JP2017039288A - How to detect bladder puncture - Google Patents

Abstract

A bladder puncture generated in a tire vulcanizer can be detected with high accuracy regardless of a bladder puncture generation position and without being affected by the humidity of the outside air, thereby preventing a decrease in productivity. A method for detecting bladder punk is provided. A bladder puncture generated in a tire vulcanizing bladder when a green tire is heated and pressurized from the outside with a vulcanizing mold and a green tire is heated and pressurized from the inside with a tire vulcanizing bladder to perform vulcanization molding. Is a method of detecting bladder puncture by a bladder puncture sensor. A bladder puncture detection method that detects the occurrence of bladder puncture by the bladder puncture sensor while sending it to the vicinity of the bladder puncture sensor. [Selection diagram] None

Description

  The present invention relates to a bladder puncture detection method capable of detecting a bladder puncture generated in a tire vulcanizer with high accuracy.

  In general, a pneumatic tire is vulcanized and commercialized by setting the raw tire in a tire vulcanizer and heating and pressurizing it from both the inside and the outside of the raw tire.

  Specifically, while a raw tire is heated and pressurized from the outside by a vulcanization mold, a tire vulcanizing bladder (hereinafter, also simply referred to as “bladder”) disposed in the inner cavity of the raw tire from the inside. In addition, the raw tire is heated and pressurized by supplying and expanding a heating and pressing medium containing water vapor.

  The bladder used in such a vulcanization process may be punctured because it is made of rubber, and if vulcanization is performed without noticing the occurrence of puncture, water vapor leaks from the bladder, leading to the generation of defective tires, and productivity May decrease.

  Therefore, in order to prevent the occurrence of defective tires by not being aware of the occurrence of such bladder puncture (hereinafter also referred to as “BLP”), conventionally, a bladder puncture sensor (hereinafter referred to as “ BLP is detected by detecting water vapor leaked from the bladder during the period from the start to the end of vulcanization (for example, Patent Document 1).

JP 2001-191332 A

  However, in the above case, since the BLP sensor is provided in the upper part of the vulcanization mold, there is a large difference in detection accuracy depending on the generation position of BLP, and it is difficult to detect BLP generated particularly in the lower part of the bladder. there were.

  In addition, since the BLP sensor is a sensor that detects water vapor, the BLP generation alarm may be activated (false detection) even though BLP is not generated due to the humidity condition of the outside air.

  Therefore, the present invention accurately detects the bladder puncture generated in the tire vulcanizer regardless of the position where the bladder puncture occurs and is not affected by the humidity condition of the outside air, thereby preventing a decrease in productivity. It is an object of the present invention to provide a bladder puncture detection method that can be used.

The invention described in claim 1
When the raw tire is heated and pressurized from the outside by a vulcanization mold and the raw tire is heated and pressurized from the inside by a tire vulcanization bladder to vulcanize and mold the bladder puncture generated in the tire vulcanization bladder A method for detecting bladder puncture detected by a sensor,
The bladder puncture sensor is configured to move the upper bead ring provided in the vulcanization mold up and down to send water vapor leaked from the bladder puncture generated in the tire vulcanization bladder to the vicinity of the bladder puncture sensor. Thus, the bladder puncture detection method is characterized by detecting the occurrence of bladder puncture.

The invention described in claim 2
2. The bladder puncture according to claim 1, wherein detection by the bladder puncture sensor is performed from the time when discharge of the heating and pressurizing medium is started from the tire vulcanization bladder to the completion of the opening operation of the vulcanization mold. This is a detection method.

The invention according to claim 3
The up and down operation of the upper bead ring is performed from the time when the pressure in the tire vulcanizing bladder is lowered to a predetermined pressure due to the discharge of the pressurized heating medium to the start of the opening operation of the vulcanizing mold. The method for detecting bladder puncture according to claim 1 or 2.

The invention according to claim 4
4. The bladder puncture detection method according to claim 3, wherein the vertical movement of the upper bead ring is started when the pressure in the tire vulcanizing bladder reaches 15 to 25 kPa. 5.

  According to the present invention, the bladder puncture generated in the tire vulcanizer is accurately detected regardless of the position where the bladder puncture occurs, and without being affected by the humidity condition of the outside air, thereby preventing a decrease in productivity. It is possible to provide a method for detecting a bladder puncture.

It is sectional drawing which shows typically the tire vulcanizer used in the detection method of the bladder puncture which concerns on one embodiment of this invention. It is a figure explaining the pressure change in a bladder in each process at the time of vulcanization.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1. Tire Vulcanizer FIG. 1 is a cross-sectional view schematically showing a tire vulcanizer used in the present embodiment.

  The tire vulcanizer 1 used in the present embodiment has basically the same configuration as a conventional tire vulcanizer. That is, bead rings 22 and 24 are attached to the upper and lower sides, a center post 2 concentric with the tire shaft, upper and lower platen plates 4 and 6, an upper mold 12 and a lower mold 14, a vulcanization mold 16, a bladder 34, and a BLP. The sensor 40 and the determination means 42 are provided. The center post 2 includes a columnar cylinder 20, and the upper bead ring 22 can be moved up and down by the expansion and contraction drive of the cylinder 20.

  The BLP sensor 40 is a humidity sensor attached to a communication hole 44 formed in the upper platen plate 4.

  The determination means 42 is connected to the BLP sensor 40 via a cable, receives the humidity detected by the BLP sensor 40, and compares it with a preset threshold value to determine whether or not BLP has occurred in the bladder 34. Determine.

2. Next, a bladder puncture detection method according to this embodiment using the tire vulcanizer having the configuration shown in FIG. 1 will be described. In addition, FIG. 2 is a figure explaining the pressure change in the bladder in each process at the time of vulcanization.

Also in the present embodiment, the “inf.S process” and “N ₂ gas process” in which the vulcanization mold 16 is closed and the tire is held for a predetermined time under a predetermined internal pressure of the bladder, as in the prior art. Then, the raw tire is vulcanized (see FIG. 2).

  After the above vulcanization is completed, an evacuation process is performed to reduce the pressure in the bladder 34 and then the vulcanization mold 16 is opened. In the present embodiment, in this evacuation process, the cylinder is The BLP is detected while the upper bead ring 22 is moved up and down by repeating 20 expansion and contraction. The upper and lower bead rings 22 are moved up and down to move the entire bladder 34 up and down, the air inside the vulcanizing mold 16 is stirred, and the air between the tire T and the bladder 34 is sent to the vicinity of the BLP sensor 40.

  The BLP sensor 40 detects the humidity in the air that has been sent and transmits the result to the determination means 42. The determination unit 42 compares the detection result with a preset threshold value, and determines that BLP has occurred in the bladder 34 when the threshold value is exceeded.

  Then, when the vulcanization mold 16 is fully opened and opened, the exhaust process is terminated, and the detection of BLP is also terminated accordingly.

  As described above, in the present embodiment, when the BLP is detected, the upper bead ring 22 is moved up and down to move the entire bladder 34 up and down so that the air between the tire T and the bladder 34 is moved to the BLP sensor 40. Since it can be sent to the vicinity, even when BLP is generated in the lower part of the bladder 34 away from the BLP sensor 40, the leaked water vapor can be sent to the vicinity of the BLP sensor 40, and BLP is generated. Can be sufficiently detected. As a result, the occurrence of BLP can be detected with high accuracy, and the occurrence of defective tires that become scrap can be limited to only one, so that the productivity is not reduced.

  In addition, by sending the air between the tire T and the bladder 34 to the vicinity of the BLP sensor 40, it is possible to suppress the influence of the humidity of the outside air when detecting the BLP, thereby preventing erroneous detection due to the influence of the outside air humidity. From this aspect, the occurrence of BLP can be detected with high accuracy.

  The time for detecting BLP by the BLP sensor 40 in the exhaust process is preferably set to the time from when the exhaust process is started until the opening operation of the vulcanization mold 16 is completed.

  Further, it is preferable that the up and down operation of the upper bead ring 22 is performed from the time when the pressure in the bladder 34 is reduced to a predetermined pressure that is a safe pressure until the opening operation of the tire vulcanizer is started. This “predetermined pressure as a safe pressure” is preferably 15 to 25 kPa, and most preferably about 20 kPa.

  In the present embodiment, it is preferable that the vertical movement of the center post 2 is automatically performed in accordance with the pressure drop in the bladder 34 in the exhaust process. The threshold value set in the determination means 42 can be freely changed and set according to the tire specifications.

  The vulcanization mold is set in the tire vulcanizer using bolts and the like, but the bolt holes after the setting are preferably closed from the viewpoint of accurately detecting BLP.

  Hereinafter, the present invention will be described based on examples.

1. Example In the example, BLP was detected while moving the upper bead ring up and down using the vulcanizer having the configuration shown in FIG. 1, and 3300 tires having a size of 225 / 65R17 were vulcanized. In this embodiment, the upper bead ring is set to start up and down when the pressure in the bladder is lower than 20 kPa.

Then, the Inf. The pressure in the bladder in the S step was set to 14.7 MPa, and the pressure in the N ₂ gas supply step was set to 21.5 MPa. Further, the exhaust speed in the exhaust process was set to 110 kPa / second.

2. Comparative Example (1) Comparative Example 1 (Conventional Example)
In Comparative Example 1, the upper bead ring was not moved up and down, and BLP was detected in all steps as before. The other conditions were set to the same conditions as in the example.

(2) Comparative Example 2
In Comparative Example 2, the tire was vulcanized under the same conditions as in the Comparative Example except that the BLP sensor was not operated.

3. Evaluation Results In the example, there were 14 BLPs generated in the lower part of the bladder, but all of them could be detected, and generation of defective tires (scrap tires) due to BLP could be reduced to zero. In addition, there were 0 false detections.

  On the other hand, in Comparative Example 1, two BLPs were detected in the BLP inspection, but 13 BLPs were actually generated in the lower part of the bladder, and defective tires (scrap tires) generated by 11 cases that were not detected. ) Reached a total of 77 (7 per case). The number of false detections reached nine.

  In Comparative Example 2, the process was terminated when one BLP was generated and seven defective tires were generated, and was not performed thereafter.

  From the above results, by operating the upper bead ring up and down, even when BLP occurs in the lower part of the bladder, it is possible to detect the occurrence of BLP with high accuracy and to appropriately prevent the generation of tires and erroneous detection due to BLP. I was able to confirm that it was possible.

  As mentioned above, although this invention was demonstrated based on embodiment, this invention is not limited to said embodiment. Various modifications can be made to the above-described embodiment within the same and equivalent scope as the present invention.

DESCRIPTION OF SYMBOLS 1 Tire vulcanizer 2 Center post 4 Upper platen plate 6 Lower platen plate 12 Upper mold 14 Lower mold 16 Vulcanization mold 20 Cylinder 22 Upper bead ring 24 Lower bead ring 34 Bladder 40 BLP sensor 42 Judgment means 44 Communication hole T Tire

Claims (4)

When the raw tire is heated and pressurized from the outside by a vulcanization mold and the raw tire is heated and pressurized from the inside by a tire vulcanization bladder to vulcanize and mold the bladder puncture generated in the tire vulcanization bladder A method for detecting bladder puncture detected by a sensor,
The bladder puncture sensor is configured to move the upper bead ring provided in the vulcanization mold up and down to send water vapor leaked from the bladder puncture generated in the tire vulcanization bladder to the vicinity of the bladder puncture sensor. A method for detecting a bladder puncture, comprising detecting occurrence of a bladder puncture.   2. The bladder puncture according to claim 1, wherein detection by the bladder puncture sensor is performed from the time when discharge of the heating and pressurizing medium is started from the tire vulcanization bladder to the completion of the opening operation of the vulcanization mold. Detection method.   The up and down operation of the upper bead ring is performed from the time when the pressure in the tire vulcanizing bladder is lowered to a predetermined pressure due to the discharge of the pressurized heating medium to the start of the opening operation of the vulcanizing mold. The method for detecting bladder puncture according to claim 1 or 2.   The bladder puncture detection method according to claim 3, wherein the up and down operation of the upper bead ring is started when the pressure in the tire vulcanizing bladder reaches 15 to 25 kPa.

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