Method for attaching a sleeve to a cable loom, casting mould, set and arrangement of sleeve and cable loom

Abstract

The invention relates to a method for attaching a sleeve (2), which has a sealing body (12), to a cable loom (4), which extends in a longitudinal direction (L), wherein a first shell section (8) and a second shell section (10) are joined around the cable loom (4) to form a casting mould (G) and thereby form a cavity (14) through which the cable loom (4) is guided, wherein the casting mould (G) has an inlet opening (16) through which a sealing material is filled into the cavity (14), said sealing material forming a sealing body (12), wherein the first shell section (8) has at least one first rib (18) and the second shell section (10) has at least one second rib (20), wherein the first rib (18) and the second rib (20) each project into the cavity (14), are arranged offset to one another in relation to the longitudinal direction (L) and rest against the cable loom (4) so that, when the sealing material is filled into the cavity (14), a spreading of the sealing material in the longitudinal direction (L) is limited. The invention also relates to a corresponding casting mould (G) and to an arrangement consisting of a sleeve (2) and a cable loom (4).

Description

[0001] Description

[0002] Method for attaching a grommet to a cable harness, mold, set and assembly of grommet and cable harness

[0003] The invention relates to a method for attaching a grommet to a cable harness, a casting mold therefor and an arrangement comprising a grommet and a cable harness.

[0004] Grommets are generally used to seal a cable loom in wall penetrations. This means that the grommet is inserted into a hole in a wall together with a cable loom and seals the cable loom against the wall, preventing moisture from penetrating through the hole from one side of the wall to the other. Grommets are used specifically in the automotive sector, for example, in wall penetrations from a wet room to a dry room. A key aspect here is often ensuring a reliable longitudinal seal.

[0005] Grommets are typically manufactured through a casting process, in which the cable harness is surrounded by a casting material using a mold to form a grommet body. A frequently used material for this purpose is polyurethane (PUR). This is very fluid during processing, so sealing the mold is necessary during casting. A longitudinal seal is particularly desirable during the casting process.

[0006] DE 10 2015 220 318 A1 discloses a grommet with a hard outer shell consisting of two shell halves, which are filled with a casting material to form a grommet body. The outer shell forms a permanent casting mold, which is part of the grommet. Additional sealing elements are provided for sealing during the casting process. These are applied to the outer circumference of the cable harness, for example, as a sealing strip, sealing tape, or sealing compound. For this purpose, they are inserted into the shell halves, for example, and overlap each other when joined together.

[0007] Various grommets are also described in EP 3 617 575 A1, US 6 010 134 A, US 5 545 854 A, and DE 10 2022 000 941 A1. Reference is also made to the unpublished German patent application No. 10 2023 201 120.

[0008] Based on this, the invention is based on the object of ensuring the most reliable and secure sealing of a cable harness with the least possible installation effort within a wall penetration. To this end, an improved method for attaching a grommet to a cable harness and an improved arrangement of the grommet and cable harness are to be provided. Furthermore, a casting mold and a set of casting mold and molding tool used in such a method are to be provided.

[0009] The object is achieved according to the invention by a method for attaching a grommet, which has a sealing body, to a wiring harness which extends in a longitudinal direction, wherein a first shell part and a second shell part are assembled around the wiring harness to form a casting mold (method step: assembly) and thereby form a cavity through which the wiring harness is passed, wherein the casting mold has an inlet opening through which a sealing material is filled, in particular poured or injected, into the cavity (method step: filling), which sealing material forms the sealing body, wherein the first shell part has at least one first rib and the second shell part has at least one second rib, wherein the first rib and the second rib each protrude into the cavity, are arranged offset from one another with respect to the longitudinal direction and bear against the wiring harness,To limit the sealing material's longitudinal expansion when filling the cavity. The sealing material is then preferably cured (process step:

[0010] Curing).

[0011] In a first advantageous variant, the grommet is formed from the first switching part, the second shell part, and the sealing body. The two shell parts therefore remain on the sealing body as parts of the grommet after the process and in the finished state.

[0012] In a second advantageous variant, the first shell part and the second shell part each constitute one mold half of a molding tool. The grommet is then formed, in particular, solely from the sealing body; however, the first shell part and the second shell part are not part of the grommet. The two shell parts are, in particular, reusable, i.e., the same two shell parts are used to attach several similar grommets to a respective cable harness.

[0013] The two shell parts are therefore either disposable parts, which are used only once in the process and then remain as part of the grommet on the cable harness, or reusable parts, which are used as a mold to produce multiple grommets. Without limiting the generality, the first variant will be initially assumed below, and the second variant will be briefly explained in more detail below. The statements regarding the first variant also apply mutatis mutandis to the second variant, and vice versa.

[0014] The object is further achieved according to the invention by a casting mold for a method as described above.

[0015] The object is further achieved according to the invention by an arrangement comprising a grommet and a wiring harness, in particular produced according to a method according to the first variant as described above, wherein the grommet is formed from a first shell part, a second shell part and a sealing body, wherein the first shell part and the second shell part are assembled around the wiring harness, in particular to form a casting mold, and in doing so form a cavity through which the wiring harness is passed, wherein a sealing material which forms the sealing body is filled into the cavity, wherein the first shell part has at least one first rib and the second shell part has at least one second rib, wherein the first rib and the second rib each protrude into the cavity, are arranged offset from one another with respect to the longitudinal direction and bear against the wiring harness.

[0016] The object is also achieved in particular by a grommet (ie combination of casting mold and sealing body or sealing body without casting mold) as described above and below.

[0017] Advantageous embodiments, further developments, and variants are the subject of the dependent claims. The statements relating to the method also apply mutatis mutandis to the casting mold, the nozzle, and the arrangement, and vice versa.

[0018] A key idea of ​​the invention is, in particular, to prevent sealing material from escaping at undesired locations through the specially designed casting mold. When the sealing material is poured in, it spreads within the casting mold, specifically along the wiring harness in the direction of the wiring openings in the casting mold for the wiring harness. To prevent the sealing material from escaping along the wiring harness and out of these wiring openings, the two shell parts have a special inner contour on the inside (on an inner side of the wall), namely the ribs arranged offset from one another. The first and second ribs are not opposite one another; in fact, there is no rib arranged on the inside of the other shell part opposite a respective rib.The staggered arrangement forces the cable harness into a winding or meandering path (course) and, in particular, ensures that the casting mold fits as tightly as possible against the cable harness so that the sealing material cannot flow past during subsequent filling. The cable harness is pressed against the other shell part, particularly on the inside, by a respective rib; this part in particular does not have a special or complementary inner wall contour there. The ribs also create a so-called labyrinth seal, i.e. the path that the sealing material has to take from the cavity to exit the casting mold is enlarged, especially compared to a design without a labyrinth seal. Overall, this achieves a particularly good longitudinal seal, especially during attachment of the grommet to the cable harness.Since the mold remains attached to the cable harness after installation, a particularly good longitudinal seal is achieved even in the finished and assembled state, e.g., in a wall. The grommet presented here also meets standard IPC sealing requirements. The method according to the invention is also very well suited for automated production, e.g., cable harness production.

[0019] The invention is particularly advantageous for cable harnesses with a (maximum) diameter of up to 14 mm. Leakage tests (watertightness) on cable harnesses with diameters of up to 10 mm revealed no leakage during testing. For larger diameters, the test concept from application WO 2024 / 165320 A1 is particularly recommended; it was successfully used for a diameter of 40 mm.

[0020] In the process, the grommet is preferably manufactured by combining the two shell parts (casting mold) with the sealing material (first variant). The casting mold then remains on the cable harness as part of the grommet after the sealing body has been formed.

[0021] The cable harness contains one or more lines, in particular electrical lines (e.g. cables, Adem), alternatively or additionally media lines (e.g. hoses).

[0022] The casting mold generally extends in a longitudinal direction and along a longitudinal axis. The longitudinal direction is also referred to as the z-direction. Perpendicular to the z-direction are an x-direction and a y-direction, which are also perpendicular to each other. The casting mold is generally tubular in shape, with a wall surrounding the cavity. The casting mold also has two ends, each with a line opening through which the line bundle enters and exits the cavity. The separate, previously mentioned inlet opening for the sealing material is particularly formed in the wall, so that the sealing material is filled into the cavity in a radial direction during filling. The inlet opening is formed either in just one of the shell parts or partially in both shell parts, e.g. half in each case.

[0023] The casting mold has, in particular, a first end section with one of the line openings, and a second end section with the other line opening. The casting mold also has a central section which is arranged between the two end sections and connects them. The two ribs lie, in particular, on one of the two end sections and not on the central section. Both end sections are expediently each formed with a first rib and a second rib which are offset from one another in the longitudinal direction. The first shell part then has at least two first ribs, and the second shell part has at least two second ribs. The ribs are each located, in particular, completely within the cavity. The ribs each lie against the line strand, but not against one another. Due to the offset arrangement, one of the ribs is closer to one line opening than the other rib.

[0024] Preferably, each rib is C-shaped. This ensures particularly good contact with the cable harness. Preferably, each rib extends no more than halfway around the cable harness. This design is particularly easy to assemble, since none of the ribs protrudes into the other shell part. The ribs are, in particular, of identical design.

[0025] In the cavity, the sealing material forms in particular an inner seal as part of the sealing body. The inner seal lies entirely within the casting mold, in particular only or at least predominantly in the central section. Expediently, an outer seal is also formed as part of the sealing body from the same sealing material as part of the process. In a suitable embodiment, the casting mold for this purpose has at least one outlet opening through which (during filling) a portion of the sealing material exits the casting mold from the cavity. An outer seal is then formed from this portion of the sealing material, which surrounds the outside of the casting mold. An important advantage of this is that the inner seal and the outer seal are made from the same sealing material and in the same process step. In addition, the circumferential outer seal holds the two shell parts together so that they cannot fall apart.The outer seal is preferably rotationally symmetrical to the longitudinal axis. The outer seal expediently has a circumferential groove into which the edge of a hole in a wall engages, through which the cable harness is passed by means of the grommet.

[0026] In a practical embodiment, the casting mold has several, e.g., four, outlet openings as described, which are preferably evenly distributed around the longitudinal axis, so that the sealing material exits the casting mold as evenly as possible, forming a particularly homogeneous outer seal. The outlet openings are expediently located at the same longitudinal position, even when viewed along the longitudinal axis. Each outlet opening is designed, for example, as a rectangular window in the wall.

[0027] The inlet opening and / or the outlet opening are located in particular on the central section of the casting mold.

[0028] A particularly preferred embodiment is one in which the outer seal and the inner seal are made in one piece, i.e., monolithically. The sealing body is thus a single, monolithic part, which in particular consists exclusively of the sealing material. The sealing body then has the inner seal and the outer seal, and optionally at least one connecting web (depending on the number of outlet openings) between these two, which web is located in the outlet opening. Due to the one-piece design, the sealing body and the shell parts are particularly firmly connected to one another.

[0029] In addition, maximum tightness of the nozzle as a whole is achieved.

[0030] The outer seal is suitably formed using a molding tool into which the two shell parts (assembled to form the casting mold) with the wiring harness are inserted. In the method, therefore, in addition to the casting mold, a further molding tool is used in which the casting mold with the wiring harness is held while the sealing material is being poured in. The molding tool in particular completely encloses the casting mold. The molding tool is, for example, composed of two mold halves. The molding tool, in particular the mold halves, is made of, for example, PP or aluminum. The molding tool suitably has a feed channel which is connected to the inlet opening and through which the sealing material is poured into the casting mold. Furthermore, the molding tool forms a molding space with an outer side of the casting mold, which defines a contour of the outer seal. The molding space is accordingly, in particular, annular and runs around the casting mold.The portion of the sealing material that exits the mold's outlet opening enters this mold cavity. The mold cavity is then filled with sealing material, forming the outer seal. This seal is then molded onto the shell parts.

[0031] The object is further achieved according to the invention by a set comprising a casting mold and a molding tool for a method as described above. The statements regarding the method, casting mold, and nozzle also apply mutatis mutandis to the set, and vice versa.

[0032] The molding tool is preferably coated with PTFE or made of PTFE. Especially in connection with the formation of the outer seal, a release agent for demolding the grommet with outer seal is then dispensed with. The PTFE is applied at least to those points on the molding tool that come into contact with the sealing material, i.e. to those points on the molding tool that form the mold space for forming the outer seal. In the first variant mentioned above, the two shell parts are formed separately from the molding tool and are inserted into it. After the grommet has been attached to the cable harness, the two shell parts are removed from the molding tool together with the sealing body and the cable harness. In contrast, in the second variant mentioned above, the two shell parts are in particular identical to the molding tool and form at least the two mold halves of the molding tool.

[0033] In a practical embodiment, the casting mold has a flange which forms a casting contour during the molding of the outer seal, i.e. a casting contour for the sealing material from which the outer seal is molded. The flange is arranged in particular on the central section and, viewed in the longitudinal direction, is preferably located between the inlet opening and the outlet opening. In the finished state, i.e. after the grommet has been attached to the cable harness, the outer seal in particular continues to bear against the flange. Viewed in the longitudinal direction, the outer seal therefore has a rear side which, in particular, bears against the flange over its entire surface. The flange thus serves in particular as an abutment when the assembly comprising the grommet and cable harness is inserted into a wall. This assembly is inserted into a hole in the wall with the outer seal at the front and pressed into the hole.In particular, the outer seal has a circumferential groove to accommodate the inner contour of the hole. The flange prevents the outer seal from bending during insertion. Since the flange is made of a harder material than the outer seal, it also serves as an assembly aid for an installer or robot, which can press the assembly on the flange into the hole.

[0034] The flange suitably has a circular or elliptical outer contour. The flange is preferably disc-shaped or plate-shaped, with each of the shell parts in particular comprising one half of the flange. The flange extends in particular perpendicular to the longitudinal direction, i.e. in the radial direction. The casting mold therefore fundamentally has two components, namely a tube through which the cable harness is guided and which defines the cavity, and additionally the flange, which is attached to the outside of the tube, in particular is molded onto it, and runs around the tube. The flange thus also runs around the cavity. The flange and the tube are in particular made in one piece, i.e. monolithically, and are made in particular from the same material.

[0035] The outer seal is / is advantageously designed with a tapered front. This facilitates the insertion of the grommet into a hole in a wall. For example, the outer seal is conically shaped at its front. The tapered front is achieved in particular by a corresponding design of the mold.

[0036] The concept of a labyrinth seal, i.e. an extension of the path for potentially escaping sealing material, is expediently also applied elsewhere in the casting mold. In particular, the two shell parts each have an end face which rests against one another after being assembled to form the casting mold. In particular, the end faces of the shell parts do not rest against the cable harness, but rather cover one another, in particular completely. In an advantageous embodiment, to create a labyrinth seal, the end face of one shell part has a groove and the end face of the other shell part has a tongue which is inserted into the groove when the two shell parts are assembled to form the casting mold. In the assembled state, the tongue of one shell part therefore sits in the groove of the other shell part, in particular in a form-fitting manner.This creates a longer path for the sealing material out of the cavity, as it is not just the wall thickness of the mold that has to be overcome, but a longer path around the tongue. At the same time, the precisely fitting design of the tongue and groove results in significantly better sealing than if the two shell parts were simply arranged end to end. The tongue and groove in particular create a tongue and groove connection between the shell parts. It is advisable to form tongues and grooves along the entire end surfaces of the two shell parts, where possible, with each shell part having both tongues and grooves or just one of the two. In terms of the tongues and grooves, the two shell parts are always designed to complement one another.

[0037] The two shell parts are / are assembled in particular along an imaginary parting plane. In particular, the end faces already mentioned also lie in this parting plane. The longitudinal axis also lies in the parting plane. Accordingly, the parting plane extends in the longitudinal direction and, for example, in the y-direction. In an advantageous embodiment, the casting mold has an elliptical outer contour (ellipse) with a minor semi-axis which lies in the parting plane. The major semi-axis of the outer contour then runs perpendicular to the parting plane. The outer contour is obtained in particular when viewed in cross-section perpendicular to the longitudinal axis. Such an outer contour means that the casting mold is wider perpendicular to the parting plane. The cable harness runs out of the parting plane due to the ribs, and the corresponding turns due to the winding or meandering path lie in a plane perpendicular to the parting plane.The ribs thus each stand with their ends on the parting plane. A respective belly of the ribs lies accordingly on the major semi-axis. This design allows the ribs to be made correspondingly solid and stable, while at the same time creating space for the winding or meandering path of the cable harness in the direction of the major semi-axis.

[0038] The sealing material is preferably a polyurethane (PUR or PU), in particular foamed polyurethane, or a hard polymer. The polyurethane used is very fluid during processing, i.e. during filling, so that sealing of the mold is necessary even during filling, especially a longitudinal seal. The mold presented here advantageously enables the use of a polyurethane as a sealing material. Additional sealing of the mold using a second sealing material is preferably dispensed with. Rather, the mold is already sufficiently tight due to the design of the two shell parts and their interaction with the cable harness. No additional seals or the like are attached to the cable harness either. This makes the solution described here particularly cost-effective, especially in comparison to previous solutions.

[0039] In a preferred embodiment, the casting mold has at least one and preferably a plurality of openings, in particular opposite one another, in the parting plane between the shell parts, which openings are filled with sealing material after the casting process. This at least one opening or at least one of the plurality of openings is, for example, a filling opening. Alternatively, it is not a filling opening but, for example, an outlet opening through which sealing material can penetrate from the interior of the casting mold and, in particular, escape into an external space outside the casting mold. The sealing material located in the openings and, in particular, also the sealing material that has escaped into the external space therefore preferably forms a monolithic sealing body with the sealing material, specifically with the second sealing material (if present), inside the casting mold.

[0040] The sealing material located in the openings has the particular advantage that this sealing material creates a longitudinal seal, i.e. a longitudinal seal in the area of ​​the parting plane. This seal is therefore oriented more or less perpendicular to the wall of the two shell parts and thus forms a barrier to a cavitation path or a capillary effect path, so that no water can penetrate the grommet lengthwise. This improves the longitudinal watertightness. In other words: in order to prevent the capillary effect caused by the labyrinth seal in the parting area between the two shell parts, the sealing material (e.g. PUR foam) also specifically emerges in the parting area to interrupt the capillary flow. The additional opening in the parting plane then creates a wall of sealing material perpendicular to the labyrinth and thereby breaks the cavitation path.

[0041] The two shell parts are preferably made of a material that is harder than the sealing material, in particular harder than the sealing material in its cured state, i.e. harder than the sealing body. The two shell parts are preferably made of a hard plastic (in particular at room temperature). “Hard” is understood in particular to mean “dimensionally stable at room temperature”. Suitable hard plastics are thermoplastics and thermosets. Apart from the sealing material, the grommet is therefore rigid or static overall, which is required for some applications, e.g. in the case of an end wall grommet where automated insertion into a wall by spreading out an elastic grommet is not an option. Suitable materials for the shell parts are in particular polyamide (PA), polypropylene (PP) and similar materials.

[0042] In the following, exemplary embodiments of the invention are explained in more detail with reference to a drawing. In each case, the following schematically show:

[0043] Fig. 1 shows an arrangement of a grommet and a cable harness, Fig. 2 shows a casting mold composed of two shell parts, Fig. 3 shows the casting mold from Fig. 2 in another view, Fig. 4 shows the casting mold from Fig. 2 in another view, Fig. 5 shows the grommet from Fig. 1 in a partial sectional view, Fig. 6 shows the casting mold from Fig. 2 in a sectional view along a longitudinal axis, Fig. 7 shows a first shell part of the casting mold from Fig. 2, Fig. 8 shows a second shell part of the casting mold from Fig. 2,

[0044] Fig. 9 the first shell part from Fig. 7 in a perspective view,

[0045] Fig. 10 the second shell part from Fig. 8 in a perspective view,

[0046] Fig. 11 shows a method for attaching a grommet to a cable harness,

[0047] Fig. 12 is an exploded view of the arrangement of Fig. 1 and a mold used in the method of Fig. 11.

[0048] 1 to 10 show different views of an exemplary embodiment of a grommet 2, partially with a wiring harness 4. In particular, Fig. 1 shows an arrangement of a grommet 2 and a wiring harness 4. Fig. 11 shows a method for attaching a grommet 2 to a wiring harness 4, and Fig. 12 shows a molding tool 6 used for this purpose. The wiring harness 4 extends in a longitudinal direction L. The grommet 2 is formed from a first shell part 8, a second shell part 10 and a sealing body 12, wherein the first shell part 8 and the second shell part 10 are assembled around the wiring harness 4 to form a casting mold G (method step S1: assembly) and in the process form a cavity 14 through which the wiring harness 4 is guided. The casting mold G has an inlet opening 16 through which a sealing material is filled into the cavity 14 (process step S2: filling), which forms the sealing body 12.The first shell part 8 has at least one first rib 18, and the second shell part 10 has at least one second rib 20. The first rib 18 and the second rib 20 each protrude into the cavity 14, are offset from one another with respect to the longitudinal direction L, and bear against the cable harness 4 in order to limit the expansion of the sealing material in the longitudinal direction L when the sealing material is poured into the cavity 14. The sealing material is then cured (process step S3: curing).

[0049] The casting mold G in combination with the sealing body 12 forms a first variant of the grommet 2, which is manufactured according to a first variant of the method, in which the shell parts 8, 10 remain on the sealing body 12 as part of the grommet. The sealing body 12 alone then represents a second variant of the grommet 2, which is manufactured according to a second variant of the method, in which the two shell parts 8, 10 form the mold 6, e.g., are firmly integrated into it and form its mold halves. The following assumes the first variant, but the explanations also apply analogously to the second variant.

[0050] The specially designed casting mold G prevents sealing material from escaping at undesired locations. When the sealing material is poured in, it spreads out within the casting mold G, specifically along the cable harness 4 in the direction of the cable openings 22 of the casting mold G for the cable harness 4. In order to prevent the sealing material from escaping along the cable harness 4 and out of these cable openings 22, the two shell parts 8, 10 have a special inner contour on the inside (on an inner side of the wall), namely the ribs 18, 20 arranged offset from one another. Due to the offset arrangement, the cable harness 4 is forced into a winding, here also meandering path P, which is illustrated in Fig. 6, which shows a cross-sectional view of the casting mold G perpendicular to the parting plane T and along the longitudinal axis A.Furthermore, it is ensured that the casting mold G rests as positively as possible on the cable harness 4 so that the sealing material cannot flow past during subsequent filling. The ribs 18, 20 also create a so-called labyrinth seal, i.e. a path that the sealing material must take from the cavity 14 to exit the casting mold G is enlarged, especially compared to a design without a labyrinth seal. Overall, this results in particularly good longitudinal sealing, especially during the attachment of the grommet 2 to the cable harness 4. Since the casting mold G remains on the cable harness 4 after attachment, a particularly good longitudinal seal is also achieved in the finished and assembled state, e.g. in a wall. The grommet 2 presented here also meets standard IPC sealing requirements.

[0051] Within the process, the grommet 2 is manufactured by combining the two shell parts 8, 10 (molding mold G) with the sealing material. After the sealing body 12 has been formed, the mold G remains on the wiring harness 4 as part of the grommet 2. The wiring harness 4 contains one or more wires, e.g., electrical wires such as cables or wires, or alternatively or additionally, media lines such as hoses.

[0052] The casting mold G extends generally in a longitudinal direction L and along a longitudinal axis A. The longitudinal direction L is also referred to as the z-direction. Perpendicular to the z-direction are an x-direction X and a y-direction Y, which are also perpendicular to each other. The casting mold G is in this case tubular in shape overall, with a wall that surrounds the cavity 14. The casting mold G also has two ends, each with a line opening 22 through which the line strand 4 enters and exits the cavity 14. The separate, previously mentioned inlet opening 16 for the sealing material is introduced into the wall so that the sealing material is filled into the cavity 14 in the radial direction (X, Y) during filling.

[0053] In the present case, the casting mold G has a first end section 24 with one of the line openings 22, and a second end section 24 with the other line opening 22. The casting mold G also has a central section 26 which is arranged between the two end sections 24 and connects them. The ribs 18, 20 lie on one of the two end sections 24 and not on the central section 26. In the exemplary embodiment shown, the two end sections 24 even each have several (specifically: four) first ribs 18 and several (specifically: four) second ribs 20, which are offset from one another in the longitudinal direction L. The ribs 18, 20 each lie completely within the cavity 14 and each lie against the line strand 4, but not against one another.

[0054] In the exemplary embodiment shown here, each rib 18, 20 is C-shaped and extends no more than halfway around the cable harness 4. None of the ribs 18, 20 protrudes into the other shell part 8, 10. Furthermore, the ribs 18, 20 are of similar design.

[0055] In the cavity 14, the sealing material forms an inner seal 28 as part of the sealing body 12. The inner seal 28 lies completely within the casting mold G and only or at least predominantly in the central section 26. In the present case, an outer seal 30 is also formed from the same sealing material as part of the sealing body 12 as part of the process. For this purpose, the casting mold G has at least one outlet opening 32 through which (during filling) a portion of the sealing material exits the casting mold G from the cavity 14. This is illustrated in Fig. 10 by arrows Q. The outer seal 30 is then formed from this portion of the sealing material and then surrounds the outside of the casting mold G, as can be seen in Figs. 1 and 5. The inner seal 28 and the outer seal 30 are made from the same sealing material and in the same process step.The circumferential outer seal 30 also holds the two shell parts 8, 10 together, preventing them from falling apart. The outer seal 30 is rotationally symmetrical to the longitudinal axis A. The outer seal 30 also has a circumferential groove 34, into which a border of a hole in a wall engages (not shown), through which the cable harness 4 is guided by means of the grommet 2.

[0056] In the embodiment shown here, the casting mold G has several, specifically four, outlet openings 32 as described, which are evenly distributed around the longitudinal axis A. The outlet openings 32 are also located at the same longitudinal position when viewed along the longitudinal axis A. Each outlet opening 30 is formed as a rectangular window in the wall of the casting mold G. The inlet opening 16 and the outlet openings 32 are located on the central section 26 of the casting mold G.

[0057] In this case, the outer seal 30 and the inner seal 28 are also manufactured in one piece, i.e., monolithically. The sealing body 12 is thus a single, monolithic part consisting exclusively of the sealing material. The sealing body 12 has the inner seal 28 and the outer seal 30, as well as, if appropriate, a connecting web between these two, which is located in the outlet opening 32. Due to the one-piece design, the sealing body 12 and the shell parts 8, 10 are firmly connected to one another. Furthermore, maximum tightness of the grommet 2 as a whole is achieved.

[0058] The outer seal 30 is formed in the present case with the mold 6, into which the two shell parts 8, 10 (assembled to form the casting mold G) with the cable harness 4 are inserted. Fig. 12 shows this in an exploded view. The casting mold G with the cable harness 4 is held in the mold 6 while the sealing material is being poured in. The mold 6 completely encloses the casting mold G. The mold 6 is composed, for example, of two mold halves, as shown. The mold 6 has a supply channel 36, which is connected to the inlet opening 16 and via which the sealing material is poured into the casting mold G. Furthermore, the mold 6 forms a mold space 38 with an outer side of the casting mold G, which mold space defines a contour of the outer seal 30. The mold space 38 is correspondingly annular and runs around the casting mold G.The portion of the sealing material that exits the outlet opening 32 of the casting mold G enters this mold cavity 38. The mold cavity 38 is then filled with sealing material, forming the outer seal 30. This seal is then molded onto the shell parts 8, 10.

[0059] The molding tool 6 is coated with PTFE or made of PTFE in the present case; to form the outer seal 30, a release agent for demolding the grommet 2 with the outer seal 30 is omitted. The PTFE is applied at least to those points of the molding tool 6 that come into contact with the sealing material, i.e., to those points of the molding tool 6 that form the molding space 38 for forming the outer seal 30.

[0060] The casting mold G shown here has a flange 40 which forms a casting contour when the outer seal 30 is formed. The flange 40 is arranged on the central section 26 and, viewed in the longitudinal direction L, lies between the inlet opening 16 and the outlet opening 32. In the finished state (Fig. 1), i.e. after the grommet 2 has been attached to the cable harness 4, the outer seal 30 continues to lie against the flange 40. Viewed along the longitudinal direction L, the outer seal 30 therefore has a rear side which lies completely against the flange 40. The flange 40 thus serves as an abutment when the assembly comprising the grommet 2 and cable harness 4 is inserted into a wall. This assembly is inserted into a hole in the wall with the outer seal 30 at the front and pressed into the hole. The outer seal 30 has a circumferential groove 34 to accommodate an inner contour of the hole. The flange 40 now prevents the outer seal 30 from bending during insertion.Since the flange 40 is made of a harder material than the outer seal 30, the flange 40 also serves as an assembly aid for a fitter or robot, which can press the arrangement on the flange 40 into the hole in the wall.

[0061] The flange 40 has a circular (alternatively elliptical)

[0062] outer contour and is disc- or plate-shaped. Each of the shell parts 8, 10 has one half of the flange 40. The flange 40 extends perpendicular to the longitudinal direction L, i.e. in the radial direction (X, Y). The casting mold G therefore basically has two components, namely a tube 42 through which the cable harness 4 is guided and which defines the cavity 14, and additionally the flange 40, which is formed on the outside of the tube 42 and runs around it. The flange 40 thus also runs around the cavity 14. The flange 40 and the tube 42 are in this case made in one piece, i.e. monolithically, and consist of the same material.

[0063] In the embodiment shown here, the outer seal 30 is / is formed with a tapered front side 44. This facilitates the insertion of the grommet 2 into a hole in a wall. In the present case, the outer seal 30 is conically shaped at its front side 44. The tapered front side 44 is achieved by a corresponding design of the molding tool 6.

[0064] The concept of a labyrinth seal, i.e. an extension of the path for potentially escaping sealing material, is also applied elsewhere in the casting mold G. In the exemplary embodiment shown here, the two shell parts 8, 10 each have an end face 46 which abuts one another after being assembled to form the casting mold G. The end faces are particularly clearly visible in Figs. 7 to 10. The end faces 46 of the shell parts 8, 10 do not abut the cable harness 4, but rather completely cover one another. To create a labyrinth seal, the end face 46 of one shell part 8 (or 10) has a groove 48, and the end face 46 of the other shell part 10 (or 8) has a spring 50, which is inserted into the groove 48 when the two shell parts 8, 10 are assembled to form the casting mold G. In the assembled state (Fig.1 ), the tongue 50 of one shell part 10 sits in a form-fitting manner in the groove 48 of the other shell part 8, whereby a path for the sealing material out of the cavity 14 is correspondingly extended. At the same time, a correspondingly precisely fitting design of the groove 48 and tongue 50 achieves a significantly better seal than with a simple butt-fitting arrangement of the two shell parts 8, 10. The groove 48 and the tongue 50 create a tongue-and-groove connection between the shell parts 8, 10. In the present case, corresponding grooves 48 and tongues 50 are formed along the entire end faces 46 of the two shell parts 8, 10, wherein a respective shell part 8, 10 can then have both grooves 48 and tongues 50 (not shown) or only one of the two (as shown here). With regard to the grooves 48 and tongues 50, the two shell parts 8, 10 are in any case designed to be complementary to one another.

[0065] The two shell parts 8, 10 are / are put together along an imaginary parting plane T and the already mentioned end faces 46 also lie in this parting plane T. The longitudinal axis A also lies in the parting plane T. Accordingly, the parting plane T extends in the longitudinal direction L and in this case also in the y-direction Y. In the embodiment shown here, the casting mold G has an elliptical outer contour 52 (ellipse) with a small semi-axis 54 which lies in the parting plane T. The large semi-axis 56 of the outer contour 52 then runs perpendicular to the parting plane T. The outer contour 52 results in a cross-section viewed perpendicular to the longitudinal axis A. Such an outer contour 52 has the consequence that the casting mold G is wider perpendicular to the parting plane T. The cable strand 4 runs out of the parting plane T due to the ribs 18, 20, the corresponding turns due to the winding, meandering path P lie in a plane perpendicular to the parting plane T (see Fig. 6).The ribs 18, 20 thus each stand with their ends on the parting plane T. A respective belly of the ribs 18, 20 lies accordingly on the major semi-axis 56. Due to this design, the ribs 18, 20 are designed to be correspondingly solid and stable, while at the same time space is created in the direction of the major semi-axis 56 for the winding, meandering path P of the cable strand 4.

[0066] The sealing material in this case is a polyurethane (PUR or PU). The polyurethane used is very fluid during processing, i.e. during filling, so that sealing of the casting mold G is necessary even during filling, specifically also a longitudinal seal. The casting mold G presented here enables the use of such a polyurethane as a sealing material. Additional sealing of the casting mold G by means of a second sealing material is dispensed with. The casting mold G is already sufficiently tight due to the design of the two shell parts 8, 10 and their interaction with the cable harness 4. No additional seals or the like are attached to the cable harness 4 either. The two shell parts 8, 10 in this case are made of a material which is harder than the sealing material, specifically harder than the sealing material in its cured state.In this case, the two shell parts 8, 10 are made of a plastic that is hard at room temperature. Thus, apart from the sealing material (sealing body 12), the grommet 2 is rigid or static overall.

[0067] List of reference symbols

[0068] 2 spouts

[0069] 4 cable harness

[0070] 6 mold tool

[0071] 8 first shell part

[0072] 10 second shell part

[0073] 12 sealing bodies

[0074] 14 Cavity

[0075] 16 Inlet opening

[0076] 18 first rib

[0077] 20 second rib

[0078] 22 Cable opening

[0079] 24 final section

[0080] 26 Middle section

[0081] 28 Internal seal

[0082] 30 External seal

[0083] 32 outlet opening

[0084] 34 um running groove

[0085] 36 supply channel

[0086] 38 molding room

[0087] 40 flange

[0088] 42 pipe

[0089] 44 Front

[0090] 46 frontal area

[0091] 48 grooves

[0092] 50 springs

[0093] 52 Outer contour

[0094] 54 minor semi-axis

[0095] 56 major semi-axis

[0096] A Longitudinal axis

[0097] G Casting mold

[0098] L Longitudinal direction P Path

[0099] Q Arrow (path of the sealing material)

[0100] 51 Assembly

[0101] 52 Filling S3 Curing

[0102] T parting line

[0103] X x-direction

[0104] Y y-direction

Claims

Claims 1. Method for attaching a grommet (2) which has a sealing body (12) to a wiring harness (4) which extends in a longitudinal direction (L), a. wherein a first shell part (8) and a second shell part (10) are assembled around the wiring harness (4) to form a casting mold (G) and in the process form a cavity (14) through which the wiring harness (4) is passed, b. wherein the casting mold (G) has an inlet opening (16) through which a sealing material which forms the sealing body (12) is poured into the cavity (14), c. wherein the first shell part (8) has at least one first rib (18) and the second shell part (10) has at least one second rib (20), d.wherein the first rib (18) and the second rib (20) each project into the cavity (14), are arranged offset from one another with respect to the longitudinal direction (L) and bear against the line strand (4) in order to limit the spreading of the sealing material in the longitudinal direction (L) when the sealing material is filled into the cavity (14).

2. Method according to claim 1, wherein the grommet (2) is formed from the first switching part (8), the second shell part (10) and the sealing body (12).

3. The method according to claim 1, wherein the first shell part (8) and the second shell part (10) are each a mold half of a molding tool (6), wherein the spout (2) is formed from the sealing body (12) and wherein the first shell part (8) and the second shell part (10) are not part of the spout (2).

4. Method according to one of claims 1 to 3, wherein a respective rib (18, 20) is C-shaped.

5. Method according to one of claims 1 to 4, wherein a respective rib (18, 20) runs around the cable strand (4) at most halfway.

6. Method according to one of claims 1 to 5, wherein the casting mold (G) has at least one outlet opening (32) through which a part of the sealing material exits the casting mold (G) again from the cavity (14), and wherein an outer seal (30) is formed from this part of the sealing material, which seal surrounds the outside of the casting mold (G).

7. The method according to claim 6, wherein the outer seal (30) is formed with a molding tool (6) into which the two shell parts (8, 10) with the cable harness (4) are inserted, wherein the molding tool (6) is preferably coated with PTFE or is made of PTFE.

8. The method according to claim 6 or 7, wherein the casting mold (G) has a flange (40) which forms a casting contour during the formation of the outer seal (30).

9. The method according to any one of claims 6 to 8, wherein the outer seal (30) is formed with a tapered front side (44).

10. Method according to one of claims 1 to 9, wherein the two switching parts (8, 10) each have an end face (46), wherein the end face (46) of one shell part (8) has a groove (48), wherein the end face (46) of the other shell part (10) has a spring (50) which is inserted into the groove (48) when the two shell parts (8, 10) are assembled to form the casting mold (G).

11. Method according to one of claims 1 to 10, wherein the two shell parts (8, 10) are assembled along an imaginary parting plane (T), wherein the casting mold (G) has an elliptical outer contour (52) with a small semi-axis (54) which lies in the parting plane (T).

12. Method according to one of claims 1 to 11, wherein the sealing material is a polyurethane or a hard polymer.

13. Method according to one of claims 1 to 12, wherein the two shell parts (8, 10) are made of a hard plastic.

14. Casting mold (G) for a method according to one of claims 1 to 13.

15. Set comprising a casting mold (G) and a molding tool (6) for a method according to claim 7.

16. An arrangement comprising a grommet (2) and a wiring harness (4), in particular manufactured according to a method according to one of claims 1 to 11, a. wherein the grommet (2) is formed from a first shell part (8), a second shell part (10) and a sealing body (12), b. wherein the first shell part (8) and the second shell part (10) are assembled around the wiring harness (4) and thereby form a cavity (14) through which the wiring harness (4) is guided, c. wherein a sealing material is filled into the cavity (12), which forms the sealing body (12), d. wherein the first shell part (8) has at least one first rib (18) and the second shell part (10) has at least one second rib (20), e. wherein the first rib (18) and the second rib (20) each protrude into the cavity (14), are arranged offset from one another with respect to the longitudinal direction (L) and bear against the cable harness (4).

Images