JP2006231615A - Bladder for tire vulcanization and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bladder for tire vulcanization constituted so as not only to be made usable in the vulcanization of tires having many kinds of sizes in common but also to be reduced in the vulcanization trouble ratio of the tire, and its manufacturing method. <P>SOLUTION: First, the bladder 1 for tire vulcanization, which can be used regardless of the size of the tire, is preliminarily manufactured by molding the clamp parts 1a in the bladder 1 for the tire vulcanization in a vulcanized state and molding the main body part excepting the clamp parts 1a in an unvulanized state. The tire is vulcanized using the bladder 1 for use in the vulcanization of the tire to manufacture the bladder 1 for use in the vulcanization of the tire having the form fitted to the size of the tire. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a tire vulcanizing bladder and a method of manufacturing the same, and more specifically, the tire vulcanization can be used for vulcanizing tires of different sizes, and the outer surface shape is matched with the tire inner surface shape of each size to vulcanize the tire. The present invention relates to a tire vulcanizing bladder and a method of manufacturing the same, which reduce a vulcanization failure rate.

  The vulcanization of a pneumatic tire is usually performed by setting an unvulcanized tire in a vulcanization mold and expanding a rubber vulcanization bladder from the inside of the unvulcanized tire. This is done by pressing the tire against the inner surface of the vulcanizing mold and maintaining this state for heating for a predetermined time.

  Since this tire vulcanizing bladder needs to be prepared for each type and size of the tire, there is a problem that its manufacturing cost increases and its maintenance is complicated. In addition, the outer shape of the bladder may not necessarily match the shape of the inner surface of the tire to be vulcanized, causing a product failure due to a rubber flow failure due to a dimensional deviation between the inner surface of the tire after vulcanization. There was a case.

Conventionally, as a technique for solving the above-described problem and adapting the deformation of the bladder at the time of expansion to the shape of the inner surface of the tire, there is a technique in which the thickness of the bladder is changed (for example, see Patent Document 1). However, this method has a problem that the manufacturing process of the bladder is complicated and the cost is increased.
Japanese Patent Laid-Open No. 2003-231128

  An object of the present invention is to solve the conventional problems as described above, and to enable common use for vulcanization of tires of various sizes and to reduce the vulcanization failure rate of the tires. Another object of the present invention is to provide a tire vulcanizing bladder and a manufacturing method thereof.

  In order to achieve the above object, a tire vulcanizing bladder according to the present invention is disposed inside an unvulcanized tire inserted in a tire vulcanizing mold, and the tire is vulcanized from inside the tire. Inflatable rubber tire vulcanizing bladder that presses against the inner wall of the mold, wherein the clamp portion of the tire vulcanizing bladder is molded in a vulcanized state, and the other expandable / contractible body The gist is that the part was molded into an unvulcanized state.

  The method for manufacturing a tire vulcanizing bladder according to the present invention includes a heating part disposed around a mold forming surface for molding a clamp part of a tire vulcanizing bladder, and a body part excluding the clamp part. A cooling part is arranged around the mold molding surface to be molded to constitute a tire vulcanization bladder molding mold, and after filling the tire vulcanization bladder molding mold with unvulcanized rubber, The gist of the invention is to vulcanize while heating the mold forming surface for forming the clamp part and cooling the mold forming surface for forming the main body part excluding the clamp part.

  According to the present invention, since the clamp portion of the tire vulcanizing bladder is formed in the vulcanized state and the main body portion is formed in the unvulcanized state, the tire vulcanizing bladder is first attached to the unvulcanized tire. At the stage of use for vulcanization, the unvulcanized main body portion swells in accordance with the tire size to be vulcanized, so that it can be used in common for a plurality of types of tires regardless of the tire size.

  At the stage where the initial vulcanization is completed, the main body portion of the tire vulcanizing bladder is vulcanized through the vulcanization, and therefore, it can be repeatedly used for the second and subsequent vulcanizations of the tire of the same size. . Also, at the time of the first vulcanization, the tire vulcanization bladder is formed by freely deforming and conforming to the tire of the target size, so that the shape suitable for the size is maintained and the rubber on the inner surface of the tire is retained. The vulcanization failure rate such as flow failure can be reduced.

  Furthermore, during the second and subsequent vulcanizations, excessive force does not act on the bladder when the tire vulcanization bladder expands, so that the durability of the tire vulcanization bladder can be improved.

  In addition, since a tire vulcanizing bladder suitable for each tire size can be obtained at the time of the first vulcanization, the vulcanization having a desired post-expansion shape can be achieved at low cost without complicating the manufacturing process of the bladder. Allows the production of sulfur bladders.

  Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a half sectional view showing an example of a vulcanizing bladder used in a tire vulcanizer according to an embodiment of the present invention, and FIG. 2 is a vulcanization used in another tire vulcanizer according to an embodiment of the present invention. It is a half sectional view showing an example of the bladder for use.

  In FIG.1 and FIG.2, the clamp parts 1a and 1a for latching to a tire vulcanization metal mold | die are formed in the both ends of the bladder 1 for vulcanization | cure. As illustrated in FIG. 3, the clamp portions 1 a and 1 a are arranged inside the unvulcanized tire 2 in a state in which the distance between the clamp portions 1 a and 1 a is narrow, and are filled from the inside of the vulcanizing bladder 1. The unvulcanized tire 2 is pressed against the inner surface of the vulcanizing mold 3 and vulcanized.

The rubber in the region of the clamp portions 1a and 1a indicated by X in FIGS. 1 and 2 in the tire vulcanizing bladder-1 is formed in a vulcanized state, and Y in FIGS. 1 and 2 excluding the clamp portions 1a and 1a. The rubber | gum of the area | region of the main-body part to expand / contract shown by is shown in the unvulcanized state. Therefore, the rubber constituting the tire vulcanization bladder-1 is formed of a vulcanized portion and a portion in an unvulcanized state.

  As illustrated in FIG. 3, the tire vulcanization bladder 1 formed in this way is mounted in a vulcanization mold 3 and filled therein with a high-temperature pressure medium. As a result, the tire vulcanizing bladder-1 is vulcanized with the main body portion in an expanded and unvulcanized state in close contact with the inner surface of the unvulcanized tire 2, and the unvulcanized tire 2 is also vulcanized at the same time. The product tire is obtained. Thus, when vulcanizing the first unvulcanized tire 2, when the tire vulcanizing bladder-1 expands, the body portion molded in the unvulcanized state is freely free according to the tire size to be vulcanized. Since it swells, it can be used in common for a plurality of types of tires regardless of the tire size.

  When the first unvulcanized tire 2 described above is vulcanized, a release agent is applied between the outer surface of the main body portion of the tire vulcanizing bladder 1 and the inner surface of the unvulcanized tire 2. Make sure that both sides do not adhere.

  As described above, at the stage where the initial vulcanization is completed, the body portion of the tire vulcanization bladder-1 is vulcanized through the vulcanization, and the tire vulcanization bladder-1 is adapted to the tire of the target size. It is molded into. Therefore, it can be repeatedly used as it is for the second and subsequent vulcanizations of the same size tire, and the vulcanized tires using this can suppress the occurrence of vulcanization failure such as poor rubber flow on the inner surface of the tire. Is done. Furthermore, during the second and subsequent vulcanizations, excessive force does not act on the bladder when the tire vulcanization bladder-1 expands, so that the durability of the tire vulcanization bladder-1 can be improved. .

  Below, the manufacturing method of the bladder 1 for tire vulcanization | cure of this invention is demonstrated.

  The bladder for tire vulcanization-1 according to the present invention is manufactured by filling rubber in a mold for bladder molding and heating it for a predetermined time. As shown in FIG. 4, the tire vulcanization bladder-molding mold 4 has a heating part 5 arranged around the mold forming surface for molding the clamp part 1 a of the tire vulcanization bladder-1; The cooling part 6 is arranged around the mold forming surface for molding the main body part excluding the clamp part 1a. Then, after filling the tire vulcanization bladder-molding mold 4 with unvulcanized rubber, the mold molding surface for molding the clamp part 1a is heated, and the body part excluding the clamp part 1a is molded. Vulcanization is performed while cooling the molding surface.

  The heating unit 5 described above is composed of a heating chamber for supplying a heating fluid, and a heating fluid such as a high-temperature steam of about 150 to 230 ° C., preferably about 200 to 210 ° C. is supplied thereto. The cooling unit 6 is composed of a cooling chamber for supplying cooling water, and the temperature in the vicinity of the cooling unit 6 is adjusted to about 50 to 80 ° C., preferably about 70 ° C. In the tire vulcanization bladder-1 thus obtained, a clamp portion 1a cured by vulcanization and an unvulcanized main body portion are formed.

  In the above-described bladder-molding mold 4, in addition to the heating unit 6, other heating means such as electric heating is provided in the vicinity of the molding surface for molding the clamp portion 1a, so that the tire vulcanizing bladder is provided. The vulcanization of the clamp part 1a at -1 can be promoted.

  The tire vulcanization bladder-1 obtained by the above-described bladder molding die 4 is then subjected to vulcanization of the unvulcanized tire 2, and as described above, the main body formed in an unvulcanized state. The portion is vulcanized, and the entire vulcanization of the tire vulcanization bladder-1 is completed, so that the tire vulcanization bladder-1 having a desired shape is obtained. Therefore, the tire vulcanizing bladder-1 made of many different sizes can be manufactured to have a desired shape at a low cost without complicating the manufacturing process.

  As described above, the tire vulcanizing bladder of the present invention and the method for manufacturing the same are formed by vulcanizing the clamp portion of the tire vulcanizing bladder, and by expanding and contracting the main body portion excluding these portions. By forming an unvulcanized state in advance, a tire vulcanizing bladder that can be used regardless of size is manufactured in advance, and using this tire vulcanizing bladder, an unvulcanized tire is vulcanized. , Which produces tire vulcanization bladders that match the size of the tires, and can be used in many different sizes, as well as vulcanization failures such as poor rubber flow on the inner surface of the tire after vulcanization. It does not occur. Furthermore, during the second and subsequent vulcanization of the tire, excessive force does not act on the bladder when the tire vulcanization bladder expands, so that the durability of the tire vulcanization bladder is improved. It can be widely used as an excellent effect from the viewpoint of management.

  A mold forming surface for forming a clamp portion as a mold for bladder molding for manufacturing the cylindrical tire vulcanizing bladder shown in FIG. 1 for vulcanizing a tire (size: 195 / 65R14). A mold was produced in which the temperature around the mold and the temperature of the mold forming surface forming the main body part excluding the clamp part could be adjusted.

  The rubber filled in the mold for molding the bladder is made the same, and the temperature and the vulcanization time of each part of the mold molding surface are made different as shown in Table 1, so that the conventional bladder and the present invention bladder-1, 2 were produced respectively.

For these three types of tire vulcanization bladders, the vulcanization degree of the rubber at the clamp part and the main body part was measured, and the vulcanization degree of the main body part when the vulcanization value of the clamp part was taken as 100%. The values of are shown together in Table 1.

  As shown in Table 1, in the bladders 1 and 2 of the present invention, the vulcanization degree of the main body part was 5% when the vulcanization degree of the clamp part was 100%. It was confirmed that the rubber of the clamp part of 2 was molded in a vulcanized state, whereas the rubber of the main body part was molded in an unvulcanized state.

  Using the bladders 1 and 2 of the present invention in Example 1, a pneumatic tire of size 195 / 65R14 was vulcanized. Vulcanization was performed three times. The outer peripheral surfaces of the bladders 1 and 2 of the present invention after the first vulcanization, the outer peripheral surfaces of the bladders 1 and 2 of the present invention after the second and third vulcanizations, and the The peripheral values of the inner peripheral surface of each tire were measured, and the difference between these values was examined.

  As a result, through the third vulcanization from the first time, no change was found in the peripheral values of the outer peripheral surfaces of the bladders 1 and 2 of the present invention, and in addition, the inner circumference of the tire after the second and third vulcanizations. There was no change in the surface peripheral value. Further, the peripheral values of the outer peripheral surfaces of the bladders 1 and 2 of the present invention coincided with the peripheral values of the inner peripheral surface of the vulcanized tire. This confirmed that the shapes of the bladders 1 and 2 of the present invention were determined by the first vulcanization.

  Using the bladder 1 of the present invention in Example 1, a pneumatic tire of size 175 / 65R14 was vulcanized. Vulcanization was performed three times, and the same investigation as in Example 2 was performed.

  As a result, no change was found in the peripheral value of the outer peripheral surface of the bladder 1 of the present invention through the third vulcanization from the first time. In addition, the peripheral value of the tire after the second and third vulcanizations It was confirmed that it showed the same value as the peripheral value of the inner peripheral surface. Thus, it was confirmed that the bladder 1 of the present invention can be used for vulcanization of tires having different sizes.

Using the conventional bladder in Example 1 and the bladder 1 of the present invention, 10,000 pneumatic tires of size 195 / 65R14 were vulcanized. The inner surface of each tire after vulcanization was observed to check for product failure due to poor rubber flow. The results are shown in Table 2 using an index with the number of product failures in a tire using a conventional bladder as 100. The smaller the value, the lower the product failure rate.

  From the results in Table 2, it can be seen that the tire using the bladder 1 of the present invention has a product failure rate halved compared to the tire using the conventional bladder.

It is a half sectional view showing an example of a bladder for tire vulcanization used for a tire vulcanizer by an embodiment of the present invention. It is a half sectional view showing an example of the bladder for tire vulcanization used for other tire vulcanizers by the embodiment of the present invention. It is sectional drawing which shows the state which vulcanizes a tire using the vulcanization bladder of FIG. It is sectional drawing which shows an example of the metal mold | die for shape | molding the vulcanization bladder of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vulcanizer 1a Clamp part 2 Unvulcanized tire 3 Vulcanization metal mold 4 Heating part 5 Cooling part

Claims (4)

An inflatable and inflatable rubber tire vulcanizer that is disposed inside an unvulcanized tire inserted into a tire vulcanization mold and presses the unvulcanized tire from the inside toward the inner wall of the tire vulcanization mold. In sulfur bladder,
A tire vulcanizing bladder in which a clamp portion of the tire vulcanizing bladder is formed in a vulcanized state and the other expandable / contractable body portion is formed in an unvulcanized state.   The bladder for tire vulcanization according to claim 1, wherein the main body portion is molded into a vulcanized state by being used for vulcanization of an initial unvulcanized tire.   A tire is provided with a heating part arranged around a mold forming surface for forming a clamp part of a tire vulcanizing bladder and a cooling part arranged around a mold forming surface forming a main body part excluding the clamp part. A vulcanization bladder-molding mold is configured, and after filling the tire vulcanization bladder-molding mold with unvulcanized rubber, the mold molding surface for molding the clamp part is heated, A method for manufacturing a bladder for vulcanizing a tire in which vulcanization is performed while cooling a molding surface for molding a main body part excluding a clamp part. The method for manufacturing a tire vulcanizing bladder according to claim 3, wherein the heating unit is a heating chamber for supplying a heating fluid, and the cooling unit is a cooling chamber for supplying cooling water.

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