JP6962779B2 - Methods, systems and programs for detecting punctures in tire vulcanizing bladder - Google Patents

Description

The present disclosure relates to methods, systems and programs for detecting punctures occurring in tire vulcanizing bladder.

When the tire is vulcanized and molded, the vulcanization mold heats and pressurizes the raw tire from the outside, and the tire vulcanization bladder heats and pressurizes the raw tire from the inside by the heat medium filled inside. A bladder for tire vulcanization may be punctured due to aged deterioration, and molding a tire with a punctured bladder may lead to a tire defect. Therefore, various methods for detecting a puncture of a bladder have been conventionally proposed.

For example, Patent Documents 1 and 2 disclose a method of detecting a puncture by detecting the steam contained in the heat medium leaked from the bladder due to a puncture by using a humidity sensor that detects the steam.

Japanese Unexamined Patent Publication No. 2017-39288 Japanese Unexamined Patent Publication No. 2001-191332

As a prior art, a puncture detection method using a humidity sensor for detecting vapor has been disclosed, but no other method has been disclosed.

The present disclosure has focused on such issues, and an object thereof is a method, a system, and a program for detecting a puncture of a bladder for tire vulcanization, which can detect a puncture of a bladder only by a temperature sensor. Is to provide.

The present disclosure takes the following measures to achieve the above object.

That is, the method of detecting the puncture of the tire vulcanization bladder of the present disclosure is a puncture generated in the tire vulcanization bladder that heats and pressurizes the raw tire from the inside together with the vulcanization mold that heats and pressurizes the raw tire from the outside. Is a way to detect
A step of acquiring time-series data of the temperature between the inner surface of the tire and the bladder, which started detection from a predetermined time point corresponding to the time when the pressure was started to be released from the bladder with the end of vulcanization.
Based on the time-series data of the temperature, a step of determining whether or not an inflection point in which the temperature drops once and then rises is included is included.
If it is determined that the inflection point is included, it is determined that a puncture has occurred, and if it is determined that the inflection point is not included, it is determined that no puncture has occurred. ,
including.

When a puncture occurs, the steam contained in the heat medium liquefies as the pressure drops. Since the liquid takes away the heat of the surroundings and vaporizes, the temperature between the inner surface of the tire and the bladder drops once, but it rises again due to the heat of the surroundings and returns to the original temperature. Therefore, the time-series data of the temperature includes an inflection point where the temperature drops once and then rises again. Therefore, it is possible to determine a puncture based on the presence or absence of an inflection point using only the temperature sensor.

A cross-sectional view showing a tire vulcanization molding apparatus, and a block diagram showing a puncture detection system of a bladder for tire vulcanization. A flowchart showing a puncture detection processing routine executed by the system. The figure which shows the detection temperature of a temperature sensor and the internal pressure of a bladder. Explanatory drawing about approximation to linear expression using least squares method. The figure which shows the temperature change and the change of the inclination value for three examples. Explanatory drawing about contraction operation and expansion operation of bladder.

Hereinafter, one embodiment of the present disclosure will be described with reference to the drawings.

[System for detecting punctures in bladder for tire vulcanization]
As shown in FIG. 1, the tire vulcanization molding apparatus 1 includes a vulcanization die 13 having a sector 10, a side plate 11 and a bead ring 12, a tire vulcanization bladder 14 supported by a support mechanism 14a, and a bladder. It has a bladder drive unit 15 for supplying a heat medium into the 14 and removing gas from the bladder, and a control unit 2 for controlling each unit. The control unit 2 is realized by a computer and has a device control unit 20. The equipment control unit 20 controls the opening and closing of the vulcanization mold 13, the control of a heat source (not shown), and the operation of the bladder drive unit 15, and the vulcanization mold 13 heats and pressurizes the raw tire T from the outside and vulcanizes the tire. A vulcanization molding step is performed in which a heat medium (steam, nitrogen gas, etc.) is supplied to the bladder 14 to expand it, and the raw tire T is heated and pressed from the inside. Since the equipment control unit 20 is the same as a known vulcanization molding apparatus, detailed description thereof will be omitted.

The puncture detection system is applied to the tire vulcanization molding apparatus 1. A temperature detecting unit 16 for detecting the temperature between the inner surface of the tire and the bladder 14 is provided. The temperature detection unit 16 includes a temperature sensor and a high-precision digital probe that records the temperature data detected by the sensor. In the embodiment shown in FIG. 1, the bead ring 12 is provided with a hole to conduct the temperature detection unit 16, so that the temperature around the bead portion between the inner surface of the tire and the bladder 14 is measured. Not limited to this. As long as the temperature between the inner surface of the tire and the bladder 14 is detected, the temperature is not limited to the periphery of the bead portion, and any portion may be detected. In the present embodiment, there is only one detection location, but a plurality of detection locations may be detected.

The concept for determining a puncture only by the temperature detection unit 16 is as follows. In FIG. 3A, the time [sec] from the time when the internal pressure of the bladder is started to be released is shown on the horizontal axis, and the temperature [° C.] and the internal pressure of the bladder [MPa] detected by the temperature detection unit 16 are shown on the vertical axis. The temperature is shown by a solid line, and the internal pressure of the bladder is shown by a broken line. The temperature is kept constant. As shown in the figure, the device control unit 20 starts to release pressure from the bladder and recovers the heat medium inside the bladder for reuse. At this time, if the bladder 14 is punctured, steam leaks from the damaged portion of the bladder 14 between the inner surface of the tire and the bladder 14. Steam liquefies as the pressure drops. Since the liquid takes away heat from the surroundings and vaporizes, the temperature between the inner surface of the tire and the bladder 14 temporarily drops, but rises again due to the supply of heat from the surroundings, and the temperature returns. Therefore, the temperature drops once and rises again, so that an inflection point occurs in the temperature change as shown in FIGS. 3A and 4. Therefore, if there is an inflection point in the temperature change, it can be judged that the tire is punctured, and if there is no inflection point in the temperature change, it can be judged that the tire is not punctured.

In order to enable detection of a puncture only by the temperature detection unit 16, the puncture detection system includes a temperature data acquisition unit 21, an inflection point determination unit 22, and a puncture determination unit 23, as shown in FIG. ..

As shown in FIG. 3A, when the device control unit 20 reaches a predetermined timing (for example, a predetermined time or a predetermined internal pressure is reached) in which the recovery has progressed to some extent, the device control unit 20 brings the gas in the bladder into the atmosphere. Depressurize the inside of the bladder while releasing. Further, when the internal pressure of the bladder drops and reaches a predetermined timing (for example, a predetermined time or a predetermined internal pressure is reached), the device control unit 20 sets the inside of the bladder 14 as a negative pressure and bladder as shown in FIGS. 5 and 3A. The contraction operation of moving the 14 away from the inner surface of the tire and the expansion operation of applying pressure to the inside of the bladder 14 to bring the bladder 14 closer to the inner surface of the tire are alternately performed. In this way, by alternately executing the contraction operation and the expansion operation of the bladder 14, the heat medium leaked to the inner surface of the tire is detected even if the punctured portion is far from the detection position of the temperature detection unit 16. It is possible to guide to the detection position of the puncture, and it is possible to improve the detection accuracy of the puncture.

The temperature data acquisition unit 21 shown in FIG. 1 acquires the time-series data D1 of the temperature between the inner surface of the tire and the bladder 14 detected by the temperature detection unit 16. The temperature time series data D1 is stored in the memory. The temperature data acquisition unit 21 may acquire the temperature value from the temperature detection unit 16 at each detection time point and store it in the memory to obtain the temperature time series data D1 or all the detection time points from the temperature detection unit 16. The time series data D1 of the temperature including the temperature value of may be acquired.

At the time of vulcanization, a heat medium is supplied to the inside of the bladder 14, and a high pressure and high temperature state is maintained. The temperature detection unit 16 starts detecting the temperature from a predetermined time point corresponding to the time when the pressure is started to be released from the bladder 14 at the end of vulcanization. In the present embodiment, the temperature detection is started from the time when the pressure is started to be released, but the present invention is not limited to this. Temperature detection may be started, for example, after a predetermined time has elapsed, as long as it corresponds to the time when the pressure is started to be released. The temperature time series data D1 includes a plurality of temperature values detected each time a certain time elapses. In the present embodiment, the temperature is detected every second. For example, if the temperature is measured for 80 seconds, 80 temperature values can be obtained in chronological order. Of course, the measurement interval does not have to be every second and can be changed as appropriate. The temperature value was detected with the second decimal place as the minimum unit, but the temperature value is not limited to this and can be changed as appropriate.

The inflection point determination unit 22 shown in FIG. 1 determines whether or not an inflection point in which the temperature drops once and then rises again is included, based on the time series data D1 of the temperature. Specifically, the inflection point determination unit 22 includes an inflection point based on the temperature change amount calculation unit 24 that calculates the temperature change amount in a predetermined period and the temperature change amount calculated by the temperature change amount calculation unit 24. It has an existence determination unit 25 for determining whether or not it is present.

The temperature change amount calculation unit 24 calculates a linear slope value that approximates a predetermined number of temperature values by using the least squares method as the temperature change amount in a predetermined period. In the approximation by the least squares method, as shown in FIG. 3B, the coefficients a and b are determined so that the sum of squares of the residuals between the calculation result of the linear equation y = ax + b and the predetermined number of temperature values is minimized. y is the temperature axis, x is the time axis, and a is the approximate linear slope value. In the figure, the black circles represent the measured temperature values, and the arrows represent the residuals. If the predetermined number is 5, 1 second x 5 = 5 seconds is the predetermined period. In the present embodiment, the predetermined number is 5 or more and 30 or less, but the present invention is not limited to this. The slope of a straight line by the least squares method can be calculated by using the LINEST function in Excel (registered trademark) manufactured by Microsoft Corporation. The temperature change amount calculation unit 24 calculates the inclination value for each temperature detection time point.

Of course, it may be approximated to a quadratic or higher equation instead of a linear equation which is a linear equation. Further, an approximation method other than the approximation by the least squares method may be used. Further, the amount of temperature change in a predetermined period may be calculated by differential processing or the like without using the approximation method.

The existence determination unit 25 determines whether or not the inflection point is included based on the temperature change amount calculated by the temperature change amount calculation unit 24. The existence determination unit 25 may be configured to refer to a plurality of inclination values and determine that an inflection point is included when the inclination value becomes positive after becoming negative. In the present embodiment, in order to simplify the process, when the difference value obtained by subtracting the minimum value from the maximum value among the plurality of inclination values calculated by the temperature change amount calculation unit 24 is larger than the predetermined threshold value, it changes. It is configured to determine that an inflection point is included. Of course, when the difference value is equal to or greater than a predetermined threshold value, it may be determined that the inflection point is included. If the above conditions are not satisfied, it is determined that the inflection point is not included.

The puncture determination unit 23 determines that an inflection has occurred when it is determined that the inflection point is included, and determines that no puncture has occurred when it is determined that the inflection point is not included. judge. The determination result is preferably notified through a notification means such as a speaker, a display, or transmission of a signal to an external computer.

FIG. 4 is a diagram showing the effect of puncture detection of this system. The horizontal axis shows the elapsed time [sec] from the time when the depressurization of the bladder is started, and the vertical axis shows the temperature value detected by the temperature detection unit 16 and the linear inclination obtained by approximating the temperature value by the least squares method. The value and is shown. The temperature is shown by a solid line, and the slope value is shown by a broken line. The part corresponding to the inflection point is indicated by an ellipse. The illustrated temperature value is detected every second, and the illustrated inclination value is calculated by approximating the five temperature values.

(1) The graph at the top of FIG. 4 shows an example in which the difference between the maximum value and the minimum value of the detected temperature is about 2 ° C. (1.97 ° C.), and the bladder 14 is punctured. The contraction operation and the expansion operation of the bladder 14 are alternately executed. It was verified whether or not a puncture could be detected by setting a predetermined threshold value to 0.1 and changing a predetermined number when calculating the slope value a as follows.
<In the case of predetermined numbers 5, 10, 15, 20, 30>
The maximum values of inclination are 0.10, 0.09, 0.09, 0.09, and 0.03, respectively. The minimum values are -0.35, -0.24, -0.17, -0.12, and -0.08, respectively. The difference values are 0.45, 0.34, 0.26, 0.21 and 0.11 in that order. Since both difference values were larger than 0.1, it was determined that there was a puncture. It matched the result, and the system could automatically determine the puncture.
<In the case of a predetermined number of 40>
The maximum value of the inclination was 0.00, the minimum value was −0.05, and the difference between the two was 0.05, which was not 0.05> 0.1. Therefore, it was determined that there was no puncture. The result was different, and the system could not automatically determine the puncture.
From the above results, it can be seen that under this condition, the predetermined number is preferably 5 or more and 30 or less.

(2) The graph in the middle of FIG. 4 is an example in which the difference between the maximum value and the minimum value of the detected temperature is about 1 ° C. (1.07 ° C.), and the bladder 14 is punctured. The contraction operation and the expansion operation of the bladder 14 are alternately executed. It was verified whether or not a puncture could be detected by setting a predetermined threshold value to 0.1 and changing a predetermined number when calculating the slope value a as follows.
<In the case of predetermined numbers 5, 10, 15 and 20>
The maximum value of the slope is 0.05. The minimum values are -0.18, -0.13, -0.09, and -0.06, respectively. The difference between the two is 0.23, 0.17, 0.13, and 0.11, respectively. Since both difference values are larger than 0.1, it was determined that there was a puncture. It matched the result, and the system could automatically determine the puncture.
<In the case of a predetermined number of 30>
The maximum value of the inclination was 0.02, the minimum value was -0.04, the difference between the two was 0.06, and 0.06> 0.1, so it was determined that there was no puncture. The result was different, and the system could not automatically determine the puncture.
From the above results, it can be seen that under this condition, the predetermined number is preferably 5 or more and 20 or less.

(3) The graph at the bottom of FIG. 4 shows an example in which the difference between the maximum value and the minimum value of the detected temperature is about 1 ° C. (1.14 ° C.), and the bladder 14 is not punctured. The contraction operation and the expansion operation of the bladder 14 are alternately executed. It was verified whether or not a puncture could be detected by setting a predetermined threshold value to 0.1 and changing a predetermined number when calculating the slope value a as follows.
<In the case of predetermined numbers 5, 10, 15, 20, 30>
The maximum value of the inclination is 0.04 in each case. The minimum values are -0.03, -0.02, -0.01, -0.01, 0.00, respectively. The difference values are 0.07, 0.05, 0.05, 0.05, and 0.04, respectively. Since all the difference values were 0.1 or less, it was determined that there was no puncture. It matched the result, and the system could automatically determine the puncture.

(4) Alternate execution of contraction operation and expansion operation of the bladder 14 When a portion farther than the detection position of the temperature detection unit 16 is punctured, for example, the detection position of the temperature detection unit 16 is around the upper bead portion, and the punctured portion is In the case of the lower part of the bladder, the puncture could be detected by alternately executing the contraction operation and the expansion operation of the bladder 14, but the puncture could not be detected unless the bladder 14 was executed. As a countermeasure, if the temperature detection unit 16 has a plurality of detection positions, it is considered that a puncture can be detected even if the bladder 14 does not expand and contract.
From the above results, it is considered that the predetermined number is preferably 5 or more and 15 or less, and more preferably 5 or more and 10 or less.

[How to detect a flat tire vulcanizing bladder]
The operation of the system will be described with reference to FIG.

First, in step ST1, the temperature data acquisition unit 21 starts detecting the temperature between the inner surface of the tire and the bladder 14 at a predetermined time corresponding to the time when the pressure is started to be released from the bladder 14 due to the end of vulcanization. Acquire the series data D1. In the present embodiment, the temperature detection is started from the time when the pressure is started to be released from the bladder 14. The temperature time series data D1 includes a plurality of temperature values detected each time a certain time (1 second in the present embodiment) elapses.

Next, the inflection point determination unit 22 determines whether or not an inflection point in which the temperature drops once and rises again is included, based on the time-series data D1 of the temperature. The inflection point determination unit 22 determines whether or not the inflection point is included based on the temperature change amount calculation unit 24 that calculates the temperature change amount in a predetermined period and the temperature change amount calculated by the temperature change amount calculation unit 24. It has an existence determination unit 25 and the like.

In step ST2, the temperature change amount calculation unit 24 approximates a predetermined number of temperature values to a linear expression using the least squares method, and calculates the approximate linear slope value as the temperature change amount in a predetermined period. The amount of temperature change is calculated at each temperature detection time point.

In the next step ST3, the existence determination unit 25 determines that the difference value obtained by subtracting the minimum value from the maximum value among the plurality of inclination values calculated by the temperature change amount calculation unit 24 is larger than or greater than the predetermined threshold value. When there is (ST3: YES), it is determined that the inflection point is included (ST4), and when the above condition is not satisfied (ST3: NO), it is determined that the inflection point is not included (ST5).

When it is determined that the inflection point is included (ST4), the puncture determination unit 23 determines that a puncture has occurred in step ST6. When it is determined that the inflection point is not included (ST5), the puncture determination unit 23 determines in step ST7 that no puncture has occurred.

As described above, the puncture detection method of the present embodiment is
A method in which a computer detects a puncture generated in a tire vulcanization bladder 14 that heats and pressurizes a raw tire T from the inside together with a vulcanization die 13 that heats and pressurizes the raw tire T from the outside.
A step (ST1) of acquiring time-series data D1 of the temperature between the inner surface of the tire and the bladder 14, which started detection from a predetermined time point corresponding to the time when the pressure was started to be released from the bladder 14 with the end of vulcanization.
Based on the time series data D1 of the temperature, the step (ST2 to ST5) of determining whether or not the inflection point where the temperature drops once and rises again is included, and
When it is determined that the inflection point is included (ST4), it is determined that a puncture has occurred, and when it is determined that the inflection point is not included (ST5), it is determined that no puncture has occurred. Judgment steps (ST6-7) and
including.

The puncture detection system of this embodiment is
It is a system that detects a puncture generated in a tire vulcanization bladder 14 that heats and pressurizes a raw tire T from the inside together with a vulcanization die 13 that heats and pressurizes the raw tire T from the outside.
A temperature data acquisition unit 21 for acquiring time-series data D1 of the temperature between the inner surface of the tire and the bladder 14, which started detection from a predetermined time point corresponding to the time when the pressure was started to be released from the bladder 14 with the end of vulcanization.
Based on the time-series data D1 of the temperature, the inflection point determination unit 22 for determining whether or not the inflection point where the temperature drops once and rises again is included,
If it is determined that the inflection point is included, it is determined that a puncture has occurred, and if it is determined that the inflection point is not included, it is determined that a puncture has not occurred. 23 and
including.

When a puncture occurs, the steam contained in the heat medium liquefies as the pressure drops. Since the liquid takes away heat from the surroundings and vaporizes, the temperature between the inner surface of the tire and the bladder 14 drops once, but rises again due to the heat of the surroundings and returns to the original temperature. Therefore, the time-series data D1 of the temperature includes an inflection point at which the temperature drops once and rises again. Therefore, it is possible to determine a puncture based on the presence or absence of an inflection point using only the temperature sensor.

In the present embodiment, the temperature change amount calculation unit 24 calculates the temperature change amount in a predetermined period (ST2), and the existence determination unit 25 determines whether or not the inflection point is included based on the temperature change amount. The predetermined period may be set to a period corresponding to a predetermined number of temperature values (predetermined number × detection interval), or may be set to an infinitesimal value.

If there is an inflection point where the temperature drops once and then rises again, the amount of temperature change in a predetermined period becomes a negative value, and the amount of temperature change in a predetermined period thereafter becomes a positive value. Therefore, it is possible to detect an inflection point by referring to the amount of temperature change in a predetermined period.

In the present embodiment, the temperature time series data D1 includes a plurality of temperature values detected each time a certain time (1 second) elapses.
The temperature change amount calculation unit 24 approximates a predetermined number of temperature values to a linear equation [y = ax + b] using the least squares method, and calculates the approximate linear slope value a as the temperature change amount in a predetermined period. ..

In this way, since a predetermined number of temperature values, that is, a slope value a that matches the temperatures at a plurality of detection points in a period corresponding to the predetermined number is calculated, it is resistant to noise and changes without overlooking a minute change in temperature. It becomes possible to detect an inflection point.

In the present embodiment, the temperature change amount calculation unit 24 calculates the inclination value a for each temperature detection time point, and the existence determination unit 25 subtracts the minimum value from the maximum value among the calculated plurality of inclination values. When the difference value is larger than the predetermined threshold value or equal to or larger than the predetermined threshold value, it is determined that the inflection point is included.

As a method of detecting an inflection point, it is conceivable to refer to the slope value a that changes in time series, and detect that the slope value a is a negative value and then the slope value a is changed to a positive value. Be done. However, as described above, if the difference value obtained by subtracting the minimum value from the maximum value among the plurality of slope values a is compared with the predetermined threshold value, the maximum value and the minimum value are extracted, subtracted, and the value is compared. With such a simple process, the inflection point can be detected and the mounting cost can be reduced.

In the present embodiment, the device control unit 20 makes a negative pressure inside the bladder 14 to move the bladder 14 away from the inner surface of the tire at a predetermined timing, and applies pressure to the inside of the bladder 14 to direct the bladder 14 toward the inner surface of the tire. The expansion operation of bringing the tires closer to each other is performed alternately.

By executing such an operation, even if the puncture point is farther than the detection position of the temperature detection unit 16, the heat medium leaking to the inner surface of the tire can be guided to the detection position of the sensor, and the puncture can be detected. It is possible to improve the accuracy.

The program of this embodiment causes a computer to execute each step constituting the above method.
By executing these programs, it is possible to obtain the effects of the above method. In other words, it can be said that the above method is used.

Although the embodiments of the present disclosure have been described above with reference to the drawings, it should be considered that the specific configuration is not limited to these embodiments. The scope of the present disclosure is shown not only by the description of the above-described embodiment but also by the scope of claims, and further includes all modifications within the meaning and scope equivalent to the scope of claims.

For example, the execution order of each process such as operation, procedure, step, and step in the device, system, program, and method shown in the claims, specification, and drawings may be the output of the previous process after the output. Unless used in processing, it can be realized in any order. Even if the claims, the specification, and the flow in the drawings are explained using "first", "next", etc. for convenience, it does not mean that it is essential to execute in this order. ..

For example, although each of the parts 20 to 25 shown in FIG. 1 is realized by executing a predetermined program on the CPU of the computer, each part may be configured by a dedicated memory or a dedicated circuit.

In the system of this embodiment, each part 20 to 25 is mounted on one computer, but each part 20 to 25 may be distributed and mounted on a plurality of computers.

It is possible to adopt the structure adopted in each of the above embodiments in any other embodiment. The specific configuration of each part is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present disclosure.

13 ... Vulcanization mold 14 ... Tire vulcanization bladder 16 ... Temperature detection unit 20 ... Equipment control unit 21 ... Temperature data acquisition unit 22 ... Inflection point determination unit 23 ... Puncture determination unit 24 ... Temperature change amount calculation unit 25 ... Existence judgment unit

Claims (11)

It is a method of detecting a puncture generated in a tire vulcanization bladder that heats and pressurizes a raw tire from the inside by a heat medium containing steam filled inside together with a vulcanization mold that heats and pressurizes the raw tire from the outside. ,
A step of acquiring time-series data of the temperature between the inner surface of the tire and the bladder, which started detection from a predetermined time point corresponding to the time when the pressure was started to be released from the bladder with the end of vulcanization.
Based on the time-series data of the temperature, a step of determining whether or not an inflection point in which the temperature drops once and then rises is included is included.
If it is determined that the inflection point is included, it is determined that a puncture has occurred, and if it is determined that the inflection point is not included, it is determined that no puncture has occurred. ,
A method of detecting a flat tire vulcanizing bladder, including. The method according to claim 1, wherein the amount of temperature change in a predetermined period is calculated, and whether or not the inflection point is included is determined based on the amount of temperature change. The time series data of the temperature includes a plurality of temperature values detected every time a certain time elapses.
The method according to claim 2, wherein a predetermined number of temperature values are approximated to a linear formula by using the least squares method, and the value of the slope of the approximate linear formula is calculated as the amount of temperature change in the predetermined period. The slope value is calculated for each temperature detection time point, and when the difference value obtained by subtracting the minimum value from the maximum value among the calculated plurality of slope values is larger than the predetermined threshold value or greater than or equal to the predetermined threshold value. The method according to claim 3, wherein it is determined that the inflection point is included. At a predetermined timing, an expansion / contraction operation in which the inside of the bladder is made negative pressure to move the bladder away from the inner surface of the tire and an expansion operation in which pressure is applied to the inside of the bladder to bring the bladder closer to the inner surface of the tire are alternately performed. The method according to any one of claims 1 to 4. It is a system that detects punctures generated in a tire vulcanization bladder that heats and pressurizes the raw tire from the inside with a heat medium containing steam filled inside, together with a vulcanization mold that heats and pressurizes the raw tire from the outside. ,
A temperature data acquisition unit that acquires time-series data of the temperature between the inner surface of the tire and the bladder, which started detection from a predetermined time point corresponding to the time when the pressure was started to be released from the bladder with the end of vulcanization.
Based on the time-series data of the temperature, an inflection point determination unit that determines whether or not there is an inflection point in which the temperature drops once and then rises again.
If it is determined that the inflection point is included, it is determined that a puncture has occurred, and if it is determined that the inflection point is not included, it is determined that a puncture has not occurred. Department and
A system for detecting punctures in bladder for tire vulcanization, including. The inflection point determination unit includes a temperature change amount calculation unit that calculates the temperature change amount in a predetermined period, and an existence determination unit that determines whether or not the inflection point is included based on the temperature change amount. , The system according to claim 6. The time series data of the temperature includes a plurality of temperature values detected every time a certain time elapses.
According to claim 7, the temperature change amount calculation unit approximates a predetermined number of temperature values to a linear expression using the least squares method, and calculates the value of the slope of the approximate linear expression as the temperature change amount in the predetermined period. Described system. The temperature change amount calculation unit calculates the value of the inclination at each time when the temperature is detected.
When the difference value obtained by subtracting the minimum value from the maximum value among the plurality of inclination values calculated by the temperature change amount calculation unit is larger than the predetermined threshold value or equal to or larger than the predetermined threshold value, the existence determination unit is described. The system according to claim 8, wherein it is determined that an inflection point is included. A device that alternately performs an expansion / contraction operation in which the inside of the bladder is made negative pressure to move the bladder away from the inner surface of the tire and an expansion operation in which pressure is applied to the inside of the bladder to bring the bladder closer to the inner surface of the tire at a predetermined timing. The system according to any one of claims 6 to 9, which includes a control unit. A program that causes a computer to execute the method according to any one of claims 1 to 5.

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