Method and apparatus for producing fluid-tight threaded connections on profiles

Abstract

The invention relates to a method for producing a fluid-tight threaded connection (100) on a profile (106), wherein a sealing agent (116) is dosed into a chamber (112) behind a wall (114) of the profile (106) through a hole (115) in the wall (114), a screw (102) is screwed into the chamber (112) through the hole (115), wherein the screw (102) is screwed into the sealing agent (116) during the screwing in, the sealing agent (116) is partially pressed by the screw (102) during the screwing in, the pressed sealing agent (116) is placed around the screw (102) and the hole (115), and thus the threaded connection (100) is sealed by the sealing agent (116).

Description

TECHNICAL FIELD

[0001] The invention relates to a method for producing a fluid-tight threaded connection on a profile, a corresponding device and a corresponding computer program product. BACKGROUND

[0002] The invention is described below mainly in connection with a battery box of an electric vehicle.

[0003] The battery box should be waterproof. To this end, the individual parts of the battery box can be connected to each other, for example, in material combination, so as to form a continuous wrap. For example, the individual parts can be welded together.

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

[0005] In addition, the battery box can also be assembled from individual parts and then sealed with a waterproof coating. For example, the battery box can be sprayed with wax, thus forming a coating.

[0006] The coating is a complex process in which certain parameters must be strictly adhered to in order to ensure reliable sealing of the battery box.

[0007] The individual parts of the battery box can also be threaded together with a sealing ring placed in between. However, over time, water can penetrate the individual parts through the threaded connection. In order to prevent water from penetrating, the threaded connection can be sealed with a waterproof coating. SUMMARY

[0008] The invention thus solves the technical problem of providing an improved method for producing a fluid-tight threaded connection on a profile, an improved device for producing such a fluid-tight threaded connection and a corresponding, improved computer program product using means that are as simple as possible in terms of structure. The improvement can relate to, for example, the sealing of the threaded connection for preventing the ingress of liquid and / or the improvement of the manufacturing process.

[0009] In the solution presented here, the screw is screwed through the wall of the profile into a sealant in the profile. Here, the sealant is partially pressed by the screw. The rotation of the screw causes friction between the sealant and the screw, which causes the sealant and the screw to warm up. Due to the local thermal effect, the sealant can 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, thus sealing the threaded connection. In addition, the restoring force can be so great that the elastic sealant imitates the screw or the thread form, thus sealing the threaded connection.

[0010] In order to prevent the sealant from running off, the sealant is arranged in a chamber of the profile. The chamber also limits the amount of sealant required and helps to limit the weight. In order to place the sealant in the chamber, the sealant is dosed through a hole for the screw through the wall into the chamber. The dosing can take place just before the screwing. In this way, the sealant can be dosed only where the screwing also takes place.

[0011] A method for producing a fluid-tight screw connection on a profile is proposed, in which a sealant is dosed through a hole in the wall of the profile into a chamber behind the wall and a screw is screwed into the chamber through the hole, wherein the screw is screwed into the sealant when being screwed in, whereby the sealant is partially pressed by the screw, the pressed sealant is placed around the screw and the hole, whereby the screw connection is sealed by the sealant.

[0012] The profile can be a frame profile of a battery box. The profile can consist, for example, of a metallic material, in particular an aluminum material or a steel material. 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 in the main extension direction. The profile can also be provided with recesses, for example, for reasons of weight.

[0013] The battery box can consist of a plurality of such profiles and other single parts. In particular, the individual single parts can be pressed against the profile as clamping parts of the screw connection presented here. The profiles can also be connected to one another in the case of use of the proposed screw connection. The battery box is designed for enclosing battery modules of an electric vehicle and protecting them from the environment and mechanical influences. The battery box can be part of the crash structure of an electric vehicle.

[0014] The chamber can be produced directly in the process of producing the profile. The chamber can be integrally connected with the profile. Alternatively, the chamber can be formed by an insert and the wall of the profile. The chamber can extend substantially along the length of the profile. At least one wall of the chamber can be formed by the outer wall of the profile. The walls of the chamber can be formed by the same material as the walls of the profile. If the chamber is located at an edge of the profile, at least two walls of the chamber can also be formed by the outer wall of the profile.

[0015] The sealant can be a permanently elastic substance. The sealant can have thermoplastic properties. The sealant can be dosed in a flowable or paste-like state and can cure or harden in the chamber. The sealant can adhere to the chamber wall. The sealant can be dosed by means of an application nozzle.

[0016] The chamber can have at least one hole for the sealant. The hole can be located in the outer wall of the chamber. The hole communicates the chamber with the environment of the profile. The hole can be a pilot hole for a screw. The screw is forced through the hole and cannot move laterally. The hole can be a threaded hole and can already be manufactured with a matching thread. The hole can be a core hole. The core hole can have a smaller diameter than the threaded hole. The hole can also be a dosing hole. The dosing hole can have a diameter that is adapted to the material properties of the sealant. The dosing hole can be smaller than the core hole.

[0017] The screw can be a standard screw that can be screwed onto an existing thread in the wall or the hole. The screw can also be a self-tapping or self-forming screw and can be screwed into a matching core hole in the wall. The self-tapping screw can form a thread in the wall. The screw can also be placed on the dosing hole and can enlarge the dosing hole to the diameter of the core hole.

[0018] When the screw is screwed in, the sealant can be heated and liquefied by friction. The liquefied sealant can wet and adhere to the screw. In particular, an adhesion can occur when the sealant cools and hardens or solidifies. The liquefied sealant can also penetrate into the threaded connection and harden there. Alternatively or additionally, the sealant can be pressed by the screw, in particular laterally, and a restoring force can occur. The restoring force can press the sealant against the screw and seal it. In addition, particles that occur during the screwing-in process can be bound in the sealant.

[0019] During dosing, the sealant can leak out of the hole and reach the outside of the profile. The leaking sealant can seal the screw on the outside.

[0020] The screw can clamp a clamping part on the profile. Likewise, the screw can also be screwed into the profile without a clamping part. The screw can also clamp a plurality of stacked clamping parts on the profile. The clamping part can be, for example, a lid or a bottom of a battery box. Between the clamping part and the profile, a sealant can be arranged. The sealant can be the same sealant as in the chamber. The clamping part can have a screw hole through which the screw is screwed into the profile. The position of the threaded connection can be determined by the screw hole of the clamping part. The head of the screw can rest on the clamping part and press the clamping part against the profile. Between the head and the clamping part, a sealing washer can be arranged. The sealing washer can be made of a ductile material and can be at least partially profiled to the contour of the clamping part. The sealing washer can be made of, for example, an aluminum material.

[0021] During the dosing process, the chamber can be substantially completely filled with the sealing compound. The sealing compound can flow through the chamber in the opposite direction starting from the hole and fill the chamber here.

[0022] In addition, during the dosing process, the chamber can be filled locally in the region of the hole. Here, an application nozzle can be placed over each hole and a portion of the sealing compound can be dosed through the hole. This can greatly reduce the amount of sealing compound required.

[0023] The screw, when screwed in, can extrude the material on the wall to the side of the hole and form a thread in the extruded material. The screw can be a Flieβbohrschraube. The tip of the screw can be placed on the hole, rotated and pressed into the hole. Here, the wall is locally heated due to friction until the metal material of the profile becomes flowable. The pressure causes the tip to extrude the material of the wall to the side, forming a thickened portion. The thickened portion can be thicker than the normal wall thickness. A thread can be formed in the thickened portion. By means of the thickened portion, the thread length can be increased. Ideally, the extrusion is done without machining. As soon as the tip has penetrated the hole, it enters the sealing compound behind and substantially laterally extrudes the sealing compound. Fragments that can arise during the extrusion can be embedded in the sealing compound in the chamber. The screw shank adjacent to the tip has a conical outer thread, which presses out or forms an inner thread in the still flowable thickened portion. Ideally, the thread formation also does not require machining. Fragments that can arise during the thread formation can be embedded in the sealing compound in the chamber. The cylindrical portion of the outer thread adjacent to the conical thread engages with the newly formed inner thread and pulls the screw head adjacent to the cylindrical thread in the direction of the profile. Here, a clamping part located between the screw head and the thread can press on the profile. The hot tip and the also heated conical portion of the thread heat the sealing compound during the penetration. The friction between the entire screw and the sealing compound further increases the heating of the sealing compound. The liquid sealing compound is locally limited and wets the hot screw. The lateral displacement of the liquid sealing compound is impeded by the adjacent cold sealing compound and a high pressure arises in the liquid sealing compound. Due to the high pressure, the liquid sealing compound is also pressed into the gap between the inner thread of the profile and the outer thread of the screw, thereby permanently sealing the thread connection.

[0024] The manufacture of the hole can take place directly before the dosing of the sealing compound. The hole can be a drilled hole, a punched hole or a cut hole. The hole can be punched very precisely using a rotary drill. In addition, the hole can also be punched using a punching tool, in particular without an anvil. By means of the punching, the hole can be punched very quickly. The punching waste and the fragments produced when producing the hole can fall inside the chamber and be enclosed in the chamber. The hole can also be cut in the profile. For example, the hole can be produced by means of water jet cutting or laser cutting.

[0025] The hole can be made with a diameter that is much smaller than the screw. If the diameter of the screw is larger than the diameter of the hole, the screw can press material laterally relative to the hole, thereby forming a thickening of the wall around the hole. Due to the thickening, the thread can be longer than the wall. The smaller the hole, the more material the screw can press. For example, the hole can have a diameter between one and two millimeters. In particular, the hole can have a diameter of 1.5 millimeters. The diameter of the hole can be proportional to the diameter of the screw.

[0026] The existing screw hole of the clamping part placed on the profile can be detected. The hole can be made in the screw hole. The screw hole can be a through hole of the clamping part. The diameter of the screw hole can be larger than the screw. The diameter of the screw hole can be smaller than the head of the screw. For example, the screw hole can be optically detected by a camera. Then, a hole making device for making the hole can be aligned with the screw hole. In particular, the hole making device can be aligned concentrically with the screw hole, so that the hole is made in the center of the screw hole. For example, the hole making device can be designed to punch, drill, punch or cut a hole. Then, an application nozzle can be placed on the hole and a sealant is dosed through the hole into the cavity. After dosing, a screwing device can place a screw on the hole and screw it in. These devices can be combined in particular in one multifunctional robot head. For example, the robot head can have a carousel with different devices.

[0027] A butyl material can be dosed as a sealant into the cavity. Butyl or butyl material has a lasting elasticity and a good adhesion to metal, in particular at elevated temperatures. The butyl material can be easily dosed from a nozzle. To this end, the butyl material can be heated, for example to a temperature between 130°C and 150°C. When heated, the butyl material is pasty and plastically deformable. In the cavity, the butyl material can cool down again and harden into a state of lasting elasticity. The butyl material is reusable.

[0028] The method can be implemented, for example, in software or hardware or in a hybrid of software and hardware, for example in a control unit.

[0029] The solution presented here also implements a control device designed to perform, control or implement the steps of a variant of the method presented here in a corresponding device.

[0030] The control device can be an electrical device having at least one computing unit for processing signals or data, at least one memory unit for storing signals or data, and at least one interface and / or communication interface for reading in or outputting data embedded in a communication protocol. The computing unit can be, for example, a signal processor, a so-called system ASIC or a microcontroller, which is used to process sensor signals and output data signals from the sensor signals. The memory unit can be, for example, a flash memory, an EPROM or a magnetic memory unit. The interface can be designed as a sensor interface for reading in sensor signals from a sensor and / or as an actuator interface for outputting data signals and / or control signals to an actuator. The communication interface can be designed to read in or output data in a wireless and / or wired manner. The interfaces can also be software modules, for example, which exist together with other software modules on a microcontroller.

[0031] It is likewise advantageous to have a computer program product or computer program with program code, which can be stored on a machine-readable carrier or storage medium, such as a semiconductor memory, a hard disk memory or an optical memory, and serves to execute, implement and / or control the steps of the method according to one of the above embodiments, in particular in the case of execution of the program product or program on a computer or device. BRIEF DESCRIPTION OF DRAWINGS

[0032] One advantageous embodiment of the application will be explained below with reference to the drawings. In which:

[0033] Figure 1 A dosing of a sealant according to one embodiment of the application is shown.

[0034] The figures are merely schematic and serve only to explain the application. Identical or similar actions are provided with the same reference signs throughout. DETAILED DESCRIPTION

[0035] Figure 1 A dosing of a sealant according to one embodiment is shown. According to one embodiment, the dosing is shown in a cross-sectional view of a fluid-tight threaded connection 100. At the threaded connection 100, a screw 102 with an external thread is screwed into an internal thread of a profile 106. The profile 106 is a frame profile of a battery box of an electric vehicle. The screw 102 presses a clamping part 110 against the profile 106. The clamping part 110 can be, for example, a lid of the battery box.

[0036] The profile 106 is an extruded or drawn profile made of an aluminum or steel material. The profile 106 has a substantially constant cross section along its main extension direction. The profile 106 can also have bends within regions of its cross section, for example.

[0037] The profile 106 has a chamber 112 which extends along the entire length of the profile 106. At least one wall 114 of the chamber 112 is an outer wall of the profile 106. At one location of the threaded connection 100, the profile 106 has a hole 115. During dosing, a sealant 116 is dosed into the chamber 112 through the hole 115. For this purpose, an application nozzle 117 is placed at the hole, through which the sealant 116 is pressed into the chamber 112.

[0038] In one embodiment, the chamber 112 is completely filled.

[0039] In one embodiment, the chamber 112 is only filled in the area of the threaded connection 100, while remaining empty between adjacent threaded connections 100.

[0040] After dosing, the screw 102 is screwed into the chamber 112 through the hole 115. An internal thread is formed at the edge of the hole 115. The screw 102 is screwed into the sealant 116. The sealant 116 seals the threaded connection 100 in a fluid-tight manner.

[0041] When the screw 102 is screwed into the sealant 116, the sealant 116 is heated at least by the friction between the sealant 116 and the screw 102 and at least partially liquefied. In the liquid state, the sealant 116 wets the screw 102 and at least partially penetrates into the thread flight between the internal thread and the screw 102. The sealant 116 adheres to the surfaces of the screw 102 and the internal thread, thus sealing the thread flight.

[0042] The sealant 116 located behind the wall 114 can permanently bind debris that can be generated during screwing.

[0043] When the screw 102 is screwed into the hole 115, the friction between the screw 102 and the wall 114 heats the screw 102 and the wall 114. The heated wall 114 softens and is able to extrude the metallic material of the wall 114 laterally. In this case, an annular thickening is formed in the wall. The screw 102 forms an internal thread on the inside of the thickening. Then, the heated screw 102 penetrates into the sealant 116, which has been partially heated by the heated wall 114. This causes the sealant 116 to become a fluid flow state and particularly well wet the screw 102 and the internal thread. Debris is particularly well bound by the fluid flow state of the sealant 116.

[0044] In one embodiment, the profile 106 with the empty chamber 112 is cut to the desired length of the battery box and the sealant 116 is dosed into the chamber 112 through at least one hole 115 before the threaded connection 100 is made.

[0045] In one embodiment, the butyl material is dosed into the chamber 112 as a sealant 116. The butyl material is dosed at an elevated temperature. Due to the elevated temperature, the butyl material is at least pasty or mushy, can plastically fill the cross section of the chamber. Furthermore, due to the elevated temperature, the butyl material has a good adhesion to the walls of the chamber 112. When cooled to ambient temperature, the butyl material remains permanently elastic, but can no longer be plastically deformed. By heating during screwing in of the screw 102, the butyl material is made plastically deformable again and adheres well to the screw 102.

[0046] In one embodiment, the screw hole 120 of the clamping part 110 is detected, for example, optically, and the punching device is aligned with the screw hole 120. Using the punching device, a hole 115 is then punched in the wall 114. The punching device can, for example, drill or punch the hole 115. The hole 115 can also be cut with a laser or a water jet. The punching device is then removed and the application nozzle 117 is placed in the hole 115. Using the application nozzle 117, the sealant 116 is dosed through the hole 115 into the chamber 112. After the chamber 112 has been filled with the sealant 116 at least in the local area of the hole 115, the application nozzle 117 is removed and the screw 102 is placed into the hole 115 using the screwing device. The screwing device then screws the screw 102 through the hole 115 into the sealant 116.

[0047] In other words, a way of sealing a direct thread connection on a profile is proposed, which is filled through a hole on the cross line of the direct thread connection.

[0048] In the case of a direct thread connection, the tightness of the thread formed by the direct thread connection cannot be guaranteed. However, in the case of a battery system, precisely this function of tightness is important, even in terms of safety. The existing screw system, i.e. the screw and the profile in which the thread connection is made, and the screw technology associated with the process, cannot provide one hundred percent safety in terms of tightness.

[0049] The solution presented here ensures that the desired sealing takes place in the thread formed by the direct thread connection.

[0050] By filling the sealing agent in at least one chamber of the screw profile (Schraubprofils), the tightness of the threaded connection can be ensured even under operational loads. The filling is carried out through a guide hole directly below the screw, wherein a semi-direct threaded connection (SEMI-Direktverschraubung) is created when the screw is screwed in. The diameter of the guide hole is usually 1 to 2 mm, depending on the size of the screw. A fine application nozzle is used to fill the sealing agent. With butyl sealing agent as an example, the application can be realized taking into account the higher pressure and application time than in the case of large diameters. In order to realize an efficient cycle time, the drilling / milling tool can be connected to the same robot that is used for screwing, for example through a carousel solution. In this way, the rhythm of "drill-fill-screw" can be cyclically optimized.

[0051] By the sealing agent provided for this purpose in the chamber in which the threaded connection later takes place, it is ensured that the newly formed thread is automatically sealed during the threaded connection. Immersion of the screw in the sealing agent prevents water from penetrating the thread formed by the direct threaded connection.

[0052] If butyl is used as sealing agent, the heat generated by the friction during thread formation simultaneously softens the surrounding butyl compound and adheres to the screw. The adhesion of the butyl increases with increasing temperature. This also applies to other sealing agents.

[0053] Thus, the work of spraying, for example, wax or other sealing sprays on the surface can be omitted. With the direct threaded connection into the sealing agent presented here, a high-quality result can be achieved. The effort involved is very low. The process is very stable and achieves good reproducibility.

[0054] The solution presented here can be particularly suitable for battery systems, but can also be used in other fields. The high process reliability, as well as in standard industrialization, can achieve very good feasibility and functional assurance. The direct threaded connection into the chamber filled with sealing agent is a solution that does not affect the tolerances, saves space, is dirt-free and is independent of the screw type. By fixing and binding any swarf that can be generated by self-tapping and slotted screws during drilling and thread formation, a high technical cleanliness (TECSA) can be achieved.

[0055] Since the devices and methods described in detail above are embodiments, the skilled person can modify them in a very large number of ways, in a customary manner, without leaving the scope of the invention. In particular, the mechanical arrangements and the proportions between the individual elements are only exemplary.

[0056] Reference signs

[0057] 100 threaded connection

[0058] 102 screw

[0059] 106 profile

[0060] 110 clamping member

[0061] 112 chamber

[0062] 114 wall

[0063] 115 aperture

[0064] 116 sealant

[0065] 117 application nozzle

[0066] 120 screw hole

Claims

1. A method of producing a fluid-tight threaded connection (100) on a profile (106), wherein, A sealant (116) is dosed into a chamber (112) behind a wall (114) of the profile (106) through a hole (115) in the wall (114) and a screw (102) is screwed into the chamber (112) through the hole (115), wherein the screw (102) is screwed into the sealant (116) during the screwing in and, here, the sealant (116) is partially pressed by the screw (102) during the screwing in and the pressed sealant (116) is placed around the screw (102) and the hole (115), so that the screw connection (100) is sealed by the sealant (116).

2. The method of claim 1, wherein, The chamber (112) is completely filled with the sealant (116) during the dosing.

3. The method of claim 1, wherein, The chamber (112) is partially filled during the dosing in the area of the hole (115).

4. The method according to any of the preceding claims, wherein, The screw (102) presses the material of the wall (114) to the side of the hole (115) during the screwing in and forms a thread in the pressed material.

5. The method according to any one of the preceding claims, wherein, The hole (115) is formed before the dosing of the sealant (116).

6. The method of claim 5, wherein, The hole (115) is much smaller in diameter than the screw (102).

7. The method of claim 5 or 6, wherein, An existing screw hole (120) of a clamping part (110) placed on the profile (106) is detected and the hole (115) is made in the screw hole (120).

8. The method of any of the preceding claims, wherein, A butyl material is dosed as the sealant (116) into the chamber (112).

9. An apparatus for producing a fluid-tight threaded connection (100) on a profile (106), wherein The device is designed for performing, implementing and / or controlling the method according to any of the preceding claims in a corresponding apparatus.

10. A computer program product designed to instruct a processor to perform, implement and / or control the method according to any of claims 1 to 8 when executing the computer program product.

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