EP2723515A1

EP2723515A1 - Die and magazine for a forming tool

Info

Publication number: EP2723515A1
Application number: EP12727143.5A
Authority: EP
Inventors: Joachim Moeser
Original assignee: Newfrey LLC
Current assignee: Newfrey LLC
Priority date: 2011-06-21
Filing date: 2012-06-11
Publication date: 2014-04-30
Anticipated expiration: 2032-06-11
Also published as: EP2723515B1; WO2012175356A1; DE102011105341A1

Abstract

Die (22) for a forming tool (10), in particular for a punch riveting or clinching tool, having a first axial side (30), on which there is realized a recess (32) for receiving material to be formed, having an axially opposite, second side (34), and having coding means (36) realized to act together with corresponding decoding means (38) of the forming tool (10), the coding means (36) being realized on the second side (34).

Description

Die and magazine for a forming tool

[0001] The present invention relates to a die for a forming tool, in particular for a punch riveting or clinching tool, having a first axial side, on which there is realized a recess for receiving material to be formed, having an axially opposite, second side, and having coding means realized to act together with corresponding decoding means of the forming tool.

[0002] Further, the present invention relates to a forming tool having a die receiver, on which the decoding means are realized.

[0003] Finally, the present invention relates to a magazine for a forming tool, which magazine has a replacement-die receiver.

[0004] In the case of forming tools of the type described above, a forming or joining process is effected at relatively high pressures between a punch and a die. The material forming in this case is normally cold forming.

[0005] In the case of a punch riveting tool, two metallic sheet portions are joined to one another in that a punch rivet is driven into the sheets by means of a punch. In the case of a clinching tool, a joint is effected between two such sheets without use of separate rivet elements. Punch riveting and clinching tools of this type are known generally. [0006] In the case of such a forming tool, the die is generally exchangeable. This can be necessary, on the one hand, because of wear, material fatigue, etc. Frequently, however, it is also necessary to use a forming tool to perform differing types of forming or joining processes, which require differing dies.

[0007] The die in this case is normally inserted in a die receiver of a frame of the forming tool.

[0008] It is known from the document DE 203 00 679 Ul, for the purpose of preventing mistaken interchanges, to first insert a receiving bushing in the die receiver, the receiving bushing and a shank of the die having codings that are matched to one another in order to ensure that only a die provided with a corresponding coding fits into a receiving bushing provided with a corresponding coding.

[0009] Further, it is known to provide the dies with article numbers, and to apply a corresponding inscription to a riveter. Since, in the case of this embodiment, it is necessary for an operator to compare two inscriptions with one another before a die is inserted in the die receiver, in the case of this approach it is not possible for dies to be exchanged in a process-safe manner.

[0010] With the above-mentioned approach, in which a receiving bush is inserted in the die receiver, it can happen, despite incorrect codings, that an incorrect die is fitted in the forming tool through a high pressing force. In addition, in the case of this embodiment, the cross-section of the shank of the die is reduced, such that the strength of the die is diminished.

[0011] Against the above background, it is an object of the invention to specify an improved die and an associated forming tool, and a magazine for a forming tool, whereby it can be ensured that a die is prevented from being incorrectly inserted in a die receiver. [0012] Further, conversion and repair times are preferably to be minimized in the case of a die change.

[0013] The above object is achieved, on the one hand, by a die for a forming tool, in particular for a punch riveting or clinching tool, having a first axial side, on which there is realized a recess for receiving material to be formed, having an axially opposite, second side, and having coding means realized to act together with corresponding decoding means of the forming tool, the coding means being realized on the second side.

[0014] Further the above object is achieved by a forming tool having a die receiver for such a die, the die receiver having a surface that is aligned transversely in relation to the longitudinal axis and on which decoding means are realized.

[0015] In addition, the above object is achieved by a forming tool having a frame on which there is realized a die receiver for an exchangeable die, in particular a die of the above-mentioned type, a magazine for receiving at least one replacement die being fixed to the frame.

[0016] Finally, the above object is achieved by a magazine for such a forming tool, the magazine having a replacement-die receiver that has a surface on which decoding means are realized.

[0017] The measure of realizing decoding means on the second side of the die renders it unnecessary to insert a bushing in the die receiver of the forming tool. The shank of such a die can therefore be realized with a larger diameter, such that the strength of the die overall can be improved.

[0018] The coding means in this case can be electronic coding means, for example in the form of an RFID transponder or RFID tag. In this case, the decoding means on the die receiver are likewise of an electronic type, for example in the form of an RFID read device.

[0019] It is particularly preferred, however, if instead (or additionally) the coding means and/or the decoding means are of a purely mechanical type. In the case of this preferred embodiment, there is no need for elaborate electrical components, lines, etc. to be mounted on the die receiver, or on the die.

[0020] The mechanical coding means in this case can be realized in that features are realized on the second side.

[0021] The decoding means on the die receiver can be provided, on the one hand, directly on a die receiver of a frame of the forming tool. It is particularly preferred, however, if these decoding means are constituted by a separate insert that is disposed, for example, at the base of the die receiver. In the case of mechanical decoding means, such an insert then has complementary features on a side, or surface, that is opposite the second side of the die.

[0022] In the case of an embodiment in which a magazine for one or more replacement dies is disposed on the forming tool, conversion and repair times can be minimized in the case of a die change. Since, frequently, it is necessary for a die change to be effected very rapidly in order to reduce downtimes of the forming tool, the risk of an incorrect die being fitted can increase.

[0023] In order to ensure a rapid and reliable die change, the magazine usually contains a suitable replacement die. A magazine for one or more replacement magazines may be provided on the forming tool. Further, it is possible for a plurality of magazines of this type to be provided on a forming tool.

[0024] It is particularly preferred in this case if the magazine has a replacement-die receiver that has a surface on which decoding means are realized. [0025] The decoding means in this case can be identical to the decoding means that might possibly be realized in the die receiver of the forming tool.

[0026] Through this measure, it can be ensured from the outset that a correct die is accommodated in the magazine, such that, in the case of a die change, it can be assumed that the replacement die present in the magazine is the correct die. As a result, downtimes can be significantly reduced.

[0027] The magazine can then be refilled during forming-tool pauses that are provided in any case.

[0028] The object is thus achieved in full.

[0029] In the case of the die according to the invention, it is particularly preferred if the coding means have at least one coding device that extends axially.

[0030] The coding device that extends axially can be realized, for example, by an elevation going out from the second side of the die. Preferably, however, the coding device that extends axially is realized by an axial bore in the second side of the die.

[0031] According to a further preferred embodiment, the coding means include a first coding device that extends axially, and a second coding device.

[0032] The second coding device can be of the same type as the first coding device (electrical and/or mechanical).

[0033] Particularly preferably, the second coding device is a second coding device that extends axially, thus, in particular, an elevation or a recess. [0034] It is to be preferred in this case if the second coding device has a cross-section that differs from that of the first coding device.

[0035] In the case of this embodiment, the number of variants, thus the number of possible "codes", can be significantly increased.

[0036] It is further preferable in this case if the second coding device has a cross-section that differs from that of the first coding device.

[0037] For example, the first coding device can be a bore having a larger diameter, and the second coding device can be a bore having a smaller diameter.

[0038] The first coding device in this case can be realized, for example, in the manner of a position feature, by means of which it can be ensured that the die can only be inserted in the die receiver in a rotary position (in respect of the longitudinal axis). Such a first coding device is preferably disposed eccentrically in relation to the longitudinal axis.

[0039] In this case, the second coding device can be, for example, a type of key bore, which is displaced relative to the position feature. Each differing position of such a second coding device can then correspond to a unique code of the die. In order to enlarge the possible codes, the location of the position feature can be displaced, or a plurality of key bores (a plurality of second coding devices) can be provided.

[0040] It is understood that the decoding means are each a kind of "negative" of such mechanical coding means, in order to ensure that the die is unambiguously assigned to the die receiver.

[0041] Overall, it is particularly preferred if the die has a basic body on which there is preferably realized the recess for receiving material to be formed, and has a shank that extends axially therefrom and that has a diameter smaller than the diameter of the basic body.

[0042] In the case of this embodiment, the coding means can be realized, for example, on a radially extending offset/shoulder at the transition between the basic body and the shank.

[0043] It is particularly preferred, however, if the coding means are realized on the axial end face of the shank.

[0044] In the case of this embodiment, the entire radial transition surface between the basic body and the shank can be used to take up the relatively high axial pressures during a forming process.

[0045] In the case of the magazine according to the invention, it is particularly advantageous if the replacement-die receiver has a slider, at one axial end of which the decoding means are realized.

[0046] Owing to the provision of such a slider, its position in the case of insertion of an incorrect die can differ from that in the case of insertion of a correct die. These differing positions of the slider can then be used for further purposes.

[0047] It is particularly preferred if the slider is elastically biased counter to a receiving direction.

[0048] The slider in this case can be disposed in a basic position such that substantially no positional displacement occurs if a correct die is inserted. If an incorrect die is inserted, the slider in this case can change its position, against the action of the elastic bias. [0049] It is particularly advantageous in this case if the slider is set up to switch over an indication on an outside of the magazine in dependence on whether a replacement die matching the slider decoding means has been inserted in the replacement-die receiver, or whether a die whose die coding means do not match the slider decoding means has been inserted.

[0050] It can then be easily identified from the outside (via the indication) whether a matching replacement die is present in the magazine.

[0051] Further, in the case of the magazine according to the invention, it is advantageous if the housing of the magazine has an opening through which an axial end of the slider can emerge.

[0052] If, for example, a non-matching die is inserted, the end of the slider can emerge from the magazine housing, thereby constituting such an indication.

[0053] In the use of such a magazine, it is generally possible to dispense with the provision of decoding means in the region of the die receiver of the forming tool. It can then already be identified in the magazine whether a matching die is provided for the forming tool. In the case of a die change, the matching die can then simply be inserted in the die receiver.

[0054] Generally, however, it is possible for decoding means for identifying matching dies to be provided alternatively or accumulatively on such a magazine, and/or on the die receiver of the forming tool.

[0055] If no decoding means are provided on the die receiver of the forming tool, it is preferred if the die receiver is designed such that uncoded and coded dies of each type can be inserted in the die receiver. [0056] A method for checking a die for a forming tool can therefore include the steps of first inserting a die, provided with coding means, in a magazine that is provided on the forming tool and has decoding means, and, in the case of a die change, removing a die that has already been checked for correctness in the magazine, and inserting it in the die receiver of the forming tool.

[0057] It is understood that the above-mentioned features of the invention and those yet to be explained in the following can be applied, not only in the respectively specified combination, but also in other combinations or singly, without departure from the scope of the present invention.

[0058] Exemplary embodiments of the invention are represented in the drawing and explained more fully in the following description. In the drawing:

Fig. 1 shows a schematic representation of a forming tool according to the invention, in the form of a punch riveting tool;

Fig. 2 shows a schematic cross-sectional view of an alternative embodiment of a die according to an embodiment of the invention;

Fig. 3 shows a schematic cross-sectional view of a further embodiment of a die and of a forming tool according to a further embodiment of the invention; and

Fig. 4 shows a schematic cross-sectional view through a magazine according to an embodiment of the present invention.

[0059] A forming tool in the form of a punch riveting tool is represented in schematic form in Fig. 1 and denoted generally by 10. [0060] The forming tool 10 has a frame 12, which is realized as a so-called C-frame. At the upper end of the frame 12, a carriage 14 is mounted so as to be displaceable along a longitudinal axis 15. A punch 16, for performing a forming process, is disposed on the carriage 14. A punch rivet 18 is held by means of a holding device, not denoted in greater detail, on the punch 16.

[0061] Further realized on the frame 12 is a die receiver 20, for receiving a die 22.

[0062] The die 22 has a basic body 24 and has a shank 26, of a lesser diameter, extending axially therefrom. A radial surface at the transition between the basic body 24 and the shank 26 bears on a shoulder 28 of the die receiver 20.

[0063] The die 22 has a first axial side 30 that faces towards the punch 16. Realized on the first axial side 30 is a recess 32 for receiving material to be formed.

[0064] The die 22 further has a second axial side 34, which is constituted by an axial end face of the shank 26.

[0065] In a forming process, usually, two or more workpieces in the form of sheets are disposed between the punch 16 and the die 22. The punch 16 is then moved downwards along the longitudinal axis 15, as a result of which the punch rivet 18 is driven into the workpiece arrangement. A hollow shank of the punch rivet 18 in this case deforms radially within the workpieces and is deflected radially outwards, as a result of which a non-positive and positive joint is produced between the workpieces. The recess 32 in this case, because of its special shape, is instrumental in this type of material deformation of the workpieces, or of the punch rivet 18. The quality of the riveted joint produced as a result is influenced considerably by the punch rivet 18 used, the punch 16 and the die 22. Depending on the type of rivet joint, the combination of the respective components is defined, for example, during a sampling phase. Punch-riveted joints of this type are preferably used in the field of motor vehicle engineering, preferably in the field of body shell construction. Work- pieces of differing materials can be joined together by punch-riveted joints of this type. Owing to the large number of differing punch-riveted joints in a vehicle, differing die geometries are used in the same production. In this case, it must be ensured at each point in time that the respectively correct die 22 is fitted in the corresponding punch riveting tool 10.

[0066] A change of the die 22 is performed during a preventive service, in the case of a retooling or in the case of a breakage of the die 22.

[0067] In order for mistaken interchange of dies to be prevented in a process-safe manner, the die 22 has coding means 36. The coding means 36 in this case are realized on the second axial side 34 of the die 22. Fig. 1 shows schematically that the coding means 36 can be constituted by an axial elevation relative to the second axial side 34. As is yet to be explained in the following, the coding means 36, however, can also be realized, for example, by an axial cavity in the second axial side 34. Further, it is possible for the coding means 36 to be realized as electrical or electromechanical coding means, for example in the form of RFID transponders or RFID tags.

[0068] Provided in the case of this embodiment, in the region of the die receiver 20, are decoding means 38 that can decode the coding means 36 when the die 22 has been inserted, in order to detect whether the inserted die 22 is the correct die. The decoding means 38 can be constituted by an electrical or electromagnetic recognition device that decodes the coding means 36, for example in the form of a Hall sensor or the like.

[0069] It is particularly preferred, however, if the decoding means 38 are realized as purely mechanical decoding means. It is preferred in this case if the decoding means 38 constitute a negative to the mechanical coding means 36, in such a way that only a correct die 22 can be inserted in the die receiver 20. [0070] In the case of mechanical decoding means 38, these can be realized either directly on the frame 12 or, preferably, are realized on an insert, not represented in greater detail in Fig. 1, which is disposed, for example, at the base of the die receiver 20.

[0071] It is further shown in Fig. 1 that a magazine 40 is fixed to the frame 12 (or is otherwise directly adjacent to the forming tool 10). The magazine 40 serves to receive a replacement die 22'.

[0072] The magazine 40 in this case has a replacement-die receiver 42 and further has decoding means 38'. The decoding means 38' can correspond to the decoding means 38 that are provided in the region of the die receiver 20.

[0073] Consequently, it can be detected whether a replacement die 22' that is matched to the special forming tool 10 has been inserted in the magazine 40.

[0074] The decoding means 38' can be provided in addition to or as an alternative to the decoding means 38. In other words, by means of the decoding means 38' of the magazine 40, a first check can be performed as to whether a replacement die 22' that is matched to the forming tool 10 has been provided in the region of the forming tool 10.

[0075] In the case of a die change, the existing die 22 is then removed from the die receiver 20, and the replacement die 22' present in the magazine 40 is inserted. Since the replacement die 22' has already been identified in the magazine 40 as matching, it is not absolutely necessary for further decoding means 38 to be provided in the region of the die receiver 20.

[0076] It is further shown in Fig. 1 that the tool 10 can be fixed, for example, to a robot 50, which has a first arm 52a and/or a second arm 52b and, possibly, further arms. [0077] Fig. 2 shows a further embodiment, which, in respect of structure and functioning, corresponds generally to the embodiment of Fig. 1. Elements that are the same are therefore denoted by the same reference numerals. In the following, it is substantially the differences that are explained.

[0078] In the case of the die 22 of Fig. 2, only a basic body 24, but no shank, is provided. In this case, therefore, the coding means 36, in the form of an axial recess, are provided on an underside of the basic body 24, which constitutes the second axial side 34. In a corresponding manner, in the case of the embodiment of Fig. 1 coding means 36 could also be provided on the radial surface in the region of the transition between the basic body 24 and the shank 26.

[0079] In this case, the decoding means 38 are realized as an axial projection on the frame 12 (either directly on the frame 12 or on an insert that is inserted therein).

[0080] It can further be seen in Fig. 2 that the coding means 36 and the decoding means 38 are disposed with an eccentric offset in the radial direction relative to the longitudinal axis 15, as shown at 56. It can thereby be ensured that the die 22 is also inserted correctly in the die receiver 20 in the circumferential direction.

[0081] Fig. 3 shows a further embodiment, which, in respect of structure and functioning, corresponds generally to the embodiments described above. Elements that are the same are therefore denoted by the same reference numerals. In the following, it is substantially the differences that are explained.

[0082] Thus, it can be seen in Fig. 3 that the decoding means 38 are realized on an insert 60, which is disposed at the base of the die receiver 20.

[0083] It can further be seen that the coding means 36 have a first coding device 62, in the form of a first axial bore on the second axial side 34, the first coding device 62 being disposed with an eccentric offset in the radial direction relative to the longitudinal axis 15. In this case, owing to the first coding device 62, it can be ensured that the die 22 is fitted in the correct position in the die receiver 20. The coding means 36 further have a second coding device 64, in the form of a second axial bore on the second axial side 34. The second coding device 64 can comprise a cross-section that differs from that of the first coding device 62, for example a smaller diameter. The relative arrangement of the second coding device 64 in relation to the first coding device 62 enables the die 22 to be identified in an unambiguous manner. The relative location of the second coding device 64 in relation to the first coding device 62 therefore constitutes the "code" of the die 22. It is understood that, instead of the single second coding device 64, a multiplicity of second coding devices 64 can also be provided, in order to increase the number of possible variants of dies 22 (the quantity of codes).

[0084] Provided in a corresponding manner on the insert 60 are a first decoding device 66 and a second decoding device 68, which constitute a negative to the coding devices 62, 64.

[0085] An embodiment of a magazine 40 according to the invention is represented in Fig. 4.

[0086] The magazine 40 has a housing 70, within which a slider 72 is mounted so as to be movable in a longitudinal axis. The slider 72 in this case is disposed at the base of a replacement-die receiver 20' of the magazine 40, in which a replacement die 22' can be inserted.

[0087] The slider 72 has a first axial end 74, which faces towards the replacement-die receiver 20'. Provided at the first end 74 are decoding means 38', which can correspond, for example, to the decoding means 38 of the embodiments described above. [0088] The slider 72 further has a second axial end 76, which is assigned to an opening 75 of the housing 70 and can emerge from the latter.

[0089] The slider 72 is further biased, by a spring, in a direction counter to a receiving direction 77. A stop for creating an end position is shown schematically at 79. When the slider 72 bears on the stop 79, the second end 76 does not emerge from the opening 75.

[0090] If a replacement die 22' matching the decoding means 38' is inserted in the magazine 40, the slider 72 remains in the position at the stop 79.

[0091] However, if a non-matching replacement die 22' is inserted, as represented in Fig. 4, the slider 72 is displaced in the axial direction against the action of the spring 78, in such a way that the second end 76 of the slider 72 emerges from the opening 75.

[0092] By means of this emerging end, which, for example, can also be emphasized by colour, an indication 82 is created, through which it can be detected without difficulty and beyond doubt, from outside the magazine 40, whether the magazine 40 contains a matching replacement die 22'.

[0093] Further represented in schematic form at 80 is a fastening screw, by means of which a replacement die 22' inserted in the replacement-die receiver 20' can be fixed in the magazine 40.

Claims

1. Die (22) for a forming tool (10), in particular for a punch riveting or clinching tool, having a first axial side (30), on which there is realized a recess (32) for receiving material to be formed, having an axially opposite, second side (34), and having coding means (36) realized to act together with corresponding decoding means (38) of the forming tool (10),

the coding means (36) being realized on the second side (34).

2. Die according to Claim 1, the coding means (36) having at least one coding device (36; 62; 64) that extends axially.

3. Die according to Claim 1 or 2, the coding means (36) having a first coding device (62) that extends axially, and a second coding device (64).

4. Die according to Claim 3, the second coding device (64) being constituted by a second coding device that extends axially.

5. Die according to Claim 4, the second coding device (64) having a cross-section that differs from that of the first coding device (62).

6. Die according to any one of Claims 1 - 5, the die (22) having a basic body (24), and having a shank (26) that extends axially therefrom and that has a diameter smaller than the diameter of the basic body (24).

7. Die according to Claim 6, the coding means (36) being realized on the axial end face (34) of the shank (26).

8. Forming tool (10) having a die receiver (20) for a die (22) according to any one of Claims 1 - 7, the die receiver (20) having a surface that is aligned trans- versely in relation to the longitudinal axis (15) and on which decoding means (38) are realized.

9. Forming tool (10) having a frame (12) on which a die receiver (20) for an exchangeable die (22) is realized, in particular a die according to any one of Claims 1 - 7, a magazine (40) for receiving at least one replacement die (22') being fixed to the frame (12).

10. Magazine (40) for a forming tool according to Claim 9, the magazine (40) having a replacement-die receiver (42) on which decoding means (38') are realized.

11. Magazine according to Claim 10, the replacement-die receiver (42) having a slider (72), at one axial end (74) of which the decoding means (38') are realized.

12. Magazine according to Claim 11, the slider (72) being elastically biased counter to a receiving direction (77).

13. Magazine according to Claim 11 or 12, characterized in that the slider (72) is set up to switch over an indication (82) on an outside of the magazine (40) in dependence on whether a replacement die (22') matching the slider decoding means (38') has been inserted in the replacement-die receiver (42), or whether a die whose die coding means (36) do not match the slider decoding means (38') has been inserted.

14. Magazine according to any one of Claims 11 - 13, a housing (70) of the magazine (40) having an opening (75) through which an axial end (76) of the slider (72) can emerge.