KR101694126B1 - Method of Curing Run Flat Tire - Google Patents

Abstract

The present invention relates to a run-flat tire vulcanizing method in which a heat source supplied to an outer temperature supply chain platen and a jacket of a vulcanizing tire vulcanizing process is controlled to differentiate a curing amount of a side portion including a sidewall portion and a vulcanizing quantity of a tread portion, It is possible to ensure the uniformity of the vulcanized product as an end product suitable for the structural characteristics of the run flat tire and to reduce the energy required in the vulcanization process of the run flat tire.

Description

TECHNICAL FIELD The present invention relates to a method of vulcanizing a tire,

The present invention relates to a run-flat tire vulcanizing method, and more particularly, to a run-through tire vulcanizing method in which a reinforcement insert is provided on a side surface portion of a tire including a sidewall portion to increase the uniformity of vulcanization of a run- .

As is well known, the tire vulcanization process means that the green case inserted in the vulcanized mold is heated and pressed so as to have the finished tire shape having a predetermined pattern shape, so that the tensile strength is increased and the elasticity is strong.

The tire vulcanizing process is a process in which the amount of heat required for vulcanization of the green case is supplied, and the vulcanizing heat amount can be made of outside heat and heat resistance (internal temperature and pressure).

Here, the outside heat is supplied from the outside of the green case through a platen and a jacket forming the outer shape of the vulcanizer, and the heat pressure is supplied to the inside of the bladder provided inside the vulcanizer, Lt; / RTI > medium.

Conventionally, in a conventional tire vulcanizing method, a method of adjusting the heat and pressure of a thermo-compression medium supplied through a bladder to a predetermined cure step in a state in which an external heat temperature supplied through a platen and a jacket is kept constant, .

In the tire vulcanization process, the supply of the total amount of the vulcanized heat to the vulcanization step by the heat resistance is about 60 ~ 70% of the total heat source supply, which is the loss of heat through the heat transfer medium made of the butyl rubber and the temperature of the steam used as the heat source medium It is the effect of heat loss due to condensate generation.

During the vulcanization of the tire, the platen, which forms the lower side, directly contacts the upper and lower parts, that is, the shoulder part, the side wall part and the bead part of the green case, and transmits the outside heat. Has been used as a means to directly contact the non-contact side, i.e., the tread, and to transfer the heat to compensate for the insufficient calorie supply.

Conventionally, when the vulcanization time of a tire is generally uniformly applied at a vulcanizing temperature for a tire for a passenger car in an outer temperature range of 170 to 190 ° C, an internal heat source of 5 kg / cm 2 to 14 kg / To 30%, and supplying 15 kg / cm 2 to 30 kg / cm 2 internal heat source / pressure medium for 60% to 85% of the total curing time.

However, Run Flat Tire is a tire made to be able to travel at low speed while maintaining tire shape even when air pressure is leaked due to tire damage due to external influences unlike ordinary passenger car tires.

On the other hand, the run flat tire is characterized in that the thickness of the side portion including the sidewall is thicker than the tire tread portion due to the reinforcing insert, and the relative weight is larger than that of the tire tread portion.

Therefore, the run-flat tire has a side portion including the reinforcing insert which is the least cure reaction site in the vulcanization process (Least Cure Position), which differs from the management standard of the existing tire in the vulcanization process, ), It is necessary to manage the process of vulcanization.

However, in spite of the difference in the structural characteristics of the run-flat tire, the vulcanization of the existing tires is introduced and the vulcanization progresses. Therefore, it is difficult to obtain adequate vulcanization required for the rubber and semi-finished products for each part, It is difficult to secure the uniformity of the light emitting diode.

Korean Registered Patent No. 10-0892397 (Registered Date: April 01, 2009) Korean Registered Patent No. 10-1310149 (registered on September 12, 2013)

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and provide a run flat tire vulcanizing method in which a reinforcing insert is provided on a side surface portion of a tire including a side wall portion to increase the uniformity of vulcanization of a run flat tire having a thickness variation will be.

In order to accomplish the above object, the present invention provides a method of vulcanizing a run-flat tire provided with a reinforcing insert on the inner side of a side portion of the vulcanizing machine, wherein when the green case of the run-flat tire is placed in a vul- So that the uniformity of the vulcanized tire of the run-flat tire can be controlled according to the thickness variation of the side portion and the tread portion.

Here, the outside heat is supplied through a pair of platens constituting upper and lower sides of the vulcanizing machine, a plurality of jackets arranged and connected along the circumferential direction between the platens, It is preferable to maintain the outside heat temperature through the pair of platens constantly and to vary the outside heat temperature through the jackets corresponding to the tread portion of the green case.

In particular, it is more desirable to vary the outside temperature through the jackets in a range lower than the outside temperature through the platens.

Here, it is preferable that the outside heat temperature through the pair of platens is kept constant within a range of 170 ° C to 180 ° C, and the outside temperature is variable within a range of 160 ° C to 180 ° C through the jackets.

Further, it is possible to vary the temperature of the outside heat through the jackets to correspond to the vulcanization steps according to the heat and pressure change of the pressure medium supplied to the bladder in the vulcanizer.

In addition, each of the vulcanizing steps may include a first vulcanizing step for supplying saturated water vapor to maintain the first pressure range and to be heated; A second vulcanizing step of additionally supplying saturated water vapor so as to be further heated while maintaining a second pressure range higher than the first pressure range; A third vulcanizing step of supplying nitrogen and pressurizing the nitrogen to maintain a third pressure range higher than the second pressure range; A fourth vulcanizing step of additionally supplying nitrogen to pressurize the nitrogen gas so as to maintain a fourth pressure range higher than the third pressure range; And a fifth vulcanizing step of discharging water vapor and nitrogen and reducing the pressure in the fourth pressure range to an atmospheric pressure state.

Here, the first pressure range is 5 kg / cm ² to 8 kg / cm ² Within, the second pressure range is 12kg / cm ² to and less than 17kg / cm ^2, the third pressure range is 15kg / cm ² to a 20kg / cm ² within the fourth pressure range is 20kg / cm ² to Cm < ² > or less.

In addition, the outer temperature is maintained in the first temperature range by the first vulcanizing step through the jackets, and the temperature is lowered in the second vulcanizing step to maintain the second temperature range lower than the first temperature range , And in the third vulcanizing step, heating is performed to maintain a third temperature range higher than the first temperature range in the second temperature range, and in the fourth vulcanizing step, It is preferable to maintain the temperature range and maintain the first temperature range by lowering the temperature in the fifth vulcanizing step.

Here, the first temperature range is within the range of 160 to 170 占 폚, the second temperature range is within the range of 155 to 165 占 폚, the third temperature range is within the range of 165 to 175 占 폚, The fourth temperature range may be within the range of 170 ° C to 180 ° C.

According to the run-through tire vulcanizing method of the present invention, the heat source supplied to the outer temperature supply chain platen and the jacket of the vulcanized tire vulcanizer during the run-flat tire vulcanization process is controlled to differentiate the vulcanized heat quantity of the side portion including the side wall portion and the vulcanized heat amount of the tread portion And by controlling the vulcanization of the rubber in each region, it is possible to secure the vulcanization uniformity as an end product suitable for the structural characteristics of the run flat tire and to reduce the energy required in the vulcanization process of the run flat tire.

1 is a front sectional view showing a run-flat tire vulcanizing apparatus according to a first embodiment of the present invention.
Fig. 2 is a graph showing change in internal pressure during run-flat tire vulcanization through the run-through tire vulcanizing apparatus of Fig. 1;
Fig. 3 is a graph showing the temperature change of the platen and the jacket during run-flat tire vulcanization in Fig. 2;

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.

1 is a front sectional view showing a run-flat tire vulcanizing apparatus according to a first embodiment of the present invention.

1, a vulcanizer 1 used in vulcanization of a run-flat tire according to the present invention may include a vulcanizer main body 10, a center poster 20, and a bladder 30.

The vulcanizing machine main body 10 is fixedly installed so that the vulcanizing dies made up of a plurality of segments form an inner vulcanizing surface so as to have an internal vulcanizing space into which the green case 100 is inserted to form the runplane tires.

In this embodiment, the main body 10 of the vulcanizer is provided with upper and lower platens 16 and 15, which are formed so as to correspond to the side portions of the green case, that is, the shoulder portion, the side wall portion, And the upper and lower platens 16 and 15 of the upper and lower lid parts 11 and 12 are provided with a plurality of vents 11 and 12 for holding the vulcanized dies in correspondence with the tread portion of the green case 100, (17, 18).

However, the present invention is not limited thereto, and it is possible to supply outside heat through the upper and lower platens 16 and 15 and the jackets 17 and 18 when vulcanizing the green case 100 constituting the run flat tire And may be applied to various forms as long as it can supply heat and pressure through a pressurized medium supplied into the bladder 30.

When the green case 100 for run-flat tire is placed in the vulcanizer main body 10, the required amount of heat is supplied in the form of external heat and heat and pressure (internal temperature and pressure).

The outside heat is supplied from the outside of the green case 100 (Greencase) by using platens 15 and 16 and a jacket 17 and 18, and the heat-resistant pressure is applied to the bottom of the center of the vulcanizer main body 10 And is supplied through a pressurized medium injected into the vulcanized bladder 30 formed inside the vulcanized space through the center posters 20 formed to pass through.

On the other hand, the green case 100 for forming the run flat tire maintains the tire shape even when the air pressure is leaked due to the tire damage due to external influences, and the reinforcing insert 110 is formed on the inner side of the side portion , And the thickness of the side portion is formed thicker than the ground and the tread portion when traveling.

As described above, in the case of the runplane tire, the side portion on which the insert rubber is structurally structured is formed thicker and the vulcanization speed becomes the lowest point. Since additional heat and time are needed to prevent the unburnt at this point, Unevenness in quality and quality, and lowering of productivity. Particularly, unbalance of the heat source supply may cause excessive amount of heat in the tread portion, which may lead to overflow.

Therefore, the run-through tire vulcanization method of the present invention is characterized in that when the green case 100 of the run-flat tire is placed in a vulcanizer 1 equipped with a vulcanization mold, The external heat supplied from the outside of the vulcanizer is varied in correspondence with the vulcanization steps according to the pressure change so that the vulcanization uniformity of the run flat tire can be adjusted according to the thickness variation of the side portion and the tread portion.

The run-through tire vulcanization method according to the present embodiment changes the external heat supplied from the outside of the vulcanizer 1 so as to correspond to the vulcanization steps according to the change in the heat and pressure, The outside temperature is maintained constant through the pair of platens 15 and 16 and the outside temperature is varied through the jackets 17 and 18 corresponding to the tread portion of the green case 100.

At this time, it is preferable to set the outside heat temperature through the jackets 17 and 18 to be lower than the outside heat temperature through the platens 15 and 16.

Therefore, the reinforcing insert 110 is provided to be relatively thick so that the outside temperature of the platens 15, 16 through the platens 15, 16 is maintained at a constant value higher than the temperature of the jackets 17, 18, It is possible to prevent the occurrence of uncrossing of thick side portions and to shorten the vulcanization time.

By setting the outer heat temperature through the jackets 17 and 18 to be lower than the outside heat temperature through the platens 15 and 16, the tread portion having a relatively thinner thickness than the side portions can reduce the excessive heat amount So that it is possible to prevent the occurrence of defects.

FIG. 2 is a graph showing the temperature change of the platen and the jacket during run-flat tire vulcanization in FIG. 1, and FIG. 3 is a graph showing the change in internal pressure during run-through tire vulcanization through the run-through tire vulcanization apparatus of FIG.

2 and 3, in the run-flat tire vulcanization process of the present embodiment, the external heat temperature through the platens 15 and 16 is kept constant at 175 ° C., which is within the range of 170 ° C. to 180 ° C., The outer heat temperature through the jackets 17 and 18 is varied within the range of 160 ° C to 180 ° C.

Particularly, the outer temperature of the jacket 17 and 18 is controlled by the bladder (not shown) inside the vulcanizer 1 so as to increase the uniformity of the vulcanization according to the thickness variation of the green case 100 for run flat tire, It is more preferable to vary the pressure in correspondence with the vortex steps due to the change in the heat and pressure inside the vulcanizer 1 through the pressurized medium supplied to the pressurized fluid.

The vulcanization steps according to the change in the pressure through the thermo-compression medium supplied to the bladder 30 in the vulcanizer 1 include a first vulcanizing step, a second vulcanizing step, a third vulcanizing step, a fourth vulcanizing step, Step.

Here, in the first and second vulcanizing steps, mainly the high-temperature saturated steam is used as the heating medium to supply the internal heat amount necessary for vulcanization. In the third vulcanizing step and the fourth vulcanizing step, high-pressure nitrogen gas is additionally used And the fifth vulcanizing step is a pressure reducing section that releases the internal pressure to the atmospheric pressure.

In this embodiment, in the first curing step, saturated water vapor is first fed into the bladder 30 to maintain the pressure within the first pressure range (5 kg / cm ² to 8 kg / cm ² ) ) Are heated and subjected to a fluidization process so as to have the shape of the finished product tire in the vulcanized metal mold.

On the other hand, during the first vulcanizing step, the outside heat temperature, which is heated through the platen (15, 16), comes into contact with the side portion of the thick green case having the reinforcing insert and is heated in a fourth temperature range (170 DEG C to 180 DEG C) Maintaining the outer temperature of the jackets 17, 18 in contact with the tread portion relatively thinner than the side portions at 175 DEG C to 165 DEG C in the first temperature range (160 DEG C to 170 DEG C).

In the second vulcanizing step, saturated water vapor is further supplied into the bladder 30 to maintain the pressure within a second pressure range (12 kg / cm ² to 17 kg / cm ² ) higher than the first pressure range, The semi-finished rubber constituting the green case 100 as a saturated steam column is heated and integrated so that the vulcanization process is performed so that the tensile strength is increased and the elasticity is strong.

On the other hand, during the second vulcanizing step, the outside heat temperature to be heated through the upper and lower platens 16 and 15 is kept constant at 175 ° C as described above. In particular, the outside temperature temperature heated through the jackets 17 and 18 And maintained at 160 DEG C in a second temperature range (155 DEG C to 165 DEG C) lower than the first temperature range.

As the pressure of the steam increases, the temperature supplied to the jackets 17 and 18 is lowered. As a result, the heat source applied from the outside is lowered by the increase of the heat source applied from the inside, The thin tread portion can be prevented from flowing and the vulcanization uniformity can be improved.

In the third vulcanizing step, the nitrogen gas is supplied and pressurized so as to maintain the third pressure range (15 kg / cm ² to 20 kg / cm ² ) higher than the second pressure range, Thereby promoting circulation within the bladder 30 of the saturated steam and facilitating the removal of condensed water caused by the temperature difference between the saturated steam and the nitrogen gas.

On the other hand, during the third vulcanizing step, the outside heat temperature to be heated through the upper and lower platens 16 and 15 is kept constant at 175 ° C as described above, and the outside temperature, which is heated through the jackets 17 and 18, Heating in the second temperature range to maintain 170 占 폚 in a third temperature range (165 占 폚 to 175 占 폚) higher than the first temperature range so that the amount of heat generated by the outside To increase the heat source to be compensated.

In the fourth vulcanizing step, nitrogen is additionally supplied to pressurize the fourth pressure range so as to maintain a fourth pressure range (20 kg / cm ² to 30 kg / cm ² ) higher than the third pressure range, So that they can be pushed toward the vulcanizing mold with a stronger pressure so that the air existing between them can be discharged.

On the other hand, during the fourth vulcanizing step, the outside heat temperature to be heated through the upper and lower platens 16 and 15 is kept constant at 175 ° C as described above, and the outside heat temperature, which is heated through the jackets 17 and 18, Is heated again to maintain 175 ° C in a fourth temperature range (170 ° C to 180 ° C), which is higher than the third temperature range, so that the proper temperature can be maintained so that the vulcanisation does not become insufficient until the vulcanization is finished.

In the fifth vulcanizing step, steam and nitrogen are discharged and the pressure is reduced to the atmospheric pressure state in the fourth pressure range. On the other hand, during the fifth vulcanizing step, the outside heat temperature to be heated through the upper and lower platens 15 and 16 is kept constant at 175 ° C as described above, and the outside temperature, which is heated through the jackets 17 and 18, To keep the temperature within a first temperature range (160 ° C to 170 ° C) at 165 ° C to prepare the next cycle of vulcanization and to reduce energy loss.

Experimental Example

Hereinafter, as shown in Table 1, each of the run flat tires was manufactured using the conventional tire vulcanizing method and the run-flat tire vulcanizing method according to one embodiment of the present invention, and their durability evaluations were performed.

division Comparative Example (Conventional) EXAMPLES (invention) Pressure-proof supply Outside temperature Pressure-proof supply Outside temperature Platten jacket Platten jacket The first vulcanizing step Saturated steam
(5 to 14 kg / cm2)



175 ° C



175 ° C Saturated steam
(5 to 8 kg / cm 2)



175 ° C 165 ° C
(160 ° C to 170 ° C) The second vulcanizing step Saturated steam
(12 to 17 kg / cm2) 160 ° C
(155 ° C to 165 ° C) The third vulcanizing step Saturated steam
(5 to 14 kg / cm2) Nitrogen gas
(15 to 20 kg / cm 2 170 ℃
(165 ° C to 175 ° C) The fourth vulcanizing step Nitrogen gas
(20 to 30 kg / cm2) 175 ° C
(170 ° C to 180 ° C) The fifth vulcanizing step Pressure release time Pressure release time 165 ° C
(160 ° C to 170 ° C) Vulcanization time 17.5 minutes 14.1 minutes

The durability evaluation of the runplatters is ECE-R30, which is a test standard for driving tires in the United States. It refers to the durability result that travels at a specified speed for each step. The unit is expressed in hours: minutes. Also, in the above, n denotes the number of test samples.

Therefore, as shown in Table 2, run-flat tires produced according to the run-flat tire vulcanization method of the present invention were evaluated as vulcanization and vulcanized tire vulcanization The uniformity is high and the vulcanization time can be shortened.

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: a vulcanizer 10: a vulcanizer main body
11: upper lid part 12: lower lid part
15; A lower platen 16; Upper platen
17, 18: Jacket 20: Center Poster
30: bladder 100: runlet tire green case
110: reinforcement insert

Claims (9)

A vulcanized tire vulcanizing method, comprising the steps of:

The outer circumferences of the vulcanized tire are adjusted so that the vulcanization uniformity of the run flat tires is adjusted according to the thickness variations of the side portions and the tread portions when the green case of the run flat tire is placed in the vulcanizer having the vulcanization mold,

Wherein the outer heat comprises a pair of platens constituting upper and lower sides of the vulcanizer,
A plurality of jackets arranged and joined circumferentially between the platens,

Maintaining the temperature of the outside temperature constant through the pair of platens corresponding to the side portions of the green case,
Varying the temperature of the outside heat through the jackets corresponding to the tread portion of the green case,

The outside temperature temperature through the jackets varying in a range lower than the outside temperature temperature through the platens,

The outside temperature through the pair of platens is kept constant within the range of 170 占 폚 to 180 占 폚,
Wherein the external temperature is varied within a range of 160 占 폚 to 180 占 폚 through the jackets.
delete delete delete The method of claim 1,
Wherein the outer heat temperature through the jackets is varied corresponding to a plurality of vulcanizing steps classified according to the degree of heat and pressure applied by the thermo-compression medium supplied to the bladder in the vulcanizer.
The method of claim 5,
Each of the above-
A first vaporizing step of supplying saturated water vapor to maintain the first pressure range to be heated;
A second vulcanizing step of additionally supplying saturated water vapor so as to be further heated while maintaining a second pressure range higher than the first pressure range;
A third vulcanizing step of supplying nitrogen and pressurizing the nitrogen to maintain a third pressure range higher than the second pressure range;
A fourth vulcanizing step of additionally supplying nitrogen to pressurize the nitrogen gas so as to maintain a fourth pressure range higher than the third pressure range; And
And a fifth vulcanizing step of discharging water vapor and nitrogen and reducing the pressure in the fourth pressure range to an atmospheric pressure range.
The method of claim 6,
The first pressure range is 5 kg / cm ² to 8 kg / cm ² Range _,
The second pressure range is 12kg / cm ² to 17kg / cm ² Range,
The third pressure range is 15 kg / cm ² to 20 kg / cm ² Range,
The fourth pressure range is 20 kg / cm ² to 30 kg / cm ² Of the run-flat tire vulcanizing method.
The method of claim 6,
The outside heat temperature through the jackets is
In the first vulcanizing step, the first temperature range is maintained by heating,
In the second vulcanizing step, the temperature is lowered to maintain a second temperature range lower than the first temperature range,
And in the third vulcanizing step, heating is performed to maintain a third temperature range higher than the first temperature range in the second temperature range,
In the fourth vulcanizing step, heating is performed to maintain a fourth temperature range higher than the third temperature range,
And the temperature is lowered in the fifth vulcanizing step to maintain the first temperature range.

9. The method of claim 8,
Wherein the first temperature range is within the range of 160 < 0 > C to 170 &
Wherein the second temperature range is within a temperature range of 155 ° C to 165 ° C,
Wherein the third temperature range is within the range of 165 ° C to 175 ° C,
And the fourth temperature range is within a temperature range of 170 占 폚 to 180 占 폚.

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