Bottom protection device having at least one exhaust channel and power battery assembly having such bottom protection device

Abstract

The invention relates to a bottom protection device (100) for a power battery (200), comprising a protective base module (110) which can be arranged below the power battery while forming a venting space. The base module (110) has at least one shell-shaped element (130) which is arranged on the top side of the base module and which forms an exhaust channel (140) which extends on the top side and has a closed cross-section for discharging the hot gas (H) from the exhaust space, the shell-shaped element (130) is designed as a plastic-metal composite component and has at least one gas-permeable overflow region (132) within which the hot gas (H) can overflow from the exhaust space into the exhaust duct (140). The invention also relates to a power battery assembly with such a bottom protection device (100).

Description

Technical Field

[0001] The present invention relates to an underbody protection device for a power battery of a motor vehicle according to the preamble of claim 1. The present invention also relates to a power battery assembly having the underbody protection device. Background Art

[0002] The type of underbody protection device is provided for protecting a drive battery or a power battery (for electric drive) which is arranged in particular in the underbody region of a motor vehicle from external influences. In addition, such an underbody protection device can also be provided, with a corresponding design and arrangement, for the targeted discharge of hot gases which are generated within the power battery in the event of a fault (e.g. a short circuit) (venting function).

[0003] DE 10 2021 103 378 B3 describes a power battery for a motor vehicle, which has a battery housing and an exhaust gas collector arranged outside the receiving space of the battery housing and having an exhaust gas space. The so-called exhaust gas space is defined by the battery housing or the housing bottom and the so-called heat shield of the exhaust gas collector. The exhaust gas collector is designed to receive the hot gas released from the receiving space of the battery housing through the exhaust unit into the exhaust gas space and cool it there. In addition, the outlet is provided with openings that enable gas exchange between the exhaust gas space and the environment. The heat shield can additionally assume the function of bottom protection for the power battery. Summary of the invention

[0004] An object of the present invention is to provide a bottom protection device for a power battery, which is lightweight and can achieve effective exhaust of the exhaust space.

[0005] This object is achieved by the underbody protection device according to the invention according to claim 1. By means of the parallel independent claims, the invention also comprises a power battery assembly according to the invention, which comprises an underbody protection device according to the invention. Additional features of the invention are derived analogously for both inventive subjects from the dependent claims, the following description of the invention (which also explicitly includes the features described optionally and by way of example) and the drawings, wherein this shall apply to all features, also independently of a specific combination of features.

[0006] The underbody protection device for a power battery according to the present invention has a panel-like or plate-like basic module, which can also be referred to as a panel-like or plate-like basic element. The basic module is configured to be arranged below the power battery while forming an intermediate space that functions at least as a gas exhaust space.

[0007] According to the present invention, the basic module has at least one shell-shaped element arranged on the top side of the basic module, the shell-shaped element forms an exhaust channel extending on the top side (of the basic module), and the exhaust channel has a closed cross-section for discharging hot gases from the exhaust space. In addition, it is proposed that the shell-shaped element is constructed as a plastic-metal composite component and has at least one air-permeable overflow area, within which hot gases can or can overflow from the exhaust space into the exhaust channel. The top side of the basic module is the side facing or to face the power battery, which side can also be called the inner side.

[0008] Preferably, the underbody protection device according to the invention has a plurality of such exhaust ducts, which extend in particular parallel to one another. The following description applies analogously not only to underbody protection devices with only one exhaust duct, but also to underbody protection devices with a plurality of exhaust ducts.

[0009] Preferably, the exhaust duct extends in the longitudinal direction or in the transverse direction over the entire length or width of the underbody protection device. Preferably, the exhaust duct is connected directly or indirectly to the environment at at least one of its ends, wherein a cover or the like that opens in the event of overpressure may be provided at the relevant end. If, in the event of a fault, hot gases from the power battery or battery housing enter the exhaust space between the power battery or battery housing and the underbody protection device base module, the hot gases can flow or overflow into the exhaust duct through at least one gas-permeable overflow region of the shell-shaped element and then flow out through the exhaust duct into the environment. Due to the expansion that occurs here, an advantageous cooling of the hot gases is simultaneously achieved.

[0010] The shell-shaped element is not completely permeable, but only partially permeable, wherein at least one permeable area is provided, which is also referred to as an overflow area. Within the overflow area, hot gas can overflow or flow from the exhaust space into the exhaust channel. In the relevant section, the exhaust channel has a cross section that is closed on the periphery and has a partially permeable wall, which can also be referred to as a quasi-closed cross section. In other parts, that is, outside at least one overflow area, the shell-shaped element is impermeable. This achieves a rigid and stable design of the shell-shaped element on the one hand, and a purposeful flow guidance or a defined gas guidance of the hot gas on the other hand.

[0011] The shell-shaped element is a plastic-metal composite component. This means that the shell-shaped element is made of plastic, in particular thermoplastic (for example, polypropylene), or also made of fiber-reinforced plastic, in particular fiber-reinforced thermoplastic (for example, glass fiber reinforced polypropylene), and made of at least one metal component, such as a wire grid or a perforated plate (see below). The plastic used preferably has a V0-fire rating. The shell-shaped element can therefore be designed to be light and stable or designed in a lightweight structure. In addition, in order to manufacture the shell-shaped element, a common manufacturing method, such as an injection molding method, can be used. Therefore, the manufacture can be relatively simple and cost-effective. The shell-shaped element is optionally, at least partially, also formed by an organic sheet or the like. The shell-shaped element preferably has a wall thickness or thickness of 1.5 mm to 4.0 mm.

[0012] The shell element is fixed to the base module in a suitable manner. Preferably, the shell element is adhesively bonded or welded to the base module. In particular, it is proposed that the shell element and the base module are made of the same plastic, in particular a thermoplastic (for example polypropylene, in particular glass fiber reinforced polypropylene), or at least of a similar type of plastic. Preferably, both the shell element and the base module are formed of thermoplastic, which also provides the advantage of recyclability.

[0013] At least one overflow region is preferably formed by an open wire grid (this also includes wire fabric, wire mesh, wire braid, etc.) or by an open perforated plate (this is a perforated metal plate). Such a wire grid or perforated plate has perforations (exhaust perforations) which, on the one hand, allow hot gases to overflow from the exhaust gas space into the exhaust gas channel and, on the other hand, fulfill a particle retention function. The wire grid or perforated plate is preferably made of steel, i.e., made of steel wire or steel plate.

[0014] The shell-shaped element is preferably constructed or manufactured as an injection molded part, wherein in particular it is provided that the wire grid or perforated plate (see above) is integrated into the injection molded part as an overmolded or partially overmolded insert, that is to say as a wire grid insert or perforated plate insert. This means that the wire grid insert or perforated plate insert is connected to the injection-molded plastic at its edge, or the wire grid insert or perforated plate insert, which can also extend over the entire area of ​​the shell-shaped element, is overmolded with plastic in a surface-covered manner except for at least one overflow area (which remains open or is not overmolded). If the shell-shaped element has multiple overflow areas, this can be achieved by multiple overmolded wire grid inserts or perforated plate inserts or by a single overmolded wire grid insert or perforated plate insert. This shell-shaped element constructed as an injection molded part and having at least one overmolded or overmolded wire grid insert or perforated plate insert is an injection-molded-metal-hybrid plastic-metal composite component.

[0015] In the exhaust duct, there may be a plurality of supporting ribs and / or a plurality of supporting domes for supporting the shell-shaped element. The supporting ribs and / or supporting domes, which are preferably formed of plastic, in particular thermoplastic, may be components of the basic module or the shell-shaped element. In particular, it is proposed that the supporting ribs and / or supporting domes are injection-molded on the bottom side of the shell-shaped element. However, the supporting ribs and / or supporting domes may also be configured as separate components and fixed to the basic module and / or the shell-shaped element in a suitable manner. The shell-shaped element may also be fixed by these supporting ribs and / or supporting domes. The overall rigidity of the underbody protection device may also be increased by such supporting ribs and / or supporting domes.

[0016] Preferably, the shell-shaped element is configured as a trapezoidal or at least trapezoidal-like profile element or as a trapezoidal profile (hereinafter also referred to as a trapezoidal shell-shaped element), which has at least two lateral waists or sides. Such a trapezoidal shell-shaped element has many advantages. Trapezoidal shell-shaped elements are very stable due to geometric relationships and can therefore also be used as a spacer between the basic module and the power battery or battery housing. The connecting plate between the lateral waists of the trapezoidal profile can be designed so that it can also be used as a contact surface with the power battery or battery housing. The connecting plate can also have a threaded connection element or the like for fixing the bottom protection device to the power battery or battery housing. These threaded connection elements are particularly embedded or overmolded metal inserts. The extension of the lower part of the trapezoidal shell-shaped element can also be designed as a laterally protruding flange, which can be used as a joining flange, particularly a welding flange or an adhesive flange, to fix the shell-shaped element to the basic module.

[0017] Preferably, at least one overflow region is located in at least one lateral waist, in particular two lateral waists, of the trapezoidal profile element or shell-shaped element. The overflow region is formed in particular by an open wire grid or perforated plate (as described above). Such an overflow region can extend over at least half of the axial length of the shell-shaped element. Such an overflow region can be designed with constant dimensions over the axial longitudinal extension of the profile element or shell-shaped element, or it can also be designed with variable dimensions, i.e., dimensions that change over the axial longitudinal extension.

[0018] The power battery assembly according to the present invention comprises at least one power battery having a battery housing configured to receive a battery module or the like, and at least one bottom protection device constructed according to the present invention, the bottom protection device being arranged below the battery housing (while forming an exhaust space) and in particular also being fixed to the battery housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The invention is described in detail below in a non-restrictive manner with reference to the drawings. Features shown in the drawings and / or described below can also be regarded as general features of the invention independently of a specific feature combination and can improve the invention accordingly.

[0020] Figure 1 An underbody protection device according to the invention with a plurality of exhaust gas ducts is shown in a perspective top view.

[0021] Figure 2 Shown in Figure 1 Cross section of the exhaust duct on the underbody protector.

[0022] Figure 3 and Figure 2 Similarly, a cross section through the exhaust gas channel is shown at another cross-sectional area with a threaded connection point. DETAILED DESCRIPTION

[0023] exist Figure 1 The underbody protection device 100 shown in FIG. 1 has a plate-like or plate-like basic module 110, which is configured with a surrounding flange-like edge 120. The basic module 110 may have reinforcement elements and spacer elements (spacers) that are not shown. The volume enclosed by the basic module 110 and the edge 120 forms a venting space for the power battery (see FIG. 1 ). Figure 3 ).exist Figure 1 Arranged on the top side of the basic module 110 visible in FIG. 1 are a plurality of shell-shaped elements 130, which respectively form exhaust ducts 140 extending on the top side of the basic module 110, wherein the exhaust ducts 140 are arranged parallel to one another. The exhaust ducts 140 are provided for discharging hot gases H from the exhaust space, as indicated by two arrows (H, H') for one of the exhaust ducts 140. For this purpose, the shell-shaped elements 130 are configured with a gas-permeable overflow region 132, as will be described in detail below.

[0024] Figure 2The cross section of the exhaust duct 140 is shown by way of example. (The following description is similarly applicable to other exhaust ducts 140). The shell element 130 is constructed as a trapezoidal profile element, which has two lateral waists or sides 131, an upper connecting plate or top plate 133 and two lower extensions or bottom plates 135, which act as joint flanges, and the shell element 130 is bonded or welded to the basic module 110 on the joint flanges, for example. The trapezoidal shell element 130 forms an exhaust duct 140 together with the basic module 110, which has a closed, i.e. structurally completely surrounded trapezoidal cross section, wherein the channel wall formed by the shell element 130 is partially permeable to air on the cross-sectional area shown. Support ribs and / or support domes 150 for supporting the shell element 150 are arranged within the exhaust duct 140. The support ribs and / or support domes 150 can also realize a flow deflection function. In particular, support is also performed in the overflow area 132 described below.

[0025] So-called overflow regions 132 are located in the two lateral sides 131 of the shell-shaped element 130, which overflow regions, as gas-permeable wall regions, allow the hot gas H to overflow from the exhaust space into the exhaust channel 140, as in Figure 1 (see arrow H). The shell element 130 is designed as a plastic-metal composite component, wherein the air-permeable overflow area 132 is formed by an open (ie uncovered) wire grid or an open perforated plate. In particular, it is provided that this is a metallic insert (wire grid insert or perforated plate insert) which is integrated into the shell element during the injection molding production of the shell element 130, as described above.

[0026] like Figure 1 As shown, the overflow area 132 does not extend over the total length of the trapezoidal shell element 130 in the longitudinal direction of the exhaust channel 140, and is also configured along the shell element 130 with a variable dimension that changes over the axial longitudinal extension of the trapezoidal shell element 130, in particular the diameter in the height direction. This achieves a local air permeability that is adapted to the entire system. This can also be achieved by local adaptation of the perforations (exhaust perforations). The overflow areas 132 in the two waists 131 of the trapezoidal shell element 130 can be configured not only symmetrically (in the sense of identical shape and consistency), but also asymmetrically.

[0027] exist Figure 3There are threaded connection points at the cross-sectional area shown, at which the underbody protection device 100 is fixed to the battery housing 210 of the power battery 200 by means of a threaded connection. Typically, a plurality of such threaded connection points are provided along the exhaust duct 140. In the region of the threaded connection points, the basic module 110 has a dome-shaped recess 115. The connecting plate 133 is configured with a recess 134, in which a threaded connection element 136 in the form of a gasket or the like is arranged. The threaded connection element 136 can also be configured as a so-called (metallic) insert and embedded in the plastic material of the shell element 130. When the shell element 130 is connected, the threaded connection is achieved by means of a bolt 220 on the battery side and a nut 160 screwed on the bottom side. Fixing can also be achieved in other ways.

[0028] Depend on Figure 3 It can also be seen that the connecting plate 133 of the shell-shaped element 130 also acts as a contact surface and is correspondingly configured as a contact surface without a protruding screw connection element 136. Figure 3 The so-called exhaust space can be seen in FIG. 1 (see reference symbol E).

Claims

1. A bottom protection device (100) for a power battery (200), the bottom protection device having a guard plate-type basic module (110), the basic module being arranged below the power battery (200) while forming an exhaust space (E), It is characterized in that The basic module (110) has at least one shell-shaped element (130) arranged on the top side of the basic module, the at least one shell-shaped element forming an exhaust gas channel (140) extending on the top side and having a closed cross section for discharging hot gases (H) from an exhaust gas space (E), wherein the shell-shaped element (130) is constructed as a plastic-metal composite component and has at least one gas-permeable overflow area (132), within which the hot gases (H) can overflow from the exhaust gas space (E) into the exhaust gas channel (140).

2. The bottom protection device (100) according to claim 1, It is characterized in that The overflow region (132) is formed by an open wire grid or by an open perforated plate.

3. The bottom protection device (100) according to claim 2, It is characterized in that The shell-shaped element (130) is designed as an injection-molded part, wherein the wire grid or the perforated plate is integrated into the injection-molded part as an overmolded or partially overmolded insert.

4. An underbody protection device (100) according to any one of the preceding claims, It is characterized in that The shell-shaped element (130) is bonded or welded to the base module (110).

5. Underbody protection device (100) according to any one of the preceding claims, It is characterized in that A plurality of supporting ribs and / or a plurality of supporting domes (150) are present in the exhaust channel (140) for supporting the shell-shaped element (130).

6. Underbody protection device (100) according to any one of the preceding claims, It is characterized in that The shell-shaped element (130) is designed as a trapezoidal profile element with lateral waists (131), wherein at least one overflow region (132) is located in at least one lateral waist (131).

7. The bottom protection device (100) according to claim 6, It is characterized in that The overflow region (132) is configured with variable dimensions.

8. The bottom protection device (100) according to claim 6 or 7, It is characterized in that The connecting plates (133) are simultaneously designed as contact surfaces between the lateral waists (131).

9. The bottom protection device (100) according to claim 8, It is characterized in that The connecting plate (133) has a threaded connecting element (136) for fixing the bottom protection device (100) on the power battery (200).

10. A power battery assembly, comprising: - a power battery (200), the power battery having a battery housing (210) for receiving a battery module; and An underbody protection device (100) arranged below the battery housing (210) and configured according to at least one of the preceding claims.

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