Pneumatic tire and manufacturing method of pneumatic tire

A manufacturing method of a pneumatic tire comprising the steps of:

• forming an uncured tire by combining tire constituting members including a toroidal carcass which reaches a bead portion from a tread portion via a side wall portion, a tread rubber which is formed by a nonconductive rubber and is provided in an outer side of the carcass in the tread portion, and a side wall rubber which is formed by the nonconductive rubber and is provided in an outer side of the carcass in the side wall portion;
• arranging a band-like conductive tape which is formed by a conductive rubber along a tire diametrical direction, in an outer surface of the side wall rubber, exposing an outer end of the conductive tape to a ground-contacting surface or connecting an outer end of the conductive tape to a conductive rubber member which is exposed to the ground-contacting surface, and exposing an inner end of the conductive tape to a rim contact region of the bead portion or connecting an inner end of the conductive tape to a rim strip rubber which is formed by the conductive rubber;
• and
• forming a narrow groove, which is formed by depressing an outer surface of the conductive tape and extends in a tire diametrical direction in the side wall portion, only on the conductive tape by setting the uncured tire to a curing mold so as to be subjected to a vulcanizing process, and pressing a projection which is provided in an inner surface of the curing mold against the conductive tape, and
• wherein a narrow groove which extends in the diametrical direction is not formed in the nonconductive rubber of the sidewall rubber.

A manufacturing method of a pneumatic tire, comprising the steps of:

• forming an uncured tire by combining tire constituting members including a toroidal carcass which reaches a bead portion from a tread portion via a side wall portion, a tread rubber which is formed by a nonconductive rubber and is provided in an outer side of the carcass in the tread portion, and a side wall rubber which is formed by the nonconductive rubber and is provided in an outer side of the carcass in the side wall portion;
• arranging a band-like conductive tape which is formed by a conductive rubber along a tire diametrical direction, in an outer surface of the side wall rubber, exposing an outer end of the conductive tape to a ground-contacting surface or connecting an outer end of the conductive tape to a conductive rubber member which is exposed to the ground-contacting surface, and exposing an inner end of the conductive tape to a rim contact region of the bead portion or connecting an inner end of the conductive tape to a rim strip rubber which is formed by the conductive rubber;
• and
• forming a narrow groove which is formed by depressing an outer surface of the conductive tape and extends in a tire diametrical direction in the side wall portion, by setting the uncured tire to a curing mold so as to be subjected to a vulcanizing process, and pressing a projection which is provided in an inner surface of the curing mold against the conductive tape,
• wherein a plurality of the conductive tapes are arranged in such a manner as to be spaced in a tire circumferential direction and form pairs in the tire diametrical direction, and a width of one tape is made larger than a width of the other tape, in the conductive tapes which form the pair in the tire diametrical direction.

A manufacturing method of a pneumatic tire, comprising the steps of:

• forming an uncured tire by combining tire constituting members including a toroidal carcass which reaches a bead portion from a tread portion via a side wall portion, a tread rubber which is formed by a nonconductive rubber and is provided in an outer side of the carcass in the tread portion, and a side wall rubber which is formed by the nonconductive rubber and is provided in an outer side of the carcass in the side wall portion;
• arranging a band-like conductive tape which is formed by a conductive rubber along a tire diametrical direction, in an outer surface of the side wall rubber, exposing an outer end of the conductive tape to a ground-contacting surface or connecting an outer end of the conductive tape to a conductive rubber member which is exposed to the ground-contacting surface, and exposing an inner end of the conductive tape to a rim contact region of the bead portion or connecting an inner end of the conductive tape to a rim strip rubber which is formed by the conductive rubber;
• and
• forming a narrow groove which is formed by depressing an outer surface of the conductive tape and extends in a tire diametrical direction in the side wall portion, by setting the uncured tire to a curing mold so as to be subjected to a vulcanizing process, and pressing a projection which is provided in an inner surface of the curing mold against the conductive tape,
• wherein a plurality of the conductive tapes are arranged in such a manner as to be spaced in a tire circumferential direction and form pairs in the tire diametrical direction, and the conductive tapes forming the pairs in the tire diametrical direction are arranged in an offset manner so as to be inverted to each other in the tire circumferential direction.