JP7339132B2 - Method for evaluating traction performance of pneumatic tires - Google Patents

Description

The present invention relates to a traction performance evaluation method for pneumatic tires.

Finite element analysis by the finite element method (FEM) is often used to evaluate the traction performance of pneumatic tires. Finite element analysis uses a finite element model in which the pneumatic tire to be evaluated is divided into a finite number of elements. Various characteristics including traction performance can be evaluated by setting material properties and boundary conditions for each element of the finite element model and executing the analysis. A tire performance prediction method for evaluating traction performance by finite element analysis is disclosed in Patent Document 1, for example.

JP 2014-210488 A

However, the finite element analysis method of Patent Document 1 requires the creation of a complicated finite element model. Since it takes a lot of time to create a finite element model, there is a demand for a simpler method for evaluating traction performance.

An object of the present invention is to evaluate the traction performance of a pneumatic tire by a simple method without performing complicated analysis or experiments in a method for evaluating the traction performance of a pneumatic tire.

The present invention acquires the groove dimensions of a pneumatic tire, acquires the ground contact width or tread width of the pneumatic tire on a flat road surface, and grounds the pneumatic tire based on the groove dimensions and the ground contact width or the tread width. A method for evaluating the traction performance of a pneumatic tire is provided, comprising calculating the volume of the groove in the range and evaluating the volume of the groove as the traction performance of the pneumatic tire.

According to this method, the volume of grooves in the contact area is evaluated as the traction performance of the pneumatic tire. Since the calculation of the groove volume does not involve complicated analysis or experiments, the traction performance of the pneumatic tire can be evaluated in a simple manner without conducting complicated analyzes or experiments. Especially in this method, since the traction performance is evaluated using only the volume of the groove, the traction performance can be evaluated very easily. Further, regarding the effectiveness of this method, the inventor of the present application has confirmed that there is a positive correlation between the volume of the groove and the traction performance, and has confirmed that this method is effective. Essentially, traction performance is affected by various factors other than the volume of the grooves, such as the shape and material of the tread portion. However, this method focuses only on the volume of the groove among various factors based on the knowledge about the above-mentioned effectiveness, and can easily and quickly evaluate the traction performance.

The volume of the groove may be the volume of the groove excluding a see-through portion, which is a portion that is linearly continuous in the circumferential direction of the tire.

According to this method, traction performance can be evaluated more accurately. The see-through portion is a portion of the groove that has little effect on traction performance. Grooves extending generally in the tire width direction (so-called lateral grooves) greatly contribute to traction performance. This is mainly due to the lateral grooves scratching the road surface when the pneumatic tire rolls. Therefore, the see-through portion, which is a portion that is linearly continuous in the tire circumferential direction, does not contribute much to the traction performance. Therefore, by excluding the see-through portion when calculating the volume of the groove, a more accurate evaluation is possible. The name of the see-through portion indicates the portion where the front can be seen without being blocked by the land portion when the tread portion is viewed along the tire circumferential direction.

An actual pneumatic tire may be prepared for obtaining the groove dimensions and the ground contact width or the tread width, and the groove dimensions may be obtained by measuring the actual pneumatic tire.

According to this method, accurate dimensions can be obtained by preparing a real pneumatic tire. Therefore, traction performance can be evaluated more accurately.

Shape data of the pneumatic tire may be prepared when obtaining the groove dimensions and the ground contact width or the tread width, and the groove dimensions may be obtained from the pneumatic tire shape data.

According to this method, by preparing the shape data of the pneumatic tire, the traction performance can be evaluated without preparing the actual pneumatic tire. Therefore, traction performance can be evaluated more easily. Such pneumatic tire shape data may be either two-dimensional data (tread pattern developed view) or three-dimensional data. However, in the case of two-dimensional data, the dimension of the depth of the groove is separately required.

The preparation of the shape data of the pneumatic tire may include restoring the shape data of the full width of the tire from the shape data of the half width of the tire.

According to this method, the traction performance can be evaluated by preparing only the shape data of the half width of the tire. In a symmetrical tread pattern such as line symmetry or point symmetry, it is often possible to restore the shape data for the full width of the tire from the shape data for the half width of the tire. In the above method, in such a case, the traction performance can be evaluated by restoring the shape data of the full width of the tire from the shape data of the half width of the tire.

Acquiring the dimensions of the groove may include discretely evaluating the depth of the groove in a plurality of steps.

According to this method, by evaluating the depth of the groove discretely rather than continuously, the calculation of the volume of the groove can be simplified, and the traction performance can be evaluated more easily.

The volume of the groove is calculated by calculating the cross-sectional area of the groove in the cross section in the tire circumferential direction at predetermined intervals in the tire width direction, multiplying each of the calculated cross-sectional areas of the groove by the predetermined interval, and adding them together. may include

According to this method, the volume of the groove can be calculated easily and reliably. In particular, by narrowing the predetermined interval, the volume of the groove can be calculated with high accuracy. Here, the tire circumferential cross section refers to a cross section perpendicular to the rotation axis of the pneumatic tire.

According to the present invention, in the pneumatic tire traction performance evaluation method, the groove volume is evaluated as the traction performance. Therefore, the traction performance of the pneumatic tire can be evaluated by a simple method without complicated experiments or analyses.

The perspective view which shows a tire assembly. A development view of two pitches of a pneumatic tire. FIG. 4 is a schematic developed view showing a see-through portion of another shape. 4 is a flowchart of a pneumatic tire traction performance evaluation method according to the first embodiment of the present invention. FIG. 5 is a block diagram of a pneumatic tire traction performance evaluation apparatus that executes the flowchart of FIG. 4 ; FIG. 3 is a developed view obtained by connecting the developed views of FIG. 2 for 6 pitches. Sectional drawing along the VII-VII line of FIG. Graph showing correlation between traction performance and groove volume. FIG. 3 is a developed view of the tire half width of FIG. 2 ; FIG. 10 is a developed view of the full width of the tire restored from the developed view of the half width of the tire in FIG. 9 ; 8 is a flowchart of a traction performance evaluation method for a pneumatic tire according to a second embodiment; FIG. 12 is a block diagram of a pneumatic tire traction performance evaluation apparatus that executes the flowchart of FIG. 11 ;

Embodiments of the present invention will be described below with reference to the accompanying drawings.

(First embodiment)
FIG. 1 is a perspective view showing a tire assembly 1. FIG. A tire assembly 1 is constructed by assembling a pneumatic tire 2 to a wheel rim 3 . In FIG. 1, illustration of the tread pattern is omitted for clarity of illustration. Further, in FIG. 1, the tire width direction is indicated by TW, and the tire circumferential direction is indicated by TC. This also applies to subsequent figures.

The traction performance evaluation method of the pneumatic tire 2 of this embodiment is a method of evaluating the traction performance using shape data of the pneumatic tire 2 . The traction performance refers to the driving and braking force performance that the pneumatic tire 2 exerts on the road surface.

FIG. 2 is a developed view of the pneumatic tire 2 for two pitches. Specifically, it is a developed view corresponding to the hatched portion of the pneumatic tire 2 in FIG. In FIG. 2, the dashed line extending in the tire width direction divides the shape data for two pitches into two shape data for one pitch. In the pneumatic tire 2, a plurality of pieces of shape data for one pitch are continuous in the tire circumferential direction to form a tread pattern for one round.

As shown in FIG. 2 , the pneumatic tire 2 has multiple grooves 4 . In FIG. 2, the hatched portions indicate the plurality of grooves 4, and the non-hatched portions indicate land portions. In this embodiment, the plurality of grooves 4 are formed in the same shape for each pitch.

The multiple grooves 4 include four main grooves 5 . The four main grooves 5 are so-called longitudinal grooves, and extend linearly and continuously along the tire circumferential direction. In this embodiment, the four main grooves 5 correspond to the see-through portion 6 . Here, the see-through portion 6 is a groove portion that is linearly continuous along the tire circumferential direction. The name of the see-through portion 6 indicates a portion where the front can be seen without obstruction of the line of sight by the land portion when the tread portion is viewed along the tire circumferential direction. In the present embodiment, the presence or absence of the see-through portion 6 is checked because the calculated traction performance differs depending on the presence or absence of the see-through portion 6 as will be described later.

In this embodiment, the four main grooves 5 as a whole correspond to the see-through portion 6, but part of them may correspond to the see-through portion 6 in some cases. For example, as shown in the schematic developed view of FIG. 3 , when two zigzag-shaped main grooves 5 are provided, one of the two main grooves 5 extends linearly along the tire circumferential direction. Only the continuous portion (see hatched portion) corresponds to the see-through portion 6 .

Referring again to FIG. 2 , the plurality of grooves 4 are provided with a plurality of sub-grooves 7 . The plurality of minor grooves 7 represent grooves other than the main groove 5, such as notches and lateral grooves, and have various shapes. None of the sub-grooves 7 has a portion extending linearly and continuously along the tire circumferential direction. That is, none of the sub-grooves 7 has the see-through portion 6 .

FIG. 4 is a flowchart of a traction performance evaluation method for the pneumatic tire 2 according to this embodiment. FIG. 5 is a block diagram of the pneumatic tire traction performance evaluation apparatus 10 that executes the flowchart of FIG.

The traction performance evaluation device 10 includes an input unit 11, a groove dimension acquisition unit 12, a contact width (tread width acquisition unit) 13, an all-around tread pattern acquisition unit 14, a groove volume calculation unit 15, a traction performance evaluation unit 16, and an output unit. 17. The input unit 11 is a part for inputting the shape data of the pneumatic tire 2, and may be a storage medium or the like storing the shape data or the like. The output unit 17 is a part that outputs evaluation results, and may be a display or the like. Each of the elements 12 to 16 is implemented by the cooperation of a processor, which is a hardware resource, and a program, which is software recorded in the processor, and is a part that executes the following traction performance evaluation method.

In this embodiment, first, when the shape data of the pneumatic tire 2 is input from the input unit 11, the groove size acquisition unit 12 determines the size of each of the plurality of grooves 4 of the pneumatic tire 2 based on the shape data. Acquire (step S41). Specifically, dimensions such as the width and depth of each of the plurality of grooves 4 are obtained from the shape data of the pneumatic tire 2 shown in FIG. As shown in FIG. 2, when the shape data of the pneumatic tire 2 is two-dimensional data, the depth of each of the plurality of grooves 4 cannot be obtained. is obtained separately from the input unit 11 . Although two-dimensional data is used in this embodiment, three-dimensional data may also be used. When using three-dimensional data, the depth of each of the plurality of grooves 4 can also be acquired from the shape data.

In this embodiment, the depth of each of the plurality of grooves 4 is discretely evaluated in a plurality of stages. In the example of FIG. 2, the depth of each of the plurality of acquired grooves 4 is evaluated in three stages, and different types of oblique lines are attached to grooves having three different depths. Alternatively, grooves of different depths may be colored with different colors. Further, evaluation of the depth of each of the plurality of grooves 4 is not limited to three stages, and may be two stages or four stages or more.

Next, the ground contact width (tread width acquisition unit) 13 acquires the ground contact width of the pneumatic tire 2 on a flat road surface (indicated by W1 in FIG. 2) (step S42). The contact width may be an estimated value from other pneumatic tires of the same size, or may be obtained by a simple and static contact analysis. At this time, data required for estimation and analysis are acquired from the input unit 11 . Further, for simplicity, the ground contact width may be replaced by the tread width (indicated by symbol W2 in FIG. 2). The contact width indicates the width when the pneumatic tire 2 contacts the road surface, and the tread width indicates the width of the tread portion of the pneumatic tire 2 .

Next, the tread pattern for one round of the pneumatic tire 2 is acquired by the full-circumference tread pattern acquiring unit 14 (step S43). In the example of FIG. 2, shape data for two pitches are shown, but a plurality of shape data for one pitch separated by dashed lines are connected to create a developed view of a tread pattern for one round. Further, if the tread pattern has a different scale for each pitch, a developed view of the tread pattern for one round is created by connecting a plurality of shape data while changing the scale for each pitch. If not only the reduced scale but also the shape differs for each pitch, shape data for a plurality of required pitches are prepared and connected to create a tread pattern for one round. In this embodiment, an example of creating a tread pattern for one round from shape data for one pitch has been shown, but a drawing of a tread pattern for one round may be prepared in advance.

Next, the volumes of the plurality of grooves 4 are calculated by the groove volume calculator 15 (step S44). The volume of the plurality of grooves 4 is calculated by calculating the cross-sectional area of each of the plurality of grooves 4 in the cross section in the tire circumferential direction at predetermined intervals in the tire width direction, and calculating the cross-sectional area of each of the plurality of grooves 4 at predetermined intervals. by multiplying and adding together. Here, the term “tire circumferential cross section” refers to a cross section perpendicular to the rotation axis CL (see FIG. 1) of the pneumatic tire 2 .

A method for calculating the volumes of the plurality of grooves 4 will be described in detail with reference to FIGS. FIG. 6 is a developed view obtained by connecting the shape data of FIG. 2 for six pitches. FIG. 7 is a cross-sectional view taken along line VII--VII of FIG. In FIG. 7, the tire radial direction is indicated by symbol TR. In FIG. 6, oblique lines like those in FIG. 2, which evaluate the depth of each of the plurality of grooves 4, are omitted for clarity of illustration.

In calculating the volumes of the plurality of grooves 4, first, the scale relationship between the image of the shape data and the pneumatic tire 2 is calculated. Specifically, from the number of pixels in the tire circumferential direction in the image for one pitch and the length in the tire circumferential direction for one pitch, it is calculated how many mm one pixel in the tire circumferential direction of the image corresponds to. Similarly, from the number of pixels in the tire width direction in the image for one pitch and the length in the tire width direction for one pitch, it is calculated how many mm one pixel in the tire width direction of the image corresponds to. Preferably, each pixel is 1 mm or less in both the tire circumferential direction and the tire width direction in order to accurately evaluate the traction performance.

Based on the scale relationship calculated as described above, in a certain cross section, a plurality of grooves approximated by rectangles from the tire circumferential direction length C1 of the plurality of grooves 4 and the tire radial direction depth R1 of the plurality of grooves 4 4 is obtained (S1=C1×R1). Here, the tire circumferential direction length C1 of the plurality of grooves 4 is the sum of the respective lengths of the plurality of grooves 4 in the cross section (C1=C11+C12+C13+C14+C15+...). This is performed on each cross section at predetermined intervals ΔW in the tire width direction. That is, the tire circumferential direction lengths C1, C2, C3, . ), the cross-sectional areas S1, S2, S3, . Then, by multiplying each of the calculated cross-sectional areas S1, S2, S3, . S1×ΔW+S2×ΔW+S3×ΔW+ . . . +Sn×ΔW). In this manner, the volumes V of the plurality of grooves 4 can be calculated easily and reliably. Preferably, by finely setting the predetermined interval ΔW (for example, 1 mm or less), the volumes V of the plurality of grooves 4 can be calculated with high accuracy. Moreover, in the plurality of grooves 4 in the cross section, the depth in the tire radial direction may exist in a plurality of steps. In that case, S1 = "total tire circumferential length with groove depth R1" x R1 + "total tire circumferential length with groove depth R2" x R2 + "tire circumferential direction tire groove depth R3" Total length"×R3. Note that this calculation is for the case where the groove depth is evaluated in three stages R1 to R3, but the groove depth may be evaluated in stages other than the three stages.

Preferably, in calculating the volume V of the plurality of grooves 4, the volume V of the plurality of grooves 4 excluding the see-through portion 6 is calculated. As a method of excluding the see-through portion 6 from the calculation target in the calculation of the volume V of the plurality of grooves 4, for example, in FIGS. , . . For example, if the tire circumferential direction length C2 of the plurality of grooves 4 in a specific cross section coincides with the length of the entire tire circumference, the groove displayed in this specific cross section is the see-through portion 6, which is the object of calculation. (V=S1×ΔW+S3×ΔW+ . . . +Sn×ΔW). As a result, the four main grooves 5 are excluded from the calculation of the volume V of the plurality of grooves 4 , that is, the volume of the plurality of sub grooves 7 is calculated as the volume V of the plurality of grooves 4 . Moreover, in the plurality of grooves 4 in the cross section, the depth in the tire radial direction may exist in a plurality of steps. In that case, "Total circumferential length of tire with groove depth R1" + "Total circumferential length of tire with groove depth R2" + "Total circumferential length of tire with groove depth R3" ” matches the length of the entire circumference of the pneumatic tire 2, this is excluded from the calculation target as the see-through portion 6. Note that this calculation is for the case where the groove depth is evaluated in three stages R1 to R3, but the groove depth may be evaluated in stages other than the three stages as described above.

Next, the traction performance evaluation unit 16 evaluates the volume V of the plurality of grooves 4 calculated as described above as the traction performance (step S45). This evaluation result is output from the output unit 17 . That is, the larger the volume V of the plurality of grooves 4 is, the better the traction performance is evaluated.

FIG. 8 is a graph comparing the volumes V of the plurality of grooves 4 obtained in this way and the traction performance evaluated by finite element analysis. The horizontal axis of the graph in FIG. 8 indicates the volume V of the plurality of grooves 4, and the vertical axis indicates the traction performance evaluated by actually creating a finite element model and analyzing it. The results of such comparison of 15 types of tires are shown as 15 points of data on the graph. The straight line in the graph is obtained by approximating the 15 points of data by the method of least squares.

By checking the graph, it can be seen that there is a positive correlation between the volume V of the plurality of grooves 4 and the traction performance evaluated by the finite element analysis. Therefore, a certain reliability was confirmed for evaluating the volume V of the plurality of grooves as the traction performance. Essentially, the traction performance is affected by various factors other than the volume V of the plurality of grooves 4, such as the shape and material of the tread portion. However, based on this knowledge of effectiveness, the traction performance evaluation method of the present embodiment focuses only on the volume V of the plurality of grooves 4 among various factors, and can easily and quickly evaluate the traction performance.

According to this embodiment, the volume V of the plurality of grooves 4 in the contact area is evaluated as the traction performance of the pneumatic tire 2 . Since the calculation of the volume V of the plurality of grooves 4 does not involve complicated analysis or experiments, the traction performance of the pneumatic tire 2 can be evaluated by a simple method without conducting complicated analyzes or experiments. Especially in this method, since the traction performance is evaluated using only the volume V of the plurality of grooves 4, the traction performance can be evaluated extremely easily. Since the traction performance can be easily evaluated in this way, the engineer who designs the pneumatic tire 2 can determine the deformation position, the deformation method, and the deformation position of the grooves of the tread pattern based on the evaluation result of the traction performance thus obtained. Alternatively, by changing the amount of deformation, etc., the pneumatic tire 2 having suitable traction performance can be quickly designed.

Further, by excluding the see-through portion 6 from the calculation target in the calculation of the volume V of the plurality of grooves 4, the traction performance can be evaluated more accurately. The see-through portion 6 is a portion of the plurality of grooves 4 that has less influence on the traction performance. Grooves extending generally in the tire width direction (so-called lateral grooves) greatly contribute to traction performance. This is mainly due to the lateral grooves scratching the road surface when the pneumatic tire 2 rolls. Therefore, the see-through portion 6, which is a portion that is linearly continuous in the tire circumferential direction, does not contribute much to the traction performance. Therefore, when calculating the volume V of the plurality of grooves 4, more accurate evaluation is possible by excluding the see-through portion 6. FIG. The name of the see-through portion 6 indicates the portion where the front can be seen without the land portion blocking the line of sight when the tread portion is viewed along the tire circumferential direction.

Moreover, in this embodiment, the shape data of the pneumatic tire 2 is used instead of using the actual pneumatic tire 2 . Therefore, the traction performance can be evaluated without preparing the actual pneumatic tire 2 . Therefore, traction performance can be evaluated more easily.

Further, in this embodiment, the depth of each of the plurality of grooves 4 is evaluated discretely rather than continuously. Therefore, the calculation of the volume V of the plurality of grooves 4 can be simplified, and the traction performance can be evaluated more easily. However, when more accurate traction performance evaluation is required, the depth of each of the plurality of grooves 4 may be evaluated continuously.

(Modification)
FIG. 9 shows shape data of the tire half width of the pneumatic tire 2 of FIG. The pneumatic tire 2 of FIG. 2 is formed point-symmetrically for each pitch. Therefore, as shown in FIG. 10, the shape data of the full width of the tire can be restored by connecting the shape data of the half width of the tire in point symmetry. In FIG. 10, the reconstructed right half is indicated by dashed lines.

Thus, the shape data of the full width of the tire is not necessarily required, and in step S43, the shape data of the full width of the tire may be restored from the shape data of the half width of the tire by the full circumference tread pattern acquisition unit 14 . In addition to the point-symmetrical patterns shown in FIGS. 9 and 10, line-symmetrical patterns (or directional patterns) can be used to restore the shape data of the full width of the tire from the shape data of the half-width of the tire. Moreover, even if the tread pattern is not completely point-symmetrical or line-symmetrical, the tread pattern of the entire width of the tire may be restored by moving the grooves in the tire circumferential direction by a certain amount from the point-symmetrical or line-symmetrical position.

According to this modified example, the traction performance can be evaluated by preparing only the shape data of the half width of the tire.

(Second embodiment)
The traction performance evaluation method of the pneumatic tire 2 of the second embodiment uses the actual pneumatic tire 2 instead of the shape data to evaluate the traction performance. Except for this, it is substantially the same as the traction performance evaluation method of the pneumatic tire 2 of the first embodiment. Therefore, the description of the same parts as those shown in the first embodiment may be omitted.

FIG. 11 is a flowchart of a traction performance evaluation method for the pneumatic tire 2 according to this embodiment. FIG. 12 is a block diagram of a pneumatic tire traction performance evaluation device 20 that executes the flowchart of FIG.

The traction performance evaluation device 20 includes an input section 21 , a groove volume calculation section 22 , a traction performance evaluation section 23 and an output section 24 . The input unit 21 is a portion for inputting the dimensions of the groove, the contact width, and the like of the pneumatic tire 2, and may be a storage medium or the like storing the dimensions of the groove, the contact width, and the like. Alternatively, the input unit 21 may be an input device such as a keyboard capable of inputting the dimensions of the groove, the ground width, and the like. The output unit 24 is a part that outputs evaluation results, and may be a display or the like. Each of the elements 22 and 23 is implemented by the cooperation of a processor, which is a hardware resource, and a program, which is software recorded in the processor, and is a part that executes the following traction performance evaluation method.

In this embodiment, first, the dimensions of each of the plurality of grooves 4 of the pneumatic tire 2 are acquired (step S111). In this embodiment, the dimensions of each of the plurality of grooves 4 are acquired by measuring the actual pneumatic tire 2 . For example, dimensions such as width and depth of each of the plurality of grooves 4 may be measured by a non-contact measuring device such as a laser displacement meter. The measured dimensions may be discretely evaluated in multiple steps as in the first embodiment.

Next, the contact width of the pneumatic tire 2 on the flat road surface is obtained (step S112). Acquisition of the ground contact width can be easily performed by actually performing measurement on a flat road surface using the actual pneumatic tire 2 . If the actual pneumatic tire 2 can be prepared, the contact width can be easily measured, so there is no need to substitute the tread width as in the first embodiment.

Next, the dimensions and contact widths of the plurality of grooves 4 acquired as described above are input from the input unit 21, and the volume V of the plurality of grooves 4 is calculated by the groove volume calculation unit 22 (step S113). Calculation of the volume V of the plurality of grooves 4 is substantially the same as in the first embodiment.

Next, the traction performance evaluation unit 23 evaluates the volumes V of the plurality of grooves 4 calculated as described above as traction performance (step S114). That is, the larger the volume V of the plurality of grooves 4 is, the better the traction performance is evaluated. This evaluation result is output from the output unit 24 .

According to this embodiment, it is possible to obtain accurate dimensions by preparing the actual pneumatic tire 2 . Therefore, traction performance can be evaluated more accurately.

As described above, specific embodiments and modifications thereof of the present invention have been described, but the present invention is not limited to the above embodiments, and various changes can be made within the scope of the present invention. For example, the method of calculating the volume V of the plurality of grooves 4 is not limited to those of the above embodiments, and any method can be adopted. For example, the volume V of the plurality of grooves 4 may be calculated by subtracting the volume of the land portion and the volume of the see-through portion 6 from the volume of the non-patterned tread portion. Further, in each of the above embodiments, the traction performance evaluation method is executed by the traction performance evaluation devices 10 and 20 as an example, but the traction performance evaluation method of each of the above embodiments can also be executed by manual calculation.

REFERENCE SIGNS LIST 1 tire assembly 2 pneumatic tire 3 wheel rim 4 groove 5 main groove (longitudinal groove)
6 see-through portion 7 sub-groove 10 traction performance evaluation device 11 input portion 12 groove dimension acquisition portion 13 contact width acquisition portion (tread width acquisition portion)
14 Circumference Tread Pattern Acquisition Section 15 Groove Volume Calculation Section 16 Traction Performance Evaluation Section 17 Output Section 20 Traction Performance Evaluation Device 21 Input Section 22 Groove Volume Calculation Section 23 Traction Performance Evaluation Section 24 Output Section

Claims (7)

Get the tread dimensions of a pneumatic tire,
Obtaining the contact width or tread width of the pneumatic tire on a flat road surface,
calculating the volume of the groove in the contact area based on the dimensions of the groove and the contact width or the tread width;
A method for evaluating the traction performance of a pneumatic tire, comprising evaluating the volume of the groove as the traction performance of the pneumatic tire. 2. The method for evaluating traction performance of a pneumatic tire according to claim 1, wherein the volume of said groove is the volume of said groove excluding a see-through portion, which is a portion of said groove which is linearly continuous in the tire circumferential direction. preparing a real pneumatic tire when obtaining the groove dimensions and obtaining the ground contact width or the tread width;
3. The method for evaluating traction performance of a pneumatic tire according to claim 1, wherein the dimension of the groove is obtained by measuring the actual pneumatic tire. preparing shape data of a pneumatic tire when acquiring the groove dimensions and acquiring the ground contact width or the tread width;
3. The pneumatic tire traction performance evaluation method according to claim 1, wherein the groove dimensions are acquired from the shape data of the pneumatic tire. 5. The pneumatic tire traction performance evaluation method according to claim 4, wherein the preparation of the shape data of the pneumatic tire includes restoring the shape data of the full width of the tire from the shape data of the half width of the tire. The pneumatic tire traction performance evaluation method according to any one of claims 3 to 5, wherein acquiring the groove dimensions includes discrete evaluation of the groove depth in a plurality of steps. The volume of the groove is calculated by calculating the cross-sectional area of the groove in the cross section in the tire circumferential direction at predetermined intervals in the tire width direction, multiplying each of the calculated cross-sectional areas of the groove by the predetermined interval, and adding them together. The method for evaluating traction performance of a pneumatic tire according to any one of claims 3 to 6, comprising:

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