TWI715442B - Method of manufacturing wheel rim - Google Patents

Abstract

A method of manufacturing a wheel rim is described. The method includes the following steps. Plural core mold units are formed by a water-soluble material, in which each of the core mold units has a joint structure. The core mold units are jointed together by the joint structures to form a wheel rim core. A fiber-reinforced prepreg is wrapped around the wheel rim core. The wheel rim core is heated and baked to harden the fiber-reinforced prepreg. The wheel rim core is dissolved to obtain a finished product of the wheel rim.

Description

How to make the wheel frame

The present invention relates to a manufacturing method of a wheel frame, and particularly relates to a manufacturing method of a wheel frame with high forming accuracy.

The current common bicycle frame or wheel frame is made of a composite material formed of resin and fiber in order to achieve the purpose of being light and strong. Generally speaking, resin fiber composite materials are mainly composed of fibers and resins. The resin can be epoxy resin or unsaturated resin, and the fibers can be glass fiber or carbon fiber. Among them, carbon fiber is a fiber material with both chemical inertness and semiconductor properties. Compared with ordinary metals, it has light weight, high strength, high elastic modulus, high temperature resistance, acid resistance, strong electrical conductivity, and no potential for long-term stress. It has excellent properties such as deformation, fatigue resistance, strong dimensional stability, high thermal conductivity, low friction coefficient, and lubricity, so it is often used to make high-strength resin fiber composite materials.

One of the common methods for making wheel frames is air bag forming. The air bag forming method is mainly to inflate the air bag to form the shape of the rim, then wind the prepreg made of resin and fiber around the air bag, and then heat the wrapped resin fiber prepreg to cure the resin The shape of the wheel frame is formed, and then surface treatments such as trimming and polishing are performed to form the finished wheel frame.

However, the air bag forming method has many shortcomings in operation: (1) The air bag forming method cannot form workpieces with more complicated shapes; (2) When the prepreg is wound on the air bag, if the winding force is not uniform, the final The size of the finished product varies, so it is not suitable for making products that require high dimensional accuracy, such as wheel frames; (3) The mechanical strength of the air bag itself is poor, and the heating process after the prepreg is wound will cause damage to the product Defects; (4) If the gas pressure inside the air bag is not uniformly distributed during the heating process, it will also cause the final product size to vary.

Therefore, in order to improve the shortcomings of the traditional air bag forming method, someone has proposed a self-heating expansion pressure bag forming fiber composite material method, which is to fill the air bag with a mixture of thermally expandable microsphere foaming agent, quicklime and water. In addition to heating the quicklime, water can also cause the foaming agent to produce a foaming reaction. Therefore, foaming through the foaming agent can replace the gas to increase the rigidity of the air bag, and the heat generated through the quicklime can also help the curing of the resin fiber prepreg. However, this method still has disadvantages. For example, if the foaming agent is unevenly distributed, it will also cause the size of the final product to vary, and applying stress on the inside and outside of the air bag at the same time may easily break the air bag.

Another way to improve the shortcomings of the traditional air bag forming method is to use a 3D three-dimensional air bag to form a resin fiber composite material with a complex shape. However, this method still has problems such as poor accuracy of the final product due to the inability to grasp the winding force of the traditional air bag or the uneven gas pressure distribution inside the air bag.

Therefore, an object of the present invention is to provide a method for manufacturing a wheel frame to solve the problem of poor molding accuracy caused by the air bag molding method.

According to the above objective of the present invention, a method for manufacturing the wheel frame is proposed. The manufacturing method of this wheel frame includes the following steps. A plurality of core mold units are formed by using water-soluble materials, and each of the core mold units has an overlapping structure. The core mold units are overlapped with each other by using the overlap structure to form the wheel frame core mold. Wrap the resin fiber prepreg on the wheel core mold. The rim core mold is heated and baked to cure the resin fiber prepreg. Melt the rim core mold so that the resin fiber prepreg from the rim core mold is removed to form a finished rim.

According to an embodiment of the present invention, the aforementioned step of forming a core mold unit using a water-soluble material includes: using a graphite mold to form a core mold unit from the water-soluble material.

According to an embodiment of the present invention, the aforementioned step of using a graphite mold to form a core mold unit with a water-soluble material includes: injecting the water-soluble material into the graphite mold, and performing a vacuuming step or a heating step on the graphite mold to make the graphite mold The water in the water-soluble material disperses and escapes to form several core mold units.

According to an embodiment of the present invention, the above-mentioned vacuuming step and heating step are performed at a temperature of 60°C to 110°C.

According to an embodiment of the present invention, the above-mentioned graphite mold has a plurality of pores and has a partial shape of the finished wheel frame.

According to an embodiment of the present invention, each of the above-mentioned overlapping structures includes protrusions and grooves formed at opposite ends of each core mold unit.

According to an embodiment of the present invention, before the step of melting the wheel frame core mold, the aforementioned manufacturing method further includes drilling a hole on the surface of the cured resin fiber prepreg to expose the wheel frame core mold.

It can be seen from the above-mentioned embodiments of the present disclosure that the wheel frame core mold of the present disclosure is mainly formed by splicing core mold units formed by water-soluble materials, so it has a certain degree of rigidity and can be used as a resin fiber prepreg for winding. The mold is conducive to accurately controlling the shape of the fiber prepreg while winding the resin fiber prepreg. In addition, the rim core mold made of water-soluble materials can be dissolved and removed by water after the resin fiber prepreg is cured, and will not remain on the finished rim, which contributes to the weight reduction of the rim. Moreover, the wheel frame core mold of the present disclosure is formed by splicing a plurality of core mold units, so the size and weight of the mold for making the core mold unit are relatively small, and the operability is high, and it is easy to realize mass production.

Please refer to FIGS. 1 and 2 at the same time. FIG. 1 is a flowchart of a method for manufacturing a wheel frame according to the present disclosure, and FIG. 2 is a schematic diagram of a lap process of a core mold unit according to the present disclosure. In the manufacturing method 100 of the wheel frame of this embodiment, step 110 is first performed to form several core mold units 200 as shown in FIG. 2 using water-soluble materials. Specifically, in step 110, the upper mold 310 and the lower mold 320 as shown in FIGS. 3A and 3B can be used to form the core mold unit 200 together.

Please refer to FIGS. 3A and 3B together. FIGS. 3A and 3B are schematic diagrams of the upper and lower molds of a core mold unit manufactured according to the present disclosure. In this embodiment, the upper mold 310 and the lower mold 320 are graphite molds with pores, and the water-soluble material may be an aqueous starch solution or other water-soluble polymer materials. Wherein, the upper mold 310 and the lower mold 320 have the partial shape of the desired wheel frame product. In one example, when designing the corresponding opening shapes of the upper mold 310 and the lower mold 320, the finished wheel frame can be used as a reference first, and the finished wheel frame can be divided into several equal parts along the circumferential direction, and then these etc. The shape of one of them is used as the mold opening shape of the upper mold 310 and the lower mold 320. Therefore, the core mold unit 200 made by the upper mold 310 and the lower mold 320 can form a complete wheel frame shape after being spliced with each other.

In an example, assuming that a wheel frame with a diameter of about 571 mm to 622 mm and a width of about 2.5 mm to 4.5 mm needs to be produced, only a mold with a volume of about 250x120x100mm and a weight of less than 5 kg is needed to make multiple core mold units. In addition to the amount of graphite material required by the mold itself, it also has the advantages of good operability and mass production.

In one embodiment, when step 110 is performed, the upper mold 310 and the lower mold 320 may be combined with each other first. In one example, the corners of the upper mold 310 and the lower mold 320 may be respectively provided with positioning pins 312 and positioning holes 321 that are butted with each other, so that the upper mold 310 and the lower mold 320 can be accurately butted when being combined. After the upper mold 310 and the lower mold 320 are merged with each other, the water-soluble material can be injected from the channel 311 of the upper mold 310 into the space formed by the upper mold 310 and the lower mold 320, and then the upper mold 310 and the lower mold 320 are combined. A vacuuming step or a heating step allows the water in the water-soluble materials in the upper mold 310 and the lower mold 320 to escape through the pores of the upper mold 310 and the lower mold 320 to form the core mold unit 200. In one embodiment, the vacuuming step and the heating step are performed at a temperature of 60°C to 110°C. In one example, the vacuuming step and the heating step can be performed at a temperature of 85°C. In one example, the vacuuming step and the heating step can be performed in a vacuum box or a circulating oven. Since the upper mold 310 and the lower mold 320 are graphite molds, placing the graphite mold in a heated environment or a negative pressure environment can accelerate the escape of water in the water-soluble material in the graphite mold from the pores of the graphite mold.

Please refer to FIGS. 1 and 2 again. After step 110 is performed, step 120 is performed to overlap the core mold units 200 with each other to form a wheel frame core mold. In this embodiment, each core mold unit 200 has an overlap structure 210, and the overlap structure 210 includes protrusions 211 and grooves 212 formed at opposite ends of each core mold unit 200. Thereby, by inserting the protrusion 211 of one of the core mold units 200 into the groove 212 of the adjacent core mold unit 200, the purpose of overlapping multiple core mold units 200 can be achieved, and the multiple core mold units 200 Overlap to form a complete wheel frame shape to serve as a wheel frame core mold. In other examples, the overlapping structure 210 is not limited to the design of the protrusion and the groove. For example, a tenon structure can be used to assemble multiple core mold units 200.

After the wheel frame core mold is obtained, step 130 can be followed to wind the resin fiber prepreg on the wheel frame core mold. Specifically, in step 130, the rim core mold made of water-soluble material is used as the inner mold for the resin fiber prepreg to wind, and the rim core mold made of water-soluble material is rigid, so When the resin fiber prepreg is wound on the core mold of the wheel frame, the problem of using an air bag to control the winding force and shape of the resin fiber prepreg as described in the prior art will not occur, so the resin fiber prepreg can be made Accurately fit on the wheel core mold.

After step 130 is completed, step 140 may be performed to heat and bake the core mold of the wheel frame wrapped with the resin fiber prepreg to cure the resin fiber prepreg to form the shape of the wheel frame.

After the resin fiber prepreg is cured, step 150 is then performed to melt the wheel frame core mold. In step 150, a hole may be drilled on the surface of the cured resin fiber prepreg to expose the wheel frame core mold. Then, water is poured into the holes of the resin fiber prepreg to dissolve and remove the rim core mold. After the core mold of the wheel frame is removed, the finished wheel frame can be obtained.

It can be seen from the above-mentioned embodiments of the present disclosure that the wheel frame core mold of the present disclosure is mainly formed by splicing core mold units formed by water-soluble materials, so it has a certain degree of rigidity and can be used as a resin fiber prepreg for winding. The mold is conducive to accurately controlling the shape of the fiber prepreg while winding the resin fiber prepreg. In addition, the rim core mold made of water-soluble materials can be dissolved and removed by water after the resin fiber prepreg is cured, and will not remain on the finished rim, which contributes to the weight reduction of the rim. Moreover, the wheel frame core mold of the present disclosure is formed by splicing a plurality of core mold units, so the size and weight of the mold for making the core mold unit are relatively small, and the operability is high, and it is easy to realize mass production.

100: How to make the wheel frame 110: Step 120: Step 130: steps 140: Step 150: step 200: Mandrel unit 210: lap structure 211: convex column 212: Groove 310: Upper mold 311: Channel 312: positioning pin 320: Lower mold 321: positioning hole

For a more complete understanding of the embodiments and their advantages, reference is now made to the following description in conjunction with the accompanying drawings, in which: [Figure 1] is a flow chart showing a method of making a wheel frame according to this disclosure; [Figure 2] is a schematic diagram showing the overlapping process of a core mold unit according to the present disclosure; and [Fig. 3A] and [Fig. 3B] are schematic diagrams showing the upper and lower molds of a core mold unit manufactured according to the present disclosure.

Domestic deposit information (please note in the order of deposit institution, date and number) no Foreign hosting information (please note in the order of hosting country, institution, date and number) no

100: How to make the wheel frame

110: Step

120: Step

130: steps

140: Step

150: step

Claims (6)

A method for manufacturing a wheel frame includes: forming a plurality of core mold units from a water-soluble material using a graphite mold, wherein each of the core mold units has an overlapping structure; using the overlapping structures to form the core mold units The units overlap each other to form a wheel frame core mold; a resin fiber prepreg cloth is wound on the wheel frame core mold, and the resin fiber prepreg cloth is directly attached to the wheel frame core mold; The core mold undergoes a heating and baking step to cure the resin fiber prepreg; and melts the wheel frame core mold to obtain a finished wheel frame. The manufacturing method of the wheel frame according to claim 1, wherein using the graphite mold to form the water-soluble material into the core mold units comprises: injecting the water-soluble material into the graphite mold; and vacuuming the graphite mold Step or a heating step to disperse and escape the water in the water-soluble material in the graphite mold to form the core mold units. The manufacturing method of the wheel frame according to claim 2, wherein the vacuuming step and the heating step are performed at a temperature of 60°C to 110°C. The manufacturing method of the wheel frame as described in claim 1, wherein the The graphite mold has a plurality of pores and has a partial shape of the finished wheel frame. The manufacturing method of the wheel frame according to claim 1, wherein each of the overlapping structures includes a protrusion and a groove formed at opposite ends of each of the core mold units. The manufacturing method of the wheel frame according to claim 1, wherein before the step of melting the wheel frame core mold, the manufacturing method further comprises drilling a hole on the surface of the cured resin fiber prepreg to expose the wheel frame core mold .

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