DE102017223713A1 - Method and device for setting blind rivets or blind rivet nuts - Google Patents

Abstract

Method and device for setting blind rivets (24) consisting of rivet shank (22) and tear-off rivet mandrel (21), in which a rivet mandrel (21) is gripped, a rivet shank (22) inserted into a rivet opening (30) of a component (31) to be riveted and the gripped rivet mandrel (21) is tightened, with the steps performed during a setting process (50): - detecting setting path data corresponding to a set travel path (40); - traction data corresponding to an applied pulling force (41) In the prior art, a more process-scattering and preferably also more realistic processing of the joining process is created by performing the following routine cyclically and automatically during a current setting process (50): - detecting the pulling force (41) setting path (40) data, - transmitting the detected traction (41) -Setzweg (40) data to an evaluation device (16), - Processing the traction (41) -Setzweg (40) -Daten in the Ausw erteeinrichtung (16), - Providing at least one evaluation result for analysis and / or cyclic control and / or for cyclical monitoring of the setting process (50).

Description

The present invention relates to a method and a device for setting Blindnietelementen or blind rivet nuts according to the preamble of claim 1 and according to the preamble of claim 15 and a corresponding device according to the preamble of claim 16th

Blind riveting is a joining process using rivet elements. The sheets and components to be joined are usually pre-punched before joining. An essential advantage of blind riveting is that only one side of the joint must be accessible (one-sided accessibility). In blind riveting, the parts to be joined are not heated so that they do not warp. It can be used to bond many materials (e.g., plastic to metal, fiber reinforced plastic to fiber reinforced plastic, or metal) and has low surface finish requirements for the parts being joined. Below, the process sequence for blind riveting is detailed and the components of the blind rivet are named. Depending on the material thickness combination and the type of application, different blind rivet types are installed (for example, sleeve-folding blind rivet or sleeve-extended blind rivet for different clamping length ranges, with different diameters).

1. 1. Erfassen von mit einem zurückgelegten Setzweg korrespondierenden Setzwegdaten
2. 2. Erfassen von mit einer aufgebrachten Zugkraft korrespondierenden Zugkraftdaten.

In general, the invention relates to unilaterally settable jointing tasks, which are difficult or impossible to access from at least one side, with joining elements in which a break-off mandrel is provided for transmitting an actuating tensile force. The technical field preferably relates to partially or fully automated versions of the method according to the invention and of the device according to the invention, both by means of robotic actuation and by means of hand-held, electrically driven and controlled tools. The method for setting blind rivets or blind rivet nuts preferably uses cordless tools for manual operation. By means of these, a rivet mandrel is automatically, semi-automatically or fully automatically gripped, a rivet shank inserted into a rivet opening of a component to be riveted and the gripped rivet mandrel tightened. During this setting process, the following steps are carried out in the genus of a rivet setting device according to the invention or in the method according to the invention:

1. 1. detecting set path data corresponding to a traveled set route
2. 2. Detecting tensile force data corresponding to an applied tensile force.

From the DE 10 2013 221 792 The applicant, the content of which is fully incorporated herein, discloses a method and apparatus for setting blind rivets in which sensors for detecting a path and a pulling force are present. As a result, process data arising during the work process are made detectable for a subordinate quality control. As a result, the current process can not be responded to or only subsequently and / or restricted.

The object of the invention is to provide a process-scattering and preferably also more realistic processing of the joining process compared with the prior art and / or to increase the influence possibilities on the joining process. In particular, it is the object of the invention to improve the standard process reliability and / or joint quality prior to the invention, and in particular to make it more timely and / or more flexible, independent of the assembly or industrial automation infrastructure.

• - Erfassen der Zugkraft-Setzweg-Daten,
• - Übertragung der erfassten Zugkraft-Setzweg-Daten an eine Auswerteeinrichtung,
• - Verarbeitung der Zugkraft-Setzweg-Daten in der Auswerteeinrichtung
• - Bereitstellung zumindest eines Auswertungsresultates zur Analyse und/oder zur zyklischen Steuerung und/oder zur zyklischen Überwachung des Setzvorgangs.

The invention is characterized in that during a current, current setting process, a specific routine for acquiring and processing the acquired data is carried out cyclically and automatically, namely:

• Detecting the draft limit data,
• Transmission of the detected traction-set route data to an evaluation device,
• - Processing the traction-Setzweg-data in the evaluation
• - Provision of at least one evaluation result for analysis and / or for cyclical control and / or for cyclical monitoring of the setting process.

Cyclic may mean periodically repeating, in particular with a predetermined cycle cycle or a predetermined cycle time. The routine is preferably executed several times. In particular, the routine is set during a setting process, e.g. from the onset of traction to the rivet mandrel tear, carried out continuously.

The feature of the automated implementation comprises that - e.g. with the start of a setting process - the routine is automatically, automatically started and / or automatically, electrically controlled and performed independently of an input signal. The cyclic control and / or the cyclical monitoring preferably also take place automatically.

With the cyclical and automated acquisition of the mentioned data, real-time, process-fidelity and current parameters of the joining process are not only detected, but preferably again in real time. processed; As a result, the processing result is available during a current joining process and can be used to control and / or monitor and / or analyze the current setting process.

By means of this realistic processing of the process data, a hitherto unachievable transparency of the joining process is to be ensured and it is possible to considerably increase the previously limited influence possibilities on the joining process according to the state of the art. This can e.g. used to improve process reliability and / or joint quality. For example, safety-critical or safety-relevant process data of the current joining process can be evaluated and used for the influencing, in particular for a control and / or regulation of the joining process.

In addition, with regard to transparency and realistic, up-to-date data processing, the invention offers the possibility of designing the joining process as autonomous or semi-autonomous within the framework of an industrial assembly infrastructure or production infrastructure. Although a higher-level control infrastructure may be present, the invention offers the possibility of processing data flexibly and independently, virtually independently of such industrial automation environments, and of ensuring process reliability and / or joint quality and / or operator safety.

• - Vermeidung potentieller Verletzungsgefahr durch Fehlbedienung
• - Reduzierung der für den Bediener notwendigen Arbeitskraft (Entfall mechanischer Andrückkontrolle)
• - Aufbau Mundstück mit weniger Komponenten (mögliche Gewichteinsparung)
• - Möglichkeit das Mundstück schlanker zu gestalten
• - bessere Zugänglichkeit zum Fügepunkt
• - Realisierung schmaler Flansche
• - Rückschluss auf Gesamtbauteildicke anhand Auswertung / Analyse des Kraft-Weg-Verlaufes (z.B. wurde Niet an der Stelle mit der gewünschten Wandstärke, bzw. für den vorgesehenen Klemmbereich verbaut?)

Finally, achievable advantages of the invention (these will be discussed in more detail below):

• - Avoidance of potential injury due to incorrect operation
• - Reduction of the labor force necessary for the operator (elimination of mechanical pressure control)
• - Construction mouthpiece with fewer components (possible weight savings)
• - Possibility to make the mouthpiece slimmer
• - better accessibility to the joining point
• - Realization of narrow flanges
• - Conclusion on total component thickness based on evaluation / analysis of the force-displacement curve (eg was rivet installed at the position with the desired wall thickness or for the intended clamping area?)

The determination of the tensile force-Setzweg data takes place by means of the invention provided; These may be, for example, force sensors or displacement sensors. These sensors can be realized in an electric drive, for example by an angle sensor on the engine whose signals are converted by means of a conversion in Setzweg data. When the rotary motion of the electric motor is converted to linear motion by means of, for example, a ball screw, the conversion simply occurs by converting the rotation angle to the set path by means of the characteristic angular / feed path ratio of the ball screw. More generally, a conversion is carried out by converting the measured angle of rotation in Setzweg by means of a characteristic angular / Vorschubweg ratio of the involved mechatronic components.

The force evaluation can be done, for example, via a power detection of the electric motor, since the force exerted by the electric motor is essentially a clear function (for example, to play and slippage of the mechanical elements involved) of the impressed power of the electric motor. The further design possibilities of the force sensor system will be discussed in more detail below.

The traction-Setzweg-data are also cyclically and automatically transmitted to an evaluation. This can be an analogue or digital transmission. At the level of sensor technology, analogue methods of data transmission are still being used. Furthermore, digital transmission methods, such as e.g. known in the art, cyclic sensor data transmission protocols are used. Due to the cyclical transmission, a cyclical execution of the entire process according to the invention can be ensured throughout.

The transmitted to the evaluation device Zugraft-Setzweg data are processed there. The closer design of the evaluation device and the processing process will be discussed in more detail later.

It is essential that the evaluation results are provided cyclically during an ongoing, current setting process; Thus, a cyclical control of the current setting process is made possible by the invention based on the process-related recorded measurement data.

Furthermore, through the automated, cyclical provision of the evaluation result, a likewise cyclical monitoring of the setting process can take place. Thus, the invention provides an essential means for improving process reliability and ongoing quality in the current setting process.

This invention also describes a measuring hand-setting blind riveting tool (preferably with battery operation) which allows a complete riveting operation only by means of a component (until the rivet pin is torn off). If no component is present, the process is stopped prematurely via real-time evaluation of the force-displacement data so that the rivet mandrel is not torn off. Furthermore, the total thickness of the component can be detected on the basis of the force-displacement data of the riveting curve.

It is provided a measuring Blindnietsetzgerät (preferably battery-powered manual setting device) which prevents tearing of the mandrel without a component (in free space) by means of real-time evaluation of the measured force-displacement data. The mechanical pressure control used in previous devices can be replaced with the new method. This relieves the operator and simplifies the construction of the mouthpiece (saving on components). This will be discussed in more detail below.

A particularly process-faithful detection of the setting process is made possible in that the routine is carried out with a characteristic for a regular setting cycle-action time. The cycle cycle time is determined, for example, by an initial configuration in the context of an automation system or directly in the rivet setting device. The design of the characteristic cycle cycle time can be based on a regular setting process. A regular or typical setting operation in this context may be a reference operation that is usable for a variety or for all joining tasks. The basis for the cycle cycle time can be the time between the onset of traction and the rupture of the rivet mandrel. This period of time may typically be fractions of seconds, e.g. 10 to 100 or 100 to 1000 milliseconds, up to a few seconds. For the calculation of the cycle cycle time, the characteristic traction-setting path course of a regular setting process can also be used.

In addition, the cycle time can be determined in accordance with a reaction time inherent to the process, in particular safety technology and / or quality management technically required, e.g. for the reaction to safety-critical and / or quality-critical conditions. In the event of a safety or quality risk, it may be necessary to respond to a safe or high-quality process within a very short period of time, which can be measured according to the type of placement process involved, or a relevant, regular and / or typical placement process ,

Furthermore, a typical reaction time required for the process control given by the physical parameters of the setting process can be used for the dimensioning of the cycle time. This ensures that it is possible to intervene in the process in a timely manner within the time requirements imposed by a typical setting process.

A multiplicity or even all typical joining processes can be covered within the meaning of the invention with regard to safety-critical and / or quality-critical properties if the cycle time is less than or equal to a maximum cycle time characteristic of a regular setting process. The maximum cycle time is derived from the process characteristic, in particular from the time characteristic of a typical or regular setting process. It can also be derived from the time requirements for the safety-related and / or quality-related properties of a setting process. Typically, according to the requirements and the characteristic time course of a joining process by the invention, a timely, process-true and realistic detection, monitoring and control as well as analysis of the current joining process can be ensured. The characteristic maximum cycle time can either be specified as part of a parameterization of the system or can also be determined and configured or preconfigured using a reference process.

The maximum clock time is advantageously determined on the basis of established sampling rules, taking into account the characteristics of the relevant joining operation. In the time domain, a maximum clock time, e.g. less than or equal to half of a time unit characteristic of the process. In the frequency domain, a characteristic system frequency or process frequency can be determined. According to the established sampling rules, a maximum clock time would correspond to a minimum frequency which is greater than or equal to half a system frequency characteristic of the system and / or half a process frequency characteristic of the process. This would correspond to the sampling rules of the sampling theorem, the applicability of which to a set operation constitutes a recognition of this invention.

A reliable function of the invention is ensured for a variety of applications, if in a regular setting the rivet mandrel is attracted by a tensile force insert to a rivet mandrel break and the maximum cycle time is less than or equal to half, in particular less than or equal to one tenth, more particularly less or equal One hundredth of the time between traction and rivet thorn break. For the description of a regular (or typical) setting process, reference is made to the above remarks on this term. For simpler, information technology systems and / or in the case of simple joining situations, the maximum cycle time can be in the upper range, that is, for example, close to half to 1/10 of the specified time duration. If more powerful, information technology systems for the implementation or control of the method according to the invention are available and / or in cases of demanding joining situations, the maximum cycle time can be measured relatively short. Then it may be, for example, 0.5 to 10 hundredths or even only 1 to 5 thousandths of a (typed, for example) period of time between tensile force application and rivet mandrel tear.

Reliable results in the sense of process reliability and / or in terms of joint quality and / or operator safety are ensured by virtue of the fact that the routine is carried out cyclically in deterministic real-time. It is ensured by information technology devices and methods that a run of a routine takes place within a specified (determined) cycle time. The thus selected cycle time is determined in accordance with a typical, regular setting process, so that the deterministic real time practically corresponds to a process real time. In terms of the regular setting process, the process real time ensures compliance with process-related, physical requirements, such as process-characteristic time units.

The invention has recognized that the advantages according to the invention are already achieved for a large number of setting processes when a deterministic cycle cycle time of less than or equal to 50 ms, in particular less than or equal to ten milliseconds, more particularly less than or equal to two milliseconds, is provided. By specifying such deterministic cycle cycle times, which are suitable in this way, a simple applicability and, in particular, a faster and more reliable configurability of a method or system according to the invention are achieved. Typical cycle cycle times are preferably in the range between two milliseconds and ten milliseconds. The typical cycle cycle times specified in this paragraph are applicable, for example, to integrated, in particular also hand-held, rivet setting devices.

A decisive improvement in the process reliability, the process quality, the joining quality and last but not least operator safety is achieved if at least one evaluation result includes the process information as to whether the component is missing during the setting process and / or is faulty and / or mispositioned (hereinafter: component defect). For example, In the field of automobile construction (for example in car final assembly), manual setting devices (for example battery charging devices) are predominantly used in which the blind rivet is first inserted by hand into the mouthpiece and the rivet shank is brought into the hole provided for this purpose. Then the process is started. In order to avoid erroneous starting of the process without a component, there is a mechanical pressure control in the prior art. This is a minimum force to be applied by the operator before the process can be triggered. In addition to the usually already relatively high weight of the battery-powered manual setting device, the operator is additionally burdened. When triggering the process without a component, the rivet sleeve would fly away like a bullet when removing the rivet mandrel and lead to a high injury potential. The process according to the invention avoids tearing off of the rivet mandrel without a component (in free space) by means of real-time evaluation of the measured tensile force-set travel data reliably and reliably.

Depending on the design of the blind rivets or the blind rivet nuts and possibly depending on the component and system configuration, it comes in the course of the applied tensile force on the set path to a characteristic Setzwegplateau. The invention has recognized that the aforementioned process information can be extracted on the basis of an automated recognition of this characteristic setting path plateau. Such an extraction of the desired information is technically simple and technically reliable to accomplish. A process computer can, for example, automatically evaluate the traction-Setzweg-course and monitor the characteristics of a regular setting process, such as a Setzwegplateau. Typically, the settable path plateau without a component is significantly longer. It can e.g. a maximum length of a relevant Setzwegplateaus be predefined and the current Setzwegplateau be determined by comparison with the maximum allowable length. If, for example, the maximum length of the set path plateau is exceeded in the pull-force set path, it can be output as the evaluation result that the component is missing and / or misplaced and / or is faulty.

In addition, the extraction of the process information with respect to the component can be achieved simply and reliably by an automated detection of a set path length. Analogous to the statements in the previous paragraph, a corresponding evaluation result can be transferred if a maximum setting path length is exceeded.

The extraction of the process information can be done by monitoring the tensile force-Setzweg data on the compliance of envelopes and / or limit curves. This has the advantage that reliable extraction can take place over a coherent, even larger, settlement path range. In the traction-Setzweg-course, an upper envelope and a lower envelope may be provided, which follow each with upper or lower distance substantially a regular traction-Setzweg course. Limit curves may also be provided which in their curve represent limit values of settlement path and / or tensile force data which, when a regular setting process is adhered to, should not be exceeded or exceeded.

A reliable detection and evaluation is already given when the process information is extracted by monitoring at least one characteristic for the presence and / or positioning and / or a condition of a component process window of a typical setting process. This can be done with information technology simple means by the monitoring window is limited to only one or more characteristic process window of the traction-Setzweg course. For example, a typical process window may include the time course shortly before the rivet pin is torn off. The process window can also be designed using a section defined by reference process. This will be discussed in more detail in the description of the figures.

• - Erkennung Setzwegplateau (Bereich ohne Kraftanstieg aber mit Zunahme des Setzweges von etwa mind. >50%, vorzugsweise >80% der Gesamtmaterialdicke)
• - Setzwegüberprüfung, wobei der Setzweg ohne Bauteil erheblich größer ist
• - Überwachung der Kraft-Weg-Kurve mittels Hüllkurven / Grenzwertkurven (z.B. +/-5% einer gemittelten Kraft-Weg-Kurve)
• - Überwachung der Kraft-Weg-Kurve mittels gezielt definierten Prozessfenstern

The question "rivets without component (= process termination)" can therefore be answered on the basis of force-displacement data:

• Detection pathway plateau (area without increase in force but with increase of the settlement path of at least> 50%, preferably> 80% of the total material thickness)
• - Setzwegüberprüfung, the Setzweg without component is considerably larger
• - Monitoring of the force-displacement curve using envelopes / limit curves (eg +/- 5% of an averaged force-displacement curve)
• - Monitoring the force-displacement curve using specifically defined process windows

It has already been mentioned above that in the prior art a pressure force applied by an operator is measured and a minimum force is required to detect the presence of a component. This is intended to prevent a setting process in the case of component errors. For the first time, the invention makes it possible for the relevant process information to be determined independently of such an external pressure force applied to the component, in particular by an operator. As a result, the setting process to a large extent safe and at the same time for the operator easier, especially with little to vanishing power to cope.

A potential safety risk for operators and for possibly locally present in the setting process people is substantially reduced to minimized when a detected component failure is a safe shutdown of the setting process, especially in time before a rivet mandrel break occurs; The invention is based on the assumption that in a regular setting operation the rivet mandrel is attracted by a tensile force insert up to a rivet mandrel tear. If the process information "component error" is present, then the above-mentioned, safe (also in terms of apparatus) shutdown is effected before the rivet mandrel break-off with component failure. This will be discussed further below.

Relevant process information, which is decisive for the joining quality of the connection, is the local overall component thickness. The invention makes it possible to reliably record this essential parameter and thus to make a significant contribution to quality assurance if an evaluation result includes the local overall component thickness of the component. The close-to-process detection of the traction-set path data makes it possible to determine the component thickness reliably, promptly and accurately and to use it for process control, analysis or process monitoring.

• - einen zyklischen Kommunikationskanal, über den das Prozesssteuermittel die Zugkraft-Setzweg-Daten empfangen kann,
• - eine Auswerteeinrichtung, die die Zugkraft-Setzweg-Daten verarbeiten kann, und
• - einen zyklischen Steuerkanal, über den die Nietvorrichtung nach Maßgabe eines Auswerteresultates der Auswerteeinrichtung zyklisch zu steuern ist und/oder einen zyklischen Überwachungskanal, über den die Nietvorrichtung nach Maßgabe eines Auswerteresultates der Auswerteeinrichtung zyklisch zu überwachen ist und/oder einen Ausgabekanal, über den ein Auswerteresultat der Auswerteeinrichtung zur weiteren Analyse auszugeben ist.

The invention also relates to an electrically operated Nietsetzvorrichtung for setting of rivet shank and rivet mandrel rivets or Blindnietmuttern, in particular cordless device for manual operation, in particular for performing a method according to one of claims 1 to 15, with a device head, in which a mechanism for gripping a rivet mandrel is provided, with pulling device for tightening a rivet mandrel and with drive for driving the pulling device, wherein in particular a drive is provided between the drive and traction device, wherein a Setzwegsensor is arranged in the Nietsetzvorrichtung such that it can detect with the covered Setzweg corresponding Setzwegdaten , and wherein a tensile force sensor is arranged in the Nietsetzvorrichtung such that it can detect with the applied tensile force corresponding tensile force data. Such a rivet setting device has all the above-mentioned properties and advantages of the method according to the invention and is suitable for carrying it out. For this purpose, a process control means is present, which comprises

• - a cyclic communication channel through which the process control means can receive the draft limit data,
• an evaluation device that can process the traction-set route data, and
• a cyclic control channel via which the riveting device is cyclically controlled in accordance with an evaluation result of the evaluation device and / or a cyclic monitoring channel via which the riveting device is cyclically monitored in accordance with an evaluation result of the evaluation device and / or an output channel via which an evaluation result is obtained the evaluation is output for further analysis.

The process control means is preferably an information technology device, for example a computer unit, which can be integrated in a hand-held device or embodied separately in a higher-level controller. The process control means is connected to the traction-set route sensors via a cyclic communication channel so that it can cyclically receive the traction-set route data. For the communication of the sensor data with the process control means usual communication protocols are used. Such communication protocols may be, for example, analog or digital communication means. For example, the sensors may output analog voltage signals that correspond to a sensor signal. However, they can also have a (preferably integrated) digital converter which converts the recorded sensor signals in the sense of an analog / digital converter into digital signals and transmits them via the cyclic communication channel to the process control means. The communication protocol between the sensors and the process control means also includes that a signal detected by the sensors is applied directly or indirectly to the corresponding process input (I / O interface, input / output interface) of the process control means.

The process control means likewise comprises an evaluation device; this can be integrated into the rivet setting device or superordinate to the rivet setting device. The evaluation device can process the traction-set route data, preferably cyclically. The evaluation result is used by the process control means to cyclically control the rivet setting device via a cyclic control channel and / or to cyclically monitor it via a cyclic monitoring channel and / or output via an output channel for further analysis. The latter output channel can, but does not have to be, configured cyclically.

• 1 eine teilweise geschnittene Ansicht auf eine erfindungsgemäße Nietsetzvorrichtung, in der die Funktionskomponenten als Funktionsblöcke schematisch gezeigt sind,
• 2 eine seitliche Draufsicht auf einen Blindniet, dessen Schaft teilweise geschnitten dargestellt ist,
• 3 eine seitliche Ansicht im zeitlichen Verlauf eines regelmäßigen Setzvorgangs, wozu eine Abfolge von Ansichten dem zeitlichen Ablauf folgend nacheinander dargestellt sind,
• 4 ein Zugkraft-Setzweg-Diagramm, in dem die Verläufe eines im Wesentlichen regelmäßigen Setzvorgangs und eines Setzvorgangs mit Bauteilfehler gezeigt sind.

The invention will be explained in more detail with reference to embodiments shown in the accompanying figures. Show it:

• 1 a partially sectioned view of a Nietsetzvorrichtung invention, in which the functional components are shown schematically as function blocks,
• 2 a lateral plan view of a blind rivet, whose shaft is shown partially cut,
• 3 a side view in the time course of a regular setting process, for which a sequence of views following the time sequence are shown sequentially,
• 4 a tensile force-Setzweg-diagram, in which the courses of a substantially regular setting operation and a setting operation are shown with component failure.

The invention will be explained roughly schematically with reference to embodiments and drawings. In the drawings, the same or functionally identical features are given the same reference numerals, unless otherwise specified in the description. Described features in the figures are separate and independent of other contained in the figures, with respect to these described characteristics independently realizable properties or embodiments - unless otherwise stated.

1 shows an electrically operated Nietsetzvorrichtung 20 in the form of a riveting tool 20 , which is designed as a handheld battery-powered mobile device. This riveting tool 20 is suitable for carrying out the method according to the invention. The hand-held riveting tool 20 has an accumulator 1 , who in the handle foot of the rivet setting device 20 is arranged. Also on the bottom side of the riveting tool 20 arranged there is an interface 2 in which connections for communication may be provided, for example with a higher-level control or generally with a control and drive system; In addition, there can be a charging connection for charging or an electrical connection for wired operation of the riveting tool 20 be provided.

Via a wiring harness 3 can each cable for forwarding signals between the interface 2 and the corresponding components in the upper part of the rivet setting device 20 be provided. The wiring harness 3 also includes the passage of the cable to the accumulator 1 as well as the corresponding components in the upper part of the rivet setting device 20 ,

With a start switch 4 becomes the rivet setting device 20 controlled by the operator, for example, initiated a blind riveting operation, interrupted or terminated. For the drive is an electric motor 5 provided by the accumulator 1 is supplied with power. The electric motor 5 drives a ball screw 7 via an intermediate gearbox 6 on. The electric motor 5 can - for example, not shown here, intermediate mechanical elements - be used for several or especially for all required, mechanical, automatic or automatic operations; so can the electric motor 5 driving a gripping device (not shown here) or also one or more conveying devices for use within the rivet setting device. The ball screw 7 in particular drives a tightening device for tightening a rivet mandrel 21 (see below).

Further, a rivet mandrel container 12 provided in the torn rivet mandrels 21 , for example, along the device axis 13 , can be promoted after the setting process, preferably automatically or automatically.

To determine a path is a Setzwegsensor 8th available; in the illustrated embodiment, the Setzwegsensor 8th a rotary encoder, the - directly or indirectly - the angular position or the change in the angular position of the electric motor 5 receives. The rotary encoder is a conventional rotary encoder as an angle measuring device on an electric motor or at the transmission input or transmission output. The rotary encoder can be designed, for example, as a resolver-for example for increased robustness-or as an optical encoder-for example for increased accuracy. Direct detection via linear measuring systems - for example inductive measuring systems - is also possible.

Between a device head 10 and the ball screw 7 is a tensile force sensor 9 provided that measures the applied tensile forces. Such a tensile force sensor 7 For example, it can be designed as a spring body force transducer, as a piezo force transducer, as a resistive force transducer, as a force transducer with oscillating elements or as a force transducer with electromagnetic compensation. For example, with higher accuracy requirements, a piezo force transducer is preferred. Spring body load cells are universally applicable and - depending on the design - also available at low cost.

The rivet setting device 20 also has control electronics 11 or a process control means 11 , In the following, for the sake of simplicity, only the term process control means will be used 11 used. In the process control means 11 For example, the control electronics provided with appropriate computer means; Furthermore, in the process control means 11 Also a control with corresponding analog or digital controllers are performed. In any case, the process control means contains 11 an evaluation device 16 , which is used to evaluate the data collected according to the invention. The process control means 11 can via a wireless module 14 with a higher-level control 15 communicate.

For a better understanding of the invention, the structure of a blind rivet 24 in the 2 shown. The invention is valid for all interchangeable types of fasteners or fasteners. Thus, the invention is also applicable to, for example blind rivet nuts. Without limitation of generality but in the following is a blind rivet 24 described:

The blind rivet 24 consists of a rivet pin 21 and a rivet 22 ; Furthermore, at the shaft end of the blind rivet is a rivet mandrel head 23 present, the one opposite the rivet thorn 21 Has enlarged diameter and with a plan side of the rivet shank 22 at least partially covered, so that he the riveting 22 take with you when you wear and deform, especially squeeze, can. If the rivet shaft 22 in a prepared through hole is used (and that together with the Nietdornkopf 23 ), lies the blind rivet 24 with a set head 25 in the setting position on the rivet head 23 opposite end of a component 31 (will be discussed in more detail below, see also 3 ). A shown shaft diameter 26 is larger than a likewise shown mandrel diameter 27 ; still is a breaking point 28 shown, in the embodiment shown a predetermined breaking point 28 axially within the rivet shaft 22 is arranged for a shaft break. Of course, the invention is also applicable to other embodiments, in particular for a predetermined breaking point 28 for a rivet mandrel break just outside the shank area, suitable.

Also for a better understanding of the invention, the course of a regular setting process 50 based on 3 explained in more detail. Shown is a sequence of states of a regular setting process 50 where the timing of the steps is from left to right. In the outermost, left picture is still the head of the device 10 a rivet setting device according to the invention 20 to see in the the rivet thorn 21 is fully implemented in the configuration shown. This is the rivet mandrel 21 not visible in the view shown. The blind rivet 24 lies with the curved side of the setting head 25 at the insertion end of the device head 10 on. The blind rivet 24 with respect to the Nietsetzvorrichtung 20 in the shown Configuration fixed axially and radially. It's one for a rivet setting process 50 prepared component 31 shown. This component has an illustrated mating pairing 31 , In the following, for the sake of simplicity, only the component will be described 31 Referenced. Into the component 31 is a through hole 30 introduced, through which the blind rivet used 24 with his riveting 22 can be inserted. This is the blind rivet 24 - with his rivet head 23 ahead - through the through hole 30 carried out. In the initial configuration shown, there is a joining partner between the two 32 and a back joint partner 33 a fugue 34 available. In a regular setting process, it can happen that between the individual joining partners 32 . 33 initially no full-surface contact exists.

In the second illustration from the left of 3 is the riveting 22 almost to the stop of the setting head 25 in the through hole 30 introduced, and shortly before placing the plan side of the setting head 25 on the outside of the add-on joining partner 32 , The device head 10 is in this representation in the term, with a pressure force F to the component 31 to be pressed. The pressure force F is thereby applied, for example, by an operator or - in a fully or partially automated configuration - by machine.

In the third illustration from the left of 3 lies the setting head 25 already complete with its flat side on the component 31 on; It is furthermore by means of a rivet setting device according to the invention 20 Applied tightening force of the shaft area already completely (because of the entrainment by the rivet mandrel head 23 ) against the back joint partner 33 squashed or deformed, creating a compressed shaft area 35 results, which completes the fixed joint connection. By further tightening the rivet mandrel 21 breaks the rivet thorn 21 at the breaking point 28 from (shown in the fourth illustration from the left), so after removing the device head 10 the in the 3 very right shown configuration of the set blind rivet 36 without rivet mandrel 21 results. In this configuration shown is the joint of the component 31 finished, with the joining partners joined together 32 . 33 a resulting component thickness 37 respectively. The joint 34 is closed by the inventive tightening and the two joining partners 32 . 33 lie directly against each other and have at least locally in the area of the joint a virtually full-surface contact.

Using the rivet setting device shown 20 can a method according to the invention as follows with reference to the 1 . 2 or. 3 (the procedure may be independent of the type of device):

With the rivet setting device 20 becomes a rivet thorn first 21 resorted. For this purpose, the rivet mandrel in a designated opening of the device head 10 introduced. A not shown gripping mechanism sets the rivet mandrel 21 within the device head 10 firmly. The rivet shaft 22 gets into the rivet opening 30 of the component to be riveted 31 with gripped and both axially and radially with respect to the device head 10 fixed rivet mandrel introduced.

The rivet thorn 21 is in the gripped state with the rivet head 23 ahead in the through hole 30 introduced, preferably so far, that the flat bottom of the collar of the setting head 25 on the surface of the component 31 rests. Usually, but not necessarily, thanks to the invention, the blind rivet 24 with a pressure force F against the component 31 pressed. For example, by pressing the start switch 4 the tightening process is started and the rivet pin seized 21 dressed. During the setting process 50 become continuous with a set way of travel 40 corresponding Setzweg data recorded and synchronously the associated, with an applied tensile force 41 corresponding traction data. These data are preferably each over the entire setting process 50 detected. The data can each still be provided with a time stamp in order to ensure a timely assignment of the corresponding data. During the current setting process 50 is - for example, in the process control means 11 - performed a cyclic and automated routine. Within this routine will be traction 41 -Setzweg 40 Data by the tensile force sensor 9 or the setting path sensor 8th detected. The collected data is sent to the evaluation device 16 cyclic and automated - ideally together with a timestamp - transmitted. In the evaluation device 16 become the traction 41 -Setzweg 40 Data is automated and processed cyclically. The evaluation result is used for analysis and / or for cyclic control and / or for cyclical monitoring of the setting process 50 provided.

The process control means 11 together with the evaluation device 16 is configured in terms of their information technology performance such that the above operations are cyclical and automated feasible and / or controllable. For that has the process control means 11 together with the evaluation device 16 for the cyclic tasks a real-time operating system and / or real-time communication means and / or a real-time computing device.

It is a particular realization of the invention that the component 31 both for the quality of the joint connection as well as security of the entire setting process 50 has a great significance. Referring to 3 it becomes clear that in case the absence of the component 31 and / or faulty or misplaced component 31 There are high safety risks or the joint quality (in the case of a faulty or misplaced component 31 ) may be inferior. Therefore, at least one evaluation result includes the process information as to whether the component 31 during the setting process 50 is missing and / or faulty and / or mispositioned (in the following, all these three cases will be referred to simply as component faults for the sake of simplicity). It will be explained in more detail below how this process information can be extracted from the data.

For the monitoring, in particular the quality control of the joint connection is a component thickness 37 very important. Therefore, according to the invention, the component thickness, in particular local total component thickness 32 of the component 31 as an evaluation result from the course of the train 41 -Setzweg 40 Data are extracted. How this extraction is accomplished according to the invention will also be explained below.

4 shows roughly schematically a tensile force 41 -Setzweg 40 Diagram, where on the abscissa the way (this is the distance traveled 40 ) and on the ordinate the corresponding traction 41 are represented for the respective Setzwegwert. The continuous curve shows a course 52 a regular setting process, the dashed curve a course 53 a setting process without a component 31 , Without limiting the generality, the dashed curve can also at least partially reflect the course generally with a component error.

In addition to the force-displacement evaluation, the torque-rotation angle profile (torque of the tension spindle as equivalent for the tensile force and rotation angle as equivalent for the tensile travel) can likewise be evaluated. Furthermore, the drive power or drive current can be used as a force equivalent and the process time as a path equivalent.

The regular course 52 begins with a plateau (indicated on the far left), where the traction 41 practically equal to zero. Only with a traction force 42 the traction begins 41 increase. This may be due to the fact that at the beginning mechanical play of the involved mechanical components is overcome. This can be a mechanical game of involved active components, but also mechanical play of the used blind rivet 24 his. After the traction force 42 begins a course zone in which the traction 41 increases, as the rivet head 23 the riveting 22 due to the tensile force 41 deformed, so that ( 3 ) the compressed shaft area 35 results. The tensile force 41 then increases up to one (in the case of the course 52 a regular setting process 50 short) pathway plateau (in the 4 is only the settlement path plateau 44 without component 31 provided with a reference numeral), in the course of which the tensile force 41 remains essentially constant. If in the embodiment shown the 3 the compressed shaft area 35 to the back joint partner 33 strikes, it comes to a further, steep increase, since now the rivet mandrel 21 (preferably at its predetermined breaking point 28 ) until the rivet torn off 43 is deformed. The path between traction 42 and rivet thorn break 43 can be used as a set path length 45 be designated. After the rivet thorn break 43 there is an abrupt drop in traction 41 until practically zero. In the case shown, it comes in the course 53 a setting process without a component 31 to a much longer Setzwegplateau 44 , This may be because - as stated above - existing component 31 the compressed shaft area 35 against the back joint partner 33 squeezed and a further contraction or further compression of the rivet shaft 22 prevented. In case of component failure, therefore, the rivet shank can possibly 22 be further contracted or deformed, whereby the extended Setzwegplateau 44 can result. It then comes in a component failure at a much later Nietdornabriss 55 , the course shown in dashed lines 53 (Component error) is shown further to the right. This way extension 54 until the rivet torn off 55 can - like many other of the features revealed here - be used for the evaluation.

If one assumes that in a regular setting process 50 (according to the course 52 in 4 ) of the rivet mandrel 21 from a traction force 42 up to a rivet thorn break 43 is attracted by the invention very well suitable starting points for the extraction of an evaluation result to the effect that it includes the process information, whether the component 31 during the setting process 50 is missing and / or faulty and / or mispositioned. Due to the invention, it is now possible to obtain this crucial information based on an automated detection of characteristic for this process information data patterns. From the illustration in 4 becomes apparent that even the automated detection of a Setzwegplateaus 44 in the traction 41 Set path 40 data makes this process information accessible according to the invention.

Likewise, it can be seen that the process information so safe before a rivet mandrel break 55 can be determined at component failure. If in the course 53 the traction peak that a rivet thorn tear 43 corresponds to a significant degree in the settlement path 40 shifted to larger setting paths occurs, can be assumed with high probability until safety of a component failure.

Also the set path length shown 45 should be during a regular placement process 50 are not significantly exceeded, so that the detection of the set path length 45 within the traction 41 -Setzweg 40 Data can be used to determine the process information mentioned. In the 4 is the setting path length 45 a regular setting process 50 (related to the course 52 shown); if the setting path length 45 or a substantially corresponding value is cyclically monitored as a criterion for a component error, the process information can be approximately at the time of Nietdornabrisses 55 or even previously determined. In the latter case, it is also possible to determine the process information by tracking the setting path length 45 ensure that the process information before the rivet mandrel tear 55 occurs at component failure, especially with safe, time interval.

In the 4 are also envelopes 46 . 47 or limit curves 46 . 47 shown, which can be used for the extraction of said process information "component error". This is an upper envelope 46 , a maximum value curve exists, which is monitored from a start time of the monitoring and their exceeding by the tensile force 41 is interpreted in the course as process information "component error". Likewise, a lower envelope 47 , a minimum value curve, provided, which is also carried from a start time and their underrun by the tensile force 41 is also interpreted in the course as process information "component error". Both (partial) envelopes 46 . 47 taken together form a resulting total envelope or a resulting total limit curve. The envelopes 46 . 47 For example, in the process control means 11 , in particular in the access of the evaluation device 16 or integrated into the evaluation device 16 , stored as reference value curves and used for cyclic processing or monitoring.

All reference values mentioned herein may also be based on one or more reference setting operations or regular setting operations 50 be continuously identified and / or continuously reviewed and / or improved for the implementation of the procedure.

Finally, a characteristic process window can also be used 48 be monitored, whereby the computational effort is kept relatively low. In the embodiment shown, the characteristic process window 48 designed so that it is just before the traction effort 42 begins and shortly after the end of the rivet thorn 43 ends, in each case based on the course 52 a regular setting process 50 ,

Based on the recorded history 52 a regular setting process 50 can also be the local overall component thickness 37 of the component 31 be determined. The local overall component thickness 37 can with the way extension 54 or with the length of the Setzwegplateaus 44 correspond. To determine the overall component thickness is preferably a reference setting process with inserted blind rivet 24 and without a component 31 carried out and the length of the Setzwegplateaus 44 and / or the path extension 54 determined and kept available, ideally stored in a storage means in the access of a Nietsetzvorrichtung invention. In a regular setting process, the total component thickness can then be determined by the set travel value of the tensile force 42 until the beginning of the traction peak, the rivet mandrel tear 43 is subtracted from the measured length of the set path plateau and / or from the path extension.

The total component thickness can also be determined indirectly, for example by the shaft length 29 of the undeformed rivet shaft 22 known and for example in the process control means 11 is stored as a parameter. The shaft length 29 can also automatically based on, for example, the length and / or the diameter 27 or on the basis of other, characteristic measured values of the rivet mandrel 21 - For example, via a stored in the process control means allocation table - are determined. When the shaft length 29 is known and about from nietdornkopfseitigen shaft end to the plane of the plane side of the setting head 25 extends, may have a local overall component thickness 37 determined by the set travel value of the Zugkrafteinsatz 42 until the beginning of the traction peak, the rivet mandrel tear 43 precedes, from the shaft length 29 is subtracted.

LIST OF REFERENCE NUMBERS

1

accumulator

2

interface

3

harness

4

starting switch

5

electric motor

6

transmission

7

Ball screw

8th

Put displacement sensor

9

Tension sensor

10

unit head

11

Electronic control system / process control means

12

Nietdornbehälter

13

feedback shaft

14

radio module

15

higher-level control

16

evaluation

20

Rivet setting / rivet setting

21

Mandrel

22

rivet

23

mandrel head

24

Rivet

25

setting head

26

Shaft diameter

27

Mandrel diameter

28

Breaking point (shaft break)

29

shaft length

30

Through Hole

31

Member / joining mating

32

on-site joining partner

33

back joining partner

34

Gap

35

Squashed shaft area

36

set rivet without rivet mandrel

37

component thickness

40

setting distance

41

traction

42

traction use

43

Nietdornabriss

44

Settable path plateau without component

45

Setzweglänge

46

upper envelope

47

lower envelope

48

characteristic process window

50

regular setting process

51

rupture force

52

regular setting process

53

Setting process without component

54

path extension

55

Rivet thorn break without component

F

pressure force

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102013221792 [0004]

Claims (17)

Method for setting blind rivets (24) or blind rivet nuts consisting of rivet shank (22) and tear-off rivet mandrel (21), in which a rivet mandrel (21) is gripped by a rivet setting device (20), in particular cordless tool for manual operation, a rivet shank (22) is inserted into a rivet opening (30) of a component (31) to be riveted and the gripped rivet mandrel (21) is tightened, with the steps performed during a setting operation (50): - detecting set travel data corresponding to a set travel path (40); - Detecting corresponding with an applied tensile force (41) traction data; characterized in that during a current setting operation (50), the following routine is performed cyclically and automatically: - detecting the pulling force (41) setting path (40) data, - transmitting the detected pulling force (41) setting path (40) data an evaluation device (16), processing of the pulling force (41) setting path (40) data in the evaluation device (16), providing at least one evaluation result for analysis and / or cyclic control and / or for cyclical monitoring of the setting process (50 ). Method according to Claim 1 characterized in that the routine is performed with a cycle tact time characteristic of a regular set operation (50). Method according to Claim 2 characterized in that the cycle tact time is less than or equal to a maximum clock time characteristic of a regular set operation (50). Method according to Claim 2 or 3 characterized in that in a regular setting operation (50) of the rivet mandrel (21) is attracted by a tensile force insert (42) to a rivet mandrel break (43) and the maximum cycle time is less than or equal to half, in particular one tenth, more particularly one hundredth, the time period between tensile force insert (42) and rivet mandrel tear (43). Method according to one of Claims 1 to 4 , characterized in that the routine is cyclically performed in deterministic real time. Method according to one of Claims 1 to 5 , characterized in that a deterministic cycle cycle time of less than or equal to 50 ms, in particular less than or equal to 10 ms, more particularly less than or equal to 2 ms is provided. Method according to one of Claims 1 to 6 , characterized in that at least one evaluation result comprises the process information as to whether the component (31) is missing during the setting process (50) and / or is faulty and / or mispositioned. Method according to Claim 7 , characterized in that in the evaluation, the process information is extracted based on an automated detection of a characteristic Setzwegplateaus (44) of the traction (41) -Setzweg (40) data. Method according to Claim 7 or 8th , characterized in that in the evaluation, the process information is extracted based on an automated detection of a set path length (45). Method according to one of Claims 7 to 9 , characterized in that in the evaluation, the process information is extracted by monitoring the tensile force (41) -Setzweg (40) data on the compliance of envelopes (46,47) and / or limit curves (46,47). Method according to one of Claims 7 to 10 , characterized in that in the evaluation, the process information is extracted by monitoring at least one for the presence and / or positioning and / or a condition of a component (31) characteristic process window (48) of a typical setting process (50). Method according to one of Claims 7 to 11 , characterized in that the process information is extracted independently of an external, on the component (31), in particular by an operator, applied pressure force (F). Method according to one of Claims 7 to 12 , characterized in that in a regular setting operation (50) of the rivet mandrel (21) is attracted by a tensile force insert (42) to a Nietdornabriss (43) and based on the present process information, a secure hold of the setting process (50), in particular safe in time the rivet mandrel tear (21) takes place. Method according to one of Claims 1 to 13 , characterized in that an evaluation result includes the local total component thickness (37) of the component (31). Method for setting blind rivets (24) or blind rivet nuts consisting of rivet shank (22) and tear-off rivet mandrel (21), in particular according to one of Claims 1 - 14 in which a rivet mandrel (21) is gripped by a rivet setting device (20), in particular cordless device for manual operation, a rivet shank (22) is introduced into a rivet opening (30) of a component (31) to be riveted and the gripped rivet mandrel (21) to to a designated Rivet mandrel tear (43) is tightened, with the steps performed during a setting process (50): - detecting setting path data corresponding to a traveled setting path (40); - Detecting corresponding with an applied tensile force (41) traction data; characterized in that during a current setting operation (50), the following routine is performed at least once, in particular cyclically and / or automatically, in particular after the rivet mandrel tear (43,55): - detecting the pulling force (41) setting path (40) data , - transmission of the detected traction (41) -setting path (40) data to an evaluation device (16), - in the evaluation device (16) calculation of the local overall component thickness (37) of a component (31) and provision of the local overall component thickness (37) , Electrically operated rivet setting device (20) for setting blind rivets (24) or blind rivet nuts consisting of rivet shank (22) and tear-off rivet mandrel (21), in particular cordless tool for manual operation, in particular for carrying out a method according to one of Claims 1 to 15 , comprising a device head (10) in which a mechanism for gripping the rivet mandrel (21) is provided, with pulling device for tightening the rivet mandrel (21) and drive (5) for driving the pulling device, in particular between drive (5) and Traction device is a transmission (6) is provided, wherein a Setzwegsensor (8) is arranged in the Nietsetzvorrichtung (20) that it can detect with the laid-back Setzweg (40) corresponding Setzwegdaten, and wherein a tensile force sensor (9) in the Nietsetzvorrichtung (20) is arranged to detect tensile force data corresponding to the applied tensile force (41), characterized in that there is a process control means (11) comprising - a cyclic communication channel via which the process control means (11) controls the tensile force (41 ) Receive path (40) data, - an evaluation device (16) that can process the traction (41) set path (40) data, and - a cyclic Steuerkan al, via which the Nietsetzvorrichtung (20) in accordance with an evaluation of the evaluation (16) is to control cyclically and / or a cyclic monitoring channel over which the Nietsetzvorrichtung (20) in accordance with an evaluation of the evaluation (16) is to monitor cyclically and / or an output channel, via which an evaluation result of the evaluation device (16) is to be output for further analysis. Nietsetzvorrichtung (20) according to Claim 16 characterized in that the cyclic task process control means (11) comprises a real time operating system and / or real time communication means and / or a real time capable computing means.

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