WO2017148619A1

WO2017148619A1 - Device and method for producing a wire segment bent in the shape of a wave

Info

Publication number: WO2017148619A1
Application number: PCT/EP2017/051268
Authority: WO
Inventors: Stefan Reuter; Christian Brückner; Hubertus Büttner; Christian Kirchner
Original assignee: Zf Friedrichshafen Ag
Priority date: 2016-02-29
Filing date: 2017-01-23
Publication date: 2017-09-08
Also published as: DE102016203167A1

Abstract

The invention relates to a device (100) for producing a wire segment (200) bent in the shape of a wave, in particular for use as a stator winding in an electric machine, comprising a linear guide (110) and a plurality of shaping tools (120a, 120f), which are mounted for longitudinal sliding and rotation on the linear guide (110) and which each have a holding region for fastening the wire segment (200) to be bent. The shaping tools (120a, 120f) can be rotated (a, b) in opposite directions and, at the same time, can be moved together along the linear guide (110) such that the wire segment (200) fastened thereto can be bent into a wave shape. The invention further relates to a method for producing a wire segment (200) bent in the shape of a wave, which method can be carried out by means of said device (100).

Description

Apparatus and method for producing a

Wavy curved wire segment

The invention relates to a device and a method for producing a corrugated bent wire segment or piece of wire, in particular for further use as a stator winding in an electrical machine.

Electrical machines of the kind in question, such as in particular electric motors and generators, have a fixed stator with a stator winding and a rotatably mounted inside the stator rotor (inner rotor). Typically, the stator is formed on its inner circumference or outer periphery with axially extending longitudinal grooves that provide receiving spaces for the stator winding. The stator winding is an electrical coil of lead wire (usually an insulated copper wire) made from a single long wire or multiple wires, which is sometimes very expensive. A common manufacturing method provides that the stator winding is produced by directly winding at least one conductor wire onto the stator or stator body. Another common procedure provides that individual conductor wire segments or pieces are first preformed and then inserted into the grooves or receiving spaces of the stator.

EP 1 974 443 B1 describes a method for producing a stator of a rotary electric machine. To form the stator winding, the conductors are deposited by means of a laying head on a linear support in a first step, wherein this support is formed with notches into which the conductors are arranged by wave-like folding and / or bending in several layers. In two transfer steps, the wavy preformed conductors are then first transferred from the linear support to an annular support and from there to the stator.

With the invention, a novel device and an executable thereby method for safe and repeatable production wavy curved Wire segments, in particular for further use as a stator winding in an electrical machine, are provided.

This is achieved with a device according to the invention corresponding to the features of patent claim 1 and with a method according to the invention corresponding to the features of the independent patent claim. Preferred developments and refinements of the invention are analogous to both subject matters of the dependent claims, the following description and the figures.

The inventive device for producing wavy bent wire segments comprises (at least) a linear guide, in particular a rail or the like, and a plurality of molds (at least two), which are mounted longitudinally displaceably and rotatably on the linear guide and each (at least) a receiving area for fixing at least one have to be bent or forming wire segment. In order to be able to deform or bend the wire segment fixed to the molding tools into a defined wave shape, the molding tools can be rotated in opposite directions and at the same time can be moved together or pushed together along the linear guide.

A wave-shaped wire segment made with the device according to the invention has forward and backward sections and these connecting transitions in the form of turn sections or transition sections, resulting in a waveform approximately in plan view. It is preferably provided that the waveform has substantially parallel straight sections and connecting turning sections or transition sections connecting them. The straight sections form the groove sections, which are later inserted into the grooves or receiving spaces of the stator or stator body (for example a stator lamination stack). The turning sections connect the groove sections outside of the stator slots. It is possible that the turning sections overlap a plurality of stator, so the groove sections of a wire segment are not arranged in immediately adjacent stator slots. The device according to the invention (the same applies to the method according to the invention) enables the simple, process-reliable and reproducible production with a defined waveform of bent wire segments, the device according to the invention making do with few forming tools. Since all groove and turn sections of the waveform are generated substantially simultaneously, there is a very short cycle time (especially in comparison to a stepwise shaping of the wire by individually executed bending steps). Due to the gentle deformation of the wire, in particular a lead wire, already with an electrical insulation, eg. An insulating varnish be provided.

A wave-shaped bent wire segment produced according to the invention is preferably used subsequently for the production of a stator winding, in particular for an electrical machine for a motor vehicle (for example an alternator or a generator and / or an electric motor, in particular a drive motor). For this purpose, the wave-shaped piece of wire is inserted directly or via a dummy (for example, as described in EP 1 974 443 B1) into the stator body or stator laminated core, wherein the grooves or receiving spaces can be located both inside and outside. It is preferably provided that a plurality of such wave-shaped bent wire segments are stacked in the grooves or receiving spaces of the stator body in the radial direction one above the other (see, for example.

Fig. 16 of EP 1 974 443 B1) in order to fill the available receiving spaces for the stator winding as compact as possible and to achieve a high degree of filling (especially in the case of limited space and / or high power requirements is the requirement of a high degree of filling). This is facilitated by the use of rectangular wire (as explained in more detail below). The electrical machine is preferably an internal rotor, which may in principle also be an external rotor.

It is preferably provided that the molding tools of the device according to the invention have a bearing section for the mounting or fastening on the linear guide and a receiving section with a receiving area formed thereon, wherein the bearing section and the receiving section are provided by means of spherical bearings. mounted rotary joint or the like are connected. The rotation or the rotation can be done largely frictionless.

The receiving areas on the forming tools are preferably formed as grooves, which can receive the form-fitting wire segment to be formed at the appropriate locations.

The non-slip fixation of the wire segment in the receiving areas of the molds can be done by means of attachable pressure plates. The releasable attachment of the pressure plates can, for example, by means of screwing or the like.

The molding tools may further be formed with at least one molding section for forming transitions (i.e., turn portions) in the waveform to be formed.

At least some of the molding tools may be formed with spacers which, when moving together, define a defined end position for the molding tools, in particular by limiting the rotational movement and / or the collapsing movement. With the help of such spacers can be defined during the bending process, the angle of rotation of the molds or their receiving portions and along the linear guide a distance to which the molds are moved together or -schiebbar be defined.

Preferably, the device according to the invention also has at least one drive for active twisting and / or shifting (i.e., moving together and moving apart) of the forming tools. The drive can actively drive any or all molds via a suitable drive mechanism. The drive is, for example, an electric, hydraulic or

pneumatic rotary or linear drive (motor).

The method according to the invention for producing wave-shaped bent wire segments comprises at least the following steps: - Providing a device, in particular a device according to the invention, which (at least) has a linear guide and a plurality of longitudinally displaceable and rotatably mounted molding tools;

- Locating at least one to be formed or undeformed, in particular straight wire segment to the molds, to which they may be formed according to previous explanations with receiving areas;

- Producing the waveform, including the molds twisted in opposite directions together with the wire segment fixed thereto and simultaneously along the linear guide, in particular to a predetermined distance, moved together or pushed together, d. H. The initially spaced apart molds are rotated in opposite directions with distance shortening and thereby form the recorded wire segment in a working or forming step wavy.

Preferably, the bending or forming process takes place in the cold state, d. H. the wire segment is at about room temperature. Furthermore, the wire segment can have insulation, as already explained above. The invention is also suitable for bending wires with non-round cross sections. The wire segment may, for example, have a rectangular cross-section (so-called rectangular wire).

The invention will be explained in more detail below by way of non-limiting example with reference to an embodiment shown in the figures. The features shown in the figures and / or explained below may be, even detached from concrete feature combinations, general features of the invention and further develop the invention.

FIGS. 1 to 3 show a top view of a device according to the invention and the sequence of bending a wire segment.

FIG. 4 shows an enlarged view of a section through a molding tool of the device, according to the sectional profile (CC) indicated in FIG. 1. 1 shows a device 100 according to the invention for wave-shaped bending of conductor wire 200. The reusable device 100 has a linear guide 110 formed as a rail, on which a plurality of mold elements or molding tools 120 (120a to 120f) are mounted in a spill-like or cart-like manner. The number of six forming tools 120 shown is only an example. The linear guide 1 10 is, for example. On a base plate, a support frame or the like arranged. Instead of a single linear guide 1 10 may be provided in an equivalent manner, a plurality, in particular arranged in parallel, linear guides.

The molding tools 120 are each formed with a receiving portion 123 for the lead wire 200 to be molded. As shown in Fig. 4, the molding tools 120 have a bearing portion 121 (eg, a roller) for mounting on the linear guide 1 10 and a receiving portion or a mold plate 122 with the receiving portion 123, wherein the bearing portion 121 and the receiving portion 122nd are connected without tilting means of ball-bearing pivot 126. The axis of rotation is denoted by L (as can be seen in FIG. 4, the wire axis and the axis of rotation intersect). The storage on the rail 1 10 can for example be done by means of rollers or the like. The molds 120 and their receiving portions 122 are thus longitudinally or linearly displaceable and rotatably mounted on the rail 1 10 about the axis L. Except for the first mold 120a and the last mold 120f all interposed mold 120b to 120e are identical or mirror-symmetrical and arranged alternately mirror-inverted with respect to the wire axis.

In order to carry out a bending operation, the lead wire 200 to be bent, which is typically already provided with an insulating varnish, is inserted into the mutually aligned receiving areas 123 of the molding tools 120, as shown in FIG. The wire 200 may, for example, be removed from a roll, straightened by means of a straightening device, and then cut to length. The wire 200 has, for example, a diameter of 2.0 mm to 4.0 mm. It is preferably a rectangular wire (wire with rectangular cross-section). Preferably, it is a copper wire, in particular insulated copper wire. The substantially straight piece of wire or wire segment 200 can be inserted, for example, from above into the molding tools 120 or introduced or threaded in the axial direction. The receiving areas 123 are formed with a profiling, for example a groove or the like. The fixing of the inserted wire segment 200 takes place with the aid of pressure plates 127 (see FIG. 4) in order to prevent buckling and / or slippage of the wire 200 during bending. The pressure plates 127, not shown in FIGS. 1 to 3, can, for example, by means of

Screw 128 are fixed, whereby the wire 200 is clamped in the associated profiles or grooves of the receiving areas 123. Between the lead wire 200 and the receiving areas 123 there are transitional passages. Furthermore, the receiving areas 123 are polished so as not to damage the wire surface or the insulating lacquer during insertion or during the subsequent bending process.

Before, during or after the insertion or threading of the wire segment 200, the molding tools 120 are brought to each other at predetermined distances, for example. Uniform distances (as shown in Fig. 1). The correct distances result mathematically from the processing of the waveform to be produced.

Starting from the initial state shown in FIG. 1, wherein the wire segment 200 to be formed or bent is fixed at several locations on the forming tools 120, the forming tools 120 are now moved together or pushed together along the rail 110, with adjacent ones being rotated Forming tools 120 are rotated in opposite directions, as illustrated in Fig. 2 by the bow arrows a and b (Fig. 2 shows an intermediate state). The pushing together, whereby the distance between the individual dies 120 decreases, and the twisting of the dies 120 takes place simultaneously. Simultaneous pushing and twisting can be done continuously. It is also conceivable that the pushing together and twisting is carried out alternately in substeps. By the linear pushing together and opposite rotation of the molds 120, the wire segment 200 Waveform transformed or bent and finally assumes the waveform shown in Fig. 3, as explained in more detail below.

In the embodiment shown, the first (left) mold 120a is stationary and can only perform a rotational movement. The force for pushing and twisting the dies 120 can be applied differently. The molds 120 may, for example, active, d. H. by means of a suitable drive, it being sufficient that only the last (right) mold 120f is actively moved. Furthermore, the rotational movement of the dies 120 may be active, i. H. by means of suitable drives (where all or only individual dies 120 can be rotationally driven), or passively, d. H. as a result of the pushing together. For the passive rotation of the desired direction of rotation or the desired direction of rotation, for example. By acting in the opposite direction of rotation turnstile can be specified. Another possibility is to actively twist individual molds 120 (for example the first and last but one) or also all molds 120, wherein the distances between the molds 120 inevitably decrease and the molds 120 passively converge towards each other along the linear guide 110 move. Preferred is a combination of active compression or contraction and active twisting of all or individual

Molded 120 provided.

The bending operation is completed when the dies 120 have reached the desired end position, as shown in Fig. 3 (Fig. 3 shows the final state). The molds 120 may be formed with spacers 129 a and 129 b that ensure a desired end position and a desired end clearance between the dies 120. In the exemplary embodiment shown, the spacers 129a are rounded, so that they can roll off without tilting when they are hit (see below).

3 further shows the finished bent wire segment 200 having straight and parallel sections 210 and transitions 220 in the form of arcuate transition sections. The straight sections 210 become used later in the grooves of the stator (as shown for example in Fig. 1 of EP 1 974 443 B1) and can therefore also be referred to as groove sections or segments. The two straight expiring wire ends are used for electrical contacting (for the production of a wave winding, for example, the end of a first wave-shaped wire segment 200 with the beginning of a second wave-shaped wire segment 200 contacted). In order that the turning sections 220 are not bent freely but shaped in a defined manner, the forming tools 120 are further formed at the end of the groove-like receiving areas 123 with mold sections 124 and / or 125, with which the turning sections 220 are formed, as can be clearly seen Fig. 2 shows. The turning or

Foot portions 220 have blunt tips 225 created by bending the wire 200 about the mold sections 124.

The spacers 129a designed as cantilevers also act as lever arms, which come to a stop after a certain assembly travel and angle of rotation on the adjacent forming tools 120 and then allow the wire 200 to be clamped along the mold sections 124 and / or 125 during further movement and twisting, so that the wire 200 fully rests and does not bulge. The fixation of the wire 200 by means of the attachable pressure plates 127 ensures the bending of the turning sections 220

Maintaining a consistent unwind length by preventing slipping and buckling. Preferably, the pressure plates 127 are formed such that the forming of the turn portions 220 is not affected, so that in these areas of the wire to be formed or bent 200 is only guided but not clamped.

Each mold 120 thus produces a groove portion 210 and a portion of adjacent transition sections 220. The required number of molds 120 thus results from the number of groove sections 210 to be produced. The adjacent forming tools 120 forming a turn section 220 can also be referred to as a pair of mold tools. With a pair of mold tools, two groove sections 210 and a turning section 220 connecting these groove sections 210 can be produced. As previously explained, the forming tools 120 of a pair of molds have an opposite sense of rotation.

After the bending process has ended (FIG. 3), the pressure plates 127 are released and the now wave-shaped wire segment 200 can be removed (if necessary, the device 100 is previously relaxed). A possible springing up of the waveform can be achieved by so-called over-bending in the

Bending process can be compensated (starting from the position of the mold 120 shown in Figure 3, these can be slightly over-twisted until the abutment of the projection-like spacers 129b, which then leads to overstretching of the wire 200). It is preferably provided that the forming or bending process takes place in one plane, ie. H. that this is 2-dimensional. In a downstream process step, the 2-dimensionally shaped wave-shaped conductor wire segment 200 can still be bent around prior to insertion into the stator.

The invention is not limited to the waveform shown in the figures. It goes without saying that other waveforms can be produced by appropriate modification of the mold 120. The receiving sections or molding tool plates 122 of the molding tools 120 are preferably designed to be exchangeable. Furthermore, the device 100 or the molding tools 120 can be designed such that a plurality of wire segments 200 can be bent simultaneously.

REFERENCE CHARACTERS

100 device

1 10 linear guide

120 mold

121 bearing section

122 receiving section

123 recording area

124 mold section

125 mold section

126 swivel joint

127 pressure plate

128 screw connection

129 spacers

200 pieces of wire

210 groove section, straight section

220 transition, turning section

225 tip

L rotation axis

a sense of rotation

b direction of rotation

Claims

claims

1. Device (100) for producing a wavy bent wire segment (200), in particular for use as a stator winding in an electrical machine, with a linear guide (110) and with a plurality of mold tools (120), which is longitudinally displaceable and rotatable on the linear guide (110 ) and in each case have a receiving region (123) for fixing the wire segment (200) to be bent, wherein the forming tools (120) in order to bend the wire segment (200) fixed thereto in a wave form can be rotated in opposite directions (a, b) and at the same time along the linear guide (110) are movable together.

2. Device (100) according to claim 1, characterized in that the molding tools (120) have a bearing portion (121) for mounting on the linear guide (110) and a receiving portion (122) with the receiving area (123), wherein the bearing portion (121) and the receiving portion (122) are connected by ball-bearing pivot (126).

3. Device (100) according to claim 1 or 2, characterized in that the receiving areas (123) on the forming tools (120) are formed as grooves.

4. Device (100) according to one of the preceding claims, characterized in that the non-slip fixing of the wire segment (200) in the receiving areas (123) of the molding tools (120) by means of attachable pressure plates (127).

5. Device (100) according to one of the preceding claims, characterized in that the molding tools (120) are further formed with at least one shaping portion (124, 125) for forming transitions (220) in the waveform.

6. Device (100) according to one of the preceding claims, characterized in that the molding tools (120) with spacers (129a, 129b) are formed, which specify an end position.

7. Device (100) according to one of the preceding claims, characterized in that it comprises at least one drive for rotating and / or moving the forming tools (120).

8. A method for producing a wavy bent wire segment (200), in particular for use as a stator winding in an electrical machine, comprising:

- Providing a device (100) having a linear guide (1 10) and a plurality of longitudinally displaceable and rotatably mounted molding tools (120);

- Fixing the wire segment (200) to be formed on the molding tools (120);

- Making the waveform, including the molds (120) together with the wire segment fixed thereto (200) in opposite directions twisted (a, b) and at the same time along the linear guide (1 10) are moved together.

9. The method according to claim 8, characterized in that the wire segment (200) has an insulation.

10. The method according to claim 8 or 9, characterized in that the wire segment (200) has a rectangular cross-section.