JP7063350B2 - Stud pins and tires with them - Google Patents

Description

The present invention relates to a stud pin and a tire provided with the stud pin, and more particularly to a stud pin capable of enhancing the edge effect and improving the performance on ice and a tire provided with the stud pin.

Among pneumatic tires having improved running performance on ice and snow road surfaces, stud tires (spike tires) in which stud pins are driven into the tread portion are known (see, for example, Patent Documents 1 to 3). The stud pin has a buried base embedded in the tread portion of the tire and a tip portion located on the distal end side of the embedded base portion and in contact with the road surface. When the stud tire is running, the edge of the tip of the stud pin comes into contact with the icy road surface, and the edge effect is exerted to exhibit excellent on-ice performance.

However, conventional stud pins and tires equipped with them do not necessarily have sufficient on-ice performance because the edge effect of each stud pin is not sufficient. Therefore, further improvement of on-ice performance is required.

Japanese Patent No. 5702817 Japanese Patent No. 5997518 Japanese Patent No. 6111010

An object of the present invention is to provide a stud pin capable of enhancing the edge effect and improving the performance on ice and a tire provided with the stud pin.

The stud pin of the present invention for achieving the above object has a buried base embedded in the tread portion of the tire and a tip portion located on the tip end side of the buried base portion and in contact with the road surface. In a stud pin in which the metal material constituting the portion is harder than the metal material constituting the buried base and the buried base portion and the tip portion are integrally processed , the tip portion is formed with an outer shell formed in an annular shape. It is characterized in that it includes an inner shell surrounded by the outer shell and a groove portion interposed between the outer shell and the inner shell, and the groove portion is continuous in an annular shape around the inner shell .

Further, the tire of the present invention for achieving the above object is characterized in that the above-mentioned stud pin is arranged in the tread portion.

In the present invention, the tip of the stud pin is provided with an outer shell formed in an annular shape, an inner shell surrounded by the outer shell, and a groove portion interposed between the outer shells, whereby the outer shell and the inner shell each form an edge. Therefore, the edge effect of the stud pin can be significantly enhanced and the on-ice performance of the tire can be effectively improved. In particular, when the tip of the stud pin is composed of an annular outer shell and an inner shell surrounded by the annular outer shell, it is possible to secure sufficient strength for each of the outer shell and the inner shell.

In the present invention, it is preferable that the groove portion is continuous in an annular shape around the inner shell. In this case, the edge effect can be enhanced and the performance on ice can be effectively improved .

The inner shell preferably has an inner groove extending along the outer peripheral edge thereof. In this case, since the amount of edges is further increased, the performance on ice can be effectively improved.

It is preferable that the inner peripheral shape of the outer shell and the outer peripheral shape of the inner shell are different from each other. In this case, the snow-removing ice property of the tip of the stud pin can be improved, and the on-ice performance can be further improved by increasing the amount of edges. The inner peripheral shape of the outer shell and the outer peripheral shape of the inner shell may be similar to each other. In this case as well, sufficient edge effect can be expected.

The distance Ly between the outer shell and the inner shell measured in the direction orthogonal to the stud pin central axis is preferably in the range of 10% to 35% of the outer shell dimension Lx measured in the direction orthogonal to the stud pin central axis. .. As a result, the strength of the stud pin can be sufficiently ensured, and deterioration of snow-removal ice-removing property and workability can be avoided.

Further, the inner hull includes the inner hull body located on the innermost side, and the dimension Lz of the inner hull body measured in the direction orthogonal to the stud pin central axis is the dimension of the outer hull measured in the direction orthogonal to the stud pin central axis. It is preferably in the range of 10% to 60% of Lx. As a result, the strength of the stud pin can be sufficiently ensured, and deterioration of snow-removal ice-removing property and workability can be avoided.

The tire of the present invention is preferably a pneumatic tire, but may be a non-pneumatic tire. In the case of a pneumatic tire, the inside thereof can be filled with an inert gas such as air or nitrogen or other gas.

It is a perspective view which shows the stud pin which consists of embodiment of this invention. It is a top view which shows the stud pin of FIG. It is a side view which shows the stud pin of FIG. FIG. 2 is a cross-sectional view taken along the line IV-IV in FIG. It is a top view which shows the deformation example (reference example) of a stud pin. It is a top view which shows the other modification of a stud pin. It is a top view which shows the other modification of a stud pin. It is a top view which shows the other modification of a stud pin. It is a cross-sectional view of the meridian which shows an example of the pneumatic tire of this invention.

Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings. 1 to 4 show stud pins according to an embodiment of the present invention.

As shown in FIGS. 1 to 4, the stud pin P of the present embodiment has a buried base portion 10 embedded in the tread portion of the tire and a tip portion located on the tip end side of the buried base portion 10 and in contact with the road surface. It has 20 tires. The buried base 10 is connected to a columnar body portion 11, a columnar shank portion 12 connected to the body portion 11 and having a smaller diameter than the body portion 11, and a shank connected to the shank portion 12. It is composed of a columnar bottom portion 13 having a diameter larger than that of the portion 12. The metal material constituting the tip portion 20 has a higher hardness than the metal material constituting the buried base portion 10, and the buried base portion 10 and the tip portion 20 are integrally processed.

In the stud pin P, the tip portion 20 has an outer shell 21 formed in an annular shape, a columnar inner shell 22 surrounded by the outer shell 21, and a groove portion interposed between the outer shell 21 and the inner shell 22. It is equipped with 23. That is, edges are formed at the outer peripheral end and the inner peripheral end of the outer shell 21 on the ground plane, respectively, and edges are also formed at the outer peripheral end of the inner shell 22 on the ground plane.

As described above, the tip portion 20 of the stud pin P includes the outer shell 21 formed in an annular shape, the inner shell 22 surrounded by the outer shell 21, and the groove portion 23 interposed therein, whereby the outer shell 21 and the inner shell 21 and the inner shell 21 are provided. Since each of the 22 forms an edge, the edge effect of the stud pin P can be significantly enhanced and the on-ice performance of the tire can be effectively improved. In particular, when the tip of the stud pin P is composed of an annular outer shell 21 and an inner shell 22 surrounded by the annular outer shell 21, it is possible to secure sufficient strength for each of the outer shell 21 and the inner shell 22.

As shown in FIG. 2, in the stud pin P, the groove portion 23 may be continuous in an annular shape around the inner shell 22. In this case, the amount of edges at the inner peripheral end of the outer shell 21 and the outer peripheral end of the inner shell 22 can be maximized, the edge effect thereof can be enhanced, and the performance on ice can be effectively improved.

FIG. 5 shows a modified example of the stud pin. In FIG. 5, the tip portion 20 of the stud pin P includes a plurality of connecting portions 24 that connect the outer shell 21 and the inner shell 22 to each other. These connecting portions 24 are arranged so as to extend radially with respect to the central axis of the stud pin P. Further, in providing the connecting portion 24 between the outer shell 21 and the inner shell 22, it is preferable that the total length of the inner peripheral side of the groove portion 23 is 50% or more of the outer peripheral length of the inner shell 22. For example, in FIG. 5, the lengths of the four divided pieces of the groove portion 23 divided by the connecting portion 24 on the inner peripheral side are L1, L2, L3, L4, and the total sum thereof is La (La = L1 + L2 + L3 + L4). When the outer peripheral length of 22 (the outer peripheral length assuming that the connecting portion 24 does not exist) is Lb, it is preferable that La ≧ 0.5 × Lb. In this case, the strength of the stud pin P can be increased. Here, if the total length of the groove portion 23 on the inner peripheral side is less than 50% of the outer peripheral length of the inner shell 22, the effect of improving the performance on ice is reduced due to the decrease in the amount of edges.

6 to 8 show other modifications of the stud pin, respectively. In FIG. 6, the inner hull 22 has an inner groove portion 22C extending in an annular shape along the outer peripheral edge thereof, whereby the inner hull body 22A in which the inner hull 22 is located on the innermost side and the inner hull outer edge located on the outer peripheral side thereof. It is divided into parts 22B. By partitioning the inner shell 22 into the inner shell main body 22A and the inner shell outer edge portion 22B in this way, the amount of edges is further increased, so that the performance on ice can be effectively improved.

In FIGS. 7 and 8, the inner peripheral shape of the outer shell 21 and the outer peripheral shape of the inner shell 22 are different from each other. In FIG. 7, the inner peripheral shape of the outer shell 21 is circular, but the outer peripheral shape of the inner shell 22 is square. In FIG. 8, the inner peripheral shape of the outer shell 21 is circular, but the outer peripheral shape of the inner shell 22 is elliptical. By making the inner peripheral shape of the outer shell 21 and the outer peripheral shape of the inner shell 22 different from each other in this way, the snow-removing ice property of the tip portion 20 of the stud pin P is improved, and the on-ice performance is further improved by increasing the edge amount. can do.

The inner peripheral shape of the outer shell 21 and the outer peripheral shape of the inner shell 22 may be similar to each other (see FIG. 2). In this case as well, sufficient edge effect can be expected. The inner peripheral shape of the outer shell 21 and the outer peripheral shape of the inner shell 22 are not particularly limited, and various shapes such as a circular shape, an elliptical shape, and a polygonal shape including a quadrangle can be adopted.

As shown in FIG. 4, the distance Ly between the outer shell 21 and the inner shell 22 measured in the direction orthogonal to the central axis O of the stud pin P is the outer shell measured in the direction orthogonal to the central axis O of the stud pin P. The dimension Lx of 21 is preferably in the range of 10% to 35%, more preferably in the range of 15% to 30%. As a result, the strength of the stud pin P can be sufficiently ensured, and deterioration of snow-removal ice-removing property and workability can be avoided. Here, if the distance Ly between the outer shell 21 and the inner shell 22 is too small, the snow-removal ice-removing property and workability deteriorate, and conversely, if it is too large, the strength of the stud pin P decreases.

Further, for the inner shell main body 22A located on the innermost side of the inner shell 22, the dimension Lz of the inner shell main body 22A measured in the direction orthogonal to the central axis O of the stud pin P is orthogonal to the central axis O of the stud pin P. It is preferable that the dimension Lx of the outer shell 21 is measured in the range of 10% to 60%, more preferably 20% to 40%. As a result, the strength of the stud pin P can be sufficiently ensured, and deterioration of snow-removal ice-removing property and workability can be avoided. Here, if the dimension Lz of the inner shell main body 22A is too small, the strength of the stud pin P decreases, and conversely, if it is too large, the snow-removal ice-removing property and workability deteriorate.

The dimension Lx of the outer shell 21 measured in the direction orthogonal to the central axis O of the stud pin P is preferably set in the range of 2 mm to 4 mm. Further, the thickness t of the outer shell 21 measured in the direction orthogonal to the central axis O of the stud pin P is preferably set in the range of 0.3 mm to 0.6 mm. As a result, the strength of the stud pin P can be sufficiently ensured, and deterioration of snow-removal ice-removing property and workability can be avoided.

The above-mentioned dimension Lx of the outer shell 21, the distance Ly between the outer shell 21 and the inner shell 22, the dimension Lz of the inner shell main body 22A, and the thickness t of the outer shell 21 are the positions where the outer shell 21 and the inner shell 22 are separated by the groove portion 23. It is measured at an arbitrary position around the central axis O of the stud pin P. When the outer shell 21 or the inner shell 22 is chamfered, the dimensions are measured assuming that the chamfered portion does not exist.

FIG. 9 shows an example of the pneumatic tire of the present invention. As shown in FIG. 5, the pneumatic tire T includes a tread portion 31 extending in the tire circumferential direction to form an annular shape, a pair of sidewall portions 32, 32 arranged on both sides of the tread portion 31, and these. It includes a pair of bead portions 33, 33 arranged inside the sidewall portion 32 in the tire radial direction.

A carcass layer 4 is mounted between the pair of bead portions 33, 33. The carcass layer 34 includes a plurality of reinforcing cords extending in the radial direction of the tire, and is folded back from the inside to the outside of the tire around the bead core 35 arranged in each bead portion 33. A bead filler 36 made of a rubber composition having a triangular cross section is arranged on the outer periphery of the bead core 35.

On the other hand, a plurality of belt layers 37 are embedded on the outer peripheral side of the carcass layer 34 in the tread portion 31. These belt layers 37 include a plurality of reinforcing cords that are inclined with respect to the tire circumferential direction, and the reinforcing cords are arranged so as to intersect each other between the layers. In the belt layer 37, the inclination angle of the reinforcing cord with respect to the tire circumferential direction is set to, for example, in the range of 10 ° to 40 °. As the reinforcing cord of the belt layer 37, a steel cord is preferably used. At least one belt cover layer 38 having reinforcing cords arranged at an angle of, for example, 5 ° or less with respect to the tire circumferential direction is arranged on the outer peripheral side of the belt layer 37 for the purpose of improving high-speed durability. There is. As the reinforcing cord of the belt cover layer 38, an organic fiber cord such as nylon or aramid is preferably used.

In the pneumatic tire T, a main groove 41 extending in the tire circumferential direction is formed in the tread portion 31, and a plurality of land portions 42 are partitioned by these main grooves 41. A plurality of implantation holes 43 for implanting the stud pin P are formed in the land portion 42 of the tread portion 31. The stud pin P is arranged in the tread portion 31 so that the embedded base portion 10 is inserted into the implantation hole 43 and the tip portion 20 protrudes from the tread portion 31. The inner diameter of the implantation hole 43 is slightly smaller than the outer diameter of the stud pin P, and the stud pin P implanted in the implantation hole 43 is firmly held against the tread portion 31.

By disposing the stud pin P having a predetermined structure on the tread portion 31 of the pneumatic tire T as described above, it is possible to exhibit excellent on-ice performance based on the edge effect of the stud pin P.

The reinforcing structure of the pneumatic tire T shown in FIG. 9 shows a typical example, but is not limited thereto. Further, the tread pattern formed on the tread portion 31 of the pneumatic tire T is not particularly limited.

In the pneumatic tire having a tire size of 205 / 55R16 94T, the conventional tires and the tires of Examples 1 to 4 in which only the structure of the stud pin arranged in the tread portion is different were manufactured.

In the conventional example, a stud pin having a buried base portion and a tip portion and having a tip portion processed into a columnar shape was used. In Examples 1 to 4, a stud pin having a buried base portion and a tip portion, the tip portion having an annular outer shell, an inner shell surrounded by the outer shell, and a groove portion interposed between the two was used. For Examples 1 to 4, the presence or absence of the inner groove portion in the inner shell, the inner peripheral shape of the outer shell, and the outer peripheral shape of the inner shell were set as shown in Table 1.

The performance on ice of these test tires was evaluated by the following test method, and the results are also shown in Table 1.

Performance on ice:
Each test tire is attached to a wheel with a rim size of 16 x 6.5J and mounted on a front-wheel drive vehicle with a displacement of 1400cc. The air pressure is set to 250kPa, and the distance from a running state of 20km / h on ice to braking and stopping is measured. bottom. The evaluation result is shown by an index of 100 in the conventional example using the reciprocal of the measured value. The larger this index value is, the better the performance on ice is.

As can be seen from Table 1, in Examples 1 to 4, the tip of the stud pin has an annular outer shell, an inner shell surrounded by the annular outer shell, and a groove portion interposed between the two, so that the comparison with the conventional example is made. Was able to demonstrate excellent on-ice performance based on the improved edge effect of the stud pins.

10 Buried base 11 Body 12 Shank 13 Bottom 20 Tip 21 Outer 22 Inner 22A Inner body 22B Inner outer edge 22C Inner groove 23 Groove 24 Connection 31 Tread P Stud pin T Pneumatic tire

Claims (7)

It has a buried base embedded in the tread portion of the tire and a tip portion located on the tip end side of the buried base portion and in contact with the road surface, and the metal material constituting the tip portion is a metal constituting the buried base portion. In a stud pin that is harder than the material and in which the buried base and the tip are integrally processed , the tip is an outer shell formed in an annular shape, an inner shell surrounded by the outer shell, and the outer shell. A stud pin comprising a groove portion interposed between the inner shell and the groove portion, which is continuous in an annular shape around the inner shell . The stud pin according to claim 1 , wherein the inner shell has an inner groove portion extending along the outer peripheral edge thereof. The stud pin according to any one of claims 1 to 2 , wherein the inner peripheral shape of the outer shell and the outer peripheral shape of the inner shell are different from each other. The stud pin according to any one of claims 1 and 2 , wherein the inner peripheral shape of the outer shell and the outer peripheral shape of the inner shell are similar to each other. The distance Ly between the outer shell and the inner shell measured in the direction orthogonal to the stud pin central axis is in the range of 10% to 35% of the dimension Lx of the outer shell measured in the direction orthogonal to the stud pin central axis. The stud pin according to any one of claims 1 to 4 , wherein the stud pin is characterized by the above. Including the inner shell body in which the inner shell is located on the innermost side, the outer shell whose dimension Lz measured in the direction orthogonal to the stud pin central axis is measured in the direction orthogonal to the stud pin central axis. The stud pin according to any one of claims 1 to 5 , wherein the stud pin is in the range of 10% to 60% of the dimension Lx. A tire according to any one of claims 1 to 6 , wherein the stud pin is arranged on the tread portion.

Images