JP5106170B2 - Tire vulcanizing method and tire vulcanizing mold - Google Patents

Description

    The present invention relates to a tire vulcanizing method and a tire vulcanizing mold in which an unvulcanized tire is vulcanized by a mold holding a cereal plate.

As conventional tire vulcanization methods and tire vulcanization molds, for example, those described in the prior art of Patent Document 1 below are known.
JP 2004-345310 A

  These are close to and away from each other, and have a side wall part molding surface that molds the side wall part of the unvulcanized tire, and are held on the side wall part molding surface of the lower and upper molds (normally And a cereal plate (metal plate) provided with an identification mark, which is held by being pushed into a holding recess formed on the side wall molding surface, and stored in the vulcanization space of the upper mold under the closed state When the vulcanized uncured tire is vulcanized, the identification mark on the cereal plate is transferred to the unvulcanized tire.

    When the unvulcanized tire is vulcanized using the tire vulcanization mold as described above, in many cases, the above-mentioned cereal plate comes out of the holding recess of the vulcanization mold and the sidewall portion of the vulcanized tire. Although it adheres to the outer surface, the adhesive force of the cereal plate to the vulcanized tire is weak, so the cereal plate is vulcanized by vibration when the vulcanization mold is opened or when the vulcanized tire is taken out. The cereal plate that was easily detached from the finished tire and dropped to the surroundings, in particular, the upper mold held by the upper mold, slid on the upper side wall of the vulcanized tire and dropped irregularly over a wide area. For this reason, workers have to search and collect small cereal plates in a wide range without difficulty, and as a result, the vulcanization operation is interrupted during this period, resulting in a decrease in tire production efficiency. .

  An object of the present invention is to provide a tire vulcanization method and a tire vulcanization mold that can improve the production efficiency of a tire by suppressing the fall of the cereal plate.

Such a purpose is, firstly, a step of closing the upper mold close to each other while having a sidewall portion molding surface that molds the sidewall portion of the unvulcanized tire, and the closed bottom, A step of vulcanizing the unvulcanized tire stored in the vulcanized space of the upper mold, and when vulcanizing the unvulcanized tire, the holding recess formed on the side wall portion molding surface of the upper mold In the tire vulcanizing method in which an identification mark provided on a held cereal plate is transferred to the unvulcanized tire, a small hole penetrating the cereal plate formed at the time of vulcanization described above, and a communicating hole communicating with the small holes than in diameter said small holes are formed in the sidewall portion typing surface of the upper mold, the tire pressure was set to be filled by flowing rubber unvulcanized tire vulcanization Accordingly, it is possible to achieve.

Second, it is formed on the upper mold and the side wall molding surface of the upper mold, which has a side wall molding surface that can approach and separate from each other and molds the side wall of the unvulcanized tire . A cereal plate that is held in a holding dent and provided with an identification mark, and when the uncured tire stored in the vulcanization space of the upper mold is vulcanized, the identification mark on the cereal plate is In the tire vulcanization mold that is to be transferred to the unvulcanized tire, a small hole that penetrates the cereal plate is formed, while the side wall portion molding surface of the upper mold has a diameter larger than the small hole and the small hole is formed. This can be achieved by a tire vulcanization mold in which communicating holes are formed so that the rubber of the unvulcanized tire flows into the small holes and the communicating holes and is filled during vulcanization.

  In the present invention, a small hole is formed in the cereal plate held by the upper mold, while a communication hole communicating with the small hole is formed in the side wall portion molding surface of the upper mold so that the unvulcanized tire is vulcanized. The rubber filled into the small hole and the communication hole is filled with the rubber, and the rubber flowing into and filled in the small hole and the communication hole becomes a small protrusion integrated with the vulcanized tire by vulcanization.

  Here, since such a small protrusion is difficult to come out from the small hole, the cereal plate is prevented from being detached from the vulcanized tire. As a result, even when the vulcanized tire vibrates when the vulcanization mold is opened or when the vulcanized tire is carried out, there is a situation in which the cereal plate falls off the upper side wall portion of the vulcanized tire. Suppressed and tire production efficiency is improved. Further, when removing the cereal plate from the vulcanized tire, for example, the small protrusions are easily broken simply by grasping and pulling the cereal plate, so that the detaching operation becomes easy.

Further, according to the structure as recited in claim 3, as possible out to the smooth flow of rubber into the communicating hole. Further, if configured as described in claim 4 , it is possible to facilitate excision of the small protrusion while strongly preventing the falling of the cereal plate, and further, if configured as described in claim 5. The holding of the cereal plate to the upper mold is easy and reliable.

Embodiment 1 of the present invention will be described below with reference to the drawings.
In FIG. 1, 11 is a tire vulcanizer, and this tire vulcanizer 11 vulcanizes an unvulcanized tire 12 so that it is a large-sized heavy-duty pneumatic radial used for large construction vehicles or trucks and buses. Manufacture tires. Here, the unvulcanized tire 12 connects a pair of bead portions 13, sidewall portions 14 extending from each bead portion 13 toward the outside in a substantially radial direction, and radially outer ends of the sidewall portions 14. The tread portion 15 is made up of.

  On the other hand, the tire vulcanizing apparatus 11 has a substantially ring-shaped lower mold 18 including a lower platen, and the unvulcanized tire 12 is placed horizontally on the lower mold 18. The lower mold 18 has, on the upper surface of the central portion in the radial direction, a sidewall portion molding surface 19 for performing molding mainly on one side (lower side) sidewall portion 14 of the unvulcanized tire 12. Further, the lower mold 18 has a ring portion 20 extending upward at the radially outer end thereof, and a tread portion 15 of the unvulcanized tire 12 mainly on a radially inner side surface of the ring portion 20. A tread part molding surface 21 for molding one side part (lower part) in the width direction is formed.

  Further, a plurality of lower lug groove bones 24 extending substantially in the axial direction of the lower mold 18 (substantially in the width direction in the horizontally placed unvulcanized tire 12) are provided on the radially inner side surface (tread portion molding surface 21) of the ring portion 20. These lower lug groove bones 24 project radially inward and are arranged equidistantly in the circumferential direction. These lower lug groove bones 24 are pushed into the lower excavation groove 25 formed at one end in the width direction of the tread portion 15 of the unvulcanized tire 12 during vulcanization, and the lower lug is inserted into the tread portion of the pneumatic tire. Form the groove.

  Reference numeral 28 denotes a substantially ring-shaped upper mold that is installed immediately above the lower mold 18 and includes an upper platen. The upper mold 28 is moved up and down by a lifting means (not shown) and is moved closer to and away from the lower mold 18. The upper mold 28 has a sidewall portion molding surface 29 for performing molding on the other side (upper side) sidewall portion 14 mainly of the unvulcanized tire 12 on the lower surface of the central portion in the radial direction. Further, the upper mold 28 has a ring portion 30 extending downward at the radially outer end thereof, and the tread portion 15 of the unvulcanized tire 12 mainly on the radially inner side surface of the ring portion 30. A tread portion molding surface 31 for molding the other side portion (upper portion) in the width direction is formed.

  Further, a plurality of upper lug groove bones 33 extending substantially in the axial direction of the upper mold 28 are formed on the radially inner side surface (tread portion molding surface 31) of the ring portion 30, and these upper lug groove bones 33 are formed in the radial direction. While projecting inward, they are arranged equidistantly in the circumferential direction. These upper lug groove bones 33 are pushed into the upper excavation groove 34 formed at the other end in the width direction of the tread portion 15 of the unvulcanized tire 12 during vulcanization, and the upper lug groove bones 33 are raised to the tread portion of the pneumatic tire. Form lug grooves. In this embodiment, while the lower mold 18 is stationary, the upper mold 28 is moved up and down to move the upper molds 18 and 28 apart from each other. However, while the upper mold 28 is stationary, the lower mold 18 The upper molds 18 and 28 may be moved closer to and away from each other by moving the lower molds up and down or by moving both the lower and upper molds 18 and 28 up and down.

  Reference numeral 38 denotes a shaping unit. The shaping unit 38 has a one-side support 39 on which a bead portion 13 positioned on one side (lower side) in the width direction of the unvulcanized tire 12 is seated. 39 can mainly mold the bead 13 on one side in the width direction during vulcanization. Reference numeral 40 denotes an other side support on which a bead portion 13 positioned on the other side (upper side) of the unvulcanized tire 12 is seated, and this other side support 40 is a bead on the other side in the width direction during vulcanization. The part 13 can be mainly typed. And these one side and other side support bodies 39 and 40 are connected so that attachment or detachment is possible by the connection mechanism which is not shown in figure. Reference numeral 42 denotes a bendable bladder in which both ends in the width direction, that is, one end and the other end in the width direction are locked to the one side and other side supports 39 and 40 in an airtight state.

  And after one side of the unvulcanized tire 12 and the other side bead portion 13 are seated on the one side, the other side support bodies 39, 40, respectively, the one side, the other side support bodies 39, 40 are connected to each other. When the internal pressure is filled in the bladder 42 after being connected by the mechanism, the unvulcanized tire 12 is deformed into a substantially toroidal shape, while the one side, the other side support 39, 40, and the bladder 42 are It is supported by the shaping unit 38. Next, the unvulcanized tire 12 mounted on the shaping unit 38 in this way is carried into the upper molds 18 and 28 in an open state by a conveying means (not shown), and then the lower lug groove bone 24 and the lower excavation groove 25 are placed on the lower mold 18 while matching.

  In FIGS. 1, 2, and 3, 45 and 46 are rectangular holding dents formed on the side wall portion molding surfaces 19 and 29 slightly inward of the lower and upper lug groove bones 24 and 33, respectively. The bottom walls of the recesses 45 and 46 are formed of a flat surface substantially parallel to a tangent to the side wall molding surfaces 19 and 29 at the positions of the holding recesses 45 and 46. Reference numerals 47 and 48 denote cereal plates made of a thin steel plate, and these cereal plates 47 and 48 have a rectangular shape substantially the same as the side wall portion molding surfaces 19 and 29. The serial plates 47 and 48 may be made of a metal plate such as stainless steel or aluminum.

  Here, these serial plates 47 and 48 are each provided with an identification mark 50 made of letters, numbers, symbols, figures, etc., such as a production number, production date, manufacturer name, etc. by stamping with a press device or the like. When these identification marks 50 are imprinted on the pneumatic tire by transfer, it becomes easy to identify the type and the like of the manufactured pneumatic tire. Further, the identification mark 50 is disposed substantially equidistantly in the longitudinal direction of the serial plates 47 and 48, and protrudes from the back surface toward the front surface (above the paper surface in FIG. 3).

  The cereal plates 47 and 48 are provided so that the back surface of the dents 45 and 46 is fixed to the bottom of the holding dents 45 and 46 by the operator before the unvulcanized tire 12 is carried into the tire vulcanizing device 11. By being pushed in until it comes into contact with the wall, the lower and upper molds 18 and 28 are respectively held on the side wall portion molding surfaces 19 and 29. Further, when the serial plates 47 and 48 are made of a ferromagnetic material such as steel as described above, the side wall portion molding surface 29 of the upper mold 28, in this case, is held as in this embodiment. It is preferable to embed a plurality of permanent magnets 52 in the bottom wall of the recess 46 and attract the cereal plate 48 by the permanent magnets 52.

  The reason for this is that this makes it easy and reliable to hold the cereal plate 48 on the upper mold 28, and the cereal plate 48 falls from the upper mold 28 even when the upper mold 28 moves up and down before vulcanization starts. This is because it can be effectively suppressed with a simple structure. The lower molds 18 and 28 and the cereal plates 47 and 48 constitute a tire vulcanizing mold 55 as a whole, and the upper molds 18 and 28 are closed under the vulcanizing mold 55 to vulcanize the space 56. After the unvulcanized tire 12 is stored in the tire, when the unvulcanized tire 12 is vulcanized, the identification mark 50 of the cereal plates 47 and 48 is transferred to the surface of the sidewall portion 14 of the tire.

  When the identification mark 50 is transferred to the tire in this way, a dent (identification mark) complementary to the identification mark 50 is formed on the outer surface of the pneumatic tire. The identification mark 50 may protrude from the front surface of the cereal plates 47, 48 toward the back surface. In this case, a protrusion complementary to the identification mark 50 is formed on the outer surface of the pneumatic tire. .

  Here, a total of two small holes 53 penetrating in the thickness direction are formed at both ends in the longitudinal direction of the serial plate 48 held by the upper mold 28, and these small holes 53 have a circular cross section. The diameter is constant at any position in the thickness direction. Note that only one small hole 53 may be formed in the central portion in the longitudinal direction, or three or more may be formed apart in the longitudinal direction, but the appearance of the pneumatic tire is improved. For the above, the aforementioned positions are preferable. The cross section of the small hole 53 may be a quadrangle, a hexagon, an ellipse, or the like.

A total of two communication holes 59 communicating with the small holes 53 are formed at both end portions in the longitudinal direction on the side wall molding surface 29 of the upper mold 28, more specifically, the bottom wall of the holding recess 46, and these communication holes 59 has a circular cross section, is coaxial with the small hole 53, and has a larger diameter. As a result, a part of these communication holes 59, here the radially outer end (outer edge), protrudes laterally (outward in the radial direction) from the outer edge of the small hole 53 over the entire circumference . Their to these small holes 53, the communication hole 59, the unvulcanized rubber constituting the unvulcanized tire 12 during vulcanization flows by the flow, is filled into these internal.

  The rubber that has flowed into and filled into the small holes 53 and the communication holes 59 in this way, as shown in FIG. 4, protrudes from the sidewall portion 14 and is integrated with the vulcanized tire 64 (pneumatic tire). The small projections 60 are composed of a base end portion 61 made of rubber in the small hole 53 and a tip end portion 62 made of rubber in the communication hole 59. Since the communication hole 59 has a larger diameter than the small hole 53 as described above, a step 63 is formed at the boundary with the portion 62.

  Here, since the small protrusions 60 as described above are difficult to be removed from the small holes 53, the cereal plate 48 is prevented from being detached from the vulcanized tire 64. As a result, even if the vulcanized tire 64 vibrates when the vulcanization mold 55 is opened or when the vulcanized tire 64 is carried out, the cereal plate 48 is detached from the upper sidewall portion 14 of the vulcanized tire 64. The situation where the vehicle falls into a wide area is suppressed, and the tire production efficiency is improved.

  Further, in this embodiment, a portion of the tip end portion 62 of the small protrusion 60 formed by the communication hole 59 projects laterally from the small hole 53, here, a radially outer end portion (step difference) of the tip portion 62. 63) comes into contact with the back surface of the cereal plate 48 and functions as a catch, so that the detachment of the cereal plate 48 from the vulcanized tire 64 is further strongly suppressed.

  Thereafter, the cereal plate 48 is removed from the vulcanized tire 64. At this time, the small protrusion 60 is easily broken at the base end portion 61 simply by grasping and pulling the cereal plate 48. The removal work of the cereal plate 48 from 64 becomes easy. Further, the small protrusion 60 can be extracted from the cereal plate 48 only by pulling the tip 62 protruding from the cereal plate 48, and the operation is easy.

Here, if the small hole 53 and the communication hole 59 are arranged so that their central axes are coaxial, the inflow of rubber into the communication hole 59 becomes smooth and the communication hole 59 is easily filled with rubber. This is preferable. Further, as described above, if the communication hole 59 has a larger diameter than the small hole 53, the ring-shaped step 63 around the small hole 53 uniformly contacts the back surface of the serial plate 48, Ru can be strongly prevented the fall of the back real plate 48.

Further, the cross-sectional area of the small hole 53 described above is preferably in the range of 3 to 16 mm ² . The reason is that if the cross-sectional area of the small hole 53 is less than 3 mm ² , the strength of the base end portion 61 of the small protrusion 60 formed by the small hole 53 is low, and the fall of the cereal plate 48 cannot be sufficiently prevented. On the other hand, if it exceeds 16 mm ² , the strength of the base end portion 61 becomes high, and it may be difficult to cut off the small protrusions 60 by hand. This is because excision of the small protrusion 60 can be facilitated while strongly preventing the above.

  It should be noted that the cereal plate 47 held by the lower mold 18 falls only in a narrow range just below it even if it is removed from the vulcanized tire 64 when the vulcanizing mold 55 is opened or the vulcanized tire 64 is taken out. Because it does not, recovery is easy. For this reason, it is not necessary to provide small holes and communication holes similar to the small holes 53 and the communication holes 59 described above in the serial portion 47 and the side wall molding surface 19 of the lower mold 18 (the bottom wall of the holding recess 45). However, in this embodiment, in order to facilitate the recovery of the serial plate 47, detailed description is omitted also on the serial portion 47 and the side wall portion molding surface 19 of the lower mold 18, but a small hole and a communication hole are provided. Yes.

Next, the operation of the first embodiment will be described.
When manufacturing the pneumatic tire as described above, first, after one side, one side of the unvulcanized tire 12 and the other side bead portion 13 are seated on the other side support 39, 40, these one side The other side supports 39 and 40 are connected to each other by a connecting mechanism, and then the bladder 42 is filled with internal pressure. As a result, the unvulcanized tire 12 is attached to the shaping unit 38 while being deformed in a substantially toroidal shape. Thereafter, a plurality of lower and upper excavation grooves 25 and 34 are formed at one end and the other end in the width direction of the tread portion 15 using an electric heat cutter or the like.

  At this time, in the vulcanization mold 55, the operator touches the bottom plate of the holding recesses 45, 46 with the cereal plates 47, 48 in the holding recesses 45, 46 of the upper molds 18, 28 at the bottom. The cereal plates 47 and 48 are held by the lower and upper molds 18 and 28, respectively. Next, the shaping unit 38 and the unvulcanized tire 12 described above are carried into the open vulcanization mold 55 by the conveying means, and the lower mold is made while the lower lug groove bone 24 and the lower excavation groove 25 are matched. 18 on.

  Next, the upper mold 28 is lowered by the lifting means, the upper molds 18 and 28 are brought close to each other, and the vulcanizing mold 55 is closed. At this time, the cereal plate 48 is moved upward by the attractive force of the permanent magnet 52. Since the mold 28 is securely held, the cereal plate 48 hardly falls from the upper mold 28 even when the upper mold 28 vibrates. And when the unvulcanized tire 12 is closed and stored in the vulcanization space 56 between the upper molds 18 and 28, the lower, under the upper molds 18 and 28, in the upper platen and in the bladder 42, A high-pressure vulcanization medium is supplied, and the unvulcanized tire 12 stored in the vulcanization space 56 is vulcanized to produce a vulcanized tire 64 (pneumatic tire).

  At this time, since the identification mark 50 of the cereal plates 47 and 48 is transferred and stamped on the surface of the sidewall portion 14 of the unvulcanized tire 12, the outer surface of the pneumatic tire has a complementary relationship with the identification mark 50. A dent (identification mark) is formed, which makes it possible to easily identify the type of pneumatic tire. Further, during the vulcanization described above, the rubber constituting the unvulcanized tire 12 is heated to increase the fluidity, so that the rubber 53 is pushed by the internal pressure of the bladder 42 and the small holes 53 of the cereal plates 47, 48 and the lower, upper, It flows into the communication holes 59 of the molds 18 and 28 and fills them.

  When the vulcanization as described above is completed, the rubber that has flowed into the small hole 53 and the communication hole 59 is cured by vulcanization in the vulcanized tire 64, and a small protrusion 60 is formed on the surface of the sidewall portion 14. Is done. Thereafter, the upper mold 28 is raised by the lifting means to open the vulcanizing mold 55. At this time, the cereal plate 48 comes out of the holding recess 46 due to the adhesive force of rubber and the small protrusion 60, and the side of the pneumatic tire. It adheres to the outer surface of the wall 14.

  Here, if the adhesive force of the cereal plate 48 is only the above-mentioned adhesive force, the cereal plate 48 is easily detached from the pneumatic tire and falls to the surroundings, but in this embodiment, the cereal plate 48 is a vulcanized tire. Since the small protrusions 60 prevent the detachment from the 64, even if the vulcanized tire 64 vibrates when the vulcanization mold 55 is opened or when the vulcanized tire 64 is carried out, the cereal plate 48 remains on the upper side. There is almost no detachment from the sidewall portion 14.

  On the other hand, the cereal plate 47 also comes out of the holding recess 45 and adheres to the surface of the lower side wall portion 14 of the vulcanized tire 64. Similarly, the small protrusions also prevent the cereal plate 47 from being detached from the vulcanized tire 64. However, there is almost no detachment from the vulcanized tire 64. Thereafter, the vulcanized tire 64 is carried out to the next process by the conveying means. In this next process, the operator removes the cereal plates 47 and 48 from the vulcanized tire 64. At this time, the small projections 60 are easily broken simply by grasping and lightly pulling the cereal plates 47, 48, so that the cereal plates 47, 48 can be easily removed from the vulcanized tire 64.

    In the above-described embodiment, the unvulcanized tire 12 is vulcanized by the lower and upper molds 18 and 28. However, in the present invention, the lower and upper molds are disposed between the unmolded tires 12 and are not yet vulcanized. Vulcanization may be performed using a small sector mold that molds only the center portion of the tread portion 15 of the vulcanized tire 12 or a large sector mold that molds almost the entire region of the tread portion 15.

Further, in the invention of this has been the constant regardless of cross-sectional area of the communicating hole 59 in the depth position, in the present invention, may be gradually as a small accordance deeper the cross-sectional area.

  The present invention can be applied to the industrial field in which an unvulcanized tire is vulcanized by a mold holding a cereal plate.

It is the front view in which a part which shows Embodiment 1 of this invention was fractured | ruptured. It is an expanded front sectional view of the vicinity of the cereal plate held by the upper mold. It is the II arrow directional view of FIG. It is an expanded front sectional view near the cereal plate adhering to the vulcanized tire.

12 ... Unvulcanized tire 14 ... Side wall
18… Lower mold 19, 29… Side wall molding surface
28… Upper mold 47, 48… Cerial plate
50 ... Identification sign 52 ... Permanent magnet
53 ... Small hole 55 ... Vulcanization mold
56 ... Vulcanization space 59 ... Communication hole

Claims (5)

A process of closing the upper mold close to each other, having a side wall molding surface for performing molding on the side wall of the unvulcanized tire, and the closed bottom, the lower mold was stored in the vulcanization space of the upper mold A step of vulcanizing the unvulcanized tire, and when the unvulcanized tire is vulcanized, the tire is provided on a cereal plate held in a holding recess formed on the side wall portion molding surface of the upper mold. In the tire vulcanizing method in which the identification mark is transferred to the unvulcanized tire, the pierced small hole formed in the cereal plate and the side wall portion molding surface of the upper mold during the vulcanization described above. A tire vulcanizing method, wherein a rubber of an unvulcanized tire is caused to flow into a communication hole that is formed and has a diameter larger than that of the small hole and communicates with the small hole. The upper mold and the holding recess formed on the side wall of the upper mold are held under a side wall that is moldable to the side wall of the unvulcanized tire. And a cereal plate provided with an identification mark, and when the unvulcanized tire stored in the vulcanization space of the upper mold is vulcanized under the closed state, the identification mark on the cereal plate is placed on the unvulcanized tire. In the tire vulcanization mold designed to be transferred to the communication hole, a small hole penetrating the cereal plate is formed, and a communication hole communicating with the small hole has a larger diameter than the small hole on the side wall portion molding surface of the upper mold. A tire vulcanization mold characterized in that, during vulcanization, rubber of an unvulcanized tire flows into small holes and communication holes to be filled.     The tire vulcanization mold according to claim 2, wherein a central axis of the small hole and a central axis of the communication hole are coaxial. Claim 2 or 3 tire vulcanization mold according to the cross-sectional area of the small holes was in the range of 3～16Mm ^2. Thereby forming the cell real plate of a ferromagnetic material, it is embedded permanent magnets in the sidewall portion typing surface of the upper mold, according to any one of claims 2-4 which is adapted to adsorb Se real plate by the permanent magnet Tire vulcanization mold.

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