JP2955186B2 - Tire manufacturing method and vulcanizing and molding dies used therefor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention can reduce the manufacturing cost of molds by allowing a plurality of types of tires of the same size having partially different tread patterns to be vulcanized and molded with a single basic mold. The present invention relates to a method for manufacturing a tire, which can greatly reduce a tuning period in a development stage, and a vulcanizing and molding die used for the method.

[0002]

2. Description of the Related Art A plurality of types of tires having different tread patterns depending on applications and road conditions in each country must be prepared, even if the tire size is the same.

For example, in the United States, France, and the like, roads are provided with grooves that are continuous in the direction of travel in order to prevent slippage in rainy weather, thereby increasing the amount of drainage to prevent accidents. In addition, the gap between the two cities is 25 mm in Paris, France, and 19 mm in Los Angeles, USA.

When the vehicle travels on a road having such a groove, the groove interferes with the circumferential groove of the tire, and as a result,
There is a risk of wandering in the vehicle and an accident. Therefore, in order to prevent the wandering from occurring, it is necessary to adopt a groove width and groove arrangement of the circumferential grooves which do not interfere with the groove interval of the road surface on the tire side.

[0005]

However, the groove spacing is 19
It is extremely difficult to form the pattern corresponding to mm and the pattern corresponding to 25 mm in the same pattern. Conventionally, tires having patterns that match the road conditions have been manufactured individually. Therefore, there is a problem that the number of types of dies increases and production efficiency is poor.

On the other hand, at the stage of developing a new tire, it is necessary to balance the noise and the wettability as the performance required for the tire, and a tread pattern is locally applied several times before completion. The mold had to be newly manufactured each time. For this reason, there has been a problem that development is prolonged and costs are increased.

The present invention relates to a tire of the same size,
The ability to vulcanize and mold multiple types with different tread patterns using a single basic die can reduce die manufacturing costs, reduce costs, and increase the tuning period during tire development. It is an object of the present invention to provide a method of manufacturing a tire capable of achieving a great reduction in length and a mold for vulcanization and molding used in the method.

[0008]

SUMMARY OF THE INVENTION The present invention provides a pneumatic tire having a main groove including a circumferential groove extending in a circumferential direction in a tread portion by vulcanizing and forming a green tire mounted in a toroidal hole for forming. A mold for vulcanization and vulcanization, wherein a recess extending in a circumferential direction around a tire axis is formed on a tread molding surface of the toroidal hole for forming a tread surface of the pneumatic tire. And an embedding member having a molding surface which can be removably attached to the recess and which forms a portion of the recess on the tread surface of the pneumatic tire. Vulcanization and molding using a mold for vulcanization and molding formed by combining a plurality of ring pieces divided in the tire axial direction by a split surface passing through a circumferential groove of the portion, and vulcanizing and molding using the mold. Manufacture of tires characterized by that It is a method.

[0009] The filling metal can be provided between the adjacent ring pieces with a locking means which can be relatively rotated about the tire axis and can be locked to each other.

[0010]

With the above structure, even if the tread pattern of the pneumatic tire has a circumferential groove or a local tread pattern change, the mold body can be used as it is. By changing only the ring piece that forms the changed part of the embedded metallurgy, it is possible to respond to the change, even if it is a local tread pattern change, compared to the conventional manufacturing method that newly made the entire mold, The types of molds are reduced, and the management of the molds becomes easier.

Further, by manufacturing a pneumatic tire using the mold, the burden on the mold cost of the tire is reduced, and the tire can be economically provided.

In addition, at the stage of developing a new tire, it is sufficient to replace only the ring pieces corresponding to the changed portion at the time of local change and correction of the tread pattern. Can respond quickly to
The tuning period in the development stage can be greatly reduced.

[0013]

An embodiment of the present invention will be described below with reference to the drawings. Pneumatic tire 10 manufactured using the mold of the present example
As shown in FIG. 3, a tread portion 12 having an outer peripheral surface forming a tread surface 11, and a pair of sidewall portions 13, 1 extending from both ends of the tread portion 12 inward in the tire radial direction.
3 and a bead portion 14 connected to the inside of the sidewall portion 13 in the radial direction.

The pneumatic tire 10 has a tread 12
The carcass 16 and the tread portion 1 are turned around from the bead core 15 of the bead portion 14 through the side wall portion 13 to the bead portion 14.
2 and a belt layer 17 disposed outside the carcass 16 in the tire radial direction.

The pneumatic tire 10 is formed by vulcanizing and molding an unvulcanized or semi-vulcanized green tire 10A using a vulcanizing and molding die 1.

The raw tire 10A is in an unvulcanized or semi-vulcanized state in which the reinforcing members such as the rubber material and the carcass of the above-described parts are combined and bonded in a substantially tire shape.

In the present embodiment, the tread surface 11 is provided with a central circumferential groove 19A orbiting on the tire equator C, and between the circumferential groove 19A and the tread edges E on both sides. A circumferential groove 19 composed of the pair of circumferential grooves 19B, 19B is provided. Note that the circumferential grooves need not always be located on the tire equator.

In the present embodiment, the central and side circumferential grooves 1
9A and 19B, the two-way groove 19
A, the lateral groove 22A which connects 19B is the circumferential groove 1 on the other side.
An outer lateral groove 22 connecting the circumferential groove 19B and the tread edge E to the outer rib 21B between the tread edge E and the outer rib 21B between the tread edge E and the outer rib 21B.
B are provided respectively, and the inner and outer lateral grooves 22A,
2B form the lateral grooves 22. These lateral grooves 22 ...
Are arranged in a direction inclined with respect to the tire meridian plane. Further, in this example, the circumferential grooves 19 and the lateral grooves 22 are provided.
… Form the main groove 20.

A mold 1 for vulcanization and molding (hereinafter referred to as mold 1) includes a mold body 2 having a toroidal hole 3 for molding the pneumatic tire 10. In the present embodiment, the mold body 2 is provided with the raw tire 1 loaded in the toroidal hole 3.
The tire 0C is divided into two mold pieces 2A and 2B with the equatorial C plane of the tire 0A as the abutment surface 24. The two mold pieces 2A, 2B can be joined and separated by opening and closing the movable part L by being fixed to the fixing part F, respectively, and the toroidal hole 3 is formed by the joining.

In the toroidal hole 3, a recess 5 is formed parallel to the tread forming surface 4 of the pneumatic tire 10 and makes a round around the tire axis X in the circumferential direction.

The recess 5 is formed substantially symmetrically with the abutment surface 24 as a center, and has a substantially rectangular cross section which opens toward the toroidal hole 3.

A metal fitting 6 is embedded in the recess 5.
In the present example, the embedded metal object 6 is divided into two parts by a division surface 25 substantially flush with the abutment surface 24 of the mold body 2.
One embedding fitting 6A embedded in one mold piece 2A,
And the other metal fitting 6B embedded in the other mold piece 2B.

Each of these metal fittings 6A and 6B is formed by a plurality of ring pieces 9 divided by split surfaces 8 passing through the circumferential groove 19.

In this embodiment, as shown in FIG. 2, the split surface 8 has a groove edge H at which a groove wall 32 rising from the groove bottom 31 of the circumferential groove 19 toward the tread surface 11 intersects the tread surface 11. And at right angles to the tire axis X, the split surfaces 8, 8 are respectively formed at both groove edges H, H of the circumferential groove 18.

Accordingly, one mold piece 2A is formed with a central groove ring piece 9A, which forms half of the central circumferential groove 19A.
An inner rib ring piece 9B forming the inner rib 21A, a groove groove piece 9C on the side forming the side circumferential groove 19B, and two outer rib ring pieces 9D forming the outer rib 21B; 9E is formed by an aggregate of ring pieces 9.

The other mold piece 2B is connected to one mold piece 2A.
A set of ring pieces 9 consisting of a central groove ring piece 9A ', an inner rib ring piece 9B', a side groove ring piece 9C ', and an outer rib ring piece 9D' divided in substantially the same manner as above. Formed by the body.

Each ring piece 9A, 9 superposed in the tire axis X direction to form the mold pieces 2A, 2B respectively.
B, 9C, 9D, 9E and 9A ', 9B', 9C ', 9
D 'and 9E' are mutually fixed and integrated by a plurality of bolts 34 arranged at equal intervals in the circumferential direction as shown in FIG.

The circumferential pitch P of the bolt 34 is
In the present embodiment, for example, the lateral groove pitch Q of the inner lateral groove 22A arranged on the inner rib 1A and the number thereof are different. For example, when the number of grooves arranged in the circumferential direction of the inner lateral groove 22A is n, the pitches P and Q are prevented from being the same, for example, the number of bolts 34 is set to n + 1 or n-1.

This is because, for example, the ribs 21 on one side and the other
When the relative position of the inner lateral grooves 22A, 22A is changed between A, 21B, the rib ring piece 9B in one of them is rotated around the tire axis X and bolted to obtain the pattern shown in FIG. To the pattern of FIG.

Therefore, the embedded metal piece 6 can be relatively rotated about the tire axis between the adjacent ring pieces 9, 9 by making the circumferential pitch P of the ring pieces 9 different from the pitch Q of the lateral grooves 22. It has locking means that can lock each other.

In this embodiment, the metal fitting 6 is provided with an air hole 35 communicating with the outside air along a part of the split surface 8 between the ring pieces 9 and 9 so that the tire is directly grounded. No air holes are provided on the ground plane. Therefore, in the pneumatic tire vulcanized and molded by using the mold 1 of the present example, the tread surface 11 is formed as a smooth finished surface with less spew, which helps to improve the appearance of the tread surface 11.

However, the other one of the embedded hardware 6A, 6B
Each ring piece 9 has a thickness symmetrical with respect to the tire axis X, so that the circumferential groove 19 is formed in a normal pattern in which the circumferential grooves 19 are symmetrically arranged with respect to the tire equator C as shown in FIG. A pattern is formed.

As shown in FIG. 6, by increasing the thickness of the central groove ring 9A and reducing the thickness of the side groove ring 9B only in one of the embedded metal pieces 6A, as shown in FIG. It is possible to form an asymmetric pattern in which the groove width WG1 is increased and only the groove width WG2 on one side of the side circumferential groove 19B is narrow. Thus, by changing the basic pattern asymmetrically, it is effective to improve the rain glove and wet performance.

Further, as shown in FIG.
B, by rotating only the rib ring piece 9B 'about the tire axis X and fixing the ring piece... With bolts 34, the inner ribs 21A opposed to each other and the inner lateral groove 22A at 21A. , 22A can be relatively displaced. Due to such a displacement, noise reduction is promoted and wettability can be improved.

Further, the inner rib ring pieces 9B, 9B 'are made narrower (or wider) and the outer rib ring pieces 9D, 9D'.
Is wide (or narrow) so that the central circumferential groove 1
It is possible to change the distance J in the tire axial direction between the circumferential groove 19A and the circumferential groove 19B on the side, and even if the groove interval provided on the road differs depending on the city, the circumferential groove arrangement can cope with the city. The tire can be provided easily and at low cost.

As described above, by using the mold 1 of the present application, by combining the ring pieces 9, a tire having various patterns can be easily and quickly manufactured using the basic mold body 3 as it is. It is.

[0037]

As described above, the vulcanizing / molding mold of the present invention is provided with the above-described structure, and is capable of combining a plurality of types of tires having partially different tread patterns in a tire of the same size. Vulcanization and molding can be performed using the mold body.For example, local changes such as tread patterns to reduce noise and balance wet performance can be performed in a short period of time without renewing the entire mold. It can be carried out at a cost, and the management of the mold becomes easy.

Further, by manufacturing tires using the vulcanizing and molding dies, it is possible to repeatedly manufacture a plurality of types of tires having locally different tread patterns in a single die body. Therefore, the tuning period in the development stage can be greatly reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an embodiment of a mold of the present invention together with a tire manufactured by the mold.

FIG. 2 is a partial perspective view illustrating the embedded metal object.

FIG. 3 is a cross-sectional view illustrating an example of a pneumatic tire manufactured using the mold of the present invention.

FIG. 4 is an enlarged sectional view showing a split surface portion of an embedded metal object.

FIG. 5 is a plan view showing an example of a tread pattern of a pneumatic tire formed using the mold of the present invention.

FIG. 6 is a plan view illustrating another pattern.

FIG. 7 is a plan view illustrating another pattern.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 mold 2 mold body 3 toroidal hole 4 tread forming surface 5 recess 6 embedded metal 7 forming surface 8 split surface 9 ring piece 10 pneumatic tire 11 tread surface 19 circumferential groove 20 main groove X tire shaft

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B29C 33/38-33/42 B29C 33/02-33/08 B29C 35/02-35/04 B60C 11 / 03

Claims (4)

(57) [Claims] 1. A method for producing a pneumatic tire in which a raw tire mounted in a toroidal hole for molding is vulcanized and molded to form a pneumatic tire having a main groove including a circumferential groove extending in a circumferential direction in a tread portion. A mold body having a recess extending in a circumferential direction around a tire axis on a tread forming surface of the toroidal hole for forming a tread surface of the pneumatic tire; And a molded surface having a molding surface forming the concave portion of the tread surface of the pneumatic tire, and the embedded surface is formed by a split surface passing through a circumferential groove of the tread portion. A method for producing a tire, comprising: vulcanizing and molding using a mold for vulcanization and molding formed by combining ring pieces divided in a plurality of directions. 2. The metal fitting according to claim 1, wherein said metal fitting has a locking means between said adjacent ring pieces, said locking means being capable of rotating relative to each other about a tire axis and being locked to each other. Tire manufacturing method. 3. A molding and vulcanizing method for vulcanizing and molding a raw tire mounted in a toroidal hole for molding to form a pneumatic tire having a main groove including a circumferential groove extending in a circumferential direction in a tread portion. A mold body having a recess extending circumferentially around a tire axis on a tread forming surface of the toroidal hole for forming a tread surface of the pneumatic tire; And a molding having a molding surface forming the recessed portion of the tread surface of the pneumatic tire, and the molding is formed by a split through a circumferential groove of the tread portion. A vulcanizing and molding die formed by combining a plurality of ring pieces divided in the axial direction of the tire according to the surface. 4. The device according to claim 3, wherein the metal fitting includes a locking means between the adjacent ring pieces, the locking means being capable of rotating relative to each other about a tire axis and locking each other. Mold for vulcanization and molding.