Adaptable crimping ski and method of adapting a crimping ski.

Abstract

Crimping ski (1) intended to be fixed on a robot arm, comprising a crimping plate (3) with a working surface (30) intended to bend a sheet metal edge by sliding on said edge, a fixing face intended to bear against the robot arm, fixing means (31) to a robot arm. The ski comprises a compensation means (2) capable of modifying the position of the plate (3) relative to the fixing face, so as to compensate for a change in thickness of the plate (3) following machining of the working surface (30) over a machining thickness. Figure for the abstract: Fig. 1

Description

Title of the invention: Adaptable crimping ski and method for adapting a crimping ski.

[0001] The invention relates to a method for adapting a crimping ski, as well as an adaptable crimping ski to compensate for its wear.

[0002] In order to hold two sheets together at their respective edges, it is known to use a crimping ski comprising a working surface which, by its twisted shape, folds the edge of a first sheet against the edge of a second sheet, by sliding the ski along said edges. The ski is for example fixed to the arm of a robot. For example, document FR3101266 describes such a crimping ski, in which the crimping ski further comprises a plate on which a crimping plate is fixed. The plate is the part of the crimping ski which comprises the working surface folding the sheet edge as it slides over said sheet edge. The crimping plate is made of a hard material in order to reduce its wear during use. The plate forms an interface between the plate and the robot arm: it is pressed against a surface of the robot arm on which the ski is fixed.The insert, and in particular the working surface, is usually machined from a block of hard raw material, for example from a tungsten carbide part by electrical discharge machining.

[0003] The disadvantage is that when the insert is worn or damaged, it is necessary to change it completely. To do this, a new insert must be machined from a new block of raw material. Given the hardness of the material used for the insert, it is necessary to use specific machining processes, such as electro-erosion for a tungsten carbide insert. Changing the insert is therefore expensive and requires a significant amount of time for its machining.

[0004] The objective of the invention is to remedy these drawbacks. In particular, one of the aims of the invention is to propose a means of reducing the cost and time required for the renewal of a worn crimping ski.

[0005] This object is achieved according to the invention, thanks to a crimping ski intended to be fixed on an arm of a robot, comprising a crimping plate with a working surface intended to bend a sheet metal edge by sliding on said edge, a fixing face intended to bear against the arm of the robot, means of fixing to a robot arm, remarkable in that it comprises a compensation means capable of modifying the position of the plate relative to the fixing face, so as to compensate for a change in thickness of the plate following machining of the working surface over a machining thickness.

[0006] Thus, when the crimping plate is worn or damaged at its working surface, it is sufficient to re-machine the working surface to a thickness that is just necessary, depending on the damaged part, to restore its initial shape to said working surface, while the compensation means makes it possible to maintain the same thickness between the working surface and the fixing face, that is to say by maintaining the same spacing between the working surface and the fixing face. The compensation means therefore makes it possible to compensate for the loss of material from the plate following its re-machining, and to maintain the same position of the working surface once the crimping ski is installed on the robot arm.Thus, advantageously, the amount of material to be removed by re-machining is reduced compared to machining a new insert in a new block of material, because it only depends on the damaged part of the crimping insert, which reduces the re-machining time. In addition, reusing the damaged insert avoids having to remake a new part from a new block of material. The cost of re-machining a crimping insert capable of crimping effectively without defects is therefore reduced.

[0007] In a preferred embodiment of the invention, the plate comprises a rear face facing the compensation means, and a compensation thickness formed by the material of the plate between the working surface and its rear face, so that any point of the working surface is at least distant from said rear face by the value of this compensation thickness, the compensation thickness preferably being greater than 5 millimeters.

[0008] Thus advantageously, the working surface can be machined over a machining thickness to recreate a working surface of identical shape, the compensation thickness making it possible to guarantee a sufficient thickness for the insert to carry out re-machining of the entire working surface.

[0009] In one embodiment of the invention, the compensation means comprises at least one compensation plate, said plate comprising a first bearing face intended to bear against a rear face of the insert, and a second bearing face forming the fixing face, the plate being positioned with its first bearing face against the rear face of the insert so as to be between the insert and the fixing face in order to compensate for the loss of thickness after machining of the working surface, the compensation plate forming a compensation means.

[0010] Thus advantageously, the compensation means is achieved in a simple manner by compensation plates of suitable thickness. Once the wafer has been re-machined, it is sufficient to choose a plate with the thickness corresponding to the thickness of material removed from the wafer during re-machining. For example, if the wafer is initially fixed directly to the robot arm without a compensation plate, the thickness of the compensation plate to be fixed on the wafer corresponds to the thickness of material removed during re-machining of the insert.

[0011] In another embodiment of the invention, the compensation means comprises several compensation plates, at least one first compensation plate being arranged against the rear face of the wafer, and at least one second compensation plate arranged opposite the first compensation plate and comprising the fixing face, the second plate being arranged against the first plate, or one or more third plates being arranged between the second plate and the first plate. The plates are preferably fixed to the wafer or to each other.

[0012] Thus advantageously, the adaptation of the compensation means is done easily and quickly, without the need to dismantle the first plate, the compensation being carried out by the addition of a second plate directly fixed on the first plate, or by stacking three or more plates.

[0013] In another embodiment of the invention, the compensation plate(s) are held on the crimping plate by a screw.

[0014] Thus advantageously, the risks of dissociating the compensation plate(s) from the wafer following re-machining, for example when handling the crimping wafer with the appropriate compensation plate(s), are reduced.

[0015] In another embodiment of the invention, the crimping plate is made of a material chosen from carbides or ceramics, and the compensation plate(s) are made of steel, preferably the crimping plate is made of tungsten carbide.

[0016] The invention also relates to a method for adapting a crimping ski comprising a crimping plate with a working surface, a face for attachment to a robot arm, and a compensation means, the working surface and the attachment face being spaced apart from each other by a reference thickness, the method comprising a step of machining the working surface of the crimping plate according to a machining thickness, followed by a step of modifying the compensation means so that the thickness between the working surface and the attachment face of the crimping ski is equal to the reference thickness.

[0017] Thus advantageously, when the crimping plate is worn or damaged, it is not necessary to buy a new plate. Indeed, the step of modifying the compensation means makes it possible to adjust the thickness of the crimping ski between the fixing face and the working surface, and therefore the position of the working surface, once the material has been removed by machining. It is then possible to re-machine the crimping plate at its working surface while maintaining adequate positioning of the latter once the crimping ski is installed on a robot arm. In other words, the method makes it possible to reform the crimping plate by machining, and in particular to reform its working surface, in order to give it the appropriate shape to carry out the crimping, while ensuring identical positioning of the working surface which generates the folding of an edge of sheet metal to be crimped.

[0018] In a preferred embodiment of the invention, the step of modifying the compensation means comprises - a step of selecting or manufacturing a compensating plate with a thickness at least equal to the machining thickness, - a step of installing the compensating plate on the crimping plate.

[0019] The use of a compensating plate advantageously allows rapid and precise adaptation while ensuring effective support of the crimping tablet during crimping, the plate forming a stable wedge between the robot arm and the plate.

[0020] In a variant, if an initial plate is fixed to the plate at least before the machining step, the installation step is preceded by a step of removing said initial plate, the removal step being carried out before or after the machining step; the thickness of the compensating plate is chosen to be at least equal to the thickness of the initial plate plus the machining thickness.Preferably, the first plate and the compensation plate are reversibly fixed by screws on the plate and the method comprises a step of dismantling the first plate and a step of fixing the compensation plate by the screw.

[0021] In another embodiment of the invention, if the crimping ski comprises a first plate with a thickness arranged against the crimping plate, the step of modifying the compensation means comprises a step of selecting or manufacturing a compensation plate, the compensating plate being of thickness equal to the machining thickness, and a step of mounting the compensating plate on the first plate or between the first plate and the plate.

[0022] Thus advantageously, it is not necessary to discard the first plate, the thickness of the compensation plate being added to the thickness of the initial plate already present.

[0023] The invention will be better understood on reading the following description, given solely by way of example and with reference to the appended drawings, in which:

[0024] [Fig-1] represents a perspective view of a crimping ski according to the invention, on the side of a work surface.

[0025] [Fig.2] represents another perspective view of the crimping ski of [Fig.l], of the side of a compensation plate.

[0026] [Fig.3] represents a side view of a crimping ski according to the invention following machining.

[0027] [Fig.4] represents a side view of a crimping ski according to the invention following another machining situation.

[0028] [Fig.5] schematically represents the method according to the invention.

[0029] The drawings are schematic representations to facilitate understanding of the invention. The components are not necessarily shown to scale. The same references correspond to the same components from one figure to another.

[0030] [Fig.l] illustrates a crimping ski 1 intended to be fixed on an arm of a robot, called the robot arm. The crimping ski 1 comprises a crimping plate 3 with a working surface 30 intended to bend a sheet metal edge by sliding on said edge, a fixing face 20 intended to bear against the robot arm, and means 31 for fixing to a robot arm. The crimping ski 1 comprises a compensation means 2 which makes it possible to modify the position of the plate 3 relative to the fixing face 20, and thus compensate for a change in thickness of the plate 3 following re-machining of the working surface of said plate 3 over a machining thickness epU.That is to say that the compensation means 2 makes it possible to find the same reference thickness, or in other words the same distance, between the working surface 30 and the fixing face 20 after re-machining the plate at its working surface 30, that is to say after having removed material at this working surface 30 to give it a suitable shape.

[0031] The fixing means 31 is for example a series of holes passing through the crimping ski 1 so as to allow the passage of a fixing screw screwed onto the robot arm.

[0032] In Figures 1 to 3, the compensation means 2 is in the form of a compensation plate 2. The plate 2 comprises a first bearing face intended to bear against a rear face of the wafer 3, and a second bearing face forming the fixing face 20 intended to bear against the robot arm. The plate 2 positioned between the wafer 3 and the fixing face 20 compensates for the loss of thickness epU after re-machining of the working surface 30, and thus forms the compensation means 2. The crimping wafer 3 comprises a compensation thickness epC formed by the material of the crimping wafer 3, between its working surface 30 and its rear face, so that any point of the working surface 30 is distant from the rear face.For example, the compensation thickness epC is at least greater than 5 millimeters, or even 10 millimeters, in order to allow machining of the working surface 30 to a machining thickness epU removing sufficient material to erase, for example, scratches or a chip, or in order to allow several machining operations of the working surface during use of the crimping ski. A person skilled in the art will choose the compensation thickness adapted, for example, to the foreseeable or known degradation of the plate 3 and the number of desired reuses.

[0033] In an alternative embodiment shown in [Fig.3], the crimping ski 1 comprises a first plate 21, of thickness epl, arranged against the plate 3. The compensation means 2 is formed by a compensation plate 22 of thickness ep2 arranged against the first plate 21. Following the machining of a thickness epU of the working surface 30, the compensation plate 22 has been arranged against the first plate 21. The thickness ep2 of the second plate 22 is equal to the machining thickness epU of the working surface 30. The second plate 22 is for example fixed to the first plate 21. For example, in the case of re-machining of the working surface 30 to a depth of one millimeter, the compensation plate 22 used will have a thickness of one millimeter.

[0034] In the case where the wafer has undergone a first re-machining of its working surface over a first thickness, the first plate 21 forms a first compensation plate 21 for the first re-machining, while the second compensation plate 22 compensates for a second re-machining carried out after the first re-machining: the compensation means is then formed by the two compensation plates 21 and 22, the overall thickness of the compensation means then being the total of the thicknesses epl and ep2 of the two plates 21 and 22.

[0035] In another variant, in the event of carrying out a third re-machining of the wafer 3, the second plate 22 is replaced by another second compensation plate 22 of greater thickness than the previous one, so as to compensate for the second and third re-machinings.

[0036] In another variant not shown, an additional compensation plate is installed against the set of plates 21, 22 already present. This added plate becomes the second plate 22, comprising the fixing face 20 to the robot arm, while the old second plate 22 becomes a third plate arranged between the other two plates. The three plates are aligned, facing each other, so as to increase the thickness of the compensation means 2. Thus, as re-machinings of the working surface 30 of the crimping plate 3 are carried out, the number of compensation plates increases in order to compensate for the reduction in thickness of the crimping plate 3 for each re-machining.

[0037] [Fig. 4] illustrates the crimping ski 1 in which the plate 3 has been re-machined to a total thickness equal to the compensation thickness epC. The compensation plate 2 installed against the plate 3 has a thickness epl equal to the thickness epC, so that the thickness of the ski 1 remains equal to the reference thickness epO. In the illustration of [Fig. 4], the working surface 30 comes to the edge of the rear face of the plate 3, the rear face against which the compensation plate 2 is pressed.

[0038] The compensation plate(s) 21, 22 are for example fixed to the plate by at least one screw 4. In order to avoid disassembly in the factory using conventional tools, such as a crosshead or flat-head screwdriver, or even with an Allen key, the screw 4 may have a head of unconventional shape in order to require a specific tool. for its disassembly. Alternatively, the first plate is fixed to the plate 3, either by a screw or by other means known to those skilled in the art, and the other plates 22 are fixed to the first plate 21 or to each other. Alternatively, the fixing of the plate(s) 21, 22 to the plate or to each other is obtained by brazing.

[0039] In an alternative embodiment, the crimping plate 3 is made of a material chosen from carbides or ceramics, and the compensation plate(s) 21, 22 are made of steel. For example, the crimping plate 3 is made of tungsten carbide.

[0040] The method for adapting the crimping ski 1 is now described. The crimping ski 1 comprises a crimping plate 3 with a working surface 30, a face 20 for fixing to a robot arm, and a compensation means 2. The working surface 30 and the fixing face are spaced apart from each other by a reference thickness ep0. The reference thickness ep0 corresponds to the thickness of the new crimping ski 1, i.e. before it is used. [Fig. 5] illustrates different steps of the method. The method comprises: - a machining step 101 of the working surface 30 of the crimping plate 3 according to a machining thickness epU, - followed by a step 102 of adapting the compensation means 2 so that the thickness between the working surface 30 and the fixing face 20 of the crimping ski is equal to the reference thickness epO.

[0041] In other words, the modification step 102 of the compensation means makes it possible to find the same spacing between the working surface 30 and the fixing face 20. That is to say that the thickness between the working surface 30 and the fixing face 20 is again equal to the reference thickness ep0 despite the machining of the working surface. A person skilled in the art will understand from reading that the reference thickness ep0 depends on the measurement point on the working surface 30, such as for example when the working surface 30 is of complex shape, and that it is appropriate to compare thicknesses before and after machining with respect to the same reference point. For example, in [Fig.4], the thickness of the ski 1 is illustrated measured at the level of the point furthest from the fixing face 20 of the second plate 22, after re-machining on the machining thickness epU and the addition of said second plate 22 of thickness ep2 equal to the machining thickness epU; this thickness of the ski 1 is equal to the reference thickness epO.

[0042] In an alternative embodiment of the method, the step 102 of modifying the compensation means 2 comprises a step 102a of selecting or manufacturing a compensating plate 2 with a thickness at least equal to the machining thickness epU, followed by a step 102b of installing the compensating plate 2 on the crimping plate 3.

[0043] Alternatively, if an initial plate 21 is already fixed to the crimping plate 3 at less before the machining step 101, the installation step 102b is preceded by a step 102c of removing said initial plate 21 from the wafer 3. The thickness of the compensation plate 2 which replaces the initial plate 21 is for example of a thickness equivalent to the thickness epl of the initial plate 21 plus the machining thickness epU, so that the thickness of the compensation plate 2 installed on the wafer 3 compensates for the loss of thickness of the wafer 3 following the remachining and the loss of thickness following the removal of the initial plate 21.

[0044] For example, the initial plate 21 is a first compensation plate which has been installed on the wafer 3 following a first re-machining. This first plate 21 is dismantled and replaced by a new compensation plate 2 of greater thickness than the initial plate 21, in order to compensate for a second re-machining of the working surface 30.

[0045] In another variant of the method, a first plate 21 of thickness epl being arranged against the crimping wafer 3 before the re-machining step 101, the modification step 102 of the compensation means 2 comprises a step of selecting or manufacturing 101 a compensation plate 22 of thickness equal to the machining thickness epU, and a step 102 of mounting the compensating plate on the first plate 21 or between the first plate 21 and the wafer 3. The reduction in thickness of the wafer 3 to follow its re-machining is compensated by the addition of this compensation plate 22 of thickness equivalent to the reduction in thickness following the re-machining.

[0046] The machining thickness epU depends on the type of degradation to be removed at the working surface 30.

[0047] For example, repeated sliding of the working surface 30 on edges of sheets to be crimped, such as for example edges of exterior vehicle door panels to be crimped on a door lining, can create scratches of a few tenths of a millimeter which degrade the sheet to be crimped and increase friction. The re-machining of the working surface 30 is carried out so as to remove material over a thickness slightly greater than the depth of the scratches, a few tenths of a millimeter, in order to remove the material until the scratches disappear. The compensation plate 2 is then chosen to have a thickness equivalent to that of the re-machining, a few tenths of a millimeter, and installed directly against the plate if no plate was installed there.

[0048] Alternatively, if a first plate was already installed on the wafer 3, a new compensation plate 2 is produced with a thickness a few tenths of a millimeter greater than the first plate.

[0049] In another example, in the case of an impact during handling of the crimping ski 1 creating a chip on the working surface 30 of the crimping plate 3, the thickness of re-machining epU required to remake a 30 working surface without the chip is greater, for example several millimeters.

[0050] The fact of being able to re-machine the worn or damaged insert makes it possible to remake an insert 3 with a refurbished working surface 30, while reducing the quantity of material to be removed compared to remaking a new insert 3 from a new block of material, the re-machining only removing a small thickness epU of material compared to re-machining from a new block of material. The re-machining time is thus reduced, especially since the techniques for re-machining hard materials, such as tungsten carbide which requires electro-erosion machining, are long.

Claims

Claims

1. Crimping ski (1) intended to be fixed on an arm of a robot, comprising a crimping plate (3) with a working surface (30) intended to bend a sheet metal edge by sliding on said edge, a fixing face (20) intended to bear against the arm of the robot, fixing means (31) to a robot arm, characterized in that it comprises a compensation means (2) capable of modifying the position of the crimping plate (3) relative to the fixing face (20), so as to compensate for a change in thickness of the plate (3) following machining of the working surface (30) over a machining thickness (epU).

2. Crimping ski according to claim 1, the crimping plate (3) of which has a rear face opposite the compensation means (2), and a compensation thickness (epC) formed by the material of the crimping plate (3) between its working surface (30) and its rear face, so that any point of the working surface (30) is at least distant from said rear face by the value of this compensation thickness (epC).

3. Crimping ski according to claim 2, the compensation means (2) of which comprises at least one compensation plate (2), said plate (2) comprising a first bearing face intended to bear against the rear face of the crimping plate (3), and a second bearing face forming the fixing face (20), the plate (2) being positioned with its first bearing face against the rear face of the crimping plate (3) so as to be between the crimping plate (3) and the fixing face (20) in order to compensate for the loss of thickness after machining of the working surface (30), the compensation plate (2) forming the compensation means (2).

4. Crimping ski (1) according to claim 3, the compensation means (2) of which comprises several compensation plates (2), at least one first compensation plate (21) of which is arranged against the rear face of the crimping plate (3), and at least one second compensation plate (22) arranged opposite the first compensation plate (21) and comprising the fixing face (20), the second plate (21) being arranged against the first plate (20) or one or more third plates being arranged between the second plate (22) and the first plate (21), the plates (21, 22) being preferably fixed to the crimping plate (3) or to each other.

5. Crimping ski (1) according to one of claims 3 or 4, the compensation plate(s) (21, 22) of which are held on the crimping plate (3) by a screw (4).

6. Crimping ski (1) according to one of claims 1 to 5, the crimping plate (3) of which is made of a material chosen from carbides or ceramics, and the compensation plate(s) (3) are made of steel, preferably the crimping plate (3) is made of tungsten carbide.

7. Method for adapting a crimping ski (1) comprising a crimping plate (3) with a working surface (30), a fixing face (20) to a robot arm, and a compensation means (2), the working surface (30) and the fixing face (20) being spaced apart from each other by a reference thickness (epO), the method comprising a step of machining (101) the working surface (30) of the crimping plate (3) according to a machining thickness (epU), followed by a step of modifying (102) the compensation means (2) so that the thickness between the working surface (30) and the fixing face (20) of the crimping ski (1) is equal to the reference thickness (epO).

8. Method for adapting a crimping ski (1) according to the preceding claim, the step of modifying (102) the compensation means (2) comprising: a step of selecting (102a) or manufacturing a compensating plate with a thickness at least equal to the machining thickness (epU), a step of installing (102b) the compensating plate (21, 22) on the crimping plate (3), and if an initial plate (21) is fixed to the plate before the machining step (101), the installation step (102b) is preceded by a step of removing (102c) said initial plate (21) carried out before or after the machining step (101), the thickness (ep2) of the compensating plate (22) being chosen to be at least equal to the thickness (epl) of the initial plate plus the machining thickness (epU).

9. Method for adapting a crimping ski (1) according to claim 7, the crimping ski (1) comprising a first plate (21) of thickness (epl) arranged against the crimping plate (3), the step of modifying (102) the compensation means (2) comprising: a step of selecting or manufacturing (101) a compensation plate (22), of thickness equal to the machining thickness (epU), and a step of mounting (102) the compensating plate on the first plate (21) or between the first plate (21) and the crimping plate (3).

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