METHOD AND DEVICE FOR FORMING A SHAFT WINDING

Description

[0001] According to the preamble, the invention relates to a method for forming a wave winding using a flat template rotatable about its longitudinal axis, wherein a plurality of parallel wires are fed by means of a wire feeder perpendicular to the axis of rotation of the template, wherein the wires are alternately wound around the template by successively rotating it 180 degrees and formed into a wave winding by intermediate lateral displacement relative to the already wound wires, wherein during the winding of the wires the wire feeder follows the wires into the area of ​​the template. The present invention also relates to a device with the features of the preamble of claim 7.

[0002] Such a method with an associated device is known, for example, from DE 10 2015 120 661 A1. It has been found that problems can arise during the execution of the method because the wire feed protrudes into the area of ​​the template during winding, and the winding process therefore cannot be carried out to the ideal of a stepwise rotation of the template by 180 degrees, but must be aborted at an intermediate stage of less than 180 degrees. The incompletely bent winding ends result in tensions in the wires, which accumulate with the progress of the winding and complicate subsequent processing, since the wave winding in stator slots must be transferred in intermediate steps, possibly with the aid of tools with slots.

[0003] The object of the present invention is to enable better shaping of the winding heads during the manufacturing process of the wave winding. According to the invention, this object is achieved by one of the aforementioned methods, in which the template is first rotated by less than 180 degrees when winding the wires, in an intermediate step the partially formed winding heads are reshaped by means of forming jaws, then the wire feed is withdrawn from the area of ​​the template and finally the template is rotated further to 180 degrees for the final shaping of the winding heads.

[0004] The solution according to the invention offers the advantage that the wires are fixed in a position and optionally reshaped before the template has been rotated a full 180 degrees. This angular position corresponds to the maximum achievable angle at which the wire feed, required to stabilize the wires during the bending process, would collide with the rotating template if it were rotated further. The reshaping process then bends the wires to a 180-degree angle or beyond with respect to the half of the winding head located on the underside of the template. The heads are therefore fully formed, and no stresses can build up as a result of incomplete bending during the winding process.

[0005] After removing the wire feed, the template can be rotated further into the final position up to 180 degrees, before a shaping step in the axial direction with respect to the longitudinal extent of the template follows.

[0006] In a preferred embodiment of the method, the forming jaws are provided to remain closed until after the wire feed has been removed. This prevents frictional forces acting on the wires from the wire feed from undesirably deforming the winding heads.

[0007] To prevent the forming jaws from interfering with the winding process itself, it is intended that the forming jaws are only brought into contact with the wires for the duration of the forming process.

[0008] In a particularly preferred further embodiment of the method, it is provided that the reshaping is carried out by means of a one-sided or two congruent, two-sided recesses in the template and correspondingly shaped forming jaws such that the wires are first bent over to more than 180 degrees with respect to the wire position on the other side of the template.

[0009] This variant takes into account the fact that when the wires are bent around the edge of the template, they are not exclusively plastically deformed, but always exhibit an elastic deformation component, by which they spring back or which remains in the winding as a kind of spring tension. The overbending during the post-forming process compensates for the elastic deformation component; after the forming jaws are removed, the wires can spring back to their ideal position at 180 degrees.

[0010] The standard procedure involves rotating the template to an angle where the wire guide is just barely not in contact with the template before forming, although deviations are possible. Typically, the template is rotated approximately 175 degrees before forming.

[0011] The present invention also relates to a device for winding wave windings from a plurality of wires supplied parallel by means of a wire guide, which initially run perpendicular to the axis of rotation of a flat, sword-shaped template, which can be rotated stepwise by means of a drive device, and means for reshaping the winding heads.In order to achieve the aforementioned goal of producing a wave winding of higher quality, the means for reshaping the winding heads consist of a pair of forming jaws for reshaping a winding head, wherein the forming jaws are held on a movable device which, after interrupting a winding process and before reaching a 180-degree rotation, moves the forming jaws into the area of ​​the winding head and clamps and reshapes the last produced winding head against the template, and after retracting the wire feed and releasing the forming jaws, removes them again from the rotation area of ​​the template before the drive device completes the rotation process to 180 degrees, wherein the movements of the drive device, the wire feed and the movable device are coordinated by means of a control device.

[0012] According to the invention, means for reshaping the winding heads are integrated into the device and its operating procedure in the manner described above. Other types of reshaping devices, as known from the prior art, can potentially be omitted, and the windings produced with a device according to the invention are less stressed and more dimensionally stable, so that they can be processed more easily in subsequent steps.

[0013] Preferably, the control device interrupts the winding process before the wire feed comes into contact with the template and the reshaping process of the last produced winding head takes place in a rotational angle position of the template of approximately 175 degrees, and the forming jaws are formed on a forming pliers.

[0014] A particularly preferred embodiment of the device is one in which the template has a recess on one or both sides in the area of ​​the winding heads, which, in conjunction with forming jaws of a corresponding shape, enables a wire guide bent by more than 180 degrees. The advantages of the wire bending made possible by a device of this type have already been discussed above in connection with the description of a preferred embodiment of the method.

[0015] Further features, details and advantages of the invention will become apparent from the wording of the claims and from the exemplary embodiment described below with reference to the drawing. The drawing shows: Fig. 1 a) bis d) a schematic sequence of a partial winding process according to the status Fig. 2 a schematic top view of a single wire of a winding head; Fig. 3 a side view of the winding head Fig. 2 after a conventional partial winding process; Fig. 4 a detail of the bending point of the wire; Fig. 5 a device according to the invention; Fig. 6 a) bis f) a schematic sequence of the partial winding process according to the invention; Fig. 7 a side view of a preferred embodiment of the winding device; Fig. 8 an enlarged detail view X from Fig. 7 .

[0016] Fig. 1 Figure 1 shows the conventional sequence of a partial winding process for producing a flat wave winding 20 using a flat, sword-shaped template 10, which is rotatably mounted about a pivot axis 12 and is rotated stepwise by means of a drive device (not shown) to wind a plurality of wires, of which only one wire 14 is shown, onto the template 10. Between the partial winding processes, the wires undergo axial displacement / deformation so that the wave winding ultimately forms a ribbon. The wires 14 are fed and stabilized by means of a wire feeder 16.

[0017] A partial winding operation is performed by rotating the template 10 by slightly less than 180 degrees, after the wires in front of the template have been shifted laterally relative to the wires lying on the template. The center of the resulting inclined transition area lies in the region of a bending edge 18 of the template 10. The transition area is created by axial displacement (with respect to the longitudinal extent of the template 10) between the wire feed and a clamping device (not shown) provided on the template 10. This is known and can also be implemented accordingly within the scope of the present invention.

[0018] Starting from this in Fig. 1 a) In the state shown, the template is now rotated counterclockwise in the direction shown, whereby Fig. 1 b) It shows an intermediate position at a 90-degree rotation angle. This is clearly visible in... Fig. 1 b) the wire feed 16 following the wire, which prevents deformation of the transition area, which is responsible for forming the roof shape of the winding heads (see also Fig. 2 ) is needed.

[0019] In Fig. 1 c) A state is now shown in which the rotation of the template must first be aborted at approximately 175 degrees because the wire feed 16 would collide with the template 10 at a collision point K if the rotation were to continue. Depending on the geometry, the angle may also vary. However, a bend of 180 degrees is impossible.

[0020] In a further step, the wire feed 16 must now be withdrawn (see Fig. 1 d) ), before the template can complete half a turn for this partial winding step, see Fig. 1 e). However, the wires are no longer fixed near the bending edge 18, so they can no longer be plastically deformed. Elastic stresses remain in the wire, which accumulate as the winding progresses and make further processing of the wave winding after removal from the template 10 more difficult. Furthermore, removing the wire feed 16 can lead to deformation of the winding heads due to frictional forces introduced into the wires.

[0021] In Fig. 2 bis 4 The winding head area 20 produced after such a partial winding process is shown. Fig. 2 This illustrates the shape of the winding heads with the shape made possible by the transition area and completed by bending around the bending edge 18. From Fig. 3 It is easy to see what shape the wire would assume in a tension-free state. However, since further turns with winding heads follow, the tension remains in the wire. Fig. 4 This illustrates wire bending in detail. The bend B1 achievable with current practice is shown at approximately 175°, while next to it, the theoretical ideal bending state B2, desired for subsequent processes, is shown up to 180°. A section B3, which would need to be bent beyond this ideal section to account for springback in the wire, is shown adjacent to this ideal section.

[0022] Fig. 5 Figure 1 shows a device according to the invention which, compared to the prior art, is supplemented by a forming pliers 22 with two forming jaws 24, 26 that are movable into the engagement area with the template 10. All other parts of this simple embodiment correspond to the prior art. A device enables the forming pliers 22 to be moved between the in Fig. 5 shown position, in which reshaping of the previously produced winding heads is made possible by pressing together the forming jaws 24, 26, and a retracted position (see Fig. 6 a), e) und f) ), in which the template is freely rotatable during the partial winding processes.

[0023] Fig. 6 shows the steps of the inventive method using the in Fig. 5 device shown.

[0024] The differing sequence compared to the state of the art is in Fig. 6 a) shown, which in principle according to the state Fig. 1 c) This corresponds to when the rotation of the template 10 must be stopped to bend the wires 14 in order to avoid a collision of the wire feed 16 with the template.

[0025] In contrast to the prior art, before the wire feed 16 is withdrawn, the forming pliers 22 are brought into the engagement area with the previously wound wires, and the forming jaws 24, 26 are closed. During this process, the wires 14 are reshaped, and in particular, they are bent further in the direction of the 180-degree bend in the area of ​​the bending edge 18. Only after this reshaping is the wire feed 16 removed, with the forming jaws 24, 26 remaining closed, so that any frictional forces acting on the wires 14 during the removal of the wire feed 16 cannot deform the winding heads.

[0026] After removing the wire feed 16, the forming pliers 22 are opened and retracted, whereby the deformation produced in the engagement area of ​​the forming jaws 24, 26 is not visible in the illustration.

[0027] Since the wires 14 always exhibit an elastic deformation component, which manifests itself after removal of the forming tools in a springback of the wires or a tension remaining in the wire, the Fig. 7 und 8 The illustrated embodiment of the device features a template 110 which has recesses 30 or clearances in the area of ​​the winding heads in the forming area. These recesses interact with correspondingly shaped forming jaws 124, 126. Since the wires can be bent into the recesses 30, the overall bending angle in the area of ​​the bending edge 18 is greater than 180 degrees. This can be described as overbending the wires 14. After removing the forming jaws 124, 126, the wires can then spring back to a stress-free state with the ideal bending angle of 180 degrees, so that the produced wave winding has less overall stress and is subsequently easier to process.

[0028] All features and advantages arising from the claims and the description, including design details, spatial arrangements and process steps, can be essential to the invention both individually and in various combinations; the scope of protection of the invention is defined exclusively by the attached claims. Bezugszeichenliste

[0029] 10, 110 Template 12 Template pivot axis 14 Wire 16 Wire feed 18 Template bending edge 20 Winding head 22 Forming pliers 24, 124 Forming jaw 26, 126 Forming jaw 30 Recesses / Clearances 100 Shaft winding Collision point

Claims

1. A method for shaping a wave winding by means of a flat former (10; 110) rotatable about its longitudinal axis, wherein a plurality of parallel wires (14) are fed by means of a wire feeder (16) perpendicular to the axis of rotation of the former (10; 110), wherein the wires (14) are wound around the former (10; 110) in an alternating manner by stepwise rotation thereof and shaped into a wave winding (100) by intermediate lateral displacement relative to the wires (14) already lying on the former, wherein the wire feeder (16) follows the wires into the region of the former (10) during the winding of the wires (14), characterized in that the former (10) is first rotated by less than 180 degrees during the winding of the wires (14), the partially shaped end windings (20) are reshaped by means of shaping jaws (24, 26; 124, 126) in an intermediate step, then the wire feeder (16) is retracted from the region of the former (10) and finally the former (10) is rotated further to 180 degrees for the final shaping of the end windings (20).

2. The method according to claim 1, characterized in that the shaping jaws (24, 26; 124, 126) remain closed until after the wire feeder (16) has been removed.

3. The method according to claim 1 or 2, characterized in that the shaping jaws (24, 26; 124, 126) are brought into the engagement region with the wires (14) only for the duration of the shaping process.

4. The method according to any one of the preceding claims, characterized in that the reshaping is carried out by means of a recess (30) on one side or two congruent recesses on both sides in the former (10) and correspondingly shaped shaping jaws (124; 126) such that the wires (14) are first bent to more than 180 degrees with respect to the wire layer on the other side of the former (10).

5. The method according to any one of the preceding claims, characterized in that the former (10) is rotated before reshaping to an angle at which the wire feeder (16) is not quite yet in contact with the former (10).

6. The method according to claim 5, characterized in that the former (10) is rotated by approximately 175 degrees before reshaping.

7. A device for winding wave windings (100) from a plurality of wires (14) fed in parallel by means of a wire feeder (16), which first run perpendicular to the axis of rotation (12) of a flat, blade-like former (10), which can be rotated stepwise by means of a drive device and has means for reshaping the end windings (20), characterized in that the means for reshaping the end windings (20) consist of a pair of shaping jaws (24, 26; 124, 126) for reshaping an end winding (20), wherein the pair of shaping jaws (24, 26; 124, 126) are held on a movable device which, after a winding process is interrupted and before a 180-degree rotation is reached, moves the shaping jaws (24, 26; 124, 126) into the region of the end winding (20) and clamps and reshapes the last produced end winding against the former (10), and, after the wire feeder (16) is retracted and the pair of shaping jaws (24, 26; 124, 126) are released, removes said end winding again from the rotation region of the former (10) before the drive device completes the rotation process to 180 degrees, wherein the movements of the drive device, the wire feeder (16) and the movable device are coordinated by means of a control device.

8. The device according to claim 7, characterized in that the control device interrupts the winding process before the wire feeder (16) comes into contact with the former (10) and the reshaping process of the last produced end winding (20) is performed in a rotation angle position of the former (10) of approximately 175 degrees.

9. The device according to claim 7 or 8, characterized in that the shaping jaws (24, 26; 124, 126) are formed on a pair of shaping pliers (22).

10. The device according to any one of claims 7 to 9, characterized in that the former (10) has a recess (30) on one or both sides in the region of the end windings (20), which, in interaction with shaping jaws (124, 126) and a corresponding shaped portion, enables a guided wire portion bent by more than 180 degrees.