TW515762B - Method for fabricating a bicycle wheel hub, apparatus for implementing the method and hub thus obtained - Google Patents

Abstract

The wheel hub of a bicycle is made of a single part of structural fibre based material, typically carbon fibre material, after reticulation in a mould which exploits the thermal dilation of a core made of high thermal dilation synthetic material, preferably PTFE, to obtain the application of a radial pressure to the tubular body consisting of layer of structural fibre based fabric.

Description

515762 V. Description of the invention (1) The present invention relates to a method for manufacturing a hub of a pedal wheel, a device for performing this method, and a hub thus completed. In recent years, the applicant has carried out various investigations and tests to manufacture bicycle parts, especially bicycle wheel hubs, especially for spokes of racing bicycles, which use structural fiber based materials. material), typically a carbon fiber based material. This type of material offers the advantage that it is lighter in weight than metal materials. Because of the typical construction of such a pedal wheel hub described above, it is difficult to manufacture a hub from a single part of a carbon fiber-based material, at least at the time. To ensure that the hubs used in today's pedal wheel hubs exhibit a composite cylindrical shape with a centrally fixed diameter portion and a wider bell-shaped end section. In addition, it has been desired to continuously increase the thickness of the hub from the central portion toward the end of the hub, and the required resistance characteristics in all regions of the hub, especially on such ends, where When the spokes are fixed, they also maintain a minimum weight. The need to manufacture a tubular body with a composite profile as described above makes it possible to manufacture the hub from a single part of a structural fiber material, such as a carbon fiber material. The object of the present invention is to overcome such technical problems. -A substantially cylindrical core is provided, which is made of a synthetic material having a thermal expansion coefficient exceeding 5x10-5 mm / ° C and a maximum continuous heat resistance at least equal to 80 ° C.

515762 V. Description of the invention (2)-Use many layers of structural fibre fabric, which are incorporated into a matrix of plastic material surrounding the core to form a laminated tubular body (which Having a predetermined shape and thickness),-setting the core with the laminated tubular body formed thereon in a mold,

-Increasing the temperature of the mold to a number sufficient to cause expansion of the material forming the core, which exerts a radial pressure on the tubular body in the mold and also causes a matrix of the plastic material matrix Reticulation, and-removing the tubular body from the mold and from the core to complete a single wheel hub of a single part formed of a structural fiber material. Preferably, the material forming the core has a thermal expansion coefficient exceeding 9x10-5 mm / t and a maximum continuous heat resistance exceeding 100 ° C.

Again, preferably, the material forming the core may be polytetrafluoroethylene (PTFE), or fluorinated ethylene propylene (FEP), or polyvinyl chloride trifluoride (PCTFE) or polyvinylidene fluoride (PVDF) or High density polyethylene (PE-HD). Because of the anti-adhesive properties of PTFE materials [which makes it easier to separate the core from the structral fibre moulded body], and because of the high continuous heat resistance of PTFE materials such as 260 ° C [ Due to the good thermal conductivity of this material (0.25 W / m ° C) and also due to the good thermal capacity (especially heat) of this material equal to 1.045U / kg ° C, so roughly speaking The use of PTFE is preferred. The method with the above-mentioned substantial stages is generally used to manufacture a wheel hub having all shapes, but it can also be different from the above-mentioned shape. This method -4- 515762 5. An essential feature of the invention description (3) is that the aforementioned core made of a high thermal expansion synthetic material (preferably PTFE) is provided. This material will exhibit high thermal expansion characteristics at relatively low temperatures. In the order of temperature, the plastic material (containing the structured fiber fabric) will produce a network structure.

Structural fiber fabrics that have been incorporated into a matrix of plastic material have been known and used for some time. They are made from yarns made of structural fibers, such as carbon fibers. These fabrics are then subjected to a calendering process to combine them with a matrix of plastic material, typically a thermoset plastic material.

According to other features of the present invention, many fabric layers of this type will wrap around the core, and its shape corresponds to the shape of the core (to be completed). Such a wheel will exhibit a high thermal expansion coefficient synthetic material The aforementioned features made. In this way, when the mold is heated to produce a reticulated structure of the thermoset precursor of the laminated tubular body (which is wrapped around the core), the layer of material forming the core expands, whereby the A radial pressure is applied to the body to complete a product with the necessary structural characteristics. The basic advantage of the thermal expansion core is that the pressure can be applied evenly despite the pre-formed tubular body's possible composite profile (with two enlarged bell-shaped end portions and a continuously increasing thickness) as described at the beginning of this specification. As described above, in a preferred form of the embodiment of the present invention, the structural fiber is a carbon fiber, and the plastic material precursor is a thermosetting plastic material precursor. The temperature at which the mold must be heated to complete the process is in the range of 80 ° C to 200 ° (:. The mold is preferably maintained at a temperature in this range and lasts from 30 minutes to 3 hours. Scope of time. 515762 V. Description of the invention (4)

In the case where the method according to the present invention is performed to produce a hub having the above-mentioned composite shape, the method is characterized in that the core will present a cylindrical central portion and two preferred diameter end portions and be Consists of two separate, axially continuous elements that have a contact plane perpendicular to the axis of the core to enable the core to be separated from the tubular body after being taken out of the mold. As mentioned above, the tubular body is preferably formed in advance so as to appear. A cylindrical central section and two enlarged end sections, which are continuously increasing in thickness toward these ends. According to other preferred features, as described in other common patent applications by the applicant, the fabric layers on the core include one or more ends and central portions of each larger diameter surrounding the core Fabric wraps of wrappings and many plies (which extend the entire length of the core), each of which will partially cover the core in a peripheral direction The folds are applied to several faces on the core to provide resistance to the structure in the axial direction.

As mentioned above, the special layering described above is protected by the present invention as the focus of the above features and also protected by the applicant's specific common patent application. In a preferred form of the example of the invention, the two elements forming the core are combined with two end ring flanges which are used to limit and contain the ends of the tubular body formed in advance on the core. The invention also relates to a device for performing the above method. According to the invention, the device is characterized by:-a mold having a cylindrical recess, -6-515762 V. description of the invention (5)-a substantially cylindrical core, which will present a more than 5x1 (Γ 15 mm / ° C thermal expansion coefficient and a maximum continuous heat-resistant synthetic material (preferably PTFE) exceeding 80 ° C) with structural fibers incorporated in a plastic material matrix Many layers of fabric are applied to form a laminated tubular body (which has a predetermined shape and thickness) around the core.-Device for bringing the temperature of the laminated body to a temperature sufficient to cause the plastic material matrix to cause The mesh structure and the number of swellings that cause the material (which forms the core) to exert a radial pressure on the tubular body in the mold, where the core presents a cylindrical central portion and The two wider diameter end portions are composed of two separate, axially continuous elements that have a contact plane perpendicular to the axis of the core to allow the core to be removed from the mold after removal from the mold. The tubular body Leaving out: and • elastic device, which is used to elastically suppress the elements forming the core (which are close to each other), and these elements combined with two end ring flanges are used to axially restrict the tube The end of the body (9). In a preferred form of the example, the mold includes a cylindrical recess (the end of which is closed by two covers), both of which include a spiral for individually moving the spiral The outer shell of the spring is inserted axially between the cover and the individual elements of the core. Finally, according to another idea, the invention also relates to a bicycle wheel hub completed by the method according to the invention. The hub according to the present invention is characterized in that it is made of a structural fiber-based material (which is incorporated into a plastic material matrix) 515762 V. Description of the invention (6) A single tubular body, the single tubular body has a A cylindrical central portion and two enlarged end portions. Preferably, the hub according to the present invention will exhibit a continuously increasing thickness from the central portion toward the ends. (Non-limiting example) to illustrate the present invention in detail: wherein FIG. 1 shows a perspective view of the core, which belongs to the device used in the method according to the present invention, and FIG. 2 shows the formation of the core in FIG. 1 The three-dimensional views of the two elements of the core are in a state separated from each other, and FIGS. 3 to 15 are perspective views illustrating examples of the method of laminating the carbon fiber fabric on the core shown in FIG. 1. At various stages, FIG. 16 is a perspective view, which exemplifies the core in FIG. 1. The core is a layer covered with a carbon fiber fabric. FIG. 17 is an example illustrated in FIG. 16 Partial cross-sectional view of the assembly with two elements forming the core and a pre-formed tubular laminate on the two elements; and-Figure 18 is a cross-sectional view of a mold used in the method according to the invention . Referring to Fig. 1, the numeral 1 indicates a generally cylindrical core, which is composed of two separating elements 3,4. In this example, each of these two elements 3, 4 is made of a single piece (with PTFE). In the closed condition exemplified in Figure 1, the two elements 3, 4 will form a cylindrical core with a substantially central portion 2, which presents a fixed diameter and two bell-shaped end portions 5 , 6 (which has an enlarged diameter and ends in two ring flanges 7, 8). 515762 V. Description of the invention (7) With reference to Figures 3 to 16, the core 1 is externally covered with layers of a structural fiber-based fabric (typically a carbon-based fabric), which is incorporated into the structure. A thermosetting plastic material matrix. The various stages of this lamination method are exemplified in Figures 3 to 15.

Referring to FIG. 3, in a first stage, a belt 50 of carbon fiber fabric is wound around the bell-shaped end 5 of the core 1 (for example, as many as 5 turns around the core). After that, on the end 6 of the core 1, the same operation is performed using a fabric tape 51. Figure 4 illustrates the core with two windings 50, 5 1 completed by the tail of the previous stage.

A first pleated layer 52, a second pleated layer 53 (Figure 5), a fourth pleated layer 54, a fifth pleated layer 55 (Figure 6) and then applied to subsequent stages The body is completed in. Each of these folds 52,53,54,55 will extend over the entire axial length of the core, and each of these folds will only partially cover the core in the direction of the circle. As can be seen in Figures 5 and 6, they are applied to four different faces, which correspond to each other at an angle of 9 (Γ. First, the two pleats 52, 53 (which are oppositely opposed) are After being applied, the other two pleated layers 54, 55 (also oppositely opposite and corresponding to the pleated layers 52, 53 at an angle of 90 ° C) are also applied. The seventh example is given in the fifth, The structure completed at the end of the example stage shown in Figure 6. Since the pleats are connected to the layers at the end of the core, and thus provide axial resistance to the laminate, the functions of the pleats described above It is very important. At the end of the above stage, the two straps 56, 57 (picture 8) are wound-9-515762 5. Description of the invention (8)

The structure shown in Figure 9 is completed on the layers in subsequent stages with respect to the ends of the core. At this point, two additional straps 58, 59 are additionally wound around the end of the core (Figure 10), after which the two additional pleats 60 0, 6 1 (which are oppositely opposed and whose shape is (Shown in Figure 11) is applied. Obviously, the pleats are applied in subsequent stages to complete the structure shown in Figure 12, where the pleats will connect the end layers to additionally increase the axis of the laminate To resist.

The method ends with the use of two additional straps 62, 63, the shape of which is shown in Figure 13 and it is wound on the ends of the core to complete the visible in Figure 14 The structure, after that, a final strap 64 (the outer shape of which is shown in Fig. 15) is applied and wound around the central portion of the core in order to finally complete the shown in Fig. 16 The structure. Once this method is completed, a tubular body 9 is formed on the core (Fig. 16), a central fixed portion 10, and two bell-shaped ends 11, 12 (the diameter of which is larger). Further, as seen in Fig. 17, the thickness of the pre-formed tubular body 9 is continuously increased in the direction from the central portion 10 to the ends. Finally, the two ring-end flanges 7, 8 of the core 1 axially contain the ends of the pre-formed tubular body 9. The assembly consisting of the core 1 (which contains two elements 3, 4 and a pre-formed tubular body 9 wound thereon) is positioned in a recess 13 of a molding device 14 (refer to FIG. 18) ). The cylindrical recess 13 is formed by an upper mold half 15 and a lower mold half 16 which present an outer shape corresponding to the shape of the outer surface of the hub to be completed, that is, substantially corresponding to- 10-515762 V. Description of the invention (9) The outer surface of the preformed tubular body 9 as exemplified in FIG. 16. The ends of the recess 13 are closed by covers 17, 18 (which are fastened to the two end flanges of the two mold halves 45, 46 by screws 19). Each of these two lids 17 and 18 is combined with a central cylindrical case 20 in which an individual coil spring 21 is provided. Each of the two springs 21 is inserted axially between the bottom end 20a of the individual tubular housing 20 and the individual end surface of the core 1. The two springs 21 elastically press the two elements 3, 4 of the core 1 with the two elements 3, 4 abutting each other so that the elements can maintain contact with respect to their contact plane 22, which contact plane 22 is perpendicular to the axis 23 of the core 1. After the assembly composed of the core 1 and a pre-formed tubular body 9 wound on the core is set in the mold, the mold is brought to a position sufficient to make the thermosetting plastic material mother body (which belongs to The tubular body 9) causes the temperature of the network structure, for example, the temperature falls in a range from 80 ° C to 200 ° C. This temperature increase is preferably maintained for a period ranging from 30 minutes to 3 hours. In this way, the thermosetting mother body produces a reticular structure, while the elements 3, 4 forming the core 1 swell. Since the flanges 7, 8 are pressed by the two springs 21 and abut on the ends of the tubular body 9 formed in advance, this expansion is suppressed mainly radially outward. Therefore, a radial pressure is applied to the tubular body 9 outwardly, which is thus pushed out and abuts against the wall of the cylindrical recess 13. Although the composite profile of the body is exemplified herein (which has a bell-shaped end and a continuously increasing thickness from the center to the ends), in this way, a uniform pressure is applied to All parts of the tubular body 9 are formed in advance. Naturally, during this phase, the spring 21 -11-515762 V. Description of the invention (1G) enables the two elements 3, 4 of the core to follow the PTFE core against the ring flanges 7, 8 and They can be slightly separated by the applied force. The mold is opened and the assembly (which includes the core 1 and the body 9 formed thereon) is taken out at the end of the reticular stage. In this regard, the elements 3, 4 forming the core 1 are taken out of the body in opposite directions, thus forming a wheel hub according to the invention. The resulting hubs are particularly made of structural fiber material, typically carbon fiber material, and are made of a single part, despite the composite geometry as described above. Naturally, this product can be subjected to additional machining (for example, holes can be drilled in the two bell-shaped ends to form a set of radial holes to fix the spokes), which makes the part available for a pedal wheel hub. Naturally, various changes can be made to the structure and form of the examples of the present invention (which are incorporated into the features of the present invention, as defined in the scope of the following patent applications). For example, although this description and the drawings indicate a bicycle wheel hub, it is obvious that the method according to the present invention can be applied to make other parts with similar shapes, especially other bicycle parts. Therefore, these applications and the products they lead fall within the scope of the present invention. Explanation of symbols 1 Core 2 Part 3 Element 4 Element 5 Part -12- 515762 5. Description of the invention (11) 6 Part 7 Flange 8 Flange 9 Tubular body 10 Part 11 End 12 End 13 Recess 14 Equipment 15 mold 16 mold 19 screw 20 housing 20a tjzfe π back 21 spring 22 plane 23 shaft 50 tape / winding 5 1 tape / winding 52 pleated 53 pleated 54 pleated 55 pleated 56 tape 13-515762 Instructions (12) 57 tape 58 tape 59 tape 60 layer 61 layer -14-

Claims (1)

515762 g Amendment VI. Patent Application No. 90 1 27 276 "Method of Manufacturing Pedal Wheel Hub, Equipment for Implementing this Method and Wheel Hub Completed Due to It" Patent Case (Amended in March 2011) VI. Scope of Patent Application 1. A method for manufacturing a pedal wheel hub, which is characterized in that it comprises the following stages:-a cylindrical core (i) is provided, which is made of a synthetic material which will present a more than 5 X 10 · Coefficient of thermal expansion of 15mm / ° C and maximum continuous heat resistance at least equal to 80 ° C,-using many layers of structural fiber fabric, which are incorporated into a plastic matrix surrounding the core (1) to form a core surrounding the core (丨) a laminated tubular body (9) having a pre-formed shape and thickness,-setting the core (1) with the laminated tubular body (9) formed on the recess (13) of a mold (14) --Increase the temperature of the mold (1 4) to a number sufficient to cause the material forming the core (1) to swell, which is tied to the tubular body (9) in the mold (1 4) Exert a radial pressure and at the same time make the plastic The matrix of rubber material creates a reticulated structure, and the tubular body (9) is removed from the mold and from the core to complete a bicycle wheel hub formed from a single piece of structural fiber material. 2. The method according to item 1 of the patent application, wherein the core has a thermal expansion coefficient exceeding 9 X CT5mm / t and a maximum continuous heat resistance exceeding 100 ° C. 3. The method according to item 2 of the patent application, wherein The material forming the core is polytetrafluoroethylene (PTFE), or polyvinyl chloride trifluoride (PCTFE), or polyvinylidene fluoride (PVDF), or high density polyethylene (PE-HD). 515762 t. Patent application scope 4. The method of the third patent application scope, wherein the material forming the core is PTFE. 5. The method of claim 1 in which the structural fiber is a carbon fiber. 6. The method according to item 1 of the patent application, wherein the plastic material precursor is a thermosetting plastic material precursor. 7. The method according to item 1 of the patent application range, wherein the temperature falls within the range of 80 ° C to 20 ° C. 8. The method according to item 7 of the patent application range, wherein the temperature is maintained and continued from In the range of 30 minutes to 3 hours. 9. The method according to item 1 of the patent application range, wherein the core (1) presents a cylindrical central portion (2) and two wider diameter end portions (5, 6 ) And is composed of two separate, axially continuous elements (3, 4), which has a contact plane (22) perpendicular to the axis (23) of the core so that the core (1) (14) It can be separated from the tubular body (9) after being taken out. 10. The method according to item 9 of the scope of patent application, wherein the tubular body is formed so as to present a cylindrical central portion (10). And two enlarged end portions (i 1, 12). 11. According to the method of claim 10, wherein the tubular body (9) presents a direction from the central portion (10) toward the ends, Continuously increasing thickness 〇 12. The method according to item 9 of the scope of patent application, wherein the two elements (3, 4) forming the core (1) ) Has two end ring flanges (7, 8) which are used to axially restrict the ends of the pre-formed tubular body (9). -2- 515762 6. Scope of Patent Application 13. The method according to item 1 of the patent application scope, wherein the layers include a wrap of one or more fabric bands, which surrounds each larger diameter end of the core and the center Part, and many pleats that extend the entire length of the core, each pleat will partially cover the core in a peripheral direction and the pleats are applied on several faces of the core, To provide resistance to the structure in the axial direction. 14. An apparatus for manufacturing a wheel hub of a pedal wheel, characterized in that it comprises:-a mold (14) having a cylindrical recess (13),-a substantially cylindrical core (1), Made of a synthetic material that exhibits a thermal expansion coefficient of more than 5 X 10-15 mmrc and a maximum continuous heat resistance of at least 80 ° C, preferably PTGE, to which a number of layers of structural fiber fabric are applied to surround the The core (1) forms a laminated tubular body (9) having a predetermined shape and thickness, a device that brings the temperature of the laminated body (9) to a temperature sufficient to cause the plastic material matrix to form a mesh structure and to form the The material of the core (1) causes expansion to exert a radial pressure on the tubular body (9) in the mold, wherein the core (1) presents a cylindrical central portion (2) and two wider The diameter end portion (5, 6) is composed of two separate, axially continuous elements (3, 4), which has a contact plane (22) perpendicular to the axis (23) of the core (1) So that the core (1) can be used after the core is removed from the mold. The tubular body (9) is separated,-an elastic device (20) is used to elastically press the two elements (3, 4) forming the core (1) so that the two elements (3, 4) are tight with each other By the way, the element (3, 4) is combined with two end ring flanges (7, 8) which are used to axially restrict the tube 515762. 2. These ends of the scope of patent application (9). 15. The device as claimed in item 14 of the patent application, wherein the material forming the core is PTFE, or PCTFE, or PVDF, or PE-HD. 16. The device as claimed in item 14 of the patent application, wherein the material forming the core is PTFE. 17. The device as claimed in item 14 of the patent application scope, which includes a cylindrical recess (13) closed by two covers (17, 18), each of the two covers (17, 18) including a Individual spiral springs (21) are arranged axially between the cover (17, 18) and individual elements (3, 4) of the core (1). 18. A pedal wheel hub characterized in that it is completed by a method according to items 1 to 13 of the scope of patent application. 19. A pedal wheel hub, characterized in that it presents a tubular body (9) made of a single part, which has structural fibers incorporated into a plastic matrix and has a central cylindrical portion (1 0) and two wider diameter end sections (1, 1, 12). 20. For the pedal wheel hub of item 19 of the patent application scope, wherein the end portions (11, 12) are bell-shaped. 21. For example, the pedal hub of item 19 in the scope of patent application, wherein the thickness of the hub (9) is continuously increased from the central portion (10) toward the ends. 22. The bicycle wheel hub according to claim 19, wherein the structural fiber is carbon fiber. 23. If the pedal wheel hub of item 19 of the patent application scope, wherein the plastic material mother body is a thermosetting plastic material mother body '