WO2013029872A1

WO2013029872A1 - Positioning of a pressure regulator in a fuel supply system with a brushlessly operated fuel pump

Info

Publication number: WO2013029872A1
Application number: PCT/EP2012/064390
Authority: WO
Inventors: Martin Beyer; Karsten Scholz
Original assignee: Robert Bosch Gmbh
Priority date: 2011-09-01
Filing date: 2012-07-23
Publication date: 2013-03-07
Also published as: DE102011081965A1

Abstract

Proposed is a fuel supply system (1) for the supply of fuel to an internal combustion engine (3). The fuel supply system (1) has a fuel pump (5), a filter (7) and a pressure regulator (11). The fuel pump (5) is designed to deliver fuel (9) to the internal combustion engine (3). The filter (7) is arranged between the fuel pump (5) and the internal combustion engine (3) and is designed to remove undesired particles from the fuel (9) that is delivered to the internal combustion engine (3). Here, the pressure regulator (11) is designed to regulate a system pressure of the fuel (9). The pressure regulator (11) is arranged between the fuel pump (5) and the filter (7). Here, the fuel pump (5) has a brushlessly commutated motor (13).

Description

description

Positioning of a Pressure Regulator in a Fuel Supply System with a Brushless Fuel Pump Prior Art

With the help of fuel supply systems, fuel is turned off

Fuel tank promoted to an internal combustion engine. For this purpose, the system may have a pump. Further, the system may include a filter that rejects the fuel that is supplied to the internal combustion engine

Cleans particles.

It can be differentiated between regulated and unregulated systems. In unregulated systems, a possibly constant amount of fuel per unit time is promoted and not required by the internal combustion engine

Fuel excess is directed back into the fuel tank. In regulated systems, the fuel delivery is designed according to the engine requirements. The pressure of the fuel provided to the internal combustion engine should only vary within a defined range. For this purpose, a pressure regulator can be provided in the system. The pressure regulator is usually installed between the engine and the filter. However, the installation of the pressure regulator after the filter can require a lot of work and material. For example, additional tubing is necessary if the filter is outside and the pressure regulator is inside the fuel tank

is arranged. Furthermore, a positioning of the pressure regulator on

predetermined location in the fuel supply system space optimization of the fuel supply system in the way. If the filter is arranged between the pressure regulator and the internal combustion engine, as shown, for example, in JP 08 218 984 A, then the pressure regulator is present

Impurities are not adequately protected and may leak. Furthermore, the filter attached to the filter may e.g. over the life of the filter varying pressure drop will not be affected by the pressure regulator.

Disclosure of the invention

There may therefore be a need for an improved fuel supply system in which an installation, material and cost can be reduced while a space optimization is possible and the

Pressure regulator is also protected from contamination.

This object can be achieved by the subject matter of the present invention according to the independent claims. Advantageous embodiments of the present invention are described in the dependent claims.

In the following, features, details and possible advantages of a device according to embodiments of the invention will be discussed in detail.

According to a first aspect of the invention, a fuel supply system for supplying fuel to an internal combustion engine is presented. The fuel supply system includes a fuel pump, a filter and a pressure regulator. The fuel pump is running, fuel

For example, to promote from a fuel tank to an internal combustion engine. The filter is arranged between the fuel pump and the internal combustion engine and is designed to clean the fuel delivered to the internal combustion engine of undesirable particles. The pressure regulator is designed to regulate a system pressure of the fuel. The pressure regulator is arranged hydraulically between the fuel pump and the filter. The fuel pump has a brushless commutated motor.

In other words, the idea of the present invention is based on hydraulically positioning the pressure regulator in front of the filter, in particular in front of a fine filter, using a brushless commutated fuel pump for fuel delivery. By positioning the pressure regulator hydraulically in front of the filter or upstream of the filter, the

Pressure regulator can be arranged within the fuel supply system so that it contributes to a space-optimal design of the fuel supply system. Furthermore, the installation, the material and the

Cost of making the fuel supply system thanks to the

Positioning of the pressure regulator can be saved hydraulically in front of the filter. In particular, can be dispensed with an additional tubing between an externally disposed filter and the fuel tank. The arrangement of the pressure regulator in front of the filter is advantageously made possible by using a fuel pump in a brushlessly commutated motor. This ensures that the pressure regulator can not be contaminated, for example by a Kohleabrieb. The fuel supply system can be arranged for example in a fuel tank of a means of transport, in particular of a motor vehicle. The components of the fuel supply system can be arranged completely or partially in the fuel tank. For example, the filter may also be arranged outside of the fuel tank. The fueled internal combustion engine, for example, an internal combustion engine, such as

Example be a gasoline or diesel engine. Before the engine, i. upstream of the internal combustion engine, an injection system may be provided, via which the internal combustion engine is supplied with fuel. The fuel supply system may have other components in addition to the fuel pump, the filter and the pressure regulator. For example, the fuel supply system may include a storage pot in which the

Fuel pump and the pressure regulator can be arranged. Further, the fuel supply system may comprise a suction jet pump, the

Tank with fuel from the fuel tank fills.

The fuel pump can be designed as an electric fuel pump (EKP). The fuel pump has a brushless, in particular electrically commutated motor. The engine can, for example, as a brushless

DC motor (Brushless DC motor, BLDC) be executed. The engine is in there to avoid a brush or Kohleabrieb, without a mechanical commutator. Thus, an abrasion of

Commutation avoided and the hydraulically possibly arranged directly after the fuel pump pressure regulator is protected from contamination.

The filter, also referred to as the main fuel filter, may be used as a fine filter, i. be executed fine-meshed filter. Furthermore, the filter may be a lifetime filter. That is, the filter may be configured to be maintenance-free over the life of, for example, a motor vehicle. The filter can hydraulically between the fuel pump and the internal combustion engine or the

Be arranged injection system of the internal combustion engine. In particular, the filter is downstream of the pressure regulator and upstream of the pressure regulator

Internal combustion engine or the injection system arranged. The pressure regulator is arranged hydraulically between the fuel pump and the filter. In other words, the pressure regulator is located downstream of the fuel pump and upstream of the filter. The pressure regulator is arranged inside the fuel tank. In particular, the pressure regulator can be integrated into a housing of the fuel pump and can be arranged hydraulically between the pressure regulator and the fuel pump or.

The pressure regulator is designed to regulate a system pressure of the fuel. For example, rules can mean that the pressure on the

Burning machine side of the pressure regulator is limited to the top. Further, the pressure regulator may be configured to have a minimum desired pressure value on the

To ensure fuel tank side of the pressure regulator. The pressure regulator may e.g. be designed as a mechanical valve, for example, an overpressure or an emergency valve. For example, can the pressure regulator as a spring ring combination

and / or throttle.

In particular, the pressure regulator can take over an overpressure function in the parking and emergency case. That is, for example, in case of failure of the rest

Control units or in a hot shutdown of a vehicle, the pressure regulator can be executed, a system pressure between the

Electric fuel pump and the pressure regulator above a minimum setpoint hold. The fuel supply system can be used as controlled or

be executed regulated system in which the pressure regulator specifies an upper or lower pressure limit, the actual system pressure is adjusted by means of the control unit.

According to one embodiment of the invention, the

Fuel supply system on a control unit that with the

Fuel pump is connected. The control unit is designed to regulate the system pressure of the fuel via a rotational speed of the engine of the fuel pump.

The control unit can be connected bidirectionally with the fuel pump. That is, the control unit can on the one hand signals and measured values, such. receive the current rotational speed of the engine of the fuel pump and on the other hand send control signals to the fuel pump.

According to a further embodiment of the invention, the

Fuel supply system to a pressure sensor, which is arranged between the filter and the internal combustion engine. The pressure sensor is executed, a current system pressure of the fuel, in particular one of the

Determine pressure regulator from the engine side current pressure. The control unit is designed to regulate the system pressure as a function of the current system pressure. The pressure sensor may be designed to transmit the determined current system pressure value to the control unit. The control unit may compare the determined current system pressure with a system pressure set point and regulate the system pressure, for example, by increasing or decreasing the rotational speed of the engine of the fuel pump. If the currently determined system pressure is lower than the setpoint value specified or stored, for example, in the control unit, then the fuel pump can be controlled to run faster or to pump a larger amount of fuel. If the currently determined system pressure is higher than the predetermined desired value, then the control unit can

Control fuel pump, to promote less fuel per unit time.

According to an embodiment of the invention, the system further comprises an injection device connected between the pressure regulator and the internal combustion engine is arranged on. In particular, the injection device between the filter and the internal combustion engine is arranged directly in front of the internal combustion engine. Furthermore, a functionality sensor is arranged on the injection device and designed to determine a functionality value of the injection device. The control unit is executed, the system pressure as a function of

Functionality value of the injector to regulate.

The functionality sensor can determine, for example, whether the

Burning machine or the injector sufficient fuel is available. If the functionality sensor detects, for example, an undersupply of fuel, then a functionality value is communicated to the control unit, which signals the fuel supply to the internal combustion engine. The control unit can in this case control the fuel pump to pump faster or to promote more fuel and the changed

Save demand characteristic. In other words, the

Functional sensor, for example, when the injection system is no longer optimally operated.

The fuel supply system can be several pressure and / or

Have functionality sensors. Both a print and a

Functionality sensor can be arranged for example on the injection system or between the injection system and the filter. The fuel supply system is designed as a regulated system. Thanks to this configuration of the fuel supply system is the

System pressure of the fuel between the filter and the internal combustion engine is not set directly via the pressure regulator, but via the control unit by controlling the fuel pump. In this way, despite the location of the pressure regulator upstream of the filter, the desired system pressure can be adjusted, even though the filter has a varying pressure drop throughout its life. In this way, the pressure sensor can only fulfill the function of maintaining a minimum pressure on the side of the fuel pump. This can ensure that e.g. in the event of a hot drop of a vehicle or failure of the vehicle

Control unit a minimum pressure is maintained and the fuel does not over-degas. According to one embodiment of the invention, the fuel supply system is arranged in a fuel tank.

According to one embodiment of the invention, the filter is designed as a lifetime fine filter. The design as a lifetime filter means that the filter is installed directly in the fuel tank and can remain in the fuel tank without high service costs for the life of the motor vehicle. Alternatively, the filter may be designed as a replaceable filter. In this case, the filter may be located outside of the fuel tank and easily replaceable. This is particularly useful in motor vehicles that are used in countries with a high degree of contamination of the fuel makes sense.

The execution of the filter as a fine filter can mean, for example, that the filter is fine-meshed compared to a component pre-filter, such as

for example, a fuel pump pre-filter is executed. For example, the mesh of a fine filter may be smaller by a factor of 10 to 15

Diameter or in their dimensions, as the one

Komponentenvorfilters. For example, the mesh size of a

Component prefilter at about 50 to 60 μηη lie. The mesh size of a fine filter may be e.g. 5 to 8 μηη amount.

According to a second aspect of the invention, there is provided a method of operating a fuel delivery system as shown above. The

The procedure involves the following steps: Determining a current one

System pressure of a fuel by means of a pressure sensor; Control of a system pressure depending on the current system pressure by a

Control unit.

According to a third aspect of the invention, there is provided a method of operating a fuel delivery system as shown above. The

The method comprises the following steps: determining a functionality value of an injection device by means of a functionality sensor at the

Injector; Rules of a system pressure depending on

Functionality value by the control unit. Other features and advantages of the present invention will become

Expert from the following description of exemplary

Embodiments, which should not be construed as limiting the invention, with reference to the accompanying drawings.

Fig. 1 shows known embodiments of a fuel supply system

Fig. 2 shows a hydraulic diagram of the embodiment of

Fuel supply system in a motor vehicle according to a first embodiment of the invention

Fig. 3 is a hydraulic diagram of the configuration of the fuel supply system according to a second embodiment of the invention

Fig. 4 is a hydraulic diagram of the configuration of the fuel supply system according to a third embodiment of the invention

All figures are merely schematic representations of devices according to the invention or of their components according to embodiments of the invention. In particular, distances and size relationships are not shown to scale in the figures. In the various figures, corresponding elements are provided with the same reference numbers.

FIGS. 1A to 1D show known versions of fuel supply systems in a hydraulic diagram. The pressure regulator 11 'is arranged in the known embodiments after the filter 7'. Figs. 1A and 1B show an embodiment without a return of the fuel, and Figs. IC and 1D show an embodiment of the system with a fuel return 37 '. In Figs. IC and 1D, an excess amount of the delivered fuel is used to drive a suction jet pump 35 '. In FIGS. 1A and 1C, the filter 7 'is designed as a service life filter in the fuel tank. In Figs. 1B and 1D, the filter 7 'is an exchangeable external filter e.g. for countries with a low degree of purity of the fuel (so-called bad fuel countries).

The arrangement of the pressure regulator 11 'after the filter 7' requires some additional effort, for example, when installing the pressure regulator 7 '. this will especially in the configuration with an external, that is arranged outside of the fuel tank filter 7 'clearly. As shown in FIGS. 1B and 1D, in an externally mounted filter 7 'is an additional

Hoses between the external filter 7 'and the fuel tank necessary. Furthermore, the defined positioning of the pressure regulator 11 'in front of the filter 7' is a restriction in a space-optimized design of the fuel supply system.

A known alternative, which is not shown in the figures, is the

Execution of a prefilter 23 'of the fuel pump 5' with a fine filter function.

In this alternative, however, a hot gasoline functionality of the

Fuel pump 5 'be limited by the small mesh size. Furthermore, in such a configuration, abrasion of commutation of the fuel pump can not be kept away from the pressure regulator 11 '. The pre-filter 25 can pollute in this case and by an increased pressure drop a

Negatively affect the pressure regulator characteristic.

In Figs. 2 to 4 hydraulic schemes are improved

inventive design of the fuel supply system 1 shown. In this case, the pressure regulator 11 is hydraulically in front of the filter 7,

arranged in particular in front of the main or fine filter. Further, in the

Fuel supply system 1, a fuel pump 5 with a brushless commutated motor 13 (BLDC-EKP) used. By the use of the brushless commutated motor 13 is no brush or

Kommutierungskohleabrieb, the pressure regulator 11 and a pre-filter 25 of the

Can pollute pressure regulator. By arranging the pressure regulator 11 in front of the filter 7, a space optimization of the fuel supply system 1 is made possible. Furthermore, the cost and the work involved in

Embodiments with external filters 7 can be reduced, for example by the elimination of additional hydraulic lines.

As shown in FIG. 2, the fuel supply system 1 is at least partially disposed in a fuel tank 27. The fuel supply system 1 is designed to supply an internal combustion engine 3 with fuel 9 via an injection device 21. In the fuel tank 27, a storage pot 31 is provided in which by means of a suction jet pump 35 fuel 9th is accumulated. The fuel 9 is conveyed from the storage pot to the injection device 21 or to the internal combustion engine 3 with the aid of a fuel pump 5, which is designed as an electric fuel pump with a brushlessly commutated motor 13.

The fuel pump 5 is arranged in the storage pot 31. Downstream of the fuel pump 5, the pressure regulator 11 is arranged. Upstream from

Pressure regulator 11, a pre-filter 25 may be provided which keeps larger particles from the fuel 9 from the pressure regulator 11. Downstream of the pressure regulator 11, the filter 7 is arranged. The filter 7 is designed as a main or fine filter and cleans the internal combustion engine 3 supplied fuel 9 of larger and smaller unwanted particles.

The pressure regulator 11 is designed to regulate a system pressure of the fuel 9. In particular, the pressure regulator 11 can assume an overpressure function in the emergency stop emergency position. That is, the pressure regulator 11 may in case of failure of a control unit 15 or at a hot shutdown of the vehicle

Prevent excessive outgassing of the fuel 9 thereby that it maintains a minimum pressure in the fuel tank 27 in particular on the part of the fuel pump 5 and ensures that the minimum pressure is not exceeded.

In the fuel supply system 1 according to the invention, the pressure of the fuel 9 provided to the internal combustion engine 3 or the injection device 21 is not necessarily regulated by the pressure regulator 11 but by means of a control unit 15 which can regulate, for example, a rotational speed of the motor 13 of the fuel pump 5. For this purpose, the

Control unit 15 determine a systemd jerk-specific value and depending on this value, the fuel pump 5 control. Of the

System pressure-specific value can be determined, for example, by means of a pressure sensor 17, which is arranged hydraulically between the filter 7 and the injection device 21. Alternatively, the system pressure-specific value can be determined with the aid of a functionality sensor 19 which is arranged on the injection device 21. If, for example, an under-current pressure is determined by the pressure sensor 17 or, alternatively, a non-optimal functionality of the injection device 21 is determined by the functionality sensor 19, the control unit 15 can increase the fuel delivery rate. The control unit 15 may be functionally connected to the injection device 21, in particular to a functionality sensor 19 on the injection device. Additionally or alternatively, the control unit 15 may be in communication with a pressure sensor 17. Furthermore, the control unit

15 be connected to the pressure regulator 11 and the fuel pump 5.

To protect against larger unwanted particles in the fuel 9, an additional pre-filter 23 may be provided in front of the fuel pump 5. Of

Further, between the pressure regulator 11 and the fuel pump 5 a

Check valve 33 may be provided to prevent unwanted backflow of the fuel 9. The components of the fuel supply system 1 can be hydraulically connected to each other by means of lines, hoses and shaft pipes. The pipes or wave pipes lead via a tank flange 29 of the fuel tank 27 to the injection device 21.

In the embodiment in Fig. 2, the filter 7 is disposed within the fuel tank 27. Further, the fuel supply system 1 is executed without a fuel return 37. In the embodiment in Fig. 3, the filter 7 is arranged as an external filter outside of the fuel tank 27. Also in Fig.

3 fuel supply system 1 is executed without a fuel return 37.

Fig. 4 shows an embodiment in which the filter 7 within the

Fuel tanks 27 is arranged. Further, the fuel supply system

1 to a fuel return 37. The fuel return 37 ensures that an excess amount of the delivered fuel 9 for operating the

Suction jet pump 35 can be used. In conclusion, it should be noted that terms such as "comprising" or the like are not intended to exclude that other elements or steps may be envisioned.Furthermore, it should be understood that "a" or "an" does not exclude a multitude It should further be noted that the reference signs in the claims should not be construed as limiting the scope of the claims.

Claims

claims

1 . Fuel supply system (1) for supplying fuel to a

Internal combustion engine (3), the fuel supply system (1) comprising a fuel pump (5) which is executed fuel (9) to a

To promote internal combustion engine (3);

a filter (7) connected between the fuel pump (5) and the

Internal combustion engine (3) is arranged, and is designed to clean the fuel to the engine (3) fuel (9) of unwanted particles;

a pressure regulator (1 1), which is executed, a system pressure of

To regulate fuel (9);

characterized in that

the fuel pump (5) has a brushlessly commutated motor (13); and that

the pressure regulator (1 1) between the fuel pump (5) and the filter (7) is arranged.

2. A fuel supply system (1) according to claim 1, further comprising a control unit (15) which is connected to the fuel pump (5); wherein the control unit (15) is executed, the system pressure of the

Fuel (9) via a rotational speed of the motor (13) of the

Regulate fuel pump (5).

3. A fuel supply system (1) according to claim 2, further comprising a pressure sensor (17),

wherein the pressure sensor (17) between the filter (7) and the

Internal combustion engine (3) is arranged;

wherein the pressure sensor (17) is adapted to determine a current system pressure of the fuel (9);

wherein the control unit (15) is executed, the system pressure in

Depending on the current system pressure. A fuel supply system (1) according to any of claims 2 and 3, further comprising

an injection device (21) between the pressure regulator (1 1) and the

Internal combustion engine (3) is arranged; and

a functionality sensor (19) that is implemented

Determine the functionality value of the injection device (21);

wherein the control unit (15) is executed, the system pressure in

Depending on the functionality of the injector (21) to regulate.

Fuel supply system (1) according to one of claims 1 to 4, wherein the fuel supply system (1) is carried out in one

Fuel tank (27) to be arranged.

Fuel supply system (1) according to one of claims 1 to 5, wherein the filter (7) is designed as a lifetime fine filter.

A method of operating a fuel supply system (1) according to any one of claims 1 to 6, the method comprising the following steps

Determining a current system pressure of a fuel (9) by means of a pressure sensor (17);

Controlling a system pressure as a function of the current system pressure by a control unit (15).

Determining a functionality value of an injection device (21) by means of a functionality sensor (19) on the injection device (21);

Control of a system pressure as a function of the functionality value by a control unit (15).