1. A method for supplying fuel to a high pressure pump (1) in a fuel injection system of an internal combustion engine, wherein for delivery and for delivery quantity control, a delivery pump (3) is used which is driven by an electric motor and arranged in a low pressure circuit (2) and by means of which, depending on the motor rotation speed selected, a specific quantity of fuel is supplied to the high pressure pump (1), in which the fuel is first compressed and then supplied to a high pressure fuel accumulator (4), characterized in that the fuel pressure is regulated by a pressure regulation valve (5) arranged on a suction side of the high pressure pump (1), wherein with the pressure regulation valve (5) in a closed position, a supply of fuel to the high pressure pump (1) is still ensured for at least one of lubrication and cooling via the low pressure circuit (2) and the delivery pump (3).
2. The method as claimed in claim 1, characterized in that with the pressure regulation valve (5) in the closed position, the at least one of lubrication and cooling of the high pressure pump (1) is ensured via an opening pressure of the pressure regulation valve (5).
3. The method as claimed in claim 1, characterized in that a high pressure quantity is defined via a curve of the pressure regulation valve (5).
4. The method as claimed in claim 1, characterized in that leakages in a region of the pressure regulation valve (5) are compensated for by at least one of arranging a further pressure regulation valve on the high pressure fuel accumulator (4), use of a zero delivery choke, and corresponding control of injectors.
5. The method as claimed in claim 1, characterized in that, to improve the at least one of lubrication and cooling of the high pressure pump (1), a two-stage pressure regulation valve (5) is used.
6. The method as claimed in claim 1, characterized in that, to improve the at least one of lubrication and cooling of the high pressure pump (1), a choke (6) is used which is connected in parallel to a lubrication and cooling line (7).
7. The method as claimed in claim 1, characterized in that, for flow restriction, a choke (6) is used which is arranged in a lubrication and cooling line (7).
8. A fuel injection system of an internal combustion engine, with a high pressure pump (1) which delivers fuel at high pressure and supplies the fuel to a high pressure fuel accumulator (4), and with a delivery pump (3) driven by electric motor and arranged in a low pressure circuit (2) to supply fuel to the high pressure pump (1), wherein a delivery quantity can be regulated via the delivery pump (3), characterized in that a pressure regulation valve (5) is provided on a suction side of the high pressure pump (1) to regulate the fuel pressure, wherein when the pressure regulation valve (5) is in a closed position, a sufficient quantity of fuel for at least one of lubrication and cooling of the high pressure pump (1) is ensured via the low pressure circuit (2) and the delivery pump (3).
9. The fuel injection system as claimed in claim 8, characterized in that the pressure regulation valve (5) is constructed in two stages.
10. The fuel injection system as claimed in claim 8, characterized in that at least one choke (6) is at least one of arranged in a lubrication and cooling line (7) and connected in parallel thereto.
11. The fuel injection system as claimed in claim 8, characterized in that the fuel injection system is a common rail injection system.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A connecting element for two service switching devices, which are arranged next to one another in a row and bear against one another with broad sides of said service switching devices, housings of each of said service switching devices are formed from two shell-like housing parts, the connecting element having an approximately cylindrical basic body having a first outer diameter and front sides, on each of said front sides two axially protruding first and second spreading arms which spring open radially are integrally formed, an outer diameter of said spreading arms is smaller than the first outer diameter of the basic body, and free ends of said spreading arms have radially protruding tabs on opposite surface lines, said tabs, in a fitted state, latch in behind recesses on the housings, which are to be connected to the connecting element, of the adjacent service switching devices, wherein one distancing piece is fitted at least to a first or second spreading arm such that a height of the distancing piece determines a minimum distance to which the first and second spreading arms can be pushed towards one another, wherein the free ends of the tabs are conically tapered.
2. The connecting element as claimed in claim 1, wherein one first and second distancing piece is fitted to one first and second spreading arm.
3. The connecting element as claimed in claim 2, wherein the first and second distancing pieces are laterally offset with respect to one another and have a same height, with a result that, when the first and second spreading arms are pressed together, the two distancing pieces slide past one another.
4. The connecting element as claimed in claim 3, wherein the first and second distancing pieces have a trapezoidal cross-sectional contour and are arranged in mirror-image fashion with respect to one another.
5. The connecting element as claimed in claim 1, wherein the distancing pieces consist of a same material as the spreading arms.
6. A connecting element as claimed in claim 1 which is manufactured using an injection-molding technique.
7. The connecting element as claimed in claim 6, wherein the connecting element is manufactured together with the spreading element in an injection-molding process.
8. A connecting element as claimed in claim 1 which is manufactured from plastic.
9. The connecting element as claimed in claim 1, wherein the spreading arms, in a fitted state, can be pushed towards one another at a free end using a special tool.
10. The connecting element as claimed in claim 1, wherein the front faces of the basic body are in a form of a truncated cone, cone angles being open towards one another.
11. The connecting element as claimed in claim 10, wherein a cone base diameter is larger than an outer diameter of a cylindrical outer surface and smaller than a first outer diameter of the cylindrical basic body.
12. The connecting element as claimed in claim 1, wherein tab faces opposite the front faces have a conical shape and a cone angle open in an opposite direction.
13. A connection for service switching devices, housings of each of said service switching devices are formed from two shell-like housing parts, having a connecting element as claimed in claim 1, each housing, starting from a partition line between the two housings, having a cylindrical, first depression having a first inner diameter, which corresponds to a cone base diameter of the connecting element, and, starting from a housing broad side, having a cylindrical, second depression having a second inner diameter, which corresponds to an outer diameter of a cylindrical basic body, said first and second depressions are connected to one another by a cylindrical through-hole, wherein the connecting element engages with tab faces behind recesses, which are produced at a transition between the first cylindrical depressions in the housing parts to be connected of the service switching devices and the cylindrical through-holes.
14. The connection as claimed in claim 13, wherein outer contours of radially protruding tabs of the connecting element, in an uninstalled state, rest on an outer surface having oval cross sections and, during fitting, rest on an outer surface having circular cross sections.
15. The connecting element as claimed in claim 1, wherein said service switching devices comprise line circuit breakers or residual-current circuit breakers.
16. A connecting element for two service switching devices, which are arranged next to one another in a row and bear against one another with broad sides of said service switching devices, housings of each of said service switching devices are formed from two shell-like housing parts, the connecting element having an approximately cylindrical basic body having a first outer diameter and front sides, on each of said front sides two axially protruding first and second spreading arms which spring open radially are integrally formed, an outer diameter of said spreading arms is smaller than the first outer diameter of the basic body, and free ends of said spreading arms have radially protruding tabs on opposite surface lines, said tabs, in a fitted state, latch in behind recesses on the housings, which are to be connected to the connecting element, of the adjacent service switching devices, wherein one distancing piece is fitted at least to a first or second spreading arm such that a height of the distancing piece determines a minimum distance to which the first and second spreading arms can be pushed towards one another, wherein the first and second distancing pieces are laterally offset with respect to one another and have a same height, with a result that, when the first and second spreading arms are pressed together, the two distancing pieces slide past one another.
17. A connection for service switching devices, housings of each of said service switching devices are formed from two shell-like housing parts, having a connecting element having an approximately cylindrical basic body having a first outer diameter and front sides, on each of said front sides two axially protruding first and second spreading arms which spring open radially are integrally formed, an outer diameter of said spreading arms is smaller than the first outer diameter of the basic body, and free ends of said spreading arms have radially protruding tabs on opposite surface lines, said tabs, in a fitted state, latch in behind recesses on the housings, which are to be connected to the connecting element, of the adjacent service switching devices, wherein one distancing piece is fitted at least to a first or second spreading arm such that a height of the distancing piece determines a minimum distance to which the first and second spreading arms can be pushed towards one another, each housing, starting from a partition line between the two housings, having a cylindrical, first depression having a first inner diameter, which corresponds to a cone base diameter of the connecting element, and, starting from a housing broad side, having a cylindrical, second depression having a second inner diameter, which corresponds to an outer diameter of a cylindrical basic body, said first and second depressions are connected to one another by a cylindrical through-hole, wherein the connecting element engages with tab faces behind recesses, which are produced at a transition between the first cylindrical depressions in the housing parts to be connected of the service switching devices and the cylindrical through-holes, wherein outer contours of radially protruding tabs of the connecting element, in an uninstalled state, rest on an outer surface having oval cross sections and, during fitting, rest on an outer surface having circular cross sections.