JP2971937B2 - Bias tubeless tire for guide wheels of new transportation vehicles - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a bias tubeless tire for a guide wheel of a new transportation vehicle such as a subway or a monorail.

[Conventional technology]

Conventionally, bias tubeless tires used as guide wheel tires for new transportation vehicles such as subways and monorails are used at a high internal pressure in order to reduce deflection and sufficiently fulfill the role of guide wheels.

Therefore, the air filled in the tire permeates the inner liner outwardly, though gradually. The air passing through the inner liner and further passing through the carcass ply layer has a sharply reduced transmission speed in the tire crown portion where the rubber layer is thick.

On the other hand, the tires for guide wheels of new transportation vehicles have a long service distance (200,000 km or more) due to long intervals of periodic inspections and complicated replacement work.

Therefore, in the bias tubeless tire for guide wheels of this new transportation vehicle, air is transmitted uniformly in all directions where pressure is applied during long-term use,
In a crown portion of a tread having a thick rubber gauge, the permeation speed is sharply reduced, so that an air reservoir is formed by air transmitted through the interliner and the carcass ply layer.

Furthermore, due to the nature of the tires for guide wheels of new transportation vehicles, the contact area is about 1/4 of the crown width centering on the center of the crown, and the heat generation in this area, especially near the tread surface, is large. Become.

As a result, due to this heat, the air reservoir generated near the tread center expands and induces separation, so that the deflection amount of the guide wheel bias tubeless tires mounted on the left and right of the new traffic vehicle varies. However, there has been a problem that the straight traveling guidance and vibration resistance of the new traffic vehicle are reduced.

[Problems to be solved by the invention]

In view of the above facts, the present invention can suppress the occurrence of an air reservoir near the tread center portion, prevent the air reservoir from expanding, and prevent the occurrence of separation. It is an object to obtain a bias tubeless tire for a guide wheel.

[Means and actions for solving the problem]

The bias tubeless tire for guide wheels of a new traffic vehicle according to the present invention is characterized in that a small-diameter hole is formed in the vicinity of the drill center from the tread surface toward the tire radially inward.

Therefore, in the bias tubeless tire for guide wheels of a new traffic vehicle according to the present invention, when the air filled in the air filling portion passes through the inner liner and the carcass ply layer and reaches near the tread center portion, This air is discharged to the outside of the tire through the small diameter hole. For this reason,
It is possible to suppress the occurrence of an air reservoir at the tread center. Also, if an air pocket is generated in the tread center, before the air pool expands significantly due to the heat generated in the tread center,
Air is discharged to the outside of the tire through the small-diameter hole. Therefore, the expansion of the air reservoir can be prevented.

Therefore, occurrence of separation at the tread center can be prevented.

Further, since the amount of air passing through the inner liner is extremely small, the decrease in the internal pressure of the bias tubeless tire for guide wheels of a new traffic vehicle can be sufficiently compensated for by replenishing air at the time of periodic inspection.

In addition, the depth of the small-diameter hole is set to a depth that reaches the outermost carcass ply. In addition to suppressing the expansion, the expansion of the air reservoir can be prevented. Further, since the depth of the small diameter hole does not reach the inner side in the tire radial direction of the outermost carcass ply, it does not cause cracks or the like.

It is preferable that the depth of the small-diameter hole be equal to the depth of the outermost carcass ply reaching the breaker provided on the outer side in the tire radial direction of the carcass ply.

In addition, the diameter of the small-diameter hole is 0.2 mm to 5 mm, without impairing the appearance quality, preventing the small-diameter hole from absorbing moisture due to dew condensation, etc. The material can be prevented from deteriorating. Further, the small-diameter hole is not closed by the collapse of the tread or the suction of foreign substances such as abrasion rubber at the time of load. The hole diameter of the small hole is 0.5m
m to 2 mm is preferred.

The interval between the small-diameter holes is set to 10 mm to 150 mm, and is provided so as not to affect the deflection of the tire and to prevent the air from being greatly expanded even if an air reservoir is generated. The interval between the small diameter holes is preferably 30 mm to 70 mm.

(Example of the invention)

An embodiment of a bias tubeless tire for a guide wheel of a new traffic vehicle according to the present invention will be described with reference to FIG. 1 and FIG.

As shown in FIG. 1, on the center (tire equatorial plane) 14 of the tread 12 of the bias tubeless tire 10 for a guide wheel of a new traffic vehicle, the tire is radially inward at equal intervals in the tire circumferential direction. A vent hole 16 is formed as a small diameter hole. The vent hole 16 is formed by drilling a conventional product tire.

As shown in FIG. 2, two breakers 17 are disposed radially inward of the tread 12 of the bias tubeless tire 10 for guide wheels of a new traffic vehicle in the tire radial direction.
Six carcass plies 18 are arranged inside the breaker 17 in the tire radial direction. In addition, the air filling section 20 of the bias tubeless tire 10 for the guide wheels of a new traffic vehicle.
The inner liner 22 is provided in a portion adjacent to the inner liner.

As shown in FIG. 1, the vent holes 16 are formed at intervals of 10 mm to 150 mm in the tire circumferential direction, in a range that does not affect the bending of the tire, and, for example, even if an air accumulation portion occurs, The interval is such that the air in the air reservoir can be discharged before the air reservoir expands significantly.
Note that the interval between the vent holes 16 is preferably 30 mm to 70 mm (for example, a total of 45 vent holes 16 at the outer periphery of the tire at 50 mm).

The hole diameter of the vent hole 16 is set to 0.2 mm to 5 mm, without impairing the appearance quality, preventing the vent hole 16 from absorbing moisture due to dew condensation, etc., and the breaker 17 and the carcass ply 18 due to the moisture. The code material can be prevented from deteriorating. In addition, tread at the time of load
The vent hole 16 is not blocked by the collapse of 12 or the suction of foreign matter such as abrasion rubber. The tip of the vent hole 16 is formed in a conical shape in order to prevent it from interfering with the break 17 and the carcass ply 18 and causing damage.

The hole diameter of the vent hole 16 is preferably 0.5 mm to 2 mm (for example, a hole diameter of 2 mm).

As shown in FIG. 2, the depth of the vent hole 16 is set to a depth reaching the outermost layer 18A of the carcass ply 18, so that an air pocket outside the outermost layer 18A of the carcass ply 18 in the tire radial direction is generated. Penetrates the part that is easy to do. For this reason, it is possible to suppress the generation of the air pool and prevent the expansion of the air pool. Further, it penetrates through the carcass ply 18 so as not to cause a crack or the like.

The depth of the vent hole 16 is determined by the breaker 1 provided on the outer side of the outermost layer 18A of the carcass ply 18 in the tire radial direction.
A depth of 7 is preferred (eg, 11 mm deep).

 Next, the operation of the present embodiment will be described.

In the bias tubeless tire 10 for guide wheels of a new transportation vehicle of the present embodiment, when the filled air passes through the inner liner 22 and the outermost layer 18A of the carcass ply 18 and reaches the tread center portion, This air is discharged to the outside of the tire through the vent hole 16. For this reason, it is possible to suppress the occurrence of an air reservoir at the tread center. In addition, when an air reservoir is generated in the tread center portion, the air is discharged to the outside of the tire through the vent hole 16 before the air reservoir portion expands significantly due to the heat generated in the tread center portion. Therefore, the expansion of the air reservoir can be prevented.

Therefore, occurrence of separation at the tread center can be prevented.

Further, since the amount of air passing through the inner liner 22 is extremely small, a decrease in the internal pressure of the bias wheelless tire 10 for guide wheels of a new traffic vehicle can be sufficiently compensated for by replenishment of air at the time of periodic inspection.

In the present embodiment, the vent hole 16 is formed by using a hole, but the vent hole 16 may be formed as follows.

As shown in FIG. 3, the split mold 24 is provided with a vent hole forming portion 26, and the shape of the vent hole forming portion 26 is a columnar shape having a conical tip 26A. Therefore, the bias tubeless tire 10 for a guide wheel of a new transportation vehicle vulcanized by the split mold 24 has a vent hole (for example, a hole diameter of a vent hole).
1mm, venthole depth 11mm, venthole spacing 75m
m is formed around the tire circumference).

In the above embodiment, the vent hole 16 is provided at the center of the tread 12, but the vent hole 16 has a width of about 1/4 of the crown width around the center of the crown portion where the air reservoir easily expands due to heat generation. It may be provided within the range.

(Embodiment) Bias tubeless tire 10 for guide wheels of a new traffic vehicle of the embodiment shown in FIGS. 1 and 2 (tire size: LTS 6.00-16 12PR M, 6 carcass plies, 2 breakers) At a distance of 115 mm between vent holes 16
The tire of the present invention formed with a hole diameter of 2 mm and a depth of 11 mm (a total of 20 pieces on the outer periphery of the tire) and a conventional tire without a vent hole (tire size: LTS 6.00-16012PR M, 6 ply materials, 2 breakers) Were used to examine the relationship between the running distance and the area of the air reservoir.

As a result, as shown in FIG. 4, in the bias tubeless tire for guide wheels of a new traffic vehicle of the present invention,
It has been clarified that even when an air reservoir is generated, its expansion can be prevented, and the occurrence of separation can be prevented.

〔The invention's effect〕

Since the present invention is configured as described above, it is possible to suppress the occurrence of an air reservoir near the tread center portion, to prevent the air reservoir from expanding, and to prevent the occurrence of serration. Has an effect.

[Brief description of the drawings]

FIG. 1 is a partial plan view showing a tread surface of a bias tubeless tire for guide wheels of a new traffic vehicle according to an embodiment of the present invention, and FIG. 2 is a hatching showing an upper half of the tire along line 2-2 in FIG. FIG. 3 is a partially enlarged sectional view showing a split mold of a bias tubeless tire for a guide wheel of a new traffic vehicle according to an embodiment of the present invention, and FIG. It is a graph which shows the relationship between the travel distance of the bias tubeless tire for guide wheels of the new traffic vehicle and the conventional tire, and the area of the air reservoir. 10 Bias tireless tires for guide wheels of new transportation vehicles, 12 Treads, 14 Equatorial planes, 16 Bent holes, 18 Carcass plies, 18 A Outermost layer.

Claims (4)

(57) [Claims] 1. A bias tubeless tire for a guide wheel of a new traffic vehicle, wherein a small diameter hole is formed near a tread center portion from a tread surface toward a tire radially inward. 2. The bias tubeless tire for a guide wheel of a new traffic vehicle according to claim 1, wherein the depth of the small diameter hole is set to a depth reaching the outermost carcass ply. 3. The bias tubeless tire for a guide wheel of a new traffic vehicle according to claim 1, wherein said small diameter hole has a hole diameter of 0.2 mm to 5 mm. 4. The bias tubeless tire for a guide wheel of a new traffic vehicle according to claim 1, wherein an interval between the small diameter holes is 10 mm to 150 mm.