DE102013214960A1 - fuel injection system - Google Patents

Abstract

A fuel injection system (1) for porting natural gas to internal combustion engines (2) includes a plurality of injectors (28, 28A, 28B). In this case, a fuel-carrying 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). Further, the first injection unit (3) has an input port (26) for the fuel and an output port (27) for the fuel. The second injection unit (4) has at least one input port (26A) for the fuel. 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). This is possible by possible variants of the injection units (3, 4) a modular design.

Description

State of the art

The invention relates to a fuel injection system, which is used in particular for the intake manifold injection of natural gas in internal combustion engines. 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 the 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. On the fuel rail, a connector is mounted to which a fuel tank is connected, for example via a piping. 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 from the DE 10 2010 064 115 A1 known injector arrangement 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 advantageous developments of the fuel injection system specified in claim 1 are 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 a mixed operation in an 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 obtained artificially by coal gasification. Thus, the term natural gas and natural gas-like fuels are to be understood.

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, the fuel required by the injection valve can then be removed in accordance with the injection processes. 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 injection valves are integrated into the injection units and that the injection units are connected to each other 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 connected to one another in succession 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, has only one input port. 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. In this case, the connecting means may for example be formed from a suitably selected metal and with a suitable configuration, in particular wall thickness, in order to allow trimming during assembly by bending. 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 the application, when connecting the fuel injection system at different locations and different connecting means formed from each other can be 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 connecting 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 is facilitated. In a corresponding manner, it is advantageous that the output connection of an injection unit and the connection means fastened to the output connection are configured in such a way that a tolerance compensation between the output connection and the connection means is made possible. 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 measures a pressure and / or a temperature of the fuel in the injection unit. 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 a fuel injection system and an internal combustion engine in an extract, spatial representation according to a possible embodiment of the invention;

2 an injection unit of in 1 illustrated fuel injection system according to a first embodiment of the invention;

3 an injection unit of in 1 illustrated fuel injection system according to a second embodiment of the invention;

4 an injection unit of in 1 illustrated fuel injection system according to a third embodiment of the invention and

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

Embodiments of the invention

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 intake manifolds of the internal combustion engine 2 , The internal combustion engine 2 can be configured as a gasoline or diesel engine. The natural gas can be in the form of CNG the fuel injection system 1 be supplied. The fuel injection system 1 However, the invention is also suitable for other applications.

The fuel injection system 1 has injection units 3 to 8th on. Possible embodiments of the injection units 3 to 8th are based on the 2 to 5 described in more detail. The fuel injection system 1 also has connecting means 9 to 14 on. The connecting means 9 is only with the injection unit 3 connected and designed as an inlet. Further, the injection units 3 to 8th over the connecting means 10 to 14 connected with each other. To connect serve in this possible embodiment clamps 15 . 16 , In this case, to simplify the illustration, only the clamps 15 . 16 characterized. The clamp 15 serves for fastening the connecting means 10 at the injection unit 3 , The clamp 16 serves to connect the connecting means 10 at the injection unit 4 , Further, holders are 17 to 22 provided in the respective injection unit 3 to 8th are integrated. Over as screws 23 designed fasteners 23 are the injection units 3 to 8th about their holders 17 to 22 on the internal combustion engine 2 attached. To simplify the illustration here is only the fastener 23 characterized.

In this possible embodiment of the fuel injection system 1 are about the lanyards 10 to 14 two injection units each 2 to 8th connected with each other. Here connect the connecting means 10 to 14 the injection units 3 to 8th consecutive. Thus, the injection units 3 to 8th arranged in a row.

The connecting means 9 is as a flexible connection means 9 formed, which is bendable at least during assembly. The connecting means 9 Can also be used as a flexible lanyard 9 be educated. The connecting means 9 to 14 can also be designed uniformly. Specifically, the connecting means 9 to 14 as a tubular connecting means 9 to 14 be educated. By a flexible design of the connecting means 9 to 14 a tolerance compensation can be made possible, which also facilitates the assembly. For example, the injection units 3 to 8th be slightly twisted during attachment. The resulting angular offset between adjacent injection units 3 to 8th can then through the respective intermediate connecting means 10 to 14 be compensated. The connecting means 9 to 14 can thus advantageously as connecting hoses 9 to 14 be designed.

2 shows an example of the injection unit 3 of in 1 illustrated fuel injection system 1 , which according to a first embodiment for one of the injection units 3 to 8th is designed. The injection unit 3 has a housing 25 in, in which the holder 17 is integrated. Furthermore, the injection unit 3 an input terminal 26 for the fuel and an output port 27 for the fuel. The input connection 26 for the fuel and the output connection 27 for the fuel are in the case 25 integrated. The housing 25 can thereby at least partially by welded together plastic parts 17 . 26 . 27 namely the holder 17 , the input terminal 26 and the output terminal 27 be formed when plastics are used in this respect. The housing 25 can also be formed at least partially by a plastic extrusion.

The injection unit 3 has an injection valve 28 on that in the injection unit 3 is integrated. Here is an electrical connection 29 for the injection valve 28 intended. The electrical connection 29 for the injection valve 28 is also in the case 25 integrated.

During assembly, the connecting means 9 on the input connection 26 attached and then fixed with a clamp. Accordingly, when mounting on the output terminal 27 the connecting means 10 attached and by means of the clamp 15 fixed.

Furthermore, the injection unit 3 a sensor 30 with an electrical connection 31 on. The sensor 30 measures a pressure and a temperature of the fuel that is in the injection unit 3 located and through the injection unit 3 or to the injection valve 28 to be led. The electrical connection 31 for the sensor 30 is in the case 25 the injection unit 3 integrated.

The input connection 26 and that at the input port 26 fastened connecting means 9 are designed so that a tolerance compensation between the input terminal 26 and the connecting means 9 is possible. Similarly, the output terminal 27 and that at the output port 27 fastened connecting means 10 designed so that a tolerance compensation between the output terminal 27 and the connecting means 10 is possible.

3 shows the injection unit 4 of in 1 illustrated fuel injection system 1 , According to a second embodiment of the injection units 3 to 8th is designed. The injection unit 4 has a housing 25A , an input terminal 26A for the fuel and an output port 27A for the fuel. Further, an injection valve 28A in the injection unit 4 integrated. Furthermore, an electrical connection 29A for the injection valve 28A in the case 25A integrated. In contrast to the basis of the 2 described first embodiment is in the basis of the 2 described second embodiment no sensor 30 intended. Incidentally, the configuration of the injection unit corresponds 4 of the second embodiment of the embodiment of the injection unit 3 of the first embodiment.

4 shows the injection unit 8th of in 1 illustrated fuel injection system 1 , According to a third embodiment of the injection units 3 to 8th is designed. The injection unit 8th has only one input port 26B on while the output connector 27 as he is based on the 2 is provided described first embodiment is omitted. Furthermore, the injection unit 8th a sensor 30B with an electrical connection 31B for the sensor 30B on. The electrical connection 31B is here in a housing 25B the injection unit 8th integrated. Furthermore, the injection unit 8th an injection valve 28B and an electrical connection 29B for the injection valve 28B on. Apart from the missing output connection 27 corresponds to the configuration of the injection unit 8th according to the third embodiment of the reference to the 2 described embodiment of the injection unit 3 according to the first embodiment.

5 shows the injection unit 8th of in 1 illustrated fuel injection system 1 , According to a fourth embodiment of the injection units 3 to 8th is designed. The injection unit 8th indicates the input connection 26B on that in the case 25B is integrated. As with the basis of the 4 described third embodiment, this eliminates an output terminal 27 . 27A , Furthermore, in contrast to the basis of the 4 described third embodiment no sensor 30B and thus no electrical connection 31B for the sensor 30B intended.

In one embodiment of the fuel injection system 1 is preferably exactly one injection unit 3 . 8th to use that a sensor 30 for pressure and temperature measurement. However, you can also use multiple injection units 3 . 8th with a sensor 30 . 30B be used. This can be particularly advantageous if one of the sensors 30 . 30B for pressure measurement, while the other sensor 30 . 30B used for temperature measurement.

To the fuel injection system 1 from successive injection units 3 to 8th build, preferably comes as an end piece an injection unit 8th For use, according to the third embodiment or the fourth embodiment, based on the 4 and 5 are described, is formed. However, to reduce complexity, it is also conceivable that at a last injection unit 3 . 4 the output terminal 27 . 28A is closed by a blank. In a modular design, this can reduce the number of variants.

The injection units 3 . 4 of the first embodiment and the second embodiment may be in a structure of the fuel injection system 1 as T variants with or without sensor 30 be used. An injection unit 8th according to the third embodiment or the fourth embodiment, as L-variant with or without sensor 30B be used. Due to the available variants, namely the two T-variants and the two L-variants, a suitable combination can be selected in relation to the respective application to the fuel injection system 1 build modular. This allows a wide range of applications with low production costs and minimal adaptation costs.

Thus, a high flexibility and a simple design adaptation to the existing space in the engine compartment, in particular in a truck or a passenger car, can be achieved. Furthermore, lower requirements for tolerances result from the possibility of being more flexible connecting means 9 to 14 containing the individual injection units 3 to 8th connect, for example, in the form of hoses. Furthermore, for different applications, a uniform design of the injection units 3 to 8th be used, which reduces the variant frame. Furthermore, the fuel injection system 1 This may also be retrofitted. As a result, a conversion to a natural gas operation is possible.

The invention is not limited to the described embodiments.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102010064115 A1 [0002, 0003]

Claims (10)

Fuel injection system ( 1 ), in particular for the intake manifold injection of natural gas in internal combustion engines ( 2 ), with several injection valves ( 28 . 28A . 28B ), characterized in that a fuel-conducting 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 ) into the injection units ( 3 . 4 ) are integrated, that the first injection unit ( 3 ) an input terminal ( 26 ) for the fuel and an output terminal ( 27 ) for the fuel, that the second injection unit ( 4 ) at least one input terminal ( 26A ) for the fuel and that the connecting means ( 10 ) the output terminal ( 27 ) of the first injection unit ( 3 ) with the input terminal ( 26A ) of the second injection unit ( 4 ) connects. Fuel injection system according to claim 1, characterized in that a plurality of injection units ( 3 - 8th ) are provided, that the injection valves ( 28 . 28A . 28B ) into the injection units ( 3 - 8th ) and that the injection units ( 3 - 8th ) by the at least one connecting means ( 10 - 14 ) are interconnected. Fuel injection system according to claim 2, characterized in that the injection units ( 3 - 8th ) via the connecting means ( 10 - 14 ), each containing two injection units ( 3 - 8th ), are connected to each other in succession and / or that an injection unit ( 8th ) only one input terminal ( 26B ) having. Fuel injection system according to one of claims 1 to 3, characterized in that the at least one connecting means ( 9 - 14 ) as a flexible connecting means ( 9 - 14 ) is formed, which is bendable at least during assembly, and / or that the at least one connecting means ( 9 - 14 ) as a flexible connection means ( 9 - 14 ) is formed and / or that the at least one connecting means ( 9 - 14 ) as a tubular connecting means ( 9 - 14 ) is formed and / or that the connecting means ( 9 - 14 ) with a clamp ( 16 ) at the associated input terminal ( 26 . 26A . 26B ) and / or with a clamp ( 15 ) at the associated output terminal ( 27 . 27A ) is attached. Fuel injection system according to one of claims 1 to 4, characterized in that the input terminal ( 26 . 26A . 26B ) at least one injection unit ( 3 - 8th ) and the connection means attached to the input terminal ( 9 - 14 ) are designed so that a tolerance compensation between the input terminal ( 26 . 26A . 26B ) and the connecting means ( 9 - 14 ) and / or that the output terminal ( 27 . 27A ) at least one injection unit ( 3 - 7 ) and the at the output terminal ( 27 . 27A ) fastened connection means ( 10 - 14 ) are designed so that the tolerance compensation between the output terminal ( 27 . 27A ) and the connecting means ( 10 - 14 ) is possible. Fuel injection system according to one of claims 1 to 5, characterized in that at least one injection unit ( 3 . 8th ) a sensor ( 30 . 30B ) and that the sensor ( 30 . 30B ) a pressure and / or a temperature of the fuel in the injection unit ( 3 . 8th ) measures. Fuel injection system according to claim 6, characterized in that in a housing ( 25 . 25B ) of the injection unit ( 3 . 8th ), the sensor ( 30 . 30B ), an electrical connection ( 31 . 31B ) for the sensor ( 30 . 30B ) is integrated. Fuel injection system according to one of claims 1 to 7, characterized in that the injection units ( 3 - 8th ) one housing each ( 25 . 25A . 25B ) into which an electrical connection ( 29 . 29A . 29B ) for the respective injection valve ( 28 . 28A . 28B ) is integrated. Fuel injection system according to one of claims 1 to 8, characterized in that the injection units ( 3 - 8th ) one housing each ( 25 . 25A . 25B ) into which the input terminal ( 26 . 26A . 26B ) for the fuel or the output connection ( 27 . 27A ) for the fuel and / or a holder ( 17 - 22 ) are integrated. Fuel injection system according to one of claims 7 to 9, characterized in that the housing ( 25 . 25A . 25B ) is at least partially formed by a plastic extrusion and / or that the housing ( 25 . 25A . 25B ) at least partially by plastic parts welded together ( 17 . 26 . 26A . 26B . 27 . 27A ) is formed.

Images