KR101677916B1 - Fuel injection device - Google Patents

Abstract

The present invention relates to a fuel injection device for a multi-cylinder-internal combustion engine, characterized in that it comprises an air flow (1) for supplying combustion air comprising, on the end side, separate flow channels (17) A first group of fuel injection valves 19 for directly injecting fuel into each cylinder 11 and a second group of fuel injection valves 20 for injecting fuel into the flow channels 17, Group < / RTI > In order to reduce the manufacturing cost of the fuel injector with weight reduction and system simplification, a second group of fuel injection valves 20 is provided with a multi-jet-injector 20 which simultaneously injects at least two separate fuel jets 24, Is formed as valves 26 and 27 and the fuel injection valves 20 are disposed in the air flow path 18 such that the injected fuel jets 24 and 25 reach the various flow channels 17.

Description

[0001] Fuel injection device [0002]

The present invention relates to a fuel injection device for a multi-cylinder internal combustion engine according to the preamble of claim 1.

A known fuel injection system, a so-called dual injection system for a four-cylinder internal combustion engine (US 2006/009 65 72 A1), comprises an air intake-manifold with an air filter, four fuel injection valves And a second group of four fuel injection valves for injecting fuel into each of the intake pipes, wherein the air intake-manifold branches at four intake pipes extending into the respective cylinders. The second group of fuel injection valves are connected to a low pressure pump for delivering fuel from the fuel tank while the first group of fuel injection valves are connected to a high pressure pump which is fueled by a low pressure pump. The two groups of fuel injection valves have different characteristics and are controlled by the electronic control unit for fuel injection to selectively perform homogeneous combustion in the cylinder in the normal operating range of the engine in accordance with the engine speed and the charging factor of the engine . In general, the first group of fuel injection valves are preferentially used and the second group of fuel injection valves are used complementarily to compensate for the shortage of injection by the first group of fuel injection valves in a particular operating range of the engine do.

A known fuel injection device for an internal combustion engine having at least two cylinders (DE 38 08 396 A1) comprises a fuel injection valve with two injection holes, and the hole axes of the injection holes form an acute angle with each other, Two fuel jets are produced which are discharged in different directions during the metering. The fuel injection is made in the suction pipe for guiding the combustion air to the combustion cylinder, and the end of the suction pipe is bent to the Y-pipe. Each leg portion of the Y-tube is connected to an inlet channel formed in the cylinder head of the internal combustion engine, and the end side of the inlet channel is closed by an inlet valve. The fuel injection valve has a tube wall of a suction pipe disposed opposite the Y-tube so that the injection hole shafts are approximately in line with the axis of the leg portion of the Y-tube and thus the fuel jets are injected into the air volume passing through the suction tube in the direction of the leg portion .

SUMMARY OF THE INVENTION It is an object of the present invention to provide a fuel injection device with reduced manufacturing cost and installation cost.

This problem is solved by a fuel injection device having the features of claim 1.

An advantage of the fuel injector according to the invention having the features of claim 1 is that it comprises a plurality of flow channels extending to different cylinders using one multi-jet-injection valve for injecting at least two fuel jets in different divergent directions A portion of the second group of fuel injection valves, which are generally used only as ancillary components, can be saved and manufacturing and installation costs for a dual injection system can be reduced. By reducing the number of fuel injection valves, weight savings and system simplification are achieved.

By the measures set forth in the other claims, the preferred embodiment and improvement of the fuel injection device set forth in claim 1 is possible.

According to a preferred embodiment of the present invention, the fuel jets of each multi-jet-injection valve are guided in the injection channels separated in sealing manner to each other up to the flow channels by the multi-jet-injection valve. This ensures that the pneumatic coupling of the flow channels is prevented by the insertion of the multi-jet-injection valve, on the one hand ensuring a precise uniform distribution of the fuel quantity to the flow channels and, on the other hand, Air leaks between the flow channels, which can result in undesired dispensing, are prevented by vibrations of the air columns in the flow channels

According to a preferred embodiment of the present invention, the air flow path includes at least one suction module, each of which has two separate suction channels forming a flow channel. A two-jet-dispensing valve accommodating chamber and two jetting channels extending into the suction channels are formed in the suction module, the jetting channels branching from the receiving chamber. The suction module is preferably embodied by injection-molding or die-casting, and the chamber and channel in the suction module can be simply molded. Since it is ensured that each fuel jet is injected into a separate flow channel which is segregated from the other flow channels after the two-jet-injection valve is placed in the receiving chamber, the fuel quantity for the two cylinders is uniformly distributed . The pneumatic coupling of the two flow channels through the injection channel and the receiving chamber can be eliminated or minimized.

The present invention is described in detail with reference to the embodiments shown in the drawings.

1 is a schematic view of a fuel injection device for a four-cylinder internal combustion engine.
2 is a longitudinal sectional view of a suction module including a two-jet-injection valve for two cylinders of an internal combustion engine and connected to the cylinder head of the internal combustion engine.
3 is a perspective view of the suction module in the direction of arrow III in Fig.

As an example of a multi-cylinder-internal combustion engine of a vehicle, a four-cylinder-internal combustion engine includes four cylinders 11, which are covered by a cylinder head 12. The cylinder head is shown in longitudinal section in Fig. 2 and restricts the combustion chamber 13 with a piston guided in the cylinder 11, not shown in each cylinder 11. The combustion chamber includes an inlet (15) controlled by an inlet valve (14). The inlet 15 forms the inlet of the inlet channel 16 through the cylinder head 12.

The fuel injection device includes an air flow path 18 for supplying combustion air to the combustion chamber 13 of the cylinder 11, a first group of fuel injection valves (not shown) for directly injecting fuel into the combustion chamber 13 of the cylinder 11 19) and a second group of fuel injection valves (20) injecting fuel into the flow channels (17), the air flow paths extending into individual inlet channels (16), the end sides of which are separate from each other Flow channels (17).

The first group of fuel injection valves 19 injecting directly into the cylinder 11 are connected to a second group of fuel injection valves 19 which receive fuel from the fuel- (20) receives fuel from the low-pressure pump (22). The fuel-low pressure pump, which is generally disposed in the fuel tank 23, supplies fuel from the fuel tank 23 to the second group of fuel injection valves 20 on the one hand and to the fuel high pressure pump 21 on the other hand . The injection timing and the injection duration of the fuel injection valves 19 and 20 are controlled by an electronic control unit incorporated in the engine control unit in accordance with the operating point of the internal combustion engine, Valves 19 are used to improve the deficiency of direct injection of fuel by the first group of fuel injection valves 19 in a particular operating range and to provide a second group of Fuel injection valves 20 are used complementarily.

The second group of fuel injection valves 20 are formed as multiple jet-injection valves for lowering the manufacturing cost of the fuel injectors, the valves simultaneously spraying at least two fuel jets that are separately offset from each other, The injected fuel jets 24, 25, which generally have a conical shape, are disposed in the air flow path 18 to reach the various flow channels. In the case of a four-cylinder internal combustion engine used as an example, two two-jet-injection valves 26 and 27 are arranged, and the injection valves are arranged such that one two-jet-injection valve 26 is connected to the first and second cylinders Jet valve 27 into the flow channel 17 extending into the second and third cylinders 11 and 11 and into the flow channel 17 extending into the third and fourth cylinders 11, . To this end, the flow channels 17 are formed to provide a mounting point for two jet-dispense valves 26 or 27 between two directly adjacent flow channels 17. Two-jet-injection valves are disclosed for example in DE 38 08 396 A1 or DE 44 20 063 A1.

In a structural embodiment of the fuel injector, the air flow path 18 includes one suction module 28 for each cylinder pair, and the suction modules each comprise two separate Suction channels 29 and 30, respectively. The suction module 28 for the pair of first and second cylinders 11 is shown in perspective view in FIG. 3 and in longitudinal section in FIG. The intake module 28 is provided with an accommodating chamber 31 for the two-jet valve 26 and two inlet channels 32, 32 starting from the accommodating chamber 31 and leading into the intake channel 29 or 30, 33 is formed and one of the fuel jets 24, 25 injected angularly offset by the two jet-injecting valves 26 inserted in the accommodating chamber 31 is guided in each inlet channel. Each injection channel 32 or 33 has an inlet 34 at the bottom of the receiving chamber 31 and an outlet 34 at the bottom of the receiving chamber 31 as shown in the longitudinal section of the suction module 28 according to FIG. And a discharge port 35 in the wall of the suction channel 29 or 30 of the compressor. The inlet and outlet ports 34 and 35 are disposed and the injection channel 32 or 33 is positioned such that each injected fuel jet 24 and 25 passes substantially through the inlet and outlet ports 34 and 35 without contacting the channel wall. . The suction module 28 is disposed in the cylinder head 12 of the internal combustion engine such that the two suction channels 29 and 30 cooperate with the respective inlet channels 16 in the cylinder head 12. [ The fixing of the suction module 28 to the cylinder head 12 is accomplished by the fixing flange 36 disposed at the downstream end of the suction module 28.

The suction module 28 formed identically is also provided for the third and fourth cylinder 11 pairs. A second two-jet-dispensing valve 27 is inserted into the receiving chamber 31 of the suction module 28.

The suction module 28 for the first and second cylinders 11 and the suction module 28 for the third and fourth cylinders 11 are connected to a suction pipe manifold not shown on the upstream side, Four suction channels 29, 30 are incorporated. An air flow regulator, such as a throttle valve, is generally disposed upstream of the integration point.

11 cylinders
17 flow channel
18 Air flow path
20 fuel injection valve
24, 25 Fuel Jet

Claims (5)

1. A fuel injection device for a multi-cylinder internal combustion engine, comprising: an air flow path (18) for supplying combustion air containing, on the end side, mutually separated flow channels (17) extending to individual cylinders (11) (20) for injecting fuel into the flow channel (17) and a first group of fuel injection valves (19) for injecting fuel directly into the flow channel (11), and a second group of fuel injection valves In this case,
The second group of fuel injection valves (20) is formed as multiple jet-injection valves (26, 27) that simultaneously inject at least two separate fuel jets (24, 25) Fuel injection valves 20 are disposed in the air flow path 18 such that injected fuel jets 24 and 25 reach different flow channels 17,
Characterized in that the fuel jets (24, 25) are guided in the injection channels (32, 33) separated in sealing manner from one another up to the flow channel (17) by multiple jet-injection valves. 2. A method according to claim 1, wherein in a four-cylinder internal combustion engine a second group of fuel injection valves (20) comprises two two-jet-injection valves (26, 27) Jet valve 26 is injected into the flow channel 17 extending to the first and second cylinders 11 and the other two jet-injecting valves 27 are injected into the third and fourth cylinders 11, To a flow channel (17) that extends into the flow channel (17). 2. The device of claim 1, wherein the air flow path (18) includes at least one suction module (28) having two separate suction channels (29, 30) forming respective flow channels (17) An intake chamber 31 for the two-jet valve 26 and two injection channels 32 and 33 extending to the intake channels 29 and 30 are formed in the suction module 28, And the injection channels start from the accommodation chamber (31). 4. A device according to claim 3, characterized in that each injection channel (32, 33) has an inlet (34) at the bottom of the receiving chamber (31) and an outlet (35) at the wall of each suction channel (29, 30) , Wherein the inlet and outlet (34, 35) are arranged such that the fuel jets (24, 25) pass through the inlet and outlet (34, 35) 32, and 33 are formed in the fuel passage.
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