GB2565191A

GB2565191A - Punch riveting device with counter-vibration coupling

Info

Publication number: GB2565191A
Application number: GB1808789.0A
Authority: GB
Inventors: Philipskoetter Andre; Karle Armin; Kauth Christoph; Woelke Florian; Dieterle Martin; Nickel Patrick; Ramsayer Reiner; Maul Steven
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2017-06-01
Filing date: 2018-05-30
Publication date: 2019-02-06
Anticipated expiration: 2038-05-30
Also published as: GB201808789D0; DE102017209274A1; GB2565191B

Abstract

In a method for operating a manufacturing apparatus with a punch riveting device 10, at least two components 11, 12 to be riveted and a rivet 20 are disposed between a punch 15 and a counter-holder 18. A vibration generator 32 vibrates at least one element 15 involved in the pressing in of the rivet 20 into the at least two components 11, 12. At least one actor (70, Figure 1),71, 72, 73, during an operation of the punch riveting device 10, generates counter-vibrations G in at least one component 60, (5) of the apparatus such that vibrations S produced in the at least one component 60, (5) are compensated at least partly. The riveting device may be mounted on a robotic arm which may include an actor (70) for producing the counter-vibrations. The vibrations detected by sensors (90), 91, 92 (such as acceleration sensors) may be used to generate a compensation signal for the actors. The sensed vibrations may also be used to evaluate or assess operation of the riveting process. A computing unit may be used to carry-out the method.

Description

The present invention relates to a method for operating a manufacturing apparatus with a punch riveting device, which serves to connect at least two components by means of a rivet and in which during operation vibrations are coupled in, as well as such a manufacturing apparatus.

Prior art

Methods and devices for punch riveting serve to connect at least two in particular flat formed components in a connecting area. A punch riveting method is characterised in that pre-drilling a hole in the components that are to be connected is not necessary. Rather, a rivet is pressed into the at least two components using a punch or a punching tool, whereby with a correspondingly formed counter-holder, for example in the form of a die, which cooperates with the punching tool, it is ensured that the rivet deforms in a certain way inside the components that are to be connected, in order to form a force-locking and formlocking connection between the components and at the same time to avoid a penetrating of the component not facing the rivet.

Furthermore, so-called ultrasound punch riveting methods and devices are known from for example EP 2 318 161 Bl or DE 10 2014 203 357 Al, in which a vibration generator, such as for example an ultrasound generator, is used in order to cause one or more elements to vibrate when connecting the components. With this vibration for example the force needed to press in the rivet is reduced.

Disclosure of the invention

According to the invention a method for operating a manufacturing apparatus and also a manufacturing apparatus with the characteristics of the independent patent claims is proposed. Advantageous designs are the object of the dependent claims and also of the following description.

A method according to the invention serves for operating a manufacturing apparatus with a punch riveting device, which serves to connect at least two components by means of a rivet, and which punch riveting device has a punch and a counter-holder, whereby the at least two components and the rivet may be disposed between the punch and the counter-holder. In this, the punch and the counter-holder may be disposed on a frame of the punch riveting device. By means of a vibration generator at least one element (punch, counter-holder, components, rivet) involved in the pressing in of the rivet into the at least two components is caused to vibrate. In order to press the rivet into the components a drive may be provided, which is disposed for example on the frame of the punch riveting device, by means of which a force can be exerted on the punch in the joining direction. The frame itself may be present in particular in the form of a C-frame or C-bracket. In particular the rivet and/or the punch and/or the counter-holder and/or at least one of the at least two components may be possible as the at least one element which is caused to vibrate when pressing in the rivet. In particular a sound generator, preferably an ultrasound generator, may be used as the vibration generator. It can also be useful if a holding-down clamp is provided, by means of which the at least two components can be pressed against the counter-holder or can be fixed on the counter-holder .

In this the sound generator can preferably also be connected to a vibration converter, which in turn is caused to produce vibrations, which, usefully, are transmitted via a booster (amplitude-increasing device) to the punch. The punch can then serve as a sonotrode. The manufacturing apparatus may be, for example, an industrial robot to which the punch riveting device is attached.

Furthermore, now by means of at least one actor during an operation of the punch riveting device countervibrations are coupled into at least one component of the manufacturing apparatus such that through the operation of the punch riveting device vibrations produced in the at least one component are compensated at least partly. The counter-vibrations coupled by means of the at least one actor into the at least one component may also be described as anti-noise. Piezoactors for example are possible as actors here. Preferably the actor is disposed on the at least one component. In particular a bearing component for the punch riveting device, for example an arm of the manufacturing apparatus or a connecting point of such an arm to the frame of the punch riveting device (in that case a bearing point), but also the frame of the punch riveting device, are possible as the at least one component.

During the operation of such a punch riveting device, the vibrations that are coupled actively into the mentioned at least one element, in order to improve the riveting process, inevitably are also transmitted into components of the manufacturing apparatus. This vibration energy transmitted into the component and in particular into the frame or the bearing component is therefore no longer available to the process and causes the component itself to vibrate. Such vibrations of the component can adversely affect the joining result, since these vibrations can act as a disturbance on the process or riveting process. Also, these vibrations for example in the frame or a bearing component lead to adverse noise emissions. This means in particular problems for persons who are present. Also, due to the vibrations in the manufacturing apparatus damage can occur in the manufacturing apparatus, e.g. if bearing points are damaged or age prematurely by the vibrations .

With the active coupling of counter-vibrations into the component proposed here it can be achieved that this component vibrates less or even not at all. In addition to the reduction in noise emissions this has in particular the advantage that the material of the component fatigues less quickly, as a result of which the life or service life of the punch riveting device or of the manufacturing apparatus can be considerably increased.

It is also possible that for example a recurring pattern of the vibrations in the component, which are caused in the operation of the punch riveting device, is detected and on the basis of which a corresponding pattern is generated for the counter-vibrations that are actively to be coupled in. This makes it possible very easily to eliminate recurring vibrations without always having to measure online.

It is, however, particularly preferred if the vibrations caused in the component are detected by means of at least one sensor, in particular an acceleration sensor, in particular continuously. Based on the detected vibrations then at least one compensation signal can be determined, whereby based on this at least one compensation signal by means of the at least one actor the counter-vibrations are coupled into the component. With this, in particular individually occurring vibrations can be compensated directly during the operation of the manufacturing apparatus. In this connection it is also possible that the counter-vibrations, which are coupled into the component, are adapted actively by a control means.

In this, preferably the at least one sensor is disposed on the component or a sensor disposed on the component is used. With this, vibrations that are caused in the component can be detected particularly quickly and accurately. In this connection it is also particularly preferred if such sensors are disposed at positions or points on the component at which there is a particularly good signal-to-noise ratio, at which therefore other disturbing signals are particularly low.

Advantageously the at least one sensor and the at least one actor are disposed at a distance from each other. For example the sensors and actors may be distributed over the whole of the manufacturing apparatus, in particular the frame and bearing components such as arms. This means a certain period between the detecting of a vibration and the following actuation of the actor, during which for example the processing of the mentioned compensation signal can be carried out. This leads to a better compensation quality.

It is also advantageous if the detected vibrations are used for an evaluation and/or assessment of the operating of the punch riveting device, in particular the punch riveting process. In this way any errors in the operating of the punch riveting device can be detected, for example if a course of the detected vibrations deviates from an expected course. In addition to or alternatively to the detected vibrations themselves, the compensation signal determined from this can also be used.

A computing unit according to the invention, e.g. a control unit for a manufacturing apparatus with a punch riveting device, is adapted, in particular in terms of programming, to carry out a method according to the invention.

The object of the invention is furthermore a manufacturing apparatus with a punch riveting device for connecting at least two components by means of a rivet, which has a punch and a counter-holder, whereby the at least two components and the rivet may be disposed between the punch and the counter-holder. Also, such a punch riveting device has a vibration generator, by means of which at least one of the elements involved in the pressing in of the rivet into the at least two components can be caused to vibrate, and also at least one actor for generating countervibrations. Here a computing unit according to the invention is now provided, which is adapted to carry out a method according to the invention. In this way the manufacturing apparatus, which comprises the computing unit as component or structural component, is adapted to carry out a method according to the invention. With regard to the advantages and designs of the punch riveting device, to avoid repetition, see the above explanations concerning the method.

Also the implementing of the method in the form of a computer program is advantageous, as this causes particularly low costs, in particular if an operating control apparatus is also used for further tasks and therefore is present anyway. Suitable data carriers for providing the computer program are in particular magnetic, optical and electric storage media, such as for example hard disks, flash memories, EEPROMs, DVDs, etc. A downloading of a program via computer networks (internet, intranet, etc.) is also possible.

Further advantages and designs of the invention can be seen from the description and the appended drawing.

It goes without saying that the characteristics stated above and those that are still to be explained below are usable not only in the combination given in each case, but also in other combinations or alone, without leaving the scope of the present invention.

The invention is shown schematically in the drawing on the basis of an example of an embodiment and is described below with reference to the drawing.

Description of the figures

Figure 1 shows in simplified form and schematically a manufacturing apparatus with a punch riveting device according to the invention in a preferred embodiment.

Figure 2 shows the punch riveting device from Figure 1, with which also a method according to the invention can be carried out, in a more detailed view.

Figure 3 shows schematically a course of a method according to the invention in a preferred embodiment.

Detailed description of the drawing

Figure 1 shows in simplified form and schematically a manufacturing apparatus 100 according to the invention in a preferred embodiment, which has a punch riveting device 10, which is described in even more detail below. The manufacturing apparatus 100 may for example be an industrial robot in a production hall, for example for bodywork construction for an automotive vehicle. The punch riveting device 10 is held by bearing components 3, 4 and 5, here in the form of arms, and can be moved. Also, a computing unit 80, which can serve as a control unit of the manufacturing apparatus 100, and also a display means or display 85, are shown. In this, an actor 70 is attached to the arm 5, with which counter-vibrations can be transmitted into the arm 5. Also, a sensor 90 is provided. For a further description, refer to the following explanations .

It goes without saying that the punch riveting device is illustrated only by way of example in connection with a manufacturing apparatus in the form of an industrial robot and that the punch riveting device can also be attached to and used with other handling devices or handling equipment (in the meaning of a manufacturing apparatus).

Figure 2 shows in more detail the punch riveting device 10 from Figure 1, with which also a method according to the invention can be carried out. The punch riveting device 10 has a frame 60, which preferably is present in the form of a C-frame or C-bracket, on which the individual elements with a punch riveting device are generally disposed in order to be able to take up the desired position to each other. With the frame 60 the punch riveting device 10 can be attached for example on an arm as shown in Figure 1.

The punch riveting device 10 has a punch (for example a sonotrode) 15, by way of example with a round crosssection. The punch 15 is enclosed radially by a (sleeve-shaped) holding-down clamp 16 and disposed moveably relatively to this in the longitudinal direction. The holding-down clamp is attached to the punch 15 by means of a spring. Furthermore, the punch 15 is coupled to a drive 50 which serves to exert a force F needed to press the rivet 20 into both the components 11, 12. The drive 50 may for example be controlled by means of the computing unit 80. Also, the holding-down clamp 16 is adapted to press against the surface of the component 11 facing the punch 15 with a hold-down force.

A counter-holder in the form of a die 18 is disposed on the side of both the components 11, 12 opposite the punch 15 and the holding-down clamp 16. The punch 15 and the die 18 are moveable in the vertical direction, in which also the holding-down clamp 16 is moveable, and relatively to each other. The holding-down clamp 16 and the die 18 serve to clamp or press together both the components 11, 12 between the holding-down clamp 16 and the die 18 during the machining by the punch 15.

The rivet 20, here by way of example a semi-tubular rivet, consists preferably of a material that is harder than the materials of both the components 11, 12, at least in the area of a rivet shank. The flat top-side of the rivet facing away from the component 11 is disposed in operative connection with the punch 15, which fits flat on the top-side of the rivet 20.

The punch 15 is connected to a (mechanical) vibration converter 30, which with a vibration generator 32, in particular an ultrasound generator, is excitable to produce oscillations or vibrations. In particular, in this, ultrasound vibrations are generated with a vibration width (distance between maximum positive and negative amplitude of a vibration) between 10 pm and

110 pm (corresponds to an amplitude from 5 pm to 55 pm) and a frequency between 15 kHz and 35 kHz or if applicable even higher. These vibrations are coupled into the rivet 20 from the vibration converter 30 via a booster 31 and the punch 15, which also serves as a sonotrode. With this, the vibration converter 30, the booster 31 and the sonotrode 15 together form a vibration system 39.

The drive 50 may be for example a drive with a ball, roll or planetary screw drive or the like, suitable for exerting a force F for pressing the rivet 20 into the components 11, 12. The booster 31 with the punch 15 is fitted on the drive 50 by means of a holding device 35. The vibration converter 30 sits over the booster 31.

Furthermore now by way of example vibrations S are shown, as they are generated by the vibration system 39 and transmitted into the frame 60 or also the arms of the manufacturing apparatus. This means that with this vibrations S are produced also in the frame 60 or the arms. In this, the vibrations are transmitted in particular at those points, via which the vibration system 39 is in contact with the frame 60, into the frame 60 and from there into the arms. In the example shown these are in particular the die 18 and the drive 50. These vibrations S then also spread in the frame 60 and the arms.

By way of example now three sensors 90, 91 and 92 are shown, by means of which the sound produced in the frame 60 or the arms can be detected. These sensors may in particular be acceleration sensors, namely in particular sensors that can measure or detect an acceleration acting on them. These may for example be inertial sensors, e.g. so-called MEMS sensors (microelectromechanical system).

These sensors 90, 91 and 92 can then be connected to the computing unit 80 so as to transmit data. Here, suitable signal lines are possible, but also for example wireless communication connections would be possible, provided that the sensors are then otherwise provided with power.

Furthermore by way of example four actors 70, 71, 72 and 73 are shown, by means of which counter-vibrations G can be coupled or introduced actively into the frame 60 or the arms. These actors may in particular be piezoactors. These actors can then for example be connected to the computing unit 80 in a suitable way, so that by suitable control the actors are excitable to vibrations, which then are coupled into the frame 60 or the arm.

Here, the sensors and actors are distributed over the manufacturing apparatus 100, in particular the frame 60 and an arm, and therefore are also at a distance from each other. It goes without saying that sensors and/or actors can be provided also at other positions for example of the frame, or also on other components of the punch riveting device. The positions at which the sensors or actors are disposed can be chosen such that the vibrations S can be detected particularly well or such that the counter-vibrations G can be coupled into the component concerned particularly well, and from there in particular can also spread well.

Figure 3 now shows schematically a course of the method according to the invention in a preferred embodiment, how for example it can be carried out with a punch riveting device according to Figure 2. The vibrations S can first be detected, as already explained in reference to Figure 2, for example during a process window, as shown here by way of example with the sensor 90, and sent to a calculation unit, in particular a control system 81, in the computing unit 80.

With this a compensation signal K can then be determined, which then here by way of example is applied to the actor 70 so that counter-vibrations G are generated by the actor and coupled into the component. With this the compensation signal K can be designed such that the counter-vibrations G based on this compensate as far as possible for the vibrations S caused in the frame. It goes without saying that a separate compensation signal can be determined for each actor .

Also, the detected vibrations S and/or the compensation signal K that has been determined or corresponding measurement data in each case can also be sent to an evaluation unit A, at which for example the corresponding punch riveting process or process course can be analysed and/or assessed. Also, in this way for example errors can be detected. The display that has already been mentioned can also be used for such an evaluation.

Claims

1. Method for operating a manufacturing apparatus (100) with a punch riveting device (10), which serves to connect at least two components (11, 12) by means of a rivet (20), and has a punch (15) and a counter-holder (18), whereby the at least two components (11, 12) and the rivet (20) may be disposed between the punch (15) and the counter-holder (18), whereby by means of a vibration generator (32) at least one element (15) involved in the pressing in of the rivet (20) into the at least two components (11, 12) is caused to vibrate, characterised in that by means of at least one actor (70, 71, 72, 73) during an operation of the punch riveting device (10) counter-vibrations (G) are coupled into at least one component (60, 5) of the manufacturing apparatus (100) such that through the operation of the punch riveting device (10) vibrations (S) produced in the at least one component (60, 5) are compensated at least partly.

2. Method according to claim 1, whereby the vibrations (S) produced in the at least one component (60, 5) are detected by means of at least one sensor (90, 91, 92) .

3. Method according to claim 2, whereby based on the detected vibrations (S) at least one compensation signal (K) is determined, and whereby based on the at least one compensation signal (K) the counter vibrations (G) are coupled into the at least one component (60, 5) by means of the at least one actor (70, 71, 72, 73).

4. Method according to claim 2 or 3, whereby the at least one sensor (90, 91, 92) is disposed on the at least one component (60, 5).

5. Method according to one of claims 2 to 4, whereby the at least one sensor (90, 91, 92) comprises an acceleration sensor.

6. Method according to one of claims 2 to 5, whereby the at least one sensor (90, 91, 92) and the at least one actor (70, 71, 72, 73) are disposed at a distance from each other.

7. Method according to one of claims 2 to 6, whereby the detected vibrations (S) are used for an evaluation (A) and/or assessment of the operating of the punch riveting device (10), in particular of a punch riveting process .

8. Method according to one of the preceding claims, whereby the at least one component comprises a bearing component (5) for the punch riveting device (10).

9. Method according to one of the preceding claims, whereby the at least one component comprises a frame (60) of the punch riveting device (10), which is preferably designed in the form of a C-frame or a Cbracket.

10. Method according to one of the preceding claims, whereby a sound generator, in particular an ultrasound generator, is used as the vibration generator (32).

11. Computing unit (80), which is adapted to carry out a method according to one of the preceding claims.

12. Manufacturing apparatus (100) with a punch riveting device (10) for connecting at least two components (11, 12) by means of a rivet (20), with a punch (15) and a counter-holder (18), whereby the at least two components (11, 12) and the rivet (20) may be disposed between the punch (15) and the counter-holder (18), with a vibration generator (32), by means of which at least one element (15) involved in the pressing in of the rivet (20) into the at least two components (11, 12) can be caused to vibrate, with at least one actor (70, 71, 72, 73) for coupling countervibrations (G) into at least one component (60, 5) of the manufacturing apparatus (100) and with a computing unit (80) according to claim 11.

13. Computer program, which causes a computing unit (80) to carry out a method according to one of claims 1 to 10, if it is executed on the computing unit (80).

14. Machine-readable storage medium with a computer program according to claim 13 stored on it.