Detachable expanding bolt, connection arrangement and method for creating such a connection arrangement

Description

[0001] The invention relates to a detachable expansion bolt with an expansion sleeve with a first end, a second end, a cylindrical outer surface and on the inside with an inner conical section whose cross-sectional area tapers towards the second end, a conical bolt with a conical section which cooperates with the inner conical section of the expansion sleeve for expanding the same as a result of an axial relative movement of the expansion sleeve and the conical bolt, and a clamping device connected to the end section providing the first end of the expansion sleeve for adjusting the conical bolt in the axial direction relative to the expansion sleeve.

[0002] Expansion bolts are used to create positive-locking connections, such as flange connections, when particularly high torques or transverse forces relative to the flange axis must be transmitted. One application area for such expansion bolts is in wind turbines, for example, to create a torsionally rigid connection between two shaft flanges in the drive train.

[0003] Expansion bolts are often used for such positive-locking connections, the bolts of which engage in a blind bore. An expansion bolt of the type in question comprises a bolt which can have a threaded section as an anchoring means, with which the bolt is secured in an internally threaded bore in a blind bore of a first assembly part. An anchoring acting in the axial direction of the bolt is required to apply the desired tensile forces when tightening the bolt. This bolt has a truncated conical section which acts on an expansion sleeve sitting on it and having a complementary internal conical contour. Such a bolt is therefore also referred to in this discussion as a conical bolt. The conical section is tapered away from the anchoring means of the conical bolt. The taper is thus designed in the direction of the opening of the blind bore.By moving the expansion sleeve relative to the conical bolt in the axial direction, the former can be expanded. The expansion sleeve is typically slotted. Such an expansion bolt is known from EP 2 191 150 B1. In this previously known expansion bolt, the expansion sleeve has an external thread in the section protruding from a mounting hole. At the end opposite the anchoring means, designed as a threaded section, the conical bolt has a threaded section onto which a clamping nut, typically with an external tool contour for attaching a clamping tool, is screwed. A clamping nut is screwed onto the external threaded section of the expansion sleeve. After the conical bolt, with its anchoring means designed as a threaded section, has been secured in the blind hole of a first mounting part, the expansion sleeve is inserted into the mounting hole.Care must be taken to ensure that a gap remains between the clamping nut and the outside of the second assembly part. The clamping nut is then screwed onto the threaded section of the conical bolt until it rests against the expansion sleeve. By screwing it further, and against the background of the anchoring of the conical bolt in the blind hole, the expansion sleeve is pressed into the assembly hole against the taper of the conical section directed towards the clamping screw as well as the inner conical contour of the expansion sleeve. This causes the expansion sleeve to expand until the previously described gap is closed. The radial preload, which is introduced via the expansion sleeve into the wall surrounding the assembly hole of the two assembly parts to be clamped, can be adjusted via the gap width between the clamping nut and the outside of the second assembly part before tightening the clamping nut.Further tightening of the clamping nut after closing the gap generates the desired axial force on the assembly parts to be clamped together.

[0004] Another expansion bolt is known from EP 3 658 785 B1. In this expansion bolt, the conical sections taper towards the thread provided on the base side with respect to the conical bolt, with which the expansion bolt is connected to the clamping abutment. In this expansion bolt, the expansion sleeve has a clamping flange protruding in the radial direction. Between the clamping flange and the surface of the mounting part arranged on the operator side is the clamping device, which is clamped via a plurality of circumferentially distributed clamping bolts while simultaneously being supported on the surface of the mounting part on the operator side. In this respect, with this expansion bolt, the sleeve is pulled out of the expansion bolt bore of the mounting parts that accommodates the expansion bolt. The advantage of this expansion bolt is that it can be released using simple means by applying a release force acting in the axial direction. This is sometimes necessary.

[0005] In addition to expansion bolts of the type described above, those are also used in which the expansion bolt is not connected to an axial clamping abutment, be it a threaded hole in the assembly part remote from the operating side or an abutment nut, where the expansion bolt with its threaded section penetrates the assembly parts to be joined and a threaded bearing nut is screwed onto the threaded section. These expansion bolts are used when, above all, transverse forces with respect to the axis of the expansion bolt between the assembly parts to be joined must be absorbed. In this expansion bolt, the conical taper of the expansion sleeve and that of the cooperating conical bolt are oriented towards the operating side. This expansion bolt is clamped by applying a tensile force to the conical bolt.

[0006] The expansion bolts described above have in common that, in order to tighten them, the clamping tool must be supported on the surface of a mounting part facing the operating side. This implies that sufficient space must be available on the outside of the mounting parts to be joined in the radial direction of the expansion bolt bore, specifically for accommodating the clamping device and for attaching a clamping tool. This is not always the case.

[0007] Such expansion bolts are typically tightened using hydraulic clamping tools operated at very high pressures (typically several hundred bar). A jet of oil escaping from a leak can cause serious injury. From a safety perspective, this is particularly problematic when such expansion bolts are located in a confined space, such as inside a hollow shaft, and must be tightened there. This is necessary, for example, when connecting the rotor shaft of a wind turbine to the gear shaft. For this purpose, a tradesperson must enter the hollow shaft with the clamping tool. In the event of a leak in the hydraulic system, the tradesperson cannot escape the danger zone quickly enough to protect themselves from injury.

[0008] Clamping bolts are known from US 4 135 432 and US 2004 / 0136802 A1, whose expansion sleeve is anchored in a borehole with a positive fit in the axial direction. These expansion bolts are non-removable.

[0009] Based on the prior art discussed above, the invention is therefore based on the object of proposing an expansion bolt which can not only be used in confined installation conditions, but whose clamping is also possible using simpler means.

[0010] The object relating to the expansion bolt is achieved according to the invention by an expansion bolt mentioned at the outset having the features of claim 1.

[0011] The method-related problem is solved according to the invention by a method having the features of claim 15.

[0012] This expansion bolt does not require an axially acting abutment in order to be tensioned. When tensioned, this expansion bolt represents a closed force system. This is particularly advantageous because it can therefore be clamped in an unthreaded bore, especially an unthreaded blind bore. This is achieved by moving the conical bolt to tighten the expansion bolt in order to expand the expansion sleeve. This movement of the conical bolt occurs in the axial direction away from the operating side, and the pressure bolt is supported in a form-fitting manner on the conical sleeve, acting in the axial direction. This expansion bolt therefore does not require an additional clamping abutment, as is the case with conventional expansion bolts.Since the conical bolt of this expansion bolt is pressed into the expansion sleeve according to the intended orientation of the conical tapers, no surface area of ​​the mounting part on the operator side is required to accommodate a clamping abutment. This explains the extremely small space requirement of such an expansion bolt. The expansion bolt itself requires no more installation space than is already provided by the expansion bolt bore. This means that this expansion bolt can be designed so that it does not protrude radially beyond the outer diameter of the expansion bolt bore. Since the pressure bolt is positioned centrally with respect to the longitudinal axis of the expansion bolt, the space required to accommodate a clamping tool is also reduced to a necessary minimum. This is determined solely by the size of the clamping tool used.Due to the central arrangement of the single pressure bolt intended for expanding this expansion bolt, it can be tightened with a relatively small clamping tool, thus clamping the expansion bolt. Such an expansion bolt can easily be clamped even with larger diameters using a powered clamping tool, such as a pneumatic screwdriver or electrically with a powerful cordless screwdriver.

[0013] It is advantageous if such a clamping tool has a coaxial reaction arm connected to its force transmission head, which is engaged with its drive contour to tighten the pressure bolt of the expansion bolt. This reaction arm is supported in a form-fitting manner in the direction of rotation on structures provided on the operating end of the expansion bolt. This support can also be used to ensure that the expansion sleeve remains stationary and that tightening the pressure bolt solely leads to an axial adjustment movement of the conical bolt within the expansion sleeve. Such a reaction arm support is generally not required. The expansion bolt can also be clamped without such a reaction arm support or with a different reaction arm support. In such a case, the frictional connection between the outer cylindrical surface of the expansion sleeve and the inner wall of the expansion bolt bore is utilized.

[0014] It is entirely possible to design an expansion sleeve for such an expansion bolt with clamping structures on the outside, such as circumferentially arranged clamping ribs, which are pressed into the wall of the expansion bolt bore as the expansion sleeve expands. This allows the expansion bolt to also positively transmit axial forces between the assembly components.

[0015] According to one design of such an expansion bolt, the pressure bolt engages the expansion sleeve at its first end section—the end section facing the operating side—via a thread. This allows the pressure bolt to be positively supported axially on the expansion sleeve and, at the same time, to be axially adjustable relative to the expansion sleeve due to the possibility of screwing it in. This design is particularly suitable for expansion bolts with smaller diameters.

[0016] According to another embodiment, the pressure bolt is held on the expansion sleeve with the interposition of an abutment body and is adjustable relative to it in the axial direction. This abutment body is connected to the first end section of the expansion sleeve in a form-fitting manner in the axial direction. Furthermore, such an abutment body has a central through-bore equipped with an internal thread. The pressure bolt passes through this through-bore and meshes with this internal thread. Even with such a configuration, the force flow is closed when the expansion bolt is tightened. According to a preferred embodiment, the abutment body is screwed to the expansion sleeve. However, a different type of connection that is form-fitting in the axial direction can also be provided at this point, for example a plug-and-turn connection similar to a bayonet lock.If a threaded connection is provided between the expansion sleeve and the abutment body, the expansion sleeve has an internal thread in its first end section, and the abutment body has a complementary external thread. Even with this design, no more space is required in the radial direction than the diameter of the expansion sleeve.

[0017] When designing an expansion bolt with such an abutment body, which is connected and held to the expansion sleeve by means of a thread, it is expedient if this screw connection is equipped with a stop which limits the screw-in depth of the abutment body. According to one embodiment, an externally projecting, circumferential stop flange is provided on the abutment body for this purpose, which acts against the end face of the first end of the expansion sleeve. According to another embodiment, a stop is located within the expansion sleeve, against which the abutment body acts. With such a configuration, the stop shoulder located within the expansion sleeve can be designed to such a depth that the abutment body, with the pressure bolt passing through it, is completely immersed in the first end section of the expansion sleeve when the expansion bolt is tensioned, and therefore does not protrude beyond the first end of the expansion sleeve.The advantage of such a design is that, if the two mounting parts are flanges for connecting, for example, two shaft parts, no fasteners protrude from the top surfaces of the flanges. In this case, the first end section of the expansion sleeve can also have support structures for the torque-locking connection of a reaction arm of a clamping tool.

[0018] In an alternative embodiment, the reaction arm of the clamping tool can be supported on the abutment body. In this case, the support structures for the torque-locking connection of the reaction arm are provided on the abutment body instead of on the conical sleeve. In the latter embodiment, the thread direction between the internal thread of the abutment body and its external thread is preferably opposite to each other, so that there is no risk of the screw connection between the abutment body and the expansion sleeve becoming loose when tightening the pressure bolt.

[0019] The design of an expansion bolt, whose pressure bolt is connected to the expansion sleeve via an interposed abutment body, is particularly suitable for expansion bolts with a larger diameter. In such a case, it is expedient to arrange a pressure distribution element between the base of the pressure bolt, i.e., the end of the pressure bolt opposite its drive contour, and the conical bolt. Such a pressure distribution element typically distributes the clamping force of the pressure bolt, which is directed only toward the center area due to the smaller diameter of the pressure bolt compared to the diameter of the conical bolt, to the available surface of the end of the conical bolt facing the pressure bolt.It has proven advantageous if the clamping force for axially adjusting the conical bolt to tighten the expansion bolt is applied to the conical bolt circumferentially in its outer edge area rather than just in a limited central area. If such a force transmission from the pressure bolt to the conical bolt is intended, the force distribution element can be designed like a disc and carry a circumferential pressure ring on its side facing the conical bolt in the area of ​​its radial end.

[0020] The expansion bolt according to the invention can also be released using simple means. This is because, to tighten the expansion bolt, the conical bolt is pressed axially into the expansion sleeve. Therefore, this expansion bolt can be easily released by pulling the conical bolt out of the expansion sleeve. The expansion sleeve itself or the outer side of an abutment body typically forms the counterbearing. In order to pull the conical bolt out of its clamping position within the expansion sleeve, a negative contour is provided centrally in the end face of the conical bolt facing the pressure bolt, as a connecting contour, to which a connecting part of a release tool can be positively connected in the axial direction. Such a connecting contour can be, for example, an internal thread or a component of a bayonet lock.To release the expansion bolt, this connecting contour is made accessible. Depending on the design of the expansion bolt, this may require only unscrewing the thrust bolt or unscrewing the abutment body together with the thrust bolt from the threaded sleeve and, if present, removing the force distribution element. The connecting contour is then accessible from the axial direction on the operating side.

[0021] In a configuration in which the operator-side side of the expansion bolt has at least one support structure for supporting the torque of a reaction arm of a clamping tool, it is expedient if several support structures are present and these are arranged concentrically to the pressure bolt and at the same angular distance from one another. The reaction arm to be engaged with it is designed coaxially and has a corresponding complementary engagement contour.

[0022] In a connection arrangement in which at least two assembly parts are to be connected to one another by such an expansion bolt, it is expedient to provide a stop shoulder within the expansion bolt bore of a assembly part to define the insertion depth of the expansion bolt. This stop shoulder acts against the free end face or a shoulder on the outer diameter of the expansion sleeve.

[0023] A connecting arrangement comprising at least two assembly parts to be connected to each other and at least one expansion bolt of the type mentioned above is created as follows: First, the assembly parts to be joined are arranged in such a way that their expansion bolt bores are aligned, i.e., coaxial. The expansion bolt to be inserted into it is pre-assembled, i.e., the conical bolt is inserted into the expansion sleeve and fixed by the clamping devices, and if necessary, even slightly pre-tensioned. This means that the pressure bolt is also screwed into the expansion sleeve, if necessary with the interposition of an abutment body. This pre-assembled expansion bolt is inserted into the coaxial expansion bolt bores from one side - the operating side of the connection arrangement - preferably up to a stop shoulder located in the expansion bolt bore. This actuates the stop shoulder of the expansion sleeve pointing in this direction, preferably against the free end face of the expansion sleeve.Such a stop shoulder is typically located at a depth within the expansion bolt bore so that, depending on the design of the expansion bolt, the cones cover the two mounting parts in the desired ratio. Due to the design of the expansion bolt, it can be inserted into an expansion bolt bore with its expansion sleeve so that it is flush with the adjacent surface of the mounting part facing the operating side. This is easily possible with the described design of the expansion bolt, as the expansion sleeve remains stationary within the expansion bolt bores when the expansion bolt is tightened. The expansion bolt is then tightened. For this purpose, a motor-driven clamping tool is typically placed on the pressure bolt. This is typically an electric tool, in particular a battery-operated tool such as a cordless screwdriver with a corresponding receptacle for the drive contour of the pressure bolt.Such a clamping tool preferably has a reaction arm, via which the reaction torque on the expansion sleeve resulting from the tightening torque is supported. Alternatively, the reaction torque can also be supported on one or more components that are positively connected to the expansion sleeve. The screwing-in process is preferably carried out in a path-controlled manner, which means that a certain screwing action must be exerted in order to move the conical bolt in the expansion sleeve by a defined adjustment path until the expansion bolt is clamped as intended. When using a driven clamping tool, such as a cordless screwdriver, the path is recorded via the existing motor control system, in which the changes in the rotational angle of the rotor or the output shaft are detected.The travel control process for tightening the expansion bolt with a specified radial preload begins when a certain pre-tightening torque has been applied to the expansion bolt to eliminate the play required to insert the expansion bolt into the expansion bore. Ultimately, only the adjustment path that also introduces a radial preload into the wall of the expansion bolt bores should influence the control. The advantage of this type of travel control is that friction within the expansion bolt, which influences torque control for tightening such an expansion bolt, does not adversely affect the radial preload to be applied.

[0024] The connecting assembly can also be easily removed again. To do this, the pressure bolt is first unscrewed. The conical bolt is then pulled out by applying a tensile force to it. This tensile force can be applied, for example, by a threaded rod screwed into the expansion sleeve. Preferably, the expansion sleeve is supported to apply the tensile force acting on the threaded rod, for example, with a nut or a suitable tool.

[0025] The invention is described below using an exemplary embodiment with reference to the accompanying figures. They show: Fig. 1: A perspective view of an expansion bolt according to the invention, shown in the manner of an exploded view, Fig. 2: a sectional view of a connection arrangement using the expansion bolt of the Figure 1with expansion bolt not tensioned, Fig. 3: the connection arrangement of the Figure 2 with tensioned expansion bolt, Fig. 4: a representation corresponding to that of the Figure 3 to represent the flow of force when tightening the expansion bolt. Fig. 5: a sectional view of the connection arrangement of Figures 2 to 4 with a release tool for releasing the expansion bolt before actuating the release tool, Fig. 6: the connection arrangement of the Figure 5 with the loosened expansion bolt and Fig. 7: a sectional view of a connection arrangement with opposite Figure 2 alternative axial positioning of the expansion bolt relative to the joint between the assembly parts.

[0026] An expansion bolt 1 comprises an expansion sleeve 2, a conical bolt 3, and a clamping device 4. The expansion sleeve 1 of the exemplary embodiment shown has a cylindrical outer surface and is divided into two parts with respect to its expandability. A section 6 encompassing the second end 5 of the expansion sleeve is equipped on the inside with a conical surface tapering towards the second end 5 (as can be seen in the sectional views of the Figures 2 to 6 ). This section 6 is slotted. In Figure 1Such a slot 7 can be seen. In the illustrated embodiment, the section 6 has two diametrically opposed slots 7. The slots 7 serve the purpose of allowing the section 6 to be widened, and thus spread. This section 6 can therefore also be referred to as an expanding section. Adjoining the section 6 is a section 9 carrying the first end 8 of the expansion sleeve 2, which is also referred to as the first end section in the context of this explanation. The inner wall structuring of the first end section 9 is described below. Figure 2 described.

[0027] The first end 8 of the expansion sleeve 2 is provided with several support structures 10 arranged at equal angular spacing from one another, enabling a positive connection to a matching mating contour of a reaction arm of a clamping tool. In the preferred embodiment, these support structures are designed like the crown end of a castellated nut.

[0028] The conical bolt 3 of the illustrated embodiment is conically tapered along its entire longitudinal extent with its outer surface. The conical section thus extends over the entire axial extent of the conical bolt 3. The taper angle of the conical bolt 3 and that of the inner wall of the expansion section 6 of the expansion sleeve 2 are identical. At least one thread 11 is incorporated into the conical bolt 3 for attaching a release device to it. The thread 11 is shown as an internal thread.

[0029] A clamping device 4 is used to clamp the expansion bolt 1. In the illustrated embodiment, this comprises three components, namely a pressure bolt 12, an abutment body 13 and a force distribution element 14. The abutment body 13 is designed to be inserted into the first end section 6 of the expansion sleeve 2 and to be clamped with the expansion sleeve 2 in the axial direction. For this purpose, the abutment body 13 has an external thread section 15, which engages with a complementary internal thread 16 of the expansion sleeve 2 in its first end section 6 (see Figure 2) interacts. If the abutment body 13 is engaged with its external thread section 15 in the internal thread 16 of the expansion sleeve 2, it is connected to the expansion sleeve 2 in a form-fitting manner in the axial direction and held by it. The abutment body 13 further has a stop flange 17 arranged above the external thread section 15, which projects beyond the external thread section 15 in the radial direction. The stop flange 17 serves to limit a screwing movement of the abutment body 13 into the first end section 6 of the expansion sleeve 2. For this purpose, the expansion sleeve 2 carries in its first end section 6 a stop shoulder 18, against which the stop flange 17 of the abutment body 13 acts (see Figure 2). For screwing in and, in particular, for clamping the abutment body 13 with the expansion sleeve 2, the former has a rotary drive contour 19 on its upper side, which in the illustrated embodiment is designed as a hexagon. The abutment body 13 has a central through-bore 20. This is equipped with an internal thread.

[0030] The pressure bolt 12, with which the expansion bolt 1 is tightened, has a drive contour 21 at one end, which in the illustrated embodiment is also designed as a hexagon. Adjacent to the drive contour 21 is a threaded portion 22 with an external thread complementary to the internal thread of the abutment body 13. The pressure bolt 12 thus meshes with its threaded portion 22 with the internal thread of the through-hole 20.

[0031] With its foot 23 opposite the drive contour 21, the pressure bolt 12 is supported on the force distribution element 14. The force distribution element 14 is designed in the manner of a disc, specifically with a diameter such that it can be inserted into the first end section 6 of the expansion sleeve 2 with the necessary radial play. The force distribution element 14 of the illustrated embodiment has a pin 24 formed on the side facing away from the pressure bolt 12, which engages the drive contour 11 of the conical bolt 3.

[0032] The assembled and thus pre-assembled expansion bolt 1 is inserted into the coaxially arranged expansion bolt holes of two assembly parts 25, 26 to be connected to each other, in Figure 2shown. The expansion bolt 1 is pre-assembled by inserting the conical bolt 3 into the expansion sleeve 2 so that the two interacting conical surfaces bear against one another. The force distribution element 14 is then pushed into the expansion sleeve 2. The abutment body 3, with or without the pressure bolt 12 threaded into it, is then inserted into the expansion sleeve 2 with its external thread section 15 onto the internal thread 16 of the expansion sleeve 2 until the stop flange 17 of the abutment body 13 bears against the stop shoulder 18 of the expansion sleeve, so that the abutment body 13 can be clamped with its stop flange 17 to the stop shoulder 18 of the expansion sleeve 2. In the illustrated embodiment, the stop surfaces which interact with one another in this regard are inclined at an angle of 45° in the direction of the longitudinal axis of the expansion bolt 1.The 45° inclination of the interacting stop surfaces in the direction of the longitudinal axis provided in the illustrated embodiment can certainly be designed differently. For example, an alignment of the interacting stop surfaces of 90° relative to the longitudinal axis or other angles are also possible. If the pressure bolt 12 has not been mounted together with the abutment body 13, the pressure bolt 12 is finally screwed with its threaded portion 22 into the through-bore 20 of the abutment body 13, which is equipped with an internal thread. In this respect, the expansion bolt 1 together with the clamping device 4 can be handled as a single piece. None of the components of the expansion bolt 1 protrude beyond the outer diameter of the cylindrical outer surface of the expansion sleeve 2.

[0033] The expansion bolt bore of the mounting part 26 has a stop shoulder 27, which reduces the diameter of the expansion bolt bore. This stop shoulder 27 acts against the free end face of the expansion sleeve 2, which provides the second end 5, to position the expansion bolt 1 relative to the joint between the mounting parts 25 and 26.

[0034] In an alternative embodiment, both the bore in the first assembly part and the expansion sleeve in the area of ​​the first end section are designed with a larger diameter than the bore in the second assembly part. This creates a stop shoulder in the axial direction between the expansion sleeve 2 and the first assembly part, which is used to position the expansion bolt relative to the joint.

[0035] In another alternative embodiment, both the bore in the first assembly part and the expansion sleeve up to the parting line are designed with a larger diameter than the bore in the second assembly part. This creates a stop shoulder in the axial direction between the expansion sleeve and the second assembly part, which is used to position the expansion bolt relative to the parting line.

[0036] In Figure 7 The two alternatives for supporting an expansion sleeve 2.1 in the expansion bolt bore mentioned above are shown cumulatively. The expansion sleeve 2.1 has a stop shoulder at the free end of the first section. This stop is in Figure 7identified by the reference numeral 27.1. A second stop shoulder 27.2 is located within the expansion bolt bore in the mounting part 25.1. A third stop shoulder 27.3 is located in the area of ​​the joint between the two mounting parts 25.1, 26.1. This illustration serves to illustrate the different possibilities for designing a stop shoulder to limit the insertion movement of the expansion sleeve 2.1 into the expansion bolt bores. Typically, only one stop shoulder is provided.

[0037] To tighten the expansion bolt 1, a suitable clamping tool is used, which is placed on the drive contour 21 of the pressure bolt 12. A cordless screwdriver is preferably used as the clamping tool. In addition to its tool, which can be placed on the drive contour 21 of the pressure bolt 12, this clamping tool has an annular reaction arm that encloses the actual clamping tool as a sleeve, the free end face of which is designed to complement the structures 10 of the first end 8 of the expansion sleeve 2. In this respect, a positive engagement is established between the reaction arm of the clamping tool and the expansion sleeve 2. The reaction arm does not rotate during a clamping movement of the tool connected to the drive contour 21. Tightening the pressure bolt 12 causes the pressure bolt 12 to act with its base 23 against the upper side of the force distribution element 14.The force distribution element 14 distributes the axial force applied centrally in the center region to the annular end face of the conical bolt 3 facing the pressure bolt 12, which is then pushed into the expansion sleeve 2 in the direction of the conical taper. This movement of the conical bolt 3 relative to the expansion sleeve 2 leads to an expansion of the expansion sleeve 2 in its expansion section 6. This axial movement of the conical bolt 3 when tightening the expansion bolt 1 is shown in FIG. Figure 2 marked by a block arrow.

[0038] The expansion section 6 of the expansion sleeve 2 is designed with regard to its axial extension with respect to the expansion bolt bores of the two assembly parts 25, 26 such that the expansion section 6 engages with an approximately equal section in each expansion bolt bore.

[0039] The expansion bolt 1 clamped with the two assembly parts 25, 26 is in Figure 3shown. This sectional view illustrates that no components of the expansion bolt 1 protrude beyond the surface 28 of the mounting part 25 facing the operating side. The expansion sleeve 2 is matched to the intended depth of the coaxial expansion bolt bores of the mounting parts 25, 26, or vice versa: The expansion bolt bores are adapted to the axial length of the expansion bolt 1. The screw-in depth or the adjustment path of the conical bolt 3 for clamping the expansion bolt 1 is provided such that a defined radial preload is exerted on the expansion bolt bores.

[0040] Figure 4shows the expansion bolt 1 connecting the assembly parts 25, 26 with the force flow shown schematically with block arrows. By expanding the expansion section 6 of the expansion sleeve 2, the radial preload acts against the wall of the expansion bolt bores of the assembly parts 25, 26. The screwing-in movement of the pressure bolt 12 is also shown schematically in this illustration by a block arrow. This is absorbed by the abutment body 13 which is held in the axial direction with a form-fitting connection to the expansion sleeve 2, and to which the pressure bolt 12 is in turn held in the axial direction with a form-fitting connection. Therefore, no additional clamping abutments such as threads or the like are required to tighten the expansion bolt 1. The expansion bolt 1 is therefore an expansion bolt with no external thread.

[0041] The monitoring and control of the clamping process is carried out using the process steps specified in the introduction to the description.

[0042] Given the above-described background that the conical bolt 3 has been pressed into the expansion sleeve 2 in the axial direction to tighten the expansion bolt 1, the expansion bolt 1 can also be loosened again using simple means and then removed from the expansion bolt bores. The loosening process is described below: If the connecting arrangement, comprising the two assembly parts 25, 26 to be connected to one another and the expansion bolt 1 connecting these assembly parts 25, 26, is to be loosened, the pressure bolt 12 is first unscrewed from the abutment body 13. Subsequently, the abutment body 13 is unscrewed from the expansion sleeve 2, whereby the latter can also be carried out together with the pressure bolt 12 located therein.In the next step, the force distribution element 14 is also removed from the expansion sleeve 2, so that the drive contour 11, which in the illustrated embodiment is designed as an internal thread, is accessible from the operating side. A threaded rod 29 is screwed into this drive contour 11 of the conical bolt 3 (see ). Figure 5). The threaded rod 29 has, at its end screwed into the drive contour 11, a pin-like extension with a reduced diameter, with which the threaded rod 29 is clamped to the bottom of the bore providing the drive contour 11. The threaded rod 29 projects beyond the free end of the expansion sleeve 2. A support disk 30 is placed on the section of the threaded rod 29 protruding from the expansion bolt bore of the mounting part 25, and then a nut 31 is screwed onto the threaded rod 29. The nut 31 rests on the upper side of the support disk 30. To guide the threaded rod 29 and to position the support disk 30, the latter has an annular extension 32 engaging in the expansion sleeve 2. By simply screwing the nut 31 onto the threaded rod 29 connected to the conical bolt 3, the conical bolt 3 is pulled out of the expansion sleeve 2, as shown in Figure 6is indicated by a block arrow. Once the conical bolt 3 has been pulled out of the expansion sleeve 2 sufficiently far to relieve the radial preload, the conical bolt 3 and the expansion sleeve 2 can then be pulled out of the coaxially arranged expansion bolt bores of the assembly parts 25, 26.

[0043] The invention is described using exemplary embodiments. Without departing from the scope of the applicable claims, numerous further possibilities for implementing it will become apparent to a person skilled in the art without needing to explain them in the context of these statements. List of reference symbols 1, 1.1 Expansion bolt 31 Mother 2, 2.1 expansion sleeve 32 appendage 3 Conical bolt 4 clamping device 5 second end 6 Expanding section / section 7 slot 8 first end 9 Section 10 Support structure 11 Connection contour / internal thread 12 pressure bolt 13 abutment body 14 Force distribution element 15 External thread section 16 internal thread 17 Stop flange 18 Stop heel 19 Rotary driving contour 20 Through hole 21 Drive contour 22 Threaded section 23 Foot 24 cones 25, 25.1 Assembly part 26, 26.1 Assembly part 27, 27.1, 27.2, 27.3 Stop heel 28 surface 29 threaded rod 30 Support disc

Claims

1. Releasable expanding bolt with - an expanding sleeve (2, 2.1) with a first end (8), a second end (5), a cylindrical outer jacket surface and, on the inside, with an inner cone section tapering towards the second end (5), - a cone bolt (3) with a cone section cooperating with the inner cone section of the expanding sleeve (2, 2.1) for expanding the same as a result of an axial relative movement of the expanding sleeve (2, 2.1) and the cone bolt (3), and - a clamping device (4), connected to the end section providing the first end (8) of the expanding sleeve (2), for adjusting the cone bolt (3) in the axial direction with respect to the expanding sleeve (2, 2.1), characterized in that the clamping device (4) comprises a thrust bolt (12) which is held in a positive-locking manner in the axial direction in the region of the first end section of the expanding sleeve (2, 2.1) and can be adjusted in the axial direction relative to the expanding sleeve (2, 2.1) and has a drive contour (21) at its outer end, the foot (23) of which, lying opposite the drive contour (21), acts on the cone bolt (3) during clamping of the thrust bolt (12) in order to expand the expanding sleeve (2), and in that at least one connecting contour (11) is provided in the end face of the cone bolt (3) facing the clamping device (4) for the positive connection in the axial direction of a connecting part (29) of a release tool for releasing the clamped expanding bolt (1) by pulling the cone bolt (3) out of the expanding sleeve (2).

2. Expanding bolt according to claim 1, characterized in that the pressure bolt is brought into engagement with the expanding sleeve via a thread and is adjustable in the axial direction relative to the latter.

3. Expanding bolt according to claim 1, characterized in that the clamping device (4) comprises an abutment body (13), which is positively connected on the inside to the first end section of the expanding sleeve (2, 2.1) in the axial direction and has a central through-bore (20) equipped with an internal thread, and the pressure bolt (12) meshes with the internal thread of the through-bore (20) of the abutment body (13).

4. Expanding bolt according to claim 3, characterized in that the abutment body (13) is screwed to the expanding sleeve (2, 2.1) and the expanding sleeve (2, 2.1) has an internal thread (16) in its first end section and the abutment body (13) has an external thread (15) complementary thereto.

5. Expanding bolt according to claim 3, characterized in that the abutment body comprises a plurality of components which are connected to one another in a form-fitting manner, wherein one of these components is screwed to the expanding sleeve and another component has a through-bore with an internal thread into which the pressure bolt is screwed.

6. Expanding bolt according to any one of claims 1 to 5, characterized in that a force distribution element (14) for transmitting the clamping force provided via the foot (23) of the pressure bolt (12) to the cone bolt (3) is arranged between the foot (23) of the pressure bolt (12) and the cone bolt (3).

7. Expanding bolt according to claim 6, characterized in that the force distribution element (14) is designed in the manner of a disk, the diameter of which is greater than the diameter of the foot (23) of the thrust bolt (12).

8. Expanding bolt according to claim 7, characterized in that the force transmission element carries an outer circumferential pressure ring on its side facing the cone bolt in the region of its radial termination.

9. Expanding bolt according to any one of claims 1 to 8, characterized in that the force-distributing element (14) carries, on its side pointing towards the cone bolt (3), a pin (24) engaging in the connecting contour (11).

10. Expanding bolt according to any one of claims 1 to 9, characterized in that the connecting contour (11) introduced into the cone bolt (3) is an internal thread.

11. Expanding bolt according to any one of claims 1 to 10, characterized in that the expanding sleeve (2, 2.1) and / or the abutment body (13) have, at a radial distance from the pressure bolt (12), at least one supporting structure (10), which is accessible in the axial direction, for positive engagement and support of the reaction arm of a clamping tool.

12. Expanding bolt according to claim 11, characterized in that a plurality of supporting structures (10) of the same type are provided in the circumferential direction and are arranged at the same angular spacing and at a spacing from one another, and the supporting structures (10) are designed in the manner of a crown closure of a crown nut for the engagement of a sleeve having an engagement contour complementary thereto on the end face as a coaxial reaction arm of a clamping tool.

13. Connection assembly comprising an expanding bolt (1, 1.1) according to any one of claims 3 to 12 and at least two mounting parts (25, 26; 25.1, 26.1) to be connected to one another, characterized in that the mounting parts (25, 26; 25.1, 26.1) to be connected to one another have in each case expanding bolt bores which are coaxial with one another for inserting the expansion bolt (1, 1.1) and in which the expanding bolt (1, 1.1) is inserted and is held clamped therein as a result of the radial expansion of its expanding sleeve (2, 2.1) when the expanding bolt (1, 1.1) is clamped, and that the clamping device (4) ends with its outer side flush with the adjacent surface (28) of the assembly part (25) arranged on the operator side or is lowered relative to this when the expanding bolt (1) is clamped.

14. Connection assembly according to claim 13, characterized in that the depth of insertion of the expanding bolt (1, 1.1) into the mutually coaxial expanding bolt bores of the mounting parts (25, 26; 15.1, 26.1) to be connected to one another is limited by a stop shoulder (27, 27.1, 27.2, 27.3) acting against the expanding sleeve (2, 2.1).

15. A method for producing a connection assembly according to any one of claims 13 or 14, comprising the following steps: - Arranging the mounting parts (25, 26; 25.1, 26.1) to be connected to one another, each having an expanding bolt bore, so that their expanding bolt bores are aligned coaxially with one another, - Inserting the expanding bolt (1, 1.1) preassembled with respect to its components into the expanding bolt bores, and - Clamping the expanding bolt (1, 1.1) by tightening the pressure bolt (12) by means of a motor-driven clamping tool, first torque-controlled up to a pre-tightening torque, in order to cancel out the radial play between the expanding bolt (1, 1.1) and the expanding bolt bores, and then path-controlled by means of an angle measurement, in order to press the cone bolt (3) into the expanding sleeve (2, 2.1) and expand the latter in a defined manner.