CN111806147A - A kind of FSAE racing car composite material rim and its forming method - Google Patents

Abstract

The invention relates to an FSAE racing composite material rim and a molding method thereof, comprising an inner rim, an outer rim and a connecting disc. Installed on the end face of the inner rim, the outer rim and the inner rim are both made of fiber material, with a sandwich layer inside, the outer rim includes an outer rim body and a spoke integrally formed with the outer rim body, the spokes are The end portion is integrally connected with the connecting plate. Compared with the prior art, the invention makes the FSAE racing rim more lightweight, while ensuring the heat dissipation performance of the wheel brake disc, effectively reducing the unsprung mass of the racing car, and improving the lateral stiffness and impact resistance of the rim.

Description

A kind of FSAE racing car composite material rim and its forming method

technical field

The invention belongs to the technical field of FSAE formula racing cars, in particular to a FSAE racing car composite material rim and a molding method thereof.

Background technique

The Formula Student Competition (FSAE/Formula Student) is a car design and manufacturing competition that is teamed up by students in automotive engineering or related majors in colleges and universities, similar to the F1 competition for college students. Each participating team designs and manufactures a small formula car within one year in accordance with the competition rules and car manufacturing standards, and conducts a full range of dynamic and static competitions in terms of cost, marketing, design, acceleration, durability, fuel consumption, etc.

The light weight of the rim can effectively reduce the unsprung mass of the FSAE racing car, which plays a vital role in improving the handling stability of the racing car. At present, both aluminum alloy rims and magnesium alloy rims have been widely used in FSAE racing cars, and many rim manufacturers also take FSAE rims as part of the product development field. However, due to the high material price, complex process, and poor durability and fatigue resistance, composite rims have not been widely used in FSAE events, and there are very few companies and enterprises that use FSAE racing carbon fiber rims as a product development field.

In the prior art, the patent number CN101218110A published by DYMAG Racing Company, the patent name is the patent of "wheel", the rim is made of plastic, the spoke unit or the wheel disc is made of metal, and is arranged around the bottom of the rim according to the circumference. A plurality of connectors in the form of bolts are screwed into the threaded holes of the spoke unit or the wheel disc to form a rim; the patent number published by Beijing Nasheng New Material Technology Co., Ltd. is CN201420496310.2, and the patent name is "A kind of Long carbon fiber reinforced thermoplastic composite material automobile hub", which combines composite material with carbon fiber, and has the characteristics of high strength and good heat dissipation; the patent number published by CITIC Dicastal Co., Ltd. is CN205853745U, and the patent name is "a combination of Through the design of the anti-rotation ring structure, the contact area between the aluminum alloy and the composite material body is increased, and the problems of reduced tightening torque, low reliability and wheel failure are solved, but the processing method is more complicated; by Harbin Institute of Technology (Weihai) ) published patent number CN110254128A, the patent name is "a carbon fiber three-piece composite rim and its forming mold", the inner and outer rims are bonded by high-strength sealants, and the inner and outer rims and their molds are produced separately. The patent number published by Zhejiang University is CN207388741U, the patent name is the patent of "an integrated molding carbon fiber composite material rim", the integrated molding rim, the rim bottom and the spokes are all rounded transitions to avoid stress concentration, and the web Connect with the hub with continuous fiber, and use the groove structure to improve the connection between the spoke and the rim.

The structures and forming methods of these rims solve the structure and forming problems of the rims under specific working conditions to a certain extent, but there are few studies on the impact resistance of the rims, especially for the FSAE racing rims, which bear a higher lateral force than the rims. Large, and often alternating variable loads, the requirements for its lateral stiffness and impact resistance are particularly strict, and it is difficult to meet this demand.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a kind of FSAE racing car composite material rim and its molding method in order to solve the above problems, and under the premise of ensuring good brake heat dissipation performance, it has good lateral stiffness, impact resistance, and easy molding.

The object of the present invention is achieved through the following technical solutions:

An FSAE racing composite material rim, comprising an inner rim, an outer rim and a connecting disc, the inner rim is cylindrical, the outer rim is disc-shaped, and the outer rim is mounted on the end face of the inner rim through a connecting piece , the outer rim and the inner rim are both made of fiber material, with a sandwich layer inside, the outer rim includes an outer rim body and a spoke integrally formed with the outer rim body, and the ends of the spokes are connected to the connecting plate. Connect as one.

Further, the sandwich layer includes but is not limited to foam or honeycomb material, and forms a "sandwich" structure with the outer fiber layer, which enhances the lateral stiffness of the rim while reducing weight, and the fiber material is a mixture of carbon fiber and aramid fiber. , in which aramid fiber can significantly improve the impact resistance of the rim, and carbon fiber provides strength and stiffness.

Further, the spokes are short and wide, the number of spokes is 3-5, and elliptical openings are arranged between the spokes, and the elliptical openings can ensure the heat dissipation efficiency of the brake disc when the rim rotates.

The ends of the spokes are connected with the connecting plate through a mosaic structure, which can prevent the spokes and the connecting plate from playing under the rotational torque.

Further, the rim thickness of the inner rim and the outer rim edge is 6-8 mm, and the height of the rim is 10-15 mm, so as to ensure that the tire can withstand the lateral force transmitted to the inner side of the rim.

Further, the inner rim is also provided with a groove structure on the circumferential surface to facilitate the loading and unloading of tires, and the inner rim and the outer rim are also provided with 3-5mm bosses on the inner side of the rim to prevent extreme damage in racing cars. The tire dislodges from the rim under high lateral force.

Further, the outer rim is composed of an outer layer of fiber layup and an inner layer of an outer rim sandwich layer, the shape of the outer rim sandwich layer matches the contour of the outer rim body, and the fiber layup covers Outside the outer rim sandwich, the two combine to form the outer rim body.

Further, the spoke ends of the outer rim sandwich layer are provided with a wedge-shaped structure, and the circumference of the connecting disc is provided with a groove-shaped structure matching the wedge-shaped structure, and the two are inlaid and connected;

The end surface of the connecting plate is provided with a boss structure, and the fiber layup of the outer layer of the outer rim is overlapped on the boss structure on the surface of the connecting plate;

The connecting plate is made of aluminum, and the end face of the connecting plate is provided with a plurality of blind holes for connecting with the wheel spindle.

Further, the thickness of the fiber layup is 1-5mm, and the thickness of the fiber layup at the rim of the outer rim is not less than 3mm;

The fiber lay-up layer is bonded to the outer rim sandwich layer and the connecting plate through an epoxy resin film with a thickness of 0.2-0.3 mm.

Further, the inner rim is provided with a flange for bolting with the outer rim, and an inner rim sandwich layer for enhancing rigidity is laid inside the flange, and the thickness of the inner rim sandwich layer is 3- 5mm;

The outer rim is connected to the inner rim through titanium alloy bolts, and embedded parts are arranged in the bolt connection holes to prevent the bolts from causing wear to the structure.

A molding process for a new FSAE composite material rim, which specifically includes the following steps:

Step 1. According to the design requirements, the sandwich layer part of the inner rim and the outer rim is processed, and the embedded parts at the flange connection holes are processed at the same time;

Step 2: Lay carbon fiber and aramid fiber layup on the surface of the outer rim mold, and perform local reinforcement at the outer rim rim. For the connecting disk area, retain the fiber layup for overlapping with the connecting disk;

Step 3, laying epoxy resin film on the laid carbon fiber skin;

Step 4, laying an epoxy resin film on the outer surface of the connection plate mosaic structure and the embedded part, assembling and bonding it with the sandwich layer, and covering and bonding it on the laid outer rim carbon fiber layer;

Step 5, continue to lay carbon fiber and aramid fiber layup on the laid sandwich layer, and overlap with the layup laid in step 2 to close the layup;

Step 6: Lay the inner rim with the same method as in Steps 2 to 5, and the thickness of the layer varies according to different areas;

Step 7, sealing the laid preform and vacuuming;

Step 8: Put the finished product into the autoclave, carry out vacuuming inside the bag and pressure treatment with inert gas outside the bag at the same time, and heat and pressurize the product according to the curing curve of the epoxy resin used to make the product. curing molding;

Step 9, cooling and depressurizing, taking out the product from the autoclave, demoulding and taking out the product, and performing post-processing to obtain a finished product.

Compared with the existing invention, the present invention has the following advantages:

1. An FSAE racing composite rim is provided. Compared with the existing FSAE aluminum alloy and magnesium alloy rims, the unsprung mass of the racing car is greatly reduced and the dynamic performance of the racing car is improved. At the same time, there are oval openings between the rim spokes. It ensures the heat dissipation performance of the racing brake disc.

2. At the outer rim and the spokes of the present invention, the inner rim end face flange uses sandwich materials and fibers to form a "sandwich" structure, which reduces the weight and enhances the lateral rigidity of the rim; the ends of the spokes are provided with a wedge-shaped structure, while connecting the circumference of the disk A groove-shaped structure matching the wedge-shaped structure is provided on the upper part, and the swaying failure is prevented by assembling and bonding, and the reliability of the rim is enhanced;

3. Based on the excellent impact resistance properties of aramid fibers, the present invention mixes and lays aramid fibers into the carbon fiber layer according to a certain proportion, and makes up for its impact resistance on the basis of making full use of the high strength and lightweight advantages of carbon fiber composite materials. The disadvantage is that the impact resistance of the rim body is enhanced.

4. A method for forming FSAE rims is provided. The inner and outer rims are separately formed, which reduces the difficulty of mold processing and the difficulty of laying parts. The integral molding of the inner rim and the spokes makes the overall strength and rigidity higher. The connecting disc is overlapped to improve the reliability of the rim.

Description of drawings

1 is a schematic diagram of the overall structure of the assembled rim of the present invention;

Fig. 2 is the schematic diagram of rim explosion of the present invention;

Fig. 3 is the exploded schematic diagram of the outer rim and the connecting plate of the present invention;

Fig. 4 is the structural schematic diagram of the connection plate of the present invention;

Fig. 5 is the structural schematic diagram of the outer rim sandwich layer of the present invention;

Fig. 6 is the structural representation of outer rim fiber layup of the present invention;

Figures 7, 8 and 9 are schematic diagrams of the assembly structure of the connecting plate and the outer rim sandwich layer of the present invention;

Figure 10 is a schematic diagram of the circumferential structure of the rim of the present invention;

Figure 11 is a partial cross-sectional view of the outer rim of the present invention.

In the picture: 1-inner rim, 2-outer rim, 3-connecting plate, 4-epoxy resin film, 5-embedded part, 101-inner rim sandwich layer, 102-rim, 103-boss, 104 - groove structure, 201 - fiber layup, 202 - outer rim sandwich, 203 - wedge structure, 301 - groove structure.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

Example

As shown in Figures 1 and 2, an FSAE racing composite material rim includes an inner rim 1, an outer rim 2 and a connecting disc 3, the inner rim 1 is cylindrical, the outer rim 2 is disc-shaped, and the outer rim 2 is installed by connecting pieces The end face of the inner rim 1, the outer rim 2 and the inner rim 1 are both made of fiber material, with a sandwich layer inside, and the outer rim 2 includes the outer rim body and the spokes integrally formed with the outer rim body, the ends of the spokes and the connecting disc 3 connected as one. Wherein, the sandwich layer includes but is not limited to foam or honeycomb material, and the fiber material is carbon fiber or aramid fiber.

As shown in Figure 3, the spokes are short and wide, the number of spokes is 3 to 5, and there are elliptical openings between the spokes. The elliptical openings can ensure the heat dissipation efficiency of the brake disc when the rim rotates, as shown in Figures 7 and 8. The ends of the spokes and the connecting plate 3 are connected by a mosaic structure, which can prevent the spokes and the connecting plate 3 from playing under the rotational torque.

As shown in Figure 10, the thickness of the rim 102 on the edge of the inner rim 1 and the outer rim 2 is 6-10mm, and the height of the rim 102 is 10-12mm to ensure that it can withstand the lateral force transmitted by the tire to the inside of the rim, and the circumference of the inner rim 1 is 10-12mm. There is also a groove structure 104 on the surface to facilitate the loading and unloading of the tire, and the inner rim 1 and the outer rim 2 are also provided with a 3-5mm boss 103 on the inner side of the rim 102 to prevent the tire from falling under the extreme lateral force of the racing car. Out of the rim.

As shown in Figures 3, 5, and 6, the outer rim 2 is composed of an outer fiber layer 201 and an inner outer rim sandwich layer 202. The shape of the outer rim sandwich layer 202 matches the contour of the outer rim body, and the fiber layer 201 Covered on the outside of the outer rim sandwich layer 202, the two are combined to form the outer rim body.

As shown in FIG. 9 , the ends of the spokes of the outer rim sandwich layer 202 are provided with a wedge-shaped structure 203 , as shown in FIG. 4 , a groove-shaped structure 301 matching the wedge-shaped structure 203 is provided on the circumference of the connecting disc 3 , and the two are inlaid and connected, as shown in FIG. 7 . 8. The end face of the connecting plate 3 is provided with a boss structure, the outer layer of the outer rim 2 is lapped on the boss structure on the surface of the connecting plate 3, the connecting plate 3 is made of aluminum, and the end face of the connecting plate 3 is provided with a plurality of Blind hole for connection to the wheel spindle. The thickness of the fiber layup 201 is 1-5mm, and the thickness of the fiber layup 201 at the rim of the outer rim 2 is not less than 3mm; as shown in Figure 11, the fiber layup 201 passes through the epoxy resin film 4 with a thickness of 0.2~0.3mm. The rim sandwich layer 202 and the connecting plate 3 are bonded.

As shown in Figure 2, the inner rim 1 is provided with a flange for bolting with the outer rim 2, the inner rim sandwich layer 101 for enhancing rigidity is laid inside the flange, and the thickness of the inner rim sandwich layer 101 is 3-5mm; The rim 2 is connected to the inner rim 1 through titanium alloy bolts, and embedded parts 5 are arranged in the bolt connection holes to prevent the bolts from causing wear to the structure.

The above-mentioned carbon fiber rim production process includes the following steps:

Step 1, according to the design requirements, process the core material 4 at the inner rim flange and the core material 5 at the outer rim spokes, and at the same time process the embedded parts at the flange connection holes;

Step 2: Lay a carbon fiber layer of not less than 1mm on the surface of the outer rim mold, and perform local reinforcement at the outer rim rim to make its thickness not less than 3mm. In particular, for the connecting plate area, keep a carbon fiber layer of 1mm thickness. For lap joint with connecting plate;

Step 3, laying an epoxy resin film 7 with a thickness of 0.2 to 0.3 mm on the laid carbon fiber skin;

Step 4: Lay a 0.2-0.3mm adhesive film 7 on the inlaid structure of the aluminum connecting plate 3 and the outer surface of the embedded part, and assemble and connect it with the sandwich material 4, cover and bond it to the outer surface of the laid outer rim 2. on carbon fiber skin;

Step 5: Continue to lay a carbon fiber layup no less than 2 mm on the laid inner rim sandwich material 4, and close the layup.

Step 6: Lay the inner rim with the same method as in Steps 2 to 5, and the thickness of the layer varies according to different areas;

Step 7, sealing the laid preform and vacuuming;

Step 8: Put the finished product into the autoclave, carry out vacuuming inside the bag and pressure treatment with inert gas outside the bag at the same time, and heat and pressurize the product according to the curing curve of the epoxy resin used to make the product. curing molding;

Step 9, cooling and depressurizing, taking out the product from the autoclave, demoulding and taking out the product, and performing post-processing to obtain a finished product.

In this embodiment, the carbon fiber material used is a prepreg material of type T700 with a gram weight of 220 g/m ² , and the aramid fiber is a prepreg material of type Kevlar-49 with a gram weight of 200 g/m ² . The two materials are mixed and laid in an area ratio of about 3:1, but in different structures, the material ratio should be different to give full play to the material properties.

In this embodiment, the mass of the obtained composite rim is 1.83kg, which is about 40% lighter than that of the aluminum alloy rim, and about 19.3% lighter than that of the magnesium alloy rim, and the lightweight effect is obvious; the lateral stiffness is 3406.98N/mm, which can meet the FSAE requirements. The working conditions of the racing car.

The foregoing description of the embodiments is provided to facilitate understanding and use of the invention by those of ordinary skill in the art. It will be apparent to those skilled in the art that various modifications to these embodiments can be readily made, and the generic principles described herein can be applied to other embodiments without inventive step. Therefore, the present invention is not limited to the above-mentioned embodiments, and improvements and modifications made by those skilled in the art according to the disclosure of the present invention without departing from the scope of the present invention should all fall within the protection scope of the present invention.

Claims (10)

1. The utility model provides a FSAE cycle racing combined material rim, includes interior rim (1), outer rim (2) and connection pad (3), interior rim (1) is cylindric, outer rim (2) are discoid, outer rim (2) are installed through the connecting piece interior rim (1) terminal surface, its characterized in that, outer rim (2) are made by the fibre material with interior rim (1), and inside is equipped with sandwich layer, outer rim (2) include outer rim body and with outer rim body integrated into one piece's spoke, the tip of spoke with connection pad (3) are connected as an organic wholely.

2. The FSAE racing composite rim of claim 1, wherein the sandwich layer comprises but is not limited to foam or honeycomb material, and the fiber material is a mixture of carbon fiber and aramid fiber.

3. The FSAE racing composite rim as claimed in claim 1, wherein the spokes are short and wide, the number of the spokes is 3-5, and oval holes are formed between the spokes;

the tail end of the spoke is connected with the connecting disc (3) through an embedded structure.

4. An FSAE racing composite rim according to claim 1, characterized in that the thickness of the rim (102) of the edges of the inner rim (1) and the outer rim (2) is 6-8mm, and the height of the rim (102) is 10-15 mm.

5. An FSAE racing composite rim according to claim 4, characterized in that the inner rim (1) is provided with a groove structure (104) on the circumferential surface for facilitating tire loading and unloading, and the inner rim (1) and the outer rim (2) are provided with a boss (103) of 3-5mm on the inner side of the wheel flange (102).

6. An FSAE racing composite rim according to any one of claims 1 to 5, wherein the outer rim (2) is composed of an outer layer of fibre lay-up (201) and an inner layer of outer rim sandwich layer (202), the outer rim sandwich layer (202) is shaped to match the profile of the outer rim body, the fibre lay-up (201) is coated on the outside of the outer rim sandwich layer (202), and the two are combined to form the outer rim body.

7. An FSAE racing composite rim according to claim 6, characterized in that the end of the spoke of the outer rim sandwich layer (202) is provided with a wedge-shaped structure (203), the circumference of the connecting disc (3) is provided with a groove-shaped structure (301) matched with the wedge-shaped structure (203), and the wedge-shaped structure and the groove-shaped structure are connected in an embedded mode;

a boss structure is arranged on the end face of the connecting disc (3), and a fiber laying layer of the outer rim (2) is lapped on the boss structure on the surface of the connecting disc (3);

the connecting disc (3) is made of aluminum, and a plurality of blind holes are formed in the end face of the connecting disc (3) and used for being connected with a wheel spindle.

8. An FSAE racing composite rim according to claim 7, characterized in that the thickness of the fiber lay-up (201) is 1-5mm, the thickness of the fiber lay-up (201) at the rim of the outer rim (2) is not less than 3 mm;

the fiber laying layer (201) is bonded with the outer rim sandwich layer (202) and the connecting disc (3) through an epoxy resin adhesive film (4) with the thickness of 0.2-0.3 mm.

9. An FSAE racing composite rim according to claim 1, characterized in that the inner rim (1) is provided with a flange for bolting with the outer rim (2), an inner rim sandwich layer (101) for enhancing rigidity is laid inside the flange, and the thickness of the inner rim sandwich layer (101) is 3-5 mm;

the outer rim (2) is connected with the inner rim (1) through titanium alloy bolts, and embedded parts are arranged in the bolt connecting holes.

10. A forming process of an FSAE novel composite material rim is characterized by comprising the following steps:

step 1, machining sandwich layers of an inner rim and an outer rim according to design requirements, and simultaneously machining embedded parts at flange connecting holes;

step 2, laying a carbon fiber and aramid fiber laying layer on the surface of an outer rim die, carrying out local reinforcement on the rim of the outer rim, and reserving the fiber laying layer for lapping with a connecting disc in the area of the connecting disc;

step 3, paving an epoxy resin adhesive film on the paved carbon fiber skin;

step 4, laying an epoxy resin adhesive film on the outer surfaces of the connecting disc embedded structure and the embedded part, assembling and bonding the adhesive film and the sandwich layer part, and covering and bonding the adhesive film and the sandwich layer part on the laid outer rim carbon fiber laying layer;

step 5, continuously paving carbon fiber and aramid fiber paving layers on the paved sandwich layer, and lapping with the paving layer paved in the step 2 to close the paving layer;

step 6, paving the inner rim by the same method as the steps 2-5, wherein the thickness of the paving layer is different according to different areas;

step 7, sealing the laid preforms, and vacuumizing;

step 8, putting the packaged workpiece into a hot-pressing tank, simultaneously carrying out vacuumizing in the bag and pressurizing treatment of inert gas outside the bag, and simultaneously carrying out heating and pressurizing treatment according to a curing curve of the used epoxy resin to cure and mold the workpiece;

and 9, cooling and releasing pressure, taking the product out of the hot-pressing tank, demolding, taking the product out, and performing post-treatment to obtain a finished product.

Images