EP1001074A2 - Câbles d'acier pour le renforcement des articles en caoutchouc et pneumatiques - Google Patents
Câbles d'acier pour le renforcement des articles en caoutchouc et pneumatiques Download PDFInfo
- Publication number
- EP1001074A2 EP1001074A2 EP99308899A EP99308899A EP1001074A2 EP 1001074 A2 EP1001074 A2 EP 1001074A2 EP 99308899 A EP99308899 A EP 99308899A EP 99308899 A EP99308899 A EP 99308899A EP 1001074 A2 EP1001074 A2 EP 1001074A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- cord
- twisting
- sheath
- steel
- strand
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B1/00—Constructional features of ropes or cables
- D07B1/06—Ropes or cables built-up from metal wires, e.g. of section wires around a hemp core
- D07B1/0606—Reinforcing cords for rubber or plastic articles
- D07B1/0613—Reinforcing cords for rubber or plastic articles the reinforcing cords being characterised by the rope configuration
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B2201/00—Ropes or cables
- D07B2201/10—Rope or cable structures
- D07B2201/1028—Rope or cable structures characterised by the number of strands
- D07B2201/1032—Rope or cable structures characterised by the number of strands three to eight strands respectively forming a single layer
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B2201/00—Ropes or cables
- D07B2201/10—Rope or cable structures
- D07B2201/104—Rope or cable structures twisted
- D07B2201/1044—Rope or cable structures twisted characterised by a value or range of the pitch parameter given
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B2201/00—Ropes or cables
- D07B2201/10—Rope or cable structures
- D07B2201/104—Rope or cable structures twisted
- D07B2201/1052—Rope or cable structures twisted using lang lay, i.e. the wires or filaments being inclined relative to the rope axis
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B2201/00—Ropes or cables
- D07B2201/10—Rope or cable structures
- D07B2201/104—Rope or cable structures twisted
- D07B2201/1064—Rope or cable structures twisted characterised by lay direction of the strand compared to the lay direction of the wires in the strand
- D07B2201/1068—Rope or cable structures twisted characterised by lay direction of the strand compared to the lay direction of the wires in the strand having the same lay direction
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B2201/00—Ropes or cables
- D07B2201/20—Rope or cable components
- D07B2201/2001—Wires or filaments
- D07B2201/2006—Wires or filaments characterised by a value or range of the dimension given
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B2201/00—Ropes or cables
- D07B2201/20—Rope or cable components
- D07B2201/2015—Strands
- D07B2201/2023—Strands with core
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B2201/00—Ropes or cables
- D07B2201/20—Rope or cable components
- D07B2201/2015—Strands
- D07B2201/2024—Strands twisted
- D07B2201/2025—Strands twisted characterised by a value or range of the pitch parameter given
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B2201/00—Ropes or cables
- D07B2201/20—Rope or cable components
- D07B2201/2015—Strands
- D07B2201/2038—Strands characterised by the number of wires or filaments
- D07B2201/2039—Strands characterised by the number of wires or filaments three to eight wires or filaments respectively forming a single layer
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B2201/00—Ropes or cables
- D07B2201/20—Rope or cable components
- D07B2201/2047—Cores
- D07B2201/2051—Cores characterised by a value or range of the dimension given
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B2201/00—Ropes or cables
- D07B2201/20—Rope or cable components
- D07B2201/2047—Cores
- D07B2201/2052—Cores characterised by their structure
- D07B2201/2059—Cores characterised by their structure comprising wires
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B2501/00—Application field
- D07B2501/20—Application field related to ropes or cables
- D07B2501/2046—Tire cords
Definitions
- This invention relates to a steel cord used as a reinforcing member for rubber articles such as pneumatic tires, industrial belts and the like, and more particularly to steel cords having an excellent durability.
- Pneumatic tires as a typical example of the rubber articles are mounted onto a large-size dump truck or the like used on, for example, large-scale civil engineering site or ore working site and subjected to severer service conditions on wasteland surface under heavy loading.
- this type of the tire has a structure that a carcass is toroidally extended between a pair of bead cores as a casing skeleton and a belt of plural layers is disposed on an outside of the carcass in a radial direction of the tire.
- an object of the invention to provide steel cords capable of developing a sufficient durability even in the use under the severe condition subjected to repetitive compression deformation as well as a pneumatic tire having an excellent durability.
- the steel cord constituting the belt layer adopts so-called strand construction formed by twisting plural strands each being formed by twisting plural steel filaments.
- steel cords of the strand construction having 1 x n structure wherein the cord is formed by twisting n-strands of a layer construction formed by twisting plural steel filaments around a core of one or more steel filaments, are preferably used in the outermost belt layer constituting the belt of the tire for construction vehicle in order that the outermost belt layer is followed to the tread deformation when the tread rides on the projection during the running of the tire.
- the breakage of the cord having the strand construction results from the fact that the large compression strain is caused in the sheath filament constituting the strand to precedentially break the sheath filament.
- the inventors have made various studies with respect to means for controlling the large compression strain produced in the sheath filament and found that it is very effective to adequately define a twisting angle of the sheath filament for improving the fatigue resistance of the cord.
- the outermost belt layer of the belt is apt to cause corrosion due to incorporation of water passed through cut damage or the like in the tire into the inside of the cord constituting the belt layer, it is important to arrange the filaments of the cord so as to surely penetrate rubber into a gap between the filaments.
- twisting angle a is represented by an average in a longitudinal direction of the cord.
- the invention lies in a pneumatic tire comprising a carcass toroidally extended between a pair of bead cores as a casing skeleton and a belt of plural layers disposed on an outside of the carcass in a radial direction of the tire, wherein the above defined steel cords are applied to at least an outermost belt layer in the belt.
- the number of strands m is 4 to 5 and the number of filaments n in the sheath is 4 to 5.
- the number of strands m is 3 or less, if the cord is used as a cord in an outermost belt layer constituting a belt for a large-size tire such as construction vehicle tire or the like, it is necessary to make the diameter of the filament in order to obtain a given tire strength, and as the filament diameter becomes thick, strain on the surface of the filament becomes large due to local bending between the filaments when the cord is subjected to bending deformation by riding on the projection, and hence it is easy to cause the cord breaking.
- the number of strands m is 6 or more, it is difficult to arrange the strands on a concentric circle and the twisting property is degraded to make a breaking load of the cord small.
- the reason why the core in the strand is made of a single filament is due to the fact that the number of filaments in the core is naturally 1 or 2 in order to penetrate rubber into the inside of the cord, but when two filaments are used in the core, poor twisting is apt to be caused due to the difference of twisting shrink amount between the core and the sheath in the step of producing the cord by twisting the strands.
- the diameters of the core filament and sheath filament are within the ranges defined in the invention as mentioned below, if the number of filaments n for the sheath is 3 or less, the gap between the filaments in the sheath is too large and the twisting shape become unstable, while when it is 6 or more, the gap enough to penetrate rubber can not be ensured.
- FIG. 1 A typical example of the cord having a basic structure of m x (1 + n) according to the invention is sectionally shown in Fig. 1.
- This cord has a twisting construction of 5 x (1 + 4) formed by twisting five strands 1 of 1+4 structure.
- Each strand 1 is formed by twisting four steel filaments arranged adjacent to each other as a sheath 3 around a core 2 made of a single steel filament.
- the twisting direction of m strands or the twisting direction of the cord is the same as the twisting direction of sheath filaments in the strand or the twisting direction of the strand. Because, when the twisting direction of the cord is different from the twisting direction of the strand, the filaments between the strands contact at a point and hence the twisting loss or the lowering ratio of the breaking load of the cord when a sum of breaking loads of the filaments is 100% becomes large, and as a result, even when the breaking load of the cord is made large, it can not be developed.
- the ratio d S /d C of diameter of the filament d S constituting the sheath to diameter of the filament d C constituting the core is within a range of 1.00-1.75, preferably 1.5-1.75.
- the ratio d S /d C is less than 1.00, the core is protruded from the strand due to the difference of the twisting shrink amount between the core and the sheath in the step of producing the cord by twisting the strands, while when the ratio d S /d C exceeds 1.75, the arrangement of the sheath filaments is eccentric and the twisting property in the cord becomes ununiform.
- the twisting angle a of the sheath in each strand with respect to the axis of the cord as calculated by the equation (1) is within a range of 30-52°, preferably 35-45°.
- the twisting angle a is less than 30°, the twisting pitch should be made considerably short, and hence the filament is unavoidably subjected to strong work in the production step of the cord and troubles such as breakage and the like are apt to be caused, while when the twisting angle a exceeds 52°, the fatigue life of the cord becomes shorter than that of steel cord of 4 ⁇ (1 + 5 ⁇ 0.25) frequently used in an outermost layer of the belt in the tire for construction vehicle and hence there is a risk of causing tire breakage in a short time.
- the cords according to the invention are used for the reinforcement of the carcass by arranging a plurality of the cords side by side and embedding in a rubber sheet to form a rubberized belt layer for a belt of the tire.
- the structure of the tire it is sufficient to have the same as in the conventional pneumatic tire for the construction vehicle.
- the belt structure shown in Fig. 2 is advantageously adaptable. In Fig.
- numeral 4 is a carcass toroidally extending between a pair of bead cores (not shown) and turned around the bead core from an inside of the tire toward the outside thereof, numeral 5 a belt disposed on the carcass 4 and comprised of 4-6 belt layers, a belt of 6 belt layers in the illustrated embodiment, numeral 6 a tread disposed on the belt, and numeral 7 a lug groove.
- the belt 5 has a structure that 6 belt layers each containing many steel cords arranged at a certain inclination angle, preferably angle of 50-80° with respect to the cord in the carcass 4 are lain one upon the other so as to cross the cords of these layers with each other.
- the cords according to the invention are applied to at least an outermost belt layer of the belt.
- the durability is measured with respect to steel cords having a construction shown in Table 1. That is, a fatigue test of repeatedly causing a given compression strain in a direction of cord axis is carried out with respect to each of these cords to measure the repetitive number of compression strain until the breakage of any one of the filaments constituting the cord. The measured results are also shown in Table 1.
- each of the steel cords shown in Table 1 is used in an outermost belt layer among 6 belt layers constituting a belt of an off-the-road radial tire having a tire size of 40.00R57 at an end count of 13.1 cords/5 cm.
- steel cords of 7 ⁇ (3 + 9 ⁇ 0.32 mm) are used in two middle belt layers among the remaining five belt layers and steel cords of 7 ⁇ (3 + 9 ⁇ 0.23 mm) are used in three inner belt layers.
- Each of the tires is inflated under an inner pressure of 7.0 kgf/cm 2 and actually run on road till the tread is completely worn.
- Example 1 Example 2 Cord construction 4 x (1+5) 4 x (1+4) 5 x (1+4) 5 x (1+4) 5 x (1+4) Filament diameter in core d C (mm) 0.25 0.18 0.21 0.21 0.21 Filament diameter in sheath d S (mm) 0.25 0.285 0.34 0.34 0.34 d S /d C 1.00 1.58 1.62 1.62 1.62 Twisting pitch of strand P 1 (mm) 5.02 4.98 6.83 5.24 5.02 Twisting pitch in cord P 2 (mm) 11.26 8.13 12.20 12.25 11.26 Twisting direction S/S/S Z/Z/Z Z/Z/Z Z/Z/Z Cord diameter A (mm) 1.687 1.702 2.201 2.555 2.658 Twisting angle of shea
- steel cords capable of developing the sufficient durability even in the use under severe condition repeatedly subjected to compression deformation. Therefore, when such steel cords are applied to at least an outermost belt layer in a belt of a tire, the durability against compression strain particularly concentrated in the groove bottom of the tread is considerably improved and hence it is possible to provide a tire having an excellent tire durability.
Landscapes
- Tires In General (AREA)
- Ropes Or Cables (AREA)
- Reinforced Plastic Materials (AREA)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP32330598A JP4097812B2 (ja) | 1998-11-13 | 1998-11-13 | ゴム物品補強用スチールコードおよび空気入りタイヤ |
JP32330598 | 1998-11-13 |
Publications (3)
Publication Number | Publication Date |
---|---|
EP1001074A2 true EP1001074A2 (fr) | 2000-05-17 |
EP1001074A3 EP1001074A3 (fr) | 2000-09-06 |
EP1001074B1 EP1001074B1 (fr) | 2003-04-09 |
Family
ID=18153308
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP99308899A Expired - Lifetime EP1001074B1 (fr) | 1998-11-13 | 1999-11-09 | Câbles d'acier pour le renforcement des articles en caoutchouc et pneumatiques |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP1001074B1 (fr) |
JP (1) | JP4097812B2 (fr) |
ES (1) | ES2196729T3 (fr) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8261795B2 (en) | 2006-06-29 | 2012-09-11 | Bridgestone Corporation | Pneumatic radial tire for heavy load |
CN111511983A (zh) * | 2017-12-19 | 2020-08-07 | 米其林集团总公司 | 具有极低、低和中等的模量的双层多线股帘线 |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7763191B2 (en) | 2005-05-27 | 2010-07-27 | Gentex Optics, Inc. | Method and apparatus for performing an in-mold coining operation |
CN100591507C (zh) * | 2006-12-08 | 2010-02-24 | 鸿富锦精密工业(深圳)有限公司 | 光学元件模具 |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3911662A (en) * | 1973-01-22 | 1975-10-14 | Nat Standard Co | Steel tire cords, method of making same and articles containing same |
JPH09226318A (ja) * | 1996-02-23 | 1997-09-02 | Bridgestone Corp | 悪路走行用空気入りラジアルタイヤ |
-
1998
- 1998-11-13 JP JP32330598A patent/JP4097812B2/ja not_active Expired - Fee Related
-
1999
- 1999-11-09 ES ES99308899T patent/ES2196729T3/es not_active Expired - Lifetime
- 1999-11-09 EP EP99308899A patent/EP1001074B1/fr not_active Expired - Lifetime
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3911662A (en) * | 1973-01-22 | 1975-10-14 | Nat Standard Co | Steel tire cords, method of making same and articles containing same |
JPH09226318A (ja) * | 1996-02-23 | 1997-09-02 | Bridgestone Corp | 悪路走行用空気入りラジアルタイヤ |
Non-Patent Citations (1)
Title |
---|
PATENT ABSTRACTS OF JAPAN vol. 199, no. 801, 30 January 1998 (1998-01-30) & JP 09 226318 A (BRIDGESTONE CORP.), 2 September 1997 (1997-09-02) * |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8261795B2 (en) | 2006-06-29 | 2012-09-11 | Bridgestone Corporation | Pneumatic radial tire for heavy load |
CN111511983A (zh) * | 2017-12-19 | 2020-08-07 | 米其林集团总公司 | 具有极低、低和中等的模量的双层多线股帘线 |
CN111511983B (zh) * | 2017-12-19 | 2022-03-15 | 米其林集团总公司 | 具有极低、低和中等的模量的双层多线股帘线 |
Also Published As
Publication number | Publication date |
---|---|
EP1001074B1 (fr) | 2003-04-09 |
ES2196729T3 (es) | 2003-12-16 |
JP2000154483A (ja) | 2000-06-06 |
JP4097812B2 (ja) | 2008-06-11 |
EP1001074A3 (fr) | 2000-09-06 |
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