Modular injection moulding tool, method for producing a structural component for a bicycle, and injection-moulded bicycle frame
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2026-02-05
- Publication Date
- 2026-08-13
Smart Images
Figure EP2026053010_13082026_PF_FP_ABST
Abstract
Description
[0001] Modular injection molding tool, method for manufacturing a structural component for a bicycle, and injection-molded bicycle frame
[0002] The invention relates to an injection mold comprising at least two complementary parent molds with interchangeable mold inserts that form an article cavity and define a negative of an article to be molded.
[0003] The invention further relates to a method for manufacturing a structural component for a bicycle from a thermoplastic material preferably reinforced with tensile-strength fibers, wherein the method comprises injection molding the structural component as a one-piece molded part in a multi-part injection molding tool which includes interchangeable mold inserts forming an article cavity.
[0004] The invention relates to a bicycle frame made of thermoplastic material.
[0005] It is known in the art to manufacture bicycle parts, especially bicycle frames, from fiber-reinforced composite materials. In the course of weight optimization for bicycles, composite components made of carbon fiber are particularly widespread. Thermosetting plastics, especially epoxy resin, are predominantly used as matrix materials. Such bicycle frames are characterized by a particularly favorable stiffness-to-weight ratio. However, they have the disadvantage that the epoxy resin-based plastic can break easily, for example, in a crash. Furthermore, the recyclability of such frames or other components based on epoxy resin is less guaranteed. The fibers used in the manufacture of carbon fiber frames are generally bonded together as woven or non-woven fabrics according to a predetermined cut and manually inserted into a mold.An epoxy resin-based plastic is introduced into the closed mold in such a way that the resin penetrates the fiber fabric or woven material. The component is then cured by applying heat. This manufacturing process is complex and requires a high degree of manual labor, both before the component is formed and in the form of the necessary finishing work.
[0006] It is still known in the art to manufacture bicycle parts, and in particular bicycle frames, from fiber-reinforced thermoplastic. Thermoplastic materials are easier to recycle than thermosetting plastics and can be molded, for example, by injection molding.
[0007] Bicycle frames made of thermoplastic materials, manufactured using injection molding, have increasingly come into focus for the bicycle industry in recent years. The classic injection molding process, and the complementary FIT (Fluid Injection Molding) process, play a crucial role in this development.
[0008] German patent DE 10 2016 015 538 A1 discloses a method for manufacturing a bicycle frame from several modules, each produced by injection molding using fluid injection technology. Fluid injection technology offers a technically advantageous way to design the individual components as hollow bodies with optimized weight. However, this method has the disadvantage that the components do not have a constant and defined wall thickness, and in particular, they do not have a consistently smooth surface within the cavities. This is not advantageous for several reasons. For example, it results in mass differences between components in a series.
[0009] One of the special characteristics of injection molding is the possibility of single-piece production, which also results in higher production speed, surface quality, and reproducibility. On the other hand, high initial investments are required for complex tooling.
[0010] Especially with bicycles, in addition to adjustable components, there are various frame sizes and versions to meet specific customer requirements. Currently, separate tool designs must be provided for all these versions and sizes, which is not economical for typical production volumes of each variant. Therefore, there is a need to manufacture as many frame variants as possible from a single basic tool design.
[0011] The invention is therefore based on the objective of providing an injection mold and a method of the type mentioned at the outset, with which one-piece injection-molded structural components, in particular bicycle frames made of thermoplastic material, can be economically mass-produced while achieving a particularly favorable stiffness-to-weight ratio with respect to the bicycle frame. The invention is particularly based on the objective of providing an injection mold that enables the production of a structural component for a bicycle, in particular a bicycle frame, in various versions and sizes, whereby as many frame variants as possible should be manufacturable from a single basic design of the mold.
[0012] The problem underlying the invention is solved by providing an injection molding tool with the features of claim 1.
[0013] The task is further solved by providing a method for manufacturing a structural component for a bicycle, in particular for manufacturing a bicycle frame.
[0014] The subject of the invention is also such a bicycle frame.
[0015] Advantageous embodiments of the invention are set out in the dependent claims.
[0016] A first aspect of the invention relates to an injection mold comprising at least two complementary master molds with interchangeable mold inserts, which form an article cavity and which define a negative of an article to be molded, and further comprising at least one mold slide, which is displaceable within the injection mold at least between a functional position and a demolding position and which, in the functional position within the closed injection mold, molds a hollow profile of the article, wherein the at least one mold slide and / or at least one mold insert are adjustable in their position and / or orientation relative to each other. The article to be produced with the injection mold is, in particular, a structural component made of thermoplastic material for a bicycle, and especially preferably a one-piece manufactured bicycle frame made of thermoplastic material.
[0017] The invention is to be understood as meaning that other complex thermoplastic hollow structures can also be produced with the injection mold according to the invention. For example, a handlebar or handlebar stem for a bicycle can be provided as a structural component, which is to be produced with different dimensions, different widths, different diameters, for example with or without backsweep or with different flares.
[0018] In the context of the invention, a functional position of a mold slide or other movable tool part refers to the position in which the thermoplastic material is injected into the closed part cavity. After the injection-molded part has been formed, the movable tool parts are moved to a position outside the part cavity to ensure the part can be demolded. This position is hereinafter referred to as the demolding position.
[0019] In the context of the present invention, an article cavity is defined as the cavity within the injection mold that forms the article, i.e., that is designed as a negative of the article. Accordingly, gates, distributors, or the like are not part of the article cavity. According to the invention, the article cavity is formed by at least several interchangeable mold inserts. In the simplest case, the article cavity can be formed by two interchangeable complementary mold inserts, one of which forms the first half and the other the second half.
[0020] The basic components of the mold preferably comprise at least one hot runner. The parts of the injection mold forming the mold can each be mounted on a carrier plate. Further carrier plates and hot runners are conceivable within the scope of the invention, particularly to enable the production of further product or frame variants, e.g., if the product is a bicycle frame, variants with and without a top tube. These are coordinated during the design process along with the mold filling.
[0021] At least one mold slide, or at least one set of slides consisting of any number of slides, is an addition to the main mold to produce the tube contours, wall thicknesses, and other undercuts of the structural component. Two large mold inserts, preferably left and right in relation to a bicycle frame and its orientation for use, can form the outer shell of a bicycle frame and thus determine its basic shape. A separation into smaller mold inserts can be achieved, for example, in the direction of the seat tube and head tube, but other configurations are also conceivable. These smaller inserts can be exchanged to adjust the size of the bicycle frame. The tube angles can thus be kept consistent. With this design, increasing the frame size diagonally, i.e., stack and reach, is possible.This is ensured in particular by the fact that the alignment of the form slides relative to the tool inserts is adjustable or changeable. This concept can be expanded by dividing the system into further form inserts.
[0022] The design of the injection mold with interchangeable mold inserts makes it possible to adapt the part cavity to different variations of a component, especially a bicycle frame, piece by piece.
[0023] According to an advantageous preferred embodiment of the injection mold according to the invention, the at least one mold slide is designed to be adjustable translationally and / or rotationally. This ensures adjustability of the mold slide with two different degrees of freedom.
[0024] One variant of the injection molding tool according to the invention is characterized in that the at least one mold slide is slidably guided in at least one holder of at least one main mold and that the at least one holder is adjustable in its position and / or orientation relative to the main mold and the mold inserts received by it.
[0025] A preferred embodiment of the injection mold according to the invention comprises at least one article cavity formed by the mold inserts with a contour corresponding to a negative of at least one main frame of a bicycle, wherein the injection mold comprises at least one first pair of slides with cooperating first and second mold slides, wherein the first and second mold slides of the first pair of slides are configured to interlock at their ends leading into the functional position in a functional position within the article cavity of the injection mold, or to bear against each other with an end face or an end profile.
[0026] The fact that at least one pair of slides interacts in such a way that the mold slides engage in a form-fitting manner within the part cavity ensures that the mold slides can withstand the injection pressure of the plasticized plastic in their functional position and are not displaced or deflected by the plasticized plastic within the cavity / partial cavities.
[0027] One embodiment of the injection mold according to the invention comprises at least a second pair of slides for forming the main frame of the bicycle, wherein the second pair of slides comprises at least a first and a second forming slide, which are configured such that the first forming slide is positively locked in the functional position by the second forming slide, which preferably extends at an angle to the first forming slide, preferably at an end leading into the functional position in the feed direction. The first and the second forming slide can extend at an angle of greater than 0° and less than 180° to each other.
[0028] A main frame of a bicycle within the meaning of the present invention is that part of the bicycle frame which comprises at least a seat tube, a bottom bracket shell or a motor bearing shell, depending on whether the bicycle is designed as an electric bicycle or as a bicycle without a motor, a down tube and a head tube. The main frame may further comprise a top tube which is connected to the head tube and the seat tube.
[0029] In a suitably designed embodiment of the injection mold according to the invention, the first mold slide of the first slide pair and the first mold slide of the second slide pair can be configured such that the first mold slide of the second slide pair passes through the first mold slide of the first slide pair and can be moved through the first mold slide of the first slide pair into its functional position, in which it preferably engages with the second mold slide of the second slide pair in a form-fitting manner. This "slide-in-slide" or "slide-through-slide" concept allows for a particularly complex design of the injection mold according to the invention to be realized in a very small space.
[0030] Advantageously, means for the adjustable alignment of at least one form slide or at least one holder of a form slide are provided, which are designed to ensure the adjustability of the holder with at least two different degrees of freedom, in particular translational and rotational.
[0031] The first degree of freedom of the at least one holder can be a division of the holder in or parallel to an adjustment direction of the mold slide, and the second degree of freedom can be a division of the holder within a parting plane of the main mold and at at least one angle with respect to the first degree of freedom, where the angle is not equal to 0°. The parting of the injection mold need not necessarily be defined by a single parting plane. In principle, the second degree of freedom can allow the holder to be adjusted linearly and, for example, transversely to the first degree of freedom. Alternatively, the second degree of freedom can allow the holder to be displaced along at least one partial circular arc.
[0032] Depending on the design of the mold inserts or the dimensions of the bicycle frame to be manufactured, it may be advantageous if at least one mold slide is modular, in particular in such a way that it has a variable or adjustable length.
[0033] In a suitably designed injection mold, at least one holder can be attached to the main mold via at least one cam guide. The cam guide can, for example, comprise at least one T-nut, preferably several T-nuts arranged in pairs and guided in at least one profile groove of a main mold.
[0034] Advantageously, at least one profile groove extends linearly or in a circular arc within a parting plane of the injection mold. The at least one profile groove can, in a known manner, have a rectangular or dovetail profile in which a T-nut with a complementary profile is guided.
[0035] Furthermore, it may be expedient to provide, alternatively or additionally, that at least one support is attached to a main form via threaded bolts, whereby the threaded bolts can pass through elongated holes in the supports.
[0036] As mentioned above, the mold components, i.e., for example, a first and a second mold, may comprise at least one hot runner and be mounted on two carrier plates that are adjustable relative to each other in an opening and closing motion. If the article is a bicycle frame, for example, a left and a right mold component may be provided, with the terms right and left referring to the operating position of the bicycle frame.
[0037] In a preferred and advantageous embodiment of the injection mold according to the invention, it can be provided that this comprises at least four, preferably five, mold slides, which partially interact in pairs, and which are selected from a group of mold slides comprising at least one head tube slide, at least one seat tube slide, at least one down tube slide and at least one rear triangle slide.
[0038] A second aspect of the invention that is eligible for protection in itself relates to a method for manufacturing a structural component for a bicycle, preferably from a thermoplastic material reinforced with tensile-strength fibers, wherein the method comprises injection molding the structural component as a one-piece molded part into a multi-part injection mold with at least one interchangeable mold inserts forming an article cavity, wherein the method is carried out using at least one mold slide which is displaceable within the injection mold at least between a functional position and a demolding position and which, in the functional position within the closed injection mold, forms a hollow profile of the article, and wherein the injection mold preferably has several of the features described above.
[0039] The method according to the invention can, for example, include the manufacture of a bicycle handlebar as a structural component, which can, for example, be extended at each end.
[0040] If the method comprises the manufacture of a one-piece bicycle frame, it can be provided according to the invention that at least some of the frame tubes, preferably at least all frame tubes of at least the main frame, are formed as continuous hollow profile sections closed at least over a partial length using a plurality of movable mold slides of the injection mold, wherein the mold slides are moved from a demolding position to a functional position within an article cavity of the injection mold and from the functional position to the demolding position.
[0041] The main frame of the bicycle frame according to the invention can, in one embodiment, include a top tube, whereas in another embodiment, the main frame can be designed without a top tube. A rear triangle is also a single component of the bicycle frame according to the invention. For the purposes of this invention, the rear triangle refers to the seat stays and chain stays of the bicycle frame. The term "chain stays" includes the corresponding structurally load-bearing elements of the bicycle frame, even in a bicycle that, for example, incorporates a belt drive. Generally, a fork is also considered a component of a bicycle frame; however, it is not the subject of this application and is not manufactured using the same tooling as the other components of the bicycle frame.
[0042] The method according to the present invention preferably comprises the one-piece production of the bicycle frame without the use of inserts. Inserts in this sense are understood to be semi-finished components lost in the injection mold, in particular made of thermoplastic material or other materials.
[0043] A particular aspect of the method according to the present invention is that preferably all frame tubes of the main frame are formed as continuous hollow profile sections closed at least over a partial length, and according to the invention these are formed exclusively by means of movable forming slides.
[0044] The method according to the invention does not require fluid injection technology or lost cores. The product or bicycle frame manufactured according to the method comprises frame tubes as hollow profile sections with a defined wall thickness and a defined, and preferably smooth-walled, inner contour.
[0045] A particular advantage of the method according to the invention is that particularly light and stable bicycle frames with a favorable weight-to-stiffness ratio and defined cross-sections and cavities can be produced by plastic injection molding.
[0046] The use of interchangeable mold inserts allows different frame sizes to be produced in a single injection mold. By adjusting the position of at least one mold slide, the mold slides can be adapted to the changing geometry of the bicycle frame.
[0047] "At least over a partial length" means, in the context of the present invention, that at least some frame tubes may have openings for the passage of cables, wires or the like, or in the form of battery compartments and / or a battery compartment cover, so that the frame tubes do not have a fully enclosed frame cross-section in the relevant areas.
[0048] The cross-section of the frame tubes can be round, oval, square, or any other desired contour.
[0049] The method for manufacturing the bicycle frame according to the invention comprises injection molding of a thermoplastic material, preferably a polyolefin.
[0050] The thermoplastic material can generally be selected from a group of plastics including PA (polyamide), PP (polypropylene), PPA (polyphthalamide), PS (polystyrene), PE (polyethylene), ABS (acrylonitrile butadiene styrene), PC (polycarbonate), POM (polyoxymethylene), PEK (polyetherketone ketone), PEEK (polyetheretherketone), PA6 (polyamide 6), PA6.1 (polyamide 6.1), PA 12 (polyamide 12), HPPA (high-performance recycled polyamide), PARA (polyarylamide), PBT (polybutylene terephthalate), and PK (polyketones).
[0051] The method according to the invention particularly preferably comprises the injection molding of a polyamide, further preferably of a polyamide 6 (PA6) or a blend of PA66+PA6I / 6T as a matrix material, wherein the injected thermoplastic material can be filled with short fibers made of a tensile-strength material.
[0052] For the purposes of this application, short fibers are defined as fibers with a length greater than 0 mm and less than 50 mm, whereas long fibers are defined as tensile-strength fibers that can have a length greater than 50 mm up to an infinite length. These tensile-strength fibers can include carbon fibers, aramid fibers, glass fibers, or basalt fibers. It is preferred that at least one frame tube is formed by means of at least two mold slides interacting in a functional position within the part cavity of the injection mold. In this way, it is possible to form relatively long frame tubes. Forming a single long cavity of a frame tube by means of at least two interacting mold slides facilitates the displacement of the mold slides from their functional position to a demolding position.Furthermore, this makes it possible to form frame tubes with an internal cross-section that varies along their length. This can be advantageous, for example, in the area of a seat tube, in order to form a section of the seat tube with a cylindrical internal cross-section. Preferably, at least one frame tube is formed with two first and second forming slides cooperating as a first slide pair, wherein the first and second forming slides of the first slide pair, in their functional position, interlock at their ends leading into the functional position within the part cavity of the injection mold or abut each other with a parting contour. Such a parting contour, as defined in the invention, can be a parting plane in which the leading ends of the forming slides abut each other in their functional position.However, a dividing contour can also be formed by mutually offset or jagged surfaces.
[0053] In a particularly advantageous embodiment of the method according to the invention, it can be provided that, for example, the first forming slide of the first pair of slides has a contour that facilitates demolding, preferably with draft angles or a conical outer contour, and that the second forming slide of the first pair of slides has a cylindrical contour. This makes it possible, for example, to produce an inner contour of a seat tube that has a cylindrical inner cross-section at least in an area intended for mounting a seat post, whereas the frame tube designed as a seat tube can open accordingly towards a bottom bracket housing or a motor bearing housing. Accordingly, in the embodiment of the method described above, it can be provided that a seat tube of the bicycle frame is formed with the first pair of slides.In this case, it is advantageous if the first forming slide of the first slide pair is used to mold a bottom bracket housing or a motor bearing housing of the bicycle frame.
[0054] In one suitable variant of the procedure, it may be provided that a seat tube of the bicycle frame is molded using the first pair of sliders.
[0055] For example, it may be intended that the first forming slide of the first pair of slides is used to mold a bottom bracket housing or a motor bearing housing of the bicycle frame.
[0056] In one variant of the method, it can be provided that a frame tube is molded with two first and second forming slides cooperating as a second slide pair, wherein a first forming slide of the second slide pair is held in the functional position, preferably at an end leading into the functional position in the feed direction, by a second forming slide of the second slide pair extending at an angle to the first forming slide.Preferably, a first short tube section of the bicycle frame, preferably as the head tube of the bicycle frame, is molded in the article cavity using the second forming slide of the second pair of slides, the second forming slide of the second pair of slides is moved into the functional position first, wherein the first forming slide of the second pair of slides molds a second long tube section of the bicycle frame, preferably as the down tube of the bicycle frame, wherein the first forming slide of the second pair of slides is moved into the functional position after the second forming slide, and wherein the first forming slide of the second pair of slides is caught at its end leading in the feed direction by the second forming slide of the second pair of slides.
[0057] It is preferably provided that the first forming slide of the second pair of slides engages positively in the second forming slide of the second pair of slides at an end leading in the feed direction in the functional position, preferably immersing itself in a catch opening of the first forming slide of the second pair of slides.
[0058] In an advantageous variant of the method, it is provided that at least two form slides penetrate each other in a functional position within the article cavity.
[0059] In order to enable the process with a relatively compact injection mold, it can be provided that the first mold slide of the second slide pair is moved into the functional position through the first mold slide of the first slide pair.
[0060] Advantageously, the thermoplastic material used in the process, which is plasticized and extruded, is filled with tensile-strength short fibers, preferably selected from a group of fibers comprising carbon fibers, glass fibers, aramid fibers, Kevlar fibers and basalt fibers.
[0061] The process can include introducing wound, laid and / or woven tensile-strength long fibers, at least in partial areas, into the article cavity, which are overmolded with a thermoplastic matrix material, preferably with a polyamide, wherein the tensile-strength long fibers are selected from a group of fibers comprising carbon fibers, glass fibers, aramid fibers, Kevlar fibers and basalt fibers.
[0062] The invention is explained below with reference to and by means of an embodiment illustrated in the drawings.
[0063] They show:
[0064] Figure 1 shows a schematic representation of the injection mold according to the invention.
[0065] Figure 2 shows a schematic representation of one side of a first variant of the injection mold with master molds designed for the production of a bicycle frame.
[0066] Figure 3 shows a view of a detail from Figure 2, illustrating the interaction of a pair of sliders in a functional position.
[0067] Figure 4 shows a schematic representation of a modularly constructed mold slide for use with the main mold of the injection mold according to Figure 2; Figure 5 shows a representation, approximately corresponding to Figure 2, of a second variant of an injection mold with main molds designed for the production of a bicycle handlebar as an article.
[0068] Figure 6 shows a schematic perspective view of a bicycle frame according to the invention and
[0069] Figure 7 shows a schematic side view of a bicycle frame in various sizes, superimposed in one illustration for illustrative purposes.
[0070] The injection mold 110, 120 according to the invention comprises carrier plates 210, 220, or mold mounting plates, each of which accommodates a mold base 310, 320. In the closed state of the injection mold 110, 120, the mold bases 310, 320 form a part cavity comprising interconnected subcavities. The carrier plates 210, 220 (mold mounting plates) are movable towards and away from each other in a known manner, in the sense of an opening and closing movement. The injection mold 110, 120 comprises a hot runner system 130, which is fed with plasticized thermoplastic material via an extruder 140.
[0071] The injection mold 110, 120 according to the invention further comprises a slide set with movable forming slides 111, 112, 113, 114, 115, 116, 121, 122, wherein the injection mold 110 shown in Figure 2 comprises two pairs of slides, each of which interacts in a functional position. The forming slides 111, 112, 113, 114, 115, 116, 121, 122 are configured to each form a hollow profile section of the article. The article cavity forms a negative of the article to be produced by the method according to the invention. The injection molding tool 110 in the variant shown in Figure 2 is designed to produce a one-piece bicycle frame 400 from a filled thermoplastic material with frame tubes 410 designed as hollow profiles and connected to each other in one piece and with a uniform material, as shown in Figures 6 and 7.
[0072] Figure 5 shows a schematic view of a second variant of the injection mold 120 according to the invention, the base mold 320 of which is designed to produce a bicycle handlebar shaped as a hollow profile from thermoplastic material. The invention will first be explained in relation to the bicycle frame 400, which can be produced with the injection mold 110 shown in Figure 2.
[0073] The partial cavity of the master mold 320 shown in Figure 2 forms a main frame 410 of the bicycle frame 400. A rear triangle 420 of the bicycle frame 400 is molded using a rear triangle forming slide 116.
[0074] The bicycle frame 400 according to one embodiment is shown in perspective in Figure 6. The bicycle frame 400 according to the exemplary embodiment is designed as a mountain bike frame of an electric bicycle. The main frame 410 comprises a seat tube 411, a top tube 412, which extends between the seat tube 411 and a head tube 413, and a down tube 414, which is connected to a motor mounting housing 415. The down tube 414 is designed to receive a battery, which is inserted from below through the motor mounting housing 415 into the frame profile of the down tube 414. The motor mounting housing 415 is integrally connected to a lower part of the head tube 413, the down tube 414, and the chainstays 416 of the rear triangle 420.The rear triangle 420 of the bicycle frame 400 also includes seat stays 417, which are designed as injection-molded solid profiles and which have integrated cable guides 418 in the form of groove channels on their underside facing away from a user of the bicycle frame 400.
[0075] The seat tube 411, the down tube 414, and the head tube 413 are each designed as continuous hollow profiles, with the down tube 414 comprising a fully enclosed profile cross-section with a first profile chamber 419 and a second profile chamber 420 extending parallel to it. The first profile chamber 418 is designed to accommodate the battery.
[0076] As can be readily seen from the perspective view in Figure 6, the down tube 414 has a downwardly open, U-shaped profile cross-section over a portion of its length. The bicycle frame 400 according to the invention is manufactured entirely in one piece from an injection-molded thermoplastic material in a single injection mold 110.
[0077] The seat tube 411 of the bicycle frame 400 and the motor bearing housing 415 are injection molded as internally continuous hollow profiles, the inner cross-section of which is molded via a first pair of slides.
[0078] The first pair of slides comprises a first form slide 111, which defines the inner contour of the engine bearing housing 415 and the lower part of the seat tube 411 adjacent to the engine bearing housing 415.
[0079] Figure 2 shows the first forming slide 111 and the second forming slide 112 in their functional position, in which they collide end-to-end. The first lower forming slide 111 is designed to facilitate demolding with draft angles and is conical in the area of a section leading in the feed direction, whereas the contour of the second upper forming slide 112 is cylindrical and consequently defines a cylindrical inner cross-section of the seat tube 411 in its upper region.
[0080] The head tube 413 and the down tube 414 are formed using a second pair of slides, whose forming slides 113, 114, as can be seen particularly in the enlarged view in Figure 3, interlock positively in their functional position. The second pair of slides comprises a first forming slide 113 and a second forming slide 114, wherein the first forming slide 113 is held in its functional position at its end by the second forming slide 114.
[0081] In order to ensure a compact arrangement of all movable mold parts and an interaction of these mold parts for the purpose of forming the injection-molded article, the first mold slide 111 of the first slide pair and the first mold slide 113 of the second slide pair are designed such that the first mold slide 113 of the second slide pair passes through or penetrates the first mold slide 111 of the first slide pair and can be moved through the first mold slide 111 of the first slide pair into its functional position, in which it interacts with the second mold slide 114 of the second slide pair.
[0082] In the method according to the invention, the second form slide 114 of the second slide pair is first moved into its functional position, i.e. after the closing of the injection mold 110, then the first form slide 113 of the second slide pair is advanced through the first form slide 111 of the first slide pair into its functional position, where it engages positively in a window-like recess 119 of the second form slide 114.
[0083] As can be seen in particular from the enlarged illustration in Figure 3, the first forming slide 113 of the second pair of slides is designed as a double slide with two forming cores extending parallel and at a distance from each other, with which the first and second profile chambers 419, 420 of the lower tube 414 are formed.
[0084] To form a steering bearing seat, a steering bearing slide 115 is further provided, which can be designed in such a way that it centers the second forming slide 114 of the second pair of slides in the functional position.
[0085] Finally, a rear triangle forming slide 116 is provided for the formation of the rear triangle 420 of the bicycle frame 400, which forms a partial contour of the chainstays 418 and the seatstays 417 on each side.
[0086] To ensure the adaptability of the injection mold 110, 120 to different article sizes or designs, for example, to different frame sizes, as superimposed in Figure 7, the injection mold 110, 120 according to the invention comprises several different interchangeable mold inserts 311, 321, which form a partial cavity of the base mold 310, 320. Using the interchangeable mold inserts 311, 321, different articles can be produced with one base mold 310, 320 without the need to provide different base molds for differently designed articles. For example, with the injection mold 110 shown in Figure 2, different sized bicycle frames 400 j can be produced in this way by simply changing the mold inserts 311, 321.As can be seen in particular from the schematic representation in Figure 7, different frame sizes result in different geometries of the bicycle frame 4, for example, different angles between the top tube 412, the head tube 413 and the down tube 414, as well as between the seat tube 411 and the top tube 412. The reach and stack of the different bicycle frames 400 differ from one another. Stack and reach are measured from the center of the bottom bracket. Stack is defined as the vertical distance from the bottom bracket axis to the top of the head tube 413. Reach is the horizontal distance from the center of the bottom bracket to the top of the head tube 413.
[0087] In this case, it is advantageous and appropriate if at least some of the form slides 111, 112, 113, 114, 115, 116 and / or at least some of the form inserts 311, 312 are designed to be adjustable in their position and / or orientation relative to each other.
[0088] In the variant of the injection mold 110 shown in the first embodiment, the mold slides 111, 112, 113, 114, 115, 116 are each adjustable translationally and rotationally, i.e., in two degrees of freedom. To ensure adjustability, some of the mold slides 113, 114, 115 are each attached to the main mold 310 by means of a bracket 312. In the described embodiment, these are the mold slides 113, 114, 115 that are provided for forming the partial cavities with interchangeable mold inserts 311. The respective brackets 312 are adjustably attached to the main mold such that the respective mold slide 113, 114, 115 can be adjusted relative to the main mold 310.The holder 312 is adjustable to the main tool and the mold inserts 311 it accommodates, wherein a first degree of freedom of the holder 312 is achieved by allowing the holder 312 to be divided in or parallel to an adjustment direction of the mold slide 112, 113, 114, and at least a second degree of freedom is achieved by allowing the holder 312 to be adjusted within a division plane of the main mold 310 and at least one angle with respect to the first degree of freedom. The displacement in the adjustment direction of the mold slides is ensured by elongated holes 313 provided in the holder 312, which are penetrated by threaded bolts (not specified in more detail). The holder 312 can be clamped in several positions relative to the displacement axis of the mold slides by means of nuts provided on the threaded bolts.
[0089] To ensure rotational displacement of the brackets 312 at an angle relative to the displacement direction of the form slides 112, 113, 114, for example about a vertical axis, i.e., an axis in the direction of the opening and closing movement of the support plates 210, the threaded bolts of the brackets 312 are positively engaged and guided by means of T-nuts in profile grooves 314 of the main mold 310. The profile grooves 314 extend at an angle to the angle of the elongated holes 313, i.e., perpendicular to them or at an angle other than 0°.
[0090] Since the length of the down tube 414, and thus also the distance from the down tube 414 to the head tube 413, varies due to the geometric differences between different frame sizes of the bicycle frame 400, it is advantageous if the forming slide 113, which forms the down tube 414, has a variable length. As can be seen in particular from Figure 4, the forming slide 113 in question is designed to be adjustable in length.
[0091] A second embodiment of the injection mold 120 according to the invention is shown in Figure 5. The injection mold 120 differs from the one shown in Figure 2 essentially in that the base mold 320 is designed to form a handlebar, which in the described embodiment is designed with a substantially straight handlebar (flat bar or straight bar). With this type of handlebar, it is common to design the handlebar with different widths and with different angles (backsweep).
[0092] The main mold 320 of the injection mold 120 comprises two interchangeable mold inserts 321, each forming one side of the guide to be conveyed. Furthermore, the injection mold 120 comprises two mold slides 120, 121, each of which is adjustably mounted in holders 322 on the main mold 320 in two degrees of freedom. The holders 322 are designed and adjustable in accordance with the holders 312 according to the first embodiment.
[0093] The forming slides 120, 121 are designed to form a steering rod which is formed as a hollow profile made of thermoplastic material, at least over the ends of the handlebars. For this purpose, the forming slides 120, 121 can be axially displaced in the direction of their longitudinal axis into a functional position and into a demolding position.
[0094] The operating principle of the injection mold 120 and its modular design correspond to that of the first embodiment. The description of the second embodiment is therefore limited to highlighting the differences between the embodiments.
[0095] The simpler embodiment shown in Figure 5 differs from the one shown in Figure 2 essentially in that the holders 322 are guided in profile grooves 324, each extending on a partial circular arc in the base form 320 and in the parting plane of the base form 320. Reference numeral list
[0096] Injection mold
[0097] first forming slide of the first pair of slides second forming slide of the first pair of slides first forming slide of the second pair of slides second forming slide of the second pair of slides control bearing forming slide
[0098] Rear triangle form slider
[0099] window-like recess
[0100] Injection mold
[0101] left-hand slider handlebar
[0102] right-hand slider handlebar
[0103] Hot runner system
[0104] Extruder
[0105] carrier plate
[0106] carrier plate
[0107] parent form
[0108] Mold inserts
[0109] Holder for the form slides
[0110] Slotted holes
[0111] Profile grooves
[0112] parent form
[0113] Mold inserts
[0114] Holder for the form slides
[0115] Mold inserts
[0116] Profile grooves
[0117] Bicycle frame 410 main frame
[0118] 411 Seat tube
[0119] 412 top tube
[0120] 413 Head tube
[0121] 414 Down tube
[0122] 415 Engine mount housing 416 Chainstays
[0123] 417 seat stays
[0124] 418 Train guidance
[0125] 419 first profile chamber
[0126] 420 second profile chamber
Claims
Claims 1. Injection mold (110, 120) comprising at least two complementary base molds (310, 320) with interchangeable mold inserts (311, 312) forming an article cavity and defining a negative of an article to be molded, and at least one mold slide (111, 112, 113, 114, 115, 116, 121, 122) which is displaceable at least between a functional position and a demolding position within the injection mold (110, 120) and which, in the functional position within the closed injection mold (110, 120), molds a hollow profile of the article, wherein at least one mold slide (111, 112, 113, 114, 115, 116 , 121 , 122 ) and / or at least one mold insert is designed to be adjustable in its position and / or orientation relative to each other .
2. Injection mold ( 110 , 120 ) according to claim 1 , characterized in that the at least one mold slide ( 111 , 112 , 113 , 114 , 115 , 116 , 121 , 122 ) is designed to be adjustable translationally and / or rotationally .
3. Injection mold according to one of claims 1 or 2, characterized in that the at least one mold slide ( 111 , 112 , 113 , 114 , 115 , 116 , 121 , 122 ) is slidably guided in at least one holder ( 312 , 322 ) of at least one base mold ( 310 , 320 ) and that the at least one holder ( 312 , 322 ) is designed to be adjustable in its position and / or orientation relative to the base mold ( 310 , 320 ) and the mold inserts (311 , 321 ) received by these.
4. Injection mold (110, 120) according to one of claims 1 to 3, with at least one part cavity formed by the mold inserts 311, 321) having a contour corresponding to a negative of at least one main frame (410) of a bicycle, comprising at least one first pair of slides with cooperating first and second form slides (111, 112), wherein the first and second form slides (111, 112) of the first pair of slides are configured to interlock in a functional position within the part cavity of the injection mold (110, 120) at their ends leading into the functional position in the feed direction or to bear against each other with an end face or an end profile.
5. Injection mold ( 110, 120) according to one of claims 1 to 4, characterized by at least a second pair of slides for forming the main frame (410) of the bicycle, comprising at least a first and a second mold slide ( 113, 114 ), which are designed such that the first mold slide ( 113 ) is held in the functional position by the second mold slide ( 114 ) which preferably extends at an angle to the first mold slide ( 113 ), preferably at an end leading in the feed direction into the functional position.
6. Injection mold according to claim 5, characterized in that the first mold slide (111) of the first pair of slides and the first mold slide (113) of the second pair of slides are designed such that the first mold slide (113) of the second pair of slides passes through or penetrates the first mold slide (111) of the first pair of slides and can be moved through the first mold slide (11) of the first pair of slides into its functional position, in which it interacts with the second mold slide (114) of the second pair of slides, preferably in a form-fitting manner.
7. Injection mold ( 110 , 120 ) according to one of claims 1 to 6 , characterized in that means for adjustable alignment of at least one holder of a mold slide are provided, which are designed to ensure the adjustability of the holder ( 312 , 322 ) with at least two different degrees of freedom .
8. Injection mold according to one of claims 1 to 7, characterized in that a first degree of freedom of the at least one holder (312, 322) enables the holder (312, 322) to be divided into sections in or parallel to an adjustment direction of the mold slide (111, 112, 113, 114, 115, 116, 121, 122) and at least a second degree of freedom enables the holder (312, 322) to be adjusted within a division plane of the base mold (310, 320) and at least one angle with respect to the first degree of freedom.
9. Injection mold (110, 120) according to claim 8, characterized in that the second degree of freedom allows the holder (312, 322) to be displaced on a partial circular arc.
10. Injection mold (110, 120) according to any one of claims 1 to 9, characterized in that at least one mold slide (111, 112, 113, 114, 115, 116, 121, 122) is designed to be modular and / or telescopic, in particular such that it has a variable length.
11. Injection mold ( 110 , 120 ) according to one of claims 1 to 10 , characterized in that at least one holder ( 312 , 322 ) is attached to the main mold ( 310 , 320 ) via at least one cam guide .
12. Injection molding tool ( 110 , 120 ) according to claim 11 , characterized in that the cam guide comprises at least one T-nut which is guided in at least one profile groove of a base mold ( 310 , 320 ).
13. Injection mold ( 110 , 120 ) according to one of claims II or 12 , characterized in that at least one profile groove ( 314 , 324 ) extends linearly or arcuately in a parting plane of the base mold ( 310 , 320 ).
14. Injection mold ( 110 , 120 ) according to one of claims 11 to 13 , characterized in that at least one holder ( 312 , 322 ) is attached to a base mold ( 310 , 320 ) by means of fastening means, the elongated holes ( 313 ) of the holders ( 312 , 322 ) passing through them.
15. Injection mold ( 110 , 120 ) according to one of claims 1 to 14 characterized in that the main molds ( 310 , 320 ) comprise at least one hot runner and are clamped on two carrier plates ( 210 , 220 ) which are adjustable relative to each other in the sense of an opening and closing movement .
16. Injection mold (110, 120) according to one of claims 4 to 14, characterized in that it comprises at least four, preferably five, mold slides (111, 112, 113, 114, 115, 116, 121, 122) which partially interact in pairs and which are selected from a group of mold slides (111, 112, 113, 114, 115, 116, 121, 122) comprising at least one head tube slide, at least one seat tube slide, at least one down tube slide and at least one rear triangle slide.
17. A method for manufacturing a structural component for a bicycle, made of a thermoplastic material preferably reinforced with tensile fibers, wherein the method comprises injection molding the structural component as a one-piece molded part into a multi-part injection mold (110, 120) with interchangeable mold inserts (311, 321) forming an article cavity, wherein the method is carried out using at least one mold slide (111, 112, 113, 114, 115, 116, 121, 122) which is displaceable at least between a functional position and a demolding position within the injection mold (110, 120) and which, in the functional position within the closed injection mold (110, 120), forms a hollow profile of the article, and wherein the injection mold ( 110, 120) preferably comprising the features of one of claims 1 to 16. 18.Method according to claim 17 for manufacturing a bicycle frame (400) as a structural component, characterized in that at least some of the frame tubes, preferably at least all frame tubes of at least the main frame (410), are formed as continuous hollow profile sections closed at least over a partial length using a plurality of movable form slides (111, 112, 113, 114, 115, 116, 121, 122) of the injection mold (110, 120), which are movable from a demolding position to a functional position within an article cavity of the injection mold (110, 120) and from the functional position to the demolding position.
19. Method according to claim 18, characterized in that at least one frame tube is formed by means of at least two forming slides (111, 112, 113, 114, 115, 116, 121, 122) which cooperate in a functional position in the article cavity of the injection molding tool (110, 120).
20. Method according to one of claims 18 or 19, characterized in that a seat tube (411 ) of the bicycle frame (400) is molded with a first pair of sliders .
21. A method according to any one of claims 18 to 20, characterized in that a bottom bracket housing or a motor bearing housing (415) of the bicycle frame (400) is molded using the first forming slide (110) of the first pair of slides.
22. A method according to any one of claims 19 to 21, characterized in that at least one frame tube is molded using two first and second forming slides (113, 114) cooperating as a second pair of slides, wherein a first forming slide (133) of the second pair of slides is held in the functional position, preferably at an end leading into the functional position in the feed direction, by a second forming slide (114) of the second pair of slides extending at an angle to the first forming slide (113).
23. Method according to claim 22, characterized in that the second forming slide (114) of the second pair of slides forms a first short tube section of the bicycle frame (400) in the part cavity, preferably as the head tube (413) of the bicycle frame (400), that the second forming slide (114) of the second pair of slides is moved into the functional position first, that the first forming slide (113) of the second pair of slides forms a second long tube section of the bicycle frame (400), preferably as the down tube (414) of the bicycle frame (400), that the first forming slide (113) of the second pair of slides is advanced into the functional position after the second forming slide (114) of the second pair of slides, and that the first forming slide (113) of the second pair of slides is guided at its end leading in the feed direction by the second forming slide (114) ) of the second pair of slides is caught.
24. Method according to one of claims 22 or 23, characterized in that the first forming slide ( 113 ) of the second pair of slides engages in the functional position at an end leading in the feed direction in a form-fitting manner into the second forming slide ( 114 ) of the second pair of slides, preferably immersing itself in a catch opening of the first forming slide of the second pair of slides .
25. Method according to one of claims 17 to 24, characterized in that at least two form slides ( 111, 133) penetrate each other in a functional position within the article cavity.
26. Method according to claim 25, characterized in that the first forming slide ( 113) of the second pair of slides is moved into the functional position through the first forming slide ( 111 ) of the first pair of slides.
27. Method according to one of claims 17 to 26, characterized in that the thermoplastic polymer is filled with tensile-strength short fibers, which are preferably selected from a group of fibers comprising carbon fibers, glass fibers, aramid fibers, Kevlar fibers and basalt fibers.
28. A method according to any one of claims 17 to 27, characterized in that wound, laid and / or woven tensile-strength long fibers are introduced at least in partial areas into the article cavity, which are overmolded with a thermoplastic matrix material, preferably with a polyamide, wherein the tensile-strength long fibers are selected from a group of fibers comprising carbon fibers, glass fibers, aramid fibers, Kevlar fibers and basalt fibers. 29.Bicycle frame made of a thermoplastic material preferably reinforced with tensile fibers as a one-piece injection-molded bicycle frame (400) which is preferably manufactured according to the method with the features of one of claims 17 to 27, comprising several frame tubes which are at least partially designed as continuous hollow profiles, closed at least over a partial length and largely smooth-walled on the inside, with a defined wall thickness and a defined profile cross-section, wherein the frame tubes are connected to each other without fasteners and with a uniform material.
30. Bicycle frame according to claim 29 characterized in that the frame tubes are selected from a group of frame parts comprising a top tube (412), a down tube (414), a seat tube (411), chainstays (416) and seat stays (417), wherein the bicycle frame (400) has at least one main frame (410) comprising at least one seat tube (411) and a down tube (414) and a bottom bracket housing or motor bearing housing (415) connecting these in one piece and a one-piece molded rear triangle (420), the rear triangle (420) of the bicycle frame being designed with seat stays (417) and chainstays (416) which are preferably injection molded substantially as solid profiles.