EP-4741148-A2 - METHOD FOR PRODUCING A HYBRID COMPONENT

EP4741148A2EP 4741148 A2EP4741148 A2EP 4741148A2EP-4741148-A2

Abstract

The present invention relates to a hybrid component (1) and a method for manufacturing a hybrid component (10) comprising at least one, in particular solid, metal component (11) which is at least partially overmolded with plastic, in particular a copper component, preferably a conductor for conducting electric current. The method is characterized by the following steps: a) Processing a surface area (13) of the metal component (11) with a laser beam, in particular introducing nano- and/or microstructures into this surface area (13) with the laser beam, b1) Mounting and shrinking a heat shrink tube (14) onto the machined surface area (13) of the metal component (11) and then overmolding the mounted and shrunk heat shrink tube (14) with plastic, or b2) Applying, in particular, latently reactive adhesive to the machined surface area (13) of the metal component (11) and then overmolding the applied adhesive with plastic.

Inventors

Funk, Johann
Heitbrink, Alexander

Assignees

Erwin Quarder Systemtechnik GmbH

Dates

Publication Date: 20260513
Application Date: 20230907

Claims (8)

Method for manufacturing a hybrid component (10) with at least one, in particular solid, metal component (11) which is at least partially overmolded with plastic, in particular a copper component, preferably a conductor for conducting electric current, characterized by the following steps: a) Processing a surface area (13) of the metal component (11) with a laser beam, so that nano- and/or microstructures are introduced into this surface area (13), b) Mounting and shrinking a heat shrink tube (14) onto the machined surface area (13) of the metal component (11) with the heat shrink tube (14) in contact with the metal surface, and then overmolding the mounted and shrunk heat shrink tube (14) with plastic with the plastic in contact with the heat shrink tube (14).
The method according to claim 1, characterized in that the nano- and/or microstructures cause an increase in the surface area in the surface region (13) and/or have recesses comprising undercuts and/or barbs,
Method according to one or more of the preceding claims, characterized in that the metal component (11) has edges in the surface area (13) processed by the laser beam, onto which the shrink sleeve (14) is mounted and shrunk, and that these edges are rounded off by mechanical processing before the surface area (13) is processed with the laser beam.
Method according to one or more of the preceding claims, characterized in that the metal component (11) is an elongated component and that the machined surface area (13) is a continuous strip circumferentially at an angle, in particular transversely to its longitudinal extent.
Method according to one or more of the preceding claims, characterized in that the metal component (11) has an inwardly directed taper or constriction on opposite sides in the machined surface area (13).
Method according to claim 5, characterized in that the shrink tubing (14) is mounted and shrunk in the area of the tapering or constriction.
Method according to one or more of the preceding claims, characterized in that the overmolding takes place within an injection molding process in an injection molding tool into which the metal component (11) is inserted for this purpose.
Method according to one or more of the preceding claims, characterized in that the machined surface area and/or the injection mold is heated during the overmolding of the shrink tubing with the plastic, in particular by means of an induction heater, by means of a laser, by means of a heat lamp, by means of an oven or by means of a resistance heater.

Description

The present invention relates to a method for manufacturing an (injection-molded) hybrid component comprising at least one, in particular solid, metal component, which is overmolded, at least partially, with plastic, in particular in a fluid-tight manner. The metal component, preferably made of copper, can in particular be a conductor for conducting electric current. Such (injection-molded) hybrid components made of several materials, namely plastic and metal components (e.g., conductive traces), are used in a wide variety of technical fields. For example, in electric motors, they serve as components that contact the stator winding and through which the three phase leads of the electric motor are routed to the outside. In components where a metal part is overmolded during the injection molding process, there is a risk of leaks developing between the metal part and the surrounding plastic during subsequent use. In particular, temperature fluctuations during later use can cause micro-gaps between the plastic and the metal due to differing coefficients of thermal expansion of the materials involved. Depending on the application, such micro-gaps can then lead to undesirable leaks, corrosion, etc. From the DE 10 2006 001 340 It is known to shrink a heat shrink tube onto an insert and then overmold the insert in this area to achieve sufficient sealing. In practice, however, it has been shown that the resulting tightness is insufficient or cannot meet increased requirements. Based on this, the object of the present invention is to further develop the manufacturing process mentioned at the outset for producing such a hybrid component with a metal component overmolded with plastic. This problem is solved by a method having the features of claim 1. Accordingly, the method according to the invention is characterized by the following features: a) Processing a surface area of the metal component by applying a laser beam to it, so that nano- and/or microstructures are introduced into this surface area, in particular nano- and/or microstructures that increase the surface area in the surface area (compared to an unprocessed or unstructured surface of the surface area) and/or have undercuts, depressions and/or barbs, b) Mounting and shrinking a heat shrink tube onto the machined surface area of the metal component with (direct) contact of the heat shrink tube to the metal surface of the metal component and then overmolding the mounted and shrunk heat shrink tube with plastic with (direct) contact of the plastic to the heat shrink tube. The applicant has surprisingly discovered that the tightness and longevity of the seal between the metal component and the overmolded plastic can be significantly increased if the surface area of the metal component to be overmolded during the injection molding process is first treated with a laser beam, as described, and, unlike in the prior art, the heat shrink tubing to be overmolded is only then shrunk onto the surface area to be treated. Treating the surface with the laser beam significantly increases the sealing effect, presumably due to an improved or interlocking fit of the heat shrink tubing to the metal component. The processing of the surface area or the introduction of the described nano- and/or microstructures into the surface can, as an alternative to bombarding the surface area with a laser beam, also be carried out by other physical and/or chemical nano- or microstructuring methods, for example by chemical etching. Regarding the metal component of the hybrid component, it may, moreover, have (external) edges in the machined surface area onto which the heat shrink tubing is mounted and shrunk. According to an important embodiment of the invention, it has been shown that rounding these edges by mechanical processing prior to machining the surface area is also advantageous. In this way, for example, a more homogeneous stress distribution can be achieved after overmolding, and notch effects can be minimized. The metal component can be an elongated component, and the machined surface area can be a continuous strip extending circumferentially, particularly perpendicular to its longitudinal extent. This strip can advantageously extend circumferentially along the adjacent (outer) sides of the metal component. Furthermore, the metal component may have an inwardly directed taper or constriction on opposite sides in the machined surface area. In this case, the heat shrink tubing is advantageously mounted and shrunk onto the area of the taper or constriction. As far as overmolding with the plastic is concerned, this is expediently carried out in particular as part of an injection molding process in an injection molding tool into which the metal component is inserted for this purpose. Furthermore, to improve the sealing effect in particular, the machined surface area and/or the injection mold can be heated during the overmolding of the shrink tubing with the plastic, especially by means of