Battery housing with a structural sandwich base for a motor vehicle

Abstract

The invention relates to an accumulator housing (100) comprising a structural sandwich floor for a motor vehicle (300), comprising the following features: a lid (110), a base plate (130), a frame (120), wherein the frame is arranged between the lid and the base plate, thereby defining a receiving space (140) for at least one accumulator (145), wherein the base plate comprises at least three layers, wherein the base plate comprises at least a first layer (131), a second layer (134) and a third layer (136), wherein the first layer comprises a smooth surface for receiving the at least one accumulator, wherein the second layer has a honeycomb structure (135), and wherein the third layer is configured to seal the receiving space against an exterior area of ​​the accumulator housing.

Description

The present invention relates to an accumulator housing with a structural sandwich base for a motor vehicle and an associated degassing device. Electric and hybrid vehicles are becoming increasingly important, leading to a growing demand for safe and efficient energy storage systems. A key component of these systems are batteries, which are housed in specialized battery frames. These frames must not only provide mechanical protection for the battery cells but also ensure safety in the event of cell malfunctions, particularly with regard to the venting of gases that can occur during thermal runaway. Existing solutions often have drawbacks, such as insufficient strength, complex designs, or inefficient degassing mechanisms. Sealing the battery frame while simultaneously allowing controlled degassing presents a particular technical challenge. Uncontrolled gas leakage can damage vehicle components and, in the worst case, cause injury. US Patent 2023 / 0238610A1 relates to a battery housing comprising an electrical chamber for accommodating battery cells, a thermal management component, and a collection chamber for capturing emissions upon activation of a pressure relief mechanism. The collection chamber incorporates a support element, which may have a honeycomb cross-sectional structure and is horizontally oriented. The collection chamber can be designed as a sealed chamber, with pressure relief occurring via predefined areas within the thermal management component. CN 1 20 565 954 A relates to a battery box with a battery frame and a honeycomb aluminum plate comprising a top layer plate, a honeycomb layer, and a bottom layer plate. Openings are provided in the sidewalls of the honeycomb cavities; these openings communicate with each other and form a directed exhaust duct connected to a main explosion protection valve. The degassing path is thus pre-formed and is not released by thermal melting. CN 2 18 351 596 U relates to a battery pack with a box housing and a box lid, the frame being designed as a hollow structure with frame exhaust vents and explosion protection valves. The box base comprises a base plate, an energy absorption structure in the form of a honeycomb plate or foam aluminum plate, and a liquid cooling plate. Degassing occurs via predefined module exhaust vents and the hollow structure of the frame. CN 2 20 652 261 U relates to a battery device with a battery carrier comprising a first layer plate, a second layer plate, and separating ribs, wherein the separating ribs divide the space between the layer plates into independent exhaust cavities with a honeycomb structure. Degassing occurs through predefined through-holes in the first layer plate. The layer plates are made of high-melting-point metal and are expressly designed so that they do not melt in the event of thermal runaway. The present invention aims to overcome these disadvantages and provide an improved battery frame with a novel degassing device that combines high structural integrity with an effective and safe degassing function. This is achieved by a structural sandwich base according to the invention. According to the invention, an accumulator housing with a structural sandwich base for a motor vehicle according to claim 1, and a motor vehicle with an accumulator housing with a structural sandwich base according to claim 8, are provided. Advantageous embodiments can be found in the dependent claims and the description. The invention relates to an accumulator housing comprising a structural sandwich floor for a motor vehicle, comprising the following features. An accumulator housing with a lid, a base plate, and a frame, wherein the frame is arranged between the lid and the base plate, thereby defining a receiving space for at least one accumulator, wherein the base plate comprises at least three layers, wherein the base plate comprises at least a first layer, a second layer, and a third layer, wherein the first layer comprises a smooth surface for receiving the at least one accumulator, wherein the second layer has a honeycomb structure, and wherein the third layer is configured to seal the receiving space against an exterior area of ​​the accumulator housing. The first, second, and third layers thus form a sandwich floor. In a further advantageous design, the sandwich floor is self-supporting. In an advantageous further development, at least one accumulator comprises several cells. According to the invention, the honeycomb structure is gas-permeable in the Z-direction. The individual axes and planes, as well as the rotational and pivoting movements, refer to the vehicle coordinate system commonly used in vehicle construction. The origin of the coordinate system lies at the vehicle's center of gravity. The positive X-axis points in the direction of travel. The positive Z-axis points upwards towards the vehicle's roof. The positive Y-axis is perpendicular to the driver's door of a left-hand drive vehicle and points to the left in the direction of travel. Not only directed movements but also moments can occur on the vehicle. These moments act around the coordinate axes. Movement around the X-axis is called roll, around the Y-axis pitch, and around the Z-axis yawing. Yawing can also be described as "rolling." In a further training course, the accumulator includes a cell valve for pressure relief. In a further training, the first layer includes at least one breakthrough, the position of which corresponds to the position of the respective cell valve of the accumulator. In an advantageous further development, the first layer or the third layer is made of or comprises metal, in particular aluminum and / or a fiber-reinforced plastic. In an advantageous further development, the frame is designed as an extruded profile. In an advantageous further development, at least one accumulator is bonded to the second layer. This ensures that the accumulators retain their position even in an accident situation. According to the invention, the third layer is designed to release a degassing path when hot gases escaping from the accumulator pass through it, thereby enabling the escaping hot gases to be discharged. According to the invention, the third layer is designed such that it is melted through by the escaping gases or flames from the at least one accumulator. In other words, this melting can also be described as thermal burn-off. In a further advantageous embodiment, the cell valve can be designed to vent the gases or flames generated when the fluid passes through at least one accumulator. This allows for a controlled pressure reduction. In a further advantageous embodiment, the cell valve is designed to release any existing overpressure from within the accumulator housing's receiving chamber to the outside. The cell valve can also be designed as a safety feature to prevent the accumulator housing from bursting due to overpressure. By releasing the overpressure, a controlled pressure reduction can be achieved. In a further advantageous embodiment, the cell valve can be designed as a mechanical and / or electronic pressure relief valve. The cell valve can be designed to open and close reversibly or include a predetermined breaking point. The term "runaway" in a battery generally refers to a condition in which an uncontrolled chemical reaction occurs. This can lead to overheating, gas formation, or even explosion. Furthermore, runaway can be triggered by various causes such as overcharging, deep discharging, mechanical damage, or internal short circuits. Runaway occurs in several phases: First, overcharging or malfunctions can cause the battery to overheat. The extreme heat can cause gases to form inside the battery, leading to expansion or even rupture. If the temperature continues to rise, the chemical reactions inside the battery can become uncontrollable, a process known as thermal runaway.This is a chain reaction in which the generated heat triggers further reactions that generate even more heat. In an advantageous embodiment, the frame and / or the cover can include cooling channels for cooling the battery housing, in particular the at least one battery. The cooling channels can form a cooling circuit through which a coolant is pumped. The coolant serves to cool the at least one battery. In an advantageous further development, the cooling device and / or a motor vehicle comprises an underride guard which is at least partially arranged in the outlet area of ​​the degassing path and / or opposite the cell valve, wherein the underride guard is designed as a sandwich structure and / or includes drainage channels. In an advantageous further development, the underride guard is designed such that gases and / or flames escaping from the cell valve are introduced into the underride guard and can be distributed or selectively discharged via drainage channels. Extending the path of the introduced gases and / or flames allows for further cooling. When hot gases or flames are expelled through the cell valve, the underride guard acts as a baffle plate, preventing the direct escape of flames or hot gases. This is intended to protect anyone approaching the vehicle, whether as a helper or as a vehicle occupant. In an advantageous further training, the underride protection may be made of metal and / or glass fiber reinforced plastic, or may include such a material or such a material mix. In a further advantageous embodiment, the glass fiber reinforced plastic is designed as, or comprises, a glass fiber reinforced thermoplastic. The glass fiber reinforced thermoplastic can be high-temperature resistant and / or insulating. The glass fibers in the glass fiber reinforced thermoplastic can be configured as long fiber structures. Glass fiber reinforced thermoplastics that integrate long fibers can offer several advantages over short-fiber reinforced thermoplastics. By embedding long fibers within the polymer matrix material, significantly improved mechanical properties can be achieved, including higher tensile strength, impact strength, and increased fatigue resistance. This is due to the effective load distribution that long-fiber reinforced structures enable within the material. An additional advantage is the increased fracture toughness, which translates into improved energy absorption of the material before fracture occurs. This makes components reinforced with long fibers significantly more resistant to brittle failure behavior and high temperatures. Long-fiber-reinforced thermoplastics offer clear advantages in terms of weight savings while maintaining stiffness and strength. They are not only lighter but can also exhibit superior thermal properties, making them more reliable, especially under extreme temperatures. Furthermore, long-fiber-reinforced thermoplastics can offer improved chemical resistance. Glass fiber reinforced thermoplastics are materials that combine a base plastic with glass fibers to improve the mechanical and thermal properties of the original plastic. This reinforcement can significantly increase its strength and stiffness, making the material more resistant to mechanical stress. Additionally, it can offer improved dimensional stability and reduced elongation under thermal stress. In a preferred embodiment, long glass fibers can be used to fabricate the upper and / or lower cell support structure entirely from such a glass fiber reinforced thermoplastic. The exact properties can be adjusted by the type of thermoplastic used, such as PA, PP, PBT, and / or the type, length and orientation of the glass fibers and / or the ratio of the glass fibers to the thermoplastic, as well as the processing method. In an advantageous further development, the underride guard can be designed as a sandwich structure and include the drainage channels within the sandwich structure. Alternatively or additionally, the underride guard can include drainage channels on a side facing the cell valve. In a further advantageous design, the underride guard can be part of the cooling system. Alternatively or additionally, the underride guard can be a separate component connected to the vehicle's underbody. In a further development, the underride guard is arranged below the third layer, with at least two sealing elements positioned between the third layer and the underride guard, forming a receiving space. This receiving space can be formed between the underride guard and the third layer. The sealing element can be made of rubber or comprise a rubber component. Silicone or rubber can be used as the material. In an advantageous further development, the receiving space is shaped like a trough, wherein the receiving space has a first end and a second end opposite the first end, with a sealing element arranged at each end. In an advantageous further development, the underride guard includes a sealing chamber. The sealing chamber can be formed by a siphon-like design of the underride guard. In a further advantageous embodiment, the sealing chamber is designed such that the underride guard rests against the third layer on one side and against the frame and / or the third layer on a second side. This protects the sealing element located in the sealing chamber from particles escaping from the receiving chamber or from contamination from the road surface. In a further development, the first layer and / or the third layer and the frame comprise a flange area, wherein the flange area of ​​the first layer and / or the third layer is connected to the flange area of ​​the frame. The flange area of ​​the layers is an area at least partially circumferential around the respective layer, in which the respective layer can be connected to another component of the accumulator housing. In an advantageous further development, the flange area of ​​the frame points towards the receiving space. Alternatively or additionally, the flange area of ​​the frame is formed all the way around the receiving space. In an advantageous embodiment, the first layer, particularly its flange area, rests on the flange area of ​​the frame. This resting position refers to the top view of the accumulator housing. The third layer, particularly its flange area, is positioned against the flange area of ​​the frame from below. In a further advantageous embodiment, the flange area of ​​the frame is positioned between the flange area of ​​the first layer and the flange area of ​​the third layer. This allows the frame and the individual layers to be stiffened together. In a further training course, the connection between the first layer and the frame and the third layer and the frame is designed as a welded connection and / or adhesive connection. According to the invention, the first layer and / or the second layer and / or the third layer are bonded together. In a further training, the first layer consists of or comprises a steel material and / or an aluminum material, and the second layer is formed from or comprises a plastic matrix or a metal matrix. The invention also relates to a motor vehicle comprising an accumulator housing with a structural sandwich base, according to at least one of the aforementioned further developments. The invention is described below by way of example only, with reference to the drawings. The drawings show: Fig. 1 schematically shows an accumulator housing in normal operation according to one embodiment of the invention; Fig. 2 schematically shows an accumulator housing in the event of a fault according to one embodiment of the invention; Fig. 3 shows a schematic assembly of the accumulator housing according to one embodiment of the invention; and Fig. 4 shows a motor vehicle with an accumulator housing. Fig. 1 shows an accumulator housing 100 with a structural sandwich base for a motor vehicle 300 in normal operation, comprising an accumulator housing 100 with a cover 110, a base plate 130, a frame 120, wherein the frame 120 is arranged between the cover 110 and the base plate 130, thereby defining a receiving space 140 for at least one accumulator 145, wherein the base plate 130 comprises at least three layers, wherein the base plate 130 comprises at least a first layer 131, a second layer 134 and a third layer 136, wherein the first layer 131 comprises a smooth surface for receiving the at least one accumulator 145, wherein the second layer 134 has a honeycomb structure 135, and wherein the third layer 136 is configured to seal the receiving space 140 against an exterior area of ​​the accumulator housing 100. In a further training course, the honeycomb structure 135 is permeable in the Z direction. In a further training, the accumulator 145 includes a cell valve 146 for pressure relief in the event of thermal runaway. In a further training, the first layer 131 includes at least one breakthrough 132, the position of which of the at least one breakthrough 132 corresponds to the position of the respective cell valve 146 of the accumulator 145. In a further training course, the third layer 136 is trained to release a degassing path 137 in the event of a pass through the accumulator 145 by escaping hot gases from the accumulator 145, thereby enabling the escape of the escaping hot gases. In a further development, the first layer 131 and / or the third layer 136 and the frame 120 comprise a flange area 121,133,138, wherein the flange area 121,133,138 of the first layer 131 and / or the third layer 136 is connected to the flange area 121 of the frame 120. In a further development, an underride guard 150 is arranged below the third layer 136, wherein at least two sealing elements 151 are arranged between the third layer 136 and the underride guard 150, and a receiving space 140 is formed. The underride guard 150 encloses a sealing chamber 153. The sealing chamber 153 can be formed by a siphon-like design of the underride guard 150. In an advantageous embodiment, the sealing chamber 153 is designed such that the underride guard 150 abuts the third layer 136 on one side and the frame 120 and / or the third layer 136 on a second side. This protects a sealing element 151 located in the sealing chamber 153 from particles escaping from the receiving chamber 140 or the at least one accumulator 145, or from contamination from the road surface. Fig. 2 shows an accumulator housing 100 with a structural sandwich base for a motor vehicle 300 in the event of a failure, comprising an accumulator housing 100 with a cover 110, a base plate 130, a frame 120, wherein the frame 120 is arranged between the cover 110 and the base plate 130, thereby defining a receiving space 140 for at least one accumulator 145, wherein the base plate 130 comprises at least three layers, wherein the base plate 130 comprises at least a first layer 131, a second layer 134 and a third layer 136, wherein the first layer 131 comprises a smooth surface for receiving the at least one accumulator 145, wherein the second layer 134 has a honeycomb structure 135, and wherein the third layer 136 is configured to seal the receiving space 140 against an exterior area of ​​the accumulator housing 100. In a further development, the honeycomb structure 135 is permeable in the Z-direction. In a further development, the accumulator 145 includes a cell valve 146 for pressure relief. In a further training, the first layer 131 includes at least one breakthrough 132, the position of which of the at least one breakthrough 132 corresponds to the position of the respective cell valve 146 of the accumulator 145. In a further training course, the third layer 136 is trained to release a degassing path 137 in the event of a pass through the accumulator 145 by escaping hot gases from the accumulator 145, thereby enabling the escape of the escaping hot gases. In the figure shown, at least one accumulator 145 has undergone thermal runaway and thermally burned off a degassing path 137 through the third layer 136. The escaping hot gases, flames, and particles are captured in the underride guard 150. In a further development, the first layer 131 and / or the third layer 136 and the frame 120 comprise a flange area 121,133,138, wherein the flange area 121,133,138 of the first layer 131 and / or the third layer 136 is connected to the flange area 121 of the frame 120. In a further development, an underride guard 150 is arranged below the third layer 136, wherein at least two sealing elements 151 are arranged between the third layer 136 and the underride guard 150, and a receiving space 140 is formed. The underride guard 150 encloses a sealing chamber 153. The sealing chamber 153 can be formed by a siphon-like design of the underride guard 150. In an advantageous embodiment, the sealing chamber 153 is designed such that the underride guard 150 abuts the third layer 136 on one side and the frame 120 and / or the third layer 136 on a second side. This protects a sealing element 151 located in the sealing chamber 153 from particles escaping from the receiving chamber 140 or the at least one accumulator 145, or from contamination from the road surface. Fig. 3 shows a schematic structure of the accumulator housing 100 with a sandwich base comprising three layers 131, 134, 136. The accumulator housing comprises a cover 110 and a frame 120, the frame being designed to accommodate accumulators 145. The first layer 131, which is perforated, is located below or within the frame. The second layer 134 is arranged below the first layer 131. The second layer 134 is designed as a honeycomb structure, the honeycomb structure being open in the Z-direction. The honeycomb structure allows gas escaping from the accumulator 145 to be directed towards the third layer 136. Fig. 4 shows a motor vehicle 300 with an accumulator housing 100. The invention is not limited to the described embodiments. Within the scope of the invention, all described and / or drawn features can be combined with one another as desired, unless otherwise stated. Reference sign 100 Accumulator housing 110 Cover 120 Frame 121 Flange area 130 Base plate 131 First layer 132 Opening 133 Flange area 134 Second layer 135 Honeycomb structure 136 Third layer 137 Degassing path 138 Flange area 139 Connection point 140 Receiving space 145 Accumulator 146 Cell valve 150 Underride guard 151 Sealing element 152 Flange area 153 Sealing space 300 Motor vehicle

Claims

Accumulator housing (100) with a structural sandwich base for a motor vehicle (300), comprising a lid (110), a base plate (130), and a frame (120), wherein the frame (120) is arranged between the lid (110) and the base plate (130), thereby defining a receiving space (140) for at least one accumulator (145), wherein the base plate (130) comprises at least three layers, the base plate (130) comprising at least a first layer (131), a second layer (134), and a third layer (136), wherein the first layer (131) comprises a smooth surface for receiving the at least one accumulator (145), wherein the second layer (134) has a honeycomb structure (135), and wherein the third layer (136) is configured to seal the receiving space (140) against an exterior area of ​​the accumulator housing (100), wherein the honeycomb structure (135) is designed to be gas-permeable in the Z direction,wherein the third layer (136) is configured to release a degassing path (137) by melting through the third layer (136) when hot gases and / or flames escape from the at least one accumulator (145) pass through it, thereby enabling the escape of the escaping hot gases, wherein the first layer (131) and / or the second layer (134) and / or the third layer (136) are bonded together. Accumulator housing (100) according to claim 1, characterized in that the at least one accumulator (145) comprises a cell valve (146) for pressure relief. Accumulator housing (100) according to claim 2, characterized in that the first layer (131) defines at least one opening (132), wherein the position of the at least one opening (132) corresponds to the position of the respective cell valve (146) of the at least one accumulator (145). Accumulator housing (100) according to one of the preceding claims, characterized in that the first layer (131) and / or the third layer (136) and the frame (120) comprise a flange area (121, 133, 138), wherein the flange area (121, 133, 138) of the first layer (131) and / or the third layer (136) is connected to the flange area (121) of the frame (120). Accumulator housing (100) according to claim 4, characterized in that the connection between the first layer (131) and the frame (120) and the third layer (136) and the frame (120) is formed as a welded connection and / or adhesive connection. Accumulator housing (100) according to one of the preceding claims, characterized in that the first layer (131) consists of or comprises a steel material and / or an aluminum material and that the second layer (134) is formed of or comprises a plastic matrix or a metal matrix. Accumulator housing (100) according to one of the preceding claims, characterized in that an underride guard (150) is arranged below the third layer (136), wherein at least two sealing elements (151) are arranged between the third layer (136) and the underride guard (150), wherein a receiving space (140) is formed. motor vehicle (300) comprising an accumulator housing (100) with a structural sandwich base, according to one of the preceding claims.

Images