ELECTRICAL SHEET METAL PACKS FOR ELECTRIC MOTORS OR GENERATORS

Abstract

In a method for manufacturing metal bodies, e.g., stators for electric motors, a stack of sheet metal parts (14), which have thermally-curable adhesive layers provided therebetween, is guided over a mounting mandrel (11) of a tool, and/or is held by an external fixture (25). The stack is then heated to cure the adhesive layers while applying pressure thereto, thereby forming the metal body. In the course of the method, at least one of the applied pressure, the temperature of the stack, and/or the height of the stack is measured. A prescribed height of the stack is adjusted by performing a temperature-pressure control. The present system and method enables efficient and precise production of stators, is self-learning and enables the measurement, regulation and recording of all manufacturing parameters in the course of the manufacture of each individual stator. In particular, all manufacturing parameters can retrospectively be associated with an individual stator.

Claims

1. Method for the manufacture of metal bodies, in particular for the production of electrical sheet metal packs for use in electric motors, with the following steps: a) formation of a stack from a plurality of sheet metal parts (14) in a tool (1), wherein, between the sheet metal parts (14), one or both sheet metal surface(s) are provided with thermally-cured adhesive layers, and b) heating of the stack so as to cure the adhesive layers and to form the metal body, c) wherein pressure is applied to the stack in the course of the heating procedure, characterised in that: d) the tool has a mounting mandrel (11) and/or an external fixture (25), over which the sheet metal parts (14) are pushed, either individually, or as a sheet metal parts pack formed from a plurality of sheet metal parts, so as to form a stack.

2. Method according to claim 1, characterised in that the stack of sheet metal parts comprises a plurality of sheet metal parts, initially adhesively bonded together into a stack or a sub-stack, and/or held by an external fixture (25).

3. Method according to claim 1, characterised in that the stack is welded together or baked so as to form the metal body.

4. Method according to claim 1, characterised in that the stack is subjected to a baking process, wherein the stack is heated by way of a fluid, or directly or indirectly, magnetically or electrically, and is subsequently cooled, in particular actively cooled, whereby a metal body is obtained.

5. Method according to claim 4, characterised in that the stack is heated from the outside, and/or by way of the mounting mandrel.

6. Method according to claim 1, characterised in that for each stack method parameters, in particular, in the course of the baking process, one method parameter from: a) a power output for the heating of the stack (11), b) a temperature curve for the heating of the stack (11), c) a pressure, with which a stack is compressed in the course of the heating procedure, is individually dynamically adjusted, in particular so as to reduce a manufacturing time for a metal body (12).

7. Device for the execution of a method according to claim 1, comprising a tool (1) with a mounting plate (10) and a mounting mandrel 11, and/or an external fixture, for the mounting of sheet metal parts (14).

8. Device according to claim 7, characterised in that the tool (1) comprises a heating device, in particular a heating device through which fluids flow, or which is directly or indirectly, electromagnetically or electrically heated, and a cooling device, with which in particular the mounting mandrel (11), and/or the external fixture (25), can be heated and/or cooled.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0052] FIG. 1 shows a schematic representation of a stacking and packing unit, in which the sheet metal parts are held by way of a mounting mandrel; and

[0053] FIG. 2 shows a schematic representation of a stacking and packing unit, in which the sheet metal parts are held by way of a mounting mandrel and an external fixture.

[0054] In principle, the same parts are provided with the same reference symbols in the figures.

DETAILED DESCRIPTION OF THE INVENTION

[0055] FIG. 1 shows a schematic representation of a stacking and packing unit 1, in which sheet metal parts 14 are bonded together to form a metal body. The stacking and packing unit 1 comprises a support plate 10 with a mounting mandrel 11, together with a stamp 13 for purposes of exerting a pressure on the stacked sheet metal parts 14. The sheet metal parts 14 are guided over the mounting mandrel 11, either in a pre-packed manner, or individually. The mounting mandrel 11 holds the sheet metal parts 14 in the desired position. The stamp 13 is now guided over the mounting mandrel 11, and pressure is applied onto the sheet metal parts 14. At the same time, the sheet metal parts are heated (see below) so as to create the metal body. The sheet metal parts 14 preferably take the form of sheet metal lamellae, which, as described above, are baked so as to become electrical sheet metal packs for electric motors, generators, and the like.

[0056] By way of the pressure, and/or the position (height) of the stamp, the stack height is, on the one hand, controlled and monitored, and is also regulated as required. In particular, in the course of the bonding of the sheet metal parts 14 into a metal body, corrective intervention in the active bonding method can be carried out on the basis of the measured values, for example by regulation of the temperature, the duration, or the stamp pressure. In this manner, an efficient production of metal bodies can be achieved.

[0057] Various technologies are of known art for the bonding of the individual sheet metal parts 14. In particular, the sheet metal parts 14 can be welded together or adhesively bonded. For example, an epoxy coating, in particular known as baking enamel, can be provided as the adhesive.

[0058] The individual sheet metal parts 14 are bonded together to form a metal body by means of a precisely controlled heating, holding, and cooling process, in the course of which the stack of sheet metal parts 14 is held under pressure by the stamp 13. In this phase, the adhesive between the individual sheet metal parts 14 can cross-link and thus be cured. The curing procedure takes place depending on the adhesive used, for example by means of a chemical reaction, the evaporation of a solvent, or the like.

[0059] Heating is preferably carried out by way of a fluid, such as water or an oil, or directly or indirectly electromagnetically or electrically, but can also be carried out by way of other devices known to the person skilled in the art. For example, heating can also be carried out by way of heating cartridges. The heating is recorded, and/or controlled, by way of sensors.

[0060] The cooling procedure is also preferably actively controlled, and is preferably carried out by way of a fluid, in particular with a cooling liquid or a cooling gas. However, other possibilities are also known to the person skilled in the art. The cooling is recorded, and/or controlled, by way of sensors.

[0061] The bonding procedure for each individual metal body is individually monitored and documented. This means that there is a fully documented manufacturing history for each individual product.

[0062] After the metal body is baked, it is ejected from the mould by way of ejectors 12. The ejectors 12 are designed in the form of pins, and can be pushed through the support plate 10, through openings from below. If necessary, the ejectors can also be dispensed with; other suitable techniques are also known to the person skilled in the art, for example the metal body can also be removed from the mould by means of compressed air, magnetic grippers, or other means. In a preferred form of embodiment, the device has a modular structure, so that a plurality of stacking and packing units 1 can be provided, which in particular are loaded by a single stamping unit.

[0063] FIG. 2 shows a stacking and packing unit that is essentially analogous to that in FIG. 1, but the present stacking and packing unit 2 comprises, in addition to the mounting mandrel 21, an external fixture 25, by way of which the sheet metal parts 24 are held on their outside surfaces. In addition to, or as an alternative to, the mounting mandrel 21, heat or cold can be applied by way of the external fixture 25. It should be noted that in principle the mounting mandrel 21 can also be dispensed with in the form of embodiment shown in FIG. 2. After the baking procedure, the metal body is, here too, ejected by way of the ejector 22.

[0064] The transport from a stamping unit (not shown) to the stacking and packing unit 1 preferably takes place by way of an automation system (not shown), or a similar transport system, but can also be carried out manually.

[0065] By virtue of the high level of automation of the device, the processes and parameters can be tracked in a stable manner, and moreover a consistently high level of quality can be ensured.

[0066] In summary, in accordance with the invention a method is created for the manufacture of metal bodies, in particular electrical sheet metal packs for electric motors, which can efficiently, and essentially autonomously, manufacture metal bodies at a high quality and with a large throughput. The method is preferably self-learning, in that data from the production of the latest metal bodies are automatically used to optimise the method. Thus, a device for the execution of the method can be installed at a manufacturer without specific method and facility know-how. In particular, the facility can be set up and operated directly at the location at which the manufactured metal bodies are further processed.