high-pressure pump 12, into the pressure control valve 30 can be initiated. For this purpose, the first connection 32 is fluidically connected to the fuel path 16 at the branching point AS via a fuel overflow line 34 . At least part of the fuel flowing through the fuel path 16 can thus be branched off from the fuel path 16 at the branching point AS and introduced into the fuel overflow line 34 . The fuel branched off and introduced into the fuel overflow line 34 can flow through the fuel overflow line 34 and is guided by the fuel overflow line 34 from the branching point AS to the first connection 32 and can flow into the pressure control valve 30 and flow through the connection 32 in the process. The pressure control valve 30 also has a second connection 36 which, in the exemplary embodiment shown in FIGS. 2 and 3, can be fluidly connected to the fuel path 16 via a fuel return line 38 at an introduction point ES or is presently connected. In the flow direction of the fuel flowing through the fuel path 16 , the branching point AS of the fuel path 16 is arranged downstream of the presupply pump 14 and upstream of the high-pressure pump 12 , in particular upstream of the fuel filter 24 . In the flow direction of the fuel flowing through the fuel path 16 , the introduction point ES of the fuel path 16 is arranged upstream of the pre-supply pump 14 and downstream of the reservoir 18 , in particular downstream of the fuel filter 22 .

As can be seen particularly well from FIGS. 2 and 3, the pressure control valve 30 comprises a valve element 40 which can be moved between at least one closed position shown in FIG. 2 and denoted by S and at least one open position shown in FIG. 3 and denoted by O. In the open position O, the ports 32 and 36 are more fluidly connected to each other than in the closed position S, so that, for example, at the same pressure and preferably also at the same temperature of the fuel in the open position O, a larger volume flow of fuel from the first port 32 to the second Connection 36 can flow than in the closed position S. For this purpose, it is provided in particular that in the closed position S the smallest flow cross section through which the fuel can flow of a connection path, via which the fuel can flow from the connection 32 to the connection 36, is smaller than in the open position is O. It is preferably provided that the smallest flow cross-section both in the open position O and is also greater than 0 in the closed position S. It is therefore provided in particular that the connection path is released in the open position O, and the connection path is preferably not interrupted in the closed position S, but rather released, although in the closed position S the smallest flow cross section of the connection path is smaller, i.e. smaller than in the open position is O. The fuel introduced into the pressure control valve 30 via the first connection 32 can be discharged from the pressure control valve 30 via the second connection 36 and introduced into the fuel path 16 at the introduction point ES. In other words, at least in the open position O, the branch point AS is fluidically connected to the inlet point ES, in particular more strongly than in the closed position S, so that the fuel can flow back from the branch point AS via the pressure control valve 30 to the inlet point ES. The aforementioned first fuel pressure prevails in particular in the fuel path 16 downstream of the pre-supply pump 14 and preferably upstream of the high-pressure pump 12, thus on a pressure side of the pre-supply pump 14, via the pressure side of which the fuel is conveyed away from the pre-supply pump 14 by means of the pre-supply pump 14 and towards the High-pressure pump 12 is funded. Thus, the branching point AS and the high-pressure pump 12 and presently also the fuel filter 24 are arranged on the pressure side of the pre-supply pump 14 . A portion of the fuel path 16 arranged or running upstream of the pre-supply pump 14 is arranged on a so-called suction side of the pre-supply pump 14, which draws in the fuel from the reservoir 18 via its suction side and thus conveys it towards and into itself. Thus, in the present case, the fuel filter 22 is arranged on the intake side. On the suction side, in particular in the fuel path 16, there is, for example, a third fuel pressure that is lower than the first fuel pressure. Thus, preferably in the closed position S, there is a pressure gradient from the port 32 to the port 36, with the first fuel pressure preferably prevailing at least essentially at the port 32 and the third fuel pressure at least essentially prevailing at the port 36. This pressure drop also exists from the branching point AS to the introduction point ES, at least in the open position O, and because of this pressure drop in the open position O of the valve element 40, at least the aforementioned part of the fuel flowing through the fuel path 16 flows from the branching point AS via the pressure control valve 30 flows to the discharge point ES. Thus, for example, the first fuel pressure can be set, in particular regulated, by means of the valve element 40, so that the first fuel pressure is also referred to as the setting or regulating pressure. It can thus be seen that via the second connection 36 the fuel which has flowed in or been introduced into the pressure control valve 30 via the connection 32 can be discharged from the pressure control valve 30 or is being discharged. The pressure control valve 30 also has a first control port 42 which, in the exemplary embodiment shown in the figures, can be fluidically connected or is presently connected to the fuel path 16 via a first control line 44, also referred to as a first control fuel line, at a first control point S1. The first control point S1 of the fuel path 16 is arranged in the direction of flow of the fuel flowing through the fuel path 16 downstream of the branching point AS and thus downstream of the pre-supply pump 14 and upstream of the high-pressure pump 12, with the first control point S1 being arranged downstream of the fuel filter 24 in the present case. A part of fuel path 16 arranged downstream of fuel filter 24 and thus first control point S1 and also high-pressure pump 12 are arranged on a so-called clean side of fuel filter 24, via the clean side of which fuel flows through fuel filter 24 and is filtered by fuel filter 24 24 flows off or away and in particular flows towards the high-pressure pump 12 . In this case, for example, the return branch 28b on the clean side of the fuel filter 24 can be fluidically connected or connected to the fuel filter 24, so that the fuel flowing through the return branch 28b and also the return branch 28a and also the fuel flowing through the return branch 28c and the return branch 28d can be removed by means of the fuel filter 24 has been or is filtered.

A further part of fuel path 16 that runs or is arranged upstream of fuel filter 24 is arranged on a so-called dirty side of fuel filter 24, onto which the fuel that has not yet been filtered by means of fuel filter 24 flows or can flow via its dirty side. On its way from the pre-supply pump 14 to the high-pressure pump 12, the fuel flows through the fuel filter 24 and from the dirt side to the clean side of the fuel filter 24, also referred to as the clean side, and is filtered by the fuel filter 24. It can thus be seen that the branching point AS, the pre-supply pump 14 and the inlet point ES are arranged on the dirty side of the fuel filter 24, so that the pre-supply pump 14, the fuel overflow line 34, the fuel return line 38 and, particularly in the open position O, the connections 32 and 36 through-flowing fuel, in particular fuel flowing from port 32 to port 36 , has not been or is not filtered by means of fuel filter 24 . However, the fuel flowing through the first control line 44 is filtered by means of the fuel filter 24 . 2 and 3 show particularly well that the valve element 40 can be acted upon via the first control connection 42 by a first pressure of the fuel prevailing at the first control point S1 of the fuel path 16 in the fuel path 16 and also referred to as the first application pressure. The first application pressure is preferably the first fuel pressure. By subjecting the valve element 40 to the first application pressure, the valve element 40 can be acted upon by a first force resulting from the first application pressure, which is illustrated in FIGS. 2 and 3 by a force arrow F1. The valve element 40 can be moved from the closed position S into the open position O by means of the first force F1. The valve element 40 can be moved, in particular translationally, between the closed position S and the open position O, along a direction of movement illustrated by a double arrow. In order to move the valve element 40 from the closed position S into the open position O, the valve element 40 is moved, in particular translationally, in a first valve element direction illustrated by an arrow 46, the first valve element direction running parallel to the direction of movement. In order to move the valve element 40 from the open position O to the closed position S, the valve element 40 is moved, in particular translationally, in a second valve element direction illustrated by an arrow 48, the second valve element direction running parallel to the direction of movement and being opposite to the first valve element direction. It can be seen that the first force (force arrow F1) resulting from the first pressure and also referred to as the first control force acts in the first valve element direction (arrow 46).

In order to be able to set, in particular regulate, the first fuel pressure in a particularly advantageous manner and in particular in a particularly simple and cost-effective manner, the pressure control valve 30 has a second control connection 50 . In the exemplary embodiment shown in FIGS. 1 to 3, the second control connection 50 can be fluidically connected or is presently connected to the return flow path 26 via a second control line 52, also referred to as a second control fuel line. Via second control port 50, valve element 40 can be acted upon by a fourth fuel pressure, also referred to as the second actuation pressure, which prevails in return path 26, and can thereby be acted upon by a force resulting from the fourth fuel pressure that opposes or acts in the opposite direction to the first force and is illustrated by a second force arrow F2 , Second force can be applied, by means of which the valve element 40 can be moved from the open position O into the closed position S. From FIGS. 2 and 3 it can be seen from the force arrow F2 that the second force acts in the second direction of the valve element and is therefore directed in the opposite direction to the first force. Becomes thus, for example, the first fuel pressure is referred to as the first control pressure and the first force is referred to as the first control force, the fourth fuel pressure is referred to as the second control pressure and the second force is referred to as the second control force, with the fourth fuel pressure and the second force corresponding to the first fuel pressure and opposes the first force. Therefore, the fourth fuel pressure is also referred to as counter pressure and the second force is also referred to as counter force.

Furthermore, it can be seen from FIGS. 2 and 3 that in the closed position S at least the second connection 36 is fluidically separated from the first control connection 42 by means of the valve element 40 . In particular, it can be provided that in the closed position S, the connection 32 and the second control connection 50 are also fluidically separated from the control connection 42 by means of the valve element 40 . In the open position O, however, the port 36 is fluidically connected to the control port 42 . Provision is made in particular for the port 32 and the control port 50 to also be fluidically connected to the control port 42 in the open position O.

In the exemplary embodiment shown in FIG. 1, the second control connection 50 can be or is connected fluidly to the return path 26, in particular to the return branch 28a, at a second control point S2, in particular via the second control line 52. The fuel at the fourth fuel pressure in the control line 52 can be conducted to the control port 50 by means of the control line 52 or act on the valve element 40 via the control port 50 . In the exemplary embodiment shown in FIG. 1, the second control point S2 is arranged in the return path 26, in particular in the return branch 28a, upstream of the collecting element 54. It is conceivable that the control point S2 is arranged in or on the collector element 54, so that the collector element has the control point S2. Furthermore, it is also conceivable that the second control point S2 is provided on one of the return branches 28b-d.

1 shows that, for example, the return branches 28a-d formed by respective return lines are brought together or combined via a collecting element 54 to form a total return branch 56, with the total return branch 56 being formed by a total return line, for example. This means in particular that the fuel flowing through the individual return branches 28a-d can flow through the overall return branch 56 of the return path 26 . It can also be seen from Fig. 1 that the fuel flowing through the fuel return line 38, and therefore the fuel flowing from the connection 32 to the connection 36, is guided back to the suction side of the pre-supply pump 14 and thus flows back into the pre-supply pump 14 and flows through the pre-supply pump 14 can after it had previously flowed through the pre-supply pump 14.

It can be seen from FIGS. 2 and 3 that the pressure control valve 30 has a valve housing 58 which, in particular directly, forms or delimits the connections 32 and 36 and the control connections 42 and 50 . In addition, the valve housing 58 forms or delimits a receptacle 60 embodied, for example, as a bore, in particular directly. The valve housing 58 has, for example, two housing elements 62 and 64 which, for example, are components which are formed separately from one another and are connected to one another. In this case, the housing element 62 forms or delimits the connections 32 and 36 and the control connections 42 and 50, in particular directly. The receptacle 60 is partly delimited by the housing element 62 and partly by the housing element 64, in each case directly. The valve element 40 is accommodated in the receptacle 60 in a translationally movable manner relative to the valve housing 58 between the closed position S and the open position O along the direction of movement. Along the direction of movement, the receptacle 60 is closed, in particular completely, at its two opposite ends E1 and E2 along the direction of movement. Furthermore, it is provided that the first connection 32, the second connection 36, the first control connection 42 and the second control connection 50 at a respective opening point M1, M2, M3 and M4 along a direction perpendicular to the direction of movement, in particular directly, in the Recording 60 open, the orifices M1-4 are spaced from each other. The orifice M2 of the second connector 36 is located along the direction of movement between the orifices M1 and M3 of the first connector 32 and the control connector 42, and the orifice M1 of the first connector 32 is along the direction of movement between the orifices M2 and M4 of the second connector 36 and the second control terminal 50 are arranged. It is also provided that an outlet opening 66 of the first connection 32, which is arranged at the opening point M1 of the first connection 32 and which opens out directly at its opening point M1 via the outlet opening 66 into the receptacle 60, in the closed position S of the valve element 40 along the previously mentioned , perpendicular to the direction of motion extending and pointing towards the valve element 40 direction is completely overlapped by the valve element 40 with a game.

The valve element 40 has a sealing surface 40a, and the valve housing 58, in particular the housing element 62, has a valve seat 58a. In the closed position S, the sealing surface 40a and thus the valve element 40 are seated on the corresponding valve seat 58a, as a result of which the valve element 40 is sealed against the valve housing 58 at a sealing point. In this way, the valve element 40 blocks a flow path in the closed position S, via which the fuel can or could flow from the control connection 42 to the connection 36 or vice versa. In the open position O, the valve element 40 releases said flow path, since in the open position O the sealing surface 40a is at a distance from the valve seat 58a. The fuel can therefore not flow through the flow path in the closed position S. In the open position O, however, the fuel can flow through the flow path and thus flow from the control port 42 to the port 36 . In the exemplary embodiment shown in FIGS. 2 and 3, the valve seat 58a is arranged, in particular along the direction of movement of the valve element 40, between the second port 36 and the control port 42 or between the opening points M2 and M3, so that the aforementioned sealing point is between the control port 42 and the connection 36 or between the openings M3 and M2. By lifting the valve element 40 with its sealing surface 40a off or from the valve seat 58a, the valve element 40 is in its open position O shown in FIG. 3. If the sealing surface 40a is in, in particular direct, contact with the valve seat 58a, the valve element is in position 40 in its closed position S (Fig. 2). The receptacle 60 and the valve element 40 are preferably designed to be rotationally symmetrical along a common axis A.

At least in the closed position S, a first clearance SP1 is preferably provided in a first region B1 of the valve element 40 between the valve element 40 or the region B1 and the valve housing 58, in particular the receptacle 60, with this clearance SP1 preferably being less than 10 micrometers. Alternatively or additionally, a second play SP2 can be provided in a region B2 of the valve element 40 between the valve element 40, in particular the region B2, and the valve housing 58, in particular the receptacle 60, wherein the second play SP2 can be greater than or equal to 10 micrometers . It is also conceivable that the first play SP1 is less than or equal to 10 microns and the second play SP2 is greater than 10 microns. Furthermore, it is conceivable that the game SP2 is specifically provided or produced. The area B1 is provided at the first end E1 of the valve element 40 along the second valve element direction (arrow 48). The second area B2 is provided at the second end E2 of the valve element 40 along the first valve element direction (arrow 46). Between the two areas B1 and B2, the valve element 40 has a smaller diameter in a third area B3 than in the areas B1 and B2. The sealing surface 40a is arranged between the areas B3 and B1. The valve seat 58a is provided between a fourth area B4 of the receptacle 60 in the second valve element direction (arrow 48) and a fifth area B5 of the receptacle 60 in the first valve element direction (arrow 46). The fourth area B4 has a smaller diameter than the fifth area B5.

It can be seen that the game SP1 is provided in the area B1 or between the area B1 and the fourth area B4, in particular in a targeted manner, and the game SP2 is in the area B2 or between the area B2 and the fifth area B5, in particular purposeful, intended. Preferably, the second clearance SP2 in the closed position S allows for a targeted leakage of the fuel from the first port 32 to the second control port 50 in the pressure control valve 30, in particular in the valve housing 58, that is to say it is formed or produced. In other words, the second clearance SP2 is preferably a specifically provided leakage path, via which fuel can flow in the closed position S from the connection 32 into the receptacle 60 and from the receptacle 60 to and into the second control connection 50 . As a result, when valve element 40 is in its closed position S, i.e. in its closed position, an advantageous outflow of the fuel downstream of the pre-supply pump 14 via the branching point AS to the first connection 32 of the pressure control valve 30 with the second clearance SP2 between the orifice point M1 of the outlet opening 66 of the first port 32 in the receptacle 60 and overlapping valve element 40 in the second area B2 can be set so that not too much fuel flows via the second control line 52 into the return path 26, whereby a sufficiently large amount of fuel from the pre-supply pump 14 of the High-pressure pump 12 can be made available.

Since the sealing surface 40a rests against the valve seat 58a in the closed position S, the control connection 42 is separated from the connection 36 in the closed position S. In the open position O, however, it is preferably provided that, in particular via the play SP1, the control port 42 is fluidly connected to the port 36, so that For example, alternatively or additionally, provision can be made for the first play SP1 in the open position O to be a further, targeted leakage from the control connection 42 to the second connection 36, thus forming a targeted, second leakage path in the open position O, via which in the open position O of the valve element 40 fuel can flow from the first control port 42 into the receptacle 60 and from the receptacle 60 into and through the port 36 . The fuel flowing into the receptacle 60 from the first control port 42 is taken from the pressure side of the pre-supply pump 14, and the second port 36 is connected to the suction side of the pre-supply pump 14, so that there is a corresponding pressure drop in the direction of the suction side, creating the second leakage path is an inevitable leakage and contamination of fuel that has already been filtered by means of fuel filter 24 by fuel that has not yet been filtered by means of fuel filter 24 can be avoided.

In the following, an operation and thus a function of the fuel system 10 are described in more detail and by way of example. The pre-supply pump 14 draws in the fuel from the reservoir 18 via a fuel supply line 69, in particular the fuel path 16, as a result of which the fuel is delivered from the reservoir 18 through the fuel supply line 69 by means of the pre-supply pump 14 and is thus delivered to the pre-supply pump 14. In addition, as a result, the fuel is conveyed from the reservoir 18 through the fuel filter 22 (pre-filter). The fuel is conducted away from the pre-supply pump 14 and to the high-pressure pump 12 via the fuel filter 24 (main filter), for example at the first fuel pressure, which is also referred to as the delivery pressure. The first fuel pressure acts on the valve element 40 via the first control line 44 and the first control connection 42, in particular on its first side SE1, which is also referred to as the upper side. The fourth fuel pressure prevailing in the return path 26, which is also referred to as the tank return, acts as a back pressure via the second control line 52 and the second control port 50 on the valve element 40, in particular its second side SE2, with the second side SE2 of the first side SE1 along the direction of movement (double arrow 45) is opposite or turned away. Expressed again in other words, the fourth fuel pressure is present via the second control line 52 in the second control port 50 on the valve element 40, in particular on the second side SE2, which is also referred to as the underside.

A pressure increase at high-pressure pump 12 leads via first control point S1, first control line 44 and first control port 42 to a higher pressure or to a pressure increase on side SE1, as a result of which, for example, The valve element 40 that is initially in the closed position S is moved from the closed position S into the open position O, and is therefore opened. As a result, the connections 32 and 36 are fluidically connected to one another or more fluidly connected to one another than in the closed position S, so that the fuel is recirculated from the branch point AS via the connections 32 and 36 to the inlet point ES. This results in a pressure drop at the high-pressure pump inlet of the high-pressure pump 12, so that the valve element 40 is moved, for example, from the open position O back into the closed position S or in the direction of the closed position S. The valve element 40 or the first fuel pressure is thus regulated. In other words, the first fuel pressure is regulated by means of the pressure control valve 30 .

In particular, the pressure control valve 30 is designed as a servo valve. This means in particular that a fuel coming from the first connection 32 can be adjusted at least essentially continuously or steplessly by means of the valve element 40 . In other words, by moving the valve element 40 into different open positions O, different values of a quantity of fuel flowing through the first connection 32 from the receptacle 60 into the second connection 36 can be set.

The first fuel pressure present at valve element 40 or acting on valve element 40 via control port 42 is at least essentially an inlet pressure of high-pressure pump 12. The fourth fuel pressure acting at valve element 40 or on valve element 40 via second control port 50 is at least essentially a so-called return pressure of the fuel in the return path 26. For example, the first fuel pressure is at least essentially 6 bar. In other words, the fuel at the first control point S1 can have at least essentially 6 bar. It is also conceivable that the pressure of the fuel caused by the pre-supply pump 14 downstream of the pre-supply pump 14 and upstream of the fuel filter 24 is at least essentially 6 bar, so that the first fuel pressure or the pressure prevailing at the first control point S1 can be 6 bar. 6 bar plus a pressure loss across the fuel filter 24 can be present at the branching point AS. A target pressure at control point S1 can be around 6 bar. A pressure loss occurs in the direction of flow. The pressure at branch point AS should therefore be greater than 6 bar (6 bar plus the pressure loss between branch point AS and control point S1). The third fuel pressure prevailing at the introduction point ES, for example for example, a suction pressure of the pre-supply pump 14, the suction pressure being present at the connection 36 via the fuel return line 38. Contamination of the clean side or of the control port 42 is avoided by the pressure drop from the control port 42 to the port 36 . The respective play SP1 or SP2 is also referred to as the guide play, which is guided, for example, in the areas B1 and B2 of the valve element 40 by means of the valve housing 58 .

In a non-regulating operation, the valve element 40 is in the closed position S. This means that the valve element 40 is closed. The valve element 40 thus sits with its sealing surface 40a on the valve seat 58a, as a result of which the control connection 42 is separated from the connection 36 and consequently a flow of fuel from the control connection 42 to the connection 36 is prevented. When the first fuel pressure increases, i.e. between the presupply pump 14 and the high-pressure pump 12, there is an increase in pressure in the first control port 42, as a result of which the valve element 40, which is embodied, for example, as a valve piston, is moved, in particular pressed, starting from the closed position S into its open position O. There is thus a recirculation of fuel from the pressure side of the pre-supply pump 14 to the suction side of the pre-supply pump 14, as a result of which there is no further increase in pressure at the high-pressure pump inlet. In the open position O there is a flow of fuel or a leak from the control port 42 to the second port 36 due to a corresponding pressure gradient or pressure drop. In this way, undesired contamination of the clean side can be avoided. Furthermore, the second clearance SP2 is preferably a second targeted leakage, which occurs exclusively from the connection 32 to the second control connection 50 due to a corresponding pressure gradient or pressure drop.

The connection 32 is arranged on said dirty side, with the control connection 50 being arranged on the clean side. The in particular targeted leakage from the connection 32 to the control connection 50, also referred to as forced leakage, means or results in dirty or unfiltered fuel flowing into the return, ie to the clean or filtered fuel. However, this is not critical since the fuel runs back into the tank.

The forced leakage from the connection 32 to the control connection 50 is not absolutely necessary, but a certain amount of return flow protects against overheating of the fuel in summer, ie at high temperatures. Pressure control valve 30 includes a mechanical spring 68 in the present case, which can be supported or is supported along the direction of movement (double arrow 45) on the one hand, in particular directly, on valve element 40 and on the other hand, in particular directly, on valve housing 58, in particular on housing element 64. At least in the open position O, the spring 68 provides a spring force illustrated in Fig. 3 by a force arrow F3 which, like the second force F2, acts at least indirectly, in particular directly, on the valve element 40 in the second valve element direction and thus counteracts the first force F1 is set or directed in the opposite direction. The second force F2 and the spring force F3 add up to an overall force that acts at least indirectly, in particular directly, on the valve element 40 in the second valve element direction 48 . The total force is an opposing force that opposes or is directed in the opposite direction to the first force F1. If the first force F1 and the total force from the second force F2 and the third force F3 or the counterforce are in equilibrium while, for example, the valve element 40 is in its open position O, the valve element 40 remains in the open position O, or while if the valve element 40 is in the closed position S, the valve element 40 remains in the closed position S. If the total force from the second force F2 and the third force F3 is greater than the first force F1, the valve element 40 moves from the open position O in the closed position S moves and / or held in the closed position S. If the first force F1 is greater than the total force from the second force F2 and the third force F3, the valve element 40 is held in the open position O and/or is moved from the closed position S into the open position O.

It can also be seen from Fig. 1 that in the fuel supply line 69 and upstream of the fuel filter 22 and downstream of the reservoir 18 there is a heating element 70, in particular an electric one, by means of which the fuel flowing through the fuel supply line 69 is heated on its way from the reservoir 18 to the fuel filter 22 heated using electrical energy or electricity, that is, can be heated. A check valve 72 is also arranged in fuel supply line 69 downstream of reservoir 18 and upstream of fuel filter 22, in particular upstream of heating element 70, which blocks or closes in the direction of reservoir 18 and in the opposite direction, i.e. in the direction of fuel filter 22 or Heating element 70 opens. In the fuel supply line 69 and thus in the fuel path 16, a check valve 82 is arranged upstream of the fuel filter 22 and downstream of the heating element 70, which in the direction of the Heating element 70 blocks and opens in the direction of the fuel filter 22. A check valve 74 is arranged in the return path 26, in particular in the overall return branch 56, downstream of the collecting element 54 and upstream of the reservoir 18, which closes or blocks in the direction of the reservoir 18 and opens in the direction of the collecting element 54. The opening direction of the check valves 72 and 74 is the same. Both valves are mechanically pushed open when the tank lines are connected. The valves prevent fuel from escaping from the fuel circuit when the tank lines are disconnected.

A spring-loaded check valve 76 is arranged in the return branch 28a, in particular upstream of the collecting element 54 and very particularly upstream of the second control point S2, which opens in the direction of the collecting element 54 or in the direction of the control point S2 and in the opposite direction, i.e. in the direction of the high-pressure pump 12 (high-pressure fuel pump) closes or blocks. In this case, a throttle 80 is arranged in the return branch 28a downstream of the high-pressure pump 12 and upstream of the check valve 76, which throttle has, for example, a throughflow of 10 liters of fuel per hour. In the return branch 28c, in particular upstream of the collecting element 54, there is a spring-loaded check valve 78 which opens in the direction of the collecting element 54 and closes or blocks in the opposite direction, i.e. in the direction of the fuel distribution element or the injectors. In the exemplary embodiment shown in Fig. 1, the second control point S2 is arranged in the return branch 28a, so that the second control port 50, in particular via the second control line 52, can be or is connected fluidly to the return branch 28a of the high-pressure pump 12 at the second control point S2. For example, it would be conceivable for the second control point S2 to be arranged on or in the collector element 54 so that, for example, the second control connection 50 could be or is connected to the collector element 54, in particular via the second control line 52.

2 shows that in the closed position S the connection 32 or the orifice point M1 is completely overlapped or covered by the region B2 along a direction running perpendicular to the direction of movement and pointing towards the valve element 40 . In the open position O, however, the connection 32 or the opening point M1 is at least partially, in particular at least predominantly and thus at least more than half or completely, through the area B3 along the previously described direction overlaps, so that in the open position O the connections 32 and 36 are more fluidly connected to one another than in the closed position S.

reference list

10 fuel system

12 high pressure pump

14 pre-supply pump

16 first fuel path

18 reservoirs

20 second fuel path

22 first fuel filter

24 second fuel filter

26 return path

28a-d return branch

30 pressure control valve

32 first connection

34 fuel overflow line

36 second port

38 fuel return line

40 valve element

40a sealing surface

42 first control terminal

44 first control line

45 double arrow

46 arrow 48 arrow 50 second control connection 52 second control line 54 collector element 56 total return branch 58 valve housing 58a valve seat 60 receptacle 62 housing element 64 housing element 66 outlet opening 68 spring 69 FUEL SUPPLY LINE

70 heating element 72 non-return valve 74 non-return valve 76 non-return valve 78 non-return valve 80 throttle 82 non-return valve A axis AS branch point B1 first area B2 second area B3 third area B4 fourth area B5 fifth area E1 first end E2 second end ES inlet point F1 force arrow F2 force arrow F3 force arrow M1 outlet point M2 Outlet M3 Outlet M4 Outlet O Open position S Closed position

51 first control station

52 second control point SE1 first side SE2 second side SP1 first game SP2 second game

Claims

patent claims

1. Pressure control valve (30) for setting a pressure of a fuel in a fuel system (10) through which the fuel can flow for an internal combustion engine, with:

- a first connection (32) via which the fuel can be introduced into the pressure control valve (30),

- a second connection (36) via which the fuel introduced into the pressure control valve (30) via the first connection (32) can be discharged from the pressure control valve (30),

- a valve element (40) which can be moved between at least one closed position (S) and at least one open position (O), and

- a first control connection (42), via which the valve element (40) can be subjected to a first fuel pressure and thereby to a force (F1) resulting from the pressure, by means of which the valve element (40) moves from the closed position (S) to the open position (O) can be moved, characterized in that the pressure control valve (30) has a second control connection (50) via which the valve element (40) can be subjected to a fourth fuel pressure and thereby to a force resulting from the fourth fuel pressure (F1) can be acted upon by a second force (F2) in the opposite direction, by means of which the valve element (40) can be moved from the open position (O) to the closed position (S), wherein in the closed position (S) at least the second connection (36) of is separated from the first control port (42), and wherein in the open position (O) the second port (36) is fluidically connected to the first control port (42), wherein along the direction of movement (45) the receptacle (60) is closed at its two ends (E1, E2) both in the closed position (S) and in the open position (O).

2. Pressure control valve (30) according to claim 1, characterized in that in the closed position (S) a targeted leakage of fuel from the first port (32) to the second control port (50) in the pressure control valve (30) is provided.

3. Pressure control valve (30) according to Claim 1 or 2, characterized in that the pressure control valve (30) has a valve housing (58) which delimits a receptacle (60) in which the valve element (40) moves along a direction of movement (45) between the closed position (S) and the open position (O) relative to the valve housing (58) is accommodated in a translationally movable manner.

4. Pressure control valve (30) according to claim 2 or 3, characterized in that the first connection (32), the second connection (36), the first control connection (42) and the second control connection (50) along an oblique or perpendicular to the direction of movement (45) extending direction in the recording (60) open.

5. Pressure control valve (30) according to any one of claims 2 to 4, characterized in that the first port (32), the second port (36), the first control port (42) and the second control port (50) at respective spaced apart Orifice points (M1, M2, M3, M4) open into the receptacle (60).

6. Pressure control valve (30) according to claim 5, characterized in that the opening point (M2) of the second connection (36) along the direction of movement (45) between the opening points (M3, M1) of the first control connection (42) and the first connection ( 32) lies.

7. Pressure control valve (30) according to claim 5 or 6, characterized in that the opening point (M1) of the first connection (32) along the direction of movement (45) between the opening points (M4, M2) of the second control connection (50) and the second Connection (36) is located.

8. Pressure control valve (30) according to one of Claims 5 to 7, characterized in that an outlet opening (66) of the first connection (32) which is arranged at the opening point (M1) of the first connection (32) and which at its opening point (M1) via the outlet opening (66) into the receptacle (60), at least in the closed position (S) of the valve element along a direction running perpendicular to the direction of movement (45) and pointing towards the valve element (40) through the valve element (40). is overlapped with a second game (SP2).

9. fuel system (10) for delivering fuel for an internal combustion engine, with at least one pressure control valve (30) according to any one of the preceding claims.