EP2186605A2 - Extendable coupling for injection nozzles - Google Patents

Abstract

The coupling (1) has a carrier (2) for an injection nozzle provided in a cylinder head, where the carrier is coupleable with a traction device and with an external thread (4) of a head part of the injection nozzle. The carrier exhibits one internal thread screwable on another internal thread (8) in a fitting manner. The carrier is provided with multiple radial-elastic deformable gripper elements (5) in an axial extension to the internal threads, where the gripper elements are braceable against the head part of the injection nozzle.

Description

The invention relates to a pull-out with a body for a seated in a cylinder head injector, which is coupled on the one hand with a pulling device and on the other hand with an external thread of a head portion of the injector.

Devices for extracting injectors are commonly known in the art. For this purpose is an example of the two documents DE 20 2004 009 755 U1 and the DE 20 2004 006 602 U1 directed.

In the device of DE 20 2004 009 755 U1 for drawing an injector, also referred to as a nozzle, a pulling device is provided with a support cylinder. Between the support cylinder and a valve cover placed on the cylinder head, a separate, divided support ring is provided, the annular portions of which are individually placed on the valve cover in the surrounding region of the nozzle. As an extractor is in the subject of DE 20 2004 009 755 U1 a Zugspindel described which, on the one hand in cooperation with a pull nut and the support cylinder, an extraction of the injection nozzle causes. On the other hand, such a traction spindle can also be part of a hydraulic cylinder through which correspondingly greater extraction forces can be applied. As an extraction coupling for coupling this threaded spindle with the injection nozzle, the threaded spindle toward the injection nozzle towards a mounting thread, which can be screwed after removal of the electrical connection part of the injection nozzle in a corresponding internal thread of the injection nozzle or a head portion of the injection nozzle. Due to the fact that such internal threads are usually designed to be extremely robust and stable, such an internal thread and large tensile forces can be applied to the injection nozzle, so that it can be pulled out of the cylinder head even with extremely tight fit.

Furthermore, from the DE 20 2004 006 602 U1 a device for extracting an injection nozzle, which has a hydraulically actuated tensioning spindle. This Zugspindel points at the subject of DE 20 2004 006 602 U1 a coupling thread as Ausziehkupplung, which is fixedly screwed into an internal thread of the head part of the injection nozzle accordingly. In addition to this external thread a kind of union nut is still provided, which is provided with an internal thread. This union nut is held axially on a radially projecting projection of the threaded spindle. According to the configuration of the internal thread of this union nut, this can be screwed onto an external thread of the head part of the injection nozzle, so that an additional hold can be achieved. This is especially at extremely high extraction forces of advantage, since a tearing the internal thread and / or the external thread of the head part of the injection nozzle is reliably avoided.

A disadvantage of the two aforementioned constructions that the internal thread of the injection nozzle must be made accessible by removing the nozzle insert of the injection nozzle.

Therefore, would be advantageous only the nut of the DE 20 2004 006 602 U1 to use or at least one similarly shaped coupling element which is screwed according to only the external thread of the head part of the injection nozzle.

However, injectors are also known from the prior art, in which the external thread is formed as a so-called. Fine thread and accordingly has only a very small thread depth of a few tenths of a millimeter. This in turn means that this fine thread can tear at extremely high tensile forces.

Accordingly, the invention has the object to design a pull-out such that it is on the one hand fixedly coupled to the external thread of the head portion of the injector and on the other hand, extremely high tensile forces can be applied to the injector.

The object is achieved according to the invention together with the features of the preamble of claim 1, characterized in that the base body has a fitting screwed onto the external thread internal thread, and that the main body in axial extension to its internal thread is provided with a plurality of radially elastically deformable gripper elements, which are clamped against the head part.

The inventive design a Ausziehkupplung is provided, with which extremely high extraction forces can be applied. For this purpose, on the one hand, the main body of the extraction coupling is provided with an internal thread, which is fittingly screwed onto the external thread of the head part of the injection nozzle. In addition to this internal thread, the main body in the axial extension of this internal thread on a plurality of radially elastically deformable gripper elements, which are braced against the headboard. Thus, by means of this radial clamping of these gripper elements against the head part, an additional hold due to the friction moments or due to possibly provided interlocking elements can be achieved. This increases at the same time precise attachment of the pull-out on the injection nozzle, the attachable pull-out force. As traction devices here various known from the prior art traction devices into consideration. Thus, on the one hand, draw spindles can be used in a conventional manner and, on the other hand, correspondingly hydraulic cylinders which can be coupled to the pull-out coupling.

Further advantageous embodiments of the invention can be taken from the further subclaims.

Thus, it can be provided according to claim 2 that the internal thread in the axial region of the radially elastically deformable gripper elements, in particular is arranged approximately centrally. This means that in such an embodiment the main body of the extraction coupling with its gripper elements can be screwed onto the external thread of the head part of the injection nozzle. By subsequent radial clamping of these gripper elements, the thread play - which is always present - minimized between the internal thread of the body and the external thread of the head part of the injection nozzle, so that the tendency of tearing of the external thread or the internal thread is significantly reduced. In this case, "gripper extensions" of the gripper elements can still be located axially following the internal thread arranged in the region of the gripper elements, so that an additional frictional or form-locking grip of the extractor coupling on the head part of the injection nozzle can be achieved.

Furthermore, it can be provided according to claim 3 that the gripper elements have in their free end region radially inwardly projecting pull strips. Such an embodiment is preferably provided when corresponding undercuts are provided in the region of the head part of the injection nozzle. With these undercuts, the radially inwardly projecting pull strips are correspondingly engageable, so that here is a tight fit connection after the clamping of the gripper elements is reached. In this case, the internal thread can be arranged both in a non-deformable part of the base body and in a deformable part of the gripper elements of the base body. βββ

Furthermore, it can be provided according to claim 4, that the gripper elements have to the head part directed towards clamping surfaces, which are surface-treated. By such a surface coating is an increased static friction between these clamping surfaces and the head portion of the injector reachable, so that even by this measure increased extraction forces can be applied.

In a further embodiment, it can be provided according to claim 5, that the gripper elements in the connection to the internal thread to the head part directed towards profiled surfaces, in particular thread-like jagged surfaces. Also by this measure increased extraction forces can be applied to an injector or on the headboard.

For coupling the pull-out with a pulling device, the main body of the pull-out according to claim 6, the gripper elements may be provided axially opposite with a coupling thread, via which the pull-out coupling with the pulling device can be coupled. Due to this extremely simple configuration, the pull-out is optional, for example, with a pull spindle, for example, after DE 20 2004 009 755 U1 or with a hydraulic cylinder according to the document DE 20 2004 006 602 U1 coupled.

For bracing the gripper elements against the head part may be provided according to claim 7, that the extraction coupling has an external thread on which a clamping nut can be screwed. This clamping nut has a conical inner contour towards the gripper elements, which cooperates with a conical outer circumferential surface formed by the gripper elements. Thus, when tightening the clamping nut, the gripper elements adjusted radially inwards and thus clamped against the headboard become. This embodiment in particular allows extremely easy handling.

In summary, it should be noted that extremely high pull-out forces can be applied to the head part of an injection nozzle by the combination of the radially elastically adjustable gripper elements in cooperation with the internal thread without the risk that, in particular, the external thread of the head part may tear or be damaged. In particular, the arrangement of the internal thread in the axial region of the gripper elements of great advantage, since the internal thread is "mitverspannt" and thus a stabilization of the threaded connection can be achieved by reducing the thread play.

Fig. 1

eine Seitenansicht einer ersten Ausführungsvari- ante einer erfindungsgemäßen Ausziehkupplung;

Fig. 2

eine Unteransicht II der Ausziehkupplung aus Fig. 1;

Fig. 3

einen Vertikalschnitt III-III der Ausziehkupp- lung aus Fig. 2;

Fig. 4

eine Seitenansicht einer Spannmutter;

Fig. 5

einen Vertikalschnitt der Spannmutter aus Fig. 4;

Fig. 6

den oberen Endbereich einer Einspritzdüse mit einem Kopfteil, das ein Außengewinde aufweist in Seitenansicht;

Fig. 7

die Ausziehkupplung aus den Fig. 1 bis 5 in ih- rem am Kopfteil der Einspritzdüse aus Fig. 6 an- gesetzten Zustand im Vertikalschnitt;

Fig. 8

eine zweite Ausführungsvariante einer Auszieh- kupplung im Vertikalschnitt;

Fig. 9

einen Vertikalschnitt einer dritten Ausführungs- variante einer Ausziehkupplung;

Fig. 10

eine vierte Ausführungsvariante einer erfin- dungsgemäßen Ausziehkupplung.

Reference to the drawings, the invention will be explained in more detail with reference to some embodiments. It shows:

Fig. 1

a side view of a first embodiment of an inventive Ausziehkupplung;

Fig. 2

a bottom view II of the pull-out Fig. 1 ;

Fig. 3

a vertical section III-III of Ausziehkupp- from Fig. 2 ;

Fig. 4

a side view of a clamping nut;

Fig. 5

a vertical section of the clamping nut Fig. 4 ;

Fig. 6

the upper end portion of an injection nozzle having a head portion having an external thread in a side view;

Fig. 7

the extractor from the Fig. 1 to 5 in its at the head part of the injection nozzle Fig. 6 activated state in vertical section;

Fig. 8

a second embodiment of a pull-coupling in vertical section;

Fig. 9

a vertical section of a third embodiment of a pull-out;

Fig. 10

a fourth embodiment of an inventive extraction coupling.

At this point it should be noted that all variants of the pull-out couplings in cooperation with the clamping nut from the 4 and 5 are to be used.

In the Fig. 1 to 3 is a first embodiment of a pull-out 1 is shown. It shows Fig. 1 a side view, Fig. 2 a bottom view II Fig. 1 and Fig. 3 a vertical section III-III of the extractor 1 from Fig. 2 , As can be seen from the three drawing figures, the pull-out coupling forms a base body 2 which has an outer hexagon 3 in its upper one end region, via which the main body 2 or the pull-out coupling 1 can be driven in rotation by means of a corresponding key tool. Axially adjacent to this external hexagon 3, the main body 2 has an external thread 4, onto which a clamping nut can be screwed, as will be explained in more detail later.

Following this external thread 4 a total of six radially elastically adjustable gripper elements 5 are provided in the present embodiment, which are separated accordingly by separating slots 6 from each other. Through the dividing slots 6, the radially elastic adjustability is achieved. The gripper elements 5 together form a conical lateral surface 7, so that the gripper elements 5 can be radially compressed by means of an annular or conical clamping element.

In the present embodiment, an internal thread 8 is provided approximately centrally in the region of the gripper elements 5 in the axial direction, via which the extraction coupling 1 or the base body 2 can be screwed onto a corresponding external thread of a head part of an injection nozzle. In axial extension of the hexagon socket 3 opposite form the gripper elements cylinder-section-shaped clamping surfaces 9, which are adapted in their dimensions to the dimensions of a head portion of an ejected nozzle.

For coupling the pull-out coupling 1 with a pulling device, the base body has a corresponding internal thread 10 in its upper end region.

In the 4 and 5 For example, a clamping nut 15 is shown, which is provided for the radial clamping of the gripper elements 5. The clamping nut 15 has in its upper end region also has a hexagon socket 16, via which the clamping nut 15 is correspondingly driven in rotation by means of a key tool. This clamping nut 15 has in the present embodiment an outer cylindrical surface 17 on. On the inside, the clamping nut 15 is provided with an internal thread 18, with which the clamping nut 15 can be screwed onto the external thread 4 of the pull-out coupling 1 or of the base body 2. Vertically downwards adjoins the internal thread a conically enlarged inner contour 19, the shape of which is adapted to the conical shape of the conical lateral surface 7 of the gripper elements 5.

When tightening the clamping nut 15 on the hexagon socket 16, the extraction coupling 1 and the main body 2 are held against the hexagon socket 3 of the body 2, so that a secure screwing the clamping nut 15 with its conical inner contour 19 on the conical lateral surfaces 7 of the gripper elements 5 allows becomes.

The in the FIGS. 2 and 3 shown clamping surfaces 9 may be surface-treated, so that the static friction is improved at a head portion of an injection nozzle.

Fig. 6 shows the upper end portion of an injection nozzle 25, which has an upper head portion 26. In the upper end region of this head part 26, an external thread 27 is provided, on which the pull-out coupling 1 or the base body 2 with the internal thread 8 of its gripper elements 5 can be screwed. Furthermore, in Fig. 6 nor the fuel connection piece 32 in the region of the head part 26 recognizable. Furthermore, a receiving groove 28 is provided in the lower end region of the external thread 27, which serves in the present embodiment of the injection nozzle 25 for receiving an O-ring seal 29.

Fig. 7 now shows a vertical section of the Ausziehkupplung 1 with its base body 2 in its on the head portion 26 of the injector 25 correctly scheduled state. It can be seen that the gripper elements 5 lie with their inner clamping surfaces 9 flat against a cylinder portion 30 of the head part 26 of the injection nozzle 25. Here, not necessarily clamping forces must be effected. However, the internal thread 8 of the gripper elements 5 is fixedly connected to the external thread 27 of the head part 26 of the injection nozzle 25 in connection. The clamping nut 15 is screwed onto the external thread 4 of the base body 2 and braced vertically downward in the direction of the arrow 31 against the gripper elements 5. In this in Fig. 7 shown strained position thus the game between the internal thread 8 and the external thread 27 is reduced by the radial "compression" of the gripper elements 5 against the head part 26 such that higher pull-out forces against the arrow 31 can be applied via this threaded connection. Furthermore, by further tightening the clamping nut 15 (and / or corresponding shape adaptation of the clamping surfaces 9) in the direction of the arrow 31, an additional tension of the sections beyond the internal thread 8 of the gripper elements 5 with their clamping surfaces 9 against the cylinder portion 30 of the head portion 26 causes be, which also increases the applied tensile forces against the arrow 31.

As a pulling device, the lower end of a pulling spindle 35 can be seen in the present embodiment, which is screwed into the internal thread 10 of the main body 2 and the pull-out 1 accordingly. This tension spindle 35, the tensile forces, for example by means of a pull nut in conjunction with a support cylinder, as is known from the prior art, or by means of a hydraulic cylinder with a corresponding design of a counter-holder on the pull-out 1 apply.

In the further drawing figures 8 to 10, three further variants of Ausziehkupplungen are exemplified. For the same components or components in this case, the same reference numerals are used as in the embodiment of the Fig. 1 to 3 so that the description of the extraction coupling 1 from the Fig. 1 to 3 as well Fig. 7 also on the pull-out 1 from the Fig. 8 to 10 is readable. In that regard, reference is also made to this description.

The extraction coupling 1 off Fig. 8 has in contrast to the pull-out 1 Fig. 1 additional radially inwardly directed tension strips 11, which are arranged in the lower end region of the respectively associated gripper element 5. These drawbars 11 are engageable with corresponding undercuts of this head part in a corresponding embodiment of a head portion of an injection nozzle, which is not explicitly shown in the drawing.

The extraction coupling 1 off Fig. 9 also differs in this lower end of the gripper elements 5 of the two embodiments according to the Fig. 1 to 3 respectively. Fig. 8 , In the lower end region, the gripper elements 5 are equipped on the inside with a profiled surface, in particular with a thread-like serrated surface structure 12. With this surface structure 12 is achieved at least to a small extent to a friction caused by the "pressing" of the gripper elements 5 against the head part still a kind of form closure, so that in this way the possible extraction forces are further increased. Such a configuration may, for example, also for the head part 26 with its cylinder portion 30 of the injection nozzle 25 from Fig. 7 be used. The prerequisite for an increase in the tensile effect is that this cylinder section 30 is made of a "relatively" soft material, but at least not surface-hardened.

Fig. 10 shows a further embodiment of a pull-out 1, wherein the internal thread 13 for coupling with the external thread 27 of the head portion 26 of the injection nozzle 25 from Fig. 7 is arranged in the non-deformable part of the base body 2 of the extraction coupling 1. The cylinder portion 30 of the injector 25 must for the use of this embodiment according to Fig. 10 axial length be formed (not shown in the drawing). In this embodiment, therefore, this internal thread 13 when tightening the clamping nut 15 from the 4 and 5 not clamped radially against the external thread 27 of the injection nozzle 25.

The design of the further elements, in particular the gripper elements 5, corresponds to the embodiment of the embodiment of the pull-out 1 from Fig. 1 , However, it is also conceivable here that this embodiment according to the Fig. 10 the pull-out also with drawstrings 11 or with a profiled surface in particular an internal thread 12 of the two embodiments of the 8 and 9 Is provided. In summary, it can be seen that increased tensile forces can be applied to an injection nozzle during the extraction process by means of the radially elastically tensionable gripper elements, so that destruction, in particular of a thread formed as a male thread of the head part of the injection nozzle is reliably prevented.

Claims (7)

Extracting coupling (1) with a main body (2) for a seated in a cylinder head injector (25) which on the one hand with a pulling device (35) and on the other hand with an external thread (27) of a head part (26) of the injection nozzle (25) is coupled
characterized,
that the basic body (2) has a suitably be screwed onto the external thread internal thread (8, 13) and,
in that the basic body (2) is provided in the axial extension of its internal thread (8, 13) with a plurality of radially elastically deformable gripper elements (5) which can be braced against the head part (26) of the injection nozzle (25). Pull-out coupling according to claim 1, characterized in that the internal thread (8) is arranged in the axial region of the radially elastically deformable gripper elements (5), in particular approximately centrally. Pull-out coupling according to claim 1 or 2, characterized in that the gripper elements (5) in their having free end portion radially inwardly projecting pull strips (11). Extending coupling according to claim 1 or 2, characterized in that the gripper elements (5) to the head part (26) directed towards clamping surfaces (9), which are surface-treated. Extending coupling according to Claim 1 or 2, characterized in that the gripper elements (5) have profiled surfaces, in particular thread-like serrated surfaces (12), directed towards the head part (26) following the internal thread (8). Pull-out coupling according to one of claims 1 to 5, characterized in that the base body (2) the gripper elements (5) axially opposite to an internal thread (10) is provided, via which the pull-out (1) with the pulling device (35) can be coupled. Pull-out coupling according to one of claims 1 to 6, characterized in that the base body (2) has an external thread (4), on which a clamping nut (15) can be screwed on and,
the clamping nut (15) has a conical inner contour (19) towards the gripper elements (5) and
the gripper elements (5) form an outer conical surface (7) which can be brought into operative connection with the inner contour (19) of the clamping nut (15) and can be clamped radially against the head part (26) by means of the clamping nut (15).

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