JP4410901B2 - Processing method and processing apparatus for tire carcass ply material - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a processing method and processing apparatus for a material for a carcass ply of a tire, and more particularly, to an unvulcanized bead core member having a cross section of a polygonal shape to a round shape before molding of an unvulcanized tire for a pneumatic radial tire. The present invention relates to a processing method and a processing apparatus for plastically deforming a steel cord of a material for a carcass ply to be rolled back along a corner or a round cross section corresponding to a polygonal vertex of a bead core.
[0002]
[Prior art]
Among pneumatic radial tires, a so-called heavy duty pneumatic radial tire used for heavy vehicles such as trucks and buses generally uses a rubber-coated ply of a steel cord for a carcass. In addition, since this type of tire is filled with a high internal pressure, a structure is employed in which the carcass is folded around the bead core from the inside of the tire to the outside and the carcass is locked to the pair of bead cores.
[0003]
However, since the carcass folding is located in the radial direction in the rubber of the bead part and has a cut-off end, a large strain concentrates on the carcass folding end under the rolling load of the tire, and the carcass folding takes place. A separation failure tends to occur from the end. Therefore, in order to avoid strain concentration at the folded end, a winding in which the end 31E of the carcass 31 wraps around the circumferential surface of the bead core 32, instead of the folded structure up to that point, as shown in FIG. Including structures have been proposed.
[0004]
However, the winding end portion 31E remains in the winding deformation within the elastic region of a large number of steel cords embedded in the ply of the carcass 31, and the steel cord of the carcass 31 is in a radial arrangement and has a rebound resilience. Since the force is large, the bead core 32 is moved away from the tire during the manufacturing process. As a result, it becomes difficult to realize a desired bead core winding state, eventually, concentrated strain acts on the winding end 31Ee in the rubber, and a failure from crack generation to burst is likely to occur, as expected. The bead portion durability cannot be improved.
[0005]
Therefore, the present applicant has already proposed a pneumatic tire in which one or more plastic deformation portions are provided in the bead core winding portion of the carcass ply in the specification related to Japanese Patent Application No. 11-19847. The specification related to No. -28762 proposes a method of manufacturing a pneumatic tire that plastically deforms (kneads) an unvulcanized carcass ply material. The bead core entrainment portion that undergoes plastic deformation is shown in the cross-sectional view of the bead portion of FIG. In the bead portion 20 shown in FIG. 9, the carcass 21 has a winding portion 21R of a bead core 22, and the bead core 22 has a substantially hexagonal cross section, and the winding portion 21R has plastic deformation points p ₁ , p ₂ , p. _{Has 3} .
[0006]
By providing plastic deformation points p ₁ , p ₂ , and p ₃ in the winding portion 21R, the winding portion 21R is located along the peripheral surface of the bead core 22, so that the strain acting on the winding end 21Re is significantly reduced. It has been confirmed that the separation resistance of the winding end 21Re is greatly improved, and the durability of the bead portion 20 is significantly improved. When the winding end 21Re is positioned closer to the bead core 22, the plastic deformation portion near the winding end 21Re plays a particularly important role.
[0007]
[Problems to be solved by the invention]
The remaining problem is to reliably perform the plastic deformation of the winding portion 21R of the bead core 22, that is, the plastic deformation of the steel cord, and to perform this plastic deformation work with higher productivity.
[0008]
Therefore, the object of the invention described in claims 1 to 12 of the present invention is to completely solve the above-mentioned remaining problems, and more specifically, it is a long length that is cut into a predetermined width and jointed before the molding process. Method for processing a material for carcass ply of a tire capable of causing plastic deformation with high productivity and high productivity in an unvulcanized rubber coated radial array steel cord fabric, and processing for realizing the processing method To provide an apparatus.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the invention described in claim 1 of the present invention is directed to either one of a direction orthogonal to the arrangement direction and an oblique direction of a plurality of parallel arrangement steel cords coated with unvulcanized rubber. Pushing of the extending carcass ply material with two or more refracting corners at the tip at at least one position in the cord arrangement direction at each side portion that wraps around the bead core disposed in the bead portion of the tire By using the blade, the carcass ply material is pressed into a groove having a refraction angle portion corresponding to each refraction angle portion of the pushing blade, thereby forming a winding portion that is plastically deformed and refracted in a direction to be wound around the bead core. This is a method for processing a material for a carcass ply of a tire.
[0010]
In order to realize the invention described in claim 1, the invention described in claim 2 of the present invention includes a table for supporting a carcass ply material in which a large number of parallel array steel cords are coated with unvulcanized rubber. And a pressing blade that can be pressed in a direction perpendicular to the support base, and the support base has a groove extending in one of a direction orthogonal to the steel cord arrangement direction and an oblique direction of the material to be supported. The groove has two or more refracted corners on the groove bottom side, including the corners connecting the both wall surfaces and the bottom of the groove, and the pushing blade has a tip located directly above the groove of the support base. And the tip has a shape having a refraction angle portion corresponding to the refraction angle portion of the groove along the groove shape of the support base through the material at the time of pressing, and by pressing operation of the pushing blade , tip presses on the groove wall surface and the groove bottom surface of the support base of the material, pressing圧素material portion Steel cord to a processing device of the material for the carcass ply only tire characterized by having a function of plastic deformation between the corresponding refraction angle section cross.
[0011]
Regarding the invention described in claim 2, as in the invention described in claim 3, the pushing blade has vertical moving means perpendicular to the support base, and the means has a mechanism that enables the pushing blade to be pressed. .
[0012]
As for the invention described in claims 2 and 3, as in the invention described in claim 4, the pressing blade has a rotatable ring shape, and at least the supporting table of the supporting table and the pressing blade has a groove extending. Separately from this, as in the invention described in claim 5, the pushing blade has a long shape whose longitudinal direction is the direction in which the groove of the support base extends, and the shape The front end portion of the pressing blade having a straight portion includes a straight front end surface extending in parallel with the groove of the support base.
[0013]
Further, regarding the invention described in claim 2, as in the invention described in claim 6, the pushing blade has a long shape whose longitudinal direction is the direction in which the groove of the support base extends, and the tip portion is in the longitudinal direction. The pushing blade having a straight tip surface and having these shapes has a turning means for the support base with the one end in the longitudinal direction as the turning center, and the turning means performs the pressing operation of the pushing blade. It has a mechanism that enables it.
[0014]
In addition to the invention described in claim 6, regarding the invention described in claim 2, as in the invention described in claim 7, the pushing blade has a length in which the direction in which the groove of the support base extends is the longitudinal direction. This long shaped pusher blade has a downwardly convex longitudinal curved surface at the tip end face, and the pusher blade presses and swings the tip end curved face toward the groove bottom of the support base. Have means.
[0015]
With respect to the inventions described in claims 2 and 3 and claims 5 to 7, as in the invention described in claim 8, the support base has means for moving in the direction in which the groove of the support base extends.
[0016]
Regarding the invention described in claims 2 to 8, as a representative embodiment, as in the invention described in claim 9, the surface of the support base has a planar shape, the support base includes a pair of grooves, The groove bottom surface and both wall surfaces, which have a U-shaped cross-sectional shape, extend from the end of the connecting corner between the groove wall surfaces and the groove bottom surface, have a planar shape, and the groove bottom surface has a plane parallel to the support table surface.
[0017]
Moreover, regarding the invention described in claims 2 to 9, as in the invention described in claim 10, the groove of the support table has a depth H _{1 of} 0.1 mm or more and 0 to the normal of the support table surface. Both wall surfaces having an inclination angle θ ₁ in a range of ˜80 ° and a connecting corner chamfer radius R ₁ in a range of 0-15 mm.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to FIGS.
1 and 2 are cross-sectional views of a main part of a processing apparatus for a carcass ply material for a tire according to the present invention,
3 and 4 are cross-sectional views of main parts of the carcass ply material after plastic deformation by the processing apparatus shown in FIGS.
5 to 8 are side views schematically illustrating the pushing blade of the present invention.
[0021]
1 and 2, the processing apparatus includes a base 5 for supporting a material (hereinafter referred to as a raw material) 3 for a carcass ply 21 in which a large number of parallel-arranged steel cords 1 are coated with unvulcanized rubber 2, and the support base 5 And a pressing blade 6 that can be pressed in the vertical direction (the direction of arrow A). In addition, the structural member of a pneumatic tire shall use the code | symbol shown in FIG. 9 (hereinafter the same).
[0022]
The support base 5 includes a groove 7 extending in a direction orthogonal to or oblique to the steel cord 1 arrangement direction of the material 3 to be supported. The material 3 is a material in a process prior to the molding process. Preferably, the material 3 is unwound again from a large roll obtained by winding a fabric in which the unvulcanized rubber 2 is coated on the long steel cord 1, and this is unrolled. It is a long object with small pieces cut into widths.
[0023]
As described above, since the long material 3 is a material after various treatments are performed, it is generally called a long treat. The long material 3 is trimmed to a predetermined length and used as a member for molding an unvulcanized tire for a pneumatic radial tire. Therefore, the steel cord 1 is either an array orthogonal to the longitudinal direction or a slightly oblique array. It is.
[0024]
As shown in FIGS. 1 and 2, the groove 7 of the support base 5 has two or more refracting angle portions P ₁ , P ₂ , P ₃ ,..., P _n on the groove bottom surface 7B side. However, these refracting corners include connecting corners P ₁ and P ₂ between both wall surfaces 7W of the groove 7 and the groove bottom surface 7B. FIG. 1 shows an example of _two refraction angle portions P ₁ and P ₂ , and FIG. 2 shows an example of three refraction angle portions P ₁ , P ₂ , and P ₃ . The number of refraction corners is preferably determined by the number of vertices of the cross-sectional shape of the bead core 22. When the bead core is circular or oval, the number of refraction angle portions is increased as much as possible.
[0025]
The pushing blade 6 has a tip 6-1 located immediately above the groove 7 of the support base 5. The tip 6-1 has a shape that follows the shape of the groove 7 of the support base 5 through the material 3 when the long material 3 supported by the pressing blade 6 on the support base 5 is pressed into the groove 7. Of this shape, in particular, the refraction angle of the grooves _{7 P 1, P 2, P} 3, ···, the tip portion 6-1 surface position corresponding to P _n, same refraction angle section Q _1, Q ₂ , Q ₃ ,..., Q _n is important.
[0026]
1 and 2 show a pressing operation state of the pushing blade 6 into the groove 7 with respect to the material 3. By this operation, the tip portion 6-1 of the pushing blade 6 presses a part of the material 3 against the groove wall surface 7W and the groove bottom surface 7B of the support base 5, and each of the pressed steel cords 1 of the material 3 is respectively pressed. .., P _n and the refraction angle portions Q ₁ , Q ₂ , Q ₃ ,..., Q _n of the tip portion 6-1 and the corresponding refraction angle portions P ₁ , P ₂ , P ₃ ,. Plastic deformation between them.
[0027]
FIG. 3 shows a cross section of the material 3 plastically deformed by the processing apparatus shown in FIG. 1, and FIG. 4 shows a cross section of the material 3 plastically deformed by the processing apparatus shown in FIG. In FIGS. 3 and 4, broken circles are places where plastic deformation has occurred. In each figure, the plastic deformation portion p ₁ corresponds to the refraction angle portions P ₁ and Q ₁ , the plastic deformation portion p ₂ corresponds to the refraction angle portions P ₂ and Q ₂ , and the plastic deformation portion p ₃ corresponds to the refraction angle portion P 1. _3, corresponding to the Q _3.
[0028]
The processing apparatus described above realizes the processing method of the carcass ply material 3 described below.
That is, referring to FIG. 9, the bead portion of the tire of the material 3 for the carcass ply 21 extending in the direction orthogonal to or oblique to the arrangement direction of the multiple parallel arrangement steel cords 1 coated with the unvulcanized rubber 2. In each side portion (a portion corresponding to the winding portion 21R) that is wound around the bead core 21 disposed in 20, at least one place in the arrangement direction of the steel cord 1, usually two pairs, the following part p ₁ in a direction to return the bead core 21 wound by the _{method, p 2, p 3, ···} , to form a winding portion for refracting plastically deformed by p _n.
[0029]
It refraction angle portion to Q ₁ or 2 places the tip 6-1, Q _2, Q _3, · · ·, the push blade 6 with Q _n, the carcass ply material for 3, each refraction of pushing blades 6 corners _{Q 1, Q 2, Q 3} , ···, refraction corner P ₁ of each Q _n corresponding, P _2, P _3, by pressing., in the groove 7 with P _n. The purpose of this processing method is to form plastic deformation portions p ₁ , p ₂ , p ₃ ,..., _Pn , and thus the processing apparatus described above is an example for realizing the processing method. .
[0030]
Since the plastically deformed portions p ₁ , p ₂ , p ₃ ,..., _Pn of the material 3 can be processed under a sufficient pressing force exceeding the elastic limit of the steel cord 1, Deformation can be maintained throughout the product tire. Moreover, when applying each plastic deformation part to the corner | angular part of the member used as the bead core 22 (refer FIG. 9) in a shaping | molding process, and sticking another required member to this and making it an unvulcanized tire, beforehand, Since the raw material 3 has a plastic deformation part, the molding efficiency can be maintained at a high level.
[0031]
The unvulcanized tire is vulcanized to obtain a product tire, and a bead portion 20 shown in FIG. 9 is obtained. In the product tire, the material 3 is a carcass 21 and the crease portions p ₁ , p ₂ , and p ₃ of the winding portion 21R are plastic deformation portions p ₁ , p ₂ , and p ₃ . Therefore, the winding portion 21R includes the winding end 21Re along the peripheral surface of the bead core 22, and hardly receives any distortion on the winding end 21Re in the actual use state. Remarkably improved.
[0032]
In practice, this processing apparatus has vertical moving means (not shown) in which the pressing blade 6 is perpendicular to the support base 5. Accordingly, as shown by arrows A and B at both ends in FIGS. 1 and 2, the pushing blade 6 is moved upward (in the direction of arrow B) when not in operation, and the pushing blade 6 is moved down (in the direction of arrow A) during operation. ) To cause a pressing operation.
[0033]
Moreover, as shown in FIG. 5, it is set as the ring shape which supports the pressing blade 6 with the axis | shaft 10, and the ring-shaped pressing blade 6 is made rotatable in the arrow direction of FIG. At this time, at least the support base 5 of the support base 5 and the pushing blade 6 includes means for moving in the direction in which the groove 7 extends. When the support base 5 includes moving means, the ring-shaped pressing blade 6 is freely rotated. For example, when the support base 5 moves in the direction of the arrow in FIG. 5, the pressed ring-shaped pressing blade 6 rotates. If it does in this way, the plastic deformation process with respect to the elongate raw material 3 can be performed continuously.
[0034]
Moreover, instead of the ring-shaped pressing blade 6, as shown in FIG. 6, the pressing blade 6 has a long shape in which the direction in which the groove 7 of the support base 5 extends is the longitudinal direction. The pushing blade 6 tip 6-1 having a long shape includes a straight tip surface extending in parallel with the groove 7 of the support 5.
[0035]
Moreover, it has the long shape which makes the direction where the groove | channel 7 of the support stand 5 extends in a longitudinal direction, and a front-end | tip part is the same as said elongate pushing blade 6 in the point provided with a straight front end surface in a longitudinal direction. However, the pushing blade 6 shown in FIG. 7 has a longitudinal center at one end 11 as a center of rotation, and rotates around the center of rotation 11 in the directions of arrows A ₁ and B _{1 with} respect to the support base 5 (illustrated). (Omitted). The rotating means has a mechanism that enables the pressing blade 6 to be pressed.
[0036]
Further, the pushing blade is the same as the pushing blade 6 shown in FIGS. 6 and 7 in that it has a long shape whose longitudinal direction is the direction in which the groove of the support base extends, but the long pushing shown in FIG. The blade 6 is different in that it has a downwardly convex longitudinal curved surface on the end surface. The push blade 6 performs oscillating motion as indicated by double-headed arrow toward the tip end curved bottom surface 7B of the groove 7 of the support 5, and has means (not shown) for pressing the arrow A ₂ direction .
[0037]
In the processing apparatus provided with the long pushing blade 6 described above, the support base 5 has means for moving in the direction in which the groove 7 extends. If it does in this way, the plastic deformation process with respect to the elongate raw material 3 can be performed continuously.
[0038]
Here, the processing apparatus shown in FIG. 1 is a representative example, and a more specific description will be added to this apparatus. That is, the surface of the support base 5 has a planar shape. The support base 5 includes a pair of grooves 7, and the grooves 7 have a U-shaped cross-sectional shape. The connecting corners P ₁ and P ₂ between the both wall surfaces 7W and the groove bottom surface 7B of the groove 7 have a planar shape. The groove bottom surface 7B has a plane parallel to the surface of the support base 5.
[0039]
The groove 7 of the support base 5 has the following specifications. That is, the depth H ₁ is 0.1 mm or more, and the inclination angle θ ₁ of both wall surfaces 7W with respect to the normal of the surface of the support base 5 is in the range of 0 to 80 °, preferably in the range of 20 to 70 °. The chamfer radius R ₁ of the connecting (refractive) corners P ₁ and P ₂ has a value in the range of 0 to 15 mm, preferably in the range of 0 to 12 mm.
[0040]
On the other hand, the tip 6-1 of the pushing blade 6 has the following specifications. That is, the inclination angle θ ₂ of both inclined planes from the tip plane is in the range of 0 to 80 °, preferably in the range of 20 to 70 °, and the height H ₂ from the tip plane to the upper end of both inclined planes is 0. 1 mm or more, the tip plane width D ₁ is 2 mm or more, the width D ₂ at the height H ₂ position is 2 mm or more, and the chamfer radii of the refraction angle portions Q ₁ and Q ₂ of the tip 6-1 R ₂ has a value in the range of 0-10 mm, preferably in the range of 0-8 mm.
[0041]
The processing apparatus shown in FIG. 1 has an inclination angle θ ₁ ≧ inclination angle θ ₂ and a groove depth H ₁ ≦ height H between the groove 7 of the support base 5 and the tip 6-1 of the pressing blade 6. _{2. It} is assumed that the relationship of chamfer radius R ₁ ≧ chamfer radius R ₂ is satisfied. Accordingly, the best plastic deformation portions p ₁ and p ₂ can be efficiently formed on the material 3.
[0042]
It is also possible to omit the unvulcanized coated rubber 2 and directly plastically deform the array of steel cords 1. However, in this case, since the steel cord 1 is free with respect to the surface of the tip portion 6-1 of the pushing blade 6, it has a tendency to escape from the surface of the tip portion 6-1 and therefore is difficult to be plastically deformed.
[0043]
In this sense, even if the unvulcanized coated rubber 2 is used, if it is a thin gauge, the steel cord 1 may appear in the same manner as described above when pressed, so that the material 3 is subject to the plastic deformation target portion. A rubber sheet having a gauge of about 0.3 to 1.5 mm is preferably bonded in advance. In the case of only the steel cord 1 or when the steel cord 1 is exposed, a rubber sheet may be bonded to the bead core winding portion at the time of molding the unvulcanized tire.
[0044]
【The invention's effect】
According to the invention described in claims 1 to 12, the long unvulcanized rubber-coated radial array steel cord cut into a predetermined width and joined before the molding step is effective and highly efficient in plastic deformation. And a method for processing a material for carcass ply of a tire capable of maintaining high productivity in the molding process and ensuring a significant improvement in bead durability in a product tire, and A processing apparatus that realizes the processing method can be provided.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an essential part of a processing apparatus for a material for a carcass ply of a tire according to the present invention.
FIG. 2 is a cross-sectional view of a main part of another processing apparatus for a material for a carcass ply of a tire according to the present invention.
FIG. 3 is a cross-sectional view of a main part of the carcass ply material after plastic deformation by the processing apparatus shown in FIG.
4 is a cross-sectional view of the main part of the carcass ply material after plastic deformation by the processing apparatus shown in FIG. 2;
FIG. 5 is a side view of a simplified illustration of a ring-shaped pushing blade according to the present invention.
FIG. 6 is a side view of a simplified illustration of a long shaped pushing blade of the present invention.
FIG. 7 is a side view of a simplified illustration of another elongate pushing blade of the present invention.
FIG. 8 is a side view of a simplified illustration of still another elongated pushing blade according to the present invention.
FIG. 9 is a cross-sectional view of a bead portion of a tire using the material of the present invention.
FIG. 10 is a cross-sectional view of a bead portion of a conventional tire.
[Explanation of symbols]
1 Steel cord 2 Cover rubber 3 Material 5 Support base 6 Push blade 6-1 Tip 7 Groove 7W Groove wall surface 7b Groove bottom surface P ₁ , P ₂ , P ₃ groove refraction angle part Q ₁ , Q ₂ , Q ₃ tip Refraction angle part p ₁ , p ₂ , p ₃ material refraction angle part

Claims (10)

 Around the bead core disposed in the bead portion of the tire of the carcass ply material extending in one of the orthogonal direction and the oblique direction with respect to the arrangement direction of the multiple parallel arrangement steel cords coated with unvulcanized rubber At each side part to be rolled back, the carcass ply material corresponds to each refraction angle part of the push blade by pushing blades having at least one refraction angle part at the tip part in at least one place in the cord arrangement direction. A method for processing a carcass ply material for a tire, comprising forming a winding portion that is plastically deformed and refracted in a direction to be wound around a bead core by being pressed into a groove having a bending angle portion. It has a base for supporting a carcass ply material in which a large number of parallel-arranged steel cords are coated with unvulcanized rubber, and a pressing blade that can be pressed in a direction perpendicular to the support base. A groove extending in one of a direction orthogonal to the steel cord arrangement direction and an oblique direction of the material is provided, and the groove includes two or more refraction angles including a connecting corner portion between both wall surfaces of the groove and the groove bottom surface. Part on the groove bottom side, the pushing blade has a tip portion located directly above the groove of the support base, the tip portion follows the groove shape of the support base through the material at the time of pressing, and It has a shape having a refracting angle portion corresponding to the refracting angle portion of the groove, and the pressing portion of the pressing blade presses the material against the groove wall surface and the groove bottom surface of the support base, and the pressing material portion The steel cord has the function of plastically deforming between the corresponding refracting corners. To, material processing equipment for the carcass plies of the tire.  The processing apparatus according to claim 2, wherein the pressing blade has vertical movement means perpendicular to the support base, and the means has a mechanism that enables the pressing blade to be pressed.  The processing apparatus according to claim 2 or 3, wherein the pressing blade has a rotatable ring shape, and at least the support base among the support base and the pressing blade has means for moving in a direction in which the groove extends.  The pressing blade has a long shape whose longitudinal direction is a direction in which the groove of the support base extends, and the front end portion of the pressing blade having the shape includes a straight tip surface extending in parallel with the groove of the support base. Or the processing apparatus described in 3.  The pushing blade has a long shape whose longitudinal direction is the direction in which the groove of the support base extends, and the tip portion has a straight tip surface in the longitudinal direction, and the pushing blade having these shapes has one end in the longitudinal direction. The processing apparatus according to claim 2, further comprising: a pivoting means with respect to the support base, the pivoting means having a mechanism that enables a pressing operation of the pressing blade.  The pressing blade has a long shape whose longitudinal direction is the direction in which the groove of the support base extends, and this long pressing blade has a downwardly convex longitudinal curved surface on the end surface, and the pressing blade is The processing apparatus according to claim 2, further comprising means for pressing and swinging the end curved surface of the tip toward the groove bottom of the support base.  The processing device according to any one of claims 2 and 3 and claims 5 to 7, wherein the support table has means for moving in a direction in which the groove of the support table extends.  The surface of the support base has a planar shape, the support base includes a pair of grooves, the grooves have a U-shaped cross-sectional shape, and the groove bottom surface and both wall surfaces extending from the end of the connecting corner between the groove wall surfaces and the groove bottom surface 9 has a planar shape, and the groove bottom surface has a plane parallel to the support table surface.  The groove of the support table has a depth (H1) of 0.1 mm or more, both wall surfaces having an inclination angle (θ1) within a range of 0 to 80 ° with respect to the normal of the support table surface, and a range of 0 to 15 mm. The processing apparatus according to any one of claims 2 to 9, which has a chamfering radius (R1) inside the connecting corner.

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