JP2016049626A - Retreaded tire production method and retreaded tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a retreaded tire production method for reducing a work time of vulcanization processing and improving productivity, by reducing a step number during vulcanization processing of the retreaded tire.SOLUTION: A retreaded tire production method is configured to perform vulcanization processing to a base tire with a precure tread which is formed by sticking the precure tread to a crown part of the base tire, thereby perform vulcanization bond of the precure tread to the base tire. The vulcanization processing is performed in a state that, one or plural bag-parts capable of filling gas or liquid therein are provided on an inner face side, and a belt-state or circular-state winding member covers at least the precure tread.SELECTED DRAWING: Figure 1

Description

  The present invention provides a precure tread to a base tire by vulcanizing a base tire with a precure tread formed by attaching a precure tread to the crown portion of the base tire via an unvulcanized cushion rubber. The present invention relates to a method for producing a retread tire that is vulcanized and bonded, and a retread tire.

  A pneumatic tire basically has a structure in which a tread in contact with a road surface is attached to a base tire. Since the tread wears as the tire runs for a long period of time, the service life is limited. However, with respect to the base tire, the tread can often be used sufficiently even after the end of its life. For this reason, the worn tread portion may be covered with a new tread and used again as a retread tire. Recycled tires are often used as tires for automobiles, particularly heavy duty tires for trucks or buses, in order to reduce tire costs. In the production of retreaded tires, there is a broad classification, and a tread pattern is already provided, as well as a remolding method in which an unvulcanized tread is attached to a base tire and a tread pattern is imparted to the tread while being vulcanized in a mold. The precured tread is affixed to the base tire to form a base tire with a precured tread, and this is attached to the rim body, and an annular vulcanization envelope is placed over the base tire with the precured tread. There are two types, a pre-curing method in which the inside of the envelope is evacuated, and the precure tread and the base tire are brought into close contact with each other and vulcanized in a vulcanizing can.

  Among the two types of methods described above, the precure method does not require a large-scale vulcanization mold like the remolding method, and has an advantage in the manufacturing method such that a plurality of vulcanization can be performed simultaneously with a simple apparatus. Moreover, the tires renewed by the precure method are formed by joining and integrating both members using vulcanized members for both the tread and the base tire. Compared to this, it is easy to obtain a uniform tire. For this reason, compared with a tire rehabilitated by the remolding method, there is an advantage that uneven wear hardly occurs, wear resistance is excellent, and durability is increased.

  As a manufacturing method of a retread tire by a precure method, in Patent Document 1 below, a tread pasting process for pasting a tread on a buffed base tire, and a film sticking for pasting a heat shrinkable film on the outer periphery of the tread pasted on the base tire The manufacturing method of the retread tire characterized by consisting of a process and the heat processing process which heat-processes is described.

JP 2006-281683 A

  However, in the precure tread method, it is necessary to deaerate the inside of the envelope covering the pedestal tire with the precure tread in order to ensure the adhesion between the precure tread and the pedestal tire during vulcanization. Since it takes a lot of man-hours and time, the actual situation is that it contributes to the deterioration of the productivity of retreaded tires.

  In addition, although the method of the said patent document 1 aims at improving the productivity of a retreaded tire by the efficient work method substituted for the work concerning an envelope, a heat-shrinkable film cannot be reused. However, there is still room for improvement from the viewpoint of improving productivity.

  The present invention has been made in view of the above circumstances, and by reducing the number of steps during the vulcanization treatment of the retreaded tire, a method for producing a retreaded tire that shortens the work time of the vulcanization treatment and improves the productivity. The purpose is to provide.

  The above object can be achieved by the following configuration. That is, the method for manufacturing a retread tire according to the present invention includes vulcanizing a pre-tyre tread base tire formed by attaching a pre-cured tread to the crown portion of the base tire via an unvulcanized cushion rubber. Is a retreaded tire manufacturing method in which the precure tread is vulcanized and bonded to the base tire, and is provided with one or more bag-shaped portions that can be filled with gas or liquid on the inner surface side. The vulcanization process is performed in a state where at least the precure tread is covered with a winding member.

  In the method of covering the annular vulcanization envelope from the base tire with the precure tread and degassing the inside of the envelope, it took a lot of time for degassing and there was a problem in terms of productivity. It is as follows. On the other hand, in the method for producing a retread tire according to the present invention, the vulcanization treatment is performed by covering at least the precure tread with a belt-like or annular winding member through a bag-like portion that can be filled with gas or liquid. At this time, the adhesion between the precure tread and the base tire can be easily ensured. For this reason, compared with the method using an envelope, the time required to ensure the adhesion between the precure tread and the base tire can be greatly shortened. As a result, the method for producing a retread tire according to the present invention has a reduced work time for the vulcanization treatment and is excellent in productivity.

  In the method for manufacturing a retread tire, it is preferable that at least the precure tread is covered with the winding member after the bag-like portion is filled with gas or liquid in advance. Or in the manufacturing method of the said retreaded tire, after covering the said precure tread with the said winding member at least, it is preferable to fill the bag-shaped part with gas or a liquid. In any method, the time required to secure the adhesion between the precure tread and the base tire can be greatly shortened as compared with the method using the envelope.

  The retreaded tire according to the present invention is manufactured by any one of the above manufacturing methods. Such retreaded tires are excellent in productivity.

The figure which showed an example of the winding member used for the manufacturing method of the retreaded tire which concerns on this invention The figure which showed an example of the state of the vulcanization process of the manufacturing method of the retreaded tire which concerns on this invention

  Hereinafter, an embodiment of a method for producing a retread tire according to the present invention will be described with reference to the drawings. Drawing 1 is a figure showing an example of the winding member used for the manufacturing method of the retreaded tire concerning the present invention.

  The winding member 1 used in the present embodiment has a configuration in which a bag-like portion 12 that can be filled with gas or liquid is provided on the inner surface side of a belt-like member 11. The band-shaped member 11 and the bag-shaped portion 12 are made of a material having durability and gas-impermeable or liquid-impermeable properties, for example, vulcanized rubber mainly composed of butyl rubber. The size of the belt-like member 11 and the bag-like portion 12 can be arbitrarily set according to the size of the precure tread (the pre-tyre tread-equipped tire 10) to be vulcanized. The width X can be 200 to 500 mm, and the length Y can be 3000 to 5000 mm. Further, the size and number of the bag-like portions 12 and the filling degree of gas or liquid (the filling degree of gas or liquid occupying the volume of the bag-like part in the bag) can be arbitrarily set.

  Examples of the gas that can be filled in the bag-like portion include air and nitrogen, and examples of the liquid include water.

  In the present embodiment, the example in which the bag-like portion 12 is provided on the inner surface side of the belt-like member 11 as the winding member 1 is shown. However, in the present invention, the bag-like portion is provided on the inner surface side of the annular member. It may be what was made. Even in this case, the size, material, and the like of the annular member can be arbitrarily designed in the same manner as the belt-like member.

  FIG. 2 is a view showing an example of a state of vulcanization treatment in the method for producing a retread tire according to the present invention. In the present embodiment, after filling the bag-like portion 12 with gas or liquid in advance, from the inner surface side of the winding member 1 (that is, from the bag-like portion 12 side), the unvulcanized cushion rubber 23 is placed on the base tire 21. An example of covering the stacked precure treads 22 is shown. As shown in FIG. 2, the winding member 1 is wound around the precure tread 22 while appropriately adjusting the filling degree of the gas or liquid in the bag-shaped portion 12 and is tightened with a belt or Velcro (registered trademark) or the like. Fix it. Thereby, the precure tread 22 can be pressed in the inner diameter direction while the bag-like portion 12 is recessed so as to follow the annular shape of the precure tread 22 during the vulcanization process. As a result, in the present embodiment, the adhesion between the precure tread 22 and the base tire 21 can be easily ensured during the vulcanization process.

  However, in the present invention, at least the precure tread is covered with the winding member, and then the bag-shaped portion is filled with gas or liquid, and during the vulcanization treatment, the adhesion between the precure tread and the base tire is improved. You may ensure simply. The method for fixing the winding member is the same as described above.

  In the method for manufacturing a retread tire according to the present invention, since the number of steps and the time required for the vulcanization treatment are greatly reduced, the manufactured retread tire is particularly advantageous in terms of cost.

  Hereinafter, the present invention will be described in more detail with reference to examples.

Comparative Example 1
A precure tread is affixed to a base tire to form a base tire with a precure tread, which is attached to a rim-like body, and an annular vulcanization envelope is placed over the base tire with a precure tread, and the envelope By degassing the inside, a base tire with a precure tread was covered with an envelope. The time required for this coating operation was defined as 100. Next, the retreaded tire (tire size 22.5 × 8.25) is obtained by performing vulcanization treatment by heating the tire with precure tread in a vulcanizing can at a vulcanization temperature of 120 ° C. for 2 hours. Manufactured.

Moreover, the durability of the retreaded tire obtained after vulcanization was evaluated by the following method.
[Tire durability test]
A test tire was assembled on a 22.5 × 8.25 wheel, the air pressure was adjusted to 900 kPa, a running test was performed on the drum under conditions of a speed of 40 km / h and a load of 3150 kg, and the running distance until failure was measured. . The evaluation is indexed with the travel distance of Comparative Example 1 being 100. If the numerical values are the same, it indicates that the tire has the same durability as a retread tire manufactured by an envelope method.

Example 1
As a winding member, a belt-like winding member (length: 4000 mm, width: 300 mm) provided with ten bag-like portions pre-filled with nitrogen is wound around a base tire with a precure tread and tightened. It was fixed using Velcro (registered trademark). The time required for fixing the winding member was measured using Comparative Example 1 as a reference (100). The results are shown in Table 1. Thereafter, retreaded tires were produced by the same method as in Comparative Example 1. The durability test results are shown in Table 1.

  From the results shown in Table 1, in the method for producing a retread tire according to Example 1, the productivity is remarkably increased without impairing the durability of the obtained retread tire as compared with the method for producing a retread tire according to Comparative Example 1. You can see that

Claims (4)

The precure tread is vulcanized to the base tire by vulcanizing the base tire with the precure tread formed by pasting the precure tread on the crown portion of the base tire through the unvulcanized cushion rubber. A method for manufacturing a retread tire to be bonded,
The vulcanization process is performed in a state where at least the precure tread is covered by a belt-like or annular winding member provided with one or more bag-like portions that can be filled with gas or liquid on the inner surface side. The manufacturing method of the retread tire characterized by the above-mentioned.   2. The method for manufacturing a retread tire according to claim 1, wherein at least the precure tread is covered with the winding member after the bag-like portion is filled with gas or liquid in advance.   2. The method for manufacturing a retread tire according to claim 1, wherein the bag-shaped portion is filled with a gas or a liquid after covering at least the precure tread with the winding member. A retread tire manufactured by the manufacturing method according to claim 1.

Images