Hydraulic bearing with stop shell and manufacturing process for such hydraulic bearing stop shell

Abstract

A hydraulic bearing (2) is proposed, which has a central longitudinal axis (Z), comprising a core (4), a sleeve (6) surrounding the core (4), at least two hydraulic bearing stop shells (8) between the core (4) and the sleeve (6), a stop stop (10) for each hydraulic bearing stop shell (8), which is mounted on the hydraulic bearing stop shell (8) and arranged radially outside to the core (4), wherein each hydraulic bearing stop shell (8) comprises at least one opening (12) in the radial direction (R) which is bounded by a circumferential edge region (20), wherein the corresponding stop stop (10) is arranged such that it can project into this opening (12) when loaded in the radial direction (R), wherein the opening (12) is a opening produced by a separating process and / or the opening (12) has fiber ends of the fiber-reinforced plastic composite on the circumferential surface (24) machined by a separating process, and at least two chambers (14, 16),which are fillable or filled with a hydraulic fluid and are fluidically connected to each other via a channel, wherein each hydraulic bearing stop shell (8) is formed from a fiber-reinforced plastic composite, wherein each hydraulic bearing stop shell (8) is an injection-molded part or a flow-formed part.

Description

[0001] The invention relates to a hydraulic bearing with a stop shell according to claim 1 and a manufacturing method for such a hydraulic bearing stop shell according to claim 9.

[0002] Hydraulic suspension bearings with radial damping are well-known in practice. When the vehicle brakes, these bearings are sometimes subjected to high radial loads. To absorb these high loads, such suspension bearings can be equipped with end stops. These end stops can consist of a stopper that is elastically mounted in a housing of the suspension bearing. This housing can include a through-hole through which the stopper can move under high loads.

[0003] For example, DE 10 2008 058 239 B4 discloses a hydraulic suspension bearing with such stoppers in shells. DE 102017 119 933 A1 deals with the production of a fiber composite component by extrusion with an elastomer seal.

[0004] A well-known and cost-effective manufacturing method for such shells is plastic injection molding. However, plastic injection molding inevitably leads to a disadvantageous weld line at the opening. This weld line weakens the shell's structure, so that it can break under high loads.

[0005] Metal bowls milled from solid blocks to avoid the aforementioned weld seam are also known in practice. However, such metal bowls are heavy, very complex to manufacture, and also very expensive.

[0006] The object of the invention is therefore to create a hydraulic bearing with stop shells that are further developed with regard to the aforementioned disadvantages. Furthermore, a manufacturing method for such hydraulic bearing stop shells is to be proposed.

[0007] The main features of the invention are specified in claims 1 and 8. Embodiments are the subject of the dependent claims.

[0008] According to the invention, a hydraulic bearing is therefore proposed which has a central longitudinal axis, comprising a core, a sleeve surrounding the core, at least two hydraulic bearing stop shells between the core and the sleeve, a stop stop for each hydraulic bearing stop shell which is mounted on the hydraulic bearing stop shell and arranged radially outside to the core, wherein each hydraulic bearing stop shell comprises at least one opening in the radial direction which is limited by a circumferential edge region, wherein the corresponding stop stop is arranged in such a way as to be able to project into this opening when loaded in the radial direction, wherein the opening is an opening produced by a separating process and / or the opening on the circumferential surface processed by a separating process has fiber ends of the fiber-reinforced plastic composite, and at least two chambers,which are fillable or filled with a hydraulic fluid and are fluidically connected to each other via a channel, wherein each hydraulic bearing stop shell is formed from a fiber-reinforced plastic composite, wherein each hydraulic bearing stop shell is a flow-formed part.

[0009] The hydraulic bearing stop shell, as an injection-molded or flow-formed part, eliminates the disadvantageous weld line at the opening, since the component according to the invention allows for a shearing process to create the opening without damaging the half-shell. If an opening were produced by shearing or machining and crossed a weld line in the process, this would lead to inhomogeneity in the fracture pattern and / or fiber distribution and / or fiber orientation.

[0010] Surprisingly, it turned out that extrusion, a process not typically used for components the size of a hydraulic bearing stop shell, is particularly suitable for manufacturing highly stressed hydraulic bearing stop shells. This is especially true when extrusion thermoplastic semi-finished products. Such thermoplastic semi-finished products for extrusion processes have so far been on the order of one square meter in size. Components manufactured using extrusion, such as front ends for vehicles, are therefore usually of a similar size. To produce components the size of hydraulic bearing stop shells, which are only a few square centimeters in area, the large semi-finished products must either be cut into small plates before being placed in the press and then inserted into the individual cavity(ies).Alternatively, a large semi-finished product is placed in a large multi-cavity press mold, from which a very large number of components can then be molded in a single pressing operation. In the latter case, however, each individual component must then be precisely machined out of the outer circumference of the formed plate. In both cases, significant costs arise for mechanical parting operations, so components the size of a hydraulic bearing stop shell are typically injection molded.

[0011] The opening in each hydraulic bearing stop shell is a perforation created by a separating process and / or the opening exhibits fiber ends of the fiber-reinforced composite on its circumferential surface, which has also been machined by a separating process. The opening may be a cut-out opening. The opening has an inner circumferential surface. The circumferential surface may be formed by the circumferential edge region. Due to the separating manufacturing of the opening, open, sheared, or cut fiber ends may be present in the circumferential surface. However, this temporary disadvantage results in lower manufacturing costs, as it eliminates the need for a complex and expensive process for creating the opening.It is conceivable that the circumferential surface in the assembled state, in which the hydro bearing stop shell is installed in the hydro bearing, can simply be covered by the elastomer body vulcanized there, so that it is easy to prevent fiber ends present there from causing damage to the stop when immersed in the opening.

[0012] The separation process can be achieved, for example, by punching, breaking, fine blanking, and / or milling. The separation can result in a fracture surface or fracture edge within the opening. The fracture surface or fracture edge can be located on the inner circumferential surface of the opening. While punching and fine blanking are cost-effective, the advantage of milling lies in producing a clean opening and preventing fiber matrix adhesion failure at the fracture surface or the inner circumferential surface of the opening. Furthermore, milling results in a clean cut through the fibers, leading to less fiber pullout in the cut surface compared to creating the fracture surface by punching, breaking, or fine blanking. The opening can be a milled opening, or the inner circumferential surface of the opening can be a milled inner circumferential surface.If, after punching, the fiber is no longer completely embedded in the matrix, but rather separations between fiber and matrix have occurred at the fracture surface, the fluid in the hydrobearing can more easily penetrate the polymer matrix via capillary action. This would promote polymer degradation through hydrolysis (in conjunction with the glycol, especially when using a glycol-water mixture); the component could fail prematurely. Cutting out the perforation has the advantage of easily verifying that the perforation does not contain or cross a weld line.

[0013] The injection-molded part may have or be manufactured with a central or umbrella gate. The central or umbrella gate may be located within the opening. Both manufacturing processes are evident in the hydraulic bearing stop shells. In both variants, fiber-reinforced polymer flows from the area of ​​the opening into the remaining component volume. In both processes, the opening can be mechanically created by cutting out the part after plastic forming and subsequent solidification. Consequently, a burr or circumferential structures are visible around the opening, indicating mechanical post-processing, such as breaking or milling. This effectively avoids the disadvantages of weld line formation associated with injection molding using pinpoint gates.

[0014] According to further training, the average preferred direction of the fibers can deviate by a maximum of 45° from the circumferential direction along the entire perimeter of the opening. The perimeter can be defined as the component volume extending up to one millimeter into the component from the surface of the opening. Alternatively or additionally, fibers in the perimeter can follow the circumferential course of the opening, thereby forming a fiber frame.

[0015] The hydraulic bearing can be in the form of a bushing. The hydraulic bearing stop shells can each be half-shells. The averaged preferred direction can affect all fibers in the circumferential edge region. The use of a fiber-reinforced plastic composite for the hydraulic bearing stop shell serves to avoid detrimental weld lines. Each hydraulic bearing stop shell can be weld line-free. The use of a fiber-reinforced plastic composite for the hydraulic bearing stop shell also serves to reduce weight and costs compared to conventional hydraulic bearing stop shells made of metal. Each hydraulic bearing stop shell can consist entirely of the fiber-reinforced plastic composite. Each hydraulic bearing stop shell can be formed in one piece from the fiber-reinforced plastic composite. Each hydraulic bearing stop shell can have a wall thickness in the range of 3 mm to 5 mm. The wall thickness can correspond to the diameter of a hypothetical largest sphere that would fit inside the hydraulic bearing stop shell.The wall thickness can differ from the thickness of the circumferential edge area.

[0016] The fibers in the circumferential edge region exhibit a deliberate direction or orientation. The fibers in this region can follow the circumferential path of the opening. Through their orientation, the fibers in this region can form a fiber frame that surrounds and / or reinforces the opening, preferably directly. It has been observed that a fiber orientation following the circumferential direction of the opening leads to a significant increase in strength in the area of ​​the opening. This allows the hydraulic bearing stop shells to withstand high loads. The orientation of the fibers in the circumferential edge region can result in a fiber concentration there that is higher than in other areas of the hydraulic bearing stop shell, which also contributes to the increased strength.

[0017] The "average preferred direction of the fibers" can apply to all fibers in the circumferential region. The preferred direction of each fiber in the circumferential region can refer to an adjacent point on the circumferential surface of the opening.

[0018] Each fiber can be symbolized mathematically as a vector. Each vector can be adjacent to a corresponding point on the circumferential surface of the opening. The circumferential direction can pass through this point on the circumferential surface. This point can have a tangent. The tangent can characterize the course of the circumferential direction at this point. A corresponding angle can be drawn between the vector and the tangent. The angle, given in degrees (°), can refer to an angle in a central surface of the corresponding hydraulic bearing stop shell. The central surface can extend along the planar extent of the hydraulic bearing stop shell.

[0019] The deviation of the average preferred fiber direction by a maximum of 45° in the circumferential edge region also serves to avoid weld lines, which typically exhibit a preferred fiber orientation perpendicular to the circumferential direction of a perforation. If the preferred fiber direction deviates from the circumferential direction by a maximum of 45° in the circumferential edge region, the fibers are predominantly oriented circumferentially. This results in a particularly high load-bearing capacity at the edge and prevents significant stress concentrations due to local fiber inhomogeneities, such as weld lines. It is conceivable that the average preferred fiber direction deviates from the circumferential direction by a maximum of 30°, preferably by a maximum of 15°.

[0020] The hydraulic bearing can comprise two stopper means. Each stopper means can comprise a stop stop, a hydraulic bearing stop shell, and an elastomeric body connecting the stop stop and the stop shell, preferably consisting of the following, wherein the stop stop can, under load, plunge into the opening and / or pass through the opening in the direction of a load path.

[0021] According to another conceivable embodiment, the hydraulic bearing stop shells can also be manufactured using long glass fiber injection molding. This can be done with a sprue or central gate. However, during the plasticizing of the plastic in the injection unit and the subsequent injection process, the fiber length decreases, so that fiber lengths of at most 8 mm can be achieved in the component; average fiber lengths are generally even less than 5 mm.

[0022] It is conceivable that continuous fibers are at least 50 mm long and long-strand fibers have a length between 10 mm and 50 mm. These lengths could refer to the fiber-reinforced plastic composite before injection molding or compression molding.

[0023] The highest strength, stiffness, and impact resistance requirements for a hydraulic bearing stop shell can preferably be achieved by using long fibers to reinforce semi-finished products for extrusion. Fiber lengths of up to 50 mm are readily achievable and processable. In some cases, even continuous fiber-reinforced semi-finished products, such as GMT semi-finished products, can be used, although it is important to ensure that the plasticized semi-finished products still exhibit sufficiently good flow properties despite the long fibers. During the extrusion process, the plasticized semi-finished product can be pressed outwards from the perforation area, thereby establishing the preferred fiber orientation in the circumferential direction of the perforation, as required by the stress. This results in significant advantages in mechanical properties, which can compensate for or even outweigh the disadvantages of the higher costs associated with the cutting processes.

[0024] According to one possible design of the hydraulic bearing, the wall thickness of the hydraulic bearing stop shells and / or the thickness of the circumferential edge area can be formed by plastic material (thermoplastic or thermoset) displaced by an extrusion process. This results in a very impact-resistant circumferential edge area. Using the extrusion process, plastic material can be forced outwards from the area of ​​the opening into the circumferential edge area, where it aligns itself with the fibers in the circumferential direction of the opening without forming a weld line.

[0025] According to one possible design of the hydraulic bearing, the hydraulic bearing stop shells can each be a GMT extrusion part (GMT = glass mat reinforced thermoplastic), an extrusion part made of a thermoplastic semi-finished product with fiber bundles or individual fibers of up to 60 mm length, or an SMC extrusion part (SMC = Sheet Molding Compound).

[0026] According to one possible embodiment of the hydraulic bearing, the circumferential edge region can include alignment fibers. These alignment fibers can be pre-aligned, for example, by means of a fiber preform positioned according to the opening, so that the fiber orientation corresponds to the circumferential direction. Alternatively, alignment fibers can be subsequently oriented (for example, after insertion into a mold). The alignment fibers can thus have an orientation that differs from the initial orientation of the fibers when inserted into a mold. The initial orientation of the fibers can be modified to establish the average preferred fiber direction along the circumferential direction of the opening across the entire circumferential edge region, with a maximum deviation of 45°.The reorientation is visible in the hydro-bearing stop shell; for example, the fibers or alignment fibers in the circumferential edge area can form a fiber frame.

[0027] According to one possible embodiment of the hydraulic bearing, the hydraulic bearing stop shells can contain disordered fibers in certain areas. It is conceivable that a disordered fiber orientation exists outside the circumferential edge regions. This disordered fiber orientation can be present completely or at least partially outside the circumferential edge regions. This allows the hydraulic bearing half-shells to be manufactured from fiber semi-finished products with disordered fibers.

[0028] According to one possible design of the hydraulic bearing, the bearing stop shells can additionally incorporate ordered fibers in certain areas. It is conceivable that an ordered fiber orientation exists, at least partially, outside the circumferential edge regions. This allows the hydraulic bearing stop shells to be manufactured from a combination of fiber semi-finished products with unoriented fibers and fiber semi-finished products with oriented fibers (for example, fabrics and / or tapes). Fiber semi-finished products with oriented fibers can contribute additional fabric layers and serve as additional reinforcement.

[0029] According to one possible embodiment of the hydraulic bearing, the circumferential edge region can have a width, preferably a continuous width in the circumferential direction of the opening, of at most 1 mm. This width can be oriented transversely to the radial direction of the hydraulic bearing. Thus, a suitably wide circumferential edge region or fiber frame can be provided. The circumferential edge region can therefore extend from the opening to each side of the opening over a specified distance of at most 1 mm into the hydraulic bearing stop shells.

[0030] According to one possible embodiment of the hydraulic bearing, the opening can have a fracture surface or fracture edge. The fracture surface or fracture edge can be located on the inner circumferential surface of the opening. The fracture surface or fracture edge can extend over the entire height and / or the entire circumference of the inner circumferential surface. It is conceivable that the circumferential surface of the opening is formed by the fracture surface or fracture edge, preferably exclusively by it.

[0031] According to one possible design of the hydraulic bearing, the circumferential edge area can form the fracture surface or fracture edge.

[0032] According to one possible embodiment of the hydraulic bearing, the circumferential edge region can have a thickness in the range of 0.1 mm to 1 mm, preferably between 0.2 mm and 0.4 mm. This thickness can be parallel to the radial direction of the hydraulic bearing. The thickness of the circumferential edge region can correspond to the wall thickness of the hydraulic bearing stop shell and / or the thickness of the fracture surface or fracture edge. This ensures that, during the manufacturing of the hydraulic bearing stop shell, material is present and flowable in the area of ​​the subsequent perforation, which is thicker than known parting lines in the parting plane of an injection mold. This material can be removed by means of the parting process.

[0033] According to one possible embodiment of the hydraulic bearing, the fracture surface or fracture edge can have a thickness in the range of 0.1 mm to 1 mm, preferably between 0.2 mm and 0.4 mm. This thickness can be parallel to the radial direction of the hydraulic bearing. This ensures that, during the manufacturing of the hydraulic bearing stop shell, material is present and flowable in the area of ​​the subsequent perforation, which is thicker than known parting lines in the parting plane of an injection mold. The material present there can be removed by means of the parting process.

[0034] According to one design of the hydraulic bearing, each hydraulic bearing stop shell can be weld line-free. The hydraulic bearing stop shell, as an injection-molded or flow-formed part, enables the avoidance of the detrimental weld line.

[0035] According to one embodiment of the hydro bearing, the penetration on its inner circumferential surface can exhibit a uniform fiber fracture and / or fiber cut pattern across its entire circumference. The fiber fracture pattern can extend across the thickness of the fracture surface or fracture edge.

[0036] According to the invention, the hydraulic bearing stop shells are each manufactured from a fiber-reinforced plastic composite semi-finished product which, with respect to its volume, consists of at least 75%, preferably at least 85%, and more preferably entirely, of a plate-shaped and / or solid-shaped, long-glass-fiber-reinforced thermoplastic composite semi-finished product. An advantage of such high volume percentages is that the structural strength of the hydraulic bearing stop shells can be adjusted by the semi-finished product. Furthermore, the semi-finished product is advantageously pressable, for example, by flow forming.

[0037] According to one embodiment of the hydro bearing, the fibers of the circumferential edge region can be oriented in the circumferential direction of the opening. Preferably, more than 50% of the fibers of the circumferential edge region are oriented in the circumferential direction of the opening, and more preferably, more than 75%. This results in particularly high strength and stiffness and can serve to form a fiber frame that surrounds and / or reinforces the opening, preferably directly.

[0038] According to one embodiment of the hydraulic bearing, the average fiber length of the fibers in the hydraulic bearing stop shells can be greater than 5 mm, preferably greater than 10 mm, and more preferably greater than 40 mm. Such long fibers in the hydraulic bearing stop shells contribute to strength and stiffness, particularly in the circumferential edge region, even when a fiber frame is formed. This allows particularly high forces to be introduced into the fibers. Furthermore, while fiber breakage may occur at the fracture surface, fiber pullout from the matrix is ​​minimal or nonexistent. It is conceivable that the semi-finished product of the fiber-reinforced plastic composite contains predominantly or exclusively fiber lengths of 1 inch (25.4 mm), 0.5 inch (12.7 mm), or 2 inches (50.8 mm), or a mixture thereof.

[0039] According to one embodiment of the hydraulic bearing, the ratio of fiber length to fiber thickness of the fibers of the hydraulic bearing stop shells can be at least 500:1, preferably 50000:1. This ratio has been shown to be suitable for further strengthening the hydraulic bearing stop shells.

[0040] According to one embodiment of the hydraulic bearing, each hydraulic bearing stop shell can have a surface projection of less than 100 mm x 100 mm. It has been shown that components of this size can also be formed from a fiber-reinforced plastic composite with the fiber orientation described in the invention. This size also has the advantage that conventional tools can be used to simultaneously produce a large number of hydraulic bearing stop shells according to the invention using a single semi-finished product and in a single flow-forming cycle.

[0041] According to one embodiment of the hydraulic bearing, the hydraulic bearing stop shells can be designed without elastomer on their outer circumference and / or have a parting line or burr and bear against an elastomer coating of a support cage of the hydraulic bearing. The hydraulic bearing stop shell can have an outer circumferential trim with a rough surface, which is particularly well suited for fixation in the hydraulic bearing. This is because the hydraulic bearing stop shells can be arranged within a window of the support cage. This support cage, in turn, can be embedded in elastomer, preferably partially. The hydraulic bearing stop shells can thus bear against the outer circumference of the elastomer coating of the support cage, with the rough outer circumferential surface of the hydraulic bearing stop shell minimizing slippage of the support cage within its clamping position.Therefore, it is advantageous if the rough outer edge of the hydro-bearing stop shells according to the invention is at least partially in contact with the elastomer coating of the cage or can be arranged there.

[0042] According to the invention, a method for manufacturing a hydraulic bearing stop shell according to the disclosure is also proposed, comprising the following steps: - Providing a form, - Arranging a fiber-reinforced plastic composite semi-finished product in the mold, - Closing the mold and extrusion of the fiber-reinforced plastic composite semi-finished product.

[0043] The advantages already described above regarding the hydraulic bearing also apply analogously to the process described here. The mold can have at least one cavity, preferably several. Surprisingly, it has been found that the known extrusion process is suitable for forming even smaller components from a fiber-reinforced plastic composite with the aforementioned fiber orientation. Arranging the fiber-reinforced plastic composite semi-finished product results in an initial orientation of the fibers. The process can be an extrusion process. After compression molding and / or cooling and / or die-cutting, a hydraulic bearing stop shell can be created. The wall thickness of the hydraulic bearing stop shell and / or the thickness of the circumferential edge region can be entirely formed by the plastic displaced during compression molding.

[0044] According to one conceivable embodiment, the process can include the step of pre-assembling the fiber-reinforced plastic composite semi-finished product, wherein the pre-assembly step comprises the following sub-step: - Separation of fiber-reinforced plastic composite semi-finished product segments from a fiber-reinforced plastic composite semi-finished product.

[0045] In this case, the subsequent step of "arrangement in the mold" can be an "arrangement of several fiber-reinforced composite semi-finished product segments" in the mold. It is conceivable that the volume of each fiber-reinforced composite semi-finished product segment corresponds at least to the volume of the hydraulic bearing stop shell produced from it, preferably including the material to be removed from the intended opening.

[0046] According to one possible embodiment of the process, the mold can be a multi-cavity mold. A hydraulic bearing stop shell can be produced in each cavity.

[0047] According to one possible embodiment of the process, the separation of fiber-reinforced plastic composite semi-finished product segments from a fiber-reinforced plastic composite semi-finished product can be carried out by cutting.

[0048] According to one possible embodiment of the process, the segment(s) can be dimensioned and / or separated in such a way that they can be placed completely within the cavity(ies). Thus, the segment(s) do not protrude beyond the edge of the cavity(ies).

[0049] According to one possible embodiment of the process, the segment(s) can be smaller than 100 mm x 100 mm. The dimensions refer to the separated segment before it is "arranged in the mold".

[0050] According to one possible embodiment of the process, the segment(s) can have a thickness of at most 15 mm, preferably at most 8 mm. The dimensions refer to the separated segment before its arrangement in the mold.

[0051] According to one possible embodiment of the procedure, the step of “arranging in the mold” can be carried out in such a way that the segment(s) are completely placed in the cavity(ies).

[0052] According to one possible design, pre-assembly can include the following further sub-step: - Stacking of multiple fiber-reinforced plastic composite semi-finished product segments.

[0053] In this case, the subsequent step of "arranging in the mold" can be "arranging several stacks of fiber-reinforced composite semi-finished product segments" in the mold. Stacking creates a stack of several fiber-reinforced composite semi-finished product segments. It is conceivable that the volume of each stack of fiber-reinforced composite semi-finished product segments corresponds at least to the volume of the resulting hydraulic bearing stop shell, preferably including the material to be removed from the intended opening.

[0054] According to one possible embodiment of the process, the "arrangement in the mold" step can involve arranging a fiber-reinforced plastic composite semi-finished product that covers several cavities. Thus, no segments of the fiber-reinforced plastic semi-finished product are separated from the composite material. After the "extrusion of the fiber-reinforced plastic semi-finished product" step, the hydraulic bearing stop shells can then be released, milled, or broken out at their outer edge. This offers manufacturing advantages, as a large fiber-reinforced plastic semi-finished product is easier and faster to insert into the mold than many smaller segments.

[0055] According to one embodiment of the process, the mold closing step can include the substep of displacing fibers from the area where the perforation is intended into a circumferential edge or circumferential edge region that borders the perforation. During this process, the fibers can align themselves along the circumferential direction of the perforation. Thus, the initial orientation of the fibers can be changed during mold closing to create a subsequent orientation. The mold can include a punch that, during closing, can force plastic material from the area of ​​the (subsequent) perforation outwards into the circumferential edge region. During this process, the fibers can also rearrange themselves in the circumferential direction of the perforation (subsequent orientation) without forming a weld line.

[0056] According to one embodiment of the process, a plasticization step of the fiber-reinforced plastic composite semi-finished product can be performed before the displacement step, so that the fiber-reinforced plastic composite semi-finished product is deformable during the displacement step. Plasticization is understood to mean the transition from a solid to a deformable or flowable state, in order to facilitate or enable further processing. If such a fiber-reinforced plastic composite semi-finished product is plasticized before being placed in the mold and only then arranged in the mold, the fibers can be particularly well reoriented circumferentially by closing the mold. This allows for the formation of a particularly stable fiber frame.

[0057] According to one possible embodiment of the process, the fiber-reinforced plastic composite semi-finished product can be, or comprise, a thermoplastic matrix with bundles of long glass fibers and / or unoriented continuous fibers. It is particularly suitable for generating a stable fiber frame around the circumferential edge region.

[0058] According to one possible embodiment of the process, the fiber-reinforced plastic composite semi-finished product can be placed in the mold in such a way that fibers are arranged in, or protrude into, the area where the perforation is provided. This arrangement can result in the fibers in the circumferential edge region being those fibers that have been displaced from the area where the perforation is provided.

[0059] According to one possible embodiment of the process, the fiber-reinforced plastic composite semi-finished product can be free of a pre-cut hole in the area where the perforation is intended. This eliminates the need for corresponding hole production.

[0060] According to one embodiment of the process, after the compression molding and / or curing steps, a perforation can be removed using a separating process. Removal can be achieved, for example, by punching or fine blanking. Such processes are cost-effective. Removal can also be achieved, for example, by milling. The advantage of milling is the clean circumferential surface of the perforation that it produces and the prevention of fiber-matrix adhesion failure at the fracture surface or edge. Milling prevents the fiber from being completely embedded in the polymer matrix at the perforation's circumference. In this case, separation of fiber and matrix can occur at the fracture surface or edge, allowing the fluid in the hydro bearing to penetrate the polymer matrix more easily via capillary action.Polymer degradation via hydrolysis (in conjunction with the glycol, especially when using a glycol-water mixture) would be promoted; the component could fail prematurely. Separating the penetration has the advantage of easily demonstrating that the penetration does not contain or cross a weld line.

[0061] A method for producing a stopper is also conceivable, comprising the following steps: - Providing a hydraulic bearing stop shell in accordance with the disclosure, - Providing a display-compliant stopper, - Arranging the hydraulic bearing stop shell and the stop stop in a vulcanization cavity, - Filling the vulcanization cavity with rubber into a space between the hydro bearing stop shell and the stop stop, - wherein the rubber covers the circumferential surface of the perforation, preferably at least the fracture surface or fracture edge, more preferably completely, - Vulcanization and shaping of the stopper compound.

[0062] The advantages already described above regarding the hydraulic bearing and the method for manufacturing a hydraulic bearing stop shell also apply analogously to the method for manufacturing a stopper, to which reference is hereby made. To allow for fiber ends in the circumferential surface and / or defects or surface flaws created by cutting, the circumferential surface of the opening can advantageously be coated with elastomer.

[0063] If several corresponding components are disclosed, features and advantages described for only one of the components shall also apply to the other corresponding components.

[0064] Further features, details and advantages of the invention will become apparent from the wording of the claims and from the following description of exemplary embodiments with reference to the drawings. The drawings show: Fig. 1 an exploded view of a hydraulic bearing according to the invention; Fig. 2 a cross-section through a hydraulic bearing stop shell; Fig. 3a a side view of a hydraulic bearing stop shell; Fig. 3b a top view of a hydraulic bearing stop shell and Fig. 4 A schematic view of a hydraulic bearing stop shell with fiber layer.

[0065] In the figures, identical or corresponding elements are designated with the same reference numerals and are therefore not described again unless expedient. Features already described are not described again to avoid repetition and are applicable to all elements with the same or corresponding reference numerals, unless explicitly excluded. The disclosures contained in the entire description are transferable analogously to identical parts with the same reference numerals or component designations. Furthermore, the positional designations chosen in the description, such as top, bottom, side, etc., refer to the directly described and illustrated figure and must be applied analogously to any new position.Furthermore, individual features or combinations of features from the different exemplary embodiments shown and described can also represent independent, inventive or inventive solutions.

[0066] Fig. Figure 1 shows a hydraulic bearing 2, which has a central longitudinal axis Z in the longitudinal direction. It comprises a central core 4, a sleeve 6 which surrounds the core 4 circumferentially, and two stop means 18. The stop means 18 are arranged diametrically with respect to the central longitudinal axis Z. Each stop means 18 comprises a hydraulic bearing stop shell 8, which is placed between the core 4 and the sleeve 6, a stop stop 10, which is placed between the stop stop 10 and the core 4, and an elastomer body 32, which elastically supports the stop stop 10 on the hydraulic bearing stop shell 8.

[0067] Each hydraulic bearing stop shell 8 is made of a fiber-reinforced plastic composite, is seamless, and has a radial opening 12 in the direction R, with the radial direction R being perpendicular to the central longitudinal axis Z. Furthermore, each hydraulic bearing stop shell 8 is elastomer-free on its outer circumference and has a surface projection of less than 100 mm x 100 mm. The opening 12 is bounded by a circumferential edge region 20 with an inner circumferential surface 24. The inner circumferential surface 24 has or is formed by a fracture surface or fracture edge 25. The stop 10 is arranged such that it can project into this opening 12 when loaded in the radial direction R. Each hydraulic bearing stop shell 8 can have a wall thickness W in the range of 3 mm to 5 mm. The wall thickness W corresponds to the diameter of the largest imaginary sphere K that can fit inside the hydraulic bearing stop shell 8.

[0068] The hydraulic bearing 2 further comprises at least two chambers 14, 16, which can be filled with or are filled with a hydraulic fluid and are fluidically connected to each other via a channel. It also includes a support cage 26, which comprises an elastomer coating 28. Each hydraulic bearing stop shell 8 is supported on the outer circumference of the support cage 26.

[0069] In Fig. Figure 4 shows a preferred fiber orientation of a hydraulic bearing stop shell 8 in principle. The hydraulic bearing stop shell 8 can be a hydraulic bearing stop shell 8 as previously described. The circumferential edge region 20 has a thickness S, which can be at most 1 mm. The thickness S lies parallel to the radial direction R. The circumferential edge region 20 also has a width B20 in the range of 1 mm to 10 mm. The inner circumferential surface 24 of the circumferential edge region 20 has a fracture surface or fracture edge 25 or is formed from one.

[0070] It is evident that the hydraulic bearing half-shell 8 comprises fibers 34, with a largely disordered fiber orientation outside the circumferential edge region 20. All these fibers 34 can be present in a disordered orientation in the fiber-reinforced plastic composite semi-finished product or before the production of the hydraulic bearing stop shell 8. After production of the hydraulic bearing stop shell 8, the fibers 34 can include displaced fibers 30 and alignment fibers 22, as explained below.

[0071] Additional ordered fiber orientations are conceivable outside the circumferential region 20. Aligned fibers are present in the circumferential region 20. Aligned fibers can be referred to as alignment fibers 22. A large proportion of the fibers in the circumferential region 20 follow the course of the opening 12 in their circumferential direction U.

[0072] Along the circumferential direction U, the average preferred direction of the fibers 34 deviates from the circumferential direction U by a maximum of 45° across the entire circumferential edge region 20. This means that more fibers are oriented in the circumferential direction U, i.e., perpendicular to it. The angle is specified in a central surface ZF of the corresponding hydraulic bearing stop shell 8, as shown. Fig. Figure 3a shows that fibers 34 running parallel to the circumferential direction U have an angle of 0° to it. Fibers 34 running perpendicular to the circumferential direction U have an angle of 90° to it.

[0073] Each fiber 34 can be symbolized in a mathematical sense by a vector V, as seen exemplified by a fiber 34 in Fig. 4 to the right of the opening 12. This fiber 34 or its vector V is adjacent to a point S 24 in the circumferential surface 24 of the opening 12. A tangent T passes through this point S24. A corresponding angle can be drawn in space between vector V and tangent T, which in this case is 0°. The angle given in degrees (°) can refer to an angle in a central surface of the corresponding hydraulic bearing stop shell.

[0074] The fibers 34 in the circumferential edge region 20, which follow the course of the opening 12 in the circumferential direction U, form a fiber frame 36 by virtue of their orientation, which directly surrounds and reinforces the opening 12. The fiber concentration in the circumferential edge region 20 is higher than in other areas of the hydraulic bearing stop shell 8. More than 50% of the fibers in the circumferential edge region are aligned in the circumferential direction U of the opening 12, i.e., they form an angle of less than 45° with the tangent V. The mean fiber length of the fiber-reinforced plastic composite is greater than 5 mm. The fiber length to fiber thickness ratio is at least 500:1. In the circumferential surface 24, open, sheared, or cut fiber ends 38 are present, resulting from the separating fabrication of the opening 12.

[0075] The hydraulic bearing stop shells 8 can each be made from a fiber-reinforced plastic composite semi-finished product which, with respect to its volume, consists of at least 75% either of a plate-shaped and / or solid-shaped, long glass fiber or continuous fiber reinforced thermoplastic composite semi-finished product or of a composite semi-finished product made of a curable, long glass fiber reinforced polymer resin.

[0076] With reference to Fig.4. The hydraulic bearing stop shells 8 can be manufactured using the following method, which can be a compression molding process. First, a mold with a cavity can be provided. Then, a fiber-reinforced composite semi-finished product can be placed in the mold. The fiber-reinforced composite semi-finished product can be pre-cut so that it does not protrude beyond the edge of the cavity and corresponds to the volume of the finished half-shell with the opening to be punched out. The fiber-reinforced composite semi-finished product is thus smaller than 100 mm x 100 mm, with a thickness not greater than 15 mm, preferably not greater than 8 mm. It is also possible to stack several pre-cut semi-finished products. The mold can then be closed and the fiber-reinforced composite semi-finished product subjected to compression molding. Before the subsequent displacement step, a plasticizing step of the fiber-reinforced composite semi-finished product can be carried out.The closing of the mold can include the sub-step of displacing fibers 30 from an area B12, in which the opening 12 is provided, into the circumferential edge area 20. After the compression molding and / or curing step, a step of separating the opening 12 can be carried out by a separating process. After separation, a hydraulic bearing stop shell 8 is created.

[0077] The arrangement of the fiber-reinforced plastic composite semi-finished product leads to an initial orientation of the fibers of the fiber-reinforced plastic composite semi-finished product. The displacement of the fibers 30 from area B12 of the opening 12 into the circumferential edge area 20 leads to a subsequent orientation of these fibers. The corresponding fibers 30 are reoriented; they can be referred to as alignment fibers 22. The displacement of the fibers 30 can occur along displacement arrows P.

[0078] The fiber-reinforced plastic composite semi-finished product can be a thermoplastic matrix with unoriented continuous fibers 34. The fiber-reinforced plastic composite semi-finished product can be placed in the mold such that fibers 34 are arranged in or project into the area B12 where the opening 12 is provided.

[0079] The invention is not limited to one of the embodiments described above, but can be modified in a variety of ways. All features and advantages arising from the claims, the description, and the drawings, including design details, spatial arrangements, and process steps, can be essential to the invention both individually and in various combinations.

[0080] The invention encompasses all combinations of at least two of the features disclosed in the description, the claims and / or the figures.

[0081] To avoid repetition, features disclosed by the device itself shall also be deemed disclosed by the process and be claimable. Likewise, features disclosed by the process shall be deemed disclosed by the device itself and be claimable. Reference symbol list 2 hydraulic bearings 4 cores 6 sleeve 8 Hydraulic bearing stop shell 10 stop blocks 12 Breakthrough 14th Chamber 16th Chamber 18 Stopping Agents 20 Perimeter border area 22 alignment fibers 24 Circumferential area 25 Break edge 26 support cage 28 Elastomer coating 30 fibers 32 elastomer bodies 34 fibers 36 fiber frames 38 Fiber ends B12 area B20 width K ball P Displacement arrow R Radial direction S strength S24 position T tangent U circumferential direction V vector W wall thickness Z Central longitudinal axis ZF central area

Claims

[1] Hydraulic bearing (2) which has a central longitudinal axis (Z) comprising a core (4), a sleeve (6) which surrounds the core (4), at least two hydraulic bearing stop shells (8) between core (4) and sleeve (6), a stop stop (10) for each hydraulic bearing stop shell (8), which is mounted on the hydraulic bearing stop shell (8) and arranged radially outside to the core (4), wherein each hydraulic bearing stop shell (8) comprises at least one opening (12) in the radial direction (R) which is bounded by a circumferential edge region (20), wherein the corresponding stop stop (10) is arranged such that it can project into this opening (12) when loaded in the radial direction (R), wherein the opening (12) is an opening produced by a separating process and / or the opening (12) has fiber ends (38) of the fiber-reinforced plastic composite on the circumferential surface (24) machined by a separating process, and at least two chambers (14, 16) which can be filled with or are filled with a hydraulic fluid and are fluidically connected to each other via a channel, wherein each hydraulic bearing stop shell (8) is formed from a fiber-reinforced plastic composite, wherein each hydraulic bearing stop shell (8) is a flow-formed part, characterized by, that the hydro bearing stop shells (8) are each made of a fiber-reinforced plastic composite semi-finished product which, with respect to its volume, consists of at least 75% of a plate-shaped and / or solid-shaped, long glass fiber reinforced thermoplastic composite semi-finished product. [2] Hydraulic bearing (2) according to claim 1, characterized by , that each hydraulic bearing stop shell (8) is free of bond lines. [3] Hydraulic bearing (2) according to claim 1 or 2, characterized by that the breakthrough exhibits a uniform fiber break and / or fiber cutting pattern across its entire circumference on its inner circumferential surface. [4] Hydraulic bearing (2) according to one of the preceding claims, characterized by , that the fibers of the circumferential border region (20) are oriented in the circumferential direction (U). [5] Hydraulic bearing (2) according to one of the preceding claims, characterized by, that the mean fiber length of the fibers of the hydro bearing stop shell (8) is greater than 5 mm, preferably greater than 10 mm. [6] Hydraulic bearing (2) according to one of the preceding claims, characterized by , that the hydraulic bearing stop shells (8) have a surface projection of less than 100 mm x 100 mm. [7] Hydraulic bearing (2) according to one of the preceding claims, characterized by , that the hydro bearing stop shells (8) are designed to be elastomer-free on the outer circumference and / or have a separating edge or a separating burr and are supported on an elastomer coating (28) of a support cage (26) of the hydro bearing (2). [8] Method for manufacturing a hydraulic bearing stop shell (8) comprising the following steps: - Providing a form, - Arranging a fiber-reinforced plastic composite semi-finished product in the mold, - Closing the mold and extrusion of the fiber-reinforced plastic composite semi-finished product, - wherein the hydraulic bearing stop shell (8) comprises at least one opening (12) in the radial direction (R) which is bounded by a circumferential edge region (20), wherein the opening (12) is an opening produced by a separating process and / or the opening (12) has fiber ends (38) of the fiber-reinforced plastic composite on the circumferential surface (24) processed by a separating process, wherein each hydraulic bearing stop shell (8) is formed from a fiber-reinforced plastic composite - wherein the hydro bearing stop shells (8) are each made of a fiber-reinforced plastic composite semi-finished product which, with respect to its volume, consists of at least 75% of a plate-shaped and / or solid-shaped, long glass fiber reinforced thermoplastic composite semi-finished product. [9] Method according to claim 8, characterized by, that the step of closing the form includes the substep of displacing fibers (30) from an area (B) in which the perforation (12) is provided, into a circumferential edge (20) that limits the perforation (12). [10] Method according to claim 9, characterized by , that before the displacement step a step of plasticization of the fiber-reinforced plastic composite semi-finished product takes place, so that the fiber-reinforced plastic composite semi-finished product is deformable during the displacement step. [11] Method according to any one of claims 8 to 10 above, characterized by , that after the step of compression molding and / or curing, a step of separating a perforation (12) is carried out by means of a separating process.

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