JP5548556B2 - Pneumatic tire - Google Patents

Description

  The present invention relates to a pneumatic tire in which a plurality of spike pins each having a circular out-of-plane contour shape of a spike pin body are arranged on a tread ground surface, and particularly excellent in icy and snowy roads. The present invention proposes a technique for preventing the dropping of spike pins over a long period of time while ensuring driving, braking performance and skid resistance.

  Patent Document 1 discloses a pneumatic spike tire in which a plurality of spike pins each having a circular shape having the same diameter as a plane contour shape of a spike pin body are disposed on a tread ground surface. Stud pins of 50% or more of the total number of stud pins are formed so that the length in the tire circumferential direction of the protrusion at the tip is longer than the length in the tire width direction, and the range of 95% of the contact width The stud pin disposed in the range excluding the range of 65% or less of the contact width from the center in the tire width direction is formed so that the length in the tire circumferential direction of the protrusion is longer than the length in the tire width direction. According to this, “the edge effect in the width direction of the vehicle can be sufficiently obtained when traveling on a snowy icy road, so that the steering stability during turning can be improved. so And that. ".

JP 2008-284922 A

  The pneumatic spike tire described in Patent Document 1 has a planar contour shape of a tip protrusion protruding from the tip of a spike pin body having a columnar shape with the same diameter as a rectangle, etc. While the length in the tire circumferential direction of the tip protrusion is made longer than the length in the tire width direction, in other areas, the length in the tire width direction of the tip protrusion is made longer than the length in the tire circumferential direction. When the tire is new, it can exhibit excellent driving and braking performance and high skid resistance under the action of each spike pin, but the spike pin arranged on the tread central area side is large. Due to the input of the road surface reaction force to the driving force and braking force, it will fall off earlier than the spike pins arranged in other areas, and this will cause the tires to have a high driving force. There is a problem that continues to not be able to exert fine-braking performance over a long period of time.

  An object of the present invention is to solve such problems of the prior art, and the object of the invention is a spike disposed on the tread side edge side in the side area of the tread ground surface. An object of the present invention is to provide a pneumatic tire capable of preventing the falling of a spike pin disposed on the tread central region side for a long period of time while sufficiently ensuring the skid resistance by the pin for a long period of time.

The pneumatic tire according to the present invention is formed by arranging a plurality of spike pins having a circular out-of-plane contour shape of a spike pin body on a tread ground surface, and the tread ground width, that is, the width of the tread ground surface. In the tread width direction, and is divided into three equal parts in the central area and each side area, and in each side area, the center within the range of 1/6 to 1/12 of the tread grounding width from the central area side. The maximum body diameter of one or more spike pins arranged on the land side of the area is smaller than the maximum diameter of the body of the spike pins arranged on the remaining land part on the side of the tread side of each side area. It is.

Here, the “out-of-plane contour” of the spike pin body refers to the spike pin having a tip projection with a smaller dimension than the body at the tip of the columnar body, and the spike pin body to the tip projection. Instead, it may have a conical, pyramidal, spherical, or other depression, so as to eliminate the doubt of interpretation.
In addition, here, “the one or more rows of spike pins arranged in the central region side land portion” means that, when multiple rows of spike pins are arranged in the central region side land portion, at least one row of spike pins. This includes the case where the body dimensions satisfy the above requirements.

  In such a tire, preferably, the maximum diameter of the body of the spike pin disposed in the central region side land portion is in a range of 0.8 to 0.9 times the maximum diameter of the body of the spike pin disposed in the remaining land portion. And

Preferably, the diameter of the lower end flange of the spike pin is in the range of 1.1 to 1.5 times the maximum diameter of the spike pin body, which is a common diameter regardless of the diameter of the spike pin body. And
Here, the “maximum diameter” for the spike pin body is taken into consideration that the spike pin body may have a constricted portion with a small outer diameter.

  In the above description, the diameter of the lower end flange of the spike pin disposed in the central region side land portion is set to a range of 1.4 to 1.5 times the maximum diameter of the spike pin body, It is preferable that the diameter of the lower end flange of the arranged spike pin is in the range of 1.1 to 1.3 times the maximum diameter of the spike pin body.

  In the pneumatic tire of the present invention, the body diameter of the spike pin disposed in the land portion on the central region side of each side region is set to be smaller than the body diameter of the spike pin disposed in the remaining land portion on the tread side edge side. As a result, the road surface reaction force against the driving force and braking force generated by the spike pin on the land on the central region side when the tire is loaded and rolling is compared with the input to each spike pin compared to the conventional technology. As a result, the drop-out resistance of the spike pin can be effectively improved as compared with the conventional tire, and the driving and braking performance of the tire can be maintained sufficiently high for a long period of time.

  In addition, in this tire, the body diameter of the spike pin that is disposed on the remaining land portion of each side region and has a low risk of falling off is set to a dimension that can sufficiently secure the required high skid resistance, so that the ice and snow road etc. The excellent steering stability as expected can be achieved over a long period of time.

By the way, the maximum diameter of the body of the spike pin disposed in the central land side land portion of each side region is a range of 0.8 to 0.9 times the maximum diameter of the body of the spike pin disposed in the remaining land portion. In this case, the road surface reaction force input to each spike pin body in the central area side land portion is sufficiently suppressed while ensuring the required driving and braking, and the risk of the spike pin falling off can be effectively removed. it can.
That is, when the diameter ratio of the spike pin body is less than 0.8 times, there is a possibility that the driving force and the braking force with respect to the icy and snowy roads, etc. generated in the central region side land portion of each side region may be insufficient. If it exceeds .9 times, it may not be possible to prevent the spike pin from falling out as effectively as expected.

In many cases, if the diameter of the lower end flange of the spike pin, which is common to all spike pins, is 1.1 to 1.5 times the maximum diameter of the spike pin body, the spike With respect to the input of the road surface reaction force against the driving force and the braking force and the side slip resistance to the pin, the lower end flange can be held with a large force sufficient to resist the falling of the spike pin.
If the diameter of the lower end flange is less than 1.1 times, the holding force of the lower end flange may be too small compared to the input of the road surface reaction force to the spike pin body. If it exceeds twice, the lower end flange diameter becomes too large with respect to the predetermined lower hole diameter, and it becomes difficult to drive the spike pin. On the other hand, if the lower hole diameter is set according to the lower end flange diameter, the holding force of the spike pin by rubber is reduced. May decrease.

Also, here, when the diameter of the lower end flange of the spike pin arranged in the central area side land portion is set to 1.4 to 1.5 times the maximum diameter of the spike pin body, the spike pin is inserted by the lower end flange. Sufficient stability can be achieved, and the movement of the spike pin can be effectively suppressed with respect to driving and braking, so that the drop-out resistance of the spike pin can be further improved.
And when the diameter of the lower end flange of the spike pin arranged on the remaining land portion is in the range of 1.1 to 1.3 times the maximum diameter of the spike pin body, the spike pin should be sufficient by the body itself. The external force acting on the lower end flange can be advantageously relaxed.Therefore, there is an advantage that the steering stability can be improved by increasing the body diameter while the external force input to the lower end flange is limited. is there.

It is a partial expansion top view of a tread grounding surface showing an embodiment of this invention by one arrangement mode of a spike pin. It is a figure which illustrates the form of a spike pin. It is a figure similar to FIG. 1 which shows another embodiment. It is a tire side view which shows the arrangement | positioning area | region of the spike pin of an Example.

The pneumatic tire whose tread contact surface is shown in FIG. 1 may have the same internal structure as a conventional general radial tire or bias tire.
In this pneumatic tire, a plurality of spike pins having a circular planar contour shape of the spike pin body are arranged on the land portion of the tread contact surface.

  Here, the width of the tread ground contact surface, that is, the tread ground contact width W is divided into three equal parts in the tread width direction into the central region 1 and the respective side region 2, and each side region 2 The outside contour dimensions of the body 4a of the spike pin 4 embedded in the land portion 3 in the central region within the range of 1/6 to 1/12 of the tread grounding width from the region side, that is, the maximum diameter A is set on each side. The outside contour dimension of the body 6a of the spike pin 6 disposed in the remaining land portion 5 on the tread side edge side of the area 2 is also made smaller than the maximum diameter B.

Here, as shown in FIG. 2 (a), each spike pin 4 and 6 has a lower end flange 4b, a columnar body 4a, and a solid tip projection 4c, as shown in FIG. As shown in FIG. 2B, for example, the spike pin 4 can be provided with a constriction 4d in a region adjacent to the lower end flange 4b of the body 4a. Even in such a case, the tip protrusion or the spike body itself without the tip protrusion may be provided with a conical shape, a spherical shape or other depressions.
FIG. 2C shows a plan view of FIGS. 2A and 2B.
By the way, each spike pin 6 is obtained by increasing the out-of-plane contour diameter B of the spike pin body 6a as compared with that shown in FIG.

  When such spike pins 4 and 6 are arranged as shown in FIG. 1, the surfaces of the land portions 3 and 5 are at levels illustrated by phantom lines in FIGS. 2 (a) and 2 (b). These spike pins 4 and 6 act on the road surface at the peripheral edge of the projecting end of the spike pin bodies 4a and 6a from the land surface, together with the tip protrusions 4c and 6c, on the snowy road and the like. Will do.

  In the operation of the spike pins 4 and 6, the spike pin 4 disposed in the central region side land portion 3 has a small planar outline diameter A of the spike pin body 4 a. The input to each spike pin 4 of the road surface reaction force with respect to the generated driving force and braking force becomes relatively small. For this reason, the spike pin 4 can effectively prevent the accidental drop-out from the central region side land portion while sufficiently exhibiting the required driving and braking performance for the icy and snowy roads and the like.

  On the other hand, the spike pin 6 disposed on the remaining land portion 5 on the side edge side of each side region 2 having a low risk of unintentional dropout has a plane contour diameter B of the spike pin body 6a with a required side slip resistance. By making the diameter so large that it can be sufficiently exerted, it is possible to exhibit excellent handling stability over icy and snowy roads over a long period of time.

In the tire as described above, preferably, the maximum diameter A of the body 4a of the spike pin 4 disposed in the central land portion 3 is set to the maximum diameter B of the body 6a of the spike pin 6 disposed in the remaining land portion 5. Of 0.8 to 0.9 times.
Preferably, the diameters of the lower end flanges 4b and 6b, which are common dimensions of the spike pins 4 and 6, are in a range of 1.1 to 1.5 times the maximum diameters A and B of the spike pin bodies 4a and 6a. .

And preferably, the diameter of the lower end flange 4b of the spike pin 4 disposed in the central region side land portion 3 is set to a range of 1.4 to 1.5 times the maximum diameter A of the spike pin body 4a.
On the other hand, the diameter of the lower end flange 6b of the spike pin 6 disposed in the remaining land portion 5 is preferably in the range of 1.1 to 1.3 times the maximum diameter B of the spike pin body 6a.

FIG. 3 showing another reference example in a partially developed plan view of the tread ground plane is arranged with two rows of spike pins in the central region side land portion 3 of each side region 2, and among those spike pin rows The maximum diameter of the body 4a for each row of spike pins 4 in the central region is larger than the maximum diameter of the body 6a of the row of spike pins 6 arranged in the remaining land portion 5 on the side of the tread side of each side region 2. For the other one row of spike pins 7 on the tread side edge side disposed on the central region side land portion 3, the maximum diameter of the body 7a is set to the body of the spike pin 6 disposed on the remaining land portion 5. It is the same as the maximum diameter of 6a.

Also by this reference example, the central region side land portion 3 of each side region 2, a body diameter of studs 4 of one row of center-frequency side, the body diameter of the studs 6 of the remainder land portion 5 of the tread side edge By making it smaller, it is possible to effectively prevent the spike pin 4 from falling off and generate excellent driving and braking force over a long period of time.
In addition, in this tire, not only the spike pin 6 but also the spike pin 7 can contribute to the generation of a large skid drag, so that it is possible to further improve the steering stability performance on icy and snowy roads.

In addition, in the place shown in FIG. 3, the maximum diameters of the bodies 4a and 7a of all the spike pins 4 and 7 of the two spike pin rows arranged in the central region side land portion 3 are set together with the spikes of the remaining land portion 5. The maximum diameter of the body 6a of the pin 6 can also be made smaller. In this case, the maximum diameters of the bodies 4a and 7a of the respective spike pins 4 and 7 can be made the same or different from each other. .
1 and 3, the remaining land portion 5 is provided with one row of spike pin rows made of spike pins 6. However, if necessary, the remaining land portion 5 may have a plurality of spike pin rows. Can also be provided.

A performance test on ice is performed for each of the comparative tire and the example tire in which spike pins are arranged in various manners on the tread ground surface of a passenger car tire having a size of 195 / 65R15, and the spike pin drop-out resistance test is performed. Went.
The results are shown in Table 1 together with the specifications of each tire.
Here, the performance on ice is obtained by evaluating the handling stability performance, driving performance and braking performance when driving on the handling road of the in-house test course by a specialized test driver.
Further, the drop-out resistance of the spike pin is, as illustrated in FIG. 4, a region in which only the small-diameter spike pin is disposed on both the land portions 3 and 5 on the tread circumference (the same configuration as the tire 1 of the comparative example). ), A region where only the large-diameter spike pins are disposed on both the land portions 3 and 5 (same configuration as the comparative tire 2), and a small-diameter spike pin and a large-diameter spike on each of the land portions 3 and 5 The tire was divided into three equal parts in the region where the pins were arranged (same configuration as the tire of the example), and the number of spike pins dropped out from the three regions after running 30000 km was determined.
In Table 1, the index value with the comparative tire 1 as a control indicates a better result as it is larger.

According to the results shown in Table 1, it can be seen that the example tires can realize various excellent on-ice performances while ensuring the drop-out resistance of the spike pins.
In contrast, the comparative tire 2 can realize high performance on ice, but it is difficult to maintain the performance on ice for a long period of time due to early dropout of spike pins.

1 Central area 2 Side area 3 Central area side land 4, 6, 7 Spike pins 4a, 6a, 7a Body 4b, 6b Lower end flange 4c, 6c, 7c Tip protrusion 4d Constriction 5 Remaining land A, B Maximum diameter

Claims (3)

A pneumatic tire in which a plurality of spike pins having a circular out-of-plane contour shape of a spike pin body are arranged on a tread ground surface,
In the tread width direction, the tread ground contact width is divided into three equal parts into the central region and the respective side regions, and in each side region, a range of 1/6 to 1/12 of the tread ground contact width from the central region side the central region-side land portion studs of the maximum diameter of the body which is arranged in the inner, formed by smaller than the maximum diameter of each of the side region, the spike pin is disposed to the remainder land portion of the tread side edge body air Tires.   2. The maximum diameter of the body of the spike pin disposed in the central region side land portion is in a range of 0.8 to 0.9 times the maximum diameter of the body of the spike pin disposed in the remaining land portion. Pneumatic tires.   The pneumatic tire according to claim 1 or 2, wherein a diameter of a lower end flange of the spike pin is in a range of 1.1 to 1.5 times a maximum diameter of the spike pin body.