TW201231314A - Novel type of construction for passenger car/commercial vehicle lightweight chamber-type rims comprising type of construction, material concept, structural features and production method - Google Patents

Abstract

Rotating wheel masses have a major influence upon the acceleration power of passenger cars and commercial vehicles. In order to reduce CO2 emissions and fuel consumption, rims are made available which are lighter than currently conventional sheet-steel or cast-aluminium versions. In this case, in addition to the reduction in weight, a reduction in the moment of inertia is also achieved. In electric vehicles, when lightweight rims are used, the battery can be made smaller, lighter and more cost-effective for the same operating range. If the battery size is the same, the operating range increases.

Description

201231314 VI. Description of the invention: [Technical field to which the invention belongs] The quality of the rotating wheel has a significant impact on the acceleration power of passenger cars and commercial vehicles. In order to reduce CO2 emissions and fuel consumption, rims have been provided that are lighter than conventional steel sheets or cast aluminum wheels. In this case, in addition to reducing the weight, the moment of inertia is also reduced. In electric vehicles, battery packs with the same operating range when using lightweight rims can be made smaller, lighter and more cost effective. If the battery pack is the same size, the operating range is increased. [Prior Art] Automobile wheels are usually composed of rolled steel. Weight reduction can sometimes be achieved with rim geometry. However, even the optimized geometry still has a relatively heavy weight. In addition, rims composed of lighter materials such as aluminum or composite fiber materials (especially those based on Kevlar or carbon) have been established in recent years. However, in the case of such materials with lower stability of the particles, the geometry of the rim is limited and relatively high quality is often used to ensure minimum stability. This is extremely important for the new lightweight rims of the automotive industry. Known techniques are used to make such wheel rims having U-shaped spokes made of lightweight metal as described in DE 401 3603. The disadvantage of these rims is that due to the -u shape, it is necessary to accept that the spokes have a larger wall thickness and therefore are heavier. DE 102 28 052 discloses lightweight rims made of lightweight metal, the parts of which contain a blended textile material. These systems are also lighter than straight aluminum wheels -5 - 201231314. However, the weight of these rims is reduced. DE 1 0 2005 04 1 94〇 describes a lightweight rim consisting entirely or mostly of a textile-reinforced matrix material, that is to say a textile/resin hybrid system. These rims must have a corresponding large wall thickness to ensure the required stability. However, the greater the amount of material required for this purpose, will result in a considerable minimum weight of such rims. Further developments of these rims are disclosed in the optimized system of DE 10 2007 (Η5 108», which is partly manufactured from textile hoses. This is accompanied by further weight reduction and improved stability. Even though these systems are re-optimized in terms of weight and stability. It is also known to use polymer foams for the manufacture of lightweight rims. In WO 2〇〇7〇35076, PU foams are used for the manufacture. A two-part elastic mold consisting of polyurethane and joining them together. The foam is then removed. The composite fiber rim is known from the free car race and motor sport. The manufacturing method is intended to be singularly manufactured and not suitable for series production of passenger/commercial wheel rims. US 6,398,313 describes a lightweight bicycle rim which is composed of a two-part composite fiber material, which is optionally along the hair The foam cores are glued together. In this case the foam material is only contained in the wheel flange, not in the spokes. DE 4010326 describes in particular the foam material for the spokeless disc wheel, such as in a racing wheel. A similar method also describes a tennis racket according to JP 05229229. A lightweight rim system for a vehicle construction filled with a polymer foam is disclosed in US 4, 03 0, 754. Only two of these rims are The wheel flange of the group of parts 201231314 is filled with the foam material. Therefore, the weight reduction is only a relatively low procedure. It is known to those skilled in the art, especially in car rims, which are the weight of the spokes. Most of them. However, especially since the spokes are critical to the stability of the rim and therefore extremely important for the safety of the car, it is almost impossible to reduce the weight according to the prior art. Furthermore, the last mentioned system has a pair of stability. Disadvantages of joint elements or joints that have a negative impact (especially lateral loads, such as lateral loads occurring during bending). SUMMARY OF THE INVENTION In the context of the prior art, the object of the present invention is to produce weight and durability. A novel lightweight rim of improved combination of properties and strength or stability. Furthermore, the object of the invention is to produce a lightweight rim without joint elements or joints Further, the object of the present invention is to produce a lightweight rim having a material complication that allows for a high degree of freedom in the configuration of the rim shape. Further, the object is to make it possible to manufacture a very light and good durability. Construction and manufacturing methods for quality rims with a cycle time of less than 1 〇 minutes and most automated methods. Solutions These are the new types of construction and manufacture of lightweight rims for passenger cars/commercial vehicles. Acquired. These novel lightweight chamber rims are constructed in a similar manner to the conventional rims of the wheel 201231314 and the rim rim that accommodates the hub. The lightweight rim of the present invention is unique in that it is a special material. In particular, these objects are achieved by means of a novel lightweight rim consisting of a rim groove and a rim star with a hub. The rim groove and the rim star each comprise, according to the invention, an outer region and an inner region surrounded by the outer region on at least three sides of the four sides. The outer region is made from a reinforced hybrid material containing a reinforcing material and a matrix material. The inner region, which has been described above as being surrounded by the mixed material on at least three sides of the four sides, is composed of a core material which is a foamed polymer. In a preferred embodiment, the core material is entirely surrounded by the blended material on all four sides. In a second alternative embodiment, three of the four sides of the core material are surrounded by the hybrid material, and as the fourth side, the inside of the wheel is not surrounded by the hybrid material, but is coated with a protective layer such as, for example Glued protective film. Therefore, this is a U-shaped profile of the core material. In an alternative embodiment, the inner side may additionally be coated with a thermally reflective layer', for example in the form of a glued metal foil. In this second embodiment, the metal foil may be the same as the protective layer. [Embodiment] Wheel groove The wheel groove of the present invention is composed of a reinforced mixed material. The strengthening material used is carbon fiber, aromatic polyamide fiber or glass fiber. The fibers can be present unidirectionally in a braid, mat or bonded web. The fiber portion amounts to between 30 and 70% by volume of the volume of the mixed material, preferably between 50 and 65 201231314% by volume. The matrix material used was an epoxy resin. The epoxy resin blend was set to have a viscosity of 10 to 2000 mPa*s at 23 °C. The wall thickness can be between 2 and 20 mm, preferably between 2 and 10 mm. One or more continuous chambers are provided in the rim groove. These chambers are used for stiffening and at the same time to reduce the amount of composite fiber required, thus reducing the weight of the rim. In order to transfer shear and compressive forces, the chambers are completely filled with core material. The core material has a density of 25 to 200 kg/m2, preferably a density of between 51 and 71 kg/m3. The compressive strength amounts to 0.3 to 1 MPa. The shear strength is in the range of 〇.3 to 6.0 MPa. A polymer foam such as a polyurethane, a polymethyl methacrylate (PMMA) or a poly(meth) acrylamide (PMI) foaming system is used as a core material. It is preferred to use a PMMA or PMI foam. A rim star having a hub The rim star and the reinforcing material and matrix material of the hub housed therein correspond to the reinforcing material or matrix material of the rim groove. This applies to the fibrous material, the form of the fibrous material, and the epoxy resin. Regardless of the design, the rim star is made in a sandwich configuration. The rim design may comprise single or multiple spokes and a disc shape with or without cooling air holes. Thus all conventional rim designs can be implemented using the structure of the present invention. The cross-section of the spokes or discs is accomplished with an outer composite fiber layer and a foam core positioned therebetween. This configuration is similar to the configuration of the rim groove. The hub consists of a center and a bore for fastening the wheel. Fastening the wheel -9- 201231314 is usually carried out using bolts or screws. The center and the bores can be made with or without metal inserts. The chamber between the bore and the center is completely filled with the core of the foam according to the statement about the rim groove. The rim star can have a variety of different shapes. In addition to the disc, a rim star having one, two, three, four, five or more cut portions can be manufactured. It is therefore possible to implement a rim having a plurality of wide spokes. The spokes can then be closed outwards or U-shaped, that is to say hollow towards the interior of the vehicle. Other shapes, such as an X-shaped cross section, are also foreseen. It is preferred to have a rim star with spokes between 3 and 12. It is especially preferred to have a rim star with spokes between 3 and 7. The spokes preferably have a chamber profile or a U-profile. Core material The core material is a polymer foam. The core material is preferably a PMMA or PMI foam, preferably a PMI foam, such as available from Evonik R6hm, for example under the trade name ROHACELL®. The composition and manufacture of such PMI foams can be found in EP 0 874 01 9 , EP 1 44 4 293 or EP 1 678 2 44. These PMI foams are usually foamed crosslinked materials which are produced from a mixture containing (meth)acrylic acid, (meth)acrylonitrile, a crosslinking agent, a foaming agent, and a polymerization initiator. The blend (meth)acrylic acid herein represents methacrylic acid, acrylic acid or a mixture of the two. The blend (meth)acrylonitrile represents methyl acrylonitrile, acrylonitrile or a mixture of the two. The PMMA foam is correspondingly a foamed PMMA molding compound. -10- 201231314 An important embodiment of the invention is that the polymer foaming system has a closed cell material. This is especially the case for the listed PMMA and PMI foams. Closing the holes prevents epoxy from passing through the foam core. Thus, when the reinforcing material is impregnated, the epoxy resin does not penetrate the foam core and maintains a low density inside the rim. It is even desirable that the surface layer penetrates the opening hole on the surface of the surface, which is caused by the rim. The rim can additionally have an aluminum or iron ring that surrounds the tread. This reinforcement prevents the tire from being directed downwards when most of the metal elements are directed directly to the rim or the rim is damaged during operation. The rim of the present invention has a number of advantages: • Non-lightweight, significantly better than steel, aluminum Or a single layer composite fiber solution is light. The weight optimized chamber cross section of the rim groove and the sandwich construction of the hub rim star provide a combination of weight and strength that is significantly improved over the prior art. • The moment of inertia is reduced by more than 5〇%, which, with the use of conventional drives, allows a significant reduction in the CO2 emissions and fuel consumption of the vehicle. • In electric vehicles, the energy consumption is correspondingly reduced. There is also the possibility of reducing current costs or extending range. • The rim of the rim can be dispensed with. Therefore, co2 emissions during lacquering and lacquer drying are also eliminated. • The rim of the present invention exhibits particularly good weatherability and corrosion without moisture or deicing salts. • The rim is manufactured with a standardized fastening system and can therefore be used in novel cars

S • 11 - 201231314 and for the service department. Therefore, the rims can be transferred without being converted into existing wheel suspensions. • In the modified state, the same reduction in co2 as in the case of a novel vehicle is achieved. • In the crash/collision performance, damage to the composite fiber structure in the form of a crack must initially be assumed. However, significant breakage is not expected (such as occurs in cast aluminum rims). In lightweight chamber rims, air escape from the interior of the tire occurs slowly and allows the driver to react to avoid accidents. A similar type of damage to the aluminum rim typically causes the major portion of the rim flange to rupture, with the tire suddenly losing pressure. This type of damage often overloads the auxiliary system and the driver at high speeds. Therefore, the rim of the present invention contributes to improving road traffic safety. The novel method for making the above described lightweight rim is also an integral part of the invention. In this case, the manufacturing method for manufacturing the rim groove, the rim star and the hub, and the complete rim includes the steps of manufacturing the core, manufacturing the reinforced material blank, and fabricating the finished rim portion. Manufacturing Core The starting material for the core is a blank cut from a foam sheet or a foamed formed PMMA or PMI blank. In this case, the forming can be carried out by sawing, honing or a combination of sawing and honing. Alternatively, or as an additional processing step, thermoforming can also be used. In this case, the billet is heated and then shaped and cooled in a suitable mold. The forming in this case is carried out, for example, by bending, rolling or pressing. -12- 201231314 In a preferred embodiment, the starting material is roughly unfoamed semi-finished product of at least one blowing agent. The plurality or more of the polymeric blank is positioned in two or more portions of the mold and heated to a specific foaming temperature of the material. Fill the chamber of the mold. Removal of the reinforcing material blank after the mold is opened will be used to fabricate the fibers contained in the rim groove, the rim star and the material into a woven fabric, a woven mesh, a knitted fabric or a material. These have in this case a shape corresponding to the latter rim groove or ring star. The finished rim portion is applied as a surface finish by coating the molder's rim for the finished rim portion. To produce the desired structure, for example, in the first operation, the mold surface can be applied to a solar and weather resistant layer of 100 μηι. For this purpose, such as spraying. This layer may be transparent or colored or have a metallic effect to provide an additive to the layer to achieve scratch resistance, additional UV or or anti-stain properties. This actual manufacturing method is carried out in the first method step by introducing the billet and the core into the rim manufacturing mold. The two portions, which are composed of the bottom surface of the mold and which are composed of the mold cover, are formed to contain the polymer blank. Close the core of the foam and finish the core. The blend in the hub. The wound fiber embryo has a wheel of the hub, which can add a thickness of 10 to the color and surface. The method can be exemplified. In addition, the weathering protection and/or the reinforced material mold are preferably presented, and have a mold segment that can be moved radially outside the other. For this purpose, one or more parts of the reinforcing material blank and core are introduced, covered and finally positioned. In order to ensure dimensional stability, the adhesion of the reinforcing material blank and the core can be locally performed during the manufacturing process. In the second method step, the mold is adjusted and closed. The mold can be preheated as early as during the introduction operation to the temperature at which the epoxy resin blend is cured after setting the tip. After introducing, draping, and positioning all components, close the mold. The force to maintain the closure is produced by a press or by mechanical clamps of the upper and lower mold halves. Resin injection constitutes the third method step. After closing two or more parts of the mold, an epoxy resin system composed of a mixture of an epoxy resin (component A) and an aminic hardener component (component B) is injected under pressure into the mold. . Component A in this case often consists of a mixture of components having an OH group such as, for example, bisphenol A, and a component having an oxirane group such as, for example, epichlorohydrin. Component B often contains an acid anhydride, a diamine or a triamine. The composition of the epoxy resin is generally known in the prior art and can be found, for example, in H.-G. Elias, Macromolecules (Vol. 1-4, Wiley-VCH, Weinheim, 6th edition, 1 999-2003). When the resin wets the preheated mold, it begins to solidify rapidly. The formulation and viscosity of the resin, along with the hardener system, injection pressure, mold internal pressure, mold internal temperature, and cure time, are method parameters that are optimized for the particular application. If appropriate, 'injection can occur simultaneously at a plurality of points; thus the best possible distribution of the resin is obtained. Preferably, the epoxy resins are thermoset systems having a heat resistant temperature of at least 200 °C. -14- 201231314 After curing 'Removal of the finished rim in the fourth method step. After removal, the possible flaws at the injection or exhaust point of the rim are removed by cutting and/or polishing. Optionally, the rim may be degreased and lacquered, especially when there is no prior internal coating of the mold. In this case, a protective coating, a lacquer layer and/or a clear coating can be applied. The coating can be carried out by spraying, dip coating or powder coating. In a preferred embodiment, the rim is made in one piece. This means that in the method step, the mold of the rim (including the rim groove, the rim star and the hub) is lined with a reinforcing material blank and a foam core material. In another less preferred embodiment, the various rim components (e.g., rim groove and rim star) are fabricated independently of each other and later joined to each other, e.g., by adhesive bonding. However, 'such a process' will form a rim with a contact 0. Another alternative example that can be foreseen in the preferred manufacture of a one-piece rim is the 'reinforced material blank and/or the foam core. The rim groove and the rim star are formed differently. The method of the invention makes it possible to carry out material changes in different zones during the lining of the mould. The automation of steps 1 through 4 provides repeatable, uniform component quality. In addition, high efficiency cycle times of less than 1 minute are also possible. The following examples are presented to illustrate the invention more clearly, but are not intended to limit the invention to the features disclosed herein. EXAMPLES This reference and thus the comparative example of the examples of this example are the rear wheels manufactured by the series of Lotus Exige -15-201231314. This refers to the shape, diameter and width of the rim. The reference rim of Comparative Example 1 was made of pure aluminum. The rim of Comparative Example 2 was made of a carbon fiber/epoxy resin composite (hereinafter abbreviated as CF-EP) similar to the embodiment and having a solid spoke profile. Example 1 constitutes the chamber profile of the suffocating foam material. Example 2 is an inward open U-shaped profile 〇 The following results were determined in the simulation calculation. Regarding the calculation parameters, the following assumptions are made: • The maximum lateral force and braking force that occur are the same depending on the coefficient of friction between the road and the tire. The cross-section of the wheel is sized such that the bending stress is the same under the maximum lateral force and braking force. In this case, the braking force B is distributed toward all the spokes and the lateral force Q is distributed only to the spokes of 6 〇 %. • Braking moment “Mb” (wheel) = braking force X-wheel radius • The sum of the tangent forces of the spokes is “B” is the radius of the force introduced into the groove, and is: Mb/force introduction radius – • Force introduction radius Rim groove "ru" = clamp radius + spoke length • The spoke system is calculated as a spring beam, the clamp is in the hub • B is tangentially acting in the circumferential direction, Q is orthogonal to the spoke, forming lateral lateral deflection, Like the force of the rim groove • Bending length = spoke length • Beam cross section is the cross section at the clamp (bxt) • The beam cross section is constant-16- 201231314 • The point of the highest load is the clamp • Calculate the reference and compound variants according to the same principle. For the comparative example, compare the two commercially available systems to each other. This also provides dimensions for the model calculations of Comparative Example 1 and Examples 1 and 2: Table 1 Automotive Model Lotus Exige 2008 Rim Lotus Pro Race 1.2 Tire A048 LTS (90W) ASPIRE (91W) Rim Weight 7.9 kg 8.8 kg Tire Width 225 mm H/W 45 Rim radius 215.9 mm Rim width 190.5 mm Tire height 101.25 mm Wheel radius 317.2 mm Wheel circumference 1992 mm Maximum wheel load 372 kg Maximum braking and lateral force 4378 N Hub diameter (clamp for this object) Point) 170 mm Clamp radius 95 mm Spoke length "I" 100 mm Number of spokes 12 b (plier point of spoke) 22 mm t (clamp point) 25 mm F (traverse area: Σ clamp point) 6600 mm2 For better calculations, alternative models are built on the basis of these real rims. This is the rim of five spokes with the same sum of the same spoke cross section. -17- 201231314 Table 2

Number of spokes 5 b (clamp point of spokes) 52.8 mm t (clamp point) 25 mm F (traverse area: Σ clamp point) 6600 mm2 This forms the following parameters: Mb 1388 Nm ru 195 mm Sum B 7120 NB/ Spokes 1424 N present hypothetical characteristics of such materials as follows: Table 3 CF-EP-MG9 CF-EP with 60% by volume of fiber; woven fabric 90 & 45° tensile strength (δ) 20 kg /mm2 or 196 N/mm2 705 N/mm2 Elongation at break 1-3% nd Elastic modulus (Ε) 75 000 N/mm2 74 000 N/mm2 Density (9) 2.7 g/cm3 1.5 g/cm3 The following relationship is used For calculating the braking force in the case of a solid profile, for the sake of clarity, this example refers to Figures 2 to 4.

Jx = t*b3/12 moment of inertia [mm4]

Wx = t*b2/6 Section modulus (mm3) δ = Β*Ι/Ψχ Tensile strength [N/mm2] f=B*I3/ ( E*J*3 ) Bending [mm] Room contour: (d = wall thickness in mm)

Jx= ( t*b3- ( ( t-2d) * ( b-2d) 3) /12 -18 - 201231314 wx= ( t*b3- ( ( t-2d ) * ( b-2d) 3 ) /6b δ = Β *I/WX f=B*I3/ ( E"*3) The following formula is used for U-shaped contours:

Jx= ( t*b3- ( ( t-d ) * ( b-2d ) 3 ) /12

Wx= ( t*b3- ( ( td) * ( b-2d) 3 ) /6b δ = Β *I/WX f=B*I3/ ( E*J*3) The following relation is used to calculate the solid contour Lateral forces in the situation:

Jx = b*t3/12 Wx = b*t2/6 5 = Q*I/WX f=Q*I3/ ( E*J*3) The following equation is used for room contour:

Jx= ( b*t3- ( ( b-2d ) * ( t-2d) 3 ) /12

Wx= ( b*t3- ( ( b-2d ) * ( t-2d ) 3 ) /6t 5 = Q*I/WX f=Q*I3/ ( E*J*3) The following formula is used for U shape Contour: The dimension e indicates the distance between the cross sections of the contour (e 1 is from the outside and the e2 is from the inside) el= ( 2dt2+ ( b-2d ) d2/ ( 4dt + 2d ( b-2d ) ) e2 = t- e 1 Wx = Jx/e2 19- 201231314 5 = Q*i/wx f=Q*I3/ ( E*J*3) In the following model calculations, 'the size of these rims is based on the control example (C-example)丨And 2 or the embodiments 丨 and 2 are performed such that the same deformation (interpreted with the same rigidity) occurs under the same braking force and lateral force. The model calculation is made for 5 spokes. Table 4 Comparative Example 1 Comparative Example 2 Example 1 Example 2 Material • Form inscription Solid wheel gallery CF-EP Solid contour CF-EP Room contour CF-EP u-shaped contour braking force B 7120 N t 31 mm 31 mm 32 mm 32 mm b 28·5 mm 28 mm 30 mm 27 mm d - 4.5 mm 10 mm el - 15 mm e2 — — — 17 min Jx [mm2 x mm2] 59 802 56 709 54 250 51 859 wx [mm3] 4197 4051 3617 3841 δ 34 N/nun2 35 N/nrnt2 39 N/mm2 37 N/mm2 Safety against breakage 6 21 19 20 f 0.11 mm 0.11 mm 0.12 mm 0.12 mm Spoke weight 1193 g 651 g 358 g 533 g Relative to Control Example 1 100% 55% 30% 45% The "barrier safety" is based on the tensile strength of the material. Obtained from the quotient of the tensile stress under load. The corresponding calculation is also made for the transverse force Q. This leads to the following results. In this case, 値 of t, b, d, e 1 and e 2 corresponds to Table 4. Listed 値-20- 201231314 Table 5 Comparative Example 3 Comparative Example 4 Example 3 Example 4 Material, Form Aluminum Solid Profile CF-EP Solid Profile CF-EP Room Wheel Gallery CF-EP U-Shape Lateral Force Q 4378 N Jx [mm2 x min2] 70 754 69 512 60 628 62 832 Wx [mm3] 4565 4485 3789 3678 δ 32 N/mm2 33 N/mm2 39 N/mm2 40 N/mm2 Safety against breakage 6 23 19 19 f 0.09 Mm 0.09 mm 0.11 mm 0.10 mm As can be seen from the examples, with the material of the present invention, it is possible to construct a rim which has the same rigidity but is unique in that it significantly reduces the weight and at the same time has a significantly improved safety against fracture. The figures are used to illustrate the embodiments. [Simplified illustration of the drawing] Figure 1 Rim of the horizontal format Figure 2 Schematic description of the solid outline Figure 3 Graphical illustration of the outline of the room Figure 4 Schematic description of the U-shaped outline [Key component symbol description] 1 : Rim flange 2 : Wheel Ring groove 3 · Wheel width-21 - 201231314 4 : Wheel size 5 : Center 6: Reaction force axis (lateral force and B diagonal line) 7 : Clamp of the hub cross section of the solid flange spoke aluminum [bxt] 8 : Lateral force, introduction of rim groove braking force, orthogonal 9: press-in depth 10: spoke, contour depth t B : braking force Q: lateral force t: clamp point b: wheel clamp point -22-

Claims (1)

201231314 VII. Patent application scope: 1. A lightweight rim of a car wheel, consisting of a rim well and a rim star with a hub, characterized by the rim groove And the rim star is composed of a reinforced mixed material containing a reinforcing material and a matrix material in each of the outer regions, and the rim groove and the rim star are at least three sides of the four sides. The core material consisting of a foamed polymer in the inner region surrounded by the mixed material. 2. A lightweight rim according to claim 1 wherein the four sides of the core material are surrounded by the mixed material. 3. The lightweight rim of claim 1, wherein the three sides of the core material are surrounded by the mixed material, the fourth side of which is the inner side of the wheel, and the inner side of the wheel is provided with a protective layer. 4. A lightweight rim according to any one of claims 1 to 3 wherein the inner side of the wheel is provided with a heat reflective metal layer. 5- Lightweight rim according to any one of claims 1 to 3 wherein the matrix material is an epoxy resin and the reinforcing material is a braid composed of carbon fiber, aromatic polyamide fiber or glass fiber. , combined with mesh, knitted fabric or woven fiber blank. 6- The lightweight rim of claim 5, wherein the epoxy has a viscosity of between 10 and 2000 mPa*s at 23 °C prior to curing. 7- A lightweight rim according to any one of claims 1 to 3, wherein the core material is poly(meth) acrylimide or PMMA foam 〇S -23- 201231314 8. The lightweight rim of the seventh item of the patent, wherein the core material has a density between 25 and 200 kg/m3, a compressive strength between 〇3 and 1〇.〇MPa, and a shear strength of 0.3 Between 6·〇Mpa. 9. The lightweight rim of any one of claims 1 to 3 wherein the rim star has between 3 and 12 spokes. 1) A lightweight rim according to claim 9 wherein the spokes have a chamber profile or a U-profile. 1 1 The lightweight rim of any one of claims 1 to 3 wherein the lightweight rim is made in one piece and has no joints or sticking points. 1 2 - A method for manufacturing a lightweight rim according to any one of claims 1 to 11 characterized in that in the first method step, the reinforcing material blank and the core material are introduced into the performance wheel a mold of the circle; in the second method step, 'adjusting the introduced material' to close the mold and preheating to the curing temperature of the matrix material; in the third method step, injecting a mixture of the crude resin and the hardener mixture a mold in which the mixture is solidified' subsequently cooling the finished rim; and in a fourth method step, the rim consisting of the rim groove and the rim star having the hub is removed from the mold . 13. The method of claim 12, wherein the matrix material is an epoxide, the reinforced material is a woven fabric, a bonded web, a knitted fabric or a entangled fiber composed of carbon fiber, aromatic polyamide fiber or glass fiber. A billet, and the core material is a poly(meth)acrylonitrile imine or a PMMA foam. 14. The method of claim 12, wherein the coating formulation is injected into the mold prior to the first method step of -24-201231314. 15. The method of claim 12, wherein after removing the rim, the raft that may be present on the rim is removed and the rim is subsequently polished, degreased and lacquered. -25-