Patent Application
20240208262
The invention relates to a wheel component for an at least partially muscle-powered vehicle, in particular, a bicycle, comprising a plurality of component parts, which are integrally interconnected and which form a rim with a plurality of integral spokes, wherein the rim and the spokes are manufactured of a fibrous composite material by injection molding. The invention also relates to a method of manufacturing and a tool device for manufacturing a wheel component.
The prior art has disclosed a variety of wheel components manufactured by an injection molding process:
U.S. Pat. No. 5,415,463 has disclosed a rim for a bicycle of fiber glass with fiber reinforcement, comprising a hollow space. The rim is manufactured by an injection molding process, wherein a core of a resin or of a metal having a low melting point is placed in a casting mold. Thereafter, liquefied fiber glass with a fiber reinforcement is injected into the casting mold. As the fiber glass respectively the glass fibers has/have solidified, the core is liquefied by heating, wherein the fiber glass remains solid. The liquid core material can drain off of the finished component through apertures.
A drawback of this manufacturing method is that a suitable core must first be manufactured for each rim. Accurately fitting cores achieve high dimensional consistency. Wheels thus manufactured can be both comparatively lightweight and also sturdy. Reproducible manufacture is basically possible as well. A considerable drawback is, however, that the core is “lost” when manufacturing the rim, and that the core must be precisely positioned. Cores from cost-effective manufacture do not have the required dimensional consistency. By way of compensating for these tolerances, the tools may already be built with higher wall thicknesses. This has negative effects on the weight of the rim. Alternately, the cores must be manufactured to have a very close fit and must be positioned highly accurately, which considerably increases the complexity. Another drawback of the method using a “lost core” is also the high time overhead. This is why this known method is not suitable for series manufacture of wheel components.
US 2007/0 134 455 A1 and JP H08-309 780 A have disclosed methods of manufacturing wheels of fibrous composite materials. These methods involve first, injecting a liquid fibrous composite material into a mold, so that the circumferential rim and the radially aligned spokes are filled with a fibrous composite material. For weight reduction, a fluid is thereafter injected into the fibrous composite material while it is still liquid, to expel that portion of the fibrous composite material which is not yet solidified. This forms hollow spaces both in the rim and in the spokes to thus reduce the weight. The remaining wall thickness can be influenced by selecting the fluid pressure and the time of introducing the fluid. Basically, the system is functional, and operational wheels can be manufactured. It is a drawback, however, that the wall thickness must be consistently dimensioned such that the wheel can reliably withstand the operational loads. Therefore, the wall must be provided with a high thickness so as to result in a high weight. For high quality wheels of fibrous composite materials, the weight is as a rule too high, or the stability under load is too low.
It is therefore the object of the present invention to provide a wheel component, a method of manufacturing, and a tool device for manufacturing a wheel component for an at least partially muscle-powered vehicle, in particular, a bicycle, which has a low weight and which can be produced in series, providing process stability and cost efficiency.
A wheel component according to the invention for an at least partially muscle-powered vehicle, in particular, a bicycle, comprises a plurality of component parts, which are integrally interconnected, forming a rim with a plurality of integral spokes. The rim and the spokes are manufactured of a fibrous composite material by injection molding. The component parts of the rim are at least partially manufactured by an injection molding process involving fluid injection, comprising at least the following process steps:
At least one further component part, forming at least part of a spoke (or the entire spoke), is at least partially formed by the following process steps:
The wheel component according to the invention has many advantages. A considerable advantage of the wheel component according to the invention is that the substantially closed hollow space in the rim is formed by injecting a fluid into the at least partially liquid fibrous composite material. In particular, a “lost core” for forming the hollow space can thus be dispensed with. This allows particularly cost-effective manufacture of the component parts of the rim with a hollow space. Selecting the parameters of material, temperature, pressure, fluid, etc., provides options for specifically controlling the wall thickness of the component parts, which achieve for one, a high stability under load, and for another, a (still) lower weight.
Due to manufacturing the component parts, which form the spokes integrally with the rim, by means of a mold core device (provided for automatic insertion and retraction or extraction), the spokes can be manufactured very precisely and cost-effectively. The straight spokes, in particular, have a constant cross section over at least a major portion of their length. The cross section is constant over preferably at least 50% and, in particular, more than 66% or more than 75% or more than 80% (or 90% or more) of the length of the spoke.
In particular, does the inner diameter and/or the outer diameter and/or the wall thickness of a spoke vary over 50% and, in particular, more than 66% or more than 75% or more than 80% of the length of the spoke, by less than 30% or preferably less than 20% or less than 10%. The deviations may be less than 5%. In particular, does the wall thickness of a spoke vary over 50% and, in particular, more than 66% or more than 75% or more than 80% of the length of the spoke, by less than 1 mm or preferably less than 0.75 mm or less than 0.5 mm or by less than 0.25 mm.
The straight or linear configuration of the spokes allows insertion of retractable and extendable cores in the shape of reusable mold core devices, so as to achieve a particularly accurate fit and reproducibility. The spokes which in normal, regular use are exposed to high and constantly varying loads, can be manufactured cost-effectively, reproducibly, by means of (frequently) re-usable mold core devices, while even the component parts forming the rim can be manufactured cost-effectively, not using any lost cores. Due to retracting and extending the (re-usable) mold core devices, the mold core devices can also be positioned automatically and reproducibly (and highly accurately).
Moreover, using the fluid results in a smooth outline of the wall surface of the hollow space, absent any projections or corners and edges and projections along an outline of the surface, so that any taken-up and operative forces can be evenly received and dissipated. This furthermore provides the component part with an even and particularly thin wall, so as to advantageously enable a (particularly) low weight of the component part.
Preferably, the fluid injected is (at least) one liquid and, in particular, water. Prior to injecting the liquid (in particular, water), a (small) gas volume such as a (small) air volume is injected. Another inert gas is likewise conceivable. One advantage of injecting a gas volume is that it serves as a gas cushion. The gas volume, in particular, serves as an insulating layer between the fluid and the fibrous composite material, which is still liquid, to avoid fast solidification at the flow front. The gas volume is small compared to the entirety of the injected fluid volume (in particular, less than 1/10).
Furthermore, due to the fluid injection in the injection molding process, the wheel component can be produced in series, providing process stability.
A further advantage is that the injection molding process also provides for a very high surface quality of the outer surfaces of the component part, so that after injection molding, the wheel component does not require much post-processing or nearly none at all. As a rule, however, sprues, spills, and mold separation points and the like, will be after-treated respectively finished.
Moreover, component parts can be manufactured with hollow spaces with complex geometries, such as branching or cross sections curving along an outline, and with cross sections varying along an outline. There is no need for manufacturing specific cores.
Preferably, the fibrous composite material comprises at least carbon fibers and/or glass fibers and at least one substrate material.
Advantageously, (relatively) short-fiber fibrous composite materials or fibrous composite materials including medium length fibers are used, which can be processed in an injection molding process, and can particularly well accommodate and transmit dynamic loads, and have a homogeneous material quality. The fibrous composite material, in particular, comprises at least one fibrous composite material comprising at least one polyamide, such as PA66, PA6.6 or PEEK. These fibrous composite materials are preferably completely recyclable. This is particularly advantageous and enables a sustained product circle.
Preferably, fibrous composite materials with fibers of a length between 0.05 mm and 40 mm are used. If short fiber-reinforced materials are used, the average fiber length is preferably about 0.2-0.4 mm.
Particularly preferably, fibrous composite materials with fibers of an (average) length between 0.2 mm and 15 mm are used. In specific configurations, fibrous composite materials with fiber proportions of more than 25% or more than 50% having a length of more than 2 mm or more than 5 mm and less than 20 mm, have been used. Preferably, (long fiber-reinforced) fibrous composite materials with fibers in a length of (average) ca. 12 mm are used. There are indications that this improves the mechanical properties.
Another considerable advantage is a homogeneous, or more homogeneous, material quality. Another advantage is that a (locally) specific orientation of the fibers (or short fibers) is possible in the process.
The hollow space comprises, in particular, (in the component parts of the rim) at least one opening reaching through the wall of the component part, and preferably at least two openings, which may be generated by injecting the fluid for forming the hollow space and by the fluid exiting from the hollow space. The hollow space may comprise more than two openings.
Preferably, at least two component parts are comprised. The component parts are, in particular, integrally interconnected. The component parts may advantageously be interconnected immediately during manufacture, by injecting the fibrous composite material into all the cavities (simultaneously or nearly simultaneously), at least before the fibrous composite material in a cavity is solidified. Particularly advantageously, this achieves homogeneous material properties, and, in particular, a homogeneous material structure, of all the component parts of the wheel component, wherein no joints or parting lines are formed between the component parts, which might adversely affect the stability of the wheel component.
Particularly preferably, the hollow spaces of the (at least two) component parts are (at least partially) separate from one another. The separate hollow spaces, in particular, do not have any connection. Preferably, a wall is configured between the hollow spaces (at least in sections). Advantageously, the component parts and, in particular, the hollow spaces can thus be manufactured and, in particular, formed separately and independently from one another, in particular, by different methods. Alternately, two or more hollow spaces may be interconnected, forming a continuous hollow space which extends through a number of component parts.
At least one component part (of the at least two component parts) is manufactured by an injection molding process with fluid injection, and at least one other, in particular, a further, component part is manufactured according to another, in particular, further, method, likewise an injection molding process, and differing in at least one process step from the injection molding process involving fluid injection. Preferably, with the other method, no fluid is injected for forming a hollow space. Advantageously, the advantages of different injection molding processes are utilized for manufacturing the wheel components. Advantageously, these at least two component parts are likewise integrally interconnected.
Preferably, a mold core device with at least one permanent, in particular, metallic, mold core is used. The mold core device, in particular, comprises at least one rod-like mold core, which can be retracted from the solidified component part. Advantageously, forming a hollow space by means of a permanent mold core device can be advantageously used for hollow spaces with a straight shape and, in particular, a constant cross section. These process steps can advantageously be connected with the injection molding process involving fluid injection. Preferably, the hollow spaces formed by the mold core device are delimited and, in particular, separated from the hollow spaces, which are formed by fluid injection. Advantageously, at least one spoke of a wheel component can be manufactured by the method.
Preferably, at least one other, and, in particular, a further, component part is manufactured from a fibrous composite material, which is at least partially manufactured by an injection molding process, which comprises at least the following steps:
Advantageously, at least the hub body (or other inserts as well) may be incorporated in the component part. Advantageously, already prior to manufacturing the component part, the hub body may be machined completely by an injection molding process. This incorporates into the wheel component e.g. functional surfaces having narrow tolerances, such as fits or alignments, immediately during manufacturing, requiring no further subsequent machining. In this way, the takeup device thus, in particular, aligns and, in particular, centers the hub body in the cavity. Advantageously, at least one component part configured as a hub of the wheel component can be manufactured by the other method.
It is also possible to cast two (or more) hub body components as inserts. For example, two or more separate hub body components can be inserted in a defined position.
Preferably, the hub body has at least one mold element, which is at least partially enclosed in the fibrous composite material. Advantageously, the mold part forms at least one form closure between the hub body and the solidified fibrous composite material. Advantageously, the mold element ensures a form-closed force transmission. Preferably, the mold element is configured as a notch, groove, lug, or wing, on the hub body. The mold element, in particular, extends at least partially transverse to the direction of load application of the hub body (this means, in particular, that the mold element forms the hub body locally non-round). Preferably, the mold element enables a safe force transmission between the hub body and the fibrous composite material, even in the case of high loads and, in particular, in the case of thermal expansions.
The hub body is, in particular, manufactured of a metal, such as aluminum, or at least comprises aluminum. Bearing seats, preferably for ball bearings or for sliding half bearings, are expediently configured on the hub body. Preferably, the hub body may also comprise further functional components, such as a freewheel device or the like. The listing is exemplary only, and not final.
Preferably, at least one component part is configured as a component part selected from a group comprising at least one spoke, at least one rim segment of a rim, a rim and at least one hub of a wheel. Advantageously, such a wheel component may be configured as a substantially closed and (locally) tube-like hollow body structure, which can be produced to be particularly stable and lightweight and in series, providing process stability.
Preferably, a rim segment comprises two opposed rim flanks with a rim well and a rim base, and preferably rim flanges, on the two rim flanks.
In a suitable configuration, the wheel component is configured as a wheel, e.g. a front wheel or a rear wheel. The wheel has a plurality of component parts. The component parts comprise (at least) one circumferentially closed rim with a plurality of rim segments, and a plurality of spokes, and, in particular, a hub. At least one rim segment is, in particular, manufactured by an injection molding process with fluid injection. The other, and, in particular, further, component parts, i.e. the component parts configured as spokes, are manufactured by a different (injection molding) process. Preferably, the wheel comprises between three and ten spokes. Particularly advantageously, the hollow spaces of the individual component parts are separate from one another, so as to provide a particularly stable hollow space structure with a large number of bracings. Particularly advantageously, the wheel therefore has high stability under load and a low weight. The wheel can be manufactured in series manufacture, showing process stability.
The component parts are, in particular, shaped and integrally interconnected in the manufacturing process, so that no subsequent assembly of multiple different component parts is required. At the same time, a hub body may be received or provided in the hub, with machined, functional surfaces such as bearing seats. The pertaining surfaces of the hub body are first machined with precision. For example, a bearing seat is machined first.
The method according to the invention serves to manufacture a wheel component for at least partially muscle-powered vehicles and, in particular, bicycles with a plurality of component parts which are integrally interconnected and form a rim with a plurality of integrally configured spokes, wherein the rim and the spokes are manufactured of at least one fibrous composite material by injection molding. The method comprises at least the following process steps:
At least one further component part, which forms at least part of a spoke, is manufactured by the following process steps:
The wheel component with the rim and the integrally interconnected spokes is removed from the tool device.
The method according to the invention has many advantages. It is a considerable advantage of the method according to the invention that no lost mold core is required for forming the hollow space, so that the method can be carried out cost-effectively in series manufacture. Advantageous specific embodiments of the method can be taken from the entire application.
Preferably, the fluid (in particular, water and first some gas) is injected when the fibrous composite material is at least partially solidified (directly) on a wall of the cavity and forms a wall of the component part. Preferably, the fibrous composite material is solidified along a substantial portion of the wall prior to injecting the fluid. Advantageously, a time offset between injecting the fibrous composite material and injecting the fluid presets a wall thickness of the component part, so as to allow manufacturing a wall with a defined wall thickness.
Suitably, the wall of the cavity is at least partially cooled, preferably by means of at least one cooling device. This allows, in particular, to preset a particularly precise wall thickness of the wall. Furthermore, the speed of the solidification process can be influenced, and preferably accelerated, by cooling by means of at least one cooling device.
Particularly preferably, the cavity is (quasi or nearly) completely filled with the fibrous composite material prior to injecting the fluid, so that the liquid fibrous composite material is at least displaced (at least) partially from the cavity by the injection of the fluid. In particular, is the displaced fibrous composite material displaced into (at least) one overflow volume, such as an overflow cavity. In particular, is the cavity filled at least 90%, 95%, 99% or even more, with fibrous composite material. Advantageously, at least the wall of the cavity substantially completely wetted before the fluid is injected. Advantageously, this ensures at least that any place in the cavity is provided with sufficient fibrous composite material for forming a continuous wall of a component part. Furthermore, the volume compensation can minimize, and, in particular, prevent, component stresses, in particular, due to shrinkage during the solidification process. Advantageously, the fibrous composite material displaced from the cavity can be re-used.
In particular, can the exit of displaced fibrous composite material be limited by a valve device having at least one movable control element, such as a mechanical slidegate, to optimize the manufacturing process. Preferably, the valve device at least partially prevents the fibrous composite material from draining into the overflow volume, at least while the fibrous composite material is injected.
Advantageously, the cavity is at least partially evacuated prior to, or at least during, the fluid injection. Advantageously, this enables to prevent any (gas) inclusions and defects in the component parts. Preferably, the cavity can be evacuated by at least one pump or the like.
Suitably, the tool device comprises at least two cavities for manufacturing two component parts. Preferably, the cavities are at least partially interconnected. Suitably, each cavity receives (separate) injections of fibrous composite material, so that the fibrous composite material bonds and an integral wheel component is formed from the two or more component parts.
In particular, is the fibrous composite material (nearly) simultaneously injected into each of the cavities, wherein the fibrous composite material in each of the cavities is at least partially liquid, so that it can combine with the other fibrous composite material (resulting in one single material). Particularly advantageously, a wheel component having multiple component parts can thus be formed, and showing no transition lines, seams or parting lines. In particular, do the component parts make seamless transitions, so that force flow between the component parts is not (adversely) affected.
Preferably, the fluid comprises at least one gas or a gas mixture, such as, in particular, air or an inert gas or a noble gas. Advantageously, a gas or a gas mixture can be compressed and can compensate for material shrinkage when the fibrous composite material solidifies. Suitably, the fluid comprises at least one liquid, in particular, water. Advantageously, liquids have a high heat capacity, so that the liquid fibrous composite material cools off faster. Advantageously, the fluid may be a mixture of at least one gas and a liquid, so that the advantages of gases and liquids can at least partially be combined.
In a further configuration of the invention, at least one projectile element may be provided in addition to the injected fluid, which projectile is at least partially urged by the fluid through the cavity with the liquid fibrous composite material, thus clearing the hollow space. Advantageously, this allows very precise presetting of the wall thickness, in particular, with large diameters of the hollow space.
The apparatus according to the invention with a tool device serves for manufacturing at least one wheel component for at least partially muscle-powered vehicles and, in particular, bicycles. The tool device serves to manufacture wheel components, each comprising a plurality of component parts, which component parts are integrally interconnected. The component parts form a rim and a plurality of integrally configured spokes, wherein the rim and the spokes are manufactured of a fibrous composite material by injection molding in the tool device. The tool device comprises, for configuring the component parts of the rim and the spokes, at least two molding devices, which form at least one (open or closed) cavity for forming a plurality of integrally interconnected component parts of the wheel component. For forming at least one component part of the rim, at least one injection port for injecting an at least partially liquid fibrous composite material and at least one injection nozzle for injecting at least one fluid is comprised within the (one) cavity for forming at least one hollow space within the component part of the rim. The tool device comprises at least one further cavity, which is connected with the cavity with the injection port. The tool device comprises a plurality of mold core devices, which, for forming hollow spaces in the spokes as component parts, are each retractable into, and extendable out of, the further cavities.
The apparatus according to the invention and the tool device also have many advantages. It is a considerable advantage of the tool device to enable the forming of a component part with at least one substantially closed hollow space, cost-effectively, and with process stability, in series manufacture. Advantageous specific embodiments of the tool device can be taken from the entire application.
Suitably, the molding devices comprise corresponding alignment units, by means of which the molding devices can be aligned to one another, to enable a defined geometry, and, in particular, outer contour, of the component parts.
Advantageously, at least one injection molding device is used with at least one heating device, at least for heating and liquefying the, in particular, granular fibrous composite material, and at least one conveyor device for injecting the at least partially liquid fibrous composite material into the cavity of the tool device. In particular, at least one plasticizing unit is comprised.
Preferably, the fibrous composite material is at least partially injected through a conveyor device, such as an auger device, a (hydraulic) pump, and/or by gravity.
Advantageously, the tool device comprises at least one cooling device, such as a water jacket, for cooling the molding devices and controlling the solidification process of the fibrous composite material.
The tool device, in particular, comprises at least one outlet nozzle disposed on the cavity and through which the injected fluid can exit back out of the hollow space.
Preferably, the tool device comprises at least one further cavity, which is connected with the cavity with the injection port. In particular, at least one mold core device is comprised, which can (at least partially) be disposed within the further cavity for forming a hollow space. Suitably, the mold core device can at least partially be inserted into the second cavity for forming a second hollow space, which is, in particular, separate from the first hollow space. Alternately or additionally, at least one takeup device for disposing, and, in particular, centering, at least one (separate) hub body or other insert is at least partially comprised within the further cavity. Advantageously, the hub body can be accommodated for casting in the third cavity. Advantageously, this carries out different injection molding processes with one tool device, in particular, simultaneously with manufacturing an integral wheel component.
The tool device, in particular, comprises at least two and preferably at least four and particularly preferably at least five, in particular, (nearly) identical, tool segments. Each tool segment comprises at least one cavity with at least one injection molding device with at least one injection nozzle. “Nearly identical” means, in particular, that the tool segments are the same or partially identical, other than e.g. a configuration of a valve gate or a takeup for a rim magnet (or similar small deviations). As a rule, e.g. exactly one segment is provided for the valve gate.
Preferably, the tool device comprises at least one overflow volume, such as an overflow cavity. Suitably, displaced fibrous composite material can be drained off through the cavity into the overflow volume, in particular, when forming a hollow space by fluid injection. Suitably, each tool segment comprises a separate overflow volume. Advantageously, the overflow volume enables in each tool segment, a short travel for compensating the fibrous composite material, so as to reduce, and, in particular, minimize, the probability of material defects due to shrinkage of the fibrous composite material during solidification of the fibrous composite material.
Alternately, the takeup volume may be formed by the injection molding device itself, so that the displaced liquid fibrous composite material is urged back into the injection molding device.
In a preferred specific embodiment, each tool segment of the tool device comprises at least one injection port for injecting an at least partially liquid fibrous composite material and at least one assigned injection nozzle for injecting at least one fluid for forming hollow spaces in the rim segments, and a mold core device provided for controlled traversing for forming the pertaining hollow space in a spoke.
Further advantages and features of the present invention can be taken from the exemplary embodiment which will be described below with reference to the enclosed figures.
The figures show in:
The
The wheel components 1 comprise component parts 2, 2a and 2b. The component parts 2 are rim segments 111 of the rim 111a, and the component parts 2a form the spokes 109, which connect the central component parts 2c (central component) integrally with the rim 111a.
A bicycle 100 comprises a frame 103, a handlebar 106, a saddle 107, a fork or suspension fork 104 and in the case of the mountain bike, a rear wheel damper 105 may be provided. A pedal crank 112 with pedals serves for driving. Optionally, an electric auxiliary drive may be provided on the pedal crank 112 and/or the wheels 101, 102. The hubs 110 of the wheels may be attached to the frame 103 by means of a clamping system 113 (for example a through axle or a quick release).
In all the configurations, the wheel component 1, and, in particular, the component parts 2 (rim segments 111), the component parts 2a (spokes 109), and the central component part 2c, are manufactured quasi concurrently with the cast-in hub body 10. “Quasi concurrently” means that these component parts are preferably all manufactured (in one process step), while and as long as all the component parts are located in one (shared) tool device. This means that the component parts are integrally configured within the tool device. The parts are not produced separately, taken out of the production, and then interconnected.
The component part 2 configured as a rim segment 111 is manufactured by an injection molding process with fluid injection, and therefore has a hollow space 5 formed by injection of a fluid 4, which extends along the peripheral direction of the rim 111a. The rim segment 111 or the component part 2 may be referred to as a peripheral component. Due to the manufacturing process, the hollow space 5 has two openings 5a reaching through the wall 7, for inlet and outlet of the injected fluid 4. The openings 5a can be closed airtight by plugs or end covers, not shown, so that tubeless tires can also be used in combination with the wheel component 1 according to the invention.
The spokes 109 as the component parts 2a, also comprise hollow spaces 5, each of which is shaped by means of a mold core device 52. The hollow spaces 5 of the component parts 2a are separated from one another by walls 7 and not connected, i.e., there is no continuous connection between the hollow spaces 5. Each mold core device 52 (
The rim segment 111 comprises two rim flanges 12, 13, a rim well 17, a rim base 14, and two rim flanks 15, 16. Between the rim base 14, the rim well 17 and the rim flanks 15, 16, the cavity 5 is configured, which is manufactured by an injection molding process with fluid injection, and which curves along the rim segment 111, in the plane of the drawing.
The component parts 2, 2a, 2b are all manufactured by an injection molding process. The component parts 2, 2a are integrally interconnected, showing a homogeneous material structure, and not showing any seams or transition lines.
In all the configurations and embodiments, examinations by section determines that the cavities 109b in the spokes 109 have been formed or shaped by (smooth) mold core devices 52, inserted prior to injection molding and retracted or removed thereafter. The inner surface is configured (nearly perfectly or perfectly) symmetrical and remains unchanged over substantial portions of the length. The inside surfaces of the component parts 2 (rim segments 111) show considerably more surface variations, since as a rule the injected fluid causes less than perfectly smooth and symmetric surfaces in manufacturing, even though the surface quality on the inside is good and the wall thickness constancy meets requirements. In this respect there are measurable differences in different component parts 2, 2a, which determines the type of the (local) manufacturing method.
The tool device 50 is subdivided in five equal tool segments 51. Each of the tool segments 51 comprises an injection molding device 56, through which the at least partially liquid fibrous composite material 20 can be injected, at least into the cavities 3 of the tool device 50 assigned to the tool segment 51. The quantity of the tool segments 51 corresponds to the quantity of the spokes 109 of the wheel component 1 configured as a wheel 101, 102. Furthermore, the injection molding device 56 comprises further elements such as a takeup volume 8, not shown in detail.
The wheel component 1 configured as a wheel 101, 102 comprises component parts 2 manufactured by an injection molding process with fluid injection, and further component parts 2a manufactured by an injection molding process where no fluid 4 is injected, thus differing from the injection molding process with fluid injection in at least one process step.
The rim segments 111 are formed by component parts 2 manufactured by an injection molding process with fluid injection. The spokes 109 shown are formed by other component parts 2a, manufactured by an injection molding process, wherein a mold core device 52 is inserted into the cavity 3 for forming a hollow space 5. The component part 2a configured as a hub 110 comprises the insert configured as a hub body 10, which is cast in.
For manufacturing the wheel component 1 configured as a wheel 101, 102, the cavities 3 are configured such that the walls 3a of all the cavities 3 correspond to an outer surface of the wheel component 1. The cavities 3 are interconnected, so that the component parts 2, 2a, and also the resulting wheel component 1, are integrally configured.
For manufacturing the wheel component 1, a mold core device 52 is first inserted into the cavity 3, forming a component part 2a configured as a spoke 109. The geometry of the mold core device 52 determines the shape of the hollow space 5 within the component part 2a configured as a spoke 109. The mold core device 52 shown is configured as a slidegate, which is retracted into the cavity 3. The slidegate shows a cross section (e.g. round) so that the slidegate can be extended again (without any problems).
This slidegate preferably shows an oval or round cross section. Or, the cross section may be configured non-round or star-shaped. As a rule, the slidegate travels (only) linearly. Other than linear movement, however, a rotary motion is likewise conceivable, so that e.g. a helical cavity forms.
The hub body 10 is received centered by a takeup device 55 and oriented within one of the cavities 3.
The cavities 3 are evacuated through the outlet nozzle 54b by means of a pump, not shown. During evacuation, the at least partially liquefied fibrous composite material 20 is injected through the altogether five injection ports 53 of the tool device 5. The fibrous composite material 20 fills the cavities 3. All the cavities 3 are completely filled with fibrous composite material 20. When the fibrous composite material 20 is at least partially solidified on the wall 3a of the cavity 3, a fluid 4 for forming the hollow space 5 is injected into the rim segments 111 through the injection nozzles 54.
Due to the high heat capacity, water is used as the fluid 4. The fluid 4 displaces the fibrous composite material 20 into the overflow volumes 8, which are configured as overflow cavities 8a. The overflow cavities 8a can be adaptively selected by means of a valve device 8b configured as a control element 8b, comprising a mechanical slidegate. Alternately, the displaced fibrous composite material 20 may be displaced, and, in particular, urged back, into the injection port 53. Additionally, the walls 3a of the cavities 3 may be cooled by cooling devices 57 in the shape (e.g.) of a water jacket with water pipes, to control and accelerate the solidification process. By way of example, a water jacket of a cooling device 57 is configured, comprising a number of cooling pipes disposed within the mold core device 52.
The hub body 10 is enclosed by the fibrous composite material 20, the mold elements 10a establish a form closure between the hub body 10 and the fibrous composite material 20.
After solidification, all the component parts 2, 2a are integrally interconnected. The hollow spaces 5 manufactured by fluid injection and the mold core device 52 are separated from one another. The finished wheel component 1 can be removed and can, without any further post-processing or further manufacturing steps, be prepared for mounting, for example by inserting the bearings into the bearing seats 11.
When the fibrous composite material 20 is at least partially solidified on the wall 3a of the cavity 3, the fluid 4 is injected so as to form the hollow space 5. The solidification process is assisted by a cooling device 57 configured as a water jacket. Injecting the fluid 4 displaces a part of the still liquid fibrous composite material 20 into the overflow volume 8. The fluid 4 forms the hollow space 5 provided in the solidified component part 2.
The wall 7 shows an even, thin wall thickness 7a, which can be preset by controlled use of the cooling device 57. While the hollow space 5 forms, the injected fluid 4 is at least partially urged back out through the opening 5a in the hollow space 5. The injection nozzle 54 and the outlet nozzle 54b are represented in this Figure by the same opening.
While a particular embodiment of the present wheel component, method of manufacturing, and tool device have been described herein, it will be appreciated by those skilled in the art that changes and modifications may be made thereto without departing from the invention in its broader aspects and as set forth in the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2022 134 718.4 | Dec 2022 | DE | national |
