JP7005949B2 - Tire manufacturing method and equipment - Google Patents

Description

The present invention relates to a tire manufacturing method and device, and more particularly, a tire manufacturing method and device capable of efficiently manufacturing a high-quality tire by minimizing air remaining inside a green tire. It is about.

In the tire manufacturing process, generally, tire components such as unvulcanized rubber members and reinforcing members are laminated to form a green tire, and the green tire is pressurized and heated in a vulcanizing mold to form a tire. Is being manufactured. Since various tire components are laminated on a green tire, air remains inside the tire. If the residual amount of air inside the tire is excessive, problems such as a vulcanization failure occurring in the manufactured tire and a long vulcanization time occur. Along with this, the quality of the manufactured tires deteriorates and the productivity decreases.

Conventionally, various proposals have been made to remove air between the vulcanization mold and the green tire by a suction means provided in the vulcanization apparatus (see, for example, Patent Document 1). However, when a tire is manufactured using a vulcanizer provided with a suction means, the green tire is vulcanized from the time when it is placed in the vulcanization mold, so that the air remaining inside the tire is sucked. Will be carried out while the vulcanization of the green tire is in progress. As the vulcanization of the green tire progresses, the unvulcanized rubber becomes hard (there is no fluidity) and the tire components and the ridge are integrated. Therefore, the air inside the tire is difficult to move freely and cannot be sufficiently removed.

In addition, since the work of sucking air is added in the vulcanization process, the operation becomes complicated. Along with this, it becomes disadvantageous for improving work efficiency (productivity). Since it is necessary to add suction means to the production equipment, there is also a problem that the existing vulcanization equipment cannot be used as it is.

Japanese Unexamined Patent Publication No. 11-207745

An object of the present invention is to provide a tire manufacturing method and apparatus capable of efficiently manufacturing a tire having excellent quality by minimizing the air remaining inside the green tire.

In order to achieve the above object, the tire manufacturing method of the present invention is to provide a bag body having an annular shape inside and forming a sealed space without a green tire by airtightly engaging a plurality of members . By putting the green tire inside in a state before the plurality of members are airtightly engaged and then airtightly engaging the plurality of members and drawing a vacuum inside the sealed bag body. The bag body is contracted to maintain this vacuumed state for a predetermined time, and during this predetermined time, the air remaining inside the green tire is removed while the inner surface of the bag body is brought into close contact with the surface of the green tire. It is characterized in that the green tire is discharged to the outside of the bag body, and then the green tire is taken out from the bag body and placed in a smelting mold for smelting.

In the tire manufacturing apparatus of the present invention, a plurality of members are airtightly engaged to form a sealed space having an annular shape inside without the green tire, and the plurality of members are airtightly engaged. A bag body capable of sealing the green tire inside by airtightly engaging the plurality of members after the green tire is put inside in a state before being combined, and a bag body of the bag body. A state in which the inside of the bag body in which the green tire is sealed is evacuated by the suction means is maintained for a predetermined time with a suction means for evacuating the inside, and the inside is evacuated for this predetermined time. The inner surface of the shrunk bag body is in close contact with the surface of the green tire, and the air remaining inside the green tire is discharged to the outside of the bag body.

According to the present invention, the green tire before being placed in the vulcanization mold is sealed in the bag body and the inside of the bag body is evacuated, so that the air remaining inside the green tire moves. It will be evacuated under conditions that are easy to do. Therefore, maintaining this evacuated state for a predetermined time is advantageous for sufficiently removing air from the inside of the green tire. In addition, since the bag body is brought into close contact with the surface of the green tire in a vacuumed state, the air remaining inside the green tire expands due to this vacuuming, causing problems such as local deformation of the green tire. It can be avoided. Therefore, according to the present invention, it is possible to minimize the air remaining inside the green tire, and accordingly, it is possible to efficiently manufacture a tire having excellent quality.

It is explanatory drawing which illustrates the whole outline of the manufacturing process of the tire which used this invention. It is explanatory drawing which illustrates the tire manufacturing apparatus of this invention in the side view of a drum. It is explanatory drawing which enlarges and exemplifies the inside of the accommodating part of FIG. 2 in the cross-sectional view. It is explanatory drawing which illustrates the periphery of the through hole of the inner surface of the bag body of FIG. 3 in a plan view. It is explanatory drawing which illustrates the air bleeding process which removes the air which remains inside a green tire in the cross-sectional view. It is explanatory drawing which illustrates another embodiment of the manufacturing apparatus of this invention.

Hereinafter, the method and apparatus for manufacturing a tire of the present invention will be described based on the embodiment shown in the figure.

As illustrated in FIG. 1, the tire T is manufactured through the molding step S1, the air bleeding step S2, and the vulcanization step S3 in this order. In the molding step S1, various tire constituent members M are laminated by a molding device 7 such as a molding drum to form a green tire G1. In the air bleeding step S2, the tire manufacturing apparatus 1 of the present invention is used to remove the air a remaining inside the green tire G1 to form the green tire G2.

In the vulcanization step S3, the green tire G2 is arranged in the vulcanization mold 8a. Next, the green tire G2 is vulcanized (pressurized and heated) by the vulcanizer 8, so that the vulcanized tire T is completed.

The tire manufacturing apparatus 1 of the present invention exemplified in FIGS. 2 to 4 has a bag body 2 capable of sealing the green tire G1 and a suction pump 4 as a suction means for evacuating the inside of the bag body 2. And have. In this embodiment, the manufacturing apparatus 1 further includes an accommodating portion 3 accommodating the bag body 2 and a pressurizing pump 5 for pressurizing the inside of the accommodating portion 3. The accommodating portion 3 and the pressurizing pump 5 form a pressurizing means for pressurizing the bag body 2 from the outside. This pressurizing means can be optionally provided.

The bag body 2 has an annular shape, and the inside of the bag body 2 has substantially the same shape as the outer shell shape of the green tire G1. The bag body 2 is formed of, for example, vulcanized rubber or the like. In this embodiment, the bag body 2 is composed of an inner portion 2A that mainly covers the inner surface of the green tire G1 and an outer portion 2B that mainly covers the outer surface of the green tire G1. The inner portion 2A and the outer portion 2B are airtightly engaged with each other, and the inside of the bag body 2 becomes a sealed space. The bag body 2 is not limited to the illustrated form, and may be composed of three or more members.

The bag body 2 and the suction pump 4 are connected to each other through a suction line 4a. The suction line 4a is connected to a through hole 2h formed in the bag body 2. In this embodiment, the through hole 2h is formed in the outer portion 2B, but the through hole 2h can be formed in the inner portion 2A in addition to or in place of the outer portion 2B. The through hole 2h is not limited to the position exemplified in this embodiment and can be formed at an appropriate position.

The suction line 4a is provided with an on-off valve 4b. By operating the suction pump 4 with the on-off valve 4b opened, the inside of the bag body 2 is evacuated.

The number of suction lines 4a is not limited to one, and may be multiple. When a plurality of suction lines 4a are provided, the connection positions (that is, through holes 2h) between the respective suction lines 4a and the bag body 2 may be arranged at equal intervals in the circumferential direction of the bag body 2, for example. With such an arrangement, the inside of the bag 2 can be easily evacuated evenly by reducing the variation in the circumferential direction, which contributes to the improvement of the quality of the manufactured tire T.

In this embodiment, as illustrated in FIG. 4, a concave groove 2g extending toward the through hole 2h is formed on the inner surface 2i of the bag body 2. The groove width and groove depth of the concave groove 2 g are, for example, 2 mm to 10 mm.

The accommodating portion 3 is, for example, a rigid body, and a metal box body can be used. The accommodating portion 3 has a sufficient size to accommodate the bag body 2. In this embodiment, the accommodating portion 3 has an opening / closing lid 3a, and by closing the opening / closing lid 3a, the inside of the accommodating portion 3 becomes a sealed space. The suction pump 4 is arranged outside the accommodating portion 3, and the suction line 4a penetrates the wall surface constituting the accommodating portion 3.

The accommodating portion 3 and the pressurizing pump 5 are connected to each other through a pressurizing line 5a. The pressurizing line 5a is provided with an on-off valve 5b. By operating the pressurizing pump 5 with the on-off valve 5b opened, the bag body 2 housed in the accommodating portion 3 is pressurized from the outside.

Next, a procedure of a tire manufacturing method using this manufacturing apparatus 1 will be described.

First, in the molding step S1, a plurality of tire constituent members M are laminated to form a green tire G1 by a known molding method using a molding apparatus 7. The tire component member M is a known member such as an inner liner M1, a carcass material M2, a bead portion M3, a side rubber M4, a belt layer M5, and a tread rubber M6.

In the green tire G1 molded in the molding step S1, air a remains between the tire constituent members M. Therefore, in the air bleeding step S2, the green tire G2 from which the air a is removed from the green tire G1 is molded by using the manufacturing apparatus 1 of the present invention. The air bleeding step S2 is performed in a temperature range (for example, normal temperature to 80 ° C.) at which vulcanization of the green tire G1 does not proceed.

For the green tire G1, it is possible to perform a work (so-called pricking work) in which a needle-shaped body is pierced from the outer surface to form an air bleeding hole for communicating the laminated tire constituent members M in advance. preferable. However, be careful not to let the air vent hole penetrate the inner liner M1.

In the air bleeding step S2, the green tire G1 is put in the bag body 2 and sealed as illustrated in FIG. In this state, the inner surface 2i of the bag body 2 is in close contact with the surface of the green tire G1. Next, the inside of the bag body 2 is evacuated by operating the suction pump 4, and the evacuated state is maintained for a predetermined time.

The vacuum pressure in this evacuation is, for example, -30 kPa to -101.3 kPa in terms of the gauge pressure at which the atmospheric pressure (101.3 kPa) is set to zero. The predetermined time for maintaining the evacuated state is preferably 3 minutes or more rather than 1 minute or more. For example, it is preferable to maintain the inside of the bag 2 in a vacuumed state within the waiting time until the green tire G2 is vulcanized.

The inner surface 2i of the bag body 2 is always in close contact with the surface of the green tire G1 for a predetermined time during which the vacuumed state is maintained. For example, the inner surface 2i of the bag 2 may be in close contact with 70% or more, more preferably 80% or more of the total surface area of the green tire G1. At the time when the green tire G1 is sealed in the bag body 2, even if the inner surface 2i of the bag body 2 is not in close contact with the surface of the green tire G1, the bag body 2 contracts by vacuuming and the green tire G1 It suffices to adhere to the surface of the tire.

In the present invention, since the inside of the bag body 2 in which the green tire G1 before being placed in the vulcanization mold 8a is sealed is vacuumed, the green tire G1 is placed in the vulcanization mold 8a and vacuumed. The air a remaining inside the green tire G1 is vulcanized under conditions where it is easy to move inside the tire. Therefore, by maintaining this evacuated state for a predetermined time, the air a can be sufficiently removed from the inside of the green tire G1. That is, it is possible to minimize the air a remaining inside the green tire G1.

If vacuuming is performed while the bag body 2 is not in close contact with the surface of the green tire G1, the air a remaining inside the green tire G1 expands due to this vacuuming, and the green tire G1 locally becomes. Problems such as deformation may occur. However, in the present invention, since the inner surface 2i of the bag body 2 is in close contact with the surface of the green tire G1, local deformation of the green tire G1 due to such expansion of the air a is regulated by the bag body 2. Can be avoided.

In this embodiment, the pressurizing pump 5 is operated at the same time as the suction pump 4 is operated. Therefore, the bag body 2 is pressed from the outside by the pressurization (pressurization pressure P) by the pressurizing pump 5. This pressurizing pressure P is, for example, 100 kPa to 1000 kPa. Since this pressurization on the bag body 2 promotes the discharge of the air a remaining inside the green tire G1 to the outside, it becomes more and more advantageous to minimize the remaining air a.

After molding the green tire G2 from which the air a has been removed as described above, the green tire G2 is taken out from the bag body 2 and conveyed to the vulcanization step S3. In the vulcanization step S3, the pneumatic tire T is manufactured by arranging the green tire G2 in the vulcanization mold 8a and vulcanizing it by the vulcanization apparatus 8.

Since the amount of air a remaining in the green tire G2 is minimized, it is possible to prevent the vulcanized tire T from having a problem due to a vulcanization failure. Further, since the residual air a is minimized, the vulcanization time is not lengthened more than necessary. Therefore, it is advantageous to efficiently manufacture the tire T having excellent quality.

Moreover, according to the present invention, it is not necessary to modify the existing molding apparatus 7 or vulcanization apparatus 8. That is, there is an advantage that the existing molding apparatus 7 and vulcanization apparatus 8 can be used as they are. Further, there is an advantage that the operations of the molding step S1 and the vulcanization step S3 do not change. The present invention can be applied to any of radial tires and bias tires.

In this embodiment, the air a can be guided to the through hole 2h along the concave groove 2g formed on the inner surface 2i of the bag body 2, which is advantageous for minimizing the air a remaining in the green tire G2. ing. The concave groove 2g can be arbitrarily provided, but by providing the concave groove 2g or the like to make the inner surface 2i of the bag body 2 uneven, the air a can be smoothly discharged to the outside of the bag body 2. Further, by making the inner surface 2i uneven, there is an advantage that when the green tire G2 is taken out from the bag body 2, the green tire G2 in close contact with the bag body 2 can be easily peeled off from the inner surface 2i.

In another embodiment of the manufacturing apparatus 1 illustrated in FIG. 6, a plurality of bag bodies 2 are arranged in a storage 6 in which a green tire G2 waiting for vulcanization is stored. Each bag 2 is housed in a storage unit 3, and a suction pump 4 is connected to the suction line 4a. Further, a pressurizing pump 5 is connected to each accommodating portion 3 through a pressurizing line 5a.

In this embodiment, a plurality of bag bodies 2 are connected to the same one suction pump 4, but individual suction pumps 4 may be connected to each bag body 2. Although a plurality of accommodating portions 3 are connected to the same one pressurizing pump 5, an individual pressurizing pump 5 may be connected to each accommodating portion 3.

The green tire G1 molded in the molding step S1 is sealed in the bag body 2, and the bag body 2 in which the green tire G1 is sealed is housed in the accommodating portion 3 and transported to the storage 6. In the storage 6, the suction line 4a is connected to the conveyed bag body 2, and the pressurizing line 5a is connected to the accommodating portion 3. After that, the on-off valves 4b and 5b are opened to start sucking the inside of the conveyed bag body 2 and to pressurize the bag body 2 from the outside. It is better to open the on-off valve 4b and suck the inside of the bag body 2 first, and after a few minutes, open the on-off valve 5b and start pressurizing the bag body 2 from the outside. The discharge effect may be high.

In the storage 6, the inside of the bag 2 is continuously evacuated by the suction pump 4. Along with this evacuation, the bag body 2 is continuously pressurized by the pressurizing pump 5 from the outside. It is advisable to effectively utilize the time in which the green tire G2 is stocked for waiting for vulcanization in order to maintain the state in which the inside of the bag body 2 is evacuated. As a result, no wasted time is generated in the tire manufacturing process, which is advantageous for improving productivity.

When the vulcanizer 8 becomes empty, the accommodating portion 3 accommodating the green tire G2 to be vulcanized next is separated from the suction line 4a and the pressurizing line 5a and transported from the storage 6 to a predetermined work place. Will be done. At the work place of the transport destination, the green tire G2 is taken out from the accommodating portion 3 and the bag body 2. The removed green tire G2 is placed in the vulcanization mold 8a and vulcanized.

The temperature (room temperature) of the storage 6 may be room temperature, but may be, for example, 40 ° C to 80 ° C. If the temperature of the green tire G1 (G2) is too low, the air a may not move easily and may not be sufficiently removed. Therefore, by heating appropriately (40 ° C to 80 ° C) within the range where vulcanization does not proceed, , It is advantageous to minimize the residual air a.

1 Tire manufacturing equipment 2 Bag body 2A Inner part 2B Outer part 2g Recessed groove 2h Through hole 2i Inner surface 3 Accommodating part 3a Opening / closing lid 4 Suction pump 4a Suction line 4b On / off valve 5 Pressurizing pump (compressor)
5a Pressurizing line 5b On-off valve 6 Storage 7 Molding device 8 Vulcanization device 8a Vulcanization mold G1 Green tire before air removal G2 Green tire after air removal T Vulcanized tire M (M1 to M6) Tire configuration Member a air

Claims (6)

By airtightly engaging a plurality of members, a bag body having an annular shape inside and forming a sealed space without a green tire is made into a state before the plurality of members are airtightly engaged. After putting the green tire inside, the inside of the sealed bag body is airtightly engaged with the plurality of members and the inside of the bag body is evacuated to contract the sack body, and the evacuated state is determined. The time is maintained, and during this predetermined time, the air remaining inside the green tire is discharged to the outside of the green tire while the inner surface of the bag is brought into close contact with the surface of the green tire, and then the green tire is discharged. A method for manufacturing a tire that is taken out of the bag and placed in a smelting mold for smelting. By accommodating the entire bag body in which the green tire is sealed in the accommodating portion and maintaining the state in which the inside of the bag body is evacuated for a predetermined time, the inside of the accommodating portion is pressurized by a pressurizing pump. The method for manufacturing a tire according to claim 1, wherein the bag body is pressurized from the outside. The method for manufacturing a tire according to claim 1 or 2, wherein the green tire is stored in a storage while maintaining the state in which the inside of the bag is evacuated for a predetermined time. By airtightly engaging a plurality of members, the inside has an annular shape without a green tire to form a sealed space, and the inside is in a state before the plurality of members are airtightly engaged. A bag body capable of sealing the green tire inside by airtightly engaging the plurality of members after inserting the green tire, and a suction means for evacuating the inside of the bag body. In preparation, the inside of the bag body in which the green tire is sealed is maintained in a state of being evacuated by the suction means for a predetermined time, and the bag body is shrunk by being evacuated during this predetermined time. A tire manufacturing apparatus having a configuration in which the inner surface is in close contact with the surface of the green tire and the air remaining inside the green tire is discharged to the outside of the bag body. A state in which the inside of the bag body is evacuated by providing a pressurizing means having a housing portion for accommodating the entire bag body in which the green tire is sealed and a pressurizing pump for pressurizing the inside of the housing portion. The tire manufacturing apparatus according to claim 4, wherein the bag body is externally pressurized by the pressurizing means while the tire is maintained for a predetermined time. The tire manufacturing apparatus according to claim 4 or 5, wherein the storage is stored before the green tire is vulcanized, and the inside of the bag is evacuated for a predetermined time. ..

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