JPS62134304A - Radial white tire - Google Patents

Abstract

PURPOSE:To stabilize the set position of a white rubber by providing a rim cushion rubber on the surface of a bead section continuous to the surface of the white rubber as well as providing an additional bar along a rim check line. CONSTITUTION:In a white tire, a white rubber 1 is disposed between a side wall section and a bead section and a rim cushion rubber 2 is disposed at the place where a rim flange touches it. Therefore, as the white rubber 1 whose modulus is 100% 1/2 in comparison with the rim cushion rubber 2 is apt to be flowed upon vulcanizing, the set position becomes unstable. To cope with this, an additional bar 8 is disposed on the upper neighboring part of a rim check line 5 annularly in the peripheral direction along said line 5. Thus, the flowing of the white rubber 1 to the lower is stopped so that the set position of a white rubber 1 is made stable.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a radial white tire that prevents white rubber from flowing during vulcanization and stabilizes the set position of the white rubber.

[Prior art]

Conventionally, white tires have been coated with white rubber I on the surface from the sidewall to the bead, as shown in Figure 2.
A rim cushion rubber 2 is arranged at a position where it contacts the rim flange. Further, between the white rubber 1 and the rim cushion rubber 2, that is, on the black lower side 3, the same rubber as the blank side wall 4 above the white rubber 1 is arranged. The bulge 5 is the mold glue line during tire vulcanization.

6 is a non-staining sheet placed on the surface of the white rubber 1 to protect the white rubber 1, and 7 is a bead wire.

As described above, although the white tire is provided with the black lower side 3, it is preferable not to provide the black lower side 3 from the viewpoint of reducing the number of parts and improving productivity. However, without the black lower side 3, the white rubber 1, which has a 100% modulus of 1/2 or less compared to the rim cushion rubber 2, would tend to flow upward or downward relative to the tire mold during vulcanization, and the center position There is a problem that it becomes unstable. If the center position becomes unstable, it becomes necessary to set the width of the white rubber l wider, and concerns remain in terms of cost and durability. In particular, if the setting position is shifted to the lower part, the white rubber 1 will move to the rim flange position, which is likely to cause a failure.

In addition, as shown in Fig. 3, originally the rim cushion rubber 2
If the black lower side 3 is placed in a position where it should exist, there is a problem that the tire will be limited in its use, such as being able to only be used under relatively low loads.

[Purpose of the invention]

The present invention prevents the white rubber from flowing during vulcanization without providing the black lower side described above, stabilizes the center position of the white rubber, reduces failures due to fewer parts, and improves durability and productivity. The objective is to provide a radial white tire with a

[Structure of the invention]

For this reason, the present invention provides a radial white tire in which white rubber is arranged on the surface from the sidewall part to the bead part. The gist of this radial white tire is that one or more additional bars are provided annularly in the circumferential direction of the tire along the rim check line above the rim check line.

Hereinafter, the configuration of the present invention will be explained in detail with reference to the drawings. Note that similar parts in FIGS. 2 and 3 are represented by the same numbers.

FIG. 1 is an explanatory diagram showing a cross section from the sidewall portion to the bead portion of an example of the radial white tire of the present invention. In FIG. 1, a rim cushion rubber 2 is provided on the surface of the bead part continuously from the surface of the white rubber 1.

As a result, the white rubber 1, which has a 100% modulus of 1/2 or less compared to the rim cushion rubber 2 as described above, is adjacent to the rim cushion rubber 2, making the set position of the white rubber 1 unstable. .

Therefore, in the present invention, the rim check line 5 of the mold is
An additional bar 8 is disposed annularly in the tire circumferential direction along the rim check line 5 adjacent to and above the rim check line 5. The number of additional bars 8 may be one or more. Further, the additional bar 8 is in the form of an annular projection, and its height is not particularly limited, but may be within a range that does not exceed the height of the white rubber 1. By providing the additional bar 8, the white rubber l
It is possible to block the flow to the bottom of the lower end of the white rubber l, and to stabilize the center position of the white rubber l.

〔Effect of the invention〕

As explained above, according to the present invention, since the rim cushion rubber is provided on the bead surface continuously from the surface of the white rubber, and the additional bar is provided along the rim check line, the following effects can be achieved. .

■ Because the black lower side has been removed, the number of parts is reduced compared to conventional white tires, which reduces failures and improves productivity.

■ The additional bar can stabilize the center position of the lower end of the white rubber, which stabilizes the set position of the entire white rubber.

■ By stabilizing the setting position of the white rubber, the width of the white rubber can be narrowed, which makes it possible to reduce the volume of the white rubber.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a cross section from the sidewall part to the bead part of an example of a radial white tire of the present invention, and FIGS. 2 and 3 are respectively a sidewall part of an example of a conventional radial white tire. FIG. 3 is an explanatory diagram showing a cross section from the to the bead portion. 1... White rubber, 2... Rim cushion rubber,
3... Black lower side, 4... Black side wall, 5... Rim check line, 6... Non-stain sheet, 7... Bead wire, 8... Additional bar. Figure 2 Figure 3

Claims (1)

[Claims] In a radial white tire in which white rubber is arranged on the surface from the sidewall part to the bead part, rim cushion rubber is provided in the bead part continuously on the back surface of the white rubber, and further, in the upper part adjacent to the rim check line of the mold, A radial white tire characterized in that one or more additional bars are provided annularly in the tire circumferential direction along the rim check line.