JPH078601B2 - Radial white tires - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a radial white tire that prevents the flow of white rubber during vulcanization and stabilizes the set position of the white rubber.

[Prior art]

Conventionally, as shown in FIG. 2, a white tire has a white rubber 1 on the surface from the side wall portion to the bead portion.
And 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 black side wall 4 above the white rubber 1 is arranged. The bulge of 5 is a rim check line. The mold for tire vulcanization has a rim check line forming recess at a position corresponding to the rim check line. 6 is white rubber 1
A non-stain sheet, which is arranged on the surface of the white rubber 1 for the purpose of protection, is a bead wire.

As described above, in the white tire, the black lower side 3 is provided, but 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 Black Lower Side 3, 100% modulus is 1 compared to Rim Cushion Rubber 2.
The white rubber 1 having a ratio of / 2 or less is easily flown to the upper part or the lower part of the tire mold during vulcanization, which causes a problem that the set position becomes unstable. When the set position becomes unstable, it is necessary to set the width of the white rubber 1 wide, and there are concerns about cost and durability. Especially when the set position is flown downward, the white rubber 1 is likely to move to the rim flange position and cause a failure.

Further, as shown in FIG. 3, the rim cushion rubber 2 is originally
If the black lower side 3 is arranged up to the position where should exist, there is a problem that the tire is limited such that it can be used only in a relatively low load range.

[Object of the Invention]

The present invention prevents the flow of white rubber during vulcanization without providing the black lower side described above, stabilizes the set position of the white rubber, reduces failures by reducing parts, and improves durability and productivity. The purpose of the present invention is to provide a radial white tire.

[Structure of Invention]

Therefore, the present invention is a radial white tire in which white rubber is arranged on the surface from the side wall portion to the bead portion, and the rim cushion rubber is continuous to the bead portion side back surface of the white rubber and is in close contact with the white rubber. Along the rim check line, one or more additional bars formed by the white rubber flowing into the groove on the inner surface of the mold during vulcanization are provided in the bead portion and adjacent to the rim check line on the surface of the bead portion. It is characterized in that it is provided so as to protrude annularly in the tire circumferential direction.

As described above, in the present invention, the rim cushion rubber is provided in the bead portion so as to be continuous with the back surface of the bead portion side of the white rubber and in close contact with the white rubber, and one or more additional bars are provided along the rim check line. Since it is provided so as to project in an annular shape in the tire circumferential direction, during vulcanization, white rubber will flow into the groove on the inner surface of the mold that corresponds to the additional bar, so that the flow of white rubber to the bottom is stopped, so white It is possible to stabilize the rubber setting position.

Hereinafter, the configuration of the present invention will be described in detail with reference to the drawings. The same parts as those in FIGS. 2 and 3 are represented by the same numbers.

FIG. 1 is an explanatory view showing a cross section from a side wall portion to a bead portion of an example of the radial white tire of the present invention. In FIG. 1, a rim cushion rubber 2 is provided in the bead portion so as to be continuous with the back surface of the white rubber 1 on the bead portion side and in close contact with the white rubber 1. As a result, as compared with the rim cushion rubber 2, as described above,
The white rubber 1 having a 0% modulus of 1/2 or less is adjacent to the rim cushion rubber 2, and the set position of the white rubber 1 becomes unstable.

Therefore, in the present invention, an additional bar formed by flowing white rubber into the groove portion on the inner surface of the mold at the time of vulcanization, in the upper portion adjacent to the rim check line 5 on the bead surface (outer side of the rim check line 5 in the tire radial direction). 8 is arranged along the rim check line 5 so as to project annularly in the tire circumferential direction. The additional bar 8 may be one or more.
Further, the additional bar 8 is in the form of an annular protrusion, and its height is not particularly limited, but may be within a range not exceeding the height of the white rubber 1. By providing the additional bar 8, the flow of the lower end of the white rubber 1 to the lower part can be blocked, and the setting position of the white rubber 1 can be stabilized.

〔The invention's effect〕

As described above, according to the present invention, the rim cushion rubber is provided on the bead portion so as to be continuous with the bead portion-side rear surface of the white rubber and in close contact with the white rubber. Since one or more additional bars formed by the inflow of rubber are provided so as to project in the tire circumferential ring shape along the rim check line, the following effects can be achieved.

Since the black lower side is removed, the number of parts is reduced compared to conventional white tires, which can reduce failures and improve productivity.

Since the setting position of the lower end portion of the white rubber can be stabilized by the additional bar, the setting position of the entire white rubber is stabilized.

By stabilizing the setting position of the white rubber, the width of the white rubber can be narrowed, which allows the volume of the white rubber to be reduced.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a cross section from a side wall portion to a bead portion of an example of a radial white tire of the present invention, and FIGS. 2 and 3 are side wall portions of an example of a conventional radial white tire, respectively. It is explanatory drawing which showed the cross section from a to a bead part. 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.

Claims (1)

[Claims] 1. A radial white tire having a white rubber disposed on a surface thereof from a side wall portion to a bead portion, wherein a rim cushion rubber is continuously formed on the bead portion side back surface of the white rubber and is in close contact with the white rubber. In addition, one or more additional bars formed by flowing white rubber into the groove on the inner surface of the mold at the time of vulcanization are provided above the rim check line on the surface of the bead portion along the rim check line. A radial white tire that is provided so as to project in an annular shape in the circumferential direction.