Method for producing a winding wire for an electrical machine for an at least partially electrically operated motor vehicle by means of a production device

Abstract

The invention relates to a method for producing a winding wire (10) for an electrical machine for an at least partially electrically powered motor vehicle by means of a production device (12), comprising the steps of: providing a shaped wire (14, 16, 18, 20) rounded on one side; applying an insulation layer to the shaped wire (14, 16, 18, 20); combining at least one further shaped wire (14, 16, 18, 20) with the shaped wire (14, 16, 18, 20) to form an intermediate product (22); twisting the intermediate product (22); and forming the twisted intermediate product (22) to form the winding wire (10). The invention further relates to a production device (12).

Description

[0001] The invention relates to a method for producing a winding wire for an electrical machine for an at least partially electrically operated motor vehicle by means of a production device according to the applicable patent claim 1. Furthermore, the invention relates to a corresponding production device for producing a winding wire.

[0002] High efficiency is also a goal in automotive engineering for high-power-density electric machines. Stack windings, such as hairpin stators, present the technical problem that the copper conductors run parallel in the slots. This increases the resistance when AC power is applied, resulting in a negative effect from the current change toward the slot head, causing the current density in the stack winding conductors to change from the slot base to the slot head. This results in different losses in the individual conductors and stack winding slots.

[0003] DE 25 008 19 A1 discloses a bar winding with twisted individual conductors for electrical machines, wherein the unevenness on the narrow sides of the bar winding consisting of associated individual conductors and bare individual conductors is filled with a pressed-on synthetic resin mica putty and covered with an electrically conductive strip, wherein the electrically conductive strip is electrically connected to the bare individual conductors of the bar winding.

[0004] EP 2 239 828 A2 describes a coil with a core consisting of a winding of turns, the coil being impregnated with epoxy resin after assembly. Each turn consists of a copper conductor insulated along the length of each winding by a primary insulator. The winding of turns is covered with a secondary insulator, with the primary insulator and the secondary insulator containing polyether ether ketone. The primary insulator consists of a polyether ether ketone matrix enclosing mica inclusions.

[0005] The object of the present invention is to provide a method and a manufacturing device by means of which an electrical machine with a high degree of efficiency can be achieved.

[0006] This object is achieved by a method and a manufacturing device according to the independent patent claims. Advantageous embodiments are specified in the subclaims.

[0007] One aspect of the invention relates to a method for producing a winding wire for an electrical machine for an at least partially electrically powered motor vehicle using a production device. A formed wire rounded on one side is provided. An insulation layer is applied to the formed wire. At least one further formed wire is combined with the formed wire to form an intermediate product. The intermediate product is twisted, and the twisted intermediate product is formed into the winding wire.

[0008] In particular, the twisting of the conductors of a slot is carried out, in particular by so-called Röbel bars, which can reduce the corresponding losses of the electrical machine.

[0009] In particular, the forming wires can be deformed during the drawing process. This results in lower degrees of deformation during subsequent forming of the composite forming wire and thus less stretching / deformation of the coating, especially between the individual forming wires. After the stranding process, the joined forming wires initially have an interrupted cylindrical shape on the outside. This has the advantage that the twisted inner contact surfaces between the forming wires can be brought into the final geometry with a lower degree of deformation during subsequent forming. Furthermore, gentle precision forming into the composite forming wire can be achieved using driven rollers. This prevents damage to the coating due to relative movement or excessive friction. In particular, a process combination of unwinding rollers and rolled profiles for final forming can preferably be provided.This increases component quality, as incremental unwinding creates at least two opposing, straight workpiece edges, ensuring the twist angle from the stranding is maintained. This results in low workpiece stress and deformation. Furthermore, a continuously running process chain for large-scale implementation of twisting technology for the production of delicate rod wires can be provided, which has particular potential for cost and time savings. The application area of ​​the twisted rod wires according to the invention can be realized, for example, for I-PIN, Hair-PIN, and wave windings, as well as for single-tooth and distributed windings. Furthermore, advantages in terms of the winding ratio, as well as increased power density and temperature resistance of the electrical machine, can be observed.

[0010] Furthermore, a final inline insulation coating can be optionally provided. This has the advantage of achieving greater functional reliability, as partial thinning of the coating is compensated for by deformation of the formed wires.

[0011] In other words, the invention proposes a manufacturing method for twisted, shaped winding wires that can be used, for example, for a hairpin winding. This method is particularly suitable for large-scale production and allows continuous production. In particular, a manufacturing method is proposed in which the wires are first formed into a basic shape for joining, for example, four partial circle sections, then insulated, for example using varnish, then joined, twisted in the basic shape, and only then, after twisting in the joined shape, are they formed into a final shape of the conductor bars, for example via an intermediate form or in several steps with intermediate steps.

[0012] Optionally, the composite can be further insulated in its final form. U- and S-shaped hairpins can also be created using such manufactured wires. Clamping tools are preferred for bending these wires, or compressive stress can be applied during bending to prevent splitting.

[0013] Thus, the finished winding wire or conductor wire represents a kind of composite, although it is still a kind of composite of the individual formed wires, which in turn are twisted together.

[0014] According to an advantageous embodiment, the winding wire is formed into a substantially cuboidal, in particular rectangular, shape during the forming process. In particular, a substantially rectangular winding wire can thus be provided, which can then be reliably used, for example, for a stator of an electrical machine.

[0015] It is also advantageous if the intermediate product is assembled as a wire rod. This provides a simple intermediate product that can be reliably formed later. In particular, the wire rod can be reliably used for series production.

[0016] It has also proven advantageous to insulate the winding wire again. In particular, this provides additional insulation after forming, for example, by means of a varnish. This enables reliable provision of the winding wire for an electrical machine.

[0017] A further advantageous embodiment provides for at least three formed wires, in particular four formed wires, to be combined to form the intermediate product. Thus, the winding wire can comprise, in particular, four formed wires. These can then be reliably combined to form the winding wire, which can then be reliably used in an electrical machine.

[0018] A further advantageous embodiment provides for the forming to be carried out incrementally on one side. In particular, for example, after the individual forming wires have been brought together, a first side of the intermediate product can be formed first, then a second side of the intermediate product can be formed, then a third side of the intermediate product can be formed, and then a fourth side of the intermediate product can be formed. Alternatively, for example, a first side and an opposite second side can be formed in a single step, and in a second step, a third and an opposite fourth side can be formed accordingly. This allows for low workpiece stress and deformation during forming.

[0019] It is also advantageous if the formed wire is provided as copper wire. Copper wire, in particular, has proven to be very reliable in automotive and electrical machine construction, thus providing a reliable winding wire.

[0020] A further advantageous embodiment provides for the forming to be carried out using unwinding rollers. In particular, the manufacturing device can thus, for example, have the corresponding unwinding rollers. This can improve the component quality, particularly through incremental unwinding, which ensures, in particular, that the twist angle from the stranding process is maintained. This also allows for low workpiece stress and deformation.

[0021] A further aspect of the invention therefore also relates to a manufacturing device for producing a winding wire for an electric machine for an at least partially electrically powered motor vehicle, wherein the manufacturing device is designed to carry out a method according to the preceding aspect. In particular, the method is carried out by means of the manufacturing device.

[0022] Advantageous embodiments of the method are to be regarded as advantageous embodiments of the manufacturing device.

[0023] Further advantages, features, and details of the invention will become apparent from the following description of preferred embodiments and from the drawing(s). The features and feature combinations mentioned above in the description, as well as the features and feature combinations mentioned below in the description of the figures and / or shown alone in the figures, can be used not only in the respective combinations specified, but also in other combinations or on their own, without departing from the scope of the invention.

[0024] Showing: Fig. 1 A schematic view of a manufacturing method for producing a winding wire; and Fig. 2 A schematic plan view of a method for producing a winding wire.

[0025] In the figures, identical or functionally identical elements are provided with the same reference symbols.

[0026] Fig. 1 shows a schematic view of an embodiment of a method for producing a winding wire 10.

[0027] In particular, the Fig. 1 thus shows a method for producing the winding wire 10 for an electric machine for an at least partially electrically operated motor vehicle by means of a production device 12.

[0028] Fig. 1 shows, in particular, four steps S1 to S4. In a first step S1, a one-sidedly rounded shaped wire 14, 16, 18, 20 is provided. In a next step, an insulation layer (not shown) is applied to the shaped wire 14, 16, 18, 20. Then, at least one further shaped wire 14, 16, 18, 20 is combined with the shaped wire 14, 16, 18, 20 to form an intermediate product 22, as shown in the first step S1.

[0029] In the present exemplary embodiment, it is shown in particular that in particular three, in this case in particular at least four, forming wires 14, 16, 18, 20 are provided. In this case, in particular, a first forming wire 14, a second forming wire 16, a third forming wire 18, and a fourth forming wire 20 are combined to form the intermediate product 22.

[0030] In a second step S2, the intermediate product 22 is then twisted 24.

[0031] In the third step S3, a first forming step of the twisted intermediate product 22 is shown. In particular, an incremental one-sided forming takes place.

[0032] In the fourth step S4, the finished winding wire 10 is again shown.

[0033] The Fig. Figure 1 shows, in particular, that during the forming process, the winding wire 10 is formed into a substantially cuboid shape, in particular a rectangular shape. Furthermore, it is shown that the intermediate product 22 is combined to form a wire rod. In an optional step, the winding wire 10 can be insulated again, for example, after the fourth step S4.

[0034] Furthermore, it can be provided, in particular, that the formed wire 14, 16, 18, 20 is provided based on a wire drawing process. Furthermore, it can be provided that the formed wire 14, 16, 18, 20 is provided as a copper wire.

[0035] Furthermore, it can be provided that the forming is carried out by means of rolling rollers.

[0036] Fig. 2 shows a schematic plan view of the manufacturing process, as already described in Fig. 1. In particular, the top view of the formed wires 14, 16, 18, 20 and the finished winding wire 10 is shown accordingly.

[0037] In particular, the Fig. 1 and the Fig.2, that, for example, in a first sub-step, a continuous basic shaping of the individual copper wires is carried out by wire drawing operations, preferably to form a polygonal, but one-sided rounded formed wire 14, 16, 18, 20. In a second sub-step, the insulation layer is applied, for example PEEK by extrusion, for example via forming rollers, or PAI using insulating varnish as a forming stripper. In a third sub-step, several coated formed wires 14, 16, 18, 20 are brought together and twisted in the rolling stand to form a wire rod that is preferably round on the outside. The procedure can be viewed in particular as analogous to a stranding process. For this purpose, the wire ends are pointed with a tool, pushed together through the driven rolling tool, gripped in a collet and drawn to start the process, as in the drawing process. After a sufficient drawing length has been reached, the corresponding rolling stages take over the feed.

[0038] A fourth sub-step can then again be the incremental one-sided deformation by inline precision forming with driven tools, preferably by rolling out rolls to form an externally rectangular composite formed wire. To avoid damage to the insulation layer during forming, the feed of the composite wire and the rolling speed of the tools are synchronized with each other, i.e., when the tools impact, there is hardly any movement or only a deep movement between the opposing tools and the workpiece. A fifth sub-step can be the all-round final forming by almost enclosing rolling tools. A possible sixth sub-step is optional, whereby in particular a final external insulation coating of the winding wire 10 can be carried out.

[0039] For contact during processing, the wire ends can be stripped from the outside, preferably in a contactless manner, for example by laser ablation. To ensure process-reliable joint preparation, the contact surfaces of the formed wires 14, 16, 18, and 20 are also insulated from each other toward the rod end. For this purpose, the composite formed wire is spliced ​​and the coating is also removed from the inner contact surfaces. To prevent splicing at the bending radii when bending the composite formed wire, particularly similar to so-called bending pants, a compressive stress superposition is used in addition to wide-enclosing bending tools. List of reference symbols 10 winding wire 12 Manufacturing device 14 First forming wire 16 Second forming wire 18 Third forming wire 20 Fourth forming wire 22 Intermediate product 24 twist S1-S4 steps of the procedure QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 25 008 19 A1

[0003] EP 2 239 828 A2

[0004]

Claims

[1] Method for producing a winding wire (10) for an electrical machine for an at least partially electrically operated motor vehicle by means of a production device (12), comprising the steps: - providing a forming wire (14, 16, 18, 20) rounded on one side; - applying an insulating layer to the forming wire (14, 16, 18, 20); - combining at least one further forming wire (14, 16, 18, 20) with the forming wire (14, 16, 18, 20) to form an intermediate product (22); - twisting the intermediate product (22); and - Forming the twisted intermediate product (22) into the winding wire (10). [2] Method according to claim 1, characterized by that during the forming process the winding wire (10) is formed into a substantially cuboid shape, in particular a rectangular shape. [3] Method according to claim 1 or 2, characterized by that the intermediate product (22) is brought together as a wire rod. [4] Method according to one of the preceding claims, characterized by that the winding wire (10) is insulated again. [5] Method according to one of the preceding claims, characterized by that at least three forming wires (14, 16, 18, 20), in particular four forming wires (14, 16, 18, 20), are combined to form the intermediate product (22). [6] Method according to one of the preceding claims, characterized by that the forming is carried out incrementally on one side. [7] Method according to one of the preceding claims, characterized by that the forming wire (14, 16, 18, 20) is provided on the basis of a wire drawing process. [8] Method according to one of the preceding claims, characterized by that the forming wire (14, 16, 18, 20) is provided as a copper wire. [9] Method according to one of the preceding claims, characterized by that the forming is carried out by means of rolling rollers. [10] Manufacturing device (12) for producing a winding wire (10) for an electrical machine for an at least partially electrically operated motor vehicle, wherein the manufacturing device (12) is designed to carry out a method according to one of claims 1 to 9.

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