Pressure equalization element for a battery system, vehicle battery system, and vehicle with a battery system and pressure equalization element

Abstract

Pressure equalization element (12) for a battery system, comprising a housing base element (22) which has a flow section (28) leading from an environment (U) to a sealing chamber (16) with an inlet side (E) and an outlet side (A), comprising a cover (30) arranged on the environment side of the housing base element (22) and covering the inlet side (E), which is removable so that it can be detached if necessary, and comprising a valve element (40) arranged in the housing base element (22) which is designed such that it opens the flow section (28) when there is negative pressure in the sealing chamber (16) and closes it when there is positive pressure in the sealing chamber (16), wherein an outlet opening from the housing base element (22) downstream of the valve element (40) is closed by means of a diaphragm (46), characterized in that the valve element (40), when the cover (30) is removed, can be placed in a test situation by means of a test device (66). It can be brought into an open position.

Description

[0001] The invention relates to a pressure equalization element for a battery system, in particular a pressure equalization element for a vehicle battery system. Furthermore, the invention relates to a vehicle battery system for a vehicle and to a vehicle with a battery system and a pressure equalization element. In particular, the invention relates to vehicles in the form of motor vehicles.

[0002] From DE 10 2011 015 925 A1, a battery system is known with a battery housing having an opening in which or on which an air exchange device is provided. The air exchange device allows air exchange between the interior of the battery housing and the environment and prevents or at least minimizes the ingress of liquid into the interior of the battery housing. The air exchange device comprises a valve and a diaphragm, the diaphragm being arranged on the inlet side. The device does not describe how the diaphragm can be removed in a way that would allow the valve to be actuated for testing purposes, nor does it describe any other way of testing the valve's functionality.

[0003] German patent application DE 10 2021 126 075 A1 describes a battery housing with a pressure equalization function, a pressure equalization element, a traction battery, and a motor vehicle. The pressure equalization element comprises two diaphragms and associated valves, both covered by a lid referred to as a protective cover. However, even after removing the cover, the valves are inaccessible because the diaphragms continue to obstruct access. No method for testing the functionality of the valve is described.

[0004] From DE 10 2017 221 622 A1, a storage housing for a high-voltage storage device of a motor vehicle, a high-voltage storage device, and a motor vehicle incorporating these elements are known. The storage housing has a pressure equalization element for pressure equalization between the interior of the housing and the surrounding environment. Furthermore, the storage housing has a safety valve that opens in the event of a sudden overpressure. The pressure equalization element and the safety valve are designed as separate elements and are decoupled from each other. The pressure equalization element does not have a blocking direction by which the ingress of dirt or other substances can be prevented.

[0005] From DE 10 2013 218 911 A1, a valve with a pressure equalization function, a battery with such a valve, and a vehicle with such a battery are known. The valve, when used with a connected leak tester, is intended to check the tightness of the battery housing. Separate valve elements are provided to equalize pressure in the battery housing in the event of overpressure or underpressure. For this reason, the device has a relatively large number of individual parts, requires a relatively large amount of installation space, and is costly to manufacture and assemble. Furthermore, no pressure equalization element with a blocking direction, by means of which the ingress of dirt or other substances could be prevented, is disclosed.

[0006] From DE 10 2019 215 433 A1, a pressure equalization element for leak testing of a housing is known. The pressure equalization element is designed to compensate for pressure differences between the interior of a housing and the environment surrounding the housing.

[0007] From US 2022 / 0 090 692 A1, a pressure equalization element is known which can be regarded as having the features of the preamble of claim 1.

[0008] The invention is based on the objective of providing a pressure equalization element for a battery system, a vehicle battery system, and a vehicle with a battery system and a pressure equalization element, which are structurally simple and, in their intended operation, have an opening direction and a closing direction, wherein the entry of moisture and particles, in particular dirt, is to be prevented in the closing direction. It should be as easy as possible to verify whether the valve element is functioning reliably.

[0009] The problem is solved according to the invention by the features of the independent claims. Further practical embodiments and advantages of the invention are described in connection with the dependent claims.

[0010] A pressure equalization element according to the invention for a battery system comprises a housing base element which has a flow section leading from the environment to a sealing chamber, with an inlet side and an outlet side. The pressure equalization element further comprises a cover arranged on the ambient side of the housing base element, covering the inlet side, which is removable so that it can be taken off if necessary, and a valve element arranged in the housing base element. The valve element is designed such that it opens the flow section when there is negative pressure in the sealing chamber and closes it when there is positive pressure in the sealing chamber, wherein an outlet opening from the housing base element downstream of the valve element is closed by means of a diaphragm, preferably by means of a semipermeable diaphragm.With the cover removed, the valve element can be brought into an open position for testing purposes using a test device. The pressure equalization element according to the invention has a simple design and, in its intended operation, features an opening direction and a closing direction. In the closing direction, the ingress of moisture and particles, particularly dirt, can be prevented. Furthermore, the test device makes it easy to verify whether the valve element is functioning reliably.

[0011] In a practical embodiment of the pressure equalization element according to the invention, the valve element is made of an elastic material, and opening under negative pressure is achieved by elastic deformation of the valve element. In this case, no structurally complex movement mechanisms or bearings are required, in particular no linear guides or hinges. Assembly with a valve element made of an elastic material can also be carried out particularly easily by pressing or inserting it.

[0012] In another practical embodiment of the pressure equalization element according to the invention, the valve element is snapped into the housing base element. This further simplifies assembly.

[0013] In this context, particular attention is drawn to the structurally simple possibility of incorporating at least one elastically deformable detent element on the valve element itself. Such a detent element can, in particular, consist of several detent lugs, especially those evenly distributed around the circumference. Furthermore, a circumferential detent lug can also be provided as a collar-like protruding detent element on the valve element.

[0014] In another practical embodiment of a pressure equalization element according to the invention, a plate-shaped sealing section and / or a collar-shaped locking element are formed on the valve element, and / or the valve element is formed in one piece. Preferably, several or all of the features described above are implemented on a pressure equalization element according to the invention, so that a multitude of functions are realized on a single valve element, enabling cost-effective manufacturing, simple assembly, and reliable operation of a pressure equalization element according to the invention.

[0015] If the housing base element of a pressure equalization element according to the invention is formed in at least two parts and consists of a housing base body and a mounting sleeve functionally connected to it, the housing base body and the mounting sleeve can be designed such that two-sided mounting on another element is possible. In particular, a pressure equalization element according to the invention can then be mounted by inserting the housing base body into an opening from one side of the opening and arranging the mounting sleeve around the housing base body from the other side of the opening. If, in addition, the mounting sleeve and the housing base body are designed to be interlocked, these two elements can be mounted to each other and directly onto an opening of another element by simply pushing them together.This results in particularly easy installation on an opening of a corresponding element.

[0016] If the housing base element is formed from a housing body and a mounting sleeve, particularly if these elements can be assembled by simply pushing them together, it is especially preferred if a sealing element is arranged between the housing body and the mounting sleeve. Preferably, in this case, the sealing element is arranged in the area of ​​a groove-shaped sealing element section, which can be formed on the housing body and / or on the mounting sleeve. Accordingly, it is possible to form the sealing element section either only on the housing body, only on the mounting sleeve, or on a combination of the housing body and the mounting sleeve. The purpose of the sealing element section is to restrict the relative position of the sealing element with respect to the housing body and the mounting sleeve to a specific range.This can be achieved in particular by forming a corresponding recess for the arrangement of the sealing element.

[0017] In another practical embodiment of a pressure equalization element according to the invention, the cover has a U-shaped cross-section and is arranged to enclose the surrounding side of the housing base element. In this case, particularly reliable protection of the surrounding side against the direct ingress of liquid, especially rainwater and / or splash water, which could penetrate towards the surrounding side of the flow section during the operation of a vehicle, especially a motor vehicle, is achieved.

[0018] The invention also relates to a vehicle battery system with a sealed battery compartment which is closed towards the environment by means of a pressure equalization element as described above and additionally has a pressure relief valve at another position which, in the event of overpressure in the battery compartment, enables pressure equalization to the environment or to another pressure chamber. Reference is hereby made again to the advantages already described above in connection with the pressure equalization element.

[0019] The invention further relates to a vehicle, in particular a motor vehicle, with a pressure equalization element as described above and / or with a vehicle battery system designed as described above. The advantages described above also apply in connection with such a vehicle, particularly in connection with the corresponding embodiments of the pressure equalization element.

[0020] Further practical embodiments of the invention are described below in connection with the drawings. They show: Fig. 1 a vehicle battery system with a sealed battery compartment which is closed towards one environment by means of a pressure equalization element and has a pressure relief valve at another position which allows pressure equalization to the environment in case of overpressure in the battery compartment, Fig. 2 an embodiment of a pressure equalization element according to the invention in a first state with an open flow section, Fig. 3 an enlarged representation of the in Fig. 2 areas marked with III, Fig. 4 the pressure equalization element from Fig. 2 in a second, closed state, Fig. 5 den in Fig. 3. Area marked with V in an enlarged view, Fig. 6 the pressure equalization element from the Fig. 2 and Fig. 4 in a further state with the valve element opened by means of a test device, Fig. 7 den in Fig. 6 area marked VII in an enlarged view and Fig. 8 den in Fig. 6. Area marked VIII in an enlarged view.

[0021] In Fig. Figure 1 shows a section of a vehicle battery system 10. The vehicle battery system 10 includes a pressure equalization element 12, which is subsequently shown in conjunction with the Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7 to Fig. 8 is described in detail. In the embodiment shown, the pressure equalization element 12 is arranged in an opening of an upper battery housing element 14. It allows gaseous fluids, in particular ambient air, to flow from an environment U into a sealed space 16, here in the form of a sealed battery compartment 16, which extends between the upper battery housing element 14 and a lower battery housing element 18.

[0022] In an opening of the lower battery housing element 18, a pressure relief valve 20 is arranged, which allows pressure equalization to the environment U in case of overpressure in the sealing chamber 16.

[0023] For the sake of completeness, it should also be noted that the sealed battery compartment contains 16 battery cells (not shown) of a motor vehicle's drive energy storage system. In particular, these battery cells (not shown) are also battery cells of a high-voltage drive energy storage system, which provides an operating voltage between 48 V and 1,200 V, specifically an operating voltage between 200 V and 800 V.

[0024] In the Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7 to Fig. Figure 8 shows the pressure equalization element 12 according to the invention in various operating states and partly in enlarged partial views.

[0025] The pressure equalization element 12 essentially consists of a housing base element 22, which in the illustrated embodiment is formed in two parts and comprises a housing base body 24 and a mounting sleeve 26. A flow section 28 is formed in the housing base element 22, which leads from an environment U to a sealing chamber 16 when the pressure equalization element 12 is installed as intended. The flow section 28 has an inlet side E and an outlet side A.

[0026] Furthermore, a cover 30 is provided that covers the inlet side E. In the embodiment shown, the cover 30 has a U-shaped cross-section and completely encloses the surrounding side of the housing base element 22 with the inlet side E. This means that the inlet side E is completely covered on its upper side by the cover 30. The U-shape of the cover 30 results from the central section 32 of the cover 30 and the side surfaces 34 that extend transversely to the central section 32 from its outer sides in a leg-like manner.

[0027] As in Fig. As can be clearly seen in Figure 2, the cover 30 is positively locked to the mounting sleeve 26 by being pushed onto it. The cover 30 is removable so that it can be taken off if necessary.

[0028] The mounting sleeve 26 is also positively locked to the housing base body 24. To fix the mounting sleeve 26 to the housing base body 24, several flexible locking elements 36 are formed on the housing base body 24, which are located in the Fig. 2 shown in the assembled state with a shoulder 38 formed on the mounting sleeve 26.

[0029] A valve element 40 is arranged in the housing body 24, which is designed to open the flow section 28 in the case of negative pressure in the sealing chamber 16 and to close the transition to the sealing chamber 16 in the case of positive pressure or without pressure difference.

[0030] In Fig. Figure 2 shows the pressure equalization element 12 under negative pressure in the sealing chamber 16. In this state, a disc-shaped sealing section 42 is deformed elastically such that a gap s forms between an inner wall 44 and the disc-shaped sealing section 42 to allow a fluid flow according to the conditions shown in Figure 2. Fig. 2 and Fig. To enable the 3 arrows shown F.

[0031] In the area of ​​the outlet opening, the housing body 24 is sealed to prevent the passage of solids by means of a membrane 46. The membrane 46 is designed as a planar element and lies flat against a flange-like outer surface 48 of the housing body 24. The membrane 46 is permeable only to gases, but not to solids. Preferably, the membrane 46 is also impermeable to liquids. The membrane 46 therefore effectively prevents the ingress of dirt or other particles, and optionally and preferably also the ingress of liquids, in particular rainwater and splash water from the environment U into the sealing chamber 16. The membrane 46 is thus semipermeable.

[0032] As in Fig. As can be clearly seen, one or more locking elements 50 are formed on the valve element 40 in order to be able to mount the valve element 40 by simply inserting and locking it against a shoulder 52 formed on the housing base body 24.

[0033] In the embodiment shown, the valve element 40 is manufactured in one piece. It is preferably made of a flexible material, in particular rubber or silicone.

[0034] In Fig. Figure 2 further shows that a sealing element 54 in the form of a sealing ring 56 is arranged between the housing base body 24 and the mounting sleeve 26. A groove-like recess 58 is formed on the housing base body 24 as a sealing element section to fix the sealing ring 56 in position.

[0035] The assembly of a pressure equalization element 12 according to the invention can be carried out in a particularly simple manner as follows: First, the housing base body 24 can be moved in the direction of the Fig. The housing base body 24, indicated by arrow 1, is inserted into an opening of a component 60. There, the housing base body 24 can be pre-fixed, in particular with the aid of a sealing element 62. Such pre-fixation with the aid of a sealing element 62 can be achieved, in particular, by overmolding a flange-like end section 64 of the housing base body 24.

[0036] The valve element 40 can already be inserted into the housing base body 24 before assembly or inserted into it afterwards.

[0037] The mounting sleeve 26 can then be inserted from the other side of the component 60 according to arrow 2. Fig. 1. The housing base 24 and the mounting sleeve 26 are pushed together in such a way that the locking elements 36 of the housing base 24 lock into the shoulder 38 of the mounting sleeve 26.

[0038] The cover 30 can be subsequently attached to the mounting sleeve 26 or pre-assembled. The sealing ring 56 can also be pre-assembled when the housing base 24 is inserted or installed after it has been pushed through the opening in the component 60.

[0039] The Fig. 4 and Fig. Figure 5 shows the pressure equalization element 12 according to the invention under the same pressure conditions in the sealing chamber 16 and the environment U or under overpressure in the sealing chamber 16. In this state, the valve element 40 is in the closed position, which can be seen from the fact that the disc-shaped sealing section 42 rests against the inner wall 44 of the housing base body 24.

[0040] In the Fig. 6 and Fig. Figure 7 shows the pressure equalization element 12 according to the invention during a test situation in which a test device 66 with a pressure plunger is inserted from above into the flow section 28 with the cover 30 removed. As in Fig.As can be seen in Figure 6, the test device 66 has a stamp-like projection 68. Furthermore, a sealing element 70 is provided, which seals the area between a plate-shaped system section 72 and the mounting sleeve 26.

[0041] When the test device 66 is inserted from above into the flow section 28 with the cover 30 removed and pressed against the valve element 40, the valve element 40 is displaced towards the sealing chamber 16, causing the disc-shaped sealing section 42 to move away from the inner wall 44 of the housing body 24. This in turn creates a gap s between the disc-shaped sealing section 42 and the inner wall 44, allowing fluid to flow in the direction indicated by arrows F.

[0042] The test device 66 has an opening 74 through which it can be determined whether fluid flows out of the test device 66 in accordance with arrows F. By generating overpressure in the sealing chamber 16 and using the test device 66, it can be verified whether the valve element 40 functions reliably and whether the fluid flow is interrupted when the test device 66 is not actuated. If this is not the case, the valve element 40 or the entire housing body 24 with the valve element 40 inserted must be replaced, if necessary, or made functional again or repaired.

[0043] The pressure equalization element 12 according to the invention enables pressure equalization in a vehicle battery system in one direction in a simple and easy-to-install manner. This is particularly advantageous when pressure equalization in the other direction is to be, or must be, carried out at a different location. The pressure equalization element 12 according to the invention thus makes it possible to overcome design challenges that require the arrangement of pressure equalization elements for overpressure and underpressure at different locations within a vehicle battery system.

[0044] The features of the invention disclosed in the present description, the drawings, and the claims can be essential for realizing the invention in its various embodiments, both individually and in any combination. The invention can be varied within the scope of the claims and taking into account the knowledge of the person skilled in the art. Reference symbol list 1 arrow 2 Arrow 10 Vehicle battery system 12 Pressure equalization element 14 upper battery housing element 16 Sealed compartment / sealed battery compartment 18 lower battery housing element 20 Pressure relief valve 22 Housing base element 24 Housing base bodies 26 Mounting sleeve 28 Flow section 30 lids 32 Middle section 34 side surfaces 36 locking elements Paragraph 38 40 Valve element 42 Sealing section 44 Interior wall 46 Membran 48 outside 50 locking elements Paragraph 52 54 Sealing element 56 Sealing ring 58 In-depth study 60 building elements 62 Sealing element 64 Final section 66 Testing device 68 lead 70 Sealing element 72 Plant section 74 Opening A Outlet side E Inlet side F arrow U surroundings s gap

Claims

[1] Pressure equalization element (12) for a battery system, comprising a housing base element (22) which has a flow section (28) leading from an environment (U) to a sealing chamber (16) with an inlet side (E) and an outlet side (A), with a cover (30) arranged on the environment side of the housing base element (22) covering the inlet side (E), which is removable so that it can be taken off if necessary, and with a valve element (40) arranged in the housing base element (22), which is designed such that it opens the flow section (28) when there is negative pressure in the sealing chamber (16) and closes it when there is positive pressure in the sealing chamber (16), wherein an outlet opening from the housing base element (22) downstream of the valve element (40) is closed by means of a diaphragm (46), characterized by , that the valve element (40) can be brought into an open position for a test situation by means of a test device (66) with the cover (30) removed. [2] Pressure equalization element (12) according to the preceding claim, characterized by , that the valve element (40) is made of an elastic material and that opening under negative pressure is achieved by elastic material deformation of the valve element (40). [3] Pressure equalization element (12) according to one of the preceding claims, characterized by , that the valve element (40) is locked into the housing base element (22). [4] Pressure equalization element (12) according to one of the preceding claims, characterized by , that at least one plate-shaped sealing section (42) and / or a collar-shaped locking element (50) is formed on the valve element (40) itself. [5] Pressure equalization element (12) according to one of the preceding claims, characterized by , that the valve element (40) is formed in one piece. [6] Pressure equalization element (12) according to one of the preceding claims, characterized by, that the housing base element (22) is formed in at least two parts and consists of a housing base body (24) and a mounting sleeve (26) functionally connected to it. [7] Pressure equalization element (12) according to the preceding claim, characterized by , that a sealing element (54) is arranged between the housing base body (24) and the mounting sleeve (26). [8] Pressure equalization element (12) according to one of the preceding claims, characterized by , that the cover (30) has a U-shaped cross-section and the cover (30) is arranged to enclose the surrounding side of the housing base element (22). [9] Vehicle battery system (10) with a sealed battery compartment (16) which is closed in the direction of an environment (U) by means of a pressure equalization element (12) according to one of claims 1 to 8 and additionally has a pressure relief valve (20) at another position which allows pressure equalization to the environment (U) or to another pressure chamber in the event of overpressure in the battery compartment (16). [10] Vehicle with a pressure equalization element (12) according to any one of claims 1 to 8 and / or with a vehicle battery system (10) according to the preceding claim.

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