JP2017209807A - Bead clamp ring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bead clamp ring in which slide between itself and a bead part is improved and installation of the bead part is easily performed with a good accuracy.SOLUTION: A bead clamp ring comprises a ring body 4 including: a cylindrical seating part 5 on which a bead part T1 seats; a first guide part 6 which has a cone shape which is inclined to a direction in which a diameter thereof is reduced toward an axial direction outer side from the seating part 5, and which has a first slide surface 6S which guides the bead part T1 to the seating part 5 while sliding the bead part from the axial direction outer side; a positioning part 8 which rises to a radial direction outer side from the seating part 5; and a second guide part 7 which has a cone shape which is inclined to a direction in which a diameter thereof is reduced toward an axial direction inner side from a radial direction outer end of the positioning part 8, and which has a second slide surface 7S which guides the bead part T1 to the seating part 5 side while sliding the bead part from the axial direction inner side. The ring body 4 is formed from a fiber-reinforced plastic. An air discharge port 25 for reducing a slip resistance of the bead part T1 is opened to one of the first and second slide surfaces 6S, 7S.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a bead clamp ring that facilitates mounting of a bead portion.

In the production of radial tires,
(A) a green tire substrate forming step of forming a cylindrical green tire substrate including a carcass ply using a molding former;
(B) A shaping step of inflating (shaping) the raw tire base body in a toroidal shape using a shaping former, thereby integrally joining the raw tire base body and the tread ring waiting on the outside in the radial direction; Is done.

  And when manufacturing a small and lightweight tire with a small bead rigidity, such as a motorcycle tire, the shaping former a has a simple bead clamp ring b having no expansion / contraction function, as shown in FIG. b is arranged (see, for example, Patent Document 1).

  This type of bead clamp ring b includes a seating portion b1 on which a bead portion T1 of the raw tire base T is seated, and a cone-shaped guide portion b2 that is inclined in a direction of decreasing in diameter toward the outside in the axial direction from the seating portion b1. And a positioning part b3 that rises radially outward from the axially inner end of the seating part b1.

  And the raw tire base | substrate T is thrown in from the free end side of the spindle c in the shaping former a. At this time, the raw tire base T can straddle between the bead clamp rings b and b because the bead part T1 on the front side in the loading direction f gets over the positioning part b3 of the two bead clamp rings b. Thereafter, the bead clamp rings b and b move in directions away from each other, whereby each bead portion T1 is guided by the seat portion b1 while sliding on the guide portion b2.

  However, the bead clamp ring b is conventionally formed of a metal material such as steel or aluminum alloy. Therefore, the bead part T1 covered with the unvulcanized rubber is easy to adhere and adhere to the surface of the guide part b2, and slips poorly. For this reason, the bead portion T1 is not properly held at the seating position, and the tire forming accuracy tends to be impaired. In order to improve sliding, it is proposed to apply a lubricant to the guide portion b2. In this case, the workability is reduced by the application, and the lubricant adhering to the green tire base T peels off the rubber. Inducing the risk of reducing tire quality.

  In recent years, the bead clamp ring b is inclined so as to reduce the diameter from the radially outer end of the positioning portion b3 toward the inner side in the axial direction in order to smoothly get over the positioning portion b3 by the bead portion T1. Providing a cone-shaped second guide portion b4 (indicated by a one-dot chain line) has been proposed. However, for the second guide portion b4, the improvement of the slip is indispensable in order to smoothly get over the second guide portion b4.

JP 2010-089316 A

  Therefore, the invention can improve the slip with the bead part without using a lubricant, and can easily and accurately attach the bead part without deteriorating workability and tire quality. It is an object to provide a clamp ring.

The present invention is a bead clamp ring for holding a bead portion of a raw tire,
A cylindrical seating portion for seating and holding the bead portion;
A first cone having a cone shape that is inclined in a direction of reducing the diameter from the seating portion toward the outer side in the axial direction and having a first sliding surface that guides the seat portion from the outer side in the axial direction while sliding the bead portion. Guide,
A positioning portion that rises in a step shape radially outward from the axially inner end of the seating portion;
A second sliding surface that has a cone shape that is inclined in a direction of decreasing in diameter toward the inner side in the axial direction from the radially outer end of the positioning part, and that guides to the seating part side while sliding the bead part from the inner side in the axial direction. A ring body including a second guide having
The ring body is formed of fiber reinforced plastic;
In addition, an air discharge port that discharges compressed air to reduce the slip resistance of the bead portion is opened on at least one of the first sliding surface and the second sliding surface.

  In the bead clamp ring according to the present invention, it is preferable that the fiber reinforced plastic is composed of a prepreg laminate.

  In the bead clamp ring according to the present invention, the prepreg preferably includes a woven member woven with warps and wefts.

  In the bead clamp ring according to the present invention, each layer of the laminate is composed of a plurality of prepreg divided pieces divided in the circumferential direction, and each layer is formed by connecting between the circumferential edge portions of the prepreg divided pieces. Preferably it is formed.

  In the bead clamp ring according to the present invention, it is preferable that the laminated body includes layers having mutually different circumferential phases of connection positions of the prepreg divided pieces between adjacent layers.

In the bead clamp ring according to the present invention, the prepreg divided piece includes a first prepreg in which one of the warp or the weft is arranged at an angle α1 of 40 to 50 degrees with respect to a circumferential width center line of the prepreg divided piece. It is composed of divided pieces and second prepreg divided pieces arranged at an angle α2 of ± 5 degrees,
The laminate is preferably laminated by combining a first layer made of a first prepreg divided piece and a second layer made of a second prepreg divided piece.

  As described above, the present invention provides a ring body having a first guide portion for guiding the bead portion from the axially outer side to the seating portion side, and a second guide portion for guiding the bead portion from the axially inner side to the seating portion side. Are made of fiber reinforced plastic.

  Therefore, rough irregularities are formed on the sliding surfaces of the first and second guide portions by the fibers contained in the fiber-reinforced plastic. As a result, it is possible to suppress the bottom surface (unvulcanized rubber) of the bead portion from coming into close contact. Further, since the sliding surface is covered with the plastic material, it is possible to suppress the bottom surface (unvulcanized rubber) of the bead portion from sticking. And the slip with a bead part can be improved according to these synergistic effects.

  Moreover, an air discharge port is opened on at least one of the sliding surface of the first guide portion or the sliding surface of the second guide portion. Therefore, an air layer can be formed between the bead portion and the sliding surface by the compressed air from the air discharge port, and the sliding resistance of the bead portion can be further reduced.

  As a result, the bead portion can be easily and accurately mounted. Further, since it is not necessary to apply the lubricant, it is possible to suppress the deterioration of workability due to the application and the deterioration of the tire quality due to the lubricant adhering to the raw tire substrate.

It is sectional drawing which shows the use condition of the bead clamp ring of this invention. It is a perspective view which shows the said bead clamp ring. It is a fragmentary sectional view of the bead clamp ring which expands and shows an air discharge port. It is a fragmentary perspective view which exaggerates and shows the exhaust ring which forms an air discharge outlet. It is a schematic sectional view of the thickness direction of the bead clamp ring. It is a side view which represents each layer of a laminated body on behalf of the layer distribute | arranged to the most sliding surface side. (A) is a conceptual diagram which shows the 1st layer which consists of a 1st prepreg division piece, (B) is the 2nd layer which consists of a 2nd prepreg division piece. (A)-(E) are the conceptual diagrams which show the phase of the butt position of the prepreg division piece in each layer of a laminated body. It is sectional drawing which illustrates the formation method of a ring main body. It is sectional drawing which illustrates the formation method of an air discharge outlet. It is a conceptual diagram explaining the problem of the conventional bead clamp ring.

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 shows a bead clamp ring 1 of this embodiment provided in a shaping former 2 for receiving and holding a bead portion T1 of a cylindrical green tire base T formed by a molding former (not shown). used. Although the shaping former 2 is provided with a pair of bead clamp rings 1, only the bead clamp ring 1 on one side is shown in the figure.

  The bead clamp ring 1 is attached to a sliding body 3 that can move in the axial direction, and the held bead portions T1 are moved toward each other. In addition, the raw tire base T is inflated (shaped) between the bead portions T1 and T1 in synchronization with the movement, and thereby the raw tire base T and a tread ring (not shown) that is kept on the outside in the radial direction. ) Are joined together. That is, a shaping process is performed.

  Next, as shown in FIGS. 1 and 2, the bead clamp ring 1 includes a ring body 4 including a seating portion 5, a first guide portion 6, a second guide portion 7, and a positioning portion 8. Yeah. The ring main body 4 of this example includes the seat portion 5, the first and second guide portions 6 and 7, the positioning portion 8, the side wall portion 9, and the attachment portion 10.

  The seat portion 5 has a cylindrical shape, and the bottom surface Ts of the bead portion T1 is seated and held on the outer peripheral surface thereof.

  The first guide portion 6 has a cone shape that is inclined in a direction of reducing the diameter from the outer end in the axial direction of the seat portion 5 toward the outer side in the axial direction. The outer peripheral surface of the first guide portion 6 constitutes a cone-shaped first sliding surface 6S that guides the bead portion T1 from the outside in the axial center direction to the seating portion 5 side while sliding the bottom surface Ts. The “axial direction” means the direction of the axial center i of the bead clamp ring 1. Among these, the direction in which the pair of bead clamp rings 1 and 1 face each other is defined as “inside” in the axial direction, and the opposite is defined as “outside”.

  The positioning portion 8 rises in a step shape from the inner end in the axial direction of the seating portion 5 to the outer side in the radial direction. The positioning portion 8 positions the bead portion T1 in the axial direction by contacting the inner surface of the bead portion T1.

  The second guide portion 7 has a cone shape that is inclined in a direction of reducing the diameter from the radially outer end of the positioning portion 8 toward the inner side in the axial center direction. The outer peripheral surface of the second guide portion 7 constitutes a cone-shaped second sliding surface 7S that guides the bead portion T1 from the inner side in the axial center direction to the seating portion 5 side while sliding the bottom surface Ts. The second guide portion 7 is used when the raw tire base T is straddled between the bead clamp rings 1 and 1 when the raw tire base T is introduced. That is, the second sliding surface 7S guides the bead portion T1 on the front side in the making direction, and gets over the positioning portion 8 from the inner side in the axial direction. In contrast, the first sliding surface 6S guides and seats the bead portion T1 after the raw tire base T straddles between the bead clamp rings 1 and 1 from the outside in the axial center direction to the seating portion 5.

  The side wall portion 9 extends radially inward from the second guide portion 7. The mounting portion 10 has a cylindrical shape, for example, and is continuous with the radially inner end of the side wall portion 9. The mounting portion 10 is fixed to the sliding body 3 and connects the ring body 4 to the sliding body 3 so as to be integrally movable. In the figure, reference numeral 12 denotes a key, and 13 denotes a keyway.

  An air discharge port 25 is formed in at least one of the first sliding surface 6S and the second sliding surface 7S to discharge compressed air and reduce the sliding resistance of the bead portion T1. In this example, a case where a plurality of air discharge ports 25 are arranged on the second sliding surface 7S at intervals in the circumferential direction is shown.

  The air discharge port 25 is formed by an exhaust unit 26 as shown in FIGS. In this example, the exhaust unit 26 includes an exhaust ring 27 embedded in the second guide portion 7 and a plurality of pipes 28 connected to the exhaust ring 27.

  The exhaust ring 27 is, for example, an annular body having a square cross section, and the outer peripheral surface 27S constitutes a part of the second sliding surface 7S. That is, the outer peripheral surface 27S is flush with the remaining portion of the second sliding surface 7S and forms the same surface.

  The exhaust ring 27 is formed with a plurality of air holes 29 penetrating inward and outward in the radial direction. The radially outer end of the air hole 29 constitutes the air discharge port 25. Further, the radially inner end of the air hole 29 constitutes a mounting hole 29a for pipe mounting.

  The radially outer end of the pipe 28 is integrally fixed to the mounting hole 29 a by press-fitting, bonding, welding, or the like, and the center hole of the pipe 28 and the air hole 29 communicate with each other. The pipe 28 penetrates through the second guide portion 7, and its radially inner end portion 28 a is exposed from the second guide portion 7. And the other end part of the pipe | tube 30 which one end conduct | electrically_connects to compressed air supply sources (not shown), such as a compressor, for example is connected to this exposed part. As the pipe 30 and its connection means, various known ones can be adopted.

  Here, when the bead portion T1 slides on the second sliding surface 7S, the compressed air from the air discharge port 25 forms an air layer between the bead portion T1 and the second sliding surface 7S. Thereby, the slip resistance of bead part T1 can be reduced.

  In the present invention, the ring body 4 is made of fiber reinforced plastic. As a result, fine rough irregularities are formed on the first and second sliding surfaces 6S and 7S by the fibers contained in the fiber-reinforced plastic. As a result, it is possible to further prevent the bottom surface Ts of the bead portion T1 from coming into close contact. In addition, since the first and second sliding surfaces 6S and 7S are covered with the plastic material, it is possible to prevent the bottom surface Ts of the bead portion T1 from sticking. These synergistic effects can improve slippage with the bottom surface Ts of the bead portion T1, and the raw tire base T can be inserted and the bead portion T1 can be easily and accurately seated. In addition, since it is not necessary to apply the lubricant, it is possible to suppress the deterioration of workability due to the application and the deterioration of the tire quality due to the adhesion of the lubricant to the raw tire base T.

As shown in FIG. 5, in this example, the ring body 4 is formed from a prepreg laminate 11. In this example, the case where the laminated body 11 is comprised by 10 layers is shown. When distinguishing each layer P, the layer most arranged on the sliding surfaces 6S and 7S side is the first layer P ₁ , and the layers sequentially arranged on the outer side are the second layer P ₂ to the tenth layer P _10. Call it.

  The prepreg is a sheet-like composite material made of a fibrous reinforcing material such as carbon fiber or aramid fiber and a thermosetting resin such as an epoxy resin, and the layers P made of the prepreg are integrated with each other by heating pressure. Combined. In this example, a plain woven fabric member woven with warps 15a and wefts 15b is used as the fibrous reinforcing material. Carbon fibers are used as the fibers of the warp 15a and the weft 15b.

FIG. 6 shows a side view of the _first layer P1 as viewed from the outside in the axial direction. As represented by the _first layer P1, each layer P of the laminate 11 is composed of a plurality of prepreg divided pieces D divided in the circumferential direction, and between the circumferential edge portions De of the prepreg divided pieces D. Each layer P is formed by connecting. In addition, as the “connection”, an overlap joint that connects adjacent circumferential end edges De with each other and a butt joint that connects adjacent circumferential end edges De with each other can be adopted. An overlap joint can be preferably used. Moreover, in this example, the case where each layer P is formed from six prepreg divided pieces D that are equally divided is shown. In the figure, in order to clarify each prepreg division piece D, the prepreg division pieces D are illustrated in different shades.

  As conceptually shown in FIGS. 7A and 7B, the prepreg segment D of this example is composed of first and second prepreg segments D1 and D2 in which the orientation of the yarn 15 is different. In the first prepreg segment D1, one of the warp 15a or the weft 15b is arranged at an angle α1 of 40 to 50 degrees with respect to the circumferential width center line X of the prepreg segment D. In the second prepreg segment D2, one of the warp 15a or the weft 15b is arranged at an angle α2 of ± 5 degrees with respect to the circumferential width center line X of the prepreg segment D.

  Each layer P of the laminate 11 includes a first layer 16 made of the first prepreg divided piece D1 or a second layer 17 made of the second prepreg divided piece D2. In the stacked body 11, the first layer 16 and the second layer 17 are combined and stacked. As a result, at least one, ie, six locations in the present example, are formed between the first layer 16 and the second layer 17 adjacent to each other. The number na between the adjacent layers of the first layer 16 and the second layer 17 is preferably 50% or more, more preferably 60% or more of the number n between all the layers.

  Thus, by forming the ring body 4 from the prepreg laminate 11 having carbon fibers, it is possible to ensure strength and rigidity equal to or higher than those of metal while reducing the weight. . Further, by configuring each layer P with a plurality of prepreg divided pieces D divided in the circumferential direction, the ring body 4 having a complicated shape can be accurately formed while suppressing wrinkles and distortion. In particular, in the laminate 11, the first layer 16 composed of the first prepreg segment D1 (yarn orientation angle α1 is 40 to 50 degrees) and the second prepreg segment D2 (yarn orientation angle α2 is ± 5). In the case where the second layer 17 composed of the second degree 17 is laminated in combination, the strength and rigidity of the ring body 4 can be increased uniformly in all directions.

In the present embodiment, the sliding surface 6S, the 1-th layer _{P 1} forming a 7S, are formed in the first layer 16 (orientation angle α1 is 40 to 50 degrees of the yarn). Thereby, the resistance when the bead portion T <b> 1 slides can be reduced as compared with the case where the second layer 17 is formed.

  Further, as shown in FIG. 6, in each layer P, the fibers are interrupted at the connection position Q of the prepreg segment D, so that the strength and rigidity are locally reduced. Therefore, in this example, as shown in FIG. 8, at least one or more layers having mutually different circumferential phases of the connection positions Q of the prepreg divided pieces D are provided between adjacent layers.

Specifically, FIG. 8 (A) shows a part of the arrangement of prepreg divided piece D in the first layer P ₁ as a reference. FIG. 8 (B) shows a part of the arrangement of prepreg split pieces D in the second layer P _2, with respect to prepreg divided piece D standards, circumferential at an angle βa phase connection position Q is, for example, 4 degrees The direction is different on one side. FIG. 8C shows a part of the arrangement of the prepreg segment D in the _third and fourth layers P ₃ and P ₄ , and the phase of the connection position Q is, for example, 8 with respect to the reference prepreg segment D. The angle βb is different to one side in the circumferential direction. FIG. 8D shows a part of the arrangement of the prepreg divided pieces D in the _{fifth to seventh} layers P _{5 to} P ₇ , and the phase of the connection position Q is 16 with respect to the reference prepreg divided piece D, for example. The angle βc is different to one side in the circumferential direction. FIG. 8E shows a part of the arrangement of the prepreg divided pieces D in the _eighth to tenth layers P _{8 to} P _10. The phase of the connection position Q is, for example, 20 with respect to the reference prepreg divided piece D. The angle βd is different to one side in the circumferential direction.

Therefore, in this example, between the first and second layers P ₁ , P _2, between the second and third layers P ₂ , P _3, between the fourth and fifth layers P ₄ , P ₅ , and 7 The phase in the circumferential direction of the connection position Q is different between the eighth and eighth layers P ₇ and P ₈ . Thereby, the connection positions Q are dispersed in the circumferential direction. The phase angle β from the reference is βa <βb <βc <βd. The maximum phase angle β (βd in this example) is smaller than the center angle θ of the prepreg segment D.

  Next, as shown in FIG. 9, the ring body 4 is formed by sequentially sticking and stacking raw prepreg divided pieces D on the cavity surface 20 </ b> S of the mold 20, and then thermally curing by heating and pressing with an autoclave. Formed with. The molding die 20 of this example includes, for example, mold parts 20U and 20L that can be divided vertically at the position of the positioning part 8, and the ring main body 4 after formation is removed by dividing the mold parts 20U and 20L. Yes.

  For the formation of the air discharge port 25, as shown in FIG. 10, an annular exhaust unit 26 in which a plurality of pipes 28 are connected to an exhaust ring 27 is prepared in advance, and the exhaust unit 26 is arranged on the cavity surface 20S. To do. At this time, the outer peripheral surface 27S of the exhaust ring 27 and the sliding surface 7S molding surface portion 20Sa on the cavity surface 20S form the same inclined cone surface. Accordingly, the exhaust unit 26 can be disposed without being displaced on the cavity surface 20S. The exhaust ring 27 is made of a metal material, preferably a light metal material such as an aluminum alloy.

  And in the state which has arrange | positioned the exhaust unit 26, the raw prepreg division piece D is affixed and laminated | stacked one by one. In addition, although it is preferable to form a hole through which the pipe 28 passes in the prepreg divided piece D, it can be easily laminated only by widening the interval of the yarn 15 only in a portion through which the pipe 28 passes.

  The yarn 15 is composed of a bundle of a plurality of strands. In this example, a prepreg segment D with a thin strand is arranged on the cavity surface 20S side, and a prepreg segment with a thick strand on the upper side. D is arranged. Thereby, the prepreg division | segmentation piece D can be made to follow a cavity surface more correctly, and the formation precision of the ring main body 4 can be improved. Moreover, since the prepreg segment D with a thick strand is used on the upper side, the strength and rigidity can be maintained high as a whole. It is also preferable to arrange the prepreg segment D with a thin bundle of strands on the cavity surface 20S side and the prepreg segment D with a thick bundle of strands on the upper side. In this case, since the bundle of strands is thick, the prepreg is also thickened, the strength can be increased, and the number of laminations can be reduced, so that the lamination process can be shortened.

The cavity surface 20S is formed in accordance with the surface contour shape of the ring body 4 on the sliding surfaces 6S, 7S side. Accordingly, the strand (or bundle of strands) of the prepreg yarn 15 forming the _first layer P1 is the thinnest. Therefore, the unevenness of the sliding surfaces 6S and 7S can be suppressed from becoming excessively large, which is preferable for exhibiting excellent sliding properties. Note that the thickness of the strands (or bundles of strands) of the prepreg yarn 15 gradually increases toward the _tenth layer P10.

  Since the cavity surface 20S has a U-shaped cross-section, the cavity surface 20S tends to be inferior in pasting workability. Therefore, it is also preferable to divide the prepreg divided piece D into two parts Di and Do inside and outside in the radial direction. At this time, the division position K is preferably set to the region Y in the side wall portion 9. In order to suppress a decrease in strength due to the division, it is preferable that the division positions K in each layer P are dispersed in the region Y in the radial direction. The width of the region Y is about 25 to 35 mm.

  The air discharge port 25 may be formed in the first sliding surface 6S. In this case, the seating work on the seat portion 5 of the bead portion T1 after the raw tire base T is straddled between the bead clamp rings 1 and 1 can be performed more easily and accurately.

  As mentioned above, although especially preferable embodiment of this invention was explained in full detail, this invention is not limited to embodiment of illustration, It can deform | transform and implement in a various aspect.

DESCRIPTION OF SYMBOLS 1 Bead clamp ring 4 Ring main body 5 Seating part 6 1st guide part 6S 1st sliding surface 7 2nd guide part 7S 2nd sliding surface 8 Positioning part 11 Laminated body 15a Warp 15b Weft 16 1st layer 17 1st 2 layer 25 air outlet E circumferential edge De
D Prepreg segment D1 First prepreg segment D2 Second prepreg segment P Layer Q Butting position S Bottom T1 Bead portion X Circumferential width center line

Claims (6)

A bead clamp ring for holding a bead portion of a raw tire,
A cylindrical seating portion for seating and holding the bead portion;
A first cone having a cone shape that is inclined in a direction of reducing the diameter from the seating portion toward the outer side in the axial direction and having a first sliding surface that guides the seat portion from the outer side in the axial direction while sliding the bead portion. Guide,
A positioning portion that rises in a step shape radially outward from the axially inner end of the seating portion;
A second sliding surface that has a cone shape that is inclined in a direction of decreasing in diameter toward the inner side in the axial direction from the radially outer end of the positioning part, and that guides to the seating part side while sliding the bead part from the inner side in the axial direction. A ring body including a second guide having
The ring body is formed of fiber reinforced plastic;
And the bead clamp ring characterized by opening the air discharge port which discharges compressed air and reduces the slip resistance of a bead part in at least one of the said 1st sliding surface or the 2nd sliding surface.   The bead clamp ring according to claim 1, wherein the fiber reinforced plastic is a laminate of prepregs.   The bead clamp ring according to claim 2, wherein the prepreg has a woven member woven with warps and wefts.   Each layer of the laminate is composed of a plurality of prepreg divided pieces divided in the circumferential direction, and each layer is formed by connecting between circumferential edge portions of each prepreg divided piece. The bead clamp ring according to 2 or 3.   5. The bead clamp ring according to claim 4, wherein the laminated body has layers in which circumferential phases of connection positions of the prepreg divided pieces are different between adjacent layers. The prepreg divided piece includes a first prepreg divided piece in which one of the warp or the weft is arranged at an angle α1 of 40 to 50 degrees with respect to a circumferential width center line of the prepreg divided piece, and an angle α2 of ± 5 degrees. And a second prepreg divided piece arranged in a
6. The laminate according to claim 4, wherein the laminate is laminated by combining a first layer made of a first prepreg divided piece and a second layer made of a second prepreg divided piece. The bead clamp ring described.

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