CN211222914U

CN211222914U - Load-carrying tire with resistance to ditch bottom cracking

Info

Publication number: CN211222914U
Application number: CN201921602378.3U
Authority: CN
Inventors: 张春生; 俞惠友; 王学瑞; 侯丹丹
Original assignee: Zhongce Rubber Group Co Ltd
Current assignee: Zhongce Rubber Group Co Ltd
Priority date: 2019-09-25
Filing date: 2019-09-25
Publication date: 2020-08-11
Anticipated expiration: 2029-09-25

Abstract

The application relates to a truck tire, in particular to a truck tire with resistance to ditch bottom cracking. The tire crown part of the tire comprises a tire tread, a No. 1 belted layer, a No. 2 belted layer, a No. 3 belted layer, two layers of 0-degree belted layers, a tire body and a rubber shoulder pad, wherein at least 3 grooves are arranged on the surface of the tire tread, a tire shoulder pad rubber is arranged between the belted layer and the tire body, the tire crown part further comprises a tire body rubber sheet, the tire body rubber sheet is arranged between the tire body and the tire shoulder pad rubber, the distance b between the No. 1 belted end point and the inner end point of the tire shoulder pad rubber is 5-10 mm, the distance c between the inner end point of the tire shoulder pad rubber and the end point of the tire body rubber sheet is 5-10 mm, the covered edge rubber width of the No. 1 belted layer is 24-28 mm, the thickness is 0.5-0.8 mm, the width of the tire body rubber sheet. This application improves the tear resistance at the bottom of the tire ditch from tire structural design's angle, extension tire life.

Description

Load-carrying tire with resistance to ditch bottom cracking

Technical Field

The application relates to a truck tire, in particular to a truck tire with resistance to ditch bottom cracking.

Background

Groove bottom cracking is one of the major service damage problems complained by the heavy duty tire market, and in particular, the groove cracking phenomenon occurring at the early stage of service is a high complaint rate. The load-carrying tire has many causes of cracking at the bottom of the groove, mainly including flexural deformation, stress cracking, crack growth due to trauma, and the like, and the causes of cracking at the bottom of the groove of the tire have also begun to be diversified according to the development of automobile technology and the complexity of use conditions.

For example, in recent years, buses generally go through three different development stages, namely, diesel vehicles, hybrid vehicles and pure electric vehicles, and particularly, after the hybrid buses are switched to be pure electric vehicles, the torque of the vehicles is increased, the driving force is increased, and accordingly, the market use of tires is changed. Because the tire crown is of an arc design, the diameter difference exists between the center of the tire crown and the shoulder position, when the tire rolls in the circumferential direction, although the rotation angular velocity of each point on the tire tread is the same, the tangential velocity of a grounding point is different, namely, the circumferential shearing force exists between adjacent ribs, particularly between shoulder ribs. In addition, with the increase of the torque of the pure electric vehicle, the circumferential shearing force between the ribs is increased, the shearing stress strain at the bottom of the pattern groove is intensified, and the risk of tire groove cracking is increased.

Therefore, the conventional method for improving the crack cannot adapt to the development of the truck technology and the change of the market situation, and the development of a novel crack-resistant design method for the load is urgent.

The Chinese invention patent application (publication number: CN107379895A, published 2017.11.24) applied by the applicant discloses a nylon crown strip reinforced all-steel radial tire, the crown structure of the tire is a zero-degree belt ply structure, and the tire comprises a No. 1 belt ply, a No. 2 belt ply, a No. 3 belt ply, a zero-degree belt ply, an inner liner, a tire body, cushion rubber and a tire surface; the crown structure of the tire also comprises a nylon crown band, the nylon crown band adopts a narrow nylon impregnated cord fabric, and the nylon crown band is positioned above a No. 1 belt ply or a No. 2 belt ply of the tire or above a No. 3 belt ply and a zero-degree belt ply simultaneously; the nylon crown tape is spirally wound to form a single layer and is spirally wound to form a single-layer or multi-layer circumferential reinforcing layer. This patent utilizes characteristics such as polyamide fibre crown band layer high breaking strength, high dead load elongation, low creep rate, combines the advantage of traditional zero degree belted layer simultaneously, guarantees the zero degree belted layer and tightly ties the nature under high-speed running state, avoids belted layer to produce fatigue failure and themogenesis destruction because of stress strain effect, effectively solves groove bottom crack, belted layer delaminating, tears the scheduling problem. This patent has adopted the polyamide fibre crown band strip to form the individual layer through spiral winding and has formed individual layer or multilayer circumference enhancement layer through spiral winding, and the structure is comparatively complicated, is unfavorable for production.

Disclosure of Invention

In order to solve the technical problem of groove bottom cracking, the invention aims to provide a heavy-duty tire with groove bottom cracking resistance from the perspective of structural design, so as to solve the problem of groove cracking possibly occurring in the use process of the tire and ensure the service life and the performance of the tire.

In order to achieve the above object, the present application adopts the following technical solutions:

the utility model provides a load-carrying tire that resistant ditch bottom splits, the child crown position of this tire includes tread, No. 1 belted layer, No. 2 belted layer, No. 3 belted layer, two-layer 0 degree belted layer 0, matrix and rubber shoulder pad, and the tread surface is provided with 3 decorative furrows at least, the shoulder pad glue set up in belted layer and matrix between, its characterized in that, the child crown position still includes the matrix film, the matrix film sets up between matrix and shoulder pad glue, and No. 1 belted layer endpoint is 5~ 10mm with the interior endpoint distance b of shoulder pad glue, and the interior endpoint distance c of shoulder pad glue is 5~ 10mm with the matrix film, and No. 1 belted layer taping glue width is 24~28mm, and thickness is 0.5~0.8mm, and matrix film width is 100~110mm, and thickness is 0.5~0.8 mm.

Preferably, the widest belt layer No. 2 width is extended onto the normal line of the carcass passing through the shoulder apex of the running surface as a reference line.

Preferably, the difference a between the No. 1 belt layer and the No. 2 belt layer is 12-15 mm.

Preferably, the distance d between the groove bottom and the inner end point of the 0-degree belt layer 0 is ≧ 5 mm.

Preferably, the width of the No. 1 belt layer edge-covering rubber is 25mm, the thickness is 0.6mm, the width of the carcass rubber sheet is 105mm, and the thickness is 0.6 mm.

Preferably, the crown mid-thickness e is equal to the tread thickness e' at the crown gutter location.

Preferably, the ratio of the tire shoulder thickness f to the tire crown middle thickness e is 1.15-1.25.

Compared with the prior art, the beneficial effect of this application: through the structural design of the tread part, the uniform transition of the thickness of the tread section and the difference level of the inner end point of the cushion rubber and the pattern groove bottom are ensured, so that the tire is ensured to be uniformly expanded at the crown position before and after inflation by maintaining the balance of the outline of the tire body, the deformation of the shoulder pattern side groove is reduced, the stress strain of the groove bottom is reduced, the tear resistance of the tire groove bottom is improved from the angle of the structural design of the tire, and the service life of the tire is prolonged.

Drawings

Fig. 1 is a schematic view of the tire structure of the present application.

Fig. 2 is a diagram showing groove bottom crack growth.

FIG. 3 is a schematic representation of the change before and after inflation of the carcass profile.

Detailed Description

The following describes an embodiment of the present application with reference to the drawings.

FIG. 1 is a schematic view of a tire structure according to one embodiment of the present application. The heavy duty tire of the present application is suitable for use as a bus tire for a bus, but the present application is not limited to such a tire type, and is also applicable to a long-distance bus, a standard load type heavy duty tire, and the like.

The tyre crown part mainly comprises a tyre surface 5, a No. 1 belted layer 1, a No. 2 belted layer 2, a No. 3 belted layer 3, two layers of 0-degree belted layers 0, a tyre body 4, a tyre shoulder cushion rubber 6 and a tyre body rubber sheet 7, wherein the surface of the tyre surface 5 is at least provided with 3 grooves. Wherein, the shoulder pad rubber 6 is arranged between the belted layer and the tire body 4, and the tire body rubber sheet 7 is arranged between the tire body 4 and the shoulder pad rubber 6.

The width of the widest No. 2 belt layer 2 extends to the normal line of the carcass 4 passing through the apex of the shoulder of the running surface.

The difference a between the No. 1 belted layer and the No. 2 belted layer is 12-15 mm.

The distance b between the end point of the No. 1 belted layer and the inner end point of the shoulder wedge 6 is 5-10 mm.

The distance c between the inner end of the shoulder pad rubber 6 and the end of the tire body rubber sheet 7 is 5-10 mm.

The width of the No. 1 belted layer edge covering glue is 25mm, and the thickness is 0.6 mm.

The width of the rubber sheet arranged on the tire body 4 is 105mm, and the thickness of the rubber sheet is 0.6 mm.

The distance d between the groove bottom of the pattern and the inner end point of the zero-degree belt is not less than 5 mm.

The crown intermediate thickness e is equal to the tread thickness e' at the crown gutter position.

The ratio of the tire shoulder thickness f to the tire crown middle thickness e is 1.15-1.25.

Comparative example 1

The distance b between the No. 1 belt end point and the inner end point of the shoulder wedge 6 was set to 20mm, and the corresponding value of c was also adjusted to 20 mm. The tire body rubber sheet 71 number belt layer edge covering rubber is set to be 30mm in width and 1mm in thickness. The rubber sheet placed on the carcass 4 was set to be 105mm wide and 1.0mm thick, and the rest was the same as in the present example.

Comparative example 2

And (3) additionally attaching 45 x 2.0 rubber sheets to the tire body rubber sheet 7 below the tire shoulder cushion rubber 6, controlling the ratio of the tire shoulder thickness f to the tire crown middle thickness value e to be 1.3, and controlling the difference between the additionally attached rubber sheets and the inner end points of the tire shoulder cushion rubber 6 to be 5-10 mm, wherein the rest is the same as the embodiment of the application.

Fig. 2 is a diagram showing groove bottom crack growth. The occurrence pattern of the tire groove bottom crack is mainly subjected to stress strain in three directions, wherein the groove crack (usually occurring in a gutter) caused by the lateral expansion force can be pre-evaluated by measuring the groove width change value after the tire is inflated. Cracks caused by the circumferential shear force and the radial stress generally need to be judged by observing the form of the groove cracks after actual use. Therefore, the resistance of the tire to cracking can be improved to some extent or the risk of cracking of the tire from the viewpoint of structural design can be reduced by reducing the groove width variation after inflation, that is, reducing the deformation of the grooves. In addition, the distance d between the pattern groove bottom and the zero belt inner end point is also used for avoiding the belt end point from falling on the groove bottom, so that the stress concentration of the groove bottom is caused, and the risk of groove cracking is increased.

Fig. 3 is a diagram for supplementary explanation of the deformation of the tire outer contour caused by the internal pressure tension deformation of the tire inner contour 4 after inflation, and for the case of uneven inflation, the deformation of the shoulder is too large, and the deformation degree of the side groove is directly influenced, and the stress strain of the groove bottom is increased.

In order to evaluate whether the tire has the groove crack risk, the tire of the invention example and the comparison example is pre-evaluated by measuring the design groove width change value of the tire and the mold after the tire is inflated at the standard pressure, and the smaller the value is, the better the value is.

Table 1 shows the test data of the present application example:

table 2 is comparative example 1 data:

table 3 comparative example 2 data:

comparing tables 1 and 2 above, the present application has a good effect on the improvement of groove width variation, and comparing tables 1 and 3 can find that the tire shoulder design thickening can have a certain effect on groove width variation, but the thicker the tire shoulder, the higher the heat generation, which can reduce the tire service life and the cost can also be directly increased.

In order to further verify and evaluate the effect of the method for preventing the ditch cracks, the method carries out actual loading road test on the tire of the example and the tire of the comparative example, the three embodiments are respectively installed on three pure electric buses (front 2 and rear 4) with the same model and the same running route, and the ditch crack resistance performance is actually evaluated by regularly checking whether cracks exist at the bottom of the tire pattern ditch and the sizes of the cracks, and the evaluation grades are defined as follows:

a level: the bottom of the groove has no crack.

B stage: has fine cracks with the width less than or equal to 1mm and the length less than or equal to 5mm and slight furrow cracks.

C level: cracks with the width more than 1mm and less than or equal to 5mm and the length more than 5mm and less than or equal to 10mm exist, and medium furrow cracks exist.

D stage: cracks with a width > 5mm and a length > 10mm, severe gouges were present.

In order to ensure safety, after the crack develops into a crack of the moderate groove, the tire is disassembled from the bus to stop the evaluation test.

Table 4 shows the road test evaluation results:

the previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present disclosure, including any person skilled in the art, having the benefit of the present disclosure. Various modifications to these embodiments will be readily apparent to those skilled in the art. The general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A ditch bottom crack resistant heavy duty tire, the tire crown part of the tire comprises a tire tread (5), a No. 1 belted layer (1), a No. 2 belted layer (2), a No. 3 belted layer (3), two layers of 0-degree belted layers (0), a tire body (4) and tire shoulder cushion rubber (6), at least 3 grooves are arranged on the surface of the tire tread (5), the tire shoulder cushion rubber (6) is arranged between the belted layer and the tire body (4), the tire crown part is characterized by also comprising a tire body rubber sheet (7), the tire body rubber sheet (7) is arranged between the tire body (4) and the tire shoulder cushion rubber (6), the distance b between the end point of the No. 1 belted layer (1) and the inner end point of the tire shoulder cushion rubber (6) is 5-10 mm, the distance c between the inner end point of the tire shoulder cushion rubber (6) and the end point of the tire body rubber sheet (7) is 5-10 mm, the tire body belt layer (1) has the edge rubber width of 24-28 mm, the thickness of 0.5-0, the thickness is 0.5 to 0.8 mm.

2. A heavy duty tire resistant to chipping according to claim 1, wherein the widest belt layer No. 2 (2) width is extended on the normal line of the carcass (4) passing through the shoulder apex of the running surface as a reference line.

3. The heavy duty tire resistant to the chipping under load as claimed in claim 1, wherein a difference a between the No. 1 belt layer (1) and the No. 2 belt layer (2) is 12 to 15 mm.

4. The tire for heavy load resistant to groove bottom cracking according to claim 1, wherein the distance d between the groove bottom and the inner end of the 0-degree belt layer (0) is not less than 5 mm.

5. The heavy duty tire resistant to the chipping of claim 1, wherein the belt layer No. 1 (1) has a bead filler width of 25mm and a thickness of 0.6mm, and the carcass ply (7) has a width of 105mm and a thickness of 0.6 mm.

6. A heavy duty tire resistant to undertread cracking as claimed in claim 1 wherein the crown intermediate thickness e is equal to the tread thickness e' at the crown sipe location.

7. The heavy duty tire resistant to the chipping and cracking as claimed in claim 1, wherein a ratio of a shoulder thickness f to a crown intermediate thickness e is 1.15 to 1.25.