Bicycle frame and method for producing a bicycle frame

Abstract

The invention relates to a bicycle frame (1) which is made at least predominantly of thermoplastic material, comprising a plurality of node elements (2) and a plurality of frame struts (3) extending between node elements (2), wherein at least some of the frame struts (3) are designed as frame tubes with a preferably continuous hollow profile cross-section, wherein the frame struts (3) and the node elements (2) are joined as separately manufactured modules to form a one-piece frame, wherein at least one node element (2) is preferably made in one piece at least predominantly of a thermoplastic material and at least some of the frame struts (3) comprise a thermoplastic material reinforced with tensile long fibers. The invention further relates to a method for producing the bicycle frame (1).

Description

[0001] The invention relates to a bicycle frame which is made at least predominantly of thermoplastic material.

[0002] When manufacturing bicycle frames, the ratio of weight to stiffness is a particularly important criterion. It is generally known to manufacture bicycle frames from steel, aluminum, titanium, or carbon composite materials. Carbon bicycle frames, in particular, have established themselves in the market because carbon fibers have particularly high tensile strength and can be combined with epoxy resin to create particularly light and stiff bicycle frames. Temperature-curable plastics, particularly epoxy resin, are largely used as matrix materials. The fibers used in the prior art are usually glued together as woven or non-woven fabrics according to a predetermined cut and then inserted into a tool by hand. For example, an epoxy resin-based plastic is introduced into the closed tool in such a way that the resin penetrates the woven or non-woven fiber fabrics.The component is then cured by heat. This manufacturing process is complex and requires a high degree of craftsmanship, both prior to forming the component and in the necessary post-processing.

[0003] The manufacture of bicycle components, and in particular bicycle frames, from thermoplastics is also generally known. Thermoplastics are easier to mold than thermoset plastics. Thermoplastics are, in particular, easier to recycle and offer overall advantages in terms of manufacturing costs.

[0004] Compared to steel, aluminum, and other materials, thermoplastics are less rigid as a material for bicycle frames. Their modulus of elasticity is lower than that of steel and aluminum. Likewise, their dimensional rigidity is lower.

[0005] A bicycle frame made of thermoplastic material is described, for example, in DE 20 2022 102 923 U1. This publication essentially relates to a main frame manufactured from a thermoplastic material in a closed molding tool. The bicycle frame described in this publication is characterized in particular by the fact that it is designed as a one-piece hollow body with a frame wall enclosing its cavity, and that the frame wall of the hollow body is a one-piece construction produced by means of a rotational mold in an externally heatable rotational molding tool.This process has the advantage that the bicycle frame can be produced with sufficient stability at a relatively low cost and that the stability is possible in particular by creating different wall thicknesses in different frame areas, for example by applying different heat from the outside to the rotational molding tool.

[0006] However, the known method has the disadvantage that a relatively large rotary tool is required to produce a one-piece or single-piece main frame and that, consequently, different rotary tools are required to produce frames of different sizes, which requires high investment costs for series production.

[0007] DE 10 2007 036 869 A1 relates to a method for manufacturing a bicycle frame made of thermoplastic material using an injection molding process. The bicycle is assembled from a right and a left frame half. The frame halves are glued, welded, and / or screwed together. This process is complex and also requires the use of relatively large injection molds.

[0008] DE 10 2015 008 561 A1 describes a method for manufacturing a plastic frame for a two-wheeler using plastic injection molding. The frame is formed as an injection-molded hollow body by fluid injection. The plastic material used is a polyamide or polyolefin reinforced with glass fibers, carbon fibers, or natural fibers. A significant disadvantage of this process is that the wall thickness of the hollow body is difficult to control due to the nature of the process. Manufacturing by fluid injection produces uneven wall thicknesses and a substantially undefined inner surface of the hollow profiles.

[0009] The invention is based on the object of providing a bicycle frame that can be manufactured relatively easily, predominantly from thermoplastic material, and that is suitable for series production in various sizes. The bicycle frame should, in particular, have a structure that is easy to manufacture and a good weight-to-rigidity ratio. The invention is further based on the object of providing a method for manufacturing a bicycle frame from thermoplastic material that can be implemented particularly inexpensively.

[0010] The object underlying the invention is achieved by a bicycle frame having the features of claim 1 and by providing a method for producing a bicycle frame having the features of claim 21. Advantageous embodiments of the invention emerge from the subclaims, which relate to preferred embodiments of the bicycle frame and the method for producing the bicycle frame.

[0011] The term "bicycle" within the meaning of the present invention also includes electric bicycles. The bicycle frame according to the invention is primarily intended as a bicycle frame for a single-track vehicle, although the production of multi-track vehicles, such as tricycles, is not excluded.

[0012] One aspect of the invention relates to a bicycle frame which is made at least predominantly from thermoplastic material, comprising a multiplicity of node elements and a multiplicity of frame struts extending between node elements, wherein at least some of the frame struts are designed as frame tubes with a preferably continuous hollow profile cross-section, wherein the frame struts and the node elements are joined as separately manufactured modules to form a one-piece frame, wherein at least one node element is made in one piece at least predominantly from a thermoplastic material and at least some of the frame struts comprise a thermoplastic material reinforced with tensile long fibers. Preferably, several of the node elements, furthermore preferably all of the node elements, are made from a thermoplastic material. At least one of the node elements can be made from multiple parts.

[0013] The bicycle frame according to the invention is advantageously modular in design and assembled from a plurality of separately manufactured frame elements / frame components. At least some, preferably all, of the components assembled to form the bicycle frame according to the invention are made at least predominantly, preferably entirely, of thermoplastic material, thus ensuring particularly good reusability or recyclability of the bicycle frame according to the invention.

[0014] A particularly advantageous feature of the modular design of the bicycle frame is that its production from thermoplastic material eliminates the need for large injection molds, whose size is approximately the same as the frame itself. Another advantage is that the bicycle frame can be manufactured in various sizes without requiring injection molds for differently dimensioned components. This makes the bicycle frame according to the invention particularly well-suited for series production.

[0015] The bicycle frame can be joined in the classic way using frame struts or frame tubes cut to different lengths, for example in a frame jig.

[0016] Node elements in the sense of the present invention are those elements which have several Connect the struts / frame struts / rods / frame tubes of the bicycle frame. Theoretically and ideally, the frame struts are rods that absorb only normal forces whose line of action lies along the rod axis. Those skilled in the art will recognize that this approach is idealized and does not correspond to the idealized approach in practice on a bicycle frame, for example, a so-called diamond frame.

[0017] Frame struts within the meaning of the present invention can be struts that have a solid profile cross-section or that have a hollow profile cross-section. A frame tube within the meaning of the present invention is a frame strut that has at least partially, preferably completely, ie, a continuous, hollow profile cross-section.

[0018] For example, a seat stay or a chain stay can be designed as either a hollow profile or a solid profile, whereas a seat tube, a top tube or a down tube of a bicycle frame according to the present invention generally has a hollow profile cross-section, which is preferably but not necessarily continuous from end to end of the frame tube.

[0019] The frame tubes according to the present invention can have a round or square cross-section, an oval or teardrop-shaped cross-section, or combinations thereof. At least some frame tubes can have a cross-section that varies along their length. The cross-sectional profile of at least some frame tubes can be designed as an open or partially closed cross-sectional profile. If the bicycle frame according to the invention is intended for an electric bicycle, for example, at least one frame tube can have a profile cross-section that allows for the accommodation of a battery storage unit or that is at least partially designed as a battery compartment.

[0020] In a possible and expedient embodiment of the bicycle frame according to the invention, it is provided that the node elements and the frame struts are joined together in a non-destructive manner, i.e. permanently.

[0021] In an advantageous embodiment of the bicycle frame according to the invention, the frame tubes comprise wound, laid, and / or woven high-tensile long fibers embedded in a thermoplastic matrix material. The frame tubes preferably comprise wound, laid, and / or woven high-tensile continuous fibers embedded in a thermoplastic matrix material or impregnated / permeated with such a thermoplastic matrix material. The fibers can be formed, for example, in the form of stockings or tubes, in one or more layers.

[0022] The frame tubes are preferably at least partially formed in one piece, preferably with a substantially closed outer surface, and preferably seamlessly. In principle, the invention also provides for at least one frame tube to be formed in multiple parts and assembled from half-shells.

[0023] Long fibers within the meaning of the present invention are fibers with high tensile strength that have a length of greater than or equal to 50 mm up to a continuous length. In contrast, short fibers within the meaning of the present invention are fibers with high tensile strength that have a length between 0 and 50 mm.

[0024] Preferably, at least some frame struts or some frame tubes according to the invention are each formed in one piece and comprise a circumferentially, ie in the circumferential direction, closed or almost completely closed layer of a fiber fabric or fiber fabric.

[0025] In particular and preferably, the frame struts and / or frame tubes according to the invention are formed seamlessly in the circumferential direction.

[0026] In a variant of the bicycle frame according to the invention, it can be provided that at least some of the frame struts comprise unidirectionally aligned, tensile-resistant long fibers which can extend in the longitudinal direction of the frame strut and / or the frame tube.

[0027] In particular, if a frame tube with a hollow profile cross-section is provided as the frame strut, the long fibers in the tube wall can extend parallel to the longitudinal direction of the frame tube. Alternatively, the long fibers can be wound helically as continuous fibers, whereby the long fibers can be embedded in the matrix material, for example, in the form of wound strips overlapping at the edges.

[0028] The tensile long fibers can be selected from a group of fibers comprising carbon fibers, glass fibers, aramid fibers, Kevlar fibers and basalt fibers.

[0029] The node elements can be formed as injection-molded, vacuum-cast, or 3D-printed connecting elements made of thermoplastic material. The thermoplastic material of the node elements can be formed as a filled thermoplastic material, preferably as a thermoplastic material filled with short fibers.

[0030] Short fibers that can be considered are tensile fibers that are selected from a group of fibers including carbon fibers, glass fibers, aramid fibers, Kevlar fibers and basalt fibers.

[0031] The thermoplastic plastic of the node elements and / or the thermoplastic matrix material of the frame struts can be selected from a group of plastics comprising PA (polyamide), PP (polypropylene), PPA (polyphthalamide), PS (polystyrene), PE (polyethylene), ABS (acrylonitrile butadiene styrene), PC (polycarbonate), POM (polyoxymethylene), PEK (polyether ketone ketone), PEEK (polyether ether ketone), PA6 (polyamide 6), PA6.1 (polyamide 6.1), PA 12 (polyamide 12) HPPA (high-performance polyamide based on recycled material), PARA (polyarylamide), PBT (polybutylene terephthalate), PK (polyketones).

[0032] Particularly preferred is PA6 as the thermoplastic material, preferably of a single grade. The use of recycled plastics may also be considered within the scope of the present invention.

[0033] In a particularly preferred variant of the bicycle frame according to the invention, the node elements comprise extensions or pins designed as plug-in connectors, each of which is inserted into a socket end of a frame tube. The frame tubes can, for example, have a continuous hollow profile cross-section, into which a plug-in connector of a node element can be inserted at each end. However, within the scope of the invention, it can also be provided that at least some of the frame tubes or frame struts have at least one socket end with an expanded cross-section.

[0034] The extensions of the node elements are preferably adapted in cross-section to the cross-section of the frame struts in such a way that the node elements and the frame struts can be joined together to form a continuous, uninterrupted surface, preferably without visible joints. The extensions forming a plug-in end of the node elements preferably have an outer cross-section that approximately corresponds to the inner cross-section of the corresponding frame strut or frame tube at a socket end.

[0035] Preferably, the frame stays are selected from a group of frame parts / frame stays comprising a top tube, a down tube, a seat tube, chain stays and seat stays.

[0036] In a preferred variant of the bicycle frame according to the invention, a head tube is formed by a node element which connects a top tube and a down tube.

[0037] The node elements can be selected from a group of frame parts comprising a head tube connecting element, a bottom bracket connecting element, a seat tube connecting element and dropouts, which are designed, for example, to connect the chainstays and to accommodate a thru-axle for a rear wheel of a bicycle with a bicycle frame according to the invention.

[0038] In an advantageous and practical embodiment of the bicycle frame according to the invention, at least some of the node elements can have at least one passage for accommodating lines, cables, frame struts, or frame tubes. The node elements, which are preferably obtained in one piece by injection molding from thermoplastic material, preferably have dimensions that allow the production of passages using appropriately designed sliders in an injection mold.

[0039] At least one passage of at least one node element can form at least one inner joining surface that interacts with a complementarily designed joining surface of a frame strut, so that, for example, a frame strut, a frame brace, or a frame tube can pass through the respective node element. This allows for an enlarged joining surface, which is particularly advantageous when the respective node element is glued or welded to a frame brace or a frame tube.

[0040] Welding in the sense of the present invention is understood to mean a connection of the thermoplastics to be welded together, which is produced without the use of welding filler materials, by applying pressure and temperature when joining the components to be welded together, in such a way that the components enter into an intensive material connection in the sense of a molecular penetration.

[0041] Bonding or gluing in the sense of the present invention means a connection of components using an additional material or using an adhesive.

[0042] Preferably, at least one of the node elements has at least one joining surface that interacts with a complementary joining surface of a frame strut in a frictionally engaged and / or materially engaged and / or positively engaged manner. At least one node element can be completely penetrated by at least one frame tube. This can be achieved, for example, in a particularly advantageous manner by a node element designed as a seat tube connecting element having at least one passage through which a seat tube, as the frame tube, completely penetrates.

[0043] Preferably, the node elements are glued and / or welded to the frame struts. For this purpose, it can be provided, for example, that the node elements and the frame struts are made of thermoplastic materials that are compatible with each other in terms of weldability, preferably of the same type.

[0044] Preferably, the node elements are anchored to the frame struts in a form-fitting manner, preferably in a manner that ensures that the node elements and the frame struts or the frame tubes cannot be removed without causing damage.

[0045] In order to realize a positive connection between node elements and frame struts, it can be provided, for example, that the node elements have at least one extension designed as a plug-in connector with at least one locking profile, which interacts with a complementary locking profile in a receptacle designed as a sleeve or sleeve end of a frame profile.

[0046] The connector can, for example, be designed like a hose connector with a Christmas tree profile. Alternatively, the connector can have a plurality of integrally formed spring tongues that interact positively with an inner circumferential groove or undercut in a socket end of a frame tube.

[0047] Alternatively, it can be provided that the node elements or at least one node element has at least one connector comprising at least one joining surface designed for positive engagement with a preferably smooth-walled inner surface of a frame strut designed as a frame tube. For this purpose, it can be provided, for example, that the joining surface has a surface roughness, optionally by integrating an additional material, for example in the form of a granular silicate material, which is designed such that the joining surface engages positively with the smooth-walled inner surface of the frame tube.

[0048] Alternatively, it may be provided to provide a plurality of bristles or brush-shaped elements or hooks or claws in the joining surface, which are aligned in a joining direction and which, when pulled on the connection, are positioned in an opposite direction and thus prevent the connection from coming loose.

[0049] In a particularly preferred variant of the bicycle frame according to the invention, at least one lost anchoring element is provided in a joint of at least one plug-in connection between a plug-in connector of a node element and a socket end of a frame tube, wherein the anchoring element is preferably inserted at least partially into a recess of a plug-in end.

[0050] The anchoring element can be designed, for example, as a plate or ring that is loosely inserted into a correspondingly contoured recess in the joining surface of a plug end. The anchoring element can be made of thermoplastic material; alternatively, a separate anchoring element made of a metallic material can be provided. The anchoring element can comprise locking hooks, locking teeth, or locking springs that, when tension is applied to the connection, become raised and engage in a smooth-walled socket end of a frame tube.

[0051] Alternatively, it may be provided, for example, to treat at least one joining surface involved with an assembly paste before joining, which may, for example, be formed as a dispersion of a volatile carrier with corundum or silicate particles.

[0052] A further aspect of the invention relates to a method for producing a bicycle frame from thermoplastic material, preferably for producing a bicycle frame with one or more of the features described above.

[0053] The procedure includes the following steps: - Providing a plurality of frame struts which are at least partially formed as frame tubes with a hollow profile cross-section and which comprise wound, laid and / or woven tensile long fibers which are embedded in a thermoplastic matrix material, - Providing a plurality of preferably integrally formed node elements made of thermoplastic material, each of which is designed to produce a plug-in connection with the frame struts, - Joining the node elements and the frame struts to form a one-piece bicycle frame, - wherein the method comprises at least one of gluing and / or welding of the node elements to the frame struts.

[0054] Within the scope of the invention, welding of the node elements to the frame struts can be carried out as ultrasonic welding or friction welding in the region of interacting joining surfaces of the node elements and the frame struts.

[0055] Preferably, the node elements are at least glued to the frame struts.

[0056] In a particularly preferred variant of the method according to the invention, it is provided that the node elements are glued or welded to the frame struts and that, in addition, a positive anchoring is provided between the frame struts and the node elements, if necessary with the aid of additional anchoring elements.

[0057] It is particularly advantageous if the thermoplastic material of the node elements and the matrix material of the frame struts are made of thermoplastics that are compatible with each other in terms of weldability. Generally, similar thermoplastics can be welded together, whereas thermosetting plastics or elastomers cannot.

[0058] The bonding is preferably carried out using at least one adhesive selected from a group of adhesives comprising methane acid, modified polyurethane, cyanoacrylate, modified epoxy resin.

[0059] The method may further comprise the production of the node elements by injection molding, vacuum casting or 3D printing.

[0060] The node elements can, for example, be made at least partially from a thermoplastic filled with tensile short fibers.

[0061] Preferably, the thermoplastic material filled with tensile short fibers has a filling level of 20 to 60 percent by weight based on the total mass of the component or based on the total weight of the node element.

[0062] It is particularly expedient if the bicycle frame is assembled from frame struts that are cut to length from prefabricated frame components according to a predetermined frame size. The frame components can be joined to the node elements using at least one frame jig, wherein the frame struts are preferably selected from a group of frame parts comprising a top tube, a down tube, a seat tube, chainstays, and seat stays, and the node elements are selected from a group of frame parts comprising a head tube connecting element, a bottom bracket connecting element, a seat tube connecting element, and dropouts that are designed to accommodate an axle, for example a thru-axle, of a rear wheel for a bicycle.

[0063] The invention is explained below with reference to and with reference to an embodiment shown in the accompanying drawings.

[0064] They show: Fig. 1 is a schematic exploded view of a bicycle frame according to the invention, Fig. 2 a perspective exploded view of a seat tube connecting element as a node element of the bicycle frame and a seat tube of the bicycle frame as a frame strut, Fig. 3 a sectional view of a seat tube connecting element of the bicycle frame according to the invention joined to the seat tube, Fig. 4 a perspective view of a bottom bracket connecting element of the bicycle frame according to the invention before joining to the down tube of the bicycle frame, wherein the connection between the bottom bracket connecting element and the down tube is achieved by means of a lost anchoring element, Fig. 5 a further perspective view of the joined connection between the bottom bracket connecting element and the down tube according to Fig. 4, Fig. 6 a perspective exploded view of a detail from Fig. 4, Fig. 7 is an exploded perspective view of an alternative embodiment of the connection between the bottom bracket connecting element and the down tube of the bicycle frame, Fig. 8 is a perspective exploded view of a further embodiment of a bottom bracket connecting element and a complementary seat tube of the bicycle frame, Fig. 9 a sectional view of the joined connection according to Fig. 8, Fig. 10 shows a further embodiment of the bottom bracket connecting element of the bicycle frame according to the invention and Fig. 11 a sectional view of the joined connection according to Fig. 10.

[0065] First, reference is made to the Fig. 1, which shows an exploded view of the bicycle frame 1 according to the invention. Fig. 1 is of modular construction according to the invention and comprises node elements 2 which are made, for example, in one piece from injection-molded thermoplastic material and which are joined together with frame struts 3 of the bicycle frame 1 to form a one-piece structure which cannot be removed without destruction.

[0066] The node elements 2 are at least glued to the frame struts 3, wherein the frame struts 3 in the form of a top tube 4, a down tube 5, a seat tube 6, two seat stays 7, and two chain stays 8, in the described embodiment, are all designed as frame tubes with a hollow profile cross-section. The frame tubes 4, 5, 6, 7, 8 are each designed as open-ended tubes made of a fiber composite material with a hollow profile cross-section. The frame tubes 4, 5, 6, 7, 8 each comprise a fiber fabric made of high-tensile long fibers, for example, aramid fibers, consolidated with a thermoplastic matrix material.

[0067] For the production of the bicycle frame 1 according to the invention, the frame tubes 4, 5, 6, 7, 8 are provided as prefabricated, dimensionally stable components / frame elements cut to a suitable length and are joined together with the node elements 2 to form a one-piece bicycle frame 1.

[0068] The node elements 2 comprise a seat tube connecting element 9, a head tube connecting element 10, a bottom bracket connecting element 11 and two dropouts 12. The head tube connecting element 10 is designed to accommodate a headset for supporting a fork shaft of a bicycle fork (not shown) and connects the top tube 4 to the down tube 5.

[0069] The bottom bracket connecting element 11 can be designed, for example, as a motor bracket for an electric bicycle, as shown in Fig. 1. Alternatively, the bottom bracket connecting element 11 can be designed as a conventional bottom bracket shell for a non-electrically powered bicycle, as shown in the illustrations according to Fig. 4 to 11 shown.

[0070] The node elements 2 are each designed as one-piece injection-molded components made of thermoplastic material and each comprise extensions 13 designed as plug-in connectors, the outer cross section of which corresponds to the inner cross section of the frame struts 3.

[0071] In the described embodiment, some of the node elements 2, namely the head tube connecting element 10, the seat tube connecting element 9, and the bottom bracket connecting element 11, are essentially hollow, i.e., provided with passages 14 for cables, Bowden cables, or hydraulic lines. The bottom bracket connecting element 11 can be designed in a known manner as a bottom bracket shell for receiving a press sleeve for a bottom bracket.

[0072] The extensions 13 each comprise circumferential joining surfaces 15 that interact with an inner wall 16 of the frame tubes 4, 5, 6, 7, 8. In the described embodiment, the node elements 2 are glued or welded to the frame tubes 4, 5, 6, 7, 8. In some embodiments, a positive anchoring of the node elements 2 to the frame tubes 4, 5, 6, 7, 8 is additionally provided.

[0073] The dropouts 12, as node elements 2, which connect the seat stays 7 and the chain stays 8, can be designed essentially as solid profiles. These are designed to accommodate a rear wheel axle of the bicycle and to attach brake bosses, as well as at least one rear derailleur hanger or another type of attachment for a gear system.

[0074] Fig. Figure 2 shows a special embodiment of the seat tube connecting element 9 and the associated seat tube 6 according to the invention, which, unlike the other node elements 2, forms a plug-in receptacle 20 as a passage for an end 21 of the seat tube 6. The end 21 of the seat tube 6 completely penetrates the seat tube connecting element 9 such that the end of the seat tube 6 is flush with a seat post receptacle 22 of the seat tube connecting element 9.

[0075] In the illustrated embodiment of the seat tube connecting element 9, both the seat post mount 22 and the end of the seat tube 6 are slotted to allow clamping using a screw clamp. In principle, such clamping can also be achieved using invisible clamping elements. Such clamping elements are generally known in the art.

[0076] The special design of the seat tube connecting element 9 creates a particularly large and long joining surface between the outer side of the seat tube 6 and the inner side of the plug-in receptacle 20, facilitating welding and / or bonding. A seat tube clamp further contributes to the intimate connection of the components.

[0077] In the following, with reference to the Fig. 4 to 11, various possibilities for a preferably additional positive connection between the node elements 2 and the frame tubes 4, 5, 7, 8 are explained. For the sake of simplicity, the connection is explained only with reference to the bottom bracket connecting element 11. However, the explanations also apply analogously to the head tube connecting element 10, the dropouts 12, and the seat tube connecting element 9.

[0078] The Fig. 4 to 6 show a first variant of an additional positive-locking anchoring of the node elements 2 to the frame tubes 4, 5, 6, 7, 8. In this embodiment, the frame tubes 4, 5, 6, 7, 8 are all designed as hollow profiles with a smooth and non-profiled inner wall 16. In the joining surface 15 of the extension 13 of the node element 2, in the described embodiment of the bottom bracket connecting element 11, a recess 40 is provided, into which a plate-shaped anchoring element 41 is inserted. The anchoring element 41 can be designed as a metal anchoring element, but this is preferably also made of a thermoplastic material. The anchoring element 41 comprises claws 42 formed integrally and on one side, which protrude from a base plate 43 of the anchoring element 41 and are inclined in a joining direction. The recess 40 has an outer contour corresponding to the anchoring element 41.The anchoring element 41 may have been loosely inserted into the recess 40 prior to joining the bottom bracket connecting element 11 to the down tube 5. After joining, it is held in a joint between the inner wall 16 of the down tube 5 and the joining surface 15 of the extension 13. When a force is applied opposite to the joining direction, the claws 42 anchor the element to the inner wall 16 of the down tube 5.

[0079] Another variant of a form-fitting anchoring of an extension 13 of a node element 2 is shown in Fig. 7. In this variant, the joining surface 15 comprises integrally formed claws 72, which interact positively with an inner profile 73 of the down tube 5 when the bottom bracket connecting element 11 has been joined to the down tube 5.

[0080] A further variant of a positive anchoring, for example of the seat tube 6, with an extension 13 of the bottom bracket connecting element 11 pointing upwards in the installed position is shown in the Fig. 8 and Fig. 9. The respective extension 13 of the bottom bracket connecting element 11 is provided with an outer locking profile 80, which is designed, for example, in the manner of a hose connector as a Christmas tree profile and which interacts with a complementary inner profile 81 of the down tube, such as the one shown in the sectional view in Fig. 9 is shown.

[0081] Another alternative design of a positive connection between an extension 13 of the bottom bracket connecting element 11 and the down tube 5 of the bicycle frame 1 is finally shown in the Fig. 10 and Fig.11. The extension 13 comprises a plurality of circumferentially arranged spring tongues 100, which interact with the inner wall of the down tube. The elasticity and spring properties of the spring tongues 100 result from their shape and the elasticity of the thermoplastic material. The spring tongues 100 each comprise locking hooks 102 at their free ends, which cause the components to interlock. List of reference symbols 1 bicycle frame 2 node elements 3 frame struts / frame tubes 4 top tube 5 down tube 6 seat tube 7 seat stays 8 chainstays 9 Seat tube connecting element 10 Head tube connecting element 11 Bottom bracket connecting element 12 dropouts 13 appendages 14 implementations 15 joining surfaces 16 Inner wall of the frame struts / frame tubes 20 plug-in socket 21 End of the seat tube 22 Seatpost mount 40 recess 41 Anchoring element 42 claws 43 Base plate of the anchoring element 72 claws 73 Internal profiling of the down tube 80 locking profile 81 Inner profile of the down tube 100 spring tongues 102 locking hooks QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 20 2022 102 923 U1

[0005] DE 10 2007 036 869 A1

[0007] DE 10 2015 008 561 A1

[0008]

Claims

[1] Bicycle frame (1) which is made at least predominantly from a thermoplastic material, comprising a multiplicity of node elements (2) and a multiplicity of frame struts (3) extending between node elements (2), wherein at least some of the frame struts (3) are designed as frame tubes with a preferably continuous hollow profile cross-section, wherein the frame struts (3) and the node elements (2) are joined as separately manufactured modules to form a one-piece frame (1), wherein at least one node element (2) is preferably made in one piece at least predominantly from a thermoplastic material and at least some of the frame struts (3) comprise a thermoplastic material reinforced with tensile long fibers. [2] Bicycle frame (1) according to claim 1, characterized by that the node elements (2) and the frame struts (3) are not joined together in a non-destructive manner. [3] Bicycle frame (1) according to one of claims 1 or 2, characterized by that the tubes (3) comprise wound, laid and / or woven tensile long fibers which are embedded in a thermoplastic matrix material. [4] Bicycle frame (1) according to one of claims 1 to 3, characterized by that the tensile long fibers are selected from a group of fibers comprising carbon fibers, glass fibers, aramid fibers, Kevlar fibers and basalt fibers. [5] Bicycle frame (1) according to one of claims 1 to 4, characterized by that the node elements (2) are designed as injection-molded, vacuum-cast or 3-D printed connecting elements made of thermoplastic material. [6] Bicycle frame (1) according to one of claims 1 to 5, characterized by that the thermoplastic material of the node elements (2) is designed as a filled thermoplastic material, preferably as a thermoplastic material filled with tensile short fibers. [7] Bicycle frame (1) according to one of claims 1 to 6, characterized by that the thermoplastic plastic and / or the thermoplastic matrix material is selected from a group of plastics comprising PA, PP, PPA, PS, PE, PE, ABS, PC, POM, PEK, PEEK, PA6, PA6.1, HPPA, PARA, PBT, PK. [8] Bicycle frame (1) according to one of claims 1 to 7, characterized by that at least some of the node elements (2) comprise extensions (13) designed as plug-in connectors, each of which is inserted into a socket end of a frame ear (3). [9] Bicycle frame (1) according to one of claims 1 to 8, characterized by that the frame stays (3) are selected from a group of frame parts comprising a top tube (4), a down tube (5), a seat tube (6), chain stays (8) and seat stays (7). [10] Bicycle frame (1) according to one of claims 1 to 9, characterized bythat the node elements (2) are selected from a group of frame parts comprising a head tube connecting element (10), a bottom bracket connecting element (11), a seat tube connecting element (9) and dropouts (12). [11] Bicycle frame (1) according to one of claims 1 to 10, characterized by that at least some of the node elements (2) have at least one passage (14) for the passage of lines, cables, frame struts or frame tubes. [12] Bicycle frame (1) according to claim 11, characterized by that at least one passage (14) of at least one node element (2) has at least one joining surface (15) which interacts with a complementarily formed joining surface (15) of a frame strut or a frame tube (3). [13] Bicycle frame (1) according to one of claims 1 to 12, characterized by that at least one node element (2) is preferably completely penetrated by at least one frame tube (3). [14] Bicycle frame (1) according to claim 13, characterized by that a node element (2) designed as a seat tube connecting element (9) has at least one passage (14) through which a seat tube (6) as a frame tube (3) passes. [15] Bicycle frame (1) according to one of claims 1 to 14, characterized by that the node elements (2) are glued and / or welded to the frame struts (3). [16] Bicycle frame (1) according to one of claims 1 to 15, characterized by that the node elements (2) and the frame struts (3) are made of thermoplastic materials that are compatible with one another in terms of weldability, preferably of a single type. [17] Bicycle frame (1) according to one of claims 1 to 16, characterized by that the node elements (2) are anchored to the frame struts (3) in a form-fitting manner, preferably in a manner that cannot be removed without destruction. [18] Bicycle frame (1) according to one of claims 1 to 17, characterized bythat the node elements (2) have at least one extension (13) designed as a plug-in connector with at least one locking profile (80), which locking profile (80) interacts with a complementary locking profile in a receptacle designed as a sleeve or sleeve end of a frame profile. [19] Bicycle frame (1) according to one of claims 1 to 17, characterized by that the node elements (2) have at least one plug-in connector which comprises at least one joining surface (15) which is designed for positive engagement with a preferably smooth-walled inner surface of a frame strut designed as a frame tube. [20] Bicycle frame (1) according to one of claims 1 to 19, characterized byat least one lost anchoring element (41) which extends in a joint of at least one plug-in connection between a plug-in connector of a node element (2) and a socket end of a frame tube, wherein the anchoring element (41) preferably fits at least partially into a recess of a plug-in end (21). [21] Method for producing a bicycle frame (1) from thermoplastic material, preferably for producing a bicycle frame (1) with the features of at least one of claims 1 to 20, comprising the following method steps: - Providing a plurality of frame struts (3) which are at least partially designed as frame tubes with a hollow profile cross-section and which comprise wound, laid and / or woven tensile long fibers which are embedded in a thermoplastic matrix material, - Providing a plurality of preferably integrally formed node elements (2) made of thermoplastic material, each of which is designed to produce a plug-in connection with the frame struts (3) - assembling the node elements (2) and the frame struts (3) to form a one-piece bicycle frame (1), - wherein the method comprises at least one gluing and / or welding of the node elements (2) to the frame struts (3). [22] Method according to claim 21, characterized by that the welding of the node elements (2) to the frame struts (3) is carried out by ultrasonic welding or friction welding in the region of interacting joining surfaces (15) of the node elements (2) and the frame struts (3). [23] Method according to claim 22, characterized bythat the thermoplastic material of the node elements (2) and the matrix material of the frame struts (3) consist of thermoplastic materials that are compatible with one another in terms of weldability. [24] Method according to one of claims 21 to 23, characterized by the use of at least one adhesive selected from a group of adhesives comprising methane acid, modified polyurethane, cyanoacrylate, modified epoxy resin. [25] Method according to one of claims 21 to 23, characterized by that the node elements (2) and the frame struts (3) are anchored together in a form-fitting manner when joined together. [26] Method according to one of claims 21 to 25, characterized by that the method further comprises the production of the node elements (2) by injection molding, vacuum casting or 3-D printing. [27] Method according to one of claims 21 to 26, characterized bythat the node elements (2) are at least partially made of a thermoplastic material filled with tensile short fibers. [28] Method according to one of claims 21 to 27, characterized by in that the frame stays (3) are cut to length from prefabricated frame components according to a predetermined frame size and are preferably joined to the node elements (2) using at least one frame jig, wherein the frame stays (3) are selected from a group of frame parts comprising a top tube (4), a down tube (5), a seat tube (6), chain stays (8) and seat stays (7) and the node elements (2) are selected from a group of frame parts comprising a head tube connecting element (10), a bottom bracket connecting element (11), a seat tube connecting element (9) and dropouts (12).

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