JPS60240505A - Radial tire - Google Patents

Abstract

PURPOSE:To enhance the uniformity, durability, and weight-reduction by constituting a pry by means of a knitted cloth fabricated by knitting the warps, which are arranged in parallel with each other, by using knitting threads made up of fine fibers, together with forming a carcass by arranging the warps in parallel with each other in the radial direction of a tire. CONSTITUTION:A knitted cloth 10 is formed by arranging warps 11 made up of nylon or the like in parallel with each other and knitting the warps 11 by using knitting threads 13 and 14 made up of fine fibers of nylons 6 or the like along the longitudinal direction of the warps 11. In this case, the diameter of the knitting threads 13 and 14 is set at 5 to 80 deniers. After the bonding- and topping rubber-treatment, this knitted cloth 10 is imbedded into rubber to becom a reinforcing member, and it is arranged so that the warps 11 are lined up in parallel with each other with respect to the radial direction of the tire, before it is placed in use. With this constitution, the uniformity, durability and weight- reduction of a tire can be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a radial tire using a knitted fabric as the carcass.

Generally, the carcass of a pneumatic tire is made of a fabric in which tire cords, which mainly serve as reinforcing elements, are arranged as warp threads, and the weft threads, which are thinner than the warp threads, are loosely woven to maintain the spacing between the warp threads.

This blind fabric is woven by alternately opening the warp threads, driving the weft threads in with a shuttle, beating the cloth, then opening the warp threads upside down and driving the weft threads in again.

When the blind fabric is used for a carcass, it is cut to a predetermined size after being worked in a depping calender, and then formed using a cylindrical drum. Thereafter, it is inflated into a toroidal tire and vulcanized in a mold. In these processes, the warp and weft are not sufficiently fixed to each other due to the fabric structure, and the spacing between the warp and weft tends to be disturbed due to uneven compression and expansion, resulting in uneven end distribution in the finished tire. Tire uniformity and durability will be impaired.

Due to the structure of bamboo blind fabric, the warp yarns are wavy, resulting in a so-called ``tatami matome'' (tatami matome) pattern, which increases the thickness of the fabric itself.As a result, in order to prevent the cords between the plies from touching each other, the thickness of the topping rubber must be increased. This becomes necessary and is disadvantageous from the viewpoint of reducing the weight of the tire. Furthermore, since blind fabrics are woven with openings, their production capacity is limited, and it is necessary to select materials that will prevent the weft and warp from slipping.Therefore, the use of long fibers for the weft poses problems.

The present invention solves all the shortcomings of the blind fabrics conventionally used in the carcass of tires, and by using maple knitted fabric in the carcass instead of the blind fabric described above, the uniformity, durability, and weight reduction of the tire are further improved. The purpose of this project is to propose a radial tire that can

The present invention comprises a pair of left and right bead cores, a toroidal carcass that is secured by folding both ends around the bead cores, a belt layer in which cords are arranged at a shallow angle in the tire circumferential direction on the crown portion of the carcass, and The carcass includes a tread portion disposed outside the belt layer, and the carcass is a ply made of a knitted fabric in which warp threads are aligned parallel to each other and at regular intervals, and the warp threads are knitted with knitted yarns of fine fibers. , is a radial tire characterized in that its warp threads are arranged substantially parallel to the tire radial direction.

An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 shows the right half of a sectional view of the radial tire of the present invention. In the figure, a radial tire T includes a bead core 1, a toroidal carcass 2.3 that is secured by folding the end around the bead core 1, and cords arranged at a relatively shallow angle in the tire circumferential direction on the outside of the crown of the carcass. a belt layer 5, a tread portion 6 disposed on the outside of the belt layer, the carcass 2.3 and its folded portion 2a.
, 3a, and extends from the bead core 1 in the sidewall direction.
is located.

Here, the carcass is made of knitted fabric, unlike the conventional blind fabric.

FIG. 2 shows a schematic diagram of the surface of the knitted fabric used in the radial tire of the present invention. In the figure, the knitted fabric (10) has warp threads (1
1) are arranged parallel to each other, and these warps are knitted with a plurality of fine fiber knitting yarns (13) (14) along the longitudinal direction of the warps.
By knitting, the warp threads are integrated to form a knitted fabric.

The knitting method here can be a stockinette knitting method that has been widely adopted in the past, such as warp stockinette knitting or horizontal stockinette knitting, and a Raschel knitting machine can be used as the knitting machine.

Various materials can be used for the warp yarns, including organic fibers such as nylon, polyester, rayon, and aromatic polyamide, and inorganic fibers such as steel and glass fibers.

Next, the knitting yarn used in the present invention may be made of a material that sufficiently withstands general adhesive treatment and heat treatment conditions in tire manufacturing processes, and preferably adheres to rubber after treatment, such as nylon 6, nylon 66, Filaments of organic fibers such as polyester and having a fiber diameter of 5 to 80 deniers are used. If the filament diameter is smaller than 5 deniers, the fixing strength between the warp and weft is not sufficient.

On the other hand, if the filament diameter exceeds 80 denier, the thickness of the knitted fabric increases, resulting in an increase in ply gauge, which is disadvantageous from the viewpoint of weight reduction, and furthermore, durability decreases due to rubbing between the knitting yarn and the warp yarn.

The knitted fabric obtained as described above is subjected to conventional adhesive treatment and heat treatment, followed by topping rubber treatment, and silk cloth is embedded in the rubber to form a reinforcing material.

FIGS. 3 and 4 show schematic diagrams of the front and back surfaces of another silk cloth used in the radial tire of the present invention, respectively.

In the figure, the knitted fabric (20) is made by arranging warp threads (21) parallel to each other at regular intervals and knitting with pure fine fibers (23) and (24) along the longitudinal direction of these warp threads. form.

The silk cloth obtained in this way has a high elongation in the width direction, that is, in the direction perpendicular to the longitudinal direction of the warp, for example, 10% or more, and through processing steps such as topping and cutting of the silk cloth, the warp threads are mutually Maintaining uniform spacing. In particular, when this silk cloth is used for the carcass, the warp threads expand at uniform intervals during the toroid-like formation stage after the carcass ply is formed, resulting in excellent uniformity of the finished tire and smoothing of the uneven surface of the tire. Durability is further improved.

FIGS. 5 and 6 are schematic diagrams of the front and back surfaces of other knitted fabrics used in the radial tire of the present invention, respectively. In the figure, the knitted fabric (30) has warp threads (31) arranged parallel to each other, and weft threads (32) that intersect the warp threads at approximately right angles and are arranged roughly without being woven. By knitting these warp and weft yarns with fine fiber knitting yarns (33) along the longitudinal direction of the warp yarns, the warp yarns and weft yarns are integrated to form a knitted fabric. As for the knitting method here, conventionally widely adopted methods such as warp stockinette knitting or horizontal stockinette knitting can be adopted, but Raschel knitting is preferably adopted.

Various materials can be used for the warp threads, including organic fibers such as nylon, polyester, rayon, and aromatic polyamide, and inorganic fibers such as steel and glass fibers.

Further, the weft yarns are made of weft materials used in blind fabrics, but in the present invention there is no need to particularly select materials that suppress the movement of the weft yarns, and there is no need to particularly select materials that suppress the movement of the weft yarns. It only needs to have enough strength to not be cut by the tension up to the pulling process, for example, the strength after the adhesion process is 1. OOg/d or more. Furthermore, since the warp threads slip in plain weave, even long fibers, which are not often used, can be used in the present invention.

FIG. 7 shows another embodiment of the present invention. In the figure, knitted fabric (
In 40), the warp threads (41) are arranged parallel to each other, and the weft threads (42) are arranged roughly at right angles to the warp threads (41) without being woven.

The weft (42) is fixed to the warp (41) by intertwining silk threads along the longitudinal direction of each warp (41). In the embodiment shown in FIGS. 5 and 6, one knitting yarn is stretched between a plurality of warp threads to form a mesh, whereas in the embodiment shown in FIG. They differ in that they are entangled along one warp thread.

The knitted fabric obtained as described above is subjected to conventional adhesive treatment and heat treatment, followed by topping rubber treatment to form a ply with a structure in which silk cloth is embedded in the rubber, and used for the carcass of a radial tire. be done. Radial tires containing these plies have the following advantages:

(a) Because the warp and weft of silk cloth are fixed with knitting threads,
Through the carcass ply processing and molding process, the end distribution becomes uniform, improving the uniformity of the tire and improving its durability.

(b) Since the warp yarns are not woven with the weft yarns, the "folding surface" in blind fabrics is eliminated, and the ply thickness is thin and uniform, which is advantageous for reducing the weight of the tire and improving uniformity.

(c) Since the warp and weft are fixed with knitting yarns, thin long fibers can be used for the weft, and the spacing between the wefts can also be made coarser, which reduces the weight of the weft and reduces the processing cost of the weft, resulting in lighter tires. can be achieved.

(d) Since knitted fabrics are not woven, productivity is improved and the warp yarns do not shrink during weaving, making it possible to reduce material costs.

(e) In addition, in the case of a knitted fabric that does not contain weft yarns, the warp yarns of the knitted fabric are fixed by the knitting yarns so that they can expand and contract with each other, so the end distribution is uniform, improving the uniformity of the tire and improving durability. .

Example The tire size was 185/70R14, and the carcass was made of knitted fabrics and conventional blind fabrics with specifications shown in Table 1.
We prototyped the radial tire for passenger cars shown in the figure. Topping rubber gauge and fiber shrinkage of each knitted and woven ply;
The uniformity, durability, etc. of the prototype tires were evaluated.

(A) The topping rubber gauge has cord spacing (A) (B) between plies in the ply cross section shown in Figure 8 (A).
As shown in FIG. 8(B), the distance (C) between the cord and the adjacent different-phase rubber was measured. In conventional blind fabrics, the undulating width (W) of cords within the same ply is large due to the structure of the ``tatami table'', which inevitably results in a large topping rubber gauge.

(b) When the cord with the knitted fabric shrinkage length Lo becomes the length Ll when it is made into blind fabric or knitted fabric, the knitted fabric shrinkage is (c) Uniformity rim is assembled and the internal pressure is 1.9 kg/cn? The filled tire was pressed against the drum with a load of 404 kg, the tire and drum were rotated, and changes in stress in the horizontal and vertical directions with respect to the axle were measured and expressed as an index. The smaller the value, the better.

(d) Durability: Filled with internal pressure of 1.9 kg/cI11, load 63
A load of 1 kg was applied to the drum and the drum was run at 80 km/hr until damage occurred, and the distance traveled was converted into an index.

The larger the value, the better.

[Brief explanation of the drawing]

Figure 1 is the right half of the cross-sectional view of the tire, Figures 2 to 7 are schematic diagrams of the knitted fabric used in the tire of the present invention, Figure 8 (A),
FIG. 8(b) is a cross-sectional view of the braai, and FIG. 9 is a partially enlarged view of the tire bead portion. 1 Bead core 2.3 Carcass 4 - Bead apex 5 Belt layer 6 Tread portion 10.20.30.40 Knitted fabric 11.21.31.41'' Warp 32.42 Weft 13.14.23.24.33.34. 43 Knitting Yarn Patent Applicant Sumitomo Rubber Industries Co., Ltd. Agent Patent Attorney Yoshihira Nakamura Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 (A) Figure 8 (B) Figure 9

Claims (5)

[Claims] (1) A pair of left and right bead cores, a toroidal carcass that is secured by folding both ends around the bead cores, a belt layer in which cords are arranged at a shallow angle in the tire circumferential direction on the crown part of the carcass, and The carcass includes a tread portion disposed outside the belt layer, and the carcass is a ply made of a knitted fabric in which warp threads are aligned parallel to each other and at regular intervals, and the warp threads are knitted with braided yarns of fine fibers. , a radial tire characterized in that its warp threads are arranged substantially parallel to the tire radial direction. (2) Knitting yarn is polyester, nylon 6, nylon 66
The radial tire according to claim 1, which is an organic fiber filament of 5 to 80 denier. (3) The radial tire according to claim 1, wherein the knitted fabric has a cutting elongation in the width direction of 30% or more. (4) a pair of left and right bead cores, a toroidal carcass that is secured by folding both ends around the bead cores, a belt layer in which cords are arranged at a shallow angle in the tire circumferential direction on the crown portion of the carcass; The carcass includes a tread portion disposed on the outside of the belt layer, and the carcass has warp threads arranged parallel to each other and at regular intervals, and weft threads arranged approximately at right angles to the warp threads at coarse intervals without weaving. 1. A radial tire comprising a ply made of a knitted fabric in which warp and weft yarns are knitted with knitted yarns of fine fibers, and the warp yarns are arranged substantially parallel to the tire radial direction. (5) Knitting yarn is polyester, nylon, nylon 66
The radial tire according to claim 4, which is an organic fiber filament of 5 to 80 denier.