BATTERY HOUSING AND USE THEREOF

Abstract

The present invention relates to a battery housing for receiving one or more battery modules, in particular for an electrically powered vehicle or a vehicle having a hybrid drive, comprising a box having a frame and a base, which provides an interior space for receiving the battery module or modules, at least one mounting support which is connected at least in certain portions, on that side of the frame which faces away from the interior space, to the frame of the box and which serves for the releasable connection of the battery housing to a vehicle, and a cover for closing the box, wherein the frame, the base, the mounting support or the cover of the battery housing is manufactured from a steel sheet which has a microstructure comprising ferrite and martensite and which is provided with a zinc-based coat on one or both sides.

Claims

1. A battery housing for receiving one or more battery modules, in particular for an electrically powered vehicle or a vehicle having a hybrid drive, comprising: a box having a frame and a base, which provides an interior space for receiving the battery module or modules, at least one mounting support which is connected at least in certain portions, on that side of the frame which faces away from the interior space, to the frame of the box and which serves for the releasable connection of the battery housing to a vehicle, a cover for closing the box, wherein at least one of the frame, the base, the mounting support and the cover of the battery housing is manufactured from a steel sheet which has a microstructure comprising ferrite and martensite, wherein the steel sheet has a microstructure comprising at least 65% of ferrite and martensite, wherein there is at least 20% of ferrite and at least 5% of martensite, wherein up to 35% of at least one of bainite, pearlite, cementite and residual austenite can be present, and which is provided with a zinc-based coat on at least one side.

2. The battery housing as claimed in claim 1, wherein the battery housing also comprises an underride guard which is arranged below the base of the box, wherein the underride guard is manufactured from a steel sheet which has a microstructure comprising ferrite and martensite and which is provided with a zinc-based coat on at least one side.

3. The battery housing as claimed in claim 2, wherein the underride guard is releasably connected to the battery housing.

4. The battery housing as claimed in claim 3, wherein the steel sheet has a microstructure comprising at least 60% of ferrite and at least 5% of martensite, wherein up to 35% of at least one of bainite, pearlite, cementite and residual austenite can be present.

5. The battery housing as claimed in claim 3, wherein the steel sheet has a microstructure comprising 70% to 90% of ferrite and 10% to 30% of martensite, wherein up to 20% of residual austenite can be present.

6. The battery housing as claimed in claim 3, wherein the zinc-based coat also comprises, in addition to zinc and unavoidable impurities, at least one of the elements from the group of aluminum and magnesium.

7. The battery housing as claimed in claim 3, wherein the zinc-based coat comprises at least one of 0.5% to 4% by weight of aluminum and 0.5% to 4% by weight of magnesium, the remainder being zinc and unavoidable impurities.

8. The battery housing as claimed in claim 3, wherein the zinc-based coat has an applied amount of at least 30 g/m.sup.2 per side on at least one side on the steel sheet.

9. The battery housing as claimed in claim 3, wherein the zinc-based coat has an applied amount of at least 90 g/m.sup.2 per side on at least one side on the steel sheet.

10. The battery housing as claimed in claim 3, wherein at least the frame and the base of the box are provided with an additional cathodic dip-paint coat with an applied amount of at least 10 μm per side on at least one side.

11. The battery housing as claimed in claim 9, wherein the underride guard is provided with an additional cathodic dip-paint coat with an applied amount of at least 15 μm per side on one or both sides.

12. (canceled)

13. A passenger vehicle comprising the battery housing of claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The invention is explained in more detail below with reference to drawings. Identical parts are provided with identical reference designations. Specifically:

[0022] FIG. 1a) shows a schematic side view of a battery housing,

[0023] FIG. 1b) shows a schematic plan view of the battery housing shown in FIGS. 1a), and

[0024] FIG. 1c) shows a schematic partial sectional view along the section A-A in FIG. 1b).

DESCRIPTION OF PREFERRED EMBODIMENTS

[0025] The battery housing (1) for receiving one or more battery modules (not illustrated) can be of differing configuration. According to the invention, the battery housing (1) comprises a box (2) which has a base (2.2) with a frame (2.1), in particular an encircling frame (2.1) in the form of a wall, which defines an interior space for receiving the battery module or modules (not illustrated), and a cover (not illustrated) for closing the box (2). Furthermore, at least one mounting support (3) which is arranged at least in certain portions, on that side of the frame (2.1) which faces away from the interior space, is connected to the frame (2.1) of the box and serves for the releasable connection of the battery housing (1) to a vehicle (not illustrated) via means which are not illustrated, for example screws which can be guided through corresponding openings (3.1). The mounting support (3) is arranged at least in certain portions on the outer side of the frame (2.1) of the box, in particular is substance-to-substance bonded thereto, preferably welded thereto. As shown in FIGS. 1a) and 1b), the mounting support (3) can also be arranged so as to be at least continuous on the two sides of the battery housing (1) along the frame (2.1) in the vehicle longitudinal direction (L). Alternatively or additionally and not illustrated here, the mounting support (3) can also be connected at least in certain portions to the frame (2.1) in the vehicle transverse direction (Q). The mounting support (3) can be dimensioned differently or in accordance with requirements, for example can be formed as an open or closed profile.

[0026] The box can be a constructed box (2), meaning that said box is composed of individual components, such as for example of at least one open or closed profile which can be formed in such a way that an encircling frame (2.1) is formed, or preferably of at least four profiles which have an open or closed cross section and are connected to one another in such a way that said profiles form an encircling frame (2.1), and of a plate which is connected to the frame (2.1) and which forms the base (2.2) of the box (2), said box in particular being substance-to-substance bonded. In an alternative refinement (not illustrated), the base of the box can be embodied as a deep-drawn tray.

[0027] The battery housing (1) can also comprise an underride guard (2.3) which is arranged below the base (2.2) of the box (2), in particular at a spacing from the base (2.2), see FIGS. 1a) and 1c). In FIG. 1b), shown in dashed line form, at least one reinforcing element, in this embodiment for example exactly one reinforcing element is illustrated, in the vehicle longitudinal direction (L) and/or at least one reinforcing element, in this embodiment for example four reinforcing elements are illustrated, in the vehicle transverse direction (Q) are arranged so as to run in the interior space of the box (2). Said reinforcing elements can be provided as required and thus form compartments for receiving battery modules. In this embodiment, it is for example possible for up to eight battery modules to be received.

[0028] According to the invention, at least one of the component parts and/or components, for example the frame (2.1), the base (2.2), the underride guard (2.3), the mounting support (3), the reinforcing element or the reinforcing elements (see FIG. 1b)) or the cover (not illustrated), is manufactured from a respective steel sheet which has a microstructure comprising ferrite and martensite, preferably a microstructure comprising at least 60% of ferrite and at least 5% of martensite, wherein up to 35%, in particular up to 30%, preferably up to 25%, of bainite, pearlite, cementite and/or residual austenite can be present, particularly preferably a microstructure comprising 70 to 90% of ferrite and 10 to 30% of martensite, wherein up to 20% of residual austenite can be present.

[0029] The steel sheet for the manufacture of the at least one component part (frame, base, underride guard, mounting support, reinforcing element, cover) is provided, according to the invention, with a zinc-based coat on one or both sides, wherein in particular at least one of the elements from the group of aluminum and magnesium can also be present in the coat in addition to zinc and unavoidable impurities, particularly preferably the zinc-based coat comprises 0.5 to 4% by weight of aluminum and/or 0.5 to 4% by weight of magnesium, the remainder being zinc and unavoidable impurities, further preferably the zinc-based coat comprises 1 to 2.5% by weight of aluminum and 1 to 2.5% by weight of magnesium, the remainder being zinc and unavoidable impurities. The applied amount on the steel sheet or the component part manufactured therefrom is at least 30 g/m.sup.2 per side on one or both sides on the steel sheet. For the underride guard (2.3), an applied amount of at least 90 g/m.sup.2 per side can be provided on one or both sides on the steel sheet. Prior to the manufacturing operation to form a component part, the zinc-based coat is applied to the steel sheet, for example in a conventional manner continuously in a strip coating process, preferably in a continuous melt dip coating process.

[0030] Preferably, the frame (2.1) or the components for creating the frame (2.1), the base (2.2), the mounting support (3) and the underride guard (2.3) are each manufactured from a steel sheet which has a microstructure comprising ferrite and martensite and which is provided with a zinc-based coat on one or both sides.

[0031] In the case of the preferably constructed box (2), the individual components, such as for example the components for creating the frame (2.1), the base (2.2) and optionally the mounting support (3), are connected to one another by a substance-to-substance bond, wherein a welding process is used, in particular a laser welding process or optionally a laser hybrid welding process (with filler material). The combination of microstructure, coat and joining method ensures a high quality of the component parts (2.1, 2.2) which are connected by means of weld seams, and thus the tightness of the battery housing (1). It is thus in particular possible after the box (2) has been completed with or without a mounting support (3) for at least the box (2) to be fed to a cathodic dip painting process, such that at least the frame (2.1) and the base (2.2) of the box (2) are provided with an additional cathodic dip-paint coat with an applied amount of at least 10 μm per side on one or both sides.

[0032] The underride guard (2.3) is preferably releasably connected to the battery housing (1) or to the box (2) and is preferably provided with an additional cathodic dip-paint coat with an applied amount of at least 15 μm per side on one or both sides. If no welding is used for connection of the underride guard (2.3), the zinc-based coat and/or the cathodic dip-paint coat can be applied with a high applied amount, in particular with a higher applied amount in comparison to the other component parts (2.1, 2.2, 3), which can lead to particularly good corrosion protection. In order for the connection between the underride guard (2.3) and the box (2) or battery housing (1) to be implemented in a preferably tight manner, the connection region or contact region is additionally provided with adhesive and/or sealing means, such that it is also possible here to ensure water tightness and corrosion protection against premature rusting-through. If the underride guard (2.3) is joined or connected by means of welding, it is in particular possible for the applied amounts, described for the base, of the zinc-based coat and of the cathodic dip-paint coat to be used.

[0033] The cover (not illustrated) can be manufactured from a steel sheet having the aforementioned properties. As an alternative, the cover can also be manufactured from another steel material, from a light metal, from a (fiber-reinforced) plastic or else from a mixture thereof in the form of a hybrid. For maintenance purposes, in particular for ensuring the accessibility to the interior space of the box (2), the cover is preferably releasably connected to the box (2).

[0034] The invention is not restricted to the embodiment shown, rather the individual features can be combined with one another as desired insofar as this is technically possible.