KR20210063804A - Tire test machine - Google Patents

Abstract

Disclosed is a tire test machine that can detect early defects in a tire and stop a test before an accident occurs. The tire test machine includes: a test drum capable of rotating in contact with a tire; a spindle unit coupled to the wheel of the tire; a carrier moving the spindle unit; a measuring instrument that measures vibration signals generated during a tire driving test; and a controller that classifies the measurement vibration signals measured by the measuring instrument into normal vibration signals and defective vibration signals according to vibration signal states when the tire is in a normal or defective state and controls the speed of the test drum and the movement of the carrier based on the normal vibration signals and the defective vibration signals.

Description

Tire testing machine {TIRE TEST MACHINE}

The present invention relates to a tire testing machine. More particularly, it relates to a tire testing machine capable of detecting defects at an early stage during testing of tire durability performance.

In general, in a tire driving test, a tire tester is used to measure performance such as a change in physical properties of a tire according to a driving speed of a vehicle and a change in load during driving.

The tire test drum is connected to a separate driving device such as a motor and rotates at various speeds while rotating the tire in contact with it to test the tire at various driving speeds. In addition, the load condition applied to the tire can be controlled by moving the carriage to the drum by a servomotor, and PLC is responsible for controlling the test condition.

For example, in order to detect the timing of a tire accident during a driving test, in the related art, a seal is connected close to the upper part of the tire tread, and a limit device is connected to the end of the seal, so that tire fragments touch the seal due to an accident. By the operation of the limit device, the PLC removes the load from the carriage and controls the drum to stop.

However, in the case of a conventional tire tester, an accident does not occur based on a certain standard because the position for connecting the seal is different for each operator and the tension of the seal is different. And because the accident pattern is different, the tire bursts and the debris flies off, causing great damage to people working nearby. In addition, due to the time difference between sensor detection and servomotor stop when a burst occurs, the rim and drum of the tire momentarily come into contact, which may damage the testing machine and cause a fire due to high speed and high load.

In order to solve this problem, in the past, a "tire burst detection device of a tire tester (Korean Patent No. 10-0526692)" that detects an accident time by installing a burst detection device on a tire spindle has been proposed. However, even with this prior art, it is difficult to detect the initial defect of the tire, and it is not easy to stop the test before an accident occurs.

Patent Literature: Domestic Registered Patent No. 10-0526692 (Registered on October 31, 2005)

An object of the present invention is to solve the above problems, and to provide a tire testing machine capable of stopping the test before an accident occurs by detecting initial defects of the tire.

The configuration of the present invention includes a test drum rotatable in contact with the tire; a spindle unit coupled to the wheel of the tire; a carrier for moving the spindle unit; a measuring instrument that measures a vibration signal generated during a tire driving test; and among the measured vibration signals measured by the instrument, classify into a normal vibration signal and a defective vibration signal according to the vibration signal state when the tire is in a normal or defective state, and through the normal vibration signal and the defective vibration signal, the test drum It may include a controller for controlling the speed and movement of the carrier.

At this time, the controller can measure the vibration signal until the accident through the ECE-R30 High Speed test.

In addition, the controller divides the normal data sample immediately after the speed of the tire is increased and the defective data sample before the accident into two groups, and then substitutes the normal data sample and the defective data sample into the characteristic factors, respectively, Using the T-Test, which is an index that separates the two groups, ranks each characteristic factor, selects a characteristic factor included in the upper certain number range, and then selects a specific factor from a normal data sample and a defective data sample It is possible to compare the distribution between the characteristic factors of

In addition, the controller selects the distribution of each characteristic factor as a normal region without defects and a defective region in which defects occur, and calculates a distribution map in which a virtual dividing line is created in the region between the selected normal region and the defective region. , when the characteristic factor of the newly measured vibration signal is distributed in the normal region based on the dividing line of the calculated distribution map, it is determined as the normal vibration signal, and when distributed in the defective region, it can be determined as the defective vibration signal.

In addition, the controller acquires a normal data sample immediately after the tire speed is increased and a defect data sample before the accident through the ECE-R30 High Speed test, which can test when an accident occurred due to an initial defect. can do.

Embodiments of the present invention have the effect that the durability of the tire can be effectively improved by recognizing a portion where the durability of the tire is weak and supplementing the portion of the tire.

In addition, the present invention has the effect that when a tire accident occurs, a safety accident in which debris is blown to nearby workers can be prevented in advance, and the time of occurrence of a defect can be consistently maintained by determining the time of the initial accident.

In addition, since the present invention can prevent the tester from being damaged by rotating the drum and the rim of the tester, it has the effect of saving a lot of money in terms of maintenance and management of the tester.

1 is a configuration diagram illustrating a tire testing machine according to an embodiment of the present invention.
2 is a diagram illustrating a control flow of a tire testing machine according to an embodiment of the present invention.
3 is a graph showing the vibration signal of a tire according to time through an ECE-R30 High Speed test in a tire tester according to an embodiment of the present invention.
4 is a graph showing the distribution of raw data of the top two characteristic factors according to the tee test results in the tire testing machine according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, the configuration and operation according to the embodiment of the present invention will be described in detail. The following description is one of several aspects of the present invention that is claimable, and the following description may form a part of the detailed description of the present invention. However, in describing the present invention, detailed descriptions of known configurations or functions may be omitted for clarity of the present invention.

The present invention is capable of making various changes and may include various embodiments, and specific embodiments are illustrated in the drawings and described in the detailed description. However, this is not intended to limit the present invention to a specific embodiment, it should be understood to include all changes, equivalents, or substitutes included in the spirit and scope of the present invention.

In addition, terms including an ordinal number such as 1st, 2nd, etc. may be used to describe various components, but the components are not limited by these terms. These terms are only used for the purpose of distinguishing one component from another. When an element is referred to as being'connected' or'connected' to another element, it is understood that it may be directly connected or connected to the other element, but other elements may exist in the middle. It should be. The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise.

1 is a block diagram illustrating a tire testing machine according to an embodiment of the present invention, FIG. 2 is a diagram illustrating a control flow of the tire testing machine according to an embodiment of the present invention, and FIG. 3 is an embodiment of the present invention In the tire testing machine according to the example, it is a graph showing the vibration signal of the tire over time through the ECE-R30 High Speed test, and FIG. 4 is the top 2 according to the tee test results in the tire testing machine according to an embodiment of the present invention. It is a graph showing the distribution of raw data of the characteristic factors of dogs.

1 to 4 , the tire testing machine according to an embodiment of the present invention includes a test drum 100 , a spindle unit 200 , a carrier 300 , a measuring instrument 400 , and a controller 500 . may include

Specifically, the test drum 100 may test the tire T at various driving speeds by rotating the tire T while in contact with the tire. The test drum 100 may be connected to a separate driving device such as a motor.

The spindle unit 200 may include a spindle coupled to the wheel of the tire, and a spindle cover covering the spindle.

The carrier 300 may apply a load to the tire T by moving the spindle unit 200 . The carrier 300 may include a moving device (eg, a carrier table, a servomotor, etc.) capable of moving the tire T in a direction to approach or leave the test drum 100 . The tire T may be in close contact with the test drum 100 by the carrier 300 or may be separated from the drum. At this time, the relative load of the test drum 100 applied to the tire T may change.

The measuring instrument 400 may measure a vibration signal generated during a tire driving test. The vibration signal measured by the instrument 400 may be applied to the controller 500 .

As the instrument 400, an acceleration sensor attachable to the spindle axis may be used. In the present embodiment, an acceleration sensor is used as the measuring instrument 400 , but is not limited thereto, and various types of measuring equipment capable of measuring a vibration signal generated during a tire driving test may be used as the measuring instrument 400 .

The controller 500 may receive a measurement vibration signal from the measuring instrument 400 . The controller 500 may classify a vibration signal when the tire is in a normal or defective state among the measured vibration signals measured by the measuring instrument 400 into a normal vibration signal and a defective vibration signal.

To this end, the controller 500 may convert the measured vibration signal measured by the measuring instrument 400 into a characteristic factor that can be classified as normal or defective. In this case, the characteristic factor can be calculated through Table 1 below.

Table 1 is an equation for converting a measured vibration signal into a characteristic factor, and may be various equations capable of classifying a vibration signal as a feature capable of classifying a defect. For example, P1 is the mean, P2 is the variance, P3 is the maximum value, and P4 is the root mean square (RMS). Since the remaining equations (P5 to P20) are typical equations, a detailed description thereof will be omitted. These formulas (P1 to P20) are listed as a list of characteristic factors that are freely combined, and it goes without saying that in addition to these formulas, more can be created and applied by the user.

[Table 1]

The controller 500 may determine whether the converted characteristic factor satisfies a preset reference range through Table 1 . At this time, through the ECE-R30 High Speed test, which can test the time when an accident occurred due to an initial defect, the controller 500 collects the normal data sample immediately after the tire speed increases and the defect data sample before the accident. can be obtained

For example, the controller 500 may divide the normal data sample immediately after the speed of the tire is increased and the defective data sample before the accident into two groups, and then substitute the normal data sample and the defective data sample into the characteristic factors, respectively. . And the controller 500 ranks each characteristic factor as shown in Table 2 below using a T-Test, which is an index for separating the two groups, and ranks each of the characteristic factors in the upper certain number range (for example, the upper 2 Dog) can select (eg, Skewness, THD) the higher-order characteristic factors included in

Table 2 is a ranking of whether the values calculated through Table 1 are the best criteria for classifying defects. The method used as a measure that can classify defects well is the conventional T-Test technique.

[Table 2]

When the upper characteristic factors (eg, the upper two) are selected, the controller 500 may classify the measured vibration signal into a normal vibration signal or a defective vibration signal according to whether the characteristic factors are satisfied with respect to the reference range. In other words, the controller 500 may determine the normal vibration signal or the defective vibration signal by comparing the distribution between the selected upper characteristic factors.

For example, as shown in FIG. 4 , the controller 500 selects the distribution of the upper characteristic factors as a normal area A1 without defects and a defective area A2 where defects occur, and selects the normal area A1. A distribution diagram ( FIG. 4 ) in which an imaginary dividing line L is created in the region between the and the defective region A2 is calculated. At this time, the controller 500 determines the characteristic factor distributed in the normal area A1 as a normal vibration signal based on the dividing line L of the calculated distribution map, and converts the characteristic factor distributed in the defective area A2 to the defective vibration signal. can be judged as

When the normal vibration signal or the defective vibration signal is determined, the controller 500 may control the speed of the test drum 100 and the movement of the carrier 300 according to the normal vibration signal or the defective vibration signal. For example, if the characteristic factor is determined as a defect vibration signal, the controller 500 stops the speed of the test drum 100 so that the test is stopped before an accident due to the defect occurs, and the carrier 300 moves the tire (T). ) can be separated from the test drum 100 .

The controller 500 may include a DAQ, a PLC, and a Control PC.

As the Control PC, a high-performance PC may be used. One CPU core measures the vibration signal, and the other CPU core can detect real-time faults by applying the measured vibration signal to the algorithm, and the other CPU core can control the PLC signal.

For example, if you start the tester in PLC, you can measure the vibration signal in the instrument at the same time. At this time, the measured signal can detect the occurrence of a fault in the Control PC in real time, and if no fault occurs, the test can be continued. If an initial fault occurs, the Control PC can apply a Stop command to the PLC. , it is possible to stop the test drum 100 and the carrier 300 (see FIG. 2 ).

Hereinafter, the operation of the tire testing machine according to the embodiment of the present invention having the above configuration will be described.

As shown in FIG. 3 , through the ECE-R30 High Speed test, the time when the accident occurred on the raw data can be known as the point where the shock signal appeared, but it is not known when the initial defect occurred and the defect progressed. Therefore, in order to check when the initial defect occurred and the defect progressed, the characteristic factor is used.

The ECE-R30 High Speed test is a test in which the speed is increased every 10 minutes, and it is known that an initial defect occurs a few seconds before the defect occurs, and an accident occurs as the size increases momentarily.

After dividing the normal data sample immediately after the tire speed increase and the defect data sample before the accident into two groups, the two groups are substituted into the characteristic factors, respectively, and the T-Test, an index that separates the two groups well ) to rank each characteristic factor (see Table 2).

And, as shown in FIG. 4, the top two characteristic factors are selected and their respective values are expressed as a distribution. For example, a virtual dividing line (L) that can best classify two groups is created, and when a new tire is tested, the presence or absence of a defect is determined based on the virtual dividing line (L) based on the input vibration signal.

As described above, according to the present invention, it is possible to know the part where the durability of the tire is weak, so that the durability of the tire can be effectively improved by supplementing the part, and when a tire accident occurs, a safety accident in which debris is blown to the surrounding workers It can be prevented in advance, the time of occurrence of defects can be consistently maintained by determining the time of the initial accident, and the drum and rim of the testing machine can be rotated to prevent damage to the testing machine, saving a lot of cost in terms of maintenance and management of the testing machine. It has excellent advantages such as saving.

Although the embodiments of the present invention have been described with reference to the accompanying drawings, those of ordinary skill in the art to which the present invention pertains can be implemented in other specific forms without changing the technical spirit or essential features. You will be able to understand. For example, those skilled in the art may change the material, size, etc. of each component according to the field of application, or combine or substitute the embodiments in a form not clearly disclosed in the embodiment of the present invention, but this is also the present invention is not outside the scope of Therefore, the embodiments described above should not be understood as illustrative and limiting in all respects, and it should be said that these modified embodiments are included in the technical spirit described in the claims of the present invention.

100: test drum 200: spindle unit
300: carrier 400: instrument
500: controller

Claims (5)

a test drum rotatable against the tire;
a spindle unit coupled to the wheel of the tire;
a carrier for moving the spindle unit;
a measuring instrument that measures a vibration signal generated during a tire driving test; and
Among the measured vibration signals measured by the instrument, the test drum is classified into a normal vibration signal and a defective vibration signal according to the vibration signal state when the tire is in a normal or defective state, and through the normal vibration signal and the defective vibration signal, the test drum Containing a controller for controlling the speed and movement of the carrier,
tire tester. The method of claim 1,
the controller is
ECE-R30 high speed test to measure vibration signals until an accident,
tire tester. The method of claim 1,
the controller is
After dividing the normal data sample immediately after the tire speed increase and the defective data sample before the accident into two groups, the normal data sample and the defective data sample are respectively substituted into the characteristic factors, and the two groups are separated After ranking each characteristic factor by using the T-Test, which is an index, the characteristic factor included in the upper certain number range is selected, and then the characteristic factor of the normal data sample and the characteristic of the defective data sample to compare the distribution between factors,
tire tester. The method of claim 1,
the controller is
After selecting the distribution of each characteristic factor as a normal region without defects and a defective region in which defects occur, and calculating a distribution map in which an imaginary dividing line is made in the region between the selected normal region and the defective region, the newly measured vibration When the characteristic factor of the signal is distributed in the normal region based on the dividing line of the calculated distribution, it is determined as the normal vibration signal, and when distributed in the defective region, it is determined as the defective vibration signal,
tire tester. The method of claim 3,
the controller is
Through the ECE-R30 High Speed test, which can test when an accident occurred due to an initial defect, a normal data sample immediately after the speed of the tire is increased and a defect data sample before the accident occurs,
tire tester.

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