JPH03148306A - Pneumatic tire - Google Patents

Abstract

PURPOSE:To effectively reinforce a belt throughout an entire width and to improve durability by providing a central portion reinforcing layer consisting of a bias cord reinforcing material which has an angle with respect to the circumferential direction of a tire between edge portion reinforcing layers extending along both sides of a belt ply. CONSTITUTION:In a tire T, a belt ply 1 is provided between the top portion of a carcass ply 2 and a tread portion 3. A belt reinforcing layer 10 is disposed along the outer side of the belt ply 1. In this case, the belt reinforcing layer 10 is constituted of edge portion reinforcing layersill arranged on the outer side of edges at both sides of the belt ply 1 and a central portion reinforcing layer 12 disposed between the end edge portion reinforcing layers 11 at both sides. Then, the edge portion reinforcing layers 11 are formed by winding a relatively narrow, belt shaped, fiber reinforcing material with relatively small number of driven cords in the circumferential direction of the tire. The central portion reinforcing layer 12 is formed by winding proper number of bias cord reinforcing layers of relatively large width, with a prescribed angle in the circumferential direction of the tire.

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a pneumatic tire for a passenger car, in which a belt reinforcing layer is provided along the outside of a belt braai between the top of the carcass and the tread. [Prior Art] Several layers of cord called a belt are arranged at the top of the carcass ply and at the bottom of the tread of a passenger car tire, and this belt is made of various industrial fibers such as nylon and polyester fibers or steel cord. Consisting of In this belt structure, a so-called belt reinforcing layer made of fiber cords is generally provided on the outside of the belt ply for the purpose of suppressing separation at the edge portions on both sides of the belt ply and improving high-speed durability. Another way to form this reinforcing layer is to wrap a reinforcing auxiliary belt made of a relatively wide fiber cord around the outside of the belt bra, but in this case, the auxiliary belt overlaps the reinforcing layer itself. A joint is created by splicing. In particular, in anticipation of shrinkage during vulcanization, this joint is made relatively thick. Therefore, not only the joint of the belt ply but also the joint of this auxiliary belt are present on the circumference of the tire, which results in a decrease in tire uniformity. Therefore, during tire molding (green tire molding), a relatively narrow band-shaped fiber reinforcement material with a cord count of 10 or less is placed on the molding drum at a substantially zero width in the circumferential direction.
A method has been considered in which the belt is wound continuously while rotating the drum at an angle of
b] There is a method shown in (c). In [a] of the same figure, two reinforcing layers (1
0a), and (b) in the same figure has two reinforcing layers (job) in the edge part and one reinforcing layer (job) in the center part between them. Two reinforcing layers (FOE) are continuously provided over the entire width of the ply. [Problems to be Solved by the Invention] However, in the case of the belt reinforcing layer in [a] above, although the time required for wrapping and molding this reinforcing layer is short, it is not durable when cut in hot and humid areas or on rough roads. It is disadvantageous to sex. In other words, the belt reinforcing layer exists only at the edges on both sides of the belt, and there is no reinforcing layer between the belt ply and the tread rubber in the center, so the tread is scratched when the tire steps on stones or metal. If this happens, the scratches will reach the belt, and especially if it is a steel cord belt, it will rust and reduce its durability. In addition, in the case of the belt reinforcing layer in [b] and (c), although the above-mentioned problems are unlikely to occur, the time required for winding and forming this reinforcing layer is approximately 50% or more compared to the case in [a]. It will also cost a lot of money. In view of the above, in the present invention, the belt reinforcing layer provided along the outside of the belt ply can be reinforced by waving over the entire width of the belt ply, thereby improving high-speed durability and TLC performance (performance against separation between carcust and red). ),
Moreover, the present invention provides a pneumatic tire that requires less time for wrapping and molding, does not have a joint portion due to lap joints, and can improve the uniformity of the tire. [Means for Solving the Problems] The present invention provides a pneumatic tire in which a belt ply is arranged between the top of a carcass ply and a tread portion, and a belt reinforcing layer is provided along the outside of the belt ply. hand,
In particular, in order to solve the above-mentioned problems, edge reinforcement is made by wrapping narrow fiber reinforcing material in the circumferential direction of the tire with a relatively small number of reinforcing strips on the outside of the edge portions on both sides of the belt ply as a belt reinforcement layer. An angled center reinforcing layer is provided between the edge reinforcing layers on both sides by a bias cord layer having a required angle with respect to the circumferential direction of the tire. The central reinforcing layer preferably has a cord angle of 10° to 45° with respect to the tire circumferential direction.

[Made by Kawa]

The above-mentioned tire of the present invention has an edge reinforcing layer made of a relatively narrow band-shaped fiber reinforcing material wrapped in the circumferential direction of the tire on the outer side of the edge portion on both sides of the belt ply, and between the edge reinforcing layers on both sides. The belt has a center reinforcing layer made of bias cord reinforcing material, and the belt reinforcing layer spans the entire width of the belt, so even if the tread rubber gets scratched by stepping on a pebble or metal piece, the scratch will be removed from the belt ply. This prevents rust from forming even on steel belts. Furthermore, the edge reinforcing layers on both sides of the belt ply can prevent separation of the edges during high-speed running, and can also reduce the number of joints in the belt ply. In particular, since the central reinforcing layer is made of a bias cord reinforcing material that has a required angle with respect to the tire circumferential direction, it can be easily wrapped in the same way as belt ply, and the joints between the ends can be easily wrapped. Also in the section, the cord angle can be used to join the cords to a butt state with substantially no overlap. Therefore, even though the reinforcing layer covers the entire width of the belt, there is no risk of deteriorating the uniformity of a tire that has a joint portion due to lap joints. [Example] Next, an example of the present invention will be described based on the drawings. Figure 1 shows the cross-sectional structure of the tire (T). It consists of cords made of industrial fibers or steel cords, and is usually laminated in multiple layers. (lO) is a belt reinforcing layer provided along the outside of the belt ply (1). The belt reinforcing layer (10) includes an edge reinforcing layer (11) placed on the outside of the edge portions on both sides of the belt ply (1), and a center reinforcing layer (11) placed between the edge reinforcing layers (11) on both sides of the belt ply (11). It is composed of a reinforcing layer (12). The edge reinforcing layers (!l) on both sides are made of relatively narrow strip-shaped fiber reinforcing material (l) in which the number of cords is, for example, 10 or less.
la) are continuously wound in two layers at an angle of substantially 0 to the tire circumferential direction, and the central reinforcing layer (12) is wound at an angle of substantially 0 to the tire circumferential direction, as shown in Fig. 3. A relatively wide bias cord reinforcement with the required angle (α) is
WI or wrapped in several layers. The cord angle (a) of the angled central reinforcing layer (12) with respect to the tire circumferential direction is preferably in the range of 10@ to 45 degrees. This angled central reinforcement layer (12
) in two or more layers, it is preferable that the cord directions be alternately inclined in opposite directions for each layer. When molding the belt reinforcing layer (10), first place the center reinforcing layer (12) on the belt ply (1) during tire molding.
The bias cord reinforcing material is wrapped in one to several layers. At this time, the ends of the bias cord reinforcing material can be joined to each other in a substantially non-overlapping state using the cord direction, and there is no risk of deteriorating the uniformity of the tire. Then, a narrow strip-shaped fiber reinforcing material (lla), which will become the edge reinforcing layer (11), is started wrapping over the side end of the central reinforcing layer (12) located slightly inward of the belt edge. Wrap it several times outwards to form the first layer.
Further, it is folded inward and wound in layers to form two layers. This edge reinforcing layer (11) can reinforce the belt edge and prevent separation during high speed running. By wrapping the edge reinforcing layers (11) over both ends of the angled central reinforcing layer (12) as described above, the joints at the ends of the central reinforcing layer (12) are It can be done for real value. According to the belt reinforcing layer (10), the edge reinforcing layer (11) (11) and the angled central reinforcing layer (12) cover and reinforce the belt ply (1) over its entire width. Even if the tread part (3) is scratched by stepping on a pebble or metal piece, the reinforcing layer (10) can prevent the scratch from reaching the belt ply (2), even if the belt is made of steel. Prevents rust from forming and improves high-speed durability and TLC performance. In addition, even though the belt is reinforced over the entire width, the angled central reinforcing tank layer (12) can be wrapped and arranged in the same way as the belt ply, so a narrow strip of reinforcing material can be applied over the entire width of the belt. Figure 4 (C) Wrapping the forming drum one by one while rotating
The molding time can be significantly shortened compared to the case of . - As an example of the present invention, a belt reinforcing layer has one angled central reinforcing layer (12) made of bias cord reinforcing material and two layers of edge part reinforcing layers (11) (11) made of band-like fiber reinforcing material. When implemented with the structure of (10) and the 41st
Among the conventional methods shown in 1, a case in which a belt reinforcing layer is provided only at the edge part (Figure [a]) and a case in which a belt reinforcing layer is wound in two layers over the entire width (Figure [C]) Regarding molding time, uniformity, high speed durability and TL
A comparison of C performance is shown in Table ii below. However, the tire size is 225150 V RlB, and the structural conditions of each part of the tire other than the belt reinforcing layer are the same. Here, 11 during molding is the time required for winding and molding only the belt reinforcing layer, and 11 is the time required for winding and molding only the belt reinforcing layer, and 10
Displayed as an index as 0. 1FV is an automobile standard established by the Society of Automotive Engineers of Japan, JASOC8.
This data is based on the 07 automobile tire uniformity test method, where a load is applied to the tire, the distance between the axes of the tire and the test drum is kept constant, and the tire is rotated in the forward and reverse directions. Measure the tire radial force (reaction force) and its variation (maximum and minimum difference)
RF V (Radlal Force Varia)
tlon). Regarding high-speed durability, European Economic Commission Regulation 30
The test was conducted in accordance with the conditions for tires with speed symbol V specified as the load/speed performance test procedure in the supplementary provisions. At the specified speed (230 km/h) and time conditions, no failures were observed and the test was passed, so an additional 109
Increase the speed by 10 km/h and continue to run the drum until it breaks down, and then show the speed of the bird and the time at that speed. In the TLC (actual vehicle) test, the vehicle was disassembled and inspected after 20,000 miles to check for belt failure. 6 Inventive product Comparative example Comparative example Fig. 4 [a
] Figure 4 (cl Hot molding time l 50 l 41.7 l
100 lI High Speed Durability Heat I
IIl (Actual vehicle) I l-With sillion [l As is clear from the above test results, in the case of the present invention, although the belt reinforcing layer spans the entire width of the belt, the reinforcing layer itself is formed during molding. E is reduced by half compared to the conventional full-width system, which is not much different than when a reinforcing layer is provided only at the edge, and the uniformity of the tire is also improved compared to conventional products. It was also found that high-speed durability was comparable to conventional products, and TLC performance was particularly excellent. [Effects of the Invention] As described above, the present invention provides, as a belt reinforcing layer, one or more layers of bias cord reinforcing material forming a required angle with respect to the tire circumferential direction between the edge reinforcing layers along both sides of the belt bra. By providing an angled central reinforcing layer, it is possible to reinforce the entire width of the belt, eliminating the risk of separation at the belt edge.Not only does it have excellent high-speed durability and TLC performance, but it also has a reinforcing layer that waves across the entire width of the belt. However, the molding time can be significantly shortened. In particular, since the angled central reinforcing layer can be jointed in abutting state with no substantial overlap using the cord direction, tire uniformity is also improved.

[Brief explanation of the drawing]

Fig. 1 is a half cross-sectional view of a tire showing an embodiment of the present invention, Fig. 2 is a schematic cross-sectional view illustrating the layer structure of a belt and a belt reinforcing layer, and Fig. 3 is a state in which the belt reinforcing layers are superimposed. FIG. 4 Cal [b] (cl is a schematic cross-sectional view illustrating the layer structure of a conventional belt reinforcing layer. (1)...Belt ply, (10) -... Belt reinforcement layer, (11)... Edge reinforcement layer, (12)... Angled center reinforcement layer. Patent applicant: Toyo Rubber Industries, Ltd. Figure 1 9 T, 4121, 1 f Figure 2 (t (

Claims (1)

[Claims] 1. A pneumatic tire in which a belt ply is arranged between the top of the carcass ply and the tread portion, and a belt reinforcing layer is provided along the outside of the belt, the belt reinforcing layer As such, an edge reinforcing layer is provided on the outside of the edge portions on both sides of the belt ply, and the edge reinforcing layer is made by wrapping narrow fiber reinforcing material in the tire circumferential direction with a relatively small number of implants, and between the edge reinforcing layers on both sides, A pneumatic tire characterized by having an angled central reinforcing layer made of bias cord reinforcing material having a required angle with respect to the tire circumferential direction. 2. The pneumatic tire according to claim 1, wherein the cord angle of the angled central reinforcing layer is 10° to 45° with respect to the tire circumferential direction.