JP2017100297A - Tire vulcanizing bladder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tire vulcanizing bladder capable of measuring tire inner surface temperatures at the time of vulcanization without generating an adverse effect on mass-produced tires.SOLUTION: Provided is a vulcanizing bladder 10 used in vulcanizing a green tire set in a mold, which includes: a cylindrical bladder main body 11; a protrusion 12 formed integrally with the bladder main body 11 on an inner surface of the bladder main body 11; a non-through hole 13 which is extended toward an outer surface of the bladder main body 11 from an end part of the protrusion 12 while being formed in a non-through state for the outer surface of the bladder main body 11; a temperature measuring probe 14 inserted into the non-through hole 13 from an inner side of the bladder main body 11; and a fastening member 15 which fastens the protrusion 12 from outside to connect the temperature measuring probe 14 and the protrusion 12 with each other.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a tire vulcanization bladder used when vulcanizing a green tire set in a mold. More specifically, the tire inner surface temperature at the time of vulcanization is obtained without causing an adverse effect on mass-produced tires. The present invention relates to a bladder for tire vulcanization that can be measured.

  When vulcanizing a pneumatic tire, insert a bladder inside the green tire set in the mold and heat the green tire from the outside through the mold, while introducing a heating and pressurizing medium into the bladder Thus, the green tire is heated from the inside. In such a vulcanization process of a pneumatic tire, in order to accurately grasp the heat transfer to the green tire, in particular, the heat transfer to the carcass layer as a skeleton, the tire inner surface temperature during vulcanization can be measured. It is valid.

  Conventionally, in a vulcanization process of a pneumatic tire, as a method of measuring the temperature inside the tire, a temperature sensor is installed inside the bladder, or a temperature sensor is installed in the piping of the heating and pressurizing medium. It has been proposed (see, for example, Patent Documents 1 and 2).

  However, since the temperature inside the bladder does not necessarily coincide with the tire inner surface temperature at the time of vulcanization, the above method cannot accurately measure the tire inner surface temperature at the time of vulcanization. Therefore, a tire inner surface temperature at the time of vulcanization is measured by embedding a thermocouple in a test tire and disposing a probe of the thermocouple on the inner surface of the tire. In this case, although it is possible to accurately measure the tire inner surface temperature at the time of vulcanization, the thermocouple embedded in the tire has an adverse effect on the tire, so that it is difficult to apply to a mass-produced tire. Therefore, the method of embedding the thermocouple in the tire is effective only at the test stage.

Japanese Patent Laid-Open No. 7-40355 JP 2008-162269 A

  An object of the present invention is to provide a tire vulcanizing bladder that can measure the tire inner surface temperature during vulcanization without causing adverse effects on mass-produced tires.

  To achieve the above object, a tire vulcanizing bladder according to the present invention is a tire vulcanizing bladder used when vulcanizing a green tire set in a mold. A protrusion formed integrally with the bladder body on the inner surface of the bladder body, and extending from the end of the protrusion toward the outer surface of the bladder body, with respect to the outer surface of the bladder body Is a non-through hole in a non-through state, a temperature measurement probe inserted into the non-through hole from the inside of the bladder body, and the temperature measurement probe and the protrusion are tightened from the outside. And a fastening member to be coupled to each other.

  In the present invention, a protrusion is provided on the inner surface of the bladder main body, a non-through hole is formed in the protrusion in a non-penetrating state with respect to the outer surface of the bladder main body, and temperature is measured from the inside of the bladder main body to the non-through hole Temperature measurement at the site where the projection is provided by using a tire vulcanizing bladder that has a structure in which the probe is inserted and the projection is clamped from the outside with a clamping member to couple the temperature measurement probe and the projection together. The tire inner surface temperature during vulcanization can be measured based on the probe for use. Moreover, although the temperature measurement probe is disposed at a position close to the tire inner surface, it is held in the non-through hole, so that the tire inner surface is not damaged during vulcanization. Therefore, the tire inner surface temperature at the time of vulcanization can be measured without causing an adverse effect on the mass production tire.

  The tire vulcanizing bladder according to the present invention preferably includes an annular groove formed around the protrusion on the inner surface of the bladder main body. When the protrusions as described above are formed on the inner surface of the bladder main body, the thermal conductivity to the tire inner surface at the part where the protrusions are arranged will locally decrease, but an annular groove is provided around the protrusions. By doing so, thermal conductivity can be made uniform.

  Further, the outer diameter of the protrusion is equal to or less than the thickness of the bladder body, the outer diameter of the groove portion is three times or less than the thickness of the bladder body, and the depth of the groove portion is 1 / th of the thickness of the bladder body. 3 or less, and the outer diameter of the temperature measurement probe is preferably ¼ or less of the thickness of the bladder main body. Furthermore, the rubber thickness from the tip of the temperature measuring probe to the outer surface of the bladder body is preferably 1/10 or less of the thickness of the bladder body. By optimizing these dimensions, it is possible to accurately measure the tire inner surface temperature during vulcanization while minimizing inconveniences occurring in the tire vulcanization bladder.

  The tire vulcanizing bladder according to the present invention preferably includes protrusions and temperature measuring probes corresponding thereto at a plurality of locations in the circumferential direction of the bladder body. This makes it possible to simultaneously measure the tire inner surface temperatures at a plurality of locations in the tire circumferential direction.

  Moreover, it is preferable that the tire vulcanizing bladder according to the present invention includes protrusions and temperature measuring probes corresponding thereto at a plurality of locations in the radial direction of the bladder body. This makes it possible to simultaneously measure the tire inner surface temperatures at a plurality of locations in the tire radial direction.

It is a meridian half section view showing a tire vulcanizing device provided with a tire vulcanizing bladder according to an embodiment of the present invention. 1 is a meridian cross-sectional view showing a tire vulcanizing bladder according to an embodiment of the present invention. It is an equatorial sectional view showing a bladder for tire vulcanization according to an embodiment of the present invention. It is a perspective view which shows the processus | protrusion formed in the inner surface of a bladder main body, and the probe for temperature measurement corresponding to it. It is sectional drawing which shows the processus | protrusion formed in the inner surface of a bladder main body, and the probe for temperature measurement corresponding to it. It is sectional drawing which shows the principal part of the bladder for tire vulcanization | cure at the time of vulcanization | cure.

  Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows a tire vulcanizing apparatus equipped with a tire vulcanizing bladder according to an embodiment of the present invention, and FIGS. 2 to 6 show the tire vulcanizing bladder.

  As shown in FIG. 1, the tire vulcanizing apparatus includes a lower side plate 1 and an upper side plate 2 for forming a tire sidewall portion, and a lower bead ring 3 for forming a tire bead portion. And an upper bead ring 4 and a plurality of sectors 5 for forming a tread portion of the tire. From these lower side plate 1, upper side plate 2, lower bead ring 3, upper bead ring 4 and sector 5, The tire T is vulcanized and molded inside the mold. At the time of vulcanization, the bladder 10 is inserted inside the tire T. The structure of the mold is not particularly limited, and a split-type mold can be used in addition to the sectional type mold.

  The lower end portion of the bladder 10 is held between the lower clamp ring 6 and the lower bead ring 3, and the upper end portion thereof is held between the upper clamp ring 7 and the auxiliary ring 8. In the vulcanized state as shown in FIG. 1, the bladder 10 is expanded outward in the radial direction of the tire T. However, when the tire T is taken out from the mold after vulcanization, the upper clamp ring 7 moves upward. Accordingly, the bladder 10 is extracted from the inside of the tire T.

  As shown in FIGS. 2 and 3, the bladder 10 has a bladder body 11 formed in a cylindrical shape. As shown in FIGS. 4 and 5 on the inner surface of the bladder body 11. A plurality of projections 12 having a cylindrical shape protruding from the inner surface of the bladder main body 11 are formed integrally with the bladder main body 11. Each projection 12 is formed with a non-through hole 13 extending from an end portion thereof toward the outer surface of the bladder body 11 and not penetrating the outer surface of the bladder body 11. . A temperature measurement probe 14 is inserted into the non-through hole 13 from the inside of the bladder body 11. The temperature measuring probe 14 and the protrusion 12 are coupled to each other by tightening the tightening member 15 from the outside of the protrusion 12. As the temperature measurement probe 14, various temperature sensors represented by a thermocouple, a platinum resistance thermometer, and a thermistor can be used. The tightening structure by the tightening member 15 is not particularly limited, and examples thereof include ligation by a string-like member (fixing by tying) and caulking by a metal member.

  A lead wire 16 is connected to each temperature measurement probe 14, and the lead wire 16 is connected to a measurement device (not shown). In the tire vulcanizing apparatus, the lead wire 16 may be pulled out of the bladder 10 through the lower clamp ring 6, or may be pulled out of the bladder 10 through a central mechanism. It is necessary to ensure airtightness appropriately.

  In the tire vulcanizing apparatus using the tire vulcanizing bladder 10 described above, a protrusion 12 is provided on the inner surface of the bladder body 11, and the protrusion 12 is non-penetrating with respect to the outer surface of the bladder body 11. A hole 13 is formed, a temperature measurement probe 14 is inserted into the non-through hole 13 from the inside of the bladder main body 11, and the protrusion 12 is tightened from the outside by the fastening member 15, so that the temperature measurement probe 14 and the protrusion 12 are Since they are coupled, the temperature measurement probe 14 can be disposed in the vicinity of the tire inner surface S as shown in FIG. Therefore, in the vulcanization process of the tire T, the tire inner surface temperature at the time of vulcanization can be measured based on the temperature measurement probe 14. Further, although the temperature measuring probe 14 is disposed at a position close to the tire inner surface S, the temperature measuring probe 14 is held in the non-through hole 13 so that the tire inner surface S is not damaged during vulcanization. Therefore, the tire inner surface temperature at the time of vulcanization can be measured without causing an adverse effect on the mass production tire.

  In the tire vulcanizing bladder 10, as shown in FIGS. 4 and 5, an annular groove portion 17 is formed on the inner surface of the bladder body 11 so as to surround the protrusion 12. When the protrusion 12 is formed on the inner surface of the bladder main body 11, the thermal conductivity to the tire inner surface S at the portion where the protrusion 12 is disposed is locally reduced, but the annular groove 17 around the protrusion 12. By attaching, it is possible to make the thermal conductivity uniform. That is, during vulcanization, the inside of the tire vulcanizing bladder 10 is filled with a heating and pressing medium, and the heat of the medium is transmitted to the tire T. When the annular groove 17 is provided around the protrusion 12, the groove Since heat is transmitted to the back side of the protrusion 12 via 17, the thermal conductivity of the tire vulcanizing bladder 10 can be prevented from being locally reduced.

  In the tire vulcanizing bladder 10, the outer diameter Da of the protrusion 12 is preferably equal to or less than the thickness T of the bladder body 11. If the outer diameter Da of the protrusion 12 is larger than the thickness T of the bladder main body 11, the bladder main body 11 is difficult to swell uniformly, and as a result, the pressure applied by the bladder 10 is locally insufficient and the inner surface of the tire is molded. For example, the vulcanization failure may occur such that the transferred pattern by the bladder 10 becomes unclear. It is desirable that the outer diameter Da of the protrusion 12 is not less than ½ of the thickness T of the bladder body 11. Further, the thickness T of the bladder body 11 may be selected from a range of 1.5 mm to 8.0 mm.

  The outer diameter Db of the groove portion 17 is preferably not more than three times the wall thickness T of the bladder body 11. If the outer diameter Db of the groove portion 17 is larger than three times the wall thickness T of the bladder main body 11, the thinned portion of the bladder main body 11 is excessively formed. The outer diameter Db of the groove portion 17 is desirably 1.0 times or more the thickness T of the bladder main body 11.

  The depth d of the groove portion 17 is preferably 1/3 or less of the thickness T of the bladder main body 11. When the depth d of the groove portion 17 is larger than 1/3 of the thickness T of the bladder main body 11, a failure such as a gas leak is likely to occur in the bladder 10. The depth d of the groove portion 17 is desirably 1/10 or more of the thickness T of the bladder main body 11.

  The outer diameter Dc of the temperature measurement probe 14 is preferably ¼ or less of the thickness T of the bladder main body 11. When the outer diameter Dc of the temperature measurement probe 14 is larger than ¼ of the thickness T of the bladder main body 11, the bladder 10 is easily damaged.

  The rubber thickness t from the tip of the temperature measurement probe 14 to the outer surface of the bladder body 11 is preferably 1/10 or less of the thickness T of the bladder body 11. Thereby, the tire inner surface temperature at the time of vulcanization can be accurately measured. If the rubber thickness t from the tip of the temperature measurement probe 14 to the outer surface of the bladder main body 11 is larger than 1/10 of the thickness T of the bladder main body 11, the measurement sensitivity of the tire inner surface temperature decreases. However, in order to avoid damage to the bladder 10, the rubber thickness t from the tip of the temperature measurement probe 14 to the outer surface of the bladder main body 11 is preferably 1/30 or more of the thickness T of the bladder main body 11. .

  In the tire vulcanizing bladder 10, as shown in FIG. 3, the protrusions 12 and the temperature measuring probes 14 corresponding to the protrusions 12 are arranged at a plurality of locations in the circumferential direction of the bladder body 11. More preferably, the protrusions 12 and the corresponding temperature measurement probes 14 are arranged at equal intervals along the circumferential direction of the bladder body 11. In this case, the tire inner surface temperature at a plurality of locations in the tire circumferential direction can be measured simultaneously.

  In the tire vulcanizing bladder 10, as shown in FIG. 2, the protrusions 12 and the temperature measuring probes 14 corresponding to the protrusions 12 are arranged at a plurality of locations in the radial direction of the bladder body 11. This makes it possible to simultaneously measure the tire inner surface temperatures at a plurality of locations in the tire radial direction. In FIG. 1, the protrusion 12 and the temperature measurement probe 14 corresponding to the protrusion 12 are disposed mainly in the region corresponding to the tread portion of the tire T, but the protrusion 12 and the temperature measurement probe 14 may be disposed on the sidewall portion or the bead portion.

  In the above-described embodiment, the case where the protrusions 12 and the temperature measurement probes 14 corresponding thereto are arranged at a plurality of locations in the circumferential direction of the bladder body 11 and a plurality of locations in the radial direction of the bladder body 11 has been described. In some cases, for example, only one set of protrusions 12 and a temperature measuring probe 14 may be provided on the bladder main body 11.

  Using a tire vulcanizer equipped with a tire vulcanizing bladder, only the structure of the bladder was changed, and the pneumatic tire was repeatedly vulcanized.

  The bladders for tire vulcanization of Examples 1 to 7 are a bladder main body having a cylindrical shape, a protrusion formed integrally with the bladder main body on the inner surface of the bladder main body, and a bladder from an end of the protrusion. A non-through hole extending toward the outer surface of the main body and not penetrating the outer surface of the bladder main body, and a temperature measuring probe inserted into the non-through hole from the inside of the bladder main body And a clamping member that clamps the projection from the outside and couples the temperature measurement probe and the projection to each other.

  In these tire vulcanizing bladders of Examples 1 to 7, the presence or absence of an annular groove formed around the protrusion, the outer diameter Da of the protrusion, the outer diameter Db of the groove, the depth d of the groove, and the temperature measurement probe Table 1 shows the outer diameter Dc and the rubber thickness t from the tip of the temperature measurement probe to the outer surface of the bladder main body. The outer diameter Da of the protrusions, the outer diameter Db of the groove, the depth d of the groove, the outer diameter Dc of the temperature measurement probe, and the rubber thickness t are expressed as a ratio to the thickness T of the bladder body. The wall thickness T of the bladder body was 6 mm.

  For comparison, while using a normal bladder without protrusions, a temperature measurement probe was embedded in a pneumatic tire having the same structure as in Examples 1 to 7, and the same heating as in Examples 1 to 7 was performed on the pneumatic tire. Vulcanization was performed under pressure (Comparative Example 1). Moreover, the normal bladder which does not have a protrusion was used, and the vulcanization | cure was performed on the pneumatic tire which has the same structure as Examples 1-7 on the same heating-pressing conditions as Examples 1-7 (comparative example 2).

  About the Examples 1-7 mentioned above, the temperature measurement error, the tire vulcanization failure occurrence rate, and the bladder durability were evaluated by the following evaluation methods, and the results are also shown in Table 1.

Temperature measurement error:
The tire inner surface temperature during vulcanization was measured in a timely manner, and the maximum value of the temperature difference with respect to the tire inner surface temperature measured in Comparative Example 1 was obtained.

Tire vulcanization failure rate:
After 100 tires were vulcanized in each of Examples 1 to 7, the condition of the tire inner surface was confirmed by visual observation, the presence or absence of a vulcanization failure due to a local insufficient pressure of the bladder was examined, and the rate of occurrence was determined. Asked. The vulcanization failure here was judged based on criteria that are stricter than those for market tires.

Bladder durability:
In Examples 1 to 7, tire vulcanization was repeated, and the number of vulcanizations until a failure occurred in the bladder was measured. The evaluation results were shown as an index with the number of vulcanizations until the failure occurred in the bladder in Comparative Example 2 as 100. A larger index value means better bladder durability.

  As shown in Table 1, in Examples 1 to 7, the tire inner surface during vulcanization is suppressed while suppressing tire vulcanization failure, maintaining favorable bladder durability, and minimizing temperature measurement errors. The temperature could be measured. In particular, the evaluation result of Example 1 was good.

  On the other hand, since Example 2 did not have an annular groove around the protrusion, the heat conduction in the vicinity of the protrusion was slightly delayed. In Example 3, since the outer diameter Da of the protrusion was larger than the thickness T of the bladder body, the bladder body did not easily swell uniformly, and as a result, tire vulcanization failures increased slightly. In Example 4, since the outer diameter Db of the groove portion was larger than three times the wall thickness T of the bladder main body, gas leak from the bladder was likely to occur. In Example 5, since the depth d of the groove portion is larger than 1/3 of the thickness T of the bladder main body, gas leakage from the bladder is likely to occur. In Example 6, the outer diameter Dc of the temperature measurement probe was larger than 1/4 of the thickness T of the bladder main body, so that the bladder was easily damaged. In Example 7, since the rubber thickness t from the tip of the temperature measurement probe to the outer surface of the bladder main body was larger than 1/10 of the thickness T of the bladder main body, the measurement sensitivity of the tire inner surface temperature was lowered.

DESCRIPTION OF SYMBOLS 10 Bladder 11 Bladder main body 12 Protrusion 13 Non-through-hole 14 Temperature measurement probe 15 Tightening member 16 Lead wire 17 Groove part

Claims (6)

  In a tire vulcanizing bladder used when vulcanizing a green tire set in a mold, a cylindrical bladder main body is formed integrally with the bladder main body on the inner surface of the bladder main body. A projection extending from the end of the projection toward the outer surface of the bladder main body and not penetrating the outer surface of the bladder main body, and the inner side of the bladder main body A temperature measurement probe inserted into the non-through hole, and a vulcanizing member for tightening the protrusion from the outside and coupling the temperature measurement probe and the protrusion to each other. For bladder.   The tire vulcanization bladder according to claim 1, further comprising an annular groove formed around the protrusion on an inner surface of the bladder main body.   The outer diameter of the protrusion is equal to or less than the thickness of the bladder body, the outer diameter of the groove is three times or less the thickness of the bladder body, and the depth of the groove is the thickness of the bladder body. The bladder for tire vulcanization according to claim 2, wherein the bladder for tire vulcanization is not more than 1/3 of a thickness, and an outer diameter of the temperature measuring probe is not more than 1/4 of a thickness of the bladder main body.   The tire according to any one of claims 1 to 3, wherein a rubber thickness from a tip of the temperature measurement probe to an outer surface of the bladder body is 1/10 or less of a thickness of the bladder body. Vulcanization bladder.   The tire vulcanization bladder according to any one of claims 1 to 4, wherein the protrusions and temperature measuring probes corresponding thereto are provided at a plurality of locations in the circumferential direction of the bladder body.   The tire vulcanization bladder according to any one of claims 1 to 5, wherein the protrusions and temperature measurement probes corresponding thereto are provided at a plurality of locations in a radial direction of the bladder body.

Images