KR20130102489A - Fuel injector - Google Patents

Abstract

PURPOSE: A fuel spray is provided to have simple configuration and to facilitate maintenance and repair. CONSTITUTION: A fuel spray comprises a spray nozzle (10), a conversion valve (20), and a connection sleeve (30). The spray nozzle sprays fuel and has a protruding portion (12). A conversion valve controls the spray of the fuel and has a protruding portion (22). The connection sleeve is arranged between the spray nozzle and the conversion valve and has a penetrating portion (33).

Description

[0001] FUEL INJECTOR [0002]

The present invention relates to various fuel injectors for an internal combustion engine.

In practice, a known internal combustion engine, for example, a marine diesel engine, includes a plurality of cylinders, and at least one fuel injector is assigned to each of the cylinders, thereby supplying fuel to each cylinder. These fuel injectors are usually made up of a plurality of parts mounted continuously in the longitudinal direction, and the parts must be fixed to one another in a specific alignment (e.g. with respect to its longitudinal axis and its rotational position).

In practice, in this known fuel injector, the alignment of the plurality of parts is made by a so-called fitting pin which is inserted into the fitting pin hole of the part. DE 2 309 134 A discloses, for example, such a number of fuel injectors, in which the nozzle arrangement is aligned with respect to the nozzle holder by a fitting pin.

However, the fitting pin has a disadvantage that it is easily broken due to mechanical overload in mounting or disassembling the fuel injector, and this destruction generally requires complicated maintenance work of several parts in connection with the recovery of the broken fitting pin in particular .

Another disadvantage of the fitting pin is that the fitting pin, which receives the fitting pin, is normally inserted into the sealing surface between the parts, so that the fitting pin protrudes from the sealing surface after its mounting, For example, lapping), the fitting pin must be complicatedly removed.

SUMMARY OF THE INVENTION It is an object of the present invention to provide various parts of a fuel injector in which the parts are aligned with each other in a simple and easy to maintain manner.

The above object is achieved by the fuel injector according to claim 1. Advantages of the invention are set forth in the dependent claims.

According to the present invention, there is provided a fuel injector comprising a plurality of parts connected to each other, a spray nozzle for injecting fuel, a switch valve for controlling injection of fuel, and a connection sleeve disposed between the injection nozzle and the switch valve, Wherein the injection nozzle includes a predetermined outer nozzle contour in its longitudinal end section and the diverter valve includes a predetermined valve outer contour in its longitudinal end section and the connecting sleeve comprises a predetermined sleeve inner contour, The nozzle outer contour of the jetting nozzle from the first longitudinal end is press fit into the sleeve interior contour such that the jetting nozzle is fixed in a defined alignment for the connecting sleeve and is switched from the second longitudinal end of the connecting sleeve The valve outer contour of the valve is shaped into the inner contour of the sleeve By being press-fitted by the following formula, the selector valve is held in a defined alignment of the coupling sleeve.

In other words, by fitting the valve outline to the inner outline of the sleeve in a shape fit manner, the first shape fit shaft-hub engagement portion is formed as alignment means and the outer contour of the nozzle is fitted to the outline of the sleeve in a shape- By fitting, the second shape fitting shaft-hub engagement portion is formed as alignment means. Thus, the valve outer contour and the nozzle outer contour, respectively, are complementarily formed with respect to the inner contour of the sleeve.

The axial binding of the individual components of the fuel injector is made, for example, by one or a plurality of union nuts which are fixed to the external threads of the corresponding ring collar, for example, as in the prior art.

By the shape fitting according to the invention of the nozzle outer contour and the valve outer contour and the sleeve inner contour, the parts of the fuel injector are aligned with each other in a particularly simple and easy-to-maintain manner.

If the parts of the fuel injector have to be disassembled and, if necessary, post-machined, the shaft-hub engagement can be released by simply removing the individual components from the connecting sleeve after unfastening the axial coupling. It is not necessary to remove the fitting pin for the post-processing of the sealing surface.

Since the fuel injector according to the present invention having a shaft-hub connection portion implemented by a polygonal profile is much less sensitive to mechanical loads, there is less risk of damage to the alignment means during mounting and disassembly.

Also, by means of the above-described part embodiments, the transmission of a much larger fixed torque is possible, for example, by one or a plurality of union nuts, which is increasingly necessary to obtain sufficient tightness in consideration of the ever increasing injection pressure.

The connecting sleeve is preferably dimensioned or configured to form the weakest part of the parts. As a result, only the connecting sleeve is destroyed or damaged in the event of mechanical overload, so that it can be replaced simply and without a variety of tools.

According to an embodiment of the present invention, the sleeve inner contour may have an inner diameter different from its longitudinal end section that is fitted with the valve outer contour in its longitudinal end section fitted with the nozzle outer contour. This embodiment of the invention has the advantage that the parts, i.e. the injection nozzle and the switching valve, can be press-fit into a common connection sleeve, even though dimensionally designed in consideration of space availability.

In accordance with another embodiment of the present invention, the nozzle outline and valve outline are pushed in a shape-fit manner into the sleeve interior contour, so that the injection nozzle and the diverter valve each have a centering connection sleeve Aligned to the specified condition for the connecting sleeve.

In other words, the longitudinal axes of the injection nozzles and the diverter valve are aligned with their longitudinal axes by the shaft-hub engagement and relative to each other and accordingly to their respective rotational positions about the longitudinal axis, Or centered.

According to an embodiment of the present invention, the inner contour of the sleeve has a polygonal shape. Such a polygonal shape formed or present in a complementary manner at the nozzle outer contour and the valve contour can be produced, for example, by non-circular turning or non-circular grinding or milling.

Preferably, the polygonal shape is formed at least triangular (e.g., P3G according to DIN 32711 in a constant width shape), in particular hexagonal or hexagonal.

In accordance with an embodiment of the present invention, the inner contour of the sleeve is formed symmetrically with respect to the longitudinal axis of the connecting sleeve.

In this case, preferably a first projection-recess fit is provided between the inner sleeve contour and the nozzle outer contour, and the first projection-recess fitting defines a single possible rotational alignment of the spray nozzle with respect to the connecting sleeve And a second projection-recess fitting is provided between the sleeve inner contour and the valve outer contour, said second projection-recess fitting defining a single possible rotational alignment of the switching valve for the connecting sleeve.

This results in a clear rotational position setting between the injection nozzle, the switching valve and the connecting sleeve.

In accordance with an alternative embodiment of the present invention, the inner sleeve contour is formed asymmetrically with respect to the longitudinal axis of the connecting sleeve.

In this case, the polygonal shape with multiple sides preferably has at least one side with a different length than the other side of the polygonal shape. More preferably, the polygonal shape has a first side having a shorter length than the other side of the polygonal shape, and a second side having a longer length than the other side of the polygonal shape.

As a result, a clear rotational position is also established between the injection nozzle, the switching valve and the connecting sleeve.

According to an embodiment of the present invention, a fuel throttle is press-fit between the injection nozzle and the switching valve in a shape-fitting manner into the inside contour of the sleeve. In other words, the throttle outer contour is shaped to fit the inner contour of the sleeve or is complementarily formed with respect to the inner contour of the sleeve, thereby forming the third shape fitting shaft-hub coupling.

Between the throttle outer contour and the inner contour of the sleeve, a protrusion-recess fit may be provided in the case of a symmetrical configuration of the inner contour of the sleeve with respect to the longitudinal axis. In the case of an asymmetrical configuration of the inner contour of the sleeve with respect to the longitudinal axis, the throttle outer contour may only be complementary to the inner contour of the sleeve.

Therefore, also in relation to the fuel throttle, a clear rotational position setting is made for the other parts of the fuel injector.

Preferably all shaft-hub joints or shape fittings are implemented as a slightly loose fit or as an intermediate fit.

In accordance with the present invention, there is provided an internal combustion engine, particularly a marine diesel engine, having a fuel injector according to one of the above-described embodiments of the present invention, a plurality of the foregoing embodiments, or all the above-described embodiments in all possible combinations.

As a result, according to an embodiment of the present invention, the centering and clear positioning (i.e., the prescribed alignment) of the injection nozzles and optionally the fuel throttle in the selector valve of the fuel injector is provided by the selector valve, Profile.

The fitting sleeve is not required by the connecting sleeve or the centering sleeve as the connection part between the fuel nozzle and the fuel throttle of the fuel injector with the selector valve and, in some cases, the selector valve. As a result, the number of additional components required for alignment is reduced from four to one.

Failure of the fitting pin during mechanical overload during disassembly or mounting requires complex maintenance of the diverter valve or injection nozzle upon recovery of the failed fitting pin. In the case of mechanical overload of the connecting sleeve, however, it can be replaced without additional tools.

By the implementation of a polygonal profile as an asymmetric structure or as an axisymmetric structure with a protrusion-recess fitting (e.g., positioning the fitting pin and associated fitting pin recess transverse to the longitudinal direction of the connecting sleeve) , Clear positioning or alignment of the fuel throttle and the switching valve is possible.

Prior art fitting pins are often overloaded. In the same size injection nozzle, a larger torque can be delivered through the polygonal connection than through the fitting pin used in the prior art until now.

Alignment (preferably including centering) of the injection nozzles to the fuel throttle and the diverter valve is effected by a polygon-shaped shaft-hub engagement, such as a shaft-hub engagement-polygon profile P3G (DIN 32711). At least at two edges of at least two edges of the triangular profile or by forming axially symmetrical profiles with centering pins or by forming at least one shortened side LY and at least one extended side L + By virtue of the formation of an asymmetric profile, for example a hexagon with X = Y, can be excluded, for example by virtue of a 120 degree rotation about the longitudinal axis of the components of the fuel injector. Therefore, the fitting pin of the original shape can be omitted.

The present invention extends to embodiments not given by combinations of features shown in the citation of the claims, so that the disclosed features of the present invention may be arbitrarily combined with each other if technically desirable.

The present invention provides various parts of the fuel injector in which the parts are aligned with each other in a simple and easy to maintain manner.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.
1 is an exploded perspective view of a fuel injector according to an embodiment of the present invention;
2 is a perspective view of a connection sleeve of a fuel injector according to another embodiment of the present invention;
Fig. 3 is a cross-sectional view or front view of the connection sleeve of Fig. 2;
FIG. 4 is a longitudinal section of the connecting sleeve of FIG. 2 as viewed along line AA of FIG. 3;

1 is an exploded perspective view of a fuel injector 1 formed in accordance with a first embodiment of the present invention of an internal combustion engine (not fully shown) formed here with a marine diesel engine.

The fuel injector 1 is provided with an injection nozzle for injecting fuel (diesel fuel in this case), a selector valve for controlling (allowing / blocking) the injection of fuel, and a selector valve And includes a centering sleeve 30 or coupling sleeve disposed therein.

The injection nozzle 10 has a predetermined nozzle outer contour 12 in its longitudinal end section 11 toward the connecting sleeve 30 and the switching valve 20 has its longitudinal end 22 towards the connecting sleeve 30, Has a predetermined valve outer contour (22) in the section (21).

The connecting sleeve 30 has a predetermined sleeve interior contour 33 and the nozzle outer contour 12 of the jet nozzle 10 from the first longitudinal end 31 of the connecting sleeve 30 is aligned with the inner sleeve contour 33 , The injection nozzle 10 is fixed in the prescribed alignment with respect to the connecting sleeve 30. As a result,

The valve outer contour 22 of the switch valve 20 is also press-fitted into the sleeve inner contour 33 from the second longitudinal end 32 of the connecting sleeve 30 in a shape- Are fixed in the prescribed alignment with respect to the connecting sleeve 30. [

In other words, the valve outer contour 22 is shaped to fit the inner sleeve contour 33 so that the first shape fitting shaft-hub coupling is formed as an alignment means, Fit into the sleeve inner contour 33 so that the second shape fitting shaft-hub engagement portion is formed as alignment means. Thus, the valve outer contour 12 and the nozzle outer contour 22 are each formed complementary to the inner sleeve contour 33.

Fuel throttle 40 is further pressed between the injection nozzle 10 and the switching valve 20 in a shape-fitting manner by being fixed in the prescribed alignment with respect to the connecting sleeve 30 into the sleeve inner contour 33.

In other words, the throttle outer contour 41 of the fuel throttle 40 is shaped to fit the inner contour 33 of the sleeve or is complementary to the inner contour 33 of the sleeve, A customized shaft-hub engagement portion is formed as an alignment means.

Preferably, all shaft-to-hub joints or feature fittings are implemented as slightly loose fit or intermediate fit.

1, the injection nozzle 10 has a longitudinal axis L1, the switching valve 20 has a longitudinal axis L2, the connecting sleeve 30 has a longitudinal axis L3, and the fuel throttle 40 has a vertical axis L1, (L4).

In accordance with the present invention, the nozzle outer contour 12, valve outer contour 22 and throttle outer contour 41 are pressed into the sleeve inner contour 33 in a shape-fitting manner, And the fuel throttle 40 are associated with their respective longitudinal axes L1, L2 or L4 and their respective rotational positions about their respective longitudinal axes L1, L2 or L4 Aligned to the connection sleeve 30. In other words, the longitudinal axes L1, L2 or L4 of the injection nozzle 10, the switching valve 20 and the fuel throttle 40 are connected by the shaft- Are aligned or centered with respect to one another (L3) and therefore to each other and also to their respective rotational positions about the longitudinal axes (L1, L2 or L4) and accordingly to each other.

In order to effect the alignment, the valve outer contour 12, the nozzle outer contour 22 and the throttle outer contour 41 each have a polygonal shape and the sleeve inner contour 33 is defined by the outer contour (the valve outer contour 12) The nozzle outer contour 22 and the throttle outer contour 41). The inner and outer polygonal shapes can be produced, for example, by non-circular turning or non-circular grinding or milling.

According to the invention, the respective polygonal shapes of the components of the fuel injector 1 are formed at least triangularly, in particular according to Fig. 1, of a hexagonal shape.

Axial (longitudinal) engagement of the individual components of the fuel injector 1 is typically done by one or a plurality of union nuts (not shown), as in the prior art, The ring collar 13 of the injection nozzle 10) and the external threads of the components (not shown).

Although not shown in FIG. 1, according to an embodiment of the present invention, a sleeve inner contour 33 is fitted with a valve outer contour 22 in its longitudinal end section 31.1, which is fitted with a nozzle outer contour 12, And may have an inner diameter different from that of the longitudinal end section 32.1. This embodiment of the invention has the advantage, in particular, that the parts, namely the injection nozzle 10 and the switching valve 20, can be press-fitted into a common connecting sleeve 30, even though they are dimensionally designed in consideration of space availability.

1, the respective polygonal shapes (valve outer contour 12, nozzle outer contour 22, sleeve inner contour 33 and nozzle outer contour 41) of the components of the fuel injector 1 are The turning position setting between the injection nozzle 10, the switching valve 20, the fuel throttle 40 and the connecting sleeve 30 is set to be asymmetrical with respect to the longitudinal axes L1, L2, L3 or L4 . In other words, the components of the fuel injector 1 can each be inserted into the connecting sleeve 30 in a single predefined rotational position setting.

In particular, each polygonal shape has at least one side (S, S ', S "), edges (E) connecting it, and at least one side S ', S ") (three sides in FIG. 1).

1, each polygonal shape includes three sides S ', S "having a shorter length than the other sides S of the polygonal shape. The sides S', S & S "of one of the side surfaces S ', S" formed in a shorter length of the polygonal shape has a length shorter than the other side S' of the side surfaces S ', S ".

Figures 2 to 4 show a connecting sleeve 30a formed in accordance with a second embodiment of the present invention of a fuel injector 1a (not shown fully) of an internal combustion engine (not shown fully) formed as a marine diesel engine .

The fuel injector 1a according to the second embodiment of the present invention is formed in the same manner as the fuel injector 1 according to the first embodiment of the present invention except for a few differences. Therefore, only the above difference will be described below, and the same or similar parts as in FIG. 1 are denoted by the same or similar reference numerals, and the lower part "a" As shown in Figs. 2 to 4, each polygonal shape of the components of the fuel injector 1a is formed at least triangular, in particular hexagonal in this case.

Each of the polygonal shapes (valve outer contour, nozzle outer contour, inner sleeve contour 33a and nozzle outer contour) of the components of the fuel injector 1a are formed asymmetrically with respect to their longitudinal axes, , The fuel throttle and the connecting sleeve 30a. Thus, the components of the fuel injector 1a can each be inserted into the connecting sleeve 30a only with a single predefined rotational position setting. Specifically, each polygonal shape of the components of the fuel injector 1a is defined by a plurality of sides S, S ', S ", the edges E connecting them, and the other side S of the polygonal shape (S ', S ") (two sides in Figs. 2-4) with different lengths.

2 to 4, each polygonal shape of the components of the fuel injector 1a has a first side S " having a length LY shorter than the other side S of the polygonal shape, and a second side S " And a second side S 'having a length L + X that is longer than the length L (with length L).

According to a variant not shown in the drawings of the first and second embodiments of the present invention, each polygonal shape (valve outer contour, nozzle contour, sleeve inner contour and throttle outer contour) is symmetrical with respect to its vertical axes .

In this case, a first projection-recess fit is provided between the inner sleeve contour and the nozzle outer contour, and the fit defines a single possible rotational alignment of the spray nozzle with respect to the connecting sleeve.

In addition, a second projection-recess fit is provided between the inner sleeve contour and the valve outer contour, and the fit defines a single possible rotational alignment of the diverter valve for the connecting sleeve. Finally, a protrusion-recess fit is provided between the throttle outer contour and the inner sleeve contour, which defines a single possible rotational alignment of the fuel throttle with respect to the connecting sleeve.

Each protrusion-recess fitting may include, for example, a fitting pin recess extending transversely to the longitudinal axis (of the injection nozzle, the switching valve or the fuel throttle) at each outer contour and a radial direction from the inner contour of the sleeve transversely to the longitudinal axis And a fitting pin protruding into the fitting pin recess to be inserted into the fitting pin recess. Preferably, the fitting pin recess has an open end in the longitudinal direction of each of the parts, and when the parts are inserted into the connecting sleeve, the fitting pin can be inserted through the end into each fitting pin recess.

1 fuel injector
1a fuel injector
10 injection nozzle
11 longitudinal end section
12 Nozzle Outline
13 ring collar
20 switching valve
21 longitudinal end section
22 Valve Outline
30 connecting sleeve
30a connecting sleeve
31 longitudinal end
31.1 Lengthwise end section
31.1a longitudinal end section
32 longitudinal end
32.1 Lengthwise end section
32.1a longitudinal end section
33 Sleeve interior contour
33a Sleeve inner contour
40 Fuel throttle
41 Throttle Outline
L1, L2
L3, L4
L Length
X, Y Length
S, S ', S "side
E edge

Claims (10)

A switching valve 20 for controlling the injection of fuel and a connecting sleeve 30 and 30a disposed between the injection nozzle 10 and the switching valve 20 1. A fuel injector (1; 1a) comprising:
The injection nozzle 10 includes a predetermined nozzle outer contour 12 in its longitudinal end section 11 and the switch valve 20 has a predetermined valve outer contour 22 in its longitudinal end section 21 ),
The connecting sleeve 30,30a has a predetermined sleeve interior contour 33,33a and extends from the first longitudinal end 31 of the connecting sleeve 30,30a to the nozzle outer contour 33 of the spray nozzle 10. [ The injection nozzles 10 are fixed in a defined alignment with respect to the connection sleeves 30 and 30a and the connection sleeves 30 and 30a are fitted into the inside of the sleeve in a shape- The valve outer contour 22 of the switch valve 20 from the second longitudinal end 32 is press fit into the inner contour of the sleeve so that the switch valve 20 is in communication with the connection sleeve 30, And the fuel injector is fixed in a prescribed alignment with respect to the fuel injector. The method of claim 1, wherein the nozzle outer contour (12) and the valve outer contour (22) are press-fit into the sleeve inner contour (33; 33a) (20) are arranged in a defined condition relative to said connecting sleeve (30, 30a) with respect to their longitudinal axis (L1, L2) and their rotational position, respectively. 3. A fuel injector according to claim 1 or 2, characterized in that said sleeve inner contour (33; 33a) has a polygonal shape. 4. The fuel injector according to claim 3, wherein the polygonal shape is at least a triangular shape, particularly a hexagonal shape or a hexagonal shape. 5. A fuel injector according to claim 3 or 4, characterized in that the inside contour (33, 33a) is formed symmetrically with respect to the longitudinal axis (L3) of the connecting sleeve (30, 30a). 7. A method according to claim 5, characterized in that a first projection-recess fitting is provided between said sleeve inner contour (33; 33a) and said nozzle outer contour (12), said first projection- Defines a single possible rotational alignment of the injection nozzle (10) with respect to the valve inner contour (30; 30a), and a second protrusion-recess fit between the sleeve inner contour (33; 33a) Wherein said second projection-recess fitting defines a single possible rotational alignment of said selector valve (20) with respect to said connecting sleeve (30; 30a). 5. A fuel injector according to claim 3 or 4, wherein said sleeve inner contour (33; 33a) is formed asymmetrically with respect to the longitudinal axis (L3) of said connecting sleeve (30; 30a). 8. The method of claim 7, wherein the polygonal shape comprises at least one side (S ', S ") having a plurality of sides (S, S', S") and a length different from the other side (S) And a fuel injector. 9. The method of claim 8, wherein the polygonal shape comprises a first side (S ") having a shorter length than the other side (S) of the polygonal shape, and a second side (S '). ≪ / RTI > 10. A method according to any one of the preceding claims, characterized in that a fuel throttle (40) between the injection nozzle (10) and the switching valve (20) is fitted into the sleeve inner contour (33; 33a) And the fuel injector is press-fitted.

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