Removable expansion bolt, connection arrangement, and method for making such a connection arrangement

Abstract

To provide an expansion bolt that can be used in a limited installation space and can also be clamped by simpler means.SOLUTION: An expansion bolt comprises: an expansion sleeve 2 having a first end, a second end, and a cylindrical outer side and having inside a cone section whose cross-sectional area tapers toward the second end; a cone bolt having a cone section that cooperates with the inner section of the expansion sleeve 2 to expand the expansion sleeve as a result of axial relative movement between the expansion sleeve 2 and the cone bolt 3; and a clamp device connected to an end section that provides the first end of the expansion sleeve 2 for adjusting the cone bolt 3 axially relative to the expansion sleeve 2.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention provides an expansion sleeve having a first end, a second end, and a cylindrical outer side surface and having an internal cone section tapering in cross-sectional area towards the second end; a cone bolt having a cone section that cooperates with an inner section of the expansion sleeve to expand the expansion sleeve as a result of relative axial movement of the expansion sleeve and the cone bolt; a clamping device connected to an end section providing the first end of the expansion sleeve for adjusting the cone bolt axially relative to the expansion sleeve; The present invention relates to a removable expansion bolt having: [Background technology]

[0002] Expansion bolts are used to make positive-fit connections, such as flange connections, especially when high torques or lateral forces need to be transmitted to the flange shaft. One area of ​​use for such expansion bolts is in wind turbines, for example, to make torsionally stiff connections between two shaft flanges in the drive train.

[0003] Such form-fit connections often involve the use of expansion bolts, which engage blind holes. These types of expansion bolts include a bolt, which may have a threaded portion as a fastening means, and which is fastened to an internally threaded hole in a blind hole in a first assembly. To apply the necessary clamping force when clamping the bolt, an anchor acting in the bolt's axial direction is required. The bolt has cone segments, on which an expansion sleeve mounted interacts with a complementary internal cone profile. Therefore, such bolts are also referred to as cone bolts in the following description. The cone segments are tapered to a point by the fastening means of the cone bolt. The taper is therefore directed toward the opening of the blind hole. The expansion sleeve can be expanded by moving it axially relative to the cone bolt. The expansion sleeve is typically slotted. Such an expansion bolt is known from EP 2191150 B1. In this previously known expansion bolt, the expansion sleeve has an external thread on the portion that protrudes from the mounting hole. At the opposite end of the fastening means, designed as a threaded segment, the cone bolt carries a threaded section onto which a clamping nut, typically with an outer tool contour, is screwed to attach a clamping tool. The clamping nut is screwed onto the male threaded section of the expansion sleeve. After fastening the cone bolt in the blind hole of the first assembly using the fastening means, designed as a threaded section, the expansion sleeve is inserted into the assembly hole. Care must be taken to leave a gap between the clamping nut and the outer surface of the second assembly. The clamping nut is then screwed onto the threaded section of the cone bolt until it contacts the expansion sleeve. By further loosening the screw, the expansion sleeve is pressed into the mounting hole, with the cone bolt fastened against the taper of the cone section toward the clamping screw and the internal cone contour of the expansion sleeve. This requires the expansion sleeve to expand until the aforementioned gap closes.Before tightening the clamping nut, a radial preload can be established between the clamping nut and the outside of the second assembly via an expansion sleeve, which is introduced into the walls of the two assemblies to be clamped around the assembly hole. Further tightening of the clamping nut after closing the gap generates the required axial force on the assemblies clamped together.

[0004] Another expansion bolt is known from EP 3658785 B1. In this expansion bolt, the cone section tapers toward the thread on the foot side of the cone bolt, thereby connecting the expansion bolt to the clamp abutment. In this expansion bolt, a radially protruding clamp flange is provided on the expansion sleeve. Between the clamp flange and the surface of the mounting part located on the operating side, a clamping device is clamped via a plurality of circumferentially arranged clamp bolts and simultaneously supported on the surface of the mounting part on the operating side. In this respect, in this expansion bolt, the sleeve is pulled out of the expansion bolt hole of the assembly that accommodates the expansion bolt. An advantage of this expansion bolt is that it can be released by simple means by applying an axially acting release force, which is sometimes required.

[0005] In addition to the above types of expansion bolts, there are also expansion bolts with threads that are not connected to an axial clamping abutment, such as a threaded hole or abutment nut in a mounting part away from the operating side, where the expansion bolt passes through assembly parts to be connected to each other and a threaded bearing nut is screwed into the thread. These expansion bolts are used when it is necessary to specifically absorb lateral forces relative to the axis of the expansion bolt between the assembly parts to be connected to each other. In this expansion bolt, the conical taper of the expansion sleeve and the taper of the conical bolt that interacts with it are directed toward the operating side. The expansion bolt is clamped by applying a clamping force acting on the conical bolt.

[0006] A common feature of the expansion bolts mentioned above is that a clamping tool must be supported on the operating surface of the assembly to clamp it. This means that on the assembly parts to be connected together radially, there must be a corresponding space outside the expansion bolt hole to accommodate the clamping device and attach the clamping tool. This is not always the case.

[0007] Such expansion bolts are usually clamped using hydraulic clamping tools that operate at very high pressures (usually several hundred bar). Oil spurting from possible leaks can cause serious injuries to personnel. From a safety point of view, this is particularly problematic when such expansion bolts are located in confined spaces, such as hollow shafts, and must be clamped there. This is necessary, for example, when connecting the rotor shaft of a wind turbine to the transmission shaft. For this purpose, the operator must insert the clamping tool into the hollow shaft. If there is a leak in the hydraulic system, the operator cannot quickly escape from the danger area to protect himself from injury.

[0008] From US 4135432 A1 and US 2004 / 0136802 A1, clamping bolts are known in which an expansion sleeve is axially fixed in a borehole in a form-locking manner, and which expansion bolt cannot be removed.

[0009] The present invention is therefore based on the above-mentioned prior art and is based on the object of proposing an expansion bolt which can not only be used in limited installation spaces but can also be clamped by simpler means. Summary of the Invention

[0010] The problems associated with expansion bolts are solved according to the invention by an expansion bolt as set out in the preamble of claim 1.

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

[0012] The expansion bolt can be clamped without an axially acting abutment. When the expansion bolt is clamped, a closed force system is established. Therefore, since the expansion bolt is located in an unthreaded hole, it can be clamped, particularly in an unthreaded blind hole, which is particularly advantageous. This is achieved by moving the cone bolt of the expansion bolt to expand the expansion sleeve and clamp the expansion bolt. This movement of the cone bolt occurs axially away from the operating side, and the clamp bolt is supported in a form-fitting manner on the axially acting cone sleeve. Therefore, the expansion bolt does not require an additional clamping abutment, as is the case with conventional expansion bolts. Since the cone bolt is pressed into the expansion sleeve according to the intended orientation of the cone taper, no mounting surface area on the operating side for placing the clamping abutment is required. This explains the very small space required for such an expansion bolt. The expansion bolt itself does not need to occupy any more installation space than is already provided by the expansion bolt hole. This means that the expansion bolt can be designed so that it does not protrude radially beyond the outer diameter of the expansion bolt hole. Because the clamping bolt is centrally positioned relative to the longitudinal axis of the expansion bolt, the required installation space for the clamping tool is also minimized. This is determined solely by the size of the clamping tool used. As a result of the central positioning of the single clamping bolt provided for expanding this expansion bolt, it can be clamped with a relatively small clamping tool, so the expansion bolt can be clamped. Even expansion bolts with larger diameters can be easily clamped using, for example, a pneumatic screwdriver or an electric clamping tool such as a powerful cordless screwdriver.

[0013] If such a clamping tool is provided with a power transmission head that tightens the clamping bolt of the expansion bolt and engages its drive profile, it is advantageous to have a coaxial reaction arm that is rotationally and positively supported on a structure provided on the operating end of the expansion bolt. This support allows the expansion sleeve to remain stationary and simultaneously utilizes only the clamping force of the clamping bolt to effect axial adjustment of the cone bolt within the expansion sleeve. Such reaction arm support is not fundamentally necessary. The expansion bolt can also be clamped without such reaction arm support or using the support of a separate reaction arm. In such cases, the frictional connection between the outer cylindrical side surface of the expansion sleeve and the inner wall of the expansion bolt hole is utilized.

[0014] It is entirely possible to design an expansion sleeve for such an expansion bolt that carries external clamping structures, for example circumferentially arranged clamping ribs that are pressed into the walls of the expansion bolt hole as a result of the expansion sleeve expanding. Axial forces can then be transmitted between the assembly parts in a form-locking manner by the expansion bolt.

[0015] In one embodiment of such an expansion bolt, the clamping bolt is engaged with the expansion sleeve at its first end section, i.e., the operating end section, via a screw thread. This allows the clamping bolt to be positively supported on the expansion sleeve and, at the same time, threadably adjustable axially relative to the expansion sleeve. This configuration is particularly suitable for expansion bolts with smaller diameters.

[0016] According to another embodiment, the clamping bolt is held on the expansion sleeve via an abutment body and is axially adjustable relative to it. The abutment body is axially connected to the inside of the first end section of the expansion sleeve in a form-locking manner. Furthermore, the abutment body has a central through-hole with an internal thread. The clamping bolt passes through this internal thread. Even with this configuration, the force flow is closed when the expansion bolt is clamped. According to a preferred embodiment, the abutment body is screwed onto the expansion sleeve. However, a form-locking axial connection, such as a plug-and-turn connection like a bayonet lock, can also be provided at this point. If a threaded connection is provided between the expansion sleeve and the abutment body, the expansion sleeve has an internal thread on its first end section and the abutment body has a complementary external thread. Again, this embodiment does not require a radial space greater than the diameter of the expansion sleeve.

[0017] The expansion bolt can be realized with an abutment body that is threadedly connected and held in the expansion sleeve if the threaded connection is equipped with a stop that limits the screw-in depth of the abutment body. According to one embodiment, for this purpose, an outwardly protruding circumferential stop flange is provided on the abutment body, which acts against the end face of the first end of the expansion sleeve. According to another embodiment, a stop is provided within the expansion sleeve, against which the abutment body acts. In such an embodiment, the stop shoulder located within the expansion sleeve can be configured to be at a depth such that, when the expansion bolt is clamped, the abutment body, through which the clamping bolt passes, is completely submerged entirely within the first end section of the expansion sleeve, thereby not protruding beyond the first end of the expansion sleeve. An advantage of such an embodiment is that, for example, if the two assembly parts are flanges for connecting two shaft parts, the fastener will not protrude above the flange. In this case, the first end section of the expansion sleeve can also have a support structure for a torque-lock 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. The support structure for the torque trench connection of the reaction arm is then provided on the abutment body instead of the cone sleeve. In the latter embodiment, the thread directions between the internal thread of the abutment body and its external thread are preferably opposite to each other, so that there is no risk of the threaded connection between the abutment body and the expansion sleeve loosening when the clamping bolt is clamped.

[0019] The expansion bolt embodiment, in which the clamping bolt is connected to the expansion sleeve via the abutment body, is particularly suitable for expansion bolts with large diameters. In such cases, it is expedient if a pressure transmission element is arranged between the foot of the clamping bolt, i.e., the end of the clamping bolt opposite the drive profile, and the cone bolt. Such a pressure transmission element transmits the clamping force of the clamping bolt, which is typically directed only to the central region due to the small diameter of the clamping bolt compared to the diameter of the cone bolt, to the available surface of the end of the cone bolt facing the clamping bolt. It has proven useful if the clamping force for axially adjusting the cone bolt for clamping the expansion bolt is applied circumferentially to the outer edge region of the cone bolt, rather than only to a limited central region. When such force transmission is provided from the clamping bolt to the cone bolt, the force transmission element can be formed in the shape of a disk and can carry a circumferential thrust collar on its radial end region facing the cone bolt.

[0020] The expansion bolt according to the present invention can be easily removed by simple means. This is because the cone bolt is axially pressed into the expansion sleeve to apply tension to the expansion bolt. Therefore, the expansion bolt can be easily removed by withdrawing the cone bolt from the expansion sleeve. Typically, the expansion sleeve itself or the outer surface of the abutment body forms the abutment. To withdraw the cone bolt from its expanded position in the expansion sleeve, where it is secured, a procedure is provided in which an inverted connecting profile is introduced as a connecting profile in the center of the end face of the cone bolt facing the clamping bolt, to which the connecting part of the release tool is axially connected in a form-locking manner. Such a connecting profile can be, for example, an internal thread or a component of a bayonet lock. This connecting profile is made accessible for removing the expansion bolt. For this purpose, depending on the embodiment of the expansion bolt, it is only necessary to loosen the clamping bolt or unscrew the abutment body together with the clamping bolt from the threaded sleeve, thereby removing the force transmission element, if any. The connecting profile is then axially accessible from the operating side.

[0021] In embodiments in which the operating side of the expansion bolt has at least one support structure for supporting the torque of the reaction arm of the clamping tool, it is expedient if there are several support structures arranged concentrically with the clamping bolt and at the same angular distance from each other, and the reaction arm engaging therewith is provided to be designed coaxially and have a corresponding complementary engagement contour.

[0022] In a connection arrangement in which at least two assembly parts are connected to one another by such an expansion bolt, it is expedient if a stop shoulder is provided in the expansion bolt hole of the assembly part to determine the insertion depth of the expansion bolt, which stop shoulder acts against a shoulder on the free front face or outer diameter of the expansion sleeve.

[0023] A connection arrangement comprising at least two assembly parts to be connected to one another and at least one expansion bolt of the type described above is made as follows.

[0024] First, the assemblies to be connected together are positioned relative to each other so that their expanded bolt holes are aligned with each other, i.e., coaxially aligned.

[0025] The expansion bolt to be inserted is preassembled, meaning that the cone bolt is inserted into the expansion sleeve and, if necessary, slightly clamped beforehand, secured by a clamping device. This means that the clamping bolt is also screwed into the expansion sleeve, optionally with the abutment body interposed. This preassembled expansion bolt is inserted into the coaxial expansion bolt hole from one side—the operating side of the connecting structure—up to a stop shoulder preferably located within the expansion bolt hole. This acts against a stop shoulder of the expansion sleeve facing 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 hole such that the cone covers the two assembly parts in the desired proportion, depending on the expansion bolt design. Based on the expansion bolt concept, the expansion sleeve can be inserted into the expansion bolt hole so that it is flush with the adjacent surface of the assembly part facing the operating side. This is easily possible with the described expansion bolt embodiment, since the expansion sleeve remains stationary within the expansion bolt hole when the expansion bolt is clamped.

[0026] The expansion bolt is then clamped. For this purpose, a motor-driven clamping tool, typically an electric, particularly battery-powered clamping tool such as a cordless screwdriver with a receptacle corresponding to the drive profile of the clamping bolt, is typically placed on the clamping bolt. Such a clamping tool preferably has a reaction arm, through which the reaction torque generated in response to the tightening torque is supported on the expansion sleeve. Alternatively, the reaction torque can be supported by one or more components positively connected to the expansion sleeve. The screwing process is preferably performed in a path-controlled manner, i.e., a certain amount of screwing must be performed to move the cone bolt within the expansion sleeve through a defined adjustment path until the expansion bolt is clamped as desired. When using an electric clamping tool such as a cordless screwdriver, path detection is performed via the existing motor control, and the change in the rotation angle of the rotor or output shaft is recorded. The path-controlled process of clamping the expansion bolt with a predetermined radial preload is initiated when a specific tightening torque is applied to the expansion bolt in advance to eliminate any necessary play when inserting the expansion bolt into the expansion bore. Ultimately, the adjustment path should only affect the control of the radial pressure introduced into the wall of the expansion bolt hole. The advantage of such path control is that friction within the expansion bolt, which affects the tightening torque management of the expansion bolt, does not adversely affect the radial pressure introduced.

[0027] The connection structure can also be easily removed again. To do this, the first step is to unscrew the clamping bolt. The cone bolt is then pulled out by applying a traction force to it. This can be done, for example, by a threaded rod screwed into the expansion sleeve. Preferably, the expansion sleeve is provided with a support for applying the traction force to the threaded rod, for example, by means of a nut or a suitable tool. [Brief explanation of the drawings]

[0028] The invention is explained below using exemplary embodiments with reference to the accompanying drawings. [Figure 1] 1 is a perspective view of an expansion bolt according to the present invention, shown in an exploded view; [Figure 2] FIG. 2 is a cross-sectional view of the connection configuration using the expansion bolt of FIG. 1, showing the expansion bolt in an unclamped state. [Figure 3] Figure 2 connection configuration using clamped expansion bolts. [Figure 4] FIG. 4 is a view corresponding to FIG. 3, showing the force flow when clamping the expansion bolt. [Figure 5] 5 is a cross-sectional view of the connection arrangement of FIGS. 2 to 4 with a release tool for removing the expansion bolt before actuation of the release tool. FIG. [Figure 6] Figure 5 Connection configuration with expansion bolt released. [Figure 7] 3 is a cross-sectional view of a connection configuration in which the expansion bolt is disposed at a different axial position relative to the parting line between the assembly parts compared to FIG. 2. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0029] The expansion bolt 1 includes an expansion sleeve 2, a cone bolt 3, and a clamping device 4. The expansion sleeve of the illustrated exemplary embodiment 2 have cylindrical outer sides and have two types of expansion ofThe section 6 is divided into two parts. The section 6, which surrounds the second end 5 of the expansion sleeve, has a conical surface tapering inward toward the second end 5 (as can be seen in cross section in Figures 2 to 6). This section 6 is provided with slots. Such slots 7 are shown in Figure 1. In the illustrated exemplary embodiment, the section 6 has two slots 7 diametrically opposed to each other. The slots 7 serve the purpose of allowing the section 6 to expand and thus widen. Therefore, this section 6 can also be considered an expansion section. Section 6 is followed by section 9, which carries the first end 8 of the expansion sleeve 2 and is also referred to as the first end section in the context of these descriptions. The inner wall structure of the first end section 9 is described below in connection with Figure 2.

[0030] The first end 8 of the expansion sleeve 2 is provided with a number of support structures 10 arranged at equal angular distances from one another, allowing a form-fitting connection to the corresponding opposing contours of the reaction arm of the clamping tool. In a preferred embodiment, these support structures are achieved according to the type of star washer of the star nut.

[0031] The cone bolt 3 of the illustrated exemplary embodiment tapers conically along its entire length, along with its outer side. The cone section therefore extends over the entire axial extent of the cone bolt 3. The taper angle of the cone bolt 3 and the taper angle of the inner wall of the expansion section 6 of the expansion sleeve 2 are the same. At least one thread 11 is inserted into the cone bolt 3 for attaching a release device thereto. The thread 11 is shown as an internal thread.

[0032] A clamping device 4 is used to clamp the expansion bolt 1. In the illustrated exemplary embodiment, it comprises three components: a clamping bolt 12, an abutment body 13, and a force transmission element 14. The abutment body 13 is designed to be inserted into the first end section 6 of the expansion sleeve 2 and axially clamped by the expansion sleeve 2. For this purpose, the abutment body 13 has an external thread 15 at its first end section 6, which cooperates with a complementary internal thread 16 of the expansion sleeve 2 (see FIG. 2 ). When the external thread 15 of the abutment body 13 is threaded into the internal thread 16 of the expansion sleeve 2, the abutment body 13 is axially connected to and held by the expansion sleeve 2 in a form-locking manner. The abutment body 13 also has a stop flange 17 located on the external thread 15, which protrudes radially beyond the external thread section 15. The stop flange 17 serves to limit the 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 a stop flange 17 of the abutment body 13 acts (see FIG. 2). For screwing in, and in particular for fixing the abutment body 13 on the expansion sleeve 2, the former has a rotation drive contour 19 at its upper part, which is described as hexagonal in the exemplary embodiment shown. The abutment body 13 has a central through-hole 20, which is provided with an internal thread.

[0033] The clamping bolt 12, which clamps the expansion bolt 1, has at one end a driving profile 21, which is also depicted as hexagonal in the illustrated exemplary embodiment. A threaded portion 22 borders the driving profile 21 and has an external thread complementary to the internal thread of the abutment body 13. The clamping bolt 12 therefore mates with its threaded portion 22 and the internal thread of the through hole 20.

[0034] The clamping bolt 12 is supported on the force transmission element 14 with its foot 23 opposite the drive profile 21. The force transmission element 14 is designed in disk fashion, i.e. with a diameter that allows it to be inserted into the first end section 6 of the expansion sleeve 2 with the necessary radial play. The force transmission element 14 in the illustrated embodiment has a stud 24 formed on its side opposite the clamping bolt 12, which engages in the drive profile 11 of the cone bolt 3.

[0035] The assembled, and therefore pre-assembled, expansion bolt 1 is shown in FIG. 2 and is inserted into the coaxially arranged expansion bolt holes of two assembly parts 25, 26 and connected to each other. The expansion bolt 1 is pre-assembled by inserting the cone bolt 3 into the expansion sleeve 2 so that the two interacting cone surfaces abut against each other. The force transmission element 14 is then inserted into the expansion sleeve 2. The abutment body is then 13 The abutment body 13 can be clamped by its stop flange 17 against the stop shoulder 18 of the expansion sleeve 2, regardless of whether the clamping bolt 12 is threaded or not, until its external thread 15 is threaded into the internal thread 16 of the expansion sleeve 2, i.e., until the stop flange 17 of the abutment body 13 rests on the stop shoulder 18 of the expansion sleeve. In the illustrated embodiment, the interacting stop surfaces 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 sleeve surfaces in the longitudinal direction provided in the illustrated exemplary embodiment can also be designed differently. For example, alignment of the interacting stop surfaces at 90° relative to the longitudinal axis or other angles are also possible. If the clamping bolt 12 is not installed together with the abutment body 13, finally, the threaded section 22 of the clamping bolt 12 is screwed into the through hole 20 of the internally threaded abutment body 13. In this respect, the expansion bolt 1 including the clamping device 4 can be treated as a single unit. None of the components of the expansion bolt 1 protrude beyond the outer diameter of the cylindrical side of the expansion sleeve 2 .

[0036] The expansion bolt hole of assembly 26 has a stop shoulder 27, which reduces the diameter of the expansion bolt hole, and this stop shoulder 27 acts against the free front face of expansion sleeve 2, which provides second end 5, to position expansion bolt 1 relative to the parting line between assemblies 25 and 26.

[0037] In another embodiment, both the hole in the first assembly and the expansion sleeve in the region of the first end section are designed with a larger diameter than the hole in the second assembly, which creates an axial stop shoulder between the expansion sleeve 2 and the first assembly, thereby positioning the expansion bolt relative to the parting line.

[0038] In another alternative embodiment, both the hole in the first assembly and the expansion sleeve up to the parting line are designed with a larger diameter than the hole in the second assembly, thereby forming an axial stop shoulder between the expansion sleeve and the second assembly, which positions the expansion bolt relative to the parting line.

[0039] FIG. 7 shows an enlarged view of the two aforementioned alternatives for supporting the expansion sleeve 2.1 in the expansion bolt hole. The expansion sleeve 2.1 has a stop shoulder at the free end of its first section. This stop is designated 27.1 in FIG. 7. A second stop shoulder 27.2 is located in the expansion bolt hole made in the assembly 25.1. A third stop shoulder 27.3 is located in the joint area between the two assembly parts 25.1 and 26.1. This illustration serves to illustrate the various possible ways of forming the stop shoulders that limit the insertion movement of the expansion sleeve 2.1 into the expansion bolt hole. Typically, only one stop shoulder is provided.

[0040] To clamp the expansion bolt 1, a suitable clamping tool is used, which is placed on the drive profile 21 of the clamping bolt 12. A cordless screwdriver is preferably used as the clamping tool. In addition to the tool, which can be placed on the drive profile 21 of the clamping bolt 12, this clamping tool also has an annular reaction arm that surrounds the actual clamping tool as a sleeve. Its free end face is designed to be complementary to the structure 10 of the first end 8 of the expansion sleeve 2. At this point, a positive engagement is established between the reaction arm of the clamping tool and the expansion sleeve 2. When a tool connected to the drive profile 21 is clamped, the reaction arm does not rotate. When the clamping bolt 12 is clamped, the clamping bolt 12 acts with its foot 23 against the upper surface of the force transmission element 14. The force transmission element 14 transmits the axial force applied to the center of the intermediate region to the annular end face of the cone bolt 3 facing the clamping bolt 12, which is inserted into the expansion sleeve 2 in the direction of the cone taper. This movement of the cone bolt 3 relative to the expansion sleeve 2 expands the expansion section 6 of the expansion sleeve 2. This axial movement of the cone bolt 3 when clamping the expansion bolt 1 is shown by the block arrow in FIG.

[0041] The expansion section 6 of the expansion sleeve 2 is so carried out that, with respect to its axial extent relative to the expansion bolt holes of the two assembly parts 25, 26, the expansion section 6 engages in approximately equal parts of each expansion bolt hole.

[0042] The expansion bolt 1 clamped between two assembly parts 25, 26 is shown in Figure 3. This cross-sectional view shows that no components of the expansion bolt 1 protrude above the surface 28 of the assembly part 25 facing the operating side. The expansion sleeve 2 is adapted to the intended depth of the coaxial expansion bolt holes of the assembly parts 25, 26, or vice versa. The expansion bolt holes are adapted to the axial length of the expansion bolt 1. The threading depth or adjustment path of the cone bolt 3 is provided so that a defined radial preload is applied to the expansion bolt holes in order to clamp the expansion bolt 1.

[0043] FIG. 4 shows the expansion bolt 1, which connects the assemblies 25 and 26, diagrammatically with block arrows, through which the force flows. The expansion of the expansion sleeve 2's expansion section 6 exerts a radial preload against the walls of the expansion bolt holes in the assemblies 25 and 26. The screwing action of the clamping bolt 12 is also shown diagrammatically with block arrows in this figure. This is captured by the abutment body 13, which is axially and form-lockingly held in the expansion sleeve 2, on which the clamping bolt 12 is axially and form-lockingly held. No additional clamping abutment, such as a screw thread, is required to clamp the expansion bolt 1. Therefore, the expansion bolt 1 is an expansion bolt without external threads.

[0044] Monitoring or control of the clamping process is carried out using the procedural steps specified in the introduction to the description.

[0045] Against the background described above, where the cone bolt 3 is axially pressed into the expansion sleeve 2 to clamp the expansion bolt 1, the expansion bolt 1 can be loosened again and removed from the expansion bolt hole using simple means. The release process is as follows:

[0046] To release the connection arrangement, which includes two interconnected components 25, 26 and the expansion bolt 1 connecting these components 25, 26, the clamping bolt 12 is first screwed out of the abutment body 13. The abutment body 13 is then unscrewed and removed from the expansion sleeve 2, possibly together with the clamping bolt 12 located inside. In a next step, the force transmission element 14 is also removed from the expansion sleeve 2, allowing access from the operating side to the drive profile 11, which in the illustrated exemplary embodiment is designed as an internal thread. A threaded rod 29 is screwed into this drive profile 11 of the cone bolt 3 (see FIG. 5 ). At its end threaded into the drive profile 11, the threaded rod 29 carries a stud-like extension with a reduced diameter, which clamps the threaded rod 29 against the bottom of the hole that provides the drive profile 11. The threaded rod 29 protrudes beyond the free end of the expansion sleeve 2. A support disk 30 is placed on the portion of the threaded rod 29 that protrudes through the enlarged bolt hole in the assembly 25, and then a nut 31 is threaded onto the threaded rod 29.

[0047] The nut 31 is supported on the surface of the support disk 30. To guide the threaded rod 29 and position the support disk 30, the threaded rod 29 has an annular extension 32 that engages with the expansion sleeve 2. Simply threading the nut 31 onto the threaded rod 29 connected to the cone bolt 3 causes the cone bolt 3 to be withdrawn from the expansion sleeve 2, as shown by the block arrow in Figure 6. Once the cone bolt 3 has been sufficiently withdrawn from the expansion sleeve 2 and the radial preload has been reduced, the cone bolt 3 and the expansion sleeve 2 can then be withdrawn from the expansion bolt holes of the coaxially arranged assemblies 25 and 26.

[0048] The present invention is described using exemplary embodiments, and there are many other possibilities that those skilled in the art can implement without departing from the scope of the applicable claims and without being described in the context of these descriptions. TIFF0007827758000001.tif195170

Claims

1. A removable expansion bolt, an expansion sleeve (2, 2.1) having a first end (8), a second end (5) and a cylindrical outer side surface and having an inner cone section tapering in cross section towards said second end (5); - a cone bolt (3) having a cone section that cooperates with an inner section of the expansion sleeve (2, 2.1) to expand the expansion sleeve as a result of a relative axial movement of said expansion sleeve and the cone bolt (3); a clamping device (4) connected to the end section providing the first end (8) of the expansion sleeve (2) for adjusting the cone bolt (3) axially relative to the expansion sleeve (2, 2.1); and 1. The method of claim 1, wherein the clamping device (4) comprises a clamping bolt (12) which is held in an axially form-locking manner in the region of the first end section of the expansion sleeve (2, 2.1) and which is axially adjustable relative to the expansion sleeve (2, 2.1), the clamping bolt (12) having a drive contour (21) at its outer end, a foot (23) of the clamping bolt (12) opposite the drive contour (21) acting on the cone bolt (3) when clamping the clamping bolt (12) to expand the expansion sleeve (2), and an end face of the cone bolt (3) facing the clamping device (4) is provided with at least one connection contour (11) for axially form-lockingly connecting a connection part (29) of a release tool for releasing the clamped expansion bolt (1) by withdrawing the cone bolt (3) from the expansion sleeve (2).

2. 2. The expansion bolt of claim 1, wherein the clamp bolt engages the expansion sleeve via a thread and is axially adjustable relative to the expansion sleeve.

3. 2. The expansion bolt according to claim 1, characterized in that the clamping device (4) comprises an abutment body (13) axially connected to the inside of the first end section of the expansion sleeve (2, 2.1) in a form-fitting manner, the abutment body (13) having a central, female-threaded through-hole (20), and the clamping bolt (12) engages with the female thread of the through-hole (20) of the abutment body (13).

4. 4. The expansion bolt according to claim 3, wherein the abutment body (13) is screwed onto the expansion sleeve (2, 2.1), the expansion sleeve (2, 2.1) having an internal thread (16) at the first end section thereof and the abutment body (13) having a complementary external thread.

5. 2. The expansion bolt according to claim 1, characterized in that a force transmission element (14) is arranged between the foot (23) of the clamping bolt (12) and the cone bolt (3) for transmitting the clamping force provided via the foot (23) of the clamping bolt (12) to the cone bolt (3).

6. 6. Expansion bolt according to claim 5, characterized in that the force transmission element (14) is designed in the shape of a disk, the diameter of which is greater than the diameter of the foot (23) of the clamping bolt (12).

7. 7. An expansion bolt according to claim 6, characterized in that the force transmission element carries an outer circumferential thrust collar in the region of its radial connection on the side facing the cone bolt.

8. 6. Expansion bolt according to claim 5, characterized in that the force transmission element (14) carries, on the side facing the cone bolt (3), a pin (24) which engages in the connecting contour (11).

9. 2. Expansion bolt according to claim 1, characterized in that the connection contour (11) introduced into the cone bolt (3) is an internal thread.

10. 4. The expansion bolt according to claim 3, characterized in that the expansion sleeve (2, 2.1) and / or the abutment body (13) at a radial distance to the clamping bolt (12) have at least one support structure (10) accessible in the axial direction for form-fitting engagement and support of a reaction arm of a clamping tool.

11. 11. The expansion bolt according to claim 10, characterized in that it comprises a plurality of similar support structures (10) arranged circumferentially at equal angular distances from one another, said support structures (10) being realized in the form of star washers of star nuts for engaging with a sleeve having a complementary engagement contour on its front surface as a coaxial reaction arm of a clamping tool.

12. 12. A connection structure comprising an expansion bolt (1, 1.1) according to any one of claims 3 to 11 and at least two assembly parts (25, 26; 25.1, 26.1) to be connected to each other, wherein the assembly parts (25, 26; 25.1, 26.1) to be connected to each other have coaxial expansion bolt holes for the insertion of the expansion bolt (1, 1.1), wherein the expansion bolt (1, 1.1) is inserted into the expansion bolt hole and, when clamped, the expansion bolt (1, 1.1) is maintained in a clamped state as a result of the radial expansion of its expansion sleeve (2, 2.1) within the expansion bolt hole, and wherein, when the expansion bolt (1, 1.1) is clamped, the outer side of the clamping device (4) is flush with or lower than the adjacent surface (28) of the assembly part (25) located on the operating side.

13. 13. A connection structure according to claim 12, wherein the insertion depth of the expansion bolt (1, 1.1) into the coaxial expansion bolt holes of the assembly parts (25, 26; 15.1, 26.1) to be connected to each other is limited by stop shoulders (27, 27.1, 27.2, 27.3) acting against the expansion sleeve (2, 2.1).

14. 13. A method for making the connection structure of claim 12, comprising: - positioning the components (25, 26; 25.1, 26.1) that are to be connected to one another and each have an expanded bolt hole so that their expanded bolt holes are oriented coaxially with one another; - inserting said expansion bolt (1, 1.1) pre-assembled with respect to its components into said expansion bolt hole; - clamping the expansion bolt (1, 1.1) by first tightening the clamping bolt (12) in a torque-controlled manner up to a pre-tightening torque using a motor-driven clamping tool in order to eliminate any radial play between the expansion bolt (1, 1.1) and the expansion bolt hole, and then pressing the cone bolt (3) into the expansion sleeve (2, 2.1) in a path-controlled manner using angle measurement, thereby expanding the expansion sleeve (2, 2.1) in a defined manner; A method comprising:

Images