JP3745876B2 - Internal mold for rubber molding, vulcanizing apparatus and vulcanizing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technique for vulcanizing a rubber molded body molded on the outer surface of an inner mold for rubber molding having a hollow portion.
[0002]
[Prior art]
Conventionally, as the inner mold for rubber molding, a cylindrical mandrel having a hollow portion is usually used. Further, as the vulcanizing apparatus, there is a so-called vulcanizing can which is simply configured so that pressurized steam can be supplied to the vulcanizing space on the outer side of the mandrel through the steam passage in a state where the rubber molded body is accommodated. Are known. Thereby, pressurized steam can be easily introduced into the vulcanization space, and the rubber molded body accommodated in the vulcanization space can be vulcanized.
[0003]
[Problems to be solved by the invention]
According to the above-described conventional vulcanizing apparatus, the rubber molded body is vulcanized by transferring heat by contact with water vapor in order from the outer portion on the outer side laminated on the mandrel. However, the inner part in the vicinity of the mandrel surface of the rubber molded body laminated on the mandrel is placed in a state where it is difficult to vulcanize. As a result, an unvulcanized portion is generated in the inner portion of the rubber molded body, or a portion of the outer portion that is transformed by contact with water vapor is excessively generated, which may cause uneven vulcanization. Therefore, it is conceivable to provide a heating device that allows water vapor to flow through the inner space of the mandrel so that the rubber molded body can be heated from the inner portion. In order to provide circulation piping to circulate, for the convenience of circulating pressurized steam, in many cases complex and expensive equipment is required from the viewpoint of pressure resistance, durability, etc. There has been a demand for a technique that makes it difficult to cause uneven vulcanization of a rubber molded body.
[0004]
Accordingly, an object of the present invention is to provide a technique for performing vulcanization so that unevenness is less likely to occur with a simple and inexpensive configuration in view of the above situation.
[0005]
[Means for Solving the Problems]
In order to achieve this object, a vulcanizing apparatus of the present invention includes a vulcanization space that accommodates a rubber molded body molded on the outer surface of an inner mold for rubber molding having a hollow portion, and pressurized water is contained in the vulcanization space. A vulcanizing apparatus provided with a water vapor flow passage for introducing steam, comprising gas openings that are provided with openings at both ends of the hollow portion, and gas can be discharged outside the hollow portion at one of the openings. The pressurized steam once supplied into the vulcanization space by gas discharge is forced to flow from the other opening to the hollow part to form a steam flow.
In addition, the vulcanization method of the present invention for achieving the above object includes a hollow portion, and includes openings at both ends of the hollow portion, and gas is supplied to one of the openings from the inside of the hollow portion to the outside. Using an inner mold for rubber molding in which a gas discharge path that can be discharged to the outside of the vulcanization space is formed continuously, the pressurized steam once supplied into the vulcanization space is discharged into the other side of the opening by gas discharge. The rubber molded body formed on the inner mold for rubber molding is vulcanized while forcibly flowing into the hollow portion to generate a water vapor flow.
[0006]
[Function and effect]
In other words, the inner mold for rubber molding has a hollow portion, and has openings at both ends of the hollow portion, and a gas discharge path capable of discharging gas from the inside of the hollow portion to one of the openings. If it is configured to be continuous and configured to generate a water vapor flow in the hollow portion, the inner mold for rubber molding is accommodated in a vulcanizer, and a gas discharge path is continuously provided in one of the openings. Thus, the gas inside the inner mold for rubber molding is configured to be discharged out of the hollow portion. Here, considering the factors that have been difficult to vulcanize the inner portion of the conventional rubber molded body, it is considered that the heat of the water vapor is hardly transmitted to the inner space of the inner mold for rubber molding. That is, it is considered that the inner space portion is in a state in which water vapor does not easily enter and air that was initially present in the inner space portion is less likely to be discharged out of the vulcanization space. Therefore, when the present inventors are able to form a steam flow for forcibly circulating the pressurized steam supplied into the vulcanization space into the hollow portion, even with a simple steam flow generator, it is extremely quick. The new knowledge that the said rubber molded object can be heated was acquired. That is, with the above configuration, if the inner mold for rubber molding is housed in a vulcanizer and pressurized steam is introduced into the vulcanizer, the air remaining in the inner mold for rubber molding can be easily added. It is discharged out of the sulfur space and replaced with the pressurized steam, and the pressurized steam in the vulcanizer can flow through the hollow portion. For this reason, the rubber molded body molded on the outer surface of the inner mold for rubber molding receives heat supply from the inner and outer surfaces by pressurized steam, and is easily vulcanized. Therefore, the vulcanization method of the present invention is useful for supplying a rubber molded product having a stable quality.
[0007]
In other words, the above configuration, without providing additional heating means such as heating positively only the inner hollow portion, by effectively utilizing the device for steam heating in between the pressurizing硫空, the rubber molding The rubber molded body can be efficiently heated from the inner cavity side of the inner mold, and the rubber molded body can be vulcanized quickly and uniformly, reducing the time required for vulcanization. It was possible. Therefore, as the vulcanization time is shortened, the amount of heat energy required for vulcanization heating can be greatly reduced, and the energy cost required for vulcanization can be greatly reduced.
Here, since the steam flow generator forcibly distributes the steam supplied into the vulcanization space to the inner space, the steam flow passage into the vulcanization space is effectively used. Thus, compared to providing a heating device for heating the inner space separately, for example, a gas discharge path capable of discharging gas from the hollow portion to the outside of the vulcanization space can be simply connected. It is possible to adopt an extremely simple and inexpensive configuration, and from the standpoint of the equipment configuration, the cost of the vulcanizing equipment can be greatly reduced by making simple modifications to the conventional vulcanizing can. As a result, a rubber molded body to be vulcanized can be provided at a low cost.
[0008]
In order to configure the water vapor flow generating device, for example, the both ends of the inner mold for rubber molding are provided with openings of the hollow portion,
A water vapor flow passage into the vulcanization space is connected to the opening to constitute a water vapor flow generator,
In the vulcanization space, a blower is separately provided, and a water vapor flow generated by the blower is disposed so as to be freely distributed in the opening.
However, if the water vapor flow generating device is configured by continuously connecting a gas discharge path that allows gas to be discharged outside the vulcanization space to one of the openings, Since water vapor or drainage by the water vapor can be discharged to the outside of the vulcanization space according to the difference in pressure inside and outside the vulcanization space, according to the comparative structure, the water vapor flows into the hollow portion. Even if pressure loss must be taken into account, the structure can be configured so that vulcanization can be performed with a simple structure or control, and vulcanization can be performed efficiently without changing the configuration of the conventional vulcanizing apparatus. It is particularly effective to provide a vulcanizing apparatus capable of performing the following.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
As shown in FIG. 1, the vulcanizing apparatus of the present invention includes a hollow portion 1, and includes openings 2 at both ends of the hollow portion 1, and the inside of the hollow portion 1 is provided at one end 2 a of the opening 2. A vulcanizing space 4 is provided in which a gas discharge passage 3 capable of discharging gas from the outside can be connected continuously, and an inner mold M for rubber molding configured to generate a water vapor flow in the hollow portion 2 can be provided. A gas discharge passage 3 is provided so as to be connectable to the one 2a of the opening 2 so that the gas in the hollow portion 1 can be discharged in a state of being provided continuously with the one 2a of the opening 2. .
[0010]
The vulcanization space 4 is formed inside a vulcanization can 5 that is configured to be mounted with a mandrel M as an inner mold for rubber molding, and the vulcanization can 5 includes pressurized steam. Is provided with a water vapor flow passage 6 for injecting water, a drain discharge pipe 7 for discharging the water vapor condensed in the vulcanization space 4, and a gas discharge that can be connected to one side 2a of the opening 2 of the mandrel M. A path 8 is provided.
A rubber molded body 9 is formed by laminating unvulcanized rubber on the outer peripheral surface M1 of the mandrel M, and is embedded in the vulcanized space 4 to introduce pressurized steam, and to the drain discharge pipe 7 and the gas discharge path 8. When the vulcanization operation is performed while discharging drain or water vapor from the gas, the gas discharge path 8 functions as a water vapor flow generator A, and the hollow portion 1 is connected to the one 2a side from the other 2b side of the opening 2. The flow of water vapor is generated, and not only the water vapor heating from the outside of the rubber molded body 9 but also the rubber molded body 9 is easily heated by water vapor from the inside. Can be predicted.
[0011]
The drain discharge pipe 7 and the gas discharge path 8 are configured so that drain can be discharged using a valve V2 different from the valve V1 while appropriately maintaining the water vapor discharge amount by the orifice type valve V1. The vapor pressure is maintained so as to adjust the internal pressure of the sulfur can to a predetermined temperature, and the drain is discharged to maintain the water vapor flow in the hollow portion 1.
[0012]
【Example】
Therefore, vulcanization by the above-described conventional vulcanization method (a vulcanization method using a vulcanization apparatus that simply supplies pressurized steam from the steam passage but cannot discharge gas from the gas discharge passage), The time required for vulcanization of a rubber molded body having a predetermined shape was compared with the vulcanization method using the above-described vulcanizer.
An opening having a diameter of 20 mm is provided at both ends of a mandrel having a diameter of 500 mm and an effective length of 2000 mm, and a rubber molded body in which 50 mm of unvulcanized rubber is laminated within the effective length of the mandrel is provided at 3.5 kf / cm ^2. When the vulcanization test was performed under the condition of 144 ° C., it took 120 minutes to complete the vulcanization according to the conventional vulcanization method, whereas the vulcanization method using the vulcanization apparatus of the present invention was used. It was found that vulcanization could be completed in 75 minutes, and it was possible to perform a quick operation and to reduce the amount of heat supplied and to vulcanize for energy saving.
[Brief description of the drawings]
[Fig. 1] Longitudinal side view of vulcanizer [Explanation of symbols]
1 Hollow part 2 Opening part 8 Gas exhaust passage

Claims (3)

A vulcanizing apparatus comprising a vulcanization space for accommodating a rubber molded body molded on the outer surface of an inner mold for rubber molding having a hollow portion and provided with a steam flow passage for introducing pressurized steam into the vulcanization space. And
Opening portions are provided at both ends of the hollow portion, and one of the opening portions is continuously provided with a gas discharge path capable of discharging gas from the inside of the hollow portion , and once into the vulcanization space by gas discharge. supplied with pressurized steam, vulcanizing apparatus for forming a forced flow in the steam flow into the hollow portion from the other of said openings. Before SL vulcanizer according to claim 1, wherein the gas discharge passage is provided freely connected to one of said openings. A hollow portion is provided, and openings are provided on both ends of the hollow portion, and a gas discharge path is formed in one of the openings so that gas can be discharged from the hollow portion to the outside of the vulcanization space. Using the inner mold for rubber molding, the pressurized steam once supplied into the vulcanization space is forced to flow into the hollow portion from the other of the openings by gas discharge, and a steam flow is generated. A vulcanization method for vulcanizing a rubber molded body formed in an inner mold for rubber molding.

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