JPH10315716A - Tire with rubbery projection - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a rubbery projection from softening even if a tire brings about heat and make the projection difficult to fall off by constituting a tire by two layers of a surface layer made of a low hardness material and a lower layer made of a high hardness material and providing a plurality of recessed parts in which lower layers of high hardness materials exist on an outer peripheral surface. SOLUTION: Recessed parts 3 are provided in a plurality of blocks 7 provided on the outer peripheral surface 2 of a tire 1 and the tire 1 is constituted by a two-layer formation of a surface layer 5 made of a low hardness material and a lower layer 6 made of a high hardness material under the surface layer 5. In the bottom parts 31 of the recessed parts 3, the base layers (the lower layers 6) of the tire 1 in which the low hardness materials are slightly interposed are formed. Further, pressing ascending part 61 are formed by the lower layers 6 in the bottom parts 31 of the recessed parts 3 and surround the base part 41 of a rubber projection 4, to further stabilize and hold the rubber projection 4. Core parts 62 of the blocks 7 are formed by the projected lower layers 6. Thus, rigidity of a pattern block is increased and an edge effect is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tire mounted on a vehicle, and more particularly to a tire having a rubber-like projection which is useful for running on icy and snowy road surfaces.

[0002]

2. Description of the Related Art Conventionally, spike tires made of metal have been used for vehicles running on icy and snowy roads. However, there is also a problem of shaving the road surface, and tires with rubber-like projections have appeared as one of the alternative tires. . Such a tire with rubbery projections
A recess is formed in the outer peripheral surface of the tire, and a non-slip device such as a rubber-like projection for exerting a spike function is fixed to the recess (Japanese Patent Application Laid-Open Nos. 8-118920 and 8-27).
No. 6710).

[0003]

However, in a tire with rubber-like projections, if the tires become hot while the vehicle is running, the rubber-like projections will not be able to bite into the road surface, and the spike performance will decrease. Was. The tire at the bottom of the concave portion supporting the rubber-like projections becomes softer as the temperature rises, and the rubber-like projections cannot be fixed firmly. In addition, the conventional rubber-like projection 8 attached to the concave portion has the structure shown in FIG.
In many cases, the tire T is in close contact with (or close to) the concave portion 9 as described above, and the heat of the tire T is easily transmitted to the rubber-like projections.

The present invention solves the above-mentioned problems, and even if the tire heats up while the automobile is running, firmly supports the rubber-like projections and prevents softening of the rubber-like projections. It is an object of the present invention to provide a tire with rubber-like projections in which the projections are hard to fall off.

[0005]

In order to achieve the above object,
The gist of the present invention according to claim 1 is a two-layer molding of a surface layer made of a low-hardness material and a lower layer made of a high-hardness material below the surface layer, and a thin layer according to the surface layer at a bottom portion. A tire provided with a plurality of recesses in which the lower layer of a high-hardness material is present on the outer peripheral surface, and a hard rubber-like protrusion fixed in the recesses. It is in. Here, "thin layer" refers to a layer having a thickness in the range of 0.2 mm to 5 mm. According to the second aspect of the present invention, there is provided a tire having a rubber-like projection according to the first aspect, wherein the rubber-like projection has a projection main body integrally formed on a base, and a diameter of the projection main body is made smaller than an inner diameter of the recess. Thus, a space is provided around the projection main body fixed in the recess.
According to a third aspect of the present invention, there is provided a tire with a rubber-like projection according to the first or second aspect, wherein a male shaft having a jaw at a bottom portion of the concave portion is erected integrally with the tire, while the rubber-like projection is formed. A female hole is provided on the bottom surface for fitting to the male shaft, and the male shaft is fitted into the female hole, whereby the rubber-like projection is fitted and fixed in the concave portion.

According to the first aspect of the present invention, a concave portion having a lower layer of a high-hardness material is provided at a bottom portion through a thin layer related to a surface layer, and a rubber-like projection is fixed in the concave portion. Firmly supports the rubber-like projections, so that even if heat is accumulated in the tire during traveling, the rubber-like projections are less likely to stick and exhibit spike performance. Further, since a low hardness material is used for the surface layer covering the lower layer, the grip force is not impaired, and the braking force is maintained. According to the second aspect of the present invention, when the diameter of the projection body is smaller than the inner diameter of the recess so that a space is provided around the projection body fixed in the recess, even when the vehicle travels on an icy and snowy road surface for a long time, the clearance is reduced. Since the snow water changes into the place and cools the rubber-like projections, the spike performance is continuously maintained. According to the third aspect of the present invention, by fitting the male shaft having the jaw into the female hole so that the rubber-like projection is fitted and fixed in the concave portion, the rubber-like projection is firmly fixed in the concave portion. As a result, the rubber-like projections can be more reliably prevented from falling off.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a tire with a rubber-like projection according to the present invention will be described in detail.

(1) Embodiment 1 FIGS. 1 to 4 show an embodiment of a tire with a rubber-like projection according to the present invention. FIG. 1 is a partial sectional view of the tire with a rubber-like projection, and FIG. FIG. 3 is a perspective view of a rubber-like protrusion, FIG. 3 is a temperature distribution diagram from a road contact portion to a bottom of a concave portion, and a cross-sectional view of the concave portion and the rubber-like protrusion. FIG. FIG.

In the tire with rubber-like projections, a plurality of blocks 7 provided on the outer peripheral surface 2 of the tire 1 are provided with a concave portion 3 and a hard rubber-like protrusion 4 is fixed in the concave portion. For example, a tread pattern as shown in FIG. 4 is adopted for the tire 1, but a plurality of blocks 7 in a center portion C through which the tire equator S passes are provided with a cylindrical concave portion 3. The tire 1 is formed by two-layer molding of a surface layer 5 made of a low-hardness material and a lower layer 6 made of a high-hardness material below the surface layer 5. The low-hardness material refers to a rubber material (for example, styrene / butadiene rubber, butadiene rubber, natural rubber, etc.) which has been conventionally used for tire treads on snow and ice, with an emphasis on gripping on the ground. On the other hand, a high-hardness material refers to a material that is harder than the low-hardness material, and more preferably a material having a hardness that can prevent the rubber-like projections 4 from sticking (for example, a filler or the like is added to the low-hardness material). And cured rubber).

Specifically, the hardness HS of the low hardness material (surface layer)
The range is from 50 ° to 60 ° at room temperature (20 ° C.) and 0 °
55 ° to 65 ° C. On the other hand, the hardness HS range of the high-hardness material (lower layer) is 60 ° to 75 ° at room temperature and 0 ° C.
67-77 °. If the hardness Hs of the high-hardness material used for the lower layer 6 is smaller than the above range, it is difficult to suppress the stickiness of the rubber-like projections 4. On the other hand, if it exceeds this range, it may hinder the two-layer molding. Because it becomes. More preferably, the hardness HS of the surface layer 5 is 53 °-
57 ゜ (at 20 ℃ C) and 55 ゜ -62 ゜ (at 0 ℃ C)
The hardness HS of the lower layer 6 is 65 °-
68 ゜ (at 20 ℃ C) and 67 ゜ -70 ゜ (at 0 ℃ C)
belongs to. This embodiment also employs this. The hardness is determined by a method of indicating a spring hardness (symbol HS) specified in JIS K6301. Although not shown, a carcass cord or belt (not shown) is integrated with the tire 1, and the hardness of the surface layer 5 or the lower layer 6 used here is represented by the hardness of the rubber itself excluding these.

Then, a base layer (lower layer 6) of the tire 1 in which a slightly low-hardness material (specifically, a thickness in the range of 0.2 mm to 5 mm) intervenes is formed in the bottom portion 31 of the concave portion 3.
In the present embodiment, as shown in FIG.
The rising portion 61 is formed by the lower layer 6 and surrounds the base 41 of the rubber-like projection. This is for keeping the rubber-like projections 4 more stable. In addition, the core 62 of the block 7 is formed by the raised lower layer 6. By forming the core 62 of the block 7 with the lower layer 6 made of a hard material, the rigidity of the pattern block is increased, and the edge effect is enhanced. The surface layer 5 is a rubber portion covering the lower layer 6 with a predetermined thickness, and forms a tire design surface E such as a block 7 of a tread pattern, a large groove around the block, and a sipe 8. Surface layer 5 forming tire design surface E such as block 7
The reason why a material having a low hardness is adopted is that a soft material is excellent in following up a minute road surface unevenness and is excellent in surface grip force.

The recess 3 is a columnar recess provided on the block surface. The concave portion 3 has an inner diameter d substantially corresponding to the outer diameter D ₁ of the base 41 of the rubber-like projection 4 fixed in the concave portion, and a depth h substantially equal to the height H of the rubber-like projection 4. I have. Here, the height H of the rubber-like projection is set to about 10 mm, and the depth h of the recess is made slightly shallower than this (FIG. 3).
With such a configuration, the initial performance of a new tire can be improved. The inner diameter d of the recess 3 and the outer diameter D ₁ of the base 41 are 6 mmφ.
And a diameter D ₂ of the protrusion main body 42 of the rubber-like protrusion 4.
Is set in the range of 4 mmφ to 8 mmφ.

The rubber-like projection 4 is a hard rubber molded product (for example, polynorbornene or the like). The shape is a pin-like body obtained by integrally molding a substantially cylindrical projection main body 42 having a small diameter on a base 41 serving as a pedestal as shown in FIG. A taper 421 is attached to the upper half portion of the projection main body 42. Here, the hardness of the rubber-like projections 4 is set to 70 ° to 95 ° (at an ambient temperature of 20 ° C.). Therefore, when the vehicle runs on a normal asphalt road surface, the block surface 71 does not damage the road surface because the block surface 71 comes into contact with the road surface R. on the other hand,
When traveling on icy and snowy roads, the surface layer 5 made of a low-hardness material
Compressive deformation under the pressure from (A chain line in FIG. 3). Therefore, the protrusion main body 42 related to the rubber-like protrusion 4 relatively protrudes from the concave portion 3, so that the protrusion main body 42 bites into the road surface R to perform a spike action.

The rubber-like projections 4 are bonded and fixed to the concave bottom surface 3a. As the adhesive, a cyanoacrylate type adhesive is used. When the rubber-like projection 4 is fixed in the recess 3, an annular space O is provided around the projection main body fixed in the recess. The space O preferably has a width W in the range of 1 mm to 3 mm. When traveling on an icy and snowy road surface, if there is a space width W in the above range, snow water enters the space and the projection body 4
Cool 2 Therefore, the projection main body 42 exhibits a spike performance of maintaining a predetermined hardness and biting into the road surface. Clearance width W
Is less than 1 mm, the replacement of snow water becomes difficult, and
2 becomes difficult to maintain a predetermined hardness. Clearance width W
Is less than 1 mm, the infiltrated snow water also stays in the empty space width W provided, and the cooling function does not work. On the other hand, if the space width W exceeds 3 mm, the area occupied by the projection main body 42 with respect to the area of the concave portion becomes too small, and the spike performance decreases.

Incidentally, as described above, the rubber-like projections 4 are fixed in the concave portions 3 provided in the block 7 of the center portion C. This is because the center portion C is a place where it is easy to contact the ground, and is a zone where a spike effect is always required. On the other hand, in the case where the shoulder portion B is in contact with the ground, it is when the vehicle is in an unstable state, and high grip performance is required. For these reasons, in the shoulder portion B, the surface layer 5 of a soft and low-hardness material having an excellent gripping function functions together with the spike effect of the rubber-like projections 4 on both sides of the tread. In this embodiment, six rubber-like projections 4 are arranged at one pitch, and a total of 96 rubber-like projections 4 are provided (tire size is 2.75-14). Of course, other tire sizes, 2.25-17, 2.50-17, 3.00-10
It can also be applied to

Since the rubber-like projections 4 are supported by the lower layer 6 made of a high-hardness material, the tire with the rubber-like projections configured as described above can sufficiently exhibit spike performance without sticking. Since the lower layer 6 is made of a high-hardness material, it hardly softens even when the temperature rises, and the rubber-like projections 4 maintain a stable state. Furthermore, in the present embodiment, the rising portion 61 of the high-hardness material surrounds the periphery of the base of the rubber-like projection 4.
The rubber-like projections 4 are more stably held on the lower layer 6. On the other hand, since the surface layer 5 made of a low-hardness material is formed on the lower layer 6 made of a high-hardness material, it is possible to maintain the softness of the studless and grip firmly on the road surface while exhibiting spike performance. it can. Since the pattern block as shown in FIG. 4 is formed, surface grip, edge traction, sipe traction, and the like can be operated to increase the force of gripping the road surface even on an icy and snowy road surface. In addition, since the core 62 of the block 7 is formed by raising the lower layer 6 made of a high-hardness material, the rigidity is increased as compared with the conventional product, and the edge traction performance of the block is improved. Further, the formation of the void O facilitates the replacement of snow water there, and even if the tire temperature rises, the rubber-like projections 4 can be maintained at a low temperature. Therefore, the spike performance of the rubber-like projection 4 is effectively exhibited. FIG. 3 shows the temperature change of the rubber-like projections 4 under the snowy road surface in correspondence with the cross-sectional view around the rubber-like projections 4. It has been confirmed that the temperature of the rubber-like projections up to the upper surface is almost equal to the temperature of snow water, and the spike performance does not decrease.

(2) Embodiment 2 In this embodiment, as shown in FIG. 5, a male shaft 63 is erected on the bottom portion 31 of the concave portion 3, and a female hole 43 fitted to the male shaft 63 is provided on the bottom surface. A rubber-like projection 4 is prepared, and a female hole 4 is
3 is fitted to fix the rubber-like projection 4 in the recess 3. Of course, instead of such a configuration, a male shaft may be provided at the bottom of the rubber-like projection 4 and a female hole fitted to the male shaft may be provided at the bottom portion 31 of the concave portion 3. A jaw 64 is formed on the upper part of the male shaft 63, and when the rubber-like projection 4 is fitted and fixed in the recess 3, the jaw 64 exerts a return function and is in a fitted state. Since the rubber-like projection 4 is a hard molded product and the male shaft 63 is formed by using the high-hardness material of the lower layer 6 as a core material, even if there is a temperature rise, both do not become soft, When both are fitted, it becomes difficult to remove. Of course, the rubber-like projections 4 may be fitted and fixed in the recesses in combination with the adhesive. Here, the height of the rubber-like projection fixed in the recess is made equal to the depth of the recess, and the upper surface of the rubber-like projection 4 is made to coincide with the level of the block surface 71. Other configurations are the same as in the first embodiment, and a description thereof will be omitted.

The rubber-like projection-equipped tire is provided with the rubber-like projection 4 by fitting the male shaft 63 and the female hole 43.
Is firmly fitted and fixed to the tire 1, so that the rubber-like projections 4 are less likely to fall off the tire due to impact, vibration, and the like during vehicle running than in the first embodiment. Other operations and effects are almost the same as those of the first embodiment.

(3) Embodiment 3 In this embodiment, as shown in FIG. 6, when the rubber-like projections 4 are arranged in the recesses 3, the small projections 65 protrude from the upper surface of the base 41. The small projection 65 functions as a stopper for locking the rubber-like projection 4. In FIG. 6, the projection main body 42 is a truncated cone. Other configurations are the same as in the first embodiment,
The description is omitted. In the tire with the rubber protrusions configured as described above, when the rubber protrusions 4 are fitted and fixed in the recesses 3, the rubber protrusions 4 are less likely to fall off the tire 1 by the stopper action of the small protrusions 65. Other operations and effects are almost the same as those of the first embodiment.

In the present invention, the present invention is not limited to those shown in the above embodiments, but can be variously changed within the scope of the present invention depending on the purpose and application. The shape, size, material, and the like of the tire 1, the concave portion 3, the rubber-like protrusion 4, the surface layer 5, the lower layer 6, the block 7, and the like can be appropriately selected according to the application.

[0019]

As described above, the tire with the rubber-like projections according to the present invention stably holds the rubber-like projections and suppresses the temperature rise of the rubber-like projections so that the spike performance can be fully exhibited. It is extremely advantageous that quality can be maintained by making the projections hard to fall off.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of a tire with a rubber-like projection according to a first embodiment.

FIG. 2 is a perspective view of a rubber-like projection used in FIG.

FIG. 3 is a cross-sectional view around a concave portion and a rubber-like protrusion to which a temperature change graph from a road contact portion to a concave bottom is added.

FIG. 4 is a partially developed plan view of a tread pattern of the tire with a rubber-like projection of FIG. 1;

FIG. 5 is a partial cross-sectional view of a tire with a rubber-like projection according to a second embodiment.

FIG. 6 is a partial cross-sectional view of a tire with a rubber-like projection according to a third embodiment.

FIG. 7 is an explanatory sectional view of a conventional technique.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 tire 2 outer peripheral surface 3 concave portion 31 bottom portion 4 rubber-like projection 41 base 42 projection body 43 female hole 5 surface layer 6 lower layer 63 male shaft 64 jaw d inner diameter of recess D2 diameter of projection body O void

Claims (3)

[Claims] 1. A high-hardness material comprising a two-layer molding of a surface layer made of a low-hardness material and a lower layer made of a high-hardness material below the surface layer, and a thin layer related to the surface layer at the bottom portion. A tire having rubber-like projections, comprising: a tire having a plurality of recesses in which the lower layer is present on an outer peripheral surface; and a hard rubber-like projection fixed in the recesses. 2. The rubber-like projection is formed such that a projection main body is integrally formed on a base portion, the diameter of the projection main body is made smaller than the inner diameter of the recess, and a space is provided around the projection main body fixed in the recess. The tire with rubber-like projections according to claim 1. 3. A male shaft having a jaw at the bottom of the recess is integrally formed with the tire, and a female hole is provided on the bottom surface of the rubber-like projection to fit the male shaft. The tire with a rubber-like projection according to claim 1 or 2, wherein the rubber-like projection is fitted and fixed in the concave portion by fitting a male shaft into the tire.