JP6642041B2 - Tire abrasion test method and running test path used for abrasion test - Google Patents

Description

  The present invention relates to a wear test method capable of easily and accurately performing a tire wear test, and a running test road used for the wear test.

  Tire wear includes, for example, cracks generated at the bottom corners (corners) of the groove-shaped portion provided on the tread portion due to lateral force during cornering, driving force or braking force during driving / braking. As it grows, there is chipping wear in which the tread rubber of the tread portion is turned into a scaly shape. Conventionally, tests of each wear including such chipping wear have been performed using, for example, a drum type bench test machine having a simulated road surface on which tires run.

  However, such a wear test method has a problem that, for example, chipping wear cannot be easily generated, and a wear test cannot be performed accurately. Related techniques include the following Patent Documents 1 and 2.

JP 2013-88309 A JP 2014-112047 A

  The present invention has been devised in view of the above situation, and is based on the fact that it includes an idling step of driving a tire fitted in a concave portion provided on a running test road and idling to easily and accurately wear the tire. It is a primary object of the present invention to provide a wear test method capable of performing a test and a running test path used in a wear test.

  The present invention is a method for testing abrasion of a tire, comprising a driving step of driving the tire on a running test path including a recess in which the tire fits, wherein the driving step includes fitting the tire into the recess. It is characterized by including an idling step of idling.

  In the wear test method according to the present invention, it is preferable that in the idling step, the rotational speed of the tire be 20 to 50 km / h.

  In the wear test method according to the present invention, it is preferable that the running test path includes a slope having a slope, and the driving step includes a moving step of moving the tire on the slope without passing through the recess. .

  In the wear test method according to the present invention, it is preferable that, in the moving step, the moving speed of the tire be 10 km / h or less.

  In the wear test method according to the present invention, it is preferable that the tire be mounted on a vehicle.

  The present invention relates to a running test road used for a tire wear test, wherein the running test road is a rubble road surface on which stones and gravel are laid, and the running test road has a recess in which the tire fits. Is provided.

  It is preferable that the traveling test road according to the present invention includes a slope having a slope, and the concave portion is provided on the slope.

  In the running test road according to the present invention, the concave portion has a length along the slope of the slope of 110% to 300% of the outer diameter of the tire and a depth of 20% to 40% of the outer diameter of the tire. % Is desirable.

  In the running test road according to the present invention, it is preferable that the length of the concave portion in the width direction of the slope is 110% to 300% of the maximum width of the tire.

  In the running test road according to the present invention, it is preferable that the concave portion has a bottom surface in contact with a tread surface of the tire, and the bottom surface has an arc shape that protrudes downward along the slope along the slope.

  The wear test method according to the present invention includes a driving step of driving the tire on a running test path including a concave portion into which the tire fits. The driving process includes an idling step of idling the tire fitted in the recess. Such a slipping step can easily cause the tire to wear, including chipping wear. Therefore, the wear test method of the present invention can easily and accurately test the wear performance.

It is a perspective view showing the outline of the abrasion test method of one embodiment of the present invention. It is a flowchart of a wear test method. It is a top view of a driving test road. It is sectional drawing of the slope containing a recessed part.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the tire wear test method of the present embodiment is a method of performing a tire wear test outdoors. For example, a tire S is mounted on a vehicle S equipped with a tire T on a running test road (hereinafter simply referred to as a test road). It may be referred to as a “test road”.) The tire is driven by R to perform a tire wear test.

  The tire T used in the wear test method of the present embodiment includes, for example, various categories of tires such as heavy load tires, passenger car tires, and non-pneumatic tires.

  As shown in FIG. 1, a test road R used in the wear test method of the present embodiment (hereinafter, may be simply referred to as “test method”) is a rubble road on which stones 10 and gravel 11 are laid. It is formed as. In such a test road R, various kinds of wear such as heel-and-toe wear and center wear of the tire T can be easily generated, but it is particularly suitable for generating chipping wear. As used herein, stone refers to minerals having a larger particle size, and gravel refers to minerals having a smaller particle size than stone.

  The test road R includes, for example, a slope 1 having a slope, a lower surface 2 connected to the lower end of the slope 1 and having a smaller slope than the slope 1, and an upper surface 3 connected to the upper end of the slope 1 and having a smaller slope than the slope 1. And The vehicle S can move from the lower surface 2 through the slope 1 to the upper surface 3. The lower surface 2 and the upper surface 3 of the present embodiment are connected by a gentle slope (not shown) having a smaller slope than the slope 1, and the vehicle S can also move up and down the gentle slope.

  The slope 1 of the present embodiment is provided with a recess 4 into which the tire T can be fitted. At least one concave portion 4 is provided on the slope 1, and in the present embodiment, one concave portion 4 is provided.

  FIG. 2 shows a flow of the test method of the present embodiment. The wear test method of the present embodiment includes a driving step of driving the tire T on the test road R.

  First, a tire T1 to be subjected to a wear test (hereinafter, simply referred to as a “test tire”) is mounted as a driving wheel of the vehicle S. That is, when the vehicle is for front wheel drive, the test tire T1 is mounted as a front wheel, and when the vehicle is for rear wheel drive, the test tire T1 is mounted as a rear wheel. The vehicle is provided with a display device having a well-known structure that measures and displays, for example, the rotational speed of the test tire T1 and the rotational speed of the test tire T1. The “rotation speed” in this specification is the rotation speed at the outermost end in the tire radial direction of the test tire T1.

  Next, a positioning step S1 for positioning the vehicle S is performed. In the positioning step S1, the vehicle S is moved to the slope 1 and the test tire T1 is fitted into the recess 4. At this time, the vehicle S is moved by driving the tire T.

  Next, a driving step of driving the test tire T1 is performed. In the present embodiment, the driving step includes an idling step S2 for idling the test tire T1 fitted in the recess 4, and a moving step S4 for moving the tire T. In the present embodiment, first, the idling step S2 is performed.

  In the idling step S2, the accelerator operation is performed on the vehicle S to spin the test tire T1 in the concave portion 4. As described above, in the wear test of the present embodiment, the idling step S2 is performed by using the concave portion 4 provided on the slope 1, so that the movement of the vehicle S is suppressed, and the test tire T1 can be surely idled. it can. For this reason, since a large frictional force is applied to the tread portion Ta, chipping wear and the like can be easily generated.

  As shown in FIG. 1, the slope 1 of the slope 1 having the concave portion 4 is desirably 20 to 40 °. Such a slope 1 can suppress the vehicle S from moving from the concave portion 4 when the test tire T1 idles, so that an accurate wear test can be performed. When the inclination is smaller than 20 °, the tire T may move from the concave portion 4 to the upper surface 3 side even by a small grip force generated when the tire T mounted on the vehicle S idles. When the inclination exceeds 40 °, when the test tire T1 is idled, the vehicle S may move to the lower surface 2 side.

  As shown in FIG. 3, the length L1 of the recess 4 along the slope 1 is preferably 110% to 300% of the outer diameter La of the tire. When the length L1 of the concave portion 4 is less than 110% of the outer diameter La of the tire, the area of the bottom surface 4a in contact with the tread portion Ta of the test tire T1 becomes small. For this reason, since the change in the contact position between the tread portion Ta and the bottom surface 4a is small, there is a possibility that the tread portion Ta may be unevenly worn. When the length L1 of the concave portion 4 of the test tire T1 exceeds 300% of the outer diameter La of the tire, the test tire T1 may be easily detached from the concave portion 4. From the same viewpoint, it is desirable that the depth D1 (shown in FIG. 4) of the concave portion 4 is 20% to 40% of the outer diameter La of the tire. The length L1 of the concave portion 4 is a distance along the slope 1 on which the test tire T1 can move within the concave portion 4, and the depth D1 of the concave portion 4 is a depth at which the test tire T1 can be fitted.

  As shown in FIG. 4, it is desirable that the concave portion 4 has an arc shape in which the bottom surface 4 a protrudes downward of the slope 1 along the slope. As a result, the contact area of the test tire T1 with the tread portion Ta increases, so that uniform wear can be given. Therefore, chipping wear can be generated with high accuracy.

  The rotation speed of the test tire T1 in the idling step S2 is preferably 20 to 50 km / h. When the rotation speed of the test tire T1 is less than 20 km / h, the grip force of the test tire T1 is increased, and the test tire T1 may be detached from the concave portion 4. If the rotational speed of the test tire T1 exceeds 50 km / h, the frictional heat of the test tire T1 increases, and the tread Ta is thermally deformed, so that chipping wear and the like may not be accurately reproduced. More preferably, the rotation speed of the test tire T1 is constant.

  The rotation number of the test tire T1 is desirably 100 to 300 times. When the number of revolutions of the test tire T1 is less than 100 times, the stress acting on the test tire T1 becomes small, and chipping wear or the like may not be generated. When the number of rotations of the test tire exceeds 300, the stress acting on the test tire T1 becomes excessively large, and the frictional heat generated in the test tire T1 increases, so that the tread portion Ta may be thermally deformed.

  Next, a confirmation step S3 for confirming the state of occurrence of wear of the test tire T1 is performed. In the confirmation step S3, for example, the state of occurrence of chipping wear is confirmed. Here, when chipping wear does not occur in the entire tread portion Ta (N in S3), the moving step S4 of the driving process is performed.

  In the moving step S4, the test tire T1 is climbed up from the recess 4 and the vehicle S is moved up and down on the slope 1 without the recess 4. Thereby, the frictional heat in the idling step S2 of the test tire T1 is removed, and the thermal deformation of the tread portion Ta is suppressed. In the moving step S4, the vehicle S is moved from the concave portion 4 to the upper surface 3, and then descends to the concave portion 4. In the moving step S4, the method is not limited to such a method. The vehicle S is moved from the concave portion 4 to the upper surface 3, then descends to the lower surface 2, and further moved to the concave portion 4 side. Alternatively, the vehicle S may be moved on the gentle slope.

  In the moving step S4, it is desirable that the moving speed of the test tire T1 on the slope 1, that is, the speed of the vehicle S be set to 10 km / h or less. If the moving speed of the test tire T1 exceeds 10 km / h, the tread Ta may be unevenly worn. Further, the frictional heat generated in the test tire T1 may not be removed. When the moving speed of the test tire T1 is low, the traveling time in the moving step S4 becomes excessively long. Therefore, the moving speed is desirably 5 km / h or more. The moving step S4 is usually performed for 5 to 10 minutes.

  In the moving step S4, the length L of the slope 1 is desirably about 50 to 200 m in order to effectively remove the frictional heat of the test tire T1 and efficiently perform the wear test.

  Next, the positioning step S1, the idling step S2 are performed again, and the confirmation step S3 is performed. Then, in the confirmation step S3, for example, if chipping wear or the like has occurred in the entire tread portion Ta (Y in S3), the wear performance test on the test tire T1 ends. It should be noted that also in this confirmation step S3, if chipping wear or the like does not occur on the entire tread portion Ta (N in S3), a movement step S4, a positioning step S1, an idling step S2, and a confirmation step S3 are further performed. .

  In addition, different test tires T1 are mounted on the same vehicle S, and a wear test is performed in the same manner as in steps S1 to S4. By comparing the conditions of wear such as chipping wear generated on both tires, the two tires are compared. Can be evaluated for wear performance.

  As mentioned above, although the tire test method and the running test path used for the wear test of the present invention have been described in detail, the present invention is not limited to the above specific embodiments, but may be modified in various forms. It goes without saying that it can be implemented. For example, in the abrasion test, the test in each of steps S1 to S4 may be performed by mounting the tire T on a moving device (not shown) that rotatably supports the tire T and moves on a running test road without using a vehicle. good.

In order to confirm the effects of the present invention, an appearance test was performed to confirm the state of wear generated on the tread portion of the tire by the wear test method of the present embodiment. In the wear test of the comparative example, the time spent in the idling step of Example 1 was spent in the moving step. The common specifications are as follows.
Vehicle: 2500cc
Driving test road: rubble road Slope of driving test road: 30 °
Slope length L: 120m
Length L1 along the slope of the slope of the concave portion: 150% of the outer diameter La of the tire
Depth of recess D1: 30% of outer diameter La of tire
The width W1 of the slope of the recess in the width direction is 150% of the maximum width Wa of the tire.

The evaluation of the appearance test is as follows.
Mainly chipping wear occurs on the entire circumference of the tire in the circumferential direction of the tread, and the tire is not deformed due to frictional heat. 3 points Mainly chipping wear occurs at multiple places in the tread, and deformation due to frictional heat occurs. Scattered tires ... 2 points Tires with no chipping wear on the tread ... 1 point

  As a result of the test, in the abrasion test of the example, chipping abrasion could be easily generated as compared with the abrasion test of the comparative example. Accordingly, it can be understood that the wear test method of the present embodiment can perform a wear test with high accuracy. The test was conducted by changing the tread pattern of the tire and the components of the tread rubber, and the same result was obtained.

DESCRIPTION OF SYMBOLS 1 Slope 4 Concave part 10 Stone 11 Gravel R Running test road T Tire

Claims (9)

A method for testing wear of a tire,
A driving step of driving the tire on a running test road including a recess in which the tire fits,
The driving step includes an idling step of idling the tire fitted in the recess,
The running test road includes a slope having a slope,
The abrasion test method according to claim 1, wherein the driving step includes a moving step in which the tire rides on the concave portion and climbs up and down on the slope without the concave portion .   The wear test method according to claim 1, wherein in the idling step, a rotation speed of the tire is 20 to 50 km / h.   The wear test method according to claim 1, wherein the moving speed of the tire is 10 km / h or less in the moving step.   The wear test method according to claim 1, wherein the tire is mounted on a vehicle. A driving test road used for a tire wear test,
The running test road is a rubble road on which stones and gravel are laid,
The running test road is provided with a recess in which the tire fits,
The running test road includes a slope having a slope,
The running test road, wherein the slope includes a portion where the tire moves without passing through the concave portion.   The running test road according to claim 5, wherein the concave portion is provided on the slope.   The running according to claim 6, wherein the concave portion has a length along the slope of the slope of 110% to 300% of the outer diameter of the tire and a depth of 20% to 40% of the outer diameter of the tire. Test road.   The running test road according to claim 6, wherein the concave portion has a length in the width direction of the slope of 110% to 300% of a maximum width of the tire. The recess has a bottom surface in contact with a tread surface of the tire,
The running test road according to any one of claims 5 to 8, wherein the bottom surface has an arc shape that protrudes below the slope along the slope.

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