JP7151399B2 - Method for molding rubber member and pressure roller used therein - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method of molding a rubber member and a pressing roller used therein.

Patent Literature 1 below describes that air in the terminal joint portion is discharged by pressing a pressure roller against the terminal joint portion of an unvulcanized rubber sheet wound around a forming drum.

JP-A-2-175234

However, in Patent Document 1, after a step of a rubber member wound on a drum and a ply material is wound radially outwardly of this step, the air between the step of the rubber member and the ply material is removed. Discharging was not considered.

DISCLOSURE OF THE INVENTION The present invention has been devised in view of the actual situation as described above. The main purpose is to provide rollers.

The present invention provides a joint portion having a step by winding an unvulcanized band-shaped rubber member on a drum and overlapping the end of the winding of the rubber member on the radially outer side of the rubber member wound on the drum. winding a ply material containing cords around the joint portion in the radial direction; rolling a pressure roller on the ply material from one end side to the other end side in the axial direction of the drum, and pressing the ply material against the step.

In the method of molding a rubber member according to the present invention, the pressing roller includes a support shaft and a roller supported by the support shaft and elastically deformable in a radial direction of the support shaft, and the roller is attached to the support shaft. A first roller group consisting of a plurality of first roller pieces arranged on both outer sides in the axial direction, and a first roller group between the first roller group. and a second roller group comprising a plurality of second roller pieces, wherein the width of each of the second roller pieces is preferably smaller than the width of each of the first roller pieces.

In the rubber member molding method according to the present invention, it is desirable that the width of each of the second roller pieces is 2 to 3 mm.

In the rubber member molding method according to the present invention, it is preferable that the width of each first roller piece is 1.5 times or more the width of each second roller piece.

In the rubber member molding method according to the present invention, it is preferable that the axial length of the second roller group is 40% to 50% of the axial length of the rollers.

The present invention is a pressure roller including a support shaft and a roller supported by the support shaft and elastically deformable in a radial direction of the support shaft, wherein the rollers are divided in the axial direction of the support shaft. The plurality of roller pieces are arranged between a first roller group made up of a plurality of first roller pieces arranged on both outer sides in the axial direction and the first roller group, and and a second roller group comprising a plurality of second roller pieces, wherein the width of each second roller piece is smaller than the width of each first roller piece.

The rubber member molding method of the present invention includes the steps of forming a joint portion having a step while winding an unvulcanized belt-shaped rubber member on a drum, and winding a ply material radially outward of the joint portion. and pressing the ply material against the step. The step is formed by overlapping the winding end of the rubber member on the radially outer side of the rubber member wound on the drum. In the pressing step, the pressing roller rolls on the ply material from one end side to the other end side in the axial direction of the drum.

In such a pressing step, the gap formed between the step of the rubber member and the ply material is crushed, and the air in the gap is pushed from one end side to the other end side of the drum in the axial direction of the drum. is discharged smoothly.

It is a perspective view of an example of an apparatus used in the rubber member molding method of the present embodiment. FIG. 4 is a cross-sectional view of the drum for explaining a forming process and a winding process; FIG. 5 is a cross-sectional view of the drum for explaining the pressing process; (a) is a cross-sectional view of the pressing roller of the present embodiment, and (b) is an exploded perspective view of the pressing roller of (a). (a) is a cross-sectional view of a pressure roller of another embodiment, and (b) is a side view of a roller piece 14 of the pressure roller 3 of (a). FIG. 11 is a cross-sectional view of a pressure roller of still another embodiment;

An embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a perspective view showing an example of an apparatus 1 for carrying out the rubber member molding method of this embodiment. Apparatus 1 includes, for example, a drum 2 and a pressure roller 3, as shown in FIG. In the rubber member molding method, for example, a rubber member G for a tire can be molded. The rubber member molding method includes a forming step S1, a winding step S2, and a pressing step S3 in this embodiment.

FIG. 2 is a cross-sectional view of the drum 2 for explaining the forming step S1 and the winding step S2. As shown in FIG. 2, in the forming step S1 of the present embodiment, an unvulcanized band-shaped rubber member G is wound around the drum 2, and the winding end Ge of the rubber member G is wound around the drum 2. A joint portion F having a step F1 is formed by overlapping the rubber member G on the radially outer side thereof.

A width Wa of the joint portion F is not particularly limited, but is, for example, about 10 to 30 mm. Moreover, the step F1 corresponds to the thickness t of the rubber member G, for example.

As shown in FIG. 1, the drum 2 of this embodiment employs a well-known structure having an outer peripheral surface 2a around which a rubber member G is wound. The drum 2 includes, for example, a plurality of segments 4 arranged in the circumferential direction, expanding/contracting means (not shown) for moving each segment 4 radially inward and outward, and a rotating shaft 5 fixing the expanding/contracting means. In this embodiment, the outer peripheral surface 2a of the drum 2 is formed by connecting the outer surfaces of the segments 4 in the circumferential direction. The rotary shaft 5 is rotatably supported by, for example, a base 6 provided on one side thereof. The drum axis direction of the drum 2 is arranged horizontally, for example.

The rubber member G is supplied onto the outer peripheral surface 2a of the drum 2 using, for example, a conveying device T having a well-known structure. The joining portion F may be formed, for example, by a sticking means (not shown) or manually by an operator. In this embodiment, the joint F is formed along the axial direction of the drum from one end to the other end in the width direction of the rubber member G. As shown in FIG.

In this embodiment, the rubber member G employs a well-known air-impermeable inner liner (not shown) that forms the inner cavity surface of the tire. The rubber member G is not limited to these, and may be, for example, a well-known clinch rubber (not shown) disposed on the bead portion of a tire, or a well-known chafer for preventing rim slippage.

As shown in FIG. 2, in the winding step S2 of the present embodiment, the ply material P is wound radially outward of the joint F. As shown in FIG. As a result, a gap S is formed between the step F1 of the joint F and the ply material P, thereby trapping air. In the winding step S2, for example, the ply material P is wound such that the winding start end and the winding end (not shown) of the ply material P are not disposed radially outside the joint F. Winding of the ply material P is performed in the same manner as the rubber member G, for example.

As shown in FIG. 1, the ply material P has, for example, a width W2 larger than the width W1 of the rubber member G in the axial direction of the drum. Such a ply material P tends to trap air between the joint F and the ply material P. Note that the ply material P is not limited to such a mode, and may have a width W2 that is smaller than the width W1 of the rubber member G.

As the ply material P, in this embodiment, a well-known carcass ply in which a carcass cord is covered with a topping rubber is adopted. The ply material P is not limited to these, and may be, for example, a well-known reinforcing ply for reinforcing the bead portion.

FIG. 3 is an enlarged sectional view of the rubber member G in the pressing step S3. As shown in FIG. 3, in the pressing step S3 of the present embodiment, the pressing roller 3 rolls on the ply material P from one end side to the other end side in the axial direction of the drum, and the ply material P is moved to the step F1. impose. As a result, the gap S is crushed, and the air in the gap S is smoothly discharged from one end side of the drum 2 in the axial direction to the other end side.

As shown in FIG. 1, the pressure roller 3 is movably held by a moving means 8, for example. The moving means 8 is supported by, for example, a first moving member 9 that reciprocates the pressing roller 3 in the axial direction of the drum, and a first moving member 9 that moves the pressing roller 3 in the radial direction of the drum 2 . 2 mobile device 10;

The first moving member 9 includes, for example, a guide rail 9a extending in the axial direction of the drum, a base portion 9b guided by the guide rail 9a, and a ball (not shown) having a well-known structure capable of moving the base portion 9b along the guide rail 9a. and a screw mechanism. The first moving tool 9 may include a known rack-and-pinion mechanism instead of the ball screw mechanism.

The second mover 10 is preferably, for example, an air cylinder having a well-known structure. The second moving tool 10 is supported by, for example, the base 9b so as to be movable integrally therewith. In this embodiment, the second moving member 10 includes a rod 10a extending and contracting in the radial direction of the drum 2 and a roller holder 10b held at the tip of the rod 10a. The pressing roller 3 is supported by a roller holder 10b. In addition, the moving means 8 is not limited to such a mode, and can take various modes. Further, the pressing roller 3 is not limited to being pressed by the moving means 8, and may be manually pressed by an operator.

FIG. 4(a) is a cross-sectional view of the pressure roller 3 of this embodiment. FIG. 4(b) is an exploded perspective view of the pressing roller 3. FIG. As shown in FIGS. 4A and 4B, the pressure roller 3 of this embodiment includes a support shaft 12 and a roller supported by the support shaft 12 and elastically deformable in the radial direction of the support shaft 12. 13. In this embodiment, the support shaft 12 has a cylindrical shape and is supported perpendicularly to the axial direction of the drum by the roller holder 10b.

The roller 13 of this embodiment includes a plurality of roller pieces 14 divided in the axial direction of the support shaft 12 .

Each roller piece 14 of this embodiment is formed in a thin ring shape. The roller piece 14 has, for example, an outer circumferential surface 14s extending in the circumferential direction. 14 s of outer peripheral surfaces of the roller pieces 14 are in contact with the ply material P to apply a pressing force to the ply material P in this embodiment.

In the present embodiment, each roller piece 14 is arranged between a pair of first roller groups 15A made up of a plurality of first roller pieces 15 arranged on both outer sides in the axial direction, and the first roller groups 15A, 15A, and , and a second roller group 16</b>A consisting of a plurality of second roller pieces 16 . The width (width of the outer peripheral surface) w2 of the second roller piece 16 is formed smaller than the width (width of the outer peripheral surface) w1 of the first roller piece 15 . As a result, as shown in FIG. 3, the gap S can be smoothly crushed by the second roller piece 16, so that the air in the gap S is effectively discharged.

The width w2 of each second roller piece 16 is preferably 2-3 mm. If the width w2 of the second roller piece 16 is less than 2 mm, the durability of the second roller piece 16 may deteriorate. If the width w2 of the second roller piece 16 exceeds 3 mm, the gap S may not be effectively crushed.

The width w1 of each first roller piece 15 is preferably 1.5 times or more the width w2 of each second roller piece 16. As shown in FIG. The first roller piece 15 presses the radially outer side of the ply material P except for the gap S in this embodiment. Therefore, by setting the width w1 of the first roller piece 15 to be 1.5 times or more the width w2 of the second roller piece 16, the ply material P can be uniformly pressed against the rubber member G. Although not particularly limited, the width w1 of the first roller piece 15 is preferably 2.5 times or less the width w2 of the second roller piece 16.

The axial length Lb of the second roller group 16A is preferably 40% to 50% of the axial length La of the rollers 13A. If the axial length Lb of the second roller group 16A is less than 40% of the axial length La of the rollers 13, the second roller group 16A may not be arranged radially outside the gap S. When the axial length Lb of the second roller group 16A exceeds 50% of the axial length La of the rollers 13, the radially outer side of the ply material P excluding the gap S is covered by many second roller pieces 16. As a result, the pressing of the rubber member G may become uneven.

In order to effectively exhibit the above action, the axial length La of the roller 13 is preferably in the range of 15 to 100 mm.

The roller pieces 14 are made of, for example, various metal materials and plastic materials. However, the roller pieces 14 are preferably made of nylon resin in order to suppress friction between the side surfaces of the adjacent roller pieces 14, to smoothly move the roller pieces 14 in the radial direction, and to reduce wear between the roller pieces 14. .

The pressing roller 3 of the present embodiment further includes a bearing member 18 mounted on the support shaft 12, an elastically deformable roll portion 19 mounted on the bearing member 18, and a pair of side plates 20 for retaining the roller piece 14. and

The bearing member 18 is formed of, for example, a cylindrical base 21 that extends continuously over substantially the entire length of the pressing roller 3 . In this embodiment, the base body 21 has a bearing surface formed of a low-friction bearing material on its inner peripheral surface.

The roll portion 19 is, for example, an elastically deformable cylindrical body that extends continuously over substantially the entire length of the pressure roller 3 . In this embodiment, the roll part 19 is fixed to the base 21 so as to be able to rotate integrally therewith. Further, the roller piece 14 is externally inserted on the radially outer side of the roll portion 19 of the present embodiment. Thereby, the roller pieces 14 can be individually moved radially by the elastic deformation of the roll portion 19 .

The roll portion 19 is made of various rubber-like elastic materials such as natural rubber, chloroprene rubber, urethane rubber, and silicone rubber. However, the roll portion 19 is preferably made of urethane rubber in terms of elasticity, mechanical strength, ease of moldability, and the like. As the rubber-like elastic material for the roll portion 19, one having a 100% modulus of 7 to 10 can be preferably used.

The side plate 20 of this embodiment has a ring shape and is fixed to the base 21 on both axial sides of the roll portion 19 . The side plate 20 prevents the roller piece 14 from slipping off and restrains the roller piece 14 from moving in the axial direction of the support shaft 12 and from tilting with respect to the axial direction.

As shown in FIG. 3, such a pressing roller 3 can roll along the joint F while radially displacing the second roller pieces 16 in accordance with the step F1 of the joint F. can. Since the roller piece 14 is hard and the roller piece 14 itself is not deformed, the joining portion F can be firmly pressed in line with the step F1, so that the air in the gap S is smoothly discharged from the other end side. can do.

FIG. 5(a) is a cross-sectional view of the pressure roller 3 of another embodiment, and FIG. 5(b) is a side view of the roller piece 14 of the pressure roller 3 of FIG. 5(a). The same components as those of the pressure roller 3 of this embodiment shown in FIGS. 1 to 4 are given the same reference numerals, and the description thereof is omitted. As shown in FIGS. 5A and 5B, the pressure roller 3 of this embodiment includes a support shaft 12 and a plurality of rollers supported by the support shaft 12 and elastically deformable in the radial direction of the support shaft 12 . roller strips 14.

The support shaft 12 rotatably supports the roller piece 14 via the rotary cylinder 30 . Side plates 20 are arranged on both sides of the rotating cylinder 30 in the axial direction. The rotary cylinder 30 is concentrically arranged radially outward of the support shaft 12 via a bearing 31 . The rotating barrel 30 of this embodiment can rotate independently of the support shaft 12 .

The roller piece 14 of this embodiment includes a ring-shaped inner ring 32 externally fitted on the rotary cylinder 30, an outer ring 33 separated from the inner ring 32 radially outwardly of the support shaft 12, and a ring between the inner ring 32 and the outer ring 33. A connecting portion 34 is provided for elastic connection.

The outer ring 33 is, for example, ring-shaped and has an inner diameter larger than the outer diameter of the inner ring 32 . The outer ring 33 is arranged concentrically with the inner ring 32, for example.

The connecting portion 34 of this embodiment is formed to spirally extend from the outer peripheral surface 32 o of the inner ring 32 to the inner peripheral surface 33 i of the outer ring 33 . As a result, a gap 35 is provided between the outer ring 33 and the inner ring 32 in which the connecting portion 34 is not provided. Such a connecting portion 34 can elastically deform the outer ring 33 in the radial direction of the support shaft 12 through the gap 35 .

FIG. 6 is a cross-sectional view of the pressing roller 3 of still another embodiment. The same components as those of the pressure roller 3 of the embodiment shown in FIGS. 1 to 5 are denoted by the same reference numerals, and descriptions thereof are omitted. As shown in FIG. 6, the pressure roller 3 of this embodiment includes a support shaft 12 and a metal roller which is arranged radially outwardly of the support shaft 12 and is rotatably supported around the support shaft 12. It has a well-known structure including a core material 38 and a rubber layer 39 arranged radially outwardly of the core material 38 . Even with such a pressing roller 3, air can be smoothly discharged by using the forming method of the present embodiment.

Although the particularly preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the illustrated embodiments and can be modified in various ways.

In order to confirm the effects of the present invention, 30,000 tires were manufactured using rubber members formed by the apparatus shown in FIG. , the defective product rate was calculated. The rubber member is formed by winding the inner liner and the carcass ply on the drum, pressing the stepped portion of the inner liner from the outer surface of the carcass ply with a pressing roller, and discharging the air between the stepped portion and the carcass ply. formed. All the specifications other than those listed in Table 1 are the same.

<Defective product rate>
After vulcanization molding of the tire, uneven deformation due to residual air between the step and the carcass ply was visually confirmed by a tester. The evaluation is indicated by the ratio of the number of tires with uneven deformation, and the smaller the number, the better. In addition, "A" in Table 1 means that the pressure roller is moved spirally in the circumferential direction of the drum, and "B" means that the pressure roller is moved from one side to the other side in the axial direction of the drum. means that
Width w1 of the first roller piece: 5.0 mm (Examples 1 and 2)
Width w2 of the second roller piece: 2.5 mm (Examples 1 and 2)
Results are shown in Table 1.

As a result of the test, it can be confirmed that the molding method of the example has a lower failure rate than the molding method of the comparative example.

2 drum 3 pressure roller F joint F1 step G rubber member Ge end of rubber member P ply material

Claims (4)

A step of winding an unvulcanized band-shaped rubber member on a drum, and overlapping the winding end of the rubber member on the radially outer side of the rubber member wound on the drum to form a joint having a step. When,
winding a ply material containing cords radially outwardly of the joint;
rolling a pressing roller on the ply material from one end side to the other end side in the axial direction of the drum to press the ply material against the step ;
The pressing roller includes a support shaft and a roller supported by the support shaft and elastically deformable in a radial direction of the support shaft,
The roller is composed of a plurality of roller pieces divided in the axial direction of the support shaft,
The plurality of roller pieces include a first roller group composed of a plurality of first roller pieces arranged on both outer sides in the axial direction, and a plurality of second roller pieces arranged between the first roller groups. and a second roller group,
The width of each of the second roller pieces is smaller than the width of each of the first roller pieces,
The pressing step is a step of positioning each of the second roller pieces radially outward of the winding end of the rubber member.
Rubber member molding method. 2. The method of molding a rubber member according to claim 1 , wherein each of said second roller pieces has a width of 2 to 3 mm . 3. The rubber member molding method according to claim 1, wherein the width of each of the first roller pieces is 1.5 times or more the width of each of the second roller pieces . 4. The method of molding a rubber member according to claim 1, wherein the length of said second roller group in said axial direction is 40% to 50% of the length of said roller in said axial direction .

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