KR102616050B1 - Tire with improved rolling resistance durability rigidity preformance - Google Patents

Abstract

One embodiment of the present invention is to improve rolling resistance, durability and rigidity performance by changing the structure without changing the material of the tire, a tread in contact with the ground, a belt which is a cord layer laminated on the lower part of the tread to protect the carcass, In a tire including a carcass laminated with a cord and a ply layer below the belt, a sidewall forming a side part of the tire, and a bead formed at the distal end of the sidewall to be coupled to the rim of the wheel, rolling resistance, A tire with improved rolling resistance, durability and rigidity performance is provided, which further includes an insert seat rubber that is inserted and stacked to improve one or more of durability or rigidity performance.

Description

Tires with improved rolling resistance, durability and rigidity performance {TIRE WITH IMPROVED ROLLING RESISTANCE DURABILITY RIGIDITY PREFORMANCE}

The present invention relates to vehicle tires, and more specifically, to tires with improved rolling resistance, durability, and rigidity performance through changes in structure without changes in material.

Of the approximately 30,000 parts that go into a car, the only parts that come into contact with the floor are tires. A rotating tire repeatedly touches and falls on the road surface, and the hard filler particles in the rubber cause friction and consume tire energy. In this way, the energy lost due to frictional heat generation as the tire rolls is called 'tire rolling resistance (RR).'

High rolling resistance means that the car cannot run smoothly. The main reason rolling resistance occurs is because the shape of the inside of the tire changes through friction. As soon as the tire touches the ground, it receives the load of the vehicle, and the rubber inside is momentarily deformed and then restored again, repeating the process. During this process, heat energy is generated and the force needed to roll the wheel is dispersed, which is called rolling and extension movement. At this time, the phenomenon in which some energy is lost as heat in tires made of polymer is called hysteresis loss, which causes tire heat generation and rolling resistance.

There are many factors that determine the rolling resistance of a tire. Compound, tread pattern, air pressure, and tire hardness are the main variables that determine rolling resistance. Additionally, rolling resistance performance has a trade-off relationship with the tire's main performance, wear resistance/wet road braking power.

Additionally, as rolling resistance is reduced, energy loss is reduced, so rolling resistance becomes a variable that can increase fuel efficiency to a certain level. Specifically, according to a study by the Korea Transportation Safety Authority, a 10% reduction in tire rolling resistance resulted in saving fuel efficiency by more than 1.5%. For this reason, tires with improved rolling resistance are sometimes evaluated as ‘eco-friendly tires.’

Accordingly, as _CO2 environmental regulations are being strengthened around the world, vehicle companies are requesting labeling A+ LRR (Low-Rolling Resistance) from tire companies to satisfy WLRP (Worldwide harmonized Light vehicles Test Procedure).

For this reason, in order to improve the rolling resistance of tires, the development of tire materials that lower tan δ is in progress, but this requires a lot of time and effort, making it difficult to respond through compound development.

Accordingly, the development of rolling resistance reduction technology by improving the structure of the tire is required so that it can be applied at low cost and in a short time and minimize the trade off for improving rolling resistance.

Registered Utility Model Publication No. 20-0411997

Therefore, the present invention is intended to solve the problems of the prior art described above, and its technical task is to provide a tire with improved rolling resistance, durability, and rigidity performance by changing the lamination structure of the tire without changing the tire material.

An embodiment of the present invention for achieving the above-described object includes a tread in contact with the ground, a belt that is a cord layer laminated on the lower part of the tread to protect the carcass, and a carcass that is laminated including a cord and a ply layer on the lower part of the belt. , an insert that is inserted and laminated to improve one or more of rolling resistance, durability, or rigidity performance in a tire including a sidewall forming the side portion of the tire and a bead formed at the distal end of the sidewall to be coupled to the rim of the wheel. A tire with improved rolling resistance, durability, and rigidity performance is provided, which further includes a seat rubber.

The insert seat rubber is between the belt and the carcass, between the carcass and the sidewall, between the carcass and the inner liner when the tire has an inner liner, or between the carcass and the inner liner on the inner side of the bead. It may be formed by stacking at one or more positions among the layers.

The insert seat rubber may be designed so that the starting end is located in an area between the center of the tread (center of the crown) and the width of the belt.

When the end portion of the insert seat rubber does not turn up the bead, the end portion may be designed to be located in an area between the bead and the section width of the tire.

The insert seat rubber may be designed so that when the end turns up the bead, the end is located in the area between the bead and the center of the tread.

The insert seat rubber may have a compound hardness of 56 to 89 IRHD.

The insert seat rubber may have a compound tan δ of 0.02 to 0.3.

The insert seat rubber may have a thickness of 0.5 to 3.0 mm.

In the tire according to an embodiment of the present invention described above, despite the increase in the weight of the tire, the heat generation (deformation) in the flexible zone is reduced, and the actual rolling resistance (RR(N)) output is 2 to 4. Provides a % improvement effect.

In addition, as tires are made lighter in order to achieve high rolling resistance performance, the rigidity of side parts such as side walls decreases, and cornering stiffness under high loads decreases. However, the tire according to an embodiment of the present invention Provides the effect of minimizing the decrease in side stiffness and high load cornering rigidity that occurs when rolling resistance performance is improved.

In addition, the tire of one embodiment of the present invention minimizes heat generation and increases vertical rigidity, thereby increasing the degree of freedom for side stiffness control design and heat generation minimization design, so that designers can increase their design freedom in lightweight tires. It provides the effect of

In addition, the tire of one embodiment of the present invention provides the effect of allowing it to be applied without much change in the process of the manufacturing plant.

1 is a schematic cross-sectional view of a tire 1 with improved rolling resistance, durability and rigidity performance according to an embodiment of the present invention.
Figure 2 shows an insert sheet rubber (2) according to an embodiment of the present invention, the starting end (2s) is located in the area between the center of the tread (10) and both ends of the belt (20). , A diagram schematically showing an embodiment in which the end portion 2e is stacked between the carcass 30 and the inner liner 40 so that it is located at the end portion 63a of the bead filler.
Figure 3 shows rolling resistance and volume by finite element simulation (FE simulation) for a tire (a) to which the technology of the present invention is not applied and a tire (1) (b) according to an embodiment of the present invention. Table representing change.
Figure 4 shows the heat generation of the sidewall by finite element simulation (FE simulation) for a tire (a) to which the technology of the present invention is not applied and a tire (1) (b) according to an embodiment of the present invention. Drawing showing the differences.

In the following description of the present invention, if a detailed description of a related known function or configuration is judged to unnecessarily obscure the gist of the present invention, the detailed description will be omitted.

Since the embodiments according to the concept of the present invention can make various changes and have various forms, specific embodiments will be illustrated in the drawings and described in detail in the specification or application. However, this is not intended to limit the embodiments according to the concept of the present invention to a specific disclosed form, and the present invention should be understood to include all changes, equivalents, and substitutes included in the spirit and technical scope of the present invention.

When a component is said to be "connected" or "connected" to another component, it is understood that it may be directly connected to or connected to the other component, but that other components may exist in between. It should be. On the other hand, when it is mentioned that a component is “directly connected” or “directly connected” to another component, it should be understood that there are no other components in between. Other expressions that describe the relationship between components, such as "between" and "immediately between" or "neighboring" and "directly adjacent to" should be interpreted similarly.

The terms used herein are only used to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as “include” or “have” are intended to indicate the existence of a described feature, number, step, operation, component, part, or combination thereof, but are not intended to indicate the presence of one or more other features or numbers. It should be understood that this does not preclude the existence or addition of steps, operations, components, parts, or combinations thereof.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings showing embodiments of the present invention.

Figure 1 is a schematic cross-sectional view of a tire (1) with improved rolling resistance, durability and rigidity performance according to an embodiment of the present invention, and Figure 2 is an insert sheet rubber (insert sheet rubber) (2) according to an embodiment of the present invention. ), the starting end (2s) is located in the area between the center of the tread (10) and both ends of the belt (20), and the end (2e) is located at the bead filler end (63a). ) This is a diagram showing a schematic embodiment of stacking between the inner liner 40 and the inner liner 40.

As shown in FIG. 1, the tire 1 includes a tread 10 in which a plurality of grooves are formed and in contact with the ground, a belt 20, which is a cord layer laminated on the lower part of the tread 10 to protect the carcass, and a lower part of the belt. A carcass (30), which includes a cord and a ply layer, is integrally attached to the inner peripheral surface of the tread (10) and the sidewall (50), and is stacked to form a turn-up head (61) at both ends of the sidewall (50), The inner liner 40 laminated on the lower part of the carcass 30 to seal air, the side wall 50 forming the side portion on both sides of the tread 10, and the side wall to be coupled to the rim of the wheel. It includes a bead 60 formed at the distal end and an insert seat rubber 2 that is inserted and stacked to improve one or more of rotation resistance, durability, or rigidity performance.

The tread 10 is a part in contact with the ground and is made of a thick rubber layer that is resistant to tearing, impact, etc. to protect the belt 20 and the carcass 30 in the tire, and is highly abrasion-resistant to increase tire life.

The belt 20 is formed by laminating one or more layers between the tread 10 and the carcass 30 using a steel cord coated with rubber, etc., and is configured to maintain the contact surface of the tread 10. . Specifically, the belt 20 serves to alleviate shock received from the outside and prevent cracks or trauma in the tread 10 from directly reaching the carcass 30, while also protecting the rubber layer and the carcass 30. Prevents separation of layers.

The carcass 30 is a structure that forms the framework of the tire 1 and is a general term for the ply and bead parts in which the cord is placed in parallel and covered with a thin rubber layer. It maintains the air pressure inside the tire and protects against load and impact. It is configured to perform a bearing function.

The inner liner 40 is composed only of tubeless tires and forms an air sealing layer inside the tire to replace the tube inside the tire. It is a rubber layer made of butyl rubber or polyisoprene, which is a synthetic rubber with excellent air sealing properties. It consists of

The sidewall 50 is configured to form a shoulder or shoulder and inner liner 40 on both sides of the tread 10 and extend to form a side portion. The sidewall 50 of the above-described configuration protects the carcass 30 and is connected to the tread 10 to form the side of the tire 1 and increases riding comfort by performing a flexion/extension movement.

The bead 60 includes a bead core 62 inserted into the wheel side from the inside of the turn-up head 61 to be coupled to the rim of the wheel, a bead filler 63 inserted into the tread side of the bead core, and the turn-up It is formed at the distal end of the sidewall 50, including a reinforcing material (not shown) inserted into the interface of the head 61.

The insert seat rubber 2 is located between the belt 20 and the carcass 30, between the carcass 30 and the sidewall 50, and where the tire 1 has an inner liner 40. In this case, it may be laminated at one or more positions between the carcass 30 and the inner liner 40 or between the carcass 30 and the inner liner 40 on the inner side of the bead 60. .

In FIG. 1, the curved arrow L1 indicates an area where the starting end 2s of the insert seat rubber 2 can be located. And the curved arrow L2 indicates an area where the end portion 2e of the insert seat rubber 2 can be located.

The starting end 2s of the insert seat rubber 2 located in the direction toward the center of the tread 10 may be designed to be located in an area between the center of the tread (center of the crown) and the width of the belt. In the case where the end portion (2e) of the bead (60) side of the insert seat rubber (2) does not turn up the bead, the end portion (2e) of the insert seat rubber (2) is connected to the bead (60) and the tie (1). It can be designed to be located in the area between the section widths. In contrast, when the end portion 2e of the insert seat rubber 2 turns up the bead 60, the end portion 2e of the insert seat rubber 2 is positioned at the equator of the tread 10 of the tire 1. Based on , it may be designed to be located in an area connected to the sidewall 50 and the bead 60 on one side of the tread 10.

Figure 2 shows the above-described insert seat rubber (2) with its starting end (2s) positioned in the area between the center of the tread (10) and both ends of the belt (20), and the end portion of the insert seat rubber (2) ( 2e) schematically shows an embodiment in which lamination is performed between the carcass 30 and the inner liner 40 so that it is located at the end portion 63a of the bead filler.

In other words, as described above, the insert seat rubber 2 can control the deformation and heat dissipation of the tread, side, and bead by selectively inserting and stacking it at various positions such as the tread, side, and bead of the tire, allowing the designer to control the deformation of the tread, side, and bead. Provides design freedom to users.

As described above, the insert seat rubber 2, which is inserted and laminated inside the tire 1, has a compound hardness of 56 to 89 IRHD to improve rolling resistance performance, durability, or rigidity performance, and is a compound that exhibits the kinetic characteristics of rubber. tan δ may be 0.02 to 0.3, and the thickness may be 0.5 to 3.0 mm.

Figure 3 shows rolling resistance and volume by finite element simulation (FE simulation) for a tire (a) to which the technology of the present invention is not applied and a tire (1) (b) according to an embodiment of the present invention. It is a table showing changes, and Figure 4 is a finite element simulation (FE simulation) for a tire (a) to which the technology of the present invention is not applied and a tire (1) (b) according to an embodiment of the present invention. This is a diagram showing the difference in heat generation of the sidewall.

The table in Figure 3 (a) shows the rotational resistance (RR(N)) calculation amount and volume for each member of a tire of the prior art to which the technology of the present invention is not applied, and Figure 3 (b) shows the calculated amount and volume of the tire of the prior art to which the technology of the present invention is not applied. It shows the rotational resistance (RR(N)) calculation amount and volume for each member of the tire according to the embodiment.

In the table of Figure 3, CTR is Cap Trade, SFT is Side Filling Tape, CCT is Carcass Topping, BTT is Belt Topping, and IL is Inner Liner. Liner), BSW is Black Side Wall, RIC is Rim Cushion, BDF is Bead Filler, and VBOLUM and RR(N) in Figure 3 are the respective volumes and rotational resistance ( RR(N)).

As shown in the comparison of the tables in Figures 3 (a) and (b), in the case of the tire to which the present invention is applied, the actual rolling resistance (RR(N)) output decreases even though the weight increases to 6.80E-03, resulting in rotation. It was confirmed that resistance performance was improved by 2 to 4%.

In the case of Figure 4, after creating a model for performing FE simulation, as shown in Figure 4 (a), the analysis result using SMART, an in-house solver developed by the applicant, is shown in Figure 4 (c). Figure 4 (b) shows the results of heat generation analysis using SMART, an in-house solver, for tires to which the insert seat rubber of the present invention is not applied.

As shown in Figure 4, in the case of tires to which the insert seat rubber of the present invention was applied, it was confirmed that the heat generation (deformation) in the flexible zone (FZ) was reduced despite the increase in weight.

As shown in Figures 3 and 4, when the insert seat rubber is applied to the tire according to the present invention, heat generation and deformation of the inner part of the tire are reduced, thereby obtaining advantageous results in terms of durability.

In other words, the insert seat rubber of the present invention can be applied to various design and application methods as shown in FIG. 1 depending on various performances, enabling various designs.

In addition, it was confirmed that the insert seat rubber absorbs a lot of the impact caused by the load applied to the bead and tread parts, which are different parts, depending on the design and application method and compound characteristics.

In addition, as weight reduction is carried out to achieve increased rotational resistance, the rigidity of the side portion and the cornering stiffness under high load decrease, but the stiffness of the side wall is reduced by applying the insert seat rubber of the present invention as shown in Figure 2. can be increased, and despite the increased rolling resistance, it is possible to compensate for the problems of lowered rigidity of the side part and lowered cornering rigidity under high load.

As a result of FE simulation, when the insert seat rubber of the present invention was not applied, Kv was 19.5mm/kgf, but by applying the insert seat rubber of the present invention, it was confirmed that the vertical rigidity increased by about 3% to 20.1mm/kgf. Accordingly, it was confirmed that designers can increase their design freedom in lightweight tires, and that there is no difficulty in applying the present invention to the tire production process because it does not cause much damage to the current factory process.

The tire 1 for explaining the embodiment of the present invention has been described by taking a tubeless pneumatic tire with an inner liner as an example, but the present invention can also be applied to various tires such as a tube-type pneumatic tire without an inner liner. It is self-evident that it exists.

The technical idea of the present invention described above has been specifically described in preferred embodiments, but it should be noted that the embodiments are for illustrative purposes only and are not intended for limitation. Additionally, those skilled in the art of the present invention will understand that various embodiments are possible within the scope of the technical idea of the present invention. Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the attached claims.

1: tires
2: Insert seat rubber
2s: Insert seat rubber starting end
2e: End of insert seat rubber
10: Tread
20: belt
30: Carcass
40: Innerliner
50: sidewall
60: Bead
61: Turn-up head
62: Bidcore
63: Bead filler
63a: End of bead filler
FZ: Flexible Zone

Claims (8)

A tread in contact with the ground, a belt that is a cord layer laminated on the lower part of the tread to protect the carcass, a carcass that includes a cord and a ply layer on the lower part of the belt, a sidewall that forms the side part of the tire, and the rim of the wheel. In a tire including a bead formed at the distal end of the sidewall to be coupled,
It further includes an insert seat rubber that is inserted and laminated to improve one or more of rotational resistance, durability, or rigidity performance,
The insert seat rubber is formed of tire compound,
A portion between the starting end and the ending end of the insert seat rubber is formed between the carcass and the inner liner,
When the end of the insert seat rubber turns up the bead, the end of the insert seat rubber is located in an area connected to the sidewall and the bead on one side of the tread based on the equator of the tread. tire. delete The tire according to claim 1, wherein the insert seat rubber is designed such that a starting end is located in an area between the center of the tread (center of the crown) and the width of the belt. delete delete The tire according to claim 1, wherein the insert seat rubber has a compound hardness of 56 to 89 IRHD. The tire according to claim 1, wherein the insert seat rubber has a compound tan δ of 0.02 to 0.3. The tire according to claim 1, wherein the insert seat rubber has a thickness of 0.5 to 3.0 mm.