Vehicle brake pad wear detection system and method

Abstract

The present invention relates to a brake pad wear detection system for a vehicle and a method thereof, which monitors the wear amount of a brake pad by installing a wear sensor at a brake caliper and issues a warning for a replacement timing, thereby preventing traffic accidents, including: a wear sensor provided at one end of a caliper of a disc brake to measure the wear amount of a brake pad; and a control unit monitoring the wear amount of the brake pad input from the wear sensor, and outputting a brake pad replacement timing warning signal to a display unit and an alarm unit when the brake pad wear value input from the wear sensor exceeds a reference value. It can further include a wireless communication module connected to the control unit to transmit a replacement timing warning signal according to the wear value and the remaining thickness of the brake pad to a mobile terminal; and a wireless communication module connected to the control unit to transmit a replacement timing warning signal according to the wear value and the remaining thickness of the brake pad to a specific terminal or a vehicle management server connected through a wireless communication network.

Description

Technical Field

[0001] This invention relates to a wear detection system and method for vehicle brake pads. A wear sensor is installed at the caliper of a disc brake to monitor the wear of the brake pads and issue an alarm when it is time to replace them, thereby preventing traffic accidents. Background Technology

[0002] Normally, vehicle braking is achieved by reducing the rotational force of the wheels through the friction between the brake discs and brake pads. That is, when braking, the brake pedal is pressed, and the hydraulic pressure transmitted through the brake lines to the disc brakes causes the brake pads to press against the brake discs, thus braking the vehicle. Furthermore, as braking occurs, the brake pads wear proportionally to the braking force.

[0003] As a result, when brake pads wear down due to repeated braking of a vehicle, problems such as longer braking distance and abnormal braking sensation may occur. In the case of heavy-duty commercial vehicles, the increased braking distance can lead to an increased risk of accidents. Therefore, various technologies are being developed to measure the wear of brake pads.

[0004] However, as an example of existing brake pad wear detection devices, when the brake pads reach their wear limit, the end of the sensor is worn off and the alarm circuit is activated. If the end of the sensor contacts the brake disc, the warning light will illuminate. However, this method only allows the driver to detect the wear when the brake pads reach their wear limit. In addition, a shaft connected to a slider of a linear variable resistor is positioned at the brake pad. The shaft and slider move according to the degree of brake pad wear, and the wear is detected by the changing resistance value of the linear variable resistor. Although the structure is simple, it suffers from various problems such as decreased sensitivity, drastic resistance changes, and low reliability.

[0005] <Prior art documents> (Patent Document 1) Korean Patent Publication No. 10-0123822 (Invention Title: Braking Device with Friction Plate Wear Detection Sensor, 1997.12.08. Patent Announcement) (Patent Document 2) Korean Utility Model Publication No. 20-1998-0040781 (Utility Model Title: Brake Pad Replacement Timing Alarm Device for Automobile Disc Brakes, 1998.09.15. Utility Model Publication) (Patent Document 3) Korean Patent Publication No. 10-2015-0137718 (Invention Title: Electronic Caliper Brake, Patent Publication Date: December 9, 2015) Summary of the Invention Technical problems to be solved The technical problem to be solved by the present invention is to provide a brake pad wear detection system for vehicles, which monitors the wear of brake pads and issues an alarm when it is time to replace them by installing a wear sensor at the brake caliper, thereby preventing traffic accidents.

[0006] Technical solution The vehicle brake pad wear detection system of the present invention includes: a pair of backplates disposed opposite to each other inside the caliper; brake pads fixed to the front of the backplates; a brake disc disposed between the brake pads; a wear sensor disposed at one end of the caliper to measure the wear amount of the brake pads; and a control unit that monitors the wear amount of the brake pads input from the wear sensor, and outputs an alarm signal indicating the replacement timing based on the remaining thickness of the brake pads to a display unit and an alarm unit when the brake pad wear value input from the wear sensor exceeds a reference value.

[0007] It also includes a wireless communication module, which is connected to the control unit and transmits an alarm signal to the mobile terminal based on the brake pad wear value and remaining thickness to indicate when to replace the brake pads.

[0008] It also includes a wireless communication module, which is connected to the control unit and transmits an alarm signal based on the brake pad wear value and remaining thickness to a specific terminal or vehicle management server connected via a wireless communication network.

[0009] The wear sensor includes: an automatic clearance adjustment device configured at the caliper; an adjustment gear configured at the automatic clearance adjustment device; a connecting gear meshing with the adjustment gear; a sensor shaft extending from the connecting gear and rotating in linkage; a reducer whose shaft is connected to the end of the sensor shaft; a permanent magnet fixed to the output shaft of the reducer; and a Hall sensor positioned opposite the permanent magnet to detect the rotating magnetic field of the permanent magnet. The Hall sensor measures the change in magnetic flux generated when the permanent magnet rotates, converts it into voltage, and outputs it. Thus, the wear value of the brake pads that have become thinner due to braking friction can be obtained.

[0010] The method for detecting brake pad wear for vehicles according to the present invention includes the following steps: a) measuring the wear value of the brake pads using a wear sensor installed at the caliper of a disc brake; b) inputting the brake pad wear value measured in real time or not in real time to a control unit and monitoring it; c) the brake pads wear due to braking; d) the control unit comparing the brake pad wear value input from the wear sensor with a reference value; e) when the brake pad wear value input from the wear sensor exceeds the reference value, outputting a replacement timing alarm signal based on the remaining thickness of the thinned brake pads; and f) issuing a brake pad replacement timing alarm through a display unit and an alarm unit based on the alarm signal.

[0011] It also includes: after issuing a brake pad replacement timing alarm through the display unit and the alarm unit according to the alarm signal in f), transmitting the replacement timing alarm signal based on (considering) the wear value and remaining thickness of the brake pad to the mobile terminal through the wireless communication module of the control unit.

[0012] It also includes: f) after the alarm is triggered by the display unit and the alarm unit according to the alarm signal, the alarm signal indicating the replacement timing based on the brake pad wear value and remaining thickness is transmitted to a specific terminal or vehicle management server stored in the control unit via the wireless communication module and wireless communication network of the control unit.

[0013] Beneficial effects This invention uses a wear sensor installed at the caliper of a disc brake to detect the wear of the brake pads and issues an alarm when it is time to replace them. This allows for timely replacement of brake pads, which is not only economical but also helps prevent vehicle accidents and protects valuable lives and property.

[0014] This invention utilizes a permanent magnet and a Hall sensor in an automatic gap adjustment device that maintains a certain gap between the brake pads and the brake disc to detect the wear of brake pads 4 and 5 in a non-contact manner and issue an alarm when it is time to replace them. As a result, compared with existing contact-type pad wear devices, it has the advantages of excellent accuracy in measuring brake pad wear (wear value), no temperature deviation, excellent durability, unaffected by vehicle vibration and impact, and significantly improved reliability. It is a very useful invention. Attached Figure Description

[0015] Figure 1 : A planar cross-sectional diagram shown as an embodiment of the present invention.

[0016] Figure 2 : A side cross-sectional view shown as an embodiment of the present invention.

[0017] Figure 3 : A circuit block diagram shown as an embodiment of the present invention.

[0018] Figure 4 : A circuit block diagram shown as another embodiment of the present invention.

[0019] Figure 5 The following is a system flowchart shown as an embodiment of the present invention.

[0020] Figure 6 : A system flowchart shown as another embodiment of the present invention.

[0021] Explanation of reference numerals in the attached figures 1—Caliper 2, 3—Backplate 4, 5—Brake pads 6—Brake disc 7-piece automatic gap adjustment device 8—Adjusting Gear 9—Wear Sensor 10—Control Unit 11—Connecting Gear 12-Piston 13—Sensor Shaft 14—Reducer 15—Permanent magnet 16—Hall IC Sensor 20—Settings Department 21—Display Section 22—Alarm Department 23—Wireless Communication Module 24—Mobile Terminal 25—Wireless Communication Network 26—Specific Terminals 27—Management Server Detailed Implementation Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In describing the embodiments of the present invention, the same constituent elements in the drawings will be referred to using the same reference numerals as much as possible, and specific descriptions of related well-known structures or functions will be omitted to avoid obscuring the essence of the present invention. Furthermore, the items illustrated in the drawings are for the purpose of illustrating the embodiments of the present invention and may differ from the actual implementation.

[0022] Figure 1 and Figure 2 This is a structural diagram of a vehicle brake pad wear detection system as an embodiment of the present invention. Inside the caliper 1 of a disc brake, a pair of back plates 2 and 3 are arranged opposite each other. Brake pads 4 and 5 are fixed to the front of the back plates 2 and 3, and a brake disc 6 is disposed between the brake pads 4 and 5. The system includes: a wear sensor 9, which is disposed at the adjusting gear 8 of the brake pad automatic clearance adjustment device 7 located at the caliper 1, and measures the wear amount of the brake pads 4 and 5; and a control unit 10, which monitors the wear amount of the brake pads 4 and 5 input from the wear sensor 9, and outputs a brake pad wear alarm signal to the display unit and the alarm unit when the wear value of the brake pads 4 and 5 input from the wear sensor 9 exceeds a reference value.

[0023] Normally, the brake disc and brake pads 4 and 5 maintain a certain distance. During braking, when the brake pads 4 and 5 wear down due to friction and exceed a certain level, the automatic gap adjustment device 7 operates to maintain the gap between the brake disc and brake pads 4 and 5. This is achieved by rotating the adjusting gear 8 to bring the front and rear back plates 2 and 3 closer together, while simultaneously maintaining a constant gap between the brake disc 6 and brake pads 4 and 5, thus preventing a reduction (or loss) of braking force in the disc brake. When frequent braking causes the brake pads 4 and 5 to wear down to a certain thickness, the automatic gap adjustment device 7 operates again through the above process. The worn brake pads 4 and 5 advance at a predetermined distance, while maintaining a constant gap with the brake disc 6, thereby preventing a reduction in braking force.

[0024] Although the brake pads 4 and 5 maintain a certain gap with the brake disc 6 while moving through the automatic gap adjustment device 7, if the brake pads are worn excessively due to frequent use, the braking force will be lost, which may lead to a major accident. Therefore, in this invention, a wear sensor 9 is installed in the automatic gap adjustment device 7 to detect the wear of the brake pads 4 and 5. When the brake pads 4 and 5 are worn excessively, the system detects the situation and issues an alarm to indicate when to replace them.

[0025] The automatic gap adjustment device 7 causes the adjusting gear 8 to rotate in one direction via a drive component (not shown in the figure). The connecting gear 11, which meshes with the adjusting gear 8, rotates, and the piston 12, which meshes with the connecting gear 11 via a ball screw structure, moves forward, pushing the back plates 2 and 3. This keeps the gap between the brake pads 4 and 5 and the brake disc 6 constant. The end of the sensor shaft 13, which is extended and formed or combined with the connecting gear 11 on one side and rotates in linkage, is connected to a reducer 14 composed of multiple gears. A disc-shaped multipole permanent magnet 15 is provided at the output shaft of the reducer 14 and rotates at a reduced speed. A Hall sensor 16 is fixedly arranged close to and opposite the permanent magnet 15. The Hall sensor 16 measures the rotating magnetic field (magnetic flux change) of the permanent magnet 15 and then converts it into a voltage output. Thus, a wear sensor 9 is formed that can obtain the wear value of the brake pads 4 and 5, which have become thinner due to braking friction.

[0026] Even if the connecting gear 11 rotates multiple times, the permanent magnet 15 rotates at an angle of less than 360° through the reducer 14, so the Hall sensor 16 can accurately measure the rotating magnetic field (rotational displacement) of the permanent magnet 15.

[0027] When the adjusting gear 8 and the connecting gear 11 rotate, the piston 12, which is engaged with the connecting gear 11 through the ball screw structure, moves forward in a straight line and pushes the back plates 2 and 3, thereby maintaining a constant gap between the brake pads and the brake disc.

[0028] To maintain a constant gap between the brake pads and the brake disc, when the adjusting gear 8 rotates, the Hall sensor 16 detects the rotational magnetic flux of the permanent magnet located at the output shaft of the reducer 14 and rotating at a reduced speed. The wear sensor 9 is a rotational detection type that detects the wear of brake pads 4 and 5. It is also a non-contact type. Compared with existing contact wear sensors, it not only has excellent measurement accuracy, no temperature deviation, and excellent durability, but is also unaffected by vehicle vibration and impact. It can measure the wear of brake pads 4 and 5 and has high reliability.

[0029] Figure 3 To illustrate the circuit block diagram of the brake pad wear detection system of the present invention, the input side of the control unit 10 is connected to: a wear sensor 5, which measures and inputs the wear value when the thickness of the brake pads 4 and 5 decreases due to friction; and a setting unit 20, which sets a wear reference value and monitoring conditions or states, etc., as a reference value when determining the amount or degree of wear of the brake pads 4 and 5.

[0030] The output side of the control unit 7 includes: a display unit 21, which is located on the dashboard or instrument panel in the driver's seat, and displays the measured values ​​of the real-time or non-real-time wear of each brake pad using indicator lights, seven-segment displays, LEDs, LCDs, etc.; an alarm unit 22, which issues an alarm based on the replacement timing of the brake pads due to wear and thinning, or considering the replacement timing of the brake pads due to the remaining thickness, using a buzzer, siren, etc.; and a wireless communication module 23, which wirelessly transmits the alarm signal based on the wear value and remaining thickness of the brake pads 4 and 5 to the mobile terminal 23 carried by the driver.

[0031] The control unit 10 monitors the wear values ​​(amount of wear) of brake pads 4 and 5 input from the wear sensor 9, and uses control logic to display the wear values ​​of brake pads 4 and 5 input from the wear sensor 9 on the display unit 21, and issues an alarm through the alarm unit 22, so that the driver can immediately recognize the wear and replace the brake pads 4 and 5 in time to prevent vehicle accidents.

[0032] The wear sensor 9 of the present invention is installed at the automatic gap adjustment device 7 to measure the wear value of brake pads 4 and 5 in a rotary, non-contact manner, thereby preventing wear or deformation of the wear sensor 9, vehicle vibration, noise, etc.

[0033] The wireless communication module 23 can be RF WiFi, Bluetooth, USB, beacon, RF WiFi (Radio Frequency Wireless Fidelity) with a communication range of several kilometers, wireless data logger, etc.

[0034] The beacon is a new generation of smartphone short-range communication technology using Bluetooth Low Energy. It can locate mobile terminals 14 within a radius of 50 to 70 meters (call connection) and transmit alarm signals that take into account the wear value and remaining thickness of brake pads 4 and 5 to indicate when to replace them.

[0035] The alarm unit 22 can use various methods to issue an alarm, including not only auditory methods but also tactile methods that stimulate the driver's skin.

[0036] When the driver's tractor is connected to and towed by a trailer at the rear, the wireless communication module 23 can be applied to the brakes of the trailer because a considerable distance is maintained between the tractor and the trailer. The system will transmit the replacement timing alarm signal based on the wear value of the brake pads 4 and 5 measured by the wear sensor 9 and the remaining thickness of the brake pads 4 and 5 by the control unit 10, or the replacement timing alarm signal considering the remaining thickness of the brake pads 4 and 5, to the driver's mobile terminal 24 via the wireless communication module 23. Therefore, the driver or maintenance personnel can recognize and replace the brake pads 4 and 5 in a timely manner to prevent major accidents.

[0037] Figure 4 This is a circuit block diagram of another embodiment of the brake pad wear detection system of the present invention. It shows that the wear status of brake pads 4 and 5 can be transmitted to a specific terminal 26 or vehicle management server 27 of the manager (or specific personnel) via the wireless communication module 23 and the wireless communication network 15. The replacement timing alarm signal based on the wear value signal and remaining thickness of each brake pad 4 and 5 can be transmitted to the specific terminal 26 and / or vehicle management server 17 via the wireless communication module 13 of the control unit 7 and the commercial or non-commercial wireless communication network 15. This enables the database to be used for the wear status of brake pads 4 and 5 of vehicles belonging to freight companies, bus companies, passenger transport companies, taxi companies, etc., and can be actively used for subsequent replacement and maintenance of brake pads 4 and 5. The vehicles belonging to the above companies are assigned and given identification numbers or codes respectively.

[0038] The wireless communication network 15 can be used for commercial or business purposes.

[0039] The control unit 7 may be a dedicated component, or a vehicle control ECU and / or ABS control unit.

[0040] In this invention, the alarm for the timing of replacement of brake pads 4 and 5 based on their wear values ​​and remaining thickness can be implemented by a display unit 21 and an alarm unit 22 located on the dashboard or instrument panel, or by a separate display device or alarm device located outside the dashboard or instrument panel.

[0041] In this invention, the wear values ​​of brake pads 4 and 5 and the alarm signals for brake pad replacement timing transmitted to mobile terminal 24, specific terminal 26 or management server 27 are implemented by an application program set on mobile terminal 24 or specific terminal 26 or management server 27.

[0042] The present invention displays and alarms the wear values ​​of brake pads 4 and 5 measured by the wear sensor 9 installed at the caliper 1 of the disc brake and the brake pads 4 and 5 replacement timing alarm signal determined by the control unit 10 through the display unit 21 and alarm unit 22 installed on the instrument panel or dashboard. Thus, the wear amount or replacement timing of the brake pads 4 and 5 can be clearly grasped at a glance, and the brake pads 4 and 5 can be replaced in a timely manner, which has the effect of preventing vehicle accidents.

[0043] In addition, in this invention, the wear value signals of brake pads 4 and 5 measured by the wear sensor 9 of the caliper 1 installed on the disc brake, and the brake pad 4 and 5 replacement timing alarm signals determined by the control unit 10, are transmitted to the driver's mobile terminal 23 via the wireless communication module 23, or to a specific terminal 26 or vehicle management server 27 via the wireless communication module 23 and the wireless communication network 25. Thus, the wear amount or replacement timing of the brake pads 4 and 5 can be clearly understood, and corresponding measures can be taken or managed and database-ized.

[0044] Figure 5 The flowchart of the brake pad wear detection method for vehicles of the present invention is shown. The wear values ​​of brake pads 4 and 5 are measured by a wear sensor 9 installed at the caliper 1 of the disc brake (step a). The measured wear values ​​of brake pads 4 and 5 are input to the control unit 10 and monitored (step b). Brake pads 4 and 5 wear due to frequent braking (step c). The wear values ​​of brake pads 4 and 5 input to the control unit 10 are compared with a reference value (step d). When the wear values ​​of brake pads 4 and 5 input from the wear sensor 10 exceed the reference value, an alarm signal for replacement timing based on the remaining thickness of brake pads 4 and 5 is output (step e). Based on the alarm signal, an alarm is issued by the display unit 21 and the alarm unit 22 to indicate the replacement timing based on the wear of brake pads 4 and 5 (step f). The driver can recognize this and take appropriate measures by replacing brake pads 4 and 5, thereby preventing vehicle accidents caused by brake pad wear and protecting valuable lives and property.

[0045] Figure 6Another flowchart of the vehicle brake pad wear detection method of the present invention is shown. After step f) in which an alarm is issued by the display unit 21 and the alarm unit 22 according to the alarm signal to indicate the replacement timing of brake pads 4 and 5 based on wear, the alarm signal indicating the replacement timing based on the wear value and remaining thickness of brake pads 4 and 5 is transmitted to the mobile terminal 24 by the wireless communication module 23 of the control unit 7. Alternatively, after step f) in which an alarm is issued by the display unit 21 and the alarm unit 22 according to the alarm signal to indicate the replacement timing based on wear of brake pads 4 and 5, the alarm signal indicating the replacement timing based on the wear value and remaining thickness of brake pads 4 and 5 is transmitted to a specific terminal 26 and / or a management server 27 by the wireless communication module 23 and the wireless communication network 25 of the control unit 7 (step g). This allows for a clear understanding of the wear amount or replacement timing of brake pads 4 and 5, enabling the implementation of corresponding measures or management and database management.

[0046] This invention utilizes a permanent magnet and a Hall sensor located in an automatic gap adjustment device that maintains a constant gap between the brake pads and the brake disc to detect the wear of brake pads 4 and 5 in a non-contact manner and issue an alarm for when to replace them. As a result, compared with existing contact-type pad wear devices, it has the advantages of excellent accuracy in measuring the wear of brake pads (wear value), no temperature deviation, excellent durability, unaffected by vehicle vibration and impact, and significantly improved reliability.

[0047] The present invention described above is not limited to the embodiments and drawings described herein. Various substitutions, modifications and alterations can be made without departing from the technical concept of the present invention, which will be obvious to those skilled in the art.

Claims

1. A brake pad wear detection system for vehicles, wherein, include: A pair of backplates, which are arranged opposite each other inside the caliper; Brake pads, which are fixed to the front of the backplate; Brake disc, which is disposed between brake pads; A wear sensor, located at one end of the caliper, measures the amount of wear on the brake pads; as well as The control unit detects the amount of brake pad wear input from the wear sensor. When the brake pad wear value input from the wear sensor exceeds the reference value, it outputs a brake pad replacement timing alarm signal to the display unit and the alarm unit.

2. The vehicle brake pad wear detection system according to claim 1, wherein, Also includes: The wireless communication module, which is connected to the control unit, transmits the brake pad wear value and brake pad replacement timing alarm signal to the mobile terminal.

3. The vehicle brake pad wear detection system according to claim 1, wherein, Also includes: The wireless communication module, connected to the control unit, transmits brake pad wear values ​​and replacement timing warning signals to a specific terminal or vehicle management server via a wireless communication network.

4. The vehicle brake pad wear detection system according to any one of claims 1 to 3, wherein, The wear sensor includes: An automatic gap adjustment device is located at the caliper. The adjusting gear is located in the automatic clearance adjusting device; A connecting gear that meshes with an adjusting gear; The sensor shaft extends from the connecting gear and rotates in conjunction with it. The reducer has its shaft connected to the end of the sensor shaft. A permanent magnet, which is fixed to the output shaft of the reducer; and A Hall sensor, positioned opposite the permanent magnet, detects the rotating magnetic field of the permanent magnet.

5. A method for detecting wear on vehicle brake pads, wherein, Includes the following steps: a) The wear value of the brake pads is measured by a wear sensor located at the caliper of the disc brake; b) Input the measured brake pad wear value into the control unit and monitor it; c) Brake pads wear due to braking; d) The control unit compares the brake pad wear value input from the wear sensor with a reference value; e) When the brake pad wear value input from the wear sensor exceeds the reference value, a replacement timing alarm signal is output; as well as f) Based on the alarm signal, an alarm is issued through the display unit and the alarm unit to indicate when the brake pads need to be replaced.

6. The method for detecting wear of vehicle brake pads according to claim 5, wherein, Also includes: In f), after issuing an alarm on the brake pad replacement timing via the display unit and the alarm unit based on the alarm signal, the wear value and replacement timing alarm signal of the brake pad are transmitted to the mobile terminal via the wireless communication module of the control unit.

7. The method for detecting wear of vehicle brake pads according to claim 5, wherein, Also includes: In f), after issuing an alarm for the replacement timing through the display unit and the alarm unit based on the alarm signal, the wear value of the brake pads and the alarm signal for the replacement timing are transmitted to a specific terminal or vehicle management server stored in the control unit through the wireless communication module and wireless communication network of the control unit.

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