JPS5953205A - Belt layer for radial tire - Google Patents

Abstract

PURPOSE:To prevent the rigidity of a steel belt layer's edge part from dropping, by installing a textile cord layer, having a cord angle in a direction to cross the steel belt layer, on this steel belt layer so as to cause the cord angles of each layer to be crossed with each other. CONSTITUTION:A belt layer embedded in on top of a carcass layer of the lower part of a tread of a radial tire is set adjoiningly opposite to each of steel belt layers 1 and 2 and their upper parts and composed of each of textile cord layers 3a, 3b and 4 as an edge belt. At this time, these textile cord layers 3a and 3b are set up after making up an interval part at the center and dividing this interval into two parts. In addition, the width of the steel belt layer 2 is set to be narrower than the steel belt layer 1, and a steel cord SC of both layers 1 and 2 is installed so as to meet an angle range of 15-25 deg. to a tire equator surface and to be crossed with each other. Furthermore, a cord angle of a textile cord of both layers 3a and 3b is set to almost the same degree as the angle of the cord SC.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to an improvement in the belt layer of a radial tire, which is embedded in a reinforcing rubber band in the circumferential direction on the carcass layer at the bottom of the tread of the tire. Specifically, the purpose is to prevent a decrease in the number of ends at the edge portion of the steel belt layer, suppress a decrease in rigidity of the edge portion, and improve high-speed durability.

Conventionally, the belt layer of radial tires has been made of steel cord, or has an organic LLI fiber cord layer laminated on the steel belt layer with the intention of alleviating the difference in rigidity between the steel cord and the tread rubber. When it was decided to mold a drum-molded green tire into a toroid-shaped radial tire, the number of edges of the steel belt layer was reduced, reducing high-speed durability.

That is, when the belt layer of the tire is composed of two steel belt layers made of steel cords, or when an organic fiber cord layer is laminated on the steel belt layer in the circumferential direction at a cord angle of Oo with respect to the tire equatorial plane. In the case of a belt structure in which the number of ends of the steel cord in the belt layer is examined, the number of ends at the edge part is smaller than that at the center part, and therefore, the number of ends at the edge part is smaller than that at the center part. The rigidity was decreased.

In addition, in order to increase rigidity, in the method of distributing a circumferential organic fiber cord layer at a cord angle of 0° with respect to the tire equatorial plane on a steel belt m, the joint portion is formed by lap jointing, so the tire diameter There was a drawback that the uniformity of force deteriorated in the direction.

The name of the invention is ``-2 In order to eliminate the defect, at the ends of all steel bells, the organic fiber cord layer and the outer edge in the lateral direction are aligned, and each layer is aligned with the tire equatorial plane. Regarding the angle, by connecting the steel cord and the organic fiber cord to each other at almost the same angle, the change in the number of ends of the steel cord in the belt layer is unexpectedly suppressed. This is what constitutes this invention.In particular, in tire molding, both ends of the organic fiber cord layer and the steel belt layer are approximately on the same line, and the cords are formed in a cross shape. Is Rukoto.

In other words, the change in the number of ends of the steel cords of the belt layer is suppressed by causing the pantograph effect between the opposing cords to occur at the ends of the steel belt layer.

To begin with, the diameter of the belt layer formed on the drum of the tie V forming machine is somewhat smaller than the diameter of the single layer of belt I in the tie 1a formed into a toroidal shape. Therefore, the belt layer is
It extends in the circumferential direction from the top of the drum toward the end of vulcanization.

3- At this time, the angles that intersect with each other cause a phenomenon in which the cord angle becomes smaller and the width becomes narrower due to elongation in the circumferential direction, that is, a pantograph effect occurs.

Next, the structure of the belt layer of the present invention will be specifically explained in detail based on illustrative drawings.

Example-1, system configuration.

FIG. 1 shows an example of the implementation of this invention,
The combination of belt layers made up of rubberized cords circumferentially embedded in a carcass layer below the tread of a radial tire is shown in a plan view in which each layer is developed in a partially planar structure.

In the figure, 1.2 is a steel belt layer, and a part of it has textile layers 3a and 3 as edge belts.
b, 4 are in contact with each other, and the textile cord layer that is in contact with the steel belt layer 2 is of a system divided into two with a gap provided in the center. This second
The width of the steel belt layer 2 of the layer is narrower than the width of the steel belt layer 1 of the first layer, and is formed in a stepped shape. These steel cords SC of the steel belt layer 1.2 are arranged in an inclined shape with an intercolor range of 15 to 25 degrees with respect to the tire equatorial plane (hereinafter abbreviated as "-]-de angle"). They are set to intersect with each other at approximately the same angle. In addition, the ends of each layer of the steel belt layer are connected to textile layers 3a and 3, respectively.
b, 4 are provided in a state of opposition and their lateral outer ends are substantially colinear with each other, and the cord angle of the steel cord SC of the second layer steel belt layer 2 and the textile cord layer 3a, 3t) van code TC
The cord angles of are set in a cross-like manner to approximately the same extent.

Similarly, the textile cord layer 4 is set to intersect with the steel bell 1 of the first layer at approximately the same degree as the cord angle 1 of the layer 1, and the ends of both are approximately in the same line. It is set up like this. Therefore, if the inclination direction of the steel cord SC of the steel belt layer 1 of the first layer is upward to the right, the inclination directions of the cords of the four layers of the steel belt layer and the textile cord layer are sequentially upward to the left, upward to the right, and to the left. On the other hand, the steel cord of layer 1 of the first layer is
When the inclination direction of the SC is leftward, the cords of the adjacent layers are arranged in the opposite directions, such as upward to the right, upward to the left, and upward to the right, intersecting each other.

For the samples in Table 1, the cord angle of the cord layer 1.2 was set to 16°, and the textile cord layer 3a
, 3b, and 4 are made of nylon cord, and the textile cord layers 3a and 3b are made of 5 layers with a width of mm.

Example-2゜This example shows the second developed partial plan view of the belt layer according to the doctor.
As shown in the figure, there are 20 textile cords of steel belt layers in the cross structure of Figure 1 lil? It is the same as Example-1 except that the divided structure of t3a and t3b was changed to an undivided textile cord layer 3.

Example 3 In this example, as shown in FIG. 3, which is also a developed partial plan view, the textile cord layer 4 in FIG. -Do 4a,
The structure is the same as that of Example-2 except that it is configured as 4b.

Example 4 In this example, as shown in FIG. 4, which is also a developed partial plan view, a gap is provided in the center of both textile cord layers, and textile cord layers 3a, 311.4a, 4
It is the same as Example-1 except that b is configured.

For the embodiment of this invention written in F, FIG.
C, I) shows the structures of Comparative Examples A, , B, and C1D as comparative examples, which are shown as developed partial plan views of each layer of the belt layer as in the example.

Comparative example-8.

In this example, on the top of the steel belt layer 1.2 of the cross structure,
The fiber cord TC direction of the textile cord layers 5a and 5b (using nylon cord) is parallel to the tire equatorial plane, that is, the cord angle is 0°, and is set across both ends of the steel belt layer 1.2.

7- Comparative example-B.

In this example, the swivel bell eye 1.2 and the textile cord layer 4 have the same structure as in the example, and 38.3 in the example.
This is the same as in the example except that the textile cord layer +3a and (3b) are formed by extending the width of the layer b to the width of the steel belt layer 1.

That is, since the textile cord layers 6a and 6b extend to the outer edge of the first steel belt layer 1,
The cord direction is formed in the same direction as the cord direction of the end portion of the steel belt layer 1.

Comparative example - 〇.

In this example, the steel belt layer 1.2 and the textile cord layers 3a and 3b are the same as in Example-1, and the width of the textile cord layer 4 is narrowed, and the width of the 2mth steel belt layer 2 and the textile cord are A textile cord layer 7 is formed to match the ends of layers 3a and 3b. That is, the textile cord layer is omitted from the end of the first steel belt layer 1.

8- One comparative example.

In this example, the steel belt layers 1 and 2 and the textile cord layers 3a and 3b are the same as in Example-1, and the width of the textile cord layer 4 in Example-1 is extended to be larger than the width of the steel belt layer 1. An extension part e is provided. In this example, the extension part Q is 15 mm.

The configurations of the following Examples and Comparative Examples were manufactured into tires with an equatorial plane of 225/60R14, and comparative tests were conducted. The results are shown in Tables 1 and 2.

(See next page) Table 1 (Note) R[\l...The difference in the non-uniformity of the force in the radial direction of the tire is k
Measured in g, its mean value (also) and its standard deviation (σ)
This is what is shown.

High-speed durability...This measurement method is based on the U.S. U.T.Q.G.
(UNIFORM TIRE QUALITY
This was done in accordance with the regulations of GRADING 5 TANDARD>.

Load 5431, tire pressure 1.7kg/cn? -80
,5km/h -120 minutes, tire pressure 2.1kQ
/cn (-120,7km/h -30 minutes, thereafter 8
Drive for 30 minutes at every km/h limit until an abnormality occurs.

(Next page below) 11-12- Note: High load durability...tire pressure 1.7 = a/cn?
, speed 80.5km/h 1 load 509kg -4
Time, 539 = 3-24 hours, 599 = 3-24 hours, and after that, with a load of 8381, the total mileage was 12000kl + 1. Observe the condition.

As shown in Tables 1 and 2 above, in Comparative Example-A, the textile cord layer's =1-de direction is Oo, so the joints in the circumferential direction need to be overlapped, and the joints in the radial direction need to be overlapped. The uniformity of force is poor.

As a result of a comparative test of high-speed durability, it was found that the steel belt layer and the textile cord layer need to be formed with the cord directions intersecting, and the outer ends must be formed so that they operate correspondingly on the same line. Therefore, it is necessary to form them so that they are evenly aligned.

In addition, the belt layer configuration with only two steel belt layers or the configuration in which a textile cord layer with a cord angle of 06 is placed on top of the belt layer has a smaller number of ends at the lateral ends of the steel belt layer than the ends at the center. It's getting smaller.
This indicates that the rigidity of the ends is lower than that of the center.

As shown in the examples, the belt layer of the present invention is an edge belt in which a textile cord layer having a similar cord angle in a direction crossing the steel belt layer is arranged at the edge portion in the lateral direction of the steel belt layer. Due to the pantograph effect, the number of ends of the steel cord at the edge of the steel belt layer is prevented from decreasing, the rigidity of the edge of the steel belt layer is prevented from decreasing, and high-speed durability is improved. It is.

[Brief explanation of the drawing]

FIG. 1 is a partially developed plan view of each layer of the bell 1 layer of the radial tire of the present invention. FIGS. 2 to 4 are partially developed plan views of each layer showing embodiments of the belt layer of the present invention. , FIG. 5-A, B, C, [) are partial plan views of each layer of the comparative example. 1.2...Steel belt layer 3.3a, 3b, 4.4. a , 41)-r*')
, Tar(ru)-do layer SC...Steel cord TC...[1 Code agent Patent attorney Yasushi Oshima Ame 15- Figure 3 Figure 4 Figure 16- 1. Indication of the incident 1988 Patent Application No. 16528 May 2, Title of invention: Belt layer 3 of radial tire, Relationship with the amended case Special W [Applicant No. 17-18, 11-1, Edobori, Nishi-ku, Osaka-shi, Osaka (314)
Toyo Rubber T-Gyo Co., Ltd. 1 Representative Masamaki Okazaki 4, Agent Yu 5! i0 1-1-125-30 Edobori, Nishi-ku, Osaka
Therefore, the Detailed Description of the Invention column of the amended counter-shelf specification should extend beyond the edge and be within 5 mm. 6. Contents of amendment (1) Page 6, line 11 of the specification [The angles are set to be approximately the same in a cross shape. ] is corrected as follows. [It is preferable to set the cord angles to be equal to each other in a cross shape, but the cord angles of the textile cord layers 3a and 3b may differ by up to ±5 degrees from the cord angle of the steel belt layer 2. The offsets of the lateral outer ends of the textile cord layers 3a and 3b with respect to the end of the steel belt layer 2 are set within ±3n+m so that they are substantially on the same line. (2) On page 6, lines 13 to 14 [Set in a cross shape at approximately the same degree as the chord angle, 1 is corrected to the following J: sea urchin. [It is /2 to set it in a cross shape with the cord angle equal to
7. Preferably, the cord angle of the textile cord layer 4 may have a difference of ±5 degrees from the cord angle of the steel belt layer 1, and the end of the textile cord layer 4 may overlap the end of the steel belt layer 1. 1 (3) Change "High-side durability (UTQG regulations)" in the tire performance column of Table 1 on page 11 to "High-speed durability (UTQG regulations)". Corrected as 1.

Claims (1)

[Claims] (1) In the belt layer of a radial tire, which is embedded in a reinforcing rubber strip in the circumferential direction on the carcass layer at the bottom of the tread of the tire, a first steel belt layer is placed on the first steel belt layer. The second steel belt layer, which is narrower than the steel belt layer, is oriented in a crosswise manner in the opposite direction, and the J cord angle of the steel cord of this steel belt layer with the tire equatorial plane is 15.
~25°, and the third textile layer set on the second steel belt layer has approximately the same width as the second steel belt layer, or Alternatively, it is divided into two parts with an interval in the center, and the cord angle is set at approximately the same angle in the opposite direction to that of the second layer, and in either case, the outer ends of the widths of the second and third layers are approximately the same. The fourth layer, which is set on the same line as the third layer, is made of the same textile layer, and its cord angle is set at almost the same angle in the opposite direction as the third layer. Either the width of the 11th textile cord layer is approximately the same as the width of the 1st layer steel belt layer, or it is divided into two parts with a gap in the center. A belt layer for a radial tire characterized by the above-mentioned configuration in which the outer ends of the widths of the four layers are arranged in a substantially same line.