Seal arrangement

Abstract

The invention relates to a seal arrangement (1) having a sleeve-like, in particular elongated oval or ring-shaped supporting body (10) having a through-hole (11), having a first end face (20) in the axial direction y and a second end face (21), having a bearing surface (22) extending outwards in the radial direction x and having an inner surface (23) extending inwards in the radial direction x, wherein a first sealing lip (24) is provided on the first end face (20) and a second sealing lip (26) made of a rubber-elastic material is provided on the bearing surface (22), and wherein the free end of the second sealing lip (26) covers the bearing surface (22) in the mounted state.

Description

[0001] Sealing arrangement

[0002] The invention relates to a sealing arrangement according to the preamble of claim 1.

[0003] With the introduction of electrification in road vehicles, new requirements are emerging regarding the sealing of seals, particularly in the area of ​​battery housings and power electronics enclosures. For example, battery components and power electronics components must be protected against the effects of weather, particularly from water ingress or general moisture. Accordingly, any openings in the battery components and / or the vehicle body must be sealed at least fluid-tight.

[0004] Furthermore, the battery cells heat up during vehicle operation or when charging the battery and thus produce a considerable amount of heat, which must be dissipated from the battery housing.

[0005] Excessively high temperatures primarily damage the electrolytes in the battery cells and, in extreme cases, can lead to a loss of performance and even spontaneous combustion of the battery cells.

[0006] To prevent this, the temperature of the entire battery is monitored. Typically, the battery is first cooled with air and, if necessary, maintained at a target temperature by a specially designed liquid coolant circuit. Specifically, the battery cells are directly flushed with a liquid coolant.

[0007] Furthermore, the battery cells are housed in battery casings that are as heat- and fire-resistant as possible to protect them from ignition and prevent a fire from spreading from the inside to the outside. For example, such a situation can arise due to an undesirable chemical, electrical, and / or mechanical process. This can also lead to very high pressure and elevated temperatures inside a battery casing due to the chemical reaction, degassing of a battery cell, and the resulting increase in temperature.

[0008] As already mentioned, liquid coolant can also keep the battery, in particular the individual battery cells, at a desired temperature, whereby the coolant inside the battery housing directly flows around the individual battery cells.

[0009] However, in the event of an individual battery cell igniting, it is necessary to first vent the resulting gases from the battery cell to prevent it from expanding and potentially exploding. This is usually achieved with some kind of cell-side pressure relief valve, which is provided in the cell housing of the battery cell, particularly in the lid of the battery cell in the case of a prismatic battery cell.

[0010] A prismatic battery cell, like a round cell, is usually a wound cell. Unlike round cells, however, the cell coils are not wound around a mandrel, but rather flat. The resulting flat coil is then packed into a prismatic housing. The electrodes are typically insulated and connected to the outside via the cover. The cell-side pressure relief valve is preferably also located in the cover.

[0011] Since a liquid-cooled and flushed battery cell cannot drain unwanted gases into the cooling circuit, which would inevitably lead to liquid penetration into the battery cell and result in a further chemical exothermic reaction, the cell-side pressure relief valve must be sealed from the coolant. To further increase safety, the seal is not only intended for the event of the pressure relief valve being triggered, but a permanent solution is preferred to insulate the area around the cell-side pressure relief valve from the liquid coolant. This also applies to the electrodes and the electrical contacts of each individual battery cell.

[0012] Furthermore, the sealing arrangement is also designed as a combination seal, which is fitted into an opening in the battery housing as a sealing and EMC shielding element. The sealing arrangement is designed to shield against electrical interference sources in accordance with EMC (electromagnetic compatibility) and to seal against penetrating media. The sealing effect is designed to meet the IP requirements of Class 9K. IP Class 9K ensures protection against water during high-pressure / steam jet cleaning, especially for road vehicles.

[0013] Safety air dampers are already known, and there are several generally accepted solutions for them. According to one solution, for example, a fire damper installed in a wall opening seals off the fire in the event of a fire, thus preventing the fire from spreading. The airflow closure device consists of a shut-off element, its movement and fastening elements, and a housing. The closure element is usually a heat-melting metal element that is closed by gravity, spring force, or electromagnetic force. Effective, directed degassing cannot be ensured in this way.

[0014] DE 10 2012 211 827 A1 discloses a pressure relief valve that can open an opening in a battery housing. The pressure relief valve has a closure element that can be rotated like a flap. When open, the flap-like closure element protrudes relatively far from the battery housing, so that it requires considerable installation space. If other components enter this installation space, they can obstruct the closure element to such an extent that pressure reduction can no longer be sufficiently ensured. DE 43 27 945 A1 also discloses a sealing arrangement, in particular a closure cover for tightly closing an opening. This closure cover consists of a plastic cover part and a sealing part connected to it.Two components are provided: a core component made of a hard material and a shell component made of a softer material that surrounds the core component and can be bonded to the outer edges of the opening. This measure can be used effectively against weather influences, particularly water penetration or general moisture, but does not represent an effective solution for directed degassing.

[0015] The sealing arrangements known from the prior art are therefore not yet optimally designed. On the one hand, effective, directed degassing is not possible, and on the other hand, the sealing arrangement cannot effectively prevent coolant from entering the battery cell.

[0016] The object of the present invention is accordingly to design a sealing arrangement in such a way that, with a simple assembly via the sealing arrangement, a gas-tight or at least liquid-tight closure of the opening to be closed in the battery housing is ensured.

[0017] Furthermore, a fluid-tight connection of the battery housing to the battery cell, in particular around the cell-side pressure relief valve, is to be ensured, whereby, if necessary, a directed degassing via the cell-side pressure relief valve through the battery housing filled with liquid coolant is to be ensured by the sealing arrangement.

[0018] Furthermore, the electromagnetic properties (EMC) of the battery should not deteriorate significantly due to the openings in the battery casing.

[0019] The previously indicated object is now initially achieved by the sealing arrangement with the features of patent claim 1. The sealing arrangement according to the invention has, among other things, the advantage of a minimized insertion force which must be applied in order to insert the sealing arrangement into the opening provided for this purpose in the battery housing and to contact or position the battery cell in a fluid-tight manner with the necessary axial preload or the necessary pressure on the battery cell at the required depth in the opening.

[0020] Furthermore, the sealing arrangement can also advantageously be designed as a combination seal, which can be used as a sealing and EMC shielding element.

[0021] This object is achieved according to the invention in the generic seal with the characterizing features of claim 1.

[0022] First, the sealing arrangement comprises a sleeve-shaped, in particular elongated oval, annular support body with a through-opening. A first end face and a second end face are provided in the axial direction of the support body. A bearing surface extends radially outward, and an inner surface extends radially inward. Preferably, a first sealing lip is provided on the first end face and a second sealing lip made of a rubber-elastic material is provided on the bearing surface, with the free end of the second sealing lip covering the bearing surface in the installed state.

[0023] Alternatively, the first sealing lip and the second sealing lip can be provided on the first end face made of an at least partially rubber-elastic material, wherein the free end of the second sealing lip covers the support surface in the installed state.

[0024] The second sealing lip, in particular the free end of the second sealing lip, is folded back or folded in the opposite direction of movement when the sealing arrangement is inserted into the battery housing opening provided for this purpose and is at least partially pressed onto the support surface provided for this purpose. This initially forms a kind of folded sealing bead in the area around the base of the fold.

[0025] When installed, the sealing bead can grip behind the opening in the battery housing or the battery housing wall and thus represents a type of loss protection.

[0026] The resulting sealing bead in the area around the base of the fold is completely closed to the fluid-carrying area in the battery housing and ensures optimal sealing function.

[0027] This means that no coolant can escape from the battery housing to the outside.

[0028] The compression of the folded sealing bead occurs when the sealing arrangement is pushed into the battery housing opening provided for it and requires a significantly reduced insertion force, even if the radial projection of the second sealing lip relative to the battery housing opening considerably exceeds the usual dimension.

[0029] An additional rubber-elastic, particularly foam rubber-like, support layer can also be provided on the outer side of the support body. The additional support layer thus supplements the support surface and thereby increases the radial expansion of the support body.

[0030] Depending on the material selection, especially the compressibility of the additional support layer, the compressive strength of the sealing arrangement can be varied together with the second sealing lip. This enables a permanent compressive strength of up to 4 bar.

[0031] The second end face of the support body has a closure part with a wall thickness W, in the opposite direction to the first end face. The closure part completely covers the through-opening in the support body, thus preventing moisture or water from penetrating the through-opening. The closure part can also overlap the edge of the support body in such a way that the closure part extends to the support layer on the outside of the support body.

[0032] The closure part is fixed to the second end face. The closure part can be fixed to the second end face by vulcanization, gluing, welding, or any other suitable method. The fixation is fluid-tight, particularly water-, moisture-, or gas-tight.

[0033] The closure part can also have thickenings and / or reinforcements in the form of webs or additional beads, which represent a further increased mechanical resistance against, for example, splash water from outside in the direction of the battery housing opening.

[0034] Furthermore, a removable protective cap can also be provided for the closure part. The protective cap is preferably clamped or clipped onto the sealing arrangement or into the opening in the battery housing.

[0035] Furthermore, one or more predetermined bursting zones are provided in the closure part, which open the passage opening when the internal pressure increases. This occurs when an exothermic reaction occurs in a battery cell and unwanted hot gases accumulate in the cell, causing the cell-side pressure relief valve to open temporarily. The gases accumulate in the passage opening until a predefined bursting pressure is built up, at which point the closure part also opens in the predetermined bursting zone. The gases then escape directly into the environment surrounding the vehicle.

[0036] Furthermore, it can be provided that the closure part melts at an elevated temperature due to the undesirable hot gases, and the through-opening is also released in the intended bursting range. Furthermore, the first sealing lip, the second sealing lip, the support layer, and also the closure part can be made of the same material. Furthermore, it is conceivable that the first sealing lip, the second sealing lip, the additional layer, and also the closure part could merge into one another in one piece.

[0037] The support body can be made of a tough, hard material, particularly a metal sheet such as steel or aluminum. Alternatively, the support body can also be made of a plastic, particularly polyamide. The plastic can also contain fibers. This enables simple and cost-effective production of the support body, for example, by injection molding.

[0038] The support body can also be made of a hybrid material composed of metal and plastic. The support body can have an additional electrically conductive coating on the outside and / or inside, particularly for EMC shielding.

[0039] Advantageously, the entire support body is made of electrically conductive material. This enables simple and cost-effective production of the support body. It is particularly advantageous for the support body to be made of sheet metal. This allows for simple and cost-effective production of the support body. The support body can be easily cut from the sheet metal using a punching process, a jet cutting process, or similar methods. Depending on the seal's intended use, the support body can have a wide variety of contours.

[0040] Furthermore, the first sealing lip and also the second sealing lip, as well as the closure part, can be or are made of an electrically conductive material or provided with an additional electrically conductive coating.

[0041] This allows for improved electrically conductive contact with the cell or battery housing. The sealing arrangement thus also reliably shields the battery housing against the escape of electrical interference. It is also possible to provide the support body with at least one positive locking means. This allows for easy positioning of the seal relative to the components, in particular the battery housing. Furthermore, these positive locking means can also be used for additional contact with the components. The positive locking means can, for example, be elements extending transversely to the support body, preferably as a collar or as transversely projecting tabs.

[0042] Furthermore, it is provided that the second sealing lip, in the installed state, rests axially on a counter surface of a battery cell positioned in the battery housing under axial prestress and thereby contacts the through opening closed by the closure part with the counter surface of the battery cell in a fluid-tight, in particular liquid-tight, manner.

[0043] Preferably, the mating surface of the battery cell completely encloses the battery cell-side pressure relief valve. This ensures that, when installed, the static sealing connection between the second sealing lip and the mating surface of the battery cell, under axial preload, prevents coolant from entering the battery cell via the battery cell-side pressure relief valve.

[0044] In a further development, the counter surface of the battery cell can also comprise an entire surface, in particular the entire cover of a prismatic battery cell.

[0045] The rubber-elastic material, which is made of elastomeric material, preferably silicone or ACM, can be used against penetrating media up to IP class 9K.

[0046] The IP protection class 9K offers protection against very intense water jets, such as those used in vehicles with high-pressure steam jets. In particular, the seal ensures that the correspondingly sealed housing in a vehicle is perfectly sealed during water crossings.

[0047] This is particularly important when the seal or sealing arrangement is used to seal a battery housing containing lithium batteries. Furthermore, the sealing arrangement according to the invention is characterized by high resistance to climate change and salt spray. The sealing arrangement can also prevent harmful contact corrosion.

[0048] The subject matter of the application arises not only from the subject matter of the individual patent claims, but also from all information and features disclosed in the drawings and the description. Even if they are not the subject matter of the claims, they are claimed as essential to the invention insofar as they are novel, individually or in combination, over the prior art.

[0049] Further features of the invention emerge from the further claims, the description and the drawings.

[0050] The invention will be explained in more detail with reference to some embodiments shown in the drawings. They show schematically

[0051] Fig. 1 shows a sectional view of a sealing arrangement according to the invention,

[0052] Fig. 2 shows a sectional view of a sealing arrangement according to the invention in the installed position,

[0053] The sealing arrangement described below is also designed as a combination seal, which can be used as a sealing and EMC shielding element between components. The seal is designed to shield against electrical interference sources in accordance with EMC (electromagnetic compatibility) and to seal against penetrating media.

[0054] The sealing effect can be designed to meet the IP requirements of Class 9K. IP Class 9K ensures protection against water during high-pressure / steam jet cleaning, especially for road vehicles.

[0055] The sealing arrangement has a supporting body which serves as a carrier for at least one elastomeric, in particular rubber-elastic sealing body.

[0056] The sealing body here is understood to mean in particular the first sealing lip and a second sealing lip.

[0057] The support body can also have a radially outward and / or inwardly extending collar, which acts as a stop in the installed position for precise positioning and determining the installation depth. The collar is preferably aligned parallel to one end face, but can also be inclined relative to one of the two ends.

[0058] Furthermore, the sealing arrangement 1 can be designed as an electrically conductive EMC shielding element. In this way, the sealing arrangement 1 advantageously combines both functions in a single component.

[0059] Fig. 1 shows an example of such a sealing arrangement 1, which has an elongated oval shape. The illustrated design of the sealing arrangement 1 is to be understood only as an example. Depending on the application, the sealing arrangement 1 can have a wide variety of contours, for example, circular or annular.

[0060] It can be clearly seen that the sealing arrangement 1 comprises a sleeve-shaped support body 10 which has the same outline shape as the entire sealing arrangement 1 or seal.

[0061] The support body 10 is elongated oval here, but can also be annular. The support body 10 has a through-opening 11 with a first end face 20 extending in the axial direction y and an opposite second end face 21, with a support surface 22 extending outward in the radial direction x, and with an inner surface 23 extending inward in the radial direction x. A first sealing lip 24 made of a rubber-elastic material is provided on the first end face 20.

[0062] A second sealing lip 26 made of a rubber-elastic material is provided on the support surface 22, wherein the free end of the second sealing lip 26 covers the support surface 22 in the installed state (see also Fig. 2).

[0063] Here in Fig. 1, it is clearly visible that the free end of the second sealing lip 26 extends radially over the entire extent of the opening in the battery housing 5 and rests against the edge of the opening on the battery housing 5. The sealing lips 24, 26 can also have a structured surface, as shown here, for example, on the second sealing lip 26 as a wave-shaped bulge.

[0064] The support body 10 further has on the support surface 22 a support layer 25 extending outwards in the radial direction x and having a radial height h.

[0065] It can also be seen that the support body 10 has a closure part 30 with a predetermined wall thickness W on the second end face 21, wherein the closure part 30 completely covers the through-opening 11 and thus closes it. Preferably, the through-opening 11 is thereby sealed in a gas-tight manner.

[0066] In one embodiment, the sealing arrangement 1 is constructed from a single material, with the first sealing lip 24, the second sealing lip 26, the support layer 25, and the closure part 30 being constructed from a single material. The support body 10 is exempt from this material uniformity and can be formed from a metal sheet.

[0067] In a further preferred embodiment, the support body 10 is made of a plastic, in particular polyamide. The plastic also includes fibers. The support body 10 can also be made of an electrically conductive material. Advantageously, the support body 10 is then made of a metallic material, which allows for cost-effective production. Steel or aluminum can advantageously be used as the metallic material.

[0068] It is also possible to manufacture the support body 10 from an electrically conductive plastic. The plastic can advantageously be a thermoset, which has sufficient strength.

[0069] In this context, the sealing bodies can be provided with an electrically conductive coating. Then the support body 10 itself does not need to be made of an electrically conductive material. This can lead to lower manufacturing costs for the sealing arrangement.

[0070] From Fig. 1 it can also be seen that the closure part 30 has a bursting area 28 with a reduced wall thickness W, which opens the closure part 30 when a defined pressure is applied from within the through-opening 11 and thereby enables a fluid flow to escape through the closure part 30 into the environment.

[0071] Fig. 2 shows the sealing arrangement 1 from Fig. 1 in the installed state. It is clearly visible that the free end of the second sealing lip 26 now covers the support surface 22. The degree of overlap can be adapted to the respective application by, for example, varying the radial extension or the thickness of the second sealing lip 26.

[0072] It can be clearly seen that the second sealing lip 26, in the installed state, rests axially on a mating surface 41 of a battery cell 40 in the battery housing 5 and thereby makes fluid-technical and liquid-tight contact between the through-opening 11 and the mating surface 41 of the battery cell 40. The coolant is accordingly permanently kept away from the cell-side pressure relief valve 42. Any gas flow that may occur and escapes from the cell-side pressure relief valve 42 can thus be diverted into the environment through the through-opening 11 without coming into contact with the coolant. The battery cell 40 is not shown in full here; what is intended to be shown here is the cover of the battery cell with the cell-side pressure relief valve 42.

[0073] A material for the sealing bodies, in particular the sealing lips 24, 26, with the material properties listed in the table below has proven to be very advantageous.

[0074] Alternatively, a polyacrylate rubber (ACM) or an ethylene acrylate rubber (AEM) can be used.

Claims

Patent claims 1. Sealing arrangement (1) comprising a sleeve-shaped, in particular elongated oval or ring-shaped support body (10) with a through-opening (11), with a first end face 20 in the axial direction y and a second end face (21), with a support surface (22) extending outwards in the radial direction x and with an inner surface (23) extending inwards in the radial direction x, wherein a first sealing lip (24) is provided on the first end face (20) and a second sealing lip (26) made of a rubber-elastic material is provided on the support surface (22), wherein the free end of the second sealing lip (26) covers the support surface (22) in the installed state.

2. Sealing arrangement according to claim 1, characterized in that the second sealing lip (26) covers the support surface (22) in the installed state to form a parting plane.

3. Sealing arrangement according to claim 1 or 2, characterized in that the support body (10) has on the support surface (22) outwards in the radial direction x an outwardly extending support layer (25) with a radial height h.

4. Sealing arrangement according to claim 1, 2 or 3, characterized in that the support body (10) has on the second end face (21) a closure part (30) with a wall thickness W, wherein the closure part (30) completely covers the through opening (11).

5. Sealing arrangement according to one of the preceding claims, characterized in that the first sealing lip (24), the second sealing lip (26) and the support layer (25) are made of the same material.

6. Sealing arrangement according to one of the preceding claims, characterized in that the supporting body (10) is formed from a metal sheet and / or from a plastic, in particular polyamide or polyacrylate rubber (ACM) or ethylene acrylate rubber (AEM).

7. Sealing arrangement according to one of the preceding claims, characterized in that the closure part (30) has a bursting area (28) with a reduced wall thickness W.

8. Sealing arrangement according to one of the preceding claims, characterized in that the second sealing lip (24) in the installed state axially rests on or rests on a counter surface of a battery cell in the battery housing (5) under axial prestress and thereby contacts the through opening (11) with the counter surface (41) of the battery cell (40) in a fluid-tight manner, in particular connecting it in a liquid-tight manner, and the counter surface (41) hereby comprises the cell-side pressure relief valve (40).

9. Sealing arrangement according to one of the preceding claims, characterized in that the sealing arrangement is also designed as a combination seal which can be used as a sealing and as an EMC shielding element.

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