A wheel rim with alternating high and low points on the side wall and a wheel rim set

Abstract

The present invention provides a wheel rim and a wheel rim set with a side wall having alternating high and low points of a curved surface, comprising: a wheel rim body, comprising an inner ring and an outer ring arranged opposite to the inner ring, the inner ring being used to install a spoke structure, the outer ring being used to install a tire, and a curved surface structure having an alternating annular array of high points and low points of the curved surface arranged on the side wall between the inner ring and the outer ring. The present invention can utilize aerodynamic characteristics to reduce the air resistance of the wheel rim body during high-speed movement, thereby improving the wind-breaking effect of the wheel rim body at various yaw angles by setting a curved surface structure having an alternating annular array of high points and low points of the curved surface arranged on the side wall between the inner ring and the outer ring.

Description

Technical Field

[0001] The invention relates to a wheel rim with a side wall having alternately distributed high and low points in a curved surface and a wheel rim set, and is applied to the field of bicycle wheel rims. Background Art

[0002] Bicycle wheels are an important part of a bicycle, which directly affects the efficiency, speed and comfort of riding. The wheel set is composed of multiple parts, each of which has its specific functions and characteristics: The rim is the supporting structure of the tire, usually made of metal, carbon fiber or other composite materials. Aluminum rims are widely used because of their light weight and low cost, while carbon rims are favored by professional riders because of their light weight and high strength.

[0003] Existing bicycle rims usually have a curved surface structure on the inner ring of the bicycle rim. The bicycle rims configured in this way do not have a good wind-breaking effect, especially when the yaw angle (the yaw angle of the bicycle rim refers to the angle between the forward direction of the wheel and the incoming wind direction. In actual riding, due to the influence of factors such as side wind and vehicle speed, the wheel will be in different yaw angle states, which will have a significant impact on the aerodynamic performance of the wheel) is other angles, the wind-breaking effect is not good. In order to improve the wind-breaking effect of the rim, the present invention designs a rim and a rim wheel set with a side wall having alternating high and low points of a curved surface. Summary of the invention

[0004] The present invention provides a wheel rim and a wheel rim set with a curved side wall having high and low points alternately distributed, which can effectively solve the above-mentioned problem.

[0005] The present invention is achieved in that: A wheel rim with a curved side wall and alternating high and low points, comprising: The rim body includes an inner ring and an outer ring arranged opposite to the inner ring, the inner ring is used to install the spoke structure, the outer ring is used to install the tire, and the side wall between the inner ring and the outer ring is arranged with a curved surface structure with an alternating ring array of curved surface high points and curved surface low points.

[0006] The beneficial effect of the present invention is that: by setting a curved surface structure with an alternating ring array of high points and low points on the side wall between the inner ring and the outer ring, the present invention can utilize aerodynamic characteristics to reduce the air resistance of the wheel rim body during high-speed movement, thereby improving the wind-breaking effect of the wheel rim body at various yaw angles. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0008] Figure 1 It is a structural schematic diagram provided by an embodiment of the present invention.

[0009] Figure 2 yes Figure 1 Schematic diagram of the cross-sectional structure at point A in FIG.

[0010] Figure 3 yes Figure 1 Schematic diagram of the cross-sectional structure at point B in the figure.

[0011] Figure 4 It is a schematic diagram of the cross-sectional structure of the side wall when unfolded provided by an embodiment of the present invention.

[0012] Figures 5 and 6 It is an analysis diagram of the drag and drag coefficient of the comparative example provided by the present invention at a yaw angle of 0 degrees.

[0013] Figure 7-8 It is an analysis diagram of the drag and drag coefficient of the comparative example provided by the present invention at a yaw angle of 5 degrees.

[0014] Figures 9-10 It is an analysis diagram of the drag and drag coefficient of the comparative example provided by the present invention at a yaw angle of 10 degrees.

[0015] Figures 11-12 It is an analysis diagram of the drag and drag coefficient of the comparative example provided by the present invention at a yaw angle of 15 degrees.

[0016] Figures 13 and 14 It is an analysis diagram of the drag and drag coefficient of the comparative example provided by the present invention at a yaw angle of 20 degrees.

[0017] Figures 15 and 16 It is an analysis diagram of the drag and drag coefficient of the embodiment provided by the present invention at a yaw angle of 0 degrees.

[0018] Figures 17 and 18 It is an analysis diagram of the drag and drag coefficient of the embodiment provided by the present invention at a yaw angle of 5 degrees.

[0019] Figures 19 and 20 It is an analysis diagram of the drag and drag coefficient of the embodiment provided by the present invention at a yaw angle of 10 degrees.

[0020] Figures 21 and 22It is an analysis diagram of the drag and drag coefficient of the embodiment provided by the present invention at a yaw angle of 15 degrees.

[0021] Figure 23-24 It is an analysis diagram of the drag and drag coefficient of the embodiment provided by the present invention at a yaw angle of 20 degrees.

[0022] The accompanying drawings are marked as follows: 10. Rim body; 11. Inner ring; 12. Outer ring; 13. Curved surface structure; 131. High point of curved surface; 132. Low point of curved surface; 14. Spoke mounting hole. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the invention claimed for protection, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0024] Reference Figures 1 to 4 As shown, a wheel rim with a side wall having a curved surface with high and low points alternately distributed, comprising: The wheel rim body 10 includes an inner ring 11 and an outer ring 12 arranged opposite to the inner ring 11, wherein the inner ring 11 is used to install the spoke structure, and the outer ring 12 is used to install the tire. The side wall between the inner ring 11 and the outer ring 12 is provided with a curved surface structure 13 with an alternating annular array of curved surface high points 131 and curved surface low points 132.

[0025] The cross section of the side wall of the wheel rim body 10 along its axial direction satisfies the function expression of the first curve. The function expression of the first curve is y=ax²+bx+c (a≠0), which can improve the wind-breaking effect of the wheel rim body 10 without affecting the strength of the wheel rim body 10. It should be noted that y and x in the parabola expression may be replaced by different letters depending on the position and plane of the parabola. Moreover, x in the expression only represents the independent variable, and y only represents the dependent variable, which has nothing to do with the coordinates xyz.

[0026] The cross-sectional height of the side wall of the wheel rim body 10 along its axial direction is defined as , then the height of the high point 131 and the low point 132 of the surface from the bottom of the inner circle 11 =1 / 4~1 / 3 In this embodiment, the height of the high point 131 and the low point 132 of the curved surface from the bottom of the inner circle 11 is =1 / 3 The advantage of such a setting is that the curved surface structure 13 is located at the bottom side wall of the rim body 10, so that the curved surface structure 13 and the radial direction of the rim body 10 form a certain angle, and when the yaw angle is other angles (not 0°), the wind-breaking effect of the curved surface structure 13 is the best.

[0027] After the wheel rim body 10 is unfolded along its radial cross section, the vertical cross section of the curved surface structure 13 along its length direction satisfies the function expression of the second curve. The function expression of the second curve is: , where A is the amplitude factor, and L is the period of the second curve. The function curve is composed of an approximate brachistodes curve. The actual brachistodes curve cannot be simply obtained by inverting the sine function in each period. Therefore, the function is an approximate brachistodes curve function. The function curve can not only achieve a good wind-breaking effect similar to the brachistodes curve, but also ensure a smooth transition of the curve, thereby further improving the wind-breaking effect. By setting the second curve, during the rotation of the wheel, the aerodynamic characteristics are utilized to reduce the air resistance of the wheel rim body 10 during high-speed movement, thereby improving the wind-breaking effect. It should be noted that the direction of the second curve in this case is not limited to the direction set in this case. At the same time, although the lines similar to the brachistodes curve in this case, such as hand-drawn lines, multi-segment lines and spline lines, do not meet the brachistodes curve and parabolic function expressions, they can still play a similar role in accelerating the oil return speed due to the approximate drawing. The curve is constructed according to the following method: First, we know that the equation for a single brachistocentre line (starting from the origin in the horizontal direction) can be expressed as: y=

[0028] Where g is the acceleration due to gravity and x is the horizontal displacement.

[0029] Second, we can use sine or cosine functions to create periodicity, and adjust their parameters to ensure smoothness of the curve, using functions of the following form:

[0030] Where f(x) is a periodic function and A is the amplitude factor.

[0031] In order to make the curve rise and fall alternately, we can define f(x) as follows: =

[0032] where L is the period of the second curve.

[0033] Substituting f(x) into y(x), we get:

[0034] Finally, we introduce a symbolic function sgn to implement it:

[0035] Here sgn(x) is the sign function, which returns 1 if x is positive, -1 if x is negative, and 0 if x is zero.

[0036] The final function y(x)y represents a second curve composed of alternating brachistom lines, which alternately rises and falls in each period L while maintaining smoothness. Figures 5 to 24 As shown, the present invention verifies the wind-breaking effect of the wheel rim body 10 having the curved surface structure 13 through the following simulation experiment: First, the product parameters of this embodiment and the comparative example are as follows: Table 1 Product parameter comparison table

[0037] The drag coefficient and drag simulation experiments of the wheel rim are carried out according to different yaw angles. The yaw angles selected in this embodiment are 0, 5, 10, 15, and 20 degrees. The verification results are as follows: Table 2 Comparative Example Experimental Data Table

[0038] Table 3 Experimental data table of this embodiment

[0039] The following results were obtained by integrating the data: Table 4 Comparison of integrated experimental data

[0040] The experimental conclusion is: from the perspective of drag coefficient optimization, the wheel rim in this embodiment has the most significant optimization effect at a yaw angle of 0 degrees, and also has good aerodynamic structural advantages at yaw angles of 10 and 20 degrees. From the perspective of drag, at a large yaw angle, the wheel rim in this embodiment has a more prominent advantage and is more suitable for attacking when there is a crosswind, with an advantage of more than 4%. And when the frontal area is larger than that of an ordinary wheel, the final drag is smaller than that of an ordinary wheel. The wheel rim design of this embodiment meets the design requirements for optimizing the aerodynamic structure.

[0041] As a further improvement, a plurality of spoke mounting holes 14 are provided in an annular array on the side wall of the inner ring 11, and the spoke mounting holes 14 are used to mount spokes, and each spoke mounting hole 14 is located at a curved surface high point 131 of the curved surface structure 13 on the inner ring 11. By utilizing the wide feature of the spoke mounting portion between the curved surface high points of the two annular side walls, the machining surface of the spoke mounting hole 14 can be made larger and flatter, making it easier to machine the spoke mounting holes, making it more convenient to install spokes, and avoiding the problem of skewness of the spokes after installation.

[0042] The number of the high points 131 and the low points 132 of the curved surface is 4*N (N is a positive integer), and the number of the spoke mounting holes 14 is 4*N (N is a positive integer). In the present embodiment, N=5, therefore, the number of the high points 131 and the low points 132 of the curved surface is 20, and the number of the spoke mounting holes 14 is 20.

[0043] A wheel assembly with a side wall having a curved surface with high and low points alternately distributed, comprising: a wheel rim with a side wall having a curved surface with high and low points alternately distributed, and A hub is arranged in a wheel rim body, and a spoke structure connecting the hub and the wheel rim body.

[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A wheel rim having a curved side wall with alternating high and low points, characterized in that: include: The rim body includes an inner ring and an outer ring arranged opposite to the inner ring, the inner ring is used to install the spoke structure, the outer ring is used to install the tire, and the side wall between the inner ring and the outer ring is arranged with a curved surface structure with an alternating ring array of curved surface high points and curved surface low points.

2. A wheel rim with a curved side wall and alternating high and low points according to claim 1, characterized in that: The cross section of the side wall of the rim body along its axial direction satisfies the function expression of the first curve.

3. A wheel rim with a curved side wall and alternating high and low points according to claim 2, characterized in that: The function expression of the first curve is y=ax²+bx+c (a≠0).

4. A wheel rim with a curved sidewall and alternating high and low points according to claim 1, characterized in that: The cross-sectional height of the side wall of the wheel rim body along its axial direction is defined as , then the height of the high point and the low point of the surface from the bottom of the inner circle =1 / 4~1 / 3 .

5. A wheel rim with a curved sidewall and alternating high and low points according to claim 1, characterized in that: After the wheel rim body is unfolded along its radial direction, the vertical cross section of the curved surface structure along its length direction satisfies the function expression of the second curve.

6. A wheel rim with a curved side wall and alternating high and low points according to claim 5, characterized in that: The function expression of the second curve is: , where A is the amplitude factor and L is the period of the second curve.

7. A wheel rim with a curved side wall and alternating high and low points according to claim 1, characterized in that: A plurality of spoke mounting holes are arranged in an annular array on the side wall of the inner ring, and each spoke mounting hole is located at a high point of the curved surface of the curved surface structure on the inner ring.

8. A wheel rim with a curved side wall and alternating high and low points according to claim 7, characterized in that: The number of the surface high points and the surface low points is 4*N (N is a positive integer).

9. A wheel rim with a curved side wall and alternating high and low points according to claim 8, characterized in that: The number of the spoke mounting holes is 4*N (N is a positive integer).

10. A wheel assembly having a side wall with alternating high and low points, characterized in that: include: A wheel rim having a curved side wall with alternating high and low points as claimed in any one of claims 1 to 9, and A hub is arranged in a wheel rim body, and a spoke structure connecting the hub and the wheel rim body.

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