EP3212361B1 - Installation tool for a wire thread insert having an installation pin that can be bent back, and installation method - Google Patents

Description

1. Field of the invention

The present invention relates to an installation tool for a wire thread insert for installation in a receiving thread of a component and to an installation method for this wire thread insert in the component with a receiving thread.

2. Background of the invention

Various wire thread inserts for installation in a receiving thread of a component are known in the prior art. For example, you are in US-A-2,363,789 , EP-A-0 140 812 and EP-A-0 157 715 described. The outer diameter of the cylindrical walls of the wire thread insert must regularly be selected to be somewhat larger than the outer diameter of the receiving thread of the component. Therefore, the installation of the wire thread insert into the receiving thread of the component must be done with a diameter reduction of the wire thread insert. In this way it is ensured that the elastic return deformation of the wire thread insert after installation in the receiving thread ensures that the wire thread insert is firmly seated.

In order to make it easier to screw the wire thread insert into the receiving thread, ( EP-B1-0 228 981 ) half a turn at the end of the cylindrical helix of the wire thread insert is drawn in radially inward. The smallest outer diameter of the drawn-in section of the wire thread insert should be approximately equal to or slightly larger than the associated outer diameter of the receiving thread in the component. Furthermore, in this known wire thread insert, the wire cross-section is tapered at the end in order to facilitate the screwing of the wire thread insert into the receiving thread and to avoid damage to the threaded hole in the component.

Various designs of wire thread inserts are also in EP-B1-0 983 445 disclosed. A wire thread insert is composed of a cylindrical helix with a plurality of helically wound turns. A first turn of this cylindrical helix opens into an installation pin which projects radially in a straight line into the cylindrical helix. This installation pin is gripped with the aid of a suitable installation tool and thus the wire thread insert is screwed into the receiving thread of the component. After the installation has been completed, the mounting pin is removed by breaking it off with the aid of a predetermined breaking point in the first turn. In this way, a receiving thread is created with a wire thread insert that can be screwed through.

DE 1 016 066 B discloses a locking screw to which a wire thread insert is attachable. For this purpose, the locking screw has a transverse slot on one end face, in which a radially inwardly bent driver pin of the wire thread insert can be received. In order to be able to remove the locking screw from the wire thread insert, an internal channel is provided in the locking screw which ends at the transverse slot. A pin can be inserted through this channel, with which the driver pin is pressed out of the transverse slot. The driving pin is neither bent excessively, broken off or permanently deformed. The locking screw can then be removed from the wire thread insert.

DE 10 2010 050 735 describes various alternatives of a wire thread insert with a pin that can be bent back but not removed. The tenons are used to install the wire thread insert in a threaded component opening. After installation, the pin is bent back into the circumferential shape of the wire thread insert without later hindering the screwing of a threaded bolt into the wire thread insert. Bending back is done with an installation tool with a compression blade. The edging blade exerts a force on the free face of the pin and thereby bends it back. In order to make it easier to bend back, a bending area between the helix and the pin of the wire thread insert has a tapering notch or a driving notch. The driving notch serves as a taper in the bending area and as an installation aid for the wire thread insert in the component opening.

Based on the known wire thread inserts with bendable and non-removable peg, the technical task of the present invention is to provide an alternative, technically simple and robust installation tool and an alternative installation method with which the wire thread insert can be installed in a threaded component opening.

3. Summary of the invention

The above object is achieved by the installation tool according to independent patent claim 1 and by the installation tool according to independent patent claim 7. Furthermore, the above object is achieved by the installation method according to the independent patent claim 11. Advantageous embodiments and further developments of the present invention emerge from the dependent patent claims, the description and the accompanying drawings.

The installation tools according to the invention are adapted to a wire thread insert which has a cylindrical helix with a plurality of helically wound turns of a wire. A first turn comprises a driver pin with a driver notch protruding into the interior of the helix via a bending region. The driver pin protrudes radially inwardly with respect to the helix and forms an angle of <90 ° with a second turn of the helix that extends in the direction of travel of the driver pin.

According to a first alternative, the installation tool has the following features: a rotatable installation spindle with a drive end for rotating the installation spindle and a functional end for installing the wire thread insert, the functional end comprising at least one thread which is reduced in length in the circumferential direction and which has a driver edge at a first end for engagement has in a driver notch of the wire thread insert and at a second end a bent shoulder for radially outward bending of the driver pin of the wire thread insert.

The installation tool has an installation spindle, known per se, on the functional end of which the wire thread insert to be installed can be fastened in a rotationally fixed manner, so that it can be screwed into a threaded component opening by turning the installation spindle. The installation spindle is rotated via the drive end, which is moved manually or with the aid of a motor drive. On the functional end of the installation spindle, the wire thread insert can be fastened in a rotationally fixed manner in one direction of rotation of the installation spindle. In this context, it is preferred, on the one hand, that the functional end has a matching external thread, so that the wire thread insert can be screwed onto this external thread. According to another preferred embodiment, the functional end has an outer diameter that is smaller than the inner diameter of the wire thread insert. Due to this dimensioning, it is possible to attach the wire thread insert to the functional end of the installation tool.

At the functional end, which is arranged opposite the drive end of the installation spindle, a thread with a reduced circumferential length is arranged. This means that at the functional end of the built-in spindle facing away from the drive end, viewed in the longitudinal direction of the built-in spindle, at least one last thread turn is reduced in length such that this last thread turn does not extend over an angle of rotation of 360 ° around the longitudinal axis of the built-in spindle. Rather, the length-reduced thread extends in the circumferential direction preferably over a length which is defined by an angle of rotation of 270 °, preferably 180 °, about the longitudinal axis of the installation spindle.

While the at least one length-reduced thread turn in the circumferential direction forms a radial outer side for contact with the wire thread insert to be installed, the two opposite ends of the length-reduced thread turn are designed as functional elements. The driver edge, which is formed by a radially inner and a radially outer leg, is preferably located at one end. The radially inner and the radially outer leg preferably enclose an angle of <90 °.

The bending shoulder is arranged at the other end of the at least one length-reduced thread turn. The bend-up shoulder has a web which is inclined radially inward and counter to the screwing-in direction of the installation spindle and which preferably encloses an angle of <90 ° with a radial outer edge of the installation spindle. Due to its preferred acute-angled configuration, the driver edge forms a blade-like guide in the screwing-in direction of the wire thread insert which, because of its arrangement, engages in a form-fitting manner in the driver notch of the wire thread insert. This form-locking engagement ensures a non-rotatable connection between the installation spindle and the wire thread insert in the screwing direction or installation direction of the wire thread insert in the component opening. The bend-up shoulder, on the other hand, only acts when the installation spindle is rotated counter to the installation direction, i.e. when the installation spindle is removed from the wire thread insert while rotating. Due to its preferred angled configuration, when the installation spindle is unscrewed, the driver pin runs into an angle that is formed by the bent shoulder and the radially inner wall of the component opening. With further rotation, the bent shoulder presses the driver pin against the radially inner component opening, so that the driver pin is permanently bent back into the outer contour of the wire thread insert becomes. The bend-up shoulder slides against the screwing-in direction of the wire thread insert along the driver pin.

In order to advantageously support this bending back of the driver pin, the bent shoulder is designed to be curvilinear according to a preferred embodiment of the present invention. Correspondingly, the bend-up shoulder has an increasing curvature in its course radially inwards in relation to the installation spindle. In addition, it is preferred that the bent-up shoulder is integrally connected to the entrainment edge via the at least one length-reduced thread turn.

The present invention encompasses another alternative of the wire thread insert installation tool. The wire thread insert consists of a cylindrical helix with a plurality of helically wound turns of a wire, in which a first winding has a driving pin with a driving notch protruding over a bending area into the interior of the helix. The installation tool comprises the following features: a rotatable installation spindle with a drive end for rotating the installation spindle and with a functional end for installing the wire thread insert in a component opening, in which the functional end has a first thread area with a first core diameter and a second thread area with a second core diameter, wherein the second thread area is arranged between the drive end and the first thread area, wherein the first core diameter is larger than the second core diameter and wherein the functional end has a recess in a thread that forms an undercut for the driver pin of the wire thread insert in the screwing direction of the wire thread insert.

The second alternative according to the invention of the installation tool is characterized by a functional end with two mutually adjacent thread areas. The second threaded area essentially serves to accommodate the wire thread insert to be installed. If the wire thread insert is located in this thread area, it is preferably installed in a component opening of a component. The first thread area, which has a larger core diameter than the second thread area, is arranged such that when the installation spindle is removed from the installed wire thread insert, this first thread area must be screwed through the installed wire thread insert. Due to the larger core diameter of the first thread area, which is when unscrewed If the installation spindle is forced out of the wire thread insert through the wire thread insert, the driving pin with the driving notch is bent back radially outwards into the circumferential outer contour of the wire thread insert. Since different mechanical stresses are preferably superimposed in the bending area, the driver pin is permanently bent back into the circumferential contour of the wire thread insert. Preferably, after the bending back, the driver pin is arranged accurately or true to gauge in the outer contour of the wire thread insert or in the thread of the installation opening of the wire thread insert.

The above-mentioned recess is provided in order to keep the wire thread insert spindled or plugged onto the functional end during installation. This recess is preferably arranged in the second thread area, preferably within an angle of rotation of 270 ° beginning on or adjacent to the first thread area. The radially inwardly curved driving pin with driving notch snaps into this recess when the wire thread insert is spindled or pushed onto the functional end. The arrangement of the recess at a distance from the first thread area guarantees that the first thread area in combination with the radial inner wall of the component opening only generates sufficient mechanical stresses in the drive pin when the installation spindle is spindled out of the installed wire thread insert, which permanently bends the drive pin back.

It is further preferred that the first core diameter is at least 0.1% larger than the second core diameter, preferably in a range from 0.1% to 2% larger than the second core diameter. According to a further preferred embodiment of the present alternative of the installation tool, the first threaded area extends over an angle of rotation of at least 180 ° around the longitudinal axis of the installation spindle.

The present invention also comprises an installation method of the wire thread insert with a bendable, non-removable driver pin and a driver notch using an installation tool according to claim 1 or 7 in a receiving thread of a component, which has the following steps: spinning or plugging the wire thread insert onto a functional end of an installation spindle of the installation tool in this way that the driving notch positively coupled to a driver edge or a radial recess of the installation tool and the

Connects the wire thread insert to the installation tool in a rotationally fixed manner, screwing the wire thread insert into the receiving thread by turning the installation spindle in a first direction of rotation, bending the driving pin back into the receiving thread by turning the installation spindle in a second direction of rotation and spinning or removing the installation spindle from the wire thread insert with the driving pin bent back.

In the context of the installation method, it is further preferred that the driver pin is bent back radially by a bend-up shoulder or a second threaded area with an enlarged core diameter compared to a first threaded area at the functional end of the built-in spindle.

4. Brief description of the accompanying drawings

Fig. 1

eine stirnseitige Ansicht einer bevorzugten Ausführungsform eines Drahtgewindeeinsatzes mit zurückbiegbarem Mitnehmerzapfen und Mitnehmerkerbe,

Fig. 2

eine stirnseitige Ansicht einer weiteren bevorzugten Ausführungsform eines Drahtgewindeeinsatzes mit zurückbiegbarem Mitnehmerzapfen und Mitnehmerkerbe,

Fig. 3

eine perspektivische Ansicht eines bevorzugten Drahtgewindeeinsatzes mit zurückgebogenem Mitnehmerzapfen und mit Mitnehmerkerbe,

Fig. 4

eine stirnseitige Ansicht einer bevorzugten ersten Alternative des erfindungsgemäßen Installationswerkzeugs,

Fig. 5

eine stirnseitige Ansicht einer weiteren bevorzugten ersten Alternative des Installationswerkzeugs,

Fig. 6

eine seitliche Schnittansicht der bevorzugten ersten Alternative des Installationswerkzeugs,

Fig. 7

eine seitliche Schnittansicht einer bevorzugten zweiten Alternative des Installationswerkzeugs,

Fig. 8

eine schematische Ansicht der beiden Gewindebereiche der bevorzugten zweiten Alternative des Installationswerkzeugs und

Fig. 9

ein Flussdiagramm einer bevorzugten Ausführungsform des erfindungsgemäßen Installationsverfahrens des Drahtgewindeeinsatzes in einem Innengewinde einer Bauteilöffnung eines Bauteils mit einem Installationswerkzeug.

The various / preferred embodiments of the present invention are explained in more detail with reference to the accompanying drawings. Show it:

Fig. 1

an end view of a preferred embodiment of a wire thread insert with a retractable driver pin and driver notch,

Fig. 2

an end view of a further preferred embodiment of a wire thread insert with a retractable driver pin and driver notch,

Fig. 3

a perspective view of a preferred wire thread insert with bent back driving pin and with driving notch,

Fig. 4

an end view of a preferred first alternative of the installation tool according to the invention,

Fig. 5

an end view of another preferred first alternative of the installation tool,

Fig. 6

a side sectional view of the preferred first alternative of the installation tool,

Fig. 7

a side sectional view of a preferred second alternative of the installation tool,

Fig. 8

a schematic view of the two threaded areas of the preferred second alternative of the installation tool and

Fig. 9

a flow chart of a preferred embodiment of the inventive installation method of the wire thread insert in an internal thread of a component opening of a component with an installation tool.

5. Detailed Description of the Preferred Embodiments

The present invention relates to different alternatives of an installation tool for installing a wire thread insert 1 in a component opening with an internal thread of a component. The use and dimensioning of wire thread inserts 1 is known in the prior art.

The wire thread insert 1 according to the invention is wound from a wire of known material and known cross-sectional shape. Referring to the Fig. 1-3 the wire thread insert 1 comprises a cylindrical helix 20 consisting of a plurality of helically wound turns 30. The helix 20 has a first end 22 and a second end 24. At the first end 22 of the cylindrical helix 20 there is a driving pin 50 with a driving notch 42 which protrudes into the interior of the cylindrical helix 20 in a radial plane of the cylindrical helix 20.

The driver pin 50 is connected via a bending region 40 to a first turn 32 of the cylindrical helix 20 at its first end 22. The driving pin 50 does not protrude in a straight line radially into the interior of the cylindrical helix 20, as shown in FIG Figs. 1 and 2 can be seen. Instead, the driver pin 50 has approximately the shape of an arc. The circular arc of the driving pin 50 preferably has the same or a larger radius than the cylindrical helix 20, so that the driving pin 50 can be permanently bent back from the interior of the cylindrical helix 20 into the course of the first turn 32. It is also preferred to form the circular arc of the driver pin 50 with a radius which differs from the radius of the cylindrical helix 20 by a maximum of ± 1%. In addition, the driver pin 50 closes with the circumferential contour of the wire thread insert an angle α. The angle α is preferably smaller than 90 ° and forms an acute angle. It has been shown that in the case of a driving pin 50 with a length of 0.2 U to 0.4 U, this advantageously extends from an angle α of 5 ° α 50 °, preferably 1 ° α 35 °, into the Can be bent back circumferential contour of the wire thread insert 1. It has an advantageous effect that the length of the driving pin 50 rests against the installation tool (see below) via frictional engagement. As a result, a multiaxial mechanical stress state is transferred to the bending area 40, which ensures that the driver pin is permanently bent back. In the case of a driving pin 50 with a preferred length L _Z of 0.05 U L _Z 0.1 U, the driving pin 50 is preferably arranged in an angular range of 5 ° α 45 °, preferably 5 ° α 30 ° . The size U designates the circumference of the wire thread insert 1, which can be calculated from the radius or the diameter of the wire thread insert 1.

The function of the bending area 40 is to connect the driver pin 50 to the rest of the wire thread insert 1 in a flexible and tensile manner. This ensures that, when the wire thread insert 1 is installed in a receiving thread A of a component B, a sufficiently high torque can be applied to the wire thread insert 1 via the driver pin 50. Based on this structural basis, the wire thread insert 1 can be drawn into the receiving thread A via the driver pin 50 without the driver pin 50 breaking off. In order to be able to transmit the required torque for screwing the wire thread insert into the component opening on the wire thread insert, the wire thread insert has the driving notch 42. The driving notch 42 exists in the screw-in direction R (see Fig. 1, 2 ) from a radial recess on a radial inner side of the bending area 40. In the screwing-in direction R, the driving notch 42 has an undercut 43, which enables a non-rotatable coupling (in the screwing-in direction R) of an installation tool (see below) to the driving notch 42 and turning the wire thread insert 1 allowed. The driver notch 42 is preferably positioned such that the undercut 43 is arranged within the circumferential contour of the wire thread insert 1. The undercut 43 preferably projects radially inward beyond the inner edge 25 of the wire thread insert 1. In this way, coupling between the installation tool and the wire thread insert is supported.

In addition, the bending area 40 ensures that the driver pin 50 is permanently in the receiving thread A of the component B or generally in the course of the first turn 32 can be bent back. For this purpose, the bending region 40 has the same mechanical, thermal, chemical and geometric properties as the wire of the cylindrical helix 20. With the aid of a suitable installation tool (see below), the driver pin 50 is bent in the radial direction out of the interior of the cylindrical helix 20 when it is bent back, without the driver pin 50 subsequently returning elastically into the interior of the cylindrical helix 20. This state is in Fig. 4 illustrated.

In order to support the bending back of the driver pin 50 into the receiving thread A or into the course of the first turn 32, the bending properties of the wire in the bending area 40 are preferably changed compared to the wire of the cylindrical helix 20. This change in the bending area 40 is generated mechanically, geometrically, thermally, chemically or in some other way according to different embodiments of the present invention.

According to the Fig. 2 and 3 In the preferred embodiment shown, the wire of the bending region 40 is tapered in its cross section in comparison to the wire of the cylindrical helix 20. This is implemented via the driver notch 42. The taper or notch 42 is designed in such a way that a small notch factor arises when the driver pin 50 is bent back and therefore the driver pin 50 does not break off during the bending back. The driving notch 42 is arranged on the radial inside of the bending area 40. The driver notch is shaped and positioned in such a way that, in order to screw the wire thread insert 1 into a receiving thread, it can run into a driver blade or edge located in the contour of the screwing tool and is hooked onto it in a form-fitting manner. How to get into the Fig. 2 and 3 can see, the upstream side of the driver notch 42 in the screwing-in direction of the wire thread insert 1 forms an undercut against which the driver blade rests in a form-fitting manner. The radially inwardly curved driving pin 50 supports the engagement of the driving blade or edge in the driving notch 42 because at least the side of the driving notch 42 which is upstream in the screwing direction protrudes radially inward over the circumferential contour into an interior of the wire thread insert 1. The driver notch 42 thus realizes two functions at the same time. On the one hand, it enables the engaging and locking of the driver blade or edge of an installation tool for the wire thread insert 1. On the other hand, it represents a tapering of the bending area 40, which supports bending of the driver pin 50 back into the receiving thread of the component.

In order to reduce the mechanical resistance torque or the elastic restoring torque of the wire in the bending area 40, for example from up to 2000 MPa to approx. 400 MPa, the bending area is machined for this purpose. Suitable methods include notching, milling, stamping, forging, grinding, polishing, cold hammering, pickling, lapping to reduce the cross-section of the bending area 40. At the same time, it must be ensured that the corrosion properties in the bending area 40 are restored after the machining.

The preferred wire thread insert 1 can therefore be summarized as follows: Wire thread insert 1 for installation in a receiving thread of a component, which has the following features: a cylindrical helix 20 consisting of a plurality of helically wound turns 30 of a wire, which have a first 22 and a second End 24, wherein a first turn 32 provided at the first end 22 has a driver pin 50 protruding over a bending area 40 into an interior 26 of the coil 20 with a driver notch 42 and wherein the driver pin 50 is inseparably connected to the first turn 32, via which Bending area 40 can be bent back out of the interior 26 of the helix 20 and the wire thread insert 1 can be installed via the driver notch 42 and the driver pin 50. Further preferably, the driver pin 50 of the wire thread insert 1 can be bent back permanently into the receiving thread A of the component B. In addition, the driver pin 50 is preferably an arc of a circle, the pin radius of which is approximately equal to a radius of the first turn 32 of the cylindrical helix 20. For further design details of the wire thread insert see DE 10 2010 050 735 which is hereby incorporated by reference.

Based on the above-described configurations of the bending area 40 and the shape of the driver pin 50, the driver pin 50 of a wire thread insert 1 installed in the receiving thread A of component B can be bent out of the interior of the cylindrical helix 20 so that the receiving thread A is true to gauge with the wire thread insert 1 . This means that a screw or a thread plug gauge can be screwed into the receiving thread A with the wire thread insert 1 with a negligibly small additional torque or frictional torque due to the bent back driving pin 50. The accuracy of the gauge of the receiving thread A with the wire thread insert 1 can be demonstrated by the fact that manual screwing in of the thread plug gauge according to tolerance class 6H, preferably tolerance class 5H, is guaranteed.

According to different configurations of the present invention, the driver pin 50 is of different lengths (see above). When bent back according to Fig. 3 the driver pin 50 extends over a circular arc A _RZ with a length Lz of 0.05 U L _Z 0.4 U, preferably 0.2 U L _Z 0.4 U or 0.05 U L _Z 0.1 U. Here, U denotes the outer circumference of the wire thread insert. The length Lz of the driver pin is measured starting in the bending area 40 to the free end of the driver pin 50.

The Figs. 1 and 2 show two preferred embodiments of a wire thread insert 1, which are installed in a component opening using the installation tools described in more detail below. Fig. 3 shows schematically a wire thread insert 1 with bent back driving pin 50, as it would be arranged installed in a component opening.

The wire thread insert 1 is using an installation tool 60; 60 'built into the threaded component opening (not shown). Two alternative preferred constructions of installation tool 60; 60 'are in the Figures 4-6 and 7-8 illustrated schematically. When describing the alternative installation tools 60; 60 ', the same structural details are denoted by the same reference symbols. In addition, descriptions of these same structural details apply equally to both alternatives of the installation tool 60; 60 ', even if they have only been discussed in connection with an alternative.

The installation tools 60; 60 'each comprise a rotatable installation spindle 62 with a drive end 64 and a functional end 70; 70 '. The installation spindle 62 can be rotated manually or by machine with a corresponding, for example electromotive, drive (not shown) via the drive end 64. First, the wire thread insert 1 is on the functional end 70; 70 'attached (step S1). To do this, take the wire thread insert 1, for example, between your thumb and forefinger and screw the functional end 70; 70 'of the installation spindle 62 into the wire thread insert 1. The end of function 70; 70 ′ runs into the end face of the wire thread insert 1, which is opposite the end face of the wire thread insert 1 with the driving pin 50. Depending on whether the wire thread insert 1 has a right-hand or left-hand thread, the installation spindle 62 is rotated to the right or to the left.

According to another preferred embodiment of the present invention, the function end 70; 70 'of the installation spindle 62 in diameter smaller than an inside diameter of the wire thread insert 1. In this case, the wire thread insert 1 is on the functional end 70; 70 'plugged on in order to arrange or fasten it on or to the installation spindle 62. Although the accuracy of the built-in wire thread insert is impaired in this case, it is possible to screw a screw into the installed wire thread insert.

A preferred embodiment of the first alternative of the installation tool 60 is shown in FIGS Fig. 4-6 shown. The functional end 70 of the installation spindle 62 has a threaded section 72 designed to match the wire thread insert 1. The threaded section 72 extends, starting at the free end of the installation spindle 62, preferably over at least a partial length of the functional end 70. According to one embodiment of the present invention, this partial length corresponds to at least one axial length of the wire thread insert 1, so that its full length can be screwed onto the functional end 70 . It is also preferred to make the threaded portion 72 shorter. In this case, in the fastening direction B of the wire thread insert 1, on the functional end 70, a receiving area 74 of a smaller diameter than the threaded section 72 adjoins the threaded section 72. This receiving area 74 allows the wire thread insert 1 to run up and later to be supported and guided without the function of the thread section 72 being restricted.

The thread section 72 comprises a circumferential thread which extends helically around the installation spindle 62 at the functional end 70. The thread turn is formed by two radially outwardly projecting opposing flanks, between which the helically bent wire of the wire thread insert 1 is guided. Near the free end of the functional end 70, which faces away from the drive end 64, the thread 72 is perforated (opening 73). Within the opening 73, the wire of the wire thread insert 1 is not supported or guided on both sides by flanks of the thread over the length range of an angle of rotation γ of preferably at least 360 °. Due to this opening 73 or the length range without flanks at least on one side, defined by the angle γ and the diameter of the functional end 70, the functional end 70 comprises a length-reduced first thread 72a and a second thread 72b.

The opening 73 is formed by an end face axial extension 80 of the functional end 70, which protrudes counter to the fastening direction B of the wire thread insert 1 from the end face of the functional end 70. The extension 80 extends only over part of the end face, as can be seen in the Figures 4 and 5 can recognize. As a result, part of the face of the functional end 70 jumps back behind the extension 80, as a result of which the opening 73 is created.

The extension 80 is defined along a circumferential path by the length-reduced first thread 72a. The length-reduced first thread turn 72a and thus one side of the extension 80 preferably extend over an arc length S defined by an angle β. The angle β has a preferred size of 150 ° β 240 °.

In the screwing direction R of the functional end 70 into the wire thread insert 1, the front end of the length-reduced first thread 72 and thus also the front end of the extension 80 has a driver edge 82. The driving edge 82 preferably extends parallel to the longitudinal axis of the installation spindle 62. The course of the driving edge 82 can, however, also deviate from this orientation as long as the functional interaction between the driving notch 42 and the driving edge 82 is guaranteed. If the functional end 70 is screwed in the screwing direction R into the wire thread insert 1 with the driving notch 42 (step S1), the driving edge 82 runs automatically into the driving notch 42 (step S2). The driver edge 82 engages in the undercut 43, so that a non-rotatable connection is created between the installation spindle 62 and the wire thread insert 1 in the screw-in direction R. The non-rotatable connection ensures that the wire thread insert 1 is rotated along with a rotation of the installation spindle 62 and in this way can be installed in an internal thread of a component opening of a component. The driver edge 82 is preferably arranged offset radially inward relative to a core radius r _{K of} the length-reduced first thread turn 72a. The core radius r _K is in the Figures 4 and 5 shown. It is defined by the distance between the central axis of the installation spindle 62 and the radially outer edge of the thread core or the bottom of the thread turn 72a, 72b. The driver edge 82 is preferably spaced from the central axis of the installation spindle 62 by the length l _MK . The length l _MK preferably comprises a range of r _K > l _MK 1.4 r _K , in order to ensure an optimal interaction of the driver notch 42 and the driver edge 82.

As soon as the driving edge 82 engages in the driving notch 42 of the wire thread insert 1, the installation spindle 62 rotates the wire thread insert 1 with it. While the wire thread insert 1 is being screwed into a component opening (step S3), the driver edge 82 pulls the wire thread insert 1 in the screwing direction R due to the non-rotatable engagement on the undercut 43. The first turn 32, which adjoins the driver pin 50, lies against the length-reduced one first thread 72a and forms an additional frictional connection with it. This frictional connection supports the transmission of the installing torque from the installation spindle 62 to the wire thread insert 1. Because the installing torque to be transmitted to the wire thread insert 1 is thereby distributed to the driver edge 82 and the reduced-length first thread 72a. It is therefore preferred to set the length of the length-reduced first thread turn 72a (see angle β, above) as a function of the torque to be transmitted. It follows from this that with a larger torque to be transmitted between installation spindle 62 and wire thread insert 1, the length-reduced first thread turn 72a is formed longer than with a smaller torque to be transmitted.

The driver edge 82 is preferably formed by a radially inner and a radially outer leg. These two legs enclose an angle of <90 °, preferably <50 ° and further preferably <40 °. It is also preferred that the length-reduced first thread turn 72a terminates in an axial web which, due to its width, forms the driver edge 82.

The length-reduced first thread turn 72a ends at its end facing away from the screw-in direction R in a bend-up shoulder. The bent-up shoulder 84 consists of a surface (not shown) which is straight at an angle relative to the core radius r _K or of a curvilinear surface. The bend-up shoulder 84 forms an axial boundary surface 85 of the extension 80. The bend-up shoulder 84 preferably forms an angle δ <90 °, preferably 90 °>δ> 30 °, with the outer edge of the installation spindle 62. If the bend-up shoulder 84 consists of a curvilinear surface, the angle δ between the tangent T _δ on the surface 85 at the point of intersection with the outer edge of the installation spindle 62 and the outer edge of the installation spindle 62 is measured (see FIG Figures 4 and 5 ). Furthermore, the bent-up shoulder 84 is preferably designed to be curvilinear. The curvilinearly shaped bent shoulder 84 has related an increasing curvature on the installation spindle 62 as it extends radially inward.

According to a further preferred embodiment, the bend-up shoulder 84 is integrally connected via the reduced-length thread 72a and directly to the driving edge 82. In this way, the extension 85 is stable and forms a supplementary radial support for the length-reduced first thread 72a.

After the wire thread insert 1 has been screwed sufficiently deep into the component opening with a thread, the installation spindle 62 is rotated counter to the screwing direction R (step S4). The engagement of the driving edge 82 is released from the driving notch 42. With further rotation of the installation spindle 62 and thus the functional end 70, the bending shoulder 84 comes into contact with the driving pin 50. As the functional end 70 continues to rotate against the direction of rotation R, the bending shoulder 84 presses the driving pin 50 radially outwards into the circumferential contour of the wire thread insert 1. The driving pin 50 slides on the axial surface 85 of the bend-up shoulder 84. During the bending back of the driving pin 50 (step S5), the bending area 40 is mechanically stressed in such a way that the driving pin 50 remains in the circumferential contour of the wire thread insert 1 is bent back. Thus, when the installation spindle 62 is spindled or unscrewed from the wire thread insert 1, the bend-up shoulder 84 bends the driver pin 50, weakened by the driver notch 42, radially back into the internal thread of the component opening. The driving pin 50 is thereby permanent and is bent radially outward beyond the envelope contour of a screw and a thread plug gauge. The screwing-in torque of a screw into the wire thread insert 1 with the driver pin 50 bent back is approximately zero. The accuracy of the gauge of the wire thread insert 1 with the bent back pin 50 achieved in this way means that the bent back pin 50 does not interfere with the thread predetermined by the wire thread insert 1. The proof of such a gauge accuracy is carried out according to tolerance class 6H, according to which the gauge mandrel is screwed manually into the installed wire thread insert 1 with the pin 50 bent back. (See also ISO standard 965-1)

A preferred embodiment of the second alternative of the installation tool is shown schematically in FIG Fig. 7 shown. In contrast to the first alternative of the installation tool, it has a different functional end 70 '. The preferred functional end 70 'comprises a first 90 and a second threaded area 92, which are arranged adjacent to the free end of the functional end 70 ′ opposite the drive end 64. Preferably, both threaded areas 90, 92 directly adjoin one another in order to ensure a smooth transition of the wire thread insert 1 between the threaded areas 90, 92 when screwing on and unscrewing from the functional end 70 '. It is also preferred to arrange the two threaded areas 90, 92 axially spaced from one another on the functional end 70 '.

A thread matching the shape of the wire helix of the wire thread insert 1 is provided in the second thread region 92. This thread of the second thread area 92 has the same properties as the thread 72b of the functional end 70 (see above). Due to the shape and size of the thread adapted to the wire thread insert 1, the wire thread insert 1 can easily run into the second thread region 92. The second thread region 92 can be characterized by a core radius r _K2 , as shown in FIG Fig. 7 is shown. The core radius r _K2 defines the distance between the longitudinal axis of the functional end 70 ′ and the radial outer side of the thread core of the second thread region 92.

How to use the Figures 7 and 8 As can be seen, a thread core of the first thread area 90 is larger than the thread core of the second thread area 92. In particular, the core radius r _{K1 of} the first thread area 90 is greater than the core radius r _{K2 of} the second thread area 92. The core radius r _K1 is preferably by the factor F larger than the core radius r _K2 , so that r _K1 = F r _K2 . The factor F preferably varies in the range of 1/1000 F 5/100, more preferably in the range 1/100 F 3/100 and most preferably in the range of 2/1000 F 2/100. Accordingly, it results that the first core diameter 2r _{K1 is} at least 0.1% larger than the second core diameter 2r _K2 , preferably in a range of 0.1% to 2% larger than the first core diameter 2r _K1 .

The first thread area 90 or the thread of the first thread area 90 extends at least over an angle of rotation ω ≥ 180 ° around the longitudinal axis of the built-in spindle 62. This angle ω is measured counterclockwise or clockwise according to the direction of rotation of the first threaded area 90. The first thread region 90 preferably extends over an angle of rotation in the range of 180 ° ω 720 °.

The second threaded region 92 has a radial recess 94 into which the driver notch 42 engages with an undercut 43. Since the driver pin 50 is bent radially inward, the driver notch 42 engages in the recess 94 when the wire thread insert 1 is spindled onto the functional end 70 ′ due to its inherent spring tension. Since the recess 94 is preferably beveled, a non-rotatable connection is created in the screwing-in direction R between the functional end 70 ′ and the wire thread insert 1.

The radial recess 94 is preferably designed as a bore, milled or countersink. In addition, it is preferred to extend the recess 94 along the thread of the second threaded region 92 over a certain length. According to one embodiment of the present invention, this length corresponds to the length of the driver pin 50 so that it is more easily held in the recess 94 in a rotationally fixed manner.

While the recess 94 is preferably arranged in the second threaded area 92, it could also be arranged in the first threaded area 90, as in FIG Fig. 7 shown.

To install the wire thread insert 1 in a component opening with an internal thread, the wire thread insert 1 is spindled or screwed onto the functional end 70 '. This is done manually or automatically. Since the wire thread insert 1 can expand radially when it is spindled, because it is not restricted by a component wall, the wire thread insert 1 is spindled onto the first 90 and second thread area 92 without any particular mechanical effort (step S1). At the end of the spindling, the driving pin 50 and / or the driving notch 42 are connected in a rotationally fixed manner to the recess 94 and therefore to the functional end 70 '(step S2).

The wire thread insert is then screwed into the desired depth of the internal thread of the component opening with the aid of the installation spindle 62 (step S3). To unscrew the wire thread insert 1 from the installation spindle 62, the installation spindle 62 is rotated counter to the screwing-in direction R (step S3). In doing so, first the second thread area 92 and then the first thread area 90 are unscrewed from the wire thread insert 1, the first thread area 90 running through the entire wire thread insert 1.

During the unscrewing or unscrewing (step S4), the driving notch 42 is first pressed radially out of the recess 94. As soon as the first threaded area 90 is the driving pin 50, the larger core radius r _K1 forces the driving pin 50 radially outward in such a way that it is permanently bent back into the internal thread of the component opening or the circumferential contour of the wire thread insert 1 (step S5). Since the driving notch 42 preferably represents a weakening of the bending area 40 of the wire thread insert 1, this supports the bending back of the driving pin 50.

Due to the enlarged core diameter or core radius r _{K1 of} the first threaded area 90, the driving pin 50 experiences, in addition to the radially outwardly directed bending force, an additional tangential force introduction via the friction of the driving pin 50 on the radial outside of the two threaded areas 90, 92, in particular through the threaded area 90 . Because of this friction-related additional introduction of force, a multi-axis mechanical stress state is preferably established in the bending area 40. This causes the material yield point to be exceeded in the bending area 40, so that a permanent radial bending back of the driver pin 50 can be realized. Therefore, the driving pin 50 can be permanently bent radially outward beyond the envelope contour of a screw and a thread plug gauge and can be calibrated there. The screwing-in torque for a driving pin 50 bent back in this way and the wire thread insert 1 thus arranged in the component opening is almost zero. Proof of compliance with the gauge is preferably carried out by screwing in a plug gauge with manual force in accordance with tolerance class 6H (see also ISO standard 965-1).

The individual steps of the installation method for the wire thread insert 1 in the component opening are shown schematically according to a preferred embodiment in the flow chart of FIG Fig. 9 summarized.

List of reference symbols

1

Wire thread insert

20th

Helix

22nd

first end

23

second end

30th

Twist

40

Bending area

42

Notch

43

Undercut

50

Driving pin

60; 60 '

Installation tool

62

Installation spindle

70; 70 '

End of function

72

Threaded section

72a

first thread with reduced length

72

second thread

73

breakthrough

74

Recording area

80

frontal process

82

Driving edge

84

Bending shoulder

85

axial boundary surface of the shoulders

90

first thread area

92

second thread area

94

deepening

r _K1 , r _K2

Core radius

R.

Direction of rotation of the installation spindle into the wire thread insert

B.

Mounting direction of the wire thread insert on the functional end

S.

Arc length

r _K

Core radius

α

Angle in the wire thread insert

β

Angle of the reduced-length first thread region 72a

γ

Breakthrough angle 73

Claims (12)

1. An installation tool (60) for a wire thread insert (1) having a cylindrical coil (20) with a plurality of helically wound windings (30) of a wire, in which a first winding (32) comprises a driving tang (50) with moving notch (42) protruding into an interior of the coil (20) via a bending portion (40), wherein the installation tool (60) comprises the following features:

   a. a rotatable mounting spindle (62) with a driving end (64) for rotating the mounting spindle (62) and a functional end (70; 70') for installation of the wire thread insert (1), wherein

   b. the functional end (70) comprises at least one turn (72a) which is reduced in length in circumferential direction and which has a driving edge (82) at a first end for engagement into a moving notch (42) of the wire thread insert (1) and a bend-up-shoulder (84) at a second end for bending the driving tang (50) of the wire thread insert (1) radially outwardly.
2. Installation tool (60) according to claim 1, in which the at least one length-reduced turn (72a) has a length in circumferential direction which extends over a rotation angle of ≤ 270°, preferably ≤ 180°, around a longitudinal axis of the mounting spindle (62).
3. Installation tool (60) according to one of the preceding claims, in which the driving edge (82) is formed by a radial inner and a radial outer leg which enclose an angle < 90°.
4. Installation tool (60) according to claim 3, in which the bend-up-shoulder (84) comprises a web inclined radially inwardly and opposite to a drive-in direction R of the mounting spindle (62) which encloses with a radial outer edge of the mounting spindle (62) an angle δ < 90°.
5. Installation tool (60) according to claim 4, in which the bend-up-shoulder (84) is formed curvilinear, having with respect to the installation spindle (62) in its course radially inwardly an increasing curvature.
6. Installation tool (60) according to one of the preceding claims, in which the bend-up-shoulder (84) is connected integrally to the driving edge (82) by means of the length-reduced turn (72a).
7. An installation tool (60') for a wire thread insert (1) having a cylindrical coil (20) with a plurality of helically wound windings (30) of a wire in which a first winding (32) comprises a driving tang (50) with moving notch (42) protruding into an interior of the coil (20) via a bending portion (40), wherein the installation tool (60') comprises the following features:

   a. a rotatable mounting spindle with a driving end (64) for rotating the mounting spindle and with a functional end (70') for installation of the wire thread insert (1), in which

   b. the functional end (70') comprises a first threaded portion (90) having a first core diameter (r_k1) and a second threaded portion (92) having a second core diameter (r_k2), wherein the second threaded portion (92) is arranged between the driving end (64) and the first threaded portion (90), wherein the first core diameter (r_k1) is larger than the second core diameter (r_k2), and wherein

   c. the functional end (70') comprises a recess (94) in a turn, wherein the recess forms an undercut for the driving tang (50) of the wire thread insert (1) in drive-in direction.
8. Installation tool (60') according to claim 7, in which the recess (94) is arranged in the second threaded portion (92), preferably within a rotation angle of 270° adjacent to the first threaded portion (90).
9. Installation tool (60') according to one of the claims 7 and 8, in which the first core diameter (r_k1) is at least 0.1 % > than the second core diameter (r_k2), preferably in a range of 0.1 % to 2 % larger than the second core diameter (r_k2).
10. Installation tool (60') according to one of the preceding claims 7 to 9, in which the first threaded portion (90) extends over a rotation angle of at least 180° around the longitudinal axis of the mounting spindle.
11. Installation method of a wire thread insert (1) with redressable, not removable driving tang (50) and a moving notch (42) by means of an installation tool (60; 60') according to one of the preceding claims in a receiving thread (A) of a component (B), which comprises the following steps:

    a. spindling or plugging the wire thread insert (1) onto a functional end (70; 70') of a mounting spindle (62) of the installation tool (60; 60') such that the moving notch (42) couples in a form-fit manner to a driving edge (82) or a radial recess (94) of the installation tool (60; 60') and connects the wire thread insert (1) rotation-proof with the installation tool (60; 60'),

    b. screwing-in of the wire thread insert (1) into the receiving thread (A) by rotating the mounting spindle (62) in a first rotation direction,

    c. redressing the driving tang (50) into the receiving thread (A) by rotating the mounting spindle (62) in a second rotation direction and

    d. de-spindling or removing the mounting spindle (62) from the wire thread insert (1) with redressed driving tang (50).
12. Installation method according to claim 11, which comprises further:
    radially redressing the driving tang (50) by means of a bend-up-shoulder (84) or a first threaded portion (90) with enlarged core diameter (r_k1) compared to a second threaded portion (92) at the functional end (70; 70') of the mounting spindle (62).

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