EP1644148B1 - Method for connecting components by riveting - Google Patents

Abstract

The invention relates to a method for connecting components ( 5 ), whereby at least one rivet ( 1 ) penetrates at least one component ( 5 ), and a closing head ( 6 ) is molded on the rivet ( 1 ) or any given molded part ( 1 ) by means of a molding machine. According to the invention, prior to the deformation of the closing head ( 6 ) on the rivet ( 1 ) or the given molded part ( 1 ), a rivet projection (U) is determined for the respective determination of the molding parameters, such as the molding course, molding time, and molding force.

Description

The invention relates to a method for connecting components, in which at least one rivet passes through at least one component and by means of a forming machine, a closing head of the rivet or any shaped part is formed.

For example, in conventional methods US-A-6011482 or US-A-5216819 or EP-A-0820823 is placed to position a component pairing or a Bauteilnietverbindung the rivet through the component and a rivet overhang determined. If a measured or specific rivet protrusion lies outside of a minimum or maximum range or ridge overhang range, then a constant riveting result is not guaranteed and the machine stops or the riveted joint is declared as an exclusion. The disadvantage here is that very narrow tolerance ranges must be complied with. Therefore, it is necessary to use rivets that are exactly in the tolerance range. In addition, the bearing or the component must also be completed or manufactured in very narrow tolerance ranges, so that an optimal riveting is ensured in the riveting process.

These tolerance ranges are often exceeded or fallen below, which has the consequence that the riveting process must be stopped or a high number of rejects in the manufacturing process, which is undesirable.

Since riveting in large quantities are increasingly used for connecting components, rivets are often used, which are manufactured in lathes at a fairly high cost.

However, it is also conceivable that rivets can be used, which are manufactured, for example, cold-beaten and therefore are much cheaper to produce, however, have a greater tolerance range by a cheaper manufacturing process. In hitherto conventional manufacturing process such cheaper rivets can not be used to permanently manufacture or ensure an exact rivet connection in the manufacturing process. For example, the cold-rolled rivets may have a tolerance range of about 1 mm. The supernatant tolerance of the rivet supernatant, however, is in the above example in the tolerance range of about 0.3 mm. Therefore, in the riveting or forming process, since a constant forming path or a constant forming time is preselected, they are not usable to obtain a required and specified riveting joint.

The DE 193 46 463 A1 , on which the preamble of claim 1 is based, discloses a method for controlling a device for deforming a workpiece by means of a pressurizable tool, in which a rivet overhang is determined, and the riveting process, in particular whose process parameters are adaptable based on stored comparison curves for producing a batch ,

The present invention has for its object to improve a method of the type mentioned, in which cost rivets can be used and a riveted joint can be made, which still achieves a permissible rivet connection even when exceeding or falling below a permissible Nietüberstandes.

To achieve this object, the features of the characterizing part of claim 1.

In the present invention, it has proved to be particularly advantageous that a rivet projection of the rivet shank is determined exactly before the forming process or before deformation for each rivet connection or component pairing of rivet and component. If the rivet protrusion is within the tolerance range, the forming path and the forming time of the closing head are deformed to the correct rivet connection with preselected deformation parameters. If, however, the rivet passing through the component exceeds the permissible rivet protrusion, then the riveting or forming process is automatically compensated for the respective rivet connection when determining the actual rivet protrusion in the process according to the invention, in which deformation, forming time and forming force are changed and adjusted so that one more perfect riveting can be guaranteed. The same applies in the reverse case, if the actually measured and determined rivet protrusion before the forming process Minimum or minimum rivet supernatant below, so that then also influenced the riveting or forming parameters, such as forming and forming time. Preferably, after determination of each rivet protrusion, the forming process is automatically automatically redetermined or its parameters are newly determined and set as a function of the deviation from the required rivet protrusion.

In particular, as a correction factor, a percentage of the amount of exceeding or falling below permitted rivet overhang is used as a correction factor for the forming process parameters such as forming path, forming force and forming time.

It should also be within the scope of the present invention that are used to determine the actual rivet protrusion measuring elements, if necessary, mechanical Tastorgane, one of which scans the base surface of the component and the second, usually directly connected to the Nietdöpper, the height of the rivet when placing Measures on this to determine the rivet projection. It is also important in the present invention that the two Tastorgane lie in a common measuring axis. This makes it possible to measure with only one measuring channel. In addition, the measurement results can be calculated in real time in a processor.

Overall, rivets with wide manufacturing tolerances can be used in the present invention to obtain a consistently reliable riveting result. As a result, significant savings in the manufacturing process can be realized through the use of lower cost rivets. In addition, high accuracy, permanent process and rivet monitoring is ensured during the manufacturing process even with conventional rivets, whereby the error rate is minimized or even eliminated in the forming or riveting process.

• Figur 1 eine schematisch dargestellte Ansicht eines Nietes, eingesteckt in eine Öffnung eines Bauteiles vor dem Umform-, insbesondere Nietprozess;
• Figur 2 eine schematisch dargestellte Ansicht auf eine Bauteilpaarung nach dem Umformprozess, insbesondere ein korrekt verformter Schliesskopf;
• Figur 3 eine schematisch dargestellte Ansicht auf eine Bauteilpaarung, insbesondere auf ein Niet- und ein Bauteil bei nicht korrektem Schliesskopf und deformierter Lochleibung;
• Figur 4 eine schematisch dargestellte Ansicht auf eine feherbehaftete Nietverbindung, bei zu geringem Nietüberstand und fehlerhaftem Schliesskopf;
• Figur 5 eine schematisch dargestellte Ansicht eines korrekten Schliesskopfes einer Nietverbindung bei zu grossem Nietüberstand;
• Figur 6 eine schematisch dargestellte Ansicht einer Nietverbindung bei zu kleinem Nietüberstand aber korrektem Schliesskopf und korrekter Nietverbindung.

Further advantages, features and details of the invention will become apparent from the following description of preferred embodiments and from the drawing; this shows in

• FIG. 1 a schematically illustrated view of a rivet, inserted into an opening of a component before the forming, in particular riveting process;
• FIG. 2 a schematically illustrated view of a component pairing after the forming process, in particular a correctly deformed closing head;
• FIG. 3 a schematically illustrated view of a component pairing, in particular a rivet and a component with incorrect closing head and deformed Lochleibung;
• FIG. 4 a schematic view of a feerbehaftete rivet, too low rivet projection and faulty closing head;
• FIG. 5 a schematically illustrated view of a correct closing head of a riveted joint in excess rivet protrusion;
• FIG. 6 a schematically illustrated view of a rivet in too small rivet projection but correct closing head and correct rivet.

According to FIG. 1 For making a riveted joint or component pairing, a rivet 1 is pushed through an opening 2 until a shoulder 3 of the rivet 1 rests against a bearing 4 of the component 5. A cylinder-like rivet shank 1 or a component 1 to be deformed passes through the opening 2 and protrudes in a rivet protrusion U out of the component 5. After deformation, the rivet shank 1a or the component to be deformed is deformed into a rivet head 6. As a rivet 1, it is expressly understood, a supernatant of a component, which is to be connected by forming with another component to be understood. For the sake of simplicity, the term rivet is chosen in the present application as the supernatant of a component.

Depending on the manufacturing accuracy and tolerance of the rivet 1, it is important for the forming, in particular riveting process, for the rivet protrusion U to move within a tolerance range of the conventional manufacturing or riveting process. In this case, a minimum rivet protrusion U _min or a maximum rivet protrusion U _{max can be} predefined in order to permanently set the forming parameters, the forming force, forming speed, forming path and forming time in a conventional forming or riveting process in order to achieve a constant riveting result at this particular machine setting still within the permissible tolerance range. Component pairings or rivets with a rivet projection U, which exceed the rivet protrusion U _min or U _max up or down, are eliminated as scrap.

In a forming process, in particular a riveting process, for example by means of a doubler of a riveting machine, not shown here, as in particular in FIG. 2 is shown, the closing head 6 is formed, so that a closing head height H is formed. The closing head 6 is thickened in the region of the bearing hole 4. The closing head 6 also forms a sufficient grip on the bed hole 4 or opening 2 or bore, with no significant deformation of the component 5 in the region of Perimeter hole is visible. This closing head 6 is formed correctly.

In the embodiment of the present invention according to FIG. 3 the closing head 6 is not deformed correctly, since the bearing 4 is deformed. This may be due to the fact that in a conventional riveting or forming process the rivet protrusion U is too large and an allowable rivet protrusion U _{max has been} exceeded. In order to obtain a constant closing head height H, the component 5 or sheet, in particular its bearing 4, is bent or expanded and the shoulder 3 of the rivet 1 is compressed if the rivet projection U is too high. The riveted connection is incorrect.

A second possibility of error is that when falling below a rivet supernatant U or rivet supernatant U _min , as in particular in the embodiment according to FIG. 4 is shown to achieve a correct closing head 6 at a constant closing head height H too little material for the closing head 6 during forming is present, so that no sufficient attack of the closing head 6 on the bed hole 4 or opening 2 is achieved and additionally within the opening 2 no Compressing or pressing the rivet 1 is ensured, so that no sufficient rivet connection.

In the embodiment of the present invention according to FIG. 5 It is shown that in the implementation of the inventive method by the actual determination of the rivet supernatant for each riveting or for each component pairing before riveting by appropriate tactile or measuring organs that can be attached to the striker or on the spindle of a riveting machine, an exact rivet overhang U is first determined before the rivet start.

Then automatically in the present inventive method due to the Nietüberstandes to achieve a specified and correct riveting the Umformweg, the forming time, forming force, etc. over the respective rivet or for the actual existing Niet supernatant in the forming machine or in the riveting machine automatically adjusted or customized.

For example, if the rivet protrusion U is too large by an amount X, as in particular in FIG. 5 is pointed, controls the forming or riveting machine to a new closing head height H, which riveted by a certain percentage of the error X, by which the rivet protrusion U is too large, that is, it riveted by a selectable percentage X less than at a conventional method. This results in a more volume of rivet protrusion, which is located in the higher Schlieskopfkopfraum. This ensures that the function and a correct riveting is maintained. That is, a rivet may be used that has any ridge protrusion that exceeds the maximum rivet protrusion U _max to still provide perfect riveting.

However, this presupposes that the actually existing rivet protrusion U given for the respective rivet connection is determined exactly and the riveting process is automatically adjusted on the basis of the deviation from the nominal dimension of the given rivet protrusion, which affects the forming parameters, such as forming path, forming time, forming force, etc. ,

In the embodiment of the present invention according to FIG. 6 is indicated that the rivet supernatant U um an amount X of the rivet 1 is too small, in which case after determining the actual rivet protrusion U the forming machine, in particular the riveting machine controls to a new closing head height H, which has been reduced by a certain percentage of the amount or error X, ie, it will riveted deeper by a certain percentage, depending on the amount X of too small or too low rivet supernatant U. Also, the rivet protrusion U or the actual rivet protrusion is determined and then automatically taken to a new, to be traversed or riveting Closing head height with corresponding automatic adaptation of forming time and forming path or riveting time and riveting path. This ensures that if the rivet protrusion is too low, which is less than a rivet protrusion U, a correct rivet connection can nevertheless be produced so that the closing head has sufficient grip over the bore or perforation without deforming or obstructing the component or the bearing hole to damage. The functionality remains with correct riveting.

This results in the following advantage in the present invention that even outside the tolerance range rivets can be used to produce a correct riveted joint. This can be used on much cheaper rivets during forming or riveting process. The error rate is reduced, the rivet connection is optimized and improved. As a result, manufacturing costs are also saved. <B> Position number list </ b> 1 rivet 34 67 2 opening 35 68 3 paragraph 36 69 4 bearing stress 37 70 5 component 38 71 6 closing head 39 72 7 40 73 8th 41 74 9 42 75 10 43 76 11 44 77 12 45 78 13 46 79 14 47 15 48 16 49 U rivet projection 17 50 U _min rivet projection 18 51 U _max rivet projection 19 52 20 53 H closing head 21 54 22 55 X amount 23 56 24 57 25 58 26 59 27 60 28 61 29 62 30 63 31 64 32 65 33 66

Claims (10)

1. A method of connecting components (5), in which at least one rivet (1) passes through at least one component (5) and a closure head (6) is formed integrally on the rivet (1) or a desired shaped part (1) by means of a shaping machine, wherein the rivet projection (U) is determined before the deformation of the closure head (6) or the desired shaped part (1), and deviations of the rivet projection (U) from a permissible size are automatically compensated by automatic adaptation of the process variables, such as for example the shaping time, the shaping force or the shaping path, characterized in that a minimum rivet projection U min. or a maximum rivet projection U max. are pre-defined in order to produce a tolerance range of the rivet projection U, wherein the rivets, for example pairing of components, are removed upwards or downwards as scrap when the rivet projection U min. or U max. is exceeded.
2. A method according to Claim 1, characterized in that at least one measuring element, in particular two sensing members, are used for measuring the rivet projection, wherein a snap die is used as one of the measuring elements or is fastened there.
3. A method according to at least one of Claims 1 to 2, characterized in that the rivet projection (U) is calculated from the measurement values of the at least one measuring element in a calculating unit.
4. A method according to Claim 3, characterized in that after the rivet projection (U) has been determined a correction variable for the shaping process, in particular for the riveting process parameters, is calculated anew in each case in the calculating unit in order to determine the shaping path, the shaping time and the shaping force for each riveting.
5. A method according to at least one of Claims 3 to 4, characterized in that the calculating unit calculates the rivet projection (U) in real time.
6. A method according to at least one of Claims 1 to 5, characterized in that two measuring elements, in particular two sensing members, are used, which are situated on a common measurement axis, wherein the said measuring elements are coupled to a riveting spindle which carries the snap die and performs the riveting stroke.
7. A method according to Claim 6, characterized in that, when crossing, the second measuring element, in particular sensing member, transmits a signal to the calculating unit and deposits and stores the measurement value on the measurement axis of the first sensing member.
8. A method according to at least one of Claims 1 to 7, characterized in that the rivet projection (U) - determined from two measurement values by means of two measuring elements - of the same measurement axis does not necessarily correspond to the actual dimension of the workpiece or of the value to be clarified, but can have an offset with respect to the nominal value which is programmed or is to be represented.
9. A method according to at least one of Claims 1 to 8, characterized in that after the projection (U) of the determined component pairing has been determined a riveting start and a shaping path and a shaping time are compensated and adapted in a manner dependent upon the change in the rivet projection with respect to the actual value for each riveting to be carried out.
10. A method according to at least one of Claims 1 to 9, characterized in that before each shaping procedure, in particular before each riveting procedure, a compensation of component pairings, in particular the determination of the rivet projection, is carried out automatically, and an adaptation of the process parameters of the riveting and/or shaping machine takes place automatically with respect to the shaping work to be performed, the shaping time and the shaping path in a manner dependent upon the amount (X) deviating from the rivet projection (U) which is permissible and provided for.

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