JP2942465B2 - Manufacturing method for pneumatic tires - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a pneumatic tire having a carcass straddling between two bead rings and a breaker disposed between the carcass and the tread rubber. Is characterized in that microwave energy is used for at least a part of the energy.

[0002]

2. Description of the Related Art A pneumatic tire is usually manufactured using a bead ring using a metal cord and, at least in the case of a radial tire, a metal breaker.

[0003] On the other hand, at the time of retreading (tread rehabilitation) of a tire, an unvulcanized bonding rubber layer between a vulcanized tread ring and a carcass is vulcanized by microwave energy, and the tread ring is permanently integrated. It is known that

In order to further reduce tire production time,
Attempts have been made to utilize microwave energy in the manufacture of tires made entirely of rubber.

[0005]

However, these have been attempted in specific tires and in specific cases, and the conventional attempts are only very limited.

An object of the present invention is to provide a method of manufacturing a pneumatic tire including a bead ring, a carcass, and a breaker by using microwave energy at least in part, as described above. The production method of the present invention, on the one hand, allows a reduction in the total weight without lowering the target tire characteristics, and, on the other hand, substantially improves the economics of such a tire production method. sell.

[0007]

SUMMARY OF THE INVENTION The present invention is a method of manufacturing a pneumatic tire having a carcass straddling between two bead rings and a breaker disposed between the carcass and the tread rubber. The tire raw cover is assembled using only non-metal members, and the tire raw cover is
Is at least partially microwave permeable and
Pressurized gold that can be heated by microwave energy
Attached to the mold and required during the pressing and heating process
At least a significant portion of the energy is microwave energy
A method for manufacturing a pneumatic tire, characterized by being provided by Lugie .

[0008]

By not using a metal member, not only can the weight be substantially reduced, but this also satisfies the prerequisite that microwave energy can be employed in the vulcanization process of the raw tire cover. This allows the total heating time to be substantially reduced, and, if desired, to reach an ideal state in which the heating time corresponds to the tire assembly time. This results in an increase in the number of tires produced per mold, i.e., the number of molds can be substantially reduced, and an increase in production can also save space at each factory.

[0009] The use of microwave energy and the resulting reaction between the rubber composition and other non-metallic tire components results in a good bond.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the method for manufacturing a pneumatic tire according to the present invention will be described below. Extend over the carcass between two bead rings, and Ru tire raw cover having a breaker arranged between the carcass and the tread rubber are assembled using only non-metal member.

[0011] pressure for the tire production cover assembled without using metals, provide a significant portion of the energy required during the heating step in the tire production covered by microwave energy.

For this purpose, a mold that is at least partially permeable to microwaves and that is itself heated by microwave energy is used as a pressure mold. When using such a pressing mold, the raw tire cover can be directly mounted on the pressing mold, and the raw tire cover, on the other hand, is directly heated by the microwave energy and more quickly to the intended temperature. Can be in a heated state, and on the other hand, energy is supplied from the outside by a pressurizing mold which itself is heated.

[0013] Even in the case where the raw tire cover is preheated by the microwave energy, the use of such a pressurizing mold is effective in transferring the raw tire cover from the preheating step to the pressurizing die in the area of the outer wall. The advantage is that the resulting heat losses are compensated particularly quickly and effectively.

Further, mounting the raw tire cover on the pressurized mold from the beginning requires the outer wall of the raw tire cover when transferring from the preheating step of preheating by microwave energy to the pressurized die. There is an advantage that heat loss in the region can be eliminated.

A mold using a synthetic material such as a synthetic resin,
It can be suitably used as a pressing mold. In addition, the pressurized mold may have a region where the microwave absorption value and / or the microwave transmission value are different. This adapts these regions, which behave differently with respect to microwave energy, to different regions of the raw tire cover, respectively, so that the tread region, sidewall region, and / or bead region have different thermal energy, respectively. It can be given.

The regions having different microwave absorption values and / or microwave transmission values of the pressurized mold can be formed by using a plurality of materials having different microwave absorption and / or microwave transmission. In addition, since different parts of the material of the pressing mold are matched with regions of tires having different configurations such as a bead part, a side wall part, and a tread part, different parts are preferably heated by applying different thermal energy. is there.

In addition, the above-mentioned region of the pressurized mold having different absorption and / or permeability properties is provided with one or more thin adjustment layers adapted to the wavelength of microwave energy used in the pressurized mold. It can also be formed by being attached to a pressing mold, and this adjustment layer can adjust the reflection and / or absorption behavior of the pressing mold. The pressure inside the pressurizing mold can be changed depending on the intensity of the microwave.

In yet another preferred embodiment, the pressing mold can comprise at least one metal inner surface or metal body that is directly used as a microwave container to which microwave energy is coupled in a conventional manner.

By arranging a pressurized mold as a direct microwave container and as a hollow microwave guiding cavity, the structure of the apparatus required for the method of the present invention can be simplified. This device can be configured as an annular microwave guide device having a plurality of coupling portions for coupling microwave energy supplied over the outer periphery.

Further, the container may be configured as a cavity resonance box to which an input / output waveguide for microwave transmission or a coaxial cylinder is connected and capable of transmitting microwaves. Coupling may include coupling by microwave resonance.

The intensity and wavelength of the microwaves can be varied with time during the supply to the raw tire cover, and can even be interrupted, a method which directly affects such a raw tire cover. By adopting this, it is possible to obtain an ideal vulcanized state for bonding of the non-metallic tire members.

Further, depending on the tire member used,
Microwaves of different frequencies at preset time intervals,
It may be generated at the same time during microwave heating to improve the bonding of the tire members.

Moving the tire with respect to the microwave source when one or more microwave sources are active, to equalize the supply of energy to the raw tire cover;
Preferably, it is rotated, and also the position and / or characteristics of the coupling of the microwave energy can be changed during the supply of the microwave energy, and further the energy distribution can be changed by means of optics for microwave reflection. Thus, it can be adapted to each tire shape. The optics can also be changed in position and / or orientation during the heating process.

In yet another aspect, a material having at least substantially neutral but increased microwave absorption properties can be used in predetermined regions of the raw tire cover. The material having excellent microwave absorption characteristics can be used in the region and / or on the surface of the region. At this time, even when the microwave itself does not have anisotropy, the degree of energy supply into the tire raw cover can be changed.

Further, such a material having good absorption efficiency of microwave energy into the raw tire cover can be employed as one or more kinds of mixture intended for use in a specific portion of the tire. Can be effectively adopted even inside the space.

The bead ring can use carbon fiber, aramid fiber, or their equivalent, and the breaker can employ aramid, nylon, rayon, or their equivalent. In addition, the tire member used for a normal tire can be adopted without being limited to the tire produced by the method of the present invention.

[0027]

As described above, according to the production method of the present invention, the metal member is not used for the raw tire cover,
Not only can the weight be reduced, but the total heating time can be substantially reduced by the use of microwave energy, and the number of tires produced per mold can be increased, and the number of molds can be reduced.

Continuation of the front page (51) Int.Cl. ⁶ Identification symbol FI B29K 105: 24 B29L 30:00 (56) References JP-A-57-137135 (JP, A) JP-A-57-137133 (JP, A) JP-A-56-51342 (JP, A) JP-A-56-150531 (JP, A) JP-A-48-49866 (JP, A) JP-A-58-24430 (JP, A) JP-A-4-185511 (JP, A) JP-A-5-212816 (JP, A) JP-A-5-301231 (JP, A) JP-A-59-75028 (JP, U) JP-B-52-2438 (JP, B2) ( 58) Field surveyed (Int.Cl. ⁶ , DB name) B29C 35/02-35/08 B29C 33/02-33/06 B29D 30/06 B60C 5/00

Claims (9)

(57) [Claims] 1. A carcass straddling between two bead rings,
And a method of manufacturing a pneumatic tire having a breaker disposed between the carcass and the tread rubber, wherein the raw tire cover is assembled using only non-metal members, and the raw tire cover is at least partially Microwave transmission
Transient and self-added by microwave energy
It is mounted on a pressurized mold that can be heated, and requires less energy during the pressurizing and heating steps.
At least a significant part is due to microwave energy
A method for manufacturing a pneumatic tire, the method being provided. 2. The method according to claim 1, wherein the pressing mold is made of a synthetic material.
The method for manufacturing a pneumatic tire according to claim 1, wherein: 3. The pressure mold has a microwave absorbing property, and
// Use multiple materials with different microwave transmission
As well as the parts that differ in the material of the pressing mold,
Characterized by different tire areas
The method for manufacturing a pneumatic tire according to claim 1 . 4. A pressurizing mold is used for microwave energy.
To form different absorbent and / or permeable areas
One or more adjustment layers are arranged.
The method for producing a pneumatic tire according to any one of claims 1 to 3 . 5. The method of claim 1, wherein the microwave energy is supplied
The intensity and wavelength change at least over time
The method for manufacturing a pneumatic tire according to any one of claims 1 to 4, wherein 6. The microwave energy is provided intermittently.
The pneumatic tire manufacturing method according to any one of claims 1 to 5, wherein the pneumatic tire is supplied . 7. The microwave energy, upon heating,
In a pre-selectable time interval,
7. A black wave is generated simultaneously.
The method for producing a pneumatic tire according to any one of the above. 8. The microwave energy is microwave energy.
Microwave energy is supplied while
Density distribution is determined by the properties of energy coupling and / or its distribution.
Depending on the position and / or the optical equipment, the shape of each tire
8. The method according to claim 1, wherein the shape is adapted.
A method for producing a pneumatic tire according to any one of the above. 9. The microwave guide device according to claim 1, wherein
Features a microwave reflector to make the distribution uniform
The method for manufacturing a pneumatic tire according to any one of claims 1 to 8 .