EP2608909B1 - Method and tool for setting blind rivet elements - Google Patents

Description

The invention relates to a method for setting blind rivet elements according to the preamble of claim 1 or 2 and to a setting tool for processing or setting of blind rivet elements according to the preamble of claim 11.

Blind rivet elements according to the invention are primarily blind rivet nuts, but also other commonly used Blindnietelemente, such as. Blind rivets and blind rivet bolts.

Setting of blind rivet elements in the sense of the invention means fixing the respective, e.g. in a Vorlochung a workpiece inserted Blindnietelementes by riveting, i. by forming a Nietbundes by applying a tensile force on a tension element, for example via a mandrel to a region or an end of the Blindnietelementes, which is the Nietflansch of Blindnietelementes located on which the Blindnietelement is supported when setting on a tool system. The formation of the rivet collar takes place by permanent deformation of a rivet element section. With the rivet collar the Blindnietelement is particularly fixed against squeezing and / or against rotation in the workpiece.

The setting of Blindnietelementen in the form of blind rivet nuts, for example, with the so-called spin-pull process, in which the respective blind rivet nut screwed with its formed on one end of the Blindnietmutterkörpers nut or internal thread on the external thread of a mandrel, that is spindled and fixing the Blind rivet nut inserted into a pre-punching of a workpiece by pulling the mandrel while simultaneously supporting the blind rivet nut with its blind rivet nut or rivet flange remote from the female thread on the tooling, namely deforming the rivet collar from a portion of the rivet nut body not received in the pre-punching. The pulling of the mandrel is either up to a predetermined tensile force or reaching a predetermined example by at least one stop pulling path (setting stroke). Upon reaching the complete Setting stroke or the pulling force of the mandrel is unscrewed from the internal thread of the set blind rivet nut.

A common cause of poor setting of blind rivet nuts in workpieces is in manual processing, but also in automatic processing in that the mandrel is not completely screwed into the respective blind rivet nut, i. only an incomplete Aufspindelung the blind rivet nut is present on the mandrel, in such a way that the blind rivet or the Nietflansch of the tool system have a predetermined tolerance exceeding axial distance and / or the mandrel with its thread only in a partial length of the internal thread of the Blind rivet nut is added. During the setting process, i. When pulling the mandrel, this results in a first advance, which takes place without deforming the Blindnietmutterkörpers and in which the blind rivet nut is brought only to rest against the tool system. If the maximum stroke of the pulling spindle is predetermined, for example, by at least one stop, the actual setting stroke available for setting is reduced by this preliminary stroke, with the result that the actual setting stroke or the actual pulling path is not sufficient for proper formation of the rivet collar is sufficient. Furthermore, the improper or incomplete spindling of the respective blind rivet nut on the mandrel has the disadvantage that the latter engages only with a reduced axial length in the internal thread of the blind rivet nut and therefore there is a tearing or damage to this internal thread, namely in particular, even if the maximum stroke or pull of the mandrel is not limited by stops, but the setting process is controlled by the force exerted on the respective blind rivet nut pulling force.

The same or similar problems also occur when setting other blind rivet, which in turn rivets with their Nietflansch against a tool system fitting by the tensile force exerted by a pulling element of Blindnietwerkzeugs on a tensile or rivet mandrel of Blindnietelementes, forming a Nietbundes in the workpiece be fixed. Again, it comes with an improper arrangement of the respective rivet on the Blindnietwerkzeug, ie at a predetermined tolerance range exceeding distance between the rivet flange and the tool system at least to an incomplete training of Nietbundes.

Known is a method for setting blind rivets in workpieces ( US 2007/0033788 A1 ), wherein the setting of the respective blind rivet introduced into a pre-punching of the workpiece and the formation of a rivet collar in a setting stroke by permanent deformation of a portion of the blind rivet by applying a blind rivet end with a pulling force by a pulling element of a setting tool, while supporting a another blind rivet end on a tooling of the setting tool. Here, the course of the pulling force is monitored in dependence on the path of the drawing element. This course is also dependent on the state of the arrangement of the respective blind rivet on the setting tool at the beginning of the training of Nietbundes. If the course of the pulling force does not lie within a predetermined range depending on the path of the pulling element, a faulty setting of the blind rivet is displayed.

Not properly set blind rivet elements must be removed and / or repaired in a complex process so far.

The object of the invention is to provide a method which avoids the aforementioned disadvantages and in which already in advance, i. before the actual setting of the setting process then stopped or stopped or a correction of the setting stroke then takes place when the respective Blindnietelement is not properly arranged on Blindnietwerkzeug, i. Having a predetermined tolerance range exceeding distance from the tool system.

To solve this problem, a method according to claim 1 or 2 is formed. A Blindniet- or setting tool is the subject of claim 11.

A special feature of this Blindnietwerkzeugs is that the respective setting stroke is adjustable, preferably continuously and / or for example by a motor-actuated end stop. This design has the fundamental advantage that with one and the same riveting or setting tool different Blindnietelemente, in particular can be processed at different workpiece or sheet thicknesses. Preferably, the setting stroke is programmably adjustable.

Further developments, advantages and applications of the invention will become apparent from the following description of exemplary embodiments and from the figures.

Fig. 1

in schematischer Darstellung ein aus einem Flachmaterial, beispielsweise aus einem metallischen Flachmaterial oder Metallblech hergestelltes Werkstück zusammen mit einer Blindnietmutter im Ausgangszustand sowie im vernieteten bzw. gesetzten Zustand;

Fig. 2

in vergrößerter schematischer Teildarstellung die in das Werkstück eingesetzte Blindnietmutter zusammen mit dem Ziehdorn und der Werkzeuganlage eines Blindniet- oder Setzwerkzeugs für das Spin-Pull-Verfahren;

Fig. 3

in schematischer Funktionsdarstellung das Setzwerkzeug zusammen mit einer Überwachungs- und Steuerelektronik.

The invention will be explained in more detail below with reference to the figures of embodiments for the setting of blind rivet nuts. Show it:

Fig. 1

a schematic representation of a flat material, such as a metallic sheet or metal sheet produced workpiece together with a blind rivet nut in the initial state and in the riveted or set state;

Fig. 2

in an enlarged schematic partial representation of the blind rivet nut inserted into the workpiece together with the drawing mandrel and the tool system of a blind riveting or setting tool for the spin-pull method;

Fig. 3

in a schematic functional representation of the setting tool together with a monitoring and control electronics.

In the figures, 1 is a made of a flat material, for example of a metallic sheet material, for example made of sheet steel or aluminum sheet workpiece with a pre-perforation 2. In the pre-perforation 2 is a blind rivet nut 3 is inserted in the FIG. 1 left in its not yet deformed state, which it has immediately after insertion or -before in the pre-perforation 2, and in the FIG. 1 is reproduced on the right in its deformed or riveted or set state. The blind rivet nut 3 made of a metallic material, for example made of steel or aluminum, consists essentially of a sleeve-like Blindnietmutterkörper 4 with a continuous, coaxially arranged with the axis BA of the blind rivet nut 3 opening 5 and with a on the outer surface of the Blind rivet body 4 radially projecting Nietflansch 6 at the in the FIG. 1 The sleeve-like Blindnietmutkörper 4 formed in a circular cylindrical shape, for example on the outer and inner surfaces, essentially forms two sections, namely the section 4.1, which is remote from the flange 6 and at which the opening 5 is provided with a female or female thread 7. and the section 4.2, which merges into the Nietflansch 6 and in which the opening 5 is formed threadless and with an enlarged cross-section. In the riveted or set state, the blind rivet nut 3 rests with its rivet flange 6 against the one side of the workpiece 1.1 of the workpiece 1, which in the representation of FIG. 1 the top is, and the not recorded in the pre-perforation 2 section 4.2 is in the in the FIG. 1 shown right to a the axis BA annularly enclosing bead-like rivet collar 8 permanently deformed, which bears against the other side of the workpiece 1.2 pressed so that the blind rivet nut 3 secured the workpiece 1 in the pre-perforation encompassing against squeezing and turning or twisting in the workpiece 1 is. Since the wall thickness of the blind rivet nut body 4 is reduced in the section 4.2, the defined deformation of the blind rivet nut body 4 into the rivet collar 8 takes place in this area not received in the pre-perforation 2.

The setting of the respective blind rivet nut takes place with a setting tool, generally designated 9 in the figures. The setting tool 9 includes, inter alia, a drawing mandrel 11 provided with a thread 10 at a free end and a mandrel 11 enclosing the mandrel 11 Tool head 12, which forms a mandrel 11 also enclosing annular system 13.

In detail, the setting of the respective blind rivet nut 3 takes place by the spin-pull method in such a way that the blind rivet nut 3, which is provided at a delivery position (not shown), is arranged by rotating the axis-like axis BA and inserted into the opening 5 from the rivet flange 6 Ziehdorns 11 with the internal thread 7 is screwed or spindled onto the thread 10 of the mandrel 11, in such a way that the blind rivet nut 3 finally in an ideal manner with the side facing away from the thread 7 Blindnietmutterkörpers 4 or with the Nietflansches 6 against the plant 13 of the tool body 12 abuts. Held in this form on the setting tool 9, the blind rivet nut 3 is inserted into the pre-perforation 2 such that the rivet flange 6 rests against the workpiece side 1.1. The turning of the mandrel 11 during spindling is done by a rotary drive in the FIG. 3 is shown schematically at 14. After inserting the blind rivet nut 3 in the workpiece 1, the setting is carried out by relative movement between the mandrel 11 and the tool head 12, in such a way that when fitting against the Nietflansch 6 tool head 12, a tensile force on the mandrel 11 on the threaded 7 exposed end of the Blindnietmutterkörpers 4 exerted and thereby the section 4.2 is deformed into the Nietbund 8.

Due to tolerances and due to the deformability of the blind rivet nut 3 and / or the workpiece 1, a relative movement between the pull mandrel 11 and the tool body 12 or the tool system 13 is often in the form of the rivet collar 8 before the actual setting or deformation of the section 4.2 a small advance stroke VH. The required relative to the setting of the blind rivet nut 3 relative movement between the mandrel 11 and the tool body 12 and the system 13 (Setzhub SH) is achieved for example by acting between these tool parts drive, for example in the form of at least one piston-cylinder assembly or a hydraulic cylinder, the Indian FIG. 3 is indicated schematically with 15.

In order to ensure proper formation of the rivet collar 8 and in particular to avoid tearing of the internal thread 7 by excessively high, exerted by the mandrel 11 when setting tensile forces, it is common to the path of Setzhubes SH and / or exercised by the mandrel 11 Traction to limit to a predetermined value. In particular, when the drive 15 is formed by at least one piston-cylinder arrangement, for example by a hydraulic cylinder, the maximum setting stroke SH is predetermined by corresponding stops.

In a manual processing of the blind rivet nuts 3, in which the respective setting tool 9 is designed as a hand-operated tool, but also in a machine processing of blind rivet nuts 3, in the (processing) the setting tool 9 is part of a manufacturing plant or a workstation such a system can It can not be ruled out that blind rivet nuts 3 are partially spindled onto the drawing mandrel 11 so that they are still spaced from the tooling 13 with their rivet flange 6.

If the distance between the rivet flange 6 and the tool system 13 is greater than a predetermined tolerance range after being spindled, the result is an increased forward stroke VH and thus a reduction of the setting stroke SH available for setting.

• ein Sensor 18, der den Weg der Relativbewegung zwischen dem Ziehdorn 11 und dem Werkzeugkörper 12 erfasst und ein von diesem Weg abhängiges Messsignal an den Prozessor 17 liefert;
• ein Drucksensor 19, der zur Erfassung des an dem Antrieb 15 bzw. in einem dortigen Zylinderraum anstehenden Hydraulikdrucks dient und ein entsprechendes Messsignal an den Prozessor 17 liefert;
• eine Steuerventilanordnung 20, die von dem Prozessor 17 angesteuert wird, und zwar zur Steuerung des Antriebes 15 bzw. zur Steuerung des diesem Antrieb über eine Leitung 21 zugeführten pneumatischen oder hydraulischen Druckmedium, z.B. Hydraulik-Öl;
• eine Schnittsteilenanordnung 22, über die die Datenübertragung zwischen dem Prozessor 17 und den Sensoren 18 sowie 19 und der Steuerventilanordnung 20 erfolgt und die auch einen externen Anschluss für einen Datenverkehr mit anderen peripheren Geräten und/oder zur Ansteuerung weiterer Funktionseinheiten des Setzwerkzeugs 9 oder einer dieses Setzwerkzeug aufweisenden Anlage dient.

The insufficient spindling of the blind rivet nut 3 on the mandrel 11 or on the local thread 10 and the resulting increased advance stroke VH then lead to the rivet collar 8 is not formed properly and thus the anchoring of the blind rivet nut 3 in the workpiece 1 is deficient. Furthermore, the insufficient spindling of the blind rivet nut 3 on the drawing mandrel 11 causes the thread 10 to engage only over a shortened axial length in the internal thread 7 and this tears when pulling or deformation of the section 4.2. Such, not properly set blind rivet nut 3 must be removed in a complex repair process from the workpiece 1 and replaced by a properly set Blindnietmutter 3 according to the usual procedure. This disadvantage is with the in the FIG. 3 shown, the setting tool 9 associated monitoring and control electronics 16 with processor 17 avoided, which are assigned, inter alia:

• a sensor 18 which detects the path of relative movement between the mandrel 11 and the tool body 12 and provides a measurement signal dependent on this path to the processor 17;
• a pressure sensor 19, which serves to detect the hydraulic pressure applied to the drive 15 or in a cylinder chamber there and supplies a corresponding measurement signal to the processor 17;
• a control valve assembly 20, which is controlled by the processor 17, namely for controlling the drive 15 and for controlling the said drive via a line 21 fed pneumatic or hydraulic pressure medium, such as hydraulic oil;
• a sectional part arrangement 22, via which the data transmission between the processor 17 and the sensors 18 and 19 and the control valve assembly 20 takes place and which also has an external connection for data traffic with other peripheral devices and / or for controlling further functional units of the setting tool 9 or a setting tool serving plant serves.

With the monitoring and control device 16 3 different methods are possible by detecting the state of the Aufspindelung the respective blind rivet nut, which prevent improper setting of the respective blind rivet nut 3, for example, either by stopping or aborting the setting process or by correcting the size the setting stroke SH and / or the pulling force exerted on the pulling mandrel 11 during setting as a function of the detected preliminary stroke VH. This can then for example be detected or detected directly by the sensor 18, or indirectly, for example by the fact that the drive 15 or the at least one piston-cylinder arrangement forming this drive once or in succession several times by briefly opening the Control valve assembly 20 is acted upon by the standing under a high working pressure pressure medium or hydraulic oil and then measured in each case with the pressure sensor 19 of the pressure applied to the drive 15 and from this the size of the Vorhubes VH in the processor 17 is determined.

1. 1. Nach dem Einsetzen der jeweiligen Blindnietmutter 3 in die Vorlochung 2 wird beim Auslösen des Setzvorgangs bzw. in einer Dedektierphase zunächst über den Antrieb 15 eine Zugkraft auf den Ziehdorn 11 ausgeübt, die soweit reduziert ist, dass sie noch kein Verformen der Blindnietmutter 3 erzeugt. Ist die Blindnietmutter 3 nur unzureichend auf den Ziehdorn 11 aufgespindelt, so ergibt sich ein vergrößerter Vorhub VH in Form einer Relativbewegung zwischen dem Ziehdorn 11 und dem Werkzeugkopf 12, die (Relativbewegung) von dem Sensor 18 erfasst wird. Überschreitet die Relativbewegung bzw. der Vorhub VH einen vorgegebenen Toleranzbereich, so wird der Setzprozess gestoppt, bevor es zu einem Verformen der Blindnietmutter 3 bzw. zu einer Ausbildung eines unzureichenden Nietbundes 8 kommt. Die Blindnietmutter 3 wird dann entweder in einem Nachverfahren ordnungsgemäß auf den Ziehdorn 11 aufgespindelt oder aber durch eine andere, auf den Ziehdorn 11 ordnungsgemäß aufgespindelte Blindnietmutter 3 ersetzt. Zur Realisierung dieser Arbeitsweise ist lediglich der Wegmesssensor 18 oder ein entsprechendes Wegmesssystem erforderlich.
2. 2. Weiterhin besteht die Möglichkeit, den Sensor 18 als Schalter oder Mikroschalter auszubilden, der dann betätigt wird, wenn nach dem Auslösen des zunächst mit geringer Kraft eingeleiteten Setzvorgangs aufgrund des Abstandes zwischen dem Nietflansch 6 einer nur unzureichend aufgespindelten Blindnietmutter 3 und der Werkzeuganlage 13 die Relativbewegung zwischen den Ziehdorn 11 und den Werkzeugkörper 12, d.h. der Vorhub VH einen Wert überschreitet, der außerhalb eines zulässigen Tolleranzbereichs liegt. Nach dem Ansprechen des Schalters wird wiederum der Setzprozess gestoppt. Die Ausbildung des Sensors 18 als Schalter hat den besonderen Vorteil, dass über diesen Schalter unmittelbar das Stoppen des Setzprozesses veranlasst werden kann, also eine rein mechanische, pneumatische oder hydraulische Steuerung ohne Elektronik, d.h. ohne den Prozessor 17 möglich ist.
3. 3. Weiterhin besteht die Möglichkeit, den Ziehdorn 11 bzw. den Antrieb 15 für eine kurze definierte Zeit mit der vollen Kraft bzw. mit dem vollen an der Leitung 21 anstehenden Druck des Druckmediums zu beaufschlagen, und zwar bis zum Erreichen eines vorgegebenen, mit dem Drucksensor 19 überwachten Druckes, der nicht ausreicht, um die in die Vorlochung 2 eingesetzte Blindnietmutter 3 zu verformen bzw. einen Nietbund 8 auszubilden. Der innerhalb dieser Zeit sich ergebende Weg der Relativbewegung zwischen dem Ziehdorn 11 und dem Werkzeugkopf 12 wird wiederum ermittelt und bildet ein Maß für das nicht vollständige Aufspindeln der Blindnietmutter 3 bzw. für den axialen Abstand zwischen dem Nietflansch 6 und der Werkzeuganlage 13. Zur Drucküberwachung dient beispielsweise der Drucksensor 19 oder aber eine Kraftdose oder ein Dehnungsmessstreifen. Der Weg wird wiederum durch den Sensor 18 ermittelt, auch andere analoge oder digitale Wegmesssysteme oder ein oder mehrere elektrische Schalter, beispielsweise Mikroschalter können zur Detektierung der Relativbewegung zwischen dem Ziehdorn 11 und dem Werkzeugkörper 12 bzw. zur Detektierung des Vorhubes VH verwendet werden. Übersteigt dieser Vorhubes VH einen vorgegebenen Toleranzbereich, so erfolgt wiederum ein Stoppen des Setzprozesses.
4. 4. Vorstehend wurde davon ausgegangen, dass in Abhängigkeit von dem unmittelbar oder mittelbar in einer Dedektierphase detektierten Vorhub VH der Setzvorgang ausgeführt (Vorhub VH innerhalb eines vorgegebenen Toleranzbereichs) oder abgebrochen wird (VH außerhalb eines vorgegebenen Toleranzbereichs). Grundsätzlich besteht auch die Möglichkeit, den Setzhub SH in Abhängigkeit von dem detektierten Vorhub VH zu korrigieren, d.h. zu vergrößern, beispielsweise in der Form, dass der tatsächlich durchgeführte korrigierte Setzhub SH die Summe aus dem detektierten Vorhub VH und einen vorbestimmten Setzhub ist, der durch die Art der verwendeten Blindnietmuttern 3 sowie insbesondere auch durch die Dicke des jeweiligen Werkstücks 1 definiert ist. Sind die Größe oder der maximale Weg der mit dem Antrieb 15 erzeugten Relativbewegung zwischen dem Ziehdorn 11 und dem Werkzeugkörper 12 durch Anschläge bestimmt, so erfolgt die Korrektur des Setzhubes beispielsweise durch ein motorisches Verstellen dieser Anschläge. Weiterhin kann die Korrektur des Setzhubes SH auch dadurch erfolgen, dass die Relativbewegung zwischen dem Dorn 11 und dem Werkzeugkörper 12 ständig mit dem Sensor 18 oder einer anderen Wegmesseinrichtung überwacht und/oder der Druck des Druckmediums und damit die Ziehkraft des Ziehdorns 11 mit dem Sensor 19 ständig überwacht werden und nach Erreichen vorgegebener, dem korrigierten Setzhub entsprechender Werte ein sofortiges Abschalten des Antriebs 15 durch den Prozessor 19, beispielsweise durch Sperren der Steuerventilanordnung 20 erfolgt. Vorraussetzung, aber zumindest sinnvoll für dieses Verfahren ist es, dass die Korrektur des Setzhubes nur dann erfolgt, wenn der nach dem Auslösen des Setzvorgangs in der Dedektierphase zunächst detektierte Vorhub VH innerhalb eines Toleranzbereichs liegt, der sicherstellt, dass der Ziehdorn 11 mit seinem Gewinde 10 zumindest über eine solche axiale Länge in das Innengewinde 7 der Blindnietmutter 3 eingreift, die (axiale Länge) bei der für das ordnungsgemäße Formen des Nietbundes 8 erforderlichen, vom Ziehdorn 11 ausgeübten Ziehkraft ein Ausreißen des Innengewindes 7 mit Sicherheit vermeidet.

In detail, the following modes of operation are possible:

1. 1. After inserting the respective blind rivet nut 3 in the pre-perforation 2, a tensile force is exerted on the mandrel 11 when triggering the setting process or in a Dedektierphase first via the drive 15, which is reduced so far that it does not produce any deformation of the blind rivet nut 3 , If the blind rivet nut 3 is spindled only insufficiently on the drawing mandrel 11, then an increased forward stroke VH results in the form of a relative movement between the pulling mandrel 11 and the tool head 12 which is detected by the sensor 18 (relative movement). If the relative movement or the preliminary stroke VH exceeds a predetermined tolerance range, then the setting process is stopped before the blind rivet nut 3 or an insufficient rivet collar 8 is deformed. The Blind rivet nut 3 is then either spindled onto the mandrel 11 in a post-process or replaced by another blind rivet nut 3 properly spindled onto the mandrel 11. To realize this procedure, only the distance measuring sensor 18 or a corresponding displacement measuring system is required.
2. 2. Furthermore, it is possible to form the sensor 18 as a switch or micro-switch, which is then actuated when, after the initiation of the first initiated with little force setting operation due to the distance between the Nietflansch 6 an insufficiently spindled blind rivet nut 3 and the tool system 13 Relative movement between the mandrel 11 and the tool body 12, that is, the pre-stroke VH exceeds a value that is outside of a tolerable Tolleranzbereichs. After the switch has responded, the setting process is stopped again. The design of the sensor 18 as a switch has the particular advantage that the stop of the setting process can be initiated directly via this switch, ie a purely mechanical, pneumatic or hydraulic control without electronics, ie without the processor 17 is possible.
3. 3. It is also possible to apply the drawing mandrel 11 or the drive 15 for a short defined time with the full force or with the full on the line 21 pending pressure of the pressure medium, until reaching a predetermined, with the Pressure sensor 19 monitored pressure, which is not sufficient to deform the blind rivet nut 3 used in the pre-perforation 2 or form a Nietbund 8. The resulting within this time path of the relative movement between the mandrel 11 and the tool head 12 is again determined and forms a measure of the incomplete spindling of the blind rivet nut 3 and for the axial distance between the rivet flange 6 and the tool system 13. For pressure monitoring is used For example, the pressure sensor 19 or a power box or a strain gauge. The path is again determined by the sensor 18, other analog or digital Wegmesssysteme or one or more electrical switches, such as microswitches can be used to detect the relative movement between the mandrel 11 and the tool body 12 and to detect the Vorhubes VH. If this pre-stroke VH exceeds a predetermined tolerance range, the setting process is stopped again.
4. 4. It has been assumed above that, depending on the forward stroke VH detected directly or indirectly in a detection phase, the setting process is carried out (forward stroke VH within a specified tolerance range) or aborted (VH outside a specified tolerance range). Basically, it is also possible to correct the setting stroke SH as a function of the detected advance stroke VH, ie to increase, for example, in the form that the actually performed corrected setting stroke SH is the sum of the detected advance stroke VH and a predetermined setting stroke that passes through the type of blind rivet nuts 3 used and in particular also defined by the thickness of the respective workpiece 1. If the size or the maximum distance of the relative movement between the drawing mandrel 11 and the tool body 12 generated by the drive 15 is determined by stops, the correction of the setting stroke is effected, for example, by a motorized adjustment of these stops. Furthermore, the correction of the setting stroke SH can also take place in that the relative movement between the mandrel 11 and the tool body 12 is constantly monitored by the sensor 18 or another displacement measuring device and / or the pressure of the pressure medium and thus the pulling force of the pulling mandrel 11 with the sensor 19 are constantly monitored and after reaching predetermined, the corrected setting stroke corresponding values, an immediate shutdown of the drive 15 by the processor 19, for example by blocking the control valve assembly 20 takes place. Prerequisite, but at least useful for this method is that the correction of the setting stroke only takes place when the preliminary stroke VH initially detected after the initiation of the setting process in the detection phase lies within a tolerance range which ensures that the drawing mandrel 11 with its thread 10 engages at least over such an axial length in the internal thread 7 of the blind rivet nut 3, the (axial length) required in the proper shaping of the rivet collar 8, exerted by the mandrel 11 pulling force tearing of the internal thread 7 avoids security.

The invention has been described above by means of exemplary embodiments. It is understood that numerous changes and modifications are possible without thereby departing from the idea underlying the invention. All embodiments or methods have in common that detected at the beginning of the respective setting process, the state of the spindle of the respective blind rivet nut on the mandrel 11 in a Dedektierphase and then performed depending on this state of the setting process or aborted or the setting stroke is corrected.

Above, various methods for setting blind rivet nuts 3 are described. It is understood that the invention is not limited to blind rivet nuts, but completely refers generally to blind rivet, for example, on blind rivet.

LIST OF REFERENCE NUMBERS

1

workpiece

1.1, 1.2

Workpiece side

2

preliminary hole

3

blind rivet nut

4

Blindnietmutterkörper

4.1, 4.2

Section of the blind rivet body

5

Opening of the blind rivet nut

6

Flange of blind rivet nut

7

Internal thread of the blind rivet nut

8th

rivet collar

9

Tool

10

thread

11

mandrel

12

Tool head or body

13

investment

14

Drive for spindling the blind rivet nuts

15

Drive for generating an axial relative movement between the mandrel 11 and tool body 12th

16

Monitoring and control device

17

processor

18

Sensor for measuring distance, for example microswitch

19

pressure sensor

20

Control valve assembly

21

Line for hydraulic fluid or hydraulic oil under working pressure

22

Interface arrangement

BA

Blindnietmutterachse

VH

Pretravel

SH

setting stroke

Claims (11)

1. A method for setting blind rivet nuts (3) or similar blind rivet elements into workpieces (1), in which the respective blind rivet element introduced into a pre-punched hole (2) of the workpiece (1) is set or a rivet collar (8) is constructed in a setting stroke (SH) by permanent deformation of a section (4.2) of the blind rivet element (3) by applying a pulling force to a blind rivet element end (4.1) by means of a pulling element (11) of a setting tool (9) with simultaneous support of a different blind rivet element end (6) on a tool contact area (13) of the setting tool (9) counter to this pulling force, wherein the state of the arrangement of the respective blind rivet element (3) at the setting tool and/or the spacing between the blind rivet element (3) and the tool contact area (13) corresponding to this state is determined before the construction of the rivet collar (8),
   characterised in that,
   depending on the determined state, the setting process is continued in the event of correct arrangement of the blind rivet element (3) at the setting tool or, in the event of defective arrangement, the setting process is interrupted and/or the size of the setting stroke (SH) is corrected.
2. A method for setting blind rivet nuts (3) into workpieces (1), in which the respective blind rivet nut (3), which is introduced into a pre-punched hole (2) of a workpiece (1) and spindled onto a thread of a mandrel (11) of a riveting tool using an internal thread, is set in a setting stroke (SH) by applying a pulling force to the mandrel (11) whilst simultaneously supporting a blind rivet nut end (6) remote from the internal thread (7) on a tool contact area (13) of the setting tool (9), namely by the construction of a rivet collar (8) by means of the permanent deformation of a section (4.2) of the blind rivet nut (3), characterised in that the state of the spindling of the respective rivet nut (3) on the mandrel (11) and/or the distance between the blind rivet nut (3) and the tool contact area (13) corresponding to this state is determined before the construction of the rivet collar (8), and depending on this state, the setting process is continued in the event of correct spindling or, in the event of defective spindling, the setting process is interrupted and/or the size of the setting stroke (SH) is corrected.
3. The method according to claim 1 or 2, characterised in that a force is initially exerted onto the pulling element or onto the mandrel (11) in a detection phase when starting the setting process, which force is insufficient for constructing the rivet collar (8), and in that during this detection phase, the relative movement between the pulling element or mandrel (11) and the tool contact area (13) is detected as prestroke (VH), and in that the setting process is stopped or interrupted if the prestroke (VH) exceeds a predetermined tolerance range.
4. The method according to claim 3, characterised in that the prestroke (VH) is detected by a travel measurement sensor or a travel measurement system (18) and/or in that the stopping or interruption of the setting process is effected or induced by at least one electrical switch, which is activated or actuated in the event of a prestroke (VH) exceeding a predetermined tolerance range.
5. The method according to one of the preceding claims, characterised in that a pulling-element drive or mandrel drive (14) formed by at least one piston/cylinder arrangement is loaded at least once briefly with a full working pressure of a pneumatic or hydraulic pressure medium, which is also used for the setting, during the detection phase and the prestroke (VH) triggered thereby is determined, for example by means of a travel measurement sensor (18) or by means of a travel measurement system and/or by measuring the pressure that is set in the at least one piston/cylinder arrangement after the brief loading with pressure.
6. The method according to one of the preceding claims, characterised in that in the detection phase, a pulling-element drive or mandrel drive (14), preferably at least one piston/cylinder arrangement forming this drive, is loaded with the working pressure of a pneumatic or hydraulic pressure medium until a pressure or a pulling force acting on the pulling element or mandrel (11) is reached, which is below the pulling force required for constructing the rivet collar (8), and in that here the prestroke (VH) determined and preferably the pressure in the piston/cylinder arrangement forming at least one mandrel drive (14) is monitored, for example by means of at least one sensor (19) measuring the pressure of the pneumatic or hydraulic pressure medium or by means of a load cell or a strain gauge, which detects the pressure or the force between the pulling element or mandrel (11) and the tool contact area (13).
7. The method according to one of the preceding claims, characterised in that, whilst considering the prestroke (VH) determined in the detection phase, a correction of the setting stroke (SH) for setting the blind rivet element or the blind rivet nut (3) takes place, for example in the form of the size of the prestroke (VH) being added at least to some extent to an initial setting stroke, which is predetermined by the type of blind rivet nuts (3) to be processed and by the type of workpieces, particularly by the thickness of the workpieces (1).
8. The method according to claim 7, characterised in that the correction of the setting stroke (SH) takes place if the prestroke (VH) does not exceed a predetermined tolerance range, which ensures that the mandrel (11) engages into the internal thread of the blind rivet nut (3) with sufficient axial length and in that the setting process is stopped or aborted if the tolerance range is exceeded.
9. The method according to claim 6 or 7, characterised in that the correction of the setting stroke (SH) takes place by means of automatic or motive setting of at least one stop determining the size of the setting stroke.
10. The method according to one of claims 6-8, characterised in that the correction of the setting stroke (SH) takes place by means of the monitoring thereof using a travel measurement sensor or using a travel measurement system and/or by means of the monitoring of the force exerted on the pulling element or the mandrel (11) and/or the pressure of a piston/cylinder arrangement forming the pulling element drive or mandrel drive.
11. A setting tool for setting blind rivet elements (3), for example blind rivet nuts, in workpieces (1), having a pulling element (11), by which the respective blind rivet element (3), which is introduced into a pre-punched hole (2) of the workpiece (1), can be loaded at one blind rivet element end with a pulling force, with simultaneous support of a different blind rivet element end (6) on a tool contact area (13) of the setting tool (9), specifically to construct a rivet collar (8) by means of permanent deformation of the blind rivet element (3) in a setting stroke (SH) of the pulling element (11), characterised by:

    - means for determining the state of the arrangement of the respective blind rivet element (3) at the setting tool and/or the distance between the blind rivet element (3) and the tool contact area (13) corresponding to this state before the construction of the rivet collar (8); and

    - means for continuing the setting process depending on this state in the event of correct arrangement of the blind rivet element (3) on the setting tool, or for interrupting and/or correcting the size of the setting stroke (SH) in the event of defective arrangement.

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