Vehicle brake device and apparatus and method for calibrating brake force of brake device to zero point

Abstract

Provided are a vehicle brake device, and an apparatus and method for calibrating a brake force of the brake device to zero. The vehicle brake device includes a caliper body configured to surround a brake disc; a pair of brake pads arranged to face each other in the caliper body and positioned on opposite sides of the brake disc, respectively; a screw lever installed in the caliper body and configured to be rotatable by power from a motor unit; a nut unit configured to be linearly moved by rotation of the screw lever; a piston unit configured to surround an outside of the nut unit and to press either of the pair of brake pads by moving together with the nut unit; a bearing unit configured to support rotation of the screw lever and to be moved by repulsive force of the screw lever; and a load switch unit installed in the caliper body, arranged to face the bearing unit, and configured to be operated by being pressed by the bearing unit. A control unit can identify a time point at which a brake force is generated and released using the load switch unit.

Description

Technical Field

[0001] Exemplary embodiments of this disclosure relate to vehicle braking devices and apparatus and methods for calibrating the braking force of the braking device to zero. More specifically, they relate to vehicle braking devices and apparatus and methods for calibrating the braking force of the braking device to zero, which are capable of reducing ineffective travel and calibrating the estimated time point at which the load is generated by the motor current by using the time point at which the load is actually generated on the brake pads. Background Technology

[0002] Generally, vehicle electromechanical brakes (EMBs) use a screw-nut mechanism to convert the rotational force of the drive motor into linear motion to press a piston. The pressed piston then forces brake pads, which act as friction components, against the wheel disc, thereby generating braking force.

[0003] Existing electromechanical brakes struggle to estimate the position related to the timing of braking force generation and release, relying solely on control information applied to the motor. Furthermore, the initial position cannot be calibrated based on brake pad wear.

[0004] In addition, existing vehicle electromechanical brakes generate a load by controlling the current of a motor to linearly push the brake pads in a mechanically converted rotational manner.

[0005] However, existing vehicle electromechanical brakes cannot estimate the position related to the actual timing of the generation and release of braking force; they can only estimate it based on control information applied to the motor. Furthermore, existing vehicle electromechanical brakes cannot estimate the actual braking force during driver braking operations solely by operating a load switch.

[0006] The background technology of this disclosure is disclosed in Korean Patent 10-0456779 (registered on April 29, 2004, entitled "Braking Device for Vehicles"). Summary of the Invention

[0007] Various embodiments relate to a vehicle braking device that can reduce initial inefficiency, i.e., invalid stroke, by identifying the time points at which braking force is generated and released, and resetting and restoring the initial time point of the operation based on those time points.

[0008] Various embodiments also relate to an apparatus and method for calibrating the braking force of a vehicle braking device to zero, the apparatus and method being able to calibrate the estimated time point at which the load is generated by the motor current by using the time point at which the load is actually generated on the brake pads of the vehicle braking device.

[0009] In one embodiment, a vehicle braking device includes: a caliper body configured to surround a brake disc; a pair of brake pads arranged in the caliper body facing each other and positioned on opposite sides of the brake disc; a lever mounted in the caliper body and configured to rotate by means of power from a motor unit; a nut unit configured to move linearly by means of rotation of the lever; a piston unit configured to surround the outside of the nut unit and to press either of the pair of brake pads by moving together with the nut unit; a bearing unit configured to support rotation of the lever and to move by means of the repulsive force of the lever; and a load switch unit mounted in the caliper body, arranged to face the bearing unit, and configured to be operated by being pressed by the bearing unit.

[0010] Furthermore, the braking device may further include a control unit configured to receive an electrical signal from the load switch unit and control the operation of the motor unit based on the electrical signal.

[0011] Furthermore, the load switch unit may include: a housing portion mounted in the caliper body; a movable block portion mounted in the housing portion, the movable block portion being configured to move by being pressed by the bearing unit, the movable block portion being configured to return to its original position by means of an elastic restoring force when the bearing unit is released; and a connector portion configured to transmit the electrical signal to the control unit by contacting the movable block portion when the movable block portion moves.

[0012] Furthermore, the movable block portion can protrude outside the housing portion.

[0013] In addition, the movable block portion may include: a movable block movably disposed in the housing portion and configured to contact the connector portion; and an elastic member connected to the movable block, coupled to the connector portion, and configured to elastically support the movable block.

[0014] Furthermore, the connector portion may include: a connector body connected to the elastic member; and a contact portion disposed in the connector body and configured to generate the electrical signal by contacting the movable block.

[0015] In addition, the movable block may include: a movable block body elastically supported by the elastic member; and a conductor plate mounted in the movable block body and configured to contact the contact portion.

[0016] Furthermore, the contact portion may include: a contact protrusion disposed in the connector body and configured to contact the conductor plate; and a terminal connected to the contact protrusion and configured to transmit the electrical signal to the control unit, wherein the electrical signal is generated between the contact protrusion and the conductor plate when the conductor plate contacts the contact protrusion.

[0017] In one embodiment, an apparatus for calibrating the braking force of a vehicle braking device to zero includes: a load switching unit configured to output an electrical signal when a brake pad actually presses against a brake disc and a lever moves backward by a repulsive force; a motor current measuring unit configured to measure a motor current of a motor that causes the lever to rotate, thereby causing the brake pad to press against the brake disc; and a control unit configured to estimate an estimated load applied to the lever with respect to each motor current during operation of the motor, and to calibrate the estimated load to zero based on the electrical signal.

[0018] The control unit according to this disclosure can calibrate the estimated load to zero based on the estimated load estimated at the time point at which the electrical signal is input.

[0019] When the estimated load is not 0 at the time point at which the electrical signal is input, the control unit according to this disclosure can calibrate the estimated load to 0 at the time point at which the electrical signal is input.

[0020] The control unit according to this disclosure can calibrate all estimated loads for each motor current based on a zero point calibrated at the time point at which the electrical signal is input.

[0021] When the estimated load remains at 0 for a predetermined time or longer after the input of the electrical signal, the control unit according to this disclosure can determine that the motor current monitoring function of the motor current measurement unit has malfunctioned.

[0022] In one embodiment, a method for calibrating the braking force of a vehicle braking device to zero includes the following steps: when a motor rotates a lever such that a brake pad presses against a brake disc, a motor current measuring unit measures the motor current of the motor, and a control unit detects an estimated load applied to the lever for each motor current measured by the motor current measuring unit; when the brake pad actually presses against the brake disc and the lever moves backward by a repulsive force, a load switching unit outputs an electrical signal; and when the electrical signal is input from the load switching unit, the control unit performs zero-point calibration of the estimated load based on the time point at which the electrical signal is input.

[0023] The step of zero-point calibration of the estimated load according to this disclosure may include zero-point calibration of the estimated load based on the estimated load estimated at the time point at which the electrical signal is input.

[0024] The step of zero-point calibration of the estimated load according to this disclosure may include calibrating the estimated load at the time point of input of the electrical signal to 0 when the estimated load at the time point of input of the electrical signal is not 0.

[0025] According to this disclosure, in the step of performing zero-point calibration on the estimated load, the control unit can perform zero-point calibration for all estimated loads for each motor current based on the zero-point calibration calibrated at the time point at which the electrical signal is input.

[0026] The method according to this disclosure may further include the following steps: when the estimated load remains at 0 for a predetermined time or longer after the input of the electrical signal, the control unit determines that the motor current monitoring function of the motor current measurement unit has malfunctioned.

[0027] According to the vehicle braking device disclosed herein, the control unit can use a load switch unit to identify the timing points of generating and releasing braking force. Therefore, the control unit does not always return the position of the lead lever to the initial timing point of generating braking force, but instead resets the initial timing point of the operation based on the timing point of releasing braking force, and then returns the position of the lead lever to the reset timing point, thereby reducing initial inefficiency, i.e., invalid travel.

[0028] Furthermore, in this disclosure, the initial timing of the lever operation is reset based on the wear of the brake pads, which enables the reduction of invalid travel in subsequent braking operations.

[0029] The apparatus and method for calibrating the braking force of a vehicle braking device to zero according to this disclosure can calibrate the estimated time point at which the load is generated by the motor current by using the actual time point at which the load is generated on the brake pads of the vehicle braking device, thereby reducing initial invalidity and improving the accuracy of the calculated output load. Attached Figure Description

[0030] Figure 1 This is a perspective view of a vehicle braking device according to one embodiment of the present disclosure.

[0031] Figure 2 It is along Figure 1 A sectional view cut by line A-A'.

[0032] Figure 3 yes Figure 2 An enlarged view of part A in the image.

[0033] Figure 4 This is a half-section perspective view of a vehicle braking device according to an embodiment of the present disclosure.

[0034] Figure 5 This is an exploded perspective view of the main parts of a vehicle braking device according to an embodiment of the present disclosure.

[0035] Figure 6 This is a perspective view showing the load switch unit of a vehicle braking device according to an embodiment of the present disclosure.

[0036] Figure 7 This is an exploded perspective view of the load switch unit of a vehicle braking device according to an embodiment of the present disclosure.

[0037] Figure 8 When viewed from another direction Figure 7 A three-dimensional image.

[0038] Figure 9 This is a view showing the operating state of the load switch unit when the vehicle braking device according to an embodiment of the present disclosure is performing a braking operation.

[0039] Figure 10 yes Figure 9 A magnified view of part B in the image.

[0040] Figure 11 This is a block diagram of a device for calibrating the braking force of a vehicle braking device to zero, according to an embodiment of the present disclosure.

[0041] Figure 12 This is a flowchart of a method for calibrating the braking force of a vehicle braking device to zero according to an embodiment of the present disclosure. Detailed Implementation

[0042] The following description, with reference to the accompanying drawings, details a vehicle braking device according to one embodiment of the present disclosure, as well as the apparatus and method for calibrating the braking force of the braking device to zero. For clarity and convenience, the thickness of lines, the dimensions of components, etc., shown in the figures may be exaggerated. Furthermore, the terminology used below is defined in consideration of its function in this disclosure and may be varied according to the intentions or common practice of the user or operator. Therefore, these terms should be defined based on the overall content of this specification.

[0043] Figure 1 This is a perspective view of a vehicle braking device according to one embodiment of the present disclosure. Figure 2 It is along Figure 1 A sectional view cut by line A-A' in the middle. Figure 3 yes Figure 2 A magnified view of part A in the image. Figure 4This is a half-sectional perspective view of a vehicle braking device according to an embodiment of the present disclosure. Figure 5 This is an exploded perspective view of the main parts of a vehicle braking device according to an embodiment of the present disclosure. Figure 6 This is a perspective view showing the load switch unit of a vehicle braking device according to an embodiment of the present disclosure. Figure 7 This is an exploded perspective view of the load switch unit of a vehicle braking device according to an embodiment of the present disclosure. Figure 8 When viewed from another direction Figure 7 3D image, Figure 9 This is a view showing the operating state of the load switch unit when the vehicle braking device according to an embodiment of the present disclosure is performing a braking operation, and Figure 10 yes Figure 9 A magnified view of part B in the image.

[0044] Reference Figures 1 to 10 According to one embodiment of the present disclosure, a vehicle braking device 1 includes a caliper body 100, a pair of brake pads 200, a lever 300, a nut unit 400, a piston unit 500, a bearing unit 600, a load switch unit 700, and a control unit 800 (in... Figure 11 (As shown in the diagram). Caliper body 100 surrounds brake disc 10. Caliper body 100 includes a first caliper body 110 and a second caliper body 120.

[0045] Lever 300, nut unit 400, piston unit 500, bearing unit 600, load switch unit 700, and motor unit 900 (in...) Figure 11 (As shown in the diagram) It is installed in the first caliper body 110. The second caliper body 120 is connected to the first caliper body 110 and is installed facing a pair of brake pads 200.

[0046] The pair of brake pads 200 are arranged facing each other in the caliper body 100 and are located on opposite sides of the brake disc 10. Specifically, each brake pad 200 includes a backing plate 210 and a friction member 220. The backing plate 210 faces the piston unit 500, which will be described below. The backing plate 210 is pressed by the piston unit 500.

[0047] The friction member 220 is connected to the surface of the back plate 210 facing the brake disc 20. The friction member 220 can contact the brake disc 10.

[0048] The lever 300 is mounted in the caliper body 100 and can be rotated by power from the motor unit 900. The lever 300 has a rod shape and is inserted into the nut unit 400, which will be described below. An external thread (not shown) is provided on the outside of the lever 300, and the lever 300 rotates by rotational force transmitted from the motor unit 900, which will be described below.

[0049] The motor unit 900 transmits power to the lead lever 300. The motor unit 900 includes a motor 910 and a gear module 920. The gear module 920 includes a plurality of gears, any one of which is connected to the motor 910, and another of the gears is connected to the lead lever 300. That is, the gear module 920 receives rotational force from the motor 910 and causes the lead lever 300 to rotate.

[0050] The nut unit 400 moves linearly by means of the rotation of the lead lever 300. The nut unit 400 surrounds the outside of the lead lever 300 and selectively moves toward or away from the brake pad 200 depending on the direction of rotation of the lead lever 300.

[0051] Specifically, when the lead lever 300 rotates in a predetermined direction, the nut unit 400 moves toward the brake pad 200 by converting the rotational motion of the lead lever 300 into linear motion. Conversely, when the lead lever 300 rotates in the opposite direction to the predetermined direction, the nut unit 400 moves away from the brake pad 200.

[0052] The piston unit 500 is shaped to surround the outside of the nut unit 400 and presses either of the pair of brake pads 200 by moving together with the nut unit 400. The piston unit 500 has a cylindrical shape, with the portion of the piston unit 500 for insertion into the nut unit 400 being open and the portion of the piston unit 500 facing the brake pad 200 being closed.

[0053] The piston unit 500 moves together with the nut unit 400 to apply pressure to the brake pad 200 by being pressed by the nut unit 400, or to release the pressure applied to the brake pad 200 by being released from the nut unit 400. The piston unit 500 moves toward or away from the brake pad 200 by being pressed by the nut unit 400.

[0054] When the piston unit 500 presses down on the brake pad 200, the brake pad 200 comes into contact with the brake disc 20, thereby generating braking force. That is, when the piston unit 500 presses down on the back plate 210 of the brake pad 200, the friction member 220 of the brake pad 200 comes into contact with the brake disc 20.

[0055] The bearing unit 600 (thrust bearing) supports the rotation of the lead lever 300 and moves by means of the repulsive force of the lead lever 300. Specifically, when the piston unit 500 comes into close contact with the brake pad 200 and presses the brake pad 200, the repulsive force is applied to the lead lever 300, and the lead lever 300 moves backward.

[0056] Therefore, the bearing unit 600 moves backward and presses the load switch unit 700. That is, the control unit 800, which will be described below, can measure the timing of the braking force.

[0057] The load switch unit 700 is installed in the caliper body 100, arranged to face the bearing unit 600, and is operated by being pressed by the bearing unit 600.

[0058] The load switch unit 700 includes a housing portion 710, a movable block portion 720, and a connector portion 730. The housing portion 710 is mounted in the first clamp body 110 of the clamp body 100.

[0059] The housing portion 710 has an annular shape and a mounting hole 711, in which the movable block portion 720, described below, is mounted. A through hole 712 is formed at the central portion of the housing portion 710, and the lever 300 passes through the through hole 712.

[0060] The movable block portion 720 is mounted in the housing portion 710 and is moved by being pressed by the bearing unit 600. When the pressure applied to the bearing unit 600 is released, the movable block portion 720 returns to its original position by means of an elastic restoring force.

[0061] When the bearing unit 600 moves with the repulsive force of the lever 300 and presses the movable block portion 720, the movable block portion 720 moves backward and comes into contact with the connector portion 730, which will be described below. In this case, the point in time at which the repulsive force of the lever 300 is generated is the point in time at which the piston unit 500 comes into close contact with the brake pad 200 and presses the brake pad 200 to generate braking force.

[0062] Subsequently, as the piston unit 500 releases the brake pads 200 and thus releases the braking force, the bearing unit 600 releases the movable block portion 720, and the bearing unit 600 returns to its original position by means of the elastic restoring force of the elastic member 722, which will be described below. This point in time is the point at which the braking force is released.

[0063] The movable block portion 720 protrudes outside the housing portion 710. Therefore, when the bearing unit 600 moves by means of the repulsive force of the lever 300, the movable block portion 720 is pressed down.

[0064] The movable block portion 720 includes a movable block 721 and an elastic member 722. The movable block 721 is movably arranged in the housing portion 710 and contacts the connector portion 730.

[0065] The movable block 721 includes a movable block body 721a and a conductor plate 721d. The movable block body 721a is elastically supported by an elastic member 722. The movable block body 721a includes a first movable block body 721b and a second movable block body 721c.

[0066] The first movable block body 721b is movably arranged in the mounting hole 711 of the housing portion 710. The second movable block body 721c is connected to the first movable block body 721b, and the conductor plate 721d, which will be described below, is mounted on one side of the second movable block body 721c.

[0067] Conductor plate 721d is mounted on movable block body 721a and contacts contact portion 732. Conductor plate 721d is mounted on a second movable block body 721c of movable block body 721a and contacts connector portion 730 by means of movement of movable block 721.

[0068] The elastic member 722 (spring) is connected to the movable block 721. The elastic member 722 is connected to the connector portion 730 and elastically supports the movable block 721. Therefore, when the pressing force applied to the movable block 721 by the bearing unit 600 is released, the movable block 721 can return to its original position.

[0069] When the movable block portion 720 moves, the connector portion 730 transmits electrical signals to the control unit 800 by contacting the movable block portion 720.

[0070] The connector portion 730 includes a connector body 731 and a contact portion 732. An elastic member 722 is attached to the connector body 731. The connector body 731 includes a first connector body 731a, a connecting plate 731b, and a second connector body 731c.

[0071] The contact portion 732, described below, is mounted in the first connector body 731a. A connecting plate 731b is connected to the first connector body 731a and is coupled to the elastic member 722. The second connector body 731c has a cylindrical shape. The second connector body 731c is connected to the connecting plate 731b and surrounds the contact portion 732.

[0072] Contact portions 732 are installed in connector body 731 and generate electrical signals by contacting movable block 721. Multiple contact portions 732 are provided, and the multiple contact portions 732 are installed in a first connector body 731a of connector body 731 and spaced apart from each other.

[0073] The contact portion 732 includes contact protrusions 732a and terminals 732b. The contact protrusions 732a are mounted in the connector body 731 and contact the conductor plate 721d. There are multiple contact protrusions 732a, and the multiple contact protrusions 732a are mounted in a first connector body 731a of the connector body 731 and spaced apart from each other.

[0074] Terminal 732b is connected to contact protrusion 732a. When conductor plate 721d contacts contact protrusion 732a, terminal 732b transmits the electrical signal generated between contact protrusion 732a and conductor plate 721d to control unit 800, which will be described below. Multiple terminals 732b are provided, and each terminal 732b is connected to contact protrusion 732a. A second connector body 731c of connector body 731 surrounds the exterior of terminal 732b.

[0075] The control unit 800 receives an electrical signal from the load switch unit 700 and controls the operation of the motor unit 900 based on the electrical signal. Specifically, based on the electrical signal transmitted from the load switch unit 700, the control unit 800 can predict the timing of generating braking force.

[0076] Conversely, when the control unit 800 does not receive an electrical signal from the load switch unit 700, the control unit 800 can predict the timing of the release of the braking force. The control unit 800 can predict the timing of the generation and release of the braking force, and calibrate the position of the lead lever 300 by controlling the operation of the motor unit 900.

[0077] In this scenario, the control unit 800 does not always return the position of the lever 300 to the initial time point of generating braking force. Instead, it resets the initial time point of operation based on the time point of releasing braking force, and then returns the position of the lever 300 to the reset time point, thereby reducing initial inefficiency, i.e., invalid travel. Furthermore, the initial time point of operation of the lever 300 is reset based on the wear of the brake pads 200, which further reduces invalid travel in subsequent braking operations.

[0078] Below, we will refer to Figure 2 , Figure 3 , Figure 9 and Figure 10 The operation and effects of a vehicle braking device according to an embodiment of the present disclosure are described.

[0079] To brake the vehicle, the lead lever 300 rotates in a predetermined direction with the power from the motor unit 900. When the lead lever 300 rotates in the predetermined direction, the nut unit 400 and the piston unit 500 move toward the brake pad 200, and the piston unit 500 presses the brake pad 200.

[0080] Brake pad 200 contacts brake disc 10, generating braking force. In this situation, when piston unit 500 presses brake pad 200, repulsive force is applied to piston unit 500 and nut unit 400, and also to screw lever 300.

[0081] The bearing unit 600 moves backward by means of the repulsive force of the lever 300, and the bearing unit 600 presses the load switch unit 700, thereby activating the load switch unit 700. That is, the load switch unit 700 is operated by means of the load on the bearing unit 600.

[0082] The load switch unit 700 transmits an electrical signal to the control unit 800. The control unit 800 can predict the timing of the braking force based on the electrical signal transmitted from the load switch unit 700 and display the prediction result on a monitoring unit (not shown).

[0083] Subsequently, when the lever 300 rotates in the opposite direction to the predetermined direction with the help of the power from the motor unit 900 during the brake release operation, the nut unit 400 and the piston unit 500 move away from the brake pad 200, and the brake pad 200 is released.

[0084] When the brake pad 200 is released, the bearing unit 600 returns to its original position, the bearing unit 600 stops pressing the load switch unit 700, and the load switch unit 700 stops operating.

[0085] The load switch unit 700 does not transmit electrical signals to the control unit 800, and the control unit 800 can predict the time when the braking force is released and display the prediction result on the monitoring unit (not shown).

[0086] As described above, the control unit 800 uses the load switch unit 700 to predict the timing of generating braking force and releasing braking force, and calibrates the position of the lever 300 by controlling the operation of the motor unit 900 based on the prediction results.

[0087] The control unit 800 does not always return the position of the lever 300 to the initial time point of generating braking force by operating the motor unit 900. Instead, it resets the initial time point of operation based on the time point of releasing braking force and then returns the position of the lever 300 to the reset time point of operation.

[0088] Therefore, initial inefficiency, i.e., wasted travel, can be reduced. Furthermore, the initial timing of the operation of the lever 300 is reset based on the wear of the brake pads 200, which reduces wasted travel in subsequent braking operations.

[0089] Figure 11This is a block diagram of a device for calibrating the braking force of a vehicle braking device to zero, according to an embodiment of the present disclosure.

[0090] Reference Figure 11 According to embodiments of the present disclosure, an apparatus for calibrating the braking force of a vehicle braking device to zero includes a load switch unit 700, a control unit 800, a motor unit 900, a motor current measuring unit 1000, and an output unit 1100.

[0091] In this case, since the load switch unit 700 and the motor unit 900 are the same as the corresponding units in the above embodiment, their detailed description will be omitted.

[0092] The motor current measuring unit 1000 measures the motor current (which is applied when the motor 910 is operating) and inputs the measured motor current to the control unit 800.

[0093] Output unit 1100 outputs the results of monitoring the motor current. For example, when control unit 800 determines that the motor current monitoring function is faulty, output unit 1100 notifies the occupants of the motor current monitoring function failure via image or sound based on the control signal from control unit 800. In this case, the occupants can recognize the failure of the function.

[0094] The output unit 1100 may be, but is not particularly limited to, a vehicle instrument panel (not shown).

[0095] The control unit 800 rotates the lead lever 300 by operating the motor 910. The nut unit 400 moves linearly as the lead lever 300 rotates with the power from the motor unit 900. Depending on the direction of rotation of the lead lever 300, the nut unit 400 moves toward the brake pad 200 to press the brake pad 200, or moves away from the brake pad 200 to release the brake pad 200.

[0096] The control unit 800 can receive electrical signals from the load switch unit 700 and control the operation of the motor unit 900 based on the electrical signals.

[0097] In this case, the control unit 800 receives the motor current measured by the motor current measuring unit 1000 and estimates the load of the bearing unit 600 based on the motor current.

[0098] The control unit 800 can detect the estimated load that is expected to be applied to the wire lever 300 for each motor current by storing the load for each motor current in the form of a lookup table or by calculating the load based on the motor current.

[0099] There are no particular limitations to the method of estimating the load of bearing unit 600 based on motor current.

[0100] Meanwhile, the control unit 800 receives electrical signals from the load switch unit 700 as described above through the operation of the motor unit 900.

[0101] That is, in order to brake the vehicle, the lever 300 rotates in a predetermined direction with the power from the motor unit 900, the nut unit 400 and the piston unit 500 move toward the brake pad 200, and the piston unit 500 presses the brake pad 200.

[0102] When the brake pad 200 contacts the brake disc 10, braking force is generated. When the piston unit 500 presses down on the brake pad 200, a repulsive force is applied to the piston unit 500 and the nut unit 400, and the repulsive force is also applied to the lever 300.

[0103] The bearing unit 600 moves backward by the repulsive force of the lever 300, and presses the load switch unit 700, thereby activating the load switch unit 700 and inputting an electrical signal to the control unit 800. As described above, when the operation of the motor unit 900 actually generates a load, an electrical signal is input to the control unit 800.

[0104] Therefore, based on the electrical signal input from the load switch unit 700 according to the actual generated load, the control unit 800 can calibrate the zero point of the estimated load based on the motor current estimation, and calibrate the origin of the braking force. That is, when the braking force is generated by actually controlling the motor 910, the control unit 800 performs zero-point calibration on the initial braking force.

[0105] The timing of the electrical signal input from the load switch unit 700 is the timing of the actual load generation. The control unit 800 calibrates the estimated load based on the motor current estimation to 0 at the timing of the electrical signal input from the load switch unit 700, thereby performing zero-point calibration on the current based on the motor current estimation. Therefore, the control unit 800 performs zero-point calibration on the initial braking force when actually controlling the motor 910 to generate braking force.

[0106] For example, when the motor operates with current applied to it by the control unit 800, the motor current measuring unit 1000 measures the motor current.

[0107] In this case, the control unit 800 estimates the load based on the measured motor current, and the estimated load may be greater than 0.

[0108] However, when an electrical signal is input from the load switch unit 700 during this process, it can be seen that the load estimated based on the motor current is incorrect because the time point of inputting the electrical signal is the time point when the load is actually generated.

[0109] Therefore, when the estimated load is greater than 0 at the time point when the electrical signal is input from the load switch unit, the control unit 800 will calibrate the estimated load based on the motor current estimate to 0.

[0110] In addition, the control unit 800 can calibrate all estimated loads for each motor current by calibrating a lookup table or calculation formula used to estimate the load based on the motor current.

[0111] The estimated load at the point in time of the input electrical signal may contain an error. For example, the control unit 800 can calibrate all estimated loads for each motor current by subtracting the estimated load (error) at the point in time of the input electrical signal from the various estimated loads in the lookup table.

[0112] Meanwhile, when the electrical signal input from the load switch unit 700 exceeds 0, and the estimated load based on the current motor current estimate remains at 0 for a predetermined time or longer, the control unit 800 determines that the motor current monitoring function of the motor current measurement unit 1000 is faulty.

[0113] Normally, the motor operates with the help of motor current and the piston moves before the circuit of the load switch unit 700 is closed.

[0114] Therefore, when an electrical signal is input from the load switch unit 700 (the electrical signal is greater than 0), and the estimated load based on the motor current estimation remains 0, the control unit 800 determines that the motor current monitoring function is faulty. Furthermore, the control unit 800 outputs a fault message for the motor current monitoring function via the output unit 1100.

[0115] In this situation, the output unit 110 can provide visual or audible warnings of a malfunction in the motor current monitoring function.

[0116] In the following text, reference will be made to Figure 12 A method for calibrating the braking force of a vehicle braking device to zero according to embodiments of the present disclosure is described in detail.

[0117] Figure 12 This is a flowchart of a method for calibrating the braking force of a vehicle braking device to zero according to an embodiment of the present disclosure.

[0118] Reference Figure 12 The control unit 800 operates the motor 910 (S100).

[0119] As the motor unit 900 operates, the motor current measurement unit 1000 measures the motor current of the motor 910 and inputs the measurement result to the control unit 800.

[0120] The control unit 800 estimates the load based on the motor current input from the motor current measurement unit 1000 (S300).

[0121] Furthermore, when the motor unit 900 is operated, the screw lever 300 rotates with the power from the motor unit 900, causing the nut unit 400 to move linearly.

[0122] That is, in order to brake the vehicle, the lever 300 rotates in a predetermined direction with the power from the motor unit 900, the nut unit 400 and the piston unit 500 move toward the brake pad 200, and the piston unit 500 presses the brake pad 200.

[0123] When the brake pad 200 contacts the brake disc 10, braking force is generated. When the piston unit 500 presses down on the brake pad 200, a repulsive force is applied to the piston unit 500 and the nut unit 400, and the repulsive force is also applied to the lever 300.

[0124] The bearing unit 600 moves backward by means of the repulsive force of the lever 300, and the bearing unit 600 presses the load switch unit 700, causing the load switch unit 700 to operate and input an electrical signal to the control unit 800.

[0125] Therefore, the control unit 800 checks whether an electrical signal is input from the load switch unit 700 (S400). When an electrical signal is input, the control unit 800 checks whether the estimated load as described above is 0 (S500).

[0126] When the check result in step S500 indicates that the estimated load is 0, the control unit 800 determines whether the estimated load will remain at 0 for a predetermined time or longer (S600).

[0127] When the determination result in step S600 indicates that the estimated load remains at 0, the control unit 800 determines that the motor current monitoring function is faulty and outputs the determination result via the output unit 110 (S700).

[0128] When the determination result in step S610 indicates that the estimated load is not maintained at 0 and the estimated load changes, the control unit 800 determines that the estimated load is normal.

[0129] Conversely, when the check result in step S500 indicates that the estimated load is not 0, the control unit 800 calibrates the estimated load based on the motor current estimate to 0 at the time point when the electrical signal is input from the load switch unit 700 (S800).

[0130] Additionally, the control unit 800 can calibrate all estimated loads for each motor current by calibrating a lookup table or calculation formula used to estimate the load based on the motor current (S900).

[0131] As described above, the apparatus and method for calibrating the braking force of a vehicle braking device to zero according to embodiments of the present disclosure reduce initial inefficiency and improve the accuracy of calculating the output load by calibrating the estimated time point of load generation by the motor current at the time point when the load is actually generated on the brake pads of the vehicle braking device.

[0132] For example, the configuration described in this specification can be implemented as a method or process, apparatus, software program, data stream, or signal. Although a single form of implementation is described (e.g., only a method is described), the described features can also be in other forms (e.g., apparatus or program). The apparatus can be implemented as suitable hardware, software, firmware, etc. For example, the method can be implemented by an apparatus, such as a processor, which generally refers to a processing apparatus including computers, microprocessors, integrated circuits, programmable logic devices, etc. Processors also include communication devices, such as computers, mobile phones, portable / personal information terminals (personal digital assistants (PDAs)), and other devices that facilitate information exchange with end users.

[0133] Although this disclosure has been described with reference to embodiments shown in the figures, the description of the embodiments is for illustrative purposes only, and those skilled in the art will understand that various variations of the embodiments, as well as any other equivalent embodiments, are available.

Claims

1. A vehicle braking device, the vehicle braking device comprising: Caliper body, configured to surround the brake disc; A pair of brake pads are arranged facing each other in the caliper body and positioned on opposite sides of the brake disc. A lever, which is mounted in the caliper body and configured to rotate by means of power from the motor unit; A nut unit configured to move linearly by means of the screw lever; A piston unit configured to surround the outside of the nut unit and to press either of the pair of brake pads by moving together with the nut unit; A bearing unit configured to support the rotation of the wire lever and move by means of the repulsive force of the wire lever; A load switch unit is mounted in the caliper body, arranged to face the bearing unit, and configured to be operated by being pressed by the bearing unit; as well as A control unit configured to receive electrical signals from the load switching unit and control the operation of the motor unit based on the electrical signals. The load switching unit includes: The housing portion installed in the caliper body; A movable block portion mounted in the housing portion, configured to be moved by being pressed by the bearing unit, the movable block portion being configured to return to its original position by means of an elastic restoring force when the bearing unit is released; and The connector portion is configured to transmit the electrical signal to the control unit by contacting the movable block portion when the movable block portion moves.

2. The vehicle braking device according to claim 1, wherein, The movable block portion protrudes to the outside of the housing portion.

3. The vehicle braking device according to claim 2, wherein, The movable block portion includes: A movable block, movably arranged within the housing portion and configured to contact the connector portion; and An elastic member is connected to the movable block, coupled to the connector portion, and configured to elastically support the movable block.

4. The vehicle braking device according to claim 3, wherein, The connector portion includes: Connector body, which is connected to the elastic member; and The contact portion is installed in the connector body and configured to generate the electrical signal by contacting the movable block.

5. The vehicle braking device according to claim 4, wherein, The movable block includes: The movable block body is elastically supported by the elastic member; and A conductor plate, which is mounted in the movable block body and configured to contact the contact portion.

6. The vehicle braking device according to claim 5, wherein, The contact portion includes: Contact protrusions, which are mounted in the connector body and configured to contact the conductor plate; and A terminal, which is connected to the contact protrusion and configured to transmit the electrical signal to the control unit, generates the electrical signal between the contact protrusion and the conductor plate when the conductor plate contacts the contact protrusion.

7. An apparatus for calibrating the braking force of a vehicle braking device according to claim 1 to zero, the apparatus comprising: A load switch unit configured to output an electrical signal when the brake pads actually press against the brake disc and the lever moves backward by means of repulsive force; A motor current measuring unit is configured to measure the motor current of a motor that causes the lead lever to rotate, thereby causing the brake pads to press against the brake disc. as well as A control unit configured to, during operation of the motor, estimate the load applied to the wire lever based on the motor current, and calibrate the estimated load to zero based on the electrical signal.

8. The apparatus for calibrating the braking force of a vehicle braking device to zero according to claim 7, wherein, The control unit calibrates the estimated load to zero based on the estimated load estimated at the time point when the electrical signal is input.

9. The apparatus for calibrating the braking force of a vehicle braking device to zero according to claim 8, wherein, When the estimated load is not 0 at the time point when the electrical signal is input, the control unit will calibrate the estimated load to 0 at the time point when the electrical signal is input.

10. The apparatus for calibrating the braking force of a vehicle braking device to zero according to claim 7, wherein, The control unit calibrates all estimated loads for each motor current based on a zero point calibrated at the time the electrical signal is input.

11. The apparatus for calibrating the braking force of a vehicle braking device to zero according to claim 7, wherein, When the estimated load remains at 0 for a predetermined time or longer after the input of the electrical signal, the control unit determines that the motor current monitoring function of the motor current measurement unit has malfunctioned.

12. A method for calibrating the braking force of a vehicle braking device according to claim 1 to zero, the method comprising the following steps: When the motor rotates the lead lever, causing the brake pads to press against the brake disc, the motor current measurement unit measures the motor current of the motor, and the control unit detects the estimated load applied to the lead lever based on the motor current measured by the motor current measurement unit. When the brake pad actually presses against the brake disc and the lever moves backward by means of repulsive force, the load switch unit outputs an electrical signal; as well as When the electrical signal is input from the load switching unit, the control unit performs zero-point calibration on the estimated load based on the time point of the input electrical signal.

13. The method for calibrating the braking force of a vehicle braking device to zero according to claim 12, wherein, The step of zero-point calibration of the estimated load includes zero-point calibration of the estimated load based on the estimated load estimated at the time point at which the electrical signal is input.

14. The method for calibrating the braking force of a vehicle braking device to zero according to claim 13, wherein, The step of zero-point calibration of the estimated load includes calibrating the estimated load at the time point when the input electrical signal is not 0 to 0.

15. The method for calibrating the braking force of a vehicle braking device to zero according to claim 12, wherein, In the step of performing zero-point calibration on the estimated load, the control unit performs zero-point calibration for all estimated loads of each motor current based on the calibration performed at the time point at which the electrical signal is input.

16. The method for calibrating the braking force of a vehicle braking device to zero according to claim 12, the method further comprising the following steps: When the estimated load remains at 0 for a predetermined time or longer after the input of the electrical signal, the control unit determines that the motor current monitoring function of the motor current measurement unit has malfunctioned.

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