KR20110086713A - Fuel injection device - Google Patents

Abstract

FIELD OF THE INVENTION The present invention relates to a fuel injection device for a multicylinder-internal combustion engine, the device comprising an air flow for supplying combustion air comprising at its end side separate flow channels (17) extending to an individual cylinder (11). A first group of fuel injection valves 19 for injecting fuel directly into each cylinder 11 and a second of fuel injection valves 20 for injecting fuel into the flow channel 17. It includes a dual injection unit with a group. In order to reduce the cost of manufacturing the fuel injector together with weight reduction and system simplification, the second group of fuel injection valves 20 is a multi-jet injection that injects at least two separate fuel jets 24, 25 simultaneously. Formed as valves 26, 27, the fuel injection valves 20 are disposed in the air flow path 18 such that the injected fuel jets 24, 25 reach the various flow channels 17.

Description

Fuel injection device

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

The known fuel injection system, the so-called dual-injection system for four-cylinder internal combustion engines (US 2006/009 65 72 A1) is an air intake-manifold with air filter, four fuel injection valves that directly inject fuel into each cylinder. And a second group of four fuel injection valves for injecting fuel into each intake tube, wherein the air intake-manifold branches in four intake tubes extending into each cylinder. The second group of fuel injection valves are connected to a low pressure pump that delivers fuel from the fuel tank, while the first group of fuel injection valves are connected to a high pressure pump that is fueled by the low pressure pump. The two groups of fuel injection valves have different characteristics and are controlled by the electronic control unit for fuel injection so that homogeneous combustion is carried out in the cylinder in the normal operating range of the engine, depending on the engine speed and the filling factor of the engine. . In general, the first group of fuel injection valves is used preferentially, and the second group of fuel injection valves is complementarily used to compensate for the shortage of injection by the first group of fuel injection valves in a particular operating range of the engine. .

Known fuel injection devices for internal combustion engines having at least two cylinders (DE 38 08 396 A1) comprise a fuel injection valve with two injection holes, the hole axes of the injection holes forming an acute angle with each other, Two fuel jets are obtained which are discharged in different directions during the weighing. The fuel injection is made into a suction tube which guides combustion air to the combustion cylinder, the suction tube being bent at the end side by a Y-tube. 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 is a pipe wall of the suction pipe disposed opposite the Y pipe such that the injection hole axes are approximately in line with the axis of the leg portion of the Y tube and thus fuel jets are injected in the direction of the leg into the air volume passing through the suction tube. Is inserted into

It is an object of the present invention to provide a fuel injection device in which manufacturing and mounting costs are reduced.

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

An advantage of the fuel injection device according to the invention with the features of claim 1 is that a plurality of flow channels extend into different cylinders using one multijet injection valve that injects at least two fuel jets in different diverging directions. By injecting fuel into them, some of the second group of fuel injection valves, which are generally used only as auxiliary parts, can be saved and thus the manufacturing and mounting costs for a dual injection system can be reduced. By reducing the number of fuel injection valves, weight savings and system simplification are achieved.

The measures set out in the other claims enable the preferred implementation and refinement of the fuel injection device set forth in claim 1.

According to a preferred embodiment of the invention, the fuel jets of each multijet-injection valve are guided in the injection channels separated in a sealing manner from one another to the flow channels by the multijet-injection valve. This prevents pneumatic coupling of the flow channels by the insertion of a multijet-injection valve, which ensures on the one hand an evenly even distribution of the fuel volume into the flow channels and on the other hand the uniformity of air and fuel into the cylinder. Air leakage between the flow channels, which can cause undistributed distribution, is prevented by vibration of the air columns in the flow channels

According to a preferred embodiment of the invention, the air flow path comprises at least one intake module, the intake module having two separate intake channels, each forming a flow channel. An accommodation chamber for the two jet-injection valve and two injection channels extending into the suction channels are formed in the suction module, the injection channels diverging from the receiving chamber. The suction module is preferably implemented by injection- or die casting, in which the chamber and the channel can simply be molded. After the two jet-injection valve is placed in the receiving chamber, it is ensured that each fuel jet is injected into a separate flow channel which is separated from the other flow channel in a sealed manner, so that the fuel amount for the two cylinders is uniformly distributed. Guaranteed. Compressed pneumatic coupling of the two flow channels through the injection channel and the receiving chamber may be excluded or minimized.

The invention is explained in detail with reference to the embodiment shown in the drawings.

1 is a schematic diagram of a fuel injection device for a four cylinder internal combustion engine;
2 is a longitudinal sectional view of a suction module comprising 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 of FIG.

As an example for a multi-cylinder-internal combustion engine of a vehicle, a four-cylinder-internal combustion engine comprises 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 together with the piston guided to the cylinder 11, which is not shown in each cylinder 11. The combustion chamber comprises 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 injector is provided with an air flow path 18 for supplying combustion air to the combustion chamber 13 of the cylinder 11, and a fuel injection valve 19 for directly injecting fuel into the combustion chamber 13 of the cylinder 11. And a second group of fuel injection valves 20 for injecting fuel into the flow channel 17, wherein the air flow path extends into individual inlet channels 16, the ends of which are separated from each other. Flow channels 17.

The first group of fuel injection valves 19 directly injecting into the cylinder 11 receives fuel from the fuel-high pressure pump 21, while the first group of fuel injection valves 20 injects into the flow channel 17. The second group receives fuel from the low pressure pump 22. In general, a fuel-low pressure pump disposed within fuel tank 23 directs fuel from fuel tank 23 to a second group of fuel injection valves 20 on the one hand and to fuel high pressure pump 21 on the other. Send it out. The injection timing and the injection duration of the fuel injection valves 19, 20 are controlled according to the operating point of the internal combustion engine by an electronic control unit integrated in the engine control, and substantially the fuel injection is carried out by the first group of fuel injections. Made by the valves 19 and in order to ameliorate the deficiencies of the fuel direct injection by the first group of fuel injection valves 19 in a particular operating range and to utilize additional degrees of freedom or injection strategy. Fuel injection valves 20 are used complementarily.

In order to lower the manufacturing cost of the fuel injection device, the second group of fuel injection valves 20 are formed as multi-jet injection valves, which are separated to simultaneously inject at least two fuel jets angularly offset from each other, Injected fuel jets 24, 25 having a generally conical shape are arranged in the air flow path 18 to reach various flow channels. In the case of the four-cylinder internal combustion engine used as an example, two two-jet injection valves 26 and 27 are arranged, and the injection valves have one two-jet injection valve 26 having a first and a second cylinder. The air flow path to inject into the flow channel 17 extending to (11) and the second two-jet injection valve 27 to inject into the flow channel 17 extending to the third and fourth cylinders 11 18). For this purpose the flow channels 17 are formed such that a mounting point for the two-jet injection valve 26 or 27 is provided between two directly adjacent flow channels 17. Two-jet injection valves are for example disclosed in DE 38 08 396 A1 or DE 44 20 063 A1.

In the structural embodiment of the fuel injector, the air flow path 18 comprises one intake module 28 for each cylinder pair, the intake modules having two separate, each forming flow channels 17. It has suction channels 29 and 30. The suction module 28 for the first and second cylinder 11 pairs is shown in perspective view in FIG. 3 and in longitudinal section in FIG. 2. To the suction module 28 an accommodating chamber 31 for a two jet-injection valve 26 and two inflow channels 32, starting from the accommodating chamber 31 and passing into suction channels 29 or 30, respectively; 33 is formed and one of the fuel jets 24, 25 injected at an angular offset by the two jet-injection valve 26 inserted into the receiving chamber 31 is guided in each inlet channel. As shown in the longitudinal sectional view of the suction module 28 according to FIG. 2 for the injection channel 32, each injection channel 32 or 33 is formed at the inlet 34 at the bottom of the receiving chamber 31 and respectively. Outlet 35 on the wall of the suction channel 29 or 30 of the apparatus. Inlet and outlet 34 and 35 are arranged so that each injected jet of fuel 24, 25 passes through the inlet and outlet 34, 35 without substantially contacting the channel wall and the injection channel 32 or 33) is formed. The suction module 28 is arranged in the cylinder head 12 of the internal combustion engine such that the two suction channels 29, 30 are congruent with each inlet channel 16 in the cylinder head 12. Fixing the suction module 28 to the cylinder head 12 is accomplished by a fixing flange 36 disposed at the downstream end of the suction module 28.

Equally formed suction modules 28 are also provided for the third and fourth cylinders 11 pairs. A second two jet-injection valve 27 is inserted into the receiving chamber 31 of the suction module 28.

On the upstream side, a suction module 28 for the first and second cylinders 11 and a suction module 28 for the third and fourth cylinders 11 are connected to a suction pipe manifold (not shown), and the suction pipe manifold is connected to the suction pipe manifold. Four suction channels 29, 30 are integrated. Upstream of the integration point an air mass regulator, such as a throttle valve, is usually arranged.

11 cylinder
17 flow channels
18 Air Flow Path
20 fuel injection valve
24, 25 fuel jet

Claims (5)

A fuel injection device for a multi-cylinder-internal combustion engine, comprising: an air flow path (18) for supplying combustion air, each cylinder having separate flow channels (17) at its end, extending into individual cylinders (11), each cylinder A fuel injection device comprising a first group of fuel injection valves 19 for directly injecting fuel into (11) and a second group of fuel injection valves 20 for injecting fuel into the flow channel 17. To
The second group of fuel injection valves 20 is formed as multi-jet-injection valves 26, 27 which simultaneously inject at least two separate fuel jets 24, 25, Fuel injection valves (20) are arranged in the air flow path (18) such that the injected fuel jets (24, 25) reach different flow channels (17). 2. A second group of fuel injection valves (20) in a four cylinder internal combustion engine comprises two two jet injection valves (26, 27), wherein the two jet injection valves are: Second jet injection valve 26 is injected into the flow channel 17 extending to the first and second cylinders 11, and another two jet injection valve 27 is directed to the third and fourth cylinders 11. A fuel injection device, characterized in that it is arranged to inject into an extending flow channel (17). 3. The fuel jets (24, 25) according to claim 1 or 2, wherein the fuel jets (24, 25) are in injection channels (32, 33) separated in a sealing manner from one another to the flow channel (17) by multi-jet injection valves. A fuel injection device, characterized in that guided. 4. The air flow path (18) of claim 3, wherein the air flow path (18) comprises at least one intake module (28) having two separate intake channels (29, 30) forming each flow path (17), In the suction module 28 there is formed an accommodating chamber 31 for a two jet-injection valve 26 and two injection channels 32, 33 extending into the suction channels 29, 30. Fuel injection device, characterized in that the injection channels start from the receiving chamber (31). 5. The inlet 34 at the bottom of the receiving chamber 31 and the outlet 35 at the wall of each inlet channel 29, 30, respectively. And inlet and outlet 34, 35 are arranged such that fuel jets 24, 25 pass preferably through the inlet and outlet 34, 35 without wetting the channel wall. 32, 33), characterized in that the fuel injection device.

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