JPH0971112A - Pneumatic tire and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To discharge the static electricity generated on a vehicle body to a road from a tread face by providing a conducting member arranged on the inside of the tire radial direction of a tread rubber body and containing a conducting layer made of a good conducting material. SOLUTION: This pneumatic tire T is provided with a tread rubber body 2 made of an insulating material or a nonconducting material forming a tread section 1 and a conducting member 46 containing a conducting layer 3 made of a conducting material adjacent to the inner face in the radial direction, and they cover and protect the lower structural body 47 of the tire T from a side wall section 20 to a bead section 45. The conducting member 46 is constituted of the conducting layer 3 arranged below the tread rubber body 2, a penetration section 6 penetrating a tread face 1S and extended in the tire radial direction, and a conducting piece 27 buried in the tread face 1S. The second conducting member 50 is constituted of a wing rubber body 11 along the outside face of the tread rubber body 2, a conducting sheet 22 extended inward on the tread face 1S to cover the wing rubber body 11, and a color layer 26 having nearly the same structure as it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pneumatic tire capable of discharging static electricity in a vehicle to a road surface while maintaining various performances such as tire running performance, and a manufacturing method thereof.

[0002]

2. Description of the Related Art Pneumatic tires for vehicles, for example, are required to satisfy many required performances at the same time. In particular, grip characteristics on wet roads, cornering characteristics, high speed characteristics, and wear resistance characteristics are required. , Each must be optimally set. On the other hand, as the rubber material used for the tread portion of the pneumatic tire, from such a point of view, a rubber material containing silicic acid in a high proportion, such as silicon rubber, may be used.

[0003]

However, since such a rubber material is insulative or has poor electrical conductivity, there is a drawback that static electricity easily accumulates on the vehicle body on which the tire is mounted. Such accumulation of static electricity is obviously dangerous, for example, when a driver tries to open the lid of the tank at a gas station, it may cause spark discharge, and must be avoided. In addition, even if the static electricity from the car body is insufficiently escaped, for example, when you pass the joint of the bridge or the lid of the drain hole, the car radio makes a crisp noise, etc. Causes some problems, including electrical malfunctions, if not serious.

The present invention provides a conductive member including a conductive layer disposed under a tread rubber body, and / or a conductive member including a wing rubber body extending from a side wall portion along an outer surface of the tread rubber body. It is an object of the present invention to provide a pneumatic tire and a method for manufacturing the same, in which static electricity generated in a vehicle body can be discharged from the tread surface to the road, and the above problems can be solved.

[0005]

In order to achieve the above object, a first invention of the present application is to provide a tread rubber body made of an insulating material or a poorly conductive material and forming a tread portion, and the tread rubber body. And a conductive member including a conductive layer made of a good conductive material, which is disposed on the inner side in the tire radial direction, and the conductive member is exposed on the tread surface of the tire at at least one location in the tire circumferential direction. The pneumatic tire is characterized by forming a part of the tread surface.

A second invention of the present application is a tread rubber body made of an insulating material or a poorly conductive material and forming a tread portion, and a good conductivity extending from the side wall portion along the outer surface of the tread rubber body. And a conductive member including a wing rubber body made of a conductive material, the conductive member being exposed on the tread surface of the tire and forming a part of the tread surface at least at one or more locations in the tire circumferential direction. It is a pneumatic tire characterized by that.

Further, in the method for producing a pneumatic tire, at least one end surface of the belt-shaped rubber body is coated with a good conductive rubber solution as a binding promoter, and the two end surfaces of the belt-shaped rubber body are opposed to each other. It is characterized by forming a tread rubber body and vulcanizing it.

In the pneumatic tires of the first and second inventions of the present application, the conductive member made of a good conductive material is exposed on the tread surface at least at one or more locations in the tire circumferential direction, and one of the tread surfaces is exposed. Forming a part. Due to this structure, at least 1 per revolution during tire rolling
The conductive member can contact the road surface more than once, and the electric charge of the vehicle body can be released to the road surface, and the accumulation of static electricity on the vehicle body can be reliably prevented. In that case, the charge is discharged through a well-conducting tire undercarriage that joins the vehicle body with the rim as an intermediary.

What should be particularly considered as the conductive member is that it includes a conductive layer made of a good conductive rubber or a wing rubber body. In the first invention, for example, the tread rubber is penetrated from the conductive layer. By providing a penetrating portion extending outward in the radial direction, the end surface of the penetrating portion forming a part of the tread surface functions as a ground terminal. This end surface may be small, because it is sufficient for the electric charge to escape from the vehicle body to the road surface once per rotation of the tire as described above. In this way, the effect of the end face on the entire tread surface is extremely small. Therefore, even when using silicon rubber or the like for the tread rubber body, the characteristics and advantages of the tire imparted by this rubber body are Substantially maintained. As the tread rubber body, conventional natural rubber and /
Alternatively, even when a diene-based synthetic rubber is used, the configuration of the present invention can be preferably adopted when the tread rubber body has a large electric resistance and poor conductivity.

In the present application, the electric resistance value is 10 ⁷ Ω · c.
Those having a size larger than m are called insulating and poor conductivity, and those having a size less than m are called good conductivity. Examples of the good conductive rubber material include natural rubber, carbon compounds such as carbon fiber such as carbon fiber and graphite, and metal powders, metal oxides, metal flakes, metal fibers, etc. in a rubber component such as synthetic rubber. It can be obtained by adding a predetermined amount of a known metal-based conductivity imparting material.

The formation of the penetrating portion can be carried out at the time of joining the conductive rubber layer and the tread rubber body by extrusion molding or at the time of engraving the tread pattern on the tread rubber body. In either case, by appropriately setting the shape of the die of the extruder, the penetrating portion can be formed without adding an extra manufacturing process.

The through portion passes through the inside of the raised portion of the tread rubber body in the tread pattern, or passes through the boundary portion between the raised portion and the recessed groove portion of the tread pattern, whereby at least a part of the through portion is formed in the tire. Can be reliably grounded to the road surface without being damaged by wear of the tire, and this grounding is guaranteed for the entire life of the tire.

Further, the penetrating portion may be arranged in the tread central portion or the tread shoulder portion. In addition, this penetrating portion is continuous along the circumferential direction over the entire circumference of the tire,
That is, the tread surface may be formed in the shape of a band extending in the circumference, or may be provided partially at intervals in the circumferential direction, for example, dispersed in dots. What is important is that, as already described in detail, a part of the conductive member including the conductive layer comes into contact with the road surface at least once per one rotation of the tire.

In order to ensure this, at least one conductive piece made of a good conductive material can be embedded in the tread surface, and the conductive piece and the conductive rubber layer are electrically coupled. Can be achieved, for example, by additionally positively contacting a part of the conductive piece with the conductive rubber layer. The conductive pieces can be formed not only at the time of forming the tread pattern, but also by disposing the conductive pieces between two end faces of the strip-shaped rubber body forming the tread rubber body, which face each other. A conductive piece may be provided when forming the rubber body.

The object of the present application can also be achieved by disposing a conductive sheet on the tread surface of the tire, exposing the conductive sheet on the end face, and electrically coupling the conductive sheet to the conductive piece. The conductive sheet may be arranged so as to extend over the entire circumference of the tread rubber body in the circumferential direction, or may be formed in the circumferential groove, but especially in the central groove of the tread. By arranging and setting the thickness to 0.1 to 0.5 mm, preferably about 0.3 mm, it is possible to surely prevent deterioration of various characteristics of the tire.

In the second aspect of the invention, instead of the conductive layer, the wing rubber body located at the buttress portion that transitions from the side wall portion to the tread portion is formed of a good conductive rubber material. In such a case, at least one of the wing rubber bodies can be extended inward in the tire axial direction up to the tread surface, and a part of the tread surface can be formed at at least one location in the tire circumferential direction. As a result, the wing rubber body can release electric charges from the vehicle body to the road surface via the tire lower structure.

The extension of the wing rubber body is made possible by, for example, the following. That is, a thin skin portion is provided at the outer end in the radial direction of one of the wing rubber bodies so as to extend toward the inner side in the tire axial direction to form a thin outer skin and at least form a tread surface in the tread shoulder portion. With such a structure, particularly when the wing rubber body and the tread rubber body are joined by extrusion molding, the dimensions of the boundary surface between these rubber bodies are appropriately determined, and the shape of the die of the extruder is set appropriately. By doing so, a part of the material of the wing rubber body is stretched as a thin outer skin, and covers the outer surface of the tread rubber body as a thin skin portion.

Next, when the tread pattern is formed, the thin outer cover is pressed against the groove. by this,
The thin skin of the wing rubber body made of this good conductive rubber is
In particular, it also exists on the groove wall of the lateral groove that opens at the buttress portion. With this structure, even when the tire wears,
The thin skin continuously extends along the groove wall of the lateral groove to the tread surface, so that the contact between the road surface and the wing rubber body is
Guaranteed until the end of wear.

On the other hand, the thin skin portion existing on the outer surface of the raised portion of the tread pattern is worn away when the tire travels a distance of several kilometers, and as a result, a tread rubber body underneath which has excellent running characteristics appears and a predetermined tread rubber body appears. The running characteristics can be exhibited. Therefore, the thickness of the thin skin portion is set to be as thin as possible at least on the outer surface of the raised portion. Usually, the thin skin portion has a shape protruding from the main portion of the wing rubber body toward the inner side in the tire axial direction in a tapered shape (substantially wedge shape), and the thickness thereof is, for example, 0.1 to 0.2 mm on average. Is the range. The thin skin portion may extend, for example, beyond the outermost circumferential groove in the tire axial direction and further inward in the tire axial direction, but may be shorter as long as it is interposed in the tread surface.

As another structure of the conductive member, in place of the thin skin portion, the wing rubber body is electrically connected to the wing rubber body via a connecting conductive sheet which is in contact with the wing rubber body and extends on the tread surface inward in the tire axial direction. Is to provide a conductive sheet to be bonded to. This conductive sheet is in the form of a strip extending in parallel with the tire axial direction or obliquely with respect to the circumferential direction, and can be made to cross the entire width of the tire from one wing rubber body to the other wing rubber body, or The wing rubber body may be slightly extended inward in the tire axial direction. The more the conductive sheet is, the higher the discharge effect is. However, for the reason described above, one laterally long strip-shaped conductive sheet is sufficient. Further, by providing this conductive sheet on the tread surface so as to be arranged on at least a part of the ground contact surface of the tire, it is possible to conduct electricity to the road surface at all rotational positions.

However, as the electrically conductive sheet, a vertically elongated belt-like member extending in the circumferential direction over the entire circumference of the tire through the central portion of the tread surface in the axial direction of the tire can also be adopted. As a result, a high grounding effect at all rotational positions and a uniform and smooth rotation of the tire are guaranteed, which can improve safety. When arranging the conductive sheet substantially parallel to the axial direction of the tire, it is best to terminate the conductive sheet in the vicinity of the inner end which is slightly above the inner end in the radial direction of the wing rubber body, which causes peeling or tearing. It becomes difficult to lose weight.

Regarding the above structure, the conductive sheet is
In particular, it is preferable to dispose the tread pattern on the tread rubber body prior to the formation of the tread pattern. When the lateral groove is arranged in the tread pattern, the conductive sheet is arranged at the planned position of the lateral groove. This provides on the one hand manufacturing advantages and, on the other hand, ensures grounding even if the tire pattern wears. This is because, like the thin skin portion, this conductive sheet is pressed to the groove bottom along the groove wall of the lateral groove when the tire pattern is formed, and as a result, the end of wear is reached with almost no deterioration in tire characteristics. This is because the electrical continuity between the body and the road surface is maintained. The thickness of such a conductive sheet is 0.1
The conductive sheet can be extended further inward in the tire axial direction beyond the outermost circumferential groove, for example.

As another structure of the conductive member,
On the tread surface, a color layer at least partially made of a good conductive material is provided. This color layer covers the inner surface of the groove of at least one lateral groove, and exhibits a grounding effect like the conductive sheet. This color layer is particularly useful at the same time as a color code for displaying tire information and has the advantage that the tire manufacturing requires no extra steps compared to conventional tires.

Furthermore, a manufacturing method in which a good conductive rubber solution as a bonding promoter is applied to the end surface of the belt-shaped rubber body, and the two end surfaces of the belt-shaped rubber body are opposed to each other to form a tread rubber body and vulcanized In this case, since the good conductive rubber solution forms the conductive piece, the manufacturing process can be simplified, and a pneumatic tire with enhanced charge dispersion can be manufactured in substantially the same process as the conventional one. This is because the rubber solution that has been conventionally applied to the end face as a binding promoter may be simply a rubber solution having good conductivity. The bonding accelerator is necessary for holding the end face of the belt-shaped rubber body for forming the tire tread arranged in a ring on the drum during the transfer to the heating mold.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a cross section of a completed pneumatic tire. This pneumatic tire T includes a tread portion 1, a pair of side wall portions 20 extending inward in the tire radial direction from both ends thereof, and a bead located at the inner end thereof. In the present embodiment having a portion 45, it is a radial tire.

The pneumatic tire T has the tread portion 1
A tread rubber body 2 made of an insulating material or a poorly conductive material, and a conductive member 46 of the first invention including a conductive layer 3 made of a good conductive material adjacent to the inner surface in the radial direction thereof, The lower structure 47 of the tire from the side wall portion 20 to the bead portion 45 is covered and protected.

The lower structure 47 of the tire includes a carcass 12, a bead apex rubber 14, and a bead core 13.
The carcass 12 straddles between the bead cores 13 and both ends thereof are fixed for fixing.
Wrapped around the bead apex rubber 14. Further, the buttress portion 49 that transitions from the side wall portion 20 to the tread portion 1 is provided with a conductive member 50 of the second invention including a wing rubber body 11 called a wing.

Although the first and second conductive members 46 and 50 are shown in FIG. 1 for the sake of convenience, the object of the present application can be achieved by providing either one of the conductive members. However, as shown in FIG. 1, both conductive members 46, 50 may be provided.

Further, in this embodiment, the conductive layer 3 and the carcass 1 are
A belt 15 made of, for example, some steel cord plies, and a band of nylon cords covering at least both ends of the belt 15 are arranged between the two.

The tread portion 1 is engraved with a tread pattern composed of a raised portion 4 and a concave groove portion 5. The concave groove portion 5 has one end open at the buttress portion 49 and the other end at the tire. A lateral groove including at least an outer lateral groove 25 extending inward in a direction intersecting the circumferential direction, and a circumferential groove extending in the tire circumferential direction are provided. The outer lateral groove 25
May be a lug groove in which the other end is interrupted in the middle, or a so-called lateral groove continuous with the circumferential groove. Further, in the present application, the tread surface 1S means the outer surface of the tread portion 1 that can come into contact with the road surface during tire rolling, and therefore, the outer surface of the raised portion 4 is referred to as the tread surface 1S.

In this embodiment, the first conductive member 46 is also used.
Is the conductive layer 3 arranged under the tread rubber body 2, a penetrating portion 6 penetrating the tread rubber body 2 from the conductive layer 3 to the outer side in the radial direction of the tire, and a conductive material embedded in the tread surface 1S. The second conductive member 50 includes the piece 27 and the wing rubber body 11 extending along the outer side surface of the tread rubber body 2, and covers the wing rubber body 11 and extends inward on the tread surface 1S. Conductive sheet 22
And a color layer 26 having substantially the same structure as the conductive sheet 22. In the present embodiment, these first and second conductive members 4
Both 6 and 50 are made of a rubber material having good conductivity.

The arrow 17 shown in FIG. 1 represents a path through which the electrostatic charge generated in the vehicle body is discharged from the rim 18 represented by a part of the vehicle body to the tread surface 1S.

2 and 3 show an example of a combination of the tread rubber body 2 and the first conductive member 46 before the tread pattern is formed, and such a combination is formed by extrusion from one die. Achieved by machine extrusion. In the same figure, all unrelated details are omitted. In FIG. 2, a conductive layer 3 having a constant thickness is lined on the lower surface of the tread rubber body 2, and in the tread central portion 8 on the tire equator side of the tread portion 1, from the conductive layer 3 to the tread. A penetrating portion 6 that is exposed to the tread surface 1S and forms a part of the tread surface 1S by penetrating the rubber body 2 and extending outward in the tire radial direction is provided. Further, FIG. 3 shows a case where the penetrating portion 6 is arranged on each tread shoulder portion 9 on the tread edge side of the tread portion 1.

4 and 5 show another embodiment of the formation of the penetrating portions 6 after the tread pattern is formed. The tread central portion 8 has the penetrating portions 6 on both sides of the tire equator. Arranged through the rubber body 2. As can be seen from the plan view of FIG. 4, the penetrating portion 6 has a rib shape that is continuous along the circumferential direction over the entire circumference of the tire.
Passes through the raised portion 4 and is exposed as a narrow strip on the tread surface 1S.

FIGS. 6 and 7 show still another embodiment in which the penetrating portion 6 is formed after the tread pattern is formed. In the present embodiment, for example, each boundary 7 between the circumferential groove-shaped concave groove portion 5 extending in the tire circumferential direction at the tread central portion 8 and the adjacent raised portions 4 and 4 on both sides of the concave groove portion 5 is used.
A pair of rib-shaped penetrating portions 6, 6 passing above are tread surfaces 1S.
To expose. The rubber 5G interposed between the respective through portions 6, that is, the groove bottom of the concave groove portion 5 is also the conductive layer 3 as in the present embodiment.
The same tread rubber body 2 may be formed between the penetrating portions 6 by integrally forming the same rubber material. Further, as can be seen from FIG. 6, the end surface of the penetrating portion 6 exposed on the tread surface 1S has notches 51 and extends intermittently in the tire circumferential direction.

FIGS. 8 and 9 show still another embodiment of the formation state of the penetrating portion 6 after the tread pattern is formed. In the present embodiment, the penetrating portion 6 penetrates the tread rubber body 2 as a pin body having an end surface in the shape of a dot 10 such as a circle or a rectangle, and reaches the tread surface 1S. This pin-shaped penetrating portion 6 may also be arranged in the raised portion 4 or on the boundary 7 between the raised portion 4 and the concave groove portion 5, and further,
It can also be dispersed uniformly or non-uniformly over the entire circumference of the tire.

FIGS. 10 (a) -10 (c) show extrusion molding,
The structure of each rubber body before molding when a part of the conductive layer 3 forms the through portion 6 by vulcanization molding or the like is shown. FIG. 10A is a sectional view of the tread rubber body 2.
10B is a sectional view of the conductive layer 3, and FIG. 10C is a plan view of the conductive layer 3. 10 (b), 10
As shown in (c), it is not necessary to accumulate a large amount of rubber material for forming the penetrating portion 6 in a portion where a part of the conductive layer 3 will form the penetrating portion 6. The thickened portion 19 is sufficient. This thickened portion 19
The flow of the rubber material when forming the tread tire pattern penetrates the tread rubber body 2 and extends to the tread surface 1S.

11 and 12 show another embodiment of the arrangement of the penetrating portion 6. As shown, the penetrating portion 6 may be disposed on either one or both of the tread central portion 8 and the tread shoulder portion 9, and at that time, the penetrating portion 6 may be formed in the raised portion 4 or in the raised portion 4 and the concave groove portion 5. The end surface of the tread surface 1S becomes a part of the tread surface 1S by passing through one of the boundaries 7 between and. Further, the penetrating portion 6 may be formed in a rib shape extending continuously or intermittently in the circumferential direction, or the pin-shaped penetrating portion 6 may be dispersed in a dot shape. It is to provide the penetrating portion 6 that can maintain the conduction between the road surface and the conductive layer 3 even when the tire pattern is worn away.

As the first conductive member 46, instead of the penetrating portion 6, as shown in FIG.
It is also possible to use a conductive piece 27 embedded in the
7 is electrically coupled to the conductive layer 3 through the joint portion 27A. The difference between the penetrating portion 6 and the conductive piece 27 is that
In terms of its formation, the through-hole 6 is made of the same rubber material as the conductive layer 3, whereas the conductive piece 27 is embedded from the tread surface side, so that a material different from that of the conductive layer 3 can also be adopted. ,
Further, its cross-sectional area is at least larger than that of the joint portion 27A.

FIG. 13 shows one form of the second conductive member 50. Here, the conductive member 50 is formed of only the wing rubber body 11 extending from the side wall portion 20 along the outer surface of the tread rubber body 2.
In No. 1, the end surface 11S on the upper side in the tire radial direction has a width and is exposed by having a substantially uniform thickness, and the end surface 11S with a width forms a part of the tread surface 1S. At this time, the tread rubber body 2 is formed narrower as the thickness of the wing rubber body 11 increases. Such a wing rubber body 11 may be provided over the entire circumference of the tire or may be provided partially. The wing rubber body 11 may be provided on each of the buttress portions 49, 49 on both sides of the tire as in the present embodiment, but may be provided on only one of the buttress portions 49.

FIG. 14 shows another form of the second conductive member 50. In this embodiment, the wing rubber body 11 has a main portion 11A extending along the outer side surface of the tread rubber body 2,
Tread rubber body 2 made of the same rubber material as the main portion 11A
And a thin skin portion 21 extending to the outer surface. The thin skin portion 21 is
For example, the thin skin portion 21 has a thickness of 0.1 to 0.2 mm, extends inward from the main portion 11A in the axial direction of the tire, and is embedded in the tread rubber body 2 by the thickness. A part of the tread surface 1S is formed in the shoulder portion. Such a thin skin portion 21 is obtained especially when the tread rubber body 2 and the wing rubber body 11 are joined by extrusion molding, and at that time, the size of the boundary 23 between the wing rubber body 11 and the tread rubber body 2 is adjusted. By appropriately setting, a part of the rubber of the wing rubber body 11 extends on the tread rubber body 2 to form the thin skin portion 21.

FIG. 15 shows another form of the second conductive member 50. Here, the conductive member 50 has a wing rubber body 11 having substantially the same shape as that of the conventional one as shown in FIGS. And a wing rubber body 11 having a substantially triangular cross-section that forms a vertex, and a tread surface 1S that is adjacent to the outer surface of the wing rubber body 11 and that extends beyond the vertex.
The thickness that extends inward in the axial direction of the tire is 0.1 to 0.5 m
m, for example, a conductive sheet 22 of about 0.25 mm. That is, the conductive sheet 22 is the wing rubber body 11.
And both the tread rubber body 2 are covered. The conductive sheet 22
Is the inner end 24 of the wing rubber body 11 in the radial direction.
Of the outer lateral groove 25 (see FIG. 1).
(Shown in FIG. 3) extends to a position covering the planned formation position. As a result, when the tread pattern is formed, the conductive sheet 22 is pressed into the outer lateral groove 25 by pushing the pattern, so that the groove wall and the groove bottom are lined. As a result, the electrical continuity between the tread surface 1S and the wing rubber body 11 is maintained even if the tire pattern is worn by the lining portion 22A of the conductive sheet 22. On the other hand, the protruding portion 22B of the conductive sheet 22 existing on the outer surface of the raised portion 4 is worn out by using the tire for several kilometers, and the tread rubber body 2 under the tire is worn away.
To expose. Such a conductive sheet 22 can be extended further to the inner side in the tire axial direction, for example, beyond the outermost circumferential groove in the tire axial direction.

By using colored rubber such as white rubber for the conductive sheet 22, the conductive sheet 22 can be formed as the color layer 26 for makeup (shown in FIG. 1). At that time, The color layer 26 may include an identification code that displays tire information.

FIG. 16 shows another embodiment of the present invention.
In the present embodiment, the pneumatic tire is made of an insulating material or a poorly conductive material and forms a tread portion 1 with a tread rubber body 2, and a tread rubber body 2 is arranged radially inward of the tread rubber body 2 and made of a good conductive material. The first conductive member including the conductive layer 3 is provided to cover and protect the lower structure from the sidewall portion 20 to the bead portion.

The wing rubber body 1 is attached to the buttress portion.
1, a belt 15 made of two belt plies in which steel cords are arranged, and a nylon cord band 16 are disposed between the conductive layer 3 and the carcass 12.

The wing rubber body 11 and the carcass 1
2, the belt 15 and the band 16 are made of rubber or other material having good conductivity.

Further, the tread surface 1S is provided with a concave groove portion 31 extending in the circumferential direction on the tire equator I, and the conductive sheet 28 extending continuously in the circumferential direction from the groove bottom 32 of the concave groove portion 31 to the tread surface 1S is embedded. Has been done. The conductive sheet 28 has a thin thickness that does not impair the running characteristics of the tire, and is preferably 0.1 to 0.5 mm, more preferably about 0.3 mm. Therefore, even if the tread surface 1S is worn, the conductive sheet 2 is not attached to the tread surface 1S.
8 can be exposed. The conductive sheet 28
Is made of rubber or other material with good conductivity.

Further, as shown in FIG. 17, the conductive sheet 28 has a strip-shaped rubber body 38 forming the tread rubber body 2.
The end edges 33 and 34 of the conductive sheet 28 form a part of two end surfaces 29 and 30 of the strip-shaped rubber body 38 that face each other.

The end faces 29, 3 of the belt-shaped rubber body 38 are also
Between 0, by contacting the end faces 35, 36 of the conductive layer 3 and the end faces 39, 40 of the wing rubber body 11, a conductive piece 37 which can be electrically coupled to the conductive layer 3 and the wing rubber body 11. (Indicated by a broken line in FIG. 17) is provided, so that the conductive sheet 28 is electrically coupled to the conductive layer 3 and the wing rubber body 11 via the conductive piece 37. Electrostatic charges generated in the vehicle body are transferred from the vehicle body to the rim 18, carcass 12, belt 15, band 16, conductive layer 3, conductive piece 3
7 is transmitted to the conductive sheet 28 and is released to the road surface.

FIG. 18 shows a conductive sheet 22 arranged on the tread surface 1S and oriented at right angles to the circumferential direction (shown by a chain line in FIG. 16).
The two wing rubber bodies 11, 11 are electrically coupled.
The conductive sheet 22 is preferably the wing rubber body 11
Is interrupted above the inner end 24 of the. Therefore, the conductive sheet 22 forms a part of the groove wall surface of the outer lateral groove 25 extending at right angles or obliquely with respect to the tire circumferential direction. As a result, even when the tread surface 1S is worn out, the tread surface 1S
The electrical connection between the wing rubber body 11 and the wing rubber body 11 is maintained.
Electrostatic charges generated in the vehicle body are transferred from the vehicle body to the rim 18, the carcass 12, the sidewall portion 20, the wing rubber body 1.
1 is transmitted to the conductive sheet 22 and is discharged to the road surface.
Note that the configurations of FIGS. 17 and 18 may be combined.

Further, as shown in FIG. 19, the conductive sheet 28 continuously extending in the circumferential direction on the tread surface 1S of the belt-shaped rubber body 38 in the tire equator I is made of, for example, rubber having good conductivity which extends in the tire axial direction. It is also possible to electrically connect to one of the wing rubber bodies 11 via the connecting conductive sheet 41.

The connecting conductive sheet 41 preferably forms at least a part of the groove wall surface of the groove portion that extends at right angles or obliquely with respect to the tire circumferential direction. The electrostatic charge generated in the vehicle body is transmitted from the vehicle body to the conductive sheet 28 through the rim 18, the carcass 12, the sidewall portion 20, the wing rubber 11, and the connecting conductive sheet 41, and is discharged to the road surface. The one shown in FIG. 17 may be combined with the one shown in FIG.

Further, in the conductive piece 37 shown in FIG. 17, at least one end surface 29, 30 of the band-shaped rubber body 38 is coated with a good electric rubber solution as a binding accelerator, and then the two of the band-shaped rubber body 38 are applied. By forming the tread rubber body 2 by facing the end faces 29 and 30 and vulcanizing, the tread rubber body 2 can be formed without increasing the manufacturing process.

Further, the conductive sheet 22 and the connecting conductive sheet 41 embedded in the tread rubber body 2 are also bonded to the tread rubber body 2 with a good conductive rubber solution as a binding accelerator before the tire is vulcanized and molded. It can be arranged by applying to the rubber body 11. The rubber solution is pushed into the tread rubber body 2 by vulcanization and vulcanized together to form the conductive sheet 22 and the like.

The conductive sheet 28 shown in FIG. 17 can also be attached to the tread rubber body 2 by the same method, but the conductive sheet 28 is attached to the tread rubber body 2 of the tire which has been previously vulcanized in a heated mold. Can be adhered, and this can be applied to the conductive sheet 22 and the connection conductive sheet 41.

Further, as shown in FIG. 20, a tread rubber body 2 containing silicic acid as a main reinforcing element and having high electrical resistance is penetrated from the tread surface 1S to the bottom portion within the width TR in the tire axial direction. And extends in the circumferential direction and has an electric resistance value of 10 ⁸ Ω · cm, more preferably 10 ⁶ Ω.
・ Conductive member 5 consisting of so-called conductive member smaller than cm
By arranging 3 substantially in the center of the tire axial direction,
The penetrating portion 6 can be formed by the conductive member 53.

Further, as shown in FIG. 21, the penetrating portion 6
The width of the groove is wider than the width of the widest concave groove portion 5 extending in the circumferential direction so that the penetrating portion 6 can be surely exposed on the tread surface 1S, and the contact failure of the penetrating portion 6 to the road surface due to abrasion of the tread surface 1S. It is also possible to prevent.

Further, as shown in FIG. 22, the tread rubber body 2
A conductive member 54 having an electric resistance value of 10 ⁸ Ω · cm or less, more preferably 10 ⁶ Ω · cm or less, on both sides in the tire axial direction,
55 is distributed, and after the tire is formed, the conductive member 5
The wing rubber bodies 11, 11 may be formed of 4, 55.

The width of the conductive members 53, 54, 55 in the tire axial direction is 5 to the width TR of the tread rubber body 2.
It is desirable to set it to 25% from the viewpoint that the electric charge can be surely dispersed and various characteristics of the tread portion such as running performance can be maintained.

[0060]

As described above, the pneumatic tire of the present invention is
At least 1 per rotation of the tire via the conductive member
It can have electrical continuity with the road and the road surface, and can discharge the static electricity of the vehicle body to the road surface. As a result, it is possible to effectively prevent the occurrence of danger due to spark discharge and the induction of malfunction of instruments and electric devices due to the accumulation of static electricity.
At the same time, even when a rubber material containing a high proportion of silicic acid, such as silicon rubber, is used in the tread portion, the exposure on the tread surface of the conductive member is extremely small, so the excellent running of the rubber material in the tread portion The characteristics can be maintained. Further, the conductive piece of the conductive member can be easily formed by using a good conductive rubber solution, and no extra step is required for manufacturing, and the manufacturing process can be simplified.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a pneumatic tire showing an example of an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing an example of a combined state of a conductive layer and a tread rubber body before forming a tread pattern.

FIG. 3 is a cross-sectional view showing another form of a combined state of the conductive layer and the tread rubber body before forming the tread pattern.

FIG. 4 is a plan view showing an example of a combined state of a conductive layer and a tread rubber body after forming a tread pattern.

FIG. 5 is a sectional view of FIG. 4;

FIG. 6 is a plan view showing another form of the combined state of the conductive layer and the tread rubber body after forming the tread pattern.

7 is a cross-sectional view of FIG.

FIG. 8 is a plan view showing still another form of the bonded state of the conductive layer and the tread rubber body after forming the tread pattern.

FIG. 9 is a sectional view of FIG. 8;

FIG. 10A is a sectional view showing a tread rubber body before forming a tread pattern. (B) is a cross-sectional view showing a conductive layer lined on the lower surface thereof. (C)
It is the top view.

FIG. 11 is a plan view showing still another form of the combined state of the conductive layer and the tread rubber body after forming the tread pattern.

12 is a cross-sectional view of FIG.

FIG. 13 is a cross-sectional view showing an example of a joined state of a wing rubber body and a tread rubber body before forming a tread pattern.

FIG. 14 is a cross-sectional view showing another form of the joined state of the wing rubber body and the tread rubber body before forming the tread pattern.

FIG. 15 is a cross-sectional view showing still another form of the joined state of the wing rubber body and the tread rubber body before forming the tread pattern.

FIG. 16 is a cross-sectional view of a pneumatic tire showing another embodiment of the present invention.

FIG. 17 is a schematic plan view showing a belt-shaped rubber body, a conductive piece, and a conductive sheet before forming a tread pattern.

FIG. 18 is a schematic plan view showing a belt-shaped rubber body and a conductive sheet before forming a tread pattern.

FIG. 19 is a schematic plan view showing a belt-shaped rubber body and a conductive sheet before forming a tread pattern.

FIG. 20 is a cross-sectional view showing a tread rubber body before forming a tread pattern.

FIG. 21 is a cross-sectional view showing a tread rubber body.

FIG. 22 is a cross-sectional view showing a tread rubber body before forming a tread pattern.

[Explanation of symbols]

 1 Tread Part 1S Tread Surface 2 Tread Rubber Body 3 Conductive Layer 4 Tread Pattern Ridge 5 Tread Pattern Recessed Groove 6 Penetration 7 Boundary 8 Tread Central 9 Tread Shoulder 10 Dot 11 Wing Rubber 12 Carcass 13 Bead Core 14 Bead apex rubber 15 Belt 17 Arrow 18 Rim 20 Side wall part 21 Thin skin part 22, 28 Conductive sheet 25 Transverse groove 26 Color layer 27 Conductive piece 29, 30 End surface 37 Conductive piece 38 Belt-shaped rubber body 41 Connected conductive sheet 46, 50, 53, 54, 55 conductive member

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Jürgen Schonburg Federal Republic of Germany, Rodenbachx, 63517, Wingert Strasse 11 (72) Inventor Wihelm Endless Federal Republic of Germany, Hasselloth, 63594, Berliner Strasse 22 Beh (72) Invention Hubert Reinbeber Germany, Hanau, 63454, Karlsbader Strasse 17

Claims (31)

[Claims] 1. A tread rubber body which is made of an insulating material or a poorly conductive material and forms a tread portion, and a conductive layer which is disposed inside the tread rubber body in the tire radial direction and which is made of a good conductive material. And a conductive member, the conductive member being exposed on the tread surface of the tire and forming a part of the tread surface at least at one or more locations in the tire circumferential direction. 2. The pneumatic tire according to claim 1, wherein the conductive layer comprises a conductive rubber layer backed by a tread rubber body. 3. The conductive member is made of rubber of the same quality as that of the conductive rubber layer, and extends through the tread rubber body from the conductive rubber layer to the outer side in the tire radial direction to be exposed on the tread surface. The pneumatic tire according to claim 2, further comprising a penetrating portion that forms a part of the tread surface. 4. The penetration portion is penetrated through the tread rubber body and exposed to the tread surface when the conductive rubber layer and the tread rubber body are integrally joined by extrusion molding. Pneumatic tire described. 5. The pneumatic tire according to claim 3, wherein the penetrating portion penetrates the tread rubber body and is exposed on the tread surface when the tread pattern is engraved on the tread rubber body. 6. The pneumatic tire according to claim 3, wherein the penetrating portion passes through the inside of the raised portion of the tread rubber body in the tread pattern. 7. The pneumatic tire according to claim 3, wherein the penetrating portion passes through a boundary between a raised portion and a concave groove portion of the tread rubber body in the tread pattern. 8. The pneumatic tire according to claim 3, wherein the penetrating portion is exposed on a tread surface in a tread central portion which is a tire equator side of the tread portion. . 9. The pneumatic tire according to claim 3, wherein the penetrating portion is exposed on a tread surface in a tread shoulder portion which is a tread edge side of the tread portion. 10. The pneumatic tire according to claim 3, wherein the penetrating portion is exposed on the tread surface continuously along the circumferential direction over the entire circumference of the tire. . 11. The through-holes are exposed on the tread surface at intervals in the circumferential direction.
The pneumatic tire according to any one of 1. 12. The pneumatic tire according to claim 11, wherein the penetrating portions are dispersed in a dot shape over the entire circumference of the tire and are exposed on the tread surface. 13. The pneumatic tire according to claim 2, wherein the conductive member includes a conductive piece embedded in the tread surface and electrically coupled to the conductive rubber layer. 14. The pneumatic tire according to claim 13, wherein the conductive piece is arranged between two end surfaces of the strip-shaped rubber body forming the tread rubber body that face each other. 15. The pneumatic tire according to claim 1, wherein the conductive member comprises a conductive sheet which is arranged on a tread surface of the tire and forms a part of the tread surface. 16. The pneumatic tire according to claim 14, wherein the conductive piece is electrically coupled to the conductive sheet. 17. The conductive sheet forms a part of the end surface of the belt-shaped rubber body.
The pneumatic tire according to item 5. 18. The conductive sheet extends in the circumferential direction over the entire circumference of the tread rubber body.
The pneumatic tire according to any one of items 1 to 17. 19. The conductive sheet is arranged from the groove bottom of the groove portion extending in the circumferential direction to the tread surface, and extends along the groove portion.
The pneumatic tire according to any one of 1. 20. The pneumatic tire according to claim 15, wherein the conductive sheet is arranged on a tread rubber body at a tread central portion of the tread portion on a tire equator side. . 21. The conductive sheet has a thickness of 0.1 to 10.
The pneumatic tire according to claim 15, wherein the pneumatic tire has a thickness of 0.5 mm. 22. A wing rubber body made of an insulating material or a poorly conductive material and forming a tread portion, and a wing rubber body made of a good conductive material extending from a side wall portion along an outer surface of the tread rubber body. And a conductive member including the conductive member, the conductive member being exposed on the tread surface of the tire and forming a part of the tread surface at least at one or more locations in the tire circumferential direction. tire. 23. The wing rubber body extends to the tread surface so that at least one of the wing rubber bodies extends in the tire circumferential direction.
The pneumatic tire according to claim 22, which forms a part of the tread surface at the above-mentioned location. 24. The wing rubber body has a thin skin portion at an outer end in the tire radial direction, which extends on the tread rubber body toward the inner side in the tire axial direction, and the thin skin portion at least in a tread shoulder portion. The pneumatic tire according to claim 23, wherein a surface is formed. 25. The pneumatic tire according to claim 24, wherein the thin skin portion is formed when the wing rubber body and the tread rubber body are integrally joined by extrusion molding. 26. The conductive member is electrically coupled to the wing rubber body via a connecting conductive sheet that is in contact with the wing rubber body and extends on the tread surface inward in the tire axial direction, and is also connected to the ground contact surface of the tire. 23. The pneumatic tire according to claim 22, comprising at least one electrically conductive sheet at least a part of which is arranged. 27. At least one of the tread portions extends from the wing rubber body in a direction intersecting a tire circumferential direction.
While having a tread pattern including one lateral groove, the conductive sheet is arranged on the tread rubber body to cover the planned position where the at least one lateral groove is formed prior to the formation of the tread pattern. The pneumatic tire according to claim 26. 28. The conductive sheet continuously extends along the circumferential direction over the entire circumference of the tire and covers at least a part of both the wing rubber body and the tread rubber body. Item 27. The pneumatic tire according to Item 27. 29. At least one tread portion extends from the wing rubber body in a direction intersecting a tire circumferential direction.
The conductive member has a tread pattern including two lateral grooves, and the conductive member includes a colored layer of a good conductive material disposed on the tread surface at least at one or more locations in the tire circumferential direction, and The pneumatic tire according to claim 22, wherein a layer covers a groove wall surface of the lateral groove. 30. The pneumatic tire according to claim 29, wherein the color layer has an identification code indicating tire information. 31. The method for manufacturing a pneumatic tire according to claim 1, wherein a good conductive rubber solution as a bonding accelerator is applied to at least one end surface of the belt-shaped rubber body. 2. A method for producing a pneumatic tire, which comprises forming a tread rubber body by facing two end faces of the above and vulcanizing the tread rubber body.