JP6761087B2 - Manufacturing method of presser rollers and tire components - Google Patents

Description

The present disclosure relates to a presser roller and a method of manufacturing a tire component using the presser roller.

As a step of molding the tire constituent member, there is a step of crimping the tread rubber to a member (belt or the like) to be arranged on the inner peripheral side of the tread rubber. In this step, the pressing roller is rolled in the circumferential direction while pressing the outer peripheral surface of the tread rubber.

As schematically shown in FIG. 4, the tread rubber T often has a thick uneven shape in the shoulder region T2 around the tread rubber T than in the central portion T1 in the width direction. When pressed by a roller R having a constant hardness, the pressing force at the thick portion of the tread rubber T becomes high, and the pressing force at the thin portion becomes weak. Then, the pressing force at the center portion T1 (center) in the width direction of the tread rubber T is weak, the pressing force at the shoulder region T2 becomes strong, and forces act on the center CL in the width direction of the tread rubber T from both sides. Therefore, the pressing force is not uniform. If the tread rubber is soft and thin, the rubber is pushed in the direction of weak pressing pressure and wrinkles are formed. In some cases, the center marker of the tread rubber may meander along the circumferential direction, or the center marker of the tread rubber may be displaced. Further, if a force acts on the center of the tread rubber from both sides in the width direction, the air held in the member may not escape and gathers at the center, resulting in molding failure.

As one of the means for bleeding air, Patent Document 1 describes a shaft held at both ends, a tubular elastic body covering the outer periphery of the shaft, and an axial direction supported by the outer peripheral surface of the tubular elastic body. Disclosed is a presser roller having a plurality of rings arranged in the same direction, wherein the plurality of rings gradually decrease in outer diameter from the center in the axial direction to the outside in the axial direction. According to this configuration, the outer diameter of the ring in the center in the axial direction is large, and the outer diameter of the ring becomes smaller toward the outside. Therefore, the convex shape due to the difference in outer diameter directs air from the center to the outside in the axial direction. It is stated that it can be done (see paragraph 0017).

Japanese Unexamined Patent Publication No. 2008-8775

However, the presser roller described in Patent Document 1 has a step on the outer surface of the roller formed on the outer peripheral surfaces of the plurality of rings, and if even a slight axial force acts during rolling, the presser roller will be caught in the step. The ring shakes in the axial direction and the pressing force is released, so that the tread rubber cannot be pressed properly.

The present disclosure has focused on such a problem, and the purpose of the present disclosure is to appropriately press the tread rubber even if a force acts in the axial direction during rolling, and to prevent center deviation and to be appropriate. It is an object of the present invention to provide a presser roller capable of realizing a sufficient air bleeding and a method for manufacturing a tire component using the presser roller.

The present disclosure takes the following measures to achieve the above object.

The presser roller of the present disclosure is a presser roller that rolls along the circumferential direction while pressing the outer peripheral surface of the tread rubber.
With a shaft that holds both ends,
A tubular elastic body that covers the outer circumference of the shaft and
A plurality of rings supported on the outer peripheral surface of the tubular elastic body and arranged in the axial direction are provided.
The plurality of rings have the same outer diameter and have the same outer diameter.
The hardness of the tubular elastic body decreases from the center in the axial direction to the outside in the axial direction.

In this way, since the outer diameters of the plurality of rings are the same, there is no step on the outer surface of the presser rollers formed on the outer peripheral surfaces of the plurality of rings, and even if a slight axial force acts during rolling. It is possible to properly press the tread rubber without getting caught. Nevertheless, the ring is allowed to be displaced in the radial direction due to the elastic deformation of the tubular elastic body, and the hardness of the tubular elastic body supporting the ring is high and hard in the axial center and decreases toward the lateral side in the axial direction. Since it becomes soft, the pressing force at the center in the axial direction becomes stronger than the pressing force at the outside in the axial direction, and the central portion of the tread rubber can be accurately pressed, and center deviation can be prevented. Further, since a force acts from the central portion of the tread rubber toward the outside, air can be appropriately evacuated.

The presser roller of the present disclosure is a presser roller that rolls along the circumferential direction while pressing the outer peripheral surface of the tread rubber.
With a shaft that holds both ends,
A tubular elastic body that covers the outer circumference of the shaft and
A plurality of rings supported on the outer peripheral surface of the tubular elastic body and arranged in the axial direction are provided.
The plurality of rings have the same outer diameter and have the same outer diameter.
The thickness of the tubular elastic body increases from the center in the axial direction to the outside in the axial direction.

As described above, the thicker the tubular elastic body, the weaker the pressing force, and the thinner the tubular elastic body, the stronger the pressing force. The pressing force at the center in the axial direction becomes stronger than the pressing force at the outside in the axial direction, and the central portion of the tread rubber can be accurately pressed, and center deviation can be prevented. Further, since a force acts from the central portion of the tread rubber toward the outside, air can be appropriately evacuated.

The method for manufacturing the tire component of the present disclosure includes a step of molding the tread rubber and a member to be arranged on the inner peripheral side of the tread rubber, a step of arranging the tread rubber above the member, and the presser foot described above. This includes a step of rolling the tread rubber along the circumferential direction while pressing the outer peripheral surface of the tread rubber with a roller to crimp the tread rubber to the member.

The cross-sectional view which shows the presser roller of 1st Embodiment. The cross-sectional view which shows the presser roller of 1st Embodiment. The cross-sectional view which shows the presser roller of 2nd Embodiment. Explanatory drawing about the trouble of the conventional presser roller.

<First Embodiment>
The presser roller 1 of the first embodiment of the present disclosure will be described with reference to FIGS. 1 and 2. The presser roller 1 rolls along the circumferential direction while pressing the outer peripheral surface of the tread rubber. The axial center 1a of the roller 1 presses the width center of the outer surface of the tread rubber.

FIG. 1 is a cross-sectional view showing a pressing roller 1 in a natural state in which the tread rubber is not pressed. As shown in FIG. 1, the presser roller 1 includes a shaft 2 rotatably held at both ends by a roller traveling device (not shown), a tubular elastic body 3 covering the outer circumference of the shaft 2, and a tubular elastic body. It has a plurality of rings 4 supported by the outer peripheral surface of 3 and arranged in the axial direction AD. Since the ring 4 is fixed to the shaft 2 via the tubular elastic body 3, the ring 4 is allowed to be displaced in the radial direction due to the elastic deformation of the tubular elastic body 3. Each ring 4 is displaced in the radial direction independently of the other rings 4. The plurality of rings 4 are sandwiched by the ring fixing portions 5 from both sides in the axial direction, and the movement in the axial direction AD is restricted.

The plurality of rings 4 have the same outer diameter and inner diameter, and all have the same hardness. In the present embodiment, the ring 4 is made of plastic, but is not limited to this, and may be made of other materials. For example, resin or metal may be used.

The tubular elastic body 3 is formed so that the hardness decreases from the central CL in the axial direction toward the outer OUT in the axial direction. In this embodiment, urethane rubber is used, but other elastic bodies such as rubber, sponge, and resin can be used as long as they can be elastically deformed. In order to appropriately exert the radial displacement of the ring 4, the JISA hardness is preferably in the range of 30 ° to 15 °.

In the present embodiment, as shown in FIG. 2, the tubular elastic body 3 is formed of four rubbers having different hardnesses, and the rubber hardness gradually decreases from the axial center CL to the axial outer OUT. Specifically, as shown in FIG. 2, the JISA hardness is 30 ° in the range of less than 17.5% of the width W of the tread rubber from the axial center CL of the tubular elastic body 3 toward the axial outer OUT. is there. The JISA hardness is 25 ° in the range of 17.5% or more and less than 32.5% of the width W of the tread rubber. The JISA hardness is 20 ° in the range of 32.5% or more and less than 42.5% of the width W of the tread rubber. The JISA hardness is 15 ° in the range of 42.5% or more of the width W of the tread rubber. Within this numerical range, various tread rubber shapes can be supported. This is a preferred range and is not limited to this.

According to the above configuration, the tubular elastic body 3 has a high hardness and is hard, and the tubular elastic body 3 has a low hardness and is soft. Since the thickness of the tubular elastic body 3 is the same, the pressing force due to the elastic repulsive force of the tubular elastic body 3 is stronger in the axial center than in the axial outer side. As a result, the pressing force on the central portion of the tread rubber can be increased as compared with the outer side in the width direction.

In the example shown in FIG. 2, the tubular elastic body 3 has four different hardnesses, and the hardness gradually decreases from the axial center CL toward the axial outer OUT, but is not limited to this. The tubular elastic body 3 may have at least three different hardnesses. When the tubular elastic body 3 has only two different hardnesses, it is difficult to obtain the above effect. For example, the hardness of the tubular elastic body 3 is JISA hardness of 15 ° or more and 30 ° or less, and is reduced by 1 ° for each ring from the axial center CL to the axial outer OUT.

The method for manufacturing the tubular elastic body 3 is to form the tubular elastic body 3 while winding urethane rubber around the shaft 2. When changing the hardness, the rubber to be wrapped may be changed to one having a different hardness.

In order to show the structure and effect of the present disclosure, the following evaluations were performed on the following examples.

(1) Center deviation evaluation A predetermined number of unvulcanized tire components were produced by crimping a tread rubber with a center marker to a belt with a roller. It was confirmed whether the center shift occurred.

Comparative Example 1
As shown in FIG. 1, a presser roller having a plurality of rings having the same outer diameter and inner diameter and having a JISA hardness of 30 ° of the tubular elastic body 3 was produced. Center misalignment evaluation was carried out using this roller.

Example 1
The presser roller shown in FIG. 2 was manufactured. Center misalignment evaluation was carried out using this roller.

Example 2
A holding roller was produced in which the JISA hardness of the tubular elastic body 3'supporting the ring 4'corresponding to the axial center CL was set to 30 °, and each ring was reduced by 1 ° toward the outer OUT in the axial direction. Center misalignment evaluation was carried out using this roller.

As a result of the center deviation evaluation, in Comparative Example 1, the tread rubber which became the center deviation was generated, whereas in Examples 1 and 2, the tread rubber which became the center deviation did not occur. Therefore, it can be understood that the rollers of the present disclosure are superior to the conventional rollers in the effect of preventing center deviation.

As described above, the presser roller of the first embodiment is
A presser roller 1 that rolls along the circumferential direction while pressing the outer peripheral surface of the tread rubber T.
A shaft 2 holding both ends, a tubular elastic body 3 covering the outer circumference of the shaft 2, and a plurality of rings 4 supported by the outer peripheral surface of the tubular elastic body 3 and arranged in the axial direction AD are provided. The outer diameters of the plurality of rings 4 are all the same, and the hardness of the tubular elastic body 3 decreases from the axial center CL toward the axial outer OUT.

As described above, since the outer diameters of the plurality of rings 4 are the same, there is no step on the outer surface of the pressing roller 1 formed on the outer peripheral surfaces of the plurality of rings 4, and a slight force is applied to the axial AD when rolling. Even if it acts, it will not be caught and the tread rubber T can be pressed appropriately. Nevertheless, the ring 4 is allowed to be displaced in the radial direction due to the elastic deformation of the tubular elastic body 3, and the hardness of the tubular elastic body 3 supporting the ring 4 is high and hard in the central CL in the axial direction, and is hard in the axial direction. Since it becomes smaller and softer toward the outer OUT, the pressing force of the axial center CL becomes stronger than the pressing force of the axial outer OUT, and the central portion of the tread rubber T can be accurately pressed, and center deviation can be prevented. Further, since a force acts from the central portion of the tread rubber T toward the outside, air can be appropriately evacuated.

In the first embodiment, the tubular elastic body 3 has at least three different hardnesses, and the hardness gradually decreases from the axial center CL to the axial outer OUT. The above effect is difficult to be exhibited by changing the hardness in two steps. As in this configuration, if the hardness changes in at least three stages, the effect can be exerted.

In the first embodiment, the tubular elastic body 3 has four different hardnesses, and the hardness gradually decreases from the center in the axial direction to the outer side in the axial direction. The more the hardness changes, the easier it is to exert the effect, but changing the hardness is costly. Therefore, it is possible to secure the effect and suppress the cost at the same time.

In the first embodiment, the JISA hardness is 30 °, 17.5% or more 32 in the range of less than 17.5% of the width W of the tread rubber from the axial center CL of the tubular elastic body 3 toward the axial outer OUT. The range of less than 5.5% has a JISA hardness of 25 °, the range of 32.5% or more and less than 42.5% has a JISA hardness of 20 °, and the range of 42.5% or more has a JISA hardness of 15 °. The above configuration is cited as one of the preferred embodiments of the present disclosure.

In the first embodiment, the hardness of the tubular elastic body 3 decreases for each ring 4 from the axial center CL toward the axial outer OUT. According to this configuration, since the hardness is reduced for each ring, a force is easily applied from the central portion of the tread rubber T to the side, which is advantageous for the air bleeding effect.

The method for manufacturing the tire constituent member of the first embodiment includes a step of molding the tread rubber T and a member to be arranged on the inner peripheral side of the tread rubber.
The step of arranging the tread rubber above the member and
The step of rolling along the circumferential direction while pressing the outer peripheral surface of the tread rubber with the pressing roller 1 according to the first embodiment, and crimping the tread rubber to the member is included.

According to this method, since the outer diameters of the plurality of rings 4 are the same, there is no step on the outer surface of the pressing roller 1 formed on the outer peripheral surfaces of the plurality of rings 4, and the axial AD is slightly formed when rolling. Even if a force is applied, the tread rubber T can be appropriately pressed without being caught. Nevertheless, the ring 4 is allowed to be displaced in the radial direction due to the elastic deformation of the tubular elastic body 3, and the hardness of the tubular elastic body 3 supporting the ring 4 is high in the central CL in the axial direction and is hard, and the axial direction is high. Since it becomes smaller and softer toward the outer OUT, the pressing force of the axial center CL becomes stronger than the pressing force of the axial outer OUT, and the central portion of the tread rubber T can be accurately pressed, and center deviation can be prevented. Further, since a force acts from the central portion of the tread rubber T toward the outside, air can be appropriately evacuated.
<Second Embodiment>
Hereinafter, the presser roller according to the second embodiment of the present disclosure will be described with reference to the drawings.

As shown in FIG. 3, the difference between the presser roller 1'of the second embodiment and the presser roller 1 of the first embodiment is the ring 4'and the tubular elastic body 3'. In the second embodiment, the hardness of the tubular elastic body 3'is constant. On the other hand, the thickness of the tubular elastic body 3'increases from the axial center CL toward the axial outer OUT. As the thickness of the tubular elastic body 3'changes, the inner diameter of the ring 4'increases from the axial center CL toward the axial outer OUT. The thickness change of the tubular elastic body 3'may be made for each ring, and may be stepwise with one or a plurality of rings as one step as in the first embodiment.

According to the above configuration, the hardness of the tubular elastic body 3'is constant. Therefore, if the thickness of the tubular elastic body 3'is large, the spring constant is lowered, the pressing force is weakened, and the pressing force of the outer OUT in the axial direction is increased. Is weaker than the axial center CL. On the contrary, if the thickness of the tubular elastic body 3'is thin, the spring constant increases, the pressing force becomes stronger, and the pressing force of the axial center CL becomes stronger than the axial outer OUT. As a result, the pressing force on the central portion of the tread rubber can be increased as compared with the outer side in the width direction.

As described above, the presser roller 1'of the second embodiment is
A presser roller 1'that rolls along the circumferential direction while pressing the outer peripheral surface of the tread rubber T.
A shaft 2 held at both ends, a tubular elastic body 3'covering the outer circumference of the shaft 2, a plurality of rings 4'supported by the outer peripheral surface of the tubular elastic body 3', and arranged in the axial direction AD. The plurality of rings 4'have the same outer diameter, and the thickness of the tubular elastic body 3'increases from the axial center CL toward the axial outer OUT.

As described above, the thicker the tubular elastic body 3', the weaker the pressing force, and the thinner the tubular elastic body 3', the stronger the pressing force. The pressing force of the axial center CL becomes stronger than the pressing force of the axially outer OUT, and the central portion of the tread rubber T can be accurately pressed, and center deviation can be prevented. Further, since a force acts from the central portion of the tread rubber T toward the outside, air can be appropriately evacuated.

The method for manufacturing the tire constituent member of the second embodiment includes a step of molding the tread rubber T and a member to be arranged on the inner peripheral side of the tread rubber.
The step of arranging the tread rubber above the member and
A step of rolling the tread rubber along the circumferential direction while pressing the outer peripheral surface of the tread rubber with the pressing roller 1'described in the second embodiment to crimp the tread rubber to the member.

According to this method, the thicker the tubular elastic body 3', the weaker the pressing force, and the thinner the tubular elastic body 3', the stronger the pressing force. The pressing force of the axial center CL becomes stronger than the pressing force of the axially outer OUT, and the central portion of the tread rubber T can be accurately pressed, and center deviation can be prevented. Further, since a force acts from the central portion of the tread rubber T toward the outside, air can be appropriately evacuated.

It is possible to adopt the structure adopted in each of the above embodiments in any other embodiment.

1, 1'... Presser roller 2 ... Shaft 3, 3'... Cylindrical elastic body 4, 4'... Ring CL ... Axial center OUT ... Axial outside

Claims (2)

A presser roller that rolls along the circumferential direction while pressing the outer peripheral surface of the tread rubber.
With a shaft that holds both ends,
A tubular elastic body that covers the outer circumference of the shaft and
A plurality of rings supported on the outer peripheral surface of the tubular elastic body and arranged in the axial direction are provided.
The plurality of rings have the same outer diameter and have the same outer diameter.
The hardness of the tubular elastic body is constant,
A presser roller in which the thickness of the tubular elastic body increases from the center in the axial direction toward the outside in the axial direction. The process of molding the tread rubber and the members to be placed on the inner peripheral side of the tread rubber,
The step of arranging the tread rubber above the member and
A method for manufacturing a tire component, which comprises a step of rolling along the circumferential direction while pressing the outer peripheral surface of the tread rubber with the pressing roller according to claim 1 to crimp the tread rubber to the member.

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