JP6724336B2 - Pneumatic tire vulcanizing apparatus and method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a vulcanizing apparatus and method for a pneumatic tire, and more specifically, it reliably removes unnecessary air existing between a vulcanizing bladder and a green tire to improve the quality of a vulcanized tire. The present invention also relates to a pneumatic tire vulcanizing apparatus and method capable of suppressing damage to a vulcanizing bladder.

In a tire vulcanization process, a green tire is installed in a tire mold. Then, the vulcanization bladder inserted into the inside of the green tire is expanded by a heating medium and a pressure medium, and the green tire is heated at a predetermined temperature in a closed tire mold and pressed at a predetermined pressure to vulcanize. ..

In this vulcanization process, if unnecessary air remains between the vulcanization bladder and the green tire, the green tire may not be sufficiently pressed and the vulcanized tire may have a poor appearance. .. Therefore, it is necessary to remove unnecessary air from between the vulcanization bladder and the green tire. Therefore, in the conventional vulcanization method, for example, an air vent groove is formed on the outer surface of the vulcanization bladder (see Patent Document 1). Then, with the expanded vulcanization bladder, unnecessary air existing between the vulcanization bladder and the green tire is pushed out through the air vent groove to be removed from between the two.

However, when the vulcanization bladder is expanded, the air vent groove formed on the outer surface becomes shallow, and it becomes difficult to remove unnecessary air. Therefore, if the air vent groove is simply deepened, the rubber thickness of the groove portion becomes thin, so that the vulcanization bladder is easily damaged and the durability deteriorates. To deepen the air vent groove and ensure the durability of the vulcanization bladder, the rubber thickness of the vulcanization bladder should be increased overall, but then extra energy is required to expand the vulcanization bladder. Moreover, there arises a problem that the thermal conductivity deteriorates. Since a vicious cycle of such defects occurs in measures to form grooves etc. on the outer surface of the vulcanization bladder, unnecessary air existing between the vulcanization bladder and the green tire is surely removed, and the vulcanization bladder is damaged. There is room for improvement in order to suppress this.

JP, 2012-45779, A

An object of the present invention is to reliably remove unnecessary air existing between the vulcanization bladder and the green tire, improve the quality of the vulcanized tire, and suppress damage to the vulcanization bladder. An object is to provide a vulcanization apparatus and method for a filled tire.

To achieve the above object, the pneumatic tire vulcanizing apparatus of the present invention comprises a tubular vulcanizing bladder, a central mechanism for vertically inserting the vulcanizing bladder, and the vulcanizing bladder supported by the central mechanism. An upper holding part and a lower holding part respectively holding the upper and lower edge parts of the, and an injection port for injecting a heating medium and a pressurizing medium into the vulcanizing bladder, which is laterally placed inside the tire mold. In a vulcanizing apparatus for a pneumatic tire configured to inflate and expand the heating medium and the pressure medium into the vulcanizing bladder inserted in a tire, a vulcanizing bladder having a suction device for sucking air, the tire after the mold is ready to air said outer surface and said inner surface is sucked by the suction device are in close contact between said vulcanization bladder of the outer surface at the stage of being opened type inner surface of said green tire, wherein The heating medium and the pressurizing medium are injected and expanded at the stage where the tire mold is closed and clamped by the vulcanizing bladder, and the inner surface of the green tire is pressed and heated. To do.

The pneumatic tire vulcanizing method of the present invention comprises an upper holding portion and a lower holding portion arranged vertically with a central mechanism for vertically inserting a tubular vulcanizing bladder into the vulcanizing bladder. In the vulcanization method of the pneumatic tire, which holds the upper and lower edges, respectively, injects a heating medium and a pressure medium into the vulcanization bladder inserted in the green tire laterally placed inside the tire mold to expand the pneumatic tire. , by sucking air between the inner surface of the outer surface and the green tire of the tire mold the vulcanization bladder at the stage that opens type, after the state of close contact with the outer surface and the inner surface, the When the tire mold is closed and the mold is clamped, the heating medium and the pressure medium are injected into the vulcanization bladder to expand the vulcanization bladder to press and heat the inner surface of the green tire.

According to the present invention, before injecting the heating medium and the pressurizing medium into the vulcanizing bladder to expand the vulcanizing bladder, the outer surface of the vulcanizing bladder and the green tire inserted in the green tire laterally placed inside the tire mold. The air between the inner surface and the inner surface is sucked to bring the outer surface and the inner surface into close contact with each other. Therefore, it becomes possible to reliably remove the unnecessary air existing between the outer surface of the vulcanization bladder and the inner surface of the green tire. Along with this, the expanded vulcanization bladder can sufficiently press and heat the inner surface of the green tire, which is advantageous for improving the quality of the vulcanized tire. It is not necessary to inflate the vulcanization bladder excessively for the purpose of removing unnecessary air, and since it is not necessary to form deep grooves on the outer surface of the vulcanization bladder, damage to the vulcanization bladder repeatedly used. It is advantageous to suppress.

It is explanatory drawing which illustrates the outline|summary of the vulcanization apparatus of the pneumatic tire of this invention which is open type by a longitudinal cross-sectional view. It is explanatory drawing which illustrates the state which is drawing in the air between the outer surface of the vulcanization bladder of FIG. 1 and the inner surface of the green tire by a longitudinal cross-sectional view. FIG. 3 is an explanatory view illustrating a state in which the green tire in FIG. 2 is closed and vulcanized in a vertical sectional view. It is explanatory drawing which illustrates the state which has inject|poured air between the outer surface of a vulcanization bladder and the inner surface of the vulcanized tire by a longitudinal cross-sectional view.

Hereinafter, a pneumatic tire vulcanizing apparatus and method according to the present invention will be described based on the embodiments shown in the drawings.

A pneumatic tire vulcanizing apparatus 1 of the present invention illustrated in FIG. 1 (hereinafter referred to as vulcanizing apparatus 1) is provided with a tire mold 11 corresponding to a green tire G to be vulcanized. In this embodiment, the tire mold 11 includes an annular sector 11a divided into a plurality of pieces in the circumferential direction, an annular upper side plate 11b, and an annular lower side plate 11c. The upper side plate 11b and the lower side plate 11c respectively have an annular upper bead ring 12a and an annular lower bead ring 12b.

The upper side plate 11b is fixed to the elevating plate 14. The lower side plate 11c is fixed to the bottom plate 16.

A segment 15 is attached to the outer peripheral surface of each sector 11a. Each segment 15 is suspended from the elevating plate 14 so as to be slidable in the horizontal direction. A container ring 13 is arranged on the outer peripheral side of these segments 15. The outer peripheral inclined surface of the segment 15 and the inner peripheral inclined surface of the container ring 13 are slidably engaged. The lifting plate 14 and the container ring 13 move up and down by a hydraulic cylinder or the like. As the container ring 13 moves up and down with respect to the segment 15, the segment 15 slides in the horizontal direction.

The vulcanization device 1 includes a rubber-made tubular vulcanization bladder 2 and a central mechanism 4 for holding the vulcanization bladder 2. A center post 4a, which constitutes the center mechanism 4, is vertically inserted through the vulcanization bladder 2. The upper edge portion 3a and the lower edge portion 3b of the vulcanization bladder 2 are held by a disc-shaped upper holding portion 5a and a lower holding portion 5b attached to the central mechanism 4, respectively.

An injection port 6 arranged inside the vulcanization bladder 2 is provided at a position on the outer peripheral side of the center post 4a. The inlet 6 is connected to the injection line 6L extending downward through the central mechanism 4. The heating medium M1 and the pressurizing medium M2 are injected into the vulcanization bladder 2 through the injection port 6. The heating medium M1 has a higher temperature than the pressurizing medium M2, and for example, steam or the like is used. The pressurizing medium M2 has a higher pressure and a larger specific gravity than the heating medium M1, and for example, an inert gas such as nitrogen gas is used.

It is preferable to provide a plurality of inlets 6 at intervals in the circumferential direction. The heating medium M1 and the pressurizing medium M2 may be provided with separate injection ports 6 and injection lines 6L. The central mechanism 4 is also provided with a discharge port and a discharge line for discharging the fluid (the heating medium M1 and the pressurizing medium M2) inside the vulcanization bladder 2 to the outside.

The center post 4a has a through passage 7 extending vertically. A suction device 9 and an injecting device 10 are connected to the through passage 7 directly or indirectly via another pipe. The suction device 9 is a device that sucks air and uses, for example, a vacuum pump. The injector 10 is a device that sends air and ejects it, and uses, for example, an air compressor.

The vulcanizing apparatus 1 further includes a lid member 8 which is airtightly fixed to the upper mold bead ring 12a and arranged above the upper holding portion 5a. The lid member 8 may be provided separately from the upper die bead ring 12a, or the upper bead ring 12a may be provided with the lid member 8 in advance. As will be described later, the lid member 8 is moved downward as the lifting plate 14 is moved downward, so that the tire upper space S is formed between the lid member 8 and the upper holding portion 5a.

Then, the suction device 9 and the injection device 10 can communicate with the tire upper space S through the through passage 7. A switching valve 7a is arranged between the suction device 9 and the injection device 10 and the tire upper space S. By operation of the switching valve 7a, a state in which one of the suction machine 9 and the injection machine 10 communicates with the tire upper space S, or a state in which both the suction machine 9 and the injection machine 10 do not communicate with the tire upper space S is selected. It is designed to be

To vulcanize the green tire G using this vulcanizing apparatus 1, as shown in FIG. 1, the lower bead portion of the green tire G is attached to the lower bead ring 12b with the mold 11 opened. The green tire G is placed on the upper side and placed horizontally. Next, as illustrated in FIG. 2, the elevating plate 14 is moved downward to bring the upper bead ring 12a into contact with the upper bead portion of the green tire G. As a result, the upper bead portion and the lower bead portion of the green tire G are brought into air-tight contact with the upper bead ring 12a and the lower bead ring 12b, respectively.

In this state, the tire upper space S is formed by being sandwiched by the lid member 8 and the upper holding portion 5a. Then, the outer space 2a of the vulcanization bladder 2 and the inner surface Ga of the green tire G and the upper space S of the tire communicate with each other to form a closed space. Therefore, by operating the suction device 9, unnecessary air A existing between the outer surface 2a of the vulcanization bladder 2 and the inner surface Ga of the green tire G is sucked through the tire upper space S and the through passage 7 and vulcanized. Discharge to the outside of the device 1. As a result, the outer surface 2a of the vulcanization bladder 2 is brought into close contact with the inner surface Ga of the green tire G.

Then, the elevating plate 14 is moved downward until the respective segments 15 are placed on the bottom plate 16. As a result, the upper side portion and the lower side portion of the green tire G are brought into contact with the upper side plate 11b and the lower side plate 11c, respectively.

Next, the container ring 13 is moved downward with respect to the segment 15 to slide the segment 15 in the horizontal direction. As a result, each sector 11a moves toward the center post 4a and is assembled in an annular shape, and the mold 11 is closed and clamped. In FIG. 3, the mold 11 is closed and clamped.

Next, the heating medium M1 is injected into the vulcanization bladder 2 through the injection port 6 to have a predetermined initial internal pressure P1, and the vulcanization bladder 2 is expanded and heated. The inner surface Ga of the green tire G is pressed by the expanded vulcanization bladder 2, and the green tire G is pressed against the mold 11 to some extent.

After finished injecting the heating medium M1 to vulcanization bladder 2 after a predetermined time elapses, as illustrated in FIG. 3, is injected from the injection port 6 a pressurized medium M2 to the vulcanization bladder 2, the vulcanization bladder 2 The internal pressure P is increased to a predetermined value and further expanded. As a result, the inner surface Ga of the green tire G is further strongly pressed by the expanded vulcanization bladder 2, and the green tire G is strongly pressed against the mold 11. By maintaining this state for a predetermined time, the vulcanization of the green tire G is completed and the tire T is manufactured.

As described above, before injecting the heating medium M1 and the pressurizing medium M2 into the vulcanization bladder 2 and expanding the vulcanization bladder 2, the air A between the outer surface 2a of the vulcanization bladder 2 and the inner surface Ga of the green tire G is sucked. By bringing the outer surface 2a and the inner surface Ga into close contact with each other, unnecessary air A existing between the outer surface 2a and the inner surface Ga can be reliably removed. The suction of the air A is performed before the heating medium M1 is injected into the vulcanization bladder 2 in order to reach the predetermined initial internal pressure P1.

According to the present invention, since the unnecessary air A does not exist, the expanded vulcanization bladder 2 can heat the inner surface Ga of the green tire G while sufficiently pressing it. Therefore, the vulcanized tire T is less likely to suffer vulcanization failure, which is advantageous for improving tire quality.

Further, there is also an advantage that it is not necessary to expand the vulcanization bladder 2 excessively for the purpose of removing the unnecessary air A. Further, there is an advantage that it is not necessary to form a deep groove or the like on the outer surface 2a of the vulcanization bladder 2. Since the vulcanization bladder 2 is repeatedly used after being expanded and contracted at a high temperature, these advantages are very advantageous in suppressing damage to the vulcanization bladder 2.

When the vulcanization of the green tire G is completed and the tire T is manufactured, the container ring 13 is moved upward as illustrated in FIG. As a result, each sector 11a is moved backward with respect to the center post 4a to release the mold clamping. Then, the lift plate 14 is moved upward to open the mold 11.

At this time, the outer surface 2a of the vulcanized bladder 2 is in close contact with the inner surface Ta of the vulcanized tire T. Therefore, conventionally, the fluid (heating medium and pressurizing medium) inside the vulcanization bladder 2 is forcibly sucked and discharged to the outside, so that the vulcanization bladder 2 is in a contracted state. The outer surface 2a was peeled off from the inner surface Ta of the tire T.

However, in order to peel off the outer surface 2a of the vulcanized bladder 2 that is in close contact with the inner surface Ta of the tire T, it is necessary to contract the vulcanized bladder 2 with a considerable suction force. Further, at the moment when the outer surface 2a is peeled off from the inner surface Ta, the bladder 2 is rapidly contracted and deformed. As a result, a large load is applied to the vulcanization bladder 2 and it is easily damaged.

Therefore, in this vulcanizing apparatus 1, as illustrated in FIG. 4, the injector 10 is operated to pass between the outer surface 2a of the vulcanizing bladder 2 and the inner surface Ta of the tire T through the tire upper space S and the through passage 7. Inject air A. As a result, the outer surface 2a of the vulcanization bladder 2 is separated from the inner surface Ta of the tire T. When injecting the air A, if the inside of the vulcanization bladder 2 is communicated with the outside through the discharge line, the outer surface 2a is easily separated from the inner surface Ta.

Then, after the outer surface 2a of the vulcanization bladder 2 is peeled from the inner surface Ta of the tire T, the fluid inside the vulcanization bladder 2 is forcibly sucked and discharged to the outside, whereby the vulcanization bladder 2 Contract. After contracting the vulcanization bladder 2, the tire T is extracted from the vulcanization bladder 2 and taken out from the vulcanization device 1.

By thus injecting the air A and peeling the outer surface 2a from the inner surface Ta, it is not necessary to contract the vulcanization bladder 2 with a considerable suction force as in the conventional case. Further, the vulcanization bladder 2 does not contract and deform suddenly at the moment when the outer surface 2a is peeled off from the inner surface Ta. The load generated on the vulcanization bladder 2 is reduced, it is less likely to be damaged, and the durability is improved.

As the load generated on the vulcanization bladder 2 becomes smaller, the rubber thickness of the vulcanization bladder 2 can be made thinner. This can also be expected to shorten the vulcanization time.

In this embodiment, the suction device 9 and the injector 10 are configured to communicate with the tire upper space S through the through passage 7 formed in the center post 4a, but the through passage 7 may be provided at another position. .. For example, it is possible to use the through passage 7 that penetrates the lid member 8 and extends upward.

When the through passage 7 is provided in the center post 4a as in this embodiment, there is an advantage that it is not necessary to prepare a special member for providing the through passage 7, and airtightness can be easily ensured. The injector 10 can be optionally provided.

By applying the present invention, it is possible to use the vulcanization bladder 2 having no air vent groove on the outer surface 2a, but it is also possible to use the vulcanization bladder 2 having the air vent groove as in the prior art. In that case, the air vent groove can be made shallower than before.

1 Vulcanizing Device 2 Vulcanizing Bladder 2a Outer Surface 3a Upper Edge 3b Lower Edge 4 Center Mechanism 4a Center Post 5a Upper Holding 5b Lower Holding 6 Injection Port 6L Injection Line 7 Through Path 7a Switching Valve 8 Lid 9 Suction Machine 10 Injection machine 11 Tire mold 11a Sector 11b Upper side plate 11c Lower side plate 12a Upper bead ring 12b Lower bead ring 13 Container ring 14 Lift plate 15 Segment 16 Bottom plate G Green tire Ga Inner surface T Manufactured by vulcanization Tire Ta Inner surface S Tire upper space M1 Heating medium M2 Pressurizing medium

Claims (8)

A tubular vulcanization bladder, a central mechanism that vertically inserts the vulcanization bladder, an upper holding portion and a lower holding portion that are supported by the central mechanism and respectively hold the upper and lower edges of the vulcanization bladder, An injection port for injecting a heating medium and a pressurizing medium into the vulcanization bladder, and the heating medium and the vulcanization bladder inserted in a green tire laterally placed inside a tire mold. In a vulcanizing device for a pneumatic tire configured to expand by injecting a pressure medium,
Having a suction device for sucking air, air between the outer surface of the vulcanizing bladder and the inner surface of the green tire is sucked by the suction device at the stage when the tire mold is open, and the outer surface and the after the state in which the inner surface are in close contact, by the vulcanization bladders said heating medium and said pressurizing medium at the stage of mold clamping and closed the tire mold is expanded is injected, the inner surface of the green tire A vulcanizing apparatus for a pneumatic tire, which is configured to be pressed and heated. It has a lid member arranged at the upper end of the laterally placed green tire, the tire upper space sandwiched by the lid member and the upper holding portion, the outer surface of the vulcanization bladder and the green tire. The vulcanization device for a pneumatic tire according to claim 1, wherein a closed space is formed by communicating with the inner surface and the air is sucked by the suction device through the tire upper space. .. The vulcanization of a pneumatic tire according to claim 2, wherein a center post that constitutes the central mechanism has a vertically extending through passage, and the tire upper space and the suction device are connected through the through passage. apparatus. An injecting machine for injecting air, wherein air is injected by the injecting machine between the inner surface of the tire manufactured by vulcanizing the green tire and the outer surface of the vulcanizing bladder, and the outer surface of the vulcanizing bladder In a state of being peeled from the inner surface of the manufactured tire, the vulcanized bladder is contracted, and the manufactured tire is extracted from the contracted vulcanized bladder. The pneumatic tire vulcanizing apparatus described in 1. The upper holding portion and the lower holding portion, which are vertically spaced with respect to the central mechanism for vertically inserting the tubular vulcanizing bladder, respectively hold the upper and lower edges of the vulcanizing bladder, and In a vulcanizing method of a pneumatic tire in which a heating medium and a pressurizing medium are injected and expanded into the vulcanizing bladder inserted in a green tire laterally placed inside,
By sucking air between the outer surface of the vulcanization bladder and the inner surface of the green tire in a stage where the tire mold is open , the outer surface and the inner surface are brought into close contact with each other, and then the tire A pneumatic tire characterized by injecting the heating medium and the pressurizing medium into the vulcanization bladder at the stage where the mold is closed and clamped to expand and press the inner surface of the green tire and heat the green tire. Vulcanization method. A lid member is arranged at an upper end portion of the horizontally placed green tire, a tire upper space sandwiched by the lid member and the upper holding portion, an outer surface of the vulcanization bladder and an inner surface of the green tire. The method for vulcanizing a pneumatic tire according to claim 5, wherein the air is sucked through the upper space of the tire by forming a closed space by communicating the space between the two. The vulcanization method for a pneumatic tire according to claim 6, wherein a through passage that extends vertically to a center post that constitutes the central mechanism is connected to the tire upper space, and the air is sucked through the through passage. Air is injected between the inner surface of the tire manufactured by vulcanizing the green tire and the outer surface of the vulcanizing bladder, and the outer surface of the vulcanizing bladder is peeled from the inner surface of the manufactured tire. After that, the method for vulcanizing a pneumatic tire according to claim 5, wherein the vulcanized bladder is contracted, and the manufactured tire is extracted from the contracted vulcanized bladder.

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