KR100253983B1 - Tyre cap tread - Google Patents

Abstract

PURPOSE: A tread for a tire having multilayered cap tread and its preparation method are provided, to allow the characteristics of ground contacting face of a tire to be changed into another one according to the abrasion extent. CONSTITUTION: The tread for a tire comprises cap treads, an under tread(4) and a wing strip(5), wherein the cap threads is composed of a laminate of cap tread layers(1,2) with different characteristics alternatively. The method comprises the steps of injecting a different characteristics of rubber compositions into the corresponding injection holes, wherein a plurality of rubber injection holes for cap treads are formed in the center part of a co-extruder; and co-extruding the compositions to form a multilayer structured cap tread.

Description

Tire tread with multi-layered cap tread and manufacturing method thereof

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tread of a tire, and more particularly, to a tread having a multi-layered cap tread in contact with a road surface so that one type of tire can be mounted and used in a vehicle regardless of season. will be.

Typically, the vehicle tire T is made of various semi-finished products made of rubber, steel wire, fabric, and the like, as shown in FIG. 1, for example, carcass, beads, sidewalls, treads, and the like. After joining together, it is produced by vulcanization.

Among them, the conventional tread was manufactured in the form shown in FIG. 2C by simultaneously extruding the cap tread, the wing strip and the under tread simultaneously in the coextruder 6 shown in FIGS. 2A and 2B.

However, the conventional tread has a drawback that the cap tread 3 is a single-layer structure, as shown in FIG. 2C, and thus is limited to the use area by being divided into four seasons, summer and winter tires from the time of manufacture until disposal. Therefore, when the season changed from autumn to winter, or from winter to spring, there was the inconvenience of having to replace the tires.

This was a financial burden on the consumer.

SUMMARY OF THE INVENTION The present invention has been made to improve the above disadvantages, and an object of the present invention is to provide a tread for a tire composed of a cap tread of a multi-layer structure by alternately co-extruding two kinds of rubber compositions having different characteristics.

In particular, the present invention has been made to improve the disadvantages of tire discomfort and economic burden, the upper layer using two rubbers of different properties during the extrusion of the cap tread forming part of the tread, If the lower layer is used for the summer rubber composition on the contrary, and the upper layer is applied to the summer rubber composition for the lower layer for the winter, it is characterized in that the tread shown in Figure 3c.

Therefore, in the tire with the tread of the present invention, when the cap tread layer of the upper layer (part of the road surface contacting) is worn out, the cap tread layer of the lower layer is naturally exposed, so that the characteristics of the tire are automatically switched seasonally without replacing the tire. There is a characteristic. Therefore, the inconvenience of having to replace tires seasonally can be reduced, and the economic burden can be reduced.

On the other hand, the important point in the present invention, the thickness of each layer of the cap tread forming a multi-layer structure, first by examining the average amount of wear of the cap tread for each season, and then determine the thickness of each layer of the cap tread.

In addition, if the average life of the tire is about 2 years, the number of the cap tread layers is applied twice, alternately for the summer and winter cap tread layers 1 and 2, as shown in FIG. 3c. It becomes the structure of the layer.

1 is a cross-sectional view of a pneumatic tire having a conventional single-layer cap tread,

2a is a front view of a conventional coextruder for tread extrusion,

2b is a left side view of a conventional coextruder for tread extrusion,

Figure 2c is a cross-sectional view of the tread manufactured in a conventional coextruder,

Figure 3a is a front view of the coextruder for tread extrusion according to the present invention,

3b is a left side view of the coextruder for tread extrusion according to the present invention;

Figure 3c is a cross-sectional view of the tread produced in the coextruder of the present invention.

* Explanation of symbols for main parts of the drawings

1: summer cap tread layer 2: winter cap tread layer

3, 3 ': cap tread 4: under tread

5: Heat strip 6, 7: Co-extruder

8: rubber inlet for cap tread 9a: rubber inlet for summer cap tread layer

9b: Winter cap tread layer rubber inlet 10, 10 ': Rubber strip for inlet strip

11: rubber trough for under tread 12, 12 ': tread

T: Tire

Hereinafter, with reference to the accompanying drawings, a tire tread having a multi-layered cap tread according to the present invention and a manufacturing method thereof will be described in detail.

First, a tread manufactured according to the present invention, a manufacturing method thereof, and a configuration of a coextruder proposed for manufacturing the tread will be described in comparison with the conventional one.

2a and 2b show a conventional coextruder for tread extrusion.

As referred to in the drawings, the rubber inlet for the cap tread (8) is formed in the center of the co-extruder (6), the rubber inlet (10, 10 ') for the wing strip is formed above the An undertread rubber inlet 11 is formed below the cap tread rubber inlet 8.

The rubber composition for the cap tread 3, the rubber composition for the under tread 4, and the rubber composition for the wing strip 5 are simultaneously introduced into each inlet of the conventional coextruder 6 configured as described above. By extruding it, it is produced by the tread 12 of the shape shown in FIG. 2C.

On the contrary, a plurality of cap tread layer rubber inlets 9a and 9b are disposed in the center of the coextruder 7 provided in the present invention.

In the present embodiment, the cap tread layer rubber inlets 9a and 9b are illustrated in the case of two, but may be more than that.

Therefore, when the tread 12 'is manufactured by the coextruder 7 according to the present invention, the cap tread 3' becomes a multilayer by the number of cap tread layer rubber inlets formed at the center of the coextruder.

As described above, the tire tread of the present invention having the cap tread of the multi-layer structure, according to the degree of wear of the portion in contact with the road surface-that is, a predetermined cap tread layer (summer cap tread layer) after a certain period of time (1 The captread layer (the winter captread layer) 2 of the new property which is completely different from) is exposed.

Therefore, even if the tire is not replaced in accordance with the change of the season, the winter tire is automatically converted to its characteristics for the summer tire to reduce the economic burden on the consumer, it is possible to reduce the inconvenience when replacing the tire.

Claims (2)

In the manufacturing method of the tread to co-extrude the rubber composition of different characteristics into the co-extruder having a plurality of rubber inlet, A plurality of cap tread layer rubber inlets 9a and 9b are provided at the central portion of the coextruder 7, and the cap tread layer rubber compositions having different properties are introduced into the rubber inlets 9a and 9b, respectively. 3 ') to form a multi-layered structure, the tire tread having a multi-layered cap tread. In the tread for tires consisting of a cap tread (3 '), an under tread (4), a wing strip (5), The cap tread (3 ') is a tire tread having a multi-layered cap tread, characterized in that the cap tread layer (1, 2) of different characteristics are configured to be alternately stacked.

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