JP2014233911A - Rubber member for tire and method for manufacturing the same and method for manufacturing tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rubber member for a tire that can efficiently provide a tire which can prevent a rubber strip from laterally shaking when cutting and winding without deteriorating uniformity and has excellent quality, a method for manufacturing the same and a method for manufacturing a tire.SOLUTION: Provided are the rubber member for a tire formed by winding spirally an unvulcanized rubber strip around an object to be wound to be laminated with each other, where at least one end of the rubber strip is formed in a V-letter like valley shape or in a reversed V-letter like mountain shape in a planar view and is symmetric in a width direction, a method for manufacturing the rubber material for a tire and a method for manufacturing a tire using the rubber material for a tire.

Description

  The present invention relates to a tire rubber member formed by winding an unvulcanized rubber strip spirally around a body to be wound and laminating it, a method for manufacturing the same, and a method for manufacturing a tire.

  In recent years, when manufacturing pneumatic tires, long rubber strips are spirally wound around a body to be wound, such as a molding drum, and laminated to create tread rubber, sidewall rubber, clinch rubber, cushion rubber, inner liner rubber, etc. A strip wind method for forming a tire rubber member (hereinafter also simply referred to as “rubber member”) is widely adopted.

  As shown in FIGS. 4A and 4B, the rubber member formed by the strip wind method is formed with a step at the positions of the end portions e1 and e2 of the rubber strip. At this time, if the end edges e1 and e2 of the rubber strip are formed at right angles to the side edges, a step extending parallel to the axial direction of the tire is formed. There is a possibility of affecting the uniformity as the mass changes.

  Therefore, conventionally, when cutting the rubber strip, a cutting blade is inserted obliquely with respect to the running direction, and as shown in FIG. 5, the rubber strip S extends obliquely at a predetermined inclination angle α as shown in FIG. The inclined edge E3 was formed. Thereby, a level | step difference will incline and extend with respect to a tire axial direction, the mass in a level | step difference will disperse | distribute to the circumferential direction, and the fall of uniformity can be suppressed (for example, patent document 1).

JP 2009-73177 A

  However, since the rubber strip S having the inclined edge E3 as described above is produced by moving the cutter blade obliquely from one side edge to the other side edge and cutting the rubber strip S, the rubber strip S in the traveling direction is cut. On the other hand, the cutter blade hits asymmetrically left and right and easily swings from side to side.

  Further, when the cut rubber strip S is supplied to the molding drum, the ground contact area and the ground resistance with the applicator are not uniform left and right. easy. And since the rubber strip S swung around from side to side needs to be repositioned, work efficiency is lowered. In addition, the gauge of the manufactured tire rubber member may deviate from the target gauge, which may affect the uniformity.

  Therefore, the present invention provides a rubber member for a tire that can efficiently provide a tire with excellent quality by preventing the rubber strip from swinging left and right at the time of cutting or winding without reducing uniformity. It is an object of the present invention to provide a manufacturing method and a tire manufacturing method.

The invention described in claim 1
A rubber member for a tire formed by spirally winding an unvulcanized rubber strip around a body to be wound, and laminating,
At least one end portion of the rubber strip has a V-shaped valley shape or an inverted V-shaped mountain shape in plan view, and is a tire rubber member characterized by being symmetrical in the width direction.

The invention described in claim 2
2. The tire rubber member according to claim 1, wherein both ends of the rubber strip are V-shaped valley-shaped or inverted V-shaped mountain-shaped in a plan view.

The invention according to claim 3
One end of the rubber strip has a V-shaped valley shape in plan view,
3. The tire rubber member according to claim 1, wherein the other end portion of the rubber strip has an inverted V-shaped mountain shape in plan view.

The invention according to claim 4
The tire according to any one of claims 1 to 3, wherein the V-shaped valley shape is formed at an angle of 10 to 70 degrees with respect to a side edge of the rubber strip. Rubber member.

The invention described in claim 5
One side edge of the rubber strip on the winding start side is used as a side edge, and the other side edge is sequentially covered at least partially by one side edge of the rubber strip wound next. The rubber member for tire according to any one of claims 1 to 4, wherein the tire rubber member is formed by being spirally wound and laminated.

The invention described in claim 6
A method for producing a rubber member for a tire, comprising: a cutting step of cutting the rubber strip along the width direction; and a winding step of spirally winding the laminated rubber strip around the wound body, and laminating.
In the cutting step, at least one end portion of the rubber strip is a V-shaped valley shape or an inverted V-shaped mountain shape in plan view, and the elongated shape is symmetric in the width direction. A rubber sheet for tires is produced by cutting the rubber sheet.

The invention described in claim 7
A raw tire molding step of molding a raw tire using the tire rubber member manufactured by the method for manufacturing a tire rubber member according to claim 6;
And a vulcanization step for vulcanizing the green tire.

  According to the present invention, a rubber member for a tire capable of efficiently providing a tire with excellent quality by preventing the rubber strip from swinging left and right at the time of cutting or winding without reducing uniformity. The manufacturing method and the manufacturing method of a tire can be provided.

It is a top view of the both ends of the rubber strip used for the rubber member for tires concerning one embodiment of the present invention. It is a top view of the trough-shaped edge part of the rubber strip used for the rubber member for tires concerning one embodiment of the present invention. It is sectional drawing of the rubber member for tires which concerns on one embodiment of this invention. (A) is sectional drawing of the rubber strip in the winding start side of the rubber member for tires, (b) is sectional drawing in the winding end side. It is a top view of the edge part of the conventional rubber strip.

  Hereinafter, the present invention will be described based on embodiments with reference to the drawings.

1. Tire Rubber Member First, a tire rubber member according to an embodiment of the present invention will be described.

  FIG. 1 is a plan view of both end portions of a rubber strip used for a tire rubber member according to the present embodiment.

  As shown in FIG. 1, in the rubber member for tire according to the present embodiment, one end e1 of the rubber strip S has a V-shaped valley shape in plan view, and the other end e2 is reversed in plan view. V-shaped mountain shape.

  The valley-shaped end portion e1 and the mountain-shaped end portion e2 are symmetric in the width direction. Specifically, in the case of the V-shaped valley-shaped end portion e1, as shown in FIG. 2, it passes through the center of the width of the rubber strip S and runs along the running direction (longitudinal direction of the rubber strip S) at the time of application. The bottom of the edge E4 of the end e1 is disposed on the center line CL that extends. Although not shown, in the case of the inverted V-shaped mountain-shaped end e2, the vertex of the edge E5 of the end e2 is arranged near the center line CL.

2. Method for Producing Tire Rubber Member Next, a method for producing a tire rubber member according to the present embodiment will be described.

  First, a long rubber strip is cut into a fixed length so as to form both end portions as shown in FIG.

  Specifically, using a rotary cutter, the long strip is cut in the width direction with a predetermined length so that the end of the cut rubber strip has a V shape in plan view.

  At this time, since the cutter blade contacts the left and right uniformly to cut the rubber strip, it is possible to appropriately suppress the position of the rubber strip from swinging left and right.

  The rubber strip S thus produced has a V-shaped valley shape in which one end e1 is bilaterally symmetrical in the width direction, and an inverted V-shape in which the other end e2 is bilaterally symmetrical in the width direction. Become a mountain.

  Next, the produced rubber strip S is spirally wound around a forming drum as a wound body. Here, the valley-shaped end portion e1 is on the winding start side, and the mountain-shaped end portion e2 is on the winding end side.

  First, the rubber strip S is placed on an applicator (not shown) for supplying the rubber strip S to the molding drum, conveyed to the molding drum, and the valley-shaped end e1 is attached to the molding drum.

  At this time, each of the end portion e1 and the end portion e2 is bilaterally symmetric with respect to the traveling direction, and the difference between the right and left in the grounding area and grounding resistance with the applicator is reduced. It is suppressed. Thereby, the running stability of the rubber strip S can be improved, and the sticking accuracy can be improved.

  Then, as shown in FIG. 3, the end e1 of the rubber strip S is attached to the molding drum U so that one side edge E1 of the rubber strip S becomes the outer edge of the tire rubber member R, and one side edge The rubber member R for the tire is formed by sequentially winding the rubber strip S in a spiral shape so that at least a part of the edge of the end e1 is covered from E1 toward the other side edge E2.

  The tire rubber member R has a step formed at the positions of the end portion e1 and the end portion e2 in a V shape, so that the step is similar to the case having the inclined edge E3 as shown in FIG. Is easily dispersed in the tire circumferential direction, and a decrease in uniformity can be appropriately suppressed.

  A tire excellent in uniformity can be manufactured by molding and vulcanizing a raw tire using such a tire rubber member R.

  As described above, according to the present embodiment, when the rubber strip is cut or wound around the molding drum, the rubber strip is prevented from being shaken to the left and right to improve work efficiency, and the uniformity due to the step is improved. Since the decrease can be suppressed, an excellent quality tire can be efficiently manufactured.

  If the angles (inclination angles) α1 and α2 formed between the edge E4 of the valley-shaped end e1 and the side edges E1 and E2 of the rubber strip S are less than 10 degrees, the rigidity of the valley-shaped end e1 Decreases and the shape becomes difficult to stabilize, making it difficult to handle when winding. On the other hand, if it exceeds 70 degrees, the shape of both end portions becomes nearly perpendicular to the side edge of the rubber strip, and it becomes difficult to disperse the mass of the step in the tire circumferential direction. Therefore, it is preferable that the inclination angles α1 and α2 are in the range of 10 to 70 degrees.

  In addition, the inclination angles α1 and α2 do not need to be completely the same, and may be different within a range in which left and right deflection does not occur when the rubber strip is cut or wound around a forming drum.

  In the above description, the winding is started from the valley-shaped end e1. However, the present invention is not limited to this, and the winding may be started from the mountain-shaped end e2.

  Further, in the above description, one end e1 of the rubber strip S is formed in a V-shaped valley shape, and the other end e2 is formed in an inverted V-shaped mountain shape. It is not limited to this. For example, only one end is formed in a valley shape or a mountain shape, or both end portions are formed in a valley shape, or both end portions are formed in a mountain shape. However, it is possible to appropriately suppress the left-right deflection during the manufacturing, and to obtain the same effect as the effect of the present embodiment.

  Hereinafter, the present invention will be described more specifically by experimental examples.

1. Production of tires (Examples 1 to 4)
As shown in FIG. 1, a rubber strip S that is cut into a valley and has a symmetrical V-shaped valley-shaped end e1 and an inverted V-shaped peak-shaped end e2 is produced, and this is formed into a spiral shape. A pneumatic tire for a passenger car having a size of 215 / 45ZR17 was manufactured using the clinch rubber that was wound. As the rubber strip, a ribbon-shaped rubber strip having a width of 10 mm and a thickness of 1.0 mm was used. In addition, the inclination angles α1 and α2 of the valley-shaped end portion e1 in Examples 1 to 4 are as shown in Table 1, respectively.

(Comparative Examples 1-3)
As shown in FIG. 5, a pneumatic tire for a passenger car was manufactured in the same manner as in the example except that a rubber strip S that was cut obliquely and both end portions had inclined edges E3 was used. In addition, inclination angle (alpha) of the inclination edge E3 of Comparative Examples 1-3 was as having shown in Table 1, respectively.

2. Evaluation method and evaluation results (Examples and Comparative Examples)
For each of the examples and comparative examples, 100 pneumatic tires were produced, and the tire uniformity and runout on the rubber strip application end side were evaluated.

(1) Evaluation of uniformity Radial force variation (RFV), which is a fluctuation component in the tire radial direction at the time of rotation, was measured in accordance with JASO C607: 2000 uniformity test conditions, and at low speed rotation (6.8 km / H). Evaluation was based on overall size. In addition, a tire with a smaller RFV value has better uniformity. The evaluation results are shown in Table 1.

(2) Evaluation of sticking strip runout The deviation of the end portion from the center line of the rubber strip is measured N = 20 times for each tire, and the difference (R) between the maximum value and the minimum value in each tire is obtained. And the average of R was calculated | required about the comparative example, and it evaluated as sticking strip runout (mm). The evaluation results are shown in Table 1.

  From Table 1, Examples 1-4 have less fluctuation of the adhesive strip compared with Comparative Examples 1-3, and in particular, in Examples 1-3 where the inclination angle is 10 to 70 degrees, It was confirmed that the shake was very small.

  Further, the RFVs of Examples 1 to 4 are the same as those of Comparative Examples 1 to 3, and even when both ends of the rubber strip are formed in a mountain shape and a valley shape, the uniformity is the same as when both ends are inclined. It has been confirmed that excellent tires can be manufactured and can contribute to improvement of manufacturing efficiency.

  While the present invention has been described based on the embodiments, the present invention is not limited to the above-described embodiments. Various modifications can be made to the above-described embodiment within the same and equivalent scope as the present invention.

CL Center line E1, E2 Side edge E3 Inclined edge E4 End edge of valley-shaped end E5 End edge of mountain-shaped end e1, e2 End R Rubber member for tire S Rubber strip U Molding drum α, α1, α2 tilt angle

Claims (7)

A rubber member for a tire formed by spirally winding an unvulcanized rubber strip around a body to be wound, and laminating,
A rubber member for a tire, wherein at least one end of the rubber strip has a V-shaped valley shape or an inverted V-shaped mountain shape in plan view and is symmetrical in the width direction.   2. The rubber member for tire according to claim 1, wherein both ends of the rubber strip have a V-shaped valley shape or an inverted V-shaped mountain shape in plan view. One end of the rubber strip has a V-shaped valley shape in plan view,
The rubber member for a tire according to claim 1 or 2, wherein the other end portion of the rubber strip has an inverted V-shaped mountain shape in plan view.   The tire according to any one of claims 1 to 3, wherein the V-shaped valley shape is formed at an angle of 10 to 70 degrees with respect to a side edge of the rubber strip. Rubber member. One side edge of the rubber strip on the winding start side is used as a side edge, and the other side edge is sequentially covered at least partially by one side edge of the rubber strip wound next. The rubber member for a tire according to any one of claims 1 to 4, wherein the tire rubber member is formed by being spirally wound and laminated. A method for producing a rubber member for a tire, comprising: a cutting step of cutting the rubber strip along the width direction; and a winding step of spirally winding the laminated rubber strip around the wound body, and laminating.
In the cutting step, at least one end portion of the rubber strip is a V-shaped valley shape or an inverted V-shaped mountain shape in plan view, and the elongated shape is symmetric in the width direction. A method for producing a rubber member for a tire, comprising cutting the rubber sheet. A raw tire molding step of molding a raw tire using the tire rubber member manufactured by the method for manufacturing a tire rubber member according to claim 6;
And a vulcanizing step for vulcanizing the green tire.

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