DE10349778A1 - Fuel injecting valve for use in diesel internal combustion engine, has multi-hole nozzle with spraying hole channels that are located on one central longitudinal axis and are oppositely arranged in pairs - Google Patents

Abstract

The valve has a multi-hole nozzle (1) with four spraying hole channels (51-54) that are located on one of two central longitudinal axes and are oppositely arranged in pairs. Two points (S1, S2) of the central longitudinal axes are formed on a common circle line (K). A diameter (Dk) of the circle common line is smaller than a diameter of a valve seat surface of a nozzle body (2).

Description

The The invention relates to a fuel injection valve for internal combustion engines, especially for diesel internal combustion engines with an injector, the as a multi-hole nozzle is configured, consisting of a nozzle body with an internal bore, in the one nozzle needle is arranged axially displaceable, wherein the fuel from the inner bore starting over several spray-hole channels is injected into the combustion chamber and wherein the injection hole channels in the Wall of the nozzle body in such a way are arranged that a fictitious extension of their respective central longitudinal axis outside the contour of the central longitudinal axis the nozzle needle runs.

Injectors for diesel internal combustion engines consist essentially of two modules, the nozzle body and the nozzle needle. The nozzle body is predominant Cylindrically formed with an inner bore, in which the nozzle needle is arranged axially displaceable. The nozzle body has on the combustion chamber side End usually a tapered hilltop area on, of a blind hole is completed. At the bottom of the nozzle needle is designed a sealing cone, with a conical sealing surface in the bottom Area of the nozzle body in Active compound is. From the blind hole or the conical crest area starting from the nozzle body leads at least a spray hole channel through the wall of the nozzle body in the combustion chamber.

For today usual air distributing Burning processes become multi-hole nozzles used in dependence the desired swirl intensity predominantly four to eight spray-hole channels exhibit. The fuel is in the inner bore of the nozzle body with high pressure introduced. Once the first seated nozzle needle With its sealing cone lifts off the sealing seat in the nozzle body, the spray hole channels are free given and the fuel is injected into the combustion chamber. The Injection port channels run mostly as a straight through hole, the radial and oblique to the inner bore arranged the nozzle body is. Consequently, all spray-hole channels form one common injection hole cone, which ultimately the course of the injection jets defined in the combustion chamber.

The Formation of the injection jets essentially determines the parameters of the combustion process. Despite numerous already available constructions Therefore, there is still a further embodiment of the injection hole channels in the transition region from injector and combustion chamber sought to the performance of the respective internal combustion engine continue to optimize.

EP 0 352 926 A1 describes a multi-hole nozzle, wherein the inner inlet openings of the injection hole channels are larger than the outer outlet openings. This embodiment is achieved by means of electrical discharge machining. A similar solution is the subject of JP 2002-250259, wherein at the inner inlet opening of the spray-hole channels a depression is provided, which is produced with an abrasive liquid. At the fuel injection valve after DE 195 07 171 C1 be rounded at a multi-hole nozzle, the inner inlet regions of the injection hole channels. This technical solution is in DE 199 31 890 A1 has been further developed by the inlet region of the injection hole channel is designed in the form of an ellipse.

With Such geometrical configurations in the inlet region of the injection hole channels become sharp Edges in the flow path avoided and thus a vortex formation and throttling of the fuel reduced. The deflection of the fuel at the transition from the cylindrical inner bore However, in the radially branching injection hole channels causes Umström- and speed losses, which adversely affect the injection behavior in the combustion chamber.

These disadvantages are intended according to US Pat. No. 6,029,913 be overcome by the injection hole channels have a circular arc-shaped contour. In this case, the spray-hole channels are arranged such that a fictitious extension of their central longitudinal axes approximately intersects the (also fictitiously extended) central longitudinal axis of the nozzle needle.

Further From JP 11-324 868 a multi-hole nozzle is known in which the injection hole channels of the inner bore starting from the nozzle body tangentially in the direction of the combustion chamber. As a result, a "turning out" from the usual achieved radial alignment, wherein the injection hole channels arranged so are that a fictional extension of their respective central longitudinal axis outside the contour of the central longitudinal axis the nozzle needle runs. Thus, the flow and injection behavior of the fuel can be fundamentally improved. Indeed this embodiment requires a considerable production effort, which impairs an application in series production.

task The invention is a multi-hole nozzle for fuel injection valves to create, in which the spray hole channels at least slightly different are arranged by the radius. In this case, in particular an arrangement be created, with both an improved injection behavior across from conventional radial arrangement as well as a reduced manufacturing cost across from previously known non-radial arrangement is achieved.

This task is solved by little ones at least two points of intersection of the central longitudinal axes of adjacent injection hole channels are arranged on a common circular line, the diameter of which is smaller than the diameter of a hole circle formed by the central longitudinal axes of the injection hole channels on the valve seat surface of the nozzle body. Alternatively, it is proposed that the injection hole channels are arranged such that a fictitious extension of all their central longitudinal axes results in a common point of intersection outside the contour of the central longitudinal axis of the nozzle needle. In this case, it is provided in a further embodiment that in each case two spray-hole channels are arranged in pairs opposite each other on a common central longitudinal axis.

Consequently becomes a multi-hole nozzle for the Fuel injection created with the exit from the Injection port channels a long and contour-stable injection jet is generated, the a deep penetration of fuel into the combustion chamber of the assigned Internal combustion engine allows. Now you can also combustion chamber sections, the constructive due to a relative huge Distance to the outlet opening the spray hole channels have enough fuel. consequently is with the construction according to the invention the combustion process of internal combustion engines improved. simultaneously is the production cost for the spray hole channels across from previously known non-radial arrangements advantageously reduced.

One embodiment The invention is illustrated in the drawing and will be described below described. Show it:

1 the basic structure of a multi-hole nozzle according to the invention with, for example, four spray hole channels in a sectional view

2 the basic structure of an alternatively designed multi-hole nozzle with, for example, eight spray hole channels in side and sectional view

3 a further embodiment with, for example, four spray hole channels

4 as a detail, the arrangement and design of a spray hole channel

In the drawing, a fuel injection valve is shown, which is particularly suitable for diesel internal combustion engines, whose injection nozzles as Mehrlochdüse 1 are designed. The multi-hole nozzle 1 consists essentially of a nozzle body 2 with an internal bore 3 , In the inner bore 3 is a nozzle needle 4 arranged axially displaceable. The central longitudinal axis of the nozzle needle 4 is denoted by the reference "X". In the wall of the nozzle body 2 are several spray hole channels 5 designed. A fictitious extension of the respective central longitudinal axes "Y _{1... N} " of the injection-hole channels 5 runs outside the contour of the central longitudinal axis "X" of the nozzle needle 4 , The extended center longitudinal axes "Y _{1 ... n} " consequently have no point of intersection with the likewise extended center longitudinal axis "X". About the spray hole channels 5 becomes the fuel, starting from the inner bore 3 injected into the (not shown in the drawing) combustion chamber.

Out 1 is the essential in the present case arrangement of the spray hole channels 5 seen. In the wall of the nozzle body 2 For example, there are four spray-hole channels 5 ₁ to 5 ₄ designed, whose center longitudinal axes with "Y ₁ " to "Y ₄ " are designated. The injection hole channels 5 ₁ to 5 ₄ form a circle of holes in a conventional manner. The central longitudinal axes "Y ₁ " and "Y ₂ " of the adjacent spray hole channels 5 ₁ and 5 ₂ meet at an intersection "S ₁ ". Furthermore, the central longitudinal axes "Y ₂ " and "Y ₃ " of the likewise adjacent injection hole channels meet 5 ₂ and 5 ₃ in an intersection "S ₂ ". The two points of intersection "S ₁ " and "S ₂ " are arranged on a common circular line "K", which has a diameter "D _K ". This diameter "D _K " is always smaller than the diameter of the bolt circle on the valve seat surface of the nozzle body 2 , The fourth injection hole channel 5 ₄ can also be arranged so that its central longitudinal axis "Y ₄ " on the circle line "K" results in an intersection with the central longitudinal axis of an adjacent injection hole channel.

Likewise, the injection hole channel 5 ₄ (as in 1 represented) in another contour, in which no common point of intersection on the circle "K" arises.

In an alternative arrangement according to 2 are the spray hole channels 5 arranged such that the notionally extended central longitudinal axes "Y _{1 ... n} " of all spray-hole channels 5 give a common intersection "S". This intersection "S" is outside the contour of the central longitudinal axis "X" of the nozzle needle 4 ,

3 shows an embodiment with, for example, four spray-hole channels 5 of which two pairs are arranged opposite each other on a common central longitudinal axis "Y ₁ " or "Y ₂ ".

In addition to the arrangements shown, numerous further arrangements are possible within the scope of the invention in which the extended central longitudinal axes "Y _{1... N} " of the injection-hole passages 5 no intersection with the extended center longitudinal axis "X" of nozzle needle 4 have, but run outside of the contour. This basic embodiment is made 4 again in detail, with only a single and enlarged illustrated injection hole channel 5 is shown, whose center longitudinal axis is denoted by "Y ₅ ". With broken lines is the radial arrangement of another injection hole channel 6 shown according to previously customary constructions. In such an embodiment, the extended central longitudinal axis "Y ₆ " cuts the likewise extended central longitudinal axis "X" of the nozzle needle 4 , As further out 4 it can be seen, it is expedient, the inner inlet region of the injection hole channels 5 To round off arcuate, so that at this point an uncontrolled vortex formation and throttling of the fuel due to sharp edges is avoided.

1

multi-hole nozzle

2

nozzle body

3

internal bore

4

nozzle needle

5

Injection port channel

6

Injection port channel

K

circle line

D _K

diameter circle line

S

intersection the central longitudinal axes the spray hole channels

X

central longitudinal axis nozzle needle

Y

central longitudinal axis Injection port channel

Claims (3)

Fuel injection valve for internal combustion engines, in particular for diesel internal combustion engines with an injection nozzle, which is designed as Mehrlochdüse consisting of a nozzle body with an inner bore in which a nozzle needle is arranged axially displaceable, wherein the fuel injected from the inner bore via a plurality of injection port channels into the combustion chamber is and wherein the injection hole channels are arranged in the wall of the nozzle body such that a fictitious extension of their respective central longitudinal axis runs outside the contour of the central longitudinal axis of the nozzle needle, characterized in that at least two intersections (S ₁ ; S ₂ ) of the central longitudinal axes (Y _{1. ..n} ) of adjacent spray hole _channels ( 5 ) are arranged on a common circular line (K) whose diameter (D _K ) is smaller than the diameter of a through the central longitudinal axes (Y _{1 ... n} ) of the injection hole channels ( 5 ) formed on the valve seat surface of the nozzle body ( 2 ). Fuel injection valve for internal combustion engines, in particular for diesel internal combustion engines with an injection nozzle, which is designed as Mehrlochdüse consisting of a nozzle body with an inner bore in which a nozzle needle is arranged axially displaceable, wherein the fuel injected from the inner bore via a plurality of injection port channels into the combustion chamber and wherein the spray-hole channels are arranged in the wall of the nozzle body such that a fictitious extension of their respective central longitudinal axis runs outside the contour of the central longitudinal axis of the nozzle needle, characterized in that the injection-hole channels ( 5 ) are arranged such that a fictitious extension of all their central longitudinal axes (Y _{1 ... n} ) a common intersection (S) outside the contour of the central longitudinal axis (X) of the nozzle needle ( 4 ). Fuel injection valve according to claim 2, characterized in that in each case two spray-hole channels ( 5 ) are arranged in pairs opposite one another on a common central longitudinal axis (Y ₁ , Y ₂ ).