WO2015014529A1

WO2015014529A1 - Fuel injection system

Info

Publication number: WO2015014529A1
Application number: PCT/EP2014/062386
Authority: WO
Inventors: Martin RIEGEL; Jan Kafka
Original assignee: Robert Bosch Gmbh
Priority date: 2013-07-31
Filing date: 2014-06-13
Publication date: 2015-02-05
Also published as: BR112016001797A2; CN105431625A; EP3027878A1; DE102013214960A1

Abstract

A fuel injection system (1) which serves for intake pipe injection of natural gas in internal combustion engines (2) comprises multiple injection valves (28, 28A, 28B). In this case, a fuel-conducting connecting means (10), a first injection unit (3) and at least one second injection unit (4) are provided. The injection valves (28, 28A, 28B) are integrated into the injection units (3, 4). Furthermore, the first injection unit (3) has an inlet port (26) for the fuel and an outlet port (27) for the fuel. The second injection unit (4) has at least one inlet port (26A) for the fuel. The connecting means (10) connects the outlet port (27) of the first injection unit (3) to the inlet port (26A) of the second injection unit (4). In this case, a modular construction is made possible by means of possible variants of the injection units (3, 4).

Description

Description title

Fuel injection system prior art

The invention relates to a fuel injection system, in particular for

Intake manifold injection of natural gas in internal combustion engines is used. Specifically, the invention relates to the field of fuel injection systems having a plurality of injectors that inject into intake manifolds of a gasoline or diesel engine, wherein the natural gas is supplied in compressed form as CNG.

From DE 10 2010 064 115 A1 an injector arrangement is known, which preferably serves for natural gas. The known injector assembly has a fuel rail, which serves to distribute compressed natural gas to a plurality of injectors. At the

Fuel manifold is mounted a connector to which, for example, via a piping, a fuel tank is connected. The fuel tank may serve for storing natural gas, in particular compressed natural gas (CNG). Further, a sensor is mounted to the fuel rail, which serves for example for measuring the pressure and the temperature of the natural gas in the fuel rail.

The known from DE 10 2010 064 1 15 A1 injector has the disadvantage that it is designed for a specific application. Among other things, the distances between the injectors are fixed. In addition, claimed by the fuel rail and the structural design of the injector a considerable amount of space that must be made available in the engine compartment. In addition, a large number of individual parts must be connected to each other during assembly of the injector. Disclosure of the invention

The fuel injection system according to the invention with the features of claim 1 has the advantage that an improved structure and in particular a greater flexibility are possible. Specifically, a simple adaptation to different applications can be realized by a modular design.

The measures listed in the dependent claims are advantageous

Further developments of the fuel injection system specified in claim 1 possible.

The fuel injection system is preferably for distributing and injecting natural gas via the injection units. Specifically, the fuel injection system can serve here for port injection of natural gas in internal combustion engines. The

Fuel injection system is also suitable for mixed operation in one

Internal combustion engine, for example, an operation with gasoline and natural gas is possible. The fuel injection system can be used in gasoline or diesel engines. The natural gas is preferably supplied to the fuel injection system as compressed natural gas. For example, the natural gas may be compressed at a pressure of about 20 MPa (200 bar). Such a compressed natural gas is also called CNG. The concept of natural gas, however, is not limited to natural gas but is generally understood. For example, the natural gas can also be artificially

Be obtained coal gasification. Thus, under the term natural gas are also

to understand natural gas-like fuels.

The injectors are advantageously integrated in the injection units. For example, in an injection unit having both an input port for the fuel and an output port for the fuel, the fuel may be guided through an internal space inside the injection unit. From this interior can then according to the injection processes required by the injection valve

Be taken fuel. However, the fuel may also be conducted via a channel through the injection unit, wherein, for example via a tee, fuel is diverted from the channel between the inlet port and the outlet port for the injection valve of the injection unit.

It is advantageous that a plurality of injection units are provided, that the

Injectors are integrated into the injection units and that the injection units are interconnected by the at least one connecting means. Here, according to the number of injection units, the required number of connecting means is used. As a result, a modular construction is made possible because each injection unit, which has both an inlet port and an outlet port, a further injection unit can be connected via a connecting means. In this case, it is also advantageous that the injection units are successively connected to one another via the connection means, which connect two injection units in each case, and / or that an injection unit has only one input connection. Thus, a chain of injection units can be formed in which exactly one

Injection unit, namely the last injection unit in the chain, only one

Having input terminal. Here, two such chains may be arranged parallel to each other on the internal combustion engine, which are supplied together or separately with fuel. As a result, adjustments to the structural design of the

Internal combustion engine possible. Possible application examples are boxer engines with four or six cylinders and engines with V-arrangement of the cylinders. However, in this case also a correspondingly long chain can be formed over a longer connecting means, which then runs, for example, in a U-shape.

It is advantageous that at least one connecting means is designed as a flexible connecting means, which is bendable at least during assembly. This can be the

Connecting means, for example, from a suitably selected metal and with a suitable configuration, in particular wall thickness, be formed to allow during assembly by bending trimming. Bending can then preferably take place in a preparatory assembly step, wherein adaptation to the specific application is possible. However, it is also advantageous that the connecting means is designed as a flexible connecting means. Thus, a mounting according to a modular structure can be realized in a particularly simple manner. The flexibility of the connecting means can be achieved by a geometric design and / or by a suitable choice of material. In particular, the connecting means may be formed in an advantageous manner as a tubular connecting means. Depending on

Use case can be used in assembling the fuel injection system at different locations and different connecting means used. In this case, it is conceivable, for example, that a flexible or flexible connection means is used only at a location where bending of the connection means is also required. This can possibly be saved material costs.

It is also advantageous that the input terminal of an injection unit and the connection means fastened to the input terminal are designed such that a

Tolerance compensation between the input terminal and the connecting means is made possible. In particular, a tolerance compensation for the assembly can be ensured here. As a result, the attachment of the injection units to the

Internal combustion engine facilitates. In a corresponding manner, it is advantageous that the Output terminal of an injection unit and attached to the output terminal connecting means are designed so that a tolerance compensation between the

Output terminal and the connecting means is enabled. Thus, even with injection units, which have an output port for the fuel, a tolerance compensation with respect to the output terminal can be ensured. However, especially with a successive arrangement of the injection units, it may be sufficient that only at the input connections or the output connections of the successive injection units such a tolerance compensation is made possible.

Accordingly, such a tolerance compensation may optionally be provided on individual or only on an injection unit, if this is sufficient and appropriate for the specific application.

Moreover, it is advantageous that at least one injection unit has a sensor and that the sensor has a pressure and / or a temperature of the fuel in the

Injection unit measures. Thus, by the sensor, a pressure and / or temperature sensor can be realized, which is integrated in the injection unit. This simplifies assembly, since the number of components to be assembled is reduced. Furthermore, this can have an advantageous effect on the required installation space, since a flexibility with respect to the arrangement of the sensor in a chain or series of successive injection units is made possible. It is also advantageous here that an electrical connection for the sensor is integrated in a housing of the injection unit which has the sensor.

Furthermore, it is advantageous that the injection unit has a housing into which an electrical connection for the associated connection valve is integrated. If the

Injection unit is then attached to the internal combustion engine, then at the same time the electrical connection for the injection valve of the injection unit is fixed. The assembly of the electrical connection lines from a control unit to the injection units or the injection valves is then particularly simple. The input connection for the fuel and optionally the output connection for the fuel can also be integrated into the housing in an advantageous manner.

Advantageously, the housing of an injection unit may be at least partially formed by a plastic extrusion. Further, it is possible that the housing is at least partially formed by plastic parts welded together. In particular, a reliable connection with metallic parts can be realized by plastic extrusion. Brief description of the drawings

Preferred embodiments of the invention are explained in more detail in the following description with reference to the accompanying drawings, in which corresponding elements are provided with corresponding reference numerals. Show it:

1 shows a fuel injection system and an internal combustion engine in a partial, spatial representation according to a possible embodiment of the invention. Fig. 2 is an injection unit of the fuel injection system shown in Fig. 1 according to a first embodiment of the invention;

Fig. 3 is an injection unit of the fuel injection system shown in Fig. 1 according to a second embodiment of the invention;

Fig. 4 is an injection unit of the fuel injection system shown in Fig. 1 according to a third embodiment of the invention and

Fig. 5 is an injection unit of the fuel injection system shown in Fig. 1 according to a fourth embodiment of the invention.

Embodiments of the invention

Fig. 1 shows a fuel injection system 1 and an internal combustion engine 2 in a partial, spatial representation according to a possible embodiment of the

Invention. The fuel injection system 1 is particularly suitable for

Natural gas injection in suction pipes of the internal combustion engine 2. The internal combustion engine 2 may be designed as a gasoline or diesel engine. The natural gas can in this case be supplied to the fuel injection system 1 in the form of CNG. However, the fuel injection system 1 of the invention is also suitable for other applications.

The fuel injection system 1 has injection units 3 to 8. Possible

Embodiments of the injection units 3 to 8 are described in more detail with reference to FIGS. 2 to 5. The fuel injection system 1 also has connecting means 9 to 14. The connecting means 9 is connected only to the injection unit 3 and designed as an inlet. Further, the injection units 3 to 8 are connected to each other via the connecting means 10 to 14. To connect in this possible embodiment clamps 15, 16. Here are for simplicity of illustration only the clamps 15, 16th characterized. The clamp 15 is used to attach the connecting means 10 to the injection unit 3. The clamp 16 serves to connect the connecting means 10 to the injection unit 4. Further, holders 17 to 22 are provided, which in the respective

Injection unit 3 to 8 are integrated. Designed as screws 23

Attachment means 23, the injection units 3 to 8 are attached via their holders 17 to 22 to the internal combustion engine 2. To simplify the illustration, in this case only the fastening means 23 is marked.

In this possible embodiment of the fuel injection system 1 are on the

Connecting means 10 to 14 each two injection units 2 to 8 connected to each other. Here, the connecting means 10 to 14 connect the injection units 3 to 8 consecutively. Thus, the injection units 3 to 8 are arranged in a row.

The connecting means 9 is formed as a flexible connecting means 9, which is bendable at least during assembly. The connecting means 9 can also be considered flexible

Connecting means 9 may be formed. The connecting means 9 to 14 may also be configured uniformly. Specifically, the connecting means 9 to 14 as

be formed tubular connecting means 9 to 14. Through a flexible

Configuration of the connecting means 9 to 14, a tolerance compensation can be made possible, which also facilitates the assembly. For example, the injection units can be 3 to 8 twisted slightly during attachment. The resulting angular misalignment between adjacent injection units 3 to 8 can then be compensated by the respectively intermediate connecting means 10 to 14. The

Connecting means 9 to 14 can thus be configured as connecting hoses 9 to 14 in an advantageous manner.

FIG. 2 shows by way of example the injection unit 3 of the one shown in FIG

Fuel injection system 1, which is designed according to a first embodiment of one of the injection units 3 to 8. The injection unit 3 has a housing 25 into which the holder 17 is integrated. Furthermore, the injection unit 3 has a

Input terminal 26 for the fuel and an output terminal 27 for the

Fuel up. The input port 26 for the fuel and the output port 27 for the fuel are integrated into the housing 25. The housing 25 can thereby be at least partially formed by plastic parts 17, 26, 27 welded together, namely the holder 17, the input connection 26 and the output connection 27, if plastics are used in this respect. The housing 25 may also be formed at least partially by a plastic extrusion. The injection unit 3 has an injection valve 28 which is integrated into the injection unit 3. Here, an electrical connection 29 is provided for the injection valve 28. The electrical connection 29 for the injection valve 28 is also integrated in the housing 25.

During assembly, the connecting means 9 is attached to the input terminal 26 and then fixed with a clamp. Accordingly, the connecting means 10 is attached during installation on the output terminal 27 and fixed by means of the clamp 15.

Furthermore, the injection unit 3 has a sensor 30 with an electrical connection 31. The sensor 30 measures a pressure and a temperature of the fuel, which is located in the injection unit 3 and is passed through the injection unit 3 or to the injection valve 28. The electrical connection 31 for the sensor 30 is integrated in the housing 25 of the injection unit 3.

The input terminal 26 and that attached to the input terminal 26

Connecting means 9 are designed so that a tolerance compensation between the input terminal 26 and the connecting means 9 is made possible. In a corresponding manner, the output terminal 27 and the connection means 10 fastened to the output terminal 27 are designed so that a tolerance compensation between the

Output terminal 27 and the connecting means 10 is made possible.

Fig. 3 shows the injection unit 4 of the fuel injection system 1 shown in Fig. 1, which is configured according to a second embodiment of the injection units 3 to 8. The injection unit 4 comprises a housing 25A, an input port 26A for the fuel, and an output port 27A for the fuel. Further, an injection valve 28A is integrated in the injection unit 4. Further, an electric

Port 29A for the injection valve 28A integrated into the housing 25A. In contrast to the first exemplary embodiment described with reference to FIG. 2, no sensor 30 is provided in the second exemplary embodiment described with reference to FIG. 2. Incidentally, the configuration of the injection unit 4 of the second corresponds

Embodiment of the embodiment of the injection unit 3 of the first

Embodiment.

Fig. 4 shows the injection unit 8 of the fuel injection system 1 shown in Fig. 1, which is configured according to a third embodiment of the injection units 3 to 8. The injection unit 8 has only one input port 26B while the output terminal 27, as provided in the first embodiment described with reference to FIG. 2, is eliminated. Furthermore, the injection unit 8 has a sensor 30B with an electrical connection 31B for the sensor 30B. The electrical connection 31 B is in this case integrated into a housing 25 B of the injection unit 8. Furthermore, the injection unit 8 has an injection valve 28B and an electrical connection 29B for the injection valve 28B. Apart from the missing output terminal 27 corresponds to the configuration of the injection unit 8 according to the third embodiment of the described with reference to FIG. 2 embodiment of the injection unit 3 according to the first embodiment.

FIG. 5 shows the injection unit 8 of the fuel injection system 1 shown in FIG. 1, which is designed according to a fourth exemplary embodiment of the injection units 3 to 8. The injection unit 8 has the input port 26B integrated with the housing 25B. As in the third described with reference to FIG. 4

Embodiment eliminates an output terminal 27, 27A. Further, in the

In contrast to the third exemplary embodiment described with reference to FIG. 4, no sensor 30B and therefore also no electrical connection 31B are provided for the sensor 30B. In one embodiment of the fuel injection system 1 is preferably exactly one injection unit 3, 8 is used, which has a sensor 30 for pressure and temperature measurement. However, multiple injection units 3, 8 can be used with a sensor 30, 30B. This may be particularly advantageous when one of the sensors 30, 30B is used for pressure measurement, while the other sensor 30, 30B is used for temperature measurement.

In order to construct the fuel injection system 1 of successive injection units 3 to 8, an injection unit 8 is preferably used as the end piece, which is formed according to the third embodiment or the fourth embodiment, which are described with reference to FIGS. 4 and 5. To reduce the

Complexity, however, it is also conceivable that at a last injection unit 3, 4, the output port 27, 28A is closed by a dummy. In a modular design, this can reduce the number of variants. The injection units 3, 4 of the first embodiment and the second

Embodiment can be used in a structure of the fuel injection system 1 as T variants with or without sensor 30. An injection unit 8 according to the third embodiment or the fourth embodiment may be an L variant with or without sensor 30B are used. Due to the available variants, namely the two T variants and the two L variants, a suitable combination can be selected with respect to the respective application in order to construct the fuel injection system 1 in a modular manner. This allows a big one

Application area with low production costs and minimal adjustment costs.

Thus, a high flexibility and a simple design adaptation to the existing space in the engine compartment, especially in a truck or a

Passenger cars to be achieved. Furthermore, lower requirements for tolerances result from the possibility of flexible connecting means 9 to 14, which connect the individual injection units 3 to 8, for example, in the form of hoses. Furthermore, for different applications a uniform design of the

Injection units 3 to 8 are used, which reduces the variant frame. Furthermore, the fuel injection system 1 can also be retrofitted hereby if necessary. As a result, a conversion to a natural gas operation is possible.

The invention is not limited to the described embodiments.

Claims

claims

1. Fuel injection system (1), which is used in particular for the intake manifold injection of natural gas in internal combustion engines (2), with a plurality of injection valves (28, 28 A, 28 B), characterized

in that a fuel-carrying connecting means (10), a first injection unit (3) and at least one second injection unit (4) are provided, that the injection valves (28, 28A, 28B) are integrated into the injection units (3, 4) Injection unit (3) having an input port (26) for the fuel and an output port (27) for the fuel, that the second injection unit (4) at least one

And the connection means (10) connects the output port (27) of the first injection unit (3) to the input port (26A) of the second injection unit (4).

2. Fuel injection system according to claim 1,

characterized,

in that a plurality of injection units (3-8) are provided, that the injection valves (28, 28A, 28B) are integrated into the injection units (3-8), and that the injection units (3-8) are replaced by the at least one connection means (10-14). connected to each other.

3. Fuel injection system according to claim 2,

characterized,

in that the injection units (3 - 8) are connected to one another in succession via the connection means (10 - 14) connecting two injection units (3-8) and / or that one injection unit (8) has only one inlet connection (26B) ,

4. Fuel injection system according to one of claims 1 to 3,

characterized,

in that the at least one connection means (9-14) is designed as a bendable connection means (9-14) which is bendable at least during assembly, and / or that the at least one connection means (9-14) is designed as flexible connection means (9-14). is formed and / or that the at least one connecting means (9 - 14) as

tubular connecting means (9-14) is formed and / or that the Connecting means (9-14) with a clamp (16) on the associated input terminal (26, 26 A, 26 B) and / or with a clamp (15) on the associated output terminal (27, 27 A) is attached.

5. Fuel injection system according to one of claims 1 to 4,

characterized,

in that the input connection (26, 26A, 26B) of at least one injection unit (3-8) and the connecting means (9-14) fastened to the input connection are designed such that a tolerance compensation between the input connection (26, 26A, 26B) and the connection means (9-14), and / or that the output terminal (27, 27A) of at least one injection unit (3-7) and the connection means (10-14) attached to the output terminal (27, 27A) are configured such that the Tolerance compensation between the output terminal (27, 27A) and the connecting means (10-14) is possible.

6. Fuel injection system according to one of claims 1 to 5,

characterized,

in that at least one injection unit (3, 8) has a sensor (30, 30B) and that the sensor (30, 30B) has a pressure and / or a temperature of the fuel in the

Injection unit (3, 8) measures.

7. Fuel injection system according to claim 6,

characterized,

an electrical connection (31, 31 B) for the sensor (30, 30B) is integrated in a housing (25, 25B) of the injection unit (3, 8) which has the sensor (30, 30B).

8. Fuel injection system according to one of claims 1 to 7,

characterized,

in that the injection units (3 - 8) each have a housing (25, 25A, 25B) into which an electrical connection (29, 29A, 29B) for the respective injection valve (28, 28A, 28B) is integrated.

9. Fuel injection system according to one of claims 1 to 8,

characterized,

in that the injection units (3 - 8) each have a housing (25, 25A, 25B) into which the input connection (26, 26A, 26B) for the fuel or the

Output terminal (27, 27A) for the fuel and / or a holder (17 - 22) are integrated.

10. Fuel injection system according to one of claims 7 to 9,

characterized,

in that the housing (25, 25A, 25B) is formed at least partially by a plastic extrusion coating and / or that the housing (25, 25A, 25B) is formed at least partially by plastic parts (17, 26, 26A, 26B, 27, 27A) welded together is.