Housing for a battery unit

Abstract

A housing for a battery unit is proposed in which the lid element and the base element of the housing are connected not with screws, but with rivets. This allows for simple yet damage-free reversible closing of the housing.

Description

[0001] The invention relates to a housing with a base part and a lid part for a battery unit for a motor vehicle, a battery unit, a motor vehicle and a use of a plurality of impact rivets.

[0002] Battery units for motor vehicles, especially traction batteries for electric or hybrid vehicles, are typically housed in a robust, encapsulated casing within the vehicle. This casing is often made of metal. The casing has an opening, for example, on the top, through which the individual battery modules can be inserted and removed. This opening is typically closed with a cover. The part of the casing containing the opening can be referred to as the base of the casing, and the cover can be referred to as the top of the casing. The top of the casing often corresponds to its upper surface. The casing can have a roughly parallelepiped or cubic shape.

[0003] In practice, the housing lid is fastened with up to 80 or more screws. Each screw requires its own threaded connection. This results in considerable costs and time during assembly and closing of the housing, as the threads or threaded inserts for each screw must be produced and the corresponding tolerances maintained. Each screwing operation takes a relatively long time, involving the application of the screwdriver, the turning motion to tighten the screw, checking the torque if necessary, and removing the screwdriver. Cutting a thread, for example into the base of the housing, requires altering the material's structure. Furthermore, thread production is another time-consuming process that increases the overall machining time.

[0004] From CN 217271341 U, it is known to fasten a battery module to a battery housing using a rivet connection. A rivet body is inserted into a through-hole penetrating both parts to be joined. The rivet body has an upper flange, two deformation grooves in a central outer area, and an inner bore with an internal thread. A bolt is screwed into the rivet body, which pulls the shank portion of the rivet body towards the flange. In the area of ​​the deformation grooves, the rivet body deforms such that its cross-section increases. This allows the components to be clamped between the flange and the area of ​​increased cross-section, thus creating a connection between the components.

[0005] According to the prior art, complex screw connections are required in each case, which, as already explained, result in a relatively large amount of time spent assembling the battery housing. It is therefore the object of the present invention to provide a method for creating a secure and easy-to-manufacture connection between several components of a housing for a motor vehicle battery.

[0006] The object of the invention is achieved by a housing for a battery unit of the type mentioned above, wherein the base portion and the cover portion are connected to one another by a plurality of rivets, and wherein the rivets each comprise an expanding sleeve element and a rivet element. The object is further achieved by a battery unit with such a housing and by a motor vehicle with such a housing or with such a battery unit. The object is also achieved by using a plurality of rivets to connect a first metal element of a motor vehicle to a second metal element of the motor vehicle, wherein a plurality of blind holes are arranged in the first metal element, and wherein a plurality of through holes cooperating with the blind holes in the first metal element are arranged in the second metal element.

[0007] In the context of this description, a drive rivet is understood to be a multi-part fastener for joining two components, in which an inner portion of the fastener is driven into an outer portion. A hammer or other suitable tool can be used for driving. The inner and outer portions are designed to fit each other such that when the inner portion penetrates the outer portion, the latter expands or spreads open. At least a portion of the outer circumference of the outer portion increases, causing it to be clamped in a hole into which the outer portion has been inserted. This expansion of the outer portion can occur similarly to a dowel. The drive rivet can also be called a drive-in anchor or a drive-in anchor.

[0008] For the purposes of this description, an expansion sleeve element is understood to be, in particular, an elongated, typically cylindrical sleeve element with a cavity, designed to deform when a rivet element is inserted or driven into it. Specifically, this allows at least some of the circumference of the expansion sleeve element to increase. The expansion sleeve element may, for example, have longitudinal slots or other material weakenings to enable controlled deformation.

[0009] For the purposes of this description, a rivet element is understood to be, in particular, a nail- or screw-like element that has a shank portion designed to expand an expanding sleeve element when it penetrates it. The shank portion may, for example, have a thickened section for this purpose. The rivet element may also have a flange or a nail head at one end.

[0010] The housing according to the invention can be closed particularly quickly. For this purpose, the housing can have holes in both the base and the lid sections into which the expanding sleeve element can be inserted. Preferably, the hole in the base section is designed as a blind hole. It is also advantageous for the hole in the lid section to be designed as a through hole. The two holes can expediently have the same diameter. The holes can be designed as simple bores. In particular, it is not necessary to cut a thread into the holes or to insert a threaded insert. Expediently, the holes in the base section and the holes in the lid section are designed to be congruent, so that the two holes complement each other to form a larger or longer hole.The expansion sleeve element may have a flange or other stop element which limits the penetration depth of the expansion sleeve element into the respective hole.

[0011] The rivet element can then be inserted into the expansion sleeve element, in particular by driving it in. The resulting clamping effect, especially in the hole in the base part of the housing, creates a secure connection between the base part and the cover part of the housing through interaction with the flange or the stop element and / or a possible clamping effect in the hole in the cover part of the housing.

[0012] The housing according to the invention has the advantage that no thread needs to be cut into either or both of the housing parts. In other words, two identical bores in the lower part (base part) and the upper part (cover part) are sufficient to create the described connection using impact riveting. This offers particular advantages because no costly production of threads or threaded inserts is necessary. Furthermore, the required tolerances are larger, which simplifies manufacturing and thus reduces costs. A time-consuming screwing process is also unnecessary, and there is no alteration to the material structure, since no thread needs to be cut.

[0013] The rivets, and therefore the holes, can be arranged around the circumference of the cover element. Alternatively, or simultaneously, the rivets, and therefore the holes, can be arranged in the area(s) where the base element is in contact with the cover element.

[0014] A further development of the invention provides that the expansion sleeve elements and / or the rivet elements each have an external thread. This makes it possible to unscrew the rivet elements and / or the expansion sleeve elements from the housing. This allows for an easily detachable connection. Thus, a connection is formed between the rivet elements and the expansion sleeve elements that can be released by unscrewing the rivet elements from the expansion sleeve elements.

[0015] By using re-screwable drive rivets, which allow for installation by hammering and removal by screwing, the upper housing part or the cover portion can be disassembled without damaging the battery housing—in other words, the lower part or the base portion of the housing. According to the invention, a conventional screw connection can thus be replaced by a drive rivet connection with re-screwable drive rivets. If the drive rivet is also equipped with a thread, it is also possible to unscrew it from the dowel or the expansion sleeve element when it becomes necessary to open the battery cover, thereby releasing the connection. As with a classic screw connection, the cover can thus be disassembled without damaging the cover or the lower part.

[0016] The expansion sleeve elements can be made of plastic, or alternatively, of metal or a metal alloy. Similarly, the rivet elements can be made of metal, plastic, or a metal alloy. Depending on the material used, the strength of the connection can be adjusted, and at the same time, production costs can be reduced by selecting relatively inexpensive materials, such as plastic.

[0017] It is advantageous for the rivet elements or the expansion sleeve elements to each have a drive element for a screw tool. If the rivet elements have a drive element for a screw tool, they can be unscrewed from the expansion sleeve elements to release the connection. If the expansion sleeve elements have a drive element for a screw tool, they can be unscrewed from the housing to release the connection. A drive element for a screw tool is understood to be, in particular, a screw head, a slotted head, a Phillips head, a Torx head, an internal hexagon, or an external hexagon. The screw tool can be, in particular, a screwdriver, a wrench, or a tool of a screw-driving robot.

[0018] Advantageously, the rivet elements can have a shank with a thickened section for expanding the expansion sleeve elements. This allows the connection to be made easily by driving the rivet element into the expansion sleeve element. Alternatively or additionally, the rivet elements can have a point or a tapered end section at one end. This allows the expansion sleeve element to be expanded when the rivet element is driven in.

[0019] When using most drive rivets, it is possible that the blind holes and / or through holes have an internal thread. If, for example, the through holes have an internal thread, the outer surface of the expanding sleeve element can deform when the rivet is driven into the sleeve element, adapting to the existing internal thread and thus creating a screw-removable connection. In this way, an existing housing, such as a battery housing, which previously had screw connections, can be quickly and reversibly closed using drive rivets. The blind holes and through holes can be aligned with each other. In other words, a blind hole can be positioned as an extension of a corresponding through hole.

[0020] When using multiple drive rivets, the first metal element can be a base component of a housing for a battery unit for a motor vehicle, and the second metal element is a cover component of the housing. As already described, the use of the drive rivet according to the invention is particularly advantageous here, since the joining technology according to the invention can be applied to existing components, for example, to battery housings in a recycling process.

[0021] Exemplary embodiments of the invention are explained in more detail with reference to the drawings and the following description. The drawings show: Fig. 1: A perspective exploded view of a first embodiment of a housing according to the invention, Fig. 2: a schematic partially cutaway side view of a section of a housing according to the invention in a first state, Fig. 3: the cutout in the housing from Fig. 2 in a second state, Fig. 4: an alternative design of a rivet element for connecting the base part of the housing to the cover part, Fig. 5: a partially cut-away side view of a section of a second embodiment of a housing according to the invention in a first state, and Fig. 6: the excerpt of the second embodiment from Fig. 5 in a second state.

[0022] Fig. Figure 1 shows a perspective exploded view of a first embodiment of a housing 2 according to the invention for a battery unit 4. The battery unit 4 consists of several electrically interconnected battery modules 5. The housing 2 comprises a base part 6, which is essentially formed by four side walls, a bottom plate 7, and a cover part 8. The cover part 8 is designed as a plate-like, rectangular cover and can be made of sheet metal. The cover part 8 has a plurality of through holes 10. The through holes 10 are distributed around the perimeter of the cover part 8 and are uniformly spaced apart. Blind holes 12 are arranged in a top surface of the base part 6, corresponding to the through holes 10. In conventional designs, threads would be cut into these blind holes or threaded inserts would be used, which is not necessary according to the invention.Instead, when assembling the housing 2, a drive rivet, described in more detail below, can be inserted into each hole formed by arranging a through hole 10 over a corresponding blind hole 12 to create the connection.

[0023] Fig. Figure 2 shows a schematic, partially cutaway side view of a section of a housing 2 according to the invention. Part of the base portion 6 and part of the cover portion 8 are shown. It can be seen that the through-hole 10 of the cover portion 8 is located directly above the blind hole 12 of the base portion 6. In the illustrated embodiment, the diameter of the through-hole 10 is slightly smaller than the diameter of the blind hole 12. In the illustrated state, the drive rivet 16 is inserted into the blind hole 12 but has not yet been fastened therein. The drive rivet 16 consists of an expanding sleeve element 18 and the rivet element 20. The expanding sleeve element 18 forms an outer portion of the drive rivet 16, and the rivet element 20 forms an inner portion of the drive rivet 16. The rivet element 20 has a shank portion 34 and a head 22. The rivet element 20 has a greater overall length than the expansion sleeve element 18.In the illustrated state, the rivet element 20 has been inserted into the expansion sleeve element 18 along a longitudinal axis and protrudes from the expansion sleeve element 18 with an upper end, in other words a part of its shaft portion 34 and with the head 22.

[0024] The expansion sleeve element 18 essentially consists of a dowel-like, hollow cylindrical dowel portion 42 and the flange 24. The flange 24 is arranged at the upper end of the dowel portion 42 and forms a stop when the drive rivet 16 is inserted into the blind hole 12. A lower surface of the flange 24 rests on a top surface of the cover portion 8, and the dowel portion 42 penetrates the through hole 10. In a lower portion, opposite the flange 24, the dowel portion has a slot 26 that allows the dowel portion 42, and thus the expansion sleeve element 18, to expand. For this purpose, the rivet element 20 can be driven into the expansion sleeve element 18.

[0025] Fig. Figure 3 also shows the section of housing 2 from Fig. 2, whereby the rivet element 20 was now driven into the expansion sleeve element 18. This created the connection between the base part 6 of the housing 2 and the cover part 8. It can be seen that the rivet element 20 in the Fig. 3 compared to the state in Fig. The rivet element 20 was displaced downwards, so that its head 22 is now flush with the top surface of the flange 24. Simultaneously, the tip 28 located at the lower end of the rivet element 20 penetrated the underside of the dowel portion 42 or the expansion sleeve element 18, causing the slot 26 to widen and thus the dowel portion 42 or the lower portion of the expansion sleeve element 18 to widen. The outer surface of the expansion sleeve element 18 thereby came into contact with an inner surface of the blind hole 12, forming a frictional connection with the blind hole 12.

[0026] In an alternative embodiment, the dowel portion 42 can also be designed without a slot 26. Likewise, it is possible that the rivet element 20 does not have a point 28. Instead, it is possible that the rivet element 20 has a thickened portion of its shank 34, which, when the rivet element 20 is driven into the expansion sleeve element 18, can cause the dowel portion 42 to expand. For this purpose, the dowel portion 42 can have a smaller inner diameter in a portion adjacent to the flange 24 than in a portion adjacent to the flange 24.

[0027] Fig. Figure 4 shows an alternative embodiment of a drive rivet 16 for connecting the base portion of the housing to the cover portion. The drive rivet 16 consists, as previously described, of the expansion sleeve element 18 and the rivet element 20. The expansion sleeve element 18 again comprises the dowel portion 42 and the flange 24. Here too, a slot 26 is provided in the dowel portion 42, extending longitudinally along the dowel portion 42 and facilitating the expansion of the expansion sleeve element 18. In contrast to the rivet element 20 described above, in the illustrated embodiment the shank portion 34 of the rivet element 20 has an external thread 36. Furthermore, the head 22 is not designed like a nail head, but rather as a gripping element for a screwdriver. The head 22 has an external hexagon 38, so that, for example, an open-end wrench or a ratchet wrench can engage the head 22.The head 22 also has an internal hexagon 40, so that, for example, an Allen key or a screwdriver with a corresponding bit or other suitable screw tool can be used.

[0028] By means of the interaction of the external thread 36 with the head 22, which has the engagement element for the screw tool, the rivet element 20 can be unscrewed from the expansion sleeve element part 18. This allows the connection formed by driving in the rivet element 20 to be undone without damaging the housing. For example, battery modules can then be replaced or serviced, and subsequently new drive rivets 16 can be used to re-close the housing.

[0029] The Fig. 5 and Fig. Figures 6 each show a partially cutaway side view of a section of a second embodiment of a housing 2 according to the invention. The embodiment shown essentially corresponds to the one described in the Fig. 2 and Fig.3. In contrast to the embodiment shown, the blind hole 12 has an internal thread 32. This allows the connection between the base part 6 and the cover part 8 to be released after the rivet element 20 has been driven in, by unscrewing the expanding sleeve element 18 together with the rivet element 20 from the blind hole 12. Such a situation can occur in particular when a housing is opened and resealed, for example, in a recycling, refurbishment, or other reuse process. Such a conventional housing often already has the aforementioned internal thread 32, as it has been closed in a known manner using screw connections. After unscrewing the screws, the housing 2 can then be resealed using the described drive rivets 16. Reference symbol list 2 cases 4 battery units 5 battery module 6 Basic share 7 Base plate 8 lid share 10 through hole 12 blind hole 14 side wall 16 rivets 18 expansion sleeve element 20 rivet elements 22 heads 24 flange 26 slots 28 peak 30 Opening 32 internal threads 34 shaft portion 36 external threads 38 External hexagon 40 Hex socket 42 dowel proportion QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] CN 217271341 U

[0004]

Claims

[1] Housing (2) for a battery unit (4) for a motor vehicle, comprising a base part (6) and a cover part (8), wherein the base part (6) and the cover part (8) are connected to each other by a plurality of rivets (16), and wherein the rivets (16) each comprise an expanding sleeve element (18) and a rivet element (20). [2] Housing (2) according to one of the preceding claims, wherein the expansion sleeve elements (18) and / or the rivet elements (18) each have an external thread (36). [3] Housing (2) according to one of the preceding claims, wherein the riveting elements (20) or the expanding sleeve elements (18) each have an engagement element (38, 40) for a screw tool. [4] Housing (2) according to one of the preceding claims, wherein the rivet elements (20) have an external thread (36) and form a connection with the expansion sleeve elements (18) which can be released by unscrewing the rivet elements (20) from the expansion sleeve elements (18). [5] Housing (2) according to one of the preceding claims, wherein the rivet elements (20) have a shaft (34) with a thickened section for expanding the expansion sleeve elements (18). [6] Battery unit (4) with a housing (2) according to one of the preceding claims. [7] Motor vehicle with a housing (2) according to any one of claims 1 to 6 or a battery unit (4) according to claim 7. [8] Use of a plurality of rivets (16) to connect a first metal element of a motor vehicle to a second metal element of the motor vehicle, wherein a plurality of blind holes (12) are arranged in the first metal element, and wherein a plurality of through holes (10) cooperating with the blind holes (12) in the first metal element are arranged in the second metal element. [9] Use of a plurality of rivets (16) according to claim 8, wherein the blind holes (12) and / or the through holes (12) have an internal thread (32). [10] Use of a plurality of rivets (16) according to claim 8 or 9, wherein the first metal element is a base part (6) of a housing (2) for a battery unit (4) for a motor vehicle, and wherein the second metal element is a cover part (8) of the housing (2).

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