KR102316668B1 - Car tires with reinforced shoulders - Google Patents

Abstract

Disclosed is a shoulder reinforced tire. The shoulder reinforced tire in accordance with the present invention is a vehicle tire consisting of a tread, a sidewall and a bead. The tread is made by integrally extruding an outer cap tread and an inner under tread having a relatively higher hardness than the cap tread. In the under tread, both ends corresponding to a shoulder of the cap tread are thicker than a central portion in a width direction of the tire. In accordance with the present invention, separation or peeling of the cap tread from the under tread is effectively prevented, so that safe driving can be achieved. Accurate vehicle control is possible as the loss of steering force is reduced by providing strong support for the shoulder pressed by centrifugal force when driving the vehicle left and right or steering a steering wheel by protruding structures of both ends of the under tread. The cap tread is formed to a sufficient thickness by a recessed structure of the central portion of the under tread, such that the characteristics in accordance with a material or a pattern can be fully realized.

Description

Shoulder Reinforced Tires {CAR TIRES WITH REINFORCED SHOULDERS}

The present invention relates to a shoulder-reinforced tire, and more particularly, to an automobile tire capable of improving the driving ability or steering performance of a vehicle by limiting the structure and material of the undertread supporting the lower part of the tire cap tread will be.

In general, as shown in FIG. 6 , the multi-layer extrusion structure of the tread 10 constituting the pneumatic tire, the belt 40 under the belt 40, the carcass 50 under the belt, and the bead 30 sealed and fastened to the wheel ) and the inner liner 60 for sealing the internal air are already well-known technical configurations.

For each of these components, tire manufacturers are conducting various research and development to improve the steering, stability, ride comfort, fuel efficiency, snow performance, abrasion resistance, braking performance, and durability of the tire.

However, in these configurations, when characteristics such as steering performance are improved or improved in relation to one configuration due to technical correlations that are partially betrayed by each other, characteristics such as ride comfort for other configurations are attenuated, that is, a trade-off (trade-off). off), there are certain technical limitations.

Therefore, tire manufacturers, in the case of the tread 10 in direct contact with the road surface at the outside of the tire, are difficult to satisfy all the performances of rolling resistance, braking, steering, etc. at the same time. We manufacture various types of tires by stacking them.

For example, in a vehicle that requires accurate handling, the under tread 14 made of a different rubber material than the cap tread under the cap tread 12 as shown in FIG. ) is laminated.

However, the undertread 14 shown in FIG. 6 forms a gently inclined curved surface in the shoulder area on both sides formed over the edge of the cap tread 12 and the upper end of the sidewall 20, and a flat surface in the center Since the joint area between the undertread 14 and the cap tread 12 is structurally small because the There was an easy problem.

In addition, the shape of the undertread 14 shown in FIG. 6 makes it difficult to structurally and firmly support the thick shoulder, which is easily pressed due to the centrifugal force applied outward in the rotational running direction, so that the steering force is lost contrary to the intended one. there was a problem with

Furthermore, the central portion of the cap tread 12, where the tread 10 pattern and grooves of a predetermined depth are formed through the vulcanization process, the thickness of the cap tread 12 is excessively thin due to the untread path 14 having the above shape. There was a problem in that blocks between the grooves were partially separated or peeled along with the problem that the characteristics intended to be implemented with the material or pattern of the tread 12 could not be fully exhibited.

The problems of the conventional undertread 14 as described above, as a result, do not sufficiently support the cap tread 12 and result in incomplete contact with the road surface. Rather, it hinders the situation, and structural improvement is necessary for this.

An object of the present invention is to prevent the separation or peeling of the multi-layer tread composed of the cap tread and the under tread, and to reduce the loss of steering force by providing strong support for the shoulder pressed by centrifugal force when the vehicle rotates left and right. and to provide a shoulder-reinforced tire that can fully realize the characteristics of the cap tread according to the material or pattern.

The above object is to provide an automobile tire comprising a tread, a sidewall and a bead, wherein the tread is formed by integrally extruding an outer cap tread and an inner undertread having a relatively higher hardness than the cap tread, The under-tread is achieved by the shoulder-reinforced tire, wherein the thickness of both ends corresponding to the shoulder of the cap tread is thicker than the central portion based on the width direction of the tire.

The undertread may include a plate portion formed in a central portion to support the center of the cap tread; and first support portions each protruding from both ends of the plate portion toward the cap tread with respect to the width direction of the tire, and the first support portion to support an area including the shoulder, respectively, forming a curved inclination toward the sidewall from the first support portion It may include a support consisting of a second support that is.

The undertread is molded through a refining process using a composition consisting of carbon black 40Phr, vulcanizer 2.5Phr, and accelerator 1.3Phr based on 60Phr of natural rubber and 40Phr of modified butadiene rubber, and has a hardness of Shore A 70 to Shore A It can be 80.

The undertread may be integrally manufactured by extruding the plate part made of a material of relatively low hardness and the support body made of a material of relatively high hardness.

The support may be manufactured by foam molding a material of high hardness to reduce weight.

The support may further include a first surface protruding from the first support to the center of the plate in parallel with the width direction of the tire, and the first surface may be repeatedly spaced apart in a circumferential direction of the tire. .

The support is further provided with a second surface having a curved shape that is curved from the first surface to the sidewall and is inclined toward the sidewall, and the second surface is repeated between the first surfaces adjacent to each other in the circumferential direction of the tire. can be formed with

The undertread is integrally manufactured by extrusion molding the plate portion made of a material of relatively low hardness and the support made of a material of relatively high hardness, wherein the support is made of a material of high hardness to reduce weight. It can be manufactured by molding.

According to the present invention, since the inner undertread with high hardness, which is integrally extrusion-molded with the outer cap tread, is thicker at both ends corresponding to the shoulder of the cap tread than at the center in the width direction of the tire. As the contact area between the undertread and the cap tread increases, separation or separation of the cap tread from the undertread is effectively prevented and safe driving can be achieved. Accurate vehicle control is possible as the loss of steering force is reduced because solid support is made by the protruding structure of both ends of the undertread. There is an effect that can be fully realized.

1 is a partially cut-away perspective view showing the inside of a shoulder-reinforced tire according to an embodiment of the present invention.
2 and 3 are process diagrams showing a series of processes for manufacturing the tread of FIG.
FIG. 4 is a cross-sectional view illustrating a cross-sectional shape of the tread shown in FIG. 1 .
5 is a partial perspective view illustrating an under tread of a shoulder reinforced tire according to a modified example of the present invention.
6 is a cross-sectional view of a tire provided with a conventional multi-layered tread.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, in describing the present invention, descriptions of already known functions or configurations will be omitted in order to clarify the gist of the present invention.

1 is a partially cut-away perspective view showing the inside of a shoulder reinforced tire according to an embodiment of the present invention, FIGS. 2 and 3 are process diagrams showing a series of processes for manufacturing the tread of FIG. 1, and FIG. 4 is FIG. is a cross-sectional view to show the cross-sectional shape of the tread shown in Fig. 5 is a partial perspective view showing the under-tread of the shoulder reinforced tire according to a modified example of the present invention, and Fig. 6 is a conventional tire equipped with a multi-layered tread. is a cross-sectional view of

Top (top), bottom (bottom), left and right (side or lateral), front (front, front), back (back, back), etc., which refer to directions in the description and claims of the invention, are not used for limiting rights. For convenience of explanation, it is determined based on the relative positions between the drawings and the configuration, and the three axes may be rotated to correspond to each other and changed, except when specifically limited otherwise.

The shoulder-reinforced tire 100 according to the present invention effectively prevents separation or separation of the cap tread 110 from the under-tread 120 by increasing the contact area between the under-tread 120 and the cap tread 110, The stability of the steering force is improved through solid support for the shoulder 112 pressed by centrifugal force during left-right rotation of the vehicle or steering wheel steering, while the cap tread of sufficient thickness to fully realize the characteristics according to the material or pattern ( 110) is a structurally devised invention to be formed.

In order to specifically implement the above-described functions or actions, the shoulder reinforced tire 100 according to the present invention includes a cap tread 110 and an under tread 120 as shown in FIGS. 1 to 5 . It may be configured to include a tread, belt 40, carcass 50, sidewall 20 and bead 30 of a multi-layer structure.

Here, the belt 40 is a component supporting the lower portion of the tread to maintain a flat shape, and the carcass 50 is disposed over the entire area of the tire 100 to support the internal air pressure and form the skeleton of the tire 100 . element, the sidewall 20 is a component that protects the side surface of the tire 100 and enables repeated contraction and expansion of the tire 100, and the bead 30 is a component that is sealed and fastened to the rim of the wheel .

However, since each of the above-described configurations is not related to the gist of the present invention and is sufficient to be understood as a similar technology that is not differentiated from a known technology, a detailed description thereof will be omitted, and the multilayer, which can be said to be the gist of the present invention, is omitted. The tread of the structure will be described in detail below.

As shown in FIGS. 1 and 4 , the tread constituting the shoulder reinforced tire 100 according to the embodiment of the present invention is the outer cap tread 110 in direct contact with the road surface when the tire 100 rotates. And, it can be made by integrally extruding the undertread 120 that supports the cap tread 110 from the inside, which is manufactured to have a relatively high hardness compared to the cap tread 110 .

Although not specifically expressed in FIG. 1, the cap tread 110 includes various patterns and grooves provided in the central part for drainage, heat generation, or traction with the road surface, and sidewalls ( 20), it may be formed of a shoulder 112 that dissipates heat from the tire 100 while driving and forms a gripping force according to steering.

Here, briefly looking at the manufacturing process of the tire 100, first, the cap tread 110 is added to the raw rubber R1, R2 of natural and synthetic materials in the refining process as shown in FIG. 2 with additives (CB, V, A). ), etc. are first processed in the form of a flat rubber sheet 110' for cap tread through a mixer 5 that mixes them in various combinations.

And the primary processed rubber sheet for the cap tread 110 ′ is an extruder 6 together with the primary processed rubber sheet 120 ′ for the under tread at a separate composition ratio in the extrusion process as shown in FIG. 3 . The tread of the present invention is formed by being input to the , each extruded into a predetermined shape and integrally molded.

Then, the tread, which is extruded and wound on the roller 7, is cut to a required length and then combined with the belt 40, carcass 50, bead 30, etc. The finished tire 100 is constituted by finally forming the pattern, groove, shoulder 112, and the like.

According to an embodiment of the present invention, the cap tread 110 may be manufactured in various ways by known techniques because a specific shape, a compounding composition or ratio of the raw material d, etc. are not particularly limited.

However, as will be described later, the cap tread 110 is manufactured to have a higher modulus of elasticity than the under tread 120 of the present invention, that is, a lower hardness.

The undertread 120 of the present invention is disposed on the inside of the cap tread 110 like the conventional undertread 14 shown in FIG. 6 to basically support the cap tread 110 at the top, while the curved surface of the vehicle It is a component provided to more firmly support the shoulder 112 during rotation or steering wheel steering.

As described above, the solid support of the undertread 120 with respect to the shoulder 112 is basically as shown in FIGS. 1 and 4, the shoulder 112 of the cap tread 110 based on the width direction of the tire. This is achieved by forming the thickness of both end portions corresponding to each of the under tread 120 thicker than the central portion of the under tread 120 .

Specifically, the undertread 120 according to the present invention includes a support 122 including a plate portion 121, a first support portion 122a, and a second support portion 122b as shown in FIGS. 1 to 4 . As shown in FIG. 5 , the embodiment including the first surface 122c and the second surface 122d may be implemented as modified examples further including the first surface 122c and the second surface 122d in the configuration of the embodiment, respectively.

First, the plate part 121 constituting the undertread 120 according to the embodiment of the present invention is a component formed in the central part to support the central part of the cap tread 110, and as will be described later, the cap tread ( 110) is recessed differently from the support 122 protruding toward the side and may be formed in a flat plate shape.

Due to the recessed structure of the plate portion 121, the central portion of the cap tread 110, where the tread pattern and groove are formed in the vulcanization process, is formed with a sufficient thickness, so that the intended pattern and groove can be freely implemented without restriction on the depth. to be able to design.

In addition, since the central portion of the cap tread 110 is formed to a sufficient thickness due to the recessed structure of the plate portion 121, a thin thickness between the groove formed in the conventional cap tread 12 and the conventional undertread 14 may be caused. Partial separation or peeling of the block of the conventional cap tread 12 can be effectively prevented (see FIGS. 4 and 6).

The support body 122 is provided on the edge of the cap tread 110 on the cross-sectional view of the cap tread 110 based on the width direction of the tire, that is, at both ends to firmly support the area of the shoulder 112 that is pressed during the left and right rotation of the vehicle. On the other hand, it is a structurally devised component to prevent separation of the cap tread 110 from the under tread 120 by increasing the bonding area between the cap tread 110 and the under tread 120 .

The support 122 may be formed by protruding from both ends of the above-described plate part 121 in a curved shape corresponding to the shoulder 112 of the cap tread 110, and specifically shown in FIGS. 1 and 4 . As in the illustrated embodiment, it may be configured to include a first support part (122a) and a second support part (122b).

The first support portion 122a is a component that serves as a stumbling block for regulating the central portion of the cap tread 110 where the pattern and grooves are formed so as not to deviate from the left and right in the width direction of the tire. ) may be formed to protrude upward from both ends toward the cap tread 110 .

At this time, the first support portion 122a is approximately 60% (eg, 6 mm) to 70% of the maximum cross-sectional thickness (eg, 10 mm) of the tread including the cap tread 110 and the under tread 120 . (For example, it is preferable to protrude to a thickness corresponding to 7mm).

The reason why the degree of protrusion of the first support part 122a is limited as above is that when the thickness of the first support part 122a is less than 60% of the maximum cross-sectional thickness of the tread, the shoulder 112 area of the cap tread 110 This is because the thickness of the cross-section is thickened, so that a phenomenon of being pressed occurs without being fully supported by the support 122 during rotational driving of the vehicle.

In addition, since the cross-sectional thickness of the shoulder 112 region of the cap tread 110 is excessively thin when the first support portion 122a has a thickness exceeding 70%, the shoulder 112 itself exerted by elasticity during steering. This is because it is difficult to expect grip performance and the like, and there is a problem in that durability of the shoulder 112 area becomes weak.

The second support portion 122b is a component provided to support the region including the shoulder 112 from the lower portion rather than the central portion of the cap tread 110, and is provided from both ends of the plate portion 121, respectively, as described above. The protruding first support portion 122a may be inclined in a curved shape toward the sidewall 20 by a length corresponding to the region including the shoulder 112 .

Here, in the second support portion 122b, the region including the shoulder 112 positioned thereon is approximately 30% (eg, 3 mm) to 40% (eg, 3 mm) with respect to the maximum cross-sectional thickness (eg, 10 mm) of the tread. In order to maintain a thickness corresponding to 4 mm), it is formed in a curved shape corresponding to this, which can be understood by the reason for limiting the degree of protrusion of the first support part 122a above.

As described above, the under tread 120 including the support 122 including the plate portion 121 and the first and second support portions 122a and 122b is, as shown in Table 1 below, a natural rubber (R1). ) Based on 60 Phr and modified butadiene rubber (R2) 40 Phr (total 100 Phr), a composition consisting of carbon black (CB) 40 Phr, vulcanizing agent (V) 2.5 Phr, and accelerator (A) 1.3 Phr as a material is shown in FIG. After being first molded into the rubber sheet 120' for under-tread having a hardness of about Shore A 70 to Shore A 80 through the refining process as shown, it is formed into a predetermined shape in the extrusion process as shown in FIG. can be molded.

Here, Phr unit is an abbreviation of Parts per hundred resin, indicating the weight (eg. kg) of the additive added per 100 weight (eg. kg) of the polymer. When 1 kg of the additive is mixed with 100 kg of the polymer, the additive becomes 1 Phr.

And the modified butadiene rubber (R2) in the composition of the undertread 120 is a VCR617 product commercially available from UBE Industries, which has a density of 0.910 g/cc, a volatility of 0.30%, and a Mooney viscosity of 62.0 MU (ML1). +4, 100℃), specific gravity is 0.91%, ash content is 0.15%, and n-Hexane insoluble has the same physical property information as 17wt%.

In addition, in the case of the undertread 120 that is smaller than the hardness range of Shore A 70 to Shore A 80, it is difficult to expect improvement in solid steering performance due to insufficient support for the shoulder 112 of the cap tread 110, whereas In the case of the undertread 120 larger than the hardness range of Shore A 70 to Shore A 80, it becomes difficult to realize a smooth driving feeling, so it is limited to the above range.

Undertread composition (unit Phr) comparative example Example natural rubber 80 60 Solution Polymerized Styrene-Butadiene Rubber 20 - Modified Butadiene Rubber (VCR617) - 40 carbon black 48 40 silica - - oil 4 - vulcanizing agent 3.0 2.5 accelerant 1.4 1.3 Hardness (Shore A) 64 70 300% Modulus (kgf/cm2) 107 145 Tg -45 -45 0℃ tanδ 0.132 0.131 60℃ tanδ 0.120 0.081

The above [Table 1] summarizes the physical properties measured after manufacturing the undertread 120 by dividing the conventional comparative examples and examples having different compositions. According to this [Table 1], the present invention The undertread 120 according to the embodiment has the following characteristics in comparison with the conventional comparative example.

First, the hardness of Example is Shore A 70 corresponding to the heel, which is larger than the cap tread of a general tire or Shore A 64 of Comparative Example, and in the case of 300% Modulus, a measure related to elasticity, Example is 145, which is larger than that of Comparative Example. It can be seen that there is a characteristic that there is little deformation.

That is, when the under tread 120 according to the embodiment of the present invention is applied to the tire 100, stronger support for the shoulder 112 of the cap tread 110 is possible due to stronger hardness and inelasticity compared to the prior art. An improvement in tire steering force and precise control of the vehicle can be expected.

Second, among the viscoelastic properties of rubber, in the case of the dynamic loss coefficient (tanδ) at 0°C, which is a measure related to wet braking performance, and the dynamic loss factor (tanδ) at 60°C, which is a measure related to rotational resistance, It can be seen that the rotational resistance of the example is specially reduced because 60°C tanδ is 0.081, which is significantly smaller than that of the comparative example.

That is, when the under tread 120 according to the embodiment of the present invention is applied to the tire 100, the rotational resistance of the tire itself is reduced due to a tanδ value of 60° C., which is smaller than that of the prior art, so that fuel efficiency performance is improved from the viewpoint of the tire. This can be expected, and since the ratio of (0°C tanδ)/(60°C tanδ) is increased compared to the prior art, it can be understood that wet braking performance and fuel economy performance are simultaneously improved from the viewpoint of the tire.

Meanwhile, unlike described above, the plate part 121 constituting the undertread 120 and the support body 122 including the first and second support parts 122a and 122b may be made of materials having different hardnesses, respectively. .

Specifically, the plate portion 121 constituting the undertread 120 is made of a material of relatively low hardness, while the support 122 composed of the first and second support portions 122a and 122b is made of a material of relatively high hardness. Then, it can be manufactured integrally by bonding the plate part 121 and the support body 122 of different hardness through the extrusion molding method.

As an example, the plate part 121 is made of a type 1 rubber sheet having a hardness of approximately Shore A 64 through the refining process as shown in FIG. 2 using the composition of the comparative example mentioned in [Table 1] as a material. can

And the support 122 is based on 60 Phr of natural rubber (R1) and 40 Phr of modified butadiene rubber (R2), which are the compositions of the above-described embodiments mentioned in [Table 1] (total 100 Phr), carbon black (CB) 40 Phr, and a vulcanizing agent Using a composition consisting of (V) 2.5Phr and accelerator (A) 1.3Phr as a material, a type 2 rubber sheet having a hardness of about Shore A 70 can be manufactured through the refining process as shown in FIG. 2 .

At this time, the support 122 made of a material having a relatively high hardness compared to the plate portion 121 may be manufactured through foam molding to which a predetermined foaming method is applied during the refining process, which is a support 122 having a thickness. This is to reduce the weight imbalance with the plate portion 121 by reducing its own weight, while allowing rotational resistance to be evenly distributed throughout the undertread 120 .

Finally, the support 122 and the plate portion 121 of different hardness, which have been previously fabricated as described above, may be respectively input to the extrusion process as shown in FIG. 3 to be integrated into one undertread 120 .

Of course, the plate part 121 and the support body 122 of different hardness are injected into a predetermined mold over time with the composition as above, not through the extrusion process as described above, to form one undertread 120 . may be made with

As described above, due to the implementation of the embodiment according to the present invention, the solid support for the shoulder 112 pressed by centrifugal force during left-right rotation of the vehicle or steering wheel steering is firmly supported by the protruding structure of both ends of the under-tread 120. As the loss of steering force is reduced, more accurate vehicle control and stable driving are expected.

On the other hand, as shown in FIG. 5 , the support 122 of the undertread 120 according to a modified example of the present invention has a first surface 122c and a second surface on the first and second support parts 122a and 122b. (122d) is further added to form a shape of a repeated sawtooth wave structure as a whole when viewed in a plan view.

Here, the first surface 122c and the second surface 122d further increase the contact area with the cap tread 110 positioned above the first and second support parts 122a and 122b together with the above-described first and second support parts 122a and 122b to increase mutual coupling force. By improving and further suppressing the separation or peeling of the cap tread 110 in all (front, back, left, right) directions, while supporting the shoulder 112 areas on both sides of the cap tread 110 bonded to the upper portion in a sawtooth structure, respectively, It performs a function of indirectly realizing features such as a lug type tire that is mainly mounted on a truck or a bus.

The above-described lug-type tire, as already known, has excellent driving force, braking force, and heat dissipation, but has disadvantages such as rotational resistance and driving noise. When the first and second surfaces 122c and 122d are implemented on the undertread 120 , regardless of the pattern of the cap tread 110 , various patterns complementing the advantages and disadvantages of the lug-type tire at the level of the undertread 120 . of tires can be manufactured.

In order to implement the above function in detail, the first surface 122c according to the modified example of the present invention is a plate portion parallel to the width direction of the tire in the above-described first support portion 122a, as shown in FIG. 5 . A surface that is formed to protrude toward the center of 121 to face the front or rear of the driving, and may be formed repeatedly spaced apart along the circumferential direction of the tire.

And as shown in FIG. 5 , the second surface 122d according to the modified example of the present invention is a curved surface that is curved from the first surface 122c toward the sidewall 20 and is curved, and is a surface of the tire. It may be formed repeatedly between the first surfaces 122c adjacent to each other in the circumferential direction.

Similar to the above-described embodiment, the under-tread according to a modified example including the plate part 121, the support body 122 including the first and second support parts 122a and 122b and the first and second surfaces 122c and 122d. (120) is a rubber sheet 120' for under-tread having a hardness of about Shore A 70 through a refining process as shown in FIG. After secondary molding, it may be molded into a shape of a sawtooth wave structure in an extrusion process as shown in FIG. 3 .

In addition, unlike the above, the plate part 121 constituting the undertread 120 according to the modified example, the support body 122 including the first and second support parts 122a and 122b and the first and second surfaces 122c and 122d. may be made of materials of different hardness, respectively.

That is, the plate portion 121 constituting the undertread 120 is manufactured with a relatively low hardness by using the same composition as in the comparative example mentioned in [Table 1] as a material, while the first and second support portions 122a and 122b) And the support 122 composed of the first and second surfaces 122c and 122d is made of the same composition as in the embodiment mentioned in [Table 1] as a material and has a relatively high hardness, and then the plate part made of different hardness As in the above-described embodiment, the 121 and the support 122 are integrally manufactured through the extrusion method.

Even at this time, the support 122 composed of a material having a relatively high hardness compared to the plate portion 121 can be manufactured through foam molding to which a predetermined foaming method is applied during the refining process, which is the support 122 having a thickness. ) to reduce the weight imbalance with the plate portion 121 by reducing its own weight, while allowing rotational resistance to be evenly distributed throughout the undertread 120 .

As described above, the support 122 and the plate portion 121 of different hardness, which have been previously manufactured according to the modified example, are respectively input to the extrusion process as shown in FIG. ) and at the same time joined to the pre-fabricated cap tread 110 to form a single integrated tread.

In the foregoing, specific embodiments of the present invention have been described and shown, but it is common knowledge in the art that the present invention is not limited to the described embodiments, and that various modifications and variations can be made without departing from the spirit and scope of the present invention. It is self-evident to those who have Accordingly, such modifications or variations should not be individually understood from the technical spirit or point of view of the present invention, and modified embodiments should be said to belong to the claims of the present invention.

5: Mixer 6: Extruder
7: Roller 10: Tread
12: conventional cap tread 14: conventional under tread
20: sidewall 30: bead
40: belt 50: carcass
60: inner liner R1, R2: natural rubber, modified butadiene rubber
CB: carbon black V,A: vulcanizing agent, accelerator
100: shoulder reinforced tire
110: cap tread 110': rubber sheet for cap tread
112: shoulder 120: under tread
120': rubber sheet for undertread 121: plate part
122: support 122a: first support
122b: second support 122c: first surface
122d: second side

Claims (8)

In the automobile tire consisting of a tread, a sidewall and a bead,
The tread is made by integrally extruding an outer cap tread and an inner under tread having a relatively higher hardness than the cap tread,
The under tread is formed so that both ends corresponding to the shoulder of the cap tread have a thickness greater than that of the central portion, based on the width direction of the tire;
The under tread is
a plate portion formed in the central portion to support the center of the cap tread; and
The first support portion protruding from both ends of the plate portion toward the cap tread, respectively, based on the width direction of the tire, and the first support portion to support the area including the shoulder, respectively, is formed in a curved shape toward the sidewall from the first support portion Comprising a support consisting of a second support,
The support is
A first surface protruding toward the center of the plate portion in parallel with the width direction of the tire in the first support portion is further provided;
The first surface is a shoulder-reinforced tire, characterized in that it is repeatedly spaced apart along the circumferential direction of the tire. delete According to claim 1,
The under tread is
Based on 60Phr of natural rubber and 40Phr of modified butadiene rubber, it is molded through a refining process using a composition consisting of carbon black 40Phr, vulcanizer 2.5Phr, and accelerator 1.3Phr, and has a hardness of Shore A 70 to Shore A 80. shoulder reinforced tire. According to claim 1,
The under tread is
A shoulder-reinforced tire, characterized in that the plate portion made of a material of relatively low hardness and the support body made of a material of relatively high hardness are extruded and integrally manufactured. 5. The method of claim 4,
The support is
Shoulder-reinforced tire, characterized in that it is manufactured by foam molding a material of high hardness to reduce weight. delete According to claim 1,
The support is
A second surface having a curved shape that is inclined and curved from the first surface toward the sidewall is further provided,
and the second surface is repeatedly formed between the first surfaces adjacent to each other along the circumferential direction of the tire. 8. The method of claim 7,
The under tread is
The plate portion made of a material of relatively low hardness and the support body made of a material of relatively high hardness are extrusion-molded to be integrally manufactured,
The support is
Shoulder-reinforced tire, characterized in that it is manufactured by foam molding a material of high hardness to reduce weight.

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