A method of measuring the camber of a tbr tread

Abstract

The present application relates to a kind of TBR tread camber measurement method, belong to tire manufacturing technical field, camber ruler is placed along the width direction of tire tread, the contact condition of camber ruler and crown, shoulder on both sides of crown is determined;If the camber ruler and the crown, the shoulder are all contacted, it indicates that tire tread camber adopts a section of arc structure, the radius of camber ruler is used as the center arc radius of the crown;If the camber ruler and the crown or the shoulder are not contacted, it indicates that tire tread camber is not adopted a section of arc structure, the center arc radius of the crown and the connecting arc radius of the shoulder are measured respectively, the present application is measured to tread camber radius by camber ruler, corresponding measurement method is formulated to different deformation forms to form unified measurement standard, for the same measurement sample, even different operators can also obtain the same value, improve measurement accuracy.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of tire manufacturing, and particularly relates to a TBR tread arc measurement method. BACKGROUND

[0002] During driving, the TBR tire crown directly contacts the ground, the contact patch and the contact pressure of the tire crown form the frictional force with the ground, so as to generate the grip force, and thus the tire grip force mainly comes from the tire crown. The tire contact patch is mainly controlled by the crown curve arc and the sinking amount, under the condition that the crown pattern, tire structure and tire rubber formula are consistent, the tire contact patch is adjusted by adjusting the crown curve arc, the uniformity of the contact pressure is improved, the tire is more uniform in the use process, and the driving process is more stable.

[0003] At present, there is no specific measurement method for the tread arc radius, resulting in large differences in the measured values. Meanwhile, the growth rates of the tire crown surfaces are different, and various tread arc deformation forms are formed. For the deformation forms, different processing methods of each operator are different, and the tread arc values obtained are different and have large value differences. SUMMARY

[0004] In view of various deficiencies of the prior art, in order to solve the above problems, a TBR tread arc measurement method is provided.

[0005] To achieve the above purpose, the present application provides the following technical scheme:

[0006] A TBR tread arc measurement method, comprising:

[0007] Placing the arc ruler along the width direction of the tire tread to determine the contact condition of the arc ruler with the tire crown and the tire shoulder on both sides of the tire crown;

[0008] If the arc ruler contacts the tire crown and the tire shoulder, it indicates that the tire tread arc adopts a segment arc structure, and the radius of the arc ruler is taken as the center arc radius of the tire crown.

[0009] If the arc ruler does not contact the tire crown or the tire shoulder, it indicates that the tire tread arc does not adopt a segment arc structure, and the center arc radius of the tire crown and the connecting arc radius of the tire shoulder are measured respectively.

[0010] The present application is further provided that the longitudinal section of the arc ruler is in a circular arc shape, which includes an inner circular arc and an outer circular arc, and the center arc radius and the connecting arc radius are determined according to the radius of the inner circular arc.

[0011] The present application is further provided that the arc ruler is placed along the width direction of the tire tread, specifically:

[0012] The arc ruler is replaced in order of increasing radius of the inner arc until the width of the arc ruler is greater than the width of the tire running surface, and the width of the tire running surface is the sum of the width of the crown and the width of the shoulder.

[0013] The application is further provided to view the contact between the arc ruler and the crown and the shoulders on both sides of the crown, specifically:

[0014] The inner arc of the arc ruler is placed along the width direction of the tire tread, and it is viewed whether there is a gap between the inner arc and the crown and the shoulder, if there is no gap or the gap value is not greater than the set threshold value, it is considered to be in contact, if the gap value is greater than the set threshold value, it is considered not to be in contact.

[0015] The application is further provided that the set threshold value includes a crown set threshold value and a shoulder set threshold value, there is a gap between the inner arc and the crown, and the gap value is not greater than the crown set threshold value, it is considered to be in contact, there is a gap between the inner arc and the shoulder, and the sum of the gap values between the inner arc and the shoulders on both sides is not greater than the shoulder set threshold value, it is considered to be in contact.

[0016] The application is further provided that the crown is located at a point on the center line of the tire running surface as a center point of the crown, and a point at the junction of the crown and the shoulder is a shoulder point, the arc ruler is in contact with the crown and the shoulder, including:

[0017] There is no gap between the arc ruler and the center point of the crown and the shoulder point;

[0018] There is no gap between the arc ruler and the center point of the crown and the shoulder point on one side, and the arc ruler is not in contact with the shoulder point on the other side due to the pattern groove;

[0019] There is no gap between the arc ruler and the center point of the crown and the shoulder point, and there is a gap between the arc ruler and the part of the crown other than the center point, and the gap value is not greater than the crown set threshold value;

[0020] There is a gap between the arc ruler and the center point of the crown, and the gap value is not greater than the crown set threshold value, there is a gap between the arc ruler and the shoulder, and the sum of the gap values between the inner arc and the shoulders on both sides is not greater than the shoulder set threshold value;

[0021] There is no gap between the arc ruler and the center point of the crown, there is a gap between the arc ruler and the shoulder, and the sum of the gap values between the inner arc and the shoulders on both sides is not greater than the shoulder set threshold value.

[0022] The application further provides that the arc ruler contacts the tire crown and the tire shoulder, and further comprises: a gap between the arc ruler and the center of the tire crown, the center of the tire crown being a region containing the center point of the tire crown, and the gap value being not greater than a tire crown setting threshold, and no gap between the arc ruler and the tire shoulder point.

[0023] The application further provides that if the arc ruler does not contact the tire crown or the tire shoulder, specifically:

[0024] no gap between the arc ruler and the center point of the tire crown, a gap between the arc ruler and the tire shoulder, and the sum of the gap values of the inner arc and the two tire shoulders being greater than a tire shoulder setting threshold;

[0025] no gap between the arc ruler and the center point of the tire crown, and a gap between the arc ruler and the tire crown except the center point, and the gap value being not greater than a tire crown setting threshold, a gap between the arc ruler and the tire shoulder, and the sum of the gap values of the inner arc and the two tire shoulders being greater than a tire shoulder setting threshold;

[0026] a gap between the arc ruler and the center point of the tire crown, and the gap value being not greater than a tire crown setting threshold, a gap between the arc ruler and the tire shoulder, and the sum of the gap values of the inner arc and the two tire shoulders being greater than a tire shoulder setting threshold;

[0027] a gap between the arc ruler and the center point of the tire crown, and the gap value being greater than a tire crown setting threshold, a gap between the arc ruler and the tire shoulder, and the sum of the gap values of the inner arc and the two tire shoulders being not greater than a tire shoulder setting threshold.

[0028] The application further provides that the center arc radius of the tire crown and the connecting arc radius of the tire shoulder are measured respectively, specifically:

[0029] the arc rulers are replaced in sequence until the arc ruler contacts the tire crown and a first contact range exists, the first contact range being centered on the center point of the tire crown and covering 3 / 4 of the width of the tire crown, and the inner arc radius of the arc ruler being the center arc radius of the tire crown;

[0030] the arc rulers are replaced in sequence until the arc ruler contacts the tire shoulder and a second contact range exists, the second contact range being started from the tire shoulder point and covering 1 / 4 of the width of the tire shoulder, and the inner arc radius of the arc ruler being the connecting arc radius of the tire shoulder.

[0031] The application further provides that the tire crown setting threshold is 1 mm, and the tire shoulder setting threshold is 2 mm.

[0032] The application further provides that the tire shoulder and the tire side of the tire are a transition tire shoulder, and the measurement method of the transition arc radius of the transition tire shoulder is:

[0033] The point located at the joint of the shoulder and the transition shoulder is a transition shoulder point, and the arc ruler is replaced in turn until the arc ruler contacts the transition shoulder and a third contact range exists, the third contact range starts from the transition shoulder point and covers 1 / 4 of the transition shoulder width, and the inner arc radius of the arc ruler is taken as the transition arc radius of the transition shoulder.

[0034] The present application has the following advantages:

[0035] 1. The arc ruler is used to measure the arc radius of the tire, and a corresponding measurement method is formulated for different deformation forms to form a unified measurement standard, and even different operators can obtain the same value for the same measurement sample, thereby improving the measurement accuracy.

[0036] 2. According to the contact between the arc ruler and the crown and the shoulder, a plurality of deformation forms are listed, the number of deformation form samples is increased, and the coupling with the real application scene is improved, thereby laying a foundation for comparing the arc radius of the finished tire and the arc radius of the mold tire to obtain the variation law of the arc radius of the tire with different series flatness.

[0037] 3. According to the contact between the arc ruler and the crown and the shoulder, a plurality of deformation forms are listed, the number of deformation form samples is increased, and the coupling with the real application scene is improved, thereby laying a foundation for comparing the arc radius of the finished tire and the arc radius of the mold tire to obtain the variation law of the arc radius of the tire with different series flatness.

[0038] 4. The arc ruler is simple to use and has high reusability.

[0039] 5. It is suitable for measuring the arc radius of any type of TBR tire and has high universality. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 is a schematic view of a tire contact patch;

[0041] Figure 2 is a relationship diagram of the arc radius of the tire and the contact patch;

[0042] Figure 3 is a trend diagram of the outer diameter change rate of the center point of the crown and the shoulder point;

[0043] Figure 4 is a schematic view of the position of the center point of the crown and the shoulder point;

[0044] Figure 5 is a flowchart of the TBR tire arc measurement method in the present application;

[0045] Figure 6 is a structural schematic view of the arc ruler;

[0046] Figure 7 is a schematic view of placing the arc ruler along the width direction of the tire tread;

[0047] Figure 8 is a schematic diagram of the contact between the arc ruler and the crown and shoulder of the tire;

[0048] Figure 9 is a schematic diagram of the contact between the arc ruler and the crown and shoulder of the tire;

[0049] Figure 10 is a schematic diagram of the contact between the arc ruler and the crown and shoulder of the tire;

[0050] Figure 11 is a schematic diagram of the contact between the arc ruler and the crown and shoulder of the tire;

[0051] Figure 12 is a schematic diagram of the contact between the arc ruler and the crown and shoulder of the tire;

[0052] Figure 13 is a schematic diagram of the contact between the arc ruler and the crown and shoulder of the tire;

[0053] Figure 14 is a schematic diagram of the contact between the arc ruler and the crown and shoulder of the tire;

[0054] Figure 15 is a schematic diagram of the contact between the arc ruler and the crown and shoulder of the tire;

[0055] Figure 16 is a schematic diagram of the contact between the arc ruler and the crown and shoulder of the tire;

[0056] Figure 17 is a schematic diagram of the contact between the arc ruler and the crown and shoulder of the tire;

[0057] Figure 18 is a schematic diagram of the arc form of the tire tread. DETAILED DESCRIPTION

[0058] In order for those skilled in the art to better understand the technical solutions of the present application, the technical solutions of the present application will be described clearly and completely below in combination with the drawings of the present application. Based on the embodiments in the present application, other similar embodiments obtained by those skilled in the art without making creative efforts should all belong to the scope of protection of the present application. In addition, the directional words mentioned in the following embodiments, such as “up”, “down”, “left”, “right”, etc. are only the directions of the drawings, therefore, the directional words used are used for illustration and not for limiting the present application.

[0059] Example 1:

[0060] As Figure 1As shown, tire contact patches can be roughly divided into five types, from left to right: elliptical, square, hourglass, W-shaped, and M-shaped. Among these, elliptical contact patches help improve handling stability and hydroplaning, while square contact patches represent a primary development goal for reducing rolling resistance and improving wear resistance. Currently, most contact patches fall between elliptical and square. Hourglass patterns are clearly undesirable, W-shaped patterns experience high stress on the shoulder, leading to shoulder wear, and M-shaped patterns are prone to bottom cracking.

[0061] The tread curvature is generally determined by the tread radius after the carcass structure is fixed. Ground pressure distribution typically decreases from the center point of the tread towards the shoulder. A smaller tread radius results in increased ground pressure at the crown and decreased pressure at the shoulder, leading to poorer uniformity of ground pressure distribution and increased tread wear. Therefore, the tread radius of heavy-duty tires is generally not too small to ensure a certain degree of flatness. Multi-segment treads can also be used for adjustment and balance. Figure 18 As shown, tire tread curvature generally takes the following forms: one-segment arc (center arc R1 of the tire crown), two-segment arc (center arc R1 of the tire crown + connecting arc R2 of the tire shoulder), three-segment arc (center arc R1 of the tire crown + connecting arc R2 of the tire shoulder + transition arc radius R3 of the transition shoulder), and one-segment arc + tangent (center arc R1 of the tire crown + tangent of the center arc).

[0062] The inventor measured and analyzed the tread curvature and ground contact mark of tires with an aspect ratio of over 90% in imperial units, and obtained the following results: Figure 2 The relationship diagram shown is as follows, in which, Figure 2 The horizontal axis represents the tread radius, in mm. Figure 2 It can be directly concluded that when the tread radius is between 600-750mm, the tire contact patch is ideal, falling between an elliptical and a square mark. Therefore, the tread radius directly affects the shape of the tire contact patch.

[0063] Meanwhile, when measuring the outer dimensions of the tire, the inventor measured the outer perimeter of the center point of the tire crown and the shoulder point, and calculated the rate of change of the tire's outer diameter before and after inflation to obtain the following results: Figure 3 The diagram shown illustrates the relationship between tire profile and shoulder. The horizontal axis represents the aspect ratio (nominal section height / nominal section width), and the vertical axis represents the rate of change of the outer diameter. The positional relationship between the center point of the tire crown and the shoulder point is shown in the diagram. Figure 4 As shown. By Figure 3It can be directly concluded that when the flatness rate changes from 60% to 90%, the change trend of the outer diameter change rate of the shoulder point and the center point of the crown is different, the smaller the flatness rate is, the smaller the outer diameter change rate of the shoulder point is, and the larger the outer diameter change rate of the center point of the crown is, that is, the flatter the tire section is, the larger the deformation of the shoulder after inflation is, resulting in the larger stress on the shoulder, that is, the smaller the flatness rate is, the easier the hourglass mark is generated, and therefore, the tread arc radius needs to be designed according to different flatness rates.

[0064] Generally, the relationship between the tread arc radius and the tire performance is shown in Table 1:

[0065] Table 1:

[0066]

[0067] It can be directly concluded from Table 1 that the tread arc radius directly affects the tire performance, and when the tread arc radius is actually measured, due to the different growth rates of the points on the surface of the crown, various tread arc deformation problems occur, and the tread arc deformation directly affects the actual use performance of the tire.

[0068] As shown in Figure 5 , a TBR tread arc measurement method comprises:

[0069] S100, placing an arc ruler along the width direction of the tire tread to determine the contact condition of the arc ruler with the crown and the shoulders on both sides of the crown;

[0070] S200, if the arc ruler is in contact with the crown and the shoulders, it indicates that the tire tread arc adopts a segment arc structure, and the radius of the arc ruler is taken as the center arc radius of the crown;

[0071] S300, if the arc ruler is not in contact with the crown or the shoulders, it indicates that the tire tread arc does not adopt a segment arc structure, and the center arc radius of the crown and the connecting arc radius of the shoulder are measured respectively.

[0072] Preferably, as shown in Figure 6 , the longitudinal section of the arc ruler is in the shape of a circular arc, which comprises an inner circular arc and an outer circular arc, the radius of the inner circular arc is set as r, and the radius of the outer circular arc is set as R, and the center arc radius and the connecting arc radius are determined according to the radius of the inner circular arc.

[0073] The arc ruler is made of acrylic resin, a series of arc rulers are prepared in advance, and the radii of the inner circular arcs of the series of arc rulers are sequentially increased. At the same time, in order to avoid too many arc rulers affecting the measurement efficiency and increasing the production cost, preferably, one arc ruler is newly added for every 20mm increase in the radius of the inner circular arc.

[0074] Preferably, as shown inFigure 7 As shown, the arc gauges are changed sequentially in order of increasing radius of the inner arc until the width of the arc gauge is greater than the width of the tire's running surface. The width of the tire's running surface is the sum of the width of the tire crown and the width of the tire shoulders on both sides of the tire crown.

[0075] Specifically, during the replacement of the radii gauge, if the changing trend and magnitude of the distance between the inner arc and the tire crown, and the distance between the inner arc and the tire shoulder are the same, then the radii of the tire tread adopt a single-arc structure; otherwise, the radii of the tire tread do not adopt a single-arc structure.

[0076] Preferably, the contact between the arc gauge and the tire crown and the tire shoulders on both sides of the tire crown is checked, specifically as follows:

[0077] Place the inner arc of the radii ruler along the width of the tire tread and check whether there is a gap between the inner arc and the tire crown and the tire shoulder. If there is no gap or the gap value is not greater than a set threshold, it is considered to be in contact. If the gap value is greater than the set threshold, it is considered not to be in contact.

[0078] Specifically, the set thresholds include a crown setting threshold and a shoulder setting threshold. If there is a gap between the inner arc and the crown, and the gap value is not greater than the crown setting threshold, then it is considered contact. If there is a gap between the inner arc and the shoulder, and the sum of the gap values ​​between the inner arc and both shoulders is not greater than the shoulder setting threshold, then it is considered contact. The crown setting threshold is 1 mm, and the shoulder setting threshold is 2 mm.

[0079] Preferably, the point on the center line of the tire's running surface is designated as the center point of the tire crown, and the point where the tire crown meets the tire shoulder is designated as the shoulder point. The radii ruler contacts both the tire crown and the tire shoulder, including:

[0080] (1) There is no gap between the arc ruler and the center point of the tire crown and the tire shoulder point.

[0081] like Figure 7 As shown, when there is no gap between the arc ruler and the center point of the tire crown and the tire shoulder point, the radius of the inner arc of the arc ruler is used as the center arc radius of the tire crown.

[0082] (2) There is no gap between the arc ruler and the center point of the tire crown and the tire shoulder point on one side, and the arc ruler does not contact the tire shoulder point on the other side due to the tread groove.

[0083] When the tire tread has mixed tread grooves, causing the arc gauge to be unable to simultaneously contact the center point of the tire crown and the shoulder points on both sides, such as... Figure 8As shown, the arc ruler cannot contact one side of the shoulder point, and when measuring, the arc ruler is placed obliquely to avoid the groove that causes it to be unable to simultaneously contact the center point of the crown, the shoulder point on both sides, and the radius of the inner arc of the arc ruler is taken as the center arc radius of the crown. At the same time, the inclination of the arc ruler should be minimized.

[0084] (3) The arc ruler has no gap between the center point of the crown and the shoulder point, and there is a gap between the arc ruler and the part of the crown other than the center point, and the gap value is not greater than the set threshold value of the crown.

[0085] As shown in Figure 13 When there is a step difference between the arc ruler and the center point of the crown, the radius of the inner arc of the arc ruler that simultaneously contacts the center point of the crown and the shoulder point is taken as the center arc radius of the crown. At this time, the growth rates on both sides of the center point of the crown are different, and the thickness of the crown needs to be checked. If the left and right errors of the crown thickness or the arc difference caused by the belt skew seriously affect the taper of the tire, causing the tire to wear unevenly in use.

[0086] Specifically, first, the symmetry of the semi-finished product is confirmed, second, the accuracy of the molding machine is checked to ensure that the steel wire part and the rubber part are left-right symmetrical, and finally, vulcanization is ensured to be correct, avoiding vulcanization deviation, and ensuring that the left and right stretch deformation difference is minimized.

[0087] As shown in Figure 14 When the arc ruler does not contact the 1 / 4 of the crown, the radius of the inner arc of the arc ruler that simultaneously contacts the center point of the crown and the shoulder point is taken as the center arc radius of the crown. At this time, the pad rubber can be thinned to reduce the arc radius of the shoulder of the carcass and reduce the stretch rate of the shoulder to ensure normal stretch rate.

[0088] (4) The arc ruler has a gap between the center point of the crown, and the gap value is not greater than the set threshold value of the crown, and the arc ruler has a gap between the shoulder, and the sum of the gap values of the inner arc and the shoulder on both sides is not greater than the set threshold value of the shoulder.

[0089] As shown in Figure 16 The arc ruler has a gap a with the center point of the crown, and a gap b with one side of the shoulder, and b < 2 mm, and the arc ruler contacts the other side of the shoulder, where a = b / 2 < 1 mm. This case is prone to uneven wear or groove bottom cracking.

[0090] As shown in Figure 17As shown, the arc gauge has a gap a with the center point of the crown, a gap b with the shoulder on one side, and b < 1 mm, and a gap c with the shoulder on the other side, and c < 1 mm, wherein a = (b + c) / 2 < 1 mm, b + c < 2 mm. In this case, the groove bottom is prone to cracking or eccentric wear. The crown arc is adjusted, and the base thickness of the cross-sectional groove is checked.

[0091] (5) The arc gauge has no gap with the center point of the crown, and has a gap with the shoulder, and the sum of the gap values of the inner arc with the shoulders on both sides is not greater than the shoulder set threshold.

[0092] Preferably, the arc gauge contacts the crown and the shoulder, and further comprises: the arc gauge has a gap with the center point of the crown, and the center point of the crown is a region containing the center point of the crown, and the gap value is not greater than the crown set threshold, and the arc gauge has no gap with the shoulder point.

[0093] As shown, the arc gauge has a gap with the center point of the crown, and the center point of the crown is a region containing the center point of the crown, and the gap value is not greater than the crown set threshold, and the arc gauge has no gap with the shoulder point. Figure 15 The arc gauge has a gap with the center point of the crown, and the center point of the crown is a region containing the center point of the crown, and the gap value is not greater than the crown set threshold, and the arc gauge has no gap with the shoulder point.

[0094] Preferably, if the arc gauge does not contact the crown or the shoulder, specifically:

[0095] The arc gauge has no gap with the center point of the crown, and has a gap with the shoulder, and the sum of the gap values of the inner arc with the shoulders on both sides is greater than the shoulder set threshold;

[0096] The arc gauge has no gap with the center point of the crown, and has a gap with the shoulder, and the sum of the gap values of the inner arc with the shoulders on both sides is greater than the shoulder set threshold;

[0097] The arc gauge has a gap with the center point of the crown, and the gap value is not greater than the crown set threshold, and the arc gauge has a gap with the shoulder, and the sum of the gap values of the inner arc with the shoulders on both sides is greater than the shoulder set threshold.

[0098] The arc gauge has a gap with the center point of the crown, and the gap value is greater than the crown set threshold, and the arc gauge has a gap with the shoulder, and the sum of the gap values of the inner arc with the shoulders on both sides is not greater than the shoulder set threshold.

[0099] Preferably, the center arc radius of the crown and the connecting arc radius of the shoulder are measured respectively, specifically:

[0100] The arc gauges are replaced in sequence until the arc gauge contacts the crown and a first contact range exists, the first contact range is centered on the center point of the crown and covers 3 / 4 of the width of the crown, the inner arc radius of the arc gauge is the center arc radius of the crown, the contact is no gap or a gap exists between the inner arc and the crown, and the gap value is not greater than the set threshold value of the crown.

[0101] Here, the contact between the arc gauge and the crown includes: no gap between the arc gauge and the center point of the crown; no gap between the arc gauge and the center point of the crown, a gap exists between the arc gauge and the part of the crown other than the center point, and the gap value is not greater than the set threshold value of the crown; a gap exists between the arc gauge and the center point of the crown, and the gap value is not greater than the set threshold value of the crown; a gap exists between the arc gauge and the center point of the crown, and the gap value is not greater than the set threshold value of the crown.

[0102] As shown in Figure 9 , when the arc gauge and the shoulder exist a second contact range, the connecting arc radius of the shoulder is determined.

[0103] As shown in Figure 11 , when the first contact range exists between the steel ruler and the crown, it is recorded as a flat surface, at this time, the arc gauge cannot be used for measurement, and another steel ruler can be used for measurement.

[0104] As shown in Figure 12 , when the center position of the crown is concave to form a recess, causing the steel ruler to not contact the center point of the crown, the reverse arc is recorded, and the footprint presents a V shape. The shoulder growth rate of such a tire is large, causing the shoulder belt interlayer shear to increase, and early shoulder emptying is prone to occur. At this time, the arc gauge cannot be used for measurement, and the tread rubber thickness at the center position of the crown needs to be checked to avoid the occurrence of reverse arc.

[0105] The arc gauges are replaced in sequence until the arc gauge contacts the shoulder and a second contact range exists, the second contact range is centered on the shoulder point and covers 1 / 4 of the width of the shoulder, the inner arc radius of the arc gauge is the connecting arc radius of the shoulder, and the contact is no gap or a gap exists between the inner arc and the shoulder, and the gap value is not greater than the set threshold value of the shoulder.

[0106] As shown in Figure 10 , when the second contact range exists between the arc gauge and the shoulder, the connecting arc radius of the shoulder is determined.

[0107] The application is further configured that when the tire tread arc adopts a three-section arc structure, the transition shoulder is between the shoulder and the tire side, the measuring method of the transition arc radius of the transition shoulder is the same as the measuring method of the connecting arc radius of the shoulder, and specifically is:

[0108] The point at the joint of the shoulder and the transition shoulder is taken as a transition shoulder point, the arc gauges are replaced in sequence until the arc gauge contacts the transition shoulder and there is a third contact range, the third contact range takes the transition shoulder point as a starting point and covers 1 / 4 of the width of the transition shoulder, and the inner arc radius of the arc gauge is taken as the transition arc radius of the transition shoulder.

[0109] The application has been described in detail above, and the above description is only a preferred embodiment of the application, which cannot limit the scope of the application, that is, all equivalent changes and modifications made within the scope of the application should still fall within the scope of the application.

Claims

1. A method of measuring the camber of a TBR tread, characterized by, The application relates to a method for measuring the center arc radius and the connecting arc radius of a tire tread. The method comprises the following steps: placing an arc ruler along the width direction of the tire tread to determine the contact between the arc ruler and the crown and the shoulder on both sides of the crown; if the arc ruler contacts the crown and the shoulder, it indicates that the tire tread adopts a single-arc structure, and the radius of the arc ruler is taken as the center arc radius of the crown; if the arc ruler does not contact the crown or the shoulder, it indicates that the tire tread does not adopt a single-arc structure, and the center arc radius of the crown and the connecting arc radius of the shoulder are measured respectively; wherein the arc ruler is replaced in sequence until the arc ruler contacts the crown and a first contact range exists, the first contact range is centered on the center point of the crown and covers 3 / 4 of the width of the crown, and the inner arc radius of the arc ruler is taken as the center arc radius of the crown; 2. The method of claim 1, wherein, the arc ruler is replaced in sequence until the arc ruler contacts the shoulder and a second contact range exists, the second contact range is started from the shoulder point and covers 1 / 4 of the width of the shoulder, and the inner arc radius of the arc ruler is taken as the connecting arc radius of the shoulder.

3. A method of measuring the camber of a TBR tread as defined in claim 2, wherein, The longitudinal section of the arc ruler is in the shape of an arc, which comprises an inner arc and an outer arc, and the center arc radius and the connecting arc radius are determined according to the radius of the inner arc. The arc ruler is placed along the width direction of the tire tread, and the method comprises the following steps:

4. The method of claim 2, wherein the TBR tread arc measurement is determined by the equation: TBR = 2 * (R - r) / (R + r) where R is the radius of the TBR tire and r is the radius of the RPB tire. the arc ruler is replaced in sequence according to the increasing order of the radius of the inner arc until the width of the arc ruler is greater than the width of the tire running surface, and the width of the tire running surface is the sum of the width of the crown and the width of the shoulder. The contact between the arc ruler and the crown and the shoulder on both sides of the crown is observed, and the method comprises the following steps:

5. A method of measuring the camber of a TBR tread as defined in claim 4, wherein, the inner arc of the arc ruler is placed along the width direction of the tire tread, and it is observed whether there is a gap between the inner arc and the crown and the shoulder, if there is no gap or the gap value is not greater than the set threshold value of the crown between the inner arc and the crown, it is considered that the arc ruler contacts the crown, and if there is no gap or the gap value is not greater than the set threshold value of the shoulder between the inner arc and the shoulder, it is considered that the arc ruler contacts the shoulder. The center point of the crown is the point of the center line of the tire running surface, and the shoulder point is the point at the joint of the crown and the shoulder, and the arc ruler contacts the crown and the shoulder, which comprises the following steps: there is no gap between the arc ruler and the center point of the crown and the shoulder point; there is no gap between the arc ruler and the center point of the crown and the shoulder point on one side, and the arc ruler does not contact the shoulder point on the other side due to the pattern groove; there is no gap between the arc ruler and the center point of the crown and the shoulder point, and there is a gap between the arc ruler and the part of the crown except the center point, and the gap value is not greater than the set threshold value of the crown; there is a gap between the arc ruler and the center point of the crown, and the gap value is not greater than the set threshold value of the crown, and there is a gap between the arc ruler and the shoulder, and the sum of the gap values of the inner arc and the shoulder on both sides is not greater than the set threshold value of the shoulder. The arc gauge has no gap between the center point of the crown and the arc gauge, has a gap between the arc gauge and the shoulder, and the sum of the gap values of the inner arc and the two shoulders is not greater than the shoulder set threshold.

6. A method of measuring the camber of a TBR tread as defined in claim 5, wherein, The arc gauge contacts the crown, the shoulder, and further comprises: The arc gauge has a gap between the center point of the crown and the arc gauge, the center point of the crown is a region containing the center point of the crown, and the gap value is not greater than the crown set threshold, and the arc gauge has no gap between the arc gauge and the shoulder point.

7. The method for measuring the tread curvature of a TBR tire according to claim 4, characterized in that, If the arc gauge does not contact the crown or the shoulder, specifically: The arc gauge has no gap between the center point of the crown and the arc gauge, has a gap between the arc gauge and the shoulder, and the sum of the gap values of the inner arc and the two shoulders is not greater than the shoulder set threshold. The arc gauge has no gap between the center point of the crown and the arc gauge, and the arc gauge has a gap between the arc gauge and the part of the crown other than the center point, and the gap value is not greater than the crown set threshold, the arc gauge has a gap between the arc gauge and the shoulder, and the sum of the gap values of the inner arc and the two shoulders is greater than the shoulder set threshold. The arc gauge has a gap between the center point of the crown and the arc gauge, and the gap value is not greater than the crown set threshold, the arc gauge has a gap between the arc gauge and the shoulder, and the sum of the gap values of the inner arc and the two shoulders is greater than the shoulder set threshold. The arc gauge has a gap between the center point of the crown and the arc gauge, and the gap value is not greater than the crown set threshold, the arc gauge has a gap between the arc gauge and the shoulder, and the sum of the gap values of the inner arc and the two shoulders is greater than the shoulder set threshold.

8. A method of measuring the camber of a TBR tire tread as set forth in any one of claims 4-7, wherein, The arc gauge has a gap between the center point of the crown and the arc gauge, and the gap value is greater than the crown set threshold, the arc gauge has a gap between the arc gauge and the shoulder, and the sum of the gap values of the inner arc and the two shoulders is not greater than the shoulder set threshold. The crown set threshold is 1mm, and the shoulder set threshold is 2mm.

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