JP2016112777A - Method and device for producing pneumatic tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device for producing a pneumatic tire for further improving tire quality by properly controlling a rubber volume in producing a pneumatic tire by vulcanizing an unvulcanized rubber in a space between a rigid inner mold and a vulcanizing mold disposed on the outer peripheral side of the rigid inner mold.SOLUTION: An unvulcanized base tire BT is disposed on an outer peripheral surface of a cylindrical metallic rigid inner mold 2 divisible into a plurality in the circumferential direction, the base tire BT together with the rigid inner mold 2 are disposed in a vulcanizing mold 6 and then the base tire BT is vulcanized, an unvulcanized rubber R is injected into a cavity 9 formed between an inner peripheral surface of the vulcanizing mold 6 and an outer peripheral surface of the base tire BT, the unvulcanized rubber R is vulcanized to form the tread part TR on the outer peripheral surface of the base tire BT, and the tread part TR is integrated on the outer peripheral surface of the base tire BT.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a method and an apparatus for manufacturing a pneumatic tire, and more specifically, vulcanizes unvulcanized rubber between a rigid inner mold and a vulcanization mold disposed on the outer peripheral side of the rigid inner mold. Thus, the present invention relates to a method and an apparatus for manufacturing a pneumatic tire capable of further improving tire quality by appropriately controlling a rubber volume when manufacturing a pneumatic tire.

  Conventionally, a method for producing a pneumatic tire has been proposed in which a green tire is arranged on the outer peripheral side of a rigid inner mold, and the green tire is vulcanized by placing the green tire in a vulcanizing mold together with the rigid inner mold. Has been. Unlike the vulcanization bladder, the rigid inner mold does not expand during vulcanization, so it retains its original shape. Therefore, the interval between the rigid inner mold and the vulcanizing mold arranged on the outer peripheral side thereof remains unchanged. Therefore, a vulcanization failure occurs unless the rubber volume of the green tire is accurately controlled to obtain an appropriate volume. In addition, the tire quality is adversely affected, for example, the uniformity of the manufactured pneumatic tire is deteriorated.

  In order to avoid such a problem, a resin film is arranged on the inner peripheral surface of the green tire arranged on the outer peripheral side of the rigid inner mold, and this resin film is pressurized from the inner peripheral side and inflated during vulcanization. A method has been proposed (see Patent Document 1). In the method proposed in Patent Document 1, since the resin film functions as a vulcanized bladder, the inflated resin film presses the unvulcanized rubber forming the green tire to the outer peripheral side. Thereby, since the pressed unvulcanized rubber flows, for example, even if there is a rubber volume deviation in the tire circumferential direction, it is corrected. However, when the bias of the rubber volume of the green tire is excessive, there is a problem that the bias cannot be sufficiently corrected by pressing with a resin film.

JP 2009-149034 A

  An object of the present invention is to provide a rubber volume when a pneumatic tire is manufactured by vulcanizing unvulcanized rubber between a rigid inner mold and a vulcanizing mold disposed on the outer peripheral side of the rigid inner mold. It is an object of the present invention to provide a method and an apparatus for manufacturing a pneumatic tire capable of further improving tire quality by appropriately controlling the tire.

  In order to achieve the above object, a method for producing a pneumatic tire according to the present invention includes disposing an unvulcanized base tire on the outer peripheral surface of a cylindrical metal rigid inner mold that can be divided into a plurality of parts in the circumferential direction. In the vulcanizing mold together with the rigid inner mold, and then vulcanizing the unvulcanized base tire, and an inner peripheral surface of the vulcanizing mold and an outer peripheral surface of the base tire. The unvulcanized rubber is injected into the cavity formed between the tires and the unvulcanized rubber is vulcanized to form a tread portion on the outer peripheral surface of the base tire, and the tread portion is formed on the outer periphery of the base tire. It is characterized by manufacturing a pneumatic tire integrated with a surface.

  The pneumatic tire manufacturing apparatus according to the present invention includes a cylindrical metal rigid inner mold that can be divided into a plurality of circumferential directions in which an unvulcanized base tire is disposed on an outer peripheral surface, and the unvulcanized base tire. A vulcanizing mold disposed inside together with the rigid inner mold, and an unvulcanized cavities formed between an inner peripheral surface of the vulcanizing mold and an outer peripheral surface of the unvulcanized base tire And an injecting machine for injecting rubber, and vulcanizing the unvulcanized base tire, and a tread portion formed by vulcanizing the unvulcanized rubber injected into the cavity is integrated with the outer peripheral surface of the base tire It is made into the structure which made it pneumatic and manufacture a pneumatic tire.

  According to the present invention, an unvulcanized base tire is disposed in a vulcanizing mold together with a rigid inner mold, and formed between the inner peripheral surface of the vulcanizing mold and the outer peripheral surface of the base tire. Since the tread portion is formed by injecting unvulcanized rubber into the cavity, the injected unvulcanized rubber can be spread widely in the cavity. Therefore, it is possible to manufacture a pneumatic tire by controlling the rubber volume to an appropriate amount with high accuracy and integrating the tread portion and the base tire while vulcanizing, while using the rigid inner mold. Accordingly, it is advantageous to avoid the occurrence of a vulcanization failure, and a high-quality tire excellent in tire performance such as uniformity can be manufactured. Further, even a rubber type that is difficult to extrude can be injected and used for forming a tread portion.

  In the present invention, for example, the manufactured pneumatic tire is taken out of the vulcanizing mold together with the rigid inner mold disposed inside the pneumatic tire, and outside the vulcanizing mold. The rigid inner mold is removed from the inside of the pneumatic tire. Thereby, the operation | work which arrange | positions a rigid inner type | mold inside a base tire, and the operation | work which removes a rigid inner type | mold from the inner side of the manufactured pneumatic tire can be performed on the exterior of a vulcanization mold. Therefore, it is not necessary to provide a mechanism for performing these operations in the manufacturing apparatus, which is advantageous for simplifying the manufacturing apparatus.

  When the unvulcanized pedestal tire is placed in the vulcanization mold together with the rigid inner mold, the unvulcanized rubber to be injected is filled into a cylinder in which a plunger of an injection machine is installed. You can also. This makes it possible to quickly inject unvulcanized rubber into the cavity, making it difficult for the unvulcanized rubber to receive an unnecessary heat history.

  The unvulcanized rubber can be injected from the tire side surface of the cavity. Thereby, it becomes easy to reduce the pressure applied to the base tire inward in the radial direction by the injected unvulcanized rubber. Along with this, further improvement in uniformity of the manufactured pneumatic tire can be expected.

  As the unvulcanized rubber to be injected, for example, a rubber composition in which 10 to 200 parts by weight of silica is blended with 100 parts by weight of diene rubber can be used. In this case, for example, a rubber composition containing 1 to 20% by weight of a silane coupling agent based on the content of the silica is used.

BRIEF DESCRIPTION OF THE DRAWINGS It is a whole schematic diagram which illustrates a part of manufacturing apparatus of the pneumatic tire of this invention by tire width direction sectional view. It is explanatory drawing which illustrates the manufacturing apparatus of FIG. 1 by planar view. It is explanatory drawing which illustrates the rigid inner type | mold of FIG. 2 by planar view. It is explanatory drawing which illustrates the state which isolate | separated and divided | segmented the rigid internal type | mold of FIG. 3 by planar view. It is explanatory drawing which illustrates the state which inject | emitted the unvulcanized rubber to the cavity by tire width direction sectional view. It is explanatory drawing which shows the modification of a rigid internal type | mold by planar view. It is explanatory drawing which illustrates the state which has moved the short segment of the rigid internal type | mold of FIG. 6 to the diameter reduction position by planar view. It is explanatory drawing which illustrates the rigid internal type which moves a long segment to a diameter reduction position, and reduces diameter in planar view. It is explanatory drawing which illustrates the process of assembling another rigid internal type | mold. It is explanatory drawing which illustrates the state which has arrange | positioned the base tire on the outer peripheral surface of the rigid inner type | mold of FIG. It is explanatory drawing which illustrates the rigid inner type | mold and stand tire of FIG. 10 by planar view.

  Hereinafter, the manufacturing method and manufacturing apparatus of the pneumatic tire of this invention are demonstrated based on embodiment shown in the figure.

  The pneumatic tire manufacturing apparatus 1 of the present invention illustrated in FIGS. 1 to 2 includes a cylindrical metal rigid inner mold 2 (hereinafter referred to as a rigid inner mold 2) in which an unvulcanized base tire BT is disposed on the outer peripheral surface. ) And a vulcanizing mold 6 in which the base tire BT is disposed together with the rigid inner mold 2, and an injection machine 11.

  The unvulcanized base tire BT refers to a tire in a normal green tire in which there is no rubber in the tread portion TR. Therefore, the unvulcanized base tire BT can be obtained by omitting the tread rubber attaching step in the known green tire molding method.

  As illustrated in FIGS. 3 and 4, the rigid inner mold 2 can be divided into a plurality of parts in the circumferential direction, and a plurality of segments 3 (3A, 3B) divided in the circumferential direction are assembled in a cylindrical shape. It has a structure. Examples of the material of the rigid inner mold 2 include metals such as carbon steel, aluminum, and aluminum alloys. In this embodiment, there are two types of four long segments 3A having a relatively large circumferential length and four short segments 3B having a relatively small circumferential length. Both end surfaces in the circumferential direction of the short segment 3B are parallel in a plan view. The long segments 3A and the short segments 3B are alternately arranged in the circumferential direction.

  Each segment 3A, 3B is attached to a support arm 5 extending radially from the central axis 4. Each segment 3A, 3B, the central shaft 4, and the support arm 5 are separable separately. That is, the rigid inner mold 2 is not a structure that expands and contracts, but is a structure that is separated and divided into respective segments 3 and subdivided. If necessary, the segments 3A and 3B adjacent in the circumferential direction are connected by an appropriate connecting member on the inner peripheral side thereof.

  The rigid inner mold 2 is formed by assembling the segments 3 </ b> A and 3 </ b> B separated from each other into a cylindrical shape and connecting the central shaft 4 and the support arm 5. In the formed rigid inner mold 2, the outer surfaces of the respective segments 3A and 3B are continuously annularly contacted with the range of the tire inner surface corresponding to the tread portion TR of the base tire BT.

  The vulcanizing mold 6 includes a plurality of divided molds 6a divided in the circumferential direction and a pair of upper and lower ring-shaped molds 6b. In this embodiment, the four split molds 6a are assembled in a ring shape. A ring-shaped mold 6b is arranged on the inner peripheral side of the upper and lower end portions of the assembled cylindrical divided mold 6a.

  Each of the split molds 6a moves to the inner peripheral side in the radial direction, abuts against each other, and abuts against the pair of upper and lower ring-shaped molds 6b, whereby the vulcanizing mold 6 is closed. On the other hand, each of the split molds 6a moves to the outer peripheral side in the radial direction, separates from each other and separates from the pair of upper and lower ring molds 6b, whereby the vulcanizing mold 6 is opened.

  The closed mold for vulcanization 6 covers the outer peripheral surface of the base tire BT on which the rigid inner mold 2 is disposed. A cavity 9 is formed between the inner peripheral surface of the vulcanizing mold 6 and the outer peripheral surface of the base tire BT.

  In the vulcanization mold 6, an inner peripheral surface that forms the cavity 9 and an injection path 10 that is connected to the formed cavity 9 are formed. The inner peripheral surface of the vulcanizing mold 2 that forms the cavity 9 has a shape that forms a tread pattern of the pneumatic tire T to be manufactured. One end of the injection path 10 is connected to the injection port of the injection machine 11.

  The other end of the injection path 10 is connected to the position of the inner peripheral surface of the split mold 6a corresponding to the tire side surface side of the cavity 9, for example. Or it connects to the position of the inner peripheral surface of the split mold 6a corresponding to the tread land portion or circumferential groove of the pneumatic tire T to be manufactured. Alternatively, the other end of the injection path 10 is connected to both of these positions. The injection path 10 is preferably branched into a plurality of paths on the way and connected to the cavity 9.

  A heating path 7 connected to a heater 8 is formed in the vulcanizing mold 6. The heater 8 supplies a heating medium such as steam, and the supplied heating medium flows through the heating path 7 to heat the vulcanization mold 6.

  The injection machine 11 includes a cylinder 11a that stores the unvulcanized rubber R while heating it at a predetermined temperature, and a plunger 11b that extrudes the unvulcanized rubber R stored in the cylinder 11a. By advancing the plunger 11b, the unvulcanized rubber R is injected at a predetermined injection pressure. This injection pressure is, for example, 10 MPa to 50 MPa.

  The unvulcanized rubber R has flow characteristics that can be injected and may be any specification that can be vulcanized. For example, natural rubber, diene rubbers such as IR, SBR, BR, butyl rubber, halogenated butyl rubber, EPDM, etc. Various compounding materials such as non-diene rubber, carbon black, oil, anti-aging agent, processing aid, softener, plasticizer, vulcanizing agent, vulcanization accelerator and vulcanization retarder are appropriately blended.

  An example of a procedure of a method for manufacturing a pneumatic tire using the manufacturing apparatus 1 will be described.

  First, the unvulcanized base tire BT is disposed on the outer peripheral surface of the rigid inner mold 2. This step is performed outside the vulcanizing mold 6. For example, the base tire BT is formed by laminating members constituting the unvulcanized base tire BT sequentially on the outer peripheral surface of the rigid inner mold 2, thereby forming the unvulcanized base tire BT on the outer peripheral surface of the rigid inner mold 2. Place. Alternatively, the unvulcanized base tire BT is disposed on the outer peripheral surface of the rigid inner mold 2 by inserting the segment 3 into the inside of the unvulcanized base tire BT that has already been formed with a forming drum or the like and assembling it in a cylindrical shape. . By this step, each segment 3 comes into contact with the inner peripheral surface of the base tire BT and is firmly supported from the inner peripheral side by the rigid inner mold 2.

  Next, the base tire BT is placed in the opened vulcanizing mold 6 together with the rigid inner mold 2. Next, by closing the vulcanizing mold 6, the outer peripheral surface of the base tire BT is covered with the vulcanizing mold 6. Thereby, as illustrated in FIG. 1, a cavity 9 is formed between the inner peripheral surface of the vulcanizing mold 6 and the outer peripheral surface of the base tire BT.

  Next, as illustrated in FIG. 5, unvulcanized rubber R is injected from the injector 11 into the cavity 9 and filled into the cavity 9 through the injection path 10. For example, when placing the base tire BT in the vulcanizing mold 6 together with the rigid inner mold 2, the cylinder 11 a of the injection machine 11 is filled with the unvulcanized rubber R to be injected. In this way, the unvulcanized rubber R can be quickly injected into the cavity 9, so that it is difficult for the unvulcanized rubber R to receive an unnecessary heat history. Accordingly, the unvulcanized rubber R can be injected in a state where the fluidity of the unvulcanized rubber R is not lowered, so that it becomes more and more advantageous to sufficiently spread the unvulcanized rubber R over the entire range of the cavity 9.

  The unvulcanized rubber R filled in the cavity 9 is molded into a predetermined shape by the cavity 9. Then, the injected unvulcanized rubber R and the unvulcanized rubber forming the base tire BT are vulcanized by the vulcanizing mold 6 heated by the heating medium flowing through the heating path 7. The rigid inner mold 2 is also heated as necessary to promote vulcanization of the base tire BT. The rigid inner mold 2 can transfer heat of the vulcanizing mold 6 or can be provided with an independent heating means.

  When the unvulcanized rubber R is vulcanized, a tread portion TR made of the vulcanized rubber is formed on the outer peripheral surface of the base tire BT, and this tread portion TR is vulcanized and bonded to the outer peripheral surface of the base tire BT. And unite. Thereby, the pneumatic tire T is completed.

  Next, the pneumatic tire T is taken out of the vulcanizing mold 6 together with the rigid inner mold 2 disposed inside the pneumatic tire T. Thereafter, the rigid inner mold 2 inside the pneumatic tire T outside the vulcanizing mold 6 is separated into segments 3 and divided and removed from the inside of the pneumatic tire T.

  As described above, in the present invention, the tread is injected by injecting the unvulcanized rubber R into the cavity 9 formed between the inner peripheral surface of the vulcanizing mold 6 and the outer peripheral surface of the unvulcanized base tire BT. Since the portion TR is formed, the injected unvulcanized rubber R can be spread widely in the cavity. For this reason, the tread portion TR is controlled by accurately controlling the rubber volume to an appropriate amount, while using the rigid inner mold 2 that has conventionally been difficult to achieve an appropriate rubber volume and easily causes vulcanization failure. And the pneumatic tire T can be manufactured by integrating the base tire BT while vulcanizing. Therefore, a high-quality pneumatic tire T excellent in tire performance such as uniformity can be manufactured while preventing vulcanization failure.

  Since the unvulcanized rubber R is injected into the cavity 9 while the inner peripheral surface of the tire is supported by the solid rigid inner mold 2, the trouble that the base tire BT is dented inward by the injection pressure of the unvulcanized rubber R is avoided. it can. Accordingly, the injection pressure of the unvulcanized rubber R can be set higher than when the inside of the base tire BT is supported by the vulcanizing bladder. Therefore, there is an advantage that the injection time can be shortened, which contributes to improvement of tire productivity. Further, there is an advantage that the unvulcanized rubber R can be easily spread over the entire range of the cavity 9. Therefore, even a complicated tread pattern is advantageous for molding. These advantages are also advantageous for improving dimensional accuracy.

  When the unvulcanized rubber R is injected from the tire side surface side of the cavity 9 by the injection machine 11, the pressure applied to the base tire BT radially inward by the unvulcanized rubber R can be reduced. Along with this, further improvement in the uniformity of the manufactured pneumatic tire T can be expected.

  Also, in the present invention, unlike the conventional manufacturing method, an excessive force that pushes the green tire toward the outer peripheral side does not act (so-called lift force does not act). Therefore, in the vulcanized tread portion TR, the residual stress resulting from this force is reduced, and improvement in wear resistance and the like can be expected.

  In this embodiment, the work of disposing the rigid inner mold 2 inside the base tire BT and the work of removing the rigid inner mold 2 from the inside of the manufactured pneumatic tire T can be performed outside the vulcanizing mold 6. it can. Therefore, it is not necessary to provide the manufacturing apparatus 1 with a mechanism for performing these operations, which is advantageous for simplifying the manufacturing apparatus 1.

  In the present invention, even a rubber type that is difficult to extrude can be injected and used to form the tread portion TR. For example, in the case of an unvulcanized rubber composition in which 10 to 200 parts by weight of silica is blended with 100 parts by weight of a diene rubber, if a green tire molded member is molded by extrusion, shrinkage with time (shrink) Is large and warps. For example, in this case, in the case of a rubber composition in which a silane coupling agent is blended in an amount of 1 to 20% by weight with respect to the content of silica, such a problem becomes remarkable. For this reason, it has been difficult to use such a rubber compound as a tread rubber.

  However, when the present invention is applied and an unvulcanized rubber composition having such a composition is injected from the injection machine 11 and used as a tread portion, the above-described problems are hardly caused. Therefore, the present invention is very beneficial when an unvulcanized rubber composition having such a composition is employed in the dread portion.

  According to the present invention, another effect that the exothermic property of the rubber is reduced (the rolling resistance of the tire is reduced) is also obtained. As a result of inventor's diligent study, unlike the usual rubber extrusion, when the rubber is injected, since the shear rate by injection is high, the dispersion of compounding agents such as carbon black and silica obtained by normal rubber kneading is further dispersed. It turned out to be good. As a result, it was possible to find an advantage that the rolling resistance of the tire was further reduced.

  Actually, a pneumatic tire manufactured by the manufacturing method of the present invention in which tread rubber is injection-molded using two types of rubber (A rubber and B rubber) in the blending ratio (part by mass) shown in Table 1 as tread rubber ( The rolling resistance was measured for Examples 1 and 2) and pneumatic tires (Conventional Examples 1 and 2) manufactured by a conventional manufacturing method in which tread rubber was extruded. The results are shown in Table 2.

[Rolling resistance]
When the manufactured pneumatic tire is assembled to a wheel with a rim size of 7 × J, the air pressure is 230 kPa, and the test load is 2.94 kN and the speed is 50 km / h on an indoor drum testing machine (drum diameter 1707 mm) in accordance with JIS D4230. The resistance force was measured. The measurement results are indicated by indexes with the conventional examples 1 and 2 as 100 for each rubber type. The smaller the index value, the lower the rolling resistance and the better the fuel efficiency.

  From the results of Table 2, the rolling resistance of Examples 1 and 2 is lower than that of Comparative Examples 1 and 2, respectively, despite the production of tread rubber using an unvulcanized rubber composition of the same composition. I understand.

  The rigid inner mold 2 used in this embodiment is not a structure that expands and contracts, but is a structure that is separately separated, divided, and subdivided into segments 3. However, the structure is not limited to the above embodiment, and various structures are possible. Can be adopted. Moreover, the rigid inner mold 2 having a structure that expands and contracts can also be employed.

  The rigid inner mold 2 illustrated in FIGS. 6 to 8 includes two types of four long segments 3A and four short segments 3B, as in the above-described embodiment. Each segment 3A, 3B is attached to a support arm 5 extending radially from the central axis 4. The support arm 5 is a fluid cylinder and has a rod that moves forward and backward.

  The segments 3 (3A, 3B) arranged in an annular shape around the central axis 4 are arranged in the radial direction (reduced diameter position) by retracting the rod of the support arm 5 from the short segment 3B as illustrated in FIG. 8, the rigid inner mold 2 is reduced in diameter by moving the long segment 3 </ b> A backward in the radial direction (reduced position) by moving the rod of the support arm 5 backward as illustrated in FIG. 8. Become. For example, after moving the short segment 3B to the reduced diameter position, the short segment 3B is removed from the support arm 5, and then the long segment 3A is moved to the reduced diameter position.

  The rigid inner die 2 in the reduced diameter state moves the long segment 3A forward in the radial direction (expanded position) by moving the rod of the support arm 5 forward, and then advances the rod of the support arm 5 in the short segment 3B. The diameter is expanded by moving it radially outward (diameter expansion position). In the rigid inner mold 2 whose diameter has been expanded, the segments 3A and 3B are continuously assembled in a cylindrical shape in the circumferential direction.

  All the short segments 3B can be moved simultaneously or separately. Each of the long segments 3A can be moved simultaneously or separately.

  In the present invention, the rigid inner mold 2 illustrated in FIGS. 9 to 11 can also be used. This rigid inner mold 2 is not a structure that expands and contracts, but is a structure that is separately separated, divided and subdivided into segments 3.

  The rigid inner mold 2 has a cylindrical shape and is composed of segments 3 divided into a plurality in the circumferential direction. Each segment 3 is configured to further divide the cylindrical circumferential surface into two in the width direction.

  Connecting portions 3b are formed on the inner peripheral surfaces of the opposite ends of the segments 3 divided in the width direction. These connecting portions 3b are formed with insertion holes into which connecting members 5c such as bolts and pins are inserted. These insertion holes can be both through holes, or one can be a through hole and the other can be a hole with one end closed.

  When assembling the rigid inner mold 2, the connecting portions 3b of the segments 3 divided in the width direction are brought together. Next, the segment 3 is connected by inserting the connecting member 5c from one connecting portion 3b toward the other connecting portion 3b.

  Next, the support arm 5 extending in the tire radial direction is inserted inside the segment 3, and the fitting portion 5a at the tip of the support arm 5 is fitted into the connecting portions 3b and 3b with which the connecting member 5c communicates. The segment 3 and the support arm 5 are assembled in the same manner. If necessary, the segments 3 adjacent to each other in the circumferential direction are connected by an appropriate connecting member on the inner peripheral side thereof. Finally, the cylindrical rigid inner mold 2 is assembled by engaging the annular holding ring 3c.

  A pre-molded unvulcanized base tire BT is disposed on the outer peripheral surface of the assembled cylindrical rigid inner mold 2. Alternatively, a tire constituent member other than the tread rubber is disposed on the outer peripheral surface of the assembled rigid inner mold 2 to form an unvulcanized base tire BT. The inner peripheral edge 3a of the segment 3 is disposed on the inner peripheral side of the bead portion Tb in contact with the bead portion Tb of the unvulcanized base tire BT.

  After manufacturing the pneumatic tire T using the rigid inner mold 2, the rigid inner mold 2 is removed from the tire T. When the rigid inner mold 2 is removed, a procedure reverse to the procedure described above for assembling the rigid inner mold 2 may be performed. Specifically, after removing the holding ring 3 c from the rigid inner mold 2, the support arm 5 disposed on the inner periphery of the tire T is removed. Next, after disconnecting the connection portions 3b of the segment 3, the segments 3 can be easily disassembled by sliding them alternately as illustrated in FIG. Thereby, the rigid inner mold 2 is removed from the tire T.

  Therefore, the operation of disposing the base tire BT on the outer peripheral surface of the rigid inner mold 2 and the operation of removing the rigid inner mold 2 from the inside of the manufactured pneumatic tire T can be performed outside the vulcanizing mold 10. Therefore, it is advantageous for improving the productivity of the tire T.

DESCRIPTION OF SYMBOLS 1 Manufacturing apparatus 2 Rigid inner type | mold 3 Segment 3A Long segment 3B Short segment 3a Edge part 3b Connection part 3c Holding ring 4 Center axis 5 Support arm 5a Fitting part 5b Shaft part 5c Connection member 6 Vulcanization type | mold 6a Division | segmentation type | mold 6b Ring-shaped mold 7 Heating path 8 Heating machine 9 Cavity 10 Injection path 11 Injection machine 11a Cylinder 11b Plunger BT Stand tire T Pneumatic tire Tb Bead part TR Tread part R Unvulcanized rubber

Claims (8)

  An unvulcanized base tire is disposed on the outer peripheral surface of a cylindrical metal rigid inner mold that can be divided into a plurality of parts in the circumferential direction, and the base tire is disposed in the vulcanization mold together with the rigid inner mold, Next, the unvulcanized base tire is vulcanized, and unvulcanized rubber is injected into a cavity formed between the inner peripheral surface of the vulcanizing mold and the outer peripheral surface of the base tire, The pneumatic tire is manufactured by vulcanizing the unvulcanized rubber to form a tread portion on the outer peripheral surface of the base tire, and integrating the tread portion with the outer peripheral surface of the base tire. A method of manufacturing a pneumatic tire.   The manufactured pneumatic tire is taken out of the vulcanizing mold together with the rigid inner mold disposed inside the pneumatic tire, and the inside of the pneumatic tire is outside the vulcanizing mold. The method for manufacturing a pneumatic tire according to claim 1, wherein the rigid inner mold is removed from the tire.   When the unvulcanized base tire is placed in the vulcanizing mold together with the rigid inner mold, the unvulcanized rubber to be injected is filled in a cylinder in which a plunger of an injection machine is installed. Item 3. A method for producing a pneumatic tire according to Item 1 or 2.   The method for producing a pneumatic tire according to any one of claims 1 to 3, wherein the unvulcanized rubber is injected from a tire side surface side of the cavity.   The pneumatic tire according to any one of claims 1 to 4, wherein a rubber composition in which 10 to 200 parts by weight of silica is blended with 100 parts by weight of diene rubber is used as the unvulcanized rubber to be injected. Method.   The method for producing a pneumatic tire according to claim 5, wherein a rubber composition containing 1 to 20% by weight of a silane coupling agent is used with respect to the content of the silica.   A cylindrical metal rigid inner mold that can be divided into a plurality of circumferentially arranged uncured base tires on the outer peripheral surface, and a unrolled tire that is placed inside together with the rigid inner mold. A mold for vulcanization, and an injection machine for injecting unvulcanized rubber into a cavity formed between an inner circumferential surface of the vulcanization mold and an outer circumferential surface of the unvulcanized base tire, In addition to vulcanizing the unvulcanized base tire, a tread portion formed by vulcanizing the unvulcanized rubber injected into the cavity is integrated with the outer peripheral surface of the base tire to produce a pneumatic tire. A pneumatic tire manufacturing apparatus characterized by the above.   The manufacturing of the pneumatic tire according to claim 7, wherein the rigid inner mold is removed from the inside of the pneumatic tire after being taken out of the vulcanizing mold together with the manufactured pneumatic tire. apparatus.

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