A method for calculating shoulder sinking amount and sinking angle based on multiple crown arcs

Abstract

This invention proposes a method for calculating tire shoulder depression and depression angle based on multiple tire crown arcs, comprising: dividing the entire tire crown arc into a first crown arc, a second crown arc, and a third crown arc; drawing a tangent to the entire crown arc from the left endpoint of the first crown arc, defined as line segment XY; defining the distance between the two endpoints of the third crown arc as line segment three; drawing a perpendicular line from the midpoint of line segment three to the third crown arc extending to point J; defining the distance between point J and line segment XY as line segment H3; and connecting the right endpoint of the third crown arc with... Point J extends to the intersection of line segment XY at point P; shoulder sinking h = H3 / XX3*L3; where XX3 is the length of line segment PJ, and L3 is the distance from point P to the right endpoint of the third crown arc; sinking angle angle = atan(h / S)*180 / π; where angle is the sinking angle, atan is the arctangent value, and S is the distance from the left endpoint of the first crown arc to point M, where a perpendicular line is drawn from the right endpoint of the third crown arc to line segment XY intersects at point M. This invention is characterized by ease of operation, short processing time, and high accuracy.

Description

Technical Field

[0001] This invention belongs to the field of calculating tire shoulder subsidence and subsidence angle, and particularly relates to a method for calculating tire shoulder subsidence and subsidence angle based on multiple tire crown arcs. Background Technology

[0002] The tire crown refers to the entire area between the two tire shoulders, including the tread, buffer layer (or belt layer), and cord layer, which is the main component where the tire contacts the ground when driving.

[0003] The tire crown is composed of multiple arcs. To ensure a smooth transition and maintain tire performance, three arcs are typically used in the crown design. Initially, the shoulder deflection and angle need to be determined based on the tire's product positioning and performance. The crown arc is then drawn using these parameters. However, adjusting these two variables requires repeatedly drawing the drawings to adjust the crown arc radius and length, making this method overly cumbersome and time-consuming, and unable to quickly calculate the shoulder deflection and angle.

[0004] Therefore, developing a fast, convenient, and accurate method for calculating tire shoulder subsidence and subsidence angle is key to solving the above problems. Summary of the Invention

[0005] This invention addresses the technical problems of traditional methods being too cumbersome and time-consuming by proposing a method for calculating the tire shoulder subsidence and subsidence angle based on multiple tire crown arcs. This method is easy to operate, time-saving, and highly accurate.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A method for calculating tire shoulder subsidence and subsidence angle based on multiple tire crown arcs includes the following steps:

[0008] Divide the entire tire crown arc from left to right into the first crown arc, the second crown arc, and the third crown arc. Draw a tangent to the entire crown arc from the left endpoint of the first crown arc, and define it as line segment XY. Define the straight-line distance between the two endpoints of the first crown arc, the second crown arc, and the third crown arc as line segment one, line segment two, and line segment three, respectively.

[0009] Draw a perpendicular line from the right endpoint of line segment one to line segment XY, defined as line segment H1. Draw a perpendicular line from the midpoint of line segment two to the direction of the second tread arc, extending to point F. The straight-line distance between point F and line segment XY is defined as line segment H2. Draw a perpendicular line from the midpoint of line segment three to the third tread arc, extending to point J. The straight-line distance between point J and line segment XY is defined as line segment H3. Connect the right endpoint of the third tread arc and point J, extending to line segment XY, intersecting at point P.

[0010] The shoulder subsidence is calculated according to the following formula:

[0011] h = H3 / XX3*L3(1);

[0012] In the above formula (1): h is the amount of shoulder sinking, H3 is the length of line segment H3, XX3 is the length of line segment PJ, and L3 is the straight-line distance between point P and the right end point of the third crown arc.

[0013] The sinking angle is calculated according to the following formula:

[0014] angle=atan(h / S)*180 / π (2);

[0015] In the above formula (2): angle is the sinking angle, atan is the arctangent value, expressed in radians, h is the amount of shoulder sinking, S is the straight-line distance from the left end of the first crown arc to point M, where the right end of the third crown arc is perpendicular to the line segment XY and intersects at point M.

[0016] In one embodiment, the radians b1, b2, and b3 corresponding to the first, second, and third crown arcs are calculated using the following method:

[0017] The arc lengths of the first, second, and third crown arcs are defined as ARC1, ARC2, and ARC3, respectively, and the arc radii are defined as TR1, TR2, and TR3, respectively, and ARC1, ARC2, and ARC3 and TR1, TR2, and TR3 are known variables;

[0018] The curvature b1 of the first crown arc, the curvature b2 of the second crown arc, and the curvature b3 of the third crown arc are calculated according to the following formulas:

[0019] b1 = ARC1 / TR1 (3);

[0020] b2 = ARC2 / TR2 (4);

[0021] b3 = ARC3 / TR3 (5).

[0022] In one embodiment, the radian angle a1 between the two lines corresponding to line segment H1, the radian angle a2 between the two lines corresponding to line segment H2, and the radian angle a3 between the two lines corresponding to line segment H3 are calculated according to the following formulas:

[0023] a1 = b1 (6);

[0024] a2=a1+b2 (7);

[0025] a3 = a2 + b3 (8).

[0026] In one embodiment, a perpendicular line is drawn from the midpoint of the line segment towards the first tread arc, extending to point B. The straight-line distance between the left and right endpoints of the first tread arc and point B is defined as CX1, and CX1 is calculated using the following formula:

[0027] CX1=TR1*tan(b1 / 2) (9);

[0028] In the above formula (9): TR1 is the radius of the first crown arc, and b1 is the curvature of the first crown arc;

[0029] Define CX2 as the straight-line distance between the left and right endpoints of the second treadmill crown arc and point F, respectively, and calculate CX2 using the following formula:

[0030] CX2=TR2*tan(b2 / 2) (10);

[0031] In the above formula (10): TR2 is the radius of the second crown arc, and b2 is the curvature of the second crown arc;

[0032] Define CX3 as the straight-line distance between the left and right endpoints of the third cephalic arch and point J, respectively, and calculate CX3 using the following formula:

[0033] CX3=TR3*tan(b3 / 2) (11);

[0034] In the above formula (11): TR3 is the radius of the third crown arc and b3 is the curvature of the third crown arc.

[0035] In one embodiment, the line segment H1 is calculated using the following formula:

[0036] H1=CX1*sin(a1) (12);

[0037] The length of the line segment between point B and point F is defined as L1, and L1 is calculated using the following formula:

[0038] L1 = CX1 + CX2 (13);

[0039] The line segment H2 is calculated using the following formula:

[0040] H2 = H1 / CX1*L1 (14);

[0041] The line segment connecting the right endpoint of the second crown arc and point F is extended in the XY direction and intersects at point N. The straight-line distance between N and F is defined as line segment XX2, which is calculated by the following formula:

[0042] XX2=H2 / sin(a2) (15);

[0043] The straight-line distance between point N and point J is defined as L2, which is calculated using the following formula:

[0044] L2 = XX2 + CX2 + CX3 (16);

[0045] The line segment H3 is calculated using the following formula:

[0046] H3 = H2 / XX2*L2 (17);

[0047] The XX3 is calculated using the following formula:

[0048] XX3=H3 / sin(a3) (18);

[0049] The straight-line distance between point P and the right endpoint of the third crown arc is defined as L3, which is calculated using the following formula:

[0050] L3=XX3+CX3 (19).

[0051] In one embodiment, the straight-line distance between the left endpoint of the first treadmill crown arc and point B is defined as S0, and S0 is calculated using the following formula:

[0052] S0 = CX1 (20).

[0053] In one embodiment, a perpendicular line is drawn from point F to the line segment in the XY direction, intersecting at point G. The straight-line distance between point B and point G is defined as S1, which is calculated using the following formula:

[0054] S1=L1*cos(a1) (21).

[0055] In one embodiment, a perpendicular line is drawn from point J to the line segment in the XY direction, intersecting at point K. The distance between point G and point K is defined as S2, which is calculated using the following formula:

[0056] S2=(L2-XX2)*cos(a2) (22).

[0057] In one embodiment, the distance between point K and point M is defined as S3, which is calculated using the following formula:

[0058] S3=CX3*cos(a3) (23).

[0059] In one embodiment, S is calculated using the following formula:

[0060] S = S0 + S1 + S2 + S3 (24).

[0061] Compared with the prior art, the advantages and positive effects of the present invention are as follows:

[0062] 1. This invention provides a method for calculating the shoulder subsidence and subsidence angle based on multiple crown arcs. By dividing the entire crown arc into multiple crown arc segments and combining relevant mathematical calculation methods, the shoulder subsidence and subsidence angle can be determined. This solves the problem in traditional methods where the shoulder subsidence and subsidence angle need to be adjusted without drawing drawings in advance. It also avoids the technical problem of having to repeatedly draw drawings to adjust the radius and length of the crown arc to determine whether the above two variables are appropriate.

[0063] 2. The present invention provides a method for calculating the shoulder subsidence and subsidence angle based on multiple crown arcs, which is easy to operate, time-saving and accurate. Attached Figure Description

[0064] Figure 1 This is a schematic diagram of the tire crown result provided in an embodiment of the present invention;

[0065] Figure 2 This is a flowchart for calculating the tire shoulder subsidence and subsidence angle provided in an embodiment of the present invention;

[0066] Figure 3 This is a schematic diagram of the tire structure of SUV tire specification 225 / 60R18 provided in an embodiment of the present invention. Detailed Implementation

[0067] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0068] This invention provides a method for calculating tire shoulder subsidence and subsidence angle based on multiple tire crown arcs, comprising the following steps:

[0069] See attached document Figure 1 Divide the entire tire crown arc from left to right into a first crown arc, a second crown arc, and a third crown arc. Draw a tangent line to the entire crown arc starting from the left endpoint of the first crown arc, and define it as line segment XY. Define the straight-line distance between the two endpoints of the first crown arc, the second crown arc, and the third crown arc as line segment one, line segment two, and line segment three, respectively.

[0070] Draw a perpendicular line from the right endpoint of line segment one to line segment XY, defined as line segment H1. Draw a perpendicular line from the midpoint of line segment two to the direction of the second tread arc, extending to point F. The straight-line distance between point F and line segment XY is defined as line segment H2. Draw a perpendicular line from the midpoint of line segment three to the third tread arc, extending to point J. The straight-line distance between point J and line segment XY is defined as line segment H3. Connect the right endpoint of the third tread arc and point J, extending to line segment XY, intersecting at point P.

[0071] The shoulder subsidence is calculated according to the following formula:

[0072] h = H3 / XX3*L3 (1);

[0073] In the above formula (1): h is the amount of shoulder sinking, H3 is the length of line segment H3, XX3 is the length of line segment PJ, and L3 is the straight-line distance between point P and the right end point of the third crown arc.

[0074] The sinking angle is calculated according to the following formula:

[0075] angle=atan(h / S)*180 / π (2);

[0076] In the above formula (2): angle is the sinking angle, atan is the arctangent value, expressed in radians, h is the amount of shoulder sinking, S is the straight-line distance from the left end of the first crown arc to point M, where the right end of the third crown arc is perpendicular to the line segment XY and intersects at point M.

[0077] The above embodiments provide a method for calculating tire shoulder deflection and deflection angle based on multiple tire crown arcs. This method first divides the entire tire crown arc into multiple segments, then draws a tangent to the entire crown arc based on the left endpoint of the first segment, and finally calculates the tire shoulder deflection h and deflection angle angle through a series of calculation methods. This method can quickly and accurately calculate the tire shoulder deflection and deflection angle using only the above mathematical methods. Unlike traditional methods, it eliminates the need to draw drawings in advance or repeatedly draw drawings to adjust the radius and length of the crown arc to determine whether the two variables are appropriate when adjusting the tire shoulder deflection and deflection angle. The calculation method provided by this invention is simple to operate, fast, and accurate.

[0078] It should also be noted that in some other embodiments of the present invention, the entire crown arc can be divided into different segments from left to right. For example, in the design of semi-steel radial passenger car tires, those with a nominal section width of less than 185 are divided into two crown arc segments, namely the first crown arc and the second crown arc; very few tire sizes are divided into four crown arc segments, namely the first crown arc, the second crown arc, the third crown arc, and the fourth crown arc, etc.

[0079] In one specific embodiment, the radians b1, b2, and b3 corresponding to the first, second, and third crown arcs are calculated using the following method:

[0080] The arc lengths of the first, second, and third crown arcs are defined as ARC1, ARC2, and ARC3, respectively, and the arc radii are defined as TR1, TR2, and TR3, respectively, and ARC1, ARC2, and ARC3 and TR1, TR2, and TR3 are known variables;

[0081] The curvature b1 of the first crown arc, the curvature b2 of the second crown arc, and the curvature b3 of the third crown arc are calculated according to the following formulas:

[0082] b1 = ARC1 / TR1(3);

[0083] b2 = ARC2 / TR2(4);

[0084] b3 = ARC3 / TR3(5).

[0085] In one specific embodiment, the radian angle a1 between the two lines corresponding to line segment H1, the radian angle a2 between the two lines corresponding to line segment H2, and the radian angle a3 between the two lines corresponding to line segment H3 are calculated according to the following formulas:

[0086] a1 = b1(6);

[0087] a2=a1+b2(7);

[0088] a3 = a2 + b3 (8).

[0089] In one specific embodiment, a perpendicular line is drawn from the midpoint of the line segment towards the first tread arc, extending to point B. The straight-line distance between the left and right endpoints of the first tread arc and point B is defined as CX1, and CX1 is calculated using the following formula:

[0090] CX1=TR1*tan(b1 / 2) (9);

[0091] In the above formula (9): TR1 is the radius of the first crown arc, and b1 is the curvature of the first crown arc;

[0092] Define CX2 as the straight-line distance between the left and right endpoints of the second treadmill crown arc and point F, respectively, and calculate CX2 using the following formula:

[0093] CX2=TR2*tan(b2 / 2) (10);

[0094] In the above formula (10): TR2 is the radius of the second crown arc, and b2 is the curvature of the second crown arc;

[0095] Define CX3 as the straight-line distance between the left and right endpoints of the third cephalic arch and point J, respectively, and calculate CX3 using the following formula:

[0096] CX3=TR3*tan(b3 / 2) (11);

[0097] In the above formula (11): TR3 is the radius of the third crown arc and b3 is the curvature of the third crown arc.

[0098] In one specific embodiment, the line segment H1 is calculated using the following formula:

[0099] H1=CX1*sin(a1) (12);

[0100] The length of the line segment between point B and point F is defined as L1, and L1 is calculated using the following formula:

[0101] L1 = CX1 + CX2 (13);

[0102] The line segment H2 is calculated using the following formula:

[0103] H2 = H1 / CX1*L1 (14);

[0104] The line segment connecting the right endpoint of the second crown arc and point F is extended in the XY direction and intersects at point N. The straight-line distance between N and F is defined as line segment XX2, which is calculated by the following formula:

[0105] XX2=H2 / sin(a2) (15);

[0106] The straight-line distance between point N and point J is defined as L2, which is calculated using the following formula:

[0107] L2 = XX2 + CX2 + CX3 (16);

[0108] The line segment H3 is calculated using the following formula:

[0109] H3 = H2 / XX2*L2 (17);

[0110] The XX3 is calculated using the following formula:

[0111] XX3=H3 / sin(a3) (18);

[0112] The straight-line distance between point P and the right endpoint of the third crown arc is defined as L3, which is calculated using the following formula:

[0113] L3=XX3+CX3 (19).

[0114] In one specific embodiment, the straight-line distance between the left endpoint of the first treadmill crown arc and point B is defined as S0, and S0 is calculated using the following formula:

[0115] S0 = CX1 (20).

[0116] In one specific embodiment, a perpendicular line is drawn from point F to the line segment in the XY direction, intersecting at point G. The straight-line distance between point B and point G is defined as S1, which is calculated using the following formula:

[0117] S1=L1*cos(a1) (21).

[0118] In one specific embodiment, a perpendicular line is drawn from point J to the line segment in the XY direction, intersecting at point K. The distance between point G and point K is defined as S2, which is calculated using the following formula:

[0119] S2=(L2-XX2)*cos(a2) (22).

[0120] In one specific embodiment, the distance between point K and point M is defined as S3, which is calculated using the following formula:

[0121] S3=CX3*cos(a3) (23).

[0122] In one specific embodiment, S is calculated using the following formula:

[0123] S = S0 + S1 + S2 + S3 (24).

[0124] To more clearly and in detail introduce the method for calculating the shoulder subsidence and subsidence angle based on multiple crown arcs provided by the embodiments of the present invention, the following description will be made in conjunction with specific embodiments.

[0125] Example 1

[0126] This embodiment provides a method for calculating tire shoulder subsidence and subsidence angle based on multiple tire crown arcs, referring to... Figure 1 The attached diagram shows the process, specifically:

[0127] h Definition: The endpoint of the entire crown arc is the shoulder area, and the vertical distance from this position to the crown plane is called the shoulder subsidence.

[0128] Angle definition: The angle between the line connecting the shoulder and the center of the crown and the plane of the crown is called the shoulder drop angle.

[0129] The entire tire crown arc is divided into three segments: arcs XC, CH, and HL. This embodiment calculates the shoulder sag (h) and sag angle based on the radius and length of these three segments, combined with the attached... Figure 1 The definitions of each label are explained below:

[0130] (1) The foot of the perpendicular between line OX and line XY;

[0131] (2) The crown arc is composed of arcs XC, CH and HL, with L being the end point of the shoulder area;

[0132] (3) The center of arc XC is point O, the center of arc CH is point O1, arc CH is tangent to arc XC, the center of arc HL is point O2, and arc HL is tangent to arc CH.

[0133] (4) Point A is the midpoint of line XC. A perpendicular line is drawn from point A to arc XC and extended to point B. Point B lies on line XY.

[0134] (5) Point E is the midpoint of line CH. A perpendicular line is drawn from point E to arc CH and extended to point F. Points B, C, and F are on a straight line.

[0135] (6) Point I is the midpoint of line HL. A perpendicular line is drawn from point I to arc HL and extended to point J. Points F, H, J, and N are on a straight line, and point N is on line XY.

[0136] (7) Connect lines L and J, extend them to lines X and Y, and intersect at point P;

[0137] (8) TR1, TR2, TR3: The corresponding arc radii of arcs XC, CH and HL respectively;

[0138] (9)ARC1,ARC2,ARC3: The corresponding arc lengths of arcs XC, CH and HL;

[0139] (10)CX1: The length of line XB and line BC;

[0140] (11)CX2: The lengths of lines CF and FH;

[0141] (12)CX3: The length of line HJ and line JL;

[0142] (13) Points D, G, K are the points where points C, F, J are perpendicular to the line XY;

[0143] (14)H1: The length of line CD;

[0144] (15)H2: The length of line FG;

[0145] (16)H3: The length of line JK;

[0146] (17) L1: The length of line BF;

[0147] (18) L2: The length of line NJ;

[0148] (19) L3: Length of line PL;

[0149] (20)XX2: The length of line NF;

[0150] (21)XX3: The length of line PJ;

[0151] (22) b1, b2, b3: the radians of arcs XC, CH and HL respectively;

[0152] (23)a1: The radian of the angle between line BC and BD corresponding to line H1;

[0153] (24)a2: the radian of the angle between line NF and NG corresponding to line H2;

[0154] (25)a3: the radian of the angle between line PJ and PK corresponding to line H3;

[0155] (26)S0: The length of line XB;

[0156] (27)S1: The length of line BG;

[0157] (28)S2: The length of line GK;

[0158] (29)S3: The length of the straight line KM.

[0159] Calculation process:

[0160] The arc lengths ARC1, ARC2, and ARC3 corresponding to arcs XC, CH, and HL, as well as their corresponding TR1, TR2, and TR3, are known variables. The tire shoulder subsidence h is calculated using the following method:

[0161] b1 = ARC1 / TR1;

[0162] b2 = ARC2 / TR2;

[0163] b3 = ARC3 / TR3;

[0164] a1 = b1;

[0165] a2 = a1 + b2;

[0166] a3 = a2 + b3;

[0167] CX1 = TR1 * tan(b1 / 2);

[0168] CX2 = TR2 * tan(b2 / 2);

[0169] CX3 = TR3 * tan(b3 / 2);

[0170] H1 = CX1 * sin(a1);

[0171] L1 = CX1 + CX2;

[0172] H2 = H1 / CX1*L1;

[0173] XX² = H² / sin(a²);

[0174] L2 = XX2 + CX2 + CX3;

[0175] H3 = H2 / XX2*L2;

[0176] XX3=H3 / sin(a3);

[0177] L3 = XX3 + CX3;

[0178] h = H3 / XX3*L3.

[0179] The sink angle (angle) is calculated using the following method:

[0180] S0 = CX1;

[0181] S1 = L1 * cos(a1);

[0182] S2 = (L2 - X2) * cos(a2);

[0183] S3 = CX3 * cos(a3);

[0184] S = S0 + S1 + S2 + S3;

[0185] angle = atan(h / S) * 180 / π.

[0186] Example 2

[0187] This embodiment provides a method for calculating the shoulder subsidence and subsidence angle based on multiple crown arcs, specifically:

[0188] Figure 3These are the design parameters for the tread of tire model 205 / 55R16. The tire tread is divided into three tread arcs, with the corresponding arc radii being TR1, TR2, and TR3, respectively; the corresponding arc lengths are ARC1, ARC2, and ARC3, respectively. The above parameter data are summarized below:

[0189] Table 1. Tire crown design parameters for 205 / 55R16

[0190] Design parameters Specific data (mm) ARC1 33 TR1 850 ARC2 32.3 TR2 320 ARC3 23.7 TR3 200

[0191] The calculation was performed according to the calculation method described in Example 1, and the calculation results are as follows:

[0192] Table 2 Calculation Results

[0193]

[0194]

[0195] The calculation method provided in this embodiment shows that the shoulder subsidence h = 8.20 and the subsidence angle angle = 5.3°, which is consistent with the results drawn using drafting software. Therefore, the calculation method provided by this invention can directly calculate the shoulder subsidence h and the subsidence angle angle without the need for prior or multiple drawing operations. Furthermore, when it is necessary to adjust the shoulder subsidence h or the subsidence angle angle, it is only necessary to adjust one or more of the following variables in the above calculation method: the radius of the different crown arcs (ARC1, ARC2, and ARC3) and the radius of the arcs (TR1, TR2, and TR3). When these two values ​​meet the target values, drawing can begin without repeatedly drawing drawings to adjust the radius and length of the crown arc to confirm whether the above two values ​​meet the requirements.

Claims

1. A method for calculating tire shoulder subsidence and subsidence angle based on multiple tire crown arcs, characterized in that, Includes the following steps: Divide the entire tire crown arc from left to right into the first crown arc, the second crown arc, and the third crown arc. Draw a tangent line to the entire crown arc starting from the left end of the first crown arc, and define it as line segment XY. The straight-line distances between the two endpoints of the first, second, and third crown arcs are defined as line segment one, line segment two, and line segment three, respectively. Draw a perpendicular line from the right endpoint of line segment one to line segment XY, defined as line segment H1. Draw a perpendicular line from the midpoint of line segment two to the direction of the second tread arc, extending to point F. The straight-line distance between point F and line segment XY is defined as line segment H2. Draw a perpendicular line from the midpoint of line segment three to the third tread arc, extending to point J. The straight-line distance between point J and line segment XY is defined as line segment H3. Connect the right endpoint of the third tread arc and point J, extending to line segment XY, intersecting at point P. The shoulder subsidence is calculated according to the following formula: h = H3 / XX3*L3(1); In the above formula (1): h is the amount of shoulder sinking, H3 is the length of line segment H3, XX3 is the length of line segment PJ, and L3 is the straight-line distance between point P and the right end point of the third crown arc. The sinking angle is calculated according to the following formula: angle=atan(h / S)*180 / π(2); In the above formula (2): angle is the sinking angle, atan is the arctangent value, expressed in radians, h is the amount of shoulder sinking, S is the straight-line distance from the left end of the first crown arc to point M, where the right end of the third crown arc is perpendicular to the line segment XY and intersects at point M.

2. The method for calculating the shoulder subsidence and subsidence angle based on multiple crown arcs according to claim 1, characterized in that, The radii b1, b2, and b3 corresponding to the first, second, and third crown arcs are calculated using the following method: The arc lengths of the first, second, and third crown arcs are defined as ARC1, ARC2, and ARC3, respectively, and the arc radii are defined as TR1, TR2, and TR3, respectively, and ARC1, ARC2, and ARC3 and TR1, TR2, and TR3 are known variables; The curvature b1 of the first crown arc, the curvature b2 of the second crown arc, and the curvature b3 of the third crown arc are calculated according to the following formulas: b1 = ARC1 / TR1(3); b2 = ARC2 / TR2(4); b3 = ARC3 / TR3(5).

3. The method for calculating the shoulder subsidence and subsidence angle based on multiple crown arcs according to claim 2, characterized in that, The radian angle a1 between the two lines corresponding to line segment H1, the radian angle a2 between the two lines corresponding to line segment H2, and the radian angle a3 between the two lines corresponding to line segment H3 are calculated according to the following formulas: a1 = b1(6); a2=a1+b2(7); a3 = a2 + b3 (8).

4. The method for calculating the shoulder subsidence and subsidence angle based on multiple crown arcs according to claim 3, characterized in that, Draw a perpendicular line from the midpoint of the line segment towards the first crown arc, extending to point B. Define the straight-line distance between the left and right endpoints of the first crown arc and point B as CX1. CX1 is calculated using the following formula: CX1=TR1*tan(b1 / 2)(9); In the above formula (9): TR1 is the radius of the first crown arc, and b1 is the curvature of the first crown arc; Define CX2 as the straight-line distance between the left and right endpoints of the second treadmill crown arc and point F, respectively, and calculate CX2 using the following formula: CX2=TR2*tan(b2 / 2)(10); In the above formula (10): TR2 is the radius of the second crown arc, and b2 is the curvature of the second crown arc; Define CX3 as the straight-line distance between the left and right endpoints of the third cephalic arch and point J, respectively, and calculate CX3 using the following formula: CX3=TR3*tan(b3 / 2)(11); In the above formula (11): TR3 is the radius of the third crown arc and b3 is the curvature of the third crown arc.

5. The method for calculating the shoulder subsidence and subsidence angle based on multiple crown arcs according to claim 4, characterized in that, The line segment H1 is calculated using the following formula: H1 = CX1 * sin(a1)(12); The length of the line segment between point B and point F is defined as L1, and L1 is calculated using the following formula: L1 = CX1 + CX2 (13); The line segment H2 is calculated using the following formula: H2=H1 / CX1*L1(14); The line segment connecting the right endpoint of the second crown arc and point F is extended in the XY direction and intersects at point N. The straight-line distance between N and F is defined as line segment XX2, which is calculated by the following formula: XX2=H2 / sin(a2)(15); The straight-line distance between point N and point J is defined as L2, which is calculated using the following formula: L2=XX2+CX2+CX3(16); The line segment H3 is calculated using the following formula: H3 = H2 / XX2*L2(17); The XX3 is calculated using the following formula: XX3=H3 / sin(a3)(18); The straight-line distance between point P and the right endpoint of the third crown arc is defined as L3, which is calculated using the following formula: L3=XX3+CX3(19).

6. The method for calculating the shoulder subsidence and subsidence angle based on multiple crown arcs according to claim 5, characterized in that, Define S0 as the straight-line distance between the left endpoint of the first treadmill crown arc and point B, and S0 is calculated using the following formula: S0 = CX1(20).

7. The method for calculating the shoulder subsidence and subsidence angle based on multiple crown arcs according to claim 6, characterized in that, A perpendicular line is drawn from point F to the line segment in the XY direction, intersecting at point G. The straight-line distance between point B and point G is defined as S1, which is calculated using the following formula: S1=L1*cos(a1)(21).

8. The method for calculating the shoulder subsidence and subsidence angle based on multiple crown arcs according to claim 7, characterized in that, A perpendicular line is drawn from point J to the line segment in the XY direction, intersecting at point K. The distance between point G and point K is defined as S2, which is calculated using the following formula: S2=(L2-XX2)*cos(a2)(22).

9. The method for calculating the shoulder subsidence and subsidence angle based on multiple crown arcs as described in claim 8, characterized in that, The distance between point K and point M is defined as S3, which is calculated using the following formula: S3=CX3*cos(a3)(23).

10. The method for calculating the shoulder subsidence and subsidence angle based on multiple crown arcs according to claim 9, characterized in that, S is calculated using the following formula: S = S0 + S1 + S2 + S3 (24).

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