JPS59106304A - Pneumatic safety tire - Google Patents

Abstract

PURPOSE:To make improvements in lasting quality in time of run flat running, by remedying both of an arrangement position for a reinforcing rubber layer and a cord tilt angle in a carcass layer to be arranged at the side of a tire, while devising the thickness of a rubber layer at the radial inside of the carcass layer in terms of design. CONSTITUTION:A butting outward in the radial direction of a bead core 8 in a symmetrical pair of bead parts 1, a reinforcing rubber layer 10 is arranged in position in a range reaching an end lower part 7a of a belt layer 7 between an outer part 7a of a belt layer 7 and a tread part 3 and that in such a part as interposed between an inside carcass layer 5 and the outside carcass layer 6. In addition, a cord tilt angle in the inside carcass layer 5 of this reinforcing rubber layer 10 is set down to a range of less than 80 deg. to the tire peripheral direction at a sidewall part 2. Moreover, the thickness (t) of a rubber layer 9 existing in the radial inside of the inside carcass layer 5 is set to the range of 15-30% of total thickness T in the radial direction in a range from at least the sidewall part 2 through a shoulder part 4.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pneumatic safety tire, and more particularly:
This invention relates to a pneumatic safety tire in which the tire structure from the bead to the sidewall has been improved in order to improve the running durability during Run 7 Lasoto running.

Generally, when a passenger car tire tries to run with zero air pressure due to a puncture, etc., the sidewall part bends significantly, causing the tire to collapse completely, causing cord breakage in the carcass layer due to buckling at the bend, and damage to the carcass layer. This causes damage to the inner surface due to friction and heat generation on the inner surface, and damage from the outer surface due to the rim 7 run. For this reason, driving with a flat tire will quickly damage the tire and make it impossible to drive.

Therefore, as one of the conventional countermeasures, a reinforcing rubber layer was placed between the carcass layers from the left and right sidewall parts to part of the shoulder, → reinforcing and strengthening the nod wall part,
Means for reducing the sagging of the sidewall portion during run-flat driving has been proposed.

For example, as seen in Japanese Patent Publication No. 52-49603, it is known that it is a shame to divide and arrange the reinforcing layer inside the carcass layer, between the carcass layers, or both.

However, if the reinforcing rubber layer is placed only on the inside of the carcass layer, the carcass layer and rubber layer will be separated, resulting in continuous deformation due to deflection during run-flat, resulting in poor durability. There are some problems with this. In addition, if it is arranged separately between the carcass layers and inside the carcass layer, discontinuities will occur in the stress distribution l from the bead part to a part of the shoulder. Furthermore, due to division, the number of constituent materials increases, and each layer
．． rll and +j problems such as ljJ peeling and poor adhesion also increase. On the other hand, if the hood is placed continuously between the carcass layers from the bead part to a part of the shoulder, the disadvantages mentioned in 1-1 will be reduced, but the following problems regarding the durability of the carcass hood will remain. .

In other words, when the reinforcing rubber layer is placed between the carcass layers, run flat running occurs): At the bent part of the sidewall part, compressive stress is applied to the inside of the reinforcing rubber layer, and tensile stress is applied to the outside. Due to the characteristics of carcass cords, which are generally weak against compressive stress, run-flat running had the disadvantage that the cords in the inner carcass layer would break during the female stage.

In order to compensate for this shortcoming, if we try to increase the rigidity of the 41 rubber layer in order to reduce the deflection of the sidewall, its weight will increase, which will increase the weight of the tire and affect the performance of the tire. The current situation is that there are still problems such as negative effects.

The present invention has been made as a result of studies to solve the two problems.
It was guided.

Therefore, the feature 18U of the present invention is to improve the arrangement position of the reinforcing rubber layer and the cord inclination angle of the carcass layer disposed inside the tire, and to improve the cord inclination angle of the carcass layer disposed inside the tire. The purpose of the present invention is to provide a pneumatic safety tire that has significantly improved iJ1 row durability during run-flat driving by modifying the thickness of the rubber layer.

That is, the present invention includes a pair of left and right bead portions having a bead core, a pair of left and right sidewall portions extending in the radial direction of the tire connected to the bead portion, and a sidewall portion from the bead portion of No. 1111. In a pneumatic tire having a carcass layer disposed across the tread part, and a heald layer between the outside of the mouth carcass layer and the tread part, the pneumatic tire has a carcass layer disposed over the tread part, and a heald layer disposed between the outside of the mouth carcass layer and the tread part. The belt layer is arranged adjacent to the lower end of the belt layer, and has a strong rubber layer, which is sandwiched between carcass layers on the inside and side sides, and has a strong rubber layer. The angle of inclination of the carcass layer disposed on the inner side of the layer is in the range of 8 o 0 F or more with respect to the tire circumferential direction in the sidewall portion, and is within 1. d l U in the radial direction of the carcass layer. Ko゛7・layer t meat jI7
The gist of the tire is a pneumatic safety tire characterized in that the thickness T is 15 to 30% of the total wall thickness T in the radial direction in the area χ from the sidewall part to a part of the tire. .

Hereinafter, the present invention will be explained in detail by way of example with reference to the drawings. Figures 1 and 2 show a pneumatic safety tire consisting of a 1 m example of the present invention, and Figure 1 shows the first example of the pneumatic safety tire. jA typical calf half-section 1 explanatory diagram, and FIG. 2 is a meridian half-section explanatory diagram of a second real sister example.

In the figure, E and E2 are pneumatic safety tires consisting of one embodiment of the present invention, and include a pair of left and right bead portions 1 having a bead core 8, and a retirement tire 1′- A pair of left and right sidewall portions 2 extending outward in the radial direction (C), and a sidewall portion 2 from the heat portion 1;
Arranged over the shoulder part 4 and across the trend part 6 i"
The T+-+J of the two inner and outer carcass layers 5 and 6, the outer carcass J sound 6, and the 1jIJ trend part 6.
4.7, a pair of bead cores 8 in 111J are placed next to each other on one side in the radial direction. J'&-t!
Then, a rubber layer 10 (reinforcing) is arranged in the range reaching the lower end 7a of the belt layer 7, and in the part sandwiched between the inner carcass layer 5 and the carcass layer 6 on the side 1. Furthermore, the cord inclination angle of the carcass layer 5 inside this reinforcing rubber layer 10 is set as follows in the sidewall part 2.
800 or less in the circumferential direction of the tire, and the thickness t of the rubber layer 9 on the radially inner side of this inner carcass layer 5 is at least the total thickness in the radial direction in the range from the sidewall portion 2 to the shoulder portion 4. It is constituted by setting it as 15 to 30% of T.

To further explain this structure, the above-mentioned reinforcing rubber layer 10
As shown in the figure, the cross-sectional shape is formed to have the same thickness from the bead part 1 to the shoulder part 4, and as it reaches the tip part, that is, the do part (the end part of the tread part 6) of the end part 7a of the belt layer 7. , one in which the thickness is gradually decreased is preferable.

However, the shape is not limited to the shape described above; of course.

In addition, the hardness of the strong rubber layer 10 mentioned above; JIS
It is preferable to have an image quality of 70 copies or more.

In addition, the size of the inner side of the reinforcing rubber layer 10 mentioned above -1') The carcass layer in the oar part 2 5σ) What is the hood I bevel angle?
It is preferable that the angle is 80° or less with respect to the circumferential direction of the tire, and more preferably 55° to 65° with respect to the circumferential direction of the tire. Moreover, the carcass layer 5 in the tread portion 6
Cord inclination angle, degree is 75° or less, preferably 50° ~
A range of 60° is strongly preferred. And such a carcass layer 5σ]! The seventh seat portion 5a has the bead core 8
Wrap it around and roll it above the bead part 1.
).

- The inner sidewall portion 2 of the reinforcing rubber layer 10 described in
The greater the cord inclination angle G of the carcass layer 5, the greater the effect of increasing the durability during run-flat running by 11°; However, the range that is preferable from the viewpoint of tire performance and success is as follows:
+) Part 11: The angle is 80° or less with respect to the tire circumferential direction, and more preferably 55° to 65°.
, 50° to 6 in the tread portion 6 with respect to the tire circumferential direction
It is 0°.

Next, in this embodiment, the carcass layer 6 disposed on the outside passes through the winding of the inner carcass layer 5 on the side 1 of the barbed end 5a, and extends this heat core 8 up to the end of the bead core 8. It is placed so that it is folded inward without being wrapped around it. This outer carcass layer 6 is preferably a 900 radial carcass in the circumferential direction of the tire in order to withstand the tensile force 1+j during run-flat running.
It may be in the range of 0.degree. However, if the difference in inclination angle between the cord of the inner carcass layer 5 and the Zl- cord of the outer carcass layer 6 becomes large, the evening [
Waves 1-. on the side carcass layer 6. However, this results in an inconvenient situation in which the tire is no longer able to achieve desirable performance.

Nako, carcass layer 5 of the 3-in-1 rule, carcass layer 6 on the side 1
↓(, Even in the case of two or more layers, as described above, in each layer:) It is preferable that the -d is inclined in the tire circumferential direction, but the inclination Jj direction is parallel even if it intersects. However, in the first embodiment shown in FIG. T
The range is 15 to 30% of the tread part 6 and the word f! This is an example in which the thickness of the rubber layer near t1'l1 is set to less than 5%, which makes it possible to reduce the tire weight and reduce the durability of the tire when running on a run flat.

In addition, in the second embodiment shown in FIG. 2, the thickness t of the rubber layer 9 is increased at each portion over the entire inner circumference of the tire, including the bead l''1IS1, the sidewall 1f1, the shoulder part 4, and the tread part 6. I' total thickness in radial direction 15~:30
%, compared to the first embodiment described above, the force in the tire circumferential direction is increased by 11, but the G-G during run flat driving is increased by 11%.
Jru running durability is dog r [J to dry.

I can do something.

Continuing on, as described above, the thickness of the rubber layer 9 on the radially inner side of the carcass layer 5 according to the first rule is determined by adjusting the thickness of the rubber layer 9 in the radial direction at least in the range from the sidewall part 2 to the shoulder part 4. The basis for setting the thickness T to 15 to 30% will be explained.

FIG. 3 is a diagram showing the durability of the run-flat running of the first embodiment according to the present invention, in which the rubber layer 9, 'l'
This is the result of an experiment in which the thickness of the sidewall portion 2 was varied.

The tire specifications and experimental conditions used in the experiment were tire size... +75/70 SR13 negative
Load: 357 K9 empty 'shi L 12... QKri/c-? 'Rim...5J, vertical) 11 is the run-flat mileage, and the horizontal axis is the sidewall part 2 of the rubber layer 9 with #, 5L.
-J and the ratio (%) of the rubber layer thickness t to the total thickness T in the radial direction.

As is clear from this figure, when the thickness of the rubber layer 9 becomes 15% (approx. Approximately 7mm
4 is a diagram showing the durability of the first embodiment of the present invention in an air-filled state, and shows that the rubber layer 9 of the sidewall portion 2 These are the results of experiments with various thicknesses.

The tire specifications and sizes used in the experiment were the same as those used in Figure 3, and the running conditions were as follows.

Speed: 80Kn1/h Air pressure: 1.9Kg/at? After the seventh test step, the step of increasing the Ar*ton by 5% and driving for 2 hours each is extended until the tire is destroyed.

From the results of this test, if the thickness of the rubber layer 9 or the total thickness T in the radial direction becomes thicker than 30% (approximately 7 mm), the mileage will be at a level below I=1 gauge mileage. Then,
It can be seen that the tire performance in the inflated state will no longer be satisfied.

As shown above, the pneumatic safety tire G according to the present invention is reinforced with a reinforcing rubber layer sandwiched between the sidewall section or the carcass layer, so run-flat running is possible. -1. The inner carcass layer has a bias structure, and the rubber layer is further reduced by 1%, which alleviates the FI: and shrinkage stress on the inner carcass layer during run-flat running.
The durability of run-flat running can be greatly improved.

4.Fin't' explanation of 17J Figures 1 and 2 show three favorite safety tires consisting of each embodiment of the present invention, and Figure 1 shows the first actual H11j.
An explanatory diagram of the r/noon half cross section of the example, Figure 2 is the J of the second example.
'Q->t4 cross-sectional explanatory diagram, Figure 3 is a diagram showing the relationship between the thickness of the rubber layer in the sidewall part and the run flat mileage, Figure 1 is the rubber layer in the sidewall part. FIG. 3 is a diagram showing the relationship between the wall thickness of the vehicle and the traveling distance when the internal pressure is filled.

1. Bead part, 2... Sidewall part, 6. Tread part, 4. Part of shoulder, 5.. Inner carcass layer,
6. Outer carcass layer, 7. Heald layer, 8. Beatco γ, 9. Rubber layer, 10. Reinforcement rubber layer.

Agent Patent Attorney Nobuo Ogawa − Patent attorney Teru Nol-1 Ken Patent attorney JK F Kazuhiko

Claims (1)

[Claims] A pair of left and right bead portions having a bead core, a pair of left and right sidewall portions connected to the bead portions and extending outward in the radial direction of the tire, and a carcass layer disposed from the bead portion to the trend portion via the sidewall portion. , in a pneumatic tire having a belt layer between the side of the carcass layer and the trend part, a reinforcing rubber layer disposed adjacent to the outer side in the radial direction of the pair of bead cores and extending from the lower end of the belt layer to C; The reinforcing rubber layer is sandwiched between the carcass layers in the inner and outer sides, and the cord inclination angle of the carcass layer disposed inside the reinforcing rubber layer or in the sidewall part, The thickness (1) of the rubber layer which is within the range of 800 mm or less in the tire circumferential direction and which is radially inner of the inner carcass layer is at least from the sidewall part to a part of the shoulder (within the radius) A pneumatic safety tire characterized by having a total wall thickness (T) of 15 to 30% in the direction.