KR102113854B1 - Runflat tire - Google Patents

Abstract

A run flat tire is disclosed.
A run flat tire according to an embodiment of the present invention includes a tread portion directly contacting a road surface; An inner liner that forms an inner surface of the tire to prevent air from leaking to the outside; A belt portion disposed radially outside the tire of the inner liner; A cap ply disposed radially outside the tire of the belt portion; A side wall forming a side surface of the tire; A bead part connected to the end of the side wall and seated on the tire rim; And a carcass which is disposed radially outside the tire of the inner liner, and at least partially encloses and turns up the bead, and the turned-up end of the carcass is positioned overlapping the belt part with the belt radially outside the tire.

Description

RUNFLAT TIRE

The present invention relates to a run flat tire.

In general, pneumatic tires have a support function that supports the entire load of the vehicle, a power transmission function that transmits the driving and braking power of the vehicle to the road surface, a shock relief function that relieves external shocks caused by irregular road surfaces, and a vehicle's traveling direction It is equipped with a variety of location switching functions, such as to switch the location according to.

However, in the case of such a conventional pneumatic tire, when the internal pressure of the tire is lost, the tire will sit down under the weight of the vehicle, and the bead portion will contact the tread portion, so that the vehicle can no longer travel. Accordingly, in order to prevent driving from being impossible due to a decrease in the internal pressure of a tire such as a puncture during driving, a run flat tire capable of driving a certain distance even when the internal pressure of the tire decreases has been proposed.

Such a run flat tire may constitute a side reinforcement rubber layer having a cross-section crescent shape on the side wall of the tire. The run flat tire supports the tire load at normal pressure and the load at the side reinforcement rubber layer when running the run flat. For this reason, the run flat tire can be stably driven because there is no sudden change in the vehicle even when the air pressure inside the tire suddenly decreases during tire puncture, and even when there is no risk of the driver suddenly operating the steering wheel due to changes in vehicle behavior. safe.

However, the run flat tire is a tire capable of driving in a state where the air pressure is 0, and the driving conditions are very severe compared to the pneumatic tire. In the case of a run flat tire running in a state where the air pressure is 0, the tire shape is greatly bent when a load is applied, the inside of the side wall is compressed, and the outside of the side wall is tensioned. In addition, due to the characteristics of the run flat tire, the entire area of the tread portion is not grounded to the ground when driving in a state of zero air pressure, but only the shoulder portion is grounded to the ground. Therefore, as the deformation of the shoulder portion is larger than that of the pneumatic tire, there is a problem that the durability performance of the tire is deteriorated.

Accordingly, in order to improve the durability performance of the run flat tire, if the volume of the side reinforced rubber layer constituting the side wall of the run flat tire is increased, tire durability and safety performance are improved when driving in a punctured state, but the volume of the side reinforced rubber layer When is increased, there is a problem that the weight of the run flat tire is increased.

Accordingly, there is a need to develop a technology for a run flat tire with improved durability without increasing weight.

The embodiments of the present invention are proposed in view of the problems of the prior art as described above, and are intended to provide a run flat tire with improved durability without increasing weight.

According to one aspect of the invention, the tread portion directly in contact with the road surface; An inner liner that forms an inner surface of the tire to prevent air from leaking to the outside; A belt portion disposed radially outside the tire of the inner liner; A cap ply disposed on the tire radially outside of the belt portion; A side wall forming a side surface of the tire; A bead part connected to an end of the side wall and seated on a tire rim; And a carcass which is disposed radially outside the tire of the inner liner and at least partially encloses and turns up the bead, and the turned-up end of the carcass is located on the outside of the belt part overlapping the belt part, Run flat tires may be provided.

Further, at least a portion of the cap ply may be provided between the turned-up end of the carcass and the belt portion on the radially outer side of the tire of the belt portion, and may be disposed in the driving direction of the tire.

In addition, the belt portion, a first belt disposed in the radially outer side of the tire of the inner liner; And a second belt disposed outside the first belt.

In addition, the cap ply may satisfy Condition 1 below.

[Conditional Expression 1]

M> X-Y

(M is the width of the cap ply provided between the carcass and the belt portion that is located overlapping the belt portion on the tire radially outside the belt portion,

X is the width from the center of the tire to the end of the first belt,

Y is the width from the center of the tire to the end of the second belt)

In addition, the carcass may satisfy the following conditional expression 2.

[Conditional Expression 2]

Z ≥ (X-Y) / 2

(Z is the length of the carcass which is located on the radially outer side of the tire of the belt part overlapping with the belt part,

X is the width from the center of the tire to the end of the first belt,

Y is the width from the center of the tire to the end of the second belt)

In addition, a shoulder portion connecting between the tread portion and the side wall; And a side reinforcement rubber layer disposed inside the tire in the width direction of the side wall to support the load of the tire when the tire is punctured.

According to embodiments of the present invention, there is an effect that the durability performance is improved without increasing the weight of the run flat tire.

1 is a view of a run flat tire according to an embodiment of the present invention.
FIG. 2 is a view showing an example of a cap ply of the run flat tire of FIG. 1.
FIG. 3 is a view showing a modification of the cap ply of the run flat tire of FIG. 1.
4 is a view showing a belt portion of the run flat tire of FIG. 1.
5 is a graph showing the strain energy of the end of the belt portion and the strain energy of the side reinforcement rubber layer located on the shoulder portion according to the position where the turned-up end of the carcass is disposed.
Figure 6 is a graph showing the strain energy of the end of the belt portion located in the shoulder portion according to the degree to which the carcass overlaps the belt portion in the radial direction outside of the belt portion.
7 is a graph showing the deformation energy of the side reinforced rubber layer according to the degree to which the carcass overlaps the belt portion on the radially outer side of the belt portion.

Hereinafter, with reference to the accompanying drawings will be described in detail the configuration and operation according to an embodiment of the present invention. The following description is one of several aspects of the present invention that can be patented, and the following description may form part of the detailed description of the present invention.

However, specific descriptions of well-known configurations or functions in describing the present invention may be omitted to clarify the present invention.

The present invention can be applied to various changes and may include various embodiments, and specific embodiments will be illustrated in the drawings and described in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and should be understood as including all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

Terms including ordinal numbers such as first and second may be used to describe various components, but the components are not limited by these terms. These terms are only used to distinguish one component from another.

When an element is said to be 'allocated' or 'equipped' to another element, it is understood that other elements may be directly disposed or provided in the other element, but other elements may exist in the middle. It should be.

The terms used in this application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise.

Hereinafter, a run flat tire according to an embodiment of the present invention will be described with reference to the drawings.

1 to 7, the run flat tire 1 according to an embodiment of the present invention includes a tread part 10, an inner liner 20, a belt part 30, a cap ply 40, and a side wall 50, a shoulder portion 60, a bead portion 70, a carcass 80 and a side reinforcement rubber layer 90 may be included.

The tread portion 10 is a portion that directly contacts the road surface, and may contact the road surface to form a ground surface.

The inner liner 20 may form an inner surface of the run flat tire 1 to prevent air from leaking to the outside.

The belt portion 30 may be disposed outside the tire radially of the inner liner 20. At this time, the belt portion 30 includes a first belt 31 disposed on the radially outer side of the tire of the inner liner 20 and a second belt 32 disposed on the radially outer side of the tire of the first belt 31. can do. Here, the width X from the center of the run flat tire 1 to the end of the first belt 31 and the width Y from the center of the run flat tire 1 to the end of the second belt 32 are It can be configured differently.

Meanwhile, an end of the first belt 31 and an end of the second belt 32 may be disposed between the inner liner 20 and the cap ply 40.

The cap ply 40 may be disposed outside the tire radially of the belt portion 30. At this time, at least a portion of the cap ply 40 may be provided between the belt portion 30 and the turned-up end of the carcass 80 from the outside of the belt portion 30.

On the other hand, so that the longitudinal deformation of the cap ply 40 is minimized, the cap ply 40 is arranged to have an angle of approximately 0 degrees in the driving direction of the run flat tire 1 from the tire radially outside of the belt portion 30. Can be.

As described above, since the cap ply 40 having an angle of approximately 0 degrees is disposed between the belt part 30 and the carcass 80 in the running direction of the run flat tire 1, the turn-up end of the carcass 80 and The carcass 80 may not be damaged as it is located in the tire radially inner side of the belt part 30 and the belt part 30 and the carcass 80 are rubbed.

At this time, in order to minimize damage to the carcass 80, which may occur due to friction between the ends of the first belt 31 and the second belt 32 and the carcass 80, the cap ply 40 has the following conditional expression: 1 can be satisfied.

[Conditional Expression 1]

M> X-Y

Here, M means the width of the cap ply 40 provided between the carcass 80 and the belt part 30, which are located overlapping the belt part 30 from the tire radially outside of the belt part 30, , X means the width from the center of the run flat tire 1 to the end of the first belt 31, Y means the width from the center of the run flat tire 1 to the end of the second belt 32. .

The side wall 50 is a portion forming the side surface of the run flat tire 1, and when the puncture of the run flat tire 1 occurs inside the tire width direction of the side wall 50, the load of the run flat tire 1 is applied. A side reinforcement rubber layer 90 that can be supported may be disposed.

The shoulder portion 60 is a portion that connects the tread portion 10 and the side wall 50, and may contact the road surface when the run flat tire 1 runs on the run flat.

On the other hand, when the shoulder portion 60 is in contact with the road surface when running the run flat of the run flat tire 1, the turn up end of the carcass 80 surrounding the bead portion 70 and turned up is outside the belt portion 30. Since it is located overlapping with the belt portion 30, the lateral deformation of the shoulder portion 60 is reduced, and as a result, tension outside the shoulder portion 60 can be minimized. Accordingly, the deformation energy of the shoulder portion 60 is reduced, and further, the durability performance of the run flat tire 1 can be improved.

The bead portion 70 is connected to the end of the side wall 50 and can be seated on the tire rim.

The carcass 80 is disposed outside the tire radially of the inner liner 20, and at least a portion of the inner liner 20 may be wrapped around the bead portion 70 and turned up. At this time, the turned-up end of the carcass 80 may be positioned to overlap the belt portion 30 from the tire radially outside of the belt portion 30.

On the other hand, so that the lateral deformation of the carcass 80 can be minimized, the carcass 80 is arranged to have an angle of approximately 90 degrees in the driving direction of the run flat tire 1 from the radially outer side of the inner liner 20. Can be.

When the length Z of the carcass 80, which is located overlapping with the belt part 30 on the radially outer side of the belt part 30, is 20 mm, the turned-up end of the carcass 80 is disposed. Accordingly, the strain energy of the end portion of the belt portion 30 located on the shoulder portion 60 and the strain energy of the side reinforcement rubber layer 90 are shown below showing the strain energy values obtained by experiments (Comparative Examples 1 to 3). It is as shown in [Table 1].

Z (mm) The position of the carcass' turned up end Strain energy (psi) Comparative Example 1 20 Radial inner side of the belt End of belt part located on shoulder part 24.0 Side reinforcement rubber layer 70.3 Comparative Example 2 Between the radially outer tire of the belt section and the radially inner tire of the cap ply End of belt part located on shoulder part 24.9 Side reinforcement rubber layer 69.9 Comparative Example 3 Radial outer side of the tire of the belt part without a cap ply on the radially outer side of the tire End of belt part located on shoulder part 24.7 Side reinforcement rubber layer 70.7 Example Radial outer tire of the cap ply End of belt part located on shoulder part 15.1 Side reinforcement rubber layer 69.2

Referring to Table 1 and FIG. 5, of the belt portion 30 located in the shoulder portion 60 when the turned-up end of the carcass 80 is located outside the tire radially of the belt portion 30 The deformation energy of the end and the deformation energy of the side reinforcing rubber layer 90 are located in the radially inner side of the tire of the carcass 80, or the turned up end of the carcass 80 is in the belt part. Deformation energy and side reinforcement rubber layer 90 at the end of the belt portion 30 located at the shoulder portion 60 when located between the 30 and the cap ply 40 or when the cap ply 40 is not present ) Was found to be smaller than the strain energy.

Therefore, the endurance performance of the run flat tire 1 when the turned-up end of the carcass 80 is located radially outside the tire of the belt section 30 is the turned-up end of the carcass 80 is the belt section ( Run flat when the radially inner side of the tire of 30) or the turned-up end of the carcass 80 is located between the belt portion 30 and the cap ply 40 or when the cap ply 40 is not present It was found that the durability performance of the tire 1 was improved.

On the other hand, the amount of overlap of the carcass 80 that can be expected to improve the durability performance by reducing the strain energy can satisfy the following conditional expression 2.

[Conditional Expression 2]

Z ≥ (X-Y) / 2

Here, Z denotes the length of the carcass 80 located in the radial direction outside of the belt portion 30 and overlaps with the belt portion 30, and X is the first belt in the center of the run flat tire 1 (31) means the width to the end, and Y means the width from the center of the run flat tire (1) to the end of the second belt (32).

On the other hand, the end of the belt portion 30 located on the shoulder portion 60 according to the length (Z) of the carcass 80 positioned overlapping the belt portion 30 from the tire radially outside of the belt portion 30 The strain energy and the strain energy of the side reinforcing rubber layer 90 are as shown in Table 2 below showing the strain energy values obtained by experiments (V1 to V6).

Z The degree to which the carcass overlaps the cap ply on the radially outer side of the cap ply (mm) Strain energy (psi) V1 Z <(X-Y) / 2 0 End of belt part located on shoulder part 40.3 Side reinforcement rubber layer 71.0 V2 Z = (X-Y) / 2 3 End of belt part located on shoulder part 12.4 Side reinforcement rubber layer 70.8 V3 Z> (X-Y) / 2 6 End of belt part located on shoulder part 11.7 Side reinforcement rubber layer 70.3 V4 9 End of belt part located on shoulder part 13.3 Side reinforcement rubber layer 70.1 V5 15 End of belt part located on shoulder part 14.2 Side reinforcement rubber layer 69.5 V6 20 End of belt part located on shoulder part 15.1 Side reinforcement rubber layer 69.2 V7 25 End of belt part located on shoulder part 15.5 Side reinforcement rubber layer 68.8

Referring to [Table 2], FIGS. 6 and 7, the length Z of the carcass 80 located on the outside of the belt portion 30 overlapping the belt portion 30 is that of the run flat tire 1 Width (X) / 2 from the center to the end of the first belt 31-Shoulder from the center of the run flat tire 1 to the end of the second belt 32 is greater than or equal to the width (Y) / 2 value A car in which the strain energy of the end of the belt part 30 located in the part 60 and the strain energy of the side reinforcement rubber layer 90 overlap with the belt part 30 in the radial direction outside of the tire of the belt part 30. The length (Z) of the casing (80) is from the center of the run flat tire (1) to the end of the first belt (31) width (X) / 2-second belt (32) from the center of the run flat tire (1). It was found that the strain energy of the end portion of the belt portion 30 located in the shoulder portion 60 and the strain energy of the side reinforcing rubber layer 90 are smaller than the width (Y) / 2 value to the end of.

In conclusion, the length (Z) of the carcass (80) located in the radial direction outside of the tire of the belt portion (30) overlapping with the belt portion (30) is the first belt (31) at the center of the run flat tire (1). Endurance performance of the run flat tire 1 when the width is equal to or greater than the width (Y) / 2 value from the center of the width (X) / 2-run flat tire 1 to the end of the second belt 32 The length (Z) of the carcass (80) located in the radial direction outside of the belt portion (30) overlapping with the belt portion (30) is the end of the first belt (31) at the center of the run flat tire (1). From the center of the width (X) / 2-run flat tire (1) to the end of the second belt (32), it is found that the durability performance of the run flat tire (1) is improved when it is smaller than the width (Y) / 2 value. Could.

The side reinforcing rubber layer 90 may have a crescent-shaped cross section, and even when the internal pressure of the run flat tire 1 decreases, a portion of the load is supported, thereby enabling run flat running at a predetermined distance.

According to the above, in the run flat tire 1 according to an embodiment of the present invention, the turned-up end of the carcass 80 is not disposed inside the tire radially of the belt portion 30, but the belt portion 30 ) As the tire is radially turned outward in the radial direction and overlaps with the belt portion 30 and positioned, the deformation at the end of the belt portion 30 located in the shoulder portion 60 can be prevented. Accordingly, there is an effect that the durability performance of the run flat tire 1 can be improved without increasing the weight of the run flat tire 1.

Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art to which the present invention pertains may be implemented in other specific forms without changing the technical spirit or essential features of the present invention. You will understand. For example, a person skilled in the art can change the material, size, etc. of each component depending on the application field, or combine or replace the embodiments to implement the present invention in a form not explicitly disclosed, but this also applies to the present invention. It is not beyond the scope of. Therefore, the embodiments described above are illustrative in all respects and should not be understood as limiting, and it should be said that these modified embodiments are included in the technical idea described in the claims of the present invention.

1: Run flat tire 10: Tread section
20: inner liner 30: belt
31: first belt 32: second belt
40: cap fly 50: side wall
60: shoulder portion 70: bead portion
80: carcass 90: side reinforcement rubber layer

Claims (6)

A tread portion directly contacting the road surface;
An inner liner that forms an inner surface of the tire to prevent air from leaking to the outside;
A belt portion disposed radially outside the tire of the inner liner;
A cap ply disposed on the tire radially outside of the belt portion;
A side wall forming a side surface of the tire;
A bead part connected to an end of the side wall and seated on a tire rim; And
The inner liner is disposed on the radially outer side of the tire, and includes at least a portion of the carcass surrounding the bead and turned up,
The turned-up end of the carcass is located on the radially outer side of the tire of the belt portion and overlaps the belt portion,
At least a portion of the cap ply,
Extending between the turned-up end of the carcass and the belt part, covering an end of the belt part so that the turned-up end of the carcass does not contact the belt part;
The end of the cap ply is fixed between the carcass and the turned-up part of the carcass,
Run flat tire. delete According to claim 1,
The belt portion,
A first belt disposed radially outside the tire of the inner liner; And
And a second belt disposed radially outside the tire of the first belt,
Run flat tire. The method of claim 3,
The cap ply satisfies the following conditional expression 1,
Run flat tire.
[Conditional Expression 1]
M> XY
(M is the width of the cap ply provided between the carcass and the belt portion that is located overlapping the belt portion from the tire radially outside the belt portion,
X is the width from the center of the tire to the end of the first belt,
Y is the width from the center of the tire to the end of the second belt) The method of claim 3,
The carcass satisfies the following conditional expression 2,
Run flat tire.
[Conditional Expression 2]
Z ≥ (XY) / 2
(Z is the length of the carcass that is located on the radially outer side of the belt portion overlapping the belt portion,
X is the width from the center of the tire to the end of the first belt,
Y is the width from the center of the tire to the end of the second belt) According to claim 1,
A shoulder portion connecting between the tread portion and the side wall; And
It is disposed inside the tire width direction of the side wall further comprises a side reinforcement rubber layer for supporting the load of the tire when the tire is punctured,
Run flat tire.

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