System and method for detecting vehicle brake pad wear

Abstract

The present invention relates to a system and method for detecting vehicle brake pad wear, in which a wear sensor is mounted on a brake caliper to monitor the amount of brake pad wear and provide a replacement time alert, thus enabling prevention of traffic accidents, etc., the system including: the wear sensor that is installed on one end of the disc brake caliper and measures the amount of brake pad wear; and a control unit that monitors the amount of brake pad wear, which is input from the wear sensor, and outputs an alert signal indicating a brake pad replacement time to a display unit and a warning unit when a brake pad wear value input from the wear sensor is greater than a reference value. The system may further include a wireless communication module that is connected to the control unit and transmits, to a mobile terminal, the alert signal indicating the replacement time based on the brake pad wear value and remaining thickness, and may further include a wireless communication module that is connected to the control unit and transmits, to a specific terminal or a vehicle management server, connected thereto via a wireless communication network, the alert signal indicating the replacement time based on the brake pad wear value and remaining thickness.

Description

Vehicle brake pad wear detection system and method thereof

[0001] The present invention relates to a brake pad wear detection system for a vehicle and a method thereof, wherein a wear sensor is installed in a caliper of a disc brake to monitor the amount of wear of the brake pad and to provide an alarm when the pad needs to be replaced, thereby preventing traffic accidents, etc.

[0002] Typically, vehicle braking occurs when the friction between the wheel disc and the brake pad reduces the wheel's rotational force. When the brake pedal is depressed, hydraulic pressure is transmitted through the brake pipe to the disc brake, compressing the disc against the brake pad, thus stopping the vehicle. As the vehicle brakes, brake pad wear occurs in proportion to the braking force.

[0003] In this way, when the brake pads wear out due to repeated braking of the vehicle, problems such as longer braking distance and uneven braking occur. In the case of high-load commercial vehicles, the risk of accidents increases due to the increased braking distance, so various technologies are being developed to measure the amount of brake pad wear.

[0004] However, as an example of a conventional brake pad wear detection device, when the brake pad reaches the wear limit, the tip of the sensor is worn out and cut, and a warning circuit is opened (On) to give a warning, and a warning light is turned on when the tip of the sensor comes into contact with the disc, but this has a problem in that the driver can only recognize it when the brake pad wear limit is reached, and in addition, a shaft connected to a slide of a linear variable resistor is installed on the brake pad, and the shaft and slide move as the brake pad wears, and the wear of the brake pad is detected by the resistance value of the linear variable resistor that changes, but while the structure is simple, there are several problems such as low sensitivity, large resistance fluctuations, and low reliability.

[0005] <Prior Art Literature>

[0006] (Patent Document 1) Republic of Korea Patent Publication No. 10-0123822 (Title of invention: Brake device equipped with friction pad wear detection sensor, patent announcement dated December 8, 1997)

[0007] (Patent Document 2) Republic of Korea Utility Model Publication No. 20-1998-0040781 (Title of invention: Brake pad replacement time warning device for automobile disc brake, Utility model published on September 15, 1998)

[0008] (Patent Document 3) Republic of Korea Patent Publication No. 10-2015-0137718 (Title of invention: Electronic caliper brake, published on December 9, 2015)

[0009] The problem to be solved by the present invention is to provide a vehicle brake pad wear detection system that can prevent traffic accidents, etc. by mounting a wear sensor on a brake caliper to monitor the amount of wear on the brake pad and alarming the time for replacement.

[0010] The brake pad wear detection system for a vehicle of the present invention comprises a pair of back plates installed oppositely inside a caliper, brake pads fixed to the front of the back plates, a brake disc installed between the brake pads, a wear sensor installed at one end of the caliper and measuring the amount of wear of the brake pads, and a control unit that monitors the amount of wear of the brake pads input from the wear sensor and outputs an alarm signal indicating the time for replacement according to the remaining thickness of the brake pads to a display unit and a warning unit when the brake pad wear value input from the wear sensor exceeds a reference value.

[0011] It further includes a wireless communication module that is connected to the above control unit and transmits a replacement time alarm signal according to the wear value and remaining thickness of the brake pad to a mobile terminal.

[0012] It further includes a wireless communication module that is connected to the above control unit and transmits a replacement time alarm signal according to the wear value and remaining thickness of the brake pad to a specific terminal or vehicle management server connected to a wireless communication network.

[0013] The above wear sensor includes an automatic gap adjusting device configured in the caliper, an adjusting gear configured in the automatic gap adjusting device, a connecting gear meshed with the adjusting gear, a sensor shaft rod extended from the connecting gear and rotating in conjunction with it, a reducer axially connected to an end of the sensor shaft rod, a permanent magnet fixed to an output shaft of the reducer, and a Hall sensor installed opposite the permanent magnet to detect a rotating magnetic field of the permanent magnet, and configured to measure a change in magnetic flux generated as the permanent magnet rotates by the Hall sensor and then convert it into a voltage for output, thereby obtaining a wear value of a brake pad whose thickness becomes thinner due to braking friction.

[0014] The method for detecting brake pad wear for a vehicle according to the present invention comprises the steps of: a) measuring the wear value of a brake pad with a wear sensor installed in a caliper of a disc brake; b) inputting the brake pad wear value measured in real time or non-real time into a control unit and monitoring it; c) causing the brake pad to wear out due to brake braking; d) comparing the wear value of the brake pad input from the wear sensor with a reference value by the control unit; e) outputting an alarm signal indicating the time for replacement according to the remaining thickness of the brake pad that has become thin when the wear value of the brake pad input from the wear sensor exceeds the reference value; and f) outputting an alarm signal indicating the time for brake pad replacement through a display unit and a warning unit by the alarm signal.

[0015] The step f) of notifying the replacement time through the display unit and the warning unit by the above alarm signal, further includes a step of transmitting an alarm signal for the replacement time based on (taking into account) the wear value and remaining thickness of the brake pad to a mobile terminal through the wireless communication module of the control unit.

[0016] The method further includes a step f) of transmitting a warning signal to a display unit and a warning unit by the above warning signal, and a step of transmitting an alarm signal indicating the replacement time according to the wear value and remaining thickness of the brake pad to a specific terminal or vehicle management server stored in the control unit through the wireless communication module and the wireless communication network of the control unit.

[0017] The present invention detects the amount of wear on the brake pads by a wear sensor mounted on the caliper of a disc brake and an alarm is given to indicate the time for replacement, so that the brake pads can be replaced in a timely manner, which is not only economical but also has the effect of protecting valuable human lives and property by preventing vehicle accidents, etc.

[0018] The present invention detects the amount of wear of brake pads (4)(5) in a non-contact manner using a permanent magnet and a hall sensor installed in an automatic gap adjusting device that maintains a constant gap between a brake pad and a brake disc, thereby alarming the time for replacement. Therefore, compared to a conventional contact-type pad wear device, the accuracy of measuring the amount of wear (wear value) of brake pads is superior, durability is excellent without temperature deviation, and reliability is greatly improved because there is no influence of vibration or shock of a vehicle, making it a very useful invention.

[0019] Figure 1: A cross-sectional diagram illustrating an example of the present invention.

[0020] Figure 2: A side cross-sectional diagram illustrating an example of the present invention.

[0021] Figure 3: Circuit block diagram illustrating an example of the present invention.

[0022] Figure 4: Circuit block diagram illustrating another example of the present invention.

[0023] Figure 5: System flow diagram illustrating an example of the present invention.

[0024] Figure 6: System flow diagram illustrating another example of the present invention.

[0025] <Explanation of symbols>

[0026] (1)--Caliper (2)(3)--Backplate

[0027] (4)(5)--Brake pad (6)--Brake disc

[0028] (7)--Pad automatic gap adjustment device (8)--Adjust gear

[0029] (9)--Wear sensor (10)--Control unit

[0030] (11)--Connecting gear (12)--Piston

[0031] (13)--Sensor shaft (14)--Reducer

[0032] (15)--Permanent magnet (16)--Hall sensor (Hall IC)

[0033] (20)--Settings section (21)--Display section

[0034] (22)--Warning unit (23)--Wireless communication module

[0035] (24)--Mobile terminal (25)--Wireless communication network

[0036] (26)--Specific terminal (27)--Management server

[0037] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. In describing the embodiments of the present invention, identical components in the drawings are denoted by the same reference numerals as much as possible, and detailed descriptions of related known structures or functions are omitted so as not to obscure the gist of the present invention. In addition, matters expressed in the attached drawings are schematic drawings for easy explanation of the embodiments of the present invention, and may differ from the form actually implemented.

[0038] FIG. 1 and FIG. 2 are diagrams illustrating a configuration of a brake pad wear detection system for a vehicle according to an example of the present invention, wherein a pair of back plates (2) (3) are installed oppositely inside a caliper (1) of a disc brake, brake pads (4) (5) are fixed to the front of the back plates (2) (3), a brake disc (6) is installed between the brake pads (4) (5), a wear sensor (9) installed in an adjuster gear (8) of an automatic brake pad gap adjusting device (7) provided in the caliper (1) to measure the amount of wear of the brake pads (4) (5), and a control unit (10) that monitors the amount of wear of the brake pads (4) (5) input from the wear sensor (9), and outputs a brake pad (4) (5) wear warning signal to a display unit and a warning unit when the wear value of the brake pads (4) (5) input from the wear sensor (9) exceeds a reference value.

[0039] The above brake disc and brake pad (4)(5) normally maintain a certain gap, but when the brake pad (4)(5) is worn beyond a certain level due to friction during braking, the automatic gap adjusting device (7) operates to maintain the gap between the brake disc and the brake pad (4)(5), and the front and rear back plates (2)(3) are brought closer by the rotating adjuster (8), so that the gap between the brake disc (6) and the brake pad (4)(5) is maintained at a certain level, thereby preventing a decrease in braking power (or loss of braking power) of the disc brake. When the brake pad (4)(5) is worn beyond a certain thickness due to frequent braking, the automatic gap adjusting device (7) operates again through the above process, so that the worn brake pad (4)(5) moves forward a certain distance, and the gap with the brake disc (6) is maintained at a certain level, thereby preventing a decrease in braking power.

[0040] The above brake pads (4)(5) are moved by an automatic gap adjusting device (7) to maintain a certain gap with the brake disc (6), but if the brake pads (4)(5) are excessively worn out due to frequent use, braking power may be lost, which may lead to a major accident. Therefore, in the present invention, a wear sensor (9) is installed in the automatic gap adjusting device (7) to detect the amount of wear of the brake pads (4)(5), and if the brake pads (4)(5) are excessively worn, this is detected and an alarm (warning) is generated to indicate the time for replacement.

[0041] The above automatic gap adjusting device (7) is configured such that the adjuster gear (8) rotates in one direction by a driving means (not shown), the connecting gear (11) meshed with the adjuster gear (8) rotates, and the piston (12) meshed with the connecting gear (11) in a ball screw structure moves forward to push the back plate (2) (3) so that the gap between the brake pad (4) (5) and the brake disc (6) is maintained constant, and a reducer (14) composed of a plurality of gears is connected to the end of a sensor shaft (13) that is extended or coupled to the one-side connecting gear (11) and rotates in conjunction, and a disk-shaped multi-pole permanent magnet (15) is installed on the output shaft of the reducer (14) to rotate at a reduced speed, and a Hall sensor (Hall IC) (16) is fixedly installed so as to be close and facing each other on the opposite side of the permanent magnet (15), and the Hall sensor (16) A wear sensor (9) is configured to obtain the wear value of a brake pad (4)(5) whose thickness becomes thin due to braking friction by measuring the rotating magnetic field (magnetic flux change) of a permanent magnet (15) and then converting it into a voltage and outputting it.

[0042] Even if the above connecting gear (11) rotates several times, the permanent magnet (15) is configured to rotate at an angle of less than 360° by the reducer (14), so that the Hall sensor (16) can accurately measure the rotating magnetic field (rotational displacement) of the permanent magnet (15).

[0043] When the above adjustment gear (8) and connecting gear (11) rotate, the piston (12) that is engaged with the connecting gear (11) in a ball screw structure moves forward in a straight line and pushes the back plate (2)(3), so that the gap between the brake pad and the brake disc is maintained constant.

[0044] The above wear sensor (9) is a rotation detection type that detects the amount of wear of the brake pads (4)(5) by detecting the amount of wear of the brake pads (4)(5) with a rotating magnetic field Hall sensor (16) of a permanent magnet installed on the output shaft of the reducer (14) and rotating at a reduced speed when the adjusting gear (8) rotates in order to maintain a constant gap between the brake pads and the brake disc, and is a non-contact type, so it has superior measurement precision compared to a conventional contact type wear sensor, and is not only durable without temperature deviation, but also can measure the amount of wear of the brake pads (4)(5) without being affected by vibrations and shocks of the vehicle, so it has high reliability.

[0045] FIG. 3 is an example of a circuit block of a brake pad wear detection system of the present invention. On the input side of the control unit (10), a wear sensor (5) that measures and inputs a wear value when the thickness of the brake pad (4) (5) is reduced due to friction, and a setting unit (20) that sets a wear reference value used as a reference value when determining the amount or degree of wear of the brake pad (4) (5) and a monitoring condition or status, etc. are connected.

[0046] The output side of the above control unit (7) includes a display unit (21) installed on the instrument panel or dashboard of the driver's seat and displaying the real-time or non-real-time wear amount of each brake pad using an indicator, seven-segment, LED, LCD, etc., a warning unit (22) that gives an alarm using a buzzer, siren, etc., indicating the replacement time according to the remaining thickness of the brake pad that has become thin due to wear, or the replacement time considering the remaining thickness of the brake pad, and a wireless communication module (23) that wirelessly transmits the wear value measured by the wear amount of the brake pad (4)(5) and a warning signal according to the remaining thickness to a portable terminal (24) carried by the driver.

[0047] The above control unit (10) monitors the wear value (wear amount) of the brake pad (4) (5) input from the wear sensor (9), and uses the control logic to display the wear value of the brake pad (4) (5) input from the wear sensor (9) on the display unit (21) and generate an alarm through the warning unit (22), so that the driver can immediately recognize it and replace the brake pad (4) (5) in a timely manner, thereby preventing a vehicle accident in advance.

[0048] The wear sensor (9) of the present invention is installed in the automatic gap adjustment device (7) to measure the wear value of the brake pad (4) (5) in a rotary, non-contact manner, thereby preventing wear or deformation of the wear sensor (9) / body shaking / noise, etc.

[0049] The above wireless communication module (23) may be RF Wifi, Bluetooth, USB, Beacon, RF WIFI (Radio Frequency Wireless Fidelity) with a communication distance of several kilometers, wireless data logger, etc.

[0050] The above beacon is a next-generation smartphone short-range communication technology using low-power Bluetooth, which searches for a mobile terminal (14) within a radius of 50 to 70 m (call connection) and transmits a replacement alarm signal considering the wear value and remaining thickness of the brake pad (4)(5).

[0051] The above warning unit (22) can issue an alarm or warning in various ways, such as not only auditory but also tactile methods that stimulate the driver's skin.

[0052] The wireless communication module (23) above can be applied to the brakes of the rear trailer when a trailer is connected to the rear of a tractor on which a driver is riding and towed, since a considerable distance is maintained between the tractor and the trailer, and the wear value of the brake pad (4)(5) measured by the wear sensor (9) and the replacement time alarm signal based on the remaining thickness by the control unit (10), or the replacement time alarm signal considering the remaining thickness of the brake pad (4)(5) is transmitted to the driver's portable terminal (24) through the wireless communication module (23), so that the driver or mechanic can recognize this and replace the brake pad (4)(5) in a timely manner, thereby preventing major accidents, etc.

[0053] FIG. 4 is a circuit block diagram of another embodiment of the brake pad wear detection system of the present invention, which can be configured to be transmitted to a specific terminal (26) of a manager (or a specific person) or a vehicle management server (27) via a wireless communication module (23) and a wireless communication network (15). By configuring the system so that the wear value signal of each brake pad (4)(5) and the replacement time alarm signal according to the remaining thickness are transmitted to a specific terminal (26) and / or a vehicle management server (17) via a wireless communication module (13) of a control unit (7) and a commercial or non-commercial wireless communication network (15), the wear status of the brake pads (4)(5) of vehicles belonging to cargo companies, bus companies, passenger transportation companies, taxi companies, etc. can be databased, and can be actively utilized for subsequent brake pad (4)(5) replacement, maintenance, etc., and vehicles belonging to the above companies are assigned and given an ID, which is a vehicle-specific identification code or code.

[0054] The above wireless communication network (15) may be for commercial or business purposes.

[0055] The permanent control unit (7) may be configured for a dedicated purpose or may be an ECU and / or ABS control unit for vehicle control.

[0056] In the present invention, the replacement time alarm according to the wear value and remaining thickness of the brake pad (4)(5) may be implemented through a display unit (21) and a warning unit (22) installed on an instrument panel or dashboard, or may be a separate display device or alarm device installed other than the instrument panel or dashboard.

[0057] In the present invention, the wear value of the brake pad (4)(5) and the brake pad (4)(5) replacement time alarm signal transmitted to the mobile terminal (24) or specific terminal (26) or management server (27) are implemented as an app installed on the mobile terminal (24) or specific terminal (26) or an application program of the management server (27).

[0058] The present invention displays and alarms a wear value signal of a brake pad (4)(5) measured by a wear sensor (9) installed in a caliper (1) of a disc brake and a brake pad (4)(5) replacement time alarm signal determined by a control unit (10) through a display unit (21) and a warning unit (22) installed on an instrument panel or dashboard, so that the amount of wear and replacement time of the brake pad (4)(5) can be clearly identified at a glance, and the brake pad (4)(5) can be replaced in a timely manner, thereby preventing vehicle accidents.

[0059] In addition, the present invention transmits a wear value signal of a brake pad (4)(5) measured by a wear sensor (9) installed in a caliper (1) of a disc brake and an alarm signal indicating the time to replace a brake pad (4)(5) determined by a control unit (10) to a driver's mobile terminal (23) through a wireless communication module (23), or to a specific terminal (26) or a vehicle management server (27) through a wireless communication module (23) and a wireless communication network (25), so that the amount of wear or the time to replace a brake pad (4)(5) can be clearly identified and corresponding measures can be taken or managed and stored in a database.

[0060] FIG. 5 is a flow chart illustrating a method for detecting wear of brake pads for a vehicle according to the present invention, in which the wear value of the brake pads (4) (5) is measured by a wear sensor (9) installed in a caliper (1) of a disc brake (step a), the measured wear value of the brake pads (4) (5) is input to a control unit (10) and monitored (step b), the brake pads (4) (5) are worn out by frequent braking (step c), the wear value of the brake pads (4) (5) input to the control unit (10) is compared with a reference value (step d), and when the wear value of the brake pads (4) (5) input from the wear sensor (10) exceeds the reference value, an alarm signal indicating the replacement time according to the remaining thickness of the brake pads (4) (5) is output (step e), and the replacement time according to the wear of the brake pads (4) (5) is alarmed by the alarm signal to the display unit (21) and the warning unit (22), so that the driver recognizes this and replaces the brake pads (4) (5), etc. By taking countermeasures in this way, vehicle accidents caused by wear of brake pads (4)(5) are prevented, and valuable lives and property are protected.

[0061] FIG. 6 is a flowchart illustrating a method for detecting wear of brake pads for vehicles according to the present invention, wherein, after step f) in which the replacement time according to wear of the brake pads (4)(5) is notified to the display unit (21) and the warning unit (22) by the alarm signal, an alarm signal according to the wear value and remaining thickness of the brake pads (4)(5) is transmitted to a mobile terminal (24) through the wireless communication module (23) of the control unit (7), or, after step f) in which the replacement time according to wear of the brake pads (4)(5) is notified to the display unit (21) and the warning unit (22) by the alarm signal, the wear value of the brake pads (4)(5) and the replacement time according to the remaining thickness of the brake pads (4)(5) are transmitted to a specific terminal (26) and / or a management server (27) through the wireless communication module (23) of the control unit (7) and a wireless communication network (25) (step g), thereby detecting the wear amount or replacement of the brake pads (4)(5). You can clearly see the timing and take action to manage and store it in a database.

[0062] The present invention detects the amount of wear of brake pads (4)(5) in a non-contact manner using a permanent magnet and a hall sensor installed in an automatic gap adjusting device that maintains a constant gap between a brake pad and a brake disc, thereby alarming the time for replacement. Therefore, compared to a conventional contact-type pad wear device, the accuracy of measuring the amount of wear (wear value) of brake pads is superior, durability is excellent without temperature deviation, and reliability is greatly improved because there is no influence of vibration or shock of a vehicle.

[0063] The present invention described above is not limited to the present embodiment and the attached drawings, and various substitutions, modifications, and changes are possible within the scope that does not depart from the technical spirit of the present invention, which will be apparent to those skilled in the art to which the present invention pertains.

Claims

1. A pair of back plates installed oppositely inside the caliper; Brake pads that are fixed to the front of the backplate; A brake disc installed between brake pads; A wear sensor installed on one end of the caliper and measuring the amount of wear of the brake pad; and A control unit that monitors the amount of brake pad wear input from a wear sensor and outputs an alarm signal indicating the time to replace the brake pad through a display unit and a warning unit when the brake pad wear value input from the wear sensor exceeds a reference value; A brake pad wear detection system for a vehicle including:

2. In claim 1; A wireless communication module connected to the above control unit and transmitting a brake pad wear value and a brake pad replacement time alarm signal to a mobile terminal; A brake pad wear detection system for a vehicle further comprising:

3. In claim 1; A wireless communication module connected to the above control unit and transmitting a brake pad wear value and a replacement time alarm signal to a specific terminal or vehicle management server connected to a wireless communication network; A brake pad wear detection system for a vehicle further comprising:

4. In any one of claims 1 to 3; The above wear sensor, An automatic gap adjusting device configured in a caliper; Adjusting gear configured in an automatic gap adjusting device; Connecting gear meshed with adjusting gear; A sensor shaft rod that extends to the connecting gear and rotates in conjunction with it; A reducer connected to the shaft end of the sensor shaft; A permanent magnet fixed to the output shaft of the reducer; and A Hall sensor installed opposite a permanent magnet to detect the rotating magnetic field of the permanent magnet; A brake pad wear detection system for a vehicle including: 5.a) A step of measuring the wear value of the brake pad using a wear sensor installed in the caliper of the disc brake; b) A step in which the measured brake pad wear value is input into the control unit and monitored; c) The stage where the brake pads are worn out by braking; d) a step of comparing the wear value of the brake pad input from the wear sensor with the reference value by the control unit; e) a step for outputting a replacement time alarm signal when the wear value of the brake pad input from the wear sensor exceeds the reference value; and f) A step in which the brake pad replacement time is notified by the display unit and warning unit through an alarm signal; A method for detecting brake pad wear for a vehicle, comprising:

6. In claim 5; Step f) after the replacement time is notified to the display unit and warning unit by the above alarm signal, a step of transmitting the brake pad wear value and replacement time alarm signal to a mobile terminal through the wireless communication module of the control unit; A method for detecting brake pad wear for a vehicle further comprising:

7. In claim 5; Step f) after the replacement time is notified by the display unit and warning unit through the above alarm signal, a step of transmitting the brake pad wear value and the replacement time alarm signal to a specific terminal stored in the control unit or a vehicle management server through the wireless communication module of the control unit and the wireless communication network; A method for detecting brake pad wear for a vehicle further comprising:

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