EP3205454B1 - Assembly tool, its use and a method of securing a threaded insert - Google Patents

Description

The invention relates to an assembly tool for threaded inserts, the use of such an assembly tool with a threaded insert adapted to it, and a method for fastening a threaded insert in a workpiece.

Threaded inserts, which can be designed as a threaded bushing or as a thread armouring, are used in workpieces with lower mechanical strength, e.g. in components made of aluminum or gray cast iron, in order to be able to apply comparatively higher loads via the thread. Such thread inserts are also suitable as repair solutions for damaged threads.

Usually, threaded inserts are components that have an external thread with which they are screwed into a possibly damaged thread of a component. The threaded inserts then additionally have an internal thread or a pin with an external thread for connection to another component. In order to securely fix thread inserts in the possibly damaged thread or in a possibly softer material, wedges or pins are driven into the thread insert and / or the workpiece receiving the thread insert. In particular, this prevents the threaded insert from twisting in this workpiece.

So far it has been customary to first screw thread inserts one or two turns into a workpiece by hand. The wedges or pins are then inserted into grooves or holes in a tool and brought into engagement with the threaded insert in such a way that the threaded insert can be rotated through a rotary movement of the tool can be screwed further into the workpiece by means of the wedges or pins. As soon as the wedges or pins meet a phase of hole preparation in the workpiece, the tool is removed and / or the wedges or pins are struck, in particular if the wedges or pins are guided in holes in the workpiece. In a subsequent step, the tool is turned around or displaced so that the wedges or pins can be driven into the tool by striking the tool until the tool hits the workpiece surface. To guide the tool relative to the threaded insert, a cylindrical pin can be inserted into the internal thread of the threaded insert.

In the DE 20 2015 106 393 U an assembly tool for threaded inserts is proposed, which has a bolt which is at least partially provided with a thread, and an impact sleeve, the bolt being guided in the impact sleeve in a rotationally fixed and axially displaceable manner. The bolt (threaded pin) is received in the impact sleeve in such a way that the bolt can dip into the impact sleeve or protrude from the impact sleeve without, however, allowing any significant rotation of the bolt relative to the impact sleeve. This assembly tool is superior to conventional tools in terms of safety and ergonomics. However, due to the sequential steps of screwing in the threaded insert and driving in the pins or wedges, this tool is more suitable for manual assembly and for small series.

From the U.S. 5,617,623 there is known a threaded insert assembly tool comprising a spindle, a sleeve threadedly engaged with the spindle, and locking means for releasably inhibiting rotation of the spindle relative to the sleeve. An external thread of the spindle protrudes from the sleeve

From the U.S. 3,245,137 another assembly tool for threaded inserts is known.

The object of the invention is to provide an assembly tool for inserting a threaded insert into a workpiece, which is also suitable for assembly in large series.

According to the invention, this object is achieved with an assembly tool according to claim 1.

An assembly tool according to the invention has a spindle which is provided at least in sections with a first external thread and at least in sections with a second thread, a sleeve which has a thread engaging with the second thread, and locking means for releasably inhibiting rotation of the spindle relative to it the sleeve on. In this case, the length of the spindle and the length of the sleeve are preferably adapted to one another in such a way that the first external thread at least partially protrudes from the sleeve. The invention is based on the idea of bringing about the screwing of the threaded insert into a workpiece and the subsequent driving in of the pins or wedges of the threaded insert by rotating the assembly tool. This makes it possible to carry out the assembly steps that were previously carried out separately from one another, namely screwing in the insert and driving in the pins or wedges, by a preferably continuous rotation of the assembly tool. As a result, the assembly can be carried out using a cordless screwdriver or the like, without having to use an additional tool, such as the previously required hammer. In large-scale production in particular, dispensing with a tool change saves a great deal of time and thus increases efficiency. Automation of the assembly of a threaded insert is also possible. Another advantage is that the pins or wedges are not driven in suddenly, so that damage to the pins or wedges can be largely ruled out.

For this purpose, it is provided according to the invention that the spindle and the sleeve can be rotated together in a first step in the assembly of the threaded insert. For this purpose locking means are provided which make relative rotation between the spindle and the sleeve at least so difficult that with the comparatively low torque required to screw the threaded insert into the workpiece, there is no relative movement between the sleeve and spindle occurs. If, on the other hand, a higher torque required for driving in the pins or wedges is applied, a relative movement between the sleeve and the spindle is permitted, whereby the relative axial movement component caused by the thread engagement between the sleeve and the spindle is used to drive in the pins or wedges .

The locking means required to switch between the two operating modes of the assembly tool, namely on the one hand the common rotary movement of the sleeve and spindle for screwing in the insert and on the other hand the relative rotary movement of the sleeve and spindle for driving in the pins or wedges, can either be designed in such a way that the relative rotary movement between sleeve and spindle, e.g. in the manner of a ratchet or ratchet or by means of a lock, is completely blocked, or alternatively is inhibited to the extent that at least with the comparatively low torque required to screw the threaded insert into the workpiece, a relative rotation between the sleeve and the spindle is inhibited or prevented. For this last-mentioned alternative, a slip clutch can also be used between the sleeve and the spindle. However, it is preferred if this is achieved through increased friction between the spindle and the sleeve, i.e. without additional components. To achieve this, the fit between the sleeve and the spindle can be selected accordingly and / or the coefficients of friction of the sleeve and / or the spindle can be selected accordingly. The locking means can thus also be formed by the areas of the spindle and the sleeve itself which are in contact with one another.

In any case, the spindle has a thread on two sections, namely on the one hand the first external thread for connection to the threaded insert and on the other hand a further thread which is in engagement with the sleeve. The second thread is preferably also an external thread which engages in an internal thread of the sleeve. The two threads can be considered from each other separate threaded sections may be formed. Alternatively, a continuous thread can be provided on the spindle, which forms both thread sections. Overlapping thread sections can also be provided on the spindle. Both threaded sections preferably have the same direction of rotation. The thread sections can have the same or different pitches.

According to a preferred embodiment of the invention, the locking means have a stop on the spindle and a counter-stop on the sleeve, which releasably block rotation of the spindle relative to the sleeve when the stop rests against the counter-stop. This can be achieved, for example, in that the sleeve, which is in thread engagement with the spindle, jams with one another when the stop of the spindle contacts the counter-stop of the sleeve, whereby this clamping occurs when a larger torque is applied, as is the case for driving in the wedges or the sleeve. Pins is required, releases automatically.

It is preferred that the sleeve, which rotates both during the screwing of the threaded insert into the workpiece and during the driving of the pins or wedges, does not bear directly against the non-co-rotating pins or wedges in order to prevent damage from this relative rotation avoid. For this purpose, the side of the sleeve facing the insert can be provided as a slide bearing with a friction-reducing coating or can be designed with a correspondingly low-friction material pairing. A pressure piece which is arranged radially outside the spindle and has an end wall on the side facing away from the sleeve is preferably mounted on or in the sleeve. With this end wall, the pins or wedges can be driven in when the sleeve moves together with the pressure piece relative to the spindle. In order not to hinder the screwing of the spindle into the threaded insert, the length of the pressure piece, the length of the spindle and the length of the sleeve are important preferably adapted to one another in such a way that the first external thread of the spindle protrudes at least partially from the sleeve and from the pressure piece. Preferably, the pressure piece is freely rotatable relative to the sleeve and is not axially displaceable relative to the sleeve on or in the sleeve. This can be done, for example, using a needle or ball bearing and possibly a locking ring.

In order to automatically switch between the two operating modes of the assembly tool, namely screwing in the insert by means of joint rotation of the sleeve and spindle and driving in the pins or wedges by rotating the sleeve relative to the spindle, the spindle is rotatably fixed with at least one of these Coupled in sections surrounding the spacer ring, wherein the spacer ring for driving in the pins or wedges is axially movable together with the spindle relative to the sleeve. The spacer ring is moved towards the workpiece together with the other components of the assembly tool and together with the threaded insert while the threaded insert is being screwed into the workpiece. As soon as the spacer ring hits the workpiece surface with its end face facing away from the sleeve, this increases the torque required to rotate the assembly tool. This increase in torque causes the locking means between the sleeve and the spindle to loosen, ie, for example, the frictional forces between the sleeve and the spindle being exceeded, as a result of which, as the sleeve continues to rotate, it is rotated relative to the spindle which is fixed together with the spacer ring. Due to the thread engagement, this causes the required relative axial movement between the spindle and the sleeve or the pressure piece in order to move the pins or wedges relative to the threaded insert. The spacer ring is preferably also axially movable relative to the pressure piece. For this purpose, the spacer ring can be secured in the spindle by means of a pin, elongated holes in which the pin is guided are provided in the pressure piece.

The use of the spacer ring allows the screw-in depth of the threaded insert in the workpiece to be determined very precisely, since the screwing-in of the threaded insert is canceled when the spacer ring hits the workpiece surface (end of the first operating mode) and the threaded insert is subsequently driven in by driving the wedges or pins into its position is fixed relative to the workpiece. This makes it possible to mount a large number of threaded inserts with high precision at a defined screw-in depth in the workpiece.

If different screw-in depths are to be implemented, the spacer ring can be designed to be exchangeable, with different screw-in depths being able to be represented with different dimensions of the spacer ring. As an alternative to this, it is also possible to make the spacer ring adjustable. For this purpose, the spacer ring can be designed in several parts and, for example, have an external thread which engages with the internal thread of an adjusting ring that at least partially surrounds the spindle. The setting ring can, if necessary, be fixed in its position with a lock nut, which is also in engagement with the external thread of the spacer ring. In this case, the position of the setting ring relative to the spacer ring and thus to the spindle defines the screw-in depth of the threaded insert or the switching between the operating modes of the assembly tool. For a smaller screw-in depth of the threaded insert, the setting ring must be advanced further relative to the spindle in the screwing direction of the threaded insert, so that the screwing-in process is terminated earlier, whereas the setting ring must be withdrawn relative to the spindle if a greater screw-in depth is to be achieved.

In a particularly preferred embodiment of the assembly tool, the sleeve can have a first cylindrical section in which the as Internal thread formed thread is provided, and a second cylindrical section which is spaced from the first section by a radially inwardly protruding web or flange, and in which a flange section of the pressure piece is rotatably mounted and secured against axial movement, for example by means of a locking ring. The spindle can have a shaft, at one end of which the first external thread is provided and at the opposite second end the second thread designed as an external thread is provided, wherein the second end can have an enlarged diameter compared to the shaft. The pressure piece can, for example, encompass the shaft of the spindle and have two elongated holes in which the spacer ring is guided in a rotationally fixed and axially movable manner by means of a pin. The sleeve and optionally also the spindle are preferably equipped with engagement means for a torque-transmitting tool. It is further preferred if the end wall is provided with a bevel on the side of the pressure piece facing away from the sleeve, so that the pressure piece can be adapted to the geometry of the opening in the workpiece. Alternatively or additionally, a shoulder can also be provided on the end wall of the pressure piece.

Another aspect of the present invention relates to the connection of an assembly tool of the type mentioned above for fastening a threaded insert adapted to the assembly tool. The threaded insert is preferably designed as a sleeve with an external thread and an internal thread, with at least one longitudinal groove in which a wedge or pin is received in the outer surface of the threaded insert. The internal thread of the threaded insert is adapted to the first external thread of the spindle of the assembly tool so that they can be screwed into one another. In addition, the radial position of the at least one pin or wedge is preferably adapted to the radial position of the end wall of the pressure piece of the assembly tool, so that the pressure piece can drive in the at least one pin or wedge.

Another aspect of the invention relates to a method for fastening a threaded insert in an opening of a workpiece. According to the method, an assembly tool of the type mentioned above is first provided, as well as a threaded insert adapted to the assembly tool. The threaded insert is designed, for example, as a sleeve with an external thread and an internal thread, with at least one longitudinal groove being formed in the outer surface of the threaded insert, in which a pin or wedge is received in such a way that the pin or wedge is axially Direction does not extend completely along the external thread of the threaded insert. In other words, the pin or wedge does not initially block the screwing of the external thread of the threaded insert into the workpiece, but rather projects beyond the sleeve-like base body of the insert on the side facing away from the workpiece.

According to the method according to the invention, the threaded insert is then screwed onto the first external thread of the spindle, the rotation of the spindle relative to the sleeve preferably already being inhibited or blocked for this purpose. Subsequently, the threaded insert is screwed into the opening of the workpiece by rotating the sleeve together with the spindle until the spacer ring or a possibly provided setting ring hits the workpiece with its end face facing away from the sleeve. The lock or inhibition between the sleeve and the spindle is either released automatically as described above or this can be done by a defined engagement, for example by releasing a locking element or switching a ratchet or ratchet. The threaded insert is then anchored in the opening of the workpiece by driving the pin or wedge into the groove and into the workpiece, in which the sleeve is rotated relative to the spindle, the pressure piece and the spacer ring. As described above, this causes an axial relative movement between the sleeve and the pressure piece on the one hand and the fixed spindle with the spacer ring on the other hand.

The sleeve is preferably rotated by means of a motor-driven tool, for example by means of a drill, by means of a cordless screwdriver or by means of a pneumatic screwdriver. Such tools can be equipped with an overload clutch, for example a slip clutch, which prevent further drive of the sleeve when a maximum torque is reached. This can be used to complete the driving in of the pins or wedges when the sleeve or preferably the pressure piece has driven in the pins or wedges to such an extent that, for example, they are essentially flush with the sleeve-shaped base body of the insert. As a result of the contact of the sleeve or the pressure piece with the sleeve-shaped base body of the insert, the torque required for further rotation of the sleeve increases abruptly. With an appropriate selection of the maximum torque that can be transmitted by the overload clutch, this increase can be used to terminate the driving process in a defined manner.

The assembly tool can then be released from the workpiece and the threaded insert. This is done by changing the rotational movement of the sleeve. This preferably first causes a relative movement between the sleeve and the spindle again until the spindle is jammed with the sleeve again. Alternatively, this can also be achieved by actively operating a locking element or a ratchet or ratchet. The sleeve and spindle can then be rotated further together so that the spindle unscrews itself from the threaded insert. The assembly tool is now back in its original position.

The invention is explained in more detail below with reference to the accompanying drawing.

Fig. 1

in Explosionsansicht die Komponenten eines erfindungsgemäßen Montagewerkzeugs,

Fig. 2

in Schnittansicht das Montagewerkzeug nach Fig. 1,

Fig. 3

in Perspektivansicht das Montagewerkzeug nach Fig. 1,

Fig. 4

in Perspektivansicht das Montagewerkzeug nach Fig. 1,

Fig. 5

in Seitenansicht das Montagewerkzeug nach Fig. 1,

Fig. 6a bis 6f

in Seitenansicht Schritte der Montage eines Gewindeeinsatzes mit dem Montagewerkzeug nach Fig. 1,

Fig. 7a, 7b

in Schnittansicht Details der Schritte der Montage eines Gewindeeinsatzes mit dem Montagewerkzeug nach Fig. 1, und

Fig. 8

in Schnittansicht ein Montagewerkzeug nach einer weiteren Ausführungsform der Erfindung.

They show schematically:

Fig. 1

in an exploded view the components of an assembly tool according to the invention,

Fig. 2

the assembly tool according to a sectional view Fig. 1 ,

Fig. 3

the assembly tool according to in perspective view Fig. 1 ,

Fig. 4

the assembly tool according to in perspective view Fig. 1 ,

Fig. 5

the assembly tool according to the side view Fig. 1 ,

Figures 6a to 6f

in side view steps of the assembly of a threaded insert with the assembly tool according to Fig. 1 ,

Figures 7a, 7b

in sectional view details of the steps for assembling a threaded insert with the assembly tool Fig. 1 , and

Fig. 8

in sectional view an assembly tool according to a further embodiment of the invention.

The Figures 1 to 7b show a first embodiment of the assembly tool 1 according to the invention. The assembly tool 1 essentially consists of a sleeve 2 and a spindle 3. Optionally, the assembly tool 1 also has a pressure piece 4, a bearing 5, a locking ring 6, a spacer ring 7, a pin 8 and Magnets 9 on.

In the embodiment shown, the sleeve 2 is provided with an in the Figures 1 and 2 Formed lower cylindrical section, which forms a space for receiving a region of the pressure piece 4, the bearing 5 and the locking ring 6. One in the Figures 1 and 2 In the embodiment shown, the upper section of the sleeve 2 is hexagonal on the outside, ie with an engagement means for a torque-transmitting tool, such as a wrench or a motor-driven screwdriver. The upper section of the sleeve 2 defines a substantially cylindrical space which is provided with an internal thread 10. The upper space and the lower space of the sleeve 2 are spaced apart from one another by a radially inwardly projecting flange 11 which has a passage opening for the spindle 3. In the lower section of the sleeve 2, three permanent magnets 9 are introduced, which make it possible to hold the assembly tool 1 magnetically on a torque-transmitting tool.

As in the embodiment shown, the spindle 3 can have, for example, a cylindrical shaft which connects two sections each provided with an external thread to one another. In the illustrated embodiment, a in the Figures 1 and 2 The lower section of the spindle 3 is designed with an outer diameter that is smaller than that of the shaft. This lower section carries a first external thread 12. One in the Figures 1 and 2 The upper section of the spindle 3 is designed with a head-like enlarged outer diameter and has a second external thread 13. In this upper area of the spindle 3, a further engagement means for a torque-transmitting tool can be provided, which is designed as a hexagon socket in the embodiment shown.

The first external thread 12 of the spindle 3 can, as will be described in more detail below, be screwed into a threaded insert 14, which for example Figures 6a and 7a is shown. The second external thread 13 of the spindle 3 engages the internal thread 10 of the sleeve 2. In Fig. 2 the spindle 3 is screwed into the sleeve 2 so far that the shoulder between the shaft of the spindle 3 and the head of the spindle 3 bearing the second external thread 13 rests on the flange 11 of the sleeve 2. The lower side of the head of the spindle 3 in the figure forms a stop 11 ′ which, together with the flange 11 forming a counter-stop, act as a locking means for releasably inhibiting a rotation of the spindle 3 relative to the sleeve 2. Thus, in this position of the spindle 3 in the sleeve 2, the spindle 3 and the sleeve 2 are clamped together, similar to a tightly tightened nut on a threaded bolt. In other words, the sleeve 2 can only be rotated relative to the spindle 3 when a torque which overcomes this clamping is exceeded. Due to the engagement of the second external thread 13 in the internal thread 12, a relative rotation of the sleeve 2 to the spindle 3 also causes a relative axial movement through which the spindle 3 moves into the Figures 1 and 2 moved upward relative to the sleeve 2.

The pressure piece 4 is in the illustrated embodiment, a sleeve-like component with an in the Figures 1 and 2 upper flange-like end. The pressure piece 4 engages around the shaft of the spindle 3 in such a way that the spindle 3 can be moved in the axial direction relative to the pressure piece 4. The pressure piece 4 is rotatably mounted with its flange-like end in the lower region of the sleeve 2. For this purpose, the bearing 5 is provided between the sleeve 2 and the pressure piece 4, which is designed as a nail bearing in the embodiment shown. The pressure piece 4 is held in the sleeve 2 by means of the locking ring 6 in such a way that the pressure piece 4 does not move axially relative to the sleeve 2. At its end facing away from the sleeve 2 (in Figures 1 and 2 below) the pressure piece 4 is provided with an end wall 15 which, for example, can be stepped or, as in the embodiment shown, be provided with a phase. Furthermore, the pressure piece 4 can, as in the embodiment shown, with two each other opposite elongated holes 16 which extend in the longitudinal direction of the assembly tool 1.

The spacer ring 7 is also designed as an essentially sleeve-shaped component. The spacer ring 7 has an inner diameter that is slightly larger than the outer diameter of the pressure piece 4, so that the spacer ring 7 engages around the pressure piece 4, but is displaceable relative to it. The pin 8 attaches the spacer ring 7 to the pressure piece 4 and to the spindle 3 by the pin 8 reaching through lateral openings of the spacer ring 7, the elongated holes 16 of the pressure piece 4 and a transverse opening in the shaft of the spindle 3. In this way the spacer ring 7 is connected to the spindle 3 in a rotationally fixed and axially non-displaceable manner. In addition, the spacer ring 7 is connected to the pressure piece 4 in a rotationally fixed but axially displaceable manner.

How best to look Figure 7a As can be seen, the threaded insert 14 is also designed in the form of a sleeve and has an external thread 17 for screwing into a threaded opening of a workpiece 18. The threaded insert 14 is also provided with an internal thread 19 which is adapted to the first external thread 12 of the spindle 3. Grooves 20, which run in the axial direction, that is to say in the longitudinal direction of the assembly tool, are also formed in the outer circumferential surface of the threaded insert. A pin or wedge 21 is inserted into each groove 20 and is held in the groove 20 by clamping force. If necessary, the wedge 21 can also be detachably connected to the threaded insert 14 in some other way.

Before the assembly of the threaded insert 14, the wedges 21 stand out as from the Figures 6a and 7a can be seen, initially at the rear in the screwing-in direction, ie on the side facing away from the workpiece 18, over the base body of the threaded insert 14. Thus, the wedges 21 do not overlap, or at least only to a small extent, with the external thread 17 of the threaded insert 14, so that the screwing of the threaded insert 14 into the workpiece 18 is not hindered by the wedges 21. In principle, a single wedge 21 is sufficient to fix the threaded insert 14 in the workpiece 18. However, it is preferred if, as shown in the illustrated embodiment, at least two wedges 21 are provided on the threaded insert 14.

The following describes the assembly of a threaded insert 14 by means of the assembly tool 1 in a workpiece 18 with reference to FIG Figures 6a to 7b described in more detail:
At the beginning of the assembly process, the sleeve 2 and the spindle 3 are located relative to one another in the position shown in FIG Fig. 2 position shown, ie the spindle 3 is screwed up to the flange 11 in the sleeve 2 and clamped there in such a way that a small torque can be transmitted from the sleeve 2 to the spindle 3 without them moving relative to each other. This position is also referred to below as the first operating mode. This first operating mode can alternatively also be achieved in that an overload clutch is provided between the sleeve 2 and the spindle 3, which only allows a relative rotation of the sleeve 2 and the spindle 3 when a defined torque is exceeded. In addition or as a further alternative, another suitable locking means can be provided which releasably prevents a relative rotation of the sleeve 2 and the spindle 3.

As from the Figures 2 and 6a As can be seen, in this state the first external thread 12 of the spindle 3 protrudes over the end wall facing the workpiece 18 (in Fig. 2 below) of the spacer ring 7. The threaded insert 14 can thus be connected to the assembly tool 1 in that the sleeve 2 is rotated, whereby the spindle 3 is also rotated, and its first external thread 12 is screwed into the internal thread 19 of the threaded insert 14. The wedges 21 protrude into the ring-like space between the Spacer ring 7 and the shaft of the spindle 3. A shoulder 22 is preferably formed at the transition between the shaft of the spindle 3 and the first external thread 12, against which the sleeve-like base body of the threaded insert 14 strikes when the threaded insert 14 is completely screwed onto the spindle 3 is. This is in the Figures 7a and 7b to recognize.

The threaded insert 14 can then be guided together with the assembly tool 1 to the workpiece 18 provided with a threaded opening, the threaded insert 14 being screwed into the workpiece 18 in which the sleeve 2 is rotated further. The torque required for this is comparatively small, so that the clamping connection between the sleeve 2 and the spindle 3 is not released, but rather the torque is transmitted via the sleeve 2 into the spindle 3 and into the threaded insert 14. This is in the Figures 6b and 6c shown.

The screw-in depth of the threaded insert 14 into the workpiece 18 can be defined, for example, via the axial extent of the spacer ring 7. How out Figure 7a As can be seen, the axial distance D between the side of the shoulder 22 facing the workpiece 18 and the face of the spacer ring 7 facing the workpiece 18 determines the screwing depth of the threaded insert 14 into the workpiece 18. It meets the face of the spacer ring 7 on the surface of the Workpiece 18 when the threaded insert 14 is completely screwed into the workpiece 18.

If the distance D between the shoulder 22 of the spindle 3 and the end face of the spacer ring 7 is selected to be greater, ie if the spacer ring 7 is smaller than in the embodiment shown, the threaded insert 14 can be screwed deeper into the workpiece 18. Conversely, the threaded insert 14 ends flush with the workpiece surface when the shoulder 22 of the spindle 3 is flush with the end face of the spacer ring 7 or the threaded insert 14 protrudes beyond the workpiece surface 18 when the shoulder 22 of the spindle 3 is set back with respect to the end face of the spacer ring 7. By means of spacer rings 7 of different lengths, the screw-in depth of the threaded insert 14 can be adapted to different requirements.

Alternatively, the screw-in depth of the threaded insert 14 can also be limited by the fact that the wedges 21 hit the workpiece 18. In Figure 7a it is shown how an edge of the wedges 21 strikes against a phase of the opening in the workpiece 18 when the end face of the spacer ring 7 touches the surface of the workpiece 18.

The contact between the end face of the spacer ring 7 with the surface of the workpiece 18 or the contact of the wedges 21 with the workpiece 18 causes the torque required to screw in the threaded insert 14 suddenly increases when the rotation of the spindle 3 with the threaded insert 14 penetrates further into the workpiece 18 and at the same time the spacer ring 7, which is axially connected to the spindle 3 via the pin 8, is pressed against the surface of the workpiece 18. This increase in torque causes a loosening of the clamping connection between the sleeve 2 and the spindle 3. If a slip clutch is provided between the sleeve 2 and the spindle 3, the maximum transferable torque is set, for example, so that the slip clutch slips when the spacer ring 7 hits the workpiece surface. Alternatively, a lock between the sleeve 2 and the spindle 3 can also be released manually or automatically at this point in time. As a result of this process, the assembly tool 1 is transferred to its second operating mode, in which the sleeve 2 and the spindle 3 can be rotated relative to one another.

As in the Figures 6d and 7b is shown, with a continued rotation of the sleeve 2 in the second operating mode, a relative axial movement between the sleeve 2 and the spindle 3 causes. The spacer ring 7 is firmly connected axially to the spindle 3 and remains in the in Figure 7a position shown. Due to the relative movement between the sleeve 2 and the spindle 3, the pressure piece 4 is also moved relative to the spindle 3 (in Fig. 2 down). As a result of this movement, the end wall 15 of the pressure piece 4 hits the side facing the assembly tool 1 (above in Figures 7a and 7b ) of the wedges 21 and drives this further into the grooves 20 and into the workpiece 18 as the sleeve 2 continues to rotate. As a result, the threaded insert 14 is anchored in the workpiece 18 in a rotationally fixed manner. This state is in Figure 7b shown.

As soon as the end wall 15 of the pressure piece 4 or the phase attached to it comes into contact with the workpiece 18, the torque increases again significantly. This second increase in torque can be used to switch off a tool driving the assembly tool 1, for example by means of a slip clutch.

The assembly tool 1 can now be returned to its first operating mode and screwed out of the workpiece 18 and the threaded insert 14. For this purpose, the direction of rotation of the tool driving the sleeve is reversed, as shown in FIG Figures 6e and 6f is indicated. Since the spindle 3 and the spacer ring 7 are at least slightly clamped to the workpiece 18 via the threaded insert 14, if the direction of rotation of the sleeve is reversed, a relative movement between the sleeve 2 and the spindle 3 occurs again until the spindle 3 reaches the position shown in Fig. 2 has reached the starting position shown. When it hits the flange 11 of the sleeve 2, the spindle 3 jams again with the latter, so that the spindle 3 and the sleeve 2 are in their first operating mode that is connected to one another in a rotationally fixed manner. Alternatively or additionally, this can be done via a manually or automatically intervening locking device. As the sleeve 2 continues to rotate, the first The external thread 12 of the spindle 3 is unscrewed from the threaded insert 14, whereby the assembly process is completely completed.

An alternative embodiment is shown in FIG Fig. 8 shown. The construction of the assembly tool 1 is essentially the same as that of the previously described embodiment. Identical components are therefore given the same reference numerals. The difference between the first embodiment and the embodiment according to Fig. 8 is that on the spacer ring 7 'after Fig. 8 an external thread 23 is provided. An adjusting ring 24 is screwed onto this external thread 23 with an internal thread. A lock nut 25 is also provided, which likewise engages with the external thread 23. The setting ring 24 can be fixed in its position on the spacer ring 7 'by means of the lock nut 25. With the lock nut 25 loosened, the position of the adjusting ring 24 relative to the spacer ring 7 'can be changed. In this way, the distance between the end face of the setting ring 24 facing the workpiece 18 and the shoulder 22 of the spindle 3 is also changed at the same time. In this way, the screw-in depth of a threaded insert 14 into a workpiece 18 can be adjusted without replacing the spacer ring 7 ′ by setting the position of the setting ring 24 accordingly.

In a simplified embodiment (not shown) of the assembly tool according to the invention, the spacer ring 7 or 7 'can be completely omitted. Switching between the first and second operating mode can be triggered, for example, by the fact that the wedges 21 strike the surface of the workpiece 18. Alternatively, the screwing-in process can be ended in the first operating mode by stopping the sleeve 2. The clamping connection between the spindle 3 and the sleeve 3 can then be released by holding the spindle 3 at least briefly relative to the sleeve 2, which then continues to rotate. This can be the case with the Fig. 1 The embodiment shown takes place via the means of attack in the head of the spindle 3. In a corresponding manner, the first operating mode can be restored when the spindle 3 and the sleeve 2 are braced against one another by appropriate tool engagement.

In a further simplified embodiment, also not shown, the pressure piece 4 can be designed in one piece and / or non-rotatably with the sleeve 2 if the bearing 5 is omitted. In this case, while the wedges 21 are being driven in in the second operating mode, the end wall 15 and the wedges 21 rotate relative to each other. This is fundamentally undesirable because this relative movement generates friction and can possibly damage the wedges 21. The friction can be counteracted by a corresponding design of the end face 15, for example with a coating. In this embodiment, a spacer ring can be provided as described in detail above or can be omitted, as described in relation to the simplified embodiment.

With the assembly tool 1 according to the invention, the complete installation is converted into a pure rotary movement (left / right). The stroke for pressing in the wedges 21 is generated by a rotary movement by means of the thread 10/13. Tool 1 is compatible with standard screwdrivers and wrenches. The installation depth can be set very precisely, the load on the workpiece 18 being minimal. In addition, the installation is very ergonomic and quiet because, unlike before, you do not have to work with a hammer. Furthermore, the assembly tool 1 enables the installation of a threaded insert 14 even with a low overall height and is characterized by good accessibility for limited space.

Reference number:

1

Assembly tool

2

Sleeve

3

spindle

4th

Pressure piece

5

camp

6th

Circlip

7, 7 '

Spacer ring

8th

pen

9

magnet

10

inner thread

11

Flange

11 '

Stop (locking means)

12th

first external thread

13th

second external thread

14th

Thread insert

15th

Front wall

16

Long hole

17th

External thread

18th

workpiece

19th

inner thread

20th

Groove

21

wedge

22nd

paragraph

23

External thread

24

Adjustment ring

25th

Lock nut

D.

distance

Claims (10)

1. Assembly tool for threaded inserts with a spindle (3) which is provided at least in sections with a first external thread (12) and at least in sections with a second thread (13), a sleeve (2), comprising a standing thread (10) that engages with the second thread (13), and locking means (11) for the releasable inhibition of a rotation of the spindle (3) relative to the sleeve (2), wherein the length of the spindle (3) and the length of the sleeve (2) are adapted to one another in such a way that the first external thread (12) protrudes at least partially from the sleeve (2), characterized in that the spindle (3) is coupled non-rotatable to a spacer ring (7, 7') surrounding it at least in sections, wherein the spacer ring (7, 7') is axially movable along with the spindle (3) relative to the sleeve (2).
2. Assembly tool according to Claim 1, characterized in that the locking means comprise a stop (11') for the spindle (3) and a counter-stop (11) for the sleeve (2), which releasably block a rotation of the spindle (3) relative to the sleeve (2) when the stop (11') rests against the counter-stop (11).
3. Assembly tool according to Claim 1 or 2, characterized in that a pressure piece (4) arranged radially outside the spindle (3) is mounted on or in the sleeve (2), wherein the length of the pressure piece (4) and the length of the spindle (3) and the length of the sleeve (2) are adapted to one another in such a way that the first external thread (12) at least partially protrudes from the sleeve (2) and from the pressure piece (4), and wherein the pressure piece (4) comprises an end wall (15) on the side facing away from the sleeve (2).
4. Assembly tool according to Claim 3, characterized in that the pressure piece (4) is mounted on or in the sleeve (2) to be freely rotatable relative to the sleeve (2) but not axially displaceable relative to the sleeve (2).
5. Assembly tool according to any of the Claims 3 or 4, characterized in that the spacer ring (7, 7') is secured in the spindle (3) by means of a pin (8), wherein elongated holes (16) are provided in the pressure piece (4), into which the pin (8) is guided.
6. Assembly tool according to Claims 3 or 4 and 5, characterized in that the spacer ring (7, 7') can be moved axially relative to the pressure piece (4).
7. Assembly tool according to any of the Claims 5 or 6, characterized in that the spacer ring (7') comprises an external thread (23), which engages with the internal thread of an adjusting ring (24) surrounding the spindle (3) at least in sections.
8. Assembly tool according to any of the Claims 5 to 7, characterized in that
   the sleeve (2) comprises a first cylindrical section, in which the thread (10) designed as an internal thread is provided, and a second cylindrical section, which is spaced from the first section by a radially inwardly protruding web or flange (11) and in which a flange section of the pressure piece (4) is rotatably mounted and secured against axial movement,
   the spindle (3) comprises a shaft, at the first end of which the first external thread (12) and at the opposite second end of which the second thread (13), designed as an external thread, is provided, wherein the second end comprises an enlarged diameter compared to the shaft,
   the pressure piece (4) engages with the shaft of the spindle (3) and comprises two elongated holes (16), into which the spacer ring (7, 7') is guided in a non-rotatable and axially movable fashion by means of a pin (8),
   the sleeve (2) and the spindle (3) are each equipped with engagement means for a torque-transmitting tool, and/or
   on the side of the pressure piece (4) facing away from the sleeve (2), an end wall (15) provided with a chamfer and/or a shoulder is formed.
9. Use of an assembly tool (1) according to any of the preceding claims for fastening a threaded insert (14) in an opening of a workpiece (18), wherein the threaded insert (14) is designed as a sleeve with an external thread (17) and an internal thread (19), wherein at least one longitudinally extending groove (20) is formed in the outer surface of the threaded insert (14), in which groove a pin (21) is received, wherein the internal thread (19) of the threaded insert (14) is adapted to the first external thread (12) of the spindle (3) and the radial position of the pin (21) is adapted to the radial position of the end wall (15) of the pressure piece (4).
10. Method for fastening a threaded insert (14) in an opening of a workpiece (18), comprising the following steps:

    • Provision of an assembly tool (1) according to any of the preceding claims and a threaded insert (14) adapted to the assembly tool (1), wherein the threaded insert (14) is designed as a sleeve with an external thread (17) and an internal thread (19), wherein at least one longitudinally extending groove (20) is formed in the outer surface of the threaded insert (14), in which groove a pin (21) is received in such a way that the pin (21) does not extend completely in the axial direction along the external thread (17) of the threaded insert (14),

    • Screwing of the threaded insert (14) onto the first external thread (12) of the spindle (3) while a rotation of the spindle (3) relative to the sleeve (2) is inhibited or blocked,

    • Screwing of the threaded insert (14) into the opening of the workpiece (18) through a rotation of the sleeve (2) together with the spindle (3) until the spacer ring (7, 7') or adjustment ring (24) meets the workpiece (18) with its end face facing away from the sleeve (2),

    • Release of the block or inhibition between the sleeve (2) and the spindle (3),

    • Anchoring of the threaded insert (14) in the opening of the workpiece (18) by driving the pin (21) into the groove (20) and into the workpiece (18) by means of a rotation of the sleeve (2) relative to the spindle (3), the pressure piece (4), and the spacer ring (7, 7').

Images