KR101655265B1 - Method Of Designing Cure Bladder For Tire - Google Patents

Abstract

The present invention relates to a method of designing a vulcanized bladder for a tire, comprising: a first designing step of arbitrarily designing a pre-expansion thickness of each part of the bladder; Calculating a thickness shrinkage ratio of each portion of the bladder before and after expansion of the bladder, which is designed in the first stage, through a process of vulcanizing the green tire using the first designed bladder; And the thickness of each portion of the pre-expansion braid is compensated by reflecting the thickness shrinkage ratio of each portion before and after the expansion, which is calculated for the first designed breath, so that the target thickness of each portion of the expanded braid is uniformized It is possible to prevent unevenness in the heat transfer inside the tire caused by uneven thickness expansion of each portion of the brake, to improve the quality of the vulcanization inside the tire, The expansion thickness of the expanded bladder at high temperature and high pressure can be uniformly controlled to improve the productivity of the bladder by improving the life span of the bladder.

Description

{Method Of Designing Cure Bladder For Tire}

The present invention relates to a method of designing a vulcanized tire for a tire, and more particularly, to a method of designing a vulcanized tire for a tire by using a vulcanized rubber bladder so that the bladder can be inflated to have a uniform thickness for each part during tire vulcanization.

As is well known, as is well known, the tire manufacturing process includes a refining process in which a raw material, that is, a compound having specific physical properties is mixed by mixing natural rubber, synthetic rubber, and chemical materials, , The molding process in which each semi-finished product is molded and molded into a green case shape close to the finished product tire, and a vulcanizing process in which the molded green case is placed in a vulcanizer and vulcanized.

In the above-described vulcanization process, the green tire completed in the molding process is inserted between the vulcanization mold of the vulcanizer and the bladder, and then a high-temperature and high-pressure heat medium, i.e., steam is supplied into the bladder and a high temperature heat source is applied to the vulcanization mold, The finished product tires, which are thermosetting elastomers, are completed through a vulcanization reaction.

Breda is made of a single rubber material of butyl type which is easy to shrink and expand. It is expanded to come into contact with the inner surface of the green tire by the steam of high temperature and high pressure inside the vulcanizer, At the same time, the pressure is transmitted to the vulcanized mold to compress the resin.

At this time, the center portion of the expanded bladder comes into contact with the inner center portion of the green tire, and the outer surface of the expanded bladder comes into contact with the inner shoulder portion, the side wall portion and the bead portion of the green tire, .

However, when Breda is expanded and supplied with a high-temperature, high-pressure vulcanizing heat source medium, the thickness of each portion of the breather expands or contracts according to the internal structure of the tire, and in the actual vulcanization reaction, It is disadvantageous in terms of uniform heat source supply of the inner wall of the tire because it is deformed with a different thickness and has a disadvantage in that the lifetime of the bladder due to the difference in outer appearance of the inner surface of the tire and the difference in thickness of the expanded bladder is shortened according to the actual thickness of the expanded bladder.

Korean Patent Publication No. 10-2006-0053219 (published on May 19, 2006) Korean Patent Publication No. 10-2004-0036836 (published on May 03, 2004)

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and to provide a tire vulcanizer which can uniformly heat and pressurize the inner wall of a tire by using a vulcanized rubber bladder, And to provide a method of designing a vulcanized bladder for a tire which is capable of preventing appearance failure and reduction in the life of the bladder.

In order to accomplish the above object, the present invention provides a method for designing a vulcanized bread in which a green tire is inserted into a vulcanizing machine provided with a vulcanizing mold, and the green tire is expanded in a green tire by using a heating medium to thermally press- A first design step of designing the pre-expansion thickness of each part of the breader to be arbitrarily constant; Calculating a thickness shrinkage ratio of each portion of the bladder before and after expansion of the bladder, which is designed in the first stage, through a process of vulcanizing the green tire using the first designed bladder; And a second complementary design to compensate the thickness of each part of the pre-expansion bladder by reflecting the thickness shrinkage ratio of each part before and after the calculated expansion of the first designed bladder so that the target thickness of the expanded bladder becomes uniform during the vulcanization The method comprising the steps of:

의 수학식을 이용해 산출할 수 있다. 여기서, R은 상기 1차 설계된 브레다의 팽창 전후의 각 부위별 수축률이고, T2는 2차 설계된 브레다의 팽창후 목표 두께이다.Here, the pre-expansion pre-expansion thickness (T1) of the secondarily designed Breda is

Can be calculated using the following equation. Here, R is a shrinkage ratio of each part before and after expansion of the first designed bladder, and T2 is a target thickness after secondarily designed bladder expansion.

의 수학식을 이용해 산출할 수 있다. 여기서, t1은 1차 설계된 브레다의 팽창전 각 부위별 두께이고, t2는 1차 설계된 브레다의 팽창후 각 부위별 두께이다.The shrinkage ratio (R) of each part before and after expansion of the first designed Breda is

Can be calculated using the following equation. Here, t1 is the thickness of the pre-inflated portion of the first designed Breda, and t2 is the thickness of each portion after the first designed Breda's inflation.

의 수학식을 이용해 산출할 수 있다. 여기서, S1은 1차 설계된 브레다의 팽창전 각 부위별 단면적이고, S2는 상기 1차 설계된 브레다의 팽창후 각 부위별 단면적이며, V1은 1차 설계된 브레다의 팽창전 각 부위별 체적이다.The thickness (t2) of each part after the expansion of the first designed Breda is

Can be calculated using the following equation. Here, S1 is the cross sectional area of the pre-inflated portion of the first designed Breda, S2 is the sectional area of each portion after the inflation of the first designed Breda, and V1 is the volume of the pre-inflated portion of the first designed Breda.

The sectional area (S2) of each part after the expansion of the primary designed Breda forms the dividing marks dividing the sectional area (S1) of the primary designed Breda before expansion into square lattice forms, It is possible to calculate the cross sectional area of each part projected by the respective division marks on the inner circumferential surface of the vulcanized tire by expanding the bladder.

Here, the dividing marks may be formed on the outer circumferential surface of the first designed bladder by a predetermined depth or may be formed by applying silicon.

According to the method for designing a vulcanized tire for a tire according to the present invention, the thickness of each portion of the bladder before expansion is arbitrarily designed in a random manner, and the green tire is vulcanized by applying the first designed bladder, The thickness shrinkage ratio of each portion before and after the expansion of the bladder is calculated and the thickness shrinkage ratio of each portion before and after the expansion calculated in the first designed bladder is compensated to compensate the thickness of each portion of the bladder before the expansion, By the second complementary design so that the target thickness of each part of the expanded bladder becomes uniform, the thickness of each part of the bladder becomes uneven when the vulva expands, thereby preventing uneven heat transfer inside the tire and improving the quality of the vulcanization inside the tire And it is possible to uniformly control the expansion thickness of the expanded bladder at high temperature and high pressure to improve the life of the bladder. By an effect that can increase the productivity.

FIG. 1 is a flowchart illustrating a vulcanized blade design process for a tire according to an embodiment of the present invention.
2 is a side cross-sectional view of a vulcanizer showing a state in which a green tire is vulcanized in a vulcanized vulcanizer.
FIG. 3 is a perspective view showing the vulva's expanded counterpart of the first designed Breda in FIG. 2; FIG.
FIG. 4 is a partially cutaway perspective view of a vulcanized tire showing a state in which a cross-sectional area of each portion of the vulcanized bladder of FIG. 3 is projected. FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same or similar components are denoted by the same reference numerals throughout the specification.

FIG. 1 is a flow chart showing a design process of a vulcanized tire for a tire according to an embodiment of the present invention, and FIG. 2 is a side sectional view of a vulcanizer showing a state where a green tire is vulcanized in a vulcanized vulcanizer.

Referring to FIG. 1, the process of designing a vulcanized tire for a tire includes the steps of: a first design step ST10; a shrinkage rate calculation step ST20 before and after expansion; and a second complementary design step ST30. Make sure that the expansion thickness of each part is uniform.

2, an inner space 11 formed by the side vulcanizing mold 11, the lower vulcanizing mold 12, and the upper vulcanizing mold 13 of the vulcanizer 1 provided with the vulcanizing mold 10, The bladder 20 has a uniform expansion thickness in each part in the process of expanding the green tire inside the green tire by thermally pressing the green tire into the vulcanizing mold 10, So that it is possible to prevent the occurrence of a bad appearance on the inner surface of the tire and a reduction in the service life of the bladder 20.

Referring to FIG. 1 again, in the first designing step ST10, the pre-expansion thickness of each portion of the braid 20 is arbitrarily designed to be constant, and the pre-designed bladder 20 is manufactured.

In order to calculate the shrinkage ratio (R) of each part before and after the inflation to be described later on the outer circumferential surface of the first designed and manufactured bladder 20 and reflect it in the second supplementary designing step ST30, 20 to form a dividing mark 21 in the form of a square lattice that divides the sectional area of each pre-expansion portion.

FIG. 3 is a perspective view showing a vulva expanded relative to the first designed bladder in FIG. 2, and FIG. 4 is a partially cutaway perspective view of a vulcanized tire showing a sectional area of each portion of the vulcanized bladder of FIG. 3 projected.

Referring to FIGS. 3 and 4 together with FIG. 1, in the present embodiment, the division marks 21 are formed on the outer peripheral surface of the first designed brake 20 in a predetermined depth The present invention is not necessarily limited to this, and the cross sectional area S2 of each part after inflating the first designed bladder, which is actually expanded on the inner circumferential surface of the vulcanized tire 30 by inflating the first designed bladder 20, It is natural that it is possible to apply a more various modification including the formation of the division mark 21 by applying the silicon so that it can be projected so as to be able to be projected.

Sectional area S1 and thickness t1 of each portion of the pre-expansion bladder 20 and the expansion touched on the inner wall of the vulcanized tire 30 in order to calculate the actual expanded thickness t2 during the vulcanization reaction of the bladder 20, And the cross-sectional area S2 of the bladder 20 that has been used.

Therefore, the above-described dividing marks 21 are formed on the center portion CP located at the central portion in the width direction of the tire and the tread portion, the side portion, the shoulder portion, the side wall portion, And the bead portions are symmetrically divided into six upper and lower side cross sectional areas (A to F, A 'to F'), respectively.

Here, the division marks 21 have horizontal divisional lines 22 formed along the circumferential direction, vertical divisional lines 23 formed in the width direction of the tires so as to intersect perpendicularly with the stroke divisional lines at intervals along the circumferential direction of the tires, So that the sectional areas S1 and S2 of the respective portions before and after the expansion can be calculated on the outer circumferential surface of the first designed bladder 20.

In the shrinkage rate calculation step ST20 for each part of the first designed bladder, the green tire is vulcanized by applying the first designed bladder 20 to the front and rear sides of the bladder 20, The thickness shrinkage ratio (R) for each site is calculated.

The shrinkage ratio (R) of each part before and after expansion of the primary designed bladder 20 can be obtained by the following equation (1).

Here, t1 is the thickness of the pre-inflated portion of the first designed Breda, and t2 is the thickness of each portion after the first designed Breda's inflation.

The thickness t2 of each portion after the expansion of the first designed breader 20 is determined by the volume V1 of each portion before the expansion of the first designed breader 20 and the volume V1 of each portion after the expansion of the first designed breader 20 Can be obtained from the following equation (2) using the same volume (V2).

Here, S1 is a cross-sectional area of the pre-designed bladder 20, and S2 is a cross-sectional area of each part after the first designed bladder 20 is expanded. V1 is a cross sectional area of the first designed bladder 20 It is the volume of each part before swelling.

The cross sectional area S2 of each part after the expansion of the first designed bladder 20 is obtained by expanding the primary designed bladder 20 as described above and by projecting the projection on the inner circumferential surface of the vulcanized tire 30 vulcanized, Can be calculated through the cross sectional area S22 of each part projected onto the vulcanized tire by the mark 31. [

Table 1 below shows the expansion thickness of the bladder 20, which was initially designed using Equations (1) and (2), according to each portion.

location Upper center Lower F E D C B A CP A ' B ' C ' D ' E ' F ' Thickness before expansion 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 Thickness after swelling 3.8 3.7 3.6 3.5 34 3.3 3.2 3.3 3.4 3.5 3.6 3.7 3.8 Shrinkage (%) 24 26 28 30 32 34 36 34 32 30 28 26 24 Thickness% (%) 119 116 113 109 106 103 100 103 106 109 113 116 119

The positions of the respective parts are determined based on the center CP located at the center of the widthwise center line of the tire, the center portion of the vulcanized tire 30, the shoulder portion, (A to F, CP, and A 'to F') are divided by the division mark 21 so that the intervals corresponding to the bead portions are equal to each other at 30 mm equally spaced intervals. The thickness t1 of each part is an actual thickness of the cross sectional area of each part partitioned into a rectangular shape on the dividing mark 21 on the outer wall before the expansion of the first designed breader 20, The star thickness t2 is designed by calculating the cross-sectional area S2 of each portion after inflating the first designed Breda by using the cross-sectional area S22 of each portion projected on the inner wall of the tire, ) Is calculated by the following equation (1) before and after expansion of the first designed breader 20 And the thickness ratio means the distribution ratio of the expanded thickness of each portion set as the reference value of the thickness of the center.

As shown in Table 1, since the expanded thickness of each portion of the first designed bladder 20 is not uniform, the heat source of high temperature and high pressure supplied to the first designed bladder 20 is not uniformly transmitted to the inner wall of the tire, Since the thickness of the expanded primary bladder 20 differs for each region, the strain that affects the durability of the bladder rubber varies depending on the thickness of the expanded bladder portion, thereby shortening the life of the bladder.

Therefore, in the second complementary design stage, the thickness shrinkage ratio (R) of each portion before and after the expansion calculated in the first designed bladder 20 is reflected, and the thickness of each pre-expansion portion of the pre- Design is made so that the target thickness (T2) after expansion of the designed bladder becomes uniform.

Here, the pre-expansion correction thickness T1 of the second-designed Breda can be obtained by the following equation (3).

Here, R is the shrinkage ratio of the first designed bladder before and after the expansion, and T2 is the target thickness after the second designed bladder expansion

In this way, the design stage of Breda is promoted in two stages. In the first stage, expansion and contraction rates of each part of Breda 20 are measured. In the second stage, the expansion and contraction rates of the respective parts are reflected in the pre- It is designed so that the second designed Breda can be uniformly expanded by each part.

location Upper center Lower F E D C B A CP A ' B ' C ' D ' E ' F ' Thickness before expansion 4.6 4.7 4.9 5.0 5.1 5.3 5.5 5.3 5.1 5.0 4.9 4.7 4.6 Thickness after swelling 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 Thickness% (%) 100 100 100 100 100 100 100 100 100 100 100 100 100

Table 2 shows the pre-expansion thickness, the expansion thickness and the thickness ratio of the second-designed Breda. The target thickness (T2) of the second designed Breda after inflation was set to a constant value based on the required center thickness of 3.5 mm according to the use conditions, and based on this, the shrinkage ratio (R) It is possible to obtain the corrected thickness (T1) of each portion before swelling of the bladder.

As described above, by making the target thickness T2 after inflation of the second designed bladder uniform as a whole, it is possible to induce the vulcanization reaction of the green tire to occur uniformly, thereby obtaining the uniform quality of the finished tire.

Accordingly, it is possible to improve the quality of the vulcanization inside the tire by solving the unevenness of the heat transfer inside the tire caused by the nonuniform thickness of each part when the vulda vulcanization expands, and it is possible to improve the quality of the vulcanization inside the tire and to uniformize the expansion thickness of the expanded bladder at high temperature and high pressure So that the life of the bladder can be improved.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but many variations and modifications may be made without departing from the spirit and scope of the invention. And it goes without saying that they belong to the scope of the present invention.

1: Vulcanization machine 10: Vulcanization tool
11: Side vulcanization mold 12: Lower vulcanization mold
13: upper vulcanization mold 20: vulcanized bladder
21: compartment mark 22: horizontal partition line
23: vertical partition line 30: vulcanized tire
31: Projection mark 32: Horizontal partition line
33: Vertical partition lines A to F: Cross sectional area at the upper side
A 'to F': Lower side cross sectional area CP: Center side sectional area
R: Thickness shrinkage
S1: Cross-sectional area of the first designed Breda before expansion
S2: Cross-sectional area of the first designed Breda after expansion
S22: Cross-sectional area of each part projected on the vulcanized tire
t1: Thickness of the first designed Breda before expansion
t2: Thickness of each part after initial expansion of Breda
T1: Correction thickness of each part before Breda's expansion
T2: Target thickness after swelling of second designed Breda
V1: Volume of each part before Breda's expansion designed first
V2; The volume of each part of Breda's second designed swelling before expansion

Claims (6)

A method of designing a vulcanized bladder for inserting a green tire into a vulcanizing machine provided with a vulcanizing mold, expanding the green tire using a heating medium inside the green tire, and thermally pressing the green tire to the vulcanizing mold,

A first design step of designing the pre-expansion thickness of each part of the breader to be the same;
Calculating a thickness shrinkage ratio of each portion of the bladder before and after expansion of the bladder, which is designed in the first stage, by curing the green tire by applying the first designed bladder; And
In order to compensate the thickness of each portion of the pre-expansion bladder by reflecting the thickness shrinkage ratio of each portion before and after the expansion, which is calculated for the pre-designed bladder, the target thickness for each portion of the expanded bladder is designed to be uniform. A complementary design stage,


The cross-sectional area (S2) of each part after the inflation of the first-
Sectional shape S1 of each of the pre-inflated portions of the brake designed in the above-described manner is formed in a square lattice shape, and the primary designed brake is inflated to form the inner circumferential surface of the vulcanized tire by the respective dividing marks Sectional areas of each projected part,

The thickness (t2) of each part after the inflation of the first designed Breda,

Using the following equation,

The shrinkage ratio (R) of each part before and after the swelling of the first designed bladder is,

, ≪ / RTI >

The thickness (T1) of each of the pre-inflation portions of the second-

Wherein the tire vulcanized bladder is produced by using the following equation.

(Where t1 is the thickness of each pre-expanded portion of Breda, t2 is the thickness of each portion after expansion of the first designed Breda, S1 is the cross-sectional area of the first designed Breda's pre- V 1 is the volume of the pre-inflated region of the first designed Breda, R is the shrinkage percentage of the first designed Breda before and after the inflation, and T2 is the inflation rate of the first designed Breda, This is the target thickness of the second designed Breda after inflation.)
delete delete delete delete The method of claim 1,
The compartment marks,
The method for designing a vulcanized bladder for a tire according to claim 1,

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