JP2009143165A - Manufacturing method and manufacturing apparatus for tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method and a manufacturing apparatus for a tire which reduce the contraction amount of rubber after being pasted to a tire molding drum (core drum). <P>SOLUTION: Tension is not applied to a rubber strip material between the core drum and a roller die 12 by eliminating a speed difference between the wind-up speed V1 of the core drum and the pull-out speed V2 of the roller die 12. Also, the cross sectional area of the rubber strip material which has been extruded from a mouthpiece 15 is made smaller by accelerating the wind-up speed V1 and the pull-out speed V2 higher than an extruding speed V3, and stretching the rubber strip material between the mouthpiece 15 and the roller die 12 by applying tension to the rubber strip material. The extruding speed V3 from the mouthpiece 15 is higher than a conventional extruding speed, and therefore, the pulling amount becomes V2/V3<V2/V3', and the pulling amount and the contraction amount in this embodiment can be reduced. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method and an apparatus for manufacturing a tire in which rubber extruded from a base via a roller die is wound around a drum while being pulled.

  Generally, a tire is composed of a plurality of rubber members for tires. For example, each part such as an inner liner, a tread part, and a sidewall part is formed of unvulcanized rubber corresponding to required characteristics. . The rubber member constituting each part of these tires is obtained by extruding unvulcanized rubber from an extruder equipped with a die (die) corresponding to the cross-sectional shape of each rubber member. It is formed by cutting to a length or winding it on a tire molding drum.

  When the rubber is wound around the tire molding drum by the extruder, the rubber extrusion speed of the extruder and the winding speed around the tire molding drum are adjusted so that the rubber extruded from the die has a desired width corresponding to each rubber member. Winding is performed while adjusting the width of the rubber by controlling and adjusting the tension applied to the rubber to expand and contract (see, for example, Patent Document 1).

  However, when winding around a tire molding drum while adjusting the tension applied to the rubber in this way, if the tension is applied too much, the shrinkage of the rubber after winding will be large and the shape of each rubber member will not be stable, and the tire of the desired shape May not be obtained.

Therefore, the tension applied to the rubber is reduced and wound around a tire molding drum (core drum) while suppressing the shrinkage of the rubber, but the difference between the extrusion speed and the winding speed is reduced to reduce the tension. If the rubber is reduced, the cross-sectional width (cross-sectional area) of the rubber will widen. Therefore, when this rubber is stacked and pasted on the tire molding drum, it is difficult to accurately form the detailed shape of the rubber member. Occurs.
JP 2006-335022 A

  The present invention has been made to solve the above-described conventional problems, and its purpose is to suppress the expansion of the cross-sectional area of the rubber during winding, and to stick it to the tire molding drum with a simple configuration. It is to reduce the shrinkage amount of the later rubber.

The invention of the present application is a method for manufacturing a tire in which a rubber member extruded from a die of an extruder is pulled out and wound around a support, the step of extruding the rubber member from the die at a predetermined extrusion speed, and the extruded rubber member A step of drawing out at a speed faster than the predetermined speed, and a step of winding the drawn rubber material around the support, wherein the cross-sectional area of the rubber member at the time of winding on the support is S1, the opening of the base When the partial cross-sectional area is S3, the extrusion speed of the rubber member from the base and the drawing speed are controlled so that S3 / S1 is 3.5 to 2.0.
Another invention of the present application is a method of manufacturing a tire in which a rubber member extruded from a die of an extruder is pulled out and wound around a support, the step of extruding the rubber member from the die at a predetermined extrusion speed, and the extruded rubber A step of pulling out the member at a speed higher than the predetermined speed, and a step of winding the drawn rubber material around the support, wherein the cross-sectional area of the rubber member when wound on the support is S1, When the opening cross-sectional area of the base is S3, the extrusion speed and the drawing speed of the rubber member from the base are controlled so that S3 / S1 is 3.3 to 2.7.
Another invention of the present application is a base for extruding a rubber member in a predetermined cross-sectional shape, a pulling means for pulling out the rubber member pushed out from the base, a support for winding the rubber member pulled out by the pulling means, And a control means for controlling the speed at which the rubber member is pushed out from the base and the speed at which the drawing means pulls out the rubber member from the base, and when the winding is performed on the support body. When the cross-sectional area of the rubber member is S1 and the opening cross-sectional area of the base is S3, the control means controls the extrusion speed and the drawing speed so that S3 / S1 is 3.5 to 2.0. It is characterized by doing.
Furthermore, another invention of the present application is a base for extruding a rubber member in a predetermined cross-sectional shape, a pulling means for pulling out the rubber member pushed out from the base, a support for winding up the rubber member pulled out by the pulling means, And a control means for controlling the speed at which the rubber member is pushed out from the base and the speed at which the drawing means pulls out the rubber member from the base, and when the winding is performed on the support body. When the cross-sectional area of the rubber member is S1 and the cross-sectional area of the opening of the base is S3, the control means controls the extrusion speed and the drawing speed so that S3 / S1 is 3.3 to 2.7. It is characterized by doing.

  ADVANTAGE OF THE INVENTION According to this invention, the shrinkage amount of the rubber | gum after affixing on a tire molding drum can be reduced, and the rubber member and tire of a desired shape can be manufactured stably.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a perspective view of a tire manufacturing apparatus according to this embodiment.
The tire manufacturing apparatus includes a tire molding machine 1 and an extruder 10.
The tire molding machine 1 includes a base 2 that houses a drive mechanism, a rotary shaft 3 that extends horizontally from one side of the base, and that is driven by the drive mechanism, and a support provided at the end of the rotary shaft 3. It consists of a toroidal core drum (laminate) 4 which is the body.
The extruder 10 is arranged with the die facing the core drum 4, and a rubber member (feed rubber) charged into the hopper 11 is molded into a band shape from the die, extruded as a rubber strip material 13, and supplied toward the core drum 4. To do.
In addition, the rubber strip material 13 pushed out from the die is pulled out between the core drum 4 and the die of the extruder 10, and the rubber strip material 13 is pressed against the core drum 4 and the sectional shape thereof is adjusted. A roller die 12 which is an embodiment of the drawing means is provided.

The extruder 10 can move together with the roller die 12 in the rotation center axis direction of the core drum 4 (X direction in the figure) and in the direction perpendicular to the rotation center axis direction (Y direction in the figure), and with respect to the vertical axis (X and Y directions). Thus, the direction of extrusion can be changed by rotating in the θ direction around a right-angled axis).
Therefore, the extruder 10 can supply the rubber strip material 13 from the outer peripheral surface to the side surface of the core drum 4 by changing the position and orientation, and can be wound spirally.

  The molding apparatus 1 includes a drive mechanism such as a drum drive motor that rotates the core drum 4, and the extruder 10 changes the position and orientation of the extruder 10 and the extruder 10 that rotate a screw for extruding rubber. A moving motor for moving is provided. A computer control device 30 for controlling each of these motors is provided, and the control device 30 outputs each control signal to the drum rotation motor driver 31, the extrusion motor driver 32, and the moving motor driver 33, and each driver. Controls driving of the motors.

FIG. 2 is an enlarged view of the die portion of the extruder 10 and the winding portion of the core drum used for manufacturing the bead filler.
The feed rubber thrown into the hopper 11 is pushed out from the base 15 by a fixed amount by a screw and a gear pump (not shown). The extruded rubber is wound around the side surface of the core drum 4 by the rotating roller die 12 and the core drum 4 to produce a bead filler.

Here, in this embodiment, in order to be able to accurately form the detailed shape of the rubber member (for example, a bead filler) of the tire to be manufactured, the opening cross-sectional area of the base 15 of the extruder 10 is reduced. Thus, the cross-sectional area (cross-sectional width) of the extruded rubber is made smaller than before.
That is, the opening cross-sectional area of the base of the conventional apparatus is S3 ′, the extrusion speed (the length of the strip rubber material extruded per unit time) is V3 ′, and the cross-sectional area of the opening of the base 15 of the extruder 10 of the present embodiment. S3 and the extrusion speed is V3, the rubber extrusion rate per unit time (cc / min) is a value obtained by multiplying the opening cross-sectional area (cm ² ) of the die by the extrusion speed (m / min). When the amount of rubber extrusion per unit time is the same in the conventional apparatus and the extruder 10 of this embodiment,
S3 ′ × V3 ′ = S3 × V3 (1)
Where S3 <S3 ′,
V3> V3 '(2)
It becomes. That is, the extrusion speed of the extruder 10 of the present embodiment is higher than that of the conventional one.

FIG. 3 is a diagram for explaining the relationship among the winding speed (m / min) of the core drum 4, the drawing speed (m / min) of the roller die 12 and the rubber extrusion speed (m / min) from the base 15 in this embodiment. is there.
Assuming that the winding speed (m / min) of the core drum 4 is V1, the drawing speed (m / min) of the roller die 12 is V2, and the rubber extrusion speed (m / min) from the base 15 is V3 as described above, V1 = V2 Take up at the same speed. That is, by eliminating the speed difference between the winding speed of the core drum 4 and the drawing speed of the roller die 12, no tension is applied to the rubber strip material 13 between the core drum 4 and the roller die 12.

Further, the winding speed V1 of the core drum 4 and the drawing speed V2 of the roller die 12 are made faster than the extrusion speed V3 as in the conventional case, and the rubber strip material 13 between the die 15 and the roller die 12 is stretched with tension. Thus, the cross-sectional area of the rubber strip member 13 extruded from the base 15 having a smaller opening cross-sectional area than that of the conventional one is further reduced.
Here, the degree to which the rubber strip material 13 is pulled by the roller die 12 due to the tension applied to the rubber strip material 13 between the base 15 and the roller die 12 is as follows.
V2 / V3 (3)
Can be expressed as This value is called the amount of pulling here.
The larger the amount of pulling, the larger the amount of shrinkage after the rubber strip material 13 is wound around the core drum 4.

Here, as described above, the extrusion speed V3 from the base 15 having the opening cross-sectional area smaller than that of the conventional one is higher than the conventional extrusion speed V3 ′ (see the formula (2)), so that the core drum in the conventional apparatus is used. And when the winding speed of the roller die is the same as the winding speed in this embodiment, the relationship between the amount of tension between the conventional apparatus and the apparatus of this embodiment is as follows:
V2 / V3 <V2 / V3 ′ (4)
It becomes.
Therefore, the amount of tension in this embodiment can be reduced as compared with the conventional one, and the shrinkage of the rubber strip material 13 after being wound around the core drum 4 due to this tension can be suppressed.

The bead filler formed by wrapping rubber around the core drum 4 by the above procedure is vulcanized by a vulcanizer together with other rubber members (carcass, tread portion, etc.) formed by the same method to produce a product tire. Become.
The size of the base 15 is determined in consideration of the pressure increase and rubber clogging due to the reduced opening cross-sectional area, and the cross-sectional area of the rubber when wound around the core drum 4. That is, when the cross-sectional area of the rubber when wound around the core drum 4 is S1, the relationship between the opening cross-sectional area S3 of the base 15 and the cross-sectional area S1 of the rubber is S3 / S1 of 3.5 to 2.0, In particular, it is desirable to adjust the size of the die 15 to control the extrusion speed of the die 15 and the drawing speed of the roller die 12 so as to be 3.3 to 2.7.

(Example)
In order to confirm the effect of the present invention, a tire manufacturing apparatus (hereinafter referred to as a tire manufacturing apparatus a) using a base (hereinafter referred to as a base a) that is an embodiment of the present invention and a conventional comparative product (hereinafter referred to as a tire manufacturing apparatus a). The tension amount is compared with a tire manufacturing apparatus (hereinafter referred to as a tire manufacturing apparatus b) using a base b).
In this embodiment, 0.2 cm ² of the opening area of the base a, the opening area of the mouthpiece b and 0.04 cm ^2, rubber extrusion amount per two tire building apparatuses a, b both unit time is the same.
Further, the extrusion speed of the base a is V3a (m / min), the extrusion speed of the base b is V3b (m / min), and the winding speeds (V1 and V2) of the core drum and the roller die of both tire manufacturing apparatuses a and b. Are the same.

Since the rubber extrusion amounts of the tire manufacturing devices a and b are the same, from the above formula (1),
0.04 × V3a = 0.2 × V3b (5)
From the above formula (3), the tire manufacturing device a has a pulling amount of V2 / V3a, and the tire manufacturing device b has a pulling amount of V2 / V3b. Therefore, the ratio of the pull amount of the tire manufacturing apparatus a to the tire manufacturing apparatus b is
V3b / V3a (6)
Therefore, V3b / V3a = 0.2 from Equation (5) and Equation (6).
From the above, it has been found that the pull amount of the tire manufacturing apparatus a is reduced by 80% compared to the conventional tire manufacturing apparatus b.

(Shape change measurement test)
After the rubber was wound around the core drum 4 using the caps a and b to form a bead filler, the bead filler was peeled off from the laminated plate, and the amount of bending (the amount of change in shape) caused by the contraction of each rubber was measured. This test was performed on two types of rubbers (rubber (1) and rubber (2)) having different physical properties.

FIG. 4 is a graph (figure) showing the results of this test.
In this graph, the vertical axis indicates the amount of bending (mm), and the horizontal axis indicates the elapsed time (seconds) after the rubber is peeled off.
As shown in the figure, in the comparison with the same type of rubber, the amount of curvature of the rubber extruded by the base a which is the product of the present invention is always kept below the amount of curvature of the rubber extruded by the base b which is a comparative product. ing.
Further, when the elapsed time is 30 seconds, the difference in the amount of bending between the base a and the base b is the largest, and the amount of bending of the rubber (1) extruded by the base a is the rubber extruded by the conventional base b. It is suppressed by about 10% to 15% as compared with the bending amount of (1), and about 25% is suppressed for rubber (2).

As described above, the tire manufacturing apparatus according to the present embodiment can reduce the amount of pulling and suppress the shrinkage of rubber only by reducing the opening cross-sectional area of the base 15 as compared with the related art.
Further, since the winding speeds (V1 and V2) of the conventional core drum 4 and the die roller 12 are not changed, if the rubber extrusion amount is the same in the conventional apparatus and the extruder 10 of the present embodiment, the core drum 4 is transferred. The time required for sticking rubber is the same as before.
The present invention can be applied to all pull-paste manufacturing methods and members.

  In this embodiment, the rubber strip material is used. However, a rubber strip material cut into a predetermined length may be used.

It is a perspective view of the tire manufacturing apparatus concerning this embodiment. It is an enlarged view of the nozzle | cap | die part of an extruder, and the winding part of a core drum. It is a figure explaining the relationship between the winding speed of a core drum and a roller die, and the rubber extrusion speed from a nozzle | cap | die. It is the graph (diagram) which showed the result of the shape change amount measurement test.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Molding apparatus, 2 ... Base, 3 ... Rotating shaft, 4 ... Core drum, 10 ... Extruder, 11 ... Hopper, 12 ... Roller die, 13 ... Rubber strip material, 15 ... base, 30 ... control device, 31 ... drum rotation motor driver, 32 ... extrusion motor driver, 33 ... moving motor driver.

Claims (6)

A method of manufacturing a tire for pulling out a rubber member extruded from a die of an extruder and winding it on a support,
Extruding a rubber member from the die at a predetermined extrusion speed;
Pulling out the extruded rubber member at a speed faster than the predetermined speed;
Winding the drawn rubber material around the support, and
When the cross-sectional area of the rubber member at the time of winding on the support is S1, and the opening cross-sectional area of the base is S3,
A method for manufacturing a tire, wherein the extrusion speed of the rubber member from the die and the drawing speed are controlled so that S3 / S1 is 3.5 to 2.0. A method of manufacturing a tire for pulling out a rubber member extruded from a die of an extruder and winding it on a support,
Extruding a rubber member from the die at a predetermined extrusion speed;
Pulling out the extruded rubber member at a speed faster than the predetermined speed;
Winding the drawn rubber material around the support, and
When the cross-sectional area of the rubber member at the time of winding on the support is S1, and the opening cross-sectional area of the base is S3,
A method for manufacturing a tire, characterized by controlling an extrusion speed and a drawing speed of a rubber member from the base so that S3 / S1 is 3.3 to 2.7. In the tire manufacturing method according to claim 1 or 2,
A method for manufacturing a tire, wherein the speed at which the rubber member is pulled out from the die in the drawing step and the speed at which the rubber member is wound around the support in the winding step are controlled to be the same speed. A tire manufacturing apparatus comprising: a base that extrudes a rubber member in a predetermined cross-sectional shape; a pull-out means that pulls out the rubber member pushed out from the base; and a support that winds up the rubber member pulled out by the pull-out means. And
Control means for controlling the speed at which the rubber member is pushed out from the base and the speed at which the drawing means pulls out the rubber member from the base;
When the cross-sectional area of the rubber member at the time of winding on the support is S1, and the cross-sectional area of the opening of the base is S3, the control means performs the extrusion so that S3 / S1 is 3.5 to 2.0. A tire manufacturing apparatus that controls a speed and a drawing speed. A tire manufacturing apparatus comprising: a base that extrudes a rubber member in a predetermined cross-sectional shape; a pull-out means that pulls out the rubber member pushed out from the base; and a support that winds up the rubber member pulled out by the pull-out means. And
Control means for controlling the speed at which the rubber member is pushed out from the base and the speed at which the drawing means pulls out the rubber member from the base;
When the cross-sectional area of the rubber member at the time of winding on the support is S1, and the cross-sectional area of the opening of the base is S3, the control means performs the extrusion so that S3 / S1 is 3.3 to 2.7. A tire manufacturing apparatus that controls a speed and a drawing speed. In the tire manufacturing apparatus according to claim 4 or 5,
A method of manufacturing a tire, wherein the control means controls the speed at which the drawing means pulls out the rubber member from the die and the speed at which the support winds up the rubber member to be the same speed.

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