Bush for anti-vibration bracket, anti-vibration bracket, and method for manufacturing anti-vibration bracket

Abstract

A bushing (6) for an anti-vibration bracket, the bushing (6) comprising an outer structure (20, 24) and an inner sleeve (16), the outer structure (20, 24) comprising a connection structure (21) connected to the inner sleeve (16), the outer structure (20, 24) designed to connect to an opening in an anti-vibration bracket, the inner sleeve (16) comprising a through hole (30) adapted to connect at least partially to a tubular member (18), the connection structure (20) being made of a thermoplastic elastomer (TPE).

Description

[Technical field]

[0001] The present invention relates to a bush for an anti-vibration bracket, an anti-vibration bracket, and a method for manufacturing an anti-vibration bracket. [Background technology]

[0002] Bushings for anti-vibration brackets, anti-vibration brackets and methods of manufacturing anti-vibration brackets are generally known in the prior art.

[0003] Anti-vibration brackets are commonly used in automotive applications, for example as engine mounts. In recent years, great strides have been made in the development of electric vehicles, with more and more electric vehicles now on the road. The electric motors that power electric vehicles exhibit a different vibration range than typical internal combustion engines. As such, means for supporting internal combustion engines cannot be employed to support electric motors while exhibiting similar properties with respect to vibration damping or absorption. In particular, damping or absorption of vibrations generated by electric motors cannot be reliably achieved with absorbers / dampers for internal combustion engines. As a result, new support means for electric motors have been developed.

[0004] WO 2021 / 037919 discloses a bracket for supporting an electric motor on a vehicle chassis, the bracket comprising a first half shell defining a first half subspace and a second half shell defining a second half subspace, the first and second half shells being made from a plastic material, in particular a polymer material, the first and second half shells being fixed to one another, preferably by welding, so as to define a cavity in the bracket including the first and second half subspaces. The bracket has a bushing made from a rubber material.

[0005] Automotive manufacturers and suppliers are constantly striving to develop better, lighter and more cost-effective solutions. Traditional anti-vibration brackets are heavy and complex to manufacture. Summary of the Invention

[0006] An object of the present invention is to provide a bush for an anti-vibration bracket and an anti-vibration bracket that are lighter and easier to manufacture, and a method for easily manufacturing the anti-vibration bracket.

[0007] This object is solved by a bush for an anti-vibration bracket according to independent claim 1, by an anti-vibration bracket according to independent claim 12, by a method for manufacturing an anti-vibration bracket according to independent claim 15 and by a method for manufacturing an anti-vibration bracket according to independent claim 16. Further embodiments are set out in the dependent claims.

[0008] Described below is a bushing for an anti-vibration bracket, the bushing comprising an outer structure and an inner sleeve, the outer structure comprising a connection structure connected to the inner sleeve, the outer structure designed to connect to an opening in the anti-vibration bracket, the inner sleeve comprising a through hole adapted to connect at least partially to a tubular member, the connection structure being made from a thermoplastic elastomer (TPE).

[0009] The bushings can be made of several materials, in particular one or more polymeric materials such as plastic or rubber in addition to TPE. Each material used may be elastomeric. The elastomeric material allows for reversible displacement and reversible extension of the structural components of the bushing. When the structural components are displaced, a damping force is generated in the opposite direction of the displacement, thereby effectively absorbing the vibration energy caused by the vibration-generating components held in the bushing.

[0010] Thermoplastic elastomers, sometimes referred to as thermoplastic rubbers, are a type of copolymer, or physical mixture of certain polymers, consisting of materials that have both thermoplastic and elastomeric properties. While most elastomers commonly used for respective bushings are thermosets, thermoplastics can be relatively easily used in manufacturing, for example, by additive manufacturing processes such as injection molding and 3D printing. Other advantages of using thermoplastic elastomers are their ability to stretch to moderate elongations and return to nearly their original shape, giving them a longer lifespan and a wider physical range than other materials.

[0011] Suitable TPE materials include PP-EPDM (TPE and TPE-V), PP-SEBS, TPE-U. The use of TPEs has multiple advantages compared to the use of known materials such as rubber. TPEs have significant advantages in the manufacturing process. First, TPEs are often less expensive than rubber, which lowers the cost of goods and results in cheaper parts. Second, TPEs are cheaper to manufacture because they do not require the use of a vulcanized core. Third, TPEs do not require an adhesive to form a material connection with another part, such as the anti-vibration bracket body or sleeve. Fourth, the use of TPEs allows for different, more effective manufacturing methods such as 2K molding. It also allows for faster curing times and less contamination.

[0012] Additionally, TPEs offer advantages in certain use cases. TPEs have a lower specific gravity than commonly used damped elastomeric materials such as rubber, allowing the manufacture of bushings that are lighter than those made from more common materials. Due to the low specific gravity of TPE, the eigenmodes are generally at higher frequencies, which are less of a problem than lower frequencies. Also, due to the high damping at the eigenmodes, the eigenmodes can be engineered to be significantly reduced in amplitude.

[0013] The inner sleeve can be connected directly or indirectly to a mounting structure such as a rod or bar, which itself can be connected to a motor, especially an electric motor, a gearbox, etc., and the connection structure can be connected to an anti-vibration bracket, which itself can be attached to a body or chassis part of the vehicle, or vice versa. The indirect connection to the mounting structure can be achieved by a sleeve, which itself can be made of plastic or metal to allow rotation of the mounting structure relative to the bush. Typically, each vibration-generating part held by an anti-vibration bracket, such as an electric motor, is held by multiple anti-vibration brackets, so that multiple respective bushes may be used to support a single vibration-generating part.

[0014] A specific use of such bushings includes, for example, supporting an electric motor in a vehicle, such as a fully electric or hybrid vehicle. Such an electric motor may be any electric motor capable of converting electrical energy into rotational motion, thereby driving one or more wheels of the vehicle. Electric motors commonly used in vehicle drives may generate vibrations in the frequency range of 1 to 2000 Hz. Anti-vibration brackets utilizing such bushings may be designed to damp and absorb vibrations in the full frequency range, thereby effectively damping all of the expected frequency ranges exhibited by electric motors. The various components of the anti-vibration bracket may have different damping characteristics, with the bushings typically damping the lower frequency ranges and the bracket body, in some embodiments in combination with other dampers included in the bracket body, damping the higher frequency ranges exhibited by the vibration-generating components.

[0015] Another aspect of achieving a specified material stiffness with a lighter bushing is that the natural modes of the bushing will typically be higher than a heavier bushing, meaning that one or more resonant frequencies can be shifted further away from the resonant frequencies of components directly or indirectly connected to the bushing, improving the NVH characteristics.

[0016] Also, the peak amplitude of each eigenmode of the bushing can be significantly reduced relative to commonly known bushings, and the damping characteristics are still sufficient for the eigenmodes. The bushing may be a one-piece component, that is, the bushing may comprise a single piece.

[0017] According to a first alternative embodiment, the outer structure comprises an outer sleeve and the connection structure is connected to the outer sleeve. The connection structure and the outer sleeve may be integrally formed, i.e. made from a single piece of material.

[0018] This results in a bushing that is integrally constructed as a single structural unit, including an inner sleeve, an outer sleeve, and at least two helical blades connecting the inner and outer sleeves, respectively, resulting in a one-piece bushing construction that can withstand high loads before failing, allowing for a more compact bushing design.

[0019] According to other further embodiments, the inner sleeve and / or the outer sleeve are made from a second plastic material. This allows the selection of a material suited to the respective requirements, for example a non-elastomeric inner sleeve which can be used to avoid the need for a separate connecting sleeve.

[0020] According to yet another further embodiment, the bushing is made entirely of TPE or the spring element of the bushing is made of TPE, preferably entirely of TPE. The use of a single material for the bushing or spring member allows for simple and efficient manufacturing processes, such as a single-step molding process to create the bushing, which can be part of a multi-step manufacturing process for the anti-vibration bracket.

[0021] The spring member may comprise an inner sleeve and / or an outer structure. The spring member may be the main spring member of the bushing and / or the outer sleeve may be directly connected to the inner sleeve.

[0022] According to another further embodiment, the connection structure comprises at least two blades connecting the outer structure and the inner sleeve. The blades are designed such that two of the three dimensions are significantly greater than the third, for example, the length and radial blade width of a helical blade are significantly greater than the blade thickness. The surface of the blade can be curved, the length, width, and thickness can vary across the blade, and the blade can be thicker in some areas than in others.

[0023] According to another further embodiment, the connection structure consists of a blade or at least one pair of blades. This enables a variety of possible manufacturing methods to be used, including additive manufacturing processes such as injection molding and 3D printing, as the blade or set of blades can be designed to suit such processes.

[0024] According to yet another further embodiment, the at least two blades have a structure that extends helically relative to the axis of the through hole. The helical structure allows a defined material stiffness to be achieved using less material than with other known connection structures, so that each bush is lighter than known bushes with similar material properties. This effect can be increased by the fact that for a given stiffness, each bush can be designed smaller and therefore lighter than known bushes. The helical structure of the blade also introduces another dimension of design freedom, allowing a better adjustment of the damping properties of the bush to the respective application.

[0025] Additionally, the use of helical blades allows for fine tuning of different stiffness and damping characteristics in different directions, e.g., axial, radial, and torsional characteristics depend on the design of the helical blades and may also depend on the direction of the torsional moment introduced into the bushing.

[0026] Moreover, and surprisingly, the combination of helical structures on the one hand with TPEs on the other hand produces a rather beneficial effect: the use of TPEs makes helical structures possible or even improved, thus further enhancing the above-mentioned advantages: in particular, on the one hand, elongated structures can be produced by TPEs, without any functional loss on the other hand.

[0027] According to another further embodiment, at least two blades have a curved cross-sectional shape with essentially parallel sidewalls over at least 50% of their path of extension. Each design can have multiple curvatures, e.g., an S-shape. The curved cross-sections can allow for different damping characteristics depending on the relative direction of the moment introduced into the bushing, e.g., clockwise vs. counterclockwise.

[0028] The curved blades can be designed such that uncontrolled buckling of the structure is avoided in the direction of compression of the curved blade. Instead, a controlled folding of the blade structure occurs in the direction of compression.

[0029] The maximum amplitude can also be increased by curved, particularly S-shaped, blades, resulting in higher amplitudes for a given size bushing, particularly in the direction of extension as opposed to compression, or a smaller size bushing for a given maximum amplitude specification.

[0030] According to other further embodiments, the at least two blades have a pitch in the range of 30 mm to 300 mm and / or cover an inclination angle between 0° and 80°, in particular 1° to 80°, in particular 10° to 50° and / or have a path length of at least 1.1 times the distance between the inner sleeve and the outer sleeve or between the inner sleeve and the opening in the anti-vibration bracket.

[0031] The above pitch ranges can provide the required damping specifications while allowing for a variety of manufacturing methods such as injection molding and additive manufacturing processes such as 3D printing. Typically, the larger the pitch, the stiffer the bushing will be both radially and axially. Each tilt angle configuration allows each bushing to be demolded at a specific demold angle through the spiral motion of the mold inner features in a high speed manufacturing line.

[0032] The inclination angle of the blades can be used to adjust the ratio of radial to axial stiffness. The smaller the inclination angle, the lower the ratio of radial to axial stiffness. The inclination angle can span between the axis of the through-hole on the one hand and the helical structure or the course of the respective blade on the other hand. An inclination angle of 0° can be considered as a zero angle in the mathematical sense. At such a zero angle, the blades can extend radially without any circumferential inclination or the blades can extend parallel to the axis of the through-hole. The inclination angle particularly relates to the measure by which the blades are inclined with respect to the axis of the through-hole. This causes the blades to wrap around the axis.

[0033] A path length longer than the distance between the inner sleeve and the outer sleeve or opening in the vibration isolation bracket allows for further fine-tuning of the bushing characteristics, including allowing for blades that do not extend radially outward, for example at an angle to the radial direction, allowing for more travel and higher vibration amplitudes.

[0034] According to another further embodiment, the at least two blades cover a radial angle between 0° and 90°, in particular between 1° and 85°, in particular between 70° and 80°. The radial angle of the blades can be used to make them easier to release from the mold. This advantage is particularly evident in the case of production by injection molding. The radial angle can span between the axis of the through hole on the one hand and the mean course of the helical structure or the respective blade in the longitudinal section on the other hand. The radial angle can also lie in the longitudinal section through the bush. The axis can also lie in the longitudinal section. A radial angle of 0° can be considered as a zero angle in the mathematical sense. At such a zero angle, the blades can extend radially without circumferential tilt or the blades can extend parallel to the axis of the through hole.

[0035] According to other embodiments, each of the blades may extend over a circumferential angular range of 0° to a multiple of 360°, preferably 0° to 270°, more preferably 0° to 180°. The circumferential angle can be located in the transverse plane. As a result, the blade is wound in a spiral around the axis of the through hole. In this range, an optimum is achieved between the beneficial effects mentioned above (material stiffness, less material used, lighter bushing weight, similar material properties) and manufacturability. For example, if the blade needs to be demolded after production, the molded part can be easily removed. Furthermore, this feature allows greater flexibility to adjust the stiffness ratio in one or more spatial directions.

[0036] If the blade is manufactured by injection molding, a circumferential angle in the range of 0° to 360°, preferably 0° to 270°, more preferably 0° to 180° is advantageous for easy demolding. If the blade is manufactured using an additive manufacturing process such as 3D printing, a larger circumferential angle can also be chosen, since the demoldability aspect is not relevant there.

[0037] According to other further embodiments, the number of blades is between 2 and 12. The number of blades, as well as the stiffness of the bushing, can determine the maximum load that can be tolerated: a given load is distributed among the blades, and the load per blade is smaller the more blades a bush has.

[0038] According to other further embodiments, the at least two blades are evenly distributed around the circumference of the inner sleeve, or the blades are unevenly distributed around the circumference of the inner sleeve. The evenly distributed blades can provide axially isotropic damping characteristics as well as rotational symmetry providing greater flexibility during assembly.

[0039] Unequally spaced blades allow for grouped arrangements where two or more blades are positioned closer to each other than other blades. Such blade arrangements may be evenly spaced around the circumference of the inner sleeve. In that way, a different radial stiffness may be achieved compared to non-grouped blades. Furthermore, depending on the respective placement of the unevenly distributed blades, the radial stiffness in different directions can be adjusted differently to compensate for static loads.

[0040] According to another further embodiment, at least two blades have a smooth transition to the outer sleeve and / or the inner sleeve. A smooth transition can reduce the shear forces and avoid high peaks in material tension, which can significantly reduce the risk of the bush failing due to fracture in high overload situations. The smooth transition can be a radiused section.

[0041] According to another further embodiment, the bush may include a core member. The core member may be arranged in the through hole. The core member may in particular be an independent or separate part from the spring member. The core member may be hollow cylindrical in shape and serves to connect other members, for example tube-shaped members. The inner sleeve may rest against the outer periphery of the core member and is preferably rigidly connected to the core member. The core member further serves for a stable connection with other members.

[0042] It is also conceivable that the bushing is formed from only two parts, namely the spring element and the core element. The spring element can comprise an inner sleeve and an outer structure. The core element can be attached to the spring element in a single step during the manufacture or molding of the spring element. As a result, the advantages of the invention can be realized even when using core elements known per se.

[0043] It is also conceivable that the outer structure and / or the core member have circumferential longitudinal ribs extending along the axis of the bracket through hole. It is also conceivable that the bracket through hole and / or the bushing through hole are formed with longitudinal grooves for the respective longitudinal ribs. However, it is also conceivable that the ribs and grooves are reversed on the respective other members. Such rib connections improve the interference fit of the respective members, especially under rotational loads about the axis of the bracket through hole.

[0044] A first independent aspect relates to an anti-vibration bracket comprising a bracket body, the bracket body comprising an opening for a bushing as previously described, the bushing being connected to the opening via an outer structure.

[0045] The bracket body can be made of one or more materials different from the bushings. The bracket body can in particular be made of PA, which does not have elastomeric properties like the bushings themselves. The bracket structure, together with the at least one bushing as described above, is designed to exhibit defined static and dynamic properties that provide effective damping of vibrations over a wide frequency spectrum introduced by the at least one vibration-generating component.

[0046] The bracket body can be designed to be lightweight and stiff through the use of reinforcing structures, such as reinforcing walls that extend in one or more directions. The reinforcing structures can cross each other to provide multi-dimensional structural stiffness.

[0047] The bracket body and at least one bushing can be designed to have different damping characteristics to provide broad frequency damping of vibration, with some portions of the frequency spectrum being absorbed by the bushing and other portions being absorbed by the bracket body.

[0048] According to a first further embodiment, the bushing is made by overmolding the bracket body. In this way, the bushing can be bonded to the bracket body in a single 2K molding manufacturing step without the use of adhesives.

[0049] According to yet another further embodiment, the bracket body includes a mounting structure for mounting the bracket to an object. The bracket body can be attached to a vibration-generating part, e.g. an electric motor held in the anti-vibration bracket via at least one bushing, while the bracket body can be attached to a body part, frame, chassis, etc. The latter attachment can be achieved via a damping material, such as a rubber or TPE sleeve, to improve the NVH characteristics of the anti-vibration bracket.

[0050] A further independent aspect relates to a method for manufacturing an anti-vibration bracket as described above, the method comprising the steps of placing a bracket body in an injection mould, overmolding the bracket body with a thermoplastic elastomer (TPE) to form a bushing or a spring member of the bushing, and demolding the bracket after the thermoplastic material has sufficiently cured.

[0051] If the bushing or spring member is directly overmolded onto the bracket body, the use of adhesives to attach the bushing to the bracket body can be avoided, reducing the number of manufacturing steps as well as the material used. It can also reduce the problem of improper adhesion of the bushing to the bracket body. Furthermore, the mounting structure provided on the bushing can be of different dimensions, saving space and weight, compared to conventional anti-vibration brackets.

[0052] A further independent aspect relates to a method for manufacturing an anti-vibration bracket as described above, the method including providing a two-component injection mold, injecting a first plastic material to form a bracket body, allowing the first plastic material to sufficiently harden, overmolding the bracket body with a thermoplastic elastomer (TPE) to form a bushing or a spring member of the bushing, and demolding the bracket after the thermoplastic material forming the bushing or the spring member of the bushing has sufficiently hardened.

[0053] According to this embodiment, a vibration-proof bracket can be provided in a single 2K molding process. In a first step of the 2K molding process, a mold consisting of multiple mold parts can be provided to mold a bracket body structure that can include one or more through holes for a structure to be formed in a further step of the 2K molding process. A first material can be injected into the cavity formed by the mold and cured to stabilize the shape.

[0054] A portion of the mold part can then be removed, a different mold part or set of mold parts can be placed against the bracket body, and the TPE can be injected into one or more cavities formed by the mold and bracket body. The TPE can bond directly to the bracket body, forming a strong connection between the two materials. The material of the bracket body can be selected depending on its ability to bond with the TPE. Suitable materials include short glass fiber reinforced polymers such as polyamide, polyester or polypropylene that have a molding temperature below 120°C.

[0055] On top of the bushing further components, such as further parts or attachment structures to the lining, can also be formed in this respective step. According to a further embodiment of the method described above, the inner form forming the blade of the bush is deformed by means of a spring and a helical guide groove which guides the inner form. In that way, the demolding path of the inner mold is precisely defined and the demolding process results in fewer defects.

[0056] According to further inventive aspects, it is also conceivable to use additive manufacturing processes, e.g. 3D printing, as a manufacturing process instead of molding. Furthermore, features disclosed in the context of molding apply equally to additive manufacturing processes, insofar as this is technically possible. Where a range of values ​​extends from a first value to a second value, the two limits are included in the range.

[0057] Further features and details are given in the following description, where applicable with reference to the drawings, in which at least one exemplary embodiment is described in detail. The described and / or illustrated features constitute subject matter, either on their own or in any possible and meaningful combination, and are ultimately also independent of the claims. In particular, they may be subject matter of one or more separate applications. The figures are shown diagrammatically. [Brief description of the drawings]

[0058] [Figure 1]1 is a three-dimensional perspective view of a first embodiment of the anti-vibration bracket of the present invention. FIG. [Diagram 2] FIG. 2 is an exploded perspective view of the vibration isolation bracket of FIG. [Diagram 3] 2 is a three-dimensional perspective view of a bush of the vibration-proof bracket of FIG. 1. FIG. [Figure 4] FIG. 4 is a front view of the bush of FIG. 3. [Diagram 5] FIG. 4 is a vertical cross-sectional view of the bushing of FIG. [Figure 6] FIG. 4 is a three-dimensional perspective view of a second embodiment of the anti-vibration bracket according to the present invention. [Figure 7] FIG. 7 is an exploded perspective view of the vibration isolation bracket of FIG. 6. [Figure 8] FIG. 7 is a three-dimensional perspective view of a bush of the vibration-isolating bracket of FIG. 6. [Figure 9] FIG. 9 is a front view of the bushing of FIG. 8. [Figure 10] FIG. 9 is a vertical cross-sectional view of the bushing of FIG. 8. [Figure 11] FIG. 11 is a three-dimensional perspective view showing a third embodiment of the anti-vibration bracket according to the present invention. [Figure 12] FIG. 12 is an exploded perspective view of the vibration isolation bracket of FIG. [Figure 13] 12 is a three-dimensional perspective view of a bush of the vibration-proof bracket of FIG. 11. FIG. [Figure 14] FIG. 14 is a front view of the bushing of FIG. 13. [Figure 15] FIG. 14 is a side view of the bushing of FIG. 13. [Figure 16] FIG. 11 is a three-dimensional perspective view showing a fourth embodiment of the anti-vibration bracket according to the present invention. [Figure 17] FIG. 17 is an exploded perspective view of the vibration isolation bracket of FIG. 16. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0059] For purposes of improving readability and clarity, identical or similar features in different embodiments, or features having the same or similar properties or functions, may be labeled with the same reference numerals.

[0060] FIG. 1 is a perspective view showing an anti-vibration bracket 2. As shown in FIG. The vibration isolation bracket 2 comprises a bracket body 4 and a bushing 6. The bushing 6 is an integral structural unit. The bushing 6 is disposed in a through hole 8 located generally on one side of the bracket body 4. On the opposite side of the bracket body 4, three mounting holes 10 are located. The bushing 6 is designed for attachment to a vibration generating component, such as an electric motor in an electric vehicle. The mounting holes 10 are arranged for attachment to a structural component of the vehicle, such as the vehicle frame, using threaded bolts.

[0061] The mounting hole 10 according to this embodiment is provided with an elastomeric lining 12 that avoids low frequency noises such as rattles caused by different vibration sources such as road irregularities that are introduced into the vehicle through the vehicle suspension. Other embodiments may not require an additional lining depending on the circumstances.

[0062] The bracket body 4 has a three-dimensional shape designed to fit the respective mounting shapes of the vehicle and the vibration-generating component, e.g., an electric motor. The bracket body 4 is designed to be lightweight and strong enough to withstand the static and dynamic forces exhibited during typical vehicle use. The bracket body 4 may be of one-piece structure. The through-holes 8 and the mounting holes 10 are surrounded by a bracket body structure sufficient to absorb the forces introduced through the vibration-generating component.

[0063] To reduce weight, the bracket body 4, instead of being made from a solid block of material, is provided with a series of reinforcing ribs 14. The reinforcing ribs 14 extend in different directions, some of which are arranged generally perpendicular to the axis x of the bushing 6, others extending radially and / or parallel to the axis x. The reinforcing ribs 14 can reinforce various structural components of the bracket body 4.

[0064] 1 and 2, the bush 6 forms an inner sleeve 16 which holds a separate sleeve 18. The separate sleeve 18 is designed to receive a mounting structure attached to a vibration-generating component, for example a respective rod formed on a respective electric motor. The sleeve 18 is made of a harder material than the bush 6 in order to absorb static and dynamic forces. The separate sleeve 18 is not necessary to receive the mounting structure of the vibration-generating component. The separate sleeve 18 does not need to form part of the bush 6, 6', 6'', 6''''.

[0065] Moving radially outward, the inner sleeve 16 transitions into a number of blades 20 that are part of a connecting structure 21 that connects the inner sleeve 16 to an outer structure 22. The outer structure 22 connects the bushing 6 to the bracket body 4. Part of the outer structure 22 in the embodiment described here is an outer sleeve 24. The outer sleeve 24 is bonded to the bracket body 4 as described below. The spring member 9 comprises the inner sleeve 16 and the outer structure 22.

[0066] In other embodiments, the outer sleeve 24 may not be provided and the blade 20 may be directly connected to the through hole 8 of the bracket body 4, in which case the connection structure and the outer structure are identical.

[0067] The bracket body 4 and the sleeve 18 can be made from a polymer material such as polyamide (PA) or a fibre-reinforced polymer material, in particular a short fibre-reinforced polymer material, here polyamide, while the lining 12 and the bushing 6 are made from TPE. The anti-vibration bracket 2 is manufactured using a 2K moulding process, in a first step the bracket body 4 is formed from PA and in a second step the bushing 6 and the lining 12 are manufactured by overmolding the bracket body 4 with TPE.

[0068] As can be seen in FIG. 2, the bracket body 4 has a mounting surface 26 at the through hole 8 which is used to bond the mounting surface 28 of the outer sleeve 24 of the bushing 6 to the bracket body 4 during curing of the TPE without the use of additional adhesives.

[0069] The sleeve 18 is retained within a through hole 30 formed by the inner sleeve 16 of the bushing 6. In some embodiments, the sleeve 18 may be glued to the bushing 6, while in other embodiments, the sleeve 18 may be removable and retained by a friction fit. The sleeve 18 includes a hole 32 for receiving a mounting structure of the vibration generating component to be attached.

[0070] FIG. 3 is an enlarged perspective view of the bush 6. As shown in FIG. The bushing 6 includes three blades 20 evenly spaced around the circumference of the inner sleeve 16 such that the distance between each successive blade 20 is the same.

[0071] As can be seen in figures 3 to 5, the blades 20 run in an S-shape from the inner sleeve 16 towards the outer sleeve 24. The shape of the blades 20 allows for an increase in maximum amplitude and a defined bending of the blades 20 under load instead of an arbitrary buckling. The dotted lines indicate the course E of the blades 20, which means that the respective course E can also be traced in the illustrated longitudinal sections.

[0072] The distance G between the inner sleeve 16 and the outer sleeve 24 is defined by the outer diameter d of each of the inner sleeves 16 and the inner diameter D of the outer sleeve 24. The path length S of the blades 20 between the connection points of each of the inner sleeve 16 and the outer sleeve 24 is about 1.2 times longer than the distance G in certain embodiments.

[0073] The connections 20.1, 20.2 to the inner sleeve 16 and outer sleeve 24 are rounded to provide a smooth transition to the inner sleeve 16 and outer sleeve 24 respectively to avoid fracture of the bushing structure due to overload.

[0074] The intermediate portion 20.3 between the connecting portions 20.1, 20.2 has substantially parallel side walls 20.A, 20.B and therefore has a substantially constant material thickness to facilitate the demolding process.

[0075] The blades 20 extend in a spiral shape along the axis x of the bush 6. The spiral arrangement of the blades 20 generally results in a lower stiffness compared to axially arranged blades, so that materials with elastomeric properties, which are generally stiffer compared to rubber materials, can be used. The number of blades 20 and the geometrical properties of the blades 20 can be used to adjust to different requirements.

[0076] Each of the blades 20 extends over a circumferential angle U of 180° in the embodiment shown. The pitch P of the blades 20 in the first embodiment is greater than the total axial length L of the bushing 6. This makes it possible to facilitate the deformation process of each die.

[0077] The inclination angle B of the blade 20 with respect to the axis x can be designed to determine the ratio of radial stiffness to axial stiffness. The inclination angle B specifically relates to the measure by which the blade 20 is inclined with respect to the axis x, such that the blade 20 wraps around the axis x. The inclination angle B is between the axis x and the course E of the blade 20. In the illustrated embodiment, the inclination angle B is 67°.

[0078] Each blade 20 has a radial angle C. The radial angle C spans, on the one hand, the axis x of the through hole 8 and, on the other hand, the helical structure or the average course of each blade 20 in a longitudinal section. In the embodiment shown, the radial angle C is 72°.

[0079] The inner sleeve 16 extends beyond the mounting surface 28 in the direction of the axis x, so that the axial length l of the outer sleeve 24 is smaller than the overall axial length L. The blades 20 therefore transition conically from the inner sleeve 16 to the outer sleeve 24.

[0080] 6 to 10 show a second embodiment of an anti-vibration bracket 2'. The anti-vibration bracket 2' shown in Figure 6 comprises a bracket body 4 and a bushing 6'. The bushing 6' is an integral unit. The bushing 6' is disposed in a through hole 8 located generally on one side of the bracket body 4. On the opposite side of the bracket body 4, three mounting holes 10 are located. The bushing 6' is designed to be mounted on a vibration-generating component such as an electric motor in an electric vehicle.

[0081] The mounting hole 10 in this embodiment is arranged for attachment to a structural member of the vehicle, such as the vehicle frame, using a threaded bolt. The mounting hole 10 includes an elastomeric lining 12 that avoids low frequency noise such as rattle caused by different vibration sources, such as road irregularities, that are introduced to the vehicle through the vehicle suspension. In other embodiments, no additional lining may be required depending on the circumstances.

[0082] The bracket body 4 has a three-dimensional shape designed to fit the respective mounting shapes of the vehicle and the vibration-generating component, e.g., an electric motor. The bracket body 4 is designed to be lightweight and strong enough to withstand the static and dynamic forces exhibited during typical vehicle use. The bracket body 4 may be of one-piece structure. The through-hole 8 and the mounting hole 10 are surrounded by a bracket body structure sufficient to absorb the forces introduced through the vibration-generating component.

[0083] To reduce weight, the bracket body 4, instead of being made from a solid block of material, is provided with a series of reinforcing ribs 14. The reinforcing ribs 14 extend in different directions, some of which are generally arranged approximately perpendicular to the axis x of the bushing 6, others extending radially and / or parallel to the axis x. The reinforcing ribs 14 can reinforce various structural components of the bracket body 4.

[0084] 6 and 7, the bushing 6' forms an inner sleeve 16 which holds a separate sleeve 18 designed to receive a vibration generating component, e.g. a mounting structure attached to a respective rod formed in a respective electric motor. The sleeve 18 is made of a harder material than the bushing 6 in order to absorb static and dynamic forces.

[0085] Moving radially outward, the inner sleeve 16 transitions into a number of blades 20 that are part of a connecting structure 21 that connects the inner sleeve 16 to an outer structure 22. The outer structure 22 connects the bushing 6' to the bracket body 4. Part of the outer structure 22 in the embodiment described here is an outer sleeve 24. The outer sleeve 24 is bonded to the bracket body 4 as described below. The spring member 9 comprises the inner sleeve 16 and the outer structure 22.

[0086] In other embodiments, the outer sleeve 24 may not be provided and the blade 20 may be directly connected to the through hole 8 of the bracket body 4, in which case the connection structure and the outer structure are identical.

[0087] The bracket body 4 and the sleeve 18 can be made from a polymer material such as polyamide (PA) or a fibre, in particular a short fibre reinforced polymer material, here polyamide, while the lining 12 and the bushing 6 are made from TPE. The anti-vibration bracket 2 is manufactured using a 2K moulding process, in a first step the bracket body 4 is formed from PA and in a second step the bushing 6 and the lining 12 are manufactured by overmolding the bracket body 4 with TPE.

[0088] As can be seen in FIG. 7, the bracket body 4 has a mounting surface 26 at the through hole 8 which is used to bond the mounting surface 28 of the outer sleeve 24 of the bushing 6' to the bracket body 4 during hardening of the TPE without the use of additional adhesive.

[0089] The sleeve 18 is retained within a through hole 30 formed by the inner sleeve 16 of the bushing 6'. In some embodiments, the sleeve 18 can be glued to the bushing 6', while in other embodiments the sleeve 18 can be removable and retained by a friction fit. The sleeve 18 includes a hole 32 for receiving a mounting structure of the vibration-producing component to be attached.

[0090] FIG. 8 is an enlarged perspective view of the bush 6'. The bushing 6' comprises two pairs of blade sets 32. Each blade set 32 ​​is made up of two blades 20 arranged adjacent to each other. The blade sets 32 themselves are evenly spaced around the circumference of the inner sleeve 16. By using the blade sets 32 instead of individual blades, a different radial stiffness can be achieved compared to the individual blades.

[0091] 8-10, the blades 20 extend in an S-shape from the inner sleeve 16 to the outer sleeve 24. The shape of the blades 20 allows for increased maximum amplitude and defined bending of the blades 20 under load instead of arbitrary buckling.

[0092] The distance G between the inner sleeve 16 and the outer sleeve 24 is defined by the outer diameter d of the inner sleeve 16 and the inner diameter D of the outer sleeve 24. The path length S of the blade 20 between the respective connection points of the inner sleeve 16 and the outer sleeve 24 is about 1.2 times longer than the distance G in certain embodiments.

[0093] The connection portions 20.1, 20.2 to the inner sleeve 16 and outer sleeve 24 are rounded to provide a smooth transition to the inner sleeve 16 and outer sleeve 24 respectively to avoid fracture of the bushing structure due to overload. The intermediate portion 20.3 between the connection portions 20.1, 20.2 has substantially parallel side walls 20.A, 20.B and therefore a substantially constant material thickness to facilitate the demolding process.

[0094] The blades 20 extend in a spiral manner along the axis x of the bush 6'. The spiral arrangement of the blades 20 generally results in a lower stiffness compared to axially arranged blades, so that materials with elastomeric properties, which are generally stiffer compared to rubber materials, can be used. The number of blades 20 and the geometrical characteristics of the blades 20 can be used to adjust to different requirements.

[0095] Each of the blades 20 extends over a circumferential angle U of 120° in the illustrated embodiment. The pitch P of the blades 20 according to the first embodiment is greater than the total axial length L of the bushing 6'. This makes it possible to facilitate the deformation process of the respective dies.

[0096] The inclination angle B of the blade 20 with respect to the axis x can be designed to determine the ratio of radial stiffness to axial stiffness. The inclination angle B specifically relates to the measure by which the blade 20 is inclined with respect to the axis x, such that the blade 20 wraps around the axis x. The inclination angle B is between the axis x and the course E of the blade 20. In the illustrated embodiment, the inclination angle B is 28°.

[0097] Each blade 20 has a radial angle C. The radial angle C spans, on the one hand, the axis x of the through hole 8 and, on the other hand, the helical structure or the average course of the respective blade 20 in a longitudinal section. In the embodiment shown, the radial angle C is 35°.

[0098] The inner sleeve 16 extends beyond the mounting surface 28 in the direction of the axis x, so that the axial length l of the outer sleeve 24 is smaller than the overall axial length L. The blades 20 therefore transition conically from the inner sleeve 16 to the outer sleeve 24.

[0099] 11 to 15 show a third embodiment of an anti-vibration bracket 2''. The anti-vibration bracket 2'' shown in FIG. 11 comprises a bracket body 4 and a bushing 6''. The bushing 6'' is an integral unit. The bushing 6'' is disposed in a through hole 8 located generally on one side of the bracket body 4. On the opposite side of the bracket body 4, three mounting holes 10 are arranged. The bushing 6'' is for mounting to a vibration-generating component, such as an electric motor in an electric vehicle. The mounting holes 10 are arranged for mounting to a structural component of the vehicle, such as the vehicle frame, using threaded bolts.

[0100] The mounting hole 10 according to this embodiment is provided with an elastomeric lining 12 that avoids low frequency noises such as rattles caused by different vibration sources such as road irregularities that are introduced into the vehicle through the vehicle suspension. In other embodiments, depending on the circumstances, no additional lining may be required.

[0101] The bracket body 4 has a three-dimensional shape designed to fit the respective mounting shapes of the vehicle and the vibration-generating component, e.g., an electric motor. The bracket body 4 is designed to be lightweight and strong enough to withstand the static and dynamic forces exhibited during typical vehicle use. The bracket body 4 may be of one-piece structure. The through-hole 8 and the mounting hole 10 are surrounded by a bracket body structure sufficient to absorb the forces introduced through the vibration-generating component.

[0102] To reduce weight, the bracket body 4, instead of being made from a solid block of material, is provided with a series of reinforcing ribs 14. The reinforcing ribs 14 extend in different directions, some of which are arranged generally perpendicular to the axis x of the bushing 6, others extending radially and / or parallel to the axis x. The reinforcing ribs 14 can reinforce various structural components of the bracket body 4.

[0103] 11 and 12, the bushing 6'' forms an inner sleeve 16 which holds a separate sleeve 18 designed to receive a vibration generating component, e.g. a mounting structure attached to a respective rod formed in a respective electric motor. The sleeve 18 is made of a harder material than the bushing 6 in order to absorb static and dynamic forces.

[0104] Moving radially outward, the inner sleeve 16 transitions into a number of blades 20 that are part of a connecting structure 21 that connects the inner sleeve 16 to an outer structure 22. The outer structure 22 connects the bushing 6'' to the bracket body 4. A further part of the connecting outer structure 22 in the embodiment described here is the outer sleeve 24. The outer sleeve 24 is glued to the bracket body 4 as described below. The spring member 9 comprises the inner sleeve 16 and the outer structure 22.

[0105] In other embodiments, the outer sleeve 24 may not be provided and the blade 20 may be directly connected to the through hole 8 of the bracket body 4, in which case the connection structure and the outer structure are identical.

[0106] The bracket body 4 and the sleeve 18 can be made from a polymer material such as polyamide (PA) or a fibre, in particular a short fibre reinforced polymer material, here polyamide, while the lining 12 and the bushing 6 are made from TPE. The anti-vibration bracket 2'' is manufactured using a 2K moulding process, in a first step the bracket body 4 is formed from PA and in a second step the bushing 6 and the lining 12 are manufactured by overmolding the bracket body 4 with TPE.

[0107] As can be seen in FIG. 12, the bracket body 4 has a mounting surface 26 at the through hole 8, which is used to bond the mounting surface 28 of the outer sleeve 24 of the bushing 6'' to the bracket body 4 during curing of the TPE without the use of additional adhesive.

[0108] The sleeve 18 is retained in a through hole 30 formed by the inner sleeve 16 of the bushing 6''. In some embodiments, the sleeve 18 can be glued to the bushing 6'', while in other embodiments the sleeve 18 can be removable and retained by a friction fit. The sleeve 18 includes a hole 32 for receiving a mounting structure of the vibration-producing component to be attached.

[0109] FIG. 13 is an enlarged perspective view of the bushing 6''. The bushing 6'' comprises ten blades 20. The blades 20 are evenly spaced around the circumference of the inner sleeve 16 and extend radially outward. The relatively large number of blades 20 increases the maximum allowable force that the bushing 6'' can absorb.

[0110] 13-15, the blade 20 extends in an S-shape from the inner sleeve 16 to the outer sleeve 24. The shape of the blade 20 allows for increased maximum amplitude and defined bending of the blade 20 under load instead of arbitrary buckling.

[0111] The distance G between the inner sleeve 16 and the outer sleeve 24 is defined by the outer diameter d of the inner sleeve 16 and the inner diameter D of the outer sleeve 24. The path length S of the blade 20 between the respective connection points of the inner sleeve 16 and the outer sleeve 24 is about 1.2 times longer than the distance G in certain embodiments.

[0112] The connection portions 20.1, 20.2 to the inner sleeve 16 and outer sleeve 24 are rounded to provide a smooth transition to the inner sleeve 16 and outer sleeve 24 respectively to avoid fracture of the bushing structure due to overload. The intermediate portion 20.3 between the connection portions 20.1, 20.2 has substantially parallel side walls 20.A, 20.B and therefore a substantially constant material thickness to facilitate the demolding process.

[0113] Since the inner sleeve 16 extends beyond the mounting surface 28 along the axis x, the axial length l of the outer sleeve 24 is less than the overall axial length L. The blades 20 therefore transition conically from the inner sleeve 16 to the outer sleeve 24.

[0114] As can be seen generally from Figures 13 to 15, the blade 20 has a course E, which, or a corresponding line, runs parallel to the axis x. Between the axis x and the course E there is a so-called zero angle.

[0115] 16 and 17 show a fourth embodiment of an anti-vibration bracket 2'''. To avoid repetition, only the differences between Figures 16 and 17 on the one hand and Figures 11 to 15 on the other hand will be described.

[0116] The bushing 6''' includes a core member 7 disposed within the through bore 30 and extending along the axis x. The core member 7 is a separate component from the spring member 9 and has a hollow cylindrical shape and function. The sleeve 18 is retained within a through bore 34 formed in the core member 7 of the bushing 6'''. In some embodiments, the sleeve 18 can be glued to the core member 7, while in other embodiments, the sleeve 18 can be removable and retained by a friction fit. The inner sleeve 16 can rest against, and is preferably rigidly coupled to, the outer circumferential side of the core member 7.

[0117] As can be seen, the outer structure 22 has longitudinal ribs 36 extending along the axis x on its outer periphery, and the through holes 8 of the bracket body 4 have corresponding longitudinal grooves 38 for the respective longitudinal ribs 36. Furthermore, the core member 7 has longitudinal ribs 40 on its outer periphery extending along the axis x, and the through holes 30 have corresponding longitudinal grooves 42 for the respective longitudinal ribs 40.

[0118] While at least one exemplary embodiment has been presented in the foregoing summary and detailed description, as well as in the claims, it should be understood that a vast number of variations exist. It should also be understood that the one or more exemplary embodiments are merely illustrative and are not intended to be limiting in scope, applicability, or configuration. Rather, the foregoing summary and detailed description are intended to provide those skilled in the art with a convenient road map for implementing at least one exemplary embodiment, and it should be understood that various changes may be made in the function and arrangement of elements described in the exemplary embodiment without departing from the scope set forth in the appended claims and their legal equivalents.

[0119] Any feature disclosed in the claims, the specification, and the drawings, including structural details, relative positioning, or method steps, may be relevant to the present invention alone or in any meaningful combination with any other feature(s).

[0120] To avoid repetition, features disclosed according to the bushing / bracket should be considered as disclosed and claimable according to the method. Similarly, features disclosed according to the method should be considered as disclosed and claimable according to the bushing / bracket. The disclosed method can produce the disclosed bushing and / or the disclosed bracket. [Explanation of symbols]

[0121] 2,2',2'',2''' Anti-vibration bracket 4 Bracket body 6, 6', 6'', 6'' Bush 7 Core Members 8 Through holes 9 Spring members 10 Mounting hole 12 Lining 14 Reinforcing rib 16 Inner Sleeve 18 Sleeve 20 Blades 20.1, 20.2 Connections 20.3 Middle Section 20.A,20.B Side wall 21 Connection structure 22 Outer structure 24 Outer sleeve 26 Mounting surface 28 Mounting surface 30 Through hole 32 Blade set 34 Through hole 36 Vertical ribs 38 Vertical groove 40 Vertical ribs 42 Vertical groove B Tilt angle C radial angle d Outside diameter of inner sleeve D Inner diameter of outer sleeve E-Course G Distance between inner and outer sleeve l Axial length of mounting surface L Overall axial length of bush Pitch S Path length U circumferential angle x-axis

Claims

1. 1. A bush for an anti-vibration bracket (2; 2'; 2''; 2'''), the bush (6; 6'; 6''; 6''') comprising an outer structure (20, 24) and an inner sleeve (16), the outer structure (20, 24) comprising a connection structure (21) connected to the inner sleeve (16), the outer structure (22) designed to connect to an opening (8) of the anti-vibration bracket (2; 2'; 2''; 2'''), the inner sleeve (16) comprising a through hole (30) adapted to connect at least partially to a tubular member (18), the connection structure (20; 20, 32) being made from a thermoplastic elastomer (TPE).

2. 2. The bushing of claim 1, wherein the outer structure (22) comprises an outer sleeve (24), and the connecting structure (21) is connected to the outer sleeve (24).

3. The bushing of claim 2, wherein the inner sleeve (16) and / or the outer sleeve (24) are made from a second plastic material.

4. 3. The bush according to claim 1 or 2, wherein the bush (6; 6'; 6''; 6''') is entirely made of TPE or the spring element (9) of the bush (6; 6'; 6''; 6''') is made of TPE.

5. The bushing according to any one of the preceding claims, wherein the connection structure (21) comprises at least two blades (20) connecting the outer structure (20, 24) and the inner sleeve (16).

6. 6. The bushing according to claim 5, wherein the at least two blades (20) have a structure (20, 24) that extends helically with respect to the axis (x) of the through hole (30), the blades (20) being evenly distributed in the circumferential direction of the inner sleeve (16).

7. 7. A bush according to claim 5 or claim 6, wherein said at least two blades (20) have a curved cross-sectional shape with essentially parallel side walls (20.A, 20.B) over at least 50% of their extension path.

8. 8. A bush according to any one of claims 5 to 7, wherein the at least two blades (20) have a pitch (P) in the range of 30 mm to 300 mm and / or cover an inclination angle (B) of 0° to 80°, in particular 1° to 80°, in particular 10° to 50° and / or have a path length (S) of at least 1.1 times the distance (G) between the inner sleeve (16) and the outer sleeve (24) or between the inner sleeve and an opening in the anti-vibration bracket (2; 2'; 2''; 2''').

9. A bushing according to any one of claims 5 to 8, wherein the number of blades (20) is between 2 and 12.

10. 10. The bushing of claim 5, wherein the at least two blades (20) are evenly distributed around the circumference of the inner sleeve (16) or the blades (20) are unevenly distributed around the circumference of the inner sleeve (16).

11. A bush according to any one of claims 5 to 10, wherein the at least two blades (20) have a smooth transition (20.1, 20.2) to the outer sleeve (24) and / or to the inner sleeve (16).

12. 12. An anti-vibration bracket comprising a bracket body (4) comprising an opening (8) for a bushing (6; 6'; 6''; 6''') according to any one of claims 1 to 11, said bushing (6; 6'; 6''; 6''') being connected to said opening (8) via said outer structure (22).

13. An anti-vibration bracket according to claim 12, wherein the bush (6; 6'; 6''; 6''') is manufactured by overmolding the bracket body (4).

14. An anti-vibration bracket according to claim 12 or 13, wherein the bracket body (4) comprises a mounting structure (10) for mounting the bracket (2; 2'; 2''; 2''') to an object.

15. A method for manufacturing an anti-vibration bracket (2; 2'; 2"; 2'") according to any one of claims 12 to 14, comprising the steps of placing the bracket body (4) in an injection mould, overmolding the bracket body (4) with a thermoplastic elastomer (TPE) to form the bush (6; 6'; 6") or a spring element (9) of the bush (6; 6'; 6"; 6"'), and demolding the bracket (2; 2'; 2"; 2'") after the thermoplastic material has sufficiently hardened.

16. A method for manufacturing an anti-vibration bracket (2; 2'; 2"; 2'") according to any one of claims 12 to 14, comprising: providing a two-component injection mould; injecting a first plastic material to form the bracket body (4); allowing the first plastic material to fully harden; overmolding the bracket body (4) with a thermoplastic elastomer (TPE) to form the bushing (6; 6'; 6"; 6'") or the spring element (9) of the bushing (6; 6'; 6"; 6'"); and demolding the bracket (2; 2'; 2"; 2'") after the thermoplastic material forming the bushing (6; 6'; 6"; 6'") or the spring element (9) of the bushing (6; 6'; 6"; 6'") has fully hardened.

17. 17. The method according to claim 15 or 16, wherein the inner form forming the blade (20) of the bush (6; 6'; 6''; 6''') is deformed using a spring and a spiral guide groove which guides the inner form.

Images