JPH01164604A - Tire for bicycle - Google Patents

Abstract

PURPOSE:To promote the improvement of flat-tire resistance and the prevention or the like of breaking in a side part by forming a carcass layer piling together on the total surface of a cord-state belt-shaped unit of bias structure in its grounded side a separate cord-state belt-shaped unit arranged in the radial direction for the circumferential part of a tire. CONSTITUTION:A cord-state belt-shaped unit 2, providing vulcanizable rubber in the surface, is piled in a condition that a cord of the unit 2 crosses, forming the first layer having a bias structure of predetermined shape. While a separate cord-state belt-shaped unit 5, providing rubber cement or vulcanizable rubber in the surface, is piled together in a radial direction for the circumferential part of a tire 1 over the total surface of the first layer 2 in its grounded side, forming the second layer. A carcass layer 4 is formed by the first layer 2 and the second layer 5. Further, by gluing tread rubber 6 to the peripheral part of a grounded side in the carcass layer 4, the bicycle tire 1 is constituted. In this way, the tire improves flat-tire resistance while suppressing a break in a side part.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a bicycle tire, and more particularly to a bicycle tire that has improved puncture resistance and prevents damage to the side portion of the bicycle due to the rim or foreign objects on the road. This relates to tires for use.

BACKGROUND OF THE INVENTION In recent years, bicycle tires are required to have stable and high-speed running performance, and are also desired to be lightweight. In order to reduce weight, efforts are being made to make the tread rubber thinner and make the sides skinned. However, thinning the tread rubber means that when driving on the road, sharp foreign objects such as nails and broken glass can cause tires to puncture. In addition, due to the skin side of the side part, scratches may occur due to foreign objects on the side part, and cord damage (cord breakage) due to friction between the rim and the cord is likely to occur. It is desired.

In order to prevent punctures in the tread portion, a method is used in which a breaker made of woven or knitted fabric using aromatic polyamide fibers or polyester fibers is inserted between the tread rubber and the carcass layer.

Problems to be Solved by the Invention In the case where a breaker is inserted as described above, the weight increases by the breaker, increasing running resistance and causing delamination between the breaker and the tread rubber. It has its drawbacks. In addition, bead chafers are only attached to the side parts to prevent damage to the cord due to friction with the rim, but no equally effective means of prevention has been found to prevent scratches on the sides. It has not been done.

Means for Solving the Problems The present invention aims to improve this problem with bicycle tires by overlapping cord-like strips having vulcanizable rubber on their surfaces in a predetermined manner so that the cords intersect. When forming the carcass layer of a tire with a shaped bias structure, a cord-like band with rubber glue or vulcanizable rubber on the surface is layered on the ground side in a radial direction relative to the circumference of the tire. A layer is formed and tread rubber is attached to the outer periphery of the ground contact side.

Function The present invention is characterized in that a cord-like strip is installed in the radial direction around the circumference of the tire in order to improve cord breakage and puncture resistance in a tire whose carcass part has a normal bias structure. That's the point.

The cord-like belt-like body used in the present invention is one in which fibers of cotton, rayon, silk, aliphatic polyamide, aromatic polyamide, etc. are arranged in parallel, aromatic polyamide fiber and aromatic polyamide fiber. Fibers other than cotton, rayon, silk *B￥j One or more types selected from aliphatic polyamide or polyester are arranged in parallel and alternately on wooden tablets, or in parallel and arranged every other number of pieces. or cords made of twisted and twisted cords arranged in parallel, or cords made of aromatic polyamide fiber as a core thread and the above-mentioned fibers other than aromatic polyamide fibers wrapped around it, etc. be.

By installing the cord strip according to the present invention, the cord moves more flexibly and is lighter than tires using woven or knitted fabrics of aromatic polyamide or polyester fibers as ordinary precursors. The running resistance can be significantly reduced. 3.Also, while the conventional breakers are installed only at the bottom of the tread rubber, the present invention is installed over the entire surface from the tread to the side. This prevents damage caused by foreign objects and side cuts due to friction with the rim, and in some cases, the speed chafe 1- can be omitted.

Moreover, in the present invention, when stacking the cords of the carcass part, the cord-like strip is installed in the radial direction with respect to the tire circumference on the cutting line of the upper cord of the carcass part cord, so that the cutting line of the upper cord is It is possible to completely reduce the level difference caused by this, and it is possible to prevent the occurrence of cracking or peeling of the tread rubber due to this cutting line.

EXAMPLE Next, an example of a bicycle tire according to the present invention will be described with reference to the drawings.

Example 1 The first surface is the cross section I of the wire type bicycle tire 1 according to the present invention.
FIG. 2 is a perspective view with essential parts thereof cut away.

A cord-shaped strip 2 in which a vulcanizable rubber compound is applied to both sides of an aliphatic polyamide cord-shaped strip using a topping roll is cut into a bias shape, folded back at a portion corresponding to a tire bead, and a bead is formed at each folded portion. wire 3
, 3 to form a carcass layer 4. The cord-shaped strip 2 with both sides folded back is on the tire contact side, and both ends thereof form an overlapping part consisting of a total of 3 plies,
The cord-like strips were folded and overlapped, with the cords intersecting each other. Next, a cord-like band 6 made of parallel aromatic polyamide fibers with a vulcanizable rubber compound rubbed on both sides is applied in a radial direction to the tire circumference, over the entire surface of both bead areas, and over the entire surface of the tire. A wire-type bicycle tire was prepared by placing 9 strips around the circumference and pasting tread rubber 6 on the upper ground contact side of this cord-like strip.

Example 2 Completely the same as Example 1 except that instead of the cord-like belt-like body 5 in Example 1, a cord-like belt-like body in which aromatic polyamide fibers and aliphatic polyamide fibers were arranged parallel to each other every second was used. A wire bicycle tire was created in the same manner.

Example 3 A wire-type bicycle tire was manufactured in the same manner as in Example 1, except that a cord-like belt-like body in which cords made of aromatic polyamide fibers and polyester fibers were aligned in parallel was used as the cord-like belt-like body 5. Created.

Example 4 As shown in FIG. 3, the cord-like strip 5 is made of aromatic polyamide fiber as a core thread 7, and cotton fibers 8 are arranged around it.
A wire-type bicycle tire was produced in exactly the same manner as in Example 1, except that a cord-like band body made of parallel cords wound around the wire was used.

Example 6 A wire bicycle was produced in exactly the same manner as in Example 1, except that a cord-like strip made of parallel aliphatic polyamide fibers was used as the cord-like strip 6.

Example 6 The structure of a tubular tire 9 according to this example is shown in FIG.

An aliphatic cord-like strip 10 coated with vulcanizable rubber glue on both sides is cut into a bias shape, and two plies are stacked in parallel so that the cords intersect.

Next, a cord-like band 11 made of aromatic polyamide fibers and polyester fibers coated on both sides with vulcanizable rubber glue and arranged parallel to each other is placed in a radial direction relative to the tire circumference. Carcass layer 1 is arranged on the entire upper surface of the superimposed layers, and also over the entire circumference of the tire.
2, and tread rubber 13 is attached to the ground contact side.
The carcass layer 13 is sewn to form a circular cross section.

Then, a protective tape 14 made of polyester woven fabric was attached to the inner circumferential surface that would fit on the rim to produce a tubular tire. Note that 15 is a tube installed inside the carcass layer.

Comparative Example 1 In Example 1, the cord-like strip 6 was arranged, a breaker made of woven polyester fiber was placed between the sunit tread rubber part and the carcass layer around the entire tire circumference, and cotton was placed in both bead parts. A regular puncture-resistant wire-type tire was created by attaching bead tufers made of woven fabric to the entire circumference of the tire.

Comparative Example 2 In Example 1, a normal wire was used in which bead tubes 1- made of cotton woven fabric were attached to both bead portions over the entire circumference of the tire by a normal tire molding method without arranging the cord-like strip 6. I created a formula tire.

Comparative Example 3 In Example 6, without arranging the cord-like strip 11,
A conventional puncture-resistant tubular tire was prepared in which a breaker made of a woven polyester fiber was placed between the tread rubber portion and the carcass layer over the entire circumference of the tire.

Comparative Example 4 In Example 6, a normal tubular tire was produced without arranging the cord-like strip 11.

Next, in order to examine the usefulness of the bicycle tires according to the present invention, tires prepared in Examples 1 to 6 and Comparative Examples 1 to 4 were tested under the following conditions: internal pressure, load of 604, running speed of 20 km/hour.
Incline angle 0. A road surface characteristic test was conducted at a sideslip angle of o0, and the rolling resistance value was measured.

On the other hand, the same tire as above was run on a drum running test machine based on JIS-6302, and the separation state of the tread part and the state of damage to the side part due to the rim were observed. In addition, with the internal pressure of the same tire as shown below,
A razor blade with a blade length of 25 mm was set in a tensile testing machine and pressed at a moving speed of 25 #15), and the force (puncture resistance) when the razor blade punctured the tire was measured for the tread and side parts. The tread part was designed for puncture resistance, and the side part was designed for side damage caused by foreign objects.

The above results are shown in the table below.

(Left below) Effects of the Invention As is clear from the above, the bicycle tire according to the present invention can improve puncture resistance without increasing rolling resistance. Separation between the tread rubber and the carcass part due to the arrangement of the breaker does not occur, damage to the side part due to foreign matter is significantly improved, and bead chafers can be omitted.

[Brief explanation of the drawing]

FIG. 3 is a cross-sectional view of a twisted cord, and FIG. 4 is a cross-sectional view of a tubular tire according to another embodiment. 2.5... Cord-like strip body, 4... Carcass, 6... Tread rubber.

Claims (7)

[Claims] (1) A first layer consisting of a cord-like band having vulcanizable rubber on its surface, overlaid with the cords intersecting to form a bias structure in a predetermined shape, and a rubber glue or vulcanizable a carcass layer consisting of a second layer formed by stacking a cord-shaped band having rubber on the surface over the entire ground contact side of the first layer in the radial direction with respect to the circumference of the tire; and a carcass layer. A bicycle tire consisting of tread rubber attached to the outer circumference of the layer on the ground contact side. (2) The bicycle tire according to claim 1, wherein the cord-like strips stacked in the radial direction are made of cotton, rayon, silk, aliphatic polyamide fibers, or polyester fibers arranged in parallel. (3) The bicycle tire according to claim 1, wherein the cord-like strips stacked in the radial direction are made of aromatic polyamide fibers arranged in parallel. (4) A patent claim in which the cord-like band-like body stacked in the radial direction has cords made of aromatic polyamide fibers and cords made of other fibers arranged parallel to each other and alternately, parallel to each other and arranged every plural number of cords. A bicycle tire according to item 1 of the scope of the invention. (5) The bicycle tire according to claim 1, wherein the cord-like band-like body overlapped in the radial direction is made of cords made of aromatic polyamide fibers and other fibers twisted together and arranged in parallel. (6) The bicycle according to claim 1, wherein the cord-like band-like body stacked in the radial direction has cords made of aromatic polyamide fiber as a core thread and other fibers wound around the core thread, and are arranged in parallel. tires. (7) The other fiber is one or more selected from the group consisting of cotton, rayon, silk, aliphatic polyamide fiber, and polyester fiber.
Bicycle tires described in any of the above.