JP2007217820A - Method for producing rubber sheet as tire reinforcing material, and tire using rubber sheet produced by the same method for production - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To produce a tire reinforcing rubber sheet without broken sites in a cord embedded therein by a series of continuous steps. <P>SOLUTION: The tire reinforcing rubber sheet without the broken sites in the cord is produced by the series of continuous steps as follows. A twisting processing step 100, a preforming step 200 of bending the cord twisted in the twisting processing step into a zigzag form or a U-shaped form with a prescribed width on one plane and forming a planar cord body and a rubber sheet producing step 300 of nipping the cord body with an upper and a lower sheet-like rubber bodies and composing the rubber sheet are continuously arranged. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a rubber sheet sandwiching a steel cord used as a tire reinforcing material, and a tire using a rubber sheet manufactured by the manufacturing method.

  Generally, for radial tires, several hundreds of long (several hundreds to tens of thousands of meters) steel cords are arranged in parallel and arranged at intervals based on the specifications of the tires to be used while being drawn out at the same time. A long (several hundreds of thousands to tens of thousands of meters) calendar sheet is formed by calendering, in which the rubber sheet is thinner than both sides in a sandwich state, and the calendar sheet thus constructed is used as a tire. A strip is formed by cutting with a width and a bias angle to be bonded to each other, and these are bonded together to form a tire prototype, which is then placed in a mold and vulcanized at high temperature and high pressure.

In the conventional system, it has been considered that the one-time use amount of the steel cord to be used, that is, the larger the spool winding amount, the longer the calendering operation time and the higher the efficiency.
Also in the processing of steel cords, the process of final twisting has been devised so that the longer the product length, the better the processing efficiency and the longer product can be produced. That is, the rotating part of the twisting machine has inevitably been enlarged in the direction of increasing the spool capacity of the material and increasing the product spool.

Currently, there are two types of stranded wire machines: a tubular type that is twisted once by one rotation in a cylindrical rotation, and a buncher type that is twisted twice by one rotation.
All the stranding machines have an effective energy consumption rate of 10% or less, which is extremely wasteful. This is considered to be due to the mechanical loss for rotating the heavy object at high speed and the loss due to the air resistance of the high-speed rotating body.

In recent years, with the maturity of automobiles, the tires for automobiles have also matured. As a result, the required quality of tires has also diversified, and the types of tires have been increased to satisfy functionally diversified requirements.
In order to meet these requirements with the conventional standard mass production method, it is impossible in terms of cost and the like, and it has become necessary to use a new production method that can be processed in a space-saving manner.

In the tire production system, the new production system is in a stage of trial operation in line with the above-mentioned purpose, but it is desired to provide a production form of a steel cord to be used therefor.
Further, there is a demand for the development of a new steel cord processing technology aimed at minimizing resources and minimizing energy without continuing the extremely energy-efficient method described earlier in the era of environmental improvement.

  Furthermore, the calendar sheet manufactured by the conventional manufacturing method is composed of a steel cord made of a plated wire (steel wire). When the calendar sheet is cut into a predetermined length, its cut end Then, the iron core of the wire is exposed. Since the cut end portion is not plated, there arises a problem that adhesion to rubber is not achieved.

The tire is subjected to distortion due to the weight of the vehicle while the vehicle is running, and the maximum load is applied to the shoulder portion of the tire and the turn-up end portion of the ply layer during cornering. The structure is located.
Moreover, in recent years, the flattening of tires has progressed and the width of tires has increased, but as the tire width increases, the distortion of the shoulder portion increases, and the presence of the unbonded portion has become a further problem. .

  The steel cord is embedded in the tire as a reinforcing material that suppresses deformation of the tire during driving, but since the steel cord is cut, the rigidity effect of possessing the reinforcing material is not fully exhibited, and the cornering of the tire In addition to reducing the force, the tread wear due to deformation also caused a decrease in tire life.

  The present invention is intended to address the above-mentioned demands and problems. By developing a new production method for steel cords, it is not necessary to use wasted energy for stranded wire processing of steel cords. Let's provide tire construction rubber sheets and tires manufactured using such rubber sheets, which can be cut without waste, and can reduce the number of tire production methods to eliminate wasteful space and wasteful transportation It is what.

  The present invention relates to a method for producing a rubber sheet as a tire reinforcing material, in which a plurality of strands or a plurality of strands and a strand cord or a plurality of strand cords are drawn out and used as a pair of chucks and a pair of chucks. Gripping with a third chuck disposed substantially at the center and rotating the third chuck to twist the plurality of strands or strands and strands or strand cords After forming the steel cord, the residual stress of the twist is removed, and then the stranded wire is drawn out between the pair of chucks, and the twist direction alternately exists in the S direction and the Z direction by repeating this. The steel cord to be made and the place (non-twisted portion) gripped by the chuck of the steel cord created in this way, on one plane, for example Forming a planar code body by bending Guzagu shape or U-shape, characterized in that to produce a rubber sheet for a tire configuration through the rubber sheet manufacturing process by sandwiching the code body rubber sheet member from above and below.

  Further, in the steel cord manufacturing method, the length reduction due to the twisting process is such that the distance between the chucks of one of the chucks constituting the pair of chucks or the pair of chucks is the same. It is characterized by moving in the direction of decreasing to compensate.

  Further, in the steel cord manufacturing method, the rubber sheet manufacturing step is performed continuously with the cord body forming step.

  Furthermore, a tire is manufactured using the rubber sheet manufactured by said manufacturing method.

  The rubber sheet for constituting a tire according to the present invention is formed by bending one cord body with a predetermined width on one plane, for example, zigzag or U-shape, to form a planar cord body, which is formed into upper and lower sheet shapes. Since it is the structure inserted | pinched with the rubber body, the steel code | cord | chord is continuous in a rubber sheet, and there is no location cut | disconnected. Therefore, tires produced by pasting these rubber sheets together to create a tire prototype and then vulcanizing it at high temperature and pressure after placing it in the mold must be exposed at the shoulder and ply turn-up parts. No rubber non-bonding at these locations can be prevented.

  In addition, since the cord is continuous inside the tire, the effect of the rigidity possessed by the reinforcing material can be fully exerted, the resistance to deformation can be increased, and the cornering force of the tire can be prevented from being lowered. Wear can be prevented and the life of the tire can be improved.

  The production method of the stranded wire of the present invention is different from the conventional mass production type in that the stranded wire is alternately formed by the stranded wire processing by a simple stranded wire processing machine with the untwisted portion as a boundary. Since the steel cord having a repetitive shape is manufactured, according to the manufacturing method of the present invention, it is possible not only to manufacture a necessary amount of steel cord at a required place but also to twist by a simple stranded wire processing machine. Since it is wire processing, the equipment cost can be reduced and the energy consumption for stranded wire processing can be extremely reduced.

  In addition, by adjusting the distance between the pair of chucks, and further adjusting the rotation direction and number of rotations of the third chuck, it is possible to easily cope with the production of the steel cord corresponding to the tire specifications. It is possible to deal with a variety of products and a small amount of production, that is, a small lot production method at a low cost.

  Furthermore, since the above rubber sheet manufacturing process is performed continuously with the above-described cord body creation process, it is possible to reduce the space for a rubber sheet manufacturing apparatus as a tire component.

Hereinafter, the production method of the present invention will be described with reference to an example of an apparatus suitable for its implementation.
FIG. 1 is a system diagram conceptually showing a rubber sheet manufacturing method of the present invention. In FIG. 1, reference numeral 100 denotes a twisting process, reference numeral 200 denotes a molding process, and reference numeral 300 denotes a rubber sheet manufacturing process. In addition, the cord body forming process is formed by the twisting process 100 and the molding process 200.

FIG. 2 is a schematic view showing an example of the twisting process 100. In FIG. 2, reference numeral 1 denotes a strand, and a plurality of strands 1 are pulled out from the reel 8 while being loaded with tension. The individual wires 1 are arranged on the separating plate 2 so that the arrangement of the mutual wires is not changed, and a certain length is drawn and stopped by the drawing roller 4 which also serves as a feed-out. Here, the fixed length is a length corresponding to an interval between a chuck 3a and a chuck 3b described later.
The plurality of strands 1 may be a combination of a plurality of strands and a strand cord, or may be a plurality of strand cords.

A plurality of strands 1 (wire bundle 1a) that have been pulled out for a fixed length and stopped are a pair of chucks 3a and 3b, and a third chuck 3c disposed at substantially the center of the same pair of chucks 3a and 3b. The plurality of strands 1 are gripped with such a strength that they cannot freely rotate.
The distance between the chuck 3a and the chuck 3c (and the distance between the chuck 3b and the chuck 3c) is a length that takes into account the reduction in the length of the steel cord (twisting reduction) after the end of the twisting process. This is the same length as the steel cord from one end to the other end in consideration of the bias angle of the reinforcing layer embedded in the tire.

  In the example of FIG. 2, the downstream chuck 3 b is attached to the base 7 so as to be movable in the left-right direction in FIG. 2 in order to compensate for twisting in the twisting process. Reference numeral 6 denotes a return spring when the grip is released. The upstream chuck 3a may be movable, and both chucks 3a and 3b may be movable. In any case, the movable chuck is provided with a return spring 6 at the time of releasing the grip. Yes.

  After gripping the wire bundle 1a with the pair of chucks 3a, 3b and the third chuck 3c at a strength that cannot be freely rotated at three locations, the chuck 3c is rotated. The wire bundle 1a is twisted by rotating the chuck 3c, and the wire bundle 1a between the three chucks becomes a steel cord twisted in the S direction and the Z direction. That is, a steel cord twisted with “S twist” on the left side and “Z twist” on the right side with the third chuck 3c interposed therebetween is obtained. Needless to say, when the rotation direction of the third chuck 3c is set to be opposite, the left and right twists can be reversed.

After the rotation based on the specifications required for the steel cord, the rotation of the third chuck 3c is once stopped, and then the third chuck 3c is reversely rotated in order to remove the residual stress of torsion.
Next, the gripping of the chucks 3a, 3c and the third chuck 3c is released, and the steel cord 5 is pulled out between the pair of chucks 3a, 3b by driving the pulling roller 4. As a result, the next strand bundle 1a is continuously fed between the chucks 3a and 3b. When the gripping of the chucks 3 a and 3 b and the third chuck 3 c is released, the moved chuck 3 b returns to the original position by the restoring force of the return spring 6.

  In the steel cord manufacturing method, the means for removing the residual stress of torsion is a mechanism capable of releasing the third chuck 3c after twisting, and the residual twist is removed using the return force of the steel cord. Good.

The drawn steel cord 5 has a shape in which S-twisted portions and Z-twisted portions are alternately present with a boundary held by the third chuck 3c as a boundary.
By repeating this process, a steel cord in which S-twisted steel cords and Z-twisted steel cords having a predetermined length are alternately formed can be manufactured.
The steel cord 5 manufactured in this way is sequentially sent to a molding process 200 that is continuous with the twisting process 100.

  FIG. 3 is a plan view showing an example of a bending apparatus A suitable for the molding process 200, and FIG. 4 is a side view of a Z portion in FIG.

Next, the molding process 200 will be described with reference to FIGS.
The steel cord 5 twisted in the twisting process 100 is drawn out by a pair of delivery rollers 4 (same as that shown in FIG. 2) (see FIG. 3), and the bending rollers 12 and 13 while keeping the tension constant by the dancer roller 11. 5 and is bent between the concave portion provided in the molding roller 20 shown in FIG. 5 and the convex portion provided in the molding roller 30. The part to be bent is a non-twisted part held by the chuck in the twisting process. The distance and the feed speed of the bending devices 12 and 13 are adjusted so that they can be bent at the untwisted portion.
Reference numeral 15 in FIGS. 3 and 4 is for preventing the cord from being twisted when the grip portion is bent. Reference numeral 14 denotes a feed roller.

  Since the molding roller 20 and the molding roller 30 of the folding device 12 and the folding device 13 are provided on the side where the concave portion 24 and the convex portion 34 face each other, the direction in which the steel cord 5 is folded is reversed, and as a whole It is formed on a flat cord body 16 (see FIG. 4) formed in a so-called zigzag shape in which peaks and valleys are continuous on one plane.

The molding roller 20 has a groove 22 formed on the surface of the roller shaft 21 as shown in a plan sectional view in FIG. 5A and a side sectional view in FIG. A recess molding metal fitting 23 into which a recess 24 as shown is press-fitted is fitted and fixed with a screw 25.
The molding roller 30 has a groove 32 formed on the surface of the roller shaft 31, as shown in a plan sectional view in FIG. 5 (c) and a side sectional view in FIG. 5 (d). This is a structure in which a convex part molding metal fitting 33 into which a convex part 34 as shown in FIG.

  Since the convex portion 34 of the convex mold fitting 33 is fitted into the concave portion 24 of the concave mold fixture 23 by the rotation of the rolls 20 and 30, and the cord is molded, the convex portion fits smoothly along the rotation. As shown in FIG. 2, the convex part imposing metal fitting 33 is attached to the roller shaft 31 with a screw 35 so as to be suspended.

  The bending device 13 has the same configuration as this, but as shown in FIG. 4, the shaping roller 20 and the roller 30 are provided on the sides facing each other.

In the above description, the molding roller 20 is on the concave portion side and the molding roller 30 is on the convex portion side, but it goes without saying that the same effect can be obtained even in the reverse case.
And a pair of shaping | molding rollers 20 and 30 are connected with the gears 26 and 36 so that it may rotate at the same speed in conjunction.

  As shown in FIG. 6A, the concave portion 24 provided in the concave molding metal fitting 23 to be mounted on the molding roller 20 includes a molding portion 23a and a guide portion 23b. The width x of the molding portion 23a is set to x = y + 2φ, where y is the width of the convex portion 34 of the convex portion mounting metal fitting 33 and φ is the diameter of the cord, and the width of the guide portion 23b is the width of the molding portion 23a. It is wider than x and has a shape that expands in a tapered shape and maximizes at the opening (the bottom surface in FIG. 6A).

  The depth of the concave portion 24 of the concave mold fitting 23 is substantially the same as the height of the convex portion 34 of the convex mold fitting 33, and the depth of the mold portion 23a and the guide portion 23b is also similar. The bottom shape of the recess 24 is preferably a smooth R shape.

3 and FIG. 4, the drawing roller 4 (see FIG. 3) is pulled out and the dancer roller 11 feeds the folding devices 12 and 13 while keeping the tension constant, and the folding device 12 and the molding rollers of the folding device 13 are used. The steel cord 5 is molded by being sandwiched between the 20 concave portions and the convex portion of the molding roller 30.
Since the molding roller 20 and the molding roller 30 of the folding device 12 and the folding device 13 are provided on the side where the concave portion 24 and the convex portion 34 (see FIG. 5) face each other, the folding direction is reversed, and the whole As shown in FIG. 4, a flat cord body 16 (see FIG. 4) is formed in a so-called zigzag shape in which peaks and valleys are continuous on one plane.

  The period of bending with the molding roller depends on the specifications of the tire in which the rubber sheet is used. The change in the length from one end of the cord to the other end in accordance with the change in the tire specification can be changed by changing the distance between the folding device 12 and the folding device 13 or by changing the feeding speed of the cord. it can.

  FIG. 7 shows an example of a cross-sectional shape of the convex portion 34 of the molding roller 30. When the convex portion 34 shown in FIG. 7A is bent, the cord 16 becomes an acute angle shape shown in FIG. When the bending process is performed by the convex portion 34 shown in b), the cord 16 is bent into a stepped bending shape shown in FIG. In the case of a symmetrical protrusion as shown in FIG. 7C, the bent portion of the cord has a gentle shape.

FIG. 11 shows an example of a rubber sheet made of a cord body that is bent by the bending apparatus A, and the cord body is shown by a dotted line in FIG. Rubber sheet C ₁ shown in (a) is a bent portion is configured to sandwich the cord member a ₁ of sharp zigzag in a pair of rubber sheets C _0, the rubber sheet C ₂ is bent portion shown in (b) the U-shaped cord member a ₂ is sandwiched a pair of rubber sheets C _0.
The rubber sheets C ₁ and C ₂ shown in FIG. 11 are manufactured in accordance with the tire specifications in terms of the distance between the cords to be sandwiched, the bias angle of the cords, or the width of the cord body. Is put in a mold and vulcanized at high temperature and pressure to produce a tire.

The cord body 16 that has been die-formed by the above-described bending apparatus A (for example, bent in a zigzag shape) is subjected to a rubber sheet manufacturing process in the next process.
9 and 10 show an apparatus suitable for the rubber sheet manufacturing process. The rubber sheet C is formed by sandwiching the cord body 16 between the pair of sheet-like rubber bodies 72a and 72b by this apparatus (the apparatus shown in FIGS. 9 and 10).

  The cord body 16 bent in a zigzag shape by the cord folding apparatus A shown in FIGS. 3 and 4 is provided in the upstream portion B (left side in FIGS. 9 and 10) of the rubber sheet manufacturing apparatus shown in FIGS. Further, the paper is fed onto the fixed horizontal plate 51 by a feeding device 54 (same as the feeding roller 14 in FIGS. 3 and 4 when connected to the cord bending device A).

  A pair of conveyor belts 52, 52 are provided close to both sides of the fixed horizontal plate 51, and a cord body that has been fed onto the fixed horizontal plate 51 by the feeding device 54 is provided on the conveyor belts 52, 52. In order to prevent a from overlapping, a pin 53 is erected. Then, the pin 53 hooks the bent portion P of the cord body 16, and the cord body 16 is sequentially transferred downstream (in the direction of the arrow Y in the figure) while preventing the cord body a from overlapping.

  A cord aligning portion 60 is provided at the downstream side, and the cord body 16 sent to the cord aligning portion 60 is a set of conveyor belts 62a and 62b provided in the cord aligning portion 60. The bent part P of the cord body 16 is hooked on the top 63 standing upright and moved to the downstream side.

  Since the left and right conveyor belts 62a and 62b are configured to have a speed difference, the angle of the cord gradually changes with respect to the movement direction of the cord body to form an angle for embedding the cord. In this way, by applying tension to the cord in a state where the embedding angle is obtained, the cords before rubber embedding are aligned.

The code body 16 aligned with a desired embedding angle moves to the dust sheet manufacturing apparatus 70. In the rubber sheet manufacturing apparatus 70, the cord body 16 is subjected to sheeting by a pair of sheet-like rubber bodies 72a and 72b from above and below by the rolling rollers 71a and 71b, and further, the rolling roller 71a, downstream provided with cord retention roller 73a of 71b, by pressing the rubber sheet C ₀ again 73b, a rubber sheet C can be obtained more stable.

The folded portion P of the cord body 16 is exposed on both sides of the rubber sheet C, but if one of the sheet-like rubber bodies 72a and 72b is made wider than the width of the cord body 16, the surplus portion is increased. Since both ends of the rubber sheet C ₀ are rolled up, a rubber sheet having a structure in which the entire rubber sheet C is covered with a sheet-like rubber body can be obtained.

  The rubber sheet of the present invention is determined by tire specifications, and a desired cord body width can be obtained by changing the distance between the folding devices 12 and 13 in the cord folding device A or changing the cord feed speed. Further, the desired cord body interval can be obtained by adjusting the speed of the conveyor belts 62a and 62b in the apparatus B, and the desired cord bias angle can be obtained by adjusting the speed difference between the conveyor belts 62a and 62b. .

As described above, according to the present invention, stranded wire processing of a steel cord can minimize energy loss.
In addition, the initial equipment cost for stranded wire processing and calendering can be minimized, and a necessary amount can be produced at a required place, so that all losses can be minimized as compared with the conventional method.
Furthermore, the calender sheet produced by this production method has excellent resistance to deformation because the steel cord in the calender sheet has no cut portion, and therefore no part that does not adhere, and is a continuous body. Expected to be a safer tire with longer tire life.

It is a systematic diagram which shows notionally the manufacturing method of the rubber sheet of this invention. It is a systematic diagram conceptually showing a twisting process. It is a schematic plan view of a cord bending apparatus. It is a schematic side view of the Z section of FIG. (A), (c) is a plane sectional view of the roller attached to a cord folding device, (b), (d) is the side sectional view. (A) is a perspective view of the recessed part shaping | molding metal fitting press-fitted in the recessed part 24, (b) is a perspective view of the convex part shaping | molding metal fitting which press-fitted the convex part 34. FIG. (A), (b), (c) is the side view to which the protrusion of the bending apparatus was expanded. (A), (b) is a top view of the bending part of the code | cord | chord bent by the bending apparatus. It is a schematic plan view of a rubber sheet manufacturing apparatus. It is the same side view. (A), (b) is a top view which shows one example of the rubber sheet manufactured by the manufacturing method of this invention.

Explanation of symbols

1: Wire 1a: Wire bundle 2: Separation plate 3a, 3b: Pair of chucks 3c: Third chuck 4: Feeding roller 5: Steel cord 6: Spring for return 7: Base 8: Feeding reel 12, 13: Bending device 16: Cord body 20, 30: Molding roller 51: Fixed horizontal plate 52: Conveyor belt 53: Pin 54: Feeding device 60: Cord aligning portion 62a, 62b: Conveyor belt 63: Top 70: Rubber sheet manufacturing device 71a 71b: Rolling roller 72a: Sheet rubber body 73a, 73b: Cord fixing roller 100: Twisting process 200: Molding process 300: Rubber sheet manufacturing process C, C ₁ , C ₂ : Rubber sheet Co Sheet rubber body P: Bending part of cord body

Claims (4)

A method for producing a rubber sheet as a tire reinforcement,
Pull out a plurality of strands or a plurality of strands and a strand cord or a plurality of strand cords,
Grip this with a pair of chucks and a third chuck disposed at approximately the center of the same pair of chucks,
By rotating the third chuck, the plurality of strands or the plurality of strands and the strand cord or the plurality of strand cords are twisted to form a steel cord, and then the residual stress of the twist is reduced. Take away,
Next, the steel cord is pulled out between the pair of chucks, and by repeating this, a steel cord in which the twisting direction alternately exists in the S direction and the Z direction is created,
The flat cord body is formed by bending the portion (untwisted portion) gripped by the chuck of the steel cord thus created on one plane,
A rubber sheet manufacturing method comprising manufacturing a rubber sheet as a tire reinforcing material through a rubber sheet manufacturing process in which the cord body is sandwiched from above and below by a sheet-like rubber body.   The decrease in length due to the torsion processing is compensated by moving either one of the chucks constituting the pair of chucks or both chucks in a direction in which the distance between the same pair of chucks is reduced. The method for producing a rubber sheet according to claim 1.   The method for producing a rubber sheet according to any one of claims 1 and 2, wherein the rubber sheet production step is performed continuously with the cord body forming step.   The tire using the rubber sheet manufactured by the manufacturing method of any one of Claims 1-3.