JPH04163215A - Pneumatic tire - Google Patents

Abstract

PURPOSE:To heighten cut piercing resistance and prevent the damage of a carcass caused by a crack such as a cut so as to improve the durability of a tire by providing a protecting layer extended from around the outer end of a belt layer along a buttress part and a side wall part. CONSTITUTION:A carcass 7 is laid between the bead parts 3, 3 of a radial tire 1. This carcass 7 is provided with the folded part 7B of a bead core 2 on each end of a body part 7A passing a side wall part 4 from a tread part 5 down to the bead part 3. In this case, the carcass 7 is provided, on its outside, with a protecting layer 10 as well as a belt layer 9. The protecting layer 10 is formed of one continuous reinforcing ply provided with a side protecting part 16 extended outside the carcass 7 from between the vicinity of the tire axial outer end 9a of a belt 9 and the carcass 7 along a buttress part 18 and a side wall 4 toward the radial inner side of the carcass 7. The inner end height H of the protecting layer 10 is set in a range between a position A of 0.7 times as high as the tire sectional height (h) and the flange height FH of a standard rim.

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention can significantly extend the service life of tires by increasing cut penetration resistance in the side regions of tires.
In particular, the present invention relates to a pneumatic tire that can be suitably used for vehicles traveling on rough roads. [Problems to be solved by conventional technology and ideas] For example, radial tires for work vehicles used on rough roads such as civil engineering/construction sites and quarrying sites are prone to sharp rocks, stones, etc. that rise from the road surface. The side area from the buttress section to the sidewall section is susceptible to damage from cuts and other cracks due to the
This suppresses the occurrence of deep cuts that reach directly into the carcass case. Note that such a deep cut causes the carcass cord to break due to the local stress, making it impossible to reuse the cord for tire retreading or the like, thereby significantly shortening the service life. For this reason, conventional efforts have been made to increase the rubber thickness on the side parts, but although this increases the cut penetration resistance to some extent, the effect is extremely insufficient. there were. The present invention is based on the provision of a protective layer that extends outside the carcass from near the outer edge of the belt layer along the buttress and sidewall sections to effectively prevent cuts that occur in the side area of the tire from reaching the carcass. The purpose of the present invention is to provide a pneumatic tire that can prevent this problem, enable tire retreading, and greatly improve the total life of the tire. [Means for Solving the Problems] In order to achieve the above object, the present invention provides a structure in which the inner side of the tire is provided around the bead core of the bead portion at both ends of the main body portion from the tread portion through the sidewall portion and the bead portion. The carcass has a bias structure made of multiple plies with a folded part that is folded back outward from the tire, and a belt layer disposed on the outside of the carcass and inside the tread part. protection consisting of a reinforcing ply with protective cords arranged at an angle of at least 90 degrees and at an angle of 90 degrees or less, and extending radially inward from the outside of the carcass along the sidewall section from near the outer end of the belt layer in the axial direction of the tire, through the buttress section, and along the sidewall section. While providing the layer, the inner end height H of the protective layer, which is the radial length from the baseline of the bead portion inside the protective layer, is set from a position 0.7 times the cross-sectional height h of the tire to a standard rim. This is a pneumatic tire with a flange height (FH) of up to . [Function] In the tire of the present invention configured as described above, the carcass in the side region is covered and protected by the protective layer, so that the local stress caused when a deep cut is made in the side region acts on the carcass. damage to the carcass cord can be effectively prevented. - In addition, the protective layer can prevent shallow cuts from growing into the carcass due to repeated deformation of the tire, so it can also prevent carcass cord damage and ply peeling caused by moisture seeping in through the cuts. In combination with the above-mentioned direct improvement in cut penetration resistance, the total life of the tire can be greatly improved. [Example] An example of the present invention will be described below based on the drawings. In the figure, a radial tire 1 includes a bead portion 3 through which a bead core 2 passes, a sidewall portion 4 that is continuous with the bead portion 3 and extends outward in the tire radial direction, and a tread portion that connects the outer ends of the sidewall portion 4. 5. Further, between the bead portions 3.3, there are folded portions that are folded back from the inside of the tire to the outside around the bead core 2 at both ends of the main body portion 7A extending from the tread portion 5 through the sidewall portion 4 to the bead portion 3. The carcass 7 in which the carcass 7B has been formed is placed on a rack, and a belt layer 9 and a protective layer 10 are provided on the outside of the carcass 7. The carcass 7 has a bias structure consisting of a plurality of carcass plies with carcass cords arranged at an angle of 30 to 50'' with respect to the tire equator.The casscords are made of aromatic polyamide, nylon, An organic fiber cord such as polyester is used.The body portion 7A of the carcass 7 and the folded portions 7B at both ends thereof are used.
A bead apex 8 made of hard rubber and having a triangular cross section and extending radially outward from the bead core 2 with a gradually decreasing thickness is provided between the bead portions 3 to reinforce the bead portion 3. Further, in this example, the belt layer 9 includes first, second, third, and fourth layers arranged in order from the carcass 7 toward the tread surface.
It has a four-layer structure consisting of belt plies 11, 12, 13, and 14. The widest belt ply, in this example the second belt ply 12, is formed to have a larger ply width in the axial direction of the tire than the other belt plies 11, 18, and 14. Maximum belt width L1 of layer 9 In this example, the ply width of the second belt ply 12 is the tread width T.
By setting W to be 0.80 times or more and 0.99 times or less, the belt layer 9 reinforces the tread portion 5 with a hoop effect over almost the entire goldmine. In this example, the belt plies 11, 12, 13, and 14 are made of strong belt cords with an elastic modulus of 200 kg/mm or more, parallel to each other at an angle of 10' or more and 30' or less with respect to the tire equator. It is an array of code arrays, and the first
The belt plies 11, 12, 13, and 14 of 4 to 4 are arranged in different directions such that the respective belt cords intersect with each other between the plies. In this example, the protective layer 10 extends from between the vicinity of the outer end 9a of the belt layer 9 in the tire axial direction and the carcass 6 to the buttress portion 1.
8 and extends radially inward on the outside of the carcass 7 along the sidewall portion 4 to form a side protection portion 16.
A continuous reinforcing ply 17 is used. The reinforcing ply 17 is a cord array body in which, for example, steel protection cords are arranged at an angle of 30° or more and 90' or less with respect to the tire circumferential direction, and the reinforcing ply 17 is a cord array body in which protective cords made of steel are arranged at an angle of 30° or more and 90' or less with respect to the tire circumferential direction. Cutting through the carcass 7 in the side region leading to the wall part 4 is prevented. In addition, an organic fiber cord such as nylon or polyester can be used as the protective cord, and in such a case, it is preferable that the protective ply 17 is one or more, preferably two or more, and that the protective cords are crossed between the plies. In addition, when a steel cord is used as in this example, it is preferable to use only one reinforcing ply 17 in order to suppress an increase in tire rigidity, and for this purpose, the protective cord angle should be 30 degrees or more as described above. It is set to 90° or less. The inner end height H of the protective layer 10 is 0 of the tire cross-sectional height h.
．． The range is from 7x position A to the standard rim flange height (FH). This improves cut penetration resistance in the side region A where cuts occur frequently. The inner end height H and the tire cross-sectional height h are respectively measured from the baseline l of the bead portion 3 to the inner end 10a of the protective layer 10.
and the radial length from the baseline l to the outermost point 5a of the tread portion 5. Another embodiment of the protective layer 10 is shown in FIG. In the figure, the protective layer 10 is formed from a pair of left and right reinforcing plies 17 and 17 that respectively constitute only the side protection portions 16, and the outer ends of the protective plies 17 are connected to the outer end upper surface of the second belt ply 12 in this example. overlap with. [Specific Example] A tire having the tire structure shown in FIG. 1 was prototyped based on the specifications in Table 1, and the prototype tire was driven on an actual vehicle at a quarry site, and the tire life at that time was compared with that of a conventional tire. As shown in Table 1, the tire of the present invention has improved cut penetration resistance compared to conventional tires, so it can greatly improve the complete wear rate compared to conventional tires. Worn tires can be reused through tire retreading, making it possible to greatly extend their total life. Further, the tire of the present invention can be formed as a tire for a passenger vehicle as well as a tire for a working vehicle on rough roads such as a truck or an excavator. [Function] As stated on paper, the radial tire of the present invention has a protective layer that extends from the vicinity of the outer end of the first bell surface layer along the buttress portion and sidewall portion to improve cut penetration resistance. It is possible to prevent damage to the carcass due to cracks such as cracks, etc., and greatly improve the life of the tire.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing one embodiment of the present invention, and Fig. 2 is a diagram showing another embodiment. 2--Bead core, 8--Bead portion,
4, =,, side wall section, 50.・1. Doo red part, 7-, Carcass, 7A... Body part, 7B... Folded part, 9... Belt layer, 10... Protective layer 1.16 ...Side protection part, 17...Reinforcement ply, ! 1. ·,·Base line. R-,...Rim, FH,...Flange height. Patent applicant Sumitomo Rubber Industries Co., Ltd. agent Patent attorney Tadashi Naemura Figure 2 January 29, 1991 Commissioner of the Japan Patent Office Satoshi Uematsu Relationship with the case of the person making the amendment Patent applicant address Kobe City Chuo 1-1-1-4 Tsutsui-cho, Osaka-ku, Agent address: 4-2-26-6 Nishinakajima, Yodoyo-ku, Osaka, subject of amendment (11 “Title of the invention” column (2) of the specification) Description ``Claims'' column (3) ``Detailed description of the invention'' column in the specification (4) ``Brief description of drawings'' column in the specification) Description (full text amendment)
1 Specification (Full text amended) 1. Name of the invention Pneumatic tire 2. Claim 1 A tire is installed around the bead core of the bead portion at both ends of the main body from the trend portion through the sidewall portion to the bead portion. A carcass with a bias structure made of multiple plies with a folded part that is folded back from the inside to the outside, and a belt layer disposed outside the carcass and inside the tread part. Reinforced terrace with protective cords arranged at an angle of 30 degrees or more and 90 degrees or less□
A protective layer is provided extending radially inward on the outside of the carcass from near the outer end of the belt layer in the tire axial direction to the buttress portion/sidewall portion, while the bead portion inside the protective layer is provided. The height H of the inner edge of the protective layer, which is the length in the radial direction from the baseline, is calculated from the flange height of the standard rim (
Pneumatic tires ranging from F to H). 3. Detailed Description of the Invention [Field of Industrial Application] The present invention can significantly improve the service life of tires by increasing the cut penetration resistance in the side region of the tire.
In particular, it relates to a pneumatic tire that can be suitably used for vehicles traveling on rough roads. [Prior art and problems to be solved by the invention] For example, radial tires for work vehicles used on rough roads at civil engineering/construction sites, quarrying sites, etc. are prone to sharp rocks, stones, etc. that rise from the road surface. The side area from the buttress section to the sidewall section is susceptible to damage from cuts and other cracks due to the
This suppresses the occurrence of deep cuts that reach directly into the carcass case. Note that such a deep cut causes the carcass cord to break due to the local stress, making it impossible to reuse the cord for tire retreading or the like, thereby significantly shortening the service life. For this reason, conventional efforts have been made to increase the rubber thickness on the side parts, but although this increases the cut penetration resistance to some extent, the effect is extremely insufficient. there were. The present invention is based on the provision of a protective layer that extends outside the carcass from near the outer end of the belt layer along the buttress and sidewall parts to effectively prevent cuts occurring in the side region of the tire from reaching the carcass. The purpose of the present invention is to provide a pneumatic tire that can prevent this problem, enable tire retreading, and greatly improve the total life of the tire. [Means for Solving Problem A] In order to achieve the above object, the present invention provides a structure in which the inner side of the tire is provided around the bead core of the bead portion at both ends of the main body portion extending from the tread portion through the sidewall portion to the bead portion. The carcass has a bias structure made of multiple plies with a folded part that is folded back outward from the tire, and a belt layer disposed on the outside of the carcass and inside the tread part. The carcass is made of a reinforcing ply in which protective cords are arranged at an angle of at least 90 degrees and at an angle of at least 90 degrees, and extends from near the outer end of the belt layer in the tire axial direction through the buttress section and along the sidewall section. A protective layer extending radially inward from the outside is provided, and the height of the inner end of the protective layer, which is 0 length in the radial direction from the baseline of the bead portion on the inside of the protective layer, is the tire cross-sectional height. Standard flange height (from the position 0.7 times h)
F, H). It's a tire. [Effect] ′□′
□□゛In the tire of the present invention constructed in this way, the carcass in the side region is covered and protected by the protective layer, so that the local stress caused when a deep cut occurs in the side region is not applied to the carcass. This can effectively prevent damage to the carcass cord.
,,・,1, . Moreover, the protective layer can prevent shallow cuts from growing into the carcass due to repeated deformation of the tire.
It also prevents carcass cord damage and ply peeling caused by moisture entering through the cut, and combined with the above-mentioned direct improvement in strength and tear penetration, it greatly extends the total life of the tire. can be improved. [Example] An example of the present invention will be described below based on the drawings. In the figure, the radial track l includes a bead portion 3 through which the bead core 2 passes, a sidewall portion 4 that is continuous with the bead portion 3 and extends outward in the tire radial direction, and a tread portion 5 that connects the outer ends of the sidewall portion 4. It is equipped with. Further, between the bead portions 3.3, there are folded portions that are folded back from the inside of the tire to the outside around the bead core 2 at both ends of the main body portion 7A extending from the tread portion 5 through the sidewall portion 4 to the bead portion 3. The carcass 7 in which the carcass 7B is formed is placed on a rack, and a belt layer 9 and a protective layer 10 are provided on the outside of the carcass 7. The carcass 7 has a bias structure consisting of a plurality of carcass plies in which carcass cords are arranged at an angle of 30 to 50 degrees with respect to the tire equator. As the Naori-cascord, organic fiber cords such as aromatic polyamide, nylon, and polyester are used. Also, the main body portion 7A of the carcass 7 and the folded portions 7B at both ends thereof.
A bead apex 8 made of hard rubber and having a diagonal cross section and extending outward in the radial direction from the bead core 2 with a gradually decreasing thickness is provided between the bead portions 3 and 3 to reinforce the bead portion 3. Further, in this example, the belt layer 9 includes first, second, third, and fourth layers arranged in order from the carcass 7 toward the trend surface.
It has a four-layer structure consisting of belt plies 11, 12, 13, and 14. Furthermore, the widest belt ply, in this example, the second belt ply 12, is formed so that its ply width in the tire axial direction is larger than each ply width of the other belt plies 11, 13, and 14. Maximum belt width L1 of layer 9 In this example, the ply width of the second belt ply 12 is the tread width T.
The belt layer 9 reinforces the tread portion 5 with a hoop effect extending substantially over the entire length of the belt layer 9, which is set to be 0.80 times or more and 0.99 times or less of W. In this example, the belt plies 11 and I2.13.14 are made of strong belt cords with an elastic modulus of 200 kg/n+'' or more arranged parallel to each other at an angle of 10° or more and 30° or less with respect to the tire equator. The first code array is
The belt plies 11, 12, 13, and 14 of 4 to 4 are arranged in different directions such that the respective belt cords intersect with each other between the plies. In this example, the protective layer IO passes from between the vicinity of the outer end 9a of the belt layer 9 in the tire axial direction and the carcass 6, passes through the baso-res portion 18, and extends along the sidewall portion 4 to the outer side of the carcass 7 in a radius. By extending inward in the direction, the side protection part 1
A continuous reinforcing ply 17 having a shape of 6 is used. The reinforcing ply 17 is a cord array body in which, for example, steel protection cords are arranged at an angle of 30° or more and 90" or less with respect to the tire circumferential direction, and the reinforcing ply 17 is a cord array body in which protective cords made of steel are arranged at an angle of 30 degrees or more and 90" or less with respect to the tire circumferential direction, and is connected from the side guard section 18 to the side window by the side protection section 115. This prevents cuts from penetrating the carcass 7 in the side region leading to the sole portion 4. In addition, an organic fiber cord such as nylon or polyester can be used as the protective cord, and in such a case, it is preferable that one or more protective plies 17 be used. It is desirable that there be two or more protective cords and that the protective cords cross each other between the plies.In addition, when steel cords are used as in this example, the number of reinforcing plies 17 is one to suppress an increase in tire rigidity. In addition, for this purpose, the protective cord angle is set to 30° or more and 90° or less as described above. Also, the inner end height H of the protective layer 10 is set to 0 of the tire cross-sectional height h.
．． The range is from 7x position A to the standard rim flange height (FH). This improves cut penetration resistance in the side region A where cuts occur frequently. The inner end height H and the tire cross-sectional height h are respectively measured from the baseline l of the bead portion 3 to the inner end 10a of the protective layer 10.
It is defined as the radial length from the baseline r to the outermost point 5a of the trend section 5. Another embodiment of the protective layer 10 is shown in FIG. In the figure, the protective layer 10 is formed from a pair of left and right reinforcing plies 17 and 17 that constitute only the side protection portion l6, and the outer end of the protective ply 17 is the outer end of the belt ply 12 in this example. Overlaps the top surface. [Specific Example] A tire having the tire structure shown in FIG. 1 was prototyped based on the specifications in Table 1, and the prototype tire was driven on an actual vehicle at a quarry site, and the tire life at that time was compared with that of a conventional tire. As shown in Table 1, the tire of the present invention has improved cut penetration resistance compared to conventional tires, so it can greatly improve the complete wear rate compared to conventional tires. Worn tires can be reused through tire retreading, making it possible to significantly increase their torque life. Further, the tire of the present invention can be formed as a tire for a passenger vehicle as well as a tire for a working vehicle on rough roads such as a truck or an excavator. [Function] As stated on paper, the radial tire of the present invention has a protective layer extending from near the outer end of the bell layer along the buttress and sidewall portions to improve cut penetration resistance, so it is resistant to cuts, etc. Damage to the carcass due to cracks can be prevented and the service life of the tire can be greatly extended.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the present invention, and FIG. 2 is a diagram showing another embodiment. 2-bead core, 3 bead section, 4-side wall section, 5-tread section, 7 carcass, 7A main body section, 7B-folding section, 9-belt layer, 10-protective layer, 16--side protection section, 17 −・
Reinforcement ply, 1- Baseline. R-rim, FH-flange height.

Claims (1)

[Claims] 1. A carcass with a bias structure consisting of multiple plies, which is provided with a folded part that is folded from the inside of the tire to the outside around the bead core of the bead part at both ends of the main body part extending from the tread part to the sidewall part to the bead part. , a belt layer disposed outside the carcass and inside the tread portion, the belt comprising a reinforcing ply in which protective cords are arranged at an angle of 30 degrees or more and 90 degrees or less with respect to the tire circumferential direction; A protective layer is provided that extends radially inward on the outside of the carcass from near the outer end of the layer in the tire axial direction through the buttress portion and along the sidewall portion, while a radius from the baseline of the bead portion inside the protective layer is provided. The inner end height H of the protective layer, which is the length in the direction, is measured from the position 0.7 times the tire cross-sectional height h to the standard rim flange height (FH
) pneumatic tires.