WO2009092632A1

WO2009092632A1 - Injection spigot

Info

Publication number: WO2009092632A1
Application number: PCT/EP2009/050172
Authority: WO
Inventors: Ferdinand Coerschulte; Ernst Friedrich Ischebeck
Original assignee: Friedr. Ischebeck Gmbh
Priority date: 2008-01-25
Filing date: 2009-01-08
Publication date: 2009-07-30
Also published as: ZA201004523B; CN101925720A; CA2713194A1; DE102008006233A1; AU2009207740A1; CN101925720B

Abstract

The invention relates to an injection spigot (24), preferably for an injection head for injection drilling anchors with independent supply of a first and second supply component, wherein the injection spigot (24) has a housing (34) with an internal cavity which has at least one outlet opening for the outlet of the first and the second supply component. According to the invention, an advantageous improvement may be made, wherein the wall of the housing (34) has at least one first pre-determined breaking point (35) for forming a first inlet opening (36) for a first supply component under pressurisation and at a distance therefrom at least one second pre-determined breaking point (37) to form a second inlet opening (38) for a second supply component under pressurisation. The invention further relates to an injection head for drilling and pressing of drilling injection anchors in which an injection spigot (24) is inserted.

Description

Inj ektionsstutzen

The present invention relates to an injection nozzle, preferably for a separately for supplying at least a first and a second supply component suitable injection head for Injektionsbohranker, wherein the injection nozzle has a housing which forms an inner cavity, the at least one outlet opening for the exit of the first and the second feed component.

An injection head of the type mentioned is known in the art from DE

102007008966 Al known. As described there, such an injection head is particularly suitable for drilling and pressing of so-called. Self-drilling Injektionsbohrankern in a to be stabilized ground, in the mountains or the like. Such known per se Bohrbohranker may have at its top, for example, a separate drill bit and have a continuous in their longitudinal direction injection channel, which opens at the front anchor end usually in one or more outlet openings. During drilling, a flushing medium, for example air or water, can preferably be supplied to the borehole through the injection channel when pressurized. In order to press the Injektionsbohranker in the well, then a Verpressmasse can be pressed into the Bohrlochspalt surrounding the injection drill through the flushing head and the injection channel. The flushing head is accordingly used depending on the step for the supply of detergent (eg. Water) or Verpressmasse. Particularly suitable as the molding compound are so-called two-component synthetic resins, one component of which may be a resin (for example water glass) and the other component of which may be a hardener. In order to achieve that both components harden together only in the borehole, they are supplied to the injection head separately and meet only in a lost part connected to the injection anchor. In DE 102007008966 A1, this lost part is a so-called flushing nut, which has a slightly rotatable one External thread in the inner part and with a more difficult to turn external thread on the anchor rod is to screw. After drilling in and pressing the Injektionsbohrankers the direction of rotation of the drill drive is reversed for separating the flushing head, wherein due to the different Ausschraubkräfte the flushing nut emerges as a lost part of the inner part and remains screwed to the anchor rod. It is understood from the above explanation that the conventional term rinsing means means that not only serves to rinse the bore, but also for their pressing. For a subsequent application, the injection head, a further Injektionsbohranker on the possibly already magaziniert another rinsing nut is already screwed at the end, are supplied. The known flushing nut forms a cavity in the interior and has a first inlet opening for connection to a supply line for the separate supply of a first component and second inlet openings for connection to supply lines for supplying a second component, so that the inner cavity insofar as a line connection of the supply lines forms. The inlet openings are made in the form of holes. To prevent leaks, annular grooves are provided adjacent to the holes with inserted therein O-rings. In view of the fact that the known Spülmut- ter is also used for torque transmission, it must be made of a sufficiently strong material. In particular, in connection with this, the production of this component proves to be relatively complicated with regard to the various holes, sealing grooves and types of threads, and also a certain minimum size can not be undershot, since the anchor rod must be screwed into the flushing nut. Also is at the

Use of the known flushing nut can not be ruled out that, after the separate injection of the feed components into the flushing nut and the injection anchor and subsequent switching off of the component supply or pressure shut-off, there is a certain backflow of the feed components from the flushing nut. Against this background, the invention has the object, advantageously further develop an injection nozzle of the type described above, so that in particular the aforementioned possible disadvantages are avoided as much as possible.

The object is achieved according to the invention initially and essentially in conjunction with the features that the wall of the housing at least a first predetermined breaking point to form a first inlet opening for a first supply component under pressurization and spaced therefrom at least a second predetermined breaking point to form a second inlet opening for a second feed component under pressurization. The term predetermined breaking point is understood in the context of the invention in a broad sense and includes in terms of geometric extension meaningful both the possibilities punctiform, linear or even planar extensions. The invention also includes in its general idea that the housing wall of the injection nozzle, as it were to prepare inlet openings at specific housing locations, initially has local weak points, preferably wall thickness reductions and / or localized point-like or line-shaped openings bordering the intended inlet opening, and the provision or release of the inlet opening only results as a result of a certain pressurization. In this way, as will be explained in more detail, both manufacturing and technical advantages can be achieved. First of all, in view of the fact that the inlet openings are still completely or at least essentially closed before pressurization, in particular also before use of the injection nozzles, protection against damage and contamination is achieved. It is preferably provided that the first and second predetermined breaking points are each formed on a wall region with a reduced wall thickness compared to adjacent wall regions. In particular, if in this case the wall thickness is only reduced to one (albeit possibly extremely small) wall thickness, that is none Openings are provided, the production can be simplified. An expedient design is seen in that the housing of the injection nozzle has a substantially rotationally symmetrical, preferably substantially cylindrical, wall at one longitudinal end of the outlet opening is arranged to exit the supply components in the direction of the injection anchor. At the longitudinal end opposite the outlet opening, the injection nozzle can have an end wall, on which at least one predetermined breaking point for a first inlet opening is formed. In a preferred embodiment, provision is made for the predetermined breaking point for the first inlet opening to be formed on a wall region, preferably circular, whose wall thickness decreases from outside to inside, preferably radially symmetrically and in particular linearly in the radial direction. If the wall thickness decreases as far as the midpoint, there is a point-shaped predetermined breaking point at which, as a result of pressurization by a supply component fed through the first supply line, first the break-up and then pressure-dependent further tearing of the inlet opening can occur , With respect to one or more so-called second inlet openings for the second supply component, it is preferred that one or more, preferably two, predetermined breaking points are provided on the circumference of the cylindrical wall of the injection nozzle.

In this context, it is preferable for one or more predetermined breaking points for each second inlet opening to be formed on a preferably circularly bordered wall area with wall thickness that decreases sharply compared to adjacent wall areas whose wall thickness is directed in the longitudinal direction of the injection nozzle to its longitudinal end having the outlet opening decreases, preferably decreases linearly in this direction. In order to achieve a wall region with an abruptly reduced wall thickness, a recess which virtually forms a cup can be provided in a wall with a comparatively large wall thickness. The preferred target fractured parts is located where, due to the selected geometry, the lowest wall thickness is present. After this point is broken, it may, starting there, in particular along the wall thickness transition, in the direction of increasing wall thickness of the reduced wall thickness depending on the level of pressurization to a progressive cracking, the crack shape dictates the edge contour of the inlet opening. In general, crack propagation is limited by a drop in pressure due to the existing crack and some deflection of the outlined wall area. The non-torn at the end part of the wall thickness reduced wall area takes over insofar a holding function and in an elastically deformable material as it were the function of a bending joint to which the outlined wall portion is hinged like a flap valve. With sufficiently elastic properties, it is advantageous for the flap valves to automatically spring back to their initial position during a pressure cut-off, that is to say in particular at the end of the supply of the feed components at the end of the anchor pressing process, whereby the inlet openings are essentially closed again. In this way (as with heart valves), backflow is prevented, in particular after the injection head has been detached from the injection nozzle. In the context of the invention, both within the wall thickness reduced wall areas, as well as in relation to the adjacent thicker wall areas, a variation of the wall thickness in wide value. Ratio possible. Preferably, it is provided that on the wall thickness reduced wall portion at which the predetermined breaking point is formed for the second inlet opening, the maximum wall thickness is a multiple, preferably two to four times, the minimal wall thickness occurring there and that the maximum wall thickness of this wall thickness reduced wall area is less than the wall thickness of the wall region surrounding said cup, preferably in proportion to about half or about one third. Within the scope of the invention, it is also preferred that the injection nozzle be made of plastic, in particular of polyamide, is made. In this context, it is also preferred that the injection nozzle is designed as a plastic injection molded part or produced in a plastic injection molding process.

An expedient development is seen in the fact that the cylindrical wall of the injection nozzle in its rearward longitudinal region in the region of wall thickness reduced wall portions, which are assigned to the second inlet openings, on the outside has a closed circumferential annular groove. As a result of this, the inflow of the supply component to the inlet openings distributed at the circumference can be made uniform. In particular, in a production as a plastic injection molded part is in a simple way the possibility that the cylindrical wall of the injection nozzle in a front longitudinal region between the predetermined breaking points for the second inlet openings and the outlet opening on the outside one or more, longitudinally spaced and extending in the circumferential direction, integrally formed annular projections having. This front length region can serve for inserting the injection nozzle into the injection channel (in particular into a channel widening) of the injection anchor. The terms front and back or front and back refer to the feed direction of an anchor during drilling. With suitably matched diameters, the ribs undergo a certain deformation during insertion and bear against later withdrawal of the injection nozzle from the armature, so that a desired high axial holding force can be achieved. Alternatively or in combination, there is the possibility that the cylindrical wall of the injection nozzle has, on both sides of the already mentioned circumferential groove, a circumferentially encircling, raised and integrally formed annular bead. With appropriate coordination of the diameter experienced the two annular beads when inserting the injection nozzle into a recess provided in the injection head or in its rotatable inner part a certain deformation, so that the annular beads act as seals. According to the preceding embodiments, the known flushing nut, in which the two resin components meet for the first time, is replaced by the injection nozzle according to the invention, which can be produced comparatively more cost-effectively. In particular, this can be a ready-to-install polyamide injection molded part with already integrally integrated seals and flap valves. For use, an arrangement of the injection nozzle at the end of the injection anchor, so before a possibly provided therein static mixer is preferred. Compared to the conventional flushing nut is advantageous that not the anchor rod screwed into the flushing nut, but the injection nozzle can be inserted into the anchor rod. Due to the extent possible miniaturization of the injection nozzle a great cost advantage over the consuming to be processed known flushing nut is achieved. In the inserted state of the injection nozzle, the possible circumferential ribs in its front longitudinal region as explained increase the axial holding force, which thereby preferably greater than the axial holding force between Spülkopf-inner part and injection nozzle can be selected, so that the injection nozzle when unscrewing the injection anchor from the The rinsing head is reliably automatically pulled out of the rinsing head axially and can remain as a lost component at the same time as a sealing closure on the anchor. The possible cost advantage of the invention is particularly due to the preferred use as a lost part and the extent required quantities to fruition.

The invention will be described in more detail below with reference to the accompanying figures, which show a preferred embodiment of the injection nozzle according to the invention and a preferred application. It shows:

1 in a longitudinal section of the injection nozzle according to the invention according to a first preferred embodiment, in conjunction with a preferred injection head for use after compression of a drill injection anchor;

FIG. 2 shows the arrangement shown in FIG. 1, but after the separation of the injection socket with the injection anchor;

Fig. 3 is a sectional view taken along section line III - III in Fig. 2;

4 shows a longitudinal section along section line IV - IV according to FIG. 2;

Fig. 5 is a perspective view of the arrangement shown in Fig. 2;

FIG. 6 shows the injection nozzle shown in FIG. 1, inserted into the injection anchor, with a shortened representation by means of breaks; FIG.

FIG. 7 shows the injection nozzle in an enlarged detail of detail VII in FIG. 1, with the inlet openings open; FIG.

8 shows the arrangement shown in FIG. 7, but with a new injection nozzle with inlet openings still closed;

9 shows the end of the compressed injection anchor shown in FIG. 1 after the detachment of the injection head from the injection nozzle;

Fig. 10 in perspective the injection nozzle shown in Fig. 1, but in contrast in magnification and

Fig. 11 to the injection nozzle shown in Fig. 1 is a longitudinal section, also in contrast, in magnification. With reference to FIGS. 1 to 10, the injection head 1 according to the invention is described according to a first preferred embodiment in connection with components interacting therewith. The injection head has a flushing head 2, which comprises an outer housing 3 and an inner part 4, which is rotatably received therein relative to a longitudinal axis A. To the outer housing 3 includes a first flushing ring 5, on the outside of a first supply port 6 for supplying a first, preferably liquid supply component is mounted, and a second flushing ring 7 of the first flushing ring 5 in the longitudinal direction L (ie in the direction of the longitudinal axis A ) is held axially spaced and on the outside of a second supply port 8 is mounted for the separate supply of another, preferably liquid supply component. The inner part 4 has on the rear side a connection 9 with a receiving opening 10 for receiving a connection end 11 in a rotationally positive manner from a drill drive 12 indicated only by a dashed line in its front section. The inner part has connecting means for connecting an anchor rod 14 provided with an outer armature thread 13 (cf. 6) has a threaded bore 17 (see also FIGS. 2 and 4) provided with an internal thread 16 matching the anchor thread. The threaded bore 17 with the internal thread 16 represents a connection means for connecting an anchor rod 14 provided with a corresponding external anchor thread 13. It is noted that only the rearmost anchor rod 14 of a drill injection anchor 15 is shown in the figures, but that it is shown in FIG in known manner, if necessary, several, for example, by threaded coupling nuts connected anchor rods and in particular at the top may have a drill bit. As shown in particular in FIGS. 1, 7 and 8, the rotatable inner part 4 has in its interior a first supply line 18 in communication with the first supply port 6 and four second supply circumferentially spaced by a quarter turn and in communication with the second supply port 8 19 lines. The first supply line is formed from a centrally extending in the longitudinal direction L bore 20 and two of the rear end extending radially to the surface radial bores 21. The first and second supply lines 18, 19 are directed toward a common line connection 22 in the inner cavity 23 of an injection nozzle 24. This is (see Figures 7 and 8) with its rearward longitudinal portion 25 in a axial extension of the threaded bore 17 arranged, contrast cross-section reduced and substantially cylindrical recess 26 inserted and non-positively in the region of its front length range 27 in a channel widening 28 of the injection channel 29 of Inserted into the threaded hole 17 anchor rod 14 inserted. To the first supply port 6, a supply line for a desired first supply component connected and this through the annular groove 31 in the first purge ring 5, the first supply line 18 and arranged at the end of line spring check valve 30, which opens at sufficient supply pressure, the injection nozzle 24 is supplied become. To the second supply port 8, a supply line for a further desired supply component connected and this, of the first supply component separately, through the annular groove 33 in the second purge ring 7, through the second supply lines 19 and by opening at sufficiently large supply pressure spring check valves 32 the injection nozzle 24th be supplied. As FIG 8 shows, the housing 34 of the injection nozzle 24 has a prepared first predetermined breaking point 35 for forming a first inlet opening 36 (see Figure 7) for the first supply component and spaced therefrom two second predetermined breaking points 37 to form a second inlet opening 38 (see FIG. 7). The predetermined breaking points are each formed on a wall portion 39, 40 with compared to adjacent wall portions of reduced wall thickness and are there in the range of the least wall thickness. The term breaking point is to be understood in a broad sense and includes geometrically the possibility of a point, line or area extension. If, as shown in Figure 8, a new injection nozzle used, the predetermined breaking points are not yet broken, that is, the associated inlet openings 36, 38 are still closed. The predetermined breaking points 35, 37 are in terms of their shape and dimensioning (in particular with regard to the selected minimum paint wall thickness) in each case matched to the supply pressures of the supply components usually adjustable during operation of the injection head, that they break up with appropriate pressurization, as shown in Figure 7, so that the respective inlet opening 36, 38 is opened and the there still separate feed component in the inner cavity 23 flows. Only in this cavity 23, ie at the line connection 22, it comes to the contact of the two separately supplied components (eg, resin and hardener). As illustrated particularly in FIG. 11, the inner cavity 23 has an outlet opening 41 for the common exit of the first and the second supply components in the direction of the drill injection anchor 15.

1 shows, as mentioned above, the injection head 1 after drilling a (only partially shown) Bohrinjektionsankers 15 in a wall 44 (eg., Mountains) and after pressing the Bohrinjektionsankers 15 in the formed well 45 by means of a grout 46, which was formed by mixing the two supplied through the supply ports 6, 8 supply components and then cured in the borehole. Due to the short time after mixing hardened Verpressmasse 46 is formed due to the anchor thread 13 and the unevenness in the wall of the well an effective axial shear bond. In FIG. 1, for better illustration of details, the grout 46 is only in the borehole 45, i. not reflected in the flushing head and the Bohrinjektionsanker. In FIG. 1, the drilling injection anchor 15 is drilled into the wall to a desired depth at which a support plate 47 (so-called collar plate) abuts against a ball collar nut 48, which is screwed against the rotatable inner part 4 by an internal thread a provided in front of the wall 44 delay mat 49 is pressed.

According to a method according to the invention, which is preferred in particular with regard to the application shown in FIG. In order to prepare a drilling operation, the preassembled unit shown in FIG. 6, which is shown in FIG. 6, is first supplied from at least one anchor rod 14 and an injection nozzle 24 and connected thereto. For the production of this unit was first a first, known per se. Static mixer 50, which has a plurality of longitudinally L consecutively arranged coiled so-called baffles 51, with a surrounding, in particular separate, envelope member 52, which is, for example, to a pipe or can be a hose, inserted into the injection channel 29 and axially fixed therein in an appropriate manner with the envelope member 51 so that it forms against the flow pressure of the feed components in the injection channel 29 a flow-through, axially fixed obstacle, as it flows through the various feed components undergo intensive mixing. In the exemplary embodiment selected, the injection nozzle 24, shown individually in FIG. 11, was then inserted with its front longitudinal region 27, at the front side of which the outlet opening 41 is located, into a channel widening 28 of the anchor rod 14 adjoining the static mixer 50. Due to the matched diameter, the length region 27 with the cylindrically machined channel widening 28 forms a first plug-and-press connection 53, which can only be separated again by applying a relatively high, so-called first axial force. The in the example rotationally symmetrical and substantially cylindrical outside of the injection nozzle 24 forms at the transition from the rear length region 25 to the front length region 27 by an abrupt reduction in cross-section of an axial stop surface 54, which forms an axial stop with the end face 55 of the anchor rod 14. The inner cavity 23 is formed substantially cylindrical. Therein, a second static mixer 56 is inserted and inserted against a formed with an annular step 73 of the cavity 23, rear axial stop. The terms back and front side (or back and front) are again related to the feed direction of the anchor rod during drilling. In this way, the second static mixer 56 in the longitudinal direction L, to to a permissible in the example allowed slight movement, set without a connection to the injection nozzle 24 would be necessary at its periphery (nevertheless, such a connection would also be possible). While the annular step 73 forms the rearward axial stop, forward displacement by the axially fixed static mixer 50 is prevented. For an automated drilling and pressing operation, the unit shown in Figure 6 can be pre-assembled in larger quantities and preferably supplied in particular magazined the arrangement shown in Figures 2 to 5. For connection to the injection head 1, the preassembled with the injection nozzle 24 anchor rod 14 is screwed by its anchor thread 13 in the threaded bore 17 of the rotatable inner part 4 until this (as indicated in Figure 8) at the end of the internal thread 16 and an axial stop (This may be located at the rear end of the injection nozzle 24) is not possible. In this case, the injection nozzle 24 is inserted with its rearward longitudinal region 25 into the essentially cylindrical recess 26 (cf., FIG. 2) in the longitudinal direction. The shaping or dimensioning is selected such that the rear end face 58 (see FIG. 11) of the injection nozzle 24, at which the first predetermined breaking point 35 for the first inlet opening 36 is located, comes into axial contact with one inserted into the inner part 4 Press bushing 62 and in the center channel axially fixed spring check valve 30 occurs. In this way, a front and back axial fixing of the injection nozzle 24 is achieved. In this position, shown enlarged in FIGS. 7, 8, a positioning of the second inlet openings 38 (or the second predetermined breaking points 37) in the longitudinal direction L is also relative to the outlet end of the second supply lines 19 or axially therein held spring check valves 32 ensured. As shown in the figures, located on the cylindrical wall 59 of the injection nozzle 24 at the axial position of the wall thickness reduced wall portions 40 an outer circumferential annular groove 60 which is axially aligned with the supply lines 19. The rear longitudinal region 25 of the injection nozzle 24 forms with the recess 26 in the inner part 4 a second plug-and-press connection 61, where in the transferable from this compound 61 so-called. Second axial force is less than the transferable from the first male-press connection 53 first axial force. If the injection head 24 or its rotatable inner part 4 is later unscrewed again from the anchor rod 14 (preferably by reversing the direction of rotation on the drill drive), the injection nozzle 24 automatically becomes due to the axial forces that can be transmitted by the two plug-and-press connections 53, 61 with pulled out of the inner part 4 and can remain as a lost part at the end of Injektionsbohrankers. To start from the installation state shown in FIG. 8, in which the first and second predetermined breaking points 35, 37 are not yet broken, ie the first and second inlet openings 36, 38 are still closed, in the position shown in FIG ) State is supplied through the supply ports 6, 8, the respective individual supply component under pressure, whereby the spring check valves 30, 32 open the respective supply components against the wall thickness reduced wall portions 39, 40 press and break the predetermined breaking points 35, 37, so that the inlet openings 36, 38 are released. In the example chosen, the injection nozzle 24 is a component produced in one piece from the plastic polyamide by injection molding.

Another special feature of the injection head shown as an embodiment is that a releasable coupling-fuse for the torque-transmitting terminal end 11 of the drill drive 12 is realized thereon. This is due to the fact that, as illustrated in particular FIGS. 3 and 4, there are two securing elements 64, which in the example are dowel pins 65, and in that the inner part 4 extends in a cross-section perpendicular to the longitudinal direction L at the receiving opening 10 Q has two parallel spaced through holes 66, which serve as mounting holes 68 for the dowel pins, which are adapted in their diameter to a releasable clamping fastening of the dowel pins. Suitable dowel pins can be obtained commercially and are with regard to their general Functionality known. The lateral spacing a of the through holes 66 is smaller than the diameter D of the adjacent longitudinal portion 67 of the receiving opening 10 is selected. This means that in Befestigungsbzw. Clamping state of the dowel pins 65, the cross section of the receiving opening 10 is reduced compared to the state without dowel pins 65. In the embodiment, a drill drive 12 was selected, the connection end 11 spaced behind its connection portion 69 has a circumferentially extending projection 70 whose diameter substantially corresponds to the diameter D. The projection 70 is replaced by the releasable securing elements 64, the meaning of a form-locking locking projection which in a longitudinal projection direction (along the longitudinal direction L) radially overlaps the securing elements 64 in the inserted state and thereby forms a longitudinally L form-fitting releasable separation fuse with connected Bohrantriebs- connecting end , In the example shown, the connection section 69 of the drill drive connection end 11 extending up to the front free longitudinal end is provided with an external thread 71 for torque transmission, which fits to an internal thread 72 provided in a longitudinal section of the receiving opening 10. By means of the aforesaid features it is achieved that, when the direction of rotation of the auger drive 12 is reversed to separate from the drilling injection anchor 15, the inner part 4 can not rotate away from the auger drive end 11, so that a constant torque transmission and thereby a safe operation is guaranteed. Detachment of the drill drive 12 from the flushing head 2 is made possible only by the fact that the tensioning pins 65 are each actuated by a control that is generally known to a person skilled in the art

Holes 66 are removed. The dowel pins 65 are selected to withstand the centrifugal forces encountered during operation and the drill-hitting stress.

Further features of the exemplified preferred embodiment of the injection nozzle according to the invention are described below with reference to FIG. train to Figures 6 to 11 explained in more detail. In particular, Fig. 10 clearly shows that the injection nozzle is designed as a substantially rotationally symmetrical sleeve part. 11, it is shown that the predetermined breaking point 35 for the first entry opening 36 (see FIG. 7) is formed on the rear end wall 58 on a wall area 39 which is circular in this respect, the wall thickness of which is radially symmetrical linearly from outside to inside a small fraction of the edge wall thickness decreases. At the predetermined breaking point 35, the wall thickness can be reduced, in particular to a membrane-like or foil-like residual strength, so that tearing occurs even at a comparatively low pressure. Fig. 7 shows the assuming star-shaped outgoing from the predetermined breaking point 35 tear lines in the wall 39, the first formed inlet opening 36, through which the supplied through the first supply line 18 first supply component is fed into the interior 23. Although FIG. 1 shows the state after pressing of the injection anchor, the open position of the inlet openings 36, 38 is shown in the enlargement according to FIG. 7, which then merges resiliently into a closed position of the wall sections. Correspondingly, FIG. 9 shows that the wall thicknesses reduced wall regions 39, 40 automatically deform back again after the rinsing head has been twisted off due to the elastic property of the plastic used, so that the inlet openings 36, 38 are essentially closed again. For a clear representation, however, the injection nozzle 24 and the drilling injection anchor 15 are also shown in FIG. 9 without the compression compound 46 still present there. 10 and 11 also show that the two circumferentially opposite predetermined breaking points 37 for a respective second inlet opening 38 (see Fig. 7) in each case at a circular walled wall region 40 with respect to adjacent wall areas abruptly reduced wall thickness lie. While the inner wall of the cavity 23 is cylindrical, the outer side of the wall portions 40 is formed flat and extends at an acute angle with respect to the longitudinal direction L. Each wall region 40 forms an inclined extension in this respect. the flat bottom of a in the housing wall axially at the level of the annular groove 60 formed cup-like recess. By the described shaping the position of the predetermined breaking point 37 is specified at the location of the lowest wall thickness. It is that intersection of the circular edge line of wall portion 40 with the sectional plane of Fig. 11, which faces the front length portion 27 and the outlet opening 41. The terms front and back or front and back refer here as above to the feed direction when drilling the anchor.

After rupturing of the predetermined breaking point 37, a crack propagation occurs along a part of the circular edge line of wall region 40, as shown in FIG. 7. The outlined section of the wall region 40 is deflected inward by the application of pressure and forms as it were a flap valve with a valve flap 76, which is articulated on a bending joint 77. The latter is formed by a part of the wall region 40, which has not been reached by the crack due to its greater wall thickness compared to the predetermined breaking point 37. FIGS. 10 and 11 also show that the cylindrical wall 59 in the front longitudinal region 27 between the predetermined breaking points 37 and the outlet opening 41 has on the outside a multiplicity of annular projections or ribs 63 which are spaced apart in the longitudinal direction L. On the cylindrical wall 59 is provided on both sides of the circumferential groove 60 per a circumferentially annular, raised and integrally molded annular bead 78 for sealing the annular groove 60.

All disclosed features are essential to the invention. The disclosure of the associated / attached priority documents (copy of the prior application) is hereby also incorporated in full in the disclosure of the application, also for the purpose of including features of these documents in claims of the present application.

Claims

1. Injection nozzle, in particular for a suitable for separate supply of at least a first and a second supply component injection head for Injektionsbohranker, wherein the injection nozzle has a housing which forms an inner cavity having at least one outlet opening for exiting the first and the second supply component , characterized in that the wall of the housing (34) at least a first predetermined breaking point (35) for forming a first inlet opening (36) for a first supply component below

Pressurization and spaced therefrom at least a second predetermined breaking point (37) for forming a second inlet opening (38) for a second supply component under pressurization.

2. injection nozzle according to claim 1 or in particular according thereto, characterized in that the first and second predetermined breaking points (35, 37) are each formed on a wall region (39, 40) with reduced compared to adjacent wall regions wall thickness.

3. injection nozzle according to one or more of the preceding claims or in particular according thereto, characterized in that the housing (34) of the injection nozzle (24) has a substantially rotationally symmetrical, in particular substantially cylindrical, wall, at one longitudinal end of the outlet opening (41) is arranged.

4. Injection nozzle according to one or more of the preceding claims or in particular according thereto, characterized in that the injection nozzle (24) at the outlet opening (41) opposite longitudinal end has an end wall (58) on which the predetermined breaking point (35) for the first inlet opening (36) is formed.

5. Injection nozzle according to one or more of the preceding claims or in particular according thereto, characterized in that the predetermined breaking point (35) for the first inlet opening (36) on one, in particular circular edged, wall portion (39) is formed, whose wall thickness from the outside decreases inwardly, in particular radially symmetrical and / or linear.

6. Injection nozzle according to one or more of the preceding claims or in particular according thereto, characterized in that on the circumference of the cylindrical wall (59) of the injection nozzle (24) one or more, in particular two on the circumference opposite, predetermined breaking points (37) for each a second inlet opening (38) are formed.

7. Injection nozzle according to one or more of the preceding claims or in particular according thereto, characterized in that one or more predetermined breaking points (37) for each second inlet opening (38) at a particular circular walled wall area (40) with respect to adjacent wall areas abruptly reduced

Wall thickness is formed, the wall thickness in the longitudinal direction (L) of the injection nozzle (24) to the outlet opening (41) having directed longitudinal end towards decreases, in particular in this direction decreases linearly.

8. Injection nozzle according to one or more of the preceding claims or in particular according thereto, characterized in that on the wall thickness reduced wall portion (40) on which the predetermined breaking point (37) for the second predetermined breaking point (38) is formed, the maximum wall thickness a multiple, in particular two to four times, the minimum wall thickness is and that the maximum wall thickness of the This wall thickness reduced wall area (40) is less than the wall thickness of the surrounding wall area, in particular in relation to about half or about one third.

9. injection nozzle according to one or more of the preceding claims or in particular according thereto, characterized in that the injection nozzle (24) made of plastic, in particular of polyamide, is produced.

10. Injection nozzle according to one or more of the preceding claims or in particular according thereto, characterized in that the injection nozzle (24) is produced by plastic injection molding.

11. Injection nozzle according to one or more of the preceding claims or in particular according thereto, characterized in that the cylindrical wall (59) in a rearward length region (25) in the region of wall thickness reduced wall portions (40) for the second inlet openings (38) on the outside a having circumferential annular groove (60).

12. Injection nozzle according to one or more of the preceding claims or in particular according thereto, characterized in that the cylindrical wall (59) in a front longitudinal region (27) between the predetermined breaking points (37) for the second inlet opening (38) and the outlet opening (41). on the outside one or more, in the longitudinal direction

(L) spaced and extending in the circumferential direction integrally molded ribs (63).

13. Injection nozzle according to one or more of the preceding claims or in particular according thereto, characterized in that the cylindrical wall (59) on both sides of the circumferential groove (60) one each Having on the circumference circumferential raised, integrally molded annular bead (78).

14. Injection nozzle according to one or more of the preceding claims or in particular according thereto, characterized in that the cylindrical wall (59) at the transition from the rear (25) to the front (27) length region has a sudden reduction in cross section to form an axial stop surface (54) ,

15. Injection nozzle according to one or more of the preceding claims or in particular according thereto, characterized in that the inner cavity (23) is formed substantially cylindrical and therein a static mixer (56) against an axial stop (57) is inserted.

16. Injection nozzle according to one or more of the preceding claims or in particular according thereto, characterized in that the injection nozzle (24) in its installed state in the front, the annular projections having the longitudinal region (27) in the injection channel (29) of an anchor rod (14) or in a widening (28) of the injection channel (29) in the longitudinal direction (L) is frictionally inserted.

17. Injection head for boring and for pressing drill injection anchors, characterized in that an injection nozzle according to one or more of the preceding claims is inserted into the injection head.