JP2001354008A - Precure tread for pretreading, and reclaimed pneumatic tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the generation of partial wear and the impairment of the appearance by increasing the frequency of cutting by the pitch division line of cutting areas when manufacturing a reclaimed pneumatic tire. SOLUTION: In this precure tread for pretreading in which patterns 2 are provided on a surface of a strip-like vulcanized rubber plate 1 at predetermined pitches along the longitudinal direction thereof, and both ends of the vulcanized rubber plate 1 in the longitudinal direction are formed into the cutting areas C, the patterns 2 of the cutting areas C are formed of a plurality of patterns 2c1, 2c2 and 2c3 of different pitches p1, p2 and p3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a precure tread for rehabilitation and a pneumatic rehabilitation tire using the same.
More particularly, the present invention relates to a retreaded precured tread that increases the frequency of cutting at a pitch demarcation line in a cutting area when manufacturing a pneumatic retreaded tire and a pneumatic retreaded tire using the same.

[0002]

2. Description of the Related Art In general, pneumatic tires for heavy loads such as buses and trucks, when the remaining groove of the tread reaches the end of its life,
The tread surface is cut and buffed, and the remaining tire body is used as a base tire, and a new tread is attached to it again, so that it can be reused as a retreaded tire.

As shown in FIG. 4, a tread used for such a retread tire has a pattern 2 at a constant pitch p along the longitudinal direction on the surface of a belt-shaped vulcanized rubber plate 21.
There is a precured tread for rehabilitation provided with 2. This precured tread is cut in the width direction in the longitudinal direction so as to have a length corresponding to the outer peripheral length of the base tire when the retreaded tire is manufactured, wound around the outer periphery of the base tire, and the cut end faces are butt-joined. A cutting area 23 for cutting several pitches at both ends in the longitudinal direction into a length corresponding to the outer peripheral length of the base tire. From the viewpoint of continuity of the pattern 22, such a precured tread is preferably cut at the pitch division line x of the cutting region 23.

However, a base tire having a tread surface cut and buffed has a length (the precured tread is defined by a pitch division line x) whose outer peripheral length is set according to the tire diameter, tread structure, and variations in buffing work. It is often not possible to cut to a length that allows cutting. As a result, the precured tread is cut at a position deviating from the pitch division line x of the cutting region 23, and as shown in FIG. 5, the pitch pa of the pattern 22a of one of the cutting regions where the cut end faces abut each other is set there. In addition, there is a problem in that uneven wear is easily generated at that portion, and in addition, the aesthetic appearance is impaired.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to increase the frequency of cutting at a pitch line in a cutting area when manufacturing a pneumatic retreaded tire, and to suppress the occurrence of uneven wear and impairment of appearance. And a pneumatic retread tire using the same.

[0006]

The precured tread for rehabilitation of the present invention, which achieves the above object, comprises a belt-shaped vulcanized rubber plate having a surface provided with a pattern at a predetermined pitch along a longitudinal direction thereof. Both ends in the longitudinal direction of the vulcanized rubber plate are cut regions for cutting the vulcanized rubber plate to a length corresponding to the outer peripheral length of the base tire, and the cut region is formed of a plurality of patterns having different pitches. It is characterized by.

Further, in the pneumatic retread tire of the present invention, the retreaded precured tread is cut in the cutting area corresponding to the outer peripheral length of the base tire, and the cut end face is wrapped around the base tire to abut the cut end faces. It is characterized by being joined.

[0008] By forming the cutting region from a plurality of patterns having different pitches, the precured tread cut by the pitch dividing line of the cutting region can be made to correspond to a longer length than before. In addition, it is possible to increase the frequency at which the tire can be cut at the pitch division line in the cutting area when the pneumatic retreaded tire is manufactured. Therefore, even if the outer peripheral length of the base tire is other than the set length, it is possible to cope with it.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 shows an example of a precured tread for rehabilitation according to the present invention. This precured tread Y for rehabilitation is formed on a surface of a belt-shaped vulcanized rubber plate 1 at a predetermined pitch along a longitudinal direction thereof. And a cutting area C for cutting the vulcanized rubber plate 1 by cutting several pitches (three pitches in the figure) at both ends in the longitudinal direction into a length corresponding to the outer peripheral length of the base tire.
It is.

A plurality of patterns 2 in both cutting regions C have a pattern 2a at a pitch pb in which the non-cutting regions A between both cutting regions C have the same length. consists pattern _{2c 1,} 2c 2, 2c ₃ having different pitches p _1, p _2, p ₃ respectively, it has become variable pitch. Note that x is a pitch dividing line that separates pitches. The order of the pitches p _1, p _{2, and} p ₃ is not particularly limited, and any one may be earlier and any later.

According to the present inventor, in the precure tread for rehabilitation, earnestly studying the improvement of the frequency at which cutting can be performed at the pitch demarcation line in the cutting area, the following has been found. That is, Precured tread 11R22.5 14P
In a buffed base tire using RTY287 (cut length set value 3200 mm, length of non-cut area A 3000 mm, length of both cut areas C 150 mm each), the distribution data of the outer peripheral length is obtained. Table 1 below shows the frequency of occurrence.

[0013]

[Table 1]

In contrast to the results shown in Table 1, in the conventional precured tread for rehabilitation, the pattern pitch of the two cut areas C is the same as that of the non-cut area A and has a length of 50 mm. Therefore, it has been found that the frequency of cutting at the pitch division line of the cutting region C corresponding to the outer peripheral length of the base tire is as low as 55% only when the outer peripheral length of the base tire is 3200 mm.

[0015] In the present invention, it was a pattern 2c _1, 2c _2, 2c ₃ of the cutting region C as described above to a variable pitch. For example, the precured tread of the size, 55 mm pitch p ₁ of the pattern 2c _1, 50 mm pitch p ₂ of the pattern 2c _2, when the pitch p ₃ of the pattern 2c ₃ to 45 mm, the pitch separation line between the cutting region C x
The length that can be obtained when cut with 3195mm
(A length 3000 mm + length of one cutting area C 150
mm + the other cutting area C length 45 mm), 3200 mm (A
3000 mm + length of one cutting area C 105 mm +
There are three types: the other cut area C has a length of 95 mm, and 3205 mm (the length of A is 3000 mm + the length of one cut area C is 55 mm + the length of the other cut area C is 150 mm). Therefore, the frequency of cutting at the pitch division line x of the cutting region C corresponding to the outer peripheral length of the base tire greatly increases to 85%, and the frequency of cutting at the pitch division line x with respect to the conventional precured tread is greatly increased. It can be enhanced. Therefore, it is possible to suppress occurrence of uneven wear and impairment of appearance. The same applies to precured treads of other sizes.

FIG. 2 shows the precured tread Y for rehabilitation.
1 shows an example of a pneumatic retreaded tire using a tire, D is a base tire, 11 is a tread portion, 12 is a sidewall portion, 13
Is a bead portion, and CL is a tire center line.

Inside the base tire D, a carcass layer 14 is mounted between a pair of left and right bead portions 13, 13, and both ends of the carcass layer 14 are arranged around a bead core 15 disposed in the bead portion 13.
The tire is folded from the inside to the outside of the tire so as to sandwich the bead filler 16. A belt layer 17 is provided on the outer peripheral side of the carcass layer 14 of the tread portion 11 of the base tire D, and a cutting area C corresponding to the outer peripheral length of the base tire D is provided on the outer peripheral side.
The precured tread Y for rehabilitation cut at the pitch division line x is wound and the cut end faces are butt-joined.

As shown in FIG. 3, on both sides of the joining portion S where the recured precured tread Y is cut at the pitch division line x of the cutting area C, wrapped around the outer periphery of the base tire T, and the cut end faces are butt-joined. As an example, pattern 2
Since c ₁ and 2c ₃ are continuous and the pitch of one of the portions is not shortened as in the related art, there is no problem of uneven wear and aesthetic appearance.

In the present invention, in the above embodiment, the patterns 2a of the non-cut area A are formed at the same pitch.
Instead, the pitch may be variable similarly to the cutting area C.

[0020]

As described above, according to the present invention, there is provided a precured tread for rehabilitation wherein a pattern is provided on a surface of a strip-shaped vulcanized rubber plate at a predetermined pitch along a longitudinal direction thereof. Both ends in the direction are cut areas for cutting the vulcanized rubber plate to a length corresponding to the outer peripheral length of the base tire, and the cut areas are formed by a plurality of patterns having different pitches. Occasionally, it is possible to increase the frequency of cutting at the pitch demarcation line of the cutting region, and suppress occurrence of uneven wear and impairment of the appearance.

[Brief description of the drawings]

FIG. 1 is a partially omitted plan view showing an example of a recured precured tread of the present invention.

FIG. 2 is a half-sectional view in the tire meridian direction showing an example of a pneumatic retreaded tire using the precure tread for retreading of the present invention.

FIG. 3 is an enlarged development view showing a joined portion of a retreaded precured tread in the pneumatic retreaded tire of FIG. 2;

FIG. 4 is a partially omitted plan view showing an example of a conventional recured precured tread.

FIG. 5 is an enlarged view of a main part showing an example in which the recured precured tread of FIG. 4 is cut and butt-joined at a section other than the pitch division line of the cutting area.

[Explanation of symbols]

1 vulcanized rubber plate _{2,2a, 2c 1, 2c 2,} 2c 3 pattern A non-cutting region C cutting region D stage tire Y retreading for precured tread _{pa, pb, p 1, p} 2, p 3 pitch x Pitch compartment line

Claims (2)

[Claims] 1. A recured precured tread in which a pattern is provided on a surface of a belt-shaped vulcanized rubber plate at a predetermined pitch along the longitudinal direction thereof, wherein both ends in the longitudinal direction of the vulcanized rubber plate are attached to a base tire. A precured tread for rehabilitation wherein a cut area for cutting the vulcanized rubber plate is formed to a length corresponding to an outer peripheral length, and the cut area is constituted by a plurality of patterns having different pitches. 2. The pneumatic pneumatic tire of claim 1, wherein the precured tread for rehabilitation is cut in the cutting area corresponding to the outer peripheral length of the base tire, wound around the base tire, and cut end faces are joined to each other. Rehabilitated tires.