KR102503857B1 - Defect diagnosis device and wheel bearing for vehicle provided therewith - Google Patents

Abstract

According to one embodiment of the present invention, there is provided a fault diagnosis device mounted on a wheel bearing to diagnose whether the wheel bearing is faulty or abnormally operated. A failure diagnosis apparatus according to an embodiment of the present invention may include a detection unit for detecting an operating state of a wheel bearing and a diagnosis unit for diagnosing a failure or abnormal operation of the wheel bearing using signal information detected by the detection unit. According to one embodiment of the present invention, the detection unit may include an acceleration sensor that collects acceleration information of the wheel bearing, and the diagnosis unit may be configured to diagnose abnormal operation of the wheel bearing by frequency-analyzing the acceleration signal information collected from the acceleration sensor. there is. According to an embodiment of the present invention, the diagnosis of whether the wheel bearing is faulty or abnormal may be configured to be performed based on acceleration signal information collected from an acceleration sensor and speed information calculated from the acceleration signal information.

Description

Fault diagnosis device and wheel bearing for a vehicle having such a fault diagnosis device {Defect diagnosis device and wheel bearing for vehicle provided therewith}

The present invention relates to a failure diagnosis device for diagnosing failure or abnormal operation of a wheel bearing, and a wheel bearing for a vehicle having such a failure diagnosis device, and more particularly, to a reliable method for determining failure or abnormal operation of a wheel bearing using an acceleration sensor. It relates to a fault diagnosis device configured to be able to accurately diagnose and a wheel bearing for a vehicle having the same.

[This invention is the result of a study conducted by the Ministry of SMEs and Startups and the Korea Institute for Advancement of Technology for regionally specialized industry development projects (R&D, P0000519)]

A wheel bearing is a device that rotatably mounts and supports the wheels of a vehicle to a vehicle body. It is configured to mount and support a wheel mounted on a rotating element (wheel hub) in a rotatable state on a vehicle body.

However, since these wheel bearings are subjected to large loads and moments in the radial and axial directions while the vehicle is running, damage such as flaking may occur to the outer or inner rings supporting the rolling elements, which may cause damage. , Such damage can cause noise, vibration, heat, etc., or in severe cases, the wheel bearing may be seized or separated from the drive shaft, leading to a major accident.

In the past, chassis components such as wheel bearings were not equipped with a diagnostic function to monitor the operating state of the components, so drivers had to detect noise or vibration on their own to intuitively determine abnormalities in chassis components such as wheel bearings.

However, this intuitive judgment has a problem in that it is difficult to perform an accurate diagnosis of abnormal operation because the judgment result varies greatly depending on the driver's skill level and the reliability of the judgment result cannot be guaranteed.

In order to solve this problem, recently, a technique for monitoring operating states of chassis parts including wheel bearings by attaching sensors to wheel bearings has been proposed. For example, referring to Patent Document 1, a technology for diagnosing a failure of a wheel bearing or the like by mounting a rotation speed sensor and an acceleration sensor to a wheel bearing or a vehicle body is disclosed.

Specifically, Patent Document 1 collects the acceleration signal (vibration signal) and speed signal of the vehicle in motion using an acceleration sensor attached to the knuckle of the vehicle and a rotational speed sensor attached to the wheel bearing, and based on this, the failure of the wheel bearing A technique for diagnosing is disclosed.

However, since these conventional fault diagnosis techniques require both acceleration information (vibration information) from the acceleration sensor and speed information from the rotation speed sensor for fault diagnosis, the rotation speed sensor and All acceleration sensors must be mounted, and complex wiring is required inside the vehicle to interlock signals from these sensors, resulting in a complicated hardware and software structure inside the vehicle body and an increase in manufacturing cost.

Korean Patent Publication No. 10-2011-0131411 (Publication date: 2011.12.7.)

SUMMARY OF THE INVENTION The present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a fault diagnosis device having a simpler structure and capable of reliable fault diagnosis, and a wheel bearing for a vehicle having the same.

Representative configurations of the present invention for achieving the above object are as follows.

According to one embodiment of the present invention, there is provided a fault diagnosis device mounted on a wheel bearing to diagnose whether the wheel bearing is faulty or abnormally operated. A failure diagnosis apparatus according to an embodiment of the present invention may include a detection unit for detecting an operating state of a wheel bearing and a diagnosis unit for diagnosing a failure or abnormal operation of the wheel bearing using signal information detected by the detection unit. According to one embodiment of the present invention, the detection unit may include an acceleration sensor that collects acceleration information of the wheel bearing, and the diagnosis unit may be configured to diagnose abnormal operation of the wheel bearing by frequency-analyzing the acceleration signal information collected from the acceleration sensor. there is. According to an embodiment of the present invention, the diagnosis of whether the wheel bearing is faulty or abnormal may be configured to be performed based on acceleration signal information collected from an acceleration sensor and speed information calculated from the acceleration signal information.

According to one embodiment of the present invention, the speed information used to diagnose whether the wheel bearing is faulty or abnormal is processed by root mean square (RMS) of the acceleration signal information collected from the acceleration sensor, and then the RMS peak It can be calculated by considering the frequency with the value as the rotational frequency of the wheel bearing.

According to one embodiment of the present invention, the diagnosis unit may include a control unit for diagnosing whether the wheel bearing is faulty or abnormally operated based on a signal from the detection unit, and the control unit includes a filtering unit and a filtering unit for filtering the signal transmitted from the detection unit. It may include a signal analysis unit receiving the filtered signal from the unit and performing frequency analysis, and a failure diagnosis unit diagnosing a failure or abnormal operation of the wheel bearing based on the analysis result of the signal analysis unit.

According to one embodiment of the present invention, the filtering unit may be configured to filter a signal transmitted from the acceleration sensor through a band pass filter.

According to one embodiment of the present invention, the acceleration sensor may be configured to be used by being mounted on an outer ring of a wheel bearing.

According to one embodiment of the present invention, the detection unit may further include a temperature sensor for measuring the temperature inside the wheel bearing.

According to one embodiment of the present invention, the diagnostic unit may be configured to diagnose whether the wheel bearing is malfunctioning or abnormally operating by using both acceleration signal information collected from the acceleration sensor and temperature information collected from the temperature sensor.

According to one embodiment of the present invention, a wheel bearing for a vehicle supporting a wheel of a vehicle by being rotatably mounted on a vehicle body may be provided. According to an embodiment of the present invention, a vehicle wheel bearing according to an embodiment of the present invention may be configured to include the above-described fault diagnosis device.

In addition to this, other additional components may be further included in the fault diagnosis device and the wheel bearing for a vehicle having the same according to the present invention within a range that does not impair the technical spirit of the present invention.

A fault diagnosis apparatus according to an embodiment of the present invention and a wheel bearing for a vehicle having the same can diagnose a fault or abnormal operation of the wheel bearing using only acceleration signal information (vibration signal information) from an acceleration sensor mounted on an outer ring of the wheel bearing. Since it is configured so that the wheel bearing and the inside of the vehicle do not require complicated wiring work for interlocking the rotational speed sensor and the acceleration sensor inside the vehicle, the structure of the wheel bearing and the vehicle can be simplified and the manufacturing cost can be reduced. do.

In addition, since the wheel bearing for a vehicle according to an embodiment of the present invention does not need to interlock the rotational speed sensor and the acceleration sensor for fault diagnosis, the acceleration sensor can be formed at an arbitrary position regardless of the location of the rotational speed sensor. As a result, the degree of freedom in the design of the wheel bearing can be greatly increased.

1 exemplarily illustrates the structure of a wheel bearing for a vehicle according to an embodiment of the present invention.
2 illustratively shows a cross-sectional structure of a wheel bearing for a vehicle according to an embodiment of the present invention.
3 illustratively illustrates a structure of a detection unit of a failure diagnosis apparatus applicable to a wheel bearing for a vehicle according to an embodiment of the present invention.
4 is a block diagram conceptually showing the configuration of a failure diagnosis apparatus that can be applied to a wheel bearing for a vehicle according to an embodiment of the present invention.
5 exemplarily shows frequency spectrums of normal frequencies and defect frequencies in a rotational frequency band.

Hereinafter, with reference to the accompanying drawings, a preferred embodiment of the present invention will be described in detail so that those skilled in the art can easily practice it.

In order to clearly describe the present invention, detailed descriptions of parts not related to the present invention will be omitted, and the same reference numerals will be given to the same components throughout the specification. In addition, since the shape and size of each component shown in the drawings are arbitrarily shown for convenience of description, the present invention is not necessarily limited to the illustrated shape and size. That is, specific shapes, structures, and characteristics described in the specification may be modified and implemented from one embodiment to another without departing from the spirit and scope of the present invention, and the location or arrangement of individual components may also be implemented without departing from the spirit and scope of the present invention. and can be changed without departing from its scope. Therefore, the detailed description to be described later is not performed in a limiting sense, and the scope of the present invention should be taken as encompassing the scope claimed by the claims and all scopes equivalent thereto.

Preferred Embodiments of the Invention

1 to 5, a wheel bearing 10 for a vehicle according to an embodiment of the present invention is shown by way of example. As shown in FIGS. 1 and 2 , the vehicle wheel bearing 10 according to an embodiment of the present invention may be formed similarly to a conventional wheel bearing device. For example, the vehicle wheel bearing 10 according to an embodiment of the present invention includes a wheel hub 20 (rotating element), an inner ring 30, an outer ring 40 (non-rotating element), a rolling element 50, and the like. It can be.

According to one embodiment of the present invention, the wheel hub 20 may be formed in a substantially cylindrical structure extending along the axial direction, and a hub flange may be provided near the wheel-side end of the wheel hub 20. . The hub flange is formed in a shape extending radially outward along the circumferential direction of the wheel hub 20 and can be used to mount a wheel to the wheel hub 20 using hub bolts or the like. Meanwhile, a stepped portion may be formed at an end of the vehicle body of the wheel hub 20 to mount the inner ring 30, and a raceway surface (inner raceway surface) is formed on a part of the outer circumferential surface of the wheel hub 20 to form a rolling element ( 50) may be configured to support it from the inside. However, in the case of the embodiment shown in the drawings, one side of the raceway for supporting rolling elements is directly formed on a part of the outer circumferential surface of the wheel hub, but unlike this, two inner rings are mounted on the wheel hub so that the transmission is transmitted through the two inner rings. It may be configured so that the raceway surface (inner raceway surface) of the body is formed.

The inner ring 30 may be configured to be mounted by being press-fitted to one side of the wheel hub 20 . For example, the inner ring 30 plastically deforms the end of the wheel hub 20 as shown in FIG. It may be configured to be seated and maintained on the wheel hub 20 by fastening a nut or the like to an end portion of the vehicle body. In addition, the outer circumferential surface of the inner ring 30 may be provided with a raceway surface (inner raceway surface) with which the rolling element 50 contacts to support the rolling element from the inside.

The outer ring 40 may be configured to have a mounting flange on an outer circumferential surface for mounting the wheel bearing 10 on the vehicle body, and to have a raceway surface (outer raceway surface) on an inner circumferential surface on which the rolling element 50 contacts. The raceway surface (outer raceway surface) formed on the inner circumferential surface of the outer ring 40 cooperates with the raceway surface (inner raceway surface) formed on the wheel hub 20 and/or the inner ring 30 to form a rolling element (rolling element) between the raceway surfaces. 50) may be configured to receive and support it.

The rolling element 50 is disposed between the raceway surface (inner raceway surface) formed on the wheel hub 20 and/or the inner ring 30 and the raceway surface (outer raceway surface) formed on the outer ring 40, so that the wheel is mounted. It may perform a function of rotatably supporting the wheel hub 20 with respect to the outer wheel 40 fixed to the vehicle body.

Meanwhile, the vehicle wheel bearing 10 according to an embodiment of the present invention may further include a failure diagnosis device 60 capable of diagnosing failure or abnormal operation of the wheel bearing. As shown in FIG. 4, the fault diagnosis apparatus 60 of the wheel bearing 10 for a vehicle according to an embodiment of the present invention is based on the detection unit 70 for detecting the operating state of the wheel bearing and the signal information detected by the detection unit. It may include a diagnosis unit 80 for diagnosing the operating state of the wheel bearing.

According to one embodiment of the present invention, the detection unit 70 may be provided with an acceleration sensor 72 for detecting a vibration state of the wheel bearing. For example, the acceleration sensor 72 may be mounted on the outer race 40 of the wheel bearing 10 to detect the vibration state of the wheel bearing 10 . The acceleration sensor 72 includes a 1-axis acceleration sensor capable of measuring acceleration in any one direction among x, y, and z-axis directions perpendicular to each other, a 2-axis acceleration sensor capable of measuring acceleration in two directions, and acceleration measurement in all three directions. Any of the possible 3-axis accelerometers can be configured. In the vehicle wheel bearing 10 according to an embodiment of the present invention, the fault diagnosis apparatus 60 can diagnose the fault of the wheel bearing using only vibration information in a direction perpendicular to the ground (eg, z direction), but Alternatively, if the 3-axis acceleration sensor is used, additional diagnosis such as diagnosing not only wheel bearing failure but also drive shaft (CVJ) or wheel alignment abnormality, brake judder or wheel balance abnormality can be performed, which can be more advantageous. .

According to one embodiment of the present invention, a detection device such as a temperature sensor 74 may be additionally provided in the detection unit 70 of the failure diagnosis device 60 . Since the temperature sensor 74 can diagnose the failure or abnormality of the wheel bearing through the temperature change inside the wheel bearing, the inflow of foreign substances or leakage of lubricating oil (grease) that is difficult to grasp through the detection information from the acceleration sensor It is possible to perform fault diagnosis of the wheel bearing by the etc., so that the diagnosis function of the fault diagnosis device can be further improved.

According to an embodiment of the present invention, the diagnosis unit 80 of the failure diagnosis device 60 may perform a function of diagnosing an operating state of a wheel bearing or the like by receiving signal information obtained through the detection unit 70. . For example, the diagnosis unit 80 uses the first input/output unit 82 that receives the detection signal from the detection unit 70 and the signal information (eg, acceleration signal information) transmitted from the first input/output unit 82 to detect wheel bearings. A control unit 84 for diagnosing the operating state of the back, a memory unit 86 for storing reference data or diagnostic/analysis results, etc., and a second input/output unit 88 for outputting diagnosis results from the control unit 84. ) and the like.

On the other hand, the control unit 84 provided in the diagnosis unit 80 is a filtering unit for filtering the input signal, a signal analysis unit for receiving and analyzing the signal filtered by the filtering unit, and a wheel based on the analysis result of the signal analysis unit. A failure diagnosis unit for diagnosing failure or abnormal operation of the bearing may be included.

According to an embodiment of the present invention, the filtering unit performs a function of removing noise by filtering the signal (eg, acceleration signal) detected by the detection unit 70, and is implemented as a band pass filter that passes only signals of a specific frequency. It can be. Next, the signal analysis unit performs a function of analyzing the signal that has passed through the filtering unit, and in the vehicle wheel bearing 10 according to an embodiment of the present invention, the acceleration signal from the acceleration sensor 72 is subjected to frequency analysis (FFT analysis) It may be configured to perform solution signal analysis. Meanwhile, the fault diagnosis unit may perform a function of diagnosing and determining whether the wheel bearing operates abnormally using the analysis result processed by the signal analysis unit.

As a result of diagnosing the operating state in the diagnosis unit 80, if it is diagnosed that there is a failure or abnormal operation in the wheel bearing, the diagnosis result is transmitted to and stored in the vehicle's ECU (Electronic Control Unit 90), etc., or a warning sound or display. It can be displayed to the user through the display unit 92 or transmitted to the driving unit 94 and used to control chassis parts of the vehicle.

Meanwhile, the vehicle wheel bearing 10 according to an embodiment of the present invention calculates the current speed of the vehicle based on the acceleration signal information detected by the acceleration sensor 72, and then calculates the detected acceleration signal information and the calculated acceleration signal information. It is characterized in that it is configured to diagnose a failure or abnormal operation of the wheel bearing using speed information.

In general, since the fault frequency varies depending on the speed of the vehicle, speed information as well as acceleration signal information (vibration information) from the acceleration sensor 72 are required to diagnose a failure or abnormal operation of a wheel bearing or the like.

For example, the defect frequencies of the inner ring, outer ring, and rolling element can be calculated through the following formula.

inner ring:

paddle:

rolling elements:

는 내륜의 결함 주파수,

는 외륜의 결함 주파수,

는 전동체의 결함 주파수,

은 축의 회전 주파수, Z는 전동체의 수, d는 전동체의 직경, D는 전동체의 피치원 직경,

는 전동체의 접촉각을 의미함][

is the defect frequency of the inner ring,

is the fault frequency of the paddle,

is the fault frequency of the rolling element,

is the rotational frequency of the shaft, Z is the number of rolling elements, d is the diameter of the rolling elements, D is the diameter of the pitch circle of the rolling elements,

means the contact angle of the rolling element]

In this regard, the fault diagnosis apparatus according to an embodiment of the present invention and the wheel bearing for a vehicle having the same are different from the conventional fault diagnosis apparatus, and speed information is obtained from acceleration signal information from an acceleration sensor without receiving speed information from a separate rotation speed sensor. After extracting the information, it can be configured to diagnose whether a malfunction or abnormal operation of the wheel bearing or the like is performed using this information.

During vehicle operation, a unique rotational frequency according to the rotation of the wheel bearing is generated. At this rotational frequency, the acceleration signal of the vehicle exhibits a large amplitude value. Therefore, the fault diagnosis apparatus according to an embodiment of the present invention calculates the root mean square (RMS) of the acceleration signal detected through the acceleration sensor 72 and then extracts the frequency having the RMS peak value from it. It may be configured to recognize the current speed by considering this as the rotational frequency.

Specifically, the fault diagnosis apparatus according to an embodiment of the present invention measures the amplitude at each time through an acceleration sensor, converts the measured amplitude at each time into a frequency (FFT conversion), extracts the unit of Hz, and extracts the RMS from the extracted data. The frequency with the peak value is searched and inverted to calculate the wheel rpm (wheel rpm = rotational frequency * 60), and the calculated rpm is inverted to calculate the vehicle speed (vehicle speed = rpm * 2π * tire travel diameter * 60/1000000) method, the speed can be calculated from the measured acceleration information.

As such, since the wheel bearing 10 for a vehicle according to an embodiment of the present invention is configured to perform a fault diagnosis of the wheel bearing by calculating the speed of the vehicle based on the acceleration signal information from the acceleration sensor 72, the rotational speed It is possible to diagnose the operating state of wheel bearings and the like without separately receiving vehicle speed information from a sensor or the like.

Therefore, unlike conventional wheel bearings having a fault diagnosis function, it is possible to simply implement a fault diagnosis device in a wheel bearing without performing complicated wiring work.

In addition, since the vehicle wheel bearing 10 according to an embodiment of the present invention can implement a failure diagnosis device only with an acceleration sensor, as shown in FIGS. 1 to 3, any The fault diagnosis device can be implemented by mounting an acceleration sensor at the position of the fault diagnosis device, which makes it easy to mount the fault diagnosis device and greatly improves the design freedom of the fault diagnosis device and a wheel bearing for a vehicle having the same.

Meanwhile, a process of diagnosing a failure in the failure diagnosis device 60 of the vehicle wheel bearing 10 according to an embodiment of the present invention may be implemented as follows.

According to an embodiment of the present invention, a method for diagnosing a fault of a fault diagnosis apparatus 60 for a vehicle wheel bearing includes the steps of collecting acceleration signal information (vibration state information) from an acceleration sensor 72 of the fault diagnosis apparatus 60. And, the step of calculating the current speed of the vehicle from the collected acceleration signal information, and the fault diagnosis step of detecting whether the wheel bearing is abnormally operated by frequency analysis (FFT analysis) of the acceleration signal information collected from the acceleration sensor 72 can include

In this case, frequency analysis in the fault diagnosis step may be performed based on acceleration signal information from the acceleration sensor 72 and speed information calculated therefrom.

In addition, according to an embodiment of the present invention, a method for calculating speed information from acceleration signal information collected by the acceleration sensor 72, as described above, converts the acceleration signal information detected by the acceleration sensor 72 to the practical area of the vehicle. (eg, 0 to 250 km/h), and then consider the frequency at which the RMS amplitude peaks as the rotation frequency to recognize the current speed.

Meanwhile, according to an embodiment of the present invention, the failure diagnosis method may further include collecting temperature information from the temperature sensor 74 before the failure diagnosis step, and in the failure diagnosis step, the temperature information from the temperature sensor 74 may be included. It can be configured to perform fault diagnosis in consideration of temperature information together.

In the above, the present invention has been described through specific details such as specific components and limited embodiments and drawings, but these are only provided to help a more general understanding of the present invention, and the present invention is not limited to the above embodiments. , Those skilled in the art in the art to which the present invention pertains will be able to make various modifications and variations from these descriptions.

Therefore, the spirit of the present invention should not be limited to the foregoing embodiments and should not be determined, and all things equivalent or equivalently modified as well as the following claims should be construed as belonging to the scope of the spirit of the present invention.

10: Wheel bearings for vehicles
20: wheel hub
30: outer ring
40: inner ring
50: rolling element
60: fault diagnosis device
70: detection unit
72: acceleration sensor
74: temperature sensor
80: diagnosis unit
82: first input/output unit
84: control unit
86: memory unit
88: second input/output unit
90: vehicle's ECU
92: display unit
94: driving unit

Claims (8)

A fault diagnosis device (60) mounted on a wheel bearing to diagnose a fault or abnormal operation of the wheel bearing,
A detection unit 70 for detecting the operating state of the wheel bearing;
A diagnosis unit 80 for diagnosing whether the wheel bearing is faulty or abnormally operated using the signal information detected by the detection unit 70,
The detection unit 70 includes an acceleration sensor 72 that collects acceleration information of the wheel bearing,
The diagnosis unit 80 is configured to perform frequency analysis on the acceleration signal information collected from the acceleration sensor 72 to diagnose a failure or abnormal operation of the wheel bearing,
Diagnosis of failure or abnormal operation of the wheel bearing is performed based on acceleration signal information collected from the acceleration sensor 72 and speed information calculated from the acceleration signal information,
The speed information used to diagnose the failure or abnormal operation of the wheel bearing is root mean square (RMS) processing of the acceleration signal information collected from the acceleration sensor 72, and then the frequency having the RMS peak value is converted into a wheel I consider it to be the rotational frequency of the bearing and am calculated,
fault diagnosis device. delete According to claim 1,
The diagnosis unit 80 includes a control unit 84 for diagnosing whether the wheel bearing is faulty or abnormally operated based on a signal from the detection unit 70,
The control unit 84 includes a filtering unit for filtering the signal transmitted from the detection unit 70, a signal analysis unit for receiving the signal filtered by the filtering unit and performing frequency analysis, and based on the analysis result of the signal analysis unit Including a fault diagnosis unit for diagnosing a fault or abnormal operation of the wheel bearing,
fault diagnosis device. According to claim 3,
The filtering unit filters the signal transmitted from the acceleration sensor through a band pass filter.
fault diagnosis device. According to claim 4,
The acceleration sensor 72 is used by being mounted on the outer ring of the wheel bearing,
fault diagnosis device. According to claim 4,
The detection unit 70 is further provided with a temperature sensor 74 for measuring the temperature inside the wheel bearing,
fault diagnosis device. According to claim 6,
The diagnostic unit 80 is configured to diagnose whether the wheel bearing is faulty or abnormally operated by using the acceleration signal information collected from the acceleration sensor 72 and the temperature information collected from the temperature sensor 74 together.
fault diagnosis device. A wheel bearing (10) for a vehicle that rotatably mounts and supports a vehicle wheel on a vehicle body,
Equipped with the failure diagnosis device according to any one of claims 1 and 3 to 7,
Wheel bearings for vehicles.

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