JP4438503B2 - Tire failure detection device and detection method - Google Patents

Description

  The present invention relates to a device and a method for detecting a failure of a rotating tire in a tire durability test, and more particularly to a tire failure detection device and a detection method capable of accurately detecting a tire failure.

  In the indoor tire endurance test, the endurance test is performed while running the tire on the outer periphery of the drum. However, when a failure occurs in the tire, it is desired to immediately detect the failure and end the test. That is, if the durability test is continued in a state where a tire failure has occurred, the tire may burst.

  Conventionally, as a tire failure detection device, a limit rod formed by connecting a large number of metal pieces is arranged along the outer edge of the tire, and the displacement of the limit rod when the part swollen due to tire failure such as separation contacts the limit rod Has been proposed (see, for example, Patent Document 1).

However, in a device that detects a tire failure based on the displacement of the limit rod, the detection accuracy is low, so the tire may burst. Moreover, in the conventional tire failure detection device, if the detection accuracy is increased to detect a slight bulge due to a tire failure, it becomes difficult to find the failure position after the tire durability test. That is, when the tire cools, the bulge returns to the original state, and the failure position cannot be determined. For this reason, in addition to improving the detection accuracy, it is also required to specify the fault location.
JP-A-57-93230

  An object of the present invention is to provide a tire failure detection device and a detection method capable of improving the detection accuracy of a tire failure.

  A further object of the present invention is to provide a tire failure detection device and a detection method that improve the accuracy of detection of a tire failure and that can identify the failure position.

In order to achieve the above object, a tire failure detection device of the present invention is a device for detecting a failure of a rotating tire in a tire durability test, and a portion that swells due to the failure of the tire at a position facing the outer surface of the tire. the contact body in contact with installation and, by attaching a shock sensor for converting a shock to the electrical signal to the contact body, Ru provided a determining circuit failure of the tire based on the electrical signal from the impact sensor On the other hand, a phase detection device that detects a reference position in the circumferential direction of the tire and generates a pulse signal is provided, and the circumferential direction of the tire is based on the electrical signal from the impact sensor and the pulse signal from the phase detection device. An arithmetic circuit for calculating the failure position is provided .

A tire failure detection method of the present invention for achieving the above object is a method for detecting a failure of a rotating tire in a tire durability test, and swells due to the failure of the tire at a position facing the outer surface of the tire. While installing a contact body so as to come into contact with the body part, an impact sensor for converting an impact into an electrical signal is attached to the contact body, while determining a failure of the tire based on the electrical signal from the impact sensor , A reference position in the circumferential direction of the tire is detected to generate a pulse signal, and a fault position in the circumferential direction of the tire is calculated based on an electrical signal from the impact sensor and the pulse signal. is there.

  In the present invention, a contact body including an impact sensor that converts an impact into an electrical signal is installed at a position facing the outer surface of the tire, and a tire failure is determined based on the electrical signal from the impact sensor. When such an electrical signal from the impact sensor is used for determining a tire failure, it is possible to accurately measure the strength and frequency of contact between the tire and the contact body based on the electrical signal. The detection accuracy can be greatly improved.

Furthermore, in the present invention, a phase detection device that detects a reference position in the circumferential direction of the tire and generates a pulse signal is provided. to be provided an arithmetic circuit for calculating the position. By using the electric signal from the impact sensor and the pulse signal from the phase detection device, the failure position in the tire circumferential direction can be specified. Moreover, it is preferable to arrange | position the several detection unit containing a contact body and an impact sensor in the range from one bead part of a tire through a tread part to the other bead part. Thereby, the failure position in the tire meridian direction can be specified. As the impact sensor, an accelerometer or a load cell is preferably used.

  Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings.

  1A to 1C show a detection unit of a tire failure detection apparatus according to an embodiment of the present invention. 1A shows a detection unit A for detecting a failure in a tread portion, and FIG. 1B shows a detection unit B for detecting a failure in one bead portion and a sidewall portion. (C) shows the detection unit C for detecting a failure of the other bead part and the side wall part. Note that T is a tire mounted in a tire durability test.

  As shown in FIG. 1A, the detection unit A includes a support portion 1A, an arm portion 2A that can extend and contract in the tire radial direction from the support portion 1A, and a rod-like contact body 3A that is attached to the arm portion 2A. And an impact sensor 4A. The contact body 3A is disposed at a position facing the outer surface of the tread portion of the tire T so as to be slightly separated from the outer surface, and comes into contact with a portion swelled due to a failure of the tire T. A wiring 5A is connected to the impact sensor 4A.

  As shown in FIG. 1B, the detection unit B includes a support portion 1B, an arm portion 2B that can extend and contract in the tire radial direction from the support portion 1B, and a displacement in the tire axial direction with respect to the arm portion 2B. The rod-shaped contact body 3B attached to the arm portion 2B and the impact sensor 4B fixed to the arm portion 2B are provided. The contact body 3B is disposed at a position facing one bead portion of the tire T and the outer surface of the sidewall portion so as to be slightly separated from the outer surface, and comes into contact with a portion swelled due to a failure of the tire T. . A wiring 5B is connected to the impact sensor 4B.

  As shown in FIG. 1C, the detection unit C includes a support portion 1C, an arm portion 2C that can extend and contract in the tire radial direction from the support portion 1C, and a displacement in the tire axial direction with respect to the arm portion 2C. A rod-shaped contact body 3C attached to the arm portion 2C and an impact sensor 4C fixed to the arm portion 2C. The contact body 3C is disposed at a position facing the other bead portion of the tire T and the outer surface of the sidewall portion so as to be slightly separated from the outer surface, and comes into contact with a portion swelled due to a failure of the tire T. . A wiring 5C is connected to the impact sensor 4C.

  In the detection units A to C, the impact sensors 4A to 4C convert impacts applied to the contact bodies 3A to 3C into electric signals, and for example, an accelerometer or a load cell can be used. An accelerometer is particularly preferable. The electrical signals from the impact sensors 4A to 4C accurately reflect the strength and frequency of contact between the tire T and the contact bodies 3A to 3C. These detection units A to C can be arranged at arbitrary positions in the tire circumferential direction.

  The detection units A to C have a structure in which their constituent members slide relative to each other, because this corresponds to various tire sizes.

  FIG. 2 shows a tire failure detection device according to an embodiment of the present invention. In FIG. 2, the tire T is supported so as to be rotatable about the central axis, and rolls on the outer peripheral surface of the drum D of the tire durability tester. And the above-mentioned detection units A-C are arrange | positioned in the same position of the tire circumferential direction. Electrical signals from the impact sensors 4A to 4C of the detection units A to C are supplied to the control circuit 11 of the tire durability tester via the wirings 5A to 5C.

  On the other hand, a reference position X in the circumferential direction is set on the tire T, and a phase detection device 7 that detects the reference position X and generates a pulse signal is installed. This phase detection device 7 generates one pulse for each turn of the tire T. The configuration of the phase detection device 7 is not particularly limited, and an optical or mechanical device can be used. A pulse signal from the phase detector 7 is supplied to the control circuit 11 via the wiring 8.

  The control circuit 11 includes a determination circuit 12 and an arithmetic circuit 13. The determination circuit 12 determines the failure of the tire T based on the electrical signals from the impact sensors 4A to 4C. That is, it is determined that a failure has occurred in the tire T when any one of the electric signals from the impact sensors 4A to 4C exceeds a preset threshold value. In response to the result, the control circuit 11 ends the tire durability test. In order to ensure accuracy, the tire endurance test may be terminated after receiving an electrical signal exceeding the threshold several times. For example, the threshold value may be set to a value of 200% with respect to the average value (that is, noise component) of the voltage of the electric signal for 10 minutes after the test starts. On the other hand, the arithmetic circuit 13 calculates a fault position in the tire circumferential direction based on the electrical signals from the impact sensors 4A to 4C and the pulse signal from the phase detector 7 as will be described later.

  In the tire failure detection device described above, when the outer surface of the tire T swells due to a failure such as separation in the tire durability test and comes into contact with the contact bodies 3A to 3C, the impact sensors 4A to 4C convert the impact at the time of contact into electrical signals. The failure of the tire T is determined based on the electrical signal. Thereby, a tire failure can be detected with high accuracy, and a burst of the tire T can be prevented. Further, since a plurality of detection units A to C including contact bodies 3A to 3C and impact sensors 4A to 4C are arranged in a range from one bead portion of the tire T to the other bead portion through the tread portion. The failure position in the tire meridian direction can be specified. Further, the failure position in the tire circumferential direction can be specified based on the electrical signals from the impact sensors 4A to 4C and the pulse signal from the phase detection device 7.

  FIG. 3 is a graph showing the waveform of the electrical signal from the impact sensor in the tire failure detection apparatus of FIG. 2 over time. In FIG. 3, the horizontal axis indicates time, the vertical axis indicates the voltage of the electric signal in each detection unit, the broken line extending in the horizontal axis direction is the threshold value of each electric signal, and the broken line extending in the vertical axis direction indicates the pulse signal. It is the timing that occurred. The test results in FIG. 3 are obtained when all the detection units A to C are installed at a position 180 ° from the reference position X and a tire having an outer peripheral length of about 3 m is rotated at a speed of 80 km / h. Accordingly, the time between pulses is 0.135 seconds, and 0.000375 seconds corresponds to 1 ° in the tire circumferential direction.

  From FIG. 3, it can be seen that the tread portion observed by the detection unit A is swollen. The impact determined from the electrical signal occurs 0.01875 seconds after the pulse signal, and this delay corresponds to 50 ° from the above conversion relationship. Further, since the position of the detection unit A is at a position shifted by 180 ° from the reference position X (0 °), it can be seen that the detection unit A bulges in the vicinity of a position 230 ° from the reference position X. In other words, the failure position is about 230 ° from the reference position X. In FIG. 3, the detection unit B also detects an impact, but since this impact appears only once, it can be determined as a malfunction or noise.

  FIG. 4 shows a tire failure detection device according to another embodiment of the present invention. In the present embodiment, only the arrangement of the detection units is changed from the above embodiment. In FIG. 4, the detection unit A is arranged at a position 180 ° from the reference position X, the detection unit B is arranged at a position 90 ° from the reference position X, and the detection unit C is arranged at a position 270 ° from the reference position X. Has been.

  FIG. 5 is a graph showing the waveform of the electrical signal from the impact sensor in the tire failure detection apparatus of FIG. 4 over time. In FIG. 5, the horizontal axis indicates time, the vertical axis indicates the voltage of the electric signal in each detection unit, and the broken line extending in the vertical axis direction indicates the timing at which the pulse signal is generated. It is also possible to specify the failure location from the test result of FIG.

  FIG. 6 shows a main part of a tire failure detection device according to still another embodiment of the present invention. In FIG. 6, a plurality of detection units 20 </ b> A to 20 </ b> E are arranged in a range from one bead portion of the tire T to the other bead portion through the tread portion. These detection units 20A to 20E include support portions 21A to 21E, arm portions 22A to 22E, contact bodies 23A to 23E, impact sensors 24A to 24E, and wirings 25A to 25E. Thus, by increasing the number of detection units arranged along the tire meridian direction, the failure position in the tire meridian direction can be specified more accurately.

  FIGS. 7A and 7B show the main part of a tire failure detection device according to still another embodiment of the present invention. FIG. 7A shows a detection unit 30A for detecting a failure in one bead portion and the sidewall portion in addition to the tread portion, and FIG. 7B shows the other bead portion and the sidewall in addition to the tread portion. This shows a detection unit 30B for detecting a failure of the unit.

  As shown in FIG. 7A, the detection unit 30A includes a support portion 31A, an arm portion 32A that can extend and contract in the tire radial direction from the support portion 31A, and an arm portion 32A that extends along the tread portion. Attached rod-like contact body 33A, a rod-like contact body 36A attached to the contact body 33A so as to extend along the one bead portion and the side wall portion and displaceable in the tire axial direction, and an arm portion An impact sensor 34A attached to 32A and a wiring 35A connected to the impact sensor 34A are provided.

  As shown in FIG. 7B, the detection unit 30B includes a support portion 31B, an arm portion 32B that can extend and contract in the tire radial direction from the support portion 31B, and an arm portion 32B that extends along the tread portion. An attached rod-shaped contact body 33B, a rod-shaped contact body 36B attached to the contact body 33B so as to be displaceable in the tire axial direction so as to extend along the other bead portion and the sidewall portion, and an arm portion An impact sensor 34B attached to 32B and a wiring 35B connected to the impact sensor 34B are provided.

  In the above embodiment, when only the electric signal from the impact sensor 34A of the detection unit 30A notifies the tire failure, it can be seen that the failure position exists in one bead portion and the sidewall portion observed by the detection unit 30A. . Further, when only the electric signal from the impact sensor 34B of the detection unit 30B notifies the tire failure, it can be seen that the failure position exists in the other bead portion and the sidewall portion observed by the detection unit 30B. Furthermore, when the electrical signals from the impact sensors 34A and 34B of the detection units 30A and 30B both notify the tire failure, it can be seen that the failure position exists in the tread portion observed by both the detection units 30A and 30B.

  FIG. 8 shows a main part of a tire failure detection device according to still another embodiment of the present invention. In FIG. 8, a single detection unit 40 </ b> A is disposed in a range from one bead portion of the tire T to the other bead portion through the tread portion.

  As shown in FIG. 8, the detection unit 40A is attached to the arm portion 42A so as to extend along the tread portion, the support portion 41A, the arm portion 42A that can extend and contract in the tire radial direction from the support portion 41A. A rod-shaped contact body 43A, a rod-shaped contact body 46A attached to the contact body 43A so as to be displaceable in the tire axial direction so as to extend along one bead portion and the sidewall portion, and the other bead portion A rod-like contact body 49A attached to the contact body 43A so as to be displaceable in the tire axial direction so as to extend along the sidewall portion, an impact sensor 44A attached to the arm portion 42A, and an impact sensor 44A. And a connected wiring 45A.

  In the above embodiment, it is possible to accurately detect a tire failure, but it is not possible to specify a failure position in the tire meridian direction. However, it is possible to specify the failure position in the tire circumferential direction. Generally, when a tire is disassembled and a failure is verified, the tire is cut along the tire meridian direction, and therefore it is useful to specify the failure position in the tire circumferential direction.

  FIG. 9 shows a main part of a tire failure detection device according to still another embodiment of the present invention. In FIG. 9, a single detection unit 50 </ b> A for observing a failure from the tread portion to the shoulder portion is arranged for the tire T.

  As shown in FIG. 9, the detection unit 50A is attached to the arm portion 52A so as to extend from the support portion 51A, the arm portion 52A that can expand and contract in the tire radial direction from the support portion 51A, and from the tread portion to the shoulder portion. The bar-shaped contact body 53A, the impact sensor 54A attached to the arm portion 52A, and the wiring 55A connected to the impact sensor 54A are provided. This device is effective when a failure is expected to occur in the range from the tread portion to the shoulder portion.

  FIG. 10 shows a main part of a tire failure detection device according to still another embodiment of the present invention. In FIG. 10, a pair of detection units 60 </ b> A and 60 </ b> B for observing a failure of the bead portion are disposed on the tire T.

  As shown in FIG. 10, the detection unit 60A is attached to the arm portion 62A so as to extend along the support portion 61A, the arm portion 62A that can extend and contract in the tire axial direction from the support portion 61A, and one bead portion. The bar-shaped contact body 63A, an impact sensor 64A attached to the support portion 61A, and a wiring 65A connected to the impact sensor 64A are provided. On the other hand, the detection unit 50B includes a support portion 61B, an arm portion 62B that can expand and contract in the tire axial direction from the support portion 61B, and a rod-like contact that is attached to the arm portion 62B so as to extend along the other bead portion. It includes a body 63B, an impact sensor 64B attached to the support portion 61B, and a wiring 65B connected to the impact sensor 64B. This apparatus is effective when a failure is expected to occur in the bead portion.

  11 and 12 show the main part of a tire failure detection device according to still another embodiment of the present invention. This embodiment exemplifies the arrangement of contact bodies when a large number of detection units are provided in a range from one bead portion of the tire T to the other bead portion through the tread portion. Therefore, description is abbreviate | omitted about structures other than a contact body.

  As shown in FIGS. 11 and 12, the twelve contact bodies 73A to 73L are arranged every 30 ° around the tire rotation axis. The contact bodies 73A to 73D that observe the failure of the tread portion are arranged at positions shifted from each other in the tire axial direction, and the contact bodies 73E to 73H that observe the failure of the one bead portion and the sidewall portion are mutually in the tire radial direction. The contact bodies 73I to 73L, which are arranged at positions deviated from each other and observe the failure of the other bead part and the side wall part, are arranged at positions deviated from each other in the tire radial direction. Thus, by increasing the number of contact bodies and arranging these many contact bodies so that the failure observation areas are shifted from each other, the failure position in the tire meridian direction can be specified more accurately.

The detection unit of the tire failure detection apparatus which consists of embodiment of this invention is shown, (a)-(c) is a front view of each detection unit. It is a side view which shows the tire failure detection apparatus which consists of embodiment of this invention. It is a graph which shows the waveform of the electric signal from the impact sensor in the tire failure detection apparatus of FIG. 2 with time. It is a side view which shows the tire failure detection apparatus which consists of other embodiment of this invention. It is a graph which shows the waveform of the electric signal from the impact sensor in the tire failure detection apparatus of FIG. 4 with time. It is a front view which shows the principal part of the tire failure detection apparatus which consists of further another embodiment of this invention. The principal part of the tire failure detection apparatus which consists of further another embodiment of this invention is shown, (a), (b) is a front view of each detection unit. It is a front view which shows the principal part of the tire failure detection apparatus which consists of further another embodiment of this invention. It is a front view which shows the principal part of the tire failure detection apparatus which consists of further another embodiment of this invention. It is a front view which shows the principal part of the tire failure detection apparatus which consists of further another embodiment of this invention. It is a side view which shows the principal part of the tire failure detection apparatus which consists of further another embodiment of this invention. It is a front view which shows the principal part of the tire failure detection apparatus of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1A-1C Support part 2A-2C Arm part 3A-3C Contact body 4A-4C Impact sensor 5A-5C Wiring 7 Phase detector 8 Wiring 11 Control circuit 12 Judgment circuit 13 Arithmetic circuit A-C detection unit T Tire X Reference position

Claims (6)

An apparatus for detecting a failure of a rotating tire in a tire durability test, wherein a contact body is installed at a position facing the outer surface of the tire so as to contact a portion swollen due to the failure of the tire, and the contact body is subjected to an impact. the annexed impact sensor for converting into electric signals, while based on the electrical signal from the impact sensor Ru provided a determining circuit failure of the tire, to detect the reference position in the circumferential direction of the tire pulse A tire failure detection device provided with a phase detection device for generating a signal, and provided with an arithmetic circuit for calculating a failure position in the circumferential direction of the tire based on an electric signal from the impact sensor and a pulse signal from the phase detection device. The tire failure detection device according to claim 1 , wherein a plurality of detection units including the contact body and the impact sensor are arranged in a range from one bead portion of the tire to the other bead portion through the tread portion. Tire failure detection device according to any one of claims 1-2 wherein the impact sensor is an accelerometer or load cell. A method for detecting a failure of a rotating tire in a tire endurance test, wherein a contact body is installed at a position facing the outer surface of the tire so as to contact a portion swelled due to the failure of the tire, and the contact body is subjected to an impact. Is attached to an impact sensor to determine the failure of the tire based on the electrical signal from the impact sensor , while detecting a reference position in the circumferential direction of the tire to generate a pulse signal, A tire failure detection method for calculating a failure position in the circumferential direction of the tire based on an electrical signal from the impact sensor and the pulse signal . The tire failure detection method according to claim 4 , wherein a plurality of detection units including the contact body and the impact sensor are arranged in a range from one bead portion of the tire through a tread portion to the other bead portion. The tire failure detection method according to any one of claims 4 to 5 , wherein the impact sensor is an accelerometer or a load cell.

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