Device for bending an elongate part

Abstract

The present invention relates to a device for bending an elongate part (4) according to a determined shape, comprising a first element (1) and a second element (2), the first element (1) comprising a first receiving surface (11) and the second element (2) comprising a second receiving surface (21), one of the receiving surfaces (11, 21) comprising a groove (12, 22) configured to receive the elongate part (4), the groove (12, 22) having a shape corresponding to a part of the determined shape, the first receiving surface (11) and the second receiving surface (21) being shaped to conform to one another in an abutment position in which the groove (12, 22) is joined to the other receiving surface (11, 21), so as to constrain the elongate part (4) according to the determined shape when the second element (2) is in the abutment position.

Description

[0001] DESCRIPTION

[0002] TITLE: Bending device for an elongated workpiece

[0003] TECHNICAL FIELD

[0004] This presentation concerns the general field of industrial tooling, machine tools and processes used to bend and shape long parts, for example cables.

[0005] STATE OF THE ART

[0006] The shaping of elongated parts by bending, or bending, is usually carried out using hand tools when the desired shape is a two-dimensional flat bend, and with CNC machines when the desired shape involves multiple bends in different planes, i.e., in three dimensions. The use of hand tools (and therefore the integration of manual operations into the manufacturing process) implies less repeatability of the results obtained and a strong dependence on the skill and expertise of the operators, particularly for holding the elongated part during shaping and then for verifying that the resulting shape is correct. CNC machines, on the other hand, allow for operations requiring the application of significant force and offer better repeatability of these operations.

[0007] However, these machines are expensive and require precise prior calibration by an operator.

[0008] This results in excessive costs, particularly for parts produced in small batches. Consequently, there is a need for an inexpensive bending device capable of accurately repeating a three-dimensional shaping operation, without relying on operator skill.

[0009] DESCRIPTION OF THE INVENTION

[0010] One object of the invention is to overcome the aforementioned drawbacks by providing a device for bending an elongated part into a predetermined shape, comprising a first element and a second element. The first element comprises a first receiving surface, and the second element comprises a second receiving surface. One of the receiving surfaces comprises a groove configured to receive the elongated part. The groove has a shape corresponding to a portion of the predetermined shape. The first and second receiving surfaces are shaped to fit together in a stop position in which the groove is joined to the other receiving surface, so as to constrain the elongated part into the predetermined shape when the second element is in the stop position. The device according to the invention is advantageously complemented by the following features:taken alone or in one of their technically possible combinations: each receiving surface includes a groove, the grooves being joined when the second element is in the abutment position, thus allowing for better constraint of the elongated part; a third element comprising a third receiving surface and a support surface, the third receiving surface comprising a groove configured to receive the elongated part, the groove having a shape corresponding to a part of the determined shape different from the part corresponding to the groove of the second part, the first receiving surface and the third receiving surface being shaped to fit together in an abutment position in which the grooves of the first element and the third element are joined while the support surface fits the second element, so as to constrain the elongated part according to the determined shape when the third element is in the abutment position,The use of such a third element allows a long, elongated part to be bent into a more complex shape; the first element comprises a guide surface configured to guide the translation of and receive the second element in the stop position, thus allowing better control of the movement; the first receiving surface having either a concave or a convex profile in a plane comprising the elongated part, the second receiving surface having the other either a concave or a convex profile in the same plane, the profiles being configured to conform to a portion of the determined shape, so that the stop position is fixed and precise; the first element comprises a cavity whose profile includes an obtuse angle and a right angle connected by the first receiving surface in a plane perpendicular to the guide surface, the guide surface forming one side of the profile adjacent to the obtuse angle.This further improves the accuracy and repeatability of the relative movement of the elements; the respective grooves of the first and second elements are contiguous with the guide surface, the groove of the first element being located on the obtuse angle of the cavity and opening onto the guide surface, in order to prevent any unwanted displacement of the elongated part; the first and / or second element includes a slot perpendicular to the groove and configured to accommodate a fastener, so as to hold the elongated part in a groove. The invention also relates to a method of bending an elongated part into a shape determined by a device according to the invention, comprising the following steps:

[0011] - Positioning the elongated part in the groove of at least one of the first and second elements, - Moving the second element towards the first element by sliding the second element along the guide surface, until the second element abuts against the first element, thus constraining the elongated part in the groove(s) according to the determined shape. The method is advantageously completed by repeating the movement step for a third element until the third element abuts against the first and second elements.

[0012] Finally, the bending process of the invention is particularly suitable for an elongated part such as a heating element, a rigid or semi-rigid instrumentation cable or an instrumentation tube.

[0013] DESCRIPTION OF THE FIGURES

[0014] Other features, purposes and advantages of the invention will become apparent from the following description, which is purely illustrative and not limiting, and which should be read in conjunction with the accompanying drawings on which:

[0015] Figure 1 is a schematic view of the device according to a first embodiment of the invention;

[0016] Figure 2 is a series of schematic views illustrating the operation of the device according to the first embodiment of the invention;

[0017] Figure 3 is a series of cross-sectional views according to one embodiment of the invention;

[0018] Figure 4 is a series of cross-sectional views according to an alternative embodiment to that of Figure 3;

[0019] Figure 5 is a schematic view of a first element of the device according to a second embodiment of the invention;

[0020] Figure 6 is a schematic view of a second element of the device according to the second embodiment of the invention;

[0021] Figure 7 is a schematic view of the first element and the second element of the assembled device, according to the second embodiment of the invention;

[0022] Figure 8 is a diagram showing the steps of a process for implementing an embodiment of the invention.

[0023] Across all figures, similar elements bear identical references.

[0024] DETAILED DESCRIPTION OF THE INVENTION

[0025] Figures 1 to 3 illustrate a device for bending an elongated part according to a first embodiment. An elongated part is understood to be a part extending along its length, such as a cable.

[0026] Such a device comprises a first element 1 and a second element 2. Each element 1, 2 includes a receiving surface, respectively a first receiving surface 11 and a second receiving surface 21. One of the receiving surfaces 11, 21 includes a groove 12, 22 configured to receive the elongated part 4 to be bent. Alternatively, each receiving surface 11, 21 includes a groove 12, 22 configured to receive the elongated part 4 to be bent. The use of a single groove simplifies the manufacture of elements 1, 2.

[0027] The cross-section of the grooves 12, 22 is preferably adapted to the specific shape of the elongated part 4. It can thus be circular, ellipsoidal, square, etc. The grooves 12, 22 are preferably of equal depth relative to their respective receiving surfaces 11, 21 along their entire length. Each groove 12, 22 extends along a path, that is, a shape on its receiving surface 11, 21 corresponding to a portion of the defined shape.

[0028] On the other hand, the first receiving surface 11 and the second receiving surface 21 are of complementary shape, meaning that their receiving surfaces 11, 21 can be joined by a translational, rotational, or combined movement so that each surface conforms to the other. In other words, one is the opposite of the other. When the receiving surfaces 11, 21 are positioned in this way, the groove 12, 22 is then joined with the opposite receiving surface 11, 21, that is, the surface without a groove 12, 22. In the embodiment where each receiving surface 11, 21 has a groove, the grooves 12, 22 are then joined at their ends to form a continuous section of the same shape and size as the section of the elongated part 4.For example, if each groove 12, 22 has a semi-circular profile, the grooves 12, 22, in the abutment position, form a closed circular profile containing the elongated part 4, which in this case has a circular profile. The use of two grooves 12, 22 thus makes it easier to constrain the elongated part 4 by avoiding pinching it between the receiving surfaces 11, 21.

[0029] This position of the receiving surfaces 11, 21 and, by extension, of the first and second elements 1 and 2, is called the stop position. In this position, the grooves 12, 22 contain the elongated part 4 in a space that has the predetermined shape that is desired.

[0030] In a second embodiment illustrated in Figure 2, it is possible to use more than two elements to constrain the elongated shape 4. For example, a third element 3, similarly comprising a third receiving surface 31 to the first and second elements 1 and 2, the third receiving surface 31 comprising a groove 32 configured to receive the elongated part 4, can be used in combination with the first and second elements 1 and 2 to shape a section of the elongated part 4 not constrained by the first and second elements 1 and 2. The groove 32 therefore also has a shape corresponding to a part of the determined shape, but different from the part corresponding to the groove 22 of the second part 2.The first receiving surface 11 and the third receiving surface 31 are shaped to fit together in a stop position in which the grooves 12 and 32 of the first element 1 and the third element 3 are joined, in order to deform the elongated part 4 into the shape determined when the third element 3 is in the stop position. The movement of the third element 3 may be carried out on a different axis from the movement of the second element 2, each movement being designed to successively perform the shaping while limiting the risk of the elongated part 4 coming out of the grooves 12, 22, 32. Therefore, the movements may follow a non-rectilinear trajectory.

[0031] Preferably, as illustrated in Figure 3, the first element 1 includes a guide surface 13 configured to receive the second receiving surface 21 and the third receiving surface 31. This guide surface 13 is configured to guide the movement of the second element 2 or the third element 3 into the stop position, acting as a support, for example, a flat support to constrain a translational movement while the first element 1 is fixed, although any type of movement is possible. The guide surface 13 thus allows the elongated part 4 to slide progressively towards the grooves 12, 22, 32 while controlling the movement, thereby increasing the repeatability and accuracy of the forming process.

[0032] Advantageously, the first receiving surface 11 has a concave profile 111 in a plane including the elongated part 4, while the second receiving surface 21 has a complementary convex profile 211, that is, the concave profile 111 follows at least part of the convex profile 211. Of course, the converse is possible, the first receiving surface 11 being able to include a convex profile 111 while the second receiving surface 21 being able to include a concave profile 211.

[0033] A third element 3 is advantageously used when the first receiving surface 11 comprises a profile 111, part of which is convex and part concave. In this case, the profile 311 of the third receiving surface 31 of the third element 3 may be convex, and the profile 211 of the second receiving surface 21 may be concave, so that the abutment positioning of the second element 2 and the third element 3 joins the profiles 111, 211, and 311 to cover the entire profile 111. Preferably, the third element 3 may include a bearing surface 312 configured to cooperate with the second element 2.In other words, when the second element 2 is in a position of abutment with the first element 1, the movement which puts the third element 3 in a position of abutment with the first element 1 puts the bearing surface 312 in planar support with the second element 2, so that the second element 2 participates in putting the third element 3 in a more precise position of abutment.

[0034] To further improve the positioning accuracy of elements 1, 2, and 3, the first element 1 may include a cavity 14, illustrated in Figure 3, whose internal profile 15 comprises an obtuse angle 141 and a right angle 142 connected by the receiving surface 11 in a plane perpendicular to the guide surface 13 and encompassing the axis of movement. The guide surface 13 forms one side of the profile adjacent to the obtuse angle 141, so that the movement bringing the second element 2 to its stop position is constrained by the guide surface 13 and the movement terminates within the cavity 14 without allowing any displacement or slippage, particularly upwards, thanks to the right angle 142. Naturally, the profile of the second element 2 is complementary to the cavity 14; that is, it has a projection or counterform configured to occupy the entire internal space of the cavity 14.The groove 12 of the first element 1 is preferably located on the obtuse angle 141, which is distal to an outer edge of the cavity 14 and adjacent to the guide surface 13, while the groove 22 of the second element 2 is located on a complementary angle to the obtuse angle 141 of the cavity 14. In other words, the obtuse angle 141 is at one end of the guide surface 13 opposite to the one that first receives the second element 2.

[0035] Thus, in the cross-sectional plane of groove 12, a plane that includes the axis of movement and is shown in Figure 3, when the second element 2 slides on the guide surface 13, the groove 22 containing the elongated part 4 is contiguous with the guide surface 13; that is, it opens onto the guide surface 13, which keeps the elongated part 4 in groove 22 during movement. Furthermore, since groove 12 also opens onto the guide surface 13, the elongated part 4 is guided directly along the guide surface 13, reducing the risk of pinching it between the receiving surfaces 11 and 12.

[0036] Alternatively, in the case where only one of the elements 1,2 includes a groove, as illustrated in Figure 4, the groove 22 also opens onto the guide surface 13 and the elongated part 4 is brought to the desired position by following the guide surface 13, but the groove 22 is not necessarily located on a complementary angle to the obtuse angle 141, since there is no need to join the groove 22 with another groove.

[0037] Of course, if the above characteristics are described with a first element 1 and a second element 2, they are applicable in the same way to a third element 3 and to as many elements as are necessary to shape the entire elongated part 4.

[0038] In another embodiment illustrated in Figures 4 to 6, the first element 1 and / or the second element 2 comprise a slot 5 perpendicular to the grooves 12, 22 and configured to receive a fastener. By fastener is meant any means suitable for holding the elongated part 4 in the groove 12, 22 at least at one point, in order to prevent the elongated part 4 from leaving the groove 12, 22 during movement and being crushed between the receiving surfaces 11, 21.

[0039] Advantageously, the first element 1, the second element 2, and the third element 3 are produced by additive manufacturing, for example, from acrylonitrile butadiene styrene, polylactic acid, nylon composite, aluminum, or titanium. This allows for lower production costs and improved dimensional accuracy.

[0040] With reference to Figure 7, the process of bending an elongated part 4 into a shape determined by a device as described previously comprises a positioning step (step S1) of the elongated part 4 in the groove 12, 22 of at least one of the first element 1 and the second element 2. If a third element 3 is present (not shown in Figure 7), the elongated part 4 can also be positioned in the groove 32. A second movement step (step S2) of the second element 2 towards the first element 1 is carried out by sliding the second element 2, preferably on the guide surface 13, until the second element 2 abuts against the first element 1, so as to constrain the elongated part 4 into the determined shape. If a third element 3 (or more) is present, the movement step is repeated iteratively, taking into account any support surfaces 312, in order to progressively constrain the elongated shape 4.The movement step (step S2) can be carried out by any means, for example with a press moving the second element 2 while the first element 1 remains fixed. The movement path is designed so that the elongated shape 4 fits into all the grooves 12, 22, in order to avoid exerting any crushing force.

[0041] Optionally, a holding step (step S3) can be performed, during which the elongated part 4 is held in position in the grooves 12, 22, 32. It is also possible to heat-treat the elongated part 4 to relieve internal stresses during the forming process. This helps to limit the rebound of the elongated part 4 once it has exited the grooves 12, 22, i.e., to limit the tendency of the elongated part 4 to partially revert to its original shape.

[0042] The described device and associated method are particularly well-suited for shaping, bending, and folding elongated parts such as heating elements, rigid or semi-rigid instrument cables, or instrument tubes. Specifically, the device described herein exerts a progressive force during successive movements, compelling the elongated part to adopt the desired shape without exceeding its breaking point. This is particularly useful for shaping heating elements, which are inherently fragile and must be able to be inserted into grooves with non-planar geometry to prevent the part from freezing.With a prior art CNC machine, lengthy setup was required, and the fragility of such a part resulted in significant losses due to re-flattening and subsequent re-deformation caused by a lack of precision. Manual shaping, on the other hand, is time-consuming, complex, and also results in considerable losses. Finally, the process can be easily automated, particularly the element movement step (step S2), which does not require precise control of the applied force or trajectory. Compared to prior art processes, the implementation speed is greatly improved, especially for complex or three-dimensional shapes. The process is repeatable, standardized, and independent of the tooling operator's capabilities. The creation of complex shapes that would otherwise be difficult to achieve with a manual tool, such as a double-curvature shape, becomes readily achievable.

Claims

DEMANDS 1. Bending device for an elongated part (4) into a determined shape, comprising a first element (1) and a second element (2), the first element (1) comprising a first receiving surface (11) and the second element (2) comprising a second receiving surface (21), one of the receiving surfaces (11, 21) comprising a groove (12, 22) configured to receive the elongated part (4), the groove (12, 22) having a shape corresponding to a part of the determined shape, the first receiving surface (11) and the second receiving surface (21) being shaped to fit together in a stop position in which the groove (12, 22) is joined to the other receiving surface (11, 21), so as to constrain the elongated part (4) into the determined shape when the second element (2) is in the stop position,the first element (1) comprising a guide surface (13) configured to guide and receive the second element (2) and the elongated part (4) in the stop position.

2. Device according to claim 1, wherein each receiving surface (11, 21) comprises a groove (12, 22), the grooves (12, 22) being joined when the second element (2) is in the stop position.

3. Device according to claim 2, comprising a third element (3) including a third receiving surface (31) and a bearing surface (312), the third receiving surface (31) including a groove (32) configured to receive the elongated part (4), the groove (32) having a shape corresponding to a part of the determined shape different from the part corresponding to the groove (22) of the second part (2), the first receiving surface (11) and the third receiving surface (31) being shaped to fit together in a stop position in which the grooves (12, 32) of the first element (1) and of the third element (3) are joined while the bearing surface (312) fits the second element (2), so as to constrain the elongated part (4) according to the determined shape when the third element (3) is in the stop position.

4. Device according to any one of claims 2 to 3, wherein the first receiving surface (11) having either a concave profile (111) or a convex profile in a plane comprising the elongated part (4), the second receiving surface (21) having the other either a concave profile or a convex profile (211) in the same plane, the profiles (111, 211) being configured to fit a part of the determined shape.

5. Device according to any one of claims 4 and 4, wherein the first element comprises a cavity (14) whose profile (15) comprises an obtuse angle (141) and a right angle (142) connected by the first receiving surface (11) in a plane perpendicular to the guide surface (13), the guide surface (13) constituting one of the sides of the profile adjacent to the obtuse angle (141).

6. Device according to claim 5, wherein the respective grooves (12, 32) of the first element (1) and of the second element (2) are contiguous to the guide surface (13), the groove (12) of the first element (1) being located on the obtuse angle (141) of the cavity (14) and opening onto the guide surface (13).

7. Device according to any one of claims 1 to 6, comprising in the first element and / or the second element a slot (5) perpendicular to the groove (12, 22) and configured to accommodate a fastener, so as to hold the elongated part (4) in a groove (12, 32).

8. A method for bending an elongated part (4) into a shape determined by a device according to any one of claims 1 to 7, comprising the following steps: - positioning (S1) of the elongated part (4) in the groove (12, 32) of at least one of the first element (1) and the second element (2), - displacement (S2) of the second element (2) towards the first element (1) by sliding the second element (2) on the guide surface (13), until the second element (2) is butted against the first element (1), so as to constrain the elongated part (4) in the groove(s) (11, 22) according to the determined shape.

9. Method according to claim 8, wherein the displacement step (S2) is repeated for a third element (3) until the third element (3) is butted against the first element (1) and the second element (2).

10. Bending method according to claim 9, wherein the elongated part is a heating element, a rigid or semi-rigid instrumentation cable or an instrumentation tube.

Images