JPS59195406A - Pneumatic radial tire for car - Google Patents

Abstract

PURPOSE:To prevent a fault at vulcanization and improve uniformity and productivity by forming the end of inner liner periphery of a tubeless radial tire and the start point of periphery of a carcass layer in abutting configuration. CONSTITUTION:The end 12 of tire periphery of an inner liner 10 and the start point 41 of tire periphery of a carcass layer 4 are butted together instead of being overlapped. On the other hand, the end of periphery of the carcass layer 4 is arranged so as to crossover the splice section 10a and abutting section T of the inner liner 10. As a result, no air sump occurs between the end 12 of tire periphery of the splice section 10a of the inner liner 10 and the carcass layer 4. Consequently, a fault can be prevented at vulcanization and uniformity can be improved without requiring any stitcher. Especially, both LFV and productivity can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to pneumatic radial tires for passenger cars, and more particularly to improvements in pneumatic tubeless radial tires for passenger cars.

At the time when pneumatic radial ties for passenger cars appeared, in order to maintain the internal pressure of the tire, a tube made of rubber with relatively low air permeability was inserted inside the tire to maintain the internal pressure of the tire. was in charge of the functions of

However, since then, a technology has been developed to integrate this tube with a tire, and pneumatic radial tires for passenger cars now have a tubeless structure.

However, the inner liner of this tubeless tire generally contains a large amount of butyl rubber to improve air permeation resistance, so if air pockets occur between the carcass layer and the inner liner during tire molding work, It is known that this remains as it is and tends to cause vulcanization failure.

Therefore, in order to solve this problem, conventionally, as shown in FIG. 1, when molding a tire, the splice portion 10a of the inner liner 10 and the splice portion 4a of the carcass N4 are shifted from each other. This prevents a large air pocket C from being generated due to a large step difference that occurs when the splice portion 10a of the inner liner 10 and the splice portion 4a of the carcass layer 4 are aligned and molded as shown in the figure.

However, even if this measure is taken, as shown in FIG. could not.

Since the occurrence of this air pocket A is a major cause of the above-mentioned vulcanization failure, at present, a stitcher is applied to remove the air pocket A as shown in FIG. 1 during tire molding.

However, the current situation is that the use of a stitcher as described above causes the following new problems. In other words, (the weft threads for maintaining the uniformity of each cord in the al carcass layer are cut, and as a result, the ends of the carcass cords are disordered during tie 4 and vulcanization. The shear uniformity, especially lateral force variation (hereinafter referred to as "'") This not only worsens FLF (also referred to as FLF), but also causes unevenness in the tire sidewall portion during tire inflation, causing poor appearance of the product tire.

fb) When molding a tire, the work of shifting the splice portion of the inner liner and the splice portion of the carcass layer, running the stitcher and removing the air pocket A significantly impedes productivity.

(C) If an unvulcanized tire with stitches is left unused due to a malfunction of the tire vulcanizer or the like, the stitcher rift will be diluted over time.

The present invention was developed as a result of experimental studies to solve the above-mentioned problems.
It was guided.

Therefore, an object of the present invention is to prevent vulcanization failures during tire vulcanization by devising the relationship between the end of the inner liner in the tire circumferential direction and the starting end of at least one of the carcass layers in the diamond circumferential direction. Another object of the present invention is to provide a pneumatic radial tire for a passenger car, which has improved uniformity, especially LFV, and can improve the productivity of tire molding.

That is, the present invention has an inner liner on the inner surface of the tire extending from the pair of left and right heat parts to the sidewall part and the tread part, and the tire is positioned outside the inner liner and between the pair of left and right heat parts. A carcass layer having a cord angle of substantially 90° with respect to the circumferential direction is mounted, and a plurality of belt layers intersect with each other at a cord angle of 10' to 30'' with respect to the tire circumferential direction on the carcass layer in the tread portion. A pneumatic radial tire for a passenger car, characterized in that a peripheral end of the inner liner and a starting end of at least one of the carcass layers in the tire circumferential direction are butted against each other. The summary is as follows.

Hereinafter, the present invention will be specifically described by way of examples with reference to the drawings.

4 to 6 show pneumatic radial tires for passenger cars according to embodiments of the present invention, FIG. 4 is a partially cutaway perspective explanatory view, and FIG. 5 is a first embodiment, that is, a carcass layer. Fig. 6 (al~
(d) shows the second embodiment, that is, the carcass layer 21-
It is an explanatory front view of principal parts when arranged.

In the figure, E denotes a small passenger pneumatic radial tire according to the present invention, in which an inner liner 1o is arranged on the inner surface from a pair of left and right heat parts 1 to a sidewall part 2 and a tread part 3. the pair of left and right beads gI located outside the inner liner 1o;
A carcass layer 4 in which the angle of the cord 4a with respect to the tire circumferential direction is substantially 190° is mounted between the ties 1 and 1, and a carcass layer 4 in which the angle of the cord 5a with respect to the tire circumferential direction is substantially 190° is mounted on the carcass layer 4 in the trend portion 3. A plurality of gult layers 5 intersecting each other at 10'' to 30' are disposed, and furthermore, in the present invention, in particular, the tire circumferential end 12 of the inner liner 10 and at least one layer of the carcass layer 4 are arranged. It is constructed by abutting the circumferential starting end 41.

To explain this structure in more detail, the first
The embodiment is an example in which the carcass N4 is further arranged on the outside of the inner liner 10, and the tire circumferential end 12 of the inner liner 10 and the tire circumferential starting end 4I of the carcass layer 4 are overlapped as shown in the figure. On the other hand, the end 42 of the carcass layer 4 in the tire circumferential direction is arranged to extend beyond the splice portion 10a of the inner liner 10 and the butt portion T to cover these.

As described above, in this embodiment, the end 12 of the inner liner 10 in the tire circumferential direction and the starting end 41 of the carcass layer 4 in the tire circumferential direction are butted together without overlapping, so that the inner liner 10 and the tire circumferential direction start end 41 are butted together without being overlapped. , tire circumferential direction cotton of splice portion 10a in inner liner 1off
Air pockets A are not generated between the 1At 12 and the carcass layer 4. Therefore, it is possible to prevent vulcanization failure during tie 4 and vulcanization, and also to
Uniformity, especially L F
Not only can you improve V, but also reduce tire inflation.
It is possible to prevent unevenness from occurring on the tire sidewall portion at a time, and to improve the productivity of tire molding.

Furthermore, in this embodiment, the tire circumferential end 42 of the carcass layer 4 is arranged to extend over and cover the splice part 10a and the notch part T of the inner liner 10, so that the splice part Separation failures at the abutting portion 10a and the butt-u portion 'r' can be prevented.

Next, in the second embodiment, there are two carcass layers on the outside of the inner liner 10.
This is an example in which an inner carcass layer 4d and an outer carcass layer 4u are arranged.

FIG. 6 (In the case of AL, the tire circumferential direction end 12 of the inner liner 10 and the tire circumferential direction start end 41d of the inner carcass layer 4d are butted together without overlapping as shown in the figure, while the inner carcass layer 4d end 42d
is arranged to cover the splice part 10a and the butt part Td of the inner liner, and furthermore, the terminal end 42d of the inner carcass N4d and the starting end 41u in the tire circumferential direction of the outer carcass layer 4u are arranged as shown in the figure. This outer carcass layer 4 is butted without overlapping as in
The terminal end 42u of u is arranged to extend beyond and cover the abutting portion Tu.

In the case of FIG. 6(kl), the end 12 of the inner liner 10 in the tire circumferential direction and the starting end 41d of the inner carcass layer 4d in the tire circumferential direction are butted together without overlapping as shown in the figure, while End 4 of the carcass Fm4d
2d is arranged so as to cover the splice part 10a and the abutting part '1'd of the inner liner, and furthermore, the terminal end 42d of the carcass lm4d of the inner liner,
The starting end 41u in the tire circumferential direction of the outer carcass I>j4u is arranged to face each other with an interval as shown in the figure, and the terminal end 42u of the outer carcass layer 4u is opposite to the starting end 41u of the outer carcass I>j4u.
It is arranged so as to extend beyond and cover u.

Therefore, the starting end 41 in the tire circumferential direction of the outer carcass layer 4u
As shown in the figure, a small air pocket 13 is formed between the starting end 41u and the outer carcass layer 4u arranged to cover this starting end 41u. As such, it will not have a negative effect on the tires.

6 fc) and fdl, an inner carcass layer 4d is bonded to the outer side of the inner liner 10 in advance, and an end 42d of the inner carcass layer 4d in the tire circumferential direction and a starting end of the outer carcass layer 4u in the tire circumferential direction. 41u are butted against each other without overlapping as shown in the figure, and the terminal end 42u of this outer carcass IM4u is arranged so as to extend beyond and cover the starting end 41u.

Note that 20 in the figure is an extremely thin inner liner disposed inside the inner liner 10.

Of course, in the case of the second embodiment described above, the same effects as in the first embodiment described above can be obtained.

In addition, in the above-mentioned molding process of the present invention, if the abutting part between the tire circumferential end of the inner liner and the tire circumferential start end of the carcass layer is pressed together with the splice part of the Zyto wall member, the tire molding process can be completed. In the middle, the abutted portion does not peel off.

Next, the present invention will be explained in detail using experimental examples.

Example This experiment was conducted using a conventional tire shown in FIG. 1, a comparative tire shown in FIG. 2, and an inventive tire (first example) shown in FIG.
When we compared the occurrence of air puddle failure for each tire, we obtained the results shown in Table 1 (4
It's 1.

However, the failure in the tire of the present invention occurred not during the forming process but at the splice part during the cutting process.

As is clear from Table 1, in the tire of the present invention, unlike the conventional tire shown in FIG. It never happens.

Therefore, it can be seen that vulcanization failures that occur during tire vulcanization can be prevented.

Example In this experiment, the conventional tie-1 (carcass layer 1) shown in Fig. 1 was used.
layer), the comparative tire shown in FIG. 2, the conventional tire (carcass JW 2 layers) shown in FIG. 3, and the invention tire shown in FIG. 5 (first example (carcass layer IJN)), FIG. f
Tire of the present invention shown in bl [Second Example (Car force layer 2N)
)], and for each tire, LFV,
Uniformity test method for automobile tires JAsOC
Measured according to 607. The results were as shown in FIG.

As is clear from FIG. 7, the tire of the present invention (first embodiment (11 carcass layers)) shown in FIG. 5 is different from the conventional tire (one carcass layer) shown in FIG. In comparison with the comparative example tire, the present invention tire shown in FIG. 6(b) [Example 2 (two carcass layers)] was compared with the conventional tire (two carcass layers) shown in FIG. It can be seen that the LFV is improved in both cases.

In this way, as described above, in the case of the present invention, no air pocket A is generated between the end 12 of the splice portion 10a in the inner liner 10 in the tire circumferential direction and the carcass layer 4, and therefore it is not necessary to apply a stitcher. There is no.

As a result, the end disturbance of the carcass cord does not occur during tire vulcanization.

Example This experiment was carried out using conventional tie-1 (carcass N1) shown in Fig. 1.
layer), the comparative tire shown in FIG. 2, the conventional tire (carcass layer 21W) shown in FIG. 13, and the invention tire shown in FIG. 5 [1st Example (1 carcass layer)], FIG. b
) [Example 2 (two carcass layers)]
] was molded, and the unevenness of the tire sidewall portion of each tire was measured.

Note that the unevenness of the tire sidewall is determined by the JASOC
607, this unevenness at the tire maximum width position was detected and measured using a differential transformer.

The results were as shown in FIG.

As is clear from FIG. 8, the tires of the present invention shown in FIG. 5 [first embodiment (carcass I view NWj)] and FIG.
Tire of the present invention shown in Fig. 1 [Example 2 (two carcass layers)]
] are the conventional tire (with one carcass layer) shown in No. 1, the comparative tire shown in FIG. 2, and the conventional tire (with one carcass layer) shown in FIG.
It can be seen that the unevenness that occurs in the tire sidewalls has been improved in both cases compared to the carcass 1'421m.

This is because, as described above, in the case of the present invention, no air pocket A is generated between the end 12 of the splice portion 10a in the inner liner 10 in the tire circumferential direction and the carcass layer 4, and therefore it is not necessary to apply a stitch. There is no. As a result, when the tire is cured, 6. This is because the end disorder of the carcass cord does not occur in the second case.

In each of the above-mentioned experimental examples, the present invention tire shown in FIG. 5 [first example (carcass layer IN)], the conventional tire shown in FIG. 1 (one carcass layer), and the comparative example shown in FIG. The tire used in the tire was 155SR13, and the tire of the present invention shown in FIG. /70HR14 was used.

Since the present invention is configured as described above, there is no chance of air pockets A occurring between the tire circumferential end of the inner liner and the carcass layer. Therefore, (a) vulcanization failures during tire vulcanization can be prevented.

(b) There is no need to use a stitcher. As a result, it is possible to prevent the cutting of the weft threads that maintain the uniformity of each cord in the carcass layer, and there is no disturbance of the ends of the carcass cords during tie-1 and vulcanization, resulting in uniformity, especially in lateral force variations. In addition to preventing the deterioration of tire inflation, it can also prevent unevenness from occurring on the tire sidewall when the tire is inflated to 1.0 mm, and it can also prevent the appearance of product tires from becoming defective, and it can significantly improve productivity. can.

[Brief explanation of the drawing]

Figures 1 to 3 respectively show conventional pneumatic radial tires for passenger cars. Figures 1 and 2 are front views of main parts when a single carcass layer is arranged, and Figure 3 is a carcass layer. FIG. 2 is a front view explanatory diagram of main parts when two layers are arranged. 4 to 6 show pneumatic radial tires for passenger cars according to embodiments of the present invention. FIG. 4 is a partially cutaway perspective view, and FIG. 5 is a carcass tire according to the first embodiment. 1
Figure 6 (a)
l~(d+ is a front view explanatory view of the main part of the second embodiment, that is, when two carcass layers are arranged, and FIGS. 7 to 8 are diagrams showing the results of experiments. 1... Bead Part 2... Sidewall part 3... Trend part 4... Carcass layer 5... Belt layer 10... Inner liner

Claims (1)

[Claims] The inner surface of the tire has an inner liner extending from the pair of left and right bead portions to the sidewall portion and the tread portion, and the cord angle with respect to the tire circumferential direction is located outside of this inner liner and between the pair of left and right bead portions. A passenger car is equipped with a carcass layer in which the angle is substantially 90 degrees, and a plurality of layers of bells 1 are disposed on the carcass layer in the tread portion, intersecting each other at cord angles of 10 degrees to 30 degrees with respect to the tire circumferential direction. 1. A pneumatic radial tire for passenger cars, characterized in that a peripheral end of the inner liner and a starting end of at least one of the carcass layers in the tire circumferential direction are butted against each other.