Method for producing a fluid-tight threaded connection on a profile, profile and battery box

Abstract

The invention relates to a method for producing a fluid-tight threaded connection (100) on a profile (106), wherein a screw (102) is screwed into a chamber (112) of the profile (106) behind a wall (114) of the profile (106) through the wall (114), so that a threaded opening is formed in the wall (114), wherein a sealant (116) is arranged in the chamber (112), the screw (102) is screwed into the sealant (116) when being screwed in, and the sealant (116) is thereby partially pressed by the screw (102) when being screwed in, and the pressed sealant (116) is located around the screw (102) and into the threaded opening, so that the threaded connection (100) is sealed by the sealant (116).

Description

Technical Field

[0001] This invention relates to a method for creating a fluid-sealed threaded connection on a profile, the profile itself, and a battery box. Background Technology

[0002] The invention will now be described primarily in conjunction with the battery box of an electric vehicle.

[0003] The battery box should be waterproof. To this end, the various parts of the battery box can be interconnected, for example, by bonding materials together to form a continuous package. For example, the parts can be welded together.

[0004] However, the welded battery box can be an obstacle during maintenance.

[0005] Alternatively, the battery box can be assembled from individual parts and then sealed with a waterproof coating. For example, wax can be sprayed onto the battery box to form the coating.

[0006] Coating is a complex process in which certain parameters must be strictly adhered to to ensure a reliable seal for the battery compartment.

[0007] The various parts of the battery compartment can also be screwed together with a central sealing ring. However, over time, water may seep into the parts through the threaded connections. To prevent water ingress, the threaded connections can be sealed with a waterproof coating. Summary of the Invention

[0008] Therefore, the technical problem to be solved by the present invention is to provide an improved method for producing fluid-tight threaded connections on a profile, an improved profile, and an improved battery box, using the simplest possible design means. For example, improvements may involve improved sealing of the threaded connection to prevent liquid penetration and / or simplified process control.

[0009] In the proposed scheme, a screw is screwed into a sealant disposed within the profile wall. Here, the sealant is partially compressed by the screw. The rotation of the screw causes friction between the sealant and the screw, thereby heating both. Due to the localized thermal effect, the sealant may partially liquefy or plasticize and adhere to the screw. Due to the restoring force of the sealant, the liquid sealant can also penetrate the threaded connection between the screw and the profile, thereby sealing the threaded connection. Alternatively, the restoring force can be such that the elastic sealant molds against the screw or threads, thereby sealing the threaded connection.

[0010] To prevent sealant from easily overflowing, the sealant is placed within a cavity in the profile. The cavity also limits the amount of sealant required and helps limit weight.

[0011] A method for creating a fluid-sealed threaded connection on a profile is proposed, wherein a screw penetrates the wall of the profile and is screwed into a profile cavity located behind the wall, thereby forming a threaded opening on the wall. A sealant is arranged in the cavity, and the sealant is screwed in as the screw is screwed in. During this process, the sealant is partially squeezed as the screw is screwed in, and the squeezed sealant is located around the screw and the threaded opening, thereby sealing the threaded connection with the sealant.

[0012] In addition, a profile is proposed having at least one cavity located behind the profile wall, in which a sealant can be arranged so that the sealant can be partially squeezed when the screw is screwed in, the squeezed sealant being located around the screw and the threaded opening on the wall.

[0013] Furthermore, a battery box for an electric vehicle is proposed, wherein the battery box includes at least one profile according to the invention, wherein at least one screw penetrates the wall of the profile and is screwed into a cavity, wherein the screw is screwed into a sealant, and the threaded connection on the profile is fluidly sealed by the sealant.

[0014] The profile can be a frame profile for the battery compartment. For example, the profile can be made of metallic materials, particularly aluminum or steel. The profile can be, for example, an extruded profile or a drawn profile. The profile can be an open profile or a closed profile. The profile can have a substantially constant cross-sectional geometry along the main direction of extension. For example, the profile may also have cutouts for weight considerations.

[0015] The battery box can be composed of multiple such profiles and other individual components. In particular, the individual components can be pressed onto the profiles as clamping elements of the threaded connections described herein. The profiles can also be connected to each other using the proposed threaded connections. The battery box is designed to enclose the battery modules of electric vehicles and protect them from environmental and mechanical influences. The battery box can be part of the electric vehicle's crash structure.

[0016] The cavity can be manufactured directly during the profile production process. The cavity can be integrally connected to the profile. The cavity can extend substantially along the length of the profile. At least one wall of the cavity can be formed from the outer wall of the profile. The walls of the cavity can be formed from the same material as the walls of the profile. If the cavity is located at the edge of the profile, at least two walls of the cavity can also be formed from the outer wall of the profile.

[0017] Screws can be standard screws and can be screwed into existing threads in a wall. Screws can also be self-tapping and screwed into a fitting mandrel in a profile. Self-tapping screws can form threads in a wall. Screws can also be self-drilling and self-tapping screws, which can independently drill holes in the wall and form threads therein.

[0018] The sealant can be a durable, elastic material. It can adhere to the chamber walls. The sealant can be placed inside the chamber before the battery box is manufactured. Alternatively, the sealant can be pre-placed inside the chamber by the profile manufacturer. The sealant can have thermoplastic properties. When the screw is screwed in, the sealant can be heated and liquefied through friction. The liquefied sealant can wet the screw and create an adhesive effect. Adhesion occurs particularly when the sealant cools and hardens or solidifies. The liquefied sealant can also penetrate the threaded connection and harden there. Alternatively or additionally, the sealant can be squeezed by the screw, particularly laterally, and a restoring force can be generated against the squeeze. This restoring force can press the sealant onto the screw and seal it. Furthermore, particles generated during screwing can be trapped within the sealant.

[0019] Screws can clamp clamping components onto a profile. Similarly, screws can be screwed into the profile without clamping components. Screws can also clamp multiple stacked clamping components onto the profile. Clamping components can be, for example, the cover or bottom of a battery compartment. A sealant can be disposed between the clamping components and the profile. The sealant can be the same sealant used in the chamber. The clamping components can have screw holes through which the screw is screwed into the profile. The location of the threaded connection can be determined by the screw holes in the clamping components. Screws can also pass through clamping components without holes and then through the profile before being screwed in. The screw head can rest on the clamping component, pressing the clamping component against the profile. A sealing washer can be placed between the head and the clamping component. The sealing washer can be made of a ductile material and can at least partially mold the contour of the clamping component. The sealing washer can be made of, for example, aluminum.

[0020] The sealant can also be metered into the chamber before screwing it in. The sealant can be metered in a flowable or paste-like state. For example, the sealant can be heated and then cooled and hardened within the chamber. The sealant can be metered into the cut profile. The sealant can be metered using a metering device. The sealant can be introduced into the chamber through a nozzle located on the surface of the profile. Alternatively, the sealant can be metered using a spray gun inserted into the chamber. The nozzle can be located at the end of the spray gun. The spray gun can move along the chamber while metering the sealant. In particular, the sealant can be metered as the spray gun is withdrawn from the chamber.

[0021] During the metered dispensing process, the chamber can be almost completely filled with sealant. The sealant can be filled from one end of the chamber to the other. This allows for fluid-tight threaded connections anywhere within the chamber.

[0022] The sealant can be metered locally into the chamber at the threaded connection. The location of the threaded connection can be predetermined. The sealant can be metered at the threaded connection location in portions. Therefore, air or protective gas can be arranged in the chamber between portions. Sealant can be saved by distributing portions along the chamber. The chamber can be filled only in the area around the threaded connection. A predetermined distance before and after the threaded connection can be filled with sealant. For example, a nozzle or spray gun can be pulled across the chamber, and sealant can be metered from the nozzle or spray gun into the threaded connection area of ​​the chamber. The metering can be interrupted between two threaded connections.

[0023] The sealant can be metered into the chamber through a profile opening extending along the chamber. The profile opening extends along the chamber, penetrating both the chamber wall and the outer wall of the profile. Here, the chamber wall can also be the outer wall of the profile. The chamber wall and the outer wall of the profile can also be spaced apart from each other. The profile opening can then have a wall connecting the chamber wall and the outer wall of the profile. Due to the profile opening, the chamber wall is essentially C-shaped. An application nozzle can be inserted into the chamber through the profile opening to meter the sealant. Therefore, the sealant can be metered into the chamber, particularly locally in the threaded connection area. During metering, the application nozzle can move along the profile opening, and the sealant can be metered from the application nozzle into the chamber in the threaded connection area.

[0024] Butyl material can be metered into the chamber as a sealant. Butyl or butyl-based materials possess permanent elasticity and exhibit excellent adhesion to metals, particularly at elevated temperatures. Butyl material can be easily metered from the nozzle. For this purpose, the butyl material can be heated, for example, to a temperature between 130°C and 150°C. In the heated state, the butyl material is in a paste-like state and is plastically deformable. Inside the chamber, the butyl material can be cooled again and hardened to a permanently elastic state. Butyl material is reusable. Alternatively, sponge rubber can also be used as a sealant.

[0025] As the screw is screwed in, it can laterally compress the material of the wall, drill through the wall, and form threads in the compressed material. The screw can be a flow drill screw. The tip of the screw can be placed on the continuous wall of the profile, rotated, and pressed against the wall. Here, the wall is locally heated due to friction until the metal material of the profile becomes flowable. The pressure causes the tip to laterally compress the material of the wall, forming a ring-shaped thickened portion of the wall as it is penetrated. Ideally, the compression is done without cutting. Once the tip has penetrated the wall, it enters the subsequent sealant and essentially compresses the sealant laterally. Fragments that may be generated during the penetration process can be embedded in the sealant within the cavity. The screw shank adjacent to the tip has a conical external thread, which is pressed out or forms an internal thread in the still flowable thickened portion. Ideally, the formation of the thread also does not require cutting. Fragments that may be generated during the thread forming process can be embedded in the sealant within the cavity. The cylindrical portion of the external thread adjacent to the tapered thread engages with the newly formed internal thread, pulling the screw head adjacent to the cylindrical thread in the profile direction. Here, the clamping member located between the screw head and the thread can be pressed against the profile. The hot tip and the also heated tapered portion of the thread heat the sealant during penetration. Friction between the entire screw and the sealant further increases the heat generated by the sealant. The sealant locally and in a limited manner liquefies and wets the hot screw. Lateral displacement of the liquid sealant is hindered by the adjacent cold sealant, and high pressure is generated in the liquid sealant. Due to the high pressure, the liquid sealant is also forced into the gap between the internal thread of the profile and the external thread of the screw, thereby permanently sealing the threaded connection. Attached Figure Description

[0026] An advantageous embodiment of the invention will now be explained with reference to the accompanying drawings. Wherein:

[0027] Figure 1 A cross-sectional view of a fluid-sealed threaded connection according to an embodiment of the present invention is shown; and

[0028] Figure 2 The quantitative dispensing of a sealant according to one embodiment of the present invention is shown.

[0029] These figures are merely illustrative and are intended to explain the invention. Elements with the same or similar functions use the same reference numerals throughout. Detailed Implementation

[0030] Figure 1A cross-sectional view of a fluid-tight threaded connection 100 according to one embodiment is shown. A screw 102 is screwed into a screw hole in a profile 106 at the threaded connection 100. The screw 102 has external threads. The screw hole has internal threads 104. The profile 106 is a frame profile of a battery box 108 for an electric vehicle. The screw 102 presses a clamping member 110 onto the profile 106. The clamping member 110 is, for example, a cover for the battery box 108.

[0031] Profile 106 is an extruded or drawn profile made of aluminum or steel. Profile 106 has a substantially constant cross-section along its main extension direction. In this case, profile 106 may also be bent, for example, in areas where its cross-section may be altered.

[0032] Profile 106 has a cavity 112 that extends along the entire length of profile 106. At least one wall 114 of cavity 112 is the outer wall of profile 106. Screw holes are located in wall 114. At threaded connection 100, screw 102 is screwed into cavity 112 through clamping member 110 and through wall 114. Internal thread 104 is formed in wall 114. Clamping member 110 is pressed against wall 114 by screw 102.

[0033] In the proposed solution, a sealant 116 is arranged in the chamber 112, at least in the region of the threaded connection 100. A screw 102 is screwed into the sealant 116. The screw 102 at least partially compresses the sealant 116 laterally. The compressed sealant 116 contacts the screw 102 and the screw hole, and fluid-tightly seals the threaded connection 100.

[0034] When the screw 102 is screwed into the sealant 116, the sealant 116 is heated at least partially due to the friction between the sealant 116 and the screw 102. In its liquid state, the sealant 116 wets the screw 102 and penetrates at least partially into the thread between the internal thread and the screw 102. In the middle. The sealant 116 adheres to the surface of the screw 102 and the internal thread, thereby sealing the thread.

[0035] In one embodiment, the threaded connection 100 is a direct threaded connection. In a direct threaded connection, the screw 102 has penetrated the non-pre-drilled wall 114, forming a screw hole and internal threads. In a direct threaded connection, the screw 102 may also optionally penetrate the clamping member 110 first. However, in the example shown, the clamping member 110 has a through hole. For a direct threaded connection, the screw 102 is placed on the profile 106 within the through hole and rotated. Here, the screw 102 can penetrate the wall 114 in a non-cutting or cutting manner. A sealant 116 disposed behind the wall 114 permanently binds any debris that may occur during the direct threaded connection process.

[0036] As the screw 102 penetrates the wall 114, the friction between the screw 102 and the wall 114 heats both. The heated wall 114 softens, allowing the screw 102 to penetrate. As it penetrates, the screw 102 compresses the metal material of the wall 114 to the side, forming an annular thickened portion 118 on the wall. The screw 102 forms an internal thread inside the thickened portion 118. The heated screw 102 then penetrates the sealant 116, which has been partially heated by the heated wall 114. This makes the sealant 116 thinner and wets the screw 102 and the internal thread 104 particularly well. Debris is also particularly well bound by the thinned-flow sealant 116.

[0037] In one embodiment, the profile 106 with the empty chamber 112 is cut to the required length for the battery case 108, and then a sealant 116 is metered into the chamber 112 prior to the threaded connection 100. The sealant 116 can be metered into the chamber 112 through the open end of the chamber 112.

[0038] In one embodiment, a spray gun with a nozzle at one end is inserted into chamber 112 from one side and pushed to the other. Sealant 116 is then metered from the nozzle, and the spray gun is withdrawn from chamber 112 at a predetermined speed. The speed is such that the sealant 116 flowing from the nozzle fills the entire cross-section of chamber 112. This substantially prevents porosity and cavitation in the sealant 116. The other end of chamber 112 can be sealed before metering begins to prevent leakage of sealant 116.

[0039] In one embodiment, the spray gun retracts through chamber 112, and sealant 116 is metered into the area of ​​the future threaded connection 100. One portion of sealant 116 is metered into each threaded connection 100. One portion fills the cross-section of chamber 112 from a short distance before to a short distance after the threaded connection 100. Between threaded connections 100, chamber 112 remains empty. Thus, the amount of sealant 116 used can be reduced compared to completely filling chamber 112.

[0040] In one embodiment, butyl material is metered into chamber 112 as sealant 116. The butyl material is metered at an elevated temperature. Due to the elevated temperature, the butyl material becomes at least viscous or pasty and can plastically fill the cross-section of the chamber. Furthermore, due to the elevated temperature, the butyl material exhibits good adhesion to the walls of chamber 112. When cooled to ambient temperature, the butyl material retains its elasticity but can no longer undergo plastic deformation. Heating during the screw-in process of screwing in the screw 102 causes the butyl material to become plastically deformable again and adhere well to the screw 102.

[0041] Figure 2 A quantitative dosing of sealant 116 according to an exemplary embodiment is shown. Figure 1 The sealant 116 is metered into the cavity 112 extending along the profile 106. Figure 1 Compared to the illustration, the profile 106 here has a profile opening 200 extending along the chamber 112. The profile opening 200 allows access to the chamber 112 at each location of the profile 106.

[0042] For metered dispensing, the application nozzle 202 or filling nozzle is inserted from the outside through the profile opening and meteredly dispenses the sealant into the chamber 112.

[0043] In one embodiment, the application nozzle 202 is inserted into the chamber 112 at one end of the profile 106 to begin metering, and during the metering process, the application nozzle 202 moves along the profile opening 200 to the other end of the profile 106. During this process, the chamber 112 is completely filled with sealant 116.

[0044] In an alternative implementation, sealant 116 is metered only to the area of ​​the future threaded connection. Metering begins shortly before the threaded connection and is adjusted or interrupted shortly after the threaded connection 100 until shortly before the next threaded connection 100 as the application nozzle moves along the profile opening 200. Between threaded connections 100, the chamber 112 remains empty. The application nozzle can move along the profile opening 200 at a constant speed.

[0045] In other words, a method is proposed to seal direct threaded connections by pre-filling a profile with sealant.

[0046] In the case of direct threaded connections, the tightness of the threads formed by the direct threaded connection cannot be guaranteed. However, in the case of battery systems, this tightness is precisely what is important, even in terms of safety. Existing screw systems, namely screws and threaded profiles, as well as process-related screw technologies, cannot provide 100% safety in terms of sealing.

[0047] The proposed solution here ensures that the required seal is achieved in the threads formed by the direct threaded connection.

[0048] By filling the provided chambers in the frame profiles where the threaded connection will later be made with sealant, the newly formed threads during the threaded connection process are automatically sealed. Soaking the screws in sealant prevents water from penetrating into the threads formed by the direct threaded connection.

[0049] If butyl is used as a sealant, the heat generated by friction during thread forming softens the surrounding butyl and causes it to adhere to the screw. The adhesion of butyl increases with temperature. This also applies to other sealants.

[0050] Therefore, spraying the surface with substances such as wax or other sealing sprays can be omitted. High-quality results can be achieved through a direct threaded connection to the sealant. The cost involved is minimal. The process is very stable and achieves good repeatability.

[0051] The methods described here are particularly suitable for battery systems, but can also be applied to other fields. High levels of process reliability, along with excellent feasibility and functional guarantees in standard industrial applications, ensure high performance. Direct threaded connections to sealant-filled chambers offer a tolerance-free, space-saving, and contamination-free solution, regardless of screw type. High levels of Technical Cleanliness (TECSA) are achieved by securing and binding any chips that may be generated during drilling and threading of self-tapping and slotted screws.

[0052] Since the apparatus and methods described in the above detailed description are embodiments, those skilled in the art can make extensive modifications to them in a conventional manner without departing from the scope of the invention. In particular, the mechanical arrangements and proportions between the various elements are merely exemplary.

[0053] Figure Labels

[0054] 100 threaded connection

[0055] 102 screws

[0056] 104 Internal Thread

[0057] 106 profile

[0058] 108 Battery Box

[0059] 110 Clamping components

[0060] 112 chambers

[0061] 114 wall

[0062] 116 Sealant

[0063] 118 Thickened section

[0064] 200 profile opening

[0065] 202 Apply nozzle

Claims

1. A method for creating a fluid-tight threaded connection (100) on a profile (106) of a battery box (108) for an electric vehicle, wherein, The screw (102) penetrates the wall (114) of the profile (106) and is screwed into the cavity (112) of the profile (106) located behind the wall (114), thereby forming a threaded opening in the wall (114). A sealant (116) is disposed in the chamber (112), wherein the profile (106) has a profile opening (200) extending along the chamber (112). Before screwing in, the sealant (116) is locally metered into the chamber (112) in portions within the area of ​​the threaded connection (100) by means of an application nozzle that can be inserted into the chamber (112) through the profile opening (200) and can move along the profile opening (200), such that air or a protective gas is disposed in the chamber (112) between portions of the sealant (116), and During screwing, the screw (102) is screwed into the sealant (116), and thus the sealant (116) is partially squeezed by the screw (102) during screwing, and the squeezed sealant (116) is located around the screw (102) and the thread opening, thereby sealing the threaded connection (100) with the sealant (116).

2. The method according to claim 1, wherein, The sealant (116) is a butyl material.

3. The method according to claim 1 or 2, wherein, The screw (102) presses the material of the wall (114) laterally during the screwing process, drills through the wall (114) and forms an internal thread (104) in the pressed material.

4. A profile (106) for a battery box (108) for an electric vehicle, having at least one chamber (112) located behind a wall (114) of the profile (106), the profile (106) having a profile opening (200) extending along the chamber (112), the chamber (112) being designed such that a sealant (116) can be distributed in portions in the area where a screw (102) is screwed in, and air or a protective gas is distributed between portions of the sealant (116), such that the sealant (116) can be partially squeezed when the screw (102) is screwed in, and the squeezed sealant (116) is located around the threaded opening in the screw (102) and the wall (114).

5. A battery box (108) for an electric vehicle, said battery box (108) having at least one profile (106) according to claim 4, wherein, At least one screw (102) is screwed into the chamber (112) through the wall (114), wherein the screw (102) is screwed into the sealant (116), and the threaded connection (100) on the profile (106) is sealed by the sealant (116) in a fluid-tight manner.

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