BACKGROUND ART

Field of the Disclosure

The present disclosure relates to a pneumatic tyre, a tyre mold, and a method for manufacturing a pneumatic tyre using the tyre mold.

Description of the Related Art

The following patent document 1 discloses a pneumatic tyre including a shoulder land portion disposed between a shoulder main groove and a tread edge. The shoulder land portion is provided with shoulder lateral grooves extending toward the tyre equator from the tread edge and shoulder lateral sipes extending to the shoulder main groove from axially inner ends of the shoulder lateral grooves.

PATENT DOCUMENT

[Patent document 1] Japanese Unexamined Patent Application Publication 2013-139194

SUMMARY OF THE DISCLOSURE

The pneumatic tyre disclosed in Patent document 1 exhibits better braking performance on wet road conditions, but there has been room for improvement in noise performance.

The present disclosure has been made in view of the above problem and has a major object to provide a pneumatic tyre capable of improving noise performance while preventing reduction in wet braking performance, a tyre mold, and a method for manufacturing a pneumatic tyre using the tyre mold.

In one aspect of the present disclosure, a pneumatic tyre includes a tread portion being provided with a land portion divided by a main groove extending continuously in a tyre circumferential direction, wherein the land portion is provided with two or more sipes having a width less than 1.5 mm on a ground contacting surface of the land portion and two or more groove elements having a width equal to or more than 1.5 mm on the ground contacting surface, lengths in a tyre axial direction of the groove elements are equal to or less than 15% of a maximum width in the tyre axial direction of the ground contacting surface of the land portion, and at least one of the sipes is in communication with one of the groove elements.

In another aspect of the disclosure, the land portion may be a shoulder land portion including a tread edge.

In another aspect of the disclosure, the lengths in the tyre axial direction of the groove elements may be smaller than lengths in the tyre axial direction of the sipes.

In another aspect of the disclosure, the sipes may include at least one first sipe extending toward a tread edge, the groove elements may include at least one first groove element in communication with the at least one first sipe, and the at least one first groove element may be arranged on the tread edge.

In another aspect of the disclosure, the at least one first groove element may have an inner end in the tyre axial direction, and a distance in the tyre axial direction between the inner end and the tread edge may be equal to or less than 5 mm.

In another aspect of the disclosure, the groove elements may include at least one second groove element arranged inwardly in the tyre axial direction of the at least one first groove element, and the sipes may include at least one second sipe extending in the tyre axial direction and being in communication with the at least one second groove element.

In another aspect of the disclosure, the sipes may include at least one third sipe extending in the tyre circumferential direction, and the at least one second groove element may be in communication with the at least one third sipe.

In another aspect of the disclosure, the sipes may include at least one third sipe extending in the tyre circumferential direction, and the at least one first sipe may be in communication with the at least one third sipe.

In another aspect of the disclosure, the sipes may include at least one fourth sipe extending inwardly in the tyre axial direction from the at least one third sipe, and the at least one fourth sipe may be bent on the ground contacting surface of the land portion.

In another aspect of the disclosure, the land portion may be a shoulder land portion including the tread edge, wherein the shoulder land portion may include a buttress portion extending inwardly in a tyre radial direction from the tread edge, the buttress portion may be provided with two or more recesses having a width equal to or more than 1.5 mm on a buttress surface, and at least one of the first sipe may be in communication with either one of the recesses.

In another aspect of the disclosure, the sipes may include a chamfered portion.

In another aspect of the disclosure, a tyre mold for manufacturing either one of the above-mentioned pneumatic tyre, the tyre mold includes a tread molding surface for molding an outer surface of the tread portion, the tread molding surface including a reference surface for molding the ground contacting surface, protrusions protruding from the reference surface for molding the groove elements, and blades embedded in the reference surface, wherein the blades include fixed portions fixed to the protrusions.

In another aspect of the disclosure, a method for manufacturing a pneumatic tyre using the above-mentioned tyre mold, the method includes forming a raw tyre, and vulcanizing the raw tyre using the tyre mold.

