JP2011021891A - Method and device for detecting metal wire of tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and device for detecting the metal wire of a tire capable of always precisely detecting the abnormal place at the end part position of the metal wire even in a tire different in specifications. <P>SOLUTION: The voltage corresponding to the distance from the outside of the tire 1 to the metal wire 4 is output over the whole periphery of the tire 1 by a first sensor 10 while the voltage corresponding to the distance from the outside of the tire 1 to the surface of the tire 1 is output over the whole periphery of the tire 1 by a second sensor 20 and it is determined whether a determined value, which is obtained by subtracting the average value over the whole periphery of the tire 1 of the difference between the output voltages of the first and second sensors 10 and 20 from the output voltage of the first sensor 10 is a predetermined determined reference value or above to detect the failure at the end part position of the metal wire. Accordingly, even if the output voltage of the first sensor 10 becomes large by the presence of another metal wire 7, the failure is detected without altering the determined reference value. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a tire metal wire detection method and apparatus for detecting an abnormality in the end position of a metal wire located in the vicinity of a surface layer in a tire.

  Generally, a pneumatic tire used for a passenger car or the like has a belt layer inside a tread portion, and a number of reinforcing metal wires are embedded in the belt layer. Since both ends of this metal wire are located in the vicinity of the surface layer of the shoulder portion, alignment of the metal wire is disturbed during molding of the unvulcanized tire or during vulcanization molding, and the ends of some of the metal wires are part of the belt layer. A tire may be manufactured in a state of being unevenly distributed outward.

  In such a case, if the end of the metal wire is exposed on the outer surface of the tire, it can be found by visual inspection, but even if the end of the metal wire is not exposed on the outer surface of the tire, If it is located outside, it may be exposed to the outside during use of the tire, so in the finished tire inspection process, check whether the end of the metal wire in the tire is in the proper position. There is a need to.

  Therefore, conventionally, there has been known a method in which an abnormal portion of the end position of the metal wire is detected by measuring the distance from the outside of the tire to the metal wire by the magnetic sensor over the entire circumference of the tire. (For example, refer to Patent Document 1 or 2).

  In this detection method, when the distance from the metal wire to the magnetic sensor becomes shorter, the output voltage of the magnetic sensor increases, so by determining whether there is a location where the output voltage is equal to or higher than a predetermined reference value, An abnormality in the end position of the metal wire is inspected.

JP 2005-148049 A JP 2007-7915 A

  By the way, in the finished tire inspection process, there are cases where a plurality of types of tires having different specifications are inspected. However, the position and density of the metal wire are often different depending on the type of tire, and portions other than the belt layer (for example, side walls) There is also a case where a metal reinforcing material is buried in the part). In such a case, since the output voltage of the magnetic sensor also varies depending on the type of tire, for example, in the case of a tire having a specification with a large number of metal wires or a tire having a metal reinforcing material in other parts, the magnetic sensor As a result, the output value of the sensor becomes large and erroneous detection is likely to occur, and the inspection cannot be performed with high accuracy. For this reason, in order to prevent erroneous detection, the determination reference value for the output voltage of the magnetic sensor has to be changed for each type of tire, and there is a problem that inspection efficiency is lowered.

  The present invention has been made in view of the above-mentioned problems, and the object of the present invention is to provide a tire that can always detect an abnormal position of an end position of a metal wire with high accuracy even if the tire has different specifications. An object of the present invention is to provide a metal wire detection method and apparatus.

  To achieve the above object, the present invention provides a tire metal wire detection method for detecting an end position abnormality of a metal wire located in the vicinity of a surface layer in a tire, according to a distance from the outside of the tire to the metal wire. The detected value is output over the entire circumference of the tire by the first sensor, and the detected value according to the distance from the outside of the tire to the surface of the tire is output over the entire circumference of the tire by the second sensor. By determining whether or not the value obtained by subtracting the average value over the entire tire circumference of the difference between the detection values of the first and second sensors from the detection value of the first sensor is greater than or equal to a predetermined determination reference value, An abnormality in the end position of the wire is detected.

  In order to achieve the above object, the present invention provides a tire metal wire detection device for detecting an abnormal position of an end portion of a metal wire located in the vicinity of a surface layer in a tire, and a distance from the outside of the tire to the metal wire. A first sensor that outputs a detection value corresponding to the entire circumference of the tire, and a second sensor that outputs a detection value corresponding to the distance from the outside of the tire to the tire surface over the entire circumference of the tire; A determination processing unit that determines whether or not a value obtained by subtracting an average value over the entire tire circumference of a difference between detection values of the first and second sensors from a detection value of the first sensor is equal to or greater than a predetermined determination reference value; It has.

  Accordingly, whether or not the determination value is equal to or greater than a predetermined determination reference value using a value obtained by subtracting the average value over the entire tire circumference of the difference between the detection values of the first and second sensors from the detection value of the first sensor. For example, even if the detection value of the first sensor is increased due to the presence of another metal wire, the magnitude of the determination value is the same as in the case of a tire that does not have other metal wires. Even in the case of a tire having another metal wire, detection can be performed without changing the determination reference value.

  According to the present invention, for example, when inspecting a tire of another specification having another metal wire, the determination reference value is changed even if the detection value of the first sensor is increased due to the presence of the other metal wire. Therefore, it is possible to always detect an abnormal portion of the end position of the metal wire with high accuracy regardless of the presence or absence of other metal wires. Thereby, even when inspecting a plurality of types of tires having different specifications, it is not necessary to change the determination reference value for each type of tire, and the inspection efficiency can be improved.

The principal part front view of the metal wire detection apparatus which shows one Embodiment of this invention Block diagram showing the configuration of the metal wire detection device The principal part enlarged front view of the metal wire detection apparatus which shows a 1st example of a detection The figure which shows the waveform of the voltage in the 1st detection example The principal part enlarged front view of the metal wire detection apparatus which shows the 2nd example of a detection

  FIG. 1 to FIG. 5 show an embodiment of the present invention, and the metal wire detection device shown in FIG. 1 is for detecting an abnormal portion of the end position of the metal wire located near the surface layer in the tire 1. It is.

  The tire 1 has a belt layer 3 inside the tread portion 2, and a number of reinforcing metal wires 4 are embedded in the belt layer 3. The metal wires 4 are arranged at intervals from each other so as to form a predetermined inclination angle with respect to the tire circumferential direction, and both ends thereof are located in the vicinity of the surface layer of the shoulder portion 5.

  The metal wire detection device of the present embodiment includes a first sensor 10 that outputs a detection value (voltage) according to the distance from the outside of the tire 1 to the metal wire 4 over the entire circumference of the tire 1, and the tire 1. A second sensor 20 that outputs a detection value (voltage) according to the distance from the outside to the tire surface over the entire circumference of the tire 1, and a sensor unit 30 to which the first and second sensors 10, 20 are attached. A first amplifier 40 that amplifies and outputs the output voltage of the first sensor 10, and a second amplifier 50 that amplifies and outputs the difference between the output voltages of the first and second sensors 10 and 20. And a determination processing unit 60 that determines the presence / absence of an abnormal end portion of the metal wire 4 based on the output voltages of the first and second amplifiers 40 and 50.

  The first sensor 10 is a well-known magnetic sensor, and outputs a voltage corresponding to the distance from the metal wire 4 to the first amplifier 40.

  The second sensor 20 is a known optical sensor using a laser or the like, and outputs a voltage corresponding to the distance from the tire surface to the second amplifier 50.

  The sensor unit 30 includes a substrate 31 fixed so that the first and second sensors 10 and 20 face each other in the same direction, and a roller 32 attached to the substrate 31, and the substrate 31 is interposed via a support member 33. It is movably provided by a drive unit (not shown). The sensor unit 30 is configured such that a predetermined interval is maintained between the first and second sensors 10 and 20 and the tire surface when the roller 32 contacts the tire surface, and the tire 1 When rotating in the direction, the roller 32 rotates while being in contact with the tire surface, and detection by the first and second sensors 10 and 20 is continuously performed in the tire circumferential direction.

  The first amplifier 40 receives the voltage output from the first sensor 10, and outputs the voltage obtained by amplifying this voltage to the determination processing unit 60 as a waveform over the entire circumference of the tire 1. ing.

  The second amplifier 50 receives the voltages output from the first sensor 10 and the second sensor 20, respectively, and outputs the voltage obtained by amplifying the difference between these voltages to the determination processing unit 60. It has become.

  The determination processing unit 60 includes an A / D converter, a comparator, a microcomputer, and the like, averages the voltage value output from the second amplifier 50 over the entire circumference of the tire, and outputs it from the first amplifier 40. The presence / absence of an abnormal portion of the end of the metal wire 4 is determined by comparison with the voltage value. The determination processing unit 60 outputs a “normal” determination signal when it is determined that there is no abnormal end portion of the metal wire 4, and “abnormal” when it is determined that there is an abnormal end portion of the metal wire 4. The position signal (rotation angle) in the tire circumferential direction of the abnormal portion is output.

  In the metal wire detection device configured as described above, for example, the sensor unit 30 is moved to the shoulder portion 5 of the tire held by the uniformity tester, and the roller 32 of the sensor unit 30 is brought into contact with the tire surface, Measurements are made simultaneously when rotating the tire with a uniformity testing machine. At this time, when the measurement over the entire circumference of the tire is completed, a determination signal is output from the determination processing unit 60.

In this case, in the determination processing unit 60, the voltage output from the first sensor 10 is An (n = 1, 2, 3,...), And the voltage output from the second sensor 20 is Bn (n = 1, 1. 2, 3,...), The average value of the difference in voltage output from the first and second sensors 10, 20 over the entire tire circumference (A−B), and the voltage from the output voltage An of the first sensor 10. A value obtained by subtracting the average value (A−B) of the differences is set as a determination value Cn (n = 1, 2, 3,...), And the determination value Cn is set to
Cn = An- (AB) (1)
Then, by comparing the determination value Cn with a predetermined determination reference value D, if the determination value Cn is greater than or equal to the determination reference value D, it is determined as “abnormal”. In this case, since the roller 32 of the sensor unit 30 contacts the tire surface, a predetermined distance is maintained from the second sensor 20 to the tire surface. Therefore, the output voltage Bn of the second sensor 20 is applied to the entire tire circumference. It becomes almost constant throughout. Therefore, if the output voltage An of the first sensor 10 is substantially the same as the average value A, the determination value Cn is substantially equal to the average value B of the output voltage of the second sensor 20 from the equation (1). The determination reference value D can be set in advance to a predetermined voltage higher than the output voltage of the second sensor 20.

  That is, as shown in the first detection examples of FIGS. 3A and 4A, when the metal wire 4 is in an appropriate position, the determination value Cn is smaller than the determination reference value D. The determination processing unit 60 determines “normal”. Further, as shown in FIGS. 3B and 4B, when a part of the metal wire 4 is exposed to the outside of the tire 1, the output value of the first sensor 10 at the location θn. Since An increases rapidly, the determination value Cn becomes equal to or greater than the determination reference value D, and the determination processing unit 60 determines “abnormal”. Further, even when the metal wires 4 are not exposed to the outside of the tire 1, as shown in FIGS. 3 (c) and 4 (c), some of the metal wires 4 are outside the tire 1 from the proper positions. If the determination value Cn of the location θn is equal to or greater than the determination reference value D, the determination processing unit 60 determines “abnormal”.

  Here, as shown in the second detection example of FIG. 5, in addition to the metal wires 4 of the belt layer 3, when other metal wires 7 that reinforce the sidewall portions 6 are embedded, the other metal wires 7. The output voltage of the first sensor 10 increases due to the presence of the output, but in the detection method of the present embodiment, as described above, the output of the first and second sensors 10 and 20 from the output voltage An of the first sensor 10. Since the value obtained by subtracting the average value (A−B) of the voltage difference is used as the judgment value Cn, the magnitude of the judgment value Cn is the same as in the first detection example, and the tire having the other metal wires 7 is used. On the other hand, it is not necessary to change the determination reference value D.

For example, in the first detection example, when the average value A of the output voltage of the first sensor 10 is 3V and the output voltage of the second sensor 20 is 2V, the output voltage An of the first sensor 10 is the average value A. In the case of the same 3V,
Cn = 3- (3-2) = 2V (2)
When the output voltage An of the first sensor 10 is 3.5 V, which is larger than the average value A,
Cn = 3.5- (3-2) = 2.5V (3)
It becomes.

In the second detection example, when the average value A of the output voltage of the first sensor 10 is 5 V and the output voltage of the second sensor 20 is 2 V, the output voltage An of the first sensor 10 is the average value A. In case of 5V same as
Cn = 5- (5-2) = 2V (4)
When the output voltage An of the first sensor 10 is 5.5 V, which is larger than the average value A,
Cn = 5.5- (5-2) = 2.5V (5)
It becomes.

  Therefore, even if the output voltage An of the first sensor 10 is increased due to the presence of another metal wire 7 as in the second detection example, the magnitude of the determination value Cn is not different from that in the first detection example. In the second detection example, detection can be performed without changing the determination reference value D.

  Thus, according to the present embodiment, a voltage corresponding to the distance from the outside of the tire 1 to the metal wire 4 is output over the entire circumference of the tire 1 by the first sensor 10, and from the outside of the tire 1. A voltage corresponding to the distance to the tire surface is output over the entire circumference of the tire 1 by the second sensor 20, and the output voltage An of the first sensor 10 is output from the output voltage of the first and second sensors 10, 20. The abnormality of the end position of the metal wire 1 is detected by determining whether or not the determination value Cn obtained by subtracting the average value of the difference over the entire tire circumference is greater than or equal to a predetermined determination reference value D. Therefore, even if the output voltage of the first sensor 10 increases due to the presence of another metal wire 7, it can be detected without changing the determination reference value D, and the metal regardless of the presence or absence of the other metal wire 7. Abnormal location of end position of wire 4 Can always be detected with high accuracy. Thereby, even when inspecting a plurality of types of tires having different specifications, it is not necessary to change the determination reference value D for each type of tire, and the inspection efficiency can be improved.

  In the above embodiment, the case where the metal wires 7 of the sidewall portions 6 are provided in addition to the metal wires 4 of the belt layer 3 is exemplified, but the number, outer diameter size, arrangement, and the like of the metal wires 4 of the belt layer 3 are different. Thus, even when the output voltage of the first sensor 10 changes, the same effect as described above can be obtained.

  In the above-described embodiment, the determination reference value D is set to a predetermined voltage higher than the output voltage of the second sensor 20, but the determination reference value D is not fixed and the second If the average value of the output voltage of the sensor 20 over the entire circumference of the tire is calculated for each detection operation, and a value obtained by adding a predetermined voltage thereto is set as the determination reference value D each time, the tire surface Even when the distance from the vehicle fluctuates depending on the shape of the tire or the like, there is an advantage that the detection accuracy is not lowered. Thereby, for example, the sensor unit 30 can be brought close to the tire surface in a non-contact manner without using the roller 32.

  DESCRIPTION OF SYMBOLS 1 ... Tire, 4, 7 ... Metal wire, 10 ... 1st sensor, 20 ... 2nd sensor, 60 ... Determination process part.

Claims (5)

In the tire metal wire detection method for detecting an abnormality in the end position of the metal wire located near the surface layer in the tire,
The detection value according to the distance from the outside of the tire to the metal wire is output over the entire circumference of the tire by the first sensor, and the detection value according to the distance from the outside of the tire to the surface of the tire is second. The sensor outputs the entire circumference of the tire,
By determining whether or not a value obtained by subtracting the average value over the entire tire circumference of the difference between the detection values of the first and second sensors from the detection value of the first sensor is equal to or greater than a predetermined determination reference value, the metal wire An abnormality in the end position of the tire is detected. The tire metal wire detection method according to claim 1, wherein a value obtained by adding a predetermined value to a detection value of the second sensor detected for each detection operation is set as the determination reference value each time. . In the tire metal wire detection device for detecting an abnormality in the end position of the metal wire located near the surface layer in the tire,
A first sensor that outputs a detection value according to a distance from the outside of the tire to the metal wire over the entire circumference of the tire;
A second sensor that outputs a detection value according to the distance from the outside of the tire to the tire surface over the entire circumference of the tire;
A determination processing unit that determines whether or not a value obtained by subtracting an average value over the entire tire circumference of a difference between detection values of the first and second sensors from a detection value of the first sensor is equal to or greater than a predetermined determination reference value; A tire metal wire detection device comprising: a tire; The metal wire detection device for a tire according to claim 3, wherein a magnetic sensor is used as the first sensor. 5. The tire metal wire detection device according to claim 3, wherein an optical sensor is used as the second sensor.

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